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This application is a continuation-in-part of U.S. Ser. No. 664,146 filed Mar. 4, 1991 U.S. Pat. No. 5,171,833 which is a continuation-in-part of U.S. application Ser. No. 07/352,782 filed on May 16, 1989, now U.S. Pat. No. 5,068,313.
BACKGROUND OF THE INVENTION
Various forms of hydrogenated nitrile rubbers have recently been introduced into the marketplace. Hydrogenated nitrile rubber has the advantage of being resistant to oxidative degradation at high temperature, as well as being resistant to corrosive environments such as acid environments. These materials have found utility in the manufacture of fan belts, seals, gaskets, and hoses in increasingly small and hot-running car engines.
One process for the production of hydrogenated latex polymers, particularly hydrogenated latex rubber, utilizes hydrazine and an unsaturated polymer as the starting materials. This process is more particularly described in U.S. Pat. No. 4,452,950, assigned to the Goodyear Tire and Rubber Company. However, the product produced in accordance with the process described in the '950 patent suffers from the disadvantage of containing residual unreacted hydrazine. This residual hydrazine is considered undesirable from an environmental and/or toxicity standpoint.
In view of the above, it would be highly desirable to provide a process for the elimination and/or reduction of the residual hydrazine in the hydrogenated polymer product mixture.
SUMMARY OF THE INVENTION
In one aspect, the present invention relates to a process for the hydrogenation of a polymer latex and the reduction or elimination of residual free hydrazine from the polymer latex characterized by:
(a) contacting said polymer latex with hydrazine and peroxide at a temperature of between about 60° C. and about 70° C., in the presence of a metal ion initiator selected from the group consisting of copper sulfate, ferrous sulfate, and combinations thereof, in order to effect a reaction of said polymer latex with said hydrazine and said peroxide, using a reaction time of between about 1 hour and about 5 hours, thereby producing a hydrogenated polymer latex, and
(b) contacting free hydrazine in said polymer latex with a hydrazine scavenger selected from the group consisting of isocyanates, alkylene oxides, acrylates, methacrylates, acrylic acids, acrylonitrile, methacrylic acids, ketones, diketones, aldehydes, and combinations thereof, in a scavenging effective amount of between 1 and 10 times the number of moles of hydrazine present in said purified mixture in order to bind at least a portion of said free hydrazine, thereby providing a hydrogenated polymer latex containing a reduced amount of free hydrazine therein.
These and other aspects of the present invention will become apparent upon a reading of the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The polymer/hydrazine mixture generally contains a major amount (i.e. typically greater than 70 weight percent) of water, saturated polymer (typically about 5 to about 25 weight percent), a minor amount of unsaturated polymer (typically between about one and five weight percent), and a minor amount (typically between about 0.1 and about 3 weight percent) of hydrazine, wherein the weight percents are based upon the total weight of the latex. For most applications, it is preferred that the amount of hydrazine be minimized in the mixture. Reduction or elimination of the hydrazine in the mixture provides a mixture having reduced toxicity.
The hydrazine scavenger useful in the processes of the present invention acts to bind at least some portion of the free hydrazine in the purified latex. Useful hydrazine scavengers are compounds that react with hydrazine and include the following classes of compounds: isocyanates (such as tolylene diisocyanate, phenyl isocyanate and methylene dipenyl isocyanate (MCI)); alkylene oxides (such as ethylene oxide, propylene oxide, isobutylene oxide, styrene oxide, and polymeric epoxides); acrylates and methacrylates (such as methyl methacrylate); acrylonitrile, acrylic acids and methacrylic acids; ketones and diketones (such as acetyl acetone); aldehydes (such as benzaldehyde); and combinations thereof.
The hydrazine scavenger is employed in a "scavenging effective amount". As used herein, the term "scavenging effective amount" designates an amount of hydrazine scavenger sufficient to react with and bind at least some amount of the free hydrazine in the latex mixture. Preferably, the hydrazine scavenger is employed in an amount of between about 1 and about 10, more preferably between about 1 and about 5 times the theoretical molar amount required to react with the free hydrazine present in the hydrazine/latex mixture.
In a preferred embodiment of the two-step process of the present invention, step (a) of the two-step process is utilized to hydrogenate the polymer latex with hydrazine and peroxide, and then step (b) is employed to reduce the amount of free hydrazine in the mixture to 25 ppm or less.
The polymer/hydrazine mixture in latex form is prepared by hydrogenation of unsaturated polymers. Prior to hydrogenation, the unsaturated polymers are typically composed of 5 to 100 percent by weight of a conjugated diene monomer unit and 95 to 0 percent by weight of an ethylenically-unsaturated monomer unit. Specific examples of the conjugated diene monomer are 1,3-butadiene, 2,3-dimethylbutadiene, isoprene, and 1,3-pentadiene, specific examples of the ethylenically unsaturated monomer include unsaturated nitriles such as acrylonitrile and methacrylonitrile, monovinyl aromatic hydrocarbons such as styrene, (o-, m-, and p-) alkylstyrenes, divinyl aromatic such as divinylbenzene, dialkenyl aromatics such as diisopropenylbenzene, unsaturated carboxylic acids and the esters thereof such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, maleic acid, methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate and methyl methacrylate; vinyl pyridine; and vinyl esters such as vinyl acetate.
The conjugated diene polymer may be one prepared by any method of preparation, such as emulsion polymerization, solution polymerization or bulk polymerization. Specific examples of the conjugated diene polymer include polyisoprene, polybutadiene, a styrene/butadiene (random or block) copolymer, an acrylonitrile/butadiene (random or blocked) copolymer, a butadiene/isoprene copolymer, and an isoprene/isobutylene copolymer.
Suitable peroxides include organic peroxides, inorganic peroxides, and combinations thereof, such as, for example, hydrogen peroxide, alkali metal peroxides such as sodium peroxide and potassium peroxide, peracetic acid, benzoyl peroxide, alkali metal persulfates, and the like. Preferred peroxides are hydrogen peroxide and sodium peroxide, most preferably hydrogen peroxide. The peroxide is preferably employed in the presence of a metal ion initiator, such as copper sulfate or ferrous sulfate. The reaction time for the process of the present invention can vary over a wide range, but is preferably between about 1 hour and about 50 hours, more preferably between about 1 hour and about 25 hours, most preferably between about 1 hour and about 20 hours.
The following examples are intended to illustrate, but in no way limit the scope of, the present invention.
EXAMPLE 1
Part A--Hydrogenations of a Latex
Run (1)--Hydrogenation at 45° C. to 50° C.
An acrylonitrile/butadiene rubber with 66.2 weight percent butadiene and an average molecular weight of about 200,000 was hydrogenated in latex form with a mixture of hydrazine and hydrogen peroxide in a manner approximately as described in U.S. Pat. No. 4,452,950, without a metal ion initiator at a temperature of 45° C. to 50° C. After achieving about 88 percent conversion of the C═C double bonds, the run was interrupted. At this point in the reaction, the latex contained 4.05 weight percent unreacted hydrazine, based on the weight of the aqueous phase of the latex.
Run (2)--Hydrogenation at 60° C.
80 g (0.314 mole double bond) of an acrylonitrile/butadiene lates, with 61.1 weight percent butadiene, (34.8% rubber) charged to flask. Antifoam and CuSO 4 catalyst added followed by 21.3 mls 64.3% N 2 H 4 (0.441 mole) with an exotherm to 30° C. The reaction was heated to 60° C. and 36 mls of 49.4% H 2 O 2 were added over 4.2 hours. The reaction was post reacted 1 hour, then allowed to cool to room temperature over 2 hours. The final latex was 96.7% hydrogenated with no residual H 2 O 2 and 125 ppm residual N 2 H 4 based on the weight of the aqueous phase of the latex.
Run (3)--Hydrogenation at 70° C.
75 g (0.162 mole double bond) of an acrylonitrile/butadiene latex, with 63 weight percent butadiene, (18.5% rubber) charged to flask. Antifoam and 19.3 mls 64.2% N 2 H 4 (0.4 mole) charged to flask with an exotherm to 27° C. The reaction was heated to 70° C., and 39.8 mls 30.8% H 2 O 2 (0.4 mole) added over 4.5 hours. The reaction was post reacted 3 hours at 70° C., then cooled and left stirring overnight. No unsaturation was detected in the final latex by NMR. 1.11% residual N 2 H 4 and no residual H 2 O 2 were found based on the weight of the aqueous phase of the latex.
Part B--Binding of Free Hydrazine in Product of Run (1)
To a portion of this hydrogenated latex was added an excess of methyl acrylate and stirred at room temperature for 1.5 hours. During this period, there was a noticeable exotherm. The final hydrazine content was about 470 ppm, based on the weight of the aqueous phase of the latex, which represents about a 99 percent removal of hydrazine from the latex.
Another Illustration of Binding of Free Hydrazine
To a portion of a latex hydrogenated in a manner analogous to Run 2 above, but containing 58 ppm of residual free hydrazine, was added a molar excess of 2,4-pentanedione relative to the amount of free hydrazine present in the latex. The mixture was stirred at 45° C. for 2.5 hours. The hydrazine level was reduced from 58 ppm to less than 0.5 ppm. This represents more than a 99% removal of the free hydrazine from the latex. | This invention relates to a process for minimizing or reducing the amount of residual free hydrazine in polymer latices. The process is particularly useful in the manufacture of hydrogenated nitrile rubber which is resistant to oxidative degradation at high temperatures, as well as resistant to corrosive environments such as acid environments. Nitrile rubbers are useful in the manufacture of fan belts, seals, gaskets, and hoses in increasingly small and hot-running car engines. | 2 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of U.S. Provisional Application No. 61/243,892, filed Sep. 18, 2009, which is hereby incorporated by reference.
TECHNICAL FIELD
[0002] The invention relates to compounds useful in treating conditions associated with calcium channel function, and particularly conditions associated with T-type calcium channel activity. More specifically, the invention concerns compounds containing substituted amino N-piperidinyl acetamide derivatives that are useful in the prophylactic care, amelioration, or diagnosis of conditions associated with ion channel function, such as the treatment or prevention of conditions such as cardiovascular disease, obesity, epilepsy and pain.
BACKGROUND OF THE INVENTION
[0003] Calcium channels mediate a variety of normal physiological functions and are also implicated in a number of human disorders. Examples of calcium-mediated human disorders include but are not limited to congenital migraine, cerebellar ataxia, angina, epilepsy, hypertension, ischemia, and some arrhythmias (see, e.g., Janis et al., Ion Calcium Channels: Their Properties, Functions, Regulation and Clinical Relevance (1991) CRC Press, London). T-type, or low voltage-activated, channels describe a broad class of molecules that transiently activate at negative potentials and are highly sensitive to changes in resting potential and are involved in various medical conditions. For example, in mice lacking the gene expressing the 3.1 subunit (Ca V 3.1), resistance to absence seizures was observed (Kim et al., Mol Cell Neurosci 18(2): 235-245, 2001). Other studies have also implicated the 3.2 subunit (Ca V 3.2) in the development of epilepsy (Su et al., J Neurosci 22: 3645-3655, 2002).
[0004] Novel allosteric modulators of calcium channels, e.g., T-type calcium channels, are thus desired. Modulators may affect the kinetics and/or the voltage potentials of, e.g., the Ca V 3.2 channel.
[0005] The invention provides compounds that act at these T-type calcium channels and are useful to treat various conditions associated with these calcium channels, such as pain and epilepsy. It also provides pharmaceutical compositions containing these compounds and methods to use them either alone or in combination with other pharmaceutical agents.
SUMMARY OF THE INVENTION
[0006] In a first aspect, the invention features a compound according to the following formula,
[0000]
[0000] or a pharmaceutically acceptable salt, solvate, or prodrug thereof, or a stereoisomer thereof, or a conjugate thereof, where
[0007] Ar is phenyl or a 5-6 membered heteroaryl ring containing at least one heteroatom selected from N, O and S as a ring member, and optionally substituted with at least one R 8 , R 9 , or R 10 ;
[0008] T is CH 2 , O, or NR 1 ;
[0009] A is [T]-C(O)—NR 1 or [T]-NR 1 —C(O)— or [T]-C(O)—O—, or [T]-O—C(O)—, —NR 1 —C(O)—NR 1 —; [T]-O—C(O)—NR 1 —; or [T]-NR 1 —C(O)—O—; where [T] indicates which atom of A is linked to T in Formula (I);
[0010] R 1 and R 2 are independently selected from the group consisting of H, optionally substituted C1-C6 alkyl, C1-C6 optionally substituted alkylsulfonyl, and optionally substituted C1-C6 acyl;
[0011] R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from H, optionally substituted C1-C6 alkyl, halo, hydroxy, CN, optionally substituted C1-C6 alkoxy, and optionally substituted C1-C6 heteroalkyl;
[0012] where R 2 and R 3 , or R 3 and R 4 , or R 4 and R 5 , or R 6 and R 2 , or two R 6 if two R 6 are present (any one of these pairs, but not more than one pair) can optionally be taken together to form a non-aromatic 5-6 membered ring, which can optionally include up to two heteroatoms selected from N, O and S as ring members;
[0013] and two R 7 can optionally be taken together to form a non-aromatic 5-6 membered ring, which can optionally include a heteroatom selected from N, O and S as a ring member;
[0014] m and n are independently 1 or 2;
[0015] p is 0-2;
[0016] q is 0, 1 or 2;
[0017] R 8 , R 9 , and R 10 are optional substituents that are independently selected from the group consisting of H, halogen, CN, —SO 2 —(C1-C4 alkyl), optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, optionally substituted aryl, and optionally substituted heteroaryl, provided at least one of R 8 , R 9 , and R 10 is present and is not H.
[0018] In some embodiments, the compound ha a structure according to the following formula,
[0000]
[0000] where
[0019] q is 0 or 1;
[0020] A is an amide of the formula —NR 1 —C(O)— or —C(O)—NR 1 —; or a urea of the formula —NR 1 —C(O)—NR 1 —; or a carbamate of the formula —O—C(O)—NR 1 — or —NR 1 —C(O)—O—;
[0021] Ar is a phenyl or pyridyl group that is substituted by R 8 , R 9 , and R 10 , or Ar is a 1,3,4-oxadiazolyl group optionally substituted by R 8 ; and
[0022] R 8 , R 9 , and R 10 are, independently, selected from the group consisting of H, F, Cl, Br, CN, optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, and —SO 2 -(optionally substituted C1-C4 alkyl).
[0023] In further embodiments, the compound has a structure according to the following formula,
[0000]
[0024] In other embodiments, R 8 , R 9 , and R 10 are, independently, selected from F, Cl, Br, Me, OMe, SO 2 CF 3 , —OCF 3 , —OCHF 2 , C2-C4 alkyl, C2-C4 alkoxy, —CHF 2 , —CH 2 F, and —CF 3 .
[0025] In other embodiments, R 8 , R 9 , and R 10 are, independently, selected from F, Cl, Br, Me, OMe, and CF 3 .
[0026] In further embodiments, m is 2 and n is either 1 or 2.
[0027] In certain embodiments, p is 0.
[0028] In other embodiments, n is 2.
[0029] In still other embodiments, R 4 and R 5 taken together form a non-aromatic 5-6 membered ring, which can optionally include a heteroatom selected from N, O and S as a ring member.
[0030] In certain embodiments, R 4 and R 5 taken together form a cyclohexane or cyclopentane ring.
[0031] In some embodiments, the compound has a structure according to the following formula,
[0000]
[0000] where
m is 1 or 2; -T-A- is —CH 2 CONH—, —CH 2 NHCO—, —CH 2 NHCONH—, —CH 2 OCONH—, —NHCONH—, or —OCONH—; R 2 is H or optionally substituted C1-C6 alkyl; R 7 is H, OH, or optionally substituted C1-C6 alkyl; R 8 is halogen or optionally substituted C1-C6 alkyl; and R 9 and R 10 are, independently, selected from H, halogen, and optionally substituted C1-C6 alkyl.
[0032] In certain embodiments, T-A- is —CH 2 CONH—.
[0033] In other embodiments, -T-A- is —CH 2 NHCONH— or —NHCONH—.
[0034] In some embodiments, the compound has a structure according to Formula (III) and m is 1.
[0035] In other embodiments, the compound has a structure according to Formula (III) and m is 2.
[0036] In certain embodiments, R 8 is F, Cl, Br, or CF 3 .
[0037] In other embodiments, R 9 is H, F, Cl, Br, or CF 3 .
[0038] In still other embodiments, R 8 and R 9 are both CF 3 , or R 8 and R 9 are both F.
[0039] In certain embodiments, R 7 is H.
[0040] In some embodiments, the compound has a structure according to the following formula,
[0000]
[0000] where
m is 1 or 2; -T-A- is —CH 2 CONH—, —CH 2 NHCO—, —CH 2 NHCONH—, —CH 2 OCONH—, —NHCONH—, or —OCONH—; R 2 is H or optionally substituted C1-C6 alkyl; R 7 is H, OH, or optionally substituted C1-C6 alkyl; R 8 is halogen, optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, or SO 2 (optionally substituted C1-C6 alkyl); and R 9 and R 10 are, independently, selected from H, halogen, and optionally substituted C1-C6 alkyl.
[0041] In other embodiments, -T-A- is —CH 2 CONH—.
[0042] In still other embodiments, -T-A- is —CH 2 NHCONH— or —NHCONH—.
[0043] In certain embodiments, the compound has a structure according to Formula (V) and m is 1.
[0044] In other embodiments, the compound has a structure according to Formula (V) and m is 2.
[0045] In some embodiments, R 8 is F, Br, CF 3 , OCF 3 , SO 2 CF 3 , or SO 2 CH 3 .
[0046] In other embodiments, R 9 is H, F, Cl, Br, or CF 3 .
[0047] In still other embodiments, R 7 is H.
[0048] In further embodiments, R 10 is H.
[0049] In some embodiments, R 2 is H.
[0050] In certain embodiments, the compound has a structure according to
[0000]
[0000] where m is 1 or 2; -T-A- is —CH 2 CONH—, —CH 2 NHCO—, —CH 2 NHCONH—, —CH 2 OCONH—, —NHCONH—, or —OCONH—; R 2 is H or optionally substituted C1-C6 alkyl; R 7 is H, OH, or optionally substituted C1-C6 alkyl;
Ar is
[0051]
[0000] and R 8 is halogen, optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, or SO 2 (optionally substituted C1-C6 alkyl).
[0052] In some embodiments, -T-A- is —CH 2 CONH—.
[0053] In other embodiments, R 8 is CF 3 .
[0054] In certain embodiments, the carbon marked with * has the R configuration. In other embodiments, the carbon marked with * has the S configuration. In further embodiments, the carbon marked with ** has the R configuration. In other embodiments, the carbon marked with ** has the S configuration.
[0055] In still other embodiments, the compound has a structure according to the following formula,
[0000]
[0000] where X is CH 2 or O; m is 1 or 2; -T-A- is —CH 2 CONH—, —CH 2 NHCO—, —CH 2 NHCONH—, —CH 2 OCONH—, —NHCONH—, or —OCONH—; R 1 is H or optionally substituted C1-C6 alkyl; R 2 is H or optionally substituted C1-C6 alkyl; R 7 is H, OH, or optionally substituted C1-C6 alkyl; R 8 is halogen, optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, or SO 2 (optionally substituted C1-C6 alkyl); and R 9 and R 10 are, independently, selected from H, halogen, and optionally substituted C1-C6 alkyl.
[0056] In some embodiments, X is CH 2 .
[0057] In other embodiments, R 1 is H or unsubstituted C1-C6 alkyl.
[0058] In still other embodiments, X is O.
[0059] In certain embodiments, R 1 is H.
[0060] In some embodiments, m is 2.
[0061] In other embodiments, R 8 and R 9 are both CF 3 .
[0062] In other embodiments, the compound has a structure according to the following formula,
[0000]
[0000] where each of R 1 -R 6 is selected, independently, from H or unsubstituted C1-C6 alkyl; n is 1 or 2; m is 1 or 2; -T-A- is —CH 2 CONH—, —CH 2 NHCO—, —CH 2 NHCONH—, —CH 2 OCONH—, —NHCONH—, or —OCONH—; R 7 is H, OH, or optionally substituted C1-C6 alkyl; R 8 is halogen, optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, or SO 2 (optionally substituted C1-C6 alkyl); and R 9 and R 10 are, independently, selected from H, halogen, and optionally substituted C1-C6 alkyl.
[0063] In some embodiments, R 1 and R 2 are both H.
[0064] In other embodiments, R 3 and R 4 are both CH 3 .
[0065] In certain embodiments, R 5 and R 6 are both CH 3 .
[0066] In still other embodiments, n and m are both 1.
[0067] In certain embodiments, n and m are both 2.
[0068] In other embodiments, one of n and m is 1, and the other is 2.
[0069] In further embodiments, R 8 and R 9 are both CF 3 .
[0070] In certain embodiments, the compound has a structure according to the following formula,
[0000]
[0000] where each of R 1 , R 2 , R 5 , R 6 , and R 7 is selected, independently, from H or unsubstituted C1-C6 alkyl; n is 1 or 2; m is 1 or 2; -T-A- is —CH 2 CONH—, —CH 2 NHCO—, —CH 2 NHCONH—, —CH 2 OCONH—, —NHCONH—, or —OCONH—; R 8 is halogen, optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, or SO 2 (optionally substituted C1-C6 alkyl); and R 9 and R 10 are, independently, selected from H, halogen, and optionally substituted C1-C6 alkyl.
[0071] In some embodiments, q is 0. In other embodiments, q is 1.
[0072] In certain embodiments, R 5 and R 6 are both H.
[0073] In other embodiments, R 1 and R 2 are both H.
[0074] In still other embodiments, R 8 and R 9 are both CF 3 .
[0075] In other embodiments, the compound has a structure according to the following formula,
[0000]
[0000] where each of R 1 , R 4 , R 5 , R 6 , and R 7 is selected, independently, from H or unsubstituted C1-C6 alkyl; n is 1 or 2; m is 1 or 2; -T-A- is —CH 2 CONH—, —CH 2 NHCO—, —CH 2 NHCONH—, —CH 2 OCONH—, —NHCONH—, or —OCONH—; R 8 is halogen, optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, or SO 2 (optionally substituted C1-C6 alkyl); and R 9 and R 10 are, independently, selected from H, halogen, and optionally substituted C1-C6 alkyl.
[0076] In some embodiments, q is 0. In other embodiments, q is 1.
[0077] In certain embodiments, R 1 and R 4 are, independently H or CH 3 .
[0078] In other embodiments, one of n and m is 1, and the other is 2.
[0079] In further embodiments, R 8 and R 9 are both CF 3 .
[0080] In some embodiments, the compound is selected from the group consisting of the following structures:
[0000]
No.
Structure
1
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[0081] In further embodiments, the compound is selected from the following group of structures:
[0000]
No.
Structure
1
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[0082] In some embodiments, the compound is
[0000]
[0083] In another aspect, the invention features a pharmaceutical composition that includes any of the compounds described herein, or a pharmaceutically acceptable salt, solvate, or prodrug thereof, or a stereoisomer thereof, or a conjugate thereof, and a pharmaceutically acceptable carrier or excipient.
[0084] In some embodiments, the pharmaceutical composition is formulated in unit dosage form.
[0085] In further embodiments, the unit dosage form is a tablet, caplet, capsule, lozenge, film, strip, gelcap, or syrup.
[0086] In still another aspect, the invention features a method to treat a condition modulated by calcium channel activity, where the method includes administering to a subject in need of such treatment an effective amount of any of the compounds described herein, or a pharmaceutically acceptable salt, solvate, or prodrug thereof, or a stereoisomer thereof, or a conjugate thereof, or a pharmaceutical composition thereof.
[0087] In some embodiments, the calcium channel is a T-type calcium channel. In other embodiments, the calcium channel is the Ca V 3.1, Ca V 3.2, or Ca V 3.3 channel.
[0088] In certain embodiments, the condition is pain, epilepsy, Parkinson's disease, depression, psychosis (e.g., schizophrenia), or tinnitus.
[0089] In some embodiments, the condition is pain or epilepsy.
[0090] In certain embodiments, the pain is inflammatory pain or neuropathic pain. In other embodiments, the pain is chronic pain (e.g., peripheral neuropathic pain, central neuropathic pain, musculoskeletal pain, headache, visceral pain, or mixed pain). In further embodiments, the peripheral neuropathic pain is post-herpetic neuralgia, diabetic neuropathic pain, neuropathic cancer pain, failed back-surgery syndrome, trigeminal neuralgia, or phantom limb pain; the central neuropathic pain is multiple sclerosis related pain, Parkinson disease related pain, post-stroke pain, post-traumatic spinal cord injury pain, or pain in dementia; the musculoskeletal pain is osteoarthritic pain and fibromyalgia syndrome; inflammatory pain such as rheumatoid arthritis, or endometriosis; the headache is migraine, cluster headache, tension headache syndrome, facial pain, or headache caused by other diseases; the visceral pain is interstitial cystitis, irritable bowel syndrome, or chronic pelvic pain syndrome; or the mixed pain is lower back pain, neck and shoulder pain, burning mouth syndrome, or complex regional pain syndrome.
[0091] In some embodiments, the headache is migraine.
[0092] In other embodiments, the pain is acute pain (e.g., nociceptive pain or post-operative pain). In certain embodiments, the acute pain is post-operative pain.
[0093] As used herein, the term “alkyl,” “alkenyl” and “alkynyl” include straight-chain, branched-chain and cyclic monovalent substituents, as well as combinations of these, containing only C and H when unsubstituted. Examples include methyl, ethyl, isobutyl, cyclohexyl, cyclopentylethyl, 2-propenyl, 3-butynyl, and the like. Typically, the alkyl, alkenyl and alkynyl groups contain 1-10C (alkyl) or 2-10C (alkenyl or alkynyl). In some embodiments, they contain 1-8C, 1-6C, 1-4C, 1-3C or 1-2C (alkyl); or 2-8C, 2-6C, 2-4C or 2-3C (alkenyl or alkynyl). Further, any hydrogen atom on one of these groups can be replaced with a halogen atom, and in particular a fluoro or chloro, and still be within the scope of the definition of alkyl, alkenyl and alkynyl. For example, CF 3 is a 1C alkyl. These groups may be also be substituted by other substituents as described herein.
[0094] Heteroalkyl, heteroalkenyl and heteroalkynyl are similarly defined and contain at least one carbon atom but also contain one or more O, S or N heteroatoms or combinations thereof within the backbone residue whereby each heteroatom in the heteroalkyl, heteroalkenyl or heteroalkynyl group replaces one carbon atom of the alkyl, alkenyl or alkynyl group to which the heteroform corresponds. In some embodiments, the heteroalkyl, heteroalkenyl and heteroalkynyl groups have C at each terminus to which the group is attached to other groups, and the heteroatom(s) present are not located at a terminal position. As is understood in the art, these heteroforms do not contain more than three contiguous heteroatoms. In some embodiments, the heteroatom is O or N.
[0095] The designated number of carbons in heteroforms of alkyl, alkenyl and alkynyl includes the heteroatom count. For example, if heteroalkyl is defined as 1-6C, it will contain 1-6 C, N, O, or S atoms such that the heteroalkyl contains at least one C atom and at least one heteroatom, for example 1-5C and 1N or 1-4C and 2N. Similarly, when heteroalkyl is defined as 1-6C or 1-4C, it would contain 1-5C or 1-3C respectively, i.e., at least one C is replaced by O, N or S. Accordingly, when heteroalkenyl or heteroalkynyl is defined as 2-6C (or 2-4C), it would contain 2-6 or 2-4 C, N, O, or S atoms, since the heteroalkenyl or heteroalkynyl contains at least one carbon atom and at least one heteroatom, e.g. 2-5C and 1N or 2-4C and 2O. Further, heteroalkyl, heteroalkenyl or heteroalkynyl substituents may also contain one or more carbonyl groups. Examples of heteroalkyl, heteroalkenyl and heteroalkynyl groups include CH 2 OCH 3 , CH 2 N(CH 3 ) 2 , CH 2 OH, (CH 2 ) n NR 2 , OR, COOR, CONR 2 , (CH 2 ) n OR, (CH 2 ) n COR, (CH 2 ) n COOR, (CH 2 ) n SR, (CH 2 ) n SOR, (CH 2 ) n SO 2 R, (CH 2 ) n CONR 2 , NRCOR, NRCOOR, OCONR 2 , OCOR and the like wherein the R group contains at least one C and the size of the substituent is consistent with the definition of e.g., alkyl, alkenyl, and alkynyl, as described herein.
[0096] As used herein, the terms “alkylene,” “alkenylene” and “alkynylene” refers to divalent or trivalent groups having a specified size, typically 1-2C, 1-3C, 1-4C, 1-6C or 1-8C for the saturated groups and 2-3C, 2-4C, 2-6C or 2-8C for the unsaturated groups. They include straight-chain, branched-chain and cyclic forms as well as combinations of these, containing only C and H when unsubstituted. Because they are divalent, they can link together two parts of a molecule, as exemplified by X in the compounds described herein. Examples are methylene, ethylene, propylene, cyclopropan-1,1-diyl, ethylidene, 2-butene-1,4-diyl, and the like. These groups can be substituted by the groups typically suitable as substituents for alkyl, alkenyl and alkynyl groups as set forth herein. Thus C═O is a C1 alkylene that is substituted by ═O, for example.
[0097] Heteroalkylene, heteroalkenylene and heteroalkynylene are similarly defined as divalent groups having a specified size, typically 1-3C, 1-4C, 1-6C or 1-8C for the saturated groups and 2-3C, 2-4C, 2-6C or 2-8C for the unsaturated groups. They include straight chain, branched chain and cyclic groups as well as combinations of these, and they further contain at least one carbon atom but also contain one or more O, S or N heteroatoms or combinations thereof within the backbone residue, whereby each heteroatom in the heteroalkylene, heteroalkenylene or heteroalkynylene group replaces one carbon atom of the alkylene, alkenylene or alkynylene group to which the heteroform corresponds. As is understood in the art, these heteroforms do not contain more than three contiguous heteroatoms.
[0098] “Aromatic” moiety or “aryl” moiety refers to any monocyclic or fused ring bicyclic system which has the characteristics of aromaticity in terms of electron distribution throughout the ring system and includes a monocyclic or fused bicyclic moiety such as phenyl or naphthyl; “heteroaromatic” or “heteroaryl” also refers to such monocyclic or fused bicyclic ring systems containing one or more heteroatoms selected from O, S and N. The inclusion of a heteroatom permits inclusion of 5-membered rings to be considered aromatic as well as 6-membered rings. Thus, typical aromatic/heteroaromatic systems include pyridyl, pyrimidyl, indolyl, benzimidazolyl, benzotriazolyl, isoquinolyl, quinolyl, benzothiazolyl, benzofuranyl, thienyl, furyl, pyrrolyl, thiazolyl, oxazolyl, isoxazolyl, benzoxazolyl, benzoisoxazolyl, imidazolyl and the like. Because tautomers are theoretically possible, phthalimido is also considered aromatic. Typically, the ring systems contain 5-12 ring member atoms or 6-10 ring member atoms. In some embodiments, the aromatic or heteroaromatic moiety is a 6-membered aromatic rings system optionally containing 1-2 nitrogen atoms. More particularly, the moiety is an optionally substituted phenyl, pyridyl, indolyl, pyrimidyl, pyridazinyl, benzothiazolyl or benzimidazolyl, pyrazolyl, imidazolyl, isoxazolyl, thiazolyl, benzothiazolyl, indolyl. Even more particularly, such moiety is phenyl, pyridyl, or pyrimidyl and even more particularly, it is phenyl.
[0099] “O-aryl” or “O-heteroaryl” refers to aromatic or heteroaromatic systems which are coupled to another residue through an oxygen atom. A typical example of an O-aryl is phenoxy. Similarly, “arylalkyl” refers to aromatic and heteroaromatic systems which are coupled to another residue through a carbon chain, saturated or unsaturated, typically of 1-8C, 1-6C or more particularly 1-4C or 1-3C when saturated or 2-8C, 2-6C, 2-4C or 2-3C when unsaturated, including the heteroforms thereof. For greater certainty, arylalkyl thus includes an aryl or heteroaryl group as defined above connected to an alkyl, heteroalkyl, alkenyl, heteroalkenyl, alkynyl or heteroalkynyl moiety also as defined above. Typical arylalkyls would be an aryl(6-12C)alkyl(1-8C), aryl(6-12C)alkenyl(2-8C), or aryl(6-12C)alkynyl(2-8C), plus the heteroforms. A typical example is phenylmethyl, commonly referred to as benzyl.
[0100] Typical optional substituents on aromatic or heteroaromatic groups include independently halo, CN, NO 2 , CF 3 , OCF 3 , COOR′, CONR′ 2 , OR′, SR′, SOR′, SO 2 R′, NR′ 2 , NR′(CO)R′, NR′C(O)OR′, NR′C(O)NR′ 2 , NR′SO 2 NR′ 2 , or NR′SO 2 R′, wherein each R′ is independently H or an optionally substituted group selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, heteroaryl, and aryl (all as defined above); or the substituent may be an optionally substituted group selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteroalkynyl, aryl, heteroaryl, O-aryl, O-heteroaryl and arylalkyl.
[0101] Optional substituents on a non-aromatic group (e.g., alkyl, alkenyl, and alkynyl groups), are typically selected from the same list of substituents suitable for aromatic or heteroaromatic groups and may further be selected from ═O and ═NOR′ where R′ is H or an optionally substituted group selected from alkyl, alkenyl, alkynyl, heteroalkyl, heteroalkenyl, heteralkynyl, heteroaryl, and aryl (all as defined above).
[0102] Halo may be any halogen atom, especially F, Cl, Br, or I, and more particularly it is fluoro or chloro.
[0103] In general, a substituent group (e.g., alkyl, alkenyl, alkynyl, or aryl (including all heteroforms defined above) may itself optionally be substituted by additional substituents. The nature of these substituents is similar to those recited with regard to the substituents on the basic structures above. Thus, where an embodiment of a substituent is alkyl, this alkyl may optionally be substituted by the remaining substituents listed as substituents where this makes chemical sense, and where this does not undermine the size limit of alkyl per se; e.g., alkyl substituted by alkyl or by alkenyl would simply extend the upper limit of carbon atoms for these embodiments, and is not included. However, alkyl substituted by aryl, amino, halo and the like would be included. For example, where a group is substituted, the group may be substituted with 1, 2, 3, 4, 5, or 6 substituents. Optional substituents include, but are not limited to: 1C-6C alkyl or heteroaryl, 2C-6C alkenyl or heteroalkenyl, 2C-6C alkynyl or heteroalkynyl, halogen; aryl, heteroaryl, azido (—N 3 ), nitro (—NO 2 ), cyano (—CN), acyloxy(—OC(═O)R′), acyl (—C(═O)R′), alkoxy (—OR′), amido (—NR′C(═O)R″ or —C(═O)NRR′), amino (—NRR′), carboxylic acid (—CO 2 H), carboxylic ester (—CO 2 R′), carbamoyl (—OC(═O)NR′R″ or —NRC(═O)OR′), hydroxy (—OH), isocyano (—NC), sulfonate (—S(═O) 2 OR), sulfonamide (—S(═O) 2 NRR′ or —NRS(═O) 2 R′), or sulfonyl (—S(═O) 2 R), where each R or R′ is selected, independently, from H, 1C-6C alkyl or heteroaryl, 2C-6C alkenyl or heteroalkenyl, 2C-6C alkynyl or heteroalkynyl, aryl, or heteroaryl. A substituted group may have, for example, 1, 2, 3, 4, 5, 6, 7, 8, or 9 substituents.
[0104] The term an “effective amount” of an agent (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75), as used herein, is that amount sufficient to effect beneficial or desired results, such as clinical results, and, as such, an “effective amount” depends upon the context in which it is being applied. For example, in the context of administering an agent that is a modulator of a calcium channel (e.g., Ca V 3.1, Ca V 3.2, or Ca V 3.3), an effective amount of an agent is, for example, an amount sufficient to achieve a change in calcium channel activity as compared to the response obtained without administration of the agent.
[0105] The term “pharmaceutical composition,” as used herein, represents a composition containing a compound described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) formulated with a pharmaceutically acceptable excipient. In some embodiments, the pharmaceutical composition is manufactured or sold with the approval of a governmental regulatory agency as part of a therapeutic regimen for the treatment of disease in a mammal. Pharmaceutical compositions can be formulated, for example, for oral administration in unit dosage form (e.g., a tablet, capsule, caplet, gelcap, or syrup); for topical administration (e.g., as a cream, gel, lotion, or ointment); for intravenous administration (e.g., as a sterile solution free of particulate emboli and in a solvent system suitable for intravenous use); or in any other formulation described herein.
[0106] A “pharmaceutically acceptable excipient,” as used herein, refers any ingredient other than the compounds described herein (for example, a vehicle capable of suspending or dissolving the active compound) and having the properties of being nontoxic and non-inflammatory in a patient. Excipients may include, for example: antiadherents, antioxidants, binders, coatings, compression aids, disintegrants, dyes (colors), emollients, emulsifiers, fillers (diluents), film formers or coatings, flavors, fragrances, glidants (flow enhancers), lubricants, preservatives, printing inks, sorbents, suspensing or dispersing agents, sweeteners, or waters of hydration. Exemplary excipients include, but are not limited to: butylated hydroxytoluene (BHT), calcium carbonate, calcium phosphate (dibasic), calcium stearate, croscarmellose, crosslinked polyvinyl pyrrolidone, citric acid, crospovidone, cysteine, ethylcellulose, gelatin, hydroxypropyl cellulose, hydroxypropyl methylcellulose, lactose, magnesium stearate, maltitol, mannitol, methionine, methylcellulose, methyl paraben, microcrystalline cellulose, polyethylene glycol, polyvinyl pyrrolidone, povidone, pregelatinized starch, propyl paraben, retinyl palmitate, shellac, silicon dioxide, sodium carboxymethyl cellulose, sodium citrate, sodium starch glycolate, sorbitol, starch (corn), stearic acid, stearic acid, sucrose, talc, titanium dioxide, vitamin A, vitamin E, vitamin C, and xylitol.
[0107] The term “pharmaceutically acceptable prodrugs” as used herein, represents those prodrugs of the compounds of the present invention that are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and animals with undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use, as well as the zwitterionic forms, where possible, of the compounds of the invention.
[0108] The term “pharmaceutically acceptable salt,” as use herein, represents those salts of the compounds described here (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) that are, within the scope of sound medical judgment, suitable for use in contact with the tissues of humans and animals without undue toxicity, irritation, allergic response and the like and are commensurate with a reasonable benefit/risk ratio. Pharmaceutically acceptable salts are well known in the art. For example, pharmaceutically acceptable salts are described in: Berge et al., J. Pharmaceutical Sciences 66:1-19, 1977 and in Pharmaceutical Salts Properties, Selection, and Use , (Eds. P. H. Stahl and C. G. Wermuth), Wiley-VCH, 2008. The salts can be prepared in situ during the final isolation and purification of the compounds described herein or separately by reacting the free base group with a suitable organic acid.
[0109] The compounds of the invention may have ionizable groups so as to be capable of preparation as pharmaceutically acceptable salts. These salts may be acid addition salts involving inorganic or organic acids or the salts may, in the case of acidic forms of the compounds of the invention be prepared from inorganic or organic bases. Frequently, the compounds are prepared or used as pharmaceutically acceptable salts prepared as addition products of pharmaceutically acceptable acids or bases. Suitable pharmaceutically acceptable acids and bases are well-known in the art, such as hydrochloric, sulphuric, hydrobromic, acetic, lactic, citric, or tartaric acids for forming acid addition salts, and potassium hydroxide, sodium hydroxide, ammonium hydroxide, caffeine, various amines, and the like for forming basic salts. Methods for preparation of the appropriate salts are well-established in the art.
[0110] Representative acid addition salts include acetate, adipate, alginate, ascorbate, aspartate, benzenesulfonate, benzoate, bisulfate, borate, butyrate, camphorate, camphorsulfonate, citrate, cyclopentanepropionate, digluconate, dodecylsulfate, ethanesulfonate, fumarate, glucoheptonate, glycerophosphate, hemisulfate, heptonate, hexanoate, hydrobromide, hydrochloride, hydroiodide, 2-hydroxy-ethanesulfonate, lactobionate, lactate, laurate, lauryl sulfate, malate, maleate, malonate, methanesulfonate, 2-naphthalenesulfonate, nicotinate, nitrate, oleate, oxalate, palmitate, pamoate, pectinate, persulfate, 3-phenylpropionate, phosphate, picrate, pivalate, propionate, stearate, succinate, sulfate, tartrate, thiocyanate, toluenesulfonate, undecanoate, valerate salts and the like. Representative alkali or alkaline earth metal salts include sodium, lithium, potassium, calcium, magnesium and the like, as well as nontoxic ammonium, quaternary ammonium, and amine cations, including, but not limited to ammonium, tetramethylammonium, tetraethylammonium, methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine and the like.
[0111] The term “pharmaceutically acceptable solvate” as used herein means a compound as described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) where molecules of a suitable solvent are incorporated in the crystal lattice. A suitable solvent is physiologically tolerable at the dosage administered. For example, solvates may be prepared by crystallization, recrystallization, or precipitation from a solution that includes organic solvents, water, or a mixture thereof. Examples of suitable solvents are ethanol, water (for example, mono-, di-, and tri-hydrates), N-methylpyrrolidinone (NMP), dimethyl sulfoxide (DMSO), N,N′-dimethylformamide (DMF), N,N′-dimethylacetamide (DMAC), 1,3-dimethyl-2-imidazolidinone (DMEU), 1,3-dimethyl-3,4,5,6-tetrahydro-2-(1H)-pyrimidinone (DMPU), acetonitrile (ACN), propylene glycol, ethyl acetate, benzyl alcohol, 2-pyrrolidone, benzyl benzoate, and the like. When water is the solvent, the molecule is referred to as a “hydrate.”
[0112] The term “prevent,” as used herein, refers to prophylactic treatment or treatment that prevents one or more symptoms or conditions of a disease, disorder, or conditions described herein (for example, pain (e.g., chronic or acute pain), epilepsy, Alzheimer's disease, Parkinson's disease, cardiovascular disease, diabetes, cancer, sleep disorders, obesity, psychosis such as schizophrenia, overactive bladder, renal disease, neuroprotection, addiction, and male birth control). Preventative treatment can be initiated, for example, prior to (“pre-exposure prophylaxis”) or following (“post-exposure prophylaxis”) an event that precedes the onset of the disease, disorder, or conditions. Preventive treatment that includes administration of a compound described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1), or a pharmaceutically acceptable salt or solvate thereof, or a pharmaceutical composition thereof, can be acute, short-term, or chronic. The doses administered may be varied during the course of preventative treatment.
[0113] The term “prodrug,” as used herein, represents compounds that are rapidly transformed in vivo to the parent compound of the above formula, for example, by hydrolysis in blood. Prodrugs of the compounds described herein may be conventional esters. Some common esters that have been utilized as prodrugs are phenyl esters, aliphatic (C1-C8 or C8-C24) esters, cholesterol esters, acyloxymethyl esters, carbamates, and amino acid esters. For example, a compound that contains an OH group may be acylated at this position in its prodrug form. A thorough discussion is provided in T. Higuchi and V. Stella, Pro - drugs as Novel Delivery Systems , Vol. 14 of the A.C.S. Symposium Series, Edward B. Roche, ed., Bioreversible Carriers in Drug Design , American Pharmaceutical Association and Pergamon Press, 1987, and Judkins et al., Synthetic Communications 26(23):4351-4367, 1996, each of which is incorporated herein by reference. Preferably, prodrugs of the compounds of the present invention are suitable for use in contact with the tissues of humans and animals with undue toxicity, irritation, allergic response, and the like, commensurate with a reasonable benefit/risk ratio, and effective for their intended use.
[0114] In addition, the compounds of the invention may be coupled through conjugation to substances designed to alter the pharmacokinetics, for targeting, or for other reasons. Thus, the invention further includes conjugates of these compounds. For example, polyethylene glycol is often coupled to substances to enhance half-life; the compounds may be coupled to liposomes covalently or noncovalently or to other particulate carriers. They may also be coupled to targeting agents such as antibodies or peptidomimetics, often through linker moieties. Thus, the invention is also directed to compounds (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) when modified so as to be included in a conjugate of this type.
[0115] As used herein, and as well understood in the art, “to treat” a condition or “treatment” of the condition (e.g., the conditions described herein such as pain (e.g., chronic or acute pain), epilepsy, Alzheimer's disease, Parkinson's disease, cardiovascular disease, diabetes, cancer, sleep disorders, obesity, psychosis such as schizophrenia, overactive bladder, renal disease, neuroprotection, addiction, and male birth control) is an approach for obtaining beneficial or desired results, such as clinical results. Beneficial or desired results can include, but are not limited to, alleviation or amelioration of one or more symptoms or conditions; diminishment of extent of disease, disorder, or condition; stabilized (i.e., not worsening) state of disease, disorder, or condition; preventing spread of disease, disorder, or condition; delay or slowing the progress of the disease, disorder, or condition; amelioration or palliation of the disease, disorder, or condition; and remission (whether partial or total), whether detectable or undetectable. “Palliating” a disease, disorder, or condition means that the extent and/or undesirable clinical manifestations of the disease, disorder, or condition are lessened and/or time course of the progression is slowed or lengthened, as compared to the extent or time course in the absence of treatment.
[0116] The term “unit dosage form” refers to a physically discrete unit suitable as a unitary dosage for human subjects and other mammals, each unit containing a predetermined quantity of active material calculated to produce the desired therapeutic effect, in association with any suitable pharmaceutical excipient or excipients. Exemplary, non-limiting unit dosage forms include a tablet (e.g., a chewable tablet), caplet, capsule (e.g., a hard capsule or a soft capsule), lozenge, film, strip, gelcap, and syrup.
[0117] In some cases, the compounds of the invention contain one or more chiral centers. The invention includes each of the isolated stereoisomeric forms as well as mixtures of stereoisomers in varying degrees of chiral purity, including racemic mixtures. It also encompasses the various diastereomers and tautomers that can be formed.
[0118] Other features and advantages of the invention will be apparent from the following detailed description, the drawing, and the claims.
BRIEF DESCRIPTION OF THE DRAWING
[0119] FIG. 1 shows separation of a racemic sample of a compound of Formula (I) into two enantiomers using chiral HPLC chromatography.
DETAILED DESCRIPTION OF THE INVENTION
Compounds
[0120] The invention features compounds according to Formula (I),
[0000]
[0000] or a pharmaceutically acceptable salt, solvate, or prodrug thereof, or a stereoisomer thereof, or a conjugate thereof, where
[0121] Ar is phenyl or a 5-6 membered heteroaryl ring containing at least one heteroatom selected from N, O and S as a ring member, and optionally substituted with at least one R 8 , R 9 , or R 10 ;
[0122] T is CH 2 , O, or NR 1 ;
[0123] A is [T]-C(O)—NR 1 or [T]-NR 1 —C(O)— or [T]-C(O)—O—, or [T]-O—C(O)—, —NR 1 —C(O)—NR 1 —; [T]-O—C(O)—NR 1 —; or [T]-NR 1 —C(O)—O—; where [T] indicates which atom of A is linked to T in Formula (II);
[0124] R 1 and R 2 are independently selected from the group consisting of H, optionally substituted C1-C6 alkyl, C1-C6 optionally substituted alkylsulfonyl, and optionally substituted C1-C6 acyl;
[0125] R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from H, optionally substituted C1-C6 alkyl, halo, hydroxy, CN, optionally substituted C1-C6 alkoxy, and optionally substituted C1-C6 heteroalkyl;
[0126] where R 2 and R 3 , or R 3 and R 4 , or R 4 and R 5 , or R 6 and R 2 , or two R 6 if two R 6 are present (any one of these pairs, but not more than one pair) can optionally be taken together to form a non-aromatic 5-6 membered ring, which can optionally include up to two heteroatoms selected from N, O and S as ring members;
[0127] and two R 7 can optionally be taken together to form a non-aromatic 5-6 membered ring, which can optionally include a heteroatom selected from N, O and S as a ring member
[0128] m and n are independently 1 or 2;
[0129] p is 0-2;
[0130] q is 0, 1 or 2;
[0131] R 8 , R 9 , and R 10 are optional substituents that are independently selected from the group consisting of H, halogen, CN, —SO 2 —(C1-C4 alkyl), optionally substituted C1-C6 alkyl, optionally substituted C1-C6 alkoxy, optionally substituted aryl, and optionally substituted heteroaryl, provided at least one of R 8 , R 9 , and R 10 is present and is not H.
[0132] Other compounds are also described by any of Formulas (II)-(XIII) as described herein:
[0000]
[0133] Representative compounds of the invention include Compounds 1-75 of Table 1. Exemplary methods of synthesis and uses of these compounds are also described.
Utility and Administration
[0134] The compounds described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) are useful in the methods of the invention and, while not bound by theory, are believed to exert their desirable effects through their ability to modulate the activity of calcium channels, particularly the activity of T-type calcium channels. This makes them useful for treatment of certain conditions where modulation of calcium channels (e.g., T-type calcium channels such as Ca V 3.1, Ca V 3.2, or Ca V 3.3), is desired including pain, epilepsy, migraine, Parkinson's disease, depression, schizophrenia, psychosis, and tinnitus.
Modulation of Calcium Channels
[0135] The entry of calcium into cells through voltage-gated calcium channels mediates a wide variety of cellular and physiological responses, including excitation-contraction coupling, hormone secretion and gene expression (e.g., Miller et al., Science 235:46-52 (1987); Augustine et al., Annu Rev Neurosci 10: 633-693 (1987)). In neurons, calcium channels directly affect membrane potential and contribute to electrical properties such as excitability, repetitive firing patterns and pacemaker activity. Calcium entry further affects neuronal functions by directly regulating calcium-dependent ion channels and modulating the activity of calcium-dependent enzymes such as protein kinase C and calmodulin-dependent protein kinase II. An increase in calcium concentration at the presynaptic nerve terminal triggers the release of neurotransmitter, which also affects neurite outgrowth and growth cone migration in developing neurons.
[0136] Calcium channels mediate a variety of normal physiological functions, and are also implicated in a number of human disorders as described herein. For example, calcium channels also have been shown to mediate the development and maintenance of the neuronal sensitization and hyperexcitability processes associated with neuropathic pain, and provide attractive targets for the development of analgesic drugs (reviewed in Vanegas et al., Pain 85: 9-18 (2000)). Native calcium channels have been classified by their electrophysiological and pharmacological properties into T-, L-, N-, P/Q- and R-types (reviewed in Catterall, Annu Rev Cell Dev Biol 16: 521-555, 2000; Huguenard, Annu Rev Physiol 58: 329-348, 1996). The L-, N- and P/Q-type channels activate at more positive potentials (high voltage-activated) and display diverse kinetics and voltage-dependent properties (Id.). T-type channels can be distinguished by having a more negative range of activation and inactivation, rapid inactivation, slow deactivation, and smaller single-channel conductances. There are three subtypes of T-type calcium channels that have been molecularly, pharmacologically, and elecrophysiologically identified: these subtypes have been termed α 1G , α 1H , and α 1I (alternately called Ca V 3.1, Ca V 3.2 and Ca V 3.3 respectively).
[0137] T-type calcium channels are involved in various medical conditions. In mice lacking the gene expressing the 3.1 subunit, resistance to absence seizures was observed (Kim et al., Mol. Cell Neurosci. 18(2): 235-245 (2001)). Other studies have also implicated the 3.2 subunit in the development of epilepsy (Su et al., J. Neurosci. 22: 3645-3655 (2002)). There is also evidence that some existing anticonvulsant drugs, such as ethosuximide, function through the blockade of T-type channels (Gomora et al., Mol. Pharmacol. 60: 1121-1132 (2001)).
[0138] Low voltage-activated calcium channels are highly expressed in tissues of the cardiovascular system. There is also a growing body of evidence that suggests that T-type calcium channels are abnormally expressed in cancerous cells and that blockade of these channels may reduce cell proliferation in addition to inducing apoptosis. Recent studies also show that the expression of T-type calcium channels in breast cancer cells is proliferation state dependent, i.e. the channels are expressed at higher levels during the fast-replication period, and once the cells are in a non-proliferation state, expression of this channel is minimal. Therefore, selectively blocking calcium channel entry into cancerous cells may be a valuable approach for preventing tumor growth (e.g., PCT Patent Publication Nos. WO 05/086971 and WO 05/77082; Taylor et al., World J. Gastroenterol. 14(32): 4984-4991 (2008); Heo et al., Biorganic & Medicinal Chemistry Letters 18:3899-3901 (2008)).
[0139] T-type calcium channels may also be involved in still other conditions. A recent study also has shown that T-type calcium channel antagonists inhibit high-fat diet-induced weight gain in mice. In addition, administration of a selective T-type channel antagonist reduced body weight and fat mass while concurrently increasing lean muscle mass (e.g., Uebele et al., The Journal of Clinical Investigation, 119(6):1659-1667 (2009)). T-type calcium channels may also be involved in pain (see for example: US Patent Publication No. 2003/0086980; PCT Publication Nos. WO 03/007953 and WO 04/000311). In addition to cardiovascular disease, epilepsy (see also US Patent Publication No. 2006/0025397), cancer, and chronic or acute pain, T-type calcium channels have been implicated in diabetes (US Patent Publication No. 2003/0125269), sleep disorders (US Patent Publication No. 2006/0003985), Parkinson's disease and psychosis such as schizophrenia (US Patent Publication No. 2003/0087799); overactive bladder (Sui et al., British Journal of Urology International 99(2): 436-441 (2007); US Patent Publication No. 2004/0197825), renal disease (Hayashi et al., Journal of Pharmacological Sciences 99: 221-227 (2005)), anxiety and alcoholism (US Patent Publication No. 2009/0126031), neuroprotection, and male birth control.
[0140] The modulation of ion channels by the compounds described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) can be measured according to methods known in the art (e.g., in the references provided herein). Modulators of ion channels, e.g., voltage gated calcium ion channels, and the medicinal chemistry or methods by which such compounds can be identified, are also described in, for example: Birch et al., Drug Discovery Today, 9(9):410-418 (2004); Audesirk, “Chapter 6—Electrophysiological Analysis of Ion Channel Function,” Neurotoxicology: Approaches and Methods, 137-156 (1995); Camerino et al., “Chapter 4: Therapeutic Approaches to Ion Channel Diseases,” Advances in Genetics, 64:81-145 (2008); Petkov, “Chapter 16—Ion Channels,” Pharmacology: Principles and Practice, 387-427 (2009); Standen et al., “Chapter 15—Patch Clamping Methods and Analysis of Ion Channels,” Principles of Medical Biology , Vol. 7, Part 2, 355-375 (1997); Xu et al., Drug Discovery Today, 6(24):1278-1287 (2001); and Sullivan et al., Methods Mol. Biol. 114:125-133 (1999). Exemplary experimental methods are also provided in the Examples.
Diseases and Conditions
[0141] Exemplary conditions that can be treated using the compounds described herein include pain (e.g., chronic or acute pain), epilepsy, Alzheimer's disease, Parkinson's disease, diabetes; cancer; sleep disorders; obesity; psychosis such as schizophrenia; overactive bladder; renal disease, neuroprotection, and addiction. For example, the condition can be pain (e.g., neuropathic pain or post-surgery pain), epilepsy, migraine, Parkinson's disease, depression, schizophrenia, psychosis, or tinnitus.
[0142] Epilepsy as used herein includes but is not limited to partial seizures such as temporal lobe epilepsy, absence seizures, generalized seizures, and tonic/clonic seizures.
[0143] Cancer as used herein includes but is not limited to breast carcinoma, neuroblastoma, retinoblastoma, glioma, prostate carcinoma, esophageal carcinoma, fibrosarcoma, colorectal carcinoma, pheochromocytoma, adrenocarcinoma, insulinoma, lung carcinoma, melanoma, and ovarian cancer.
[0144] Acute pain as used herein includes but is not limited to nociceptive pain and post-operative pain. Chronic pain includes but is not limited by: peripheral neuropathic pain such as post-herpetic neuralgia, diabetic neuropathic pain, neuropathic cancer pain, failed back-surgery syndrome, trigeminal neuralgia, and phantom limb pain; central neuropathic pain such as multiple sclerosis related pain, Parkinson disease related pain, post-stroke pain, post-traumatic spinal cord injury pain, and pain in dementia; musculoskeletal pain such as osteoarthritic pain and fibromyalgia syndrome; inflammatory pain such as rheumatoid arthritis and endometriosis; headache such as migraine, cluster headache, tension headache syndrome, facial pain, headache caused by other diseases; visceral pain such as interstitial cystitis, irritable bowel syndrome and chronic pelvic pain syndrome; and mixed pain such as lower back pain, neck and shoulder pain, burning mouth syndrome and complex regional pain syndrome.
[0145] In treating osteoarthritic pain, joint mobility can also improve as the underlying chronic pain is reduced. Thus, use of compounds of the present invention to treat osteoarthritic pain inherently includes use of such compounds to improve joint mobility in patients suffering from osteoarthritis.
[0146] The compounds described herein can be tested for efficacy in any standard animal model of pain. Various models test the sensitivity of normal animals to intense or noxious stimuli (physiological or nociceptive pain). These tests include responses to thermal, mechanical, or chemical stimuli. Thermal stimuli usually involve the application of hot stimuli (typically varying between 42-55° C.) including, for example: radiant heat to the tail (the tail flick test), radiant heat to the plantar surface of the hindpaw (the Hargreaves test), the hotplate test, and immersion of the hindpaw or tail into hot water. Immersion in cold water, acetone evaporation, or cold plate tests may also be used to test cold pain responsiveness. Tests involving mechanical stimuli typically measure the threshold for eliciting a withdrawal reflex of the hindpaw to graded strength monofilament von Frey hairs or to a sustained pressure stimulus to a paw (e.g., the Ugo Basile analgesiometer). The duration of a response to a standard pinprick may also be measured. When using a chemical stimulus, the response to the application or injection of a chemical irritant (e.g., capsaicin, mustard oil, bradykinin, ATP, formalin, acetic acid) to the skin, muscle joints or internal organs (e.g., bladder or peritoneum) is measured.
[0147] In addition, various tests assess pain sensitization by measuring changes in the excitability of the peripheral or central components of the pain neural pathway. In this regard, peripheral sensitization (i.e., changes in the threshold and responsiveness of high threshold nociceptors) can be induced by repeated heat stimuli as well as the application or injection of sensitizing chemicals (e.g., prostaglandins, bradykinin, histamine, serotonin, capsaicin, or mustard oil). Central sensitization (i.e., changes in the excitability of neurons in the central nervous system induced by activity in peripheral pain fibers) can be induced by noxious stimuli (e.g., heat), chemical stimuli (e.g., injection or application of chemical irritants), or electrical activation of sensory fibers.
[0148] Various pain tests developed to measure the effect of peripheral inflammation on pain sensitivity can also be used to study the efficacy of the compounds (Stein et al., Pharmacol. Biochem. Behav . (1988) 31: 445-451; Woolf et al., Neurosci . (1994) 62: 327-331). Additionally, various tests assess peripheral neuropathic pain using lesions of the peripheral nervous system. One such example is the “axotomy pain model” (Watson, J. Physiol . (1973) 231:41). Other similar tests include the SNL test which involves the ligation of a spinal segmental nerve (Kim and Chung Pain (1992) 50: 355), the Seltzer model involving partial nerve injury (Seltzer, Pain (1990) 43: 205-18), the spared nerve injury (SNI) model (Decosterd and Woolf, Pain (2000) 87:149), chronic constriction injury (CCl) model (Bennett (1993) Muscle Nerve 16: 1040), tests involving toxic neuropathies such as diabetes (streptozocin model), pyridoxine neuropathy, taxol, vincristine, and other antineoplastic agent-induced neuropathies, tests involving ischaemia to a nerve, peripheral neuritis models (e.g., CFA applied peri-neurally), models of post-herpetic neuralgia using HSV infection, and compression models.
[0149] In all of the above tests, outcome measures may be assessed, for example, according to behavior, electrophysiology, neurochemistry, or imaging techniques to detect changes in neural activity.
[0150] Exemplary models of pain are also described in the Examples provided herein.
[0151] In addition to being able to modulate a particular calcium channel (e.g., Ca V 3.1, Ca V 3.2, or Ca V 3.3), it may be desirable that the compound has very low activity with respect to the hERG K + channel, which is expressed in the heart: compounds that block this channel with high potency may cause reactions which are fatal. See, e.g., Bowlby et al., “hERG (KCNH2 or K V 11.1 K + Channels: Screening for Cardiac Arrhythmia Risk,” Curr. Drug Metab. 9(9):965-70 (2008)). Thus, for a compound that modulates calcium channel activity, it may also be shown that the hERG K + channel is not inhibited or only minimally inhibited as compared to the inhibition of the primary channel targeted. Similarly, it may be desirable that the compound does not inhibit cytochrome p450, an enzyme that is required for drug detoxification. Such compounds may be particularly useful in the methods described herein.
[0152] It is known that calcium channel activity is involved in a multiplicity of disorders, and particular types of channels are associated with particular conditions. The association of T-type channels in conditions associated with neural transmission would indicate that compounds of the invention which target T-type receptors are most useful in these conditions. The compounds described herein, e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1, can exhibit a high selectivity for T-type channels. Thus, as described below, they can be studied for their ability to interact specifically with T-type channels as an indication of desirable function and selectiviey. It is desirable that the compounds exhibit IC 50 values of <1 μM for T-type calcium channels. In one embodiment, the IC 50 is less than 0.50 μM. In one embodiment the IC 50 is less than 0.01 μM. In one embodiment, the IC 50 is between 0.01 μM and 0.1 μM. In still another embodiment, the IC 50 is between 0.1 μM and 0.5 μM. In other embodiments, the IC 50 is between 0.5-1 μM. The IC 50 is the concentration which inhibits 50% of the calcium, barium or other permeant divalent cation flux at a particular applied potential.
[0153] Compound 3 from Table 1 herein was tested in such additional assays, and exhibited negligible hERG activity, and less than 10% inhibition of various cytochromes (2C9, 2D6, 3A4) at 10 micromolar.
[0154] The compounds of the invention modulate the activity of calcium channels; in general, said modulation is the inhibition of the ability of the channel to transport calcium. As described below, the effect of a particular compound on calcium channel activity can readily be ascertained in a routine assay whereby the conditions are arranged so that the channel is activated, and the effect of the compound on this activation (either positive or negative) is assessed. Exemplary assays are also described in the Examples.
Pharmaceutical Compositions
[0155] For use as treatment of human and animal subjects, the compounds of the invention can be formulated as pharmaceutical or veterinary compositions. Depending on the subject to be treated, the mode of administration, and the type of treatment desired—e.g., prevention, prophylaxis, or therapy—the compounds are formulated in ways consonant with these parameters. A summary of such techniques is found in Remington: The Science and Practice of Pharmacy, 21 st Edition , Lippincott Williams & Wilkins, (2005); and Encyclopedia of Pharmaceutical Technology , eds. J. Swarbrick and J. C. Boylan, 1988-1999, Marcel Dekker, New York, each of which is incorporated herein by reference.
[0156] The compounds described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) may be present in amounts totaling 1-95% by weight of the total weight of the composition. The composition may be provided in a dosage form that is suitable for intraarticular, oral, parenteral (e.g., intravenous, intramuscular), rectal, cutaneous, subcutaneous, topical, transdermal, sublingual, nasal, vaginal, intravesicular, intraurethral, intrathecal, epidural, aural, or ocular administration, or by injection, inhalation, or direct contact with the nasal, genitourinary, gastrointesitnal, reproductive or oral mucosa. Thus, the pharmaceutical composition may be in the form of, e.g., tablets, capsules, pills, powders, granulates, suspensions, emulsions, solutions, gels including hydrogels, pastes, ointments, creams, plasters, drenches, osmotic delivery devices, suppositories, enemas, injectables, implants, sprays, preparations suitable for iontophoretic delivery, or aerosols. The compositions may be formulated according to conventional pharmaceutical practice.
[0157] In general, for use in treatment, the compounds described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) may be used alone, as mixtures of two or more compounds or in combination with other pharmaceuticals. An example of other pharmaceuticals to combine with the compounds described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) would include pharmaceuticals for the treatment of the same indication. For example, in the treatment of pain, a compound may be combined with another pain relief treatment such as an NSAID, or a compound which selectively inhibits COX-2, or an opioid, or an adjuvant analgesic such as an antidepressant. Another example of a potential pharmaceutical to combine with the compounds described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) would include pharmaceuticals for the treatment of different yet associated or related symptoms or indications. Depending on the mode of administration, the compounds will be formulated into suitable compositions to permit facile delivery. Each compound of a combination therapy may be formulated in a variety of ways that are known in the art. For example, the first and second agents of the combination therapy may be formulated together or separately. Desirably, the first and second agents are formulated together for the simultaneous or near simultaneous administration of the agents.
[0158] The compounds of the invention may be prepared and used as pharmaceutical compositions comprising an effective amount of a compound described herein (e.g., a compound according to any of Formulas (I)-(XIII) or any of Compounds 1-75 in Table 1) and a pharmaceutically acceptable carrier or excipient, as is well known in the art. In some embodiments, the composition includes at least two different pharmaceutically acceptable excipients or carriers.
[0159] Formulations may be prepared in a manner suitable for systemic administration or topical or local administration. Systemic formulations include those designed for injection (e.g., intramuscular, intravenous or subcutaneous injection) or may be prepared for transdermal, transmucosal, or oral administration. The formulation will generally include a diluent as well as, in some cases, adjuvants, buffers, preservatives and the like. The compounds can be administered also in liposomal compositions or as microemulsions.
[0160] For injection, formulations can be prepared in conventional forms as liquid solutions or suspensions or as solid forms suitable for solution or suspension in liquid prior to injection or as emulsions. Suitable excipients include, for example, water, saline, dextrose, glycerol and the like. Such compositions may also contain amounts of nontoxic auxiliary substances such as wetting or emulsifying agents, pH buffering agents and the like, such as, for example, sodium acetate, sorbitan monolaurate, and so forth.
[0161] Various sustained release systems for drugs have also been devised. See, for example, U.S. Pat. No. 5,624,677, which is herein incorporated by reference.
[0162] Systemic administration may also include relatively noninvasive methods such as the use of suppositories, transdermal patches, transmucosal delivery and intranasal administration. Oral administration is also suitable for compounds of the invention. Suitable forms include syrups, capsules, and tablets, as is understood in the art.
[0163] For administration to animal or human subjects, the dosage of the compounds of the invention may be, for example, 0.01-50 mg/kg (e.g., 0.01-15 mg/kg or 0.1-10 mg/kg). For example, the dosage can be 10-30 mg/kg.
[0164] Each compound of a combination therapy, as described herein, may be formulated in a variety of ways that are known in the art. For example, the first and second agents of the combination therapy may be formulated together or separately.
[0165] The individually or separately formulated agents can be packaged together as a kit. Non-limiting examples include, but are not limited to, kits that contain, e.g., two pills, a pill and a powder, a suppository and a liquid in a vial, two topical creams, etc. The kit can include optional components that aid in the administration of the unit dose to patients, such as vials for reconstituting powder forms, syringes for injection, customized IV delivery systems, inhalers, etc. Additionally, the unit dose kit can contain instructions for preparation and administration of the compositions. The kit may be manufactured as a single use unit dose for one patient, multiple uses for a particular patient (at a constant dose or in which the individual compounds may vary in potency as therapy progresses); or the kit may contain multiple doses suitable for administration to multiple patients (“bulk packaging”). The kit components may be assembled in cartons, blister packs, bottles, tubes, and the like.
[0166] Formulations for oral use include tablets containing the active ingredient(s) in a mixture with non-toxic pharmaceutically acceptable excipients. These excipients may be, for example, inert diluents or fillers (e.g., sucrose, sorbitol, sugar, mannitol, microcrystalline cellulose, starches including potato starch, calcium carbonate, sodium chloride, lactose, calcium phosphate, calcium sulfate, or sodium phosphate); granulating and disintegrating agents (e.g., cellulose derivatives including microcrystalline cellulose, starches including potato starch, croscarmellose sodium, alginates, or alginic acid); binding agents (e.g., sucrose, glucose, sorbitol, acacia, alginic acid, sodium alginate, gelatin, starch, pregelatinized starch, microcrystalline cellulose, magnesium aluminum silicate, carboxymethylcellulose sodium, methylcellulose, hydroxypropyl methylcellulose, ethylcellulose, polyvinylpyrrolidone, or polyethylene glycol); and lubricating agents, glidants, and antiadhesives (e.g., magnesium stearate, zinc stearate, stearic acid, silicas, hydrogenated vegetable oils, or talc). Other pharmaceutically acceptable excipients can be colorants, flavoring agents, plasticizers, humectants, buffering agents, and the like.
[0167] Two or more compounds may be mixed together in a tablet, capsule, or other vehicle, or may be partitioned. In one example, the first compound is contained on the inside of the tablet, and the second compound is on the outside, such that a substantial portion of the second compound is released prior to the release of the first compound.
[0168] Formulations for oral use may also be provided as chewable tablets, or as hard gelatin capsules wherein the active ingredient is mixed with an inert solid diluent (e.g., potato starch, lactose, microcrystalline cellulose, calcium carbonate, calcium phosphate or kaolin), or as soft gelatin capsules wherein the active ingredient is mixed with water or an oil medium, for example, peanut oil, liquid paraffin, or olive oil. Powders, granulates, and pellets may be prepared using the ingredients mentioned above under tablets and capsules in a conventional manner using, e.g., a mixer, a fluid bed apparatus or a spray drying equipment.
[0169] Dissolution or diffusion controlled release can be achieved by appropriate coating of a tablet, capsule, pellet, or granulate formulation of compounds, or by incorporating the compound into an appropriate matrix. A controlled release coating may include one or more of the coating substances mentioned above and/or, e.g., shellac, beeswax, glycowax, castor wax, carnauba wax, stearyl alcohol, glyceryl monostearate, glyceryl distearate, glycerol palmitostearate, ethylcellulose, acrylic resins, dl-polylactic acid, cellulose acetate butyrate, polyvinyl chloride, polyvinyl acetate, vinyl pyrrolidone, polyethylene, polymethacrylate, methylmethacrylate, 2-hydroxymethacrylate, methacrylate hydrogels, 1,3 butylene glycol, ethylene glycol methacrylate, and/or polyethylene glycols. In a controlled release matrix formulation, the matrix material may also include, e.g., hydrated methylcellulose, carnauba wax and stearyl alcohol, carbopol 934, silicone, glyceryl tristearate, methyl acrylate-methyl methacrylate, polyvinyl chloride, polyethylene, and/or halogenated fluorocarbon.
[0170] The liquid forms in which the compounds and compositions of the present invention can be incorporated for administration orally include aqueous solutions, suitably flavored syrups, aqueous or oil suspensions, and flavored emulsions with edible oils such as cottonseed oil, sesame oil, coconut oil, or peanut oil, as well as elixirs and similar pharmaceutical vehicles.
[0171] Generally, when administered to a human, the oral dosage of any of the compounds of the combination of the invention will depend on the nature of the compound, and can readily be determined by one skilled in the art. Typically, such dosage is normally about 0.001 mg to 2000 mg per day, desirably about 1 mg to 1000 mg per day, and more desirably about 5 mg to 500 mg per day. Dosages up to 200 mg per day may be necessary.
[0172] Administration of each drug in a combination therapy, as described herein, can, independently, be one to four times daily for one day to one year, and may even be for the life of the patient. Chronic, long-term administration may be indicated.
Synthesis
[0173] The following reaction schemes and examples are intended to illustrate the synthesis of a representative number of compounds. Accordingly, the following examples are intended to illustrate but not to limit the invention. Additional compounds not specifically exemplified may be synthesized using conventional methods and known starting materials in combination with the methods described hereinbelow.
Example 1
Synthesis of N-(3,5-bis(trifluoromethyl)phenyl)-2-(piperidin-4-yl)acetamide hydrochloride (4)
[0174]
[0175] 3,5-Bis(trifluoromethyl)aniline (1) (20.6 g, 90.0 mmol), 2-(1-(tert-butoxycarbonyl)piperidin-4-yl)acetic acid (2) (19.5 g, 80.2 mmol), DIPEA (12.9 g, 100 mmol) and HATU (31.5 g, 82.9 mmol) were stirred in DMF (150 mL) at 50° C. for 48 h. The solvent was removed in vacuo, and the residue taken up in DCM, washed sequentially with saturated NH 4 Cl solution, saturated NaHCO 3 solution, and water, dried, and concentrated in-vacuo. The residue was purified by flash column chromatography (15-30% EtOAc/PE) followed by recrystallization from EtOAc/hexanes to give tert-butyl 4-(2-(3,5-bis(trifluoromethyl)phenylamino)-2-oxoethyl)piperidine-1-carboxylate (3).
[0176] The solid was dissolved in EtOAc (150 mL), HCl (g) was bubbled through the solution for 5 min, and the reaction was stirred at room temperature for 30 min and at 0° C. for 30 min. The resultant solid was collected by filtration to give N-(3,5-bis(trifluoromethyl)phenyl)-2-(piperidin-4-yl)acetamide hydrochloride (4) (24.0 g, 77%): 1 H NMR (300 mHz—D 2 O) δ 1.41 (q, 2H, J=11.4 Hz), 1.88 (d, J=2 H, J=14.3 Hz), 2.03 (m, 1H), 2.35 (d, 2H, J=7.14 Hz), 2.91 (t, 2H, 12.78 Hz), 3.33 (d, 2 H, J=12.6 Hz), 7.74 (s, 1H), 7.87 (s, 2H).
Example 2
Synthesis of N-(3,5-bis(trifluoromethyl)phenyl)-2-(pyrrolidin-3-yl)acetamide (7)
[0177]
[0178] 3,5-Bis(trifluoromethyl)aniline (1) (4.58 g, 20.0 mmol), N-Boc-3-pyrrolidine acetic acid (5) (4.0 g, 17.4 mmol), DIPEA (5.2 mL, 30 mmol) and HATU (9.5 g, 25 mmol) were stirred in DMF (40 mL) at 40° C. for 72 h. The reaction was diluted with saturated NH 4 Cl solution, extracted with Et 2 O, washed with saturated NaHCO 3 solution, dried, and concentrated in vacuo. The residue was purified by automated column chromatography (0-40% EtOAc, PE) to give tert-butyl 3-(2-(3,5-bis(trifluoromethyl)phenylamino)-2-oxoethyl)pyrrolidine-1-carboxylate (6).
[0179] The solid was taken up in EtOAc (30 mL), HCl (g) was bubbled through the solution for 30 secs, then it was stirred at room temperature for 1 h and concentrated in-vacuo. The residue was taken up in EtOAc/PE (1/5). The resultant precipitate was collected by filtration, dissolved in H 2 O (50 mL), basified with saturated K 2 CO 3 solution, and extracted with EtOAc. The organics were dried and concentrated in vacuo to give N-(3,5-bis(trifluoromethyl)phenyl)-2-(pyrrolidin-3-yl)acetamide (7) (4.8 g, 81%). The product structure was confirmed by LCMS.
Example 3
Synthesis of 2-(azetidin-3-yl)-N-(3,5-bis(trifluoromethyl)phenyl)acetamide (10)
[0180]
[0181] 3,5-Bis(trifluoromethyl)aniline (1) (5.04 g, 22.0 mmol), 2-(1-(tert-butoxycarbonyl)azetidin-3-yl)acetic acid (8) (4.5 g, 20.9 mmol), DIPEA (5.2 mL, 30 mmol) and HATU (10.6 g, 28 mmol) were stirred in DMF (40 mL) at 40° C. for 72 h. The reaction was diluted with saturated NH 4 Cl solution, extracted with Et 2 O, washed with saturated NaHCO 3 solution, dried, concentrated in-vacuo and the residue purified by automated column chromatography (0-50% EtOAc, PE) to provide tert-butyl 3-(2-(3,5-bis(trifluoromethyl)phenylamino)-2-oxoethyl)azetidine-1-carboxylate (9). A mixture of this compound (2.75 g, 6.46 mmol) and ZnBr 2 (5.00 g, 22.2 mmol), was stirred in the presence of molecular sieves in DCM at room temperature for 6 h. NH 3 OH/H 2 O (30 mL/30 mL) was added, and the reaction stirred at room temperature for 2 h. At this time, the organics were separated (extracting with additional DCM), and the combined organics were dried and concentrated in vacuo to give 2-(azetidin-3-yl)-N-(3,5-bis(trifluoromethyl)phenyl)acetamide (10) (1.91 g, 90%), estimated 75% purity by 1 H NMR; 1 H NMR (300 mHz—CDCl 3 ) δ 2.71 (m, 6H), 3.06 (m, 2H), 3.34 (m, 2H), 3.60 (m, 1H), 3.93 (m, 3H), 7.50 (s, 1H), 8.0 (s, 2H), 9.58 (bs, 1H). The product was used without further purification.
Example 4
Synthesis of 1-(3,5-bis(trifluoromethyl)phenyl)-3-(piperidin-4-ylmethyl)urea (14)
[0182]
[0183] To a solution of tert-butyl 4-(aminomethyl)piperidine-1-carboxylate (11) (2.05 g, 9.57 mmol) in CH 2 Cl 2 (110 mL) at 0° C. was added slowly 1-isocyanato-3,5-bis(trifluoromethyl)benzene (12)(1.65 mL, 9.57 mmol). The reaction was stirred for 4 hours; at this time, the reaction was concentrated and purified by automated flash chromatography (R f =0.6 in 1:1 PE:EtOAc) to provide the title compound as a white solid (3.93 g, 88%). 1 H NMR (300 mHz, CDCl 3 ) δ 1.12 (m, 2H), 1.47 (s, 9H), 1.72 (m, 4H), 2.74 (t, 2H, J=12.8 Hz), 3.20 (m, 2H), 4.13 (d, 2H, J=11.7 Hz), 5.74 (br s, 1H), 7.45 (s, 1H), 7.88 (s, 2H). LRMS (ESI) calcd for C 15 H 17 F 6 N 3 O [M-Boc+2] 370.3, found 370.0, calcd for C 20 H 25 F 6 N 3 O 3 [M+Na] 492.4, found 492.0].
[0184] A solution of tert-butyl 4-((3-(3,5-bis(trifluoromethyl)phenyl)ureido)methyl)piperidine-1-carboxylate (13) (1.15 g, 2.45 mmol) in EtOAc (40 mL) was bubbled with HCl gas for 45 seconds. The solution was then concentrated after stirring at room temperature for 45 minutes to provide the product in quantitative yield as an HCl salt. LRMS (ESI) calcd for C 15 H 17 F 6 N 3 O [M+1] 370.3, found 370.0.
Example 5
Synthesis of 1-(3,5-bis(trifluoromethyl)phenyl)-3-(piperidin-4-yl)urea (17)
[0185]
[0186] To a solution of tert-butyl 4-aminopiperidine-1-carboxylate (15) (1.11 g, 5.54 mmol) in CH 2 Cl 2 (100 mL) was added slowly 1-isocyanato-3,5-bis(trifluoromethyl)benzene (12) (0.96 mL, 5.54 mmol). The reaction was stirred at room temperature overnight. The reaction was then concentrated, and the residue was purified by automated flash chromatography (R f =0.65 in 1:1 PE:EtOAc) to provide the title compound in quantitative yield as a white foam. 1 H NMR (300 mHz, CDCl 3 ) δ 1.24 (m, 2H), 1.48 (s, 9H), 1.98 (d, 2H, J=11.9 Hz), 2.91 (d, 2H, J=11.4 Hz), 3.86 (br s, 1H), 4.02 (d, 2H, J=13.6 Hz), 5.37 (br s, 1H), 7.47 (s, 1H), 7.86 (s, 2 H). LRMS (ESI) calcd for C 14 H 15 F 6 N 3 O [M-BOC+2] 356.3, found 356.0, calcd for C 29 H 23 F 6 N 3 O 3 [M+Na] 478.4, found 478.0].
[0187] A solution of tert-butyl 4-(3-(3,5-bis(trifluoromethyl)phenyl)ureido)piperidine-1-carboxylate (16) (1.29 g, 2.83 mmol) in EtOAc (40 mL) was saturated with HCl gas. The reaction was stirred at room temperature for 45 minutes, then concentrated to provide the product as an HCl salt in quantitative yield. LRMS (ESI) calcd for C 14 H 15 F 6 N 3 O [M+1] 356.3, found 356.0.
Example 6
Synthesis of 3-(tert-butoxycarbonylamino)-2,2-dimethylpropanoic acid (19)
[0188]
[0189] 3-Amino-2,2-dimethylpropanoic acid (18) (1.2 g, 10.2 mmol), Boc anhydride (2.3 g, 10.2 mmol) and DIPEA (1.85 mL, 10.23 mmol) were stirred under argon in DMF (30 mL) at 60° C. for 16 h. The reaction was concentrated in vacuo, taken up in EtOAc, washed with saturated NH 4 Cl solution, and concentrated in vacuo to give 3-(tert-butoxycarbonylamino)-2,2-dimethylpropanoic acid (19) (2.0 g, 91%); 1 H NMR (300 mHz—CDCl 3 ) δ 1.33 (s, 6H), 1.37 (s, 9H), 2.69 (s, 2H).
Example 7
Synthesis of 3-(tert-butoxycarbonylamino)-3-methylbutanoic acid (20)
[0190]
[0191] 3-(tert-butoxycarbonylamino)-3-methylbutanoic acid (20) was prepared in analogous manner to Example 5, using 3-amino-3-methylbutanoic acid hydrochloride (19).
Example 8
General Protocol for BOC Amino Acids Amide Coupling Exemplified by the Synthesis of 2-(1-((trans)-2-aminocyclohexanecarbonyl)piperidin-4-yl)-N-(3,5-bis(trifluoromethyl)phenyl)acetamide (23)
[0192]
[0193] N-(3,5-bis(trifluoromethyl)phenyl)-2-(piperidin-4-yl)acetamide (free base of Compound 4; 100 mg, 0.28 mmol), HATU (161 mg, 0.42 mmol), TEA (197 μL, 1.41 mmol) and (trans)-2-(tert-butoxycarbonylamino)cyclohexanecarboxylic acid (21) (103 mg, 0.42 mmol) were stirred in DMF (1 mL) at room temperature for 16 h. The reaction was scavenged with Si bound isocyanate and Si bound carbonate resins, and filtered. The filtrate was then concentrated in-vacuo. The residue was treated with 2M HCl in Et 2 O at room temperature for 5 h, and quenched with saturated NaHCO 3 solution. The organics were separated, dried, and concentrated in vacuo. The residue was purified by mass directed reverse phase HPLC to give 2-(1-((trans)-2-aminocyclohexane carbonyl)-piperidin-4-yl)-N-(3,5-bis(trifluoromethyl)phenyl)acetamide (23).
Example 9
Synthesis of N-(3,5-bis(trifluoromethyl)phenyl)-2-(1-(1-methylpiperidine-3-carbonyl)piperidin-4-yl)acetamide (25)
[0194]
[0195] N-(3,5-bis(trifluoromethyl)phenyl)-2-(piperidin-4-yl)acetamide (free base of Compound 4; 100 mg, 0.28 mmol), HATU (161 mg, 0.42 mmol), TEA (197 μL, 1.41 mmol) and 1-methylpiperidine-3-carboxylic acid (24) (60 mg, 0.42 mmol) were stirred in DMF (1 mL) at room temperature for 16 h. The reaction was scavenged with Si bound isocyanate and Si bound carbonate resin and filtered. The filtrate was then concentrated in-vacuo. The residue was purified by mass directed reverse phase HPLC to give N-(3,5-bis(trifluoromethyl)phenyl)-2-(1-(1-methylpiperidine-3-carbonyl)piperidin-4-yl)acetamide (25).
Example 10
Synthesis of 2-(1-(trans)-(2-aminocyclohexanecarbonyl)piperidin-4-yl)-N-(3,5-dichlorophenyl)acetamide (30)
[0196]
[0197] A general method for the synthesis of analogs of Formula A is exemplified by the synthesis of 2-(1-(trans)-(2-aminocyclohexanecarbonyl)piperidin-4-yl)-N-(3,5-dichlorophenyl)acetamide (30). The synthesis of compound (27) is described in Example 11.
Example 11
Synthesis of ethyl 2-(1-trans-(2-(tert-butoxycarbonylamino)cyclohexanecarbonyl)-piperidin-4-yl)acetate (27)
[0198]
[0199] Trans-2-(tert-butoxycarbonylamino)cyclohexanecarboxylic acid (21) (1.5 g, 6.17 mmol), ethyl 2-(piperidin-4-yl)acetate (26) (1.06 g, 6.12 mmol), HATU (3.05 g, 8.02 mmol), and DIPEA (5.37 mL, 30.85 mmol) were stirred in DCM (120 mL) at room temperature for 16 h. The reaction was concentrated in vacuo and taken up in EtOAc. The organic layer was washed sequentially with saturated NaHCO 3 solution, saturated NH 4 Cl solution, saturated NaHCO 3 solution, and brine. The organic layer was then dried and concentrated in vacuo. The residue was then purified by automated column chromatography (50% EtOAc/PE) to give ethyl 2-(1-trans-(2-(tert-butoxycarbonylamino)cyclohexanecarbonyl)-piperidin-4-yl)acetate (27) (2.82 g, 100%). 1 H NMR (300 mHz—CD 3 OD) δ 1.33 (m, 18H), 2.02 (m, 7H), 2.28 (m, 2 H), 2.59 (m, 1H), 2.80 (m, 1H), 3.09 (m, 1H), 3.65 (m, 1H), 4.13 (m, 3H), 4.54 (m, 1H), 6.45 (m, 1H).
Preparation of 2-(1-((trans)-2-(tert-butoxycarbonylamino)cyclohexanecarbonyl)piperidin-4-yl)acetic acid (28)
[0200] Ethyl 2-(1-trans-(2-(tert-butoxycarbonylamino)cyclohexanecarbonyl)-piperidin-4-yl)acetate (27) (2.82 g, 7.11 mmol) and NaOH (1.02 g, 17.3 mmol) were heated in MeOH/THF/H 2 O (20/80/20 mL) at reflux for 16 h. The reaction was concentrated in vacuo, and the residue was then taken up in H 2 O (20 mL) and acidified with 2 M HCl. The aqueous was extracted with three times with EtOAc, and the combined organics dried and concentrated in-vacuo to give 2-(1-((trans)-2-(tert-butoxycarbonylamino)cyclohexanecarbonyl)piperidin-4-yl)acetic acid (28) (2.22 g, 85%). 1 H NMR (300 mHz—CD 3 OD) δ 1.30 (m, 16H), 1.81 (m, 6H), 2.26 (d, 2H, J=7.08 Hz), 2.63 (m, 1H), 2.81 (m, 1H), 3.11 (m, 1H), 3.64 (m, 1H), 4.55 (m, 1H).
Preparation of 2-(1-(trans)-(2-aminocyclohexanecarbonyl)piperidin-4-yl)-N-(3,5-dichlorophenyl)acetamide (30)
[0201] 2-(1-((Trans)-2-(tert-butoxycarbonylamino)cyclohexanecarbonyl)piperidin-4-yl)acetic acid (28) (100 mg, 0.27 mmol), 3,5-dichloroaniline (29) (57 mg, 0.35 mmol), HATU (134 mg, 0.35 mmol) and DIPEA (236 μL, 1.36 mmol) were stirred in DMF (0.5 mL) at room temperature for 16 h. The reaction was diluted with EtOAc (2.5 mL), washed with saturated NaHCO 3 solution, and the organic layer ws then treated with HCl (g) for 12 s. The reaction was concentrated in-vacuo and the residue purified by mass directed reverse phase HPLC to give 2-(1-(trans)-(2-aminocyclohexanecarbonyl)piperidin-4-yl)-N-(3,5-dichlorophenyl)acetamide (30).
Example 12
General Procedure for the Synthesis of N-(3,5-bis(trifluoromethyl)phenyl)-2-(4-hydroxypiperidin-4-yl)acetamide hydrochloride (33)
[0202]
[0203] To a round-bottom flask containing Zn dust (878 mg, 13.47 mmol) was added dibromoethane (0.1 mL, 1.16 mmol). The resulting mixture was warmed to 60° C. and allowed to cool for 1 min. This heating-cooling process was repeated three more times, and then the flask was allowed to cool for an additional 3 min. Trimethylsilyl chloride (0.2 mL, 1.56 mmol) in THF (15 mL) was added, followed by addition of ethyl-2-bromoacetate (31) (0.5 ml, 4.49 mmol) in THF (3 mL). The reaction was warmed to 60° C. for an additional two hours until a dark grey suspension was obtained. The mixture was cooled to room temperature; N—BOC-piperidine-4-one (600 mg, 3.0 mmol) in THF (20 mL) was then added. The resulting mixture was continued to stir for 3 days then quenched with water. The solid was filtered off, and the aqueous was extracted with ethyl acetate. The combined organic layers were washed with brine and dried over Na 2 SO 4 . Purification was performed in Biotage to give the product as colorless oil (730 mg, 85%).
[0204] The material (730 mg) from the previous step was dissolved in the mixture of methanol (5 mL) and NaOH solution (10 N, 1 mL). The resulting mixture was refluxed for 3 hours and then cooled to room temperature. The solvent was evaporated, and the residue was re-dissolved in water and then extracted with diethyl ether. The aqueous solution was neutralized with conc. HCl until pH=4, and the aqueous layer was then extracted with dichloromethane. The combined dichloromethane layers were dried over NaSO 4 . Evaporation of solvent gave 32 as white solid. 1 H NMR (300 mHz; CDCl 3 ) δ 1.44 (s, 9H), 1.48 (m, 2H), 1.66 (d, 2H, J=12.99 Hz), 2.46 (s, 2H), 3.13 (t, 2H, J=11.7 Hz), 3.76 (b, 2H).
Example 13
Synthesis of N-(3,5-bis(trifluoromethyl)phenyl)-2-(4-hydroxypiperidin-4-yl)acetamide hydrochloride (33)
[0205] To a solution of 32 (665 mg, 2.56 mmol) in DMF (10 mL) were added 3, 5-bis-CF 3 -aniline (1.6 g, 7.08 mmol), di-isopropylethyl amine (1.3 mL, 7.10 mmol), and HATU (2.7 g, 7.10 mmol). The resulting mixture was stirred for 3 days at 60° C. The solvent was evaporated, and the residue was dissolved in EtOAc and washed sequentially with water and brine. The organic fraction was dried over Na 2 SO 4 , filtered, and the solvent was removed under reduced pressure. The crude material was purified by Biotage to provide the product as a white solid (540 mg, 32%).
[0206] The material obtained from above was dissolved in EtOAc, and HCl gas was bubbled into solution for 30 seconds. The resulting solution was capped and stirred for an additional 1 hour at room temperature. Evaporation of solvent gave the compound 33 as HCl salt. 1 H NMR (300 mHz; CD 3 OD) δ 2.01 (b, 4H), 2.67 (s, 2 H), 3.42 (m, 4H), 7.67 (s, 1H), 8.26 (s, 2H).
Example 14
Mass Spectrometric Analysis
[0207] Following the general procedures set forth in Examples 1-13, the following compounds listed in Table 1 below were prepared. Mass spectrometry was employed with the final compound and at various stages throughout the synthesis as a confirmation of the identity of the product obtained (M+1). For the mass spectrometric analysis, samples were prepared at an approximate concentration of 1 μg/mL in methanol:water (50:50 v/v) with 0.1% formic acid. Samples were then analyzed by a Waters 3100 Applied Biosystems API3000 single quadrupole mass spectrometer and scanned in the range of 250 to 700 m/z.
[0208] The compound numbers used in this table do not correspond to the numbering of compounds in the synthesis schemes and examples, and all references to testing of compounds refers to the compound numbers in Table 1.
[0209] Note also that, for convenience, a single enantiomer is depicted for many of the chiral compounds, to clearly illustrate that a certain diastereomer is intended. However, the compounds in Table 1 are all racemic unless the Compound Name in the Table indicates a specific chirality. Compounds for which the name designates a specific enantiomer, by use of chirality designations R and S, were obtained and evaluated in optically active form, and are generally at least about 90% optically pure.
[0000]
TABLE 1
Compounds of Formula (I)
Cmpd.
No.
Structure
Cmpd Name
MW
1
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1-(1- methylpiperidine-3- carbonyl)piperidin-4- yl)acetamide
479.46
2
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1- (piperidine-3- carbonyl)piperidin-4- yl)acetamide
465.43
3
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
479.46
4
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1- (morpholine-2- carbonyl)piperidin-4- yl)acetamide
467.41
5
cis-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
479.46
6
2-(1-((1R,2R)-2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
479.46
7
2-(1-((1S,2S)-2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
479.46
8
2-(1-(2-(1- aminocyclohexyl) acetyl)piperidin-4-yl)-N- (3,5- bis(trifluoromethyl) phenyl)acetamide
493.49
9
2-(1-(1- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
479.46
10
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3,5- difluorophenyl)acetamide
379.44
11
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(4- fluorophenyl)acetamide
361.45
12
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3-chloro-4- fluorophenyl)acetamide
395.90
13
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3- (trifluoromethyl) phenyl)acetamide
411.46
14
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(2,4,5- trifluorophenyl)acetamide
397.43
15
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(4-chloro-2- (trifluoromethyl) phenyl)acetamide
445.91
16
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(4-fluoro-2- (trifluoromethyl) phenyl)acetamide
429.45
17
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3,5- dichlorophenyl)acetamide
412.35
18
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(4- (trifluoromethoxy) phenyl)acetamide
427.46
19
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3-bromo-5- (trifluoromethyl) phenyl)acetamide
490.36
20
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(4-bromo-3- (trifluoromethyl) phenyl)acetamide
490.36
21
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(4- (trifluoromethylsulfonyl) phenyl)acetamide
475.52
22
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(2-fluoro-4- (methylsulfonyl) phenyl)acetamide
439.54
23
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(5- (trifluoromethyl) pyridin-2-yl)acetamide
412.45
24
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(6- (trifluoromethyl) pyridin-2-yl)acetamide
412.45
25
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(3- (trifluoromethyl) pyridin-2-yl)acetamide
412.45
26
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(4- (trifluoromethyl) pyridin-2-yl)acetamide
412.45
27
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(6- (trifluoromethyl) pyridin-3-yl)acetamide
412.45
28
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-N-(5- (trifluoromethyl)- 1,3,4-oxadiazol-2- yl)acetamide
403.40
29
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1- (piperidine-2- carbonyl)pyrrolidin-3- yl)acetamide
451.41
30
2-(1-((1R,2S)-2- aminocyclohexanecarbonyl) pyrrolidin-3- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
465.43
31
2-(1-((1S,2R)-2- aminocyclohexanecarbonyl) pyrrolidin-3- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
465.43
32
2-(1-((1R,2R)-2- aminocyclohexanecarbonyl) pyrrolidin-3- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
465.43
33
2-(1-((1S,2S)-2- aminocyclohexanecarbonyl) pyrrolidin-3- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
465.43
34
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1-(2- methylpiperidine-2- carbonyl)pyrrolidin-3- yl)acetamide
465.43
35
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1-(1- methylpiperidine-2- carbonyl)pyrrolidin-3- yl)acetamide
465.43
36
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1-(1- methylpiperidine-3- carbonyl)pyrrolidin-3- yl)acetamide
465.43
37
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1-(1- methylpiperidine-2- carbonyl)azetidin-3- yl)acetamide
451.41
38
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1-(1- methylpiperidine-3- carbonyl)azetidin-3- yl)acetamide
451.41
39
N-(3,5- bis(trifluoromethyl) phenyl)-2-(1- (piperidine-2- carbonyl)azetidin-3- yl)acetamide
437.38
40
trans-2-(1-(2- aminocyclohexanecarbonyl) azetidin-3-yl)- N-(3,5- bis(trifluoromethyl) phenyl)acetamide
451.41
41
cis-2-(1-(2- aminocyclohexanecarbonyl) azetidin-3-yl)- N-(3,5- bis(trifluoromethyl) phenyl)acetamide
451.41
42
2-(1-(3-amino-3- methylbutanoyl) piperidin-4-yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
453.42
43
2-(1-(3-amino-3- methylbutanoyl) azetidin-3-yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
425.37
44
2-(1-(3-amino-3- methylbutanoyl) pyrrolidin-3-yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
439.40
45
2-(1-(3-amino-2,2- dimethylpropanoyl) piperidin-4-yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
453.42
46
2-(1-(3-amino-2,2- dimethylpropanoyl) azetidin-3-yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
425.37
47
2-(1-(3-amino-2,2- dimethylpropanoyl) pyrrolidin-3-yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
439.40
48
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)methyl)-3,5- bis(trifluoromethyl) benzamide
479.46
49
cis-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)methyl)-3,5- bis(trifluoromethyl) benzamide
479.46
50
(S)-N-(3,5- bis(trifluoromethyl) phenyl)-2-(4-hydroxy-1- (piperidine-2- carbonyl)piperidin-4- yl)acetamide
481.432
51
trans-2-(1-(2- aminocyclohexanecarbonyl)- 4- hydroxypiperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
495.458
52
cis-2-(1-(2- aminocyclohexanecarbonyl)- 4- hydroxypiperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
495.458
53
(R)-N-(3,5- bis(trifluoromethyl) phenyl)-2-(4-hydroxy-1- (piperidine-2- carbonyl)piperidin-4- yl)acetamide
481.432
54
2-(1-(2-(1- aminocyclohexyl) acetyl)-4- hydroxypiperidin-4- yl)-N-(3,5- bis(trifluoromethyl) phenyl)acetamide
509.485
55
(S)-1-(3,5- bis(trifluoromethyl) phenyl)-3-((1- (piperidine-2- carbonyl)piperidin-4- yl)methyl)urea
480.447
56
(R)-1-(3,5- bis(trifluoromethyl) phenyl)-3-((1- (piperidine-2- carbonyl)piperidin-4- yl)methyl)urea
480.447
57
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)methyl)-3-(3,5- bis(trifluoromethyl) phenyl)urea
494.474
58
cis-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)methyl)-3-(3,5- bis(trifluoromethyl) phenyl)urea
494.474
59
1-((1-(2-(1- aminocyclohexyl) acetyl)piperidin-4- yl)methyl)-3-(3,5- bis(trifluoromethyl) phenyl)urea
508.5
60
(S)-1-(3,5- bis(trifluoromethyl) phenyl)-3-(1- (piperidine-2- carbonyl)piperidin-4- yl)urea
466.421
61
(R)-1-(3,5- bis(trifluoromethyl) phenyl)-3-(1- (piperidine-2- carbonyl)piperidin-4- yl)urea
466.421
62
trans-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-3-(3,5- bis(trifiuoromethyl) phenyl)urea
480.447
63
cis-2-(1-(2- aminocyclohexanecarbonyl) piperidin-4- yl)-3-(3,5- bis(trifluoromethyl) phenyl)urea
480.447
64
1-(1-(2-(1- aminocyclohexyl) acetyl)piperidin-4-yl)-3- (3,5- bis(trifluoromethyl) phenyl)urea
494.474
65
66
67
68
69
70
71
72
73
74
75
Example 15
T-Type Channel Blocking Activities
[0210] A. Transformation of HEK Cells:
[0211] T-type calcium channel blocking activity was assayed in human embryonic kidney cells, HEK 293 (Invitrogen), stably transfected with the T-type calcium channel subunits. Briefly, cells were cultured in Dulbecco's modified eagle medium (DMEM) supplemented with 10% fetal bovine serum, 200 U/ml penicillin, and 0.2 mg/mL streptomycin at 37° C. with 5% CO 2 . At 85% confluency, cells were split with 0.25% trypsin/1 mM EDTA and plated at 10% confluency on glass coverslips. At 12 hours, the medium was replaced, and the cells stably transfected using a standard calcium phosphate protocol and the appropriate calcium channel cDNA's. Fresh DMEM was supplied, and the cells transferred to 28° C./5% CO 2 . Cells were incubated for 1 to 2 days prior to whole cell recording.
[0212] Standard patch-clamp techniques were employed to identify blockers of T-type currents. Briefly, previously described HEK cell lines stably expressing human α 1G , α 1H and α 1I T-type channels were used for all the recordings (passage #: 4-20, 37° C., 5% CO 2 ). Whole cell patch clamp experiments were performed using an Axopatch 200B amplifier (Axon Instruments, Burlingame, Calif.) linked to a personal computer equipped with pCLAMP software. Data were analyzed using Clampfit (Axon Instruments) and SigmaPlot 4.0 (Jandel Scientific). To obtain T-type currents, plastic dishes containing semi-confluent cells were positioned on the stage of a ZEISS AXIOVERT S100 microscope after replacing the culture medium with external solution (Table 2). Whole-cell patches were obtained using pipettes (borosilicate glass with filament, O.D.: 1.5 mm, I.D.: 0.86 mm, 10 cm length), fabricated on a SUTTER P-97 puller with resistance values of ˜5 MΩ (Table 3).
[0000]
TABLE 2
External Solution 500 ml - pH 7.4, 265.5 mOsm
Salt
Final mM
Stock M
Final ml
CsCl
142
1
71
CaCl 2
2
1
1
MgCl 2
1
1
0.5
HEPES
10
0.5
10
glucose
10
—
0.9 grams
[0000]
TABLE 3
Internal Solution 50 ml - pH 7.3 with CsOH, 270 mOsm
Salt
Final mM
Stock M
Final ml
Cs-Methanesulfonate
126.5
—
1.442 gr/50 ml
MgCl2
2
1
0.1
HEPES
10
0.5
1
EGTA-Cs
11
0.25
2.2
ATP
2
0.2
0.025
(1 aliquot/2.5 ml)
[0213] T-type currents were reliably obtained by using two voltage protocols:
[0214] “non-inactivating,” and
[0215] “inactivation.”
[0216] In the non-inactivating protocol, the holding potential is set at −110 mV and with a pre-pulse at −100 mV for 1 second prior to the test pulse at −40 mV for 50 ms. In the inactivation protocol, the pre-pulse is at approximately −85 mV for 1 second, which inactivates about 15% of the T-type channels (Scheme 1).
[0000] Test compounds were dissolved in external solution, 0.1-0.01% DMSO. After ˜10 minutes rest, they were applied by gravity close to the cell using a WPI microfil tubing. The “non-inactivated” pre-pulse was used to examine the resting block of a compound. The “inactivated” protocol was employed to study voltage-dependent block. However, the initial data shown below were mainly obtained using the non-inactivated protocol only. IC 50 values are shown for various compounds of the invention in Table 4. Values are shown in nM, with values above 10,000 nM represented as “10000 nM.” The data show that each of compounds 1-3, 5-9, 17, 19, 20, 29-33, 40-42, 45, 50-52, 54 and 56-64 exhibited activity at less than 1 μM. Further, compounds 3, 54, and 59 exhibited activity at less than 0.01 μM, with compound 59 demonstrating the lowest IC 50 . In Table 4, empty cells indicate that inhibition by the compound was not detected.
[0000]
TABLE 4
T-type Calcium Channel Block
α 1G (Ca V 3.1)
α 1H (Ca V 3.2)
Compound
nM
nM
1
10000
510
2
350
3
10000
60
4
10000
2180
5
10000
100
6
10000
250
7
10000
140
8
10000
110
9
4680
990
10
11
10000
12
13
10000
2670
14
10000
15
16
17
10000
690
18
2730
19
10000
280
20
10000
920
21
22
23
24
25
26
27
28
29
7020
570
30
8950
710
31
6190
460
32
5660
630
33
5290
260
34
4400
1940
35
6020
1950
36
8100
2440
37
10000
4390
38
10000
8040
39
10000
1210
40
10000
830
41
10000
850
42
10000
570
43
10000
10000
44
10000
2100
45
10000
540
46
10000
10000
47
10000
3370
48
10000
1850
49
1930
50
520
51
490
52
820
53
1860
54
80
55
1110
56
770
57
250
58
250
59
30
60
950
61
690
62
270
63
430
64
360
Example 16
L5/L6 Spinal Nerve Ligation (SNL)—Chung Pain Model
[0217] The Spinal Nerve Ligation is an animal model representing peripheral nerve injury generating a neuropathic pain syndrome. In this model experimental animals develop the clinical symptoms of tactile allodynia and hyperalgesia. L5/L6 Spinal nerve ligation (SNL) injury was induced using the procedure of Kim and Chung (Kim et al., Pain 50:355-363 (1992)) in male Sprague-Dawley rats (Harlan; Indianapolis, Ind.) weighing 200 to 250 grams.
[0218] Anaesthesia was induced with 2% isofluorane in O 2 at 2 L/min and maintained with 0.5% isofluorane in O 2 . Rats were then shaved and aseptically prepared for surgeries. A 2 cm paraspinal incision was made at the level of L4-S2. L4/L5 was exposed by removing the transverse process above the nerves with a small rongeur. The L5 spinal nerve is the larger of the two visible nerves below the transverse process and lies closest to the spine. The L6 spinal nerve is located beneath the corner of the slope bone. A home-made glass Chung rod was used to hook L5 or L6 and a pre-made slip knot of 4.0 silk suture was placed on the tip of the rod just above the nerve and pulled underneath to allow for the tight ligation. The L5 and L6 spinal nerves were tightly ligated distal to the dorsal root ganglion. The incision was closed, and the animals were allowed to recover for 5 days. Rats that exhibited motor deficiency (such as paw-dragging) or failure to exhibit subsequent tactile allodynia were excluded from further testing.
[0219] Sham control rats underwent the same operation and handling as the experimental animals, but without SNL.
[0220] Prior to initiating drug delivery, baseline behavioural testing data is obtained. At selected times after infusion of the Test or Control Article behavioural data can then be collected again.
A. Assessment of Tactile Allodynia—Von Frey
[0221] The assessment of tactile allodynia consisted of measuring the withdrawal threshold of the paw ipsilateral to the site of nerve injury in response to probing with a series of calibrated von Frey filaments (innocuous stimuli). Animals were acclimated to the suspended wire-mesh cages for 30 min before testing. Each von Frey filament was applied perpendicularly to the plantar surface of the ligated paw of rats for 5 sec. A positive response was indicated by a sharp withdrawal of the paw. For rats, the first testing filament is 4.31. Measurements were taken before and after administration of test articles. The paw withdrawal threshold was determined by the non-parametric method of Dixon (Dixon, Ann. Rev. Pharmacol. Toxicol. 20:441-462 (1980)), in which the stimulus was incrementally increased until a positive response was obtained, and then decreased until a negative result was observed. The protocol was repeated until three changes in behaviour were determined (“up and down” method) (Chaplan et al., J. Neurosci. Methods 53:55-63 (1994)). The 50% paw withdrawal threshold was determined as (10 [Xf+kδ] )/10,000, where X f =the value of the last von Frey filament employed, k=Dixon value for the positive/negative pattern, and δ=the logarithmic difference between stimuli. The cut-off values for rats were no less than 0.2 g and no higher than 15 g (5.18 filament); for mice no less than 0.03 g and no higher than 2.34 g (4.56 filament). A significant drop of the paw withdrawal threshold compared to the pre-treatment baseline is considered tactile allodynia. Table 5 shows exemplary rat SNL data obtained for Compounds 2, 54, and 75.
[0000] TABLE 5 Rat SNL tactile allodynia (% antiallodynia) No. Structure 1 hr 2 hr 4 hr 2 38 44 27 54 41 39 45 75 5 3 3
Compound No. 3 from Table 1 was also tested in rats using this allodynia model, with the results as shown in Table 6. In these studies, gabapentin was dosed at 100 mg/kg orally in water. When compared to gabapentin as a control, Compound 3, at a dosage of 30 mg/kg, showed slightly lower efficacy at the 2 hr time point than gabapentin at a dosage of 100 mg/kg.
[0000]
TABLE 6
% Antiallodynia (Mean ± SD) (n = 7-8)
Gabapentin
Compound 3
Vehicle
Time
(100 mg/kg PO)
(30 mg/kg, PO)
(DMSO/PEG)
1 h
73 ± 35 #*
36 ± 19 #*
1 ± 11
2 h
90 ± 18 #*
75 ± 26 #*
1 ± 1
4 h
15 ± 8
4 ± 8
0 ± 0
# - p < 0.05 compared to pre-dose baseline
* p < 0.05 compared to vehicle alone at same time point
[0222] In a second repetition of this study at a later date than the one reported above, gabapentin performed similarly and compound 3 produced anti-allodynia effects of 68±12% at 1 hr, 76±6% at 2 hr, and 42±14% at 4 hr (n=9).
B. Assessment of Thermal Hypersensitivity—Hargreaves
[0223] The method of Hargreaves and colleagues (Hargreaves et al., Pain 32:77-8 (1988)) can be employed to assess paw-withdrawal latency to a noxious thermal stimulus.
[0224] Rats may be allowed to acclimate within a Plexiglas enclosure on a clear glass plate for 30 minutes. A radiant heat source (e.g., halogen bulb coupled to an infrared filter) can then be activated with a timer and focused onto the plantar surface of the affected paw of treated rats. Paw-withdrawal latency can be determined by a photocell that halts both lamp and timer when the paw is withdrawn. The latency to withdrawal of the paw from the radiant heat source can be determined prior to L5/L6 SNL, 7-14 days after L5/L6 SNL but before drug, as well as after drug administration. A maximal cut-off of 33 seconds is typically employed to prevent tissue damage. Paw withdrawal latency can be thus determined to the nearest 0.1 second. A significant drop of the paw withdrawal latency from the baseline indicates the status of thermal hyperalgesia. Antinociception is indicated by a reversal of thermal hyperalgesia to the pre-treatment baseline or a significant (p<0.05) increase in paw withdrawal latency above this baseline. Data is converted to % anti hyperalgesia or % anti nociception by the formula: (100×(test latency−baseline latency)/(cut-off−baseline latency) where cut-off is 21 seconds for determining anti hyperalgesia and 40 seconds for determining anti nociception.
Example 17
6 Hz Psychomotor Seizure Model of Partial Epilepsy
[0225] Compounds can also be evaluated for the protection against seizures induced by a 6 Hz, 0.2 ms rectangular pulse width of 3 s duration, at a stimulus intensity of 32 mA (CC97) applied to the cornea of male CF1 mice (20-30 g) according to procedures described by Barton et al, “Pharmacological Characterization of the 6 Hz Psychomotor Seizure Model of Partial Epilepsy,” Epilepsy Res. 47(3):217-27 (2001). Seizures are characterised by the expression of one or more of the following behaviours: stun, forelimb clonus, twitching of the vibrissae and Straub-tail immediately following electrical stimulation. Animals can be considered “protected” if following pre-treatment with a compound the 6 Hz stimulus failed to evoke a behavioural response as describe above. Exemplary data are shown in Table 7 below.
[0000]
TABLE 7
Epilepsy 6 Hz
(% Protected)
Cmpd
0.25
0.5
1
2
4
no.
Structure
hr
hr
hr
hr
hr
2
50
50
100
33
0
3
100
75
100
0
50
8
75
75
67
100
54
25
75
75
75
100
59
25
50
100
68
50
75
100
50
0
69
75
75
50
100
33
70
0
75
100
73
100
100
100
100
Example 18
Mouse Rotarod Assay
[0226] To assess a compound's undesirable side effects (toxicity), animals can be monitored for overt signs of impaired neurological or muscular function. In mice, the rotarod procedure (Dunham and Miya, J. Am. Pharmacol. Assoc. 46:208-209 (1957)) is used to disclose minimal muscular or neurological impairment (MMI). When a mouse is placed on a rod that rotates at a speed of 6 rpm, the animal can maintain its equilibrium for long periods of time. The animal is considered toxic if it falls off this rotating rod three times during a 1-min period. In addition to MMI, animals may exhibit a circular or zigzag gait, abnormal body posture and spread of the legs, tremors, hyperactivity, lack of exploratory behavior, somnolence, stupor, catalepsy, loss of placing response and changes in muscle tone. Exemplary data are shown in Table 8 below.
[0000]
TABLE 8
Rotarod Assay
(% impaired)
Cmpd
0.25
0.5
1
2
4
No.
Structure
hr
hr
hr
hr
hr
2
25
50
100
100
50
3
0
75
100
75
50
8
0
50
75
100
100
4
25
0
75
75
75
59
0
25
75
100
100
69
0
50
50
100
100
70
0
0
100
100
100
73
100
100
100
100
75
Example 19
Lamina Assay and Data
Recordings on Lamina I/II Spinal Cord Neurons.
[0227] Male Wistar rats (P6 to P9 for voltage-clamp and P15 to P18 for current-clamp recordings) were anaesthetized through intraperitoneal injection of Inactin (Sigma). The spinal cord was then rapidly dissected out and placed in an ice-cold solution protective sucrose solution containing (in mM): 50 sucrose, 92 NaCl, 15 D-Glucose, 26 NaHCO 3 , 5 KCl, 1.25 NaH 2 PO 4 , 0.5 CaCl 2 , 7 MgSO 4 , 1 kynurenic acid, and bubbled with 5% CO 2 /95% O 2 . The meninges, dura, and dorsal and ventral roots were then removed from the lumbar region of the spinal cord under a dissecting microscope. The “cleaned” lumbar region of the spinal cord was glued to the vibratome stage and immediately immersed in ice cold, bubbled, sucrose solution. For current-clamp recordings, 300 to 350 μm parasagittal slices were cut to preserve the dendritic arbour of lamina I neurons, while 350 to 400 μm transverse slices were prepared for voltage-clamped Nay channel recordings. Slices were allowed to recover for 1 hour at 35° C. in Ringer solution containing (in mM): 125 NaCl, 20 D-Glucose, 26 NaHCO 3 , 3 KCl, 1.25 NaH 2 PO 4 , 2 CaCl 2 , 1 MgCl 2 , 1 kynurenic acid, 0.1 picrotoxin, bubbled with 5% CO 2 /95% O 2 . The slice recovery chamber was then returned to room temperature (20 to 22° C.) and all recordings were performed at this temperature.
[0228] Neurons were visualized using IR-DIC optics (Zeiss Axioskop 2 FS plus, Gottingen, Germany), and neurons from lamina I and the outer layer of lamina II were selected based on their location relative to the substantia gelatinosa layer. Neurons were patch-clamped using borosilicate glass patch pipettes with resistances of 3 to 6 ma Current-clamp recordings of lamina I/II neurons in the intact slice, the external recording solution was the above Ringer solution, while the internal patch pipette solution contained (in mM): 140 KGluconate, 4 NaCl, 10 HEPES, 1 EGTA, 0.5 MgCl 2 , 4 MgATP, 0.5 Na 2 GTP, adjusted to pH 7.2 with 5 M KOH and to 290 mOsm with D-Mannitol (if necessary). Only tonic firing neurons were selected for current-clamp experiments, while phasic, delayed onset and single spike neurons were discarded (22). Recordings were digitized at 50 kHz and low-pass filtered at 2.4 kHz.
[0229] Data obtained according to this protocol are shown in Table 9.
[0000]
TABLE 9
LAMINA I AND II
Cmpd.
% Spike Change
no.
Structure
Mean
SEM
P < 0.05?
EC 50
2
−57.2
6.3
no
6550
3
−51.1
13.2
yes
74
−53
11.8
yes
Other Embodiments
[0230] While the invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modifications and this application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure come within known or customary practice within the art to which the invention pertains and may be applied to the essential features hereinbefore set forth.
[0231] All publications, patents and patent applications are herein incorporated by reference in their entirety to the same extent as if each individual publication, patent or patent application was specifically and individually indicated to be incorporated by reference in its entirety. | Methods and compounds effective in ameliorating conditions characterized by unwanted calcium channel activity, particularly unwanted T-type calcium channel activity are disclosed using a series of compounds containing N-acylated cyclic amines linked to an aπl ring as shown in formula (I). | 2 |
BACKGROUND OF THE INVENTION
Many cartons, particularly those associated with take-out foods, are formed of relatively thin material wherein the lid is of a substantial unsupported expanse and tends to sag and contact the contents of the box to the detriment of the contents.
A well known example of such a carton, and the problems caused by a tendency of the lid to centrally sag, is the conventional pizza box. Similar problems will also be noted in folded paperboard containers for cakes, pies and the like, particularly when the containers are stacked.
In order to avoid or minimize this problem, various forms of internal supports have been devised, including plastic spacers which are relatively expensive for a throwaway item. Another solution provides for a tear-away section of the carton which is subsequently formed into a spacer for insertion within the carton, a rather complex and time consuming procedure which could in fact damage the carton if not properly done. An additional proposal involves the use of tabs folded from the carton itself. This, particularly if folded from the top or bottom of the carton, could further weaken the carton at the critical area, as well as provide undesirable openings into the interior of the carton. Other solutions involve the use of various forms of preform supports which are not only bulky, causing shipping and storage expenses, but also must, at some point, be inserted in the individual cartons or boxes.
SUMMARY OF THE INVENTION
The present invention is an internal support for pizza cartons and the like, and is constructed of inexpensive and readily folded shape sustaining material. The support, mounted preferably to the undersurface of the carton or box lid, lies flat thereagainst prior to use to avoid interfering with either the stored stacking of formed cartons or the stacking of the carton blanks prior to folding. The support also lends itself to mounting to the carton at substantially any stage from the initial formation of the carton to just prior to a closing of the carton with the contents therein.
From its stored position, the support is easily erected and automatically maintains itself in a support position.
The internal support is formed from a blank or unitary piece of foldable paperboard or the like which has sufficient rigidity as to be capable of maintaining the erected configuration of the support formed therefrom.
The blank, or unitary piece, is folded to define a central member formed of two substantially equal, adhesively secured panels. Each of the central member panels at an end thereof common with a similar end on the other central member panel, mounts, through an integral fold line, a side member or panel. A glue flap or mounting flange is integrally formed with an inner or lower edge of one of the central member panels with a fold line defined therebetween. The glue flap is affixed to the inner surface of the carton lid with the central member and the side members parallel thereto and lying flat against the inner surface.
When the support is to be erected, the central member and the attached side panels are folded to project laterally from the mounted glue flap, after which the side members are swung outwardly from each other to a position engaging or substantially engaging the opposed panels of the central member. At this point, two small locking lugs, along the side panel fold lines, respectively resiliently flex with one bypassing the other to extend beyond the two fold lines where engagement of the lugs with each other limit the return movement of the side panels to acute angles with the respective sides of the central member, thus providing a spread three member support.
The exposed outer edges of the central and side members, remote from the glue flap, are centrally recessed to, upon engagement with the foodstuff itself if such is the case, provide adequate support with minimal damaging contact. Similarly, in order to facilitate opening of the side members or panels relative to each other, a portion of one side panel projects beyond the other side panel for easy manual access thereto.
With the side members in the support position, it will be appreciated that the central member cannot, without manual manipulation, be folded flat. However, should it become desirable to collapse the support, the side members can be manually moved from their locked position with the locking lugs flexibly bypassing each other and allowing return of the panels to their parallel adjacent position which in turn will allow a downward lateral folding of the central member to substantially parallel the mounted flange or glue flap.
Other features and advantages of the invention will become apparent from the more detailed description of the invention following hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a portion of an open pizza box with the internal support of the invention mounted to the undersurface of the cover;
FIG. 2 is a plan view of the blank from which the support is formed;
FIG. 3 illustrates the initial step in erecting the support;
FIG. 4 illustrates the final manual step in erecting the support;
FIG. 5 illustrates the support in its automatically assumed final position;
FIG. 6 is an enlarged perspective view of the support rotated approximately 90 degrees from the position of FIG. 5 and illustrating the apex ends of the diverging side members; and
FIG. 7 is an enlarged cross-sectional view taken substantially on a plane passing along line 7-7 in FIG. 6.
DESCRIPTION OF PREFERRED EMBODIMENT
Referring now more specifically to the drawings, the support 10 of the invention is intended to mount between a base 12 and an overlying cover or covering member 14 to define a lateral support therebetween. While not limited thereto, its most common anticipated use will be within a pizza box or carton 16. In such case the support will mount, usually centrally, to the undersurface of the cover or top 14 and, upon a closing of the cover over the base 12, bear in a non-damaging manner on the pizza itself. The rather large area of the flexible cover 14 will thus be maintained out of contact with the upper face of the pizza, even should several filled boxes be stacked. Depending on the carton contents, the support can extend upward from the base.
The support 10 is formed from a foldable blank 18 of paperboard of sufficient rigidity to maintain itself in the erected position to be described subsequently. While other materials may be used, the substantial advantages of paperboard or cardboard with regard to availability, ease of handling, low cost, and the like, make it the preferred material.
The blank 18 includes two equal or substantially equal size rectangular main panels 20 and 22 integrally joined along common edges thereof by a fold line 24. A circular opening 26 is formed centrally along the fold line 24 and extends equally into each of the panels 20 and 22.
A pair of side members or panels 28 and 30 are of generally equal size to the panels 20 and 22 and integrally joined thereto along one end thereof, panel 28 adjacent panel 20 with fold line 32 defined therebetween, and panel 30 adjacent panel 22 with fold line 34 defined therebetween. A cut line 36, which comprises a longitudinal extension of the fold line 24, divides the panels 28 and 34 for independent movement. The cut line has an opening 38 centrally thereof which duplicates the opening 26 and similarly extends equally into the opposed panels 28 and 30.
Each of the fold lines 32 and 34, for a central elongate portion thereof, is defined by a cut line 40 which extends or is laterally offset into the respective panels 20 and 22 in order to define a pair of elongate relatively narrow lugs 42, one coplanar with each of the panels 28 and 30 and foldable therewith about the respective fold line which extends to each side of this central lug 42.
The outer end 44 of the panel 28, opposed to the fold line 32 and generally parallel thereto, includes an elongate outwardly directed convex portion. The corresponding outer end 46 of the panel 30 includes an elongate equally dimensioned outwardly directed concave portion. These outer ends 44 and 46 are differently configured to allow easy access thereto in the formed support ]0 as shall be explained. The corresponding nature of the convex and concave portions is desired to facilitate the formation of adjacent duplicate blanks, one inverted relative to the other, with minimal waste.
A mounting flange or glue flap 48 is integral with the outer edge of panel 20 opposed from and parallel to the central fold line 24, with a fold line 50 defined between flap 48 and panel 20. The flap 48 is preferably of equal length with the side edge of the panel 20 and of a substantially shorter width outward therefrom.
In forming the support 10, the panels 22 and 30 are folded to overlie the respective panels 20 and 28, either thereabove or therebelow, about the fold line 24 and linearly aligned cutline 36. The overlying panels 20 and 22 are secured along a substantial portion of the edges thereof remote from the fold line 24 by appropriate means such as the adhesive strip 52 suggested in FIG. 2.
Upon a positioning of the folded support 10 on, as suggested in FIG. 1, the undersurface of a carton lid, the mounting flange 48 is fixed to the lid, preferably by an appropriate adhesive or the like 54. The support 10 may be retained in the flat position thereof as in FIG. 1 until such time as the contents of the box or carton are introduced and the cover is to be closed thereon. This flat positioning facilitates a nested stacking of multiple open boxes, or a stacking of box blanks prior to a folding thereof, for ease in handling, shipping and storage.
When the mounted support 10 is to be erected, the overlying panels 20 and 22 are pivoted upward or laterally about the fold line 50 to define a central member 56 comprised of the two panels 20 and 22. The overlying panels 28 and 30 similarly pivot laterally therewith and are positioned to define side panels or members in the completely erected support. This first step is noted in FIG. 3. Turning now to FIG. 4, the next step involves an outward swinging of the side panels 28 and 30, about the respective fold lines 32 and 34, relative to each other and to respectively overlie the central member panels 20 and 22.
At this step, the side panels 28 and 30 are preferably pivoted substantially a full 180 degrees to engage against the central member panels 20 and 22, the purpose of this being to allow for a movement of the now-aligned lugs 42 past each other so as to project beyond the ends of the central member 56 and side members or panels 28 and 30 defined by the fold lines 32 and 34. In this intermediate position, the lugs 42 are in immediate adjacent parallel relation to each other. Incidentally, it should be appreciated that the outward swinging of the side panels 28 and 30 relative to each other is facilitated by the easily grasped ends thereof which correspond to the blank edges 44 and 46.
The lugs 42, upon an outward swinging of the panels 28 and 30, snap into the position of FIG. 4 due to the inherent resilient flexibility of the material thereof with, if necessary, a slight flexing in the adjoining ends of the central member panels 20 and 22 along the fold lines 32 and 34.
Noting FIGS. 5, 6 and 7, upon a release of the folded panels 28 and 30, in the intermediate position of FIG. 4, these side panels, due to the inherent memory characteristics of the material, outwardly swing toward their original planar position as in FIG. 3. However, the now reversely turned lugs 42 effectively abut each other and prevent a movement of the side panels 28 and 30 beyond an acute angle with respect to the central member, thus stabilizing the support in its erected or support position and providing three diverging support members extending from a vertex end. In this manner a relatively wide support area is provided in conjunction with a wide base area to prevent lateral tipping or folding of the support once erected,. It should be appreciated from FIG. 7 in particular, that while the lugs 42 can be manually reinverted to the position of FIG. 3, this will not occur automatically or without positive external force, thus ensuring a rigid spread support notwithstanding the rather thin nature of the paperboard from which the support is constructed.
It will be noted that the previously described circular openings 26 and 38 in the blank 18, upon a folding about the fold line 24 and cut line 36, define central recessed areas in the upper or outer edges of the central member 56 and side members 28 and 30, thereby reducing the area of contact with foodstuffs or the like as may be in the carton without affecting the stability of the support.
The foregoing described embodiment is illustrative of the principals of the invention. As other embodiments incorporating the inventive features may occur to those skilled in the art, the disclosed embodiment is not to be considered as a limitation on the scope of the invention. Rather, the invention is only to be limited by the scope of the claims following hereinafter. | A carton support formed from a folded unitary blank of paperboard and including a central member with a pair of separate side members mounted to the same end of said central member and outwardly pivoted to generally overlie the opposite sides of the central member and extend at acute angles to the respective sides thereof. A pair of lugs, one on each side member, snap-lock into position to retain the side members in their erected positions at acute angles to the central member. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to light bulb assemblies for vehicles. More specifically, the invention is a flush fitting turn signal for motorcycles using light emitting diode (LED) lamps.
2. Description of the Related Art
Light bulb assemblies for motorcycles or sportbikes typically are an assembly having an incandescent light bulb mounted in a reflector housing with a tinted lens or light-transmissive cover.
Today's sportbikes purchased directly from the dealer are equipped with very large turn signals that protrude out from the sides of the front fairing. While functional, these lights often take away from the overall streamlined appearance of the motorcycle. Many owners remove these stock lights soon after purchasing the vehicle and have found alternative locations for more esthetically pleasing and functional front turn signals. One alternative has been handlebar-mounted lamps, utilizing either incandescent or light emitting diodes (LEDs), as described by U.S. Pat. Nos. 4,361,829, 5,247,431, and 6,081,190. Generally, the LED implemented turn signals are more effective in resisting damage due to vibration generated during normal and off-road use.
The unique structural and environmental conditions experienced by motorcycles have resulted in a variety of lighting devices specifically developed for motorcycles, which have generally require additional support structures and do not maintain the streamline appearance of the motorcycle. Examples of these lighting devices include U.S. Pat. Nos. 3,950,727, 4,949,228, 5,418,696, 5,617,303, 5,689,232, 6,461,017, and 6,464,379.
While motorcycle enthusiasts are sensitive to the issue of streamlined appearance, they are not willing to forgo practicality and safety, and therefore having a turn signal viewable from all positions is desired. Thus a flush fitting LED turn signal, which can be viewed from all positions, is desired.
None of the above inventions and patents, taken either singly or in combination, is seen to describe the instant invention as claimed.
SUMMARY OF THE INVENTION
The flush fitting front LED turn signal has a flush mounted aluminum housing and an LED assembly with a domed lens extending beyond the upper surface of the housing. The housing, attached from behind the fairing, presents an outer surface flush with the front fairing of a motorcycle. Mounted within the housing is a multi-chip high-intensity, sunlight visible LED assembly, the dome of which protrudes beyond the surface of the housing and is visible from all angles. Mounted from within the fairing without any modification to the vehicle, the present invention presents a nearly seamless transition to the vehicle's bodywork, while providing the ruggedness and longevity of LED technology. The combination of housing and LED assembly may be provided in a variety of colors to match the factory finish.
Accordingly, it is a principal object of the invention to provide a flush fitting front LED turn signal for motorcycles and sportbikes.
It is another object of the invention to provide a turn signal for a motorcycle which is more rugged than the standard external mounted incandescent lamps supplied as original equipment on motorcycles through a flush mounted turn signal utilizing an LED assembly.
It is a further object of the invention to provide flush fitting front LED turn signals for a motorcycle in order to reduce the risk of damage if the motorcycle is laid on its side.
It is another object of the invention to provide a turn signal for motorcycles, which is visible from all viewing perspectives for safety purposes, and which is also mounted flush within the motorcycle fairing for producing an aesthetically pleasing, streamlined appearance.
It is an object of the invention to provide improved elements and arrangements thereof for the purposes described which is inexpensive, dependable and fully effective in accomplishing its intended purposes.
These and other objects of the present invention will become readily apparent upon further review of the following specification and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an environmental, perspective view of a motorcycle with a flush fitting front LED turn signal according to the present invention.
FIG. 2 is an environmental, perspective view of a protruding front turn signal according to the prior art.
FIG. 3 is a side view of a flush fitting LED turn signal according to the present invention.
FIG. 4 is an exploded, perspective view of a flush fitting LED turn signal according to the present invention.
FIG. 5 is a representative schematic of the electronic components of a flush fitting LED turn signal according to the present invention.
FIG. 6 is a bottom, perspective view of a flush fitting LED turn signal according to the present invention.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1 , the present invention is a flush fitting front turn signal 100 mounted within the front fairing 104 of a motorcycle 102 that replaces the original equipment, large protruding stock turn signals 202 that extend from the sides of a motorcycle 204 as shown in the prior art of FIG. 2 . The flush fitting front turn signal 100 of the present invention presents a nearly seamless transition to a motorcycle fairing 104 .
As shown in FIGS. 3 and 4 , the flush fitting front turn signal 100 has a computer numeric controlled (CNC) machined aluminum housing 302 having a flat, planar, generally oval-shaped bottom surface 334 which is broader at one end than at the opposite end, and a preferably slightly convex top surface 308 . The top surface 308 slopes downward, so that the lateral surface 310 is taller at the broad end of the housing 302 than at the narrow end of the housing 302 . A first cylindrical bore 318 extends upward from the bottom surface 334 into the body of the housing 302 . A second cylindrical bore 320 coaxial with and merging into the first bore 318 extends downward from the top surface 308 into the housing 302 . The diameter of the first bore 318 is slightly greater than the diameter of the second bore 320 , defining a lip or ledge 340 at the junction between the first bore 318 and second bore 320 .
An LED assembly 304 , having a translucent dome 314 mounted on a slightly larger circular base 316 , is received by the first 318 and second 320 bores. When fully inserted into the housing 302 , the base 316 of the LED assembly 304 abuts the ledge 340 . The depth of the first bore 318 is predetermined to position the LED assembly 304 such that the translucent dome 314 extends beyond the top surface 308 of the housing 302 , thereby allowing light emitted from the LED assembly 304 to be visible from all directions.
As shown in FIG. 3 and further detailed in the exploded view of FIG. 4 , a circular printed circuit board 324 is adapted to engage the leads or pins of six LEDs 430 of the LED assembly 304 . The leads of the LEDs 430 are soldered to the printed circuit board 324 or other mechanical support. The LEDs 430 are divided into three pairs of series connected LEDs, which are then wired in parallel. A first 33 ohm, 1 watt current limiting resistor 328 is connected to the cathode end of the three parallel connected LED pairs, and a second 33 ohm, 1 watt current limiting resistor 326 is connected to the anode end of the three pairs. The schematic drawing shown in FIG. 5 illustrates the electrical connectivity between the LEDs, including first pair 430 a , 430 b , second pair 430 c , 430 d , and third pair 430 e , 430 f , and resistors 326 , 328 provided by the printed circuit board 324 .
The stripped ends 420 of two electrically conducting wires 306 , are soldered or otherwise secured to the circuit board 324 , and supply a DC voltage from the motorcycle battery across terminals T 1 and T 2 via a turn signal relay which flashes the LEDS 430 on and off at timed intervals to produce the flashing turn signal. A shrink-wrap cover 312 secures the wires together and, as shown in FIG. 6 , epoxy or another adhesive material securely retains the light assembly 304 , circuit board 324 , and wires 306 within the housing 302 .
The housing 302 is inserted from the outside of the motorcycle fairing 104 , the top surface flush with, the surface of the fairing 104 and the dome 314 protruding therefrom. On the inside of the fairing 104 , a bolt 322 , lock washer 414 , and washer 412 are received by a threaded blind bore 332 which opens on the bottom surface 334 of the housing 302 , and secures the housing 302 to the motorcycle fairing 104 . The housing 302 is designed to fit within the original equipment factory turn signal mounting hole without any modification to the vehicle bodywork. The housing 302 may be painted to match the fairing, or may have a raw, polished aluminum finish.
The LEDs 430 may be discrete components, or may be furnished in a six-chip, 12 pin dual in-line package (DIP), such as an L806TY3K available from Ledtronics, Inc. of Torrance, Calif. The LEDs 430 are preferably amber LEDS. The LEDs 430 are preferably high intensity LEDs, producing sufficient intensity that the flashing turn signal is visible in sunlight. The dome 314 may be either clear or tinted amber.
It is to be understood that the present invention is not limited to the embodiment described above, but encompasses any and all embodiments within the scope of the following claims. | The flush fitting front LED turn signal is adapted to provide a streamlined and nearly seamless transition to a motorcycle fairing. The present invention replaces bulky eternal front mounted motorcycle turn signals and utilizes the existing openings in the front fairing of the motorcycle. The present invention has an aluminum housing, and a LED assembly with a translucent dome extending outward from a bore within the housing. | 1 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority under 35 U.S.C. § 120 as a continuation of pending U.S. patent application Ser. No. 15 / 018 , 065 , filed 8 Feb. 2016 , which is a continuation of U.S. patent application Ser. No. 14 / 305 , 642 , filed 16 Jun. 2014 , now issued as U.S. Pat. No. 9 , 283 , 996 on 15 Mar. 2016 , which is a continuation of U.S. patent application Ser. No. 13 / 715 , 004 , filed 14 Dec. 2012 , now issued as U.S. Pat. No. 8 , 777 , 297 on 15 Jul. 2014 , the disclosures of which are incorporated by reference herein in their entireties.
BACKGROUND
Field
[0002] The present disclosure relates to the field of transportation aerodynamics. More specifically, disclosed is an apparatus to improve aerodynamic and fuel efficiency of an over-the-road cargo vehicle.
Related Art
[0003] The predominant mode of transportation for commercial goods throughout the United States, the developed world and elsewhere is cargo truck, among these including a tractor-trailer truck. For this mode of transportation, fuel represents the largest single cost component. Therefore, any measureable improvement in fuel efficiency of such vehicles is worthwhile.
[0004] In particular, in the developed world, where tractor-trailer trucks travel long distances of well-developed highways at a generally high speed, aerodynamic drag represents a major source of inefficiency. One source of such aerodynamic inefficiency is the geometry of the truck, which is essentially an elongated rectangular prism. In particular, the airflow properties over the trailing edge of the trailer create a large trailing negative pressure vortex, which greatly contributes to drag.
[0005] One recent technology to improve aerodynamic efficiency is colloquially called a “boat tail”. A boat tail is an attachment to the rear end of the trailer which acts as a fairing to gradually reduce the cross-sectional area of the trailer, and thus reduce the size and intensity of the trailing vortex and its associated drag. One investigation by the Platform for Aerodynamic Road Transport (PART), a research affiliate of the Delft University of Technology, Netherlands, suggests a boat tail can contribute a 4.5% improvement in fuel efficiency.
[0006] However, a boat tail as it is currently practiced has a practical size limit that still necessitates an abrupt geometry change at its trailing edge. Furthermore, a trailer is accessed via doors at its rear. Any sort of boat tail impedes access to such doors. For many such tractor/trailer trucks the container itself is transferable in order to be used by intermodal transportation (i.e., train, or cargo ship). In those circumstances, the aerodynamics are either substantially different (e.g. rail), or not even a concern (i.e., container ship). In such cases, the inviolable requirement is that the container keeps its standardized size and shape, to enable its intermodal transfer. Permanent alterations to the shape of the trailer to improve efficiency are, therefore, impossible, to say nothing of the cost-effectiveness in construction of a box trailer. Even an aerodynamically effective successful boat tail should therefore be temporary, removable or interchangeable for the most practical effect.
[0007] Furthermore, in loading or unloading, a road-use trailer is most commonly backed up to an elevated loading dock. Attempts to deal with this problem include making the boat tail inflatable, or foldable. Still, a boat tail remains an operational obstacle to loading and unloading.
[0008] Therefore, the present state of the art is lacking. Other solutions in place of or in addition to a boat tail may yield even better aerodynamic results and/or greater operational advantages.
SUMMARY
[0009] In order to overcome these and other weaknesses, drawbacks, and deficiencies in the known art, provided according to the present disclosure is an aerodynamic drag reduction device for use on an over-the-road cargo vehicle, the vehicle having a prismatically shaped cargo area, including a rear face of the cargo area substantially perpendicular to the direction of travel. The device includes a plurality of resilient prongs arranged along a rear edge of the vehicle body, each of the prongs extending from a respective fixed end secured to the vehicle body rearward in a flow-wise direction beyond the rear edge of the vehicle body to a respective free end. Each prong is separated from an adjacent prong in the plurality. Each prong is further flexible to permit deflection of the free end above and below a first plane defined by the surface of the vehicle to which the plurality of prongs is secured. Such deflection is caused by the properties of the airflow over the vehicle at a predetermined speed. Each prong is further resistant to deflecting in a direction parallel to the first plane.
[0010] Alternately or additionally, a shaft of each prong has a perpendicular cross section with an area moment of inertia that is lowest around a neutral axis of the cross section that is substantially parallel to the first plane.
[0011] Optionally, each prong may include a composite construction of two or more material sections, each material having a different modulus of elasticity. Each prong may optionally include a vulcanized rubber material in some embodiments. In certain embodiments, each prong has a substantially uniform cross-section. In others, each prong has a tapered cross-section, in height or width, or both. For certain embodiments of the present disclosure, each prong has radiused corners at its respective connection to the space separating it from an adjacent prong.
[0012] Further described according to the present disclosure, optionally the plurality of prongs are secured to the vehicle with the capability to be repositioned from a deployed position having the free ends extended beyond a rear edge of the vehicle body, to a retracted position having the free end nearer to or forward of the rear edge of the vehicle body. In some cases, the device is slidable in a flow-wise direction to reposition the prongs.
[0013] In other embodiments, the device is secured to a rotating frame member, which is operative to be rotated between the deployed position and a retracted position. For certain rotatable deployed embodiments, the device is itself rotatable on the rotating frame member to maintain an orientation of the prongs in a rearward extending direction. Optionally, the rotating frame member may be securable in one of the deployed or the retracted positions.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] These and other embodiments of the present disclosure will become apparent from the following detailed description read in connection with the accompanying drawings, wherein
[0015] FIG. 1 illustrates a generally conventional tractor-trailer cargo truck, having added thereto a drag-reducing airflow baffle according to the present disclosure;
[0016] FIG. 2 illustrates a detailed view of the upper rear portion of the cargo truck indicated by circle 2 in FIG. 1 ;
[0017] FIG. 3 illustrates a drag-reducing airflow baffle according to a first embodiment of the present disclosure;
[0018] FIG. 4 illustrates a cross-section view of one baffle prong taken along line 4 - 4 of FIG. 3 ;
[0019] FIG. 5 illustrates a drag-reducing airflow baffle according to a second embodiment of the present disclosure;
[0020] FIG. 6 illustrates a cross-section view of one baffle prong taken along line 6 - 6 of FIG. 5 ;
[0021] FIG. 7 illustrates on embodiment of a baffle-retracting scheme according to the present disclosure;
[0022] FIG. 8A illustrates a second embodiment of a baffle-retracting scheme according to the present disclosure, having the baffle retracted;
[0023] FIG. 8B illustrates the second embodiment of a baffle-retracting scheme according to the present disclosure, having the baffle in an intermediate position; and
[0024] FIG. 8C illustrates the second embodiment of a baffle-retracting scheme according to the present disclosure, having the baffle deployed.
DETAILED DESCRIPTION
[0025] Referring now to FIG. 1 , illustrated is a tractor-trailer truck, generally 100 , the features of which are largely conventional. While a tractor-trailer 100 is described, the present disclosure will be seen as applicable to any cargo vehicle with a prismatic shape of the cargo section, for example and without limitation, a box truck, a car-pulled trailer, or the like. The tractor cab 110 includes a cabin for the operators and an engine (not shown) to power itself and pull one or more attached trailers 120 . Airflow streamlines 130 , 140 depict the flow of air over the truck 100 at generally highway speeds, e.g., 60 miles per hour (MPH) or roughly 95 kilometers per hour (kM/h).
[0026] Attached to the rear of the trailer 120 is an airflow baffle 150 . Airflow baffle 150 is visible vertically in FIG. 1 , being attached to a near side on the trailer 120 . Not visible in FIG. 1 , is a further baffle 150 that can be mounted vertically at the rear of trailer 120 along an opposite side facing away from the viewer. Another baffle 150 may be mounted horizontally across a top of the trailer 120 , again extending rearward analogous to the baffle 150 shown in FIG. 1 .
[0027] The prismatic geometry of a standard trailer 120 , in particular the abrupt change of shape at its trailing end, creates a large low pressure vortex immediately behind the trailer 120 when there is airflow over the trailer 120 , for example at highway speed. This low pressure vortex is a large contributor to aerodynamic drag. In order to minimize the drag associated with this trailing vortex it is advantageous to control or influence the flow of air into the space immediately behind the trailer.
[0028] With reference to FIG. 2 , the upper rear end of the trailer 120 is depicted without any baffle 150 attached thereto to illustrate the typical airflow behavior. Experimental observation and computational fluid dynamics flow simulation indicates that, at the abrupt right-angle trailing edge of the trailer 120 the flow induced is characterized by a dynamic sinusoidal or wavelike pattern, generally indicated by streamlines 202 . This flow pattern is dynamic in the sense that the wave pattern shifts with a sinusoidal or wavelike characteristic as flow over the trailer 120 separates from the trailer 120 and mixes with fluid behind the trailer 120 . This sinusoidal or wavelike flow pattern is accompanied by mixing vortices 204 . In order to delay the separation of airflow from the trailer, and thus reduce drag formed by the separation, it would be beneficial if the surface of the trailer could be made to move with the sinusoidal or wavelike flow pattern. In this manner, the mixing of airflow over the trailer 120 into the trailing vortex would be controlled, and distributed over a greater volume as the separation is extended behind the trailer 120 . The intensity of the pressure differential behind the trailer 120 is therefore reduced, and with it the accompanying drag.
[0029] Referring Now to FIG. 3 , the flow baffle 150 provides prongs 152 that are positioned to extend in the flow-wise direction, generally aligned with a longitudinal axis of the trailer 120 , which can be seen as extending in parallel to the x-axis direction as depicted in FIG. 1 . Prongs 152 are separated from one another by spaces 154 , which spaces allow respective free ends 156 of individual prongs 152 to move independently of one another. Opposite the free end 156 of each prong 152 is a fixed end 158 . The free end 156 of each prong 152 is connected to a respective fixed end 158 by a shaft 162 . Fixed ends 158 may be secured to one another and the baffle 150 in general by a common spine 160 . The space between prongs 152 at the spine 160 may be provided with individual or blended fillets 164 , in order to avoid stress concentration. Alternately or additionally, the fixed ends 158 may be secured to the trailer 120 itself.
[0030] In a very particular embodiment, the prongs 152 are approximately 2 inches in width, between about 0.5 to 1 inches in thickness, and up to about 14 inches in length. Spacing 154 between the prongs 152 can be about 1 inch. However, these dimensions are offered as an example only, and should not be taken to limit the scope of the disclosure. These and other relevant dimensions are left to the particular application as determined by those skilled in the art taken in light of present disclosure.
[0031] The baffle 150 is secured to the trailer 120 to permit the shaft 162 of each prong 152 to extend, in whole or in part, rearward beyond a trailing edge of the trailer 120 . Moreover, the prongs 152 are resiliently constructed to permit their flexure above or below a plane defined by a side surface of the trailer 120 to which they are secured. The degree of resiliency and flexure will be subject to adjustment according to the individual circumstances. Among the factors to be considered are the dimensions of the trailer 120 , the design operating speed at which drag is to be minimized, resultant Reynolds number for the particular flow, etc. As a first order approximation, prongs 152 constructed of vulcanized rubber display what is considered to be an adequate degree of resiliency for the present application.
[0032] Composite makeup may be employed as well, for example the prongs having a core of a harder material, ductile metals, resilient plastics or the like, with additional flexibility afforded by a covering of more flexible material over this core. Optionally, some or all of the baffle 150 in gross may have the same composite construction as the prongs 152 . The cross-sectional view of the prong 152 indicates a composite construction, including a core 168 having an alternate material, in particular a differing modulus of elasticity, as the material comprising the remainder of the prong 152 . The cross-sectional shape of the core 168 need not necessarily conform to that of the prong 152 as a whole. Moreover, the length of the core 168 may optionally be less than that of the prong 152 . The core 168 may have a uniform cross-section, or it may taper or otherwise change in cross-sectional area without regard to the shape of the prong 152 .
[0033] The precise cross-sectional dimension of the prongs 152 will also affect the flexibility of the prongs 152 . Generally speaking, it is considered desirable that the prongs have flexibility to deflect above or below the designated mounting plane, but only limited flexibility laterally within the mounting plane. To this end, the cross-sectional geometry should exhibit a greater area moment of inertia (alternately called second moment of area) around any axis extending out of the mounting plane as compared with the area moment of inertia around any axis lying in or parallel to the mounting plane. As a result, the prongs will resist flexing around any axis having a higher area moment of inertia, which can be by designing an axis lying parallel to the mounting plane.
[0034] As an example only, and with reference to FIG. 4 , a cross-section view of the prong 152 taken along section line 4 - 4 in FIG. 3 , illustrates that the prong 152 , and particularly its shaft 162 , have a lowest area moment of inertia around the horizontal axis 165 passing through the center of the shaft 162 . In certain embodiments, the corners 166 of the shaft 162 may be rounded to avoid stress concentrations and improve durability in service.
[0035] Referring now to FIG. 5 , illustrated is an alternate embodiment of a baffle, generally 250 . A full description of the features common with the foregoing embodiment of FIGS. 3-4 will be apparent to those skilled in the art, and the following description will highlight the differences therewith. Baffle 250 has prongs 252 separated from one another by spaces 254 . The shaft 262 of each prong 252 is tapered in its width as it extends rearwardly in a flow-wise direction, with a taper angle 270 defined by θ. FIG. 6 is a cross-section view of the prong 252 taken along section line 6 - 6 in FIG. 5 . Here again, the prong 252 , and particularly its shaft 262 , have a lowest moment of inertia around the horizontal axis 264 passing through the center of the shaft 262 . Accordingly, they will tend to flex above or below the mounting plane, and resist lateral deflection within or parallel to the mounting plane. Alternately or additionally, the prong cross-section may be tapered in height to influence the propensity of the prong to deflect vertically (as viewed in FIG. 4 or 6 only; the prepared axis of deflection will generally be laterally for baffles installed on a side surface of the trailer) rather than horizontally.
[0036] The cross-sectional view of the prong 252 indicates a composite construction, including a core 268 having an alternate material, in particular a differing modulus of elasticity, as the material comprising the remainder of the prong 252 . Notably, the cross-sectional shape of the core 268 need not necessarily conform to that of the prong 252 as a whole. Moreover, the length of the core 268 may optionally be less than that of the prong 252 . The core 268 may have a uniform cross-section, or it may taper or otherwise change in cross-sectional area without regard to the shape of the prong 252 .
[0037] A trailer 120 fitted with one or more baffles 150 , 250 , obtains its benefit of drag reduction in transit at highway speeds. However, such a trailer 120 should preferably be compatible with the existing trucking infrastructure in other phases of operation, namely loading and unloading. Loading and unloading of the trailer 120 is most commonly accomplished by one or more doors at the rear face 122 of the trailer 120 . Moreover, for this purpose, a raised loading dock (not shown) is commonly provided level with the bottom 125 of the trailer 120 . The height of such a dock is generally standardized. In order for the trailer 120 to be backed into position adjacent to such a loading dock for loading and unloading, it is desirable that the baffles 150 or 250 be retractable such that they do not extend beyond the rear face 122 of the trailer 120 .
[0038] Referring now to FIG. 7 , illustrated is a mounting arrangement where the baffle 150 is mounted to the trailer 120 in a manner that permits the baffle 150 to be shifted along a longitudinal axis of the trailer 120 . In particular, a plurality of pegs 180 is provided on the trailer 120 , which fit respectively into one or more of in spaces 154 between adjacent prongs 154 . Accordingly, the baffle 150 can slide longitudinally along the trailer 120 from a position with free ends 156 extended beyond the rear face 122 of the trailer 120 , as shown in FIG. 7 , to a retracted position having the free ends 156 longitudinally forward of the trailer rear face 122 (not shown). Moreover, the baffle 150 may be adapted to be secured in one of several intermediate positions as well. With the baffle 150 retracted, it does not impact nor interfere with the trailer 120 backing into a loading dock, nor access to the trailer 120 from the loading dock. The baffle 150 may be secured in the extended, retracted, or any intermediate position by any number of conventional means known in the art.
[0039] FIGS. 8A-8C illustrate an alternate mounting embodiment for baffles 150 . In this embodiment, one or more baffles 150 are mounted to a pivoting frame 310 . The pivoting frame is mounted to the trailer by a plurality of mounts 312 . A handle 314 is attached to the frame 310 to allow a user to pivot the frame 310 between retracted and deployed positions. One or more handle latches 316 , 318 are provided to hold the handle 314 , and thereby the frame 310 , in either the retracted or extended positions, respectively.
[0040] Baffles 150 are carried by the frame 310 on arms 320 , such that a rotation of the frame 310 from its retracted position illustrated in FIG. 8A , to an intermediate position illustrated in FIG. 8B , places the baffles 150 with the fixed ends 158 in proximity to the rear face 122 of the trailer 120 . From this intermediate position of FIG. 8B , in this particular embodiment, the baffles 150 may be mounted to the arms 320 in a pivotal manner, such that the baffles 150 are rotated into an operating position illustrated in FIG. 8C , having the free ends 156 of the prongs 152 extending rearward beyond the rear face 122 of the trailer 120 . Thus, with the frame 310 holding the baffles 150 in their retracted position of FIG. 8A , the baffles 150 may nonetheless be stowed with the free ends 156 of the prongs 152 generally aligned with a direction of airflow. In other embodiments, the operator of the trailer 120 might find it convenient to operate the trailer 120 with the baffles 150 in a position having the prongs 152 forward-facing.
[0041] The foregoing examples of baffle retraction in FIGS. 7, 8 are depicted on a side surface of the trailer 120 . They will be understood to be equally applicable to the opposing side surface and/or a top surface of the trailer 120 as well. Furthermore, the baffle 150 as described herein will be seen as equally applicable to other vehicles, or portions thereon, including for example and without limitation the arrangement of a baffle 150 or 250 as described herein to the tractor cab 110 .
[0042] It will be appreciated that variants of the above-disclosed embodiments and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims. | An aerodynamic drag reduction device for use on an over-the-road cargo vehicle. The vehicle has a prismatically shaped cargo area, which includes a rear face of the cargo area substantially perpendicular to the direction of travel. The device comprises a plurality of resilient prongs arranged along a rear edge of the vehicle body, extending from a respective fixed end secured to the vehicle body rearward in a flow-wise direction beyond the rear edge of the vehicle body to a respective free end. Each prong is separated from an adjacent prong in the plurality, and each is flexible to permit deflection, under the influence of airflow over the vehicle at a predetermined speed, above and below a first plane defined by the surface of the vehicle to which the plurality of prongs is secured. Each prong is further resistant to deflecting in a direction parallel to the first plane. | 1 |
BACKGROUND OF THE INVENTION
[0001] In a principal aspect, the present invention comprises a carry strap for baggage or luggage which is capable of simultaneous cooperation and thus use with three items of luggage so that those three items may be carried and transported easily together as a unit.
[0002] Movement of luggage when traveling, especially airline travel, is often challenging because of multiple pieces of cumbersome luggage which must be transported. That is, very often, multiple pieces of luggage must be simultaneously transported by a single person. Carrying two or more pieces of luggage is, for many, a difficult undertaking.
[0003] Currently, there are available luggage items such as carry-ons and larger luggage items which include wheels and a telescoping handle to facilitate luggage movement. Further, it is generally common to have a short strap which will attach to the handle or a post of a first luggage item to a second luggage item so that the luggage items may be bundled together.
[0004] Nonetheless, there remains the difficult problem of how to handle or move more than two luggage items. For example, pulling two luggage items which are bundled together in the manner described above plus carrying a further suitcase, valise, or the like, remains a difficult problem. Thus, an improved method or means to move multiple pieces of luggage by a single individual in a compact, easily accessible, easily usable manner is desired. These objectives, among others, have inspired the development of the luggage carry strap of the invention.
SUMMARY OF THE INVENTION
[0005] Briefly, the present invention comprises a carry strap which can be used to carry at least three items of luggage in a unitary or bundled manner with those items of luggage, in effect, stacked or juxtaposed one against the other and wherein one of the luggage items, which includes a telescoping handle and wheels, may be relied upon to support and transport the other luggage items. The carry strap includes a clamshell type attachment, clasp or clip for attachment to the luggage item which includes the telescoping handle and wheels. The clasp is attached by means of a first, adjustable strap to a second luggage item stacked against the wheeled luggage item. A ring member is provided for the first flexible strap. A second flexible strap is attached by means of an adjustable buckle to the ring member. The second adjustable strap may then be engaged with the handle of a further or third luggage item stacked against the other two luggage items in the array. Additional strap members may be incorporated in a similar fashion so that more than three luggage items may be stacked one upon the other and wherein all of the luggage items are arrayed in a manner which promotes their stability, yet enables a single, wheeled, telescoping handle luggage item to serve as the platform and carrying vehicle for the assembled items of luggage.
[0006] Thus, it is an object of the invention to provide an improved carry strap for the simultaneous carriage of multiple items of luggage.
[0007] It is a further object of the invention to provide a luggage carry strap which includes a series of flexible straps associated with adjustable buckles to enable adjustment of the length of the various connected straps and thereby accommodate luggage items of various sizes.
[0008] Another object of the invention is to provide a carry strap device which includes a clamp or clasp that can be used to releasably attach the carry strap construction to a wheeled luggage item.
[0009] Another object of the invention is to provide a lightweight, yet structurally strong and highly flexible carry strap for use in association with three luggage items simultaneously so as to enable the simultaneous carriage of those three items in a packed array by a single person in an efficient manner wherein the balanced or stacked luggage items are maintained in a stable condition for movement or transport.
[0010] Another object of the invention is to provide a carry strap which is inexpensive, rugged, easy to use and which can accommodate luggage items of numerous sizes and configurations.
[0011] These and other objects, advantages and features of the invention will be set forth in the detailed description which follows.
BRIEF DESCRIPTION OF THE DRAWING
[0012] In the detailed description which follows, reference will be made to the drawing comprised of the following figures:
[0013] FIG. 1 is an isometric view of the carry strap of the invention as it is utilized to support three separate and uniquely shaped and constructed items of luggage;
[0014] FIG. 2 is an isometric view of the carry strap construction utilized in the embodiment and in the manner depicted in FIG. 1 ;
[0015] FIG. 3 is an alternate construction of the carry strap of the invention;
[0016] FIG. 4 is a diagrammatic view of a version of the strap of the invention; and
[0017] FIG. 5 is a diagrammatic view of an alternative version of the strap of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0018] Referring to FIG. 1 , typical luggage items which benefit from the use of the present invention are illustrated in combination with the luggage strap of the invention. A wardrobe sized luggage item 10 having a telescoping handle 12 and wheels, such as wheels 14 , is provided with a carry handle 16 at its upper end. A second luggage item 18 , which does not necessarily include a telescoping handle or wheels but does include a carry handle 20 , may be positioned and maintained in position or stacked against the first luggage item 10 by utilization of the present invention. A third luggage item 22 of another size, for example, the size of a valise, may or may not include a telescoping handle. The third item 22 does include a carry handle 24 or an equivalent structure to a carry handle 24 . The third item of luggage 22 is stacked and held in position against the second item 20 . Although there are luggage items of various sizes in FIG. 1 , the invention accommodates luggage items which may be similarly sized as well as luggage items having different shapes, configurations, thicknesses and the like. Preferably, however, at least one of the luggage items includes a telescoping handle such as the first luggage item 10 , and further includes wheels, such as wheels 14 , to enable the more efficient use of the separate carry strap of the invention.
[0019] A function of the carry strap of the invention is to couple the various luggage items 10 , 18 and 22 in a manner which enables them to be appropriately balanced and arrayed so that they can be easily moved and carried merely by extending the telescoping handle 12 and moving the assembly on the rollers or wheels 14 . Thus, the carry strap is comprised of flexible strap members and adjustable buckle elements or buckles which coact with the handles 16 , 20 and 24 (or equivalent) so as to facilitate the functional objectives.
[0020] The carry strap of the invention includes a clamp member or handle clasp 30 which, in a preferred embodiment, is comprised of a first shell-shaped or rigid arcuate member 32 such as manufactured from a molded plastic material joined by a pivot pin or hinge 34 to a second clasp member 36 which in a preferred embodiment is generally arcuate. However, the clasp members 32 , 36 may be made from metal, metal wire, and may or may not include a pivot connection. Thus, numerous types of clasp members or handle clasps may be utilized in the practice of the invention.
[0021] A first flexible strap 38 is joined to the clasp 30 at a first end 40 . The flexible strap 38 is preferably an inch or two in width. In the preferred embodiment the first flexible strap 38 is sewn to or attached to a ring member 42 at the end 41 distal from the first end 40 connected to the clasp 30 . The ring member 42 may be a metal ring or a molded plastic ring, or some other type of material may be used to make the ring member 42 . In the preferred embodiment, the ring member 42 is a generally rectangular ring member with a width slightly greater than the width of the strap 38 .
[0022] A second flexible strap 44 includes a first end 46 which is attached to a buckle element 48 . The attachment of the first end 46 to the buckle element 48 is adjustable inasmuch as the first end 46 may be adjusted in length through the element 48 . The second strap 44 is fitted through a second ring element 50 similar in size, shape and construction to the first ring element 42 . The second strap 44 may be fitted around a leg 52 of the ring element 50 and sewn by stitching 54 so as to be fixed to the ring element 50 . Alternatively, the second strap 44 may slidably pass through the ring 50 .
[0023] The second strap 44 also is passed through the ring 42 as depicted, for example, in FIG. 2 . Again, the second strap 44 may be sewn in the manner depicted with respect to the ring 50 or slidably passed through the ring 42 .
[0024] The second end of the second strap 44 ; namely, the second end 56 is attached to a second buckle element 58 . The attachment to the second buckle element 58 may be adjustable or non-adjustable. In any event, the distance between the ring elements 42 and 50 is adjustable by means of the cooperative relationship between strap 44 and adjustable buckle elements 48 and/or 50 . In other words, numerous alternative connections may be effected between the rings 42 and 50 by means of flexible second strap 44 to accommodate the concept and functionality of adjustment of the distance between the rings 42 and 50 . For example, it is not necessary that each of the ends 46 and 56 be adjustably connected to a respective buckle member or element 48 , 58 . Only one of those ends 46 , 56 need be adjustable. Various other interconnections of the rings 42 and 50 via the strap 44 and the adjustable buckle element 48 may be effective to adjust the distance between the rings 42 and 50 .
[0025] In a similar fashion, a third flexible strap 60 is connected to the ring member 50 as well as to an adjustable buckle 62 . The opposite ends of the third strap 60 ; namely, a first end 64 and second end 66 may be adjusted in order to adjust the effective length of the third flexible strap 60 . Thus, the third flexible strap 60 may be sewn in place by means of a seam 68 to the ring element 50 . Alternatively, the seam 68 may be omitted. Each of the first and second ends 64 and 66 may be attached to the adjustable buckle elements 64 . Again, the effective length of the third flexible strap 60 is accommodated by means of the adjustable buckle 64 working in combination with one or both first and second ends 64 and 66 as well as the ring 50 .
[0026] FIG. 2 depicts a preferred embodiment wherein the third flexible strap 60 is fixed to the ring 50 by means of the seam 68 .
[0027] Referring to FIG. 3 , an alternative arrangement is depicted wherein a first end 67 of the strap 60 feeds through a buckle element 70 and is then attached to ring 50 along a seam 68 . Thus, the second end of the third strap 60 ; namely, second end 64 may be adjustably attached to the buckle element 65 . Again, adjustment of the effective distance or length of the third flexible strap 60 is established by virtue of the coaction of the adjustable buckle 65 and its interaction with the flexible strap 60 .
[0028] It should be noted that a strap may be a single continuous elongate web or may comprise elements which are joined one to the other through stitching or by other means to form a completed connection through ring members and through buckle mechanisms which are adjustably connected to the strap. Thus, the buckle mechanisms may have adjustment features associated with the separate elements comprising the buckle mechanism since a buckle mechanism typically will comprise first and second buckle member elements and each one of those separate buckle member elements will be separately attached to a belt member or strap member. Though each attachment may be adjustable, at least one of the attachments is preferred to be adjustable.
[0029] FIGS. 4 and 5 illustrate diagrammatically various arrangements of buckle members, straps and rings. In FIG. 4 , for example, adjustable buckle elements 70 and 72 connect with opposite ends of a strap 74 . The strap 74 passes through a ring 76 and is sewn in position along seam 71 with respect to the ring 76 . One end 77 of the strap 74 connects to the adjustable buckle element 70 . The other end 79 connects adjustably with element 72 . Thus, in this embodiment, both of the buckle elements 70 and 72 are adjustably connected to a single strap 74 . However, only one of the buckle elements needs to be so adjustable.
[0030] In FIG. 4 , ring element 76 may coact with a strap 78 which, in turn, fits through a second ring element 80 and connects to an adjustable or non-adjustable buckle element 82 . The opposite end 81 of the strap 78 connects to a second buckle element 84 which may or may not be adjustable. An attachment clasp 86 is attached by a strap 88 to ring 80 . This is one arrangement of the connection of strap and buckle elements.
[0031] FIG. 5 illustrates a separate arrangement. In this second arrangement, a strap 89 is connected adjustably at one end 91 to a buckle element 90 and opposite end 93 fits through a second buckle element 92 in an adjustable fashion and further is connected by the end of the strap 89 to a ring 94 . Thus, the end 93 is attached to the ring 94 . A second strap 100 fits through ring 94 and is fixed thereto by virtue of a seam. The opposite ends 101 , 102 of strap 100 cooperate adjustably with buckle elements 103 , 104 . End 101 is fitted through ring 106 . Clasp 107 is attached by strap 108 to ring 106 .
[0032] In use, as depicted in FIG. 1 , the clasp 30 is positioned around the handle 16 . The length of the second adjustable strap 44 is adjusted and the flexible buckle 48 is opened to permit attachment of strap 44 to the handle 20 . The third strap 60 is similarly adjusted in length and attached to handle 24 . As can be seen, therefore, the construction and adjustment of the carry strap of the invention may be effected in many distinct ways. Further, the construction of the buckle elements, the rings, the flexible straps, as well as the clasps, may all be varied and still considered within the scope of the invention. The invention is therefore limited only by the following claims and equivalents thereof. | A carry strap for simultaneously supporting three luggage items includes a strap member attachable to a first wheeled luggage item, a second flexible strap which supports a second luggage item and a third flexible strap which connects from the second strap to a third luggage item. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to a wafer processing method and apparatus used for the fabrication of an integrated circuit (IC) semiconductor, more particularly, the present invention relates to a plasma processor and method having an improved processing rate and which is used for etching during IC fabrication.
Since the beginning of the IC industry, a wet etching method has been employed utilizing sulphuric acid, hydrochloric acid or phosphoric acid, however, recently the wet etching method has been replaced by a dry etching method, such as a plasma etching method. A plasma etching process has various advantages in comparison with the wet etching method, such as higher resolution, less undercutting, inherent cleanness, and a reduction in the number of fabricating processes, such as elimination of wafer rinsing and drying. Plasma etching, according to the present invention, in particular, makes it possible to perform sequential etching and stripping operations on the same machine, making it possible to realize fully automated IC fabrication.
A plasma is a highly ionized gas having a nearly equal number of positively and negatively charged particles and free radicals. The free radicals generated in plasma, act as a reactive species, chemically combine with materials to be etched, and form volatile compounds which are removed from the wafers by a vacuum.
During a process for forming fine patterns in the IC device, an etching process is performed, and in particular, the etching process includes both a true etching process and an "ashing" process which may be defined as a process for removing a photoresist mask which is usually an organic layer. The true etching process etches off the protective layers of silicon, silicon dioxide, etc. When ashing, oxygen (O 2 ) is usually used as an etchant gas, and when etching a gas mixture of carbontetrafluoride (CF 4 ) or carbon-tetrachloride (CCl 4 ), etc. are used at a specified temperature and pressure.
Plasma processors can be classified into two types. In the first type a plasma is generated in a plasma generator and the activated plasma gas is introduced to the wafers in a separate location. In the second type, the wafers are placed in the plasma generating area. The first method is very slow and results in a wafer surface which is not uniform. The second method damages the wafer in the plasma environment due to bombardment by ions, ultraviolet rays, and soft X-rays, and, in addition, the wafer is contaminated with impurities from the plasma gas, resulting in widely varying quality of the wafer surfaces.
SUMMARY OF THE INVENTION
It is an object of the present invention, therefore, to provide a plasma processing method and processor having a high processing rate and providing a uniform wafer surface after the etching process.
It is another object of the present invention to provide an etching process that can be completely automated.
It is an additional object of the present invention to improve the safety of the etching process for an operator.
It is a further object of the present invention to improve the quality of etched wafers.
A plasma processor in accordance with the present invention comprises an airtight chamber having a plurality of holes arranged in a base plate of a wafer processing space through which an activated plasma gas is introduced. The wafer is placed on the base plate with the surface to be etched facing downward. The wafer is processed by the activated etchant gases which are blown out of the holes in the base plate. The wafer is floated and rotated by jet streams of the etchant gas issuing from the holes while the wafer is being etched. Therefore, the wafer can be etched uniformly at a high processing rate without being affected by ion bombardment, ultraviolet radiation or soft X-rays, resulting in the reliability and yield of the wafer production process being improved.
These together with other objects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates the principle of a plasma processing method according to the present invention;
FIG. 2(a) is a side view of the base plate using the principle of plasma processing according to the present invention and FIG. 2(b) is a top view;
FIG. 3 is a side view, partially in cross-section, of a base plate having heaters, according to another principle of the plasma processing method of the present invention;
FIG. 4 is a side view, partially in cross-section, of the base plate holes, of still another principle used in the plasma processing method according to the present invention;
FIG. 5 is a plan view of the base plate of still another principle used in the plasma processing method according to the present invention; and
FIG. 6 is a schematic diagram of a plasma processor system including the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows schematically the principle of a plasma processing method according to the present invention. The plasma processor comprises a plasma generating region 12, which is separated from a reacting region 4 (reactor) in an airtight reaction chamber 11, and a pumping device 17. A wafer 1 is placed on a base plate 15 with the surface to be etched facing downward. Air in the reaction chamber 11 is exhausted by the pumping device 17, and the etchant gas is supplied from an etchant gas source 2 into the reacting region 4. When microwave energy 7 generated by a microwave generator 3 is transmitted into the plasma generating region 12, the gas is ionized. Radicals with chemically active species are generated in the plasma generating region 12 and fed into a cavity 15a. The activated etchant gas rushes out of holes 13 into the reacting region 4, forming etchant gas jet streams. The wafer 1 is floated above the top of the base plate 15c by the etchant gas jet stream, and at the same time, the wafer is etched. That is, the radicals reaching the surface of the wafer 1 act on the material of the wafer 1 forming volatile compounds. The compounds and etchant gases are removed by the pumping device 17 through an exhaust tube 16.
Oxygen (O 2 ) plasma gas, for example, is generated in the plasma generating region 12 by microwave energy at a frequency of 2.45 GHz and introduced into the cavity 15a, arranged inside of the base plate 15. The oxygen plasma gas is blown out of the gas holes 13, each of which is a fine nozzle. Pressure in the reacting region 4 in the reaction chamber 11 is maintained at about 1 Torr and the pressure of the cavity 15a is maintained at about 2-3 Torr resulting in a pressure differential between reacting region 4 and cavity 15a causing the jet streams to issue from holes 13. The radicals of the etchant gas are pressed into the space between the wafer 1 and the surface of base plate 15 and the wafer 1 floats. The gas flows out, as shown by an arrow in the figure, through a space between the wafer 1 and a guide 14. While the wafer 1 floats at a height of 0.1-1.0 mm, it is protected from drifting off the base plate 15 by the guide 14. The flat uniform stream of etchant gas between the floating wafer 1 and the base plate 15 etches the wafer 1 uniformly at a high rate as compared to the conventional etching method. The gases used for processing are also saved, in comparison with a conventional plasma etching processor, by exhausting through the exhaust tube 16 using the pumping device 17.
FIG. 2(a) is a side view and FIG. 2(b) is a top view of the top of the base plate of the present invention. A plurality of gas holes 13 can be arranged about 10 mm apart. The gas holes can be from 0.5 mm to 2.5 mm in diameter depending on the desired volume of gas outflow which can be used to control the etching rate. The axis of the holes are vertical to the surface of the base plate and the base plate 15 is made of aluminum or titanium.
FIG. 3 illustrates another plasma processing method according to the present invention. The difference between the base plate of FIG. 3 and that of FIG. 1 is that heater elements 18 and a temperature control unit 19 are additionally provided During plasma processing, the etchant gas in the holes 13 is heated by the heating elements 18 and, as a result, the wafer 1 is heated to a proper processing temperature by the etchant gases. The processing temperature is controlled by the temperature control unit 19. When the wafer is heated up, it is possible to perform the etching process at a higher rate. It is preferable that the operating temperature of the wafer during etching be about 150° C. to obtain a high processing rate.
FIG. 4 is a side view, partially in cross-section of the gas holes, of still another principle of a plasma processing method according to the present invention. The difference between the construction of the holes 21 of FIG. 4 and those of FIG. 1 is that the base plate holes 21 are arranged in the base plate 15, with their axes inclined with respect to the surface of the base plate 15 at an angle of inclination from 30 to 60 degrees. The etchant gas flows as shown by an arrow in FIG. 4 and the wafer 1 is moved to the right. As a result, the wafer 1 is etched by the etchant gas and, at the same time, the wafer is transported by the etchant gas in a manner similar to the way an air-bearing transports a wafer which is a widely used method of transfer in wafer handling systems. The system of FIG. 4 can be utilized as a plasma processing system and a wafer transfer system at the same time. It is also possible to switch from a plasma processor to an air-bearing system by merely switching the gas issuing from the holes.
FIG. 5 is a plan view of the base plate of still another principle of a plasma processing method according to the present invention. The difference between the base plate of FIG. 5 and FIG. 1 is that the gas holes 22 are arranged to rotate the wafer. The gas holes 22 are positioned on concentric circles around the center of the base plate 23 and each hole slants with respect to the surface of the base plate 23 about 45 degrees, for example, in a tangential direction to the circle. In a preferred embodiment of FIG. 5, the holes 22 are arranged at regular intervals on two concentric circles 22a and 22b around the center of the base plate 23, and gas jets flow from the holes, float the wafer and rotate it at a desired speed during plasma processing. The application of such rotational processing, increases the uniformity of the processed wafer even further than previously discussed methods.
The heater 18 and the temperature control unit 19 are also applicable to the embodiments of FIGS. 4 and 5 and further raise the processing speed. The application of the heater 18 to FIGS. 4 and 5 will be easily understood by one of ordinary skill in the art, and for the sake of simplicity, the explanation thereof has been omitted.
FIG. 6 is a schematic diagram of a plasma processor system embodying the present invention and results in a totally automated operation which does not require manual handling of wafers or wafer trays. Wafer loading is accomplished through vacuum load lock spaces 26a and 26b, so that the reaction chamber 11 is maintained at a specified gas pressure and is not exposed to the ambient environment. The load lock space 26a comprises an airtight space between an entrance gate valve 38a and a slit gate valve 39a. The slit gate valve 39a is used for communicating between the load lock space 26a and the reaction chamber 11. The entire process sequence is microprocessor controlled through a control module (not shown).
During operation of the system of FIG. 6, a wafer 1 is transported on polyurethane belt 34a and the wafer moves into position over the vacuum chucks 29a. Before the entrance gate valve 38a is opened, a slit gate valve 39a is lifted up by an up and down mechanism 31a and pressed against the upper wall of the reaction chamber 11. The space surrounded by the entrance gate valve 38a, the slit gate valve 39a and the wall of the reaction chamber 11 provides the airtight load lock space 26a. The gas in the load lock space 26a is evacuated and replaced by air through a pressurizing system 41, and the replacement is accomplished very quickly, since the volume of the load lock space 26a is very small (for example, 5 mm high and 15 cm in diameter).
The entrance gate valve 38a is then pulled up by an open and close mechanism 36a. The wafer 1 is chucked by a vacuum chuck 29a, and turned over by the reversing mechanism 30a, and placed on a stage 5. The entrance gate valve 38a is again closed by the open and close mechanism 36a. Air in the load lock space is replaced by gas from the reaction chamber 11 and the slit gate valve 39a is pulled down by the up and down mechanism 31a. In this way, the wafer is taken into the reaction chamber 11, without disturbing the condition of the reaction chamber 11. As a result, plasma processing can continue while a wafer is being in or taken out. Next, the wafer is chucked by a chuck 9a on an arm 8a which is rotated by a rotation mechanism 32a. The wafer 1 is transferred onto the stage 6 (shown as a dotted line) in the base plate 15. The wafer is then lowered onto the base plate 15, and can now be etched using the floating wafer processing method of the present invention.
Oxygen (O 2 ) plasma gas, for example, is generated in a plasma generating region 12, by microwave energy at a frequency of 2.45 GHz and introduced into a cavity 15a through an isolator 10. The isolator 10 is a dielectric window formed in a waveguide 40 for defining a portion of the plasma generating region 12, the dielectric window transmits the microwave radiation therethrough. Oxygen plasma gas is blown out of the gas holes 13 in the base plate 15, which are provided with heater elements 18 and a temperature control unit 19. Pressure in the reacting region 4 in the reaction chamber 11 is maintained at about 1 Torr, the pressure in the cavity 15a is maintained at about 2-3 Torr and the gas is blown out by the differential between these pressures. The radicals of the etching gas are pressed into the space between the wafer and the top surface of the base plate 15 and the wafer floats due to the pressure of the gas. The gas flows from a space between the wafer 1 and the guide 14. The floating wafer height is controlled by the gas pressure at 0.1-1.0 mm and the wafer 1 is kept from drifting off the base plate 15 by guide 14. The flat uniform stream of the etchant gas between the wafer and the base plate 15 etches the wafer uniformly at a high processing rate. The gases used for the processing are saved by exhausting the compounded gases through the exhaust tube 16 and the pumping device 17.
The wafer to be unloaded is chucked by rotation mechanism 32b, and moved to stage 7 on the slit gate valve 39b. Next, by using the up and down mechanism 31b, the wafer is moved up into the load lock space 26b. Then, the wafer is closed in the load lock space 26b, and the gas in the load lock space 26b is evacuated and replaced by air through the pressurizing system 41. The load lock valve 38b is opened, by an open and close mechanism 36b, the wafer of the stage 7 is chucked, and turned over by the reversing mechanism 30b. The unloaded wafer is loaded onto a return belt 34b and the load lock space 26b is filled with gas from the reaction chamber 11. The processed wafer is transported to a receiver cassette (not shown) and the cycle of the processor is completed.
In the plasma processor of FIG. 6, the reacting region 4 must be airtight, since the etchant gas is dangerous to the operator and should not be contaminated by moisture or dust from the environment. Therefore, packing or O-rings are provided around the moving shafts or gate valves 38a, 38b and 39a, 39b and the gas in the reaction chamber 11 is kept at a specific pressure by the pumping system 17. For example, the pressure of an etchant gas of carbon-tetrafluoride (CF 4 ) or carbon-tetrachloride (CCl 4 ) in the reacting region 4 of the reacting chamber 11 is kept at about 0.3 Torr.
The load lock processing provides several benefits in that it isolates the reaction chamber from the atmosphere and provides for thermal as well as pressure and gas flow stability. It also reduces the air and moisture content in the chamber which improves both etching reproducibility and process uniformity. The load lock operation also provides increased safety so that the operators are no longer exposed to the etchant gases used during plasma processing.
The system can be operated in a continuous processing mode, that is, while one wafer is in process, another wafer can be taken in or taken out of the reaction chamber so that productivity is increased. The throughput of the system of FIG. 6 in the continuous mode is 60 percent higher than in the standard operating mode (which is similar to a manual system). Etching uniformity is enhanced by the rotating process system and the etching rate is increased up to about 6 μm/min., which is almost twice as fast as that of a conventional plasma processor system.
As described above, according to the plasma processor of the present invention, the etching process is performed at a higher speed and etching uniformity is increased as compared to a conventional plasma processor.
The many features and advantages of the invention are apparent from the detailed specification and, thus, it is intended by the appended claims to cover all such features and advantages of the system which fall within the true spirit and scope of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and, accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. | A plasma processor, for dry etching during a fabricating process for an integrated circuit semiconductor device, including a plasma generating region formed in a waveguide into which microwave power is transmitted. An etchant gas is introduced into the plasma generating region and a plasma is generated. The plasma generating region and a reacting region are kept at a specific gas pressure differential by an evacuating device. The radicals (active etching species) react with the underside of a turned wafer placed on a base plate in the reacting region because the gas is blown against the underside of the wafer by the pressure differential. In particular, the wafer is etched by etchant gases floating the wafer by blowing the gases out of holes in the base plate. The floating wafer processing method provides a higher processing rate and better etching uniformity. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims benefit of U.S. provisional patent application Ser. No. 61/422,497, filed Dec. 13, 2010, which is herein incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
Embodiments of the present invention generally relate to a cooler. More particularly, embodiments of the present invention relate to a cooler for transferring a game head.
2. Description of the Related Art
During the hunting season, a hunter will hunt wild game animals, such as a buck. After the hunter has killed a wild game animal, the hunter may want to transport the head (e.g., game head) of the wild game animal from the hunting location to a taxidermist in order to mount the game head. It is important to keep the game head cool and protect the game head during transport so that the game head will not get damaged. There is a need therefore for a method and an apparatus to cool and transport the game head from the hunting location.
SUMMARY OF THE INVENTION
The present invention generally relates to a cooler for transferring a game head. In one aspect, a game head transfer device is provided. The game head transfer device includes a body having an opening on an upper portion that is configured to receive a game head into the body, wherein a first portion and a second portion of the game head extend from the opening of the body when the body is in an opened position and a closed position. The game head transfer device further includes one or more flap members configured to narrow the opening of the body between the first portion and the second portion of the game head that extend from the opening. The game head transfer device also includes one or more closing members configured to narrow the opening of the body adjacent a side of the first portion and a side of the second portion of the game head that extend from the opening.
In another aspect, a method of using a game head transfer device is provided. The method includes the step of inserting a game head into an opening of the device, wherein a first portion and a second portion of the game head extend from the opening. The method further includes the step of narrowing the opening of the device between the first portion and the second portion of the game head that extend from the opening. The method also includes the step of further narrowing the opening of the device adjacent a side of the first portion and a side of the second portion of the game head that extend from the opening.
In yet another aspect, a cooler for a game head is provided. The cooler includes an insulated body having a transport area that is configured to receive a game head into the body such that a portion of the game head extends from an opening of the insulated body when the insulated body is closed. The cooler further includes a first flap member and a second flap member that are configured to close around the portion of the game head that extends from the opening. The cooler also includes a first closing member and a second closing member that are configured to narrow the opening of the insulated body.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of 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.
FIGS. 1 and 2 are views illustrating a game head transfer device.
FIG. 3 is a view illustrating the game head transfer device in an open position.
FIG. 4 is a view illustrating the game head transfer device with a game head.
FIG. 5 is a view illustrating the game head transfer device in a closed position with the game head.
FIGS. 6 and 7 are other views illustrating the game head transfer device in the closed position.
DETAILED DESCRIPTION
The present invention generally relates to a cooler for transferring a game head. The cooler will be described herein for the transfer of the game head from a hunting location. It is to be understood, however, that the cooler may also be used for other purposes when the cooler is not transporting the game head, such as cooling and transferring items, such as food and drinks. To better understand the novelty of the cooler of the present invention and the methods of use thereof, reference is hereafter made to the accompanying drawings.
FIGS. 1 and 2 are views illustrating a game head transfer device 100 . Generally, the game head transfer device 100 is used to cool and transfer a game head 150 ( FIG. 4 ). The game head transfer device 100 includes a front portion 105 , side portions 110 , a back portion 115 , a top portion 120 and a closed bottom portion 125 . The portions 105 , 110 , 115 , 120 , 125 have waterproof surfaces and include insulation between the surfaces. In one embodiment, the insulation in portions 105 , 110 , 115 , 120 , 125 is made from foil bubble insulation, PET aluminum bubble insulation, aluminum foam insulation or any other insulation products known in the art. Further, the portions 105 , 110 , 115 , 120 , 125 are made from flexible material which allows the portions 105 , 110 , 115 , 120 , 125 to conform to the items stored within the game head transfer device 100 . The flexible material of the portions 105 , 110 , 115 , 120 , 125 also allows the game head transfer device 100 to collapse into a smaller configuration when the game head transfer device 100 is not in use. In one embodiment, the bottom portion 125 includes reinforcement members that are configured to maintain the shape of the bottom portion 125 and support the game head 150 . As shown, the side portions 110 of the game head transfer device 100 may include buckles 135 that are used to secure the game head transfer device 100 in a closed position. The front portion 105 and the back portion 115 may include handles 190 for use in carrying the game head transfer device 100 .
In one embodiment, the game head transfer device 100 may include an optional side pocket 155 on the front portion 105 for storage. The side pocket 155 may have a closing member, such as a zipper. There may be a similar side pocket 155 on the back portion 115 . An outside surface of the side pocket 155 may be used for attaching a logo, emblem or symbol. In one embodiment, the portions 105 , 110 , 115 , 120 , 125 are made from a thermal material that changes color as the temperature changes within the game head transfer device 100 . In one embodiment, an optional temperature gauge may be disposed within the front portion to indicate the temperature within the game head transfer device 100 .
FIG. 3 is a view illustrating the game head transfer device 100 in an open position. The portions 105 , 110 , 115 , 120 , 125 define a body having a transport area 130 that is configured to hold the game head 150 (or other items). As shown in FIG. 3 , the transport area 130 has an initial predefined shape, such as a square or a rectangle, but any geometric shape may be used without departing from principles of the present invention.
The top portion 120 includes a first side 160 and a second side 165 . Each side 160 , 165 includes a closing member 170 , such as a zipper, which is used to close the transport area 130 . Each side 160 , 165 further includes a closing flap 175 that extends from a point below the closing member 170 to a point in the transport area 130 . In the embodiment illustrated, the closing flap 175 extends substantially along the entire length of the respective side 160 , 165 . Generally, the closing flaps 175 are used to seal or close the top portion 120 of the game head transfer device 100 when the game head 150 is in the transport area 130 , as will be described herein.
The closing flaps 175 have a fixed end that is attached to the top portion 120 and a free end. The free end of the closing flaps 175 are configured to rotate around the fixed end to any number of positions. The free end of the closing flaps 175 include releasable connection members 195 on an inner portion of the respective flap 175 , such as Velcro, that is used to secure the free end of the closing flap 175 on the first side 160 to the free end of the closing flap 175 on the second side 165 . In other words, the releasable connection members 195 are configured to mate with each other to seal or close the top portion 120 of the game head transfer device 100 when the game head 150 is in the transport area 130 . As such, the closing flaps 175 provide a first means for closing or sealing around the game head 150 , and the closing member 170 provides a second means for closing or sealing around the game head 150 . In one embodiment, a connection member (not shown) may be disposed on the inner surface of the portions 105 , 110 , 115 that is configured to engage the releasable connection members 195 to secure the free end of the closing flaps 175 in place when the closing flaps 175 are not in use. The connection members may be any type of connection member known in the art, such as Velcro or clips. Although the game head transfer device 100 in FIG. 3 shows two flaps 175 , any number of flaps 175 may be used without departing from principles of the present invention. In one embodiment, a single flap is used on the first side 160 that has a fixed end and a free end. The single flap has releasable connection members on an inner portion of the free end of the single flap that is configured to engage releasable connection members on the second side 165 .
FIG. 4 is a view illustrating the game head transfer device 100 with the game head 150 . In comparing FIG. 2 and FIG. 4 , the transport area 130 has been reconfigured to accommodate the game head 150 . The flexible material of the portions 105 , 110 , 115 , 120 , 125 allow the transport area 130 to conform to the game head 150 . As shown in FIG. 4 , a portion 140 (e.g., antlers) of the game head 150 extends from the game head transfer device 100 . The portion 140 may include a first portion (e.g., first antler) and a second portion (e.g., second antler). The closing flaps 175 and the closing members 170 are configured to allow the portion 140 of the game head 150 to protrude outside of the game head transfer device 100 , while at the same time closing the top portion 120 to maintain a cool temperature within the game head transfer device 100 . As shown, the closing flaps 175 close the top portion 120 to a point 145 adjacent each outer side of the portion 140 of the game head 150 extending outside of the game head transfer device 100 . The closing flaps 175 may be configured to also close an area 185 between the first portion and the second portion of the game head 150 extending outside of the game head transfer device 100 ( FIG. 6 ). The closing flaps 175 are also configured to stabilize (or hold) the game head 150 in a position within the transport area 130 . The flexibility of the arrangement of the closing flaps 175 allows the game head transfer device 100 to be used for different sized game heads and/or antlers.
The game head transfer device 100 may also include a removable inner liner (not shown) that fits in the transport area 130 . The inner liner may be made from a flexible material and the inner liner may be removed from the game head transfer device 100 for easy clean-up after usage. The game head transfer device 100 may also include pockets inside the transport area 130 for cooling material such as ice.
FIGS. 5-7 are views illustrating the game head transfer device 100 in a closed position. As shown, the closing members 170 have been closed to a point 180 on each side of the portion 140 of the game head 150 that protrudes outside of the game head transfer device 100 . The closing members 170 enclose the closing flaps 175 (and the point 145 ) to add additional closure of the top portion 120 adjacent the sides of the portion 140 . The closing members 170 also provide additional support to maintaining the game head 150 within the transport area 130 . As shown in FIG. 6 , one closing member 170 is disposed on one side of the portion 140 of the game head 150 , and another closing member 170 is disposed on the other side of the portion 140 of the game head 150 . The closing member 170 arrangement allows for both sides of the portion 140 of the game head 150 to be closed. The flexibility of the arrangement of the closing flaps 175 and the closing members 170 allows the game head transfer device 100 to accommodate different sized game heads.
While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow. | The present invention generally relates to a cooler for transferring a game head. In one aspect, a game head transfer device is provided. The device includes a body having an opening on an upper portion that is configured to receive a game head into the body, wherein a first portion and a second portion of the game head extend from the opening of the body when the body is in an opened position and a closed position. The device further includes one or more flap members configured to narrow the opening of the body between the first portion and the second portion of the game head. The device also includes one or more closing members configured to narrow the opening of the body adjacent a side of the first portion and a side of the second portion of the game head that extend from the opening. | 1 |
CROSS REFERENCE TO RELATED APPLICATIONS
The application is a continuation of copending application Ser. No. 515,173, filed on Apr. 26, 1990 now U.S. Pat. No. 5,019,030, entitled, "Envelope Blank Forming Machine" by Herbert W. Helm.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an envelope blank forming machine and more particularly to an envelope blank forming machine for making either generally rectangular booklet type envelope blanks or generally diagonal type envelope blanks.
2. Description of the Prior Art
Machines for making booklet type envelope blanks are known. Other machines for making diagonal envelope blanks are also known. Web attachments for open end blanks as well as booklet blanks are also known.
U.S. Pat. No. 3,954,213 discloses a turnbar apparatus for turning a strip from a web from a horizontal plane to a vertical plane to adjust the entry angle of the strip as it is fed into the blank forming machine. The turnbars are mounted on separate supports and are adjustable relative to each other.
U.S. Pat. No. 2,951,408 discloses apparatus for forming only diamond or diagonal envelope blanks from a strip where the strip is fed to the machine at an angle to the axis of the blank forming machine. A means to adjust the angular relationship of the cutting knives and the shape of the diamond or diagonal blanks is also disclosed. The apparatus of conveying, shaping, driving, supporting and adjusting various components of the machine disclosed in U.S. Pat. No. 2,951,408 is incorporated herein by reference.
There is a need to provide an envelope blank forming machine that uses some of the same components for forming either generally rectangular booklet envelope blanks or generally diagonal envelope blanks. There is also a need to provide means to retract certain components when not required to form a particular envelope blank and to further substitute certain components in the same stations for the production of envelope blanks of a particular configuration.
SUMMARY OF THE INVENTION
This invention relates to an envelope blank forming machine to form either generally rectangular booklet envelope blanks or generally diagonal envelope blanks from a web and includes pull rolls arranged on the machine to pull the strip of paper from the web and feed the strip into the envelope blank forming machine. The pull rolls are positioned in a perpendicular position relative to the axis of the machine to feed the strip axially into the machine when forming booklet envelope blanks. The pull rolls are movable to an angular position relative to the axis of the machine to feed the strip at an angle to the axis of the machine for forming diagonal blanks. A rotatable cutoff knife is positioned in a perpendicular position relative to the axis of the machine and perpendicular to the strip to cut off booklet envelope blanks from the strip having a generally rectangular configuration. The rotatable cutoff knife is movable to an angular position relative to the axis of the machine and the strip to cut the strip diagonally to the strip axis to form a blank having a diagonal configuration. A first removable turnbar is positioned upstream of the pull rolls and is arranged at an angle to the axis of the blank forming machine. The turnbar is arranged to angularly change the direction of the strip from a direction aligned with the axis of the machine to an angular direction. The first turnbar is removed from the machine during the forming of booklet envelope blanks. A second removable turnbar is positioned in spaced relation to the first turnbar and is arranged at an angle to the axis of the blank forming machine. The second turnbar is arranged to control the direction of movement of the strip to the pull rolls so that the strip moves at an angle to the axis of the machine. The second turnbar is removed from the machine during the forming of booklet envelope blanks. Separating rolls are provided and rotate at a peripheral speed greater than the linear speed of the strip and are positioned downstream of the cutoff knife to separate and space the blanks from each other. Retractable rotator trimmer knives are positioned downstream from the separating rolls to trim the pointed ends from a diagonal blank. The rotatable trimmer knives are retracted into an inoperative position when forming rectangular envelope blanks. Seal flap cutters are positioned downstream of the trimmer knives and are arranged to remove portions of the envelope blank and form seal flaps on booklet type envelope blanks and seal flap corners on diagonal blanks. First bottom flap cutters are positioned downstream of the seal flap cutters. The first bottom flap cutters are arranged to remove portions of the envelope blank and form a portion of the bottom flap on both the booklet envelope blank and the diagonal envelope blank. A rotatable second bottom flap cutter is positioned downstream of the first bottom flap cutter. The second bottom flap cutter is arranged to remove other portions of the booklet envelope blank and form a bottom flap on the booklet envelope blank. The rotatable second bottom flap cutters are arranged to remove portions of the diagonal envelope blanks and trim the bottom seal flap edge of the diagonal envelope blank.
The invention further includes a method of forming either a generally rectangular booklet envelope blank or a generally diagonal envelope blank from a web on the same envelope blank forming machine and includes feeding the strip from a web into a pair of pull rolls on the envelope blank forming machine. The pull rolls are positioned perpendicular to the axis of the machine and the strip to form booklet envelope blanks. The pull rolls are positioned at an angular position to the axis of the machine to form diagonal envelope blanks. A pair of removable turnbars are positioned upstream from the pull rolls to change the direction of the strip from a direction aligned with the axis of the machine to a direction at an angle to the axis of the machine when forming diagonal envelope blanks on the machine. The turnbars are removed from the machine when forming booklet envelope blanks so that the strip is fed into the machine along the axis of the machine. A cutoff station is provided downstream of the pull rolls and includes a rotary cutoff knife that is arranged perpendicular to the axis of the strip and cuts the strip to form a blank that has a generally rectangular configuration. The rotary knife is adjusted so that the knife cuts the strip at an angle and forms a blank having a generally diagonal configuration. A separating and spacing station is provided when the envelope blanks cut from the strip are conveyed at a speed greater than the linear speed of the strip. A trim station is provided which includes rotatable trimmer knives to trim the pointed edges from the diagonal envelope blanks. The trimmer knives are retracted when booklet envelope blanks are being formed. The envelope blanks are then conveyed from the trim station to a seal flap forming station. Portions of the envelope blank are removed in the seal flap forming station to form seal flaps on rectangular booklet envelope blanks and seal flap corners on diagonal envelope blanks. The envelope blanks are conveyed from the seal flap forming station to a first bottom flap forming station where portions of the envelope blank are removed in the first forming station to form a portion of the bottom flap of a booklet envelope blank and forming a corner on the bottom flap of a diagonal envelope blank. The envelope blanks are then conveyed from the first bottom flap forming station to a second bottom flap forming station where portions of the envelope blank are removed and form a bottom flap on a booklet envelope blank and trim a portion of the diagonal envelope blank.
It will be apparent with the above invention that it is now possible to quickly and simply convert one envelope blank forming machine to another so that either generally rectangular envelope blanks or generally diagonal envelope blanks may be formed from a web by the same machine.
It is an object of this invention to provide an envelope blank forming machine where different types of envelope blanks may be formed.
Another object of this invention is to provide an envelope blank forming machine where components are interchangeable for use in forming two different types of envelope blanks.
These and other objects of the present invention will be more completely disclosed and described in the following specification, the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic representation of an envelope blank forming machine arranged to form generally rectangular booklet envelope blanks.
FIG. 2 is a diagrammatic representation of the sequential shapes of the booklet type envelope blank while it is being formed in the blank forming machine.
FIG. 3 is a diagrammatic view of the same envelope blank forming machine modified to form generally diagonal envelope blanks.
FIG. 4 is a view similar to FIG. 2 of the sequential shapes of the diagonal envelope blank as it is formed in the envelope blank forming machine illustrated in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 3, the envelope blank forming machine is generally designated by the numeral 10 and the various components are diagrammatically illustrated. The envelope blank forming machine in FIG. 3 is arranged to form generally diagonal envelope blanks and is illustrated as having a first side frame 12 and a second side frame 14. The side frames 12 and 14 are segmented and are arranged to rotatably support the respective, hereinafter described, components and suitable gearing (not shown) is arranged to rotate the components in timed relation to each other.
A web of paper (not shown) has a strip 16 unwound therefrom and is fed into the machine 10. The strip passes between rolls 18 and 20 rotatably journaled in the frame side walls 12 and 14. A first turn bar 22 is rotatably supported by the frame members 12 and 14 at an angle to the axis A of the strip 16 and the strip 16 passes around the angularly positioned turnbar and moves around the turnbar 22 as designated by the numeral 24. Because of the angular position of the turnbars 22 and 26, the axis of the strip is angularly displaced from axis A of the strip 16 entering the machine 10. The turnbars 22 and 26 may be displaced horizontally or vertically. The turnbars 22 and 26 are displaced generally horizontally. The web strip section 24 extends around a second turnbar 26 which directs the strip of material at an angle to the longitudinal axis of the machine 10 that is parallel to the frame sections 12 and 14. The angularly extending section 28 of the strip passes between a pair of pull rolls 30 which frictionally engage the angularly extending portion of strip 28 to pull the strip from the web and feed the strip to the envelope blank forming machine 10.
A rotatable cutoff roll 32 is positioned down stream of the pull roll 30 and is arranged to cut preselected lengths of paper from the strip 16. The cutoff knife 32 has a suitable backing member 34 such as an anvil to facilitate a sharp cut in the strip portion 28. The pull rolls, turnbars and cutoff mechanisms are conventional and well known in the art.
Because of the angular relation between the rotary cutoff knife 32 and the axis of the strip 16, the strip is cut diagonally to form a diamond shaped blank 36. The front and rear edges of the diamond shaped blank are formed from the body of the strip while the side edges of the diamond shaped blank 36 are formed from the existing side edges of the strip. A plurality of pull away conveying rolls 40 are arranged to separate the diamond shaped blanks and convey the blanks 36 in spaced relation along the axis of the envelope blank forming machine indicated by the ----.----line and identified by the letter B.
Rotatable edge trimmer knives 42 are rotatably journaled in the frames 12 and 14 and are arranged upon rotation to trim the pointed edges 44 from the diamond shaped blank 36. The configuration of trimmed diamond shaped blank is illustrated in FIG. 4 on the extreme left which is the first diagrammatic representation of the diagonal envelope blank as it is formed in the forming machine 10.
The generally diagonally shaped envelope blank is then conveyed by suitable rolls through a printer feeder portion of the machine generally designated by the numeral 46. It should be noted that the previously described portion of the envelope blank forming machine is positioned at a higher elevation than the printer feeder 46 so that the partially formed envelope blanks may be introduced into the upper portion of the printer feeder and conveyed therethrough.
The partially formed generally diagonal envelope blank 36 with the edges 44 trimmed by the trimming knives 42 is then introduced into the blank forming section 48 from the printer feeder 46. The blank 36 is conveyed by means of suitable rolls into a seal flap corner cutter device 50 that includes a pair of cutter rolls which cut and remove the shaded portion 52 illustrated in FIG. 4. After the seal flap corners 52 are removed from the blank 36, the blank is conveyed to a bottom flap corner cutter 54 which has a pair of rotating cutter devices arranged to remove the shaded section 56 illustrated in FIG. 4. With this arrangement, the seal flap corners are removed at the station generally designated by the numeral 50 and the bottom flap corners are removed at the station generally designated by the numeral 54.
The blank 36 with the seal flap and bottom flap formed therein is then conveyed to a trimming station 58 where the sharp edges indicated by the numeral 60 are trimmed from the blank 36 to form rounded edges as illustrated in the blank 36 at the extreme right end of FIG. 4 and illustrated on the transfer drum 62. The generally diagonal envelope blank is then fed into the envelope making machine where the blank is folded and suitable adhesive applied thereto.
Referring to FIGS. 1 and 2, the envelope blank forming machine generally designated by the numeral 10 is modified to form generally rectangular envelope blanks by removing certain of the essential components required for the generally diagonal envelope and substituting various other cutters for the seal flaps and bottom flaps of the generally rectangular booklet envelope blank. Referring to FIGS. 1 and 2, a strip of paper 100 is unwound from a web (not shown) by a pair of pull rolls 102 which have the strip extending therebetween. The pull rolls 102 frictionally engage and exert a tension on the strip 100. The axis of the strip 100 is generally designated by the ----.---- line designated by the letter C and it should be noted that the strip and the blanks severed thereform remain on the same axis C which is the same as the axis of the envelope blank forming machine. There are no angular or lateral deviations from this axis during the formation of the generally rectangular booklet type envelope blank. The rotatable cutoff knife 104 and the backing anvil 106 are the same as the cutoff knives 32 and 34, previously described. However, in the booklet embodiment illustrated in FIG. 1, the knife 104 and anvil 106 at the cutoff station are perpendicular to the axis C of the strip 100. The knife 104 severs rectangular segments 108 from the strip 100. Pull away or separator rolls 110, which are the same as previously described rolls 40, are arranged to separate the severed segments 108. The segments 108 have a generally rectangular configuration as illustrated in the left end segment 108 illustrated in FIG. 2. The segments 108 are conveyed through the printer feeder mechanism generally designated by the numeral 111 and diagrammatically illustrated by a plurality of rolls. The printer feeder mechanism 111 is the same as the printing mechanism 46 illustrated in FIG. 3.
The blank 108 is conveyed from the printer feeder 111 by means of rolls to the seal flap cutters generally designated by the numeral 112. The seal flap cutters 112 are arranged to cut the edges 114 illustrated as shaded areas in FIG. 2 from the rectangular blank 108 and form a seal flap on the envelope blank 108. The frame structure of the envelope blank forming machine is such that the seal flap cutters 112 may be easily changed from that for a booklet type of envelope blank to a diagonal type of envelope blank.
The blank 108 is then conveyed to bottom flap first cutter rolls generally designated by the numeral 116 which cuts the portions 118 in the blank 108 as illustrated in FIG. 2. The envelope blank 108 is then conveyed to bottom flap final cutter rolls generally designated by the numeral 120 which cut and remove the shaded portions 122 illustrated in FIG. 2. Thus a generally rectangular booklet envelope blank 124, illustrated in FIG. 1, on the transfer drum 126 in the envelope blank forming machine and on the right end of FIG. 2 is formed.
It should be understood that the envelope blank forming machine may be quickly converted from a machine that forms generally rectangular booklet envelope blanks to a machine that forms generally diagonal envelope blanks. For the booklet type envelope blanks, the turnbars 22 and 26 are removed and the feeder rolls 102 and cutoff knife 104 and anvil 106 are positioned perpendicular to the axis of the strip to form generally rectangular envelope blanks 108. The generally rectangular envelope blanks are then conveyed to a seal flap cutter station where suitable roller type seal flap cutters 112 are positioned in the machine to cut segments 114 from the envelope blank and form the seal flap. The blank is thereafter conveyed to a first bottom flap cutter station where suitable cutters 116 cut the portions 118 in the envelope blank and finally the envelope blank is conveyed to the final bottom flap cutter where the rolls 120 cut the portions 122 of the blank to form a bottom flap.
To convert the booklet machine to a diagonal machine, the turnbars 22 and 26 are positioned in the machine and the pull rolls and cutoff knives are positioned angularly to the axis of the strip. It should be noted that the knives 32 and 34 at the cutoff station may be adjusted to adjust the diagonal angle on the envelope blank. Trimmers, which are retracted when booklet envelope blanks are formed, are extended to cut off the corner edges of the generally diagonal envelope blank. The cutters for the seal flap and bottom flap are changed from those utilized with the booklet to remove the sections 56 illustrated in FIG. 4. Finally the booklet bottom flap cutter is removed and diagonal trim cutters are substituted therefor.
It will be apparent from the above arrangement that it is now possible to rapidly convert an envelope blank forming machine from a machine that makes generally rectangular booklet envelope blanks to a machine that makes generally diagonal envelope blanks.
According to the provisions of the Patent Statutes, we have explained the principle, preferred construction and mode of operation of our invention and have illustrated and described what we now consider to represent its best embodiments. However, it should be understood that, within the scope of the appended claims, the invention may be practiced otherwise than as specifically illustrated and described herein. | An envelope blank forming machine for forming generally rectangular booklet envelope blanks and generally diagonal envelope blanks on the same machine includes a pair of removable turnbars, adjustable pull rolls and an adjustable cutoff device. Preselected adjustment of these components provides a generally rectangular blank or a generally diagonally shaped blank. Retractable trim devices are provided in cutting relation with the blank when diagonal blanks are being formed. Seal flap cutters and first and second flap cutters are provided to form the booklet seal flap and bottom flap on the booklet envelope blank. These cutters are removed and replaced with seal flap corner cutters, bottom flap corner cutters and diagonal trim cutters when generally diagonal envelope blanks are being formed. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method for suturing by inserting a suture instrument via the mouth or the anus. For example, the present invention relates to a method of suturing a perforation formed in a wall of a hollow organ.
2. Description of Related Art
In the case of performing treatment in a body of a patient, the treatment can be performed by incising the body of the patient by surgical operation, or by oral endoscopic treatment or transanal endoscopic treatment. A method for suturing a perforation formed in an abdominal area by surgical operation is disclosed in FIGS. 6a to 6c of U.S. Pat. No. 6,066,146. According to this suturing method, a needle is thrust into the tissue around the perforation, and an anchor equipped with a suture thread is then extruded from the needle. After the needle is drawn out from the tissue, two suture threads across the perforation are knotted together to close the perforation.
The treatment using an endoscope is carried out by passing a forceps, high-frequency treatment instrument, incision instrument, suture instrument or the like through a channel of the endoscope. When the medical treatment is carried out by using an endoscope inserted into a lumen through a natural opening of a living body such as the mouth, anus, or the like, for example, a hole is formed by removing the tissue from the abdominal cavity or incising the tissue in the abdominal cavity, and the medical treatment is then carried out by approaching the abdominal cavity through this hole from the inside of the lumen. After performing the medical treatment, the formed hole is sutured by a suture instrument.
A method for suturing in a hollow organ is disclosed in FIGS. 6 to 9 of Japanese Laid-Open Patent Application No. 2004-601, for example. According to this suturing method, the tissue is drawn into an overtube, and a needle is then thrust through this tissue from the proximal side to the distal side thereof. From the inside of the needle, an anchor equipped with a suture thread is pushed out to the distal side of the tissue. After that, the needle is pulled out, and thereby the suture thread penetrates through the tissue and tightens up the tissue. There is also a method disclosed in FIG. 1, FIG. 4, FIGS. 5A to 5C of U.S. Pat. No. 5,297,536. According to this method, a flexible endoscope is inserted into the vicinity of a perforation via the mouth or the anus. The tissue around the perforation is aspirated by a tube of the flexible endoscope. When an O-ring provided at the outside of the tube is pushed out from the tip of the tube, the aspirated tissue is clamped by the O-ring.
SUMMARY OF THE INVENTION
A method for suturing a perforation of the present invention comprises the steps of: observing an area around the perforation from an inside of a hollow organ by an observation device inserted from a natural opening of a living body; observing the area around the perforation from a body cavity side of the hollow organ by an observation device inserted from the natural opening of the living body; thrusting a needle of a suture unit inserted from the natural opening of the living body into a tissue around the perforation of the hollow organ to make a suture thread puncture the tissue via the needle; and closing the perforation by tightening up the suture thread puncturing the tissue.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view showing a schematic constitution of an endoscope and a suture unit.
FIG. 2 is a cross-sectional view of a suture unit and an end portion of an endoscope.
FIG. 3 is a perspective view of a suture unit and an end portion of an endoscope.
FIG. 4 is a view showing a constitution of a suture instrument.
FIG. 5 is a schematic view showing a step of inserting an endoscope into the stomach of a patient to observe a perforation from the inside of the stomach.
FIG. 6 is a schematic view showing a step of observing the outside of the stomach.
FIG. 7 is a schematic view showing a step of puncturing the tissue with a needle of a suture unit.
FIG. 8 is a schematic view showing a step of putting an anchor out from a needle to the outside of the stomach.
FIG. 9 is a schematic view in which two anchors are placed outside the stomach.
FIG. 10 is a schematic view showing a step of tightening up a perforation by a suture instrument.
FIG. 11 is a schematic view showing manipulation for grasping a suture instrument gripped by a forceps.
FIG. 12 is a view in which a perforation is sutured by a forceps and a suture instrument.
FIG. 13 is a schematic view showing a rod which is an example of a retracting instrument.
FIG. 14 is a schematic view showing a balloon catheter which is an example of a retracting instrument.
FIG. 15 is a schematic view showing a balloon catheter in which a balloon is inflated.
FIG. 16 is a schematic view showing a forceps which is an example of a retracting instrument.
FIG. 17 is a schematic view showing one example of combination of an endoscope with a suture unit.
FIG. 18 is a schematic view showing one example of combination of an endoscope with a suture unit.
FIG. 19 is a schematic view showing one example of combination of an endoscope using an overtube with a suture unit.
FIG. 20 is a schematic view showing one example of combination of an endoscope with an observation device.
FIG. 21 is a schematic view showing one example of combination of an endoscope with a suture unit.
FIG. 22 is a schematic view showing one example of combination of an endoscope using an overtube with a suture unit.
FIG. 23 is a schematic view showing a step of observing the outside of the stomach.
FIG. 24 is a schematic view showing a step of puncturing the tissue from the outside of the stomach with a needle of a suture unit.
FIG. 25 is a schematic view showing a step of pushing out an anchor from a needle to the inside of the stomach.
FIG. 26 is a schematic view in which two anchors are placed on the inside of the stomach.
FIG. 27 is a schematic view showing a step of tightening up a perforation with a suture instrument.
FIG. 28 is a schematic view showing manipulation for grasping a suture instrument by a forceps.
FIG. 29 is a view in which a perforation is sutured by a forceps and a suture instrument.
FIG. 30 is a schematic view showing a step of observing the outside of the stomach.
FIG. 31 is a schematic view showing a step of puncturing the tissue with a needle of a suture unit.
FIG. 32 is a schematic view showing a step of pushing out an anchor from a needle to the inside of the stomach.
FIG. 33 is a schematic view in which two anchors are placed on the inside of the stomach.
FIG. 34 is a schematic view showing a step of tightening up a perforation with a suture instrument.
FIG. 35 is a schematic view showing a step of thrusting a needle from the inside of the stomach after observing the inside and the outside of the stomach by an endoscope.
FIG. 36 is a schematic view showing one example of combination of an endoscope with a suture unit.
FIG. 37 is a view showing the order for tightening up plural suture instruments.
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment
In FIG. 1 , an endoscope and a suture unit used in this embodiment are shown. An endoscope 1 (flexible endoscope) has an endoscope operation unit 2 which is operated by an operator. The endoscope operation unit 2 is connected to a control device via a universal cable 3 and equipped with various switches 4 and angle knobs 5 . At the tip of the endoscope operation unit 2 , an endoscope insertion part 6 that is flexible and long is extendedly formed. At the tip of the endoscope insertion part 6 , an observation device (first observation device, hereinafter, merely referred to as observation device) 7 for an endoscope which obtains an image of the internal body, a lighting unit 8 , and a tip opening of a channel 9 are provided. As the observation device 7 , an imaging device having a CCD (Charge Coupled Device) or an optical fiber can be used. The lighting unit 8 has an optical fiber that conducts light from a light source. The channel 9 opens at a lateral part 2 a of the endoscope operation unit 2 through the endoscope insertion part 6 . At an opening of the lateral part 2 a , a cap 10 is provided. In the cap 10 , an insertion hole is formed, and a treatment tool such as a suture unit 11 or the observation device is inserted into the channel 9 through this insertion hole.
As shown in FIGS. 1 to 3 , in the suture unit 11 , a flexible inner sheath 13 is passed through the inside of a flexible outer sheath 12 so as to be able to freely move forward or backward. To the tip of the inner sheath 13 , a needle 14 is fixed. The needle 14 has a slit 15 formed in a longitudinal direction from the tip thereof. A suture instrument 16 is contained inside of the needle 14 . Each of the lengths of the outer sheath 12 and the inner sheath 13 is longer than that of the channel 9 of the endoscope 1 . At a proximal end of the inner sheath 13 , an operation unit 17 is provided. The operation unit 17 has a handle 19 which can freely slide with respect to a main body 18 of the operation unit. To the handle 19 , a proximal end of a pusher 20 is fixed. The pusher 20 extends through the inside of the inner sheath 13 to the inside of the needle 14 . A distal end portion 21 of the pusher 20 is pressed against the suture instrument 16 .
As shown in FIG. 4 , the suture instrument 16 has a suture thread 25 . The suture thread 25 is folded approximately in two and a knot 31 is formed in the vicinity of its turn-around point. Moreover, the suture thread 25 is bundled at both end portions thereof and passed through a stopper 26 that is substantially triangular. To each end portion of the suture thread 25 , an anchor 27 is fixed. The anchor 27 has a cylindrical shape and the suture thread 25 is fixed at an approximately center portion in a longitudinal direction of the anchor 27 . The stopper 26 includes a long, thin plate member in which a hole 28 is formed at the center portion in a longitudinal direction thereof, through which the suture thread 25 is passed. Both end portions 29 in a longitudinal direction of the stopper 26 are diagonally folded back to hold the suture thread 25 therebetween. Both end portions 29 in a longitudinal direction of the stopper 26 are cut to form triangular sections 30 . Both end portions 29 of the stopper 26 are diagonally folded back so that the sections 30 intersect with each other to hold the suture thread 25 therebetween. As a result, the suture thread 25 is prevented from passing through a space formed between end portions 29 . When the knot 31 of the suture thread 25 is pulled in a direction away from the stopper 26 , both end portions 29 of the stopper 26 are slightly opened. Accordingly, the stopper 26 allows the suture thread 25 to move in the same direction. On the other hand, when end portions of the suture thread 25 at the side of the anchors 27 are pulled, the suture thread 25 is ready to move in a direction shown by an arrow in FIG. 4 . However, both end portions 29 of the stopper 26 close and secure the suture thread 25 at this time, and thereby the suture thread 25 does not move.
As shown in FIG. 3 , the suture instrument 16 sequentially holds two anchors 27 in an inner hole of the needle 14 . The suture thread 25 is drawn out from the slit 15 of the needle 14 . As shown in FIG. 2 , the stopper 26 is held at a more distal end portion than the needle 14 in the outer sheath 12 . The number of the anchors 27 and the shape of the stopper 26 are not limited to the embodiment shown in the figures.
Next, a suturing method of this embodiment will be explained mainly with reference to FIGS. 5 to 12 . FIGS. 5 to 12 are pattern diagrams illustrating manipulation and show the stomach as an example of a hollow organ.
As shown in FIG. 5 , the endoscope insertion part 6 is inserted from the mouth (a natural opening of a living body, such as the anus, nose, or ear) of a patient 41 prepared with a mouthpiece 40 . When the tip of the endoscope insertion part 6 is bent by the angle knob 5 , a perforation 42 can be checked by the observation device 7 from the inside of the stomach 43 (the inside of the hollow organ). As shown in FIG. 6 , an observation device (second observation device) 50 is passed through the channel 9 of the endoscope 1 . The observation device 50 is, for example, a catheter having a camera at the tip thereof. The observation device 50 may be a long and narrow fiberscope.
The tip of the observation device 50 is inserted from the perforation 42 into the abdominal cavity 44 , and the tip of the observation device 50 is then bent back by a wire or the like, which is not shown in the figures. By using the observation device 50 , an area around the perforation 42 to be punctured with the needle 14 (referred also to as a puncture position or a position through which the needle 14 passes) is observed from an abdominal cavity 44 side (which is also the side at which the anchor 27 is placed), that is, from the outside of the stomach 43 (referred also as a body cavity side of the hollow organ or the abdominal cavity side) to check that other tissues such as the small intestine, the liver, or the like do not exist at the position through which the needle 14 is passed in order to prevent these tissues from being punctured or sutured together.
As shown in FIG. 7 , the suture unit 11 is projected to puncture the tissue around the perforation 42 with the needle 14 while observing the stomach 43 from the abdominal cavity 44 side by the observation device 50 . When the tissue is punctured, the needle 14 is projected from the outer sheath 12 as shown in FIG. 3 . The stopper 26 which is contained at the more distal end portion than the needle 14 is extruded from the outer sheath 12 into the stomach 43 when projecting the needle 14 . When the needle 14 is moved forward with the outer sheath 12 fixed, the needle 14 punctures the tissue. When the handle 19 provided at an operator-side as shown in FIG. 1 is pushed in, the pusher 20 moves forward, and the first anchor 27 is pushed out from the tip of the needle 14 into the abdominal cavity 44 , as shown in FIG. 8 . When the first anchor 27 is pushed out, the pusher 20 is stopped, and the needle 14 is drawn out from the tissue. The first anchor 27 remains on the abdominal cavity 44 side. The suture thread 25 penetrates through the tissue. The stopper 26 is then in the stomach 43 .
Moreover, the needle 14 is thrust again at an approximately symmetrical position with respect to the position at which the needle 14 is previously thrust centered about the perforation. In the same manner as when using the first anchor 27 , when the needle 14 penetrates through the tissue, the pusher 20 is moved forward. The second anchor 27 is pushed out into the abdominal cavity 44 . As shown in FIG. 9 , when the needle 14 is drawn back, the second anchor 27 remains on the abdominal cavity 44 side, the suture thread 25 penetrates through the tissue, and two anchors 27 are placed on the abdominal cavity 44 side to sandwich the perforation 42 therebetween.
Next, as shown in FIG. 10 , after the observation device 50 is drawn back to the inside of the stomach 43 , the suture thread 25 is pulled so that the anchor 27 and the stopper 26 tighten up the tissue, and thereby the perforation 42 is sutured. When the suture thread 25 is pulled, a forceps 60 shown in FIG. 11 , for example, is used. The forceps 60 is passed through the channel 9 in the place of the observation device 50 . The forceps 60 has an outer sheath 61 having an external diameter larger than the anchor 27 and an inner sheath 62 passed through the outer sheath 61 so as to freely move forward or backward. At the tip of the inner sheath 62 , a supporting member 63 is provided, and a pair of grip segments 64 are supported on the supporting member 63 so as to freely open or close.
After the knot 31 of the suture thread 25 of the suture instrument 16 is gripped by the grip segments 64 , the outer sheath 61 is moved forward to press the tip of the outer sheath 61 against the stopper 26 . As shown in FIG. 12 , when the outer sheath 61 moves further forward, the stopper 26 is pushed into the wall of the stomach 43 . Since the stopper 26 is constructed to be able to move in this direction, the stopper 26 moves toward the wall. Since the position of the pair of the grip segments 64 does not change, the stopper 26 moves relatively forward with respect to the suture thread 25 . As a result, the distance between the stopper 26 and the anchor 27 decreases. This pulls together the tissue around the perforation 42 , and the perforation 42 is sutured by the suture thread 25 . After suturing the perforation 42 by the suture instrument 16 , the outer sheath 61 is moved backward, and the grip segments 64 are then opened to release the suture thread 25 . Although the tip of the stopper 26 can move in a direction in which the tissue is tightened up by the suture thread 25 , it acts to tighten up the suture thread 25 in a direction for loosening the suture thread 25 . As a result, the suture thread 25 is not loosened, even if the suture instrument 16 is placed inside of the stomach 43 .
When a hollow organ such as the small intestine or the colon or another organ such as the spleen or the liver (hereinafter, merely referred to as tissue) exists in the area around the perforation 42 (the position through which the needle 14 is passed), the other tissue is pulled away from the stomach 43 by inserting a retracting instrument. The retracting instrument used in this case is exemplified in FIGS. 13 to 16 . A retracting instrument shown in FIG. 13 is a rod 70 of which a tip portion can be bent. When the rod 70 is bent, the other hollow organ is pushed off to form a space through which the needle 14 is passed. A retracting instrument shown in FIGS. 14 and 15 is a balloon catheter 71 . When a balloon 73 provided at the tip portion of a catheter 72 is inflated by supplying a fluid from the operator-side to push off the other hollow organ, the space through which the needle 14 is passed is formed. A retracting instrument shown in FIG. 16 is a forceps 74 . When the other hollow organ is grasped by the forceps 74 to draw it away from the stomach 43 , the space through which the needle 14 is passed is formed. At the tip portions of these retracting instruments, an optical fiber or an observation device having a CCD may be provided. When the observation device is provided, it becomes possible to retract other tissues while observing the state of the abdominal cavity 44 .
In this embodiment, the perforation 42 is observed from the inside of the stomach 43 by the observation device 7 of the endoscope 1 at first, and the perforation 42 is then observed from the abdominal cavity 44 side by the observation device 50 . After that, the suture unit 11 is made to penetrate through the tissue around the perforation 42 to mount the suture instrument 16 , and the perforation 42 is sutured by using this suture instrument 16 . Accordingly, it is possible to suture the perforation 42 after respectively checking from the inside (the side from which the needle 14 is thrust) and the outside (the side through which the needle 14 penetrates or at which the anchor 27 is placed) of the stomach 43 that another tissue does not exist around the perforation 42 . According to a suturing method using an endoscope of the prior art, it is impossible to check the opposite side. According to the endoscopic suturing method in this embodiment, it is possible to easily and certainly check for the existence of other tissues, as a result of which manipulation can be carried out with rapidity.
Modified examples of this embodiment are shown in FIGS. 17 to 22 .
As shown in FIG. 17 , two external sheaths 80 are provided at the periphery of the endoscope insertion part 6 . A suture unit 11 is passed through each external sheath 80 so as to freely move forward or backward. The anchors 27 are individually contained in the respective needles 14 . It is possible to thrust two needles 14 into the tissue at the same time or in an arbitrary order. As another example, one external sheath 80 may be used, and two anchors 27 may be contained in one needle 14 . Moreover, FIG. 18 shows an example in which the suture units 11 are individually passed through two channels 9 of the endoscope insertion part 6 .
As shown in FIG. 19 , the endoscope insertion part 6 is inserted into an overtube 81 . At the inner periphery of the overtube 81 , a lumen 82 is provided, and the suture unit 11 is passed through the lumen 82 . At the inner periphery of the overtube 81 , two lumens 82 may be provided, and the suture units 11 may be individually passed through each of the lumens 82 .
As shown in FIG. 20 , a channel 84 may be provided at the periphery of the endoscope insertion part 6 , and the observation device 50 may be passed through this channel 84 . Moreover, the observation device 50 may be directly provided at the periphery of the endoscope insertion part 6 without using the channel 84 .
As shown in FIG. 21 , an external channel 85 may be provided parallel to the endoscope insertion part 6 , and the suture unit 11 may be passed through the channel 85 . The tip portion of this channel 85 can be bent. When observing the perforation 42 from the abdominal cavity 44 side as shown in FIG. 6 , the endoscope insertion part 6 is passed through the perforation 42 and moved into the abdominal cavity 44 , and the tip portion of the endoscope insertion part 6 is then bent to observe by the observation device 7 provided at the tip portion thereof.
As shown in FIG. 22 , the suture unit 11 may be passed through the lumen 82 formed inside of the overtube 81 . In this case, the area around the perforation 42 is observed from the abdominal cavity 44 side by using the observation device 7 of the endoscope insertion part 6 .
Second Embodiment
In this embodiment, the same endoscope 1 and suture unit 11 as in the first embodiment are used. Descriptions that overlap with the first embodiment will be omitted.
A suturing method of this embodiment will be explained. As shown in FIG. 5 , the endoscope insertion part 6 is inserted into the vicinity of the perforation 42 to observe the perforation 42 from the inside of the stomach 43 . Next, as shown in FIG. 23 , the endoscope insertion part 6 is moved from the perforation 42 into the abdominal cavity 44 , and an area around the perforation 42 is then observed from the abdominal cavity 44 side by the observation device (first observation device) 7 of the endoscope insertion part 6 . After confirming that other hollow organs do not exist in the area around the perforation 42 , the needle 14 of the suture unit 11 is projected from the endoscope insertion part 6 as shown in FIG. 24 , and the needle 14 is thrust from the abdominal cavity 44 side into the stomach 43 . Since the safety of the inside of the stomach 43 is confirmed first, the inside of the stomach 43 may not be checked when thrusting the needle 14 . The inside of the stomach 43 , however, may be punctured while observing the inside of the stomach 43 (the side at which the anchor 27 is placed) by using another observation device. In this case, it is possible to puncture at the puncture position while observing both the inside and the abdominal cavity 44 side of the stomach 43 .
As shown in FIG. 25 , the first anchor 27 is extruded into the stomach 43 from the tip of the needle 14 . As shown in FIG. 26 , after placing two anchors 27 so as to sandwich the perforation 42 therebetween, the suture unit 11 is contained inside of the channel 9 . After that, the endoscope 1 is drawn back to the inside of the stomach 43 .
As shown in FIGS. 27 and 28 , the forceps 60 is passed through the channel 9 of the endoscope 1 drawn back to the inside of the stomach 43 . The forceps 60 grasps the knot 31 of the suture thread 25 existing in the abdominal cavity 44 side, and draws the suture thread 25 and the stopper 26 into the stomach 43 through the perforation 42 . As shown in FIG. 29 , when the stopper 26 is pressed against the tissue by the outer sheath 61 , the suture instrument 16 tightens up the tissue, and thereby the perforation 42 is sutured.
In this embodiment, after observation of the inside of the stomach 43 by using the endoscope 1 , the endoscope 1 is moved to the outside of the stomach 43 to check from the abdominal cavity 44 side that other tissues do not exist in the area around the perforation 42 . After that, the needle 14 is thrust into the tissue from the outside to mount the suture instrument 16 and suture the perforation 42 while passing the endoscope 1 through the perforation 42 . Accordingly, other tissues can be easily prevented from being sutured together when suturing by using the endoscope 1 .
Third Embodiment
In this embodiment, the same endoscope 1 and suture unit 11 as in the first embodiment are used. Descriptions that overlap with the first embodiment will be omitted.
A suturing method of this embodiment will be explained. As shown in FIG. 5 , the endoscope insertion part 6 is inserted in the vicinity of the perforation 42 to observe the perforation 42 from the inside of the stomach 43 . Next, as shown in FIG. 23 , the endoscope insertion part 6 is moved from the perforation 42 into the abdominal cavity 44 , and an area around the perforation 42 is then observed from the abdominal cavity 44 side by the observation device (first observation device) 7 of the endoscope insertion part 6 . After checking that other tissues do not exist in the area around the perforation 42 (the position through which the needle 14 is passed, the puncture position, or the position at which the anchor 27 is placed), the endoscope insertion part 6 is drawn back to the inside of the stomach 43 . Next, the suture unit 11 which is passed through the channel 9 is projected. As shown in FIG. 30 , the tip portion of the suture unit 11 is moved from the perforation 42 to the abdominal cavity 44 . The tip portion of the suture unit 11 is then bent to face the outside of the stomach 43 and an area around the perforation 42 in the abdominal cavity 44 .
As shown in FIG. 31 , the suture unit 11 projects the needle 14 from the outer sheath 12 , and the needle 14 penetrates the tissue around the perforation 42 from the abdominal cavity 44 side into the stomach 43 . It is preferable that the stopper 26 be made to enter the stomach 43 when the needle 14 is projected from the outer sheath 12 . As shown in FIG. 32 , after the needle 14 penetrates the tissue, the first anchor 27 is pushed out and placed inside of the stomach 43 . As shown in FIG. 33 , after placement of two anchors 27 inside the stomach 43 so as to sandwich the perforation 42 therebetween, the suture unit 11 is drawn back to the inside of the stomach 43 , and contained in the channel 9 . As shown in FIG. 34 , the forceps 60 is then passed through the channel 9 , and the tissue is tightened up by the suture instrument 16 using the forceps 60 to suture the perforation 42 . The suturing method is the same as in the second embodiment.
In this embodiment, after the inside and the outside of the stomach 43 are sequentially observed by the observation device 7 of the endoscope 1 to check that other tissues do not exist in an area around the perforation 42 , the endoscope 1 is drawn back to the inside of the stomach 43 , and the tissue is punctured with the needle 14 from the outside of the stomach 43 . Accordingly, other tissues can be easily prevented from being sutured together when suturing by using the endoscope 1 .
Next, modified examples of this embodiment will be explained. As shown in FIG. 23 , after observing the outside of the stomach 43 by using the observation device 7 of the endoscope insertion part 6 , the endoscope insertion part 6 is drawn back to the inside of the stomach 43 . After that, the suture unit 11 is projected from the endoscope insertion part 6 present in the stomach 43 , and the needle 14 is thrust from the inside into the outside of the stomach 43 , as shown in FIG. 35 . After placement of the anchor 27 at the outside of the stomach 43 , the suture instrument 16 is tightened up to suture the perforation 42 , as shown in FIGS. 11 and 12 . In this case, other tissues can be easily prevented from being sutured together when suturing by using the endoscope 1 .
As shown in FIG. 36 , a channel 91 may be provided at the periphery of the endoscope insertion part 6 , and the suture unit 11 may be passed through this channel 91 . Moreover, the suture unit 11 may be provided parallel to the periphery of the endoscope insertion part 6 . The tip portion of the suture unit 11 is constructed so as to be able to be independently bent.
This invention can be widely applied without being limited to the above-mentioned embodiments.
For example, the endoscope 1 may be inserted from the anus into the colon which is an example of a hollow organ. In this case, a perforation formed in the colon is sutured. Although the perforation 42 is described as being already formed, the manipulation of the above-mentioned embodiment may be carried out after forming the perforation 42 by using the endoscope 1 . In this case, the endoscope 1 is inserted from a natural opening into the inside of the stomach 43 , and a determined incision portion is checked by the observation device 7 provided at the tip of the endoscope insertion part 6 . After that, the determined incision portion is incised after passing a high-frequency knife or the like through the channel 9 of the endoscope 1 to form the perforation 42 .
When the stomach 43 is widely incised and the perforation 42 is sutured by using at least three suture instruments 16 , suture instruments 16 plurally lined up are preferably sequentially tightened up from one end thereof. In an example shown in FIG. 35 , a suture instrument 16 a , a suture instrument 16 b , a suture instrument 16 c , a suture instrument 16 d , and a suture instrument 16 e are tightened up in this order, for example. Since the perforation 42 is sutured from one end thereof, and the size of the perforation 42 can be gradually diminished, suturing can be easily carried out. Alternatively, the suture instrument 16 at the center of the suture instruments 16 lined up may be tightened up first, followed by tightening the suture instruments 16 at the center positions between the suture instrument 16 tightened up at the center position and the suture instruments 16 at the ends thereof. In the example shown in FIG. 37 , the suture instrument 16 c is tightened up first, the suture instrument 16 b and the suture instrument 16 d are then tightened up, and the suture instrument 16 a and the suture instrument 16 e are finally tightened up. Since the center position of the opening is always sutured, the degree of slippage of suture positions can be diminished. | A method for suturing a perforation comprises the steps of: observing an area around the perforation from an inside of a hollow organ by an observation device inserted from a natural opening of a living body; observing the area around the perforation from a body cavity side of the hollow organ by an observation device inserted from the natural opening of the living body; thrusting a needle of a suture unit inserted from the natural opening of the living body into a tissue around the perforation of the hollow organ to make a suture thread puncture the tissue via the needle; and closing the perforation by tightening up the suture thread puncturing the tissue. | 0 |
TECHNICAL FIELD
The invention relates to a gas bag module for a vehicle occupant restraint device, comprising a gas bag and a discharge arrangement to expose and/or alter a discharge opening through which gas can escape from the gas bag.
BACKGROUND OF THE INVENTION
Such a gas bag module in which a discharge region can be opened in the gas bag wall when a reduction to the internal pressure of the gas bag is required, is known for example from WO-A-2004/045919. A pyrotechnic charge in the form of a fuse is arranged directly on the discharge region such that the discharge region burns through or is torn open mechanically after the fuse has been ignited.
In the gas bag module shown in WO-A-03/097407 a blast pin is provided in order to expose a tubular discharge region of the gas bag.
In EP-A-1 279 574 a gas bag module is shown in which, in order to expose discharge openings, a slider is moved in a holding piece such that bores formed therein are in alignment with the discharge openings. The hot gas flowing into the gas bag melts the region of the gas bag which is situated between the bores of the slider and the discharge openings in the holding piece, such that a portion of the gas emerges from the gas bag during filling.
A gas bag module is known from U.S. Pat. No. 6,547,274 B in which the opening cross-section of a discharge opening in a carrier plate can be exposed by means of piezoelectrically controlled flaps. The current supply of the piezoelectric elements is controlled for example depending on the posture or physique of the vehicle occupant or on the speed of the vehicle.
SUMMARY OF THE INVENTION
The invention provides a gas bag module which makes it possible to control the discharge behaviour safely for the vehicle occupant without increasing the structural space.
According to the invention, a gas bag module for a vehicle occupant restraint device comprises a gas bag and a discharge arrangement in fluid connection with the gas bag. The discharge arrangement includes a discharge opening through which gas can escape from the gas bag, and has at least one element made of an electrically activatable polymer actuator to expose and/or alter the discharge opening upon activation of said polymer actuatuor.
Electro-chemo-mechanical actuators which contain an active layer of polymers which change their volume as a function of an electrical field or electrochemical potential, are designated as polymer actuators. In addition to this active layer, the polymer actuators essentially comprise a passive carrier layer which forms a sandwich-like composite with the active layer, such that when the voltage changes, the composite bends in a similar manner to a bimetal strip with a variation in temperature. A metal layer which is in direct connection with the active layer can serve as the electrode for initiating the electrochemical processes in the active layer leading to the change in volume.
The invention makes use of the fact that the polymer actuators can already be operated at voltage changes of a few volts and can achieve large deflections. It is therefore possible to influence the discharge behaviour of a gas bag module in a specific manner with the polymer actuators. More precisely, the element provided according to the invention with the polymer actuator is used to control the effective cross-section of the discharge opening, i.e. the element provides for the creation of a discharge opening and/or a change to the discharge cross-section. Through the use of such an element, costly and large opening mechanisms can be dispensed with. The discharge arrangement according to the invention has the additional advantage that neither explosive substances or the like, nor a melting of gas bag fabric are necessary to expose a discharge opening, i.e. a separation of particles is ruled out.
Basically, the discharge opening which is controlled by means of the discharge arrangement according to the invention, can be provided on a fixed component of the gas bag module or on the gas bag.
The polymer actuator is preferably integrated into the gas bag wall, in particular woven into the fabric of the gas bag wall or connected with the gas bag fabric by being sewn or glued on. Particularly preferably, the electrochemically inert fabric material may serve as the carrier layer for the active layer of the polymer actuator. When a voltage is applied to the polymer actuator, a deformation of the gas bag fabric is then brought about, whereby a discharge region in the gas bag wall can be produced, enlarged or reduced.
In particular, a predetermined breaking point can be provided in the discharge opening, for example through the existence of tear edges or by a change to the structure or thickness of the gas bag fabric on which the polymer actuator acts.
Alternatively, the polymer actuator can also be part of a covering which is arranged over a discharge opening formed in the gas bag wall.
With an arrangement of the polymer actuator on a pivotable flap, a hinge mechanism can be produced for controlling the flap.
Finally, the polymer actuator can act together with a silicone membrane, which is integrated in either the gas bag fabric or the covering, and which bursts through activation of the polymer actuator and exposes the discharge opening.
Advantageous developments of the invention are indicated in the sub-claims.
Further features and advantages of the invention will be apparent from the following description of preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a diagrammatic illustration of the gas bag module according to the invention in a case of load; and
FIG. 2 shows an embodiment of the discharge arrangement.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIG. 1 a vehicle occupant 10 is illustrated, plunging into an inflated gas bag 12 of a vehicle occupant restraint system. The gas bag 12 , which has unfolded out of the housing of a gas bag module 14 , has a gas bag wall 16 on which an electrically controllable discharge arrangement 18 is arranged. The discharge arrangement 18 serves to selectively provide a discharge opening through which gas can escape from the gas bag 12 , i.e. the discharge arrangement 18 provides for a discharge opening and/or a change in the discharge cross-section to be produced. The discharge arrangement 18 comprises a polymer actuator (not illustrated) which is connected directly or indirectly with an electronic control arrangement 20 , i.e. the polymer actuator is able to be activated by the electronic control arrangement 20 .
The polymer actuator preferably comprises a passive carrier layer and also an active layer of a polymer which changes its volume upon application of an electrical field or electrochemical potential, usually in the voltage range of −3V to +3V. A metal layer which can be vapour deposited onto the active layer or the carrier layer serves for contacting or as an electrode. Through the volume change in the active layer as a result of voltage variation, the sandwich-like composite of the active layer and the passive carrier layer bends in a similar manner to a bimetal strip with a variation in temperature. The polymer of the active layer may be selected in particular from the group of piezoelectric polymers, electrostrictive polymers, polymer gels, carbon nano-capillaries, conductive conjugate polymers and ion-conducting polymers. Ion-conducting polymers or polymer gels which serve as a solid electrolyte at the same time and can therefore be used under ambient conditions without further structural measures, are preferred.
In a particularly preferred embodiment, a portion of the gas bag wall in the region of the discharge arrangement 18 serves as a passive carrier layer of the polymer actuator, i.e. the polymer actuator is integrated into the gas bag wall or the gas bag fabric. In this case, a particularly compact type of construction of the discharge arrangement is possible.
In the case of load, when a discharge of gas from the gas bag 12 of the vehicle occupant restraint system is desired, the polymer actuator of the discharge arrangement 18 can be deformed mechanically by the application of an electric voltage. This mechanical deformation of the polymer actuator causes the gas bag fabric to tear in the region of the discharge arrangement 18 and therefore causes a discharge opening to be exposed. The electrical signal which is applied to the polymer actuator may be a pure control signal here, which only brings about the exposure of the discharge opening for example after a particular period of time has elapsed since the gas bag module was activated. However, it may also be a regulating signal, when the discharge opening is only to be exposed in particular cases of load. The electronic control arrangement 20 can therefore also evaluate the data of particular sensors which measure for example the internal pressure in the airbag or determine the weight of the vehicle occupant, and then decide, as a function of the respective case of load, whether the discharge opening is exposed.
In FIG. 2 a preferred embodiment of the discharge arrangement 18 is shown, which can be opened by means of polymer actuators 22 . The fabric of the gas bag 12 is already previously impaired by two intersecting tear edges 24 perpendicular to each other, acting as a predetermined breaking point, in order to facilitate the formation of the discharge opening. In each of the four sectors formed by the tear edges 24 , a polymer actuator 22 is situated respectively on the outer side of the gas bag fabric, the passive layer of the polymer actuator 22 being connected with the gas bag fabric, for example glued on, and the active layer of the polymer actuator 22 lying over it. When the gas bag is activated, the polymer actuators 22 may, if required, also be activated by means of the electronic control arrangement (not shown). In so doing, the active layer reduces its volume and the polymer actuator 22 exerts a force onto the fabric of the gas bag 12 which leads to the fabric tearing open at the sites which have been previously impaired. The fabric then flaps outwards, with the increased internal pressure in the gas bag assisting the formation of the discharge opening. Instead of the gas bag fabric, a silicone membrane can be present in the area of the discharge arrangement 18 , which is connected to the polymer actuator 22 and which tears open through an activation of the polymer actuator.
In addition, the polymer actuator may be arranged on a pivotable flap associated with the discharge opening, the flap being able to be formed on the gas bag. Alternatively, the actuator may be arranged on a flap formed on the housing of the gas bag module 14 , illustrated schematically at 18′ in FIG. 1 .
Finally, by means of the polymer actuators according to the present invention, it is possible to open, close or only change the discharge cross-section of a discharge opening already present for example in the housing 14 of the gas bag module, depending on the respective case of load. | A gas bag module for a vehicle occupant restraint device comprises a gas bag and a discharge arrangement in fluid connection with said gas bag. The discharge arrangement has a discharge opening, through which gas can escape from the gas bag, and at least one element made of an electrically activatable polymer actuator to expose and/or alter the discharge opening upon activation of said polymer actuator. | 1 |
FIELD OF THE INVENTION
This invention relates to a rotary variable electrical resistance device and more particularly to a variable resistance device having a rotatable operating spindle adapted to be secured to a rotatable shaft whose angular rotation is to be followed by the variable resistance device, the device having a novel means of mounting and location with respect to a support such that it is able to accommodate misalignment or bending of the shaft or a degree of axial and radial play in the shaft.
BACKGROUND TO THE INVENTION
Rotary variable electrical resistance devices, eg. potentiometers, are well known in the art. Such a device typically comprises a housing containing an arcuate element of electrical resistance material adapted to be traversed by a wiper of electrically conductive material, the wiper being operated by a rotatable spindle which is supported on bearings in the housing. Adjustment of the setting of the device is effected by rotating part of the spindle which protrudes from the housing. It has hitherto been common practice to mount a variable resistance device with its housing rigidly secured to a support which may, for example, be a rigid plate having a hole through which the operating spindle of the device passes.
It is sometimes required to couple the spindle of a variable resistance device to an operating shaft in order to provide an extension to the spindle or to monitor the degree of rotation of such a shaft. Problems exist in accurately aligning the shaft and spindle and also the shaft may not be absolutely straight. The shaft may also be mounted in such a way that it can exhibit a significant degree of axial and radial play. If a solid coupling is used between the shaft and spindle with any of these conditions existing, then the bearings of the spindle in the housing of the device may be subjected to excessive forces, resulting in damage to the device. Variations in torque in the shaft/spindle assembly may also occur during rotation in these conditions.
It has previously been proposed to deal with this problem by coupling the shaft and the spindle of the device by means of a flexible coupling member. Such a flexible coupling is expensive and often bulky to the extent that insufficient space is available for it to be used in some applications.
SUMMARY OF THE INVENTION
The present invention provides a rotary variable electrical resistance device comprising: a housing; a spindle secured in and arranged for rotation in said housing and adapted to adjust the setting of said device by causing a wiper of electrically conductive material to traverse an electrical resistance element supported on or in said housing, said spindle being adapted to be substantially rigidly secured to the end of a rotatably supported shaft, on a common axis with said shaft, whereby said spindle is rotatable with said shaft and such that said shaft substantially supports said device; means cooperating between said housing and a support to restrain said housing from rotation about the axis of said spindle when said spindle is caused to be rotated by said shaft, said means also being arranged such that said device is displaceable to follow longitudinal and/or lateral displacement of said end of said shaft.
In one embodiment, said means cooperating between said housing and support comprises a rigid member having a portion thereof adapted to be secured to said support and a further portion adapted to engage a recess or opening in said housing or in a part secured to or extending from said housing. In a modification of this embodiment, said means cooperating between said housing and support comprises a rigid member having a portion thereof adapted to be secured to said housing rather than said support and a further portion adapted to engage a recess or opening in said support rather than in said housing or in a part secured to or extending from said support. Backlash resulting from clearance between said member and said recess or opening may be avoided or minimized by providing one or more springs or other suitably resilient material between said member and said housing or said support or said part secured thereto.
Preferably said rigid member comprises a pin or bolt. The said pin or bolt may have a head for engaging said recess or opening; said pin or bolt or said head may be radiused to produce a substantially barrel-shape whereby variations in the angle at which said pin or bolt enters said recess or opening can be accommodated without said pin, bolt or head becoming jammed in said recess or opening.
The said part secured to or extending from said housing or said support suitably comprises a lug, flange, plate or disc having a hole or a recess therein for accommodating said rigid member.
One or more further lugs or flanges may be provided secured to or extending from said housing and each provided with a hole therein through which a screw or bolt with a head may be passed and secured to said support, said head of said screw or bolt being arranged to be clear of said lug or flange to permit displacement of said device to follow said longitudinal displacement of said end of said shaft, while providing a limitation for this displacement of the device.
In a modification of the above arrangement, the plurality of lugs or flanges may be replaced by a single plate, secured to and extending from said device and provided with holes or recesses for accommodating said screws, bolts or pins.
In an alternative embodiment, said means cooperating between said housing and support may comprise a spring blade having one end secured to said support and the other end secured to said housing, said spring blade being deflectable to permit said device to be displaced to follow lateral displacement of said end of said shaft. Said one or said other end of said spring blade may optionally be slideably secured to said support or said housing respectively, eg. by location in a slot or groove in said support or said housing, to permit said device to be displaced to follow longitudinal displacement of said end of said shaft.
In a further embodiment, said means cooperating between said housing and support may comprise a band encircling and spaced from said housing and secured to said support, a suitably resilient material being provided between said band and said housing to permit displacement of said device to follow said displacement of said shaft.
The said band may comprise a metal or plastics material; said resilient material suitably comprises a rubber, eg. silicone rubber.
In a still further embodiment, the means cooperating between the housing and support comprises a pin extending from a disc-shaped member adapted to be clamped at its periphery to said support by means of a ring-shaped member, said pin being arranged for location in an aperture provided in a flange member secured to the housing of the resistance device concentrically with said spindle, said disc shaped member and said support having an opening therein through which said spindle may pass, said flange member being shaped for location within said ring shaped member such that clearance is provided between said flange member and said ring shaped member to permit said device to be displaced to follow said longitudinal and/or lateral displacement of said end of said shaft, the location of said pin in said aperture in said flange member serving to restrain said housing from rotation about said axis of said spindle.
In a modification of this still further embodiment, instead of said pin being provided on the disc shaped member it may be provided extending from the flange member and arranged to be located either in an aperture provided in the disc shaped member or, if the disc shaped member is eliminated, in an aperture provided in said support.
Suitably said ring shaped member is secured to said support by means of screws or bolts.
BRIEF DESCRIPTION OF DRAWINGS
The invention is now described by way of example with reference to the accompanying drawings in which:
FIG. 1 shows a perspective view of an embodiment of a rotary variable resistance device according to the invention;
FIG. 2 shows a section through the embodiment of FIG. 1;
FIG. 3 shows a part-sectioned exploded view of an alternative embodiment of a rotary variable resistance device according to the invention; and
FIG. 4 shows an assembled view of the embodiment of FIG. 3.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a rotary variable electrical resistance device, eg. a potentiometer, is constructed comprising a housing 1 of metal or rigid plastics material containing an arcuate element of electrical resistance material (not shown) adapted to be traversed by a wiper of electrically conductive material (not shown), the wiper being operated by a rotatable spindle 2 arranged for rotation in bearings 3 and 4 in the housing 1, to adjust the setting of the device. Such an arrangement of a housing, arcuate element, wiper and spindle is very well known in variable resistance device technology. The spindle 2 is rigidly secured, by means of a solid coupling 5, to the end of a rotatably supported shaft 6 whose angular rotation is to be followed by the variable resistance device. Shaft 6 may comprise, for example, a throttle control shaft of an internal combustion engine in a motor vehicle, the setting of the variable resistance device being required to be changed by rotation of the throttle control shaft, for effecting control functions in the operation of the engine. The coupled spindle 2 and shaft 6 have a common axis 7. The shaft 6 supports the variable resistance device.
In order to allow the setting of the device to be altered as shaft 6 is rotated, it is necessary to provide means to prevent rotation of the housing 1. A rigid member in the form of a pin 8 is secured at one end into a fixed support 9 which suitably comprises a metal plate or bracket. The end of the pin 8 is suitably threaded and engages a similarly threaded hole in the support 9. The housing 1 of the variable resistance device is provided with a lug or flange 10 extending therefrom and having a hole 11 through it. The variable resistance device is arranged such that the spindle 2 passes through a hole 12 provided in the support 9 and such that the pin 8 locates in the hole 11 in the lug or flange 10. The pin 8, located in hole 11, restrains the housing 1 from rotating about the axis of the spindle 2 when the spindle 2 is rotated by shaft 6. This simple arrangement is advantageous since it allows the variable resistance device to be displaced to follow any longitudinal displacement (i.e. in the direction indicated by arrows A, B) or lateral displacement (i.e. in the direction indicated by arrows C, D and E, F) of the end of shaft 6 which is coupled to the spindle 2, such displacement of the shaft taking place as a result of play in bearings which support it. The arrangement also allows the variable resistance device to tilt to accommodate a situation where the shaft 6 is not perpendicular to the support 9, or as a result of the shaft 6 being bent.
In order to avoid backlash resulting from clearance between the pin 8 and the sides of the holes 11 a suitably resilient material such as a spring or rubber (eg. silicone rubber) can be applied between the pin and sides of the hole to take up the clearance while permitting the necessary displacement to occur.
Although the pin 8 is shown in FIGS. 1 and 2 as having parallel sides, it may be advantageous for the pin to be formed of a barrel shape, thereby minimizing risk of the pin jamming in the hole 11 when the housing 1 of the device is caused to be tilted.
One or more further lugs or flanges 13, similar to lug or flange 10 may be provided, having a hole 14 therein. Such lugs or flanges 10, 13 are often already provided during manufacture of the device and hitherto intended for use in rigidly securing the device to a support. A screw 15 with a head 16 is passed through hole 14 in lug 13 and screwed into a hole provided in support 9. The head 16 of the screw 15 is arranged to be sufficiently clear of the lug 13 to permit the required degree of displacement of the device, while serving to prevent the spindle 2 from becoming decoupled from the shaft 6, e.g., in the event of the arrangement being utilized in conditions of severe vibration. It would be preferable to provide at least two further lugs 13 with screws 15, for this purpose.
Instead of using a plain pin 8, a pin with a head may be substituted, the head engaging the hole 11 in lug 10. Preferably the head of the pin is radiused to provide a barrel shape to prevent the head jamming in the hole when the housing 1 is caused to be tilted.
It may be necessary, for some applications, to preset the variable resistance device to allow a particular phasing between the device and the shaft coupled thereto. This may be achieved by providing a slot in the support 9 and providing one or more lock nuts on the end of the pin 8. Thus, with the lock nuts slack, the housing 1 of the device is rotated, the pin 8 being moved in the slot in support 9 during this rotation. When a desired setting of the device is attained, the pin is locked in place in the support 9 by means of the lock nuts.
Alternatively, the housing 1 of the device can be mounted on a sub-plate such that it can be rotated to a required position on the sub-plate and then clamped, a hole or recess being provided in the sub-plate into which pin 8 locates, operation being otherwise the same as described with reference to FIGS. 1 and 2.
It will be apparent to those skilled in the art to which this invention relates that a number of alternative embodiments can be envisaged which fall within the scope of the invention.
For example, instead of the rigid pin 8 being secured to support 9 and located in the hole 11 in the lug or flange 10, the pin 8 could be secured to lug or flange 10 or directly to the face of the housing of the device and be arranged to be located in a hole provided in the support 9. Alternatively a disc or plate (not shown) could be clamped to the support 9 and provided with an aperture for location by the pin 8, thus obviating the need to provide an aperture in the support for this purpose. This arrangement also permits a predetermined orientation of the device with respect to the support to be achieved which is valuable for phasing purposes.
Also, instead of using the rigid pin 8 shown in FIGS. 1 and 2, a flat spring blade could be substituted which would be secured at one end to the support 9 and at the other end to the side of the housing 1, lug 10 being unnecessary in such an embodiment. This arrangement would permit lateral displacement of the end of shaft 6 to be accommodated, but in the case where longitudinal displacements of the shaft are also required to be accommodated, the end of the spring blade could be slideably secured in a slot or groove in the side of housing 1 or in the support 9.
In an alternative embodiment, instead of using a pin 8 and lug 10, a band of metal or plastics material could be provided encircling, but spaced from, the housing and secured to support 9, a suitably resilient material, such as silicone rubber, being provided between the band and housing to permit displacement of the device while restraining the housing from rotating about the axis of the spindle 2.
It is also envisaged, within the scope of the invention, that a plurality of variable resistance devices could be provided arranged in ganged form on a common spindle axis and each provided with the means restraining the housing from rotation while permitting displacement to follow displacement of a shaft coupled to a spindle at one end of the ganged assembly. If each of the ganged devices is provided with a lug or flange, as denoted by reference numeral 10 in FIGS. 1 and 2, then a single pin 8, extended to pass through the holes in the lugs of all the devices, could be used to allow displacement of the assembly when displacement of the end of the shaft coupled thereto occurs.
A still further embodiment of the invention is illustrated in FIGS. 3 and 4.
A rotary variable electrical resistance device, e.g. a potentiometer, is constructed comprising a housing 21 of metal or rigid plastics material containing essential elements as previously described with reference to FIGS. 1 and 2. A rotatable spindle 22 extends from the housing for adjusting the setting of the device, spindle 22 being intended to be rigidly coupled to the end of a rotatably supported shaft (such as the shaft 6 shown in FIGS. 1 and 2) whose angular rotation is to be followed by the variable resistance device.
To permit the device 21, 22 to be displaced to accommodate any longitudinal and/or lateral displacement of a shaft to which the spindle is coupled and to restrain the housing 22 from rotation about the axis of the spindle 22 when the spindle is rotated, the following arrangement is employed. A disc shaped member 23 is arranged to be clamped at its periphery to a support 24 by means of a stepped ring shaped member 25, using screws 26 for securement of the member 25 to the support 24. A pin 27 extends from the disc shaped member 23 for location in an aperture 28 provided in a circular flange member 29 having a hole through its center secured to the housing 21 of the device, concentrically with the spindle 22, by means of nut 30. The disc shaped member 23 and support 24 each have a hole therein through which the spindle 22 may pass. The flange member 29 is shaped for location within the stepped ring shaped member 25 such that clearance is provided at region 31 between the flange member 29 and ring shaped member 25 to permit the device 21, 22 to be displaced to follow any longitudinal and/or lateral displacement of a shaft secured to the spindle 22. The pin 27, located in aperture 28 in the flange member 29, restrains the housing 21 from rotation about the axis of the spindle 22 when the latter is rotated.
In a modification of this further embodiment (not shown) instead of pin 27 being provided on the disc shaped member 23, it may be provided extending from the flange member 29 and arranged to be located in an aperture provided in the disc shaped member 23. With this arrangement, the disc shaped member 23 may be eliminated if desired and the pin located in an aperture provided in the support 24. In this latter case the ring shaped member 25 would be secured to the support 24 without the intermediary of the disc shaped member 23.
A further advantage of the present invention is particularly evident where a variable resistance device is operated in conditions where mechanical vibration exists. Where a device of the prior art is rigidly mounted and coupled to an operating shaft, such vibration sometimes results in what is known in the art as `dither.` This involved the cyclic movement of the wiper of the device on the resistance track over a range of frequencies and relatively small angular amplitudes and can result in wear occurring on the track. With the present invention, a small amount of slackness or resilience in the coupling between the housing of the device and support advantageously attenuates the effect of such vibrations and reduces the effect of `dither` wear on the resistance track. | A rotary variable electrical resistance device comprises a housing; a spindle, arranged for rotation in the housing to adjust the setting of the device, and arranged to be rigidly secured to the end of a rotatably supported shaft serving as an extension of the spindle or whose angular rotation is to be monitored by the device and such that the shaft effectively supports the resistance device. The housing is restrained from rotation by a member such as a pin on a disc secured to a support by a ring shaped member and engaging an opening or recess in a flange secured to the housing. Clearance between the members allows the device to be displaced to follow displacement of the shaft resulting from play in bearings supporting the shaft or misalignment or bending of the shaft and obviates the necessity for the expensive and bulky flexible couplings of the prior art. | 7 |
FIELD OF THE DISCLOSURE
This disclosure generally relates to splitters used to combine and separate signals in a frequency-division communication system, such as a digital subscriber line operating in a frequency band above a conventional telephone signal.
RELATED ART
For frequency division communications systems, various signal splitters are available for combining and separating a broadband signal, such as an asymmetric digital subscriber line-2+(ADSL2+) signal or other digital subscriber line (DSL) signal, and a plain old telephone service (POTS) signal wherein the signals have been combined for transmission over a twisted wire pair of a telephone cable. Such splitters generally comprise a low-pass filter for passing the low frequency components of the POTS signal to telephone equipment and a high-pass filter for passing the high frequencies of the broadband signal to a data transceiver.
In general, a conventional splitter isolates the voice and data services so that they do not interfere with one another. However, during certain events associated with normal POTS service such as ring trip, the conventional splitter may fail to provide sufficient isolation, leading to errors in the broadband data. In some applications, a higher-level communications protocol can cope with the errors by various means, such as requesting a retransmission. Other time sensitive applications are less tolerant of errors. For example, errors in a streaming video signal delivered over a DSL circuit may be observed on a video display device before retransmission can occur. In such applications, there is a need for a robust splitter that provides sufficient isolation between the POTS and DSL service under all normal loop conditions.
BRIEF DESCRIPTION OF THE DRAWING
The disclosure can be better understood with reference to the following drawings. The elements of the drawings are not necessarily to scale relative to each other, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Furthermore, like reference numerals designate corresponding parts throughout the figures.
FIG. 1 is a block diagram illustrating a conventional frequency-division communication system using conventional splitters for separating telecommunication signals.
FIG. 2 is a diagram illustrating a typical instantiation of the xDSL-over-POTS system depicted in FIG. 1 .
FIG. 3 is a block diagram illustrating a frequency-division communication system having a current-limited splitter in accordance with an exemplary embodiment of the present disclosure.
FIG. 4 is a block diagram illustrating a frequency-division communication system having a current-limited splitter in accordance with an exemplary embodiment of the present disclosure.
FIG. 5 is a circuit diagram illustrating an embodiment of a current limiter depicted in FIG. 3 or FIG. 4 using depletion-mode metal-oxide field effect transistors (MOSFET).
FIG. 6 is a block diagram illustrating an exemplary current limiter, such as is depicted in FIG. 3 or FIG. 4 .
FIG. 7 is a circuit diagram illustrating an exemplary embodiment of a current limiter, such as is depicted in FIG. 3 or FIG. 4 , using enhancement-mode MOSFETs.
FIG. 8 is a circuit diagram illustrating an exemplary embodiment of a current limiter, such as is depicted in FIG. 3 , using depletion-mode MOSFETs.
FIG. 9 is a circuit diagram illustrating an exemplary embodiment of a current limiter, such as is depicted in FIG. 3 , using depletion-mode MOSFETs.
FIG. 10 is a circuit diagram illustrating an exemplary embodiment of a current limiter, such as is depicted in FIG. 3 , using enhancement-mode MOSFETs.
DETAILED DESCRIPTION
In general, embodiments of the present disclosure pertain to signal splitting systems and methods having improved robustness against large-signal transients in a frequency-division communication system, such as when broadband data is transported on the same pair of wires as a POTS signal. Without sufficient large-signal immunity, the isolation typically provided by a conventional splitter could degrade to the point that the services interfere with one another. Audible noise may become present on the telephone, and broadband data may be lost. This disclosure focuses on the impact to the broadband service, though the POTS service will receive some benefits as well. While some broadband applications such as web surfing can easily recover from lost data, other applications, such as streaming video, operate in real time or near real time and are much less tolerant of data loss.
FIG. 1 shows a block diagram of an exemplary frequency division communication system 50 wherein a broadband signal, such as an ADSL2+ signal or other type of DSL signal, and a conventional phone signal (a voiceband signal or VB signal) are transported together over a common medium 23 , such as a twisted wire pair. A broadband transceiver (TX/RX) 6 , which comprises a data transmitter and data receiver, at a Central Office (CO) communicates with a broadband transceiver 12 , which comprises a data transmitter and data receiver, at a customer premise in a high frequency band. The transceivers 6 , 12 are configured to communicate DSL signals (e.g., ADSL2+). In other examples, the transceivers 6 , 12 can be configured to communicate other types of data signals (e.g. VDSL2).
Many DSL signals start around 25 kHz and extend into the MHz realm. Equipment 19 at the CO comprises POTS switch 8 communicates with a telephone 10 in a low frequency band. POTS communication typically occurs in the 200 Hz to 4000 Hz band, often referred to as the voice band (VB), but supervisory signaling may produce spurious noise at higher frequencies. At the CO, a signal splitter 18 serves to isolate the POTS and DSL services from one another by feeding the appropriate frequency band to the termination equipment 6 , 8 via a low-pass filter (LPF) 2 and a high-pass filter (HPF) 1 as shown. Similarly, customer premise equipment (CPE) 21 comprises a DSL transceiver 12 and a telephone 10 connected to the line 23 via a CPE splitter 22 , which comprises a LPF 30 and a HPF 24 , similar to the CO splitter 18 .
FIG. 2 shows more detail of how a conventional DSL over POTS communication system is typically implemented in practice. During an initial learning phase known as “training,” the CO transceiver 6 and the CPE transceiver 12 probe the communication channel over line 23 to learn its transfer function, which is affected by things like the impedance Zco of the CO LPF 2 , the characteristics of cable 20 , and the impedance Zcpe of the CPE LPF 30 , as well as the HPF 1 , 24 associated with each modem transceiver 6 , 12 . While many DSL implementations can adapt to slow changes in the transfer function, it is assumed for simplicity that there will be no rapid deviations in the communication channel.
For historical reasons, POTS service employs large signals and various impedance conditions to indicate supervisory states to the far end. Neither of these mechanisms is friendly to broadband and can pose serious problems as broadband applications, such as DSL, continue to evolve. While the actual POTS voice signal is intended to be band limited from roughly 200 Hz to 4 kHz, supervisory state changes can create transient signals containing spectral content in the band employed by the broadband service. Of particular concern is the condition in which a person answers a ringing telephone 10 . The circuit 8 applying the ringing requires an interval to detect the off-hook condition of the phone 10 , during which time large ringing voltages are applied to a low-impedance off-hook telephone 10 . Beyond just the spectral noise created by the transients associated with change from high impedance to low impedance of the phone, the resulting currents can be much larger than during other operating states.
In fact, the currents can be so large as to impair the operation of the LPFs 2 , 30 . Conventional splitters are passive in nature, consisting of resistors, inductors, capacitors, and perhaps protection devices. The inductors are the elements that primarily set the impedance of the LPF (Zco or Zcpe) in the DSL band. When current flows through an inductor, it creates a magnetic field proportional to the current. However, as known to those in the art, real inductors have limitations on the magnetic field intensity (also known as flux density) that they can support, beyond which the device saturates and ceases to behave inductively. If enough current flows through the inductors to cause them to saturate, isolation between the POTS and DSL service will likely be degraded and the impedance of the LPF (Zco and/or Zcpe) will likely change, disturbing the transfer function of the DSL system and ultimately causing bit errors.
While particular construction details affect the maximum flux density that an inductor can handle without saturating, physical size is the primary limiting factor. It is possible to build inductors that can withstand ring trip currents without saturating, but they are generally large and do not generally minimize the energy associated with supervisory state changes. By combining a current limiter (CL) 200 with a conventional LPF 30 , a current-limited LPF (CL-LPF) 100 can be realized as indicated in FIG. 3 . With a CL-LPF 100 , transient energy from POTS supervisory signals is reduced and inductors in both the CO LPF 2 and the CPE LPF 30 are simultaneously protected from saturation. Moreover, by reducing impedance fluctuations in the LPFs that would otherwise occur due to high current transients, the current limiter 200 reduces disturbances to the transfer function between the transceivers 6 , 12 as compared to a system that does not employ a current limiter 200 as described. Further, a single CL 200 , whether used at the CO or CPE, allows the use of relatively small inductors in both the CO LPF 2 and the CPE LPF 30 , which is in itself a significant advantage to telecommunications providers and equipment manufacturers as space is at a premium. Note that a CL-LPF could alternatively be created at the CO by placing a CL 200 between the CO LPF 2 and the POTS switch 8 , as shown by FIG. 4 , though longitudinal balance would be more critical in this configuration.
FIG. 5 illustrates a conceptual embodiment of a current-limited LPF (CL-LPF) 100 in accordance with the present disclosure. The LPF 30 , shown in a representative ladder arrangement of inductors (L) and capacitors (C), is coupled in series with the current limiter 200 . The phone 10 is represented by load impedance, Z L . The current limiter 200 has characteristics illustrated by the voltage-current curve 202 in FIG. 5 . An examination of curve 202 shows that for small values of current, the limiter 200 has a fixed value of resistance shown by the slope 203 of curve 202 . When the current reaches a threshold value, I max (positive or negative), then the current is clamped to that value. A maximum current value of around 110 mA (milliamperes) will allow normal delivery of POTS while allowing relatively small inductors to be used with the LPFs 2 , 30 of both the CO and CPE. Although 110 mA is a preferred value for one embodiment of the present disclosure, other values may be used for I max .
Known or future-developed current limiters may be used to implement the current limiter 200 , though conventional current limiters may interfere with POTS service in some way. An exemplary embodiment of a current limiter (CL) 200 is disclosed herein, with a block diagram of such a limiter 200 shown in FIG. 6 . Conceptually, the limiter 200 comprises several elements, the first of which is a limiting element 601 , also known as a pass device, which acts to restrict the flow of current. The limiting element 601 is modulated by a feedback control element 603 such that it presents the impedance necessary to achieve the desired limiting function. The current sensing element 602 monitors the current actually flowing through the current limiter 200 at any given time as the input to the feedback control element 603 .
Exemplary embodiments of the current limiter 200 are shown in FIG. 7 through FIG. 10 . The embodiments of the current limiter 200 described herein utilize metal-oxide field effect transistors (MOSFETs or FETs) as the limiting element, a resistor as the current sensing element, and a Bipolar Junction Transistor (BJT) for feedback control, although other types of components may be used in other embodiments.
FIG. 7 shows a CL 200 based on enhancement mode FETs M 1 and M 2 as the limiting elements 601 . A voltage source Vx supplies gate-to-source voltage (Vgs) for the FETs M 1 and M 2 , placing them in a normally conductive, low-impedance state. Resistors RL 1 and RL 2 form the current sensing element 602 , while BJTs Q 1 and Q 2 close the feedback control loop 603 . Consider the case where node Ain is at a positive potential with respect to node Bin such that conventional current flows from Ain to Bin. When the current through the sensing element 602 develops enough voltage to turn on the base-emitter junction (Vbe(on)) of Q 1 , Q 1 begins to conduct, stealing gate drive from the FET M 1 . This increases the impedance of FET M 1 , decreasing the current that flows. Q 1 continues to steal M 1 's gate drive until the voltage developed across the current sensing element 602 reaches exactly Vbe(on) of Q 1 , completing the feedback control 603 to M 1 , the limiting element 601 . For this polarity of current flow, Q 2 remains off, leaving M 2 in its low-impedance state. M 1 and Q 1 are the active limiting element 601 and feedback control element 603 , respectively, for this polarity. When the voltage across the sensing element 602 drops below Vbe(on) of Q 1 , Q 1 quits conducting, restoring gate drive to the FET M 1 and placing it back in a low-impedance state. Due to the symmetry of the circuitry, for the opposite polarity of input such that current flows from Bin to Ain, the principles of the circuit's operation are exactly the same with M 2 serving as the limiting element 601 and Q 2 serving as the feedback control element 603 .
In the normally conductive state, this embodiment of a CL 200 has a total insertion resistance of (RL 1 +RL 2 +RMOS 1 +RMOS 2 ) where RMOS 1 and RMOS 2 are the drain-to-source on resistance of FETs M 1 and M 2 respectively. The maximum current (Imax) allowed by the device (Imax) is Vbe(on)/(RL 1 +RL 2 ). For a current limit of 110 mA, a reasonable value, RL 1 +RL 2 would be about 4.53 ohms as Vbe(on) will be approximately 0.5 Volts for small collector currents. Typical FET devices such as International Rectifier's IRF 730 put RMOS 1 and RMOS 2 at roughly 1 ohm each. This makes for a total insertion resistance of less than 7 ohms.
Low insertion resistance is highly desirable, as additional resistance decreases the supervisory range of the POTS service and adds additional attenuation to the voiceband (VB) signals. The architecture of FIG. 7 has no deadband in the pass function that would otherwise add crossover distortion to the VB signal. As known in the art, crossover distortion generally refers to distortion caused by line voltages close to zero when the line voltage is transitioning from a positive voltage to a negative voltage or vice versa. Such distortion is typically cause by transistors turning off when the line voltage falls below the critical biasing value (Vbe(on) for BJT, Vgs for FET).
The symmetry of the instant embodiment ensures that it will perform equally well for either polarity of input signal. The action of the feedback control element 603 makes the current limit independent of various characteristics of the limiting element 601 , such as the gate-to-source threshold voltage of the FETs used to implement the element 601 .
FIG. 8 shows an alternative embodiment based on depletion-mode MOSFETs M 1 and M 2 as the limiting element 601 . This embodiment removes the need for voltage source Vx of FIG. 7 , as depletion-mode FETs are in their low-impedance conductive state when there is no gate-to-source voltage. Rload represents the load, such as a telephone 10 , and is not part of the current limiter 200 . Considering the scenario where current is flowing from Ain to Bin, M 1 serves as the limiting element 601 , a resistor RL 1 serves as the current sensing element 602 , and a BJT Q 1 serves as the feedback control element 603 . For small currents, BJTs Q 1 and Q 2 are both off and resistors R 1 and R 2 ensure that there is no voltage drop between the gate and source of either M 1 or M 2 . Thus, M 1 and M 2 , being depletion-mode devices, are in their low-impedance conductive state. When sufficient current flows through RL 1 to develop enough voltage to turn on the base-emitter junction (Vbe(on)) of Q 1 , Q 1 conducts, pulling the gate of M 1 negative with respect to its source. This increases the impedance of the FET M 1 , decreasing the current that flows until the feedback loop reaches a steady state condition. For this embodiment, it is desirable for Imax*(Rload+RMOS 2 +RL 1 )>=Vgs(M 1 ), where Vgs(M 1 ) is the threshold voltage of M 1 and RMOS 2 is the drain-to-source resistance of M 2 in its fully conductive state (Vgs=0). This condition ensures that there is sufficient gate drive available for M 1 to reach a high enough impedance to limit the current for any input voltage. For this polarity of current flow, BJT Q 2 remains off, leaving M 2 in its low-impedance state. M 1 and Q 1 are the active limiting element 601 and feedback control element 603 for this polarity. When the voltage across the RL 1 sensing element 602 drops below Vbe(on) of Q 1 , Q 1 quits conducting, placing M 1 back in a low-impedance state. Due to the symmetry of the circuitry, for the opposite polarity of input such that current flows from Bin to Ain, the principles of the circuit's operation are exactly the same with M 2 serving as the limiting element 601 , resistor RL 2 serving as the current sensing element, 602 and BJT Q 2 serving as the feedback control element 603 .
In the normally conductive state, this embodiment of a CL 200 has a total insertion resistance of (RL 1 +RL 2 +RMOS 1 +RMOS 2 ) where RMOS 1 and RMOS 2 are the drain-to-source on resistance of FETs M 1 and M 2 respectively. The maximum current (Imax) allowed by the device is Vbe(on)/(RLx), where x is 1 or 2 depending on the polarity. For the representative case of Imax=110 mA, RLx would be about 4.53 ohms as Vbe(on) will be approximately 0.5 Volts for small collector currents. Typical depletion-mode FET devices such as Supertex DN3535 put RMOS 1 and RMOS 2 have roughly 10 ohms each. This makes for a total insertion resistance of approximately 30 ohms. When Ain is positive with respect to Bin, diode D 2 ensures that no current bypasses the load via the base-collector junction of Q 2 . Diode D 1 serves the same function for Q 1 for the opposite polarity of input signal.
Additional modifications to the current limiter 200 are possible. For the embodiment of FIG. 8 , the feedback control element 603 is implemented via a BJT transistor. As known to those in the art, Vbe(on) of a BJT varies with temperature at a rate of approximately—2 mV/degree Centigrade, causing Imax to vary with temperature as well. Other feedback control instantiations may not have a temperature dependence, but in this case, FIG. 9 shows an exemplary configuration that compensates for temperature variance such that Imax does not vary with temperature. By choosing appropriate values, the voltage divider feeding the base-emitter junction of BJT Q 1 , formed by resistor R 10 and Rtherm 1 , varies at an effective rate of +2 mV/degree Centigrade, where Rtherm 1 is a negative temperature coefficient (NTC) thermistor. The net result is that the current required, Imax, to activate the feedback control element 603 is independent of temperature. Similar compensation is accomplished for BJT Q 2 by the addition of resistor R 20 and Rtherm 2 , which is an NTC thermistor. Compensation can be accomplished for the CL 200 based on enhancement-mode FETs via similar changes to the embodiment shown in FIG. 7 .
FIG. 9 also shows an additional modification that protects the CL 200 from large AC over-voltage conditions such as those that might be experienced during a 60 Hz power fault. During normal operation, nodes Ain and Aout are connected via a low impedance (RL 2 +RMOS 1 ), and are, therefore, at very nearly the same potential for small signal operation. During a fault condition, though, large voltages could potentially be forced across the Ain to Aout nodes. Should the voltage at node Ain become sufficiently negative relative to Aout, capacitor C 1 charges via resistor R 11 , zener diode DZ 1 , and diode Dbypass 1 . During the half-cycle of the AC fault where Ain is positive with respect to Aout, the stored charge on C 1 shuts off M 1 so that M 1 is not dissipating large amounts of power, thereby protecting the current-limiter 200 from component failure. The charge on C 1 is replenished every negative half-cycle, keeping M 1 turned off for the duration of the fault. In this way, M 1 is not exposed to abusive amounts of power during a fault condition. When the fault is removed, C 1 discharges, M 1 returns to a low-impedance state, and normal operation resumes. Capacitor C 2 , zener diode DZ 2 , and diode Dbypass 2 provide similar protection to M 2 that can be understood via the symmetry of the circuit.
Diode Dbypass 1 sits in parallel with the integrated source-to-drain diode of M 1 . The integrated FET diode in many readily available parts is small and not intended to carry large currents. As Dbypass 1 is larger, it turns on at a lower voltage, thus carrying the majority of the current and protecting such integrated diodes from damage. Dz 1 protects the gate-to-source junction of M 1 from damaging voltages, and also provides a path to charge capacitor C 1 . Diode D 10 protects the base-to-emitter junction of Q 1 from excessive reverse voltages.
Diode Dbypass 2 sits in parallel with the integrated source-to-drain diode of M 2 . As Dbypass 2 is larger, it turns on at a lower voltage, thus carrying the majority of the current and protecting such integrated diodes from damage. Dz 2 protects the gate-to-source junction of M 2 from damaging voltages, and also provides a path to charge capacitor C 2 . Diode D 20 protects the base-to-emitter junction of Q 2 from excessive reverse voltages.
FIG. 10 is an exemplary configuration using enhancement-mode FETs. The embodiment shown by FIG. 10 is identical to that shown by FIG. 7 except that various components have been added for providing circuit protection and compensating for temperature fluctuations as described above for the embodiment depicted by FIG. 9 . In particular, temperature dependent thermistors Rtherm 1 , Rtherm 2 have been added to compensate for temperature fluctuations, and zener diodes D 3 , D 7 have been added to protect the circuit from damaging voltages.
In the embodiments shown by FIGS. 7-10 , it can be observed that the components of the current limiter 200 are not connected to a reference voltage (e.g., the load's ground). Indeed, the voltages of the current limiter components float with the line voltage enabling the current limiter to handle a wide range of voltages.
While the embodiments of the present disclosure have been described in detail, it is to be expressly understood that it will be apparent to persons skilled in the relevant art that the embodiments may be modified without departing from the spirit of the disclosure. Various changes of form, design or arrangement may be made to the disclosure without departing from the spirit and scope of the disclosure. | A telecommunication system has a telecommunication line for communicating a combined signal and a splitter that is coupled to the telecommunication line. The splitter has a high-pass filter, a low-pass filter, and a current limiter. The high-pass filter is configured to transmit a first component signal of the combined signal, and the low-pass filter is configured to transmit a second component signal of the combined signal. The current limiter is configured to limit a current of the second component signal thereby preventing at least one inductor in the low-pass filter from saturating. | 7 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. Ser. No. 13/487,915, entitled Anticorrosive Composition, filed Jun. 4, 2012, now U.S. Pat. No. 8,647,532, which is a continuation of U.S. Ser. No. 12/480,986, entitled Anticorrosive Composition, filed Jun. 9, 2009, which claims priority from U.S. Provisional Patent Application Ser. No. 61/059,981, filed Jun. 9, 2008. The entirety of all applications is incorporated hereby reference.
FIELD OF THE INVENTION
[0002] This invention relates in general to corrosion caused by exposure to a corrosive environment and, more specifically, to the use of an anticorrosive agent that has a wide range of applicability in reducing corrosion.
BACKGROUND OF THE INVENTION
[0003] Corrosion problems caused by exposure to and/or the use of chloride salt has been a longstanding problem in many applications and industries, including deicing and anti-icing for roadways and bridges (often causing rebar corrosion), oil well drilling operations, and other industrial and marine applications carried out in corrosive environments. One common industrial application of chloride salts are their use in industrial brines. A brine can be an aqueous solution of chloride salts alone, or in combination with sodium, potassium, calcium and magnesium cations.
[0004] One approach to address corrosion has been the addition of various anticorrosive agents to the chloride salts or brines in order to reduce the corrosive effect. These various additives can be expensive. To a large extent, these additives have been ineffective in controlling the corrosivity of the brines. Similarly, the use of deicing formulations, which commonly include a chloride salt, inherently have a corrosive effect upon roadways, bridges (including rebar corrosion) and the environment. Various anticorrosive additives have been used with these formulations with mixed success.
[0005] The prior art recognizes that the presence of carbohydrates such as corn syrup and molasses, often used in deicing applications, reduces or inhibits corrosion at some level. However, when corrosion is an issue that must be addressed, a separate corrosion inhibitor component is usually added to the carbohydrates. The main reason for this approach is that excessive amounts of the carbohydrate would be required in order to obtain a significant anticorrosive effect due to the relatively small amount of anticorrosive moiety contained in a given carbohydrate. In these cases, specific anticorrosive agents are selected and/or synthesized to be effective in very small concentrations (very often less than 1%) so as not to affect the essential characteristics of the carbohydrate, such as freezing point, viscosity and cost. In fact, excessive concentrations of carbohydrate to accomplish a significant reduction in corrosion could well render the carbohydrate unsuitable for its intended use (e.g., as an effective deicer).
[0006] It can be seen from above that there has been a longstanding need for a solution to these corrosion problems, including the effect on the environment.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The present invention relates to the discovery that melanoidins, and higher molecular weight fractions of products containing melanoidins, provide significant corrosive inhibition, which render these melanoidins suitable for use as anticorrosive agents in corrosive environments. In addition to being highly anticorrosive, the melanoidins of the present invention are environmentally friendly and non-toxic, and can be found in animal food and in human foodstuffs. There are a number of applications and industries where corrosion is a problem that these additives can be used (e.g., additives to industrial brines, deicing formulations for roadways and bridges, oil well drilling, and in other industrial and marine applications where corrosion is a problem).
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a GPC profile for sucrose.
[0009] FIG. 2 illustrates a GPC profile for a component having a molecular weight of 12,400.
[0010] FIG. 3 illustrates a GPC profile for 79.5 Brix Molasses.
[0011] FIG. 4 illustrates a GPC profile for Fraction A obtained from the alcohol precipitation of the molasses.
[0012] FIG. 5 illustrates a GPC profile for the higher molecular weight fraction (retentate) obtained from the dialysis of Fraction A.
[0013] FIG. 6 illustrates a GPC profile for the lower molecular weight fraction (permeate) obtained from the dialysis of Fraction A.
[0014] FIG. 7 illustrates a GPC profile for the higher molecular weight fraction (retentate) obtained from the ultrafiltration of the molasses.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention relates to the discovery that melanoidins, and higher molecular weight fractions of products containing melanoidins, provide significant corrosive inhibition, which render these melanoidins suitable for use as anticorrosive agents in corrosive environments.
[0016] Melanoidins are brown-colored polymers formed by the interaction of amino acids and carbohydrates (e.g., mono-, di-, and oligosaccharides). Melanoidins are formed by a reaction between carbohydrates/saccharides and amino acids during aqueous processing at elevated temperatures (e.g., 70 to 120° C.). This is known as the Maillard Reaction which is a complex reaction with a network of consecutive and parallel chemical reactions.
[0017] Although the molecular weights of melanoidins can vary from about 400 to more than 100,000 depending upon reaction conditions (e.g., temperature, time, pH, water content), the molecular weight of the melanoidins suitable for use in the present invention is above about 10,000, with a preferred range being about 12,400 and higher (i.e., higher molecular weight melanoidins).
[0018] Melanoidins contain groups (e.g., amino, carboxyl) which can chelate ferrous ions. In the corrosion cell, ferrous ions are produced at the steel anode. Inhibition of the corrosion process at the anode occurs when chelation/complexation of the ferrous ions occur. It has been shown that the type of saccharide is a significant factor in the chelation reaction. For example, glucose is more efficient than the disaccharide lactose in iron binding ability. It has also been shown that glucose/glutamic acid readily complexes with several cations e.g. Mg 2+ , Cu 2+ , Ca 2+ and Zn 2+ . Therefore anodic inhibition will occur.
[0019] The cathode in the corrosion cell requires the presence of oxygen for corrosion to occur. Removing oxygen causes cathodic inhibition. Melanoidins from the Maillard Reaction have been shown to have anti-oxidative properties. Researchers have examined a glucose/glycine model and found anti-oxidation effects. Others have used the glucose/glycine model and found that the high molecular weight fraction, with a molecular weight greater than 12,400 was significantly more effective than other fractions. Still others have examined Maillard Reaction products from lactose/lysine model systems and concluded that high molecular weight fractions were more colored and had the highest anti-oxidative activity. Therefore cathodic inhibition will occur.
[0020] Molasses derived from sugar cane was selected as the exemplary source for obtaining the higher molecular weight melanoidins of the description of the present invention. Melanoidins are present in molasses, which is a product of the manufacture and/or refining of sucrose from mainly sugar cane or sugar beets, although molasses can be obtained from the processing of citrus fruit, starch (from corn or grain sorghum) which is hydrolyzed by enzymes and/or acid, also from hemicellulose extract which is a product of the manufacture of pressed wood. However, the scope of the present invention is not limited to a particular source of melanoidins, which may be derived from various agricultural sources (e.g., corn, wheat, barley, rice, sugar beets. and sugar cane, which after processing, yield other products), corn steep liquor (CSL), brewers condensed solubles (BCS), and distillers condensed solubles (DCS). In addition, other products having similar molecular weight (GPC) profiles to these known examples with respect to higher molecular weight components and fractions would also provide melanoidins suitable for corrosion inhibition.
[0021] It is known that a mix (e.g., 80/20) of salt brine and molasses (e.g., 79.5 Brix Molasses) provides significantly more corrosion inhibition as compared to the corrosion caused by the salt brine alone. In order to identify the components in the molasses that contribute to the anticorrosive effect of the product, chromatographic separation (e.g., column chromatography, gel permeation chromatography) can be used to separate the components of a mixture by size, with the results shown on a chromatogram profile.
[0022] For example, in some of the experiments described herein, chromatogram profiles were obtained on various diluted samples using gel permeation chromatography (GPC) under the following chromatography conditions: Column (Bio-S-3000), Mobile Phase (Sodium Azide 0.05%), Detector (Refractive Index), Flow Rate (1.0 mL/min), Injection Volume (10.0 μL), and Run Time (20 minutes).
[0023] FIGS. 1 through 7 show GPC profiles for various samples. Each profile shows peaks for the molecular weights of components present in the sample. Peaks do not necessarily represent a single compound, but, particularly at higher molecular weight ranges, may be comprised of multiple components or polymers having heterogeneous composition. Each profile also provides the elapsed time before a particular molecular weight component was released from the column (retention time (RT)). As general rule, the higher the molecular weight of the component, the shorter the retention time. Likewise, the lower the molecular weight of the component, the longer the retention time. Each profile also provides the height and area of the peak representing a particular molecular weight component, which allows for the determination of the weight percent of that particular molecular weight in the sample.
[0024] For example, FIG. 1 illustrates a GPC profile for sucrose (MW=342) having a retention time under those particular test conditions of 15.371 minutes. Similarly, FIG. 2 illustrates a GPC profile for a component having a molecular weight of 12,400 having a retention time under those same test conditions of 12.993 minutes. Accordingly, based on those standards and under those same test conditions, for components with molecular weights less than 342, one would expect retention times longer than 15.371 minutes. Similarly, for components with molecular weights greater than 12,400, one would expect retention times shorter than 12.993 minutes.
[0025] FIG. 3 illustrates a GPC profile for 79.5 Brix Molasses, which shows a retention time of 15.360 minutes for the most significant peak (i.e., the largest concentration has a molecular weight that corresponds to a retention time of 15.360 minutes). Comparing this GPC profile for the molasses ( FIG. 3 ) to the GPC profile for sucrose (MW=342) ( FIG. 1 ) and the GPC profile for a molecular weight standard of 12,400 ( FIG. 2 ), one can see that there is a significant concentration of sucrose in the molasses and other lower molecular weight components in the molasses (i.e., that would have retention times near 15.371 minutes for sucrose). There is also a very low concentration of higher molecular weight components (i.e., that would have retention times near or less than 12.993 minutes for a MW=12,400).
[0026] Turning to the experiments used to identify the components in the molasses that contribute to the anticorrosive effect of the product, in one experiment, 79.5 Brix Molasses (200 g/150 mL) was diluted (1:1) with distilled water (200 g/200 mL) and then separated into five fractions (A-E) by adding increasing amounts of denatured alcohol (85% ethanol/15% methanol) employing an alcohol precipitation method by sequential addition. Alcohol precipitation is one method of selective precipitation widely used for isolating higher molecular weight fractions from heterogeneous mixtures. In alcohol precipitation, denatured alcohol is used as the non-solvent in a step-wise manner, filtering off the precipitate between each addition.
[0027] Fraction A was a precipitate with the least amount of the alcohol mixture and contained the highest molecular weight components, while fraction E had the greatest amount of the alcohol mixture and was the lowest molecular weight fraction of the molasses. These precipitates could be filtered and dried.
[0028] FIG. 4 illustrates a GPC profile for Fraction A with eight peaks, showing the inclusion of higher molecular weight components with retention times near or shorter than the retention time for MW=12,400 (RT=12.993 minutes), but still having a significant amount of lower molecular weight components with retention times near or longer than the retention time for sucrose (MW=342) (RT=15.371 minutes).
[0029] A 100 ml sample of each fraction (A-E) was then mixed with 400 ml of 30% NaCl to yield an 80/20 mix for corrosion rate testing according to the NACE Standard TM-01-69 Method as modified by the Pacific Northwest Snowfighters (PNS).
[0030] Corrosion rate testing showed that certain fractions include corrosion inhibiting components, with fractions A (55.5% reduction), B (29.4% reduction), and E (63.2% reduction) all reducing the corrosiveness of the magnesium chloride when used alone.
[0031] Organic acid analysis of the molasses and these fractions demonstrated that trans-aconitic acid, which comes from sugar cane, is present in the molasses (1.63%), and more specifically, Fraction A (0.88%) and fraction B (0.23%), but is absent from fraction E. Aconitic acid is a compound found in sugar processing and is the main organic acid in sugar juice and in raw sugar. Aconitic acid is bound or associated with polysaccharides with a molecular weight of 300,000.
[0032] Protein analysis of the molasses and these fractions demonstrated that protein is present in molasses (5.2%), and more specifically, Fraction A (1.9%) and fraction E (1.6%).
[0033] Amino acid analysis of the molasses and these fractions demonstrated that amino acids are present in the molasses (0.37%), and more specifically, in trace concentrations in Fraction A and fraction E, with aspartic acid having the most significant concentration (0.25%).
[0034] Carbohydrate analysis of these fractions demonstrated that the concentration of carbohydrates present (after dilution) in fraction E (5.25%) are sufficient to account for the bulk of the corrosion inhibition shown by that fraction, but the low concentrations of carbohydrates present in fractions A (0.78%) and B (0.40%) are not sufficient to account for corrosion inhibition shown by those fractions.
[0035] Corrosion rate testing on the molasses and selected carbohydrates present in the molasses demonstrated that the corrosion inhibition of the molasses is greater than that of its constituent carbohydrates alone. Furthermore, corrosion rate testing demonstrated that higher molecular weight (HMW) Fraction A, which contains 25% of the total solids in the molasses, exhibits similar corrosion inhibition to lower molecular weight (LMW) fraction E, which contains 60% of the total solids in the molasses.
[0036] Given that data, it was shown that, on a weight basis, the higher molecular weight components in Fraction A have approximately twice the corrosion inhibition activity of the lower molecular weight carbohydrates in fraction E. This suggested the presence of higher molecular weight components in Fraction A other than carbohydrates are largely responsible for the corrosion inhibition demonstrated by that fraction. These higher molecular weight components are melanoidins.
[0037] These various analyses also indicated that approximately 23% of the total solids in the molasses are not organic acids, proteins, amino acids, or carbohydrates, with a significant amount of those unidentified solids (3.5%) present in fractions A and E, which show corrosion inhibition.
[0038] To further identify the higher molecular weight components in the molasses and Fraction A (prepared using alcohol precipitation) that are largely responsible for corrosion inhibition, various techniques can be used, including selective precipitation, dialysis, ultrafiltration, or a combination of those techniques.
[0039] In another experiment, the 79.5 Brix molasses was subjected to dialysis at room temperature using a regenerated thin semi-permeable cellulose (RC) Spectrum Laboratories membrane with a defined molecular weight cut-off of 12,400. The membrane allows the components having molecular weights below the cut-off to pass through or permeate the membrane (“permeate”), leaving behind the components having molecular weights above the cut-off (and lower molecular weight components closely associated with them) that are stopped or retained by the membrane (“retentate”).
[0040] In the experiment, 3 g of the molasses was dissolved in 30 mL of distilled water contained in the cellulose membrane, which was then placed in a 2 L beaker containing 500 mL of distilled water. A magnetic stirrer agitated the contents of the beaker. After at least 24 hours of dialysis, the membrane package containing the brown higher molecular weight fraction (retentate) was removed from the yellow lower molecular weight fraction (permeate). The brown retentate was then dissolved in 500 mL of distilled water.
[0041] The brown higher molecular weight fraction (retentate) contained the higher molecular weight components with molecular weights greater than the cellulose membrane cut-off (12,400) as well as lower molecular weight components that are closely associated with the higher molecular weight components stopped or retained by the membrane. The brown color and molecular weight data indicates the presence of melanoidins in the higher molecular weight fraction (retentate).
[0042] The yellow lower molecular weight fraction (permeate) contained the lower molecular weight components with molecular weights less than the membrane cut-off (12,400) that passed through or permeated the membrane. The yellow color and molecular weight data tends to indicate the absence or limited presence of melanoidins in the lower molecular weight fraction (permeate).
[0043] After the dialysis of the molasses, both the resulting higher molecular weight fraction (retentate) and the lower molecular weight fraction (permeate) contained the relative amounts of components that would be present in a solution of 0.6% molasses (3 g molasses/500 mL distilled water).
[0044] Separate corrosion rate testing was performed on solutions of sodium chloride (3%) combined with molasses, the higher molecular weight fraction (retentate), and the lower molecular weight fraction (permeate) using a method based on the PNS test, modified to increase the speed required to perform the test.
[0045] The results of the corrosion rate testing are shown in Table 1.
[0000]
TABLE 1
Corrosion
Corrosion Inhibitor
Steel Metal
Reduction
Chloride Solution
(Weight % & mg/mL)
Loss (mg)
(%)
3% NaCl
None
49.4
None
(3,000 mg/100 mL)
3% NaCl
0.6% Molasses
20.40
62.3
(3,000 mg/100 mL)
(424.2 mg/100 mL)
3% NaCl
0.6% HMW retentate
13.04
75.9
(3,000 mg/100 mL)
(63.0 mg/100 mL)
3% NaCl
0.6% LMW permeate
23.92
55.8
(3,000 mg/100 mL)
(not recorded)
[0046] The percent reduction in corrosion for a particular solution is calculated by taking the difference between steel metal loss for that solution and the steel metal loss for the chloride salt solution and dividing that difference by the steel metal loss for the chloride salt solution, and multiplying that ratio by 100.
[0000]
%
C
R
=
w
1
-
w
2
w
1
×
100
[0000] where
[0047] w 1 =weight loss of uninhibited chloride solution
[0048] w 2 =weight loss of inhibited chloride solution
[0049] These results demonstrate that the higher molecular weight fraction (retentate) is a far more potent corrosion inhibitor than the molasses or the lower molecular weight fraction (permeate), despite the fact that the solids content of the retentate (63.0 mg/100 mL) is significantly less than the solids content of the molasses (424.2 mg/100 mL) and the permeate (not recorded but approximately 360 mg/100 mL). For example, even though the higher molecular weight fraction (retentate) has almost seven times less solids content than the molasses (i.e., only represents approximately 15% of the dry weight molasses or 10% of the liquid molasses), it provides a much greater reduction in corrosion. The melanoidins present in the higher molecular weight fraction (retentate) inhibit corrosion by both anodic and cathodic inhibition.
[0050] Separate corrosion rate testing was performed on solutions of sodium chloride (3%), magnesium chloride (3%), and calcium chloride (3%) combined with the higher molecular weight fraction (retentate) using the modified PNS test. Triplicate 10 mL samples were evaporated to dryness in an oven for one hour at 105° C., cooled in desiccators for thirty minutes and weighed. The cycle of drying, cooling, and desiccating, and weighing was continued until a constant weight (in mg/100 mL) was obtained.
[0051] The results of the corrosion rate testing are shown in Table 2.
[0000]
TABLE 2
Corrosion
Corrosion Inhibitor
Steel Metal
Reduction
Chloride Solution
(Weight % & mg/mL)
Loss (mg)
(%)
3% NaCl
None
49.4
None
(3,000 mg/100 mL)
3% NaCl
0.3% HMW retentate
20.0
59.5
(3,000 mg/100 mL)
(25.6 mg/100 mL)
3% NaCl
0.6% HMW retentate
17.6
64.4
(3,000 mg/100 mL)
(57.8 mg/100 mL)
3% NaCl
1.0% HMW retentate
12.0
75.7
(3,000 mg/100 mL)
(105.9 mg/100 mL)
3% MgCl 2
None
17.27
None
(3,000 mg/100 mL)
3% MgCl 2
0.6% HMW retentate
7.06
59.1
(3,000 mg/100 mL)
(65 mg/100 mL)
3% CaCl 2
None
38.10
None
(3,000 mg/100 mL)
3% CaCl 2
0.6% HMW retentate
6.54
82.8
(3,000 mg/100 mL)
(62.2 mg/100 mL)
[0052] These results demonstrate that as the concentration of the higher molecular weight fraction (retentate) is increased, the corrosive inhibition also increases. Similar results when combined with other chloride salts (e.g., potassium chloride) would be expected. The melanoidins present in the higher molecular weight fraction (retentate) inhibit corrosion by both anodic and cathodic inhibition.
[0053] In another experiment, Fraction A of the 79.5 Brix Molasses was obtained using the alcohol precipitation method described above. Recall that FIG. 4 illustrates a GPC profile for Fraction A, showing the inclusion of higher molecular weight components with retention times near or shorter than the retention time for MW=12,400 (RT=12.993 minutes), but still having a significant amount of lower molecular weight components with retention times near or longer than the retention time for sucrose (MW=342) (RT=15.371 minutes). Fraction A was then subjected to the same dialysis process described above for the molasses using a cellulose membrane with a defined molecular weight cut-off of 12,400.
[0054] After dialysis, the higher molecular weight fraction (retentate) of Fraction A had a brown color (similar to but less intense than the color of Fraction A) and contained the higher molecular weight components with molecular weights greater than the cellulose membrane cut-off (12,400) as well as lower molecular weight components that are closely associated with the higher molecular weight components stopped or retained by the membrane. FIG. 5 illustrates a GPC profile for the higher molecular weight fraction (retentate) of Fraction A, indicating a major unimodal peak at a retention time of approximately 12 minutes, which is near and shorter than the retention time for MW=12,400 (RT=12.993 minutes). This illustrates the increased concentration of higher molecular weight components in the higher molecular weight fraction (retentate) of Fraction A ( FIG. 5 ) as compared to Fraction A ( FIG. 4 ). The brown color and molecular weight data indicates the presence of melanoidins in the higher molecular weight fraction (retentate) of Fraction A.
[0055] The lower molecular weight fraction (permeate) of Fraction A had a bright yellow color and contained the lower molecular weight components with molecular weights less than the membrane cut-off (12,400) that passed through or permeated the membrane. FIG. 6 illustrates a GPC profile for the lower molecular weight fraction (permeate) of Fraction A, showing five peaks, all with retention times longer than the retention time for MW=12,400 (RT=12.993 minutes). This illustrates the theoretical absence of all higher molecular weight components in the lower molecular weight fraction (permeate) of Fraction A that were stopped or retained by the cellulose membrane. The yellow color and molecular weight data tends to indicate the absence or limited presence of melanoidins in the lower molecular weight fraction (permeate) of Fraction A.
[0056] Molasses Fraction A was subjected to hydrolysis using 2 M trifluoroacetic acid heated at 120° C. for 2 hours. No increase in carbohydrate peaks was observed. The acid caused a precipitate to form related to the HMW material. The addition of sodium hydroxide to neutralize the acid caused the HMW material to dissolve and again be detected by GPC.
[0057] In another experiment, ultrafiltration was used to identify the higher molecular weight components in the 79.5 Brix Molasses that are largely responsible for corrosion inhibition. Ultrafiltration is a pressure-driven process where a fluid stream is pumped at low pressure and high flow rate across the surface of thin semi-permeable polymeric membranes with a defined molecular weight cutoff. As with dialysis previously described, ultrafiltration uses a membrane having a defined molecular weight cut-off that allows components having molecular weights below the cut-off to pass through or permeate the membrane (“permeate”), leaving behind the components having molecular weights above the cut-off (and lower molecular weight components closely associated with them) that are stopped or retained by the membrane (“retentate”). The ultrafiltration equipment used for the experiment was Quix Stand UltraFiltration System (Amersham Biosciences, GE Healthcare) with a Hollow Fiber Cartridge UFP-10-E-3 MA with a nominal molecular weight cut-off of 10,000 and surface area of 110 cm 2 .
[0058] In the experiment, 10 g of molasses was added to 800 mL of distilled water, mixed, and added to the feed reservoir of the ultrafiltration system to obtain a higher molecular weight fraction (retentate) with components having molecular weights above 10,000 and a lower molecular weight fraction (permeate) with components having molecular weights below 10,000. GPC profiles were then obtained using a High Pressure Liquid Chromatograph (HPLC) with a Waters 410 Differential Refractometer under the same chromatography conditions as previously described.
[0059] The reference retention times determined for comparison to some of the later-obtained test results are shown in Table 3.
[0000]
TABLE 3
Retention Time
Molecular Weight
(minutes)
342 (Sucrose)
11.38
1,400
10.61
6,900
9.49
12,400
8.93
20,100
8.41
[0060] FIG. 7 illustrates a GPC profile for the higher molecular weight fraction (retentate) obtained from the ultrafiltration of the molasses. The GPC profile for the higher molecular weight fraction (retentate) shows a total of ten peaks.
[0061] The retention times, weight percents, and molecular weights for each of the peaks are shown in Table 4.
[0000]
TABLE 4
% Area Under
Time Minutes
Curve
Molecular Weight
5.753
2.15
Greater than 100,000
7.634
0.89
40,000
8.536
1.68
18,500
8.789
1.34
14,000
9.150
5.36
10,000
9.594
7.28
7000
10.296
20.69
2700
10.866
0.47
990
11.412
54.27
342
11.768
5.89
180
[0062] Based on the retention time for the standard MW=12,400 (RT=8.93), the GPC profile shows that higher molecular weight components with molecular weights greater than 12,400 make up approximately 6% by weight of the higher molecular weight fraction (retentate), while higher molecular weight components with molecular weights greater than or equal to 10,000 make up approximately 10% of the retentate. Based on the results of the earlier experiments demonstrating that the higher molecular weight fractions (retentate) exhibited superior corrosion inhibition over molasses, additional corrosion rate testing was performed using the retentate from the ultrafiltration process to confirm these earlier results.
[0063] The results of the corrosion rate testing are shown in Table 5.
[0000]
TABLE 5
Steel
Corrosion
Metal
Corrosion
Corrosion Inhibitor
Inhibitor
Loss
Reduction
Chloride Solution
(mg/100 mL)
(ppm)
(mg)
(%)
3% NaCl
None
None
74.81
None
(3,000 mg/100 mL)
3% NaCl
Molasses
8,870
43.65
41.65
(3,000 mg/100 mL)
(904.5 mg/100 mL)
3% NaCl
Molasses
2,150
46.15
38.31
(3,000 mg/100 mL)
(219.2 mg/100 mL)
3% NaCl
HMW retentate
2,440
26.90
64.04
(3,000 mg/100 mL)
(248.8 mg/100 mL)
3% MgCl 2
HMW retentate
585
39.36
47.39
(3,000 mg/100 mL)
(59.7 mg/100 mL)
[0064] These results once again demonstrate the superior corrosive inhibition of the higher molecular weight fraction (retentate) as compared to the molasses. For example, although the concentration of molasses (904.5 mg/100 mL) on a weight basis is approximately fifteen times greater than the concentration of the higher molecular weight fraction (retentate) (59.7 mg/100 mL) in one example, the retentate resulted in approximately 6% greater corrosion reduction (a relative improvement of approximately 14%).
[0065] Based on that data, on a weight basis, the higher molecular weight fraction (retentate) is approximately 17 times more efficient as a corrosion inhibitor than molasses (i.e., 14% improvement on top of a weight difference of 15 times). The previously described experiments have shown that it is the higher molecular weight components in the retentate of the molasses (i.e., those components with molecular weights greater than 10,000 or 12,400) that provide the greatest and most unexpected corrosion inhibition. Those components only constitute 6% to 10% of the weight of the retentate. Given this data, those higher molecular weight components are approximately 170 to 280 times more efficient as a corrosion inhibitor than molasses on a weight basis. The melanoidins present in the higher molecular weight fraction (retentate) inhibit corrosion by both anodic and cathodic inhibition.
[0066] There are a number of applications and industries where corrosion is a problem that additives including melanoidins (or higher molecular weight fractions of melanoidin-containing products) can be used (e.g., additives to industrial brines, deicing formulations for roadways and bridges, oil well drilling, and in other industrial and marine applications where corrosion is a problem). Any suitable concentration of the higher molecular weight fraction of the melanoidin-containing product that effectively reduces corrosion in a chloride salt, brine, or a deicing formulation may be used. A typical concentration can vary from about 0.03 to 10.0% by weight. For example, one embodiment of a deicing formulation using the melanoidins of the present invention is as an additive to a known deicing and anti-icing formulation:
[0000]
Weight %
Low Molecular Weight Carbohydrate
3 to 60
Inorganic Freezing Point Depressant
5 to 35
HMW Fraction of Melanoidin-
0.03 to 10.0
Containing Product
Thickener
0.15 to 10 (optional)
[0067] The basic composition of the known deicing formulation consists of at least the first two of the following three components in aqueous solution depending upon ambient weather conditions, terrain, nature and amount of freezing/snow precipitation, and environmental concerns:
[0068] (1) Inorganic freezing point depressants preferably in the form of chloride salts which include magnesium chloride, calcium chloride and sodium chloride. Metal acetates e.g. calcium magnesium acetate, may also be used.
[0069] (2) Low molecular weight carbohydrates in the 180 to 1,500 range (180-1,000 preferred) wherein the carbohydrate is at least one selected from the group consisting of glucose, fructose and higher saccharides based on glucose and/or fructose and mixtures thereof. These carbohydrates can be obtained from a wide range of agricultural based products such as those derived from corn, wheat, barley, oats, sugar cane, sugar beets etc and products such as corn syrup and molasses.
[0070] (3) Thickeners are used in certain applications as the third key component to increase the viscosity of the composition so that the liquid remains in contact with the road surface or with the solid particles in piles of rocksalt/sand, or rocksalt/aggregates, or salt alone, or sand or aggregate. Thickeners are mainly cellulose derivatives or high molecular weight carbohydrates. Typical molecular weights for cellulose derivatives are for methyl and hydroxy propyl methyl celluloses from about 60,000 to 120,000 and for hydroxy ethyl celluloses from about 750,000 to 1,000,000. Carbohydrate molecular weights range from about 10,000 to 50,000.
[0071] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to make and use the invention. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims. | The present invention relates to the discovery that melanoidins, and higher molecular weight fractions of products containing melanoidins, provide significant corrosive inhibition, which render these melanoidins suitable for use as anticorrosive agents in corrosive environments. In addition to being highly anticorrosive, the melanoidins of the present invention are environmentally friendly and non-toxic, and can be found in animal food and in human foodstuffs. | 2 |
FIELD OF THE INVENTION
[0001] This invention relates to a torque indicator between two rotatable members/shafts. More particularly, the invention relates to a hand brake torque indicator reporting a torque differential for use with rail cars.
BACKGROUND OF THE INVENTION
[0002] Across the nation, both persons and goods are always in need of transportation. Various modes are available to transport persons and goods from one location to another including air, rail, road, water, cable, pipeline and space. A mode of transport is a technological solution that makes use of a particular type of vehicle, infrastructure and operation. The transport of a person or of cargo may involve one mode or several modes, with the latter case being called intermodal or multimodal transport. Each mode has its advantages and disadvantages, and a particular mode will be chosen for a trip on the basis of cost, capability, route, and speed.
[0003] For the transport of goods across the United States, the transport is usually accomplished either by rail (freight trains) or highway (tractor trailer). In evaluating which mode of transport to use, the advantages and disadvantages of both must be compared. An advantage for rail transport is that it is capable of high capacity and is energy efficient, while a disadvantage is that it lacks flexibility and is capital intensive. The energy efficiency advantage occurs as a result of the rolling stock, which is fitted with metal wheels, moving with low frictional resistance when compared with road vehicles. Further, power may be provided by a steam engine, diesel engine or electrical transmission. Freight trains in particular can be highly economical, with economy of scale and high energy efficiency. Authorities often encourage the use of cargo rail transport due to its environmental profile.
[0004] The energy efficiency has been noted by the Association of American Railroads, which has documented that (with current technology), for every 27 gallons of diesel consumed by trucks to haul one ton of freight, railroads use only seven gallons to reach a similar distance. As part of its “Freight Railroads Go the Distance” campaign, the association notes that in 2007, U.S. railroads moved a ton of freight an average of 436 miles per each gallon of fuel, a 3.1 percent improvement vs. 2006 and an 85.5 percent improvement versus 1980, the AAR said. Railroads continue to take steps to further reduce fuel consumption and air emissions, such as by working with suppliers to develop technologies that reduce locomotive idling, as well as hybrid and gen-set switchers for yards, and other hybrid and fuel-cell locomotives, the association said. Given its dramatic energy efficiency over other modes of transport, it is likely that freight transport via rail will continue to increase for decades to come.
[0005] As in any endeavor, there are certain risks and dangers inherent in rail travel. These risks occur both while the train cars are in motion and when they are still. Particularly dangerous situations are created when one or more cars are supposed to be in a stationary position, such as in rail yards, hubs, and other locations. Frequently, one or more cars may be peeled off of a train for short term or long term storage. When the cars are cut from the train, a hand brake is applied (typically via a hand wheel or lever) to engage a brake on the car to prevent unwanted movement of the rail car. In practice, a person engages the hand wheel/lever to apply a torque to a shaft, which in turn engages the brake system. To date, there is no means available for the user to ascertain how much torque has been applied to the shaft, and in turn, to the brake system. All too frequently, too little torque is applied and the rail cars move prematurely and unexpectedly. Many times, the result is a runaway car(s), an event that happens daily. As even an unloaded rail car can weigh in excess of 60,000 pounds (and in excess of 286,000 pounds or more if there are goods in the rail car which is common in cut car(s)), significant damage can be caused to persons, goods, and other rail equipment that is impacted by the runaway cars(s). Unfortunately, impacts with humans occur with regularity and often result in substantial injuries or death. What is needed is an effective means for a user to ascertain how much torque is applied to the shaft/brake system. Another benefit of ascertaining the amount of torque is to prevent a user from applying an unnecessarily high torque wherein such an application of torque may result in injuries to the user through over exertion, etc. or to the brake system itself.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to a novel torque indictor for a hand brake on a freight car, the torque indicator comprising: a first rotatable member having a first end, a second end, a first member cross sectional shape, and a central axis about which the first rotatable member is able to pivot, a second rotatable member having a first end, a second end, a second member cross sectional shape, and a central axis about which the second rotatable member is able to pivot, a coupler engaged with both the first rotatable member and the second rotatable member wherein the coupler indicates a torque between the first rotatable member and the second rotatable member when at least one of the first rotatable member and the second rotatable member is pivoted with respect to the other via the coupler, wherein the coupler has a first end and a second end spaced a distance from the coupler first end and wherein the coupler has a central axis. The devices may be constructed to various dimensions and configurations to fit into a multitude of locations. The present invention provides a hand brake torque indicator which is particularly suitable for railroad use for freight cars, passenger cars and locomotives and may be installed for new cars or retrofitted into existing cars with various installations including, but not limited to, those with hand wheel and lever activated hand brake systems.
[0007] According to one exemplary embodiment of the present invention, the device comprises, in combination with a rotatably driven shaft, a hand wheel assembly for manually turning of the shaft, and a coupler for coupling the hand wheel assembly with the shaft wherein the coupler indicates a torque between the hand wheel assembly and the shaft.
[0008] In another exemplary embodiment, the device comprises a torque indictor for a hand brake, the torque indicator comprising: A torque indictor for a hand brake, said torque indicator comprising: a coupler mountable with both a first rotatable member and a second rotatable member, the coupler having at least one torsional element which is engaged with both the first rotatable member and the second rotatable member wherein the coupler indicates a torque between the first rotatable member and the second rotatable member.
[0009] In another exemplary embodiment, the device reports and/or indicates a torque differential between two rotatable shafts, the device comprises a first rotatable shaft, a second rotatable shaft, a coupler connecting the first rotatable shaft and the second rotatable shaft having at least one torsional element, wherein as first rotatable shaft is rotated, it becomes constrained and wherein below a minimum activating torque, as the second rotatable shaft is pivoted, the first rotatable shaft is caused to pivot or rotate without additional torque above the minimum activating torque between the first and second rotatable shafts.
BRIEF DESCRIPTION OF THE FIGURES
[0010] FIG. 1A illustrates a side view of an exemplary embodiment of the present invention;
[0011] FIG. 1B illustrates a side view of a prior art handwheel configuration;
[0012] FIG. 2A illustrates a perspective view of an exemplary embodiment of the present invention;
[0013] FIG. 2B illustrates a perspective view of a prior art handwheel configuration;
[0014] FIG. 3 illustrates an exploded partial perspective view of an exemplary embodiment of the present invention;
[0015] FIG. 4 illustrates an exploded perspective view of an exemplary embodiment of the present invention;
[0016] FIG. 5A illustrates a perspective view of an exemplary embodiment of the present invention;
[0017] FIG. 5B illustrates another perspective view of the exemplary embodiment of FIG. 5A ;
[0018] FIG. 6A illustrates a perspective view of a first coupler member of an exemplary embodiment of the present invention;
[0019] FIG. 6B illustrates another perspective view of the first coupler member of FIG. 6A ;
[0020] FIG. 7 illustrates a perspective view of a torsional element portion of an exemplary embodiment of the present invention;
[0021] FIG. 8A illustrates a perspective view of a second coupler member of an exemplary embodiment of the present invention;
[0022] FIG. 8B illustrates another perspective view of the second coupler member of FIG. 8A ;
[0023] FIG. 9A illustrates an end view of a torsional element and a first coupler member of an exemplary embodiment of the present invention in a first position;
[0024] FIG. 9B illustrates another end view of the torsional element and first coupler member of FIG. 9A in a second position;
[0025] FIG. 9C illustrates another end view of the torsional element and first coupler member of FIGS. 9A-B in a third position;
[0026] FIG. 10A illustrates a perspective view of a torsional element and a first coupler member of an exemplary embodiment of the present invention;
[0027] FIG. 10B illustrates another perspective view of the torsional element and first coupler member of FIG. 10A ;
[0028] FIG. 11A illustrates a perspective view of a torsional element and a second coupler member of an exemplary embodiment of the present invention;
[0029] FIG. 11B illustrates another perspective view of the torsional element and second coupler member of FIG. 11A ; and
[0030] FIG. 12 illustrates an end view of an exemplary embodiment of the present invention with a handwheel or lever.
DETAILED DESCRIPTION OF THE INVENTION
[0031] To promote an understanding of the principles of the present invention, descriptions of specific embodiments of the invention follow and specific language is used to describe the specific embodiments. It will nevertheless be understood that no limitation of the scope of the invention is intended by the use of specific language. Alterations, further modifications, and such further applications of the principles of the present invention discussed are contemplated as would normally occur to one ordinarily skilled in the art to which the invention pertains.
[0032] FIG. 1A illustrates a side view of an exemplary embodiment of the present invention. FIG. 1B illustrates a side view of a prior art handwheel configuration. FIG. 2A illustrates a perspective view of an exemplary embodiment of the present invention. FIG. 2B illustrates a perspective view of a prior art handwheel configuration. FIG. 3 illustrates an exploded partial perspective view of an exemplary embodiment of the present invention. FIG. 4 illustrates an exploded perspective view of an exemplary embodiment of the present invention. FIG. 5A illustrates a perspective view of an exemplary embodiment of the present invention. FIG. 5B illustrates another perspective view of the exemplary embodiment of FIG. 5A . FIG. 6A illustrates a perspective view of a first coupler member of an exemplary embodiment of the present invention. FIG. 6B illustrates another perspective view of the first coupler member of FIG. 6A . FIG. 7 illustrates a perspective view of a torsional element portion of an exemplary embodiment of the present invention. FIG. 8A illustrates a perspective view of a second coupler member of an exemplary embodiment of the present invention. FIG. 8B illustrates another perspective view of the second coupler member of FIG. 8A . FIG. 9A illustrates an end view of a torsional element and a first coupler member of an exemplary embodiment of the present invention in a first position. FIG. 9B illustrates another end view of the torsional element and first coupler member of FIG. 9A in a second position. FIG. 9C illustrates another end view of the torsional element and first coupler member of FIGS. 9A-B in a third position. FIG. 10A illustrates a perspective view of a torsional element and a first coupler member of an exemplary embodiment of the present invention. FIG. 10B illustrates another perspective view of the torsional element and first coupler member of FIG. 10A . FIG. 11A illustrates a perspective view of a torsional element and a second coupler member of an exemplary embodiment of the present invention. FIG. 11B illustrates another perspective view of the torsional element and second coupler member of FIG. 11A . FIG. 12 illustrates an end view of an exemplary embodiment of the present invention with a handwheel or lever. In the various figures, like members are referenced by like reference numbers.
[0033] FIGS. 1A , 2 A illustrate side and perspective views of an exemplary embodiment of the present invention showing an exemplary relationship between a coupler 10 , a first rotatable member 12 (which may be a component of a brake linkage 14 ) and a second rotatable member 22 . As discussed herein, coupler 10 may indicate a torque. Although illustrated as a shaft, first rotatable member 12 may be comprised of any suitable member including, but not limited to, a shaft, wheel, lever, and gear. Similarly, second rotatable member 22 may be comprised of any suitable member including, but not limited to, a hand wheel, shaft, lever, and gear. FIGS. 1B , 2 B illustrate side and perspective views of a prior art handwheel/brake configuration. In the prior art device, a hub 11 statically connects a first rotatable member 12 to a conventional handwheel 25 .
[0034] FIG. 3 illustrates a perspective view of an exemplary embodiment of the present invention. In the illustrated embodiment, coupler 10 may attach to both a first rotatable member 12 and a second rotatable member 22 . Coupler 10 may have any number of indicia rings 24 , 26 , 30 , 32 (note that there may be zero or more rings and that such indicia rings may be rings, discs, rectangles or any other suitable shape). Further, such indicia ring(s) 24 may have indicia 28 thereon for indicating a torque or other measurement (see FIGS. 4 and 12 ). In some embodiments, indicia 28 on indicia ring 24 may cooperate with indicia 28 on another indicia ring 26 such that a torque (or other measurement) may be illustrated. In the embodiment of FIG. 4 , indicia 28 on indicia rings 24 , 26 cooperate to show a torque (60 foot-pounds as illustrated, for example). In this embodiment, as handwheel 22 is rotated clockwise, coupler 10 is urged to rotate clockwise. If first rotatable member 12 is not constrained, handwheel 22 , coupler 10 , and first rotatable member 12 will rotate together and the torque indicated will not increase. It is when first rotatable member is constrained that an indicated torque may increase and be indicated on coupler 10 as discussed more fully below. In some embodiments, the minimum torque indicated by indicia 28 may be negative, while in other embodiments the minimum torque may be zero. In yet other embodiments, such as that illustrated in FIG. 3 , a minimum torque above zero may be indicated, such as 60 foot-pounds as indicated. In some installations, it may be advantageous to have a minimum torque greater than zero to indicate a minimum input necessary to activate the brake apparatus.
[0035] FIG. 4 illustrates an exploded perspective view of an exemplary embodiment of the present invention. Shown are a brake linkage 14 , with a first rotatable member 12 , first coupler member 16 , torsional element 18 , second coupler member 20 , indicia rings 24 , 26 , 30 , 32 , second rotational member 22 , washer 42 , nut 44 , pin (such as a cotter pin, hairpin, split pin, bowtied cotter pin, circle cotter, although any number of suitable devices/pins may be used) 45 , and various retaining elements 40 for connecting various members to other members. Note that although pin 45 is illustrated in FIG. 4 in a relaxed condition, in an engaged position, pin 45 may be such as that illustrated in FIG. 2A such that the pin has been inserted through a hole in first rotatable member 12 . In the illustrated embodiment, pin 45 may be inserted through such a hole and provide an additional means of restraining one or more of the various components of the invention, such as nut 44 and washer 42 , etc. Such nuts 44 , or other suitable devices, may present a lateral restraint preventing lateral movement of one or more of the coupler members along a central axis of the first rotatable member.
[0036] FIGS. 5A-B illustrate perspective views of an exemplary embodiment of the present invention. Shown is an exemplary configuration of a first coupler member 16 , second coupler member 20 , and torsional element 18 which may connect the first and second coupler members 16 , 20 .
[0037] In the illustrated embodiment, torsional element 18 is received partly by first coupler member 16 and partly by second coupler member 20 . In an exemplary use of such an embodiment, first coupler member 16 may be rotationally fixed to first rotational member 12 while second coupler member 20 may be rotationally fixed with second rotational member 22 . Torsional element 18 may be in contact with both coupler members 16 , 20 such that when one member 16 , 20 is pivoted with respect to the other member 20 , 16 , the torsional element (a spring in the illustrated embodiment) is twisted or compressed. Thus, as one member 16 , 20 is pivoted relative to the other member, torsional member 18 is placed under a torque. Also illustrated is an optional gap 63 which may be occupied by a bushing (as discussed further below). Note that gap 63 may be of any suitable dimension, or may be negated.
[0038] FIGS. 6A-B illustrate perspective views of a first coupler member of an exemplary embodiment of the present invention. First coupler member 16 may be shaped so as to be able to receive at least a portion of torsional element 18 . In the illustrated embodiment, first coupler member 16 has a first surface 70 which may relate to a first surface 72 of torsional element 18 . Further, first coupler member 16 may have a channel/cavity 60 for receiving first rotatable member 12 (herein a squared cross-sectional shape). Of course, channel/cavity 60 and the cross-sectional shape of first rotational member 12 may have any suitable shape including, but not limited to, square, rectangular, round, oval, pentagonal and irregular. Though in some embodiments, the shapes of channel 60 and the cross-sectional shape may correspond, this is not always required. In some embodiments, it may be advantageous to attach coupler 10 (or some portion of coupler 10 ) to first rotatable member 12 . Such attachment may be temporary or permanent and may be accomplished through any suitable means including, but not limited to, screwing, bonding, welding, and gluing. In some embodiments, coupler 10 (or some portion of coupler 10 ) may be formed unitary with first rotatable member 12 . Also illustrated is a first surface 62 of first rotatable member 16 which may be a connection surface with other components.
[0039] FIG. 7 illustrates a perspective view of a torsional element portion of an exemplary embodiment of the present invention. Shown are an exemplary torsional element 18 (herein a spring, although any suitable element(s) may be utilized including, but not limited to, elastomers, rubbers, ceramics, and springs). In this embodiment, torsional element 18 has a first end 52 and a second end 56 .
[0040] FIGS. 8A-B illustrate perspective views of a second coupler member of an exemplary embodiment of the present invention. Second coupler member 20 may have a first slot 54 for receiving an end 56 of torsional element 18 , for example. Also illustrated is a channel/slot 76 which may receive a portion of first coupler member 16 , i.e., shaft 74 . Surface 77 of channel/slot 76 may also be in contact with a corresponding surface of second coupler member 20 or a bushing as discussed further herein.
[0041] FIGS. 9A-C illustrate end views of a torsional element and a first coupler member of an exemplary embodiment of the present invention in a first position, second position, and third position, respectively. As illustrated, as torsional element 18 is twisted, it may twist about shaft 74 of first rotational member 16 . In this embodiment, even as torsional element 18 is pivoted, first end 52 of torsional element 18 may stay in approximately the same position of slot 50 even as second end 56 rotates. In some embodiments, torsional element 18 is permitted to slide along wall(s) 70 , 78 of first coupler member 16 (and/or along wall(s) 80 , 82 , 84 of second coupler member 20 ) such that the spring is able to rotate, and its ends are able to move and/or slide with respect to both first and second coupler member 16 , 20 .
[0042] FIGS. 10A-B illustrate perspective views of the torsional element and a first coupler member of FIGS. 9A-C .
[0043] FIGS. 11A-B illustrate perspective views of a torsional element and a second coupler member of an exemplary embodiment of the present invention. Shown are an exemplary combination of second coupler member 20 and torsional element 18 . Also shown is an exemplary slot 54 in second coupler member 20 which may receive a second end 56 of torsional element 18 .
[0044] FIG. 12 illustrates an end view of an exemplary embodiment of the present invention with a handwheel 110 or lever 112 illustrated in phantom. Illustrated is an exemplary configuration of indicia rings 30 , 32 with indicia 28 thereon for indicating a torque or other measurement on a handwheel, lever, or other device. Note that FIGS. 2A and 12 show a face of said handwheel 110 such that at least one set of indicia is viewable when looking at a face of the handwheel.
[0045] Note that in the reference embodiments, some elements/components may be fixed (either temporarily or permanently) to other members. For example, in some embodiments, indicia ring 24 and/or indicia ring 30 may be in a fixed rotational relationship with first coupler member 16 . Similarly, in some embodiments, indicia ring 26 and/or indicia 32 may be in a fixed relation to second coupler member 20 . Various members of the present invention may also sleeve each other such as shaft 74 of first coupler member 16 which may be received by channel/slot 76 of second coupler member 20 . In some embodiments bushings and other components may be added to the embodiment to further facilitate the motions of the various componentry.
[0046] For example, a bushing may be positioned on a surface of first coupler member 16 or a surface of second coupler member 20 , such as to prevent wear. Bushings may also provide a buffer between first coupler member 16 and torsional element 18 . As are many of the components of the present invention, bushings are optional and may or may not be incorporated into another component.
[0047] Torsional element 18 may be prestressed/pretorqued such that when a torque of less than a predetermined level is applied, a rotation of one of the rotational members, 12 , 22 , the other respective member 22 , 12 pivots. In other embodiments, torsional element 18 may have no prestress/pretorque such that a torque is always indicated on the torque indicator. Note that in some embodiments, only an active torque is indicated, i.e., a torque must be applied to one of the rotational members 12 , 22 in order to read the torque and when the torque is removed, the two rotational members will not be under any torque differential (unless there is a predetermined amount of a minimum torque such as by applying a prestress/pretorque to torsional element 18 ). That is, in some embodiments, the torque indicated on the indicia is a torque differential is reported.
[0048] In some embodiments, a pretorque may be applied to the coupler such that if the second member/shaft is pivoted, the first member/shaft will also pivot. In some embodiments, a constraint may affect the pivotability of the first member/shaft. In some embodiments, the constraint may increase as the first rotatable member is rotated such that as it is rotated, more and more torque is required to pivot the first rotatable member. As the impact of the constraint grows, eventually the pretorque level is reached and a torque differential is created as the second member/shaft is pivoted/rotated with respect to the first member/shaft. In some embodiments, a maximum torque differential may be incorporated into the coupler such that once the maximum torque is reached, the first and second members/shafts rotate together with no increase in torque differential.
[0049] In some embodiments, predetermined stops may be incorporated into one or more members such as first stop member/surface 100 of first coupler member 16 and second stop member/surface 102 of second coupler member 20 as illustrated in FIG. 5B . Other stops may also be incorporated such as first stop member/surface 104 of first coupler member 16 and second stop member/surface 106 of second coupler member 20 . In some embodiments, a stop may be incorporated such that below a predetermined torque level, a surface (or other member) of first coupler member 16 (such as surface 104 for example) may be in contact with a surface (or other member) of second coupler member 20 (such as surface 106 ) such that below the predetermined torque level, surfaces 104 , 106 are in contact and impact each other and the torsional element has little or no impact on the torque. In other embodiments (with or without the stop of the preceding sentence), a stop may be incorporated such that at a maximum predetermined torque one or more surfaces (or other portion) of first coupler member 16 may be in contact with one or more surfaces (or other portion) of second coupler member 20 such that above the predetermined torque level, surfaces (such as, for example, surfaces 100 , 102 may be in contact and impact each other and the torsional element has little or no impact on the torque. For example, a protrusion on first coupler member 16 may engage with a protrusion on second coupler member 20 only at a predetermined torque level. I.e., if the torque is below the predetermined level, first coupler member 16 and second coupler member 20 rotate at least somewhat independently, but at a predetermined threshold, they will rotate together and the torsional element is nullified.
[0050] Note that coupler (including torsional element and fixed element combination) may be designed and defined based on an ergonomic range of motion, such as of a human. In some embodiments, the coupler may be designed and configured such that the rotational angular differential between the shafts may be limited to less than 360 degrees. In some embodiments, the rotational angular differential between the shafts may be limited to less than 180 degrees. In some embodiments, the rotational angular differential between the shafts may be limited to less than 60 degrees.
[0051] Note that the indicia rings discussed herein (or any other components of a particular embodiment) may be a separate component from other elements of coupler 10 or unitary therewith (i.e., indicia may be painted, etched, bonded etc. to any suitable surface or element of coupler 10 ). Further, indicia 28 may include any suitable information/graphics such as, for example, foot-pounds of torque, arrows, warning labels, etc. As known in the art, retaining elements 40 can be comprised of any suitable means including, but not limited to, tape, glue, bonding, screws, bolts, hooks and loops, welding, and paint.
[0052] The coupler may provide the operator/user a reference value of the torque being manually applied to the hand brake by the operator. The coupler provides tactile feedback to the user in conjunction with a visual indication of the torque as it is being applied. The coupler may be used in various configurations for installation both on rotating hand wheel or ratchet type lever brake installations. The coupler may provide a torque reference in either (or both) circumferentially around the axis of rotation and/or axially at the front about the centerline of rotation. The ability to have one or more sets of indicia at one or more of these locations (or other suitable locations) allows the operator the ability to determine the torque input from the normal operating position and provides an alternative reading position that can be viewed from the ground by other personnel in attendance.
[0053] In some embodiments, a minimum torque input may be required to initiate tactile feedback from the coupler. Such a minimum torque may be preset at any desired level, and in some embodiments may be set at 60 foot-pounds, while in other embodiments it may be set at 50 foot-pounds, etc. Some United States railroad regulations consider 60 foot-pounds to be the rail industry accepted “norm” for a minimal hand brake application. In some embodiments, a maximum torque input may be incorporated into a design of a coupler in accordance with the present invention. In some embodiments, the coupler may accommodate a maximum torque input of 125 foot-pounds, which is considered to be equal to the maximum design requirement for a freight car hand brake system per the Association of American Railroads. In some embodiments, the coupler may have physical stops at both the low end of torque input, i.e., 60 foot-pounds for example, as well as at the high end, i.e., 125 foot-pounds.
[0054] Due to the configuration of the coupler, the indicated torque input is the torque at the input of the brake, the reading will be accurate regardless of the diameter of the hand wheel or arm length of the ratchet.
[0055] As a torque is applied to the hand brake, the coupler registers the force reacting against a calibrated internal component which, in turn, rotates against the resistance of the railcar brake mechanism as the brakes are being applied. This calibrated reaction provides a contemporaneous “snap shot” indication of the torque as it is being applied.
[0056] The external snap shot view of the applied torque may provide in any suitable increments and grade. In some embodiments, the torque may be indicated in 15 foot-pound increments/graduations (i.e., 60 to 120 foot-pounds). Such indicia of the torque may be located and configured in any desired manner including, but not limited to, those illustrated in the various figures. The indicia may be placed circumferentially and/or axially to the rotation of the coupler. The torque indicating decals (indicia) may be positioned so as to be visible from the normal operating position on the railcar and from a position on the ground, or other suitable locations. When the operator releases his hold on the wheel/lever hand brake, the torque indication may drop to zero, or to a minimum torque if the embodiment has a minimum torque other than zero. If the coupler has a predetermined minimum torque of 60 foot-pounds, for example, the coupler may indicate only that the torque is below 60 foot-pounds without indicating an exact torque. Each subsequent application of force (and thereby torque) by the operator again provides an indication of the torque being applied to the hand brake.
[0057] Note that in many existing rail cars, and even for cars currently being manufactured, the configuration and mechanism of the hand brake system is configured such that when the hand wheel/lever are engaged by a user, the brake advances, but when the operator releases the hand wheel/lever, the brake system itself does not revert back to a zero condition, but rather stays at the applied torque level (or a level close to the applied torque level allowing for minor losses in slacking down to the next notch in the ratchet means). In practice, when an operator is engaging the hand brakes of a railcar, the operator increases the force/torque until “sufficient” force/torque has been applied as determined by the operator to prevent unintended movement of the parked railcar(s).
[0058] The torque indication may also provide the operator with a value for future reference against which he can cross reference the tactile sensations/feedback of the brake application against the indicated torque. This tactile feedback is valuable as a reference when the operator cannot see the indicia due to poor lighting conditions or when he is operating out of proper position. The operator may also reference the torque that was required to set the hand brake with sufficient force, in his opinion, in the event of run away railcar(s) or personal injury. A primary cause of personal injury results from the over-application of torque/force leading to overexertion by the operator, an event which can easily be avoided through the use of a coupler in accordance with the present invention.
[0059] Some embodiments of the present invention may be configured to be retrofit to existing railcar brake mechanisms including, but not limited to, those meeting the requirements of Association of American Railroads such as AAR S-475. The coupler for a hand wheel type installation may be configured to mate to the hand wheel hub taper defined in AARS-475 Section 8.0. The coupler operating envelope for a hand wheel type installation may be configured to comply with AAR S-475 Section 7.0, or as otherwise desired.
[0060] Torque indicators of the present invention may be made of any suitable material including, but not limited to, plastic, wood, aluminum, metal, carbon fiber, ceramics, acrylics, acrylic glasses, glass and rubber.
[0061] Torque indicators of the present invention may be made of any suitable dimensions and thicknesses. For example, torque indicators may be shaped to accurately fit over the outer edges of a hand brake shaft of a railroad car while simultaneously accommodating a hand wheel. In some embodiments, the torque indicator may be manufactured to specifically meet the requirements of the American Railroad Administration for hand brake assemblies including those using hand wheels.
[0062] Although various components of the present invention may be illustrated as being of a particular shape for convenience, such components may be of any suitable shape, configuration, orientation, etc. Further, any number of additional components may be added to a particular embodiment to accommodate a particular need, including, but not limited to, the addition of one or more grommets, washers, gaskets or other spacing means between two or more of the components of the invention such as between blades, or between blades and one (or more) of the tension members.
[0063] Note that there may be possible advantages of sloping or cutting away part of the material of one or more components, i.e., to utilize less material, or to decrease the weight of the device. As one of ordinary skill in the art would recognize, some advantage can be gained in using less material, but some minimum of material must be maintained to provide sufficient structural integrity for the device to be useful.
[0064] While the specification has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily conceive of alterations to, variations of, and equivalents to these embodiments. | A hand brake torque input indicator arrangement for detecting and indicating a torque of rotating mechanical components has an indicator provided between two rotatable bodies, a shaft and a wheel, which are coupled to the indicator so that a torque acting on the shaft by the wheel or vice versa can be indicated. | 6 |
TECHNICAL FIELD
[0001] The present invention belongs to the field of air handling equipment and, in particular, to a humidifying device and an air handling system.
BACKGROUND OF THE INVENTION
[0002] Air humidity, as a parameter for describing the physical state of the air, is closely related to the health of the human body. In general, when the relative humidity of the air is between 40%-70%, the human intuitive feel is relatively comfortable. During the winter heating period and the spring sandstorm period in China's northern area, the relative humidity of the indoor air is very low, the human body feels uncomfortable, and therefore the indoor humidification is very necessary. Currently on the market, mainstream humidification technology can be divided into three categories: electric heating technology, ultrasonic technology and wet film type humidification technology. However, for the electric heating technology, the power consumption is high and the security is poor; the ultrasonic technology is not good for the health of the human body; and for the wet film humidifying technology, the wet film is easy to breed bacteria and molds; therefore, these three humidification technology is not the best humidification means, and it is of great value and significance to find a humidifying device which is ideal for health.
SUMMARY OF THE INVENTION
[0003] In view of this, an object of the present invention is to propose a humidifying device, comprising an air duct penetrating through the interior of the humidifying device, and a water absorption filter element, which is snap-fitted with the top of an outer wall surrounding the air duct, wherein the water absorption filter element covers the top of the air duct as an air outlet.
[0004] Preferably, the humidifying device further comprises a water channel formed by the outer wall surrounding the air duct, the water absorption filter element extending downward into the water channel.
[0005] Preferably, the humidifying device further comprises an inner annual snap-fitting support body, which is snap-fitted to the top of the outer wall of the air duct, and which comprises a hollow side wall, one end of which is connected to an outer wall of the water channel and the other end is a water absorption filter element bearing part which shields the air duct and supports the water absorption filter element.
[0006] Preferably, the height of the outer wall of the air duct is equal to the height of the inner annual snap-fitting support body.
[0007] Preferably, the humidifying device comprises an outer annual snap-fitting support body for fixing the water absorption filter element and a retaining ring for retaining the water absorption filter element, wherein the water absorption filter element is provided in the outer annual snap-fitting support body and is jointly snap-fitted to the inner annual snap-fitting support body, the retaining ring is arranged in the outer annual snap-fitting support body in a freely detachable manner, and the water absorption filter element is interposed between the outer annual snap-fitting support body and the retaining ring.
[0008] Preferably, the water absorption filter element bearing part is of a grid-like structure or a net-like structure.
[0009] Preferably, the water absorption filter element is higher than an inner wall of the water channel.
[0010] Preferably, the water absorption filter element is of a multilayer net-like structure.
[0011] Preferably, the humidifying device further comprises a humidifying housing which surrounds half of the air duct and mates closely with the water channel, wherein the water channel surrounds the barrel-like outer wall of the air duct and forms an inner humidifying housing with the humidifying housing; and the water channel is integrated with the inner humidifying housing and surrounds the outer wall of the air duct.
[0012] Preferably, a slide rail is provided at the bottom of the inner humidifying housing, and a slideway is provided at the bottom of the water channel matching closely with the humidifying housing, which slideway matches with and is slidably connected to the slide rail.
[0013] Preferably, the humidifying device further comprises a humidifying top cover provided on the top surface of the humidifying device, and a humidifying chassis provided on the bottom surface of the humidifying device, and the air duct penetrates through the humidifying top cover and the chassis.
[0014] Preferably, the humidifying chassis is provided with a lower power source interface and a lower communication interface at the bottom thereof, and the humidifying top cover is provided with an upper power source interface and an upper communication interface. Another object of the present invention is to provide an air handling system, comprising a base and one or more air handling devices disposed on the base, the one or more air handling devices comprising at least one of a humidifying device, a dehumidifying device and a purifying device, wherein the humidifying device is the dehumidifying device as described above.
[0015] According to the humidifying device provided in the present invention, the structure having a water channel and a water absorption filter element is arranged such that the water is conveyed into the air duct through the water absorption to filter element so as to carry out the humidifying operation, the structure is simple, the safety performance is good, there is no “white-powder” pollution, and it is easy to clean the device; and the principle of natural evaporation is adopted, so that the present invention is more green and healthy.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] The accompany drawings constituting part of the present invention are used to provide a further understanding of the present invention; and exemplary embodiments and illustrations thereof of the present invention are used to explain the present invention, and do not unduly limit the present invention. In the drawings:
[0017] FIG. 1 is an exploded view of a humidifying device provided in the present invention;
[0018] FIG. 2 is an exploded view of additional inner and outer annual snap-fitting support bodies of the humidifying device provided in the present invention;
[0019] FIG. 3 is a perspective view of the humidifying device provided in the present invention;
[0020] FIG. 4 is a sectional view of the humidifying device provided in the present invention; and
[0021] FIG. 5 is a partial schematic view of a water absorption filter element and a water channel of the humidifying device provided in the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The following description and the accompany drawings fully illustrate specific embodiments of the present invention so as to enable those skilled in the art to practice the same. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional, and the order of operations may vary, unless explicitly required. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The scope of the embodiments of the present invention encompasses the full scope of the claims, and all available equivalents of the claims. In this context, these embodiments of the present invention may be individually or collectively referred to by the term “invention” for convenience only, and if in fact more than one invention is disclosed, it is not intended to automatically limit that the application is within the scope of any single inventive or inventive concept.
[0023] The humidifying device as shown in FIGS. 1-5 comprises an air duct 1 penetrating through the interior of the humidifying device, and a water absorption filter element 3 , which is snap-fitted with the top of an outer wall surrounding the air duct 1 , wherein the water absorption filter element 3 covers the top of the air duct as an air outlet. In this way, the air passing through the air duct can be remove the water or vapour from the water absorption filter element 3 for humidification.
[0024] The humidifying device further comprises a water channel 2 formed by the outer wall surrounding the air duct 1 , and the water absorption filter element 3 extends downward into the water channel 2 .
[0025] The humidifying device further comprises an inner annual snap-fitting support body 9 snap-fitted to the top of the outer wall of the air duct 1 , and the inner annual snap-fitting support body 9 comprises a hollow side wall, one end of which is connected to an outer wall of the water channel 2 and the other end is a water absorption filter element bearing part which shields the air duct 1 and supports the water absorption filter element 3 .
[0026] The height of the outer wall of the air duct is equal to the height of the inner annual snap-fitting support body.
[0027] The humidifying device comprises an outer annual snap-fitting support body 10 for fixing the water absorption filter element 3 and a retaining ring 4 for retaining the water absorption filter element, wherein the water absorption filter element 3 is provided in the outer annual snap-fitting support body 10 and is jointly snap-fitted to the inner annual snap-fitting support body 9 , the retaining ring 4 is arranged in the outer annual snap-fitting support body 10 in a freely detachable manner, and the water absorption filter element 3 is interposed between the outer annual snap-fitting support body 10 and the retaining ring 4 .
[0028] The water absorption filter element 3 is fixed by arranging the inner and outer annual snap-fitting support bodies 9 and 10 , which does not block the air passing through the air duct.
[0029] The water absorption filter element bearing part is of a grid-like structure or a net-like structure.
[0030] The water absorption filter element 3 is higher than an inner wall of the water channel.
[0031] The water absorption filter element 3 is of a multilayer net-like structure.
[0032] The humidifying device further comprises a humidifying housing 6 which surrounds half of the air duct 1 and mates closely with the water channel 2 , wherein the water channel 2 surrounds the barrel-like outer wall of the air duct 1 and forms an inner humidifying housing 7 with the humidifying housing 6 ; and the water channel 2 is integrated with the inner humidifying housing 7 and surrounds the outer wall of the air duct 1 .
[0033] A slide rail is provided at the bottom of the inner humidifying housing 7 , and a slideway is provided at the bottom of the water channel 2 matching closely with the humidifying housing 6 , which slideway matches with and is slidably connected to the slide rail.
[0034] The humidifying device further comprises a humidifying top cover 5 provided on the top surface of the humidifying device, and a humidifying chassis 8 provided on the bottom surface of the humidifying device, and the air duct 1 penetrates through the humidifying top cover 5 and the chassis 8 .
[0035] The humidifying chassis 8 is provided with a lower power source interface 81 and a lower communication interface 83 at the bottom thereof, and the humidifying top cover 5 is provided with an upper power source interface 51 and an upper communication interface 52 .
[0036] In some optional embodiments, the inner wall of the water channel 2 surrounds the air duct 1 , and the water absorption filter element 3 is nested outside the inner wall of the water channel 2 by means of a groove. The water absorption filter element 3 functions to improve the evaporation efficiency and purify the water in the water channel 2 ; therefore, the water absorption filter element 3 is also designed to annularly extend along the air duct 1 to match with the annular structure in the water channel 2 so as to allow the air to pass through the water channel 2 and also to pass through the water absorption filter element 3 , thereby increasing the humidifying rate.
[0037] Further, in order to increase the area of the water absorption filter element 3 in contact with the wind, the water absorption filter element 3 is higher than the inner wall of the water channel 2 in designing the structure of the water absorption filter element 3 . The inner wall of the water channel 2 is lower than the outer wall, and the height of the water absorption filter element 3 is the same as the height of the outer wall; therefore, the area of the water absorption filter element 3 in contact with the wind throughout the humidification process comprises, in addition to the area of the upper surface, the area of a side wall of the water absorption filter element 3 that is higher than the inner wall.
[0038] Optionally, the water absorption filter element 3 may be designed to be tapered, and the structure of the inner wall of the corresponding water channel 2 may be configured accordingly.
[0039] In some illustrative embodiments, the water channel 2 is separate from the housing of the humidifying device, and the humidifying housing 6 is provided with a groove for having the water channel 2 placed therein.
[0040] The housing of the humidifying device comprises a humidifying top cover 5 , a humidifying housing 6 , an inner humidifying housing 7 and a humidifying chassis 8 . The inner humidifying housing 7 is fixedly connected to the humidifying housing 6 in such a manner as to be screw-connected, adhesive bonded or snap-fitted etc., the inner humidifying housing 7 is provided with a groove the structure of which matches with the water channel 2 , so that the water channel 2 can be freely detached from the housing of the humidifying device for the convenience of the user. The upper portion of the water channel 2 is then connected to the inner humidifying housing 7 via an upper connecting bar, and the lower portions of the inner humidifying housing 7 and the humidifying housing 6 are fixedly connected to the humidifying chassis 8 in such a manner as to be screw-connected, adhesive bonded or snap-fitted etc.
[0041] Furthermore, the bottom of the inner humidifying housing 7 is spaced from the humidifying chassis 8 by a certain distance, and a humidifying computer board (i.e. a humidifying PC) for controlling the humidifying device is provided in the gap between the humidifying casing 6 and the inner humidifying housing 7 ; the side of the inner humidifying housing 7 that is surrounded by the humidifying housing 6 may be fixed to the humidifying chassis 8 via a bolt and the bottom edge of the other side of the inner humidifying housing 7 may be connected to the humidification chassis 8 via the lower connecting bar.
[0042] Optionally, a slide rail may be provided on the groove of the inner humidifying housing 7 and a slideway may be provided in the corresponding position on the bottom of the water channel 2 to facilitate the removal of the water channel 2 more quickly and effortlessly.
[0043] Optionally, the humidifying top cover 5 is provided with an air outlet, the upper surface of the water absorption filter element 3 in the water channel 2 can be observed from the air outlet, that is, it is understood that the upper surface of the water absorption filter element 3 is exposed to the air, so that the diameter of the air outlet is prevented from being designed too small, hindering the evaporation and escaping rates of the water vapour.
[0044] Optionally, the humidifying top cover 5 is not disposed directly on the upper surface which is formed by the inner humidifying housing 7 and the upper connecting bar, and the humidifying top cover 5 is spaced from the upper surface at a distance in which a series of assemblies are provided, such as a power source interface and a communication interface. A lower power source interface and a lower communication interface are provided on the humidifying top cover 5 ; and similarly, a corresponding upper power source interface and upper communication interface are also provided on the humidifying chassis 8 . Therefore, it is necessary to provide an insulating cover for insulating the water vapour between the humidifying top cover 5 and the upper surface which is formed by the inner humidifying housing 7 and the upper connecting bar, and the humidifying top cover 5 is fixedly connected to the insulating cover. The lower power source interface, the lower communication interface, the upper power source interface and the upper communication interface may employ the structure of the first terminal block or the second terminal block of the connector as described above.
[0045] In some optional embodiments, the air duct 1 runs through the centre of the humidifying device and is also located in the centre of the water absorption filter element 3 .
[0046] Since the air duct 1 needs to pass through the whole humidifying device, the whole humidifying device can be regarded as a ring-like structure (in cross section), the shapes of the inner and outer rings may be the same or different, and the inner or outer ring may be of a round, square or triangular structure; and the humidifying device is preferably concentrically ring-shaped, i.e. the structure as shown in FIG. 3 , and this design is more conducive to ventilation and evaporation of the water vapour.
[0047] Optionally, the shape of the inner ring defines the structure of the air duct 1 , and the longitudinal section of the air duct 1 may be rectangular or be of other structures such as a trapezoid; for a better understanding, if the longitudinal section of the air duct 1 is rectangular, it is approximately understood that the air duct 1 is of a cylinder or cubic structure, and if the longitudinal section is a trapezoidal, the air duct 1 may be of a nearly circular cone structure.
[0048] Optionally, the humidifying device is provided with a connecting structure which is connected to the other devices as described above; the connecting structure may be a guiding structure, such as a guide groove and a guide post, the guide post and the corresponding guide groove of the respective devices being arranged to mate with each other, for example, a guide groove is provided on the humidifying top cover 5 , and a guide post is provided on the humidifying chassis 8 . In addition, a lower magnet and an upper magnet may be also respectively provided on the humidifying top cover 5 and the humidifying chassis 8 , so that the humidifying device is connected to other devices by means of attraction.
[0049] With the above embodiment, the following effects can be achieved: a simple structure, a good safety performance, no “white-powder” pollution, and easy to clean the device; and the principle of natural evaporation is adopted, such that the present invention is more green and healthy.
[0050] The description and the accompany drawings fully illustrate specific embodiments of the present invention so as to enable those skilled in the art to practice the same. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional, and the order of operations may vary, unless explicitly required. Portions and features of some embodiments may be included in or replace portions and features of other embodiments. The scope of the embodiments of the present invention encompasses the full scope of the claims, and all available equivalents of the claims. In this context, these embodiments of the present invention may be individually or collectively referred to by the term “invention” for convenience only, and if in fact more than one invention is disclosed, it is not intended to automatically limit that the application is within the scope of any single inventive or inventive concept. | A humidifying device, comprising an air duct ( 1 ) penetrating through the interior of the humidifying device, and a water absorption filter element ( 3 ) which is fitted over the top of an outer wall surrounding the air duct ( 1 ). According to the humidifying device, water is conveyed into the air duct ( 1 ) through the water absorption filter element ( 3 ) by means of the structural arrangement of a water channel ( 2 ) and the water absorption filter element ( 3 ), and humidifying operation is therefore carried out. | 5 |
This invention relates to knitting machines of the type comprising needle beds and yarn feeding means which circulate relative to one another, the needle beds having a non-knit zone, i.e., a zone in which the needles are inoperative or from which they have been removed or a zone which is not capable of receiving needles, means for severing the yarn in the non-knit zone, and means for presenting yarn to the first needle to knit following the non-knit zone.
A machine of the type referred to may be, for example, a circular knitting machine in which the beds (cylinder and dial) are stationary while the yarn feeding means rotates, or in which the beds rotate while the yarn feeding means is stationary, or a knitting machine having two (or more) stationary straight sections provided with needles, the straight sections being joined at their ends by arcuate needle-free sections. If the non-knit zone is a zone from which needles have been removed, its extent can be varied by adding or subtracting needles.
In known machines of the type referred to, the yarn is severed in the non-knit zone after every course of knitting, thus leaving fringe yarns at the edges of the fabric. The fabric edges tend to bow inwardly or laterally and this can cause difficulty. For example, the bowing of the fabric edges causes the wales in the fabric in the region of the edges to slope diagonally away from the needles, and in machines having means for transferring loops from one needle bed to the other, such slanting of the wales and consequential slanting of the loops on the needles makes transfer more difficult.
The present invention provides a knitting machine of the type referred to, in which the majority of courses are knitted with the yarn being severed in the non-knit zone, thus leaving a fringe of yarns along the edges of the fabric, and means for ensuring that, at spaced intervals, the yarn severing means is rendered ineffective so that the yarns are left unsevered in the non-knit zone, thus joining the edges of the fabric together at spaced intervals.
In another aspect, the invention provides a method of knitting a fabric on a knitting machine of the type referred to, the method comprising repeatedly severing yarn in the non-knit zone and presenting yarn to the first needle to knit following the non-knit zone, thus leaving a fringe of yarns along the edges of the knitted fabric, and periodically, after a plurality of courses have been knitted, allowing the yarn to remain unsevered in the non-knit zone, so that the edges of the knitted fabric are joined together at spaced intervals.
In a preferred embodiment the machine is a circular knitting machine having a stationary needle-cyclinder and a stationary needle-dial, the yarn being fed to the needles by one or more rotating yarn-feeders. A plurality of courses, preferably about twelve, are knitted with the yarn being cut every time it enters the non-knit zone and the yarn then being presented to the first needle to knit following the non-knit zone. Then, after the knitting of the next course, the yarn feeder is lowered as it passes the last needle to knit, but the yarn severing means is rendered ineffective and the yarn floats across the non-knit zone low enough to pass under the dial. This procedure is repeated to give a sequence of knitting in which a single yarn float is produced, for example, every twelve courses, in order to bridge the gap between the fabric edges. The resulting series of spaced floats maintains the fabric in a tube and inhibits bowing of the edges.
In the machine according to the invention, it may be advantageous to provide a guide plate for supporting the unsevered yarn or float joining the fabric edges, in order to maintain the fabric edges in a plane parallel to the axis of the fabric tube as they are cast off the needles. In a circular knitting machine, the guide plate may be rigid with the dial, e.g. being in the form of a flange, which may be arcuate. In the absence of such a flange the floats extend as chords between the fabric edges and might tend to slighly distort the loops on the needles adjacent the non-knit zone. The guide plate is preferably of sufficient extent (in the direction of motion of the fabric tube) to support a plurality of floats.
The yarn may be severed by a cutter associated with the yarn feeding means or a cutter associated with the non-knit zone. Cutting preferably occurs as soon as is practicable after the yarn has left the last needle to knit, since this maximizes the saving of yarn. The fringe yarns projecting from the edges of the fabric tend to be drawn into the fabric during knitting of subsequent courses, so it is usually desirable to provide devices for trapping the fringe yarns temporarily. A number of such devices are already known. However, the preferred device is that described in our U.S. Pat. No. 3,995,456: that device is mounted immediately following the last needle to knit or immediately preceding the first needle to knit and comprises a pair of yarn gripping jaws, one jaw being fixed, the other being radially movable and urged into contact with the fixed jaw by resilient means, and a cam-operated mechanism for temporarily moving the moveable jaw out of contact with the fixed jaw against the action of the resilient means in order to allow insertion of a fringe yarn between the jaws and release of a fringe yarn from the jaws. Whenever the yarn is left unsevered in order to form a float, the yarn is not inserted into the trapping device.
The knitting machine according to the invention will usually include means for drawing off the knitted fabric from the needle beds. Conveniently, the machine may include yarn trimmers arranged upstream of the drawing-off means so as to trim both the fringe yarns and the floats close to the terminal wales of the knitted fabric. The drawing-off means will usually act on the double-layer thickness of fabric, and the absence of one layer of knitted fabric (due to the non-knit zone) will result in a single-layer thickness being acted on by a lower drawing-off force. Preferably, then, the drawing-off means includes rolling means acting only in the region of a single-layer thickness of fabric. The rolling means may comprise an elongated roller or a series of co-axial rollers. The roller(s) may be mounted on a drive shaft and may comprise removable sleeves retained by longitudinally adjustable collars. The roller(s) or the collars may be adapted and arranged to provide guiding means cooperating with the fabric edges.
To facilitate trimming of the fringe yarns and floats of the fabric, needles may be removed or rendered inoperative near the non-knit zone in order to create, at each edge of the fabric, a "float wale" displaced inwards about, for example, two needle-pitches from the fringe yarns. The fabric can then be trimmed along the "float wales".
The invention will be described further, by way of example only, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagrammatic general view of a circular knitting machine according to the present invention.
FIG. 2 is a fragmentary perspective view of a non-knit zone of the machine.
FIG. 3 shows one of the yarn feeding units of the machine.
FIG. 4 is a section on line IV--IV of FIG. 1, showing a drawing-off device.
FIG. 5 is a fragmentary view of an auxiliary roller of the drawing-off device.
FIG. 6 is a view similar to FIG. 3 showing some additional components.
DETAILED DESCRIPTION
The circular knitting machine illustrated has a stationary needle cylinder 1 with verge walls 1a, needle tricks 1b, and needles 2. Above and within the needle cylinder circle is situated a stationary dial having similar verge walls and slots carrying dial needles 3. Yarn is fed to the needles from bobbins 29 by yarn feeding units 30, only one of which is shown in FIG. 1. The generally tubular knitted fabric 50 is drawn off over an oval fabric tensioning or stretching board 28 by a device 40 comprising pressure rollers 41a, 41b (FIG. 4).
The needle cylinder tricks 1b terminate at a level 1c below the verge walls 1a and there is thus a smooth cylindrical zone between the needle tricks 1b and the verge walls 1a. A trapping device 4 is located in this zone and is adjacent to the last needle to knit (needle 2') in an arc of needles (not shown). A similar trapping device 6 is located adjacent to the first needle to knit.
A tenon slot 5 is formed around the smooth cylinder zone of the needle cylinder 1 and the trapping devices 4 and 6 are mounted on the cylinder 1 by means of this slot. The trapping device 4 includes a support plate 7 secured by the screws 8 to a tenon (not shown) fitted in the slot 5 thus locking the plate 7 to the needle cylinder 1 in a releasable manner allowing circumferential positioning of the trapping device.
An intermediate plate or jaw 11 having a raised, corrugated clamping zone 11a comprising vertical ridges can move to and fro between the fixed plate 7 and a front plate or jaw 13 rigid with the plate 7.
The mechanism for moving the clamping jaw 11 radially comprises a blade-like element 15 (which is inserted in a needle trick as shown in FIG. 2) having an integral or rigid block 16 from which a rod 17 projects laterally. The rod 17 is located in the clamping jaw 11 and thus by oscillating the element 15 on its fulcrum 15a, the clamping zone 11a can be caused to move into and out of contact with the fixed jaw 13. A spring 18 is located in the tenon slot 5 and serves (via the block 16) to urge the clamping zone 11a into contact with the jaw 13. For opening the jaws, a butt 15b is provided on the element 15, which can be contacted by a cam 20 rotating with the yarn feeding unit, whereby the element 15 is rocked back into the needle trick thus further compressing the spring 18. To prevent the spring 18 forcing the element 15 out of its trick when the clamping zone 11a is pressed against the jaw 13, an arm 23 secured to the support plate 7 by the screws 8 projects in front of the element 15 and block 16 to limit movement of the block 16.
In FIG. 3 part of the trapping device 4 is shown in conjunction with the last needle 2' to knit and a conventional yarn feeding unit 30. This unit 30 has yarn feeders (only two of which, 31, 32 are shown) which can each be supplied with yarn, the feeder 31 being shown in the raised (operative) position, the feeder 32 being in the lowered (inoperative) position. The feeders are selected by stationary cams (not shown) cooperating with cam followers 33 on the rotating yarn feeding unit, and are withdrawn by slides 34 cooperating with fixed cams (not shown).
The yarn 21 coming from the last needle 2' is seen in FIG. 3. The yarn 21 has been fed to the needles by the feeder 32 which, before passing the trapping device, was in the operative position. As the feeding unit 30 passes the trapping device, the jaws 11, 13 are opened by the cam 20. Subsequently, the yarn 21 is lowered by the feeder 32 and is pushed down between the jaws 11, 13 by a placer 35 actuated through a linkage 36 by a slide 37 operated by a cam. A cutter 38 descends at the same time as the placer 35 and cuts the yarn 21 so as to leave a fringe yarn which is immediately afterwards gripped between the jaws 11, 13 as the butt 15b (FIG. 2) is released by the cam 20. Whenever the jaws 11, 13 are out of contact, the preceding fringe yarns are free to escape into a permanent recess between jaws 11, 13 (defined by a spacer 12 -- FIG. 3) from where they freely move up under the effect of the continuous downward and radially inward movement of the knitted fabric.
The above described severing and trapping procedure is performed for twelve successive courses of knitting, and at the end of the twelfth course the yarn is trapped and severed as the yarn feeding unit passes the last needle to knit. The yarn placer 35 is raised as the feeder unit passes the non-knit zone. The thirteenth course is commenced (on the first needle following the non-knit zone) by the yarn feeder 32 being raised to introduce its yarn to the needles and knitting of the thirteenth course proceeds. Now in order to ensure that the yarn placer does not lower the yarn as the feeder unit passes the last needle to knit the placer is lowered prematurely by an auxiliary control cam 39 (FIG. 6) which is brought into action by means of a stud on a control chain (not shown). This cam 39 operates upon the slide 37 which causes the yarn placer 35 and cutter 38 to move to the position shown in FIG. 6.
The placer and cutter are held in this position by means of a spring loaded latching member 39a. It should be noted that if a single yarn feeding unit having a latch member 39a makes a specified number of revolutions around the needle cylinder, a specified number of knitted courses are produced, together with their cut fringe yarns at the needle free zone as follows. The auxiliary cam 39 is kept down in a low position. The slide 37 is advanced by a permanent cam which is situated adjacent the commencement of the needle free zone, thus the yarn placer 35 and the cutter 38 are operated to cut the yarn each time the unit enters the needle free zone. The latching member 39a is active at each advance of slide 37, but is unlatched after each cutting and trapping operation. Therefore, if a machine is provided with only one feeding unit 30 and a floated yarn is required after every specified number of courses, then the auxiliarly cam 39 will be raised to active position as shown in FIG. 6 prior to the commencement of the next course. It should be mentioned that this action takes place upon only one selected yarn feeding unit 30, and the placer and cutter are held in this position while the feeding unit travels around the needle cylinder. When the feeding unit 30 reaches the start of the non-knit zone, the feeder 32 is lowered from the operative position to the position shown in FIG. 6. As the placer 35 has already been lowered (prematurely) to the position shown in FIG. 6, the yarn 21 extending from the last needle 2' is not taken down into the trapping and severing means, the feeding unit 30 continues to supply yarn while traversing the needle free zone thus forming a float 51 which passes under the periphery of the dial. A fixed cam (not shown) is used to operate upon the latching member 39a for releasing the slide 37 and thereby resetting the placer 35 and cutter 38 before the severing and trapping procedure commences.
The severing and trapping procedure is then repeated for the next 12 courses, before another single float 51 is formed. The floats 51 are supported by an arcuate guide plate 52 which is fixed to the underside of the dial by brackets 53 (only one shown) and extends across the whole of the non-knit zone. The external surface of the plate 52 slopes inwardly and downwardly in its upper part, while the lower part is vertical.
To facilitate subsequent trimming of the knitted fabric, longitudinal unlooped zones, which can conveniently be termed "float wales" 54 are formed near the edges of the fabric (FIG. 1) by removing needles from a position about two needle-pitches inwards from the non-knit zone. One such position is indicated at X in FIG. 2; needles would also be removed from the equivalent position in relation to the needle 2'.
Immediately after passing over the stretching board 28 the fabric 50 is trimmed by cutters 56 along the respective float wales 54. The fabric 50, initially generally tubular, is flattened as it passes through the drawing-off device 40 (FIGS. 1, 4 and 5) which is directly below the stretcher board 28. The double-layer thickness of fabric is acted on by the two driven pressure rollers 41a, 41b on one side and a driven counter-roller 42 on the other side. Rolling means in the form of an elongated roller 43 on a driven shaft 44 act on the single-layer thickness of fabric, in conjunction with the counter-roller 42. The shaft 44 is rotated by a co-axial driven gear 46 rigid with a stub axle 47 releasably connected to one end of the shaft 44 by a transverse bolt 48; the other end of the shaft 44 is similarly connected to a stub axle.
The roller 43 comprises removable segments or sleeves 43a, keyed on the shaft 44, and a pair of collars 43b which retain the sleeves 43a on the shaft and are themselves retained by respective set-screws 49. As can be best seen in FIG. 1, the axially outer surfaces of the collars 43b serve as means for guiding the trimmed edges of the fabric 50.
Various modifications may be made within the scope of the invention. In particular, the number of fringe yarns and floats can be varied, as can the ratio between these two numbers; for example, there may be more than twelve fringe yarns between the floats. It is also permissible to provide more than one successive course with floats, although this is unlikely to provide any advantage over a single float. | In a knitting machine the needle beds and yarn feeders circulate relative to one another. This normally produces a tubular fabric. In order to leave a gap in the tube, a zone of each needle bed is arranged as a non-knit zone. To save yarn the yarns are not normally allowed to float across the gap, but are severed and trapped. To hold the edges straight, periodic yarns are allowed to float across the gap. | 3 |
RELATED APPLICATION
This application is a continuation-in-part of Serial No. 551,573, filed Nov. 14, 1983.
SUMMARY OF THE INVENTION
A primary object of this invention is to provide a closure for double pipe and hairpin heat exchangers that permits the tube side of the closure to be opened for maintenance and/or repair without losing the shell side fluids seal and has particular adaptability to situations where the shell side fluids are of hazardous or corrosive fluids.
In particular, the closure is directed to use with heat exchangers of the type having a shell side enclosure and at least one tube within the shell. That is, heat exchangers of the hairpin type having one single tube or a plurality of tubes therein. The closure comprises a shell side flange attached to the end of the shell and a tube sheet encompassing the tube or tubes and situated within the shell adjacent the end to be closed. The tube sheet has a peripheral threads therein. A tubular connection formed of a tube and flange is provided in facing alignment with a thrust flange and the shell flange. The thrust flange of the invention is threaded and is positionable between the shell and tube flanges. The thrust flange surrounds the tube sheet and includes peripherial threads for interconnection with the threads on the tube sheet. Seals are provided between the tube sheet and the shell flange and between the tube flange and the tube sheet. A plurality of axially aligned openings are provided in the shell, tube and thrust flanges to receive connection bolts which are used to assemble the closure. Interconnection is made between the bolts and the thrust flange by a variety of mechanisms including a threaded connection, a nut or sleeve abuttable against the thrust flange for drawing the thrust and shell flanges together.
Another object of the invention is to provide a closure that will allow separate hydrostatic testing of the shell side with the tube side flange removed and/or hydrostatic testing of the tube bundle when removed from the shell.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is elevation, partly in section, of a hairpin-type heat exchanger which includes in this embodiment a single inner tube surrounded by an outer tube or shell, which heat exchanger includes closure elements constructed in accordance with this invention.
FIG. 2 is a vertical longitudinal section view through a closure embodying this invention.
FIGS. 3, 4 and 5 are partial sectional views of alternate embodiments incorporating the concepts of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The heat exchanger exemplified in FIG. 1 is of the hairpin-type comprising a straight tube 10, a return bend 12 connecting with another straight tube 14 shown in dotted line. Although a single tube construction has been shown, the invention herein encompasses the use of a plurality or bundle of hairpin-shaped tubes. The inner tube is enclosed by a substantially co-axial shaped shell 16 defining the shell side space 18. The shell includes a similar return bend portion 20 interconnecting with straight shell 21. The shell side fluids 22 are caused to flow through inlet connection 24 with their exit therefrom through outlet 26 as shown by arrow 28. The side fluids or are caused to enter through tubing 30 and exit through tubing 32. The direction of flow of fluids is not critical to this invention. The closure of this invention for effecting a seal between the shell side and the tube side is identical for both the inlet and outlet and is generally designated by the numeral 40.
In FIG. 2, the closure 40 of this invention is specifically described relative to a bundle of tubes generally at 42 comprised of a plurality of tubes 44, which are encompassed by a tube sheet 46. The tube sheet 46 is situated adjacent the end of the shell 16 and shell flange 48. The flange may include an interior bevel surface 50 to accomodate or receive a seal ring 52, which may be of any suitable type as known in the art. The purpose being to provide a wedge surface abuttable against the beveled surface 50 to seal the shell side fluids between the space 18 and the tube sheet 46. The shell flange includes a plurality of circumferentially spaced openings 54 to receive a threaded bolt 56 or stud bolt such as shown in FIGS. 3, 4 and 5. The tubular connection 32 includes a tube flange 60 which faces, in alignment with the shell flange 48 and includes a plurality of circumferentially spaced openings 62, which when the closure is assembled, are in axial alignment with the openings 54 of the shell flange 48 for receiving longitudinal bolts or studs 56 therethrough. The tube flange 60 includes an inset 64 to receive a seal ring 66 and thus seal the interior space 33 of the tube 32. A thrust flange 70, with wrench grooves 71, is positionable between the shell flange 48 and the tube flange 60. The thrust flange surrounds the tube sheet 46 and includes inner peripherial threads 72 for interconnection with the threads 47 formed in the periphery of tube sheet 46. The thrust flange includes a plurality of axially aligned openings 74 in this embodiment threaded to accept and receive the threaded portion of bolt 56. The closure is assembled by inserting the seal ring 52 into position relative to the beveled recess 50 about the tube sheet 46. Thrust ring 70 is then threadably interconnected to the tube sheet and bolts 56 are threaded thereto which, upon rotation, will draw the thrust ring 70 toward the shell flange 48 compressing the ring 52 to seal the shell side space between the tube sheet 46 and shell 16 and its attached flange 48. Thereafter the tube 32 and its associated tube flange 60 are positioned with the bolts 56 extending therethrough openings 62. A nut 80 is threaded to the exposed end, compressing seal 66, which has been previously positioned and thus providing a compressive connection to assembly the closure.
In the event it is desirable to repair, inspect and/or clean the interior of the tubes 44, nuts 80 are removed allowing the tube 32 and its associated flange 60 to be removed. In most heat exchange connections there is a spaced connection with tubing 32, not shown, which upon disconnecting allows the removal of the tubing stub or spool 32 and flange 60 for access to the tubing interior.
The embodiment of FIG. 3 is substantially identical to the major components shown in FIG. 2 with like parts utilizing like numerals. Tube sheet 46 includes outer peripherial threads 47 therein to accept threaded thrust ring 90 which, in this embodiment, includes a plurality of axially aligned openings 92 to receive the threaded stud 96. The threaded stud includes flattened end portion 98 and 100 for a wrench or other tools. Tube flange 102 includes a plurality of circumferential spaced axial openings 104 and in this embodiment, a recess 106. During the assembly thereof the threaded stud 96 is inserted through the openings 54 and 92 of the respective shell flange 48 and thrust flange 90. Nut 110 is threaded upon the stud to abut against the outside of shell flange 48. Nut 112 is threaded upon the stud 96 to abut against the thrust flange 90. By turning one or both of nuts 110 and 112 relative to stud 96 the thrust flange 90 is caused to draw towards the shell flange and seal the shell side space 18 as previously described. Tube flange 102 is assembled with the studs 96 projecting therethrough. Nuts 114 are threaded upon the studs 96 to abut against the tube flange 102 for the assembly as similarly described to compress seal ring 66 between the tube flange 102 and the tube sheet 46.
In the embodiment of FIG. 4 the respective shell flange 48, thrust flange 90 and tube flange 102 are essentially identical to that shown in FIG. 3. The change is directed to the bolt or stud 120 which includes flats or wrench surfaces 122 on one end and 124 on the other. In this embodiment there is a threaded section 126 adjacent the shell flange end and a threaded portion 128 adjacent to the tube flange end. An enlarged sleeve 130 formed as a part of the stud abuts against the thrust flange 90 as shown. In the assembly the thrust flange and assembled tube sheet 46 is caused to move toward the shell flange by the relative rotation of nut 132 to stud 120, drawing the two together and causing compression of the sealing ring 52 against the beveled surface 50 and the tube sheet 46 to seal the shell side space 18. Thereafter the tube flange 102 is assembled using nuts 134 to compress the seal ring 66 against the tube sheet 46.
A further embodiment is shown in FIG. 5, the only change being in the bolt or stud 150, having a wrench or flat 152 on the shell side and flat 154 on the tube side. In this embodiment the stud 150 includes a threaded portion 156 adjacent the shell flange 48 side. The threaded portion 156 extends through the thrust ring 90 to an enlarged threaded portion 158. The tube flange 102 has enlarged openings 160 to receive the larger diameter portion 158. The enlarged threaded portion includes a shoulder 162 for abutment against the thrust flanges 90. The assembly is similar to that in FIG. 4, wherein nuts 164 operating against the shell flange 48 will draw the thrust flange 90 toward the shell flange 48 perfecting the seal as previously described. Thereafter nut 166 will draw the tube flange 102 toward the tube sheet 46 compressing sealing ring 66 therebetween. Tube flange 102 does not necessarily need to be recessed as shown at 106 of FIG. 4. | Closures for double pipe and hairpin-type heat exchangers that permits opening the tube side of the closure without losing the shell side fluids or seal. A threaded thrust ring is positioned between the shell side flange and the tube side flange and integrally connected with the tube sheet. Each connection bolt through the flange has a shoulder or threads interconnecting with the thrust ring for applying a force to maintain the seal between the shell side flange and the tube sheet. | 5 |
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 14/201,745, filed Mar. 7, 2014, which is a continuation of U.S. patent application Ser. No. 13/222,153, filed Aug. 31, 2011, which patent applications are incorporated herein by reference in their entirety.
BACKGROUND
Embodiments of the invention relate to data storage systems, and more particularly, to configuring a virtualization controller in a data storage system without disrupting current I/O operations.
A virtualization controller is a network based storage virtualization system for managing large amounts of heterogeneous data storage in an enterprise data center. The tasks of deploying a virtualization controller in a storage network configuration and using virtual data storage (e.g., virtual disks or volumes) generally require an administrator to stop IO operations to existing disks or logical data storage units (LUNs). Such I/O operations may come from applications running on a host computer.
What is needed is a method and system for configuring a virtualization controller in a data storage system without disrupting I/O operations to existing data storage units.
SUMMARY
Exemplary embodiments of the invention relate to configuring a virtualization controller in a SAN data storage system without disrupting I/O operations between the hosts and the data storage devices.
One aspect of the invention concerns a method that comprises establishing a first data path between a host and a storage controller where the host and storage controller are in the same communication zone and the storage controller comprises disks for storing data; adding a virtualization controller to the zone wherein the virtualization controller maps the disks to virtual volumes and establishes a second data path between the host and the disks through the virtual volumes; removing the first data path; and performing I/O operations between the host and the disks through the second data path.
The details of the preferred embodiments of the invention, both as to its structure and operation, are described below in the Detailed Description section in reference to the accompanying drawings. The Summary is intended to identify key features of the claimed subject matter, but it is not intended to be used to limit the scope of the claimed subject matter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 illustrates an exemplary SAN data storage configuration in which methods and systems for adding a virtualization controller to the configuration without disrupting I/O operations may be provided, according to embodiments of the invention;
FIG. 2 illustrates a SAN data storage system that includes a virtualization controller in which exemplary embodiments of the invention may be implemented;
FIG. 3 illustrates an exemplary SAN data storage configuration that includes multiple data paths between a host and disks in which embodiments of the invention may be implemented;
FIG. 4 illustrates multiple logical data paths between a host and disks in a SAN data storage system in which a virtualization controller may create alternate data paths, according to an embodiment of the invention;
FIG. 5 illustrates the removal of a logical data path between a host and disks which allows I/O operations to fail over to an alternate data path through a virtualization controller, according to an embodiment of the invention;
FIG. 6 is a flowchart of a process for configuring a virtualization controller in a data storage system without disrupting data I/O operations between host systems and storage devices, according to an embodiment of the invention;
FIG. 7 is a block diagram of a computer that may be part of a host, network router, virtualization controller, or storage controller, according to an embodiment of the invention.
DETAILED DESCRIPTION
The invention relates to methods, systems, and computer program products for configuring a virtualization controller in a SAN data storage system without disrupting I/O operations between the hosts and data storage devices. The invention is described in exemplary embodiments with reference to the Figures, in which like numbers represent the same or similar elements. It will be appreciated by those skilled in the art that variations may be accomplished in view of these teachings without deviating from the spirit or scope of the invention.
Data virtualization is a technology that makes one set of resources look and feel like another set of resources, preferably with more desirable characteristics. The virtualized resources are a logical representation of the original resources that are not constrained by physical limitations, variations, and complexity. A storage virtualization shifts the management of data storage from physical volumes of data to logical volumes of data, and may be implemented at various layers within the I/O stack such as at the disk layer and at the file system layer. A virtualization at the disk layer is referred to as a block-level virtualization or a block aggregation layer. A block-level virtualization may be implemented at any of the three storage domain layers: hosts, storage network (e.g., storage routers and storage controllers), and storage devices (e.g., disk arrays).
For data storage, virtualization may include the creation of a pool of storage that contains several disk systems. The pool can be organized into virtual disks (Vdisks) or image-mode disks that are visible to the host systems using the disks. Vdisks can use mixed back-end storage and provide a common way to manage a storage area network (SAN).
An example of data storage products that provide block-level virtualization is the IBM® SAN Volume Controller (SVC) product model 2145. A SAN virtualization system may be implemented as a clustered appliance in the storage network layer. A fundamental concept of data storage virtualization is to decouple data storage from the storage functions required in a storage area network (SAN) environment. Decoupling means abstracting the physical location of data from the logical representation of the data. A storage virtualization device may present logical entities to the users and internally manage the process of mapping these entities to the actual location of the physical storage. The actual mapping performed is dependent upon the specific implementation, as is the granularity of the mapping, which can range from a small fraction of a physical disk, up to the full capacity of a physical disk.
A single block of information in this environment is identified by its logical unit number (LUN) which is the physical disk, and an offset within that LUN which is known as a logical block address (LBA). The term physical disk is used in this context to describe a unit of storage that might be part of a RAID array in the underlying disk subsystem. Specific to a SAN virtualization controller implementation, the address space that is mapped by the logical entity is referred to as volume, and the physical disk is referred to as managed disks (e.g., Mdisks).
The server and application are only aware of the logical entities, and may access these entities using an interface provided by the virtualization layer such as the SCSI interface. The functionality of a volume that is presented to a server, such as expanding or reducing the size of a volume, mirroring a volume, creating a FlashCopy®, thin provisioning, and so on, is implemented in the virtualization layer. It does not rely in any way on the functionality that is provided by the underlying disk subsystem. Data that is stored in a virtualized environment is stored in a location-independent way, which allows a user to move or migrate data between physical locations, referred to as storage pools.
A block-level storage virtualization in a SAN virtualization controller provides many benefits such as allowing online volume migration while applications are running, simplifying storage management by providing a single image for multiple controllers and a consistent user interface for provisioning heterogeneous storage, and providing enterprise-level copy services functions. In addition, storage utilization can be increased by pooling storage across the SAN, and system performance is improved as a result of volume striping across multiple arrays or controllers and the additional cache that a SAN virtualization controller provides.
A SAN virtualization controller may manage a number of back-end storage controllers or locally attached disks and map the physical storage within those controllers or disk arrays into logical disk images or volumes, which are seen by application servers and workstations in the SAN. The SAN may be zoned so that the application servers cannot see the back-end physical storage, which prevents any possible conflict between the SAN virtualization controller and the application servers both trying to manage the back-end storage.
Each virtualization controller hardware unit may be referred to as a node. The node provides the virtualization for a set of volumes, cache, and copy services functions. Storage nodes in a virtualization controller may be deployed in pairs and multiple pairs make up a cluster. In current virtualization controllers, a cluster may consist of multiple node pairs or I/O groups. All configuration, monitoring, and service tasks in a virtualization controller may be performed at the cluster level. Configuration settings may be replicated to all nodes in the cluster.
The cluster and its I/O groups may view the storage that is presented by back-end controllers as a number of disks or LUNs, known as managed disks or Mdisks. An Mdisk is usually provisioned from a RAID array. The application servers, however, do not see the Mdisks. Instead they see a number of logical disks, known as virtual disks or volumes, which are presented by the cluster's I/O groups through a SAN (e.g., through a Fibre Channel protocol) or LAN (e.g., through an iSCSI protocol) to the servers. Each Mdisk presented from an external disk controller has an online path count that is the number of nodes having access to that Mdisk. The maximum count is the maximum paths detected at any point in time by the cluster.
Volumes are logical disks presented to the hosts or application servers by a virtualization controller. When a host performs I/Os to one of its volumes, all the I/Os for a specific volume are directed to one specific I/O group in the cluster. The virtualization controller may present a volume to a host through different ports in the virtualization controller, thus providing redundant paths to the same physical storage devices. Redundant paths or multi-paths establish two or more communication connections between a host system and the storage device that it uses. If one of these communication connections fails, another communication connection is used in place of the failed connection. The allocation and management of the multiple paths to the same storage devices may be handled by multi-path software.
The multi-path software may monitor host storage initiator functions where storage I/Os originate and where communications failures are identified. The multi-path software typically runs in the kernel space of the host systems, e.g., as multi-path drivers. There are various ways for implementing the multi-path drivers, depending on the operating system. Some operating systems may provide application programming interfaces (APIs) for integrating third-party multi-path software. For example, the multi-path drivers may be implemented between a SCSI command driver and a low-level device driver.
Today when a virtualization controller is added to a data center to provide storage virtualization, one possible configuration process is to virtualize back-end disks using a virtualization controller and expose the newly created virtual disks to the host (by an appropriate zoning and LUN mapping). The operator may need to change the application configuration files on the host to use the newly exposed virtual disks, then stop and restart the application to use the new virtual disks. In this process, the operation of the data center is disrupted as the applications must be stopped and restarted in order to insert the virtualization controller into the data paths. This disruption may be the same for other virtualization devices similar to a virtualization controller. Embodiments of the invention eliminate this disruption by allowing I/O operations to fail over to alternate data paths through a virtualization controller, transparently to the applications running in the hosts.
Referring now to the drawings and in particular to FIG. 1 , there is illustrated an exemplary SAN based data storage system in which methods and systems for configuring a virtualization controller may be provided according to embodiments of the invention. The methods and systems disclosed herein may be applicable to a wide variety of different computers, servers, storage systems, and networks in addition to the illustrated configuration. The computing configuration 100 may comprise one or more host computers 101 - 102 from which users and applications may access data stored on disks 106 - 108 (d 1 , d 2 and d 3 ), or other data storage devices such as solid state memories, optical discs, and magnetic tape drives.
Host computers 101 - 102 may include CPUs (Central Processing Units) and memory for executing various programs, thereby providing a variety of computing functions to users and applications. For example, host computers 101 - 102 may be servers that host applications to provide Web services and database services to users and applications.
The disks 106 - 108 may be part of a storage controller 105 which is connected to the hosts 101 - 102 through a storage area network (SAN) fabric 104 . The SAN fabric 104 may comprise one or more network routers and network controllers, and be supported by an Fibre Channel channel interface protocol or other interface protocols.
Data storage controller 105 may comprise one or more controllers, disk arrays and tape libraries. For example, the data storage controller 105 may comprise IBM® System Storage® DS8000®. The 58000® systems are high-performance, high-capacity storage controllers providing disk storage that is designed to support continuous operations. The storage controllers may include host adapters for interfacing with host computer 104 and device adapters for interfacing with attached storage devices such as disks and solid state drives. The host adapters may support various host-device interface protocols such as Fibre Channel (FC), Fibre Channel Arbitration Loop (FC-AL), Fibre Channel over Ethernet (Foe), Internet Small Computer System Interface (iSCSI), etc.
Data storage controller 105 may comprise hard disk drives, solid state drives, arrays of hard disk drives or solid-state drives, tape drives, tape libraries, CD-ROM libraries, or the like. Further, data storage controller 105 may comprise multiple levels such as a primary level of solid state storage, a secondary level of disk storage, and a third level of tape libraries.
FIG. 2 illustrates a SAN data storage system that includes a virtualization controller for providing storage virtualization functions and exemplary embodiments of the invention. As in the storage configuration of FIG. 1 , the hosts 201 - 202 are connected to data storage devices 206 - 208 , which may be part of a storage controller 205 , through a SAN fabric 204 . A virtualization controller 210 may be coupled to the SAN fabric 204 and to the storage controller 205 through a second SAN fabric 211 . Each of the SAN fabrics 204 and 211 may comprise one or more network controllers, communication interfaces, and respective communication protocol implementations such as Fibre Channel and iSCSI protocols.
The virtualization controller 210 and hosts 201 - 202 may be viewed as being in the same “ ” for communication purposes. In a storage area network (SAN), zoning is the allocation of resources for device load balancing and for selectively allowing access to data only to certain users. Essentially, zoning allows an administrator to control who can see what in a SAN. Zoning may be achieved using a structure similar to that of a computer file system. A zone is the equivalent of a folder or directory. Zoning can be either hard or soft. In hard zoning, each device is assigned to a particular zone, and this assignment does not change. In soft zoning, device assignments can be changed by the network administrator to accommodate variations in the demands on different servers in the network. The use of zoning minimizes the risk of data corruption, viruses and worms, and minimizes the time necessary for servers to reboot.
With the virtualization controller 210 and hosts 201 - 202 being in the same zone, the virtualization controller 210 may create virtual disks 1 , 2 , and 3 ( 212 - 214 ), which may respectively correspond to physical disks 1 , 2 , and 3 ( 206 - 208 ), and expose the virtual disks 1 , 2 , and 3 ( 212 - 214 ) to hosts 201 - 203 . For example, the virtualization controller 210 may map virtual disk 1 ( 212 ), which corresponds to physical disk 1 ( 206 ) to host system 201 . Virtual disks 1 , 2 , and 3 ( 212 - 214 ) are also referred to as volumes or virtual image mode disks.
FIG. 3 illustrates an example of a SAN data storage configuration in which a virtualization controller maps physical disks into virtual disks and creates alternate data paths between a host and disks, for which embodiments of the invention may be provided. For clarity, only one host 1 , one SAN fabric, and one physical disk 1 are shown in FIG. 3 . Host 1 ( 301 ) is coupled to SAN fabric 304 by connection 320 . A virtualization controller 310 is also coupled to the SAN fabric 304 by connection 321 , and storage controller 305 is coupled to the SAN fabric 304 by connections 322 - 323 . As illustrated in FIGS. 1 and 2 , the virtualization controller 310 may create three cache-disabled image mode virtual disks 1 , 2 and 3 ( 312 - 314 ), which are respectively mapped to physical disks 1 , 2 and 3 ( 306 - 308 ). The virtualization controller 310 may further expose the virtual disk 1 ( 312 ) to host 1 ( 301 ) as shown in FIG. 3 . With the presence of the virtualization controller 310 in the illustrated SAN storage configuration, there are now more than one data paths between host 1 ( 301 ) and the physical disks 306 - 308 in the storage controller 305 . These multiple data paths are logical data paths and are illustrated in more detail in FIG. 4 .
FIG. 4 illustrates multiple logical data paths between host 1 ( 301 ) and disks 406 - 408 . The first logical data path 430 is through connection 420 between host 1 ( 401 ) and SAN fabric 404 , and connection 422 between the SAN fabric 404 and storage controller 405 . This is the only data path that the host 1 ( 401 ) may use to access the physical disks 406 - 408 in the storage controller 405 when the virtualization controller 410 is not present in the configuration.
With the addition of the virtualization controller 410 , the host 1 ( 401 ) may now access data in the physical disks 406 - 408 through a second logical data path 431 . The second logical data path 431 is established through three connection segments: segment 424 between host 1 ( 401 ) and SAN fabric 404 , segment 421 between SAN fabric 404 and virtualization controller 410 , and segment 423 between the SAN fabric 404 and storage controller 405 . The multiple logical data paths 430 and 431 may be identified by a multi-path driver 433 in the host 1 ( 401 ). This identification is possible because the image mode virtual disks 1 , 2 , and 3 mimic the SCSI-3 unique LUN Identifiers of the physical disks 1 , 2 , and 3 , respectively. The multiple logical data paths 430 - 431 between host 1 ( 401 ) and storage controller 405 allow the host 1 ( 401 ) to perform I/O operations on physical disks 406 - 408 through any of the logical paths 430 - 431 .
FIG. 5 illustrates the removal of a direct data path 530 between host 1 ( 501 ) and storage controller 505 in a SAN storage configuration to allow I/O operations to fail over to an alternate data path 531 through a virtualization controller 510 . In an exemplary embodiment of the invention, once the virtualization controller 510 establishes a logical data path 531 between host 1 ( 501 ) and storage controller 505 , the SAN configuration may perform a “zoning-out” operation to remove the data path 530 between the host 1 ( 501 ) and the storage controller 505 . All I/O operations between the host 1 ( 501 ) and disks 506 - 508 will now automatically fail over to the second logical data path 531 which is through the virtualization controller 510 .
Fail-over is an operational mode in which the functions of a system component (such as a processor, server, network, or database) are assumed by secondary system components when the primary component becomes unavailable. The procedure involves automatically offloading tasks to a standby system component so that the procedure is as seamless as possible to the end user. Fail-over can apply to any aspect of a system or network such as a connection path or a storage device. Storage networks may use many paths between a host and a storage system. The capacity for automatic fail-over means that normal functions can be maintained despite any changes or interruptions in the network configuration.
In an embodiment of the invention, a storage configuration utility may disable a data caching function in the virtualization controller 510 that provides caching of the image mode volumes (e.g., virtual disk 1 ) when a virtualization controller is introduced into the data storage system. Such a disabling of the data caching prevents data corruption that may result during the configuration of the virtualization controller. In a typical operation, when a host multi-path driver detects two active paths to the same disk, it can send data through both paths in a round robin fashion. If caching were enabled on the virtualization controller 510 , a write command from the host 1 may cause a data caching on virtualization controller 510 . This means that the back-end storage controller 505 does not contain the data that is written to disks (as the data is still cached on the virtualization controller 510 ).
Since the multi-path driver on the host 1 ( 501 ) may determine that the two data paths lead to the same disk, it can subsequently issue a read command to the storage controller 505 directly on the same data block that was written earlier. This operation will return the old (and therefore incorrect or stale data) because the latest data is still cached on virtualization controller 510 and the storage controller 505 never received the last write command. The described scenario is an example of the data corruption that may occur if caching is enabled in the virtualization controller 510 .
With data caching disabled in the virtualization controller 510 , all data written to the virtual disk 1 ( 512 ) will go directly through data path 531 and virtualization controller 510 to the back-end storage controller 505 and the physical disk dl ( 506 ). Hence, a subsequent read command via the direct path from host to the storage controller 505 that contains disk 1 ( 506 ) will receive the latest data.
Once I/O operations between the host 1 ( 501 ) and storage controller 505 have failed over to the alternate data path 531 through the virtualization controller 510 , data caching in the virtualization controller 510 may be enabled again for caching the image mode data volumes, e.g., volume 1 ( 512 ). The virtualization controller 510 has thus been added to the data storage configuration illustrated in FIG. 5 without disrupting I/O operations between the host 1 ( 501 ) and the disks 506 - 508 of the storage controller 505 .
FIG. 6 is a flowchart of an exemplary process for configuring a virtualization controller 510 in a data storage system without disrupting I/O operations between host systems and storage devices, according to an embodiment of the invention. At step 601 , a host may be directly connected to a storage controller, i.e., the host and storage controller are in the same zone. An operator may add a virtualization controller 510 to the data storage configuration, at step 602 , where the virtualization controller 510 is zoned with the storage controller 505 . The virtualization controller 510 may set up a one-to-one mapping of the disks 506 - 508 in the storage controller 505 to virtual or image mode disks 512 - 514 that the virtualization controller 510 creates, at step 603 . In one embodiment, the virtual disks 512 - 514 may respectively mimic the SCSI-3 unique identifiers of the storage controller disks 506 - 508 .
At step 604 , the virtualization controller 510 may disable its data caching function so that data of the virtual disks 512 - 514 are not cached, to avoid data corruption in the storage system. The virtualization controller 510 is now zoned with the host 501 , and the physical disks 506 - 508 in the storage controller 505 are respectively mapped to the host 501 as virtual disks 512 - 514 , as shown by step 605 . At step 606 , the host multi-path drivers 533 may now recognize the virtual disks 512 - 514 as alternate data paths between the hosts ( 501 ) and the disks in the storage controller ( 505 ). The process may further remove the zones (i.e., data paths) that allow direct communication between the hosts and storage controllers, at step 607 .
Multi-path drivers in the hosts automatically fail over to the alternate data path through the virtual disks established by the image mode of the virtualization controller 510 , at step 608 . The process may subsequently enable data caching of the virtual disks in the virtualization controller 510 , at step 609 . The virtualization controller 510 has thus been added to the data storage system without disrupting I/O operations between the hosts 501 and the data storage controllers 505 , as shown by step 610 .
FIG. 7 illustrates a block diagram of a computer that may be part of a host, network router, virtualization controller, or storage controller, in accordance with an embodiment of the invention. Computer 700 may include a processor 701 , a memory 702 , a persistent storage 703 , a communications unit 704 , an input/output unit 705 , a display 706 , and system bus 707 . As an example, processor unit 701 may include one or more processing cores and computer memory 702 may comprise EEPROM memory modules. Communications unit 704 may include network interface adapters, modems and support software. Input/output unit 705 may include a keyboard, mouse, and printer. Persistent storage 703 may comprise a hard disk drive or an optical disk drive.
Computer programs are typically stored in persistent storage 703 until they are needed for execution, at which time the programs are brought into memory unit 702 so that they can be directly accessed by processor unit 701 . Processor 701 selects a part of memory 702 to read or write based on an address in memory 702 provided along with a read or write request. Usually, the reading and interpretation of an encoded instruction at an address causes processor 701 to fetch a subsequent instruction, either at a subsequent address or some other address.
An operating system runs on processor unit 701 to coordinate and control various components within computer 700 and to perform system tasks required by applications running on the computer 700 . The operating system may be a commercially available or open source operating system, as are well known in the art.
Instructions for the operating system and applications or programs may be stored are located on storage devices, such as a hard disk drive 703 . These instructions and may be loaded into main memory 702 for execution by processor 701 . The processes of the illustrative embodiments may be performed by processor 701 using computer implemented instructions, which may be located in memory 702 . Some of the processes may read from or write data to a data storage device such as hard disk drive 703 .
The subject matter described above is provided by way of illustration only and should not be construed as limiting. Various modifications and substitutions of the described components and operations can be made by those skilled in the art without departing from the spirit and scope of the present invention defined in the following claims, the scope of which is to be accorded the broadest interpretation so as to encompass such modifications and equivalent structures. For example, audio, text, spreadsheets, and databases could be encapsulated with meta data. Such audio may include information on heart murmurs. Text could include patient medical records and financial. Spreadsheets and databases may include company or hospital-wide activities.
As will be appreciated by those skilled in the art, the systems, methods, and procedures described herein can be embodied in a programmable computer, computer executable software, or digital circuitry. The software can be stored on computer readable media. For example, computer readable media can include a floppy disk, RAM, ROM, hard disk, removable media, flash memory, a “memory stick”, optical media, magneto-optical media, CD-ROM, etc.
As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a method, system or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit,” “component” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer readable medium(s) having computer readable program code embodied thereon.
Any combination of one or more computer readable medium(s) may be utilized.
The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of the computer readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
A computer readable signal medium may include a propagated data signal with computer readable program code embodied therein, for example, in base band or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, elector-magnetic, optical, or any suitable combination thereof. A computer readable signal medium may be any computer readable medium that is not a computer readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
Program code embodied on a computer readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wire line, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN), a wide area network (WAN), Ethernet, SCSI, iSCSI, Fibre Channel, Fibre Channel over Ethernet, and Infinitude, or the connection may be made to an external computer, for example, through the Internet using an Internet Service Provider.
Aspects of the present invention are described above with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
These computer program instructions may also be stored in a computer readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
The flowchart and block diagrams in the figures described above illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a component, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. | Embodiments of the invention relate to configuring a virtualization controller in SAN data storage system without disrupting I/O operations. One aspect of the invention concerns a method that comprises establishing a first data path between a host and a storage controller in the same communication zone wherein the storage controller comprises storage devices for storing data; adding a virtualization controller to the zone wherein the virtualization controller maps the storage devices to virtual volumes and establishes a second data path between the host and the storage devices through the virtual volumes; removing the first data path in response to the host detecting the second data path; and performing I/O operations between the host and the storage devices through the second data path. | 6 |
FIELD OF THE INVENTION
The present invention relates to a method for routing of data packets as well as a respective routing apparatus. In particular, the present invention relates to a method for routing of data packets according to the IPv6 protocol (“Internet Protocol Version 6”) and a respective routing apparatus.
BACKGROUND
As one of the essential components of an internet data transmission system, an IP router (“Internet Protocol”) makes a forwarding decision for an input data packet, i.e. it checks a destination address identifier carried in the packet header and directs it to the next output port or output link through which the data packet should be sent. For example, depending on the destination address identifier of the input data packet, the IP router can direct the data packet to a Next Hop router or an Egress™ port for transmission over a respective output link. In a computer network, the NHRP protocol (“Next Hop Resolution Protocol”) is a protocol which can be used so that a computer sending data to another computer can learn the most direct route to the receiving computer. An Egress™ port is a new type of port used in modern IP routers.
In the following, the routing of data is briefly explained with reference to FIG. 7 which shows the schematic construction of an IP router according to the prior art.
The IP router shown in FIG. 7 comprises an input block 1 which receives a plurality of input data packets over N input links or input ports IN 1 -INN. The input block 1 serves as an input queue and outputs the received data packets in a “First In First Out” (FIFO) manner. A header extracting block 2 is provided which extracts the packet header from the respective data packet to be transmitted so as to obtain the destination address identifier which is included in the packet header. In addition, the data packet is transferred to an output block 6 which serves as a switch. A routing table 4 stores all possible or available forwarding addresses and the respective output link/port numbers of the router. That is to say the routing table comprises a plurality of entries, each entry corresponding to a respective forwarding address to which a data packet can be forwarded by the IP router. The routing table 4 is generated and updated by a block 5 using routing protocols. In FIG. 7 , the routing updates are indicated with reference sign UPD. A routing unit 3 receives the destination address identifier extracted by the header extracting block 2 and uses this destination address identifier as a key for searching for a match in the routing table 4 , i.e. the routing unit 3 compares the destination address identifier with every entry corresponding to a respective forwarding address information stored in the routing table 4 . If the routing unit 3 finds a correspondence between the destination address identifier and one of the forwarding addresses stored in the routing table 4 , the respective output link/port number is transferred to the switch 6 , and the switch 6 switches the data packet to a respective one of a plurality of M output links/output ports OUT 1 -OUTM.
Hence, as long as the routing unit 3 finds a correspondence between the destination address identifier extracted by the header extracting block 2 and at least one of the entries stored in the routing table 4 , the respective data packet can be switched to one of the output links OUT 1 -OUTM. If, however, there is no match for the destination address identifier in the routing table 4 , the switch 6 cannot switch the respective data packet to one of the output links, and the data packet cannot be forwarded to its destination.
It is obvious that the cost associated with an IP router of the type shown in FIG. 7 and its performance depend very much on the size of the routing table 4 . The routing table 4 consumes silicon area and the look-up procedure consumes time as well as power, especially if the routing table 4 is large.
This problem in particular becomes more and more serious with the fast expansion of internet. The newly introduced IPv6 protocol provides address identifiers comprising 128 bits. Theoretically, for an n-bit destination address identifier, the routing table 4 may have up to 2 n entries. Hence, as regards the IPv6 protocol, there is a need for an enormous storing capacity for storing such a large routing table 4 . Such a large table size, however, makes the look-up procedure even impractical. Therefore, routing table look-up is regarded as the major bottleneck in today's routers.
The most straightforward method for routing table look-up is to perform a linear searching, i.e. compare the destination address identifier of the input data packet with each entry of the routing table until a correspondence between the address identifier and one of the entries in the routing table is recognized. Although this approach is simple, it is hardly used in actual practice due to its poor performance.
To speed up the look-up procedure, various strategies have been used. The most important ones are the usage of a so-called contents-addressed memory (CAM), the search according to a tree-based data structure, and the usage of so-called hashing strategies. Each of these known strategies has its own advantages and disadvantages. However, all of them are based on a search in the original data domain of the destination address identifier. Thus, all of these strategies require a relatively complex search procedure and a relatively large routing table size.
SUMMARY
Therefore, the object underlying the present invention is to provide a routing method for data packets as well as a respective routing apparatus which allow a smaller size of the routing table and, thus, enable a faster search for a correspondence between the respective destination address identifier and the entries stored in the routing table and decrease the costs associated with the routing table.
This object is achieved by a routing method and a routing apparatus according to embodiments of the present invention.
The basic idea of the present invention is that the routing table look-up can be performed in a compressed domain, i.e., before performing the look-up operation for an input data packet, its destination address identifier is first compressed to remove redundancy. Then, the look-up operation is carried out with the compressed destination address identifier as the key with respect to the routing table, the entries of which having been also compressed in the same manner as the destination address identifier of the input data packet.
Therefore, the look-up operation can be performed with respect to a smaller routing table and, thus, the costs and power consumption associated with the respective router can be reduced, while the performance of the router can be improved.
The compression of the destination address identifier as well as the forwarding address information entries of the routing table is performed according to one and the same data compression algorithm. In particular, a so-called lossless data compression algorithm is used which eliminates redundancy in the data without sacrificing any information content. There are several popular algorithms and variants of them which can be used for lossless compression. The most important examples are those of the Huffman, Arithmetic, and Lempel-Ziv (LZ) family.
Since the compression efficiency depends on the data characteristics of the destination address identifiers which the router deals with, parameters of the respective compressor, e.g. the code table, should be assigned or adjusted according to these characteristics.
As regards the data compression algorithm, a data compression algorithm can be used which utilizes a code table which assigns a symbol of the address information to be compressed a respective code word. Each code word has preferably a length which is inversely proportional to the appearance probability of the respective symbol in a given address table, for example an IPv6 address table. As a matter of course, the appearance probability of the symbols at the router input may also be considered to improve the overall performance.
By applying the above-mentioned data compression algorithm, the redundancy of the appearance distribution of some symbols or bit combinations in the destination address identifier is taken into account. Therefore, a kind of a spatial redundancy can be removed. However, there can still be other kinds of redundancy, e.g. redundancy in the time domain if there is a similarity of the destination address identifier for successive data packets. In order to remove such a redundancy in the time domain as well, there is preferably a feedback from the routing unit to the compressor unit used for compressing the destination address identifier so as to eliminate such a time domain redundancy and consider the similarity of a plurality of destination address identifiers within a data packet sequence.
Although the present invention can preferably be used for the routing of IPv6 data packets, the present invention is not limited to this preferred field of application and, as a matter of course, can be used for all kinds of data packets.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, preferred embodiments of the present invention will be explained in more detail with reference to the enclosed drawings.
FIG. 1 shows schematically an IP router according to a preferred embodiment of the present invention,
FIG. 2 shows an implementation example for an address compressor, a routing unit and a routing table shown in FIG. 1 , using a Huffman data compression algorithm,
FIG. 3 shows an example for a code table for the address compressor shown in FIG. 2 ,
FIG. 4 shows an example for a hexadecimal address to be processed by the address compressor according to the code table shown in FIG. 3 ,
FIG. 5 shows a table illustrating the test results of a test concerning the compression ratio of different IPv6 address tables,
FIG. 6 shows the dependence of the number of averaged bits and the number of entropy bits per byte in an IPv6 address, and
FIG. 7 shows schematically an IP router according to the prior art.
DETAILED DESCRIPTION
In practice, much redundancy may be involved in the destination address identifier to be processed by an IP router. To explore how much redundancy may be involved in an IP address, an experiment was carried out that tested, with various address tables, how many bits are really necessary to represent the information included in a quad, i.e. 4 bits, of an IPv6 address.
In FIG. 6 , the result of the test is shown in dependence upon the IPv6 address table size. A graph (i) shows the result of the test if a respective 4 bit-quad of an IPv6 address is compressed by using a Huffman encoder, i.e. graph (i) shows the number of averaged bits, which are obtained after the Huffman coding, depending on the address table size. In addition, a graph (ii) shows the number of entropy bits per quad depending on the address table size. That is to say graph (ii) shows the theoretical result, i.e. the number of bits which are really necessary to carry the information of the quad. From FIG. 6 it can be seen that, instead of 4 bits, the necessary bit number varies between 1.5 and 2. As the address table size exceeds 3×10 6 , the number of bits which are really necessary to carry the respective address information reaches a stable value of about 1.8. This means a compression potential of approximately (at least) 50%. It is to be noted that in this experiment only the redundancy of appearance distribution of some symbols (bit combinations) in an address identifier was taken into account. This corresponds to a kind of spatial redundancy. There can still be other kinds of redundancy, for example a redundancy in the time domain if there is a significant similarity of the address identifiers for some data packets which are to be processed one after the other.
It is not easy for a general look-up method to consider all kinds of redundancy completely. The approach described in the following in detail, however, makes it possible to combine the routing table look-up technique with a data compression technique. While the former technique is associated with a searching operation in a compact address table, the latter technique deals with all possible kinds of redundancy. By combining the advantages of both techniques, an optimum solution for the routing table look-up problem can be achieved.
FIG. 1 shows the structure of an IP router according to a preferred embodiment of the present invention. Those components which correspond to the components shown in FIG. 7 and having already been described before are indicated with the same reference signs as in FIG. 7 . In order to avoid repetitions reference can be made to the description with respect to FIG. 7 .
The IP router of FIG. 1 differs from that shown in FIG. 7 in that the IP router works in a compressed address domain. A first address compressor 7 is arranged in the path between the header extracting block 2 and the routing unit 3 . This address compressor 7 translates the destination address identifier provided by the header extracting block 2 , which comprises 128 bits for an IPv6 destination address identifier, for example, into an in average shorter form using a data compression algorithm. The compressed destination address identifier is then forwarded to the routing unit 3 and used as the key for the look-up operation with respect to the routing table 4 . In addition, an identical address compressor 8 is arranged in the path between the block 5 generating and updating the routing table 4 and the routing table 4 . Hence, the address compressor 8 stores the forwarding address information in a compressed form in the routing table 4 using the same data compression algorithm as the address compressor 7 . Thus, the routing table 4 is provided in a very compact form and, in particular, the routing table 4 is consistent with the compressed destination address identifier output by the address compressor 7 and used as the key for the look-up operation by the routing unit 3 . The routing unit 3 may use conventional methods for searching for a correspondence between the compressed destination address identifier and one of the compressed forwarding addresses stored in the routing table 4 .
The data compression algorithm used by the address compressors 7 , 8 is particularly a so-called lossless data compression algorithm. Such a lossless data compression algorithm eliminates redundancy in the respective data without sacrificing any information content. There are several popular algorithms and variants of them which could be used for such a lossless data compression. The most important examples are the data compression algorithms of the Huffman, Arithmetic, and Lempel-Ziv (LZ) family.
Since the compression efficiency depends on the data characteristics of the destination address identifiers that the router deals with, at least some of the parameters of the address compressors 7 , 8 , e.g. the code table used by the address compressor, should be assigned or adjusted according to or in dependence upon these data characteristics. Therefore, the IP router shown in FIG. 1 comprises a compressor parameter block 9 which collects this information on the data characteristics of the respective destination address identifier from the header extracting block 2 and calculates the compression parameters for the data compression algorithm used by the address compressors 7 and 8 .
As already described above, the address compression effected by the address compressors 7 , 8 takes into account the redundancy of the appearance distribution of some symbols (bit combinations) in the respective destination address identifier. However, there can be another kind of redundancy in terms of the similarity of the destination address identifiers of a plurality of successive data packets. In order to eliminate such a redundancy in the time domain as well, the IP router according to FIG. 1 comprises a feedback connection from the routing unit 3 to the address compressor 7 used for compressing the destination address identifiers. Such a feedback from the routing unit 3 to the address compressor 7 allows to take into account the similarity of the destination address identifiers within a data packet sequence. This can be done, for example, by determining the forwarding address for the switch 6 on the basis of a forwarding address having been determined before in case the new destination address identifier, for which the forwarding address is to be determined by the routing unit 3 , is very similar to the respective preceding destination address identifier.
FIG. 2 shows an implementation example for the address compressor 7 , the routing unit 3 , and the routing table 4 shown in FIG. 1 . In particular, this implementation example corresponds to an architecture for processing IPv6 data packets. Although FIG. 2 shows a hardware diagram of the respective components, as a matter of course, the proposed architecture can be implemented with different hardware in software or in a combination of hardware and software as well.
The address compressor 7 shown in FIG. 2 receives an extracted destination address identifier ADR from the header extracting block 2 shown in FIG. 1 . In the case of an IPv6 data packet, this destination address identifier ADR comprises 128 bits which are divided into 32 4 bit-quads by a block 10 . Each quad is then translated into a code word comprising several bits using for example a code table shown in FIG. 3 . This is done by a coding block 13 .
The code table shown in FIG. 3 comprises a first column (A) listing all possible hexadecimal values of a quad comprising 4 bits. In a second column (B), the respective binary code assigned to each quad value is depicted. In addition, in a column (C) the code length for each code word is depicted.
The 32 code words output by the coding block 13 are then combined by an address composing block 14 so as to obtain the compressed destination address which is then buffered in a first buffer 20 of the routing unit 3 . In addition, there is a block 11 storing the respective code word length table corresponding to column (C) of FIG. 3 , and a block 12 sums up the code word lengths output by the block 11 for the respective address identifier ADR. The result is then buffered in a second buffer 15 . Hence, the buffer 15 stores the sum of the length of the code words for the respective destination address identifier ADR, i.e. the length of the compressed address identifier, while the buffer 20 stores the combination of the code words assigned to the respective destination address identifier ADR, i.e. the compressed destination address identifier. The result stored in the buffer 15 is calculated by the block 12 on the basis of column (C) shown in FIG. 3 , while the result stored in the buffer 20 is determined by the block 14 on the basis of column (B) shown in FIG. 3 .
FIG. 4 shows an example for a destination address identifier ADR to be compressed in accordance with the code table shown in FIG. 3 . According to the code table of FIG. 3 , this address is compressed to 56 bits. Each “F” value results in 1 bit of the compressed address, each “E” value results in 1 bit of the compressed address, each “D” value results in 3 bits of the compressed address, the “B” value results in 5 bits of the compressed address, the “7” value also results in 5 bits of the compressed address, the “4” value results in 6 bits of the compressed address, and the “3” value also results in 6 bits of the compressed address. Hence, the compressed address determined according to the code table shown in FIG. 3 comprises 22×1=22 bits for all “F” values, 1×6=6 bits for the “4” value, 1×5=5 bits for the “B” value, 1×6=6 bits for the “3” value, 1×5=5 bits for the “7” value, 3×1 =3 bits for all “E” values and 3×3=9 bits for all “D” values of the input destination address. Thus, the compressed address comprises 56 bits in total.
The code table shown in FIG. 3 is generated by the compressor parameter block 9 shown in FIG. 1 which outputs the compressor parameters CPAR used by the blocks 11 , 13 of the address compressor 7 shown in FIG. 2 . In particular, the code table of FIG. 3 corresponds to a code having been implemented by a Huffman encoder. In the present case, the Huffman encoder assigns to each symbol (quad) a code word that has a length which is inversely proportional to the appearance probability of the respective symbol in an IPv6 address table comprising 872640 entries (13962240 bytes). The implementation of such a Huffman encoder, either in software or in hardware, can be found in many documents and publications dealing with data compression. Therefore, a detailed description of such a Huffman encoder or of the construction of the compressor parameter block 9 , which is implemented with a Huffman encoder, is not considered necessary.
The routing table 4 shown in FIG. 2 is composed of possible forwarding addresses that are compressed with the same compression parameters CPAR, i.e. the same code tables as those used by the address compressor 7 . These compressed forwarding addresses are arranged in sub-tables according to their length. The compressed address length b 0 -b N , the number of entries n 0 -n N , and the base address a 0 -a N of each sub-table are stored in a leading table 27 . The routing unit 3 works to find a match for the compressed input destination address in the compressed routing table 4 . This is effected as follows:
A block 17 reads an entry of the leading table 27 and sends the address length bi thereof to a length comparator 16 . The length comparator 16 compares the length of the compressed input address as stored in the buffer 15 with each entry read out by the block 17 . The length comparator 16 compares the length of the compressed input address with each address length b i stored in the leading table 27 so as to find the corresponding sub-table. If a match is found by the length comparator 16 , a block 18 is reset, and thereafter the block 18 sends the base address a i of the found sub-table to a block 24 and initializes a counter 23 to the number of entries n i of the respective sub-table for the following address look-up operation.
Then, the routing unit 3 compares the compressed input address itself, as stored in the buffer 20 , with the compressed address c j,i stored in the sub-table as determined by the above-described search operation. A block 24 reads an entry from the respective sub-table 28 and sends the address c j,i to an address comparator 21 . This address comparator 21 compares the compressed input address stored in the buffer 20 with the compressed forwarding address provided by the block 24 . With each comparison operation effected by the address comparator 21 , an AND gate 22 decrements the counter 23 . Therefore, the comparison operation of the address comparator 21 is repeated until a correspondence is found between the compressed destination address and one of the compressed forwarding addresses stored in the sub-table 28 , or until the counter 23 is decremented to zero. An 1 bit-latch 25 holds the latest comparison results of the address comparator 21 . If there is a correspondence between the compressed input destination address and one of the compressed forwarding addresses stored in the sub-table 28 , the 1 bit-latch 25 generates a signal for a logic gate 26 , which effects a logic AND operation between the output signal of the 1 bit-latch 25 and an inverted output signal of the counter 23 . This output signal of the counter 23 has a low level as long as the counter 23 has not reached the value zero. Hence, the output signal VALID of the logic gate 26 indicates whether the output port number or output link number o j,i currently processed by the block 24 is valid and can be used for the forwarding operation of the switch 6 (see FIG. 1 ). It should be noted that the index “i” indicates the number of the respective sub-table, while the index “j” indicates the number of the respective entry within a sub-table.
A further block 19 of the routing unit 3 effects a byte alignment operation of the coded or compressed input address, which is stored in the buffer 20 , by zero padding of the remaining bits.
According to the implementation example shown in FIG. 2 , each destination address identifier ADR is divided up into 4 bit-symbols. However, as a matter of course, the destination address identifier may also be divided up in a different manner. In addition, the code table shown in FIG. 3 is determined only by considering the appearance probability of the respective symbols (quads) in a given address table, in the present case in an IPv6 address table. However, the appearance probability of the symbols at the router input can also be considered in order to improve the performance of the IP router. Finally, as already indicated above, the present invention is by no means limited to Huffman codes. Any lossless data compression algorithm can be used as a basis for the implementation of the address compressors 7 , 8 , the routing unit 3 and the routing table 4 .
The model of using compressed destination address identifiers and compressed forwarding addresses was tested using a plurality of IPv6 address tables of various sizes. FIG. 5 illustrates the test result. Column (A) indicates the number of the respective IPv6 address table, column (B) contains the number of entries of the respective IPv6 address table, column (C) contains the original sizes (bytes) of the IPv6 address table, column (D) contains the compressed sizes (bytes) of the IPv6 address table, and column (E) indicates the compression ratio (%) which could be achieved. As can be seen, the required size of the routing table can be reduced dramatically. This leads to an improved performance of the IP router and helps to save memory and power for the look-up operation. The test result coincides with the theoretical analysis of FIG. 6 . | In order to be able to use a smaller routing table ( 4 ) and, thus, to reduce the costs and power consumption and to improve the performance of an IP router, it is proposed to extract a destination address identifier (ADR) from a data packet to be forwarded by the IP router, compress the extracted destination address identifier (ADR) by using a lossless data compression algorithm, and compare the compressed destination address identifier with entries stored in the routing table ( 4 ) so as to find a correspondence between the destination address identifier and one of the entries of the routing table ( 4 ). Each entry of the routing table ( 4 ) corresponds to a possible or available forwarding address of the IP router, the forwarding addresses having been compressed with the same data compression algorithm as the destination address identifier. After having found a correspondence between the destination address identifier and one of the compressed forwarding addresses stored in the routing table ( 4 ), a switch ( 6 ) of the IP router switches the respective data packet to one of its output links (OUT) which is associated with the respective forwarding address matching the destination address identifier (ADR). | 7 |
BACKGROUND OF THE INVENTION
This invention relates generally to a print wheel printer and more particularly to a printer wherein printing is performed by selection of corresponding symbols or characters on rotated print wheels by utilizing a plurality of independent and operatively selective pawls.
A print wheel printer generally comprises a plurality of print wheels which are secured to corresponding ratchet wheels, a plurality of selective pawls which stop the rotation of print wheels at selective rotational positions by engaging corresponding notches of the ratchet wheels, a plurality of electromagnetic mechanisms which rotate selected pawls to bring them into selective engagement positions with corresponding ratchet wheels, a reset lever for collectively returning all of the pawls from a print wheel engaging position to a print wheel disengaging position and a reset cam changing the positional relationship of the reset lever relative to the pawls.
As it is disclosed in Japan Laid Open Patent 144521/75, the positioning members for spatially positioning the print wheels along the print wheel shaft and the separate construction of the selective pawls on the main housing frame of the printer result in many different steps necessary for assembling together these many printer parts. Further, since positioning of these parts are determined indirectly relative to the main housing frame of the printer due to their support relative to the housing, as well as relative positional aberrations due to the lack of precision of the manufactured printer parts and the required assembly of many different parts involved, render it always necessary to perform fine adjustments after the assembly of the printer parts.
Also, since the reset lever in these printers is fixed on a trigger unit casing via a support shaft, it is necessary to disengage the trigger unit from the main housing frame each time when the reset lever is to be removed and replaced onto to trigger unit casing.
It is an object of the present invention to provide a print wheel printer wherein assembly of a plurality of parts which perform functions in connection with the operation of the print wheels is performed easily and with high precision.
It is another object of this invention to provide a simpler and more precise positioning of the print wheels of a print wheel printer.
It is still another objective of this invention to render it possible to remove and reposition a reset lever while the trigger unit casing remains secured to the main housing frame of the print wheel printer.
SUMMARY OF THE INVENTION
According to this invention, a print wheel printer includes a trigger unit casing and a main housing frame, a plurality of print wheels rotatably mounted on a print wheel shaft and having a corresponding ratchet wheel secured to one side of each print wheel. A plurality of rotatably mounted selective pawls are supported on the trigger unit casing for stopping the rotation of the print wheels at selected print wheel engagement positions wherein a corresponding pawl is rotated into position to engage a corresponding print wheel ratchet wheel. A rotatable reset lever is also mounted on the trigger unit casing for the purpose of returning the selective pawls to a print wheel disengagement position. The selective pawls and the reset lever are both supported on the trigger unit casing in a prealigned relationship and support means are provided on the main housing frame for supporting the set of print wheels. Interengagement means on the trigger unit casing and the main housing frame provide for securing the casing onto the main housing frame whereby positional alignment of the casing selective pawls relative to the print wheel ratchet wheels is achieved without need for any further after-assembly adjustment.
Supporting members for supporting the selective pawls and reset lever are constructed and assembled as a single unitary unit in the printer unit casing and the unit casing is positioned on the printer main frame via preformed alignment means. Also, the positioning member of print wheels, which determine the print wheel position along the print wheel support shaft is constructed as a unitary unit in the printer unit casing. Further, beam shaped members are provided on opposite ends of the reset lever and have engaging portions at the lower end of the beams that are releasably secured with engaging portions provided on the printer trigger unit casing to attach the reset lever to the casing in a manner that it will not disengage from the latter when once assembled.
Other objects and attainments together with a fuller understanding of the invention will become apparent and appreciated by referring to the following description and claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded illustration of the key components of a disassembled print wheel printer comprising this invention.
FIG. 2 is a perspective illustration of the key components of FIG. 1 in assembled form.
FIG. 3 is a side view of the trigger unit casing and the main housing frame.
FIG. 4 is side elevation of the operating structure of the print wheel printer.
FIG. 5 is a front elevation of the print wheel printer.
FIG. 6 is an enlarged perspective view of a key component of the reset lever of the print wheel printer.
FIGS. 7 and 8 are perspective illustrations of means by which a reset lever is installed in the print wheel printer.
FIGS. 9 through 12 are a series of side elevations of the print wheel printer illustrating the printing action of the printer.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is now made to FIGS. 1 and 2 wherein there is illustrated disassembled and assemble key components of a print wheel printer comprising this invention. These printer components comprise trigger unit casing 1, main housing frame 2, selective pawls 6, pawl shaft 7, reset lever 8, reset cam shaft 9 and reset cam 10 on shaft 9. As illustrated relative to FIGS. 1, 2 and 3, trigger unit casing 1 is positioned on main housing frame 2 via horizontal positioning slots 2A which also are guides for positioning and precision alignment of casing 1 relative to housing 2. As shown in FIG. 4, print wheels 11 are supported on print wheel shaft 13. Print wheel shaft 13 is supported in upwardly open shaft slots 2B on main housing frame 2. The positioning of trigger casing 1 relative to the supported positions of print wheels 11 is accurately determined by print wheel shaft 13 as fixed in aligned apertures 2B as best illustrated in FIG. 4.
As shown in FIGS. 1 and 3, trigger unit casing 1 has outwardly projected guides 1C on the upper portion of both sides of the frame of casing 1 and guides 1C extend on either side of elongated aperture 1F, i.e., projected guides 1C are of extended length in the direction of installation of trigger unit casing 1 into frame 2 with aperture 1F intervening between extended portions of guides 1C. Projected guides 1C slide into horizontal positioning slots 2A, as illustrated in FIG. 3. Projected guides 1C accurately determine transverse positioning of trigger casing 1 within the inner end of horizontal positioning slots 2A of frame 2 and determine vertical positioning of casing 1 within frame 2 relative to the height of horizontal positioning slots 2A on frame 2. As shown in FIG. 3, there are two or more projections 1D on the upper surfaces of guides 1C to insure a secure and tight fit of casing 1 on housing 2.
FIGS. 4 and 5 illustrate the key operating components of the print wheel printer of this invention. Trigger unit casing 1 comprises trigger coil 4, permanent magnet 5 and a plurality of print wheel position determining members 3 which protrude along adjacent sides of print wheels 11. At both sides of the upper portion of casing 1 are elongated apertures 1F for supporting selective pawl shaft 7. Selective pawls 6 are rotatably mounted on selective pawl shaft 7. Selective pawl shaft 7 is supported in elongated apertures 1F in a manner wherein selective pawl shaft 7 is biased toward print wheel 11 by means of coil spring 7A. Apertures 1G in FIG. 1 support reset lever shaft 8D and upwardly open apertures 1H support reset cam shaft 9. At the end of trigger unit casing 1 corresponding to the closest proximity to print wheels 11 after assemblage, there are a plurality of print wheel positioning members 3 extending at spaced intervals between adjacent print wheels 11 and determine the positional relationship of print wheels 11 along shaft 13 upon assembling of casing 1 to frame 2.
As it can be seen in FIG. 1, there are a plurality of aligned rectangular apertures 1E formed in the upper surface of trigger unit casing 1 into which are inserted and supported two lower legs 6A and 6B of each selective pawl 6. This inserted positioning is best seen in FIG. 4. A trigger coil 4 is positioned in a lower portion of each rectangular aperture 1E. Below each trigger coil 4 are positioned a magnetic coil 5 aligned perpendicular relative to pawl shaft 7. Two pole plates 5N and 5S are secured on opposite magnetic poles of each permanent magnet 5 and function to magnetically draw selective pawl leg 6A and rotate the bottom end portion of selective pawl leg 6A. In this connection, leg 6A extends through hollow core portion 4A of trigger coil 4. One of the two upper legs 6C and 6D of each selective pawl 6, i.e., leg or extension 6C, becomes engaged with one of the grooves or notches 12A of ratchet wheel 12. Ratchet wheel 12 is secured to one side of each print wheel 11. The engagement of pawl extension 6C engages a notch 12A which positions one of characters 11A on the periphery of print wheel 11 to be aligned in proper printing position. When pawl notch 6C becomes engaged with notch 12A of ratchet wheel 12, the positive going edge leg 6D which becomes engaged with hitching pawl 8A of reset lever 8.
Reset lever 8 is operated by reset cam 10 so that selective pawls 6 rotate between two different positions, a print wheel engaging position and a print wheel disengaging position. Hitching pawl 8A at the upper end of lever 8 is an elongated member widthwise relative to the printer so that all selective pawls 6 can be returned concurrently to the print wheel disengaging position. Projection 8B on reset lever 8 is engaged by respective cam portions 10C and 10A of reset cam 10 when cam 10 is rotated on shaft 9.
As best illustrated in FIG. 6, along adjacent sides of reset lever 8 next to inner main housing frame 2 are beam shaped members 8C which are integral to one end of lever 8. At the lower end of each member 8C is outwardly extended shaft 8D. Shafts 8D are inserted into reset lever shaft support apertures 1G positioned at the upper portion of trigger unit casing 1, as shown in FIG. 1. Wedge member 8E is then inserted between beam shaped member 8C and the body of lever 8 in order to prevent the disengagement of lever 8 from apertures 1G after its installation on casing 1.
FIGS. 7 and 8 illustrate two other embodiments for installation of reset lever 8 relative to casing 1. As shown in FIG. 7, flexible member 22 is supported relative on trigger unit casing 1. Upper extended flexible portions 21 of member 22 are easily flexed, as indicated by the arrows in FIG. 7, and projections 21A formed near the top ends of flexible members 21 are engaged with corresponding recesses 28A formed in adjacent lower side portions of reset lever 28.
In the case of FIG. 8, shaft portions 28B of reset lever 28 become securely engaged within W shaped reset lever shaft support slots 22G of trigger unit casing 22. The upper ends of slot extensions 22H are flexible and separate to permit the retention of shaft portions 28B.
As previously indicated, reset lever 8 is driven by the rotation of reset cam 10 via shift 9. As shown in FIG. 1H, reset cam shaft 9 is supported in upwardly open slots 1 at the top of trigger unit casing 1, i.e., at the vertex of a triangle formed by apertures 1F, 1G and 1H wherein apertures 1F and apertures 1G are at the base of the triangle.
Assembly of the key components of the print wheel printer is as follows. First, a plurality of selective pawls 6 corresponding to the number of print wheels 11 are inserted into rectangular apertures 1E located at the top of trigger unit casing 1. Next, selective pawls 6 are installed by inserting selective pawl shaft 7 through holes 6E in each of the pawls 6 by first inserting shaft 7 from one side of trigger unit casing 1 into casing elongated aperture 1F and thence through center holes 6E of each selective pawl 6 and thereafter through the other casing elongated aperture 1F at the other side of trigger unit casing 1.
Next, reset cam shaft 9 is positioned in upwardly open slots 1H at the top of trigger unit casing 1. Further, projected shaft portions 8D, located at the lower ends of each side of reset lever beam member 8C are set into shaft apertures 1G from within trigger unit casing 1. During the course of this insertion, beam shaped members 8C are bent slightly inward to accommodate the placement of shaft portions 8D into apertures 1G. Print wheel positioning members 3 and all the moving members for selecting characters are then assembled relative to trigger unit casing 1 as a single unitary unit.
Next, assembled trigger unit casing 1 is positioned and fixed accurately both in transverse and vertical directions by inserting horizontal projection guides 1C located on adjacent sides of trigger unit casing 1 into horizontal positioning slots 2A of main housing frame 2 and casing 1 is pushed into housing frame 2 until the forward end of projected guides 1C reach the end of slots 2A. Thus, a plurality of print wheel positioning members 3 located at the edge of trigger unit casing 1 are accurately positioned between respective print wheels 11 thereby determinative of the aligned location of each rotatably mounted print wheel 11 in the printer as well as their uniform spatial relation along print wheel shaft 13.
The functional operation of the print wheel printer is as follows. First, as shown in FIG. 9, when reset cam 10 rotates in the direction indicated by arrow A, reset lever 8 rotates in the direction indicated by arrow B due to engagement of projection 10A with lever projection 8B. As a result, all selective pawls 6 together with selective pawl shaft 7 are move in a direction indicated by arrow C due to the pulling action of hitching pawl 8A on pawl legs 6D. Thus, pawl extensions 6C are all disengaged from projections 12B of ratchet 12 thereby permitting free rotational movement of respective print wheels 11 on shaft 13.
As reset cam 10 continues in its path of rotation in the direction of arrow A, reset lever projection 8B drops to a small diameter cam portion 10B of cam 10 and, as a result, lever 8 moves in the direction indicated by arrow D, as shown in FIG. 10, due to the force reset lever spring 8F. As a result, all selective pawls 6 are freed from hitching pawl 8A of lever 8 and are now set free to rotate about shaft 7.
In this condition, when a voltage is applied to a selected trigger coil 4 of a corresponding selective pawl 6, leg 6A of the selected pawl 6 is magnetically repelled by magnetic pole plate 5S and drawn to magnetic pole plate 5N, as illustrated in FIG. 11. As a result, the selected pawl 6 is rotated in the direction of arrow G about shaft 7. At this time, pawl extension 6C of the selected pawl will become engaged with a corresponding notch 12A of rotating ratchet wheel 12 thereby stopping the rotational motion of corresponding print wheel 11 secured to the stopped ratchet wheel 12. Also, at the same time, print wheel spring 14 comes out of the groove of print wheel shaft 13 allowing print wheel shaft 13 to continue to rotate while the selected print wheel 11 is stopped at its selected position. Thus, a selected character 11A on the periphery of print wheel 11 is placed in a selected printing position. Printing roller 17 is supported by printing roller support 16 secured on printing shaft 15 and upon rotation brings about pressure engagement of recording medium S from the back surface thereof and printing is performed on the front surface of medium S, as illustrated in FIG. 12. When this printing action is completed, reset cam 10 has rotated one complete cycle and reset lever 8, due to engagement cam portion 10C by lever projection 8D, is rotated in a counterclockwise direction, i.e., in the direction indicated by arrow B in FIG. 10. As a result, all selective pawls 6 are again rotated and laterally moved on shaft 7 by lever hitching pawl 8A in the direction indicated by arrow C in FIG. 9. Thus, all pawl extensions 6C engaged with ratchet wheel notches 12A become disengaged from these notches 12A and pawl extensions 6C become engaged with projections 12B of ratchet wheels 12 to reset each of print wheels 11.
While the invention has been described in conjunction with several specific embodiments, it is evident to those skilled in the art that many further alternatives, modifications and variations will be apparent in light of the forgoing description. Thus, the invention described herein is intended to embrace at such alternatives, modifications, applications and variations as fall within the spirit and scope of the appended claims. | A print wheel printer includes a trigger unit casing and a main housing frame, a plurality of print wheels rotatably mounted on a print wheel shaft and having a corresponding ratchet wheel secured to one side of each print wheel. A plurality of rotatably mounted selective pawls are supported on the trigger unit casing for stopping the rotation of the print wheels at selected print wheel engagement positions wherein a corresponding pawl is rotated into position to engage a corresponding print wheel ratchet wheel. A rotatable reset lever is also mounted on the trigger unit casing for the purpose of returning the selective pawls to a print wheel disengagement position. The selective pawls and the reset lever are both supported on the trigger unit casing in a prealigned relationship and support means are provided on the main housing frame for supporting the set of print wheels. Interengagement means on the trigger unit casing and the main housing frame provide for securing the casing onto the main housing frame whereby positional alignment of the casing selective pawls relative to the print wheel ratchet wheels is achieved without need for any further after-assembly adjustment. | 1 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to cleaning equipment for a swimming pool and more particularly to a portable buoyant skimming apparatus designed to remove surface debris by directing the debris towards the inlet of the pool's filtration system.
2. Summary of Related Art
Removal of dirt and debris from swimming pools is a constant problem. The majority of the contaminants enter the pool through the surface where they float for a relatively short period before they sink to the bottom of the pool. Consequently, pools require regular cleaning to remove contaminants from the bottom of the pool.
Conventional swimming pools attempt to remove surface debris through filtration systems. A filtration device circulates pool water via a pumping system through a filtration inlet, located at the surface level, through a filter and back into the pool. The discharge of the pump into the pool is oriented to create a current or flow around the perimeter of the pool towards the filtration inlet. The flow pushes surface debris towards the filtration inlet where the debris is entrained and removed.
The filtration systems are not always effective in removing all of the surface debris from the pool. The problem stems from the fact that the inlet is usually perpendicular to the current flow and is narrow and does not cover a large surface area. Therefore, most surface debris does not enter the inlet of the filtration system and remains in the pool. The debris, if not removed by manually skimming, eventually sinks to the bottom of the pool. The pool will then require additional cleaning which is often very labor intensive.
Diverter devices for improving the skimming function in swimming pools are known. The diverter devices, placed near the filtration inlet of the pool, generally employ a mechanical arm extending horizontally into the flow of the circulating pool water. The current carries the floating debris into the mechanical arm of the device. The angle of the apparatus in combination with the current forces the floating debris along the mechanical arm and into the filtration inlet where it is then entrained and subsequently removed.
Most of the devices are fastened onto the side wall of the pool or onto the filtration inlet by a fixed mechanical means. The mechanical fastening devices require additional structural changes to the side wall of the pool or the filter inlet. They also create a potential hazard with additional hardware extending into the swimming area.
The diverter devices generally use a mechanical arm with a front edge having a vertical surface for directing the floating debris. The vertical surface is positioned at the surface of the water and is partially immersed to guide the debris in the filtration inlet. Most of the devices utilize a vertical surface in the form a metal bar while others attach a vertical surface onto an additional element. The majority of these devices require extensive fabrication and are not light weight and portable.
U.S. Pat. No. 3,152,076 issued to Kreutzer discloses a filter system which circulates the water in the pool. A straight wand device is secured to the side of the pool and floats on the surface of the water to direct debris into the inlet of the filter system. A special mounting bracket and shank are used to secure the wand to the side of the pool.
U.S. Pat. No. 3,774,767 issued to Field shows a buoyant member having laterally angled inner and outer ends. A cord and a small weight are used to secure the device to the side of the pool. The buoyant member is formed by a cylindrical tube having a vertical planar strip affixed to the side to direct the debris into the inlet.
U.S. Pat. No. 4,455,695 issued to Mikhel discloses an alternative configuration for a skimming device. The guide bar has a rectangular cross section. The bar is maintained in the desired position by a pair of tie bars secured between the guide bar and the side of the pool.
U.S. Pat. No. 4,720,340 issued to O'Brien discloses a skimming device with a floating blade and a support rod. One end of the blade is positioned in the corner of the inlet and the other is supported in the water by the rod. The rod is provided with a weighted mounting means to secure the rod to the pool.
The prior art inventions generally disclose a skimming apparatus for directing debris into the filtration inlet. However, most of the devices utilize a fixed means at the filtration inlet to secure a mechanical arm. Most of the devices use a vertical edge to direct the debris into the filtration inlet. These devices generally require some detailed fabrication of the apparatus or fabrication at the side of the pool in order to provide the vertical edge or a fixed mechanical securing means.
It would be advantageous to have a portable buoyant skimming apparatus which is easily set up and removed and which improves the skimming capability of a pool's filtration system. Furthermore, it would be a benefit to have a device that is easily fabricated from low cost standard materials of construction and installed without requiring any modifications to the pool.
SUMMARY OF THE INVENTION
In accordance with the present invention, there is provided a portable buoyant skimming apparatus for removing surface debris from a swimming pool. The apparatus includes two elongate members constructed of a light weight buoyant material. A first elongate member is provided with an inlet end, a junction end, and a debris edge. The debris edge extends longitudinally along the first member and directs floating debris toward the inlet end.
A second elongate member is attached to the junction end of the first elongate buoyant member at an obtuse angle. The inlet end of the first elongate buoyant member is temporarily secured at the pool wall near the inlet of the filtration system.
An elongate support member pivotly connects to the junction of the first and second members. The elongate support member is equal to or greater in length than the first member such that the free end of the support member may be used to position and support the apparatus from the side of the pool. The support member may be moved to an open position at an acute angle to the first member or to a closed position parallel with the first member. When the elongate support member is in an open position, the apparatus may be placed in the pool and the free end of the support member can engage the top edge of the pool. This temporarily secures the apparatus in place in the pool.
The apparatus directs floating debris circulated by the pool's filtration system along the debris edge of the first member and into the filtration inlet. When the skimming is completed, the apparatus may be removed and the support bar moved to the closed position for storage.
The objective of the present invention is to provide a portable low cost skimming apparatus which improves the skimming capability of a pool's filtration system. The apparatus is light weight and portable such that an individual can easily install and remove the skimming apparatus from the pool.
A further objective is to eliminate the need for attaching the present invention to the side of the pool by a fixed mechanical means. The tubular design of the present invention reduces the force exerted by the water against the present invention. The reduced force eliminates the need for attaching the invention by a fixed mechanical means.
Another objective is to produce the apparatus from low cost standard materials in a manner which does not require extensive fabrication.
BRIEF DESCRIPTION OF THE DRAWINGS
The above, as well as other advantages of the present invention, will become readily apparent to those skilled in the art from the following detailed description of a preferred embodiment when considered in the light of the accompanying drawings in which:
FIG. 1 is a perspective view of the skimming apparatus as it is positioned for use in a pool.
FIG. 2 is a top elevation view of the skimming apparatus in use with arrows indicating the path the floating debris will follow.
FIG. 3 is a cross sectional view along line 1--1 of the first elongate member indicating the debris edge.
FIG. 4 is a cross sectional view of the first elongate buoyant member having an enhanced debris edge formed by a plastic sheet.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawings, there is illustrated in FIGS. 1 and 2 a swimming pool 10 filled with water. The swimming pool 10 has a side wall 12 with a filtration inlet 14 in the side wall 12 positioned at the water level of the pool 10. The skimming apparatus 18 is positioned in the pool 10 near the filtration inlet 14 in order to sweep floating debris into the filtration inlet 14.
The skimming apparatus 18 is made up of a first elongate buoyant member 20, a second elongate buoyant member 28, and an elongate support member 32. The first elongate buoyant member has an inlet end 22, a junction end 24, and a debris edge 26. The inlet end 22 contacts the side wall of the pool 12. The first elongate buoyant member 20 extends into the current at an acute angle from the side wall of the pool 12. The debris edge 26 is created on the current side along the longitudinal surface of the first elongate member 20.
The second elongate buoyant member 28 has a junction end 30 which is coupled to the junction end 24 of the first elongate member 20 at an obtuse angle. The two elongate buoyant members 20 and 28 are connected in the same plane by an angled elbow connector 37. The preferred angle is about 120 degrees. This angle allows for the proper extension of the second elongate buoyant member 28. The angle also provides a steep enough acute angle on the first elongate buoyant member 20 to allow the debris which collects upon the debris edge 26 to flow towards and into the filtration inlet 14.
The elongate support member 32 includes a pivot end 34 connected at the junction of the first elongate buoyant member 20 and the second elongate buoyant member 28 by a pivotable connector 38. The pivotable connector 38 allows the elongate support member 32 to move freely to an open position where the elongate support member 32 is at an acute angle to the first elongate buoyant member 20, or a closed position where the elongate support member 32 is parallel with the first elongate buoyant member 20.
The preferred materials of construction are poly-vinyl chloride pipe having a diameter range of 2-4 inches. The poly-vinyl chloride pipe is light weight and inexpensive. The diameter range of the pipe must be large enough to create a buoyant member extending high enough above the water line to create a sufficient debris edge 26. poly-vinyl chloride end caps enclose the first and second elongate members 20, 28 and seal their respective ends. The elongate support member 32 is also constructed with poly-vinyl chloride pipe. The diameter of the elongate support member 32 does not need to be the same size as the first and second elongate buoyant members 20,28. Other light weight materials of construction which can create a buoyant round member are suitable as well.
The debris edge 26 can be optionally enhanced by wrapping the perimeter of the first elongate buoyant member 20 in a plastic sheet 44 as illustrated in FIG. 4. An excess portion of the sheet extends from the first elongate buoyant member 20 to form a lip 46. The lip 46 extends into the water at an acute angle to create an extension of the debris edge 26 below the water surface.
The junction ends 24 and 30 of the elongate members 20 and 28 are joined by a standard poly-vinyl chloride elbow connector 37. Other connectors will function as well as long as the preferred obtuse angle is obtained. This includes angled ends for the elongate members 20 and 28 where the junction ends 24 and 30 are integrally connected.
There are several variables which effect the size and length of the elongate buoyant members 20 and 28. The length of the elements depend upon the size of the pipe, the size of the pool, the shape of the pool, and the strength of the current from the filtration system. The elements must extend outward into the pool in order to provide a sufficient sweep to collect floating debris. The elements must also withstand the force of the current generated from the filtration system.
The skimming apparatus 18 is temporarily held in place by securing the inlet end 22 of the skimming apparatus 18 to the side wall 12. FIG. 1 shows a weighted object 40 positioned on top of the side wall 12. A fastening rope 42 is connected to the inlet end 22 of the first elongate buoyant member 20 and to the weighted object 40.
The weighted object 40 can be a hollow container filled with weighted material. Any flowable material, such as water, sand, or stone, is suitable to provide weight for the container. Pool water is preferred as it can be poured back into the pool after use and thereby reduce the overall weight of the entire apparatus thus making it easier to store away.
Having set forth a description of the structure of the present invention, its use and function may now be described with particular reference to FIG. 2. The skimming apparatus 18 is placed in the pool 10 near the filtration inlet 14. The skimming apparatus 18 extends outward across the water surface of the pool 10. The inlet end 22 of the first elongate member 20 abuts the side wall 12 near the filtration inlet 14.
The first elongate buoyant member 20 extends outward at an acute angle from the side wall 12 into the current generated by the filtration system. The second elongate buoyant member 28 is therefore positioned longitudinally with the oncoming current. The second elongate buoyant member 28 provides buoyancy for the junction end 24 of the first elongate buoyant member 20 an assists in directing floating debris into the debris edge 26 of the first elongate buoyant member 20.
The elongate support member 32 is placed in an open position at an acute angle to the first elongate buoyant member 20. The acute angle is about 60 degrees. The free end 36 of the elongate support member 32 temporarily engages the top of the side wall 12 and secures the skimming apparatus 18 in place. In general, a weighted means is not required at the free end 36 to secure the elongate support member 32. The friction should be enough to over come the force of the current and maintain the appropriate position of the skimming apparatus 18. However, pools and side walls vary and therefore it may be necessary to add a weighted means on at the free end of the elongate support member 32. A weighted means, similar to the one used at the inlet end 22 of the first elongate member 20, is suitable for use with the free end 36.
Debris floating on the water surface is circulated around the pool by the current generated from the filtration system. FIG. 2 illustrates the skimming apparatus in use with direction arrows indicating the path of the surface debris. As the debris approaches the skimming apparatus 18, the debris is directed into the first elongate buoyant member 20 by the current and by the second elongate buoyant member 28. The debris collects upon the debris edge 26 of the first elongate buoyant member 20. The water passes under the first elongate buoyant member 20 while the debris remains on the debris edge 26. FIG. 3 is a cross sectional view illustrating the water passing under the first elongate buoyant member 20 while the debris remains at the surface.
The rounded pipe allows the water to pass under the first elongate buoyant member 20 while collecting the debris along the debris edge 26. The rounded pipe also reduces the skimming apparatus' resistance to the force of the current and thereby reduces the need for a fixed attachment or heavy weighted means.
In FIG. 4, the lip 46 formed by the optional plastic sheet 44 enhances the debris edge 26 while allowing the water to pass under the first elongate buoyant member 20 without a great amount of resistance. The enhanced debris edge extends below the water surface and prevents floating debris from being carried by the current under the first elongate buoyant member 20.
The current, in conjunction with the acute angle of the first elongate buoyant member 20, pushes the debris along the debris edge 26 and into the filtration inlet 14. The debris is then entrapped in the filter 16 of the filtration system where it then can be removed.
Upon removal of the surface debris, the skimming apparatus 18 is easily removed from the pool 10 by releasing the fastening rope 42 from the weighted object 40 and lifting the skimming apparatus 18 from the pool 10. The elongate support member 32 is rotated to a closed position so that the skimming apparatus 18 can be easily stored.
In accordance with the provisions of the patent statutes, the present invention has been described in what is considered to represent its preferred embodiment. However, it should be noted that the invention can be practiced otherwise than as specifically illustrated and described without departing from its spirit or scope. | A portable buoyant skimming apparatus for removing surface debris from a swimming pool. The skimming apparatus is positioned on the water surface of a pool near the inlet of the pool's filtration system. The water current from the filtration system carries surface debris into the buoyant skimming apparatus whereby the debris is directed into the filtration inlet. The light weight and portable skimming apparatus is made with tubular members so that the water carried into the apparatus moves under the tubular members while the floating debris remains at the surface. The skimming apparatus is easily installed and removed from the pool. | 4 |
FIELD OF INVENTION
[0001] This invention relates to wind turbines, and in particular to horizontal axis type wind turbines of large diameter.
BACKGROUND OF THE INVENTION—PRIOR ART
[0002] Conventional large horizontal axis wind turbines employ two or three long, slender blades cantilevered out from a central, horizontal axle that in turn is raised high in the air atop a tall, slender tower that cantilevers up from the earth's surface. One result: a small transverse wind force, X, exerted at the tip of a blade will create large (≈30X) tension (upwind) and compression (downwind) stress loads that the entire lengths of both blades and tower must be able to withstand.
[0003] Furthermore, in a conventional horizontal axis wind turbine, power is taken off at the axis of blade rotation, at an RPM that must vary inversely with blade length to avoid an excessive tip speed. The lower RPM associated with greater blade length requires a proportionately heavier axis bearing to support blade rotation, and a heavier gearbox, or if gearless, a larger and heavier generator structure, to produce energy at the power line frequency.
[0004] Wind turbine U.S. Pat. No. 4,417,853, drawing #12 (copy enclosed) shows two potential means for reducing the cost of extracting energy from the wind: 1) Small wheels at the turbine perimeter take off the useful power output from the wind at an initial RPM far higher than the RPM of blade rotation. 2) Upwind perimeter “stay” cables withstand the wind force exerted on the blade area with far less stress than the stress levels experienced by cantilever beam blades sweeping through the same area. However, the intricate cloth blade furling system shown in U.S. Pat. No. 4,417,853 has not proven suitable for large wind turbines.
SUMMARY OF THE INVENTION
[0005] To make possible a much larger power output, the present invention replaces the furling cloth sails of U.S. Pat. No. 4,417 853, with blades having a more conventional airfoil shape, that are supported within a surrounding structure which can counter wind force exerted on the blades with far less weight than is needed by the conventional combination of cantilever beam blades, set atop a cantilever beam type tower.
[0006] In a preferred option, the airfoil shaped blades of this invention extend from a common center of rotation, out to the inner ring of two concentric, nested rings. The inner ring attached to the blades is able to move smoothly through the interior of the outer nested ring by means of a rolling contact of the inner ring with a sufficient number of wheel mounted tires that drive rotation of multiple generators, and air compressors (?) mounted at intervals around the internal surface of the outer nested ring. This enables producing a useful power output at a far higher initial RPM than the RPM of blade rotation, in response to the wind's force.
[0007] Individual blades as used in this invention can range in design from simple, impact air inflated, cloth airfoils whose angle of incidence to local airflow cannot be changed, to multiple, tandem, rigid airfoil segments, each of whose trailing edge flaps can be rotated in unison by a central actuator, to a common angle of attack to local airflows, as a means of maximizing recovery of energy from wind transiting the blade system. (Impact air inflated cloth airfoils have the advantage of weighing a tiny fraction of the weight needed for cantilever beam blades, and are easily made retractable for protection from severe weather.)
[0008] “Stay” cables extend from between adjacent segments of the light weight airfoils made possible by this invention, fore and aft to ancillary structure having the depth and arrangement needed to directly absorb the axial force that the wind exerts oh the blade system, with far less stress than is experienced by the blades of a cantilever beam blade system.
[0009] The space frame type structure for wind turbines as described in this invention, will greatly reduce the structural weight now needed to extract energy from the wind, and may enable the construction of wind turbines of much larger blade swept area than those currently available, that can intercept the wind at an increased height above ground level where the wind typically has a greater energy content.
[0010] Other features and advantages of the invention will be apparent from the following detailed description, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 , a side view of the wind turbine of this invention, illustrates that a substantial land area is needed for its deployment, in order to achieve a much lighter structure.
[0012] FIG. 2 is a partial longitudinal section, showing how a single turbine blade is supported in order to drive rotation of multiple generators mounted out along this wind turbine's circumference
[0013] FIG. 3 is a frontal view of the wind turbine, showing means for supporting nested perimeter rings in a vertical position, to enable their rotation in azimuth, into the current wind direction.
[0014] FIG. 4 shows a sea going version of this invention, with modifications that allow the wind turbine of this invention to operate in this more challenging environment.
[0015] FIG. 5 shows how a central actuator can cause multiple blade segment trailing edge flaps to rotate all segments to a uniform angle of attack to each segment's own, local airflow.
[0016] FIG. 6 shows how retractable air impact inflated blades can cover much smaller chord biplane blades, to better cope with a wide range of wind speeds and weather conditions.
[0017] FIG. 7 compares the stress levels experienced by a cantilever beam type wind turbine blade, with the stress levels experienced by the equivalent structure of this invention.
[0018] Final FIG. 12 is reproduced from U.S. Pat. No. 4,417,853, with additions to this figure to emphasize elements of U.S. Pat. No. 4,417,853 that are pertinent to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0019] As shown in FIG. 1 , the present invention is a cable-stayed, space frame-type horizontal axis wind turbine whose base extends out over a far larger area, land or sea, than is needed for base installation for a conventional horizontal axis wind turbine. FIG. 7 incorporates a stress analysis explaining why this broad base enables a major reduction in wind turbine stress loads developed in response to wind force.
[0020] FIG. 1 , and in more detail FIG. 2 , show how a radial array of blades segments 1 can extend from a horizontal axis of rotation 2 , out along radial cables 3 , to an inner ring 4 (see FIG. 2 ) that moves through the interior of outer ring 5 in pace with the rotation of blade segments 1 , in order to force the rotation of electrical generators 6 , and air compressors?, mounted circumferentially along the interior of outer ring 5 , at an initial RPM that can be 100 or more times the RPM of blade system rotation.
[0021] FIG. 1 illustrates that this major reduction in wind induced stress loads will require a base structure extending over a far larger land area that is occupied by the footing for a conventional HAWT, but can do so with little interference to the use of this same land area for farming and ranching.
[0022] In FIGS. 1 and 2 , wind force exerted on the blade system is reacted primarily by stays 7 that extend from multiple points along blade segments 1 , to the upper ends of fore and aft spars 8 , whose lower ends rest on a central pivot 9 , itself located at the ground level intercept of vertical axis line 10 , around which nested blade rings 4 , 5 rotate in azimuth to stay headed into the current wind direction.
[0023] Shroud cables 11 prevent spars 8 from being pulled upward by stay cable tension, by pulling upward on wheels 12 that roll in an inverted position along a suitable downward facing surface of flange 14 molded into curb 13 . Curb 13 is elevated on columns 16 to free the local land surface for use in farming and ranching. Curb lid 15 serves to keep the various elements riding the curb moving in unison, and also keeps the curb top clean.
[0024] In FIG. 1 , rings 4 and 5 are further supported for operation in a vertical position by lateral side spars 17 whose lower ends rest on jib cars 18 . Jib cars 18 use opposing wheels sets 19 to secure the lower ends of side spars 17 to suitable surfaces of curb 13 . Wheel sets 19 then allow rotation of side spars 17 , along with the blade system, into the current wind direction.
[0025] FIG. 2 depicts in more detail one of the many alternatives for blade structure that are made possible by this invention. In FIG. 2 , multiple light weight airfoils are supported. Sequentially as blade segments 1 , along radial cables 3 that extend from a common horizontal axis of rotation 2 , out through the length of blade segments 1 , to a lug 4 a attached, through a slot in outer ring 5 , to the inner edge of ring 4 , the inner ring of the two nested, concentric rings 4 and 5 that extend around the perimeter of the blade system of this invention.
[0026] Inner ring 4 is supported for circumferential rotation in step with blade segments 1 , through the interior of outer ring 5 , by engaging multiple air inflated tires on outer ring wheels 20 that drive power generating equipment distributed at regular intervals around the interior of outer nested ring 5 . If needed, idler wheels, not shown, can be interspersed between wheels 20 in the numbers needed to keep inner ring 4 moving smoothly through the interior of outer ring 5 .
[0027] An alternative arrangement eliminates the inner nested ring 4 and instead uses the blade system to drive rotation of tires on wheels that move with the blade system while bearing on appropriate surfaces of the remaining ring 5 , but this alternative seems likely to make the transfer of power output from tire/wheel driven generators to ground level much more difficult to accomplish reliably, and could eliminate wheel driven compression of air for energy storage.
[0028] In FIG. 2 , tension maintenance in the array of wind force absorbing stay cables 7 is achieved by terminating the front (windward) end of each stay cable 7 with a tensioning device, 21 mounted on a shield 22 that is rotatably mounted within a collar 23 located at the point of convergence of stay cables 7 at the upper end of each diagonal spar 8 . Vibration of stay cables 7 can be suppressed by surrounding their termini with viscous material. If additional damping is needed, adjacent stay cables 7 can be held together for that portion of their lengths where they run nearest each other, by means of cable clamps. ( 7 a ) having a viscous damping action, without substantial effect on the adjustment of tension in individual members of grouped stay cables 7 by tensioning devices 21 mounted on shield 22 , within collar 23 .
[0029] Wind force that is exerted on the outer nested ring 5 may require perimeter stays. 7 b that extend fore and aft from outer nested ring 5 to terminate on the same diagonal spar mounted collars 23 that support rotation of shields 22 in synchrony with rotation of fore and aft sets of stay cables 7 , along with the blade system.
[0030] FIG. 3 offers a frontal view, showing how for greater ground clearance, nested rings 4 and 5 can be supported on a sling cable 25 that hangs between the tops of two side spars 17 , which in turn rise from jib cars 18 , up near to lateral quadrant locations on outer ring 5 . Jib car 18 mounted hinge mechanisms 24 a and 24 b , in conjunction with a center pivot mounted hinge 24 c , will still allow the blade system of this, invention to be lowered from a vertical to a horizontal position for maintenance, and to reduce public annoyance when this wind turbine fails to rotate for lack of wind. Two smaller, V shape booms 26 , extend from center pivot 9 , via hinge 24 c , to appropriate points along outer ring 5 that will prevent any displacement of the blade system away from vertical axis 10 .
[0031] The wind turbine structure described above can be modified for offshore use as shown in FIG. 4 , by supporting nested rings 4 and 5 on a circular crib-like arrangement of two horizontal rings 32 and 33 , separated by multiple vertical columns 34 , wherein the lower ring 32 , and columns 34 have sufficient water displacement volume to support the weight of the entire structure to a depth which submerges lower ring 32 completely and columns 34 to an appropriate portion of their lengths to enable their use in recovering energy from transiting waves. Cables 35 moor this floating structure to the ocean floor. If greater resilience to severe storms is needed, sag weights 36 can be added to cables 35 . A separate tower 37 , if centrally positioned within this floating structure, can provide a protected means for sending a useful power output down to the sea bed for its further transport to shore and the point of use.
[0032] Ring 33 at the top of columns 34 can then support wind turbine structure 38 , by means which allow rotation of structure 38 into the current wind direction. This may consist of supporting the weight of wind turbine structure 38 on multiple, interconnected jib cars 18 that travel along the upper surface of upper ring 33 .
[0033] Wind turbine structure 38 differs from the land based version of this invention in requiring a replacement for diagonal spars 8 as a means of absorbing wind force exerted on the blade system via stay cables 7 . This may consist of: 1) a blade rotational, axis spar 39 that extends horizontally between opposite focal points for stay cables 7 , 2) four nearly vertical spars 40 whose lower ends rest on jib cars 18 and whose upper ends converge in pairs at the two focal points for stay cables 7 , and cables 41 that interconnect the foregoing elements into a structure that can rotate in azimuth into the current wind direction, and that will prevent the blade system from collapsing forward, should the wind suddenly reverse direction.
[0034] A major concern is that an extreme wave could exert enough lateral pressure on submerged ring 32 and columns 34 to overstress the sea bed anchoring system. This possibility can be minimized by:
[0035] 1) Submerging ring 32 to a sufficient depth to greatly diminish ring motion in response to the passage of a storm wave,
[0036] 2) By placing “sage” weights on tower anchor cables 35 at a suitable point along each cable in the direction of the arrow 36 , so that greater resilience is offered to wave side force exerted on lower ring 32 and column 34 .
[0037] Optionally, the rotation of inner nested ring 4 by the blade system may be used to drive rotation of air compressors as well as generators, in order to compress air for transmission to tower 37 and from there transmission to underground storage via passage through a volume of eutectic salt that is stored within tower 37 , for later recovery to meet system demand for electrical energy. Optionally, submerged ring 32 , and partially submerged columns 34 can support means 42 for extracting energy from wave motion in the surrounding water body, to supplement energy derived from the wind.
[0038] Many novel wind turbine blade systems are made possible by this invention. For one example, FIG. 5 shows how a central scissors mechanism, 27 , can induce radial motion of rods 28 that in turn, through linkages 29 , rotate the trailing edge elevators 30 of all blade segments 1 to achieve a uniform angle of incidence to each blade segment's local airflow, for the purpose of recovering maximum energy from the wind.
[0039] As a second example of the novel blade system made possible by this invention, FIG. 6 shows how blade segments 1 can consist of impact air inflated cloth blade segments for light winds that envelop much smaller chord biplane blade segments 31 , that 1) are able to resist stronger winds, and 2) can be made to resist a substantial portion of the centripetal component of stay cable tension that would otherwise be exerted on perimeter nested rings 4 and 5 . | The horizontal axis wind turbine of this invention has a space frame structure that enables a light weight blade system to force rotation of numerous small wheels into rolling contact with the surface of at least one ring that extends around the perimeter of said blade system. A portion of the wheels drive rotation of multiple small electrical generators, and air compressors (?), at a high initial RPM, in the numbers needed to produce this wind turbine's useful power output.
For offshore use, a wind turbine structure as described above surmounts two horizontal toroidal members held apart by multiple vertical columns. The lower toroidal member and the vertical columns above this member float at a depth that is nearly half the column heights. Added structure enables the extraction of energy from waves transiting the vertical columns. | 8 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] This invention relates to the field of military vehicles and more specifically to the field of blast protection systems for military vehicles.
[0005] 2. Background of the Invention
[0006] There is an increasing need for added protection for occupants of military vehicles. Improvised explosive devices and other methods for attacking military vehicles have drawn added interest in the safety of occupants of military vehicles. Conventional methods for protecting occupants of the vehicles include reliance on the outer minor of the military vehicles. Drawbacks to such conventional methods include instances in which force from the explosive devices enters the interior of the military vehicle, which may place occupants of the military vehicle at severe risk of injury or death.
[0007] Methods have been developed to overcome such drawbacks. For instance, reactive armor on the outside of the military vehicle and body armor worn by the occupants of the military vehicle have been developed. Drawbacks to such developments also include risk of injury or death when the explosive forces enter the interior of the military vehicle.
[0008] Consequently, there is a need for improved methods for protecting occupants of military vehicles from explosive forces.
BRIEF SUMMARY OF SOME OF THE PREFERRED EMBODIMENTS
[0009] These and other needs in the art are addressed in one embodiment by a blanket protection system adaptable for use in a military vehicle. The blanket protection system includes a blanket comprising a carrier, a ballistic insert, stitch lines, and a plurality of buckles. In addition, a portion of the stitch lines extend between at least a portion of the plurality of buckles. The carrier comprises an interior. In addition, the ballistic insert is disposed in the interior.
[0010] The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter that form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and the specific embodiments disclosed may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] For a detailed description of the preferred embodiments of the invention, reference will now be made to the accompanying drawings in which:
[0012] FIG. 1 illustrates a front view of a blanket with a carrier and stitch lines;
[0013] FIG. 2 illustrates a second blanket of the blanket protection system having stitch lines;
[0014] FIG. 3 illustrates a third blanket of the blanket protection system having stitch lines;
[0015] FIG. 4 illustrates a storage unit;
[0016] FIG. 5 illustrates the front interior side of the blanket of FIG. 1 ;
[0017] FIG. 6 illustrates the front interior side of the blanket of FIG. 1 showing the stitch lines; and
[0018] FIG. 7 illustrates the ballistic insert for the blanket of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0019] FIG. 1 illustrates blanket protection system 1 having blanket 5 . FIG. 1 illustrates the front side of blanket 5 . Blanket 5 may have any desirable configuration. In an embodiment as illustrated in FIG. 1 , blanket 5 has a configuration suitable for placement in the interior of a military vehicle between an occupant of the vehicle and the engine compartment of the vehicle. In some embodiments, the occupant is the driver of the military vehicle. It is to be understood that blanket 5 is not limited to the configuration illustrated in FIG. 1 but includes other configurations in alternative embodiments. For instance, in some alternative embodiments (not illustrated), blanket 5 has a configuration suitable for protecting a desired interior portion of a military vehicle.
[0020] Blanket 5 includes carrier 10 and has an interior (not illustrated) in which a ballistic insert 175 (illustrated in FIG. 7 ) is disposed. Carrier 10 is an outer bag having the interior. Carrier 10 may be composed of any materials suitable for use in a military vehicle. In an embodiment, carrier 10 is composed of flame retardant and/or fluid resistant materials. Without limitation, the flame retardant materials provide further protection against explosive forces. Further, without limitation, the fluid resistant materials protect the interior of carrier 10 and contents therein from fluids. For instance, the fluid resistant materials protect ballistic insert 175 from potential damage from fluids. In some embodiments, carrier 10 is coated with flame retardant and/or fluid resistant materials. The interior of carrier 10 is accessible along top portion 30 . In an embodiment, the interior is accessible along any suitable portion of top portion 30 to allow access to the interior and to allow desired inserts such as ballistic insert 175 to be inserted therein. Carrier closure means 15 is operable to open and close access to the interior. Carrier closure means 15 includes any suitable means for closing the access. Examples of carrier closure means 15 include buttons, clamps, a zipper, and the like. In an embodiment, carrier closure means 15 include a zipper. Without limitation, a zipper facilitates a quick and easy method for opening and closing access to the interior. In an embodiment as illustrated in FIG. 1 , carrier closure means 15 includes closure means strap 25 . In an alternative embodiment, carrier closure means 15 is a means for sealing access to the interior from fluids. In some embodiments, blanket 5 is not openable and closeable. In such an embodiment, ballistic insert 175 is disposed within the interior of blanket 5 .
[0021] As further shown in FIG. 1 , blanket 5 includes buckles 20 . Buckles 20 releasably attach blanket 5 to a wall or other structure in the military vehicle. In an embodiment, buckles 20 are quick release buckles. It is to be understood that quick release buckles refer to buckles that are quickly released from attachment to the wall or other structure. Without limitation, quick release buckles allow occupants of the vehicle to quickly attach and quickly release blanket 5 from the vehicle. It is to be understood that in many situations the occupants (soldiers) of the vehicle must release blanket 5 with little effort and time involved. For instance, blanket 5 may provide protection to occupants from the engine compartment of a military vehicle and access to the engine compartment may be needed. Releasing at least a portion of blanket 5 with buckles 20 (quick release buckles) facilitates access to the engine compartment. Buckles 20 may be releasably attached to the military vehicle by any suitable means. In an embodiment, attachment buckles (not illustrated) are secured to the military vehicle, and buckles 20 are releasably attached to the attachment buckles. The attachment buckles may be secured to the military vehicle by any suitable means. In an embodiment, the attachment buckles are secured to the military by adhesive. Without limitation, a commercial example of a suitable adhesive is CB200, which is commercially available from Click Bond, Inc. Buckles 20 include straps 185 , which are attachable to blanket 5 . Straps 185 may be composed of any materials suitable for use in a military vehicle. In an embodiment, straps 185 include flame resistant materials. Without limitation, the flame resistant materials facilitate straps 185 in maintaining attachment of blanket 5 to the military vehicle when exposed to extreme heat, such as in an explosion. An example of a suitable commercial example of a flame resistant material is KEVLAR, which is commercially available from E. I. du Pont de Nemours and Company. Blanket 5 may include any number of buckles 20 suitable for releasably attaching blanket 5 to the military vehicle.
[0022] FIG. 1 illustrates an embodiment of blanket 5 in which carrier 10 include stitch lines 70 . In the embodiment as shown, stitch lines 70 extend from a strap 185 to each proximate strap 185 and also extend in the direction of the side of blanket 5 opposing the particular strap 185 . In some embodiments as illustrated in FIG. 1 , a portion of the straps 185 have stitch lines 70 that extend to a strap 185 on an opposing side of blanket 5 . Without limitation, stitch lines 70 provide blanket 5 with added strength when exposed to explosion. For instance, stitch lines 70 extending between straps 185 increase the strength in which straps 185 are attached to blanket 5 and thereby facilitate straps 185 remaining attached to blanket 5 when exposed to forces from an explosion. In an embodiment, stitch lines 70 are sewn into carrier 10 on the interior of carrier 10 . FIG. 6 illustrates a view of an embodiment of the interior of front side of carrier 10 . As shown, stitch lines 70 provide cross-stitching 165 . Cross-stitching 165 refers to locations where stitch lines 70 cross each other. Without limitation, cross-stitching 165 provides further strength to carrier 10 by providing enhanced areas of stitching. Stitch lines 70 may be composed of any material suitable for use as a stitching material. In an embodiment, stitch lines 70 include flame resistant materials. In some embodiments, carrier 10 includes reinforcement means 160 . Reinforcement means 160 are sewn into carrier 10 by stitch lines 70 . Reinforcement means 160 may be any suitable material for improving protection against a blast. For instance, reinforcement means 160 provide added strength and further protection against blast fragments contacting carrier 10 . In an embodiment, reinforcement means 160 include a fabric. In some embodiments, reinforcement means 160 include nylon fabric. In an embodiment, reinforcement means 160 are in the form of a web.
[0023] In an embodiment as illustrated in FIG. 1 , blanket 5 includes pockets. Blanket 5 may include any suitable number and type of pockets. In the embodiment as illustrated, blanket 5 includes flashlight pocket 45 , pockets 50 , and molle strip pocket 55 . Flashlight pocket 45 is a pocket suitable for a flashlight. As shown, in some embodiments, flashlight pocket 45 is angled to facilitate retrieval and placement of a flashlight in flashlight pocket 45 . Pockets 50 may be any type of pocket suitable for use in a military vehicle. Molle strip pocket 55 is a pocket with molle strips 60 disposed on an outer portion of molle strip pocket 55 . Molle strip pocket 55 may contain any suitable number of molle strips 60 .
[0024] In some embodiments, blanket 5 also includes protection panels. In an embodiment as illustrated in FIG. 1 , blanket 5 includes protection panel 35 , protection panel 40 , and protection panel 65 . Protection panels may be composed of any material suitable for protecting blanket 5 against wear. In an embodiment, the protection panels are leather. The protection panels may be placed at any desirable location on blanket 5 . In some embodiments, protection panels are placed at locations in which wear is desired to be protected against. For instance, the protection panels are placed in high contact areas of blanket 5 .
[0025] In an embodiment as illustrated in FIG. 1 , blanket 5 also includes blanket connection means 85 and connection flap 75 . Blanket connection means 85 include any means for releasably connecting blanket 5 to another blanket such as second blanket 90 (illustrated in FIG. 2 ). Examples of blanket connection means 85 include buttons, clamps, a zipper, and the like. In the embodiment illustrated in FIG. 1 , blanket connection means 85 include a zipper. Connection flap 75 includes flap connection means 80 . Flap connection means 80 includes any means for releasably connecting blanket 5 to another blanket such as second blanket 90 . Examples of flap connection means 85 include buttons, clamps, a zipper, VELCRO (commercially available from Velcro Industries B.V.), and the like. Flap connection means 85 provide protection against contact and wear to blanket connection means 85 .
[0026] FIG. 2 illustrates a view of front side 195 of second blanket 90 . Second blanket 90 includes second blanket carrier 110 . Second blanket carrier 110 may be composed of any materials suitable for use in a military vehicle. In an embodiment, second blanket carrier 110 is composed of flame retardant and/or fluid resistant materials. Without limitation, the flame retardant materials provide further protection against explosive forces. Further, without limitation, the fluid resistant materials protect the interior of second blanket carrier 110 and contents therein from fluids. For instance, the fluid resistant materials protect ballistic insert 175 from potential damage from fluids. In some embodiments, second blanket carrier 10 is coated with flame retardant and/or fluid resistant materials.
[0027] In some embodiments, blanket protection system 1 includes blanket 5 and second blanket 90 , with blanket 5 and second blanket 90 releasably attached to each other by blanket connection means 85 and first blanket connection means 95 and/or flap connection means 80 . First blanket connection means 95 may include any means suitable for releasably attaching second blanket 90 to another blanket such as blanket 5 . Examples of first blanket connection means 95 include buttons, clamps, a zipper, and the like. In the embodiment illustrated in FIG. 2 , first blanket connection means 95 is a zipper. In an embodiment, first blanket connection means 95 include connection means strap 100 . Second blanket 90 may have any configuration suitable for a desired location in a military vehicle. In an embodiment, second blanket 90 is disposed over a radio access panel of a military vehicle. In some embodiments, blanket protection system 1 includes first blanket 5 releasably attached to second blanket 90 with first blanket 5 having a configuration suitable for providing protection against an explosion coming from the engine room of the military vehicle, and second blanket 90 having a configuration suitable for providing protection against an explosion coming from a radio access panel of the military vehicle. Second blanket 90 includes buckles 20 with straps 185 for releasably attaching second blanket 90 to the military vehicle. Second blanket 90 may also include protection panels 65 or any other protection panels. In an embodiment, a ballistic insert 175 is disposed in an interior of second blanket 90 . In an embodiment as illustrated, second blanket 90 is not openable and closeable but instead has a closed interior with ballistic insert 175 disposed therein. In alternative embodiments (not illustrated), second blanket 90 is openable and closeable.
[0028] In some embodiments, blanket protection system 1 includes blanket 5 releasably attached to second blanket 90 , and second blanket 90 releasably attached to another blanket such as third blanket 115 (illustrated in FIG. 3 ). In such embodiments, second blanket 90 includes second blanket connection means 105 , which is suitable for attachment of second blanket 90 to third blanket 115 . Examples of second blanket connection means 105 include buttons, clamps, a zipper, and the like. In the embodiment illustrated in FIG. 2 , second blanket connection means 105 are a zipper. In an embodiment, second blanket connection means 105 include connection means strap 100 .
[0029] FIG. 3 illustrates a view of front side 200 of third blanket 115 . Third blanket 110 also includes a carrier 10 that is openable and closeable. Third blanket 115 includes third blanket connection means 120 . Third blanket connection means 120 include any means suitable for releasably attaching third blanket 115 to another blanket such as second blanket 90 . Examples of third blanket connection means 120 include buttons, clamps, a zipper, and the like. In the embodiment illustrated in FIG. 3 , third blanket connection means 120 is a zipper. In an embodiment, third blanket connection means 120 includes connection means strap 100 . Third blanket 115 may have any configuration suitable for a desired location in a military vehicle. In an embodiment, third blanket 115 is disposed over the dog house of a military vehicle. It is to be understood that the dog house refers to the personnel carrier portion of the vehicle. In some embodiments, blanket protection system 1 includes first blanket 5 releasably attached to second blanket 90 and with second blanket releasably attached to third blanket 115 . In such embodiments, first blanket 5 may have a configuration suitable for providing protection against an explosion coming from the engine room of the military vehicle, second blanket 90 may have a configuration suitable for providing protection against an explosion coming from a radio access panel of the military vehicle, and third blanket 115 may have a configuration suitable for providing protection against an explosion coming from the dog house of the military vehicle. Third blanket 115 includes buckles 20 with straps 185 for releasably attaching third blanket 115 to the military vehicle. Third blanket 115 may also include protection panels 65 or any other protection panels. In an embodiment, a ballistic insert 175 is disposed in an interior of third blanket 115 .
[0030] In an embodiment as illustrated in FIG. 3 , third blanket 115 is openable and closeable. The interior of third blanket 115 is accessible along top portion 205 . In an embodiment, the interior is accessible along any suitable portion of top portion 205 to allow access to the interior and to allow desired inserts such as ballistic insert 175 to be inserted therein. Third blanket 115 also includes third blanket carrier closure means 130 . Third blanket carrier closure means 130 is operable to open and close access to the interior. Third blanket carrier closure means 130 include any suitable means for closing the access. Examples of third blanket carrier closure means 130 include buttons, clamps, a zipper, and the like. In an embodiment, third blanket carrier closure means 130 include a zipper. In an embodiment as illustrated in FIG. 3 , third blanket carrier closure means 130 include closure means strap 135 . In an alternative embodiment, third blanket carrier closure means 130 is a means for sealing access to the interior from fluids. In some embodiments, third blanket 115 is not openable and closeable. In such an embodiment, ballistic insert 175 is disposed within the interior of third blanket 115 .
[0031] FIG. 4 illustrates an embodiment of blanket protection system 1 including storage unit 140 . Storage unit 140 may include any configuration suitable for storing the blankets (i.e., blanket 5 , second blanket 90 and/or third blanket 115 ). In an embodiment as illustrated, storage unit 140 allows blanket protection system 1 to be stored and transported. The blankets may be stored in the interior of storage unit 140 . In an embodiment, storage unit 140 includes carrier straps 145 , which facilitate transportation of storage unit 140 . In some embodiments, carrier straps 145 are suitable for allowing storage unit 140 to be transported on the back of a carrier (i.e., soldier). In some embodiments, storage unit 140 may be openable and closeable. In such embodiments, closure means 150 are operable to open and close access to the interior. Closure means 150 include any suitable means for closing the access. Examples of closure means 150 include buttons, clamps, a zipper, and the like. In an embodiment, closure means 150 include a zipper. In an embodiment as illustrated in FIG. 4 , closure means 150 include closure strap 155 .
[0032] FIG. 5 illustrates a view of the interior of front side of blanket 5 . In such an embodiment, blanket 5 includes ballistic connection means 170 . Ballistic connection means 170 include any means suitable for attaching ballistic insert 175 to carrier 10 . For instance, examples of suitable ballistic connection means 170 include buttons, clamps, a zipper, VELCRO, and the like. It is to be understood that embodiments of second blanket 90 and third blanket 115 also include ballistic connection means 170 .
[0033] FIG. 7 illustrates an embodiment of ballistic insert 175 . Ballistic insert 175 includes any materials suitable for stopping or reducing the velocity of projectiles. In an embodiment, ballistic inset 175 includes aramid fibers. A commercial example of suitable materials includes KEVLAR. In an embodiment, ballistic insert 175 is coated and/or covered in a fluid resistant material. Ballistic insert 175 may have any suitable configuration. In an embodiment, ballistic insert 175 has a configuration that is similar to that of the blanket in which it is disposed. Without limitation, such an embodiment improves the protection capability of the blanket as the similar configuration of ballistic inert 175 maximizes protection within the configuration of the blanket. It is to be understood that the configuration of the embodiment of ballistic insert 175 illustrated in FIG. 1 is suitable for blanket 5 . In some embodiments, ballistic insert 175 includes ballistic insert connection means 180 . Ballistic insert connection means 180 include any suitable means for attaching ballistic insert 175 to a blanket (i.e., by attachment with ballistic connection means 170 ). For instance, examples of suitable ballistic insert connection means 180 include buttons, clamps, a zipper, VELCRO, and the like. It is to be understood that ballistic insert 175 is not limited to ballistic insert connection means 180 but instead may be attached to a blanket by any suitable means. In embodiments, ballistic insert 175 is attached to a blanket (i.e., such as blanket 5 , second blanket 90 , and/or third blanket 115 ) by being sewn to a blanket.
[0034] The military vehicle may be any type of military vehicle. In some embodiments, the military vehicle is an armored personnel carrier. In an embodiment, the military vehicle is a LAV-25, which is commercially available from General Dynamics. In an embodiment, blanket protection system 1 provides protection to the driver of the military vehicle.
[0035] It is to be understood that blanket protection system 1 is not limited to blanket 5 , second blanket 90 , and/or third blanket 115 . In alternative embodiments, blanket protection system 1 may include at least one additional blanket.
[0036] Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of the invention as defined by the appended claims. | A blanket protection system that is adaptable for use in a military vehicle. The blanket protection system includes a blanket comprising a carrier, a ballistic insert, stitch lines, and a plurality of buckles. The portion of the stitch lines extend between at least a portion of the plurality of buckles. In addition, the carrier comprises an interior. Moreover, the ballistic insert is disposed in the interior. | 5 |
TECHNICAL FIELD
[0001] The invention is in the field of methods and compositions for topical application to induce sleep or a relaxation state.
BACKGROUND OF THE INVENTION
[0002] Agitation, stress, and insomnia plague many people particularly with the pressures of modern life. There are a wide variety of ingestibles that promote relaxation or sleep inducement. Chamomile tea is well known to promote relaxation and induce sleep. There are also herbs and vitamins that are effective for this purpose. For example, melatonin, Passion Flower, Valerian extract, and St. John's Wort are well known for their ability to induce a relaxation state. Other options include prescription pharmaceuticals, many of which can be addictive and have other harmful effects.
[0003] The current trend is “natural” and ‘organic”. People want to use products that are not only safe for them but environmentally friendly in that the products are biodegradable, contain raw materials that are green, or are sold in packaging that is not synthetic. This is particularly desirable when it comes to products that may be used to induce relaxation. It is most desirable to have products that can be applied topically and sensory qualities that provide a relaxation state.
[0004] Unexpectedly, it has been discovered that a certain blend of plant oils is excellent for inducing a state of relaxation and sleep, causing a reduction in stress level, encouraging relaxation, improving the quality of sleep and promoting the general ability to unwind or soothe yourself so that sleep and/or relaxation states can be attained more easily.
[0005] It is an object of the invention to provide a composition for topical application that induces relaxation and reduces stress levels.
[0006] It is another object of the invention to provide a composition for topical application that promotes sleep.
[0007] It is another object of the invention to provide a method for inducing relaxation or sleep by topically applying a composition containing a certain blend of plant oils.
SUMMARY OF THE INVENTION
[0008] The invention is directed to a topical composition for inducing relaxation upon application to skin comprising a plurality of plant extracts which, together, have a Contingent Negative Variation (CNV) value ranging from about −1 to about −100.
[0009] The invention is also directed to a topical composition for inducing relaxation upon application to skin comprising a mixture of mandarin oil, lavender oil, chamomile oil, and optionally sweet almond oil.
[0010] The invention is further directed to an environmentally scented product for inducing relaxation comprising a mixture of mandarin oil, lavender oil, chamomile oil, and, optionally, sweet almond oil.
[0011] The invention is further directed to a method for inducing sleep by topically applying a composition comprising a mixture of mandarin oil, lavender oil, chamomile oil, and optionally sweet almond oil.
[0012] The invention is further directed to a method for inducing relaxation by topically applying a composition comprising a mixture of mandarin oil, lavender oil, chamomile oil, and optionally sweet almond oil.
[0013] The invention is further directed to a method for inducing relaxation by providing an environmentally scented product comprising a mixture of mandarin oil, lavender oil, chamomile oil, and optionally sweet almond oil.
DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 depicts the before and after test results of saliva samples collected from panelists before and after exposure to the Mixture (as defined below).
[0015] FIG. 2 depicts the reduction in cortisol in saliva samples as a result of exposure to the Mixture.
DETAILED DESCRIPTION
I. The Mixture
[0016] The relaxation and sleep inducing properties of the topical compositions of the invention are due to a mixture of certain plant materials that, when combined, provide a CNV of −1 to about −100 when tested according to standard CNV test protocol (as referenced in The Psychophysiological Effects of Odors, Aromachology—Review of the Latest Researches on the Effects of Odors, Takasago International, November 1991). Specifically, CNV is measured by attaching electrodes to the scalp to monitor shifts in brain waves both before and after the test subject has sniffed a particular fragrance. The test is performed repeatedly, e.g. 10-20 trials, after which the results are averaged. The ability of a fragrance to cause a decrease in CNV (that is less a CNV value less than zero) means that the fragrance is a sedative. When the CNV is increased, that is, has a value greater than zero, the fragrance is a stimulant. While a specific ingredient may itself provide a positive CNV, when it is combined with other ingredients that may either have a positive or negative CNV, the mixture could have a negative CNV. This is why the CNV measurement must be determined by testing the mixture or the individual ingredient that is to be incorporated into the composition. One cannot assume that a combination of ingredients with a negative CNV value will each individually have a negative CNV.
[0017] In one preferred embodiment, a suitable composition comprises mandarin oil, lavender oil, chamomile oil, and optionally sweet almond oil (the “Mixture”). Preferably the oils range from about 1-45% mandarin oil, 1-45% lavender oil, 1-45% chamomile oil, and, if present 1-45% sweet almond oil. The oils are obtained by extraction from mandarin orange, lavender, chamomile, and almonds. One of the Mixtures may be purchased from Takasago Corporation, Rockleigh, N.J., under the trade name “RT-3347 Mod 1F” which is a mixture of mandarin oil, lavender oil, chamomile oil, and sweet almond oil. Another Mixture may be purchased from Takasago Corporation under the tradename “RU-1766” which is a mixture of mandarin oil, lavender oil, and chamomile oil. Preferably from about 0.01 to 60%, more preferably from about 0.05 to 30%, most preferably from about 0.1 to 25% of the Mixture is used in the compositions of the invention. All percentages mentioned herein are percentages by weight unless otherwise indicated.
II. The Composition
[0018] The mixture of oils is incorporated into compositions that may be applied topically to the body, face, lips, nails or hair. The composition may be in the anhydrous form or in the aqueous gel or emulsion form. If in the aqueous gel form, the composition comprises from about 0.1 to 99.5% water. If in the emulsion form, the composition may be a water in oil or oil in water emulsion comprising from about 0.5 to 95%, preferably, 1 to 85%, more preferably from about 5 to 80% water; and from about 0.5 to 95%, preferably from about 1 to 85%, more preferably from about 5 to 80% oil.
[0019] A. Oils
[0020] Suitable oils may include silicone oils, natural plant oils, organic oils, hydrocarbon oils, and the like. The term “oil” means an ingredient that is preferably pourable at room temperature (e.g. 25° C.).
[0021] 1. Silicone Oils
[0022] Suitable silicone oils include volatile or non-volatile silicones. The term “volatile” means that the silicone has a vapor pressure of greater than about 2 mm of mercury at 20° C. The term “nonvolatile” means that the silicone has a vapor pressure of less than about 2 mm. of mercury at 20° C. Suitable volatile silicones may be linear or cyclic. Examples of linear volatile silicones include hexamethyldisiloxane (0.5 centstokes), octamethyltrisiloxane (1.0 centistokes), decamethyltetrasiloxane (1.5 centistokes), and dodecamethylpentasiloxane (2.0 centistokes). Examples of cyclic volatile silicones include octamethylcyclotetrasiloxane, decamethyltetracyclosiloxane, dodecamethylpentasiloxane, and the like. Examples of nonvolatile silicones include dimethicone, phenyl dimethicone, phenyl trimethicone, trimethylsiloxyphenyldimethicone, cetyl dimethicone, and the like. If present the silicone oils may range from about 0.1 to 85%.
[0023] 2. Natural Plant Oils
[0024] Also suitable as the oil component are one or more natural plant oils including oils from the fruits, seeds, roots, or other parties of plants such as sunflower, safflower, jojoba, olive, soybean, coconut, castor, canola, palm, sesame, macadamia, mango, rice, and so on. If present such oils may range from about 0.5 to 99%, preferably from about 1-95%, more preferably from about 5 to 85% of the composition.
[0025] B. Alcohols
[0026] The compositions of the invention may also contain one or more mono-, di-, or polyhydric alcohols. If present, ranges may be from about 0.1 to 99%, preferably from about 0.5 to 95%, more preferably from about 3 to 90%.
[0027] Suitable monohydric alcohols include C2-20 aliphatic or aromatic mono hydroxyl substituted alcohols such as ethanol, propanol, butanol, bisabolol, benzyl alcohol, and mixtures thereof.
[0028] Suitable dihydric alcohols include C 2-6 alkylene glycols such as ethylene glycol, propylene glycol, butylene glycol, pentylene glycol, hexylene glycol, and mixtures thereof.
[0029] Suitable polyhydric alcohols include glycerin, or sugar alcohols such as erythritol, arabitol, xylitol, ribitol, or mixtures thereof.
[0030] C. Fatty Acids
[0031] The composition may contain one or more fatty C 6-30 carboxylic acids that may be aliphatic, aromatic, saturated or unsaturated. Such fatty acids may be liquid or solid at room temperature and include stearic, isostearic, palmitic, behenic, lauric, linoleic, linolenic, myristic, oleic, ricinoleic, or mixtures thereof. If present, the fatty acid may range from about 0.1 to 40%, preferably from about 0.5 to 35%, more preferably from about 0.5 to 25% of the composition.
[0032] D. Fatty Alcohols
[0033] The composition may also contain one or more fatty C12-30 alcohols such as cetyl, behenyl, caprylic, cetearyl, stearyl, isostearyl, oleyl, linoleyl, lauryl alcohols and mixtures thereof. If present the fatty alcohol may range from about 0.1 to 65%, preferably from about 0.5 to 60%, more preferably from about 1 to 50% of the composition.
[0034] E. Structuring Agent
[0035] The composition may also contain one or more structuring agents which may act as thickeners for the aqueous phase of the composition, when such compositions are in the aqueous form. If present the structuring agent may range from about 0.1 to 35%, preferably from about 0.5 to 30%, more preferably from about 1 to 25% of the composition. Suitable structuring agents include synthetic polymers that may be homo- or copolymers of acrylic acid, methacrylic acid, or their simple C1-6 alkyl esters or acrylamides. These polymers may be crosslinked Examples of such agents include carbomer (a homopolymer of acrylic acid crosslinked with a polyfunctional agent which may be the allyl ether of sucrose, pentaerythritol, or propylene), C10-30 alkyl acrylate crosspolymer, acrylamide sodium acrylate copolymer, acrylamide sodiumacryloyldimethyltaurate copolymer, acrylates steareth-20 methacrylate copolymer, acrylamides copolymer, acrylates vinylneodecanoate crosspolymer, and so on.
[0036] Also suitable are naturally occurring or synthetic gums or hydrocolloids including but not limited to agar, algin, cellulose, xanthan gum, chitin, and mixtures thereof.
[0037] F. Esters of Polyols or Alkylene Glycols
[0038] It may also be desirable to include one or more emulsifying agents in the form of polyol esters of esters of C2-4 alkylene glycols. More preferred is a C 2-4 alkylene glycol or polyol ester of a C 12-30 fatty carboxylic acid. The alkylene glycol may preferably be ethylene or propylene glycol having from about 2 to 200 repeating units, and the fatty carboxylic acid is selected from stearic acid or isostearic acid. Most preferred are esters of polyols such as glycerin and C2-4 alkylene glycols such as ethylene glycol, and where the fatty carboxylic acid is stearic or isostearic acid. Examples of such ingredients include glyceryl stearate, diglyceryl diisostearate, PEG-2-100 stearate or isostearate, and the like. Most preferred is glyceryl stearate, PEG-100 stearate or mixtures thereof. If present such emulsifying agents may range from about 0.1 to 40%, preferably from about 0.5 to 35%, more preferably from about 0.5 to 30% of the composition.
[0039] G. Alkoxylated Alcohols It may also be desirable to incorporate various types of alkoxylated alcohols in to the composition. If present, suggested ranges are from about 0.1 to 30%, preferably from about 0.5 to 25%, more preferably from about 1 to 20% of the composition. Suitable alkoxylated alcohols include C 6-30 aromatic or aliphatic fatty alcohols that may be unsaturated or saturated, which are reacted with alkoxy groups, preferably ethoxy or propoxy groups having from about 1 to 200 repeating ethoxy or propoxy units. Examples of fatty alcohols include cetyl, stearyl, isostearyl, behenyl, myristyl, and the like. Such alkoxylated alcohols may have from about 1 to 200 repeating ethoxy or propoxy groups. Examples include ceteareth, beheneth, steareth, isosteareth, and the like where the number of repeating ethoxy groups ranges from about 2 to 200.
[0040] H. Botanical Extracts
[0041] The composition may contain one or more botanical extracts derived from plant seeds, fruit, pulp, root, or leaves. Examples include extracts from the Siegesbeckia Orientalis, Acmella Oleracea, Calluna, Ascophyllum, Helianthus, Triticum, Olea, Astrocaryum, Ononotus, Menyanthes, Cladosiphon, Silybum, Cocos, Carthamus , genuses and the like. More specific examples of suitable extracts include Siegesbeckia, Castanea Sativa, Acmella, Calluna, Ascophyllum Nodosum, Helianthus Annus, Triticum Vulgare, Olea Europa, Astrocaryum Murumuru, Ononotus Obliquus, Menyanthes Trifoliata, Cladosiphon Okamuranas, Silybum Marianum, Cocos Nucifera, Carthamus Tinctorius , and mixtures thereof. If present such botanical extracts may range from about 0.001 to 20% of the composition.
[0042] I. Vitamins or Antioxidants
[0043] The composition may also contain one or more vitamins or antioxidants. If present they may range from about 0.001 to 10% of the composition. Suitable vitamins include E, C, A, K, D, or derivatives thereof. Examples include tocopheryl acetate, tocopherol maleate, ascorbyl palmitate, magnesium ascorbyl phosphate, or mixtures thereof.
[0044] II. The Products
[0045] The compositions of the invention may be in the form of bath or body oils, facial or body creams or lotions, hand or body lotions, sprays, aromatherapy products and the like.
[0046] For example, one preferred composition is bath oil for use in pouring into bath water prior to bathing such that the oils and active ingredients present in the bath water will coat the skin and provide an aroma that will induce relaxation. The bath oil is preferably anhydrous and has from about 5 to 99% of oils, preferably naturally occurring plant oils, and from about 0.1 to 20% of the Mixture.
[0047] Another preferred composition is a facial cream to be applied to the face prior to sleep or inducement of the relaxation state. Such cream is preferably in the water and oil emulsion form comprising from about 0.5 to 95%, preferably, 1 to 85%, more preferably from about 5 to 80% water; and from about 0.5 to 95%, preferably from about 1 to 85%, more preferably from about 5 to 80% oil. The oils may be any of the oils set forth above with respect to the composition and in the percentages stated. Most preferred is a facial cream comprising:
[0048] 20 to 95% water, 0.1 to 20% of a dihydric or polyhydric alcohol, 0.1 to 40% dimethicone, 0.01 to 20% carbomer, 0.1 to 10% fatty acids, from about 0.01 to 20% botanical extracts.
[0049] Another preferred composition is a body balm applied to face and skin prior to retiring or the time when it is desired to induce a relaxation state. The balm preferably is in the emulsion form and comprises from about 50-95% water, 0.5 to 15% of an ester of an alkylene glycol or polyol and a fatty carboxylic acid as described herein, from 0.1 to 10% of the Mixture, from about 0.001 to 20% dimethicone, and from about 0.01 to 10% of one or more dihydric alcohols, and from about 0.1 to 40% of an aqueous phase structuring agent that is a synthetic polymer comprised of acrylic acid, methacrylic, acid or their simple esters, or acrylamide; or one or more hydrophilic colloids such as xanthan gum.
[0050] Another type of composition may be in the form of a spray applied to the body using a spritzer device or similar. Such a spray is generally aqueous based and comprises from about 5 to 99% water, from about 5 to 80% of one or more mono-, di-, or polyhydric alcohols, and the Mixture.
[0051] The following more specific examples of suitable compositions are set forth for the purposes of illustration only.
Example 1
[0052]
[0000]
% by weight
Night
Night
Bath
Ingredient
Cream
Balm
Oil
Water
QS
QS
Helianthus Annus (Sunflower) seed oil
QS
Carthamus Tinctorius (Safflower) seed oil
15.00
Simmondsia Chinensis (Jojoba) seed oil
5.00
Olea Europa (Olive) fruit oil
2.00
Tricaprylin
16.00
Sweet almond oil
4.00
Emulsifying wax NF
3.00
Cocos Nucifera (Coconut) oil
2.40
Caprylic/capric triglyceride
12.00
Caprylyl glycol/phenoxyethanol/hexylene
0.70
glycol
Myristyl myristate
5.00
Dicaprylyl maleate
2.50
Cetearyl alcohol/ceteareth-20
2.00
Stearic acid
2.00
Cetyl alcohol
1.60
1.80
Candelilla wax
0.05
Behenyl alcohol
1.60
PEG-100 stearate/glyceryl stearate
1.50
5.00
Potassium sorbate
0.10
Phenoxyethanol/cholorphenesin/glycerin/sorbic
1.40
acid
Bis-diglyceryl polyacyladipate-2
1.30
0.07
Butylene glycol
1.00
1.00
PEG-100 stearate
1.00
Glycine Soja (soybean) sterols
1.00
Yeast extract
1.00
Water/ Castanea Sativa (Chestnut) seed extract
1.00
Polysorbate 20
0.75
0.50
Mixture of Mandarin, Lavendar, Chamomile,
0.55
2.00
3.00
Sweet Almond Oil
Butyrospermum Parkii (Shea butter)
0.50
Glycerin
0.50
Ethylhexyl glycerin
0.30
Tocopheryl acetate
0.50
0.05
Trehalose
0.50
Alcohol/water/ Acmella Oleracea extract
0.50
Water/butylene glycol/ Calluna Vulgaris
0.50
(Heather) extract
Dimethicone
0.90
0.10
Potassium hydroxide
0.49
Carbomer
0.44
0.25
Sorbitol/water/ Ascophyllum Nodosum
0.25
extract/ Asparagopsis Armata extract
Linoleic acid
0.20
Cholesterol
0.20
Water/ Helianthus Annus (Sunflower) seed
0.20
extract
Wheat ( Triticum Vulgare ) Bran Extract/Olive
0.20
( Olea Europa ) extract
Hydrolyzed corn protein/hydrolyzed wheat
0.20
protein/hydrolyzed soy protein
Astrocaryum Murmuru seed butter
0.20
Phenoxyethanol
0.12
0.40
Disodium EDTA
0.10
0.10
Siegesbeckia Orientalis extract
0.10
Ionotus Obliquus (Mushroom) extract/cellulose
0.10
Water/lecithin/ Micrococcus lysate
0.10
Pantethine
0.10
Olea Europaea (Olive) leaf extract
0.10
Adenosine phosphate
0.06
Magnesium ascorbyl phosphate
0.05
Menyanthes Trifoliata leaf extract
0.05
Sorbic acid
0.05
Xanthan gum
0.04
0.02
Potassium hydroxide
0.25
Sodium hyaluronate
0.01
Phosphoric acid
0.0001
Cladosiphon Okamuranus extract/dextrin
0.01
Lady's Thistle ( Silybum Marianum ) fruit
0.001
extract
[0053] The products were made by combining the ingredients and mixing well.
Example 2
[0054] A body spray composition was made as follows:
[0000]
Ingredient
weight %
Water
QS
SD alcohol 40B
38.58
Laureth-4
4.00
Butylene glycol
3.8
Polysorbate 20
2.65
Mixture of Mandarin, Lavender and Chamomile oils
2.00
[0055] The composition was prepared by combining the ingredients and mixing well.
Example 3
[0056] The components of the Mixture (mandarin oil, lavender oil, chamomile oil and sweet almond oil) were tested for ability to reduce salivary cortisol concentration. It is known that reduced cortisol levels are associated with improved sleep. Salivary cortisol concentration is indicative of blood cortisol concentration with a reduced cortisol concentration being associated with improved relaxation.
[0057] The Mixture was tested on five panelists who were advised not to consume milk products at least one hour prior to the testing. Saliva samples were collected at 9 a.m. The Mixture (referred to as RT-3348 Mod 1F) was applied above the lip using a cotton applicator. After 15 minutes a second saliva sample was collected. The saliva samples were frozen at −80° C. Prior to performing the analysis, the frozen samples were thawed and centrifuged at 3000 rpm for 30 minutes. An enzyme immunoassay purchased from Salimetrics (Cortisol Salivary Assay Kit, salimetrics.com) was used to assay the saliva supernatant for the presence of cortisol according to the kit directions. The percentage difference in cortisol level between the pre- and post-exposure to the Mixture was calculated. The results of pre- and post-fragrance exposure are set forth in FIG. 1 . The percentage reduction in salivary cortisol as a result of exposure to the Mixture (RT-3348 Mod 1F) is as set forth in FIG. 2 .
[0058] While the invention has been described in connection with the preferred embodiment, it is not intended to limit the scope of the invention to the particular form set forth but, on the contrary, it is intended to cover such alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims. | A topical composition for inducing relaxation upon application to skin comprising a mixture of mandarin oil, lavender oil, chamomile oil, and optionally sweet almond oil; and a method for inducing sleep and/or a relaxation state by topically applying the composition. | 0 |
TECHNICAL FIELD OF THE INVENTION
[0001] This invention relates to liquid metal alloys for use in waste treatment processes and to waste storage products produced using liquid metal alloys. More particularly, the invention relates to liquid metal alloys for treating waste streams that include radioactive isotopes. The invention also encompasses a metal alloy storage product for use in storing radioactive isotopes.
BACKGROUND OF THE INVENTION
[0002] Many waste treatment processes utilize thermal energy to break up waste materials into their constituent elements or more desirable compounds. The use of thermal energy to break down materials is referred to generally as pyrolization. Molten or liquid phase metals have also been used to react with certain waste materials in order to produce more desirable compounds or reduce the waste to constituent elements. In particular, liquid aluminum has been used to react with halogenated hydrocarbons and produce aluminum salts. U.S. Pat. No. 4,469,661 to Shultz described the destruction of PCBs and other halogenated hydrocarbons by contacting the hydrocarbon vapor with liquid aluminum. The aluminum was contained in low-boiling eutectic mixtures of aluminum and zinc or aluminum, zinc, and magnesium. Shultz also suggested eutectic reactant mixtures containing iron, calcium, and other metals. U.S. Pat. No. 5,640,702 to Shultz disclosed a liquid metal treatment for wastes containing radioactive constituents. This patent to Shultz disclosed using lead in the liquid reactant metal as a chemically active material for reacting with non-radioactive constituents in the waste to be treated.
[0003] U.S. Pat. No. 5,000,101 to Wagner disclosed a process for treating hazardous waste material with liquid alkaline metal alloys. The liquid metal alloy comprised approximately 50% aluminum, 5% to 15% calcium, 5% to 15% copper, 5% to 15% iron, and 5% to 15% zinc. U.S. Patent No. 5,167,919 to Wagner disclosed a reactant alkaline metal alloy composition comprising between 40% to 95% aluminum, 1% to 25% iron, 1% to 25% calcium, 1% to 25% copper, and 1% to 25% zinc. The '919 Wagner patent also disclosed that magnesium could be substituted for calcium. In both of these Wagner patents, the waste material was reacted in the liquid alloy held at about 800 degrees Celsius.
[0004] In the process disclosed in the above-described Wagner patents, chlorine atoms in the waste material were stripped from the waste compound primarily by the highly reactive aluminum in the liquid reactant alloy. The aluminum and chlorine combined to form aluminum chloride. Carbon from the original waste compound was liberated either in elemental form or as char (CH, CH 2 , or CH 3 ). Both the aluminum chloride and liberated elemental carbon sublimed to a gaseous state at the 800 degree Celsius reaction temperature and were drawn off and separated.
[0005] Many hazardous waste sites have different types of wastes mixed together. The mixed waste may include numerous different types of halogenated hydrocarbons, other non-radioactive wastes, and radioactive isotopes. These mixed wastes which include radioactive and non-radioactive materials have proven particularly difficult to treat. Although, many non-radioactive wastes may be treated chemically and broken down into benign or less hazardous chemicals, radioactive constituents of the mixed waste stream cannot be manipulated to reduce or eliminate their radioactive emissions. It is desirable to separate the radioactive constituents from the other materials in the mixed waste and place the radioactive constituents in an arrangement for safe, long term storage.
[0006] Storing radioactive waste poses several problems in itself. For a radioactive isotope which has a long half life, a quantity of the material remains radioactive for many years. Thus, a storage arrangement for this long-lived radioactive waste must be capable of securely holding the waste for a very long period of time. However, radioactive emissions, particularly alpha radiation, can interact with the material of a container intended to store radioactive waste. This interaction can cause the container to degrade relatively quickly, long before the radioactive waste itself has degraded.
SUMMARY OF THE INVENTION
[0007] A liquid reactant metal alloy according to the invention includes at least one chemically active metal for reacting with non-radioactive material in a mixed waste stream being treated. The reactant alloy also includes at least one radiation absorbing metal. Radioactive isotopes in the waste stream alloy with, or disperse in, the chemically active and radiation absorbing metals such that the radiation absorbing metals are able to absorb a significant portion of the radioactive emissions associated with the isotopes. Non-radioactive constituents in the waste material are broken down into harmless and useful constituents, leaving the alloyed radioactive isotopes in the liquid reactant alloy. The reactant alloy may then be cooled to form one or more ingots in which the radioactive isotopes are effectively isolated and surrounded by the radiation absorbing metals. These ingots comprise the storage product according to the invention. The ingots may be encapsulated in one or more layers of radiation absorbing material and then stored.
[0008] The chemically active metal in the reactant alloy may comprise any metal capable of reacting chemically with one or more non-radioactive constituents in the waste stream. Preferred chemically active metals include magnesium, aluminum, lithium, zinc, calcium, and copper. In the preferred form of the invention, a combination of these metals is included in the reactant alloy. The particular chemically active metal or combination of chemically active metals used in a particular application will depend upon the makeup of the wastes in the waste stream and the reaction products which are desired from the treatment process. The relative amount or fraction of chemically active metal or combination of active metals in the alloy (the “chemically active fraction”) is preferably sufficient to both completely react the organic constituents and other reducible materials in the waste stream and help dissolve and disperse the radioactive isotopes in the remaining unreacted alloy. Preferably this chemically active metal fraction in the alloy and resulting storage product is no less than forty percent (40%) by weight of the reactant alloy.
[0009] Each radiation absorbing metal included in the reactant alloy is matched with a particular radioactive isotope to be alloyed with, or dissolved in, the metals in the liquid metal bath. That is, for each type of expected radioactive emission associated with a radioactive isotope to be alloyed, a radiation absorbing metal is included in the alloy for absorbing that particular type of emission. A particular radiation absorbing metal for absorbing a particular radioactive emission will be referred to herein as a corresponding radiation absorbing metal for that emission. Similarly, a particular radioactive emission which may be absorbed by a particular radiation absorbing metal will be referred to herein as a corresponding radioactive emission for that radiation absorbing metal. Preferred radiation absorbing metals include particular isotopes of lead, beryllium, cadmium, vanadium, yttrium, ytterbium, zirconium, and tungsten. One or more of these radiation absorbing metals may be used within the scope of the invention depending upon the radioactive isotopes to be added to the liquid metal bath. For purposes of this disclosure and the accompanying claims, a “radiation absorbing metal” comprises a metal which is capable of capturing a particular expected radioactive emission, that is, a particular emission at a natural decay energy level.
[0010] As used in this disclosure and the following claims, the “type of expected radioactive emission” associated with an isotope in the waste material to be treated refers to the particular type of both primary and secondary emission (alpha, beta, gamma, or neutron) characteristic of the isotope and any daughter isotope, and the characteristic energy level of each emission. The “expected radioactive emission” refers to each respective emission within each type of emission. For the purposes of this disclosure and the claims, a “primary radioactive emission” comprises the emission or emissions directly from the radioactive decay of an isotope. For most radioactive isotopes, the primary radioactive emissions will include either an alpha or beta emission at a characteristic energy level and a gamma emission at a characteristic energy level. A “secondary radioactive emission,” for the purposes of this disclosure, comprises a radioactive emission resulting from a primary radioactive emission. A secondary radioactive emission (commonly gamma radiation or a liberated neutron) is generated as a primary radioactive emission is absorbed by an absorbing material or as a primary radioactive emission otherwise interacts with matter.
[0011] Although the invention has particular application in treating mixed waste streams that include both radioactive and non-radioactive wastes, those skilled in the art will appreciate that a waste stream made up of only radioactive materials may be treated using the present process. The metal alloy according to the invention is useful for diluting and alloying or otherwise holding the radioactive isotopes for storage even in the absence of non-radioactive wastes.
[0012] Regardless of the particular composition of the reactant alloy according to the invention, the alloy is heated to a liquid state for receiving the waste stream. It is typically desirable to use the lowest reactant alloy temperature necessary to react any non-radioactive constituents in the waste stream and to efficiently melt or dissolve the radioactive material into the alloy. For mixed wastes that include organic constituents, a reactant alloy temperature of at least 770 degrees Celsius is generally required to quickly break the organic molecules down into the desired materials. Higher temperatures may be desirable to better dissolve or melt heavier radioactive isotopes such as transuranic elements.
[0013] The reactant alloy according to the invention may be heated using fossil fuel burners. Electrical induction heating systems or any other suitable heating arrangement may also be used to heat the reactant metal alloy to the desired operating temperature. The waste material is introduced directly into the liquid reactant alloy, preferably below the surface of the liquid material.
[0014] The aluminum, magnesium, or lithium in the reactant alloy chemically strips chlorine or any other halogen atoms from organic molecules in the waste material to form a metal salt. Some of these metal salts may remain in a liquid state and separate by gravity separation in the reactant alloy container. Other metal salts such as aluminum chloride, for example, along with carbon freed from the waste material in the form of elemental carbon and char go to a gaseous state at the temperature of the liquid alloy. Gas released in the treatment process may be drawn off and scrubbed in an aqueous scrubber/separator to produce a slurry of carbon, char, and salt solution. The salt solution may then be separated and processed to recover the salts, carbon, and char. Each material produced in a reaction with a chemically active metal in the alloy will be referred to in this disclosure as a reaction product.
[0015] In order to produce a mechanically stable ingot for long-term storage, the amount of radiation absorbing metal in the reactant alloy is maintained at a particular minimum ratio to the number of radioactive isotopes in the resulting alloy or as a function of the corresponding expected radioactive emissions in the volume of the resulting alloy. The preferred ratio comprises no less than approximately seven hundred and twenty-seven (727) atoms of radiation absorbing metal to the corresponding radioactive emission. This ratio produces an alloy in which radioactive emissions may be absorbed by the radiation absorbing metals without significantly degrading the mechanical integrity of the ingot.
[0016] One preferred form of reactant metal alloy according to the invention includes a compact crystal forming metal to help create a compact or close packed crystalline lattice structure in the resulting solidified storage product. A particularly desirable crystalline lattice structure in the resulting product comprises a hexagonal crystalline structure which may be produced with tungsten. The preferred relative amount or fraction of tungsten in the resulting storage product is one tungsten atom for every twenty-seven atoms of other elements in the storage product.
[0017] The alloy according to the invention may be adapted for producing a storage product for storing fast neutron emitting isotopes. To store fast neutron emitting isotopes, a reactant alloy should include a transmutation target fraction made up of a transmutation target material for absorbing fast neutrons emitted by the fast neutron emitting isotope. Because the absorption of a fast neutron will result in secondary radioactive emissions, the alloy should also include a transmutation emission absorbing fraction made up of a transmutation emission absorbing material for absorbing emissions resulting from the absorption of a respective fast neutron by the transmutation target material. The preferred close packed crystal structure produced by including tungsten in the alloy is particularly helpful in creating a structure in the resulting storage product for facilitating the absorption of fast neutrons emitted from constituents in the storage product.
[0018] One advantage of the treatment process according to the invention is that it combines the separation of radioactive waste from non-radioactive wastes with the chemical treatment of non-radioactive wastes. Also, the ingots which result from the process are very stable. There is very little chance for release of the alloyed or otherwise dispersed radioactive isotopes from the ingots. Furthermore, radioactive emissions from the ingots are reduced by the radiation absorbing metals which are distributed throughout the matrix of the alloy along with the radioactive isotopes. The radiation absorbing metals also serve to prevent the radioactive emissions from adversely affecting the other metals in the ingots and prevent significant mechanical degradation in the alloy material.
[0019] These and other advantages and features of the invention will be apparent from the following description of the preferred embodiments, considered along with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 is a block diagram showing a treatment process utilizing a reactant metal alloy embodying the principles of the invention.
[0021] FIG. 2 is a diagrammatic representation of an apparatus for performing the treatment process shown in FIG. 1 .
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0022] A reactant alkaline metal alloy composition embodying the principles of the invention includes one or more chemically active alkaline metals and one or more radiation absorbing metals. This combination of chemically active metals and radiation absorbing metals is used to treat wastes that include radioactive isotopes and produce a storage product for such radioactive isotopes. The alkaline metals make up a chemically active metal fraction in the alloy and resulting storage product and are included for chemically reacting with hydrocarbon and other non-radioactive wastes in a waste stream and for facilitating the alloying or dissolution of radioactive isotopes. Radiation absorbing metals generally do not react chemically in any substantial degree with any material in the waste stream and are included in the reactant alloy only for their radiation absorption characteristics. Also, the radiation absorbing metals are matched by their radiation absorption characteristics to radioactive isotopes to be added to the reactant alloy and, more particularly, to the radioactive emissions expected within the resulting alloy.
[0023] The chemically active alkaline metal or metals in the reactant alloy may comprise, aluminum, magnesium, lithium, calcium, iron, zinc, and copper. The aluminum, magnesium, and/or lithium in the reactant alloy react with halogenated hydrocarbons, to produce aluminum, magnesium, and/or lithium salts. Calcium, iron, zinc, and copper in the reactant alloy may react with certain non-radioactive constituents in the waste material, but are primarily included as stabilizing agents for the aluminum, magnesium, and/or lithium in the reactant alloy.
[0024] The radiation absorbing metal or metals in the reactant alloy may comprise particular isotopes of beryllium, cadmium, vanadium, yttrium, ytterbium, zirconium, tungsten, or lead. Various isotopes of these metals exhibit a low fission neutron cross section which allows them to absorb radioactive emissions to produce either a stable isotope or an isotope which emits only relatively low energy radiation. Table 1 shows a list of preferred radiation absorbing metals which may be employed in the reactant metal alloy within the scope of the invention. Table 1 also lists the particular radioactive emissions which each radiation absorbing metal is capable of absorbing. The particular radiation absorbing metal or metals chosen for an application will depend upon the nature of the radioactive isotopes in the waste stream being treated. Specifically, a radiation absorbing metal is included in the reactant alloy for each corresponding expected radioactive emission. Thus, for each type of expected radioactive emission associated with an isotope added to the alloy, an absorbing metal is included for absorbing that particular type of radioactive emission.
TABLE I ELEMENT ISOTOPE ABSORPTION CHARACTERISTIC LEAD 197-207 GAMMA ABSORBER AT .72 MeV AND HIGHER 208-214 BETA ABSORBER TUNGSTEN 173-183 GAMMA ABSORBER 186-189 BETA ABSORBER 184 BETA AT .429 MeV 185 GAMMA AT 0.075 MeV VANADIUM 46 BETA AT 6.03 MeV AND GAMMA AT .511 MeV 47 BETA AT 1.89 MeV AND GAMMA AT .511 MeV 48 BETA AT .696 MeV AND GAMMA AT .511 MeV 50 GAMMA AT .783 AND 1.55 MeV 52-54 BOTH BETA AND GAMMA AT CERTAIN ENERGY LEVELS YTTRIUM 82-96 BETA AT .008-3.06 MeV 89 GAMMA AT .91 MeV 90 GAMMA AT .202 MeV 91 GAMMA AT .551 AND .534 MeV 95 GAMMA AT 1.3 AND 1.8 MeV YTTERBIUM 154-164 ALPHA 162 BETA 175, 177 BETA 166-169, 171, GAMMA 176 CADMIUM 99-124 BETA ABSORBER, NEUTRONS AT 2,200 M/SEC BERYLLIUM 8 ALPHA ABSORBER 10-11 ALPHA AND BETA ABSORBER ZIRCONIUM ALL BETA ABSORBER AT 0.38 TO 0.65 MeV
[0025] Those skilled in the art will appreciate that many of the above-identified preferred radiation absorbing metals are themselves unstable isotopes and are subject to radioactive decay. However, the emission energies associated with these isotopes are sufficiently low to avoid substantial radiation leakage from the resulting storage product and mechanical degradation of the storage product.
[0026] The alloy produced according to the invention includes sufficient radiation absorbing metal for each corresponding expected emission to maintain a minimum ratio of radiation absorbing metal atoms to the respective corresponding expected radioactive emissions. The preferred ratio is no less than seven hundred and twenty-seven (727) atoms of radiation absorbing metal for each corresponding expected radioactive emission. Higher ratios may also be used within the scope of the invention. Lower ratios may also be used, albeit with an increased risk of radiation leakage from the resulting storage product.
[0027] As radioactive isotopes are alloyed into the reactant alloy, the atoms of radioactive material are incorporated into the matrix of the reactant alloy and isolated among the atoms of metals in the reactant alloy. Most importantly, the atoms of radioactive isotopes are substantially distributed and isolated among the atoms of corresponding radiation absorbing metal in the alloy. As used herein to describe the radioactive isotopes added to the liquid metal bath, the term “alloyed” means dissolved or otherwise dispersed and intimately mixed with the liquid reactant metal. This dispersion and resulting isolation of the radioactive isotopes in the reactant alloy matrix among the corresponding radiation absorbing metals at the desired minimum ratio helps ensure that most radioactive emissions from the radioactive isotopes will be captured within the reactant alloy storage product, thereby reducing overall radioactive emissions from the storage product. The specific absorbing metals absorb the radioactive emissions without substantially reducing the mechanical integrity of the storage product.
[0028] One preferred reactant metal alloy according to the invention additionally includes a fraction of material for producing a desirable crystalline structure in the storage product. This material comprises a compact crystal forming metal for producing a close packed crystalline structure in the resulting storage product. One preferred close packed crystalline structure comprises a hexagonal structure such as that produced by tungsten. Generally, one atom of tungsten will order 27 other atoms within its close packed hexagonal crystalline structure. The preferred concentration of tungsten in a storage product according to the invention is one atom for every 27 atoms of other metals in the storage product. Six of these groups comprising one tungsten atom and 27 other atoms combine to form a complete crystalline structure. Including less that one tungsten atom for every 27 other atoms in the storage product will result in some of the other atoms in the storage product being excluded from the desired close packed crystalline structure. However, the desired crystalline structure will be present for the 27 atoms ordered for the included tungsten atom. Providing the close packed crystalline structure throughout the resulting storage product has the effect of increasing the likelihood that a particular emission will be absorbed within the storage product. Thus, tungsten is preferably included in the reactant alloy in sufficient quantity to result in this one to twenty-seven ratio in the resulting storage product. The desired crystalline structure may allow fewer radiation absorbing metals to be included in the storage product and still provide effective absorption of emissions within the storage product.
[0029] It will be noted that tungsten may also serve as a radiation absorbing metal in the resulting storage product, depending upon the nature of emissions expected in the storage product. The ability to absorb certain radioactive emissions does not diminish or impact the compact crystal forming effect of tungsten in the resulting storage product.
[0030] The reactant alloy may include one or more of the following chemically active alkaline metals in the indicated concentration range: between about 1% to 25% zinc, between about 1% to 25% calcium, between about 1% to 25% copper, between about 1% to 25% magnesium, between about 1% to 25% lithium, and between about 10% to 90% aluminum. The reactant alloy may include one or more of the following radiation absorbing metals: lead, tungsten, beryllium, cadmium, vanadium, yttrium, ytterbium, and zirconium. Each of these radiation absorbing metals will commonly be present in the reactant alloy in a concentration range of between about 1% to 25% of the total alloy. All percentages used in this disclosure are by weight of the total reactant alloy. Table 2 sets out nine different preferred reactant alloys tailored for various waste streams. Each percentage in Table 2 refers to the percentage of a particular radiation absorbing isotope chosen from Table 1. Table 3 indicates the particular applications for which the alloys shown in Table 2 are tailored.
TABLE 2 I II III IV V VI VII VIII IX Zinc 3 2 5 — — — — 3 — Calcium 2 2 3 — — — — 2 — Copper 2 2 3 — — — — 2 — Magnesium 10 3 — — — — — 3 — Lead 42 — — 25 20 — 25 8 25 Aluminum 41 51 50 50 40 60 50 30 50 Lithium — — 4 — — — — 10 — Beryllium — 40 — 25 20 15 — 10 — Vanadium — — 35 — 20 10 25 10 13 Yttrium — — — — — 5 — 10 — Zirconium — — — — — 10 — 10 — Tungsten — — — — — — — 2 12
[0031] Reactant alloys III, VI, and VII are preferably used at an operating temperature of about 1000 degrees Celsius. Reactant alloy IV is preferably used in the process of the invention at an operating temperature of 850 degrees Celsius, while alloy V is used at an operating temperature of 900 degrees Celsius. The operating temperature for a particular treatment process according to the invention is chosen based both upon the constituents of the waste stream and the reaction products to be produced in the process. Higher operating temperatures may be required to break double and triple carbon bonds and other types of chemical bonds in the molecules of waste material being treated. Higher operating temperatures also generally allow the radioactive constituents in the waste stream to better dissolve or melt into the reactant metal alloy. Also, the operating temperature may be increased to allow certain reaction products to go to a gaseous state and then be removed from the reactant alloy container in the gaseous form.
TABLE 3 Alloy Waste Stream I Dioxins, organic compounds, gamma emitters II Chlorinated hydrocarbons, alpha emitters III Chlorinated hydrocarbons, beta emitters IV Halogenated hydrocarbons, gamma emitters, and alpha emitters V Halogenated hydrocarbons, alpha emitters, beta emitters, and gamma emitters VI Hydrocarbons, halogenated hydrocarbons, and multiple types radioactive isotopes VII Many mixed wastes, alpha emitters, and gamma emitters VIII Many mixed wastes including polychlorinated biphenyls, dioxins, PCP, battery mud, chrome plating salts, inks, solid rocket fuels, dyes, alpha emitters, beta emitters, and gamma emitters IX Mixed halogenated hydrocarbons, beta emitters, and gamma emitters
[0032] Another preferred reactant alloy according to the invention is tailored for processing waste streams containing relatively high gamma radiation emitting isotopes at 0.72 MeV and higher. This preferred alloy includes about 25% lead (197-207), about 25% tungsten (173-183), and about 50% chemically active metal. The chemically active metal may comprise aluminum and/or magnesium.
[0033] As indicated by the example reactant metal alloys shown in Tables 2 and 3 and discussed above, the amount of chemically reactive metal in the alloy preferably always makes up approximately 40% or more of the alloy by weight. This level of chemically active metal in the reactant alloy is helpful in dissolving the metal radioactive constituents in the waste stream. The dissolved radioactive constituents may then be dispersed freely throughout the liquid metal to produce the desired storage alloy.
[0034] The radioactive material storage product according to the invention comprises one or more chemically active metals and one or more radioactive isotopes. Also, for each type of expected radioactive emission in the volume of the storage product, the product further includes a corresponding radiation absorbing metal adapted to absorb the respective radioactive emission. The corresponding radiation absorbing metal may be adapted to absorb radioactive emissions from different isotopes, and thus the storage product will not always include a separate radiation absorbing metal for each isotope. Rather, one radiation absorbing metal may be capable of absorbing two or more types (that is, type and energy level) of radioactive emissions in the storage product. In any event, the storage product preferably includes at least about 727 atoms of radiation absorbing metal for each corresponding expected radioactive emission.
[0035] In another aspect of the invention, the reactant metal alloy and resulting storage product includes materials specifically suited for absorbing fast neutrons that may be emitted from isotopes in the storage product. Fast neutrons, neutrons emitted at an energy level of ten MeV or greater, may be absorbed by certain materials. These fast neutron absorbing materials transmutate upon absorption of the fast neutron to produce a different isotope. This transmutated material will generally decay with additional radioactive emissions. According to the invention, where the reactant metal alloy will receive fast neutron emitters, such as materials from spent nuclear fuel rods, the reactant alloy will include a transmutation target fraction made up of transmutation target material for absorbing fast neutrons emitted by the fast neutron emitting isotope. The reactant metal alloy will also include a transmutation emission absorbing fraction made up of transmutation emission absorbing material for absorbing emissions resulting from the absorption of a fast neutron by the transmutation target material. These resulting emissions are all emissions occurring after the initial transmutating absorption and may be emissions occurring in several steps.
[0036] Transmutation target material and the fraction of such material in the alloy and resulting storage product may include appropriate isotopes of boron, beryllium, lithium, magnesium, aluminum, sodium, zinc, and cadmium. The transmutation emission absorbing fraction in the alloy and resulting storage product may be made up of isotopes of boron, cadmium, and gold.
[0037] The transmutation contemplated in the storage product according to the invention follows the following emission steps: Transmutation Target (Target)+fast neutron (N F )=new nucleus+atomic particles of low atomic weight (hydrogen nuclei (H 2 or H 1 ), α, γ)+lowered kinetic energy. The transmutation emission absorbing materials (Trans/Ab) then absorb the atomic particles and in turn emit lower energy particles including slow neutrons (N S , less than 10 MeV).
N F +Target→New Nucleus+(H 2 , α, H 1 , γ)
H 2 +Trans/Ab→H 1 , N S , α
α+Trans/Ab→H 1 , N S
γ+Trans/Ab→N S
It will be noted that some materials may serve both as transmutation targets and transmutation emission absorbing materials.
[0038] In the preferred form of the invention, the transmutation target fraction in the storage product includes no less than approximately three hundred and sixty-five (365) atoms of transmutation target material for each atom of fast neutron emitting isotope in the storage product. Also, the transmutation emission absorbing fraction in the storage product includes no less than approximately three hundred and sixty-five (365) atoms of transmutation emission absorbing material for each atom of fast neutron emitting isotope in the storage product. These relative amounts of transmutation target material and transmutation emission absorbing material provide the preferred coverage around each fast neutron emitting atom in the storage product to increase the likelihood that the fast neutron emission will be absorbed within the primary crystalline matrix within which the fast neutron emitter is contained.
[0039] With each reactant metal alloy composition according to the invention, the alloy is heated to a liquid state to prepare the material for receiving the waste stream. Typically, the temperature of the liquid alloy must be maintained at no less than 770 degrees Celsius in order to provide the desired reaction with organic molecules in the waste material. Higher temperatures for the liquid alloy may also be used within the scope of the invention as discussed above with reference to Table 3. Lower temperatures may also be used where relatively few non-radioactive constituents are included in the waste stream or only relatively light hydrocarbons are included in the waste. In any event, the operating temperature should be a temperature sufficient to place the particular reactant metal alloy in a liquid state and sufficient to allow the radioactive metals in the waste material to dissolve or melt into the bath.
[0040] The reactant metal alloy treatment process according to the invention may be used to treat many types of radioactive waste materials and mixed waste streams including both radioactive waste and non-radioactive waste. The treatment process is particularly well adapted for treating wastes which include radioactive constituents mixed with halogenated hydrocarbons. The radioactive isotopes may comprise any isotopes which may be alloyed into the particular liquid reactant metal including, for example, isotopes of plutonium, radium, and rhodium.
[0041] Certain radioactive isotopes may not alloy into the liquid reactant metal. Where these isotopes react with metals in the bath to form reaction products which remain in solid or liquid form, these reaction products may be thoroughly mixed with the liquid reactant metal and then cooled while mixed to produce relatively low emission ingots. Any gaseous reaction products which include radioactive isotopes will be entrained with the non-radioactive gaseous reaction products. Some gaseous radioactive isotopes may be absorbed from the reaction product gas. For example, tritium may be absorbed by palladium placed in the stream of gaseous reaction products. However, it is desirable to maintain the operating temperature of the liquid reactant metal low enough to reduce the amount of radioactive isotopes which go into gaseous reaction products. For example, where a radioactive isotope of iodine is included in the waste stream, the chemically active metal in the alloy may include aluminum and the operating temperature is maintained low enough to ensure that the resulting aluminum iodide remains primarily in a liquid state.
[0042] The aluminum, magnesium, or lithium in the reactant alloy according to the invention strips halogens from the halogenated hydrocarbons in the waste stream to produce halogen salts. Other elements in the non-radioactive waste material, such as phosphorous, sulphur, and nitrogen, are also stripped from the carbon atoms in the waste material. Much of this other stripped material forms metal salts (sulfates, nitrates, phosphates) which separate from the liquid reactant metal by their respective density. Where these separated materials include only non-radioactive constituents they may be separately drawn or scraped from the liquid reactant metal by any suitable means. Most of the halogen salts and char go to a gaseous state and are drawn off for separation and recovery. Any low boiling point metals, such as arsenic or mercury, for example, which are liberated from the waste materials are also drawn off in a gaseous state for recovery. Non-radioactive, relatively high boiling point metals such as chromium, and radioactive metals in the waste material remain safely in the liquid alloy. The original metals which make up the alloy remain in the liquid alloy unless consumed in the formation of salts and small quantities of oxides.
[0043] The treatment process according to the invention is illustrated in FIG. 1 . The waste material to be treated is first analyzed to identify the types and concentrations of non-radioactive chemicals and radioactive isotopes present in the waste. This analysis step is shown at dashed box 101 in FIG. 1 . Information regarding the types and concentrations of non-radioactive constituents in the waste material is used to help choose the types of chemically active metals to be included in the liquid reactant alloy. Information regarding the radioactive isotopes in the waste material determines the amount and type of radiation absorbing metals to be included in the liquid reactant alloy.
[0044] The types and concentrations of radioactive isotopes and non-radioactive chemicals in the waste material are preferably determined using an analytical technique such as mass spectroscopy at step 101 . Of course, any analytical technique will be limited to certain minimum detection levels below which an isotope or chemical cannot be detected. The concentration of radioactive isotopes detected in the waste stream is then used at step 103 to produce an estimate of the quantity or amount of each radioactive isotope present in the waste per unit volume or weight.
[0045] Once the amount and type of non-radioactive constituents and radioactive isotopes in the waste material are known, the reactant metal alloy for treating a selected volume or weight of the particular waste material is constructed at step 104 . Specifically, a reactant metal alloy is built with chemically active metals for reacting with the non-radioactive constituents in the waste material and with sufficient radiation absorbing metals to produce the desired storage product.
[0046] With the reactant alloy built for the particular waste and held in a liquid state at the desired operating temperature, the process includes metering the waste material into the liquid reactant metal at step 105 . Any suitable metering device may be used to perform the metering step according to the invention. Preferably, the metering device provides a continuous output of volumetric information (or weight information if it is desired to meter the waste stream by weight). Since the amount of waste material which may be added to the liquid reactant alloy to produce the desired storage product (desired minimum ratio) is known, waste material may be metered into the reactant alloy until that known amount is reached. Alternatively, the continuous output showing the cumulative amount of waste added to the reactant alloy may be used at step 106 to calculate the total radioactive isotopes in the alloy and the ratio of radiation absorbing atoms to corresponding expected radioactive emissions at step 106 . This calculation step also requires the radioactive isotope concentration or amount information from step 103 and the alloy information from step 104 . The calculation may be performed using a suitable processor (not shown) connected to receive the required inputs, or may be performed manually. The calculated ratio or the cumulative amount may be compared to a corresponding set value at step 107 to provide a control signal which may be used to automatically stop the introduction of waste material into the reactant alloy.
[0047] The metered amount of waste material is added to the liquid reactant metal at step 108 in FIG. 1 . Also, the preferred form of the invention includes a separate emission monitoring step to monitor radioactive emissions from the waste material stream as it is being directed to the liquid reactant alloy. This separate monitoring step, 108 in FIG. 1 , may be performed using any suitable radioactive emission detector to detect anomalous high concentrations of radioactive isotopes. Suitable devices include gas-filled, scintillation, or semiconductor type detectors. Regardless of the detector type, an unexpected spike in radioactive emissions may be used at decision box 109 to produce a control signal to stop the waste stream from being introduced into the reactant alloy. This control signal may be automated or may be made manually by an operator overseeing the treatment process.
[0048] In the preferred treatment process according to the invention, the reactant metal alloy composition is contained in a reactant alloy container such that the alloy is substantially isolated from oxygen. The reactant alloy is then heated by a suitable heating arrangement to the desired operating temperature, which is generally greater than 770 degrees Celsius as discussed above. Any remaining oxygen in the reactor vessel quickly reacts with the metal in the alloy to produce metal oxides which appear as dross at the surface of the liquid material or sink to the bottom of the reactant alloy container. In the preferred process, a layer of pure carbon in the form of graphite is placed at the surface of the liquid reactant metal alloy. The graphite layer may be from approximately one-quarter inch to several inches thick and helps further isolate the liquid alloy from any oxygen which may be in the reactant alloy container.
[0049] Once the liquid alloy reaches the desired operating temperature, the waste material is introduced into the reactant liquid alloy to perform the contacting step shown in FIG. 1 . The waste material is preferably introduced below the surface of the liquid alloy but may be introduced at the surface of the alloy within the scope of the invention. The temperature of the metal alloy is maintained at least at the desired operating temperature as waste material is added to the liquid alloy. Heat will commonly need to be added continuously by the heating arrangement in order to maintain the desired operating temperature. Also, it will be appreciated that pockets of relatively cooler areas may form momentarily in the reactant alloy as waste material is added. The bulk of the reactant alloy, however, is maintained at least at the desired operating temperature. A suitable mixing arrangement may be used with the reactant alloy container to ensure that the relatively cool waste material is distributed quickly within the reactant alloy and to ensure that the radioactive isotopes and radiation absorbing metals are evenly distributed within the alloy. A mechanical stirring device (not shown) to continuously stir the liquid material provides a suitable mixing arrangement.
[0050] Once the desired minimum level of radiation absorbing metal to corresponding expected radioactive emissions is reached for a given volume of reactant alloy according to the invention, the waste stream is halted and the reactant alloy cooled to form one or more solid ingots of the storage material. Where isotopes of cadmium are to be included in the storage product, it is necessary to cool the liquid metal to a temperature low enough to allow the cadmium to go to a liquid form (725 to 765 degrees Celsius). Thereafter, the liquid material may be thoroughly mixed prior to further cooling. The resulting solid ingots each include unreacted alkaline metals, the radiation absorbing metals, and the radioactive isotopes from the waste stream, all substantially evenly distributed. Each ingot is preferably encapsulated with a radiation absorbing encapsulant material for storage. The encapsulant material preferably includes a material or combination of materials which together are capable of absorbing each type of radioactive emission expected from the resulting ingot. Also, the encapsulant material preferably includes a close packed crystal forming metal such as tungsten to produce a desirable crystalline structure in the encapsulant material which holds the emission absorbing metals closely and thereby increase the likelihood that a given emission from the storage product will be absorbed in the encapsulant material and will not penetrate the encapsulant material. The preferred tungsten concentration in the encapsulant material is one tungsten atom for each 27 other atoms in the encapsulant material.
[0051] FIG. 2 shows an apparatus for performing a treatment process embodying the principles of the invention. The apparatus includes a reactant alloy container 202 , a recovery/recirculation arrangement 240 , a feed arrangement 241 , and a heating arrangement 242 . The reactant alloy container 202 is preferably built from a suitable metal which will maintain structural integrity at the desired elevated temperatures. However, due to the highly reactive nature of the alloy 210 , the reactant alloy container 202 is lined with a ceramic or other suitable refractory material to prevent the metal of the container from reacting with the reactant alloy. Also, due to the radioactive material to be alloyed in the process, container 202 also preferably includes a layer S of suitable radiation absorbing shielding. This shielding is adapted to block or absorb each type of radioactive emission which may emanate from the interior of container 202 . A cover 203 is connected over container 202 for collecting gaseous reaction products and helping to isolate the metal bath from oxygen. Although not shown in the drawing, radiation shielding material is also preferably included in cover 203 and with the feed arrangement 241 .
[0052] An expendable hook 205 may be placed in the alloy 210 at the termination of the process and, after cooling, may be used to lift the solidified alloy ingot from the reactant alloy container 202 . Alternatively, a suitable drain may be included in container 202 for draining off reactant alloy once the desired minimum ratio of radiation absorbing atoms to corresponding radioactive emissions is reached.
[0053] Solids may be mixed with liquids to form a slurry and the slurry introduced similarly to liquid wastes as discussed below. Also, solids either alone or in the form of a slurry may be introduced into the container 202 through an auger arrangement or other suitable arrangement such as that shown in U.S. Pat. No. 5,431,113, the disclosure of which is hereby incorporated herein by this reference.
[0054] The heating arrangement 242 includes an induction heater, including an induction heater power supply 206 and induction coils 204 built into the reactant alloy container 202 . The coils 204 may be water-cooled and the water may be used to cool the reactant alloy 210 as desired, either during the treatment process or at the completion of the treatment process. The induction heater arrangement 242 includes a heater control 209 with a suitable sensor 209 a inside the reactant alloy container 202 for controlling the induction heater and maintaining the temperature of the metal alloy 210 at the desired operating temperature. Although the induction heating arrangement is illustrated in FIG. 1 , any suitable heating arrangement, including a fossil fuel burning heater may be used to heat the alloy 210 to the desired temperature. U.S. Pat. No. 5,452,671 to the present inventor illustrates a fossil fuel fired heating arrangement which may be used according to the present invention. The disclosure of U.S. Pat. No. 5,452,671 is hereby incorporated herein by this reference.
[0055] The feed arrangement 241 includes feed tank 212 and feed coil 208 . Feed tank 212 contains waste material to be processed. A feed pump 214 pumps the waste material from feed tank 212 to the reactant alloy container 202 through a metering device 215 . Metering device 215 serves two functions. First, metering device 215 is operated to meter waste material into the reactant alloy at a rate which does not exceed the capacity of the heater arrangement 242 to maintain the desired operating temperature in the liquid reactant metal 210 . Second, metering device 215 provides information regarding the amount of waste material added to the liquid reactant metal. This quantity information may be used to calculate the ratio of radiation absorbing atoms in the alloy 210 to the atoms of corresponding expected radioactive emissions. As described above with reference to FIG. 1 , the ratio calculations are preferably computed automatically and continuously in a suitable control processor shown at reference number 243 in FIG. 2 . Control processor 243 also receives information concerning the radiation absorbing metals in container 202 and information concerning the concentration (or amount) of various radioactive isotopes in the waste material to be treated. Alternatively to calculating the ratio as waste material is being added to the liquid metal bath, the quantity information used to build the liquid reactant alloy can be used to limit the amount of waste material metered through metering device 215 .
[0056] Feed system 241 also preferably includes a radioactive emission monitoring device 244 connected in position to monitor the stream of waste material being directed to the liquid metal 210 for treatment. Monitoring device 244 may be located in a recirculation manifold shown generally at 245 . Should monitoring device 244 detect a spike in radioactive emissions from the waste stream, controller 243 (or an operator) may close valve 245 a and open valve 245 b to circulate the waste stream back to feed tank 212 . Alternatively to the manifold arrangement, the feed pump 214 can simply be turned off to halt the flow of waste material into the reactant alloy 210 .
[0057] Feed coil 208 is coated on its interior and exterior surfaces or formed from a ceramic or other suitable refractory material to prevent the coil from reacting with the liquid alloy 210 in container 202 . The outlet end of the coil is preferably positioned well below the surface of the alloy 210 to ensure good contact between the waste material and liquid reactant metal 202 . The feed system 241 also preferably includes a gas purging arrangement including a gas storage cylinder 216 for containing a suitable purge gas such as nitrogen. The gas purging arrangement is operated to purge the feed lines and coil 208 of air prior to operation of the system. Gases other than nitrogen may be used to purge the system of oxygen, including flue gases from a fossil fuel burning heater arrangement.
[0058] The recovery/recirculation system 240 includes an aqueous scrubber/separator 224 , a char/water separator 230 , a salt recovery arrangement 231 , and a recirculation arrangement 232 . Off-gas from the area above the liquid alloy 210 in container 202 comprising gaseous halogen salts, char, and other gases are drawn off through line 218 . Line 218 is preferably made of stainless steel and includes a relief valve 220 to maintain atmospheric pressure on line 218 . A water spray nozzle 222 is associated with the scrubber/separator 224 and serves to spray water into the off-gas at the inlet to the scrubber/cyclone separator. The water sprayed into the off-gas causes the char to coalesce while the salt in the off-gas goes into the solution in the water. The amount of water supplied through nozzle 222 is preferably controlled with temperature controller 223 to maintain the temperature below about 100 degrees Celsius in the scrubber/separator 224 . A char slurry forms in the bottom of the scrubber/separator 224 and is drawn off through valve 226 . The slurry comprises char and water with salt in solution. The char slurry is directed to char/water separator 230 which separates out the fine char particles from the water solution and passes the water solution through pump 233 on to salt recovery system 231 . Salt recovery system 231 may comprise an evaporative system. Water from salt recovery system 231 may be recycled to nozzle 222 . Any gas from separator/scrubber 224 may be vented to the atmosphere through a suitable radiation monitoring arrangement (not shown). Alternatively, gas from separator/scrubber 224 may be drawn off through recirculation fan 228 and reintroduced to the area above the liquid alloy 210 for recycling through the system.
[0059] It will be appreciated that a reactant metal alloy according to the invention may be used in other types of apparatus to produce the desired storage product. The invention is not limited to the illustrated apparatus. For example, an apparatus such as that shown in U.S. patent Ser. No. 10/014,976, entitled “MOLTEN METAL REACTOR UTILIZING MOLTEN METAL FLOW FOR FEED MATERIAL AND REACTION PRODUCT ENTRAPMENT” may be used with an alloy according to the invention to produce the desired storage product. The entire content of this application to the present inventor is incorporated herein by this reference.
EXAMPLE I
[0060] A waste material is analyzed with a mass spectrometer and found to comprise thorium 229 at 9 parts per million (ppm), PCBs at 500 ppm, and creosote at 1000 ppm in water. To treat one ton of the waste material, a liquid reactant metal according to the invention may include predominantly aluminum and perhaps small percentages of zinc, iron, copper, and calcium. The primary emissions of thorium 229 include alpha particles at 5.168 MeV. Beryllium 11 is added to the liquid reactant metal as a corresponding absorber for the alpha emissions and lead 206 is added to absorb the primary gamma emissions from the thorium 229 and secondary gamma emissions as the alpha particles interact with materials in the bath. The 9 ppm of thorium 229 equates to 6.412 grams of the isotope per ton of the waste material. 6.42 kilograms of beryllium 11 is included in the metal bath to provide a one thousand to one correspondence between the beryllium and the expected alpha emissions. 12.84 kilograms of lead 206 is included in the metal bath to provide a one thousand to one correspondence between the lead and the expected primary and secondary gamma emissions.
[0061] The above described preferred embodiments are intended to illustrate the principles of the invention, but not to limit the scope of the invention. Various other embodiments and modifications to these preferred embodiments may be made by those skilled in the art without departing from the scope of the following claims. For example, although the invention is described above with the reactant alloy being heated to a liquid state in the reactant alloy container, the alloy constituents may be heated to a liquid state together or individually outside the reactant alloy container and added to the container as a liquid material. Heating the reactant alloy metals outside of the reactant alloy container is to be considered an equivalent to the embodiment in which the metals are initially heated to the liquid state within the reactant alloy container. Furthermore, constituents of the desired reactant metal alloy may be added while the waste material is being added. Adjusting the reactant alloy of the bath after some waste material has been added is to be considered equivalent to adding the waste material to a completely pre-built reactant metal bath. Also, numerous solid and liquid recovery arrangements may be used within the scope of the invention instead of the example arrangement 240 shown in FIG. 2 and the arrangement shown in application Ser. No. 10/014,976. | A liquid reactant metal alloy ( 210 ) includes at least one chemically active metal for reacting with non-radioactive material in a mixed waste stream being treated. The reactant alloy ( 210 ) also includes at least one radiation absorbing metal. Radioactive isotopes in the waste stream alloy with, or disperse in, the chemically active and radiation absorbing metals such that the radiation absorbing metals are able to absorb a significant portion of the radioactive emissions associated with the isotopes. Non-radioactive constituents in the waste material are broken down into harmless and useful constituents, leaving the alloyed radioactive isotopes in the liquid reactant alloy. The reactant alloy may then be cooled to form one or more ingots in which the radioactive isotopes are effectively isolated and surrounded by the radiation absorbing metals. These ingots comprise storage products for the radioactive isotopes. The ingots may be encapsulated in one or more layers of radiation absorbing material and then stored. | 2 |
This application claims a benefit of 60/253,833 filed on Nov. 29, 2000.
FIELD OF THE INVENTION
This invention relates to reflective and transmissive liquid crystal displays, to electrophoretic displays and to Organic Light Emitting Diode (OLED) displays and more particularly, to an array of pixels where each pixel exists as three color cells stacked above one another driven by an array of thin film transistors positioned below the stacked color cells.
BACKGROUND OF THE INVENTION
In a typical liquid crystal (LC) display the three color cells: Red, Green and Blue (RGB) are placed side by side with respect to each other and are covered by a polarizer. The RGB color filter in LC displays use almost one third (⅓) of the incident light. To achieve high brightness and resolution the LC display requires back lighting. The back lighting consumes a considerable amount of energy and rapidly drains the battery of a portable device. The reflected ambient light display with individual color cells stacked on top of each other is capable of much higher pixel density per square inch than a conventional LC display. Thus, in principle, the pixel density per unit area could be much higher than what it is for the LC horizontally placed color cell pixel display and the energy and cost of operating such a display would be much smaller.
Many attempts were made to build a three level, three color reflective display. In such a display the pixels have to be placed (stacked) on top of each other rather than side by side as is the case in a typical LC display. In U.S. Pat. No. 5,796,447 which issued Aug. 18, 1998 to Okumura et al., a liquid crystal display is described having each pixel formed by a plurality of liquid crystal layers and a plurality of transparent electrodes which are alternately stacked on a first electode functioning as a reflecting plate to display a plurality of different colors.
The most difficult part in building such a vertically stacked color cell reflective display is providing the vertical electrical connections between the electrodes at individual levels in each pixel and the respective TFT on the substrate below.
SUMMARY OF THE INVENTION
In accordance with the present invention, a structure and fabrication technology for a reflective, ambient light, low cost display is described comprising a plurality of pixels laid out side by side with stacked color cells such as three levels on top of each other forming a pixel. Each stack of three color cells being driven by an array of TFT's positioned on the bottom layer. Each pixel comprises a light transmitting front dielectric window, three levels of individual cells RGB (Red, Green, and Blue) stacked on top of each other, each level having its own individual electrode, each electrode being connected by a vertical electrode running through another cell and having sealed conducting via holes running through each transparent dielectric window and being connected to an individual TFT. The bottom panel having a reflective surface so as to provide maximum reflectivity of the ambient light. Placed under the reflective surface is an array of TFT's which provide the electrical impulses necessary to set each individual potential in each vertically stacked cell with respect to a ground potential. A transmissive liquid crystal display can readily be fabricated by deleting the reflective surface.
The invention further provides a cell with electrode configurations for either electrophoretic material, liquid crystal material or Organic Light Emitting Diode (OLED) display.
The invention further provides structures and assembly methods suitable for fabricating a Guest-Host LCD, a Cholesteric LCD, a Holographic Polymer Dispersed LCD and an Organic Light Emitting Diode (OLED) display.
BRIEF DESCRIPTION OF THE DRAWING
These and other features, objects, and advantages of the present invention will become apparent upon consideration of the following detailed description of the invention when read in conjunction with the drawing in which:
FIG. 1 is a schematic top view of a first embodiment of the invention of the first color cell.
FIG. 1A is a cross section view along the line 1 A— 1 A of FIG. 1 .
FIG. 1B is a schematic top view of a first embodiment of the invention of the second stacked color cell.
FIG. 1C is a schematic top view of a first embodiment of the invention of the third stacked color cell.
FIG. 1D is a schematic top view of a first embodiment of the invention of the top cover of the cell.
FIG. 2 is a schematic cross section view of second embodiment of the invention.
FIG. 3 is a schematic cross section view of a third embodiment of the invention.
FIG. 4A is a schematic cross section view of a vertical connection.
FIG. 4B is a schematic cross section view of the electrodes associated with a one layer electrophoretic display.
FIGS. 5A-5F show schematic cross section views illustrating the process steps in forming a display.
FIGS. 6A-6C show schematic cross section views illustrating three ways for forming vias.
FIG. 7A shows a schematic cross section view of a step in forming a display.
FIG. 7B shows a top view of FIG. 7 A.
FIG. 8 shows a schematic and block diagram showing the steps for forming individual layers of a display and assembly of the layers into a display.
FIG. 9 shows a block diagram for an alternate method of assembling layers into a display.
FIG. 10A shows a schematic cross section view illustrating the fabrication of the ITO electrode in a Guest-Host liquid crystal display.
FIG. 10B shows a schematic cross section view illustrating the vertical electrode and ITO in a liquid crystal display.
FIG. 10C shows a schematic cross section view illustrating the step of applying a polyimide coat over the ITO in a liquid crystal display.
FIG. 10D shows a schematic cross section view illustrating the preparation for joining layers at the vias in a liquid crystal display.
FIG. 10E shows a schematic top view illustrating the ITO in the first level in a liquid crystal display.
FIG. 10F shows a schematic cross section view of the three levels in a liquid crystal display; and
FIG. 10G shows the desired spectral response from the three cell stacked pixel in operation.
FIG. 11 is a schematic cross sectional view of a one layer Organic Light Emitting Diode (OLED) display.
FIG. 12 is a schematic cross sectional view of a three layer Organic Light Emitting Diode (OLED) display.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention describes several different three level embodiments for a color reflective display and the processes and techniques to fabricate such structures. One such embodiment is shown in FIGS. 1 , 1 A- 1 D. FIGS. 1 , 1 B, 1 C and 1 D show a cross section top view of FIG. 1A of electrodes in a stacked electrophoretic reflective display 10 . Electrophoretic reflective display 10 has stacked cells 12 - 20 which may have the same internal structure. Stacked cells 13 - 20 surround and are adjacent to stacked cell 12 . FIG. 1A shows a cross section view along the line 1 A— 1 A of FIG. 1 . FIG. 1 shows a cross section view along the line 1 — 1 of FIG. 1 A. FIG. 1B shows a cross section view along the line 1 B— 1 B of FIG. 1 A. FIG. 1C shows a cross section view along the line 1 C— 1 C of FIG. 1 A. FIG. 1D shows a cross section view along the line 1 D— 1 D of FIG. 1 A.
FIG. 1A shows electrodes 22 - 24 for respective electrophoretic layers 26 - 28 . Electrophoretic layers 26 and 27 are separated by glass spacer 30 . Electrophoretic layers 27 and 28 are separated by glass spacer 31 . Cover glass 32 is above electrophoretic layer 28 . A wall electrode 34 extends vertically between glass spacer 33 and cover glass 32 and follows path to define the exterior of stacked cell 12 . Wall electrode 34 is usually at ground potential surrounds at a distance from electrodes 22 - 24 . A glass spacer 33 is below electrophoretic layer 26 . Vertical electrodes 38 - 40 function to connect a potential to electrodes 22 - 24 to place an electric field between the respective electrode and wall electrode 34 . The potential for electrodes 22 - 24 determine the color of the cell when viewed. The potential is generated by thin film transistors positioned (not shown) below glass spacer 33 . Electrodes 39 and 40 are insulated from electrode 22 by for example a glass insulator.
FIGS. 1 , 1 B and 1 C show openings 44 and 45 in wall electrode 34 to permit filling of the spaces between glass spacers 31 - 33 and cover glass 32 with electrophoretic material forming electrophoretic layers 26 - 28 .
A second embodiment of the invention is shown in FIG. 2 . FIG. 2 shows a Guest-Host Liquid Crystal (LC) reflective or transmisive display 50 . Reflective display 50 consists of a bottom layer 52 which carries the Thin Film Transistors (TFT's) (not shown). These transistors are fabricated by conventional means. The TFT bearing bottom layer has a dielectric insulator layer 54 on it. The dielectric insulator 54 has vias 56 - 58 which are filled with metal. Each metal via 56 - 58 is contacting a respective transistor which controls the potential on a respective level of the pixel. The metal is selected from the group of conductors such as Cu, Ni, Mo, Ag, Au, etc. The bottom layer 52 bearing the TFT's, the dielectric layer 54 and the metal filled vias 56 - 58 is planarized by a suitable means such as mechanical or chemical mechanical polishing (CMP).
In addition to the Guest-Host Liquid Crystal display described above, cholesteric LC reflective display and Holographic Polymer Dispersed LC (H-PDLC) reflective display may be fabricated. In cholesteric LC mode, each LC reflects the corresponding wavelength of incoming light (R, G, B) according to the rotating pitch of LC and fall color is achieved by additional color mixing. Black is presented by placing an absorbing layer at the bottom.
In H-PDLC mode, each H-PDLC layer consists of electrically controllable hologram, where a polymer and liquid crystal mixture has a layered structure showing wavelength dependent reflection characteristics, which is formed by using interference exposure of two laser beams known as the exposure method of volume holograms, and shows electrically controllable reflectivity change, In this H-PDLC scheme, there is a small reflection at each interface between the polymer and LC layer when the incident light beam sees a refractive index difference between these two layers; and no reflection when no index difference is observed by the light beam, where the observed refractive index of the LC is controlled by the applied electric field. Then, each H-PDLC reflects the corresponding wavelength of incoming light. Black is presented by placing an absorbing layer at the bottom.
In electrophoretic display 10 shown in FIGS. 1 and 1 A- 1 D the planarized dielectric 32 with metal filled vias 38 - 40 is metallized by sputtering or evaporation or any other suitable means by an adhesion metal and a plating seed layer metal. Subsequently, a 5 to 15 micrometer thick Novolak positive working resist is applied by spinning, spraying, doctor blading or any other conventional means. After the usual prebake cycle, a pattern such as shown in FIG. 1 is exposed through a photo resist mask and developed. The pattern shown in FIG. 1 is electroplated using a conventional acid copper solution until the metal slightly “mushrooms” overhangs over the photo resist (not shown). Glass spacer 33 with the photo resist and the copper vias 38 - 40 imbedded in it is planarized by mechanical or Chemical Mechanical Polishing (CMP) process. The resist and the seed and adhesion layers are removed after the step of planarization.
Epoxy based photo sensitive dielectric such as commercially available SU 8 or poly methyl methacrylate (PMMA) resist is applied and a pattern exposed leaving the edges (sidewalls) of copper vias 38 - 40 and wall electrode 34 overcoated with a very thin layer of dielectric to provide electrical insulation. In electrophoretic display 10 , the metal vias 38 - 40 has to be covered by a thin dielectric to prevent discharge of the electrophoretic particles as they come in contact with electrode 22 - 24 during the collection process. If it is desired to have a very white reflective surface prior to application of SU 8 , the copper walls of wall electrode 34 and electrodes 22 - 24 may be immersion or exchange plating with Sn or Ag.
The thin layer of SU 8 or PMMA remaining on top of copper electrode 22 is removed by a suitable means from the top of the patterns until the copper of electrode 22 is exposed. The exposed copper of electrode 22 is then terminated or covered by a thin layer of electroless Co(P), CoW(P), or CoSn(P) and is topped by a thin layer of immersion gold formed by the step of immersion plating for subsequent easy solderability. In addition, glass spacer 33 may be overcoated by a very thin layer 62 of a highly reflective metal such as Sn or Ag to provide maximum reflectivity of the ambient light 64 . Reflective metal layer 62 may be overcoated by a very thin layer 65 of a transparent inorganic or organic dielectric. In one of the alternative schemes, the highly reflective metal layer 62 can be deposited just before the application of the SU 8 dielectric or of the PMMA. Maximum use of incident light 64 is essential to realize bright, high contrast reflective displays 10 .
Second layer 26 and the third layer 27 are substantially similar to each other. Glass spacers 30 and 31 consist of a very thin glass in which a plurality of via holes have been etched. Alternatively, glass spacers 30 and 31 are prepared from a very thin highly transparent plastic such as polyethylene, polypropylene, poly methyl methacrylate (PMMA) or other suitable sheets of plastic (polymer). The vias in plastic can be made by punching, etching or the vias can be formed by any other suitable means of via formation. Etching can be made by casting the film over a “bed of Nails” on a casting surface and the dry film can be then pulled off the mandrel. To reduce the paralax, and the reflective losses and to widen the viewing angle, these intermediate layers of glass or polymer are preferably as thin as possible.
The vias created in the glass or in the plastic are filled in by one of many possible means such as copper electroplating, conductive metal filled paste or by solder fill such as described in U.S. patent application Ser. No. 09/383325 filed Aug. 26, 1999 (YOR919990165US1) by Gruber et al. which is directed to an injection molded solder (IMS) method for filling high aspect ratio via holes with solder in electronic substrates which application is incorporated herein by reference.
As in the case of the bottom TFT carrying plate, after via fill the surface of glass spacer 32 is planarized by mechanical or CMP process. Glass spacer 33 is metallized with an adhesion metal such as Ta, Ti, W, or Cr and a conducting seed plating metal such as Cu, Ni, Au etc. Glass spacer 33 is overcoated with Novolack resist and after an appropriate prebake, a pattern representing electrodes 38 - 40 is exposed and developed. Copper is now electroplated until it slightly overplated or mushrooms over the resist. The slightly overplated structure is mechanically or CMP processed to planarize. The Novolak resist is removed and the exposed seed and adhesion layers are removed thus leaving the areas which are not covered by the electrodes completely transparent. Plated electrode 22 is than overcoated with photosensitive epoxy resist such as SU 8 or PMMA and all organic resist is exposed and developed except for very thin layer on the walls of copper electrode 22 to prevent an electrical discharge of the electrophoretic particles. Copper electrode 22 is topped off with an electroless Co(P), or CoW(P), or CoSn(P) layer and is then immersion plated with a layer of Au for subsequent easy soldering.
Fourth layer 28 can be prepared the same way as the second layer 26 and the third layer 27 except the fabrication process is terminated at the planarization step after the via fill. Alternatively, this layer can be prepared by only partially etching into the glass or polymer plate and then back filling the blind vias with solder. FIG. 3 shows the details of a completed fourth layer 28 from glass spacer 31 and cover glass 32 ready to be joined.
When all electrodes 22 - 24 have been separately prepared, they are mechanically or optically aligned, clamped and heated in a vacuum or a reducing gas atmosphere to a temperature several degrees above the melting temperature of solder to produce a bond between the solder and the gold interfaces or surfaces.
The final assembly consists of the glass substrate with TFT's two glass substrates with electrophoretic cell electrodes and one cover glass as shown in FIG. 1 A.
Since there should be an electrical contact between cells in the vertical direction, the glass spacer 30 and glass spacer 31 in FIGS. 1A and 1B have holes in them. The holes are placed as shown in FIGS. 1A and 1B .
The holes in the glass are filled with a metal as shown in a series of sketches in FIG. 5A-5D . The metallurgy on TFT substrates and on the glass spacers 30 and 31 are fabricated in an identical fashion. Top cover glass 32 is metalized to permit assembly and rigid hermetic sealing.
The individual cell compartments are interconnected by a number of apertures or openings 45 near the corner to permit easy filling of the display with the electrophoretic or LC solution. The holes are placed at the corners as shown in FIG. 1 since the corners provide very little current or potential to the cell. This, therefore, does not affect the operation of the display.
The metallurgy used is copper followed by electroless Co(P) or CoW(P) and immersion Au strike and low temperature (70° C. to 300° C.) SnPb, SnBi, SnIn or SnGe. Alternatively, the copper can be replaced by Ni. The overcoat for metal is SU 8 resist (epoxy based negative UV resist) or PPMA. For solder joining, the assembly process is simple and partly self aligning.
Glass spacers 30 and 31 with holes are shown in FIGS. 1 and 1B . Glass spacers 30 and 31 may be Hoya photosensitive type glass supplied by Hoya Manufacturing Company located in Japan. Glass spacers 30 and 31 may be ordered with holes in them according to a supplied pattern.
In one variant of via fill, the glass is pressed against a conformable substrate such as metal filled epoxy, elastic polymer with a thin foil of Au or stainless steel on it. This substrate is used at the cathode. During electroplating, the metal plates on the cathode filling the vias and is allowed to overplate over the glass surface. The overplated metal is removed by mechanical polishing or chemical mechanical polishing (CMP). The planarized substrate attached to the metal carrier is processed further as shown in FIG. 5A-5E .
The planarized metal filled glass is sputtered with 200 Å with Ti, Ta or Cr adhesion layer and by 800 Å of Cu or 1000 Å of Ni seed plating layer. The planarized metal glass substrate still etched attached to the cathode is spun on with 8 to 15 micrometers of Novolak resist such as AZ4620. After mask alignment with the metal filled vias, AZ4620 is exposed and developed opening the metal seed layer. Ten to fifteen microns of Cu or Ni are then electroplated through the mask. The resulting copper filled AZ resist (Ni filled AZ resist) is polished or planarized by CMP. 2000-5000 microns of SnPb eutectic composition or SnBi, Snin or SnGe is electroplated. Then, the AZ resist is removed by blanket exposure with UV and development. The seed layer of Cu is removed by chemical or sputter etching followed by chemical removal of Ti or Ta using 1% of HF in water.
A layer of SU 8 or PMMA is applied by spinning or spraying and is cured. The resist is then planarized sufficiently to expose the electroplated solder SnPb, SnAg, SnBi, Snin or SnGe. A mask is exposed and developed which leaves very thin dielectric on the sides of the metal walls.
After removal of glass spacer 30 from the substrate (cathode carrier) the parts are dipped into an electroless Sn or In solution to overcoat the metal by thin solder 2000 to 3000 Å.
When all individual parts are completed they are aligned, clamped, and heated in a vacuum or a reducing gas atmosphere. When the melting temperature of the solder is reached, the interdiffusion of solder and metal (Au) takes place and a solder joint takes place. The assembly is then cooled to room temperature. The individual spaces (layers) are then filled by various color (RGB) electrophoretic fluids or by LC material to form layers 26 - 28 and the part is sealed.
The top cover plate shown in FIG. 5F is a top view. FIG. 5G is a cross section view along the line 5 G— 5 G of FIG. 5 F. The glass is prepared in the following way. The glass is coated with Novolak type resist for example AZ4620 and is exposed with pattern with a slight overhang. The glass is then etched about 5000 Å to 10,000 Å deep with HF. After rinsing, it is sputtered with 500 Å of Ta, Ti or Cr and a lift off is performed thereby filling the grooves. Alternatively, electroless Ni is plated into the grooves. The plated Ni is then overcoated with a thin layer of Sn, SnPb, SnAg, SnIn or SnGe.
The vias in glass spacers 30 and 31 can alternatively be filled by using a conducting paste which was pushed or squeezed into the vias and cured after filling. Due to shrinkage of the paste, a second fill with fresh paste may be necessary. The glass with the conducting filled paste is then planarized as it was for Cu plating but the planarization now must be done on both sides. The electrodes are now formed on the glass with metal paste filled vias in the same way as it was done in case of Cu filled vias.
After the solder fill, the electrode formation process is the same as described in the case of copper via fill process.
Further examples of the fabrication process are given.
In one approach, vias are made in glass, transparent plastic such as polypropylene, Poly Methyl Methacrylate (PMMA) or silicon based plastic. The vias are filled by conducting metal which can be copper, nickel, permalloy or solder such as PbSn, Sn Bi, SnAg or Snln, SnGa, etc.
The filling can be accomplished by (1) electroplating, or (2) electroless plating with Cu, NiP, NiB, or any other electroless metal or a metal alloy.
When filling vias deep or long vias such as in glass spacers 30 and 31 , the walls of the vias, to improve solder wetting and adhesion, may be first metallized by suitable metallization such as evaporation, sputtering, or electroless plating with Cr/Cu, Ta/Cu, Ta/Cu/CoP/Au, Co(P)/Au, etc.
For further processing and stacking the layers, it is desired after the via fill to planarize the surface on each side of glass spacers 30 and 31 after filling the vias therein. Such planarization can be accomplished by mechanical or by Chemical Mechanical Polishing (CMP).
When copper is used, the CMP process may be similar to the CMP process used in preparation of copper interconnects on semiconductor chips which is well known in the art by chip manufacturers.
When instead of forming vias by plating or solder fill, metal studs or wires 60 may be used as shown in FIGS. 6A-6C . In FIG. 6A metal vias 60 are positioned in a polymer by hot pressing and molding. In FIG. 6B , metal vias 60 are positioned in a polymer by casting or doctor blading of polymer. In FIG. 6C , Cu balls overcoated with electroless CoW(P) and immersion Au are positioned in a polymer by hot molding. It may also be necessary to planarize the surface. In such case CMP or mechanical planarization methods can be used.
When the structure is used to prepare an electrophoretic display the separators between the individual layers serve at the same time as electrodes.
The easiest way to form such electrodes is by electroplating. The electroplating can be accomplished by the plating through mask technology described in L. T. Romankiw, Electrochemica. Acta., vol. 42, No.20-22, (1997) 2985.
In this process, the surface is first metallized with adhesion and conducting plating seed layers by sputtering, evaporation or plating of layers such as Cr, Ti, Tc, Ta, W, Ni, NiFe etc followed by a conducting layer such as Cu, Au, Zu, Ni etc. A photoresist layer is applied such as AZ resist, Shippley, PMMA, etc. A mask with a suitable pattern such as shown in FIG. 1A is exposed and developed. After development, any remaining resist residue from developed areas is removed by ashing by plasma treatment in a suitable gas such as forming gas H2/N2 mixture, O2/N2 mixture etc.
The exposed pattern is then filled by electroplating with copper or another suitable conducting metal until the metal mushrooms out of the resist grooves as shown in FIG. 5 C. The planarizaiton is accomplished in an identical way as described above under CMP.
After planarization, the resist is removed by blanket exposure to TV and development or by a suitable organic solvent which does not attack the electroplated copper (Ni, etc.) The electrode pattern process formation is completed by sputter etching, chemical, electrochemical and chemical method. Upon completion of this process, the substrate becomes completely transparent. For subsequent easy joining to the layers, it may be desired to immersion coat the copper with Sn, or Ag. Both Sn and Ag are white reflective metals and thus additionally help create white background in the display and hence better reflection and better contrast.
The above process can be used to prepare each individual layer except for the first TFT carrying (bottom layer) and the fourth (top cover) laye 32 .
While the TFT carrying substrate can be completely separate and can be joined to the layers above by soldering in the same way as all the layers are joined together, the TFT substrate can also be used as a first electrode forming substrate.
If the latter is the case, the TFT carrying substrate is covered by a suitable insulator, such as SiO 2 , Al 2 O 3 , etc, vias are open in the insulator to make appropriate electrical contacts and the substrate is then processed as described earlier under electrode formation (or the transparent glass spacer).
A thin adhesion (diffusion barrier layer) is applied followed by thin plating seed layer using suitable means such as Cu, Ni, etc by evaporation or electroless plating. A thick resist layer is applied, UV exposed, developed and organic resist residue is ashed. Copper is electroplated, planarized. Then, the resist, plating seed and adhesion layers are removed, and immersion Sn or Ag is deposited on Cu.
In one version the top or cover glass 32 can be prepared by forming vias similarly as in all other cases and filling the vias with copper, Ni or solder. Because no electrodes are necessary on the top layer after planarizing the vias the top side of the cover glass 32 may be covered by a thin layer of transparent inorganic or organic layer. This layer can be SiO 2 , Al 2 O 3 or PMMA, Polypropylene, polyethylene etc. This coating can be done either prior to joining or after the structure has been joined together.
In an alternate approach the bottom side of the cover glass 32 may be patterned with a pattern as shown in FIGS. 1D , 3 and 5 F. The bottom side of the substrate is then sputtered in a sheet form with adhesion layer such as Cr, Ti, Ta, W, etc followed by thin Cu, Au or Ag layer. The excess metal is then removed by polishing, leaving metal only in recesses. The blind vias are then filled with SnPb or any by other solder using injection moled solder (IMS) such as described in U.S. Pat. 09/363,325 by Gruber et al. or any other suitable material such as solder paste.
After solder filling, the excess solder is removed by mechanical polishing CMP means. The final structure is assembled by aligning all the layers using optical means or a suitable mechanical means. The mechanical means may consist of slipping the layer with suitably located pins on a substrate as shown in FIG. 7 and clamping the structure together. The clamped structure is then joined by heating and soldering all the layers together at a suitable melting temperature of solder chosen for this step. The soldering is done preferably in reducing atmosphere or in vacuum. No flux is used so as not to leave a surface residue which may interfere with operation of the display.
If copper was not pre-coated with Sn, Ag or Au, it is desired to expose such copper surface to a fluorocarbon containing plasma. This replaces oxygen from copper and makes it easier to join to solder.
It should be noted that it is possible to use only a very low temperature solder such as SnPb, Snin, SnGa. The use of low temperature solder is will promote quick and easy joining. By providing a suitable material such as Au, Ag, or Cu as contact layer and holding the structure together tat the soldering time and for a time longer than necessary to just melt the metal, to wet and to solder. By heating for a longer time, it is possible to form a joint which will withstand, in the future, higher temperatures due to diffusion of enough Au, or Ag or Cu into the Sn, SnPb, SuIn or SnGa solder so that a higher melting solder is formed (ie. SnPbAu, SnPbCu,SnInCu, SnGaAu or SnGaCu or SnPb with Sn content higher than that of a eutectic composition).
While the process has been demonstrated in the batch mode, a much cheaper process would be to provide the same process on a reel to reel automated line. Such line is shown in FIG. 8. A thin polymer 100 is fed off reel 101 having alignment sprockets 102 . Into the hole or via fabrication station, station 103 , there are four ways to generate the vias such as by punching, chemical etching followed by solder fill, conductive paste fill or Cu electroplating as described earlier. Alternatively, the metal wires or metal balls may be pressed into a soft polymer without having to create holes for the wires thus imbedding the metal vias into a heated plastic or polymer 100 . Alternatively, one can cast the polymer over the metal particles or wires to form the vias upon hardening of the polymer.
The thin polymer with vias or tape is then fed into a planarization station 104 in which both sides are planarized by mechanical or CMP method to expose the metal and make it planar with the metal. The tape from station 104 is fed to station 105 in which one side of the tape is metalized with 100 to 200 angstroms of adhesion metal such as Ti, Ta, or Cr followed by 800 to 1000 angstroms of Cu seed plating layer. The tape is then fed into photolithography station 106 in which photoresist (AZ4620 or similar) is applied by rolling on or spraying, doctor blading or any other suitable means. The resist thickness may be in the range from 8 to 15 microns. The resist is then dried. The patterns are exposed, developed and the resist residue is removed by ashing. The tape is then fed into a copper electroplating station 107 where 10 to 15 microns of Cu is electroplated through the mask. The plated tape is now planarized in a station 108 using CMP so the Cu and resist are coplanar. The tape from station 108 is fed to station 109 where the resist is removed by blanket UV exposure and development. The tape is then moved to station 110 where the seed layer and the adhesion layers are removed by chemical or sputter etching means. The tape with Cu electrodes created is fed into a station 112 where the photosensitive dielectric such as SU 8 or PPMA is applied by rolling on or spraying. The photosensitive dielectric is cured and fed into station 113 where it is planarized until the copper is exposed. The tape is then fed into station 114 where a mask is aligned and the photosensitive dielectric is exposed and developed and ashed to remove the resist residue leaving the sidewalls of the metal electrodes coated with a thin dielectric. This is essential to prevent electrophoretic particles from discharging on bare metal. The tape is now fed into an electroless plating station 115 in which Pd activation takes place and is followed by CoW(P) plating, and by immersion Au plating. The tape is then cut into individual substrates in station number 116 . The individual substrates are then aligned with TFT's substrates and are clamped together in station 117 . The assembled clamped parts are moved to station 118 where they are heated in vacuum or a reducing atmosphere until a metal joint between solder and Au takes place. The substrates are moved to station 119 where cavities in individual layers are filled with electrophoretic fluids or LC fluids. The filled displays are moved to station 120 where they are sealed and sent for testing in station 121 .
In an alternate version as shown in FIG. 9 , tapes 81 - 84 produced in several parallel stations the cover tape 84 , the inner tape 83 and the inner tape 82 and the bottom tape 81 with the TFT's are brought together in station 130 where the patterns on the respective tapes are aligned with respect to each other. The four tapes 81 - 84 are clamped or pressed together and transferred into station 131 where vacuum and/or reducing atmosphere are applied and the tape is heated to about the melting temperature of the solder used. This results in interdiffusion of solder and Au creating a higher melting temperature solder and the solder and Au become a glue with respect to the substrates they were originally on. The tape is then passed into a cooling chamber 132 where it is slowly cooled to room temperature. From Chamber 132 , it is passed into a cutting chamber where individual displays are cut. The individual displays are passed into chamber 133 where the spaces between the layers are filled with different electrophoretic fluids or LC materials. From chamber 133 , the displays are passed into chamber 134 where they are sealed and then into chamber 135 where the displays are tested. If only polymer or thin glass substrates or tapes are used in creating the displays, the displays will be flexible and can be bent or curved without damage. More layers can be inserted for addition vertical cells to gain additional color tinges and improved sharpness by using black and/or white in addition to the three primary colors RGB.
Referring back to FIG. 2 , the preferred embodiment a guest host stacked LC display 50 is shown. Like in the electrophoretic display 10 shown in FIGS. 1 , 1 A- 1 C, use is made of several glass or polymer substrates 51 , 53 and 55 . The first step in the process consists of forming vias in the glass or polymer substrates 51 and 53 . If the Hoya photosensitive glass is used, the substrates can be purchased from the Hoya Corporation in Japan. The pattern layout is produced as desired for a given display. After forming vias, both sides of the glass substrates 51 and 53 and one side of substrate 55 are sputtered with indium tin oxide (ITO) as shown in FIG. 2 . Referring to FIGS. 10A and 10B , one side of substrate 53 , has ITO 200 which extends all the way to the edge of the via 202 so as to make electrical connection with copper 201 plated inside the via 202 . The copper is electrolessly plated inside the via and subsequently etched to form flanges 203 and 204 on each side of the glass substrate 53 . Flange 204 makes electrical contact with ITO while flange 203 stopes short of ITO 206 . The flanges are defined by, for example, chemical etching or other suitable means. ITO 206 may be etched away from via 202 to make an electrical break between the copper flange 203 and ITO 206 . As shown in FIG. 10C , ITO 200 is printed with a polyimide 207 pattern which functions to orient the LC material when applied. As shown in FIG. 10D , polyimide 208 is printed on ITO 206 to orient the LC material when the LC material is applied. At this point, the copper vias and flanges 203 and 204 are activated with Pd and electrolessly plated with CoW(P) 210 and subsequently immersion coated with Au 211 . The vias 202 are then filled with PbSn solder 212 by the IMS technique described above. If necessary, both sides are planarized and solder reflowed. The substrates are then stacked in the proper order, aligned and clamped between two plates and heated to above the melting point of the solder to create the solder joint between the individual substrates. The height of the flanges 203 and 204 defines the separation gap between the respective substrates and becomes the space which is eventually filled with the liquid crystal material containing dyes. Table I shows the smallest via dimensions that can be produced in various substrate thicknesses (aspect ratio) and also shows the aperture ratio in percentages for different sized vias in a 300 micron square pixel.
TABLE 1 Aperture ratio (%) Substrate Via Diameter (3 vias in 300 Microns thickness (Microns) (Microns) □ 300 microns) 500 90 79 200 36 97 100 18 99 FIG. 10E shows a top view of ITO 200 with flange 204 making electrical connection to ITO 200 . Flange 220 and 221 are isolated by a space from ITO 200 to permit electrical connection to higher level cells. FIG. 2 shows the completed three layer structure filled with cyan, magenta and yellow dyes. In operation with a potential on the three ITO's, the spectral response corresponding to the respective layer is shown in FIG. 10 F.
In an alternate embodiment, the substrates may alternate in having vias filled with solder since the soldering will seal the opening. This approach does not require as careful precleaning of the solder before joining because the solder in one substrate connects to a Au plated flange in the second substrate. In a third alternate embodiment, none of the substrate vias are filled with solder but the bonding is done by Au to Au diffusion bonding at elevated temperature such as 300 C or higher.
FIG. 11 shows a cross sectional view of a one layer Organic Light Emitting Diode (OLED) display 240 . The single level has three cells 241 - 243 side by side. Each cell (Pell) has a different color. Since the pells are very small the human eye sees only the color which was turned on. The other two pells which are not turned on are white or the background color. Since the background is aluminum, it appears to the human eye white. OLED display 240 is a reflective display. While it is showing that it is filled with air 250 , in reality it is either evacuated or is filled with dry air. The edges are sealed off with UV curable epoxy. Before sealing, it can be either evacuated to create some vacuum or is filled with dry air. Moisture is deleterious to the operation if allowed to enter the air space. OLED display 240 is common with the other embodiments herein in that two pieces of glass are used; one glass plate has the TFT's and the metal contacts. The other glass plate has a layer of sputtered indium tin oxide (ITO). Over the ITO is evaporated OLED which may be patterned by sputtering through a mask. Over the OLED is evaporated, presumably also patterned, an aluminum electrode which also functions as a reflective surface. On top of the aluminum electrode is formed a metal conductor such as copper, nickel, and which may be overcasted with gold. Since the glass with the TFT and the conductor has either solder or gold on top, the two plates may be brought together, compressed and heated. The two conductors on repective glass plates join either by thermal compression bonding when both sides are finished with gold, or by soldering together when one side is gold and the other is a soldering type metal. The two glass parts may be fabricated separately and then they are either soldered or compression bonded together.
FIG. 12 is a schematic cross sectional view of a three layer stacked reflective OLED display 260 . The pels are on top of each other. As in a liquid crystal display, the bottom of each glass is a cathode and a common ground electrode except where the cathode is not ITO as in the liquid glass display but is very thin evaporated or sputtered metal (i.e. 100 Angstroms of aluminum or tantalum or titanium or some other metal which when it is very thin it is conductive yet it is nearly completely transparent. The cathode is evaporated with the OLED material. Each level has a different color OLED material. When not activated by a potential, the material is colorless and transparent. Therefore in reflection, one sees only the mirror, which is made of aluminum (thick) or ailver or Sn or some other white mirror material. The opposite side of the compartment of each pell has a patterned ITO anode which is connected to the metalized via like in the liquid crystal display. The TFT may activate a given pell on a given level to generate a color. When the TFT activates the bottom level, a blue color appears. If a TFT activated the ITO on the middle level, a red color is seen. The other two levels remain colorless and transparent until activated. When the TFT activates the top level, a green color appears.
The embodiment of FIG. 12 is common with the other embodiments in that each glass plate is fabricated separately, equipped with the via holes which are at least partially filled with a conducting metal or metal layers which are finished with either gold or a solder surface so that when the whole thing is aligned it can be pressed together and joined under pressure and temperature. The bottom plate called the driving plate contains prefabricated TFT devices each connected to a separate vertical via connection and terminated with an ITO patterned anode. | A structure and fabrication technology for a reflective, ambient light, low cost display is described incorporating a plurality of cells laid out side by side and stacked as many as three levels on top of each other. Each stack of three cells being driven by an array of TFT's positioned on the bottom layer. Each cell comprises a light transmitting front window, three levels of individual cells RGB (Red, Green, and Blue) stacked on top of each other, each level having its own individual electrode, each electrode being connected by vertical conducting via holes running through each transparent dielectric spacert and being connected to a individual TFT. The bottom panel having a reflective surface so as to provide maximum reflectivity of the ambient light. Placed under the reflective surface is an array of TFT's which provide the electrical impulses necessary to set each individual potential in each vertically stacked cell with respect to ground potential. A transmissive liquid crystal display can readily be fabricated by deleting the reflective surface. Also described are structures and assembly methods suitable for fabricating a Guest-Host LCD, a Cholesteric LCD, a Holographic Polymer Dispersed LCD and an Organic Light Emitting Diode (OLED) display. | 6 |
TECHNICAL FIELD
[0001] The present invention relates to a method of measuring misalignment (overlay) between patterns created in different manufacturing processes in manufacture of a semiconductor wafer, a device therefor, and a display method therefor, and more specifically to a method of measuring overlay by using an image obtained through photographing with a charged particle microscope, a device therefor, and a display device therefor.
BACKGROUND ART
[0002] For semiconductor device products, a plurality of times of exposure processes are required to form a circuit pattern required for operation. For example, in manufacture of a device formed of multilayered circuit patterns, in addition to the exposure process for forming each layer of the circuit pattern, an exposure process for forming a hole connecting together the layers is required. Position of the circuit patterns formed through the aforementioned plurality of times of exposure processes needs to fall within a permitted range, and upon deviation from the permitted range, appropriate electric characteristics cannot be obtained, resulting in yield deterioration. Thus, measurement of circuit pattern misalignment (overlay) between the exposures and feedback thereof to an exposure device have been practiced.
[0003] Following miniaturization of semiconductor processes, the permitted overlay range has become smaller and thus has become important to directly measure the overlay in a place where the product circuit pattern is formed. To realize this, Japanese Patent Application Laid-open No. 2013-168595 (Patent Literature 1) describes a technique of photographing an image of a product circuit pattern with a scanning electron microscope (SEM) and measuring overlay.
[0004] The overlay measurement method described in Patent Literature 1 measures the overlay through image positional alignment between a reference image and a measured image, and FIG. 30 in Patent Literature 1 describes a method of providing a display of measurement results as detection results of a differential part between the reference image and the measured image.
[0005] Japanese Unexamined Patent Application Publication No. 2005-521254 describes a method of coloring a reference image and an inspected image to make a difference therebetween visible. More specifically, the method refers to an inspection method of image comparison between the reference image and the inspected image and a method of obtaining an inspected defective image by image coupling of a framework image of the colored reference image, an edge framework image of the colored reference image, and an inspected object of the colored inspected image.
CITATION LIST
Patent Literature
[0006] PTL 1: Japanese Patent Application Laid-open No. 2013-168595
[0007] PTL 2: Japanese Unexamined Patent Application Publication No. 2005-521254
SUMMARY
Technical Problem
[0008] Patent Literature 1 describes that the overlay measurement based on the product circuit patterns of a semiconductor device is carried out by performing image positional alignment between the different patterns of the reference image and the measurement image targeted for the overlay measurement. Comparison between the reference image and the measurement image is a practical method in the overlay measurement targeted on the product circuit patterns, but it is required to visually check a state of the image positional alignment for the purpose of adjustment of an image processing parameter used for the image positional alignment and for the purpose of confirmation of the measurement results.
[0009] In a case where a targeted process of the overlay measurement is a hole process, that is, in a case where there is positional misalignment between a hole formed at an upper layer and a pattern formed at a lower layer located at a hole bottom observed through the aforementioned hole, gray of an image obtained by photographing, with an SEM, the pattern formed at the lower layer observed through the hole bottom is relatively smaller than gray of an SEM image of the hole pattern formed at the upper layer, and thus upon direct mutual superposition of the reference image and the measurement image obtained in the hole process by photographing with a scanning electron microscope, it is difficult to visually confirm a state of the positional alignment of the hole bottom pattern.
[0010] Patent Literature 1 describes that as the method of displaying the results of the positional alignment between the reference image and the measurement image, the detection results of the differential part between the reference image and the measurement image are displayed. Described as the method of detecting a differential part is a method of calculating a difference in a gray value after the positional alignment between the reference image and the measurement image and defining, as the differential part, a region including pixels where a value of the difference becomes equal to or larger than a given value.
[0011] FIG. 1 and FIG. 2 illustrates schematic diagrams of an image obtained by photographing, with an SEM, hole patterns formed on a circuit pattern of a semiconductor in a hole formation process. Illustrated in the schematic diagrams is how a lower layer pattern 103 at a hole bottom of a hole pattern 102 formed at a surface layer 101 is viewed. FIG. 1 is the schematic diagram illustrating a state in which there is no misalignment (overlay) between the hole pattern 102 and the lower layer pattern (pad in examples of FIG. 1 and FIG. 2 ) 103 , resulting in a reference image. FIG. 2 illustrates a measurement image in a state in which there is misalignment (overlay) between the hole pattern 102 and the lower layer pattern 103 at the hole bottom. It is illustrated that an a base 201 of the layer on which the lower layer pattern 103 viewed at the hole bottom of the hole pattern 102 is viewed is observed darker. On the scanning electron microscope, electrons detected from the pattern formed at the lower layer at the hole bottom of the hole pattern 102 is smaller than electrons detected from the upper layer 101 on the surface, so that the lower layer pattern 103 at the hole bottom becomes darker.
[0012] FIG. 3 and FIG. 4 are obtained by mutually superposing and line-drawing the reference image of FIG. 1 and the measurement image of FIG. 2 . Broken lines of FIG. 3 and FIG. 4 represent an edge 304 or 404 of the hole pattern 102 and the lower layer pattern 103 at the hole bottom in the reference image of FIG. 1 , and solid lines represent an edge 303 or 403 of the hole pattern 102 and an edge 302 or 402 of the lower layer pattern 103 at the hole bottom in the measurement image of FIG. 2 . With the method described in Patent Literature 1 , image positional alignment is performed on an individual pattern basis. A diagrammatic view 301 of FIG. 3 represents an example where the positional alignment is performed properly with the edge 304 of the lower layer pattern 103 at the hole bottom obtained from the measurement image of FIG. 1 and the edge 302 of the lower layer pattern 103 at the hole bottom obtained from the measurement image of FIG. 2 , and a diagrammatic view 401 of FIG. 4 represents an example where the positional alignment was not performed properly with the edge 404 of the lower layer pattern 103 at the hole bottom obtained from the reference image of FIG. 1 and the edge 402 of the lower layer pattern 103 at the hole bottom obtained from the measurement image of FIG. 2 .
[0013] Ways of superposition of regions 311 to 313 and 411 to 415 marked with numerals in FIG. 3 and FIG. 4 are different from that of regions 101 to 103 and 201 marked with numerals in the reference image of FIG. 1 and the measurement image of FIG. 2 , and there is also a difference in a gray value between the reference image of FIG. 1 and the measurement image of FIG. 2 . In actual images, there is brightness non-uniformity in the regions marked with the numerals in FIG. 1 and FIG. 2 , and since the regions marked with the numerals in FIG. 1 and FIG. 2 are photographed at different positions of the device, thus resulting in non-uniformity in the gray value. Thus, the gray value roughly differs among the regions illustrated in FIG. 3 and FIG. 4 , but the difference therebetween becomes more unclear, thus resulting in difficulties in clearly indicating the regions as illustrated in FIG. 3 and FIG. 4 in the difference in the gray value. Therefore, as in Patent Literature 1, even when a region such that a differential part between the reference image and the measurement image becomes equal to or larger than a given value is displayed, it is difficult to judge whether or not image positional alignment has properly been performed by each pattern.
[0014] Patent Literature 2 describes a method of performing coloring on a reference image and an inspected image and detecting a difference between the reference image and the inspected image. However, positional alignment between the reference image and the inspected image is not performed with reference to either one of the patterns targeted for overlay measurement, thus resulting in failure to display results of the image positional alignment performed as the overlay measurement. Moreover, even when the positional alignment is performed with each pattern targeted for the overlay measurement, an image which permits judgement whether or not the image positioning has properly been performed cannot be obtained even by image coupling, through logical calculation, a frame image of the reference image or an edge image and an inspected object of the inspected image.
[0015] Bold lines 501 and 601 of FIG. 5 and FIG. 6 indicate results of taking, as inspected objects, a logical product of the edge image 302 or 402 of the lower layer pattern 103 at the hole bottom of the reference image in FIG. 3 and FIG. 4 and regions 312 , 412 , and 414 of the lower layer pattern of the measurement image in FIG. 3 and FIG. 4 . Thin lines 502 and 503 of FIG. 5 and thin lines 602 to 604 of FIG. 6 refer to line drawings illustrated in FIG. 3 and FIG. 4 . With only the bold lines 501 and 601 illustrated in FIG. 5 and FIG. 6 , it cannot be judged whether or not the positional alignment has properly been performed.
[0016] The present invention address the problem of the conventional art, and provides, in a method of overlay measurement through comparison between a reference image and a measurement image based on a product circuit image of a semiconductor device obtained by photographing with a scanning electron microscope, an overlay measurement method, a device and a display device capable of easily confirming results of the comparison between the reference image and the measurement image.
Solution to Problem
[0017] To address the problem described above, the present invention refers to a method of measuring overlay between patterns formed at different layers of a semiconductor device, and the method includes: acquiring a reference image including a pattern without overlay as misalignment between the pattern formed at the upper layer of the semiconductor device and the pattern formed at the lower layer thereof by using a scanning electron microscope; acquiring a measurement image including the pattern targeted for the measurement and formed at the upper layer of the semiconductor device and the pattern formed at the lower layer thereof by using the scanning electron microscope; calculating a positional misalignment amount of the patterns corresponding to the acquired reference image and the acquired measurement image; generating a differential reference image and a differential measurement image through differential processing performed on the acquired reference image and the acquired measurement image; generating a colored differential reference image through coloring with a first color having an intensity value corresponding to a gray value of the generated differential reference image and generating a colored differential measurement image through coloring with a second color being different from the first color and having an intensity value corresponding to a gray value of the generated differential measurement image; performing positional correction on the colored differential reference image or the colored differential measurement image by using information of the calculated positional misalignment amount of the pattern; and mutually superposing the colored differential reference image and the colored differential measurement image subjected to the positional correction and displaying the colored differential reference image and the colored differential measurement image together with the information of the calculated positional misalignment amount of the patterns.
[0018] Moreover, to address the problem described above, the invention refers to an overlay measurement device which measures overlay of patterns formed at different layers of a semiconductor device, and the overlay measurement device includes: scanning electron microscopic adapted to acquire a reference image by imaging a region including the pattern without overlay as misalignment between the pattern formed at the upper layer of the semiconductor device and the pattern formed at the lower layer thereof, and to acquire a measurement image by imaging a region including the pattern targeted for the measurement and formed at the upper layer of the semiconductor device and the pattern targeted for the measurement and formed at the lower layer of the semiconductor device; positional misalignment amount calculator adapted to calculate an amount of positional misalignment between the patterns corresponding to the reference image and the measurement image acquired by the scanning electron microscope; differential image generator adapted to generate a differential reference image and a differential measurement image by subjecting, to differential processing, the reference image and the measurement image acquired by the scanning electron microscope; colored differential image generator adapted to generate a colored differential reference image by coloring in a first color having an intensity value corresponding to a gray value of the differential reference image generated by the differential image generator, and generating a colored differential measurement image by coloring in a second color being different from the first color and having an intensity value corresponding to a gray value of the differential measurement image generated by the differential image generator; image positional corrector adapted to perform positional correction on the colored differential reference image or the colored differential measurement image generated by the colored differential image generator by using information of the amount of the positional misalignment between the patterns calculated by the positional misalignment amount calculator; and display unit adapted to mutually superpose the colored differential reference image and the colored differential measurement image subjected to the positional correction performed by the image positional corrector, and to display the colored differential reference image and the colored differential measurement image together with the information of the amount of the positional misalignment between the patterns calculated by the positional misalignment amount calculator.
[0019] Further, to address the problem described above, the invention refers to a device displaying measurement results of overlay of patterns formed at different layers of a semiconductor device, the measurement being achieved through comparison between a reference image in a region including the pattern without overlay as misalignment between the pattern formed at the upper layer of the semiconductor device and the pattern formed at the lower layer thereof both of which are acquired by photographing with a scanning electron microscope and a measurement image in a region including the pattern targeted for the measurement and formed at the upper layer of the semiconductor device and the pattern targeted for the measurement and formed at the lower layer of the semiconductor device, wherein a colored differential reference image obtained by coloring in a first color having an intensity value corresponding to a gray value of a differential filter image of the reference image and a colored differential measurement image obtained by coloring in a second color different from the first color and having an intensity value corresponding to a gray value of a differential filter image of the measurement image are superposed on each other to be displayed.
Advantageous Effects of Invention
[0020] With one aspect of the present invention, in overlay measurement performed with a product circuit of a semiconductor device through comparison between a reference image and a measurement image by using an SEM image obtained by photographing the semiconductor device with a scanning electron microscope (SEM), when the reference image and the measurement image are shifted for superposed display thereof, the superposed display can be performed with favorable visibility.
BRIEF DESCRIPTION OF DRAWINGS
[0021] FIG. 1 is a schematic diagram of an image obtained by photographing, with a scanning electron microscope, a semiconductor device on which a hole pattern has been formed through a hole pattern formation process, illustrating a state in which there is no misalignment between the hole pattern and a pattern formed at a lower layer.
[0022] FIG. 2 is a schematic diagram of a measurement image in a hole process, i.e., the image obtained by photographing, with the scanning electron microscope, the semiconductor device on which the hole pattern has been formed through the hole pattern formation process, illustrating a state in which there is misalignment between the hole pattern and the pattern formed at the lower layer.
[0023] FIG. 3 is a line drawing obtained by extracting edges of the patterns respectively observed on the reference image of FIG. 1 and the measurement image of FIG. 2 , illustrating a state in which positional alignment has been properly performed based on the pattern edges extracted from the respective images.
[0024] FIG. 4 is a line drawing obtained by extracting the edges of the patterns respectively observed on the reference image of FIG. 1 and the measurement image of FIG. 2 , illustrating a state in which the positional alignment has not been properly performed based on the pattern edges extracted from the respective images.
[0025] FIG. 5 is a diagrammatic view illustrating, in a bold line, an edge portion of a pattern formed at the lower layer of the hole pattern as a result of taking AND of an edge image of the pattern formed at the lower layer of the hole pattern in the reference image and a region of the pattern formed at the lower layer of the hole pattern in the measurement image, which are provided as inspected objects.
[0026] FIG. 6 is a diagrammatic view illustrating, in a bold line, an edge portion of a pattern formed at the lower layer of the hole pattern as a result of taking AND of an edge image of the pattern formed at the lower layer of the hole pattern in the reference image of FIG. 4 and a region of the pattern formed at the lower layer of the hole pattern in the measurement image, which are provided as inspected objects.
[0027] FIG. 7 is a block diagram illustrating schematic configuration of an overlay measurement device according to Example of the present invention.
[0028] FIG. 8 is a partially sectional view of a semiconductor device having a contact plug formed at a lower layer and a hole pattern formed on an upper layer, illustrating a state in which there is no misalignment between the contact plug at the lower layer and the hole pattern at the upper layer.
[0029] FIG. 9 is a schematic diagram of an image obtained by photographing the semiconductor device in the state of FIG. 8 with a scanning electron microscope.
[0030] FIG. 10 is a partially sectional view of a semiconductor device having a contact plug formed a lower layer and a hole pattern formed at an upper layer, illustrating a state in which there is misalignment between the contact plug at the lower layer and the hole pattern at the upper layer.
[0031] FIG. 11 is a schematic diagram of an image obtained by photographing the semiconductor device in the state of FIG. 10 with the scanning electron microscope.
[0032] FIG. 12 is a flowchart illustrating procedures of processing of calculating overlay according to Example of the invention.
[0033] FIG. 13 is a flowchart illustrating procedures of generating an image displaying the overlay according to Example of the invention.
[0034] FIG. 14 is a flowchart illustrating procedures of generating a reference image and a measurement image involved in mask processing according to a modified example of Example of the invention.
[0035] FIG. 15 is a diagram illustrating a state in which display images 1310 and 1315 are superposed on each other according to the modified example of Example of the invention.
[0036] FIG. 16 is a diagram displaying, in a vector, a change in a representative position of a hole pattern in the state in which the display images 1310 and 1315 are superposed on each other according to the modified example of Example of the invention.
[0037] FIG. 17 illustrates an example of a display image in a state in which a measurement image is superposed on the display image 1310 of FIG. 13 according to the modified example of Example of the invention.
[0038] FIG. 18 illustrates an example of a display image in a state in which a reference image is superposed on the display image 1310 of FIG. 13 according to the modified example of Example of the invention.
[0039] FIG. 19 is a flowchart illustrating procedures of processing of measuring overlay according to Example of the invention.
[0040] FIG. 20 is an elevation view of a display screen illustrating configuration of a screen displaying results of measuring the overlay according to Example of the invention.
DESCRIPTION OF EMBODIMENTS
[0041] The present invention relates to measurement of pattern overlay between layers circuit patterns formed at multiple layers of a semiconductor device, and permits superposed display with favorable visibility when a reference image and a measurement image provided by an SEM image obtained by imaging the circuit patterns are subjected to positional correction in accordance with an overlay amount obtained by using the reference image and the measurement image and are displayed in a mutually superposed manner.
[0042] Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Embodiment 1
[0043] FIG. 7 shows an overall configuration diagram of an overlay measurement device 1000 according to the present invention. The overlay measurement device 1000 includes a scanning electron microscope device 700 and a processing and control section 750 .
[0044] The scanning electron microscope device 700 includes: a stage 706 on which a semiconductor wafer 707 is loaded; an irradiation optical system 710 controlling an electron beam 701 emitted from an electron gun 702 ; and a detector 708 detecting a secondary electron or a reflective electron 709 emitted from above a sample (the semiconductor wafer 707 ) to which the electron beam 701 is irradiated. The irradiation optical system 710 includes the electron gun 702 , capacitor lenses 703 ; deflection coils 704 , and objective lenses 705 which are located on a route of the electron beam 701 . The electron beam 701 is focused by the irradiation optical system 710 on a predetermined region in which a defect to be observed is exist on the semiconductor wafer 707 .
[0045] The processing and control section 750 includes: an A/D converter 751 , an image processing section 752 , an overall control section 753 , an electron optical system control section 754 , a stage controller 755 , and a display terminal 756 .
[0046] On the scanning electron microscope device 700 , a detection signal outputted from the detector 708 that has detected the secondary electron or the reflective electron emitted from the semiconductor wafer 707 , to which the electron beam 701 has been emitted, is converted into a digital signal by the A/D converter 751 . The digital signal obtained through the conversion is transmitted to the image processing section 752 , in which image processing is performed using the digital signal transmitted from the A/D converter 751 , for example, detection of a defective position in an image is performed, and then results of the aforementioned operation is outputted to display at the display terminal 756 via the overall control section 753 . In response to a control signal from the overall control section 753 , the stage controller 755 drives the stage 706 of the scanning electron microscope device 700 . In response to the control single from the overall control section 753 , the electron optical system control section 754 controls, for example, the electron gun 702 , the capacitor lenses 703 , the deflection coils 704 , and the objective lenses 705 of the scanning electron microscope device 700 .
[0047] A recording medium (not illustrated) can be connected to the image processing section 752 , the overall control section 753 , and the display terminal 756 , and a program to be executed in the image processing section 752 can be read from the recording medium and loaded onto the image processing section 752 .
[0048] In a description of overlay measurement below, an example of a device pattern formed on the semiconductor wafer 707 and targeted for the measurement will be described with reference to schematic diagrams of FIG. 8 and FIG. 10 and an example of a captured image of the device pattern will be described with reference to FIG. 9 and FIG. 11 .
[0049] FIG. 8 is a schematic cross-sectional view with a simplified partial cross section of a semiconductor device having a contact plug 804 formed at a lower layer 802 (although omitted from illustration, a thin film of a contact pad having almost the same diameter as that of the contact plug is formed on a surface of the contact plug 804 , and in the example of FIG. 1 , the contact pad is actually observed) and having a hole pattern 803 formed at an upper layer 801 , illustrates a state in which the contact plug 804 at the lower layer and the hole pattern 803 at the upper layer are arrayed without misalignment.
[0050] FIG. 9 illustrates an SEM image obtained upon imaging a region including the hole pattern 803 of FIG. 8 from the above by using the scanning electron microscope device 700 , and the upper layer 801 of FIG. 8 is imaged as a region 901 , the contact plug 804 at the lower layer is imaged as a region 902 , and an outline of the hole pattern 803 is imaged as a pattern 903 . Hereinafter, the contact plug 804 which is observed through the hole pattern 803 and formed at the lower layer 802 in the SEM image obtained by imaging with the scanning electron microscope device 700 is called the lower layer pattern 902 . The SEM image corresponding to the hole pattern 803 created at the upper layer 801 may simply be called the upper layer pattern 903 .
[0051] FIG. 10 is a schematic cross-sectional view with a simplified partial cross section of a semiconductor device having a contact plug 1004 formed at a lower layer 1002 and a hole pattern 1003 formed at an upper layer 1001 , illustrating a state in which the contact plug 1004 at the lower layer and the hole pattern 1003 at the upper layer are being misaligned with each other.
[0052] FIG. 11 illustrates an SEM image of a region 1101 corresponding to a surface of the upper layer 1001 obtained by imaging a region including the hole pattern 1003 of FIG. 10 from the above by using the scanning electron microscope device 700 , and with respect to an outline 1103 of the hole pattern 1003 , a region 1102 of the contact plug 1004 at the lower layer is misaligned, and the lower layer 1002 is imaged as a region 1104 which is darkest in FIG. 11 .
[0053] The overlay measurement is intended to find misalignment between the hole pattern 803 ( 1003 ) formed at the upper layer 801 ( 1001 ) and the contact plug 804 ( 1004 ) formed at the lower layer 802 ( 1002 ). The captured images are processed to measure the misalignment between the lower layer pattern 902 ( 1002 ) in the SEM image illustrated in FIG. 9 ( FIG. 11 ) corresponding to the contact plug 804 ( 1004 ) formed at the lower layer 802 ( 1002 ) in the sectional view of FIG. 8 ( FIG. 10 ) and the hole pattern expressed by the upper layer pattern 903 ( 1103 ) in the SEM image illustrated in FIG. 9 ( FIG. 11 ) corresponding to the hole pattern 803 ( 1003 ) formed at the upper layer 801 ( 1001 ) in the sectional view of FIG. 8 ( FIG. 10 ).
[0054] The pattern 804 or 1004 formed at the lower layer 802 or 1002 has been described as the contact plug in FIG. 8 and FIG. 10 , but the pattern formed at the lower layer 802 or 1002 is not limited to the contact plug, and a different pattern is also permitted. Moreover, the hole pattern 903 or 1103 is illustrated in a circle in FIG. 9 and FIG. 11 , but a shape of the hole in the image is not limited to the circle.
[0055] In the overlay measurement performed through comparison between the reference image and the measurement image described in the present embodiment, an image in a state in which the two patterns targeted for the overlay measurement as in FIG. 9 , that is, the upper layer pattern 903 corresponding to the hole pattern 803 and the lower layer pattern 902 corresponding to the contact plug 804 in the aforementioned example are aligned is provided as a reference image. The reference image may be created by imaging one or a plurality of places through user selection. In the overlay measurement performed through comparison between a reference image and a measurement image described below by referring FIG. 12 , the region 902 and the outline 903 of the reference image are used as hole and outline information of the region on the surface of the upper layer, and the region 902 and the outline 903 are used as outline and region information of a hole bottom of the hole pattern 803 serving as a surface of boundary with the lower layer pattern.
[0056] FIG. 12 shows a flow of overlay measurement processing performed through comparison between the reference image and the measurement image in the SEM image of the semiconductor wafer 707 obtained by using the scanning electron microscope device 700 . First, patterns targeted for the overlay measurement are extracted respectively from a reference image 1201 (corresponding to the image described in FIG. 9 ) including a lower layer pattern image 12011 and a measurement image 1202 (corresponding to the image described in FIG. 11 ) including a lower layer pattern image 12021 targeted for the overlay measurement and a lower layer image 12022 (S 1251 ) to create upper layer pattern images 1211 and lower layer pattern images 1212 . As the upper layer pattern images 1211 , a reference image 1203 including a hole pattern image 1204 and a measurement image 1205 including a hole pattern image 1206 are created. As the lower layer pattern images 1212 , a reference image 1207 including a contact plug pattern image 1208 corresponding to the lower layer pattern image 12011 and a measurement image 1209 including a contact plug pattern image 1210 corresponding to the lower layer pattern image 12021 are created. Extraction of the upper layer pattern images 1211 and the lower layer pattern images 1212 can be performed by a technique of region division in image processing, such as region division based on a gray level.
[0057] Next, image positional alignment between the reference image 1203 and the measurement image 1205 is performed in the created upper layer pattern images 1211 (S 1252 ), and an amount (ΔUx, ΔUy) of the positional misalignment between the hole pattern image 1204 in the reference image 1204 included in the upper layer pattern images 1211 and the hole pattern image 1206 in the measurement image 1205 therein is obtained (S 1254 ).
[0058] FIG. 12 illustrates the extracted patterns by binary images, but accuracy in the image positional alignment performed in step S 1252 can be improved in some cases by using a different image obtained by performing filtering processing on an original image of only regions of the hole pattern images 1204 and 1206 in the upper layer pattern images 1211 corresponding to the bole patterns 803 and 1003 and regions of the contact plug pattern images 1208 and 1210 in the lower layer pattern image 1212 corresponding to the contact plugs 804 and 1004 or an original image of only corresponding regions of the upper layer pattern images 1211 and the lower layer pattern images 1212 .
[0059] For the lower layer pattern images 1212 , similarly to a case of the upper layer pattern images 1211 , image positional alignment between the reference image 1207 and the measurement image 1209 is performed (S 1253 ), and an amount (ΔLx, ΔLy) of positional misalignment between the contact plug pattern image 1208 in the reference image 1207 of the lower layer pattern images 1212 and the contact plug pattern image 1210 in the measurement image 1209 thereof is obtained (S 1255 ). Finally, using results obtained in S 1254 and 1255 , an overlay amount (Δx, Δy) is calculated (S 1256 ).
[0060] The above method makes it possible to relatively measure how much positional relationship between the two patterns of the upper layer and the lower layer in the measurement image is misaligned with respect to positional relationship between the two patterns of the upper layer and the lower layer in the reference image.
[0061] The description in FIG. 12 refers to a case where the image has one pattern, but the image may have a plurality of patterns. In a case where the image has a plurality of patterns, the overlay amount illustrated in FIG. 12 can be calculated on an individual pattern basis, and then an average value of the calculated amounts may be obtained.
[0062] Another possible method is a method of collectively processing a plurality of patterns in an image. Specifically, a reference image and a measurement image including a plurality of patterns in upper layer pattern images are compared to each other, and an upper layer pattern positional misalignment amount is obtained. A reference image and a measurement image including a plurality of patterns in lower layer pattern images are compared to each other, and a lower layer pattern positional misalignment amount is obtained. Based on the obtained upper layer pattern positional misalignment amount and the obtained lower layer pattern positional misalignment amount, an overlay amount can be calculated.
[0063] FIG. 13 illustrates procedures of processing of displaying results of the overlay measurement of FIG. 12 . Differentiation filter processing is performed on the reference image 1201 and the measurement image 1202 targeted for the measurement, both illustrated in FIG. 12 (S 1351 ) to generate a differential reference image 1301 including an upper layer hole pattern 1302 (also a lower layer contact plug pattern image 1302 ) and a differential measurement image 1303 including an upper layer hole pattern 1304 and a lower layer contact plug pattern image 1305 . For example, a Sobel filter is used as a differential filter.
[0064] Next, the differential reference image 1301 is colored in color 1 (S 1352 ), and the differential measurement image 1303 is colored in color 2 (S 1353 ). The color 1 and the color 2 are different from each other, and colors providing excellent color contrast effect are selected. More specifically, the color 1 and the color 2 are in complementary relationship, or only R is used for the color 1 and a mixture of G and B is used for the color 2 in an RGB color model, or a mixture of G and B is used for the color 1 and only R is used for the color 2 . In the coloring of the differential reference image 1301 , a value obtained by subjecting a gray level of the differential reference image 1301 to linear conversion or non-linear conversion is set as an intensity of the color 1 . The same applies to the coloring of the differential measurement image 1303 .
[0065] Next, image positional correction of the colored differential reference image 1301 is performed by using the lower layer pattern positional misalignment amount (ΔLx, ΔLy) calculated in step S 1255 in the process flow of FIG. 12 (S 1354 ), and position of the lower layer contact plug pattern image 1302 (also corresponds to the upper layer hole pattern image) of the differential reference image 1301 is aligned with position of the lower layer contact plug pattern image 1305 of the differential measurement image 1303 .
[0066] Finally, an image obtained by coloring the differential reference image 1301 in S 1352 and subjecting the colored differential reference image 1301 to the positional correction in S 1354 is superposed on an image obtained by coloring the differential measurement image 1303 in S 1353 (S 1356 ) to obtain a display image 1310 . The display image 1310 is obtained by emphasizing a pattern edge by the differential filter processing (S 1351 ) and mutually superposing the reference image and the measurement image colored in the different colors in S 1352 and S 1353 . The display image 1310 is displayed on a screen of the display terminal 756 .
[0067] Numeral 1311 in the display image 1310 represents an outline of the lower layer contact plug pattern image 1302 in the differential reference image 1301 (also an outline of the upper layer hole pattern image 1302 in the differential reference image 1301 ), numeral 1312 represents an outline of the lower layer contact plug pattern image 1305 in the differential measurement image 1303 , and numeral 1313 represents an outline of the upper layer hole pattern image 1304 in the differential measurement image 1303 . The display image 1310 makes it possible to confirm that the positional alignment between the lower layer contact plug pattern image 1302 in the differential reference image 1301 and the lower layer contact plug pattern image 1305 in the differential measurement image 1303 is properly performed.
[0068] For better visibility on the display image 1310 , the outline 1311 of the lower layer contact plug pattern image 1302 in the differential reference image 1301 and the outline 1312 of the lower layer contact plug pattern image 1305 in the differential measurement image 1303 are drawn with slight misalignment therebetween. On an actual image, the outlines 1311 , 1312 , and 1313 in the display image 1310 are not thin lines as illustrated in the figure, but wide lines which are brightest at a pattern edge position and become darker with a distance therefrom. In accordance with the way of coloring described above, transmittance is ensured at a portion where any of the outlines 1311 , 1312 , and 1313 are superposed on each other, thus making it easy to confirm a superposition state of the line patterns with a wide gray scale.
[0069] In contrast, to confirm a result of the positional alignment between the upper layer hole pattern image 1302 in the differential reference image 1301 and the upper layer hole pattern image 1304 in the differential measurement image 1303 , by using the upper layer pattern positional misalignment amount (ΔUx, ΔUy) calculated in S 1254 , the positional alignment is performed on the differential reference image 1301 colored in S 1352 (S 1355 ), and then after position of the upper layer hole pattern image 1302 in the differential reference image 1301 is aligned with position of the upper layer hole pattern image 1304 in the differential measurement image 1303 , superposition on the differential measurement image 1303 colored in S 1353 is performed (S 1357 ) to obtain a display image 1315 . The display image 1315 is displayed on the screen of the display terminal 756 .
[0070] The display image 1315 is an image obtained by emphasizing a pattern edge through the differential filter processing (S 1351 ) and superposing the differential reference image 1301 and the differential measurement image 1303 colored in the different colors in 1352 or 1353 .
[0071] Numeral 1314 in the display image 1315 represents an outline of the upper layer hole pattern image 1302 in the differential reference image 1301 (also an outline of the lower layer contact plug pattern image), numeral 1312 represents an outline of the lower layer contact plug pattern image 1305 in the differential measurement image 1303 , and numeral 1313 represents an outline of the upper layer hole pattern image 1304 in the differential measurement image 1303 . The display image 1315 makes it possible to confirm that the positional alignment between the upper layer hole pattern image 1302 in the differential reference image 1301 and the upper layer hole pattern image 1304 in the differential measurement image 1303 is performed properly.
[0072] For better visibility on the display image 1315 , the outline 1314 of the upper layer hole pattern image 1302 in the differential reference image 1301 and the outline 1313 of the upper layer hole pattern 1304 in the differential measured image 1303 are drawn with slight misalignment therebetween.
[0073] Displaying the display image 1310 and the display image 1315 on the screen of the display terminal 756 for the confirmation makes it possible to recognize whether or not the positional alignment has been executed properly. If the positional alignment has been executed properly, it can be said that the upper layer pattern positional misalignment amount (ΔUx, ΔUy) and the lower layer pattern positional misalignment amount (ΔLx, ΔLy) are calculated properly and the overlay value calculated in S 1256 of FIG. 12 is reliable. On the contrary, if there is any abnormal misalignment between the outlines (pattern edges) 1311 , 1312 , and 1313 or between the outlines 1312 , 1313 , and 1314 in the display image 1310 and the display image 1315 , the image positional alignment performed in 1252 and S 1253 of FIG. 12 results in failure, and the overlay amount calculated in S 1256 includes a mistake.
[0074] In the flow of the processing described in FIG. 13 , the image positional correction is performed in S 1354 and 1355 after the coloring performed in S 1352 , but order of the aforementioned operations may be reversed so that the coloring may be performed in S 1352 after the image positional correction performed in S 1354 and 1355 .
[0075] The flow of the processing described in FIG. 13 has been described, referring to procedures of performing the positional correction of the differential reference image 1301 and superposing the resulting differential reference image 1301 on the differential measurement image 1303 to obtain the display images 1310 and 1315 , but the differential measurement image 1303 may be subjected to positional correction and superposed on the differential reference image 1301 to obtain display images.
[0076] FIG. 14 illustrates a modified example of the procedures of the processing of displaying the results of the overlay measurement illustrated in FIG. 13 . As a result of subjecting a reference image 1201 and a measurement image 1202 to differential filter processing (S 1403 ) as described in S 1351 of FIG. 13 , as schematically illustrated on images 1411 and 1413 , in addition to patterns 1412 and 1414 targeted for measurement, a portion 1415 with a high differential value may appear. Creating a display image including such a portion deteriorates visibility, so that on the reference image 1201 , an image 1421 obtained by extracting an upper layer pattern of the reference image 1201 in a binary manner is subjected to inversion processing (S 1401 ) to thereby obtain an upper layer pattern mask image 1422 . A white portion 1423 of the upper layer pattern mask image 1422 is defined as 1 and a black portion 1424 thereof is defined as 0. The image 1411 can be subjected to mask processing (S 1403 ) by the upper layer pattern mask image 1422 to thereby erase the portion with the high differential value appearing in addition to the patterns targeted for the measurement and obtain a differential image 1425 corresponding to the image 1302 of FIG. 13 .
[0077] Similarly, on a measurement image 1202 , an image 1431 obtained by extracting an upper layer pattern of the measurement image 1202 in a binary manner is subjected to inversion processing (S 1402 ) to thereby obtain an upper layer pattern mask image 1432 . A white portion 1433 of the upper layer pattern mask image 1432 is defined as 1, and a black portion 1434 thereof is defined as 0. With the upper layer pattern mask image 1432 , an image 1413 obtained by subjecting the measurement image 1202 to differential filter processing in S 1351 can be subjected to mask processing (S 1404 ) to thereby obtain a differential image 1435 corresponding to the image 1303 of FIG. 13 with the erased portion with the high differential value appearing in addition to the patterns targeted for the measurement.
[0078] Processing thereafter permits subjecting the image 1425 to the processing in and after the coloring processing S 1352 illustrated in FIG. 13 and subjecting the image 1435 to the processing in and after the coloring processing S 1353 to thereby obtain display images 1310 and 1315 having a 0 value in regions other than measurement regions of the reference image 1201 and the measurement image 1202 . In such a case, the regions other than the measurement regions are black, thus making it possible to clearly display the images, such as the hole patterns 803 and 1003 and the contact plugs 804 and 1004 , at portions targeted for the measurement. A value of a portion to be masked is not limited to 0 and it can be replaced with a different value and a different color.
[0079] FIG. 15 illustrates a state in which the display images 1310 and 1315 described with reference to FIG. 13 are superposed on each other. The image 1302 (an outline on the hole pattern image) in the differential reference image 1301 described in FIG. 13 is used, in a state illustrated in FIG. 15 , as the pattern 1314 for positional alignment with the upper layer pattern 1313 of the differential measurement image 1303 and as the pattern 1311 for positional alignment with the lower layer pattern 1312 of the differential measurement image 1303 . Thus, as a result of defining a representative position of the hole pattern image 1302 of the differential reference image 1301 , a change in a representative position 1502 (a central position of a pattern 1314 in the example illustrated in FIG. 15 ) of the hole pattern of the differential reference image 1301 obtained upon the positional alignment with the upper layer pattern of the differential measurement image 1303 and a representative position 1501 (a central position of the pattern 1311 in the example illustrated in FIG. 15 ) of the hole pattern of the differential reference image 1301 obtained upon the positional alignment with the lower layer pattern of the differential measurement image 1303 is directly provided as an overlay amount. Therefore, a vector display 1601 obtained by linking together the aforementioned points 1501 and 1502 as illustrated in FIG. 16 can display an amount and a direction of the aforementioned misalignment.
[0080] A possible way of defining the representative position of the hole pattern of the reference image includes, for example, pixel value weighing of the reference image subjected to differential filter processing and masking. The representative position may be a position which corresponds to a partial region of the image and which is fixed relatively to coordinates of a measurement window set for performing the overlay measurement processing. However, the representative position is not limited to the aforementioned position and may be defined as desired.
[0081] FIG. 17 illustrates superposition of the measurement image 1202 itself, instead of the differential measurement image subjected to the differential filter processing and the coloring processing, on the display image 1310 of FIG. 13 . This makes it possible to confirm with which position the pattern edge 1311 of the reference image 1201 has been aligned on the original image of the measurement image 1202 on which a lower layer pattern image 12021 and a lower layer image 12022 are displayed. In such a case, for the measurement image 1202 superposed in the image superposition step S 1356 , gray values of the original measurement image may be evenly assigned to R, G, and B values, and as intensity of saturation of a specific color, the assignment may be achieved by subjecting gray values of the reference image subjected to the differential filter processing to linear conversion or non-linear conversion.
[0082] FIG. 18 illustrates superposition of the reference image 1201 itself on which a lower layer pattern image 12011 whose position is aligned with the pattern edge 1311 , instead of the differential reference image subjected to the differential filtering processing and the coloring processing, on the display image 1310 of FIG. 13 . The same substitute display method is also applicable to the display image 1315 of FIG. 13 .
[0083] Switching of display elements makes it easier to confirm the results of the overlay measurement. The display elements here in FIG. 13 refer to seven elements including: (1) the differential reference image obtained after the image positional correction processing (S 1354 ); (2) the differential reference image obtained after the image positional correction processing (S 1355 ); (3) the differential measurement image obtained after the coloring processing (S 1353 ); (4) the vector display 1601 of FIG. 16 ; (5) the differential reference image subjected to the positional correction (S 1354 ) with the lower layer pattern positional misalignment amount (ΔLx, ΔLy); (6) the differential reference image subjected to the positional correction (S 1355 ) with the upper layer pattern positional misalignment amount (ΔUx, ΔUy); and (7) the measurement image. Sequentially changing at least any desired one of the display elements, a superposition thereof, or a combination of superposition thereof makes it easier to confirm the results of the overlay measurement. For example, constantly displaying (3) the differential measurement image obtained after the coloring processing (S 1353 ) and performing confirmation while switching between display and non-display of (1) the reference image obtained after the image positional correction processing (S 1354 ) makes it possible to easily evaluate whether or not position of the lower layer pattern 902 of the reference image is properly aligned with position of the lower layer pattern 1102 of the measurement image.
[0084] The method of performing the image positional correction on the reference image based on the lower layer pattern positional misalignment amount or the upper layer pattern positional misalignment amount to perform superposed display of the images has been described above, but it is obvious that positional correction can be performed on the measurement image based on the lower layer pattern positional misalignment amount or the upper layer pattern positional misalignment amount to perform superposed display of the images. In such a case, it should be noted that the lower layer pattern positional misalignment amount or the upper layer pattern positional misalignment amount is reversely directed between a case where the reference image is subjected to the image positional correction and a case where the measurement image is subjected to the image positional correction.
[0085] FIG. 19 illustrates a flow of processing performed for carrying out, with the overlay measurement device 1000 illustrated in FIG. 7 , the method of displaying the results of the overlay measurement described with reference to FIG. 12 to FIG. 18 .
[0086] First, a pattern serving as a reference is imaged with the SEM to acquire a reference image, and the obtained image is then stored as the reference image 1201 into a storage region of the image processing section 752 (S 1901 ). Next, the semiconductor wafer 707 having a circuit pattern targeted for overlay measurement is loaded onto the scanning electron microscope device 700 of the overlay measurement device 1000 illustrated in FIG. 7 , and is then placed on the stage 706 (S 1902 ). After the loading of the semiconductor wafer 707 , the stage 706 is controlled through the stage controller 755 by the overall control section 753 of the processing and control section 750 , and the stage 706 is moved in a manner such that a section of the measurement patterns on the semiconductor wafer 707 without any misalignment falls in an observation visual field of the irradiation optical system 710 of the scanning electron microscope device 700 (S 1903 ).
[0087] Next, under control of the deflection coils 704 by the electron optical system control section 754 , a region (region targeted for the measurement) including the pattern targeted for the overlay measurement and formed on the semiconductor wafer 707 is scanned by the electron beam 701 . A signal obtained by detecting, with the detector 708 , the secondary electron generated from the region targeted for the measurement is converted in a digital signal by the A/D converter 709 , is inputted as a photographed image into the image processing section 710 , and is stored into a memory (not illustrated) of the image processing section 710 (S 1904 ).
[0088] Subsequently, the reference image 1201 and the measurement image 1202 are read from the memory of the image processing section 710 , and the overlay (Δx, Δy) illustrated in 1212 is calculated at a calculation section (not illustrated) of the image processing section 710 in accordance with the processing flow illustrated in FIG. 12 (S 1905 ). After ending of the calculation processing, the upper pattern positional misalignment amount (ΔUx, ΔUy) illustrated in S 1254 of FIG. 12 , the lower layer pattern positional misalignment amount (ΔLx, ΔLy) illustrated in S 1255 and the overlay amount (Δx, Δy) illustrated in S 1256 are stored into the memory of the image processing section 710 .
[0089] For display of the results, the reference image 1201 , the measurement image 1202 , the upper layer pattern positional misalignment amount 1210 , and the lower layer pattern positional misalignment amount 1211 are read, the processing flow illustrated in FIG. 13 is executed at the calculation section of the image processing section 710 , and the display images 1310 and 1315 are calculated and stored into the memory of the image processing section 710 (S 1906 ). The calculated display images 1310 and 1315 are outputted from the image processing section 710 to the overall control section 713 , which displays the display image 1310 or the display image 1315 at the display terminal 714 (S 1907 ). Steps S 1903 to S 1907 are executed for all measurement points.
[0090] To partially display only the measurement region at the display terminal 714 , upon execution of the processing illustrated in FIG. 12 , the upper layer pattern reference image 1204 and the upper layer pattern measurement image 1205 are further stored into the memory of the image processing section 710 . In the display of the results, the reference image 1201 , the measurement image 1202 , the upper layer pattern reference image 1204 , the upper layer measurement image 1205 , the upper layer pattern positional misalignment amount 1210 , and the lower layer pattern positional misalignment amount 1211 are read. At the calculation section of the image processing section 710 , the processing flow illustrated in FIG. 13 and FIG. 14 is executed using the read information, and the display image 1310 or the display image 1315 is calculated and stored into the memory of the image processing section 710 . The calculated display image 1310 or 1315 is outputted from the image processing section 710 to the overall control section 713 , which displays the display image 1310 or the display image 1315 at the display terminal 714 .
[0091] For the vector display illustrated in FIG. 16 , the representative position of the hole pattern of the reference image is calculated at the calculation section of the image processing section 710 described above, and is stored into the memory of the image processing section 710 in correspondence with the reference image. Upon the overlay measurement, the aforementioned overlay amount Δx, Δy and the representative position of the reference image which are stored in the memory of the image processing section 710 are read by the overall control section 713 , a vector display of the overlay amount focused on the representative position is generated at a calculation section (not illustrated) of the overall control section 713 , and is stored into a memory (not illustrated) of the overall control section 713 and displayed at the display terminal 714 .
[0092] In the embodiment described above, the reference image is previously recorded, but may be acquired each time from the semiconductor wafer targeted for the measurement.
[0093] FIG. 20 illustrates a detailed example of the display provided at the display terminal 714 . An ID 20001 refers to an identification number of a reference image 2003 , a measurement image 2004 , or a resulting measurement image 2005 , and corresponds to an overlay measurement section on the wafer. Numeral 2002 represents a numerical value of overlay measurement results. FIG. 20 also displays the reference image 2003 and the measurement image 2004 together with the resulting measurement image 2005 , but may not display either or both of the aforementioned images when not necessary. Contents of the display of the resulting measurement image 2005 is switched by measurement results display switching 2006 . The measurement results display switching 2006 includes switches respectively located aside of “Image comparison results”, “Vector display”, “Reference image”, “Measurement image”, “Reference image mask”, and “Measurement image mask”, with black circles each indicating that the corresponding item has been selected and white circles each indicating that the corresponding item has not been selected. Switching between Selected and Not selected is performed through, for example, clicking performed on the screen. Hereinafter, each of the items displayed in the measurement results display switching 2006 will be described.
[0094] In the item “Image comparison results”, in a case where the upper layer is selected, based on the positional misalignment amount of the upper layer pattern 1210 , the reference image is subjected to positional correction and superposed on the measurement image to be displayed as the resulting measurement image 2005 , and in a case where the lower layer is selected, based on the positional misalignment amount of the lower layer pattern 1211 , the reference image is subjected to positional correction and superposed on the measurement image to be displayed as the resulting measurement image 2005 , and either or both of the upper layer and the lower layer can be selected. The display image 1315 is a display example when only the upper layer is selected, and the display image 1310 is a display example when only the lower layer is selected.
[0095] The item “Vector display” is an item for selecting whether or not to superpose the vector display illustrated in FIG. 16 on the resulting measurement image 2005 .
[0096] The item “Reference image” is an item for selecting whether the reference image to be superposed on the resulting measurement image 2005 is provided as an original image or a colored edge filter image. In a case where the both are not selected, the reference image is not superposed on the resulting measurement image 2005 .
[0097] The item “Measurement image” is an item for selecting whether the measurement image to be superposed on the resulting measurement image 2005 is provided as an original image or a colored edge filter image. In a case where the both are not selected, the measurement image is not superposed on the resulting measurement image 2005 .
[0098] The item “Reference image mask” is an item for selecting whether or not to mask, by the upper layer pattern reference image 1204 , the reference image to be superposed on the resulting measurement image 2005 .
[0099] The item “Measurement image mask” is an item for selecting whether or not to mask, by the upper layer pattern measurement image 1204 , the measurement image to be superposed on the resulting measurement image 2005 .
[0100] In accordance with input of the measurement results display switching described above, the overall control section 713 reads the information stored in the memory of the image processing section 710 or the memory of the overall control section 713 , updates display contents of the resulting measurement image 2005 , and outputs the updated contents to the display terminal 714 .
[0101] As described above, with the present Example, in the overlay measurement using the SEM image and using the product circuit of the semiconductor device through comparison between the reference image and the measurement image, when the reference image or the measurement image is displayed in a superposed manner with misalignment in accordance with the obtained overlay amount, it is possible to improve visibility of the superposed display.
REFERENCE SIGNS LIST
[0000]
700 . . . Scanning electron microscope device,
701 . . . Electron beam,
702 . . . Electron gun,
703 . . . Capacitor lens,
704 . . . Deflection coil,
705 . . . Objective lens,
706 . . . Stage,
707 . . . Wafer,
708 . . . Detector,
750 . . . Processing and control section,
751 . . . A/D converter,
752 . . . Image processing section,
753 . . . Overall control section,
754 . . . Electron optical system control section,
755 . . . Stage controller,
756 . . . Display terminal,
1000 . . . Overlay measurement device. | To address the problem in which when measuring the overlay of patterns formed on upper and lower layers of a semiconductor pattern by comparing a reference image and measurement image obtained through imaging by an SEM, the contrast of the SEM image of the pattern of the lower layer is low relative to that of the SEM image of the pattern of the upper layer and alignment state verification is difficult even if the reference image and measurement image are superposed on the basis of measurement results, the present invention determines the amount of positional displacement of patterns of an object of overlay measurement from a reference image and measurement image obtained through imaging by an SEM, carries out differential processing on the reference image and measurement image, aligns the reference image and measurement image that have been subjected to differential processing on the basis of the positional displacement amount determined previously, expresses the gradation values of the aligned differential reference image and differential measurement image as brightnesses of colors that differ for each image, superposes the images, and displays the superposed images along with the determined positional displacement amount. | 6 |
FIELD OF THE INVENTION
[0001] The present invention relates to a process and apparatus for separating a gaseous mixture within a rectification column by cryogenic rectification to produce a nitrogen product in which an oxygen-enriched liquid composed of a column bottoms is vaporized against condensing a nitrogen containing column overhead to produce reflux for the rectification column. More particularly, the present invention relates to such a process and apparatus in which the oxygen-enriched liquid is successively vaporized and a nitrogen-rich vapor phase produced by the successive vaporization of the oxygen-enriched liquid is condensed and then reintroduced into the column to enhance nitrogen recovery.
BACKGROUND OF THE INVENTION
[0002] Nitrogen can be separated from gaseous mixtures that comprise nitrogen and oxygen, for example, air, by cryogenic rectification. Typically, a compressed and purified air stream is cooled to a temperature suitable for its rectification and then rectified within a rectification column to produce a nitrogen-rich vapor as column overhead and an oxygen-enriched column bottoms. Reflux for the column is produced by condensing some of the nitrogen-rich vapor. This condensation is effectuated through indirect heat exchange of a stream of the nitrogen-rich vapor and a stream of the oxygen-enriched column bottoms. Part of the liquid can be taken as a product.
[0003] The resultant vaporization of the oxygen-enriched column bottoms produces a stream that is referred to as a waste stream. The waste stream and a nitrogen product stream are passed through a main heat exchanger in order to cool the incoming compressed and purified air. Refrigeration can be supplied by partially heating the waste stream within the main heat exchanger, passing the waste stream through a turboexpander and then subsequently warming the waste stream within the main heat exchanger.
[0004] In general, the performance of the condenser used to exchange heat between oxygen-enriched liquid and the nitrogen-rich vapor is inefficient. Excess temperature difference exists between the oxygen-enriched liquid stream that is to be vaporized and the overhead nitrogen that is to be condensed. As a consequence, additional compression power is consumed by the process due in large part to the heat transfer within the condenser. Additionally, excess compositional gradients exist near the bottom of the rectification column. In particular, rapid compositional changes occur over few stages. Such steep compositional changes correspond to substantial thermodynamic irreversibility that translates into lost work. In the prior art, substantial efforts have focused primarily on condenser operation and column recovery.
[0005] U.S. Pat. No. 4,867,773 and U.S. Pat. No. 4,872,893 detail similar processes that involve a single column nitrogen rectification process in which at least a portion of the evaporated oxygen-rich bottoms is warmed, compressed and recycled to the column. The recycled stream is fed to a point lower than the feed air. The effect of the modification allows the overhead condenser to operate more efficiently to increase nitrogen recovery.
[0006] U.S. Pat. No. 4,883,519 illustrates another single column nitrogen rectification process wherein the overhead nitrogen is condensed by way of two heat exchangers. In this process the oxygen-rich column bottoms stream is depressurized to a first pressure and partially vaporized. The resulting vapor is recycled to the main air compressor. The remaining oxygen-rich liquid is further depressurized and directed to a second lower pressure heat exchanger where it is substantially vaporized. At least a portion of the resulting vapor is directed to a turbine expander for refrigeration production.
[0007] U.S. Pat. No. 4,927,441 discloses another single column nitrogen process that is similar to that disclosed in U.S. Pat. No. 4,883,519. In this arrangement, the oxygen-rich column bottoms is depressurized to a first pressure and then introduced into a separation vessel which incorporates a small mass-transfer section containing mass-transfer elements such as a packing. The mass-transfer column section serves to further enrich the oxygen content of the stream prior to its depressurization and introduction into a second heat exchanger. The advantage of this arrangement is that the overhead produced in the mass-transfer section has very nearly the composition of air and thus, can be recycled by way of the main air compressor, without associated compositional mixing losses.
[0008] U.S. Pat. No. 5,711,167 discloses a single column nitrogen process in which two overhead condensers are used to generate reflux to the rectification column by successive vaporizations of oxygen-enriched liquid. In a first partial vaporization of the oxygen-enriched liquid conducted in one of the two overhead condensers, the resulting vapor is compressed in a cold compressor and redirected back to the base of the rectification column. The oxygen-rich waste produced from a second partial vaporization of the oxygen-enriched liquid, conducted in the second condenser, is warmed and expanded prior to venting. At least a portion of the shaft work of expansion is directed to the cold compression.
[0009] U.S. Pat. No. 5,899,093 details a process in which the oxygen enriched column bottoms is first partially depressurized and introduced into a dephlegmator-type condenser. The oxygen-rich bottoms, produced in the condenser, is separated into a nitrogen-rich gas which is recycled by way of gas compression within an air compressor. The further oxygen-rich remaining fluid is further depressurized and used to condense an additional portion of the overhead nitrogen from the column. The further oxygen enriched remaining fluid is further depressurized to condense an additional portion of the overhead nitrogen from the column. The nitrogen fraction resulting from the first partial vaporization is recycled to a gas compression and then to the column.
[0010] U.S. Pat. No. 5,934,106 and U.S. Pat. No. 5,868,006 disclose a single column nitrogen generator in which overhead nitrogen is condensed against two streams derived from the column system. A first nitrogen enriched air-like liquid stream is evaporated and recompressed back to the column. A second oxygen-rich column bottoms stream is extracted from the column and also evaporated. The second evaporated fraction is warmed and then expanded. The work of expansion provides the shaft work required for the cold compression of the first recycled stream.
[0011] As will be discussed, the present invention involves a process for recovering nitrogen-rich vapor by the cryogenic rectification of air or other oxygen and nitrogen containing gas within a rectification column in which a nitrogen-rich liquid condensate produced in the course of sequential vaporizations of an oxygen-enriched liquid stream, made-up at least in part from liquid column bottoms, is introduced into the rectification column to increase production of the nitrogen-rich vapor in an energy efficient and cost effective manner.
SUMMARY OF THE INVENTION
[0012] The present invention provides a method of separating a gaseous mixture comprising nitrogen and oxygen to produce a nitrogen product. In accordance with the method, a purified, pressurized and cooled gaseous stream composed of the gaseous mixture is introduced into a rectification column to produce an overhead nitrogen-rich vapor and an oxygen-enriched liquid bottoms. A first oxygen-enriched liquid stream that is at least in part composed of the oxygen-enriched liquid bottoms is depressurized and then partially vaporized within a first heat exchanger. A vapor phase is disengaged from a liquid phase that is formed by the partial vaporization of the first oxygen-enriched liquid stream. A second oxygen-enriched liquid stream composed at least in part of the liquid phase is depressurized and is then partially vaporized through indirect heat exchange with at least a portion of a vapor phase stream composed of the vapor phase within a second heat exchanger. This substantially condenses the vapor phase stream to form a nitrogen-rich liquid stream.
[0013] A first part of a column overhead nitrogen-rich stream that is composed of the overhead nitrogen-rich vapor is condensed in the first heat exchanger and a second part of the column overhead nitrogen-rich stream is condensed in a third heat exchanger. The condensation of the second part of the column overhead nitrogen-rich stream is conducted through indirect heat exchange with the second oxygen-enriched stream after the partial vaporization thereof, thereby further vaporizing the second oxygen-enriched stream. At least part of the column overhead nitrogen-rich stream after having been condensed is returned to the rectification column as reflux.
[0014] At least part of the nitrogen-rich liquid stream is then introduced into the rectification column, above the purified, pressurized and cooled stream. A product nitrogen stream is produced from part of the nitrogen-rich vapor.
[0015] The first oxygen-enriched liquid stream can be subcooled through indirect heat exchange with the nitrogen product stream and a waste stream composed of a vapor fraction of the second oxygen-enriched liquid stream after having been further vaporized. A compressed and purified stream composed of the gaseous mixture can be cooled by indirect heat exchange with the nitrogen product stream and the waste stream after having subcooled the oxygen-enriched stream and if present, the second part of the nitrogen-rich vapor stream prior to its compression. The cooling of the compressed and purified stream thereby forms at least a portion of the purified, pressurized and cooled stream.
[0016] In a specific embodiment of the present invention, a first part of the vapor phase stream can be substantially condensed within the second heat exchanger to form the nitrogen-rich liquid stream and a second part of the vapor phase stream can be warmed, compressed and cooled and recycled back to the rectification column. The cooling and the recycling can be accomplished by combining the second part of the vapor phase stream, after having been warmed and compressed, with the compressed and purified stream to form a combined compressed and purified stream. In such embodiment, the combined compressed and purified stream is cooled by the nitrogen product stream, the waste stream and the second part of the nitrogen-rich vapor stream. As such, the second part of the vapor phase stream is cooled and recycled back to the rectification column by being combined with the compressed and purified stream.
[0017] Preferably, the waste stream and the nitrogen product stream and if present, the second part of the nitrogen-rich vapor stream prior to its compression, all indirectly exchange heat with the compressed and purified stream within a main heat exchanger. The waste stream can be partially warmed within the main heat exchanger and is then expanded with the performance of work to generate an exhaust stream. The exhaust stream is reintroduced into the main heat exchanger and fully warmed to refrigerate the cryogenic rectification process. It is to be noted that the term “partially warmed” as used herein and in the claims means that the waste stream is warmed to a temperature intermediate the temperatures of the warm and cold ends of the main heat exchanger. The term, “fully warmed” as used herein and in the claims means fully warmed to the warm end temperature of the main heat exchanger.
[0018] The pressure of the nitrogen-rich liquid stream can be adjusted after having been substantially condensed and prior to its being introduced into the rectification column. This adjustment can be effectuated by mechanically pumping the nitrogen-rich liquid stream after having been substantially condensed or by expanding the nitrogen-rich liquid stream.
[0019] In another aspect, the present invention provides an apparatus for separating a gaseous mixture comprising nitrogen and oxygen to produce a nitrogen product. In accordance with this aspect of the present invention a rectification column is connected to the main heat exchanger for rectifying a purified, pressurized and cooled stream composed of the gaseous mixture to produce an overhead nitrogen-rich vapor and an oxygen-enriched liquid bottoms.
[0020] A first valve is provided to depressurize a first oxygen-enriched stream composed at least in part of the oxygen-enriched liquid bottoms. A first heat exchanger is connected to the first valve for partially vaporizing the first oxygen-enriched liquid stream and a phase separator is connected to the first heat exchanger for disengaging a vapor phase from a liquid phase formed by the partial vaporization of the first oxygen-enriched stream. A second valve is connected to the phase separator for depressurizing a second oxygen-enriched liquid stream composed at least in part of the liquid phase and a second heat exchanger is connected to the second valve and to the phase separator for partially vaporizing the second oxygen-enriched liquid stream through indirect heat exchange with at least a portion of a vapor phase stream composed of the vapor phase formed by the partial vaporization of the first oxygen-enriched stream. This substantially condenses the vapor phase stream to produce a nitrogen-rich liquid stream. A third heat exchanger is operated in series with the second heat exchanger for further vaporizing the second oxygen-enriched liquid stream.
[0021] The rectification column is connected to the first heat exchanger and the third heat exchanger for purposes of condensing at least a portion of a column overhead nitrogen-rich stream composed of the overhead nitrogen-rich vapor and returning at least a part of the column overhead nitrogen-rich stream after having been condensed to the rectification column as reflux.
[0022] The second heat exchanger is connected to the rectification column for introducing at least part of the nitrogen-rich liquid stream into the rectification column, above the purified, pressurized and cooled stream. A means is provided for extracting a product nitrogen stream formed from part of the overhead nitrogen-rich vapor.
[0023] In a specific embodiment of the present invention, a main heat exchanger can be provided to cool a compressed and purified stream composed of the gaseous mixture and thereby to form the purified, pressurized and cooled stream. In an alternative embodiment, the second heat exchanger can be connected to the phase separator so that a first part of the vapor phase stream is substantially condensed within the second heat exchanger to form the nitrogen-rich liquid stream. A compressor can be connected in flow communication with the phase separator and to the main heat exchanger and the main heat exchanger can be configured so that a second part of the vapor phase stream is warmed within the main heat exchanger and compressed within the compressor. The main heat exchanger in such alternative is also simultaneously in flow communication with the compressed and purified stream and the compressor such that the second part of the vapor phase stream combines with the compressed and purified stream to form a combined compressed and purified stream. In such embodiment the compressed and purified stream is cooled within the main heat exchanger to form the purified, pressurized and cooled stream.
[0024] A subcooler can be connected to the rectification column so that the first oxygen-enriched liquid stream is subcooled through indirect heat exchange with the nitrogen product stream and a waste stream composed of a vapor fraction of the second oxygen-enriched liquid stream after having been further vaporized. The main heat exchanger is also connected to the subcooler and configured so that the compressed and purified air stream is cooled by indirect heat exchange with a nitrogen product stream and the waste stream after having subcooled the first oxygen-enriched stream. If present, the second part of the vapor phase stream also serves to cool the combined compressed and purified air stream.
[0025] Preferably, the main heat exchanger can also be configured such that the waste stream partially warms within the main heat exchanger and an exhaust stream fully warms within the main heat exchanger to refrigerate the apparatus. An expander is connected to the main heat exchanger so that the waste stream after having been partially warmed is expanded within the expander with the performance of work to generate the exhaust stream.
[0026] A pump can be interposed between the second heat exchanger and the rectification column to pressurize the nitrogen-rich liquid stream after having been substantially condensed and prior to its introduction into the rectification column. Alternatively, a third valve can be interposed between the second heat exchanger and the rectification column in order to reduce the pressure of the nitrogen-rich liquid stream after having been substantially condensed and prior to its introduction into the rectification column. The choice of pump or valve will depend upon the gravitation head generated by the elevation difference between the second condenser and the feed location for the nitrogen-rich liquid.
[0027] As is apparent from the description of the present invention in both aspects of its method and apparatus, the return of the nitrogen-rich liquid to the column has the advantage of increasing the production of the nitrogen-rich vapor. It also decreases compositional variations within the bottom of the column to bring the operating line closer to the vapor liquid equilibrium curve thereby generating greater efficiency. This decreases the lost work which translates into decreased compression requirements. The indirect heat exchange between the oxygen-enriched liquid stream and the nitrogen-rich vapor that is used in refluxing the column can be conducted more efficiently than in the prior art due to the three-stage vaporization process that reduces the log mean temperature differences of the streams subjected to indirect heat exchange. This results in a process that is more efficient than those conducted in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] While the specification concludes with claims distinctly pointing out the subject matter that Applicant regards as his invention, it is believed that the invention will be better understood when taken in connection with the accompanying drawings in which:
[0029] FIG. 1 is a schematic, process flow diagram of an apparatus that can be used for carrying out a method in accordance with the present invention; and
[0030] FIG. 2 is an alternative embodiment of FIG. 1 .
DETAILED DESCRIPTION
[0031] With reference to FIG. 1 , an apparatus 1 for carrying out a method in accordance with the present invention is illustrated.
[0032] A compressed and purified stream 10 that is composed of nitrogen and oxygen, for instance, air, is cooled in a main heat exchanger 12 to form a purified, pressurized and cooled stream 13 that is then introduced into a rectification column 14 for separation of the oxygen and nitrogen. Within rectification column 14 , the purified, pressurized and cooled purified stream 13 is rectified and separated into an oxygen-enriched liquid bottoms 16 and an overhead nitrogen-rich vapor 18 . A product stream 20 composed of the nitrogen-rich vapor 18 can be fully warmed within the main heat exchanger 12 against cooling compressed and purified stream 10 .
[0033] Rectification column 14 contains mass-transfer contacting elements such as structured packing or trays that are generally disposed within a bottom region 22 of rectification column 14 and the remaining region 24 situated above bottom region 22 . Typically, rectification column 14 will operate in a pressure range of between about 5 bar absolute and about 12 bar absolute.
[0034] Compressed and purified stream 10 can be formed as a result of unit operations being conducted in another process or as known in the art, can also be formed with the use of a compressor and a pre-purification unit utilizing an adsorbent to absorb water, carbon dioxide and potentially dangerous hydrocarbons that could otherwise freeze-out or accumulate within the cryogenic process. As can be appreciated, a compressor and purification unit could be used in connection with the present invention.
[0035] Compressed and purified stream 10 is introduced into rectification column 14 at about its saturation temperature and as such its introduction initiates the formation of an ascending vapor phase that becomes evermore rich in nitrogen to form the overhead nitrogen-rich vapor 18 . A column overhead nitrogen-rich stream 26 that is composed of the overhead nitrogen-rich vapor is withdrawn from rectification column 14 and is divided into a subsidiary column overhead nitrogen-rich stream 28 and nitrogen product stream 20 . It is understood, however, that nitrogen product stream 20 could be separately withdrawn from rectification column 14 . As will be discussed, subsidiary column overhead nitrogen-rich stream 28 is condensed to produce a reflux stream 29 that is introduced into rectification column 14 to initiate the formation of a descending liquid phase which contacts the ascending vapor phase and becomes evermore rich in oxygen as it descends to form oxygen-enriched liquid 16 as the column bottoms.
[0036] A first oxygen-enriched liquid stream 30 composed of the oxygen-enriched liquid bottoms is optionally subcooled within a subcooling heat exchanger 32 . The resulting subcooled liquid has its pressure reduced by a first valve 34 . First oxygen-enriched liquid stream 30 after passage through first valve 34 is then partially vaporized within a first heat exchanger 36 to form a two-phase stream 38 . The liquid and vapor phases within two-phase stream 38 are separated within a phase separator 40 into a liquid phase 42 and a vapor phase 44 . It is to be noted that oxygen-enriched liquid stream 30 after passage through first heat exchanger 36 can typically have a vapor fraction of between about 10% and about 40% and more preferably, about 30%.
[0037] A second oxygen-enriched liquid stream 46 composed of liquid phase 42 is depressurized with the use of a second valve 48 and then partially vaporized within a second heat exchanger 50 . The pressure drop across second valve 48 will typically be in a range of between about 1.0 and 1.5 bar gauge. Also introduced into second heat exchanger 50 is a vapor phase stream 52 composed of vapor phase 44 that is substantially condensed to form a nitrogen-rich liquid stream 54 . The term “substantially condensed” as used herein and in the claims means a stream having a liquid fraction that will typically exceed about 95% by volume. Moreover, it is to be noted that a typical composition for such nitrogen-rich liquid stream is in the range of 75 to 90% nitrogen.
[0038] The second oxygen-enriched liquid stream 46 after having been partially vaporized within second heat exchanger 50 is then introduced into a third heat exchanger 56 which is shown to operate as a natural thermo-siphon to further vaporize the second oxygen-enriched liquid stream 46 and thereby produce a vapor fraction thereof designated by reference number 58 that is discharged as a waste stream 60 . The second oxygen-enriched liquid stream 46 after such partial vaporization within exchanger 50 will have a vapor fraction in a range of between about 40% and about 60%, more preferably, about 45% to about 50%.
[0039] First portion 62 of column overhead nitrogen-rich stream 28 is condensed within first heat exchanger 36 and a second portion 64 is condensed within third heat exchanger 56 to produce a liquid stream 66 . At least part of combined liquid condensate stream 66 is returned as reflux stream 29 to rectification column 14 . An optional liquid product stream 68 can also be taken and directed to suitable storage (not shown).
[0040] It is understood that first heat exchanger 36 , second heat exchanger 50 and third heat exchanger 56 are typically brazed aluminum heat exchangers. Other exchanger types could be employed, for instance shell and tube type. Given the use of brazed aluminum heat exchangers, first heat exchanger 36 and third heat exchanger 56 could be integrated into a single block. Moreover any number of heat transfer flow configurations could be employed. The heat exchangers may be once-through vaporizers as illustrated or they may be configured for recirculated vaporization. An example, all the exchangers may be configured as thermo-siphons of both natural and pump circulation type. It is understood that exchanger 56 contained within vessel 70 attached to rectification column 14 is a natural thermo-siphon in which boiling flow is induced by gravitational liquid head.
[0041] It is also noted that the distribution of two-phase streams into aluminum heat exchangers often require separate liquid and vapor inlet distribution passages. In order to facilitate such distribution, first oxygen-enriched liquid stream 30 entering first heat exchanger 36 and two-phase stream 46 entering second heat exchanger 50 may be subject to phase separation. Additionally, it is possible that compressed and purified stream 10 would be introduced into rectification column 14 as liquid and vapor phase streams that were produced by partial condensation of compressed and purified stream 10 . In yet another variation, first heat exchanger 36 and second heat exchanger 50 could be used for purposes of subcooling other streams, for example stream 68 prior to its being sent to storage.
[0042] Phase separator 40 can be a simple vapor liquid disengagement vessel. Oxygen enrichment of second oxygen-enriched liquid stream 46 may be increased by inclusion of mass-transfer media such as structured packing or trays. A number of streams may be used to impart additional heat to the base of phase separator 40 to facilitate additional oxygen enrichment if warranted.
[0043] Nitrogen-rich liquid stream 54 is introduced into rectification column 14 above the location of compressed and purified stream 10 . This increases the production of nitrogen-rich vapor and also decreases the compositional gradients within the bottom regions of rectification column 14 . As can be appreciated, the nitrogen content of condensed stream 54 will be higher than that of oxygen enriched liquid 16 and thus, it is introduced at a higher level of rectification column 14 . It is to be noted that not all of the nitrogen-rich liquid stream 54 need be introduced into rectification column 14 . A portion of stream 54 may be: combined with stream 10 , vaporized and warmed and/or recycled, or directed to vessel 70 for purposes of heat exchanger control.
[0044] In order to introduce nitrogen-rich liquid stream 54 into rectification column 14 , in most cases, there will have to be a pressure adjustment to condensed stream 54 by way of a device 72 . If for instance, the pressure of liquid stream 54 is too low for entry into rectification column 14 , device 72 can be a pump. If a pump is used, it may be advantageous to employ a vessel to provide additional liquid residence time. Such a vessel would preferably employ a small vapor vent line (which may be connected to the waste stream as necessary). Alternatively, if the static head developed in condensed stream 54 is sufficient due to the placement of components within a cold box, device 72 might simply be a valve.
[0045] As stated above, first oxygen-enriched liquid stream 30 is subcooled within a subcooling unit 32 which can be a brazed aluminum heat exchanger that in fact can be part of heat exchanger 12 . First oxygen-enriched liquid stream 30 is subcooled by partly warming waste stream 60 and nitrogen product stream 20 . After having been partly warmed, waste stream 60 and nitrogen product stream 20 are introduced into main heat exchanger 12 to cool the incoming compressed and purified steam 10 .
[0046] Waste stream 60 upon its discharge from shell 70 typically can have a pressure of between about 2 and about 7 bar absolute. In the illustrated embodiment, the apparatus 1 is refrigerated by partly warming waste stream 60 within a main heat exchanger 12 to form a partly warmed stream 74 that is then expanded within a turboexpander 76 to produce an exhaust stream 78 that is fully warmed within main heat exchanger 12 to a temperature and pressure near ambient, thereby to refrigerate apparatus 1 . The shaft work of expansion may be imparted to a generator or used to compress air, nitrogen or waste stream 60 prior to expansion or dissipated by an oil brake as heat. It is to be noted that a portion of stream 74 could bypass turbine 76 and directed into exhaust stream 78 by use of a valve. Other types of refrigeration are possible with the present invention, including, an external refrigeration source or even air expansion as illustrated in the prior art.
[0047] As illustrated in FIG. 2 , nitrogen-rich liquid stream 54 is formed by a first part 52 a of vapor phase stream 52 . A second part 52 b of vapor phase stream 52 is passed within main heat exchanger 12 ′ and then compressed within a compressor 80 . After having been fully warmed within main heat exchanger 12 ′, second part 52 b of vapor phase stream 52 can then be combined with compressed and purified stream 10 to form a combined compressed and purified stream 11 . After cooling within main heat exchanger 12 ′, a purified, pressurized and cooled stream 13 ′ is produced for introduction into rectification column 14 . It is to be noted that a similar configuration might involve splitting of partially warmed stream 74 to subject a portion of the flow to compression and return another portion to the base of rectification column 14 . Another alternative would be to recycle second part 52 b of vapor phase stream 52 back into the distillation column 14 by provision of separate passage provided in the main heat exchanger 12 ′ for such purpose. Moreover, waste stream 60 could be directed to another rectification section or alternately, could be warmed, compressed and then fed to a similar process.
[0048] The present invention is applicable to any number of combinations of rectification columns forming similar functions to that as described. For example, rectification column 14 might employ an auxiliary reboiler for further increase and recovery. In such an arrangement, an additional stream of air and nitrogen would be compressed to a higher pressure and condensed within the reboiler and thereby to provide additional vapor flow.
[0049] Furthermore, rectification column 14 may employ a combination of packing, dumped and structured. Rectification column 14 could be split into multiple sections. As known in the art, a “reflux pump” may be employed to motivate column liquids to and from the column sections. In this regard, device 72 might be a mechanical pump that serves as both a reflux pump and a pressure manipulation device.
[0050] In a further possible embodiment of the present invention, other oxygen-enriched fluid might be extracted from rectification column 14 and added for the make-up of oxygen-enriched liquid stream 30 for purposes of temperature control or to reduce the size of first heat exchanger 36 , second heat exchanger 50 and third heat exchanger 56 .
[0051] It is also possible to utilize certain aspects of the present invention without the direct use of heat exchanger 12 or 12 ′ (or preceding compression and prepurification equipment). For example, a conventional single column nitrogen generator could be utilized to generate the purified, pressurized and cooled stream. Such a stream could be obtained from the vaporized oxygen-enriched bottoms extracted from the condenser in association with the single column nitrogen generator. In this regard, the single column nitrogen generator would preferably operate within a pressure range of between 10 and about 20 bar. Rectification column 14 would operate as described above. Nitrogen product and waste streams would pass through the main heat exchanger in a manner similar to that described with respect to FIG. 1 .
[0052] While the present invention has been described with reference to a preferred embodiment, as will occur to those skilled in the art, numerous changes and additions can be made without departing from the spirit and the scope of the present invention as set forth in the presently pending claims. | Method and apparatus for distilling nitrogen from a gaseous mixture containing nitrogen and oxygen. Oxygen-enriched bottoms liquid is partially vaporized within a first heat exchanger to condense part of the column overhead to produce reflux. Thereafter, the partially vaporized oxygen-enriched liquid is phase separated. A second oxygen-enriched liquid stream composed of at least part of the liquid phase is used to substantially condense all or part of the vapor stream derived from said phase separation, thereby to form a nitrogen-rich liquid stream. At least part of the nitrogen-rich liquid stream is reintroduced into the column to increase nitrogen recovery. The second oxygen-enriched liquid stream is then used to condense a second part of the reflux for the column. | 5 |
FIELD OF THE INVENTION
This invention relates to a method and apparatus for utilizing a cryogen including the manipulation, management and control of a cryogen. Cryogen can be utilized in the production of frozen and/or solidified small volumes of desired substances. The small volumes of solidified substances, also called pellets or granules in prior art, are hereinafter referred to as units.
The invention also relates to a method and apparatus for the manipulation, management, and control of the main body of the cryogen in combination with its internal currents.
BACKGROUND OF THE INVENTION
The desire for small volumes of substances, individually frozen or solidified has become greater as the technology has improved and the awareness and availability of such a product has increased. This demand includes food type products, bioactive products, chemical products, and in general any liquid, semi-liquid, semisolid or solid that may be desired to be frozen or solidified in small individual units. Small individual units do not demand the thawing of a large amount of product for utilization. Measurability, novelty, convenience, reduced waste, higher quality, ease of use, flowability, handling, minimizing cellular damage, and maximizing product efficacy are also advantages that industry is discovering with small frozen or solidified units. This demand has created a need for a product that has reasonable consistency of size, shape and other physical characteristics.
In the field of bio-active products, small frozen or solidified units have significant advantages. The freezing process is very fast and results in minimal cellular and structural damage, which provides maintenance of the desired bioactive characteristics.
The rapid freezing minimizes cellular damage caused by the formation of ice crystals, normally associated with freezing. Bioactive products are often freeze dried for storage. The characteristics of the units make them excellent for freeze drying. The more consistent the size and form of the units, the more favorable they are for a freeze drying process.
One of the advantages of a small volume of frozen or solidified product is that it can be made to flow like ball bearings (flowability). Thus, the handling of specific amounts of units that may vary with demand is possible. Agglomeration and deformed individual units inhibit the ability to flow as desired.
Measurement and utilization is also an important feature. If an average weight of the product is known, a specific amount can be utilized without thawing a larger block of product. The thawing of the desired amount of product is faster as a direct result of the relatively large surface area per unit of weight as compared to a frozen block of product. Many characteristics are improved significantly as a result of the rapid freezing or solidification of the small volume of liquids.
There is prior art in the field of production of frozen units by utilizing a cryogenic liquid. Much of the known art utilizes a particular cryogenic liquid, such as Liquid Nitrogen (LN2).
The main problem with the prior art is that the small volumes of substance are introduced into the cryogen with relatively little consideration of the manipulation and management of the cryogen itself. This results in the formation of random or poorly formed units. Creation of deformed units is commonly referred to as the “popcorn” effect. The units look like “popcorn” rather than smooth spheres.
Consistency of size, structure, texture and surface quality as well as control of agglomeration has not been able to be a manageable and controllable feature previously. All of these variances result from the inability to control and manage the rapid heat transfer that occurs in the process. This rapid heat transfer results in remarkably violent gasification, which results from introduction of a relatively warm substance into the extremely cold cryogen. Gasification occurs at the interface between the cryogen and the forming units. Violent gasification results in cavitations at the surface of the cryogen resulting from the creation of gas bubbles, which can break the surface of the cryogen. Gas bubbles bursting at the surface of the cryogen can lead to incomplete and non-uniform immersion of the introduced substance into the cryogen. It also causes the units to violently interact. This violent interaction results in significant structural alterations of the units.
Agglomeration is also often a problem as the rapidly forming units often combine with other units resulting in multiple units combining and solidifying together. This agglomeration affects the flowability of the product as well as affecting other desired qualities
The relevant prior art is referenced as follows:
Canadian Patent #937450:
This patent describes the deformation that would naturally occur when a small volume of liquid is entered into a body of cryogenic material.
Canadian Patent #964921:
This art describes a small volume of liquid being introduced into an unmanaged and static body of cryogenic liquid.
Canadian Patent #1217351 and U.S. Pat. No. 4,655,047:
This patent describes the improved formation frozen pellets. This patent describes the introduced liquid relative to speed into the body of cryogenic liquid.
Canadian Patent #2013094 and U.S. Pat. No. 4,982,577:
This patent identifies the previous patents' lack of ability to control the exposure of the cryogenic liquid to external heat sources and thereby the subsequent waste of the cryogenic liquid. Although it establishes a good method of handling the liquid for the purposes of cost, it does not identify, mention or claim the benefits of a process of manipulation of the fluid dynamics of the cryogenic liquid to produce the ability to manage the characteristics of the introduced liquid as it solidifies.
U.S. Pat. No. 4,687,672:
This patent describes a freezing of large volume of product and its subsequent fracturing and grinding to produce a granular product.
U.S. Pat. No. 5,126,156:
This art describes a liquid being introduced into a cryogenic liquid without any reference to manipulation or management of the cryogenic liquid only referring to the removal of the pellets from the liquid after freezing and a screening process to extract only the pellets from the liquid via an auger in a similar fashion to Canadian patent 964921.
U.S. Pat. No. 6,000,229:
The art is basically a tub of cryogen with an introduction point of cryogen. In addition an auger for the removal of solidified pellets. There is not any attempt to manage the heat transfer, gasification or other destructive aspects.
Generally, the prior art in the field focuses on the actual small volume of liquid being introduced and the handling and removal of subsequently-frozen product from the liquid cryogen. The prior art typically does not identify or discuss what actually occurs within the body of the cryogen or any methods or apparatus for managing the heat transfer and gasification that directly affects the structure and formation of the pellet being produced.
OBJECTS OF THE INVENTION
The synergistic effects of the type of management of the present invention include but are not limited to:
a) The dispersion of gas produced by the heat transfer between the thermally different introduced substance and cryogen. b) The dispersion of the heat transfer between the introduced substance and cryogen into the general body of the cryogen. c) Maintaining a physical distance between individual units such that the destructive aspects of physical interactions are minimized.
This enables the improved management, control and determination of the desired characteristics of the individual units. The characteristics managed are the shape, size, surface texture, deformation, frozen satellites, fines, and agglomeration of the introduced units as they are frozen or solidified.
Accordingly, several objects and advantages of the present invention include the manipulation and subsequent management of the cryogen utilized in the solidification of a series and/or multiple units of small volumes of a substance introduced into the cryogen. In general practice the cryogen utilized may be Liquid Nitrogen (LN2) or other suitable low temperature liquid.
Accordingly a primary objective of the present invention is the creation of the synergistic effects resulting from a method and apparatus for the manipulation and management of both the general fluid body (Fluid Body Movement) as well as the internal fluid dynamics (Currents) of the cryogen. These synergistic effects are utilized to control the characteristics of the frozen unit resulting from the introduction of that unit into the body of cryogen, such as Liquid Nitrogen (LN2). The controlled characteristics may include the surface structure, agglomeration, fines, satellites, average size, roundness and the prevention of ice crystallization.
Another object of the present invention is the physical movement of an introduced unit out of the introduction area of subsequently introduced units as a result of the unit being carried by the flow of the LN2.
Another object of the present invention is the reduction of physical interaction of forming and formed units with each other thereby avoiding the obvious physical damage that the firmer formed unit would cause to the forming units.
Another object of the present invention is to facilitate the dispersion of the gasification resulting from the interface between the small introduced unit and the cryogen. This dispersed gasification also assists in the enhancement of currents within the body of the cryogen.
Another object of the heat and gasification dispersion resulting from operation of the present invention is faster heat transfer from the introduced units into the liquid cryogen, as a result of increased direct contact between the forming unit and the LN2.
Another object of gas dispersion resulting from operation of the present invention is the minimizing of physical damage done as a result of the violent gasification on the forming unit.
Another object of the invention is the ability to regulate properties of the units, including these characteristics of the solidified or frozen unit, as the market requires. Properties can range from “popcorn” type products with or without agglomeration to smooth sphere like units that are individual in nature and of primarily similar size and shape.
An additional object of the invention is the utilization of a recycling system to create the desired flow of the cryogen.
An additional object of the invention is the utilization of a sloped raceway of varying designs to maintain the flow of the cryogen.
Another object of the invention is the length of the raceway. The length of the raceway, from the point of introduction of units into the cryogen to the point of units/cryogen separation at the removal mechanism for said units, can be calculated utilizing cryogen flow speed and desired retention time of the units in the cryogen.
Another object of the invention is the encouragement or discouragement of the internal currents within the body of the cryogen as a result of the recycling process to assist in desired results.
Additional objects, advantages, and other novel features of the invention will be set forth in part in the description and scientific explanation that follows and in part will become apparent to those skilled in the art upon examination of the following or may discerned from the practice of the invention.
The prior art does not manipulate, manage or utilize any of the described factors that occur in the cryogen. Previous patents simply introduce a unit into a body of cryogen. The gasification of the LN2 is sufficiently violent that the introduced unit appears to float or levitate on top of the LN2 as a result of the lift power of the gasification. This occurs in spite of the fact that units, in general, are heavier than the LN2. The units at the surface or near the surface are a combination of individual units in all three stages of formation moving violently and randomly. With the violent gasification and the combination of all stages of formation in close proximity it can easily be understood by anyone skilled in the art why the deformation, damage, fragmentation and agglomeration and other characteristics result.
To achieve the foregoing and other objects and advantages, and in accordance with the purposes of the present invention as described herein, a method and apparatus for producing the desired synergistic effects by manipulation of both the body and internal fluid dynamics of the cryogen utilized in the production of a free flowing frozen or solidified product resulting from the introduction of small volumes of liquid called units into the body of liquid cryogen.
SUMMARY OF INVENTION
The cryogen, preferably Liquid Nitrogen (LN2), may be drawn from a reservoir or sump at the bottom of the apparatus, by a means to remove said cryogen from the reservoir, such as a recycling system. The recycling system may comprise one or more augers; however, other recycling methods could be utilized. One or more augers may be utilized depending upon desired results. Multiple augers can provide a greater recycling volume as well as increased internal currents. An apparatus which creates a suction effect, or another means to elevate the cryogen from the reservoir may be suitable.
The recycled LN2 may be moved substantially vertically or upwards from the sump by rotation of an auger. The upward motion of the cryogen may result in a bubbling spring effect when the cryogen: begins to transition to horizontal flow. Also, there may be internal currents created within the body of the cryogen that are initially caused by the auger or other recycling system.
A cryogen auger (as example of pumping methodology) does not have to be completely vertical however the preferred arrangement for lift is an auger that is substantially vertical with a plurality of flutes to be machined at a preferred angle of about 14 degrees from center with a quantity of flute flights of between about 8 and 10 per auger. The flutes preferred spacing is about 2.5 inches apart. The most preferred condition is a substantially vertical auger with a flute angle of 14 degrees from center with a quantity of flute flights of 8 with a spacing between flutes of 2.5 inches. If it is decided to employ an auger angle other than substantially vertical all flute angles and quantity of flutes thereof can be adjusted accordingly to offset the other than substantially vertical condition to allow for similar lifting volume of the cryogen. Large numbers of flutes are possible but can result in added vibration.
The vertical movement of the cryogen can develop into a fundamentally horizontal movement as it flows away from this transition point. At the transition point, back currents created by a vertical flow may dissipate and before the introduction of the small volume of substances at the introduction point. Once the flow evolves to a fundamentally horizontal flow the currents created by the recycling system disperse any minor gasification that results, resulting in a reasonably smooth surface on the LN2. The initial slope of the raceway at the product/cryogen interface will assist in the management of the speed and depth of the body of LN2 at this juncture with the preferred slope being between about −5 degrees (upward slope) up to about +15 degrees downward slope from the horizontal and the most preferred slope being +5 degrees downward from the horizontal. The subsequent angle of travel along the raceway beyond the interface point is preferred to be about +5 to about +15 degrees downward slope with the most preferred at +7 degrees.
If the current is too strong for the desired results, a screen or baffles can be utilized in advance of the introduction point of the small volumes of liquid to slow down the internal currents.
The distance of the exit of the recycling system at the point of transition from vertical to horizontal flow to the introduction point of the small volume of desired substance may be of sufficient distance such that the vertically moving LN2 being recycled converts to horizontal flow, thereby allowing any back eddies created by the vertical flowing liquid changing to a horizontal flow to dissipate and settle and become a non-factor in the current of the cryogen. This distance may be a factor associated with the maximum flow that the recycling system is capable of creating.
Once the LN2 has achieved a smooth surface and a substantially mono-directional horizontal flow, a desired substance may be introduced into the cryogen via a nozzle either under pressure or by gravity feed. The substance that is introduced may be a stream, or as individual measured droplets in varying degrees of frequency or precision depending upon the desired production outcome required. The height of the nozzle above the introduction zone may be adjustable due to desired characteristics of units. Preferably, the nozzle may be at a height sufficient to limit disruptive current resulting from introduction of the substance. Also, preferably the introduction of the substance will not cause upward spray of the cryogen. The horizontal movement of the LN2 can move the forming unit out of the introduction zone where subsequent units may be continuously introduced into the cryogen.
The inherent and artificial currents in the LN2 may disperse the gasification created by the introduction of the small volumes of relatively warm substance into the cryogen. Dispersion of this violent gasification at a point away from the introduction zone may enhance the internal currents within cryogen.
The LN2 can be guided down a sloped raceway. The raceway is constructed in a variety of formats depending upon the desired effect, substance being frozen or solidified, and desired retention time. The raceway may have a stainless steel surface, such as a “mirror” finish applicable in stainless steel polishing in the pharmaceutical industry, or other applications where a smooth finish is utilized. Finishes are typically determined pursuant to the regulatory bodies governing such things for individual industries, such as the FDA. These surface finishes can facilitate cleaning and disinfection of the system when required. In industry, often when there is a change from one product type to another it is essential that substantially the entire previous product be removed and cleaned. This is particularly imperative with bio-active products. In addition the smoother the surface the less the frictional resistance of the surface becomes a parameter in the movement of the cryogen or the individual units.
The cross section shape of the raceway may be an expanded “U” shape in order to facilitate cleaning and disinfection after use of the equipment. However, the raceway may be enclosed, such as a tube. A “U” shape can minimize corners that would affect the desired currents and flow for the cryogen. The “U” shape may also minimize damming or conglomerations of the units as they proceed down the raceway.
One embodiment of a raceway may be a spiral raceway. The slope of the raceway can be a function of the desired speed of the body of LN2 that is desired. The length of the spiral can be a function of the desired retention time of the forming and formed units. The longer the raceway or spiral the greater the retention time of the units. The slope of the spiral may also be a function of the desired retention time of the units and the desired speed of the cryogen. A greater the slope of the spiral will increase the rate of flow of the cryogen through the spiral.
The spiral formation can present additional benefits in that the currents and flow may not develop the opportunity to stabilize as easily as they would in a linear raceway.
Another embodiment of a raceway may be a series of linear raceways. The linear raceways may have a similar expanded “U” shape, or may be enclosed in a tube form. The raceway can be made up of a series of cascading linear raceways, whereby a first linear raceway feeds into a receiving linear raceway running in a substantially different direction. This cascading of the cryogen from a first raceway into the receiving raceway may cause a general mixing of the cryogen and the units. This cascading effect may enhance the internal currents within the cryogen.
Again, the overall length of the embodiment of the linear raceway can be a function of desired retention time of the introduced units. A particular velocity of the cryogen and a specific length of raceway may result in different durations that the units are in the body of cryogen in advance of being removed by the extraction system.
The actual number of cascades utilized can be a function of the desired size of the equipment and the enhancement of the currents desired. However, the more cascades that are utilized the more that the internal currents may be enhanced.
A further embodiment of the present invention may be a linear raceway without any cascading or spiral action. Again, the slope and length of this design may be a function of desired speed and retention time of the units.
Upon exiting the raceway, the cryogen may travel through a moving screen or wire mesh belt. Preferably, the screen or wire mesh is of a conveyor belt style. The porous screen or mesh can be designed to allow the passage of the cryogen through it while removing the resultant solidified unit. The separation of the unit from the cryogen can be referred to as the removal point.
The escape of the gasification that has occurred in the cryogen may be via the same exit point as the units on the conveyor belt. Similarly, another advantage may be the utilization of heat transfer from the units to the gas as it escapes with the extraction of the units from the equipment.
Once passing through the screen or belt, the cryogen may be returned to the sump. There, the returned cryogen can be re-fed into the recycling system, and the process be made continuous.
EXAMPLES
In order to effectively describe the advantages of the invention, the physics and science of the introduction of a small volume of substance, preferably a liquid, semi-liquid, semisolid or solid, into a body of cryogen, such as LN2, is presented as follows.
Example 1
For this example water (H 2 O) will be utilized as the sample introduced liquid and Liquid Nitrogen (LN2) will be utilized as the cryogenic liquid.
Definitions and standards utilized:
Temperatures will be presented in Kelvin (K.), with a conversion to Celsius (C.) and Fahrenheit (F.).
1. “Freezing Point” of water (H 2 O)=273.15 K. 2. 273.15 K.=32 degrees F.=0 degrees C. 3. 1 degree Celsius=1 degree Kelvin 4. 1 gram (gm) of H 2 O=1 cubic centimeter (cc) of H 2 O 5. 1 cc.=1 cubic centimeter=1 gram of H 2 O 6. calories=1 calorie=the heat required to raise 1 gram of H 2 O 1 degree K. 7. “Heat of Fusion” of H 2 O=79.7 cal/gm=79.7 cal/cc 8. “Vaporization Point” of Liquid Nitrogen (LN2)=77.4 K. 9. “Heat of Vaporization” of LN2=2.7929 kJ/mol of LN2 10. 1 Mol of LN2=28.0134 gm. 11. 1 cal=4.184 joules 12. LN2=0.807 gm/cc=1.239 cc/gm. 13. 2.79 kJ/mol=23.83 cal/gm=29.526 cal/cc. 14.1 cal converts 0.042 gm of LN2 to gas or 0.034 cc of LN2 to 5.91 cc of Nitrogen gas.
15. Expansion factor of LN2 liquid to a gas at vaporization temperature=174.6 volume of expansion.
When 1 gram (1 cc) of H 2 O is introduced into a body of cryogen, being LN2, the heat transfer falls into three main categories:
1. The energy exchange in the lowering of the temperature of the introduced liquid to the point where a ‘Phase Change’ of the introduced H 2 O occurs. 2. The energy exchange associated with the change of phase “Heat of Fusion” 273.15 K. or 0 C. or 32 F. 3. The energy exchange as the temperature of the units decreases to the desired exiting temperature, below 273.15 K., 0 C. or 32 F.
Above the fusion temperature of water, or pre-solidification:
It requires 1 cal of energy release from the H 2 O for each degree K. of change above the “Fusion” temperature of the introduced water. Therefore it utilizes 0.0411 gm or 0.0339 cc of LN2 for each degree change with a subsequent gas release of 5.9134 cc of Nitrogen gas per degree of change of the H 2 O.
The physical properties of the introduced small volume of liquid may be very vulnerable during this stage as the unit retains its fluid properties, and hence, most susceptible to deformation, separation and fragmentation as well as agglomeration with previously introduced units and each other. As the crust is formed and solidification is initiated, any physical interaction may cause significant deformation of the forming unit, and possible agglomeration with other forming or formed units.
The phase change of the introduced liquid:
It requires 79.7 cal of heat exchange for the “Heat of Fusion” of the introduced product. Therefore this heat exchange vaporizes 79.7×0.0411 gm or 79.7×0.0339 cc of LN2. This result is the release of 471.28 cc of nitrogen gas.
In a practical application the “Heat of Fusion,” as well as the temperature at which the phase change occurs will vary depending upon the number of solids in the unit and the percentages of other liquids in the units such as lipids (fats), salts, spices, etc.
The physical properties of the forming unit at this stage can be vulnerable to a more limited extent. In a practical application the solidification may not occur as rapidly as in the H 2 O example. The presence of oils, solids, etc. in the liquid will result in the product being plastic or soft for a greater range of temperature. This results in a product that can be sensitive to physical damage such as deformation, as well as agglomeration with other units until complete solidification occurs.
Below the fusion temperature, or post-solidification:
It requires 1 cal of energy release from the H 2 O for each degree of change below the “Fusion” temperature of the introduced water. Therefore, it utilizes 0.0411 gm or 0.0339 cc of LN2 for each degree change with a subsequent gas release of 5.9134 cc of Nitrogen gas per degree of desired change.
The ability of the unit, when solidified, to transfer heat may increase once it is solidified. The physical properties of the frozen or solidified fluid below the fusion temperature are essentially constant, and additional damage or deformation is minimal, if even evident. A benefit to dispersion of gas produced and maintenance of distance between forming units is during the forming, pre-solidification, stage of the units.
In a model where the water is introduced at 278.15 K. or 5 C. or 41 F. and the removal temperature is 165 K. that is −108 C. or −162 F., the gas production per cc of introduced H 2 O input is:
Stage 1 = 5 cal × 5.91 cc/cal =
29.6 cc of gas released
Stage 2 = 79.7 cal × 5.91 cc/cal =
471.28 cc of gas released
Stage 3 = 108 cal × 5.91 cc/cal =
638.62 cc of gas released
This is a total of 1139.5 cc of gas produced within the body structure of the LN2 per gram or cc of H 2 O introduced. As evident by this example, rapid Nitrogen buildup, or violent gasification, can result from the introduction of the relatively hot units into the LN2. This violent gasification may have a significant affect upon the internal currents and movement of the units within the body of the LN2.
Escaped gas can be utilized for additional cooling when the units are removed from the equipment on the conveyor screen.
Once the basic structure of the unit has taken place, the gas release of the individual unit slows down and the unit then sinks into the body of the LN2. Without management, virtually all the damage that would have been done to the physical characteristics would have occurred.
In a production system there is also a steady state loss of LN2 due to the operation of the equipment. The LN2 will vaporize even without the introduction of external units. This gasification is approximately 5,500 cc or 5.5 liters or 0.2 cubic feet per minute.
A system producing 200 lbs/hr and operating at an LN2 flow rate of 50% of motor capacity for a single auger LN2 pump and producing a product of approximately 15% to 25% solids will result in the following: The equipment-caused gasification would be approximately 5,500 cc of gas per minute, while the gas production from introduced units would be 1,730,000 cc of gas per min.
Example 2
A production system processing approximately 90 kilograms or 200 lbs of output per hour will release in excess of 1,730 liters or 61 cubic feet of gas per minute. Over 95% of that gas would be released normally at the interface of the introduced units and the LN2. This substantial gas release at the introduction point can lead to many adverse formation conditions, such as those previously mentioned.
In a production example, actual units range in size depending upon the introduction nozzles utilized and the particular characteristics of the liquid, semi-liquid, semisolid or solid. The average size may be from about 0.1 cc to 0.5 cc in size, but not limited to these sizes. The size of the unit will not affect the amount of gasification; however, the speed of the heat transfer will increase as the total surface area per total weight of product increases.
It can also be easily seen by anyone skilled in the art that violent gasification does occur and occurs very quickly at the interface between a forming unit and the LN2. In addition this violent gasification would affect the movement and interaction of units in the body of the cryogen. This type of reaction explains the deformation, size variances, surface characteristics and agglomeration that are noted to occur in the prior art.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cutaway view of the apparatus of the present invention.
FIG. 2 is a cutaway view of the introduction point of the apparatus of the present invention.
FIG. 3 is a perspective view of showing different control means for the present invention.
FIG. 4 is a top view of the screen conveyor belt of the present invention.
FIG. 5 is a side view of the auger of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Having summarized various aspects of the present invention, reference will now be made in detail to the description of the invention as illustrated in the drawings and described in the scientific description. While the invention will be described in connection to these drawings and description, there is no attempt to limit the invention to the embodiment or embodiments disclosed herein. On the contrary, the intent is to cover all alternatives, modifications and equivalents included within the spirit and scope of the invention as defined by the appended claims.
Reference is now made to FIG. 1 showing the apparatus of the present invention. Cryogenic liquid ( 10 ) may be stored in a sump ( 20 ), or reservoir, at the bottom gravitational location of the apparatus. The cryogen may be lifted to the entrance of the raceway ( 24 ) via one or more augers ( 22 ). Alternatively, an impellor-type pump may be used to created vertical flow of cryogen up to the raceway ( 24 ). The cryogen may then transition from vertical movement to horizontal flow, and initiate its travel down a sloped raceway ( 28 ).
The slope of the raceway can be a factor in the management of cryogen movement in the preferred embodiments for the slope being as follows for the top of the raceway at the product/cryogen interface. The length of the raceway, from the point of introduction of units into the cryogen to the point of units/cryogen separation at the removal mechanism for said units, can be calculated utilizing cryogen flow speed and desired retention time of the units in the cryogen.
The preferred slope can range from about −5 degrees (upward slope) to about +15 degrees (downward slope) from horizontal. Most preferably the slope is +5 degrees (downward slope from horizontal). The raceway slope can be produced to be adjustable across a desired range. Beyond the product/cryogen interface the raceway slope is preferred at about +5 to about +15 degrees downward slope with the most preferred at +7 degrees.
The cryogen with units contained therein can pass though a moving screen conveyor belt ( 30 ) that removes the solidified units from the cryogen. The conveyor belt ( 30 ) may be made of a screen, a wire mesh, or any suitable porous material that will filter the solidified or frozen units from the cryogen. The cryogen may then return to the sump ( 20 ) where it is recycled again.
The pumping capacity of the auger can be in excess of the ability of the cryogen in the sump to keep the entrance full of cryogen. If this operational condition was created, cavitations in the cryogen may occur if the auger is run too fast thereby introducing gas into the auger process. Cavitations in the cryogen may result in the vertical flow not being consistent. Also, an embodiment of the recycling system that consists of two or more augers thereby enables an increased flow without causing the undesirable cavitations and subsequent flow inconsistency.
The cryogen auger (as example of pumping methodology) does not have to be completely vertical however the preferred arrangement for lift is as follows: The auger can be substantially vertical with a plurality of flutes to be machined at about a 14 degree angle from center with a quantity of flute flights of between about 8 and 10 per auger. The flutes preferred spacing is about 2.5 inches apart. The most preferred condition is a substantially vertical auger with a flute angle of 14 degrees from center with a quantity of flute flights of 8 per auger, with a spacing between flutes of 2.5 inches. If it is decided to employ an auger angle other than substantially vertical all flute angles and quantity of flutes thereof can be adjusted accordingly to offset the other than substantially vertical condition to allow for similar lifting volume of the cryogen. Large numbers of flutes are possible but can result in added vibration.
Reference is now made to FIG. 2 in which the flow transition point is depicted. The cryogen may be lifted by the auger to enter the raceway ( 24 ). Motion of the auger ( 22 ) may create a circular and vertical direction ( 34 ) of the cryogen. Upon exiting the recycling system at the top of the auger, the direction of the fluid body movement is vertical and circular. The flow may change to a fundamentally horizontal flow. The transition from vertical to horizontal flow may result in the production of back eddies and reverse currents ( 36 ). Back eddies and reverse currents ( 36 ) can result in a spring bubbling-effect up into a body of cryogen then flowing in a horizontal direction.
These back eddies and reverse currents can be allowed to settle out as the fluid converts to basically horizontal flow ( 38 ) in advance of the introduction point ( 42 ) of the small volumes of a desired substance, such as liquid, semi-liquid, semisolid or solid. Upon introduction into the cryogen, these small volumes may be referred to as units. In another embodiment, a control means ( 40 ) may be introduced at the flow transition point to decrease the intensity of the back eddies and reverse currents. The control means may be a barrier, screen, baffle or dam. In a further embodiment, the apparatus may be adapted to inject a time delay for flow transition. In this embodiment, the auger may rotate with slower speed, there may be a dam before the introduction zone, or a diffusion pool may be added after the introduction zone.
The length of the raceway can determine the retention time of the units as a function of desired exiting temperature or required time necessary to ensure solidification in the cryogen given a particular speed of motion. In some cases the depth or speed of the cryogen can be adjusted to adjust retention time. In such cases a baffle, screen or a dam is placed in the raceway after the introduction point. A dam obviously increases the depth of the cryogen. A baffle aids in the direction of flow of the cryogen and units. A screen aids in the control of the internal currents in the cryogen.
The recycling of the cryogen can maintain a constant circular flow as it travels down the raceway back to the sump and up again to the entrance to the raceway ( 24 ).
The small volumes of substance can be introduced to the cryogen flow via a series of introduction nozzles ( 44 ) that introduce the liquid by streaming, or as individual droplets, either by gravity feed or under pressure. Droplets ( 46 ) can be predefined in volume by a specialized pump or can be determined by the particular surface tension of the liquid and form a droplet that can be released like a drip from a dripping tap.
The number of nozzles utilized for the introduction of small volumes of liquid, are a function of the engineering of the total unit. Preferably, multiple nozzles may be utilized. The actual number of nozzles utilized is a function of the total volume of liquid that the system can sustain while still maintaining the desired results. In general, the faster the speed of individual units being introduced, the faster the lateral movement of the cryogen required in order to achieve the results desired. In addition to pure cryogen velocity the higher the number of individual units being introduced the greater the surface area of the introduction point required.
The introduction point ( 42 ) may be positioned downstream from the introduction of the recycled cryogen such that eddies and back currents may have time to settle and a consistent forward flow is achieved. However, the introduction point ( 42 ) may be the same position as the entrance point ( 35 ). The distance from the recycled cryogen entrance ( 35 ) to the introduction point ( 42 ) can be dependent upon the maximum flow capacity desired for the equipment. An example of a desired result at the introduction point is a reasonably smooth surface on the flowing cryogen.
Preferably, the distance between the nozzles is sufficiently distant such that the droplets or steams will not combine with each other before hitting the surface of the cryogen. Combination of droplets may also be a function of the height of the nozzles above the cryogen surface. Also, the nature of the product being processed can influence the combination of the droplets. The distance between nozzles, height above cryogen surface and nature of product being processed are variable and may be adjusted by user-designation.
When a droplet is introduced into a horizontally moving body of cryogen, the resulting unit may be moved away from the introduction point ( 42 ). The faster droplets are introduced, the faster the flow of cryogen that is required to move the unit out of the way of the next introduced unit. Preferably, the unit is transported immediately from the introduction zone by the horizontal cryogen flow, thereby reducing the interaction between droplets and unformed units. The speed of the process may be controlled partly by the volume of cryogen recycled, the speed of the recycling of the cryogen, and the slope of the raceway.
Another management tool is the distance that the droplet will pass through before coming into contact with the LN2. The distance of the droplet height or individual liquid unit height from the body of LN2 can be dependent upon the liquid product to be frozen and could range from very low to very high. The preferred variance is from about 4 inches to about 36 inches above the cryogen. Depending on the product makeup (i.e. solid contents, viscosity and surface tension) and the desired results one wishes to achieve (i.e. consistent shaped pellets of varying degrees or misshapen and agglomerated pellets (i.e. Popcorn shaped) or many other combinations including frozen splatter) the height variance can be substantial. Also, liquid product pumping capacity may require establishment as to hot overburden the system with too much liquid to be frozen and hence compromise the results desired or efficiencies of a certain type and size of unit/equipment. Testing of these parameters can be established to correlate to the needs of a particular end user and hence management for said requirements can be forecasted and built in to satisfying the existing and future needs of a user.
The distance of drop or droplet combined with its size and mass will to an extent demand that a particular depth and speed of LN2 be available in order to inhibit the droplet from hitting the actual bottom of the raceway in advance of the droplet forming its initial crust.
This methodology results in the gasification created by a particular unit not being added to the gasification of the next unit. In addition, increased flow may prevent the physical interaction of units while they are very susceptible to physical damage, as they are remote from each other.
The violent gasification results in cavitations. Cavitations are individual bubbles that eventually break the surface of the cryogen. In effect the surface becomes covered with cavitations, which present a jagged surface to which the droplets contact. However, these cavitations can be remarkably destructive to droplets when they are introduced into the flow of cryogen. Maintenance of a smooth cryogen surface at the introduction area can be one of the essential parameters in managing the form and structure of the resultant units. This may be accomplished by maintaining a steady horizontal flow of cryogen.
As the heat is transferred from the units to the body of cryogen, the currents may move the actual cryogen molecules that are in the process of going through a change of phase or vaporization. Since the actual molecules that are absorbing heat are continually being moved away from the solidifying unit much of the gasification that would normally occur at the interface may be delayed or occur at a point away from the interface.
The internal currents, still active due to the recycling systems' motion, assist in the dispersion of the gas and heat from the interface. The gasification that occurs within the body of the cryogen can create additional currents that assist in the dispersion of subsequent gasification and heat. The movement of the gas bubbles through the fluid body of the cryogen enhances the existing currents and creates new ones. These currents can aid in the desired effect created by the currents. This can minimize physical damage as a result of the violent gasification. The movement of the gasification and heat away from the interface minimizes the normal encapsulation of the forming unit by the gasification. When a unit is encapsulated in gasification the speed of heat transfer is inhibited, as the gas does not absorb heat as quickly as the liquid cryogen absorbs heat. The result of minimizing encapsulation is that physical contact with the liquid cryogen is maximized, thereby maximizing heat transfer.
The newly forming units are physically moved out of the way of the next introduction of units as a result of this controlled lateral flow of cryogen, thereby minimizing the physical interaction of forming and formed units with each other. The continued flow down the sloped raceway can maintain this distance between the units. This may assist in controlling the agglomeration that would be expected to occur, as well as the physical interaction and resulting deformation or structural damage to the units that would result.
Depending upon the product and the management desired in general it is preferred that the cryogen flow be such that product is moved away from subsequent newly introduced product. However for some products minimal or substantial no flow of the cryogen may be advantageous. This is because even without any river type flow of the cryogen there is substantial currents and resulting movement thereof caused within the body of the cryogen as a result of the significant gasification that occurs at the interface between the introduced product and the cryogen. This substantial movement is over and above the great deal of movement that already occurs from the steady state gasification that occurs even without the introduction of the substance to be frozen.
The preferred rate of cryogen flow is relative to the individual liquid units to be frozen however for each product there can be established of a most preferred rate. This is ultimately accomplished through the testing of each individual liquid type product to be frozen and adjusting the parameter for cryogen flow accordingly to establish a most preferred rate. As well the amount of pumping capacity can vary with the size of each piece of equipment constructed and the number of pumping sources available. For some of what may be considered larger sized pieces of equipment produced (this is of course somewhat subjective to individual industry definition of larger scale) a preferred range for cryogen pumping capacity for example would be about 100 to about 150 liters of cryogen per minute into a river width of about 8 to 12 inches. A most preferred rate would be 120 liters per minute of pumping capacity with a river width of 10 inches. It is important to note that this technology is scaleable (small and large). For comparative purposes for smaller sized equipment than that as cited above the above ranges could be about 50% of those values (once again dependent upon industry definition and need). The cryogen depth can be managed to be within a preferred rate of from about 1 inch to about 3 inches deep by adjusting the cryogen flow rate and/or the horizontal slope of the tray and/or by introducing a downstream flood gate/dam or a narrowing of the raceway that will allow more or less cryogen to flow over it past its point of location depending upon the cryogen depth desired.
For example, a product of composition such as skim milk dropping simultaneously from approximately 48 nozzles from a height of between 20 and 25 inches into a flowing cryogen source moving along a 10″ trough at a +5 degree angle at the point of interface and then descending at a rate of approximately 2.5 feet per second for a time of approximately 20 seconds (residence time) will produce a consistent size and shape of pellet in a quantity of approximately 325 to 375 pounds per hour.
In specialized product situations, individual channels can be built in the raceway such that each nozzle utilized at the introduction point directs the droplets to follow a particular channel thereby stopping any horizontal interaction between units that were introduced at the same time.
When the gasification is removed remotely from the interface and mixed into the general body of the cryogen, the gasification can create additional random mini-currents within the body of the cryogen that assist in the general manipulation of the inherent currents and their subsequent effect as well as encouraging continued movement of the gasification.
This movement of the gasification away from the interface inhibits the initial floatation or levitation of droplets caused by the violent gasification ( 52 ), thereby minimizing the interaction of floating units that are randomly thrown around and have the possibility of hitting the sides of the raceway and/or each other.
The form of the raceway can also assist in this management and manipulation. A spiral raceway can continually change the direction of the flow of the cryogen thereby not allowing it to stabilize in a particular direction. A cascading raceway may cause the cryogen to cascade thereby enhancing internal currents and thereby fortifying random currents and flow. A linear raceway may allow the flow to stabilize.
The solidified units may be removed from the flow of cryogen via a conveyor belt screen with spacing in the screen such that the cryogen flows through the belt while the formed units do not flow through the belt. The belt may take the formed units to the exterior of the equipment where they are stored or utilized as desired. The exit of the cryogen gas due to evaporation or gasification from the equipment can be where the conveyor belt removes the solidified units. Therefore, the units after removal from the cryogen may be in an atmosphere of very cold gas. By adjusting the speed of the belt, the time that the units are exposed to this cold gas can be determined. There may be additional cooling of the units from this exposure to the expelled gas. | A method and apparatus for the manipulation and management process of cryogen such that it controls both the fluid body movement as well as internal currents within the cryogen. Small volumes of a desired substance introduced into this managed cryogen for the production of frozen or solidified pellets or granules are better managed as to shape, size, deformation, frozen satellites, fines and agglomeration and overall desired quality. These benefits result from the dispersion of the gas produced, as well as the heat transferred, resulting from the introduction of the relatively hot substance to the cryogen. The fluid body movement assists in maintaining a distance between the individual solidifying pellets or granules thereby minimizing deformation as a result of physical contact. The output characteristics and desired quality of the pellets can be more effectively controlled and managed, as desired. | 5 |
FIELD AND BACKGROUND OF THE INVENTION
This invention relates to sewing machines in general and, in particular, to a new and useful sewing machine having a base with a widened portion defining a console panel having a plurality of operating elements and a selector which may be manipulated for the purpose of varying the zigzag stitch pattern.
DESCRIPTION OF THE PRIOR ART
In the known arrangements of zigzag sewing machines, the control cams and the associated scanning and selecting devices are mounted in the upper arm, (See U.S. Pat. No. 2,999,471), or in the column (See U.S. Pat. No. 3,257,980) of the machine, since more room is available there for the rather voluminous unit. Consequently, the machine's center of gravity is put even higher, further away from the machine's supporting surface due to the great mass of the cam plate and selector assembly, resulting in undesirable vibrations during the operation of the machine.
In addition, the transmission of the control power effecting the motion of the fabric transport and needle bar pendulum must each be accomplished by a shift linkage. Since the positioning forces are very great, in order to keep the fabric transport in its set position, considering the strong thrust forces which attack it during its feeding motion, the transmission elements between the fabric transport and the control cams must be of a rugged design. Due to the great inertial forces away from the center of gravity of the machine, undesired vibrations occur at high speeds. In addition, the backlash existing in the transmission joints causes a severe total bearing slack, impairing the precise control positions of the setting device for the fabric transport.
SUMMARY OF THE INVENTION
The present invention provides a device which avoids the disadvantages mentioned heretofore and creates a simple production engineeringwise, and favorable assemblywise, a feeding and/or overstitch control unit whose control cams and selector can be housed in the area of the machine's center of gravity.
In accordance with the invention, a zigzag sewing machine is provided with a multiplicity of scannable control cams which singly or severally together are connectable to transmission elements for the adjustment of the overstitch width of the needle bar and/or the feed direction of the fabric transport by means of a selector which contains operating elements which are connected to the control cams and the transmission elements. The control cams and the selector are mounted in brackets installed in the base of the sewing machine and the sewing machine base is provided with openings for operating elements of the selector.
This measure results in a displacement of the center of gravity towards the supporting surface of the machine and, thus, in an improvement of the machine's stability. The control cams and the selector are expediently mounted on a common support.
The openings for the operating elements, which are designed in the form of keys to pass through, are advantageously disposed on top of the widening in a sewing machine equipped with a forwardly directed widening of the base relative to the housing. This causes the pressure exerted on the keys to act in the direction toward the supporting surface of the machine, thus avoiding the application of a tilting moment on the machine which automatically originates when keys, disposed in the hitherto known manner in the front of the upper arm, are actuated. In this arrangement, the visibility of the keys is maintained completely intact.
In order to obtain a particularly compact design of the control unit, it is designed so that a positioning member for the control of the feed direction of the fabric is mounted coaxial to the control cams. This makes it possible, in addition, to dispose the positioning member in the immediate vicinity of the setting device for the feed and feed direction, thus accommodating the control unit in the lower part of the machine, and thereby, eliminating the transmission linkage between the control unit and this setting device, which is otherwise required in a rugged design because of the great forces involved. While the transmission linkage to the needle bar pendulum must be made longer, it can remain small in its mass because very little force is required to move the needle bar pendulum.
An advantageous construction for manually setting the positioning member for the feed operation and for the feed control of the fabric transport is effected by an arrangement in which the positioning member is pivoted on the shaft of the control cam and supports a gear segment which meshes with a gear segment mounted on a shaft which is parallel to the shaft of the control cam and is connected to a stop which projects between two inverse positioning cams of a setting disc.
A further favorable solution results from a construction in which a spring pushes the stop against the positioning cam for the forward stitch; that another spring attacks at two points of the engagement which are provided in a drive connection between the positioning member and the stop and which move in the same direction during the shifting motion which has a spacing therebetween which changes furing the shifting.
Through this measure, the spring length is changed much less when shifting the setting device for the feed and feed direction than in the known arrangements, in which one spring end is fastened to the sewing machine housing. For this reason, sewing machines capable of greater stitch lengths can be designed without significantly increasing the force the operator must apply to switch to back-stitching.
In accordance with the invention, there is provided a zigzag sewing machine for sewing fabric, which comprises, a housing having a base portion, a column portion extending upwardly from the base portion and an upper arm portion overlying a portion of the base portion and being connected to the top of the column portion. A needle bar pendulum is mounted in the upper arm portion for swinging back and forth motion and it has a needle bar which is mounted therein for upward and downward motion. A feed mechanism is located in the base below the needle and includes a movable fabric support which is movable for engaging and moving the fabric selectively in forward and opposite reverse directions. The construction includes drive means in the housing connected to the needle bar pendulum and the needle for reciprocating the needle and for moving the needle bar pendulum in a swinging movement of controlled magnitude and rate and also for selectively advancing and retracting the fabric at a controlled rate. The drive means includes a plurality of control cams which are rotatably mounted in the base portion and an adjustable selector mechanism connected to the cams for varying their control operation and a selector member movably mounted in the housing which is exposed in the base portion for adjustment of the control cams and the associated transmission mechanism. The construction is such that the base has a plurality of operating element openings therein with operating elements projecting outwardly from each opening which may be operated so as to vary the drive means to obtain the desired needle swing fabric feed for the particular stitch pattern selected.
Accordingly, an object of the present invention is to provide a zigzag sewing machine in which the control elements for the zigzag operation are located in a base portion of the housing of the machine.
A further object of the invention is to provide a zigzag sewing machine in which the control elements include operating keys which may be depressed in a base portion for influencing the selection of the control cams for controlling either the needle swing or the fabric feed, with the control being advantageously effected by a selector which makes it possible to regulate whether the feeding will be carried out in a first form of feeding by engaging a selected mechanism with one control cam, or in a second form of feeding in which the selected mechanism is engaged with another control cam.
Another object of the present invention is to provide a zigzag sewing machine having base-mounted operating elements for controlling sewing which is simple in design, rugged in construction and economical to manufacture.
The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.
BRIEF DESCRIPTION OF THE DRAWINGS
In the Drawings:
FIG. 1 is a front top perspective view of a sewing machine constructed in accordance with the present invention;
FIG. 2 is a transverse sectional view, partly in elevation, of the sewing machine shown in FIG. 1;
FIG. 3 is a section taken along the line III--III of FIG. 1;
FIG. 4 is a section taken along the line IV--IV of FIG. 2;
FIG. 5 is a section taken along the line V--V of FIG. 4; and
FIG. 6 is a top plan view of one of the operating elements shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to the drawings in particular, the invention embodied therein, comprises, a zigzag sewing machine for sewing fabric which comprises a sewing machine housing which includes an upper arm portion 1 mounted on the top of a column portion 2 which in turn is mounted on a base portion 3, which includes a bottom plate part 4 which underlies a fabric carrying arm 5 of the base portion 3.
In accordance with the invention, the base portion 3 is provided with a widened front part forming a console having a console top surface 3a with a plurality of openings therein for operating elements or keys 38 which project outwardly therefrom. In addition, the console surface 3a has an opening for a selector disc 25.
The fabric carrying arm is offset rearwardly with respect to the remaining portion of base 3 and the stitch-forming tools, in particular, the rotary hook of the sewing machine, is mounted in this portion. A lower shaft 10 which serves to drive the hook (not shown), in a known manner, through a gear 7 (FIG. 2) drives a toothed belt 8, a gear 9 (FIG. 3) and a main shaft 6, mounted in the machine's upper arm. A bracket 11 is fastened in the machine's base 3 (FIGS. 3 and 4) by means of screws 12.
A shaft 13 is mounted in two bearings in the bracket 11. Shaft 13 has a loosely mounted block 14, consisting of a series of control cams 15 disposed one behind the other, preceded by a gear 16. Gear 16 meshes with a gear 17 mounted on the shaft 10. The transmission ratio between gear 17 and gear 16 is 6:1. A positioning crank 18, rigidly connected to a gear segment 19, is rotatably mounted to the end of shaft 13. Positioning crank 18 is guided axially by a retaining ring 20 fastened in an annular slot in the shaft 13.
Gear segment 19 meshes with a second gear segment 21 which is fastened to an angular lever 22, mounted on a pivot pin 23, fastened in the bracket 11 and it carries a stop 24. The stop 24 projects between two positioning cams 26 and 27 formed on the one face of a setting disc 25. The setting disc 25 is mounted so as to be rotatable about a shoulder screw 28 fastened to the bracket 11. The arm of the angular lever 22 carrying the stop 24 has a point of engagement 29 to which one end of a spring 30 is hooked whose other end is hooked to a point of engagement 31 at an arm of the gear segment 19. The two points of engagement 29 and 31 are disposed on parts of the drive connection which move in the same direction. In addition, the transmission ratio of the system formed by the angular lever 22 and the gear segments 21 and 19 of the drive connection is selected so that the point of engagement 31 disposed near the positioning member 18 travels a longer distance during their common motions than the point of engagement 29. Since the spring 30 assumes its least extended position, it turns the system, so that the stop 24 contacts the inner positioning cam 26.
When the angular lever 22 and the gear segment 19 pivot, the points of engagement 29 and 31 are also pivoted. This causes the position of the effective lever arms, produced by the force of spring 30 acting on these two parts, to shift. When pivoting the stop 24 counterclockwise, the lever arm of the spring force attacking the point of engagement 29 becomes greater while the lever arm of the spring force attacking the point of engagement 31 becomes smaller. This is why the increase in tension applied to the two points of engagement 29 and 31, which occurs during this turning motion due to the extension of spring 30, can essentially be cancelled out if the location of the two points of engagement 29 and 31 is chosen so that the change in spring force caused by the shifting of the two lever arms is inversely proportional to the change in spring force effected by the transmission ratio of the drive connection between the points of engagement 29 and 31.
A selector is installed in the bracket 11 (FIG. 3). For this purpose, a number of levers 34 matching the number of control cams 15 is suspended from a shaft 33 mounted in the bracket 11. Each of the levers 34 has a detent arm 35 and an arm 36 which projects upwardly. An operating element 38, projecting through an appropriate opening 37 in the top of the base 3 and designed as a key, is attached to each of the arms 36. A cam follower 39 having two scanners 40 and 41 is rotatably mounted to each lever 34.
The levers 34 can each be detained in two positions by a detaining rocker 42 pivoted in the bracket 11. For this purpose, their detent arms 35 have a detent 43, each of which can lock in one each of two matching depressions in the detaining rocker 42 which is pushed against the detents 43 by a spring 45. The levers 34 have shoulders 46 against which flat springs fastened to the bracket 11 support themselves. The flat springs 47 have stops 48 contacted by the raised levers 34.
The scanners 40 disposed on the one side of the cam followers 39 can interact with one each of the juxtaposed control cams 15 while the scanners 41 disposed on the other side of the cam follower 39 contact a swinging frame 49 mounted in the bracket 11 by means of a shaft 50. The swinging frame 49 is connected to a pin 51 which is engaged by a pull rod 52 connected to a needle bar pendulum 55 through a shift lever 53 (FIG. 2), hinged in the upper arm 1, and via a connecting rod 54. The needle bar pendulum 55 is hinged to a pin 56 in the upper arm 1 and carries a vertically movable needle bar 57. The bar 57 is rigidly joined to a trunnion 58 engaged by a guide rod 59 which is hinged to a crank 60 fastened to the main shaft 6.
An angular lever 61 is mounted on the shaft 33 (FIG. 4). The lever 61 has a guide pin 62 which projects into a control slot 63 in the face of the setting disc 25 opposite the face with the setting cams 26 and 27. A feeler arm 64, which has a feeler 66 pushing against a control cam 65 and a feeler 68 directed towards a stop 67 rigidly joined to the gear segment 21 is mounted to the angular lever 61. As seen in FIG. 5, the control cam 65 is rigidly joined to the gear 16.
The positioning member 18 of FIG. 5 is connected through a pin 69 to a guide rod 70 hinged by means of a pin 71 to another guide rod 72. Pin 71 is engaged by an eccentric rod 73 encompassing an eccentric 74 mounted on the shaft 10.
The guide rod 72 of FIG. 2 is connected to one arm of an angular lever 75 fastened to a shaft 76 mounted in the fabric carrying arm 5. Another arm of the angular lever 75, projecting upwardly, has a guide slot at its end, in which a pin 77 is guided. The pin 77 is fastened to a carrying arm 78 which is movably mounted on a horizontal shaft 79 fastened in the fabric carrying arm 5 parallel to the feed direction. The carrying arm 78 supports a fabric transport 80 at its free end, whose teeth act upon the fabric being sewn through slots in a stitch plate 81. The carrying arm 78 supports itself on a lifting cam 82 fastened to the shaft 10.
A lever arm 83 which projects upwardly into the path of an arm 84 of an operating lever 85 and interacts therewith to reverse the feed direction to backstitching, is fastened to the gear segment 21 (FIG. 4).
The operating lever 85 is mounted in the column 2 of the machine and is braced against an upper stop 87 by a spring 86 anchored to it and to the column 2.
In a setting range a, the positioning cams 26 and 27 provided on the setting disc 25 are designed inverse to each other, i.e., the feeds settable by it in forward and reverse directions are each the same in size. In this range, the inner positioning cam 26 serves to set the feed in a feeding direction, with the stop 24 normally resting against it. The positioning cam 27 serves the purpose of switching the feed direction to reverse by moving the stop 24 against the cam.
In the setting range b, the positioning cams 26 and 27 are designed so that the feed can be changed from a minimum to a maximum by the positioning cam 26, while the positioning cam 26 is outside of the normal range of motion of stop 24.
The operating elements 38 (FIG. 6) each carry two symbols 88 and 89 of sewing patterns which can be selected after the actuation of the respective operating element 38. In order to differentiate between the two symbols 88 and 89 defined on each operating element 38, the symbols can be of different color.
The sewing machine operates in the following manner:
When the main shaft 6 of FIG. 2 revolves, the shaft 10, driven via the gears 7 and 9 and the toothed belt 8, revolves at the same speed as the main shaft 6. The shaft 10 drives the block 14 mounted on the shaft 13 at a 6:1 transmission ratio through the gears 17 (FIG. 3) and 16,
The eccentric 74 (FIGS. 2 and 5) which pivots the angular lever 75 via the eccentric rod 73 and the guide rod 72 co-rotates with the shaft 10, with guide rod 72 thereby imparting translatory motions to the carrying arm 78 and, thus, also to the fabric transport 80.
The lifting motion of the fabric transport 80 by the lifting cam 82 fastened to shaft 10 takes place in harmony with the translatory motion, in which the teeth of the fabric transport 80 rise above the surface of the stitch plate 81, engaging the material being sewn.
The setting of the size of the feeding steps by the fabric transport 80 is accomplished by moving setting disc 25 (FIG. 4), if the stop is within the adjustment range a of the positioning cams 26 and 27. The stop 24 rests against the inner positioning cam 26 under the influence of the spring 30 and moves the positioning member 18 through the angular lever 22 and the two gear segments 21 and 19, with the pin 69 serving as a pivot pin for the guide rod 70 (FIGS. 3 and 5). During the swing-out motion of the pin 71 due to the eccentric rod 73, therefore, the guide rod 70 performs a relative motion around its hinge point on the angular lever 75, in addition to this rotary motion. This relative motion is transmitted as a translatory motion to the carrying arm 78 via the angular lever 75. The carrying arm 78 slides back and forth on the shaft 79, thereby imparting translatory motions to the fabric transport 80 fastened to its free end, the size of which depends on the setting of the set screw 25.
Reversing the fabric transport 80 to back-stitching is accomplished by depressing the operating lever 85 (FIG. 4) against the pull of spring 86. The arm then pivots the lever arm 83 counterclockwise in FIG. 4 so that the gear segment 21 connected to the arm 84 pivots the angular lever 22 until the stop 24 contacts the positioning cam 27. At the same time, the positioning member 18 is pivoted by the gear segment 19 into its position intended for sewing backwards.
Upon the release of the operating lever 85, the positioning member 18 and the stop 24 return into their previous positions under the influence of spring 30, and the operating lever 85 contacts the stop 87.
The deflection amplitude of the needle bar pendulum 55 is controlled by actuating one of the operating elements 38 (FIG. 3). When depressing an operating element 38, the associated lever 34 is pivoted down and its detent 43 locks in the lower depression 44 of the detaining rocker 42. During the pivoting motion of the detaining rocker 42 occurring thereby against the pull of spring 45, a lever 34 previously detained in the depression 44 is pushed upwardly by the associated flat spring 47 against the stop 48 of elastic design for noise suppression. The detent 43 of lever 34 freely enters the upper depression 44.
Due to the motion of the actuated lever 34 into its lower position, the cam follower 39 which is hinged to it is caused to contact the associated control cam 15 and the swinging frame 49. Therefore, as the block 14 revolves, the selected control cam 15 pivots the swinging frame 49 via the associated cam follower 39, with the swinging frame 49 thereby deflecting the needle bar pendulum 55 in accordance with the contour of the selected control cam 15 via the pin 51 connected to the swinging frame 49, the pull rod 52 and the connecting rod 54. This causes the sewing machine to sew a sewing pattern corresponding to the lower symbol 88 on the operating element 38 of the depressed lever 34.
When shifting the setting disc 25 into the range in which the stop 24 is in the adjustment range b, resting against the inner positioning cam 26, the positioning cam 25 pivots the angular lever 61 through the guide pin 62 engaging its control slot 63 so that the scanner 68 of the cam follower 64 rests against the stop 67 of the gear segment 21 and its scanner 66 against the control cam 65, on the gear 61.
As the block 14 is driven, the control cam 65, in addition to the selected control cam 15, which causes the lateral deflection of the needle bar pendulum 55, now controls the motion of the positioning member 18 via the cam follower 64, the stop 67 and the gear segments 21 and 19. The deflections of the positioning member 18, in a manner already described, influence the feed and feed direction of the fabric transport 80. The design of the control cam 65 is such that the fabric transport 80 performs two feed steps in a forward direction and one subsequent feed step in a reverse direction. Due to this combined control of the needle bar pendulum 55 and fabric transport 80, the sewing machine sews a sewing pattern corresponding to the upper symbol 89 on the operating element 38 of the depressed lever 34.
The two basic colors of the symbols 88 have also been used to letter the setting disc 25 for the selection of the two setting ranges a and b so that the setting disc 25 can be set unmistakably to the desired one of the two symbols 88 or 89 of the selected operating element 38.
Either all or some of the control cams 15 may also be connected, in a manner known per se, to the positioning crank 18 for the control of the feed motion of the fabric transport 80 instead of to the needle bar 57, by means of transmission elements provided between the control cams 15 and the positioning crank 18, which is designed analogous to the described arrangement between the control cams 15 and the swinging frame 49. Of course, the contour of these control cams 15 must then be adapted to the feed and feed direction of the fabric transport 80 to be controlled. By appropriately selecting the operating elements 38 of the selector 32, an automatic control of the lateral deflecting motion of the needle bar 57 only or of the feeding motion of the fabric transport 80 only, or else the joint control of both the needle bar 57 and the fabric transport 80 can then be actuated.
In the zigzag sewing machine of the present invention, with a multiplicity of control cams 15 and 65, the cams are connectable by a selector 32 to transmission elements for the adjustment of the overstitch width of the needle bar 57 and/or of the fabric transport 80. To favorably place the machine's center of gravity, the control cams 15 and 65 and the selector 32 are mounted to one common bracket 11 which is fastened in the base of the machine. In order to achieve a compact and simple design of the control unit, the positioning member 18 for the control of the feed and feed direction of the fabric transport 80 is mounted coaxial to the control cams 15 and 65.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles. | A zigzag sewing machine for sewing fabric, comprises, a sewing machine housing which has a base portion which underlies an upper arm portion which is supported on a column extending upwardly from the base portion. A needle bar pendulum is mounted in the upper arm for swinging back and forth motion and a needle bar is mounted therein for upward and downward motion. A feed mechanism is located in the base portion below the upper arm and it includes a movable fabric support which is engageable with the workpiece to move it selectively in either a forward or backward direction. The drive mechanism for driving the feed mechanism and for controlling the swinging movement of the needle bar is contained in the base portion and it is operated under the control of a plurality of control cams by an operating element which is moved by depressing a key in a wall of the base portion so as to vary the type of stitch pattern which is effected. | 3 |
FIELD OF THE INVENTION
[0001] The present invention to a grill for cooking food that is equipped with top and bottom cooking elements movable toward and from one another for cooking food through both sides to reduce cooking time.
BACKGROUND OF THE INVENTION
[0002] Some grills are equipped with top and bottom-heating surfaces so that meat placed between the heating surfaces is cooked from both the top and bottom sides of the meat simultaneously to reduce cooking time. Unfortunately, the cooked meat is often tough because fat contained in the meat has insufficient time to dissolve meat fibers to tenderize the meat. Fat also imports flavor to meat and, when meat is cooked very rapidly, the liquefied fat does not have sufficient time to permeate the meat to develop the full flavor. When these grills cook meat such as hamburger, pork chops, and chicken fillets, they are usually cooked done yielding dry meat, which is tough to chew. Sauces are sometimes applied to the meat after cooking to add moisture and enhance flavor. Unfortunately, applying sauces on top of the meat does not enhance flavor throughout the meat adds very little moisture. It is desirable to have a grill that can cook foods quickly without destroying the flavor or drying out the meat.
[0003] Some grills drain fat to a dish to keep it away from the meat during cooking. As the fat is removed from the meat during cooking, the meat dries and flavor is lost. To combat this tendency, meat is sometimes marinated in a mixture of vegetable oil and seasonings that are somewhat absorbed by the meat prior to the cooking which may increase the moisture content and flavor of the cooked meat. Vegetable oil tends to stay on the surface of the meat where it is removed during the cooking process even before the animal fat is rendered liquid and drained from the meat. Marinade is therefore ineffective in reducing the fat content of the cooked meat. The marinade, however, can enhance the flavor of the meat because the spices and other liquids in the marinade are absorbed deeper into the meat than the oil to enhance flavor.
[0004] While the marinade can improve the flavor of the cooked meat, its effectiveness is dependent on the liquid in the marinade displacing the liquid in the meat prior to cooking. The displacement process proceeds very slowly at refrigerator temperatures and may take several days for maximum displacement which is impractical in a restaurant setting because of the extra refrigerator space required. The process can be carried out faster at room temperature, but leaving meat at room temperature for the time required for the marinade to be effective gives harmful bacteria a chance to multiply. It is desirable to have a grill that can decrease the fat content of the cooked meat while retaining moisture and flavor without increasing refrigerator space required.
[0005] In prior grills the marinade emanates from a cup located in the center of the bottom cooking surface. The marinade flows through the grooves and migrates upward as it evaporates. Moisture from the food vaporizes during cooking and that moisture vaporized by the top cooking surface has a tendency to be forced downward through the food which helps tenderize and flavor the food. Unfortunately, the downward vaporized moisture retards upward movement of the vaporized marinade resulting in less than through penetration of the marinade. It is therefore desirable to have a way to for the marinade to completely penetrate the cooking food to impart uniform flavor and moisture.
[0006] When meat is cooked by heating it from the top and bottom simultaneously, rendered fat accumulates on the cooking surfaces of the grill because less evaporates due to the top heating surface. Some grills remove the rendered fat by providing grooves in the cooking surfaces so that the fat can drain into a dish. The grooves in the cooking surface are slanted so that the grease flows by gravity for collection. While this process does remove and capture the rendered fat, it is not practical in a restaurant setting because the rendered fat is hot and therefore hazardous. There is an opportunity for the rendered fat to spill or splatter on a worker and there is the possibility that a worker could be injured by steam exiting through the grooves from the cooking process. It is therefore desirable to have grill where grease is easily captured and removed without exposing workers to it while the meat is cooking. Accordingly, it would be appreciated, that it would be highly desirable to have a grill that captures rendered fat for safe and easy removal.
[0007] A problem with grills is that during the cooking process, in addition to fat collecting on the grill, scraps of meat or other cooking debris also accumulate on the cooking surface and must be removed. When left on the cooking surface, the cooking debris will bum importing undesirable flavors to the food that is cooking. It is therefore desirable to have a simple method of removing cooking debris from the surface of the grill after each use.
[0008] Another problem with grills is that cleaning the cooking surfaces is difficult. The bottom cooking surface is a horizontal plane at a fixed height that is not comfortable for all workers, while the top cooking surface must be raised over the heads of some workers for cleaning. It is desirable to have cooking surfaces that are easily accessible for all workers.
[0009] Still another problem with grills is that vapors and smoke from cooking permeate the air with odors and grease. Vapors and smoke escape from the space existing between the top and bottom cooking surfaces. Even though the top surface overlaps the bottom surface, there is space existing between the two where vapors and smoke escape. It is desirable to have a venting system that discourages smoke and vapors from leaving the grill to permeate the air in the cooking room.
SUMMARY OF THE INVENTION
[0010] According to the present invention, a grill has top and bottom cooking surfaces with the top cooking surface movable upward to load the grill with food and movable downward onto the food and bottom surface to cook the food. Different surface cooking zones may be heated individually to accommodate the amount and type of food. The top surface is lowered and pressed onto the food at a preselected pressure to provide positive contact with the food. Heated marinade and marinade vapor flow through openings or grooves in the cooking surfaces to steam the food and render fat for removal to a grease trough.
[0011] It is an object of the invention to provide a grill that can cook foods quickly without destroying the flavor or drying out the meat. This object is achieved by top and bottom cooking surfaces that heat food from the top and bottom simultaneously while steaming the food with its own juices or with a marinade to keep the food moist. It is a feature of the invention that the top and bottom cooking surfaces move, one relative to the other, to contact the food to directly heat the food.
[0012] It is an object of the invention to provide a grill that decreases the fat content of the cooked meat while retaining moisture and flavor without increasing refrigerator space required. This object is achieved by forcing steam or marinade through the meat to render the fat and drain the rendered fat as the meat cooks. It is feature of the invention that marinade is added at the time of cooking thereby eliminating the need marinating the meat in a refrigerator. Another feature of the invention is that meat can be cooked from a frozen state without thawing prior to placing it on the grill thereby reducing the need for refrigeration.
[0013] Another object of the invention is provide a way to for the marinade to completely penetrate the cooking food to impart uniform flavor and moisture. This object is achieved by introducing the marinade through openings in the top cooking surface. A feature of the invention is a series of passageways and openings in the top member for dispersing the marinade. An advantage of the openings in the top member is that steaming marinade is forced through the meat from both the top and bottom for thorough flavoring and cooking.
[0014] Another object of the invention provide a grill that captures rendered fat for safe and easy removal. This object is achieved by a trough along the front edge of the bottom member. A feature of the trough is that it is large enough for collecting cooking debris. An advantage of the trough is that it can be outfitted with a drain to removed grease and debris as it is generated thereby providing a clean working environment at all times and greatly reducing hazards associated with hot grease.
[0015] Still another object of the invention provide a simple method of removing cooking debris from the surface of the grill after each use. This object is achieved with tiltable top and bottom cooking surfaces. The rear of the bottom cooking surface can be raised to allow debris and cleaning solution to quickly drain. The top cooking surface pivots from a horizontal position for cooking to a vertical position for cleaning.
[0016] Yet another object of the invention is top provide a venting system that discourages smoke and vapors from leaving the grill to permeate the air in the cooking room. This object is achieved by several vent tubes placed about the periphery of the top member of the grill. Individual vent tubes on each side of the grill feed into a larger tube. The four larger tubes feed into a main exhaust tube that has a fan inside to create suction in the several vent tubes. The tubes has some flexibility so that they can flex when the top member moves up and down, and when the top member is tilted for cleaning. A feature of the vent system is that the main exhaust tube can be vented to the outside or vented inside through an activated charcoal filter.
[0017] These and other aspect, objects, features and advantages of the present invention will become more apparent from a study of the detailed description of the invention and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF DRAWINGS
[0018] [0018]FIG. 1 is a diagrammatic front view of a preferred embodiment of a grill according to the present invention.
[0019] [0019]FIG. 2 is a diagrammatic right side view of the grill of FIG. 1 with the grill open to receive food to be cooked.
[0020] [0020]FIG. 3 is a diagrammatic right side view of the bottom portion of the grill with the bottom cooking surface tilted.
[0021] [0021]FIG. 4 is a diagrammatic right side view of the bottom portion of the grill illustrating the marinade cup and grease through.
[0022] [0022]FIG. 5 is a diagrammatic top view of the top portion of the grill illustrating the pivot bar.
[0023] [0023]FIG. 6 is a diagrammatic top view of the bottom cooking surface illustrating the embedded cooking elements.
[0024] [0024]FIG. 7 is a diagrammatic bottom view of the top cooking surface illustrating the embedded cooking elements.
[0025] [0025]FIG. 9 illustrates the control panel for the grill.
[0026] [0026]FIG. 10 is a diagram of a ventilation system for the top member of the grill.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] Referring to FIGS. 1 - 3 , a grill 10 for cooking food contains a frame which supports a bottom member 12 and top member 14 each of which contains a cooking surface. The frame preferably has a set of legs 16 for supporting the bottom member 12 and a set of vertically extending, telescoping posts 18 for supporting the top member 14 . Preferably, the posts have lockable wheels 20 for moving the grill about, and also have height adjustment and leveling devices. A hood or canopy 15 may be attached at the top of posts 18 . Stainless steel is preferred for construction of the grill but other metals can be used that are corrosion resistant and have a clean appearance.
[0028] One or more jacks 22 have one end attached to the legs or to a cross member attached to the legs, and has the other end attached to the bottom cooking surface or to a brace or bracket attached to the bottom cooking surface. The jacks 22 operate to raise the back edge of the bottom cooking surface relative to the front edge to cause grease and liquid to drain from the bottom cooking surface. The jacks 22 may be hydraulic with the cylinder end attached to the legs and the piston end attached to the bottom cooking surface. Alternatively, jacks 22 cam be solenoids or electric motors that raise and lower the rear edge of the bottom cooking surface relative to the front edge of the bottom cooking surface. An electric motor could work in conjunction with a gear rack that raises and lowers to operate the bottom cooking surface. Power controls 24 for the jacks 22 a may be located on the frame below the bottom member 12 . In the case of hydraulic jacks, controls 24 would include a pump and hoses for supplying pressurized fluid to the jacks along with appropriate manual switches and controls for an operator to turn the pump on or off and to raise or lower the bottom member. A manual control panel 26 for the grill may be located on the frame below the bottom member 12 above the power controls 24 on the left side of the grill. Along its front edge, bottom member 12 is preferably hingedly connected to the frame so that bottom member 12 pivots or partially rotates about the hinged connection point. For efficient cleaning, the rear of the bottom member is raised to encourage grease runoff and to make the rear more accessible to the operator.
[0029] Referring to FIGS. 1 - 6 , the bottom member 12 has a bottom periphery bounding the bottom cooking surface 28 that is slightly upturned to prevent liquids on the cooking surface 28 from spilling over the edge of the bottom member. Preferably, bottom cooing surface has a larger area than top cooking surface 30 which allows vapors from cooking escaping from between the cooking surfaces to naturally turn upward instead of being forced outward into the path of an operator.
[0030] Bottom cooking surface 28 preferably has a cylindrical marinade cup 32 formed therein for holding a marinade used to moisturize and flavor the food that is cooking. The marinade cup preferably extends below the bottom member 12 , has a bottom cap that is removable and has its own heating element 34 . It may be fitted with a tube for the introduction of the marinade allowing easy measuring and changing of the mixture according to the food to be cooked. The removable cap can be removed to form a drain that is useful for directing debris and cleaning solutions to a collection station when the bottom surface is cleaned.
[0031] The marinade cup 32 maybe a separate cup member positioned in a depression or opening in the bottom cooking surface or it maybe formed from a depression formed in the bottom cooking surface. Preferably, the cup 32 is a threaded member that screws into a threaded opening in the bottom member or screws onto a threaded tail pipe that opens to the bottom cooking surface. The idea is to have a cup that is removable for cleaning and to have a bottom member that is relatively easy to manufacture. As an alternative to threaded members, other methods for coupling members together may be used, such as the couplings used for hydraulic and pneumatic lines which are easy to connect without leaks.
[0032] Referring to FIG. 6, the bottom cooking surface 28 contain a plurality of grooves 36 that terminate at a grease collection trough 38 . The grooves 36 preferably run laterally from back to front with a varying depth slanting bottom that acts a drain for directing grease collecting in the grooves 36 to the grease collection trough 38 . The grease collection trough 38 preferably borders the front of the cooking surface so that grease drains from the cooking surface to the through 38 and is direct ed to a drain 40 that directs the collected grease into a container or grease trap in the plumbing system for the building for appropriate disposal or recycling.
[0033] Both the top and bottom cooking surfaces may be heated with heating elements 42 , 44 imbedded beneath the cooking surfaces. Such heating elements may be strips of nichrome heater wire or other electrical heating element, or heat tubes for distributing steam, water, air or other fluid for heating. Nichrome wire could be embedded in the channels in the top and bottom members or attached to the rear of the cooking surfaces. Similarly, conduits for fluid could be embedded in the channels in the top and bottom members or attached to the rear of the cooking surfaces. The preferred arrangement for cooking with a filled grill is to have the heaters 42 , 44 (FIGS. 6 - 7 ) spaced to uniformly heat the entire cooking surface so that food cooks uniformly. To make a single grill more versatile, the cooking surface can be divided into zones with each zone having a heating element 42 , 44 to heat a portion of the cooking surface as needed for the particular items to be cooked.
[0034] The heaters may be arranged to heat the cooking surface uniformly, and may be controlled from control panel 26 to heat only specific portions or zones of the cooking surface as desired depending on the variety and amount of food to be cooked, or to heat different portions or zones of the grill at different temperatures to cook more than one food at a time. The control panel 26 regulates the temperatures by controlling electric current or heating fluid flow to the top and bottom members. To heat in zones, the wiring or tubing is laid in zones and controlled from control panel 26 accordingly. In the case of heated fluid, a manifold attached to or near the top member with a tube for each zone controlled by a solenoid would effectively control flow to regulate the temperature. While such laying in zones is a more expensive manufacturing process, it is desirable where the grill will be called upon to provide a variety of foods in small servings. Not only may the top and bottom cooking surfaces operate at different temperatures, but different portions of each can be operated at differing desired temperatures for different periods of time. Varying the cooking time by zones or portions of the grill cooking surfaces allows foods to be cooked as desired and takes into account the time required to load and unload the grill so that foods are not inadvertently overcooked.
[0035] Referring to FIG. 8, to solve the problem of uneven dispersement of the marinade, the top member is outfitted with a number of jets 46 to spray or drip marinade from the top onto the cooking food. The jets are arranged in zones or other pattern to compliment the heating pattern, and are controlled by a solenoid manifold in similar manner to the heating fluid. The marinade is pumped to the manifold by a pump from a reservoir 65 (FIG. 5) with sufficient pressure for the jets to provide a drip or spray as desired. An inlet tube 48 delivers marinade to the jets, or manifold where a manifold is used, while an outlet tube 50 discharges unused marinade. Outlet tube 50 is preferably fitted with a one way valve 52 to prevent fluid from back flowing. Fluid flows from inlet tube 48 through tubing for jets 46 and on to outlet tube 50 . To help build pressure to operate the jets, the one way valve 52 may be a solenoid operated valve. The jets and associated tubing are preferably embedded in the top member. Inlet tube 48 is removably connected to the embedded tubing. One way valve 52 and outlet tube 50 are also removably connected to the embedded tubing. The embedded tubing is easily cleaned by replacing the marinade with a cleaning solution followed by a rinsing solution.
[0036] Referring to FIG. 9, while the prior method of introducing marinade through grooves in the bottom member was superior to previous methods of cooking for speed and flavor, it produced a cooked product which was cooked and flavored more on the bottom than throughout the product because of the cooking occurring while loading and unloading the grill. The present method of introducing marinade from both the top and bottom produces a more uniformly flavored product, while the zone, temperature and time controls produce more uniform cooking to compensate for time spent loading and unloading the grill. The control panel 26 contains push buttons or other control mechanisms for opening 54 the grill and for closing 56 the grill. Push buttons 54 and 56 open and close the grill by energizing jack 58 to raise and lower top member 14 . Alternatively, the bottom member 12 may be raised to close the grill and lowered to open the grill, but moving the top member up or down is preferred because moving the bottom member would cause the bottom member to be at an inconvenient height when either open or closed thereby increasing operating complexity requiring a worker with increased skill to operate the grill. As the top member is raised and lowered, its telescoping legs extend and retract.
[0037] Control panel 26 also has a number of preset buttons 60 which can be programmed for temperature using keypad 62 , for pressure using keypad 64 , for cooking time using timer keypad 66 , and for cooking zone using heat zone keypad 68 . Lights 70 , 72 illuminate to indicate that the top and bottom cooking surfaces, respectively, are at the desired temperature. Gauges 74 and 76 show top and bottom cooking surface temperatures in actual degrees referenced against the desired temperature. Each preset button 60 has an indicator light associated with it to indicate that the preset is being used. Temperature can be controlled by varying the time the heating elements are energized during the cooking cycle time. Cooking cycle time begins after the desired temperature is initially reach and when the desired pressure is obtained after moving the cooking surfaces towards one another. Cooking time for each particular food requires only a few trials. Cooking times for various foods are provided with instructions for the grill. To prevent over cooking, cooling tubes or passageways can run through the top and bottom members to quickly cool the cooking surfaces using water or a recyclable coolant. While artificially cooling the cooking surfaces increases energy demand, it allows food to remain on the grill while a dish is assembled thereby reducing the total area required to prepare a meal.
[0038] Referring to FIG. 5, the top member 14 is pivotally connected to its posts so that it can pivot from a horizontal position for cooking to a vertical or nearly vertical position for cleaning. Such pivotal movement may be facilitated by mounting the top member on a pivot rod 60 or pivot pins. Such a pivot rod 60 could extend through top member 14 and terminate in a bracket 61 on either side of the top member. A locking pin 63 fits through openings in the rod 60 and bracket 61 to lock top member in a horizontal position for cooking, or a vertical position for cleaning. With pin 63 removed, top member 14 can be pivoted manually. Brackets 61 are attached to the telescoping posts. Jacks to raise and lower top member 14 can also be attached to the brackets 61 and to the lower portion of the frame.
[0039] As an alternative to jacks, stepping motors may be used to raise and lower the top member. The stepping motors could be mounted on the stationary portion of the posts with gear teeth to engage teeth on the telescoping portion of the posts. Or, stepping motors could be mounted on the brackets supporting the top member and used with stationary posts to raise and lower the top member. Stepping motors have the advantage of being able to control the pressure exerted by the top member on the food. Such pressure could be controlled using the motor torque of motor current which indicates the pressure exerted.
[0040] Referring to FIG. 10, an exhaust system 77 is attached about the perimeter of the top member to exhaust smoke and cooking fumes. A series of vent tube 78 are detachably attached to the skirt of the top member 14 . Top member 14 is smaller in area than bottom member 12 so that smoke and fumes tend to rise about the periphery of top member 14 . The individual vent tubes 78 on each side of the top member connect to larger tubes 80 , 81 , 83 , and a similar tube on the rear (not shown). The larger tubes 80 , 81 , 83 connect to an exhaust tube 82 that has a fan 84 inside to create suction in vent tubes 78 . Tube 82 is preferably vented to the outside but may exhaust into an activated charcoal filter or the like and then recirculated in the room. Tube 80 is flexible to accommodate the up and down motion of top member 14 , and to accommodate the pivoting motion of top member 14 . Alternatively, or in addition, vent tubes can be added to the bottom member 12 , however, top venting is preferred as it takes advantage of the natural tendency of smoke and fumes to rise.
[0041] Operation of the present invention results in meat that is moist and tasty. To cook, the top cooking surface is raised, and selections for cooking zone, temperature, pressure and cooking time are selected using the keypads on the control panel. Marinade is added to the reservoir if marinade is to be used. The cooking surfaces and cup are brought to cooking temperature and the meat or other food is placed on the bottom cooking surface. Pushing the “down” button lowers the top surface. Pressure is increased to press the top surface against the food with a preselected pressure. Cooking is accomplished with heat from the top and bottom surfaces and from the heated marinade, marinade vapor and water vapor from the food. After cooking for a prelecteded length of time, the “up” button is pushed to raise the top surface and stop the heating. The food is ready and can be removed from the grill. Where the grill is equipped with a cool down cycle, the food can remain on the grill as platters of food are prepared.
[0042] The meat may be seasoned prior to cooking, seasoned with the marinade during cooking, or season as desired after cooking. The vapor injected into the meat during cooking liquefies the fat and replaces the fat which drains away to the collection trough. Meat is placed on the heated grill, and the top cooking surface is lowered and presses on the meat so that the vapor can tenderize it while flavoring it. After a predetermined cooking time, the top cooking surface is raised and the cooked meat is removed. Depending on the particular combination, different meats can be cooked together and vegetables can also be cooked at the same time. Meats using the same marinade can be cooked together although their cooking times may vary. Their cooking temperatures can be varied so that both cook in the same amount of time.
[0043] It can now be appreciated that an apparatus and method for cooking food quickly while keeping meat moist and tender has been presented. The apparatus includes a bottom member having a bottom member with a bottom cooking surface, means for controllably heating the bottom cooking surface, a top member with a top cooking surface. The top cooking surface is vertically movable relative to the bottom cooking surface between an open position for loading the apparatus with food to be cooked and a closed position for cooking the food.
[0044] The method for cooking food comprises heating the bottom cooking surface of the bottom grill member to a first predetermined temperature and heating a top cooking surface of the top grill member to a predetermined temperature. The temperatures may be the same or different, and different zones of the cooking surfaces may attain different preselected temperatures. If not already raised, the next step is raising the top surface vertically to the open position and loading the bottom cooking surface with food. The food may be pre-seasoned with spices and seasonings, but it is not necessary to do so. The step of adding a marinade of spices, seasonings and juices to the marinade reservoir will cause sufficient seasoning of the food. After loading the grill with food, the top cooking surface is vertically lowered to the closed position. Press cooking requires forcing the top surface down into contact with the food at a pressure sufficient to confine the food between the cooking surfaces so that the fat can be rendered and the marinade permeated throughout the food.
[0045] The method includes heating the marinade creating a marinade vapor, driving the marinade and marinade vapor into the food for rupturing bonds between food fibers and permeating the food replacing fat and juices with the marinade, and draining the fat and juices to the grease collection trough. After cooking the food for a predetermined length of time, the top surface is raised to the open position, and the food is removed.
[0046] While the invention has been described with particular reference to the preferred embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements of the preferred embodiments without departing from invention. For example, pivot pin for the top member that extends the length of the top member can be replaced by a pair of short pins, one on each end. In addition, many modifications may be made to adapt a particular situation and material to a teaching of the invention without departing from the essential teachings of the present invention. As is evident from the foregoing description, certain aspects of the invention are not limited to the particular details of the examples illustrated, and it is therefore contemplated that other modifications and applications will occur to those skilled in the art. For example, the bottom grill member may be movable while the top grill member remains stationary, and the bottom member may be equipped with an exhaust system. It is accordingly intended that the claims shall cover all such modifications and applications as do not depart from the true spirit and scope of the invention. | A grill has top and bottom cooking surfaces with the top cooking surface movable upward to load the grill with food and movable downward onto the food and bottom surface to cook the food. Different surface cooking zones may be heated individually to accommodate the amount and type of food. The top surface is lowered and pressed onto the food at a preselected pressure to provide positive contact with the food. Heated marinade and marinade vapor flow through openings or grooves in the cooking surfaces to steam the food and drive fat out for removal to a grease trough. The marinade replaces fat and natural juices producing a relatively low fat cooked meat. | 0 |
BACKGROUND OF THE INVENTION
The present invention relates to the field of percutaneous transluminal angioplasty generally, and more particularly to a stent delivery system for producing variable post-deployment stiffness characteristics in stents which have uniform pre-deployment radial stiffness.
The use of balloon catheters for high pressure dilation of occluded blood vessels is well known. Balloon coronary angioplasty, for example, is often used as an alternative to open-heart coronary bypass surgery. In a typical balloon angioplasty procedure, a guiding catheter is percutaneously introduced into the cardiovascular system of a patient through the femoral arteries by means of a conventional Seldinger technique and advanced within a patient's vascular system until the distal end of the guiding catheter is positioned at a point proximal to the lesion site. A guidewire and a dilatation catheter having a balloon on the distal end are introduced through the guiding catheter with the guidewire sliding within the dilatation catheter. The guidewire is first advanced out of the guiding catheter into the patient's vasculature and is directed across the arterial lesion. The dilatation catheter is subsequently advanced over the previously advanced guidewire until the dilatation balloon is properly positioned across the lesion. Once in position, the expandable balloon is inflated to a predetermined size with a radiopaque liquid at relatively high pressures, usually in the range of about 6-12 atmospheres. Balloon expansion radially compresses the atherosclerotic plaque of the lesion against the inside of the artery wall and thereby dilates the lumen of the artery. The balloon is then deflated to a small profile so that the dilatation catheter may be withdrawn from the patient's vasculature and blood flow resumed through the dilated artery. As should be appreciated by those skilled in the art, while the above-described procedure is typical, it is not the only method used in angioplasty.
Balloon angioplasty sometimes results in short or long term failure. That is, vessels may abruptly close shortly after the procedure or gradual restenosis may occur up to several months afterward. To counter the tendency of recurrent vessel occlusion following angioplasty, implantable intravascular prostheses, commonly referred to as stents, have emerged as a means by which to achieve long term vessel patency. Stated simply, a stent functions as permanent scaffolding to structurally support the vessel wall and thereby maintain luminal patency. Stents are typically small tubular metallic structures.
Since the present invention is directed to an improved stent delivery system, it may prove useful to briefly describe the components and operation of a typical stent delivery system. Such systems typically include a balloon catheter, a stent which is mounted on the balloon, and a delivery sheath which surrounds the stent-delivery catheter. Initial angioplastic dilation of the lesion produces a residual lumen large enough to accept the stent delivery system. The guiding catheter used to perform the initial dilation is typically left in place in the patient and reused during the stent implantation procedure. The stent-delivery catheter is routed through the guiding catheter to a position in which its distal end is disposed substantially coextensively with the distal end of the guiding catheter and immediately proximate of previously expanded lesion.
Once properly positioned relative to the guiding catheter, the stent-carrying catheter is extended from the distal end of the guiding catheter until the stent spans the previously dilated lesion. The delivery sheath which is slidable relative to the delivery catheter, balloon and stent, is then withdrawn into the guiding catheter to expose the balloon and stent. The delivery catheter is then supplied with a pressurized fluid, which expands the balloon and associated stent to a desired diameter sufficient to exceed the elastic limit of the stent. The stent thus comes in contact with, and permanently supports, the wall of the vessel. The delivery catheter balloon is then deflated and the delivery catheter and guiding catheter are withdrawn, leaving the expanded stent supporting the vessel lumen.
Prior art stent delivery systems have generally proven to be effective. However, in the treatment of certain vascular diseases, it is desirable to have a stent with reinforced end rings or regions of relatively high stiffness at one or both ends of the stent. Such a stent is required to successfully treat ostial vessel diseases such as in the renal vessels. The ostium of the renal vessels requires a stent with an end region which possesses relatively high resistence to radial compression. This is due to the close proximity of the aortic wall muscles which have a tendency to contract around the renal ostium and which may cause radial collapse of a dilated vessel implanted with a non-reinforced stent. Vessels such as the coronary sinus, ostial RCA, and ostial left main, and other vessels where the ostium is surrounded by tissue which produces high radial forces, may also be beneficially treated by a stent with a reinforced or high stiffness end region. Stents of this type are commonly referred to as variable stiffness stents. The present invention satisfies these and other needs.
SUMMARY OF THE INVENTION
The present invention provides a stent delivery system that utilizes a conventional dilatation catheter, equipped with a novel polyurethane inflation balloon, in combination with any one of several types of commercially available stents. The system creates a stent which would otherwise have uniform radial stiffness in its expanded state into a stent having comparatively high stiffness end portions or reinforced rings in its expanded state. The catheter of the present invention includes an elongated body having proximal and distal ends and an inflation balloon disposed proximate to the distal end of the catheter. The catheter further includes a port in its proximal end and an inner lumen between the port and the balloon. The port is in fluid communication with the balloon and supplies high pressure radiopaque fluid to the interior cavity of the balloon for balloon inflation. The balloon of the present invention can be formed from polyurethane material which possess a high coefficient of friction when bearing against metallic materials. The balloon includes a cylindrical working portion with end portions of selected taper. The balloon is designed to have relatively high axial compliance in comparison to its radial compliance. Stents suitable for use with the delivery system of the present invention include all stents having a closed cellular structure in their expanded state.
The stent delivery system of the present invention is used with a stent of sufficient length such that the ends of the stent overhang the tapered portions of the balloon when the stent is centered on the balloon. The stent delivery system of the present invention is able to utilize balloon axial growth under high pressure and the high frictional resistance of the selected polyurethane material to produce substantial longitudinal expansion over a center portion of the stent, while the overhanging ends of the stent experience minimal longitudinal expansion. The central portion and end portions of the stent experience the same degree of radial expansion by the end of the expansion process. The differential in the rate of longitudinal expansion produces comparatively low cell density in the expanded center portion of the stent and comparatively high cell density in the expanded end portions of the stent. The comparatively high cell density in the end portions corresponds to a comparatively higher degree of radial stiffness.
Other features and advantages of the present invention will become apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, partially in section, depicting one embodiment of the stent delivery system of the present invention.
FIG. 1A is a cross-sectional view taken along line 1 A— 1 A depicting the inner and outer tubular members of the catheter shown in FIG. 1 .
FIG. 2 is a cross-sectional view of one particular embodiment of a balloon made in accordance with the present invention.
FIG. 2A is a partial cross-sectional view of one particular embodiment of a balloon made in accordance with the present invention.
FIG. 3 is a partial sectional view of the distal end of the stent delivery system shown in FIG. 1 depicting the catheter balloon, in its folded configuration, with a stent mounted thereon.
FIG. 4 is a partial sectional view of the distal end of the stent delivery system shown in FIG. 1 depicting the catheter balloon, inflated at low pressure, with a stent mounted thereon.
FIG. 5 is a partial sectional view of the distal end of the stent delivery system shown in FIG. 1 depicting the catheter balloon, inflated at moderate pressure, with a stent mounted thereon.
FIG. 6 is a partial sectional view of the distal end of the stent delivery system shown in FIG. 1 depicting the catheter balloon, inflated at maximum pressure, with a stent mounted thereon.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention has a novel construction of an inflation balloon designed to utilize the properties of selected polyurethane materials to produce a balloon with high axial compliance, moderate radial compliance, and high adherence to metallic substrates. Catheter balloons are usually classified in terms of radial compliance, with balloons typically being classified as having low, medium, or high compliance. Radial compliance, as the term is used in the art, refers to the increase in a balloon's diameter over the balloon's nominal diameter at low inflation pressure. Balloon compliance is primarily a function of balloon material. Catheter balloons are most commonly made from polyester, polyamide, and polyolefin materials. Balloons made from polyester materials typically exhibit low compliance. Low compliance balloons generally increase in diameter at the rate of 0.1 mm per atmosphere pressure. Balloons made from polyamide materials typically have medium compliance. Medium compliance balloons increase in diameter at the rate of about 0.2-0.3 mm per atmosphere pressure. Balloons made from Polyolefin materials typically exhibit the highest degree of compliance. High compliance balloons increase in diameter at a rate of about 0.3-1.0 mm per atmosphere pressure.
Axial compliance, or the tendency of the balloon to elongate along the balloons longitudinal axis, has heretofore not been considered a significant factor affecting stent deployment. Polyester, polyamide, and polyolefin materials all exhibit a very low coefficient of friction, in the range of 0.30 to 0.40, when bearing against a metallic structure such as a stainless steel stent. Although balloons produced from the above mentioned materials are effective in producing radial expansion of a stent, they usually do not adhere very well to metallic stents and therefore merely slip underneath the stent as they grow axially during expansion. Thus, these materials have little or no effect on the post expansion length of metallic stents.
Recent work with polyurethane materials has revealed that balloons constructed of this material can be tailored to have medium radial compliance in the range of 0.3 mm diametrical growth per atmosphere pressure and relatively high axial compliance in the range of 0.4 mm longitudinal growth per atmosphere pressure. In addition, polyurethane materials have demonstrated strong surface adhesion to metal substrates. Polyurethane materials have demonstrated coefficients of friction in the range of about 0.4 to 0.7 in bearing against metallic substrates such as stainless steel. When a metallic stent is mounted on a polyurethane balloon, the balloon material adheres much better to the stent than other polymeric materials and thereby forces the stent to grow axially as well as radially, during expansion.
The ability of polyurethane materials to force a stent to grow axially may be used to advantage in forming a variable stiffness stent. By selecting a stent with an overall length such that the ends of the stent extend axially outwardly over the tapered portions of the catheter balloon, a differential in the rate of axial growth of the stent may be created. More specifically, at low to medium inflation pressure the center portion of the stent which is in contact with the cylindrical working portion of the balloon grows axially as the balloon is expanded. Stent axial growth in the range of 0.4 mm per atmosphere pressure is achievable with Multilink type stents. As a result, the expanded cells of the center portion of the stent are more widely spaced than those of the end portions, which due to their position overhanging the tapered portions of the balloon, experience little or no axial growth and consequently have closer cell spacing at full expansion. The closer cell spacing at full expansion provides the end portions of the stent with a higher degree of radial stiffness in comparison to the radial stiffness of the center portion. Stents expanded with polyurethane balloons have an increased end stiffness of about 10% over the stiffness of the center portion of the stent.
The catheters used in the present invention are most conveniently constructed as over-the-wire balloon catheters of conventional form for use in angioplasty, except that the balloon has an exterior working surface of high frictional resistance. However, it should be appreciated that the present invention may also be applied to fixed wire catheters, rapid exchange type catheters, and other non over-the-wire catheters.
FIG. 1 illustrates a stent delivery system that embodies features of the invention. Generally, the delivery system comprises a catheter 10 , which includes an expandable member, such as an inflatable balloon 30 , and a stent 20 mounted on the balloon 30 . Referring now to FIGS. 1 and 1A, the balloon catheter 10 includes an elongated outer tubular member 14 and an elongated inner tubular member 15 coaxially disposed within the outer tubular member 14 . The inner tubular member 15 has an inner lumen 16 adapted to receive a guidewire 17 . The inner tubular member 15 and the outer tubular member 14 define an annular lumen 18 which directs inflation fluid to the interior of the balloon 30 . The inner tubular member 15 is equipped with radiopaque markers 19 , which are positioned radially in line with ends of the mounted stent 20 , to aid a vascular surgeon when placing the catheter 10 within a blood vessel. The dimensions of the intravascular catheter for use in the present invention will generally follow the dimensions of intravascular catheters used in angioplasty procedures in the same arterial location. For example, in angioplasty procedures involving the coronary arteries, catheters are typically about 150 cm long with an outer diameter of about 0.89 mm. Materials for and methods of manufacturing such catheters are well known to those skilled in the art.
Referring now to FIG. 2, the balloon 30 has an elongated cylindrically shaped working portion 32 . On opposing ends of the working portion 32 are the tapered portions 36 and 38 . A shoulder 35 is defined by the junction between the working portion 32 and the tapered end portions 36 and 38 . The skirts or waists 40 and 42 are provided respectively on the small diameter end of the tapered portions 36 and 38 . In circumstances where greater frictional force is needed for a stent to expand axially, the working portion 32 may be optionally equipped with a plurality of integrally formed ridges 34 which serve to form points of high frictional resistance between the balloon and a metallic stent, as shown in FIG. 2 . The same purpose may also be achieved by adding a pebble grain texture 31 to the working portion of the balloon 32 , as shown in FIG. 2 A. As illustrated in the drawings, the working portion 32 and the tapered portions 36 and 38 have essentially the same wall thickness. By keeping the wall thickness of the tapered portions essentially the same as that of the working portion, the tapered portions, when subjected to high pressure, will expand inline with the working portion. The skirts 40 and 42 need not, and generally do not, have the same wall thickness as the working section 32 and the tapered sections 36 and 38 . The distal skirt 40 of the balloon 30 is attached to the distal end of the inner tubular member 15 of the catheter 10 . The proximal skirt 42 is attached to the outer tubular member 14 . Suitable means for attaching the skirts 40 and 42 to the catheter 10 include heat welding, solvent welding, ultrasonic welding, and adhesive bonding. Several types of polyurethane are suitable for making the balloons for use in the present invention. The type of polyurethane chosen is dependant on the amount of axial elongation desired at the center portion of the stent and the desired maximum inflation pressure. The coefficient of friction of the polyurethane balloon is in part a function of the balloon hardness. Generally, polyurethanes with a surface hardness of about 75 durometer (Shore A) to about 80 durometer (Shore D) are preferred. The maximum inflation pressure of the balloon is function of the balloon's geometry, wall thickness, and of the material's tensile strength. Polyuethanes typically have an ultimate tensile strength within a range of about 4500 psi to about 9000 psi, which is sufficient for the production of high pressure balloons. Thermoplastic polyurethanes, such as those synthesized from d-isocycinates, are particular well suited for making balloons for use in the present invention. One example of a suitable commercially available polyurethane is PELLETHANE 2633-75D, which is sold by the DOW Chemical Corporation.
The balloon of the present invention may be made using any conventional process, such as blow molding or extrusion. The actual dimensions of the balloon 30 will depend upon the particular dilation procedure for which the balloon and catheter are to be employed. In general, when the balloon is for angioplasty usage, the external diameter of the balloon will be of the order of about 1 mm to about 25 mm. The overall length of the inflated portion will be on the order of about 10 mm to about 150 mm. The walls of the balloon will have an average thickness of about 0.01 mm to about 0.2 mm depending in part on the pressures to which the balloon will be inflated. The dimensions and methods given above are exemplary only and are not to be construed as limiting.
The stent employed with the device of the present invention should ideally be formed of a metallic material and have a closed cell structure in its expanded state. Co-owned U.S. Pat. No. 5,514,154 to Lau et al., U.S. Pat. No. 5,569,295 to Lam, U.S. Pat. No. 5,591,197 to Orth et al., U.S. Pat. No. 5,603,721 to Lau et al., U.S. Pat. No. 5,649,952 to Lam, U.S. Pat. No. 5,728,158 to Lau et al., and U.S. Pat. No. 5,735,893 to Lau et al. describe suitable stents, and these patents are hereby incorporated herein in their entirety by reference hereto. The above list is exemplary and is not inclusive. Other stent designs and designs utilizing non-metallic materials are also suitable.
Referring now to FIGS. 3-6, the stent delivery system of the present invention is used as follows. With reference to FIG. 3, in order to create high stiffness end portions, the stent 20 is selected such that the length of the stent is greater than that of the working section 32 of the balloon 30 . The stent is then positioned on the folded balloon 30 such that the ends of the stent overhang the respective tapered portions 36 and 38 of the balloon. In most applications, it is desirable to center the stent on the folded balloon, as is illustrated in FIG. 3, whereby the stent's proximal and distal ends equally overhang the respective tapered portions of the balloon. However, in some situations where it is desired to create a stent with only one high stiffness end, a stent may be positioned such that only one end overhangs a tapered portion of the balloon. Once the stent 20 is positioned on balloon 30 , the stent is crimped into place. There are many varieties of suitable crimping tools known to those skilled in the art which can be utilized to crimp the stent into place.
Once the stent 20 has been positioned and crimped onto the catheter balloon 30 , the stent-bearing catheter 10 is then advanced through a body lumen to a lesion site by conventional medical techniques. Generally, a guiding catheter is first placed in the patient's vasculature and advanced through the body lumen to a point proximal of the lesion site. A guidewire 17 is then advanced through the guiding catheter and is advanced out of the guiding catheter across the lesion site to a point distal of the lesion. The catheter-stent assembly 10 is subsequently advanced over the guidewire until the stent 20 is positioned across the lesion site. The balloon 30 of the catheter 10 is then inflated, whereby the stent 20 begins to expand.
Referring now to FIG. 4, initial inflation of the balloon at low pressure, corresponding to a range of 2 - 4 atmospheres, generates a small degree of radial and axial stent expansion. As a result of this low pressure inflation, the stent forms a discrete center portion 22 which is substantially coextensive with the working portion of the balloon 32 . In addition, the stent forms discrete proximal and distal tapered portions 26 and 24 respectively. The tapered portions 26 and 24 of the stent 20 substantially conform to the tapered portions 38 and 36 of the balloon 30 . At this point only minimal expansion of the stent's cellular structure has occurred.
Referring now to FIG. 5, at moderate pressure, in the range of 6 - 8 atmospheres, the balloon extends longitudinally. Consequently, due to the high frictional resistance between the balloon and the stent, the center portion of the stent 22 expands longitudinally essentially the same amount as the working portion 32 of the balloon 30 . As shown in FIG. 5, the cell density 28 of the stent in the center portion 22 has decreased relative to the cell density 29 of the end portions 24 and 26 which have experienced minimal longitudinal expansion.
Referring now to FIG. 6, at a maximum pressure of about 15 atmospheres, the tapered end portions 36 and 38 of the balloon 30 , expand fully with the working portion 32 , whereby the end portions 26 and 24 of the stent 20 are fully expanded radially to the same diameter as the center section 22 . As the end portions 24 and 26 are deformed upwardly, a minimal amount of longitudinal expansion occurs. Thus, at the end of the expansion process, the end portions 24 and 26 of the stent have a cell density relatively higher than the center portion 22 . Thus, the differential in axial expansion between the center section 22 and the end portions 24 and 26 of the stent 20 effectively forms a stent with high cell density and stiffness at the end portions 24 and 26 .
It will be appreciated that a new device and method for creating a variable stiffness stent has been presented. While only the presently preferred embodiment has been described in detail, as will be apparent to those skilled in the art, modifications and improvements may be made to the device and method disclosed herein without departing from the scope of the invention. Accordingly, it is not intended that the invention be limited except as by the appended claims. | A stent delivery system is provided which incorporates a polyurethane balloon which exhibits a high coefficient of friction with respect to metallic substrates. Through the process of stent expansion, the delivery system creates a differential in the rate of axial growth of metallic stents. The differential in growth causes a center portion of the stent to experience greater axial expansion than respective end portions. The stent has the lower axial expansion of the end portions results in a stent having end portions of comparatively higher radial stiffness than the corresponding center portion of the stent. | 0 |
CROSS-REFERENCE TO RELATED APPLICATION
This application claims the benefit of U.S. Provisional Application No. 60/569,793, filed May 10, 2004, the entirety of which is hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates in certain embodiments to high density, nontoxic articles such as shots used as projectiles in shotgun shells and the like.
2. Description of the Related Art
Lead has traditionally been used as a material for shot pellets for hunting, especially hunting for birds, because of its high density and low melting point that lend itself to ease of manufacture and highly predictable ballistic characteristics. The majority of these pellets fall to the ground without hitting the target. Some of them settle on the bottom of the wetlands and lakes. Over time the spent lead pellets accumulate to a point that some waterfowl have shown signs of lead poisoning because they ingested lead pellets while in search of food and also the grit to assist in digestion of the food. This has led to the ban of lead shot pellets for waterfowl hunting in the U.S., Canada, and other countries.
Because of market demand, considerable effort has been devoted to searching for a viable lead substitute that can be economically produced and at the same time possesses the predictable ballistic characteristics of the lead shot pellet, such as uniform pattern density with a wide variety of shotgun chokes and barrel lengths, and uniform muzzle velocities with various smokeless powders. There are no comparable metals that possess all of the desired characteristics. Those metals that are somewhat close to lead in density are not satisfactory substitutes as a result of other drawbacks, such as high cost, radioactivity, high melting point, or other properties.
Various approaches have been proposed to formulate a mixture of metals and in some cases using polymers. Additionally, various methods have been attempted to process these mixtures for the final product. Despite these prior efforts, the products made according to these materials and processes have some shortcomings as discussed below.
Steel was selected as the most practical substitute, based on methods of production, cost, ballistics, and its nontoxic nature. However, steel shot pellets have a density of about 7.5 to about 8.0 g/cm 3 as compared to lead alloy shot pellets which have a density of about 10 to about 11 g/cm 3 . Density differences between shots of the same gauge will perform differently in the trajectory and firearm recoil when powered by the same charge. Additionally, steel shot pellets do not deform, and have a definite tendency toward center density regardless of choke. Especially for the large size steel shots, they do not pattern perfectly from tightly choked barrels because such charges do not swage down well to flow smoothly through the choke. The wedging and bridging were believed to be the reasons in an overly choked condition. To compensate for the density difference, hunters have been using two or three larger gauge shot pellets in the shotshell load. Unfortunately, the larger shot pellet size reduces the total number of shot pellets that can be loaded in the predefined shotshell case; this in turn deteriorates the pattern density. Because of the hardness of the steel shot pellet, it is required to have a thicker and harder plastic to protect the bore from the ravages of the steel shot pellets. This requirement further reduces the case volume available for the shot pellets. In order to increase the case volume to accommodate more steel shot pellets, the wad has been redesigned to eliminate the collapsible leg section.
The larger diameter steel shot pellets suffer more disadvantages. The larger steel shot pellet will lose velocity quicker than the smaller high density shots. Also, the steel shot pellet will not penetrate as well because of its larger frontal section. This, coupled with low density, loss of velocity due to drag force, and the inferior pattern density previously mentioned, have resulted in an increased number of crippling shots. Hunters have been known to reduce the range over which he or she will try to take game by as much as 25%. Also, because the steel shot pellets lose momentum over the flight range, they require a lengthened lead. Some manufacturers have employed special powder to drive up the muzzle velocity, but these powders also increase the barrel pressure which causes safety concerns. All of these issues cause a great deal of confusion and frustration to the hunting community.
Nontoxic shot products currently in the market are either too hard or too soft, too frangible or too rigid, or too abrasive. Products that are too hard or too rigid damage the gun barrel and have a strong tendency to ricochet when hitting a hard surface. Products that are too soft tend to leave some rub off particles in the gun barrel and deform too much at firing and in flight, which causes deterioration in the shot pattern and final impact energy and energy transfer. It is also harder for a soft shot to penetrate the animal to make a clean kill. Products that are too frangible tend to crack during set back (firing), and in flight; this will cause drag in flight and cause the shot to lose momentum. It also tends to cause the shot to disintegrate upon impact, thus impeding penetration and causing the energy to not transfer onto the animal.
The majority of the prior nontoxic shots have not proved to be commercially viable primarily due to high equipment cost, high process operating cost, inferior density and hardness characteristics compared to lead and lead alloy.
SUMMARY OF THE INVENTION
One embodiment of the present invention is a nontoxic shot for various applications. The shot preferably contains tungsten, and may be a sintered nontoxic shot pellet for ammunition with high accuracy in specific gravity and tight tolerance in size. Preferably, the shot is made using a mechanical agitation or tumbling process, to produce precise control over the size and sphericity of the shot, while also maintaining a high density and relatively low hardness. In one embodiment, the shot has a density of at least 10 g/cm 3 , and a Vickers hardness HV of about 230 or less.
Another embodiment of the present invention is a composition for a shot that varies throughout the cross section of the shot, and also in a precise manner. In one embodiment, a sintered shot has a predetermined transition of density and transition of hardness reading at different layers/depths of the shot. More preferably, a sintered high density shot is provided containing tungsten and having a predetermined combination of size tolerance, accuracy in each layer's density, and accuracy in aggregate density. In one example having three distinct layers, the surface hardness measured at near the shot's generally spherical surface measures about HV 200 or lower, more preferably about HV 100 or lower, and the core hardness measures about HV 200 or lower, more preferably about HV 110 or lower.
After a shot is formed, a tin coating may optionally be plated or hot dipped on the outer surface of the shot.
In accordance with preferred embodiments of the invention, multiple variations in material can be used to form a spherical shot. For example, a single layer shot may be formed, with or without an additional tin coating. In another example, a dual layer shot may be formed, having a core and an outer layer, with or without an additional tin coating on the outer surface of the outer layer. In another example, a three layer shot may be formed, having a core, an intermediate layer, and a surface layer. This three layer shot may have varying hardness and/or density between the layers, and may or may not have a tin coating on the outer surface of the surface layer.
In one embodiment, an ammunition projectile is provided comprising a first component comprising tungsten, and a second component comprising at least one of copper, iron and nickel. The projectile has a density of at least 10 g/cm 3 and a Vickers hardness HV of about 230 or less. In a preferred embodiment, the ammunition projectile comprises primarily tungsten, and is uniformly layered and sintered. The second component may comprise copper, iron and nickel. The projectile may be made by mechanical agitation, and may be spherical, with a ball diameter variation of about 0.0068″ or less. The density of the projectile may be about 10 to 15.5 g/cm 3 , and may have a diameter suitable for use as a shot in a shotgun shell.
In another embodiment, an ammunition projectile comprises powder components comprising tungsten and at least one of copper, iron and nickel, and a binder. The powder components are bound by the binder, grown in layers and sintered to form a sphere. In one embodiment, the sphere has a substantially uniform ball diameter variation, such as about 0.0068″ or less. The powder components may comprise primarily tungsten, and copper, iron and nickel. The sphere may have a density of about 10 to 16 g/cm 3 , more preferably about 10 to 13.5 g/cm 3 . The projectile may be a shot suitable for use in a shotgun shell, and may have a diameter from about 0.05″ to about 0.36″, more preferably from 0.070″ to 0.220″.
In another embodiment, a lot of ammunition projectiles is provided. The lot comprises a plurality of spherical shots, each shot comprising a first component comprising tungsten, and a second component comprising at least one of copper, iron and nickel. The first and second components are bound together with a binder and sintered to form the shots. The shots comprise uniformly grown layers, and the plurality of spherical shots have a lot diameter variation of about 0.01″ or less. In other embodiments, the lot diameter variation may be about 0.008″ or less, about 0.006″ or less, or even about 0.005″ or less. Each spherical shot may have a density of about 10 to 16 g/cm 3 , more preferably about 10 to 13.5 g/cm 3 . Each spherical shot may have the same diameter in the range of 0.070″ to 0.220″.
In another embodiment, an ammunition projectile having a desired aggregate density is provided. The projectile comprises a plurality of layers of different compositions, the plurality of layers including a relatively soft surface layer and a relatively hard section within the surface layer. The desired aggregate density is in the range of about 9 to 16 g/cm 3 . The projectile may be spherical, and the plurality of layers may be concentrically arranged. The relatively hard section within the surface layer may be a core, or may be an intermediate layer, further comprising a relatively soft core. The surface layer may have a density of between about 8 and 10 g/cm 3 , and the core may have a density of between about 8 and 10 g/cm 3 . The relatively hard section may have a density of between about 11 and 18 g/cm 3 . The desired aggregate density may be in the range of about 9.4 and 15 g/cm 3 . In one embodiment, the relatively hard section has a hardness of between about HV 200 and HV 270 and the surface layer has a hardness of about HV 200 or lower. In one embodiment, the core and surface layer have a hardness of about HV 200 or lower and the intermediate layer has a hardness between about HV 200 and HV 270 . The projectile may be substantially lead free, and the surface layer may comprise primarily iron and the relatively hard section may comprise primarily tungsten. The projectile may be spherical and form a shot suitably sized for use in a shotgun shell.
In another embodiment, a method of making an ammunition projectile having a predetermined aggregate density is provided. One or more constituents is selected in powdered form having a density substantially higher than the predetermined aggregate density. One or more constituents is selected in powdered form having a density substantially lower than the predetermined aggregate density. In combination, the constituents having densities substantially higher and substantially lower than the predetermined aggregate density provide an aggregate density substantially equal to the predetermined aggregate density. The powdered constituents are agitated with a binding agent to cause the powdered constituents to form pellets. The pellets are sintered to form projectiles having substantially the predetermined aggregate density.
The powdered constituents having a density substantially higher than the predetermined aggregate density may be selected from the group consisting of virgin tungsten, ferrotungsten, tungsten carbide, tungsten alloys and scrap tungsten. The powdered constituents having a density substantially lower than the predetermined aggregate density may be selected from the group consisting of Fe, Ni, Cu and combinations thereof. The powdered constituents may be agitated using an agitator selected from the group consisting of a drum, disk, dish and pan. Agitating the powdered constituents with a binding agent causes the pellets to agglomerate in generally uniform layers. The predetermined aggregate density may be about 10 to 15.5 g/cm 3 , and the sintered projectiles may have a diameter in the range of 0.070″ to 0.220″. Sintering the pellets may cause the pellets to shrink about 10% to 25%. The pellets may form projectiles suitable for use as shots in a shotgun shell. In one embodiment, distinct mixes of powdered components may be agitated in stages to form pellets having layers of different compositions.
In another embodiment, a method of making spherical shots comprises providing powders comprising tungsten and at least one of copper, iron and nickel. The powders are added to a mechanical agitator while directing liquid binder into the mechanical agitator. The agitator is rotated while continuing to add the powders, whereby powders wetted by the liquid binder agglomerate to form densified balled materials. The method may further comprise screening the densified balled materials to eliminate materials outside of a desired diameter range. The powders may form densified balled materials having a diameter in the range of about 0.05″ to 0.36″. The powders may comprise copper, iron and nickel. The powders may form densified balled materials having a density of about 10 to 16 g/cm 3 , more preferably of about 10 to 13.5 g/cm 3 . The method may further comprise sintering the densified balled materials, such as in a first lower temperature stage and at a second higher temperature stage. The mechanical agitator may comprise a rotating drum. The powders may form densified balled materials at a rate of about 0.1 to 1 mm/hour.
In another embodiment, a method of making ammunition projectiles is provided. A first mix of powdered components is provided, and the first mix is agglomerated with a binding agent to form a pellet core having a first composition. A second mix of powdered components is provided, and the second mix is agglomerated with a binding agent to form a layer surrounding said pellet core having a second composition. The pellet core and the layer are sintered to produce the projectiles.
In one embodiment, the layer surrounding the pellet core may be an intermediate layer, and the method may further comprise providing a third mix of powdered components, and agitating the third mix of powdered components with a binding agent to form a surface layer surrounding the intermediate layer having a third composition. The first composition and third composition may be substantially the same. After sintering, the surface layer and the core may be relatively softer than the intermediate layer. After sintering, the surface layer and the core may have a density between about 8 and 10 g/cm 3 and the intermediate layer may have a density between about 11 and 18 g/cm 3 . In another embodiment, the layer surrounding the pellet core is a surface layer. After sintering the surface layer may have a density between about 8 and 10 g/cm 3 and the core may have a density between about 11 and 18 g/cm 3 . The first mix and the second mix may comprise tungsten and at least one of iron, copper and nickel. The sintered projectiles may form shots suitable for use in a shotgun shell. The pellet core and the layer surrounding the pellet core may have different hardnesses.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a flow chart for forming a shot in accordance with one embodiment of the present invention;
FIG. 2 is a schematic view of a mechanical agitator for forming a shot in accordance with one embodiment of the present invention;
FIG. 3 is a top view of the agitator of FIG. 2 ;
FIG. 4 is schematic view of one preferred form of a tumbling or agitation process used in conjunction with that of FIG. 3 in forming shots;
FIG. 5 is a schematic view of a liquid bridge between two moisturized sphere particles for forming a shot in accordance with one embodiment of the present invention;
FIG. 6A is a scanning electron micrograph at 1000× magnification of a section of a shot formed according to a first embodiment of the present invention;
FIG. 6B is an x-ray map of the section of shot of FIG. 6A , illustrating tungsten content;
FIG. 6C is an x-ray map of the section of shot of FIG. 6A , illustrating iron content;
FIG. 6D is an x-ray map of the section of shot of FIG. 6A , illustrating copper content;
FIG. 6E is another scanning electron micrograph at 1000× magnification of a section of a shot formed according to the first embodiment of the present invention;
FIG. 6F is a scanning electron micrograph at 300× magnification of the shot of FIG. 6E ;
FIG. 7 is a schematic cross section of a shot in accordance with another embodiment of the invention;
FIG. 8A is a scanning electron micrograph at 1000× magnification of a core section of a two-layer shot formed according to one embodiment of the present invention;
FIG. 8B is an x-ray map of the section of shot of FIG. 8A , illustrating tungsten content;
FIG. 8C is an x-ray map of the section of shot of FIG. 8A , illustrating iron content;
FIG. 8D is an x-ray map of the section of shot of FIG. 8A , illustrating copper content;
FIG. 8E is another scanning electron micrograph at 1000× magnification of a core section of a two-layer shot formed according to one embodiment of the present invention;
FIG. 8F is a scanning electron micrograph at 300× magnification of the core section of the two-layer shot of FIG. 8E ;
FIG. 9A is a scanning electron micrograph at 1000× magnification of an intermediate layer of a three-layer shot formed according to one embodiment of the present invention;
FIG. 9B is an x-ray map of the intermediate layer of shot of FIG. 9A , illustrating tungsten content;
FIG. 9C is an x-ray map of the intermediate layer of shot of FIG. 9A , illustrating iron content;
FIG. 9D is an x-ray map of the intermediate layer of shot of FIG. 9A , illustrating copper content;
FIG. 9E is another scanning electron micrograph at 1000× magnification of an intermediate layer of a three-layer shot formed according to one embodiment of the present invention;
FIG. 9F is a scanning electron micrograph at 300× magnification of the intermediate layer of the three-layer shot of FIG. 9E ;
FIG. 9G is a scanning electron micrograph at 1000× magnification of the intermediate layer of the three-layer shot of FIG. 9E , near the intersection with a surface layer;
FIG. 9H is a scanning electron micrograph at 300× magnification at about the intersection of the intermediate layer and the surface layer of the three-layer shot of FIG. 9G ;
FIGS. 9I and 9J are scanning electron micrographs at 1000× magnification of the surface layer of the three-layer shot of FIG. 9E ;
FIGS. 10A-10E show scanning electron micrographs at 100× magnification of a compacted tungsten-iron sample;
FIG. 10F is a scanning electron micrograph at 300× magnification of the compacted tungsten-iron sample of FIGS. 10A-10E ;
FIG. 10G is a scanning electron micrograph at 1000× magnification of the compacted tungsten-iron sample of FIGS. 10A-10E ;
FIG. 10H is an x-ray map of the sample of FIG. 10G , illustrating iron content;
FIG. 10I is an x-ray map of the sample of FIG. 10G , illustrating tungsten content;
FIGS. 11A-11E show scanning electron micrographs at 100× magnification of a compacted tungsten-copper sample;
FIG. 11F is a scanning electron micrograph at 300× magnification of the compacted tungsten-copper sample of FIGS. 11A-11G ;
FIG. 11G is a scanning electron micrograph at 1000× magnification of the compacted tungsten-copper sample of FIG. 11A-11E ;
FIG. 11H is an x-ray map of the sample of FIG. 11G , illustrating copper content;
FIG. 11I is an x-ray map of the sample of FIG. 11G , illustrating tungsten content;
FIGS. 12A-12E show scanning electron micrographs at 100× magnification of a compacted tungsten-iron-nickel-copper sample;
FIG. 12F is a scanning electron micrograph at 300× magnification of the compacted tungsten-iron-nickel-copper sample of FIGS. 12A-12E ;
FIG. 12G is a scanning electron micrograph at 1000× magnification of the compacted tungsten-iron-nickel-copper sample of FIGS. 12A-12E ;
FIG. 12H is an x-ray map of the sample of FIG. 12G , illustrating iron content;
FIG. 12I is an x-ray map of the sample of FIG. 12G , illustrating tungsten content;
FIG. 12J is an x-ray map of the sample of FIG. 12G , illustrating nickel content;
FIG. 12K is an x-ray map of the sample of FIG. 12G , illustrating copper content;
FIGS. 13A-13E show scanning electron micrographs at 100× magnification of another compacted tungsten-iron-nickel-copper sample;
FIG. 13F is a scanning electron micrograph at 300× magnification of the compacted tungsten-iron-nickel-copper sample of FIGS. 13A-13E ;
FIG. 13G is a scanning electron micrograph at 1000× magnification of the compacted tungsten-iron-nickel-copper sample of FIGS. 13A-13E ;
FIG. 13H is an x-ray map of the sample of FIG. 13G , illustrating iron content;
FIG. 13I is an x-ray map of the sample of FIG. 13G , illustrating tungsten content;
FIG. 13J is an x-ray map of the sample of FIG. 13G , illustrating nickel content;
FIG. 13K is an x-ray map of the sample of FIG. 13G , illustrating copper content.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In aerodynamics, parasitic drag is the force caused by moving a solid object through a fluid such as air. Parasitic drag is made up of many components, the most prominent being form drag. The general size and shape of the body is the most important factor in form drag; bodies with a larger apparent cross-section will have a higher drag than thinner bodies. “Clean” designs, or designs that are streamlined and smoothed also contribute to achieving minimum form drag. Form drag follows the drag equation:
D= ½( Cd )(ρ) A ( V 2 )
Where
D=drag force
Cd=drag coefficient
ρ=density of fluid
A=reference area
V=velocity of the projectile relative to the fluid
Inarguably, smoother objects can have much lower values of Cd; everything being equal, a precise sphere with a smoother surface will give minimal drag force. More importantly, a group of such high quality spheres will travel in a cohesive way toward a target thus give the best density pattern and maximum delivered energy.
Water fowl loads are regarded as high performance use for which the market often demands high quality shots. The manufacturing process disclosed herein provides high quality nontoxic high density shots that not only have predictable ballistic characteristics during launch, but also have superior loading characteristics for smooth charge during fabrication. This benefits both the manufacturer and general public reloader alike.
In a first embodiment of the invention, a high density, nontoxic shot is provided that is generally consistent in material construction and composition throughout the cross section of the shot. The nontoxic shot is substantially lead-free. As used herein, the term “shot” refers to an ammunition projectile that may be in the form of a pellet, sphere, ball or other small projectile used, for example, to form a charge of a shotgun. Although the preferred embodiments are described with respect to shots, it will be appreciated that embodiments of this invention may be applicable to any suitable type of ammunition projectile, such as bullets and buck shots.
The shot according to this first embodiment preferably comprises tungsten as a first component and preferably copper and/or iron as a second component. In one embodiment, the shot comprises tungsten as the primary component, and may also comprise secondary components comprising copper and/or iron. The term “primary” or “primarily” as used herein indicates that there is more of this component than any other component, although it will be appreciated that in some embodiments, there may be less tungsten than another component. Tungsten may be provided in the form of virgin tungsten, ferrotungsten, tungsten carbide, tungsten alloys and even scrap tungsten. In one embodiment, nickel may also be used as a secondary component. In other embodiments, polymers may also be used as secondary components. Alternatively, compositions may be used with a relatively high amount of copper (e.g., about 19% or more), and substantially no nickel, as nickel can be harmful to small creatures that may be food to fish. Tables 1 and 2 illustrate preferred compositions for a tungsten shot without nickel having different aggregate densities. Percentages as provided herein are in weight percent.
TABLE 1
Density (g/cm 3 )
W wt %
Cu wt %
Fe wt %
13.50
70
19
11
13.00
66
19
15
12.50
62
21
17
12.00
59
21
20
11.50
53
24
23
11.00
49
24
27
10.50
43
26
31
10.00
38
26
36
TABLE 2
Density (g/cm 3 )
W wt %
Fe wt %
13.50
73.40
26.60
13.00
70.00
30.00
12.50
66.00
34.00
12.00
62.00
38.00
11.50
58.00
42.00
11.00
53.20
46.80
10.50
47.60
52.40
10.00
41.40
58.60
Tables 3A, 3B and 3C illustrate alternative compositions for a tungsten shot also containing nickel. These compositions have a relatively low amount of nickel (e.g., about 7% or less), and less copper than in the embodiments above, to minimize any harmful effects of the nickel content.
TABLE 3A
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
70
7
11
12
13.00
66
7
11
16
12.50
62
7
13
18
12.00
59
7
13
21
11.50
53
7
15
25
11.00
49
7
15
29
10.50
43
7
16
34
10.00
38
7
16
39
TABLE 3B
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
69
7
13
11
13.00
64
7
13
16
12.50
59
7
13
21
12.00
59
7
13
21
11.50
57
7
13
23
11.00
54
7
11
28
10.50
51
7
11
31
10.00
48
7
11
34
TABLE 3C
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
69
6
13
12
13.00
65
6
13
16
12.50
61
6
14
19
12.00
56
7
15
22
11.50
52
7
15
26
11.00
47
7
15
31
10.50
41
7
16
36
10.00
35
7
17
41
In certain preferred embodiments, tungsten can be provided in the range of about 30 wt % to about 80 wt %, more preferably about 35 wt % to about 75 wt %, and may be provided in amounts greater than about 40 wt %, about 45% wt %, about 50 wt %, about 55 wt %, about 60 wt %, about 65 wt %, or about 70 wt %, depending on the desired final density of the shot. Copper may be provided in ranges from about 10 wt % to about 30 wt %, more preferably about 10 to 20 wt %, and even more preferably about 11 to 17 wt %, such as when provided in a composition with tungsten, nickel and iron. Nickel may be provided in an amount of about 7 wt % or less. Iron may be provided in an amount of about 10 to 60 wt %, more preferably about 10 to 40 wt %, with higher amounts of iron generally correlating to smaller amounts of tungsten. It will be appreciated that specific combinations of compositions may be selected to optimize not only the density of the material, but also to optimize the hardness of the shot as well as the ability of the materials to agglomerate and form a uniform, layered structure, described further below.
Although the shot examples provided above illustrate a density of between about 10 and 13.5 g/cm 3 , it will be appreciated that shots in accordance with the preferred embodiments can be made of any desired density, for example, between about 10 and 16 g/cm 3 , more preferably between about 10 and 15.5 g/cm 3 , even more preferably between about 10 and 15 g/cm 3 . In one preferred embodiment, the shot may have a density of less than 13.5 g/cm 3 , even more preferably about 11 to 12 g/cm 3 .
Referring in more detail to the drawings, FIG. 1 illustrates one embodiment of the sequence of steps followed in the manufacture of nontoxic high density shots wherein the density can be closely controlled according to the desired ballistics and other characteristics of the projectiles. In step 110 , an appropriate mix of raw materials is obtained with the desired composition, such as described above. In the preferred embodiments, raw materials are in the form of powdered constituents obtained from known sources, and may comprise tungsten powder and iron, copper and/or nickel powder. The powders may be mixed in a suitable ball mill as is known to one of skill in the art.
The mixed powders are then filled into an appropriate processing apparatus (step 120 ). One preferred form of the apparatus is illustrated in FIGS. 2 through 4 , which illustrates the use of a mechanical agitation or tumbling process to agglomerate the powders in a rotating drum. In one embodiment, an agitator 22 that is used is an inclined drum shaped mechanical agitator or agglomerator. Other suitable apparatuses may include other drum or disk, dish or pan agglomerators. Further details of suitable agglomerators and associated processes are described in Wolfgang Pietsch, Agglomeration Processes: Phenomena, Technologies, Equipment (Wiley-VCH Verlag GmbH, Weinheim, 2002), the entirety of which is hereby incorporated by reference.
The agitator 22 can be equipped with air atomized spray nozzles 24 directing binder flow 44 (step 130 ) to a powder section 46 on the rotating drum 26 . As binder flows into the drum, FIG. 4 shows the wetted powders 42 on rotation agglomerate and begin to form densified balled material or spheres. These small spheres tend to segregate toward the edge of the drum 26 , changing their flow pattern 32 in the drum as shown in FIG. 3 . Constant monitoring of the process is preferred, with control on the particle size growth and distribution determined by a spraying rate, incoming feed rate, drum rpm and angle of inclination. Preferably, a very low spraying rate is used such that the spheres form and grow very slowly, allowing the sphere layers to grow uniformly. This slow growth also ensures a denser product having fewer or virtually no air pockets.
In one embodiment, the agitator 22 has a size of 22 inches in diameter, and can be operated under the following parameters.
TABLE 4
Spraying Rate
Varying
Incoming Feed Rate
Varying
Drum RPM
15 to 40
Angle of Inclination
45 degrees
The agitator preferably uses a liquid binder, more preferably only water. In other embodiments, the binder may be an organic or inorganic binders. Examples of suitable organic binders include, but are not limited to CMC (carbo-methyl-cellulose), alcohols, paraffin, polyvinyl alcohol (PVA), starches, and gums. Examples of inorganic binders include, but are not limited to, alkali silicates, alum, gypsum, lime, and water.
The spheres preferably grow in layers due to particle adhesion, whereby forces between spheres are caused by liquid bridges. Capillary pressure and tensile strength of moist particles are associated with each other, and are influenced to a great extent by the amount of liquid that is present in the pore volume of the agglomerate. With increasing liquid saturation, more and more pores are filled and the liquid bridge and the saturated pores models coexist. The adhesion force of a liquid bridge is proportional to the surface tension α, the particle diameter x, and a function of the liquid bridge angle β, the angle of contact δ, and the dimensionless quotient a/x, which represents distance at the coordination point. As shown in FIG. 5 the effective adhesion force of a liquid bridge is defined as:
A iL =αxf (β,δ, a/x )
Further details are described in Wolfgang Pietsch, Agglomeration Processes: Phenomena, Technologies, Equipment (Wiley-VCH Verlag GmbH, Weinheim, 2002), page 58, incorporated by reference above.
If desired, the spraying of the binder into the drum may optionally be turned on and off as needed to ensure uniform agglomeration. Optionally, choppers may also be used to avoid unwanted agglomeration or the formation of oversized conglomerates. For example, a high speed chopper, knife head, accelerator, intensifier, turbine, mill or other suitable tool (all referred to herein generically as a “chopper”) is used to destroy undesired agglomerates which hamper mixing. Choppers can be applied at any suitable point in the process, and may operate at high speeds, e.g., in excess of 500 rpm, 1000 rpm or 1800 rpm. Choppers also assist in distributing binder liquid more uniformly.
After the spheres have grown to an appropriate desired size, precise control over the size of the spheres may be maintained by using a screening process in step 140 . In one embodiment, screens may be used through which the spheres may be passed. A first screen may be used which has a minimum pore diameter, such that any spheres that pass through the screen will be rejected. These rejected spheres can be recycled into the agitator until further growth makes them of a potentially viable size. A second screen may be used which has a maximum pore diameter, such that only spheres that pass through the screen may be accepted for sintering. Spheres that exceed the pore size of the screen can be crushed and then recycled as powder in the agitator.
With the spheres that have passed the screening process, a visual inspection may be used to ensure whether the shots meet desired specifications (step 150 ). In one method, a lot of 100 g of shots is taken, and the number of pieces of shots is counted. If the number falls within a desired range, this reflects that the desired average density of the shots has been achieved. In another method, shot diameters can be measured using a micrometer or Vernier calipers along multiple axes of a shot to determine whether the shot has substantially uniform sphericity, as described below. Shots that do not meet specifications can be recycled such as by crushing back into the process.
Spheres that have passed the screening process and a visual inspection, if performed, may proceed to step 160 . At step 160 , a determination is made whether a multi-layer shot of differing compositions between distinct layers is to be formed. The formation of multi-layer shots is described in further detail below. For shots formed according to the first embodiment, the process continues to step 170 .
The spheres are then sintered, for example in a first stage at about 650° C. for about 1.8 to 2 hours, and then at a second stage at about 1380° C. for about 1.8 to 2 hours for a Ni containing mix with Cu, and about 1450° C. for a mix without nickel. Other suitable sintering conditions may also be used. From the unsintered, green shot to the sintered shot, the spheres preferably shrink between about 10% to 25%, more preferably about 15% to 20% in diameter. Table 5 illustrates examples of shrink ratios to form shots of certain size ranges:
TABLE 5
Size Range
Shrink Ratio (Green Shot: Sintered Shot)
0.100″ to 0.120″
1.16:1.00
0.130″ to 0.140″
1.17:1.00
0.150″ to 0.180″
1.18:1.00
0.190″ to 0.220″
1.20:1.00
The agitation process desirably provides precise control of a final, sintered product by operating the agitator in a continuous, prolonged and controlled manner. Moreover, tight control over the ratio of particles in the sintering mix further contributes to precise control in the final sintered product. No grinding or polishing is needed to achieve tolerance prescribed.
The precision and control over the processing of the shot allows for bulk quantity production in a very wide range of sizes, for example, from 0.070″ to 0.220″ in diameter, selected and processed to have very high tolerance. Shots can be made into any desired diameter suitable for use in a shotgun shell, for example, between about 0.05″ to about 0.36″, and more particularly 0.100″, 0.110″, 0.120″, 0.130″, 0.150″, and 0.180″. Tolerance may be measured by the ball diameter variation of a sphere, e.g., by comparing the largest diameter of a sphere to the smallest diameter of the same sphere, and can be ensured using the screening process described above. A lot diameter variation can also be measured, comparing the largest diameter of any sphere to the smallest diameter of any sphere. In one embodiment, the lot diameter variation is preferably about 0.01″ or less, more preferably about 0.008″ (about 0.20 mm) or less, more preferably about 0.006″ (about 0.15 mm) or less, even more preferably about 0.005″ or less. The ball diameter variation is usually about ½ or larger of the lot diameter variation, more preferably about 50 to 85% of the lot diameter variation (i.e., about 0.004″ to 0.0068″ or less, more preferably about 0.003″ to 0.0051″ or less, even more preferably about 0.0025″ to 0.00425″ or less). Thus, no pressing, compacting or casting is required, making for exceptional efficiency in making smaller shots that are very uniform in size.
Shots formed according to the first embodiment preferably have a desired hardness, for example about Vickers hardness HV 230 or less. Vickers hardness may be measured using a suitable Vickers hardness machine, for example using forces of 1, 2, 5, 10, 30, 50 and 100 kgf. In one particular embodiment, shots formed according to the method described above and tested using 30 kgf provides a Vickers hardness of between about HV 105 and HV 132 . An alternative measurement of hardness may use a Rockwell hardness test.
In one embodiment, the shot preferably has a hardness of about 86 HR15T or less.
FIG. 6A is a scanning electron micrograph at 1000× magnification of a shot formed according to the first embodiment described above. This shot has a density of about 11 g/cm 3 , with a composition of about 48 wt % W, about 7 wt % Ni, about 15 wt % Cu and about 30 wt % Fe. FIG. 6E shows another scanning electron micrograph at 1000× magnification of this shot, and FIG. 6F shows a scanning electron micrograph of the shot at 300× magnification. As can be seen, the shot has generally circular tungsten-rich grains of substantially the same size (e.g., about 10 microns or less in diameter) that are generally uniformly distributed. This uniform distribution is further illustrated in FIGS. 6B-6D , which illustrate x-ray maps of the shot for tungsten, iron and copper, respectively. In each of these x-ray maps, the lighter portions represent tungsten, iron or copper content, respectively. It can be seen from these maps that the distribution of these components is generally uniform throughout the shot, which can be attributed to the layered growth accomplished using the agglomeration process described above.
In a second embodiment of the invention, in the flow chart of FIG. 1 , at step 160 , a layered process is used. In such an embodiment, after spheres of a first desired diameter are formed, the process returns to step 110 , where a second composition of powders is mixed. It will be appreciated that the second composition of powders may have been pre-prepared. This second composition of powders is preferably selected to produce either a relatively harder or softer layer of material, preferably with a higher or lower density, as desired by the final shot. Preferably, at step 120 , the apparatus 22 is filled and mixed with a different composition of raw materials to provide a layer having a different composition surrounding the first layer or core formed above. Agglomeration occurs as above to a desired size, and the resulting spheres can be screened and inspected as above. If additional layers are desired (e.g., three or more layers), the process at 160 returns again to steps 110 and 120 for mixing and filling additional powder compositions into the apparatus for formation of the multiple layers over preceding layers. Once the shots are formed having the desired number of layers, with the desired composition of each layer, the desired sphericity and the desired aggregate density, the shots can be sintered as described above.
In one embodiment, a high density nontoxic shot is provided that has a generally soft core, a rugged intermediate layer, and a soft surface layer. Each of the layers is preferably spherical in shape and have the same center. The specific weight of each layer is preferably different from the next layer, selected to allow a wide range of aggregate density, no matter the production method used. In another embodiment, a two layer shot may be formed having a rugged core, and a soft surface layer. Shots with other numbers of distinct layers may also be provided.
FIG. 7 illustrates a cross section of one embodiment of a three layer shot. The shot 60 includes a core 62 , an intermediate layer 64 , and a surface layer 66 . Each of the core 62 , the intermediate layer 64 and the surface layer 66 preferably have a spherical outer surface, and preferably have the same center. The core 62 and surface layer 66 are preferably softer and less dense relative to the intermediate layer, which is relatively harder and denser.
The composition of each of the layers may be selected to produce the desired density and hardness. Each of the layers having different composition may preferably be formed from substantially lead-free compositions comprising tungsten as a first component, and iron, copper and/or nickel as additional component(s). For example, compositions taken from Tables 1-3C and used for shots made according the first embodiment above may be used for the intermediate layer. For the core and surface layers, less or no tungsten may be used. For example, in one embodiment, about 10% W or less may be used, with greater than about 60% Fe, and between about 4 and 15% Ni and about 10% and 20% Cu. In one preferred embodiment, the surface layer may have about 10% W, about 63% Fe, and about 27% Cu and Ni (e.g., about 16% Cu and about 11% Ni), forming a layer with a density of about 9.3 g/cm 3 .
Table 6 illustrates one example of the aggregate density of a three-layered sphere.
TABLE 6
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
71
5
9
15
13.00
68
5
9
18
12.50
63
6
12
19
12.00
59
6
14
21
11.50
54
7
14
25
11.00
49.3
7
15
28.7
10.50
43
7
16
34
10.00
40
7
16
37
In other embodiments, the aggregate density of the three-layer shot may correspond to the values provided in Tables 1, 2, 3A, 3B or 3C above.
Tables 7A and 7B illustrate compositions that may be used for the soft inner core and soft surface layer of a three layer shot. For example, the composition in Table 7A may be used for the core and surface layer of a relatively smaller shot e.g., of 0.120″ in diameter, and the composition in Table 7B may be used for the core and surface layer of a relatively larger shot, e.g., of 0.22″ in diameter.
TABLE 7A
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
10
10.4
16.6
63
13.00
10
10.1
16.9
63
12.50
10
9.5
17.5
63
12.00
10
9.0
18
63
11.50
10
10.0
17
63
11.00
10
9.5
17.5
63
10.50
10
9.0
18
63
10.00
10
8.2
18.8
63
TABLE 7B
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
10
10.1
16.9
63
13.00
10
9.5
17.5
63
12.50
10
9
18
63
12.00
10
9.9
17.1
63
11.50
10
9.5
17.5
63
11.00
10
9
18
63
10.50
10
8.6
18.4
63
10.00
10
8.2
18.8
63
Tables 8A and 8B illustrate compositions that may be used for the harder intermediate layer of a three layer shot. For example, the composition in Table 8A may be used for a relatively smaller shot e.g., of 0.120″ in diameter, and the composition in Table 9B may be used for a relatively larger shot, e.g., of 0.22″ in diameter.
TABLE 8A
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
87
5
8
0
13.00
82
6
10
2
12.50
77
6
11
6
12.00
73
6
12
9
11.50
67
7
12
14
11.00
61
7
13
19
10.50
56
7
14
23
10.00
46
7
16
31
TABLE 8B
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
81
6
10
3
13.00
77
6
11
6
12.50
72
6
12
10
12.00
67
7
12
14
11.50
62
7
13
18
11.00
56
7
14
23
10.50
49
7
15
29
10.00
42
7
16
35
It will be appreciated that the diameter of the core 62 , the thickness of the intermediate layer 64 , and the thickness of the surface layer 66 may be adjusted to provide the desired balance of density and hardness for the aggregate shot 60 . In certain embodiments, the diameter of the core 62 may range from about 1.4 mm to about 2.4 mm, the thickness of the intermediate layer may range from about 0.5 mm to about 1.6 mm, and the thickness of the surface layer may be about 0.2 mm or less. In one embodiment, the surface layer 66 may be about 0.1 mm thick for shots having a diameter from 0.070″ to 0.100″, about 0.15 mm for shots having a diameter from 0.100″ to 0.180″, and about 0.20 mm for shots having a diameter of 0.180″ or greater. For example, for a 0.130″ diameter shot, the core may have a diameter of about 1.6 mm, the intermediate layer may have a thickness of about 0.65 mm, and the surface layer may have a thickness of about 0.2 mm. Generally, taking 0.130″ as an example, the core radius may be about 40 to 60%, more preferably about 50% of the radius of the aggregate shot, the intermediate layer thickness may be about 30 to 50%, more preferably about 40% of the radius of the aggregate shot, and the surface layer thickness may be about 5 to 15%, more preferably about 12% of the radius of the aggregate shot. As with the first embodiment, shots having a diameter in the range of 0.070″ to 0.220″ in diameter, or any diameter suitable for use in a shotgun shell, may be made.
As in the first embodiment described above, a mechanical agitation or tumbling process can be used to achieve high tolerance control over the chemistry and ratio in the powder mix. Continuous, prolonged, and controlled agitation using a drum agitator, for example, also allows the ability to prescribe a transitioned composition so to achieve transition of hardness at different layer of the shot, from core to surface. Multiple powder mixes are provided with selected compositions to add to the agitator in stages to form each desired layer. In one embodiment, drums can be changed in the agitator from the core mix to the intermediate mix, and then drum can be changed back to the core mix to form the surface layer. Thus, in this example, the core and the surface layer have the same composition. Preferably, after each of the core 62 , intermediate layer 64 , and surface layer 66 are formed, screening such as described above takes place to assure uniformity and sphericity of product. Recycling of metal powder is built into the production process so there is no waste and very little scrap material. The shot can be sintered such as described above.
As with the first embodiment described above, a slow growth process is used to ensure sphericity of the formed spheres. In one embodiment, the core is grown in the agitator over about 2 to 3 hours, the intermediate layer is grown in the agitator for about 3 to 5 hours, and the surface layer is grown in the agitator over about 1 hour. Overall, the growth rate of the spheres may be in the range of about 0.1 to 1 mm/hour, more preferably about 0.1 to 0.5 mm/hour, and even more preferably about 0.1 to 0.3 mm/hour.
In one embodiment, the core 62 has a density of between about 8 and 10 g/cm 3 , the intermediate layer 64 has a density of between about 11 and 18 g/cm 3 , more preferably between about 11 and 13.5 g/cm 3 , and the surface layer 66 has a density of between about 8 and 10 g/cm 3 . The aggregate density of the shot 60 can be adjusted, depending on the thickness of each layer, to produce densities in the range of about 9 to 16 g/cm 3 , more preferably between about 9.4 to 15 g/cm 3 , even more preferably between about 10 and 13 g/cm 3 , and even more preferably between about 11 and 12 g/cm 3 .
It will be appreciated that for a two layer shot, the rugged core may have a density between about 11 and 18 g/cm 3 , and the surface layer may have a density between about 8 and 10 g/cm 3 . The core of the two layer shot may have compositions such as provided above for the intermediate layer of the three layer shot, and the surface layer of the two layer shot may have compositions such as provided above for the surface layer of the three layer shot. In one embodiment, the core of a two layer shot may have the compositions provided in Table 9A and 9B below. For example, the compositions in Table 9A may be used for the core of a smaller shot, e.g., a 0.07″ diameter shot, and the compositions in Table 9B may be used for the core of a larger shot, e.g., a 0.22″ diameter shot. The compositions in Tables 10A and 10B may be used for the surface layer of the two layer shot; for example, the compositions in Table 10A may be used for a smaller shot, e.g., a 0.07″ diameter shot, and the compositions in Table 10B may be used for a larger shot, e.g., a 0.22″ diameter shot. The core and surface layer of a two-layer shot may have thicknesses such as described above. The aggregate density of the two layer shot may correspond to the values provided in Tables 1, 2, 3A, 3B or 3C above.
TABLE 9A
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
82
6
10
2
13.00
78
6
10
6
12.50
74
6
10
10
12.00
70
6
12
12
11.50
64
6
12
18
11.00
59
7
14
20
10.50
50
7
15
28
10.00
46
7
15
32
TABLE 9B
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
77
6
11
6
13.00
73
6
12
9
12.50
69
6
12
13
12.00
64
6
12
18
11.50
59
7
14
20
11.00
53
7
14
26
10.50
47
7
15
31
10.00
40
7
17
36
TABLE 10A
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
10
10
17
63
13.00
10
10
17
63
12.50
10
10
17
63
12.00
10
9
18
63
11.50
10
9
18
63
11.00
10
9
18
63
10.50
10
8.6
18.4
63
10.00
10
8.6
18.4
63
TABLE 10B
Density (g/cm 3 )
W wt %
Ni wt %
Cu wt %
Fe wt %
13.50
10
9.5
17.5
63
13.00
10
9
18
63
12.50
10
9
18
63
12.00
10
9
18
63
11.50
10
9
18
63
11.00
10
9
18
63
10.50
10
8.6
18.4
63
10.00
10
7.9
19.1
63
In the three layer shot, the core 62 and surface 66 may have a hardness of about HV 200 or lower, more preferably about HV 110 or lower, even more preferably about HV 100 or lower. In one embodiment, the surface hardness is between about HV 105 and HV 151 , and the core hardness is between about HV 105 and HV 120 . The hardness of the intermediate layer 64 may be between about HV 200 and HV 270 , more preferably between about HV 200 and HV 220 . In a two layer shot, in one embodiment, the surface layer hardness may preferably be about HV 105 or less, and the core hardness may preferably be between about HV 105 and HV 196 .
An alternative measurement of hardness may use a Rockwell hardness test. In one embodiment, the surface layer of a two layer or three layer shot is preferably about 80 HR15T or less, more preferably about 69 HR15T or lower. The relatively hard layer (e.g., the core of a two layer shot or the intermediate layer of a three-layer shot) will have a higher hardness value, but preferably will not be too high, and in one embodiment, will have a value of about 86 HR15T or less.
After the shot is formed into a sphere and sintered, tin, copper or zinc can be plated or hot dipped onto the outer surface of the shot. This layer helps to make the shot softer and protect it from oxidation.
Advantageously, the soft core and soft surface layer of the shot of FIG. 7 makes the shot not prong to ricochet and easier on the gun barrel. The harder, denser intermediate layer keeps the shot rugged and in its spherical form in set back (firing), and in flight, until it hits the target. Upon impact with the target, because of the soft core, and somewhat because of the soft shell, this product will deform, thereby transferring the momentum (energy) onto the target.
The softness or hardness of the layers or compositions as measured herein are indicative of the ability of the shot to deform upon impact. Other suitable measurements made also be used, such as by measuring the relative ductility of the material or layer, such that a more ductile material will plastically deform substantially before fracture. The multiple layer shots as described above are manufactured to provide desired deformation of the shot upon impact with a target. For example, in a two layer or three layer shot, the softer outer layer has relatively higher ductility than the core or intermediate layer, allowing the material to deform and spread outwardly upon impact. This enables a greater transfer of energy to the intended target, with increased surface area upon contact. With the three layer shot in particular, where the inner core and the surface layer are both made of a relatively softer, more ductile material, the shot upon impact will desirably flatten to impart greater energy to the target.
It will be appreciated that the methods described above can be modified to form shots of various compositions. For example, a shot can be made with a relatively soft core and a relatively hard surface. Alternatively, a shot can be made with a relatively hard core, a relatively soft intermediate portion and a relatively hard surface.
Soft and hard powder mixes may be selected having desired compositions to produce layers of desired hardness and/or density. In one embodiment, hard powder mixes comprise a significant amount of tungsten, preferably about 60 wt % or more, about 65 wt % or more, or about 70 wt % or more. These hard powder mixes may have densities greater than about 12 g/cm 3 , more preferably greater than about 13 g/cm 3 , even more preferably greater than about 14 g/cm 3 . Softer powder mixes comprise less tungsten, preferably about 30 wt % or less, more preferably about 20 wt % or less, even more preferably about 10 wt % or less. These softer powder mixes may have densities less than about 10 g/cm 3 , more preferably less than about 9 g/cm 3 , even more preferably less than about 8 g/cm 3 .
FIG. 8A is a scanning electron micrograph at 1000× magnification of a core section of a two-layer shot formed according to the second embodiment of the present invention, having a relatively hard core and a relative soft surface. This shot has an aggregate density of about 11 g/cm 3 , with a core density of about 13.76 g/cm 3 and a surface layer density of about 8.64 g/cm 3 . The core composition comprises about 69 wt % W, about 7 wt % Ni, about 10 wt % Cu and about 14 wt % Fe. The surface layer composition comprises about 10 wt % W, about 7 wt % Ni, about 20 wt % Cu and about 63 wt % Fe. FIGS. 8B-8D are x-ray maps illustrating tungsten, iron and copper content in the core, respectively, such as described above. FIGS. 8E and 8F are additional scanning electron micrographs at 1000× and 300× magnification, respectively, of the core of the two-layer shot. Like the single composition shot of FIG. 6A above, the core of the two-layer shot has generally circular tungsten-rich grains of substantially the same size (about 10 microns or less), and the grains are generally uniformly distributed.
FIG. 9A is a scanning electron micrograph at 1000× magnification of an intermediate layer of a three-layer shot formed according to the second embodiment of the present invention. This shot has an aggregate density of about 11 g/cm 3 , with a intermediate layer density of about 13.76 g/cm 3 and a core and surface layer density of about 8.64 g/cm 3 . The intermediate layer composition comprises about 69 wt % W, about 7 wt % Ni, about 10 wt % Cu and about 14 wt % Fe. The core and surface layer composition comprises about 10 wt % W, about 7 wt % Ni, about 20 wt % Cu and about 63 wt % Fe. FIGS. 9B-9D are x-ray maps illustrating tungsten, iron and copper content, respectively, of the intermediate layer, such as described above. FIGS. 9E and 9F are additional scanning electron micrographs at 1000× and 300× magnification, respectively, of the intermediate layer of the three-layer shot. Like the single density shot of FIG. 6A above, the intermediate layer of the three-layer shot has generally circular tungsten-rich grains of substantially the same size (about 10 microns or less), and the grains are generally uniformly distributed.
FIG. 9G shows a scanning electron micrograph at 1000× magnification of the intermediate layer near the interface with the surface layer. FIG. 9H is a scanning electron micrograph at 300× magnification showing both the intermediate and the surface layers, with the core being shown on the left. FIGS. 9I and 9J are scanning electron micrographs at 1000× magnification showing the surface layer. The core of the three-layer shot would appear similar.
Shots produced according the methods described above compare favorably to shots formed by prior art processes such as by compacting. FIGS. 10A-10E are scanning electron micrographs at 100× (taken at five locations of the sample), FIG. 10F at 300× magnification, and FIG. 10G at 1000× magnification, of a compacted tungsten-iron sample, containing 30 wt. % W and 70 wt. % Fe. The sample was compacted at 100 ksi, and sintered at 900° C., producing a sample with a density of 7.81 g/cm 3 . FIG. 10H is an x-ray map of the sample illustrating iron content, and FIG. 10I is an x-ray map of the sample illustrating tungsten content. Comparing this sample to the non-compacted shots as described above, it will be appreciated that the grains of the shots produced according to preferred embodiments of the invention have smaller grains that are much more uniformly distributed and uniform in grain size.
FIGS. 11A-11E are scanning electron micrographs at 100× (taken at five locations of the sample), FIG. 11F at 300× magnification, and FIG. 11G at 1000× magnification, of a compacted tungsten-iron sample, containing 43 wt. % W and 57 wt. % Cu. The samples were compacted at 100 ksi, and sintered at 900° C., producing a sample with a density of 9.43 g/cm 3 . FIG. 11H is an x-ray map of the sample illustrating copper content, and FIG. 11I is an x-ray map of the sample illustrating tungsten content. As with the sample of FIGS. 10A-10G , comparing this sample to the shots as described above, it will be appreciated that the grains of the shots produced according to preferred embodiments of the invention have smaller grains that are much more uniformly distributed and uniform in grain size.
FIGS. 12A-12E are scanning electron micrographs at 100× (taken at five locations of the sample), FIG. 12F at 300× magnification, and FIG. 12G at 1000× magnification, of a compacted tungsten-iron sample, containing 69 wt. % W, 16 wt. % Fe, 6 wt. % Ni and 9 wt. % Cu. The sample was compacted at 100 ksi, and sintered at 900° C., producing a sample with a density of 10.70 g/cm 3 . FIG. 12H is an x-ray map of the sample illustrating iron content, FIG. 12I is an x-ray map of the sample illustrating tungsten content, FIG. 12J is an x-ray map of the sample illustrating nickel content, and FIG. 12K is an x-ray map of the sample illustrating copper content. These figures demonstrate that the components, particularly the iron, tungsten and copper constituents, are not substantially uniformly distributed, and the grains are not generally circular or uniform in size. Comparing them in particular to the intermediate layer of the shot shown in FIG. 9A , it can be seen that shots formed according to preferred embodiments of the invention have grains that are smaller, generally more circular, more uniform in size and more evenly distributed.
FIGS. 13A-13E are scanning electron micrographs at 100× (taken at five locations of the sample), FIG. 13F at 300× magnification, and FIG. 13G at 1000× magnification, of a compacted tungsten-iron sample, containing 69 wt. % W, 16 wt. % Fe, 6 wt. % Ni and 9 wt. % Cu. The sample was compacted at 100 ksi, and sintered at 1368° C., producing a sample with a density of 13.44 g/cm 3 . FIG. 13H is an x-ray map of the sample illustrating iron content, FIG. 13I is an x-ray map of the sample illustrating tungsten content, FIG. 13J is an x-ray map of the sample illustrating nickel content, and
FIG. 13K is an x-ray map of the sample illustrating copper content. The grains illustrated are still not as evenly distributed as shown as for the intermediate layer of the shot of FIG. 9A .
Comparing FIGS. 9A and 9G with FIG. 13G in particular, it can be seen the shots formed according to one embodiment of the invention are more dispersely distributed and have a smaller grain size. For example, FIGS. 9A and 9G show W-rich grains that have an average grain size of less than about 10 microns. The disperse distribution of the grains can be measured by considering that these grains occupy greater than about 80% of any given cross-sectional area of the shot, more preferably greater than about 90%, and even more preferably greater than about 95%.
The grains are also generally uniform in size. For example, preferred embodiments will have about 80% or more of the grains with a diameter less than a desired diameter grain size, for example, about 10 microns. In another embodiment, about 90% or more, or even about 95% or more, of the grains will have diameters less than the desired diameter grain size. The desired diameter grain size may have different values, for example, about 15 microns, about 20 microns, about 25 microns, 30 microns, etc., depending on the composition. In another embodiment, general uniformity in grain size can be determined based on whether a certain percentage of the grains, for example, about 50% or more, about 60% or more, about 70% or more, about 80% or more, about 90% or more, or about 95% or more of the grains, fall within a certain desired range of grain diameters. This range may be, for example, about 10 microns, about 15 microns, about 20 microns, about 25 microns, about 30 microns, etc. It will be appreciated that the agglomeration process described above allows formation of shots having this desired combination of small, disperse, uniform grain size, which is desirable to form shots that are substantially spherical and have uniform desired properties (e.g., hardness, ductility) to improve performance of the shot.
In another embodiment, tungsten carbide scrap can be processed to form tungsten powder suitable for the methods above. Scrap typically contains contaminants such as Co and/or Ti, and comes in large or different sizes that can be difficult to process or sort.
In one embodiment, the scrap can be processed using an electrolysis method, wherein Co, Ni, Fe and Cu are dissolved in solution to obtain WC and TiC in flake shape. The WC and TiC mixture is taken out and put in a sodium nitrate and/or sodium carbonate solution. The reaction will result in a sodium tungstate NaWO 3 solution and non-dissolvable titanium oxide TiO, thus separating W and Ti. Sodium tungstate NaWO 3 and dihydrate calcium chloride CaCl are then caused to react, resulting in calcium tungstate CaWO 3 . Calcium tungstate CaWO 3 and hydrochloric acid HCl react to result in tungstate HWO 3 . The tungstate HWO 3 is cleaned and dried, and the dried tungstate HWO 3 is heated to high temperature to produce tungsten oxide WO 3 . The tungsten oxide WO 3 is reduced to obtain tungsten powder. Further details on tungsten scrap is described in U.S. Pat. No. 6,447,715, the entirety of which is hereby incorporated by reference.
In another embodiment, tungsten carbide itself may be used instead of tungsten as a raw material. For example, the tungsten powder as described above can be replaced with a tungsten carbide powder, and be used as the core in a two-layer or three-layer shot, the intermediate layer in a three-layer shot, or as the primary component in a single layer, uniformly distributed shot. In an embodiment where tungsten carbide is used in the core of a two-layer shot or the intermediate layer of a three-layer shot, the surface layer may be comprised substantially of only Fe and Cu, without substantially any tungsten.
Tungsten carbide advantageously has a density of about 15.7 g/cm 3 , which desirably provides a high density product. When formed into a multiple-layer composite shot such as described above, the tungsten carbide can be used as a higher density component, which when combined with a lower density component, can provide a desired aggregate density.
It will be appreciated that compositions with combinations of materials other than those described above may be used. For example, in one embodiment zinc is incorporated into the shot. Nickel, copper and zinc powders may be provided to alloy the layers in solid state sintering. Such an embodiment may include about 15% to 35% Ni, about 40% to 60% Cu, and about 20% to 35% Zn.
Embodiments of the shots described above advantageously provide a shot which is extremely uniform in dimension, density, and surface hardness for cartridge loading and therefore superior in density pattern. The processes described above are dedicated processes, with definitive process input and output criteria, enabling mass production of shots. Therefore, there is no limit on the production size. The shots are advantageously as dense as lead alloy or higher. Shots as produced herein may be provided in multiple layers, making them structurally extremely strong and capable of withstanding impact with maximum penetration power. Shots can be provided with a thick, relatively soft outer layer protect the gun barrel.
It will further be appreciated that articles produced with the compositions and/or methods described above can be used in a variety of other applications. For example, embodiments of the present invention may be applicable to technologies involving radiation shields, x-ray marker, counter weights, ballast weights, golf club weights, golf ball cores, fishing weights, and diving belt weights.
It will be understood that the foregoing is only illustrative of the principles of the invention, and that various modifications, alterations, and combinations can be made by those skilled in the art without departing from the scope and spirit of the invention. | High density, nontoxic projectiles and other articles, and their methods of manufacture, are disclosed. More particularly, high density nontoxic W—Cu—Ni—Fe alloy compositions, methods of their manufacture and methods by which they may be used as projectiles such as shots, bullets, and pellets and other products traditionally made of lead alloys will be detailed herein in some embodiments. These products have a density comparable to that of lead while avoiding problems of toxicity associated with the use of lead. | 5 |
INTRODUCTION
[0001] This invention relates to a method of using wastewater sludge in the production of concrete.
[0002] Nowadays, people are looking at finding ways of recycling their refuse in a more environmentally friendly manner. One of the main sources of pollutant is wastewater sludge which covers a variety of substances ranging from raw sewage sludge containing human or animal waste and faecal matter, to waste products created by industry. Wastewater sludge comes in many forms including wastewater sludge, sludge cake and dried sludge cake. Predominantly though, the wastewater sludge to which this invention relates is a wastewater sludge having a high water content in the region of in excess of 80% by weight of the wastewater sludge. That is, a sludge having a high proportion of water content by weight as opposed to normal household waste or the like which typically contains a high percentage, in the region of 90%, by weight of dry solids. This wastewater sludge must be disposed of in as environmentally friendly a manner as possible, whilst also being disposed of in as environmentally secure a manner as possible.
[0003] Until now, the most popular methods of disposal have been to dump wastewater sludge at sea or to send the wastewater sludge to landfill. Another popular method of disposal is to subject the wastewater to a biological process whereby the liquid and solids are separated before treating the liquids to extensive biological processes for subsequent recycling. The solids that have been separated off are usually incinerated or sent to landfill. However, these methods are becoming less viable as landfill space decreases and concern over dumping at sea increases.
[0004] Another method involves the incineration of the wastewater sludge at temperatures in excess of 1200° C. This involves the construction of expensive specially dedicated plants and has further raised concerns relating to air pollutants emitted from these plants. There is also produced a by-product from the incineration that must be disposed of by way of landfill or sea dumping.
[0005] One of the most problematic types of wastewater sludges to handle are those having a high water content by weight, as the water itself is contaminated and must be handled appropriately. The treatment of these types of wastewater sludge has heretofore included either the expensive incineration steps or the biological processes mentioned above so that the solid and liquid matter can be treated separately. Both of these are expensive particularly when dealing with such large volumes of high water content wastewater sludge such as that produced in industry. This excess water must be disposed of in an environmentally secure and friendly manner while still remaining feasible from a cost perspective. Previously, high water content wastewater sludge was pumped offshore but this practice has become more and more unacceptable.
[0006] Various attempts have been made to utilise the sludge as fertilisers and the like, although this usage is limited by governmental regulation and such use only accounts for a small percentage of the wastewater sludge produced. Before the sludge may be used as a fertiliser it must undergo composting which entails the decomposition of sewage sludge under appropriate conditions of moisture, temperature, volatile solids content and in the presence of oxygen by microorganisms. This is quite lengthy and time consuming.
[0007] Other uses of the sludge have also been proposed such as that described in British Patent No. 2,256,862 (British Gas Plc) which teaches a method of producing concrete containing sewage sludge ash which is the waste by-product subsequent to incineration of the sewage. This sewage sludge ash is used as a substitute for more expensive aggregates and is found to have good bonding characteristics. However, this involves the expensive incineration step to produce the sewage sludge ash which further increases the total cost of producing the concrete and disposing of the wastewater sludge.
[0008] U.S. Pat. No. 3,801,358 describes a method of making concrete using raw sewage and refuse. Once the concrete has cured, it is impregnated with a monomer and then heated or subjected to radiation to cause polymerisation. This will help to waterproof the concrete as well as improving sterilisation of the concrete. In order to facilitate impregnation of the monomer, the concrete block is placed in a vacuum and thereafter the concrete block is allowed to soak in the monomer for a period of time. This is a complex process that requires expensive equipment to produce the concrete blocks. Furthermore, each concrete block takes a significant period of time to make.
[0009] WO 90/15205 also describes a building element in which the main constituents comprise cement, waste sludge and fibre ingredients such as woodchip. In order to avoid direct contact with the building element, it is advised that the blocks should be plastered both inside and out in order to stabilise a structure built with these building elements, regular concrete must be poured into the blocks cavity, the strength of the building element being relatively moderate. The applicant describes how the blocks are subjected to compression for a treatment period of 24 hours. Again, these blocks will take a significant period of time to make and require coating with a plaster to render the blocks suitable for contact.
[0010] French Patent No. FR 7338465 describes a method of producing construction elements from household waste, agricultural waste or forestry waste. The waste is subjected to extensive preliminary treatments including dehydration, fragmentation and crushing until a rather coarse aggregate supplement having a particle size of in the region of 3-4 cm is produced. This dry solid material is then mixed with quicklime in order to quickly decay any organic or vegetation material present in the waste. Further aggregate, cement and water are added to the waste material before the mixture is press moulded to form the construction material. The problem with this type of method is that extensive pre-conditioning steps such as mixing and grinding must be carried out prior to the production of the building element which are both expensive and time consuming to carry out furthermore, the waste is household waste which is predominantly solids to start off with and therefore the problems associated with having to treat predominantly liquid wastewater sludge are not encountered. Due to the fact that the basic material used in the production of the construction element are particles 3-4 cm in size, the strength of the construction element may be compromised and a further expensive compression moulding step must be carried out to form the construction element which is highly disadvantageous. This patent does not suggest how industrial and other types of wastewater sludges having a high water content may be handled.
[0011] Heretofore, there has not been provided a method of using wastewater sludge in production of concrete that will provide a concrete that is ready to use that will require covering the concrete with plaster or subjecting the concrete to radiation other such treatment in order to render the concrete sufficiently sterile to u Furthermore, there has not yet been provided a method that can handle predomina liquid wastewater sludge in a safe and effective manner that is still cost effective carry out, the method not requiring significant dehydration steps prior to the product of the construction element and thereafter requiring further moulding or post mix treatments.
[0012] It is an object, therefore, of the present invention to provide a method of us wastewater sludge in the production of concrete that overcomes at least some of problems mentioned above and that is inexpensive and satisfies the environment requirements for disposal of wastewater sludge. It is a further object of the invention provide a method of using wastewater sludge, and in particular wastewater sludge having a high water content, in the production of concrete that requires the absol minimum number of treatment steps and does not require any expensive dehydra of the wastewater prior to commencement of the method.
STATEMENTS OF INVENTION
[0013] According to the invention, there is provided a method of using wastewater sludge the production of concrete comprising mixing cement, aggregate and wastewater sludge to form a concrete mix characterised in that:
the additional step is carried out of mixing the wastewater sludge an alkaline solution to achieve a wastewater sludge and alka solution mixture having a pH equal to or in excess of 11.5, prior mixing with the aggregate and the cement.
[0015] By using this method, the invention obviates the need for expensive incineration st or further pre-treatment steps and utilises untreated raw wastewater sludge in concrete. The concrete can then be used as a building product and thus avoids need for having to send the wastewater sludge to landfill. Furthermore, by adding an alkaline solution to the wastewater sludge, there is no need to provide further sterilisation steps such as subjecting the concrete to heating or radiation. The concrete provided will furthermore not have to be covered in plaster to render it safe. By premixing the wastewater sludge with an alkaline solution to form a wastewater sludge and alkaline solution mixture prior to mixing with the aggregate and the cement, the alkaline solution is put to best effect to act on the wastewater sludge and neutralises the harmful substances contained therein. This enhances the efficiency of the alkaline solution which is therefore required in lesser amounts. By achieving a wastewater sludge and alkaline solution mixture having a pH equal to or in excess of 11.5 a very high degree of sterilisation is achieved sufficient to render the wastewater sludge acceptable for use in the production of concrete. Therefore, both an environmentally friendly and economically efficient method is provided.
[0016] Essentially there is provide a very simple invention. The previously known methods of using wastewater sludge in the production of concrete have required elaborate, and often relatively expensive processes to render the concrete suitable for use. The problem of providing a concrete that is ready to use that will not pose a contamination risk is solved by the invention described above. Furthermore, the problem of having to provide expensive machinery and lengthy sanitising steps are obviated by the solution provided.
[0017] In one embodiment of the invention, the alkaline solution is a concrete hardener. It has been found that a concrete hardener may act as the alkaline solution and kill bacteria present in the concrete mixture. Furthermore, the concrete hardener will help to harden the concrete mixture in due course and will not have a detrimental effect on the quality of the concrete produced.
[0018] In another embodiment of the invention, the alkaline solution has a pH of between 12.5 and 14. Preferably, the alkaline solution has a pH of between 13.5 and 14. This will help to raise the pH level of the concrete mixture produced and will further improve the kill of bacteria in the wastewater sludge. The bacteria will be killed off in a very short period of time, thereby obviating the need for extensive storage times and further sterilisation techniques.
[0019] In a further embodiment of the invention, a bonding agent is added to the concrete mix. By adding a bonding agent to the concrete, there will be provided better adhesion of the component particles in the concrete. Preferably, the bonding agent used is carboxylated styrene butadiene alkali and will have a pH level in the region of 8 and 11. This will further help to improve the pH level of the concrete mixture.
[0020] In one embodiment of the invention, the wastewater sludge is in the form of dry sludge cake and water is added to the dry sludge cake, prior to the mixing of the sludge with the cement and the aggregate. By adding water to the wastewater sludge, the correct amount of water will be present to produce a uniform concrete each time, thereby ensuring good quality concrete each time. Preferably, sufficient water is added to the wastewater sludge to bring the water content of the diluted wastewater sludge to 80%. or more water by weight.
[0021] In another embodiment of the invention, a polymer is added to the wastewater sludge. The polymer will further act as a bonding agent to the concrete providing improved adhesion properties to the concrete's components.
[0022] In a further embodiment of the invention, the concrete is stored for between 28 days and 6 months. By storing the concrete for a sufficient period of time, the concrete will be able to set which will further ensure that all bacteria are killed off and that the concrete adheres to health and safety standards.
[0023] In one embodiment of the invention, the aggregate comprises one or more of grey wacke stone, sand, sandstone, gravel, limestone, crushed shale, crushed seashells, pencil, kiln dried sand, grit, pulverised fuel ash, slag from steelworks, quicklime and recycled crushed concrete. Preferably, the aggregate will comprise limestone which is seen as particularly useful to produce a robust, strong concrete. The limestone furthermore has a suitable pH value to further sterilise the wastewater sludge when being used in the production of concrete.
[0024] In a further embodiment of the invention there is provided a method of using wastewater sludge in the production of concrete in which additional cement is used instead of aggregate in the concrete mixture. This may in some instances be more economical than providing further aggregates whilst also providing a useable concrete mixture that contains a high content of wastewater sludge.
[0025] In another embodiment of the invention, a detergent is added to the concrete mix prior to curing. By providing the detergent, further bacterial kill may be achieved, again providing a concrete suitable for use in goods and products that conform to health and safety standards.
[0026] In a further embodiment of the invention, the alkali solution added to the wastewater sludge is Sika [Registered Trade Mark™]. This is seen as particularly useful as Sika is both in inexpensive and effective in its function. The active ingredients of the strong alkali preferably include one or more of using potassium hydroxide, sodium aluminate and potassium carbonate. Alternatively, instead of using Potassium Hydroxide to stabilise and sterilise the wastewater sludge, Sodium Hydroxide, Calcium Hydroxide or Barium Hydroxide could be used. It is envisaged that the alkali solution could comprise an electrically charged (ionised) water/salt solution.
[0027] In one embodiment of the invention, the alkali solution is added to the wastewater sludge in the ratio of between1:200 and 5:200 parts alkali solution to parts wastewater sludge. Preferably, the alkali solution is added to the wastewater sludge in the ratio of 3:200. These amounts are sufficient to see good bacterial kill in the final concrete mixture.
[0028] In another embodiment of the invention, the wastewater sludge, cement and aggregate are mixed in a ratio of 1:1:6 by weight to form the concrete mix. This is seen as a particularly efficient mix and will provide a robust concrete product suitable for most uses.
[0029] In a further embodiment of the invention, the blended concrete mix is sealed in a heavy duty plastic container. This will further prevent any leaching of the concrete and will minimise the risk of contamination to the environment from any harmful products remaining in the wastewater sludge and the concrete.
[0030] In one embodiment of the invention, there is provided a concrete product made in accordance with the method as described above. By having such a product, an inexpensive concrete product is provided, while also providing an alternative way of disposing of the wastewater sludge in a more environmentally friendly and cost efficient manner.
[0031] In another embodiment of the invention, the wastewater sludge comprises between 8% and 55% of the concrete mixture. In one embodiment the wastewater sludge comprises between 8% and40% of the concrete mixture. In a further embodiment the
[0032] wastewater sludge comprises between 8% and 25% of the concrete mixture. Alternatively, the waster sludge fnay comprise between 11% and 14% of the concrete mixture. Preferably, the wastewater sludge will comprise 12% by weight of the concrete mbcture. This allows for a large quantity of wastewater sludge to be incorporated into the concrete, while stir maintaining all the strength properties necessary forthe concrete to be used in construction.
[0033] In another embodiment of the invention there is provided a method of using wastewater sludge in the production of concrete in which the percentage of liquid content of the wastewater sludge is between 50% and 97° h and the percentage of solid matter in the wastewater sludge is between 3% and 50%. In this way a large amount of the liquid required for the manufacture of the concrete may be taken from the Wastewater sludge. This is a useful way of using up the water content of the wastewater sludge and avoiding alternative expensive techniques to remove the water from the sludge. Preferably the percentage of liquid content in the sludge is between 80 and 97%.
[0034] In a further embodiment of the invention there is provided a method of using wastewater sludge in the production of concrete in which the alkaline solution is mixed with the wastewater sludge so that a wastewater sludge and alkaline solution mixture having a pH equal to or greater than 12 is achieved. In one embodiment, sufficient alkaline solution is added to achieve a wastewater sludge and alkaline solution mixture having a pH equal to or in excess of 12.5. This will ensure that a sufficient degree of the hazardous materials contained in the wastewater sludge will be neutralised prior to the concrete mixture being formed. These hazardous materials can be neutralised in a quick and efficient manner that can be accurately estimated.
DETAILED DESCRIPTION OF THE INVENTION
[0035] The invention will now be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying in which there is shown a diagrammatic illustration of one form of suitable apparatus that may be used for carrying out the method of the invention.
[0036] Wastewater sludge is fed from a container 1 to a mixing truck 2 by way of a conveyor 3 . The conveyor 3 has load cells (not shown) connected thereto to carefully monitor the amount of wastepaper being delivered to the mixing truck 2 . The wastewater is placed in a paddle mixer 4 of the mixing truck 2 wherein it is blended with an alkali solution. Once the wastewater and alkali solution have been mixed sufficiently, a pump 5 on the mixing truck 2 is actuated to pump the wastewater and alkali mixture through a flexible hose pipe 6 to a mixing drum 7 of a nearby concrete mixing truck 8 . The mixing drum 7 has already contained therein a thoroughly blended mixture of cement and aggregate. Once the alkali solution and the wastewater have been added to the mixing drum 7 containing the aggregate and cement, the mixing drum 7 is rotated, thereby blending the materials contained therein to form a concrete mixture.
[0037] The relative amounts of wastewater sludge, cement and aggregate are determined, depending on the strength and curing time requirements of the individual producing the concrete. The alkali solution blended with the wastewater sludge can be a concrete hardener such as that sold under the brand name Sika™. The alkali will further act as a hardener assisting in the curing time of the concrete mix once the wastewater sludge and the dry mix have been blended together. The wastewater sludge will be stabilised in that heavy elements such as phosphorus are physically stabilised within the matrix of the concrete and the sludge will also be sterilised in that the bacteria, viruses or other ling organisms normally present in the sludge will be killed.
[0038] In addition to the strong alkali, a bonding agent such as those sold under the Registered Trade Marks EVOSTICK, RONAFIX, or Polyvinyl Acetate are further added to the wastewater sludge to improve the pH value of the concrete to be produced, whilst also improving the bonding properties of each of the main components of the concrete. This concrete mix may then be used to construct road side barriers, concrete verges, and the like.
[0039] A liquid detergent such as those produced by JEYES™, DETTOL™ or FLASH™ is added to the unsolidified concrete mix to further eliminate any residual bacteria present in the wastewater sludge. The liquid detergent may be added to the concrete mix regardless of whether the alkali substances have been added. The concrete may then be poured into a heavy duty plastic container and sealed therein to avoid any risk of contamination to the environment by teaching of the concrete once it has been exposed to the elements.
[0040] Some examples of a concrete mixture produced in-accordance with the invention will now be given.
EXAMPLE 1
[0041] 1 Kg of wastewater sludge is mixed with 0.3 Kg of bonding agent in a suitable container. Once the bonding agent and wastewater sludge have been sufficiently mixed together, 0.3 Kg of concrete hardener is added to the mixture and stirred in thoroughly to assist in the hardening process, as well as killing any bacteria present in the mixture. Separately, 6 Kg of aggregate is mixed with 1 Kg of cement to form a dry mix. This dry mix is then mixed with the wastewater sludge, hardening agent and bonding agent and blended together until a concrete mixture is formed. This concrete mixture may then be used for road construction or other suitable purpose.
[0042] A sample of concrete made in accordance with the above example provided the following toxicity results for the main heavy metal contamination types, as shown in Table 1 below.
TABLE 1 Max. Value in Max. Value in Value Leached Parameter Sludge Soil from Concrete Cadmium 20 1 0.176 mg/Kg Copper 1000 50 0.846 mg/Kg Nickel 300 30 0.96 mg/Kg Lead 750 50 0.18 mg/Kg Zinc 2500 150 0.95 mg/Kg Mercury 16 1 <0.025 mg/Kg Chromium 3.5 kg/ha/yr 1.66 mg/Kg
[0043] Furthermore, various cube strength tests on random samples of the concrete were taken after hardening for 28 days. The measured strengths ranged from 3.0 to 6.0 N/mm 2 with an average of 4.5 N/mm 2 . It will be understood that by having more concrete contained within the mix, the average cube strength test results of 7 or 8 N/mm 2 were attainable. This provides an aggregate impact value of less than 25% which is sufficient for use as heavy duty concrete floor finishes in most jurisdictions. Furthermore, the 10% fines value in excess of 130 KN is also easily attainable with careful selection of aggregate.
EXAMPLE 2
[0044] Five litres of Sodium Aluminate, five litres of Potassium Hydroxide and five litres of Potassium Carbonate are mixed together in a suitable mixing vessel. One ton of sludge cake at 15 to 20% dry solids is added to the mixed Sodium Aluminate, Potassium Hydroxide and Potassium Carbonate solution and blended with some aggregate until a viscous liquid is formed. Five litres of bonding agent and 5 to 10 litres of water are then added to the viscous liquid. Separately, six tons of aggregate is mixed with one ton of cement to form a dry mix that has the aggregate and cement evenly mixed throughout The blended mixture containing the sludge cake is then added to the dry mix for a period of between five to ten minutes to form a concrete mixture. The concrete mixture is then ready to be poured. Similar toxicity results for the main heavy metal contamination types as shown for the previous example in Table 1 were achieved for the concrete mixture of Example 2.
[0045] It is envisaged that the mixing of the cement and aggregate could be performed in a standard concrete mixing truck or other such similar device. The sewage sludge could be added to the dry mix once any additional hardening agents or bonding agents had been thoroughly mixed in with the sewage sludge. The hardening and bonding agents could be pre-mixed with the sewage sludge in a separate mixing vessel before being pumped into the concrete mixing truck with the dry mix it is envisaged that the hardening and bonding agents are mixed with the sewage sludge at between 500 and 1000 revolutions per minute to thoroughly mix the components together. Additional water may be added to the sewage sludge, if necessary, prior to mixing with any hardening or bonding agents.
[0046] It will be understood the aggregates used could be any one from a selection of crushed grey wacke stone, kiln dried sand, normal sand, limestone, gravel, grit, crushed sandstone, crushed pencil, crushed shale, crushed seashells, crushed concrete, pulverised fuel ash, quicklime or any other suitable type of stone. Slag from steel processing which is the silicate waste from steel blast furnaces could also be used as one alternative aggregate material. Reinforcing materials such as glass fibre or steel can also be added as part of the aggregate to further strengthen the concrete. The aggregates used will largely depend on the desired characteristics of the concrete to be produced. The concrete produced in accordance with the invention may itself be crushed subsequent to setting and thereafter may be used as a fill material for road surfaces.
[0047] The blended concrete mix could also be sealed in a heavy duty plastic container to prevent any risk of harmful materials being leached out of the concrete. As an alternative to a heavy duty plastic container a fibreglass coating or plastic coating may be applied to concrete produced in accordance with the method to add further protection and additional strength to the concrete.
[0048] In this specification, the term “hardening agent” has been used to define a substance that will reduce the time necessary for the concrete mixture to set. A concrete bonding agent is used to describe a substance that is used to enhance the cohesion of the individual ingredients, once mixed. In the examples described above it will be understood that various ingredients in the hardening agent act as stabilising and sanitizing components whereas various other ingredients act as hardening components. Potassium Carbonate or Aluminium Silicate would act as hardening components whereas Potassium Hydroxide would act as a stabilising and sanitising component. Other alkalines that could be substituted for the Potassium Hydroxide include Sodium Hydroxide, Calcium Hydroxide or Barium Hydroxide or other similar substances.
[0049] In this specification the terms “comprise, comprises, comprised and comprising” as well as the terms “include, includes, included and including” are deemed totally interchangeable and should be afforded the widest possible interpretation.
[0050] The invention is in no way limited to the embodiment hereinbefore described, but may be varied in both construction and detail within the scope of the claims. | A method of using wastewater sludge in the production of concrete comprising mixing cement, aggregate and wastewater sludge to form a concrete mix in which the additional step is carried out of mixing the wastewater sludge with an alkaline solution to achieve a wastewater sludge and alkaline solution mixture having a pH equal to or in excess of 11.5 prior to mixing with the aggregate and cement. Such a method is a simple and efficient method of producing ready usable concrete and will not require expensive sterilisation steps such as heat or radiation treatment. The wastewater sludge is disposed of in an environmentally friendly manner and will not undergo incineration or have to be dumped at sea or landfill. | 2 |
FIELD OF THE INVENTION
This invention relates to cardiac pacemakers and, more particularly, implantable cardiac pacemakers with programmable rate control.
BACKGROUND OF THE INVENTION
Pacemaker systems with rate control have become widely used in the art. Rate control may be provided by employing one or more rate responsive sensors, e.g., sensors which determine a parameter such as Q-T interval, exercise, etc., from which the desired pacing rate to match the patient's cardiac's demand can be determined. Such rate responsive pacemakers contain algorithms for converting the sensed parameters into pacing rate, e.g., increased activity results in a higher pacing rate. Further, it is known to program certain data relating to pacing rate from an external programmer, e.g., the values of lower rate limit (LRL) and upper rate limit (URL) can be programmed in this manner.
It has been determined that under special circumstances, it is desired to control pacing rate of an implanted pacemaker in accordance with a special function, i.e., at a rate or rates which would not otherwise be indicated. For example, it has been determined that following radio frequency catheter ablation of the atrioventricular junction, there is a certain incidence of ventricular fibrillation or sudden death. See, for example, the article of Peters et al., "Bradycardia Dependent QT Prolongation and Ventricular Fibrillation Following Catheter Ablation of the Atrioventricular Junction With Radiofrequency Energy," PACE, Vol. 17, January 1994; Jordaens et al., "Sudden Death and Long-Term Survival After Ablation of the Atrioventricular Junction," EUR.J.C.P.E., Vol. 3, Nov. 3, 1993; and Geelen et al., "Ventricular Fibrillation and Sudden Death After Radiofrequency Catheter Ablation of the Atrioventricular Junction," PACE, 1996. Indeed, it has been determined that for pacemaker patients with an LRL in the area of 60 bpm, post-ablation there is a risk of about 6% that the patient will develop bradycardia-dependent ventricular fibrillation. In such post-ablation circumstances, the patient's natural fast ventricular rate is replaced by the pacemaker rate. While lower rate pacing does not remove the danger, episodes of ventricular extra-systole (VES) and ventricular tachycardia can be suppressed by overdrive pacing at a higher rate, e.g., 80-90 bpm, or greater. Accordingly, it is known to program a lower rate limit to such a relatively high rate of about 90 bpm, and to then reprogram the lower rate limit back to a more normal rate, e.g., 60 bpm, following a month or so.
However, there remain certain problems with this post-ablation technique. First, the patient comfort may be sacrificed by maintaining the lower rate limit at the constant high rate for too long a period of time. Further, the patient then needs to be re-programmed by the physician, at which time LRL is abruptly dropped to a lower value, e.g., 60 bpm. Further, this procedure provides no flexibility, and does not account for the fact that the high rate overdrive need is not constant, but can be adjusted downward over a time period of approximately a month. Further, the prior art does not take into account the effects of patient exercise. Since the patient remains vulnerable to bradycardia-dependent fibrillation, the rate response during exercise should be adjusted to be more appropriate to this particular situation.
Accordingly, there is a need for a pacemaker system and method for providing special function rate control, to be used for situations such as a post-ablation period or other special diagnosed circumstances where normal rate control is unsatisfactory.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an implantable pacemaker system and method for carrying out special function rate control for dealing with situations such as faced by patients following catheter ablation of the atrioventricular junction. Specifically, the object is to provide a pacemaker which can be enabled to switch into a specialized rate control routine for varying minimum pacing rate, as well as varying the rate response during periods of patient exercise. For the special function of dealing with a post-ablation period, the pacemaker system of this invention provides for an initial high low rate limit, e.g., 80-110 ppm followed by a gradual decay of LRL over a predetermined period such as one month.
The special function rate feature of this invention can be enabled by external programming directly after the event or determination that requires the special function, e.g., following an ablation procedure. In a preferred embodiment, the escape interval is initially set to a value corresponding to a high LRL of at least 80 bpm (or ppm--pulse per minute), which escape interval increases in accordance with a predetermined decay function over a given time duration to a value corresponding to a normal lower rate limit. As a specific example, the system can be enabled to start at a rate corresponding to about 93.75 bpm, which rate is then decremented every two hours by incrementing the escape interval 1 ms, whereby after 30 days the rate is down to 60 bpm.
For a preferred embodiment of a rate responsive pacemaker, the pacemaker stores a normal rate response (RR) algorithm for correlating a sensed parameter into pacing rate, as well as one or more selectable special function algorithms. When the special function rate control of this invention is enabled, the selected rate response function is more aggressive, i.e., it reacts more aggressively to exercise so as to take pacing rate more quickly toward the upper rate limit after the onset of exercise.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the primary components of a pacemaker in accordance with this invention.
FIG. 2 is a flow diagram showing the primary steps taken in a rate responsive pacemaker in accordance with this invention, including the steps of enabling the pacemaker to go into special function rate control.
FIG. 3 is a flow diagram illustrating rate responsive override of the pacing rate in accordance with this invention.
FIG. 4a is a diagram illustrating a linear and a curvilinear decay function in accordance with this invention.
FIG. 4b is a diagram illustrating a more aggressive rate response in accordance with this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to FIG. 1, there is shown a block diagram of an illustrative pacemaker system for use in the practice of this invention. The block diagram of FIG. 1 shows the primary functional components of a pacemaker, which components and their interconnections are well known in the pacemaker art. A VP generator 30 produces ventricular pace pulses under control of control block 40. The output of generator 30 is connected through a pacing lead L v to a ventricular electrode or electrodes indicated at 31, for pacing of the patient's ventricle. The electrode or electrodes 31 also sense signals in the patient's ventricle, natural and evoked. Signals sensed at electrodes 31 are connected to a QRS sense amplifier circuit 35, as well as to a T-wave sense amplifier 36. By a technique well known in the art, amplifier 35 is enabled for a window corresponding to the expected arrival of the QRS, under control of circuit 40; similarly the T-wave amplifier is enabled for a window of time around the expected T-wave, likewise under the control of circuit 40. Thus, ventricular senses (VS) and T-waves are detected and inputted into control 40, for use by the pacemaker. For a dual chamber pacemaker, there is also an atrial pulse generator 32, which delivers atrial pace pulses under control of control circuit 40. These pulses are connected through an atrial lead L A to atrial electrode or electrodes designated at 33. Natural P-waves, or evoked atrial responses, are sensed by the atrial electrodes 33, and connected to P-wave sense amplifier 37, the output of which is connected back to control block 40.
Control block 40 performs the various logic and processing functions of a modern pacemaker, and suitably comprises a microprocessor. The microprocessor circuit itself contains some memory, and there may be additional memory, RAM/ROM, as indicated at block 41. The allocation of hardware and software to the structure and control block 40 is a matter of design choice, and not important to the scope of this invention. Also shown are one or more sensors 42, for determining one or more parameters from which rate responsive control can be achieved, again in a known fashion. Additionally, the stimulus-T, or Q-T interval can be derived and used as the RR parameter, in a known manner. Block 44 illustrates a receiver-transmitter for communicating with an external programmer by telemetry, in a known fashion. Thus, program instructions from an external transmitter are received at 44 and coupled into control block 40; likewise data collected by the pacemaker concerning pacemaker operating variables and/or diagnostic data may be downloaded through unit 44 to the external programmer, in a known manner.
In the practice of this invention, an external command for putting the pacemaker into a special function rate control mode is received at receiver-transmitter 44, and conveyed to the control unit 40. The normal rate response algorithm, and the selectable special function response algorithm, are stored in memory 41, and selected in response to a programmed signal. It is to be understood that while a decay response appropriate for a post-ablation patient is presented as the preferred embodiment, any other special function program may be stored and enabled upon appropriate command.
Referring now to FIG. 2, there is shown a flow diagram of the primary steps taken in controlling rate in accordance with this invention. The steps preferably carried out under software control. It is to be understood that the pacemaker is programmed with normal values for LRL and URL, as well as a normal rate response correlation function for correlating a sensed parameter such as activity with a rate response rate. At block 50, the pacemaker determines whether a rate decay, or special rate function is programmed. If no, the pacemaker utilizes the normal rate response algorithm, whatever that may be, as indicated at block 54. However, if a special function is programmed, the pacemaker sets the decay flag, or special function flag as indicated at block 51, which enables the special function routine. When this flag is set, the pacemaker sets the escape interval to a starting value, e.g., 640 ms, as indicated at 53. Six hundred forty ms corresponds to a starting rate of 93.75 bpm. As stated above, the start value for pacing rate during the duration of special rate function pacing is to be high enough to override ventricular fibrillation. The starting rate may be set by the physician, and may suitably be in the range of 80-110 bpm, or higher. The indicated starting rate of 93.75 is exemplary, and corresponds to a linear decay over one month down to an end value of 60 bpm.
Still referring to FIG. 2, at step 55 the pacemaker times out an interval, e.g., 2 hours. Upon timeout of this interval, as indicated at 56 the escape interval is incremented by 1 ms. Following this, it is determined whether the escape interval is equal to or greater than the end value, an exemplary end value being 1,000 ms which corresponds to 60 bpm. If no, the routine branches to block 58, and determines whether the special function is to be reprogrammed. If no, the routine goes back to 55, and commences timeout of the next 2-hour interval. If yes, the routine goes back to 51 and again enables the special decay function, which at this point may be a reprogrammed function. Reprogramming may consist simply of starting a new decay routine, changing the time duration, changing the start rate or the end rate, or any combination of these special function variables.
In the absence of reprogramming, the routine of FIG. 2 continually re-loops, timing out 2-hour intervals, following each interval with an increase of the escape interval by 1 ms. In this manner, after 30 days, the escape interval is incremented to 1,000 ms, corresponding to 60 bpm. While this linear decay is illustrated as exemplary, it is to be understood that any other desired decay function can be utilized in accordance with this invention. After the pacing rate has increased to the end value, at block 59 the rate decay flag is reset, such that the pacemaker then goes to a normal rate response mode.
Referring now to FIG. 3, there is shown a flow diagram illustrating the inclusion of rate response as derived from one or more rate-indicating sensors. This flow diagram shows steps which are taken every pacemaker cycle during the duration of this special function. At 60, the pacemaker gets the rate response escape interval, indicated as RR -- int. Then, at 61, RR -- int is compared to the escape interval, the escape interval being set by the special function, or decay routine as seen at block 56 of FIG. 2. If RR -- int is not less than the escape interval, the routine skips to block 64. However, if this comparison indicates that the RR -- int is less than the escape interval, then at 62 the escape interval is set equal to RR -- int. At 64, the escape interval is timed out. At 65, it is determined whether there has been a sense. If yes, then pacing is inhibited in the normal fashion. If no, then a pace pulse is delivered as indicated at 67. Then, at 68, it is determined whether the pacemaker remains in the rate decay or special function mode. If yes, at 72 the rate decay RR correlation is enabled; if no, then at 70 the normal RR correlation is enabled.
Referring to FIG. 4a, there is shown a pair of curves indicating linear and non-linear versions of a decay function. The straight line indicated at A indicates a linear decrease in pacing rate from 93.75 down to 60 bpm, over 30 days, as described above. The curve at B shows a non-linear change, wherein higher pacing rates are maintained for a longer time, as compared to the curve at A. The exact function can, of course, be determined as a matter of choice, suitably matching the physician's experience with such cases. Note that if the decay function is reprogrammed at any time, the doctor can select a plurality of different responses stored in memory. Of course, for other patient conditions requiring different pacing strategies, the response is formulated to carry out the prescribed strategy.
Referring to FIG. 4b, there are shown several different forms of rate response overdrive. The straight line shows a normal rate response correlation function, where increases in the rate response parameter (e.g., activity) correspond to linear increases in rate. As indicated, the rate increases linearly from 60 to 140 bpm, as a function of the rate response parameter. By contrast, the dashed line indicated as "decay A" shows a more aggressive correlation function, which kicks in at 90 bpm. Thus, for this rate response, and assuming the decay rate is 90 bpm, when the rate response parameter indicates a pacing rate greater than 90 it is more aggressive in being incremented toward the upper rate limit. This response may be tied to the decay rate, i.e., if the decay rate is down to 80 bpm from a higher starting point, then the more aggressive rate response function takes over anytime a rate greater than a rate of 80 is indicated. The curve marked "decay B" is a variation, wherein once the rate response parameter rises above a predetermined threshold (Th), the rate indicated by the RR parameter jumps incrementally, e.g., to 90 bpm, and then curves up toward the upper rate limit. These curves are examples, and are intended to illustrate that the precise nature of the special function rate response correlation is something that can be programmed to take into account patient history or any other known facts.
It is to be understood that the special RR function can be implemented without the decay function. Thus, a patient condition may not present a need for a special LRL, but may suggest a special rate response to exercise or other conditions. In this case, the decay program is bypassed, but the special function RR correlation is enabled for a predetermined duration, or until reprogramming by the physician. | There is provided a pacemaker system and method for enabling special rate control for patients who have specially recognized conditions, e.g., patients who are post-ablation and thus are susceptible to bradycardia-dependent ventricular fibrillation or other arrhythmias. In a preferred embodiment, the pacemaker has a special function rate control algorithm which, for the post-ablation patient, commences pacing with a lower rate limit at a high start value of around 80-100 bpm, and decays the lower rate limit down to an end value of about 60-70 bpm over a duration of about a month. Additionally, the pacemaker is provided with one or more selectable special function rate response algorithms, for enabling higher rate response to patient exercise and demand for increase cardiac output. The combination of the gradual decay of lower rate limit over the programmable duration as well as the specially programmable rate response enables optimization of pacing so as to prevent arrhythmias. | 0 |
BACKGROUND
[0001] The present invention generally relates to materials for use in shielding from heat and/or flame, and in particular, heat and/or flame shielding material that can be used in applications such as hood liners for automobiles, engine compartment liners, and the like.
[0002] Numerous industries require materials which not only deliver heat and flame resistant properties, but can also provide volume, opacity, moldability, and other properties in a cost effective single substrate. Often times these barrier properties are best accomplished by using specialty materials which generate a high level of performance, but also introduce significant cost to the substrate. Especially in a voluminous substrate (high z direction thickness) even the introduction of a small percent of these materials into the shield material can introduce a significant level of cost to the overall substrate. For this reason composites having specialty surface layers are often used to provide these barrier properties. An example of a composite having specialty surface layers would be a skin laminated to a voluminous lower cost material. While this method effectively reduces the cost of the high cost raw material, there are disadvantages to this method such as additional processing steps and the potential delamination of the skin layer.
[0003] The present invention provides an alternative to the prior art by using a unitary heat shield material with different zones to provide the various desired properties of the material
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:
[0005] FIG. 1 shows an enlarged cross-section of one embodiment of the present invention;
[0006] FIG. 2 shows an enlarged cross-sectional view of another embodiment of the present invention; and,
[0007] FIG. 3 shows a diagram of a machine for performing a process for forming the planar heat and flame resistant shield material of the present invention.
DETAILED DESCRIPTION
[0008] Referring now to the figures, and in particular to FIG. 1 , there is shown an enlarged cross-sectional view of an embodiment of the present invention, illustrated as a planar heat and flame shield material 100 . The shield material 100 may be used in its existing sheet form as a protective blanket or shield in operations such as welding, high temperature manufacturing, or the like. The shield material 100 may also be formed into parts such as automotive hood liners, engine compartment covers, and the like. As illustrated, the planar shield material 100 generally contains heat and flame resistant fibers 101 and bulking fibers 102 . The heat and flame resistant fibers 101 and the bulking fibers 102 are staple fibers that are combined to form the shield material 100 . As used herein, heat and flame resistant fibers shall mean fibers having an Limiting Oxygen Index (LOI) value of 20.95 or greater, as determined by ISO 4589-1. Examples of heat and flame resistant fibers include the following: fibers including oxidized polyacrylonitrile, aramid, or polyimid, flame resistant treated fibers, carbon fibers, or the like. Bulking fibers are fibers that provide volume to the heat shield material. Examples of bulking fibers would include fibers with high denier per filament (one denier per filament or larger), high crimp fibers, hollow-fill fibers, and the like. In one embodiment, the heat and flame resistant fibers 101 and the bulking fibers 102 are air-laid with a binder fiber 105 , and the combination of fibers is heated to activate the binder fiber 105 for bonding together the fibers of the shield material 100 . An additional benefit of using the binder fiber 105 in the shield material 100 is that the shield material 100 can be subsequently molded to part shapes for use in automotive hood liners, engine compartment covers, etc.
[0009] Still referring to FIG. 1 , the heat and flame resistant fibers 101 are concentrated in a heat and flame resistant zone 110 of the planar shield material 100 , and the bulking fibers 102 are concentrated in a voluminous bulking zone 120 of the planar shield material 100 . The heat and flame resistant zone 110 provides the shield material 100 with the primary heat and flame resistant attributes. The voluminous bulking zone 120 provides the shield material 100 with the desired z-direction thickness.
[0010] Referring still to FIG. 1 , the heat and flame resistant zone 110 has an outer boundary 111 located at the outer surface of the shield material 100 , and an inner boundary 112 located adjacent to the voluminous bulking zone 120 . The voluminous bulking zone 120 has an outer boundary 121 located at the outer surface of the shield material 100 and an inner boundary 122 located adjacent to the heat and flame resistant zone 110 . The shield material 100 is a unitary material, and the boundaries of the two zones do not represent the delineation of layers, but areas within the unitary material. Because the shield material 100 is a unitary material, and the heat and flame resistant zone 110 and the voluminous bulking zone 120 are not discrete separate layers joined together, various individual fibers will occur in both the heat and flame resistant zone 110 and the voluminous bulking zone 120 . Although FIG. 1 illustrates the heat and flame resistant zone 110 being a smaller thickness than the voluminous bulking zone 120 , the relative thickness of the two zones can have a substantially different than as shown.
[0011] Referring still to FIG. 1 , the heat and flame resistant zone 110 contains both the heat and flame resistant fibers 101 and the bulking fibers 102 . However, the heat and flame resistant zone 110 primarily contains the heat and flame resistant fibers 101 . Additionally, the distribution of the fibers in the heat and flame resistant zone 110 is such that the concentration of the heat and flame resistant fibers 101 is greater at the outer boundary 111 of the heat and flame resistant zone 110 than the inner boundary 112 of that zone. Also, as illustrated, it is preferred that the concentration of the heat and flame resistant fibers 101 decreases in a gradient along the z-axis from the outer boundary 111 of the heat and flame resistant zone 110 to the inner boundary 112 of that zone.
[0012] Still referring to FIG. 1 , the voluminous bulking zone 120 contains both the heat and flame resistant fibers 101 and the bulking fibers 102 . However, the voluminous bulking zone 120 primarily contains the bulking fibers 102 . Additionally, the distribution of the fibers in the voluminous bulking zone 120 is such that the concentration of the bulking fibers 102 is greater at the outer boundary 121 of the voluminous bulking zone 120 than the inner boundary 122 of that zone. Also, as illustrated, it is preferred that the concentration of the bulking fibers 102 decreases in a gradient along the z-axis from the outer boundary 121 of the voluminous bulking zone 120 to the inner boundary 122 of that zone.
[0013] Referring now to FIG. 2 , there is shown an enlarged cross-sectional view of another embodiment of the present invention, illustrated as a heat and flame shield material 200 . As illustrated, the shield material 200 generally contains heat and flame resistant fibers 201 and bulking fibers 202 . The heat and flame resistant fibers 201 and the bulking fibers 202 are staple fibers that are combined to form the shield material 200 . In one embodiment, the heat and flame resistant fibers 201 and the bulking fibers 202 are air-laid with a binder fiber 205 , and the combination of fibers is heated to activate the binder fiber 205 for bonding together the fibers of the shield material 200 . An additional benefit of using the binder fiber 205 in the shield material 200 is that the shield material 200 can be subsequently molded to part shapes for use in automotive hood liners, engine compartment covers, etc.
[0014] Still referring to FIG. 2 , the heat and flame resistant fibers 201 are concentrated in a heat and flame resistant zone 210 of the shield material 200 , and the bulking fibers 202 are concentrated in a voluminous bulking zone 220 of the shield material 200 . The heat and flame resistant zone 210 provides the shield material 200 with the primary heat and flame resistant attributes of the shield material 200 . The voluminous bulking zone 220 provides the shield material 200 with the desired z-direction thickness.
[0015] Referring still to FIG. 2 , the heat and flame resistant zone 210 has an outer boundary 211 located at the outer surface of the shield material 200 , and an inner boundary 212 located adjacent to the voluminous bulking zone 220 . The voluminous bulking zone 220 has an outer boundary 221 located at the outer surface of the shield material 200 and an inner boundary 222 located adjacent to the heat and flame resistant zone 210 . The shield material 200 is a unitary material, and the boundaries of the two zones do not represent the delineation of layers, but areas within the unitary material. Because the shield material 200 is a unitary material, and the heat and flame resistant zone 210 and the voluminous bulking zone 220 are not discrete separate layers joined together, various individual fibers will occur in both the heat and flame resistant zone 210 and the voluminous bulking zone 220 . Although FIG. 2 illustrates the heat and flame resistant zone 210 being a smaller thickness than the voluminous bulking zone 220 , the relative thickness of the two zones can have a substantially different than as shown.
[0016] Still referring to FIG. 2 , the heat and flame resistant zone 210 contains both the heat and flame resistant fibers 201 and the bulking fibers 202 . However, the heat and flame resistant zone 210 primarily contains the heat and flame resistant fibers 201 . Additionally, the distribution of the fibers in the heat and flame resistant zone 210 is such that the concentration of the heat and flame resistant fibers 201 is greater at the outer boundary 211 of the heat and flame resistant zone 210 than the inner boundary 212 of that zone. Also, as illustrated, it is preferred that the concentration of the heat and flame resistant fibers 201 decreases in a gradient along the z-axis from the outer boundary 211 of the heat and flame resistant zone 210 to the inner boundary 212 of that zone.
[0017] Referring still to FIG. 2 , the bulking fibers 202 of the shield material 200 comprise first bulking fibers 203 and second bulking fibers 204 . In one embodiment, the first bulking fibers have a higher denier per filament, and/or mass per fiber, than the heat and flame resistant fibers 201 , and the second bulking fibers 204 have a higher denier per filament, and/or mass per fiber, than the first bulking fiber 203 and the heat and flame resistant fibers 201 . Also, the voluminous bulking zone 220 is divided into a first bulking zone 230 and a second bulking zone 240 . The first bulking zone 230 has an outer boundary 231 located adjacent to the heat and flame resistant zone 210 and inner boundary 232 located adjacent to the second bulking zone 240 . The second bulking zone 240 has an outer boundary 241 located adjacent to the outer surface of the shield material 200 and an inner boundary 242 located adjacent to the first bulking zone 230 . As previously stated, the shield material 200 is a unitary material, and as such, the boundaries of the two bulking zones do not represent the delineation of layers, but areas with in the unitary material. Because the shield material 200 is a unitary material, and the first bulking zone 230 and the second bulking zone 240 are not discrete separate layers joined together, various individual fibers will occur in both the first bulking zone and the second bulking zone 240 . Although FIG. 2 illustrates the heat and flame resistant zone 210 being a smaller thickness than the voluminous bulking zone 220 , the relative thickness of the two zones can have a substantially different than as shown.
[0018] Still referring to FIG. 2 , the first bulking zone 230 contains both the first bulking fibers 203 and the second bulking fibers 204 . However, the first bulking zone 230 will contain more of the first bulking fibers 203 than the second bulking fibers 204 . The distribution of the fibers in the first bulking zone 230 is such that the concentration of the first bulking fibers 203 increases in a gradient along the z direction from the outer boundary 231 of the first bulking zone 230 to a first bulking fiber concentration plane 235 located between the inner boundary 232 and the outer boundary of the first bulking zone. Also, as illustrated, it is preferred that the concentration of the first bulking fibers 203 decreases in a gradient along the z-axis from the first bulking fiber concentration plane 235 to the inner boundary 232 of that zone.
[0019] Referring still to FIG. 2 , the second bulking zone 240 contains both the first bulking fibers 203 and the second bulking fibers 204 . However, the second bulking zone 240 will contain more of the second bulking fibers 204 than the first bulking fibers 203 . The distribution of the fibers in the second bulking zone 230 is such that the concentration of the second bulking fibers 204 is greater at the outer boundary 241 of the second bulking zone 240 than the inner boundary 242 of that zone. Also, as illustrated, it is preferred that the concentration of the second bulking fibers 204 decreases in a gradient along the z-axis from the outer boundary 241 of the second bulking zone 240 to the inner boundary 242 of that zone.
[0020] Still referring to FIG. 2 , the first bulking zone 230 will also contain heat and flame resistant fibers 201 . However, the first bulking zone 230 will contain more of the first bulking fibers 203 than the heat and flame resistant fibers 201 . The heat and flame resistant zone 210 can have some amount of the second bulking fiber 204 ; however, the amount of second bulking fiber 204 in the heat and flame resistant zone 210 is significantly lower than the first bulking fibers 203 . The second bulking zone 240 can also have some amount of the heat and flame resistant fibers 201 ; however, the amount of the heat and flame resistant fibers 201 in the second bulking zone is significantly lower than the first bulking fibers 203 . An advantage of using the two distinct bulking fibers 203 / 204 ( FIG. 2 ) over using a single bulking fiber 102 ( FIG. 1 ), is that for the same respective weights of heat and flame resistant fibers 101 / 201 and voluminous bulking fibers 102 / 202 , a shield material 200 having two types of bulking fibers 203 and 204 will have fewer heat and flame resistant fibers 201 located in the voluminous bulking zone 120 / 220 than a shield material 100 having only one type of bulking fiber 102 .
[0021] Referring now to FIG. 3 , there is shown a diagram of a particular piece of equipment 300 for the process to form the planar unitary heat and flame shield from FIGS. 1 and 2 . A commercially available piece of equipment that has been found satisfactory in this process to form the claimed invention is the “K-12 HIGH-LOFT RANDOM CARD” by Fehrer A G, in Linz, Austria. The heat and flame resistant fibers 101 / 201 and the voluminous bulking fibers 102 / 202 are opened and blended in the appropriate proportions and enter an air chamber 310 . In an embodiment using the binder fibers 105 / 205 , the binder fibers 105 / 205 are also opened and blended with the heat and flame resistant fibers 101 / 201 and the bulking fibers 102 / 202 prior to introduction into the air chamber 310 . In an embodiment where the voluminous bulking fibers 202 contain multiple types of bulking fibers 203 / 204 , those multiple types of bulking fibers 203 / 204 are also opened and blended in the appropriate portions with the other fibers before introduction into the air chamber 310 . The air chamber 310 suspends the blended fibers in air, and delivers the suspended and blended fibers to a roller 320 . The roller 320 rotates and slings the blended fibers towards a collection belt 330 . The spinning rotation of the roller 320 slings the heavier fibers a further distance along the collection belt 330 than it slings the lighter fibers. As a result, the mat of fibers collected on the collection belt 330 will have a greater concentration of the lighter fibers adjacent to the collection belt 330 , and a greater concentration of the heavier fibers further away from the collection belt 330 .
[0022] In the embodiment of the shield 100 illustrated in FIG. 1 , the heat and flame resistant fibers 101 are lighter than the voluminous bulking fibers 102 . Therefore, in the process illustrated in FIG. 3 , the heat and flame resistant fibers 101 collect in greater concentration near the collection belt 330 , and the voluminous bulking fibers 102 collect in greater concentration away from the collection belt 330 . It is this distribution by the equipment 300 that creates the heat and flame resistant zone 110 and the voluminous bulking zone 120 of the planar unitary shield material 100 .
[0023] In the embodiment of the shield 200 illustrated in FIG. 2 , the heat and flame resistant fibers 201 are lighter than the voluminous bulking fibers 202 . Therefore, in the process illustrated in FIG. 3 , the heat and flame resistant fibers 201 collect in greater concentration near the collection belt 330 , and the voluminous bulking fibers 202 collect in greater concentration away from the collection belt 330 . It is this distribution by the equipment 300 that creates the heat and flame resistant zone 210 and the voluminous bulking zone 220 of the planar unitary shield material 200 . Additionally, the first bulking fibers 203 of the voluminous bulking fibers 220 are lighter than the second bulking fibers 204 . Therefore, in the process illustrated in FIG. 3 , the first bulking fibers 203 are collected in greater concentration nearer the collection belt 330 than the second bulking fibers 204 . It is this distribution that creates the first bulking zone 230 and the second bulking zone 240 of the voluminous bulking zone 220 of the planar unitary shield material 200 .
[0024] In one example of the present invention, planar unitary heat and flame resistant shield material was formed from a blend of four fibers including:
1) 4% by weight of a heat and flame resistant fiber being 2 dpf partially oxidized polyacrylonitrile 2) 25% by weight of a first bulking fiber being 6 dpf polyester 3) 41% by weight of a second bulking fiber being 15 dpf polyester, and 4) 30% by weight of a low melt binder fiber being 4 dpf core sheath polyester with a lower melting temperature sheath.
The fibers were opened, blended and formed into a shield material using a K-12 HIGH-LOFT RANDOM CARD” by Fehrer A G. The shield had a weight per square yard of about 16-32 ounces and a thickness in the range of about 12-37 mm. In the resulting shield material, the heat and flame resistant fibers in the heat and flame resistant zone comprised at least 70% of the total fibers in that zone, and the heat and flame resistant fibers in the voluminous bulking zone were less than about 2% of the total fibers in that zone.
[0029] Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. For example, an additional layer of material such as a nonwoven can be added to the outside surface or the inside surface of the present invention for additional purposes. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein. | A heat and fire resistant planar unitary shield formed of heat and flame resistant fibers and voluminous bulking fibers. The shield material has a heat and flame resistant zone with a majority of the heat and flame resistant fibers, and a voluminous bulking zone with a majority of the voluminous bulking fibers. The fibers are distributed through the shield material in an manner that the heat and flame resistant fibers collect closest to the outer surface of the shield with the heat and flame resistant zone, and the voluminous bulking fibers collect closest to the outer surface of the shield material with the voluminous bulking zone. | 3 |
BACKGROUND OF THE INVENTION
[0001] Without limiting the scope of the present invention, its background is described with reference to the production of hydrocarbon fluids through a wellbore traversing an unconsolidated or loosely consolidated formation, as an example.
[0002] It is well known in the subterranean well drilling and completion art that particulate materials such as sand may be produced during the production of hydrocarbons from a well traversing an unconsolidated or loosely consolidated subterranean formation. Numerous problems may occur as a result of the production of such particulate. For example, the particulate cause abrasive wear to components within the well, such as tubing, pumps and valves. In addition, the particulate may partially or fully clog the well creating the need for an expensive workover. Also, if the particulate matter is produced to the surface, it must be removed from the hydrocarbon fluids by processing equipment at the surface.
[0003] One method for preventing the production of such particulate material to the surface is gravel packing the well adjacent to the unconsolidated or loosely consolidated production interval. In a typical gravel pack completion, a sand control screen is lowered into the wellbore on a work string to a position proximate the desired production interval. A fluid slurry including a liquid carrier and a particulate material known as gravel is then pumped down the work string and into the well annulus formed between the sand control screen and the perforated well casing or open hole production zone.
[0004] The liquid carrier either flows into the formation or returns to the surface by flowing through the sand control screen or both. In either case, the gravel is deposited around the sand control screen to form a gravel pack, which is highly permeable to the flow of hydrocarbon fluids but blocks the flow of the particulate carried in the hydrocarbon fluids. As such, gravel packs can successfully prevent the problems associated with the production of particulate materials from the formation.
[0005] It has been found, however, that a complete gravel pack of the desired production interval is difficult to achieve particularly in long or inclined/horizontal production intervals. These incomplete packs are commonly a result of the liquid carrier entering a permeable portion of the production interval causing the gravel to form a sand bridge in the annulus. Thereafter, the sand bridge prevents the slurry from flowing to the remainder of the annulus which, in turn, prevents the placement of sufficient gravel in the remainder of the annulus.
[0006] Prior art devices and methods have been developed which attempt to overcome this sand bridge problem. For example, attempts have been made to use devices having perforated shunt tubes or bypass conduits that extend along the length of the sand control screen to provide an alternate path for the fluid slurry around the sand bridge.
[0007] It has been found, however, that shunt tubes installed on the exterior of sand control screens are susceptible to damage during installation and may fail during a gravel packing operation. In addition, it has been found that on site assembly of a shunt tube system around a sand control screen is difficult and time consuming due to the large number of fluid connections required for typical production intervals. Further, it has been found that the effective screen area available for filtering out particulate from the production fluids is reduced when shunt tubes are installed on the exterior of a sand control screen.
[0008] Therefore a need has arisen for an apparatus and method for gravel packing a production interval traversed by a wellbore that overcomes the problems created by sand bridges. A need has also arisen for such an apparatus that is not susceptible to damage during installation and will not fail during a gravel packing operation. Additionally, a need has arisen for such an apparatus that is cost effective and does not require difficult or time consuming on site assembly. Further, a need has arisen for such an apparatus that does not require a reduction in the effective screen area available for filtering out particulate from the production fluids.
SUMMARY OF THE INVENTION
[0009] The present invention disclosed herein comprises a screen assembly and method for gravel packing a production interval of a wellbore that traverses an unconsolidated or loosely consolidated formation that overcomes the problems created by the development of a sand bridge between a sand control screen and the wellbore. Importantly, the screen assembly of the present invention is not susceptible to damage during installation or failure during the gravel packing operation, is cost effective to manufacture and does not require difficult or time consuming on site assembly. In addition, the screen assembly of the present invention allows for a relatively large effective screen area for filtering out particulate from the production fluids.
[0010] The sand control screen assembly of the present invention comprises a base pipe that has one or more perforated sections and one or more nonperforated sections. A plurality of ribs are circumferentially spaced around and axially extending along the exterior surface of the base pipe. Two of the ribs are positioned within each of the nonperforated sections of the base pipe. A screen wire is wrapped around the plurality of ribs forming a plurality of turns having gaps therebetween. A filler material is disposed within the portions of the gaps that are circumferentially aligned with the nonperforated sections of the base pipe.
[0011] The screen assembly includes one or more slurry passageways each of which are defined by one of the nonperforated section of the base pipe, the two ribs positioned within that nonperforated section of the base pipe and the portion of the wire and the filler material in the gaps that are circumferentially aligned with that nonperforated section of the base pipe. The slurry passageways are used to carry a fluid slurry containing gravel past any sand bridges that may form in the annulus surrounding the screen assembly. The fluid slurry is discharged from the screen assembly via a plurality of manifolds that are in fluid communication with the slurry passageways. The manifolds selectively discharge the fluid slurry to a plurality of levels of the interval through exit ports formed therein when the screen assembly is in an operable position. The exit ports may be either circumferentially aligned with the slurry passageways, circumferentially misaligned with the slurry passageways or both. The fluid communication between the manifolds and the slurry passageways may be established using tubes that extend from the manifolds into each adjacent sections of the slurry passageways.
[0012] In embodiments of the present invention wherein the screen assembly includes more than one section of sand control screen, each including a portion of the slurry passageway, the screen assembly includes a manifold between each of the sand control screen sections. These manifolds provide fluid communication between the portions of the slurry passageways of the adjacent sand control screen sections and deliver the fluid slurry into the interval surrounding the screen assembly.
[0013] In one embodiment of the present invention, the exit ports are created directly through the wire and the filler material in the gaps that are circumferentially aligned with the nonperforated sections of the base pipe instead of in manifolds. In this embodiment, tube segments may be disposed within the slurry passageways at the locations where the exit ports are created to provide support to the screen wire at these locations.
[0014] The method of the present invention includes traversing a formation with the wellbore, positioning a sand control screen assembly having one or more slurry passageways as described above, within the wellbore, injecting a fluid slurry containing gravel through the slurry passageways such that the fluid slurry exits the screen assembly through exit ports in manifolds or through the screen wire at a plurality of levels of the interval and terminating the injecting when the interval is substantially completely packed with the gravel.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the features and advantages of the present invention, reference is now made to the detailed description of the invention along with the accompanying figures in which corresponding numerals in the different figures refer to corresponding parts and in which:
[0016] [0016]FIG. 1 is a schematic illustration of an offshore oil and gas platform operating a sand control screen assembly for gravel packing an interval of a wellbore of the present invention;
[0017] [0017]FIG. 2 is partial cut away view of a sand control screen assembly for gravel packing an interval of a wellbore of the present invention;
[0018] [0018]FIG. 3 is cross sectional view of the sand control screen assembly for gravel packing an interval of a wellbore of FIG. 2 taken along line 3 - 3 ;
[0019] [0019]FIG. 4 is cross sectional view of the sand control screen assembly for gravel packing an interval of a wellbore of FIG. 2 taken along line 4 - 4 ;
[0020] [0020]FIG. 5 is cross sectional view of the sand control screen assembly for gravel packing an interval of a wellbore of FIG. 2 taken along line 5 - 5 ;
[0021] [0021]FIG. 6 is a side view of two adjacent sand control screens of a sand control screen assembly for gravel packing an interval of a wellbore of the present invention;
[0022] [0022]FIG. 7 is side view of a sand control screen assembly for gravel packing an interval of a wellbore of the present invention;
[0023] [0023]FIG. 8 is a cross sectional view of the sand control screen assembly for gravel packing an interval of a wellbore of FIG. 7 taken along line 8 - 8 ; and
[0024] [0024]FIG. 9 is a half sectional view depicting the operation of a sand control screen assembly for gravel packing an interval of a wellbore of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0025] While the making and using of various embodiments of the present invention are discussed in detail below, it should be appreciated that the present invention provides many applicable inventive concepts which can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not delimit the scope of the present invention.
[0026] Referring initially to FIG. 1, a sand control screen assembly for gravel packing an interval of a wellbore operating from an offshore oil and gas platform are schematically illustrated and generally designated 10 . A semi-submersible platform 12 is centered over a submerged oil and gas formation 14 located below sea floor 16 . A subsea conduit 18 extends from deck 20 of platform 12 to wellhead installation 22 including blowout preventers 24 . Platform 12 has a hoisting apparatus 26 and a derrick 28 for raising and lowering pipe strings such as work string 30 .
[0027] A wellbore 32 extends through the various earth strata including formation 14 . A casing 34 is cemented within wellbore 32 by cement 36 . Work string 30 includes various tools for completing the well. On the lower end of work string 30 is a sand control screen assembly 38 for gravel packing an interval of wellbore 32 made up of a plurality of sections of sand control screens 40 , three of which are depicted in FIG. 1. Sand control screen assembly 38 is positioned adjacent to formation 14 between packers 44 , 46 in annular region or interval 48 including perforations 50 . When it is desired to gravel pack annular interval 48 , a fluid slurry including a liquid carrier and a particulate material such as gravel is pumped down work string 30 .
[0028] As explained in more detail below, the fluid slurry will generally be injected into annular interval 48 between screen assembly 38 and wellbore 32 in a known manner such as through a cross-over tool (not pictured) which allows the slurry to travel from the interior of work string 30 to the exterior of work string 30 . Once the fluid slurry is in annular interval 48 , a portion of the gravel in the fluid slurry is deposited in annular interval 48 . Some of the liquid carrier may enter formation 14 through perforation 50 while the remainder of the fluid carrier entering sand control screen assembly 38 . More specifically, sand control screen assembly 38 disallows further migration of the gravel in the fluid slurry but allows the liquid carrier to travel therethrough and up to the surface in a known manner, such as through a wash pipe and into the annulus 52 above packer 44 .
[0029] If a sand bridge forms during the injection of the fluid slurry into annular region 48 , the fluid slurry will be diverted into one or more slurry passageways in sand control screen assembly 38 to bypass this sand bridge. In this case, the fluid slurry will be discharged from sand control screen assembly 38 through exit port at various levels within interval 48 . Again, once in annular interval 48 , the gravel in the fluid slurry is deposited therein. Some of the liquid carrier may enter formation 14 through perforation 50 while the remainder of the fluid carrier enters sand control screen assembly 38 , as described above, and returns to the surface. The operator continues to pump the fluid slurry down work string 30 into annular interval 48 and through the slurry passageways of sand control screen assembly 38 , as necessary, until annular interval 48 surrounding sand control screen assembly 38 is filled with gravel, thereby achieving a complete pack of interval 48 . Alternatively, it should be noted by those skilled in the art, that the fluid slurry may be injected entirely into the slurry passageways of sand control screen assembly 38 without first injecting the fluid slurry directly into annular interval 48 .
[0030] Even though FIG. 1 depicts a vertical well, it should be noted by one skilled in the art that the screen assembly for gravel packing an interval of a wellbore of the present invention is equally well-suited for use in deviated wells, inclined wells or horizontal wells. In addition, it should be apparent to those skilled in the art that the use of directional terms such as above, below, upper, lower, upward, downward and the like are used in relation to the illustrative embodiments as they are depicted in the figures, the upward direction being toward the top of the corresponding figure and the downward direction being toward the bottom of the corresponding figure.
[0031] Also, even though FIG. 1 depicts an offshore operation, it should be noted by one skilled in the art that the screen assembly for gravel packing an interval of a wellbore of the present invention is equally well-suited for use in onshore operations. Further, even though FIG. 1 has been described with regard to a gravel packing operation, it should be noted by one skilled in the art that the screen assembly of the present invention is equally well-suited for fracture operations and frac pack operations wherein a fluid slurry containing propping agents is delivered at a high flow rate and at a pressure above the fracture pressure of formation 14 such that fractures may be formed within formation 14 and held open by the propping agents and such that annular interval 48 is packed with the propping agents or other suitable particulate materials to prevent the production of fines from formation 14 .
[0032] Referring now to FIG. 2, therein is depicted a partial cut away view of a sand control screen assembly for gravel packing an interval of a wellbore of the present invention that is generally designated 60 . Screen assembly 60 has a base pipe 62 that has a plurality of perforated sections and a plurality of nonperforated sections. In the illustrated embodiment and as best seen in FIG. 3, screen assembly 60 has three perforated sections 64 each of which include a plurality of openings 66 . The exact number, size and shape of openings 66 are not critical to the present invention, so long as sufficient area is provided for fluid production and the integrity of base pipe 62 is maintained. Screen assembly 60 also has three nonperforated sections 68 which are positioned at approximately 120 degree intervals from one another.
[0033] Circumferentially distributed around and axially extending along the outer surface of base pipe 62 is a plurality of ribs 70 . In the illustrated embodiment, ribs 70 are generally symmetrically distributed about the axis of base pipe 62 . Preferably, ribs 70 have a generally triangular cross section wherein the base portion of ribs 70 that contacts base pipe 62 has an arcuate shape that substantially matches the curvature of base pipe 62 . Alternatively, the base portion of ribs 70 may be shaped such that ribs 70 contact base pipe 62 only proximate the apexes of the base portion of ribs 70 . In either case, once screen assembly 60 is fully assembled, the base portion of ribs 70 should securely contact base pipe 62 and provide the necessary fluid seal at the locations where the base portion of ribs 70 contact base pipe 62 . Importantly, two of the ribs 70 are positioned against each of the nonperforated sections 68 of base pipe 62 . Specifically, ribs 72 , 74 , ribs 76 , 78 and ribs 80 , 82 are respectively positioned against nonperforated sections 68 .
[0034] Even though ribs 70 have been described as having a generally triangular cross section, it should be understood by one skilled in the art that ribs 70 may alternatively have other cross sectional geometries including, but not limited to, rectangular and circular cross sections so long as a proper seal between the ribs and the base pipe is established. Additionally, it should be understood by one skilled in the art that the exact number of ribs 70 will be dependent upon factors such as the diameter of base pipe 62 , the width of nonperforated sections 68 , as well as other design characteristics that are well known in the art.
[0035] Wrapped around and welded to ribs 70 is a screen wire 84 . Screen wire 84 forms a plurality of turns, such as turn 86 , turn 88 and turn 90 . Between each of the turns is a void or gap through which formation fluids flow such as gap 92 between turns 86 , 88 and gap 94 between turns 88 , 90 . The number of turns and the gap between the turns are determined based upon factors such as the characteristics of the formation from which fluid is being produced and the size of the gravel to be used during the gravel packing operation. As illustrated, the gaps in the sections of screen wire 84 that are circumferentially aligned with nonperforated sections 68 of base pipe 62 are sealed with a filler material 96 such as an epoxy resin. Filler material 96 is selectively placed in the gaps between the turns of screen wire 84 such that fluid sealed slurry passageways 98 are created between respective nonperforated sections 68 , ribs 70 and sealed sections 100 of screen wire 84 .
[0036] Together, ribs 70 and screen wire 84 may form a sand control screen jacket that is attached to base pipe 62 by welding or other suitable technique forming each screen section of screen assembly 60 . Alternatively, screen wire 84 may be wrapped around and welded to ribs 70 in place against base pipe 62 . It should be noted by those skilled in the art that even though FIG. 2 has depicted a wire wrapped screen, other types of filter media could alternatively be placed over ribs 70 without departing from the principles of the present invention including, but not limited to, a fluid-porous, particulate restricting, sintered metal material such as a plurality of layers of a wire mesh that are sintered together to form a porous sintered wire mesh screen that is seam welded or spiral welded over ribs 70 .
[0037] Positioned at selected intervals, such as every five to ten feet, along each screen section of sand control screen assembly 60 is a manifold 102 . Manifold 102 is in fluid communication with slurry passageways 98 via tubes 104 which extend partially into slurry passageways 98 , as best seen in FIG. 4. In the illustrated embodiment, tubes 104 are welded within slurry passageways 98 . Tubes 104 deliver the fluid slurry carried in slurry passageways 98 into manifold 102 . A portion of the fluid slurry in manifold 102 will enter the annular interval surrounding screen assembly 60 via exit ports 106 . The remainder of the fluid slurry passes through annular area 108 of manifold 102 and enters the next section of slurry passageways 98 , as best seen in FIG. 5. This process continues through the various levels of screen assembly 60 along the entire length of the interval to be gravel packed such that a complete gravel pack of the interval can be achieved.
[0038] In the illustrated embodiment, exit ports 106 of manifold 102 are not circumferentially aligned with slurry passageways 98 of screen assembly 60 . This configuration helps to minimize liquid leak off after the area adjacent to a particular manifold has been packed with the gravel. Specifically, even after an area surrounding one of the manifolds has been packed with the gravel, it has been found that liquid from the fluid slurry may nonetheless leak off into this porous region causing not only a reduction in the velocity of the fluid slurry in slurry passageways 98 , but also, an increase in the effective density of particles in the fluid slurry, each of which is a hindrance to particle transport to locations further along screen assembly 60 . Positioning exit ports 106 out of phase with slurry passageways 98 reduces the liquid leak off by increasing the pressure required to push the liquid through the porous matrix and reduces the velocity of the liquid near exit ports 106 , thereby reducing the rate of liquid leak off. This rate of liquid leak off is further reduced by using a liquid in the fluid slurry that is thixotropic such that its viscosity increases with reduced velocity through the porous matrix.
[0039] Even though FIG. 2 has depicted exit ports 106 as being circular, it should be understood by those skilled in the art that exit ports 106 could alternatively have other shapes without departing from the principles of the present invention, those shapes being considered within the scope of the present invention. Also, it should be noted by those skilled in the art that even though FIGS. 2 - 4 have depicted three slurry passageways 98 at 120 degree intervals around screen assembly 60 , other numbers of slurry passageways, either greater or fewer, and other intervals between such slurry passageways may be used without departing from the principles of the present invention and are considered within the scope of the present invention. Likewise, even though FIGS. 2 and 5 have depicted three exit ports 160 at 120 degree intervals around manifold 102 , other numbers of exit port, either greater or fewer, and other intervals between such exit ports may be used without departing from the principles of the present invention and are considered within the scope of the present invention.
[0040] Referring now to FIG. 6, therein is depicted a screen assembly for gravel packing an interval of a wellbore at the point where two sand control screens are joined together, that is generally designated 120 . As illustrated, screen assembly 120 includes sand control screen 122 and sand control screen 124 each of which have the substantially identical construction as that described above with reference with reference to FIGS. 2 - 5 . Screens 122 , 124 are coupled together in a known manner such as via a threaded coupling (not pictured). Between screens 122 , 124 , screen assembly 120 includes a tube and manifold system 126 . Tube and manifold system 126 includes three tubes 128 , only two of which are pictured, that deliver the fluid slurry from slurry passageways 98 of screen 122 to manifold 130 . A portion of the fluid slurry in manifold 130 will enter the annular interval surrounding screen assembly 120 via three exit ports 132 , only one of which is shown. The remainder of the fluid slurry enters three tubes 134 , only two of which are pictured, and is delivered to slurry passageways 98 of screen 124 .
[0041] Even though FIG. 6 depicts tubes 128 that deliver the fluid slurry to manifold 130 as being circumferentially aligned with tubes 134 that transport the fluid slurry from manifold 130 , it is likely that tubes 128 , 134 will not be circumferentially aligned as the adjoining sections of tube and manifold system 126 are threadably coupled when screen sections 122 , 124 of screen assembly 120 are threaded together. Accordingly, it is likely that tubes 128 and tubes 134 on opposite sides of manifold 130 will not be circumferentially aligned with one another.
[0042] As should be apparent to those skilled in the art, even when tubes 128 and tubes 134 are positioned with a circumferential phase shift relative to one another, this does not affect the operation of the present invention as manifold 130 has a substantially annular region, such as annular region 108 depicted in FIG. 5, through which the fluid slurry travels allowing for such misalignment. As such, the mating of adjoining sections of the screen assembly for gravel packing an interval of a wellbore of the present invention is substantially similar to mating typical joints of pipe to form a pipe string requiring no special coupling tools or techniques.
[0043] Referring now to FIGS. 7 and 8, therein is depicted another embodiment of a screen assembly for gravel packing an interval of a wellbore that is generally designated 140 . Screen assembly 140 includes a base pipe 62 that has three perforated sections 64 having openings 66 and three nonperforated sections 68 . Circumferentially distributed around and axially extending along the outer surface of base pipe 62 is a plurality of ribs 70 having a generally triangular cross section. Importantly, two of the ribs 70 are positioned against each of the nonperforated sections 68 of screen assembly 60 . Specifically, ribs 72 , 74 , ribs 76 , 78 and ribs 80 , 82 are respectively positioned against nonperforated sections 68 . Wrapped around and welded to ribs 70 is a screen wire 84 . Screen wire 84 forms a plurality of turns, such as turn 86 , turn 88 and turn 90 . Between each of the turns is a gap through which formation fluids flow such as gap 92 between turns 86 , 88 and gap 94 between turns 88 , 90 . The gaps in the sections of screen wire 84 that are circumferentially aligned with nonperforated sections 68 of base pipe 62 are sealed with a filler material 96 . Filler material 96 is selectively placed in the gaps between the turns of screen wire 84 such that fluid sealed slurry passageways 98 are created between respective nonperforated sections 68 , ribs 70 and sealed sections 100 of screen wire 84 .
[0044] Positioned at selected intervals, such as every five to ten feet, along each screen section of sand control screen assembly 140 and within slurry passageways 98 are tube segments 142 , as best seen in FIG. 8. In the illustrated embodiment, tube segments 142 are welded within slurry passageways 98 . Tube segments 142 , which may be several inches to a foot long, are used to support screen wire 84 such that exit ports 144 may be drilled therethrough. A portion of the fluid slurry traveling through tube segments 142 will enter the annular interval surrounding screen assembly 140 via exit ports 144 . The remainder of the fluid slurry passes through tube segments 142 and enters the next section of slurry passageways 98 . This process continues through the various levels of screen assembly 140 along the entire length of the interval to be gravel packed such that a complete gravel pack of the interval can be achieved.
[0045] Referring now to FIG. 9, a typical completion process using screen assembly 60 for gravel packing an interval of a wellbore of the present invention will be described. First, screen assembly 60 is positioned within wellbore 32 proximate formation 14 and interval 48 adjacent to formation 14 is isolated. Packer 44 seals the upper end of annular interval 48 and packer 46 seals the lower end of annular interval 48 . Cross-over assembly 150 is located adjacent to screen assembly 60 , traversing packer 44 with portions of cross-over assembly 150 on either side of packer 44 . When the gravel packing operation commences, the objective is to uniformly and completely fill interval 48 with gravel. To help achieve this result, wash pipe 154 is disposed within screen assembly 60 . Wash pipe 154 extends into cross-over assembly 150 such that return fluid passing through screen assembly 60 , indicated by arrows 156 , may travel through wash pipe 154 , as indicated by arrow 158 , and into annulus 52 , as indicted by arrow 160 , for return to the surface.
[0046] The fluid slurry containing gravel is pumped down work string 30 into cross-over assembly 150 along the path indicated by arrows 162 . The fluid slurry containing gravel exits cross-over assembly 150 through cross-over ports 164 and is discharged into annular interval 48 as indicated by arrows 166 . This is the primary path as the fluid slurry seeks the path of least resistance. Under ideal conditions, the fluid slurry travels throughout the entire interval 48 until interval 48 is completely packed with gravel. If, however, a sand bridge forms in annular interval 48 before the gravel packing operation is complete, the fluid slurry containing gravel will enter slurry passageways 98 of screen assembly 60 to bypass the sand bridge as indicated by arrow 168 . The fluid slurry then travels within slurry passageways 98 with some of the fluid slurry exiting screen assembly 60 at each of the manifolds 102 through exit ports 106 , as indicated by arrows 170 .
[0047] As the fluid slurry containing gravel enters annular interval 48 , the gravel drops out of the slurry and builds up from formation 14 , filling perforations 50 and annular interval 48 around screen assembly 60 forming the gravel pack. Some of the carrier fluid in the slurry may leak off through perforations 50 into formation 14 while the remainder of the carrier fluid passes through screen assembly 60 , as indicated by arrows 156 , that is sized to prevent gravel from flowing therethrough. The fluid flowing back through screen assembly 60 , as explained above, follows the paths indicated by arrows 158 , 160 back to the surface.
[0048] In operation, the screen assembly for gravel packing an interval of a wellbore of the present invention is used to distribute the fluid slurry to various locations within the interval to be gravel packed by injecting the fluid slurry into the slurry passageways of the screen assembly when sand bridge formation occurs. The fluid slurry exits through the various exit ports in the manifolds along the length of the screen assembly into the annulus between the screen assembly and the wellbore which may be cased or uncased. Once in this annulus, a portion of the gravel in the fluid slurry is deposited around the screen assembly in the annulus such that the gravel migrates both circumferentially and axially from the exit ports. This process progresses along the entire length of the screen assembly such that the annular area becomes completely packed with the gravel. Once the annulus is completely packed with gravel, the gravel pack operation may cease.
[0049] Alternatively, it should be noted by those skilled in the art that instead of first injecting the fluid slurry directly into annular interval 48 until a sand bridge forms, the fluid slurry may initially be injected directly into the slurry passageways of the screen assembly for gravel packing an interval of a wellbore of the present invention. In either embodiment, once the gravel pack is completed and the well is brought on line, formation fluids that are produced into the gravel packed interval must travel through the gravel pack in the annulus prior to entering the sand control screen assembly. As such, the screen assembly for gravel packing an interval of a wellbore of the present invention allows for a complete gravel pack of an interval so that particulate materials in the formation fluid are filtered out.
[0050] While this invention has been described with reference to illustrative embodiments, this description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments. | A screen assembly ( 60 ) comprises a base pipe ( 62 ) having perforated and nonperforated sections ( 66, 68 ), ribs ( 70 ) circumferentially spaced therearound and a filter medium ( 84 ) positioned around the ribs ( 70 ) having voids ( 92, 94 ) therethrough. The screen assembly ( 60 ) includes a slurry passageway ( 98 ) defined by the nonperforated section ( 68 ) of the base pipe ( 62 ), two of the ribs ( 70 ) and the portion ( 100 ) of the filter medium ( 84 ) that is circumferentially aligned with the nonperforated section ( 68 ). This portion ( 100 ) of the filter medium ( 84 ) has a filler material ( 96 ) disposed within the voids ( 92, 94 ) to create a fluid tight seal for a fluid slurry. The fluid slurry is discharged from the screen assembly ( 60 ) to a plurality of levels of the interval through exit ports ( 106 ) in a plurality of manifolds ( 102 ) when the screen assembly ( 60 ) is in an operable position. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to a foldable frame for creating a scoop, and more particularly to a scoop which is ideal for picking up animal fecal waste. Further, the present invention relates to a scoop which is inexpensive and disposable. The foldable frame may be easy stored and/or transported in a flat configuration and subsequently folded into a functional scoop configuration prior to use.
[0002] A large number of family households have cats, dogs and/or other pets. Despite the joy these families receive from their pet(s), they are often left with the chore of cleaning up the waste from the pet. If the pet created the waste in a public area, such as a park, it is common that city laws or ordinances require the proper disposal of the animal's waste. If the animal created the waste on the owner's property, failure to clean up after the pet usually results in a diminished enjoyment of the owner's property.
[0003] People generally agree that cleaning up after a pet is not a pleasant experience. To accomplish this, people have implemented numerous devices, perhaps the most common of which is the standard shovel. A problem with using a standard shovel to clean up after a pet is that most people return the shovel to their garage or backyard with some remnants of the animal waste on the shovel. This practice may lead to an undesirable odor around the house as well as the creation of unhealthy living conditions. Further, if the owner decides to take the pet on a walk around the block, it is unpractical for the pet owner to bring a standard shovel along with a pet. Even further, the use of a standard shovel to clean up animal waste still leads to the problem of scooping the waste into the shovel without the shovel merely pushing the waste forward.
[0004] Alternatively, people often resort to cleaning up after the pet with a plastic bag. This practice, however, is also undesirable. The use of a plastic bag requires the owner to come into close contact with the animal's waste. Again, this may result in odor or disease passing from the waste to the human.
[0005] Further devices for picking up and disposing of an animal's waste include the use of plastic bags attached to scoops or thongs for picking up waste. However, these and other devices and methods are not convenient to use, fail to protect users from contamination by the waste, or have other disadvantages or drawbacks.
[0006] A need, therefore, exists for a foldable frame which coverts into a scoop which overcomes the foregoing problems and disadvantages. Further, a need exists for an improved animal waste scoop which may be stored in a flat configuration and easily folded into a functional configuration. A still further need exists for a scoop which is disposable.
SUMMARY OF THE INVENTION
[0007] The present invention is directed toward a scoop for picking up and disposing of animal waste. More specifically, the scoop may be easy stored and or transported in a flat configuration and folded into the functional scoop prior to use. Further, the scoop may be made from a single substantially flat structure.
[0008] The scoop may be constructed from a semi-rigid material, such as, for example, cardboard, heavy duty paper or the like. The scoop may be inexpensively manufactured so as to allow disposal thereof after a single use. In a preferred embodiment, the scoop may be constructed of a biodegradable material.
[0009] Ideally, the scoop may be transported in a flat configuration and may be generally likewise stored in the flat configuration prior to use. Because the scoop may be transported and/or stored in a flat configuration, the scoop may be suitable for sale in a vending machine, for example, at a rest area, in a park or at a pet store.
[0010] The scoop may be easily folded into the functional configuration by almost anyone in under one minute. Further, to aid the user in the folding of the scoop, folding directions may be printed directly on the scoop. As a result, the user may not have to worry about loosing the folding directions. The folding of the scoop from the flat configuration into the functional configuration may be aided by numerous score lines in the semi-rigid material. The score lines allow the folding of the material without compromising the durability of the functional scoop.
[0011] A removable front section of the scoop may be separated from the scoop and aid the user into pushing the waste into the main scoop opening. As a result, the user may easily move the waste into the scoop without directly contacting the waste. After the waste is in the scoop, the removable front section, the waste and the scoop may then be disposed of in the proper manner.
[0012] The rear section of the functional scoop has a durable handle capable of supporting the scoop filled with waste. In addition, the handle has a hole for hanging the scoop in the flat or functional configuration. Still further, hole in the handle may be used to secure a plastic bag into the handle.
[0013] The scoop is suitable for use not only outside in, for example, a yard, sidewalk or park, but also may be used indoors in, for example, a litter box. Further, the scoop may be made of a material suitable for scooping up liquids in, for example, a litter box. More specifically, the scoop may be treated with a chemical which resists the absorption of liquids.
[0014] To this end, in an embodiment, a novel device is provided. The device is a foldable frame for forming a scoop. The foldable frame has a first section having a first edge, a second edge, a front edge and a back edge. The foldable frame also has a second section attached to the front edge of the first section wherein the second section is separated from the first section by a score line and wherein the second section has a top surface. Still further, the foldable frame has a main handle section attached to the back edge of the first section and a first side panel and a second side panel attached to the second section. Finally, the frame has a removable section attached to the second section wherein the removable section is separated from the second section by a score line and wherein the removable section is completely removed from the second section and is used to scoop material onto the top surface of the second section.
[0015] In an embodiment, the foldable frame has an opening in the main handle section.
[0016] In an embodiment, the foldable frame has an opening in the first section.
[0017] In yet another embodiment of the present invention, the foldable frame is made from a biodegradable material.
[0018] In still another embodiment of the present invention, the foldable frame has a score line separating the handle from the back edge of the first section.
[0019] In an embodiment, the foldable frame has been sprayed with a fragrance.
[0020] In an embodiment, the foldable frame has an adhesive strip for securing the foldable frame.
[0021] In still another embodiment, the first section of the foldable frame is rotated with respect to the second section.
[0022] In another embodiment, the first side panel of the foldable frame rotates from a substantially planer configuration with the second section to a substantially perpendicular configuration with the second section.
[0023] In yet another embodiment of the present invention, the second side panel rotates from a substantially planer configuration with the second section to a substantially perpendicular configuration with the second section.
[0024] In an embodiment, the first section rotates from a substantially planer configuration with the second section to a substantially perpendicular configuration with the second section.
[0025] In an embodiment, the second section is substantially square is shape.
[0026] In yet another embodiment, the foldable frame is substantially planar.
[0027] In still another embodiment, directions for folding the foldable frame are printed directly on the foldable frame.
[0028] In an embodiment, the frame is resistant to the absorption of liquids.
[0029] In another embodiment, the main handle section of the foldable frame has a length between three and eight inches.
[0030] In an embodiment, the removable section has a smaller surface area than the second section.
[0031] In yet another embodiment, the second section has a larger surface area than the first section.
[0032] In yet another embodiment, the main handle section has a first subpanel and a second subpanel wherein the first subpanel and second subpanel are separated from the main handle section by a first score line and a second score line; respectively.
[0033] Finally, in another embodiment, the main handle section has a first subpanel and a second subpanel and wherein the first subpanel and second subpanel are separated from the main handle section by score lines and further, wherein the first subpanel and second subpanel rotate from a position substantially planar with the main handle section to a position substantially perpendicular to the main handle section.
[0034] It is, therefore, an advantage of the present invention to provide a novel scoop device.
[0035] A further advantage of the present invention is to provide a novel scoop device which may be transported and/or stored in a flat configuration prior to use.
[0036] Yet another advantage of the present invention is to provide a novel scoop device which is economical to produce and, therefore, may be used once and then discarded.
[0037] An advantage of the present invention is to produce a scoop which is light-weight and small enough to be carried in, for example, a pocket or purse prior to use. The scoop may be carried easily in the folded configuration, in the flat configuration, or in a non-functional folded configuration.
[0038] A still further advantage of the present invention is to provide a scoop which may be dispensed in coin operated machines or the like.
[0039] Yet another advantage of the present invention is to provide a scoop which has a fragrance or fights unpleasant odors.
[0040] Another advantage of the present invention is to provide a foldable frame which converts into a functional scoop by the use of score lines.
[0041] A still further advantage of the present invention is to provide a foldable frame, which converts into a functional scoop, that has folding directions printed on the foldable frame.
[0042] For a more complete understanding of the above listed features and advantages of the scoop, reference should be made to the following detailed description of the preferred embodiments and to the accompanying drawings. Further, additional features and advantages of the present invention are described in, and will be apparent from, the detailed description of the preferred embodiments and from the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 illustrates a side perspective view of the scoop in a folded configuration.
[0044] FIG. 2 illustrates a top flat view of the a foldable frame in a flat configuration.
[0045] FIG. 3 illustrates a side perspective view of a partially folded scoop of the present invention.
[0046] FIG. 4 illustrates a side perspective view of a partially folded scoop of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] The present invention generally provides a foldable frame for creating a scoop. The foldable frame for creating a scoop may be constructed from a semi-rigid material, such as, for example, cardboard, which may be both durable and foldable. The scoop may be used once and discarded or used for as long as the person desires. The scoop further has a removable section which may aid the user in the picking up of, for example, animal fecal waste.
[0048] Referring to the drawing wherein like numerals refer to like parts, FIG. 1 illustrates a scoop 1 for picking up waste, for example, animal fecal waste. The scoop 1 has an opening 20 which receives the waste. The scoop 1 may be suitable for use outside in, for example, a park or backyard, or may be used indoors in, for example, a litter box. The scoop 1 is converted from a foldable frame 2 (as illustrated in FIG. 2 ). In the preferred embodiment, the scoop 1 may be made from cardboard, however, the scoop 1 may be made from, for example, plastic, metal, wood, heavy paper or any other suitable material. The foldable frame 2 may be a single sheet which may be semi-rigid, yet still has flexibility and the capacity to be scored and folded.
[0049] The foldable frame 2 is preferably light weight and, as such, suitable for carrying on walks. The foldable frame 2 or the functional scoop 1 may be small and may fit in most purses, backpacks or other common carrying devices. If the user has limited space in which to carry the scoop 1 while on, for example, a walk, the foldable frame 2 may be transported compactly in a non-functional folded configuration and later converted into the functional scoop configuration.
[0050] In production of the foldable frame 2 , a fragrance or odor reducing chemical may be added to reduce the unwanted odor of, for example, the animal waste. Alternatively, a fragrance or odor reducing chemical may be added to the foldable frame 2 or functional scoop 1 after production. In addition, the invention may have folding directions 80 printed directly on the foldable frame 1 (As illustrated in FIG. 3 ). The folding directions 80 may be, for example, written directions and/or a diagram(s). Printing the folding directions 80 directly on the foldable frame 2 may eliminate the problem of loosing the folding directions. Further, it may allow the user to give the foldable frame 2 to another person without the need to provide the person with a folding manual.
[0051] Referring now to FIGS. 2-4 , while in the substantially flat configuration ( FIG. 2 ), the foldable flame 2 has a top 3 , a bottom 4 , a first side 5 , a second side 6 , a front 7 and a back 8 . As visible in FIG. 2 , the length of the foldable frame 2 may be greater than the width of the foldable frame 2 . The foldable frame 2 may be folded into the second configuration, as illustrated in FIG. 1 .
[0052] The foldable frame 2 has a plurality of score lines which enable the numerous sections of the foldable flame 2 to be rotated into the functional second configuration. More specifically, the foldable flame 2 has a first section 11 which may be folded upward approximately ninety degrees toward the top 3 of the foldable frame 2 via a single score line 44 which separates the first section 11 from a second section 12 . After the first section 11 has been rotated upward toward the top 3 of the foldable frame 2 and is in the upright position, at least a pair of symmetrical side supports 10 may be rotated forward toward the front 7 of the foldable frame 2 around a first pair of symmetrical score lines 40 .
[0053] Extending from the second section 12 , toward the first side 5 and the second side 6 of the foldable frame 2 ; respectively, may be a pair of symmetrical side panels 15 . The symmetrical side panels 15 may be located closer to the front 7 of the foldable frame 2 than the side supports 10 . The side panels 15 may be rotated approximately ninety degrees upward via a second pair of symmetrical score lines 60 . After being rotated upward toward the top 3 of the foldable frame 2 , the side panels 15 may lay flat against the side supports 10 which have previously been rotated toward the front 7 of the foldable frame 2 . A third pair of symmetrical score lines 43 and fourth pair of symmetrical score lines 41 may then allow a pair of symmetrical interior panels 14 to be folded over the side supports 10 and substantially cover the side supports 10 . More specifically, the interior side panels 14 may rotate approximately one hundred and eighty degrees with respect to the side panels 15 .
[0054] A pair of tabs 17 on the outermost portion of the interior panels 14 may then be secured into a pair of symmetrical tab receivers 16 located within the second section 12 . More specifically, the tab receivers 16 may be located within the second section 12 , near the first side 5 and second side 6 of the foldable frame 2 . The tabs 17 may be secured into the pair of tab receivers 16 by, for example, friction. After the scoop 1 is properly folded and the tabs 17 are properly secured into the tab receivers 16 , the side supports 10 , the side panels 15 and the interior panels 14 align in a substantially parallel position to each other. The use of the tabs 17 and tab receivers 16 of the scoop 1 allow the securing of the scoop 1 into the functional configuration without the need for an adhesive or other securing devices. Preferably, the tab receivers 16 have the approximately the same, or a slightly larger, length than the tabs 17 . Further, the tabs 17 may be removed from the tab receivers 16 if the user wishes to change the scoop 1 from the functional configuration of FIG. 1 into the flat configuration of FIG. 2 for the purpose of, for example, storage.
[0055] While the tabs 17 are inserted into the tab receivers 16 , the interior panels 14 act as the sides of the scoop 1 and help prevent the waste from falling out of the scoop 1 . In the preferred embodiment the tabs 17 allow the foldable frame 2 to be secured into the functional scoop 1 configuration without the need for an adhesive strip 77 or other securing device, such as, a wire. However, in alternative embodiments, an adhesive strip 77 or other securing device may be implemented.
[0056] The scoop 1 may also have a handle 62 having a main handle section 18 which may be folded backward from the first section 11 at a back score line 50 . The back score line 50 may be substantially parallel to the single score line 44 while the scoop 1 is in either the flat or folded configurations. The main handle section 18 may have a first side panel 21 and a second side panel 22 . The first side panel 21 and the second side panel 22 may each be attached to the main handle section 18 by a pair of symmetrical score lines 45 . The main handle section 18 may have an opening 19 which may, for example, allow the scoop 1 to be hung from, for example, a hook in either the substantially flat or folded configurations. Alternatively, the opening 19 may be used to secure a plastic bag (not shown) into the scoop 1 .
[0057] The first side panel 21 of the handle 62 may have an opening 61 and a wing 23 . The wing 23 may be located further away from the main handle section 18 than the first side panel 21 while the scoop 1 is in the substantially flat configuration. The wing 23 may be rotated downward approximately ninety degrees with respect to the first side panel 21 via a score line 46 . A section of the score line 46 , specifically the section in which the opening 61 may be present, completely lacks any connection between the first side panel 21 and the wing 23 .
[0058] The second side panel 22 of the handle 62 may have a wing section 24 attached thereto via a score line 64 . The score line 64 may allow the wing section 24 to rotate downward approximately ninety degrees with respect to the second side panel 22 . The wing section 24 of the second panel 22 may have a first tab 25 and a second tab 26 . The first tab 25 may be located further away from the main handle section 18 than the wing 24 while the scoop 1 is in the substantially flat configuration. The first tab 25 may be separated from the wing section 24 by a score line 51 . More specifically, the score line 51 may allow the first tab 25 to rotate downward approximately ninety degrees with respect to the wing section 24 .
[0059] The second tab 26 of the wing section 24 may be located closer to the front 7 of the scoop 1 then the wing section 24 while the scoop 1 is in the substantially flat configuration. A substantially rectangular slot 29 may be present between the wing section 24 and the second tab 26 . Preferably, the long sides of the rectangular slot 29 are substantially parallel to the long sides of the second tab 26 .
[0060] The second tab 26 may be attached to the wing section 24 by a pair of substantially similar connectors 70 . More specifically, the rectangular slot 29 may be located between the substantially similar connectors 70 .
[0061] To fold the handle 62 into a functional configuration, the wing 23 may be folded approximately ninety degrees downward with respect to the first side panel 21 . The first side panel 21 may be itself then rotated approximately ninety degrees downward with respect to the main handle section 18 .
[0062] The first tab 25 of the wing section 24 may be rotated downward approximately ninety degrees with respect to the wing section 24 along the score line 51 . Following this, the wing section 24 may be rotated approximately ninety degrees downward with respect to the second side panel 22 along the score line 64 . Next, the second side panel 22 may be rotated downward approximately ninety degrees with respect to the main handle section 18 along score line 45 . Upon rotating the second side panel 22 around the score line 45 , the first tab 25 of the wing section 24 will substantially align with the opening 61 . The first tab 25 may then be inserted into the opening 61 and secured by, for example, friction. While the first tab 25 is inside of the opening 61 , the first tab 25 will be substantially obscured from view by the first side panel 21 .
[0063] To finally place the scoop 1 into the functional configuration, the second tab 26 of the wing section 24 may be inserted into an opening 27 within the first section 11 . To properly secure the second tab 26 of the wing section 24 within the opening 27 of the first section 11 , the opening 27 of the first section 11 may be divided by a center tab 28 which locks into the rectangular slot 29 .
[0064] While in the functional configuration, the handle 62 acts as a sturdy means to support and carry the scoop 1 , either empty or filled with waste material. The handle 62 of the scoop 1 is preferable between three and eight inches long to comfortably accommodate the size of an average human hand; however the length of the handle 62 may vary depending on what purpose a particular scoop 1 is constructed for or may vary depending on the size of larger or smaller users.
[0065] The front 7 of the scoop 1 has a removable section 13 attached to the second section 12 by a tear line 75 . When the user pulls on the removable section 13 of the scoop 1 , the force along the tear line 75 causes the tear line 75 to break and completely separate the removable section 13 from the second section 12 . The user may then scoop up waste, for example, animal fecal waste, by using the removable section 13 to push the waste into the opening 20 of the scoop 1 . Utilizing the removable section 13 to push the waste into the opening 20 of the scoop 1 may allow the user to avoid touching the waste with the user's own hand. The user may then discard the removable section 13 , the waste and the scoop 1 . Alternatively, the user may use the functional scoop 1 without removing the removable section 13 from the second section 12 . Still further, the user may use the functional scoop 1 to scoop up waste after removing the removable section 13 from the second section 12 , but without utilizing the removable section 13 to push the waste into the scoop 1 .
[0066] Although steps for folding the foldable frame 2 into the functional scoop 1 are described above, it should be understood that other folding steps or other sequences of the same steps may be implemented to accomplish the same or a similar functional scoop. For example, the user may elect to fold the sections of the handle prior to the folding of the first section 11 with respect to the second section 12 .
[0067] Although embodiments of the present invention are shown and described therein, it should be understood that various changes and modifications to the presently preferred embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. It is, therefore, intended that such changes and modifications be covered by the appended claims. | A foldable hand held scoop which is particularly suitable for picking up animal fecal waste. The scoop is formed from a substantially flat semi-rigid material, such as, for example, cardboard which may be easily folded into a functional configuration by utilizing score lines. In the flat configuration, the scoop may be easily transported and/or stored. The scoop has a bottom panel, a rear panel, two side panels, a handle and an opening section. Further, the scoop has a removable section that aids the user in scooping up the waste into the opening section of the scoop. The scoop may be inexpensive to manufacture and, therefore, suitable for disposal after one or few uses. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention generally relates to luminaires and particularly to luminaires intended for ceiling mounting in either recessed or surface-mounted applications for “washing” an adjacent wall with light as well as other applications.
2. Description of the Prior Art
Luminaires intended for directing light onto vertical surfaces such as walls often fail to provide a visually smooth distribution of light on the vertical surface intended to be illuminated. Such luminaires, generally referred to as “wall wash” luminaires, are typically mounted in a ceiling in proximity to the vertical surface that is to be illuminated. In providing the goal of a smooth distribution of light on a vertical surface of an adjacent wall, it is intended that visible striations or noticeably defined changes in brightness on the vertical surface be minimized or eliminated. Since the accomplishment of a smooth illumination gradient on such a vertical surface is a goal rather than a realistic expectation, it is at least intended in the art to provide an illuminance on said surface having gradations that are sufficiently gradual so as to reduce the affects of variations in brightness such as can take the form of bright or dark lines, bands, scallops and the like such as can be visually distracting. Wall wash luminaires universally employ reflective surfaces configured not only to direct light from lamping onto an adjacent vertical surface but also to smooth the light pattern on said surface. A judicious choice of reflective material as is usual in the prior art, typically diffuse or semi-specular in nature, has previously been considered desirable for smoothing of a light pattern on a vertical surface albeit at the cost of efficiency loss when considering the lumens delivered to the vertical surface by lamping of a particular power level. Diffuser lenses have also been used for similar purposes and with similar results including losses. Luminaires configured with “small apertures”, that is, small in the dimension perpendicular to the “longitudinal” dimension of the luminaire, particularly suffer from efficiency losses when reflectors employed in such luminaires are formed of diffuse or semi-specular reflective material. Luminaires with square apertures as well as other shapes can also exhibit such losses. Further, the differences in brightness between the lamping as compared to lamp “images” in the reflected material produce further difficulties in providing the quality of illumination on a vertical surface that is desired in the art when light from the lamp and from the reflector are both incident on the wall. The use of highly reflective and highly specular reflective material in such luminaires increases the efficiency of light directed onto the vertical surface, and thereby illumination levels realized on the vertical surface, and also greatly reduces differences between the brightness of light illuminating the wall directly from lamping as opposed to the brightness of light reflected from reflectors used in such luminaires. However, utilization of highly specular reflective material in such luminaires provides no panacea in intended results due to the fact that the behavior of highly specular materials in optical environments are extremely sensitive to design errors as well as manufacturing and assembly tolerances. Accordingly, the use of highly specular reflective materials as reflectors in small aperture luminaires as well as other luminaires does not necessarily produce the desired visual appearance of illumination washing a vertical surface or wall.
Wall wash luminaires mountable in ceilings of varying description have previously been provided in a multitude of configurations including downlighting luminaires having circular apertures such as are disclosed by Ling in U.S. Pat. No. 5,535,110 and Leadford in U.S. Pat. No. 5,800,050. Ng et al, in U.S. Pat. No. 6,350,047, and many others, also provide wall wash luminaires intended to be mounted in recessed applications in ceilings whereby at least a portion of that light generated within the luminaire is directed onto at least portions of a wall adjacent to the location wherein the luminaire is mounted within a ceiling. In luminaires of the kind just noted, lamping typically mounted in a vertical orientation is utilized and is generally not tubular fluorescent lighting of a length generally greater than approximately six to ten inches. Wall Wash luminaires employing elongated tubular fluorescent lamping such as T12, T8 and even T5 lamping presently exist as can be appreciated by reference to U.S. Pat. No. 4,564,888 to Lewin et al which discloses a substantially elongated luminaire configured with an elongated reflector for directing light onto a wall from a substantially elongated and generally rectangular aperture. Crane, in U.S. Pat. No. 5,146,393 also discloses a luminaire intended to wash an adjacent wall with light from a location recessed within a ceiling adjacent to the wall. While the apertures of the Lewin et al and Crane luminaires are not necessarily of the “small aperture” kind, the apertures of the luminaires disclosed in these two patents are rectangular and utilize elongated fluorescent lamping. While lamping-such as T5 lamping can be used in prior wall wash luminaires and even in the rectangular aperture luminaires disclosed in certain of the above-noted patents, it is to be understood that presently available wall wash luminaires have not exhibited performances approaching the goal of a visually smooth distribution of light on a vertical surface in linear wall wash configurations in luminaires using highly specular materials unless provided with a lens. It is therefore a particular intent of the present luminaire configurations to produce an acceptably smooth distribution of light on a vertical surface from a wall wash luminaire, particularly a small aperture luminaire, as can be mounted in recessed or surface-mounted applications in a ceiling at a distance from the vertical surface to be illuminated such that the cross-sectional aperture of the luminaire is small relative to the distance of the luminaire from a vertical surface that is to be illuminated. Luminaires configured according to the invention are configured to utilize highly reflective and highly specular reflective materials as reflector elements and are further configured to provide visually smooth lighting distributions on adjacent vertical surfaces such that striations and/or alternating relatively light and dark areas are reduced or visually eliminated, thereby providing a substantial advance in the art.
SUMMARY OF THE INVENTION
The invention provides in several embodiments luminaires adapted for efficient utilization of linear illumination sources such as tubular fluorescent lamps of differing type and dimension. The invention particularly intends improvement of luminaires of a kind typically referred to as “small aperture” luminaires including such luminaires intended for the “washing” of a wall or vertical surface with light generated from a location on or near a ceiling, such location being essentially adjacent to a vertical surface which is to be washed with light. The luminaires of the invention, including those luminaires often referred to as small aperture luminaires, are typically mounted in a recessed mode in a ceiling or surface-mounted to a ceiling, such ceilings typically being suspended or conventional drywall, plaster or the like. The luminaires of the invention are intended to provide a visually smooth distribution of light on a surface, particularly a vertical surface such as an adjacent wall when such luminaires are ceiling mounted. The invention further contemplates luminaires other than ceiling-mounted wall wash luminaires such as luminaires intended to direct light onto horizontal surfaces including pathways and the like. In such situations, luminaires such as bollards intended to illuminate areas adjacent such bollards can be configured to direct a smooth light distribution onto surfaces used by pedestrians as one example. The invention therefore finds utility in the general field of area lighting, pathway lighting, wall sconce uplighting, etc.
The invention finds particular utility in wall wash and other applications wherein linear illumination sources such as elongated tubular fluorescent lamps are employed, the invention being useful with illumination sources including T5 lamping. In luminaires configured according to the invention which utilize such lamping, the invention applies in certain embodiments to a luminaire genre such as is commonly referred to as a “small aperture” luminaire. A small aperture luminaire commonly employs elongated tubular fluorescent lamping, the aperture of such a luminaire being essentially as long as the lamping that is employed. As such, the apertures of small aperture luminaire is essentially elongated and of a length substantially equal to the length of the lamp or lamps employed for generation of light. It is therefore seen that such an aperture would typically be configured essentially as a rectangle although other shapes could be employed. In wall washing applications in particular, the essentially rectangular aperture of a luminaire configured according to the invention would have one elongated edge disposed substantially parallel to an adjacent wall which is to be washed with light, the small aperture luminaire being disposed in a ceiling adjacent to the wall or other vertical surface. The luminaire so located is provided with a reflector assembly configured to direct light reflected from lamping over at least portions of the adjacent wall, the reflector portions of the present reflector assembly being preferably formed of highly specular material with the result that lamp light imaged by the reflector assembly is effectively as bright as light from the lamp itself. In order to produce a visually smooth distribution of light on the adjacent wall, that is, a washing of the wall with light without striations or alternating relatively bright and relatively dark horizontally oriented areas, it is necessary according to the invention to configure the elongated edge of the aperture nearmost the adjacent wall in a manner to alter the vertical distance over which light from linear elements of the lamp and reflected lamp images are revealed in order to produce a smooth luminous gradient and to spread out illuminance changes over a relatively large angular zone or vertical distance on the lighted surface. The invention in several embodiments particularly contemplates the provision of structure on the “adjacent” elongated aperture edge that alters aperture geometry to cause a softening of what might otherwise be abrupt illuminance changes imaged onto the wall, thereby producing a smoother vertical distribution of light over the wall. Alteration of aperture geometry can be provided by the forming of the aforesaid adjacent aperture edge in the shape of a wedge in a preferred embodiment, thereby providing an “intrusion” into the aperture. Alternatively, the wedge shape of the adjacent aperture edge can be reversed or inverted to produce a desired result. For similar reasons, such intrusions can be configured by conforming the adjacent aperture edge to have a sawtooth edge, a sinusoidal edge, a gently rounded edge or the like over at least portions of said adjacent aperture edge, it being of greater moment to provide such an intrusion essentially at and/or near the center of said adjacent aperture edge. Apertures so configured according to the invention function particularly well with a reflector assemblies formed of highly specular material, it being possible through practice of the invention to utilize highly specular material in the formation of reflective surfaces without the concerns evident in the prior art which arise as a result of design and manufacturing errors including tolerances that cannot be controlled to a desirable degree in manufacturing and assembly processes. Luminaires configured according to the invention particularly provide wall or area washing capability with a desired visually smooth distribution of light on surfaces that are to be washed with light.
Accordingly, it is a primary object of the invention to provide luminaires capable of providing smooth light distributions on adjacent surfaces, such as ceiling-mounted luminaires capable of washing adjacent vertical surfaces with light, and wherein such luminaires are particularly intended to use elongated fluorescent lamping for generation of light thrown onto a surface through an elongated aperture having that lengthwise edge adjacent to the surface to be washed with light configured so as to increase the angular zone over which light from the lamping and light reflected from within the luminaire is revealed, thereby to produce a transition and spread what would otherwise be abrupt changes in luminance over a larger angular zone to reduce or effectively eliminate striations and the like in a pattern of light produced on the surface to be illuminated.
It is another object of the invention to provide luminaires such as are commonly referred to as “small aperture” luminaires wherein an elongated edge of such a luminaire is configured to be other than completely linear so as to produce a striation-free and relatively smooth distribution of light on an adjacent surface.
It is a further object of the invention to provide luminaires such as are commonly referred to as “small aperture” luminaires and which are intended for illuminating areas adjacent to said luminaires with a generally smooth distribution of light and wherein an elongated edge of such an aperture and adjacent to the area to be illuminated is caused to have at least portions thereof “intrude” into the aperture or alter the shape of the aperture in order to blend illuminance changes that are imaged onto the area and thereby provide a desired light distribution.
Further objects and advantages of the invention will become more readily apparent in light of the following detailed description of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a luminaire configured according to the invention and shown mounted in a recessed application in a ceiling seen in phantom only;
FIG. 2 is an exploded view of the luminaire of FIG. 1 ;
FIG. 3 is a cross-sectional view of the luminaire of FIG. 1 ;
FIG. 4 is a diagrammatical view illustrating the shape of the aperture of the luminaire of FIG. 1 ;
FIG. 5 is a diagrammatical view of another embodiment of an aperture configured according to the invention;
FIG. 6 is a diagrammatical view of yet another embodiment of an aperture configured according to the invention;
FIG. 7 is a diagrammatical view of a further embodiment of an aperture configured according to the invention;
FIG. 8 is a diagrammatical view of a still further embodiment of an aperture configured according to the invention; and,
FIG. 9 is a diagrammatical view of another aperture configured according to the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings and particularly to FIGS. 1 through 4 , a luminaire configured according to a preferred embodiment of the invention is seen at 10 to comprise a housing 12 of substantially rectangular configuration, the housing 12 being formed of sheet metal or the like such as is conventional in the art. The housing 12 has a lamp 14 mounted therein in a conventional manner in juxtaposition to a reflector assembly 16 having upper and lower reflectors 18 and 20 mounted together by means of a hinge 22 . It is to be understood that the reflectors 18 and 20 can be formed as a single reflector. The housing 12 is seen to contain a ballast 24 within a compartment thereof formed generally by upper portions of the housing 12 above the upper reflector 18 . The reflector assembly 16 is hinged by means of the hinge 22 to facilitate access to the ballast 24 and other structure associated with said ballast. The hinge 22 further permits adjustment of the relative positions of the upper reflector 18 and of the lower reflector 20 in order to provide the ability to alter the distribution of light on an adjacent wall (not shown) which is to be washed with light generated by the lamp 14 . The reflective surfaces of the reflectors 18 and 20 can be shaped in the configuration of a parabola or in any other desirable configuration.
The luminaire 12 as particularly seen in FIG. 1 is mounted in a recessed location within a ceiling 11 shown in phantom and is positioned in adjacent relation to a wall (not shown) which is to be washed with light as is known in the art. The luminaire 10 may be mounted within suspended ceilings or other ceiling structures such as can be formed with plasterboard and the like. As is seen in FIG. 3 , the luminaire 10 is mounted in a suspended ceiling 13 as will be readily understood by those of skill in the art. It is to be understood that surface-mounted and pendant-mounted luminaires can also be configured according to the teachings of the invention.
The lamp 14 is mounted within the housing 12 in a conventional manner by means of sockets 26 , the sockets 26 being mounted to brackets 28 disposed at either end of the housing 12 , the housing 12 being essentially finished by the mounting of end plates 30 at each end thereof. Access to the interior of the housing 12 from a location at the top of the luminaire 10 is provided in a conventional manner by means of an access plate 32 , the access plate 32 having knockouts 34 to permit electrical wiring (not shown) to extend from a power source (not shown) into the interior of the housing 12 as is conventional in the art.
The luminaire 10 has an aperture 36 formed essentially over a lower face of the housing 12 , the aperture 36 being that “open” portion of the housing 12 through which light passes directly from the lamp 14 from the luminaire 10 and through which light reflected from the reflector assembly 16 inter alia passes to wash an adjacent wall (not shown), the direction of the wall as seen in FIG. 3 being shown by the arrow 38 . The aperture 36 is defined by a forward edge 40 which essentially comprises an edge of a flange 42 which extends along a longitudinally disposed edge of the housing 12 essentially parallel to a wall that is to be washed with light. The forward edge 40 is essentially parallel to the lamp 14 , the lamp 14 preferably being an elongated fluorescent lamp which can take the form of conventional lamping such as T12, T8, T5 or similar lamping. Other lamping, particularly lamping of elongated configuration, can be utilized to advantage according to the teachings of the present invention.
An opposite longitudinal edge of the aperture 36 is defined by the terminus 44 of the lower reflector 20 , which terminus 44 can be configured to extend outwardly of the housing 12 as is best seen in FIG. 3 . The aperture 36 is further defined by oppositely disposed side edges 46 which are edges of the respective end plates 30 . In FIG. 3 , one of the edges 46 is shown by way of a dotted line in order to facilitate a more understandable illustration of the invention.
Considering FIG. 4 in addition to FIGS. 1 and 3 , it can be seen that the aperture 36 is substantially rectangular in conformation, the side edges 46 and that longitudinal edge provided by the terminus 44 of the lower reflector 20 defining three sides of a rectangular opening that is the aperture 36 . As can be seen in FIG. 1 but best illustrated in FIG. 4 , the forward edge 40 defining the remaining longitudinally-oriented side of the aperture 36 is seen to be formed in the shape of a wedge 48 which tapers from the side edges 46 to a maximum extent into the aperture 36 substantially centrally of the forward edge 40 . It is to be understood that FIG. 4 is not shown to scale, the length of the aperture 36 being reduced by approximately one-half in relation to the length of the side edges 46 in order to emphasize the shape of the wedge 48 . In essence, the wedge 48 acts as a desirable “intrusion” into the aperture 36 and thereby shapes the aperture 36 in order to cause light directed onto an adjacent wall to be smoothly distributed and without “striations” or alternating relatively light and dark lines as is common with conventional wall wash luminaires. It is therefore a primary teaching of the invention to provide structure along a forward edge of an aperture of any one of the luminaires disclosed herein so that changes in luminance from tamping such as the lamp 14 inter alia are delayed to thereby produce a smooth distribution over a surface that is to be washed with light. Essentially, the intrusion provided by the wedge 48 into the aperture 36 as seen in FIGS. 1 through 4 acts to increase the angular zone over which light from the lamp 14 and light imaged by the reflector assembly 16 are revealed to the wall, thereby to produce a transition and to blend out otherwise abrupt changes of luminance over a larger angular zone than would occur in the event that the forward edge 40 simply comprised a straight line edge as is conventional in the art. It is to be understood that variations in luminance can occur for a variety of reasons, among these reasons being differences in glass wall thicknesses of tamping such as the lamp 14 . Further, light reflected from a reflector, such as the reflector assembly 16 within luminaires such as are considered herein can be substantially less luminous than that light emanating directly from lamping such as the lamp 14 and passing directly through an aperture of conventional configuration. When highly specular material is used to form reflective surfaces within a luminaire of the kind referred to herein, it is even possible that reflected images can be of greater luminosity due to re-radiation of lighting flux. In such situations, design and manufacturing errors due to tolerances and the like can provide additional difficulties in controlling light directed onto a wall or other surface with desirably smooth distributions. It is to be appreciated that striations and the like are caused in applications referred to herein by the use of highly specular material in reflector formation. Abrupt changes in luminance are commonly encountered with linear sources of light and linear reflectors as are commonly used in luminaires of the kind considered herein, the sensitivity of lighting distribution to such abrupt changes in luminance occurring both from light emanating directly from the lamp and passing through an aperture and from lamp image reflected from a reflector within such a luminaire. As can thus be understood, any sudden gradation or sudden changes in the rate of gradation of light within such an aperture whether brighter or darker results in corresponding bright and dark stripes on a wall or other surface that is to be washed with light from such luminaires, these stripes being typically referred to as “striations” as referred to above. In such situations, an aperture opening formed solely of straight lines is susceptible to a less than smooth light distribution since these abrupt changes of luminance appear along the entire length of an aperture so configured at exactly the same vertical position on the lighted surface. The provision of the wedge 48 in the aperture 36 as described above results in a smoother distribution over a surface that is to be illuminated.
Referring further to FIGS. 1 through 3 in particular, a trim 50 can be disposed interiorly of the housing 12 and mounted by brackets 52 for decorative purposes and also for maintaining light generated by the lamp 14 within an optical chamber defined within the luminaire 10 in association with the reflector assembly 16 . That portion of the lower reflector 20 extending outwardly of the housing 12 as noted hereinabove acts to ensure appropriate direction of light onto a surface that is to be illuminated. The lower reflector 20 can be mounted within the housing 12 by means of integral flanges 54 and 56 as is conventional in the art. The reflectors 18 and 20 are preferably formed with highly specular reflective surfaces 58 and 60 respectively, the reflectors 18 and 20 preferably being aluminum extrusions with vacuum metallized finishes comprising the surfaces 58 , 60 , the surfaces 58 and 60 being of high specularity and high reflectance. It is to be understood that the luminaires disclosed herein are less susceptible to design and manufacturing errors such as are commonly encountered in the use of highly specular material as reflective surfaces and wherein lens structures are not provided to cover apertures. Prior luminaires of the kind referred to herein typically suffer from reduced lighting efficiency by virtue of the need to utilize diffuse or semi-specular reflective surfaces in reflector structure corresponding to the reflectors 18 , 20 as described herein. Configuration of apertures as described herein therefore permits use of highly specular material as surfaces for reflector structure without the difficulties inherent in the prior art, thereby permitting light generated by lamping to be more efficiently utilized.
Referring again to FIG. 4 , it is to be seen that an aperture such as the aperture 36 shown therein would typically have dimensions of approximately three inches along the side edges 46 and would be approximately forty-eight inches in lengthwise dimensions. It is to be appreciated that the dimensions of an aperture so configured can differ from those indicated with, for example, lengthwise dimensions being on the order of twenty-four inches with side edges such as the side edges 46 being three inches. Such dimensions accommodate commonly available lengths of tubular fluorescent lamping whether that lamping comprises single lamping or multiple lamps in an array with longitudinal axes being linearly arranged.
Further embodiments of the invention are provided respectively in FIGS. 5 through 10 as being exemplary of suitable configurations of apertures that can provide the functions and advantages noted herein. Referring first to FIG. 5 , it can be seen that a forward edge 62 of an aperture 64 can be formed essentially as the inverse of the wedge 48 of the aperture 36 . The configuration of FIG. 5 to produce the optical transition referred to hereinabove and therefore is intended to fall within the definition of the term “intrusion” as used herein since the edge 62 “intrudes” on side portions of the aperture 64 .
Referring now to FIG. 6 , a forward edge 66 of an aperture 68 configured according to a further embodiment of the invention is seen to take the form of a plurality of teeth 70 , such as in a sawtooth pattern, with the teeth 70 providing intrusions into the aperture 68 to provide the performance intended according to the invention. The teeth 70 can take the form of triangles of differing type and dimensions.
Referring now to FIG. 7 , a forward edge 72 of an aperture 74 is seen to be formed as a substantially sinusoidal curve 76 with portions of the curve 76 acting as intrusions into the aperture 74 . It is to be understood that the curve 76 could take other than a sinusoidal form.
Referring now to FIG. 8 , a forward edge 78 of an aperture 80 is seen to be formed arcuately at 82 , the edge 78 extending into the aperture 80 to provide the advantages herein described. The inverse shape of the edge 78 also functions to produce the performance described herein.
Now considering FIG. 9 , it is to be understood that an intrusion into an aperture similar to the aperture 36 shown in FIG. 4 is caused to occur essentially at central portions of an aperture, a forward edge 84 of an aperture 86 as seen in FIG. 9 being formed along central portions thereof as a wedge 88 , the wedge 88 extending from portions of the edge 84 near central portions thereof rather than tapering from ends thereof as occurs with the wedge 48 of the forward edge 40 shown in FIGS. 1 through 4 . Intrusions into apertures of luminaires as contemplated by the invention can thus be seen to be most efficiently provided along centrally disposed portions of forward edges of said apertures whether such intrusions take the form of wedges, teeth, arcuate elements or the like. The inverse shape of the edge 84 also functions to produce the performance described herein.
The intrusions into the apertures of luminaires as configured according to the invention are particularly seen to accommodate variations in luminance in lamping and inconsistencies in reflector structures such as are typically produced by extrusion processes. The improvements so provided are explicitly shown in the several embodiments particularly described. However, it is to be understood that the invention can be configured other than as is explicitly described herein, the scope of the invention being defined by the recitations of the appended claims. | Luminaires particularly useful for ceiling mounting in either recessed or surface-mounted applications and intended for “washing” light over an adjacent wall, the “wall wash” luminaires of the invention are configured in preferred embodiments for operation with elongated lamping and particularly tubular fluorescent lamping including T5 lamps. The present luminaires are usually provided with elongated and other apertures, certain of which are often referred to as “small” apertures, conformed by shaping of at least one elongated edge thereof to minimize alternating relatively light and dark striations on adjacent walls. Luminaires according to the invention having relatively narrow elongated apertures function to transition abrupt changes in luminance imaged onto an adjacent wall by alteration of aperture opening, such as by an extension of structure from one elongated edge of such an aperture, thereby to produce a more smooth vertical light distribution over the wall. | 5 |
FIELD OF THE INVENTION
The present invention is concerned with friction spinning and in particular with the maintenance of the operating performance of friction spinning apparatus.
Friction spinning uses suction forces to hold fibres on a friction spinning surface, and in some cases additional suction is used to control fibre movement and/or orientation as the fibres pass towards the friction spinning surface(s).
PRIOR ART
DE-A-334248l discloses a monitor incorporated in a servicing robot for checking the intensity of suction of a friction spinning unit being serviced, and for adjusting the suction (if necessary) in order to restore it to the preferred range of values. Such a servicing robot may be called to a friction spinning unit between doffing and re-piecing, or following a yarn break indicative of the need for restoration of the spinning parameters to the designed values. However, we have found that the quality of friction spun yarn can deteriorate markedly well before yarn break occurs, and during that time the spun yarn will be of impaired quality until such time as eventually yarn break occurs and then the servicing robot disclosed in DE-A-334248l would be called to investigate and correct the situation.
OBJECT OF THE INVENTION
It is an object of the present invention to anticipate the variation in yarn quality which we believe is directly linked to the suction forces.
It is another object of the present invention to provide apparatus and a method for monitoring continuously the suction applied to a friction spinning unit and for shutting-down that unit if the suction deviates from an optimum range of values.
SUMMARY OF THE INVENTION
Accordingly, one aspect of the present invention provides a friction spinning unit including at least one foraminous friction surface having suction applied thereto, means for feeding separated fibres to the friction surface to roll up to form spun yarn in operation of the friction spinning apparatus, and a suction switch responsive to the suction prevailing in said suction-applying means for discontinuing operation of the friction spinning apparatus when the suction sensed by the suction switch deviates from a predetermined range of values.
Preferably the friction spinning apparatus in question is a typical friction spinning unit of multi-position friction spinning machine and the means responsive to the suction switch for shutting down that friction spinning unit comprise the fibre feed means of that friction spinning unit.
More preferably the friction spinning unit includes a primary suction system to the inside of a foraminous friction spinning roller of the friction spinning unit, and an additional suction line to apply suction forces along the yarn formation line outside the or each friction spinning suction roller, the suction switch being connected in said additional suction line.
Advantageously the suction switch is a pressure transducer delivering an electrical signal to disengage a drive clutch to the sliver feed roller of the friction spinning unit.
A second aspect of the invention provides a method of operating a friction spinning unit, comprising continuously monitoring the suction applied to that friction spinning unit and disenabling the friction spinning unit when the monitored suction value deviates outside a predetermined range of acceptable suction values.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the present invention may be more readily understood the following description is given, merely by way of example, with reference to the accompanying drawing in which the sole Figure shows schematically a friction spinning unit in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The drawing shows a typical fibre feed duct 2 delivering fibres to a pair of friction spinning rollers 1, one of which is visible in the drawing. The fibres are individually transmitted along the fibre feed duct from a beater unit 16 where a toothed or pinned beater roller 17 combs out individual fibres from an incoming sliver 18, and the fibres are then transported pneumatically down the feed duct 2 towards the foraminous surface of the suction roller 1. The other friction spinning roller, not shown in the drawing, may be foraminous or may be imperforate, as is well known in the art.
Suction within the foraminous roller 1 is transmitted via a main suction line 3. An additional suction line 4 connected to the line 3 at point 9 is connected also to a point 8 near the outlet end of the fibre feed duct 2, but in such a position as to generate a flow of air rightwardly along the yarn formation line outside the foraminous roller 1. A suction tapping 5 connected to the additional suction line 4 also communicates with a suction transducer 6 which is in turn able to deliver an electrical signal for disenabling the feed clutch 7 to the sliver feed roller 19 which conveys sliver to the toothed or pinned beater roller 17 of the fibre-opening unit.
In use of the illustrated friction spinning unit, suction is applied to the main suction line 3 and the additional suction line 4 from a suction source, not shown, applying suction to a series of suction pipes 10 from a common suction manifold, each of the pipes 10 communicating with the respective main suction line 3 by way of a releasable coupling to allow removal of the friction spinning units, for example for maintenance purposes.
In the event of a fibre build-up occurring at the point 8, the strength of the suction-induced airflow along the yarn formation line is attenuated, and although the friction spinning unit still continues to deliver yarn without a yarn break occurring unless a very severe disruption of the suction forces results, the quality of the yarn will vary from the optimum value. The existence of such a blockage will, however, manifest itself at the pressure transducer 6 by the existence of a stronger suction (a lower absolute pressure) there due to the fact that the maintained suction value communicated to the friction spinning unit by way of its suction pipe 10 is no longer subject to the same total leakage path through both the main suction line 3 and the additional suction line 4.
Thus, instead of requiring to measure the quality of the yarn which is being delivered at speeds up to 300 m/min in order to monitor the quality of the production, it is possible to relate the variation of yarn quality, for example its varied strength, to the deviation of the suction value and to set the suction monitoring switch including the suction transducer 6 to disengage the clutch 7 once the yarn quality is likely to lie outside acceptable limits. Effectively, therefore, the suction monitoring system employing the suction transducer 6 provides a simple measure of yarn quality which constantly monitors the operating performance of the friction spinning unit and ceases production of yarn at any one of the friction spinning units of a multi-position machine where, for example due to a localised partial blockage of the suction system, the quality of yarn will have deviated beyond a predetermined adjustable tolerance from the optimum value.
Great care is taken in the design of the suction systems to avoid fibre entrapment sites, for example by ensuring that the edges of the suction lines at the junctions are smooth and the suction surfaces polished, and by ensuring that where one suction line joins another (for example the suction tapping 5 joining the additional suction line 4, or the suction line 4 joining either the fibre feed duct at 8 or the main pressure line 3 at 9) the joining line ends flush with the wall surface of the other line which it joins. However, there is always the possibility of some fibre build-up which rapidly increases as fresh fibres accumulate at the nucleus site formed by the first few collecting fibres. This can give rise to localised variation of suction which will alter the quality of the spun yarn but without necessarily leading to a yarn break. In accordance with the present invention we close down that friction spinning unit long before a yarn break caused by excessive quality impairment occurs, and the friction spinning unit in question is then cleaned and serviced before re-piecing.
Although above we have mentioned the point 8 as one likely site for fibre build-up, it is of course possible for fibre build-up instead to occur at point 9, in which case the suction sensed by the transducer 6 will be attenuated but will still lie outside the optimum suction range and will, therefore, lead the suction switch comprising the transducer 6 and the clutch 7 to shut-down that spinning unit.
A third possible blockage condition is if blockage occurs in the suction insert within the perforated friction spinning roller 1 in which case again the total leakage path for the suction applied at the suction pipe 10 will decrease, giving rise to a stronger suction at the transducer 6.
It will of course be appreciated that a sophisticated control unit may be incorporated in the pressure switch between the transducer 6 and the clutch 7, in order to allow adjustment, from unit to unit, of the range of suction values within which the friction spinning unit can operate before the fibre feed clutch 7 is disengaged.
The monitoring of the suction is of course one of many parameters which will be monitored in use of the friction spinning unit.
As an example, it is possible for a management system for the friction spinning unit to include a controller generally designated 11 having one input 12 which is responsive to the yarn properties, and also another input 13 from the suction switch in accordance with the present invention. One possibility is for a multi-channel monitoring system including (i), on the input 12, a signal from a yarn monitoring head 14 which is indicative of the linear density of the yarn 15 and which can be analysed to provide for one channel recording the number of "thick places" in the yarn, and another channel monitoring the number of "thin places" in the yarn, and (ii), on the input 13, the electrical signal from the suction transducer 6. The management system shuts down the friction spinning unit in the event of the measured suction deviating from the desired value sufficiently to operate the suction transducer 6. The tolerance of the suction deviation permitted may be adjusted by means of a tolerance adjustment sub-assembly 11a of the controller 11.
Such a management system has the advantage of (a) logging the thick and thin places in the yarn, and possibly in indicating the individual spinning unit by way of an alarm system, or even shutting it down, when the frequency of such events exceeds a value preselected by means of a frequency selector sub-assembly 11b of the controller 11, and (b) not only giving an alarm on shutting down the friction spinning unit when the pressure switch signal deviates from the norm, but also recording the reason for that alarm or shut down so that repetitive suction problems on a given friction spinning unit will be highlighted in the print-out analysis offered by such a management system.
Although the accompanying drawing shows one input 12 and on input 13 to the management system controller 11, it will of course be appreciated that such a monitoring/management system will normally be centralised for an entire multi-position spinning machine and will receive individual inputs from the various spinning units and from the respective yarn monitors 14 associated therewith, and will equally control each of those spinning units in response to its suction and yarn linear density signals.
Such a system offers not only quality control of the yarn, but also an assurance that yarn will not be spun if the friction-controlling forces (e.g. suction) are outside the expected range (bearing in mind that suction which is one of the key factors in the yarn-to-surface friction in a friction spinning unit). | A friction spinning unit of a multi-position friction spinning machine includes a pressure tapping in the suction line to a suction port in the fibre feed duct. A suction transducer responsive to the suction in the tapping controls the fibre feed clutch of that particular friction spinning unit for disengaging the friction spinning unit when suction value sensed by the transducer deviates from a predetermined range of acceptable suction values, to shut-down the friction spinning unit well before the yarn quality has been impaired to a sufficient extent to cause a yarn break. | 3 |
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to Provisional Application Ser. No. 60/410,263, filed Sep. 12, 2002.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
REFERENCE TO A “COMPUTER LISTING APPENDIX SUBMITTED ON A COMPACT DISC”
[0003] Not Applicable.
BACKGROUND OF THE INVENTION
[0004] (1) Field of the Invention
[0005] Expanded graphite is provided in the present invention. The present invention relates in part to polymer-expanded graphite composites. The graphite platelets are preferably reduced in size to less than about 200 microns. The invention also relates to expanded graphite used for fuel cells, for battery anodes and for catalytic converters. The graphite is preferably expanded using microwave or radiofrequency wave heating.
[0006] (2) Description of Related Art
[0007] Graphite is a well known material occurring in natural and synthetic form and is well described in the literature. Illustrative of this art is a monograph by Michel A. Boucher, Canadian Minerals Yearbook 24.1-24.9(1994).
[0008] Nanocomposites composed of polymer matrices with reinforcements of less than 100 nm in size, are being considered for applications such as interior and exterior accessories for automobiles, structural components for portable electronic devices, and films for food packaging (Giannelis, E. P., Appl. Organometallic Chem., Vol. 12, pp. 675 (1998); and Pinnavaia, T. J. et al., Polymer Clay Nanocomposites. John Wiley & Sons, Chichester, England (2000)). While most nanocomposite research has focused on exfoliated clay platelets, the same nanoreinforcement concept can be applied to another layered material, graphite, to produce nanoplatelets and nanocomposites (Pan, Y. X., et al., J. Polym. Sci., Part B: Polym. Phy., Vol. 38, pp. 1626 (2000); and Chen, G. H., et al., J. Appl. Polym. Sci. Vol. 82, pp. 2506 (2001)). Graphite is the stiffest material found in nature (Young's Modulus=1060 MPa), having a modulus several times that of clay, but also with excellent electrical and thermal conductivity.
[0009] A useful form of graphite is expanded graphite which has been known for years. The first patents related to this topic appeared as early as 1910 (U.S. Pat. Nos. 1,137,373 and 1,191,383). Since then, numerous patents related to the methods and resulting expanded graphites have been issued. For example, many patents have been issued related to the expansion process (U.S. Pat. Nos. 4,915,925 and 6,149,972), expanded graphite-polymer composites (U.S. Pat. Nos. 4,530,949, 4,704,231, 4,946,892, 5,582,781, 4,091,083 and 5,846,459), flexible graphite sheet and its fabrication process by compressing expanded graphite (U.S. Pat. Nos. 3,404,061, 4,244,934, 4,888,242, 4,961,988, 5,149,518, 5,294,300, 5,582,811, 5,981,072 and 6,143,218), and flexible graphite sheet for fuel cell elements (U.S. Pat. Nos. 5,885,728 and 6,060,189). Also there are patents relating to grinding/pulverization methods for expanded graphite to produce fine graphite flakes (U.S. Pat. Nos. 6,287,694, 5,330,680 and 5,186,919). All of these patents use a heat treatment, typically in the range of 600° C. to 1200° C., as the expansion method for graphite. The heating by direct application of heat generally requires a significant amount of energy, especially in the case of large-scale production. RF or microwave expansion method can heat more material in less time at lower cost. U.S. Pat. No. 6,306,264 discusses microwave as one of the expansion methods for SO 3 intercalated graphite.
[0010] U.S. Pat. Nos. 5,019,446 and 4,987,175 describe graphite flake reinforced polymer composites and the fabrication method. These patents did not specify the methods to produce thin, small graphite flakes. The thickness (less than 100 nm) and aspect ratio (more than 100) of the graphite reinforcement was described.
[0011] Many patents have been issued related to anode materials for lithium-ion or lithium-polymer batteries (U.S. Pat. Nos. 5,344,726, 5,522,127, 5,591,547, 5,672,446, 5,756,062, and 6,136,474). Among these materials, one of the most widely investigated and used is graphite flakes with appropriate size, typically 2 to 50 μm, with less oxygen-containing functional groups at the edges. Most of the patents described graphite flakes made by carbonization of precursor material, such as petroleum coke or coal-tar pitch, followed by graphitization process.
SUMMARY OF THE INVENTION
[0012] An important aspect of utilizing graphite as a platelet nanoreinforcement is in the ability to expand this material. With surface treatment of the expanded graphite, its dispersion in a polymer matrix results in a composite with not only excellent mechanical properties but electrical properties as well, opening up many new structural applications as well as non-structural ones where electromagnetic shielding and high thermal conductivity are requirements. In addition, graphite nanoplatelets are ˜500 times less expensive than carbon nanotubes.
[0013] Thus the present invention relates in part to a composite material which comprises:
[0014] (a) finely divided expanded graphite consisting essentially of single platelets which are less than 200 microns in length; and
[0015] (b) a polymer having the expanded graphite platelets dispersed therein.
[0016] In particular, the present invention relates to a composite material which comprises:
[0017] (a) finely divided expanded graphite having single platelets with a length less than about 200 microns and a thickness of less than about 0.1 microns; and
[0018] (b) a polymer having the expanded graphite particles dispersed therein, wherein the composite material contains up to 50% by volume of the graphite platelets. Preferably the expanded graphite platelets are present in an amount so that composite material is conductive.
[0019] A graphite precursor containing a chemical which was vaporized by heat to form the expanded graphite. In most cases, the chemical should be removed, preferably by heating, from the graphite by sufficient heating before mixing with polymers, since the chemical can degradate polymers. Preferably the expanded graphite has been formed in a radiofrequency wave applicator by heating the graphite precursor with the radiofrequency waves. Preferably a precursor graphite has been treated with a fuming oxy acid and heated to form the expanded graphite particles. Good results have been achieved with expanded graphite composites surface treated with acrylamide or other surface modifying treatments.
[0020] The invention applied to thermoset polymer systems, such as epoxy, polyurethane, polyurea, polysiloxane and alkyds, where polymer curing involves coupling or crosslinking reactions. The invention is applied as well to thermoplastic polymers for instance polyamides, proteins, polyesters, polyethers, polyurethanes, polysiloxanes, phenol-formaldehydes, urea-formaldehydes, melamine-formaldehydes, celluloses, polysulfides, polyacetals, polyethylene oxides, polycaprolactams, polycaprolactons, polylactides, polyimides, and polyolefins (vinyl-containing thermoplastics). Specifically included are polypropylene, nylon and polycarbonate. The polymer can be for instance an epoxy resin. The epoxy resin cures when heated. The epoxy composite material preferably contains less than about 8% by weight of the expanded graphite platelets. Thermoplastic polymers are widely used in many industries. The expanded graphite can also be incorporated into ceramics and metals.
[0021] Further the present invention relates to a method for preparing a shaped composite which comprises:
[0022] (a) providing a mixture of a finely divided expanded graphite consisting essentially of single platelets which are essentially less than 200 microns in length and with a polymer precursor with the expanded platelets dispersed therein; and
[0023] (b) forming the shaped composite material from the mixture.
[0024] In particular, the present invention relates to a method for preparing a shaped composite material which comprises:
[0025] (a) providing a mixture of an expanded graphite having single platelets with a length less than about 200 microns and a thickness of less than about 0.1 microns with a polymer precursor with the expanded graphite platelets dispersed therein, wherein the composite material contains up to about 50% by volume of the expanded graphite platelets;
[0026] (b) forming the shaped composite material from the mixture.
[0027] Preferably the expanded graphite is provided in the polymer in an amount sufficient to render the shaped composite conductive. Preferably the expanded graphite has been expanded with expanding chemical which can be evaporated upon application of heat. Preferably the expanded graphite platelets are formed in a radiofrequency wave applicator by heating the graphite precursor with radiofrequency waves and then the expanding chemical is removed to form the graphite precursor. Preferably a graphite precursor is treated with a fuming oxy acid and heated to provide the expanded graphite particles.
[0028] The present invention also relates to an improvement in a battery containing ions in the anode which comprises a finely divided microwave or RF expanded graphite having single platelets with a length less than about 200 microns and a thickness of less than about 0.1 microns.
[0029] The present invention also relates to an improvement in a catalytic conversion of an organic compound to hydrogen with a catalytic material deposited on a substrate the improvement in the substrate which comprises a finely divided microwave or RF expanded graphite having single particles with a length less than about 200 microns and a thickness of less than about 0.1 microns.
[0030] Finally the present invention relates to a process for producing platelets of expanded graphite which comprises:
[0031] (a) expanding graphite intercalated with a chemical which expands upon heating to produce expanded graphite platelets; and
[0032] (b) reducing the expanded graphite platelets so that essentially all of the individual platelets are less than 200 microns in length, 0.1 micron in thickness. Preferably the chemical agent is an inorganic oxy acid. Preferably the expanding is by microwave or RF heating. Preferably the graphite is surface modified such as with acrylamide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] FIG. 1 is a scanning electron microscope (SEM) of intercalated graphite flakes.
[0034] FIG. 2 is a SEM image of expanded natural graphite flakes wherein the flakes are expanded by microwave.
[0035] FIG. 3 is a graph of an x-ray diffraction pattern of intercalated natural graphite of FIG. 1 . Some order is seen.
[0036] FIG. 4 is a graph of an x-ray diffraction pattern of the expanded natural graphite of FIG. 2 . No order is seen.
[0037] FIG. 5 is a SEM of pulverized exfoliated (expanded) natural graphite.
[0038] FIG. 6 is a graph showing the size distribution of the particles of FIG. 5 after being pulverized.
[0039] FIGS. 7 and 8 are graphs showing the flexural modulus ( FIG. 7 ) and strength ( FIG. 8 ) of cured epoxy resins containing 3% by volume of the pulverized graphite particles of FIGS. 5 and 6 .
[0040] FIG. 9 is a graph of the resistivity of control and graphite nanoplatelet reinforced composites of FIGS. 7 and 8 as a function of volume percent exfoliated graphite (Gr).
[0041] FIGS. 10A and 10B are TEM images of graphite nanoplatelets in the polymer matrix of FIGS. 7 and 8 .
[0042] FIG. 11 is a graph showing flexural strength versus expanded graphite content for acrylamide grafted graphite.
[0043] FIG. 12 is a graph showing flexural modulus versus acrylamide grafted expanded graphite content for acrylamide grafted graphite.
[0044] FIGS. 13 to 18 are graphs showing flexural strength and modulus for acrylamide modified graphite and various carbon materials. “MW” is microwave, and “AA” is acrylamide.
[0045] FIGS. 19 to 21 are SEM images of various carbon materials. FIG. 19 is PAN based carbon fiber, FIG. 20 is carbon film and FIG. 21 is carbon black.
[0046] FIGS. 22 to 24 are SEM images showing graphite in various forms.
[0047] FIGS. 25 and 26 are TEM images of graphite nanoplatelets.
[0048] FIGS. 27 and 28 are graphs showing size distribution of graphite microplates and graphite nanoplatelets.
[0049] FIGS. 29 and 30 are graphs comparing flexural strength and modulus for various samples including graphite modified with acrylamide.
[0050] FIGS. 31 and 32 are graphs of flexural strength and modulus for various carbon containing materials versus acrylamide grafting.
[0051] FIG. 33 is a graph showing coefficient of thermal expansion (CTE) of various composites with 3% by volume reinforcements and without reinforcement.
[0052] FIG. 34 is a graph showing Tg for various composites with 3% volume percent of reinforcements and without reinforcements.
[0053] FIG. 35 is a graph showing electrical resistivity of the components versus percentage of reinforcement by weight.
[0054] FIG. 36 is a graph showing electrical percolation threshold for various composites as a function of weight percent.
[0055] FIG. 37 is a graph showing impact strength for various composites.
[0056] FIG. 38 is a separated perspective view of the basic structure of a polymer battery. Cathode and Anode: electrically conducting polymer on substrate. Polymer gel electrolytes: Ionically conducting polymer gel film.
[0057] FIG. 39 is a schematic view of the basic structure of a fuel cell.
[0058] FIG. 40 is a schematic view of the basic structure of a lithium ion-battery.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0059] Graphite is a layered material. Individual molecular layers are held together with weak Van der Waals forces which are capable of intercalation with organic or inorganic molecules and eventual expansion. These nanosized expanded graphite platelet materials are very large platelets having large diameters and are very thin in thickness. The graphite structure is stiff in bending. Graphite is a very good thermal and electrical conductor.
[0060] Expanded graphite provides superior mechanical properties and in addition provides electrical properties if a sufficient amount is present in a polymer matrix. Expanded graphite platelets have interbasal plane surfaces which have reactive sites on the edges of the platelets. Different chemical groups can be added to the edges. The application of an electric field can be used to orient the expanded graphite platelets in a preferred direction creating materials which are electrically or thermally conductive in one direction. Submicron conductive paths can be created to act as nanosized wires.
[0061] As used in the present application an expanded graphite is one which has been heated to separate individual platelets of graphite. An exfoliated graphite is a form of expanded graphite where the individual platelets are separated by heating with or without an agent such as a polymer or polymer component. In the present application the term “expanded graphite” is used. The expanded graphite usually does not have any significant order as evidenced by an x-ray diffraction pattern.
[0062] The use of microwave energy or RF induction heating provides a fast and economical method to produce expanded graphite nanoflakes, graphite nanosheets, or graphite nanoparticles. The microwave or RF methods are especially useful in large-scale production and are very cost-effective.
[0063] The combination of RF or microwave expansion and appropriate grinding technique, such as planetary ball milling (and vibratory ball milling), produces nanoplatelet graphite flakes with a high aspect ratio efficiently. Microwave or RF expansion and pulverization of the crystalline graphite to produce suitable graphite flakes enables control of the size distribution of graphite flakes more efficiently. By incorporating an appropriate surface treatment, the process offers an economical method to produce a surface treated expanded graphite.
[0064] Chemically intercalated graphite flakes are expanded by application of the RF or microwave energy. The expansion occurs rapidly. Heating for 3 to 5 minutes removes the expanding chemical. The graphite absorbs the RF or microwave energy very quickly without being limited by convection and conduction heat transfer mechanisms. The intercalant heats up past the boiling point and causes the graphite to expand to many times its original volume. The process can be performed continuously by using a commercially available induction or microwave system with conveyors.
[0065] Although a commercial microwave oven operating at 2.45 GHz was used for the following experiments, radio frequency (induction heating) or microwave frequency energy across a wide range can be used for this purpose.
[0066] The expanded graphite is pulverized for instance by ball milling, mechanical grinding, air milling, or ultrasonic wave to produce graphite flakes (platelets) with high aspect ratio. These flakes are used as reinforcements in various matrices including polymers and metals. Also these flakes can be used, for instance, as anode materials, or substrates for metal catalysts. The exfoliated graphite flakes can be provided in a polymer matrix composite to improve the mechanical, electrical and thermal properties.
[0067] Specifically, intercalated graphite flakes are expanded by application of microwave energy at 2.45 GHz. This process can be done continuously by using a commercially available microwave system with conveyors. After the expansion, the graphite material is calendared, with or without binder resins, to form a flexible graphite sheet. The resultant sheet is cut into various sizes and shapes and used as gaskets, sealing material, electrode substrates, and separators for fuel cells.
[0068] Applications for the expanded graphite include thermally, electrically and structural nanoreinforcements for polymers and metals, electrode substrates for batteries, separators for fuel cells, anode material, or substrates for metal catalysts.
EXAMPLE 1
[0069] The graphite was expanded before the polymer is introduced. Intercalated graphite flakes were expanded by exposure to microwave energy, typically at 2.45 GHz frequency, for a few seconds to a few minutes in an oven. This process can be done continuously by using commercially available microwave systems with conveyors or batch-style process using individual microwave ovens. An automated continuous system is preferred from an economical point of view. In this case, the intercalated graphite flakes are first dispersed on a conveyor and introduced into the microwave oven, then processed under controlled conditions. Before or during this process additional chemicals/additives can be added to the intercalated graphite flakes to enhance the exfoliation, and/or apply surface treatments to the graphite flakes. After this process, washing and drying processes are applied, if necessary.
[0070] Typical starting materials are natural graphite flakes intercalated with oxidizing agents, but synthetic graphite, kish graphite, or the like can also be used. A preferred intercalating agent is a mixture of sulfuric acid or sulfuric acid/phosphoric acid mixture and an oxidizing agent such as nitric acid, perchloric acid, chromic acid, potassium chlorate potassium permanganate, potassium dichromate, hydrogen peroxide, metal halides or the like.
[0071] FIG. 1 shows a SEM image of intercalated natural graphite flakes. The microwave process heated the graphite flake, thereby heating the intercalated acid causing a rapid expansion of the graphite flakes perpendicular to the basal planes. During the process, the flakes expanded as much as 300 times or more, but still many of the layers were attached together and form worm-like shapes. FIG. 2 shows a SEM image of expanded graphite material. FIGS. 3 and 4 show XRD data of intercalated natural graphite and expanded graphite processed by the microwave process. As FIG. 4 shows, the x-ray diffraction peak due to the highly and closely aligned graphite sheets was significantly reduced because of the expansion of the intercalated graphite by the microwave process. The expanded graphite can be pressed to form flexible graphite sheet. The thickness of the sheet can be controllable, depending on the application.
[0072] The expanded graphite was pulverized into the small platelets which have been crushed. FIGS. 5 and 6 show a SEM image and size distribution of expanded graphite platelets. The size of most graphite particles is 1 um or less after milling.
[0073] After the expansion, the graphite material can then be pressed into sheet or pulverized into small flakes. In the former case, the expanded graphite flakes are pressed by calendar roll, press machine, or any other press methods, with or without binder resins, to form a flexible graphite sheet. The resulting sheet can be cut into various sizes and shapes and can be used as gaskets, sealing material, electrode substrates, separators in fuel cells or many other applications. In the latter case, the expanded graphite flakes are pulverized by ball milling, planetary milling, mechanical grinding, air milling, ultrasonic processing or any other milling methods to produce graphite flakes with a high aspect ratio. These expanded flakes can also be given further surface treatments and can be used as reinforcements in various matrices including polymers, ceramics, and metals. Also these flakes and/or sheets can be used as electrodes and/or other parts for batteries, or electrodes, separators, and/or other parts materials for fuel cells, or substrates for various catalysts in many chemical/biological reactions.
[0074] The expanded graphite nanoplatelets can be incorporated into various types of matrices, including thermoplastic and thermoset polymers. Before mixing with the polymeric matrix, surface treatments can be applied to the graphite nanoplatelets to enhance the adhesion between graphite platelets and matrix and the dispersion of the platelets in the polymer. An example of composite fabrication and its properties is described below.
EXAMPLE 2
[0075] Graphite flake that has been treated in the sulfuric acid to intercalate the graphite with sulfuric acid in between the layers was used. A commercial source used in this invention is GRAFGUARD™ which is produced by UCAR Carbon Company (Lakewood, Ohio).
[0076] Samples of acidic, neutral or basic intercalated graphite (GRAFGUARD™ 160-50N, 160-50A or 160-50B from UCAR Carbon Company, Parma, Ohio) were mixed into pure epoxy resin such as diglycidylether of bisphenol-A (DGEBA) Shell Epon 828 or equivalent. The mixture was heated to temperatures of at least 200° C. at which time approximately the graphite experiences a 15% weight loss due to the release of the trapped sulfuric acid compounds. At the same time, the epoxy molecule entered the space between the graphite layers. A very large volume expansion was encountered which results in sorption of the epoxy in between the graphite layers. This expanded graphite was dry to the touch indicating that all of the epoxy has been sucked into the galleries between the platelets. After cooldown, further epoxy and a curing agent were added to this mixture and a composite material was fabricated. There are various other routes available to attain the same end point of removal of the sulfuric acid and intercalation of the epoxy or similar polymer monomer in-between the graphite layers. One way is to remove the acid from the expanded graphite by heating.
[0077] Samples were made and mechanical properties were measured to show that the graphite has been intercalated and exfoliated (expanded) by the polymer.
EXAMPLE 3
[0078] Composite samples were fabricated using the following steps. First, 1, 2, or 3 vol % (1.9, 3.8 or 5.8 wt %) of the expanded graphite nanoplatelets of Example 2 were added into the epoxy systems. (Epoxide; Shell Chemicals, EPON™ 828 (DGEBA), Curing Agent: Huntsman Corporation, JEFFAMINE™ T403. The weight ratio of EPON™ 828 to JEFFAMINE™ T403 was 100 to 45.) Then the mixtures were cured by heating at 85° C. for 2 hours followed by 150° C. for 2 hours. The heating ramp rate was 3° C. per min. At the same time, a reference system was made that did not have expanded graphite platelets in it but was composed of the same epoxy system from the same batch. The mechanical properties of these samples were determined. These samples were investigated by flexural test. Also, the AC conductivity of these materials was measured.
[0079] FIGS. 7 and 8 show the results of the flexural test. The composite materials with 3 vol % graphite showed about 28% of improvement in modulus and 12% improvement in strength compared to the matrix material. This is an excellent increase with respect to the relatively small amount of platelets reinforcements added to the system.
[0080] FIG. 9 shows the AC resistivity of the control epoxy and the graphite nanoplatelet reinforced composites. With 2% weight of graphite platelets, the composite began displaying some conductivity, which means that percolation threshold of this material exists around 2% weight percent (1% in value). With 3% volume graphite platelets, the composite shows a reduction of about 10 orders of magnitude which is a low enough resistivity for electrostatic dissipation or electrostatic painting applications.
[0081] The microstructure of the composite was observed by preparing microtomed samples and viewing them in the transmission electron microscope (TEM). The images are shown in FIGS. 10A and 10B . According to these images, the thickness of these nanoplatelets was estimated around 15 to 30 nm. Multiple treatments by the microwave process can reduce the platelet thickness to much smaller dimensions.
EXAMPLE 4
[0082] This Example shows acrylamide grafting on a microwaved and milled graphite platelet. The objective was to demonstrate the mechanical properties of composites reinforced with acrylamide grafted graphite nanoplatelets.
[0083] The graphite sample was microwave-exfoliated and vibratory milled. The vibratory milling was for 72 hrs. The average diameter was about 1 um.
[0084] The conditions for the grafting process were as follows:
[0000] Factors
[0000] 1. Solvent System (O2 Plasma treatment: 1 min. moderate reflux condition)
[0085] Benzene
[0086] Acetone
[0087] Isopropyl alcohol
[0088] Benzene/Acetone=50/50
[0089] Benzene/Acetone=75/25
[0090] Benzene/Acetone=87.5/12.5
[0000] 2. O2 Plasma Treatment Time (solvent: Benzene. Moderate reflux condition)
[0091] 0 min
[0092] 0.5 min
[0093] 1 min
[0094] 3 min
[0000] 3. Reflux condition solvent: Benzene. O2 Plasma treatment: 1 min)
[0095] Moderate reflux. Hot Plate Temperature=110˜120° C.
[0096] Vigorous reflux. Hot Plate Temperature=140˜150° C.
[0000] The reaction procedure was:
[0097] The graphite samples were first treated with O2 plasma. (RF 50%); the sample was then dispersed in a 1M-Acrylamide solution and refluxed for 5 hours; and the sample was filtered and washed with acetone, then dried in a vacuum oven.
1. Solvent System Solvent Organic Component Benzene 15.37 wt % Acetone 6.39 wt % Isopropyl Alcohol 2.16 wt % Benzene/Acetone = 50/50 21.84 wt % Benzene/Acetone = 75/25 18.95 wt % Benzene/Acetone = 87.5/12.5 17.75 wt %
[0098]
2. O2 Plasma Treatment Time
Plasma Treatment Time
Organic Component
0 min
2.91 wt %
0.5 min
9.73 wt %
1 min
15.37 wt %
3 min
11.53 wt %
[0099]
3. Reflux Condition
Reflux Condition
Organic Component
Moderate Reflux
15.37 wt %
Vigorous Reflux
38.25 wt %
[0100] The mechanical properties of composites of acrylamide grafted graphite are shown in FIGS. 11 and 12 for a graphite sample with 38.25 wt % acrylamide.
[0101] The effect of acrylamide grafting in forming composites with the epoxy resin of Example 3 is shown in FIGS. 13 to 18 .
EXAMPLE 5
[0102] Composites reinforced with nanoscopic graphite platelets were fabricated and their properties were investigated as a practical alternative to carbon nanotubes. The x-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) results indicated that the graphite flakes were well-exfoliated to achieve platelets with thicknesses of 20 nm or less. Flexural tests and Differential Mechanical Thermal Analysis (DMTA) results show that nanocomposite materials made with these nanographite platelets have higher modulus than that of composites made with commercially available carbon reinforcing materials (i.e., PAN based carbon fiber, Vapor Grown Carbon Fiber [VGCF], and Nanoscopic High-structure Carbon Black). With the proper surface treatment, the graphite nanoplatelets in polymeric matrices also showed better flexural strength than composites with other carbon materials. Impedance measurements have shown that the exfoliated graphite plates percolate at below 3 volume percent, which is better than carbon fiber and comparable with other carbon materials, and exhibit a ˜10 order of magnitude reduction in impedance at these concentrations.
[0103] In this Example, a special thermal treatment was applied to the graphite flakes to produce exfoliated graphite reinforcements. The composite material was fabricated by combining the exfoliated graphite flakes with an amine-epoxy resin. X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) were used to assess the degree of exfoliation of the graphite platelets. The mechanical properties of this composite were investigated by flexural testing. The glass transition temperature (Tg) of composite samples was determined by Differential Mechanical Thermal Analysis (DMTA). The coefficient of thermal expansion was examined by Thermal Mechanical Analysis (TMA). The electrical conductivity was investigated by impedance measurements using the 2-probe method.
[0000] Experimental
[0000] Materials
[0104] Epoxy was used as the matrix material. Diglycidyl ether of bisphenol A (Epon 828) was purchased from the Shell Chemical Co. Jeffamine T403 from Huntsman Petrochemical was used as the curing agent for this matrix system.
[0105] Graphite was obtained from UCAR International Inc. and were intercalated by acids. PAN based carbon fiber (PANEX 33 MC Milled Carbon Fibers, average length: 175 um, average diameter: 7.2 um, specific gravity: 1.81 g/cm 3 , Zoltek Co.), VGCF (Pyrograf III, PR-19 PS grade, Length: 50˜100 um, Average diameter: 150 nm, Specific gravity: 2.0 g·cm 3 , Pyrograf Products, Inc.), and nanosize carbon black (KETJENBLACK EC-600 JD, Average diameter: 400˜500 nm, Specific gravity: 1.8 g/cm 3 , Akzo Novel Polymer Chemicals LLC) were used as comparison. The SEM images of these materials are shown in FIGS. 19, 20 and 21 .
[0106] The UCAR graphite was processed thermally. After the treatment, these graphite flakes showed significant expansion due to the vaporization of intercalated acid in the graphite galleries. The expanded graphite flakes were pulverized by use of an ultrasonic processor and mechanical milling. The average diameter and thickness of the flakes pulverized only by ultrasonic processor were determined as 13 um and 30 nm, respectively (Graphite microplate). Those of the flakes after milling were determined as 1.1 um and 20 nm, respectively (Graphite nanoplatelet). The SEM and TEM images of as-received, expanded, and pulverized graphite flakes are shown in FIGS. 22 to 25 . The size distribution of the graphite microplate and nanoplatelets is shown in FIGS. 27 and 28 .
[0000] Composite Fabrication
[0107] The calculated amount of reinforcements were added to DGEBA and mixed with the aid of an ultrasonic homogenizer for 5 minutes. Then stoichiometric amount of Jeffamine T403 were added and mixed at room temperature. The ratio of DGEBA/Jeffamine is 100/45 by weight. The system was outgassed to reduce the voids and cured at 85° C. for 2 hours, followed by post curing at 150° C. for 2 hours. The density of graphite flakes was assumed as 2.0 g/cm 3 . The densities of other carbon materials were obtained from manufactures. The density of the epoxy matrix was measured as 1.159 g/cm 3 . Using these values, the volume fraction of graphite platelets in composite samples was calculated.
[0000] Surface Treatments of Graphite Nanoplatelets
[0108] Surface treatments that can introduce carboxyl and/or amine group were applied to the graphite according to the following procedures.
[0000] Nitric Acid Treatment
[0109] A graphite nanoplatelet sample was dispersed in 69% (weight) of nitric acid and heated at 115° C. for 2 hours. The sample was then washed by distilled water and dried in a vacuum oven.
[0000] O 2 Plasma Treatment
[0110] Graphite nanoplatelets were dispersed on an aluminum foil and covered by a stainless steel mesh. Then the sample was treated by O2 plasma at RF level of 50% (275 W) for 1 min.
[0000] UV/Ozone Treatment
[0111] Graphite nanoplatelets were packed in a quartz tube (ID: 22 mm, OD: 25 mm, Transparent to UV light down to wave length of 150 nm). The tube was filled with ozone (Concentration: 2000 ppm, Flow rate: 4.7 L/min) and rotated at 3 rpm. Then the samples were exposed to UV light for 5 min.
[0000] Amine Grafting
[0112] Graphite nanoplatelets were treated by O 2 plasma to introduce carboxyl group. Then the sample was dispersed in tetraethylenepentamine (TEPA) and heated at 190° C. for 5 hours to graft TEPA by forming an amide linkage. The sample was washed with distilled water and methanol, then dried in a vacuum oven (Pattman, Jr., et al., Carbon, Vol. 35, No. 3, pp. 217 (1997)).
[0000] Acrylamide Grafting
[0113] Graphite nanoplatelets were treated by O 2 plasma to introduce peroxide. Then the sample was dispersed in 1M acrylamide/benzene solution and heated at 80° C. for 5 hours to initiate radical polymerization of acrylamide. The sample was washed with acetone and dried in a vacuum oven (Yamada, K., et al., J. Appl. Polym. Sci., Vol. 75, pp. 284 (2000)).
TABLE 1 XPS Data of Surface Treated Graphite Nanoplatelets and Other Carbon Materials C O N S Na Al Others O/C N/C Graphite 93.5 6.1 0.0 0.0 0.0 0.0 0.4 0.055 0.000 Nanoplatelet HNO 3 92.2 7.5 0.0 0.0 0.0 0.0 0.3 0.075 0.000 Treatment O 2 Plasma 91.0 8.8 0.0 0.0 0.0 0.0 0.2 0.093 0.000 Treatment UV/O 3 94.5 4.9 0.0 0.0 0.0 0.0 0.5 0.042 0.000 Treatment Amine Grafted 89.2 6.8 3.3 0.0 0.0 0.0 0.7 0.061 0.037 Acrylamide 78.3 14.0 7.8 0.0 0.0 0.0 0.0 0.177 0.100 Grafted PAN based CF 88.9 9.3 1.6 0.0 0.3 0.0 0.0 0.105 0.018 VGCF 95.1 4.9 0.0 0.0 0.0 0.0 0.0 0.052 0.000 Nanosized 91.7 8.2 0.0 0.0 0.0 0.0 0.0 0.089 0.000 Carbon Black
Results and Discussion
XPS
[0114] The effect of surface treatments was investigated by X-ray Photoelectron Spectroscopy (XPS). The results are shown in Table 1. From this data, the acrylamide grafting treatment showed the highest O/C and N/C ratio, suggesting many acrylamide groups were introduced. The amine grafting treatment also showed an increase in N/C ratio, suggesting amine groups were introduced. O 2 plasma treatment showed an increased O/C ratio, suggesting carboxyl groups were introduced. The other two treatments didn't show impressive results.
[0000] Mechanical Properties
[0000] Effect of Surface Treatments on Mechanical Properties
[0115] Graphite nanoplatelets treated by O 2 plasma, amine grafting, and acrylamide grafting were prepared and used as reinforcements to fabricate composites with 1.0, 2.0 and 3.0 vol % of graphite flakes. The flexural strength and modulus of each sample are summarized in FIGS. 29 and 30 .
[0116] The results indicate that the acrylamide grafting was the most effective surface treatment in terms of both strength and modulus enhancements. This is supported by XPS data that showed largest N/C ratio for acrylamide grafting. These data suggest that the amine groups grafted on graphite nanoplatelets improve the compatibility between the graphite nanoplatelets and the matrix and form a bond with the epoxy matrix and improve mechanical properties.
[0000] Comparison with Commercially Available Carbon Materials
[0117] Composites reinforced with PAN based carbon fibers, VGCFs, and nanosize carbon blacks were fabricated. The flexural properties of these composites were measured and compared with those of composites with acrylamide-grafted nanographite. The results are shown in FIGS. 31 and 32 . Here acrylamide grafted nanographite showed the best results in terms of both strength and modulus enhancement. This implies that the acrylamide grafting treatment is a very effective surface treatment for graphite nanoplatelets.
[0000] Coefficient of Thermal Expansion
[0118] Coefficient of thermal expansion (CTE) of composites with 3 vol % of acrylamide grafted nanographite, PAN based carbon fiber, VGCF, or nanosize carbon black were determined by TMA. The results are shown in FIG. 33 . The acrylamide grafted nanographite showed the lowest CTE, indicating good dispersion and strong bonding between the nanoreinforcements and the matrix.
[0000] Tg
[0119] Tg of composites with 3 vol % of acrylamide-grafted nanographite, PAN based carbon fiber, VGCF, or nanosize carbon black were determined by DMTA. The results are shown in FIG. 34 . The acrylamide grafted nanographite showed the slightly higher Tg, but the difference is negligible considering the error margin of the results. Thus these reinforcements didn't affect Tg of epoxy matrix.
[0000] Electrical Property
[0120] The electrical resistivity of the composites with various reinforcement contents were determined. The reinforcements used were PAN based carbon fiber, VGCF, nanosize carbon black, graphite microplate (exfoliated and sonicated, but not milled), and graphite nanoplatelet. The size of each composite sample was about 30×12×8 mm. Each sample was polished and gold was deposited on the surface to insure good electrical contacts. The results are summarized in FIG. 35 . The VGCF, carbon black and graphite microplate percolated at around 2 wt % (1 vol %) while conventional carbon fiber and graphite nanoplatelet showed percolation threshold of about 8 to 9 wt % (5 to 6 vol %). Among the former three reinforcements, graphite microplatelets and carbon blacks produced composites with the lowest resistivity, which reached around 10 −1.5 ohm*cm. Thus, the exfoliated graphite sample also showed excellent electrical property as reinforcement in polymer matrix.
[0121] As shown by this Example, a new nanoplatelet graphite material was developed by expansion (exfoliation) of graphite. An appropriate surface treatment was established for the new material, which produced a nanographite that increased the mechanical properties of an epoxy system better than some commercially available carbon materials at the same volume percentage. In addition, the expanded (exfoliated) graphite material has been shown to percolate at only 1 volume percent. Measurement of the impedance of this material indicates that it could be used to produce polymer matrix composites for new applications such as electrostatic dissipation and EMI shielding.
[0122] The present invention provides a fast and economical method to produce expanded graphite particles, expanded by using RF or microwave energy as the expansion method. It is especially useful in large-scale production and could be a very cost-effective method which would lead to increased use of the exfoliated graphite material.
[0123] The expanded graphite can be compressed or calendared to make sheets with or without resins and/or other additives. These sheets can be used as insulating material. In furnaces or gaskets/sealing materials for internal combustion engines. Also these sheets can be used as electrodes substrates for polymer batteries ( FIG. 38 ) or separator (or fluid flow field plates) for fuel cells ( FIG. 39 ).
[0124] The expanded graphite can be pulverized into platelets with an appropriate grinding method. Platelets with a high aspect ratio can be used as reinforcements in composites, which have high mechanical properties as well as good electrical and thermal conductivity.
[0125] Expanded graphite with an appropriate platelet size can hold and release metal atoms such as lithium, which is suitable as anode material for lithium-ion or lithium-polymer batteries ( FIG. 40 ).
[0126] It is intended that the foregoing description be only illustrative of the present invention and that the present invention be limited only by the hereinafter appended claims. | Graphite nanoplatelets of expanded graphite and composites and products produced therefrom are described. The preferred method of expanding the graphite is by microwaves or other radiofrequency wave treatment of intercalated graphite. The expanded graphite is preferably then crushed to nanometer (substantially all 200 microns or less). The expanded graphite is used in polymer composites. The expanded graphite is particularly useful for batteries, anodes and fuel cells. | 8 |
BACKGROUND OF THE INVENTION
The invention relates to a fin for a heat exchanger, consisting essentially of a matrix of tubes and of fins disposed transversely to the latter, said fins having pass-through elements to receive tubes which are to be joined mechanically, while a first, preferably liquid medium flows through the tubes and the fins are acted on by a second, preferably gaseous medium and are positioned in their fin pitch by integral spacers.
Heat exchanger fins are known from DE-A-37 28 969 and also from DE-C-34 23 746. The power of a heat exchanger is governed, among other factors, by its fin density or so-called fin pitch (number of fins per decimeter), and to ensure uniform quality this predetermined fin density must therefore be accurately maintained, for which reason spacers intended to position the fins on the tubes are provided. Such spacers can be formed either as tabs produced from the fin sheet, which then also serve as turbulence producers, or by bent-over contact surfaces attached at the ends of the pass-through elements of the fins.
In the case of DE-A '969 these contact surfaces are in the form of tongues distributed over the periphery, while in the case of DE-C '746 they are sickle-shaped contact surfaces arranged on the longer sides of the ellipses. In such arrangements it may be a disadvantage that, when the tubes are expanded in relation to the pass-through elements of the fins, complete contact is no longer ensured between the pass-through element and the tube. In addition, the bending-over of the contact surfaces constitutes an additional operation after the formation of the pass-through elements.
SUMMARY OF THE INVENTION
One object of the present invention is to improve a fin of the kind initially defined in such a manner that on the one hand secure spacing apart of the fins and on the other hand good heat transfer between the tube and the fins are achieved, while in addition simple manufacture is possible.
This object is achieved by the fin for a heat exchanger consisting essentially of a matrix of tubes and of fins disposed transversely to the latter, the fins having pass-through elements to receive tubes which are to be joined mechanically, while a first, preferably liquid medium flows through the tubes and the fins are acted on by a second, preferably gaseous medium and are positioned in their fin pitch by integral spacers, wherein the spacers are in the form of noses stamped out of the pass-through elements and distributed over the periphery of the latter.
The novel spacers in the form of noses are partly stamped outwards from the wall of the pass-through element, so that their top edge forms a contact surface for the fin situated above it. Owing to the fact that a plurality of noses are distributed over the periphery of the pass-through element, good, stable support is provided for the next fin. The noses can moreover be produced in a simple manner, because the additional operation of bending-over after the pass-through element has been formed is eliminated. Heat transfer is also ensured, since the noses provided are only partial and thus scarcely restrict the passage of heat between the inner surface of the pass-through element and the outer surface of the tube.
Advantageous developments of the invention are discussed below, while the invention can advantageously be applied both to tubes having circular cross sections and to those having oval or elliptical cross sections. The noses advantageously have approximately the shape of half-pyramids or half-cones, which are divided vertically and widen upwardly, that is to say in the pass-through direction. The bottom tip of a nose of this kind, for example in the form of a half-cone, is advantageously arranged slightly above the plane of the fin, so that a continuous circumferential contact surface of a certain width is maintained between the tube and the pass-through element of the fin, thus ensuring good heat transfer. Since consequently a relatively great height of the pass-through element is not necessary for reasons of heat exchange, the noses are stamped in tabs which have a greater height than the remainder of the pass-through element and which thus dictate the value of the fin pitch or spacing. In the case of oval or elliptical cross sections of the pass-through element it is advisable for the noses to be offset relative to one another for manufacturing reasons--the maximum height of the tabs can be obtained thereby. If the fin spacing is less than the width of the pass-through element, the noses or tabs may also lie opposite one another.
Finally, the invention also relates to a process for producing the pass-through elements provided with the noses, this being carried out in three or four successive operations, the impression of the noses being effected by a punch stroke either in the pass-through direction or oppositely thereto.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred exemplary embodiments of the invention, and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention.
One exemplary embodiment of the invention is described more fully below and illustrated in the drawings, in which:
FIG. 1 shows a fin in plan view,
FIG. 2 shows on a larger scale, in section, the fin shown in FIG. 1,
FIG. 3 shows on a larger scale a pass-through element of the fin shown in FIG. 1,
FIGS. 4a, 4b, 4c and 4d show the individual steps of the process for the production of the pass-through element provided with noses,
FIG. 5 shows on a larger scale a tube provided with fins, and
FIG. 6 shows a detail from FIG. 5: a tube wall together with fin pass-through elements.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows in plan view a fin 1 having pass-through elements 2 which have a flat oval shape and are arranged in two rows offset relative to each other, and gill areas 3 being arranged in each case between the pass-through elements 2. The pass-through elements 2 receive tubes (not shown) which have identical cross sections and which are mechanically expanded relative to the pass-through elements and thus provide the contact required for heat conduction or heat transfer. In the region where no gill areas 3 and no pass-through elements 2 are provided, the fin 1 forms an essentially plane surface 4. Each pass-through element 2 has three noses 8, 9, 10, as will be explained more fully below. The fin 1 is preferably made of aluminum or an aluminum alloy and has a thickness of about 0.1 millimeter.
FIG. 2 shows on a larger scale a section II--II through the fin shown in FIG. 1, so that in particular the inclined gills, known per se, of the gill areas 3 can be seen. They cause a deflection of the air passing over the fins, whereby the transfer of heat on the air side is intensified. In this figure two pass-through elements 2 are shown in side view, it being possible in each case to see three tabs 5, 6, 7 in which the noses 8, 9, 10 are in each case impressed centrally. The tabs 5, 6, 7 are thus offset in relation to one another, that is to say the tabs 5 and 7 lie at the front and the tab 6 lies at the rear, that is to say on the rear longitudinal side of the pass-through element 2.
In FIG. 3 a pass-through element 2 is shown, likewise on a larger scale, namely in a plan view a as a flat oval shape, in which the noses 8, 9, 10 can clearly be seen as bulges having the shape of segments of a circle. A dot-dash line 11 is shown in the interior of the flat oval pass-through element 2 and bounds a stamped-out portion 12, so that the pass-through area 2' can be seen in the plane state before formation of the pass-through element. On the right and left of the pass-through element a, sections c and b of the pass-through element are shown, the illustration b on the left indicating the centrally situated tab 6 provided with the nose 9, while the right-hand illustration c indicates the two tabs 5 and 7 situated eccentrically and provided with the noses 8 and 10. The noses 8, 9, 10 have in each case an outwardly falling top edge 8', 9', 10', which produces the spacing H' (see FIG. 6) of the fins. It can be seen that the height H of the tabs 5, 6, 7 exceeds the height h of the remainder of the pass-through element, although a continuous region 13 is obtained which has the height h and bears all around against the outside circumference of the tube, so that a closed heat transfer surface is formed between the fin and the tube, this surface moreover also maintaining the elastic stress necessary after the expansion.
As already indicated by the line 11 in FIG. 3, FIGS. 4a, 4b, 4d and 4d now show the individual steps of the process for the production of the pass-through element according to the invention. FIG. 4a shows the fin sheet 20 after the punching, that is to say a strip 24 having rounded ends 22, 23 is cut out of the plane fin sheet 20 by means of a suitable perforating punch, while offset tabs 25, 26, 27 are cut free. As shown in FIG. 4b, in the following step of the process, by means of a stamping punch, noses 28, 29, 30 are impressed in these tabs 25, 26, 27, the noses having a pyramidal shape, that is to say being formed of two plane triangular surfaces inclined relative to one another. In the next step of the process, as illustrated in FIG. 4c, the pass-through element 21 is drawn in, that is to say only "tilted", against a die 31 having a correspondingly oval-shaped bending edge, so that the noses come to lie straight against the inner wall of the die 31 but the remainder of the pass-through element 21 still has a conical shape In FIG. 4c the tabs 25' 26' 27' are thus shown shortened in relation to FIG. 4b.
In the last step of the process, shown in FIG. 4d, the pass-through element is completed, that is to say the collar 21 is formed by means of a punch (not shown), so that it acquires a cylindrical shape (having a flat oval cross section) and the noses 25", 26", 27" project outwards as triangles, which is made possible by means of corresponding cutouts 32, 33, 34 in the die. By the process described the pass-through elements in which the noses are formed can be produced in a simple manner, quickly and with uniform quality.
Another process is also possible, in which the steps of the process according to FIGS. 4b and 4c are carried out only at the end, namely with the aid of a stamping punch which is introduced from above into the completed pass-through element.
FIG. 5 shows on a larger scale a section of a tube 40 onto which fins 41 to 45 have been "threaded". This tube 40 is part of a heat exchanger (not further shown), the shape and pitch of whose tubes and the formation of whose fins could correspond to FIG. 1. As already mentioned, the fins 41 to 45 are joined mechanically to the tube 40, that is to say are connected by a metallic interference fit through expansion of the tube 40 in relation to the pass-through elements of the fins. No soldering or adhesive bonding, that is to say joining of materials, is therefore required.
FIG. 6 shows on a larger scale a part of FIG. 5, namely a part of the tube wall 40 and three fin portions 41, 42, 43, the pass-through elements 46, 47, 48 of which, having the height h, lie closely circumferentially against the tube 40, while their noses 49, 50, 51 project from the outside wall of the tube 40 and, by means of their top edge, fix the spacing H' of the fins 41, 42, 43. The fin spacing H' is slightly smaller than the height H of the tabs (see FIGS. 3b and 3c), because the pass-through element of the fin has a transition radius on which the noses are supported. Both FIGS. 5 and 6 show the completed tube and fin arrangement, that is to say in the completely mechanically connected state of the tube and pass-through elements of the fins after the expansion of the tube 40.
Fins of this kind, which are connected to a nest of parallel tubes which in turn are received in tube plates of collecting tanks, are used in particular in heat exchangers for motor vehicles, for example as radiators for the air cooling of engine coolants or as heat exchangers for heating systems. In such cases flat oval tube cross sections have an advantageous effect in respect of the pressure drop on the air side.
Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details, and representative devices, shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents. | The fin for a heat exchanger which consists essentially of a matrix of tubes and of fins disposed transversely to the latter, the fin having pass-through elements to receive tubes which are to be joined mechanically, while a first, preferably liquid medium flows through the tubes and the fin is acted on by a second, preferably gaseous medium. Multiple fins are positioned in their fin pitch by integral spacers, wherein the spacers are in the form of noses stamped out of the pass-through elements and distributed over the periphery of the latter. | 8 |
PRIORITY
[0001] This application claims the benefit of provisional application No. 61/584,119, that was filed on Jan. 6, 2012 by the inventor Stan Greberis.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to methods and apparatus for handling waste water and, more particularly, to a waste water diffuser that may prevent waste water from causing soil erosion and/or being discharged into a public storm water systems and/or sanitary sewers and/or waterways.
[0003] When a person faces a task of getting rid of excess, unwanted water, for example water from a basement sump or water from a pool, the water is typically carried by a hose or pipe to be released. Often, a large release of water may cause soil erosion. To avoid this type of erosion, a person may opt to disburse the water into a public storm water system down their driveway into a street drain and/or a sanitary sewer system. This type of release may be harmful to the environment and may be illegal in many jurisdictions, especially in the case of pool water, which may contain certain chemicals.
[0004] As can be seen, there is a need for an apparatus for diffusing and distributing waste water to avoid erosion and the delivery of waste water into inappropriate channels.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a schematic view of a water distribution system according to an exemplary embodiment of the present invention.
[0006] FIG. 2 is a schematic view of the water distribution system according to another exemplary embodiment of the present invention.
[0007] FIG. 3 is a detailed view of the interior of the water distribution system.
[0008] FIG. 4 is another detailed view of the interior of the water distribution system.
[0009] FIG. 5 is another detailed view of the interior of the water distribution system.
[0010] FIG. 6 is another detailed view of the interior of the water distribution system.
[0011] FIG. 7 is another detailed view of the interior of the water distribution system.
[0012] FIG. 8 is a detailed view of the flow of water through the water distribution system.
DETAILED DESCRIPTION OF THE INVENTION
[0013] The following detailed description is of the best currently contemplated modes of carrying out exemplary embodiments of the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims.
[0014] Broadly, an embodiment of the present invention provides a water distribution system that may discharge waste water into the surrounding soil without creating soil erosion. The water distribution system may create a fountain-like or sprinkler-like distribution of waste water over a large ground surface area, permitting the water to soak into the soil rather than run over the top of the soil, which leads to erosion.
[0015] Referring to FIG. 1 , a water distribution system may be a fountain-type system where tubing may carry water from a pump, such as a pool water pump, to a series of perforations in the pipe which distribute the water from the tubing in a fountain-like distribution. The perforations may be distributed along the tubing such that there is little or no overlap from the spray from one of the perforations to the spray of an adjacent perforation.
[0016] Referring to FIGS. 1 and 2 , the water distribution system comprises a pool pump or filter 15 connected to a supply tube 10 . The supply tube 10 is connected to a distribution tube 1 . On the distribution tube 1 is a plurality of distribution openings 5 . FIG. 1 shows the distribution openings 5 as holes. FIG. 2 shows the distribution openings 5 as sprinklers.
[0017] Referring to FIG. 3 , FIG. 3 shows a top view of the water distribution system with supply tube 10 connected to and entering distribution tube 1 . Supply tube 10 is then inside the distribution lumen 3 of the distribution tube 1 , forming inner tube 2 . The distribution tube 1 also has distribution openings 5 . The water 6 travels in the supply lumen 4 of the supply tube 10 , through inner tube 2 , then into the distribution lumen 3 of the distribution tube 1 . The water 6 is then distributed out of the system by the distribution openings 5 .
[0018] Referring to FIG. 4 , FIG. 4 is a detailed drawing of the junction between the supply tube 10 and the distribution tube 1 . At the point where supply tube 10 meets distribution tube 1 , the two tubes are joined and reinforced by a collar or funnel 9 . The funnel 9 creates an opening into the inner tube 2 , which is itself an extension of the supply tube 10 . The inner tube 2 contains a filter 7 in the supply lumen of the supply tube 10 in the part of the supply tube 10 that is also the inner tube 2 . In the preferred embodiment, the filter 7 comprises carbon particles. These filter 7 particles are held in place by a mesh 8 . Thus the water 6 can flow from the supply tube 10 , past the funnel 9 , into the inner tube 2 , which is in turn in the distribution lumen 3 of the distribution tube 1 .
[0019] Referring to FIG. 5 , FIG. 5 is a detailed drawing of the outlet 11 between the inner tube 2 and the distribution tube 1 . Distribution tube 1 has distribution openings 5 . Water 6 travels through supply lumen 4 and crosses outlet 11 to enter distribution lumen 3 and then exit distribution tube 1 through distribution openings 5 .
[0020] Referring to FIG. 6 , FIG. 6 is a cross section of the water distribution system. Distribution tube 1 has distribution lumen 3 and distribution opening 5 . Within the distribution lumen 3 is inner tube 2 . Inner tube 2 contains supply lumen 4 , which is a continuation of the supply tube 10 , not pictured. Inner tube 2 has outlet 11 . Outlet 11 comprises a plurality of outlet openings 12 . Filter 7 is located in distribution lumen 3 . Distribution tube 1 also has a drain 13 . In this version, the position of outlet 11 and filter 7 is at the bottom of distribution lumen 3 , so that water 6 must travel down through outlet 11 and filter 7 and then up to distribution openings 5 .
[0021] Referring to FIG. 7 , FIG. 7 is a cross section of the water distribution system. Distribution tube 1 has distribution lumen 3 and distribution opening 5 . Within the distribution lumen 3 is inner tube 2 . Inner tube 2 contains supply lumen 4 , which is a continuation of the supply tube 10 , not pictured. Inner tube 2 has outlet 11 . Outlet 11 comprises a plurality of outlet openings 12 . Filter 7 is located in distribution lumen 3 . Filter 7 is held in place by flanges 14 . Distribution tube 1 also has a drain 13 . In this version, the position of outlet 11 and filter 7 is at the top of distribution lumen 3 , so that water 6 must travel up through outlet 11 and filter 7 and then up to distribution openings 5 .
[0022] Referring to FIG. 8 , FIG. 8 is a detailed view of the flow of water through the water distribution system. FIG. 8 compares the present invention to a hypothetical standard arrangement and shows the flow of water through each system. Image 2 and 3 of the FIG. 8 show a side and front view of the flow of water through the water distribution system.
[0023] While FIG. 1 shows a rectangular distribution area, the tubing may be arranged in any number of patterns. The size of the perforations may be determined through a variety of factors, such as the type of soil, the amount of water typically distributed through the system on a single time, the pressure of the water within the tubing during the distribution process, and the like. Typically, the number of perforations and the size thereof will be adequate to distribute/diffuse the waste water while permitting the water to be absorbed into the soil, without causing soil erosion. In the preferred embodiment, the distribution tube will be circular in shape. The circular shape is preferable because it promotes even distribution of the water, and is ascetically pleasing. Other embodiments are also functional and may be advantageous in cases where the desired distribution of water is uneven. Other embodiments of the water distribution system can also be a be a three-dimensional shape, such as a box, pyramid, ball or any other shape that will capture the water and then allow for the escape through the upper and side perforations and/or attachments, such as sprinkler heads, while including a modest amount of perforations on the bottom to allow the unit to self drain. Each of these three-dimensional versions can have a modified bottom so that the water distribution system can be placed stability on a surface, such as making the bottom of a ball flat.
[0024] The tubing may be typical plumbing tubing and may include PVC, metal, or other materials. For example, the tubing leading from the waste water source (such as a pool), may be collapsible flexible drain tubing, permitting easy storage thereof. The distribution portion of the tubing may be the same or different material as the tubing connecting the water source (pool) to the distribution portion. In some embodiments, the distribution portion may be rigid tubing, which may ensure alignment of the perforations, or distribution openings 5 , perpendicular to the ground.
[0025] Referring to FIG. 2 , in place of the distribution opening 5 , sprinkler heads may be fluidly connected to the distribution tube 1 to permit the waste water 6 to be distributed over a larger surface area.
[0026] In some embodiments, the system of the present invention may be supplied as a kit. The kit may include tubing to connect the distribution system to the pump and distribution tubing having a water distributing means, such as perforations or sprinkler heads, as described above. The kit may supply the distribution tubing in various pieces and may include a variety of connectors so that a user may create their own pattern for water distribution. For example, the kit may include various pieces of perforated pipe along with elbows, tees, and the like. The fittings may be quick release fittings, permitting the user to quickly assemble and disassembly the system of the present invention.
[0027] The filter 7 may be made of any filtering material, including foams, mesh, ceramics, and absorbent particles. In the preferred embodiment, the filter 7 is made of carbon particles that are larger than any exit to the inner tube 2 . In some cases the carbon particles will be held into place by a mesh 8 or a flange 14 .
[0028] In some embodiments, the distribution tube 1 has one or more drains 13 . The drains 13 are placed on the bottom portion of the distribution tube 1 . The purpose of the drains 13 is to drain any water trapped or remaining in the distribution tube 1 so that the distribution tube 1 is dry for storage. Furthermore, standing water is a know vector for insect larvae growth. The drains 13 will allow the operator to drain the distribution tube 1 to reduce the growth of insect larvae.
[0029] In some embodiments, the filter 7 is external to the distribution tube 1 . In this case, the filter 7 is placed before or within supply tube 10 and before the junction between supply tube 10 and distribution tube 1 . In other embodiments, the filter 7 is not included in the apparatus. In this embodiment, the water 6 will pass through the distribution tube 1 and inner tube 2 without being filtered.
[0030] The preferred embodiment envisions the use of the wastewater drainage system to distribute unneeded pool water. The wastewater drainage system can also be used to drain rain and other runoff water. The wastewater drainage system can be attached to a sink, tube, or tank drain. The wastewater drainage system can be attached to a gutter or downspout. The system can be used in landscaping and construction site applications.
[0031] It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims. | This application claims a system for the distribution of waste water. The invention allows water to drain from a source into the invention, where the water is distributed and diffused through a collection of outlets. Thus a large amount of water can be distributed over a large area so that the environment can more easily absorb the water and the flow of water does not cause erosion. The preferred embodiment of the invention includes one or more filters to remove substances from the water before distribution. | 4 |
FIELD OF THE INVENTION
The present invention relates generally to carriages or strollers for carrying infant children, and more particularly to a stroller which is adapted for carrying infants while the user engages in jogging or running activities and which may be rapidly disassembled into segments for stowage.
BACKGROUND OF THE INVENTION
As is well known, carriages or strollers utilized to carry infants typically comprise a basket-like seat disposed in a frame supported by three or four wheels. Generally, these devices are designed to be pushed along at no more than a walking speed on relatively smooth surfaces such as pavement, and are therefore fitted with small diameter wheels and frame members having strength and resilience properties which limit their application to these conditions. For those who have infant children it is oftentimes desirable, such as for purposes of convenience, to take the infant along while engaging in running or jogging activities. As such, there exists a need for an infant stroller adapted to roll at jogging or running speeds on a variety of running surfaces typically utilized by joggers, such as unpaved trails, lawn areas and beaches. In recognition of this need, it is heretofore known in the prior art to provide a stroller with a lightweight frame supported by larger diameter wheels fitted with pneumatic tires as depicted in U.S. Pat. No. Des. 297,525 issued to Bacchler. It has been found, however, that while such a device is adapted for the jogging conditions described above, it is limited in utility in that it is too large, even when made collapsible, to fit into most automobile trunks (when folded or collapsed these devices extend into a more elongate configuration which is too long to fit within an automobile trunk). This lack of stowability for transport particularly reduces the utility of such devices in that it is often desirable to take them along for use at destinations such as camping sites or otherwise necessary to travel over distances by automobile to reach a desired jogging location such as a beach or trail.
In view of the above, there exists a substantial need in the art for an infant stroller device which is adapted both for use in the jogging applications described above and for compact stowage as in an automobile trunk.
SUMMARY OF THE INVENTION
The present invention specifically addresses and satisfies the above referenced need in the art by providing a stroller device which can be rapidly disassembled into segments as for stowage and reassembled for use without the need for tools. The segments fit readily into relatively small stowage areas such as automobile trunks and room closets. The strength and resilience of the frame and wheels of the present invention make it suitable for use while engaging in jogging activities on a variety of surfaces.
DESCRIPTION OF THE DRAWINGS
These and other features of the present invention will become more apparent upon reference to the drawings wherein:
FIG. 1 is a perspective view of the preferred embodiment of the present invention;
FIG. 2 is a detail perspective view showing the stroller seat portion of the preferred embodiment of the present invention;
FIG. 3 is an exploded perspective view of the segments comprising the preferred embodiment of the present invention;
FIG. 4 is a detail perspective view illustrating the interconnected construction of the frame segments in the preferred embodiment of the present invention; and
FIG. 5 is a detail perspective view taken about aspect lines 5--5 of FIG. 1 illustrating the interconnection of the front fork and infant support frame segments of the preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, there is shown the preferred embodiment of the jogging stroller device formed in accordance with the present invention, composed generally of a plurality of frame segments which in the preferred embodiment include an infant support segment 10, a front fork segment 12, a first rear axle segment 14 and a second rear axle segment 16, which are interconnectable without the need for tools as by way of a releasable fasteners to permit the rapid assembly and disassembly of the stroller device. Each segment 10, 12, 14, 16 is preferrably formed, in part, from tubular metal frame members which generally may be connected together as by way of weldments or other rigid connection means.
Referring more particularly to FIGS. 2 and 3, it can be seen that the infant support segment 10 includes an upper support member 22 which has a forwardly downward inclined orientation when the present invention is assembled, and which itself further comprises a handlebar portion 24 with handgrips 25 and two elongate lateral portions 26, each having a generally S-shaped curve located centrally along the length thereof to form arm rest portions 28. A stroller seat 30, typically formed from a fabric material, is affixed to the upper support member 22 by folding over the peripheral sides thereof forming two lateral channels through which lateral portions 26 are slidingly inserted. The infant support segment 10 further includes a generally U-shaped vertically oriented lower support member 32, which is pivotally connected at its two upper distal ends to the arm rest portions 28 of upper support member 22 as by way of pin and clevis connections, 34 with the pin portions thereof preferrably consisting of bolts threadingly cooperating with lock nuts. A seat post portion 36 extends vertically downward from the mid-point of the lower horizontal portion of lower support member 32.
The first rear axle segment 14 comprises a left rear axle portion 38, connected rotatably at one end to a left rear wheel 40, and to a rear spine portion 42 at a distance proximal from the other end so that rear spine member 42 extends horizontally forward from the mid-point of the rear axle assembly when the frame segments are interconnected. A seat post receiving portion 44 extends normally and vertically from rear spine portion 42.
The second rear axle segment 16 consists of a right rear axle portion 46, rotatably connected at one end to a right rear wheel 48.
The front fork segment 12 includes a fork portion 50 rotatably connected to a front wheel 52, and having a forward spine portion 54 positioned to extend horizontally rearward for connecting together segments 12 and 14. A pair of post portions 56 extend from the upper side of the fork portion 50 and are positioned to align coaxially with the forward ends 58 of upper support member 26 for insertion therewithin when segments 10 and 12 are connected. The front fork segment 12 may also include a braking means, such as a caliper-type rim brake 60 as is typically utilized in bicycle applications, operated as by way of a handbrake lever 62 mounted on the handlebar portion 24 of infant support segment 10 via an actuator cable 64 (only partially shown). The wheels 40, 48, 52 preferrably consist of wire spoke wheels fitted with pneumatic tires.
The present invention includes means for connecting the frame segments together, which in the preferred embodiment comprises forming tubular couplings, wherein right rear axle portion 46, forward spine portion 54, post portions 56 and seat post 36 are sized to form insert portions, i.e. they are diametrically sized to be slidingly received or inserted within the interiors of receiving portions 38, 42, 58 and 44 respectively, to connect together the corresponding frame segments. The present invention further includes retaining means for releasably retaining the segments in their connected configuration, which in the preferred embodiment comprises button/aperture fasteners wherein a retaining button positioned on the outer lateral side of each insert portion is normally spring biased or otherwise maintained to protrude outwardly but which may be depressed inwardly as by way of finger pressure until flush with the insert portion lateral side. As such, the retaining button can be depressed to permit the insert portion to slide unobstructed into the interior of the corresponding receiving portion until the retaining button engages a complementary aperture on the lateral side of the receiving portion i.e. the retaining button aligns with and biases outwardly through the aperture wherein the lateral sides of the retaining button abut the aperture sides and thereby prevent the insert portion from sliding further in either direction within the interior of the receiving portion.
To interconnect the segments of the preferred embodiment of the present invention, second rear axle segment 16 is connected to first rear axle segment 14 by inserting right rear axle portion 46 into the free end of left rear axle portion 38 until retaining button 66 engages aperture 66' as shown in FIG. 4. Front fork segment 12 is then connected to first rear axle segment 14 by inserting forward spine portion 54 into the free end of rear spine porton 42 until retaining button 68 engages first position aperture 68A, thus forming a platform structure supported by wheels 40, 48, 52. Infant support segment 10 is then connected to segments 12 and 14 wherein post portions 56 are inserted into the forward ends 58 of support member lateral portions 26 and seat post 36 is inserted into the upper end of seat post receiving portion 44 until retaining button 70 engages aperture 70' as shown in FIGS. 5 and 4 respectively (the angle of lower support member 32 can be adjusted via pivotal connections 34 to facilitate to the alignment of portions 36 and 44). With the segments assembled in this first position, retaining button 68 is then disengaged from first position aperture 68A by depressing it inwardly back therethrough and then inserting forward spine portion 54 further into rear spine portion 42 until retaining button 68 engages second position aperture 68B, causing the frame of the present invention to compress and thereby form a rigid structure.
The frame segments 10, 12, 14, and 16 may be disconnected in reverse manner as for stowage by depressing the retaining button at each connection inwardly back through its receiving aperture to disengage the corresponding insert and receiving portions which are then slidingly pulled apart.
From the above it will be recognized that the segments comprising the jogging stroller of the present invention can be rapidly interconnected and subsequently disconnected without the need for any tools whatsoever. As such, the present invention can be rapidly disassembled and the segments arranged into a compact configuration permitting them to be stowed in places where space is limited, such as a room closet, an automobile trunk, a vehicle luggage rack or other form of vehicle stowage area. When stowage space is even more limited, the separate segments can be dividedly stowed in different locations within a stowage compartment or even within different compartments such as an automobile trunk and rear passenger area. It will be further recognized that the disconnected infant support segment 10 can be made even more compact for stowage by folding lower support member 32 toward upper support member 22 via the pivotal connections 34.
Although the present invention has been described herein with reference to specific design configurations, methods of construction and materials, those skilled in the art will recognize that modifications to the same can be made without departing from the spirit of the present invention and such modifications are contemplated herein. | A stroller device for carrying infant children which is particularly adapted to convey an infant while its user engages in jogging or running activities while being formed of a plurality of releasably interconnectable segments which permit the stroller to be rapidly disassembled without the need for tools, into a compact configuration for storage. The segments can be likewise rapidly reconnected, also without the need for tools, for use in the above applications. | 1 |
BACKGROUND OF THE INVENTION
The present invention relates to a pneumatic transmission apparatus for carrying materials such as small resin molds, metal parts or powdered material.
Two basic types of transmission apparatus for carrying materials such as resin molds, metal parts, or powdered material, are known in the prior art. These are a pressurized air introduction type and air suction type.
In the former apparatus, a pressurized air supply is connected to an inlet of a tubular transmission passage. A flow of air produced within the tubular transmission passage by the pressurized air supply, carries materials from the inlet through the transmission passage to an outlet.
The latter apparatus has an overall structure similar to the former. An air suction means is connected to the outlet of the tubular transmission passage. The applied suction produces a flow of air within the tubular transmission passage, which carries materials from the inlet through the passage to the outlet.
In both types of device, materials are transmitted by straight air flow in the tubular transmission passage. As a consequence, stalled air flow may occur within the transmission passage. The transmission distance is limited, since long distance transmission increases the likelihood of stalled flow. In addition, regulation of travel speed is difficult and the prior art apparatus is not suitable for low speed transmission of materials.
When the tubular transmission passage contains a corner or sharp bend, parts being transmitted may collide with each other, or impact or rub against inner surface of the tubular transmission passage, thereby causing damage to the parts, and wear of the tubular transmission passage. Therefore, the prior art apparatus is not suitable for transmission of fragile materials which would be damaged by even minor impact.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a pneumatic transmission apparatus for carrying materials such as small resin molds, metal parts or powdered material, which overcomes the drawbacks of the prior art.
It is a further object of the invention to provide a pneumatic transmission apparatus which permits transmission over a long distance.
It is a still further object of the invention to provide a pneumatic transmission apparatus wherein the transmission speed is easily regulated.
It is a still further object of the invention to provide a pneumatic transmission apparatus wherein parts being transmitted do not collide with each other, or impact or rub against the inner surface of the tubular transmission passage.
Briefly stated, there is provided a spiral flow connector which imparts a spiral flow of air to urge parts being transmitted toward a central axis to avoid contact with the walls of the transmission passages of a pneumatic transmission apparatus. The invention is especially useful for preventing damage to fragile parts such as small resin molds, metal parts or powdered material. The spiral air flow prevents air stalling in the transmission passages.
In accordance with these and other objects of the invention, there is provided a pneumatic transmission apparatus which comprises: a first and second tubular transmission passage, means for interconnecting the first and the second tubular transmission passage, the means for interconnecting including means for introducing air moving in a direction into the means for interconnecting, the means for introducing air including means for generating a spiral air flow moving in the direction within said second tubular transmission passage.
According to feature of the invention, there is further provided a pneumatic transmission apparatus which comprises: a first and a second tubular transmission passage, a connecter including means for joining the first tubular transmission passage with the second tubular transmission passage, the connector including a lower stream member and an upper stream member, an outlet at a downstream side of the lower stream member, an inlet at an upstream side of the upper stream member, the lower and upper stream members including means for joining an upstream side of the lower stream member to a downstream side of the upper stream member, the upstream member and the downstream member forming a continuous passage within the connector, connecting the inlet with the outlet, a port for receiving a supply of pressurized air, the port being disposed between the inlet and the outlet, an annular passage in communication with the port within the connector, the annular passage disposed coaxially about the continuous passage, the annular passage defined by boundaries of both the lower and upper stream members, the continuous passage including a lower stream passage, a plurality of jet passes providing communication between the annular passage and the lower stream passage, the lower stream passage being disposed between discharge openings of the plurality of jet passes and the outlet, the plurality of jet passes each having a discharge angle facing at least partially downstream, each discharge angle having a directional component tangential to an inner circumferential wall of the lower stream passage, whereby air, discharged into the lower stream passage from the plurality of jet passes, produces a spiral air flow exiting the outlet and a suction at the inlet.
According to a still further feature of the invention, there is still further provided a connector for use in a pneumatic transmission apparatus, which comprises: the connector having an inlet disposed at an upstream side and an outlet disposed at a downstream side, a continuous passage connecting the inlet with the outlet, a port for receiving a supply of pressurized air, the port being disposed between the inlet and the outlet, an annular passage in communication with the port within the connector, the annular passage disposed coaxially about the continuous passage, the continuous passage including a lower stream passage, a plurality of jet passes providing communication between the annular passage and the lower stream passage, the lower stream passage being disposed between discharge openings of the plurality of jet passes and the outlet, the plurality of jet passes each having a discharge angle facing at least partially downstream, each of the discharge angles having a directional component tangential to an inner circumferential wall of the lower stream passage, whereby air, discharged into the lower stream passage from the plurality of jet passes, produces a spiral air flow exiting the outlet and a suction at the inlet.
According to a still further feature of the invention, there is still further provided a connector for a pneumatic transmission apparatus which comprises: a central passage, inlet means for admitting a material to be transmitted to the central passage, outlet means for discharging said material from the central passage, means for supplying a flow of a gas into the central passage, and the means for supplying including means for producing a spiral flow of the gas directed toward the outlet means, whereby material entering the inlet means is urged through the connector and in a spiral path through the outlet means.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram of a pneumatic transmission apparatus according to an embodiment of the present invention.
FIG. 2 is a sectional view of an embodiment of the connector of FIG. 1.
FIG. 3 is a left side view of FIG. 2.
FIG. 4 is a view taken on line IV--IV of FIG. 2.
FIG. 5 is a right side view of FIG. 2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown, generally at 10, a pneumatic transmission apparatus having first tubular transmission passage 1, a second tubular transmission passage 2, a connector 3 and a high pressure air supply line 4. Air flows through pneumatic transmission apparatus 10 in a direction as indicated by arrows D, as will be described in further detail below.
First tubular transmission passage 1 and second tubular transmission passage 2 are made of any suitable material such as, for example, air-tight, flexible vinyl hose. First tubular transmission passage 1 is connected to an inlet 30 of connector 3 and second tubular transmission passage 2 is connected to an outlet 31 of connector 3.
As shown in FIG. 2 to FIG. 5, connector 3 consists of an upper stream member 32 and a lower stream member 33. Upper stream member 32 has inlet 30 disposed at the upstream side and a male screw 32a on the downstream side. Lower stream member 33 is securely connected to upper stream member 32 by a female screw 33a which engages male screw 32a. Lower stream member has outlet 31 disposed at its downstream side.
Connector 3 is formed with a spiral flow generating passage 34. Spiral flow generating passage 34 consists of an annular passage 34A and a plurality of jet passes 34B. The boundaries of annular passage 34A are defined by the combination of an annular groove 32A formed in the outer periphery of upper stream member 32 and a circumferential wall 33A of lower stream member 33. Jet passes 34B penetrate from annular groove 32A, continue in a downstream direction, and open into a lower stream passage 35 in lower stream member 33. Jet passes 34B, having small diameters, are disposed at skewed discharge angles, each having a directional component tangent to the inner circumference and transverse to an axis of lower stream passage 35, as shown in FIG. 4. Lower stream passage 35 in lower stream member 33 has a conically tapered entrance portion 37 disposed at the upstream side of lower stream member 33. Air passing through jet passes 34B is directed by conically tapered entrance portion 37 into a downstream portion of lower stream passage 35.
As shown in FIG. 1, high pressure air supply line 4 consists of a high pressure air supply source (air compressor) 40, a high pressure hose 42, a pressure-flow regulating device 41 and a high pressure supply hose 43. The outlet of high pressure supply hose 43 is connected to port 36 by a conventional connector.
Operation of pneumatic transmission apparatus 10 is as follows. The pressure and quantity of air flow generated by high pressure air supply source 40 is set to a predetermined value by pressure-flow regulating device 41. The regulated high pressure air is then supplied to annular passage 34A of connector 3 through high pressure supply hose 43. The supplied high pressure air flows through jet passes 34B, and is discharged into lower stream passage 35. The skewed discharge angles of jet passes 34B are disposed tangentially to the inner circumference of lower stream passage 35, and in a direction towards outlet 31. This creates a high speed, spiral flow of air, which flows in a direction towards outlet 31. The high pressure spiral flow of air continues to flow through second tubular transmission passage 2, to an outlet 2A, where it exits.
The high pressure spiral air flow generated in second tubular transmission passage 2, creates a lowered pressure in first tubular transmission passage 1. As a result, air is sucked into an inlet 1A of first tubular transmission passage 1. Materials (not shown) introduced into inlet 1A are thereby transmitted to connector 3 via the air flow produced by the generated suction in first tubular transmission passage 1.
Materials transmitted toward connector 3 are then transmitted to outlet 2A of second tubular transmission passage 2 via the high pressure air spiral flow produced by spiral flow generating passage 34.
Materials introduced into pneumatic transmission apparatus 10, are spirally transmitted near the axis of second tubular passage 2. Consequently, the stalling phenomenon does not occur, thereby permitting longer transmission distance.
The level of pressure supplied by high pressure air supply line 4 is determined by the size and mass of the materials introduced into pneumatic transmission apparatus 10.
In addition, transmission speed in the second tubular transmission passage 2 may be easily regulated by controlling the pressure and flow-rate of the high pressure air. Pressure-flow regulating device 41 in high pressure air supply line 4 allows such simple and precise regulation.
The transmission speed increases with higher pressure. As the air pressure increases, the rate of the axial component compared with the spiral component of the high pressure air spiral flow also increases. The lead (lead of thread) of the high pressure air spiral flow becomes large, resulting in a high transmission speed.
Conversely, decreasing the supply air pressure reduces the transmission speed. Because the rate of the axial component compared with the spiral component of the high pressure air spiral flow decreases with reduced pressure, the lead of the high pressure air spiral flow becomes small. This results in a low transmission speed.
Since the transmission speed is easily regulated as described above, the present invention can be applied to the transmission of materials requiring low speed. This allows a wider range of transmissible materials.
As previously mentioned, the materials are transmitted spirally near the axis of the second tubular transmission passage 2 by the high pressure air spiral flow. If the second tubular transmission passage 2 contains a corner or sharp bend, a collision of materials with the second tubular transmission passage 2, or the transmitted materials with one another, is avoided. Since damage to more fragile materials is prevented, this too permits a wider range of materials to be transmitted. Also, by reducing internal abrasion, the useful life of second tubular transmission passage 2 is extended.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims. | A spiral flow connector imparts a spiral flow of air to urge parts being transmitted toward a central axis to avoid contact with the walls of the transmission passages of a pneumatic transmission apparatus. The invention is especially useful for preventing damage to fragile parts such as small resin molds, metal parts or powdered material. The spiral air flow prevents air stalling in the transmission passages. | 1 |
BACKGROUND OF THE INVENTION
[0001] This invention relates to a holding device for holding one cam shaft of an engine relative to another cam shaft of an engine to prevent rotation of the cam shafts.
[0002] The holding device of the invention has been devised for restraining cam shafts of a double overhead cam shaft internal combustion engine against rotation. Where an internal combustion engine has four cam shafts, two holding devices according to the invention may be employed to prevent the cam shafts of each pair of cam shafts from rotating relative to the other cam shaft of that pair.
[0003] In internal combustion engines a toothed timing belt is trained around toothed pulleys or sprockets mounted to ends of the cam shafts. These belts require periodic replacement and to ensure that the timing relationship between the cam shafts and crank shaft of the engine is not lost, the cam shafts may need to be held against rotation relative to one another while the belt is removed and a new timing belt is fitted.
[0004] Tools for effecting such immobilization of cam shafts are available. Often such tools are specifically designed for a particular type of engine and are not usable for other engines. This requires a selection of tools to be stocked in order to enable workshops to perform replacement of timing belts for a variety of different engines types.
[0005] U.S. Pat. No. 6,332,256 discloses a holding device intended to be adjustable so that it may suit engines of a variety of types. The holding device of U.S. Pat. No. 6,332,256 is particularly complex in its construction and has a plurality of holding members arranged in pairs with at least three of the holding members being adjustable relative to one another and in one embodiment four clamps are present in order to allow the holding members to be locked relative to one another in a desired orientation.
[0006] The arrangement of U.S. Pat. No. 6,332,256, whilst being adjustable, is of a particularly complex construction and relatively difficult to operate.
SUMMARY OF THE INVENTION
[0007] It is an objection of the invention to provide a holding device which at least minimises the difficulties mentioned above.
[0008] According to one aspect, the invention provides a holding device for holding two rotary elements against rotation relative to one another and having a connecting member, a first unitary holding member with spaced projections for engagement with one of the rotary elements at spaced locations on the one rotary element, a first clamp for clamping the first holding member relative to the connecting member, a second unitary holding member with spaced projections for engagement with the other of the rotary elements at spaced locations on the other rotary element, and a second clamp for clamping the second holding member relative to the connecting member, the holding members being clampable relative to the connecting member at selected distances from one another.
[0009] Preferably, the second holding member is moveable along the connecting member and clampable by the second clamp relative to the connecting member at selected locations along the connecting member.
[0010] The connecting member may consist of an elongated rail relative to which the holding members are clamped by the respective clamps. The elongated connecting rail may comprise an elongated slotted rail with the second clamp being receivable by the slot in the slotted rail to allow the second holding member to be clamped relative to the rail at selected positions along the length of the slot.
[0011] The connecting member may have one continuous slot formed along its length and each of the holding members may be clamped to the connecting member by a clamp which extends through the slot. In an alternative arrangement, the connecting member has an aperture extending through it for receiving one of the clamps and relative to which the holding member may be clamped to the connecting member. A slot may be present relative to which the other clamp may clamp the other holding member relative to the connecting member.
[0012] As previously mentioned, the holding device for the invention includes two clamps for clamping the holding members relative to the connecting member. Each clamp may consist of a clamping fastener adapted to extend through the connecting member. Preferably, each clamping fastener consists of a clamping screw having a head at one end and a threaded shank extending from the head adapted to engage with the holding member whereby rotation of the head may clamp the holding member relative to the connecting member.
[0013] Each holding member may comprise a holding shoe having spaced projections for engagement with a respective rotary element. Preferably, the holding shoe has a body and two spaced flanges from which the projections may extend. Each of the projections is adapted to be received within a space between adjacent teeth or cogs on a rotary element such as a timing gear located on the end of an engine cam shaft.
[0014] In a particular preferred form, each projection has a shoulder or step part way along its height such that a free end of its projection is narrower in transverse cross-section than a base of each projection. By having projections of this particular shape, the device of the invention is more readily suited to use with a variety of different rotary elements. It should be appreciated however that it is not essential to the invention that the projections have this stepped profile.
[0015] It is preferred that a washer be positioned between each of the holding members and the connecting member such that the washer is clamped between the connecting member and the holding member when the holding member is clamped to the connecting member. It is preferable that the holding member be clamped to the connecting member to prevent undesired relative rotation of the holding member with respect to the connecting member. To this end, one or both of the facing surfaces of the holding member and the connecting member may be provided with a friction enhancing surface. In one particular embodiment both facing surfaces are provided with friction enhancing raised dimples.
BRIEF DESCRIPTION OF THE INVENTION
[0016] The invention will now be described by way of example with reference to the accompany drawings in which:
[0017] FIG. 1 is an exploded perspective view of a holding device according to a preferred embodiment of the invention;
[0018] FIG. 2 is an assembled view of the holding device of FIG. 1 with the holding device shown in one configuration;
[0019] FIG. 3 is an assembled view of the holding device of FIG. 1 with the holding device shown in a configuration different from the configuration of FIG. 2 ;
[0020] FIG. 4 is a view of the holding device shown in use;
[0021] FIG. 5 is a detailed view of a portion of the holding device of the invention;
[0022] FIG. 6 is an exploded elevational view of a portion of the holding device of the invention;
[0023] FIG. 7 is a plan view of a holding member;
[0024] FIG. 8 is a detailed fragmentary view of a holding member;
[0025] FIG. 9 is a plan view of a connecting member; and
[0026] FIG. 10 is a fragmentary sectional view through a friction enhancing raised dimple.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0027] FIG. 1 of the drawing shows an exploded perspective view of a holding device 20 according to a preferred embodiment of the invention. The holding device has a first holding member 21 and a second holding member 22 . The device 20 includes an elongate connecting member 23 . The connecting member has a slot 24 extending along a substantial part of its length. An aperture 25 is located adjacent one end of the connecting member 23 . The holding member 21 may be clamped and held relative to the connecting member 23 by a clamp consisting of a clamping screw 26 , a washer 27 and a nut 28 . The clamping screw 26 has a head 29 with a scalloped appearance. This scalloped appearance is achieved by having concave portions 30 formed around the head. This allows the head 29 to be readily grasped and manipulated by the fingers of a user. The shank 31 of the clamping screw 26 an enlarged unthreaded portion 32 from which extends a reduced diameter threaded portion 33 . The washer 27 is made of a flexible material and has a central aperture 34 through which the threaded portion 33 of the shank 31 may extend.
[0028] The holding member 21 has a central body portion 40 from which extend oppositely directed wings 41 and 42 . An inner face 43 of wing 41 is provided with a projection 44 which is directed towards the body portion 40 . The body portion 40 has an aperture 45 for receiving the threaded portion 33 of the shank 31 .
[0029] Wing 42 has a projection 46 extending from face 47 thereof. The projection 46 is also generally directed towards the body portion 40 of the holding member 21 . The threaded portion 33 of the shank 31 is received within the nut 28 and the nut 28 is held captive by a recess (not visible in this figure) in the side of the holding member 21 not visible in this view. A plurality of raised friction enhancing dimples 48 extend around the aperture 45 .
[0030] The holding member 21 has a plurality of raised projections 49 extending outwardly from the wing 42 and raised projections 50 extending outwardly from the wing 41 . These projections allow the holding member to be more readily grasped by the user and assist in strengthening the wings 41 and 42 .
[0031] The holding member 22 is similar in construction and configuration to holding member 21 . The holding member 22 may be clamped relative to the connecting member 23 by a clamp consisting of a clamping screw 56 , a washer 57 and a nut 58 identical in construction to the clamping screw 26 , washer 27 and the nut 28 which form the clamp which functions to clamp the holding member 21 to the connecting member 23 .
[0032] FIG. 2 of the drawings shows an assembled view of the holding device in a first configuration where the holding member 22 is held clamped to the connecting member 23 at one end of the slot 24 by a clamp including clamping screw 56 as one of the components. The holding member 21 is shown clamped to the connecting member 23 by a clamp which includes clamping screw 26 which extends through the aperture 25 (see FIG. 1 ) extending through the connecting member 23 and at a location near an end of the connecting member 23 spaced from the location of holding member 22 and the slot 24 in the connecting member 23 .
[0033] FIG. 3 of the drawings shows the holding device 20 of the invention in a configuration different from that of FIG. 2 . In this view, the holding members 21 and 22 are clamped to the connecting member in a position closer to one another than what is shown in FIG. 2 . Thus, the holding member 22 is adjustable in position along the connecting member relative to the position assumed by holding member 21 . In addition to the relative positions of the holding members being adjustable so that they are spaced to a desired degree from one another, it is also possible to clamp the holding members 21 and 22 relative to the connecting member 23 at any desired radial position relative to the connecting member 23 . If desired aperture 25 may be omitted and both holding members 21 and 22 may be clamped to connection member 23 by screws 26 and 56 which may both extend through the slot 24 . If desired the slot may extend substantially along the full length of member 23 .
[0034] FIG. 4 of the drawings shows a view of the holding device 20 in a position it would assume in use when secured to sprockets 60 and 61 . The sprockets 60 and 61 are intended to be representative of timing sprockets mounted to the ends of cam shafts of an engine. A timing belt 63 is trained to extend over the sprockets 60 and 61 . The belt 63 would normally have a tensioning device (not shown) associated with it and would extend or be trained over a timing gear (not shown) associated with the engine of which the two cam shafts would form a part. The timing belt 63 has a plurality of teeth 64 adapted to engage within recesses 65 between adjacent teeth 66 and 67 on the sprockets 60 and 61 . The holding members 21 and 22 are clamped to the connecting member 23 by the respective clamps of which the clamping screws 26 and 56 form a part. The projections 44 and 46 extending from the holding members 21 and 22 locate relative to recesses between adjacent teeth on the sprockets 60 and 61 and when the holding members 21 and 22 are clamped in the way shown in FIG. 4 the holding device functions to prevent relative rotation of the sprockets 60 and 61 .
[0035] With the holding device 20 fitted in the manner shown in FIG. 4 , the tensioning device mentioned above may be relaxed and this allows the timing belt 63 to be removed from engagement with the sprockets 60 and 61 and replaced. When the timing belt is replaced with a new timing belt the tensioning device may then be used to once again tension that replacement belt and once this is done the holding device of the invention may be removed.
[0036] FIG. 5 of the drawings shows a fragmentary perspective view of part of the holding device 20 of the invention. In this view, the reverse side of the holding member is visible. The nut 58 is received within a recess formed on the reverse side of the holding member 22 .
[0037] The holding member 21 is configured in a manner identical to the holding member 22 shown in FIG. 5 .
[0038] As shown in FIG. 5 , the underside of the connecting member 23 is provided with a plurality of raised friction enhancing dimples 70 . These dimples extend around the slot 24 and also around the underside of the member 23 adjacent aperture 25 . These dimples, together with the dimples 48 on the connecting members 21 and 22 assist in preventing movement of the holding members 21 and 22 relative to the connecting member 23 once the holding members 21 and 22 are clamped in position relative to the connecting member 23 .
[0039] FIG. 6 of the drawings shows an exploded part sectional view of a portion of the device 20 of the invention. The nut 28 is shown received in a recess provided in the body portion 40 of the holding member 21 . When the washer 27 is held captive between the connecting member 23 and the holding member 21 , the dimples 70 and 48 may project slightly into the washer 27 . This action together with the clamping action by screw 26 assist in securely holding the holding member 21 relative to the connecting member 23 and prevent it from moving relative to the connecting member.
[0040] FIG. 7 of the drawings shows a plan view of one of the holding members 21 , 22 . As shown in this figure and in the fragmentary view of FIG. 8 , the projection 44 has a stepped profile with a reduced width outer end 80 and a wider inner portion 81 . Projection 46 is similarly configured. By having the projections shaped in this way they may more readily locate relative to recesses 65 between adjacent teeth on sprockets of a variety of different sizes.
[0041] As shown in FIG. 9 , the raised friction enhancing dimples 70 extend around the slot 24 in the connecting member 23 and also extend around the aperture 25 . In this embodiment of the device, the dimples 70 may have a shape like that shown in the enlarged fragmentary sectional view of FIG. 10 . The dimples 48 which extend around the aperture 45 in the holding member shown in FIG. 47 may have a configuration the same as that for dimples 70 . | There is disclosed a holding device for holding two rotary members relative to one another. The device has two holding members and a connecting member to which the holding members may be clamped by respective clamps. One of the holding members may be selectively positioned along the connecting member and clamped thereto at selected distances from the other holding member. | 1 |
BACKGROUND OF THE INVENTION
The invention relates to a machine tool for stamping and grooving, used, particularly, in the manufacture of folding blanks made from sheets of cardboard, paperboard or the like, having a stamping die plate and a strip steel punch plate affixable on machine stamping plates capable of being moved toward each other. Plastic die plates are known which are produced, in accordance with the German Pat. No. 1,210,310, as follows: An engraved metal plate serves as the primary matrix, from which a punch plate made of thermoplastic material or a synthetic resin is produced. A series of die plates is produced, also from thermoplastic material or synthetic resin, by means of the above-mentioned primary matrix. These die plates, however, have the disadvantage that they are expensive to manufacture, do not have a long service life, and are greatly limited as to their capacity for maintaining accuracy as to gauge with fluctuations in temperature. In addition, it is difficult to obtain precise orientation of the die plate and the strip steel punch plate with respect to each other.
OBJECT AND SUMMARY OF THE INVENTION
The object of the invention is to provide a stamping and grooving machine tool which can be manufactured simply and precisely, which has a long service life, and which can be easily mounted.
In order to attain this object, the invention provides that the die plate is configured as a plate whose circumferential, marginal edges and whose grooves and ribs, intended to provide the fold lines in accordance with the contours and folds of the desired folding blank, are produced by means of program-controlled tools; the die plate is provided with alignment openings into which alignment pins of the strip steel punch plate can be introduced and, on one side, has an adhesive layer by means of which it can be fixed adhesively to one of the machine stamping plates. In this manner, as many entirely identical die plates as desired can be cut from one initial plate and then be oriented precisely to the strip steel punch plates. The substance used to make the die plates can be selected in such a manner that deviations from the correct measurements for the die plate and the punch plate caused by temperature factors can be quite substantially avoided. Because of the durability of the plates, high levels of piece production can be attained. The manufacture of the die plates and the precise mounting thereof onto the machine stamping plates can be accomplished with particular simplicity.
In a particularly advantageous fashion, the plate used for the die plate is made of hard paper (bakelized or laminated paper) whose underside opposite the grooves is provided with a reinforcement layer of glass or of metal. In other words, the material used is a molded laminated plastic, and in particular a phenoplast laminated material having paper as the resiniferous member. Glass fibers, in particular, serve as the reinforcement layer.
For cutting out and grooving the die plate, cutters are used in the form of milling cutters, especially end-milling cutters which in order to form the grooves may be of cylindrical shape with a perpendicular front face and in order to cut out the die plate along its intended contour, may have an oblique configuration, so that the rim of the plate is made oblique and the underside is then larger than the upper side. The separation or cutting out of the die plate is not performed completely, so as not to damage the seating of the initial plate; the very thin connection which remains is subsequently cut through or punched out. In an efficient manner, the initial plate is held clamped to the machine support by means of a vacuum. It has a thickness of less than 1 mm; the bottom of the groove is at a distance from the plate underside of less than 0.3 mm and preferably 0.1 mm. This very short distance permits clean impressions and as a result of the reinforcement layer, there is no need to fear tearing or damage caused by bending.
It is particularly advantageous that the adhesive layer be applied as a double-sided adhesive foil. The die plate thereby attached to the machine stamping plate is then ready for immediate use.
Like the circumferential marginal edge and the grooves or ribs, the alignment openings are also produced by means of a program-controlled tool so that great precision is attained. It is of particular advantage that the program control for the guidance of the tools in manufacturing the die plate can also be used for producing the slits and openings for the reception of the alignment pins in the manufacture of the punch plates, particularly when the slits in a base plate for introduction of the strip steel are produced by means of laser beams. The program control functions efficiently by way of a data carrier, which stores data from a process controller pertaining to the desired contour and grooving of the die plates; a numerical control, continuous path guide means is of particular advantage.
In accordance with a further characteristic of the invention, the alignment pins can be countersunk in the openings of the base plate of the punch plate. After the die plate has been placed on the machine stamping plate, the alignment pins are pushed, so that they do not come into contact with the product to be stamped. When a change of die plates is made, the pins can be returned to their working position again.
By the above method of producing the die plates and punch plates, it is assured that the contours of die plate and punch plate match perfectly; all the outer contours are congruent. Each contour, straight line, angle, arc path and the like recorded on the data carrier can be verified by the control means. When care is taken in the process, the die plates can be removed from the machine stamping plate and reused.
The invention will be better understood as well as further objects and advantages thereof become more apparent from the ensuing detailed description of a preferred embodiment taken in conjunction with the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a section view through a stamping and grooving machine tool along with the machine stamping plates;
FIG. 2 is a plan view of a die plate;
FIG. 3 is an enlarged partial sectional view of the die plate taken along the line III--III of FIG. 2; and
FIG. 4 is an enlarged partial sectional view through a different die plate.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The machine tool of the invention comprises a strip steel punch plate 1 (stamping mold) and a die plate 2. The strip steel punch plate 1 is secured to one machine stamping plate 3 and is locked into a locking frame, not shown in further detail. The die plate 2 is made to adhere to the opposite machine stamping plate 4.
The strip steel punch plate 1 has a base plate 5 which, as a rule, is made of plywood. By means of laser beams, slits 6 are formed in this base plate 5 into which the strip steel 7 is received. The strip steel 7 is rounded on its protruding front face in order to form grooves by impression and has a knife edge in order to cut the contours. The laser is guided in producing the slits 6 by a numerical-control, continuous path guide means. Further, the laser is also used to form through openings 8 into which alignment pins 9 are introduced.
The die plate 2 comprises hard paper (bakelized or laminated) and known under the trade name Pertinax which is provided on its underside 10, as shown in FIGS. 3, 4, with a reinforcement layer 11 (of glass fibers or metal). Placed on the underside 10 is an adhesive layer 12 in the form of a double-face adhesive foil 13, which is at first covered by a protective paper 14, the side of which, oriented toward the adhesive, is siliconized. Thus the die plate 2 forms a smooth plate 15, which is cut out from a larger initial plate, which is not shown. This cutting operation is performed by a milling tool, namely an end-milling cutter having a conical shape. To this end, the initial plate is clamped on the machine table, and may be held by suction created by a vacuum. The milling cutter, like the laser in producing the strip steel punch plate 1, is guided by a numerical-control, continuous path guide means, so that there is congruence with the laser shape. Because of the conical shape of the milling cutter, the rim 16 is made oblique. In order not to damage the machine table, the mill cutting at the contours is not performed completely through to the underside 10, but rather a very thin connection remains, which is subsequently cut off or punched out.
By means of a second, cylindrical end-milling cutter having a perpendicular front face, grooves 17 are milled in, which are U-shaped in cross-section as a result of the shape of the milling cutter; thus, their sides 18, 19 run perpendicular to the upper side 20 of the die plate 2. The grooves 17 lie opposite the corresponding strip steel 7 acting as the grooving tool and are necessary to attain a clean grooving of the product to be stamped. The milling cutter for the grooves 17 is also program controlled, as is the tool by means of which at least two alignment openings 21, 22 are made in the plate 15. The bottom 23 of the groove 17 is at a distance 24 from the underside 10, for example, 0.1 mm, with a plate thickness 25 of 0.6 mm. The adhesive foil 13, without the protective paper 14, has a thickness of 0.05 mm.
In addition to grooves 17, ribs 26 can also be formed in the plate 15, being created by means of corresponding milled-out areas 27. By means of the grooves 17, positive grooves are formed in the product to be stamped, while by means of the ribs 26, negative grooves are formed in the product.
The introduction of the machine tool into the machine is performed as follows:
First, the strip steel punch plate 1 is locked onto the machine stamping plate 3 in the locking frame. Then the die plate 2 is placed onto the alignment pins 9 located in the strip steel punch plate 1, so that the adhesive layer 12, from which the protective paper 14 has first been removed, faces toward the machine stamping plate 4. Then the machine stamping plates 3, 4, under reduced pressure, are driven together and then separated again. In so doing, the die plate 2 adheres to the machine stamping plate 4. The alignment pins 9 are pushed back into their through openings 8 when the plates 3, 4 are driven together, and they remain in this retracted position in the base plate 5 during the entire stamping procedure. The pins 9 and the base plate 5 are dimensioned such that there is sufficient space for the pins 9 to remain in the base plate 5 out of contact with the product to be stamped.
In order to obtain entirely uniform adhesion, a rubber plate is placed between the stamping plates 3, 4; if the plates are driven together again, uniform adhesion is assured. At this time, the operational procedure can begin immediately. A first sheet of cardboard, paperboard or the like is permitted to enter the work area and pressure is applied. After the sheet exits the work area, the product is examined to determine whether the cardboard is correctly stamped; if not, appropriate corrections are made. When a second sheet has been stamped, an examination is made as to whether the respective cutting lines and groove lines are correctly placed.
The foregoing relates to a preferred embodiment of the invention, it being understood that other embodiments and variants thereof are possible within the spirit and scope of the invention, the latter being defined by the appended claims. | A machine tool for stamping and grooving paperboard for forming folding blanks which includes a die plate of fiber-reinforced, hard paper provided with marginal edges, ribs and grooves formed by means of program-controlled tools and having alignment openings for receiving alignment pins, the die plate being adhesively secured to one of the machine stamping plates. | 1 |
CROSS REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of U.S. patent application of Robert D. Fogal et al., Ser. No. 08/566,018 filed Dec. 1, 1995, now abandoned, which application is a continuation of U.S. Pat. No. 5,472,023 issued to Fogal, Sr. et al., filed Dec. 5, 1995 Ser. No. 08/229, 536 filed Apr. 19, 1992 and a continuation-in-part of U.S. Pat. No. 5,386,857 issued to Fogal, Sr., et al., Feb. 7, 1995 Ser. No. 08/040,289 filed Mar. 30, 1993. U.S. patent application 08/566,018, and U.S. Pat. Nos. 5,472,023 and 5,386,857 are expressly incorporated by reference herein.
FIELD OF INVENTION
The present invention relates generally to the field of dynamic wheel assembly balancing utilizing a pulverulent material introduced into a pneumatic tire mounted on a wheel, and more particularly to a method and apparatus for quickly and accurately dispensing a predetermined amount of pulverulent material from a source thereof, and thereafter distributing the pulverulent material to a workstation for introduction into a tire mounted on a wheel or rim.
BACKGROUND OF THE INVENTION
The present invention is directed to the general field of dynamically balancing the wheel assemblies found on automobiles, trucks, airplanes, and other vehicles by introducing a predetermined amount of a pulverulent material, such as a product sold under the trademark EQUAL® by International Marketing, Inc. of Chambersburg, Pa., into a pneumatic tire which is mounted on a wheel or rim of the wheel assembly. As used herein, the terms "wheel assembly" and "tire assembly" each refer to a tire mounted on a wheel or a rim.
The specifics of the method of balancing a wheel assembly (including equalizing radial and lateral force variations) by introducing a pulverulent material into the tire thereof are fully disclosed in U.S. Pat. No. 5,073,217 issued to Robert D. Fogal on Dec. 17, 1991, all of which patent is also expressly incorporated by reference herein. As is described in U.S. Pat. No. 5,472,023, introducing pulverulent material into a tire of a wheel assembly generally involves confining a predetermined amount of pulverulent material; subjecting the confined pulverulent material to pressurized air currents; and, introducing the pulverulent material into a tire through an associated tire valve stem under the force of the pressurized air currents. This prior patent also describes two different applicator devices for performing the above method. While these devices are effective in carrying out these operations, they require the operator thereof to perform a variety of time consuming manual steps. For example, once the operator determines the proper amount of pulverulent material to be utilized within a tire, the operator must manually dispense this predetermined amount (typically in terms of weight) and place the same within the cylinder of the applicator device. The applicator device must then be sealed and connected between the tire valve stem of the wheel assembly and a source of compressed air such as a shop air line. Once the applicator device is properly connected, the operator must manually open one or more valves to allow compressed air to flow into the applicator and an admixture of compressed air and pulverulent material to exit the applicator and travel into the tire through the associated tire valve stem.
In addition to the above steps required of an operator during the application procedure, the operator must also perform a number of preliminary steps to prepare the tire to receive the pulverulent material. If the tire has just been mounted on a wheel or rim, the operator must first "bead" the tire--i.e., compressed air must be introduced into the tire to ensure that the bead of each sidewall is properly seated against its respective rim flange. Once a tire is beaded properly, it must be at least partially deflated so that it will not become overinflated upon the introduction of the compressed air and pulverulent material into the tire. An operator has heretofore been required to bead a newly mounted tire prior to connecting the valve stem of the wheel assembly to the applicator apparatus. Also, the operator has heretofore been required to deflate or "bleed" an already mounted tire in preparation for the application procedure. Only after these steps have been performed, was the operator able to connect the valve stem of the tire to the applicator device. Finally, prior applicator devices typically require the operator to disconnect the tire therefrom in order to complete the application procedure by inflating the tire to its recommended tire pressure.
There has therefore been found a need to provide an applicator apparatus and a method for introducing a pulverulent material into a tire without the above-noted deficiencies of prior applicator devices and methods. Specifically, there has been found a need to provide an applicator apparatus that performs the "beading" operation (if required), performs pre-application partial deflation of the tire (if required), introduces the pulverulent material into a tire, and performs the final re-inflation procedure. There has also been found a need to provide an apparatus that quickly and efficiently dispenses a predetermined amount of pulverulent material from a source thereof into a confining space in preparation for its "application" or introduction into a tire.
SUMMARY OF THE INVENTION
In light of the foregoing and other deficiencies associated with prior art application methods and apparatus, the present invention is directed to an apparatus for introducing a pulverulent material into a tire of a wheel assembly, wherein the apparatus includes a container, preferably a hollow cylinder, for confining a predetermined amount of a pulverulent material. The container includes an inlet and is connected through the inlet and a conduit to a source of pulverulent material, such as a hopper, and also includes an air pressure variation orifice connected to a vacuum source such that pulverulent material may be pulled into the container from the hopper or other source in response to a vacuum force created within the container by the vacuum source. The container includes an outlet which is connected to a valve stem of a tire using a suitable conduit. The pressure variation orifice is also connected, in selective fluid communication, to a source of pressurized air such that the pulverulent material is evacuated from the container through the outlet and introduced into the tire in response to pressurized air currents created in the container upon the introduction of compressed air into the container through the pressure variation orifice.
The apparatus of the present invention preferably comprises two main types of components--the mainframe component and one or more workstation components, although the two types of components may be combined into a single component or further subdivided into additional components. Each workstation component serves as a location from which an operator of the apparatus introduces the pulverulent material into a tire. The mainframe component includes the above described container for confining a predetermined amount of the pulverulent material and includes the other components required to dispense the pulverulent material into the container from a hopper or the like, and to evacuate the pulverulent material from the container and distribute the same out to a workstation through a suitable conduit where the pulverulent material is introduced into a tire. The mainframe also includes a keyboard and display for an operator to enter and view data.
Each workstation includes a keypad for the entry of tire and other data, an outlet conduit for connection to a tire valve stem to introduce compressed air or an admixture of compressed air and pulverulent material into a tire, and each workstation also preferably includes an inlet conduit for connection to a source of compressed air. Each workstation also includes a valve for selectively opening the outlet conduit of the workstation to the atmosphere through a compressed air exhaust outlet, thereby allowing compressed air to be expelled from within a tire. It can be seen therefore, that once a tire is connected to the outlet conduit of a workstation, air may be released from the fire, air may be introduced into the tire, and the admixture of compressed air and pulverulent material originating at the mainframe may be introduced into the tire, without disconnecting the tire from the outlet conduit of the workstation, and without a large amount of operator time, effort, or intervention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial schematic view of an apparatus in accordance with the present invention, wherein a mainframe and two workstations are shown;
FIG. 2 is a schematic view showing the pneumatics of a mainframe component in accordance with the present invention;
FIG. 3 is a schematic view showing the electronics and electrical system of a mainframe component in accordance with the present invention;
FIG. 4 is a schematic view showing the pneumatics of a workstation component in accordance with the present invention;
FIG. 5 is a schematic view showing the electronics and electrical system of a workstation component in accordance with the present invention;
FIG. 6 is a cross-sectional view showing a container in accordance with the present invention;
FIG. 7 is a cross-sectional view of a hopper for storing a quantity of pulverulent material in accordance with the present invention; and,
FIGS. 8A and 8B are partial elevational views of two preferred arrangement of the purge and distribution pinch valves of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Reference will now be made in detail to the present preferred embodiment of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.
Referring specifically to FIG. 1, there is partially shown at 10 a schematic view of an apparatus in accordance with the present invention. The apparatus 10 comprises two main types of components, a mainframe type component 12, and a workstation type component generally shown at 14. In general, the apparatus 10 will include a single mainframe component 12 and one or more workstation components 14. While only two workstations 14a,14b are shown in FIG. 1, any number may be provided. FIG. 1 describes a preferred embodiment of the present invention 10, wherein connections are provided for up to eight workstations 14a-14h as is described in further detail below.
The mainframe component 12 dispenses a predetermined amount of a suitable pulverulent material from a source thereof into a container, and thereafter causes the pulverulent material to travel to the appropriate workstation 14 for introduction into a tire 13 (shown in phantom). Each workstation 14 is in selective fluid communication with the mainframe 12 through the use of a suitable distribution conduit such as pneumatic tubing 22a-22h, and once a workstation 14 is ready to receive the pulverulent material from the mainframe 12, the mainframe 12 dispenses the pulverulent material, and causes the same to travel through the appropriate tubing 22a-h to the requesting workstation 14 for introduction into a tire 13. The tire 13 is connected in fluid communication to a workstation 14 through a suitable outlet conduit such as pneumatic tubing 24. Tubing 24 preferably includes an air chuck type pneumatic fitting on a terminal end thereof such that tubing 24 can be connected in fluid communication to the tire valve stem of a tire 13 (the valve core is ordinarily removed from the tire valve stem to facilitate the movement of the pulverulent material therethrough). In this manner, a predetermined amount of pulverulent material originating at mainframe 12 can travel from the mainframe 12 through tubing 22 to a workstation 14, and through tubing 24 into a tire 13 through an associated tire valve stem. It is thought preferable, as is shown herein, to provide a distinct length of tubing 22 from mainframe 12 to each workstation 14, although other arrangements may be utilized.
The mainframe component 12 and the one or more workstation components 14 are preferably separate from one another, however, those skilled in the art will recognize that one or more workstations 14 may be combined with the mainframe 12 to form an apparatus 10 combining both the mainframe and workstation operations as are discussed in detail below. Again, as shown in FIG. 1, the apparatus 10 comprises two workstations 14a,14b, and those skilled in the art will certainly recognize that more or less workstations 14 may be provided and form a part of the apparatus 10, and the invention 10 is not meant to be limited to the particular arrangement shown herein.
The mainframe 12 is connected to and receives electrical power from an electrical power source such as a 115 Volt A.C. (VAC) supply 16 as is commonly found in the United States of America, or any other suitable electrical power source. Each work station 14 is also connected to an electrical power source, and preferably, groups of workstations 14 extending from mainframe 12 are connected through electrical wires 18 to receive electrical power, such as 115 VAC, from the mainframe 12, and if applicable, through an adjacent workstation 14. Alternatively, of course, each workstation 14 may be directly connected to a source of electrical power.
As is discussed in further detail below, the mainframe 12 and each workstation 14 are connected to a common data "bus" such as an RS-485 connection or bus 20 as is well known in the art of electronics such that each workstation 14 can exchange data with the mainframe 12. As shown herein, the apparatus 10 has an overall linear configuration, with a centrally located mainframe 12 and workstations 14 extending from opposite sides thereof, with connections 18,20 for electrical power and data transmission, respectively. Of course, the apparatus 10 may be provided in other configurations with alternative connections for power and data transmission.
Mainframe 12 and each workstation 14 are also connected to a source of compressed air 26. As is discussed below, mainframe 12 preferably uses compressed air (in conjunction with a venturi) to create a vacuum force for dispensing a predetermined amount of pulverulent material from a source thereof, and mainframe 12 also uses compressed air to force the thus measured pulverulent material out to the appropriate workstation 14, through tubing 22a-22h, and into a tire 13. Each workstation 14 is preferably independently connected to a source of compressed air 26 such that an operator of a workstation 14 can cause compressed air to be communicated into a tire 13 through tubing 24 in order to inflate or "bead" a tire. Alternatively, all workstations 14 and mainframe 12 may be connected to a common source of compressed air for inflation procedures. Also, each workstation 14 may include an exhaust outlet 28 through which compressed air is exhausted or "bled" from a tire 13 by entering workstation 14 through tubing 24, and exiting workstation 14 into the atmosphere through exhaust outlet 28. As is discussed below, bleeding air from tire 13 in this manner allows the bleeding operation to be automatically controlled. Of course, alternative systems exist for bleeding a tire, and for example, the tire 13 may be manually bled by the operator depressing the valve core pin (or removing the valve core altogether) and periodically checking the air pressure of the tire 13.
Referring now to FIG. 2 wherein the pneumatics of the mainframe component 12 are shown schematically, it can be seen that mainframe 12 is in fluid communication with a source of compressed air 26 through the use of suitable pneumatic tubing as is well known in the art of pneumatics. Preferably, source of compressed air 26 has an air pressure no greater than 165 pounds per square inch gauge (p.s.i.g.). Compressed air source 26 is in fluid communication with an air filter 27 for filtering moisture, dirt, and other contaminants from the compressed air. Compressed air from source 26 is communicated from filter 27 to two different air pressure regulators 30,32. The preferred embodiment of the invention 10 utilizes a first air pressure to perform the dispensing and distribution of the pulverulent material, and utilizes a second air pressure to control the operation of a plurality of pinch valves. Pinch valves are known in the art of pneumatics, and generally utilize a pressure variation of 20-30 p.s.i.g. to control open and closing operations of the valve. Therefore, air pressure regulator 30 provides an output air pressure used for dispensing and distribution of pulverulent material, for example, 80 p.s.i.g. and air pressure regulator 32 provides an output air pressure of 20-30 p.s.i.g. greater than the output of regulator 30, for example 105 p.s.i.g. and the output air pressure from regulator 32 is used primarily to close the various pinch valves (discussed more fully below) by providing a positive pressure variation over the 80 p.s.i.g. air pressure used for dispensing and distributing the pulverulent material.
Referring now to the output from air pressure regulator 30, a first solenoid valve 40 is provided in fluid communication therewith. Solenoid valves are well known in the art and are used to selectively block and unblock fluid communication through a conduit (such as pneumatic tubing) with which the solenoid valve is in fluid communication. Outlet of first solenoid 40 is in fluid communication with a venturi 52 which is preferably a single-stage venturi which generates a vacuum of approximately in the range of 20 inches of mercury or more. A check valve 44 may be provided between venturi 52 and solenoid 40 if desired. Venturi 52 includes an inlet port in fluid communication with pneumatic tubing 53, an outlet or exhaust port in fluid communication with pneumatic tubing 54, and a vacuum port in fluid communication with pneumatic tubing 55. Those skilled in the art will recognize that the flow of compressed air from pneumatic tubing 53 into venturi 52 and out of venturi into pneumatic tubing 54 will create a vacuum force pulling air into venturi 52 through pneumatic tubing 55. As is explained below, this vacuum force is utilized to create a relatively low pressure condition or "vacuum" condition in a container 56, relative to ambient air pressure, such that pulverulent material P is withdrawn or suctioned from hopper 50 through fitting 61 (FIG. 7) and tubing 60 into container 56. In the preferred embodiment, container is a generally hollow cylinder 56 as is shown in FIG. 6. Tubing 55 is therefore connected between vacuum port of venturi 52 and cylinder 56 such that a relatively low pressure area or vacuum may be created in cylinder 56 as desired. Those skilled in the art will certainly recognize that venturi 52 is only one of a wide variety of vacuum generators that may be utilized to create a vacuum force in cylinder 56, and the invention is not meant to be limited to the particular vacuum generator shown herein. Additionally, although it has been found preferable to utilize a vacuum force to withdraw the pulverulent material P from the hopper 50, it should be recognized that the pressure differential causes the pulverulent material P to be dispensed from hopper 50 into cylinder 56, and therefore, positive air pressure may alternatively be used.
Output from air pressure regulator 32 is in selective fluid communication with a lower portion of a pulverulent material storage hopper 50 through a pilot valve 41 (discussed more fully below). Hopper 50 (see also FIG. 7) contains a quantity (such as 5-7 gallons) of pulverulent material P therein. The flow of compressed air from regulator 32 through pilot valve 41 is preferably directed through conduit 43 into the lower portion of hopper 50, through a diffuser 51. Diffuser 51 is preferably conical or otherwise non-planar and includes holes 53 covered with a mesh or screen material (not shown) which is provided to prevent the pulverulent material P from falling downward through holes 53 into the area below diffuser 51. As is described fully below, the compressed air from conduit 43 causes the pulverulent material P to be dispersed in a cloud or admixture throughout hopper 50 such that the pulverulent material P can be suctioned from hopper 50 through fitting 61 into tubing 60 without forming voids and caves during its evacuation from hopper 50. Hopper 50 is initially filled with a quantity of pulverulent material P by pouring the pulverulent material P through funnel-shaped insert 150 having an orifice 152 formed therethrough. When the apparatus 10 is in operation, a cover member is secured in position over the hopper 50 as shown with the use of latches 158 or the like. Cover includes an exhaust vent 156 and a filter 159 is positioned over orifice 152 to prevent the pulverulent material from escaping hopper 50 when air is exhausted through orifice 152. Although the pulverulent material P is preferably dispensed from hopper 50 with the use of a vacuum force, compressed air is also directed into hopper 50 to stir the pulverulent material P, and therefore, orifice 152, filter 159 and cover vent 156 must be provided.
Referring to FIGS. 2 and 6, and specifically the cylinder 56, it can be seen that the cylinder comprises a wall portion 57 capped at its ends by upper and lower bulkheads 58,66, respectively. O-ring seals 21a,21b are provided between wall 57 and bulkheads 58,66 to facilitate the formation of an air-tight seal therebetween. Bulkhead 58 includes a pulverulent material inlet 59 formed therethrough and in fluid communication with a suitable conduit such as tubing 60. Inlet 59 has a diameter in the range of 1/2" is in selective fluid communication with pulverulent material hopper 50 through tubing 60 and pinch valve 62. Although not required, inlet 59 may be provided coaxial with the longitudinal axis L of cylinder 56 as shown. As is discussed above and in further detail below, pinch valve 62 selectively blocks the communication of pulverulent material from hopper 50 into cylinder 56 through tubing 60. It can be seen most clearly in FIG. 6 that upper bulkhead 58 of cylinder 56 also includes at least one pressure variation port 64 formed therethrough and in fluid communication with tubing 55 such that a vacuum or relatively low pressure relative to ambient pressure can be generated in cylinder 56 through pressure variation port 64 in response to the vacuum force created by venturi 52. (To evacuate pulverulent material from cylinder 56 as is explained below, a high pressure, relative to the air pressure within a tire, is established in cylinder 56 through the introduction of compressed air into cylinder 56 through pressure variation orifice 64). Pressure variation port is substantially smaller in diameter than inlet 59.
Lower bulkhead 66 of cylinder 56 includes a pulverulent material outlet port 69 formed therein having a diameter in the range of 1/8". The axis of outlet port 69 preferably intersects the wall 57 of cylinder 56 at an oblique angle such that the evacuation of pulverulent material from cylinder 56 is facilitated. Specifically, during the evacuation of cylinder 56, the pulverulent material and compressed air form a swirling admixture within cylinder, and the location of the outlet port 69 as described has been found to result in a more complete evacuation of cylinder 56 through a suitable outlet conduit such as tubing or pipe 68. Conduit 68, which may be a combination of pneumatic tubing lengths and pneumatic fittings as shown in FIG. 8A, for example, is in selective fluid communication with each workstation 14 through tubing 22a-h and a network of distribution pinch valves 70a-70h, respectively, such that pulverulent material can be distributed to any one of the workstations 14 as required and is discussed below. In addition to being connected to each of the workstations 14, conduit 68 is in selective fluid communication with hopper 50 through pinch valve 72 and purge tubing 23 such that if the incorrect amount of pulverulent material is dispensed into cylinder 56, it may simply be evacuated therefrom as is discussed in further detail below, and directed through purge tubing 23 back into hopper 50. Conduit 68 is preferably metallic or made of another suitable wear resistant conduit material along at least a portion thereof extending from cylinder 56, to resist wear caused by the pulverulent material traveling therethrough at a high rate of speed as occurs upon evacuation of pulverulent material from cylinder 56.
The arrangement of purge pinch valve 72 and distribution pinch valves 70a-70h shown in FIG. 8A has been found to be an effective arrangement for ensuring that the pulverulent material contained within conduit 68 is directed to the proper workstation 14. It can be seen that the pinch valves 72, 70a-70h are arranged in a stair-step fashion with conduit 68 provided by a combination of pneumatic tubing 68a and other pneumatic fittings 68b-68f. Conduit 68 is ultimately terminated by a plug or a closed fitting. The arrangement of pinch valves 72,70a-70h as shown makes it less likely or impossible for pulverulent material traveling through conduit 68 to substantially "overshoot" its destination purge conduit 23 or distribution conduit 22a-22h (the destination conduit being the one conduit 23,22a-22h with an open pinch valve 72,70a-h, respectively), as would occur if conduit 68 were simply linear. FIG. 8B shows another preferred arrangement for conduit 68 (without showing the associated pinch valves 62, 70a-70h, 72, 74) wherein pneumatic fittings 68b, 68d, 68f are modularly connected in fluid communication and wherein conduit 68 is terminated by an end cap 68g.
Referring again to FIGS. 2 and 7, the outlet or exhaust of venturi 52 is connected to tubing 54 which is in selective fluid communication with hopper 50 through a pinch valve 74. In this manner, when pinch valve 74 is open, as it will be when venturi 52 is utilized to create a vacuum force, the exhaust flow from venturi 52 is directed into hopper 50 and acts to further stir the pulverulent material P stored therein to facilitate the easy removal of pulverulent material P from hopper 50. The outlet of air pressure regulator 30 is also in fluid communication with tubing 55 (and consequently pressure variation orifice 64 of cylinder 56) through a second solenoid valve 42. Second solenoid valve 42 is provided to allow selective direct fluid communication between outlet of air pressure regulator 30 and pressure variation orifice 64 of cylinder 56 as is required during the positive pressure evacuation of pulverulent material from cylinder 56.
As described herein, the apparatus 10, and specifically the mainframe component 12 includes a plurality of pinch valves 62,70a-70h,72,74 for selectively blocking and unblocking fluid communication through the lengths of pneumatic tubing 60,22a-22h,23,54, respectively. Pinch valves are well known in the pneumatic arts and are particularly well suited for selectively blocking and unblocking the flow of a slurry such as an admixture of pulverulent material and compressed air. In general, a pinch valve is a bladder-type valve which is normally open to allow a flow therethrough at a first pressure. However, when a second pressure is applied to the bladder that is 20-30 pounds per square inch (p.s.i.) greater than the first pressure at which the flow is occurring through the valve, the bladder closes to prevent any further flow through the valve. In the present case, as discussed above, an air pressure regulator 32 is provided and has an output air pressure that is approximately 25 p.s.i. greater than the output of air pressure regulator 30. The output of air pressure regulator 30 is used to dispense the pulverulent material into the cylinder 56 and to distribute the pulverulent material to each workstation 14 and into a tire 13. The output of air pressure regulator 32 is used only to close the various pinch valves 62,70a-70h,72,74.
Each pinch valve 62,70a-70h,72,74 is respectively connected to the output of air pressure regulator 32 through a pilot valve 63,71a-71h,73,75. As described herein, pilot valves 63,71a-71h,73,75 are electrically controlled and when open, allow fluid communication between output of second air pressure regulator 32 and their respective pinch valves 62,70a-70h,72,74 to cause the closing of the pinch valves 62,70a-70h,72,74 under the force of the air pressure originating at output of second air pressure regulator 32. For example, pilot valves 63,71a-71h,73,75 may be 0.08 CV airflow with 5/32" quick-connect ports. As mentioned above in relation to FIG. 2, a similar pilot valve 41 is also provided to selectively allow fluid communication between second pressure regulator 32 and lower portion of hopper 50.
FIG. 3 schematically shows the electrical and electronics systems of the mainframe component 12. As discussed in relation to FIG. 1, mainframe 12 receives electrical power through an electrical connection to a power source 16 such as a 115 VAC as is typically found in the United States of America or by a connection to any other suitable power source. Power source 16 is preferably connected to a 115 VAC terminal block 80 to facilitate power distribution to the various components discussed herein. A power surge suppressor 82 is provided to prevent voltage surges from damaging the electrical system of the apparatus 10. A circuit breaker 84 is also provided to prevent excessive electrical current from flowing through the electrical system of the apparatus 10. Terminal block 80 includes outputs 18, discussed above in relation to FIG. 1, for providing electrical power to the workstations 14 of apparatus 10. Terminal block 80 is connected to a direct current (DC) power supply 86 having dual output voltages of 5 volts and 12 volts to control the mainframe electronics discussed herein and solenoid valves 40,42, respectively. Alternatively, separate power supplies may be provided for the solenoids 40,42 and the electronics to prevent power surges to the electronics by operation of solenoid valves 40,42. A chassis cooling fan 81 is also provided and receives power from terminal block 80.
Power supply 86, includes a first output connected to a computer system motherboard such as a PC system motherboard 90. Motherboard 90 is also connected to a keyboard 92 and a data storage device such as a 3.5" floppy disk drive 94, to receive input data therefrom. Disk drive 94 may be connected to motherboard 90 and controlled by a PC system IDE controller card 95 as is well known in the art of electronics and computers. PC motherboard 90 is also connected to a display monitor 96 for displaying output data to an operator of the apparatus 10. Monitor 96 may be a CRT display monitor or an LCD monitor and is connected to the PC motherboard 90 through the appropriate interface video card 97 as is well known. PC motherboard 90 and the electronic devices associated therewith may be utilized to record information about the operation of the apparatus 10, including the number and types of tires treated, the amount of pulverulent material dispensed, and other information relating to the machine operations.
Output of power supply 86 is also connected to a peripheral driver board 100 which functions as an input/output device for the solenoid valves 40,42, pilot valves 41, 63,71a-71h,73,75, and the RS-485 bus 20 (discussed above in relation to FIG. 1) such that each workstation 14 can exchange data with the mainframe 12. Peripheral driver board 100 also includes an emergency stop switch 102 connected thereto such that an operator of the apparatus 10, and specifically the mainframe component 12 thereof, can shut down the operations of the apparatus by pressing the emergency stop switch 102. The dispensing and distribution of the pulverulent material is controlled by a microcontroller 110, such as a Motorola 68HC11 microcontroller, and each workstation 14 also includes the same or a similar microcontroller 170 (FIG. 5). Microcontroller 110 therefore includes a plurality of connections with peripheral driver board 100 such as a parallel data connection 111, an expansion bus connection 112, a serial data connection 113, and a digital input/output connection 114, a 5 volt D.C. power connection 115, and a reset control connection 117. Microcontroller 110 is also connected to the PC system IDE controller card 95 such that controller 110 can request and receive data from disk drive 94. Mainframe 12 also includes a reset switch 116, which is preferably key operated for security purposes, used to reset the electronics of the mainframe 12.
Cylinder 56 into which the pulverulent material is dispensed is supported on a weigh scale or other weight sensor such as load cell 105 which is connected to peripheral driver board 100 through electrical connection 106 (see also FIG. 6). Load cell 105 utilizes a strain gauge to accurately measure the weight of pulverulent material in the cylinder 56, although other weight measuring devices may be utilized to determine the weight of pulverulent material within the cylinder 56. Load cell 105 is connected to peripheral driver board 100 through connection 106 (FIG. 3), and is consequently connected to microcontroller 110 such that the weight of pulverulent material in the cylinder 56 can be continually monitored to ensure that the correct predetermined amount of material is dispensed from hopper 50. Upon the load cell 105 sensing the predetermined amount of pulverulent material in the cylinder 56, the flow of pulverulent material from the hopper 50 into the cylinder is stopped by microcontroller 110 as is described below.
Referring now to FIG. 4, the pneumatics of a workstation component 14 in accordance with the present invention 10 are shown. For simplicity, the pneumatics of workstation 14a are shown, although those skilled in the art will recognize that the pneumatics of the other workstations 14 are in accordance with those of workstation 14a. As discussed in relation to FIG. 1, workstation 14a is in fluid communication with an external source of compressed air 26 which preferably has a maximum air pressure of 165 p.s.i.g. Compressed air from source 26 is connected to workstation 14a through an in-line moisture filter 120 used to remove moisture and other contaminants from the compressed air. Outlet of filter 120 is coupled to a pressure regulator 122 which is configured to provide an output air pressure in the range of 80-110 p.s.i.g. and most preferably 80 p.s.i.g. Pneumatic tubing 24 connects outlet of pressure regulator 122 and an air chuck 128 through a workstation solenoid valve 124, which is a three position valve which may be closed, open to a first position for fluid communication between conduits 24,28, or open to a second position for fluid communication between air supply 26 and conduit 24. An air chuck is a pneumatic fitting for mating in fluid communication with a tire valve stem of a pneumatic tire as is well known in the art of pneumatic tires. Air chuck 128 is coupled to a tire valve stem (not shown) of tire 13 and consequently is in fluid communication with the interior of the pneumatic tire 13. In its second open position, solenoid valve 124 allows selective communication of compressed air from outlet of air pressure regulator 122 to air chuck 128 as is well known in the art. When solenoid valve 124 is open to its second position, a tire 13 may be beaded, as discussed above, or may be fully inflated to operating air pressure through pneumatic tubing 24 and air chuck 128. As was noted above in relation to FIG. 1, each workstation 14 may also be utilized to deflate or partially deflate a tire 13. FIG. 4 shows that tire 13 is in selective fluid communication with compressed air exhaust outlet 28 through a workstation solenoid valve 124, and a tire may be deflated or partially deflated by opening solenoid 124 to its first open position which allows fluid communication between conduits 24,28.
It can also be seen that pneumatic tubing 24, air chuck 128, and tire 13 are in fluid communication with one of pneumatic tubes 22a-h (22a in the example shown) originating at mainframe 12 for carrying an admixture of pulverulent material and compressed air to the workstation 14. When a particular workstation 14 has requested that the pulverulent material be dispensed and distributed thereto, the mainframe 12 causes the pulverulent material to be distributed to the workstation 14 through its respective pneumatic delivery tubing 22a-h. With respect to workstation 14a shown, those skilled in the art will recognize (and it is further explained below) that the admixture of pulverulent material and compressed air can travel through pneumatic tubing 22a, into pneumatic tubing 24, and directly into tire 13 through air chuck 128 and the valve stem of the tire 13.
FIG. 5 schematically shows the electrical and electronic systems of each workstation 14. As noted above, each workstation 14 is connected to a common electrical power bus 18 so as to receive electrical power, such as 115 VAC therefrom. Also, each workstation 14, along with the mainframe 12, is connected to a common data bus 20 such as the previously described RS-485 bus, to send data to and receive data from the mainframe 12. The common electrical power bus is connected to a 115 VAC terminal block 140 which is preferably electrically grounded at 141. Terminal block 140, which preferably includes a circuit breaker 143, provides 115 VAC input to a DC power supply 142 having 12 VDC output to provide electrical power to the first and second workstation solenoid valves 124,130 and having a 5 VDC output to provide electrical power for the other workstation electronics as discussed herein. As with mainframe 12, two separate power supplies may be utilized for the electronics and solenoid valves 124,130 to prevent power surges. Outputs from power supply 142 are connected to workstation peripheral driver board 150 which functions as an input/output device for the various components of each workstation 14, including a workstation keypad or keyboard 152 for data entry, a workstation display such as an LCD 154 for data viewing by an operator of the workstation 14, the first and second workstation solenoid valves 124,130, an emergency stop switch 156 for shutting down machine operations in the event of an emergency, and a beeper 158 used to provide audio information to an operator of the workstation 14. The peripheral driver board 150 is also preferably connected to a tire air pressure sensor 160 which is a part of air chuck 128 connected to tire valve stem of a tire 13. Sensor 160 sends data regarding the air pressure contained within a tire 13 to peripheral driver board 150. As is shown in phantom, peripheral driver board 150 may also be connected to a runout sensor 162 (which may be a mechanical sensor, an optical sensor, or any other suitable runout sensor) for sensing the radial and/or lateral runout of a tire 13 to provide the apparatus 10, and an operator thereof, additional information regarding the condition of a tire 13 that is to be loaded with the pulverulent material. Also, as is shown in phantom at 164, the peripheral driver board 150 may be selectively connected to an electronic analysis instrument, such as a laptop computer 164, through a connection such as an RS-232 serial port, for a service technician to monitor the performance of each workstation 14 and the mainframe 12.
While the input/output to the above described components is carried out through the peripheral driver board 150, the control of these various functions is provided by a microcontroller 170 such as a Motorola 68HC11 microcontroller or another similar computer chip. The microcontroller 170 receives electrical power through a connection 172 from peripheral driver board 150, exchanges serial data with peripheral driver board 150 through an RS-232 connection 174, receives analog data from peripheral driver board 150 through connection 176, exchanges digital input/output data with peripheral driver board through connection 178, and exchanges serial data with peripheral driver board 150 through an RS-485 connection 182. A reset connection 177 and an expansion bus connection 180 are also provided. Workstation 14 also includes a reset switch 184, which is preferably of the key activated type for security purposes, connected to board 150 to reset workstation 14 as may be required. Each workstation 14 also includes a unique computer "address", which may be varied through the use of jumpers or the like. In this manner, communication between each workstation 14 and the mainframe 12 is capable along a common data bus 20 as described. For example, the address information allows the mainframe to determine which workstation 14 is requesting pulverulent material, and which workstation 14 is sending any other data to the mainframe 12. Also, the unique address allows the mainframe 12 to communicate data to a particular workstation 14 by including that workstation's address as a part of the data.
The above described apparatus 10, can carry out a variety of operations including, beading a tire 13, deflating a tire 13 to a predetermined air pressure, inflating a tire 13 to a predetermined air pressure, introducing a pulverulent material into a tire 13, and others. The operator of a workstation 14 may depress different keys and combinations thereof on workstation keyboard 152 to select a particular machine operation. The particular keys used to select each operation may vary, although the workstation display 154 will ordinarily prompt a workstation operator to press one or more keys depending upon the operation desired. For example, the video display 154 of a workstation 14 may present the operator with three main choices: 1) Perform a Tire Runout Test; 2) Bead/Inflate a Tire; and 3) Load a Tire (by introducing pulverulent material into the tire). The operations may be carried out, for example, as follows:
Runout Test
To perform a tire runout test, an operator of a workstation 14 positions a runout sensor 162 adjacent to a tire 13 (or in contact therewith, depending upon the type of sensor). The operator depresses the appropriate key(s) on workstation keyboard 152 to begin the testing procedure. The operator then rotates the tire 13 (which may be rotatably mounted on an elevated vehicle or a tire changing machine). The runout sensor 162 will communicate data to the workstation peripheral driver board 150 regarding the radial and/or lateral runout of the tire 13 and the same information may be displayed on workstation display 154 for viewing by an operator.
Beading a Tire
To bead a tire 13 at a workstation 14 (the workstation 14 may be combined with a tire changing apparatus), or to inflate a tire 13 to its operating pressure, an air chuck 128, preferably including an air pressure sensor 160, is connected to the tire valve stem of the tire 13. The operator presses the appropriate key(s) on workstation keyboard 152 as indicated on workstation display 154 to select the beading operation. The workstation display 154 prompts the operator to enter a predetermined tire pressure desired for the beading or filling operation (usually the maximum allowed pressure for the tire). Once the operator enters this information, the tire 13 will begin to fill with compressed air.
Specifically, the workstation microcontroller 170 informs the mainframe controller 110 that a tire 13 is about to be inflated at the workstation 14. This information and the information discussed below, including the address of the workstation 14, is sent from the workstation 14 to the mainframe 12 over the data bus 20. The workstation controller 170 then causes its respective distribution pinch valve 70a-70h (corresponding to workstations 14a, 14b) or additional workstations to close. Closing the appropriate distribution pinch valve 70a-70h is important to prevent compressed air from the workstation 14 from traveling back to the mainframe 12 and disrupting other operations that might be occurring with respect to other workstations 14. Closing the distribution pinch valve 71a-71h of each workstation 14 effectively isolates the pneumatics of the workstation 14 from the pneumatics of the mainframe 12.
The workstation controller 170 next causes the workstation solenoid valve 124 (FIG. 5) to open to its second position, thereby allowing fluid communication of compressed air from source 26 to the tire 13. The workstation controller 170 monitors the air pressure within the tire 13 using data received from air pressure sensor 160. When the air pressure within the tire 13 reaches the predetermined value previously input by the machine operator, the workstation controller 170 causes workstation solenoid valve 124 to close, thereby blocking further communication of compressed air from source 26 into tire 13. The operator may then disconnect the air chuck 128 from the tire valve stem of the tire 13. The workstation controller 170 then notifies the mainframe 12 (again by transmitting data over the data bus 20) that the beading/inflation operation is complete.
Introducing Pulverulent Material into a Tire
Once a newly mounted tire 13 has been beaded the operator of the apparatus 10 may choose to introduce a predetermined amount of pulverulent material into the tire 13. This operation may also be performed on a tire 13 that has not been recently mounted, but instead has been in use. It is ordinarily preferable to remove the valve core from within the valve stem to facilitate the introduction of the pulverulent material into the tire 13. The air chuck 128, including the tire air pressure sensor 160, is connected to the tire valve stem of the tire 13 (or is already connected due to a just completed beading operation). The operator may then depress the appropriate key(s) on workstation keyboard 152 to select the loading/balancing procedure as indicated on workstation display 154. In response to the operator's entered request, the tire 13 will first be deflated or "bled" to some fraction of its ordinary or maximum operating air pressure. It is thought preferable to bleed a tire 13 down to 15%-30% of its maximum rated operating pressure. The workstation controller 170 calculates this value based upon the maximum rated tire pressure keyed in by the operator of the apparatus 10. Of course, the tire may be manually bled if desired.
In order to partially deflate the tire 13, the workstation controller 170 closes workstation solenoid valve 124 and causes its respective distribution pinch valve 70a-70h in mainframe 12 to be closed by applying the appropriate signal on common data bus 20 to pneumatically isolate the workstation 14 from the mainframe 12 as described (these valves will be caused to close automatically by the workstation controller 170 upon the connection of the air chuck 128 to an inflated tire 13 as sensed by air pressure sensor 160). The workstation 14 then informs the mainframe 12, through the data bus 20, that a tire 13 is being deflated. The workstation controller 170 then causes workstation solenoid valve 124 to open to its first position, allowing fluid communication from tire 13 to compressed air exhaust outlet 28. The workstation controller 170 continues to monitor the air pressure within the tire 13 during the deflation process through data received from air pressure sensor 160 of air chuck 128. When tire 13 has been deflated to 30% (or some other predetermined fraction) of its rated tire pressure, the workstation controller 170 causes workstation solenoid valve 124 to close, thereby preventing any further communication of compressed air from tire 13 to compressed air exhaust outlet 28. The workstation controller 170 then notifies the mainframe 12 through the data bus 20 that the tire 13 is ready to receive an application of the pulverulent material. In the example shown, only one workstation 14 may be serviced by mainframe 12 at any one time. If a workstation 14 is being serviced when the mainframe receives another workstation request, the additional request is put onto a stack or into a queue or is otherwise put on hold. Also, those skilled in the art will recognize that mainframe 12 may be provided with more than one cylinder 56 and the other components discussed above such that multiple tires may be loaded with pulverulent material at any one time.
As is best seen in FIGS. 2 and 3, when the mainframe controller 110 is prepared to dispense the pulverulent material from hopper 50, it closes the workstation distribution pinch valves 70a-70h and the purge valve 72. As discussed previously, this is accomplished by energizing the pilot valves 71a-71h, and 73, thereby allowing the relatively higher pressure air from second air pressure regulator 32 to close the pinch valves 71a-71h, and 72. The mainframe controller 110 opens pinch valves 62,74 and closes both mainframe solenoid valves 40,42.
The mainframe controller takes a reference "zero" reading of weight of cylinder 56 on load cell 105. This reference value is used to determine the amount of pulverulent material that is dispensed into the cylinder 56. The mainframe controller 110 then opens solenoid valve 40 to venturi 52, creating a vacuum force in cylinder 56 as described and causing the pulverulent material from hopper 50 to enter cylinder 56 through pneumatic fitting 61, tubing 60 and input orifice 59. During this time, the mainframe controller 110 continuously monitors the output data from load cell 105 to calculate the increasing weight of pulverulent material in the cylinder 56. Also, as is described above, upon the opening of solenoid valve 40, pilot valve 41 is also opened such that compressed air from regulator 32 is directed through conduit 43 into hopper 50 in the area below diffuser 51 to create an admixture or "cloud" of pulverulent material P and compressed air within hopper 50. Additionally, the exhaust air flow from venturi 52 is directed through conduit 54 and pinch valve 74 into hopper 50 to further "stir" the admixture while the pulverulent material P is withdrawn through fitting 61. Those skilled in the art will recognize that the excess air pressure within hopper 50 will be vented through orifice 152 and vent 156, with filter 159 preventing the exit of pulverulent material P. When the cylinder 56 contains the predetermined weight of pulverulent material, the mainframe controller 110 first closes pinch valve 62 to allow tubing 60 between pinch valve 62 and cylinder 56 to be emptied. After a brief delay, the mainframe controller closes solenoid valve 40, pilot valve 41, and finally pinch valve 74.
With a predetermined amount of pulverulent material contained within the cylinder 56, the mainframe controller 110 closes all workstation distribution pinch valves 70a-70h, purging pinch valve 72, venturi exhaust pinch valve 74, and vacuum line pinch valve 62. The mainframe controller 110 also causes the first and second mainframe solenoid valves 40,42 to close. The mainframe controller 110 communicates the completion of the above to the workstation controller 170. The workstation controller 170 then causes the workstation solenoid valves 124,130 to close, and gives control of its workstation distribution pinch valves 70a-70h to the mainframe controller 110. The mainframe controller 110 then opens the proper one of distribution pinch valves 70a-70h corresponding the workstation 14 where the pulverulent material is to be distributed. The mainframe controller 110 next opens solenoid valve 42 to allow direct fluid communication between first air pressure regulator 30 and cylinder 56 through pneumatic tubing 55 and pressure variation orifice 64 of cylinder 56. The opening of solenoid valve 42 causes a high pressure condition within cylinder 56, relative to the air pressure within tire 13, which also causes the pulverulent material therein to form a swirling or turbulent admixture with the compressed air and exit cylinder 56 through exit orifice 69 formed through lower bulkhead 66 of cylinder 56 and travel into conduit 68. The admixture of pulverulent material and compressed air in conduit 68 will naturally travel to the distribution conduit 22a-22h having an open distribution pinch valve 70a-70h. As is shown in FIGS. 8A and 8B, the connections between conduit 68 and the various workstation distribution conduits 22a-22h, may be staggered in a stair-step or similar fashion to facilitate the flow of the pulverulent material into the distribution tubing 22a-22f having the open pinch valve 70a-70f. As is shown most clearly in FIG. 4, the distribution tube 22a connects with interior of tire 13 through tubing 24 and air chuck 128, allowing the admixture of pulverulent material and compressed air to enter tire 13 through the valve stem thereof. Mainframe check valve 44 (FIG. 2) prevents migration of pulverulent material from tubing 55, venturi 52, or tubing 53 into solenoid valve 40 when solenoid valve 42 is opened.
The mainframe controller 110 continually receives data from the load cell 105 through its connection 106 with mainframe peripheral driver board 100 to thereby monitor the amount of pulverulent material in the cylinder 56 during the evacuation thereof. When the mainframe controller 110 determines that at least substantially all of the pulverulent material has been evacuated from the cylinder 56, it delays for a short period of time, such as 1-2 seconds, to ensure that all of the pulverulent material has entered the tire 13. The mainframe controller 110 then closes the one previously opened workstation distribution pinch valve 70a-70h and the mainframe solenoid valve 42. The mainframe controller 110 then informs the workstation controller 170 (by sending out the appropriate signal on data bus 20) that it has completed the distribution of pulverulent material to that workstation 14. The workstation controller 170 once again seizes control of its respective distribution pinch valve 70a-70h, ensuring that it closes (and remains closed). The mainframe controller 110 opens the venturi exhaust pinch valve 74 to relieve any pressure in the cylinder 56, and after a slight delay of 1-2 seconds, the mainframe controller 110 then opens all distribution pinch valves 70a-70h (except those forced closed by a workstation 14), the vacuum line pinch valve 62, and the purge line pinch valve 72.
A purging operation is identical to the above-described distribution operation, except that the purge line pinch valve 72, rather than one of the workstation distribution pinch valves 70a-70h is opened, causing the pulverulent material evacuated from the cylinder 56 to be routed back into the hopper 50. This is required, for example, if it is necessary to abort a dispensing or distribution operation for any reason. For example, if an incorrect amount of pulverulent material is vacuumed into the cylinder 56, the pulverulent material may simply be evacuated therefrom into the hopper 50 through purge line 23. If the dispensing/distribution operation takes longer than a predetermined amount of time (indicating an error) the purge function will occur to evacuate the cylinder 56.
Those skilled in the art will recognize that the foregoing description has set forth the preferred embodiment of the invention in particular detail and it must be understood that numerous modifications, substitutions and changes can be undertaken without departing from the true spirit and scope of the present invention as defined by the ensuing claims. | An apparatus for introducing a pulverulent material into a tire of a wheel assembly, through the valve stem thereof, without a large amount of operator time, effort, or intervention. The apparatus includes two main types of components--the mainframe component and one or more workstation components. Each workstation component serves as a location from which an operator of the apparatus introduces the pulverulent material into a tire and the mainframe component includes the a container for confining a predetermined amount of the pulverulent material and includes the other components required to dispense the pulverulent material into the container from a hopper or the like, and to evacuate the pulverulent material from the container and distribute the same out to a workstation through a suitable conduit where the pulverulent material is introduced into a tire. A method of introducing pulverulent material into a tire is also described. | 1 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is related to a fan frame device and particularly to a fan frame, which provides a plastic frame member and a metal reinforcing member.
[0003] 2. Brief Description of the Related Art
[0004] The fan is an essential part of air-cooling radiator device and plays an important role for heat dissipation effect. The fan is the only movable part in the radiator device. Meanwhile, noise of the radiator device is influenced directly by the fan. The fan induces air to move through the cooling fins with a specific speed and a specific way for heat exchange being performed between the air and the cooling fins such that accumulated heat at the cooling fins can be carried away to achieve heat removal with forced convection.
[0005] Air flow and air pressure are factors deciding how powerful a fan is. The air flow refers a product of an area of the air passing through and a velocity of the air passing through the area. When the velocity is constant, larger outer diameter of the fan wheel leads to larger flowing area and more air flow can be induced. More air flow allows the cool air absorbs more heat so that the moving air can carry with more heat and effect of heat dissipation is enhanced. The air pressure refers addition of a static pressure and a dynamic pressure of the air so that greater air pressure enhances air-delivering capability of the fan.
[0006] In order to promote the gross effect of heat dissipation, the big sized fan has been employed to enhance heat dissipation efficiency. However, due to space limitation, not all the cooling systems are able to use the big sizes fan even if the smaller sized fan is unable to reach the expect effect of heat dissipation.
[0007] The inventor has found that if the inner side of the fan frame, i.e., the flow path of air, is increased radially under a condition of the size of the fan frame being unchanged, that is, the material between the outer side and the inner side becomes thinner. In other words, the air inlet and the air outlet areas can be increased and a bigger size fan wheel can be mounted to the inner side for generating more air flow.
[0008] Further, the inventor has found that most part of a fan frame is made of plastics and a little part of the fan frame is made of metal. The fan frame with plastic material is light but the strength thereof becomes weak in case of the fan frame being made thinner. The plastic fan frame is easy to become deformed in case of being subjected to a fore and to become soft in case of being subjected to a high ambient temperature for a long period of time. As a result, normal operation of the fan is affected substantially.
[0009] The metal fan frame provides enough strength but it is heavy and easy to produce louder noise while the air passing the fan frame to hit the inner wall of the fan frame. In addition, the metal fan frame is more costly than the plastic fan frame and manufacturing process of the metal fan frame is more complicated than the plastic fan frame.
SUMMARY OF THE INVENTION
[0010] In order to solve the preceding problems, an object of the present invention is to provide a fan frame device with which the inner side of the fan frame member expands toward the outer side thereof to the most for the flow path thereof being able to accommodate a fan wheel with a bigger diameter and promoting heat dissipation effect.
[0011] Another object of the present invention is to provide a fan frame structure in which the fan frame is composed of a plastic frame member and a metal reinforcing member for strengthening the fan frame and lessening noise and vibration.
[0012] Accordingly, the fan frame device according to the present invention includes a plastic frame member and a metal reinforcing member. The frame member has an outer side and an inner side. The inner side of the frame member defines a flow path for accommodating a fan wheel. The metal reinforcing member is joined to the frame integrally. The inner side of the frame is arranged to have a largest diameter so that the flow path provides more space for accommodating a larger size fan wheel. Hence, strength of the frame is reinforced, vibration and noise are reduced during a fan wheel running and integral effect of heat dissipation is enhanced largely.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The detail structure, the applied principle, the function and the effectiveness of the present invention can be more fully understood with reference to the following description and accompanying drawings, in which:
[0014] FIG. 1 is a perspective view of the first embodiment of a fan frame device according to the present invention;
[0015] FIG. 2 is a fragmentary sectional view along line A-A of FIG. 1 ;
[0016] FIG. 3 is a perspective view illustrating a metal reinforcing member being disposed between the inner side and the outer side of the first embodiment of a fan frame according to the present invention;
[0017] FIG. 4 is a perspective view of the metal reinforcing member being disposed at the outer side of the first embodiment of a fan frame device according to the present invention;
[0018] FIG. 5 is a plan view of the first embodiment of a fan frame device according to the present invention illustrating the first type discontinuously shaped metal reinforcing member;
[0019] FIG. 5A is an enlarged view of the dashed circle area of FIG. 5 ;
[0020] FIG. 6 is another plan view of the first embodiment of a fan frame device according to the present invention illustrating the second type discontinuously shaped metal reinforcing member;
[0021] FIG. 7 is a further plan view of the first embodiment of a fan frame device according to the present invention illustrating the third type discontinuously shaped metal reinforcing member;
[0022] FIG. 7A is an enlarged view of the dashed circle area of FIG. 5 ;
[0023] FIG. 8 is a perspective view illustrating the fourth type discontinuously shaped metal reinforcing member of the first embodiment of a fan frame device according to the present invention;
[0024] FIG. 9 is a perspective view illustrating two fan wheels being mounted in series to the first embodiment of a fan frame device according to the present invention;
[0025] FIG. 10 is a perspective view illustrating the first type arrangement of the second embodiment of a fan frame device according to the present invention;
[0026] FIG. 11 is a perspective view illustrating the second type arrangement of the second embodiment of a fan frame device according to the present invention;
[0027] FIG. 12 is a perspective view illustrating the third type arrangement of the second embodiment of a fan frame device according to the present invention;
[0028] FIG. 13 is a perspective view illustrating the metal reinforcing member in the first type arrangement of the second embodiment of a fan frame device according to the present invention shown in FIG. 10 providing ventilating apertures;
[0029] FIG. 14 is a perspective view illustrating the second type arrangement of the second embodiment of a fan frame device according to the present invention shown in FIG. 11 providing air apertures;
[0030] FIG. 15 is a perspective view illustrating the third type arrangement of the second embodiment of a fan frame device according to the present invention shown in FIG. 12 providing air apertures;
[0031] FIG. 16 is a diagram illustrating characteristics of the fan with fan frame of the invention and the conventional fan frame in a way of air pressure curves with respect to flow rate; and
[0032] FIG. 17 is a diagram illustrating characteristics of the fan with fan frame of the invention and the conventional fan frame in a way of noise curves with respect to fan speed.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Referring to FIGS. 1 and 2 , the first embodiment of a fan frame device according to the present invention provides a frame member 11 , which has an inner frame side 111 and an outer frame side 112 . The inner frame side 111 defines a flow path 113 for receiving a fan wheel 12 . An inlet 114 and an outlet 115 of the flow path 113 are formed at the front side and the rear side of the frame member 11 respectively. The outer frame side 112 defines the size of the frame member 11 . The frame member 11 is made of plastics and integrally joined to a metal reinforcing member 13 as a single piece by means of, for instance, the plastic frame member 11 being joined to the metal reinforcing member 13 preset in a molding tool during injection molding being performed.
[0034] The plastic frame member 11 provides a gross volume greater than the metal reinforcing member 13 . Each of the four sides of the frame member 11 provides the shortest distance between the frame inner side 111 and the frame outer side 112 , that is, spots a, b, c, d indicated by an arrow respectively are the shortest distances between the frame inner side 111 and the frame outer side 112 such that the inner side 111 expands radially to the most. That is, dimension of the outer side 112 is the same as the conventional fan frame but the inner side 11 provides a diameter greater than that of the conventional fan frame such that the spots a, b, c, and d are thinnest areas of the frame member 11 .
[0035] The preceding metal reinforcing member 13 can be disposed next to the frame inner side 111 to face the fan wheel 12 as shown in FIG. 1 after the plastic frame 11 being joined to the metal reinforcing member 13 . In other words, the inner side 111 is the metal reinforcing member 13 .
[0036] Referring to FIG. 3 , the metal reinforcing member 13 can be disposed between the frame inner side 111 and the frame outer side 112 and exposes at the four thinnest areas a, b, c and d. That is, the thinnest areas a, b, c and d are formed by the metal reinforcing member 13 . Referring to FIG. 4 , the metal reinforcing member 13 can be disposed at the frame outer side 112 , that is, the metal reinforcing member 13 constitutes the frame outer side 112 .
[0037] The preceding metal reinforcing members 13 are belonged to annular type metal reinforced members 13 . It is noted that discrete type metal reinforcing member 13 can be employed except the preceding annular type.
[0038] Referring to FIGS. 5 and 5 A, the metal reinforcing member 13 is belonged to discrete type. The metal reinforcing member 13 is composed of a pair of metal reinforcing member parts and the two metal reinforced member parts are fixedly joined oppositely at the thinnest areas (a, b) and (c, d) respectively without exposure. Next, referring to FIG. 6 , the metal reinforcing member parts are fixedly joined oppositely to the frame member 11 and expose at the thinnest areas (a, b) and (c, d) respectively. That is, the metal reinforcing member 13 constitute the thinnest areas a, b, c and d. Further, referring to FIGS. 7 and 7 A, the metal reinforcing member 13 is composed of two pair of metal reinforcing member parts and the four metal reinforced member parts are fixedly joined at the four thinnest areas (a, b, c and d respectively without exposure. Further, referring to FIG. 8 , the metal reinforcing member parts are fixedly joined to frame member 11 and expose at the thinnest areas (a, b) and (c, d) respectively. That is, the metal reinforcing member 13 constitute the thinnest areas a, b, c and d.
[0039] Referring to FIG. 9 , two fan wheels 12 are capable of being arranged in series in the frame 11 instead of a single fan wheel 12 in the first embodiment. Of course, it is feasible that more than two fan wheels 12 in series are arranged in the frame member 11 in case of enough space being available in the frame 11 .
[0040] Referring to FIGS. 10 to 15 , the second embodiment of a fan frame device according to the present invention is illustrated. The entire structure and functions of the second embodiment is almost the same as the preceding embodiment. The difference of the second embodiment from the preceding embodiment is in that the metal reinforcing member 13 provides a shape the same as the frame member 11 and is disposed next to the inlet 114 as shown in FIG. 10 , next to the outlet 115 as shown in FIG. 11 or between the inlet 114 and the outlet 115 as shown in FIG. 13 . It is noted that the frame member 11 is divided into two portions and the metal reinforcing member 13 is sandwiched by the two portions of the frame member 11 .
[0041] Referring to FIGS. 13 to 15 , the metal reinforcing member 13 in FIG. 13 is almost the same as that shown in FIG. 10 , the metal reinforcing member 13 in FIG. 14 is almost the same as that shown in FIG. 11 and the metal reinforcing member 13 shown in FIG. 15 is almost the same as that shown in FIG. 12 . The difference of the metal reinforcing member 13 shown in FIGS. 11 to 13 respectively from that shown in FIGS. 10 to 12 is in that a plurality of apertures 131 are provided at the lateral sides of the metal reinforcing member 13 for admitting fluid and increasing air flow induced by the fan.
[0042] Furthermore, the metal reinforcing member 13 in the preceding embodiments can be made of high strengthen compound material such as polymeric fiber and/or carbon fiber and/or plastic fiber and/or carbon-plastic fiber instead of metal.
[0043] Referring to FIG. 16 , curve of the air pressure in relation to flow rate is for the fan F 1 , which provides the fan frame of the present invention, and curve of the air pressure in relation to flow rate is for the fan F 2 , which provides the conventional fan frame. Due to the diameter of the inner side in the fan frame of the present invention is greater than that of the conventional fan frame and a bigger sized fan wheel is able to be mounted to the fan frame of the present invention, the air pressure induced by the fan F 1 is greater than that induced by the fan with the conventional fan frame under a condition of the same flow rate and, by the same token, the air flow of the fan F 1 is greater than that of the fan with the conventional fan frame under a condition of the same air pressure. Hence, entire fan characteristics of the fan F 1 are much higher than those of the fan F 2 .
[0044] Referring to FIG. 17 , curve of noise in relation to fan speed for the fan F 1 provides the fan frame of the present invention and curve of noise in relation to fan speed for the fan F 2 provides the conventional fan frame. Taking a range of fan speed between 6,000 rpm and 16,000 rpm for explanation, it can be seen the noise of the fan F 1 is between 23 dBA and 45 dBA but the noise of the fan F 2 is between 26 dBA and 49 dBA. That is, the fan F 1 generates lower noise than the fan F 2 because of the fan frame of the present invention is composed of a plastic frame and a metal member.
[0045] As the foregoing, it is appreciated that comparing to the prior art, the fan frame structure of the application has the following advantages:
[0046] 1. The plastic frame member 11 is joined to the metal reinforcing member 13 , which also can be made of compound material, intimately for lessening noise generated from the fluid impacting the frame member 11 and diminishing consonant vibrations during the fan wheel 12 running in addition to intensifying strength thereof.
[0047] 2. The frame member 11 is integrally joined to the metal reinforcing member 13 or the compound member provides higher strength such that the inner side 111 of the frame member 11 can be arranged to expand radially and outwardly toward the outer sides 112 to the most to obtain the bigger diameter of the inner side 111 than the prior art. In this way, the inlet and outlet of the frame member 11 becomes larger and more flow rate and higher air pressure can be obtained. Further, the flow passage 113 surrounded by the inner side 111 becomes more space for accommodating larger fan wheel 12 and increasing the flow rate.
[0048] 3. The thinnest spots a, b, c and d of the frame member 11 can be obtained once the inner side of the frame member 11 expands radially toward the outer sides 112 to the most under support of the metal frame 15 . Hence, it is capable of overcoming the deficiency of the conventional plastic fan frame providing insufficient strength and being easily deformed after being subjected to heat for a long period of time.
[0049] 4. Due to the volume of the plastic frame member 11 is more than that of the metal reinforcing member 13 , the entire fan frame of the present invention is lighter than the conventional metal fan frame so that not only the cost of the fan frame can be lowered but also it is capable of overcoming the problems of noise and vibrations, which the conventional metal fan frame is unable to breakthrough.
[0050] While the invention has been described with referencing to preferred embodiments thereof, it is to be understood that modifications or variations may be easily made without departing from the spirit of this invention, which is defined by the appended claims. | A fan frame device includes a plastic frame member and a metal reinforcing member. The inner side of the frame defines a flow path for receiving a fan wheel. The metal reinforcing member is joined to the frame member integrally. The inner side of the frame is arranged to have a largest diameter so that the flow passage provides more space for accommodating a larger sized fan wheel. Hence, strength of the frame is reinforced, vibration and noise are reduced during a fan wheel running and integral effect of heat dissipation is enhanced largely. | 5 |
[0001] This application is a divisional of pending prior application Ser. No. 10/754,454, filed Jan. 9, 2004, which is a continuation-in-part of Application Ser. No. 29/186,712, filed Jul. 21, 2003, now U.S. Pat. No. D501,935 S, issued Feb. 15, 2005, the contents of each of which are hereby incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to retaining wall blocks and a method for making these blocks.
BACKGROUND OF THE INVENTION
[0003] Numerous methods and materials exist for the construction of retaining walls. Such methods include the use of natural stone, poured in place concrete, masonry, and landscape timbers or railroad ties. In recent years, segmental concrete retaining wall units which are dry stacked (i.e., built without the use of mortar) have become a widely accepted product for the construction of retaining walls. Such products have gained popularity because they are mass produced, and thus relatively inexpensive. They are structurally sound, easy and relatively inexpensive to install, and couple the durability of concrete with the attractiveness of various architectural finishes.
[0004] It is desirable to build a wall from such blocks quickly and without the need for special skilled labor. The efficiency of building a wall can be measured by determining how fast the front face of a wall is constructed. Clearly, this depends on the size of the blocks used and ease of stacking the blocks.
[0005] It is standard practice in the prior art to use similarly sized mold boxes to produce various styles of block. For example, a standard size box has a block molding area of about 18 inches by about 24 inches (about 45.7 cm by about 61 cm), and produces a block about 8 inches (20.3 cm) thick. FIG. 1A illustrates retaining wall block B 1 in mold box M. This block is symmetrical about a centrally located vertical plane of symmetry. Block B 1 has pin holes PH, pin receiving cavities PC, and two cores C 1 and C 2 . The sides generally converge from the front to the back of the block. Front face F is produced by the removal of waste portion W after the block has formed. This portion is split off to form a roughened surface. The block of FIG. 1A is manufactured one block at a time so that the yield per cycle is one square foot (1 sq ft or 929 sq cm) of front face. A typical weight for this block is about 110 lbs (50 kg).
[0006] Other prior art blocks are shown in FIGS. 1B and 1C in mold box M. This block is similar to that described in WO 02/101157 (MacDonald et al.). This block also has similarities to block B 1 , as it is symmetrical about a centrally located vertical plane of symmetry. Block B 2 has pin holes PH, pin receiving cavities PC, and core C. Preferably, the blocks are formed so that front face F will have a roughened appearance. Block B 2 is made in a mold box two at one time. This provides a good use of mold space, producing about two square feet (1858 sq cm) of front face per manufacturing cycle. FIG. 1B illustrates that the blocks can be formed two at a time and separated at the back faces. In this case, the front surface of the block is textured by texturing elements T that contact the front surface as the block is removed from the mold box. FIG. 1C shows blocks that are molded together at front face F. The front faces of these blocks will be separated, or split apart after curing. The splitting of such blocks is used to form the desirable surface appearance. When manufactured in this manner, each block has a front face of about one square foot (1 sq ft or 929 sq cm). Thus, the yield per cycle is two square feet of front face. A typical weight for this block is about 85 lbs (38.6 kg).
[0007] A third type of prior art block in its mold box M is shown in FIG. 1D . Block B 3 is a rectangular block, shown having two cores or cavities C. The long dimension of the block typically is used to form the face of a wall. Thus, this type of block produces a useful front surface about 24 inches long, rather than the 18 inch long surface of blocks B 1 and B 2 . The surface area (for the same thickness block, i.e., about 8 inches) is about 33% greater than the surface area of blocks B 1 or B 2 . However, this block weighs about 250 lbs (113.6 kg) and must be set in place using mechanized means.
[0008] Accordingly, a need in the art remains for wall blocks that make the most use of a mold box's area while producing a block with a large front surface area.
SUMMARY OF THE INVENTION
[0009] The present invention is a mold box and a method of making a wall block that maximizes the use of the mold box and produces wall blocks having a large surface area front face that are lightweight and easy to handle when constructing a wall. This results in faster construction of walls and a faster construction sequence, because for each block, the front face surface area is larger than blocks known in the art. The method of making the blocks makes efficient use of mold space and material, resulting in higher production yields and/or higher total daily production square footage.
[0010] In one aspect, this invention is a mold box for making first and second wall blocks comprising first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold cavity, the first and second end rails being spaced apart a distance d 1 , the first and second side rails being spaced apart a distance d 2 which is less than distance d 1 ; and a divider plate having a first end connected to the first end rail and a second end connected to the second end rail, the divider plate dividing the mold cavity into a first mold section for forming the first block and a second mold section for forming the second block.
[0011] In another aspect, this invention is a mold box for making first and second wall blocks comprising first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold cavity, the first and second end rails being spaced apart a distance d 1 , the first and second side rails being spaced apart a distance d 2 which is less than distance d 1 ; and a divider plate having a first end connected to the first end rail and a second end connected to the second end rail, the divider plate dividing the mold cavity into a first mold section for forming the first block and a second mold section for forming the second block, the first mold section being configured such that a front face of the first block is formed adjacent the first side rail, the second mold section being configured such that a front face of the second block is formed adjacent the second side rail.
[0012] In another aspect, this invention is a mold box for making first and second wall blocks comprising first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold cavity, the first and second end rails being spaced apart a distance d 1 , the first and second side rails being spaced apart a distance d 2 which is less than distance d 1 ; and a divider plate having a first end connected to the first end rail and a second end connected to the second end rail, the divider plate dividing the mold cavity into a first mold section for forming the first block and a second mold section for forming the second block, the first mold section being configured such that a front face of the first block is formed adjacent the first side rail, the second mold section being configured such that a front face of the second block is formed adjacent the second side rail, the divider plate being shaped in a non-planar configuration such that a maximum first block depth measured between the first side rail and the divider plate along a line generally perpendicular to the first side rail is greater than d 2 /2 and a maximum second block depth measured between the second side rail and the divider plate along a line generally perpendicular to the second side rail is greater than d 2 /2.
[0013] In another aspect, this invention is a method of making wall blocks comprising providing a mold box having first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold cavity, the first and second end rails being spaced apart a distance d 1 , the first and second side rails being spaced apart a distance d 2 which is less than distance d 1 ; dividing the mold cavity into a first mold section for forming a first block and a second mold section for forming a second block, the first mold section being configured such that a front face of the first block is formed adjacent the first side rail, the second mold section being configured such that a front face of the second block is formed adjacent the second side rail; filling the first and second mold sections with a desired block material; and removing the block material from the first mold section to form the first block and from the second mold section to form the second block, the first block having a maximum depth measured between the front face and a rear face along a line generally perpendicular to the front face which is greater than d 2 /2 and the second block having a maximum depth measured between the front face and a rear face along a line generally perpendicular to the front face which is greater than d 2 /2.
[0014] In another aspect, this invention is a method of making wall blocks comprising providing a mold box having first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold cavity, the first and second end rails being spaced apart a distance d 1 , the first and second side rails being spaced apart a distance d 2 which is less than distance d 1 ; dividing the mold cavity into a first mold section for forming a first block and a second mold section for forming a second block, the first mold section being configured such that a front face of the first block is formed adjacent the first side rail, the second mold section being configured such that a front face of the second block is formed adjacent the second side rail; filling the first and second mold sections with a desired block material; and removing the block material from the first mold section to form the first block and from the second mold section to form the second block, the front faces of the first and second blocks each having a length approximately equal to d 1 .
[0015] In another aspect, this invention is a method of making wall blocks comprising providing a mold box having first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold cavity, the first and second end rails being spaced apart a distance d 1 , the first and second side rails being spaced apart a distance d 2 which is less than distance d 1 ; connecting a divider plate between the first and second end rails to divide the mold cavity into a first mold section for forming a first block and a second mold section for forming a second block, the first mold section being configured such that a front face of the first block is formed adjacent the first side rail, the second mold section being configured such that a front face of the second block is formed adjacent the second side rail; filling the first and second mold sections with a desired block material; and removing the block material from the first mold section to form the first block and from the second mold section to form the second block.
[0016] In another aspect, this invention is a method of making wall blocks comprising providing a mold box having first and second opposed end rails and first and second opposed side rails, the end rails and side rails together forming a mold cavity, the first and second end rails being spaced apart a distance d 1 , the first and second side rails being spaced apart a distance d 2 which is less than distance d 1 ; connecting a divider plate between the first and second end rails to divide the mold cavity into a first mold section for forming a first block and a second mold section for forming a second block, the first mold section being configured such that a front face of the first block is formed adjacent the first side rail, the second mold section being configured such that a front face of the second block is formed adjacent the second side rail, the divider plate being non-planar and having a first mold surface and a second mold surface, a rear face of the first block being formed adjacent the first mold surface and a rear face of the second block being formed adjacent the second mold surface, the divider plate being configured such that the rear faces of the first and second blocks overlap when they are formed in the mold cavity; filling the first and second mold sections with a desired block material; and removing the block material from the first mold section to form the first block and from the second mold section to form the second block.
[0017] In another aspect, this invention is a wall block comprising a front portion including opposed top and bottom surfaces, opposed side surfaces and a front surface, the front surface having a length equal to the distance between the side surfaces and a height equal to the distance between the top and bottom surfaces. The at least one leg extends from the front portion in a direction opposite the front surface and has a rear surface, a distance between the front surface and rear surface comprising a maximum block depth. The at least one leg is positioned such that when a plurality of the blocks including first and second blocks are packaged for shipment the first and second blocks can be positioned on a common surface with their front surfaces oriented in opposite directions with the at least one leg of the first block overlapping the at least one leg of the second block so that the first and second blocks occupy an area on the common surface which is less than the length of the front surface times twice the block depth.
[0018] In another aspect, the invention is a wall block comprising a front portion including opposed top and bottom surfaces, opposed side surfaces and a front surface, the front surface having a length equal to the distance between the side surfaces and a height equal to the distance between the top and bottom surfaces. The at least one leg extends from the front portion in a direction opposite the front surface and has a rear surface, the at least one leg being positioned such that when a wall is formed from multiple courses of the blocks which are offset from course to course by about one half the length of the front surface the legs in each course of blocks align vertically.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] FIG. 1A is plan view of the mold box configuration for a first Prior Art block. FIG. 1B is a plan view of a first mold box configuration for a second Prior Art block. FIG. 1C is a plan view of a second mold box configuration for a second Prior Art block. FIG. 1D is a plan view of a mold box configuration for a third Prior Art block.
[0020] FIG. 2 is a plan view of the configuration of the block of this invention in a mold box.
[0021] FIG. 3 is a perspective view of the block of this invention.
[0022] FIG. 4A is a top view and FIG. 4B is a bottom view of the block of FIG. 2 .
[0023] FIGS. 5A and 5B are side views of the block of FIG. 2 .
[0024] FIG. 6 is a back view of the block of FIG. 2 .
[0025] FIG. 7 is a perspective view showing stacked blocks of FIG. 2 .
[0026] FIG. 8A is a perspective view and FIG. 8B is a top view of another block of this invention.
[0027] FIG. 9 is a perspective view of another block of this invention.
[0028] FIG. 10 is a top view of the block of FIG. 9 .
[0029] FIG. 11 is a perspective view of another block of this invention.
[0030] FIG. 12 is a top view of a mating pair of the blocks of FIG. 11 .
[0031] FIGS. 13A and 13B are partial top views of a row of blocks comprising the blocks of FIGS. 9 and 11 .
[0032] FIG. 14 is a partial view of a wall of blocks constructed with the blocks of FIGS. 9 and 11 .
[0033] FIG. 15A is a bottom perspective view of another block of this invention.
[0034] FIG. 15B a top perspective view of stacked blocks of FIG. 15A .
[0035] FIG. 16 is a side view of the block of FIG. 15A .
[0036] FIG. 17 is a top view of another block of this invention.
[0037] FIG. 18 is a top view of two other blocks of this invention.
[0038] FIGS. 19A and 19B are partial cross sectional views of a block showing pin placement in a pin hole.
[0039] FIGS. 20A and 20B are cross sectional views of walls constructed from the blocks of this invention.
[0040] FIG. 21 is a perspective view of a mold box used to form the blocks of this invention.
[0041] FIG. 22A is a plan view of the mold box of FIG. 21 showing the divider plate and FIG. 22B is a plan view of the divider plate with the mold box and the blocks in phantom.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0042] In this application, “upper” and “lower” refer to the placement of the block in a retaining wall. The lower surface faces down, that is, it is placed such that it faces the ground. In forming a retaining wall, one row of blocks is laid down, forming a course. A second course is laid on top of this by positioning the lower surface of one block on the upper surface of another block.
[0043] The blocks of this invention may be made of a rugged, weather resistant material, such as concrete, especially if the wall is constructed outdoors. Other suitable materials include plastic, reinforced fibers, and any other materials suitable for use in molding wall blocks. The surface of the blocks may be smooth or may have a roughened appearance, such as that of natural stone. The blocks are formed in a mold and various textures can be formed on the surface, as is known in the art.
[0044] Several embodiments are illustrated in the figures below. In one embodiment, this invention is a block comprising a front portion having two legs extending therefrom. The two legs each have a core and a back portion and the back face of each back portion is the back of the block. The cores are optional and their positions can be varied. The legs are located asymmetrically on the block. The legs have sides that define the area of the core and the leg side walls generally converge from the front toward the back.
[0045] In another embodiment, this invention is a block similar to the block described above, except that one of the legs joins the front portion at right angles. This block is suitable for forming a corner structure.
[0046] In another embodiment, this invention is a block having one leg extending from the front face where the leg is located at one side of the front face.
[0047] In another embodiment, this invention is a block having multiple curvilinear legs, all legs extending away from the front surface.
[0048] The blocks of this invention may be provided with a connection means for connecting blocks in adjacent courses. The connection means may comprise pin holes and pin receiving cavities. The cavities in a second or top block accept the head of a pin placed in a pin hole of a first or bottom block. Alternatively, the bottom surface of this block may be provided with a channel configured to accept the head of a pin placed in a pin hole in an underlying block. The appearance of the front face of the block may be varied as desired.
[0049] The advantage to the design of blocks described herein is that the blocks provide good structural stability with a maximum amount of block front face and a minimum use of material. Not only are the blocks easy to handle, but the manufacture of the blocks is efficient in its use of space and material, which can be seen, for example, by the illustration of FIGS. 22A and 22B , discussed further below. The blocks are made by forming matching pairs of blocks in a single mold designed so that one or more legs on a first block interweave or overlap with one or more legs on a second block. In this way the blocks nest together. The length of the front face of the block is generally about twice the distance from the front of the block to the back face of a leg. This has been found to maximize the volume of mold space used. Molding the blocks in this manner is also an advantage when it comes to shipping the blocks since the blocks are removed from the mold, pallatized and shipped in the same overlapping or nested configuration. This overlapping configuration takes up less space and is easier to handle than blocks molded in a conventional manner. The depth of the block (i.e., the distance from front to back surfaces) is greater than half the mold box depth. It should be understood, however, that other lengths or dimensional relationships of the blocks can be used within the scope of the invention.
[0050] This block design maximizes the area of the front face of the block while minimizing the weight of the block. As a result, the block manufacturer is able to produce more wall area per manufacturing or mold cycle and gain greater yield of wall blocks per a given volume of raw materials while at the same time manufacturing the blocks in a configuration which saves space and is easy to handle and to ship. The wall installer is able to install more face area of wall each time a block is placed and the blocks generally weigh no more or just slightly more than prior art blocks having a smaller front surface area.
[0051] It is useful to compare the block of the present invention to prior art blocks, such as those illustrated in FIGS. 1A to 1D above. FIG. 2 shows the present inventive blocks 100 in a mold box. This figure can be compared directly with FIGS. 1A to 1D . The mold box illustrated is a standard size for the industry, about 18 by 24 inches, and produces a block about 8 inches thick. Blocks 100 each weigh about 95 lbs (43.2 kg). The front surface (F) of the block is the dimension of the long dimension of the mold box, i.e., about 24 inches. Thus this block has a larger surface area (24 by 8 inches, 192 sq in, or 1.33 sq ft) than the surface area (18 by 8 inches, 144 sq in, or 1 sq ft) of the prior art blocks shown in FIGS. 1A to 1C . This equals a 33% increase in front surface area. Yet the weight increases only about 11%, to 95 lbs from 85 lbs (43.2 to 38.6 kg), still a handleable weight.
[0052] In addition, an even greater manufacturing advantage is realized because the inventive blocks are made two at a time. Thus, one production cycle produces 2.66 sq ft (2470 sq cm) of front surface area per manufacturing cycle. This compares to the production of one sq ft for Prior Art block B 1 , two sq ft for Prior Art block B 2 , and 1.33 sq ft. for Prior Art block B 3 . In addition, in all cases for the present block, the capacity of the mold box is maximized or at least increased substantially.
[0053] Various embodiments of the blocks of this invention are shown in the drawings.
[0054] FIGS. 3 to 7 illustrate block 100 . FIGS. 8A and 8B illustrate block 100 a , which is substantially similar to block 100 except that block 100 a has rounded corners and fewer pin holes. Similar features of these blocks will be referred to by the same numbers. Block 100 has parallel top face 102 and bottom face 103 . Front face 104 has optional bevel or chamfer 108 adjacent the top and sides of the block to provide a desirable appearance. The length of face 104 is defined by the distance between corners 106 and 107 . Extending from front portion 110 are two legs 120 and 130 . Cores 121 and 131 are located primarily in the legs, though they extend into front portion 110 . It should be noted that the shape of the cores as shown in the figures is a convenient shape for manufacturing, however, any suitable shape can be used. Legs 120 and 130 extend to rear portions 124 and 134 , respectively, having rear faces 125 and 135 , respectively.
[0055] Front face 104 and rear faces 125 and 135 each extend from top face 102 to bottom face 103 , as shown in FIG. 6 . The distance between faces 102 and 103 defines the thickness of the block.
[0056] Legs 120 and 130 are separated by void 140 . Each leg 120 and 130 has two side walls 122 , 123 and 132 , 133 , respectively. These side walls generally converge from the front to the back of the block. The side walls extend from top face 102 to bottom face 103 . In a preferred embodiment, legs 120 and 130 are positioned such that, when stacking blocks one on top of another in a wall, a leg of one block is placed over a leg in an underlying block and a running bond pattern is created. The alignment of legs is desirable because it adds to the structural stability of a wall, and also permits the introduction of vertical reinforcement or filler materials that would extend through the cores and voids of adjacent legs.
[0057] Side 111 of block 100 is shown in FIG. 5A and side 113 is shown in FIG. 5B . Side 111 comprises the side surfaces of leg side wall 122 and back portion 124 , and the side of front portion 110 . Side 113 , as shown in FIG. 5B , comprises the side surfaces of leg side wall 133 and back portion 134 , and the side of front portion 110 .
[0058] Front portion 110 ( FIG. 3 ) includes front face 104 and also includes pin holes 112 , 114 , 115 , and 116 and pin receiving cavities 117 and 118 ( FIG. 4A ).
[0059] It should be noted that the shape of the cores as shown in FIGS. 3 to 8 is a convenient shape for manufacturing, however, any suitable shape can be used. The cores serve to reduce the weight of the block. When a block is manufactured, a core is tapered from top to bottom to ease stripping the block from the mold, as known to one of skill in the art. Cores are optional but may be desirable since they reduce the amount of material required to make the block, and they allow more blocks to be shipped since weight is usually a constraint on how many blocks may be shipped at one time. In addition, a lower weight block is easier for those who handle the block when constructing a wall. Further, the size and shape of the legs and voids can be varied.
[0060] Pin receiving cavities 117 and 118 are positioned at any desired location along the front portion of the block and may have any desired shape. The placement of cavities in conjunction with pin holes 115 and 116 can be used to form a running-bond pattern in a wall of blocks. The pin receiving cavities may extend from the top to the bottom of the block, which aids in minimizing block weight, or may only partially extend toward the bottom of the block. However, they also could be depressions in the block rather than passageways.
[0061] Pin holes 112 , 114 , 115 and 116 extend from the top face 102 to bottom face 103 . Four pin holes are shown, but more or fewer pin holes may be used. The holes are tapered to ease the removal of forming elements from the molded block. These pin holes are sized to receive a connecting element, such as a pin.
[0062] The pin may be a shouldered pin, in which case the pin hole may be substantially the same diameter for the thickness of the block, or the pin holes may be truncated to allow a portion of a headless pin to sit above the surface of the block. Various pins are described further below.
[0063] Block 100 is shown stacked in a running bond pattern in FIG. 7 . These blocks are configured so that the back portion of a block above rests on at least a part of the back portion of the block below. Optimally, a leg of one block is placed on the leg of an underlying block. This adds stability to a wall formed from these blocks and increases the frictional connection of the blocks.
[0064] Block 100 a in FIGS. 8A and 8B is similar to block 100 , having curvilinear back portions 124 a and 134 a that extend from legs 120 and 130 . Curvilinear shapes frequently are more desirable due to the ease of removal of the block from a mold.
[0065] FIGS. 9 and 10 illustrate another embodiment of the block. Block 200 is similar to blocks 100 and 100 a of FIGS. 3 to 8 , except that there are no chamfers on the front of the block. The absence of chamfered edges and corners is that the top and the bottom of the block are interchangeable, that is, if block 200 is flipped over, it is a mirror image of another block 200 . By contrast, the minor image of block 100 would have to be manufactured separately if it is desired to use the block in more than one orientation when constructing a retaining wall.
[0066] FIGS. 9 and 10 show block 200 having parallel top face 202 and bottom face 203 . The length of face 204 is defined by the distance between corners 206 and 207 . Extending from front portion 210 are two legs 220 and 230 . Cores 221 and 231 are located primarily in the legs, though they extend into front portion 210 . Legs 220 and 230 extend to rear portions 224 and 234 , respectively, having rear faces 225 and 235 , respectively. Front face 204 and rear faces 225 and 235 each extend from top face 202 to bottom face 203 . The distance between faces 202 and 203 defines the thickness of the block.
[0067] Legs 220 and 230 are separated by void 240 . Each leg 220 and 230 has two side walls 222 , 223 and 232 , 233 , respectively, generally converging from the front to the back of the block. Block side walls 211 and 213 extend from top face 202 to bottom face 203 . Pin holes 215 and 216 and pin receiving cavities 217 and 218 are located on the front portion of the block.
[0068] FIGS. 11 and 12 illustrate another embodiment of the block of this invention and FIG. 12 shows how the blocks form a mating pair. FIGS. 13A , 13 B and 14 show block 300 along with block 200 in a course of blocks and in a wall. Block 300 is similar to block 200 , but one of the legs forms right angles at the front and the back of the block. Since there are no chamfers on the front of the block, the block can be used in any orientation, i.e., the bottom and top surfaces are interchangeable.
[0069] Block 300 has parallel top face 302 and bottom face 303 . Face 304 extends between corners 306 and 307 . Extending from front portion 310 are two legs 320 and 330 . Cores 321 and 331 are located primarily in the legs, though they extend into front portion 310 . Legs 320 and 330 extend to rear portions 324 and 334 , respectively, having rear faces 325 and 335 , respectively. Front face 304 and rear faces 325 and 335 each extend from top face 302 to bottom face 303 . The distance between faces 302 and 303 defines the thickness of the block.
[0070] Legs 320 and 330 are separated by void 340 . Each leg 320 and 330 has two side walls 322 , 323 and 332 , 333 , respectively. Leg side wall 322 joins front portion 310 and back portion 324 at right angles. Therefore, side 311 is perpendicular to the front face 304 and back face 325 . Side 313 is substantially similar to side 213 in block 200 . Side walls 332 and 333 generally converging from the front to the back of the block. The side walls extend from top face 302 to bottom face 303 . Pin holes 315 and 316 and pin receiving cavities 317 and 318 are located on the front portion of the block.
[0071] FIGS. 13A and 13B show blocks 200 and 300 in a course of blocks for the construction of a wall. FIG. 13A shows course 980 , in which block 300 is used as the corner block in the orientation as shown in FIGS. 11 and 12 . Block 300 is flipped over in FIG. 13B , which shows course 981 . During construction of a wall, courses 980 and 981 would be adjacent so that the wall would have an offset or running bond pattern.
[0072] FIG. 14 shows wall 985 formed from these two types of blocks.
[0073] FIGS. 15A and 15B show another block embodiment, in which pin receiving cavities are absent and the front portion of the block is provided with a channel. FIGS. 15A and 15B illustrate the bottom and top perspective views of block 400 . In FIG. 15A , the block is shown in the orientation as it is manufactured, that is, with the bottom surface facing up, and FIG. 16 shows a side view of the block, with pin holes and core shown in phantom. FIG. 15B shows the block stacked together with other blocks.
[0074] Block 400 has parallel top face 402 and bottom face 403 . Front face 404 extends between chamfered corners 406 and 407 and has chamfered top edge 408 . Extending from front portion 410 are two legs 420 and 430 . Cores 421 and 431 are located primarily in the legs, though they extend into front portion 410 . Legs 420 and 430 extend to rear portions 424 and 434 , respectively, having rear faces 425 and 435 , respectively. Front face 404 and rear faces 425 and 435 each extend from top face 402 to bottom face 403 . The distance between faces 402 and 403 defines the thickness of the block.
[0075] Legs 420 and 430 are separated by void 440 . Each leg 420 and 430 has two side walls 422 , 423 and 432 , 433 , respectively, generally converging to the back surfaces. Side 411 comprises the side surface of side wall 422 and the side of front portion 410 . Similarly, side 413 comprises the side surface of side wall 433 and the side of front portion 410 and has a complex geometry. Side walls 432 and 433 generally converge from the front to the back of the block. The side walls extend from top face 402 to bottom face 403 .
[0076] FIG. 15B shows the top perspective view of block 400 , illustrating that there are two pin holes. Pin holes 415 a , 415 b , 416 a and 416 b are located on the front portion of the block. A set of pinholes (e.g., 415 a and 415 b ) are aligned in a plane generally perpendicular to the front face of block 400 ; this same plane passes through the core (e.g., core 421 ). It is to be noted, however, that the pin hole position may be varied as desired. Channel 444 spans the length of the block on the bottom surface near the front face. Channel 444 is configured to receive the head of a pin extending from a pin hole in a block underneath. FIG. 15B also illustrates that back portion 424 rests on back portion 434 of an underlying block. This coincidence of back portions adds to the stability of a wall.
[0077] FIG. 16 shows pin holes in phantom and illustrates that pin holes 416 a and 416 b extend from the top to the bottom of the block with substantially the same diameter, though it is to be noted that passageways through a block thickness typically taper from the bottom to the top in the block (as-manufactured), for ease of removal of mold elements. FIG. 16 also shows pin hole 416 a opens into channel 444 . This type of pin hole is used with shouldered pins, to that the head of the pin lies within the channel.
[0078] Another embodiment of the block of this invention is shown in FIG. 17 . The block is similar to the block embodiments described above and has correspondingly similar elements, and not every element is numbered for this block. Block 500 has one leg 520 extending from front portion 510 to back portion 524 . Leg 520 comprises two side walls 522 and 523 , which join together with the front and back portions to form core 521 . The core is optional but preferred because it results in a lower weight block.
[0079] Pin holes 515 and 516 and pin receiving cavities 517 and 518 are located near the front face of the block. FIG. 17 demonstrates that a pair of blocks can be formed in the mold such that mold space is maximized. Convenient dimensions for block 500 are those in which the front face is about 24 inches (60.1 cm) wide and 8 inches (20.3 cm) high. The depth of the front portion is about 4 inches (10.1 cm), and the depth of leg 520 is about 8 inches (20.3 cm).
[0080] Blocks 600 and 700 are shown as a mating pair in FIG. 18 and for clarity are shown moved apart from their position in a mold box. The formation of a mating pair results in one block having three legs ( 620 , 630 , 680 ) and the other having four legs ( 720 , 730 , 780 , 790 ). Each leg has a core ( 621 , 631 , 681 and 721 , 731 , 781 , and 791 respectively). Block 600 is provided with pin holes ( 615 a / 615 b , 616 a / 616 b ) and channel 644 that extends the length of the block on its bottom surface. Similarly, block 700 is provided with pin holes ( 715 a / 715 b , 716 a / 716 b ) and channel 744 that extends the length of the block on its bottom surface. The legs have a curvilinear shape. The legs of block 600 extend from the front portion in equally spaced intervals, essentially dividing the block into thirds.
[0081] FIG. 18 illustrates that blocks having this curvilinear shape can be formed in a matching pair, thus maximizing the mold space and minimizing the amount of material needed for each block.
[0082] Regardless of the block embodiment, various pin configurations can be used, and two are shown in FIGS. 19A and 19B . If it is desirable to use a straight pin, the pin hole should be tapered or truncated so that the pin will not slide to the bottom of the block. Thus, as shown in FIG. 19A , pin 840 is in pin hole 116 of block 100 . The pin hole is provided with a taper about half way through the thickness of the block.
[0083] FIG. 19B shows pin 850 having head 852 attached to straight portion 854 . Head 852 rests on the top surface of block 400 . Pin hole 416 b has substantially the same diameter throughout the thickness of the block.
[0084] FIG. 20A shows a cross sectional view of a wall wherein blocks are stacked on top of each other, interlocked by pins 850 , which are placed in forward pin hole 815 . Head 852 fits within a channel (e.g., channel 444 in block 400 ) on the bottom surface of a block above. This arrangement produces a substantially vertical wall. FIG. 20B illustrates a wall in which blocks are set back from each other by placing pin 850 in the rearward pin hole of an underlying block. A wall having positive set back is frequently desirable because of both appearance and structural stability.
[0085] FIGS. 21 , 22 A, and 22 B illustrate mold box 900 , having first and second opposing end rails 902 and first and second opposing side rails 904 . The first and second end rails are spaced apart a distance d 1 and the first and second side rails are spaced apart a distance d 2 . Distance d 2 is less than distance d 1 . A third distance, d 3 , is the height of the mold box and defines the thickness of the block. The mold box sits on a bottom plate (not shown). The bottom plate, end rails and side rails together form a cavity in which blocks are molded. In order to form the blocks of this invention, the mold box is prepared by installing divider plate 950 . The divider plate thus forms first and second mold sections in the mold cavity. This plate preferably is machined from steel into the desired shape and dimensions and is bolted at either end to each side rail. FIG. 22A shows the divider plate bolted into mold box 900 with bolts 955 . FIG. 22B shows the divider plate with the bolts, the mold box, and the blocks shown in phantom.
[0086] Forming elements (not shown) for the cores, pin holes, and pin receiving cavities are hung over the mold box, and a concrete mix is poured into the mold box. The box is vibrated to compact the concrete mix, which solidifies it. The blocks can then be pressed out of the mold box, and away from the divider plate and forming elements, by a stripping shoe or head that presses on the block as the bottom plate moves away. The stripping shoe is designed to pass over all the forming elements and the divider plate to facilitate removal of the block. The block, on the bottom plate, is then moved, typically by a conveyor belt, to an oven, where it is heat cured.
[0087] Typically, the blocks are shipped in the same orientation in which they are manufactured. This is desirable because each handling step increases the cost of the block. This results in another desirable feature of the present invention. Since the blocks are manufactured in an overlapping configuration they form a compact and efficient package which is easy to handle and requires less space for shipping.
[0088] The front surface of the block may be provided with a desired appearance or pattern by treating the surface as it is removed from the mold, just after it has been removed from the mold, or after curing. The surface appearance can be made to be smooth, corduroy, molded, fluted, ribbed, sand blasted, or fractured, as is known to one of skill in the art. Chamfers or other edge detail can be included in this molding process, as desired, or a block can be treated after curing to round the edges, by methods known to those of skill in the art. A fractured or split appearance is desirable because the surface then has the appearance of natural stone. Mechanical means can be used to treat the surface of a block after it has been cured and such is very effective in producing the appearance of natural stone. Such means are described in commonly assigned, co-pending application U.S. Application Publication No. 2003-0214069 (Ser. No. 10/150,484, filed May 17, 2002), hereby incorporated herein by reference.
[0089] Though the blocks illustrated in the Figures may have any desired dimension, block 100 , for example (as in FIGS. 3 to 8 ) typically has a thickness (i.e., the distance between surfaces 102 and 103 ) of about 8 inches (20.3 cm) and a length (i.e., the distance from corner 20 a to corner 21 a ) of about 24 inches (60.1 cm). The length is determined by distance d 1 of the mold box.
[0090] For those blocks described above having a length of about 24 inches (60.1 cm), a depth (i.e., from the front surface to a back surface) of about 12 inches (30.5 cm), and a thickness of about 8 inches (20.3 cm), the weight is about 95 pounds. This translates to about 60 pounds per square foot of front face surface area. This is a convenient weight to use when positioning the blocks in a retaining wall and compares favorably to the weight of Prior Art blocks in terms of handling. Thus the blocks offer an advantage over the Prior Art blocks in terms of their higher front surface area per unit weight.
[0091] The blocks of this invention are efficient to use in constructing walls because the relatively larger face size, compared to the face size of prior art blocks, results in about one third more area when building a wall.
[0092] Although particular embodiments have been disclosed herein in detail, this has been done for purposes of illustration only, and is not intended to be limiting with respect to the scope of the claims. In particular, it is contemplated that various substitutions, alterations and modifications may be made to the invention without departing from the spirit and scope of the invention as defined by the claims. For instance, the choice of materials or variations in the shape or angles at which some of the surfaces intersect are believed to be a matter of routine for a person of ordinary skill in the art with knowledge of the embodiments disclosed herein. | A method of making a wall block and a mold box therefore. The wall block design maximizes the use of the mold box. The method produces wall blocks having a large surface area front face compared to the front face size of prior art blocks. The blocks have about one third more front surface area. This results in faster construction of walls and a faster construction sequence. The method of making the blocks makes efficient use of mold space and material, resulting in higher production yields and/or higher total daily production square footage. | 4 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention pertains to the art of washing machines and, more particularly, to a pump cycling system for controlling a drainage operation in a washing machine.
2. Discussion of the Prior Art
During operation, a clothes washing machine proceeds through a series of wash and rinse cycles. At least a terminal portion of each rinse cycle includes a spin cycle portion wherein a clothes article containing tub or basket is spun at a relatively high speed in order to extract water from the clothes. During the spin cycle, a drain pump is typically run full time in order to remove water from the washer. For a substantial portion of the spin cycle, the rate at which water is removed from the clothes is much lower than the rate that the pump can function. This results in the pump working in a mixture of air and water. Such operating conditions can cause premature wear on the pump, as well as developing excessive noise.
To address these concerns, various systems have been proposed which function to limit the operating time of a washing machine drain pump. For instance, it has been proposed in the art to activate the drain pump for only a prescribed percentage of the spin cycle, during intermittent, predetermined periods throughout the cycle, for a timed duration which can vary with wash load, or simply based on a sensed water level within the machine. Although these systems aid in addressing the problems noted above, excessive pump operation times still exist in accordance with these prior art arrangements, particularly in connection with the timed pump operation based systems. Based on at least these reasons, there is a need in the art for a control system which will effectively and efficiently reduce the cycle time of a drain pump in a washing machine.
SUMMARY OF THE INVENTION
The present invention is directed to a system and method for effectively controlling the time a drain pump of a washing machine is activated during a drain operation conducted as part of a spin cycle. In accordance with the invention, at least one dynamic operating parameter of the washing machine is sensed and used to control the activation and deactivation of the drain pump in a cyclic manner.
In accordance with the most preferred form of the invention, activation of the drain pump is dependent upon extraction speed and time. More particularly, the spin speed of the washing machine tub is monitored and when this speed has dwelled at a specified speed for a predetermined amount of time, a controller is employed to automatically cycle the drain pump for a prescribed time period. In accordance with a second embodiment of the invention, the torque employed to drive the washing tub during a spin cycle is monitored to trigger a drain operation. That is, a sensed increase of torque to the washing tub is indicative of the presence of an excess of water. As the torque decreases, the pump is cycled off. These control arrangements can actually be employed individually or in combination in accordance with the invention. Furthermore, input from a water level sensor could be used in connection with an additional, redundant system, i.e., as a verification measure for use in combination with one or more of the dynamic based pump cycle time control systems of the invention.
Based on the above, it should be apparent that the system of the present invention relies upon one or more specific dynamic variables of the washing machine in order to accurately and effectively control the operation of the drain pump so as to minimize cycle times. In any event, additional objects, features and advantages of the present invention will become more readily apparent from the following detailed description of preferred embodiments when taken in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut-away, perspective view of a horizontal axis washing machine incorporating a pump cycling control system according to the invention;
FIG. 2 is an exploded view of various internal components of the washing machine of FIG. 1; and
FIG. 3 is a cross-sectional view of the internal components of FIG. 2 in an assembled state.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
With initial reference to FIG. 1, an automatic horizontal axis washing machine incorporating the pump cycling control system of the present invention is generally indicated at 2 . In a manner known in the art, washing machine 2 is adapted to be front loaded with articles of clothing to be laundered through a tumble-type washing operation. As shown, automatic washing machine 2 incorporates an outer cabinet shell 5 provided with a front door 8 adapted to extend across an access opening 10 . Front door 8 can be selectively pivoted to provide access to an inner tub or spinner 12 that constitutes a washing basket within which the articles of clothing are laundered.
As is known in the art, inner tub 12 is formed with a plurality of holes 15 and multiple, radially inwardly projecting fins or blades 19 are fixedly secured to inner tub 12 . Inner tub 12 is mounted for rotation within an outer tub 25 , which is supported through a suspension mechanism (not shown) within cabinet shell 5 . Inner tub 12 is mounted within cabinet shell 5 for rotation about a generally horizontal axis. Actually, the rotational axis is angled slightly downwardly and rearwardly as generally represented in FIG. 3. A motor 27 , preferably constituted by a variable speed, reversible electric motor, is mounted within cabinet shell 5 and adapted to drive inner tub 12 through belt 28 . More specifically, inner tub 12 is rotated during both wash and rinse cycles such that articles of clothing placed therein actually tumble through either water, water/detergent or another washing fluid supplied within inner tub 12 . Given that inner tub 12 is provided with at least the plurality of holes 15 , the water or water/detergent can flow between the inner and outer tubs 12 and 25 . A pump 30 (see FIGS. 1 and 3) is provided to control the level of washing fluid within machine 2 , particularly the draining of the fluid from outer tub 25 . As will be detailed more fully below, the present invention is particularly directed to the manner in which pump 30 is operated so as to reduce cycling times.
The general manner in which the automatic washing machine 2 of FIG. 1 operates is well known in the art and is not considered an aspect of the present invention. Therefore, a full description of its operation will not be described here. However, for the sake of completeness, automatic washing machine 2 is also shown to include an upper cover 42 that provides access to an area for adding detergent, softeners and the like. In addition, an upper control panel 45 , including an LCD display screen 50 , is provided for manually establishing a desired washing operation. In the preferred embodiment shown, display 50 includes a plurality of selectable control areas or zones which can be accessed by a user to both program and operate washing machine 2 . In the most preferred form of the invention, display 50 takes the form of an LCD display, such as a 128× 96 dot matrix, touch screen display, which enables a user to readily review displayed data, preferably in alpha or word text format, and select from that data to establish and begin a desired washing operation. Display 50 could have the selectable areas at any location on the display. The manner in which washing machine 2 can be programmed is disclosed in U.S. Patent Application Ser. No. 09/741,067 entitled “Interactive Control System for a Laundry Appliance”, filed on Dec. 21, 2000, now U.S. Pat. No. 6,502,265, and incorporated herein by reference.
As best seen in FIGS. 2 and 3, in order to allow inner tub 12 to freely rotate within outer tub 25 during a given washing operation, inner tub 12 is spaced concentrically within outer tub 25 . This spacing establishes an annular gap 56 between the inner and outer tubs 12 and 25 . As will be discussed fully below, an axial gap is also created at the open frontal portions of inner and outer tubs 12 and 25 . During operation of washing machine 2 , the washing fluid can flow through gap 56 from inner tub 12 into outer tub 25 . In addition, small objects can also flow into the outer tub 25 through the axial gap. Unfortunately, it has been found in the past that some objects flowing through the axial gap can end up clogging or otherwise disrupting the normal operation of the pumping system, thereby leading to the need for machine repairs. In order to remedy this situation, it has been heretofore proposed to incorporate a flexible sealing device, generally indicated at 60 in FIGS. 1 and 3, which functions to bridge this gap between inner and outer tubs 12 and 25 to prevent such objects from flowing into the outer tub 25 . Further provided as part of washing machine 2 , in a manner known in the art, is a sealing boot 62 which extends generally between outer tub 25 and a frontal panel portion (not separately labeled) of cabinet shell 5 .
Reference now will be made to FIGS. 2 and 3 in describing the preferred mounting of inner tub 12 within outer tub 25 and the arrangement of both sealing device 60 and sealing boot 62 as the tumble cycle feature of the present invention is related to the presence of one or more of these structural elements. Inner tub 12 has an annular side wall 61 and an open front rim 71 about which is secured a balance ring 75 . In the preferred embodiment, balance ring 75 is injection molded from plastic, such as polypropylene, with the balance ring 75 being preferably mechanically attached to rim 71 . Inner tub 12 also includes a rear wall 77 to which is fixedly secured a spinner support 79 . More specifically, spinner support 79 includes a plurality of radially extending arms 81 - 83 which are fixedly secured to rear wall 77 by means of screws 84 or the like. Spinner support 79 has associated therewith a driveshaft 85 . Placed upon driveshaft 85 is an annular lip seal 88 . Next, a first bearing unit 91 is press-fit onto driveshaft 85 . Thereafter a bearing spacer 93 is inserted upon driveshaft 85 .
The mounting of inner tub 12 within outer tub 25 includes initially placing the assembly of inner tub 12 , balance ring 75 , spinner support 79 , lip seal 88 , first bearing unit 91 and bearing spacer 93 within outer tub 25 with driveshaft 85 projecting through a central sleeve 96 formed at the rear of outer tub 25 . More specifically, a metal journal member 99 is arranged within central sleeve 96 , with central sleeve 96 being preferably molded about journal member 99 . Therefore, driveshaft 85 projects through journal member 99 and actually includes first, second and third diametric portions 102 - 104 . In a similar manner, journal member 99 includes various diametric portions which define first, second and third shoulders 107 - 109 . Journal member 99 also includes an outer recess 111 into which the plastic material used to form outer tub 25 flows to aid in integrally connecting journal member 99 with outer tub 25 .
As best shown in FIG. 3, the positioning of driveshaft 85 in journal member 99 causes each of annular lip seal 88 , first bearing 91 and bearing spacer 93 to be received within journal member 99 . More specifically, annular lip seal 88 will be arranged between first diametric portion 102 of driveshaft 85 and journal member 99 . First bearing unit 91 will be axially captured between the juncture of first and second diametric portions 102 and 103 , as well as first shoulder 107 . Bearing spacer 93 becomes axially positioned between first bearing unit 91 and second shoulder 108 of journal member 99 . Thereafter, a second bearing unit 114 is placed about driveshaft 85 and inserted into journal member 99 , preferably in a press-fit manner, with second bearing unit 114 being seated upon third shoulder 109 . At this point, a hub 117 of a spinner pulley 118 is fixedly secured to a terminal end of driveshaft 85 and axially retains second bearing unit 114 in position. Spinner pulley 118 includes an outer peripheral surface 120 which is adapted to be connected to belt 28 driven in a controlled fashion by the reversible motor 27 in order to rotate inner tub 12 during operation of washing machine 2 . In order to provide lubrication to lip seal 88 , central sleeve 96 is formed with a bore 123 that is aligned with a passageway 124 formed in journal member 99 .
Outer tub 25 has associated therewith a tub cover 128 . More specifically, once inner tub 12 is properly mounted within outer tub 25 , tub cover 128 is fixedly secured about the open frontal zone of outer tub 25 . Although the materials for the components discussed above may vary without departing from the spirit of the invention, outer tub 25 , balance ring 75 and tub cover 128 are preferably molded from plastic, while inner tub 12 is preferably formed of stainless steel. Again, these materials can vary without departing from the spirit of the invention. For example, inner tub 12 could also be molded of plastic.
Outer tub 25 is best shown in FIG. 2 to include a plurality of balance weight mounting gusset platforms 132 and 133 , a rear mounting boss 136 and a front mounting support 137 . It should be realized that commensurate structure is provided on an opposing side portion of outer tub 25 . In any event, balance weight mounting platforms 132 and 133 , mounting boss 136 , mounting support 137 and further mounting boss 140 are utilized in mounting outer tub 25 within cabinet shell 5 in a suspended fashion. Again, the specific manner in which outer tub 25 is mounted within cabinet shell 5 is not considered part of the present invention, so it will not be described further herein. Outer tub 25 is also provided with a fluid inlet port 141 through which washing fluid, i.e., either water, water/detergent or the like, can be delivered into outer tub 25 and, subsequently, into inner tub 12 in the manner discussed above.
Furthermore, outer tub 25 is formed with a drain port 144 which is adapted to be connected to pump 30 for draining the washing fluid from within inner and outer tubs 12 and 25 during certain cycles of a washing operation.
As best illustrated in FIG. 3, inner tub 12 is entirely spaced from outer tub 25 for free rotation therein. This spaced relationship also exists at the front ends of inner and outer tubs 12 and 25 such that an annular gap 146 is defined between an open frontal zone 147 of outer tub 25 and an open frontal portion 149 associated with balance ring 75 . It is through a lower section of gap 146 that washing fluid can also flow from within inner tub 12 to outer tub 25 .
Flexible sealing device 60 is mounted so as to bridge gap 146 between inner and outer tubs 12 and 25 and, specifically, between balance ring 75 and tub cover 128 . Gap 146 is required because of deflections between inner tub 12 and outer tub 25 during operation of washing machine 2 . Sealing device 60 bridges gap 146 to prevent small items from passing through, but sealing device 60 is flexible so as to accommodate changes in the size of gap 146 resulting from deflections during operation. Sealing device 60 includes a first seal portion 151 that is fixed or otherwise secured to a rear or inner surface 152 of tub cover 128 and a second, flexible seal portion 155 , such as brush bristles or a plastic film, which projects axially across gap 146 and is placed in close proximity and most preferably in sliding contact with a front or outer surface 156 of balance ring 75 . As is also known in the art, sealing boot 62 includes an inner annular end 162 which is fixed sealed to tub cover 128 , an outer annular end 164 which is fixed to the front cabinet panel (not separately labeled) of cabinet shell 5 and a central, flexible portion 166 . As perhaps best shown in FIG. 3, flexible portion 166 actually defines a lower trough 168 .
In general, various wash cycles can be selected through display 50 , including “Normal”, “Extra Rinse” and “Stain Removal” cycles. During a normal washing operation, automatic washing machine 2 will proceed through a main wash cycle and a predetermined number of rinse cycles. In the main wash cycle, a preset amount of water is added to any detergent or other washing solution supplied in the areas beneath cover 42 and inner tub or spinner 12 is driven to tumble articles of clothing through the resulting solution. Periodically, it is preferable to alter the rotational direction of inner tub 12 during this period to vary the tumbling pattern.
After the wash cycle tumbling time period has elapsed, a drain cycle is initiated with a continued tumbling action. In the preferred embodiment, this tumble drain period lasts approximately 90 seconds. Following the tumble drain, inner tub 12 is subjected to a spin mode wherein inner tub 12 spins for approximately two minutes. At this point, the water/detergent solution has been substantially removed from within inner tub 12 , although the articles of clothing will certainly still possess a certain percentage of the solution. Next, the articles of clothing are subjected to the predetermined number of rinse cycles wherein inner tub 12 is filled to a predetermined level with water and placed in a rinse cycle tumble pattern. In the most preferred form, three rinse cycles are provided. In general, each of the rinse cycles sequentially incorporate a rinsing tumble mode, followed by a tumble drain, a pause drain and then a rinse cycle spin mode. Thereafter, a final draining occurs and inner tub 12 is allowed to coast to a stop position and the washing operation is completed. Further details of this overall operational sequence is described in commonly assigned U.S. Pat. No. 6,241,782 entitled “Horizontal Axis Washing Machine Incorporating Flush Tumble Cycle” issued Jun. 5, 2001, which is hereby incorporated by reference.
Washing machine 2 includes a central processing unit (CPU) 177 used to regulate tub drive controls 182 for motor 27 , cycle controls 184 , and pump 30 . As indicated above, the present invention is directed to the manner in which pump 30 is controlled in order to reduce cycling times. Therefore, until this point, the basic structure of washing machine 2 as described above is known in the art and has been described both for the sake of completeness and to provide support for the pump control system of the present invention which will now be described in detail.
As shown in FIG. 1, central processing unit (CPU) 177 incorporating a pump control circuit 179 used to regulate the operation of pump 30 . As also shown, CPU 177 is adapted to receive signals from a water level sensor 185 , an inner tub speed sensor 187 and a drive torque sensor 190 for motor 27 . During a spin or extraction phase of a washing operation, inner tub 12 is adapted to be rotated at increasingly high speeds. In accordance with the invention, when a predetermined speed is reached, pump 30 is activated. For instance, in the most preferred form, horizontal axis washing machine 2 is adapted to reach a final extraction speed of 800 rpm which is monitored by sensor 187 . Of course, the extraction speeds during other portions of the washing operation can vary and, accordingly, so will the threshold level for activation of pump 30 . In any event, when a signal of 800 rpm is received by CPU 177 , a timer 192 is initiated. If sensor 187 continues to indicate 800 rpm for one minute, pump control circuit 179 is used to cycle pump 30 . Therefore, the drain operation is performed when inner tub 12 reaches a constant, predetermined rotational velocity for a set period of time. In the most preferred form of the invention, pump control circuit 179 functions to cycle pump with a 15 second ON and 30 second OFF basis. This cycling operation continue until sensor 187 indicates a drop in the speed. Since this represents the final extraction or spin phase of the overall washing operation, at this point, the entire washing machine 2 would be turned off. However, it should be recognized that a corresponding cycling of pump 30 is performed in connection with each spin cycle, although the threshold speed will vary.
At this point, it should be readily understood that various changes and/or modifications can be made to the invention without departing from the spirit thereof. For instance, it is contemplated that pump 30 could be activated in the manner set forth above, while being deactivated based on other criteria. For instance, the power sent to pump 30 could be monitored. Based upon changes in the amount of power needed to operate pump 30 , pump 30 would be de-activated. That is, when the water level diminishes, the flow in pump 30 will be a combination of air and water. The power require to pump this combination would be significantly lower than just water. Therefore, a reduction in the operation of pump 30 under this condition would be warranted.
In a similar fashion, pump 30 could be partially or fully controlled in other ways or through a redundancy system to assure that the activation time of pump 30 is minimized. One particular approach takes a look at signals from water level sensor 185 . In this case, the cycling of pump 30 is regulated based on the water level in outer tub 25 of washing machine 2 . Specifically, when the water level is sensed to be close to a bottom portion of inner tub 12 , pump 30 is energized for a set amount of time. Therefore, pump 30 could also be cycled, even if the threshold speed requirement was not met, if the water level gets too high. In any case, it is preferable in accordance with the present invention to actually initiate the cycling of pump 30 when the water or washing solution comes close to or reaches the bottom of inner tub 12 . This can be estimated to be at the time the upper spin speed is reached as fully described above, directly through water level sensor 185 or, in accordance with a still further modification, by monitoring the torque used to drive motor 27 through tub drive controls 182 . That is, when the level of water reaches the bottom of the inner tub 12 , the torque needed to spin inner tub 12 increases significantly. Sensing this sharp rise in torque signifies a need to initiate a drain operation and, in accordance with the invention, pump 30 is cycled instead of running full time. In any event, the reduced pump cycle time system in accordance with the invention is only intended to be limited by the scope of the following claims. | A drain pump of a washing machine is cyclically activated during a drain operation conducted as part of a spin cycle in a manner which reduces the run time of the pump. At least one dynamic operating parameter of the washing machine is sensed and used to control the operation of the drain pump. In accordance with a preferred embodiment of the invention, the rotational speed of the wash tub is sensed and, when a predetermined spin speed is maintained for a prescribed period of time, the drain operation is initiated. Water level, pump power and/or drive motor torque can also be utilized as pump cycling control parameters. | 3 |
FIELD OF INVENTION
The present invention relates to an antioxidant compound having anti atherosclerotic effect and preparation thereof. The present invention relates to the synthesis of TPP+ coupled esculetin (mitochondria-targeted esculetin [Mito-Esc]) followed by the biological evaluation of Mito-Esc for its ability to attenuate Angiotensin-II-induced atherosclerosis in apolipoproteinE knockout (ApoE −/− ) mice along with the endothelial cell age-delaying effects of Mito-Esc.
BACKGROUND AND PRIOR ART REFERENCES
Atherosclerosis is an excessive inflammatory/proliferative response of the vascular wall to various forms of injury. It has been suggested that, during inflammation, reactive oxygen (ROS) and reactive nitrogen species (RNS)-induced endothelial cell damage represent an important primary event in the process of atherosclerotic lesion formation. The resulting oxidative and nitrosative stress impairs the critical balance of the availability of endothelium-derived nitric oxide in turn promoting the proinflammatory signaling events, ultimately leading to the plaque formation. Atherosclerosis initiating events may be different under different conditions; however endothelial dysfunction is known to be one of the major initiating events. Macrophages also undergo apoptosis inside the endothelium, leading to their phagocytic clearance.
Increased mitochondrial oxidative damage is a major feature of most age-related human diseases including atherosclerosis and abnormal electron leakage from mitochondria in the respiratory chain in oxidant-stressed cells triggers the formation of ROS in mitochondria leading to altered behavior of the cell/cell death. Previously many studies have linked excess generation of ROS with vascular lesion formation and functional defects. More so, a role for mitochondria-derived ROS in atherogenesis is supported by links between common risk factors for coronary artery disease and increased levels of ROS. Mitochondrial ROS is increased in response to many atherosclerosis inducers including hyperglycemia, triglycerides and ox-LDL. Aortic samples from atherosclerotic patients had greater mitochondrial DNA (mtDNA) damage than nonatherosclerotic aortic samples from age-matched transplant donors (Mitochondrial integrity and function in atherogenesis. Circulation. 2002; 106:544-549). Even though endothelial cells have low mitochondria content, mitochondrial dynamics acts as a prime orchestrator of endothelial homeostasis under normal conditions, an impairment of mitochondrial dynamics because of excess ROS production would cause endothelial dysfunction resulting in diverse vascular diseases. Exposure of endothelial cells to free fatty acids, a common feature seen in patients with metabolic syndrome increases mitochondrial ROS (Palmitate induces C-reactive protein expression in human aortic endothelial cells. Relevance to fatty acid-induced endothelial dysfunction. Metabolism. (2011) 60: 640-648).
Therefore keeping in view of the involvement of mitochondrial ROS in causing endothelial dysfunction leading to the accentuation of vascular diseases, it would be ideal to counteract mitochondrial ROS by targeting ROS scavengers specifically to the site of action. The major drawback of antioxidant therapy in the treatment of mitochondrial diseases has been the inability to enhance antioxidant levels in mitochondria. Recently, there was a breakthrough in mitochondrial targeting of antioxidants (Drug delivery to mitochondria: the key to mitochondrial medicine. Adv Drug Deliv Rev. (2000) 41: 235-50). Antioxidants were covalently coupled to a triphenylphosphonium cation (TPP), and these compounds were preferentially taken up by mitochondria (Selective targeting of a redox-active ubiquinone to mitochondria within cells: antioxidant and antiapoptotic properties. J Biol Chem. (2001) 276: 4588-4596). The lipophilic cations easily permeate through the lipid bilayers and subsequently build up several hundred-fold within mitochondria because of a large mitochondrial membrane potential. The uptake of lipophilic cations into the mitochondria increases 10-fold for every 61.5 mV difference in the membrane potential, leading to a 100- to 500-fold accumulation in mitochondria. This strategy not only reduces the concentration of the molecule that is being employed to scavenge ROS, but also reduces the non specific effects of the molecule if it were to be used at high concentrations to elicit a similar effect. Coumarins constitute a group of phenolic compounds widely distributed in natural products (The Pharmacology, Metabolism, Analysis and Applications of Coumarin and Coumarin-Related Compounds. Drug Metab Rev (1990) 22: 503-529), and they have recently attracted much attention because of their wider pharmacological activities. Of these, esculetin (6,7-dihydroxycoumarin) has been shown to be a lipoxygenase inhibitor, and it inhibits the production of leukotrienes and hydroxyeicosatetraenoic acid through the lipoxygenase pathway. More recently, esculetin has been reported to inhibit oxidative damage induced by tert-butyl hydroperoxide in rat liver (Inhibitory effect of esculetin on oxidative damage induced by t-butyl hydroperoxide in rat liver. Arch Toxicol. (2000) 74:467-72). Esculetin protects against cytotoxicity induced by linoleic acid hydroperoxide in HUVEC cells and the radical scavenging ability of esculetin was confirmed by electron para magnetic resonance spectroscopy (Protection of coumarins against linoleic acid hydroperoxide-induced cytotoxicity. Chemico-Biological Interactions 142 (2003) 239-254). However, as coumarins may have poor bioavailability in vivo and do not significantly accumulate within mitochondria, their effectiveness remains limited and because of this, they may have to be employed in higher concentrations to scavenge mitochondrial ROS. In the present patent application, we have used lipophilic cation (TPP+) to target esculetin (Fig. X) to mitochondria and show that mitochondria-targeted esculetin (Mito-Esc) protects oxidant-induced endothelial cell death via nitric oxide and AMPK-dependent pathways at far below concentrations than reported earlier with native esculetin and further we report that Mito-Esc significantly inhibits aortic aneurysm (AA) and atheromatous plaque formation in Angiotensin-II-induced atherosclerotic process in Apolipoprotein E −/− mice model. The following are the prior art literature related to the present invention (WO1996031206; U.S. Pat. No. 6,331,532; WO2008145116; U.S. Pat. No. 4,977,276; U.S. Pat. No. 4,230,624; WO2011115819).
OBJECTIVES OF THE INVENTION
The main objectives of the invention are as follows
1) To synthesize triphenylphosphonium cation (TPP+) coupled esculetin (Mito-Esc) and compare the accumulation of Mito-Esc versus native esculetin in mitochondria. 2) To study the effect of Mitochondria-targeted esculetin (Mito-Esc) during oxidative stress-induced endothelial cell death. 3) To study the age-delaying effects of Mito-Esc in human aortic endothelial cells (HAEC). 4) To understand the mechanisms of Mito-Esc in regulating oxidative stress-induced endothelial cell death. 5) To investigate the effects of Mito-Esc administration during angiotensin-II (Ang-II)-induced atherosclerosis in Apolipoprotein E knockout (ApoE −/− ) mice model.
SUMMARY OF THE INVENTION
Accordingly the present invention provides an antioxidant compound having anti atherosclerotic effect and preparation thereof. The invention relates to the synthesis of TPP+ coupled esculetin compound (mitochondria-targeted esculetin (Mito-Esc)) of formula 1, following the scheme as shown in scheme 1
The biological evaluation of Mito-Esc for its ability to attenuate Angiotensin-II-induced atherosclerosis in ApoE −/− mice has been done. Mito-Esc selectively accumulated in the mitochondria compared to native (un-tagged) esculetin. Mito-Esc at very low concentrations (2.5 μM) protected human aortic endothelial cells (HAEC) from H 2 O 2 or Angiotensin-II induced oxidative stress and cell death. Mito-Esc by upregulating nitric oxide (NO) levels via increased phosphorylations of both AMPK and eNOS protected HAEC from oxidant-induced cell death. Furthermore, Mito-Esc reduced H 2 O 2 -induced endothelial cell aging. In vivo experimentations in ApoE−/− mice revealed that administration of Mito-Esc in drinking water for 45 days significantly attenuated Ang-II-induced atherosclerosis by reducing plaque and aortic aneurysm incidence. Mito-Esc also significantly inhibited Ang-II-induced proinflammatory cytokines production along with the reduction in the levels of serum cholesterol, LDL and triglycerides while increasing the HDL levels. Taken together, it is concluded that Mito-Esc greatly protects oxidant-induced endothelial cell death and atherosclerosis in ApoE −/− mice by modulating intracellular pathways regulating nitric oxide levels and inflammatory cascades, indicating that the formula 1 is an antioxidant compound.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 . Mitochondria-targeted esculetin (Mito-Esc) but not esculetin protects endothelial cells from H 2 O 2 and Ang-II-induced cell death in human aortic endothelial cells (HAEC). Cells were treated with Mito-Esc or Esc (2.5 μM) for 24 h. A, shows the cell viability by trypan blue assay and B, shows the caspase-3 and -8 activation.
FIG. 2 . Mitochondria-targeted esculetin (Mito-Esc) restores H 2 O 2 -induced mitochondrial membrane depolarization in HAEC. Cells were treated with Mito-Esc (2.5 μM) for 16 h. A, shows the H 2 O 2 generation with Ang-II treatment and the effect of Mito-Esc on Ang-II-induced H 2 O 2 production and B, represents the mitochondrial membrane potential measured as described in Experimental section.
FIG. 3 . Mito-Esc induced nitric oxide generation is mediated by increased eNOS phosphorylation in HAEC. A, cells were treated with H 2 O 2 (500 μM) in the presence or absence of Mito-Esc (2.5 μM) or esculetin (2.5 μM) for a period of 8 h and nitric oxide levels were measured by employing DAF-2A as described in the experimental section. B, cells were treated with various concentrations of Mito-Esc (1-5 μM) for 8 h and eNOS and phospho-eNOS protein levels were measured by Western blot analysis as mentioned in the Experimental Section. D, cells were treated with Ang-II (500 nM) in the presence or absence of Mito-Esc (2.5 μM) for 8 h and eNOS and phospho-eNOS protein levels were measured. E, same as A except that eNOS and phospho-eNOS protein levels were measured by Western blot analysis. F, cells were treated with either H 2 O 2 (500 μM) or Ang-II (500 nM) in the presence or absence of either Mito-Esc or L-NAME (2 mM) for 24 h and cell viability was measured by trypan blue exclusion assay as described in Experimental Section.
FIG. 4 . Effect of Mito-Esc on AMPK phosphorylation in endothelial cells. A, HAEC were treated with various concentrations of Mito-Esc (1-5 μM) for 8 h and AMPK and phospho-AMPK protein levels were measured by Western blot analysis. B, cells were treated with H 2 O 2 (500 uM) in the presence or absence of either Mito-Esc (2.5 μM) or esculetin (2.5 μM) for 8 h and AMPK and phospho-AMPK protein levels were measured by Western blot analysis. C, same as B except that cells were treated with Ang-II (500 nM) in the presence or absence of Mito-Esc or esculetin.
FIG. 5 . Mito-Esc increases mitochondrial biogenesis in HAEC through the upregulation of SIRT3, PGC-1α and TFAM in endothelial cells. A, cells were treated with H 2 O 2 in the presence or absence of Mito-Esc for 8 h and mitochondrial staining was performed employing Mitotracker dye as described in the experimental section. B, shows the quantification of data shown in A by Image analysis software. C, HAEC were treated with various concentrations of Mito-Esc (1-5 μM) for 8 h and SIRT3 protein levels (marker of mitochondrial biogenesis) were measured by Western blot analysis. D, cells were treated with Ang-II (500 nM) in the presence or absence of Mito-Esc (2.5 μM) for 8 h and RT-PCR was performed for TFAM and PGC-1α (markers of mitochondrial biogenesis) using gene specific primers. E, cells were treated with Ang-II (500 nM) in the presence or absence of Mito-Esc (2.5 μM) for 8 h and SIRT3 and PGC-1α protein levels were measured by Western blot analysis.
FIG. 6 . Mito-Esc delays endothelial cell aging and also inhibits oxidative stress-induced cell senescence. A, HAEC were grown in the presence or absence of Mito-Esc (2.5 uM) for 6 passages/generations (P10 to P16) and then stained with senescence-associated b-Gal staining solution as described in the Experimental Section. B, cells (P8 passage, representing young cells) were treated with H 2 O 2 (500 uM) in the presence or absence of Mito-Esc (2.5 μM) for 24 h and stained with senescence-associated b-Gal staining solution as described in the Experimental Section.
FIG. 7 . Mito-Esc administration inhibits Ang-II induced atherosclerosis in ApoE −/− mice aorta. A, thoracic and abdominal aortic diameters in control, Ang-II and Ang-II+ Mito-Esc treated groups. Animal experiment protocol is described in the Experimental Section. B, represents percent aortic aneurysm incidence and C, percent plaque incidence. D, histopathological images of aorta stained with Hemaoxylene & Eosin (showing the plaque formation) and Mason-trichome (showing the fibrosis, blue color). Parenthesis indicates number of animals exhibited Aortic Aneurysm or plaque incidence.
FIG. 8 . Mito-Esc administration restores Ang-II induced inhibition of eNOS and AMPK phosphorylations in ApoE −/− mice aorta. eNOS and AMPK protein phosphorylation levels were measured in whole aortic tissue homogenates by Western blot analysis.
FIG. 9 . Mito-Esc administration inhibits Ang-II induced proinflammatory cytokines production in ApoE −/− mice. A, B, C and D shows the levels of serum tumor necrosis factor (TNF-α), interferon gamma (IFN-γ), macrophage colony stimulating factor-1 (MCP-1) and interleukin-6 (IL-6) respectively at the end of the 45 days animal protocol as described in the Experimental Section. E, shows the levels of Mac-3 (inflammatory macrophage marker) in serum at 15 and 30 days during the treatment protocol.
DETAILED DESCRIPTION OF THE INVENTION
Procedure for the Synthesis of Compound C:
Compound B (0.505 mL, 3.77 mmol) was taken in dry THF (10 mL) under nitrogen atmosphere and the temperature was cooled to −75 to −80° C. A solution of LDA (2 M in THF, 3.77 mL, 7.54 mmol) was added slowly to the reaction mixture at −78° C. and the resulting mixture was stirred for 1 h. A solution of compound A (1 g, 3.77 mmol) in dry THF (10 mL) was cooled to −78° C. in another flask. A solution of t-butyl lithiate B was added to compound A slowly at −78° C. and the resulting mixture was stirred at the same temperature for 1 h. The reaction progress was monitored by TLC. After completion, the reaction mixture was quenched with water (10 mL) and extracted with ethyl acetate (3×20 mL), the combined organic extracts were washed with water (20 mL) and dried over anhydrous Na 2 SO 4 filtered and concentrated under vacuum to afford the crude product (1.2 g) as colorless oil. The crude product was directly used as such in next step without any purification.
Procedure for the Synthesis of Compound E:
A mixture of compound 3 (2.6 g, crude, 7.761 mmol) and compound D (1.95 g, 7.761 mmol) in 75% aqueous H 2 SO 4 (26 mL) was stirred at RT for 18-20 h. The reaction progress was monitored by TLC. After completion, the reaction mixture was diluted with water (50 mL) and extracted with ethyl acetate (2×25 mL). The combined organic extracts were washed with water and dried over Na 2 SO 4 , filtered and concentrated under vacuum to obtain crude compound. The crude product was purified by flash column chromatography (Silica gel: 100-200 mesh) eluting with 50% ethyl acetate in hexane to afford the desired compound 5 (300 mg, Yield: 22%) as pale yellow solid.
1 H NMR (400 MHz, DMSO-d6): δ 1.31-1.37 (m, 8H), 1.57-1.61 (m, 2H), 1.77-1.80 (m, 2H), 2.67-2.63 (t, 2H, J=7.6 Hz), 3.53-3.50 (t, 2H, J=6.6 Hz), 6.05 (s, 1H), 6.73 (s, 1H), 7.04 (s, 1H), 9.12 (br, 1H), 10.4 (br, 1H). LCMS Purity: 93.88%, 371.15 (M+H).
Procedure for the Synthesis of Esucletin Analogue F:
To a stirred solution of compound E (140 mg, 0.379 mmol) in dry DMF (5 mL) was added TPP (99 mg, 0.379 mmol) and the resulting mixture was heated to 150-170° C. for 5-8 h. The progress of the reaction was monitored by TLC. After completion of the reaction, DMF was distilled off completely under reduced pressure to obtain crude compound. The crude product was washed several times with ethyl acetate and diethyl ether to afford the esucletin analog F (Yield: 140 mg, 57.8%) as pale brown solid.
1 H NMR (400 MHz, CD 3 OD): δ 1.34-1.42 (m, 6H), 1.53-1.56 (m, 2H), 1.61-1.69 (m, 4H), 2.68-2.72 (t, 2H, J=7.6 Hz), 3.34-3.41 (m, 2H), 6.04 (s, 1H), 6.74 (s, 1H), 7.07 (s, 1H), 7.72-7.89 (m, 15H). LCMS Purity: 88.99%, 551 (M−Br).
Endothelial Cell Experiments.
Human aortic endothelial cells (HAECs) were obtained from ATCC (Manassas, Va.) and maintained (37° C., 5% CO 2 ) in basal medium supplemented with 10% FBS, VEGF (5 ng/mL), hEGF (5 ng/mL), hFGF (5 ng/mL), IGF-1 (15 ng/mL), ascorbic acid (50 μg/mL), hydrocortisone (1 μg/mL), amphotericin (15 ng/mL), gentamicin (30 ng/mL) and heparin (0.75 Units/mL). Cells used in this study were between passages 4 and 9. Esculetin, Mito-Esc, TPP and nitric oxide synthase inhibitor (L-NAME) were added 2 h before the addition of H 2 O 2 or Ang-II.
Animal Experiments.
Experiments were conducted in 2-month-old male apolipoprotein E knockout (ApoE −/− ) mice according to the guidelines formulated for care and use of animals in scientific research (ICMR, New Delhi, India) at a CPCSEA (Committee for the Purpose of Control and Supervision of Experiments on Animals) registered animal facility. The experimental protocols were approved by the Institutional Animal Ethical Committee at CSIR-TICT (IICT/CB/SK/20/12/2013/10). Animals were randomly divided into 3 groups each n=7:1) control 2) Ang-II treatment and 3) Mito-Esculetin+Ang-II treatment. Ang-II and Mito-Esculetin treatment groups received Ang-II (sigma) at a dose of 1.44 mg/kg/day for 6 weeks through sub-cutaneous route where as control group received normal saline. Mito-Esculetin treatment group received the compound at a dose of 0.5 mg/kg/day in normal drinking water. All animals were fed on normal chow throughout the study. After 6 weeks, all groups of animals were sacrificed as per standard protocols for euthanasia.
Trypan Blue Cell Viability Assay.
At the end of the treatments, cells were harvested and re-suspended in 0.4% trypan blue (Life Technologies) and percent cell viability was counted using cell countess chamber (Life Technologies).
Caspase Activity.
At the end of the treatments, HAEC were washed twice with cold DPBS and lysed in buffer containing 10-mM Tris-HCl, 10-mM NaH 2 PO 4 /Na 2 HPO 4 (pH, 7.5), 130-mM NaCl, 1% Triton, and 10-mM sodium pyrophosphate. Cell lysates were incubated with either with caspase-3 fluorogenic substrate (N-acetyl-Asp-Glu-Val-Asp-7-amido-4-methylcoumarin) or caspase-8 fluorogenic substrate (N-acetyl-Ileu-Glu-Thr-Asp-7 amido-4-methylcoumarin) at 37° C. for 1 h. The 7-amido-4-methyl-coumarin liberated was measured in a multi mode reader (PerkinElmer) with λex=380 nm and λem=460 nm.
Measurement of H 2 O 2 Levels.
Amplex red reagent was used to detect the released H 2 O 2 from cells. At the end of the treatments, HAECs were trypsinized and 20,000 cells were resuspended in 100 μl of Kreb's ringer phosphate buffer (pH, 7.35) and the assay was initiated by mixing with 100 μl of Krebs-Ringer buffer solution containing 50 μM amplex red reagent along with 0.1 U/mL horseradish peroxidase (HRP). Immediately, formation of resorufin fluorescence was measured in multi mode reader (PerkinElmer) with λex=540 and λem=585.
Detection of Mitochondrial Transmembrane Potential Changes.
Mitochondrial potential was assessed by using the fluorescent potentiometric JC-1 dye. In healthy cells. JC-1 forms J-aggregates that display a strong red fluorescence with excitation of 560 nm and emission wavelength at 595 nm, in apoptotic or unhealthy cells, IC-1 exists as monomers that display a strong green fluorescence with excitation and emission at 485 nm and 535 nm, respectively. At the end of the treatments, cells were washed with Dulbeccos phosphate buffer solution (DPBS) and incubated with JC-1 dye (5 mg/ml) for 20 min. Cells were again washed twice with DPBS and maintained in culture medium. Fluorescence was monitored by using Olympus fluorescence microscope with Rhodamine and Fluorescein isothiocyanate (FITC) filters.
Measurement of Intracellular Nitric Oxide Levels.
Intracellular nitric oxide levels were monitored by using the Diaminofluorescein-diacetate (DAF-2DA) fluorescence probe. After the treatments, cells were washed with DPBS and incubated in fresh culture medium without fetal bovine serum (FBS). DAF-2DA was added at a final concentration of 5 μl, and the cells were incubated for 30 minutes. The cells were washed twice with DPBS and maintained in culture medium. Fluorescence was monitored by using Olympus fluorescence microscope with FITC filter (λex=488 nm and λem=610 nm). Fluorescence intensity was calculated by Image-Pro plus7.0 software.
Mitotracker Staining.
Mitochondrial content in cells was assessed by selectively loading the mitochondria with the red fluorescent dye Mitotracker (Invitrogen, Carlsbad, Calif.).
Western Blot Analysis.
At the end of the treatments, HAECs were washed with ice-cold DPBS and resuspended in RIPA buffer (20 mM Tris-HCl, pH 7.4/2.5 mM EDTA/1% Triton X-100/1% sodium deoxycholate/1% SDS/100 mM NaCl/100 mM sodium fluoride) containing protease inhibitor cocktail and phosphatase inhibitor cocktail-2 and -3. The lysate was centrifuged for 15 min at 12000×g. Proteins were resolved on 8% SDS-PAGE and blotted onto nitrocellulose membrane and probed with rabbit anti-p-eNOS (ser-1177), rabbit anti-eNOS, rabbit anti-p-AMPK-1α (Thr-172) and rabbit anti-AMPK antibodies and then incubated with horseradish peroxidase-conjugated goat anti-rabbit IgG secondary antibody (1:5000). Protein bands were detected by using HRP substrate (Millipore-luminata). All the antibodies used for this study were from CST.
Isolation of Cytosolic and Mitochondria Fractions from HAECs and Apo E −/− Mice Aortic Tissue.
HAECs were grown in 90-mm dishes, treated with or without Mito-Esculetin (2.5 μM) for 24 h. After the treatment, cells were washed thrice with PBS. Similarly Mito-Esculetin+Ang-II treatment group, Ang-II alone treatment group and control Apo E −/− mice aortic tissue was taken. The isolation of mitochondrial and cytosolic extracts was carried out using a commercially available Proteo Extract Cytosol/Mitochondria Fractionation Kit (Cat. no. QIA88-Merck, USA) according to manufacturer's instructions.
Measurement of Mitochondrial Bioenergetics.
The oxygen consumption rate (OCR) and extracellular acidification rates in HAEC treated with Mito-Esculetin (2.5 uM) for 24 h was measured using Seahorse XF24-extracellular flux analyzer (Seahorse Biosciences, North Billerica Mass.) according to the manufacturer's protocol.
β-Galactosidase (β-Gal) Staining.
Low and high passage number (which reflects young and aged) endothelial cells (HAEC) cells were treated with various concentrations of H 2 O 2 (50-500 μM)) for 8 h. Cells were washed in PBS, fixed for 3-5 min (room temperature) in 2% formaldehyde/0.2% glutaraldehyde, washed, and incubated at 37° C. with fresh senescence associated β-Gal (SA-, β-Gal) stain solution: 1 mg of 5-bromo-4-chloro-3-indolyl β-D-galactoside (X-Gal) per ml (stock=20 mg of dimethylformamide per ml)/40 mM citric acid/sodium phosphate, pH 6.0; 5 mM potassium ferrocyanide/5 mM potassium ferricyanide/150 mM NaCl/2 mM MgCl 2 . Staining was visualized after 24 h using a phase contrast microscope.
Detection and Quantification of Mito-Esc by Mass Spectrometry.
Initially, mitochondrial and cytosolic fractions were separated using a commercially available kit as mentioned elsewhere. Mito-Esc was quantified in the mitochondrial and cytosolic fractions obtained from HAEC and aorta of ApoE −/− mice of different treatment groups as mentioned in Animal Experiments section (Table-1). Electrospray ionization (ESI)-MS. ESI-MS (positive mode) measurements were performed using a quadrupole time-of-flight mass spectrometer (QSTAR XL, Applied Biosystems/MDS Sciex, Foster City, Calif., USA). The data acquisition was under the control of Analyst QS software (Applied Biosystems). For the CID (collision-induced dissociation) experiments, the precursor ions were selected using the quadrupole analyzer and the product ions were analyzed using the TOF analyzer.
The detailed description of these inventions is explained with following examples but these should not construe to limit the invention.
Example 1
Mitochondria-Targeted Esculetin (Mito-Esc) but not Native Esculetin Abrogates Oxidant-Induced Cell Death in Human Aortic Endothelial Cells (HAEC)
We have studied the effects of mitochondria-targeted esculetin (Mito-Esc) (2.5 μM) as well as the native esculetin (2.5 μM) on Ang-II (500 nM) and H 2 O 2 (500 μM)-induced endothelial cell death. For this, cells were pretreated for 2 h with either Mito-Esc or esculetin before they were incubated with either H 2 O 2 or Ang-II. Mito-Esc but not esculetin significantly inhibited oxidant (H 2 O 2 and Ang-II)-induced endothelial cell death ( FIG. 1C ). However, TPP + alone did not have any appreciable cytotoxic/cytoprotective effect in HAEC ( FIG. 2C ). Thereby, indicating that the observed protective effect of Mito-Esc is not because of the TPP + side chain coupled to esculetin. Next, to confirm that H 2 O 2 and Ang-II caused an apoptotic mediated cell death in HAEC, we measured caspase-3 and -8 activities in cells treated with same conditions as shown in FIG. 1B . The results showed that Mito-Esc-pretreated cells were markedly resistant to H 2 O 2 and Ang-II-induced caspase activation, whereas treatment with native esculetin elicited marginal effect on caspase-3 and -8 activation in H 2 O 2 and Ang-II treated cells as compared to Mito-Esc ( FIG. 2D ). These results are consistent with the cell death measured by trypan blue dye exclusion method.
Example 2
Mito-Esc Decomposes Ang-II-Induced H 2 O 2 Generation and Preserves Oxidant Mediated Depolarization of Mitochondrial Membrane Potential
Ang-II is known to increase oxidative stress through increased production of H 2 O 2 (Doughan A K, Harrison D G, Dikalov S I. Circ Res (2008) 102:488-96). To see the effect of Mito-Esc in regulating Ang-II-induced H 2 O 2 production in endothelial cells, HAEC were treated with Ang-II (500 nM) in the presence or absence of Mito-Esc (2.5 μM) for a period of 16 h and H 2 O 2 production was measured by Amplex red assay. In cells treated with Ang-II, H 2 O 2 generation was significantly increased by around 2.7 fold compared to untreated conditions ( FIG. 2A ). Interestingly, Mito-Esc co-treatment completely reversed H 2 O 2 levels to control conditions ( FIG. 3A ). Thereby suggesting that Ang-II-induced cytotoxicity in HAEC involves oxidative stress and that co-incubation of HAEC with mito-Esc greatly attenuates Ang-II-mediated cell death by decomposing H 2 O 2 levels. Further, we assessed the effect of Mito-Esc on H 2 O 2 -induced mitochondrial membrane depolarization. HAEC were treated with H 2 O 2 (500 μM) in the presence or absence of Mito-Esc for a period of 16 h and mitochondrial membrane potential was measured using a mitochondrial membrane sensor kit. Mito-Sensor is a cationic dye that fluoresces differently in apoptotic and nonapoptotic cells. The Mito-Sensor dye forms aggregates in mitochondria of healthy cells and exhibits a red fluorescence. In apoptotic cells, membrane potentials are altered and the Mito-Sensor dye cannot accumulate in mitochondria and, thus, remain as monomers leading to a green fluorescence. In agreement with the results shown in FIG. 1 and FIG. 2A , Mito-Esc significantly rescued H 2 O 2 -mediated mitochondrial membrane depolarization ( FIG. 2B ). These results indicate that Mito-Esc by decomposing mitochondria-derived H 2 O 2 , protects endothelial cells during oxidant stress.
Example 3
Mito-Esc Potentiates Nitric Oxide Generation Via Increased eNOS Phosphorylation in HAEC: Effect of NOS Inhibitor on Mito-Esc-Mediated Inhibition of Oxidant Mediated Cell Death
To gain mechanistic insight on Mito-Esc-mediated protection of endothelial cells from oxidant-induced endothelial cell death, initially we hypothesized that Mito-Esc may augment intracellular nitric oxide generation. To study this, HAEC were treated with both Mito-Esc and esculetin in the presence or absence of H 2 O 2 for a period of 4 h and nitric oxide (NO) levels were monitored by DAF-2 derived green fluorescence. Previously, it has been shown that DAF-2 forms a fluorescent triazole-type product in the presence of an oxidant derived from nitric oxide and oxygen interaction (Proc. Natl. Acad. Sci. USA 99: 11127-11132; 2002; Am. J. Physiol. Regul. Integ. Comp. Physiol. 286:R344-R431; 2004). Intriguingly, Mito-Esc alone but not native esculetin greatly enhanced the DAF-2 fluorescence in HAEC ( FIGS. 4A and 4B ). Thereby indicating that incubation of endothelial cells with Mito-Esc causes an increase in NO production. Also, Mito-Esc significantly restored H 2 O 2 -mediated depletion of NO levels ( FIGS. 4A and 4B ). However, under these conditions, native esculetin did not show any noticeable effect on NO generation ( FIGS. 4A and 4B ). Next, we investigated the possible role of endothelial nitric oxide synthase (eNOS) in mediating the Mito-Esc induced NO generation in HAEC. For this, endothelial cells were treated with various concentrations of Mito-Esc (1-5 μM) for a period of 8 h. Mito-Esc dose-dependently increased the phosphorylation of eNOS at Ser-1177 ( FIG. 4C ). To further substantiate the results of DAF fluorescence, eNOS phosphorylation was measured in HAEC incubated with either with H 2 O 2 or Ang-II for 8 h in cells pretreated with Mito-Esc or native esculetin. It was observed that both H 2 O 2 and Ang-II caused a reduction in Phospho eNOS (Ser-1177) levels ( FIG. 4D ). Ang-II treatment imposed a drastic inhibition of phospho-eNOS levels when compared to H 2 O 2 treatment in endothelial cells ( FIG. 4D ). Under these conditions, however, Mito-Esc but not native esculetin treatment caused cells resistant to oxidant-mediated decrease in eNOS-phosphorylation ( FIG. 4D and FIG. 4E ). Furthermore, incubation of cells with L-NG-Nitro-L-arginine (L-NAME), a known NOS inhibitor; significantly abrogated Mito-Esc-mediated cyto-protective effects against oxidant-induced cell death ( FIG. 4G ). Taken together, these results suggest that Mito-Esc mediated increase in nitric oxide generation via increased phosphorylation of eNOS is in part responsible for maintaining endothelial cell viability during oxidative stress.
Example 4
Mito-Esc Mediated Increase in eNOS Phosphorylation and NO Generation is Caused by Increased Activation of AMPK
Previously, it was shown that AMPK co-immunoprecipitates with cardiac endothelial NO synthase (eNOS) and phosphorylates Ser-1177 in the presence of Ca 2+ -calmodulin (CaM) to activate eNOS both in vitro and during ischaemia in rat hearts (FEBS Lett. (1999) 443:285-289). To test whether Mito-Esc mediates increased phosphorylation of eNOS through AMPK activation, initially, HAEC were treated various concentrations of Mito-Esc (1-5 μM) for 8 h and AMPK1-α phosphorylation (Thr-172) levels were measured. Mito-Esc lead to a dose-dependent increase in phospho-AMPK1-α (Thr-172) levels with maximum effect at 2.5 μM of Mito-Esc ( FIG. 4A ). Next, we investigated the phospho-AMPK1-α levels in HAEC treated with H 2 O 2 in the presence or absence of either Mito-Esc or native esculetin. Incubation of cells with either H 2 O 2 alone or in the presence of native esculetin for 8 h significantly decreased AMPK1-α phosphorylation and whereas incubation of cells with either Mito-Esc alone or in the presence of H 2 O 2 greatly enhanced the phospho-AMPK1-α levels ( FIG. 4B ). Similar results were obtained with Ang-II treatment, where it was found that Ang-II treatment significantly down regulated phospho-AMPK1-α levels and that co-incubation with Mito-Esc made cells resistant to Ang-II-mediated inhibition of phospho-AMPK1-α ( FIG. 4C ).
Example 5
Mito-Esc Treatment Increases Mitochondrial Biogenesis by Increasing SIRT-3, PGC-1A and TFAM Expressions
To see if Mito-Esc treatment modulates oxidant-induced deregulation of mitochondrial biogenesis, we have treated HAEC with either H 2 O 2 (500 μM) or Ang-II (500 nM) in the presence or absence of Mito-Esc (2.5 μM) for 8 h and then initially measured mitochondrial content using Mitotracker dye. It was found that Mito-Esc treatment significantly restored the oxidant-induced depletion of mitochondrial content ( FIGS. 5A and B). In fact, mito-Esc treatment alone increased mitochondrial content when compared to control. Next we investigated the ability of Mito-Esc to modulate the mitochondrial biogenetic regulators namely, silent mating type information regulation 2 homolog (SIRT)-3, Peroxisome proliferator-activated receptor-gamma coactivator (PGC)-1α and mitochondrial transcription factor A (TFAM). It was found that Mito-Esc treatment (1-5 μM) significantly increased SIRT-3 levels in HAEC treated for 8 h ( FIG. 5C ). Similarly, Mito-Esc (2.5 μM) significantly increased both RNA and protein levels of PGC-1α, TFAM in cells treated for 8 h. Consistent with FIG. 5A , Mito-Esc treatment significantly reversed the Ang-II treatment induced inhibition of PGC-1A, TFAM and SIRT-3 levels ( FIGS. 5D and E).
Example 6
Mito-Esc Delays Endothelial Cell Aging and Also Inhibits Oxidative Stress-Induced Cell Senescence
To study if Mti-Esc influences vascular aging; we have studied its effect on human aortic endothelial cell (HAEC) aging. For this, we used HAEC of different passages (representing different age) from P6 (young age) to P16 (old age). Also we have grown HAEC with Mito-Esc (2.5 μM) for six generations (six passages) to understand its chronic effects in regulating endothelial cell aging phenomenon. Results indicated that a chronic treatment of Mito-Esc greatly attenuated endothelial cell aging as evidenced by a significant reduction in the senescence-associated β-gal staining ( FIG. 6 A). Thereby, suggesting that Mito-Esc treatment delays endothelial cell aging. Also, interestingly, Mito-Esc significantly inhibited H 2 O 2 -induced premature senescence in P6 (young age) HAEC ( FIG. 6B ).
Example 7
Mito-Esc Administration Attenuates the Incidence of Ang-II-Induced Aortic Aneurysm and Atheromatous Plaque Formation in ApoE −/− Mice
It is well documented that endothelial dysfunction is the most dominant risk factor for the development of vascular disorders including atherosclerosis. In relation to this, we have investigated the physiological significance of Mito-Esc in attenuating Ang-II-induced aortic aneurysm and atherogenesis in ApoE −/− mice model. Grossly, thoracic and abdominal aorta of Ang-II+ Mito-Esc treated group showed a significant reduction in Ang-II-induced a) plaque extension, b) multiple numbers of micro/pseudo aneurysm formation and the c) maximal aortic diameters ( FIGS. 7A , B and C) at the end of six weeks. These changes in Ang-II+Mito-Esc group were comparable to control group mice. We further analyzed the vascular remodelling employing histological stains in tissue sections of thoracic aortas. H&E staining of Ang-II+Mito-Esc treated group aorta showed a complete protection from Ang-II treatment alone induced severe atherosclerotic lesions with thick walls, intimal plaques. It was also noticed that the luminal diameter was significantly restored in Ang-II+Mito-Esc treated mice compared to Ang-II alone treated mice ( FIG. 7D ). Masson trichrome staining revealed thick fibrous mature connective tissue surrounding/in between atheroma in Ang-II treated mice aorta which was almost disappeared in Ang-II+Mito-Esc treated group ( FIG. 7E ). The collagen tissue in the atheroma, intimal, medial and external region appeared as blue color indicative of extensive proliferation of collagen tissue occurred in the atheromatous region of Ang-II treated mice. To further corroborate Mito-Esc's ability to protect from Ang-II-induced endothelial dysfunction during the progression of atheromatous plaque formation, we measured phospho-AMPK, AMPK, phospho-eNOS and eNOS protein levels in total aorta lysate. Intriguingly, Ang-II+Mito-Esc mice showed a significant increase in the phosphorylation statuses of both Enos and AMPK as compared to either Ang-II alone treatment or control groups ( FIGS. 8A and B). These results are in agreement with cell culture results wherein, Mito-Esc treatment greatly increased phosphorylation of both eNOS and AMPK in HAEC. This suggests that Mito-Esc by increasing eNOS-derived nitric oxide generation restores endothelial function in Ang-II treated ApoE −/− mice. Along these lines, Ang-II+Mito-Esc treated mice showed a significant inhibition of Ang-II-induced proinflammatory cytokines (TNF-α, IFN-γ, MCP-1) production ( FIG. 9A-D ). In tune with this, we have also measured Mac-3 levels by flow cytometry. Mac-3 is a general marker for macrophage abundance often seen under inflammatory conditions. Ang-II treatment greatly elevated Mac-3 levels by 30 days of treatment protocol, indicating an increased macrophage accumulation ( FIG. 7G ). However, Ang-II+Mito-Esc group showed an inhibition of Mac3 levels during this time ( FIG. 9E ). Finally, to extend the vasculo-protective effects of Mito-Esc, it was observed that Mito-Esc treatment significantly reduced Ang-II mediated increase in the levels of LDL, VLDL, triglycerides and total cholesterol (Table 2). Also importantly, Mito-Esc treatment resulted in a significant rise in serum HDL levels (Table 2). Taken together, all these results implicate that Mito-Esc treatment significantly eases the incidence of vascular complications including plaque formation and aortic aneurysm.
TABLE 1
Cellular uptake of Esculetin and Mito-Esculetin
Mitochondrial
Cytosolic fraction
fraction
(nmol/mg protein)
(nmol/mg protein)
Esculetin (HAEC)
6249 ± 235
ND
Mito-Esc (HAEC)
4488 ± 104
14523 ± 342
Mito-Esc (Apo E −/− Mice Aorta)
ND
2547 ± 286
ND indicates Not Detected
TABLE 2
Serum lipid profile of Apo E −/− mice treated with Ang-II alone
or Ang-II+ Mito-Esc for 45 days and serum lipid profile was measured
Triglycerides
LDL
HDL
VLDL
Total Cholesterol
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
(mg/dL)
Control
175.33 ± 6.1
165.61 ± 15.6
23.58 ± 1.5
35.6 ± 0.7
364.51 ± 14.2
Ang-II
234.50 ± 21.5
423.93 ± 29.6
02.21 ± 1.2
46.9 ± 2.2
656.19 ± 34.2
Mito-Esc + Ang-II
150.74 ± 3.8
218.40 ± 20.9
45.53 ± 0.4
30.15 ± 0.4
414.85 ± 8.2 | The present invention relates to an antioxidant compound having anti atherosclerotic effect and preparation thereof. The present invention more particularly relates to the synthesis of TPP+ coupled esculetin (mitochondria-targeted esculetin [Mito-Esc]) followed by the biological evaluation of Mito-Esc for its ability to attenuate Angiotensin-II-induced atherosclerosis in apolipoproteinE knockout (ApoE −/−) mice along with the endothelial cell age-delaying effects of Mito-Esc. | 2 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention is concerned with flow valves operated by the angular displacement of a controlling stem.
These valves may be applied, among other area& to the control of flows, especially to the control of one or more flow lines, such as water lines, through little deflections of the controlling stem, in hand washbasins where cold and warm water must be mixed, for example, as well as in the automatic control of mechanisms, etc.
2. Description of the Related Art
A number of valves is well known based--the same as the invention--on a substantially cylindrical body with a flow inlet and a flow outlet, containing a flow sealing element associated with a controlling stem, which--once angularity deflected--produces a flow passing port in the side opposing to the stem pin.
Some of these valves are those described in U.S. Pat. No. 3,698,685, Lang; U.S. Pat. No. 4,320,891, Cairns; U.S. Pat. No. 4,403,570, Freehafer; and U.S. Pat. No. 4,586,464, Agerrley et al. In all these valves, the controlling stem is surrounded by a sealing ring near its inner end and said sealing ring is axially compressed in a lateral portion, a port being thus generated in the totally opposed portion, through which the flow runs in a substantially axial direction to the controlling stem.
This kind of valves is limited to small pressures in the network due to the low sensitivity of the controlling stem. In fact, due to its structure, the network pressure exerts a great force in the stem face located inside the valve body, thus making it necessary a proportionally greater force in the stem in order to control the valve. This disadvantage is even bigger in the designs of the previous art, in which additional axial compression elements are available, such as elastomeric springs or stems.
Another disadvantage of these valves is their little versatility, in the sense that they do not allow the pass of a flow once the deflection action in the controlling stem ends.
Even another disadvantage of these valves is that they may not be used in application requiting inner discharge, that is, these valves are solely destined to discharge the flow through the same opening in which the controlling stem is located, thus pouring the flow coaxially to it.
SUMMARY OF THE INVENTION
The invention offers a valve that may be operated by the angular displacement of a controlling stem, with respect to the stem which overcomes the disadvantages of the valves of the previous technique.
Valves which are the subject matter of this invention in general consist in a valve body with a substantially cylindrical axial hole or inlet having a forward narrowing or opening in one of their ends. In the inner wall of the axial hole there is a tight riling-shaped butt, where a controlling stem is located axially oriented to the valve body. This controlling stem projects outside the valve body through the forward opening or narrowing of the axial hole. An elastic ring is available in radial contact with the forward part of the controlling stem located inside the valve body.
A group of modalities of the valve which is the subject matter of this invention is generated when completing the valve with preset addressing devices of the angular displacement of the controlling stem (or cross with respect to the controlling stem). These devices may consist in defining the geometry of the forward opening of the oblong or star shaped valve, for example.
An additional group of modalities of the valve which is the subject matter of this invention considers the including of locking devices for the controlling stem in order to keep the passing of flow once the deflection action of the controlling stem ends.
Another group of modalities of the valve which is the subject matter of this invention is obtained by obstructing the forward opening or narrowing of the valve body through a membrane shaped in the same body, which joins to the controlling stem, thus forming the assembly of valve body, membrane and controlling stem, a single mono-block part allowing the swiveling of said controlling stem. Additionally, the controlling stem is equipped with a hole communicating its outside portion with the inner side of the valve.
Even another group of modalities of the valve which is the subject matter of this invention consists in a multiple or compound valve having one flow inlet and a number of outlets. This kind of multiple valve is made up of an array of several valves of the modalities already mentioned, which are selectively operated through an axial or main stem controlling the control stems of the array valves, thus allowing the switching of the flow inlet to any outlet.
Valves which are the subject matter of this invention are more compact, since they are made up of a lower number of elements, these being simpler than those of the traditional valves.
A second kind of advantages of the valves which are the subject matter of this invention is their greater sensitivity, requiring lower driving forces for the stem, even though the flow line is subject to great pressures, as compared with the previous valves.
A third kind of valves which are the subject matter of this invention, relates to their versatility in the applications, being able to admit designs allowing an alternative flow outlet to several distribution ducts; continuous outlet; timed outlet; in addition to the option between external or inner discharge to the valve, that is, the flow outlet--as in the traditional valves--follows the direction of the controlling stem, or the latter acts alone to deviate the flow to the outlet duct which is not located in the periphery to said stem.
BRIEF DESCRIPTION OF DRAWINGS
The advantages already mentioned shall be clearly deduced from the detailed disclosure of the invention supported by drawings, where:
FIG. 1 shows an isometric perspective in a longitudinal section of the first modality of the invention, in which the valve is closed.
FIG. 2 shows an isometric perspective in a longitudinal section of the modality shown in FIG. 1, in which the valve is opened.
FIG. 3 depicts a raised plan in a longitudinal section corresponding to the first modality of this invention with the valve closed equal to the condition of FIG. 1.
FIG. 4 depicts a raised plan in a longitudinal section corresponding to the modalities of FIGS. 1 to 3, with the valve opened equal to the condition of FIG. 2.
FIG. 5 shows an isometric perspective in a longitudinal section of a second modality of the invention, in which the valve is closed.
FIG. 6 shows an isometric perspective in a longitudinal section of the modality of FIG. 5, in which the valve is opened.
FIG. 7 depicts a raised plan in a longitudinal section corresponding to the second modality of this invention with the valve closed equal to the condition of FIG. 5.
FIG. 8 depicts a raised plan in a longitudinal section corresponding to the modalities of FIGS. 5 to 7, with the valve opened equal to the condition of FIG. 6.
FIG. 9 shows a raised plan in a longitudinal section of a third modality of the invention, in which the valve is closed.
FIG. 10 shows a raised plan in a longitudinal section of the third modality of the invention, in which the valve is opened.
FIG. 11 shows a raised plan in a longitudinal section of a fourth modality of the invention in a closed condition.
FIG. 12 is a raised plan in a longitudinal section of the same modality of FIG. 11 in an opened condition.
FIG. 13 shows a raised plan in a longitudinal section of a fifth modality of the invention, where the compound valve may be seen closed to the right outlet and opened to the left outlet.
FIG. 14 is a raised plan in a longitudinal section of the same modality of FIG. 13 with the compound valve closed.
FIG. 15 shows a raised plan in a longitudinal section of a fifth modality of the invention, where the compound valve may be seen closed to the left outlet and opened to the right outlet.
FIG. 16 depicts an isometric perspective of that portion of the valve where the controlling stem is located to show the positioning devices of the latter.
FIG. 17 shows a schematic view of the left section of the portion of the valve as the one shown in FIG. 16, depicting a lockable position of the controlling stem in one direction, displaced in a first direction without lock and under the condition of flow passing while the controlling stem is operated by hand for example.
FIG. 18 is a schematic view of the same left section of the portion of the valve of FIG. 17 depicting a centered position of the controlling stem under a condition of flow stopping.
FIG. 19 is a schematic view of the same left section of the valve shown in FIGS. 17 and 18, depicting a locked position of the controlling stem in a second direction and under a condition of flow passing.
FIG. 20 is a schematic view of permanent the left section of the portion of the valve as shown in FIG. 16, depicting a self-centering position of the stem without lock, with a two-degree freedom, centered and under a condition of flow stopping.
FIG. 21 is a schematic view of the same left section of the portion of the valve of FIG. 20, depicting a decentered position of the stem and under a condition of flow passing while the controlling stem is operated by hand for example.
FIG. 22 is a schematic view of the left section of the portion of the valve as shown in FIG. 16, depicting a self-centering position of the stem without lock, with a one-degree freedom, centered and under a condition of flow stopping.
FIG. 23 is a schematic view of the same left section of the portion of the valve of FIG. 22, depicting a position of the stem under a condition of flow passing while the controlling stem is operated by hand for example.
DETAILED DESCRIPTION OF INVENTION
FIGS. 1 to 4 show a first modality of valve according to the invention. This valve is made up of a valve body 11 with a substantially cylindrical axial hole 21, with a narrowing 31 in the forward end.
There is a ring-shaped butt 41 concentric and tight to the axial hole 21, the rear end of which opposed to narrowing 31 of the valve body 11 having a throat 161.
Axially to the valve body 11, there is a controlling stem 61, so that the forward end projects through narrowing 31 of the valve body 11, the diameter of said controlling stem 61 being substantially lower than the diameter of said narrowing 31. The other end of the controlling stem 61 goes beyond the throat 161 of the ring-shaped butt, said end having pivotal means, such a flattening or terminal boss 71.
Between the inner forward part of the valve body 11 and the forward part of the ring-shaped butt 41, a ring-shaped chamber is defined acting as seat for an elastic ring 131, which is radially adjusted to the controlling stem 61.
FIGS. 1 to 3 depict the first modality of the valve in closed condition. The valve inlet is located in its rear part (fight end). Flow enters the valve body through the throat 161 of the ring-shaped butt 41, being hold back there due to the watertightness achieved by the elastic ring 131, which is in radial contact with the controlling stem 61.
As shown in FIGS. 2 and 4, when a cross force to the controlling stem 61 (arrow 91) is exerted, said stem swivels around throat 161 of the ring-shaped butt 41 and radially compresses a portion of the elastic ring 131, generating an outlet port 101 totally opposed to the compressed portion of said elastic ring 131 through which the flow runs.
Once the force destabilizing the controlling stem 61 (arrow 91) ceases, and due to the resilient nature of the elastic ring 131, its compressed portion exerts a radial force in the controlling stem 61, the axial position being reestablished until reaching a full contact with said elastic ring 131, the valve becoming closed and assuming the same condition depicted in FIGS. 1 and 3.
As already shown, this first modality of valve is of the kind with a flow outlet coaxially to the controlling stem, which opens while said controlling stem is angularly displaced by the action of some cross force. Once the destabilizing force has ceased, the valve automatically closes.
The second modality of the valve, according to the invention, is depicted in FIGS. 5 to 8. The valve is made up of a valve body 12 having an axial hole 22 and a cross outlet duct or hole 112. The axial hole 22 completely crosses the valve body 12, while the cross outlet duct 112 abuts upon to said axial hole 22, preferably under the form of a bypass.
The axial hole 22 is substantially cylindrical with a narrowing 32 in its forward end.
There is a ring-shaped butt 42 concentric and tight to the axial hole 22 with a cross opening 122 corresponding to the intersection zone between the cross outlet duct 112 and the axial hole 22 of the valve body 12.
Axially to the valve body 12, there is a controlling stem 62, so that the forward end projects tightly through narrowing 32 of the valve body 12.
The diameter of said portion of the controlling stem 62 inside the valve is a little greater than the diameter of the portion passing through narrowing 32, but lower than the inner diameter of the ring-shaped butt 42, a flow distribution chamber 142 being thus defined and released by the cross hole 122 of the ring-shaped butt 42. Alternatively, a controlling stem with a substantially uniform diameter in its whole length may be considered, but equipped with ribs in its inner zone with respect to the valve, so that its accidental axial displacement may be avoided.
Between the inner forward part of the valve body 12 and the forward part of the ring-shaped butt 42, a first ring-shaped chamber is generated acting as seat for a sealing ring 82 (or forward sealing ring), which is radially adjusted to the controlling stem 62. Between the rear part of the ring-shaped butt 42 and a part of the rear butt 152 equipped with an opening 162, elastic in this case a second ring-shaped chamber acting as seat for elastic ring 132 (or rear elastic ring) is generated, which is radially adjusted to the rear end of the controlling stem 62.
FIGS. 5 and 7 depict the second modality of the valve in closed condition with the flow held back in its rear end (right end). The controlling stem is aligned due to the action of a sealing ring 82 and an elastic ring 132, so that chamber 142 remains watertight with respect to the flow inlet. When an angular displacement in the outer end of the controlling stem 42 occurs, by applying a cross force in the sense of the arrow 92 (see FIGS. 6 and 8), for example, then said controlling stem 62 swivels around narrowing 32 of the forward end of the axial hole 22, and the rear end of said controlling stem 62 radially compresses a portion of the rear elastic ring 132, generating a port 102 in its totally opposed portion. The flow enters chamber 142 through this port 102, from which it is exhausted to the cross opening 122 of the ring-shaped butt 42, to be released by the cross outlet duct 112 of valve body 12.
Once the cross force applied to the outer end of the controlling stem 62 (arrow 92) has ceased, the compressed portion of the elastic ring 132 forces said controlling stem 62 to axially align, becoming in full contact with said elastic ring and the valve becoming closed as shown in FIGS. 5 and 7.
Unlike the first modality of the invention, this second modality has inner discharge, that is, the flow outlet is not through the periphery of the controlling stem, but the flow is deviated to an outlet duct, which may be connected to a flow network. This feature allows to use the valve in control applications for flow lines through the controlling stem, without the latter showing leaks outwards.
From its operation point of view, the third modality of the invention consists in a valve in which flow runs through the center of the controlling stem after driving the latter. This third modality is depicted in FIG. 9 (closed valve) and FIG. 10 (opened valve) and is made up of a valve body 13 with a preferably cylindrical axial hole 23, crossing it completely. This axial hole 23 has a narrowing 33 in its forward end.
There is a ring-shaped butt 43 concentric and tight inside the valve body 13.
Axially to the valve body 13, there is a controlling stem 63, so that the forward end projects tightly through narrowing 33 of said valve body 13. This controlling stem 63 has a substantially axial hole 113 (it may be also skew) beginning in its outer end (left end) and deviating cross-sectionally to said stem in an intermediate zone to present an opening 183 inside the valve body 13.
The diameter of the controlling stem 63 inside the valve is a little greater than the diameter of the portion passing through narrowing 33, but lower than the inner diameter of the ring-shaped butt 43, a flow distribution chamber 143 being thus defined and released by opening 183 of hole 113 of the controlling stem. Alternatively, a controlling stem with a substantially uniform diameter in its whole length may be considered, but equipped with ribs in its inner zone with respect to the valve, so that its accidental axial displacement may be avoided.
Between the inner forward part of valve body 13 and the forward part of the ring-shaped butt 43, a first ring-shaped chamber is generated acting as seat for a sealing ring 83 (or forward sealing ring), which is radially adjusted to the controlling stem 63. Between the rear part of the ring-shaped butt 43 and a part of the rear butt 153 equipped with an eccentric opening 163, a second ring-shaped chamber acting as seat for an elastic ring 133 (or rear elastic ring) is generated and radially adjusted to the rear end of the controlling stem 63.
The fourth modality depicted in FIG. 11 (closed valve) and FIG. 12 (open valve) functionally behaviors in a similar way to the third modality, but with a more compact constitution. Due to its structure, the valve of this morality is suitable to be manufactured in such polymers as polypropylene or a similar one.
The valve of this modality is made up of just two parts and one elastic ring.
A first part constituting the valve of the fourth modality is the valve body 14, which has a substantially cylindrical cavity 24, opened in one of the ends of said valve body. In its closed end, this valve body 14 includes a controlling stem 64 axially projecting both to the inside of cavity 24 and the outside of said valve body, this controlling stem 64 being joint to the valve body 14 through a perimetric membrane 194, which is conformed in the same body. The controlling stem 64 has a skew hole 114 preferably communicating the center of its outer portion with a zone of the mantle of its inner portion, that is, the portion located in cavity 24 before the zone in which an elastic ring 134 is located.
A second part is a rear butt 154 which blocks in part the rear part of valve body 14. This rear butt 154 has a flow inlet hole 164 and a projection or the ring-shaped butt 44 adjusted in cavity 24 of valve body 14, thus defining a forward ring-shaped chamber which acts as seat for the elastic ring 114, this being radially adjusted in the mantle of the inner portion of the controlling stem 64.
With the valve balanced, that is, closed as shown in FIG. 11, the flow enters through opening 164 of the rear butt 154, said flow being confined in chamber 144 (formed in cavity 24, between the elastic ring 134 and the rear butt 154), so that the flow may not flow out through the skew hole 114 of the controlling stem 64, since this region is watertight isolated from chamber 144.
When a skew force is applied to the outer portion of the controlling stem 64 (arrow 94), this is angularly deviated swiveling in the membrane zone 194, which is elastically strained, so that the inner end of the controlling stem 64 radially compresses a portion of the elastic ring 134, generating a port 104 in the totally opposed portion to that compressed, the flow passing through it having to be exhausted through the skew hole 114.
When the destabilizing force has ceased, the elastic nature of membrane 194 and of elastic ring 134, allows the re-establishment of the controlling stem alignment 64, and the elastic ring 134 recovers its full contact with the periphery of said stem 64.
The fifth modality of the valve, according to the invention is depicted in FIGS. 13 to 15 and consists in a perimetric distribution compound valve with a generally axial flow inlet, and several perimetric outlets, preferably radial, each one of them equipped with its corresponding valves. A controlling stem blocks all outlet valves when it is in an axial balanced position and controls the flow outlet to one of the valve outlets, as the controlling stem is angularly deviated in the direction in which one or more of the corresponding outlet valve are closed.
When this compound valve is designed with two outlets, then its structure is of the "T" type, unlike its structure when designed with several outlets, in which case the valve body is circular with outlets being perimetrically distributed.
According to FIGS. 13 to 15, this fifth modality is compounded by a preferably circular valve body 15 with several radial outlets 115 and with one preferably axial inlet 25. Each radial outlet 115 has a valve 5 as those explained in the first, third or fourth modality, or some variation of them.
Especially in FIGS. 13 to 15, two valves 5 have been depicted similar to those of the modalities already mentioned, made up of an axial stem 65 (axial with respect to the outlet 115, but radial with respect to the valve body 15), perimetrically surrounded in an intermediate point of it through an elastic ring 135, which is seated in a ring-shaped cavity, generated between the outlet 115 of the valve body 15 and an end ring-shaped butt 45 adjusted in said outlet 115. The end of each axial stem 65 receiving the controlling force is in this case that located inside the valve and each one of these ends is controlled by a driving disk 205 linked to an axial or main controlling stem 605, which is mounted on a sealing ting with radial contact 85 that prevents the leak of the flow through narrowing or opening 35 of the valve body 15 through which said main controlling stem 605 leaves.
When a skew force is applied to the main controlling stem 605 represented by arrow 95 (see FIG. 13 or FIG. 15), this swivels around opening 35 and the driving disk 205 deviates the corresponding axial stem 65 of the corresponding valve 5 related to one of the outlets 115, radially compressing a portion of the elastic ring 135 of said valve 5 in particular, generating a flow outlet port 105 in the totally opposed portion to said elastic ring 135. Under this condition, the rest of the driving disk 205 moves away from the remaining axial stems associated with the other valves 5, so that the corresponding outlets 115 keep closed due to the action of their elastic rings 135.
Once the deflecting force applied to the main controlling stem 605 has ceased, the elastic ring 135 associated with outlet 115 which was opened, recovers its shape aligning the corresponding axial stem 65, closing said outlet and aligning the driving disk 205, so that the compound valve becomes completely closed, as shown in FIG. 14.
In all modalities already described, it has been shown that while the controlling stem is deflected by a cross three, the valve is in an opened condition, and when said force ceases, the controlling stem automatically centers itself and the flow ;passage is blocked. In these versions, it has been also shown that the controlling stem may be destabilized in any direction.
In some applications, it is advisable that the controlling stem becomes locked in the position of opened valve and, by the express application of a cross closing force, the valve becomes closed. FIG. 16 depicts the locking devices of the controlling stem outside the valve body. These locking devices make it possible to lock said controlling stem in the condition of opened valve permanently until its unlocking. Should the controlling stem be deviated in the opposed direction to that of locking, being brought beyond its center position, them the valve becomes temporarily opened, while the destabilizing force acts on said stem.
It is also advisable for certain applications to have devices limiting the direction in which the stem may be destabilized.
The preferred locking devices in this invention are shown in FIG. 16 and are made up of two fins 226 parallel and totally opposed each other, tangent to narrowing 36 of the valve body 16, through which the controlling stem 66 projects. In the inner side of each fin 226, the corresponding axial ribs 236 may be found, arranged in a direction which is coaxial to the direction of the spindle of the controlling stem when the latter is in its position of maximum deviation, so that when the controllings stem 66 is displaced (upwards in this case), it is pressed against the axial ribs 236 separating fins 226, which are elastically strained to allow said controlling stem 66 to move beyond the axial ribs 236, once their deformation has been restored which shall hold back said controlling stem in an unbalanced position, allowing the permanent passing of flow (see left section of FIG. 19). The self-centering tendency of the controlling stem due to the action of the elastic rings (not shown in FIG. 16) is not enough to strain fins 226, which shall yield under the application of an external centering force to said controlling stem.
Notwithstanding the fact that the locking devices preferred in this invention have been mentioned, they may be different; the axial ribs 236 may be replaced for example with ribs or projections, which shall perform the same function with respect to the temporary fixing of the controlling stem 66.
FIGS. 17 to 19 show the left section of the example depicted in FIG. 16, representing, therefore, a valve of the invention having locking devices (fins 226 and ribs 236).
FIG. 17 shows the valve in a not locked, opened condition. This condition is achieved when a cross force is downwardly applied to the controlling stem 66, that is, in a direction opposed to that in which the axial ribs 236 may be found, so that when the action of the force ceases, the valve becomes closed due to the self-centering characteristics of the controlling stem, assuming the condition depicted in FIG. 18.
FIG. 20 (closed valve) and FIG. 21 (opened valve) show the left section of a portion of a valve which is similar to that shown by FIG. 16, but without locking fins or ribs, in which the controlling stem 67 may be driven in any direction as shown in the modalities corresponding to FIGS. 1 to 15. To this effect, the opening or narrowing 37 of the valve body 17 has a diameter which is slightly greater than the diameter of the controlling stem 67.
FIGS. 22 and 23 depict the left section of the portion of a valve similar to that shown in FIG. 16, but without locking fins or ribs (FIG. 22 shows a closed valve and FIG. 23 an opened valve). The portion of the valve body 18 has a forward end opening or narrowing 38, which, unlike the previous modalities, is oblong, so that the controlling stem 68 may be displaced from its centered position just to two opposed eccentric positions (one degree freedom), each one of them without locking devices, so that the valve is temporarily opened, while some three is applied to the controlling stem 68. Depending on the application, it is obvious that opening or narrowing 38 may have a different shape from the oblong one, star-shaped for example, as the controlling stem is required to be controlled only in certain directions.
Some obvious variations of the valves already illustrated shall be considered included in this report, as well as some applications of them.
A first group of obvious variations consists in modifying the action of the controlling spindle, so that it may act through a parallel displacement to its axis, unlike the way shown for the different preceding modalities, in which the action of said controlling spindle was achieved through its angular displacement.
A group of these obvious variations may result from the installation of different drivers arranged in the free end of the controlling stem, such as flags which increase the action area of a force (pressure) to or crossly displace said controlling stem. Then, in the case of flags, the passing flow may be driven by the pressure exerted on this flag through a blowing (applicable in the case of washbasins for instance) or through the pressure exerted by the jet of some liquid (applicable in the case of urinals for instance).
Another group of obvious variations may result :from certain applications as controlling valves of other valves handling greater flows, as the case when one of the valves of the invention is installed to actuate a membrane valve, starting the pressure differential required by them to allow the passing of the flow.
An additional group of obvious variations is preferably applied to the family of modalities as depicted in FIGS. 5-8, where opening 162 of the rear butt 152 may be concentric to the body of the valve 12 and with a diameter which is smaller than the diameter of the rear end of the controlling stem.
Even another group of obvious variations associated with certain applications may be the incorporation of an external spring destabilizing the controlling stem and perform the fastening to said controlling stem in its centered position (closed valve) by some resin or wax melting down at a preset temperature, thus a valve for fire control being obtained.
These valves may be also controlled by the cross force exerted on the controlling stem by a bimetal foil deflected with temperature changes.
These and other possible variations result from such special features of these valves, such as sensitivity and compact size.
Some of the countless applications may include the pressure regulation, dosing, irrigation, sprayers, fire control systems, reservoir level control, valve control (diaphragm, piston or others), etc. | A valve for controlling fluid flow comprises a body having an inlet and an outlet, the body having an opening at one end; a controlling stem disposed axially of the body with one end portion extending through the body opening, the stem being pivotable about the body opening between a normal position when the valve is closed and a pivoted position when the valve is open; and a first elastic ring disposed within the body in sealing contact with the stem and disposed between with the inlet and the outlet, thereby to prevent fluid flow from the inlet to the outlet. The stem when in the pivoted position being adapted to deform the first elastic ring to create an opening between the stem and the first elastic ring, thereby to permit fluid to flow from the inlet through the opening to the outlet. | 5 |
CROSS REFERENCE APPLICATION
This patent application claims the benefit of the earlier filed Israeli Patent Application Ser. No. 151486 Filed Aug. 26, 2002.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not Applicable.
BACKGROUND OF THE INVENTION
There is a significant number of patents which describe different constructions of cryosurgical probes and catheters. These patents aims to solve some of the problems, which are common to the cryosurgical probes and catheters of the prior art.
One of these problems is the construction of relatively cheap and simple probes or catheters with high reliability and sufficiently effective thermal insulation of their lateral non-operating walls. Moreover, cryosurgical catheters should have high flexibility, especially, when they are used for cardiac procedures. In addition, the closed distal end (cryotip) of such probe or catheter must provide in many cases high specific freezing capacity at sufficiently low-temperatures.
Analysis of United States patents related to this field shows, that the structure of the proposed probes and catheters intended for cryosurgery does not satisfy the above-mentioned requirements.
For example, U.S. Pat. No. 3,971,383 proposes a cryogenic surgical instrument with a coaxial assembly of flexible tubes, wherein the inner tube is connected to a supply of cryogenic liquid, and the space between the outer wall of the inner tube and the inner wall of an intermediate tube forms a return line for evaporated cryogenic liquid, which is vented to the atmosphere. The space between the outermost coaxial tube and the intermediate tube contains a gas, such as normal butane, for providing thermal insulation of the inner and intermediate lumens.
U.S. Pat. No. 5,716,353 describes a probe for cryosurgery which consists of three tubes: an inner tube for supplying a cryogenic refrigerant to a cryotip positioned at the distal end of an outer jacket tube, and an intermediate tube situated concentrically around the inner tube. The channel between the inner and intermediate tubes serves as venting path for venting cryogenic refrigerant from the freezing zone. This construction is simple, but it does not provide sufficient thermal insulation as required in the construction of cryogenic catheters. Consequently, it may cause over-heating of the vented cryogenic refrigerant, as well as over-cooling of tissues adjacent to the intermediate section of the catheter.
U.S. Pat. No. 5,573,532 describes a cryosurgical instrument which comprises tubes for cryogenic fluid supply and for the return of cryogenic fluid vapors, wherein these tubes are concentric and the return tube is sealed with a cryotip. Vacuum insulation of the return lumen is also proposed. However, this construction is relatively expensive and has low reliability. In addiiton, the proposed vacuum insulation limits the flexibility of the probe, especially, when it is very long, as in the case of catheter implementations.
U.S. Pat. No. 5,674,218 describes a cryosurgical instrument, a system and method of cryosurgery. According to this patent a cryogenic liquid (preferably, liquid nitrogen) is initially sub-cooled below its normal boiling point and in that state supplied into the open proximal end of the internal supply line. The outer lumen of the cryosurgical instrument is provided with active vacuum insulation.
Obviously, this construction cannot provide high flexibility and therefore cannot be used as the basis for construction of a catheter for use in cryosurgery.
U.S. Pat. No. 5,254,116 describes a cryocatheter with a set of vent holes in the lateral wall of a central feeding lumen, wherein sub-cooled liquid nitrogen is delivered into the central feeding lumen as a cryogenic liquid. This construction, however does not ensure proper thermal insulation of the cryocatheter.
BRIEF SUMMARY OF THE INVENTION
This invention proposes novel designs for a cryosurgical instrument and for its accessory system. The cryosurgical instrument of the present invention is constructed from two major sub-units:
i) a distal cryotip, which is used to contact the target tissue to be treated, wherein the freezing of the cryotip is obtained by evaporation of a cryogenic liquid on its internal surface, said internal surface being covered with a porous coating having open porosity; and
ii) an elongated tubular sub-unit for delivering portions of the cryogenic liquid to the distal cryotip and for removing vapors generated in the process of the boiling of the cryogenic liquid in the porous coating of the distal cryotip.
The elongated tubular sub-unit comprises an external shaft comprising a central feeding-venting tube, the lumen of which is used to supply portions of the cryogenic liquid to the porous coating of the distal cryotip and, at the same time, to remove the vapors generated in the process of boiling the cryogenic liquid on the internal surface of the distal cryotip into the atmosphere or into a vacuum pump.
In addition, a coaxial tubular piece is positioned in the space between the distal sections of the central feeding-venting lumen and the external shaft, the distal end of said tubular piece being sealed by the external shaft or by the cryotip itself, and its proximal end being sealed by the central feeding-venting tube. Said coaxial tubular piece forms a buffer space between the internal surface of the cryotip's shaft and the outer surface of the central feeding-venting tube, such that said buffer space facilitates flow of the portion the cryogenic liquid in the central feeding-venting tube toward the cryotip.
The proximal section of the external shaft and the proximal end of the central feeding-venting tube are provided with inlet-outlet connections.
According to another embodiment of the invention a coaxial intermediate lumen situated between the central feeding-venting lumen and the external shaft replaces the aforementioned coaxial tubular piece, wherein the distal end of this coaxial intermediate lumen is sealed by the external shaft or by the cryotip itself and its proximal end is sealed by the central feeding-venting tube. The proximal end of the external shaft is sealed by the wall of the proximal section of the coaxial intermediate lumen. The proximal section of the coaxial intermediate lumen is provided in this case with an outlet connection.
When this proposed device is used as a cryocatheter, the external shaft is made from a polymer material that provides high flexibility.
The cryotip of the cryocatheter is made from material with high thermal conductivity (for example, copper, silver, diamond, BeO), and its internal surface is advantageously covered with a porous coating having open porosity (for example, the porous coating that is obtained by sintering copper powder). These features permit high heat transfer coefficients values in the process of boiling the cryogenic liquid. Additionally, the porous coating is adapted to soak completely one portion of the cryogenic liquid provided by an accessory system during the first quarter-period (the first operating state in one operating cycle) of its operation, as will be described hereinafter.
The cryocatheter of the invention can be used for inhibiting restenosis of a blood vessel. In this case the cryotip is constructed in a tubular shape, the distal end of the tubular shaped cryotip is sealed with a plug made from a polymer with low thermal conductivity, and its tubular section is fabricated from a thin polymer film of high elasticity. The internal surface of the tubular section is coated with a porous polymer layer having open porosity and high elasticity.
The construction of preferable accessory systems for the cryocatheter (or cryoprobe) of the invention will be now described in detail.
A first embodiment of the accessory system, which achieves the functioning required for the proposed cryosurgical instrument, comprises: a thermo-insulated tank filled with the cryogenic liquid, wherein the thermo-insulated tank is provided with a relief valve which enables to preset the desired pressure in the thermo-insulated tank; a feed pipe which is situated vertically such that its lower end is positioned in the thermo-insulated tank and near its bottom. An outlet connection of the feed pipe is joined by a flexible thermo-insulated duct with an inlet connection of a multi-way valve. This multi-way valve comprises one additional inlet connection which communicates with a bottle containing pressurized gas (for example, nitrogen), and two outlets communicating with the atmosphere (or a vacuum pump) and with an inlet-outlet connection that communicates with an inlet-outlet connection of the central feeding-venting tube of the cryosurgical instrument.
The accessory system comprises four shut-off valves, the first of which is installed on a main duct that communicates between the multi-way valve and the inlet-outlet connection of the central feeding-venting tube of the cryosurgical instrument, the second—on a duct that communicates between the outlet connection of the thermo-insulated tank and the multi-way valve, the third—on the duct that communicates between the bottle comprising the pressurized gas and the multi-way valve, and the fourth—on the thermo-insulated tank; where this fourth shut-off valve is used for filling the thermo-insulted tank with the cryogenic liquid. The fourth shut-off valve is normally opened while filling the thermo-insulated tank with the cryogenic liquid. The second shut-off valve is used for cutting off the supply of the cryogenic liquid to the multi-way valve. The third shut-off valve is used for cutting off the supply of pressurized gas to the multi-way valve and the first shut-off valve for operating the cryosurgical instrument.
An electromechanical (or pneumatic) drive is used to perform a periodical changeover of the multi-way valve state at a preset changeover frequency for periodically communicating between the inlet-outlet connection of the central feeding-venting tube and the thermo-insulated tank, the bottle comprising the pressurized gas, and the atmosphere (or the vacuum pump).
A control unit used for controlling the changeover frequency of the multi-way valve, or for halting its operation in case of significant deviations from the preset frequency. The control unit also activates the aforementioned second and third shut-off valves. In addition, it is also possible to install pressure and temperature gauges on the main duct of the central feeding-venting tube of the accessory system. Data obtained from these gauges is processed by the control unit and in cases of significant deviations of the measured parameters from the preset values, the control unit cuts off the shut-off valves.
Portions of the cryogenic liquid, which remain in the porous coating of the cryotip and in the aforementioned buffer space in the period between communicating between the central feeding-venting tube and the inlet connection of the vacuum pump (or with the atmosphere) and with the feeding pipe of the thermo-insulated tank, generate reasonably high pressure in the central feeding-venting tube which may cause difficulties in introducing another portion of the cryogenic liquid into the central feeding-venting tube.
In the aforementioned embodiment, which utilizes a coaxial intermediate lumen with an outlet connection instead of the coaxial tubular piece, there is an auxiliary shut-off valve installed on a duct communicating between the outlet connection of the coaxial intermediate lumen and the atmosphere (or with the vacuum pump), wherein this shut-off valve is mechanically or electro-mechanically coupled to the multi-way valve such that it is opened only at a quarter-period, when the multi-way valve is communicating between the main duct and the bottle comprising the pressurized gas.
In addition, the outlet connection of the intermediate lumen can serve as an inlet-outlet connection. In this case, a gas contained in a special bottle is provided into the gap between the coaxial intermediate lumen and the central feeding-venting tube whenever the multi-way valve communicates between the central feeding-venting lumen and the atmosphere (or the vacuum pump).
The ducts connecting between the thermo-insulated tank and the multi-way valve, and between the multi-way valve and the inlet-outlet connection of the central feeding-venting tube can be provided with an outer thermal insulation, for example, vacuum insulation.
There are various cryogens that can be used as cryogenic liquids, such as liquid nitrogen, liquid argon, liquid R14 and others.
In addition, it is possible to utilize two tanks with different cryogenic liquids. For example, the first tank may comprise a cryogenic liquid having low boiling temperature (for example, liquid nitrogen), which is used for cryogenic treatment of a target tissue, and the second tank may comprise a cryogenic liquid having a relatively high boiling temperature (for example, R12B1 that boils at a temperature −3.8° C. at atmospheric pressure), where this second liquid is used for ice-mapping.
The second liquid having a normal boiling temperature higher than 0° C. (for example, R11, which has normal boiling temperature 23.65° C.) can be used for fast thawing a tissue, which has been previously frozen by the cryogenic liquid.
Application of two liquids with a large difference in their boiling temperatures requires performance of blowing out the central feeding-venting tube, the buffer space, and several ducts, in the period between the procedures of ice-mapping and cryogenic treatment which may follow it.
The accessory system comprises in this case two accessory sub-systems, each of which is constructed substantially similar to the accessory system which has been described hereinabove. The accessory sub-systems have a common control unit and a common main duct which splits off into two ducts each communicating with a first and a second multi-way valves. A thermo-insulated tank of the first accessory sub-system contains a cryogenic liquid that is used for freezing the target tissue, and the thermo-insulated tank of the second accessory subunit contains a liquid with relatively high boiling temperature (for example, R12B1) which is used for preliminary ice-mapping.
The accessory system also comprises an auxiliary accessory sub-system, which is used for blowing out the cryosurgical instrument and the ducts communicating the first and second accessory sub-systems with the cryosurgical instrument. The auxiliary accessory sub-system consists of an auxiliary bottle with pressurized gas and an auxiliary three-way valve, which is installed on a duct communicating the auxiliary bottle with the main duct. The auxiliary three-way valve is regulated by the common control unit, and it has two outlet connections; the first of which communicates with the main duct and the second with the atmosphere or with a vacuum pump.
The blowing out process is performed by closing the shut-off valves that are installed on the ducts communicating between the thermo-insulated tanks and their respective multi-way valves followed by blowing the pressurized gas from the auxiliary bottle into the main duct and the ducts splitting therefrom, and into the central feeding-venting tube and the buffer space by a charging and purging technique.
As was previously discussed hereinabove, the gap between the central feeding-venting tube (or the coaxial tubular piece) and the external shaft that is used for thermally insulating the external shaft, especially, its distal section, in order to prevent the possibility of a negative temperature on its outer surface.
It is of course possible to achieve a higher degree of thermal insulation of the external shaft of the cryosurgical instrument by first of all filling the gap between the external shaft and the coaxial tubular piece with a gas which has, on the one hand, very low thermal conductivity and, on the other hand, a condensation temperature that is lower than the boiling temperature of the cryogenic liquid. For this purpose, the proximal section of the external shaft is provided with an inlet-outlet connection and the accessory system is provided with an additional bottle comprising the aforementioned gas having low thermal conductivity, and with a duct that communicates between the additional bottle and the inlet-outlet connection of the external shaft, wherein said duct is provided with a three-way valve which communicates with the atmosphere or with a vacuum pump. This sub-system allows filling of the gap between the external shaft and the coaxial tubular piece by means of a charging and purging technique.
In order to achieve better thermal insulation properties of the distal section of the external shaft (i.e. to prevent its outer surface having a negative temperature) it is possible to apply the heat pipe principle.
In this case, the heat pipe principle is realized in the following manner: the outer surfaces of the coaxial tubular piece and a section of the central feeding-venting tube matching this coaxial tubular piece are covered with a porous coating with open porosity, the purpose of this coating being to function as a wick. The gap between the external shaft and the coaxial tubular piece, and its extension to the gap between the central feeding-venting tube and the external shaft is filled with a gas having a condensation temperature that is somewhat higher than the boiling temperature of the cryogenic liquid, wherein the solidification temperature of this gas is somewhat lower than the boiling temperature of the cryogenic liquid. This gas can be introduced into these gaps via the inlet-outlet connection installed on the proximal section of the external shaft.
A charging and purging technique can be used to realize the heat pipe principle described hereinabove. This technical solution allows heating the distal section of the external shaft at the expense of the heat provided to the intermediate and proximal sections of the external shaft from the surroundings.
It should be noted that the multi-way valve of the accessory system may be replaced by a set of shut-off valves installed on the communicating ducts, wherein the coordinated operation of this set of shut-off valves simulates the operation of the aforementioned multi-way valve.
The cryosurgical instrument of the present invention can be provided with a thermocouple positioned in the cryotip for measuring the temperature in the cryotip during of its use in a cryosurgical procedure.
In addition, if the cryosurgical instrument of the present invention is used in a cryocatheter implementation, this cryocatheter should be provided with a steering mechanism permitting bending of its distal section.
Furthermore, when the cryotip of the present invention is used in a cryocatheter (or cryoprobe) implementation, it may also be provided with an electrode for preliminary detection of electrical signal activity of different sites of the organ to be operated upon.
The cyclical operation of the cryosurgical instrument of the invention and its accessory system will be now described in detail.
In the first quarter time period, a portion of the cryogenic liquid is introduced via the feed pipe of the thermo-insulated tank into the duct (hereinafter also referred to as main duct) communicating between the multi-way valve and the inlet-outlet connection installed on the proximal end of the central feeding-venting tube. During this first quarter time period the state of the multi-way valve is in a position allowing flow of the cryogenic liquid from the feed pipe into the main duct
Thereafter, in the second quarter time period, the state of the multi-way valve is changed in order to cease the flow of the cryogenic liquid from the thermo-insulated tank into the main duct and during the next quarter time period the multi-way valve is set into a position in which it communicates between the bottle comprising the pressurized gas and the main duct, thereby accelerating the velocity of the portion of the cryogenic liquid passing through the main duct and the central feeding-venting tube such that it rapidly reaches the porous coating of the cryotip.
In the third quarter time period, the supply of the pressurized gas is shut off by setting the state of the multi-way valve into a state which cuts off the connection between the proximal end of the main duct and the feed pipe. During this time period the cryogenic liquid is boiling in the porous coating of the cryotip which in effect causes elevation of the pressure of the cryogenic liquid vapor in the central feeding-venting tube and in the main duct.
In the fourth quarter time period, the multi-way valve is placed into a state that communicates between the main duct and the outlet communicating with the atmosphere or with the vacuum pump. The boiling of the cryogenic liquid in the porous coating of the cryotip may continue during this time period. The aforementioned quarter time periods may of course have different durations.
The cryosurgical instrument of the invention may be designed as a cryocatheter intended to treat a blood vessel in order to prevent restenosis. In such cases it may be advantageous to have the cryotip constructed from an elastic polymer. It is therefore important to keep relatively low excessive pressure in the internal chamber of the distal section of this cryocatheter with small deviation from its average value. These conditions are advantageously obtained by the cryocatheter of the invention that is constructed with the coaxial intermediate lumen as was previously described hereinabove. The outlet connection of the coaxial intermediate lumen is provided with a T-shaped manifold, which comprises a crossbar and a main section intersecting perpendicularly with the crossbar. A pressure gauge is installed on one end of the crossbar and an adjusting valve is installed on its other end, wherein this adjusting valve is communicated with the atmosphere or with the vacuum pump. Signals from the pressure gauge are sent to a pressure control unit, which provides corresponding control signals for the operation of the adjusting valve. It should be noted that the pressure control unit may be interconnected with the aforementioned control unit, and by doing so the operations of these control units can be correlated.
It is an object of the present invention to provide a flexible catheter with high flexibility, high specific freezing power and a sufficiently small diameter for cryosurgical procedures in different areas of medicine.
It is another object of the present invention to provide a rigid probe with high specific freezing power and a sufficiently small diameter for cryosurgical procedures in different areas of medicine.
It is an additional object of the invention to provide a cryosurgical instrument and a suitable accessory system having a high degree of safety and reliability, which are suitable for carrying out cryosurgical procedures. It is a further object of the present invention to provide a cryosurgical instrument capable of ensuring positive temperatures at the distal section of its external shaft, especially, in the vicinity of the cryotip.
It is yet another object of the present invention to provide a method for thermal insulation of the distal section of the external shaft a cryosurgical instrument that is based on a heat pipe principle.
It is still another object of the present invention to provide a cryocatheter that may be used for inhibiting restenosis of a blood vessel.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
Other objectives of this invention will be apparent from the following detail description taken in conjunction with the accompanying drawings, in which:
FIG. 1 shows a general view of a cryosurgical instrument and a block diagram of a respective accessory system according to one preferred embodiment of the invention.
FIG. 2 shows a general view of a cryosurgical instrument and a block diagram of a respective accessory system according to another preferred embodiment of the invention.
FIG. 3 shows a general view of a cryosurgical instrument and a block diagram of a respective accessory system according to a further preferred embodiment of the invention in which different liquids are used for preliminary ice-mapping and for carrying out a cryogenic treatment.
FIG. 4 shows an axial cross-section view of the cryosurgical instrument of the invention that is implemented with an active thermal insulation based on the heat pipe principle.
FIG. 5 shows an axial cross-section view of a cryosurgical instrument of the invention comprising a coaxial tubular piece joined at its distal end with the external shaft of the instrument.
FIG. 6 shows an axial cross-section view of a cryosurgical instrument of the invention implemented with a coaxial intermediate lumen instead of the coaxial tubular piece.
FIG. 7 shows an axial cross-section view of a cryocatheter of the invention that is suitable for preventing restenosis of blood vessels.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a general view of one preferred embodiment of the invention wherein the cryosurgical instrument comprises: a cryosurgical instrument 100 comprising cryotip 116 and an elongated tubular sub-unit 105 ; and wherein the accessory system comprises: a thermo-insulated tank (or a Dewar flask) 101 for supplying a cryogenic liquid contained therein, said thermo-insulated tank 101 is provided with a relief valve 103 that allows presetting a desired pressure in the thermo-insulated tank, a shut-off valve 102 is used for filling the thermo-insulated tank 101 with the cryogenic liquid, and manometer 104 .
The multi-way valve 107 communicates between: a feeding pipe 106 situated in the thermo-insulated tank 101 ; a vacuum pump (or the atmosphere) via duct 121 ; the cryosurgical instrument 100 via a main duct 112 : a first bottle 108 comprising pressurized gas. Sensor 111 is used for controling the preset changeover frequency of the multi-way valve 107 . In addition, there are pressure and temperature gauges 114 and 120 installed on the main duct 112 . Data obtained from these sensor and gauges is processed by a control unit 115 . Whenever a significant deviations of the measured parameters (pressure and/or temperature) from the preset values, the control unit 115 cuts off the shut-off valves 109 , 110 and 113 .
The accessory system further comprises a second bottle 117 for providing a gas having a low thermal conductivity contained therein, for example R14. The second bottle 117 is communicated via duct 119 with the external chamber of the cryosurgical instrument 100 (the gaps shown in FIGS. 4 and 5 between the internal surface of the external shaft of the cryosurgical instrument 100 , and the outer surface of the coaxial tubular piece and of the proximal section of the central feeding-venting tube). A three-way valve 118 installed on duct 119 and used for filling the external chamber by a charging and purging technique that is typically performed before operating the cryosurgical instrument 100 and carrying out any cryogenic treatment.
FIG. 2 shows another preferred embodiment of the invention of a cryosurgical instrument 200 and its respective accessory system wherein there is an oscillating flow in the channel between the central feeding-venting lumen and the coaxial intermediate lumen of the cryosurgical instrument. Cryosurgical instrument 200 comprises two major sub-units: 1) cryotip 217 ; and 2) an elongated tubular sub-unit 218 .
In this preferred embodiment the accessory system comprises a thermo-insulated tank (or a Dewar flask) 201 for supplying a cryogenic liquid contained therein. The thermo-insulated tank 201 is provided with a relief valve 203 which is used to preset a desired pressure in the thermo-insulated tank 201 , with valve 202 which is used for filling the thermo-insulated tank 201 with the cryogenic liquid, and with manometer 204 .
A multi-way valve 208 comprised in the accessory system communicates between: a feeding pipe 205 situated in the thermo-insulated tank 201 ; a vacuum pump or the atmosphere; the cryosurgical instrument 200 (via main duct 215 ); a first bottle 210 which supplies a pressurized gas contained therein.; the accessory system further comprise a three-way valve 211 , which is coupled mechanically via coupling 212 to the multi-way valve 208 . The three-way valve 211 is used to communicate the coaxial intermediate lumen (exemplified in FIGS. 4 – 7 )—via duct 222 , or the central feeding-venting tube of the cryosurgical instrument 200 via the multi-way valve 208 , to the atmosphere (or vacuum pump) or to the first bottle 210 that is used for supplying a pressurized gas contained therein. A shut-off valve 213 , is installed on the duct which communicates between the first bottle 210 and the three-way valve 211 . Coupling 212 is designed to set the state of the three-way valve 211 into a state that communicates between duct 222 and the first bottle 210 whenever the multi-way valve 208 communicates between the main duct 215 and the atmosphere (or vacuum pump), and vice versa, namely—to set the state of the three-way valve 211 into a state that communicates between ducts 222 and the atmosphere (or vacuum pump) whenever the multi-way valve 208 communicates between the main duct 215 and the first bottle 210 .
Sensor 209 is provided in the multi-way valve 208 and used for controlling its preset changeover frequency. Data obtained from this sensor is processed by a control unit 223 . Whenever there are significant deviations of the measured parameters from the preset values, the control unit 223 closes the shut-off valve 207 that is installed on duct 206 and communicates between the feeding pipe 205 and the multi-way valve 208 , a shut-off valve 214 installed on a duct communicating between the first bottle 210 and the multi-way valve 208 , a shut-off valve 216 installed on the main duct 215 , and a shut-off valve 213 installed on a duct communicating between first bottle 210 and the three-way valve 211 .
The accessory system further comprise a second bottle 219 used for supplying a gas with low thermal conductivity contained therein, for example, R14. The second bottle 219 communicates via duct 220 with the external chamber (exemplified in FIGS. 4–7 ) of the cryosurgical instrument 200 (the gap between the external shaft of the cryosurgical instrument 200 and its coaxial intermediate lumen). A three-way valve 221 installed on duct 220 is used for filling the external chamber of the cryosurgical instrument 200 with a gas having low thermal conductivity by a charging and purging technique, which is typically performed before operating the cryosurgical instrument 200 and carrying out any cryogenic treatment.
FIG. 3 shows a further preferred embodiment of the invention which comprises a cryosurgical instrument and a respective accessory system that is adapted to supply two different liquids which are used for carrying out preliminary ice-mapping and a cryogenic treatment.
FIG. 3 shows a cryosurgical instrument 300 with its cryotip 332 and an elongated tubular sub-unit 333 , and a respective accessory system which comprises a first tank 301 used for supplying a first liquid contained therein which has cryogenic boiling temperature (for example, liquid nitrogen). The first tank 301 is provided with a relief valve 302 used for presetting the desired pressure in said first tank 301 , valve 304 which is used for filling the first tank 301 with said first liquid, and with manometer 303 .
The accessory system also comprise a multi-way valve 310 which communicates via duct 306 between: a feeding pipe 305 situated in the first tank 301 ; a vacuum pump or the atmosphere; the cryosurgical instrument 300 via a main duct 322 , wherein the main duct splits into two ducts 313 and 337 ; and a first bottle 308 used for supplying a first pressurized gas contained therein. A shut-off valve 307 is installed on duct 306 , a shut-off valve 338 is installed on duct 313 , and a shut-off valve 309 is installed on a duct that communicates between the first bottle 308 and the multi-way valve 310 . Sensor 312 is placed in the multi-way valve 310 for controlling its preset changeover frequency. Data obtained from this sensor is processed by a control unit 331 , and whenever there are significant deviations of the measured parameter from a preset value, the control unit 331 closes the shut-off valves 307 , 338 and 329 .
The accessory system also comprises a second tank 314 used for supplying a second liquid contained therein and which has relatively high boiling temperature. The second tank 314 is provided with: a relief valve 315 that is used for presetting the desired pressure in the second tank 314 ; valve 317 used for filling the second tank 314 with the second liquid; and manometer 316 .
A multi-way valve 321 is used for communicating between: a feeding pipe 318 that is situated in the second tank 314 (via duct 319 ) the atmosphere; the cryosurgical instrument 300 via the main duct 322 and duct 337 ; and a second bottle 323 with a second pressurized gas. A shut-off valve 320 is installed on duct 321 , shut-off valve 325 is installed on duct 324 for communicating between the second bottle 323 and the multi-way valve 321 , and a shut-off valve 326 is installed on duct 337 . Sensor 330 is provided in the multi-way valve 321 and used for controlling its preset changeover frequency. Data obtained from sensor 330 is processed by the control unit 331 , and whenever there are significant deviations of the measured parameter from a preset value, the control unit 331 closes the shut-off valves 320 , 325 and 326 .
A third bottle 328 is provided for supplying a third pressurized gas contained therein and which is communicated to the cryosurgical instrument 300 via ducts 327 , 337 and 322 . A three-way valve 329 is installed on duct 327 for communicating it with the atmosphere, according to control signal received from the control unit 331 which controls its state of operation. The three-way valve 329 is used for blowing out the ducts and the cryosurgical instrument 300 after carrying out an ice-mapping process in order to remove the second liquid and its vapors. Charging and purging technique is used to carry out the blowing out process.
A fourth bottle 334 is provided for supplying a gas with low thermal conductivity contained therein, for example, R14. The fourth bottle 334 is communicated via duct 335 with the external chamber (illustrated in FIGS. 4–7 ) of the cryosurgical instrument 300 (the gap between the external shaft of the cryosurgical instrument 300 , and its coaxial tubular piece and the proximal section of the central feeding-venting tube). A three-way valve 336 installed on duct 335 is used for communicating it with the atmosphere and for filling the external chamber of the cryosurgical instrument 300 by charging and purging technique, which is typically performed previously to operating the cryosurgical instrument 300 and carrying out any cryogenic treatment.
FIG. 4 shows an axial cross-section of a cryosurgical instrument 400 comprising an active thermal insulation based on a heat pipe principle.
A cryosurgical instrument 400 is constructed from two major sub-units: a distal cryotip 402 adapted for immediate contact with a target tissue, wherein the freezing action performed by this cryotip is obtained by evaporation of cryogenic liquid on its internal porous coating 403 which is formed from a porous metal with open porosity; and an elongated tubular sub-unit used for delivering portions of the cryogenic liquid on the internal porous coating 403 and for the removal of vapors generated in the boiling process of the cryogenic liquid in the internal porous coating 403 .
The elongated tubular sub-unit comprises: an external shaft 404 ; a central feeding-venting tube 401 which is used for supplying portions of the cryogenic liquid to the internal porous coating 403 of the distal cryotip 402 and also for removal of vapors, which are generated in the process of boiling of the cryogenic liquid in the internal coating 403 , into the atmosphere.
The elongated tubular sub-unit further comprises a coaxial tubular piece 405 positioned in the gap between the distal sections of the central feeding-venting tube and the external shaft 404 ; the distal end of the coaxial tubular piece 405 is sealed by cryotip 402 , and its proximal end is sealed by the central feeding-venting tube 401 .
The outer surfaces of the coaxial tubular piece 405 and a section of the central feeding-venting tube 401 mating this coaxial tubular piece are covered with a porous coating 406 with open porosity that is functioning as a wick when the gap between the external shaft 404 , the coaxial tubular piece 405 and the mating section of the central feeding-venting tube 401 is filled with vapors of a gas that its condensation temperature is higher than the boiling temperature of the applied cryogenic liquid.
The proximal end of the feeding-venting central tube is provided with an inlet-outlet connection 407 , and the proximal section of the external shaft 404 is provided with an inlet-outlet connection 408 .
FIG. 5 is an axial cross-section of a cryosurgical instrument 500 comprising a coaxial tubular piece 505 that is joined at its distal end with the external shaft 504 of the cryosurgical instrument 500 .
Cryocatheter 500 (or cryoprobe) is constructed from two major sub units: a distal cryotip 502 , which is used for contacting a target tissue, wherein the freezing action of cryotip 502 is obtained by evaporation of a cryogenic liquid in its internal porous coating 503 , which is formed from porous metal with open porosity; an elongated tubular sub-unit used for delivering portions of the cryogenic liquid to the internal porous coating 503 and for removal of vapors generated in the process of the boiling the cryogenic liquid in the internal porous coating 503 .
The elongated tubular sub-unit comprises an external shaft 504 and a central feeding-venting tube 501 , which is used for supplying portions of the cryogenic liquid to the internal porous coating 503 of the distal cryotip 502 and for removal of vapors, generated in the process of boiling of the cryogenic liquid on the internal porous coating 503 , into the atmosphere.
The elongated tubular sub-unit further comprises a coaxial tubular piece 505 positioned in the gap between the distal sections of the central feeding-venting tube 501 and the external shaft 504 , wherein the distal end of the coaxial tubular piece 505 is sealed with the external shaft 504 and its proximal end is sealed by the central feeding-venting tube 501 . The proximal end of the feeding-venting central tube 501 is provided with an inlet-outlet connection 506 , and the proximal section of the external shaft 504 is provided with an inlet-outlet connection 507 .
FIG. 6 shows an axial cross-section of a cryosurgical instrument 600 comprising a coaxial intermediate lumen instead of the coaxial tubular piece that was used in the previously described cryosurgical instrument.
A cryosurgical instrument 600 is constructed from two major sub-units: a distal cryotip 602 , which is used for contacting a target tissue, wherein the freezing action of cryotip 602 is obtained by evaporation of a cryogenic liquid on its internal porous coating 603 formed from porous metal with open porosity; and an elongated tubular sub-unit used for delivering portions of the cryogenic liquid to the porous coating and for removal of vapors generated in the boiling process of the cryogenic liquid in the internal porous coating 603 .
The elongated tubular sub-unit comprises an external shaft 604 and a central feeding-venting tube 601 , which is used for supplying portions of cryogenic liquid to the internal porous coating 603 of the distal cryotip 602 and for removal of the vapors, generated in the boiling process of the cryogenic liquid in the internal coating 603 , into the atmosphere.
The elongated tubular sub-unit further comprises a coaxial intermediate lumen 605 positioned in the gap between the central feeding-venting tube 601 and the external shaft 604 ; the distal end of the coaxial intermediate lumen 605 is sealed by the external shaft 604 and its proximal end is sealed by the central feeding-venting tube 601 . In addition, the proximal end of the external shaft 604 is sealed by the proximal section of the coaxial intermediate lumen 605 . The proximal end of the feeding-venting central tube 601 is provided with an inlet-outlet connection 607 , the proximal section of the external shaft 604 is provided with an inlet-outlet connection 609 , and the proximal section of the coaxial intermediate lumen 605 is provided with an inlet-outlet connection 608 . The outer surface of the coaxial intermediate lumen 605 is covered with a porous coating 606 starting at its distal end and ending near its proximal end. The porous coating 606 is used as a wick when a heat pipe principle is used for heating the distal section of the external shaft.
FIG. 7 shows an axial cross-section of a cryocatheter 700 adapted for preventing restenosis of blood vessels.
Cryocatheter 700 is constructed from two major sub-units: a distal cryotip, which is used for contacting a target tissue, wherein the freezing action of the cryotip is obtained by evaporation of a cryogenic liquid in an internal porous coating 704 formed from porous elastic polymer with open porosity which is provided on the internal surface of an external tubular piece 703 made from an elastic polymer.
The distal end of the external tubular piece 703 is sealed by plug 702 manufactured from a polymer material having low thermal conductivity.
An elongated tubular sub-unit is used for delivering portions of the cryogenic liquid to the internal porous coating 704 and for removal of vapors generated in the boiling process of the cryogenic liquid in the internal porous coating 704 .
The elongated tubular sub-unit comprises an external shaft 706 , and a central feeding-venting tube 701 , which is used for supplying portions of the cryogenic liquid to the internal porous coating 704 and for removal of the vapors, generated in the boiling process of the cryogenic liquid in the internal porous coating 704 , into the atmosphere.
Orifice 705 provided at the distal end of the central feeding-venting tube 701 is used for reducing the pressure in the internal chamber of the cryotip formed by plug 702 and in the external tubular piece 703 with the internal porous coating 704 .
In addition, there is a coaxial intermediate lumen 707 positioned in the gap between the central feeding-venting tube 701 and the external shaft 706 , wherein the distal end of this intermediate lumen 707 is sealed by the external shaft 706 and its proximal end is sealed by the central feeding-venting tube 701 . The proximal end of the external shaft 706 is sealed by the proximal section of the coaxial intermediate lumen 707 . The proximal end of the feeding-venting central tube 701 is provided with an inlet-outlet connection 708 , the proximal section of the external shaft 706 is provided with an inlet-outlet connection 710 , and the proximal section of the coaxial intermediate lumen 707 is provided with an inlet-outlet connection 709 . | The invention is directed to a cryosurgical instrument and to an accessory system operating on the base of refrigerant evaporation, wherein the portions of the refrigerant are periodically provided to the distal cryotip of the cryosurgical instrument via a central lumen thereof. The internal surface of the distal cryotip is preferably covered by a porous coating capable of soaking at least one portion of the refrigerant. The vapors obtained as a result of the refrigerant boiling on the porous coating of the cryotip are preferably removed through the central lumen of the cryosurgical instrument into the atmosphere. These features may be combined to construct a cryosurgical instrument with relatively high freezing power and small outer diameter which may be designed as a flexible cryocatheter or alternatively as a rigid cryoprobe. | 0 |
TECHNICAL FIELD
The present invention generally relates to fuel injectors, and more particularly to a fuel injector having a passage which conducts high pressure fluid.
BACKGROUND ART
Fuel injectors are today used in many engines, for example in diesel engines used in trucks and off-highway equipment. The recent efforts to reduce engine emissions have focused on, among other things, a more complete combustion of the air-fuel mixture in the engine cylinders. This, in turn, is facilitated by pressurizing the fuel in the fuel injectors to a very high level, for example 207 MPa (30,000 p.s.i). Because of the high pressures, passages in the fuel injector must be carefully designed so that structural failures are avoided. Intersecting passages pose a particular problem owing to the possibility of hoop stresses in the passages being additive, thereby further increasing the possibility of fatigue cracking.
One type of fuel injector utilizes a valving mechanism comprising a high-pressure spill valve and a direct operated check (DOC) valve wherein the former is operated to circulate fuel through the injector for cooling, to control injection pressure and to reduce the back pressure exerted by the injector plunger on the camshaft following injection.
SUMMARY OF THE INVENTION
A fuel injector includes an insert which creates an intersecting passage that eliminates additive hoop stresses and which further forms a seat for a spill valve.
More particularly, in accordance with one aspect of the present invention, a fuel injector includes a member having a first passage terminating at a base surface of a recess. A body is disposed in the recess and has a facing surface opposite the base surface and spaced therefrom to form a second passage placing the high pressure passage in fluid communication with a third passage.
Preferably, the body includes a fourth passage in fluid communication with the first passage via the second passage.
Further, the third passage may comprise a valve bore in the body. Also preferably, a guide bore is located in the member aligned with the valve bore and is placed in fluid communication with the first passage by the second passage. Still further, the first passage may be disposed at a certain radial distance from a central axis of the valve bore and the facing surface may have a central axis substantially coincident with the central axis of the valve bore and also may have a radial extent greater than the certain radial distance.
In addition, the body preferably has a radius greater than the radius of the facing surface. Also preferably, the member comprises a barrel, the body comprises an insert having a valve seat and a spill valve engageable with the valve seat is disposed in the third passage.
Also the third passage and the insert may be circular in elevation and the third passage may be centrally located in the insert.
Still further, the facing surface preferably has a first radial extent and further including a fourth passage in the body disposed at a second radius less than the first radial extent.
In accordance with another aspect of the present invention, a fuel injector includes a barrel having an insert recess and a first passage having an end in fluid communication with the insert recess and an insert is disposed in the insert recess and having a second passage in fluid communication with the first passage, a valve bore in fluid communication with the second passage and a surface defining a valve seat. A valve member is disposed in the valve bore and has a sealing surface and is movable to a position wherein the sealing surface is in sealing engagement with the valve seat.
In accordance with another aspect of the present invention, a fuel injector includes a barrel having an insert recess defined by a base surface, a first passage having an end in fluid communication with the insert recess and a guide bore spaced from the first passage. An insert is disposed in the insert recess and forms a second passage with the base surface. The insert includes a valve bore in fluid communication with the first passage via the second passage and a surface defining a valve seat wherein the guide bore is concentric with and in fluid communication with the valve bore. A valve member is disposed in the valve bore and has a sealing surface and is movable between an open position at which the sealing surface is spaced from the valve seat and a closed position wherein the sealing surface is in sealing engagement with the valve seat.
Other features and advantages of the present invention will be apparent to those skilled in the art from the following detailed description taken in conjunction with the drawings and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevational view of a fuel injector incorporating the present invention together with a camshaft and rocker arm and further illustrating a block diagram of a transfer pump and a drive circuit for controlling the fuel injector;
FIG. 2 is a sectional view of the fuel injector of FIG. 1; and
FIG. 3 is an enlarged, fragmentary sectional view of modifications to the fuel injector of FIG. 2 to incorporate the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a portion of a fuel system 10 is shown adapted for a direct-injection diesel-cycle reciprocating internal combustion engine. However, it should be understood that the present invention is also applicable to other types of engines, such as rotary engines or modified-cycle engines, and that the engine may contain one or more engine combustion chambers or cylinders. The engine has at least one cylinder head wherein each cylinder head defines one or more separate injector bores, each of which receives an injector 20 according to the present invention.
The fuel system 10 further includes apparatus 22 for supplying fuel to each injector 20, apparatus 24 for causing each injector 20 to pressurize fuel and apparatus 26 for electronically controlling each injector 20.
The fuel supplying apparatus 22 preferably includes a fuel tank 28, a fuel supply passage 30 arranged in fluid communication between the fuel tank and the injector 20, a relatively low pressure fuel transfer pump 32, one or more fuel filters 34 and a fuel drain passage 36 arranged in fluid communication between the injector 20 and the fuel tank 28. If desired, fuel passages may be disposed in the head of the engine in fluid communication with the fuel injector 20 and one or both of the passages 30 and 36.
The apparatus 24 may be any mechanically actuated device or hydraulically actuated device. In the embodiment shown a tappet and plunger assembly 50 associated with the injector 20 is mechanically actuated indirectly or directly by a cam lobe 52 of an engine-driven cam shaft 54. In the embodiment shown, the cam lobe 52 drives a pivoting rocker arm assembly 64 which in turn reciprocates the tappet and plunger assembly 50. Alternatively, a push rod (not shown) may be positioned between the cam lobe 52 and the rocker arm assembly 64.
The electronic controlling apparatus 26 preferably includes an electronic control module (ECM) 66 which controls: (1) fuel injection timing; (2) total fuel injection quantity during an injection cycle; (3) fuel injection pressure; (4) the number of separate injection segments during each injection cycle; (5) the time interval(s) between the injection segments; and (6) the fuel quantity delivered during each injection segment of each injection cycle.
Preferably, each injector 20 is a unit injector which includes in a single housing apparatus for both pressurizing fuel to a high level (for example, 207 MPa (30,000 p.s.i.)) and injecting the pressurized fuel into an associated cylinder. Although shown as a unitized injector 20, the injector could alternatively be of a modular construction wherein the fuel injection apparatus is separate from the fuel pressurization apparatus.
Referring now to FIG. 2, each injector 20 includes a high pressure fuel passage 80 leading from a plunger bore 82 to a passage 84. A cross passage 86 places the fuel passage 80 in fluid communication with a spill valve bore 88 within which is disposed a spill valve poppet 90. During operation of the injector 20, high pressure fuel is delivered to the spill valve bore 88 through the cross passage 86. The fluid pressure exerts a force on the walls of the cross passage 86 and the spill valve bore 88 that tends to radially expand or stretch those walls producing a hoop stress therein. This effect is particularly pronounced at or near the intersection of the cross passage 86 with the spill valve bore 88, where tensile stresses are developed at magnitudes that can lead to structural fatigue and failure.
Industrial Applicability
FIG. 3 illustrates modifications to the fuel injector 20 to incorporate the present invention. A member in the form of a barrel 100 includes a first or high pressure fuel passage 102 leading from a plunger recess 104 and terminating at a base surface 106 of an insert recess 108 wherein the insert is circular in elevation (i.e., in plan view in the orientation shown in FIG. 3). A further high pressure fuel passage 109 may also lead from the plunger recess 104 to the insert recess 108. A body or insert 110 of complementary shape to the recess 108 and having an outer radius slightly greater than the radius of the recess 108 is press-fitted to form an interference fit with the walls defining the recess 108 or is otherwise secured therein. The insert 110 includes a facing surface 112 opposite the base surface 106 and spaced therefrom to form a passage 114 which is preferably slot-shaped or any other suitable shape in elevation and having a radial extent centered on a central axis 116. Also preferably, the first passage is disposed at a certain radial distance from the central axis 116 wherein the radial extent of the facing surface 112 is greater than the certain radial distance.
A passage comprising a valve bore 118 is formed in the insert 110 coincident with the central axis 116. The insert further includes a wall 120 defining a valve seat 124. A guide bore 122 coincident with and similarly sized to the valve bore 118 is formed in the barrel 100. The valve bore 118 and the guide bore 122 are circular in elevation and a valve member in the form of the spill valve poppet 90 is disposed in the valve bore 118 and extends into the guide bore 122. The spill valve poppet 90 is movable between an open position at which the poppet 90 is spaced from the valve seat 124 and a closed position at which the poppet 90 is in sealing contact with the valve seat 124.
A further passage 140 is formed in the insert 110 and is disposed at a radial distance less than the radial extent of the facing surface 112. This radial distance may be the same as or different than the radial distance of the passage 102 from the central axis 116. Still further, the passage 140 may be aligned with the passage 102 or the passage 109 or may be angularly offset with respect thereto if the facing surface is other than slot-shaped in elevation.
Preferably, the bore 118, the valve guide bore 122 and the valve seat surfaces 124 are produced by a grinding operation after the insert 110 is placed in the recess 108.
The barrel 100 is then assembled with other components of the fuel injector 20.
As should be evident from an inspection of FIG. 3, the passage 114 interconnects the high pressure fuel passages 102 and 140, and the bores 118 and 122, thereby obviating the need for a conventional drilled passage to accomplish this result. The passage 114 does not experience the stress levels encountered by conventional intersecting passages, and hence the incidence of structural failure is minimized.
Numerous modifications and alternative embodiments of the present invention will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is for the purpose teaching those skilled in the art the best mode of carrying out the invention. The details of the structure and/or function may be varied substantially without departing from the spirit of the invention, and the exclusive use of all modifications which come within the scope of the appended claims is reserved. | A fuel injector includes a barrel having an insert recess therein within which an insert is disposed. A facing surface of the insert is located opposite a base surface of the recess and forms a passage interconnecting a high pressure fuel passage and a valve bore. High pressure intersecting bores are thus avoided, leading to a reduction in structural failures. | 5 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit of U.S. provisional patent application 60/776,396, filed on Feb. 23, 2006, entitled “Methods and Apparatus for Improved Cavity Ring-down Spectroscopy”, and hereby incorporated by reference in its entirety.
FIELD OF THE INVENTION
This invention relates to optical alignment in connection with cavity-enhanced spectroscopy.
BACKGROUND
Optical spectroscopy entails passing optical radiation through a sample, often referred to an analyte, and inferring properties of the analyte from measurements performed on the optical radiation. For example, trace gas detection can be spectroscopically performed by performing measurements to detect the presence or absence of spectral absorption lines corresponding to the gas species of interest. Spectroscopy has been intensively developed over a period of many decades, and various ideas have been developed to improve performance.
One such idea can be referred to as cavity-enhanced spectroscopy, in which the analyte is disposed within an optical cavity (i.e., an optical resonator). The cavity can enhance the interaction between the analyte and the optical radiation, thereby improving spectroscopic performance. For example, in cavity ring-down spectroscopy (CRDS), the absorption is measured by way of its effect on the energy decay time of an optical cavity. Increased absorption decreases the decay time, and vice versa. As another example, cavity enhanced absorption spectroscopy (CEAS) entails the use of an optical cavity to increase the sensitivity of absorption spectroscopy, in connection with direct absorption measurements.
One of the noteworthy features of cavity-enhanced spectroscopy is that issues of optical alignment can arise which differ in important respects from alignment issues in other branches of optics. More specifically, a key alignment issue faced in many implementations of cavity enhanced spectroscopy is selectively exciting the lowest order mode of a passive optical cavity with an external optical source while minimizing excitation of the higher order modes of the cavity. The theoretical condition for providing such selective mode excitation is well known in the art, and is often referred to as “mode matching”. For example, suppose radiation in the lowest order mode of an optical cavity would be emitted from the cavity as a Gaussian beam having certain parameters (e.g., waist size w 0 , waist position z 0 ) along a beam axis L. In this example, radiation provided to the cavity as a Gaussian beam with waist size w 0 and waist position z 0 along beam axis L is mode matched to the lowest order mode of the resonator, and will selectively excite the lowest order mode of the cavity.
Although the theoretical condition for mode matching is well known, practical issues such as assembly tolerances and optical component tolerances can cause substantial difficulties. In this context, it is important to note that the passive cavity alignment problem is a much less forgiving single-mode alignment problem than the extensively explored problem of coupling to a single mode optical fiber or waveguide. The reason for this difference can be appreciated with a simple example where practical imperfections are assumed to cause a 1% loss of power coupled to the desired mode.
In the case of fiber or waveguide coupling, this 1% of the incident light that does not couple to the desired mode is lost from the system. There is typically no degradation of performance other than the 1% loss. In the case of coupling to a passive spectroscopic cavity, the 1% of the incident light that does not couple to the desired lowest order mode can couple to one or more of the higher order modes of the cavity. Such excitation of undesired cavity modes can seriously degrade spectroscopic performance, by effectively raising the noise floor. Such an effective increase in noise is typically a much more significant performance degradation than the 1% signal loss entailed by the above assumption.
Although the importance of achieving the mode matching condition is well known (e.g., as indicated in U.S. Pat. No. 5,912,790), specific methods for providing mode matching to a passive cavity in practice do not appear to have been explicitly considered in the art. US 2005/0168826 is an example where a somewhat related alignment problem is considered. In this work, an alignment system including a weak lens provides coupling of a source to a single mode waveguide. Coupling efficiency to the waveguide is enhanced by adjusting the position and angles of the weak lens during assembly. Another somewhat related problem of alignment has been considered in U.S. Pat. No. 6,563,583, where alignment is required to a multi-pass cell as opposed to an optical cavity. In this work, active feedback control is employed to measure and correct beam position and angle errors.
However, it is preferable to provide the level of alignment precision needed for cavity enhanced spectroscopy with an optical system having no moving parts, to reduce cost and simplify the resulting system. Accordingly, it would be an advance in the art to provide improved mode matching to a passive optical cavity while allowing for fabrication and assembly tolerances.
SUMMARY
Improved optical alignment precision to a passive optical cavity is provided by including a combination of a weak focusing element and a translation plate in the input coupling optics. Adjustment of positions and angles of these optical elements, preferably after all other input optical elements are fixed in place, advantageously provides for high-precision optical alignment to the cavity, without requiring excessively tight fabrication tolerances. Fabrication tolerances are relaxed by making the optical power of the weak focusing element significantly less than the optical power of a strong focusing element in the input optics. The position and angles of the beam with respect to the cavity can be adjusted, as can the size of the beam at the cavity. Differential adjustment of the beam size in two orthogonal directions (e.g., tangential plane and sagittal plane) at the cavity can also be provided.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cavity enhanced spectroscopy system according to an embodiment of the invention.
FIGS. 2 a - c show adjustment of beam position by tilting a beam translation plate.
FIGS. 3 a - f show adjustment of beam angle by laterally translating a weak lens.
FIGS. 4 a - c show adjustment of beam size by longitudinally translating a weak lens.
FIGS. 5 a - c show another example of adjustment of beam size by longitudinally translating a weak lens.
FIGS. 6 a - c show differential adjustment of beam size in the tangential and sagittal planes by tilting a weak lens.
DETAILED DESCRIPTION
FIG. 1 shows a cavity enhanced spectroscopy system 100 according to an embodiment of the invention. In this example, various optical components are affixed to a bench 102 . Bench 102 can be made of any sufficiently stable and strong material, and preferably has a low coefficient of thermal expansion (CTE). Accordingly, bench 102 preferably includes FeNi36, which is a generic designation for the steel alloy known in trade as Invar®. A first beam of optical radiation 130 is emitted from a fiber pigtail 106 coupled to an optical fiber 104 which receives radiation from a laser diode 103 . In this example, fiber 104 is preferably polarization-maintaining (PM) fiber, since it is desirable to fix the polarization of the first light beam. More specifically, it is preferable for the polarization to be TE at the cavity (i.e., electric field parallel to the surfaces of mirrors 116 and 118 ) because cavity loss can be made lower for TE polarization than for TM polarization, and for the polarization emitted from fiber 104 to be set accordingly. Isolator 112 , if present, may change the state of polarization, and any such change should be accounted for. It is also preferred for the end face of fiber pigtail 106 to be angled, to reduce back-reflection into source 103 along fiber 104 .
However, practice of the invention does not depend critically on details of the optical source configuration, and any source of spatially coherent single-mode optical radiation having a temporal coherence suitable for the kind of spectroscopy being employed (e.g., narrow linewidth for continuous-wave (CW) CRDS, wide linewidth for pulsed CRDS) can be employed. Suitable sources include, but are not limited to: lasers, diode lasers, standard single mode fiber (SMF) coupled lasers, SMF coupled diode lasers, PM fiber coupled lasers, and PM fiber coupled diode lasers.
First beam 130 is received by a strong focusing element 108 which provides a second beam 140 . Second beam 140 passes in succession through a weak focusing element 110 , an optional isolator 112 , and a translation plate 114 before impinging on resonator mirror 116 . Mirrors 116 , 118 and 120 form an optical resonator (also referred to as an optical cavity). In this example, the cavity is a ring resonator, as indicated by the cavity round trip path having segments 152 , 154 , and 156 . The resonator mirrors are affixed to a mechanical cavity housing 124 , which provides stable mechanical support to the resonator mirrors. Mechanical housing 124 can be made of any sufficiently stable and strong material, and preferably has a low CTE which is preferably matched to the CTE of bench 102 . Accordingly, mechanical housing 124 also preferably includes FeNi36 (Invar®). Radiation is emitted from the cavity as an output beam 160 , which is received by a detector 122 . The system of FIG. 1 is suitable for performing various kinds of cavity enhanced spectroscopy, such as cavity ring-down spectroscopy (CRDS) and cavity enhanced absorption spectroscopy (CEAS). It is also suitable for performing multi-pass absorption spectroscopy where the optical cavity is replaced by a multi-pass cell, since multi-pass cells often require precise input beam alignment. Multi-pass cells can often be treated as optical cavities for purposes of analysis
The example of FIG. 1 shows a specific cavity configuration for illustrative purposes, and practice of the invention does not depend critically on the resonator configuration. In particular, the invention is applicable to both ring cavities having three or more mirrors and to standing wave cavities having two or more mirrors.
The example of FIG. 1 also show an optional isolator 112 . The purpose of isolator 112 is to prevent optical feedback from the cavity from propagating back into fiber 104 and to source 103 , since such feedback can impair performance.
The cavity formed by mirrors 116 , 118 , and 120 has a lowest order mode and also supports one or more higher order modes. It is important for second beam 140 to selectively excite the lowest order mode while minimizing excitation of the higher order modes as much as possible. Accordingly, the combination of strong focusing element 108 and weak focusing element 110 should provide an exact or approximate mode match of second beam 140 to the lowest order mode of the optical resonator. In practice, achieving an exact mode match is typically not possible, so the approximate mode match is preferably made as close to exact as possible, given assembly and fabrication tolerances.
A key aspect of the present invention can be better appreciated by noting that it is possible, in principle, to mode match second beam 140 to the lowest order cavity mode using strong focusing element 108 alone, and omitting translation plate 114 and weak focusing element 110 . However, the resulting positioning tolerances on strong focusing element 108 tend to be unattainable in practice. Accordingly, a key idea of the present invention is that by introducing “extra” elements (i.e., weak focusing element 110 and translation plate 114 ), the assembly tolerances on the strong focusing element (and throughout the mode matching subsystem) can be relaxed, while still providing a very precise mode match of second beam 140 to the lowest order cavity mode. In particular, positions and angles of weak focusing element 110 and of translation plate 114 can be adjusted during assembly to minimize excitation of higher order modes (while coupling to the lowest order mode), preferably after the positions of the cavity, strong focusing element 108 , and fiber pigtail 106 have all been fixed.
To accomplish this purpose, it is important that weak focusing element 110 be weak relative to strong focusing element 108 . The optical power of an optical element (in diopters) is 1/f, where f is the focal length in meters. The focal length and power are positive quantities for positive focusing elements, and are negative quantities for negative focusing elements. Typically, strong focusing element 108 is a positive lens or mirror (e.g., a collimator) since it is typically preferable to approximately collimate the diverging beam provided by most optical sources prior to any other operations on the beam. In unusual situations, a negative strong focusing element 108 can be employed. Weak focusing element 110 can be either positive or negative. Let the optical powers of the weak and strong focusing elements respectively be denoted as d w and d s . Then |d w | is substantially less than |d s |, and preferably 0.01|d s |<|d w |<0.2|d s |.
The limits of the preferred range can be better appreciated by considering the following two cases. If the weak focusing element is too weak, its effect on the optical beam may be too small to provide the adjustment range required to compensate for assembly and fabrication tolerances, which is undesirable. However, if the weak focusing element is too strong, its alignment tolerances will be comparable to those of the strong focusing element, which is also undesirable. The alignment precision required for a focusing element to provide a given level of beam positioning precision at the cavity scales roughly as the focal length of the focusing element. Thus a weak focusing element having a focal length 10× the focal length of a strong focusing element will have roughly a 10× larger alignment tolerance than the strong focusing element.
Similarly, the translation plate 114 must be thick enough to provide adequate displacement of beam 140 through angular adjustment of the plate, but not so thick that the displacement is too sensitive to the angular adjustment. Usually, the surfaces of the translation plate will be parallel or nearly parallel, in which case rotation of the plate displaces the beam 140 but does not (significantly) change its direction. If the translation plate has a substantial wedge angle between the input and output surfaces, then rotation will change both the displacement and angle of beam 140 .
Translation of the weak focusing element 110 changes both the angle of beam 140 and its displacement at the cavity mirror. A pure change in angle at the cavity mirror is accomplished by simultaneous adjustment of the weak focusing element and the translation plate. Since the translation plate will usually have (nearly) parallel surfaces, a pure change in position of the beam at the cavity mirror is, in that case, accomplished by adjustment of only the translation plate.
Strong focusing element 108 can be a single optical element, or can be a combination of any number of optical elements (e.g., lenses and/or mirrors) having a “strong” optical power as described above. Similarly, weak focusing element 110 can be a single optical element, or can be a combination of any number of optical elements (e.g., lenses and/or mirrors) having a “weak” optical power as described above. It is preferable for strong focusing element 108 to be CTE matched to bench 102 . In one design, strong focusing element 108 includes two fused silica lenses in series and in close proximity, having a combined focal length of about 8 mm and acting as a collimator. In this design, the weak focusing element is a single lens which can have a focal length from about 20 mm to about 200 mm (or from about −200 mm to about −20 mm).
Translation plate 114 is a transparent plate having planar and parallel or nearly parallel input and output faces. The main purpose of translation plate 114 is to provide adjustment of the position of second beam 140 at the input to the optical cavity (i.e., at mirror 116 ). Translation plate 114 can be made of any optical material. Suitable materials include glass and fused silica.
In practice, the positions of fiber pigtail 106 , strong focusing element 108 and the cavity (i.e., mirrors 116 , 118 and 120 ) are preferably fixed during a first assembly phase. If isolator 112 is present, its position is preferably also fixed during the first assembly phase. The positions and angles of weak focusing element 110 and translation plate 114 are adjusted to minimize excitation of higher-order cavity modes in a second assembly phase. Such adjustment is preferably performed by lighting up fiber 104 to excite the cavity and directly measuring the excitation of the higher-order modes. Positions and angles of weak focusing element 110 and translation plate 114 can then be adjusted to minimize the measured excitation of higher-order cavity modes. Once a minimum level of higher order mode excitation is achieved, the positions and angles of elements 110 and 114 are fixed.
The combination of weak focusing element 110 and translation plate 114 advantageously provides a large number of degrees of freedom to employ in optimizing coupling to the lowest order cavity mode. We have found that such extra degrees of freedom are sufficiently helpful for optimizing cavity coupling to warrant the use of two elements for beam adjustment, even though the total number of optical elements could be reduced by employing only a single beam adjustment element.
Relevant degrees of freedom (DOF) include the following: a) angular pitch and yaw of adjustment plate 114 with respect to beam 140 , primarily for adjusting the lateral position of second beam 140 with respect to the cavity (2 DOF); b) lateral translation of weak focusing element 110 with respect to beam 140 , primarily for adjusting the pitch and yaw angles of second beam 140 with respect to the cavity (2 DOF); c) longitudinal translation of weak focusing element 110 with respect to beam 140 , primarily for adjusting the waist position of beam 140 with respect to the cavity (1 DOF); and d) angular pitch and yaw of weak focusing element 110 with respect to beam 140 , primarily for providing a differential adjustment of beam waist position relative to the cavity in the tangential and sagittal planes (1 DOF). FIGS. 2 a - 6 c show simplified examples of how these degrees of freedom can provide the adjustments indicated above.
FIGS. 2 a - c show adjustment of beam position by tilting a beam translation plate. In each of these examples, an input beam 204 passes through a translation plate 202 . Tilting of plate 202 displaces beam 204 by refraction at the input and output surfaces, by a distance equal to,
T sin θ ( 1 - cos θ n 2 - sin 2 θ ) ,
where T is the thickness of plate 202 , n is its refractive index, and θ is the angle of incidence on plate 202 , assuming the surrounding medium has refractive index of 1 (e.g. air or vacuum). The displacement of beam 204 is in the same plane as the angle of incidence. A wedge between the input and output surfaces, if present, only introduces an angular deviation of beam 204 in the plane of the wedge angle, approximately independent of the angle of incidence. FIG. 2 a shows an untilted translation plate 202 , so output beam 206 is undeviated with respect to input beam 204 . FIG. 2 b shows translation plate 202 having a clockwise tilt, so output beam 208 is shifted to the right with respect to input beam 204 . Similarly, FIG. 2 c shows translation plate 202 having a counter-clockwise tilt, so output beam 210 is shifted to the left with respect to input beam 204 . Such adjustment of the beam position can be done in both lateral directions (e.g., x and y directions for a z-propagating beam), thereby providing two degrees of freedom.
FIGS. 3 a - c show adjustment of beam angle by translating a weak focusing element. In each of these examples, an input beam 304 passes through a positive weak focusing element 302 . Translation of weak focusing element 302 changes the angle of beam 304 by an amount equal to, r×d w , where d w =1/f w is the power and r is the lateral displacement of weak focusing element 302 . The change in the angle of beam 304 is in the same plane as the translation of weak focusing element 302 . FIG. 3 a shows a centered weak focusing element 302 , so output beam 306 is undeviated with respect to input beam 304 . FIG. 3 b shows weak focusing element 302 shifted to the right with respect to beam 304 , so output beam 308 is tilted to the right with respect to input beam 304 . Similarly, FIG. 3 c shows weak focusing element 302 shifted to the left with respect to beam 304 , so output beam 310 is tilted to the left with respect to input beam 304 . Such adjustment of the beam angle can be done in both lateral directions (e.g., x and y directions for a z-propagating beam), thereby providing two degrees of freedom.
FIGS. 3 d - f also show adjustment of beam angle by translating a weak focusing element. In each of these examples, an input beam 304 passes through a negative weak focusing element 312 . FIG. 3 d shows a centered weak focusing element 312 , so output beam 306 is undeviated with respect to input beam 304 . FIG. 3 e shows weak focusing element 312 shifted to the left with respect to beam 304 , so output beam 308 is tilted to the right with respect to input beam 304 . Similarly, FIG. 3 f shows weak focusing element 312 shifted to the right with respect to beam 304 , so output beam 310 is tilted to the left with respect to input beam 304 . Thus the weak focusing element (e.g., 110 on FIG. 1 ) can be either positive or negative in practicing the invention.
FIGS. 4 a - c show adjustment of beam size by longitudinally translating a weak positive lens. In each of these examples, an input beam 408 is emitted from a strong focusing element 402 and passes through a weak focusing element 404 to provide an output beam. FIG. 4 a shows a weak lens 404 in a nominal position, and output beam 410 incident on cavity input coupler 406 (e.g., a mirror). FIG. 4 b shows weak lens 404 shifted toward strong focusing element 402 , thereby moving the waist of output beam 412 in the same direction. In this example, the beam size at input coupler 406 decreases. Similarly, FIG. 4 c shows weak lens 404 shifted away from strong focusing element 402 , thereby moving the waist of beam 414 in the same direction. Here the beam size at input coupler 406 increases.
It is also possible for the relation between the change of longitudinal position of lens 404 and the increase or decrease of beam size at input coupler 406 to be opposite to that shown on FIGS. 4 a - c . For example, FIGS. 5 a - c also show adjustment of beam size by longitudinally translating a weak positive lens. In each of these examples, an input beam 508 is emitted from a strong focusing element 402 and passes through a weak focusing element 404 to provide an output beam. FIG. 5 a shows a weak lens 404 in a nominal position, and output beam 510 incident on cavity input coupler 406 (e.g., a mirror). FIG. 5 b shows weak lens 404 shifted toward strong focusing element 402 , thereby moving the waist of output beam 512 in the opposite direction. In this example, the beam size at input coupler 406 increases. Similarly, FIG. 5 c shows weak lens 404 shifted away from strong focusing element 402 , thereby moving the waist of beam 514 in the opposite direction. Here the beam size at input coupler 406 decreases.
The principles of such beam shaping are well known to art workers, as are methods for detailed design for any particular case. In practicing the present invention, it is preferred for the longitudinal adjustment range of the weak focusing element to provide a range of beam waist positions that is sufficiently large to enable a match of beam waist size and location between the lowest order cavity mode and the beam incident on the cavity.
In some cases, the lowest order cavity mode may not have the same beam profile in the two transverse directions, e.g. as a result of fabrication tolerances and/or off-axis incidence on an optical surface inside the cavity. Such a cavity mode is astigmatic, so mode matching to such a cavity can be improved by providing an input beam that at least approximately has the same kind and amount of astigmatism. Astigmatism of second beam 140 can be provided in the embodiment of FIG. 1 by tilting weak focusing element 110 with respect to the beam. The astigmatism introduced by tilting a curved surface with respect to an optical beam is known in the art (e.g., as described in “Lasers” by Siegman on page 586). The need for such an astigmatic adjustment may also arise from an imperfect fiber facet or imperfect alignment of the strong lens 108 , causing beam 140 in FIG. 1 to have an elliptical cross-section and/or astigmatic focusing.
Such tilting of the weak focusing element can be regarded as providing a differential adjustment of beam size in the tangential and sagittal planes at the resonator input, as shown in the example of FIGS. 6 a - c . FIG. 6 a shows an untilted configuration, where beam 608 is emitted from strong focusing element 402 and passes through weak lens 404 to impinge on cavity input coupler 406 as beam 610 . FIGS. 6 b - c show tangential and sagittal views, respectively, of a configuration in which the weak lens 404 is tilted with respect to the beam. The profiles of the beam in the tangential plane ( 612 ) and the sagittal plane ( 614 ) differ (e.g., as shown), thereby providing a differential adjustment of beam size at cavity input coupler 406 . Alternatively, this can also be regarded as providing a differential adjustment of beam waist position relative to the cavity.
In this example, the tangential and sagittal planes are defined with respect to lens tilt as follows: the sagittal plane includes the axis of lens rotation, while the tangential plane is perpendicular to the axis of lens rotation. Thus for a z-propagating beam and a lens tilt that is a rotation about the y axis, the tangential plane ( FIG. 6 b ) is the x-z plane, and the sagittal plane ( FIG. 6 c ) is the y-z plane.
Methods for adjusting the positions and angles of elements 110 and 114 of FIG. 1 during assembly are well known in the art. Methods of fixing the positions of these elements once a configuration minimizing excitation of higher order cavity modes has been identified are also well known in the art. | Improved optical alignment precision to a passive optical cavity is provided by including a combination of a weak focusing element and a translation plate in the input coupling optics. Adjustment of positions and angles of these optical elements, preferably after all other input optical elements are fixed in place, advantageously provides for high-precision optical alignment to the cavity, without requiring excessively tight fabrication tolerances. Fabrication tolerances are relaxed by making the optical power of the weak focusing element significantly less than the optical power of a strong focusing element in the input optics. The position and angles of the beam with respect to the cavity can be adjusted, as can the size of the beam at the cavity. Differential adjustment of the beam size in two orthogonal directions (e.g., tangential plane and sagittal plane) at the cavity can also be provided. | 6 |
[0001] This application is a claims benefit of Serial No. MX/a/2012/000253, filed 2 Jan. 2012 in Mexico and which application is incorporated herein by reference. To the extent appropriate, a claim of priority is made to the above disclosed application.
FIELD OF THE INVENTION
[0002] The compound of biodegradable surfactants of the present invention has been produced for optimizing the separation of impurities usually found in hydrocarbons, and it is designed to intervene and stabilize the molecular structure of crude oil, without significantly altering its intrinsec composition.
[0003] Specifically, when the compound of the invention is injected into the reservoir it eliminates the inorganic components present in the aqueous phase while at the same time it regulates the generation of undesired compounds such as organic precipitates which are susceptible to changes in temperature, pressure and loss of volatile components.
[0004] The use at surface level of this compound, in addition to eliminating inorganic salts, dispersing asphaltenes and reducing wax content, adds aromatic compounds to the hydrocarbon chain. Further to the above, it reduces crude friction isolating it from the material through which it flows by displacing the crude adhered to the surface of said material. This principle allows the compound of this invention to be used industrially as a cleaner of any surface impregnated with crude, or even those contaminated with any other oily substance.
STATE-OF-THE-ART
[0005] Environmental impact caused by the use of contaminating chemical products is manifold. Damages are to be found in any area where man conducts production activities causing loss of materials, individual properties and furthermore, irreversible damages to the environment in water, land and air. The use of chemical products is, to a great extent, the origin of the imbalance of Nature's cycles which can indirectly affect human health, even to the point of causing death.
[0006] The use of these products in the oil industry is very frequent, both at surface level as well as down in the reservoir, and it usually implies the generation of hazardous waste. With this situation in mind the search for developing chemical products that reduce damages and minimize any kind of detrimental effect that may harm man or his environment is an ongoing activity.
[0007] Within this context several initiatives have been attempted to yield a safe product that causes no damage to the environment nor to man and that may be injected into oil wells for cleansing purposes while enhancing physical-chemical properties, and thus stimulating oil production.
[0008] In the process of searching for such a product several patent documents have been produced, among them U.S. Pat. No. 5,549,839 which discloses the formulation of a non-toxic, biodegradable and completely safe to human and animal contact industrial solvent. Said compound comprises d-limonene (73-74% v/v), an etoxilated nonylphenol (16-17% v/v) and fatty acids, namely tall-oil (9-10% v/v). The fatty acid reported in this document is made up of oleic and linoleic acids, among other substances. According to this document the forementioned product is mixed and applied directly and undiluted to an oil spill or other oil product residues such as greases and heavy crudes.
[0009] In spite of the advances presented in U.S. Pat. No. 5,549,839 for cleaning oil spills or other oil residues, the reported composition has no surfactant activity nor does it prevent the precipitation of clays or asphaltenes common in crude oil. Furthermore, the product disclosed in said patent must be applied undiluted to obtain the desired results, this implying that it must be used in large amounts to achieve the cleansing of hydrocarbons.
[0010] Another document that addresses the production of a cleansing compound comprising biodegradable components is U.S. Pat. No. 4,511,488. This patent claims a cleansing compound based on a terpene like d-limonene for cleaning heavy crudes, greases and asphalt deposits on hard or flexible layers. Said composition comprises 78 to 96% w/w of a mixture of limonene/surfactant/water in which the individual quantities in the mix are 10-60% w/w of limonene, 10-30% w/w of surfactant and 20-70% w/w of water.
[0011] According to said claim the compound would use 2-10 parts of a coupling agent and 2-12 parts of additives to adapt the compound for particular uses. Preferably the compound includes glycols, such as ether glycols like diethylene glycol, hexene glycol or dipropylene glycol. Preferred additives are softening agents, sequestering agents or corrosion inhibitors. Considered surfactants are anionic surfactants (especially amine salts of the dodecylbenzene sulphonic acid), or non-ionic surfactants like the alkylphenol condensates with 4-5 mols of ethylene oxide, particularly the nonylphenol condensate.
[0012] Just as in U.S. Pat. No. 5,549,839 the compound claimed in U.S. Pat. No. 4,511,488 has no surfactant activity, does not prevent clay or asphaltene precipitation and must be used undiluted. This implies higher costs which become higher when considering that the use of other additives is necessary, such as glycol ethers, softening and sequestering agents and corrosion inhibitors.
[0013] U.S. Pat. No. 5,336,428 must be included to complement the state-of-the-art information available. This patent refers to a compound for degreasing deep-sea off-shore oil drilling platforms made of a mix that comprises 5-7% w/w of limonene, 15-21% w/w of a non-ionic surfactant and 0.2-0.4% w/w of an acrylic copolymer as a densifying agent. According to said document preferred surfactants are polyethoxylated nonylphenol and the polymer of metacrylic acid and acrylate. In this case the compound is viscous and substantially clear. In similar fashion to the two previous patents mentioned before this compound cannot be used in undiluted form because effectiveness is lost. So being the case, the cost of using this product is high.
[0014] Considering all the above it becomes evident that in the state-of-the-art there is a need for a water-based product, biodegradable, highly efficient, fit to be used on crude oil and its derivatives for enhancing its physical-chemical properties, that optimizes flow within production pipelines both downhole and on the surface, that reduces and disperses organic precipitates, such as waxes and asphaltenes, breaks water-oil emulsions, minimizes organic salts and hydrogen sulphur contents, cleans oily sands and all kinds of surfaces, and that may even be used to reduce organic waste in the environment or for cleaning animals and birds that have become impregnated with oil because of oil spills.
DETAILED DESCRIPTION OF DRAWINGS
[0015] FIG. 1 . Percentage of biodegradability of the compound of the present invention.
[0016] FIG. 2 . Results of the toxicity test of the compound of the present invention taken at different hours.
[0017] FIG. 3 . Effects of the compound of the present invention on crude viscosity.
[0018] FIG. 4 . Effects of the compound of the present invention on emulsion breaking and oxidized organic precipitates.
[0019] FIG. 5 . Effects of the compound of the present invention as an enhancer of oil production.
DETAILED DESCRIPTION OF THE INVENTION
[0020] The biodegradable surfactants compound of the present invention is a chemical combination of a non-ionic surfactant and an organic mix in emulsion form. The purpose of this compound is to isolate crude from the tubing, reduce friction to improve crude flow and to enter the oil macromolecule to modify the hydrocarbon chain to reduce its density and thus its viscosity.
[0021] The biodegradable surfactants compound reported in the present application has been designed for its application on crude oil so that upon contact with the crude a weak emulsion is formed allowing for a very close interaction between the two; this interaction leads to the extraction of undesired contaminants; at the end the emulsion breaks thus improving the physico-chemical properties of the crude.
[0022] This action of the product within the production system is known as pseudoemulsion. This pseudoemulsion produces at its aqueous base an encapsulation of contaminants present thus facilitating their isolation from the reservoir and their removal from the system. Furthermore, the product is capable of generating a sliding effect between the rock pores, moisturizing it with the aqueous phase and improving oil relative permeability. Furthermore, the product will work in light and medium oil reservoirs, and achieved great results with heavy and extra-heavy crudes.
[0023] A feature of the biodegradable surfactants compound of the present invention is that it comprises sodium hydroxide 1N, potassium chloride, sulphonic acid, dodecanoic acid, nonylphenol, terpene-1 and water, preferably hard water.
[0024] The compound comprises 60-80% v/v of a mix that comprises 2.5-5.5% v/v of sodium hydroxide 1N, 2-4% v/v of potassium chloride, 5-15% v/v of sulphonic acid, 3-6% v/v of dodecanoic acid, 3-8% v/v of nonylphenol of 4-10 mols and hard water, and 20-40% v/v terpene.
[0025] Specifically, the sodium hydroxide 1N is incorporated into the formula of the invention to dissolve greasy organic compounds with a high molecular weight and to inhibit precipitation of asphaltic components.
[0026] Potassium chloride is used in the formula of the invention to prevent clay swelling. This component is added in low concentrations according to the environment in which it will be applied and for its use 7 kilos of potassium chloride are diluted in 150 liters of water.
[0027] Sulphonic acid performs as a surfactant in the product, its purpose being to reduce interfacial tension of the water droplets present in the emulsions that contain crude and to facilitate crude transportation, without altering physico-chemical properties. Its concentration in the compound of the invention is very variable. When used in the oil industry it is used at very low concentrations in organic solvents.
[0028] Dodecanoic acid is incorporated into the compound of the invention due to its stability and its linear chain which allow it to partially mix with oil and its derivatives, and because of its polar character which warrants that the combination will mix with water. In this formula its function is to stabilize molecular structure.
[0029] Another of the components of the formula of the invention is nonylphenol which has a varied function in the formula by allowing for the formation of a soft emulsion to join the organic and inorganic components, it being a good moisturizer and because it is a non-ionic surfactant it can clean surfaces that require the extraction of oil inorganic contaminants and mix them with water. Finally, terpene I is an excellent asphaltene dispersant and reducer of greasy components existing in oil, such as waxes. Its cyclic structure allows it to perfectly dilute in crude and in small water proportions. Preferably, terpene I is limonene terpene.
[0030] In one embodiment of the invention the compound optionally comprises one or more components selected from the group consisting of 8-14% urea, 3-8% sodium tripolyphosphate, 2-6% sodium sulphate, 3-6% liquid Genapol, and 1-4% of a quaternary salt.
[0031] The procedure for producing the compound of biodegradable surfactants of the present invention is also part of the claimed invention, and it comprises the following steps:
a. In a clean and dry mixer add an amount no less than 50% v/v of hard water measured against the total volume of the compound of the invention, then add 2.5-5.5% v/v of sodium hydroxide 1N and 2-4% v/v of potassium chloride. b. Then add 5-15% v/v of sulphonic acid, 3-6% v/v of dodecanoic acid, 3-8% v/v of nonylphenol of 4-10 mols and proceed to shake well until the mix is homogeneous. c. Once the solution is homogeneous complete the total volume to 100% v/v with hard water without stopping the shaking action. d. Turn the system off and let stand for 24 hours. e. Once the standstill period is over, take 60-80% v/v of the solution obtained in step d) and mix it with 20-40% v/v of terpene until a white homogeneous solution is obtained. The mixing process should be conducted during 30 minutes for amounts less than 200 liters. f. Let the product obtained in step e) to stand during at least 6 hours and then apply it following safety procedures suggested for its use.
[0038] Among the multiple applications of this compound the following are worth mentioning: formation cleaning for eliminating particles or deposits of precipitates, incrustations and such processes that tend to limit crude flow in the porous layers near the borehole; the extraction of waxes and other precipitates from crude oil; enhancing physico-chemical properties of crude oil, such as viscosity, gravity, water content, etc., and stimulation of oil production. Furthermore, depending on the concentration used, the compound of the invention is applicable to different kinds of crude oil, reservoirs of crude oil with different API gravities, oil production columns, crude oil pipelines, cleaning of flow stations, of bitumen, greases, oily sands and oil spill sites both on land and off-shore, remediation of oily waste pits, treatment of drilling muds, animal and vegetation cleaning.
[0039] The amount to be prepared will be estimated according to the projected use of the compound, whether at surface level or within the reservoir. Before preparing the formula an assessment of the types of contaminants and concomitants to be removed should be realized so as to determine the compatibility and concentrations for mixing the components comprised by the present invention. The concentration of each component of the formula is established according to the acid-basic character that is desired for the reaction to obtain the desired effect on the crude oil.
EXAMPLES
Example 1
Biodegradability Test
[0040] The compound of biodegradable surfactants of the present invention was subject to different biodegradability tests at the Environmental Engineering Laboratory of the University of Zulia with the purpose of confirming if it could be used safely without causing harm to the environment and furthermore, to see that said compound will be degraded when said compound is used as a degreaser or for stimulation of unreactive wells. Results shown in FIG. 1 show that the compound of the invention is 40.05% biodegradable after 28 days.
[0041] Additionally, Table 1 shows the results of analyses conducted following the method described in “Standard Methods for the Examination of Water and Wastewater”, 1999, 20th edition”, specifically by application of method 5210-B for determining the Biochemical Demand for Oxygen (mg/L) and method 5220-D for establishing the Chemical Demand for Oxygen (mg/L).
[0000]
TABLE 1
Results of analyses
DBO 5 , mg/L
30000
DBO 10 , mg/L
45000
DBO 15 , mg/L
65000
DBO 20 , mg/L
85000
DBO 28 , mg/L
95000
DBO 25 , mg/L
100000
DQO, mg/L
249680
Rate DBO 5 , mg/L
0.1201
Rate DBO 10 , mg/L
0.1802
Rate DBO 15 , mg/L
0.2603
Rate DBO 20 , mg/L
0.3404
Rate DBO 25 , mg/L
0.3804
Rate DBO 28 , mg/L
0.4005
[0042] Discussion of the results: the information reported in Table 1 clearly indicates that the compound of the present invention is biodegradable since the amount of matter susceptible to oxidation by biological sources is high as evidenced by the fact that after five days of reaction the DBO 5 was 30.000 mg/L and after 28 it increased to 100.000 mg/L.
Example 2
Toxicity Testing
[0043] A number of tests were conducted to establish the degree of toxicity of the compound of the present invention by determining its effect on fish in the Lake Maracaibo basin.
[0044] The method used for the toxicity test is the one described in “Standard Methods for the Examination of Water and Wastewater”, 1999, 20th edition. Basically the test consisted in running a toxicity bioassay to determine the lethal concentration of the compound of the present invention on the selected bioindicator. The calculated value is called “Mean Lethal Concentration (LC 50 ) and it corresponds to the concentration that causes death of 50% of the experimental sample after a certain time. Tables 2 through 5 showing the results of these tests are hereon included:
[0000]
TABLE 2
Concentration %
Control
10
25
50
75
100
pH
7.38
7.78
7.78
7.88
8.18
8.68
Dissolved oxygen ppm
4.06
5.06
5.09
4.98
4.60
4.58
Salinity (mg/L Cl*)
2000
2000
2000
2000
2000
2000
Observations at the
Fish are restless. They swim normally both horizontally as well as
beginning of testing
vertically. They permanently reach to the surface.
[0000]
TABLE 3
Number of survivors
10
10
10
10
9
9
(%) of Survivors
100
100
100
100
90
90
pH
7.86
8.07
7.98
8.01
8.03
7.89
Dissolved oxygen ppm
4.32
4.94
4.25
4.23
4.75
4.37
Observations during first
Dead fish were found at concentrations 75% & 100%; 1 and 1
24 hours of testing.
respectively. The rest of the fish in all concentrations swim
normally.
[0000]
TABLE 4
Number of survivors
100
91
90
90
99
99
(%) of Survivors
100
90
90
90
90
90
pH
7.96
8.03
8.12
8.14
8.15
7.95
Dissolved oxygen ppm
4.43
4.88
4.96
5.02
4.89
4.74
Observations after 48
Again dead fish were found at concentrations 10%, 25% & 50%;
hours of testing.
1, 1 and 1 respectively. The rest of the fish in all concentrations
swim normally.
[0000]
TABLE 5
Number of survivors
100
90
90
90
99
99
(%) of Survivors
100
90
90
90
90
90
pH
7.96
8.03
8.12
8.14
8.15
7.95
Dissolved oxygen ppm
4.43
4.88
4.96
5.02
4.89
4.74
Observations after 96
Again dead fish were found at concentrations 25%, 50%, 75% &
hours of testing.
100%; 1, 1, 1, 1 respectively and 1 in the control group. The rest
of the fish in all concentrations swim normally.
[0045] Likewise, FIG. 2 compiles the results of the toxicity tests conducted on the compound of the present invention. Conditions for these tests were:
[0000] Time intervals 24 h 48 h 96 h LC 50% — — —
Concentrations expressed as: %, mg/L; Others: % v/v
Species used in tests: Revistes
Temperature: 23.5±1.4° C.
[0046] Dillution water (characteristics): tap water dechlorinated with chloride salts to 2000 mg/L.
[0047] The procedure for sample preparation (recommended by the Venezuelan Institute of Crude Oil Technology—INTEVEP, in Spanish) comprises the following steps:
1. Compound added at the highest concentration required by the producer (10% v/v), 2. Mix well in a blender during 5 minutes, 3. Let the solution stand for 14 hours, 4. Once the oily, aqueous and sediment layers were separated the liquid (aqueous) part was taken aside to prepare the bioassay, 5. To conduct the toxicity test the following concentrations were taken from the liquid obtained: 100%, 75%, 50% and 10% of the diluted fluid.
[0053] The method used for the toxicity test was the one described in “Standard Methods for the Examination of Water and Wastewater”, 20th edition, 1999, identified as Method number 8010.
[0054] Discussion of results: it was not possible to determine LC50 in the test because the product did not produce a mortality of 50%.
[0055] The results of the toxicity assays show that the product did not produce a toxic lethal effect on the live species used (Levistes). It is worth pointing out that during the test a survival level of between 80% and 100% was obtained in all concentrations until the end of testing. This leads to the conclusion that the compound of the present invention is a non-toxic product and represents a low environmental risk when used at the concentration that should be used for application according to the requesting party, i.e. 10%.
Example 3
Reduction of Oils and Greases
[0056] The compound of the present invention also has an agglutinant effect. To determine the degree of this effect an assay was run with the purpose of determining the agglutinant properties that allow cleaning and recovery of crude oil spills in Lake Maracaibo caused by leaks in the production systems. This assay also allowed the determination of the amount of crude extracted from the waters when the compounds of the present invention come in contact with water.
[0057] For this test oil spills were simulated in four (4) experimental units. For the assays 800 mL of water were used to which 4 mL of the compound of the invention were added at different doses (1, 5 and 10%), and an experimental unit to which no product was added was used as control. Finally, after ten (10) minutes and after two (2) hours the amount of crude in water was measured in each of the experimental units.
[0058] Analyses were conducted according to “Standard Methods for the Examination of Water and Wastewater”. 20th Edition, 1999. The method specifically followed the parameters for Oils and Greases (mg/L) No. 5520-C. Results of the analyses conducted in the laboratory are shown in Tables 6 and 7.
[0000]
TABLE 6
RESULTS OF THE ANALYSES
Samples
Oils and Greases
10 minutes after applying product
(mg/L)
Unit 1: Water with crude; no product applied
2.81
Unit 2: Water with crude; product applied at 1.0%
0.85
Unit 3: Water with crude; product applied at 5.0%
0.72
Unit 4: Water with crude; product applied at 10.0%
0.58
[0000]
TABLE 7
RESULTS OF THE ANALYSES
Samples
Oils and Greases
2 hours after applying product
(mg/L)
Unit 1: Water with crude; no product applied
8.63
Unit 2: Water with crude; product applied at 1.0%
0.76
Unit 3: Water with crude; product applied at 5.0%
0.46
Unit 4: Water with crude; product applied at 10.0%
0.37
[0059] Discussion of results: results in Table 6 show that application of the compound of the present invention drastically reduces the concentration of oils and greases a few instants after adding the product at the different concentrations. Table 7 shows that after two hours in the experimental unit in which the product was not applied oils and greases have dissolved in a greater amount of water whereas in the units where the claimed compound was added no dispersion was observed and on the contrary, concentrations were lower than those seen 10 minutes after the addition of the product.
Example 4
Tests Regarding the Enhancement Effect on the Physico-Chemical Properties of the Crude
[0060] A SARA study (Saturates, Aromatics, Resins and Asphaltenes) was conducted to observe the effect of the claimed compound on a medium type crude from Eastern Zulia state. The study was done at the Institute of Petroleum Research of the University of Zulia (INPELUZ, acronym in Spanish). Table 8 reports water, sediments, and emulsion content of a sample taken from a canal that runs behind the tank station; no non-ionic surfactant was applied. Table 9 summarizes results of the SARA assessment of the original sample to identify its initial chemical properties.
[0000]
TABLE 8
RESULTS OF ANALYSIS OF THE ORIGINAL SAMPLE
CON-
SEDIMENTS
WATER
TAINER
(% v/v)
(% v/v)
EMULSION
SAMPLE ID
(GALLON)
ASTMD 96
ASTM D96
(% v/v)
PDVSA-
1
1.00
16.00
12.00
Bachaquero
Strong
Tank station
[0000]
TABLE 9
SARA ANALYSIS OF THE ORIGINAL SAMPLE
ASPHAL-
SATURATES
AROMATICS
RESINS
TENES
SAMPLE ID
(% w/w)
(% w/w)
(% w/w)
(% w/w)
PDVSA-
40.03
24.87
28.11
6.98
Bachaquero
Tank station
[0061] Table 10 reports water, sediments, and emulsion content of a sample taken from a canal that runs behind the tank station after applying the compound of non-ionic surfactant of the present invention, and Table 11 summarizes results of the SARA assessment of the crude mix with 5% of the claimed compound added to determine the chemical effects on the crude oil.
[0000]
TABLE 10
RESULTS OF ANALYSIS OF THE TREATED SAMPLE
CON-
SEDIMENTS
WATER
TAINER
(% v/v)
(% v/v)
EMULSION
SAMPLE ID
(GALLON)
ASTMD 96
ASTM D96
(% v/v)
PDVSA-
1
3.00
16.00
0.00
Bachaquero
Tank station
[0000]
TABLE 11
SARA ANALYSIS OF THE TREATED SAMPLE
ASPHAL-
SATURATES
AROMATICS
RESINS
TENES
SAMPLE ID
(% w/w)
(% w/w)
(% w/w)
(% w/w)
PDVSA-
40.36
32.04
22.04
4.90
Bachaquero
Tank station
[0062] Discussion of results: data in Tables 8-11 leads to the conclusion that the compound of the present invention completely breaks the emulsion. When the compound of the present invention is added the solids in the emulsion separate, as is clearly shown by the increase in sediment content.
[0063] Furthermore, results of the SARA chemical analyses (before and after treatment) show that by adding 5% of the claimed compound physico-chemical properties of the crude are enhanced on account of a substantial increase in aromatics, a fact that prevents precipitation of organic solids. It is evident that the application of this compound can break emulsions and separate organic and inorganic solids from the flow.
Example 5
Testing to Verify Enhancement of Crude Oil Fluidity Inside a Pipeline
[0064] The multiple tests run with the compound of the present invention evidence the double effect it has on crude, both downhole and at surface level, as said compound performs as a friction reducer by encapsulating crude and thus preventing its direct contact with the production line, and as a viscosity reducer by enhancing the intrinsec properties of crude. Results of said tests are shown below:
[0000]
TABLE 12
RESULTS OF SAMPLE ANALYSES
UNTREATED SAMPLE
Kinematic Viscosity @ 100° F. (CST)
7997.99
Kinematic Viscosity @ 180° F. (CST)
517.87
API gravity
10.8
Asphaltene content (% w/w)
10.32
Wax content (% w/w)
5.61
TREATED SAMPLE
Kinematic Viscosity @ 100° F. (CST)
1265.68
Kinematic Viscosity @ 180° F. (CST)
287.24
API gravity
12.80
Asphaltene content (% w/w)
6.32
Wax content (% w/w)
3.68
[0065] A similar test was run on a sample taken from a well in the Boscan field in the state of Zulia. The purpose was to observe the effect the biodegradable compound of the present invention had on the crude. Table 13 and FIG. 3 show the decrease in viscosity at different temperatures.
[0000]
TABLE 13
RESULTS OF SAMPLE ANALYSES
KINEMATIC VISCOSITY (CST)
ASTM D-445
SAMPLE COMPOSITION
80° F.
120° F.
180° F.
Original crude BN-766
21720.14
3709.81
517.87
Crude + 5% of product
3988.87
1361.53
287.24
[0066] Discussion of results: data in the referred table and figure lead to the assertion that the claimed compound increases the value of API gravity as evidenced by the increase from 10.8° to 12.8° API after adding the compound in a concentration of 5% v/v, equivalent to 51571.20 ppm. Furthermore, viscosity was lowered in a high percentage going from 21720.14 cps to 3988.87 cps after adding the compound in a concentration of 5% v/v. The test was conducted at 80° F.°. Furthermore, the compound mixed very well with the crude.
Example 6
Testing to Verify Reduction and Dispersion of Organic Precipitates Such as Waxes and Asphaltenes
[0067] For these tests a number of analyses were conducted in wells in the Bachaquero field, Zulia, to determine the effect of the compound on organic precipitates.
[0000]
TABLE 14
ANALYSES OF UNTREATED SAMPLES
SAMPLE ID
WAXES (% w/w)
ASPHALTENES (% w/w)
B-2342 (22-07-03)
11.45
4.32
B-2360 (22-07-03)
6.57
2.94
B-2364 (22-07-03)
10.36
4.65
B-2397 (22-07-03)
5.31
5.23
B-2401 (23-07-03)
8.59
6.32
[0000]
TABLE 15
ANALYSES OF TREATED SAMPLES
SAMPLE ID
WAXES (% w/w)
ASPHALTENES (% w/w)
B-2342 (22-07-03)
6.23
3.54
B-2360 (22-07-03)
3.96
2.66
B-2364 (22-07-03)
5.78
2.13
B-2397 (22-07-03)
3.24
3.99
B-2401 (23-07-03)
5.69
3.31
[0068] The following work was done by the company Biostar de Venezuela to determine the effect of the product on light oil from the center of Lake Maracaibo with the purpose in mind to use the product in the reservoir to stimulate production directly in wells. Results of these tests are shown in the following tables:
[0000]
TABLE 16
ANALYSIS OF UNTREATED SAMPLE
Water
EMULSION
ASPHAL-
(% w/w)
STANDARD
TENES
WAXES
WELL
ASTM D-4007
(% v/v)
(% w/w)
(% w/w)
CLA-0013
66.00
80.00 Strong
3.47
12.56
[0000]
TABLE 17
ANALYSIS OF THE SAMPLE ADDING 20%
OF THE COMPOUND OF THE INVENTION
Water
EMULSION
ASPHAL-
(% w/w)
STANDARD
TENES
WAXES
WELL
ASTM D-4007
(% v/v)
(% w/w)
(% w/w)
CLA-0013
66.00
0.00
3.36
4.64
[0069] Discussion of results: the tested sample contains a high concentration of wax as can be seen in Table 16. The high concentration of wax strengthens the emulsion and reduces the effectiveness of conventional demulsifiers. By adding the compound of the present invention the amount of wax decreased by 37% forcing emulsion break.
Example 7
Testing to Verify the Effect of the Compound of the Present Invention in Breaking of Water-Oil Emulsions
[0070] Following are the results of treating a crude sample from the Cumarebo field in northwestern Venezuela. The Cu-144 crude sample had an API gravity of 46.0°. The test was run to determine effects in reducing the emulsion present in the sample.
[0000]
TABLE 18
ANALYSIS OF UNTREATED SAMPLE
SEDIMENTS
WATER
(% v/v)
(% v/v)
EMULSION POR
SAMPLE ID
ASTM D-96
ASTM D-96
(% v/v)
Cu-144(12-11-03)
0.00
22.00
35.00 Strong
[0000]
TABLE 19
ANALYSIS OF TREATED SAMPLE
SEDIMENTS
WATER
(% v/v)
(% v/v)
EMULSION POR
SAMPLE ID
ASTM D-96
ASTM D-96
(% v/v)
Cu-144(12-11-03)
0.00
22.00
0.00
[0071] Discussion of results: the sample was subject to an emulsion analysis by centrifugation using 3% of the product. A quick reaction on the crude was observed and after centrifugation 100% of the emulsion had been broken.
[0072] A similar result was observed in the crude samples from Bachaquero, eastern Zulia. In that case the tests were run on samples of heavy and extra-heavy crudes. Results were excellent as shown in the following tables:
[0000]
TABLE 20
ANALYSIS OF UNTREATED SAMPLE
SEDIMENTS
WATER
(% v/v)
(% v/v)
EMULSION POR
SAMPLE ID
ASTM D-96
ASTM D-96
(% v/v)
B-2342 (22-07-03)
0.00
18.00
24.00 Débil
B-2360 (22-07-03)
0.00
0.40
0.80 Fuerte
B-2364 (22-07-03)
0.00
38.00
76.00 Fuerte
B-2397 (22-07-03)
0.00
48.00
50.00 Fuerte
B-2401 (23-07-03)
0.00
96.00
12.00 Fuerte
[0000]
TABLE 21
ANALYSIS OF TREATED SAMPLE
SEDIMENTS
WATER
(% v/v)
(% v/v)
EMULSION POR
SAMPLE ID
ASTM D-96
ASTM D-96
(% v/v)
B-2342 (22-07-03)
0.00
18.00
4.00 Débil
B-2360 (22-07-03)
0.00
0.40
2.80 Fuerte
B-2364 (22-07-03)
0.00
38.00
6.00 Débil
B-2397 (22-07-03)
0.00
48.00
0.00 Fuerte
B-2401 (23-07-03)
0.00
96.00
2.00 Fuerte
Example 8
Tests for Assessing the Effects of the Compound of the Present Invention in Reducing Organic Pollution Such as in Hydrocarbon Waste Pits
[0073] For this test, the physico-chemical characteristics of the samples were analyzed first and then it was decided to mix together samples from 8 different pits. The mix was divided into 5 parts and the product was applied at five different concentrations (3, 5, 10, 15 and 20%) to determine the effect on the pit sample and establish the possibility of using only one specific concentration. Results were that 3 of the 5 samples showed an effectiveness of 90-100% and the other 2 of 40%. Of the 3 samples with a 90-100% effectiveness only one was taken as a reference.
[0074] Next, pursuing the objectives set, it was decided to run complete analyses at the INPELUZ Maracaibo laboratories to establish the purity degree of the recoverable oil and thus discard any doubt on the possible consequences of incorporating the product to the pipeline carrying clean oil. The procedure developed by the INPELUZ Maracaibo laboratories follows bellow:
Take a two-liter sample from each pit (8 pits) Manually shake the samples to form a “compound sample”. In a 120 mL bottle add 90 mL of the mix+10 mL of the compound of biodegradable surfactants of the present invention. Shake during 10 minutes and let stand for 3 hours. Measure the water and sediment content and the interphase, and record the contents of the different phases. Add 5 drops of a universal emulsion breaker and record the data corresponding to the different phases.
[0081] Following are the results obtained in the test:
Results:
[0082] A). With the Composition Reported in this Application:
Water content: 15.30% Solids: 0.70% Oxidized organic precipitates: 10.0% Crude content: 74%
B). With the Universal Breaker:
[0000]
Water content: 25.30%
Solids: 0.70%
Oxidized organic precipitates: 10.0%
Crude content: 64%
[0091] A shown by the above results the difference is that water content is 10% greater with the Universal breaker and the crude content is 10% greater without the Universal breaker. FIG. 4 shows pipettes after having added the compound of the present invention and its contents shaken. The breaking of the emulsion and the oxidized organic precipitates are clearly observed as well as the sediments in the bottom of the pipette.
[0092] To conclude, the recommendation is that in view of the results obtained and its compatibility with the chemical demulsifiers this crude can be injected in a pipeline leading to a point where it will be mixed with another crude.
[0093] Another case to highlight is the testing conducted on samples from crude oil pits in Maturin, Eastern Venezuela, by the company Biostar, where the compound of the present invention recovered organic as well as inorganic sediments. Recovered organic sediments are reinjected into the crude production line whereas the inorganic sediments and sand may be returned to the environment with no harm of any kind to Nature or man.
[0000]
TABLE 22
ANALYSIS OF UNTREATED SAMPLE
Inorganic
Organic
Water
Emulsion
sediments
Sediments
(% w/w)
Standard
Well
(% v/v)
(% v/v)
ASTM D-4007
(% v/v)
OREO-5 pit,
0.40
0.45
13.00
10.00 Strong
MATURIN
[0000]
TABLE 23
ANALYSIS OF THE SAMPLE WITH 2.5% OF
THE COMPOUND OF THE PRESENT INVENTION
Inorganic
Organic
Water
Emulsion
sediments
Sediments
(% w/w)
Standard
Well
(% v/v)
(% v/v)
ASTM D-4007
(% v/v)
OREO-5 pit,
0.00
0.25
13.50
5.00 Weak
MATURIN
[0094] It is important to mention the use of the compound of the present invention by the company BiPetrol as a matrix non-reactive stimulator in well Samaria-824 in Villahermosa, Mexico. Before injecting the claimed compound the well produced 27 barrels of crude oil per day with a water cut of 24.00% v/v. The injection aimed at undoing the harm present and promote the necessary conditions to increase production.
[0095] FIG. 5 shows that after treating the well, production increased to more than 140 barrels per day with a water cut of 7.00% v/v, evidencing the effects of the compound when used within the reservoir. | Compounds of biodegradable surfactants useful for optimizing the separation of impurities typical of hydrocarbons, and designed to intervene and stabilize the molecular structure of crude oil, with no significant alterations of the crude's intrinsec composition are disclosed. The biodegradable surfactants compounds coexist with a non-ionic surfactant and an organic mix in emulsion form with the purpose of isolating crude from the pipeline, reduce friction to improve crude flow and to enter the crude macromolecule to modify the hydrocarbon chain to reduce its density and thus its viscosity; including compounds of biodegradable surfactants that comprise sodium hydroxide 1 N, potassium chloride, sulphonic acid, dodecanoic acid, nonylphenol, terpene- 1 and water, preferably hard water. | 2 |
TECHNICAL FIELD
The present invention relates to an optical communication arrangement and, more particularly, to an optical communication arrangement which can be used, for example, in a Local Area Network (LAN) wherein the entire microwave frequency bandwidth of the optical source-to-detector system is subdivided into separate non-overlapping frequency band channels and each user transmits and/or receives information either (a) on a separate fixed predetermined channel, (b) on a free channel selectively assigned using control signals transmitted on a control channel used by all transmitters and/or receivers, or (c) on a channel selectively chosen at a receiver associated with a user.
DESCRIPTION OF THE PRIOR ART
Semiconductor lasers and light emitting diodes (LEDs) can be modulated by direct current injection to provide an optical power output which is linearly proportional to the modulating current. An optical fiber can guide such modulated optical signal over many tens of kilometers with little distortion and complete noise immunity. Additionally, high speed photodetectors have excellent linearity and can be used at the receiver to reproduce an original information signal used for modulating the transmitter semiconductor laser or LED.
Lightwave information communication systems have taken many forms such as ring configurations used in Local Area Networks (LANs). For example, in the article "On Survivable Rings" by A. Beardsley et al in Telephony, Apr. 15, 1985 at pages 53, 56, 60, 62 and 64 the single-link n-nodes, star-shaped, and dual ring configurations were presented and discussed. Additionally, in LANs, various multiplexing and modulation techniques have been used to transmit information from each of the users to other users of the network without interference. One multiplexing technique commonly used is time division multiplexing of the packets of information from active users onto the optical bus. In such systems, either a central resource allocation device recognizes a service request from a user and assigns a free time slot to that user, or contention devices check activity in each time slot period and when a time slot is found free, the packet of information from the associated user is inserted into that time slot. In this regard see, for example, the article "The Experimental Broadband Network" by W. M. Hubbard et al. in Globecom '82, Nov. 29-Dec. 2, 1982, Miami, Fla. at pages D6.2.1-D6.2.2. Angular division multiplexing has been disclosed in, for example, U.S. Pat. No. 4,366,565 issued to G. J. Herskowitz on Dec. 28, 1982, for parallel optical signal transmission over a multimode optical fiber. Modulation techniques have included the use of, for example, spread spectrum coding to reject interference as disclosed, for example, in the article "Fiber Optic Bus With Spread Spectrum Techniques" by P. Pfeiffer et al. in Proceedings of SPIE, Fiber Optics in Local Area Networks, Vol. 434, Aug. 25, 1983, San Diego, Calif., at pages 20-23.
Prior art lightwave systems usually are found using baseband transmissions and, therefore, do not generally use all of the possible bandwidth available to the system. The problem in the prior art is to provide a simple lightwave communication system which provide maximum use of the available frequency spectrum while avoiding contention problems for multiple users of the system.
SUMMARY OF THE INVENTION
The foregoing problem in the prior art has been solved in accordance with the present invention which relates to a lightwave communication system which uses microwave modulation techniques to permit multiple simultaneous transmissions over the system in separate frequency band channels.
It is an aspect of the present invention to provide an optical communication system which can be used in, for example, a Local Area Network (LAN) wherein each user transmits and/or receives digital or analog information which has been used to intensity modulate an optical source so as to produce a signal occupying a separate predetermined frequency band of the overall frequency spectrum of the optical system. More particularly, in the present optical communication arrangement, the entire microwave frequency bandwidth of the optical source-to-detector system is subdivided into separate frequency channels and each user transmits and/or receives information either (a) on a separate fixed predetermined channel, (b) on a free channel selectively assigned via a head-end unit using control signals transmitted on a control channel used by all users, or (c) on a channel selectively chosen at a receiver associated with a user.
Other and further aspects of the present invention will become apparent during the course of the following description and by reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
Referring now to the drawings in which like numerals represent like parts in the several views:
FIG. 1 is a block diagram of an exemplary arrangement of a lightwave communication system according to the present invention;
FIG. 2 is a chart of a typical channel layout for use by the transceivers of FIG. 1;
FIG. 3 is a block diagram of an exemplary transmitter for a user of the system of FIG. 1 where a separate channel is fixedly assigned to each transceiver;
FIG. 4 is an exemplary arrangement of a head-end network unit for use in the system of FIG. 1;
FIG. 5 is a flow chart of a typical sequence used by controller 36 of the head-end network unit of FIG. 4;
FIG. 6 is a block diagram of an exemplary receiver arrangement for a user of the system of FIG. 1 where each user is fixedly assigned a separate channel;
FIG. 7 is a block diagram of an exemplary transmitter arrangement for use in the system of FIG. 1 where the channels are selectively assigned to a user;
FIG. 8 is a block diagram of an exemplary receiver arrangement for the system of FIG. 1 where the channels are selectively assigned to, or chosen by, the associated user; and
FIG. 9 is a block diagram of a broadcast optical communication system where each user can selectively receive any one of K multiple channel broadcasts.
DETAILED DESCRIPTION
The description which follows is directed to an optical fiber communication system. However, it is to be understood that any reference to an optical fiber can equally be directed to the use of a free-space optical transmission system or some combination thereof as shown in FIGS. 1 and 9.
FIG. 1 is a block diagram of an exemplary arrangement of a lightwave communication system in accordance with the present invention which permits each of a plurality of N users of the system to communicate with one another or with other persons or devices reachable via a communications network external to the present system. Alternatively, the present lightwave communication system could be used for broadcasting many channels of information to each user or subscriber, with the individual users selecting which channel they wish to receive information from.
In the arrangement of FIG. 1, each of users 1-N has associated therewith a separate transceiver 10 1 to 10 N , respectively, with each transceiver 10 i comprising a transmitter 11 and a receiver 12. In the present arrangement, the entire microwave frequency bandwidth of the optical source-to-detector system is divided into a plurality of, for example, N separate channels as shown in FIG. 2. In one embodiment of the present invention, each of transceivers 10 1 to 10 N is fixedly assigned to a separate one of the N channels, which configuration reduces the complexity of each transceiver. It is to be understood that the present invention can also include alternative embodiments wherein each of (a) transmitters 11 of transceivers 10 1 to 10 N , and/or (b) receivers 12 of the transceivers, can be selectively assigned to any one of the N channels. In the alternative embodiment (a) above, each transmitter 11 can be directed to a free channel via either (a) control signals from a central network unit or (b) the use of any suitable known contention resolution technique for determining an inactive channel. This latter embodiment, however, increases the cost and complexity of each transceiver since each transceiver must be capable of generating all of the possible carriers of the N channels either selectively, at each transceiver, or automatically in response to control signals from either the central network unit or from included contention resolution means.
In the arrangement of FIG. 1, transmitters 11 of transceivers 10 1 to 10 N have their outputs connected to an optical fiber 13 via directional optical couplers 14 1 to 14 N , respectively. Each of the optical couplers 14 i is arranged to couple the information signals from the associated user transmitter 11 into fiber 13 for propagation in the same direction as the information signals coupled into fiber 13 by all other users, which information signals are directed towards an optional head-end network unit 15. Optional head-end network unit 15, when present, functions to gate the signal from each of transmitters 11 received on fiber 13 in the separate channels to either (a) an optical fiber 16, for any local calls within the system, or (b) to the external communications network, after performing any necessary processing as will be explained in greater detail hereinafter. When head-end unit 15 is not present, then the signals on optical fiber 13 are directly connected to optical fiber 16. The output signals from head-end network unit 15, propagating on fiber 16, are directed towards receivers 12 of transceivers 10 1 to 10 N by optical couplers 17 1 to 17 N , respectively. Receivers 12 function to demodulate only those signals received in the channel associated with its transceiver and reject the signals in all other channels. The output signal from each receiver 12 is then provided to the associated user. It is to be understood that the linear arrangement of optical fibers 13 and 16 shown in FIG. 1, and the alternative arrangement of FIG. 9 to be explained hereinafter, is only provided for simplicity of explanation of the present communication system. It is to be further understood that in actuality fibers 13 and 16 most probably would include, for example, combiners or dividers, respectively, to provide optional paths in an arbitrary tree type distribution system with each path including one or more optical couplers as shown, for example, in FIG. 1 for user 3. Such tree type distribution system would ease the routing of optical fibers 13 and 16 in, for example, a building or amongst buildings, if necessary. Alternatively, certain of the users could be supplied the output signal from head-end network unit 15 via a free space optical link 19 a , and head-end unit 15 could receive transmissions from such user via free space optical link 19 b . For a user using such free space optical link, the transmitter 11 and receiver 12 could transmit and receive the optical signal directly to and from head-end network unit 15. For this reason, optical couplers 14 3 and 17 3 associated with user 3 is only needed when such user connects to optical fibers 13 and 16, respectively.
FIG. 3 is a block diagram of an exemplary transmitter 11 for use in the hereinbefore mentioned preferred embodiment where each of transceivers 10 1 to 10 N is permanently assigned a separate one of the channels 1-N shown in FIG. 2. In operation, a modulator 20 which can comprise any suitable modulator but hereinafter will be considered as using a voltage tuned oscillator (VTO) 20, is responsive to a DC control voltage applied at its input to generate a particular carrier frequency ω i . It is to be understood that by changing the value of the DC voltage applied to a VTO 20, a corresponding change in the output frequency is obtained as is well known in the art. The different value of DC control voltage needed for each VTO 20 of transceivers 10 1 to 10 N to generate the associated assigned carrier frequency can be obtained either from separate DC sources, from a central DC source or from some combination of sources, depending on the location of each of the transceivers and the users of the system.
Concurrently, a digital data or information input signal from an associated user is also applied, via a capacitance 22, to the input of VTO 20 to, for example, Frequency Modulate (FM) the assigned carrier frequency ω i and transmit the digital data or information signal in the channel designated by the carrier frequency ω i . For example, it will be assumed that transmitter 11 of transceiver 10 1 has applied to it a DC control voltage of a value which will generate the carrier frequency ω 1 in associated VTO 20; transmitter 11 of transceiver 10 2 has applied to it a DC control voltage of a value which will generate the carrier frequency ω 2 in associated VTO 20; and transmitter 11 of transceiver 10 N has applied to it a DC control voltage of a value which will generate the carrier frequency ω N in associated VTO 20. The output signal from VTO 20 is used to directly modulate an optical source 21, which can be, for example, a semiconductor laser diode or any other suitable lasing means, an LED, or the output signal can be used to drive an external light intensity modulator like a Lithium Niobate electro-optic modulator or Multiple Quantum Well modulator. As a result, optical source 21 is intensity modulated at the assigned microwave channel frequencies received from the associated VTO 20. The optical output signal from optical source 21 is transmitted over an optical link to the associated optical coupler 14 i for transmission to head-end network unit 15 via fiber 13.
For the embodiment where each of transceivers 10 1 to 10 N is assigned a separate fixed carrier frequency ω i , head-end network unit 15 functions to (a) receive each active channel frequency band, (b) determine where each channel is to be transmitted (to another local user to to the external network), (c) convert the received channel frequencies (1) to a proper channel frequency of a destined local user of the system or (2) to, for example, a baseband digital signal of the external network, and (d) gate such signal to optical fiber 16 for transmission to a destined local user, or to guiding means 18 for transmission over the external network. An exemplary arrangement of head-end network unit 15 for this embodiment is shown in FIG. 4. There, the multiple channel signals on fiber 13 are received by a photodetector 30 which functions to convert the lightwave signals on fiber 13 into corresponding electrical signals.
The multiple electrical channel signals at the microwave frequencies are concurrently transmitted to a bank of N channel filters 31 1 to 31 N . Each filter 31 i functions to pass only the signal within the separate associated channel frequency band and reject all others. For example, filter 31 1 passes only the frequency band associated with channel 1 associated with exemplary transceiver 10 1 ; filter 31 2 passes only the frequency band associated with channel 2 associated with exemplary transceiver 10 2 ; and filter 31 N passes only the frequency band associated with channel N associated with exemplary transceiver 10 N . The outputs from filters 31 1 to 31 N are transmitted to demodulators 32 1 to 32 N , respectively. Each of demodulators 32 1 to 32 N functions to convert the microwave electrical signals of the particular frequency band passed by the associated filter 31 i into a baseband digital signal. Demodulators are well known in the art and any suitable arrangement such as a Phase Lock Loop or, for an FSK modulated signal, a limiter-discriminator can be used for the demodulators 31 of FIG. 4. The output signals from demodulators 32 1 to 32 N are terminated at separate inputs 33 1 to 33 N , respectively of a gating (or switching) means 34.
Gating means 34 functions to interconnect (a) any of inputs 33 1 to 33 N to either the external network via guiding means 18 or to outputs 35 1 to 35 N , and (b) the external network to any one of outputs 35 1 to 35 N , in response to appropriate control signals from a controller 36. Controller 36 includes a memory 37 which stores the program and scratch pad memory for (a) keeping track of existing cross-connections, (b) finding appropriate paths through gating means 34, and (c) closing paths through gating means 34 when a call is initiated or opening paths when a call is terminated, as is well known in the art. Controller 36 can comprise a microprocessor or computing means which receives origination and destination addresses at the start of a call and, as shown in the flow diagram of FIG. 5, sequences through memory 37 for inactive paths from the appropriate input to the desired output. If such path is found, controller 36 transmits appropriate control signals to close the appropriate gates or switches in gating means 34 and complete the path. It is to be understood that originaion and destination address information can be transmitted on a separate common signaling channel from transceivers 10 1 to 10 N and the external network. With such form of signaling arrangement, a separate signaling channel filter 38 and associated demodulator 39 would be required having its input from photo-detector 30. Similarly, the signaling information would have to be provided to controller 36 from the external network via a lead 40. Alternatively, the origination and destination address information could be transmitted in a preamble or postamble section of a packet of information as is well known in the art. With such arrangement, the outputs of demodulators 32 1 to 32 N and the external network could be directly connected to controller 36 via lead or bus 40.
The outputs 35 1 to 35 N from gating means 34 are coupled to Modulators 41 1 to 41 N , respectively. When modulators 41 1 to 41 N are, for example, Voltage Tuned Oscillators (VTOs) they are responsive to separate associated DC voltage levels for modulating the input signal from gating means 34 into the frequency band of channels 1-N, respectively, in the manner described for VTO 20 in FIG. 3. More particularly, VTO 41 1 generates the carrier frequency ω 1 in response to a DC voltage level and modulates this carrier frequency with the input signal from output 35 1 of gating means 34 to provide an output signal in the frequency band of channel 1. VTOs 41 2 to 41 N function in a similar manner using carrier frequencies ω 2 to ω N , respectively, to produce output signals in respective channels 2-N.
The individual channel 1-N output signals from VTOs 41 1 to 41 N are combined in combiner 42 and the combined output signal is provided as an input signal to optical source 43. Optical source 43 can comprise any suitable semi-conductor laser or other means, as described hereinbefore for optical source 21 of FIG. 3, which is intensity modulated by the input signal from combiner 42. The output lightwave signal, including the combined information of channels 1-N is transmited along fiber 16. It is to be understood that although it is possible to combine all of the signals from VTOs 41 1 to 41 N in a single combiner 42, it is also possible to combine subsections of these VTO outputs such as, for example, the outputs of VTOs 41 1 to 41 2 in combiner 42, and the outputs from VTOs 41 3 to 41 N in a combiner 44. The outputs from combiners 42 and 44 can then be either combined as a single input to optical source 43, or the outputs from combiners 42 and 44 could be provided as separate inputs to optical source 43 and 45, respectively, with the output signals from optical sources 43 and 45 being combined in an optical combiner 46 for transmission on optical fiber 16 and/or free space link 19.
As shown in FIG. 1, the output channel signals from head-end network unit 15, propagating along optical fiber 16, reach optical couplers 17 1 to 17 N in sequence. Each of couplers 17 i functions to direct a portion of the signal propagating along fiber 16 to receiver 12 of the associated transceiver 10 i . A typical arrangement for a receiver 12 for the embodiment where each transceiver 10 1 to 10 N is assigned a fixed separate one of the channels 1-N is shown in FIG. 6.
In the receiver of FIG. 6, the input signal from the associated optical coupler 17 i is received in a photo-detector 50 which converts the lightwave signal of received channels 1-N into a corresponding electrical signal at the microwave frequency of the associated channels. The electrical output signal from photodetector 50 can be amplified to a proper level in amplifier 51 and applied to the input of a bandpass filter 52. Bandpass filter 52 functions to pass only the signals in the channel assigned to associated transceiver 10 i and reject all other channel signals. For example, for the exemplary case of trasnceiver 10 1 being assigned to transmit and receive on channel 1, filter 52 of receiver 12 of transceiver 10 1 would pass only the received frequency band of channel 1 and reject all other channel signals. The channel signal from filter 52 is passed through a demodulator 53 (e.g., a PLL or a limiter discriminator for use with FSK modulated signals) to convert the microwave electrical signals from filter 52 into a baseband digital signal for use by the associated user. Where, in al alternative embodiment, signaling is performed in a separate signaling channel from that of channels 1-N, then receiver 12 could also include a separate bandpass filter 54 which only passes the frequency band of the signaling channel and rejects all other, so that the signaling information can be sent to the associated user after passing through a separate demodulator 55.
FIG. 7 is a block diagram of an exemplary arrangement of a transmitter 11 of FIG. 1 for the embodiment where the channels 1-N are selectively assignable. Transmiter 11 is shown as comprising a VTO 20, optical source 21, and a capacitance 22 which function in the manner described for corresponding components in FIG. 3. Transmitter 11 further comprises a gating means 60 and a controller 61. Gating means 60 functions to provide the appropriate DC control voltage to VTO 20 for the channel assigned to transmitter 11 under the control of controller 61. For example, if it is assumed that the system uses a separate channel for signaling purposes to head-end network unit 15, then an off-hook signal from the associated user is detected by controller 61 which closes gating means 60 to permit the DC control voltage that will generate the control channel (e.g., Channel X) in VTO 20 to be applied to VTO 20. The user then send the origination and destination address via VTO 20 and laser 21 to head-end network unit 15. At head-end network unit 15, its controller 36 receives the origination and destination addresses via photo detector 30, band-pass filter 38 and demodulator 39, and finds a free channel. This information is transmitted via fiber 16 to the receiver 12 associated with transmitter 11 and is received from receiver 12 in controller 61 of transmitter 12 via lead 62. Controller 61 then opens the path for the DC control voltage associated with the control channel and closes a path which will apply the DC control voltage to VTO 20 that will transmit the data information from the user in the assigned free channel. At the conclusion of a call, an on-hook signal in, for example, a preamble section of a transmission to head-end network unit 15, is also received by controller 61 from the user via lead 63 and is recognized as a termination control signal. In response thereto, controller 61 opens the path through gating means 60 for the DC control voltage used for the assigned transmission channel, and head-end network unit 15 releases its path through gating means 34 and updates its memory 37 to indicate both the free path and that the assigned channel is now free for subsequent assignment.
The arrangement of FIG. 7 is also usable in the arrangement of FIG. 1 where optional head-end unit 15 is not used, and optical fibers 13 and 16 are interconnected in a Local Area Network (LAN) arrangement. More particularly, in such LAN arrangement, each receiver 12 can be fixedly or selectively assigned to a separate one of channels 1-N, using, for example, the exemplary arrangement of FIG. 6 or FIG. 8. With such arrangement, a user desiring to communicate with a certain other user provides the appropriate destination address information to the associated controller 61 via lead 63. Based on the destination address provided, controller 61 causes the closing of the proper path through gating means 60 in order to apply the appropriate DC control voltage to VTO 20 for transmitting the information in the correct channel capable of being received by the receiver of the destined user over optical fibers 13 and then 16.
FIG. 8 is an alternative arrangement of receiver 12 wherein the input signal from coupler 17 i passes through photo detector 50 and amplifier 51, which function as described for the corresponding components of FIG. 6. The output signal from amplifier 51 is provided as a first input to a mixer 70. A second input to mixer 70 is provided by a VTO 71 whose output frequency is determined by the value of an input DC voltage. A DC voltage selecting means 72 selectiely provides any one of a plurality of 1-N (or 1-N and X) different DC control voltages to VTO 71 under the control of control means 73. More particularly, by selecting a predetermined one of 1-N DC voltage output values, VTO 71 will generate a corresponding output frequency with which Mixer 70 mixes the input signals from coupler 17 i and VTO 71 to generate an output signal where the desired channel is always within a predetermined passband. A fixed bandpass filter 74 only passes the predetermined passband which contains the desired channel. The desired channel signal is the demodulated in demodulator 53 for transmission to the associated user. For the alternative arrangement wherein head-end unit 15 transmits control signals on, for example, channel X for indicating to a user which channel is assigned to that user for communication, then during the period where such reception of channel X is indicated control means 73 can cause DC voltage selecting means 72 to generate a DC voltage for causing VTO 71 to generate the appropriate frequency for Channel X. The resultant control signal can then be passed through bandpass filter 74 and demodulator 53 to the associated transmitter 12 so that transmitter 12 transmits on the assigned channel.
An alternative embodiment of the optical communication system of FIG. 1 is shown in FIG. 9 which forms a broadcast system where the associated users, 1-N, are each capable of simultaneously receiving, for example, a plurality of K differet channel broadcasts and randomly selecting any one of the channels. As shown in FIG. 9, the broadcast system includes a head-end network unit 15 which receives the 1-K different program input signals and applies them as inputs to modulators 41 1 to 41 K which can incude any suitable modulator but for purposes of explanation will be considered hereinafter as VTOs 41 1 to 41 K , respectively. Each VTO also has applied to its input a separate DC control voltage, such that VTOs 41 1 to 41 K transmit on channels 1-k, respectively. The outputs from VTOs 41 1 to 41 K are combined in combiner 42, and the combined signal is applied to optical source 43 for intensity modulating the optical source, as was described previously for the corresponding elements of FIG. 4. The output from optical source 43 is transmitted along optical fiber 16 and distributed to each of receivers 12, associated with a separate user 1-N, by optical couplers 17 1 to 17 N , as described hereinbefore for the corresponding elements of FIG. 1. As explained hereinbefore in FIG. 1, head-end network unit 15 could transmit the signal from combiner 42 via a free-space transmitter 80 and optical link 19 a to a user i. Each of receivers 12 has a configuration similar to that shown in FIG. 8, except that controller 74 can be manually or remotely controlled by the associated user to randomly select a particular channel of the K received channels, as might be found in a radio or television receiver. | The present invention relates to an optical communication system wherein the entire microwave frequency bandwidth of the optical source-to-detector system is subdivided into a plurality of non-overlapping frequency bands or channels, and each user transmits and/or receives information either (a) on a separate fixed one of the channels, (b) on a free channel selectively assigned via control signals transmitted on a separate control channel at the time of initiation of a communication, or (c) on a channel randomly selected at the receiver by an associated user to receive a particular program. The present optical communication system can be configured to simultaneously broadcast multiple programs over separate channels for random selection by each user, or to achieve local and/or external two-way communications with the associated system users. | 7 |
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention concerns a method of connecting pipe members for a variety of purposes including (but not limited to) plumbing, hydraulics, pneumatics and medical purposes. The invention also includes a connector which is suitable for connecting pipe members for the suggested purposes, and which is also able to be used in conjunction with other fittings for these purposes.
2. Description of the Prior Art
A wide variety of connectors are known for the above mentioned purposes in which a variety of different types of pipe and tube are used depending upon the particular purpose. Because of its versatility, the use of plastics pipe and tubing is increasing in use for the above described purposes. It is considered that it would be advantageous to provide a plastics connector usable in conjunction with pipe members and tubing in which it was not necessary to use tools to effect connection beween the connector and the pipe. It is also considered that it would be useful to provide a connector which was adapted to make proper connection with a wide variety of pipes without any requirement for working of the pipe to make a proper connection.
The connectors presently known have often included a male and female type coupling by way of a thread or other interlocking designs. Alternatively, the pipe member is forced over a nipple on a male connector which often causes damage to the pipe. In other embodiments, a compression type fitting is used whereby a collet member is compressed by a backing nut onto the pipe wall. In general, connectors of these types have been of a design and construction requiring a large number of different types of connectors for various different purposes. Furthermore, the commonly used compression fittings do not compensate for subsequent creep in the pipe so that an inadequate grip on the pipe can result in a continuous use application.
The provision of a connector according to this invention envisages a plastics connector member of a simple design which is adaptable for a wide variety of purposes and for a range of diameters of pipes or tubes.
BRIEF SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a method of engaging a pipe or tube in a connector member, and a connector member, which goes at least some way to overcoming the disadvantages which have been found in methods of connecting and connector members known in the art. The invention also provides an improved connector member for fitting with pipes or tubes of a substantially round cross section and whether or not they include a generally smooth surface. Other objects and advantages of this invention will become apparent from the following description. It is also an object of the invention to provide a connector member manufactured of plastics material which is of a simple yet efficient design, and which may be economically mass produced.
According to a first aspect of this invention there is provided a connector including a connector body with an opening at one end and a tapered bore of a diameter increasing from the opening extending in the direction of its longitudinal axis, and a substantially coaxial inner sleeve of plastics material positioned in the connector body, the inner sleeve being of a substantially frusto-conical shape substantially complementary to the bore in the connector body and including a bore extending in direction of its axis having a substantially rounded cross section and being smaller than or corresponding to that of a pipe to be located in the connector, the connector providing that a pipe inserted into the bore in the inner sleeve of the connector, can be moved in the opposite direction to the direction of insertion so that the inner sleeve will wedge into frictional engagement and connection to the surface of the pipe and the inner surface of the connector body, to engage the pipe in the connector.
According to a further aspect of this invention there is provided a method of locating a substantially round (in cross section) pipe member in a connector, the connector including a connector body with an opening at one end and a tapered bore of a diameter increasing from the opening extending in the direction of its longitudinal axis, and a substantially coaxial inner sleeve of plastics material positioned in said connector body, the inner sleeve being of a substantially frusto-conical shape substantially complementary to the bore in the connector body and having a bore extending in the direction of its axis with a substantially rounded cross section being smaller than or equal to that of a pipe to be located in the connector, the method including inserting a pipe into the bore and into frictional engagement with the inner sleeve of the connector, and subsequently withdrawing the pipe in the opposite direction to insertion whereupon the inner sleeve member is wedged into frictional engagement and connection to the pipe and the inner surface of the connector body to complete engagement of the pipe in the connector characterized in that the frictional co-efficient (or the frictional resistance to movement) between the pipe and the inner sleeve exceeds the frictional co-efficient between the inner sleeve and the connector body.
In a first preferred embodiment the connector body includes an inwardly depending lug(s) member(s) adapted to extend into any one or more or the recesses in the inner sleeve, the arrangement being such that the inwardly depending lug or lugs are removably engagable in any one or more or the recesses in the inner sleeve to prevent or enable movement of the inner sleeve within the connector body which respectively prevents or enables the inner sleeve to be wedged into frictional engagement between the pipe and the connector body, the arrangement providing for the pipe to thereby be engaged or disengaged in the connector as may be required.
In preferred embodiments the inner surface of the inner sleeve member includes at least one preferrably circumferential tooth member which is adapted to engage the surface of the elongate pipe.
In preferred embodiments, a continuous upstanding ridge portion is provided about the inner surface of the inner sleeve as a continuous tooth member adapted to engage the surface of the elongate pipe.
In preferred embodiments, the connector member of the invention may be adapted to be assembled with, or engaged or connected to one or more other connectors to provide a standard pipe joint, a `T` junction, or a multiple junction of the connector and other fittings.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention, which should be considered in all its novel aspects, will now be described by way of example only, and with reference to preferred embodiments as shown in the accompanying drawings wherein:
FIG. 1 is a part cut away cross-sectional view of a connector member according to one preferred embodiment of the invention, and when used as a pipe joining connector and including an automatic shut-off valve in a `T` junction; and
FIG. 2 is an enlarged perspective view of the inner sleeve according to one preferred embodiment of the invention.
DETAILED DESCRIPTION
The connector according to the present invention has particular use in relation to the connection of elongate pipe or tube of a substantially round cross-section-generally of a diameter of up to say 100 mm although this should not be considered as a limitation of the application of the invention. In one preferred form of the invention the connector will be used in conjunction with plastics pipe which has particular application in relation to the medium or high pressure water supply and irrigation systems utilizing polyethylene or other similar flexible plastic pipe. In this example the pipe diameter would be approximately 15-50 mm. In other embodiments and applications of the invention it is envisaged that the connectors could be used upon metal pipes of all types and particularly where it is desirable to removably engage and locate a connector on a pipe or tube without the necessity for tools or to work the actual pipe or tube.
The invention provides a connector to which a pipe may be conveniently engaged (and in preferred embodiments disengaged), and which has a wide variety of uses. The invention will be described with reference to the preferred embodiments as shown in the drawings in which the connector provides a connection between two adjacent lengths of elongate pipe, with a third outlet being provided as an automatic shut-off valve. This is however only one possible application of the invention.
In the preferred embodiment the connector generally indicated by 30 is referred to as the assembled, or complete, device which functionally together with all parts thereof achieves the connection, the connector body is the element having the frusto-conical shaped outer part 10, and the inner sleeve member 1 is an elongate plastics member of a substantially frusto-conical shape as shown in FIG. 2 of the drawings including an axial bore (x--x) of a diameter generally less than or equal to the diameter of the pipe or tube to be engaged in the connector. The inner surface (b) of the inner sleeve member is thus adapted to make some frictional adhesion to the surface (a) of the pipe 20 because of the natural pre-tension of the inner sleeve when fitted on the pipe. The outer surface (b) of the inner sleeve member is provided with a preferably constant taper throughout its length from one end to the other at an (included) angle within the range of 1-7 degrees, and in the example shown of approximately 4 degrees.
The arrangement is therefore such that the inner sleeve member 1 is provided as a tapered wedge means which has some natural frictional contact with the surface of the elongate pipe upon which it is placed i.e. frictional interface (a-b) in the drawings.
The inner sleeve member 1 is preferably formed of a slightly pliable plastics material having some natural resilience and includes at least one and preferably a plurality of elongate slots or recesses 2 extending through the sleeve from each end thereof for a substantial part of but not the complete length of said inner sleeve. The slots or recesses 2, together with the pliant and resilient nature of the plastics material, enable the inner sleeve member to be compressed between the less pliable pipe and the connector body housing to provide a firm frictional engagement and fluid tight fit between the elongate pipe and the connector (in a manner to be described).
In one possible embodiment where the connector is to be used as a plumbing fitting and the pipe is a polyethylene pipe, the inner sleeve may be formed of acetal. Alternative materials include nylon, possibly glass-reinforced nylon.
The materials to be used, and the possible working of the inner surface of the inner sleeve member has an effect upon the coefficient of friction of the inner interface (a-b) shown in FIG. 1. It is considered to be an important principle of the invention that the ratio of the co-efficient of friction (or the frictional resistance to movement) between the inner sleeve and the connector body i.e. the outer interface (b'-c) in FIG. 1 should be significantly less than the co-efficient of friction (or the frictional resistance to movement) between the pipe and the inner surface of the inner sleeve (i.e. the inner interface (a-b) in FIG. 1). This arrangement is necessary to ensure that when the pipe is to be engaged in the connector movement will occur between the inner sleeve and the connector body (i.e. the outer interface) before there is any movement between the inner interfaces. This order of movement provides the initial collet engagement to ensure a proper connection of the pipe in the connector.
The increased frictional co-efficient of friction or frictional resistance on the inner interface (a-b) in FIG. I is achieved by one or more of the following methods:
(a) Providing the plastics inner sleeve member in a slightly lesser diameter than the outside diameter of the elongate pipe member so that the plastics sleeve member when fitted over has a certain natural pretension on the elongate pipe member; and/or
(b) Providing an upstanding ridge 7 of continuous length about the inner surface of the inner sleeve, which ridge member is (in cross section) shaped as a tooth; and
(c) (Alternatively) by providing a worked or "roughened" inner surface on the inner sleeve. (This is however a less preferred alternative).
In all preferred embodiments of the invention, the diameter of the bore of the inner sleeve will be either less than or substantially correspond to the outside diameter of the pipe upon which it is to be fitted. This means that when the pipe is pushed into the inner sleeve, there will be a natural frictional contact between the surface of the pipe and the inner surface of the inner sleeve. It will be appreciated that where the diameter of the inner sleeve is less than the diameter of the pipe, the inner sleeve will be expanded so that the friction is increased by the natural pre-tension of the inner sleeve in this position. In all embodiments, the tapered bore of the connector body will be sufficient to allow for this expansion of the inner sleeve.
In preferred embodiments of the invention a continuous tooth 3 is also provided on the inner surface of the sleeve member about the circumference of the inner surface and preferably adjacent to the rear end 9 of the inner sleeve. The tooth member could, however, alternatively be provided adjacent to the front end of the inner sleeve. This tooth member 3 may preferrably be a tooth with a substantially triangular shape (in cross-section) approximating a right angle triangle shape. This provides that the pipe when inserted into the inner sleeve will slide over the tooth 3 from the front end of the inner sleeve tooth member during insertion. However, when the pipe is pulled back, the leading edge 3a of the tooth member will tend to be depressed into the surface of the pipe or tube member. This tooth member accordingly has the effect of frictionally engaging the pipe in the inner sleeve to increase the frictional resistance of the inner interface (a-b).
In many of the proposed uses of the connector it is necessary to ensure that there is a fluid-tight seal between the outside of the pipe, and the inner sleeve (a-b) and between the inner and outer sleeve (b-c). For this reason the recesses or slots 2 do not pass completely along the length of the inner sleeve member 1. In many applications it may be that the invention as described will be sufficient to provide a frictional fit and thus a fluid-tight connection between the outside of the pipe and the inner sleeve member. However, it is also considered advantageous in preferred embodiments to provide a substantially serpentine-like ridge member 7, being a ridge or a substantially triangular cross-section encircling in a continuous ring or band about the inner surface (b) of the inner sleeve. The ridge is adapted to engage and/or penetrate the surface of the pipe about which it is fitted, to provide a fluid-tight connection. This ridge is in preferred embodiments also of a substantially trangular shape (in cross-section) to provide the same function as tooth 3, and to additionally assist in the sealing of the inner interface. It is possible that a similar ridge 17 may be provided on the outer face of the sleeve to assist the sealing ability of the outer interface.
If the pipe is a relatively soft rubber or plastics pipe, then in preferred embodiments a metal or hard plastic sleeve will be inserted into the end of the pipe before it is inserted into the connector. This will provide sufficient strength to support the shape of the pipe to enable the ridge member 7 to engage and or penetrate the surface of the pipe.
The connector will in preferred embodiments be formed to be assembled with (or connected to) other connectors and fittings generally indicated by arrow 30. In particular, the connector body having tapered ends 10 will preferably be comprised of a high strength plastics material, such as nylon or acetal. The material which is used will depend upon the type of connector which is to be provided. However, it will be important that the plastics material of which the body of the connector is comprised is sufficiently rigid to operate in conjunction with the inner sleeve of the connector, and sufficiently durable material for continuous long term use.
The connector body will generally be assembled with at least one other fitting to provide the connector 30. In the example shown in the drawings, the connector body is provided as a part of a connector in the form of a `T` junction including two fittings for a pipe member, and a third fitting adapted to receive a pipe and operating as an automatic shut-off valve of a type suitable for an irrigation system. This however is only one possible example of the range of uses of the connector herein described.
The inner surface (c) of lock tapered end 10 of the; connector body is provided with a taper substantially corresponding to the outer surface (b*) of the frusto-conical inner sleeve 1. In preferred embodiments the inner sleeve is adapted to be retained in the connector body between its opening 11 and inner abutment 12. This ridge could of course be part of an adjacent connector body or fitting such as the inner end of a threaded or push-fitted connector body or attachment. This arrangement provides that the inner sleeve 1 is restrained in its movement along the inner surface (c) of the connector body. The inner sleeve 1 is unable to be withdrawn through the opening 11 because of the taper of the inner surface (c) of the connector body or (optionally) by providing an inwardly depending flange about the opening. Furthermore, the inner sleeve 1 cannot be forced into the connector body beyond abutment 12 since the inner end 9 of the sleeve will abut against the inner abutment 12.
The arrangement of the invention is such that the inner sleeve 1 is inserted into the opening 11 of the connector body tapered end 10. The pipe 20 is then pushed through the bore (x-x) of the inner sleeve 1 to the position shown in FIG. 1 of the drawing, slightly expanding the inner sleeve. This frictional fit of the pipe into the inner sleeve 1 will force the inner sleeve into the connector body so that the inner end 9 of the inner sleeve abuts against the inner abutment 12. Once the pipe is completely inserted into the connector body it will be positioned as shown in FIG. 1 of the drawing. The arrangement is then such that there is a good frictional fit in the interface (a-b) between the surface of the pipe (a) and the inner surface of the inner sleeve (b). In preferred embodiments, this frictional fit is improved by the upstanding serpentine like ridge 7 on the inner surface of the sleeve and (optionally) the tooth member 3 both of which are shaped to be depressed into the surface of the pipe member when an attempt is made to withdraw the pipe from the connector in the manner to be described.
To complete the engagement of the pipe in the connector body, the pipe is pulled in the direction indicated by arrow (y). As suggested, this will cause the upstanding tooth portion 7 and optional tooth 3 to depress into the pipe member and complete the frictional engagement of the inner interface (a)-(b) between the pipe and the inner sleeve. Thereafter, movement of the pipe will cause the inner sleeve to slide outwardly along the inner surface (c) of the connector body tapered end 10. With this movement, a frictional fit will be completed between the outer interfaces (b'-c). A fluid-tight fitting is then completed between the inner and outer interfaces and the pipe will be securely engaged in the connector. The strength of the frictional fit between the inner interface, any longitudinal loads on the pipe, and the natural water pressure in the connector will maintain the connection of the pipe within the connector since all of these forces will tend to increase the forced movement of the inner sleeve member 1 outwardly along the inner surface (c) of the connector body tapered end, thus increasing the frictional engagement of both interfaces. It will be appreciated that subsequent creep of the pipe within the fitting will merely increase the strength of the connection of the pipe within the connector. This means, that the type of creep which has been known to cause problems with other types of fluid connectors is not a problem with the present invention.
In further preferred embodiments upstanding serpentine like ridge 17 is also provided about the outside surface of the inner sleeve. These ridges on both surfaces of the inner sleeve provide for an increased compressive loading on the narrow area of contact to thereby increase the sealing capabilities of the inner sleeve on both of its interfaces.
In one possible alternative the connector includes a sealing ring 60 be provided between the pipe, the body of the fitting, or the connector body 10, and the inner edge 9 of the sleeve 1. This may be advantageous where (because of materials) a supplement is required to the sealing ridges 7 and 17.
It will be appreciated that the gap between the rear of the sealing ring and the housing of the connector will be of sufficient length to enable the movement of the sleeve member for the positioning of the sealing ring. If excessive pressure is applied to the connector, the sealing ring 60 will be forced along the frustoconical inner surface of the connector body to form a seal between the pipe, the inner end of the sleeve member and the inner surface of the connector. This accordingly acts in addition to the seal provided by the sleeve member itself.
In preferred embodiments the invention provides for the pipe to be removably engageable in the connector body tapered end 10. In this embodiment, the invention includes lug members 14 which are provided as inwardly depending elongate lugs extending near the opening 11 from the connector body. These lug members 14 are adapted to fit into any of the elongate recesses or slots 2 in the inner sleeve. By way of explanation only, a dotted illustration of one such lug member 14 is shown in FIG. 2 of the drawing so that its dimensions can be appreciated. It will be seen that the lug member 14 is adapted to slidably fit within recess 2 of the inner sleeve member.
In this embodiment, the lug member 14 will slide into one of the recesses 2 when the pipe and the inner sleeve member are forced in the direction indicated by arrow (y). However, if the pipe is then to be withdrawn from the connector it is necessary to push the pipe into the connector in the direction indicated by arrow (z). The lug 14 will then slide out of recess 2. Rotation of the pipe then causes the rotation of the inner sleeve 1. In turn, the edge 14(a) of the lug is adapted to abut against the outer edge, or lip, 2(a) of the inner sleeve member. It will be appreciated that the inner sleeve will thus be contained in the connector body between the ridge 12 and the edge 14(a) of the lug member and is thereby prevented from movement in either direction within the connector body. When the inner sleeve member is so positioned, it is possible to withdraw the pipe 20 in the direction indicated by arrow (y) out of the connector body as the inner sleeve can no longer wedge between the pipe and the outer sleeve. As and when required, the pipe (or any other pipe) may then be reinserted into the connector to the position shown in FIG. 1 and rotated so that the inner sleeve is itself rotated. By this movement lug member 14 is realigned with the recess 2 or any of the other recesses in the inner sleeve. The inner sleeve, will have engaged the pipe member and the pipe is moved in direction (y) to complete the reconnection.
It will also be appreciated that the method of locking the inner sleeve in position to enable withdrawal of the pipe from the connector could involve several possible alternatives. In particular, a lug member could be integrally formed on either the inner sleeve or the connector body. This lug member could then fit into an appropriate recess on either the front mid-portion or rear of the inner sleeve or the connector body. One possible example of this is shown in FIG. 2 (in dotted line) including lug 51 to fit into recess 52 in the rear (or middle of) the connector body/inner sleeve. In this embodiment lug 51 could be disengaged from recess 52 and slide in recess 2 to engage the pipe in the connector.
In one possible embodiment the provision of the lug member 14 adapted to fit within the recess 2 in the inner sleeve provides a visual indication as to whether the connector is in a locked or unlocked position.
In preferred embodiments a secondary recess 2b will be provided adjacent each recess 2 which opens towards the front end of the inner sleeve member. In preferred embodiments, a plurality of lug members 14 will be provided in the connector body to correspond to the number of secondary recesses 2b. The lug members will slide within the primary recesses 2 during insertion and engagement of the pipe within the connector. However, as described in the preceding paragraph, when the pipe is to be removed from the connector, it is pushed into the connector in the direction indicated by arrow (z). The lug member 14 will then slide out of primary recess 2, and rotation of the pipe member causes rotation of the inner sleeve member 1. In turn, each lug 14 will by this movement be positioned in a secondary recess 2b. The inner sleeve will then be contained in the connector and prevented from movement in either direction so that the pipe can be withdrawn from the connector.
By this invention, a pipe may be readily engaged and disengaged from a connector without the use of tools and without any working of the end of the pipe member. Furthermore, because of the longitudinal load exerted by the water pressure on the pipe in the direction indicated by arrow (y), the inner sleeve is inclined towards a tighter frictional fit with the tapered inner surface (c) of the connector body.
The arrangement of the substantially complementary tapered surfaces between the inner sleeve and the connector body provides for a tapered collet type self locking arrangement so that the larger the pressure or longitudinal load exerted by the pipe, then the tighter the grip of the connector on the pipe. This locking arrangement is therefore effective to always counteract and eliminate creep of the pipe, or any tendency towards disengagement of the pipe from the connector. Furthermore, this grip applies only in one direction so that the pipe may be readily unlocked from the connector by movement in direction (z) opposite to the longitudinal loading direction (y).
In one preferred use of the invention, the connector member 30 will be provided as a T junction into which pipe members 20 and 21 may be inserted and which has an automatic shut off valve generally indicated by arrow 40. This type of system has one use in connection with irrigation systems, where it is necessary to removably engage a branch fitting into a main supply pipe, being the pipe 20-21. In this embodiment, a plunger member extends within the inner sleeve by which the pipe 22 is adapted upon insertion into the connection to operate an automatic shut off valve. In the embodiment disclosed, the plunger head 42 is adapted to engage the leading inner edge of the pipe 22. The plunger head 42 is connected to a valve head 44 by stem 47. The arrangement is such that as the pipe 22 is inserted into the inner sleeve 41 the end of the pipe abuts against the plunger head 42 to open head 44 from valve seat 45. The pipe 22 is then engaged with the inner sleeve in the connector body in the manner previously described to complete the connection in the connector. Upon removal of the pipe 22 the compressed spring 46 is again extended and is adapted to reclose the valve head 44 on valve seat 45. The arrangement as shown in FIG. 1 of the drawings depicts the pipe 22 in position immediately prior to engagement in the connector, and opening of the valve. It will be appreciated that alternative embodiments for automatic shut off valves, conventional fluid fittings or any other type of connector or fitting or coupling may be provided in conjunction with the connector as described herein.
For example, sprinkler heads, further standard connectors, four way junctions, hose couplings or snap couplings, or any other type of fitting or apparatus may be provided integrally formed with the connector 30 as described according to this invention depending upon the purpose desired.
The invention therefore provides a connector which is particularly suitable for use in relation to connecting pipes or tubes of generally round cross section whether or not the pipe or tube has a smooth and/or plastic surface. The invention provides for fluid-tight grip of the connector parts on the pipe or tube and in preferred embodiments provides for removable engagement of the pipe within the connector.
Finally, it will be appreciated that the invention has been described by way of example only and that modifications, alterations and additions may be made to the invention without departing from the scope thereof. | A connector for and a method of connecting pipe members for a variety of purposes including (but not limited to) plumbing, hydraulics, pneumatics and medical purposes. Wherein the connector which can be used in conjunction with other fittings, has a connector body with an opening to receive a pipe and a tapered internal bore in the opening to receive a substantially coaxial inner sleeve adapted to engage the surface of the pipe in the connector. After insertion, the pipe is then moved in an opposite direction to the direction of insertion and the inner sleeve is adapted to slide wherein internal bore to wedge into frictional engagement and connection with the outer surface of the pipe and the tapered surface of the internal bore so that when the pipe is sealably engaged within the connector the pipe can be disengaged from the connector by a reverse operation. The connector has the advantage that a pipe may be sealably engaged in the connector without the necessity to work the pipe, in a connector comprised of two components manufactured of plastic materials. The inner sleeve may have sealing ridges to increase the sealing capabilities of the connector. | 5 |
The invention relates to an electromedical implant for intracardial coronary therapy, having the features recited in the classifying portion of claim 1 .
BACKGROUND OF THE ART
The electrotherapeutic treatment of cardiac arrhythmias by means of implantable cardiac pacemakers has become established as a powerful, versatile, comparatively low-risk and reliable form of treatment. Electromedical implants of that kind include numerous functional individual components which are necessary for long-lasting therapeutic treatment of the heart, which is suited to the physiological factors involved and which is as trouble-free as possible. Those components can be systematically divided into components which are disposed in a housing of the implant and components which are arranged outside the housing. The latter involve for example sensors for physiological parameters and the electrodes, by way of which a pacemaker pulse is transmitted to the atrium or ventricle myocardium. The implant housing in contrast accommodates functional components such as a battery, a circuit, telemetric means and the like.
The electromedical implant is to have a service life which is as long as possible and good compatibility. Under some circumstances those two aspects can be in conflict. Thus on the one hand the implant should be of the minimum possible structural size so that it is not perceived as troublesome by the patient after the implantation operation or indeed give rise to unwanted physiological reactions. On the other hand the battery for a long service life must be of the maximum possible capacity, which in a practical context means that the battery generally fills up markedly more than 80% of the internal space of the housing. There is therefore always the need for making the optimum possible use of the available space.
As intracardial therapy in the meantime has developed into a standard procedure which has proved its worth worldwide millions of times, it is appropriate for cost reasons to automate the process for production of the implants. The construction of current electromedical implants can in that respect be described in simplified terms as follows. All functional components such as the battery, the circuit, the telemetry unit or the like are disposed in mutually juxtaposed relationship in the implant housing. The implant housing itself is generally of a flat, elongate contour with rounded-off edges and is generally formed from two half-shell portions with a kind of snap-action mechanism comprising interengaging edges. Then, in the opened condition, the conventional arrangement with functional components mounted in mutually juxtaposed relationship on an inner base surface of the half-shell portions can be clearly seen. It will be noted that such an arrangement suffers from the disadvantage that, in assembly of the individual components, it is necessary to operate on a plurality of production axes. That makes automation more difficult and leads to increased costs. In addition the available space cannot be put to optimum use, for example because generally an expensive and complicated electrical contacting means for contacting the power-consuming components with the battery additionally has to be fitted.
U.S. Pat. No. 6,026,325 to Weinberg et al. discloses an electromedical implant having a circuit whose electronic components are arranged in stacked relationship. The individual electronic components of such a circuit are disposed perpendicularly to the heightwise extent of the implant housing on parallel substrate planes. The circuit and the further functional components such as a battery and capacitors are mounted in conventional manner in mutually juxtaposed relationship on the base surface of the implant housing.
U.S. Pat. No. 6,251,124 to Youker et al. describes a cardiac pacemaker in which a plurality of capacitors is arranged in a plurality of substrate planes in the housing. All further functional components—disposed beside the capacitors—are arranged on the inner base surface of the housing.
Furthermore, WO 99/06107 discloses a cardiac pacemaker whose circuit includes a memory unit comprising memory chips stacked in mutually superposed relationship. That is intended to minimize the structural space required for an electrical connection between the individual memory chips. As in the above-mentioned specifications, the stacked arrangement is limited to selected partial structures of the functional components of the implant.
SUMMARY OF THE INVENTION
An aspect of the present invention is to make better use of the structural space available in the housing and to optimize the construction of the implant from the point of view of a production process which can be automated and is as simple as possible.
The invention emanates from an electromedical implant for intracardial coronary therapy comprising an implant housing and functional components of the implant disposed in said housing wherein the functional components comprise a circuit and a battery and wherein the battery has a flat side, an underside and a peripherally extending narrow side and the battery is arranged with its underside on an inner base surface of the implant housing and the circuit is disposed adjacent to a flat side of the battery.
In a first advantageous configuration of the invention the circuit includes a component carrier with fitment set, on the top side of which the individual electronic components of the circuit are mounted. An underside of the component carrier and thus the circuit is arranged adjacent to the flat side of the battery. Advantageously, the circuit is fixedly mounted to the flat side of the battery, for example by means of known adhesive processes. In the depicted arrangement accordingly the flat circuits which are embodied on conventional component carriers are fixed directly on the battery, in which respect a mounting direction of battery and circuit is retained. It will be self-evident that an electrical connection to the voltage source between the battery and the circuit only needs to be of small dimensions and, in contrast to conventional electrical connections, does not have to be made by way of a joining procedure but can also be implemented in a direct plug-in configuration. Accordingly a short discrete join is possible, without discrete elements.
During discharge of the battery a slight increase in the volume of the battery occurs, as a consequence of the underlying electrochemical reaction. That discharge-induced swelling of the battery must be compensated when there is a fixed connection between the battery and the circuit as otherwise there is a threat of mechanical damage to the circuit. In a further advantageous embodiment of the invention for that purpose disposed between the flat side of the battery and the underside of the circuit are structures with which it is possible to compensate for the discharge-induced swelling of the battery. Those structures include free spaces between the battery and the circuit or joining elements which permit a relative movement of the circuit with respect to the battery.
In a further advantageous configuration of the invention the underside of the component carrier and thus the circuit is arranged adjacent to an inward side of the implant housing. The electronic components of the circuit then face in the direction of the battery. If the inward side of the half-shell portion is suitably structured the half-shell portion can function at the same time as the component carrier for the electronic components. At any event, it is possible to forego the structures for compensation of the discharge-induced swelling of the battery. In production of the implant, in a common production step, the circuit is introduced into the implant and the housing closed.
It is further advantageous if there is provided a mounting element which accommodates the circuit. The relative orientation of the fitment set or components of the circuit with respect to the battery can then be adapted to the respective requirements involved. Accordingly, the electronic components can face either in the direction of the battery or in the direction of the housing. The mounting element can be introduced into the implant without a mechanical join to the battery or only at the periphery thereof so that the mechanical stresses which occur as a consequence of the discharge-induced variation in volume cannot be diverted to the circuit.
In addition, it has proven to be advantageous if the battery does not fill all the internal base surface of the implant housing. The remaining free spaces are used in such a way that, after mounting of the constituent parts, electronic components of a great structural height project into those free spaces. The aim here is to ensure the best possible utilization of space with a small overall structural height without having to make cuts in terms of functionality.
The battery which is suitable for such single-axis construction of the electromedical implant is to be as flat as possible in terms of its contour, as the circuit and optionally further functional component parts are to be arranged adjacent to its flat side. In this connection, the use of electrochemical energy storage systems based on lithium and manganese dioxide has proven to be particularly advantageous. The equipment components of the circuit are preferably also of the minimum possible structural height.
A further preferred configuration of the invention provides that the adjacent flat sides of the battery and the circuit have a mutually matched heightwise profile. The aim here is to minimize the overall height of the two component parts which are stacked one upon the other. Thus, in regions in which electronic components of the circuit of a relatively great structural height are disposed, the battery is of a smaller structural height than in the other regions. If further or all functional component parts disposed in the implant housing are stacked one upon the other, then the above-described matching in respect of the heightwise profile can also be applied to those component parts.
A further preferred embodiment of the invention is one in which the implant housing comprises two half-shell portions and one thereof is at the same time a constituent part of the battery housing. In that way it is possible to eliminate a housing half-shell portion.
In a further development of the last-mentioned concept of the invention, both half-shell portions at the same time also form the battery housing. In this case the circuit and all further functional component parts of the implant must hermetically sealed with respect to the electrolyte of the battery. It is possible in that way to eliminate two half-shell portions and the utilization of structural space in the arrangement can be further optimized.
Further preferred embodiments of the invention are set forth by the other features recited in the appendant claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in greater detail hereinafter in embodiments with reference to drawings in which:
FIGS. 1 a through 1 d are diagrammatic plan and side views of batteries for an electromedical implant,
FIGS. 2 a and 2 b are two diagrammatic plan views onto a half-shell portion of an implant housing with a battery arranged on the internal base surface,
FIG. 3 is a sectional view of a circuit arrangement in the implant in accordance with a first variant,
FIG. 4 is a sectional view of a circuit arrangement in the implant in accordance with a second variant,
FIGS. 5 a and 5 b show two sectional views of alternative arrangements of the circuit with a mounting element,
FIG. 6 shows a sectional view of a further alternative circuit arrangement in the implant with a free space in the region of the implant housing,
FIGS. 7 a and 7 b show two sectional views of alternative arrangements with a heightwise profile which is matched as between the battery and the circuit,
FIGS. 8 a through 8 f show perspective detail views of six alternative lead-through ducts for producing an electrical connection,
FIGS. 9 a and 9 b show a partly sectional view and a detail view on an enlarged scale through the battery, circuit and a structure for compensating for discharge-induced variations in volume,
FIGS. 10 a and 10 b show perspective side views of two joining elements for compensating for discharge-induced variations in volume in the open and closed form,
FIG. 11 is a sectional view of an arrangement in which the battery housing replaces a half-shell portion of the implant housing,
FIG. 12 shows a sectional view of an implant housing in which the battery housing replaces both half-shell portions of the implant housing, and
FIG. 13 shows an illustration of the single-axis production process of an electromedical implant.
DETAILED DESCRIPTION OF THE INVENTION
The mode of operation and the area of use of electromedical implants are generally known. By virtue of an appropriate selection of functional components, all stimulation and diagnostic functions which are necessary for each individual case can be integrated into such an electromedical implant. It will be noted that in the present case only the arrangement according to the invention of the functional components in the implant housing is of significance. Therefore only the structural features, which are necessary to the invention, of the individual functional components and their relative position with respect to each other are described in the examples hereinafter.
FIGS. 1 a through 1 d are greatly simplified side and plan views showing the contours of two alternative embodiments of a battery 10 . In this example the battery 10 is of an oval basic shape. While having the same base surface, that is to say the same lengthwise and widthwise dimensions, the two batteries 10 differ only in respect of their heightwise profile. The battery 10 illustrated in FIGS. 1 a and 1 b has a narrow side 10 . 1 which extends therearound at a constant height as well as a flat side 10 . 2 and an underside 10 . 3 with a flat contour, thus affording a homogenous heightwise profile. In contrast the battery 10 shown in FIGS. 1 c and 1 d involves a heightwise profile in which a first portion 12 of the narrow side 10 . 1 and the flat side 10 . 2 is of a smaller height than a second portion 14 . The conditions under which the use of one or other alternative embodiment of the battery 10 is appropriate will be discussed in greater detail hereinafter.
The battery itself is in particular an electrochemical cell based on lithium/manganese oxide elements. Batteries 10 of that kind are distinguished by their particularly high energy density and also their flexible design so that they are suitable as a flat unit or sandwich unit. FIGS. 2 a and 2 b show the relative position of two batteries 10 involving different base shapes in a half-shell portion 16 of an implant housing 18 . As will be clearly apparent the battery 10 in each case does not take up an entire internal base surface 18 . 1 of the half-shell portion 16 . Rather, free spaces 20 of differing sizes remain, and the use thereof will also be discussed in greater detail hereinafter.
A highly diagrammatic sectional view in FIG. 3 shows an electromedical implant including two functional component parts, namely the battery 10 and a circuit 22 . The circuit 22 includes all electronic components 24 which are necessary for the functional logic of the implant and which are arranged in the form of an equipment set on a component carrier 26 with a circuit board. The electronic components 24 are preferably SMT-units which are produced in per se known manner from the point of view of a structural height which is as small as possible. An electrical connection between the battery 10 and the circuit 22 can be produced by the lead-through duct 28 indicated here. The circuit 22 is now fitted with its underside 22 . 1 onto the flat side 10 . 2 of the battery 10 , in such a way that electrical contact is produced and the circuit 22 is arranged in adjacent relationship to the flat side 10 . 2 of the battery 10 —possibly being fixed by adhesive means. Then the implant housing 18 is closed by a second half-shell portion 30 being put onto the first half-shell portion 16 . The two half-shell portions 16 , 30 are for that purpose preferably in the form of snap-action shell portions with mutually interengaging edges.
In an arrangement which is an alternative to FIG. 3 the circuit 22 is arranged with its underside 22 . 1 in adjacent relationship to an inward side 30 . 1 of the second half-shell portion 30 ( FIG. 4 ). The equipment set of the circuit 22 then faces in the direction of the battery 10 . An electrical connection is in turn made by way of the lead-through duct 28 when the two half-shell portions 16 , 30 of the implant housing 18 are brought together. The inward side 30 . 1 of the second half-shell portion 30 can possibly be suitably structured to carry the electronic components 24 of the circuit 22 . Thus for example a component carrier can be introduced directly into the inward side 30 . 1 of the half-shell portion 30 .
The following is to be noted in regard to the dimensioning of the individual constituent parts of the variants in FIGS. 3 and 4 : an overall thickness of the battery 10 in all of the regions in opposite relationship to the circuit 22 is preferably <3.9 mm, a component height of all electronic components 24 is preferably <2 mm and the thickness of the component carrier 26 is <0.25 mm. Finally the battery 10 and the circuit 22 preferably extend over >85%, in particular over >90%, particularly preferably over >95%, of the overall housing volume. The circuit 22 preferably extends over >80% in particular over >90% and particularly preferably over >95% of the flat side of the battery 10 .
FIGS. 5 a and 5 b show the circuit 22 and the battery 10 in a stacked arrangement which is in principle the same, as in FIGS. 3 and 4 . However, the circuit 22 does not bear directly against the battery 10 or the half-shell portion 30 but is accommodated by a mounting element 32 . The mounting element 32 has structures which are suitable for that purpose and in which the component carrier 26 can be clamped. The specific design configuration of the structures must be adapted to the respective structural aspects involved. Measures of that nature are adequately known to the man skilled in the art so that they will not be discussed in greater detail here. After accommodating the circuit 22 the mounting element 32 is arranged in adjacent relationship with the battery 10 , in which case the component mounting side thereof faces selectively in the direction of the half-shell portion 30 ( FIG. 5 a ) or in the direction of the battery 10 ( FIG. 5 b ). Such a mounting element 32 affords the advantage that stresses which can occur in the region of the battery 10 as a consequence of variations in volume are not transmitted directly to the circuit 22 and there result in mechanical damage. In addition, this arrangement affords options in terms of joining technologies which are suited to single-axis mounting operations.
If the battery 10 does not occupy the entire base surface of the half-shell portion 16 of the implant housing 18 and thus free spaces 20 remain, it is possible to embody the alternative arrangement of the component parts of the implant, as is diagrammatically shown in FIG. 6 . In accordance with that arrangement electronic components 24 of particularly great structural height are placed on the circuit 22 in such a way that they project into the free spaces 20 , after the two component parts have been assembled.
With a differing structural height in respect of the electronic components 24 of the circuit 22 , two further alternative possible design options present themselves for such a single-axis arrangement of the component parts ( FIGS. 7 a and 7 b ). Both alternatives are based on a battery 10 with heightwise profile as has already been described with reference to FIG. 1 b . As shown in FIG. 7 a the contour of the circuit 22 including the component carrier 26 is adapted to the heightwise profile of the battery 10 . The electronic components 24 of the greatest structural height are obviously disposed in the region 12 of the battery 10 which involves the smallest heightwise extent ( FIG. 7 a ). Alternatively, as shown in FIG. 7 b , a circuit 22 with a flat component carrier 26 is arranged in adjacent relationship with the half-shell portion 30 , more specifically in such a way that the highest electronic components 24 , after the mounting procedure, are arranged above the region 12 of the battery 10 which is of the smallest structural height.
FIGS. 8 a through 8 f show a total of six alternative embodiments of a lead-through duct 28 which can be used to produce the electrical connection between the battery 10 and the circuit 22 . The ducts 28 can be soldered on during an SMT-mounting process as constituent parts of the circuit 22 . It is necessary in each individual case to decide at what locations ultimately a soldering operation is to be effected or what orientation individual elements of the duct 28 have relative to the position of the component parts to be connected therewith. It will be noted that in principle the single-axis construction of the functional component parts permits a marked simplification in the electrical circuitry as only small distances have be bridged. That affords savings of material and gains in terms of structural space. The ducts 28 which are set forth by way of example are electrically connected to the circuit 22 by way of nail heads ( FIG. 8 a ), adaptors ( FIGS. 8 b and 8 c ), bent pins ( FIGS. 8 d ), flattened pins ( 8 e ) or conventional solder joins ( 8 f ). In accordance with the variants in FIGS. 8 b and 8 c , it is possible to forego bonding joining processes for producing the electrical connection. It will be appreciated that for that purpose it is possible to provide electrical plug elements of varying configurations, which engage into each other when the implant is assembled. Here too the description will not go into these aspects in greater depth as such plug elements are sufficiently known to the man skilled in the art and have to be adapted to the respective functional and structural requirements involved, from one case to another.
When the circuit 22 is fixedly connected to the battery 10 , measures must be taken to prevent damage to the circuit 22 as a consequence of a gradual variation in volume of the battery 10 . Such a variation in volume results from the electrochemical reactions which take place during the discharge process in the battery 10 . To compensate for the discharge-induced swelling of the battery 10 , special structures 34 are arranged between the flat side 10 . 2 of the battery 10 and the underside 22 . 1 of the circuit 22 . FIGS. 9 a and 9 b —in part as a detail view on an enlarged scale—show a view in section through the battery 10 and the circuit 22 in the region of the structures 34 . They are in the form of free spaces between the battery 10 and the circuit 22 , into which parts of the battery 10 can penetrate in the discharge process and the increase in volume which is related thereto. Those structures 34 can be an integral constituent part of the component carrier 26 , for example etched copper structures, and they can be inexpensively produced using standard procedures in production of the component carrier.
As an alternative thereto, it is also possible to provide between the battery 10 and the circuit 22 joining elements 36 as are shown in FIGS. 10 a and 10 b prior to and after mounting of the component parts. The joining elements 36 involve a male and a female contour which, when the component parts are stacked in mutually superposed relationship, engage one into each other and hold the component parts at a defined spacing. It will be appreciated that it is possible here to have recourse to a large number of alternative embodiments of the joining elements 36 , as are sufficiently known from the state of the art. The only essential criterion in regard to the joining elements 36 is that they permit a relative movement of the two component parts with respect to each other. For automation reasons the illustration snap-action connection particularly presents itself in that respect.
FIG. 11 diagrammatically shows a further alternative arrangement with a single-axis component construction. In its broad outlines it corresponds to the arrangement of the circuit 22 and the battery 10 , which has already been described with reference to FIG. 3 . It will be noted that in this case a battery housing 38 is used at the same time to form the lower half-shell portion of the implant housing 18 . For that reason, at least in that region, the battery housing 38 is made from a biocompatible material, in particular titanium. In that way it is possible to forego one of the two half-shell portions of the implant housing 18 and the resulting structural space can be used for the functional component parts. In addition, a production step is eliminated from the production process, namely the step of placing the battery 10 in one of the half-shell portions of the implant housing 18 . When turning over a seam between the battery housing 38 and the half-shell portion 30 , if necessary (for example because of a thermal loading in the joining procedure), it is possible to implement subsequent filling of the battery 10 with electrolyte or activation in some other manner by way of an additional filling opening, whereby it is possible to determine the moment in time of the commencement of energy-consuming operation of the implant.
In an extension of the last embodiment FIG. 12 is a diagrammatic sectional view of an electromedical implant in which the implant housing 18 is completely replaced by the battery housing 38 . All functional component part—in this case the illustrated circuit 22 with its electronic components 24 —are disposed within the battery 10 and to protect them have to be hermetically sealed in relation to the electrolyte of the battery 10 . Sealing of the circuit 22 can be effected for example by a dipping process with inert resins/dipping lacquers. The dried resins/dipping lacquers form a protective layer through which the electrolyte cannot pass or which it cannot attack. It is possible in that way to eliminate two housing half-shell portions.
FIG. 13 is intended to illustrate once again by way of example the single-axis mounting of the functional component parts during manufacture of an implant (as indicated by an arrow). Firstly the battery 10 , then the circuit 22 and finally the half-shell portion 30 are respectively fitted into or onto the half-shell portion 16 , in each case from the same approach direction. That substantially simplifies automation and enhances the degree of precision in terms of placement of the individual components. The arrangement and the mounting sequence may vary.
The implants produced in the above-described manner are intended to correspond in their dimensions to the dimensions of known implants. They are therefore of an overall height of between 5 and 7 mm. Of that, the metal case of the implant housing 18 including applied films for insulation and the free space for fixing of the component parts occupies between about 0.6 and 0.9 mm. In embodiments in which the battery 10 has a heightwise profile ( FIGS. 7 a and 7 b ) the thickness of the battery generally varies between 1.5 and 4.5 mm, with the remaining structural space being used for the circuit 22 .
List of references
10
battery
10.1
narrow side of the battery 10
10.2
flat side of the battery 10
10.3
underside of the battery 10
12
portion of low structural height
14
portion of larger structural height
16
lower half-shell portion
18
implant housing
18.1
internal base surface
20
free space
22
circuit
22.1
underside of the circuit 22
24
electronic components
26
component carrier
28
lead-through duct
30
upper half-shell portion
30.1
inward side of the upper half-shell portion 30
32
mounting element
34
structures for compensation of discharge-induced swelling
36
joining element
38
battery housing | The invention concerns an electromedical implant for intracardial coronary therapy comprising an implant housing in which functional component parts of the implant, namely a circuit, a battery and the like, are disposed. It is characterized in that the battery ( 10 ) has a flat side ( 10.2 ), an underside ( 10.3 ) and a peripherally extending narrow side ( 10.1 ) and the battery ( 10 ) is arranged with its underside ( 10.3 ) on an internal base surface ( 18.1 ) of the implant housing ( 18 ) and the circuit ( 22 ) is arranged in adjacent relationship with a flat side ( 10.2 ) of the battery ( 10 ). | 0 |
FIELD OF THE INVENTION
The present invention relates to a suspension mechanism for an acoustic apparatus, for example, a disc player or tape deck constructed for use in a vehicle such as an automobile.
BACKGROUND OF THE INVENTION
In order to explain the background of the invention, reference will be made to FIG. 10:
In FIG. 10, the reference numeral 1 designates a player comprising a mechanism portion for reproduction 2 and a container or housing 12 for containing the mechanism portion 2. The container 12 is constituted by a chassis 5 for supporting the mechanism portion 2, a panel 4 on each end, and an upper cover 6. The numeral 7 designates a viscous and elastic member having a pillar shape and made of a viscous and elastic body such as rubber. The upper and the lower ends of the viscous-elastic member 7 are fixed to the frame 3 of the mechanism portion 2 and the chassis 5, respectively, so that elastic member 7 supports the weight of the mechanism portion 2 and absorbs the vibrations applied to the mechanism portion 2.
In this prior art acoustic apparatus, the viscous-elastic member 7 constitutes a suspension mechanism for supporting the weight of the mechanism portion 2 and absorbing the vibrations applied to the mechanism portion 2. However, the viscous-elastic member 7 has been stressed by the weight of the mechanism portion 2 before receiving any external forces such as vibrations, and therefore it cannot exhibit a sufficient damping effect when it receives stresses caused by the vibrations of an automobile. Furthermore, this elastic member 7 deteriorates with the passage of time under special circumstances, such as where there is great temperature variation as in an automobile.
SUMMARY OF THE INVENTION
The present invention is directed to solving the problems pointed out above with respect to the prior art device, and has for its object to provide an acoustic apparatus capable of absorbing the stresses caused by the movement of the vehicle, and capable of protecting the reproduction mechanism portion effectively without a deterioration of the suspension function with the passage of time even under special circumstances such as those present in a vehicle.
Other objects and advantages of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific embodiment are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
According to the present invention, there is provided an acoustic apparatus which, including a reproduction mechanism portion and a container for containing the same, comprises: a suspension mechanism provided between the reproduction mechanism portion and the container; and the suspension mechanism including a first elastic element for supporting the weight of the reproduction mechanism portion, and a second elastic element for absorbing vibrations transmitted to the reproduction mechanism portion.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view showing an acoustic apparatus for use in a vehicle as a first embodiment of the present invention;
FIG. 2 is a cross sectional view on lines II--II of FIG. 1;
FIGS. 3 and 4 are cross-sectional views for exemplifying the operations of the first embodiment;
FIG. 5 is a cross-sectional view showing an acoustic apparatus for use in a vehicle as a second embodiment of the present invention;
FIG. 6 is a cross-sectional view on lines II--II of FIG. 5;
FIGS. 7 and 8 are cross-sectional views for exemplifying the operations of the second embodiment;
FIG. 9 is a cross-sectional view showing an alternative of the above embodiments;
FIG. 10 is a cross-sectional view showing a prior art acoustic apparatus for use in a vehicle.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to explain the present invention in detail, reference will be particularly made to FIGS. 1 to 4:
FIGS. 1 to 4 are cross-sectional views showing an optical or compact disc player as a first embodiment of the present invention. In the figures the same reference numerals are used to designate the same or corresponding elements as those shown in FIG. 10.
The reference numeral 9 designates a viscous and elastic member as a second elastic member provided between the reproduction mechanism portion 2 and the chassis 5, produced in a circular pillar configuration of a viscous and elastic material such as rubber. There is produced a hollow section 9a inside of the viscous-elastic member 9. There are embedded fixing posts 10a and 10b in the upper and the lower portion of the viscous and elastic member 9, respectively. The post 10a at the upper end is fixed to the reproduction mechanism portion 2, and the post 10b at the lower end is fixed to the chassis 5.
The reference numeral 8 designates a metal coil spring as a first elastic element provided surrounding the viscous-elastic member 9. The coil spring 8 and the viscous-elastic member 9 constitute a suspension mechanism 13. This suspension mechanism 13 is preferably provided in 3 or 4 locations depending upon the weight of the reproduction mechanism portion 2.
In this embodiment, the weight of the reproduction mechanism portion 2 is supported only by a coil spring 8, and virtually no stress is applied to the viscous-elastic member 9 when the vehicle is stationary (refer to FIG. 2). When a force A in a transverse direction is applied to the vehicle by the rolling of the vehicle in the forward-and-backward direction or leftward-and-rightward direction by rapid acceleration or rapid turning, for example the coil spring 8 and the viscous-elastic member 9 assume the positions shown in FIG. 3, thereby absorbing stresses in the horizontal direction.
On the other hand, when a force B in an up-and-down direction is applied to the vehicle caused by the roughness of the road, for example, as shown in FIG. 4, the coil spring 8 and the viscous-elastic member 9 assume the positions shown in the Figure, thereby absorbing stresses in the up-and-down direction.
As described above, the force applied to the player 1 is absorbed by the coil spring 8 and the viscous-elastic member 9, and the force is prevented from being transmitted to the reproduction mechanism portion 2, whereby the mechanism portion 2 is protected effectively. Meanwhile, the weight of the reproduction mechanism portion 2 scarcely acts on the viscous-elastic member 9 when the vehicle is stationary, whereby the capabilities of the suspension mechanism 13 are prevented from deteriorating with the passage of time even under special circumstances such as aboard a vehicle.
Furthermore, the viscous-elastic member 9 is surrounded by the coil spring 8 with its upper and lower end fixed, thereby enabling the regulation and positioning of the coil spring 8 without fixing it, and also utilizing the space effectively and minimizing the size of the device.
A second embodiment of the present invention will be described with reference to FIGS. 5 to 8:
FIGS. 5 to 8 are cross-sectional views showing an optical disc player as a second embodiment of the present invention. In the Figures the same reference numerals are used to designate the same or corresponding elements as those used in the first embodiment.
The reference numeral 14 designates a liquid body such as oil or grease sealed in the hollow section 9a of the viscous elastic member 9. This liquid body 14 constitutes a portion of the second elastic member.
In this second embodiment, the weight of the reproduction mechanism portion 2 is supported by only the coil spring 8 when the vehicle is stationary, and virtually no stresses are applied to the viscous-elastic member 9 (refer to FIG. 6). When a force in a transverse direction is applied to the vehicle by the rolling of the vehicle in the forward-and-backward direction or left-and-rightward direction by a rapid acceleration or rapid turning, for example, the coil spring 8, the viscous-elastic member 9, and a liquid body 14 sealed in the hollow section 9a assume the positions shown in FIG. 6, thereby absorbing stresses in the horizontal direction.
On the other hand, when a force B in an up-and-downward direction is applied to the vehicle caused by the roughness of the road, for example, as shown in FIG. 8, the coil spring 8, the viscous-elastic member 9, and the liquid body 14 sealed in the hollow section 9a assume the positions shown in FIG. 8, thereby absorbing stresses in the up-and-downward direction.
As described above, the force applied to the player 1 is absorbed by the coil spring 8, the viscous-elastic member 9, and the liquid body 14 sealed in the hollow section 9a, and the force is prevented from being transmitted to the reproduction mechanism portion 2, whereby the mechanism portion 2 is protected effectively. Meanwhile, the weight of the reproduction mechanism portion 2 scarcely acts on the viscous elastic member 9 and the liquid body sealed in the hollow section 9a in the stop state of the vehicle, whereby the capabilities of the suspension mechanism 13 are prevented from deteriorating with the passage of time even under special circumstances such as aboard a vehicle. Furthermore, the liquid body 14 also absorbs stresses which arise when a force in the up-and-downward direction or left-and-rightward direction is applied thereto, thereby suppressing the deterioration with the passage of time of the viscous elastic member 9.
In the illustrated embodiment, the suspension mechanism 13 is provided vertically to the elastic member attaching surface of the reproduction mechanism portion 2, but it can be attached in a diagonal direction thereto in accordance with the direction, the kinds or the like of the vibrations of the vehicle, whereby the stresses can be absorbed more effectively.
In the illustrated embodiment, the present invention is applied to a disc player, but the present invention can be also applied to a tape recorder aboard a vehicle with an effect of enhancing the wow flutter property aboard a vehicle.
As evident from the foregoing description, according to the present invention, there are provided a first elastic element for supporting the weight of the reproduction mechanism portion and a second elastic element for absorbing vibrations applied to the reproduction mechanism portion, whereby stresses applied to the reproduction mechanism portion are effectively absorbed and the reproduction mechanism portion is effectively protected. Furthermore, the weight of the reproduction mechanism portion is not applied to the second elastic element in the stationary state, whereby the suspension mechanism withstands a long period of use. | A suspension mechanism for an acoustic apparatus which includes a reproduction mechanism portion and a container for containing the same, the suspension mechanism provided between the reproduction mechanism portion and the container; and the suspension mechanism includes a first elastic element for supporting the weight of the reproduction mechanism portion, and a second elastic element for absorbing vibrations transmitted to the reproduction mechanism portion. | 6 |
RELATED APPLICATION DATA
[0001] This application is a divisional application of U.S. patent application Ser. No. 14/797,639, filed Jul. 13, 2015, entitled “ORC TURBINE AND GENERATOR, AND METHOD OF MAKING A TURBINE,” which application is a divisional application of U.S. patent application Ser. No. 13/937,978, filed Jul. 9, 2013, entitled “Overhung Turbine and Generator System With Turbine Cartridge,” now patented, which application claims the benefit of priority of U.S. Provisional Patent Application No. 61/699,649, filed Sep. 11, 2012, entitled “Axial Overhung Turbine and Generator System For Use In An Organic Rankine Cycle.” All of these applications are incorporated herein by reference in their entirety.
FIELD OF THE INVENTION
[0002] The present invention generally relates to the field of turbine generator power systems for industrial waste heat recovery and other applications. In particular, the present invention is directed to an overhung turbine coupled to a direct-drive, electrical power generator.
BACKGROUND
[0003] Concerns about climate change and rising energy costs, and the desire to minimize expenses in various industrial operations, together lead to an increased focus on capturing waste heat developed in such operations. Organic Rankine Cycle (“ORC”) turbine generator electrical power systems have been used in industrial waste heat recovery. Unfortunately, known systems for capturing waste heat and converting it to electricity are often too large for the space available in certain industrial operations, are less efficient than desired, require more heat to operate efficiently than is available, are too expensive to manufacture for certain applications, or require more maintenance than is desired. In other applications, such as geothermal energy recovery and certain ocean thermal energy projects, abundant heat is available and an efficient ORC system is a satisfactory means for conversion of such heat to electricity. Even in such other applications, however, known ORC systems tend to be too expensive for some such applications, are less efficient than desired and/or require more maintenance than is desired.
SUMMARY OF THE INVENTION
[0004] In one implementation, the present disclosure is directed to a system for conversion of heat energy into electricity. The system includes an electric generator having a proximal end, a distal end, a generator rotor and a generator stator, said generator rotor being disposed for rotational movement within said stator about a rotational axis; and a turbine having at least one turbine stator and at least one turbine rotor supported for rotational movement relative to said at least one turbine stator about said rotational axis, said at least one turbine rotor being coupled with said generator rotor so as to rotationally drive said generator rotor, wherein said turbine includes a housing having a cavity, said at least one turbine stator includes a plurality of stator plates, and said at least one turbine rotor includes a plurality of turbine rotor plates, further wherein said plurality of stator plates and said plurality of turbine rotor plates together form a cartridge that is sized and configured to be releasably mounted in said cavity in said housing.
[0005] In another implementation, the present disclosure is directed to a turbine cartridge designed to be releasably mounted in a cavity of turbine housing. The cartridge includes a plurality of rotor plates, each having a centerline, a first rotor plate contact surface, and a second rotor plate contact surface contacting said first contact surface; a plurality of stator plates, each having a centerline, a first stator plate contact surface, and a second stator plate contact surface contacting said first stator plate contact surface; and wherein said plurality of rotor plates are positioned in alternating relationship with corresponding respective ones of said plurality of stator plates so as to define a multi-stage rotor assembly with an upstream direction, and further wherein the size and configuration of said plurality of rotor plates and plurality of stator plates is selected so that said cartridge may be releasably mounted in a cavity of a turbine housing.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] For the purpose of illustrating the invention, the drawings show aspects of one or more embodiments of the invention. However, it should be understood that the present invention is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:
[0007] FIG. 1 is a schematic depiction of an ORC turbine-generator system;
[0008] FIG. 2 is a schematic depiction of the turbine and generator of the system shown in FIG. 1 , with interior details of the generator being schematically illustrated;
[0009] FIG. 3 is similar to FIG. 1 , except that an alternative embodiment of the ORC turbine-generator system is depicted;
[0010] FIG. 4 a is a cross-sectional view of a multi-stage axial turbine embodiment of the turbine assembly depicted in FIG. 1 and a partially broken-away view of the generator depicted in FIG. 1 showing, schematically, bearings included in one embodiment of the generator, with the rotor and stator of the generator removed for clarity of illustration;
[0011] FIG. 4 b is similar to FIG. 4 a , except that a single-stage radial turbine embodiment of the turbine assembly depicted in FIG. 1 is shown;
[0012] FIG. 4 c is similar to FIG. 4 b , except that a multi-stage radial turbine embodiment of the turbine assembly depicted in FIG. 4 b is shown;
[0013] FIG. 4 d is similar to FIG. 4 c , except that the rotors of the multi-stage radial turbine assembly depicted in FIG. 4 c are arranged in back-to-back configuration;
[0014] FIG. 5 is cross-sectional view of one embodiment of a turbine cartridge usable in the turbine shown in FIG. 4 a;
[0015] FIG. 6 is an enlarged cross-sectional view of a portion of the turbine shown in FIG. 4 a , illustrating a portion of the hood backplate and the entire turbine cartridge;
[0016] FIG. 7 is a perspective view showing the relative placement of two stator plates and one rotor plate with its stationary spacer plate used in a multi-stage embodiment of the turbine depicted in FIG. 4 a;
[0017] FIG. 8 is a perspective view of three rotor plates used in a multi-stage embodiment of the turbine depicted in FIG. 4 a showing the relative placement of the plates;
[0018] FIG. 9 is a cross-sectional side view of a portion of the turbine shown in FIG. 6 illustrating brush seals and other details of the turbine; and
[0019] FIG. 10 is similar to FIG. 9 , except that it depicts an alternative embodiment of the turbine.
DETAILED DESCRIPTION
[0020] The present disclosure is directed to a turbine powered electrical generator for use in an Organic Rankine Cycle (ORC), Kalina cycle, or other similar cycles, industrial operations that generates waste heat, or in connection with other heat sources, e.g., a solar system or an ocean thermal system. High-pressure hot gas from a boiler, which is heated by the heat source, enters the turbine housing and is expanded through the turbine to turn the rotor, which turns the generator shaft to generate electricity, as described more below.
[0021] Referring to FIG. 1 , turbine-generator assembly 20 is intended for use in an ORC system 22 . For convenience of discussion, system 22 is referred to and described as ORC system 22 . It is, however, to be appreciated that other thermodynamic processes, such as a Kalina cycle process and bottoming cycle processes, are also encompassed by the present invention. Turbine-generator assembly 20 includes a turbine 24 and a generator 26 connected to, and driven by, the turbine. Before discussing turbine-generator assembly 20 in more detail, discussion of ORC system 22 is provided.
[0022] ORC system 22 includes a boiler 28 that is connected to a heat source 30 , such as waste heat from an industrial process. Boiler 28 provides high-pressure hot vapor via connection 32 to turbine 24 . As discussed more below, the hot vapor, aka, the working fluid, is expanded in turbine 24 , where its temperature drops, and is then exhausted from the turbine and delivered via fluid connection 34 to condenser 36 . In condenser 36 , the vapor cooled in turbine 24 is cooled further, typically to a liquid state, and then a first volume of such liquid is delivered via fluid connection 38 to pump 40 , where the liquid is returned via connection 42 to boiler 28 . This liquid is then reheated in boiler 28 by heat from heat source 30 through a heat exchanger or other structure (none shown) in the boiler and then, repeating the cycle, is returned as high-pressure hot vapor via fluid connection 32 to turbine 24 .
[0023] Turning now to FIGS. 1 and 2 , a second volume of the cooled liquid exiting condenser 36 is, in one embodiment, delivered by pump 50 via fluid connection 52 to vaporizer 54 and from the vaporizer to generator 26 via fluid connection 58 . Fluid from pump 50 is also delivered via fluid connection 56 to generator 26 , in particular cooling jacket 76 , discussed more below. In other embodiments, it may be desirable to omit pump 50 and instead deliver liquid that is output from pump 40 via fluid connection 57 to fluid connections 52 and 56 . Vaporizer 54 vaporizes at least some of the second volume of liquid from condenser 36 and delivers the cooling vapor via fluid connection 58 to generator 26 . As illustrated in FIG. 2 , generator 26 includes a fluid gap 70 , a stator 72 and a generator rotor 74 , with the fluid gap (e.g., gas or atomized liquid) being positioned between the stator and rotor. Generator rotor 74 rotates relative to stator 72 about rotational axis 106 .
[0024] The cooling vapor is introduced into gap 70 , and as the vapor passes through gap 70 it extracts heat from stator 72 and generator rotor 74 , which vapor is then exhausted via fluid connection 34 , along with the hot vapor exhausted from turbine 24 , for cooling by condenser 36 . Optionally, as illustrated in FIGS. 1 and 3 , vapor exhausted from generator 26 may be delivered via fluid connection 37 directly to condenser 36 rather than being combined with vapor exhausted from turbine 24 . Turbine 24 has a through flow rate and, in one embodiment, the second volume of the vapor (working fluid) introduced into gap 70 travels through the gap with a flow rate that is no more than 50% of the through flow rate. Typically, although not necessarily, generator 26 is hermetically sealed to ensure working fluid present in gap 70 does not escape except via fluid connection 34 , or fluid connection 37 , if provided.
[0025] Referring now to FIGS. 1-4 , in one embodiment generator 26 is surrounded by a cooling jacket 76 ( FIGS. 2 and 4 ) for cooling the generator. Cooling liquid pumped by pump 50 to generator 26 via fluid connection 56 is delivered to cooling jacket 76 via inlets 77 ( FIG. 4 ). As the cooling liquid circulates through cooling jacket 76 , it extracts heat from stator 72 and other components of generator 26 . After completing its passage through cooling jacket 76 , the cooling liquid, now somewhat hotter, is removed from generator 26 via fluid connection 78 , after exiting fluid outlet 79 in the cooling jacket, and returned to condenser 36 .
[0026] Turning next to FIGS. 2 and 3 , in another embodiment of ORC system 22 , atomized cooling liquid, rather than vaporized liquid, is provided to gap 70 in generator 26 . Except as specifically discussed below, the embodiment of ORC system 22 illustrated in FIG. 3 is essentially identical to the embodiment of the system shown in FIG. 1 , and so description of identical elements is not provided in the interest of brevity. Unlike the embodiment of ORC system 22 illustrated in FIG. 1 , no vaporizer is provided in the embodiment illustrated in FIG. 3 . Instead a portion of the cooling liquid delivered via fluid connection 56 to generator 26 is provided by fluid connection 80 to atomizer 82 positioned proximate to the generator. Atomizer 82 atomizes the cooling liquid, which is then delivered to gap 70 in generator 26 , where the relatively cool atomized liquid extracts heat from stator 72 and generator rotor 74 as it travels through the gap, including through the latent heat of vaporization with respect to portions of the atomized liquid that are vaporized by the heat in the stator and rotor. The atomized liquid is then extracted from generator 26 via fluid connection 34 along with the working fluid exhausted from turbine 24 . In FIGS. 2 and 3 , atomizer 82 is depicted in dotted view to indicate that it is an optional element used in connection with one embodiment of the invention. As discussed above, in one embodiment, the second volume of the atomized liquid (working fluid) introduced into gap 70 travels through the gap with a flow rate that is no more than 50% of the through flow rate of turbine 24 .
[0027] In some applications, it may be desirable to provide just cooling of stator 72 via cooling jacket 76 , and not provide vapor or atomized liquid to gap 70 . In other applications, the reverse may be desired.
[0028] Various high molecular weight organic fluids, alone or in combination, may be used as the working fluid in system 20 . These fluids include refrigerants such as, for example, R125, R134a, R152a, R245fa, and R236fa. In other applications fluids other than high molecular weight organic fluids may be used, e.g., water and ammonia.
[0029] System 22 also includes a power electronics package 86 connected to generator 26 . Package 86 converts the variable frequency output power from generator 86 to a frequency and voltage suitable for connection to the grid 87 , e.g. 50 Hz and 400 V, 60 Hz and 480 V or other similar values.
[0030] Discussing generator 26 in more detail, in one embodiment the generator is a direct-drive, permanent magnetic, generator. Such a construction is advantageous because it avoids the need for a gearbox, which in turn results in a smaller and lighter system 20 . Various aspects of the invention described herein may, of course, be effectively implemented using a generator having a gearbox mechanically coupled between turbine rotor 104 of turbine 24 and generator rotor 74 of generator 26 , and a suitable wound rotor that does not include permanent magnets, e.g., a doubly wound, induction-fed rotor. In addition, in certain applications direct-drive synchronous generators may be used as generator 26 . The rated power output of generator 26 will vary as a function of the intended application. In one embodiment, generator 26 has a rated power output of 5 MW. In another embodiment, generator 26 has a rated power output of 50 KW, and in yet other embodiments, generator 26 has a rated power output somewhere in between these values, e.g., 200 KW, 475 KW, 600 KW, or 1 MW. Rated power outputs for generator 26 other than those listed in the examples above are encompassed by the present invention.
[0031] To permit high-speed (e.g., on the order of 20,000-25,000 rpm) operation, and to minimize maintenance, it may be desirable in some embodiments of generator 26 to support generator rotor 74 for rotational movement using magnetic radial bearings 88 (see FIG. 4 ). In one embodiment, magnetic radial bearing 88 a is positioned adjacent an end of generator rotor 74 proximate turbine 24 and magnet radial bearing 88 b is positioned adjacent an opposite end of the rotor. As discussed more below, this placement of bearings 88 enables in large part the overhung construction of turbine 24 . Similarly, axial movement of generator rotor 74 may be controlled through the use of magnetic axial thrust bearing 89 . Magnetic radial bearings 88 and magnetic axial thrust bearing 89 are controlled by a controller 90 that adjusts power delivered to the bearings as a function of changes in radial and axial position of generator rotor 74 , as detected by sensors (not shown) coupled to the controller, all as well known to those of ordinary skill in the art.
[0032] In another embodiment of the invention, fluid-film bearings may be used in place of magnetic radial bearings 88 and thrust bearing 89 . For purposes of illustration, the schematic depiction of magnetic bearings 88 and 89 in FIG. 4 should be deemed to include, in the alternative, fluid-film bearings. As is known, fluid-film bearings support the total rotor load on a thin film of fluid, i.e., gas or liquid.
[0033] Optionally, in addition to magnetic bearings 88 and 89 , rolling element radial bearings 92 , e.g., radial bearings 92 a and 92 b, may be provided at opposite ends of rotor shaft 93 of generator rotor 74 surrounding the rotor shaft, typically adjacent magnetic bearings 88 a and 88 b, respectively. Rolling element radial bearings 92 support generator rotor 74 and its shaft 93 in substantially coaxial relation to rotational axis 106 when magnetic bearings 88 and 89 are not energized. More particularly, rolling element radial bearings 92 provide a rest point for generator rotor 74 when magnetic bearings 88 are not activated and provide a safe landing for the generator rotor in the event of a sudden electronic or power failure. It may be desirable in some cases to size rolling element radial bearings 92 to support generator rotor 74 with a relatively loose fit so that during operation when magnetic bearings 88 and 89 are energized, the rotor has limited, if any contact, with rolling element radial bearings 92 , even during times of maximum radial deflections of generator rotor 74 due to perturbations in the operation of magnetic bearings 88 . When fluid-film bearings are used in place of magnetic radial bearings 88 , rolling element radial bearings 92 are typically not required, although in some applications it may be desirable to include such radial bearings.
[0034] In one embodiment, rolling element radial bearings 92 are sized to permit rotor shaft 93 to deviate radially from perfect coaxial alignment with rotational axis 106 an amount that is 1.01 to 5 times as great as the maximum radial deviation of shaft 93 from rotational axis 106 that may occur when magnetic radial bearings 88 are fully activated, including during times of major radial deflection that may occur due to perturbations of the magnetic radial bearings, e.g., from a fluid dynamic instability or a failed control system or a power failure (without backup). In another embodiment, this deviation permitted by radial bearings 92 is about 2 to 3 times as great as the radial deviation of shaft 93 from rotational axis 106 that occurs when magnetic bearings 88 are activated, again including during major perturbations that occur over time. Rolling element radial bearings 92 are often referred to as “bumper bearings” or “backup bearings” in the art.
[0035] While beneficial for the reasons discussed above, rolling element radial bearings 92 also present a challenge because the radial clearance of such bearings is much higher than the desired clearances for the conventional seals (not shown in detail) of turbine 24 . Typical rolling element radial bearings 92 have a radial clearance on the order of 0.005 to 0.015 inch. By contrast, desired radial clearances for the seals of turbine 24 are typically on the order of 0.000-0.001 inch. As generator 26 is assembled, shipped and stored, or during a loss of levitation of generator rotor 74 during operation due to failure of magnetic bearings 88 , the generator rotor will drop to rolling element radial bearings 92 . A consequence of such “play” in generator rotor 74 is that portion of shaft 93 proximate rolling element radial bearings 92 , along with seals in turbine 24 , can be damaged over time. Indeed, in certain applications, as few as 1-10 “bumper” events can cause sufficient damage to components of turbine-generator assembly 20 that disassembly and repair/replacement of such components is required.
[0036] A solution to this problem is to add a radial brush seal 94 ( FIG. 4 ) adjacent one or more of magnetic bearings 88 and/or rolling element radial bearings 92 , or to substitute a brush seal for the rolling element radial bearings (i.e., the bumper bearings). As used in such context, brush seal 94 is designed to withstand substantial radial forces before deforming. Such deformation is temporary, with brush seal 94 being constructed so that it springs back quickly to its prior configuration. In other words, brush seal 94 is self-healing. The stiffness of each brush seal 94 is selected based upon the weight of generator rotor 74 and turbine rotor 104 (discussed below) coupled with the generator rotor, and the extent of radial movement of the rotors 74 and 104 that is permissible given the overall design and operating parameters, respectively, of generator 26 and turbine 24 . In one embodiment, the stiffness of brush seals 94 is selected so that the extent of radial deviation of generator rotor 74 from co-axial alignment with rotational axis 106 that occurs when the rotor is supported by just the brush seals is 1 to 5 times greater than the extent of maximum radial deviation of generator rotor 74 from co-axial alignment with rotational axis 106 that occurs when magnetic bearings 88 are fully activated and supporting generator rotor 74 for rotational movement through the course of normal operation. In another embodiment, such extent of radial deviation is 1.2 to 4 times greater than the extent of radial deviation of generator rotor 74 from co-axial alignment with rotational axis 106 that occurs when magnetic bearings 88 are fully activated and supporting generator rotor 74 for rotational movement through the course of normal operation. In another implementation, generator rotor 74 is free to move a first radial distance out of co-axial alignment with rotational axis 106 when magnetic bearings 88 are not activated and the generator rotor does not move radially more than a second radial distance out of co-axial alignment with rotation axis when supported by brush seals 94 . In this implementation, the second radial distance is no more than 0.8 times the first radial distance, and in some implementations ranges from 0.2 to 0.6 times the first radial distance.
[0037] Referring now to FIGS. 2 and 4-10 , turbine 24 will be described in more detail. In the embodiment illustrated in FIG. 4 a , turbine 24 is an overhung axial turbine and includes a housing 98 having an axial inlet 100 and a radial outlet 102 . Turbine 24 , in one embodiment, is a multi-stage turbine, with the embodiment shown in FIG. 4 a having three stages. In other embodiments discussed more below, turbine 24 may be a single-stage overhung radial turbine as show in FIG. 4 b , and a multi-stage overhung radial turbine as shown in FIG. 4 c . Consistent with this overhung configuration, no radial bearings are included in turbine 24 , 324 , 424 for radially supporting the rotor in the turbine for rotational movement, As discussed above, turbine 24 is constructed so that the working fluid is expanded as it is transported through the turbine, with the result that the cold end of the turbine, i.e., the end proximate radial outlet 102 , is positioned adjacent generator 26 . This arrangement reduces heat transfer from turbine 24 to generator 26 .
[0038] Turbine 24 includes a turbine rotor 104 that rotates about rotational axis 106 and a stator 108 that is fixed with respect to housing 98 . As discussed more below, in one example of turbine 24 featuring a modular design, turbine rotor 104 includes a plurality of individual bladed plates 110 and stator 108 includes a plurality of individual plates 112 positioned in alternating, inter-digitated relationship with the rotor plates, as best seen in FIGS. 5, 6 and 9 . Rotor plates 110 and stator plates 112 are positioned within housing 98 in the cavity 114 formed at the region between inlet 100 and outlet 102 . As best illustrated in FIGS. 9 and 10 , radially innermost portions of stator plates 112 are spaced from portions of turbine rotor 104 positioned between rotor plates 110 so as to form a gap 115 sealed by seals 116 provided on such radially innermost portion of the stator plates. In the portion of turbine 24 illustrated in FIG. 5 , a plurality of stator spacer segments 117 , one corresponding to each rotor plate 110 , is provided in alternating, inter-digitated relationship with radially outer portions of stator plates 112 . Each spacer segment 117 is positioned radially outwardly of a corresponding respective rotor plate 110 . In the alternative embodiments of turbine 24 illustrated in FIGS. 9 and 10 , spacer segments 117 are formed as an integral portion of stator plates 112 (spacer segments are not separately labeled in FIGS. 9 and 10 ). In any event, in each of these embodiments, each spacer segment 117 is sized with respect to its corresponding respective rotor plate 110 so that a gap 118 is provided between a radially outermost portion of the rotor plate and the radially innermost portion of the spacer segment. Seals 119 (see FIG. 9 ) may be provided in gap 118 in certain embodiments of turbine 24 .
[0039] As best illustrated in FIGS. 9 and 10 , each rotor plate 110 includes a first contact surface 130 and a second contact surface 132 that contacts the first contact surface. Similarly, each stator plate 112 includes a first contact surface 134 and a second contact surface 136 that contacts the first contact surface. Contact surfaces 130 , 132 , 134 and 136 are substantially flat and substantially parallel. Further, they are arranged to be substantially perpendicular to rotational axis 106 . In one embodiment, contact surfaces 130 , 132 , 134 and 136 are flat in the range 0.00005″ to 0.020″, and in certain embodiments in the range 0.0005″ to 0.005″, as measured with respect to a root mean square version of such surfaces. Further, in one embodiment contact surfaces 130 and 132 of rotor plates 110 , and contact surfaces 134 and 136 of stator plates 112 , deviate from perfectly parallel by an amount in the range 0.0001″ to 0.015″, and in certain embodiments in the range 0.0005″ to 0.005″. Spacer segments 117 , when provided, preferably have contact surfaces that are similarly flat and parallel to contact surfaces 130 , 132 , 134 , and 136 , as discussed above.
[0040] Referring now to FIGS. 7 and 8 , in certain implementations of turbine 24 , it may be desirable to circumferentially clock one rotor plate 110 with respect to an adjacent rotor plate, e.g., clocking rotor plate 110 a with respect to plate 110 b. Similarly, it may be desirable to circumferentially clock one stator plate 112 with respect to an adjacent stator plate, e.g., clocking stator plate 112 a with respect to plate 112 c . Desired performance specifications for turbine 24 will influence the extent of clocking provided, as those skilled in the art will appreciate. When pairs of rotor plates 110 being clocked both have an equal number of vanes 140 , in one embodiment a first rotor plate 110 , e.g., plate 110 a, is clocked with respect to a second adjacent rotor plate, e.g., plate 110 b, zero to one vane pitch, i.e., (0)S to (1)S. Similarly, when pairs of stator plates 112 being clocked both have an equal number of vanes 142 , in one embodiment a first stator plate 112 , e.g., plate 112 a is clocked with respect to an adjacent stator plate, e.g., plate 112 c , zero to one vane pitch, i.e., (0)S to (1)S. When pairs of rotor plates 110 being clocked both have an unequal number of vanes 140 , in one embodiment a first rotor plate 110 , e.g., plate 110 a, is clocked with respect to a second adjacent rotor plate, e.g., plate 110 b, somewhere in the range of 0 to 360 degrees. Similarly, when pairs of stator plates 112 being clocked both have an unequal number of vanes 142 , in one embodiment a first stator plate 112 , e.g., plate 112 a is clocked with respect to an adjacent stator plate, e.g., plate 112 c , somewhere in the range of 0 to 360 degrees. Known turbine flow analytical and experimental methods are used to guide selection of the optimal amount of clocking in this range of 0 to 360 degrees.
[0041] With continuing reference to FIGS. 7 and 8 , in one embodiment adjacent stator plates 112 are clocked with respect to one another using an alignment system featuring a plurality of circumferentially spaced bores 160 positioned along a peripheral section 162 of a stator plate 112 , e.g., stator 112 c, only five of which are illustrated in FIG. 7 for convenience of illustration. In one implementation, adjacent bores 160 are circumferentially spaced one vane pitch S. The alignment system also includes a bore 164 in a peripheral section 166 of spacer segments 117 . Further, a blind bore 168 may be provided in a peripheral section 170 of a stator plate 112 , e.g., stator plate 112 a, immediately adjacent the stator plate, e.g., stator plate 112 c, in which bores 160 are provided (rotor plate 110 b and spacer plate 117 are intervening, of course). In one embodiment, bores 160 , 164 and 168 are spaced a substantially identical radial distance from rotational axis 106 , and have a substantially identical diameter. The alignment system further includes pin 172 , which is sized for receipt, typically using a mild friction fit, in a selected one of bores 160 and in bore 164 . When so positioned, pin 172 locks stator plate 112 c in selected circumferential alignment with adjacent spacer segment 117 . The selected circumferential clocking between adjacent stator plates, e.g., plates 112 a and 112 c, is achieved by next locking spacer section 117 to stator plate 112 a using pin 174 inserted in bores 164 and 168 . A similar system for clocking adjacent rotor plates 110 may also be employed, as discussed more below in connection with FIGS. 9 and 10 . As discussed above, selection of one of the plurality of bores 160 that receives pin 172 is determined based on the extent of circumferential clocking desired between adjacent stator plates 112 . The present invention encompasses other approaches to circumferentially clocking adjacent rotor plates 110 and stator plates 112 , as those skilled in the art will appreciate.
[0042] With particular reference to FIG. 9 , rotor plates 110 and stator plates 112 are, in one implementation, spaced so that axial distance 178 between vanes 140 of a rotor plate 110 and vanes 142 of an adjacent stator plate 112 is in the range of two axial chords to ¼ of 1% of an axial chord, and in certain embodiments ⅓ to 1 chord, as measured with respect to the chord of the immediately upstream one of the rotor or stator plates. For example, vanes 140 of rotor plate 110 identified as R 3 in FIG. 9 are axially spaced distance 178 a from immediately adjacent vanes 142 of stator plate 112 identified as S 3 a chord distance C x ,S 3 that is in the range of two axial chords to ¼ of 1% of an axial chord, and in certain embodiments is spaced ⅓ to 1 chord. Additionally, the stage reaction for turbine 24 may be of any conventional level. When, however, axial thrust levels must be controlled to meet available thrust capability of generator 26 , then very low stage reaction may be desirable, with common values in one example ranging from −0.1 to 0.3 and often falling in the range of −0.05 to +0.15. When very low stage reaction cannot be achieved, for example with multi-stage radial inflow turbine 424 illustrated in FIG. 4 c , then the second stage may be reversed so that the two radial turbines work back-to-back, leaving the last stage discharge still facing the generator.
[0043] Referring to FIGS. 4-6, 9 and 10 , in connection with the assembly of this embodiment, rotor plates 110 and stator plates 112 are positioned in alternating, inter-digitated relationship. In one embodiment, rotor plates 110 include a plurality of bores 186 (see FIG. 5 ) in radially inner portions of the plates, which bores are sized to receive a fastener, such as bolt stud 188 , which extends through the plates and is secured to stub shaft 189 via threaded bores 190 in the stub shaft. Generator rotor shaft 93 may include a threaded male end 192 that is received in a threaded bore 194 in stub shaft 189 .
[0044] Stator plates 112 , and spacer segments 117 if provided, may, for example, be secured together in alternating, inter-digitated relationship so as to form a unitary cartridge 198 . The latter may be releasably secured in cavity 114 ( FIG. 6 ) of housing 98 using known fasteners and other devices. In one embodiment, cartridge 198 may be secured in cavity 114 by lock ring 200 , which is engaged with a snap fit in a correspondingly sized recess 201 in in the cavity. With this construction, when lock ring 200 is installed, stator plates 112 , and segments 117 when provided, are driven against shoulder 202 formed in cavity 114 in housing 98 , thereby holding the plates and segments securely in place. In certain embodiments of turbine 24 , rotor plates 110 may be secured together with pins 203 (see FIGS. 9 and 10 ) received in bores 204 (see FIGS. 8, 9 and 10 ) to ensure no relative rotational movement occurs between rotor plates. Similarly, in other embodiments of turbine 24 , stator plates 112 and spacers 117 may be secured together with pins 172 (see FIGS. 9 and 10 ), as discussed above, to ensure no relative rotational movement occurs. Pins 172 may also penetrate into floor 204 of housing 98 (such penetration not being shown) from the downstream-most spacer 117 or stator plate 112 , if desired to assure no relative motion. A nose cone 206 may be provided, with one embodiment being threadedly engaged with threaded bore 208 in the furthest upstream stator plate 112 (identified in FIGS. 9 and 10 as S 1 ). Alternatively, machine screws may be used to fasten nose cone 206 to first stator plate 112 . With reference to FIGS. 5, 6, 9 and 10 , in some implementations it may be desirable to rotationally align and secure together rotor plates 110 , stator plates 112 , and if provided, spacers 117 , using one or more pins 210 and/or one or more bolt studs 212 that extend through the rotor plates, stator plates and spacers. Pins 210 may be used for precision rotational alignment of rotor plates 110 , stator plates 112 and spacers 117 , and if received in these components with a sufficient force fit, may also hold these components together to form a unitary structure, namely unitary cartridge 198 . Bolt studs 212 , in addition to providing some measure of rotational alignment, also draw together the rotor plates, stator plates and spacers to form a unitary structure, namely unitary cartridge 198 .
[0045] By providing separate rotor plates 110 and stator plates 112 , and by making such plates relatively flat as discussed above, these plates may be assembled as a cartridge 198 (see FIG. 5 ) that may be positioned in and removed from cavity 114 in housing 98 as a unitary assembly. As discussed more below, the provision of cartridge 198 permits a universal turbine 24 to be readily adapted for its intended application and interchanged for maintenance or new loading requirements.
[0046] In some applications, it will be desirable to more substantially isolate generator 26 from turbine 24 . To achieve this objective, as best illustrated in FIG. 6 , it may be desirable to include a seal 220 surrounding stub shaft 189 of turbine 24 proximate the radially innermost portion of backplate 250 . Seal 220 may be implemented as a labyrinth seal, a brush seal, a close-tolerance ring seal or using other seals known in the art.
[0047] The embodiment of turbine 24 shown in FIGS. 4-6 , is designed to permit ready manufacture of versions of the turbine having differently sized rotors 104 and stators 108 . By providing a single housing 98 for turbine 24 while permitting construction of turbines with varying operating parameters using that single housing, the turbine can be manufactured on a cost-efficient basis to the specifications of a given application. This flexible design is achieved in part by designing and sizing housing 98 of turbine 24 so that the largest-diameter turbine rotor 104 contemplated for the turbine may be received within cavity 114 and through the use of the cartridge design discussed above. In particular, after the desired operating parameters of turbine 24 are determined for the application in which the turbine will be used, then the number and size of plates 110 used in turbine rotor 104 , and plates 112 and spacer segments 117 used in stator 108 , are determined.
[0048] Consistent with the objective of providing a turbine 24 that can be readily modified to meeting desired operating parameters, housing 98 is designed to facilitate such modification. One aspect of such design of housing 98 involves providing floor 204 with a thickness sufficient to accommodate turbine rotor 104 and stator 106 having varying radial heights. Δr, as measured between said rotational axis and an outermost portion of said at least one turbine rotor, said axial turbine including a hood having a floor with a first thickness, wherein said first thickness is selected to permit said floor to be machined on the inside to a thickness sufficient to accommodate said at least one turbine rotor with a radial dimension that varies between Δr and 1.4Δr. Further, housing 98 is provided with a configuration that permits easy access to floor 204 by conventional machine tools, e.g., a 5-axis CNC milling machine or a CNC lathe, that can be used to machine the floor so as to create a cavity 114 sized to receive turbine rotor 104 and stator 106 with the desired radial heights.
[0049] Another aspect of providing a modifiable housing 98 is to include a backplate 250 having a thickness that may be adjusted so as to selectively vary width l 4 , i.e., the distance l 4 between backplate 250 and housing wall 252 , and to selectively vary width l 1 , i.e., the exit width. In this regard, width l 4 may be varied so that it ranges from one half to four times the width of diffuser exit l 1 . Backplate 250 may be an integral portion of housing 98 in some embodiments and a separate element in others, as illustrated in FIG. 4 . Backplate 250 preferably includes one or more ports 254 through which vapor in gap 70 may be exhausted and delivered to the exhaust flow path of turbine 24 and ultimately via fluid connection 34 to condenser 36 . If desired, flow splitter 256 may be provided immediately downstream of turbine rotor 104 and stator 106 as another way to tailor the performance of turbine 24 . As another optional feature, an extension plate 258 may be added to nose 260 of floor 204 of housing 98 , as best seen in FIG. 6 .
[0050] Housing performance depends on several factors, but alignment of the entry flow at the housing inlet 100 and housing base dimensions are important as taught in the literature. A very good flow entry provides for diffuser exhaust flowing up the housing backplate 250 , as configured in FIG. 4 . An essential design variable is to set L 4 =l 4 /l 1 to a value of 0.5 to 4, often in the range of 2 to 3, in order to have high performance (maintaining good diffuser Cp). This means that the diffuser exit width (l 1 ) and the hood floor width (l 4 ) must be controlled. The exit width l 1 also controls the performance of the diffuser as it controls the diffuser overall area ratio, which is a first order design parameter; hence a conflict can arise. If l 1 is increased for the diffuser, it will hurt the housing. This is controlled by starting with a generous housing design to cover a wide range of power levels (up to 5 MW for certain designs) and then adjusting operating parameters by modifying backplate 250 and the nose 260 of floor 204 . Another design variable is to introduce diffuser splitter 256 ( FIG. 6 ), which gives independent control on l 1 , thereby permitting a selected change in the diffuser exit value. Further performance tailoring can be achieved by selection of an extension plate 258 ( FIG. 6 ) of suitable height and thickness.
[0051] Turbine 24 is depicted in FIG. 4 a as a multi-stage axial turbine 24 , but turbine-generator system 20 is not so limited. In this regard, and with reference to FIG. 4 b , in an alternative embodiment, turbine-generator system 20 may include a radial turbine 324 having a single stage. Like numbers are used in FIGS. 4 a and FIG. 4 b to identify like elements, and for brevity, a description of like elements is omitted in connection with the following description of radial turbine 324 . The latter includes a single rotor 104 and a single stator 108 . Like the axial turbine 24 depicted in FIG. 4 a , radial turbine 324 may be implemented as a unitary cartridge 198 that may be releasably secured to generator shaft 93 with a bolt stud 188 . Turbine 324 may include an inlet flange ring 333 , and an outer flow guide 334 attached to housing 98 with known fasteners. Nose cone 206 and stator 108 may be releasable secured to housing 98 with a known fastener, such as bolts 337 .
[0052] Turning next to FIG. 4 c , in an alternate embodiment, turbine-generator system 20 may include a multi-stage radial turbine 424 . Like numbers are used in FIGS. 4 a and FIG. 4 b to identify like elements, and for brevity, a description of like elements is omitted in connection with the following description of radial turbine 424 . The latter includes two rotors 104 and two stators 108 . Radial turbine 424 may be implemented as a unitary cartridge 198 that may be releasably secured to generator shaft 93 with a bolt stud 188 . Turbine 424 may include an inlet flange ring 333 , and an outer flow guide 334 attached to housing 98 with known fasteners. Nose cone 206 and stators 108 , together with intermediate flow guide 441 positioned between the stators, may be releasable secured to housing 98 with a known fastener, such as bolts 337 . The two stators 108 of turbine 424 and intermediate flow guide 441 may be secured together with bolts 339 or other known fasteners so as to create unitary cartridge 198 . Intermediate flow guide 441 is functionally analogous to stator spacers 117 in the version of turbine 24 illustrated in FIGS. 5 and 6 .
[0053] Depending on the desired balancing of thrust in turbine-generator system 20 , it may be desirable to configure rotors 104 of a multi-stage radial turbine in a back-to-back arrangement, as illustrated in FIG. 4 d with respect to radial turbine 524 . In this regard, rotor 104 a is positioned so it backs up to rotor 104 b, with the rotors being coupled to rotate together. Stator 108 is positioned between rotors 104 a / 104 b, and includes bearings 526 for rotatably supporting a portion of rotor 104 b that extends through the stator. Turbine 524 further includes a front face plate 550 through which gas transfer tubes 552 extend, with the gas transfer tubes terminating at interior plenum 554 . Gas flow entering turbine 524 flows into tubes 552 , is delivered to interior plenum 554 , exits the plenum causing rotor 104 a to rotate, flows over stator 108 , then drives rotor 104 b and finally exits the turbine.
[0054] Although not specifically illustrated, turbine-generator system 20 may also be implemented using a mixed-flow turbine. The latter is very similar in design to radial turbine generators 324 and 424 , and so is not separately illustrated.
[0055] By placing rotor 104 in a reverse orientation so that the low-pressure, cooled working fluid is discharged from the last rotor stage of turbine 24 proximate generator 26 , heat transfer to the generator is minimized, thereby prolonging generator life. The low-pressure exhaust of turbine 24 , as a consequence of its reverse orientation, draws the second volume of working fluid out of gap 70 in generator 26 via ports 254 and into the discharge stream of turbine 24 while balancing thrust forces sufficiently so that the generator thrust bearing 89 can handle the remaining axial load of turbine 24 . Such a design is efficient, compact and thermally efficient.
[0056] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the spirit and scope of the present invention. | A turbine-generator device for use in electricity generation using heat from industrial processes, renewable energy sources and other sources. The generator may be cooled by introducing into the gap between the rotor and stator liquid that is vaporized or atomized prior to introduction, which liquid is condensed from gases exhausted from the turbine. The turbine has a universal design and so may be relatively easily modified for use in connection with generators having a rated power output in the range of 50 KW to 5 MW. Such modifications are achieved, in part, through use of a modular turbine cartridge built up of discrete rotor and stator plates sized for the desired application with turbine brush seals chosen to accommodate radial rotor movements from the supported generator. The cartridge may be installed and removed from the turbine relatively easily for maintenance or rebuilding. The rotor housing is designed to be relatively easily machined to dimensions that meet desired operating parameters. | 5 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims benefit of priority to U.S. Provisional Application Ser. No. 61/267,640, filed Dec. 8, 2009, the entire contents of which are hereby incorporated by reference.
GOVERNMENT SUPPORT
[0002] The invention was made with government support under Grant No. 2R01 HL070715 from the National Institutes of Health. The government has certain rights in the invention.
FIELD OF THE INVENTION
[0003] The invention relates generally to the fields of autologous vein, vein graft, vein preservation, tissue preservation, intimal hyperplasia, vasospasm, pharmaceuticals, devices, and vascular biology.
BACKGROUND OF THE INVENTION
[0004] Human greater saphenous vein (HSV) remains the most commonly used conduit for coronary and peripheral arterial bypass grafting. HSV is typically harvested from the leg with direct surgical exposure or endoscopic vein harvest. The branches are ligated and the vein is removed and placed on the “back table” prior to implantation. Most surgeons place the HSV in heparinized saline solution at room temperature. The vein is cannulated at the distal end and manually distended (with a syringe) with heparinized saline. This allows for identification and ligation of side branches that have been missed during harvest. This manual distension leads to injury to the vein. The veins are also marked with a surgical skin marker to optimize orientation during implantation.
[0005] Of the more than 1 million coronary bypass procedures that are undertaken each year worldwide, 10-15% of coronary vein grafts undergo early thrombotic occlusion; an additional 10-15% occlude in the next 1-5 years due to intimal hyperplasia, with a further 30-40% occluding in the subsequent 5-7 years because of progressive atherosclerosis superimposed on intimal hyperplasia. Less than half of vein grafts remain patent after 12 years (Motwani & Topol, 1998). Vein graft occlusion leads to myocardial infarction, limb loss, and death.
[0006] The leading cause of failure of arterial bypass grafts is intimal hyperplasia (Clowes & Reidy, 1991). Despite the many recent technological advances in vascular interventions, intimal hyperplasia remains an expensive, morbid, and unsolved problem. Intimal hyperplasia is mediated by a sequence of events that include vascular smooth muscle proliferation, migration, phenotypic modulation, and extracellular matrix production (Allaire & Clowes, 1997; Mosse et al., 1985). This process leads to pathologic narrowing of the vessel lumen, graft stenoses, and ultimately graft failure (LoGerfo et al., 1983).
[0007] A number of drugs that have been tested for their capacity to inhibit intimal hyperplasia have failed in clinical trials. Antithrombotic and antiplatelet agents such as warfarin, clopidogrel, and aspirin, have little or no effect on intimal hyperplasia (Kent & Liu, 2004). Drug eluting stents have been shown to be effective in preventing restenosis after coronary angioplasty; however, no therapeutic has been approved for autologous conduits. Two large clinical trials for the prevention of coronary and peripheral vascular vein graft failure using an E2F decoy (a short sequence of DNA that binds to transcription factors, sequestering these proteins) to prevent smooth muscle proliferation failed in their primary endpoint. Data from these large clinical trials suggests that simply limiting the proliferation response is not adequate to prevent intimal hyperplasia (Mann et al., 1999; Alexander et al., 2005). Therefore mechanisms other than proliferation need to be targeted for successful prevention of vein graft failure.
[0008] Injury to the vein graft during harvest leads to vasospasm and intimal hyperplasia, which cause the grafts to occlude. Thus, it would be of great benefit to identify new surgical methods and therapeutics to prevent injury to the graft during harvest and subsequent intimal hyperplasia
SUMMARY OF THE INVENTION
[0009] Thus, in accordance with the present invention, there is provided a method of treating a vein explant prior to transplant comprising (a) providing a vein explant; (b) stabilizing the vein explants in a buffered solution comprising a P2X 7 receptor antagonist at a pH 7.0-7.6 to produce a stabilized vein explant; and (c) preserving functional viability of the stabilized vein explant. The method may further restore functional viability of the vein explant that before step (b) was not viable. Functional viability of smooth muscle is defined here as the ability to contract in response to depolarization or agonists. For endothelium, viability is defined the ability of pre-contracted vessels to relax in response to acetylcholine. Additionally, the buffered solution may further comprise heparin. The P2X 7 receptor antagonist may be erioglaucine/Blue Dye #1 or brilliant blue G, or a combination of these. Yet further, the buffered solution may comprise phosphate buffered saline, MOPS, Hepes, Pipes, acetate or Plasmalyte. The pH may be 7.35-7.45, or 7.0, 7.1, 7.2, 7.3, 7.4, 7.5 or 7.6.
[0010] Additionally, the buffered solution may further comprise magnesium sulfate or Hanks' Balanced Salt Solution.
[0011] Additionally, the buffered solution may further comprise one or more of an anti-contractile agent, an anti-oxidant agent, an oligosaccharide, a colloid agent, an anti-inflammatory agent, an endothelial function preservative, a metabolic regulator, a hydrogel, an inhibitor of heat shock protein 27 (HSP27), a regulator of HSP20, and/or an inhibitor of MAPKAP kinase 2.
[0012] Further, the anti-contractile agent may be at least one of a phosphodiesterase inhibitor (e.g., papaverine, sildenafil, tadalafil, vardenafil, udenafil, avanafil cilistizol, pentoxifylline, dipyridamole or a combination thereof), a calcium channel blocker (e.g., amlodipine, aranidipine, azelnidipine, barnidipine, cilnidipine, clevidipine, efonidipine, felodipine, lacidipine, lercanidipine, mandipine, nicardipine, nifedipine, nilvadipine, nimodipine, nisoldipine, netrendipine, prandipine or a combination thereof), a nitric oxide donor (e.g., sodium nitroprusside, nitroglycerin or a combination thereof), or a cyclic nucleotide analogue (dibutyryl cAMP, dibutyryl cGMP or a combination thereof), or a combination thereof.
[0013] Further, the anti-oxidant agent may be e.g., N-acetylcysteine, allopurinol, glutathione, mannitol, ascorbic acid, a tocopherol, a tocotrienol or a green tea phenol or a combination thereof.
[0014] Further, the oligosaccharide may be e.g., lactobionic acid, raffinose, or trehalose or a combination thereof.
[0015] Further, the colloid agent may be, e.g., hydroxyethyl starch, dextran, blood or albumin or a combination thereof.
[0016] Further, the anti-inflammatory agent may be, e.g., a corticosteroid (e.g., dexamethasone, hydrocortisone, cortisone, prednisone, prednisolone, methylprednisolone or a combination thereof), or a nonsteroidal anti-inflammatory (e.g., aspirin, ibuprophen, naproxen salicylic acid or a combination thereof), a MAPKAP kinase 2 inhibitor, anti-TNF-α, anti-IL-1-β, a Cox-2 inhibitor, or a combination thereof
[0017] Additionally, the endothelial function preservative may be, e.g., an angiotensin converting enzyme inhibitor (e.g., enalapril, ramipril, quinapril, perindopril, lisinopril, benazepril, monopril or a combination thereof), an angiotensin receptor inhibitor (e.g. losartan), a statin (e.g. atorvastatin, cerivastatin, fluvastatin, lovastatin, mevastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin or a combination thereof), metformin, aminoimidazole carboxamide ribonucleotide (AICAR) or an estrogen (e.g., estriol, estradiol, estrone, 17β-estradiol or a combination thereof).
[0018] Additionally, the metabolic regulator may be, e.g., glucose, adenosine amylin, calcitonin related gene peptide, insulin, or a combination thereof.
[0019] Additionally, the hydrogel may be composed of, for example, a natural polysaccharide such as alginate, dextran, chitosan, and glycosaminoglycan, or a hydrophilic polymer such as polyethylene glycol, methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, polyhydroxbuterate, or poly(n-isopropylacrylamide).
[0020] Further, the inhibitor of HSP27 may be, for example, an siRNA or miRNA that inhibits HSP27 expression, an anti-miRNA that enhances HSP20 expression, or a combination thereof.
[0021] Further, the inhibitor of MAPKAP kinase 2 may be, for example, a peptide inhibitor.
[0022] The explant may be marked with a non-alcohol based marker, such as, without limitation, erioglaucine/Blue Dye #1, indigotine, Allura Red AC, or brilliant blue G.
[0023] The method may further comprise flushing the lumen of the vein explant such that the internal flushing pressure does not exceed 200 mm Hg, or does not exceed 150 mm Hg.
[0024] In another embodiment, there is provided a vein transplant kit comprising (a) a tissue marking pen comprising a P2X 7 receptor antagonist; and (b) a physiologic buffered solution or reagents for making such. Additionally, the kit may further comprise a container suitable for bathing a vein explant. Additionally, the kit may further comprise one or more of heparin, an anti-contractile agent, an anti-oxidant agent, an oligosaccharide, a colloid agent, an anti-inflammatory agent, an endothelial function preservative, a metabolic regulator, a hydrogel, an inhibitor of a heat shock protein, magnesium sulfate, and/or an inhibitor of MAPKAP kinase 2.
[0025] The buffered solution may comprise, for example, phosphate buffered saline, MOPS, Hepes, Pipes, acetate or Plasmalyte. The buffered solution may be at pH 7.0-7.6, or at 7.35-7.45. The P2X 7 receptor antagonist may comprise, for example, erioglaucine/Blue Dye #1, Allura Red AC, brilliant blue G, or any combination thereof.
[0026] The kit may further comprise a device for flushing the lumen of a vein explant; said device is designed to prevent flushing pressures inside the vein explant of greater than 200 mm Hg, or greater than 150 mm Hg. The device may comprise a syringe and/or a catheter and a pop-off valve. Additionally, the syringe or catheter may comprise a bullet-shaped tip comprising a lumen for introduction into a proximal end of said vein explant. Additionally, the kit may further comprise a clamp designed to hold said vein explant.
[0027] Also provided is a device for flushing the lumen of a vein explant; said device is designed to prevent flushing pressures inside the vein explant of greater than 200 mm Hg, or greater than 150 mm Hg. The device may comprise a syringe and/or catheter and a pop-off valve. The syringe or catheter may comprise a bullet-shaped tip comprising a lumen for introduction into a distal end of said vein explant. Further, the device may further comprise a bullet-shaped plug lacking a lumen for introduction into a proximal end of said vein explant. Additionally, the device may further comprise a clamp designed to hold said vein explant.
[0028] Still yet another embodiment comprises a buffered solution of pH 7.0-7.6, wherein said buffered solution further comprises heparin and a P2X 7 receptor antagonist. The P2X 7 receptor antagonist may be, for example, erioglaucine/Blue Dye #1 or brilliant blue G, or a combination thereof. Additionally, the buffered solution may further comprise heparin, along with one or more of erioglaucine/Blue Dye #1, brilliant blue G, or both. Further, the buffered solution may comprise phosphate buffered saline, MOPS, Hepes, Pipes, acetate or Plasmalyte. Further, the pH may be 7.35-7.45, or 7.0, 7.1, 7.2, 7.3, 7.4, 7.5 or 7.6.
[0029] Additionally, the buffered solution may further comprise magnesium sulfate or Hanks' Balanced Salt Solution.
[0030] Additionally, the buffered solution may further comprises one or more of an anti-contractile agent, an anti-oxidant agent, an oligosaccharide, a colloid agent, an anti-inflammatory agent, an endothelial function preservative, a metabolic regulator, a hydrogel, an inhibitor of heat shock protein 27 (HSP27), a regulator of HSP20, an inhibitor of MAPKAP kinase 2, and/or combinations thereof.
[0031] Further, the anti-contractile agent may be a phosphodiesterase inhibitor (e.g., papaverine, sildenafil, tadalafil, vardenafil, udenafil, avanafil cilistizol, pentoxifylline, dipyridamole or a combination thereof), a calcium channel blocker (e.g. amlodipine, aranidipine, azelnidipine, barnidipine, cilnidipine, clevidipine, efonidipine, felodipine, lacidipine, lercanidipine, mandipine, nicardipine, nifedipine, nilvadipine, nimodipine, nisoldipine, netrendipine, prandipine), a nitric oxide donor (sodium nitroprusside, nitroglycerin or a combination thereof), or a cyclic nucleotide analogue (e.g. dibutyryl cAMP, dibutyryl cGMP or a combination thereof).
[0032] Further, the anti-oxidant agent may be, e.g., N-acetylcysteine, allopurinol, glutathione, mannitol, ascorbic acid, a tocopherol, a tocotrienol or a green tea phenol, or a combination thereof.
[0033] The oligosaccharide may be e.g., lactobionic acid, raffinose, trehalose, or a combination thereof.
[0034] The colloid agent may be, e.g., hydroxyethyl starch, dextran, blood or albumin or a combination thereof.
[0035] The anti-inflammatory agent may be, e.g., a corticosteroid (e.g. dexamethasone, hydrocortisone, cortisone, prednisone, prednisolone, methylprednisolone or a combination thereof), a nonsteroidal anti-inflammatory (e.g. aspirin, ibuprophen, naproxen salicylic acid or a combination thereof), a MAPKAP kinase 2 inhibitor, anti-TNF-α, anti-IL-1-β, a Cox-2 inhibitor or a combination thereof.
[0036] Further, the endothelial function preservative may be an angiotensin converting enzyme inhibitor (e.g., enalapril, ramipril, quinapril, perindopril, lisinopril, benazepril, monopril or a combination thereof), an angiotensin receptor inhibitor (e.g., losartan), a statin (e.g., atorvastatin, cerivastatin, fluvastatin, lovastatin, mevastatin, pitavastatin, pravastatin, rosuvastatin, simvastatin or a combination thereof), metformin, an estrogen (e.g., estriol, estradiol, estrone, 17β-estradiol or a combination thereof) or a combination thereof.
[0037] Further, the metabolic regulator may be e.g., glucose, adenosine amylin, calcitonin related gene peptide, insulin or a combination thereof.
[0038] Additionally, the hydrogel may be composed of a natural polysaccharide such as alginate, dextran, chitosan, and glycosaminoglycan, or a hydrophilic polymer such as polyethylene glycol, methylcellulose, hydroxymethylcellulose, hydroxyethylcellulose, polyhydroxbuterate, or poly(n-isopropylacrylamide).
[0039] Further, the inhibitor of HSP27 may be, for example, an siRNA or miRNA that inhibits HSP27 expression, an anti-miRNA that enhances HSP20 expression or a combination thereof.
[0040] The inhibitor of MAPKAP kinase 2 may be, e.g., a peptide inhibitor.
[0041] Thus, the compositions of the present invention have broad uses including use in healthcare by providing sterile medical devices and surface sterilization and decontamination.
BRIEF DESCRIPTION OF THE DRAWINGS
[0042] The following figures form part of the present specification and are included to further demonstrate certain aspects of the present invention. The invention may be better understood by reference to one or more of these figures in combination with the detailed description of specific embodiments presented herein.
[0043] FIG. 1 shows the variable smooth muscle functional viability in human saphenous vein.
[0044] FIGS. 2A-B show that the current surgical harvest techniques lead to decreased smooth muscle functional viability.
[0045] FIG. 3 demonstrates that the current surgical harvest techniques lead to reduced endothelial functional viability.
[0046] FIGS. 4A-B show that the current surgical harvest techniques reduce endothelial-independent relaxation of human saphenous vein.
[0047] FIG. 5 demonstrates that human saphenous vein grafts with blue markings displayed reduced smooth muscle functional viability.
[0048] FIG. 6 demonstrates that surgical skin marking reduced smooth muscle viability of human saphenous vein.
[0049] FIG. 7 shows surgical skin marking pens reduce the viability of pig saphenous vein.
[0050] FIG. 8 shows functional response (contractile response to KCl) correlates with cell viability in human saphenous veins.
[0051] FIG. 9 demonstrates that erioglaucine restores functional viability after stretch injury in porcine saphenous vein.
[0052] FIG. 10 shows that Allura Red did not restore stretch-induced injury in porcine saphenous veins.
[0053] FIG. 11 demonstrates that erioglaucine restores smooth muscle viability in human saphenous vein.
[0054] FIGS. 12A-C show that erioglaucine blocks BzATP-induced contraction in saphenous vein.
[0055] FIG. 13 demonstrates that the erioglaucine reduces intimal thickness in human saphenous vein in an organ culture model.
[0056] FIG. 14 shows erioglaucine reduces intimal layer thickening in distended porcine saphenous vein.
[0057] FIG. 15 demonstrates that manipulation during surgical preparation impair endothelial dependent relaxation in human saphenous vein.
[0058] FIG. 16 shows that a pressure release (pop-off) valve limits pressure in human saphenous vein during manual distention.
[0059] FIG. 17 shows that manual distension with a pressure release valve prevents loss of endothelial function in porcine saphenous vein.
[0060] FIG. 18A-B show that preincubation with papaverine inhibits histamine and KCl induced contractions in porcine coronary artery.
[0061] FIG. 19A-B show that preincubation with papaverine inhibits norepinephrine induced contractions in human saphenous vein.
[0062] FIG. 20 shows the vein harvest device kit.
DETAILED DESCRIPTION OF THE INVENTION
[0063] Thus, the present invention provides new methods and reagents with which to harvest, treat, preserve and transplant autologous conduits and inhibit intimal hyperplasia. The pH of the solution used to store autologous vein conduits prior to implantation, which includes heparinized saline, is highly acidic (pH 6.2). This acidic pH has been shown to reduce the functionality of the conduit. Moreover, the use of surgical skin markers comprising isopropyl alcohol, to mark the autologous conduits, also reduces the functionality of the conduit. Erioglaucine, otherwise known as FD&C blue dye #1, is not toxic to the vein and restores functional integrity after injury. It also has been shown that common manual distension of the vein can lead to intraluminal pressures greater than 300 mm Hg, which also has a deleterious effect on conduit functionality. Placing a pop off valve on the syringe reduces the maximal possible intraluminal pressure to 130-140 mm Hg, thereby protecting the vein conduit.
I. HARVEST SOLUTION
[0064] In one aspect, the present invention provides a buffered solution, pH 7.0-7.6, in which to place the vein after harvest. In one embodiment the buffer is phosphate buffered saline; however, MOPS, Hepes, Pipes, and acetate are alternative formulations. Magnesium sulfate (5 mM) can also be added to the solution to stabilize membranes.
[0065] Another buffer option is Plasma-Lyte 56 Injection (Multiple Electrolytes Injection, Type 1, USP) a sterile, nonpyrogenic, hypotonic solution in a single dose container for intravenous administration. Each 100 mL contains 234 mg of Sodium Chloride, USP (NaCl); 128 mg of Potassium Acetate, USP (C 2 H 3 KO 2 ); and 32 mg of Magnesium Acetate Tetrahydrate (Mg(C 2 H 3 O 2 )2·4H 2 O). It contains no antimicrobial agents. The pH is adjusted with hydrochloric acid.
[0066] In another aspect of the invention, the harvest solution can be prepared as a highly viscous solution such as that described in Seal & Panitch (2003). These authors described a rapidly forming polymer matrix with affinity-based controlled release properties was developed based upon interactions between heparin-binding peptides and heparin. Dynamic mechanical testing of 10% (w/v) compositions consisting of a 3:1 molar ratio of poly(ethylene glycol)-co-peptide (approximately 18,000 g/mol) to heparin (approximately 18,000 g/mol) revealed a viscoelastic profile similar to that of concentrated, large molecular weight polymer solutions and melts. In addition, the biopolymer mixtures recovered quickly following thermal denaturation and mechanical insult. These gel-like materials were able to sequester exogenous heparin-binding peptides and could release these peptides over several days at rates dependent on relative heparin affinity. The initial release rates ranged from 3.3% per hour for a peptide with low heparin affinity to 0.025% per hour for a peptide with strong heparin affinity. By altering the affinity of peptides to heparin, a series of peptides can be developed to yield a range of release profiles useful for controlled in vivo delivery of therapeutics.
II. SUPPLEMENTAL SOLUTION ADDITIVES
[0067] In another aspect of the invention, the solutions of the present invention may contain additional additives to address various protective aspects of the invention.
[0068] For example, the solutions of the present invention may include heparin (1-10 U/ml) to prevent thrombus formation. Heparin is a highly sulfated glycosaminoglycan that is widely used as an injectable anticoagulant, and has the highest negative charge density of any known biological molecule. It can also be used to form an inner anticoagulant surface on various experimental and medical devices such as test tubes and renal dialysis machines. Pharmaceutical grade heparin is derived from mucosal tissues of slaughtered meat animals such as porcine (pig) intestine or bovine (cow) lung.
[0069] Although used principally in medicine for anticoagulation, the true physiological role of heparin in the body remains unclear, because blood anti-coagulation is achieved mostly by endothelial cell-derived heparan sulfate proteoglycans. Heparin is usually stored within the secretory granules of mast cells and released only into the vasculature at sites of tissue injury. It has been proposed that, rather than anticoagulation, the main purpose of heparin is in a defensive mechanism at sites of tissue injury against invading bacteria and other foreign materials. In addition, it is preserved across a number of widely different species, including some invertebrates that do not have a similar blood coagulation system.
[0070] Native heparin is a polymer with a molecular weight ranging from 3 kDa to 50 kDa, although the average molecular weight of most commercial heparin preparations is in the range of 12 kDa to 15 kDa. Heparin is a member of the glycosaminoglycan family of carbohydrates (defined as an organic compound which has the empirical formula Cm(H2O)n; that is, consists only of carbon, hydrogen and oxygen, with a hydrogen:oxygen atom ratio of 2:1). Glycosaminoglycans (GAGs) or mucopolysaccharides are long unbranched polysaccharides consisting of a repeating disaccharide unit. The repeating unit consists of a hexose (six-carbon sugar) or a hexuronic acid, linked to a hexosamine (six-carbon sugar containing nitrogen).
[0071] Heparin, (which includes the closely-related molecule heparan sulfate) consists of a variably-sulfated repeating disaccharide unit. The main disaccharide units that occur in heparin are shown below. The most common disaccharide unit is composed of a 2-O-sulfated iduronic acid and 6-O-sulfated, N-sulfated glucosamine, IdoA(2S)-GlcNS(6S). For example, this makes up 85% of heparins from beef lung and about 75% of those from porcine intestinal mucosa. Not shown below are the rare disaccharides containing a 3-O-sulfated glucosamine (GlcNS(3S,6S)) or a free amine group (GlcNH 3 + ). Under physiological conditions, the ester and amide sulfate groups are deprotonated and attract positively-charged counterions to form a heparin salt. It is in this form that heparin is usually administered as an anticoagulant.
[0072] In another aspect, the harvest solution can be a hydrogel that coats the vessel to minimize volume while keeping the vessel moist. In addition, the hydrogel can contain a therapeutic to help maintain vasorelaxation. Hydrogels include those synthesized from hydrophilic polymers that are crosslinked through covalent bods such as poly (ethylene glycol), polyacrylamide, polyfumerate, poly(N-siopropyl acrylamide), etc., or any gel like material crosslinking through physical interactions including hydrophobic and ionic. Gels include polyurethanes, agarose and alginates.
[0073] In another aspect of the invention, the present invention includes papaverine (1 mM) to inhibit contraction and spasm of the vein. Alternative anti-spasmodic agents are nicardipine, sodium nitroprusside, nitroglycerine (0.5-1.0 mM), or dibutyryl cAMP (2 mM).
[0074] In another aspect of the invention, the present invention includes antioxidants to prevent oxidative damage to the vein. N-acetylcysteine (10 mM), allopurinol (1 mM), glutathione (3 mM), mannitol (30-60 mM), or green tea phenols (0.5-1.0 mg/ml) are particular antioxidants of interest.
[0075] In another aspect, the present invention provides oligosaccharides in the harvest solution to prevent desiccation of the graft. Lactobionic acid (100 mM), raffinose (30 mM), or trehalose (30 mM) are particular oligosaccharides. Lactobionic acid is a disaccharide that provides osmotic support and prevents cell swelling. Raffinose is a trisaccharide that provides hypertonicity. Trehalose is a disaccharide with water retention properties.
[0076] In another aspect, the present invention provides starch in the harvest solution to support colloid osmotic pressure. Hydroxyethyl starch (30-50 mM), dextran (40 g/l), blood, or albumin, are particularly contemplated colloid agents.
[0077] In another aspect of the invention, the present invention includes anti-inflammatory agents. Steroids such as dexamethasone (5-10 mg/l) or salicylic acid are examples of anti-inflammatory agents.
[0078] In another aspect of the invention, drugs will be included to prevent endothelial dysfunction. Angiotensin converting enzyme inhibitors, statins, metformin, AICAR and estrogens are examples of such drugs.
[0079] In another aspect of the invention, the present invention includes metabolic regulators. Glucose (200 mM), adenosine (5 mM), and insulin (100 U/ml) are particularly contemplated metabolic regulators.
[0080] In another aspect of the invention, the present invention includes a novel peptide inhibitor of MAPKAP kinase 2 (and related peptides) to reduce inflammation, enhance relaxation of the smooth muscle, and prevent spasm. PCT Applications US2007/16246 and US2008/72525 describe such inhibitors, and are incorporated by reference herein.
[0081] In another aspect of the invention, the present invention includes siRNA or miRNA to decrease the expression of HSP27 to prevent intimal hyperplasia. The sense strand siRNA sequences are 1) GACCAAGGAUGGCGUGGUGUU (SEQ ID NO: 1) and 2) AUACACGCUGCCCCCCGGUUU (SEQ ID NO: 2). The sense strand miRNA sequences are 1) miR-580 or miR-1300, AACUCUUACUACUUAGUAAUCC (SEQ ID NO: 3) and 2) miR-552, UUGUCCACUGACCAAUCUGUU (SEQ ID NO: 4). The anti-miR-320 sequence is: UCGCCCUCUCAACCCAGCUUUU Expression of the siRNA and miRNA is plasmid based or synthetic. Delivery of the DNA or synthetic oligo-duplexes can be performed via reversible permeabilization or pressurization (Monahan et al., 2009).
III. P2X 7 RECEPTOR ANTAGONISTS
[0082] Injury leads to prolonged release of ATP which can activate ATP receptors (Khakh & North, 2006). P2X receptors are a family of ligand-gated ion channels that bind extracellular ATP. The P2X 7 receptor is responsible for the ATP-dependent lysis of macrophages and is also found on human saphenous vein smooth muscle (Cario-Toumaniantz et al., 1998). Activation of the P2X 7 receptor can form membrane pores permeable to large molecules in human saphenous vein (Cario-Toumaniantz et al., 1998). This leads to increases in intracellular Ca 2+ which can activate caspases, and ultimately lead to cell death due to autolysis and apoptosis (Donnelly-Roberts et al., 2004). Activation of the P2X 7 receptor has been associated with activation of p38 MAPK pathway and changes in the actin cytoskeleton (Pfeiffer et al., 2004). Activation of P2X 7 receptor also leads to production and release of interleukins and other cytokines which contributes to an inflammatory response (Donnelly-Roberts et al., 2004). Recently, systemic administration of an antagonist of the P2X 7 receptor has been shown to improve recovery in a rodent model of stretch induced spinal cord injury (Peng et al., 2009).
[0083] A variety of P2X 7 receptor antagonists have been described in the literature. For example, Alcaraz et al. (2003) describe the synthesis and pharmacological evaluation of a series of potent P2X 7 receptor antagonists. The compounds inhibit BzATP-mediated pore formation in THP-1 cells. The distribution of the P2X 7 receptor in inflammatory cells, most notably the macrophage, mast cell and lymphocyte, suggests that P2X 7 antagonists have a significant role to play in the treatment of inflammatory disease. Carroll et al. (2009) review distinct chemical series of potent and highly selective P2X 7 receptor antagonists.
[0084] The following U.S. Patents, incorporated herein by reference, disclose P2X 7 receptor antagonists: U.S. Pat. Nos. 7,709,469, 6,812,226, 7,741,493 7,718,693 and 7,326,792. The following U.S. Patent Publications, incorporated herein by reference, disclose P2X 7 receptor antagonists: 2010/0292295, 2010/0292224, 2010/0286390, 2010/0210705, 2010/0168171, 2010/0160389, 2010/0160388, 2010/0160387, 2010/0160384, 2010/0160373, 2010/0144829, 2010/0144727, 2010/0105068, 2010/0075968, 2010/0056595, 2010/0036101, 2009/0264501, 2009/0215727, 2009/0197928, 2009/0149524, 2009/0005330, 2008/0132550, 2008/0009541, 2007/0122849, 2007/0082930, 2005/0054013, 2005/0026916 and 2002/0182646.
[0085] As discussed above, an aspect of the invention includes a marker that contains a non-toxic dye to mark the vein. FD&C Blue #1 (erioglaucine), an artificial food dye approved by the FDA (E #133), also has not only been shown to be non-toxic, but protective of harvest techniques that are injurious to saphenous veins and is a P2X 7 receptor antagonist. Brilliant blue G, an analog erioglaucine, also is contemplated as a P2X 7 receptor antagonist.
[0086] Indigotine (E132) is another dark blue artificial dye approved by the FDA. Fast Green (E143) is another bluish green artificial dye approved by the FDA. Natural dyes such as curcurmin or betanin are other alternatives. Curcumin is the principal curcuminoid of the spice tumeric and has antioxidant and anti-inflammatory properties. As a food additive, its E number is E100. Betanin is a red glycosidic food dye obtained from beets and is a natural food dye. Other possible dyes include genestein blue, evans blue, india ink, Allura Red AC, Tartazine, and Erythrosine.
IV. DEVICES
[0087] Preliminary studies, discussed below, demonstrate that currently used harvest techniques are injurious to saphenous veins. These data pose a new paradigm for thinking about vein graft failure and offer simple and straightforward approaches to ameliorate vein graft injury.
[0088] Thus, in another aspect of the invention, the present invention includes a “pop off” valve to prevent over distension of the vein during side branch ligation. Qosina pressure relief T valve (part # D002501) is one example. In another aspect of the invention, the present invention includes a “bullet tipped” needle that is used to secure the vein and a device to prevent stretch of the vein.
V. KITS
[0089] The present invention may also be embodimed in a kit for use in conjunction with surgical vein transplant procedures. The immunodetection kits will comprise, in suitable container means, various containers, devices and/or reagents, along with appropriate instructions for use.
[0090] In certain embodiments, the kit will comprise harvest solutions, or reagents for making such. The solutions or reagents would be provided in sterile form, optionally with sterile containers for mixing and storing harvest solutions. The kit may also advantageously comprise a chamber for bathing/storing transplant tissue following explant and prior to transplant. Various other supplemental additives described above may also be included.
[0091] Another element of the kit may be the inclusion of a surgical marking pen comprising a non-toxin dye/marker, as described above. The pen may be “preloaded” with the marker/dye, or may be provided empty, with the marker/dye in solution or in reagent form to be loaded into the pen by the user.
[0092] Further devices including a syringe, catheter, and/or tubing equipped or including a pop-off valve as described above. Also included may be a device for holding a vein in place, such as a clamp, optionally provided with a stand or base, permitting “hands-free” positioning of the graft for further treatment.
[0093] The container aspect of the kit will generally include means for holding at least one vial, test tube, flask, bottle, packet, syringe, catheter or other container in a secure and protected fashion, for example, in close confinement for commercial sale. Such means may include injection or blow-molded plastic containers into which the desired containers, devices or reagents are retained.
VI. EXAMPLES
[0094] The following examples are included to demonstrate preferred embodiments of the invention. It should be appreciated by those of skill in the art that the techniques disclosed in the examples which follow represent techniques discovered by the inventor to function well in the practice of the invention, and thus can be considered to constitute preferred modes for its practice. However, those of skill in the art should, in light of the present disclosure, appreciate that many changes can be made in the specific embodiments which are disclosed and still obtain a like or similar result without departing from the spirit and scope of the invention.
Example 1
Toxicity of Surgical Marking Pens to Vein Tissue
[0095] De-identified discarded segments of human saphenous vein were collected (n=66), after informed consent approved by the Institutional Review Board of the Vanderbilt University (Nashville, Tenn.), from patients undergoing coronary artery bypass or peripheral vascular bypass surgery. The veins were stored in a saline solution until the end of the surgical procedure at which time they were placed in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM raffinose, 5 mM adenosine, 3 mM glutathione, 1 mM allopurinol, 50 g/L hydroxyethyl starch, pH 7.4) and stored at 4° C. The vessels were tested within 24 hours of harvest. The presense of blue markings were assessed for each HSV. Rings 1.0 mm in width were cut from segments of saphenous vein dissected free of fat and connective tissue, stripped of the endothelium and were suspended in a muscle bath containing a bicarbonate buffer (120 mM NaCl, 4.7 mM KCl, 1.0 mM MgSO 4 , 1.0 mM NaH 2 PO 4 , 10 mM glucose, 1.5 mM CaCl 2 , and 25 mM Na 2 HCO 3 , pH 7.4), gassed with 95% O 2 /5% CO 2 at 37° C. The rings were manually stretched to 4 g of tension, and was maintained at a resting tension of 1 g was obtained and equilibtrated for ˜2 hr. Force measurements were obtained using a Radnoti Glass Technology (Monrovia, Calif.) force transducer (159901A) interfaced with a Powerlab data acquisition system and Chart software (AD Instruments, Colorado Springs, Colo.). To determine viability, the rings were contracted with 110 mM KCl (with equimolar replacement of NaCl in bicarbonate buffer), and the force generated was measured. Force was converted to stress ([Newtons (N)/m 2 ]=force (g)×0.0987/area, where area is equal to the wet weight [mg/length (mm at maximal length)] divided by 1.055) 10 5 N/m 2 . There was variability in the functional viability of the veins ( FIG. 1 ). Veins generating stress of ≦0.025×10 5 N/m 2 were considered non-viable (grey) and those generating stress of >0.025×10 5 N/m 2 were viable (black). 40% of the vein tested was non-viable. Each point represents a different patient and an aggregate of at least three separate rings from that patient.
[0096] Segments of human saphenous vein (n=8) were collected prior to preparation of the vein for transplantation into the arterial circulation (unmanipulated, UM) and after surgical preparation (after manipulation, AM). Preparation involves manual distension of the vein, marking with a surgical skin marker, and placing the vein in heparinized saline. The contractile response to 110 mM KCl ( FIG. 2A ) or phenylephrine (10 −6 M, FIG. 2B ) was determined and force generated was converted to stress (10 5 N/m 2 ). Manipulation during vein preparation led to decreased contractile response to KCl and phenylephrine ( FIGS. 2A-B ). Each point represents a different patient and an aggregate of the response of at least three separate rings from each patient.
[0097] Human saphenous veins were also precontracted with phenylephrine (10 −6 M) followed by treatment with carbachol (5×10 −7 M) to determine endothelial dependent relaxation (Furchgott et al., 1980). Segments of human saphenous vein (n=5) were collected prior to preparation of the vein for transplantation into the arterial circulation (unmanipulated, UM) and after surgical preparation (after manipulation, AM). Rings from each segment were suspended in a muscle bath, equilibrated in a bicarbonate buffer, and contracted with 110 mM KCl. After an additional 30 min equilibration in a bicarbonate buffer, rings were pre-contracted with 10 −6 M phenylephrine (PE) and treated with 5×10 −7 M carbachol. Force was measured and converted to stress 10 5 N/m 2 . Responses were expressed as % of maximum PE-induced contraction. Typical manipulation during surgical preparation led to reduced endothelial-dependent relaxation ( FIG. 3 ). UM veins had 28.74±3.542% endothelial-dependent relaxation whereas AM contracted in response to carbachol (−5.976±0.9172%).
[0098] Human saphenous veins were also precontracted with phenylephrine (10 −6 M) followed by treatment with sodium nitroprusside (10 −7 M) to determine endothelial independent relaxation. Segments of saphenous vein (n=6) were collected prior to harvest preparation (unmanipulated, UM) or after harvest preparation (after manipulation, AM). Rings from each segment were suspended in a muscle bath, equilibrated in a bicarbonate buffer, and contracted with 110 mM KCl. After an additional 30 min equilibration in a bicarbonate buffer, rings were pre-contracted with 10 −6 M phenylephrine (PE) and treated with 10 −7 M sodium nitroprusside. Typical manipulation during surgical preparation reduced endothelial-independent relaxation of human saphenous vein ( FIGS. 4A-B ). Representative force tracings of the UM and AM segments collected from the same patient in response to PE and SNP ( FIG. 4A ). The endothelial independent relaxation displayed by the two groups, expressed as % of maximum PE-induced contraction, were significantly different. UM veins displayed an 86.62+/−5.986% relaxation, whereas AM veins displayed a 4.292+/−1.397% relaxation ( FIG. 4B ).
[0099] Of the 38 veins collected from patients undergoing coronary artery bypass or peripheral vascular revascularization surgery, 16 of the veins did not have any visible color by surgical marking pen whereas 22 of the veins had visible color. Rings were cut from the veins, suspended in a muscle bath and equilibrated in bicarbonate buffer. The rings were contracted with 110 mM KCl and force generated was converted to stress (10 5 N/m 2 ). The force generated by the two groups of veins were significantly different ( FIG. 5 ). Veins that had visible blue marking displayed less contractile responses (0.047±0.014 10 5 N/m 2 ) than veins that had no visible marking (0.174±0.023 10 5 N/m 2 ).
[0100] De-identified discarded segments of human saphenous vein that did not have any color were used to test the effect of different marking methods. Rings cut from the segments were either left unmarked (control; n=12), marked with a surgical skin marker (Cardinal Health, #5227 violet marking ink; n=5), marked in 50% isopropyl alcohol, a solvent used in the skin marker (n=4), or marked with methylene blue (Akorn, Inc., Lake Forest Ill.; n=10) and incubated for 15 min at room temperature. The rings were stripped of the endothelium and were suspended in a muscle bath containing a bicarbonate buffer (120 mM NaCl, 4.7 mM KCl, 1.0 mM MgSO 4 , 1.0 mM NaH 2 PO 4 , 10 mM glucose, 1.5 mM CaCl 2 , and 25 mM Na 2 HCO 3 , pH 7.4), gassed with 95% O 2 /5% CO 2 at 37° C. The rings were manually stretched to 4 g of tension, and were maintained at a resting tension of 1 g and equilibtrated for ˜2 hr. Force measurements were obtained using a Radnoti Glass Technology (Monrovia, Calif.) force transducer (159901A) interfaced with a Powerlab data acquisition system and Chart software (AD Instruments, Colorado Springs, Colo.). The rings were contracted with 110 mM KCl (with equimolar replacement of NaCl in bicarbonate buffer), and the force generated was converted to stress 10 5 N/m 2 . The three marked groups were significantly different from the control unmarked group (p≦0.05) ( FIG. 6 ). The rings that did not have markings had an average stress of 0.110±0.014 10 5 N/m 2 , the rings that were marked with the surgical skin marker had an average stress of 0.003±0.00110 5 N/m 2 , rings marked with 50% isopropyl alcohol had an average stress of 0.005±0.003 10 5 N/m 2 , and rings marked with methylene blue had an average stress of 0.014±0.01 10 5 N/m 2 .
[0101] Freshly isolated porcine saphenous veins were used to test the effect of different marking methods. The veins were collected and placed in cold transplant harvest buffer [100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM raffinose, 5 mM adenosine, 3 mM glutathione, 1 mM allopurinol, 50 g/L hydroxyethyl starch, pH 7.4]. The vessels were stored in transplant harvest buffer at 4° C. and tested within 24 hours of harvest and. To test the viability, rings 1.0 mm in width were cut from segments of saphenous vein and dissected free of fat and connective tissue. Saphenous vein rings were untreated (Control; n=6), marked with the surgical skin marker (n=3), or 50% isopropyl alcohol (the solvent used in the surgical marker; n=3) and incubated for 15 min at room temperature. The rings were then equilibrated in a muscle bath, contracted with KCl, and force was measured and converted to stress (10 5 N/m 2 ). The rings that did not have markings had an average stress of 0.263±0.039 N/m 2 , the rings that were marked with the surgical skin marker had an average stress of 0.114±0.017 N/m 2 , and rings marked with 50% isopropyl alcohol had an average stress of 0.00005±0.00005 N/m 2 . The two marked groups were significantly different from the control unmarked group (p≦0.05). ( FIG. 7 ).
Example 2
Live Vein Cells Correlate with Functional Viability
[0102] A live cell assay was used to determined cellular viability of human saphenous vein. De-identified discarded segments of saphenous vein (n=13) were collected, after informed consent approved by the Institutional Review Board of the Vanderbilt University (Nashville, Tenn.), from patients undergoing coronary artery bypass or peripheral vascular bypass surgery. The veins were stored in a saline solution until the end of the surgical procedure at which time they were placed in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM raffinose, 5 mM adenosine, 3 mM glutathione, 1 mM allopurinol, 50 g/L hydroxyethyl starch, pH 7.4). The vessels were stored in transplant harvest buffer at 4° C. and tested within 24 hours of harvest. Each vein was subject to physiologic experiment and live cell assay using 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT). To test the viability, rings 1.0 mm in width were cut from segments of saphenous vein dissected free of fat and connective tissue, some were stripped of the endothelium and suspended in a muscle bath containing a bicarbonate buffer (120 mM NaCl, 4.7 mM KCl, 1.0 mM MgSO 4 , 1.0 mM NaH 2 PO 4 , 10 mM glucose, 1.5 mM CaCl 2 , and 25 mM Na 2 HCO 3 , pH 7.4), gassed with 95% O 2 /5% CO 2 at 37° C. The rings were manually stretched to 4 g of tension, and was maintained at a resting tension of 1 g was obtained and equilibtrated for ˜2 hr. Force measurements were obtained using a Radnoti Glass Technology (Monrovia, Calif.) force transducer (159901A) interfaced with a Powerlab data acquisition system and Chart software (AD Instruments, Colorado Springs, Colo.). The rings were contracted with 110 mM KCl (with equimolar replacement of NaCl in bicarbonate buffer), and the force generated was measured. Any tissue failing to contract with KCl was considered non-viable. Force was converted to stress 10 5 N/m 2 for each ring and was averaged for each vein. To assess cellular viability, three rings from each vein were placed separately in 0.25 ml of 0.1% MTT solution (prepared in Dulbecco phosphate buffered saline, pH 7.4). For negative control, one ring was placed in 20 ml of water and microwaved for 10 min to inactivate any enzymatic activity before placing in the 0.1% MTT solution. The rings were incubated at 37° C. for 1 hr. The reaction was stopped by placing the rings in distilled water. The tissues was weighed and placed in 1 ml of CelloSolve (Sigma) for 4 hours at 37° C. to extract the formazan pigment each. The concentration of the pigment was measured at 570 nm using a spectrophotometer (Beckman Coulter). The absorbance of the negative control was subtracted from each sample. The viability index was expressed as OD 570 /mg/ml. The average for each vein was calculated from the three rings. The average stress obtained from each vein was then plotted against the average viability index.
[0103] The data depict a significant slope showing that there was a proportional relationship (R 2 =0.7262) between mitochondrial viability and the stress viability determined by the 110 mM KCl induced contraction ( FIG. 8 ). Representative HSV rings of low (left) and high (right) viability index are shown in the inset.
Example 3
Vein Harvest Solutions and Procedures
[0104] Freshly isolated porcine saphenous vein was collected in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM raffinose, 5 mM adenosine, 3 mM glutathione, 1 mM allopurinol, 50 g/L hydroxyethyl starch, pH 7.4). The vessels were tested within 24 hours of harvest and storage in transplant harvest buffer at 4° C. The vein was dissected free of fat and connective tissue and cut into 2 cm long segments. The segments were stretched to twice their resting length (stretched; n=7) or not manipulated (control; n=12). After stretching, the segments from both groups were further divided. A solution of erioglaucine (FCF, 2.6 mM, in 5% propylene glycol and water) or vehicle was then applied with a cotton swab in a longitudinal line to the untreated (FCF; n=8) or the stretched (Stretched+FCF; n=3) vein segments. The segments were incubated at room temperature for 15 min in Plasmalyte and then cut into rings. The rings were suspended in a muscle bath containing a bicarbonate buffer (120 mM NaCl, 4.7 mM KCl, 1.0 mM MgSO 4 , 1.0 mM NaH 2 PO 4 , 10 mM glucose, 1.5 mM CaCl 2 , and 25 mM Na 2 HCO 3 , pH 7.4), bubbled with 95% O 2 /5% CO 2 at 37° C. The rings were manually stretched to 4 g of tension, and maintained at a resting tension of 1 g and equilibtrated for ˜2 hr. Force measurements were obtained using a Radnoti Glass Technology (Monrovia, Calif.) force transducer (159901A) interfaced with a Powerlab data acquisition system and Chart software (AD Instruments, Colorado Springs, Colo. The rings were contracted with 110 mM KCl (with equimolar replacement of NaCl in bicarbonate buffer), and the force generated was converted to stress 10 5 N/m 2 ( FIG. 9 ). The control rings had an average stress of 0.47±0.034 N/m 2 , the rings that were marked with the erioglaucine dye had an average stress of 0.566±0.064 N/m 2 , and rings stretched had an average stress of 0.367±0.042 N/m 2 and the stretched rings with erioglaucine dye had an average stress of 0.713±0.111 N/m 2 . The stress for the stretched vein was significantly (*p<0.05) different from the control unstretched veins and the stretched vein with erioglaucine dye was significantly (#p<0.05) different when compared to stretched without erioglaucine dye ( FIG. 9 ).
[0105] However, treatment with another dye, Allura Red, did not restore functional viability after stretch injury of porcine saphenous vein ( FIG. 10 ), Porcine saphenous veins (n=4) were left untreated (Control) or stretched to twice their resting length (no dye), cut into rings and suspended in the bicarbonate buffer in a muscle bath. Rings from stretched segments were either incubated with 50 μM Allura Red (+Red) or 50 μM of erioglaucine (+FCF) for 30 min. The rings were then allowed to equilibrate in the bicarbonate buffer for before contracting with 110 mM KCl. Force generated was converted to stress (10 5 N/m 2 ). Data represent relative contractile response to Control rings which was set as 100%. The stress for the stretched vein was not significantly different from the stretched vein with Allura Red (NS). Erioglaucine significantly restored contractile response in the stretched vein (#p≦0.05) when compared to the stretched vein with Allura Red.
[0106] Effect of erioglaucine on human saphenous vein was determined using de-identified discarded segments of human saphenous vein from patients undergoing coronary artery bypass or peripheral vascular bypass surgery (n=4). The veins were stored in a saline solution until the end of the surgical procedure at which time they were placed in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM raffinose, 5 mM adenosine, 3 mM glutathione, 1 mM allopurinol, 50 g/L hydroxyethyl starch, pH 7.4). The vessels were tested within 24 hrs of harvest storage in transplant harvest buffer at 4° C. To test the viability, rings 1.0 mm in width were cut from segments of saphenous vein dissected free of fat and connective tissue, treated with either a solution of erioglaucine (FCF, 2.6 mM, in 5% propylene glycol and water) or vehicle and incubated for 30 min at room temperature. The tissues were then stripped of the endothelium and suspended in a muscle bath containing a bicarbonate buffer, gassed with 95% O 2 /5% CO 2 at 37° C. The rings were manually stretched to 4 g of tension, and was maintained at a resting tension of 1 g was obtained and equilibrated for ˜2 hr. Force measurements were obtained using a Radnoti Glass Technology (Monrovia, Calif.) force transducer (159901A) interfaced with a Powerlab data acquisition system and Chart software (AD Instruments, Colorado Springs, Colo.). The rings were contracted with 110 mM KCl (with equimolar replacement of NaCl in bicarbonate buffer), and the force generated was measured. Force was converted to stress 10 5 N/m 2 , and was plotted for vehicle and erioglaucine rings. Representative force tracings of rings left untreated (control) or treated with the erioglaucine dye (FCF) are depicted ( FIG. 11A ). The vehicle rings had an average stress of 0.015±0.012 N/m 2 , and the erioglaucine-treated rings had an average stress of 0.103±0.021 N/m 2 ( FIG. 11B ). The two groups were significantly different (p≦0.05).
[0107] Human saphenous vein segments were collected after harvest before surgical manipulation from patients undergoing coronary artery bypass or peripheral vascular bypass surgery and stored in PlasmaLyte. The vessels were tested within 2 hours of harvest. Freshly isolated porcine saphenous vein was collected in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM Raffinose, 5 mM Adenosine, 3 mM Glutathione, 1 mM Allopurinol, 50 g/L Hydroxyethyl starch, pH 7.4). The vessels were tested within 24 hours of harvest. Rings 1.0 mm in width were cut from porcine saphenous veins ( FIG. 12A , n=2) and unmanipulated human saphenous vein ( FIG. 12B , n=4) dissected free of fat and connective tissue. The rings were then stripped of the endothelium and suspended in a muscle bath containing a bicarbonate buffer, bubbled with 95% O 2 /5% CO 2 at 37° C. The rings were manually stretched to 4 g of tension, and was maintained at a resting tension of 1 g was obtained and equilibrated for ˜2 hr. Force measurements were obtained using a Radnoti Glass Technology (Monrovia, Calif.) force transducer (159901A) interfaced with a Powerlab data acquisition system and Chart software (AD Instruments, Colorado Springs, Colo.). Rings were contracted with 110 mM KCl. After an additional 30 min equilibration, rings were treated with either a solution of erioglaucine (FCF, 50-200 μM for 30 minutes) or vehicle for 30 min and then contracted with 100 μM BzATP. Force was measured and converted to stress. Response was expressed as % of maximal KCl contraction. Representative force tracing of human saphenous vein contracted with BzATP after pretreatment with vehicle (control) or 50 μM erioglaucine (FCF pretreatment) are depicted in FIG. 12C . Pretreatment with erioglaucine (FCF) but not the vehicle (Control) significantly inhibited BzATP induced contraction (*p<0.05) ( FIG. 12B ).
[0108] Segments of human saphenous vein were collected prior to preparation of the vein for transplantation into the arterial circulation (unmanipulated, UM) and after surgical preparation (after manipulation, AM) from the same patients in PlasmaLyte and were used within 2 hr of harvest. The segment was cut into ˜1 mm rings and one ring from each group was fixed in formalin (Pre-culture). The other rings were cultured in RPMI medium supplemented with 1% L-glutamine, 1% penicillin/streptomycin and 30% fetal bovine serum at 5% CO 2 and 37° C. in the absence (Control) or presence of 50 μM erioglaucine (FCF) for 14 days. After 14 days, the rings were fixed in formalin, sectioned at 5 μm and stained using Verhoff Van Gieson stain. Light micrograph of the rings was captured using an Axiovert 200 and intimal thickness was measured using AxioVision. Data represent % increase of intimal thickness related to basal intimal thickness of the pre-culture ring which was set as 0%. The error bars show the standard error of the mean. Manipulation during vein preparation increased the thickening of the intimal layer (#p=0.053 in paired t-test) and treatment with erioglaucine significantly (* p<0.05) inhibited the development of intimal thickness when compared to Control ( FIG. 13 ).
[0109] Fresh porcine saphenous vein was harvested by a no touch method under sterile conditions and stored in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM Raffinose, 5 mM Adenosine, 3 mM Glutathione, 1 mM Allopurinol, 50 g/L Hydroxyethyl starch, pH 7.4). The vessels were used within 24 hr of harvest. The veins were divided into three segments that were left untreated (Unmanipulated, n=7), distended (Distended, n=8) to >300 mm Hg, or distended in the presence of the pressure relief valve (Pop Off, n=7). Each segment was then cut into ˜1 mm rings and one ring from each condition was immediately fixed in formalin (Pre-culture). The other rings were cultured in RPMI medium supplemented with 1% L-glutamine, penicillin/streptomycin and 30% Fetal bovine serum at 5% CO 2 and 37° C. in the absence (Control) or presence of either 50 μM erioglaucine (FCF), 50 μM brilliant blue G (BBG) or 50 μM Allura Red (Red) for 14 days. After 14 days, the rings were fixed in formalin, sectioned at 5 μm and stained using Verhoff Van Gieson stain. Light micrograph of the rings was captured using a Axiovert 200 and intimal thickness was measured using AxioVision. Treatment with erioglaucine but not allura red inhibited distension induced increases in intimal thickening, * p<0.05 compared to Distended-Control ( FIG. 14 ).
[0110] Rings of human left internal mammary artery (LIMA; n=3) and saphenous veins were obtained prior to preparation of the vein for transplantation into the arterial circulation (unmanipulated, UM; n=5) and after surgical preparation (after manipulation, AM; n=5). Rings cut from the UM segments were incubated in University of Wisconsin Solution (UW), heparinized saline (HS), heparinized PlasmaLyte (HP) or heparinized PlasmaLyte containing 30 mM trehalose (HPT) for 2 hrs at room temperature. Rings were cut from the veins, suspended in a muscle bath and equilibrated in bicarbonate buffer. The rings were pre-contracted with 10 −6 M phenylephrine and then treated with 5×10 −7 M carbachol to determine endothelial dependent relaxation. Rings from the LIMA had greater endothelial dependent relaxation than saphenous vein ( FIG. 15 ). Manipulation during surgical preparation led to decreased endothelial dependent relaxation ( FIG. 15 ). Storage in heparinized saline [* p<0.05 compared to HS for all UM groups (UM, UW, HP, & HPT)], but not in heparinized plasmalyte, heparinized plasmalyte plus trehalose or transplant harvest solution led to decreased endothelial dependent relaxation ( FIG. 15 ). Data is presented as % relaxation (compared to the maximal phenylephrine induced contraction).
[0111] De-identified discarded segments of human saphenous vein (n=5) were collected, after informed consent approved by the Institutional Review Board of the Vanderbilt University (Nashville, Tenn.), from patients undergoing coronary artery bypass or peripheral vascular bypass surgery. The veins were stored in a saline solution until the end of the surgical procedure at which time they were placed in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM raffinose, 5 mM adenosine, 3 mM glutathione, 1 mM allopurinol, 50 g/L hydroxyethyl starch, pH 7.4). The vessels were tested within 24 hours of harvest and storage in transplant harvest buffer at 4° C. A pop off valve was connected to a syringe at one end and to a cannulated saphenous vein at the other. The distal end of the saphenous vein was also cannulated and connected to a pressure transducer. Pressure was monitored while the vein was distended with a hand held syringe with and without the pressure release valve. The pressure monitor would not measure pressures above 300 mmHg. This created three groups and they were the following: pop-off pressure (Popoff), max pressure with pop-off valve (Max with valve), and max pressure without pop-off valve (Max without valve). The veins that had a pop-off valve had a mean pressure of 129±1.265 mm Hg and maximum pressure of 141.8±1.985 mm Hg, while the veins with out the pop off valve had a maximum pressure of 300±0.00 mm Hg ( FIG. 16 ). The average and maximum pressure in the veins with the pop-off valve were significantly different from the veins without the pop-off valve (p≦0.05).
[0112] Fresh porcine saphenous vein was harvested by a no touch method under sterile conditions and stored in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM Raffinose, 5 mM Adenosine, 3 mM Glutathione, 1 mM Allopurinol, 50 g/L Hydroxyethyl starch, pH 7.4). The vessels were used within 24 h of harvest. Veins (n=4) were manually distended with a syringe in the absence (Distended) or presence of an in line pressure release valve (pop-off). Control segments were not distended (ND). After distension, rings were cut from the segments and suspended in a muscle bath. The rings were precontracted with 10 −6 M phenylephrine and then treated with 5×10 −7 M carbachol to determine endothelial dependent relaxation. Data is presented as the % relaxation (compared to the maximal phenylephrine induced contraction). Manual distension with a hand held syringe led to significant decreases (p<0.0005) in endothelial dependent relaxation and the pressure release valve prevents this loss of endothelial dependent relaxation ( FIG. 17 ).
[0113] Porcine coronary arteries were freshly isolated from euthanized pigs and placed directly into cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM Raffinose, 5 mM Adenosine, 3 mM Glutathione, 1 mM Allopurinol, 50 g/L Hydroxyethyl starch, pH 7.4). Coronary arteries were dissected free of fat and adventitial tissues and the endothelium was removed. Transverse rings (1.0 mm thickness) were cut and suspended in muscle bath, via silk 3-0 linked to force transducers (Kent Scientific, CT) interfaced with a Data Translation A-D board (Data Translation, MA). Data was acquired with the Power Lab software program. Porcine coronary artery rings were suspended in a muscle bath and equilibrated in Krebs Ringer bicarbonate buffer for 2 h. The rings were stretched and the length progressively adjusted until maximal tension was obtained. The rings were contracted with 110 mM KCl (with equimolar replacement of NaCl in bicarbonate buffer), and the force generated was measured and converted to stress [Newtons (N)/m 2 ]=force (g)×0.0987/area, where area is equal to the wet weight [mg/length (mm at maximal length)] divided by 1.055. Rings were washed and equilibrated for another 30 mins. Rings were treated with 5 μM histamine, 110 mM KCl, 1 mM papaverine (PAP), 1 mM papaverine for 10 min followed by 5 μM histamine or 1 mM papaverine for 10 min followed by 110 mM KCl and force generated was measured- and converted to stress. Representative force tracings of rings treated with 5 μM histamine (Hist), 110 mM KCl (KCl), 1 mM papaverine (PAP), 1 mM papaverine for 10 min followed by 5 μM histamine (Pap+Hist) or 1 mM papaverine for 10 min followed by 110 mM KCl (Pap+KCl) were depicted in FIG. 18A . Decrease in stress was converted to a percentage of the maximal initial KCl contraction which was set as 100%. Papaverine treatment reduced basal tension in the rings (−15.0±3.135%) ( FIG. 18B ). Pretreatment of rings with papaverine completely inhibited histamine (−12.0±4.163 compared to 98.613±11.049) and KCl (−20.0±10.00 compared to 103.33±2.404%) induced contraction ( FIG. 18B ).
[0114] De-identified discarded segments of human saphenous vein (n=6) were collected, after informed consent approved by the Institutional Review Board of the Vanderbilt University (Nashville, Tenn.), from patients undergoing coronary artery bypass or peripheral vascular bypass surgery. The veins were stored in a saline solution until the end of the surgical procedure at which time they were placed in cold transplant harvest buffer (100 mM potassium lactobionate, 25 mM KH 2 PO 4 , 5 mM MgSO 4 , 30 mM raffinose, 5 mM adenosine, 3 mM glutathione, 1 mM allopurinol, 50 g/L hydroxyethyl starch, pH 7.4). The vessels were tested within 24 hrs of harvest and storage in transplant harvest buffer at 4° C. Veins were cleaned off fat and adventitial tissues and the endothelium was removed. Transverse rings (1.0 mm thickness) were cut and suspended in muscle bath, via silk 3-0 linked to force transducers (Kent Scientific, CT) interfaced with Powerlab data acquisition system and Chart software (AD Instruments, Colorado Springs, Colo.). Human saphenous vein rings were suspended in a muscle bath and equilibrated in Krebs Ringer bicarbonate buffer for 2 hr. The rings were stretched and the length progressively adjusted until maximal tension was obtained. The rings were contracted with 110 mM KCl (with equimolar replacement of NaCl in bicarbonate buffer), and the force generated was measured and converted to stress [Newtons (N)/m 2 ]=force (g)×0.0987/area, where area is equal to the wet weight [mg/length (mm at maximal length)] divided by 1.055. Rings were washed and equilibrated for another 30 mins. Rings were treated with 0.5 μM norepinephrine (NE), 1 mM papaverine (Pap), or 1 mM papaverine for 10 min followed by 0.5 μM NE and force generated was measured and converted to stress. Decrease in stress was converted to a percentage of the maximal initial KCl contraction which was set as 100%. Representative force tracings of rings treated with 0.5 μM NE (NE), 1 mM papaverine (Pap), or 1 mM papaverine for 10 min followed by 0.5 μM NE were depicted in FIG. 19A . Decrease in stress was converted to a percentage of the maximal initial KCl contraction which was set as 100%. n=6. Papaverine treatment reduced basal tension in the rings (−9.772.0±3.226%). Pretreatment of human saphenous vein with papaverine completely inhibited NE (−3.210±5.119 compared to 89.935±18.344%) induced contraction ( FIG. 19B ).
[0115] Vein harvest device is shown in FIG. 20 . The distal end of the vein (the vein is reversed because of valves in the vein) is cannulated with a bullet tipped plastic catheter which has a lumen for irrigation and secured to the catheter with a spring loaded clamp. The catheter is clipped into the base. An additional bullet tipped catheter with no lumen is attached to the proximal end of the vein clipped into the opposite end of the base. The device is ratcheted open until the vein is at the same length as in vivo. A syringe with extension tubing and an in line pressure release valve is attached to the distal end of the vein. The vein can now be distended and side branches ligated.
Example 4
Prophetic Clinical Protocol
[0116] The greater saphenous vein will be surgically harvested using standard surgical technique. The distal end of the vein will be cannulated with a bullet tipped vein cannula and secured with either a clamp or a silk tie. The pressure release valve will be attached to the cannula with a 10 or 20 cc syringe attached to the other end of the valve. In some cases, extension tubing will be placed between the syringe and the valve. The vein will be distended with the vein harvest solution and tributaries identified and ligated with either silk ties or clips. The vein will be marked with the marker in the kit along one long surface to maintain orientation of the vein. In some cases, the vein may be marked prior to removal from the patient. The vein will then be placed in the harvest solution until implanted into the arterial circulation. In one embodiment, the dye from the pen will contain a P2X 7 receptor antagonist, and the harvest solution will not contain a P2X 7 receptor antagonist. In another embodiment, the dye from the pen will not contain a P2X 7 receptor antagonist, but the solution will. In a third embodiment, both the pen dye and the solution will contain a P2X 7 receptor antagonist.
[0117] All of the compositions and/or methods disclosed and claimed herein can be made and executed without undue experimentation in light of the present disclosure. While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and/or methods and in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents which are both chemically and physiologically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.
VII. REFERENCES
[0118] The following references, to the extent that they provide exemplary procedural or other details supplementary to those set forth herein, are specifically incorporated herein by reference.
Motwani J G, Topol E J (1998) Aortocoronary saphenous vein graft disease: pathogenesis, predisposition, and prevention. Circulation 97: 916-931. Clowes A W, Reidy M A (1991) Prevention of stenosis after vascular reconstruction: pharmacologic control of intimal hyperplasia—a review. J Vasc Surg 13: 885-891. Allaire E, Clowes A W (1997) Endothelial cell injury in cardiovascular surgery: the intimal hyperplastic response. Ann Thorac Surg 63: 582-591. Mosse P R, Campbell G R, Wang Z L, Campbell J H (1985) Smooth muscle phenotypic expression in human carotid arteries. I. Comparison of cells from diffuse intimal thickenings adjacent to atheromatous plaques with those of the media. Lab Invest 53: 556-562. LoGerfo F W, Quist W C, Cantelmo N L, Haudenschild C C (1983) Integrity of vein grafts as a function of initial intimal and medial preservation. Circulation 68: II117-124. Kent K C, Liu B (2004) Intimal hyperplasia—still here after all these years! Ann Vasc Surg 18: 135-137. Mann M J, Whittemore A D, Donaldson M C, Belkin M, Conte M S, et al. (1999) Ex-vivo gene therapy of human vascular bypass grafts with E2F decoy: the PREVENT single-centre, randomised, controlled trial. Lancet 354: 1493-1498. Alexander J H, Hafley G, Harrington R A, Peterson E D, Ferguson T B, Jr., et al. (2005) Efficacy and safety of edifoligide, an E2F transcription factor decoy, for prevention of vein graft failure following coronary artery bypass graft surgery: PREVENT IV: a randomized controlled trial. Jama 294: 2446-2454. Dashwood M R, Loesch A (2007) Surgical damage of the saphenous vein and graft patency. J Thorac Cardiovasc Surg 133: 274-275. Dashwood M, Anand R, Loesch A, Souza D (2004) Surgical Trauma and Vein Graft Failure: Further Evidence for a Role of ET-1 in Graft Occlusion. J Cardiovasc Pharmacol 44: S16-S19. Furchgott, R. F. and J. V. Zawadzki, The obligatory role of endothelial cells in the relaxation of arterial smooth muscle by acetylcholine. Nature, 1980. 288: p. 373-376. Khakh, B. S., and North, R. A. (2006) P2X receptors as cell-surface ATP sensors in health and disease. Nature 442, 527-532. Cario-Toumaniantz, C., Loirand, G., Ladoux, A., and Pacaud, P. (1998) P2X7 receptor activation-induced contraction and lysis in human saphenous vein smooth muscle. Circ Res 83, 196-203. Donnelly-Roberts, D. L., Namovic, M. T., Faltynek, C. R., and Jarvis, M. F. (2004) Mitogen-activated protein kinase and caspase signaling pathways are required for P2X7 receptor (P2X7R)-induced pore formation in human THP-1 cells. J Pharmacol Exp Ther 308, 1053-1061. Monahan et al., FASEB 23:557-564, 2009. Pfeiffer, Z. A., Aga, M., Prabhu, U., Watters, J. J., Hall, D. J., and Bertics, P. J. (2004) The nucleotide receptor P2X7 mediates actin reorganization and membrane blebbing in RAW 264.7 macrophages via p38 MAP kinase and Rho. J Leukoc Biol 75, 1173-1182. Peng, W., Cotrina, M. L., Han, X., Yu, H., Bekar, L., Blum, L., Takano, T., Tian, G. F., Goldman, S. A., and Nedergaard, M. (2009) Systemic administration of an antagonist of the ATP-sensitive receptor P2X 7 improves recovery after spinal cord injury. Proc Natl Acad Sci USA 106, 12489-12493. Seal & Panitch, Biomacromolecules 4(6): 1572-82 (2003). PCT/US2007/16246 PCT/US2008/72525 Alcaraz et al., Bioorganic & Medicinal Chemistry Letters 13(22): 4043-4046 (2003) Carroll et al., Purinergic Signalling 5(1): 63-73 (2009) U.S. Pat. No. 7,709,469 U.S. Pat. No. 6,812,226 U.S. Pat. No. 7,741,493 U.S. Pat. No. 7,718,693 U.S. Pat. No. 7,326,792 U.S. Patent Publication 2010/0292295 U.S. Patent Publication 2010/0292224 U.S. Patent Publication 2010/0286390 U.S. Patent Publication 2010/0210705 U.S. Patent Publication 2010/0168171 U.S. Patent Publication 2010/0160389 U.S. Patent Publication 2010/0160388 U.S. Patent Publication 2010/0160387 U.S. Patent Publication 2010/0160384 U.S. Patent Publication 2010/0160373 U.S. Patent Publication 2010/0144829 U.S. Patent Publication 2010/0144727 U.S. Patent Publication 2010/0105068 U.S. Patent Publication 2010/0075968 U.S. Patent Publication 2010/0056595 U.S. Patent Publication 2010/0036101 U.S. Patent Publication 2009/0264501 U.S. Patent Publication 2009/0215727 U.S. Patent Publication 2009/0197928 U.S. Patent Publication 2009/0149524 U.S. Patent Publication 2009/0005330 U.S. Patent Publication 2008/0132550 U.S. Patent Publication 2008/0009541 U.S. Patent Publication 2007/0122849 U.S. Patent Publication 2007/0082930 U.S. Patent Publication 2005/0054013 U.S. Patent Publication 2005/0026916 U.S. Patent Publication 2002/0182646 | The leading cause of graft failure is the subsequent development of intimal hyperplasia, which represents a response to injury that is thought to involve smooth muscle proliferation, migration, phenotypic modulation, and extracellular matrix (ECM) deposition. Surgical techniques typically employed for vein harvest—stretching the vein, placing the vein in low pH, solutions, and the use of toxic surgical skin markers—are shown here to cause injury. The invention therefore provides for non-toxic surgical markers than also protect against stretch-induced loss of functional viability, along with other additives. Devices and compositions for reducing physical stress or protecting from the effects flowing therefrom, also are provided. | 0 |
RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 12/399,230, filed 6 Mar. 2009, entitled “Hanging Chute,” which is a continuation of U.S. patent application Ser. No. 11/668,335, filed 29 Jan. 2007, entitled “Hanging Chute,” which has been issued as U.S. Pat. No. 7,513,352. The above applications are incorporated by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the field of mining and material handling, and in particular to a chute for conveying mining materials.
2. Description of Related Art
From high rises to highways, drainage pipes to railroad beds, houses to hospitals, the aggregate, cement, concrete and mining material industries provide the glue and buildings blocks of modern life. For example, we use them to build our schools and commercial buildings because concrete and aggregate products will not burn. Also, water purification systems are made from concrete products because they are clean and easy to maintain. At the same time, these products are natural and reusable. Sand, crushed stone, gravel, cement, and water in all of their combinations and forms are natural resources and part of the earth. Low in cost, natural aggregates are a major contributor to and an indicator of the economic well being of a nation.
It is important to note that more than three billion tons of aggregate were produced in the United States (U.S.) in 2004 with a value of approximately $16 billion, contributing $37.5 billion to the U.S. Gross Domestic Product. Every $1 million in aggregate sales creates 19.5 jobs, and every dollar of industry output returns $1.58 to the economy. Also, about ten tons of aggregate per person are used annually in the U.S. Every mile of interstate highway uses 38,000 tons of aggregate and about 400 tons of aggregate is used to build the average home.
Mining materials also have an amazing variety of other uses. Imagine our lives without wallboard and roofing tiles or without paint, glass, plastics, and medicine. When ground into powder, limestone is used as an important mineral supplement in agriculture, medicine and household products. Mining materials are also being used more and more to protect our environment. Soil erosion-control programs, water purification, and reduction of sulfur dioxide emissions generated by electric power plants are just a few examples of such uses.
Even after these materials are extracted and utilized, the job still is not finished. For example, what was once the bottom of a rock quarry can become a golf course, school, theme park or shopping center. Furthermore, these natural mining materials are a major basic raw material used by construction, agriculture, and industries. Mining industries employ complex chemical and metallurgical processes.
Carefully managing these valuable and limited resources is essential for the environment, economy, and future of a nation. For this reason, mining material producers, industry service providers and equipment suppliers are continually procuring ideas and innovations to help with the industry.
The mining industry utilizes a variety of methods to excavate such natural resources. These methods are dependent upon the geologic characteristics of the natural deposit. Open-pit mining and quarrying are commonly used. Other deposits require mining underground. Sand and gravel deposits above the water table are excavated with bulldozers, front-end loaders, tractor scrapers, and draglines. Deposits below the water table, including stream and lakebed deposits, may be excavated with draglines or from barges using hydraulic or ladder dredges. Mining and quarrying stone generally require drilling and blasting, after which the rock is then transported to a processing facility on trucks and conveyors.
Processing plants are generally constructed on the site of extraction. Processing of mined or quarried rock requires primary and possible secondary crushing, depending on the sizes of mining material needed. After crushing, the crushed stone, sand and gravel usually are sorted to size, moved by conveyors to bins or stockpiled.
Chutes associated with these processing steps are subjected to a great deal of wear and tear, not only by the impact and abrasion resulting from movement of the ore and other fluent material but also by the impact of other machinery or equipment. Impact and wear of the chutes will, over a period of time, result in significant deterioration. Another contributing factor to such deterioration is exposure of the chutes to the liquid components of mining materials.
One approach has been to weld liners of steel to the chutes. This is an expensive procedure requiring significant labor and hoisting machinery. Furthermore, chutes in a significant state of deterioration or chutes of certain types of materials are often not amenable to repair utilizing this approach. Use of steel or other metal liners also adds significant weight to the chute, which is undesirable.
Attempts have been made to coat chutes with plastic or elastomer materials; that is, a bond is created between the plastic and the chute material over the entire extent. This causes difficulties due to the difference in coefficients of expansion of the two materials. Furthermore, any break in the coating will result in the underlying chute material coming into contact with liquid or other types of processing materials, thus causing corrosive or abrasive wear that will over time significantly deteriorate the quality and strength of the chute. This same result can, of course, occur even when steel liners or plates are affixed to chutes. And it almost goes without saying that the various attempts to protect in these processing plant chutes result in permanent alteration of the chutes. That is, the various liners and coatings become integral parts of the chutes, rendering further repair even more difficult, if not impossible.
U.S. Pat. No. 5,035,313, “Telescopic chute for a mixer truck,” issued Jul. 30, 1991 to Smith discloses a dispensing chute for attachment to a mixer truck comprising a plurality of telescopically mounted sections. The chute sections are in the form of interlocking open top curved metal sections having replaceable plastic liners affixed to interior portions of the metal sections.
U.S. Pat. No. 4,054,194 “Discharge chute for concrete mix,” issued Oct. 18, 1977 to Davis discloses a conveying chute for freshly mixed concrete made with cross members at each end of the chute connected by two outer longitudinal members on opposite sides of the chute. It also has a bottom member between the cross members along the bottom of the chute. The chute includes a metal mesh reinforced polyurethane liner fastened to the cross members at each end of the chute by sets of bolts and nuts.
Existing concrete chutes used with aggregate transport vehicles or with stationary processing mining material and mixing plants, are typically made of steel with and without reinforcing members. Such chutes are heavy and difficult to manipulate. Also, chutes associated with aggregate transport are subject to a great deal of wear and tear not only by the impact and abrasion resulting from the movement of the aggregate or other fluent materials, but also by the impact of other machinery and equipment. In response to such conditions, chutes have been developed that have a liner attached in the chute to ameliorate the abrasion and impact conditions experienced by the chute during their use.
These devices typically will bolt or otherwise fasten the liner to the chute in order to maintain the liner within the chute throughout the chute's operational positions. Problems continue to exist; however, in that the fasteners wear as the ore moves over the fasteners, and the fasteners are subject to corrosion and rust either from the ores' chemical composition or from the process fluids.
Other liners have been laminated to the chute in order to avoid the wear and corrosion of hardware described above. However, the laminated liners, experience different thermal expansion characteristics which causes stress and cracks that allows aggregate and other fluent materials to attack the chute. Also, laminated liners cannot be easily replaced or repaired and typically a new chute is required. Other chutes composed of materials other than metal and with or without liners have also been used. However, such chutes are not as resilient to the conditions they are exposed to and further cracking and breaking requires replacement of the entire chute.
A need exists for a lightweight but strong chute for use with processing plants in the mining material industry. Elastomers such as rubber and urethane are better suited than other plastics, metals, or other materials, because of their resistance to abrasion, elasticity, and because of their relatively low weight. Urethane is also of special interest due to its particularly smooth surface. U.S. Pat. No. 4,362,231, “Chute for Transporting Timber,” issued Dec. 7, 1982 to Meyer utilizes polyurethane material to construct the chute.
The present invention provides a solution to these needs and other problems, and offers other advantages over the prior art.
BRIEF SUMMARY OF THE INVENTION
The present invention is related to an apparatus that solves the above-mentioned problems. In accordance with one embodiment of the invention, a chute constructed from urethane wear material within a rib cage for support is described. In particular, several ribs are dispersed throughout the length of the chute for support of the flexible urethane wear sheet. A flexible sheet has a reinforced edge with varying thicknesses to accommodate different weight loads and abrasive conditions. Furthermore, the chute has interlocking edges for ease of constructing long lengths from a series of shorter sections. These shorter sections are easier to transport to a processing plant or other site where the chute is to be installed. Another feature is that the flexible sheet is formed such that it may be installed in the rib cage in a tool less manner without need for fasteners. Preferably, the chute is easily maintainable and can incorporate wear resistant inserts such as ceramics for additional wear resistance.
Additional advantages and features of the invention will be set forth in part in the description which follows, and in part, will become apparent to those skilled in the art upon examination of the following or may be learned by practice of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a processing plant with chutes in place to transport mining material in accordance with one aspect of this invention.
FIG. 2 illustrates a side view of a hanging chute in accordance with one aspect this invention.
FIG. 3 is a perspective view of one overlapping urethane sheet in accordance with one aspect of this invention.
FIG. 4 is a bottom view of a featured urethane sheet in a relaxed flat condition accordance with one aspect of this invention.
FIGS. 5 , 6 and 7 are end views of three different embodiments of an upper ridge of the urethane sheet that fits over a top rib of a rib cage and engages a lid surface in accordance with various aspects of this invention.
FIG. 8 is a perspective view of a hanging chute incorporated into a processing plant in accordance with one aspect of this invention.
FIG. 9 illustrates a perspective view of a feed end in accordance with one aspect of this invention.
FIG. 10 illustrates another perspective view of a discharge end with a chute cap in accordance with one aspect of this invention.
Throughout the drawings, the same reference numerals indicate similar or corresponding features or functions.
DETAILED DESCRIPTION
In FIG. 1 an example of the invention, a hanging chute 100 , is shown incorporated into a processing plant 150 . It will be understood by those skilled in the art that chutes transport material from one piece of equipment in a processing plant 150 to another. It will further be understood by those skilled in the art that significant dust generation may result if chutes are not designed properly. The chutes should be large enough to avoid jamming of material and reduce fugitive material escape.
Turning now to FIG. 2 , a side view of the hanging chute 100 is shown. The hanging chute 100 has an upper ridge 120 that fits over a top rib 152 . This engagement of the upper ridge 120 with the top rib 152 ensures that material will not seep out of the chute. The hanging chute 100 also has ribs 130 that engage to a flexible sheet 124 . These ribs 130 are dispersed throughout the length of the flexible sheet 124 at various intervals to form a rib cage. It will be understood by those skilled in the art that the flexible sheet 124 may alternatively be constructed from a material or composite consisting of polyurethane, polyethylene, high density polyethylene, polypropylene, glass reinforced plastics, polyethylene terephthalate, and polyestrene. However, in the preferred embodiment of the invention, the flexible sheet 124 should be constructed from urethane. This is because urethane is flexible and lighter and therefore easier to transport and install. Furthermore, urethane is also more resistant to wear and tear that occurs from the transport of materials through chutes in the processing plant 150 . In the alternative, various forms of rubber may be used to form the flexible sheet 124 . It will be understood by those skilled in the art that rubber is often better suited for “grizzly” type chutes where large bulk material needs to be moved.
Looking again at FIG. 2 , the hanging chute 100 also has a lower ridge 122 that acts as a latching mechanism to hold flexible sheet 124 in place. Alternatively, lower ridge 122 may also be configured to act as a spacer to help shape the flexible sheet 124 . It will be understood by those skilled in the art that a mining material conduit 132 is incorporated into the hanging chute 100 to transfer material into other hanging chutes 100 or other equipment in the processing plant 150 .
FIG. 3 illustrates a perspective view of one overlapping sheet 124 in accordance with this invention. It will be understood by those skilled in the art that when fine material and lumps are mixed in a product stream, the chute depth should be at least three times the maximum lump size to avoid jamming or overflow. Furthermore, the chute should be designed so that material falls into the flat bottom 145 . The flexible sheets 124 are placed in an overlapping position to one another so as to prevent material from escaping the product stream. FIG. 3 depicts the shape taken by the flexible sheet 124 once it is installed in rib cage 130 .
A sloping bottom 144 with a flat bottom 145 and radius corner 143 is also shown. The sloping bottom 144 greatly reduces plugging of the chute by preventing material and lumps from gathering unnecessarily. It will be understood that the sloping bottom 144 can be in a U-shape form as normally found in the art or any variation thereof. The sloping bottom is adjacent to a urethane wall 154 and a point of inflection 156 . The flat bottom 145 depicted in FIG. 3 is beneficial in resisting sliding abrasion since the flowing ore is distributed over a greater surface area than in a U-shaped chute. Radius corner 143 directs flow toward the flat bottom 145 and helps resist build up of sticky materials.
Wherever possible, material flowing through the hanging chute should fall onto the sloping bottom 144 of the flexible sheets 124 to reduce dust and noise generation, absorb impact of incoming material, reduce wear and abrasion of chute surfaces, and reduce the height of material fall. Abrupt changes of direction must be avoided to reduce the possibility of material buildup, material jamming and dust generation. Having the sloping bottom 144 prevents this backflow of the mining material stream.
FIG. 4 is a bottom view of a flexible sheet 124 in accordance with one aspect of the invention. The flexible sheet 124 is constructed with rib channels 148 that engage the ribs 130 . The rib channels 148 are molded into the flexible sheet 124 during construction to plan the location of the ribs 130 . The flexible sheet 124 also shows the upper ridge 120 and lower ridge 122 . A reinforced edge 128 is shown on the flexible sheet 124 . This reinforced edge 128 also helps reduce wear and abrasion of the hanging chute 100 . The reinforced edge 128 may be reduced or increased in thickness depending on the material to be moved. For instance, if a slurry type of material needs to be moved, the reinforced edge 128 may be thinner for reduced weight. However, if large aggregate material needs to be moved, then the reinforced edge 128 may be thicker for increased reduction of wear and tear.
In FIGS. 5 , 6 , and 7 , end views of three different embodiments of an upper ridge 120 of the flexible sheet 124 that fits over a top rib 152 of a rib cage and engages a lid surface 160 . The lid surface 160 may be placed on an open side of the hanging chute 100 (see FIG. 10 ). The lid surface 160 covers the stream of material and prevents deflecting debris similar to the chute cap 138 . The lid surface 160 may be constructed from materials similar to that of the flexible sheet 124 . The flexible sheet 124 also has a lower ridge 122 that acts as a latching mechanism to hold flexible sheet 124 in place against the rib cage. In FIG. 5 , an overhanging edge 164 has been added to the upper ridge 120 such that they collectively form a channel into which the top rib 152 is placed. In FIG. 7 , a snap fit female connector 168 has been added to the upper ridge 120 that matingly fits a reciprocal male connector 172 formed along the length of the top rib 152 . Similarly, a female connector 170 has been added to lid surface 160 that matingly fits a male connector 172 . Together these connectors provide a toolless connection of the flexible sheet 124 to the ribs 130 and an optional lid surface 160 to the ribs. It will be appreciated by those skilled in the art that other forms of lid surface, upper ridge, and top rib engagement may be provided without departing from the scope and spirit of the present invention.
In alternative embodiments of the invention, a wear insert 162 (un-shown item in bottom of chute) can also be incorporated into the reinforced edge 128 for increased reduction of wear and tear. Some examples of wear inserts 162 may be ceramics, carbides, chrome iron or other high wear compounds. It will be understood by those skilled in the art that the modular nature of the chute allows strategic placement and replacement in a simplified manner.
Moreover, in preferred embodiments, the flexible sheet 124 has interlocking edges 158 that aid in connecting the flexible sheets 124 together. This makes transfer, assembly, and disassembly of the hanging chute 100 easier. It will be understood by those skilled in the art that the interlocking edges 158 utilize male and female connections, but may be as simple as overlapping joints. Replacement or repair has been difficult in the past due to the welded or bolted metal sheets that were used in the construction of the chutes. The use of interlocking edges 158 minimizes the problem of replacement and repair by reducing labor, time, and increasing safety of the laborers.
FIG. 8 is a perspective view of a hanging chute 100 incorporated into a processing plant 150 in accordance with one aspect of this invention. In a preferred embodiment of the invention, the reinforced edge 128 appears on a lower surface 166 of the hanging chute 100 . The upper ridge 120 and the lower ridge 122 are shown again in detail. Several ribs 130 engage the flexible sheet 124 at various intervals 148 (see FIG. 4 ) and secure the hanging chute to processing plant 150 and resist moving with the material flow. It will be understood by those skilled in the art that aggregate conduits 132 are shown in FIG. 8 to further demonstrate the flow of material. The reinforced edge 128 is shown at a lower surface of the hanging chute 100 . This reinforced edge 128 helps absorb heavy impact on the chute when materials drop from the conduits 132 . In most applications, the combination of the flexible sheet 124 , reinforced edge 128 , sloping bottom 144 , and the various ribs 130 are sufficient to absorb the heavy impact on the chute 100 . Alternatively, the flexible sheet 124 may have internal steel rods 163 molded into the sheet 124 to further stabilize the apparatus.
It will be understood by those skilled in the art that the mining and material handling industries move a great variation in weight and size of substances. Accordingly, the flexible sheet 124 may be thinner in zone 154 to conserve costly wear resistant material in this low wear zone. Meanwhile, the reinforced edge 128 can be constructed with a thicker cross section to accommodate higher wear rate or impact absorption. The cross sections joining these two may have a variable thickness to accomplish the proper curved corners 143 .
FIG. 9 illustrates a perspective view of the hanging chute's feed end 136 . The flexible sheet 124 is shown attached to the end rib 126 by use of fasteners 140 . The fasteners 140 are attached to fastener holes 134 on the end rib 126 . It will be understood by those skilled in the art that fasteners 140 can be nut and bolt combinations, nails, pins or any common fastener found in the art. The reinforced edge 128 is shown again on the lower surface of the hanging chute 100 . FIG. 9 illustrates feed end 136 without a chute cap 138 . Support rib structure incorporates a bolting flange on ends 126 to allow modular construction and installation of rib structure to accommodate different lengths of carrier frames.
Turning now to FIG. 10 , the discharge end 137 is shown with a chute cap 138 . The chute cap 138 is, in preferred embodiments, constructed from material similar to the flexible sheet 124 . The chute cap 138 is attached to the tail end 136 with fasteners 140 . It will be understood by those skilled in the art that the chute cap 138 can be constructed from plastics or metals. The object of the chute cap 138 is to prevent back spill and dust emission from the tail end of the hanging chute 100 . Additionally, debris may be deflected off the interior surfaces of the hanging chute 100 and thrown at an undesirable trajectory. Having a chute cap 138 prevents such occurrences. Furthermore, a snap spout 132 may be attached to the discharge end 137 with or without fasteners 140 . It will be understood by those skilled in the art that a snap spout 132 is a separate molded piece of equipment that may be cylindrical in shape.
The foregoing merely illustrates the principles of the invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements which, although not explicitly described or shown herein, embody the principles of the invention and are thus within its spirit and scope. Although the hanging chute 100 is utilized in this description with mining industries, the invention may also be utilized in various material handling industries. For example, the hanging chute 100 and all of its embodiments may be incorporated into agricultural systems to move farm produce, grains, meat, and waste. Furthermore, the hanging chute 100 may be incorporated into delivery of materials from the dock to assigned space, removing empty crates, returning crates at end for re-crating, and delivering materials back to dock for carrier loading. These and other features will be evident to one of ordinary skill in the art in view of this disclosure, and are included within the scope of the following claims. | A hanging chute with a rib cage is described. In accordance with one embodiment of the invention, a chute constructed from flexible wear material with a rib cage to reinforce the chute. In particular, several ribs are dispersed throughout the length of the flexible sheet for support. A flexible sheet has a reinforced edge with varying thicknesses to accommodate different weight loads and abrasive conditions. Furthermore, the chute has interlocking edges for ease of constructing long lengths from a series of shorter sections. These shorter sections are easier to transport to a processing plant or other site where the chute is to be installed. Preferably the chute is easily maintainable and can incorporate wear inserts for additional wear resistance. | 1 |
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of virtual machines, and more particularly to the creation of virtual machines with specific attributes.
BACKGROUND OF THE INVENTION
[0002] Virtual machines (VMs) are commonly utilized by software development teams to test new software across many Operating Systems and different software configurations without needing to use a different physical machine to create each testing environment. Use of a virtual machine instead of a physical machine for each test environment allows for increased efficiency and lower costs of running tests. Testing software on a large scale can often require the use of many virtual machines, which has lead to new methods for creating virtual machines.
SUMMARY
[0003] Embodiments of the present invention disclose a method, computer program product, and system for determining optimal pathways for creating a virtual machine (VM) with a given set of requirements. A computer receives at least one requirement for a new VM. The computer identifies an existing VM to be modified during the generation of the new VM. The computer determines at least one step necessary to create the new VM configuration from the existing VM. The computer presents at least one pathway to the new VM from the existing VM. The computer receives a selection of a presented pathway to create the new VM.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0004] FIG. 1 is a functional block diagram illustrating a data processing environment, in accordance with an embodiment of the present invention.
[0005] FIG. 2 is a flowchart depicting operational steps of a search application, executing on a computing device within the data processing environment of FIG. 1 .
[0006] FIG. 3 depicts a block diagram of components of a computing device executing a search application, in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION
[0007] The traditional method of creating a virtual machine involves installing an operating system and additional software onto a virtual system running on a host computing device. Because many virtual machines can share the same physical hardware, virtual machines can also be created by duplicating, or “cloning” existing virtual machines. This is particularly useful if an identical copy of an existing virtual machine is required.
[0008] Snapshots are used to save the state of a virtual machine at a given point in time. Snapshots capture all data, applications, settings, and the Operating System present on a virtual machine at the point in time when the snapshot is taken. Snapshots can be used to restore a virtual machine in the event that an error occurs or data becomes corrupted. Another user for a snapshot is to create a new virtual machine from a previous state of a virtual machine captured by a snapshot.
[0009] As will be appreciated by one skilled in the art, aspects of the present invention may be embodied as a system, method or computer program product. Accordingly, aspects of the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects that may all generally be referred to herein as a “circuit”, “module” or “system.” Furthermore, aspects of the present invention may take the form of a computer program product embodied in one or more computer-readable medium(s) having computer readable program code/instructions embodied thereon.
[0010] Any combination of computer-readable media may be utilized. Computer-readable media may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples (a non-exhaustive list) of a computer-readable storage medium would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer-readable storage medium may be any tangible medium that can contain, or store a program for use by or in connection with an instruction execution system, apparatus, or device.
[0011] A computer-readable signal medium may include a propagated data signal with computer-readable program code embodied therein, for example, in baseband or as part of a carrier wave. Such a propagated signal may take any of a variety of forms, including, but not limited to, electro-magnetic, optical, or any suitable combination thereof. A computer-readable signal medium may be any computer-readable medium that is not a computer-readable storage medium and that can communicate, propagate, or transport a program for use by or in connection with an instruction execution system, apparatus, or device.
[0012] Program code embodied on a computer-readable medium may be transmitted using any appropriate medium, including but not limited to wireless, wireline, optical fiber cable, RF, etc., or any suitable combination of the foregoing.
[0013] Computer program code for carrying out operations for aspects of the present invention may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. The program code may execute entirely on a user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider).
[0014] Aspects of the present invention are described below with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and/or block diagrams, and combinations of blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0015] These computer program instructions may also be stored in a computer-readable medium that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the computer-readable medium produce an article of manufacture including instructions which implement the function/act specified in the flowchart and/or block diagram block or blocks.
[0016] The computer program instructions may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer-implemented process such that the instructions which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart and/or block diagram block or blocks.
[0017] The present invention will now be described in detail with reference to the Figures. FIG. 1 is a functional block diagram illustrating a Data Processing Environment, generally designated 100 , in accordance with one embodiment of the present invention. Data processing environment 100 includes network 105 , computing device 110 , hypervisor 120 , virtual machine repository 130 , virtual machines 140 and 150 , data collection agents 145 and 155 , snapshot repository 160 , snapshot 165 , database 170 , search application 180 , and system controller 190 .
[0018] In an exemplary embodiment, hypervisor 120 , virtual machine repository 130 , virtual machines 140 and 150 , data collection agents 145 and 155 , snapshot repository 160 , snapshot 165 , database 170 , search application 180 , and system controller 190 are stored on computing device 110 . However, in other embodiments, hypervisor 120 , virtual machines 140 and 150 , snapshot 165 , database 170 , search application 180 , and system controller 190 may be stored externally and accessed through a communication network, such as network 105 . Network 105 can be, for example, a local area network (LAN), a wide area network (WAN) such as the internet, or a combination of the two, and may include wired, wireless, fiber optic or any other connection known in the art. In general, network 105 can be any combination of connections and protocols that will support communications between computing device 110 , hypervisor 120 , virtual machine repository 130 , virtual machines 140 and 150 , data collection agents 145 and 155 snapshot repository 160 , snapshot 165 , database 170 , search application 180 , and system controller 190 are stored on computing device 110 . However, in other embodiments, hypervisor 120 , virtual machines 140 and 150 , snapshot 165 , database 170 , search application 180 , and system controller 190 in accordance with a desired embodiment of the present invention.
[0019] In various embodiments of the present invention, computing device 110 is a computing device that can be a standalone device, a server, a laptop computer, a tablet computer, a netbook computer, a personal computer (PC), or a desktop computer. In another embodiment, computing device 110 represents a computing system utilizing clustered computers and components to act as a single pool of seamless resources. In general, computing device 110 can be any computing device or a combination of devices with access to network 105 , hypervisor 120 , virtual machines 140 and 150 , snapshot 165 , database 170 , search application 180 and system controller 190 and is capable of executing search application 180 . Computing device 110 may include internal and external hardware components, as depicted and described in further detail with respect to FIG. 5 .
[0020] In various embodiments of the current invention, hypervisor 120 is an emulation program that allows virtual machines to be executed on computing device 110 . Hypervisor 120 can be (a) a virtual machine monitor that runs along the host operating system, (b) a specialized host operating system having native emulation capabilities, or (c) a host operating system with a hypervisor component wherein the hypervisor component performs the emulation. In general, hypervisor 120 can be any program or software capable of emulating an environment to execute virtual machines.
[0021] In an exemplary embodiment, VM repository 130 is a computer database containing virtual machines 140 and 150 . Virtual machines 140 and 150 are virtual machines stored within VM repository 130 . Virtual machines 140 and 150 are software implemented abstractions of hardware included in computing device 110 . In general, virtual machines 140 and 150 can be utilized to emulate functions of a physical computer (e.g., execute programs). In another embodiment, virtual machines 140 and 150 are representations of virtual devices that are being implemented on computing device 110 . In one embodiment, the resources of computing device 110 (e.g., memory, central processing units (CPUs), storage devices, and I/O devices) can be partitioned for use by one or more virtual machines including virtual machines 140 and 150 .
[0022] In exemplary embodiments, data collection agents 145 and 155 are computer programs installed onto virtual machines 140 and 150 . Data collection agents 145 and 155 generate application install data and communicate collected data to database 170 . Data collection agent 145 and 155 operate by detecting an installation occurring on a virtual machine on which either data collection agent is installed e.g., 145 or 155 . In an exemplary embodiment of the present invention, data collection agents 145 and 155 will generate data such as the number of steps required to complete an installation of a software component, the total time required for the installation of a software component, and the amount of user input required during the installation of a software component upon completion of an installation process. The generated data is sent to and stored as part of database 170 .
[0023] In exemplary embodiments, snapshot repository 160 is a computer database containing all snapshots taken of virtual machines present in virtual machine repository 130 . Snapshot library 160 contains snapshot 165 . In certain embodiments, snapshot 165 includes a record of an earlier state of a virtual machine present in virtual machine repository 130 .
[0024] In general, snapshot 165 includes a record of an earlier state of a virtual machine present in virtual machine repository 130 . Snapshot 165 facilitates the operation of restoring its corresponding virtual machine to its state at the time the snapshot was created. The record comprising snapshot 165 includes a copy of all data present on the virtual machine's storage which may be an emulated version of a hard drive, solid state drive, or any other computer storage device known in the art. Snapshot 165 also includes the state of virtual machine 165 's memory, which may be an emulated version of random access memory or any other computer storage medium known in the art.
[0025] Database 170 is a computer database containing records of all present virtual machines and snapshots in virtual machine repository 130 as well as snapshot repository 160 . Database 170 receives data from data collection agents 145 , data collection agent 155 , and system controller 190 .
[0026] Search application 180 is a software program that utilizes data stored in database 170 to determine possible sequences of steps required to create a new virtual machine with a given set of attributes. In an exemplary embodiment of the present invention, the process of determining the sequence of steps required to create a new virtual machine with a given set of attributes comprises (a) receiving the requirements for a new virtual machine from a user, (b) searching through records of existing virtual machines and snapshots stored in database 170 for a record which includes similar software properties, and (c) determining the additional steps required to create a new virtual machine using an existing record as a starting point, if any.
[0027] System controller 190 is a system controller for hypervisor 120 . System controller 190 observes the behavior and actions of hypervisor 120 and sends a record of any action performed to database 170 . In an exemplary embodiment, actions recorded include (a) a virtual machine being copied to create a new virtual machine, (b) a virtual machine being deleted, (c) a snapshot being created from a virtual machine, and (d) a virtual machine being restored from a record contained in a snapshot.
[0028] FIG. 2 is a flowchart depicting operational steps of search application 180 for determining the possible sequences of steps required to create the desired virtual machine, in accordance with an embodiment of the present invention.
[0029] Search application 180 is a software program which determines all possible sequences of steps required for creating a new virtual machine with a given set of attributes and presents them to the user.
[0030] In an exemplary embodiment of the present invention, a user inputs requirements for a new virtual machine into search application 180 . Search application 180 receives requirements for a new virtual machine from a user in step 205 .
[0031] Search application 180 performs a query of database 170 to search for available virtual machines or snapshots possessing attributes required for the new virtual machine to be created in decision step 210 . These attributes can include at least one of (a) an operating system, (b) an installed software application, (c) an amount of hardware resources available to the virtual machine.
[0032] If no virtual machines or snapshots within virtual machine repository 130 or snapshot repository 160 have any of the attributes required for the new virtual machine (decision step 210 , no branch), search application 150 will recommend creating a new virtual machine without using an existing virtual machine or snapshot as a starting point, in step 215 . Once a recommendation to create a new virtual machine without the use of an existing virtual machine or snapshot is made, the new virtual machine will be created using the determined sequence of steps in step 235 .
[0033] If a virtual machines or snapshots can be used as a starting point to create the new required virtual machine (decision step 210 , yes branch), all the possible sequences of steps to create the new virtual machine using the existing virtual machines and snapshots are determined in step 220 . A sequence of steps can include one or more of (a) making a copy of a virtual machine, (b) restoring a virtual machine from a snapshot, (c) installing or uninstalling additional software onto a virtual machine, or (d) changing the amount of hardware resources available to a virtual machine.
[0034] Possible sequences of steps which can be used to create the new virtual machine are presented to the user in step 225 . In various embodiments of the current invention, additional information may be displayed along with each set of possible steps determined. Additional information can include one or more of (a) the total time required for the sequence of steps to be performed, (b) the number of steps required to complete the generation of the virtual machine, or (c) the complexity of the steps required within the sequence of steps. The complexity of a sequence of steps can be determined using one or more of (a) the number of keystrokes required to install a software component, (b) the amount of manual data input required to install additional software, or (c) the number of carriage returns required to install additional software.
[0035] Once all possible sequences of steps are determined, the user selects a presented sequence of steps to be used to build the new virtual machine, in step 230 .
[0036] The new virtual machine is created using the selected pathway, which was generated in step 220 and was selected by the user in step 230 . In an exemplary embodiment of the present invention, the user manually creates the virtual machine by following the selected sequence of steps provided. In other embodiments, search application 180 triggers the creation of the new virtual machine by an automated system. An automated system for creating a desired virtual machine can include running scripting created by search application 180 which provides program instructions allowing a configuration management application such as puppet or chef to follow the selected sequence of steps to create the new virtual machine.
[0037] FIG. 3 depicts a block diagram of components of computing device 110 in accordance with an illustrative embodiment of the present invention. It should be appreciated that FIG. 3 provides only an illustration of one implementation and does not imply any limitations with regard to the environments in which different embodiments may be implemented. Many modifications to the depicted environment may be made.
[0038] Computing device 110 includes communications fabric 302 , which provides communications between computer processor(s) 304 , memory 306 , persistent storage 308 , communications unit 310 , and input/output (I/O) interface(s) 312 . Communications fabric 302 can be implemented with any architecture designed for passing data and/or control information between processors (such as microprocessors, communications and network processors, etc.), system memory, peripheral devices, and any other hardware components within a system. For example, communications fabric 302 can be implemented with one or more buses.
[0039] Memory 306 and persistent storage 308 are computer-readable storage media. In this embodiment, memory 306 includes random access memory (RAM) 314 and cache memory 316 . In general, memory 306 can include any suitable volatile or non-volatile computer-readable storage media.
[0040] Hypervisor 120 , virtual machine repository 130 , virtual machines 140 and 150 , data collection agents 145 and 155 , snapshot repository 160 , snapshot 165 , database 170 , search application 180 , and system controller 190 are stored in persistent storage 308 for execution and/or access by one or more of the respective computer processors 304 via one or more memories of memory 306 . In this embodiment, persistent storage 308 includes a magnetic hard disk drive. Alternatively, or in addition to a magnetic hard disk drive, persistent storage 308 can include a solid state hard drive, a semiconductor storage device, read-only memory (ROM), erasable programmable read-only memory (EPROM), flash memory, or any other computer-readable storage media that is capable of storing program instructions or digital information.
[0041] The media used by persistent storage 308 may also be removable. For example, a removable hard drive may be used for persistent storage 308 . Other examples include optical and magnetic disks, thumb drives, and smart cards that are inserted into a drive for transfer onto another computer-readable storage medium that is also part of persistent storage 308 .
[0042] Communications unit 310 , in these examples, provides for communications with other data processing systems or devices, including resources of enterprise grid 112 and client devices 104 , 106 , and 108 . In these examples, communications unit 310 includes one or more network interface cards. Communications unit 310 may provide communications through the use of either or both physical and wireless communications links. Hypervisor 120 , virtual machine repository 130 , virtual machines 140 and 150 , data collection agents 145 and 155 , snapshot repository 160 , snapshot 165 , database 170 , search application 180 , and system controller 190 may be downloaded to persistent storage 308 through communications unit 310 .
[0043] I/O interface(s) 312 allows for input and output of data with other devices that may be connected to server computer 102 . For example, I/O interface 312 may provide a connection to external devices 318 such as a keyboard, keypad, a touch screen, and/or some other suitable input device. External devices 318 can also include portable computer-readable storage media such as, for example, thumb drives, portable optical or magnetic disks, and memory cards. Software and data used to practice embodiments of the present invention, e.g., search application 180 , database 170 , data collection agent 145 , and data collection agent 155 , can be stored on such portable computer-readable storage media and can be loaded onto persistent storage 308 via I/O interface(s) 312 . I/O interface(s) 312 also connects to a display 320 .
[0044] Display 320 provides a mechanism to display data to a user and may be, for example, a computer monitor.
[0045] The programs described herein are identified based upon the application for which they are implemented in a specific embodiment of the invention. However, it should be appreciated that any particular program nomenclature herein is used merely for convenience, and thus the invention should not be limited to use solely in any specific application identified and/or implied by such nomenclature.
[0046] The flowchart and block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagrams may represent a module, segment, or portion of code, which comprises one or more executable instructions for implementing the specified logical function(s). It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. It will also be noted that each block of the block diagrams and/or flowchart illustration, and combinations of blocks in the block diagrams and/or flowchart illustration, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and computer instructions. | A computer receives at least one requirement for a new VM. The computer identifies an existing VM to be modified during the generation of the new VM. The computer determines at least one step necessary to create the new VM configuration from the existing VM. The computer presents at least one pathway to the new VM from the existing VM. The computer receives a selection of a presented pathway to create the new VM. | 6 |
BACKGROUND
The present invention relates to fabrication methods and resulting structures of a field effect transistor (FET), and more specifically, to forming pillars for heat dissipation and isolation in vertical FETs (VFETs).
A FET is a three-terminal device that includes a source, drain, and gate. Generally, a FET is fabricated with the source and drain formed on the same lateral level such that current flow, which is controlled by the gate in the channel region between the source and drain regions, is horizontal. In the efforts to scale complementary metal-oxide semiconductor (CMOS) technologies to 5 nanometers and below, non-planar FET architectures such as fin-type FETs (finFETs) and vertical FETs (VFETs) have been pursued. In a finFET, the source, drain and channel regions are built as a three-dimensional fin, which serves as the body of the device. The gate electrode is wrapped over the top and sides of the fin, and the portion of the fin that is under the gate electrode functions as the channel. In a VFET, the channel is also formed in a three-dimensional fin. However, the gate in a VFET extends along and/or around the vertical sidewalls of the fin. As a result, current flow in the channel region is vertical rather than horizontal.
SUMMARY
According to an embodiment of the present invention, a method of fabricating a vertical field effect transistor (VFET) includes forming fins from a portion of a substrate. At least a first fin of the fins is associated with a first device, at least a second fin of the fins is associated with a second device, and the first fin and the second fin are adjacent fins. Alternating pillars of a first polymer and a second polymer are formed on the substrate, adjacent to and between the fins. The pillars of the second polymer are removed, except between two or more fins of a same device. The substrate pillars are formed below the pillars of the first polymer based on etching, to a specified depth, the substrate below the pillars of the second polymer that are removed. The etching creates a deep trench between the first fin and the second fin. The method also includes removing the pillars of the first polymer and any remaining ones of the pillars of the second polymer, and performing an insulator fill to fill the deep trench and gaps between the pillars of the substrate with an insulator.
According to another embodiment, a structure of a vertical field effect transistor (VFET) includes a substrate layer of a substrate material, and the substrate pillars formed from the substrate material above the substrate layer. An insulator fill is between the pillars. Fins are formed above the terminal regions. Each of the terminal regions is bordered by one of the pillars. Gate regions are formed adjacent to the fins.
BRIEF DESCRIPTION OF THE DRAWINGS
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 forgoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
FIGS. 1-15 show cross-sectional views of intermediate structures formed during the fabrication of VFET devices according to one or more embodiments, in which:
FIG. 1 is a cross-sectional view showing fin hard masks formed on a substrate;
FIG. 2 is a cross-sectional view of the intermediate structure that results from removal of the fin hard mask from non-fin regions;
FIG. 3 shows the result of fin formation and, specifically, a pair fins specific to each of two devices;
FIG. 4 is a cross-sectional view of an intermediate structure that results from deposition of a co-polymer;
FIG. 5 is the structure that results from an anneal of the structure shown in FIG. 4 ;
FIG. 6 is a cross-sectional view showing the structure of FIG. 5 with a mask formed above the second co-polymer material between fins of each device;
FIG. 7 results from a selective removal of the second co-polymer material in the structure of FIG. 6 ;
FIG. 8 is a cross-sectional view of an intermediate structure that results from removal of the mask and first and second co-polymer materials;
FIG. 9 is a cross-sectional view of an intermediate structure that includes an oxide fill;
FIG. 10 results from a recess of the oxide to the level of the pillars formed from the substrate material;
FIG. 11 is a cross-sectional view of an intermediate structure that includes a bottom spacer;
FIG. 12 is an intermediate structure that includes a conformal high-k dielectric and a gate metal;
FIG. 13 is a cross-sectional view of an intermediate structure that includes a top spacer above the gate metal;
FIG. 14 results from deposition of an oxide layer above the top spacer shown in FIG. 13 ; and
FIG. 15 is a cross-sectional view of an intermediate structure that includes epitaxial layers that replace the fin hard masks above the fins.
DETAILED DESCRIPTION
As previously noted, several non-planar FET architectures, such as finFETs and VFETs, have fin-shaped channel regions between the source and drain regions. The gate that controls the channel region is formed around or between the fins. This gate region can become hot during operation of the transistor. Heat dissipation from the gate region can be challenging when the gate is formed on an oxide, as is typically the case. This is because oxide is not an efficient heat transfer material. In addition, when transistor devices are formed adjacent to each other, proper electrical isolation of the devices is necessary. On the one hand, the decrease in pitch between devices can increase the number of devices that are fabricated. On the other hand, precise formation of a shallow trench isolation (STI) region that is sufficiently deep to provide isolation between devices becomes more challenging as the devices are formed closer to each other.
Turning now to an overview of aspects of the present invention, one or more embodiments provide fabrication methods for VFETs in which an oxide is interspersed with the substrate material. Specifically, instead of a complete trench formed in the non-fin regions as in known FETs, pillars are formed from the substrate material. These pillars act to transfer heat from the gate region. In addition, the bi-polymer structure used to form the pillars facilitates an increase in the process window for forming the trench between devices.
Turning now to a more detailed description of one or more embodiments, FIGS. 1-15 show cross-sectional views of intermediate structures formed during the fabrication of VFET devices. The cross-sectional views show one side of the fin region for explanatory purposes to detail the relevant features. It should be clear that another non-fin region is formed, similarly to the one that is detailed, on the other side of the devices shown in the figures. FIG. 1 shows fin hard masks 120 formed on a substrate 110 . The patterning of a hardmask layer into the fin hardmasks 120 , as shown, is achieved through known processes such as, for example, a reactive ion etch (ME), self-aligned double patterning (SADP), or side-wall assisted double patterning (self-aligned quadruple patterning (SAQP)) process and is not further detailed here.
The substrate 110 can include a bulk semiconductor, such as silicon, germanium, silicon germanium, silicon carbide, and those consisting essentially of III-V compound semiconductors having a composition defined by the formula Al X1 Ga X2 In X3 As Y1 P Y2 N Y3 Sb Y4 , where X1, X2, X3, Y1, Y2, Y3, and Y4 represent relative proportions, each greater than or equal to zero and X1+X2+X3+Y1+Y2+Y3+Y4=1 (1 being the total relative mole quantity). Other suitable substrates 110 include II-VI compound semiconductors having a composition Zn A1 Cd A2 Se B1 Te B2 , where A1, A2, B1, and B2 are relative proportions each greater than or equal to zero and A1+A2+B1+B2=1 (1 being a total mole quantity). The semiconductor substrate 110 can also include an organic semiconductor or a layered semiconductor such as, for example, Si/SiGe, a silicon-on-insulator or a SiGe-on-insulator. A portion or entire semiconductor substrate 110 can be amorphous, polycrystalline, or monocrystalline. In addition to the aforementioned types of semiconductor substrates 110 , the semiconductor substrate 110 can also include a hybrid oriented (HOT) semiconductor substrate in which the HOT substrate has surface regions of different crystallographic orientation. The semiconductor substrate 110 can be doped, undoped, or contain doped regions and undoped regions therein. The semiconductor substrate 110 can include regions with strain and regions without strain therein, or contain regions of tensile strain and compressive strain. In one or more embodiments, the substrate 110 can be a semiconductor-on-insulator (SOI) substrate. The substrate 110 can further include other structures (not shown) such as STI, fins, nanowires, nanosheets, resistors, capacitors, etc. The formation of the intermediate structure shown in FIG. 1 is known and not further detailed herein.
FIG. 2 is a cross-sectional view of the intermediate structure that results from removal of the fin hard mask 120 from non-fin regions. This is followed by formation of the fins 310 a , 310 b (generally 310 ), as shown in FIG. 3 . The designation of fins 310 a and fins 310 b is used to indicate that the two fins 310 a are part of one VFET, and the two fins 310 b are part of another VFET. This designation is further discussed with reference to FIG. 6 . Fin 310 formation results from etching the substrate 110 using an etch process such as a RIE process, for example, while using the fin hard masks 120 to pattern the fins 310 .
FIG. 4 is a cross-sectional view of an intermediate structure that results from deposition of a co-polymer 410 for directed self-assembly (DSA). The co-polymer 410 can be different molecular weights and ratios of polystyrene (PS)-poly(methyl methacrylate) (PMMA), for example. The molecular weight and ratio of PMMA and PS can be selected based on the desired pitch of the first co-polymer material 510 ( FIG. 5 ) and the second co-polymer material 520 ( FIG. 5 ). The deposition of the co-polymer 410 can be followed by a planarization such as a chemical mechanical planarization (CMP) to make the co-polymer 410 level with the fin hard masks 120 , as shown in FIG. 4 .
FIG. 5 is the structure that results from an anneal of the structure shown in FIG. 4 . The co-polymer 410 separates into a bi-polymer including a first co-polymer material 510 (e.g., PS, PMMA) and a second co-polymer material 520 (e.g., PMMA, PS) based on the anneal process. As FIG. 5 indicates, the first co-polymer material 510 and the second co-polymer material 520 are separated into alternating pillars.
A mask 610 is deposited and patterned to form the intermediate structure shown in FIG. 6 . The mask 610 can be a photoresist and is formed above the second co-polymer material 520 between fins 310 a of one device and between fins 310 b of another device. That is, only the second co-polymer material 520 between fins 310 of the same device needs to be protected by each mask 610 .
A selective removal of the second co-polymer material 520 is then done to form the intermediate structure shown in FIG. 7 . Only the second co-polymer material 520 under the masks 610 is retained at this stage. The etch goes through to a portion of the substrate 110 below the second co-polymer material 520 that is removed, as shown. As FIG. 7 indicates, one consequence of the selective removal is the formation of a deep trench 710 between the two devices. The width of the deep trench 710 is defined by the thickness of the second co-polymer material 520 . That is, the pitch of the second co-polymer material 520 must be less than the fin 310 pitch. Another consequence of the selective removal of the second co-polymer material 520 and substrate 110 below is the formation of pillars 720 from the substrate 110 , as shown in FIG. 7 .
Additional RIE processing is performed on the intermediate structure shown in FIG. 7 to result in the structure shown in FIG. 8 . There can be multiple etching processes that are not shown in stages. For example, the masks 610 are removed to then remove the remaining second co-polymer material 520 . The first co-polymer material 510 is also removed. This can be accomplished by a further RIE process or a wet etch process, for example.
FIG. 9 is a cross-sectional view of an intermediate structure that includes an insulation material 910 fill. The insulation material 910 can be an oxide or nitride, for example. A CMP process can be performed following deposition of the insulation material 910 to make the insulation material 910 level with the fin hard masks 120 . A recess of the insulation material 910 is then performed to result in the intermediate structure shown in FIG. 10 . The pillars 720 formed from the substrate 110 can act as an embedded endpoint during the recess to indicate the level at which the insulation material 910 should be left. The insulation material 910 in the trench 710 acts to electrically isolate the two transistor devices from each other. Based on the thickness of the second co-polymer material 520 , this isolation region can be made as narrow as needed. At this stage, known processes are performed to complete the fabrication FETs. Some of these processes are outlined with reference to FIGS. 11-15 according to one or more embodiments related to VFETs.
FIG. 11 is a cross-sectional view of an intermediate structure that includes a bottom spacer 1110 . The bottom spacer 1110 is formed by a directional deposition process and can be, for example, silicon boron carbide nitride (SiBCN). FIG. 12 shows the result of depositing and recessing a high-k dielectric 1210 and gate metal 1220 . The high-k dielectric 1210 can be hafnium dioxide (HfO2), for example, and exemplary gate metals 1220 include titanium nitride (TiN), titanium carbide (TiC), and tungsten (W). The high-k dielectric 1210 is deposited conformally. This process is followed by formation of a top spacer 1310 . The top spacer 1310 and bottom spacer 1110 can be the same material, as shown in FIG. 13 , or can be different materials according to alternate embodiments. The intermediate structure shown in FIG. 14 includes an oxide layer 1410 deposited over the top spacer 1310 . The material of this oxide layer 1410 can be different from the insulation material 910 . The deposition can be followed by a CMP process to result in the structure of FIG. 14 . In FIG. 15 , the cross-sectional view is of an intermediate structure that results from removal of the fin hard masks 120 and growth of an epitaxial layer 1510 in the place of each fin hard mask 120 . These epitaxial layers 1510 represent the drain regions of the devices according to an embodiment. According to alternate embodiments in which the drain region is formed below the fins 310 , source regions can be formed above the top spacer 1310 . Doping of the substrate 110 below the fins results in the source or drain region being formed. As FIG. 15 makes clear, one of the terminal regions (source or drain) is formed below the fins 310 while another of the terminal regions (drain or source) is formed above the fins 310 . Accordingly, current flow along the fins is vertical.
Various embodiments of the present invention are described herein with reference to the related drawings. Alternative embodiments can be devised without departing from the scope of this invention. It is noted that various connections and positional relationships (e.g., over, below, adjacent, etc.) are set forth between elements in the following description and in the drawings. These connections and/or positional relationships, unless specified otherwise, can be direct or indirect, and the present invention is not intended to be limiting in this respect. Accordingly, a coupling of entities can refer to either a direct or an indirect coupling, and a positional relationship between entities can be a direct or indirect positional relationship. As an example of an indirect positional relationship, references in the present description to forming layer “A” over layer “B” include situations in which one or more intermediate layers (e.g., layer “C”) is between layer “A” and layer “B” as long as the relevant characteristics and functionalities of layer “A” and layer “B” are not substantially changed by the intermediate layer(s).
The following definitions and abbreviations are to be used for the interpretation of the claims and the specification. As used herein, the terms “comprises,” “comprising,” “includes,” “including,” “has,” “having,” “contains” or “containing,” or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, a mixture, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but can include other elements not expressly listed or inherent to such composition, mixture, process, method, article, or apparatus.
Additionally, the term “exemplary” is used herein to mean “serving as an example, instance or illustration.” Any embodiment or design described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments or designs. The terms “at least one” and “one or more” are understood to include any integer number greater than or equal to one, i.e. one, two, three, four, etc. The terms “a plurality” are understood to include any integer number greater than or equal to two, i.e. two, three, four, five, etc. The term “connection” can include an indirect “connection” and a direct “connection.”
References in the specification to “one embodiment,” “an embodiment,” “an example embodiment,” etc., indicate that the embodiment described can include a particular feature, structure, or characteristic, but every embodiment may or may not include the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.
For purposes of the description hereinafter, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” and derivatives thereof shall relate to the described structures and methods, as oriented in the drawing figures. The terms “overlying,” “atop,” “on top,” “positioned on” or “positioned atop” mean that a first element, such as a first structure, is present on a second element, such as a second structure, wherein intervening elements such as an interface structure can be present between the first element and the second element. The term “direct contact” means that a first element, such as a first structure, and a second element, such as a second structure, are connected without any intermediary conducting, insulating or semiconductor layers at the interface of the two elements. It should be noted that the term “selective to,” such as, for example, “a first element selective to a second element,” means that the first element can be etched and the second element can act as an etch stop. The terms “about,” “substantially,” “approximately,” and variations thereof are intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application. For example, “about” can include a range of ±8% or 5%, or 2% of a given value.
For the sake of brevity, conventional techniques related to semiconductor device and integrated circuit (IC) fabrication may or may not be described in detail herein. Moreover, the various tasks and process steps described herein can be incorporated into a more comprehensive procedure or process having additional steps or functionality not described in detail herein. In particular, various steps in the manufacture of semiconductor devices and semiconductor-based ICs are well known and so, in the interest of brevity, many conventional steps will only be mentioned briefly herein or will be omitted entirely without providing the well-known process details.
By way of background, however, a more general description of the semiconductor device fabrication processes that can be utilized in implementing one or more embodiments of the present invention will now be provided. Although specific fabrication operations used in implementing one or more embodiments of the present invention can be individually known, the described combination of operations and/or resulting structures of the present invention are unique. Thus, the unique combination of the operations described in connection with the fabrication of a semiconductor device according to the present invention utilize a variety of individually known physical and chemical processes performed on a semiconductor (e.g., silicon) substrate, some of which are described in the immediately following paragraphs.
In general, the various processes used to form a micro-chip that will be packaged into an IC fall into four general categories, namely, film deposition, removal/etching, semiconductor doping and patterning/lithography. Deposition is any process that grows, coats, or otherwise transfers a material onto the wafer. Available technologies include physical vapor deposition (PVD), chemical vapor deposition (CVD), electrochemical deposition (ECD), molecular beam epitaxy (MBE) and more recently, atomic layer deposition (ALD) among others. Removal/etching is any process that removes material from the wafer. Examples include etch processes (either wet or dry), and chemical-mechanical planarization (CMP), and the like. Semiconductor doping is the modification of electrical properties by doping, for example, transistor sources and drains, generally by diffusion and/or by ion implantation. These doping processes are followed by furnace annealing or by rapid thermal annealing (RTA). Annealing serves to activate the implanted dopants. Films of both conductors (e.g., poly-silicon, aluminum, copper, etc.) and insulators (e.g., various forms of silicon dioxide, silicon nitride, etc.) are used to connect and isolate transistors and their components. Selective doping of various regions of the semiconductor substrate allows the conductivity of the substrate to be changed with the application of voltage. By creating structures of these various components, millions of transistors can be built and wired together to form the complex circuitry of a modern microelectronic device. Semiconductor lithography is the formation of three-dimensional relief images or patterns on the semiconductor substrate for subsequent transfer of the pattern to the substrate. In semiconductor lithography, the patterns are formed by a light sensitive polymer called a photo-resist. To build the complex structures that make up a transistor and the many wires that connect the millions of transistors of a circuit, lithography and etch pattern transfer steps are repeated multiple times. Each pattern being printed on the wafer is aligned to the previously formed patterns and slowly the conductors, insulators and selectively doped regions are built up to form the final device. | A method of fabricating a vertical field effect transistor includes forming fins from a portion of a substrate. At least a first fin of the fins is associated with a first device, at least a second fin of the fins is associated with a second device. The method includes forming alternating pillars of a first polymer and a second polymer on the substrate, removing the pillars of the second polymer except between two or more fins of a same device, and forming the substrate pillars below the pillars of the first polymer. The etching creates a deep trench between the first fin and the second fin. Removing the pillars of the first polymer and any remaining ones of the pillars of the second polymer is followed by performing an oxide fill to fill the deep trench and gaps between the pillars of the substrate with oxide. | 7 |
This is a division of application Ser. No. 784,930, filed Oct. 7, 1985, which is a division of application Ser. No. 660,208, filed Oct. 12, 1984, now U.S. Pat. No. 4,565,856.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to pyrithione-containing polymers. This invention also relates to the use of these polymers as biocides in paints and wood preservative products.
2. Brief Description of the Prior Art
Biocides are required in many paint and wood preservative formulations to prevent microbial degradation during shipment, storage or use. Biocides are also required in these formulated products to help protect the coated substrate from harmful microorganisms such as bacteria and fungi and the like.
Biocides used in paint products may be grouped into three major classes: preservatives, mildewcides and antifoulants. Preservatives are widely used in water-based paint systems to prevent in-can bacterial and fungal degradation during storage and shipment. They are particuarly useful in latex systems such as synthetic rubber, polyacrylate, and natural rubber latexes. Mildewcides are employed to prevent degradation of the dried paint films and underlying substrate by microorganisms. Antifoulant paints are used to prevent the growth of organisms on the hulls of both commercial and pleasure boats. The attachment of such organisms decreases the operating efficiency of the boats and increases their maintenance costs.
Mercurial-type biocides have been widely used as both preservatives and mildewcides in paints. They have excellent performance in both functions in many situations. They offer the fast kill time and can control high levels of bacterial contamination. Unfortunately, they are hazardous to handle and may present environmental problems. Thus, their use may be limited to certain applications. Various nonmercurial preservatives and mildewcides have been increasingly considered as substitutes for mercurial compounds.
A wide variety of biocides have been tried as marine antifoulants, but the marketplace has been dominated by cuprous oxide and organotin compounds for this use. Cuprous oxide has been popular because it is efficient, relatively economical, and is specified in many military antifouling paint formulations as the exclusive biocide. However, this chemical causes microporosity in the paint film, which adversely affects efficiency, and it limits the paint colors to dark reddish browns. The use of organotin compounds has been growing in recent years; however, these compounds are more expensive than cuprous oxide and also more difficult to incorporate into paint formulations. Furthermore, they do not leach out completely during use so that when ships are sandblasted the disposal of the contaminated sand poses difficulties. However, organotins yield uniform, tight films without the microporosity problems associated with cuprous oxide and may be formulated in a wide variety of bright or light colors. For these latter reasons, they are widely used on pleasure boats. Since both cuprous oxide and organotin compounds present technical or environmental problems, there is a need for new and better antifoulant paint biocides.
Biocides are also employed as wood preservative products in order to prevent the rapid deterioration of wood products that are exposed to conditions which promote microbial growth and decay. For example, utility poles, cross ties, piling timbers, freshly milled lumber and fence posts as well as wood chip piles used in pulp manufacture require the incorporation of biocides to stop or control fungal attachment. In the past, two classes of biocides have been employed as wood preservatives. One class is oil-borne preservatives (e.g. creosote and pentachlorophenol) while the second class is water-borne salts (e.g. mixtures of inorganic compounds such as copper, chromium, arsenic and zinc salts). The oil-borne preservatives have been the most widely used biocides for wood preservation. However, products treated with these mixtures may have messy oily surfaces. Also both creosote and pentachlorophenol have been objected to as being environmentally hazardous. The water-borne salts are also toxic chemicals which are dissolved in water and injected into wood products where they become bound to or within the wood. These salts have certain advantages over the oil-borne treatments. They leave a cleaner surface that may be more readily painted. Also, their water soluble characteristics provide savings in solvent costs. However, the use of chromium and arsenic salts also present environmental problems.
Because all of these commercially used wood preservatives present these problems, there is a need for new and better wood preservative biocides.
Separately, zinc and sodium pyrithione (also known as the zinc complex and the sodium salt of 1-hydroxy-2-pyridinethione, respectively) are well-known biocides in the cosmetic and hair shampoo fields. However, merely blending these biocides into paint and wood preservative formulations may result in one or more problems. Some of the major problems concern their insolubility in the other constituents of the system and their water solubility. Their paint and wood-preservative constituent insolubility may cause agglomerization of the biocide in the dried film. Their water solubility may cause leaching from the paint film or migration of the biocide in the film. These lead to uneven biocidal protection, environmental problems and reduced service life.
It has been found that these paint or wood preservative constituent insolubility and water solubility problems may be corrected by immobilizing the pyrithione moiety in selected polymers. This attachment of this moiety to these selected polymers results in the formation of a bioactive polymer.
Accordingly, it is an object of this invention to provide a class of bioactive polymers which are effective as preservatives, mildewcides and marine antifoulants in paints as well as wood preservatives.
It is also an object of this invention to provide a class of bioactive polymers which do not have the undesirable characteristics of many present commercial products such as leaching of the bioactive agent, yet, are highly toxic to the organisms of concern but have low toxicity to humans and wildlife as well as be cost competitive.
Still further objects and advantages of the present invention will be apparent from the following description.
BRIEF SUMMARY OF THE INVENTION
The present invention, therefore, is directed to bioactive polymers comprising an effective biocidal amount of moieties derived from pyrithione and having the formula (I): ##STR3## wherein R 1 , R 2 and R 3 are individually selected from hydrogen and alkyl groups having from 1 to 4 carbon atoms; and PT represents the pyrithione moiety which is defined by the following formula (II) wherein the pyrithione moiety is connected through the sulfur atom: ##STR4## wherein R 4 , R 5 , R 6 and R 7 are individually selected from hydrogen, lower alkyl group having 1 to about 8 carbon atoms, lower alkoxy group having 1 to about 8 carbon atoms, a nitro group and a halo group (e.g. F, Cl, Br and I).
These moieties of formula (I) may be made into homopolymers or incorporated into copolymers, terpolymers and the like containing moieties of at least one ethylenically unsaturated comonomer. Such polymers may have average molecular weights from about 1000 to about 1,000,000.
The present invention is also directed toward the use of these bioactive polymers as paint preservatives, mildewcides in paints, antifoulant agents in paints and as wood preservative biocides as described below.
DETAILED DESCRIPTION
The monomeric moieties of formula (I) may be made by reacting sodium pyrithione with a corresponding vinyl-containing acid chloride compound. This reaction may be carried out in the presence of water or suitable organic solvent. This reaction is illustrated by the following reaction (A) where sodium pyrithione is reacted with methacryloyl chloride: ##STR5##
Suitable vinyl-containing acid chloride reactants include methacryloyl chloride, 3,3-dimethylacryloyl chloride and crotyl chloride. The most preferred is methacryloyl chloride (R 1 =CH 3 , R 2 =R 3 =H) because of cost considerations and its good compatability in paint formulations, especially methacrylate-based.
The preferred pyrithione moiety is the unsubstituted pyrithione (R 4 =R 5 =R 6 =R 7 =H). It is widely available as sodium pyrithione.
The reaction between these vinyl acid chlorides and sodium pyrithione may be carried out with any conventional reaction conditions for this type of condensation reaction. It is preferred to employ a molar excess of the vinyl acid chloride. It is also preferred to employ water as a solvent and at temperatures from about -10° C. to about +30° C. and at atmospheric pressure. Suitable reaction times will range from about 1 to about 5 hours. The formed product will precipitate from the reaction mixture and may be recovered by any conventional solids/liquid separation technique. It is preferred to purify the precipitated product by extraction with a dilute NaOH solution. The recovered product is preferably stored at temperatures below room temperatures (e.g. -10° C. to +10° C.) to prevent decomposition. It should be noted that the reaction parameters for making the moieties of formula (I) are not critical limitations to the present invention and the present invention contemplates any and all suitable reaction conditions.
The pyrithione-containing compounds as described above may be polymerized by any of the conventionally known methods for polymerizing vinyl bond-containing monomers. These may include solvent, bulk, suspension or emulsion-type methods. Various polymerization initiators such as benzoyl peroxide, acetyl peroxide, azobis(isobutyronitrile) (also known as AIBN) or lauryl peroxide may be used. Specifically, the homopolymers and copolymers of this invention may be prepared by any of the procedures conventionally employed for making acrylate or methacrylate homopolymers or copolymers containing said monomers. It is preferred and desirable to conduct the polymerization under an inert gaseous atmosphere (e.g. nitrogen) and in an aqueous solution whereby the monomer or comonomers are suspended. However, it may be desirable in some instances to carry out the polymerization in an organic solvent such as benzene, toluene, hexane, cyclohexane, tetrahydrofuran or the like. Preferably, the monomers , and solvent are agitated and the initiator is then added.
The conditions of the reaction, such as the concentrations of the monomer and the initiator, the type of initiator, and of the solvent, vary according to the desired polymer to be formed.
The duration and temperature of the reaction depends on the desired copolymer as well as the solvent and the initiator. Preferably, reaction temperatures from about 40° C. to 100° C. are employed.
At the end of the reactions, the homopolymers or copolymers are separated from the reaction mixture and dried according to conventional techniques.
Suitable ethylenically unsaturated comonomers include the following: ethylene, propylene, butadiene, isoprene, tetrafluoroethylene, vinyl chloride, vinylidine chloride, vinylidine fluoride, styrene, indene, coumarone, vinyl acetate, vinyl alcohol, vinyl formal, acrolein, methyl vinyl ketone, vinyl pyrrolidone, maleic anhydride, acrylonitrile, vinyl ethers having the formula CH 2 ═CHOR 8 , acrylic acid, acrylamide, methacrylic esters of the formula CH 2 ═C(CH 3 )CO 2 R 8 , acrylic esters of the formula CH 2 ═CHCO 2 R 8 and cyanoacrylic esters having the formula CH 2 ═C(CN)CO 2 R 8 , wherein R 8 is a lower alkyl group having 1 to 4 carbon atoms.
Preferred copolymers of the present invention contain polymeric units or moieties of formula (I), above, as well as polymeric units or moieties derived from other methacrylates or acrylates as disclosed in preceding paragraph. In the case of copolymers, terpolymers and the like, the weight fraction of the monomers of formula (I) may be any amount which results in an effective bioactive polymer. Preferably, this weight fraction may be from about 0.01% to about 50% by weight of the total polymer.
In an alternative embodiment, it is also possible to attach the pyrithione derived moiety of formula (I) to a preformed polymer. For example, a poly(methylacrylate) could be reacted with pyrithione to add this pyrithione moiety at certain sites on the polymer chain.
It is also possible to attach other biocides (e.g. alkyl tin and quaternary ammonium moieties) to the polymer chain besides the pyrithione moiety for a more comprehensive attack on invading organisms.
The bioactive polymers of the present invention have many desirable attributes. They possess good antimicrobial activity and are not incompatible with components of conventional paint and wood preservative products. These polymers are also non-volatile, hydrolytically stable, thermally stable, and may be soluble in water and organic solvents. Furthermore, they form no undesirable colors in the paint and wood preservative formulations or in the resulting dried films. Still further, they are cost competitive with known biocides used in various paints and wood preservative products while having low or no toxicity toward humans and wildlife.
In accordance with one aspect of this invention, it has been found that the polymers containing the moiety of formula (I), above, either as homopolymers or as copolymers, terpolymers, or the like with the ethylenically unsaturated comonomers described above, may be utilized as effective paint preservatives. In practicing this aspect of the invention, an effective paint-preserving amount of one or more of these polymers is incorporated into a paint formulation. It is to be understood that the term "effective paint-preserving amount" as used in this specification and claims is intended to include any amount which will prevent or control degradation of the paint. In-can degradation of paints is often caused by gram-positive bacteria such as Bacillus cereus and Staphylococcus aureus or gram-negative bacteria such as those of the Pseudomonas or Xanthomonas classes. This degradation of the paint ingredients results in viscosity loss or generation of offensive odors.
Generally, paint preservatives are employed in aqueous-based paint systems such as latex systems. Solvent-based paints usually do not require a preservative since the nonaqueous formulation will not support bacterial growth. In-can preservatives are bactericidal and their killing action must be rapid to prevent bacterial production of certain enzymes which are actually the cause of the latex paint destruction.
When the present bioactive polymers are employed as paint preservatives, it is usually desirable to add them to the paint formulation in the same manner as other polymers are incorporated. For example, it is preferred to incorporate them as a substitute for all or a portion of non-bioactive polymers. As stated above, the actual amount of preservative used will vary with many parameters. Generally, it is preferred to employ from about 0.1 to about 5.0 pounds of the active moiety shown in formula (I) per 100 gallons of total paint formulation for this purpose.
In accordance with another aspect of this invention, it has been found that the polymers containing the moiety of formula (I), above, either as homopolymers or as copolymers, terpolymers or the like made with the ethylenically unsaturated comonomers described above, may be also employed as effective mildewcides. In practicing this aspect of the invention, an effective mildewcidal amount of one or more of these polymers is incorporated into a paint or wood preservative formulation. It is understood that the term "effective mildewcidal amount" as used in this specification and claims is intended to include any amount which will kill or control mildew-causing microorganisms. Mildew or mold causing microorganisms vary according to the exposure environment. Aureobasidium pullulans is the most commonly found species in temperate and cooler climates. Tropical and subtropical conditions favor the growth of microogranisms of the classes Aureobasidium, Aspergillus and Penciillium as well as the algae Pleurococcus virides. This effective mildewcidal amount will, of course, vary because of changes in the parameters of the environment and the substrate having these polymers incorporated therein. Generally, it is preferred to employ from about 0.1 to about 5.0 pounds of the active moiety shown in formula (I) per 100 gallons of total paint formulation for this purpose.
Paint products which may contain the biocidal compositions of the invention as preservatives and mildewcides include architectural coatings for new and and exterior paints. Other suitable paint products would include industrial finishing products such as interior and exterior maintainence coatings.
In accordance with still another aspect of the present invention, it has been found that the polymers containing the moiety of formula (I), above, either as homopolymers or as copolymers, terpolymers or the like with the ethylenically unsaturated comonomers described above, may be utilized as effective antifoulant materials. In practicing this aspect of the invention, an effective antifoulant amount of one or more of these polymers is incorporated into a hull coating formulation. It is understood that the term "effective antifouling amount" as used in this specification and claims is intended to include any amount which will prevent or control fouling on the hull. Fouling organisms include plant forms such as algae and animal forms such as those of the classes Anthropeda, Coelenterata and Mollusca. The green algae Enteromorpha is the organism most often found on the hulls of large ships.
This effective antifouling amount will vary because of changes in the parameters of the environments and the substrate in which it is applied to the hulls. Generally, it is preferred to employ from about 1 to about 50 pounds of the active moiety shown in formula (I) per 100 gallons of total paint formulation for this purpose.
In accordance with still another aspect of this invention, it has been found that polymers containing the moiety of formula (I), above, either as homopolymers or as copolymers, terpolymers and the like with the ethylenically unsaturated comonomers described above, may be utilized as effective wood preservatives. In practicing this aspect of the present invention, an effective wood-preserving amount of one or more of these polymers is incorporated into a wood product. It is to be understood that the term "effective wood-preserving amount" as used in this specification and claims is intended to include any amount which will prevent or control degradation of the wood product. Wood products not in water are subject to two forms of fungal attack, surface attack (e.g. soft rot) and internal attack (e.g. white and brown rots). Fungi imperfecti and Ascomycetes are the major cause of soft rot and the Basidiomycetes class of fungi is the major cause of internal attack. White rots attack the lignin and brown rots attack the cellulose. The commonly known dry rot is a brown rot. Also, wood products exposed to seawater may be attacked by marine organisms such as Pholads, Teredo, and Limnoria tripunctata. The effective amount of polymer employed in this application may be constantly changing because of the possible variation of many parameters. Some of these parameters may include the specific preserving polymers employed, the type of wood product to be protected, and the type of environment the wood product is exposed to. Generally, it is preferred to employ from about 1 to about 50 pounds of the active moiety shown in formula (I) per 100 gallons of total wood preservative formulation.
The biocides of the present invention may be added to the wood products by either pressure or nonpressure impregnation. If pressure impregnation is employed, either air, hydrostatic pressure and vacuum methods, or combinations thereof, may be used. If nonpressure impregnation of wood is desired, either dipping, spraying, brushing or the like may be desirable.
These bioactive polymers of the present invention may be either added directly to cellulosic materials such as the wood products in a preformed state, or the monomeric precursors including those of formula (I) may be added with suitable catalyst to promote the polymerization in-situ. In this latter case, these bioactive polymers may or may not be chemically bonded to the polysaccharide structure of the cellulosic material (e.g. wood, paper and the like). It should also be noted that paper products may be treated in either fashion to make a mildew-resistant paper, cardboard boxes or the like.
The invention is further illustrated by the following examples and comparison examples. All parts and percentages are by weight unless explicitly stated otherwise.
SYNTHESIS EXAMPLES
EXAMPLE 1
Synthesis of Pyrithione Methacrylate Homopolymer
Part A--Production of Pyrithione Methacrylate Monomer
A 2-liter beaker was charged with 158.8 g of 40% aqueous sodium pyrithione (0.5 mole) and 200 ml of water. A dropping funnel was charged with 90.4 ml of methacryloyl chloride (0.75 mole). The 2-liter beaker was cooled to +5° C. with an ice/water bath. The acid chloride was added dropwise over 90 minutes. During addition the temperature of the solution was maintained between +5° C. and +9° C. After addition was completed the solution was stirred at +6° to +7° C. for 1 hour. A solution of 20 g sodium hydroxide (0.5 mole) in 300 ml of water was added over 10 minutes. After stirring an additional 15 minutes at +8° to +10° C. the solution was brought to room temperature and stirred for 1 hour. The yellow solid that had formed was filtered and then washed with 200 ml of water. The solid was dissolved in 800 ml of methylene chloride and extracted three times with 500 ml of 4% sodium hydroxide. The methylene chloride solution was dried over 60 g of magnesium sulfate for 15 minutes, filtered, and concentrated via roto-evaporation, to give 69.18 g of a yellow solid for a 66.7% yield, with an assay of 94.1%.
The structure was confirmed by 1 H-NMR, 13 C-NMR and IR.
Purification via preparative liquid chromotography gave an analytical sample having a m.p. of 146°-147° C.
Elemental Analysis: for C 9 H 9 NSO 2 Theory: C, 55.37; H, 4.65; N, 7.17; S, 16.42. Found: C, 56.08; H, 4.80; N, 6.52; S, 14.87.
Part B--Production of Pyrithione Methacrylate Homopolymer
A 6-ml flask was charged with 0.975 g of pyrithione methacrylate (5 mmole), 0.083 g of azobis(isobutyronitrile) (AIBN) (0.5 mmole), and 4 ml of toluene. The flask was sealed and placed in an oven at 80° C. for 16 hours. After cooling to room temperature the product was diluted with 10 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 1.00 g of the desired product was isolated as a brown oil in quantitative yield. The structure was confirmed by NMR and IR. Similar results were obtained by employing either acetyl peroxide, benzoyl peroxide or lauryl peroxide as the radical initiator.
EXAMPLE 2
Synthesis of 1:9 Pyrithione Methacrylate/Methyl Methacrylate Co-Polymer by the Solution Copolymerization Method
A 6-ml flask was charged with 0.487 g of pyrithione methacrylate (2.5 mmole), 2.40 ml of methyl methacrylate (22.5 mmole), 0.083 g of AIBN (0.5 mmole), and 3 ml of toluene. The flask was sealed and placed in an oven at 80° C. for 16 hours. After cooling to room temperature the product was diluted with 10 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 2.24 g of the desired product was isolated as a yellow polymeric material for a 79.4% yield. The structure was confirmed by NMR and IR. Similar results were obtained by employing either acetyl peroxide, benzoyl peroxide, or lauryl peroxide as the radical initiator.
EXAMPLE 3
Synthesis of 1:9 Pyrithione Methacrylate/Methyl Methacrylate Copolymer by Bulk Copolymerization
A 6-ml flask was charged with 0.487 g of pyrithione methacrylate (2.5 mmole), 2.40 ml of methyl methacrylate (22.5 mmole) and a 0.083 g of AIBN (0.5 mmole). The flask was sealed and placed in an oven at 80° C. for 16 hours. After cooling to room temperature, the product was diluted with 15 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 2.41 g of the desired product was isolated as a yellow polymeric material for a 85.7% yield. The structure was confirmed by NMR and IR. Similar results were obtained by employing either acetyl peroxide, benzoyl peroxide, or lauryl peroxide as the radical initiator.
EXAMPLE 4
Synthesis of 1:49 Pyrithione Methacrylate/Methyl Methacrylate Copolymer by Solution Copolymerization
A 6-ml flask was charged with 0.097 g of pyrithione methacrylate (0.5 mmole), 2.60 ml of methyl methacrylate (24.5 mmole), 0.083 g of AIBN (0.5 mmole), and 3 ml of toluene. The flask was sealed and placed in an oven at 80° C. for 16 hours. After cooling to room temperature, the product was diluted with 10 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation, and 2.30 g of the desired product was isolated as a white polymeric material for a 90.2% yield. The structure was confirmed by NMR and IR. Similar results were obtained by employing either acetyl peroxide, benzoyl peroxide, or lauryl peroxide as the radical initiator.
EXAMPLE 5
Synthesis of 1:49 Pyrithione Methacrylate/Methyl Methacrylate Copolymer by Bulk Copolymerization
A 6-ml flask was charged with 0.097 g of pyrithione methacrylate (0.5 mmole), 2.60 ml of methyl nethacrylate (24.5 mmole) and 0.083 g of AIBN (0.5 mmole). The flask was sealed and placed in an oven at 80° C. for 16 hours. After cooling to room temperature, the product was diluted with 15 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 2.18 g of the desired product was isolated as a white polymeric material for an 85.5% yield. The structure was confirmed by NMR and IR. Similar results were obtained by employing either acetyl peroxide, benzoyl peroxide, or lauryl peroxide as the radical initiator.
EXAMPLE 6
Synthesis of 1:9 Pyrithione Methacrylate/Styrene Copolymer by Solution Copolymerization
A 6-ml flask was charged with 0.489 g of pyrithione methacrylate (2.5 mmole), 2.6 ml of methyl methacrylate (22.5 mmole) and 0.083 of AIBN (0.5 mmole), and 3 ml of toluene. The flask was sealed and placed in an oven at 80° C. for 16 hours. After cooling to room temperature, the product was diluted with 10 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 2.32 g of the desired product was isolated as a yellow polymeric material for a 79.6% yield. The structure was confirmed by NMR and IR. Similar results were obtained by employing either acetyl peroxide, benzoyl peroxide, or lauryl peroxide as the radical initiator.
EXAMPLE 7
Synthesis of 1:9 Pyrithione Methacrylate/Styrene Copolymer by Bulk Copolymerization
A 6-ml flask was charged with 0.489 g of pyrithione methacrylate (2.5 mmole), 2.6 ml of styrene (22.5 mmole) and 0.083 g of AIBN (0.5 mmole). The flask was sealed and placed in an oven at 80° C. for 16 hours. After cooling to room temperature, the product was diluted with 10 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 1.66 g of the desired product was isolated as a yellow polymeric material for a 56.9% yield. The structure was confirmed by NMR and IR. Similar results were obtained by employing either acetyl peroxide, benzoyl peroxide, or lauryl peroxide as the radical initiator.
EXAMPLE 8
Synthesis of 1:24 Pyrithione Methacrylate/Methyl Methacrylate Copolymer by Solution Polymerization
The procedure in Example 4 was repeated to make a 1:24 pyrithione methacrylate/methyl methacrylate copolymer as a white polymer solid in 71.9% yield.
EXAMPLE 9
Synthesis of 1:99 Pyrithione Methacrylate/Methyl Methacrylate Copolymer by Solution Polymerization
The procedure in Example 4 was repeated to make a 1:99 pyrithione methacrylate/methyl methacrylate copolymer as a white polymeric solid in 52.3% yield.
EXAMPLE 10
Synthesis of 1:19 Pyrithione Methacrylate/Methyl Methacrylate Copolymer by Solution Polymerization
The procedure in Example 4 was repeated to make a 1:19 pyrithione methacrylate/methyl methacrylate copolymer as a white solid in 78.8% yield.
EXAMPLE 11
Synthesis and Purification of 1:4.4 Pyrithione MethacrYlate/Methyl Methacrylate Copolymer
A 150-ml flask was charged with 60.6 g of methyl methacrylate (0.6 mole), 26.4 g of pyrithione methacrylate (0.135 mole), 3.69 g of 70% benzoyl peroxide in water (0.011 mole) and 60 ml of toluene. The flask was sealed and placed in an oven at 85° C. for 16 hours. After cooling to room temperature the product was diluted with 60 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 65.49 g of the desired product was isolated as a yellow polymeric solid for a 73.1% yield.
The crude polymer was twice precipitated from 200 ml of methylene chloride into 2000 ml of mixed hexanes. The light yellow polymer was filtered and dried under vacuum for 1 hour to give 60.32 g of purified polymer in a 69.7% overall yield.
The structure was confirmed by NMR and IR. Analysis showed that the polymer contained 13.69% pyrithione by weight.
EXAMPLE 12
Synthesis and Purification of 1:5 Pyrithione Methacrylate/(4:1) Methyl Methacrylate/Butyl Acrylate Terpolymer By Solution Polymerization
A 250-ml flask was charged with 101.0 g of methyl methacrylate (1.0 mole), 24.4 g of pyrithione methacrylate (0.125 mole), 16.1 g of butyl acrylate (0.125 mole), 6.15 g of 70% benzoyl peroxide in water (0.018 mole) and 100 ml of toluene. The flask was sealed and placed in an oven at 85° C. for 16 hours. After cooling to room temperature the product was diluted with 100 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 109.19 g of the desired product was isolated as a pale yellow polymeric solid for a 74.9% yield.
The polymer was purified according to the method of Example 11 to give 106.82 g of a pale yellow solid in a 73.7% overall yield.
The structure was confirmed by NMR and IR. Analysis showed that the polymer contained 7.30% pyrithione by weight.
EXAMPLE 13
Synthesis and Purification of 1:9 Pyrithione Methacrylate/(16:84) Methyl Methacrylate-Butyl Acrylate Terpolymer
A 150-ml flask was charged with 60.06 g of methyl methacrylate (0.6 mole), 7.32 g of pyrithione methacrylate (0.0375 mole), 14.49 g of butyl acrylate (0.1125 mole), 3.69 g of 70% benzoyl peroxide in water (0.011 mole) and 60 ml of toluene. The flask was sealed and placed in an oven at 85° C. for 16 hours. After cooling to room temperature the product was diluted with 60 ml of methylene chloride and filtered. The solution was concentrated via roto-evaporation and 56.94 g of the desired product was isolated as a pale yellow polymeric solid for a 67.4% yield.
The polymer was purified according to the method of Example 11 to give 54.85 g of a pale yellow solid in a 64.9% overall yield.
The structure was confirmed by NMR and IR. Analysis showed that the polymer contained 4.03% pyrithione by weight.
EXAMPLE 14
Synthesis of 1:49 Pyrithione Methacrylate/Methyl Methacrylate Copolymer by Emulsion Polymerization With a REDOX Initiator
The reaction was performed under a nitrogen atmosphere. A 500-ml, 3-neck flask was charged with 12 g of Triton X-200 surfactant and 188 ml of water. A solution of 3.90 g of pyrithione methacrylate (0.02 mmole) in 104.8 ml of methyl methacrylate (0.98 mole), 0.5 g of ammonium persulfate, and 2 ml of a solution of 0.3 g of ferrous sulfate heptahydrate in 200 ml of water was prepared and added to the 3-neck flask. After stirring for 30 minutes, 0.5 g of sodium metabisulfate and 3 drops of 70% t-butylhydroperoxide was added to the flask. After a 30 minute induction period, the temperature of the reaction quickly rose to 85° C. The emulsion was allowed to slowly cool to room temperature and then it was filtered through a plug of glass wool to give 288 g of a white emulsion. A 25.05-g aliquot was dried at 60° C. overnight to give 8.51 g of a white solid. The emulsion contained 33.9% by weight solids for a yield of 91.7%. The structure was confirmed by NMR and IR.
EXAMPLE 15
Synthesis of 1:19 Pyrithione Methacrylate/(1:1) Methyl Methacrylate--Butyl Acrylate Terpolymer by Emulsion Polymerization
An emulsion was prepared by adding in order with vigorous stirring, 50 ml of water, 6 g of Triton X-200 surfactant, 0.2 g of ammonium persulfate, and a solution of 4.88 g of pyrithione methacrylate (0.025 mole), 23.78 g of methyl methacrylate (0.2375 mole) and 30.44 g of butyl acrylate (0.2375 mole). After stirring an additional 10 minutes the emulsion was placed in a dropping funnel. A 300-ml, 3-neck flask was charged with 10 ml of water and 15 ml of the emulsion. The emulsion was heated and polymerization started between 78°-80° C. The contents of the dropping funnel were added over 2 hours with the temperature of the emulsion maintained between 82°-86° C. After addition was completed, the emulsion was heated an additional 1 hour at 90°-92° C. The emulsion was cooled to room temperature and stirred overnight. The emulsion was filtered through a plug of glass wool to give 135.0 g of a white emulsion. A 20.12 g aliquot was heated at 40° C. for 2 days to give 4.01 g of a white solid. The emulsion contained 19.9% by weight solids for a yield of 44.1%. The structure was confirmed by NMR and IR.
EXAMPLE 16
Synthesis of 1:49 Pyrithione Methacrylate/(1:1) Methyl Methacrylate--Butylacrylate Terpolymer by Emulsion Polymerization
An emulsion was prepared by adding in order with vigorous stirring, 50 ml of water, 6 g of Triton X-200 surfactant, 0.2 g of ammonium persulfate, and a solution of 1.95 g of pyrithione methacrylate (0.01 mole), 24.53 g of methyl methacrylate (0.245 mole) and 31.42 g of butylacrylate (0.245 mole). After stirring an additional 10 minutes the emulsion was placed in a dropping funnel. A 300-ml, 3-neck flask was charged with 10 ml of water and 15 ml of the emulsion. The emulsion was heated and polymerization started between 78°-80° C. The contents of the dropping funnel were added over 2 hours with the temperature of the emulsion maintained between 83°-86° C. After the addition was completed the emulsion was heated an additional 1 hour at 90°-91° C. The emulsion was allowed to reach room temperature and stirred overnight. The emulsion was filtered through a plug of glass wool and 134.05 g of a white emulsion was isolated. A 20.22-g aliquot was heated at 40° C. for 2 days to give a 7.78 g of a white solid. The emulsion contained 38.5% by weight solids for a yield of 86.3%. The structure was confirmed by NMR and IR analysis.
EXAMPLE 17
Synthesis of 1:49 Pyrithione Methacrylate/(3:2) Methyl Methacrylate-Butyl Acrylate Terpolymer By Emulsion Polymerization
The procedure in Example 15 was repeated to make a 1:49 pyrithione methacrylate/(3:2) methyl methacrylate/butyl acrylate terpolymer in 90.0% yield.
EXAMPLE 18
Synthesis of 1:19 Pyrithione Methacrylate/(4:1) Methyl Methacrylate-Butyl Acrylate Terpolymer
The procedure in Example 12 was repeated to make a 1:19 pyrithione methacrylate/(4:1) methyl methacrylate/butyl acrylate terpolymer as a white solid in a 67.6% yield. Analysis showed that the polymer contained 3.96% pyrithione by weight.
EXAMPLE 19
Synthesis of 3:17 Pyrithione Methacrylate/Methyl Methacrylate Copolymer
The procedure in Example 12 was repeated to make a 3:17 pyrithione methacrylate/methyl methacrylate copolymer as a pale yellow solid in a 49.7% yield. Analysis showed that the polymer contained 11.97% pyrithione by weight.
TABLE 1______________________________________ Molecular Weights of Pyrithione Containing PolymersWeight-average molecular weights weredetermined by gel permeation chromatography (HPLC) andare reported relative to poly methyl methacrylate. Weight AverageExample Molecular Weight______________________________________ 1 2,000 2 3,000 3 3,000 4 18,000 5 17,000 6 10,000 7 8,000 8 10,000 9 50,00010 8,00011 25,00012 30,00013 40,00014 64,00015 59,00016 82,00017 74,00018 50,00019 18,000______________________________________
EXAMPLE 20
Hydrolytic Stability of 1:24 Pyrithione Methacrylate/Methyl Methacrylate at pH of 8.5
A 1:24 pyrithione methacrylate/methyl methacrylate copolymer similar to that of Example 8 was employed. A 6-oz., flat-bottom jar with a 60 mm diameter was charged with 0.9 g of the polymer.
Five ml of methylene chloride was added to the jar to dissolve the polymer. As the methylene chloride evaporated off, a uniform polymer film was deposited on the bottom of the jar. Thirty ml of saturated aqueous sodium bicarbonate (pH=8.5) was added and the jar was capped and wrapped in foil to keep out light. Jars were then gently shaken for the desired amount of time. After an appropriate time interval the aqueous solution was filtered and the amount of sodium pyrithione and other pyrithione derivatives present in the aqueous solution was determined.
Samples were analyzed at day 1, 3, 10, 21, 42 and 84.
From day 1 to day 84 no sodium pyrithione or any derivatives of pyrithione were detected. Under the conditions of the test, no detectable hydrolysis of the pyrithione thioester occurred, and therefore there was no migration of pyrithione from the polymer system. The limit of detection of the test was 0.19% of the pyrithione originally present in the polymer.
Selected polymer films from days 1, 3, 10 and 21 were analyzed by a standard minimum inhibitory concentration (MIC) test to determine their antimicrobial activity after exposure to hydrolysis conditions. Results showed that no decrease in antimicrobial activity was observed in any of the samples tested.
EXAMPLE 21
Hydrolytic Stability of 1:19 Pyrithione Methacrylate/(4:1) Methyl Methacrylate-Butyl Acrylate Terpolymer Films at pH of 2.9
The 1:19 pyrithione methacrylate/(4:1) methyl methacrylate-butyl acrylate terpolymer prepared in Example 18 was tested for hydrolytic stability by the same method as employed in Example 20 except that 0.1N acetic acid was employed as the solvent. The results are summarized in Table 2.
EXAMPLE 22
Hydrolytic Stability of 1:19 Pyrithione Methacrylate/(4:1) Methyl Methacrylate-Butyl Acrylate Terpolymer Films at pH of 10
The 1:19 pyrithione methacrylate/(4:1) methyl methacrylate-butyl acrylate terpolymer prepared in Example 18 was tested for hydrolytic stability by the same method as employed in Example 20 except that a pH 10 buffer (prepared from sodium bicarbonate and sodium hydroxide) was employed as the solvent. The results are summarized in Table 2.
EXAMPLE 23
Hydrolytic Stability of 3:17 Pyrithione Methacrylate/Methyl Methacrylate Copolymer at pH of 2.9
The 3:17 pyrithione methacrylate/methyl methacrylate copolymer prepared in Example 19 was tested for hydrolytic stability by the same method as employed in Example 20 except that the polymer was diluted 1:3 with a 4:1 methyl methacrylate/butyl acrylate copolymer and 0.1N acetic acid was employed as the solvent. The results are summarized in Table 2.
EXAMPLE 24
Hydrolytic Stability of 3:17 Pyrithione Methacrylate/Methyl Methacrylate Copolymer at pH of 10.0
The 3:17 pyrithione methacrylate/methyl methacrylate copolymer prepared in Example 19 was tested for hydrolytic stability by the same method as employed in Example 20 except that the polymer was diluted 1:3 with a 4:1 methyl methacrylate/butyl acrylate copolymer and a pH 10 buffer (prepared from sodium bicarbonate and sodium hydroxide) was employed as the solvent. The results are summarized in Table 2, below.
TABLE 2______________________________________HYDROLYTIC STABILITY OF PYRITHIONEMETHACRYLATE CONTAINING POLYMERSResults are reported on the percent of pyrithionehydrolyzed relative to that originally present in thepolymer.Days pH 2.9 pH 10.0in Polymer Polymer Polymer PolymerTest 21 22 23 24______________________________________ 1 0 0 0 0 7 0 0 0 014 0.23% 0 0 028 0.34% 0.08% 0 056 0.68% 0.34% 0.08% 0.08%______________________________________
The limit of detection of the test is 0.08% of the pyrithione present in the polymer. The results show that even under conditions of extreme pH values, outside the range that the polymer would expect to encounter under normal environmental condition, only minimal hydrolysis occurs after 8 weeks. Thus, the pyrithione containing polymers have been shown to be stable to hydrolysis under a wide range of pH's.
Fungal and Algal Repellency Test of Polymers
The bioactive copolymers made by Examples 2 and 4 were tested for fungal and algal repellency. Microscope slides were used as the substrates in both cases. One half of each slide was coated on one side with a film of polymer containing the active agent to be tested. The total slide was exposed to the challenge of either fungi or algae with the expectation that the half of the slide containing the active agent would prevent growth of the challenging organism, while the untreated half would not.
In the fungal test, the slide was placed on the surface of an agar plate which had been seeded with fungi. After incubation for about 14 days, the slide was examined for extent of growth or lack thereof on the treated surface of the slide. Since leaching of the active agent would create an undesirable zone-of-inhibition outside the perimeter of the treated surface of the slide, no growth on the treated surface along with a small or no zone of inhibition was the desired result. The results of this fungal repellency test are shown in Table 3, below. The results show that both the pyrithione-containing polymers of Examples 2 and 4 control the growth of A. niger as compared to the control (untreated) surface with minimal or no zones of inhibition in the agar. The latter means the polymers did not leach into the agar. In comparison, the poly methyl methacrylate employed as a negative control allowed moderate growth of the fungus on the treated surface.
In the algal test, the slide was immersed in a nutrient broth which had been inoculated with the algae Pleurochloris pyrenoidosa. After an incubation for 30 days (under light) and a water rinse, the slide was examined microscopically and the extent of algal attachment was noted. Total lack of attachment on the treated surface was the desired result. Additional information was obtained by comparing the extent of growth of algae throughout the broth. Significant leaching of the active agent from the treated surface would inhibit growth in the broth as well as on the treated surface. The results of the algal repellancy test are shown in Table 4, below. The results show that the two pyrithione-containing polymers of Example 2 and 4 prevent algal attachment to the treated surfaces as compared to control (untreated) surfaces. Poly methyl methacrylate allowed moderate attachment. In all three cases, little or no undesirable leaching occurred into the broth.
TABLE 3______________________________________Fungal (Aspergillus Niger) Repellancy Test ZONE OF GROWTH.sup.1 INHIBITION.sup.2Sample Control Treated OnPolymer Films Surface Surface Agar______________________________________1:19 Pyrithione 2 0 1Methacrylate/MethylMethacrylatefrom Example 21:49 Pyrithione 4 1 0Methacrylate/MethylMethacrylatefrom Example 4Poly Methyl 4 2 0Methacrylate______________________________________ Key for Growth/zone of inhibition 0 no growth/zone of inhibition 1 slight growth/zone of inhibition 2 moderate growth/zone of inhibition 3 heavy growth/zone of inhibition 4 very heavy growth/zone of inhibition .sup.1 By microscopic examination of the sparse growth over the surface o the coated and uncoated portions of the slides. .sup.2 Zoneof-Inhibition: determined in the agar by direct observation.
TABLE 4______________________________________Algal (Pleurochloris pyrenoidosa) Repellency Test Control TreatedSample Surface Surface Broth______________________________________1:19 Pyrithione 2 0 2Methacrylate/MethylMethacrylate fromExample 21:49 Pyrithione 4 0 4Methacrylate/MethylMethacrylate fromExample 4Poly Methyl Methacrylate 4 2 4______________________________________ Key: 0 no attachment/growth in broth 1 slight attachment/growth in broth 2 moderate attachment/growth in broth 3 heavy attachment/growth in broth 4 very heavy attachment/growth in broth
PAINT APPLICATION EXAMPLES
EXAMPLE 25
Prototype Antifoulant Marine Paints (A-D)
The following antifoulant paint formulation was prepared. All numbers are in percent by weight. The ingredients were added in order with 2-3 minutes of stirring between each addition and 30 minutes of stirring after the paint was formulated. In making paints containing 0.74% and 0.37% pyrithione, an additional 25 parts of methylene chloride was added to obtain solubility of the polymer and this solvent was evaporated off during the final stirring.
______________________________________Formulation: 36.7 xylene(by weight) 19.0 pyrithione-containing polymer 32.8 zinc oxide 10.2 ferric oxide 0.6 silica 0.7 bentonite 100.0______________________________________
Paint A contains a 1:9 pyrithione methacrylate/methyl methacrylate copolymer (3.7% pyrithione dry weight) made by a method similar to the method described in Example 2.
Paint B contains a 1:49 pyrithione methacrylate/methyl methacrylate copolymer (0.74% pyrithione dry weight) made by a method similar to the method described in Example 4.
Paint C contains a 1:99 pyrithione methacrylate/methyl methacrylate copolymer (0.37% pyrithione dry weight) made by a method similar to the method described in Example 9.
Comparison Paints D-H--Commercial Marine Antifoulant Paints
The following commercial marine antifoulant coatings were tested:
______________________________________Paint Name Biocide______________________________________D Tri-Lux Antifouling Paint.sup.1 Tributyltin FluorideE Tri-Lux Antifouling Paint.sup.1 Bis(Tributyltin Oxide)F Woolsey Vine Last Anti- Cuprous Oxide fouling Paint.sup.2G Woolsey Super Vine Last Cuprous Oxide Antifouling Paint.sup.2 and Tributyltin FluorideH Woolsey Antifouling Boot Tributyltin Top Paint.sup.2 Resinate______________________________________ .sup.1 International Paint Company, Inc., New York, NY .sup.2 Woolsey Marine Division of Metropolitan Greetings, Inc., Brooklyn, NY.
These paints were tested for fungal and algal repellency. The results of that testing are given in Tables 5 and 6, below. Those results in Table 5 show that the paints made from pyrithione-containing polymers are effective in controlling the growth of A. niger with minimal zones of inhibition. Most commercial marine paints are effective against A. niger, but have undesirably relatively large zones of inhibition which indicate excessive leaching of the bioactive agent. The results in Table 6 show that the paints containing pyrithione are effective in containing attachment of algae to the painted (treated) surface and they are equal in performance to commercial paint products containing higher amounts of copper- or tin-containing biocides.
TABLE 5______________________________________Fungal Repellency TestInhibition of Growth of Aspergillus nigerby Paint Films ZONE-OF-.sup.2 GROWTH.sup.1 INHIBITION % Biocide Control Treated InSample by Weight Surface Surface Agar______________________________________PrototypePaintsA 3.7 2 0 1 PyrithioneB 0.74 2 0 1 PyrithioneC 0.37 2 0 0 PyrithioneCommercialPaintsD 5.25 Sn 1 0 4E 6.1 Sn 4 0 3F 42 Cu 4 4 0G 33 Cu/ 4 0 1 0.4 SnH 3.2 Sn 2 0 3______________________________________ Key for Table 5 0 No Growth/zoneof-inhibition 1 Slight Growth/zoneof-inhibition 2 Moderate Growth/zoneof-inhibition 3 Heavy Growth/zoneof-inhibition 4 Very Heavy Growth/zoneof-inhibition .sup.1 By microscopic examination of the sparse growth over the surface o the coated and uncoated portions of the slides. .sup.2 Zoneof-Inhibition: determined in the agar by direct observation.
TABLE 6______________________________________Algal Repellency Test Biocides Control TreatedSample by Weight Surface Surface Broth______________________________________PrototypePaintsA 3.7 Pyrithione 4 0 1C 0.37 Pyrithione 4 0 4CommercialPaintsD 5.25 Sn 2 0 1E 6.1 Sn 0 0 4F 42 Cu 2 0 4G 33 Cu/0.4 Sn 2 0 2H 3.2 Sn 0 0 4______________________________________ Key for Table 6 0 No Attachment/Growth 1 Slight Attachment/Growth 2 Moderate Attachment/Growth 3 Heavy Attachment/Growth 4 Very Heavy Attachment/Growth
EXAMPLE 26
Prototype Solvent-Based Paints I-M
The following paint formulation was used. Numbers are in percent by weight. The ingredients were added in order with 2-3 minutes of stirring between each addition and 30 minutes of stirring after the paint was formulated. When preparing the paints containing 0.74% and 0.37% pyrithione, an additional 25 parts of methylene chloride was added to obtain solubility of the polymer and this solvent was evaporated off during the final stirring.
______________________________________Formulation: 36.7 toluene(percent by weight) 19.0 polymer 43.0 titanium dioxide 0.6 silica 0.7 bentonite 100.0______________________________________
Paint I contains a 1:9 pyrithione methacrylate/methyl methacrylate polymer made by a method similar to the method described in Example 2.
Paint J contains a 1:24 pyrithione methacrylate/methyl methacrylate polymer made by a method similar to the method described in Example 8.
Paint K contains a 1:49 pyrithione methacrylate/methyl methacrylate polymer made by a method similar to the method described in Example 4.
Paint L contains a 1:99 pyrithione methacrylate/methyl methacrylate polymer made by a method similar to the method described in Example 9.
EXAMPLE 27
Prototype Water-Borne Paints (M-P)
The following paint formulation was used. Numbers are in grams. To the latex emulsion was added the surfactant, followed by a mixture of the combined solids added in several aliquots over 2 minutes. After addition the latex was stirred for 30 minutes.
______________________________________Formulation: 46.0 polymer emulsion, 20% solidsparts (by weight) 0.95 "Triton-X-200" surfactant.sup.3 2.12 hydroxyethyl cellulose 28.75 titanium dioxide 18.77 talc______________________________________ .sup.3 Made by Rohm and Haas of Philadelphia, PA.
Paint M contains 5:47.5:47.5 pyrithione methacrylate/ methyl methacrylate/butyl acrylate terpolymer made by a method similar to the method described in Example 15.
Paint N contains 2:49:49 pyrithione methacrylate/methyl methacrylate/butyl acrylate terpolymer made by a method similar to the method described in Example 16.
Paint O contains 2:58.8:39.2 pyrithione methacrylate/methyl methacrylate/butyl acrylate terpolymer made by a method similar to the method described in Example 17.
Comparison Paint P contains 6:4 methyl methacrylate/butyl acrylate copolymer.
Comparison Paints (Q-T)--Commercial Paints
The following commercial paints were purchased for testing.
______________________________________Paint Name Biocide______________________________________Q Evans Best Gloss Latex Tetrachloro- House and Trim.sup.4 isophthalo- nitrile (TCIN)R Evans Latex Enamel NONE Patio and Deck.sup.4S Sherwin-Williams Wall and NONE Trim Interior Flat Latex.sup.5T Magicolor's Finest NONE Latex Semigloss Interior.sup.6______________________________________ .sup.4 Evans Products Company, Roanoke, VA. .sup.5 SherwinWilliams Company, Cleveland, OH .sup.6 Magicolor Paint Company, Wheeling, IL.
Paint Midewcide Tests
The test procedure was followed exactly from the following published procedure
R. A. Zabel and W. E. Horner, Journal of Coatings Technology, 53, 33-37, (1981), except that the organism Aureobasidium pullulans M30-4 was used, isolated from mildewed exterior latex paint. Duplicates were run in each case. Two separate tests were run for slightly different time periods. (See Tables 7 and 8).
The results show that pyrithione containing paints are effective in controlling mildew growth on paint surfaces and in all cases exceed the performance of a commercial paint containing TCIN. Control paints not containing a biocide for mildew control are prone to heavy mildew growth within a 30-day period.
TABLE 7______________________________________Paint Mildewcide Test/Prototype and Commercial Paints% Biocide Growth on Paint SurfacePaint (Dry Weight) 30 Days 44 Days______________________________________I 3.7 Pyrithione 1,1 1,1J 1.5 Pyrithione 1,1 1,1K 0.74 Pyrithione 1,1 1,1L 0.37 Pyrithione 1,2 1,2M 0.93 Pyrithione 1,1 1,1N 0.37 Pyrithione 1,2 2,4O 0.93 Pyrithione 2,2 2,2S -- 4,4 4,4T -- 4,4 4,3______________________________________ Key for Table 7 1 No stain 2 Lightly stained at bottom or a few light spots 3 Heavily stained 4 Uniformly stained
TABLE 8______________________________________Paint Mildewcide Test/Prototype and Commercial Paints% Biocide Growth on Paint SurfacePaint (Dry Weight) 28 Days 42 Days______________________________________J 1.5 Pyrithione 1,1 1,1M 0.93 Pyrithione 1,1 1,1P -- 4,4 4,4Q 0.25 TCIN 2,3 2,3R -- 3,4 3,4S -- 3,4 4,--______________________________________ Key for Table 8 1 No stain 2 Lightly stained at bottom or a few light spots 3 Heavily stained at bottom 4 Uniformly stained
EXAMPLE 28
Prototype Solvent-Based Paints (U-Z)
The following paint formulations were prepared. Numbers are in grams. The ingredients were added in order with 2-3 minutes of stirring between each addition and 30 minutes of stirring after each paint was formulated.
______________________________________Formulation: 18.35 toluene 8.5 polymer 21.5 titanium dioxide 0.3 silica 0.35 bentonite______________________________________
The polymers employed in the paint formulations were mixtures of a 80:20 methyl methacrylate/butyl acrylate copolymer (MMA/BA) and a pyrithione methacrylate/methyl methacrylate/butyl acrylate terpolymer (PTMA/MMA/BA) containing 7.3% pyritihione by weight*. The ratios of these polymers employed in each Paint formulation (U-Z) are shown below.
______________________________________Polymer Ingredients PT MA/MMA/BA* MMA/BA*Paint (Weight) (Weight)______________________________________U 7.64 1.86V 2.30 6.20W 0.77 7.73X 0.23 8.27Y 0.08 8.42Z 0.00 8.50______________________________________ *Made by a method similar to that described in Example 12.
These paint formulations (U-Z) along with paint Q were tested by a method of Zabel and Horner for mildewcide activity as mentioned above. The results of this testing are given in Table 9, below. These results show that the paints containing the pyrithione biocide at extremely low levels is effective in controlling the growth of mildew on paint surfaces. Also, the pyrithione-containing paints exceed the performance of the commercial paint mildewcide TCIN even at 1/25 of the concentration of TCIN.
TABLE 9______________________________________Paint Mildewcide Test/Prototype and Commercial Paints% Biocide Growth on Paint SurfacePaint (Dry Weight) 4 Weeks 6 Weeks______________________________________U 1.0 Pyrithione 1 1V 0.3 Pyrithione 1 1W 0.1 Pyrithione 2 2X 0.03 Pyrithione 2 2Y 0.01 Pyrithione 2 2Z None 4 4Q 0.25 TCIN 3 3______________________________________ Key for Table 9: 1 No stain 2 Lightly stained at bottom or a few light spots 3 Heavily stained at bottom 4 Uniformly stained
WOOD PRESERVATION TESTING
Wood preservatives are needed to prevent the rapid deterioration of wood products that are exposed to conditions which promote microbial growth and decay. Most wood preservatives are used to extend the useful life of exterior-exposured products by keeping the structural strength of the end-product from falling below usable levels. The ability to impart water-repellency is also considered important in marine applications. Current products suffer certain disadvantages such as environmental migration of the biocide and, toxicity when involving consumer contact. The present invention overcomes such migration problems by chemically bonding the desired bioactive agent to the polymer. This will also decrease any undesirable environmental effects.
This aspect of the present invention extends the utility of the above described antimicrobial polymers to the wood preservation area. Two general techniques are shown. In one, a solution of the polymer was applied to the wood directly. In the second, a solution of the corresponding monomers and a radical initiator was applied to the wood, followed by in-situ polymerization. Examples of both types of application with pyrithione methacrylate homopolymer and pyrithione methacrylate/methyl methacrylate copolymer are included. In examples of in-situ polymerization there exists the possibility of forming graft copolymers between the pyrithione-containing polymer and the polysaccharides structure of the wood. Evidence for the formation of the graft copolymer would be the inability to leach the polymer away from the wood employing organic solvents. This evidence was obtained. See Tables 10, Examples 32, 33, 37, 38, 41, C-4 and C-5.
EXAMPLE 29
Bulk In-Situ Copolymerization
Eight 1 1/16 "×1 1/16"×1/4" pine wood blocks weighing a total of 13.13 g were placed in a dish and a 5-6 mm Hg vacuum was applied for 30 min. A solution was prepared containing 6.0 g of pyrithione methacrylate (0.03 mole), 72.0 g of methyl methacrylate (0.72 mole), and 1.23 g of azobisisobutyronitrile (0.0075 mole). While still under vacuum the solution was added to the dish and the wood blocks were submerged in the monomer solution. After soaking for 30 minutes the wood blocks were removed from the monomer solution, excess monomer was wiped off and the blocks were heated at 75° C. for 16 hours. After cooling to room temperature the blocks weighed 25.49 g. The polymer was distributed throughout the wood chip.
EXAMPLE 30
Solution In-Situ Polymerization
Eight 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 13.11 g were treated in the same manner as Example 29 except the monomer solution was a 1.50 g pyrithione methacrylate (0.0077 mole), 18.0 g methyl (0.18 mole) methacrylate, 0.31 g of AIBN (0.00185 mole), and 78 ml of toluene. The treated blocks weighed 15.28 g after polymerization.
EXAMPLE 31
Polymer Treated Wood Blocks
Four 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 8.55 g were treated in the same manner as Example 29 except that a polymer solution prepared from 20 g of the polymer from example 10 dissolved in 80 ml of toluene was employed instead of the monomer solution. After the wood preservation treatment the wood blocks were allowed to air-dry for 48 hours. The treated blocks weighed 11.54 g.
EXAMPLE 32
Methylene Chloride Wash of Treated Wood Blocks
Four wood blocks weighing a total of 13.42 from Example 29 were placed in 300 ml of methylene chloride and stirred for 1 hour. The methylene chloride solution was removed and a fresh 300 ml of methylene chloride was added and stirring was continued. The solvent was replaced three times with fresh methylene chloride after an additional 1 hour, then after 2 more hours, and then another 2 more hours of stirring. The wood blocks were removed from the solvent and air-dried for 24 hours. The wood blocks then weighed 7.86 g.
EXAMPLE 33
Methylene Chloride Wash of Treated Wood Blocks
Four wood blocks weighing a total of 7.25 g from Example 30 were washed with methylene chloride by the same procedure as Example 32. The wood blocks then weighed 6.54 g after drying for 24 hours.
The procedures outlined above in Examples 32 and 33 solubilize and remove any polymer that was formed in the wood. The procedure should not remove any graft copolymers that formed during the polymerization. Thus, the increase in the total weight of the wood blocks over their original weight prior to any treatment is attributed to the formation of a graft copolymer between the pyrithione methacrylate and/or methyl methacrylate and the polysaccharides of the wood. These increases are shown in Table 10. Other similar results are shown in Examples 37, 38, 41, C-4 and C-5.
EXAMPLE 34
Bulk In-Situ Copolymerization
Eight 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 16.22 g were treated in the same manner as Example 29 except the monomer solution was 1.5 g of pyrithione methacrylate (0.0077 mole), 94.4 g of methyl methacrylate (0.9429 mole). The treated blocks weighed a total of 31.86 g after polymerization.
EXAMPLE 35
Solution In-Situ Polymerization
Eight 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 13.80 g were treated in the same manner as Example 29 except the monomer solution was 0.38 g of pyrithione methacrylate (0.00195 mole), 23.6 g of methyl methacrylate (0.236 mole), 0.39 g of AIBN (0.0023 mole) and 96 g of toluene. The treated blocks weighed 16.31 g after polymerization.
EXAMPLE 36
Polymer Treated Wood Blocks
Four 1 1/16"×1 1/16"×1/4 pine wood blocks weighing a total of 8.37 g were treated in the same manner as Example 31 except that a polymer solution prepared from 20 g of the polymer from Example 9 dissolved in 80 ml toluene was exmployed instead of the monomer solution. After the wood preservation treatment the wood blocks were allowed to air-dry for 48 hours. The treated blocks weighed 11.54 g.
EXAMPLE 37
Methylene Chloride Wash of Treated Wood Blocks
Four wood blocks weighing a total of 15.83 g from Example 36 were washed with methylene chloride by the same procedure as Example 32. The wood blocks weighed a total of 9.26 g after drying for 24 hours.
EXAMPLE 38
Methylene Chloride Wash of Treated Wood Blocks
Four wood blocks weighing a total of 7.99 g from Example 35 were washed with methylene chloride by the same procedure as Example 32. The wood blocks weighed a total of 7.09 g after drying from 24 hours.
EXAMPLE 39
Solution In-Situ Homo-Polymerization
Eight 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 13.55 g were treated in the same manner as Example 29 except the monomer solution was 18.0 g of pyrithione methacrylate (0.09 moles), 0.84 g of AIBN (0.005 moles), and 72 g of toluene. The treated blocks weighed a total of 17.63 g after polymerization. It should be noted that bulk polymerization is not amenable with making this homopolymer because pyrithione methacrylate is a solid.
EXAMPLE 40
Polymer Treated Wood Blocks
Four 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 8.49 g were treated in the same manner as Example 31 except that a polymer solution prepared from 18 g of the polymer from Example 1B dissolved in 72 ml of toluene was employed instead of the monomer solution. After the wood preservation treatment the wood blocks were allowed to air-dry for 48 hours. The treated blocks weighed 9.63 g.
EXAMPLE 41
Methylene Chloride Wash of Treated Wood Blocks
Four wood blocks weighing 9.21 g from Example 41 were washed with methylene chloride by the same procedures as Example 34. The wood blocks weighed 7.03 g after drying.
COMPARISON 1
Bulk In-Situ Copolymerization
Eight 1 1/16"×1 1/16"×1/4" pine wood blocks weighing 12.38 g were treated in the same manner as Example 31 except the monomer solution was 100.12 g of methyl methacrylate (0.2 moles) and 1.68g of AIBN (0.01 moles). The treated blocks weighed a total of 24.70 g after polymerization.
COMPARISON 2
Solution In-Situ Polymerization
Eight 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 14.23 g were treated in the same manner as Example 31 except the monomer solution was 20.02 g of methyl methacrylate (0.2 mole), 0.33 g of AIBN (0.002 moles), and 80 g of toluene. The treated blocks weighed 17.08 g after polymerization.
COMPARISON 3
Polymer Treated Wood Blocks
Four 1 1/16"×1 1/16"×1/4" pine wood blocks weighing a total of 8.55 g were treated in the same manner as Example 31 except that a polymer solution prepared from 10 g of polymethyl methacrylate (Aldrich--low molecular weight), dissolved in 50 ml of toluene and 50 ml of methylene chloride was employed instead of the monomer solution. After the wood preservation treatment the blocks were allowed to air-dry for 48 hours. The treated blocks weighed 11.34 g.
COMPARISON 4
Methylene Chloride Wash of the Treated Wood Blocks
Four wood blocks weighing 13.34 g from Comparison 1 were washed with methylene chloride by the same procedure as Example 32. The wood blocks weighed 7.49 g after drying for 24 hours.
COMPARISON 5
Methylene Chloride Wash of the Treated Wood Blocks
Four wood blocks weighing a total of 8.91 g from Comparison 5 were washed with methylene chloride by the same procedure as Example 32. The wood blocks weighed 7.94 g after drying for 24 hours.
TABLE 10______________________________________Example and Wt. % of TreatedComparison Wood AttributedNo. Polymer Type to the Polymer______________________________________29 5% Pyrithione methacrylate/ 48.5 methyl methacrylate30 5% Pyrithione methacrylate/ 14.0 methyl methacrylate31 5% Pyrithione methacrylate/ 25.9 methyl methacrylate32 5% Pyrithione methacrylate/ 4.4 methyl methacrylate33 5% Pyrithione methacrylate/ 4.2 methyl methacrylate34 1% Pyrithione methacrylate/ 49.1 methyl methacrylate35 1% Pyrithione methacrylate/ 15.4 methyl methacrylate36 1% Pyrithione methacrylate/ 27.5 methyl methacrylate37 1% Pyrithione methacrylate/ 5.2 methyl methacrylate38 1% Pyrithione methacrylate/ 2.3 methyl methacrylate39 Pyrithione methacrylate 23.140 Pyrithione methacrylate 11.841 Pyrithione methacrylate 0.6C-1 Methyl methacrylate 49.4C-2 Methyl methacrylate 15.9C-3 Methyl methacrylate 10.3C-4 Methyl methacrylate 5.3C-5 Methyl methacrylate 4.6______________________________________
Commercial Wood Preservatives
The following commercial wood preservatives were employed for comparative testing. The wood preservatives were applied by the same method described in Example 31.
______________________________________ Wt. of TreatedComparison Wood Biocide Wood attributedNo. Preservative Present to Preservative______________________________________C-6 Weldwood, 4.3% penta- 38.7 Woodlife.sup.7 chlorophenols 0.5% other chlorophenolsC-7 Evans, stain 0.4% Bis(tri- 39.1 and wood butyltin)oxide preservative.sup.8______________________________________ .sup.7 Roberts Consolidated Industries, City of Industry, CA. .sup.8 Evans Products Company, Roanoke, VA.
Wood Rot Test
A test procedure was followed exactly from the following published procedure: H. P. Sutter, International Biodeterioration Bulletin, 14 (3), 95-99 (1978). The organisms employed were Coniophora puteana ATCC 36336 and Lentinus lepideus ATCC 12653 (a creosole-resistant fungus). Duplicates were run in each case. The growth of brown rot (cellulose - degrading) fungi on pine blocks after 25 days at 28° C. are evaluated as:
______________________________________ Growth Key for Table 11:______________________________________ 0 - no growth 1 - slight growth 2 - moderate growth 3 - heavy growth 4 - very heavy growth______________________________________
These results in Table 11 show that pyrithione-containing polymers impregnated in wood, either through a pressure treatment or in-situ formation, were effective in controlling the growth of wood rot organisms while the methyl methacrylate polymer was not. After the methylene chloride washes, the remaining graft copolymers still gave complete control in the case of the homopolymer and moderate control in the other cases. The results also show pyrithione-containing polymers compare favorably against commercial wood preservatives tested in Comparisons C-6 and C-7.
TABLE 11______________________________________Example or GrowthComparison No. C. puteana L. lepideus______________________________________untreated wood 4,3 4,429 0,0 0,030 0,1 0,031 2,1 1,132 1,2 1,133 3,2 4,434 0,0 1,035 1,1 4,436 3,3 3,237 1,3 2,338 3,0 3,439 0,0 0,040 0,0 0,041 0,0 0,0C-1 2,1 4,4C-2 0,0 4,4C-3 1,1 4,4C-4 1,2 3,3C-5 4,3 4,3C-6 0,0 0,0C-7 1,1 3,1______________________________________
Surface Treated Wood Blocks
Four 1 1/16"×1 1/16"×1/4" pine wood blocks were surface treated with either a wood preservative comprising a 10% solution of a pyrithione methacrylate containing polymer in methylene chloride or a commercial wood preservative. The wood blocks were brush coated on all surfaces and in some cases multiple coats were applied. These examples were not pressure treated like the previous examples. These present examples correspond to what a consumer would do to apply a wood preservative.
The amount of biocide applied to each wood block was calculated by determining the weight increase of each wood block after treatment and calculating the biocide present in the weight increase. (See Table 12).
______________________________________ Weight % Biocide inExample Wood Preservative Wood Preservative______________________________________42 0.403% Pyrithione Terpolymer from Example 1343 0.730% Pyrithione Terpolymer from Example 1244 1.36% Pyrithione Co-polymer from Example 1145 1.36% Pyrithione Co-polymer from Example 1146 1.36% Pyrithione Co-polymer from Example 1147 1.36% Pyrithione Co-polymer from Example 11C-8 None MMA/BA Co-polymerC-9 4.3% Pentachloro- Weldwood Woodlife phenol 0.5% Other Chloro- phenols C-10 0.4% Bis(tributyl- Evans stain and tin)oxide wood preservative______________________________________
The results from Table 12 show that pyrithione levels of 7 mg per wood block are effective in controlling C. puteana. Against L. lepideus 25 mg/wood block of pyrithione exhibited complete control and levels as low as 7 mg per wood block allow only slight fungal growth. In all cases pyrithione is superior to the negative control and compared favorably with commercial products.
TABLE 12______________________________________Wood Rot Test AverageExample or Weight Biocide GrowthComparison No. (per Wood Block) C. puteana L. lepideus______________________________________Untreated Wood None 4,4 4,442 7 mg pyrithione 0,0 1,243 14 mg pyrithione 0,0 1,144 10 mg pyrithione 0,3 1,145 25 mg pyrithione 0,0 0,146 41 mg pyrithione 0,0 0,047 49 mg pyrithione 0,0 0,0C-8 None 4,4 0,4C-9 43 mg penta chloro phenol 7 mg other 0,0 0,0 chloro phenols C-10 2 mg bis(tributyl 0,0 2,2 tin)oxide______________________________________ Key: 0 No growth 1 Slight growth 2 Moderate growth 3 Heavy growth 4 Very heavy growth
Antimicrobial Testing
Several biofunctional polymers of Examples 1-16 were tested in a standard Minimum Inhibitory Concentration (MIC) test against 8 different bacteria and 8 different fungi. Also tested in this MIC test were poly methyl methacrylate, sodium pyrithione, DMSO and Triton X-200 as blanks. The results are given below in Tables 13 and 14.
The results show that the pyrithione containing polymers exhibit activity against a variety of bacteria and fungi. Both pyrithione methacrylate monomer and the pyrithione containing polymer have antimicrobial activity similar to sodium pyrithione on an equivalent weight basis of the pyrithione moiety present.
TABLE 13______________________________________Antimicrobial Testing - MIC in ppm Poly MethylSodium Pyrithione Metha- TritonPyrithione Methacrylate crylate DMSO X-200______________________________________Bacteria1 256 256 1024 1024 10242 1024 1024 1024 1024 10243 256 256 1024 1024 10244 4 8 1024 1024 5125 16 32 1024 1024 10246 32 64 1024 1024 10247 64 128 1024 1024 10248 2 0.5 512 1024 1024Fungi1 0.5 1 ND* 1024 10242 0.25 0.25 ND 512 5123 0.5 0.25 ND 1024 10244 0.25 0.25 ND 1024 10245 0.5 0.5 ND 1024 10246 0.25 0.25 ND 512 5127 4 2 ND 1024 10248 2 8 ND 512 512______________________________________ *ND = not determined
TABLE 14______________________________________Antimicrobial Testing of Pyrithione Containing PolymersMIC in ppm______________________________________Polymer (from Example) 1B 2 4 6 8 15 16______________________________________Bac-teria1 1024 1024 1024 1024 1024 1024 10242 1024 1024 1024 1024 1024 1024 10243 1024 1024 1024 1024 1024 1024 10244 32 256 1024 128 1024 64 2565 256 512 1024 ND* ND 256 10246 256 1024 1024 256 1024 256 10257 256 1024 1024 512 1024 128 5128 2 64 1024 512 1024 128 512Fungi1 4 64 1024 64 1024 128 5122 0.25 8 256 16 512 16 1283 4 128 256 16 128 16 1284 0.5 16 256 ND ND 8 1285 4 256 1024 16 1024 128 10246 0.25 0.25 32 2 64 2 327 4 64 512 32 ND 128 10248 16 128 512 0.5 512 256 512______________________________________ *ND = not determined
Key To Tables 13 and 14Microbiological OrganismsBacteria1 Pseudomonas aeruginosa ATCC 90272 Pseudomonas aeruginosa (pyrithione resistant)3 Enterobacter aerogenes ATCC 130484 Staphylococcus aureus ATCC 65385 Pseudomonas syringae ATCC 193106 Pseudomonas phaseolicola ATCC 113557 Xanthomonas vesicatoria ATCC 115518 Xanthomonas phaseoli ATCC 19315Fungi1 Aspergillus niger ATCC 164042 Trichophyton mentagrophytes ATCC 95333 Candida albicans ATCC 102314 Helminthosponium oryzae ATCC 343935 Fuscarium oxysporum ATCC 156436 Glomerella augulata ATCC 105937 Aeternaria solani ATCC 110788 Rhizoctonia solani ATCC 28268
Comparing Pyrithione-Containing Polymers to Their Monomers
EXAMPLE 48
A Trypticase Agar plate was swabbed with a suspension of Aspergillus niger ATCC 16404 spores. A well was punched out in the center of the plate with a #3 cork borer. Five milligrams of finely ground 1:24 pyrithione methacrylate/methyl methacrylate copolymer from Example 8 was added to the well and covered with 50 ul sterile distilled water. The plate was incubated at 28° C. for three days. There was no inhibition of growth of mold fibers on the plate and slight inhibition of sporulation at the edge of the well. This result shows that the polymer-bound pyrithione methacrylate does not leach readily from the polymer matrix.
COMPARISON 11
Five milligrams of pyrithione methacrylate monomer was tested as described in Example 1. A zone of inhibition of growth 45 mm in diameter and of inhibition of sporulation 54 mm in diameter was observed. This result shows that monomeric pyrithione methacrylate leaches easily in an aqueous environment.
EXAMPLE 49
The terpolymer of a emulsion polymerization of pyrithione methacrylate, methyl methacrylate and butyl acrylate, such as described in Example 16, is a milk-white latex suitable for direct formulation in a water-based paint of any desired color. Similarly, a solution of a pyrithione methacrylate/methyl methacrylate copolymer, such as that described in Example 8, in organic solvents such as toluene, methylene chloride, acetone, and the like is clear and nearly water-white. The copolymer is therefore suitable for direct incorportion in a solvent-based paint of any desired color.
COMPARISON 12
Both aqueous emulsions and organic solutions of pyrithione methacrylate monomer, even at concentrations of 0.1%, are bright, canary yellow. Therefore formulation of paints of colors other than yellow requires addition of excessive amounts of pigments to mask the yellow color, and, in cases where white, off-white, or pales hues are desired, may not be practical.
EXAMPLE 50
A sample of the pyrithione methacrylate/methyl methacrylate copolymer prepared as described in Example 8, was placed in a glass jar and stored at ambient conditions. After 24 months the copolymer showed no signs of degradation--it was free-flowing and retained its original color, demonstrating excellent storage stability.
COMPARISON 13
A sample of pyrithione methacrylate monomer, prepared as described in Example 1A, was placed in a glass jar and stored at ambient conditions. After about three days the yellow crystals had changed to a brown viscous oil, demonstrating the severe susceptibility of the monomer to thermal degradation. | Disclosed is a bioactive polymer comprising an effective biocidal amount of moieties derived from pyrithione and having the formula ##STR1## wherein R 1 , R 2 and R 3 are individually selected from hydrogen and alkyl groups having from 1 to 4 carbon atoms; and PT represents the pyrithione moiety which is defined as ##STR2## wherein R 4 , R 5 , R 6 and R 7 are individually selected from hydrogen and, a lower alkyl group having from 1 to about 8 carbon atoms, a lower alkoxy group having from 1 to about 8 carbon atoms, a nitro group and a halo group. | 8 |
This application claims priority under 35 U.S.C. §§119 and/or 365 to 01202964.5 filed in China on Jan 12, 20001; the entire content of which is hereby incorporated by reference.
This invention relates to a lighter, and in particular a lighter which is not easily operable by a child.
BACKGROUND OF THE INVENTION
There are in existence a large number of lighters. Because of the relatively simple way in which such lighters can be operated, it is considered desirable to incorporate safety mechanism into such conventional lighters to prevent unintentional use thereof, e.g. by children. Lighter incorporating self-retrieving safety mechanisms are disclosed in, e.g. U.S. Pat. Nos. 5,538,417 and 6,099,297. Such safety mechanisms are usually very complex and thus costly and complicated to manufacture.
It is thus an object of the present invention to provide a lighter with an actuating mechanism which cannot be easily operable by a young child, so that the actuating mechanism effectively acts as a safety mechanism for preventing unintentional use of the lighter by young children.
It is also an object of the present invention to at least provide a useful alternative to the trade and public.
SUMMARY OF THE INVENTION
According to a first aspect of the present invention, there is provided a lighter including a body and an actuator, wherein said body includes a spark generator and a container adapted to contain fuel under pressure, said body further including a longitudinal end at which a flame is adapted to be produced upon movement of said actuator relative to said body, wherein said actuator is movable relative to said body substantially parallel to a longitudinal axis of said body, wherein said actuator includes an outer surface which is operable by a user to move said actuator relative to said body, wherein said outer surface of said actuator is generally orthogonal to said longitudinal end of said body, and wherein said actuator is generally as long as said body.
According to a second aspect of the present invention, there is provided a lighter including a body and an actuator, wherein said body includes a spark generator and a container adapted to contain fuel under pressure, said body further including a longitudinal end at which a flame is adapted to be produced upon movement of said actuator relative to said body, wherein said actuator is movable relative to said body substantially parallel to a longitudinal axis of said body, wherein said actuator is provided outside a lateral side of said body, and wherein said actuator is generally as long as said body.
BRIEF DESCRIPTION OF THE DRAWINGS
Embodiments of the present invention will now be described, by way of examples only, with reference to the accompanying drawings, in which:
FIG. 1 is a longitudinal cross sectional view of a lighter according to a first embodiment of the present invention in a normal state;
FIG. 2 is a longitudinal cross sectional view of the lighter shown in FIG. 1 in an operating state;
FIG. 3A is a cross sectional view of the lighter taken along the line A—A in FIG. 1;
FIG. 3B is a cross sectional view of the lighter taken along the line B—B in FIG. 1;
FIG. 4 shows the steps of formation of a windscreen cap of the lighter shown in FIG. 1;
FIG. 5 shows the structure of a first arrangement of a actuating button of the lighter shown in FIG. 1;
FIG. 6 shows the structure of a second arrangement of a actuating button of the lighter shown in FIG. 1;
FIG. 7A is an enlarged partial side view of a thumb-engagement area of the lighter shown in FIG. 1;
FIG. 7B is an enlarged partial front view of the thumb-engagement area of the lighter shown in FIG. 1;
FIG. 8 is an enlarged view showing the engagement between a lead wire and an upper part of a piezo unit of the lighter shown in FIG. 1;
FIGS. 9A and 9B show the operation of the lighter shown in FIG. 1;
FIG. 10 shows the operation of a lighter according to a second embodiment of the present invention;
FIG. 11 is a longitudinal sectional view of the lighter shown in FIG. 10 in a normal state; and
FIG. 12 is a longitudinal sectional view of the lighter shown in FIG. 10 in an operating state.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 to 3 B show various cross sectional views of a lighter according to the present invention, generally designated as 100 . The lighter includes a body 102 whose transverse cross section is generally oval in shape. At a top longitudinal end of the body 102 is a windscreen cap 103 made of a metallic material. Within the body 102 is provided a cavity 104 for containing fuel under pressure. Such fuel may be introduced into the cavity 104 via a valve 106 provided proximate an end cap 108 of the body 102 . The valve 106 is biased by a spring 110 towards a closed configuration, as shown in FIGS. 1 and 2, whereby exit of fuel from the cavity 104 via the valve 106 to the outside environment is normally prevented. The valve 106 may be moved, in the usual manner, to an open configuration, against the biasing force of the spring 110 , to allow fuel under pressure to be introduced into the cavity 104 .
A tube 112 leads from the cavity 104 to an electrically conductive nozzle 114 , whereby the fuel in the cavity 104 is supplied to the nozzle 114 . The nozzle 114 is biased by a spring 116 to a closed position, as shown in FIG. 1, whereby exit of fuel from the cavity 104 via the nozzle 114 to the outside environment is normally prevented.
Provided within the body 102 are a piezo electric unit 118 and a hammer 120 for generating spark. The piezo electric unit 118 includes an upper portion 117 , which is an electrically conductive back mass made of zinc alloy. Leading from and contacting with the upper portion 117 is an electrically conductive lead wire 122 . As can be seen very clearly in FIG. 8, the lead wire 122 has a bent lower end 123 , for ensuring better physical and electrical contact with the upper portion 117 of the piezo electric unit 118 . An electrically conductive horizontal extension 124 is in contact with an upper end of the lead wire 122 , so that the extension 124 and the lead wire 122 are movable simultaneously. A lever 126 made of an electrically conductive material is engaged with a neck portion 127 of the nozzle 114 , and is pivotable to move the nozzle 114 to a raised open position, as shown in FIG. 2, in which fuel inside the cavity 104 is allowed to exit to the outside environment via the nozzle 114 .
A hammer 120 is in electrical connection with an electrically conductive block 128 on the end cap 108 . The block 128 leads, via an electrically conductive lead wire 128 a to an end 128 b closely proximate the exit end of the nozzle 114 .
Mounted on a lateral side of the body 102 is an actuating button 130 , which is roughly as long as the body 102 . The actuating button 130 is engaged with the extension 124 for simultaneous movement. On a curved outer surface 134 of the button 130 are a number of ridges 136 protruding outwardly of the outer surface 134 . The ridges 136 run parallel to one another and are perpendicular to the longitudinal axis L—L of the body 102 . The outer surface 134 , which is orthogonal to the longitudinal end of the lighter 100 , may be engaged by fingers of a user to slide the button 130 relative to the body 102 between a normal position, as shown in FIG. 1, to an operating position, as shown in FIG. 2 . It can be seen that the direction of movement of the button 130 relative to the body 102 is parallel to the longitudinal axis L—L of the body 102 . On a lateral side of the body 102 opposite to the actuating button 130 is provided with a thumb-engagement area 138 , details of which will be discussed below.
In the normal position as shown in FIG. 1, the nozzle 114 is in the closed position in which no fuel exits from the nozzle 114 . When the button 130 is slid downwardly relative to the body 102 to the operating position as shown in FIG. 2, the extension 124 pivots the lever 126 , which in turn raises the nozzle 114 to the open position, so that fuel under pressure in the cavity 104 exits the nozzle 114 to the vicinity between the end 128 b of the lead wire 128 a and the nozzle 114 .
At the same time, the upper portion 117 is moved downward by the lead wire 122 to come into contact with the hammer 120 of the piezo electric unit 118 , against the biasing force of a reset spring 132 . In this way, the nozzle 114 , the lever 126 , the extension 124 , the lead line 122 , the upper portion 117 , the lower portion 120 , the block 128 , the lead wire 128 a and the end 128 b form an electric circuit which is only open in the small gap between the end 128 b and the nozzle 114 . When an electrically conductive head metal 133 of the upper portion 117 is hammered by the hammer 120 , the piezo unit 118 will undergo an instantaneous minor compression/deformation, whereupon an electric arc will be produced in the gap between the end 128 b and the nozzle 114 , such that a spark is generated, which ignites the fuel leaving the nozzle 114 , so that a flame is produced at the top longitudinal end of the lighter 100 .
Upon release of the downward pushing force on the button 130 , the reset spring 132 will return the button 130 to its normal position as shown in FIG. 1 . The lever 126 will also be returned to its normal closed position as shown in FIG. 1, under the biasing force of the spring 116 . No fuel can now exit the cavity 104 via the nozzle 114 .
As shown in FIG. 4, a small rectangular metal plate 103 a from a long strip of metal plate is worked on to form the cap 103 . Unwanted portions of the small metal plate 103 a are punched away, e.g. by a punching machine, to form a punched metal plate 103 b . The punched metal plate 103 b has a generally oval central portion 103 c with a circular aperture 103 d. The central portion 103 c is joined with two generally rectangular platelets 103 e , 103 f . Each of the platelets 103 e , 103 f is bent to form a curved plate, and they are then bent toward each other to form the windscreen cap 103 .
FIG. 5 shows a first example of an actuating button 130 a , with an exploded view of the components shown in a dotted oval. This actuating button 130 a may be used in the lighter 100 . The actuating button 130 a includes a curved outer button 140 a which is as long as the body 102 . A number of slots 142 a are provided on the outer button 140 a. These slots 142 a run parallel to one another and are perpendicular to the length of the button 130 a . Engaged with the outer button 142 a is a rib cage 144 a with a number of ribs 146 a running parallel to one another. When the outer button 140 a is engaged with the rib cage 144 a , each rib 146 a is received within a respective slot 142 a and protrudes beyond a curved outer surface 148 a of the outer button 140 a. Also engaged with the rib cage 144 a and the outer button 140 a is an inner button 150 a , which is secured with the lead wire 122 and the extension 124 , as discussed above.
FIG. 6 shows the structure of a second example of an actuating button 130 b , with an exploded view of the components shown in a dotted oval. The button 130 b includes an outer button 140 b engaged with an inner button 150 b , the extension 124 and the lead wire 122 . Formed integrally with the outer button 140 are a number of ridges 146 b running parallel to one another and perpendicular to the length of the outer button 140 b. These ridges 146 b protrude beyond a curved outer surface 148 b of the outer button 140 b . Both the ribs 146 a of the button 130 a and the ridges 146 b of the button 130 b can enhance the engagement between the fingers of a user and the button 130 a , 130 b.
As shown in FIGS. 7A and 7B, the thumb-engagement area 138 is generally oval in shape and includes a number of small circular recesses 152 . Each circular recess 152 is formed of an upper stepped portion 154 a and a lower stepped portion 154 b . These circular recesses 152 serve to increase the friction, and thus enhance the engagement, between the thumb of the user and the body 102 of the lighter 100 . The circular recesses 152 may also be arranged to form a pattern, as shown in FIG. 7 B.
As can be seen in FIGS. 9A and 9B, a user may hold the lighter 100 by engaging his/her thumb 160 with the thumb-engagement area 138 , while some of the remaining fingers 162 rest on the ridges 136 of the button 130 . The button 130 may then be moved by the remaining fingers 162 downwardly relative to the body 102 of the lighter 100 , or put another way, the body 102 may be moved by the thumb 160 upwardly relative to the button 130 , to produce a flame, in the manner discussed above.
It is found in practice that the movement of the hand and fingers required to slide the button 130 relative to the body 102 to actuate the lighter 100 cannot be performed by most small children, e.g. ones under the age of three. The present arrangement thus effectively acts as a safety mechanism for preventing unwanted operation by most small children.
In the lighter 100 discussed above, a flame is produced when the button 130 is moved away from the top end of the lighter 100 . An alternative embodiment is shown in FIGS. 10 to 12 , to be discussed below. As can be seen in FIG. 10, in a lighter 200 according to this alternative embodiment, a body 202 may be moved downwardly relative to a button 230 , or put another way, a button 230 may be moved upwardly relative to a body 202 , to the position as shown in FIGS. 10 and 12, to produce a flame. An advantage of this arrangement is that an upper end 204 of the button 230 may act as a windscreen.
As can be seen in FIGS. 11 and 12, the general structure of the lighter 200 is similar to the lighter 100 discussed above. Only the main differences will thus be discussed below. The button 230 is mounted on a lateral side of the body 202 for relative sliding movement therebetween. Secured with the button 230 is a horizontal extension 224 which, in the normal position as shown in FIG. 11, is positioned below a lever 226 . When the button 230 is moved upward relative to the body 202 , the extension 224 will pivot the lever 226 to raise a nozzle 214 , against the biasing force of a spring 216 , to an open position (as shown in FIG. 12) in which fuel under pressure in a cavity 204 may exit via the nozzle 214 .
When the button 230 is moved upwardly, against the biasing force of a spring 270 , a hammer 220 of a piezo electric unit 217 is also brought upwardly, against the biasing force of a spring 232 , to hammer a head metal 219 of the piezo electric unit 217 , against the backing force of a back mass 218 , to generate a spark between an end 228 b of a lead wire 228 a and the nozzle 214 , in the same manner as in the lighter 100 discussed above. The spark will then ignite the fuel exiting the nozzle 214 to produce a flame.
Upon release of the upward pushing force on the button 230 , the button 230 and the hammer 220 of the piezo electric unit 217 will return to the normal position shown in FIG. 10, upon the biasing force of the springs 270 and 232 . The nozzle 214 will also return to the normal position shown in FIG. 10, upon the biasing force of the spring 216 .
It should be understood that the above only illustrates examples whereby the present invention may be carried out, and that various modifications and/or alterations may be made thereto without departing from the spirit of the invention.
It should also be understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may be provided in combination in a single embodiment. Conversely, various features of the invention which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any appropriate sub-combinations. | A lighter is disclosed as including a body and an button, the body including a piezo electric unit and a container for containing fuel under pressure, the body further including an at which a flame may he produced upon movement of the button relative to the body, and the button is slidable relative to the body parallel to a longitudinal axis of the body, and the button has an outer surface which may be operated by a user to slide the button relative to the body, and the outer surface of the button is generally orthogonal to the end of the body, and wherein the button is generally as long as the body. | 5 |
FIELD OF THE INVENTION
[0001] The present invention relates to nanoscale electric devices, and more particularly, to a method for making nanoscale wires and gaps for switches and transistors.
BACKGROUND OF THE INVENTION
[0002] Reducing the feature size of integrated circuit components is a continuing goal of semiconductor process designers. In the past, such reductions have led to decreased cost and increased operating speed. Device fabrication depends on techniques that rely on masks to define the boundaries of the transistors and conductors. For example, metal and semiconductor conductor patterns are fabricated by lithography in which masks determine the location and size of the patterns. The conductivity in semiconductors can also be controlled by implanting ions. The areas that are to be implanted are typically defined by an opening in a mask. Similarly, transistors require the selective implantation of ions. Unfortunately, conventional masking techniques are inadequate when nanometer scale components are to be fabricated.
[0003] Broadly, it is the object of the present invention to provide a self-assembled masking technique for use in fabricating nanoscale wires and devices in integrated circuits.
[0004] These and other objects of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.
SUMMARY OF THE INVENTION
[0005] The present invention is a method for forming first and second linear structures of a first composition that meet at right angles, there being a gap at the point at which the structures meet. The linear structures are constructed on an etchable crystalline layer having the first composition. First and second self-aligned nanowires of a second composition are grown on a surface of the etchable crystalline layer, the first nanowire growing at right angles to the second nanowire. The first nanowire is separated from the second nanowire by a gap of less than 10 nm at their closest point. Portions of the etchable layer that are not under the first and second nanowires are then etched using the first and second nanowires as a mask thereby forming the first and second linear structures of the first composition. The nanowires are grown by depositing a material of the second composition which forms crystals on the surface that have an asymmetric lattice mismatch with respect to the crystalline surface. The linear structures so formed are well suited for the fabrication of nanoscale transistors having a first elongated doped semiconductor wire having a width between 1-100 nm on an insulative substrate. A second wire at right angles to the first ridge acts as the gate of the transistor. The two wires are separated by a gap of between 0.4 and 10 nm at their closest point. By filling the gaps with appropriate materials, the wires and gaps can also function as a nanoscale memory switch and a transistor.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIGS. 1 (A)-(C) are prospective views at various stages in the fabrication process of a substrate 12 in which nanowires are to be constructed.
[0007] [0007]FIG. 2 is a top view of a portion of a substrate 20 on which two self-assembled nanowires and a nanoscale gap shown at 21 and 22 have been grown.
[0008] [0008]FIG. 3 is a perspective view of a semiconductor nanowire structure that forms a transistor.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The present invention is based on the observation that thin “nanowires” of ErSi 2 can be grown epitaxially on the (001) plane of silicon without masking the silicon. The manner in which these wires are grown is discussed in detail in “Self-assembled growth of epitaxial erbium disilicide nanowires on silicon (001)” by Yong Chen, Douglas A. A. Ohlberg, Gilberto Medeiros-Ribeiro, Y. Austin Chang, and R. Stanley Williams in Applied Physics Letters, 76, p. 4004, June 2000, which is hereby incorporated by reference. The ErSi 2 nanowires are grown by depositing Er on the surface of the silicon and then heating the silicon to drive the reaction to completion. The Er can be deposited with an in situ electron-beam evaporator at temperatures between room temperature and 620° C. The annealing operation can be carried out at temperatures between 575 and 800° C. The resulting nanowires are oriented along the two perpendicular <110>directions ([110] and [1-10]) and at right angles thereto.
[0010] The self-assembly of the nanowires depends on an asymmetric lattice mismatch between the ErSi2 and the underlying silicon substrate. The overlayer material must be closely-lattice matched to the substrate along one major crystallographic axis but have a significant lattice mismatch along all other crystallographic axes within the interface between the epitaxial crystal and the substrate. In principle, this allows the unrestricted growth of the epitaxial crystal in the first direction but limits the width in the other.
[0011] While the example given herein utilizes ErSi 2 grown over Si, other materials and substrates can be utilized. In general, any crystalline material that can be characterized by an asymmetric lattice mismatch, in which the first material has a close lattice match (in any direction) with the second material and has a large lattice mismatch along all other crystallographic axes within the interface between the epitaxial crystal and the substrate. For example, ScSi 2 , GdSi 2 , and DySi 2 grown on Si(001) substrates may also be utilized. Such structures are taught in Yong Chen, Douglas A. A. Ohlberg, and R. Stanley Williams in Journal of Applied Physics, 91, p. 3213, March 2002, which is hereby incorporated by reference. A close lattice match means that the absolute value of lattice mismatch between the two crystal materials is less than 4%. A large lattice mismatch means that the absolute value of lattice mismatch between the two crystal materials is within the range of about 4 to 10%. While any crystallographic direction may be chosen, the present invention preferably utilizes a material having the asymmetric lattice mismatch along a major (or low Miller-index) crystallographic direction within the interface between the epitaxial crystal and the substrate. By “major crystallographic direction” is meant any direction along which the crystalline material comprising the nanowire may prefer to grow within the interfacial plane.
[0012] In the case of ErSi 2 , ScSi 2 , GdSi 2 , and DySi 2 nanowires, the nanowires are typically 2-20 nm wide and have lengths of a few hundred nm. The nanowires are self-elongating once the silicide crystal has been seeded at a particular location. The nanowires can be seeded at locations where special seeding materials or growth windows are predefined by lithography methods.
[0013] The manner in which these nanowires are utilized to generate two silicon nanowires at the right angle and a nanoscale gap between them will now be explained with reference to FIGS. 1 (A)-(C) which are prospective views of a silicon substrate 12 in which a single conducting silicon nanowire is to be constructed at various stages in the fabrication process. The upper region 13 of silicon substrate 12 is doped with a suitable element to render the material conducting. An insulating layer 19 such as SiO x is buried under the conductive layer. The insulating layer typically has a thickness between 1-500 nm. The insulating layer can be made by implanting oxygen ions into the silicon substrate and then annealing the substrate to form a buried layer of SiO x . An ErSi 2 nanowire 14 is then deposited over the region of substrate 12 that is to contain the silicon nanowire. FIG. 1(B) illustrates a prospective view of the present invention wherein the portions of the material that were above the insulating layer but not masked by the nanowire have been removed leaving a ridge 16 having an ErSi 2 layer on the top thereof. These portions can be removed by reactive ion etching (RIE). The etching can be stopped at the exposed surface of the insulating layer. Finally, the ErSi 2 can be removed, if desired, by selective chemical etching leaving the Si nanowire 18 as shown in FIG. 1(C).
[0014] The present invention is based on the observation that the ErSi 2 nanowires provide a masking pattern that is ideal for the fabrication of nanoscale gaps for transistors and memory switches. The ErSi 2 nanowires grow along the [110] crystal direction and also along the [1-10] direction. When two of these nanowires are seeded such that the two nanowires will meet at right angles, a nanoscale gap can be formed between the first and the second nanowires at the point at which one nanowire meets the other nanowire at a right angle. The growth of the first nanowire will be stopped as it gets close to the second nanowire since the two nanowires have different crystallographic orientations.
[0015] Refer now to FIG. 2, which is a top view of a portion of a silicon substrate 20 on which two ErSi 2 nanowires shown at 21 and 22 have been grown. When two ErSi 2 wires meet at right angles, a small gap 23 remains between the ErSi 2 nanowires. The gap is typically 0.4-10 nm.
[0016] Refer now to FIG. 3, which is a perspective view of a silicon nanowire structure that forms a switch or a transistor. Transistor 30 is constructed from two silicon nanowires shown at 32 and 33 . Nanowire 33 acts as the gate of transistor 30 . The ends of nanowire 32 form the source and drain of transistor 30 . Nanowires 32 and 33 are fabricated using a mask of the type shown in FIG. 2. Due to the small gap distance 34 , when a voltage is applied on nanowire 32 , the electric field will influence and control the current flow in nanowire 33 . The gap can be filled with a material such as molecules, ferroelectric materials, and nanoscale particles that store charge or electric dipole moment in the gap. Hence, the transistor can provide gain or nonvolatile switching for logic and memory applications. If two-electrode devices are formed between the nanowires 32 and 33 , an electric field applied between the two electrodes can switch the electric conductivity of the materials adjacent to the gap. Such a device is taught in U.S. Pat. No. 6,128,214, which describes how a memory cell can be formed between the two nanowires.
[0017] While the above embodiments of the present invention have been described in terms of masks generated from ErSi 2 nanowires, as noted above, other materials can be utilized. In general, any material that has a sufficiently asymmetric lattice mismatch can be utilized over an appropriate substrate. Metal silicides represented as the chemical formula MSi 2 grown over silicon are examples of such nanowire systems. Here, M is a metal selected from the group consisting of Sc, Y, and the rare earths. The preferred rare earths are Er, Dy, Gd, Th, Ho, Th, Y, Sc, Tm, and Sm.
[0018] In principle, any single crystal material that is useful in the fabrication of nanowires may be used in combination with any single crystal material that serves as a layer on which the nanowires can be grown, provided that the asymmetric lattice mismatch conditions described above are met. The present invention may be practiced using self-assembled crystals grown on single crystal layers such as metals, insulators such as sapphire, and semiconductors such as germanium, III-V compound semiconductors, whether binary (e.g., GaAs, InP, etc.), ternary (e.g., InGaAs), or higher (e.g., InGaAsP), II-VI compound semiconductors, and IV-VI compound semiconductors. Examples of such combinations are listed in U.S. Pat. No. 5,045,408, entitled “Thermodynamically Stabilized Conductor/Compound Semiconductor Interfaces”, issued on Sep. 3, 1991, to R. Stanley Williams et al, the contents of which are incorporated herein by reference. Specific examples of semiconductor substrate materials include Si, Ge, Ge x Si 1-x where 0<x<1, GaAs, InAs, AlGaAs, InGaAs, AlGaAs, GaN, InN, AlN, AlGaN, and InGaN. Specific examples of metal substrate materials include Al, Cu, Ti, Cr, Fe, Co, Ni, Zn, Ga, Nb, Mo, Pd, Ag, In, Ta, W, Re, Os, Ir, Pt, and Au, and alloys thereof.
[0019] Various modifications to the present invention will become apparent to those skilled in the art from the foregoing description and accompanying drawings. Accordingly, the present invention is to be limited solely by the scope of the following claims. | A method for forming first and second linear structures of a first composition that meet at right angles, there being a gap at the point at which the structures meet. The linear structures are constructed on an etchable crystalline layer having the first composition. First and second self-aligned nanowires of a second composition are grown on this layer and used as masks for etching the layer. The self-aligned nanowires are constructed from a material that has an asymmetric lattice mismatch with respect to the crystalline layer. The gap is sufficiently small to allow one of the structures to act as the gate of a transistor and the other to form the source and drain of the transistor. The gap can be filled with electrically switchable materials thereby converting the transistor to a memory cell. | 8 |
CLAIM OF PRIORITY
[0001] This application claims priority from U.S. Provisional Patent Application No. 60/843,640, filed on Sep. 11, 2006.
TECHNICAL FIELD OF THE INVENTION
[0002] The present invention relates to quantum cryptography, and in particular relates to quantum key distribution (QKD) systems that use high-altitude platforms.
BACKGROUND ART
[0003] QKD involves establishing a key between a sender (“Alice”) and a receiver (“Bob”) by using either single-photons or weak (e.g., 0.1 photon on average) optical signals (pulses) called “qubits” or “quantum signals” transmitted over a “quantum channel.” Unlike classical cryptography whose security depends on computational impracticality, the security of quantum cryptography is based on the quantum mechanical principle that any measurement of a quantum system in an unknown state will modify its state. Consequently, an eavesdropper (“Eve”) that attempts to intercept or otherwise measure the exchanged qubits introduces errors that reveal her presence.
[0004] The general principles of quantum cryptography were first set forth by Bennett and Brassard in their article “Quantum Cryptography: Public key distribution and coin tossing,” Proceedings of the International Conference on Computers, Systems and Signal Processing, Bangalore, India, 1984, pp. 175-179 (IEEE, New York, 1984). Specific QKD systems are described in U.S. Pat. No. 5,307,410 to Bennett, and in the article by C. H. Bennett entitled “Quantum Cryptography Using Any Two Non-Orthogonal States”, Phys. Rev. Lett. 68 3121 (1992). The general process for performing QKD is described in the book by Bouwmeester et al., “The Physics of Quantum Information,” Springer-Verlag 2001, in Section 2.3, pages 27-33.
[0005] U.S. Pat. No. 5,966,224 to Hughes et al. (“the '224 patent”), which patent is incorporated by reference herein, discloses a Pockels-cell-based optical system for providing secure communications between an earth station and a low-orbit spacecraft. The optical system of the '224 patent enables secure long-range communication through space to provides secure satellite-based telemetry using the principles of QKD.
[0006] Satellite-based QKD presents serious technical challenges. For instance, the ground-satellite link is normally in the range from 100-400 km. The faint quantum signal encounters turbulence, weather and scattering from airborne particles, particularly over the 10-20 km closest to the ground. These factors result in ˜30-50 dB loss. Accordingly, the system of the '224 patent would require quantum signals having a relatively high average number of photons per pulse in order to have a reasonable data rate. This leads to a decrease in the overall security of the system. Further, use of a Pockels cell for quantum signal modulation presents a security risk because they have a pronounced electromagnetic interference (EMI) signature that could be detected by an eavesdropper and used to discern the quantum signal modulations.
BRIEF DESCRIPTION OF THE INVENTION
[0007] The present invention includes systems and methods for performing QKD using one or more high-altitude platforms (HAPs). The system includes a second QKD station supported by the HAP so as to be in free-space communication with the first QKD station over an optical path via an optical quantum communication channel that carries quantum signals, an optical synchronization channel that carries synchronization signals, an optical beacon channel that carries beacon signals, and a radio-frequency (RF) channel that carries RF signals. The beacon signals are used to detect changes in the optical path and correct the synchronization signals so as to gate the first and second SPD pairs to correspond to arrival times of the quantum signals at said first and second SPD pairs. The system does not require a Pockels cell for quantum signal modulation, thereby improving the security of the system over prior art systems.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a schematic diagram of an example embodiment of a QKD station ALICE suitable for use in a HAP QKD configuration;
[0009] FIG. 2 is a schematic diagram of an example embodiment of a QKD station BOB suitable for use in combination with QKD station ALICE described immediately above and shown in FIG. 1 , for use in a HAP configuration;
[0010] FIG. 3 is a schematic diagram of an example embodiment of a HAP-based QKD system that employs a HAP in the form of a zeppelin;
[0011] FIG. 4 is a schematic diagram illustrating a second example embodiment of a HAP-based QKD system used to transfer quantum keys between QKD stations ALICE, BOB- 1 and BOB- 2 , wherein BOB- 1 and BOB- 2 at different locations L 1 and L 2 and ALICE resides in the HAP;
[0012] FIG. 5 is a schematic diagram of a third example embodiment of HAP-based QKD system wherein HAP 300 includes both ALICE and BOB QKD stations;
[0013] FIG. 6 is a schematic diagram of a fourth example embodiment of a HAP-based QKD system that employs entangled photons to perform QKD; and
[0014] FIG. 7 is a schematic diagram of a fifth example embodiment of a HAP-based QKD system that involves a spacecraft that includes a QKD station BOB, wherein the QKD system allows for a common key to be provided to a ground based QKD station and a space-based QKD station.
[0015] The various elements depicted in the drawing are merely representational and are not necessarily drawn to scale. Certain sections thereof may be exaggerated, while others may be minimized. The drawing is intended to illustrate an example embodiment of the invention that can be understood and appropriately carried out by those of ordinary skill in the art.
DETAILED DESCRIPTION OF THE INVENTION
[0016] The present invention is directed to QKD systems and methods that employ high-altitude platforms (HAPs). An example embodiment of QKD stations ALICE and BOB suitable for use with HAPs is first described, follow by several different example embodiments of HAP-based QKD systems that employ ALICE and BOB.
ALICE
[0017] FIG. 1 is a schematic diagram of an example embodiment of a QKD station ALICE. ALICE includes quantum optics communication layer 4 A, and a classical optics communication layer 6 A and a radio-frequency (RF) communications layer 8 A, all operably coupled to a controller CA.
[0018] Quantum optics layer 4 A includes a laser unit 12 optically coupled to a beam splitter 30 that has an input port (face) 31 and output faces 32 and 33 . Beam splitter 30 is optically coupled to laser unit 12 via an optical fiber section F 2 optically coupled to input face 31 . Beam splitter 30 in turn is optically coupled to another beam splitter 40 that has two input faces 41 and 42 and two output faces 43 and 44 . Beam splitter 40 is optically coupled to beam splitter 30 via an optical fiber section F 3 optically coupled to output face 33 and input face 41 . Optical fiber section F 3 includes a delay line DL.
[0019] Beam splitters 30 and 40 are also optically coupled to one another via an optical fiber section F 4 that is optically coupled to output face 32 and input face 43 . A phase modulator MA is arranged in optical fiber section F 4 . A detector DA is optically coupled to beamsplitter output face 43 via an optical fiber section F 5 . An optical telescope 50 A is optically coupled to output face 43 of beamsplitter 40 via an optical fiber section F 6 . Laser unit 12 and phase modulator MA are operably coupled to controller CA.
[0020] Classical optics communications layer 6 A includes an optical synchronization unit 110 A and a beacon unit 120 A each operably coupled to controller CA and that include respective telescopes 114 A and 124 A.
[0021] RF communication layer 8 A includes an RF transceiver 130 A operably coupled to controller CA. RF transceiver 130 includes an antenna 132 A.
[0022] Controller CA includes a key bank 180 that stores classical and/or quantum keys that are either generated by ALICE and BOB, and/or that are pre-loaded.
BOB
[0023] FIG. 2 is a schematic diagram of an example embodiment of a QKD station BOB suitable for use in combination with QKD station ALICE described immediately above and shown in FIG. 1 . BOB also includes a quantum optics communication layer 4 B, a classical optics communication layer 6 B, and a RF communications layer 8 B, all operably coupled to a controller CB and to the corresponding layers at ALICE, as described below. Quantum optics communication layers 4 A and 4 B constitute a quantum channel. Classical optics communication layers 6 A and 6 B constitute a synchronization channel and a beacon channel. RF communication layers 8 A and 8 B constitute an RF channel.
[0024] Quantum optics communications layer 4 B includes a 50/50 beamsplitter 200 that has an input face 201 and two output faces 202 and 203 . Quantum optics layer also includes two polarizing beamsplitter 206 and 210 . Beamsplitter 206 has an input face 207 and two output faces 208 and 209 . Beamsplitter 210 has an input face 211 and two output faces 212 and 213 .
[0025] Beamsplitter 200 is optically coupled to beamsplitter 206 via an optical fiber section F 7 optically coupled to output face 202 and input face 207 . Beamsplitter 200 is also optically coupled to beamsplitter 210 via an optical fiber section F 8 optically coupled to output face 203 and input face 211 . A half-wave plate 20 B is arranged in optical fiber section F 8 . An optical telescope 50 B is optically coupled to input face 201 of beamsplitter 200 via an optical fiber section F 9 .
[0026] Quantum optics communications layer 4 B also includes a first set of SPDs DB 1 and DB 2 optically coupled to beamsplitter 206 at output faces 208 and 209 , respectively. Likewise, a second set of SPDs DB 3 and DB 4 are optically coupled to beamsplitter 210 at output faces 212 and 213 , respectively. Each SPD is operably coupled to controller CB.
[0027] Classical optics communications layer 6 B includes an optical synchronization unit 110 B and a beacon unit 120 B each operably coupled to controller CB and that include respective telescopes 114 B and 124 B.
[0028] RF communication layer 8 B includes an RF transceiver 130 B operably coupled to controller CB. RF transceiver 130 includes an antenna 132 B.
[0029] A QKD system formed from ALICE and BOB of FIGS. 1 and 2 communicates over free-space. Quantum optics communication layers 4 A and 4 B are in optical communication via telescopes 50 A and 50 B. In an example embodiment, adaptive optics are employed in combination with telescopes 50 A and/or 50 B or other type of optical system to correct wavefront errors in the optical signals (pulses) that arise due to atmospheric distortion. Classical optics communication layers 6 A and 6 B are in optical communication via synchronization-unit telescopes 114 A and 114 B, and via beacon-unit telescopes 124 A and 124 B. The RF communications layers 8 A and 8 B are in RF communication via RF signals 33 A transmitted by antenna 32 A and received by antenna 32 B, and via RF signals 33 B transmitted by antenna 33 B and received by antenna 32 A.
General QKD System Operation
[0030] In operation, the quantum optics communication layer 4 A at ALICE operates by controller CA sending a signal S 0 to laser 12 to cause the laser to emit a polarized optical pulse P 0 that travels over optical fiber F 2 to beamsplitter 30 . Polarized optical pulse P 0 enters beamsplitter 30 at input face 31 . Beamsplitter 30 splits this pulse into two orthogonally polarized (say, horizontal (H) polarized and vertical (V) polarized) optical pulses P 1 and P 2 that exit the beamsplitter at output faces 32 and 33 and travel over optical fiber sections F 4 and F 3 , respectively. Optical pulse P 2 enters beamsplitter 40 at input face 42 and because of its polarization, is directed out of output face 44 and over to SPD DA 1 via optical fiber section F 5 . The detection of optical pulse P 2 is used for stabilizing ALICE.
[0031] Meantime, optical pulse P 1 travels over optical fiber section F 4 to input face 42 of beamsplitter 40 . Controller CA sends a modulation signal SA to modulator MA that causes the modulator to impart to optical pulse P 1 a modulation randomly selected from a set of basis phase modulations as the optical pulse passes through the modulator. This forms a modulated optical pulse P 1 ′. Because of its polarization, modulated optical pulse P 1 ′ is outputted from beamsplitter 40 at output face 42 and travels over optical fiber section F 6 to telescope 50 A. Optical pulse P 1 ′ constitutes the quantum signal.
[0032] BOB's telescope 50 B is in optical communication with telescope 50 A and receives optical pulse P 1 ′. Optical pulse P 1 ′ is communicated to input face 201 of beamsplitter 200 via optical fiber section F 9 . Beamsplitter 200 splits modulated optical pulse P 1 ′ into two optical pulses P 1 ′- 1 and P 1 ′ 1 - 2 , which exit the beamsplitter at respective output faces 202 and 203 and travel over respective optical fiber sections F 7 and F 8 to respective beamsplitters 206 and 210 .
[0033] The role of classical optics layers 6 A and 6 B and RF communication layers 8 A and 8 B are discussed below in connection with the different example embodiments of the HAP-based QKD systems of the present invention.
[0034] Note that neither ALICE nor BOB include a Pockels cell. This is because it is undesirable to use a Pockels cell for quantum signal modulation due to the EMI it emits during modulation.
HAP QKD System
[0035] In an example embodiment of the present invention, Alice and Bob are used to form a HAP-based QKD system. Several different example embodiments of a HAP-based QKD system are set forth below.
FIRST EXAMPLE EMBODIMENT
[0036] FIG. 3 is a schematic diagram of an example embodiment of a HAP-based QKD system 200 that employs a HAP 300 , such as a zeppelin, as shown. HAP 300 includes a HAP controller 310 operably coupled to ALICE and that controls the position, speed and general operation of HAP 300 . ALICE is carried by HAP 300 , and BOB is ground-based. With reference to FIGS. 1 through 3 , quantum optics layers 4 A and 4 B are in free-space optical communication via telescopes 50 A and 50 B at ALICE and BOB, respectively, as discussed above. In an example embodiment, the quantum channel is transmitted at ˜1550 nanometers. Although the task of single photon detection is challenging at 1550 nm, this wavelength region is attractive due to lower background flux from diffused sunlight and compatibility with standard telecommunications equipment.
[0037] The classical optics communication layers 6 A and 6 B are in optical communication via sync-unit telescopes 114 A and 114 B and beacon-unit telescopes 124 A and 124 B. In an example embodiment, the beacon and/or classical/synchronization channels have a wavelength in the range from 700 nm to 850 nm. Sync units 110 A and 110 B and their corresponding telescopes 114 A and 114 B provide synchronization between ALICE and BOB via optical synchronization signals PS so that the SPDs can be gated to the expected arrival time of the quantum signals P 1 ′.
[0038] The distance between ALICE and BOB varies due to movement of HAP 300 . Further, changes in the optical path can occur due to temperature and pressure variations in the atmosphere, which affect the index of refraction profile of the optical path OP between ALICE and BOB. Optical path variations change the expected arrival time of the quantum signals. Accordingly, optical beacon signals PB sent between beacon units 120 A and 120 B via their respective telescopes 124 A and 124 B are used to establish the optical path distance OPD AB for the optical path OP between ALICE and BOB, e.g., for each quantum signal P 1 ′ transmitted. Information about the optical path distance OPD AB is provided to controller CA, which makes the corresponding adjustment to sync signals SO, SA, SD 1 , SD 2 , SD 3 , and SD 4 to account for changes in the optical path distance OPD AB .
[0039] In an example embodiment, sync units 110 A and 110 B and their corresponding telescopes 114 A and 114 B also serve as a classical communication channel between HAP and ground stations, e.g. for error correction and privacy amplification, via classical signals PC.
[0040] In an example embodiment, either ALICE or BOB can initiate a request for a QKD session. The request is sent through via the classical optics communication layers 6 A and 6 B, or via RF communication layers 8 A and 8 B. Once the request for QKD connection is confirmed by both stations, Alice starts a standard QKD process.
[0041] ALICE and BOB are in RF communication via RF communication layers 8 A and 8 B and RF signals 33 A and 33 B. The RF communication between ALICE and BOB allow for controllers CA and CB to communicate non-optically. This ability is particularly useful when the optical path OP between ALICE and BOB is obscured (e.g., by clouds) so that optical communication via the quantum optics layers 4 A and 4 B and/or via the classical optics communication layers 6 A and 6 B is difficult or impossible. RF communication via RF signals 33 A and 33 B is used, for example, to send instructions to the HAP controller 310 to change the position of HAP 300 so that optical communication can take place over optical path OP. In an example embodiment, RF signals 33 A and 33 B are also used to place ALICE and BOB in “standby” mode while communication over the classical and/or quantum optical communication channels is not available.
[0042] In an example embodiment, QKD system 200 runs the BB84 protocol with polarization encoding. ALICE has a delay line DL in optical fiber section F 3 that makes the arms of her Mach-Zehnder interferometer equal. Phase modulator MA provides the needed polarization rotation. This design avoids the use of Pockels cells, which as mentioned above, are not secure because of a pronounced EMI signature during modulation.
SECOND EXAMPLE EMBODIMENT
[0043] FIG. 4 is a schematic diagram illustrating a second example embodiment of a HAP-based QKD system 200 used to transfer quantum keys between QKD stations ALICE, BOB- 1 and BOB- 2 , wherein BOB- 1 and BOB- 2 at different locations L 1 and L 2 and ALICE resides in HAP 300 .
[0044] In one example, ALICE first establishes contact with BOB- 1 and then ALICE and BOB- 1 exchange quantum signals P 1 ′ to establish a first quantum key. ALICE and BOB- 2 then establish contact and exchange quantum signals to establish a second quantum key. ALICE then uses the second quantum key to encode and transmit the first quantum key to BOB- 2 so that BOB- 1 and BOB- 2 now share the same first quantum key. BOB- 1 and BOB- 2 can then transmit encoded messages using such commonly shared quantum keys.
[0045] In another example, ALICE has quantum keys stored in key bank 180 and uses the first and second quantum keys to encode and transmit stored keys to BOB- 1 and BOB- 2 , respectively. Again, this allows BOB- 1 and BOB- 2 to have a common set of secure keys.
[0046] Note that in the example embodiment of FIG. 4 , HAP 300 need not be stationary. Thus, if BOB- 1 and BOB- 2 are too far apart for HAP 300 to communicate directly with them both at the same time, HAP 300 moves from the vicinity of location L 1 to the vicinity of location L 2 and then established contact and communicates with BOB- 2 .
THIRD EXAMPLE EMBODIMENT
[0047] FIG. 5 is a schematic diagram of a third example embodiment of HAP-based QKD system 200 wherein HAP 300 includes both ALICE and BOB QKD stations. This allows for HAP 300 to serve as a platform for an ALICE-BOB relay station that provides for cascaded key transmission from BOB- 1 at location L 1 to BOB- 2 at location L 2 . The ALICE-BOB QKD stations can also communication with an ALICE ground station, as shown.
FOURTH EXAMPLE EMBODIMENT
[0048] FIG. 6 is a schematic diagram of a fourth example embodiment of a HAP-based QKD system 200 that employs entangled photons to perform QKD. HAP 300 includes a source 300 of entangled photons, and ALICE and BOB have receivers suitable for entangled-photon QKD, such as disclosed, for example, in U.S. Pat. No. 6,028,935 to Rarity, which patent is incorporated by reference herein.
FIFTH EXAMPLE EMBODIMENT
[0049] FIG. 7 is a schematic diagram of a fifth example embodiment of a HAP-based QKD system 200 that involves a spacecraft 340 that includes a QKD station BOB, as indicated by B. The QKD system 200 of FIG. 7 allows for a common key to be provided to a ground based QKD station and a space-based QKD station.
[0050] In this example embodiment, HAP 300 supports an ALICE, as indicated by A. A ground-based BOB- 1 establishes contact with ALICE A in HAP 300 and establishes a first quantum key between them, as described above. ALICE A then uses this key to encrypt and send BOB- 1 a key stored in key bank 180 . Next, QKD station A exchanges quantum signals and establishes a second quantum key with QKD station B in spacecraft 340 . QKD station A then uses this second key to encrypt and send B the same key provided to QKD station BOB- 1 . Thus, BOB- 1 and space-based QKD station B share a common key for secure communication.
[0051] This example embodiment is particularly useful because HAP 300 can be located at an altitude that allows for an unobstructed optical path to spacecraft 340 .
Advantages
[0052] A HAP-based\QKD system offers several key advantages over other QKD systems, and particularly QKD systems that rely on space-based platforms such a spacecraft and satellites. HAPs are much less expense to deploy and maintain than spacecraft and satellites. If there is a doubt about the security of a HAP, it can be brought back to the ground, inspected and redeployed in short order. HAPs are also quite mobile and can be steered or piloted to different locations as needed. HAPs can also fly or be positioned at different altitudes and so can stay below clouds or and otherwise avoid obstructions in the free-space optical path that cause optical signal attenuation. HAPs also offer a broad signal coverage area. For example, a HAP positioned in the stratosphere at an altitude of ˜20 km ensures nearly a 1000 km simultaneous link distance between ground-based QKD stations, which provides secure data communication coverage over an area about the size of New England. Further, the mobility of the HAP extends this signal coverage area. | Systems and methods for performing quantum key distribution (QKD) using one or more high-altitude platforms (HAPs) are disclosed. The system includes a second QKD station (Alice) supported by the HAP so as to be in free-space communication with the first QKD station (Bob) over an optical path (OP) via an optical quantum communication channel that carries quantum signals (P 1 ′), an optical synchronization channel that carries synchronization signals (PS) and optionally classical communication signals (PC), an optical beacon channel that carries beacon signals (PB), and a radio-frequency (RF) channel that carries RF signals. The beacon signals are used to detect changes in the optical path and correct the synchronization signals (PB) so as to gate the first and second SPD pairs to correspond to arrival times of the quantum signals at said first and second SPD pairs. The system does not require a Pockels cell for quantum signal modulation, thereby improving the security of the system. | 6 |
This application is a continuation of U.S. patent application Ser. No. 09/693,614, entitled “Copper CMP Flatness Monitor Using Grazing Incidence Interferometry,” filed on Oct. 20, 2000, now U.S. Pat. No. 6,806,966 which is a continuation of U.S. patent application Ser. No. 08/930,378, entitled “Apparatus and Method for Measuring Two Opposite Surfaces of a Body,” filed on Sep. 24, 1997, now U.S. Pat. No. 6,100,977, which is the U.S. National Phase Application of PCT/EP96/03381, filed on Aug. 1, 1996, now PCT Publication W097/27452, which claims priority based on German (DE) Patent 196 02 445.5, filed Jan. 24, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the art of optical inspection of specimens, such as semiconductor wafers and hard disk surfaces, and more specifically to a system for determining surface topographies in the nanometer range using optical techniques.
2. Description of the Related Art
Optical inspection techniques for specimens, such as semiconductor wafers, have assessed the relative flatness of specimen surfaces using various techniques. Surface flatness is a critical parameter used to determine the overall quality of a semiconductor wafer, and wafers having large irregular areas or small areas with radical height differences are undesirable.
For CMP (Chemical Mechanical Planarization) processed wafers, the starting material is a bare silicon wafer. Such a bare silicon wafer must be flat within certain tolerances regarding the height and spatial width of the flatness features.
Current tools available to measure wafer surface flatness include the “Magic Mirror” tool by Hologenix. The “Magic Mirror” operates by directing collimated light toward the wafer surface, wherein the collimated light source is angularly displaced from the wafer surface. The “Magic Mirror” system subsequently receives the reflected light, and the light received may be scattered toward or away from the detector. The “Magic Mirror” thereupon produces a two dimensional depiction of the surface of the observed semiconductor wafer, with associated light and/or dark areas depending on the type of defect. As can be appreciated, the “Magic Mirror” is a very subjective method of detecting surface contours. With different types of defects producing different optical effects, one cannot say for certain what type or size of defect is responsible for the bright or dark spot or area in the “Magic Mirror” depiction. Hence algorithms cannot conclusively provide areas of concern or threshold exceedance with reasonable degrees of certainty. The final two dimensional representation obtained from the “Magic Mirror” must be studied by an operator, and results depend on many uncontrollable factors.
Tools like the Magic Mirror can be used for flatness inspection of a bare wafer. However, for CMP processed wafer monitoring additional issues arise relating to the efficiency of the polishing, such as pitting and dishing of the patterned wafer surface. Magic mirror type tools are ineffective in addressing these types of anomalies.
A system addressing specimen flatness issues is the subject of current U.S. patent application Ser. No. 09/195,533, filed on Nov. 18, 1998, entitled “Detection System for Nanometer Scale Topographic Measurements of Reflective Surfaces” and developed by and assigned to KLA-Tencor Corporation, the assignee of the present application, provides a linear position array detector system which imparts light energy in a substantially normal orientation to a surface of a specimen, such as a semiconductor wafer, receives light energy from the specimen surface and monitors deviation of the retro beam from that expected. This system has particular advantages but requires a post processor to determine and fully compute the surface geometry for the entire specimen.
One device commonly used to measure the quality of the polishing of a CMP processed wafer is a profiler, much like a stylus on a record player, which directly contacts the semiconductor wafer surface. Such a system moves the semiconductor wafer and sensor relative to each other causing the sensor to linearly translate across the surface, thereby providing contact between the profiler and the entire surface. Movement of the profiler is recorded, and surface irregularities are detected when the profiler deflects beyond a threshold distance. The problems inherent in a profiler are at least twofold: first, a mechanical profiler contacting the wafer surface may itself produce surface irregularities beyond those present prior to the testing, and second, the time required to make accurate assessments of surface irregularities is extensive. For example, a full map of a single 200 mm wafer using a profiler may take between four and twelve hours.
A system is needed which diminishes the time required to perform surface scanning for contour differences and does not have the drawbacks inherent in the Magic mirror or profiler configurations. Further, it would be advantageous to provide a system which is less expensive than the KLA-Tencor normal incidence system and which can be used in examining less than the entire specimen surface quickly and efficiently. In particular, it would be desirable to have a system for determining specimen surface variations that would not risk damage to the specimen and would be quantitative in nature, thereby permitting contour quantification without ad hoc human review.
A further disadvantage of currently available flatness or contour measurement devices is that they stand separate from the production process and cannot be integrated into the process line. A developer or processing facility must first use the profiler or other device off line to inspect the surface of the specimen and subsequently place the specimen in the processing line for further inspection and processing.
It is therefore an object of the current invention to provide a system for determining the contours of portions of the surface of a specimen, such as a semiconductor wafer that can perform surface irregularity determination in less time and more cost effectively than systems previously known.
It is a further object of the current invention to provide a system for determining the contours of a wafer surface which does not increase the risk of damaging the wafer surface.
It is another object of the current invention to provide a system for inspecting the flatness or contour of a specimen that may be employed and integrated in the process line.
SUMMARY OF THE INVENTION
The present invention is a system and method for performing an in line inspection of a wafer or specimen using optical techniques. The wafer may be mounted in a vertical or horizontal orientation. Light energy is transmitted through a lens arrangement employing lenses having diameter smaller than the specimen, such as less than half the size of the specimen, arranged to cause light energy to strike the surface of the wafer and subsequently pass through a second collimating lens where detection and observation is performed.
The inventive system includes a low coherence light source that transmits light energy through a collimator, which collimates the light energy and directs the light energy to a diffraction grating. The diffraction grating splits the received beam into two separate first order beams. One first order beam is directed to the wafer surface, while the other beam is directed toward a flat reflective surface facing the wafer surface. Another diffraction grating is positioned to receive the two reflected first order beams and combine said beams toward a camera. The camera is specially designed to receive the signal provided and resolve the image of the wafer surface.
While the positive and negative first orders are preferably employed in the system as the test and reference arms, the gratings may be tilted to employ a different combination of orders as test and reference arms. Introduction of such a tilt may provide different combinations of orders used as test and reference arms, including zero order and higher order components. Further, the system may be arranged such that the angles of incidence on the surface vary, either by tilting the gratings or otherwise repositioning the components. Such variance may cause different orders of the components to strike the target surface and/or reference surface. Varying the incidence in this manner may in certain environments improve system resolution.
The light energy transmitted from the low coherence light source is dimensioned in conjunction with the collimator and diffraction grating to provide a narrow swath of light energy over a predetermined area of the wafer having a known pattern or set of characteristic features located thereon. Examination of a wafer to determine the overall quality of the wafer comprises a multiple point examination of the wafer, typically a five point inspection of known characteristic features on the specimen to determine the overall quality of the chemical-mechanical planarization process on the particular wafer. Further, the system provides for an areal examination of the entire field of view by rotation of the wafer in order to examine any location on the wafer. The system further has the ability to compare two or more locations on the wafer, such as the center of the wafer and the edge of the wafer, using a swath of light energy across the wafer surface. As wafer dimensions are on the order of 300 millimeters in diameter, the current system is directed to an examination of an area having dimension less than approximately 50 millimeters in width on the surface of the specimen. This less than approximately 50 millimeter wide area includes the salient features of the floor plan for a copper damascene CMP mask. The system disclosed herein transmits an approximately 50 millimeter wide swath or stripe of first order light energy onto the specimen and a similar swath onto the reflective surface facing the specimen. This narrow swath of light energy permits examination of particular features on the specimen and enables quantifying the quality of the CMP process without causing contact with the wafer and in a short amount of time. The present invention also permits a simple in-line examination procedure using a simple chuck and minimizes the need for ad hoc human review.
As may be appreciated, the current system transmits light energy at a relatively shallow angle, approximately 80 degrees from normal to the surface of the specimen, and thus the area of the wafer illuminated is on the order of six times larger than the dimension of the transmitted light energy. As a result of this 1:6 dimensioning, an improved camera arrangement is employed to resolve the image and accurately examine the data.
In order to measure certain anomalies created by the CMP process, the system must be capable of micrometer range spatial resolution. Thus the camera arrangement has zoom capability to accurately measure these imperfections.
These and other objects and advantages of the present invention will become apparent to those skilled in the art from the following detailed description of the invention and the accompanying drawings.
DESCRIPTION OF THE DRAWINGS
FIG. 1 illustrates a conceptual drawing of the current invention;
FIG. 2 presents the floor plan for a typical copper damascene CMP mask, including the standardized topography for each of the sections of a predetermined section of the mask;
FIG. 3 illustrates the general concept of the 6:1or 1:6 aspect ratio of the transmitted and received light energy to and from the surface of the specimen;
FIG. 4 presents the camera system or camera optics employed in the current invention;
FIG. 5 is a simplified drawing of the system from the wafer to the camera arrangement;
FIG. 6 presents a conceptual schematic representation of the components and optics necessary to perform the inventive imaging of a predetermined portion of a semiconductor wafer; and
FIG. 7 is a top view of the components of FIG. 4 and the optics showing the path of light energy.
DETAILED DESCRIPTION OF THE INVENTION
For a full understanding of the inventive system disclosed herein, it must first be appreciated that a specimen such as a semiconductor wafer may undergo a variety of processes and/or evaluations to determine the quality of the circuit located thereon. In most circumstances, a complete scan of the specimen is required to determine the quality of the specimen and the processing which has occurred. In certain limited circumstances, a subset of the entire wafer or specimen may be advantageous to determine the general quality of the wafer as opposed to the detailed quality of the individual circuits etched thereon. For purposes of this invention, the initial general scan comprising an evaluation of a subset of the specimen surface is differentiated from a complete scan of the entire surface of the specimen. The present invention is primarily directed to the former rather than the latter.
FIG. 1 illustrates a conceptual drawing of the current invention. As shown in FIG. 1 , a low coherence light source 101 is employed to generate a low coherence light beam 102 . The low coherence light beam strikes a collimator 103 which collimates the light beam and transmits light energy to a first transmission grating 104 . First transmission grating 104 splits the received light energy into multiple order components, including but not limited to a zero order component and at least one first order component. The zero order component may optionally be blocked in the arrangement shown in FIG. 1 . As shown in FIG. 1 , first transmission grating 104 generates a positive and negative first order component that is directed in a preferential orientation toward a reference mirror 105 and the wafer or specimen 110 . The first order components strike the reference mirror 105 and the specimen 110 and are directed toward second transmission grating 106 , which combines the two first order components and directs the resultant light energy toward decollimator 107 . Decollimator 107 collects the light energy and decollimates the energy. Energy transmitted by decollimator 107 is received by camera optics 108 and transmitted to imaging sensor 109 , which may be a CCD.
While the positive and negative first order components are preferably used as the test and reference arms of the interferometer, and the zero order blocked or optimized for zero intensity, the system may be configured or operated such that a tilt of the gratings 104 and 106 causes varying orders of the light energy to strike the target surface and/or the reference surface. Tilting the gratings 104 and 106 may in certain environments provide enhanced imaging and resolution. Alternately, the system may be varied to provide different angles of incidence on the reference surface or the target surface. Altered angles of incidence may provide enhanced resolution in certain conditions, and may be used to cause zero, first, or higher order light components to strike the reference or target surface.
The planarization process for a Copper CMP (Chemical Mechanical Planarization) processed wafer requires first subjecting an unfinished wafer to the process and subsequently examining the wafer for defects. Different effects from the CMP process provide different anomalies on the surface of the specimen. For example, certain processes can cause global planarization anomalies, with differences in surface height measurable only by determining heights over large areas of the wafer. Smaller sections of the specimen may suffer from field local erosion, wherein small areas are lower than other proximate areas. Finally, lines formed of metal can wear away during the CMP process, resulting in local line dishing and requiring higher spatial resolution to determine the defects.
In this environment, it is advantageous to examine less than the entire surface of the wafer to determine the anomalies present on a particular wafer that result from the CMP process. Typical scanning of the surface involves a multiple point inspection, typically a five point inspection, of the surface of the specimen to determine as many anomalies as possible with the least amount of points examined as possible.
In operation, the device of FIG. 1 measures a single side of the specimen 110 . The aperture of the low coherence light source is reduced to smaller than 50 by 50 millimeters to permit measurement of a 300 by less than 50 millimeter striped area on a 300 millimeter wafer. This less than 50 millimeter wide area covers an area large enough to perform a scan of a Copper Damascene CMP mask, as well as one or more masks at different locations on the wafer. By rotating the CMP processed wafer, the use of the swath of light energy described herein to illuminate the specimen from edge to edge. The ability to examine the wafer from at least the center of the wafer to the edge thereof permits examination of any point on the wafer by simply rotating the wafer such that the point of interest is within the swath of light energy. Rotation permits a comparison between two or more points on the surface of the CMP mask.
A floor plan for a typical Copper Damascene CMIP mask is presented in FIG. 2 . As shown in FIG. 2 , various “pitch” sections, or blocks, of the mask are filled with vertical lines ranging from 10 micrometers to 200 micrometers at a fixed density of 50 per cent. In the “density” blocks, each block has a specified density with vertical lines at fixed pitches of 3 micrometers and 5 micrometers. Density is equal to copper linewidth divided by the pitch. Lines in FIG. 2 shown between the various sections represent boundaries between the sections. The three blocks S1D, S2D, and S3D provide a continuity test on different linewidths having fixed linespace. Further, the S1D, S2D, and S3D blocks serve as density blocks for minimum and fine pitch values, i.e. 0.3 5/0.35. The S2 and S3 blocks are employed for a continuity test. SC1 is a combined serpentine and comb structure. C2 and C3 are comb-like structures for non-shorting (among different copper lines) testing. Each structure is 0.775 millimeters in width.
The purpose of the floor plan of FIG. 2 is to provide a standard area wherein the effects of global planarization, local erosion, and local dishing may be assessed. The varying pitches, wire densities, linewidths, and line spaces provide a variety of situations a CMP processed wafer may encounter. Thus, observation of a floor plan as shown in FIG. 2 presents a significant baseline for determining the errors present on the entire wafer due to the CMP process. As shown in FIG. 2 , a typical floor plan is approximately a 15 millimeter square, with bounded sections ranging up to 3 millimeters square. These dimensions afford a baseline for examination by inspecting a portion of the wafer surface rather than the entire surface. Hence the current device affords scanning of the wafer including a scan of the copper CMIP floor plan of FIG. 2 . From the system of FIG. 1 , the light energy transmitted onto the surface of the specimen is an approximately 300 millimeter by less than 50 millimeter swath, an area large enough to characterize and monitor the effects of the planarization process. A smaller area than 300 by 50 millimeters may be sufficient, such as one covering the floor plan of FIG. 2 , i.e. a stripe or swath in excess of 15 millimeters in width. Using the system illustrated in FIG. 1 , the stripe is measured in a single step (imaging) and no scanning is required. The specimen may be oriented in either a vertical or a horizontal manner.
In operation, the wafer or specimen is held either vertically or horizontally during measurement. The diverging light of the low coherence light source is collimated and diffracted by the transmission grating into plus and minus first order components, among other components. One order illuminates the specimen, while the other order illuminates a plano reference mirror substantially parallel to the wafer surface and at a distance to the wafer which provides a common path length for both the positive and negative first orders. The suggested angle of incidence is approximately 80 degrees on both the is measured from normal to the wafer or reference surface down to the light beam. Other grazing angles may be employed while remaining within the scope of this invention.
After reflecting both orders from the surfaces, the two first order components are recombined to the zero order by the second transmission grating. The decollimator and lens system image the swath or stripe observed on a high resolution CCD imaging sensor. The system employs phase shifting to acquire height information, and digital image processing to calculate phase information. The system unwraps the phase and filters the resultant height information from the wafer topography to evaluate local and global flatness uniformity for different spatial wavelengths. In this configuration, grazing incidence enlarges the dynamic measuring range necessary to measure large areas on bowed wafers. Low coherence reduces noise problems from multiple reflected orders due to different diffraction patterns on wafers. The second diffraction grating used to recombine the positive and negative first order components also acts to filter out the pattern generated diffraction orders.
In the system illustrated in FIG. 1 , reference surfaces and specimen surfaces are positioned such that the reference wave fronts and specimen wave fronts travel the same path length. Phase shifting may be established by moving the reference surfaces, the diffraction gratings, or the light source. Thus the overall effect of the system illustrated in FIG. 1 is to decrease the required spatial coherence between the reference wave fronts and the specimen wave fronts.
The camera system or camera optics 108 is an anamorphic imaging system having an aspect ratio of on the order of 2:1. In essence, the wafer in the configuration illustrated optically appears as a tilted object, and in the arrangement shown has an elliptical projection ratio of approximately 6:1. The camera system used should preferably resolve this elliptical projection ratio into an image having an aspect ratio closer to 1:1. Maintaining the aspect ratio of 6:1 can prevent detection of relatively significant magnitude. An illustration of the 6:1 relationship in the projection of the swath or stripe of light energy is presented in FIG. 3 , wherein specimen or wafer 110 receives and reflects light energy.
The overall configuration of the anamorphic imaging system used in the system disclosed herein is shown in FIG. 4 . From FIG. 4 , the projection of the image has an elliptical aspect ratio of 6:1. The anamorphic imaging system 401 receives the elliptical image 402 and conveys the image to a viewing location, such as a CCD (Charged Coupled Device) such that the received image 403 has an aspect ratio of 2:1. This ratio provides the maximum utilization of a square image when imaging each of the wafer stitching regions. Different anamorphic imaging arrangements may be employed while still within the scope of the current invention; the intention of the anamorphic system and function thereof is to provide a sufficient image based on the surfaces being scanned and the size and quality of defects expected, as well as the resolution capability of the overall system.
In order to measure certain anomalies created by the CMP process, such as dishing, the system has micrometer range spatial resolution. Dishing anomalies are measured over roughly two millimeters within multiple fields of varying line densities, thus requiring this micrometer range spatial resolution. The camera system 108 therefore has zoom capability to accurately measure these dishing attributes. Using a zoom capability and therefore reducing the field of view require an x/y translation of the specimen, an x/y translation of the interferometer, or an x/y translation of the imaging system. This translation of components permits enhanced dishing measurement using the zoom capability of the camera system 108 . The wafer is translated by mechanical or automated means known to those of skill in the art, while the interferometer and imaging system translation is performed by releasing, moving, and fixing the position of the appropriate components, or by other translation procedures and devices known to those skilled in the art.
A simplified drawing of the system from the wafer to the camera arrangement is presented in FIG. 5 . FIG. 5 is not to scale. From FIG. 5 , wafer or specimen 110 reflects the light energy toward second diffraction grating 501 , which passes light to collimator 502 and to a camera arrangement 503 . Camera arrangement 503 comprises seven imaging lenses used to resolve the 6:1 image received into a 2:1 image for transmission to imaging sensor or CCD 109 . Any lensing arrangement capable of producing this function is acceptable, and the camera arrangement 503 is therefore not limited to that illustrated in FIG. 5 .
Imaging of the specimen is generally performed in accordance with PCT Application PCT/EP/03881 to Dieter Mueller, currently assigned to the KLA-Tencor Corporation, the assignee of the current application. The entirety of PCT/EP/03881 is incorporated herein by reference. This imaging arrangement is illustrated in FIGS. 6 and 7 , and is employed in conjunction with the arrangement illustrated and described with respect to FIG. 1 herein. FIGS. 6 and 7 , as well as FIG. 1 , are not to scale. As shown in FIGS. 6 and 7 , the light energy directing apparatus employed in the current invention comprises a light source in the form of a low coherence laser 601 . The light emitted from the laser 601 is conducted through a beam waveguide 602 . The light produced by the laser 601 emerges at an end 603 of the beam waveguides 602 so that the end 603 acts as a punctual light source. The emerging light strikes a deviation mirror 604 wherefrom it is redirected onto a collimation mirror 607 in the form of a parabolic mirror by two further deviation mirrors 605 and 606 . Deviation mirrors 605 and 606 are oriented at an angle of 90° relative to each other. The parallel light beam P reflected from the parabolic mirror 607 reaches a beam splitter 608 through the two deviation mirrors 605 and 606 .
The beam splitter 608 is formed as a first diffraction grating. The beam splitter 608 as shown is arranged in the apparatus in a vertical direction and the parallel light beam P strikes the diffraction grating in a perpendicular direction. As may be appreciated by those of skill in the art, the specimen may be oriented in the horizontal direction, thereby requiring a simple re-orientation of the optical components.
A beam collector 610 in the form of a second diffraction grating is disposed from the first diffraction grating 608 and parallel thereto. Behind the beam collector 610 is located a decollimation lens and the light beam leaving the decollimation lens is deflected and focused onto a CCD camera 616 , through deviation mirrors 612 , 613 , and 614 , and through lens 615 .
In the arrangement shown, the beam splitter 608 is supported transversely to the optical axis and further comprises a piezoelectric actuating element 617 for shifting the phase of the parallel light beam P by displacing the diffraction grating.
As noted, in order to provide for inspection of a portion of the wafer surface in-line during the overall specimen inspection process, the orientation of the system may differ from that shown in FIGS. 6 and 7 . For example, it may be preferable to provide a horizontal orientation of the wafer to reduce the need for human interaction. Alternately, as shown in FIGS. 6 and 7 , the specimen may be vertically oriented. In either orientation, the reference mirror 105 of FIG. 1 or 651 of FIG. 6 must be provided substantially parallel to the wafer surface and providing a common path length between the transmission gratings.
To facilitate the inspection, a holding device 630 may be provided between the first diffraction grating and the second diffraction grating. A wafer or specimen 609 to be measured may be held on the holding device 630 such that both plane surfaces 631 and 632 are arranged in vertical direction parallel to the light beam P. The wafer 609 is supported by the support post substantially at its vertical edge 633 only so that the surface 632 is not substantially contacted by the support post and are freely accessible to the interferometric measurement.
Moreover, an optional receiving device ( 630 , 625 ) may be provided for measuring the wafer 609 . This receiving device ( 630 , 625 ) provides for arrangement of the wafer in line in the system. The wafer can be inserted into the receiving device in a horizontal position. By means of a tilting device 626 the wafer 609 may be tilted from its horizontal position into the vertical measuring position, and the wafer 609 may be transferred, by means of a positionable traveller into the light path between the first diffraction grating and the second diffraction grating so that the surfaces 609 and 632 to be measured are aligned substantially parallel to the undiffracted light beam P and in a substantially vertical direction.
In operation the wafer or specimen 609 to be measured may be first inserted into the wafer receiving device 625 . The surfaces 631 and 632 are horizontally arranged. By means of the tilting device and of the traveller 619 the wafer to be measured is brought into the holding device 630 where it is arranged so that the specimen 609 is vertically oriented. A diffraction of the parallel light beam P striking the first diffraction grating 608 of the beam splitter produces partial light beam or narrow swath or stripe A, whereby the first order component of the partial light beam A having a positive diffraction angle strikes one surface 632 of the wafer 609 and is reflected. The first order component of partial light beam A strikes the reflective surface or flat 651 . The 0-th diffraction order of the parallel light beam P passes through the first diffraction grating 608 and is not reflected at the surface 632 of the wafer 609 . This partial light beam P serves as a reference beam for interference with the reflected wave fronts of beam A. The 0-th order beam is preferably blocked by blocking surface 653 . In the second diffraction grating 610 , the beam collector and the reflected first order components of partial light beam A is combined with the reference beam P and focused, in the form of partial light beam A+P onto the focal planes of the CCD camera 616 through decollimation lens 611 and deviation mirrors 612 , 613 and 614 as well as positive lens 615 .
During the exposure of the surfaces the phase of the parallel light beam P is repeatedly shifted by multiples of 90° and 120° by displacing the diffraction grating. This produces phase shifted interference patterns. The defined shift of the interference phase produced by the phase shifter 617 is evaluated to determine whether there is a protuberance or a depression in the measured surface 631 .
It should be noted that in the manner illustrated in the preferred embodiment and in general the wafer specimen is able to be rotated such that data may be acquired for any location on the specimen. While one particular wafer holding apparatus is illustrated, it is to be understood that any type of wafer holding device is generally acceptable that provides for relatively simple rotation and data acquisition. Using such a wafer holding apparatus, the swath of light can cover and examine a strip extending at least from the center of the specimen to the edge of the specimen. Use of the term “center” means a point approximately central to a generally round specimen, or at a non-edge point in a non-circular specimen. The system and method disclosed herein provide for examination of global planarization, erosion, and dishing on the CMP processed wafer surface. The system and method can be integrated into the CMP process line, and various CMP processed wafers are successfully examined using the invention described herein, including but not limited to unpatterned wafers with film, patterned test wafer with test mask, patterned production wafer with combination of product and test mask, and patterned production wafers free of test masks.
While the invention has been described in connection with specific embodiments thereof, it will be understood that the invention is capable of further modifications. This application is intended to cover any variations, uses or adaptations of the invention following, in general, the principles of the invention, and including such departures from the present disclosure as come within known and customary practice within the art to which the invention pertains. | A system and method for in-line inspection of specimens such as semiconductor wafers is provided. The system provides scanning of sections of specimens having predetermined standardized characteristics using a diffraction grating that widens and passes nth order (n>0) wave fronts to the specimen surface and a reflective surface for the transmitted light beam. Light energy is transmitted in a narrow swath across the portion of the surface having the standardized features. The wavefronts are combined using a second diffraction grating and passed to a camera system having a desired aspect ratio. | 6 |
BACKGROUND
Islet Isolation
The insulin producing tissue of the pancreas, the islets of Langerhans, constitutes between about one and two percent of the mass of the pancreas. The isolation of the islets from the remainder of the pancreatic tissue is desirable for laboratory purposes and for transplantation purposes. Transplantation of islets is looked to as a possible treatment for diabetes. Transplanting islets rather than an intact pancreas or pancreatic segments offers several advantages, including the ease of transplantation, the possibility of in vitro treatment to prevent rejection without immunosuppression, the elimination of the pancreatic exocrine function (the secretion of digestive substances from the host tissue), the possibility of cryopreservation of the tissue for subsequent use, and the possibility of xenografts.
In an early method of islet separation, chopped pancreatic fragments are mixed with collagenase and incubated at 37° C. (reviewed in Scharp, World Journal of Surgery 8:143-151 (1984)). The collagenase breaks down or digests the pancreatic tissue, freeing the islets. The collagenase also acts on the islets, so that the islets released early in the process are broken down into single cells. If the process is stopped to protect the islets released early, many islets remain trapped in pancreatic fragments. Therefore only a fraction of the available intact islets are released by this method. This process is particularly ineffective for the isolation of islets from the pancreata of large animals such as humans, dogs, or pigs.
Laboratory islet isolation from rodent pancreata was greatly improved by the discovery that mechanical distension of rodent pancreata increased islet yield by causing mechanical separation of islets from the pancreas tissue. After distension the pancreas is chopped for coIlagenase digestion. The beneficial effect of this same type of mechanical distension has also been noticed in large animals.
Horaguchi and Merrell, Diabetes 30:455-58 (1982) developed a method for perfusing the dog pancreas with collagenase via the pancreatic duct. Subsequently, a process involving ductal distension of the pancreas with a solution containing collagenase was developed (U.S. Pat. No. 4,868,121; incorporated herein by reference). Inflation or distension of the pancreas is believed to cause some mechanical rupturing of the exocrine tissue or partial separation of the islets from the exocrine tissue, making subsequent collagenase digestion easier.
Sonication
Sound waves have been used in the past to aggregate cells and to disrupt cells. For example, ultrasound has recently been used to aggregate cells as a purification procedure. Kilburn, DG, et al., "Enhanced sedimentation of mammalian cells following acoustic aggregation," Biotechnol.Bioeng. 34:559-62 (1989). In this procedure, cells which are not sufficiently heavy to precipitate out of solution are caused to aggregate by exposure to ultrasound. The aggregates then precipitate out of the solution. This procedure uses a standing wave to aggregate the cells, and the procedure is performed in an echo chamber to create and maintain the standing wave.
Ultrasound has also long been used to disrupt cells. For example, exposure of cells to ultrasound is used to lyse the cells to isolate the nucleic acid contained inside. Crouse, CA, et al., "Extraction of DNA from forensic-type sexual assault specimens using simple, rapid sonication procedures" BioTechniques 15:641-42,644-48 (1993). This procedure uses very concentrated sound waves to disrupt the cell structure. The ultrasonic field is applied at a localized spot, such as a microtip of an emitter.
SUMMARY OF THE INVENTION
The present invention is an improvement on the process for isolating cells, such as islets of Langerhans, which incorporates sonication of the organ, such as the pancreas, as a method for dissociating the cells from other non-desired tissue. The inventors have discovered that sonication of the pancreas in conjunction with collagenase treatment results in a high degree of dissociation of the islet cells that maintain a high degree of integrity. The invention can be applied to the isolation of specific cell types from many different types of organs.
DETAILED DESCRIPTION OF THE INVENTION
The invention is an improved method for the isolation of specific viable cell types from surrounding organ tissue. The technique has specifically been applied to the isolation of islets of Langerhans cells from a pig pancreas as described below in the preferred embodiment. However, the invention is also applicable to the isolation of cell types from other organs and other animals (e.g., cells from organs from transgenic animals, islets from human pancreata). Other potential applications include the isolation of medullary cells from adrenal glands, and the isolation of hepatocytes from liver to be used, for example, as bioartificial liver systems. The organ is harvested and prepared as necessary, such as by removal of undesired segregated tissue or cells. The invention relies on the use of sound waves to accelerate tissue dissociation. The cells released from the dissociated tissue remain intact and viable, allowing separation of desired cells from unwanted tissue. Thus, this invention differs from the prior art wherein cells are either aggregated or disrupted. Implementation of the invention entails three steps.
(1) Treatment of the organ with tissue dissociating agents to release specific cell types from the surrounding organ tissue.
Tissue dissociating agents will typically include tissue degrading enzymes such as collagenase, trypsin, neutral protease or dispase, and other proteolytic enzymes, with the preferred embodiment demonstrating the use of collagenase. However, the tissue dissociating agents are not necessarily limited to enzymes. Other examples of tissue dissociating agents are chelating agents for the dissociation of fetal tissue. The length of time required for treatment with dissociating agents will vary depending on the type of the agent, the concentration of agent, and the temperature at which treatment is conducted. Treatment is allowed to proceed until a sufficient amount of tissue has dissociated without causing undue damage to released cells or cellular aggregates. Preferably at least 40%, more preferably at least 75%, and most preferably at least 90% of the tissue is dissociated, while less than 50%, more preferably less than 25%, and most preferably less than 10% of the cells are functionally damaged by treatment with the dissociating agents.
The preferred embodiment below describes the treatment of a pancreas via ductal distension, a method fully described in U.S. Pat. No. 4,868,121. That is a method in which the tissue dissociating effect of the treatment agent is enhanced by injection of the agent into the pancreas to cause tension that results in some mechanical rupturing of the exocrine tissue or partial separation of the islets from the exocrine tissue. However, the invention is not limited to this form of treatment. Other possible types of the treatment would include chopping the organ smaller into pieces and incubation with a tissue dissociating agent, or use of a dissociating agent with mechanical agitation such as incubation of the organ with marbles in a shaking container. In the preferred embodiment described below, enzyme treatment and sonication occur simultaneously.
(2) Sonication of the organ tissue to further enhance dissociation of the cells of interest.
The sonication step as described in the preferred embodiment was accomplished with a sonicating waterbath. However, it should be appreciated that other types of sonication methods could also be used. These would include acoustic horns, piezo-electric crystals, or any other method of generating stable sound waves, such as with sonication probes. In the preferred embodiment described below, sonication was conducted at about 43 kHz for approximately 20 minutes. Under approximately these same conditions, a sonication frequency of between about 40 kHz to 50 kHz is likely to be equally effective. However, a fairly wide range of frequencies, from subaudio to ultrasound (between about 7 Hz to 40 MHz, preferably between 7 Hz and 20 MHz) would be expected to give sound-enhanced tissue dissociation. Additionally, variations in the type of sonication include pulsing versus continuous sonication.
The sound waves created by the sound source must be at sufficiently low power so as not to disrupt the cells being isolated. The sonication source is run at a power level of between 10 -4 and about 10 watts/cm 2 . See "Biological Effects of Ultrasound: Mechanisms and Clinical Implications," National Council on Radiation Protection and Measurements (NCRP) Report No. 74, NCRP Scientific Committee No. 66: Wesley L. Nyborg, chairman; 1983; NCRP, Bethesda, Md. The sonicating water bath discussed above works at about 0.9 watt/cm 2 .
The tissue to be sonicated is present in a container which will hold the tissue and dissociated cells in a fluid and which is transparent to ultrasound waves. To avoid contamination of the tissue and cells, a closed container is preferred. Additionally, use of a light-transparent container will allow visual monitoring of the progress of dissociation. Further, use of a malleable container will allow tactile monitoring. In the preferred embodiment, a self-sealing polyethylene bag is used as the container for the organ that is placed in the sonicating water bath. Other types of enclosed malleable containers could also be used, or other containers such as a plastic beaker. The frequency and power of the sonication can be adjusted to accommodate significant changes in the type of container, the volume of buffer, or in the mass of material being sonicated.
Further, the conditions for sonication are such that a standing wave is not created. In the preferred embodiment described herein, the chamber of the sonicating water bath has rounded edges so as not to create a standing wave. Additionally, presence of the irregularly shaped, acoustically dense organ or tissue in the device impedes the production of a standing wave. Thus, according to the invention, the device for delivery of the sound waves, in combination with the tissue or organ to which the sound waves are being applied, are preferably configured to avoid the production of a standing wave.
It should be appreciated that the invention encompasses the use of these steps in other orders, such as partially overlapping of steps one and two, or tissue digestion prior to sonication.
(3) Separation of the dissociated cells from other organ tissue.
Finally, once the cells of interest have become dissociated from the surrounding organ tissue by treatment with dissociating agents and sonication, they must be separated from the other organ tissue. There are a wide variety of techniques that can be used to accomplish this step. These include various techniques for mechanical disruption of the tissue such as aspiration through needles, maceration, and/or filtration. Such techniques for mechanical disruption are preferably accompanied by a concentration/purification step such as either centrifugation or use of a density gradient flush-out to separate the desired cells from the remaining tissue when the cells have a different density. Islets can be separated in this manner from other denser acinar tissue. The islet cells are then typically further purified using standard density gradient methods such as Percoll® (a colloidal PVP coated silica, available from Sigma) or Ficoll® (a non-ionic synthetic polymer of sucrose, available from Sigma) gradients. See Ballinger, WF and Lacy, PE, "Transplantation of Intact Pancreatic Islets in Rats," Surgery 72:175-186 (1972), which is incorporated herein by reference.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Isolation of Islets of Langerhans Cells From a Pig Pancreas
The pancreas is removed from the pig carcass, preferably within 10 minutes after the pig is killed. This is accomplished by cutting across the neck of the pancreas to separate the splenic and non-splenic lobes. Preferably only the splenic lobe is used for islet isolation. External fat, connective tissue and blood vessels are trimmed from the pancreas. The pancreas is placed in cold physiologic solution supplemented with 10% horse serum, such as EuroCollins, and maintained preferably at about 4° C. for preservation. The pancreas may be stored in this manner for as long as 4-6 hours prior to the islet isolation process. If the pancreas is held at a higher temperature, the pancreas should be used in a shorter period of time to avoid tissue and cellular degradation. The pancreas can be partially distended by infusion of cold physiologic solution supplemented with 10% horse serum immediately upon removal from the animal. For example, 60 mls. of Eurocollins or M199 supplemented media can be inserted through the pancreatic duct via a catheter prior to placement of the organ in the bath for storage or transport.
The splenic lobe is cannulated, preferably with a 20 gauge angiocatheter inserted into the pancreatic duct, and sutured in place. A collagenase (Boehringer Mannheim) solution containing between about 0.5 to 6.0 mg/ml (2 mg/ml is preferred) collagenase in physiologic solution (same as above) is prepared and preheated to a temperature between about 20° C. and 38° C. (37° C. is preferred). The solution is injected into the pancreatic duct of the pancreas via the angiocatheter to inflate and distend the pancreas, using between about 0.5 to 3.0 mls of solution per gram of organ (1.5 to 2 mls of solution per gram of organ is preferred). Leaks are sutured or clamped, such as with a hemostat.
The inflated pancreas is placed in a self-sealing polyethylene bag (Ziploc®) containing approximately 100 ml. of collagenase solution similar to that injected into the pancreatic duct. The self-sealing bag is sealed after expelling most of the air from the container, and the container is placed in an ultrasonic water bath, preheated and maintained at a temperature between about 20° C. and 38° C. (37° C. is preferred). The ultrasound is turned on at a frequency of about 43 kHz, and the bag is allowed to incubate with occasional agitation and visual inspection to observe the digestion process. After about 10 minutes, when the organ begins to acquire a "cracked appearance," the organ is removed from the water bath and the excess collagenase solution is drained and replaced with an equal volume of fresh warmed collagenase solution. By "cracked appearance" is meant that the lobes appear to subdivide into smaller, distinguishable acinar structures. The organ is then returned to the ultrasonic water bath and allowed to incubate for approximately 10 to 15 more minutes with occasional agitation and visual inspection to observe the digestion process. The sonication in this preferred embodiment is in a Fischer Scientific Solid State Ultrasonic FS28 water bath, with a sonication frequency of approximately 43 kHz.
At the end-point of the digestion, the organ is removed from the water bath and placed on a horizontal plate shaker, preferably with a ribbed surface. Shaking is initiated and the organ is gently dispersed in the bag by pressing the organ against the ribbed surface of the plate shaker using a light finger pressure. The tissue is poured through a stainless steel screen (nominal mesh size of 350-500 μm) and collected in a stainless steel pan partially filled with rinse medium, and further washed with approximately 4 liters of 10% horse serum supplemented, modified M199 with an additional 20 mM CaCl 2 . Alternatively, the excess fluid can be decanted from the settled tissue in the bag, followed by resuspension of the tissue in a large volume of chilled physiologic medium inside the bag. The fluid and tissue can then be poured through the screen.
The tissue fragments collected in the pan are transferred to a collection vessel stored on ice. The process of rinsing and sieving tissue fragments away from the digested organ on the screen is continued until no further tissue fragments are released (approximately 10 minutes). Typically about 10-60% of the initial organ mass remains as undigested tissue.
The islet cells are then typically further purified using standard density gradient methods such as Percoll®or Ficoll®gradients (Scharp et al., 1987, Surgery 102:869-79). For example, the pooled islets are suspended in Ficoll®plus sodium diatrizoate (Sigma) at a density of 1.120 gm/ml and further purified and concentrated by density gradient centrifugation through a 1.060 to 1.180 Ficoll®/sodium diatrizoate gradient. This process typically yields between 500 to 2000 islet equivalent numbers per gram of organ mass, with purities and viabilities greater than 75%.
Table 1 shows islet yield from five different isolations utilizing the process of the invention. Pig pancreases were treated as described above. Islets were tested for viability and purity. Viability averaged 82%; purity averaged 96%.
TABLE 1__________________________________________________________________________ Pre-Purification Post-Purification Equivalent Islet Equivalent IsletLot % Pre-Purification Number Post-Purification NumberNumberDigested Islet Number (EIN) Islet Number (EIN) Viability Purity__________________________________________________________________________5009-00151 156,240 41,244 119,280 36,053 80 995011-00361 ND N/A 170,246 81,133 52 995012-00253 278,880 77,448 336,560 152,611 90 825017-00129 130,480 38,528 47,040 46,497 100 1005018-00334 178,080 49,194 113,680 51,033 87 98__________________________________________________________________________
"Percent Digested" is the ratio of (initial organ mass less remaining organ mass)/(initial organ mass). "Islet Number" refers to the number of cell clusters stained with DTZ (dithiozone), a zinc-binding dye which detects insulin. "Equivalent Islet Number," or "EIN," provides a volume corrected number of full sized islets represented by the stained clusters. EINs can be compared for determining maintenance or breakdown of original islet structure and for determining volume of islets before and after the procedure.
Viability is measured by fluorescein diacetate and ethidium bromide staining. The fluorescein diacetate stains living cells, while the ethidium bromide detects non-living cells. Purity is measured by DTZ binding by counting the positively stained cells divided by total particles in a particular volume.
Three thousand EIN each from lot numbers 5017-001 and 5018-003 were implanted into STZ-diabetic athymic mice. These islets were able to reduce blood glucose levels from greater than 500 mg/dl to less than 200 mg/dl in both cases. Thus, the isolated islets are functional--both glucose responsive and insulin producing.
Table 2 shows insulin content of islets isolated in three batches by the methods of the invention.
TABLE 2______________________________________ Insulin Content per isletLot Number (ng/islet)______________________________________NP097-4320-005 2.2NP097-4361-001 11.0NP097-5005-001 11.7______________________________________
Variations of the elements of the invention will be apparent to those skilled in the art, and it is intended that this invention be limited only by the scope of the appended claims. | A method for isolating specific viable cell types from surrounding organ tissue is provided. The method entails the use of sonication in conjunction with tissue dissociating agents to free the cells of interest. A specific application of the method is the isolation of the insulin producing tissue of the pancreas, the islets of Langerhans. The method results in a high yield of islets that maintain a high level of viability. | 0 |
FIELD OF THE INVENTION
[0001] The present invention relates to products to freshen laundry.
BACKGROUND OF THE INVENTION
[0002] There is a segment of consumers that prefer a strong perfume scent to their laundry. These so called “scent seekers” will often over dose laundry products such as laundry detergent and fabric softener to provide the desired freshness to their laundry. There is a need to provide a perfume scent additive product to consumer that will provide freshness to laundry. Such scent additive needs to be able to be applied by the consumer, independent of other laundry products, to achieve the desired scent level in a cost effective manner.
SUMMARY OF THE INVENTION
[0003] An embodiment of the invention can be a composition consisting essentially of: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; (b) from about 2% to about 12% by weight of the composition free perfume; and (c) from about 2% to about 12% by weight of the composition of friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; wherein the composition is shaped in a pastille having a mass from about 0.95 mg to about 2 g.
[0004] An additional embodiment of the invention can be a unit dose of a fabric treatment composition comprising a plurality of pastilles, wherein each pastille comprises: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; (b) from about 2% to about 12% by weight of the composition free perfume; and (c) from about 2% to about 12% by weight of the composition of friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; wherein each pastille has a mass from about 0.95 mg to about 2 g; and wherein the plurality of pastilles has a mass from about 13 g to about 27 g to comprise the unit dose.
[0005] An additional embodiment of the invention can be a composition consisting essentially of: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; and (b) from about 9% to about 20 wt % of friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; wherein the composition is essentially free of free perfume; and wherein the composition is shaped in a pastille having a mass from about 0.95 mg to about 2 g.
[0006] An additional embodiment of the invention can be a composition consisting essentially of: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; and (b) from about 9% to about 20% by weight of the composition free perfume; wherein the composition is essentially free of a perfume carrier; and wherein the composition is shaped in a pastille having a mass from about 0.95 mg to about 2 g.
[0007] An additional embodiment of the invention can be a method of making a composition comprising the steps of: providing a viscous material having a glass transition temperature, the viscous material comprising: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; (b) from about 2% to about 12% by weight of the composition free perfume; and (c) from about 2% to about 12% by weight of the composition of perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; providing the viscous material at a processing temperature less than about 20 degrees Celsius higher than the glass transition temperature; and passing the viscous material through small openings and onto a moving conveyor surface upon which the viscous material is cooled below the glass transition temperature to form a plurality of pastilles.
BRIEF DESCRIPTION OF THE DRAWING
[0008] FIG. 1 is a schematic of a pastillation apparatus.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The compositions of the present invention may comprise: polyethylene glycol; free perfume and/or perfume microcapsules; and optionally a dye. In one embodiment, the composition is essentially free of detergent surfactants and/or fabric softening actives.
[0010] Polyethylene Glycol (PEG)
[0011] Polyethylene glycol (PEG) has a relatively low cost, may be formed into many different shapes and sizes, minimizes free perfume diffusion, and dissolves well in water. PEG comes in various molecular weights. A suitable molecular weight range of PEG for the purposes of freshening laundry includes from about 3,000 to about 13,000, from about 4,000 to about 12,000, alternatively from about 5,000 to about 11,000, alternatively from about 6,000 to about 10,000, alternatively from about 6,000 to about 10,000, alternatively from about 7,000 to about 9,000, alternatively combinations thereof. PEG is available from BASF, for example PLURIOL E 8000.
[0012] The compositions of the present invention may comprise from about 65% to about 99% by weight of the composition of PEG. Alternatively, the composition can comprise from about 80% to about 91%, alternatively from about 85% to about 91%, more than about 75%, alternatively from about 70% to about 98%, alternatively from about 80% to about 95%, alternatively combinations thereof, of PEG by weight of the composition.
[0013] Free Perfume
[0014] The compositions of the present invention may comprise a free perfume and/or a perfume microcapsule. Perfumes are generally described in U.S. Pat. No. 7,186,680 at column 10, line 56, to column 25, line 22. In one embodiment, the composition comprises free perfume and is essentially free of perfume carriers, such as a perfume microcapsule. In yet another embodiment, the composition comprises perfume carrier materials (and perfume contained therein). Examples of perfume carrier materials are described in U.S. Pat. No. 7,186,680, column 25, line 23, to column 31, line 7. Specific examples of perfume carrier materials may include cyclodextrin and zeolites.
[0015] In one embodiment, the composition comprises free (neat) perfume but is free or essentially free of a perfume carrier. In such an embodiment, the composition may comprise less than about 20%, alternatively less than about 25%, alternatively from about 9% to about 20%, alternatively from about 10% to about 18%, alternatively from about 11% to about 13%, alternatively combinations thereof, of free perfume by weight of the composition.
[0016] In one embodiment, the composition consists essentially of: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; and (b) from about 9% to about 20% by weight of the composition free perfume; wherein the composition is essentially free of a perfume carrier; and wherein the composition is shaped in a pastille having a mass from about 0.95 mg to about 2 g. In an alternative embodiment, the composition consists essentially of: (a) more than about 75% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; and (b) less than about 25% by weight of the composition free perfume; wherein the composition is essentially free of a perfume carrier; and wherein the composition is shaped in a pastille having a mass from about 0.95 mg to about 2 g.
[0017] In another embodiment, the composition comprises free perfume and perfume microcapsules. In this embodiment, the composition may comprise from about 2% to about 12%, alternatively from about 1% to about 10%, alternatively from about 3% to about 8%, alternatively from about 4% to about 7%, alternatively from about 5% to about 7%, alternatively combinations thereof, of the free perfume by weight of the composition.
[0018] In yet another embodiment, the composition comprises free (neat) perfume and a perfume microcapsule but is free or essentially free of other perfume carriers.
[0019] Perfume Microcapsules
[0020] The compositions of the present invention can comprise perfume oil encapsulated in a perfume microcapsule (PMC). The PMC can be a friable PMC. The term “PMC” and “perfume microcapsule” are used interchangeably and refers to a plurality of perfume microcapsules. Suitable perfume microcapsules and perfume nanocapsules can include: U.S. Patent Publication Nos. 2003215417 A1; 2003216488 A1; 2003158344 A1; 2003165692 A1; 2004071742 A1; 2004071746 A1; 2004072719 A1; 2004072720 A1; 2003203829 A1; 2003195133 A1; 2004087477 A1; and 20040106536 A1; U.S. Pat. Nos. 6,645,479; 6,200,949; 4,882,220; 4,917,920; 4,514,461; and 4,234,627; and U.S. Re. 32,713, and European Patent Publication EP 1393706 A1.
[0021] For purposes of the present invention, the term “perfume microcapsules” or “PMC” describes both perfume microcapsules and perfume nanocapsules. The PMCs can be friable (verses, for example, moisture activated PMCs). The PMCs can be moisture activated.
[0022] In one embodiment, the PMC comprises a melamine/formaldehyde shell. Encapsulated perfume and/or PMC may be obtained from Appleton, Quest International, or International Flavor & Fragrances, or other suitable source. In one embodiment, the PMC shell is coated with polymer to enhance the ability of the PMCs to adhere to fabric, as describe in U.S. Pat. Nos. 7,125,835; 7,196,049; and 7,119,057.
[0023] In one embodiment, the composition comprises a PMC but is free or essentially free or free of (neat) perfume. In such an embodiment, the composition may comprise less than about 20%, alternatively less than about 25%, alternatively from about 9% to about 20%, alternatively from about 9% to about 15%, alternatively from about 10% to about 14%, alternatively from about 11% to about 13%, alternatively combinations thereof, of PMC (including the encapsulated perfume) by weight of the composition. In such an embodiment, the perfume encapsulated by the PMC may comprise from about 0.6% to about 4% of perfume by weight of the composition.
[0024] In one embodiment, the composition consists essentially of: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; and (b) from about 9% to about 20% by weight of the composition of a friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; wherein the composition is essentially free of free perfume; and wherein the composition is shaped in a pastille having a mass from about 0.95 mg to about 2 g. In such an embodiment, the perfume encapsulated by the PMC may comprise from about 0.6% to about 4% of perfume by weight of the composition.
[0025] In another embodiment, the composition comprises PMC and free perfume. In such an embodiment, the composition may comprise from about 1% to about 10%, alternatively from about 2% to about 12%, alternatively from about 2% to about 8%, alternatively from about 3% to about 8%, alternatively from about 4% to about 7%, alternatively from about 5% to about 7%, alternatively combinations thereof, of PMC (including the encapsulated perfume) by weight of the composition. In this embodiment, the perfume encapsulated by the PMC may comprise from about 0.6% to about 4% of perfume by weight of the composition.
[0026] In one embodiment, the composition may consist essentially of: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; (b) from about 2% to about 12% by weight of the composition free perfume; and (c) from about 2% to about 12% by weight of the composition of friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; wherein the composition is shaped in a pastille having a mass from about 0.95 mg to about 2 g. In this embodiment, the perfume encapsulated by the PMC may comprise from about 0.6% to about 4% of perfume by weight of the composition.
[0027] In one embodiment, the composition comprises (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; (b) from about 2% to about 12% by weight of the composition free perfume; and (c) from about 2% to about 12% by weight of the composition of a friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; wherein the composition is shaped in a pastille, each of the pastilles has a mass from about 0.95 mg to about 2 g. Such a formulation is thought to provide for a balanced scent experience to the user of the composition. With the level of polyethylene glycol between about 80% and about 91% by weight of the composition, the about 2% to about 12% by weight of the composition of free perfume can provide for a pleasant scent experience to the user upon opening of the package containing the composition and as the user pours the composition into a dosing device and transfers the composition to her washing machine. That is the user can experience the scent at an appreciably detectable level but is not overwhelmed by the scent. Similarly, the about 2% to about 12% by weight of the composition of friable perfume microcapsule can provide physical and/or chemical stability of the pastille and for a sufficient quantity of friable perfume microcapsule to deposit on a user's clothing during washing when the pastilles are applied in the wash in a unit dose. Further, it can be beneficial for the composition to consist essentially of the above ingredients at the prescribed levels as additional components might interfere with the physical and/or chemical stability of the pastilles and recognizing that other components, such as surfactants, fabric softeners, or other such ingredients, might be delivered by other mechanisms, such as the detergent or dryer added product, and there would be the potential that the user might over apply such ingredients during washing and/or drying.
[0028] In yet another embodiment, the composition can comprise perfume microcapsule but is free or essentially free of other perfume carriers and/or free (neat) perfume. In yet still another embodiment, the composition may comprise a formaldehyde scavenger. In yet still another embodiment, the scent of the present composition is coordinated with scent(s) of other fabric care products (e.g., laundry detergent, fabric softener). This way, consumers who like APRIL FRESH scent, may use a pastille having an APRIL FRESH scent, thereby coordinating the scent experience of washing their laundry with their scent experience from using APRIL FRESH. The pastilles of the present invention may be sold as a product array (with laundry detergent and/or fabric softener) having coordinated scents.
[0029] Dye
[0030] The composition may comprise dye. The dye may include those that are typically used in laundry detergent or fabric softeners. The composition may comprises from about 0.001% to about 0.1%, alternatively from about 0.01% to about 0.02%, alternatively combinations thereof, of dye by weight of the composition. An example of a dye includes LIQUITINT BLUE BL from Millikin Chemical
[0031] Free of Laundry Actives and Softeners
[0032] The composition may be free of laundry active and/or fabric softener actives. To reduce costs and avoid formulation capability issues, one aspect of the invention may include compositions that are free or essentially free of laundry actives and/or fabric softener actives. In one embodiment, the composition comprises less than about 3%, alternatively less than about 2% by weight of the composition, alternatively less than about 1% by weight of the composition, alternatively less than about 0.1% by weight of the composition, alternatively are about free, of laundry actives and/or fabric softener actives (or combinations thereof). A laundry active includes: detergent surfactants, detergent builders, bleaching agents, enzymes, mixtures thereof, and the like. It is appreciated that a non-detersive level of surfactant may be used to help solubilize perfume contained in the composition.
[0033] Pastilles
[0034] The composition of the present invention may be formed into pastilles by those methods known in the art, including methods disclosed in U.S. Pat. Nos. 5,013,498 and 5,770,235. The composition of the present invention may be prepared in either batch or continuous mode. In batch mode, molten PEG is loaded into a mixing vessel having temperature control. PMC is then added and mixed with PEG until homogeneous. Perfume is then added to the vessel and the components are further mixed for a period of time until the entire mixture is homogeneous. In continuous mode, molten PEG is mixed with perfume and PMC in an in-line mixer such as a static mixer or a high shear mixer and the resulting homogeneous mixture is then used for pastillation. PMC and perfume can be added to PEG in any order or simultaneously and dye can be added at a step prior to pastillation.
[0035] The pastilles may be formed into different shapes include tablets, pills, spheres, and the like. A pastille can have a shape selected from the group consisting of spherical, hemispherical, compressed hemispherical, lentil shaped, and oblong. Lentil shaped refers to the shape of a lentil bean. Compressed hemispherical refers to a shape corresponding to a hemisphere that is at least partially flattened such that the curvature of the curved surface is less, on average, than the curvature of a hemisphere having the same radius. A compressed hemispherical pastille can have a ratio of height to diameter of from about 0.01 to about 0.4, alternatively from about 0.1 to about 0.4, alternatively from about 0.2 to about 0.3. Oblong shaped refers to a shape having a maximum dimension and a maximum secondary dimension orthogonal to the maximum dimension, wherein the ratio of maximum dimension to the maximum secondary dimension is greater than about 1.2. An oblong shape can have a ratio of maximum dimension to maximum secondary dimension greater than about 1.5. An oblong shape can have a ratio of maximum dimension to maximum secondary dimension greater than about 2. Oblong shaped particles can have a maximum dimension from about 2 mm to about 6 mm, a maximum secondary dimension of from about 2 mm to about 4 mm
[0036] In alternative embodiments of any of the formulations disclosed herein, each individual pastille can have a mass from about 0.95 mg to about 2 g, alternatively from about 10 mg to about 1 g, alternatively from about 10 mg to about 500 mg, alternatively from about 10 mg to about 250 mg, alternatively from about 0.95 mg to about 125 mg, alternatively combinations thereof. In a plurality of pastilles, individual pastilles can have a shape selected from the group consisting of spherical, hemispherical, compressed hemispherical, lentil shaped, and oblong.
[0037] An individual pastille may have a volume from about 0.003 cm 3 to about 0.15 cm 3 . A plurality of pastilles may collectively comprise a unit dose for dosing to a laundry washing machine or laundry was basin. A single unit dose of the pastilles may comprise from about 13 g to about 27 g, alternatively from about 14 g to about 20 g, alternatively from about 15 g to about 19 g, alternatively from about 16 g to about 18 g, alternatively combinations thereof. The individual pastilles forming the plurality of pastilles that make up the unit dose can each have a mass from about 0.95 mg to about 2 g. The plurality of pastilles can be made up of pastilles of different size, shape, and/or mass. The pastilles in a unit dose can have a maximum dimension less than about 1 centimeter.
[0038] The composition may be manufactured by a pastillation process. A schematic of a pastillation apparatus 100 is illustrated in FIG. 1 . The steps of manufacturing according to such process can comprise providing the desired formulation as a viscous material 50 . The viscous material 50 can comprise or consists of any of the possible formulations disclosed herein. In one embodiment, the viscous material 50 comprises: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; (b) from about 2% to about 12% by weight of the composition free perfume; and (c) from about 2% to about 12% by weight of the composition of friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume. The viscous material 50 can be provided at a processing temperature less than about 20 degrees Celsius above the onset of solidification temperature as determined by differential scanning calorimetry.
[0039] In one embodiment, the PMC can be added as a slurry to the polyethylene glycol and free perfume to form the viscous material 50 . The PMC can be added as a powder to the polyethylene glycol and free perfume to form the viscous material 50 . The viscous material 50 is passed through small openings 10 and onto a moving conveyor surface 20 upon which the viscous material 50 is cooled below the glass transition temperature to form a plurality of pastilles 30 . As illustrated in FIG. 1 , the small openings 10 can be on a rotatable pastillation roll 5 . Viscous material 50 can be distributed to the small openings 10 by a viscous material distributor 40 . Pastilles can be formed on a ROTOFORMER, available from Sandvik Materials Technology.
[0040] Package
[0041] A unit dose or a plurality of unit doses may be contained in a package. The package may be a bottle, bag, or other container. In one embodiment, the package is a bottle, preferably a PET bottle comprising a translucent portion to showcase the pastilles to a viewing consumer. In one embodiment, the package comprises a single unit dose (e.g., trial size sachet); or multiple unit doses (e.g., from about 15 unit doses to about 30 unit doses).
[0042] Dosing
[0043] The aforementioned package may comprise a dosing means for dispensing the pastilles from the package to a laundry washing machine (or laundry wash basin in hand washing applications). The user may use the dosing means to meter the recommended unit dose amount or simply use the dosing means to meter the pastilles according to the user's own scent preference. Examples of a dosing means may be a dispensing cap, dome, or the like, that is functionally attached to the package. The dosing means can be releasably detachable from the package and re-attachable to the package, such as for example, a cup mountable on the package. The dosing means may be tethered (e.g., by hinge or string) to the rest of the package (or alternatively un-tethered). The dosing means may have one or more demarcations (e.g., fill-line) to indicate a recommend unit dose amount. The packaging may include instructions instructing the user to open the removable opening of the package, and dispense (e.g., pour) the pastilles contained in the package into the dosing means. Thereafter, the user may be instructed to dose the pastilles contained in the dosing means to a laundry washing machine or laundry wash basin. The pastille of the present invention may be used to add freshness to laundry. The package including the dosing means may be made of plastic.
[0044] One embodiment can be a unit dose of a fabric treatment composition comprising a plurality of pastilles, wherein each pastille comprises: (a) from about 80% to about 91% by weight of the composition of polyethylene glycol, wherein the polyethylene glycol has a molecular weight from about 5,000 to about 11,000; (b) from about 2% to about 12% by weight of the composition free perfume; and (c) from about 2% to about 12% by weight of the composition of friable perfume microcapsule, wherein the perfume microcapsule comprises encapsulated perfume; wherein each pastille has a mass from about 0.95 mg to about 2 g; and wherein the plurality of pastilles has a mass from about 13 g to about 27 g to comprise the unit dose.
[0045] In one embodiment, the pastilles of the present invention can be administered to a laundry machine as used during the “wash cycle” of the washing machine (but a “rinse cycle” may also be used). In another embodiment, the pastilles of the present invention are administered in a laundry wash basin—during washing and/or rinsing laundry. In a laundry hand rinsing application, the pastille may further comprise an “antifoam agent” such as those available from Wacker. Antifoam agents (suds suppressing systems) are described in U.S. Patent Publication No. 20030060389 at 65-77.
EXAMPLE
[0046]
[0000]
Grams in a
% Weight
Ingredient:
17 g unit Dose
of Composition
PEG 8000
15
88.24%
Free (neat) Perfume
1
5.88%
Perfume Microcapsule 1
1
5.88%
(Encapsulated perfume) 2
(0.32)
(1.88%)
Dye
0.0025
0.015%
1 PMC is a friable PMC with a urea-formaldehyde shell from Appleton. About 50% water by weight of the PMC (including encapsulated perfume) is assumed.
2 Encapsulated perfume (within PMC) assumes about 32% active.
[0047] The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm ”
[0048] Every document cited herein, including any cross referenced or related patent or application, is hereby incorporated herein by reference in its entirety unless expressly excluded or otherwise limited. The citation of any document is not an admission that it is prior art with respect to any invention disclosed or claimed herein or that it alone, or in any combination with any other reference or references, teaches, suggests or discloses any such invention. Further, to the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
[0049] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this invention. | A laundry scent additive having polyethylene glycol and perfume. The laundry scent additive enables consumers to control the amount of scent imparted to their laundry. | 3 |
It is known that in many cases it is required to store power, and this power be slowly and gradually released, upon actuating a control therefor.
Substantially and particularly in the field of the tape recorders, the above mentioned servomechanism utilizes a motor loading an elastic body, such as a spring for example, which upon being controlled releases the stored power to be used for example for the ejection of a cassette out from a tape recorder.
The problem of this servomechnism is to provide coupling with the motor only during the spring preloading period; at the end of said preloading, the coupling with the motor or with the member driven by the motor, is to be removed, and the motor has to work for driving the main member (e.g. the tape of the recorder) with no other impediments; then, with or without power supply, the servomechanism has to release the power stored therein, but slowly, and thus the power releasing is to be slowed down. At the end of said power releasing, there is to be established a reengagement condition for the next sequence.
SUMMARY OF THE INVENTION
Such configuration of the servomechanism, in itself already known, particularly as regards dimensions, efficiency, gear ratios, reliability, is in fact a rather complicated problem. The object of this invention is to provide a mechanism operating for the coupling with the power take-off, in particular with a toothed pinion; the loading of a spring; the automatic disengagement, at the end of the spring loading, from said toothed pinion; the locking of the releasing means so that, in a rest condition, the spring remains loaded, and then, when desired, upon applying a control or automatically, a slow release of the stored power is obtained.
The device according to this invention substantially consists of storage means, such as a spring, coupled with a driving member, such as a rack; a wheelwork, alternately driven by a motor and by the storing member; a lever fulcrumed to one of the wheelwork gears, and oscillating between two fixed positions, by means of a chronometer escapement means.
BRIEF DESCRIPTION OF THE DRAWINGS
The device of this invention will be better understood through a reading of the following description with reference to the accompanying drawing, wherein an embodiment of the device of this invention in three positions is schematically illustrated, by way of example.
In the drawings:
FIG. 1 shows the device of this invention in a rest position, with the storage member being in a rest position;
FIG. 2 shows the device while loading the storage member;
FIG. 3 shows the device in a rest position, with the storage member loaded.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawing, the device appears substantially consisting of a power take-off toothed pinion 10; a rack 11 which, during its displacement drives a spring 16; a wheelwork 12, 13 and 14; a small anchor 15, a flip-flop 20; and a lever 17.
The rack 11 has two detents 22 and 23, and the flip-flop 20 has a pin 21 and two detents 18, 19. The detents 18, 19, the fulcrum 21 of the flip-flop, the detents 22, 23 of the rack, the pin of the pinion 10, and the fulcrum of lever 17, as well as the small anchor 15 and the coupling of spring 16 are all related to the frame on which the device is mounted. The lever 17 is fulcrumed about the axis of the toothed wheel 12, and carries fulcrumed thereon the toothed wheel 13 and the star-like radial wheel 14. The reason for this arrangement will be seen later.
Starting from the position illustrated in FIG. 1, that is to say with the device in a rest condition, the power take-off 10 works freely and has no connection with the loading system, the spring 20 holds the lever 17 against the detent 19, thereby assuring the whole system release. Assuming that by means of a control, schematically indicated by an arrow 24, which simulates the coupling thrust, one acts upon the lower arm of the lever 17, one operates by shifting from the position shown in FIG. 1 to the position shown in FIG. 2. It is to be noted that, in this position, the bistable 20, thus operating, urges the lever 17 towards the detent 18. The pinion 10 then comes into contact, or better, into a gearing engagement with the toothed wheel 13, inasmuch as both wheels 13 and 14 are carried by the lever 17. The movement of the lever 17 then causes the wheels 13, 14 to rotate angularly, producing the coupling of the toothed wheel 13 with the pinion 10. As a result, wheels 12, 13 and 14 move in the directions shown in FIG. 2 by the respective arrows. It is to be outlined that wheel 14, in this condition is idly rotating, whereas wheel 13, which receives its movement from the pinion 10, drives the toothed wheel 12, which, in turn, drives the rack 11, thereby loading the spring 16.
When the rack reaches the end of its stroke, such as the stop 23, or particularly an obstacle, an overload or other, so as to cause an unbalance, the wheel 12 can no longer turn and then the torque that the pinion 10 transfers to the wheel 13 constrains the latter to roll along the periphery of the wheel 12. As a result of this rolling, the lever 17 moves angularly and displaces therewith also the toothed wheel 14. When the whole assembly has reached a given position, whereby the teeth of the toothed wheel 13 clear off the teeth of the toothed pinion 10, the lever 17 has thus passed the center line of the flip-flop 20, whereby lever 17 itself, due to the actuation of the flip-flop 20 moves independently from the motion drive by the pinion 10 so as to reach the second position of the bistable 20 defined when the lever 17 abuts against the detent 19.
Now we are in the position particularly illustrated in FIG. 3.
As it can be seen, in the loading position, the several parts forming the device are almost in the position illustrated in FIG. 1, except that spring 16 is now completely loaded and the rack 11 abuts against the stop 23. Then, in the position shown in FIG. 3, there are established some torques indicated by the respective arrows. This means that now the disposition of the device is the same as the geometrical disposition of the position shown in FIG. 1, but this is a completely different kinematic position. At this point it is to be noted that the star-like wheel 14 is engaged with the anchor 15, and if the anchor is locked either by the mechanical system or by an electromechanical means, the spring 16 is still tensioned and the system cannot be released. Moreover, since from the rack 11 to the star-like wheel 14 there is a wheelwork 12, 13, 14, the locking torque of the system is greatly reduced, whereby the anchor 15 can be locked with a minimum force, and this is very advantageous for the relay that should pilot it, if necessary. The situation illustrated in FIG. 3 remains stable until the time when, due to the actuation of a manual control or by means of an interlocked system, the holding relay, not shown in the drawings, releases the anchor. In the moment when the locking action on the anchor is removed, the latter starts oscillating as a common chronometer escapement system. The power stored by the spring 16 is thus returned back through this escapement system, and therefore slowly and almost constantly until the whole system is released and the rack 11 and spring 16 return back to the position shown in FIG. 1. At this point the device is ready to start a new duty cycle.
As it can be seen from the drawing and the foregoing description, the device is particularly simple, inexpensive, practical and reliable, a transmission being realized thereby in order to bring the torque of the pinion 10 in relation with the bias on the spring 16, namely that one which could be otherwise called a step-up transmission. This step-up transmission, for reasons of locking and release, is again multiplied in order to reduce the necessary effort to hold the anchor 15. This is a particularly important solution to a highly considerable problem, and namely the problem of satisfactorily having a system which could be locked with a minimum of power, and this particularly for tape recorders, inasmuch as the relay must always be kept on during the operation of the tape recorder so that it becomes operative in case of failure of the electric power, it is evident that the load of this relay must be extremely reduced in order to reduce the passive electric energy consumtion.
As it can be seen from the drawing, the lever 17 is indicated in an extremely schematic form, but it is the lever 17 that performs the control for the several components coupled with it.
The device has been essentially shown and described with reference to a preferred embodiment thereof, but it appears evident that some structural type modifications could be made in it as may be dictated by the art and the common practice, without, however, departing from the scope of the invention which is defined by the following claims. | A device for storing power and providing for the controllable slow rate release of the stored power is provided. The device comprises a wheelwork fulcrumed to and carried by a pivotal lever, wherein the wheelwork is alternately operated by a motor driven pinion and by an energy storage member. | 6 |
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Application 61/577,241 filed Dec. 19, 2011, and the complete contents of that application is herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention pertains to electrospinning for the production of nanofibers and nanofiber webs, and, more particularly, the invention is focused on producing nanofibers and nanofiber webs from a polymer melt.
BACKGROUND
[0003] Electrospinning is a process that is used to produce nanofibers and nanofiber webs. The nanofibers and nanofiber webs have been evaluated for use in a wide range of applications including without limitation in filtration, protective clothing, drug delivery, tissue engineering, and nanocomposites. Although there is significant research interest in nanofiber development, most of the current work is focused on electrospinning from solutions. Solution electrospinning can pose a significant safety problem during manufacture since most solvents used for synthetic polymers are highly flammable, as well as toxic or carcinogenic. The solvents employed in solution based electrospinning also pose additional concerns such as solvent cost, solvent recovery, low production rates, and limiting limited biomedical applications due to residual toxic solvent. Hence, there is a strong interest in developing solvent-free processes such as melt processes for the manufacture of nanofibers.
SUMMARY
[0004] In an embodiment of the invention, co-extrusion technology is combined with electroprocessing technology to produce nanofibers containing multiple layers of materials.
[0005] In another embodiment of the invention, multilayered nanofibers produced by electroprocessing are effectively “delaminated” (i.e., the layers within the fibers are separated) by sonication or other suitable energy application techniques.
[0006] According to an embodiment of the invention, a “solvent-free” process is used to create fibrous materials that have significantly higher surface areas than currently manufactured nanofibers. Specifically, the process combines co-extrusion where two polymer resins in the molten state are arranged to give alternating layers via feed blocks or layer multipliers, with melt electrospinning (or other suitable electroprocessing). By combining the two technologies, nonwoven webs that have hundreds to over a thousand layers within each microfiber can be created. These webs can be subsequently exposed to ultrasonication to create delamination of the layers which result in nanolayer melt electrospun (NME) fibrous webs.
[0007] The multilayer electrospun fibers have been evaluated using electron microscopy both before and after sonication. Experiments have demonstrated that melt electrospun fibers produced according to the invention with 257 alternating layers can be successfully produced and delaminated by ultrasonication.
[0008] The invention includes melt electrospun fibers and matrices, such as non-woven webs, of fibers that contain alternating layers, and their method of production. In addition, the invention includes nanolayer thick fibers (e.g., fiber ribbons) created by delamination of melt electrospun fibers having alternating layers of polymers. Also, the invention includes matrices of these nanolayer thick fibers, in laminated or delaminated form. In some applications, the inventive matrices can have substances of interest deposited on them (e.g., bioactive agents, catalytic agents, fire retardant chemicals, etc.).
[0009] In any exemplary embodiment, two extruders deliver different polymers to a 3 layer feedblock where layering of the melt occurs and this 3 layer melt stream is fed to a single orifice die. A high voltage is applied to a flat plate collector placed at a suitable distance from the die and electrospun fibers are formed and collected on the flat plate. In another exemplary embodiment of this invention, the 3 layer melt stream is fed to a layer multiplying unit where the melt layers are multiplied (multiplying depends on the number of multipliers used). A melt stream with 257 layers, when 7 multipliers are used, is fed to the single orifice die. A high voltage is applied to a flat plate collector placed at a suitable distance and electrospun fibers are collected on the flat plate. In yet another embodiment of the invention, melt electrospun webs that have about 257 alternating layer fibers are exposed to ultrasonication (or other energy application or chemical application) to create nanolayer thick fibers due to delamination of the layers. Delamination can be achieved by other mechanisms such as exposure to chemicals such as chloroform,
DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1( a ) is a schematic of the layer multiplying process that occurs when using two layers as input to the layer multiplying process.
[0011] FIG. 1( b ) is a schematic of the cross-section of a fiber with multiple layers of two different polymers.
[0012] FIGS. 2A-C are, respectively, schematic drawings of a system for producing multilayer electrospun fibers according to the invention with a flat plate collector ( FIG. 2A ), a rotary drum collector ( FIG. 2B ), and a wide width die in combination with a rotary drum collector ( FIG. 2C ).
[0013] FIG. 3 illustrates a simplified process for delaminating fibers in a fibrous mat formed by melt electroprocessing multiple polymers according to the invention.
[0014] FIG. 4 is a scanning electron micrograph (SEM) of a melt electrospun fiber described in Example 1 that has 257 alternating layers of polycaopactone (PCL) and polyethylene (PE).
[0015] FIG. 5 is a SEM image of a melt electrospun fiber described in Example 2 that has 257 alternating layers of PCL and PE.
[0016] FIG. 6 is a SEM image of a melt electrospun fiber web described in Example 7 that has 257 alternating layers of PCL and PE after ultarsonication which shows delamination of the layers after sonication.
[0017] FIG. 7 is an SEM image of a melt electrospun fiber web described in Example 8 where PCL and PP layers in the fibers are delaminated by exposure to chloroform with slight agitation.
[0018] FIG. 8 is an SEM image of a melt electrospun fiber web described in Example 9 where PCL and PE layers in the fibers are delaminated by exposure to chloroform with slight agitation.
DETAILED DESCRIPTION
[0019] “Co-extrusion” in the context of the present invention is a process by which two polymer resins in the molten state are arranged via feed blocks or layer multipliers to give alternating layers. The number of layers in the final extruded form (e.g., film or microfiber) can be as low as two or in the hundreds (up to and exceeding a thousand). While feedblock technology is typically used to produce films with approximately 3 to 7 layers, layer-multiplying technology is used to produce hundreds to thousands of layers within 25-50 micron thick films. The layer multiplying process is shown schematically in FIGS. 1 a and 1 b.
[0020] With reference to FIG. 1 a there is shown a two component (AB) co-extrusion system which could include, for example, two single screw extruders each connected by a melt pump to a co-extrusion feedblock. The feedblock combines polymeric material (a) and polymeric material (b) in an (AB) layer configuration (see leftmost portion of FIG. 1 a ). Melt pumps (not shown) control the two melt streams that are combined in the feedblock as two parallel layers. By adjusting the melt pump speed, the relative layer thickness, that is, the ratio of A to B can be varied (as shown, the ratio of the top layer to the bottom layer). From the feedblock, the melt goes through a series of multiplying elements. As shown in FIG. 1 a a multiplying element first slices the AB structure vertically, and subsequently spreads the melt horizontally. The flowing streams recombine, doubling the number of layers. An assembly of n multiplier elements produces an extrudate with the layer sequence (AB) x where x is equal to (2) n and n is the number of multiplying elements to form a multilayer stack (as depicted in the right most portion of FIG. 1 a ). FIG. 1 b is a cross-sectional view of a fiber with multiple layers produced by co-extrusion (it being recognized that the layers in a co-extruded fiber may not be flat as depicted in FIG. 1 b; rather, the individual layers may be curved or have other configurations, but will form distinct regions in the fiber).
[0021] Co-extrusion with the use of feedblocks and multipliers is a well understood technique in chemical engineering (see, for example, U.S. Pat. No. 7,936,802, U.S. Pat. No. 7,141,297, U.S. Pat. No. 7,255,928, U.S. Pat. No. 7,052,762, U.S. Pat. No. 3,565,985, and U.S. Pat. No. 3,051,453, each of which are herein incorporated by reference). Layered melt blown fibers made using feed block technology are described in U.S. Pat. No. 5,176,952 and U.S. Pat. No. 5,207,970, both of which are herein incorporated by reference.
[0022] The Examples below show the combination of polyethylene (PE) and polycaprolactone (PCL) being combined as multiple layers in electroprocessed fibers according to the present invention. However, many different polymers can be employed in the practice of the invention including without limitation polyolefins (e.g., polyethylene, polypropylene, etc.), poly(urethanes), poly(siloxanes), poly(vinyl pyrolidone), poly(2-hydroxy ethyl methacrylate), poly(N-vinyl pyrrolidone), poly(methyl methacrylate), poly(vinyl alcohol), poly(acrylic acid), polyacrylamide, poly(ethylene-co-vinyl acetate), poly(ethylene glycol), poly(methacrylic acid), polylactides (PLA), polyplycolides (PGA), poly(lactide-co-glycolides) (PLGA), polyanhydrides, polyorthoesters, styrene-diene block copolymers, and block copolymers with tackifiers. In addition, thermally stable and melt processable natural polymers (e.g., those occurring naturally in a plant or animal) can be employed in the practice of the invention including without limitation plasticized cellulose acetate.
[0023] In the context of the present invention, “electroprocessing” or “electrodeposition” broadly include all methods of electrospinning, electrospraying, electroaerosoling, and electrosputtering of materials, including combinations of two or more of such methods, as well as any other method wherein materials are streamed, sprayed, sputtered, or dripped across an electric field toward a target. A material can be electroprocessed from one or more grounded reservoirs in the direction of a charged substrate or from charged reservoirs toward a grounded target. Electroprocessing can be performed using one or a plurality of nozzles, and, in the case of using multiple nozzles, each nozzle can be connected to a single reservoir or each can be connected to a different reservoir where each reservoir contains the same or a different melt. The size of the nozzles can be varied to provide for increased or decreased flow out of the nozzles, and a pump or a plurality of pumps can be used to control flow from the reservoir(s). Electrospinning is generally defined as a process by which fibers are formed from melt by streaming the melt through an orifice. In an embodiment of this invention, elecrospinning is achieved by applying a voltage to a collector and the melt is streamed from through the orifice to the collector. Other configurations are possible. Electroaerosoling is generally defined as a process by which droplets are formed from a melt by streaming an electrically charged solution or melt through an orifice.
[0024] Electroprocessing techniques are well known in the art. See, for example, U.S. Pat. No. 7,759,082, U.S. Pat. No. 7,615,373, U.S. Pat. No. 7,374,774, U.S. Pat. No. 6,787,357, U.S. Pat. No. 8,282,712, U.S. Pat. No. 6,592,623, U.S. Pat. No. 8,282,712, U.S. Pat. No. 8,277,712, U.S. Pat. No. 8,277,711, U.S. Pat. No. 8,277,706, U.S. Pat. No. 8,262,958, U.S. Pat. No. 8,257,628, U.S. Pat. No. 8,247,335, U.S. Pat. No. 8,246,730, U.S. Pat. No. 8,241,729, U.S. Pat. No. 8,178,199, U.S. Pat. No. 8,240,174, U.S. Pat. No. 8,206,484, U.S. Pat. No. 8,178,199, U.S. Pat. No. 8,178,029, U.S. Pat. No. 8,173,559, U.S. Pat. No. 8,172,092, U.S. Pat. No. 8,168,550, U.S. Pat. No. 8,163,350, U.S. Pat. No. 8,052,407, U.S. Pat. No. 7,757,811, U.S. Pat. No. 7,754,123, U.S. Pat. No. 7,717,975, U.S. Pat. No. 7,691,168, U.S. Pat. No. 7,662,332, U.S. Pat. No. 7,628,941, U.S. Pat. No. 7,618,579, U.S. Pat. No. 7,601,262, U.S. Pat. No. 7,452,835, U.S. Pat. No. 7,291,300, U.S. Pat. No. 7,134,857, U.S. Pat. No. 7,070,640, and U.S. Pat. No. 6,838,005, each of which are herein incorporated by reference. As discussed in these patents, natural fibers (e.g., collagen, fibrin, etc.), and synthetic fibers, and combinations thereof can be produced from solutions by electroprocessing.
[0025] The invention contemplates a co-extruded stream of two or more polymer melts (e.g., polymer blend streams), which can be multiplied or not multiplied, being subject to electroprocessing to produce fibers with a plurality of layers therein. The fibers will have at least two layers (Examples below show co-extruded, electroprocessed fibers with three layers, and show the order of the layers does not impact the ability to form fibers), and possibly 50 to 100 or more layers (Examples below show co-extruded, electroprocessed fibers with 247 layers).
[0026] The fibers produced by co-extrusion and electroprocessing according to the invention are multilayered and have a diameter of 100 μm or less. As shown in the Examples below, fibers of 50 μm or less have been produced, and some multilayer fibers having diameters as small as 5-10 μm have been produced. Furthermore, on delamination of the multilayer fibers, ribbon shaped fibers which have thicknesses on the order of nanometers have been produced.
[0027] In a preferred embodiment, the electroprocessed materials form a “matrix”. Matrices are comprised of multilayer fibers, or blends of multilayer fibers and droplets of any size or shape. Matrices can be single structures or groups of structures, and can be formed through one or more electroprocessing methods using a plurality of materials. Matrices can be engineered to possess specific porosities.
[0028] Substances of interest can be deposited within, anchored to, or placed on matrices. Exemplary substances of interest can include bioactive agents (e.g., proteins, nucleic acids, antibodies, anesthetics, hypnotics, sedatives, sleep inducers, antipsychotics, antidepressants, antiallergics, antianginals, antiarthritics, antiasthmatics, antidiabetics, antidiarrheal drugs, anticonvulsants, antigout drugs, antihistamines, antipruritics, emetics, antiemetics, antispasmondics, appetite suppressants, neuroactive substances, neurotransmitter agonists, antagonists, receptor blockers, reuptake modulators, beta-adrenergic blockers, calcium channel blockers, disulfarim, muscle relaxants, analgesics, antipyretics, stimulants, anticholinesterase agents, parasympathomimetic agents, hormones, anticoagulants, antithrombotics, thrombolytics, immunoglobulins, immunosuppressants, hormone agonists, hormone antagonists, vitamins, antimicrobial agents, antineoplastics, antacids, digestants, laxatives, cathartics, antiseptics, diuretics, disinfectants, fungicides, ectoparasiticides, antiparasitics, heavy metals, heavy metal antagonists, chelating agents, alkaloids, salts, ions, autacoids, digitalis, cardiac glycosides, antiarrhythmics, antihypertensives, vasodilators, vasoconstrictors, antimuscarinics, ganglionic stimulating agents, ganglionic blocking agents, neuromuscular blocking agents, adrenergic nerve inhibitors, anti-oxidants, anti-inflammatories, wound care products, antithrombogenic agents, antitumoral agents, antithrombogenic agents, antiangiogenic agents, antigenic agents, wound healing agents, plant extracts, growth factors, growth hormones, cytokines, immunoglobulins, osteoblasts, myoblasts, neuroblasts, fibroblasts, glioblasts; germ cells, hepatocytes, chondrocytes, keratinocytes, smooth muscle cells, cardiac muscle cells, connective tissue cells, epithelial cells, endothelial cells, hormone-secreting, cells, neurons, emollients, humectants, anti-rejection drugs, spermicides, conditioners, antibacterial agents, antifungal agents, antiviral agents, antibiotics, tranquilizers, cholesterol-reducing drugs, antitussives, histamine-blocking drugs and monoamine oxidase inhibitors), catalysts (e.g., metals and metal alloys, such as platinum, gold, ruthenium, rhodium, iridium, transition metals and transition metal complexes, nanomaterial catalysts, zeolites, alumina etc.), flame retarding agents, and carbon black
[0029] FIGS. 2A-C shows schematic drawings of an exemplary electroprocessing configuration where a voltage controller 10 is used to charge a target 12 or 12 ′. In FIG. 2A , the target 12 is a flat panel. In FIGS. 2B and 2C , the target 12 ′ is a mandrel or rotary drum. In FIGS. 2B and 2C , the target 12 may be rotated during electroprocessing in order to take up thicker non-woven mats of multilayer fibers. The Target 12 or 12 ′ can be of many different shapes and sizes to suit the needs of the application.
[0030] Each of FIGS. 2A-2C , show a source 13 having a feedblock 14 and multiplier section 15 that allow combining a plurality of polymers from polymer sources 16 a - 16 n. The multiplier section 15 can have zero to a plurality of multipliers (e.g., 2, 3, 7, 10, 20, etc.) depending on the application. With zero multipliers, the feedblock 14 will be used to introduce a layered polymer melt for electroprocessing. However, in some applications, it will be advantageous to have 50 or 100 or more layers in each fiber (the Examples below show formation of fibers with 247 layers). In the present invention, the fibers produced will have at least two different layers of two different polymers (the Examples below show some fibers produced with three different layers having two different polymers, wherein in one Example the outer layers are PE and the inner layer is PCL and in another Example the inner layer is PE and the outer layer is PCL). While the Examples below show combining two polymers into one multilayered fiber, it will be recognized that a plurality of the polymers can be combined by co-extrusion. Thus, fibers having layers of three different polymers, four different polymers, five different polymers, etc. can be made according to the present invention. Thus, FIGS. 2A-C are depicted with polymer sources 16 A- 16 N, where N equals the number of polymers being combined. Further, the polymers in the polymer sources 16 A- 16 N may themselves be polymer blends.
[0031] For simplicity, FIGS. 2A-2C show a single source 13 . However, it should be recognized that in the practice of the present invention there can be a plurality of sources interacting with a single target 12 or 12 ′ during electroprocessing, and that the polymers provided by each of the sources can be the same or different. Furthermore, different operational designs can be used for each of the sources to achieve the formation of multilayer fibers of different diameter as well as mixtures of multilayer fibers and multilayer droplets. In the context of the invention, what is required is that the polymers provided by source 13 have at least two different layers of two different polymers. The thickness of each of the layers of polymers in the fiber can be varied by a variety of means including by control of pumps (not shown) from the polymer sources 16 A- 16 N.
[0032] In FIGS. 2A-2C , the stream of polymer 18 emanating from the nozzles or “tips” 20 or 20 ′ directed towards the target 12 or 12 ′ can be controlled. For example, source 13 could supply a stream 18 of multilayer fibers or a mixture of multilayer fibers and droplets towards target 12 , or source 13 could supply a stream 22 of multilayer fiber which may include branching. Control of the streams can be achieved by a variety of mechanisms including controlling polymer supply pumps, regulating the nozzle 20 or 20 ′ sizes in the sources 13 , regulating the charge on the polymer and/or target 12 or 12 ′, etc. Ultimately, the target 12 or 12 ′ will receive a mass of multilayer fibers generally configured as a non-woven mat. The multilayer fibers can have some crosslinking with the polymers in adjacent fibers, and can contain multilayer droplets interspersed with the multilayer fibers. The bottom of FIG. 2C shows a plan view of the tip 20 ′ where there are multiple orifices for emitting multiple streams of polymer during electroprocessing. With this design a thick mat can be created over a wide area in a short term.
[0033] FIG. 3 illustrates the process of converting the multilayer fibers created by coextrusion/electroprocessing to ribbon shaped fibers, as shown by Example 7 below. The fibrous mat 50 from the electrospinning target is placed in a delaminating device 52 such as a sonicating bath. The sonicating bath 50 can contain any suitable fluid (e.g., water, solvents, etc.) for permitting ultrasonic energy to interact with the fibers such as, for example, a mixture of isopropanol and water. Alternatively, delamination may be achieved chemically by, for example, exposure to chloroform, ethyl acetate, or other solvent. Further, chemical and physical techniques may be used in combination, for example, by exposure to chloroform or ethyl acetate which promotes delamination (e.g., by a rinse) in combination with exposure to energy (e.g., sonication). Delamination can be achieved fairly quickly. For example, sonication of a multilayered polyethylene/polycaprolactone fiber of less than 100 μm in diameter achieved delamination in approximately 30 seconds. FIG. 3 shows the delaminated fibers 54 can be retrieved as a mat from the delaminator (sonicating bath) 52 . The delaminated fibers 54 are comprised of a plurality of ribbon shaped fibers, typically on the order of nanometers in thickness where each individual ribbon is of one distinct material. FIG. 3 also shows that active agents 56 (such as biological active agents, catalytic agents, etc.) can be deposited on the delaminated fibers 54 . This can be accomplished by spraying the active agent onto the mat, dipping the mat into a pool of active agents, electroplating the active agent onto the mat, and by many other means recognized by those of skill in the art. In addition, while FIG. 3 shows application of the active agent 56 to the delaminated fibers 54 , in some applications, active agents could simply be applied to the mat of multilayer fibers 50 .
[0034] The fibrous mats produced according to the invention can be used in a wide variety of applications including without limitation filtration, protective clothing, drug delivery, tissue engineering, and nanocomposites. The fibrous materials have significantly higher surface areas than currently manufactured nanofibers, which can provide superior properties in many applications. In addition, the fibrous materials are manufactured in a “solvent free” manner which avoids many of the manufacturing risks and costs encountered in current electrospinning processes.
EXAMPLES
[0035] In the Examples below, the polymeric components are melted in a single screw extruder and transported via gear pumps to a 3 layer feedblock, where the two polymers are formed into a single flow stream of 3 alternating layers. This 3 layer melt stream is delivered to a layer multiplier that has seven multipliers where the 3 layer stream is cut and stacked seven times to have final melt stream that has 257 alternating layers. This melt stream is delivered to a single orifice die and electrospun into fibers by the application of a high voltage to a flat plate collector which is positioned at a suitable distance across from the die.
[0036] The size and structure of the electrospun fibers were obtained using a LEO (Zeiss) 1550 field emission scanning electron microscope (FE-SEM) in the secondary electron mode. Scanning electron microscopy images were obtained at different magnifications and the fiber diameters were measured using image analysis software.
[0037] For delamination, the melt electrospun fibers and webs were immersed in a water/isopropanol (w/w 80/20) mix and exposed to sonication using a Tekmar Sonic Disruptor at different intensities and time periods. These materials were viewed in the SEM to determine if delamination of the layers occurred and to what extent it occurred.
Example 1
[0038] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polyethylene (PE) resin (Epolene C-10 available from Westlake Chemical Corporation). The polymer pellets were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 356° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL PE ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 1 revolution per minute (RPM). The layered melt stream was fed to a layer multiplier that had 7 multipliers, which cut and stacked the layered stream 7× and resulted in a melt stream that had 257 layers upon exiting the layer multiplier. The layer multiplier was maintained at about 356° F. This stream with 257 alternating layers was fed to a single orifice die which was maintained at about 356° F., and a voltage of 58 kV was applied to a flat plate collector placed 6 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 258 alternating PCL/PE layers.
[0039] A scanning electron micrograph (SEM) of the electrospun fiber produced according to this Example 1 is presented in FIG. 4 . The diameter of the fiber is approximately 5-10 μm.
Example 2
[0040] A melt electrospun fiber and web, comprising 257 layer fibers was prepared according to the procedure described in Example 1, except the voltage applied was 42 kV.
[0041] An SEM of the electrospun fibers is presented in FIG. 5 . The fiber diameters are approximately in the 25 to 30 μm range.
Example 3
[0042] A melt electrospun fiber and web, comprising 257 layer fibers was prepared according to the procedure described in Example 1, except the flow rate of both gear pumps were maintained at 2 RPM's, the voltage was 60 kV and the flat plate collector was placed 4 inches away from the die.
Example 4
[0043] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polyethylene (PE) resin (Epolene C-10 available from Westlake Chemical Corporation). The polymer pellets were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 320° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL:PE ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 0.5 RPM's. This stream with 3 alternating layers was fed to a single orifice die which was maintained at about 320° F., and a voltage of 60 kV was applied to a flat plate collector placed 4 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 3 alternating PCL/PE layers.
Example 5
[0044] A melt electrospun fiber and web of the present invention was made using polyethylene (Epolene C-10 available from Westlake Chemical Corporation) and polypropylene (PP) resin (PP 3746G available from Exxon-Mobile Corporation). The polymer pellets and granules were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 392° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PE. The PE:PP ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 0.5 RPM. This stream with 3 alternating layers was fed to a single orifice die which was maintained at about 392° F, and a voltage of 60 kV was applied to a flat plate collector placed 3 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 3 alternating PE/PP layers.
Example 6
[0045] A melt electrospun fiber and web, comprising 3 layer fibers was prepared according to the procedure described in Example 5, except that PCL was substituted for PE, the PCL extruder temperature was maintained at 356° F., the PP extruder and feedblock temperatures were maintained at 428° F., the die temperature was maintained at 536° F., the voltage was 62 kV and the flat plate collector was placed 10 inches away from the die.
Example 7
[0046] A melt electrospun fiber web described in Example 1 was immersed in a water/isopropanol (w/w 90/10) mix and exposed to sonication using a Tekmar Sonic Disruptor at a setting of 3 for 30 minutes. FIG. 6 shows an SEM of the resulting material. Thick, ribbon shaped fibers are observed due to delamination of the layers.
Example 8
[0047] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polypropylene (PP) resin (PP 3746G available from Exxon-Mobile Corporation). The polymer pellets and granules were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 356° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL:PP ratio was maintained at a 50:50 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 1 revolution per minute (RPM). The layered melt stream was fed to a layer multiplier that had 7 multipliers, which cut and stacked the layered stream 7X and resulted in a melt stream that had 257 layers upon exiting the layer multiplier. The layer multiplier was maintained at about 356° F. This stream with 257 alternating layers was fed to a single orifice die which was maintained at about 356° F., and a voltage of 63 kV was applied to a flat plate collector placed 10 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 257 alternating PCL/PP layers.
[0048] A melt electrospun fiber web described in this Example 8 was immersed in a beaker of chloroform with a magnetic stirrer and exposed to gentle agitation for 30 minutes. FIG. 7 shows an SEM of the fibrous material where at least a portion of the layers of the multilayer melt electrospun fibers have been delaiminated.
Example 9
[0049] A melt electrospun fiber and web of the present invention was made using polycaprolactone (PCL) resin (CAPA 6250 available from Persorp UK Ltd) and polyethylene (PE) resin (Epolene C-10 available from Westlake Chemical Corporation). The polymer pellets were fed to two extruders connected to gear pumps to control the flow, which fed the melt streams to a 3 layer feedblock. Both extruders and the feedblock were maintained at about 356° F. The feedblock split the two melt streams and arranged them in an alternating fashion into a 3 layer melt stream on exiting the feedblock, with the outer layers being PCL. The PCL:PE ratio was maintained at a 1:2 ratio by adjusting the gear pumps and the flow rate of both gear pumps were maintained at 0.5 and 1.0 revolution per minute (RPM) respectively. The layered melt stream was fed to a layer multiplier that had 7 multipliers, which cut and stacked the layered stream 7× and resulted in a melt stream that had 257 layers upon exiting the layer multiplier. The layer multiplier was maintained at about 356° F. This stream with 257 alternating layers was fed to a single orifice die which was maintained at about 356° F., and a voltage of 65 kV was applied to a flat plate collector placed 10 inches away from the die to electrospin a fibrous web. The resulting web had each fiber comprised of 257 alternating PCL/PE layers.
[0050] A melt electrospun fiber web produced as described in this Example 9 was immersed in a beaker of chloroform with a magnetic stirrer and exposed to gentle agitation for 30 minutes. FIG. 8 shows an SEM of the fibrous material with delamination of at least a portion of the layers. | Fibers having two or more alternating polymer layers are formed by co-extrusion followed by electroprocessing. The fibers can be used as a non-woven mat or other substrate for a variety of applications. Delamination of the fibers using ultrasonication yields separated, micro and nanolayer, fiber ribbons which may also be used a non-woven mat or other substrate. | 3 |
BACKGROUND OF THE INVENTION
An improved drain field apparatus for filtering sewage water, so that by the time it leaves the drainage container, to either percolate into the ground or to drain off into a storm drainage system, the sewage water will be free of solids and will have a safe PH level. The inventive apparatus is designed to have modular prefabricated drain field containers that can sit beside each other or can be arranged in any desired configuration to fit within the owner's property.
SUMMARY OF THE INVENTION
Drain fields are commonly used in conjunction with a septic tank and distribution box in order to filter particulates from sewage water before the water enters the earth surrounding the drain field or the storm drain system. Drain fields typically consist of pipes or laterals with perforations along the bottom thereof, buried in a tile trench surrounded by a filter medium such as pea stone or sand. As explained more fully in the co-assigned U.S. Pat. No. 5,383,974, incorporated herein by reference, in such systems sewage water from a household is separated into solids, sewage water, and surface scum in the septic tank and then the sewage water travels from the septic tank to a distribution box. The distribution box then distributes the sewage water to the drain field where the sewage water is filtered before exiting the system. One problem with conventional drain fields is that the majority of the sewage water tends to be dispersed into the ground only along a short section of the overall drain field. This causes rapid erosion of the filter materials along this section, lessening the amount of filtering action. This "funneling effect" reduces the effectiveness of conventional drain fields and fixing the drain field requires the relatively expensive and time consuming process of digging up the drain field and replacing it with a new one. The present invention is an improved drain field that substantially eliminates these problems.
In the present invention, the conventional drain field is replaced with a series of modular drain field containers. The drain field containers are constructed of sturdy waterproof materials such as fiberglass or plastic. The water tight containers have top, bottom and side walls. The pipes from a distribution box enter each drain field container individually and dispense the sewage water across the length and width of the container. Filtering materials in the container ensure proper filtering of sewage water before the water can exit the water tight container through an outlet located at the bottom of the container. The containers can be arranged in any desired configuration on the owner's property all at the same depth. The tops of the containers are removable to allow easy access for maintenance or servicing of the system.
In accordance with the preferred embodiment of the instant invention, the container has a dispersal pan extending across a horizontal cross section of the container, located between the outlet of the distribution pipe and the filter in the drain field container. Sewage water from the distribution box is poured onto a cone at the center of the pan to distribute the water evenly across the pan. The pan has radial channels extending outwardly from the center cone to ensure even distribution of the sewage water across the pan. Within the radial channels are holes allowing the sewage water to fall from the pan onto the filter below. The diameter of the holes increases as the distance from the center cone increases to further ensure equal distribution of the sewage water across the filter.
In accordance with one embodiment of the invention, the container has an outlet on its bottom consisting of a pipe at one end. The bottom of the container narrows into a "V-shaped" channel to accumulate filtered sewage water. The channel slants downward to cause the filtered water to flow into the outlet. The outlet can then be attached to a pipe, which pipe can lead to a storm drain. This embodiment is designed for the areas of the country where storm drains are used.
In accordance with another embodiment of the invention, the outlet at the bottom of the drain field container consists of a series of holes to allow equal percolation of the filtered water into the ground. This embodiment of the invention is designed for those areas of the country where filtered sewage water is percolated directly into the ground.
Another aspect of the invention is the ability to bury all the drain field containers under ground at the same depth while maintaining equal distribution of sewage water among all the containers. To facilitate this aspect of the invention, the drain field containers may be constructed with additional distribution pipe connections for receiving distribution pipes leading to other drain field containers. This allows the containers to be buried in a straight line at the same depth while allowing equal distribution of sewage water to each of the drain field containers.
In another aspect of the invention, all the components of the system are made of waterproof materials such as fiberglass. These include the fasteners, for instance, bolts or clips, for removably securing the top to the rest of the drain field container. In a preferred embodiment, a bubble cover may also be provided. The bubble cover extends across the entire top of the container and is removably secured to the container. The bubble top prevents the top wall and its fasteners from being surrounded by compacted earth. Removal of the bubble top allows easy removal of the top of the container for maintenance or servicing, even in the worst of weather conditions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram of a prior art drain field system.
FIG. 2a is a cross sectional view of a prior art drain field that allows percolation into the ground.
FIG. 2b is a cross sectional view of a prior art drain field that is used in areas with storm drains.
FIG. 3 is a side view of the drain field container system of the present invention.
FIG. 4a is a top view of the drain field container system of the present invention where the drain field containers are assembled in a straight line.
FIG. 4b is a top view of the drain field container of the present invention where the drain field containers are assembled next to each other in a row.
FIG. 4c is a top view of the drain field container of the present invention where the drain field containers are assembled in a third configuration.
FIG. 5a is a side cross sectional view of a drain field container of the present invention for use in areas where filtered water percolates into the ground.
FIG. 5b is side cross sectional view of a drain field container of the present invention for use in an area where filtered water is released to a storm drain.
FIG. 6a is a front cross sectional view of the drain field container of the present invention for use in areas where the filtered water percolates into the ground.
FIG. 6b is a front cross sectional view of the drain field container of the present invention for use in areas where the filtered water is released into a storm drain.
FIG. 7 is a view of a filter cartridge for use with the present invention.
FIG. 8 is a top view of the disperser pan of the present invention.
FIG. 9 is a side view of the disperser pan of the present invention.
FIG. 10 is front view of the present invention with a bubble top.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In conventional prior art drain field systems, as shown in FIG. 1, the drain field 1 contains one or more drain field laterals 2, extending from a distribution box 3. The drain field laterals are buried in the drain field 1, also known as a tile field. As shown in FIG. 2a, each drain field lateral 2 consists of a slightly downwardly sloping pipe 4 typically having a diameter of 4 inches and a length of 50 feet. The drain field lateral 2 has series of holes along its bottom portion to allow sewage water from the distribution box to seep out of the lateral 2 into the drain field 1.
Each drain field lateral 2 is ordinarily buried about 20 to 30 inches below the ground level 14 in a long trench known as a tile trench 5. In colder climates, the drain field lateral 2 may be buried deeper to prevent the liquid in the pipe 4 from freezing. The drain field lateral 2 is placed in the tile trench 5 and surrounded by a filter bed 6 of gravel, sand or crushed stone to allow the sewage water to escape from the holes in the bottom portion of the drain field lateral 2. The filter bed 6 is then typically covered with a layer of untreated building paper or straw 7, which is itself covered with earth 8.
In use, sewage water passes from a household 9 into a septic tank 10, which separates the sewage water into solids, liquid, and surface scum. The sewage water passes from the distribution box 3 into the drain field lateral(s) 2. The sewage water then is distributed along the lateral 2 and dispersed through the holes in the laterals into the drain field 1. The sewage water is filtered of particulates as it passes through the sand or stone filter bed 6 in the tile trench 5. After passing through the drain field 1, the filtered sewage water percolates into the ground. In some areas, particularly where the ground has a high clay content that cannot absorb the water, the filtered sewage water is instead collected in pipe 12 below the lateral and released to a storm drain 13, as shown in FIG. 2b.
One significant drawback of the prior art system is that the majority of the sewage water tends to only be distributed into the drain field through only a small portion of the overall drain field lateral, normally the area closest to the distribution box. Because of the large quantity of sewage water that passes through the first series of holes in the drain field lateral 2, the drain field filter materials, typically sand or stone, tend to be eroded more quickly in these areas. With less sand or stone to impede the flow of sewage water through the holes in the bottom of the lateral, the rate of sewage water flow though this limited area increases, which causes an increase in the rate of erosion. This "a funneling effect" lessens the amount of filter materials, which in turn reduces the quality of filtering action, creating a potential health hazard. This is particularly true in those areas where storm drains are used. In order to restore the efficacy of the drain field, the drain field including the tile trench must be dug up, usually by using a backhoe. The drain field and drain field lateral must then be replaced. This is an expensive and time consuming process.
The present invention is an improvement on the prior art drain field system. In the present invention, as shown in FIG. 3, a series of modular drain field containers 20 are employed instead of the conventional drain field laterals 2. Each of these drain field containers 20 receives an equal volume of sewage water from the distribution box 3 to filter and disperse into the earth or storm drain. Each of the drain field containers 20 is designed to ensure the sewage water is properly filtered before releasing it into the earth or storm drain.
The drain field container 20 is constructed of a sturdy water proof material, for example, fiberglass or plastic, that will not rust or rot. As shown FIGS. 5a and 5b, the integral watertight container 20 consists of top 21, bottom 22, and side walls 23. Because the entire drain field container is watertight, rain water cannot funnel into the system and unfiltered sewage water cannot escape from the container. In a preferred embodiment of the invention, the drain field container 20 is constructed to be approximately 3 feet wide, and 8 to 10 feet long. At least a portion of the top 21 of the container 20 is designed to be removable by any known means to provide convenient access to the container 20 and its contents. In a preferred embodiment, the top 21 is removable by means of fasteners 24, for instance, bolts or clips. Preferably, the fasteners 24 are also constructed of fiberglass or plastic. A rubber 0-ring or similar seal can be employed around the perimeter of the container where the top 21 is fastened to the body to maintain the watertight integrity of the container.
The drain field container has at least one connection 25 for receiving a distribution pipe 30 from a distribution box 3. For example, as shown in FIGS. 5a and 5b, the distribution pipe 30 may enter into one side of the drain field container 20 near the top portion 21. The outlet 31 of the distribution pipe is over the center of the of the drain field container. In a preferred embodiment, as shown in FIGS. FIGS. 5a and 5b, the outlet 31 of the distribution pipe contains a funnel 32 for directing the stream of sewage water from the distribution pipe 30 into the drain field container 20.
As shown in FIGS. 5a and 5b, each drain field container 20 contains a filter 40 that extends across the bottom of the drain field container 20. The sewage water from the distribution pipe 30 pours onto the filter 40 and the filter 40 filters the sewage water. Because the sides of the drain field container 20 are waterproof, the water cannot seep out the sides of the container but must instead pass through the filter 40 in order to exit the container. The filter 40 contained in the drain field container 20 can be any conventional filter medium, including gravel, crushed stone, pea stone, or sand. In a preferred embodiment, as shown in FIG. 7, the filter 40 is specially designed to fit within the drain field container 20. The filter 40 can be constructed as a reusable synthetic fiber filter cartridge 41. For instance, the filter cartridge 41 can be constructed using a honeycombed nylon mesh 42 held in place by a plastic frame 43. This filter 41 can be coated with enzymes and special bacteria for treating sewage. The use of such a filter with the invention is particularly advantageous because the removable top allows the filter to be periodically cleaned and reactivated or changed without digging up the entire drain field system.
At the bottom of the drain field container is the outlet 50. For areas where the sewage water is permitted to percolate into the earth, a first embodiment of the invention is used, as shown in FIG. 5a and 6a, where a number of holes 51 are located on the bottom side of the drain field container below the filter. Sewage water passes from the distribution box 3 into the drain field container 20, where it pours onto the filter 40. The water passes through the filter 40 and passes out of the container 20 through the outlet holes 51 and into the ground.
In a second embodiment of the invention, for use in areas that employ storm drains, the outlet 50 consists of an outlet pipe 52, as shown in FIGS. 5b and 6b, that extends to the outside of the container 20 for connection to the storm drain 13. The bottom of the drain field container is slanted 53 towards the outlet pipe and may also be angled to form a V-shaped channel 54 to further ensure the flow of filtered water into the outlet pipe 51. The outlet pipe 51 is connected to the storm drain 13.
In a preferred embodiment of the invention, a disperser pan 60, as shown in FIG. 8 is employed between the filter 40 and the outlet 31 of the distribution pipe 30. As shown in FIGS. 5a, 5b, 6a, and 6b, the pan 60 extends across the entire horizontal cross section of the drain field container above the filter 40. The disperser pan 60 is used to distribute the sewage water across the entire top surface area of the filter to ensure no single area receives substantially more flow than another. As shown in FIGS. 8 and 9, the pan 60 preferably contains a cone 61 at its center, which is aligned with the outlet 31 of the distribution pipe 30. A series of channels 62 are formed in the pan extending radially outwards from the cone 61 in the center. The channels 62 contain a number of holes 63 that increase in diameter as the distance from the cone 61 increases. The holes 63 allow water to pass through the disperser pan 60 onto the filter 40. Sewage water exiting the distribution pipe 30 pours onto the cone 61 and the cone 61 distributes the water radially outwards from the center of the pan into the radial channels 62. The sewage water then is evenly distributed across the surface area of the filter 40 below when the sewage water drips through the holes 63 in the channels 62.
The drain field containers 20 are designed to be buried underground like drain field laterals. In a preferred embodiment of the invention, as shown in FIGS. 3 and 4a-c, five to six drain field containers 20 are used in a system. Each has a separate connection 25 to the distribution box through a distribution pipe 30. The distribution pipe connections 25 to the distribution box 3 are located at the same height in the box so that an equal volumetric flow leaves the box and, correspondingly, flows into each of the distribution pipes 30 and then flows into each of the drain field containers 20. As shown in FIG. 3, the distribution pipes 30 slant downwardly from the box at a slight angle, for instance 1 degree, to allow gravity flow into the drain field containers 20.
The separate distribution pipe connections 25 allow the drain field containers 20 to be buried at the same depth below ground, unlike drain field laterals 2 that are buried progressively deeper as the lateral extends further from the distribution box 3. In one embodiment, the drain field containers 20 may be buried just below the surface of the ground and covered with artificial turf. This allows easy access to the drain field containers 20 for maintenence or service. If the drain field containers 20 are buried beneath the earth, to service the containers, only enough earth needs be removed so as to expose the top 21 of the container. The fasteners 24 may then be removed and the top 21 taken off for easy servicing. In the alternative, as shown in FIG. 10, a bubble top 70 may be employed with the drain field container to protect the top 21 from being encrusted with compacted earth or mud. The hard plastic or fiberglass bubble top 70 extends over the top of the drain field container protecting the container top 21 and its fasteners 24 from the surrounding dirt or mud. Once the bubble top 70 is dug up and removed, the top 21 of the drain field container 20, including the fasteners 24, is free of dirt allowing immediate removal of the top portion. The bubble top 70 can be held on top of the drain field container 20 by any known means such as clips or locking seams such as those commonly found on plastic containers.
One advantage of the modular design of the drain field containers 20 with separate connections to the distribution box is that the containers can be arranged in any desired manner to fit the dimensions of the owner's property. As shown in FIG. 4b, the drain field containers can be aligned next to each other in a row or, as shown in FIG. 4c, they may be arranged in a different shape to accommodate the plot of land. In an another alternative, as shown in FIGS. 3 and 4a, the drain field containers can be arranged in a straight line extending outward from a house. When the drain field containers are to be arranged in a straight line, the containers may be constructed with additional waterproof distribution pipe connections 26, as shown in FIGS. 6a and 6b, to receive the distribution pipes of the succeeding drain field containers. The distribution pipes 33, 34, 35, and 36, of succeeding drain field containers pass through the container without having any outlet 31 to the container.
The inventive drain field container system described above has numerous advantages over the prior art drain field systems. First, the funneling effect is diminished because the sewage water from the distribution box is equally distributed among a number of containers. Second, the containers are waterproof modular units that are designed to distribute the share of sewage water received therein equally across the filter. Third, the modular drain field containers are designed so that at least a portion of the top is removable so the filter medium can be replaced, cleaned, or treated with enzymes to facilitate cleaning. Fourth, the modular containers are easily unearthed and do not require a backhoe to dig up a trench, and the containers, unlike drain field laterals, are designed to last nearly forever. Fifth, the watertight containers prevents sewage water from escaping without being properly filtered. Sixth, the drain field containers may be arranged in any desired configuration to best meet the space needs of the owner's property.
It will be apparent to one of ordinary skill in the art from the foregoing description that variations of the foregoing apparatus may be employed without departing from the scope of the present invention. In addition, dimensions and measurements are given by way of example only, and are merely representative of the various modes of the invention. | A drain field container system for use in filtering sewage water from a distribution box. A plurality of separate containers are used to receive equal amounts of sewage water from distribution pipes extending from a distribution box. Sewage water is dispensed from the distribution pipe onto a dispersal tray inside the distribution box. The dispersal tray ensures equal distribution of sewage water across a filter located below the dispersal tray and extending across a lower portion of the drain field container. Sewage water is filtered in the filter before exiting the drain field container from an outlet on the bottom thereof. The drain field containers are made of rugged waterproof materials such as fiberglass. The drain field containers have a removable top portion to allow easy servicing and maintenance. A bubble top may also be employed to prevent dirt from accumulating on top of the drain field container. The drain field containers may be buried under ground and arranged in any desired manner to conform to the dimensions of the owners property. | 4 |
BACKGROUND OF THE INVENTION
[0001] The present invention generally relates to the preparation of semiconductor grade silicon crystals, used in the manufacture of electronics. More particularly, the invention relates to a device for feeding arsenic dopant into an apparatus for producing low resistivity silicon crystals.
[0002] Silicon crystal growth using the Czochralski (CZ) method involves changing the characteristics and properties of the silicon ingot being grown by adding a dopant material to the molten silicon before silicon ingot growth. A common dopant material used in this process is arsenic. Arsenic, however, is a volatile substance and problems often arise through conventional methods of introducing the dopant to the silicon melt.
[0003] One such method is to dump the dopant from a port positioned above the melt. However, because of the high temperatures of the process, there is a violent loss of arsenic to the argon gas environment above the melt. This results in the generation of oxide-particles which can prolong and compromise the crystal growing process. Thus, this method is very inefficient.
[0004] Another method uses a quartz vessel containing the dopant above the melt for introducing the volatile gas to the melt. This method can reduce loss of vaporized dopant if the vessel has a port extending into the melt. Regardless, these methods result in complicated operation and loss of volatile dopant. The present invention overcomes these difficulties and disadvantages associated with prior art processes by introducing the dopant to the melt at an upper surface of the melt.
SUMMARY OF THE INVENTION
[0005] In one aspect, the present invention includes a feed assembly for feeding a dopant to a silicon melt in a crystal growing apparatus. The assembly comprises a vessel for holding and releasing a dopant solid material and an elongate feed tube operatively connected to the vessel. The feed tube comprises a fixed tube and a movable tube concentrically arranged with the fixed tube. The assembly also includes an actuator connected to the moveable tube for moving the moveable tube relative to the fixed tube for advancing the moveable tube toward an upper surface of the silicon melt in the apparatus and retracting the moveable tube away from the upper surface of the silicon melt to selectively position the moveable tube for introducing the dopant material released from the vessel to the silicon melt when the feed assembly is mounted on the crystal growing apparatus.
[0006] In another aspect, the present invention includes a method for feeding arsenic dopant to a silicon melt in a silicon crystal growing apparatus having a crystal growing chamber. The method includes placing granular solid arsenic dopant in a vessel attached to a feed tube comprising a fixed tube and a movable tube in concentric arrangement. The moveable tube is lowered toward the silicon melt with an actuator connected to the moveable tube to selectively position the moveable tube at the surface of the silicon melt. In addition, the dopant is released from the vessel to allow dopant to travel down the feed tube and into the melt at an upper surface of the melt.
[0007] In still another aspect, the present invention includes a method for feeding arsenic dopant to a silicon melt in a silicon crystal growing apparatus having a crystal growing chamber. The method comprises placing granular solid arsenic dopant in a vessel attached to a feed tube comprising a fixed tube and a moveable quartz tube having an angled tip. The fixed tube and moveable quartz tube are in concentric arrangement. Further, the method includes lowering the moveable tube toward the silicon melt with an actuator connected to the moveable tube to selectively position the moveable tube at the surface of the silicon melt. Still further, the method comprises releasing the dopant from the vessel to allow the dopant to travel down the feed tube to a catch located in the moveable tube for catching the dopant material when it is released from the vessel. In addition, the method comprises introducing argon gas into the feed tube below the vessel causing sublimation of the dopant resulting in dopant laden argon exiting the angled tip of the moveable quartz tube at an upper surface of the silicon melt.
[0008] In yet another aspect, the present invention includes a feed assembly for feeding a dopant to a silicon melt in a crystal growing apparatus. The feed assembly comprises a vessel for holding and releasing a dopant solid material and an elongate feed tube attached to the vessel. The feed tube includes a fixed tube and a movable tube concentrically arranged with the fixed tube. Further, the feed assembly includes a catch located within the moveable tube for catching the dopant material when it is released from the vessel.
[0009] Other objects and features will be in part apparent and in part pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a cross section of a first embodiment of a feed assembly in a retracted position;
[0011] FIG. 2 is a front view of a vessel-and-valve assembly of the feed assembly with a portion broken away showing the flow of dopant material;
[0012] FIG. 3 is a cross section of a second embodiment of the feed assembly in an extended position;
[0013] FIG. 4 is a perspective of the feed assembly attached to a crystal grower furnace chamber;
[0014] FIG. 5 is a perspective of the vessel-and-valve assembly and actuator of the feed assembly;
[0015] FIG. 6 is a perspective of an isolation valve of the feed assembly attached to the crystal grower.
[0016] Corresponding reference characters indicate corresponding parts throughout the drawings.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0017] Multiple embodiments for an arsenic dopant feed assembly are illustrated. FIG. 1 illustrates a first embodiment of an arsenic dopant feed assembly, generally designated by the reference number 10 . In the first embodiment, the dopant feed assembly 10 is fabricated from a refractory material that is non-contaminating and non-reactive with arsenic, silicon and graphite.
[0018] The first embodiment of the feed assembly 10 comprises a vessel-and-valve assembly 11 for holding dopant solid (not shown), and a feed tube assembly, generally indicated at 15 , attached to the vessel-and-valve assembly 11 for delivering the dopant to a silicon melt (not shown). An actuator 19 is operatively connected between the feed tube assembly 15 and a receiving tube 21 for advancing and retracting the feed tube assembly to and from an upper surface of the silicon melt. A brake assembly 25 is operatively connected between the actuator 19 and the receiving tube 21 for restricting movement of the feed tube assembly 15 and locking the feed tube assembly at a selected position. An isolation valve 27 is provided at a bottom of the feed tube assembly 15 . The valve 27 is configured for placing the feed assembly 10 in communication with a crystal growing apparatus 31 (see FIG. 6 ).
[0019] Referring to FIG. 2 , the vessel-and-valve assembly 11 includes a dopant cartridge 41 configured for holding the dopant solid and a valve 43 attached to the feed tube assembly 15 that can be opened to release the dopant down the feed tube assembly. The valve 43 has a handle 45 for opening and closing the valve.
[0020] The feed tube assembly 15 comprises a series of elongate concentric tubes including a fixed tube 51 and one or more moveable tubes 53 situated around the fixed tube and arranged in a telescoping fashion (see FIG. 1 ). The fixed tube 51 is closed at a first end 54 by a vacuum flange 55 and is received by the moveable tubes 53 at a second end 57 (see FIG. 3 ). An end cap 59 at the first end 54 attaches the fixed tube 51 to the receiving tube 21 . The end cap 59 includes a seat 61 having an opening 63 which receives the first end 54 of the fixed tube 51 . An annular seal 65 seals the opening 63 between the end cap 59 and the fixed tube 51 .
[0021] A vacuum fitting 67 connects each moveable tube 53 to an adjacent moveable tube. Each vacuum fitting 67 includes two opposing ring fittings 69 connected to each other by a threaded coupling 71 engaging threads 73 on the ring fittings. The embodiment illustrated in FIG. 1 shows two moveable tubes, however a single moveable tube or three or more moveable tubes are contemplated as being within the scope of the present invention.
[0022] The feed tube assembly 15 provides a passage 81 through which dopant material travels when it is released from the vessel-and-valve assembly 11 . An outlet 83 of the moveable tubes 53 is in fluid communication with the vessel-and-valve assembly 11 for introducing the dopant to the silicon melt (see FIG. 3 ). In this first embodiment, the feed tube assembly 15 can be made of any refractory material that is non-contaminating and non-reactive with arsenic, silicon and graphite. As will be explained in greater detail later, a moveable tube 53 ′ of the second embodiment that is positioned at the surface of the melt is fabricated from quartz.
[0023] Referring to FIG. 1 the actuator 19 comprises a linear translator 85 including an annular magnetic sleeve 87 attached to the moveable tubes 53 and an annular magnetic slide 89 adjacent and magnetically coupled to the sleeve. The magnetic sleeve 87 is sized and shaped for receiving the moveable tubes 53 in the sleeve. The sleeve 87 is secured to the moveable tubes 53 by friction fitting. The magnetic slide 89 is sized and shaped for receiving the receiving tube 21 and directly engages the outer surface of the receiving tube 21 . A small clearance 90 between the receiving tube 21 and the magnetic slide 89 allows the magnetic slide to slide along the length of the receiving tube. The slide 89 is aligned with the magnetic sleeve 87 , creating a magnetic coupling due to the opposite polarization of the two structures. This coupling secures the slide 89 to the receiving tube 21 at the same height that the magnetic sleeve 87 is positioned on the moveable tubes 53 . As a result, movement of the slide 89 along the receiving tube 21 causes the magnetic sleeve 87 to move under the force of magnetic attraction. As the slide 89 moves up and down the receiving tube 21 , the moveable tubes 53 slide away from and toward the fixed tube 51 for positioning a tip 91 of the moveable tubes 53 at the surface of the silicon melt (see FIG. 3 ). As will be explained in greater detail below, the magnetic slide 89 also includes an extension 93 having an annular teardrop shape with an aperture 95 at its tapered end. The aperture 95 is configured for attaching to the brake assembly 25 . Although the preferred embodiment of the invention incorporates the magnetically coupled linear translator, it is envisioned that other suitable actuators (e.g., mechanical, electrical, or electromechanical) could be used without departing from the scope of this invention.
[0024] Referring to FIG. 4 , the receiving tube 21 is an elongate tube made of stainless steel. The receiving tube 21 separates a portion of the actuator 19 and feed tube assembly 15 from the surrounding environment (see FIG. 1 ). The feed assembly 10 is illustrated as having two receiving tube members 99 connected in series. However, any number of receiving tube members 99 is foreseen. A first seal assembly 101 connects the receiving tubes 21 . The seal assembly 101 comprises an o-ring 103 and a clamp 105 having semi-circular clamp halves 107 . A second seal assembly 109 connects the receiving tube 21 to the isolation valve 27 . One clamp half 111 of the second seal assembly 109 has a threaded extension 113 for connecting the receiving tube 21 to the isolation valve 27 as will be explained in greater detail below.
[0025] Referring to FIGS. 1 and 5 , the brake assembly 25 comprises stops 121 , 122 positioned on the receiving tube 21 , a rod 123 (broadly, a “braking member”) disposed between the stops and a screw 125 (broadly, a locking member) engaging the braking member and the magnetic slide 89 for locking the slide at a selected position along the receiving tube 21 . Similar to the extension 93 on the magnetic slide 89 , the stops 121 , 122 have an annular teardrop shape with a central opening 127 at its bulbous end for receiving the receiving tube 21 and a hole 129 at the tapered end extending from a top face 131 to a bottom face 133 for receiving the braking member 123 . A side face 135 on the tapered end has an adjustment opening 137 . The stops 121 , 122 are positioned on the receiving tube 21 above and below the magnetic slide 89 . The braking member 123 passes through the hole 129 in the first stop 121 , the aperture 95 in the slide 89 and the hole 129 in the second stop 122 . Thus, the braking member 123 links the stops 121 , 122 to the slide 89 creating a track 139 to guide the slide along the receiving tube 21 .
[0026] The stops 121 , 122 are also adjustable. The central opening 127 is sized and shaped for receiving the receiving tube 21 . Similar to the magnetic slide 89 , a small clearance 140 between the stops 121 , 122 and the receiving tube 21 allow the stops to slide along the length of the receiving tube. On the receiving tube 21 the stops 121 , 122 can be slid to a selected position. Once the selected position for the stops 121 , 122 is achieved, a stop screw 141 can be inserted into the adjustment bore 137 to lock the stops in place. The tip of the stop screw 141 presses against the braking member 123 holding the stops 121 , 122 in position. The stop screw 141 can then be unscrewed to allow the stops 121 , 122 to move to another position on the receiving tube 21 and re-tightened to lock the stops in place again.
[0027] Referring to FIGS. 1 and 6 , in one embodiment the isolation valve 27 comprises a ball valve 151 having a body 153 and a passageway 155 with a ball 157 disposed in the passageway mounted for selective rotation between open and closed positions (illustrated embodiment shown in open position. A pair of valve seats 159 , 161 are provided in the passageway 155 on opposing sides of the ball 157 . In the preferred embodiment, the valve seats 159 , 161 are located substantially equidistant from an axis of rotation of the ball 157 and include radial openings 163 . The ball 157 and valve seats 159 , 161 are enclosed within the body 153 by a pair of end fittings 165 . The end fittings 165 can be mounted to the body 153 by any sufficient means. In the present invention, mounting bolts 167 are utilized. At least one end fitting 165 is also provided with internal threads 169 to facilitate connecting the isolation valve 27 to the feed tube assembly 15 by the threaded extension 113 on the second seal assembly 109 . It is understood that any other convenient means of connecting the isolation valve to the feed tube assembly is within the scope of the present invention.
[0028] A stem assembly 171 and handle 173 are provided for actuating the isolation valve 27 . The handle 173 is releasably secured to the stem assembly 171 by a nut 175 that clamps to the tip of a packing nut 177 and also helps to support the ball 157 in the body 153 . The ball 157 is supported in the passageway 155 such that the ball can shift axially along the passageway. The ball valve 151 can be manually actuated with the handle 173 , or an actuator (not shown) may be provided to actuate the valve. The positions of the handle 173 and the ball 157 are limited by a depending catch member 179 carried by the handle. The catch member 179 engages a surface of the body 153 to provide fixed stops for the isolation valve 27 .
[0029] The structure of the isolation valve as described above reflects a preferred embodiment. It will be readily apparent to those skilled in the art that changes and additions to the structure may be made to accommodate specific operational requirements. Such modifications are not deemed to affect the scope of the present invention.
[0030] Operation of this first embodiment of the feed assembly 10 is as follows. Once the silicon melting process is complete, the actuator 19 advances the moveable tubes 53 of the feed tube assembly 15 so the outlet 83 of the moveable tubes 53 is located at the upper surface of the silicon melt. The locking member 125 of the brake assembly 25 is tightened to lock the magnetic slide 89 in place, thus locking the outlet 83 of the moveable tubes 53 in position at the surface of the silicon melt. The dopant held in the vessel-and-valve assembly 11 is released when the valve 43 in the dopant cartridge 41 is opened. The dopant will travel through the feed tube assembly 15 , past an opened isolation valve 27 and into the silicon melt at the surface of the melt. The moveable tubes 53 are retracted by the actuator 19 and argon gas is released below the vessel-and-valve assembly 11 into the feed tube assembly 15 for cooling the assembly 10 . Finally, the assembly 10 is isolated from the crystal growing apparatus 31 by closing the isolation valve 27 .
[0031] As illustrated in FIG. 3 , a second embodiment of the feed assembly 10 ′ is designated in its entirety by the reference number 10 ′. The components of the second embodiment are exactly the same as the first embodiment except for a modified feeding tube assembly 15 ′. The feeding tube assembly 15 ′ of the second embodiment comprises a moveable tube 53 ′ made of a special quartz material. This material is used primarily to accommodate gas phase doping. The quartz tube 53 ′ is a thick walled clear fused quartz tube with an outside diameter of about 25 mm, a wall thickness of about 3 mm and a length of about 711 mm. This tube 53 ′ has an angled tip 91 ′ allowing a maximum melt surface area to be exposed to dopant gasses flowing from the tip. Additionally, the moveable tube 53 ′ includes a guide 201 aligning the quartz tube 53 ′ and a perforated disk 203 preventing the dopant from exiting the tube 53 ′ into the silicon melt 17 . When the dopant material trapped in the tube 53 ′, argon gas can be introduced into the feed tube assembly 15 ′ causing the dopant laden argon to travel down the feed tube assembly 15 ′ under sublimation and exit the angled tip 91 ′ at the upper surface of the silicon melt.
[0032] This second embodiment of the feed assembly 10 ′ operates as follows. The process is similar to the process described for the first embodiment except the actuator 19 advances the quartz tube 53 ′ of the feed tube assembly 15 ′ so the angled tip 91 ′ is positioned at the upper surface of the silicon melt. The locking member 125 of the brake assembly 25 is tightened to lock the magnetic slide 89 in position, thus locking the angled tip 91 ′ of moveable tubes 53 ′ in position at the upper surface of the silicon melt. The dopant held in the vessel-and-valve assembly 11 is released when the valve 43 in the dopant cartridge 41 is opened by the handle 45 . The dopant travels through the feed tube assembly 15 ′ and is collected on the perforated internal disk 203 . Argon gas is introduced into the feed tube assembly 15 ′ below the vessel-and-valve assembly 11 . Sublimation of the dopant will occur as the dopant is captured at the perforated disk 203 . This process results in dopant laden argon traveling past the opened isolation valve 27 and out the angled tip 91 ′ of the quartz tube 53 ′ at the upper surface of the silicon melt. After the dopant has undergone sublimation, the quartz tube 53 ′ is retracted by the actuator 19 and the feed tube assembly 15 ′ is cooled with the flow of argon gas. Finally, the assembly 10 ′ is isolated from the crystal growing apparatus 31 by closing the isolation valve 27 .
[0033] Having described the invention in detail, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims.
[0034] When introducing elements of the present invention or the preferred embodiments(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.
[0035] In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.
[0036] As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense. | A feed assembly and method of use thereof of the present invention is used for the addition of a high pressure dopant such as arsenic into a silicon melt for CZ growth of semiconductor silicon crystals. The feed assembly includes a vessel-and-valve assembly for holding dopant, and a feed tube assembly, attached to the vessel-and-valve assembly for delivering dopant to a silicon melt. An actuator is connected to the feed tube assembly and a receiving tube for advancing and retracting the feed tube assembly to and from the surface of the silicon melt. A brake assembly is attached to the actuator and the receiving tube for restricting movement of the feed tube assembly and locking the feed tube assembly at a selected position. | 8 |
BACKGROUND OF THE INVENTION
The present invention, subject of Disclosure Document No. 299257 which was filed on Jan. 13, 1992, relates to an excavation shoring system for use in excavation depressions such as construction pits and trenches, as well as cuts in sloped earthen banks, to provide worker safety from the hazard of cave in while occupying and working within the excavated depression or cut.
One of the current construction practices in traversing an established roadway with an underground pipe, conduit, cable or the like is to tunnel under the roadway rather than cut, trench, fill and repair thereby preserving the structural integrity of the road bed and surface and not shutting down use of the roadway during construction operations. If the roadway underground crossing site is located on flat terrain then it is necessary to prepare an excavation depression or pit on either side thereof and tunnel underneath. If the roadway is on an elevated earthen bed then tunneling may be accomplished directly therethrough. In either event, however, with the use of power boring and drilling equipment within an excavated depression or within a cut at an earthen slope, and for purposes of general worker safety, it is prudent if not necessary to provide shoring support for the excavation walls or sides of a sloped cut to reduce the danger from cave in.
The prior art shows various shoring systems of modular component assembly, typical of which are those respectively taught in U.S. Pat. No. 4,685,837 to Cicanese dated Aug. 11, 1987, and as shown in the Pit Excavation System brochure of Krings Construction systems of Bridgewater, N.J., both of which have solid side shoring panels and require heavy lifting and rigging equipment to accomplish erection and installation.
An additional feature of the applicant's excavation shoring system invention is that it employs the use of a grid type side shoring panel which itself is suitable for supporting many types of soils, and is adapted to slidably receive planks for providing increased shoring support with less stable soils. The shoring grid feature enables two advantages not realized by the foregoing teachings. First, the overall shoring system is lighter since solid sheet steel side panel members are not used and it can be installed and removed with lighter equipment and second the relatively open grid system to the extent it is not necessary to be planked allows for better visibility into the shored excavation depression when installing and removing men and material and equipment, which is an enhanced safety feature.
A prior art teaching which does show a slotted plank earth shoring system is that by Dorey in U.S. Pat. No. 2,246,623 dated Jun. 24, 1941, for a knockdown cribbing assembly for graves, which is both structurally and functionally distinguished from applicant's teaching, however, in that the shoring planks are not slidably installed only to the height needed and thereby no enhanced visibility feature is achieved.
Applicant's excavation shoring system invention, in both the preferred and alternate embodiment forms thereof, provides in each case individually and interchangeably, new and novel systems and apparatus for the safe and efficient flexibly adaptable shoring of both excavation depressions and sides of cuts in sloped earthen banks to provide worker and equipment protection against cave in.
SUMMARY OF THE INVENTION
It is the principal object of the present invention to provide an excavation shoring system which is assembled from modular components at surface level, and installed from the surface level, so that personnel are not required to be below ground until after the system is installed and the excavation depression is safely shored.
It is another object of the present invention to provide an excavation shoring system that enables maximum surface level visibility into an excavated depression, consistent with the safe shoring thereof, during the lowering and placement of equipment and material therein.
An additional object of the present invention is to provide an excavation shoring system that can be erected and installed at a job site location without the need for heavy rigging equipment.
It is also an object of the present invention to provide an excavation shoring system that is simple and rugged in both design and construction, is reusable, and has interchangeable modular components to provide maximum flexibility in adapting the use thereof for shoring in any kind of open static excavation environment.
It is a further object of the present invention to provide an excavation shoring system which is adapted to shore pits and trenches, or in an alternate assembly embodiment thereof provide shoring support for cuts in a sloped earthen bank.
It is yet another object of the present invention to provide an excavation shoring system which is easy to assemble and install, and use with safety and convenience.
The foregoing, and other objects hereof, will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a surface level perspective view of a partially assembled modular supporting frame component of the excavation shoring system comprising the instant invention as the same would typically appear at an exemplary excavation depression use installation site.
FIG. 2 is a perspective view similar to that as shown in FIG. 1, further illustrating completed assembly erection and installation of the excavation shoring system modular supporting frame component within the excavated depression.
FIG. 3 is a perspective view similar to that as shown in FIG. 2, further illustrating the progressive erection and installation of the excavation shoring system of instant invention within the excavation depression.
FIG. 4 is an enlarged end elevation view of the erected and installed excavation shoring system assembly as shown in FIG. 3 and seen along the line 3--3 thereof, being foreshortened to accommodate the view to the sheet.
FIG. 5 is an enlarged end perspective elevation view of the excavation shoring system of instant invention as the same would typically appear when fully erected in a use installation configuration within the exemplary excavated depression.
FIG. 6 is a perspective elevation view of the sloped earthen bank alternative assembly embodiment of the excavation shoring system of instant invention.
FIG. 7 is an enlarged top plan view of the modular support frame beam-to-post assembly, as shown in FIG. 6 and seen along the line 7--7 thereof.
FIG. 8 is an enlarged side elevation use employment installation view of the excavation shoring system sloped earthen bank alternative assembly embodiment, as shown in FIG. 6 and seen along the line 8--8 thereof.
FIG. 9 is an enlarged side elevation view of an angled support beam employed in the modular supporting frame of the excavation shoring system sloped earthen bank alternative assembly embodiment, being foreshortened to accommodate the view to the sheet.
FIG. 10 is a corresponding top plan view of the angled support beam as shown in FIG. 9.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1, a partially assembled modular support frame assembly 10 of the excavation shoring system 12 of instant invention is shown as the same would typically appear prepatory to the erection thereof at an exemplary use installation site 14, which in this case is illustrated as an excavation pit 16 prepared in a relatively flat terrain profile adjacent to a roadway 18 for purposes of tunneling thereunder to install an underground conduit or the like, wherein the component parts comprising the modular support frame assembly 10 are a set of four support feet 20 to each of which is affixed as an integral part thereof a centrally positioned upward projecting base post 22 being adapted to insertably engage and structurally support by collar plate openings 24 respectively provided therein at the opposing ends thereof a pair of support frame lower longitudinal beams 26 and a pair of support frame lower lateral beams 28. Once the lower longitudinal and lateral beams 26 and 28 are insertably assembled to the base posts 22 as shown in FIG. 1, which sub-assembly provides the modular support frame base 30, then post connecting sleeves 32 are respectively slidably assembled to the upward projecting ends 34 of the base posts 22 and then by means of inserting a connecting pin 36 through aligned cooperative pin openings 38 respectively in the upward projecting end 34 of the base posts 22 and the lower end of the connecting sleeve 32, which thereby locks the respective corners 40 of the modular support frame base 30 between the upper surface of the support feet 20 and said connecting pin 36 so the modular support frame base 30 may be mechanically lifted and positioned in the excavation pit 16 for continued assembly and completed erection of the modular support frame assembly 10. Additional components of the modular support frame assembly 10 as shown in FIG. 1 are the vertical frame posts 44 which are manually assembled insertably into the four corner 40 post connecting sleeves 32 from the surface level 46 once the assembled modular support frame base 30 has been mechanically lowered into installed position in the excavation pit 16, as shown in FIGS. 2 and 3 and will hereinafter be more fully explained, following which the upper longitudinal beams 48 and the upper lateral beams 50 are thereafter successively installed upon the upward projecting vertical frame posts 44, also from surface level 46, which then completes the assembly and operational erection of a single modular support frame assembly 10 unit of the excavation shoring system 12.
It will additionally be noted, as best shown by the unassembled upper lateral beams 50 illustrated in FIG. 1, but which also applies to the lower lateral beam 2B structures, that the collar plates 42 weldably affixed to the lateral end upward surfaces respectively thereof extend beyond the beam 28 and 50 ends by an amount which is equivalent to the thickness of the longitudinal beams 26 and 48 so that there is a recessed fitting of the longitudinal beams 26 and 48 to the lateral beams 28 and 50 as is best shown by the assembled modular support frame base 30 as also seen in FIG. 1 and certain subsequent Figures hereinafter. The recessed beam fitting feature as above described enables a more compact and rigid modular support frame assembly 10.
Two advantageous features obtained in use of the excavation shoring system 12 hereof are first, the assembly and installation of the system 12 and component parts thereof is achievable with the use of commonly available construction site equipment such as a back hoe and does not require the use of heavy duty rigging equipment such as cranes and the like and second, no personnel are required in the excavation pit 16 until the system 12 is operationally installed since completion of assembly is accomplished from the surface level 46.
Considering now FIG. 2, which shows a modular support frame assembly 10 fully erected and installed in operational use position within the excavation pit 16, having been put together in the manner as previously described. Once the frame assembly 10 is thus positioned, then a shoring grid 52 is mechanically lowered into position in the excavation pit 16 between the pit wall 54 and one of the lateral side vertical profiles of the modular support frame assembly 10. As shown, the shoring grid 52 is a relatively open structured panel weldably fabricated from rod material such as steel reinforcing bar of an appropriate size, formed to provide a pattern of spaced pairs of vertical bars 56 joined to either side of an interiorly spaced plurality of single horizontal bars 58 in such a manner as to thereby form a stacked elongated pocket structure for slidably receiving and supportably holding inserted shoring planks 60, whereby mechanical handling of the shoring grid 52 for moving and positioning is accomplished by relative ease with a back hoe 62 and cable connection 64, also as shown in FIG. 2.
In many shoring applications use of the shoring grid 52 in combination with the erected modular support frame assembly 10 is sufficient to provide adequate and safe pit wall 54 shoring support. In the case of less stable soil conditions, however, an additional use of the shoring planks 60 installed within the shoring grid 52 elongated pocket structure as shown in FIG. 3, to that height necessary and appropriate, provides the required pit wall 54 shoring support for whatever soil stability conditions may be encountered.
Considering now in greater detail the illustration shown in FIG. 3, which is of the partially installed and operationally erected excavation shoring system 12 of instant invention with one modular support frame assembly 10 fully installed in support of a single planked shoring grid 52 and the assembled modular support frame base 30 for a second such assembly 10 being mechanically lowered by means of a back hoe 62 and cable connection 64 for positioning and adjacent installation within the excavation pit 16. In the foregoing respect it should be noted that the excavation shoring system 12, because of the modular assembly nature thereof in accommodating the same to excavation pits 16 of varying sizes and shapes, as well as the nature of the work to be performed, may be comprised of but a single modular support frame assembly 10 with complementary shoring grids 52 and shoring planks 60, or a plurality of such modular support frame assemblies 10 with complementary shoring grids 52 and shoring planks 60 as necessary, and the showing of two such units in the installation and erection profiles as depicted is to be considered as exemplary only and not restrictive. As also shown in FIG. 3, both the lower and upper longitudinal beams 26 and 4B as well as the lower and upper lateral beams 28 and 50 are respectively provided with cable connecting eye bolts 66 to facilitate assembling cable connection 64 thereto for mechanical movement and positioning of the various excavation shoring system 12 component pieces and sub-assembly units.
Considering now FIG. 4, being an enlarged end elevation view of the erected and installed excavation shoring system 12 assembly in an operable pit wall 54 shoring profile, wherein shoring planks 60 have been insertably installed within shoring grid elongated pockets 6B to provide additional shoring support as was previously described. In the event use of shoring planks 60 is deemed prudent or necessary to provide additional support capability to the shoring grid 52, the height to which such planks 60 are installed is to that height appropriate for providing the additional protection sought and may be part way up the pit wall 54, or all the way up as illustrated in FIG. 4. The advantage, however, of using only the shoring grid 52 alone when planks 60 are not required, or using planks 60 only to the height necessary, is that surface level 46 observation through the open shoring grid 52 mesh into the pit 16 is thereby relatively unobstructed, which is a safety consideration and feature of the instant invention when personnel are occupying the shored excavation pit 16 during placement of equipment and material therein. Also shown in greater detail in FIG. 4 is the lateral beam 28 and 50 collar plate 42 recessed longitudinal beam fitting feature as previously described on consideration of FIG. 1.
Turning attention now to the end perspective view of FIG. 5 showing the excavation shoring system 12 fully erected in a typical use installation configuration within the excavation pit 16, with a piece of boring machine equipment 70 positioned in the pit 16 for use in tunneling a conduit opening beneath the roadway 18. As shown in FIG. 5, and as is customary in use application of the excavation shoring system 12 hereof, the pit wall working face 72 is also shored in order to thereby provide facilitated equipment access thereto with safety from pit wall cave in hazard, wherein an equipment passage opening 73 is cut in the shoring grid 52 in order in this case to pass the auger head 71 of the boring machine 70. Following job completion the equipment passage opening 73 in the shoring grid 52 may be closed by rewelding in lengths of vertical and horizontal bars 56 and 58 as appropriate.
The view shown in FIG. 6 is that of the sloped earthen bank shoring system 74 alternate assembly embodiment of the instant invention, and utilizes the basic structural components of the excavation shoring system 12, along with some additional modified components such as the angled support beams 76, to provide a support system particularly well adapted to shoring sloped earthen banks such as roadway or railway embankments and the like when boring, cutting or tunneling conduit passages thereunder.
As shown in FIGS. 6 and 8, a modular support frame base 30 as previously described in structure and assembly serves as the foundation platform upon which the remainder of the sloped earthen bank shoring system is erected. Once the modular support frame base 30 is assembled and positioned at the pit wall working face 72 as illustrated in FIG. 8, then a set of vertical frame posts 44 are insertably installed within the corresponding pit wall face post connecting sleeves 32 and retainably secured therewithin by means of insertable connection with connecting pins 36 through sleeve and post cooperatively aligned pin openings 38. Thereafter, upwardly disposed connecting pins 36 are inserted through the lowermost disposed vertical frame post 44 upward pin openings 38 to thereby serve as support stops for the upper lateral beam 50 upon which in turn is assembled the angled support beam upper connecting flange 80 by means of the post slot 82 therein receivably engaging the vertical frame post 44 with the upper connecting flange slot ears 84 being supported upon the top surface of the upper lateral beam 50 as shown in greater detail in the enlarged top plan view of FIG. 7.
Next, the rearward disposed lower lateral beam 28 of the modular support frame base 30 is removed and the respective angled support beams 76 are rotatably aligned about the post slot pivots to bring the base post slot 86 of the angled support beam lower connecting flange 88 of each such beams 76 into receivable aligned engagement with the corresponding upward projecting base posts 22 so that the lower connecting flange slot ears 90 respectively thereof supportably rest upon the lower longitudinal beams 26 and are then compressively secured in retained position thereupon by re-assembly of the rearward disposed lower lateral beam 28 as respectively shown in FIGS. 6 and 8. Structural detail of an angled support beam 76 with the respective upper and lower connecting flanges 80 and 88 assembled thereto is as shown in FIGS. 9 and 10.
Finally, also as shown in FIGS. 6 and 8, shoring grids 52 with shoring planks 60 as appropriate and necessary are installed to provide pit side wall 92 support. Again, as with use employment of the previously described excavation shoring system 12, the pit wall working face 72 in use of the sloped earthen bank shoring system 74 is also shored to likewise provide facilitated excavation and boring equipment access thereto with safety from working face 72 cave in hazard.
Although the excavation shoring system and the sloped earthen bank shoring system alternate embodiment thereof, as well as the respective structural characteristics and methods of assembly and use employment thereof, have been shown and described in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made respectively therefrom within the scope of the invention, which is not to be limited per se to those specific details as described herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent such devices, apparatus, and methods. | An excavation shoring system comprised of a modular support frame having longitudinal and lateral beam members provided with collar sleeve openings adapted to slidably receive vertical support pipes which in turn are provided with regularly spaced vertical openings for insertably receiving stop pins in setting vertical height adjustment retention of the longitudinal and lateral beam members of the support frame to accommodate an excavation pit depth when assembling the support frame for placement use in vertically holding shoring grids to retain the exposed earthen walls of an open pit, which shoring grids are in turn adapted to receive slidably inserted planks within the grid slot structure thereof in further providing additional retentive support for unstable soils. | 4 |
BACKGROUND OF THE INVENTION
This invention relates generally to a process for removing water from a mechanical pulp, chemical pulp or paper sheet. More particularly, the present invention relates to a process for removing such water in a first zone, where the mechanical pulp, chemical pulp or paper sheet runs, for example, between two wires in a dewatering machine and is dewatered advantageously in a wedge zone, i.e. a sector in which the two wires converge in a wedge shape. In addition, the invention refers to a device for implementing the process.
A device of this kind is known, for example, from WO 00/77298, where initial dewatering takes place in a gravity zone and further dewatering in a twin-wire zone. This is followed by dewatering in further zones. A device for dewatering purposes is shown here at the top wire where the water from the wire is directed as a so-called free jet into a dewatering box and drained off from there. Only the water collecting on the wire (surface of the wire) is carried off here. A large quantity of water, however, remains in the wire, which later causes re-wetting of the mechanical pulp, chemical pulp or paper sheet.
SUMMARY OF THE INVENTION
The aim of the invention is thus to remove also a substantial quantity of the water from the wire (wires) economically and boost the overall dewatering performance of the pulp dewatering machine (plant).
The invention is thus characterized by the water at the end of the first dewatering zone or adjoining it being removed from at least one wire by a vacuum, where the water is directed to the inner chamber of a suction box by the air current generated in the wire. As a result, re-wetting of the mechanical pulp, chemical pulp or paper sheet to be dewatered can be greatly reduced.
An advantageous further development of the invention is characterized by water being extracted simultaneously from the top and bottom wire. This guarantees favorable, even and rapid dewatering of the mechanical pulp, chemical pulp or paper sheet.
A favorable configuration of the invention is characterized by the water being extracted immediately after the wedge zone. If the water is extracted directly after the wedge zone, dewatering performance can be further enhanced as there is no re-wetting in the meantime.
A favorable further development of the invention is characterized by the air flowing through the wire in the opposite direction to that in which the wire is running. As a result, a larger quantity of water can be extracted from the wire.
An advantageous configuration of the invention is characterized by several suction points being located one behind the other on a wire. In this way it is possible to achieve maximum possible dewatering of the wire and thus, largely prevent any re-wetting of the mechanical pulp, chemical pulp or paper sheet to be dewatered.
The invention also refers to a device for removing water from a mechanical pulp, chemical pulp or paper sheet, running, for example, between two wires in a dewatering machine, where it is an advantage if the first dewatering zone is designed as a wedge zone, i.e. a sector in which both wires converge in a wedge shape, characterized by at least one suction box, connected to a vacuum source and with suction opening facing the wire, being provided immediately following the first dewatering zone, which is preferably a wedge zone. As a result, re-wetting of the mechanical pulp, chemical pulp or paper sheet can be greatly reduced.
An advantageous further development of the invention is characterized by the suction opening of the suction box resting directly on the wire. Thus, misrouted currents can be avoided and removal of moisture from the wire (wires) substantially improved.
A favorable configuration of the invention is characterized by at least one suction box being located immediately after the wedge zone. If the water is extracted directly after the wedge zone, the dewatering capacity can be increased even further as there is no re-wetting whatsoever in the meantime.
A favorable further development of the invention is characterized by at least one suction box each being mounted at the top and bottom wire. This guarantees favorable, even and rapid dewatering of the mechanical pulp, chemical pulp or paper sheet.
An advantageous configuration of the invention is characterized by several suction boxes being mounted one after the other on one wire. This achieves maximum possible dewatering and largely prevents re-wetting of the mechanical pulp, chemical pulp or paper sheet.
An advantageous further development of the invention is characterized by the suction opening having a duct mounted diagonally and directed against the wire running direction.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention may be better understood and its numerous objects and advantages will become apparent to those skilled in the art by reference to the accompanying drawings in which:
FIG. 1 is a schematic view of a dewatering machine;
FIG. 2 is a schematic view of a first embodiment of the bottom suction box of FIG. 1 ;
FIG. 3 is a schematic view of a combination of two bottom suction boxes, one mounted on top of the other;
FIG. 4 is a schematic view of a combination of groups of two bottom suction boxes, mounted one behind the other;
FIG. 5 is a schematic view of a second embodiment of a bottom suction box on a Fourdrinier wire;
FIG. 6 is an enlarged view of a portion of the suction box of FIG. 5 ;
FIG. 7 is a schematic view of a Fourdrinier wire dewatering machine having the suction box of FIG. 5 ;
FIG. 8 is a schematic view of a twin-wire dewatering machine having the suction box of FIG. 5 ; and
FIG. 9 is an enlarged view of a portion of the twin-wire dewatering machine of FIG. 8 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a complete dewatering machine 10 in the form of a Fourdrinier machine. The material to be dewatered is spread on the wire 3 through a headbox 11 at a consistency of 0.4–2.5% and subsequently forms a sheet of mechanical pulp, chemical pulp or paper 2 , which is to be dewatered and dried as far as possible. In order to remove the water, suction boxes 12 , 12 ′ are mounted under the wire 3 . The invention is inserted at the end of the first dewatering zone 13 , designed for gravity dewatering. A press section 14 with at least one suction press roll adjoins this dewatering zone 13 . Mechanical dewatering is concluded with a high-pressure dewatering press 15 . The dryness here is approximately 55–57% for a pulp sheet and approximately 40–45% for a paper sheet, which achieves an increase of 2 to 3 percentage points compared with a plant not using the invention. Mechanical dewatering is followed by thermal drying in a dryer 16 .
FIG. 2 shows the arrangement of a suction box 5 at a wire 3 on which a mechanical pulp, chemical pulp or paper sheet 2 to be dewatered is transported. In addition, however, another wire (not shown) can run on the upper side of the mechanical pulp, chemical pulp or paper sheet 2 , i.e. the mechanical pulp, chemical pulp or paper sheet 2 is carried between two wires 1 , 3 . In the suction chamber 4 of the suction box 5 a vacuum Pi, compared to the atmospheric pressure P 2 , is applied. Due to this vacuum P., air from outside is sucked through the wire 3 into the suction chamber 4 (arrow L) through a suction opening 6 resting on the wire 3 . The air extracted also carries interstitial water from the wire 3 . Here, it is an advantage if the air flows against the running direction A of the mechanical pulp, chemical pulp or paper sheet 2 . If a suitable vacuum P 1 is selected, the greater part of the water held in the wire 3 can be removed and discharged from the machine. As a result, re-wetting of the mechanical pulp, chemical pulp or paper sheet 2 can be greatly reduced.
FIG. 3 shows an arrangement of two opposing suction boxes 5 , 5 ′ in a twin-wire dewatering machine. Analogous to removal of water from the bottom wire 3 according to FIG. 2 , the water is also removed here from the top wire 1 . Here, too, the water contained in the wire 1 is sucked into the suction chamber 4 ′ of the suction box 5 ′ by the air current passing through the wire. As a result, a large part of the water contained in the top wire 1 can also be removed and re-wetting of the mechanical pulp, chemical pulp or paper sheet to be dewatered can be curtailed.
In FIG. 4 there are two suction boxes 5 , 5 ′ mounted one behind the other at both the top wire 1 and the bottom wire 3 . As a result, even more water can be removed from the wires.
As a basic principle, only two suction boxes can be used one behind the other at the top or bottom wire, offset against one another at the top and bottom wire, or three suction boxes where two are at the bottom wire and one at the top wire or vice versa. It is also possible to mount additional suction boxes one behind the other if required. In order to enhance water removal it would also be possible to apply different vacua, where it is an advantage to increase the vacuum in the running direction of the sheet.
FIG. 5 shows the layout at the end of a Fourdrinier machine, where the mechanical pulp, chemical pulp or paper sheet 2 is dewatered on a (bottom) wire 3 . Here, a suction box 12 ′ is shown, which extracts the water from the sheet 2 through several openings 20 into the suction chamber 4 . During this process the wire runs on strips 21 , the last of which 21 ′ also serves to seal off the entire suction box against the surrounding area and is designed such that air L is sucked through the wire 3 into the suction chamber 4 and thus, carries a large part of the water contained in the wire 3 along with it. This has the effect of keeping subsequent re-wetting of the mechanical pulp, chemical pulp or paper sheet 2 by the water still contained in the wire 3 very low, thus the dewatering machine achieves a higher dryness overall at the end of the dewatering machine than machines that are currently state of the art.
In FIG. 6 the situation at the end of the suction box 12 ′ is illustrated once again in detail.
The vacuum applied in the suction box is up to 0.5 bar (50 kPa). A suction box on the bottom wire, for example, yields an increase in dryness at the end of the dewatering machine of approximately 2–3 percentage points. If two suction boxes opposite one another are used in a twin-wire press plant' the increase in dryness is roughly 3–4 percentage points. With two pairs of suction boxes, the dry content can be increased by 4–6 percentage points. If more suction boxes are used, it is possible to increase the dryness by up to 8 percentage points. The effect of the suction boxes is boosted at higher machine speeds, the usual speeds normally being between 150 and 250 m/min, however the effect of the suction boxes was excellent at least up to a sheet speed of 350 m/min. A maximum speed limit has not been determined to date, i.e. the suction device according to the invention can also be used at higher speeds.
FIG. 7 once again shows the situation in a gravity dewatering zone 13 of a Fourdrinier machine 10 , with the invention being applied in section 17 , i.e. at the end of this zone 13 . Here the last three suction boxes 12 ′, for example, can be designed according to the invention.
FIG. 8 shows a different type of dewatering zone 13 , which has two wires, i.e. twin-wire dewatering. The advantage of this form is even dewatering of the mechanical pulp, chemical pulp or paper sheet 2 , both upwards and downwards, which results not only in better quality, but also in higher production rates. This type of plant is used primarily in dewatering chemical pulp sheets as these are thicker and thus, have longer dewatering paths for the water they contain. Here, the material to be dewatered is fed in between the two wires 1 , 3 through a headbox 11 . The wires run over plates 22 , 23 whose spacing from each other decreases in the running direction of the sheet, i.e. they converge in a wedge shape. As a result, increasing pressure is applied to the sheet 2 , resulting in continual dewatering. The water drains off upwards and downwards through openings in the plates 22 , 23 . Additional suction boxes 5 are located at the end of this (wedge) zone. This illustration shows four suction boxes 5 mounted according to FIG. 4 . The bottom suction boxes are covered by the remaining machine parts and thus, are not visible here.
FIG. 9 contains detail IX from FIG. 8 with the suction boxes 5 . These suction boxes 5 are located directly adjacent to the first dewatering zone 13 . The illustration shows the suction channels 24 that open onto the top wire 1 and are connected to the suction chamber 4 of the suction boxes 5 . The air from the surrounding area is fed in here through an appropriate air inlet slot 25 . At least one inlet duct located upstream of a suction opening at the last suction box 5 , the air is sucked in through a slit 25 ′. The illustration also indicates that there are suction channels 24 and feed channels 25 at the bottom wire 3 . Additional suction boxes 5 can easily be added later if necessary.
The invention is only described by means of examples and may also cover other designs of suction box in the claims, in particular other detailed designs. | A process and apparatus for removing water from a mechanical pulp, chemical pulp or paper sheet, carried between top and bottom wires running through a dewatering machine having a first dewatering zone. The apparatus includes at least one suction box positioned downstream of the first dewatering zone. The process includes generating an air current in at least one of the wires downstream of the first dewatering zone with the suction box. The air current removes water from the wire and directs it into an inner chamber of the suction box. The invention also refers to a device for implementing the process. | 3 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to an apparatus and method thereof for detecting an error that occurs to a power converter, and more particularly, to an apparatus and method thereof for detecting if a current sensing resistor of a power converter is grounded.
[0003] 2. Description of the Prior Art
[0004] FIG. 1 is a diagram of a conventional fly-back power converter 100 . Fly-back power converter 100 transforms AC input voltage VAC into DC output voltage V OUT through switching transistor Q 1 . More specifically, energy of rectified input DC signal V I is stored in primary winding Lp of transformer T while transistor Q 1 is on, and then the stored energy is delivered to secondary winding Ls of transformer T to form output voltage V OUT while transistor Q 1 is off.
[0005] The gate of transistor Q 1 is coupled to pulse width modulation (PWM) control chip 110 for receiving a PWM signal generated from PWM control chip 110 . In this way, transistor Q 1 will be alternately turned on and off due to the PWM signal. PWM control chip 110 makes the fly-back transformer 100 generate the expected output voltage V OUT by adjusting the duty cycle of the PWM signal according to the voltage level of the current output voltage V OUT and the primary winding current Ip detected by current sensing pin CS.
[0006] However, in a case where current sensing resistor R CS coupled to current sensing pin CS is grounded due to mechanical failure or improper operation, resulting in the source of transistor Q 1 being directly shorted to ground, current sensing pin CS cannot detect the over-current status of primary winding current Ip. Hence, PWM control chip 110 may continuously send the PWM signal with a maximum duty cycle to alternately switch transistor Q 1 between on and off states, raising output voltage V OUT and even affects operation of circuit(s) coupled to an output port of fly-back power transformer 100 .
[0007] One conventional solution to this problem is to determine if voltage V CC supplied by an auxiliary winding Laux of the transformer T exceeds an over voltage protection threshold. Because part of the energy in primary winding Lp is also delivered to auxiliary winding Laux while delivering the energy to secondary winding Ls, auxiliary winding Laux charges voltage V CC at the same time when secondary winding Ls charges output voltage V OUT . Hence, when detecting that voltage V CC is higher than the over voltage protection threshold, PWM control chip 110 expects that too much energy is being transferred to both secondary winding Ls and auxiliary winding Laux, and that result could be due to the failure of the current sensing resistor R CS . Accordingly, an over voltage protection to voltage V CC may be enabled to decrease duty cycle of the PWM signal or turn off transistor Q 1 , lowering the energy transferred in the following switching cycles.
[0008] A disadvantage of this solution, however, is that over voltage protection threshold of V CC is set much higher than a normal operational voltage. Thus, for designers, it is very complicated or hard to determine the turn ratio of primary winding Lp to auxiliary winding Laux for differentiating the condition for the over voltage protection from that for the normal operation, taking consideration to both the situations that current sensing pin CS properly functions and that current sensing pin CS is grounded. Besides, during startup, the voltage level of the voltage V CC must be high enough to enable PWM control chip 110 when output voltage V OUT is still around zero. Hence, when the primary winding starts transferring energy stored therein, the diode DSN on the secondary side is turned on quicker than the diode DA on the auxiliary side, causing the secondary winding to gain energy stored in the primary winding before the auxiliary winding does. As a result, the output voltage V OUT rises earlier than the voltage V CC . It is possible that, when the voltage V CC exceeds the preset over voltage protection threshold to enable the over voltage protection, output voltage V OUT , which rises earlier, has already gone over high and adversely influences the circuit(s) coupled.
SUMMARY OF THE INVENTION
[0009] According to one embodiment of the invention, an apparatus applicable to a power converter is provided, wherein the power converter comprises a primary winding for receiving an input voltage and a secondary winding for generating an output voltage to power a load. The apparatus comprises: a detecting circuit, a comparing circuit, and a determining circuit. The detecting circuit is configured to generate a feedback signal according to the output voltage. The comparing circuit is coupled to the detecting circuit and configured to compare the feedback signal and a threshold. Accordingly, the comparing circuit generates an indication signal indicative of a fault condition that the output voltage is over high. The determining circuit, in response to the indication signal, is configured to trigger an over voltage protection mechanism for preventing the power converter from powering the load.
[0010] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various Figures and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a diagram of a conventional fly-back power converter.
[0012] FIG. 2 is a block diagram illustrating one embodiment of a detecting apparatus according to the present invention.
[0013] FIG. 3 is a diagram illustrating an exemplary embodiment of an internal circuit of the detecting apparatus in FIG. 2 that is applied to a fly-back power converter.
[0014] FIG. 4 is a diagram illustrating waveforms of a feedback signal, an indication signal, an output signal of a flip flop, an error detecting signal, and a power-good signal.
DETAILED DESCRIPTION
[0015] The detecting apparatus 200 in FIG. 2 uses a feedback signal representing the output voltage of the power converter to serve as a detecting target. The detecting apparatus 200 determines if the output voltage is over high and therefore a corresponding over voltage protection would be enabled by comparing the feedback signal with a threshold.
[0016] The detecting apparatus 200 includes a detecting circuit 210 , a comparing circuit 220 and a determining circuit 230 . Detecting circuit 210 generates a feedback signal according to output voltage Vout of a power converter (not shown in FIG. 2 ). Comparing circuit 220 compares the feedback signal with a threshold and accordingly generates an indication signal indicative of a fault condition that output voltage Vout is over high. Determining circuit 230 , in response to the indication signal, determines whether to trigger an over voltage protection mechanism that prevents the power converter from powering the load that the power converter originally powers. For example, when detecting that output voltage Vout is over high, detecting apparatus 200 controls a PWM control chip of the power converter to adjust the time period of turning on the power transistor coupled to the primary winding of the power converter or to constantly turn off the power transistor, thereby lowering the voltage level of the output voltage to a safe range. By this way, the over-high output voltage Vcc, whose root cause is believed to be a failed current sensing resistor that has almost zero-ohm resistance, could be avoided.
[0017] FIG. 3 is a diagram illustrating an exemplary embodiment of an internal circuitry of the detecting apparatus 200 applicable to the fly-back power converter shown in FIG. 1 . Detecting circuit 210 includes a regulator 212 with three-terminal shunt regulator 213 , and a photo coupler 214 with light emitting diode (LED) 215 , corresponding elements of which can be found in FIG. 1 . While the output voltage V OUT of the power converter is greater than a reference voltage V REF , the sink current of the regulator 213 increases accordingly, making the light emitting diode (LED) 215 of the photo coupler 214 become brighter and generating a current I corresponding to the output voltage V OUT at the output end of the photo coupler 214 due to photo-electric conversion. As the output end of the photo coupler 214 is further coupled to an impedance component (e.g., a resistor R) and a voltage source 216 , the feedback signal FB generated by the detecting circuit 210 is inversely proportional to the output voltage V OUT , which means that the higher the output voltage V OUT , the smaller the voltage of the feedback signal FB. Therefore, the voltage level of the feedback signal FB could drop to a value close to a ground potential when output voltage V OUT is higher than an over voltage protection threshold. Please note that, compared to the detection to the voltage V CC of the conventional auxiliary winding, this embodiment of the present invention can react rapidly and correctly in response to the magnitude of the output voltage V OUT because the feedback signal FB and the output voltage V OUT are instantly responsive to each other.
[0018] Feedback signal FB generated by detecting circuit 210 is fed into comparing circuit 220 , which—as mentioned above—generates an indication signal Ind by comparing the voltage level of the feedback signal FB with a threshold. In this exemplary embodiment, comparing circuit 220 includes transistor Qc, transistor Qd, a current source 221 , inverter 222 and inverter 224 , where the aforementioned threshold is the threshold voltage Vth of transistor Qc. Transistor Qc has a control end (gate) receiving the feedback signal FB, and two ends respectively coupled to current source 221 and ground. Transistor Qd has a control end (gate) controlled by the inverse signal of a power good signal, and two ends respectively coupled to current source 221 and ground. Turning on of any one of transistors Qc and Qd lowers the voltage at the input terminal of inverter 222 , causing indication signal Ind at a high voltage level and indication signal Indb at a low voltage level. In the opposite, it requires transistors Qc and Qd both turned off to have indication signal Ind at a low voltage level and indication signal Indb at a high voltage level.
[0019] Accordingly, when power is good ( i.e. power good signal PGD is at high voltage level), transistor Qd is turned off and signal Ind at a high/low voltage level will indicate that feedback signal FB has a voltage level higher/lower than the threshold voltage Vth of the first transistor Qc.
[0020] When output voltage V OUT of the power converter remains in a normal working range and power is good, the voltage level of the feedback signal FB is not lower than the threshold voltage Vth of transistor Qc, and thus transistor Qc remains on. However, if any error occurs to the power converter to raise the output voltage V OUT over a voltage limit and pull down the voltage level of feedback signal FB below the threshold voltage Vth of transistor Qc, transistor Qc is turned off, changing the logic state of indication signals Ind and Indb. Therefore, in this exemplary embodiment, the level transition of indication signal Ind from the high voltage level to the low voltage level could represent that the voltage level of the feedback signal FB is lower than the threshold voltage Vth.
[0021] Indication signal Ind and its inverse signal Indb (i.e., the output of the second inverter 224 ) are both transmitted to determining circuit 230 for error occurrence detection. In general, determining circuit 230 determines that the voltage level of output voltage Vout is over high and triggers an over voltage protection mechanism immediately when a level transition of indication signal Ind from a high voltage level to a low voltage level is detected. However, it should be noted that, in this exemplary embodiment, indication signal Ind also has another level transition from a high voltage level to a low voltage level when the power converter is just powered on. Please refer to FIG. 4 in conjunction with FIG. 3 . FIG. 4 is a diagram illustrating waveforms of the power-good signal PGD, the feedback signal FB, the indication signal Ind, an output signal Er_Q 1 of a flip flop 232 , and an error detecting signal Er_det which is an output signal of the determining circuit 230 .
[0022] As can be seen by referring to FIG. 3 and FIG. 4 , before time T 1 the system power is not supplied normally, the power-good signal PGD indicates the power is no good and forces the voltage level of the feedback signal FB to be low, such that transistor Qc is turned off, transistor Qd is turned on, and the voltage level at the drain of transistor Qd is pulled down to a low voltage level. As a result, the voltage level of the indication signal Ind is at a high voltage level. After the power-good signal PGD undergoes a transition from a logic low voltage level to a logic high voltage level, transistor Qc and transistor Qd are both turned off, and current source 221 pulls the voltage level at the drain of transistor Qd up to a high voltage level. As a result, the indication signal Ind lowers. This level transition of the indication signal Ind triggers flip flop 232 to make the output signal Er_Q 1 of flip flop 232 have a rising edge. At the same time, soon after the voltage level of the power-good signal PGD is pulled up, the voltage level of the feedback signal FB begins establishing and then rises over the threshold voltage Vth of transistor Qc at time T 2 . This turns on transistor Qc, pulls the voltage level at the drain of transistor Qc (i.e., the input voltage of the inverter 222 ) down to a low voltage level, and makes the indication signal Ind having a rising edge. In order to avoid making an erroneous judgment on the error occurrence at time T 1 , determining circuit 230 uses two T-type flip flops 232 and 234 cascaded in series to cope with the indication signal Ind.
[0023] At time T 1 , the indication signal Ind and the inverse indication signal Indb trigger flip flop 232 , while the error detecting signal Er_det at the output end of the comparing circuit 220 still remains at a zero potential. When the output voltage V OUT of the power converter gradually rises up to a normal voltage level (in an interval between T 3 and T 4 ), the voltage level of the feedback signal FB may be slightly decreased, but is not lower than the threshold voltage Vth of transistor Qc. Therefore, the indication signal Ind and the error detecting signal Er_det remain in their respective original states. An error is supposed to occur at time T 4 to indicate that the voltage level of the output voltage V OUT is boosted abnormally. At time T 4 , the voltage level of the feedback signal FB is decreased to a value close to a zero potential, which makes transistor Qc and transistor Qd both turned off. At this moment, indication signal Ind is induced to have a falling edge and flip flop 232 is triggered once more. Then, output signal Er_Q 1 of flip flop 232 undergoes a level transition from high to low, which triggers flip flop 234 to make the output signal Er_det of the flip flop 234 having a rising edge, as shown in FIG. 4 . That is, the determining circuit 230 determines that the current sensing resistor R CS may be grounded only when the indication signal Ind undergoes a level transition from a high voltage level to a low voltage level twice. In other words, the situation where the current sensing resistor R CS is grounded may be confirmed when the voltage level of the feedback signal FB is lower than the threshold voltage Vth of transistor Qc under the condition that the voltage level of the feedback signal FB has reached a steady state after the power converter is turned on.
[0024] The error detecting signal Er_det can inform the control chip to adjust the energy transfer of the transformer in the power converter to thereby decrease the output voltage V OUT into a safe working range, or signal a user of the power converter to instruct them to eliminate the error. Then the power-good signal PGD may be enabled again, and flip flops 232 and 234 may be reset. However, the use of the error detecting signal Er_det is not limited to indicate a failed current sensing resistor R CS , but could be for indicating other failure situations. The aforementioned implementation is for illustrative purposes only.
[0025] One skilled in the art will readily appreciate that the circuitry shown in FIG. 3 merely serves as one exemplary embodiment of the invention. Other circuit configurations which obey the spirit of the present invention can also achieve the characteristics and advantages of the invention. One skilled in the art can easily appreciate how to realize these alternative designs after reading the above paragraphs. Further description is omitted here for the sake of brevity.
[0026] In addition, the detecting apparatus 200 can be placed in a position external to the control chip, be integrated with the control chip, or be partially disposed outside of the control chip and partially integrated with the control chip. For instance, in one implementation, regulator 212 and photo coupler 214 are placed outside of the control chip and coupled to the output voltage V OUT , and power source 216 , impedance component R, comparing circuit 220 and determining circuit 230 are integrated with the control chip.
[0027] Briefly summarized, detecting apparatus 200 can rapidly and correctly detect occurrence of errors by detecting a feedback signal which has a certain relationship with the output voltage V OUT of the power converter. In addition, the structure of detecting apparatus 200 is simple and does not require extra pins to be added to the power converter, which can greatly save both area and production costs. As the voltage range associated with the enablement of the over voltage protection (i.e., the range of the voltage level of the feedback signal FB lower than the threshold voltage Vth of the first transistor Qc) is lower than the voltage level under a burst mode (usually 1.4V), the normal operation of the power converter is not affected. Please note that the detecting apparatus 200 is not limited to detecting errors caused by the current sensing resistor which is unwittingly grounded. Instead, any errors leading to an abnormal output voltage V OUT can be detected using the detecting apparatus 200 of the present invention.
[0028] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. | An apparatus is applicable to a power converter comprising a primary winding for receiving an input voltage and a secondary winding for generating an output voltage to power a load. The apparatus comprises a detecting circuit, a comparing circuit, and a determining circuit. The detecting circuit is configured to generate a feedback signal according to the output voltage. The comparing circuit is coupled to the detecting circuit and configured to compare the feedback signal and a threshold and accordingly generates an indication signal indicative of the over high output voltage. The determining circuit, which is in response to the indication signal, is configured to trigger an over voltage protection mechanism preventing the power converter from powering the load. Since the feedback signal is instantly responsive to the output voltage, the occurrence of an error can be rapidly and correctly detected, allowing rapid and correct protection for the power converter. | 7 |
COPYRIGHT RESERVATION
A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure as it appears in Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
The present invention relates to the field of pipe jacking. More specifically, the present invention relates to the controlled lubrication of the exterior of pipe jacked tunnel sections with a bentonite pumping system.
BACKGROUND OF THE INVENTION
Trenchless tunneling methods that create a tunnel by excavating of the tunnel while concurrently pressing or "jacking" a tunnel casing or liner into the newly excavated tunnel are well known. The methods of pipe jacking, auger boring and microtunneling all use a hydraulic ram for pushing a series of tunnel liner sections end to end into the tunnel forming a tunnel lining behind a tunneling excavation. The typical pipe jacking site includes a pit which is dug to a depth to which a pipe or a tunnel liner will be placed under a section of ground. A set of equipment used in the pit will include a hydraulic ram, a soil hauling device for removing a quantity of soil from the tunnel excavation face, a excavation device, a backstop for the ram to push against and sufficient space to lower a section of the tunnel liner into place. Outside the pit, a second set of support equipment will typically include a crane for lowering sections of pipe or tunnel liner and lifting excavated soil from the pit, digging equipment, and a set of various support equipment. The crew will include personnel working inside the pit and on the ground surface. The typical crew size is five persons in the pit, tunnel and above ground.
The tunnel excavation may be performed by a human using hand labor, a combination of human hand labor assisted by machine excavation, or a fully automated tunnel boring machine (TBM). By excavating and lining the tunnel concurrently, a tunnel cave-in or other dangers of the tunnel's unsupported faces are reduced. The tunnel excavation diameter is typically cut slightly larger than the tunnel liner sections to minimize compression of tunnel sections as they are pressed down the tunnels length.
Various tunnel liner cross section geometries have been used. Tunnel liner cross-sections have ranged from a rectangular shape to a circular shape. The tunnel liner section ends must match or link into the end of another similar tunnel liner section. A principal requirement of the tunnel liner section design is its capacity to withstand compressive stress from the hydraulic ram which presses the tunnel liner section into the tunnel. Each section after being pressed into the tunnel is then forced deeper into the tunnel by the next section inserted by the hydraulic ram. As each section is pressed by the ram, the previously inserted sections extend deeper into the tunnel forming the full tunnel liner.
As the tunnel liner receives more tunnel sections, the friction between each tunnel section's exterior surfaces and the surrounding soil structure accumulates. This accumulated friction forces the hydraulic ram to increase the amount of force required to press each additional tunnel section into the tunnel. The material strength of the tunnel section and an upper pressing limit of the hydraulic system "jacking" the tunnel sections limit the amount of force that can be applied to the tunnel sections. Thus, a method of reducing the friction is required to increase the length of the tunnel past these friction limitations. A method of lubricating the tunnel sections, is used that injects a slurry containing a composition called bentonite around tunnel sections as they are pressed into the tunnel at the hydraulic ram. Other methods also inject bentonite into the tunnel sections farther down the tunnel as the bentonite is lost or absorbed by the ground. Bentonite is a water and clay composition containing a potassium, calcium, or sodium montmorrillonite clay that exhibits thixotropic properties. A thixotropic property is a substance which is a liquid when agitated and returns to a gel state after agitation ceases. Industry calculations have estimated that lubrication of tunnel sections increases the length of tunnel sections that are insertable in a single tunnel by a thousand times based on the load attributable to friction. In industry studies, it is surmised that a gel layer which is formed by injecting sufficient thixotropic material around the exterior of the tunnel section will cause the tunnel sections to become "buoyant" and float on this gel layer as they are pressed into the tunnel. Experimental data indicates that this floating condition keeps the hydraulic forces required to press additional tunnels sections at roughly a constant value in loose soil and gravel below the water table.
Bentonite pumping is currently done in stages; the bentonite is mixed in a grout mixing unit, the bentonite is formed into a slurry or grout which is then transferred to a pumping station which is hand linked to orifices or hand operated valves that are located at an entrance or mouth of the tunnel or at several tunnel sections within the tunnel length. The valves are turned on by personnel in the tunnel if the tunnel is sufficiently large to admit a human. The preparation, pumping and distribution of the bentonite is largely dispersed and separate from the tunneling operation and requires additional personnel to operate and maintain the lubrication of the tunnel sections. Some integration has occurred by combining the mixing and pumping of the bentonite in the Akkerman bentonite pump model EH-2250. The EH-2250 eliminates the separate above ground mixing and pumping units and delivers a consistent and uniform bentonite slurry to the delivery point. The other aspects of bentonite delivery still require separate manpower intensive operations and require a crew member on a pipe jacking crew to implement bentonite pumping. The crew member has tasks of filling the mixing reservoirs with water and dry bentonite, operating the mixers, operation of the distribution pumping system and operation of tunnel valves. Once the tunnel is finished, a worker must to enter the tunnel to remove the conduit from the tunnel liner and to plug the holes that the bentonite was pumped through. This bentonite lubrication technique is limited to human sized tunnels.
Therefore, there is a need to provide bentonite lubrication in a trenchless tunneling operation that reduces manpower requirements and is a safe and efficient manner and mode of bentonite distribution over the current methods. There is also a need to provide selectively dispensed bentonite in tunnels which are too small for human entry
SUMMARY OF THE INVENTION
An apparatus and method for selectively injecting a liquid bentonite slurry around an exterior of a tunnel liner segment which is pressed into a tunnel being concurrently excavated during a pipe jacking installation. The bentonite slurry lubricates the exterior of the tunnel liner reducing the force required to press the tunnel liner into the tunnel. The apparatus allows an operator of the pipe jacking operation to selectively inject bentonite around individual tunnel liner segment or to allow the apparatus to selectively inject bentonite as required by a preset injection pressure threshold value.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a cross section view of the present invention used in a typical pipe jacking operation;
FIG. 2 is a system diagram schematic of the present invention;
FIG. 3 is an isometric view of a display unit of the present invention;
FIG. 4 is a cross section view of an embodiment of a pumping unit of the present invention;
FIG. 5 is a detail of an embodiment of the present invention showing a tunnel valve installation;
FIG. 6 is a cross section view of a typical pipe jacking operation using a wireless tunnel valve embodiment of the present invention;
FIG. 7 is a detail of an embodiment of the present invention using a pressure sensing tunnel valve installation; and
FIG. 8 is a detail of an embodiment of the present invention showing a self releasing tunnel valve.
DETAILED DESCRIPTION OF THE INVENTION
In FIGS. 1,2 a bentonite pumping system is shown, indicated generally at 100, for pumping a quantity of bentonite slurry 102 around a tunnel liner 104 being pressed into a concurrently excavated tunnel 106. System 100 includes a pumping unit 108, mounting at least a single bentonite tank 110, a mixer motor 112, connected to a mixer mechanism 114 located inside the bentonite tank 110. Bentonite tank 110 includes a water input valve 116, a return line valve 118, a suction valve 120, an opening for the addition of dry bentonite powder 121 and a tank level sensor 122. The suction valve 120 is connected to a distribution pump 124 that is driven by a pump motor 126. The distribution pump 124 is connected to the return line valve 118 and an output valve 128. The output valve 128 is connected to a conduit 130 to a tunnel valve 132. A flow meter 133 on the conduit 130 monitors the amount of bentonite slurry 102 being pumped to the tunnel valve 132 in the tunnel 106.
System 100 includes a remote operation capability that includes a display unit 134 connecting via a control line 107 to a programmable controller (PLC) 136 in the pump unit 108. Display unit 134 displays specific status parameters of system 100 to a system operator (not shown.) Display unit 134 has a display screen 138 and a keypad 140 enclosed in a display housing 142. Display unit 134 also directs PLC 136 to control the speed of pump motor 126 via a variable frequency motor controller 154. The display unit 134 also directs the PLC 136 to control the mixer motor 112 and valves 116,118,120,128 by selecting bentonite slurry 102 mixing, recirculating or dispensing modes of operation for the pump unit 108.
In FIG. 3, the operator display unit 134 has an alphanumeric display screen 138 including at least a set of two alphanumeric display lines. The display unit 134 informs the operator of the status conditions of the bentonite pumping system 100. The operator is given warnings and override options in a series of visual displays on the screen 138 if the PLC 136 detects a anomalous condition in the system 100. Examples of display screen 138 may include commercially available displays using liquid crystal displays, light emitting diode displays or other appropriate display formats. Keypad 140 includes a set of function keys 144, a set of cursor keys 146 and a set of numeric keys 148. Function keys 144 allow the operator to select and control a series of bentonite pumping system 100 parameters by selecting one of the function keys 144. Operator controls individual tunnel valves 132 with a set of individual switches 149 that activate the tunnel valves 132 via a set of signal control lines 150 to inject bentonite slurry 102 through the tunnel liner 104. The display unit 134 also has an emergency shutdown switch 151 to shutdown the whole system 100 should the need arise. The bentonite pumping system 100 has several functions available to the operator for control including, individual control of the tunnel valves 132, individual control of the mixing mechanisms 114, proportional control of the distribution pump 124 speed which controls the flow rate of the bentonite slurry 102, modal control of tank valves 118,120,128 by way of selecting mixing and pumping modes for the dual tanks 110. System 100 allows the operator to monitor parameters including all positions(open/closed) for each valve 116,118,120,128 in the bentonite pumping unit 108, the amount of bentonite slurry 102 pumped to the tunnel valves 132 during a desired period, and the level of bentonite slurry 102 present in either of the tanks 110. The level sensor 122 is polled by the PLC 136 on a periodic basis to alert the operator of low bentonite slurry 102 levels in tank 110 and to protect pump 124.
PLC 136 controls the system 100 devices based on a series of programs inherent to the PLC 136 and command inputs from the display unit 134. PLC 136 is a digitally operating electronic apparatus that uses a programmable memory for storing an internal set of instructions that implement a specific set of output functions. An example of a PLC 136 representative of the type of PLC 136 used in the present invention is a Mitsubishi Model FX-48MR-UA1/UL with analog input and output blocks. The present invention's PLC 136 continuously monitors and receives digital and analog input signals from system 100 devices that are connected to the PLC 136 as inputs. Inputs include status of valves 116,118,120, 128,132, the level status of tank 110 from level sensor 122, motor status from motors 112, 126, flow rate of bentonite slurry 102 from flow meter 133 and commands from display unit 134. Following the set of instructions in memory, the PLC 136 controls the status of the system 100 devices which are connected to the PLC 136 as outputs. Outputs include actuation of valves 116,118,120,128, control of motors 112,126, the reset command for flow meter 133 and acknowledgment of commands from display unit 134. PLC 136 has a digital to analog conversion interface 160 for controlling the status of devices requiring an analog control signal and an analog to digital conversion interface 162 for interpreting an analog signal from system 100 devices that the PLC 136 monitors.
In FIG. 4, another embodiment of the pump unit 108 holds a dual bentonite tank 110 vertically disposed with the mixer mechanism 114 suspended into the tank 110 with the mixer motor 112 mounted on the bentonite tank 110. Each tank 110 has identical equipment to the single tank 110 configuration shown in FIG. 1 with the exception that the dual tanks 110 share the distribution pump 124. The tanks 110 are interconnected to allow either of the return line valves 118 to receive the contents of either tank 110 from the distribution pump 124. This embodiment of the present invention has an additional mode of operation of allowing pumping of bentonite slurry 102 between tanks 110. The use of dual tanks 110 allows one tank 110 to mix new bentonite slurry 102 while the other tank 110 is used to delivery ready bentonite slurry 102 to the tunnel valves 132. The dual tanks 110 allows the steady and continuous delivery of bentonite slurry 102. Bentonite slurry 102 is removed from either tank 110 through each tank's 110 suction valve 120. The suction valve 120 is an electrical step motor driven ball valve. An example of a ball valve of this type would be the Apollo 71-148-01/EVA-40. Once the suction valve 120 is open, the distribution pump 124 is activated by the PLC 136 to draw bentonite slurry 102 from the tank 110. Depending on whether the display unit 134 requests recirculation or tunnel pumping, the PLC 136 will either open either return line valves 118 or the output valve 128 which are also electrical step motor driven ball valves similar to the type used by the suction valve 120. If the return valves 118 are open, then the pump unit 108 is in a recirculation mode of operation. If only one return valve 118 is open, then the pump unit 108 is transferring bentonite slurry 102. If the outlet valve 128 is open, the distribution pump 124 is pumping bentonite slurry 102 to the tunnel 106. The distribution pump 124 is a screw type pump 124 that is driven by a variable speed motor 126. An example of this style of pump 124 is the Moyno L6 pump. The variable frequency motor controller 154 allows the distribution pump 124 to pump bentonite slurry 102 at varying rates. The flow meter 133 measures the flow rate of bentonite slurry 102 flowing through the conduit 130. The flow meter 133 information is displayed on the display unit 134 and is used by the operator to control the distribution pump 124 output rate.
In FIG. 5, the conduit 130 carrying bentonite slurry 102 mounts to the tunnel valves 132 of an electrical step motor driven ball valve similar to the type used in the suction valve 120. The tunnel valve 132 has two positions, an open or closed position which are commanded in this embodiment by the operator. The tunnel valve 132 is disposed on a upper internal surface 164 of the tunnel liner 104 segment. The bentonite slurry 102 is transported to the tunnel valve 132 through conduit 130. The tunnel valve 132 is attached to the conduit 130 by a tee connection 131 and a flexible conduit 133. The bentonite slurry 102 passes through the open tunnel valve 132 into a second flexible conduit 135 to a sleeve 137 that passes through the tunnel liner 104 wall. The bentonite slurry 102 is deposited between an exterior surface 182 of tunnel liner 104 and the tunnel wall 106. The tunnel valve 132 connected to the display unit 134 via the control line 150. The sleeve 137 provides a connection point for the conduit 135 and must be closed off after the tunnel 106 is finished and the bentonite system 100 is removed.
FIG. 6 is a cross-sectional view of the tunneling operation utilizing a set of wireless telemetry transmitters 168 to send and receive a set of valve position actuation commands and feedback signals to a base station 169. Examples of the transmitter 168 include a wireless, infrared, radio or other suitable non-wired transmissions that receive and transmit the control commands and signal responses to the base station 169 which in turn transmits to the PLC 136 or the display unit 134. Transmitter 168 on each tunnel valve 132 may be individually or group addressable by the PLC 136. The telemetry transmitter 168 increases the system 100 reliability by eliminating the need to string individual control lines 150 to each tunnel valve 132 from the display unit 134. This embodiment of bentonite pumping system 100 shows the use of a single power feed in control line 150 that connects in parallel to each tunnel valve 132. The single power feed 150 does not carry any control signals.
FIG. 7 is an embodiment of the bentonite pumping system 100 that uses a pressure sensor 188 located coincident to the sleeve 137. The pressure sensor 188 is located in a manner to sense the pumping pressure required to inject bentonite slurry 102 through the sleeve 137 between exterior 182 and the tunnel 106. Examples of pressure sensors configurations may include semiconductor, diaphragm, strain gage or other forms of pressure sensors that are appropriate for the bentonite pumping system 100 environment. The sensed pressure is then fed to a valve controller 172 which will adjust and actuate the tunnel valve 132 based on the sensed pressure. The valve controller 172 may be a programmable logic controller similar to the PLC 136, but limited in power and scope of functionality. The valve controller 172 will open the tunnel valve 132 when the sensed pressure of the bentonite slurry 102 is below a value set by the system operator. The tunnel valve 132 will also self-close if the injected bentonite slurry 102 sensed pressure is above a value set by the system operator. This embodiment is a full automation of the bentonite pumping process and has the advantage of maintaining a constant supply of bentonite slurry 102 based on pressure at each sleeve 137 location in the tunnel liner 104. The bentonite pumping system 100 also has a capacity to alert the operator of likely sites where an inordinate amount of bentonite slurry 102 is being pumped out of a single or series of tunnel valves 132. This will allow the operator to react to a possible problem by cutting off the bentonite slurry 102 flow to the affected tunnel valves 132 or to boost the pumping rate of the pump 124 to compensate for the lost bentonite slurry 102. This embodiment of the present invention will allow correlation of changes in the bentonite slurry 102 pressure to be matched against a set of soil or ground types that are encountered at throughout the tunnel 106 excavation.
In FIG. 8, shows an embodiment of a tunnel valve 132 used in microtunneling operations where the tunnel liner 104 is smaller than human sized. In the present invention, sleeve 137 includes a check valve 190 that only allows the flow of bentonite slurry 102 into and around the exterior 182 of the tunnel liner 104 segment from the tunnel valve 132. The check valve 190 construction included a ball 192 that reseats into a socket 194 when the pumping pressure of the bentonite slurry 102 drops below a set pressure sealing off the sleeve 137. Once the pumping operation is completed, a self releasing connector 196 between the sleeve 137 and the second flexible conduit 135 will disconnect upon operator command from the tunnel liner 104 when the tunnel 106 is completed. Examples of self releasing connector 196 include a solenoid compressed detente release, an electromagnetically interlocked collar, a pilot operated hydraulic collar, an electrically interlocked collar or other suitable remotely actuated devices. By allowing the retrieval of nearly all of the components of the bentonite pumping system 100, the self releasing connector 196 make bentonite pumping in the smaller diameter tunnels 106 practical and feasible. Connector 196 allows the remote or automated bentonite pumping and lubrication of tunnel liner 104 diameters as small as eighteen inches.
The method of bentonite lubrication in a pipe jacking operation is shown in FIG. 1. The bentonite slurry 102 is mixed in the tank 110 from a quantity of dry bentonite powder (not shown) input by a crew member (not shown) and a quantity of water (not shown) input by the water input valve 116. The mixing is performed by mixer mechanism 114 which keeps the bentonite slurry 102 in a liquid state by constant agitation. The bentonite slurry 102 is pumped out of the tank 110 by the distribution pump 124 to the conduit 150. Bentonite slurry 102 is pumped through the conduit 150 to tunnel valve 132 that is placed in a tunnel liner 104 segment. In a pipe jacked tunnel 106, tunnel liner 104 segments are pushed one segment at a time into a concurrently excavated tunnel 106 by a hydraulic ram 176, each tunnel liner 104 segment back end 178 to the next tunnel liner 104 segment front end 180. Tunnel valve 132 output extending through tunnel liner 104 segment wall to an exterior surface 182. Bentonite slurry 102 is pumped out through tunnel valve 132 to the tunnel liner exterior 182. Bentonite slurry 102 flows around and lubricates the tunnel liner exterior 182 decreasing surface friction between earth tunnel 106 and the exterior surface 182 of the tunnel liner 104 segment. As the tunnel liner 104 is pushed farther into the tunnel 106, the bentonite slurry 102 is expended or lost and must be replaced. Tunnel valves 132 are distributed along the tunnel 106 to supply bentonite slurry 102 to the length of the tunnel 106. The bentonite pumping system operator (not shown) is located in a tunneling pit 184 that contains a hydraulic ram 176. The display unit 134 used by the operator is connected to the rest of the bentonite pumping system 100 outside the pit 184 with control line 107.
The present invention describes a bentonite pumping system 100 that is configurable in both a remote control and in an automated control mode. The remote control mode is an open loop control solution that relies on the skill and expertise of the operator utilizing the bentonite pumping system 100 to gauge the amount and pressure of bentonite slurry 102 pumped into the tunnel 106. The remote method eliminate the task of bentonite mixing and reduces the number of operators in a pipe jacking crew by one. The operator is able to coordinate the jacking and the bentonite pumping to improve the quality and quantity of lubrication available for jacking each section of tunnel liner. The automated control system closes the control loop by sensing the feedback pressure at the sleeve 137 and providing a constant pressure flow of bentonite slurry 102 through out the length of the tunnel liner 104. The automated system 100 eliminates the need for any operator with the exception of replacing the bentonite slurry 102 in the mixing tanks 110 as the supply runs low.
The manner and content of the present invention disclosed herein is described with reference to preferred embodiments. Workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. | An apparatus and method for selectively injecting a liquid bentonite slurry around an exterior of a tunnel liner segment which is pressed into a tunnel being concurrently excavated during a pipe jacking installation. The bentonite slurry lubricates the exterior of the tunnel liner reducing the force required to press the tunnel liner into the tunnel. The apparatus allows an operator of the pipe jacking operation to selectively inject bentonite around individual tunnel liner segment or to allow the apparatus to selectively inject bentonite as required by a preset injection pressure threshold value. | 4 |
RELATED APPLICATIONS
[0001] This application is a continuation of copending patent application Ser. No. 10/255,131, filed Sep. 25, 2002, and titled DUAL MOTORCYCLE EXHAUST SYSTEM, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/326,026, entitled TRUE DUAL MOTORCYCLE EXHAUST SYSTEM, filed Sep. 26, 2001, the disclosures of which are hereby incorporated by reference in their entireties.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to exhaust systems. More particularly, the invention relates to an exhaust system for a multi-cylinder internal combustion engine.
[0004] 2. Background
[0005] Motorcycles commonly employ exhaust systems to convey the exhaust gas from the engine's cylinder to the ambient environment. The journey begins at the engine cylinder, which incorporates intake and exhaust ports for ingress and egress to the cylinder. Fresh air mixed with fuel enters the engine cylinder through the intake port where it is subsequently compressed by a piston and ignited. A rapid expansion of the compressed fuel and air occurs, thereby forcefully moving the piston in the opposite direction to the compression stroke. Once the expansion is complete, the exhaust port opens to allow the combustion by-products or gas to exit the engine cylinder and enter an exhaust pipe. The exhaust port may be a passageway into the engine cylinder that is uncovered by the retreating piston, as in a two-stroke design well known in the art. In the case of a four-stroke design, a valve is utilized to open or close the exhaust port. The exhaust gas expelled from the engine cylinder, after passing through the exhaust port, enters an exhaust pipe. The exhaust pipe is designed to direct the exhaust gas towards the rear of the motorcycle and commonly utilizes bends and curves to accomplish this goal.
[0006] In the case of a V-Twin Harley-Davidson® motorcycle engine, the design of the stock OEM exhaust system affects the motorcycle's performance. The OEM exhaust system comprises a partial dual exhaust system with unequal length exhaust pipes from each cylinder. This system allows some communication between the exhaust gases from the cylinders via a crossover pipe. However, the design of this crossover pipe is detrimental to the engine's performance. The exhaust gases from the cylinders interfere with each other as they are routed to two exhaust mufflers. Moreover, the routing path of the gases from the engine exhaust ports to the exhaust mufflers increases the exhaust systems backpressure.
[0007] The design of the stock OEM exhaust system for the V-Twin Harley-Davidson® motorcycle also affects the aural sensation experienced by the rider. For example, the sound of the OEM exhaust system is uneven as heard by the rider due to the exhaust system's design. Further, during the engine's transition from under load to a state of deceleration, the engine emits a staccato popping sound that is not pleasing to the ear. Any potential aftermarket fix for these performance and aural sensation issues is further complicated by the design of the Harley-Davidson® OEM exhaust system which attaches to the chassis of the motorcycle at fixed points, thus impeding any modifications to the exhaust system without permanent changes to the motorcycle.
SUMMARY OF THE INVENTION
[0008] One embodiment of the present invention is an exhaust system for a V-Twin motorcycle engine. This embodiments provides a substantial improvement to the well-known Harley-Davidson® engine.
[0009] One aspect of the aftermarket exhaust system constructed in accordance with one embodiment of the present invention is an exhaust system which comprises a first exhaust port in communication with a first cylinder of the engine to discharge a first pulse of exhaust gas, a second exhaust port in communication with a second cylinder of the engine to discharge a second pulse of exhaust gas, wherein the first and second exhaust ports are both located on a first side of the V-Twin engine. The system further comprises a first exhaust pipe having an inlet end and an outlet end, wherein the inlet end is connected to the first exhaust port for scavenging and routing the first pulse of exhaust gas along the first side and in a direction aft of the motorcycle chassis, a second exhaust pipe having an inlet end and an outlet end, wherein the inlet end is connected to the second exhaust port for scavenge and routing the second pulse of exhaust gas through the motorcycle chassis and along a second side of the V-Twin engine in a direction aft of the motorcycle chassis, wherein the first and second sides are substantially parallel with the motorcycle chassis, and wherein the second exhaust pipe utilizes an OEM attachment point to the motorcycle chassis. The system still further comprises a first muffler connected to and in flow communication with the first exhaust pipe, wherein the first pulse of exhaust gas is expelled through the first muffler to the atmosphere, and a second muffler connected to and in flow communication with the second exhaust pipe, wherein the second pulse of exhaust gas is expelled through the second muffler to the atmosphere.
[0010] Another aspect of the present invention is a motorcycle with a two cylinder V-Twin engine and a true dual exhaust system wherein the true dual exhaust system individually routes exhaust gases from the two cylinders to a pair of mufflers.
[0011] Still another aspect of the present invention is a motorcycle that comprises a frame, a V-twin engine attached to the frame and having a first and a second cylinder head, each containing a cylinder, wherein the first and second cylinder heads exhaust gas on a same side of the V-twin engine, and a dual exhaust system in flow communication with the two cylinder heads and configured to route exhaust gases from the two cylinders, to different sides of the frame, and to the atmosphere.
[0012] Yet another aspect of the present invention is an exhaust system component for a Harley-Davidson® motorcycle with a V-Twin engine, wherein the V-twin engine comprises first and second exhaust ports, both located on a first side of the V-twin engine, and wherein the second exhaust port is located rearward of the first exhaust port. The exhaust system component comprises an exhaust pipe having an inlet end and an outlet end, wherein the inlet end is configured to route exhaust gases from the second exhaust port and through the motorcycle and along a second side of the V-Twin engine in a direction rearward of the motorcycle, wherein the first and second sides are substantially parallel with the motorcycle, and wherein the exhaust pipe utilizes an OEM attachment point to the motorcycle.
[0013] Still another aspect of the present invention is a method of processing exhaust gases from a V-Twin engine in a motorcycle, wherein a first pulse of exhaust gas is produced in a first cylinder of the V-Twin engine and a second pulse of exhaust gas is produced in a second cylinder of the V-Twin engine. The method comprises routing the first pulse of exhaust gas from the first cylinder and along a first side of the V-Twin engine, wherein the first cylinder exhausts the first pulse of gas on the first side of the V-Twin engine, and routing the second pulse of exhaust gas from the second cylinder and along the first side of the V-Twin engine and back under a seat of the motorcycle to a second side of the V-Twin engine, wherein the second cylinder exhausts the second pulse of gas on the first side of the V-Twin engine, and wherein the first pulse of exhaust gas and the second pulse of exhaust gas follow different flow paths.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The features, objectives, and advantages of the embodiments of the invention will become more apparent from the detailed description set forth below when taken in conjunction with the drawings wherein like parts are identified with like reference numerals throughout, and wherein:
[0015] FIG. 1 is a top plan view showing an exhaust system according to one embodiment of the invention.
[0016] FIG. 2 is a side perspective view of an upstream pipe shown in FIG. 1 in accordance with one embodiment of the invention.
[0017] FIG. 3 is a top plan view showing a Harley-Davidson® OEM exhaust system.
[0018] FIG. 4 is a side perspective view of a Harley-Davidson® motorcycle incorporating the upstream pipe into its OEM exhaust system.
[0019] FIG. 5 is a side perspective view of a portion of the motorcycle exhaust system encompassed within line 5 of FIG. 4 and shows the upstream pipe of the present invention connected to a cylinder.
[0020] FIG. 6 is a side perspective view of the upstream pipe from FIG. 2 , taken on the opposite side of the motorcycle to that of FIG. 4 .
[0021] FIG. 7 is a front perspective view of the upstream pipe shown in FIG. 2 as installed on the motorcycle of FIG. 4 .
[0022] FIG. 8 is a rear perspective view of the upstream pipe shown in FIG. 2 as installed on the motorcycle of FIG. 4 .
DETAILED DESCRIPTION OF THE INVENTION
[0023] In a single cylinder engine, the exhaust gas, after passing through the exhaust pipe, is typically fed into a muffler prior to its expulsion into the atmosphere to dissipate unwanted noise originating in the combustion process. The exhaust system may also include a catalytic converter or other exhaust treatment device well known in the art. The muffler design will significantly affect the audible noise level or sound of the engine. A manufacturer can attenuate or change the sound of the engine so as to not only meet governmental noise requirements but also for the engine to exhibit a pleasing sound to the ear.
[0024] Depending on the design of the exhaust system, including the muffler and exhaust pipe, back pressure will be introduced into the exhaust system. Back pressure impedes the free flow of exhaust gases along the exhaust system's entire length. For example, in a four-stroke engine the piston pushes the exhaust gases out of the cylinder and into the exhaust system. If the back pressure in the exhaust system is reduced, the piston requires less force to expel the exhaust gases from the engine cylinder thereby increasing the performance and efficiency of the engine.
[0025] The performance of an engine is measured by the engine's generation of, for example, horsepower and torque. These two values can be measured over the entire RPM operating range as well as their peak values. Generally, less back pressure will enhance the performance of the engine by increasing the engine's efficiency. This rise in efficiency can further reduce the engine's fuel consumption. However, a significant reduction in back pressure, which may be accomplished by, for example, using short exhaust pipes and no muffler, may have an adverse effect on engine noise and overall performance. An exhaust system design that maximizes the horsepower of an engine will often have a deleterious effect on the engine's torque production over a portion of the RPM range. If this drop in torque is located in the middle of the RPM range, it may be noticeable as a momentary drop in acceleration to the rider or driver and be undesirable.
[0026] The overall length and shape of the exhaust system is an important factor in determining how the engine will operate and affects the performance of the engine. For example, with a multi-cylinder engine the routing of the individual exhaust systems for each cylinder will affect flow turbulence. Flow turbulence can be caused by pulses of exhaust gas from the different cylinders combining before being expelled to the atmosphere.
[0027] Moreover, the geometry of the exhaust ports by which the exhaust is expelled form the engine cylinders, may also hamper the design of the exhaust system. Furthermore, the design of an exhaust system is also affected by cost, size, weight, and packaging limitations. This concern is especially acute for a motorcycle since the exhaust system needs to fit close to the motorcycle frame so that the rider and passenger can straddle the motorcycle and not be subjected to burns or the like caused by contact with the hot exhaust system. An automobile is less prone to the concern for unwanted contact with the exhaust system as the car's floorpan is a barrier between the exhaust system and the occupants. A motorcycle, in a similar fashion, can incorporate heat shields to cover the exhaust system to further protect the rider/passenger from the hot exhaust system. This heat shield may also act as a sound barrier to reduce the noise associated with the exhaust system. For an automobile, the length of the exhaust system may be increased to help dampen out the engine noise originating in the combustion process, but this may not be well suited for a motorcycle due to a motorcycle's relatively short length as compared to an automobile.
[0028] Exhaust systems are commonly routed along the sides or below the motorcycle depending on such design factors as, for example, the orientation of the engine cylinders with respect to one another, the orientation of the engine in the motorcycle frame, the preferred riding characteristics, aesthetics, the size of the motorcycle, and the location of the motorcycle's center of gravity. A motorcycle with a transverse engine to its frame may be able to route its exhaust system below the engine and frame without increasing the overall width of the motorcycle. The cylinders of a transverse engine are often located at similar distances from the mufflers, which simplifies designing an equal length exhaust system.
[0029] A motorcycle with an engine inline with the frame, for example, an inline “V” configuration, may be able to route its exhaust system along both sides of the motorcycle due to its narrower width. However, in such an arrangement, the engine cylinders will not be located at similar distances from the mufflers. This configuration causes some of the exhaust gases to travel a longer distance prior to being expelled to the atmosphere. The location of each exhaust port around the circumference of its associated cylinder may also increase the difficulty in designing an exhaust system for an inline engine.
[0030] As a result of the many tradeoffs associated with the design of an exhaust system, a manufacturer will choose an exhaust system that presents a compromise between these characteristics for the consumer. As discussed above, these characteristics may include, for example, cost, size, weight, engine noise, aesthetics, performance, and packaging limitations.
[0031] Customization of exhaust components by motorcycle riders, such as exhaust pipes and mufflers, is common in the aftermarket. Customization allows the owner to re-optimize the characteristics of their vehicle so as to maximize their own satisfaction. A successful customization leads to not only personal satisfaction of accomplishment, but also a feeling of attachment to the vehicle. Often, the replacement of a component made by the original equipment manufacturer (OEM) with an aftermarket part does not live up to expectations and will not be easily reversible once it is completed. This can lead to the owner incurring additional costs to reverse the modification. For example, the addition of a force air induction system to an automobile often requires the cutting of a hole in the hood over an engine. If the owner decided the additional noise outweighed the performance increase, the purchase of a new hood would have to be absorbed to reverse the modification. In the case of exhaust systems, incorporation of aftermarket components often requires cutting and welding of the OEM exhaust system. Exhaust pipes or other parts of the exhaust system are often cut with subsequent welding being performed to incorporate the aftermarket component. Thus, the level of financial risk being taken by the owner and difficulty in reversing the modification are increased.
[0032] One significant feature of embodiments of this invention is that it provides the benefits of using a true dual exhaust system while minimizing cost, weight and packaging issues associated with such a system. The exhaust system allows the pulses of exhaust gas from different cylinders to be individually routed through the exhaust system. By individually routing the exhaust systems, the inherent drawbacks of combining pulses of exhaust gases are avoided. Combining the pulses of exhaust gas incorrectly from multiple cylinders can lead to an increase in back pressure and a corresponding drop in engine performance. In the present invention, the separation of the pulses of exhaust gas from multiple cylinders increases the performance of the engine by enhancing scavenging. As a result, exhaust systems constructed in accordance with this invention actually increase the exit velocity of the exhaust gas from the engine cylinder.
[0033] Another feature of the invention is that each cylinder has substantially its own equal length exhaust pipe. This means each exhaust pipe is routed between the exhaust port and the mufflers such that all of the exhaust pipes have the same overall length. The length of the exhaust pipe affects the performance of the cylinder from which the exhaust pipe receives the pulses of exhaust gas. Using equal length exhaust pipes for each cylinder of a multi-cylinder engine allows all of the cylinders of a multi-engine to be uniformly optimized.
[0034] Still another feature of the invention is that it emits a strong, throaty rumble typically preferred by riders of touring bikes, yet not so loud as to cause undue rider fatigue on a long road trip. In contrast, the OEM exhaust system for the Harley-Davidson® results in an uneven sound coming from the two mufflers. Moreover, the OEM exhaust system exhibits an unpleasant popping sound during deceleration which is not present when the exhaust system according to the embodiments disclosed herein is employed.
[0035] FIG. 1 is a top plan view showing an exhaust system according to one embodiment of the invention. An internal combustion engine 20 has two cylinders 22 , 24 arranged in-line. Each of the two cylinders 22 , 24 have fixedly attached a cylinder head 26 , 28 which forms two combustion chambers (not shown). Each cylinder head 26 , 28 incorporates an intake port (not shown) and an exhaust port 30 , 32 for ingress and egress to the each cylinder 22 , 24 . The intake ports are connected to an intake system (not shown) located between the cylinders 22 , 24 . The intake system mixes fresh air with fuel before they enter the engine cylinders 22 , 24 . The mixed air and fuel is subsequently compressed by a piston (not shown) into each of the combustion chambers and ignited. A rapid expansion of the compressed fuel and air occurs, thereby forcefully moving the piston in the opposite direction to the compression stroke. The exhaust ports 30 , 32 are located on the same side with respect to a centerline 33 through engine 20 .
[0036] The ignition of the compressed fuel and air occurs in an alternating sequence whereby one of the cylinders 22 , 24 transmits a pulse of exhaust gas followed by the transmission of another pulse of exhaust gas from the other cylinder 22 , 24 . In the embodiment shown in FIG. 1 , this sequence continually repeats during the operation of the internal combustion engine 20 . Once the rapid expansion of the compressed fuel and air is complete, the exhaust port 30 , 32 which is in flow communication with the ignited engine cylinder 22 , 24 opens to allow the combustion by-products or pulse of gas to exit. The exiting pulse of exhaust gas travels from the cylinder head 26 , 28 and into a first or a second exhaust pipe 34 , 36 . As illustrated in FIG. 1 , the first exhaust pipe 34 receives pulses of exhaust gas from the first cylinder 22 . Similarly, the second exhaust pipe 36 receives pulses of exhaust gas from the second cylinder 24 .
[0037] The first exhaust pipe 34 has an inlet end and an outlet end. The inlet end is connected to the exhaust port 30 to scavenge each pulse of exhaust gas from engine cylinder 22 . The first exhaust pipe 34 is configured to route the scavenged pulse of exhaust gas away from the engine 20 and towards its outlet end. The outlet end is in flow communication with a first muffler 38 . The first muffler 38 is configured to exhaust the pulse of exhaust gas received from the first exhaust pipe 34 into the atmosphere.
[0038] The second exhaust pipe 36 has an inlet end and an outlet end. The inlet end is connected to the exhaust port 32 to scavenge each pulse of exhaust gas from engine cylinder 24 . The second exhaust pipe 36 is configured to route the scavenged pulse of exhaust gas away from the engine 20 and towards its outlet end. The outlet end is in flow communication with a second muffler 40 . The second muffler 40 is configured to exhaust the pulse of exhaust gas received from the second exhaust pipe 36 into the atmosphere.
[0039] The first and second exhaust pipes 34 , 36 are approximately of equal length. This means each pulse of exhaust gas expelled from the engine 20 travels approximately the same distance prior to being expelled to the atmosphere. The benefit to using equal length first and second exhaust pipes is that the pulses of exhaust gas will not arrive at the same time at each of the mufflers 38 , 40 , which minimizes any aural interference between the pulses. In one embodiment, the length of the first exhaust pipe 34 is within 10% of the length of the second exhaust pipe 36 .
[0040] The use of approximately equal length first and second exhaust pipes, as compared to an exhaust system that use unequal length exhaust pipes, increases the performance of the internal combustion engine 20 by enhancing scavenging. Scavenging is the process of removing the exhaust gases from the cylinders. Scavenging may be enhanced or reduced depending on the design of the exhaust system coupled with the design of the internal combustion engine 20 . For example, the design of an internal combustion engine along with the engine's performance goals will dictate the optimal length of its exhaust system. For example, an engine designed to maximize torque may require a longer exhaust system than the same engine if optimized for maximum horsepower. The likely operating range of the engine will also affect the selection of the length of the exhaust system. Moreover, the incorrect combining of pulses of exhaust gases from different cylinders due to exhaust length variations may lead to an increase in back pressure and a corresponding drop in engine performance.
[0041] In signal cylinder engines, the routing of the exhaust system to maximize scavenging is simplified as compared to routing for multi-cylinder applications. Often, the exhaust ports for the multi-cylinder engine are located at varying distances from the exhaust mufflers. In such a situation, the length of the exhaust system does not optimize the desired engine characteristic for all of the cylinders of the engine. To maximize the desired characteristic for all of the cylinders of the engine, the pulses of exhaust gas should travel a similar distance prior to their expulsion into the environment. A properly scavenged engine will actually increase the exit velocity of the pulse of exhaust gas from the cylinders 22 , 24 .
[0042] Each pulse of exhaust gas that is exited to the atmosphere forms a low-pressure zone (not shown) in its wake. This low-pressure zone preferentially travels back up the exhaust system towards the exhaust port to scavenge a subsequent pulse of exhaust gas. In a four-stroke engine, this reduces the force required by the piston to expel the pulse of exhaust gas from the plurality of cylinders 22 , 24 . For example, the use of equal length first and second exhaust pipes 34 , 36 improves engine scavenging whereby the performance of the engine is improved.
[0043] Still referring to FIG. 1 , the second exhaust pipe 36 comprises an upstream pipe 42 and a downstream pipe 44 . The upstream pipe 42 is in communication with the second exhaust port 32 and routes the pulse of exhaust gas from a first side of the engine 20 and across the centerline 33 towards a second side. As shown in FIG. 1 , the upstream pipe 42 is in flow communication with the downstream pipe 44 . The downstream pipe 44 further routes the pulse of exhaust gas to the second muffler 40 . The width of the downstream pipe 44 , measured in a direction that is perpendicular to centerline 33 , can range between 7.185 and 8.185 inches. In the embodiment illustrated in FIG. 1 , the width is 7.685 inches.
[0044] The operation of the upstream pipe 42 may be understood upon reference to FIG. 2 , which is a side perspective view of the upstream pipe 42 in accordance with the invention. The upstream pipe 42 comprises a first elbow 46 in flow communication with the exhaust port 32 . The first elbow 46 routes the pulse of exhaust gas away from the exhaust port 32 . The first elbow 46 has substantially a 2″ radius of curvature for less than a 90-degree arc. In one embodiment, the arc length ranges between 65 and 75 degrees. In the embodiment illustrated in FIG. 2 , the arc length is 70 degrees.
[0045] The first elbow 46 is in flow communication with a second elbow 48 . The second elbow 48 routes the pulse of exhaust gas received from the first elbow 46 through at least a 180 degree turn towards the centerline 33 (see FIG. 1 ). In one embodiment, the second elbow 48 routes the pulse of exhaust gas through a 245 degree turn. The second elbow 48 has substantially a 2.5″ radius of curvature for greater than the 180 degree arc. In one embodiment, the second elbow 48 is not coplanar with the first elbow 46 .
[0046] As shown in FIG. 2 , the second elbow 48 comprises a first sub-elbow 50 and a second sub-elbow 52 joined at a weld 56 . The first sub-elbow 50 and the second sub-elbow 52 are in flow communication. The first sub-elbow 50 has an approximate 180-degree arc while the second sub-elbow 52 has an approximate arc length of less than 90 degrees. In the embodiment illustrated in FIG. 2 , the second sub-elbow 52 has a 65 degree arc length. In one embodiment, the first sub-elbow 50 and the second sub-elbow 52 are not coplanar.
[0047] Connected to and in flow communication with the second elbow 48 is a third elbow 53 . The third elbow 53 routes the pulse of exhaust gas from the second elbow 48 and in a direction towards the centerline 33 when installed (see FIG. 1 ). The third elbow has substantially a 2.5″ radius for an approximate arc length of less than 90 degrees. In the embodiment illustrated in FIG. 2 , the third elbow 53 has an arc length of 75 degrees. The geometry of the third elbow 53 is further illustrated in FIG. 8 . The first, second, third, and fourth elbows are advantageously fabricated from a metallic material. For example, one embodiment utilizes 16-gauge steel with a 1 ¾ inch diameter. Alternatively, a 1 and ⅞ inch diameter is utilized.
[0048] FIG. 3 is a top plan view showing a Harley-Davidson® OEM exhaust system. In contrast to the exhaust system described with reference to FIG. 1 , the Harley-Davidson® OEM exhaust system comprises a stock first exhaust pipe 70 , a stock cross-over exhaust pipe 72 , and a stock second exhaust pipe 74 . The stock first exhaust pipe 70 has an inlet end, an outlet end, and a cross-over connection therebetween. The inlet end is connected to the exhaust port 30 to scavenge each pulse of exhaust gas from engine cylinder 22 . The stock first exhaust pipe 70 is configured to route the scavenged pulse of exhaust gas away from the engine 20 . The outlet end of the stock first exhaust pipe 70 is in flow communication with a first muffler 38 . The cross-over connection connects the stock first exhaust pipe 70 with the stock cross-over exhaust pipe 72 .
[0049] The stock cross-over exhaust pipe 72 has an inlet end and two outlet ends. The inlet end is connected to the exhaust port 32 to scavenge each pulse of exhaust gas from engine cylinder 24 . One of the outlet ends is connected to the stock first exhaust pipe 70 at the cross-over connection location. The other outlet end is connected to the stock second exhaust pipe 74 . The stock cross-over exhaust pipe 72 is configured to route the scavenged pulse of exhaust gas away from the engine 20 and towards both of its outlet ends.
[0050] The stock second exhaust pipe 74 is in flow communication with the stock cross-over pipe 72 and a second muffler 40 . The second muffler 40 is configured to exhaust the pulse of exhaust gas received from the stock second exhaust pipe 74 into the atmosphere.
[0051] In one embodiment of the invention, as illustrated in FIG. 4 , a Harley-Davidson® motorcycle 60 is shown with the upstream pipe 42 from FIG. 2 incorporated into the Harley-Davidson® OEM exhaust system of FIG. 3 . A feature of this embodiment is that the OEM exhaust system is partially retained. Portions of the OEM exhaust system which route the exhaust gases from both cylinders 22 , 24 to the mufflers 38 , 40 are incorporated into the exhaust system shown in FIG. 4 . Referring back to FIGS. 1 and 3 , the upstream pipe 42 can connect with the stock second exhaust pipe 74 of the Harley-Davidson® OEM exhaust system. Moreover, an OEM bracket located under the rider's seat is used to attach the upstream pipe 42 to the motorcycle 60 . The stock second exhaust pipe 74 can route the pulses of exhaust gas from the upstream pipe 42 to the muffler 40 . Alternatively, the stock second exhaust pipe 74 is replaced with the downstream pipe 44 (see FIG. 1 ).
[0052] Referring to FIG. 3 , the stock first exhaust pipe 70 which routes the pulses of exhaust gas from cylinder 22 to the muffler 38 is retained with a slight modification. This modification requires a tubular section (not shown) to be installed where the stock first exhaust pipe 70 connects with the stock cross-over pipe 72 . Alternatively, the stock first exhaust pipe 70 is removed and replaced with the first exhaust pipe 34 .
[0053] FIG. 5 is a side perspective view of a portion of the motorcycle exhaust system encompassed within line 5 of FIG. 4 and shows the upstream pipe 42 of the present invention connected to the cylinder 24 . The upstream pipe 42 routes the pulses of exhaust gas under seat 62 and towards the opposite side of the motorcycle 60 .
[0054] FIG. 6 is a side perspective view of the upstream pipe 42 from FIG. 2 , taken on the opposite side of the motorcycle to that of FIG. 4 . The embodiment of the upstream pipe 42 illustrated in FIG. 6 has a length along a lower dimension that ranges from 6.27 to 7.28 inches. In one advantageous embodiment where the upstream pipe 42 was incorporated into the Harley-Davidson® motorcycle 60 , the length was measured to be 6.775 inches. The upper dimension can range from 4.69 to 5.69 inches. In one embodiment, the upper dimension was measured to be approximately 5.19 inches. However, embodiments of the upstream pipe 42 are not so limited to the embodiments described herein. The upper and lower dimensions are substantially parallel to the centerline 33 (see FIG. 1 ).
[0055] FIG. 7 is a front perspective view of the upstream pipe 42 from FIG. 2 , as installed on the motorcycle of FIG. 4 showing the first elbow 46 and the first sub-elbow 50 lying in different planes. The width of the upstream pipe 42 , as measured in as direction that is perpendicular to the centerline 33 (see FIG. 1 ), ranges from approximately 9.27 to 10.27 inches. In one advantageous embodiment where the upstream pipe 42 was incorporated into the Harley-Davidson® motorcycle 60 , the width of the upstream pipe was measured to be 9.77 inches.
[0056] FIG. 8 is a rear perspective view of the upstream pipe 42 , from FIG. 2 , as installed on the motorcycle of FIG. 4 showing the first sub-elbow 50 and the second sub-elbow 52 lying in different planes. The third elbow 53 is shown routing the pulse of exhaust gas from the first side of the engine 20 (see FIG. 1 ) and towards the centerline 33 (see FIG. 1 ). As previously described with reference to FIG. 2 , one embodiment of the third elbow 53 has an arc length of 75 degrees.
[0057] As illustrated in FIG. 8 , the distance between an upper surface of the first elbow 46 and a weld location between the first elbow and the first sub-elbow 50 ranges from 1.41 to 2.41 inches. In one advantageous embodiment where the upstream pipe 42 was incorporated into the Harley-Davidson® motorcycle 60 , this distance was measured to be 1.91 inches. As illustrated in FIG. 7 , the distance between an upper surface of the third elbow 53 and a lower surface of the second elbow 48 ranges from 7 to 8 inches. In one advantageous embodiment where the upstream pipe 42 was incorporated into the Harley-Davidson® motorcycle 60 , this distance was measured to be 7.5 inches.
[0058] The invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiment is to be considered in all respects only as illustrative and not restrictive and the scope of the invention is, therefore, indicated by the appended claims rather than the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope. | An exhaust system for an internal combustion engine having a first cylinder and a second cylinder from which pulses of exhaust gas exit and are routed along separate paths towards the exhaust mufflers. The exhaust system independently routes the pulses of exhaust gas from the two cylinders. The exhaust gases that are expelled from the first cylinder are routed through a first exhaust pipe. The exhaust gases that are expelled from the second cylinder are routed through a second exhaust pipe assembly. The second exhaust pipe assembly routes the exhaust gasses from an exhaust port for the second cylinder laterally across the motorcycle to achieve a true dual exhaust system. The second exhaust pipe assembly provides an approximate equal length flow path as compared to the path used by the exhaust gasses that are expelled from the first cylinder. | 5 |
FIELD OF THE INVENTION
This invention relates to a new method for the isolation of functional human leukocytes from used leukocyte-depleting filters. More particularly, this method involves isolating leukocytes from filters which have been used to purify red blood cells or platelets in isolation from leukocytes by back-flushing the used filters with a hemolysis solution, such as cold ammonium chloride, and collecting the functional human leukocytes.
BACKGROUND OF THE INVENTION
Blood banking centers fractionate blood into various components such as plasma, erythrocytes, plateletes, and leukocytes. Each of these components is then used for a specific application. The blood cell differential in whole blood is described in A. K. Abbas et al, "Introduction to Immunology", Cellular and Molecular Immunology, p. 14, Harcourt Brace Jovanovich, Inc. (1991).
Current methods for isolating erythrocytes, platelets and leukocytes from whole blood include using low-speed centrifugation. According to this method, erythrocytes and platelets are separated from leukocytes based on their density. A top layer containing plasma and platelets is removed for the preparation of plasma and platelets and the middle layer containing leukocytes (buffy coats) may be used for induction of cytokines, such as interferons, for isolation of specific cell types for the study of the immune system or for immunotherapy. The bottom layer which contains erythrocyte-rich red cells may be used in transfusions.
This method of isolating red blood cells or platelets from leukocytes by centrifugation is tedious and often does not result in complete separation of the blood cell types. As a result, blood bank centers have begun to use various filtration units to remove leukocytes from the desired red blood cell or platelet preparations. Examples of these filtration units include the Pall RCM® system of Pall Corporation (East Hills, N.Y.), Leukotrap® RC/PL system of Miles Pharmaceuticals, the LeukoNet® system of HemaSure, Inc. and the Sepacell-R/PL™ system of Baxter Healthcare Corporation. These are online filters which collect blood directly from the human vein, rather than indirectly from the centrifugation system. Such online filter units trap and separate leukocytes from erythrocytes and platelets based on cell size exclusion. The smaller erythrocytes easily pass through the filter while the larger leukocytes remained behind trapped in the filter. These filter systems result in a reduction of leukocytes ranging from 82.2% to 99%, depending on the filter system used. [Beitr Infusionsther, 30:152-156 (1992)]
Typically, filters used to prepare red-blood cell or platelet-rich preparations are discarded. However, prior methods have been reported in which leukocytes which remain trapped behind in the filter units have been recovered. For example, one method involves back-flushing five times with 50 mL phosphate buffered saline ("PBS") at 4° C. using a 60 mL syringe [R. Longley et al, J. Immuno. Methods, 121:33-38 (1989)]. The "back-flushing" involves flushing the filters in one direction, opposite to the one which is initially used to remove the leukocytes from the desired preparation. The recovered leukocytes at this point in the purification process, still contain a substantial amount of red blood cells. In order to remove the red blood cells, the eluted leukocyte preparations are then further purified by Histopaque gradient centrifugation. A protocol for the isolation of mononuclear cells by Ficoll-Hypaque gradient centrifugation ("histopaque") is described in J. E. Coligan, Current Protocols in Immunology, Section I, Units 7.1-7.2, John Wiley & Sons (1994). The mononuclear cells are collected in the interface layer and washed with PBS. Typically, a total of 2.76+/-1.17 ×10 8 leukocytes per filter, having a viability of more than 95%, will be isolated by this two-step process. In a 5-10 ml sample, where one would expect 2×10 9 leukocytes to be present per filter, this represents a 14% recovery of leukocytes. In comparison to some published methods, where a 70% recovery of buffy coats is generally anticipated, this recovery rate is small. Leukocytes isolated in such a manner have been shown to be functional in response to phytohemagglutinin (PHA), conconavalin (CONA), and pokeweed mitogens (PWM).
The elution of leukocytes from filters is also described in Kuroda et al, U.S. Pat. No. 4,416,777. This method also required a multi-step process to facilitate removal of red blood cells from leukocytes using a variety of elution solutions: PBS in combination with polyvinyl-pyriolidone, sodium casein, polyvinyl-alcohol or gelatin.
In view of the importance of purifying fully functional human leukocytes for the manufacture of therapeutic products and other applications, many attempts have been made to retrieve leukocytes from various sources. However, methods used to date continue to have many drawbacks. For example, the methods of Kuroda et al, U.S. Pat. No. 4,416,777 and Longley et al, supra, are both multi-step and, therefore, tedious processes. The published methods produce a relatively low number of leukocytes per filter unit. In addition, known methods require processing of the filters within 24 hours after blood collection; otherwise the viability of the leukocytes is greatly impaired. As a result, improved methods for retrieving leukocytes from recycled blood product preparation filters continue to be needed.
SUMMARY OF THE INVENTION
The present invention solves the problem referred to above by providing a means for isolating functional human leukocytes from recycled blood product preparation unit filters which are normally used by blood banks to prepare leukocyte-poor blood products and which are commonly discarded after use. More specifically, blood filters are back-flushed with ammonium chloride (0.83%) solution in a one step isolation process. Advantageously, the ammonium chloride elutes leukocytes free from red blood cells.
According to this method, functional leukocytes free from erythrocytes and platelets are retrieved from recycled filters using a peristaltic pump to back-flush leukocytes with an ammonium chloride solution. The ammonium chloride performs a three-fold function in a single step: (a) it flushes leukocytes from the filters, (b) it lyses the red blood cells, and (c) it dissolves clumps which form while the blood is standing. Using this method, the recovery from Leukotrap® filters is between 6 and 8×10 8 leukocytes per filter unit, i.e., a 30-40% recovery of total leukocytes in one unit of whole blood or 50% recovery of published method for purifying leukocytes directly from whole blood. This represents a substantial improvement over methods used to date. In addition, this method makes possible the recovery of ammonium chloride back-flushed leukocytes having a viability of more than 95% while using a generally discarded source.
DETAILED DESCRIPTION OF THE INVENTION
The present method is advantageous in that it permits a one step recovery of erythrocyte-free leukocytes with a greater recovery of functional leukocytes from generally-discarded filter units. An approximately three fold increase in the amount of functional leukocytes retrieved has been demonstrated by the use of ammonium chloride back-flushing of used filters over previously described methods, which use PBS to back-flush erythrocyte-rich leukocytes followed by Histopaque™ separation, in order to retrieve leukocytes from used filters. The leukocytes recovered by the claimed method are functional, i.e., the cells are capable of being activated by virus or mitogen to produce cytokines, such as interferon, or other immunomodulators.
The method of the present invention represents a significant simplification over previous methods for retrieving leukocytes from filters. The method of the invention involves back-flushing about two times with a minimum of 500 mL of ammonium chloride (between 0.7% (w/v) and 0.9% (w/v), where 0.7% (w/v) means 7 mg/ml or 0.7 g per 100 ml) per filter at between 2° C. and 8° C. using a peristaltic pump or any other equivalent pump, followed by centrifugation to obtain pure leukocytes. This step both flushes the leukocytes from the filters and lyses any remaining red blood cells in the filter.
The yield of functional leukocytes observed with the method of the present invention far surpasses that observed in other methods. Recovery from Leukotrap® filters using the described invention is between 6 to 8×10 8 leukocytes per filter unit. This recovery is about 50% of published methods for purifying leukocytes directly from whole blood. The leukocyte differential of this preparation is also closely similar to the cell types present in whole blood. See, for example, Testa et al, U.S. Pat. No. 5,503,828 ("the ISI method"). The viability of ammonium chloride back-flushed leukocytes is more than 95% leukocytes isolated by the method of the invention.
Advantageously, the described back-flushing process can easily be scaled up to handle a large number of filters with any automated system. Unlike the Histopaque™ method for retrieving filter-bound leukocytes, the ammonium chloride (NH 4 Cl) flushing method is not limited to research-scale. Back-flushing with ammonium chloride (NH 4 Cl) can be automated and scaled up to large production in an industrial setting. For example, this can be achieved using manifold set up, where multiple filters are attached to multiple tubes and connected to a single pump.
Back-flushed leukocytes can then be used for cytokine production, i.e., interferon production after Sendai virus stimulation, for isolation of specific blood cells for immune function study or for immunotherapy. When interferon is produced from the retrieved leukocytes, an interferon titer of 2.3-3.5×10 4 units per mL, as determined by immunoradiometric assay (RMA) assay-can be obtained by these retrieved leukocytes. This interferon titer is comparable to the titer obtained from leukocytes isolated from buffy coats after ammonium chloride treatment. For comparison, see for example U.S. Pat. No. 5,503,828. Interferon productivity from filters processed 24 to 48 hours after blood drawing was similar and comparable to leukocytes purified from buffy coats processed within 24 hours. This is surprising in view of published reports that filters must be processed within 24 hours in order to recover the leukocytes, [Longley et al, supra, at page 37]. The ammonium chloride was able to both lyse the red blood cells (hemolysis) and dissolve the clumps in the filter formed during storage over time. Other equivalent hemolysis solutions are known to those in the art and may be substituted for the ammonium chloride used in the back-flushing of leukocytes from used filters.
In order that this invention may be better understood the following example is set forth. This example is for the purpose of illustration only and not to be construed as limiting the scope of the invention.
EXAMPLE
In this example we describe a process for the recovery of functional human leukocytes from Pall RCM® filters which are normally used by blood centers to prepare a leukocyte depleted blood product and commonly discarded after use.
Commercially available from Pall Corporation, used Pall RCM filters were obtained from American Red Cross, Baltimore after leukodepletion of red blood cells preparations. Each filter represents one unit of blood. Filters were back-flushed with various media including phosphate buffered saline ("PBS"), PBS containing glycerol and trypsin, etc., L-glutamin supplemented minimum essential medium containing Eagle's salts and tricine ("LMEM") and ammonium chloride. The media was back-flushed with the use of a peristaltic pump. The speed of the peristaltic pump used to back-flush filters was varied from 20 to 90 rpm. The wash was then centrifuged at one thousand RPM for seven minutes and cells were resuspended in LMEM for induction.
Our results indicated that the maximum number of cells were recovered when cold (4° C.) 0.83% ammonium chloride was used. In addition, we obtained a maximum recovery of cells using the following optimized conditions:
(a) a minimum of five hundred ml of ammonium chloride per filter to recover the highest number of cells;
(b) a speed of 60 rpm with the specified size of tubing at a flow rate of 172 ml per minute (see Table 1 for results).
TABLE 1______________________________________Interferon Production from LeukocytesRecovered from Pall RCM FiltersLeukocyte recovery and speed of the peristaltic pumpSpeed Recovery Percent Interferon Production Percent of(rpm) (cells/filter) Viability (IRMA U/ml)* Control**______________________________________20 5.5 × 10.sup.8 99 29092 8330 6.3 × 10.sup.8 98 24452 6940 6.5 × 10.sup.8 98 22530 6450 7.1 × 10.sup.8 98 35024 10060 7.8 × 10.sup.8 98 23694 6770 3.5 × 10.sup.8 99 17000 4880 3.4 × 10.sup.8 97 33000 9490 3.3 × 10.sup.8 97 16892 48______________________________________ *5 × 10.sup.6 PBL/ml were used during induction **Interferon production from leukocytes isolated from buffy coats (U.S. Pat. No. 5,503,828)
We processed the filters after a storage period of either 24 hours or 48 hours at 4° C. The results from these experiments are shown in Table 2. We observed some variations from filter to filter. Overall, however, the results at 24 hours and at 48 hours were comparable, indicating that the ammonium chloride was able to dissolve any clumps of cells formed after 24 or 48 hours of collection, as well as lyse the red blood cells. Storage of filters for more than 48 hours, i.e., 72 hours or longer, would also be feasible for isolation of leukocytes and the use of these leukocytes for production of interferons.
TABLE 2______________________________________Interferon Production from Leukocytes Recoveredfrom Pall RCM FiltersTime After Blood Drawing Interferon Percent Recovery ofuctionExperiments (PBL/filter) Percent Viability (IRMA U/ml) Control______________________________________1 5 × 10.sup.8 87 33165 942 3.5 × 10.sup.8 98 593 7.0 × 10.sup.8 96 654 5.1 × 10.sup.8 99 685 4.6 × 10.sup.8 95 806 5.6 × 10.sup.8 97 106______________________________________ Exp. 1, 2 and 3 processed after 24 hr after blood drawing. Exp. 4, 5 and 6 processed after 48 hrs after blood drawing.
Using our optimized parameters we recovered leukocytes in a range between 6 and 8×10 8 cells per filter with a viability of greater than 95%. We observed that the composition of cell types is similar to that which can be obtained from buffy coats using differential staining.
Recovered leukocytes were capable of producing interferon when induced with Sendai virus. Interferon yields in the initial experiments were between 65 and 85 percent of that obtained by leukocytes from buffy coats. Our yield was improved to almost 100% when we optimized our procedures. The total time required to process each filter was approximately one hour. The results from our studies indicate that blood filters are a convenient and ready source of human PBL for the production of interferons.
In our experiments, regarding induction of interferon with the retrieved leukocytes, we observed clumping of cells at the time of virus addition which resulted in inconsistent interferon titers. In order to reduce cell clumping during virus addition, the timing of ammonium chloride treatment was optimized. We observed that an initial incubation of filters for 10-20 minutes on ice after first recovery and an additional wash with ammonium chloride and an incubation of recovered leukocyte solution for 10-15 minutes on ice was optimal for interferon production. Using these criteria, we obtained a similar or higher yield of interferon as produced from buffy coat-isolated leukocytes (see Table 3).
TABLE 3______________________________________Recovery of Leukocytes from Leukotrap ® Filters andInterferon InductionOptimal Recovery Yield and Interferon Production Number of Interferon ProductionFilter No. Cells/Filter (IRMA U/ml) Percent of Control______________________________________1 9.2 × 10.sup.8 47696 1362 7.8 × 10.sup.8 1393 7.8 × 10.sup.8 1214 7.4 × 10.sup.8 123______________________________________ Note: Each filter flushed with 500 ml of Ammonium chloride and incubated for 20 min on ice followed by another wash for 10 min. Filters processed at 24 hrs and 5 × 10.sup.6 PBL/ml used during induction.
In summary, using the above-described method, we recovered about 50% of PBL from each filter (6-8×10 8 ) as compared to typical recovery from buffy coats (1.4×10 9 ) using published methods [See, for example, Cantell, "Production of Human Leukocyte Interferon", Methods in Enzymology, 78:29-38 (1981) and Testa et al, U.S. Pat. No. 5,503,828]. These recovered leukocytes produced similar interferon titers as compared with buffy coat leukocytes under optimized conditions. Advantageously, filters were found to be capable of storage for a period of 48 hours after blood drawing without exhibiting a significant loss in interferon yields. In contrast, buffy coat-isolated leukocytes lose 50% of their interferon inducibility after storage of 48 hours.
While we have presented a number of embodiments of this invention our basic construction can be altered to provide other embodiments which use the processes of this invention. Therefore, it will be appreciated that the scope of this invention is to be defined by the claims attached hereto rather than by the specific embodiments which have been presented by way of example. | A method of recovering functional human leukocytes from blood filters used to deplete leukocyte content from leukocyte-containing blood-cell suspensions is provided. More particularly, this method involves isolating leukocytes from filters which have been used to purify red blood cells or platelets in isolation from leukocytes by back-flushing the used filters with a hemolysis solution, such as cold ammonium chloride, and collecting the functional human leukocytes. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates to display devices and fabrication methods thereof, and in particular, to substrate structures for display applications and fabrication methods thereof.
[0003] 2. Description of the Related Art
[0004] Field emission display (FED) devices are panelized conventional cathode ray tube (CRT) displays. By using screen printing technology, large scale FED devices can be achieved. Conventional large scale FED devices have many advantages such as low volume, light weight, low power consumption, excellent image quality, and applicability to a variety of electronic and communication devices. Carbon nanotube or other nano-scale field emitters have benefits such as low threshold field, high emission current density, and high stability due to lower threshold voltage, higher light efficiency, higher viewing angle, and lower power consumption.
[0005] FIG. 1 is cross section of a conventional field emission display device. In FIG. 1 , a field emission display device 10 comprises a pair of opposing parallel substrates 11 and 12 . The lower substrate 11 comprises a cathode electrode, gate line and electron field emitter 13 thereon. The upper substrate 12 comprises an anode electrode 14 . A phosphor layer 15 is applied on the anode electrode 14 . When a bias is applied between the cathode and anode electrodes, electrons emit from field emitter (or cathode electrode) toward the anode electrode and then bombard phosphor layer 15 exciting visible light. Large scale FED devices can be used as a back light, referred to as field emission back light unit (FE-BLU). Conventional FE-BLU and FED, however, require a lithographic process to achieve high resolution patterned electrodes. If the electrodes can be patterned by screen printing, intricate exposure apparatus, development apparatus and consumption of developer can be saved, thus reducing production cost.
[0006] FIGS. 2A-2D are cross sections showing the lithographic fabrication steps of a conventional FED device. Referring to FIG. 2A , a lower substrate 22 such as transparent glass substrate is provided. A conductive layer 21 is deposited on the lower substrate 11 .
[0007] Referring to FIG. 2B , the conductive layer 21 is patterned by lithography. For example, a photo resist (not shown) is applied on the conductive layer 21 . A mask 51 is disposed on the photo resist exposed under a UV light source. After developing, the conductive layer 21 is etched and patterned, as shown in FIG. 2C . The patterned conductive layer comprises a cathode pattern 24 and a gate line pattern 36 .
[0008] Referring to FIG. 2D , a carbon nanotube field emitter 25 is subsequently formed on the cathode pattern 24 . For example, a carbon nanotube paste is screen printed on the cathode pattern 24 . After photo spacers and ribs are formed on the lower substrate, the lower substrate and upper substrate are assembled, completing fabrication of the FED device.
[0009] Conventional screen printing technology uses a squeegee to press paste through a patterned screen, thereby transferring the pattern to a substrate. Thick film screen printing technology is a well-developed technology for reducing cost and mass production in conventional electronic industries. Resolution of thick film screen printing, however, is limited by screen meshes and spread of patterned paste, hindering high resolution printing. For example, referring to FIG. 3 , a paste pattern 120 is transferred onto a substrate 110 by screen printing. Since the interface between the paste pattern 120 and the substrate 110 includes low contact angle a, spread of the paste pattern 120 occurs leading to low resolution. More specifically, the contact angle between cathode paste pattern and the glass substrate is very small, thus spread of the cathode paste pattern on the glass substrate deteriorates. Further, if the viscosity of the paste is low, the printed pattern line width can be twice as wide as the pattern line width on the screen mesh, reducing line width resolution. Thus, eliminating paste spread to improve line width resolution from several hundreds of micrometers to several tens of micrometers in resolution is desirable.
BRIEF SUMMARY OF THE INVENTION
[0010] Accordingly, substrate structures for display applications are provided by interposing an interfacial layer between the paste pattern and the substrate to prevent spread of the paste pattern and to achieve high density, high resolution FED devices.
[0011] The invention provides a substrate structure, comprising: a substrate, an interfacial layer disposed on the substrate, and a patterned paste layer applied on the interfacial layer, wherein a contact angle of the interface between the patterned paste layer and the interfacial layer exceeds 35 degrees.
[0012] The invention further provides a substrate structure, comprising a substrate, an interfacial layer disposed on the substrate, a patterned paste layer applied on the interfacial layer, a dielectric layer disposed on the patterned paste layer, and a gate electrode disposed on the dielectric layer, wherein a contact angle of the interface between the patterned paste layer and the interfacial layer exceeds 35 degrees.
[0013] The invention further provides a substrate structure, comprising a substrate, an interfacial layer disposed on the substrate, a patterned paste layer applied on the interfacial layer, a patterned insulating wall structure disposed on the interfacial layer dividing a plurality of pixel regions, and a fluorescent layer disposed in each pixel region covering the patterned paste layer, wherein a contact angle of the interface between the patterned paste layer and the interfacial layer exceeds 35 degrees.
[0014] The invention still further provides a method of fabricating a substrate structure. A substrate is provided. A surface treatment process is performed on the substrate to change the polarity of the substrate. A patterned paste layer is applied on the treated surface of the substrate, wherein a contact angle of the interface between the patterned paste layer and the treated surface of the substrate exceeds 35 degrees.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:
[0016] FIG. 1 is cross section of a conventional field emission display device;
[0017] FIGS. 2A-2D are cross sections showing the lithographic fabrication steps of a conventional FED device;
[0018] FIG. 3 is a schematic view of a paste pattern transferred onto a substrate by screen printing which includes a low contact angle α leading to low resolution;
[0019] FIGS. 4A-4C are cross sections showing fabrication steps of a substrate structure for a field emission back light unit (FE-BLU) according to an embodiment of the invention;
[0020] FIG. 5 is a cross section of a CNT-FED device according to an exemplary embodiment of the invention;
[0021] FIGS. 6A-6C are cross sections showing fabrication steps of a substrate structure for a plasma display panel (PDP) according to another embodiment of the invention; and
[0022] FIG. 7 is a cross section of a PDP device according to another exemplary embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] The following description is of the best-contemplated mode of carrying out the invention. This description is made for the purpose of illustrating the general principles of the invention and should not be taken in a limiting sense. The scope of the invention is best determined by reference to the appended claims.
[0024] The invention is directed to a substrate structure for display applications. An interfacial layer is disposed on a substrate to prevent spread of electrode paste patterns on the substrate. The interfacial layer can improve surface tension of the electrode paste and reduce wettability between the electrode paste patterns and the substrate. The contact angle between the electrode paste patterns and the interfacial layer is preferably greater than 35°, more preferably greater than 40°. Since the interfacial layer can prevent spread of electrode paste, the contact angle between the electrode paste pattern and the interfacial layer is greater the contact angle between the electrode paste pattern and the substrate. Compared with printing an electron paste pattern of 50 μm line width and 50 μm line interval on a glass substrate, the contact angle can increase by at least 15° due to addition of the interfacial layer. Moreover, a substrate structure with a high resolution electron paste pattern of 17 μm line width and 83 μm line interval can further achieved due to addition of the interfacial layer.
[0025] FIGS. 4A-4C are cross sections showing fabrication steps of a substrate structure for a field emission back light unit (FE-BLU) according to an embodiment of the invention. Referring to FIG. 4A , a substrate 210 such as a transparent glass substrate or a flexible substrate is provided. An interfacial layer 220 or formed on the substrate 210 . The interfacial layer 220 can prevent spread of subsequent printed electrode paste patterns and improve surface tension of the electrode paste patterns. The contact angle between the electrode paste patterns and the interfacial layer is preferably greater than 35°, more preferably greater than 40°. Any interfacial layer which can increase the contact angle by at least 15° is suitable for preventing spread of the electrode paste pattern.
[0026] Referring to FIG. 4B , an electrode patterns including a cathode electrode pattern 224 and a gate line pattern 222 are formed on the interfacial layer 220 . For example, a patterned conductive paste layer is screen printed on the interfacial layer 220 . Since the difference in wettability between the patterned conductive paste layer and the interfacial layer 220 is apparent, the surface tension of the patterned conductive paste layer on the interfacial layer 220 is strong, resulting in a high contact angle between the patterned conductive paste layer and the interfacial layer 220 . Compared with printing a patterned conductive paste layer directly formed on the glass substrate, the contact angle can increase at least 15° due to addition of the interfacial layer.
[0027] Referring to FIG. 4C , a carbon nanotube field emitter 225 is formed on the cathode electrode pattern 224 . For example, a carbon nanotube paste is screen printed on the cathode electrode pattern 224 . The interface between the carbon nanotube paste and the cathode electrode pattern 224 includes a high contact angle to prevent spread of the carbon nanotube paste pattern on the cathode electrode pattern 224 . Subsequently, a photo spacer and a continuous rib are formed on the substrate structure. The substrate structure is assembled with a corresponding upper substrate, thus, fabrication of a FED or a FE-BLU is complete.
[0028] According to embodiments of the invention, the interfacial layer can be transparent or opaque. The interfacial later can comprises conductive or metallic materials. The interfacial layer and the electrode paste pattern can be co-fired for process simplification. Note that any material which can increase the contact angle at least 15° is suitable for the interfacial layer to prevent spread of the electrode paste patterns.
[0029] The interfacial layer can comprise insulating materials, such as SiO 2 , SiO y , SiN x , SiC, B 2 O 3 , Al 2 O 3 , SrBaTiO 3 , ZnS, ZrO 2 , BST, PZT, HfSiO z , HfO 2 , ZnO or Polyimide. The interfacial layer can alternatively comprise Pb, Zn, B, Si, or Bi, or oxides thereof which are sintered at low temperature with high transparency and flatness. Moreover, the interfacial layer can alternatively comprise conductive material such as Ag, Cu, Au, Pd, Pt, CNT, or other electrode materials which can serve as an interface between an electrode and an electrode field emitter. The interfacial layer can alternatively comprise a green tape. The green tape can preferably comprise a silicide, a boride, a metal oxide, a metal nitride, or combination thereof Moreover, the patterned paste layer comprises an emitter paste, phosphor paste, conductor paste, dielectric layer paste, or binder layer paste. For example, the emitter paste may comprise carbon nanotube (CNT), diamond like carbon (DLC), graphite, PdO, or TiO W . The conductor paste may comprise a metal paste (e.g, Ag, Au, Cu, Pt, or Pd), or conducting polymer (e.g., PEDOT or polyaniline). The dielectric paste may comprise SiO 2 , SiO y , SiN x , SiC, B 2 O 3 , ZnO, ZnS, ZrO 2 , BST, PZT, HfSiO z , HfO 2 , or polyimide. The interfacial layer can alternatively comprise a sintered silicon oxide, aluminum oxide, or combinations thereof. Note that a surface improvement process can be performed on the substrate. For example, the interfacial layer can be formed on a sand blasted substrate to remedy a damaged substrate surface to increase contact angle.
[0030] Accordingly, the interfacial layer for use in the present invention is not limited to those types described above, and may be of the other types if applicable to the present invention. Several materials with different surface tension and wettability can be chosen to serve as an electrode comprising a high contact angle with an electron field emitter thereon. The straightness and resolution of the screen printing can be improved due to the interfacial layer. Those skilled in the art will appreciate that other substrate structures, such as FE-BLU, CNT-FED structures and plasma display panels (PDP), are also applicable to the invention.
[0031] FIG. 5 is a cross section of a CNT-FED device according to an exemplary embodiment of the invention. In FIG. 5 , a CNT-FED device 500 comprises a lower substrate 501 and an upper substrate 502 . A wall structure 550 or a rib structure separating the lower and upper substrates with a predetermined gap G. The lower and upper substrates are sealed in vacuum. An interfacial layer 505 is disposed on the lower substrate 501 . A patterned cathode structure 510 is formed on the interfacial layer 505 . A CNT thick film 515 is disposed on the patterned cathode structure 510 to serve as an electron field emitter. A dielectric layer 520 surrounding the patterned cathode structure 510 is disposed on the lower substrate 501 . A gate electrode 530 is disposed on the dielectric layer 520 .
[0032] An anode electrode 560 is disposed on the upper substrate 502 . Red, green, and blue fluorescent layers 575 are alternately disposed on the anode electrode 560 . A black matrix 570 is disposed between the red, green, and blue fluorescent layers 575 .
[0033] FIGS. 6A-6C are cross sections showing fabrication steps of a substrate structure for a plasma display panel (PDP) according to another embodiment of the invention. Referring to FIG. 5A , a substrate 610 such as a transparent glass substrate or a flexible substrate is provided. An interfacial layer 620 is formed on the substrate 610 . The interfacial layer 620 can prevent spread of subsequently printed electrode paste patterns and improve surface tension of the electrode paste patterns. The contact angle between the electrode paste patterns and the interfacial layer is preferably greater than 35°, more preferably greater than 40°. Any interfacial layer which can increase the contact angle by at least 15° is suitable for preventing spread of the electrode paste patterns.
[0034] Subsequently, a patterned cathode electrode 630 or data electrode is formed on the interfacial layer 620 . For example, a patterned conductive paste layer is screen printed on the interfacial layer 620 . Since the difference in wettability between the patterned conductive paste layer and the interfacial layer 620 is apparent, the surface tension of the patterned conductive paste layer on the interfacial layer 620 is strong, resulting in a high contact angle between the patterned conductive paste layer and the interfacial layer 620 . Compared with printing a patterned conductive paste pattern layer directly formed on the glass substrate, the contact angle can increase by at least 15° due to addition of the interfacial layer.
[0035] Referring to FIG. 6B , a patterned continuous rib structure 640 is formed on the interfacial layer 620 dividing a plurality of pixel regions. For example, a photoresist layer is formed on the interfacial layer 620 and then patterned. Alternatively, the photoresist layer can be directly screen printed on the interfacial layer 620 . The interface between the patterned continuous rib structure 640 and the interfacial layer 620 includes a high contact angle to prevent spread of the patterned continuous rib structure 640 on the interfacial layer 620 .
[0036] Referring to FIG. 6C , a fluorescent layer 650 is formed in each pixel region and covering the patterned cathode electrode 630 . The substrate structure is assembled with a corresponding upper substrate, thus, fabrication of a PDP device is complete.
[0037] FIG. 7 is a cross section of a PDP device according to another exemplary embodiment of the invention. In FIG. 7 , a PDP device 700 comprises a lower substrate 601 and an upper substrate 690 . A wall structure 640 or a rib structure separates the lower and upper substrates with a predetermined gap G. The lower and upper substrates are sealed in vacuum or optionally filled some insert gases sequentially. An interfacial layer 620 is disposed on the lower substrate 610 . A patterned cathode structure 630 is formed on the interfacial layer 620 . A fluorescent layer 650 is formed in each pixel region and covers the patterned cathode electrode 630 .
[0038] The upper substrate 690 comprises an anode electrode structure including a scan electrode 680 a and a sustain electrode 680 b. A dielectric layer 670 is disposed on the upper substrate 690 covering the scan electrode 680 a and the sustain electrode 680 b. A passivation layer 660 such as an MgO layer is disposed on the dielectric layer 670 .
[0039] Accordingly, the invention is advantageous in that an interfacial layer which can control surface tension between a glass substrate and a patterned paste is formed on a substrate structure. The interfacial layer can change wettability between the glass substrate and the patterned paste. Since the interfacial layer can maintain surface tension between the glass substrate and the patterned paste, the contact angle increases due to the interfacial layer. A high contact angle can prevent the spread of the patterned paste, thereby reducing the interval of line patterns and increasing resolution. Moreover, the interfacial layer can be a highly transparent material to meet requirements for FE-BLU. A sand blast pretreatment may be needed on the glass substrate. The sand blasted glass substrate, however, comprises a low contact angle, leading to spread of the patterned paste. The interfacial layer can be formed on the substrate treated by sand blasting to remedy damage due to the sand blasting.
[0040] Compared with printing an electron paste pattern of 50 μm line width and 50 μm line interval on a glass substrate, the contact angle can increase by at least 15° due to addition of the interfacial layer. Moreover, a substrate structure with a high resolution electron paste pattern of 17 μm line width and 83 μm line interval can further be achieved due to addition of the interfacial layer.
[0041] While the invention has been described by way of example and in terms of the preferred embodiments, it is to be understood that the invention is not limited to the disclosed embodiments. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements. | Substrate structures for display devices and fabrication methods thereof The substrate structure comprises a substrate, an interfacial layer disposed on the substrate, and a patterned paste layer applied on the interfacial layer, wherein a contact angle of the interface between the patterned paste layer and the interfacial layer exceeds 35 degrees. | 6 |
FIELD OF INVENTION
[0001] This disclosure relates generally to the field of semiconductor structure, and specifically to inducing tensile stress in a nanostructure of a semiconductor structure.
DESCRIPTION OF RELATED ART
[0002] A semiconductor structure may comprise a number of field effect transistors (FETs); each FET may include a source, a drain, a channel, and a gate. The channel connects the source and the drain, and electrical current flows through the channel from the source to the drain. The electrical current flow is induced in the channel by a voltage applied at the gate. The size of a FET is related to the electrical conductivity of the material that comprises the channel. If the material that comprises the channel has a relatively high conductivity, the FET may be made correspondingly smaller.
[0003] A FET may comprise an n-channel field effect transistor (NFET) or a p-channel field effect transistor (PFET). The electrical conductivity of an NFET is determined by the electron mobility of the NFET channel. In some semiconductor materials, the electron mobility of the NFET channel is related to the amount of tensile stress in the NFET material; more specifically, increased tensile stress in the NFET material may raise the electron mobility of some NFET materials.
[0004] In a relatively small FET, a channel may comprise a nanostructure, also referred to as a nanowire. An exemplary nanowire may have a cross-sectional area of about 20 nanometers (nm) by 20 nm or less. Due to the small size and freestanding nature of a nanowire, inducing tensile stress in a nanowire may present difficulties.
SUMMARY
[0005] In one aspect, a semiconductor structure includes an n-channel field effect transistor (NFET) nanowire, the NFET nanowire comprising a film wrapping around a core of the NFET nanowire, the film wrapping configured to provide tensile stress in the NFET nanowire.
[0006] In one aspect, a method of making a semiconductor structure includes growing a film wrapping around a core of an n-channel field effect transistor (NFET) nanowire of the semiconductor structure, the film wrapping being configured to provide tensile stress in the NFET nanowire.
[0007] Additional features are realized through the techniques of the present exemplary embodiment. Other embodiments are described in detail herein and are considered a part of what is claimed. For a better understanding of the features of the exemplary embodiment, refer to the description and to the drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0008] Referring now to the drawings wherein like elements are numbered alike in the several FIGURES:
[0009] FIG. 1 illustrates an embodiment of a cross-section of a semiconductor structure after application of a layer of germanium (Ge).
[0010] FIG. 2 illustrates an embodiment of a cross-section of a semiconductor structure after thermal mixing of silicon (Si) and Ge layers.
[0011] FIG. 3 illustrates an embodiment of a cross-section of a semiconductor structure after application of photoresist.
[0012] FIG. 4 illustrates an embodiment of a cross-section of a semiconductor structure after initial formation of the nanowire regions.
[0013] FIG. 5 illustrates an embodiment of a cross-section of a semiconductor structure after removal of the photoresist and etching of the buried insulator layer.
[0014] FIG. 6 illustrates an embodiment of a cross-section of a semiconductor structure after oxide thinning
[0015] FIG. 7 illustrates an embodiment of a cross-section of a semiconductor structure after formation of a Si wrapping on the SiGe wire wherein the PFET Si wire is thickened
[0016] FIG. 8 illustrates an embodiment of a cross-section of a semiconductor structure after formation of a Si wrapping on the SiGe wire wherein the PFET Si wire is not thickened.
[0017] FIG. 9 illustrates an embodiment of a side view of a semiconductor structure comprising a wrapped NFET nanowire.
[0018] FIG. 10 illustrates an embodiment of a method for a process of making a semiconductor structure comprising a wrapped NFET nanowire.
DETAILED DESCRIPTION
[0019] Embodiments of a wrapped NFET nanowire are provided, with exemplary embodiments being discussed below in detail.
[0020] A film wrapping on an NFET nanowire may enhance tensile stress in the NFET nanowire, enhancing the electron mobility in the NFET nanowire. In an exemplary embodiment, wrapping silicon (Si) around a silicon germanium (SiGe) core may provide tensile stress in an NFET nanowire.
[0021] For an example SiGe core with a cross section that comprises a square with a side length of 5 nanometers (nm), the cross-sectional area of the SiGe core is 25 nm 2 . The SiGe core is relaxed (i.e., has minimal stress) because it is freestanding. A silicon film wrapping that conforms to the SiGe core potentially causes a tensile stress in the Si of about 1.75 gigapascals (GPa). This tensile stress may increase the electron mobility of the overall nanowire, which comprises the SiGe core and the Si film wrapping.
[0022] FIG. 1 illustrates an embodiment of a cross-section of a semiconductor structure after application of a layer 50 of Ge. Layer 10 comprises a substrate, which may comprise silicon in some embodiments. Layer 20 comprises buried insulator, which may comprise a dielectric material such as oxide in some embodiments. Layer 50 comprises Ge, and is disposed on Si layer 40 . Layer 30 comprises Si.
[0023] FIG. 2 illustrates an embodiment of a cross-section of a semiconductor structure after thermal mixing of Si layer 40 and Ge layer 50 . Layers 40 and 50 of FIG. 1 have been thermally mixed, resulting in SiGe layer 60 . Layer 30 comprises Si, layer 20 comprises buried insulator, and layer 10 comprises substrate. In some embodiments, SiGe layer 60 may be thinned, or Si layer 30 may be thickened, as necessary in order to achieve appropriate dimensions for layers 30 and 60 .
[0024] FIG. 3 illustrates an embodiment of a cross-section of a semiconductor structure after application of photoresist. Photoresist layers 70 a and 70 b are placed on SiGe layer 60 and Si layer 30 , respectively, to define nanowire regions. Layer 20 comprises buried insulator, and layer 10 comprises substrate.
[0025] FIG. 4 illustrates an embodiment of a cross-section of a semiconductor structure after initial formation of PFET and NFET regions. The SiGe layer 60 and Si layer 30 have been etched down to buried insulator layer 20 , leaving SiGe NFET region 61 under photoresist layer 70 a, and Si PFET region 31 under photoresist layer 70 b. Layer 10 comprises substrate.
[0026] FIG. 5 illustrates an embodiment of a cross-section of a semiconductor structure after removal of the photoresist and etching of the buried insulator layer. The photoresist layers 70 a and 70 b have been etched off, along with a portion of buried insulator layer 20 , resulting in freestanding SiGe NFET region 61 , freestanding Si PFET region 31 , and buried insulator layers 20 a, 20 b, and 20 c. Layer 10 comprises substrate. NFET region 61 and PFET region 31 are tethered to silicon pads 901 and 903 , as discussed below with regards to FIG. 9 .
[0027] FIG. 6 illustrates an embodiment of a cross-section of a semiconductor structure after oxide thinning. Oxide thinning is performed on SiGe NFET region 61 and Si PFET region 31 , resulting in SiGe core 62 and Si wire 32 . SiGe core 62 and Si wire 32 may each have a cross-sectional area of about 20 nm by about 20 nm or less. Layers 20 a, 20 b , and 20 c comprise buried insulator, and layer 10 comprises substrate.
[0028] FIG. 7 illustrates an embodiment of a cross-section of a semiconductor structure after formation of a Si film wrapping 80 on SiGe core 62 and thickening of Si wire 32 , resulting in thickened Si PFET nanowire 34 . Layers 20 a, 20 b, and 20 c comprise buried insulator, and layer 10 comprises substrate. Si film wrapping 80 provides tensile stress in the NFET; together, Si film wrapping 80 and SiGe core 62 form an NFET nanowire. Si film wrapping 80 may have a thickness between about 1 and 2 nm.
[0029] FIG. 8 illustrates an embodiment of a cross-section of a semiconductor structure after formation of a Si film wrapping 80 on SiGe core 62 in which Si wire 32 is not thickened. The Si PFET wire 32 of FIG. 6 is masked, and Si film wrapping 80 is grown on SiGe NFET wire 62 . Layers 20 a, 20 b, and 20 c comprise buried insulator, and layer 10 comprises substrate. Si film wrapping 80 provides tensile stress in the NFET; together, Si film wrapping 80 and SiGe core 62 form an NFET nanowire. Si wire 32 comprises a PFET nanowire. Si film wrapping 80 may have a thickness between about 1 and 2 nm.
[0030] FIG. 9 illustrates a side view of an embodiment of a semiconductor structure comprising a wrapped NFET nanowire. SiGe core 62 is surrounded by Si wrapping 80 , together forming an NFET nanowire. Film wrapping 80 provides tensile stress in the NFET nanowire. Pad 901 and pedestal 902 are on the source side of the semiconductor structure, and pad 903 and pedestal 904 are on the drain side of the semiconductor structure. Electrical current flows through SiGe core 62 and Si film wrapping 80 from source-side pad 901 to drain-side pad 903 according to a voltage applied at gate 905 . Layer 20 comprises buried insulator, and layer 10 comprises substrate.
[0031] FIG. 10 illustrates a method 1000 for a process of making a semiconductor structure comprising a film wrapped NFET nanowire. In block 1001 , a germanium layer is disposed on a portion of an exposed silicon layer, as is shown in FIG. 1 . In block 1002 , the germanium layer and the silicon layer are thermally mixed, resulting in an exposed SiGe layer and an exposed Si layer, as is shown in FIG. 2 . In block 1003 , a layer of photoresist is applied to a portion of the SiGe layer, and a layer of photoresist is applied to the Si layer, as is shown in FIG. 3 . In block 1004 , the exposed SiGe and Si layers are etched down to a buried insulator layer, leaving the portions of the SiGe and the Si located under the photoresist layers, as is shown in FIG. 4 . In block 1005 , the photoresist is removed, and the buried insulator is etched, resulting in a freestanding SiGe NFET region and a freestanding Si PFET region, as is shown in FIG. 5 . In block 1006 , the freestanding SiGe NFET region and the freestanding Si PFET region are thinned, resulting in a SiGe NFET core and a Si PFET wire, as is shown in FIG. 6 . In block 1007 , a Si film wrapping is grown. In some embodiments, the Si PFET wire is masked, and the Si film wrapping is grown on the SiGe core, forming the NFET nanowire, as is shown in FIG. 8 . In other embodiments, the Si PFET wire is not masked, and Si is also grown on the Si PFET wire, resulting in a thickened Si PFET nanowire, as is shown in FIG. 7 . The Si film wrapping provides tensile stress in the NFET nanowire, resulting in enhanced electrical conductivity in the NFET nanowire.
[0032] The technical effects and benefits of exemplary embodiments include increased tensile stress in an NFET nanowire, thereby increasing the electrical conductivity of the nanowire and allowing for reduction in size of a semiconductor device.
[0033] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.
[0034] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated. | A semiconductor structure includes an n-channel field effect transistor (NFET) nanowire, the NFET nanowire comprising a film wrapping around a core of the NFET nanowire, the film wrapping configured to provide tensile stress in the NFET nanowire. A method of making a semiconductor structure includes growing a film wrapping around a core of an n-channel field effect transistor (NFET) nanowire of the semiconductor structure, the film wrapping being configured to provide tensile stress in the NFET nanowire. | 1 |
CLAIM OF PRIORITY
[0001] The invention is related to and claims priority from U.S. Provisional Patent Application No. 61/795,942 filed Oct. 31, 2012 to common inventor Gillium, and entitled Mailing Label Based Product Registration.
TECHNICAL FIELD OF THE INVENTION
[0002] The invention relates generally to product registration.
PROBLEM STATEMENT
Interpretation Considerations
[0003] This section describes the technical field in more detail, and discusses problems encountered in the technical field. This section does not describe prior art as defined for purposes of anticipation or obviousness under 35 U.S.C. section 102 or 35 U.S.C. section 103. Thus, nothing stated in the Problem Statement is to be construed as prior art.
Discussion
[0004] Consumers are rarely as brand-loyal as they are retailer-loyal. Indeed, as soon as an item is purchased, unless the purchaser actually registers the product with the manufacturer (and less than ⅓ do), the consumer's relationship with the manufacturer ends. As more consumers shop online, the consumer relationship with the manufacturer continues to grow more distant. Accordingly, what manufacturers need are systems, methods and devices that provide the consumer an easy way to register a product, and the present invention provides such. The invention also provides additional benefits for advertisers unrelated to the manufacturers.
BRIEF DESCRIPTION OF THE DRAWINGS AND TABLE
[0005] Various aspects of the invention, as well as an embodiment, are better understood by reference to the following detailed description. To better understand the invention, the detailed description should be read in conjunction with the drawings and tables (if any).
[0006] FIG. 1 is an inventive product registration algorithm.
[0007] FIG. 2 illustrates an alternative product registration algorithm.
DETAILED DESCRIPTION OF THE INVENTION
Interpretation Considerations
[0008] When reading this section (which describes an exemplary embodiment of the best mode of the invention, hereinafter “exemplary embodiment”), one should keep in mind several points. First, the following exemplary embodiment is what the inventor believes to be the best mode for practicing the invention at the time this patent was filed. Thus, since one of ordinary skill in the art may recognize from the following exemplary embodiment that substantially equivalent structures or substantially equivalent acts may be used to achieve the same results in exactly the same way, or to achieve the same results in a not dissimilar way, the following exemplary embodiment should not be interpreted as limiting the invention to one embodiment.
[0009] Likewise, individual aspects (sometimes called species) of the invention are provided as examples, and, accordingly, one of ordinary skill in the art may recognize from a following exemplary structure (or a following exemplary act) that a substantially equivalent structure or substantially equivalent act may be used to either achieve the same results in substantially the same way, or to achieve the same results in a not dissimilar way.
[0010] Accordingly, the discussion of a species (or a specific item) invokes the genus (the class of items) to which that species belongs as well as related species in that genus. Likewise, the recitation of a genus invokes the species known in the art. Furthermore, it is recognized that as technology develops, a number of additional alternatives to achieve an aspect of the invention may arise. Such advances are hereby incorporated within their respective genus, and should be recognized as being functionally equivalent or structurally equivalent to the aspect shown or described.
[0011] Second, the only essential aspects of the invention are identified by the claims. Thus, aspects of the invention, including elements, acts, functions, and relationships (shown or described) should not be interpreted as being essential unless they are explicitly described and identified as being essential. Third, a function or an act should be interpreted as incorporating all modes of doing that function or act, unless otherwise explicitly stated (for example, one recognizes that “attaching” may be done by hook-and-loop attachment (such as Velcro®), snaps, hooks, belts, etc., and so a use of the word attaching invokes all methods of attachment known in and anticipated by the art, and all other modes of that word and similar words).
[0012] Fourth, unless explicitly stated otherwise, conjunctive words (such as “or”, “and”, “including”, or “comprising” for example) should be interpreted in the inclusive, not the exclusive, sense. Fifth, the words “means” and “step” are provided to facilitate the reader's understanding of the invention and do not mean “means” or “step” as defined in §112, paragraph 6 of 35 U.S.C., unless used as “means for -functioning-” or “step for -functioning-” in the Claims section. Sixth, the invention is also described in view of the Festo decisions, and, in that regard, the claims and the invention incorporate equivalents known, unknown, foreseeable, and unforeseeable. Seventh, the language and each word used in the invention should be given the ordinary interpretation of the language and the word, unless indicated otherwise.
[0013] It should be noted in the following discussion that acts with like names are performed in like manners, unless otherwise stated. Of course, the foregoing discussions and definitions are provided for clarification purposes and are not limiting. Words and phrases are to be given their ordinary plain meaning unless indicated otherwise. The numerous innovative teachings of present application are described with particular reference to presently preferred embodiments.
DESCRIPTION OF THE DRAWINGS
[0014] The invention is in one aspect a product registration algorithm (“the algorithm”) as illustrated in FIG. 1 . The algorithm begins when a database of SKUs (Stock Keeping Units) is generated. Then, a unique product identifier (ID) is created for each SKU. Next, in a Print ID with Label act, at least one label is created and printed with the unique product ID thereon. Following the creation of the label, the label is placed on a package. Eventually, the package is delivered and the ID is scanned (either by the consumer or by the service delivering the package). At this point, the database is queried, and the product delivered is associated with the consumer who receives the package, or with another person (either at the time of scanning or at a later date), which takes place in an information exchange act.
[0015] Following the information exchange, the recipient may “share” or otherwise socialize the purchase or receipt of the item, and the manufacturer or other entity in the supply chain may make an offer to the recipient. Next, the recipient may choose to register the purchase (or item(s)) as their own, including in a “one-click” manner. Following registration of an item by a user, a user profile is updated in a user profile database, and the manufacturer is notified that the registrant has acquired the item in a notify manufacturer act.
[0016] FIG. 2 illustrates an alternative product registration algorithm (a first alternative algorithm). In the first alternative algorithm, a sample label having a desired product identification (ID) thereon is show. The sample label also includes an exemplary offering that may be associated with a product registration. The first alternative algorithm also illustrates a variety of order possibilities associated with a purchase registration algorithm.
[0017] Another way of looking at the registration process is as a step-wise collection of acts, in which:
1. At a manufacturer's database, a Master Item List from the manufacturer is queried for a relevant SKU. 2. Next, a UPC, QR, or PDF417 is generated. In this process, a 2-dimensional barcode is generated for the item in a UPC, QR Code, or PDF417 format. 3. Then, in a QuickRegistration label printed step, a pre-printed full-color label is sent through the printer where the barcode is printed directly onto the label in the whitespace provided. 4. An AdLabel is applied to the outside of an appropriate retail package, and may or may not contain a special offer. 5. Whether in-store or via delivery, the item is purchased. 6. Next, the consumer receives the item(s) either in the store (such as BestBuy®, for example) or via delivery (such as UPS®, FedEx®, or USPS®, for example) 7. Then, the label is scanned, such as with a smartphone. In one embodiment, the Barcode is scanned from a smartphone using a Barcode reading app such as RedLaser® or ShopSavvy®, for example. 8. In a local (non-manufacturer) database, a unique identifier (from the barcode) is sent to a server where it is used to query the local database and present a dynamic Web App back to the smartphone (or other smart device, such as a tablet) with preferably an image and basic information about the item, with options. 9. Next, in a web application for registering (and for social interaction, such as “liking”), the web application (hosted on the local server) presents the consumer with options to register their Item, Like it on a social network such as Facebook®, for example. 10. Then, registration of item takes place, whereby the consumer can register the item using one-click log-in (such as through Facebook®). 11. To complete the algorithm, the registration information is delivered back to the manufacturer. Here, the registration information is preferably sent back to the manufacturer utilizing an integration service (such as CommerceHub®, for example), and in a recognizable format such as ANSI x.12 or Item Master 888.
[0029] Although the invention has been described with respect to a specific preferred embodiment, many variations and modifications, including equivalents, will become apparent to those skilled in the art upon reading the present application. It is therefore the intention that the appended claims and their equivalents be interpreted as broadly as possible in view of the prior art to include all such variations and modifications. | The invention disclosed herein provides apparatuses, systems and methods for quickly and easily registering a product, and for storing data in profiles such that advertisements and offers may be delivered in a targeted manner. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b). | 6 |
BACKGROUND OF THE INVENTION
This application is a continuation-in-part of Application Ser. No. 624,281, filed Oct. 20, 1975 now abandoned.
This invention relates in general to a wind energy power system of the type using a multiblade propeller for producing power from wind energy. More particularly, the invention relates to a multiblade, wind-driven, variable pitch propeller supported at the top of a tower and connected through a gear arrangement for driving an output shaft supported on the tower. The output shaft may be connected to power a pump for pumping water, or for operating a compressor for refrigeration or other uses, or for the production of mechanical power for any desired use. Specifically, the invention relates to a system as above, wherein the propeller is used to drive an electric generator for the generation of electrical energy.
In the prior art, many different types of wind electric plants have been provided for generating electrical power from wind energy, as exemplified, for example, in U.S. Pat. Nos. 1,979,616, 2,050,142, 2,096,860, 2,464,234 and 2,505,969. Some of the wind electric plants disclosed in these prior art patents utilize variable pitch propeller blades, which are automatically governed or self-regulating for changing wind conditions. However, prior art wind electric plants typically have relatively small diameter propellers, as, for example, on the order of about 10 feet in diameter, and accordingly, the forces encountered are relatively small and easy to handle. For example, pitch adjusting structures and blade stop means can be accommodated through various parts of the governor structure, and pitch changes of the propeller blades can be accomplished at all operating speeds of the wind plants. Also, installation and service of such prior art systems is relatively easy to accomplish, since spring forces and propeller blade sizes and weights and the like are relatively small and thus easy to handle.
Recently, however, there has been increasing demand for larger propellers for production of greater amounts of horsepower and electrical energy output. Such larger propellers, for example, range upward to about 25 feet in diameter. At these propeller sizes, conventional structures and arrangements and pitch adjusting features are not capable of withstanding the loads encountered. Further, the propeller blades must be repositioned in order to afford adequate clearance thereof with the supporting tower. Moreover, it has been found that with these larger propeller blades, changes in pitch could not be effectively accomplished with conventional structures, and damage to the propeller blades results at higher wind velocities. Additionally, with the larger propellers, greater amounts of torque are encountered, and conventional spring arrangements are not capable of controlling the blade operation, and further, failure of the spring mounting bolts frequently occurs after a short period of use. Still further, conventional blade adjusting structures are not suitable for use with the larger propeller blades, and more direct attachment and engagement of the blade pitch adjusting bolts and blade return stop bolts is required.
Therefore, in accordance with the present invention, a unique wind electric plant is provided which is constructed to withstand the larger forces encountered when larger propellers are used, and means are provided to effectively solve all of the problems set forth above which are found with prior art devices.
OBJECTS OF THE INVENTION
It is, therefore, an object of this invention to provide a wind power plant of the type incorporating a multiblade, variable pitch propeller, wherein the propeller is supported on a tower with the plane of propeller rotation angularly disposed relative to the axis of the tower to thereby obtain adequate propeller blade-tower clearance, and also to enable the propeller hub to be mounted closely adjacent the gear drive connection on the tower for driving an electric generator or other suitable devices.
Another object of the invention is to provide a unique blade return spring construction, which has snubber means associated therewith for slowing the action of the spring and thus preventing excessively rapid pitch changes and thereby avoiding destructive flutter of the propeller blades during operation at high wind velocities.
A still further object of the invention is to provide a double spring arrangement for returning the blades to their stop position, whereby the return force of the springs can be combined to operate effectively with large propeller blades, and which also spread the force of the springs over a larger area of the propellers and hub structure to eliminate excessive forces which would be required if single springs were used, as in some prior art devices.
Yet another object of the invention is to provide a unique blade return spring mounting bracket associated with the hub in a manner such that in the event one or more of the springs breaks or the like, the bracket is automatically adjustable to permit all of the propeller blades to feather and thus prevent damage to the plant.
A still further object of the invention is to provide a direct engagement between the blade return stop bolt and the hub of the propeller, whereby damaging forces on the hub structure and/or other elements of the propeller blade control structure is avoided with the larger diameter propellers.
A still further object of the invention is to provide a unique self-centering, double-acting pivot washer for connection between the return spring and the blade mounting bracket, whereby accurate centering of the blade mounting bolt in the bracket hole is ensured, and bending forces on the bolt are also eliminated.
An even further object of the invention is to provide a wind electric plant in which the electric generator is supported at a lower position in the tower than in prior art devices for easier servicing thereof, and the generator is connected through a drive shaft arrangement with a ring and pinion gear carried at the top of the tower.
An even further object of the invention is to provide in a wind electric plant of the type having a wind-driven multiblade propeller supported at the top of a tower and connected through a gear arrangement for driving an electric generator, a ring and pinion gear set, wherein the ring gear is eccentrically disposed relative to the axis of the pinion gear, such that the torque forces imparted through the ring and pinion gear are at least partially balanced or offset by the wind forces acting on the propeller, to thus prevent misalignment of the propeller axis relative to the direction of prevailing wind forces.
An even further object of the invention is to provide a wind electric plant wherein the propeller thereof is disposed at an angle relative to the axis of the supporting tower, whereby the angle of attack of the propeller is actually more nearly pointed directly into the direction of prevailing wind forces.
Yet another object of the invention is to provide a wind electric plant of the type having a multiblade propeller and a gear means supported in a tower adjacent the propeller and driven thereby, and vibration damping means connected between the gear means and tower to reduce noise and vibration transmitted into the tower.
A still further object is to provide a wind electric plant of the type including a tower having propeller driven gear means supported thereon and a splined stub shaft extending downwardly therefrom for connection with a drive shaft, whereby the gear means, propeller, drive shaft and the like may be removed and/or serviced without requiring disassembly of the other components of the plant.
An even further object of the invention is to provide a wind electric plant of the type including a propeller driven gear means, wherein the gear means includes a ring gear and meshed hypoid bevel gear, wherein the bevel gear is engaged at the top of the ring gear so as to be positioned above oil in the gear case, to reduce friction losses, particularly in cold climates.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a fragmentary view in elevation, with portions broken away and portions shown in section, of a wind electric plant incorporating the features of the present invention.
FIG. 2 is an enlarged, fragmentary front view of the portion of the propeller near the hub of the device in FIG. 1, with the hub cover or fairing cone shown in phantom lines for purposes of illustration.
FIG. 3 is a view in section taken along line 3--3 of FIG. 1 showing the offset of the ring and pinion gears.
FIG. 4 is a greatly enlarged, fragmentary view in section of one of the snubber devices of the invention and its association with a return spring and spring mounting bracket.
FIG. 5 is an exploded, perspective view, with portions broken away, of the connection of one of the return springs with the blade return spring bracket, and showing the self-centering, double-acting pivot washer associated therewith.
FIG. 6 is a greatly enlarged view in section, taken along line 6--6 in FIG. 2.
FIG. 7 is an enlarged view in section of a portion of the blade return spring bracket, showing the bolt receptive hole therethrough and the aligning pins thereon for cooperation with the pivot washer.
FIG. 8 is a fragmentary front view similar to FIG. 2 of a modified form of the invention, wherein double springs are used on each propeller blade.
FIG. 9 is a slightly enlarged view similar to FIG. 1 of a further modification of the invention, wherein a splined stub shaft and vibration dampers are used.
FIG. 10 is a further enlarged, fragmentary sectional view taken along line 10--10 of FIG. 9.
FIG. 11 is a view similar to FIG. 9 of a further modification of the invention, wherein the pinion or hypoid bevel gear is engaged near the top of the ring gear, and the ring gear rotates in a counterclockwise direction.
FIG. 12 is a view similar to FIG. 10 of the form of the invention in FIG. 11.
FIG. 13 is a fragmentary, enlarged view in section similar to FIG. 12, of a further modification of the invention, for clockwise rotation of the ring gear.
FIG. 14 is an enlarged, fragmentary view in elevation of a modified connection between the snubber springs and spring bracket.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the drawings, wherein like reference numerals indicate like parts throughout the several views, a first form of wind electric plant in accordance with the invention is indicated generally at 10 and comprises a support tower T on which a multiblade, variable pitch propeller P is supported.
The tower T is of substantially conventional construction, and includes a plurality of legs L converging toward one another at their upper ends and having a tower cap C secured thereon. A transverse plate 11 is suitably secured to the legs of the tower spaced downwardly from the tower cap C and an upstanding mast pipe 12 is suitably attached at its lower end to plate 11 and extends upwardly therefrom through the tower cap C and through a turn bearing 13. A gear case 14 has an extension 14a thereon which extends downwardly into the upper end of the mast pipe to support the gear case on the top of the tower. In other words, the plate 11 is rigidly and securely fixed to the tower, and the mast pipe is attached at its lower end to the plate 11 and connected at its upper end to the case 14, so that the case is supported on the tower for rotating movement about the axis of the tower, but is prevented from lateral displacement relative thereto.
A drive shaft 15 extends coaxially within the mast pipe 12 and is rotatable relative thereto and extends upwardly at its upper end through the upper end of the mast pipe and into the interior of the gear case 14 and has a pinion gear or hypoid bevel gear 16 affixed thereto. A propeller shaft 17 extends through the gear case 14 and is inclined to the axis of the tower (about 9° from the horizontal in a preferred form) and offset laterally to one side of the axis of drive shaft 15, as seen in FIG. 3. The propeller 17 is supported in bearings 18 an 19 in the rear and front walls, respectively, of the gear case 14, and extends forwardly of the gear case and has a propeller hub 20 secured thereon and an automatic, pitch adjusting governor arrangement 21 of the type disclosed, for example, in U.S. Pat. No. 2,505,969 or co-pending Application Ser. No. 477,316, is supported. A ring gear 22 is carried by the shaft 17 within the case 14 in operative engagement with the pinion gear 16 for driving the pinion gear whenever the propeller shaft is rotated by the propeller P. A gear case cover 23 is removably attached to the top of the gear case for gaining access to the interior thereof when desired or necessary, and the cover is secured in place by removable fasteners 24, such as stud bolts or the like.
The propeller P comprises a plurality of blades 25 carried by the hub in a manner as described, for example, in the aforesaid patent and co-pending application. Briefly, the propellers 25 are radially slidable on rods 26 secured to the hub and received in cooperating bores in the butt ends of the propeller blades, and the propeller blades are urged radially inwardly on the rods toward the hub 20 by means of return spring structures 27 secured to brackets 28 on the propeller blades and secured to a spring bracket 29 engaged against the hub nut 30 on the forward end of the propeller shaft. The spring bracket is generally cup-shaped, with the open side thereof facing forwardly so that access can be had to the nuts on the spring attaching bolts. A rounded or streamlined fairing cone or cover 31 is supported on the hub in covering relationship to the return springs and bracket 29.
In order to limit the inward movement of the propeller blades on the rods 26, threaded adjustment bolts 32 are threadably extended through the hub 20 into engagement with the butt end of the blades, and lock nuts 33 are engaged on the bolts 32 to lock them in adjusted position. With this arrangement, accurate and easy adjustment of the inward movement of the blades can be easily accomplished to accurately adjust all of the blades to any given hub casting or the like. In other words, in some prior art structures for adjusting the stop position of the propeller blades, the adjustment is made through a linkage arrangement which may be suitable for smaller diameter propellers, but for large diameter propellers as contemplated by the present invention, such adjustments are entirely unsatisfactory.
In order to maintain the propeller properly pointed into the wind, a tail vane 34 is supported from the gear case by a plurality of tail vane braces 35 connected at their rearward ends to the vane 34 and secured at their forward ends to upper and lower brackets 36 and 37, respectively, and to a side bracket (not shown) on the gear case 14.
In the form of the invention shown in FIG. 1, the drive shaft 15 extends downwardly from the pinion gear 16 through the mast pipe 12 and through the plate 11 and has a disc brake rotor 38 secured thereto below the plate 11 for cooperation with disc brake calipers 39 carried by the tower. A cable 40 extends downwardly from the disc brake calipers 39 to a winch 41 near the bottom of the tower, whereby the disc brake calipers may be operated to grip the disc brake rotor 38 to stop rotation of the propeller when desired. Rather than the cable and winch as illustrated and described, any other suitable mechanism may be provided for operating the brake to stop the propeller. For example, a hydraulic system could be used.
A universal joint 42 is carried by the lower end of the drive shaft 15 and is connected with a drive shaft extension 43 having a second universal joint 44 at its lower end, which is connected in turn with the shaft 45 of a suitable electric generator 46 for operating the generator to generate electrical power.
Suitable weather shields 47 and 48, similar to split stovepipes or the like, are positioned around the drive shafts 15 and 43 in protective relationship with the drive shafts, disc brake assembly and universal joints, and the shields have longitudinal flanges 49 and 50 thereon, respectively, through which suitable fasteners 51 extend for securing the shields in place around the drive shafts.
The generator 46 is supported from a second transverse plate 52 carried by the tower, and the generator shaft 45 extends through the plate 52.
An inverted, cup-shaped weather shield 53 is supported beneath the plate 52 above the generator 46 for shielding the generator from weather and the like.
An elongate, tubular shield or chimney 54 is secured to the generator 46 and extends downwardly therefrom and has a screened lower end 55 for ingress of air into the tube 54 and flow upwardly through the tube and through the generator and outwardly through a screened grill 56 at the upper end of the generator for cooling the generator. An air circulating fan 57 is driven by the generator for forcing air upwardly through the chimney or tube 54 and through the generator to cool it.
Electrical cables 58 extend from the generator downwardly to the ground for conducting electrical energy to a suitable point of use.
If desired, the generator 46 may be of the type which does not require an exciter, as described in co-pending Application Ser. No. 477,316.
As seen best in FIGS. 4 and 5, the spring assemblies 27 each comprise an elongate coil spring 59 having hook-shaped formations 60 and 61 at the opposite ends thereof engaged with eye bolts 62 and 63. A snubber 64 is positioned coaxially around the coil spring 59 and comprises a pair of elongate tubular members 65 and 66 telescopically engaged with one another and slidably sealed by means of an O-ring 67 positioned in an enlarged seal pocket 68 in one end of the housing portion 66. The eye bolts 62 and 63 extend through openings in the outer ends of the housing portions 65 and 66 and are sealed relative thereto by means of gaskets 69 and 70. The eye bolt 62 extends through the wall of the spring bracket 29 and is secured thereto by means of a nut 71. A washer 72 is engaged between the wall of bracket 29 and the end of housing member or portion 66. The other eye bolt 63 has an enlarged threaded portion 73 thereon, on which a nut 74 is engaged to secure the eye bolt to the end of housing member 65. Eye bolt 63 extends beyond the threaded portion 73 and through a flared opening 75 in the bracket 28. A self-aligning pivot washer 76 is positioned over the end of the bolt 63 projecting through the bracket 28. The washer 76 is of solid construction and has upstanding ribs 77 on one side thereof and similar upstanding ribs 78 on the other side thereof extending at a right angle to the axis of ribs 77. Further, a pair of upstanding centering pins 79 are on the bracket 28 on opposite sides of the flared hole 75 and the pins 79 extend into a pair of aligned openings 80 in the ribs 77 on the underside of washer 76, whereby the washer is accurately positioned and centered relative to the hole 75. A pair of retaining nuts 81 are threaded onto the end of bolt 63 against washer 76 to tension the spring 59 and effect the desired inward bias on the propeller blade.
In use, the snubber 64 acts much like a shock absorber to prevent rapid changes in pitch of the propeller blade due to the momentum effect caused by the weight of the larger propeller blades, and thus hunting and flutter of the propeller blades is prevented.
The butt ends of the blades 25 are adjustably fixed to an angle bracket 82, through one flange of which the rod 26 extends and through the other flange of which a plurality of blade attaching bolts 83 extend. The initial pitch of the blades may be adjusted with a high degree of accuracy by loosening nuts 84 on bolts 83 and loosening nuts 85 on pitch adjusting bolts 86 and then adjusting the bolts 86 inwardly or outwardly as necessary and retightening the nuts 84 and 85.
With the arrangement shown in FIG. 6, adjustment of the pitch of the blades is easily accomplished and there is little problem of not being able to adjust the blades due to rusting of the bolts and the like, as frequently occurs with prior art blade adjusting devices.
A modified propeller arrangement is indicated generally at P' in FIG. 8, and is substantially identical with the form of the invention illustrated in FIGS. 1-7, except that in this instance, for very large propellers a pair of spring assemblies 27 are provided for each blade, rather than the single spring assemblies as in the previous embodiment. A wider spring attaching bracket 28' is carried by each propeller blade, such that the force exerted by the springs is distributed over a larger area of the propeller blades, thus reducing the stresses imposed thereon from the spring force. Also, a modified spring attaching bracket 29' is disposed against the end of the hub for interconnection of the spring assemblies 27, and as seen in FIG. 8, the modified spring attaching bracket 29' is generally of triangular shape.
Propeller blades in accordance with the present invention may range upwardly of about 25 feet in diameter, and thus very large forces are created, and in fact, the spring force necessary to properly control such large propeller blades may approach or even exceed 4,000 pounds. Accordingly, the unsuitability of conventional structures is readily apparent. Additionally, with the large propeller sizes contemplated by the present invention, most of the problems encountered in wind electric plants are magnified in comparison with conventional prior art arrangements, and in fact, the offset arrangement of the ring and pinion gear, as shown in FIG. 3, is necessary in order to effect a balance between the torque forces generated between the ring and pinion gears and the wind forces imposed on the propeller. In other words, the propeller blades used in apparatus like the present invention are highly efficient, and very little wind force is present behind the propeller, with the result that the tail vane 34 has little appreciable effect until a high angular displacement occurs. With the present invention, the apparatus, when using a propeller having a diameter of about 20 feet, is capable of generating about 20 horsepower, and accordingly, the torque forces between the ring and pinion gears are quite large, with the result that the propeller or ring gear tends to "walk" or precess around the pinion gear, thus effecting a misalignment or improper angle of attack of the propeller relative to the wind direction. The offset as shown in FIG. 3 effectively and efficiently solves this problem, since the wind force on the large propeller imparts a moment or torque in a direction opposite that of the torque created between the ring and pinion gears, with the result that the tendency of the ring gear to walk around the pinion gear is offset or balanced. Further, on propellers of the size contemplated by the present invention, there is a problem of flutter of the propeller tips during rapid pitch changes, with the result that the propeller blades are destroyed. This is apparent when it is considered that at the higher wind velocities the propeller tips are traveling well over 150 miles per hour, and during a rapid pitch change, the air foil effect is disrupted, causing flutter or hunting of the propeller tips. The snubbers 64 on the spring assemblies 27 according to the invention effectively solve this problem.
A modified wind electric plant 10' is illustrated in FIGS. 9 and 10, and is substantially the same as previously described, except that a drive shaft means includes a short, splined stub shaft 87 extending downwardly from the hypoid bevel gear 16 through the case extension 14a, and rotatably supported at its upper end by a bearing 88 and at its lower end by a bearing 89. The splined end 90 of the stub shaft projects downwardly below the lower end of the case extension 14a, and is received in a mating, grooved socket 91 on the upper end of drive shaft 15'. As seen in FIG. 10, the extension 14a has a shoulder 92 thereon which engages the upper end of mast pipe 12, to support the case 14 as shown. This splined connection enables the stub shaft 87 and drive shaft 15' to be separated from one another for service on the respective associated parts without requiring disassembly of all of the elements.
Noise reducing and vibration damping means 93 and 94 are engaged between the mast pipe 12 and tower T. The damping means comprises identical, interchangeable, tubular, frusto-conically shaped cast spacers 95 and 96 at the upper and lower ends, respectively, of the mast pipe 12, each having a cylindrical bore therethrough and a conical outer surface, with suitable resilient means 97 and 98, such as rubber or the like, carried thereby and supporting the spacers in spaced relation to the complemental support surfaces 99 and 100 on the cap C and plate 11, respectively. A bearing 101 is engaged between the mast pipe 12 and spacer 96 of lower damping means 94, and a suitable clamp 102 is secured on the mast pipe and engaged against the bearing 101 to hold the bearing 101 and damping means 94 securely engaged.
In one construction of the invention, the ring gear has a diameter of about 15 inches and there is a 6:1 ratio between the ring gear and hypoid bevel gear.
Also, in the form of the invention illustrated in FIGS. 9 and 10, the weather shields 47' and 48' are generally conically shaped and are made of aluminum, or other suitable material.
In FIGS. 11 and 12, a further modification of the wind electric plant is indicated generally at 10", and in this form of the invention the gear means and gear case and the like are subtantially similar to that illustrated and described with reference to FIGS. 9 and 10, except that an extended pinion shaft 103 projects upwardly through the gear case and the pinion gear or hypoid bevel gear 16' is engaged with the ring gear 22 adjacent the upper portion thereof. The upper end of pinion shaft 103 is supported in a bearing means 104 and a bearing cap 105 is secured on the cover 23 of gear case 14 for supporting the bearing means 104.
In connection with this form of the invention, there are some applications for wind electric plants in cold climates, and in such uses, the oil or lubricating fluid used in the gear case becomes quite stiff and, therefore, relatively large frictional drag is encountered upon movement of the gears in the cold lubricating fluid. The largest frictional drag is encountered by the pinion or hypoid bevel gear 16', since it rotates at a much higher speed than the ring gear. In fact, movement of the ring gear does not present a very great problem, since it moves relatively slowly. The ring gear carries ample lubricant with it to the pinion gear to lubricate the same, even through it is positioned above the lubricating fluid, as illustrated in these figures. Further, it should be noted in these figures, and particularly in FIG. 12, that the pinion gear and the pinion shaft are located to the right of the axis of the propeller shaft 17. This arrangement would be utilized, for example, in the event the propeller and ring gear are required to rotate counterclockwise for driving various equipment, and the torque forces between the ring gear and pinion gear are then balanced by the wind forces on the propeller.
A still further modification of wind electric plants is indicated generally at 10''' in FIG. 13, and this form of the invention is substantially identical with that illustrated and described in relation to FIGS. 11 and 12, except that the axis of the extended pinion shaft 103' is positioned to the left of the ring gear shaft 17 when viewed from the rear, as in FIG. 13, and the hypoid bevel gear 16" engages the ring gear near the top thereof, as before, and for substantially the same reasons. However, this form of the invention is intended for applications in which the propeller and ring gear are required to rotate in a clockwise direction in order to obtain balance between the torque forces created between the ring gear and pinion gear and the wind forces acting on the propeller. Further, in this form of the invention the splined shaft is much shorter and the splined end 90' of the pinion shaft is actually positioned closely adjacent the bearing 88 at the bottom of the gear case 14.
In FIG. 14, a further modification of the spring bracket 29" for connecting the inner end of the snubber springs 59 includes a generally cup-shaped, hexagonal bracket 29", having holes through the sides thereof through which the eye bolts 62 extend, and pivot washers 76 identical to those used at the outer ends of the snubber springs are engaged between the nuts 71 and the adjacent inner surfaces of the spring bracket 29'.
Although not illustrated, this same pivot washer structure may be utilized with the double-spring arrangement of FIG. 8, if desired.
As this invention may be embodied in several forms without departing from the spirit or essential characteristics thereof, the present embodiment is, therefore, illustrative and not restrictive, since the scope of the invention is defined by the appended claims rather than by the description preceding them, and all changes that fall within the metes and bounds of the claims or that form their functional as well as conjointly cooperative equivalents are, therefore, intended to be embraced by those claims. | A multiblade, wind-driven, variable pitch propeller is used in a wind electric plant for the generation of electrical power from wind forces, and the propeller is rotatable in a plane at an angle to the tower axis, enabling larger propellers to be used without propeller-tower interference and also reducing the distance between the propeller and gear case. A snubber arrangement is provided on the propeller blade return springs to slow the governor action and prevent abrupt pitch changes and damaging flutter of the blades, and a self-centering, double-acting pivot washer is provided between the propeller blades and the return springs to ensure free pivoting and long life of the spring connecting bolts. Adjustable positive blade stop bolts are engaged directly between the hub and the propeller blades to limit return movement thereof. The propeller hub-return spring connection includes a laterally movable spring bracket which enables the propeller blades to feather in the event one or more return springs is broken or otherwise rendered inoperative. The gear case center, ring gear and axis of propeller rotation are offset laterally from the axis of the tower and pinion gear, to balance torque forces generated at the gears with wind forces on the propeller. | 5 |
REFERENCE TO RELATED APPLICATIONS
This is a continuation of pending International Patent Application PCT/KR2015/002002 filed on Mar. 2, 2015, which designates the United States and claims priority of Korean Patent Application No. 10-2014-0024858 filed on Mar. 3, 2014, Korean Patent Application No. 10-2014-0024859 filed on Mar. 3, 2014, and Korean Patent Application No. 10-2015-0023432 filed on Feb. 16, 2015, the entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to a pillow and, more particularly, to a height-adjustable pillow, the height of which is able to be adjusted.
BACKGROUND OF THE INVENTION
In general, a pillow serves to support the head of a user such that the user can remain in a comfortable position while sleeping, and thus generally has a predetermined height and a suitable cushioning function. Such a pillow includes a pillow body filled with a stuffing and a pillow cover covering the pillow body. The stuffing may be implemented as buckwheat chaff, rice chaff, latex, sponge, cotton, hair, a functional material, or the like.
People sleep in a variety of postures, i.e. people lie on backs, sides, or stomachs. When a person rests with the head supported on a pillow while lying on his or her back, the back of the head, the cervical spine, and the back are substantially in line, such that the user may not be significantly uncomfortable even if the height of the pillow used is relatively low. However, when the person attempts to sleep on the side with the pillow of the same height, the cervical spine becomes curved due to the difference in the height between one shoulder and one side of the face, causing the person to be uncomfortable. In contrast, when a relatively higher pillow is used, the person may feel relatively comfortable when lying on the side. However, when the person lies on his or her back, the head may be raised, whereby discomfort is likely.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made keeping in mind the above problems occurring in the related art, and the present invention is intended to propose a height-adjustable pillow, the height of which is able to be adjusted to a height at which a user can feel comfortable.
In order to achieve the above object, according to one aspect of the present invention, a height-adjustable pillow may include: a lower member; an upper member disposed on the lower member, the upper member being displaceable up and down with respect to the lower member; and a lifting unit adjusting a height of the upper member by displacing the upper member.
The lifting unit may include: a pair of driving shafts horizontally extending through the lower member; rotary gears disposed on the pair of driving shafts, a rotary gear on one of the driving shafts being meshed with a corresponding rotary gear on the other of the driving shafts; and lifting members disposed on the pair of driving shafts, wherein the lifting members lie in horizontal positions or are erected to vertical positions in response to rotation of the driving shafts to move the lifting members up and down.
One of the driving shafts may include a ratchet and a handle disposed thereon. The height-adjustable pillow may further include a stopper limiting free rotation of the ratchet to maintain the pair of driving shafts in a fixed position.
The stopper may be disposed on a support shaft horizontally extending through the base, and may be meshed with or unmeshed from the ratchet in response to a longitudinal movement of the support shaft. An elastic spring may be disposed between the stopper and the lower member to surround the support shaft, so that the support shaft is placed in a set position.
The lifting unit may include: a driving shaft horizontally extending through the lower member; bevel gears disposed on a front end of the driving shaft to convert longitudinal rotation of the driving shaft into lateral rotation; a driving gear section rotating in a lateral direction in concert with the bevel gears; a plurality of driven gear sections rotating in a lateral direction in concert with the driving gear section; and lifting portions disposed on top surfaces of the driven gear sections, each of the lifting portions including a plurality of step portions having different heights.
The plurality of step portions of each of the lifting portions may be formed in a stepwise manner with different heights, with slopes alternating with the step portions.
The upper member may have a plurality of contact members to be seated on corresponding step portions having same heights among the step portions of the lifting portions, so that the plurality of contact members are displaced up and down in response to rotation of the lifting portions.
The lifting unit may include: a rotary member provided on a surface of one of the lower member and the upper member that faces the other of the lower member and the upper member such that the rotary member is rotatable about a vertical axis, the rotary member including a slope upwardly inclined in one direction along a circumference thereof about the axis and a plurality of holding step portions formed on the slope to continuously extend along a length of the slope such that the plurality of holding step portions are positioned at different heights; and a contact member provided one the other one of the lower member and the upper member such that the contact member is able to come into contact with one of the plurality of holding step portions depending on an angle of rotation of the rotary member. Each of the plurality of holding step portions includes a stepped surface and a connecting surface, the stepped surfaces of the plurality of holding step portions are arranged at predetermined distances in the length of the slope such that the stepped surfaces are spaced apart and positioned at different heights from each other, and the connecting surfaces of the plurality of holding step portions are formed as inclined surfaces connecting the stepped surfaces having different heights, respectively, such that the contact member is displaced up and down along one of the connecting surfaces to move to an adjacent one of the stepped surfaces when the rotary member is rotated.
Each of the stepped surfaces may be downwardly inclined in one direction along the circumference about the axis.
The height-adjustable pillow may further include a guide for guiding upward and downward displacement of the upper member. The guide includes a guide pin and a pin-receiving member having a guide hole in which a guide pin is received. The guide pin is provided on one of the upper member and the lower member, and the pin-receiving member is provided on the other of the upper member and the lower member.
The height-adjustable pillow may further include an indicating unit for indicating a height of the upper member determined by the lifting unit. The indicating unit may include: a rack extending vertically downward from the upper member; a pinion meshed with the rack; and an indicating member disposed outside of the lower member to rotate along with the pinion, the indicating member having a height indicating portion.
According to embodiments of the present invention, the height of the pillow is able to be adjusted to a height at which a user can feel comfortable, so that the user is more likely to soundly sleep.
In particular, when the present invention is applied in facilities used by the public, customer satisfaction can be significantly improved, since every user can adjust the heights of a pillow according to his or her preference.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are a perspective view and a front elevation view illustrating a height-adjustable pillow according to a first exemplary embodiment of the present invention;
FIG. 3 is a perspective view illustrating the height-adjustable pillow shown in FIG. 1 , from which the cushion is removed;
FIGS. 4 and 5 are perspective views illustrating the height-adjustable pillow shown in FIG. 3 , from which the cover is removed;
FIGS. 6 and 7 are front cross-sectional views illustrating the height-adjustable pillow according to the first exemplary embodiment of the present invention;
FIGS. 8 and 9 are perspective views illustrating the lift unit used in the height-adjustable pillow according to the first exemplary embodiment of the present invention;
FIGS. 10 and 11 are plan views of FIGS. 4 and 5 , respectively;
FIG. 12 is a front elevation view illustrating a height-adjustable pillow according to a second exemplary embodiment of the present invention;
FIG. 13 is an exploded perspective view illustrating the height-adjustable pillow illustrated in FIG. 12 , from which the cushion is removed;
FIG. 14 is a perspective view illustrating the lifting unit used in the height-adjustable pillow according to the second exemplary embodiment of the present invention;
FIGS. 15 to 17 illustrate the operational relationship of the height-adjustable pillow according to the second exemplary embodiment of the present invention;
FIG. 18 is a front elevation view illustrating a height-adjustable pillow according to a third exemplary embodiment of the present invention;
FIG. 19 is an exploded perspective view illustrating the height-adjustable pillow illustrated in FIG. 18 , from which the cushion is removed;
FIG. 20 is a perspective view illustrating the lifting unit used in the height-adjustable pillow according to the third exemplary embodiment of the present invention;
FIG. 21 is a configuration view illustrating portions of the lifting unit illustrated in FIG. 20 ; and
FIG. 22 is a perspective view illustrating the height adjusting unit used in the height-adjustable pillow according to the third exemplary embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.
First Embodiment
A height-adjustable pillow according to a first exemplary embodiment of the present invention is illustrated in FIGS. 1 to 11 .
As illustrated in FIGS. 1 to 5 , the height-adjustable pillow according to the first exemplary embodiment of the present invention includes a base 20 , a cover 30 , and a lifting unit 100 . The base 20 is a lower member in the shape of a box with the top surface thereof being open. The cover 30 is an upper member seated on the base 20 such that the cover 30 can be displaced up and down. The lifting unit 100 displaces the cover 30 up and down with respect to the base 20 . A cushion 40 is seated on the cover 30 to support the head. The cushion 40 is displaced up and down together with the cover 30 in response to the operation of the lifting unit 100 .
As illustrated in FIGS. 4 to 11 , the lifting unit 100 includes a pair of driving shafts 110 ( 112 , 114 ) extending through the base 20 from the front end to the rear end (extending from the front to the rear), rotary gears 120 disposed on the pair of driving shafts 110 at predetermined distances, and lifting members 130 disposed on the pair of driving shafts 110 at predetermined distances.
The rotary gears 120 disposed on the first driving shaft 112 of the pair of driving shafts 110 mesh with the rotary gears 120 disposed on the second driving shaft 114 of the pair of driving shafts 110 .
The lifting members 130 extend in one direction to be substantially elliptical, respectively having one end disposed on the first driving shaft 112 or the second driving shaft 114 . That is, the lifting members 130 are disposed eccentrically. The lifting members 130 are disposed on the pair of driving shafts 110 such that the lifting members on one of the pair of driving shafts 110 oppose the lifting members on the other of the pair of driving shafts 110 . Thus, the lifting members 130 remain in horizontal positions to be in parallel to each other or are rotated to vertical positions to be in parallel to each other. The detailed operational relationship will be described later.
A handle 140 is disposed on the front or rear end of one driving shaft of the pair of driving shafts 110 , and ratchets 150 inclined in one direction are disposed on one driving shaft of the pair of driving shafts 110 on which the handle 140 is disposed. The plurality of ratchets 150 are provided in a number equal to the number of the lifting members 130 and are configured such that each of the ratchets 150 is in close contact with the corresponding lifting member 130 . However, the number of the ratchets 150 is not limited to a specific number.
In the first embodiment of the present invention, for the sake of convenience, it will be described that the handle 140 is disposed on the front end of the first driving shaft 112 and the plurality of ratchets 150 are disposed on the first shaft 112 .
Stoppers 160 are disposed in the inner space of the base 20 to engage with the ratchets 150 and maintain the ratchets 150 in fixed positions when the ratchets 150 are rotated. The stoppers 160 are disposed on a support shaft 162 extending through the base 20 . Each of the stoppers 160 has an elastic member 160 a extending from one portion thereof to maintain the fixed position. This imparts elasticity to the stopper 160 such that the stopper 160 rotates together with the support shaft 162 to a predetermined angle when external force having a predetermined intensity is applied thereto and then returns to the original position.
An elastic spring 164 surrounding the support shaft 162 is disposed between the front-most stopper of the stoppers 160 disposed on the support shaft 162 and the inner surface of the front end of the base 20 . In addition, a lever 170 is disposed on the front end of the support shaft 162 to be exposed externally. The support shaft 162 moves in the front or back direction as the elastic spring 164 is compressed or restored in response to the lever 170 being pulled or the distal end of the support shaft 162 being pushed.
In addition, as illustrated in FIGS. 10 and 11 , the stoppers 160 are positioned on the same horizontal line as the ratchets 150 due to the tension of the elastic spring 164 to remain engaged with the ratchets 150 . In addition, when the rear end of the support shaft 162 is pushed forward or the lever 170 is pulled, the support shaft 162 is displaced forward along with the elastic spring 164 being compressed, so that the stoppers 160 disposed on the support shaft 162 are also displaced forward, thereby moving away from the same horizontal line as the ratchets 150 . When force of pushing the support shaft 162 or pulling the lever 170 in the position is released, the support shaft 162 returns to the original position due to the restoring force of the elastic spring 162 , whereby the stoppers 160 engage with the ratchets 150 , as illustrated in FIG. 10 .
For reference, the lifting members 130 disposed on the first driving shaft 112 have recesses 132 having a predetermined size such that the lifting members 130 in the horizontal position avoid interfering with the support shaft 162 .
Seating portions 24 are formed on the inner surfaces of both walls of the base 20 , the cover 30 is seated on the seating portions 24 , and the cushion 40 is seated on the cover 30 .
Thus, in the position in which the lifting members 130 are horizontal as in FIG. 6 , the cover 30 is seated on the seating portions of the base 20 . When the lifting members 130 are rotated in the vertical direction as illustrated in FIG. 7 , the cover 30 is displaced upwards from the seating portions 24 of the base 20 by the lifting members 130 .
For reference, guide projections 22 for guiding the lifting of the cover 30 in the vertical direction extend on the surfaces of both walls of the base 20 , and prevention projections 32 for preventing the cushion 40 from derailing extend on the surfaces of both walls of the cover 30 .
The operational relationship of the height-adjustable pillow according to the first exemplary embodiment of the present invention will be described as follows:
First, as illustrated in FIGS. 4 and 6 , in the position in which the lifting members 130 are seated on the seating portions of the base 20 and are in the horizontal positions, the height of the pillow remains in the lowest position.
In this position, a user may rotate the handle 140 disposed on one end of one of the pair of driving shafts 110 in one direction to raise the height of the pillow. That is, as illustrated in FIG. 2 , FIG. 5 , and FIG. 7 , when the handle 140 is rotated in one direction, the first driving shaft 112 on which the handle 140 is disposed rotates along with the handle 140 , so that the ratchets 150 disposed on the first driving shaft 112 rotate in one direction on the stoppers 160 . For example, when the handle 140 disposed on one end of the first driving shaft 112 is rotated to the right, the ratchets 150 disposed on the first driving shaft 112 responsively rotate to the right while clicking with the stoppers 160 .
In this case, the elasticity of the stoppers 160 acts when the elastic members 160 a are slightly pressed, allowing the ratchets 150 to rotate in one direction. Here, since the first driving shaft 112 is also rotated to the right, the lifting members 130 are also rotated together with the rotary gears 120 , whereby the lifting members 130 are rotated from the horizontal positions to the vertical positions.
Since the rotary gears 120 of the first driving shaft 112 are meshed with the rotary gears 120 of the second driving shafts 1114 , when the first driving shaft 112 rotates to the right, the second driving shaft 114 rotates to the left, the opposite direction. This consequently rotates the lifting members 130 disposed on the second driving shaft 114 from the horizontal positions to the vertical positions in the direction opposite to the direction in which the lifting members 130 disposed on the first driving shaft 112 are rotated.
As the lifting members 130 on both sides are vertically rotated as described above, the lifting members 130 displace the cover 30 upwards, so that the cushion 40 seated on the cover 30 is displaced upwards, thereby raising the height of the pillow.
In this position, when the head is placed on the cushion 40 so that load is applied to the cushion 40 and the cover 30 , the ratchets 150 remain in the fixed positions held by the stoppers 160 . This consequently prevents the pair of driving shafts 110 from rotating in the opposite direction, whereby the height of the cushion 40 is maintained.
Thus, the user can gradually raise the height of the cushion 40 to a desirable height using one-way rotation of the handle 140 .
In the case of attempting to lower the height of the cushion 40 from the position in which the height of the cushion 40 has been raised as described above, the ratchets 150 and the stoppers 160 are unfixed, and then the handle 140 is rotated to the left, the opposite direction. That is, as illustrated in FIGS. 10 and 11 , when the rear end of the support shaft 162 is pushed forwards or the lever 170 disposed on the front end of the support shaft 162 is pulled, the stopper disposed on the front end of the support shaft 162 is displaced a predetermined distance in the longitudinal direction while compressing the elastic spring 164 . Consequently, the stoppers 160 are moved away from the same horizontal line as the ratchets 150 , whereby the ratchets 150 are released to rotate to the left, in the opposite direction.
Thus, when the handle 140 is rotated to the left in this position, the first driving shaft 112 and the rotary gears 120 are also rotated to the left, and at the same time, the lifting members 130 are rotated from the vertical positions to the horizontal positions. At this time, the second driving shaft 114 and the rotary gears 120 and the lifting members 130 disposed on the second driving shaft 114 are also rotated to the right.
Responsively, the cover 30 is slowly displaced downwards along with the lifting members 130 that rotate horizontally. When the downward displacement of the cover 30 is finished, the support shaft 162 is released from being pressed or the lever 170 is released from being pulled.
When the support shaft 162 is released from being pressed or pulled, the support shaft 162 is displaced to the original position in the longitudinal direction due to the restoring force of the elastic spring 164 . In other words, the stoppers 160 are positioned on the same line as the ratchets 150 and remain engaged with the ratchets 150 . In this position, it is possible to displace the cover 30 and the cushion 40 upwards again by rotating the handle 140 .
For reference, in the first embodiment of the present invention, the ratchets 150 and the handles 140 have been described as being disposed on the first driving shaft 112 of the pair of driving shafts 110 . Alternatively, the ratchets 150 and the handles 140 may be disposed on the second driving shaft 114 . In this case, the support shaft 162 on which the stoppers 160 are disposed may be disposed to correspond to a portion on which the second driving shaft 114 is positioned.
Second Embodiment
A height-adjustable pillow according to a second exemplary embodiment of the present invention is illustrated in FIGS. 12 to 17 .
As illustrated in FIGS. 12 and 13 , the height-adjustable pillow according to the second exemplary embodiment of the present invention includes a base 20 A, a cover 30 A, and a lifting unit 200 . The base 20 A is a lower member in the shape of a box with the top surface thereof being open. The cover 30 A is an upper member seated on the base 20 A such that the cover 30 A can be displaced up and down. The lifting unit 200 displaces the cover 30 A up and down with respect to the base 20 A. A cushion 40 A is seated on the cover 30 A to support the head. The cushion 40 A is displaced up and down together with the cover 30 A in response to the operation of the lifting unit 200 .
As illustrated in FIGS. 13 and 14 , the lifting unit 200 includes a driving shaft 220 extending through one portion of the base 20 A, a pinion gear (or driving bevel gear) 222 disposed on the distal end of the driving shaft 220 , a ring gear (or driven bevel gear) 224 meshed with the pinion gear 222 , a driving gear section (or driving spur gear) 226 rotating along with the ring gear 224 , and a plurality of driven gear sections (or driven spur gears) 230 meshed and in concert with the driving gear section 226 .
The pinion gear 222 disposed on the distal end of the driving shaft 220 and the ring gear 224 meshed with the pinion gear 222 form bevel gears to convert forward rotation of the driving shaft 220 into lateral rotation of the driving gear section 226 . A handle 210 is disposed on the front end of the driving shaft 220 to be exposed externally from the base 20 A. When the handle 210 is rotated, the driving shaft 220 is rotated, so that the bevel gears of the pinion gear 222 and the ring gear 224 are rotated. Consequently, the driving gear section 226 rotates, so that the drive gears sections 230 are responsively rotated. Lifting portions 234 are formed on the upper portions of the driven gears sections 230 . Each of the lifting portions 234 is configured such that the height thereof changes in a stepwise manner along the circumference thereof.
The structure of the lifting portions 234 is illustrated in FIGS. 14 to 17 . Each of the lifting portions 234 includes a first step portion A having a lowest height, a second step portion B with an upwardly-inclined first slope a formed between the first step portion A and the second step portion B, a third step portion C with an upwardly-inclined second slope b formed between the second step portion B and the third step portion C, a fourth step portion D with an upwardly-inclined third slope c being formed between the third step portion and the fourth step portion D, a fifth step portion E with an upwardly-inclined fourth slope c formed between the fourth step portion D and the fifth step portion E, a sixth step portion F with an upwardly-inclined fifth slope d formed between the fifth step portion E and the sixth step portion F, and a downwardly-inclined sixth slope f formed between the sixth step portion F and the first step portion A. In the second embodiment of the present invention, each of the lifting portions 234 has been described as having a stepped structure of a total six steps including the first step portion A to the sixth step portions F. However, each of the lifting portions 234 may have any stepped structure including two or more steps. The first step A to the sixth step F are disposed at equal distances from each other and are arranged radially around the driving gear section 226 .
Contact members 32 A are formed on the bottom surface of the cover 30 A to be seated on the lifting portions 234 of the driven gears sections 230 , respectively. Thus, as the driven gears sections 230 are rotated, the contact members 32 A are positioned on the first step A to the sixth step F to be moved up and down. This will be described in detail later.
One or more guide pins 34 A are formed on the bottom surface of the cover 30 A and pin-receiving members 22 A for guiding upward-downward movement of the guide pins 34 A are formed on the base 20 A in order to ensure that the contact members 32 A are moved up and down in the vertical direction without being laterally derailed when the contact members 32 A are moved up and down along with the rotation of the lifting portions 234 of driven gears sections 230 . Each of the pin-receiving members 22 A has a guide hole 24 A allowing the corresponding guide pin 34 A received therein to move up and down. Alternatively, pin-receiving members respectively having a guide hole may be formed on the cover 30 A, and guide pins may be formed on the base 20 A.
The operational relationship of the height-adjustable pillow according to the second exemplary embodiment of the present invention will be described as follows:
In the position in which the lifting unit 200 is disposed in the inner space of the base 20 A and the cover 30 A having the cushion 40 A placed thereon is seated on the lifting unit 200 , when the contact members 32 A are positioned on the first step portions A of the driven gears sections 230 as illustrated in FIG. 15 , the cover 30 A and the cushion 40 A remain in the lowest positions.
In this position, when the user rotates the handle in one direction as an attempt to raise the height of the pillow, the driving shaft 220 on which the handle 210 is disposed is rotated, so that the bevel gears consisting of the pinion gear 222 and the ring gear 224 rotate responsively.
Thus, the driving gear section 226 on which the ring gear 224 of the bevel gears is seated is rotated in one direction, so that the plurality of driven gears sections 230 meshed with the driving gear section 226 are also rotated in one direction. That is, since teeth of the driving gear section 226 are meshed with teeth 232 of the driven gears sections 230 , the driven gears sections 230 are rotated along with the rotation of the driving gear section 226 .
As the driven gears sections 230 are rotated as described above, the lifting portions 234 formed on the top portions of the driven gears sections 230 are also rotated, so that the contact members 32 A are moved along the slopes to be positioned on the next higher step portions, thereby displacing the cover 30 A upwards.
For example, as illustrated in FIG. 16 , the driving shaft 220 , the bevel gears, and the driving gear section 226 rotate in response to the rotation of the handle 210 . This leads to the rotation of the driven gears sections 230 , so that the lifting portions 234 are also rotated. When the third steps C are positioned on the bottoms of the contact members 32 A, the cover 30 A and the cushion 40 A are moved upwards to a predetermined height. In this case, the contact members 32 A are seated on the third step portions C after having moved along the first slopes a, the second step portions B, and the second slopes b.
When the handle 210 is rotated further, as illustrated in FIG. 17 , the contact members 32 A are seated on the sixth step portions F after having moved along the third slopes c, the fourth step portions D, the fourth slopes d, and the fifth step portions E, and the fifth slopes e, in response to the rotation of the driving shaft 220 , the bevel gears, the driving gear section 226 , and the driven gears sections 230 .
In the position in which the cover 30 A and the cushion 40 A have been moved to the height positions as described above, when the handle 20 A is rotated further, the contact members 32 A move downwards along the sixth slopes f in response to the rotation of the driving shaft 220 , the bevel gears, the driving gear section 226 , and the driven gears sections 230 to be seated on the first step portions A. Consequently, the cover 30 A and the cushion 40 A are in the lowest positions, as illustrated in FIG. 15 .
For reference, the second embodiment of the present invention has described that the heights of the cover 30 A and the cushion 40 A are raised as the contact members 32 A moved from the lowest step portions to the higher step portions of the lifting portions 234 in response to the handle 210 being rotated. Alternatively, the second embodiment of the present invention may be configured such that the heights of the cover 30 A and the cushion 40 A are lowered as the contact members 32 A move from the higher step portions to the lower step portions of the lifting portions 234 in response to the handle 210 being rotated in the opposite direction.
In addition, each of the lifting portions 234 formed on the top portions of the driven gears sections 230 as illustrated in FIG. 14 may have projections (not shown) on boundaries between the step portions A to F and the slopes a to f, each of the projections protruding a predetermined height from the corresponding step portion, such that the contact members 32 A cannot move from a higher step portion to a lower step portion of the lifting portion 234 along the slopes a to f of the lifting portion 234 unless external force having a predetermined intensity is applied.
Third Embodiment
A height-adjustable pillow according to a third exemplary embodiment of the present invention is illustrated in FIGS. 18 to 22 .
As illustrated in FIGS. 18 and 19 , the height-adjustable pillow according to the third exemplary embodiment of the present invention includes a base 20 B and a cover 30 B. The base 20 B is a lower member in the shape of a box with at least a portion of the top surface thereof being open. The cover 30 B is an upper member seated on the base 20 B such that the cover 30 B can be displaced linearly up and down. The base 20 B and the cover 30 B form a pillow body. The height-adjustable pillow according to the third exemplary embodiment further includes a lifting unit 300 displacing the cover 30 B up and down with respect to the base 20 B to adjust the height of the cover 30 B. A cushion 40 A is provided on the cover 30 to elastically support the head. Thus, the cushion 40 A is displaced up and down together with and in the same direction as the cover 30 B in response to the operation of the lifting unit 300 .
As illustrated in FIGS. 19 and 20 , the lifting unit 300 includes a driving shaft 220 extending through a wall (e.g. a front wall) of the base 20 B. The driving shaft 220 is arranged horizontally to be rotatable. The lifting unit 300 further includes a driving bevel gear 330 disposed on the driving shaft 310 in the inner space of the base 20 B, a driven bevel gear 340 meshed with the driving bevel gear 330 , a driving spur gear 350 disposed coaxially with the driven bevel gear 340 , and a single or plurality of driven spur gears 360 meshed with the driving spur gear 350 . A handle 210 is disposed on the driving shaft 310 outside of the base 20 B. The driving spur gear 350 is disposed on the bottom of the base 20 B. The driven spur gears 360 are provided in a plural number. The driven spur gears 360 are arranged around the driving spur gear 350 and are mounted on the bottom of the base 20 B. The driven bevel gear 340 is disposed on the driving spur gear 350 .
When the handle 320 is rotated, the driving bevel gear 330 is rotated along with and in the same direction as the driving shaft 310 . The driven bevel gear 340 and the driving spur gear 350 are simultaneously rotated about the axis extending in the vertical direction, and the driven spur gears 360 are also driven about the top-bottom axis.
The configuration of the height-adjustable pillow according to the third exemplary embodiment as described above is substantially identical or similar to the configuration according to the second embodiment.
As illustrated in FIGS. 20 and 21 , the lifting unit 300 further includes rotary members 370 disposed on the driven spur gears 360 to rotate along with the driven spur gears 360 , respectively, and contact members 380 protruding from the cover 30 in the direction of the rotary members 370 . Here, the contact members 380 function similarly to the contact members 32 A according to the second embodiment.
Each of the rotary members 370 has a slope 372 on the top portion thereof, the slope 372 being upwardly inclined in one direction (i.e. counterclockwise in the drawing) along the circumference about the axis of the underlying driven spur gear 360 . Holding step portions 374 are formed on the slope 372 , continuously along the length of the slope 372 , such that the holding step portions 374 are positioned at different heights.
The distal end of each of the contact members 380 is in contact with one of the holding step portions 374 , depending on the angle of rotation of the rotary member 370 .
Each of the holding step portions 374 includes a stepped surface 376 and a connecting surface 378 . In each of the slopes 732 , the stepped surfaces 376 are arranged at predetermined distances along the length of the slope 372 such that the stepped surfaces 376 are spaced apart and positioned at different heights from each other. The connecting surfaces 378 are formed as inclined surfaces connecting the stepped surfaces 376 that are at different heights. With this configuration, when the rotary member 370 is rotated, the contact member 380 is moved up or down while coming into contact with the stepped surfaces from one to an adjacent one.
The stepped surfaces 376 are inclined downwardly in one direction along the circumference about the axis of the underlying driven spur gear 360 in order to prevent the contact member 380 from being unintentionally moved along with the connecting surfaces 378 .
Although not specifically illustrated, the height-adjustable pillow according to the third exemplary embodiment of the present invention may include a guide for guiding upward and downward displacement of the cover 30 B. The guide may include one or more guide pins (not shown) protruding downward from the cover 30 B and pin-receiving members 50 B formed on the base 20 B, each of the pin-receiving members 50 B having a guide hole in which the corresponding guide pin is received. Alternatively, the positions of the guide pins may be exchanged with the positions of the pin-receiving members 50 B. Here, the functions of the guide pins and the pin-receiving members 50 B are substantially identical or similar to the functions of the guide pins 34 A and the pin-receiving members 22 A according to the second embodiment.
The operational relationship of the height-adjustable pillow according to the third exemplary embodiment of the present invention will be described as follows:
When the contact members 380 are positioned on the stepped surfaces 376 of the holding step portions 374 , the cover 30 B remains in the lowest position.
In this position, when the handle 320 is rotated counterclockwise in the drawing of FIG. 20 , the driving bevel gear 330 , the driven bevel gear 340 , the driving spur gear 350 , and the driven spur gears 360 are rotated together with the driving shaft 310 . At the same time, the driven spur gears 360 are rotated clockwise in the drawing of FIG. 20 . Then, the contact members 380 are moved upwards along the inclined connecting surfaces 378 of the lowest holding step portions 374 to be positioned on the stepped surfaces 376 of the higher step portions next to the lowest holding step portions 374 , so that the cover 30 B is set to a one-step higher height.
When the handle 320 is rotated continuously in the same direction, the height of the cover 30 B is continuously raised. In contrast, when the handle 320 is rotated in the opposite direction, the contact members 380 are positioned on the stepped surfaces of the lower holding step portions, so that the height of the cover 30 B is lowered.
Reference numeral 400 in FIG. 22 indicates an indicating unit that indicates the height of the cover 30 B that has been moved up or down by the lifting unit 300 .
Referring to FIGS. 18 and 19 together with FIG. 22 , the indicating unit 400 includes a rack 410 extending downward from the cover 30 B to be positioned within the base 20 B, a pinion 420 disposed within the base 20 B to be meshed with the rack 410 , an operating gear 430 disposed within the base 20 B to be meshed with the pinion 420 , and an indicating member 440 disposed outside of the base 20 B. The indicating member 440 is mounted on the shaft of the operating gear 430 to rotate along with the operating gear, and has a height indicating portion. Although not illustrated, a pointer may be provided in a portion of the base 20 B adjacent to the indicating portion, such that the pointer represents the height indicated by the indicating portion of the indicating member 440 .
In the indicating unit 400 , as the cover 30 B is displaced up and down, the rack 410 is moved up and down along with and in the same direction as the cover 30 B, thus rotating the pinion 420 and the operating gear 430 . Consequently, the indicating member 440 is rotated, thereby indicating the height of the cover 30 B that has been displaced up and down. Here, the user can adjust the height of the cover 30 B while visually recognizing the height of the cover 30 B that has been displaced up and down through the height indicating portion.
Although the present invention has been described for illustrative purposes, the present invention is not limited to the disclosed embodiments and accompanying drawings. Those skilled in the art will appreciate that various modifications are possible without departing from the scope and spirit of the present invention as disclosed in the accompanying claims. In addition, technical concepts described with respect to the embodiments of the present invention may be carried out alone or two or more thereof may be combined. | The present invention provides a height-adjustable pillow comprising: a lower member; an upper member which is disposed above the lower member, in such a way as to be able to move vertically relative to the lower member; and a raising and lowering device for adjusting the height of the upper member by moving the upper member. | 0 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the operation of drive units having an operating range that is not permissible in the steady state, in particular internal combustion engines and operation thereof, operating modes using injection blank-outs being usable in particular.
[0003] 2. Description of Related Art
[0004] Modern internal combustion engines have an air supply system to control the air mass flow, which is supplied to the cylinders of the internal combustion engine. A throttle valve which regulates the air flow into the intake manifold is in most cases situated in the air supply system. In modern internal combustion engines, the throttle valve is adjusted electrically. The final rate of adjustment of the throttle valve as well as dynamic filling effects in the intake manifold do not allow a highly dynamic adjustment of a specified air mass flow. Therefore, rapid adjustments of the torque supplied by the internal combustion engine cannot be made using this adjustment mechanism.
[0005] Therefore, during operation of the internal combustion engine, a lead desired torque is provided, which may provide an increased air filling in the cylinders in the static operating range, so that an increased torque may be retrieved rapidly by adjusting the ignition angle. Therefore, an intervention in the ignition angle may be utilized to achieve a rapid change in torque of the internal combustion engine.
[0006] A reduction in the torque of the engine based on a lower desired torque specification is achieved with the help of a retard adjustment of the ignition angle with respect to a basic ignition angle, causing a reduced efficiency of the internal combustion engine, which then has a negative effect on fuel consumption. The actual torque of the internal combustion engine is thereby lowered in comparison with the basic torque and follows the specified desired torque (which is declining). A reduction in torque via a retard adjustment of the ignition angle is possible up to the minimum basic torque, which is defined by the combustibility limit as well as by component safety limits and depends on the prevailing basic torque (i.e., the prevailing filling), among other things.
[0007] A further reduction in torque with a corresponding low desired torque is then achievable only through an injection blank-out of individual cylinders. However, injection blank-outs are associated with higher exhaust gas emissions, increased uneven running of the internal combustion engine and noise problems. Injection blank-out operation is technically possible in a steady state but should only be done temporarily. Quasi-steady-state operation, including injection blank-out of individual cylinders, should therefore be avoided.
[0008] The actual torque of the internal combustion engine may be reduced by injection blank-out of all cylinders down to the minimal torque corresponding to the loss torque of the internal combustion engine. This is a case of overrun fuel cutoff, in which the disadvantages of operating with an injection blank-out of only some of the cylinders no longer exist. The overrun fuel cutoff is therefore adjustable over a longer period of time and thus in a quasi-steady state. This yields torque ranges for the desired torque which may be utilized during normal operation in a quasi-steady state:
a first torque range, which corresponds to the torque range between the basic torque and the minimal basic torque, depending on the prevailing filling; and a second torque range, which is defined by the overrun fuel cutoff of the internal combustion engine and corresponds to a minimal engine torque representing the loss torque of the internal combustion engine.
[0011] In between there is a torque range for the desired torque which should not be utilized, i.e., is not permitted, in a quasi-steady state during normal operation because of the disadvantages described above with respect to uneven running and exhaust gas emissions. However, depending on the desired torque requested, this may result in a rapid change between the first and second torque ranges to supply a torque which is in the torque range between the first and second torque ranges. Such a rapid change results in torque jumps, which may become noticeable as uncomfortable jerking during driving operation.
[0012] Under certain circumstances, the torque range permitted and usable during normal operation is additionally restricted, for example, when only injection operation of all cylinders is permitted for emission reasons because the temperature of the catalytic converter is too low and an injection blank-out of individual cylinders or an overrun fuel cutoff is not permitted.
[0013] In addition, it is possible that operation departs from normal operation during safety-critical interventions or safety interventions, for example, ESP, emergency running, maximum rpm downregulation, monitoring, component protection, speed limit, and the like, and the torque ranges that are not permissible in the steady state during normal operation may also be adjusted for a longer period of time. In addition, interventions of an automatic transmission into the desired torque, for example, during shifting operations, among other things, may necessitate a deviation from normal operation.
[0014] The object of the present invention is to make available a method for operating an internal combustion engine in which there is a provision for permitting only temporarily a torque range which is not usable or is not permissible in a steady state during normal operation, for example, the torque range, which may be achieved only through a cylinder blank-out of individual cylinders, so that during transitions between desired torques occurring in various torque ranges which are permitted in a steady state, there should not be any uncomfortable jumps in the torque supplied by the internal combustion engine during operation of a vehicle.
BRIEF SUMMARY OF THE INVENTION
[0015] According to a first aspect of the present invention, a method is provided for operating an internal combustion engine, which method includes the following steps:
providing a specification variable for triggering the drive unit to supply an output variable; providing a specification of operating point-dependent output variable ranges for the specification variable supplied, in which steady-state operation of the drive unit is permissible, an output variable range that is not permissible in the steady state being defined between the operating point-dependent output variable ranges; if, during a transitional operating mode, a change in the specification variable for the drive unit necessitates traversing of the output variable range that is not permissible in the steady state, triggering the drive unit on the basis of a guided specification variable,
the guided specification variable being determined by guiding the specification variable, so that the period of time during which the drive unit is triggered to supply the guided specification variable within the output variable range that is not permissible in the steady state is limited to a specified maximum period of time.
[0019] One idea of the above method is to limit the period of time during which the drive unit is triggered to supply an output variable in an output variable range that is not permissible in the steady state in that the specification variable is guided during a transitional operating mode between the output variable ranges that are permissible in the steady state.
[0020] It is possible in particular to provide that the specification variable is guided by limiting the specification variable with respect to one or more limiting values to obtain the guided specification variable, so that the limiting value(s) is (are) obtained from one or more specified limiting value curves within a first of the output variable ranges and a second of the output variable ranges.
[0021] One idea of the above method is to ascertain instantaneous limiting values, which are valid for the prevailing operating point and are determined for a specified specification variable, and to ascertain the output variable ranges in which continuous operation of the drive unit is permitted. The instantaneous limiting values are adjusted dynamically in such a way that they only temporarily permit a specification variable, which is within an output variable range that is not permissible in the steady state, for example, to achieve comfortable transitions between the output variable ranges that are permissible in the steady state. For this purpose, the instantaneous limiting values are further adapted dynamically in such a way that no additional jumps (i.e., apart from jumps caused by other factors, for example, the driver's desired torque) in the guided (limited) specification variable are thereby created.
[0022] In the above method, a specification variable in particular which is within the output variable ranges that are permissible in the steady state, may be permitted, i.e., not limited. An immediate response to a change in the driver's desired torque within the output variable range that is permissible in the steady state is thus possible, for example. In addition, rapid traversing of an output variable range that is not permissible in the steady state at a corresponding curve of the specification variable is also permitted. However, traversing the output variable range too slowly is not permitted, as it may cause elevated exhaust gas emissions, increased uneven running of the internal combustion engine and/or emission of too much noise.
[0023] In hybrid vehicles in particular, rapidly traversing the output variable range that is not permissible in the steady state, is enabled when a compensation of a rapidly changing specification variable is possible by one or more electric motors or hydraulic motors. Rapid changes in the total drive power, for example, may thus be prevented, thereby ensuring good driving comfort.
[0024] In addition, the specification variable may be guided by limiting the specification variable with respect to one or more limiting values to obtain the guided specification variable, the limiting value(s) being obtained from one or more specified limiting value curves between a first of the output variable ranges and a second of the output variable ranges.
[0025] In addition, the specification variable may be limited to the first or second output variable range if there is no transitional operating mode.
[0026] According to one specific embodiment, the first and the second output variable ranges may each be defined by a lower output variable range limit and an upper output variable range limit, the upper output variable range limit of the second output variable range being lower than the lower output variable range limit of the first output variable range, the limiting value curve being defined as monotonic and steady between the upper output variable range limit of the second output variable range and the lower output variable range limit of the first output variable range within the specified maximum period of time.
[0027] According to one specific embodiment, the specification variable of a desired torque specification and/or the output variable range may correspond to torque ranges.
[0028] According to one specific embodiment, the first torque range may be defined as the torque range between a minimal basic torque, which indicates the minimal drive torque, suppliable by intervention into the ignition angle at the existing air filling in the cylinders and an optimal basic torque, which indicates the maximal drive torque suppliable by intervention into the ignition angle at the existing air filling in the cylinders and/or the second torque range may represent a minimal torque, which is determined by the torque supplied by the internal combustion engine at the instantaneous operating point during the overrun fuel cutoff.
[0029] Alternatively or additionally, the torque ranges (in particular the first torque range) may be spanned by varying the injected fuel quantity and/or by varying the start of injection and/or by varying the injection pattern and/or by varying the exhaust gas recirculation rate and/or by varying the exhaust gas back-pressure, etc.
[0030] In particular when the transitional operating mode is occurring with a change in the operating point of the internal combustion engine from the first torque range to the second torque range, the desired torque may be limited to an upper limiting value specified by a first limiting value curve if the desired torque is within the torque range that is not permissible in the steady state.
[0031] In particular when the transitional operating mode is occurring with a change in the operating point of the internal combustion engine from the second torque range to the first torque range, the desired torque may be limited to a lower limiting value specified by a second limiting value curve if the desired torque is within the torque range that is not permissible in the steady state.
[0032] In particular when the transitional operating mode is occurring with a change in the operating point of the internal combustion engine from the second torque range to the first torque range, the desired torque may be limited to an upper limiting value specified by a third limiting value curve if the desired torque is within the torque range that is not permissible in the steady state.
[0033] In particular when the transitional operating mode is occurring with a change in the operating point of the internal combustion engine from the first torque range to the second torque range, the desired torque may be limited to a lower limiting value specified by a fourth limiting value curve if the desired torque is within the torque range that is not permissible in the steady state.
[0034] According to one specific embodiment, the desired torque may be limited with respect to one or more limiting values as a function of an operating mode signal indicating whether normal operation or an exceptional operation prevails.
[0035] In the exceptional operating mode in particular, it may be permissible to use a torque range that is not permissible in the steady state for a longer period of time and/or not to take into account additional restrictions if, for example, safety-critical interventions or safety interventions (for example, ESP, emergency running, maximal rpm downregulation, monitoring, component protection, speed limit, and the like) or interventions of an automatic transmission have a higher priority.
[0036] In addition, in a motor system in which an internal combustion engine is operated as a function of a desired torque formed from a driver's desired torque and a torque intervention supplied by a requester, the torque range limits defining the torque ranges that are permissible in the steady state are transmitted to the requester. The requester may thus select optimal operating points for the internal combustion engine and the electric motor and thus optimize a driving strategy, for example, in the case of hybrid vehicles having a degree of freedom in the choice of operating point. If the engine control device and the requester are implemented in different units, communication of the instantaneous torque range limits from the internal combustion engine to the requester may be implemented easily via a bus system, because the dynamics of changes in torque range limits at the prevailing operating point are lower than the dynamics of the internal combustion engine and the requester, so that signal delays in communication are not critical.
[0037] In addition, it is possible to provide for the torque range that is not permissible in the steady state as well as a torque range in which an overrun fuel cutoff operation occurs, for example, not to be permitted at least temporarily in an operating mode because the catalytic converter temperature is too low, for example. For this purpose, a corresponding blocking signal may be generated, which requests a change from one torque range that is permissible in the steady state during normal operation to another torque range that is permissible in the steady state during normal operation, but does not permit, i.e., prevents this change based on the additional restrictions given above.
[0038] In addition, the transitional operating mode may be determined as a function of an intervention signal, the intervention signal indicating the change in operating point of the internal combustion engine which requires traversing the torque range that is not permissible in the steady state.
[0039] According to one specific embodiment, the specification variable may be guided according to a specified time curve. In particular the specified time curve may be such that the guided specification variable reaches the subsequent operating range that is permissible in the steady state when the specified maximum period of time has elapsed.
[0040] According to another aspect, a device for operating an internal combustion engine is provided. The device includes:
a requester for supplying a specification variable for triggering the drive unit to supply an output variable; a specification variable guidance unit for guiding the specification variable; an engine control unit to operate the drive unit so that an output variable of the drive unit is supplied according to the guided specification variable; a guidance unit which is designed
to provide a specification about operating point-dependent output variable ranges for the supplied specification variable, in which a steady-state operation of the drive unit is permissible, an output variable range that is not permissible in the steady state being defined between the operating point-dependent output variable ranges; and to trigger the drive unit on the basis of the guided specification variable when in a transitional operating mode a change in the specification variable for the drive unit necessitates traversing the output variable range that is not permissible in the steady state,
the guided specification variable being determined by guiding the specification variable so that the period of time during which the drive unit is triggered to supply the guided specification variable within the output variable range that is not permissible in the steady state is limited to a specified maximum period of time.
[0047] The requester may correspond in particular to a torque requester, the guidance unit may correspond to a limiting unit and the specification variable guidance unit may correspond to a desired torque limiter.
[0048] According to another aspect, a motor system is provided having the above device and an engine control unit, which triggers a drive unit as a function of the guided specification variable.
[0049] According to another aspect, a computer program is provided which executes the above method when it is executed on a data processing unit.
BRIEF DESCRIPTION OF THE DRAWINGS
[0050] FIG. 1 shows a schematic block diagram of an engine system for implementing a method for avoiding torque ranges that are not permissible in the steady state.
[0051] FIG. 2 shows a signal-time diagram, which indicates the curves of the limiting values for limitation of the desired torque, the limited desired torque and a torque request signal and an operating mode signal.
DETAILED DESCRIPTION OF THE INVENTION
[0052] FIG. 1 shows a schematic diagram of an engine system 1 having an internal combustion engine 2 . Internal combustion engine 2 is triggered via an engine control unit 3 with the help of engine control signals which specify, for example, a position of the throttle valve, a fuel injection quantity to be injected into a cylinder before each combustion process, ignition times for igniting an air/fuel mixture in the cylinder, and the like. To generate the engine control signals, engine control unit 3 receives a lead desired torque trqLeadEng from a torque requester 4 . In addition, torque requester 4 supplies a desired torque, which indicates unlimited desired torque trqDesEng to be supplied by internal combustion engine 2 .
[0053] Unlimited desired torque trqDesEng is supplied to a desired torque limiter 5 , which forwards a limited desired torque trqDesEngLtd to engine control unit 3 . Limiting unit 5 receives as additional input variables information about an upper instantaneous limiting value trqMax and a lower instantaneous limiting value trqMin, defining the range to which the instantaneous unlimited desired torque is to be limited.
[0054] Engine control unit 3 ascertains basic torque Eng_trqBs as well as minimal basic torque Eng_trqBsMin, which respond with a delay when there is a change in the desired torque to lead desired torque trqLeadEng, based on the air path dynamics.
[0055] In addition, engine control unit 3 determines a minimal torque Eng_trqMin, which depends on the instantaneous rpm, the internal combustion engine temperature and additional parameters and corresponds to a loss torque of the internal combustion engine, which occurs when no drive torque is being generated by internal combustion engine 2 . In other words, minimal torque Eng_trqMin represents the torque of internal combustion engine 2 during overrun fuel cutoff operation.
[0056] Basic torque Eng_trqBs, minimal basic torque Eng_trqBsMin and minimal torque Eng_trqMin are supplied to a limiting unit 6 , which determines from them the lower instantaneous limiting value trqMin and upper instantaneous limiting value trqMax and supplies them to desired torque limiter 5 . In addition, lower and upper instantaneous limiting values trqMin, trqMax are also supplied to torque requester 4 , where they are used to initialize a filter, for example, which filters unlimited desired torque trqDesEng. Lower and upper instantaneous limiting values trqMin, trqMax are used to initialize the filter when desired torque trqDesEng, which is to be supplied, encounters one of the limits defined by lower and upper instantaneous limiting values trqMin, trqMax.
[0057] In addition, limiting unit 6 receives limited desired torque trqDesEngLtd from desired torque limiter 5 . Torque requester 4 also supplies an intervention signal bCtOff, indicating a change from injection operation of all cylinders to the overrun fuel cutoff operation or indicating in general the change from a first torque range that is permissible in the steady state during normal operation, i.e., a usable first torque range, to another torque range that is permissible in the steady state during normal operation, i.e., a usable torque range.
[0058] In addition, torque requester 4 supplies an operating mode signal bNorm, with which it is possible to indicate whether the internal combustion engine is to be operated in a normal operation or in an exceptional operating mode. The exceptional operating mode stipulates that the restriction of the torque range that is not permissible in the steady state is to be eliminated, so that all torque ranges may be retrieved by torque requester 4 , also for longer periods of time. Therefore, it may occur, for example, that internal combustion engine 2 is operated with injection blank-out of individual cylinders also for longer periods of time.
[0059] Moreover, it may be provided that the information about basic torque Eng_trqBs and/or minimal basic torque Eng_trqMinBsMin and/or minimal torque Eng_trqMin is also supplied to torque requester 4 , for example, in hybrid vehicles having a degree of freedom in the choice of operating point, i.e., various desired torques may be supplied, depending on the operating point, in order to select optimal operating points for internal combustion engine 2 and/or one or more electric motors or hydraulic motors and thereby optimizing the driving strategy.
[0060] The functioning of limiting unit 6 becomes clear from the signal-time diagram in FIG. 2 . Basic torque Eng_trqBs, minimal basic torque Eng_trqBsMin and minimal torque Eng_trqMin are represented as dashed horizontal lines in the signal-time diagram in FIG. 2 . Basic torque Eng_trqBs and minimal basic torque Eng_trqBsMin depend on the operating point, so they depend in particular on the air filling of the cylinders and the instantaneously adjustable ignition angle values. Minimal torque Eng_trqMin depends primarily on the rpm of internal combustion engine 2 . Between basic torque Eng_trqBs and minimal basic torque Eng_trqBsMin there is a first torque range that is permissible in the steady state. Minimal torque Eng_trqMin in this example determines the second torque range that is permissible in the steady state, which in this case corresponds only to a certain torque, namely the torque of internal combustion engine 2 during overrun fuel cutoff operation. A torque range that is not permissible in the steady state is defined between minimal basic torque Eng_trqBsMin and minimal torque Eng_trqMin.
[0061] Lower instantaneous limiting value trqMin and upper instantaneous limiting value trqMax, to which unlimited desired torque trqDesEng is limited, are represented by solid lines. A single solid line indicates the curve of desired torque trqDesEng. The curve of limited desired torque trqDesEngLtd is represented by the dashed line.
[0062] In addition, intervention signal bCtOff and operating mode signal bNorm are represented as a function of time, so that the corresponding changes in lower and upper instantaneous limiting values trqMin, trqMax are recognizable due to these signals. Since before a point in time T 1 , intervention signal bCtOff having a low level indicates that there is no request to change from injection operation of all cylinders to the overrun fuel cutoff, upper instantaneous limiting value trqMax corresponds to basic torque Eng_trqBs, and lower instantaneous limiting value trqMin corresponds to minimal basic torque Eng_trqBsMin. Desired torque trqDesEng runs briefly below lower instantaneous limiting value trqMin before point in time T 1 , so that desired torque limiter 5 is actively limiting and limited desired torque trqDesEngLtd deviates briefly from supplied desired torque trqDesEng, (see range A) and instead assumes the value of lower instantaneous limiting value trqMin. Therefore, a short-term injection blank-out, which would be carried out by engine control unit 3 at a desired torque trqDesEng below minimal basic torque Eng_trqBsMin, may be avoided.
[0063] At point in time T 1 , torque requester 4 specifies with a change in the level of intervention signal bCtOff a request to change to the overrun fuel cutoff, so that lower instantaneous limiting value trqMin jumps to minimal torque Eng_trqMin.
[0064] At point in time T 2 , limited desired torque trqDesEngLtd reaches minimal basic torque Eng_trqBsMin and thus unlimited desired torque trqDesEng or limited desired torque trqDesEngLtd enters a torque range that is not permissible in the steady state. As a result, upper instantaneous limiting value trqMax jumps to minimal basic torque Eng_trqBsMin (point in time T 2 ) and its time curve proceeds like a ramp in the direction of minimal torque Eng_trqMin. The ramp shape of the time curve is defined and specified.
[0065] Desired torque trqDesEng runs above the ramp-shaped curve of upper instantaneous limiting value trqMax, so that desired torque trqDesEng is limited to the curve of upper instantaneous limiting value trqMax, i.e., limited desired torque trqDesEngLtd runs along upper instantaneous limiting value trqMax and then corresponds to minimal torque Eng_trqMin at trqMax=trqMin=Eng_trqMin as soon as the ramp-shaped curve of upper instantaneous limiting value trqMax has reached the lower instantaneous limiting value. Due to the defined ramp-shaped curve of upper instantaneous limiting value trqMax in the torque range that is not permissible in the steady state between minimal basic torque Eng_trqBsMin and minimal torque Eng_trqMin, this achieves the result that a limited desired torque trqDesEngLtd prevails only temporarily within the torque range that is not permissible in the steady state during normal operation.
[0066] If at point in time T 1 a change to overrun fuel cutoff were to be blocked due to an additional restriction, for example, due to a too low temperature of a catalytic converter, which would result in an internal blockage of overrun fuel cutoff or an injection blank-out of the internal combustion engine, lower instantaneous limiting valve trqMin would still correspond to minimal basic torque Eng_trqBsMin and upper instantaneous limiting valve trqMax would still correspond to basic torque Eng_trqBs.
[0067] At point in time T 3 , torque requester 4 specifies a request to change to injection operation of all cylinders by changing intervention signal bCtOff to a low level. As a result, upper instantaneous limiting value trqMax jumps to basic torque Eng_trqBs, and lower instantaneous limiting value trqMin is guided in a ramp-shaped curve to minimal basic torque Eng_trqBsMin. At point in time T 3 , limited desired torque trqDesEngLtd then jumps to the value of desired torque trqDesEng and, if the value of desired torque trqDesEng falls below the ramp-shaped curve of lower instantaneous limiting value trqMin, then according to the ramp-shaped curve of lower instantaneous limiting value trqMin, it is guided to the value of minimal basic torque Eng_trqBsMin.
[0068] Alternatively, at point in time T 3 , lower instantaneous limiting value trqMin may initially jump to the value of unlimited desired torque trqDesEng and, beginning from there, be guided according to a ramp-shaped curve to minimal basic torque Eng_trqBsMin, so as not to shorten the dwell time in the range that is not permissible in the steady state. This achieves the result that there are no additional jumps in limited desired torque trqDesEngLtd.
[0069] Alternatively, the jump in limited desired torque trqDesEngLtd at point in time T 3 is preventable if, starting at point in time T 3 , upper instantaneous limiting value trqMax proceeds to basic torque Eng_trqBs without any jumps, i.e., again in the form of a ramp. Limited desired torque trqDesEngLtd within the torque range that is not permissible in the steady state during normal operation also occurs only temporarily during the change to injection operation of all cylinders from the overrun fuel cutoff operation.
[0070] The ramp-shaped curves of lower and upper instantaneous limiting values trqMin, trqMax, whose slope is adaptable to the prevailing operating points such as rpm, temperature, and the like, from lower instantaneous limiting value trqMin or upper instantaneous limiting value trqMax during traversing the torque range that is not permissible in the steady state during normal operation are only examples. Other time curves or dependencies of additional parameters are also conceivable. For example, exponential curves or smoothed curves of the upper and lower instantaneous limiting values may also be provided.
[0071] A rapid change in lower instantaneous limiting value trqMin or upper instantaneous limiting value trqMax between minimal torque Eng_trqMin and minimal basic torque Eng_trqBsMin is optimal, for example, with respect to exhaust gas emissions but results in a rapidly changing limited desired torque trqDesEngLtd, which could have a negative effect on driving comfort. Rapid changes are the goal when compensation of the rapidly changing limited desired torque trqDesEngLtd by one or more electric motors or hydraulic motors is possible in hybrid drives. In hybrid vehicles, the curves of lower instantaneous limiting value trqMin and/or of upper instantaneous limiting value trqMax advantageously depend on the operating points of one or more of the electric motors or hydraulic motors or of a vehicle electrical system or a hydraulic power supply.
[0072] At point in time T 4 , torque requester 4 terminates normal operation by changing the level of operating mode signal bNorm to a low level, for example, because a safety-critical ESP intervention of a high priority exists. The instantaneous limiting values are then enabled at trqMin=Eng_trqMin and at trqMax=Eng_trqBs for the entire torque adjustment range of internal combustion engine 2 . Limited desired torque trqDesEngLtd corresponds to desired torque trqDesEng, which is specified by a torque requester of a high priority (for example, an ESP block). Intervention signal bCtOff is of a lower priority than operating mode signal bNorm.
[0073] In the exemplary embodiment shown here, the torque ranges that are permissible in the steady state correspond to the torque range between basic torque Eng_trqBs and minimal basic torque Eng_trqBsMin as well as loss torque Eng_trqMin during overrun fuel cutoff operation of internal combustion engine 2 . Alternatively or additionally, other torque ranges which are usable, i.e., permissible in a steady state, may also be defined; they are separated from one another by a torque range, in which steady-state use during normal operation is not permissible.
[0074] The duration of the ramp-shaped curve, i.e., the period of time during which upper instantaneous limiting value trqMax runs from minimal basic torque Eng_trqBsMin to minimal torque Eng_trqMin, may be between 100 ms and 500 ms, for example as a function of operating parameters of internal combustion engine 2 . The ramp-shaped curve of lower instantaneous limiting value trqMin may have the same absolute value of the gradient of the ramp of the curve of upper instantaneous limiting value trqMax or may have an absolute value of the gradient which is different from that.
[0075] Instead of predefining upper and lower limiting values trqMin, trqMax, the specification variable, i.e., limited desired torque trqDesEngLtd, may be guided through the torque range that is not permissible in the steady state in accordance with a specified time curve. The time curve, which may correspond to a ramp function or some other monotonic function, for example, determines that limited (guided) desired torque trqDesEngLtd does not remain within the torque range that is not permissible in the steady state any longer than a specified maximum period of time. By providing the time curve with which limited (guided) desired torque trqDesEngLtd is guided, an abrupt transition between the torque ranges may be prevented on the one hand, while on the other hand, this also prevents remaining for too long in the torque range that is not permissible in the steady state, which is not desirable.
[0076] The specified maximum duration is selected in such a way that, on the one hand, it prevents the transition between the torque ranges that are permissible in the steady state which would impair driving comfort and, on the other hand, minimizes the period of time during which the torque range that is not permissible in the steady state prevails for the engine protection reasons described above. For example, the maximum period of time should also correspond at least to a period of time in which it is ensured that there is no acceleration and no change in torque during the transition between the torque ranges that are permissible in the steady state, whose absolute value is above a certain specified threshold value. This period of time could thus be defined by the size of the torque range that is not permissible in the steady state divided by the maximum desired change in torque. In traditional vehicles and engine systems, the specified maximum period of time is preferably between 0.1 seconds and 5 seconds, in particular between 0.5 seconds and 2 seconds. | A method for operating an internal combustion engine includes: providing a desired power specification for triggering the drive unit; providing a specification of operating point-dependent power ranges for the supplied desired power specification, in which steady-state operation of the drive unit is permissible, a power range that is not permissible in the steady state being defined between the operating point-dependent power ranges; when a change in the desired power specification for the drive unit in a transitional operating mode necessitates traversing the power range that is not permissible in the steady state, triggering the drive unit on the basis of a specification of a guided desired power, the guided desired power specification being determined by guiding the desired power specification. | 5 |
FIELD OF THE INVENTION
The present invention relates in general to an arrangement for spot illumination. More particularly the present invention relates in general to an arrangement for spot illumination having a tubular reflector with two sections.
BACKGROUND OF THE INVENTION
Colored light is used in many applications where scene setting and atmosphere creation is important. Examples of applications exist inter alia in the fields of theatre lighting, architecture lighting (inter alia for city beautification), shops, hotels, restaurants, hospitals, schools, office spaces. Today this is mostly accomplished by combining white light sources with colored filters in order to obtain desired colors.
As an alternative, systems with multi-colored LEDs can be used. Such systems are attractive because they generate the desired colors without filters. This has an efficiency advantage and, more importantly, colors can be changed by the electronics: there is no need to change filters in order to change color; all colors are directly available by combining inter alia a number LEDs of different prime colors. Having electronically regulated colors allows various automatic programming methods to be used to control the lighting system and the fact that filters are omitted results in easier supply chain (no filters needs to be removed) and color consistency (replaced filter might introduce variation). The market for these systems is quickly growing as LED performance improves.
In multi-channel, high flux LED applications such as e.g. CDM replacement spots and multi-color entertainment spots (for theatre/touring/stage/studio applications) a large number of LEDs may be needed and the LEDs should be packed on a small array in a robust way. The performance of an assembly of individual LED packages, such as Rebels, is often limited. On the other hand dedicated large LED arrays, such as fabricated by the company Enfis, LEDEngine have intrinsically a low yield and they are too expensive for many applications. There is thus a need for a scalable solution than can be manufactured and/or assembled with a high yield and high alignment robustness.
U.S. 60/200,002 disclose a so-called collimating trumpet reflector, which provides excellent color mixing for a LED light source and efficient collimation for inter alia hard edge spot fixtures as used in theatre spots. However, lighting designers may wish to use the same fixture to project an out of focus diaphragm to get a soft edge. Particularly in stage lighting, there is often a need to create a controlled beam of light having sharp edges. This is often realized using a so called hard edge spot luminary (also called a profile lantern or an ellipsoidal profile spot). The hard edge spot luminary may comprise obstructions arranged in the optical path or axis, which obstructions can be projected onto a target surface by a lens or optics of the hard edge spot luminary. These obstructions may comprise shutters or a so called gobo, e.g., a piece of material with patterned holes through which light passes, which piece of material is placed in the beam of light such that only the desired ‘shape’ of light or pattern is passed through the piece of material, while the rest of the light is blocked, thereby achieving a specific shadow/light pattern in the illuminated plane. Often in the same application, there is additionally often a need or desire to create a wash beam, i.e. a beam of light having soft edges. This is often realized by bringing the lens or optics of the hard edge spot luminary out of focus, whereby soft edge effects can be provided. However, color mixing performance often deteriorates when the lens or optics of the hard edge spot luminary is brought out of focus, which may result in undesired color fringes in the shadow/light pattern projected onto the target surface, i.e. undesired fringes of color along boundaries separating bright and darker areas in the projected pattern.
SUMMARY OF THE INVENTION
It has been noticed that lighting systems according to prior art does not provide sufficient color mixing which may result in unacceptable color fringes. It is an objective of the current invention to provide an arrangement for spot illumination that can give a good color mixing and a homogeneous spot at any focusing settings of the arrangement. Further, it may be desirable to use the same arrangement also to generate a wash beam, in other words to project an out of focus diaphragm to get a soft edge.
Generally, the above objectives are achieved by an arrangement for spot illumination according to the attached independent claim. According to a first aspect of the invention, this and other objects are achieved by an arrangement for spot illumination, comprising a tubular reflector having a reflective inner surface, the tubular reflector comprising a first section having an entrance aperture and an exit aperture being larger than the entrance aperture, and a second section having an entrance aperture and an exit aperture being substantially identical in size, the entrance aperture of the second section being positioned adjacent the exit aperture of the first section; a light source array comprising a plurality of light sources arranged to emit light into the first section of the tubular reflector at the entrance aperture of the first section; and an optical focusing element arranged proximate the second segment of the tubular reflector, wherein the first section, the second section, the light source array and the optical focusing element thereby are arranged to form a collimated beam of homogeneous color mixed light to be outputted at the exit aperture of the second section.
Advantageously such an arrangement may provide a good color mixing and a homogeneous spot at any focusing settings of the arrangement. The same arrangement may also be used to generate a wash beam.
According to a second aspect of the invention, the above object and other objects are achieved by a luminaire comprising an arrangement as disclosed above.
According to a third aspect of the invention, the above object and other objects are achieved by light system, comprising an arrangement as disclosed above.
It is noted that the invention relates to all possible combinations of features recited in the claims. Thus, all features and advantages of the first aspect likewise apply to the second and third aspects, respectively.
BRIEF DESCRIPTION OF THE DRAWINGS
The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:
FIG. 1 illustrates an LED array according to an embodiment.
FIGS. 2-5 illustrate arrangements for spot illumination according to embodiments; and
FIG. 6 illustrates an illumination pattern for an arrangement according to an embodiment.
DETAILED DESCRIPTION
The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which currently preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness, and fully convey the scope of the invention to the skilled addressee. Like reference characters refer to like elements throughout.
Multi-channel, high brightness LED light source platforms to serve the needs of various entertainment lighting applications (inter alia in the fields of theatre, touring and TV studios) are currently being developed. Such LED light source platforms may have a light output of about 10 000 lm and at least four different color channels (from a highly dense packed LED array with a diameter of less than 30 mm). Such a high brightness light source offers many advantages for spot applications. Especially it may allow to realize a hard edge spot (also referred as profile) together with on gel matching functionality. FIG. 1 illustrates a highly dense packed LED array 1 . The illustrated LED array, which is attached to a substrate 3 , has a diameter D of 29 mm and comprises six color channels and has 120 LEDs 2 .
One or more LED arrays 1 as illustrated in FIG. 1 may be used in an illumination system for spot illumination. FIG. 2 is a perspective view of a high brightness LED light source based arrangement 4 . The arrangement 4 is suitable for spot illumination. The arrangement comprises a highly dense packed LED array 1 and a mixing and/or collimating tubular reflector 5 (also known as a trumpet reflector). The tubular reflector 5 has an entrance aperture 6 a and an exit aperture 6 b . Light from the LED array 1 is received at the entrance aperture 6 a and mixed and/or collimated light is emitted at the exit aperture 6 b . According to the embodiment illustrated in FIG. 2 a first optical element 7 is attached to the entrance aperture 6 a and a second optical element 8 is attached, via a ring 9 , at the exit aperture 6 b . The second optical element 8 may for example be fixed to the ring by means of a screw arrangement 10 a - d or the like. The LED array 1 is operatively connected to a heat sink 11 . Heat generated by the LED array 1 may thereby be transmitted from the LED array 1 to the heat sink 11 . In turn the heat sink 11 is operatively connected to a fan 12 . The fan 12 may provide forced air cooling. The LED array 1 may be electrically connected to a LED driver or the like by means of one or more electrical connector 13 a - d.
FIG. 3 is an exploded view of an arrangement 14 for spot illumination according an embodiment. The arrangement 14 of FIG. 3 is similar to the arrangement 4 of FIG. 2 . The arrangement 14 comprises two sections 15 a , 15 b forming a tubular reflector (or trumpet reflector). The body of the tubular reflector may be fabricated from a polymeric material by assembly multiple pieces together or as a single piece inter alia by injection moulding or rapid prototyping. The tubular reflector has a reflective inner surface 16 so that light received by the tubular reflector is reflected at the reflective inner surface 16 and thereby results in output light emitted from the tubular reflector being mixed and/or collimated. For example, a highly reflective foil such as Miro foil may be attached (e.g. glued) onto the inner surface 16 of the tubular reflector.
In more detail the tubular reflector has two sections; a first section 15 a and a second section 15 b , each having a respective entrance aperture 17 a , 18 a and a respective exit aperture 17 b , 18 b . A light source array 1 may be arranged to emit light into the first section 15 a of the tubular reflector at the entrance aperture 17 a of the first section 15 a . An optical axis 19 may thus be formed from the light source array 1 towards the exit aperture 18 b of the second section 15 b.
The tubular reflector may have a beam shaping functionality transforming the Lambertian light distribution from the light source array 1 into the required beam shape of 10°-40° FWHM) and providing color mixing. As noted above the first section 15 a (of the tubular reflector) has an entrance aperture 17 a and an exit aperture 17 b . The first section 15 a is preferably arranged and/or orientated such that incident light is received at the entrance aperture 17 a and output light is emitted at the exit aperture 17 b . The exit aperture 17 b of the first section 15 a is larger than the entrance aperture 17 a of the first section 15 a . According to a preferred embodiment the first section 15 a has substantially a trumpet shape. More particularly, the first section 15 a may have a convex shape as seen from the optical axis 19 . The first section 15 a may further comprise multiple facets 20 a - c arranged to form a polygonal cross section along the optical axis 19 . The entrance aperture 17 a of the first reflector 15 a may thus have a polygonal cross section, such as a hexagonal, a heptagonal or an octagonal cross section. In FIG. 3 the entrance aperture 17 a of the first reflector 15 a has a heptagonal cross section.
Likewise, as also noted above the second section 15 b (of the tubular reflector) has an entrance aperture 18 a and an exit aperture 18 b . The second section 15 b is preferably arranged and/or orientated such that incident light is received at the entrance aperture 18 a and output light is emitted at the exit aperture 18 b . According to an embodiment the second section 15 b has substantially a cylindrical shape cross section as seen from the optical axis 19 . However, according to another embodiment the second reflector 15 b also has a polygonal cross section, preferably similar to the shape of the first section 15 a of the tubular reflector. More particularly the second section 15 b may have a cross section shape which corresponds to the cross section shape of the first section 15 a.
The entrance aperture 18 a of the second section 15 b and the exit aperture 18 b of the second section 15 b are substantially identical in size. The wording “substantially identical in size” should here be interpreted as being different only within a predetermined margin (such as the diameters of the apertures in question not differing more than 1-5%, or being within factory specifications). In other words, the first section 15 a may have a tubular shape whereas the second section 15 b may have a cylindrical shape. The second section 15 b and the first section 15 a are preferably arranged such that the entrance aperture 18 a of the second section 15 b is positioned adjacent the exit aperture 17 b of the first section 15 a . Preferably the entrance aperture 18 a of the second section 15 b and the exit aperture 17 b of the first section 15 a have the same diameter and/or shape.
The arrangement 14 further comprises an optical focusing element 21 . The optical focusing 21 element may be a field lens. Preferably the optical focusing element 21 is arranged proximate the second segment 15 b of the tubular reflector. For example, the optical focusing element 21 may be attached to the second segment 15 b . Alternatively the optical focusing element 21 and the second segment 15 b may be separated by a ring (not shown) or another separating element(s). According to an embodiment optical focusing element 21 is arranged in the optical path (i.e. along the optical axis 19 ) tightly between the first section 15 a (i.e. the tubular section of the reflector) and the second 15 b section (i.e. the cylindrical section of the reflector), as is disclosed in the illustrative example of FIG. 3 . More generally the optical focusing element 21 may be positioned between the entrance aperture 18 a of the second section 15 b and the exit aperture 17 b of the first section 15 a.
Other positions of the optical focusing element 21 are equally possible. The optical focusing element 21 may, for example, be positioned proximate the exit aperture 18 b of the second section 15 b of the tubular reflector. For example, the optical focusing element 21 may be positioned directly at the exit aperture 18 b . Alternatively the optical focusing element 21 and the exit aperture 18 b may be separated by a ring (not shown) or another separating element(s). Such an arrangement 22 is illustrated in FIG. 4 . The arrangement 22 of FIG. 4 is thus similar to the arrangement 14 of FIG. 3 . Hence the arrangement 22 comprises inter alia a light source array 1 , a tubular reflector having a first section 15 a and a second section 15 b , where each one of the first section 15 a and the second section 15 b has an entrance aperture 17 a , 18 a and an exit aperture 17 b , 18 b , and an optical focusing element 21 . An optical axis 19 is formed from the light source array 1 through the optical focusing element 21 towards the exit aperture 18 b of the second section 15 b.
As noted above the arrangements 14 , 22 comprises a light source array 1 which comprises a plurality of light sources 2 . The light source array 1 is arranged to emit light into the first section 15 a of the tubular reflector at the entrance aperture 17 a of the first section 15 a . The light source array 1 may therefore be positioned close to or adjacent (the entrance aperture 17 a of) the first section 15 a of the tubular reflector.
The arrangements 14 , 22 (including the first section 15 a , the second section 15 b , the light source array 1 and the optical focusing element 21 ) are thereby are arranged to form a collimated beam of homogeneous color mixed light to be outputted at the exit aperture 18 b of the second section 15 b.
FIG. 5 illustrates an arrangement 24 according to an embodiment. The arrangement 24 of FIG. 5 is similar to the arrangements 14 , 22 of FIGS. 3 and 4 . Hence the arrangement 22 comprises inter alia a light source array 1 , a tubular reflector having a first section 15 a and a second section 15 b , where each one of the first section 15 a and the second section 15 b has an entrance aperture 17 a , 18 a and an exit aperture 17 b , 18 b , and an optical focusing element 21 . An optical axis 19 is formed from the light source array 1 through the optical focusing element 21 towards the exit aperture 18 b of the second section 15 b.
The arrangement 24 further comprising a lens assembly 25 . The lens assembly 25 is arranged to controllably focus/defocus light emitted at the exit aperture 18 b of the second section 15 b . The lens assembly comprises at least two lenses 25 a , 25 b arranged in spaced relation to each other. Particularly the lens array 25 may be placed along the optical axis 19 beyond the exit aperture 18 b of the second section 15 b of the tubular reflector. At least one lens 25 a , 25 b of the lens assembly 25 is controllably moveable towards and/or away from another lens 25 a , 25 b of the lens assembly 25 and/or towards the second section 15 b of the tubular reflector. Such an arrangement may achieve a high contrast with limited blur and limited colored edges. In more detail, by such an arrangement 24 , a zoom lens can substantially be maintained in focus independently of the value of the zoom factor (i.e. the degree of zooming) or even be completely maintained in focus independently of the value of the zoom factor.
Thus, according to one aspect there may be provided a method for controlling an arrangement (or an optical system) as disclosed above, a luminaire and/or a light system comprising at least one arrangement as disclosed above. In other words, an illumination system may comprise a light source array 1 , color mixing means, such as the disclosed tubular reflector, and an adjustable optical system (e.g. zoomable and/or (de-)focusable projection system) such as the disclosed lens assembly 25 . The optical system may comprise two sections along its optical axis 19 ; a first segment, such as section 15 a and/or section 15 b , in which colors are mixed (spatial and angular) and a segment section, such as section 15 b and/or lens array 25 , in which colors are mixed at all position in the optical system of the second part. The projection system may thereby be controlled by moving the first segment and the second segment in relation to each other such that at any state the projection system projects a focal plane that is within the second segment, in which the colors are mixed, even if the projection system is defocusing to the extremes (i.e. independently of the value of the zoom factor).
According to embodiments the light source array 1 may, furthermore, comprise at least one set of light sources 2 arranged to emit light of a first color and at least one set of light sources 2 arranged to emit light of a second color different from the first color. A set of light sources 2 may be defined by a single light source. Similarly, a set of light sources 2 may comprise two or more light sources arranged together in a group. For example, a set of light sources 2 may be provided in the form of a line of light emitting diodes (LEDs). According to an embodiment the light source comprises a plurality of LEDs. Preferably the light source comprises between 5 and 250 LEDs. More preferably the light source comprises between 20 and 200 LEDs. Even more preferably the light source comprises between 70 and 150 LEDs. Increasing the number of light sources may increase the flux (in lm) of the outputted light. Increasing the number of light sources may also increase the number of different colors obtainable by the arrangement.
According to an embodiment of the invention the light source comprises LEDs of 2-8 different colors. For example, the LEDs may have white (W), red (R), green (G), blue (B), amber (A), cyan (C), deep red (dR) and/or deep blue (dB) emission spectrum. By combination thereof, any desired light spectrum is obtainable that falls within the color space made up by the color coordinates of the WRGBAdRdB starting LEDs. According to an embodiment the light source thus comprises a plurality of colors such as (RGB), (NW+WW), (RGBA), (RGBAW), (RGBW), (RGBAC), (RGBAdR), (RGBACdR), (RGBACdRW), (RGBACdRdB), or the like.
In addition, it may desirable that the light source occupies an area which is as small as possible whilst still allowing a large number of LEDs to be present. It may thus be desirable to have a high densely packed LED array. According to embodiments the plurality of light sources comprises an LED array having an EPI density between 5% and 70%. Preferably the plurality of light sources comprises an LED array having an EPI density between 15% and 50%. Under EPI density is understood the overall area of the light emissive parts of the LEDs with respect to the area of the light source.
FIG. 6 illustrates an illumination pattern 23 for an arrangement 14 , 22 as disclosed with references to FIG. 3 or 4 according to an embodiment. A gobo (or GOBO; derived from “Go Between” or GOes Before Optics originally used on film sets between a light source and the set) is a physical template slotted inside, or placed in front of, a lighting source. A gobo may thereby be used to control the shape of light emitted from a light source and/or illumination system. Such a gobo may be located at the exit of the collimation and color mixing optics of the disclosed arrangements 14 , 22 . Preferably the gobo is located close to the field or collimation lens and will be projected by an optical projection system attached to the rest of the illumination system on a scene, e.g. on a wall. Alternatively or in addition to the gobo there may be provided a photo mask, a wavelength conversion element and a beam shaping element configured to reflect, refract, absorb and/or diffract light. As a very good color mixing has been achieved at the exit aperture (i.e. close to the field or collimation lens) the illumination pattern shows a sharp pattern 23 without color fringes or collared edges.
In summary there has been disclosed an illumination system for spot illumination. The system comprises a tubular reflector with a reflective inner surface. The tubular reflector comprises two sections; a first sections (preferably with a convex shape as seen from the optical axis of the system) having an entrance aperture and an exit aperture being larger than the entrance apertures and a second sections adjacent to the first sections, the second sections having an entrance aperture and an exit aperture being substantially identical in size. The system further comprises a light source array comprising a plurality of light sources arranged to emit light (preferably of different spectral content and/or different colors) into the first sections of the tubular reflector at the entrance aperture The system further comprises an optical focusing element (such as a field lens) attached to the second sections of the tubular reflector. The light source array, the field lens, the first section and the second sections of the tubular reflector are thereby configured such that a collimated beam enabling homogeneous color mixing (special and angular) in the output light beam is formed.
The person skilled in the art realizes that the present invention by no means is limited to the preferred embodiments described above. On the contrary, many modifications and variations are possible within the scope of the appended claims. For example, the disclosed arrangement may be part of a luminaire. Thus, a luminaire may comprise one or more arrangements as disclosed above. Similarly, the disclosed arrangement may be part of a light system. As noted above, at least one of the plurality of light sources may comprise a solid-state light source such as at least one light-emitting diode (LED). Such a LED may be inorganic or organic. The plurality of light sources may alternatively or optionally comprise one or more compact fluorescence lamps (CFL), high-intensity discharge (HID) lamps and/or halogen lamps. According to the embodiment illustrated in FIG. 5 , the lens assembly 25 comprises two lenses 25 a , 25 b . Embodiments comprising any number of lenses in the lens assembly 25 a , 25 b , such as three, four, five, six lenses or more or even a single lens are equally envisaged. | There is provided an arrangement for spot illumination ( 14 ). The arrangement provides an improved collimation and color mixing unit comprising a LED array ( 1 ), a convex shaped reflector ( 15 a ), a field lens ( 21 ) and an additional cylindrical reflector ( 15 b ) at the exit aperture of the system. In combination with an optical projection system which may comprise at least two additional zoom lenses and a gate (in which several maskers, gobos or shutters could be inserted) the system allows color mixing in an extended operational range including out of focus zoom settings often used to get soft edge spots. | 5 |
FIELD OF THE INVENTION
This invention relates to distributed computing and, more particularly, to a secure data file uploading system for a distributed computer application utilizing the Internet and a Web browser as the user interface to the distributed computer application.
BACKGROUND OF THE INVENTION
Distributed computing allows members of a user community to share data. Distributed computing relies on the use of multiple computers in a distributed computer network rather than one centralized system. For example, large organizations have computers dedicated to departmental use. In a distributed computer network these computers are networked together and are not just decentralized systems without any communications between them. In addition, client/server applications tend to disburse more and more computers throughout the organization.
Some users of the community are providers of data and some users are consumers. In certain application domains, such as healthcare, providers of data require a secure user agent to upload data into the distributed computer application. If the distributed computer network relies upon the Internet for communication between users, data security becomes an important issue. With the growth of the Internet, distributed computer networks are more and more likely to use a Web browser as their user agent of choice for data file uploading from their data providers due to the user-friendly features that more and more people are accustomed to in using Web browsers and the Internet. However, it has been difficult to provide the security necessary for distributed computer applications that wish to use Web browsers and the Internet as the user interface. This is due in part to the unsecured circuitous route taken by data transmitted over the Internet and the possibility of unauthorized access of the data during transmission. In addition, in order to make such distributed computer applications affordable, there are often resource constraints that limit the use of server technology to simpler systems that are incompatible with the high security that is both desired and necessary in some cases. Finally, distributed computer networks that require a lot of effort to set up and maintain have proven to be very undesirable and not cost effective.
SUMMARY OF THE INVENTION
It is therefore desirable to securely move data files from a remote site to a distributed computer application server using a Web browser and the Internet, an intranet, or other network with standard communication protocols and to protect the distributed computer application server from any direct Internet, intranet, or other network connections. It is also desirable to use one process in a Web server that is exposed to the Internet, intranet, or other external network that will collect the data and pass the data securely through a firewall and a router to a second process in the distributed computer application server that processes the data and is protected from the Internet, intranet, or other external network.
The present invention is a distributed computer application that utilizes the Internet and Web browsers as the interface to the distributed computer application. Users who are providers of data utilize Secure Sockets Layer (SSL) enabled HyperText Transport Protocol (HTTP), referred to as HTTPS (HTTP with SSL), to encrypt communications between their Web browser and the distributed computer application server. SSL is a leading security protocol on the Internet and provides server authentication and optionally user authentication. HTTP is a communications protocol used to connect servers on the World Wide Web. Its primary function is to establish a connection with the Web server and transmit HTML pages to the client Web browser.
The HTTPS capability is used to upload data files and handle the data file transfer from the Web browser to the external HTTP distributed computer application Web server. A collection Java servlet on the external HTTP distributed computer application Web server handles the data file upload from the Web browser, checks for required form elements, adds, the Internet Protocol (IP) address of the computer running the Web browser software to the form elements, re-POSTs the data to a processing Java servlet on an internal HTTP distributed computer application WEB server, records the response of the processing Java servlet on the internal HTTP distributed computer application WEB server, and returns the response to the initiating Web browser.
The processing Java servlet on the internal HTTP distributed computer application WEB server is used to handle the data file upload from the processing Java servlet on the external HTTP distributed computer application Web server, checks for required form elements, checks that the identity for the POST is valid, saves the data file locally on the internal HTTP distributed computer application WEB server, and returns a response to the collection Java servlet.
When an HTTPS session is started, the Web browser sends its public key to the Web server so that the Web server can securely send a secret key to the Web browser. The Web browser and Web server exchange data via secret key encryption during that session. Using HTTPS in the Uniform Resource Locator (URL) instead of HTTP directs the message to a secure port number rather than the default Web port number of 80. The session is then managed by a security protocol. The security protocol is a communications protocol that encrypts and decrypts the message for on-line transmission. The security protocol can also provide user authentication.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an embodiment of the present invention where files are uploaded from a Web browser over the Internet to an application server.
FIG. 2 shows an HTML page that is displayed on a Web browser for uploading data files to a distributed computer application in an embodiment of the present invention.
FIGS. 3A and 3B show a block diagram of the overall process of uploading a data file from a Web browser over the Internet to an application server in an embodiment of the present invention.
DETAILED DESCRIPTION
FIG. 1 shows an embodiment of the present invention where files are uploaded from a Web browser over the Internet 114 to an application server. Referring now to FIG. 1, Web browser 102 and Web browser 108 are connected to the Internet 114 through Internet connection 106 and Internet connection 112 respectively. Internet 114 may also be an intranet or some other type of computer network.
Web browser 102 has access to storage device 104 which contains one or more files to be uploaded. Web browser 108 has access to storage device 110 which also contains one or more files to be uploaded. One skilled in the art will recognize that many Web browsers could be connected to the Internet 114 , but only Web browser 102 and Web browser 108 are shown for simplicity.
Distributed computer application 140 is also connected to the Internet 114 through Internet connection 116 . Distributed computer application 140 has a firewall 118 and router 118 that handles all traffic transmitted over Internet connection 116 from Internet 114 . Web server 122 and application server 130 are connected to firewall 118 and router 118 through connection 120 and connection 128 respectively. Distributed computer application 140 could be directed to one of many different kinds of business, educational, charitable, or scientific endeavors. In one embodiment of the invention, distributed computer application 140 is directed to the healthcare industry where a secure framework for uploading patient/referral/member data into the application is needed. Users gather the patient/referral/member data and upload it to distributed computer application 140 using Web browser 102 or 108 where it is then added to the application database. Users may also access the data contained in the database from their Web browsers.
Web server 122 has HTTP server 124 and collection Java servlet 126 . Application server 130 has HTTP server 132 and processing Java servlet 134 .
Web browser 102 is loaded on a computer workstation, such as a personal computer, or made available to a user from a terminal (not shown in FIG. 1 ). One skilled in the art will recognize that other user agents besides Web browser 102 could be used. The user at the computer workstation or terminal is a provider of data for distributed computer application 140 . Using Web browser 102 , the user makes a request from Web browser 102 to distributed computer application 140 to load the HTML page 200 for the purpose of uploading one or more data files to distributed computer application 140 . HTTP server 124 within Web server 122 receives the request and returns the HTML page 200 to Web browser 102 which is then displayed within Web browser 102 . Distributed computer application 140 may require a login procedure which is well known in the art. From Web browser 102 , the user selects an option to upload a data file to distributed computer application 140 . The user may upload a data file from within an HTML page as shown in FIG. 2 .
After the user selects the command to upload the data file, the request to upload the data file is sent from Web browser 102 to distributed computer application 140 . This request is received in HTTP server 124 which invokes collection Java servlet 126 . If collection Java servlet 126 has not already been loaded, it will be loaded at this time. Normally, collection Java servlet 126 is loaded only once. Thereafter, multiple threads of collection Java servlet 126 will handle multiple client requests.
Collection Java servlet 126 handles the data file upload from Web browser 102 . The data file is transmitted in a secure fashion by utilizing SSL. SSL sits on top of all socket communications. SSL encrypts all the data before the data are transmitted from Web browser 102 over the Internet 114 , and decrypts the data once the data reach Web server 122 . Web server 122 is configured to enable the use of SSL and is equipped with a digital certificate. Optionally, Web browser 102 may also be equipped with a digital certificate to allow for user authentication. Collection Java servlet 126 also checks for required form elements and adds the IP address of the computer running Web browser 102 to the form elements. The data file is then re-POST-ed by collection Java servlet 126 to processing Java servlet 134 . If processing Java servlet 134 is not yet loaded, it will be loaded at this time as described above in the discussion of collection Java servlet 126 .
Processing Java servlet 134 handles the data file upload from collection Java servlet 126 . Processing Java servlet 134 checks for the required form elements, and checks if the identity for the POST is valid. If valid, processing Java servlet 134 then saves the data file on storage device 136 connected to application server 130 . All the uploaded files are then made available to other users who have access to distributed computer application 140 .
FIG. 2 shows an HTML page that is displayed on a Web browser for uploading data files to a distributed computer application in an embodiment of the present invention. Referring now to FIG. 2, HTML page 200 is displayed on Web browser 102 or Web browser 108 after a user has requested distributed computer application 140 and the upload option. Only authorized users may upload data. Users are authorized by making an entry in a configuration file within HTTP server 124 . Various form elements are presented in HTML page 200 to be entered by the user.
The user enters the user's login name in user name field 202 . The user enters their PIN number in PIN number field 204 . The user may select a drop-down menu in document type field 206 to choose the type of document to be uploaded, such as a referral response data file, a patient data file, or a member data file. The user may enter the data file name to be uploaded in file name field 208 or click on a browse button (not shown in FIG. 2) and select the data file to be uploaded, which will then appear in file name field 208 . The user then clicks on upload content button 210 , which sends input initiating the data file upload process more fully described below in the discussion of FIGS. 3A and 3B.
FIGS. 3A and 3B show a block diagram of the overall process of uploading a data file from a Web browser over the Internet 114 to an application server ( 130 in an embodiment of the present invention. Referring now to FIG. 3A, in step 302 Web browser 102 or Web browser 108 (FIG. 1) is loaded on a computer workstation, such as a personal computer, or made available to a user from a terminal. For the purposes of discussion in this FIG. 3, it is assumed that Web browser 102 is loaded. In step 304 input is received in Web browser 102 requesting distributed computer application 140 (FIG. 1 ). In step 306 HTTP server 124 in Web server 122 (FIG. 1) receives the request, and returns HTML page 200 (FIG. 2) to Web browser 102 , which is then displayed within Web browser 102 .
In step 308 input is received in the form elements in HTML page 200 and input is received from selecting upload content button 210 (FIG. 2) for the upload command. HTTP server 124 receives the upload request in step 310 . HTTP server 124 invokes the collection Java servlet 126 (FIG. 1) in step 312 if it has not already been loaded.
In step 314 collection Java servlet 126 handles the HTTPS enabled data file upload from Web browser 102 . In step 316 collection Java servlet 126 checks for errors in the data received. Examples of errors include no data in the data file uploaded, or no data in a form element. Referring now to FIG. 3B, step 318 determines if any errors were found in step 316 . If errors were found, then in step 320 collection Java servlet 126 returns an HTML page to Web browser 102 identifying the errors found. Back button input from Web browser 102 is received in step 322 . Control then returns to step 306 of FIG. 3A where HTTP server 124 receives the back button request and returns HTML page 200 for redisplay on Web browser 102 , allowing the user to correct the incorrect entries.
If step 318 determines that no errors were found in step 316 , then in step 324 collection Java servlet 126 adds the EP address of the computer running Web browser 102 to the form elements and re-POSTs the data file to processing Java servlet 134 (FIG. 1 ). If processing Java servlet 134 has not yet been invoked, it is loaded at this time.
In step 326 , processing Java servlet 134 handles the data file upload from Web server 122 to application server 130 (FIG. 1 ). Processing Java servlet 134 checks for errors in the data received in step 328 and verifies that the identity for the POST is valid. Examples of errors include an invalid user login name or invalid PIN number.
Step 330 determines if any errors were found in step 328 . If errors were found, then in step 332 processing Java servlet 126 returns an HTML page 200 to Web browser 102 identifying the errors found. Back button input from Web browser 102 is received in step 334 . Control then returns to step 306 of FIG. 3A where HTTP server 124 receives the back button request and returns HTML page 200 for redisplay on Web browser 102 , allowing the user to correct the incorrect entries.
If step 330 determines that no errors were found in step 328 , then in step 336 processing Java servlet 134 stores the uploaded data file in the application database in storage device 136 (FIG. 1) connected to application server 130 . Processing Java servlet 134 in step 338 returns an HTML page 200 to Web browser 102 verifying that the data file was successfully uploaded.
In step 340 , if there are more data files to upload, control returns to step 306 of FIG. 3 A. If there are no more data files to upload in step 340 , then the data file uploading process ends.
Having described a presently preferred embodiment of the present invention, it will be understood by those skilled in the art that many changes in construction and circuitry and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the present invention, as defined in the claims. The disclosures and the description herein are intended to be illustrative and are not in any sense limiting of the invention, defined in scope by the following claims. | Disclosed is a distributed computer application that utilizes the Internet and Web browsers as the interface to the distributed computer application server. Users who are providers of data utilize Secure Sockets Layer (SSL) enabled HyperText Transport Protocol (HTTP) to encrypt communications between their Web browser and the distributed computer application Web server (HTTPS). A Java servlet on the external HTTPS distributed computer application Web server handles the file upload from the Web browser and re-POSTs the data to a processing Java servlet on an internal HTTPS distributed computer application application server. The processing Java servlet on the internal HTTPS distributed computer application server is used to handle the file upload from the collection Java servlet on the external HTTPS distributed computer application Web server and saves the file locally in a database on the internal HTTPS distributed computer application application server. | 7 |
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to the field of use of register files. More particularly, the present invention relates to using additional bits in the register file to handle write-after-write hazards and eliminate bypass comparators.
[0003] 2. Description of Related Art
[0004] Register files are arrays in processors that store one or more registers. In processors capable of processing more than one instruction at a time, it is common to associate with each of these registers a bit which indicates whether the data inside each respective register is either: (1) updated and ready to be used; or, (2) being modified or produced and therefore not available. This bit is termed a “scoreboard” bit.
[0005] For example, if a scoreboard bit for a particular register is set, then the next instruction which needs to access this register cannot execute until the scoreboard bit for this register has been cleared. To clear this register bit, a preceding operation (i.e., the operation that is generating/modifying the data to be placed/returned to this register) needs to complete execution. Thus, if a program were to (1) execute a LOAD of a first value and place it into a register R4; and (2) execute an ADD of the first value with a second value contained in a register R5; then there is clearly a dependency on the LOAD operation. The use of the scoreboard bit by a circuit to “lock-out” access to a register that is being used is referred to as a “hardware interlock.” The hardware interlock is used instead of placing the extra burden in software.
[0006] Thus, in a processor where there exists multiple execution units, and where one of the execution units has an operation that is waiting to be executed that depends on a result from a previous operation, the register that is waiting to receive the result is “locked-out” from being accessed until the register's scoreboard bit is cleared. After the result has been placed into the register and the scoreboard bit has been cleared, the execution unit containing the waiting operation can access the data in the register.
[0007] In cases where an operation is waiting for a result to return from an execution unit, time can be saved by not having to wait for the result to be first placed into the register and then read out again by the waiting execution unit. Instead, bypassing is used to send the result to the waiting execution unit at the same time the result is sent to the register—significantly speeding-up operations.
[0008] Bypassing is used where a processor contains some collection of data in a register file and also contains a set of execution units, each of which may take a varying amount of time to complete an operation. An execution unit can take a varying amount of time to complete an operation because, for example, the execution unit is a multicycle execution unit or because the processor has a pipelined implementation where no operation finishes immediately.
[0009] Without bypassing, an execution unit that is waiting for another operation to finish must wait until that operation is finished and the result sent back to the register file before reading the result out again. The execution unit must also wait until the scoreboard bit for the result is cleared and the result is read out before the instruction is issued. Thus, the time that elapses during the writing of the result into the register file and the reading out of the result again before the execution of the instruction that depends on the result adds additional delay.
[0010] [0010]FIG. 1 shows a prior art bypass circuit where a set of multiplexors (MUX) 12 , 8 , 14 , 22 , and 24 is placed into a set of result return data paths 16 and 26 . Set of result return data paths 16 and 26 returns results from execution units 10 and 20 , respectively, to a register file 30 (no control circuit is shown in FIG. 1 for simplicity).
[0011] [0011]FIG. 1 contains a set of register file scoreboard bits 28 along with register file 30 . The output of register file 30 is fed to MUX 12 , MUX 14 , MUX 22 , and MUX 24 . The output of MUX 12 is used as one input to execution unit 10 , while the output of MUX 14 is used as the other input to execution unit 10 . The output of MUX 22 is used as one input to execution unit 20 , while the output of MUX 24 is used as the other input for execution unit 20 .
[0012] The output of execution unit 10 is returned on a result return data path 16 to register file 30 . Similarly, the output of execution unit 20 is returned to register file 30 on a result return data path 26 . Note that result return data path 16 and result return data path 26 might also be used by other execution units not shown in the figure. In addition, MUX 12 , MUX 14 , MUX 22 , and MUX 24 receive both the output from execution 10 and the output from execution 20 through the use of result return data path 16 and result return data path 26 , respectively.
[0013] Thus, in FIG. 1, every input of every execution unit has one three (3) input multiplexor that provides, as input, either the output of the register file or the result that is returning on one of the two result return data paths. As described below, every execution unit may also be able to latch the values that appear on its inputs, to handle situations where all the inputs are not available simultaneously.
[0014] For example, if execution unit 10 is an adder which executes in one cycle and the next instruction, which is also an ADD instruction, needs the result, both operations can issue sequentially because the result from the first ADD instruction is written into the register file at the same time that result is bypassed into the adder again so that the subsequent ADD can use it immediately.
[0015] The output of each MUX selects the data from one of three inputs depending on which control line is active. The control lines come from the system described in FIG. 2, below.
[0016] [0016]FIG. 2 shows a bypass circuit 40 having a select register file control line (SR F ) 66 , a select B1 control line (S B1 ) 68 , and a select B2 control line (S B2 ) 70 for determining from where an execution unit receives an operand. S RF 66 , S B1 68 , and S B2 70 are sent to one of the MUX's of FIG. 1. Thus, each of the MUX's in FIG. 1, specifically, MUX 12 , MUX 14 , MUX 22 and MUX 24 , receive control signals S RF 66 , S B1 68 , and S B2 70 from a bypass control circuit similar to bypass control circuit 40 . A scoreboard bit line, coming out of register file 30 , in FIG. 2 provides the value of the scoreboard bit for the particular register being accessed for determining whether to use the value from the register file or a value from one of the result return data paths.
[0017] Bypass circuit 40 also contains a first comparator 50 and a second comparator 60 . One of the inputs for both first comparator 50 and second comparator 60 indicates the operand register address of the operand for which the current operation is waiting. For first comparator 50 , the other input is the result return data path 16 register address, which indicates the register file address into which the result contained on result return data path 16 is returned after first execution unit 10 has completed the previous operation. For second comparator 60 , the other input is the result return data path 26 register address, which indicates the register file address into which the result contained on result return data path 26 is returned after second execution unit 20 has completed the other previous operation.
[0018] First comparator 50 and second comparator 60 both operate in the same manner, which is to output a logical one if both inputs are equal. For example, if the operand register address is equal to the result return data path 16 register address, then first comparator 50 outputs a logical one.
[0019] The output of first comparator 50 is received by a first AND gate 52 . First AND gate 52 also receives the output of a NOT gate 64 . Similarly, the output of second comparator 60 is received by a second AND gate 62 . Second AND gate 62 also receives the output of NOT gate 64 .
[0020] The input to NOT gate 64 is the scoreboard bit line, which, as indicated above, provides the value which comes from one of the scoreboard bits from register file scoreboard bits 28 . Specifically, the scoreboard bit used is the one associated with the register data being requested by the execution unit.
[0021] During operation of the circuit of FIG. 2, if the scoreboard bit coming out of register file scoreboard bits 28 indicates the operand is to be retrieved from register file scoreboard bits 28 , then the value coming out of the scoreboard is used, as S RF has a value of a logical one. If the scoreboard bit coming from register file scoreboard bits 28 is a logical one, representing that the data in register file 30 is not valid, then the MUX uses the result coming from one of the result return data paths, depending on the output of bypass control circuit 40 . Effectively, these three control lines (S RF 66 , S B1 68 , and S B2 70 ) together determine whether a valid result is available for the operation and thus allows the processor to issue the instruction and let the instruction execute.
[0022] The operand address comes from the instruction word and is the register address where the desired operand for the operation is located. For example, if an instruction is to add the value in register file 30 at location 4 to the value in register file 30 at location 5 and there is no valid data in register file 30 at location 4 , then the execution unit executing the instruction waits until it detects a value destined for register file 30 at location 4 being returned on a result return data path before beginning to execute.
[0023] A comparator is needed for each possible destination bus to execution unit input combination as any execution unit can be waiting for any result return data path for a result. Therefore, in FIG. 1, where there are two result buses and four total operand inputs, eight comparators are needed because the bypass logic, consisting of two comparators per execution unit input, one for each bus, has to be duplicated for each of these locations.
[0024] Generally, the number of comparators increases as the product of the number of execution units and the number of result return data paths. The number of return paths may increase with the number of execution units, to allow all or most of the execution units to be producing results simultaneously. This would lead to the number of comparators increasing as a square factor of the number of execution units. For example, if the number of execution units is doubled, the number of comparators might increase by a factor of 4.
SUMMARY OF THE INVENTION
[0025] An apparatus including a set of data storage units having a set of scoreboard bits associated with the set of data storage units. The apparatus also includes a first execution unit having an output coupled to the data storage unit and a first input; a first switching unit having an output coupled to the first input of the first execution unit and a first input coupled to the output of the first execution unit; and, a first bypass control unit coupled to the first switching unit. The first bypass control unit is configured to cause the first switching unit to couple the output of the first switching unit to the first input of the first switching unit based upon the set of scoreboard bits. The system also provides a method including the steps of receiving a first instruction; and, storing a first address location and a first access path specifier for a first operand associated with the first instruction; wherein the first access path specifier indicates a source of the first operand.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] [0026]FIG. 1 is a block diagram of a prior art system for bypassing data having a multiplexor for selecting bypass data.
[0027] [0027]FIG. 2 is a block diagram of a prior art control system for controlling the multiplexor of the prior art system for bypassing data.
[0028] [0028]FIG. 3 is a system for bypassing data configured in accordance with one embodiment of the present invention.
[0029] [0029]FIG. 4 is a system for bypassing data configured in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0030] The present invention provides a method and apparatus for multi-bit scoreboarding. The invention may be used to handle write-after-write hazards, or to reduce or eliminate bypass comparators, or both. For purposes of explanation, specific embodiments are set forth to provide a thorough understanding of the present invention. However, it will be understood by one of ordinary skill in the art, from reading this disclosure, that the invention may be practiced without these details. Further, although the present invention is described through the use of register file scoreboard indicators, most, if not all, aspects of the invention apply to register files in general. Moreover, well-known elements, devices, process steps and the like are not set forth in detail in order to avoid obscuring the present invention.
[0031] To eliminate much of the bypass circuitry, additional scoreboard bits in the register file are used to indicate the result bus from which the result is returning in addition to indicating that a result needs to be written back to the register file.
[0032] In one embodiment, multiple bits are used, with one of the configurations of the bits being all zeros indicating the result in the register file being valid. In an alternate embodiment, a separate scoreboard bit is used to indicate whether the operand in the register file is valid and an additional set of “return path” bits can be used to indicate the return path for result.
[0033] [0033]FIG. 3 illustrates a bypass control circuit 80 that is configured in accordance with one embodiment of the present invention. Bypass control circuit 80 provides more efficient bypassing, as explained below, and is coupled to a register file 104 having a scoreboard/result path indicator 100 that stores additional information about the status of each register in register file 104 .
[0034] Bypass control circuit 80 is also coupled to MUX 12 to control the selection of data that is fed into one of the inputs of execution unit 10 from either register file 104 , result return data path 16 , or result return path 26 . In one embodiment, there is also another bypass control circuit (not shown), coupled to control the selection of the data to pass to the other input of execution unit 10 . In another embodiment, each MUX of each execution unit has a bypass control circuit similar to bypass control circuit 80 . In yet another embodiment, every execution unit may have latches on its inputs, to handle the case where all of its inputs would not otherwise be available at the same time. These latches are controlled using the “operand ready” indicators that are produced by the bypass control circuit associated with each input.
[0035] In bypass control circuit 80 , an AND gate 82 with logically inverted inputs is used to determine whether or not to use the data contained in register file 30 , as explained below. The inputs of AND gate 82 come from scoreboard/result path indicator 100 . The output of AND gate 82 is a select register file control line (S RF ) 84 .
[0036] If scoreboard/return path indicator 100 show sthat the data in register file 30 is not valid (i.e., the data has been scoreboarded), then MUX 86 is used to select and pass through the result return data path register address for the result return data path that is indicated by scoreboard/return path indicator 100 . The output of MUX 86 is fed to a comparator 88 that also receives the register address of the operand for which the execution unit is waiting. The output of comparator 88 is provided to a second AND gate 90 and a third AND gate 92 , which are used to select between result return data path 16 and result return data path 26 , respectively.
[0037] If a register has been scoreboarded, address decoder 94 determines which one, if any, of the result return data paths from which a result is to be returned by decoding the bits in scoreboard/return path indicator 100 associated with that register. If address decoder 94 detects that the data that is to be returned into the register is to come from result data path 16 , then address decoder 94 asserts a logical one on the output that is coupled to second AND gate 90 . Similarly, if address decoder 94 detects that the data that is to return into the register is to come from result data path 26 , then address decoder 94 asserts a logical one on the output that is coupled to third AND gate 92 .
[0038] Bypass control circuit 80 also contains an OR gate 102 which receives the outputs of AND gate 82 , second AND gate 90 , and third AND gate 92 , to indicate an “operand ready” signal. An OR gate is used because when any of the AND gates (i.e., AND gate 82 , second AND gate 90 , and third AND gate 92 ), are asserted, there is an operand that is ready to be used.
[0039] Continuing to refer to FIG. 3, an example of the functioning of the system is when an instruction is issued to return a result to register 0 [R0]. Thus, R0 has its scoreboard bit set. At the same time the scoreboard bit is set, result return data path indicator information is also encoded into the return path/scoreboard bits to indicate the result return data path from which the result for R0 returns. The information specifying the result return data path on which the result returns may be determined directly from the instruction in some cases, or may need to be obtained from the hardware that decides which execution unit will perform the operation. Then, when a subsequent instruction is issued that needs to use the value in R0 before the first instruction has returned a result in R0, the instruction would “scoreboard” (i.e., the instruction has to wait for the first instruction to return a result to R0 before it can proceed to execute).
[0040] In the prior art, bypassing could be implemented constantly only by examining all result return data paths for the result that is to be returned to R0. In contrast, the present system can effect bypassing by only examining the encoding of the return path/scoreboard bits for R0. The encodings and their meanings are as follows:
TABLE 1 Return Path/Scoreboard Bit Encoding RP/SCBD BITS Location From Which to Obtain Result 00 Register File 10 Result Return Data Path 16 11 Result Return Data Path 26
[0041] In one embodiment, two bits for each register are used to represent the total possible number of locations for result sources, and the logical inverse value of both are provided as inputs into AND gate 82 . If both bits are 0, then the result is to come from register file 104 , so the value in register file 104 is selected and passed through to the execution unit. If the first bit is not a zero, then the second bit is also examined to see from which result return data path the result is coming. The result return data path indicates the register address at which the data is placed.
[0042] Comparator 88 indicates when the pertinent result appears on the result return data path because it could be any number of cycles before the pertinent result appears. In the meantime, several other results can travel over that bus so the bypass control circuit ensures that not only is the system notified of the result return data path of the pertinent result, the system receives the pertinent result off of the right result return data path.
[0043] Rather than comparing against all the possible result return data paths that might return the result and selecting among those, a result return data path can be identified so that only results returning to register file 104 on that result return data path are examined for their destination address. For example, in a system with five result return data paths returning results, instead of requiring five comparators in the bypass control circuit, bypass control circuit 80 is modified to only uses a single comparator with the only changes being a five input MUX instead of a two input MUX and an increase in the number of bits stored in scoreboard/result return data path indicator 100 to indicate five possible result return data paths.
[0044] An OR gate 102 receives the signals from S RF 84 , S RP16 96 , and S RP26 98 and logically OR's them together so that if any one of them are true, a valid result is available (i.e., the operand is “ready”) and can be sent (i.e., bypassed or read directly from the register file) to execution unit 10 , possibly at the same time the result is being sent to register file 104 .
[0045] After the valid result is returned to register file 104 , the two bits associated with indicating the status of the result in register file 104 in scoreboard/result return data path indicator 100 is cleared (i.e., set to logical zeros), to indicate that the result in register file 104 is now valid.
[0046] The system shown in FIG. 3 and described above works well in systems that do not allow multiple instructions that all return a result to the same register address to be executing simultaneously. This is the case in many processors. However, increased performance can often be obtained by loosening this restriction, and allowing multiple instructions that all return their result to the same register to be executing simultaneously, even if other instructions are issued between them that use those results. Increased performance can also be gained in this situation if the instructions can return their results in an order different from the order in which they were issued. This is called out-of-order execution. In this case, additional efforts must be made to ensure that instructions are executed using the right input values.
[0047] [0047]FIG. 4 is a block diagram of bypass control circuit 80 which is modified to prevent a write-after-write (WAW) hazard. A WAW occurs in a processor when different instructions return results to the same register location in an order different than the order in which those instructions were issued.
[0048] For example, Table 2a contains an example of a WAW hazard situation where four instructions are issued:
TABLE 2a WAW Hazard INSTRUCTION Execution Unit RETURN PATH LOAD(4, R1) Execution Unit 10 Result Return Data Path 16 ADD(R1, R2, R3) doesn't matter doesn't matter MOV(8, R1) Execution Unit 20 Result Return Data Path 26 ST(R1, 12) doesn't matter doesn't matter
[0049] where LOAD(X,Y) is an instruction that loads a value X into register Y; ADD(X,Y,Z) adds a value X and a value Y and place the result in a location Z; MOV(X,Y) is an instruction that moves the data at a memory location X into a register Y; and ST(X,Y) is an instruction that stores the value in a register X into a memory location Y. The Execution Unit column indicates which execution unit to which the instruction issues, and the Return Path column indicates on which return path the result of the instruction returns.
[0050] A WAW can occur when the LOAD and MOV instructions return their results either in an out-of-order or parallel fashion. Without WAW protection, the MOV instruction can execute and finish before the LOAD instruction. When the LOAD instruction finishes execution after the MOV instruction, R1 is loaded with the value of 4, which overwrites the value of 8 returned by the MOV instruction. Thus, the ST instruction, instead of correctly storing a value of 4 into memory location 12 , incorrectly stores the value of 8 into memory location 12 .
[0051] To prevent WAW errors, scoreboard/result return data path indicator 100 , which indicates the pertinent return path on which a result is to return, can be used to allow a subsequent instruction which is to use that result to monitor for the data to return on the pertinent return path. In one embodiment, subsequent instructions that also use that same return path to return a value to the same register are not allowed to issue. Subsequent instructions that return a result either to a different register or using a different path are allowed to issue. The combination of the register the result is intended for and the return path it is returning are combined to uniquely identify the result. The execution unit assigned to process a subsequent instruction that is waiting for a result is given this unique register/return path pair (instead of just the register as would be done in the prior art) when that subsequent instruction is issued, and stores/uses this unique identification to ensure that the subsequent instruction only uses the appropriate result.
[0052] Using the example given in Table 2a to illustrate this process, first the load instruction issues. Assume that the load takes an arbitrarily long time to complete. When the next instruction that uses the result of the load issues (the ADD instruction) the execution unit that the instruction is assigned to is given both the register address (R1) and the result return data path ( 16 ), and begins to wait for the result (“R1 on result return data path 16 ”) to appear. Then the MOV instruction issues. Assume that the MOV instruction does not return its result immediately. Then the ST instruction issues, and the execution unit it is assigned to is given “R1 on result return data path 26 ” to look for.
[0053] In one scenario, the LOAD instruction may return its result first. In this case, the unit executing the ADD instruction sees the result being returned on result return data path 16 and bypasses the result into itself. The unit executing the ST instruction is not monitoring result return data path 16 and therefor does not see a result being returned to R1. Later, when the MOV instruction returns its result on result return data path 26 , the unit executing the ST instruction sees that result and bypasses it into itself.
[0054] In another possible scenario, the MOV instruction may return its result before the LOAD instruction. In this case, the unit executing the ST instruction sees the result, since it is being returned on result return data path 26 , and the unit executing the ADD instruction does not see the result, since it is not on result return data path 16 . Therefore, the unit executing the ST bypass the result into itself, and the unit executing the ADD does not. Later, when the LOAD instruction returns its (out-of-order) result via result return data path 16 , the unit executing the ADD instruction sees the result and bypasses it into itself.
[0055] In both scenarios, through the use of the result return data path information in combination with the register address, each operation was furnished with the correct input values. This would also have been true in the third possible scenario, where both results are returned simultaneously.
[0056] Out-of-order result returns to the register file itself (as opposed to returns to the bypass mechanisms) can be handled by a number of mechanisms, depending on the requirements of the instruction set architecture. Reorder buffers are one possible solution, which hold out-of-order results until all the instructions issued before the one that generated the result have returned their results. This mechanism reorders the out-of-order results so that they are written to the register file in the original program order. Some architectures, however, may be able to exploit this invention to simplify the process that writes results to the register file.
[0057] If a processor can guarantee that all instructions, once issued, will return a result, then a result that returns to the register file may be discarded (instead of being written to the intended register) if there is another instruction, issued after the one that generated this result, that will or has already returned a result to the same register. This is because all already-issued instructions that required this particular result will have obtained it through the bypass mechanisms, and all instructions that have not yet issued will not require this result, but will instead require the result generated by the subsequent instruction that has already issued. If this is the case, then the information in the scoreboard bits can be used to control writes to the register file. For each register, the scoreboard bits either contain the result return data path that the most recently issued instruction that returns a result to this register will use, or it indicates that the most recently issued instruction that returns a result to this register has completed execution and has returned its result. In either case, if a result is returned that does not match the expectations of the scoreboard bits, it could only have come from an instruction that was issued before the most recent one that returns or returned a value to this register, and the returned result can therefor be safely ignored.
[0058] If this mechanism for controlling the writing of results to the register file is employed, then in the example give in table 2a, assuming that the MOV instruction issues before the LOAD instruction returns its result, then regardless of whether the LOAD operation returns its result before or after the MOV operation returns its result, the LOAD operation's result will not be written into R1. This is because the scoreboard bits are indicating that the most current result for R1 will arrive on result return data path 26 , not on result return data path 16 , which is what the LOAD uses to return its result. The ADD operation, however, will still receive the correct value, via the bypass mechanisms previously discussed.
[0059] [0059]FIG. 4 is a block diagram of the circuit of FIG. 3 modified to handle write-after-write (WAW) hazards, including an Sb latch 122 and a regadr latch 120 that hold the required information on the source of the inputs. The figure shows only the bypass control logic for MUX 12 . An identical circuit is used to control MUX 14 . Execution unit 10 has the ability to latch the input it receives from MUX 12 and MUX 14 , when the “Operand Ready” indicator associated with each is true. It also must to latch the operation to be performed when that operation is issued to it. When execution unit 10 has received and latched all of the inputs needed for the operation it has been issued, execution unit 10 then performs the stored operation and returns the result via result return data path 16 .
[0060] When an instruction to be executed is issued to execution unit 10 , the following operations occur:
[0061] 1. Execution unit 10 latches the instruction to be executed.
[0062] 2. Bypass control circuit 80 latches the register address and access path specifier for the operand that will be delivers through MUX 12 . The access path specifier is derived from the information in scoreboard/return path indicator 100 and indicates that the operand will be obtained from either register file 104 , result return data path 16 , or result return data path 26 .
[0063] 3. Bypass control circuit for MUX 14 (not shown), which in one embodiment of the invention is identical to bypass control circuit 80 that controls MUX 12 , latches the register address and access path specifier for the operand that will be delivered through MUX 14
[0064] Bypass control circuit 80 then functions in one of the three following mutually-exclusive manners:
[0065] 1. If the access path specifier latched in Sb latch 122 indicates that the result is to be obtained from register file 104 , then MUX 12 is controlled so that the value on the input connected to register file 104 is presented on the output of MUX 12 . After this has been accomplished, the assertion of the “Operand Ready” indicator causes execution unit 10 to latch the value of the input that is connected to the output of MUX 12 .
[0066] 2. If the access path specifier latched into Sb Latch 122 indicates that the operand will be obtained from result return data path 16 , then MUX 86 is controlled so that result return data path 16 register address is presented on its output, and therefor to one of the inputs of comparator 88 . Address decoder 94 produces a true value on the output connected to AND gate 90 , and a false value on the output connected to AND gate 92 . When result return data path 16 contains the value to be written to a register, the address of that register appears on result return data path 16 register address. When this is equal to the register address stored in regadr latch 120 , the output of comparator 88 becomes true. This causes the output of AND gate 90 to become true, since both of its inputs are true. The output of AND gate 90 being true causes MUX 12 to be controlled so that the value on result return data path 16 is routed to the output of MUX 12 . The output of AND gate 90 being true also causes the “Operand Ready” indicator to become true. This causes the execution unit 10 to latch the value being output by MUX 12 .
[0067] 3. If the access path specifier latched into Sb Latch 122 indicates that the operand will be obtained from result return data path 26 , then MUX 86 is controlled so that the result return data path 26 register address is presented on its output, and therefor to one of the inputs of comparator 88 . Address decoder 94 produces a true value on the output connected to AND gate 92 , and a false value on the output connected to AND gate 90 . When result return data path 26 contains the value to be written to a register, the address of that register appears on result return data path 26 register address. When this is equal to the register address stored in regadr latch 120 , the output of comparator 88 becomes true. This causes the output of AND gate 92 to become true, since both of its inputs are true. The output of AND gate 92 being true causes MUX 12 to be controlled so that the value on result return data path 26 is routed to the output of MUX 12 . The output of AND gate 92 being true also causes the “Operand Ready” indicator to become true. This causes the execution unit 10 to latch the value being output by MUX 12 .
[0068] After one of these three actions has occurred, execution unit 10 will have latched the correct value for the operand that is to be obtained through MUX 12 . In one embodiment of the invention, an identical process occurs with respect to the operand that is to be obtained through MUX 14 . When both of these processes have completed, execution unit 10 can proceed with the execution of the instruction it was issued.
[0069] It is to be noted that in describing the workings of the system, only a limited number of execution units and other components is used. However, the system can be scaled to handle unlimited numbers of execution units, return paths, and components. It is also to be noted that in describing the workings of the system, only a single execution unit was associated with each data return path. However, the system allows any number of execution units to return data on the same return path, and also allows one execution unit to return results on multiple return paths.
[0070] While the present invention has been particularly described with reference to the various figures, it should be understood that the figures are for illustration only and should not be taken as limiting the scope of the invention. Many changes and modifications may be made to the invention, by one having ordinary skill in the art, without departing from the spirit and scope of the invention. It should also be understood that many of the details of the timing and control circuitry needed to create a complete processing system form the invention are not described in detail, but that these may be readily constructed by one having ordinary skill in the art, without departing from the spirit and scope of the invention. | What is disclosed is an apparatus including a set of data storage units having a set of scoreboard bits associated with the set of data storage units; a first execution unit having an output coupled to the data storage unit and a first input; a first switching unit having an output coupled to the first input of the first execution unit and a first input coupled to the output of the first execution unit; and, a first bypass control unit coupled to the first switching unit; wherein the first bypass control unit is configured to cause the first switching unit to couple the output of the first switching unit to the first input of the first switching unit based upon the set of scoreboard bits. What is also disclosed is a method including the steps of receiving a first instruction; and, storing a first address location and a first access path specifier for a first operand associated with the first instruction; wherein the first access path specifier indicates a source of the first operand. The method and apparatus allows the elimination of bypass comparators and also handles write-after-write hazards. | 6 |
BACKGROUND OF THE INVENTION
[0001] This invention relates generally to magnetic disk data storage systems, and more particularly to the use of a ramp to facilitate the loading and unloading of sliders.
[0002] Magnetic disk drives are used to store and retrieve data for digital electronic apparatuses such as computers. In FIGS. 1A and 1B, a magnetic disk data storage system 10 of the prior art includes a sealed enclosure or housing 12 , a spindle motor 14 , a magnetic medium or disk 16 , supported for rotation by a drive spindle S 1 of the spindle motor 14 , a voice-coil actuator 18 and a load beam 20 attached to an actuator spindle S 2 of voice-coil actuator 18 . A slider support system consists of a flexure 22 coupled at one end to the load beam 20 , and at its other end to a slider 24 . The slider 24 , also commonly referred to as a head or a read/write head, typically includes an inductive write element with a sensor read element.
[0003] As the motor 14 rotates the magnetic disk 16 , as indicated by the arrow R, an air bearing is formed under the slider 24 allowing it to “fly” above the magnetic disk 16 . Discrete units of magnetic data, known as “bits,” are typically arranged sequentially in multiple concentric rings, or “tracks,” on the surface of the magnetic disk 16 . Data can be written to and/or read from essentially any portion of the magnetic disk 16 as the voice-coil actuator 18 causes the slider 24 to pivot in a short arc, as indicated by the arrows P, over the surface of the spinning magnetic disk 16 . The design and manufacture of magnetic disk data storage systems is well known to those skilled in the art.
[0004] Reducing the distance between the slider 24 and the spinning disk 16 , commonly known as the “fly height,” is desirable in magnetic disk drive systems 10 as bringing the magnetic medium closer to the inductive write element and sensor read element improves signal strength and allows for increased areal densities. However, as the fly height is pushed to lower values, the effects of contamination at the head-disk interface become more pronounced. Specifically, debris may be collected over time on the air bearing surface of the slider 24 and which may ultimately cause the slider 24 to crash into the magnetic disk 16 causing the disk drive system 10 to fail. Consequently, reducing contamination within the sealed enclosure 12 is a continuing priority within the disk drive industry.
[0005] One strategy that has been used to reduce the debris that collects on slider 24 is to focus on the tribology at the head-disk interface to reduce the amount of contact between the slider 24 and the disk 16 when the system 10 is started and stopped. Traditionally, when a system 10 was shut down the slider 24 was parked on a track at the inner diameter (ID) of the disk 16 commonly known as a landing zone. There the slider 24 would rest in contact with the surface of the disk 16 until the disk was spun again, at which point the air bearing would form and the slider 24 would lift back off of the surface. Unfortunately, the friction and wear that occurred in these systems at the head-disk interface, even with improved lubricants, created unacceptable amounts of debris on the slider 24 to allow for still lower fly heights. In order to reduce friction and wear at the head-disk interface so as to reduce debris accumulation, the landing zone was improved by making it textured, often with a pattern of bumps, in order to reduce the contact area between the slider 24 and the disk 16 , among other reasons.
[0006] Textured landing zones proved effective to a point, however the need to fly the slider 24 still lower, with the inevitable need to reduce contamination further, lead to the development of techniques whereby the slider 24 is held off of the surface of the disk 16 when not in use. Such techniques seek to avoid any contact between the slider 24 and disk 16 at all. However, simply lifting the slider 24 higher off of the surface of the disk 16 is not sufficient because a system 10 in a portable computer system is subject to shock that can cause the slider 24 to slap into the disk 16 . Therefore, a technique used in the prior art to securely park the slider 24 away from the surface of the disk 16 , as shown in FIG. 2, is to employ a small ramp 30 placed proximate to the outer diameter (OD) of the disk 16 and a tab 32 attached to the slider 24 . As the voice-coil actuator 18 causes the slider 24 to move toward the extreme OD the tab 32 rides up on the ramp 30 and lifts the slider 24 away from the surface. The slider 24 is pushed still further along the ramp 30 past the OD of the disk 16 to be parked on a flat or slightly indented portion on the ramp 30 .
[0007] [0007]FIGS. 3 and 4 serve to better illustrate the relationships between the components of ramp systems of the prior art. FIG. 3 shows an elevational view, taken along the line 3 - 3 in FIG. 2, of a slider 24 of the prior art suspended beneath a load beam 20 by a flexure 22 . Attached to the end of the load beam 20 is a tab 32 intended to move in sliding contact with a ramp 30 for loading and unloading the slider 24 . Although shown as attached to the end of the load beam 20 , it should be noted that the tab 32 is typically formed as an integral part of the load beam 20 .
[0008] [0008]FIG. 4 shows an elevational view, taken along the line 4 - 4 of FIG. 2, of the ramp 30 relative to the tab 32 , read slider 24 , and the disk 16 , when the slider 24 is flying and the tab 32 is disengaged from the ramp 30 . For clarity, the load beam 20 and the flexure 22 are not shown. The tab 32 has a rounded bottom surface to reduce the contact area with the ramp 30 when the two are in sliding contact. Arrows in FIG. 4 indicate the directions of motion of the load beam 20 for both loading and unloading.
[0009] One problem with a ramp 30 of this design is that the tab 32 is in sliding contact with the ramp 30 each time the system 10 is started or stopped. The sliding contact produces wear contamination that can be transferred to the disk 16 to be picked up by the air bearing surface of the slider 24 . The wear may be reduced by shaping the tab 32 so that the surface that contacts the ramp 30 is convex and by employing a lubricant. Although the amount of wear debris formed in this way is less significant compared to that which is generated with textured landing zones, nevertheless it may interfere with the aerodynamics of the slider 24 at very low fly heights and lead to crashes.
[0010] Another problem encountered with ramps 30 is that the slider 24 is not entirely parallel to the surface of the disk 16 . Rather, the leading edge of the slider 24 , the one facing into the direction of the rotation of the disk 16 , is higher than the trailing edge of the slider 24 to provide lift. Viewed another way, the pitch on the slider 24 causes the trailing edge to be closer to the surface. Similarly, since the air flow under the side of the slider 24 nearest the OD is always greater than under the side nearest the ID, the slider 24 may have some roll such that the ID edge of the slider is lower than the OD edge. Consequently, the corner of the slider 24 on the ID side of the trailing edge is commonly closest to the surface. As a slider 24 is loaded over a disk 16 the tab 32 slides down the ramp 30 until the lift experienced by the slider 24 is sufficient to cause the slider to fly.
[0011] What is desired, therefore, is a way to park the slider 24 on a ramp 30 while minimizing as much as possible the wear between the tab 32 and the ramp 30 . It is further desired to provide a smoother transition during loading and unloading.
SUMMARY OF THE INVENTION
[0012] The present invention provides for a ramp to assist the loading and unloading of a slider in a magnetic disk drive. The ramp comprises a body having a first surface and a second surface and a plurality of apertures extending between them, where each aperture has a first opening at the first surface and a second opening at the second surface. The first surface of the ramp further comprises a sloped segment and a straight segment, with the sloped segment being acutely angled with respect to the second surface. The ramp of the present invention directs a portion of a flow of air proximate to a spinning disk through the apertures in order to lift and cushion a tab attached to a load beam from which a slider is also suspended.
[0013] In a preferred embodiment of the present invention the air flow emerging through the first openings is sufficient to suspend the tab above the surface of the ramp. By maintaining an air bearing between the tab and the ramp while the slider is loaded and unloaded, wear and contamination from sliding contact can be greatly reduced. Another advantage realized by the present invention is that an air bearing can smooth the transition both as the tab leaves the ramp during loading of the slider, and as the tab re-engages the ramp during unloading.
[0014] In other embodiments the air flow emerging through the first openings is not sufficient to hold the tab completely off of the surface of the ramp. In still other embodiments the air flow emerging through the first openings is sufficient to hold the tab completely off of the surface of the ramp only over some length of the ramp such as the sloped segment. These embodiments still provide an advantage over the prior art in that any lift at all that is provided to the tab will tend to reduce the contact force between the ramp and the tab. Any reduction in the contact force will further tend to reduce wear and contamination from sliding contact. The lift provided to the tab in these embodiments, although not enough to suspend it completely off of the surface of the ramp, nevertheless can also smooth the transitions as the tab engages and disengages from the ramp.
[0015] Further embodiments of the ramp are directed at variations of the second surface. The second surface may be flat, but in some embodiments the second surface is non-planar and shaped to better urge a flow of air proximate to the surface of the disk into the plurality of apertures. For example, the second surface may be concave or may be provided with an aerodynamic shape. Shaping the second surface is advantageous to the present invention in that it provides a greater air flow into the plurality of apertures thus providing a greater lifting force against a tab situated above the first surface.
[0016] Still other embodiments are directed towards the apertures themselves. Each aperture has a first and second opening and in some embodiments their cross-sectional areas are substantially equal. In other embodiments the cross-sectional area of the first opening is less than the cross-sectional area of the second opening. In further embodiments the apertures are substantially straight, while in others they take complex paths through the body of the ramp. For example, an aperture may have an S-shape. Yet other embodiments are directed towards apertures that intersect the second surface at an angle to a tangent of the second surface at the location of the aperture's second opening. Still more embodiments are directed to apertures that branch within the body of the ramp such that a second opening may connect to more than one first opening. Yet other embodiments are directed to apertures having nozzles formed at their first openings. Finally, some embodiments are directed to the cross-sectional shapes of the first and second openings and to the arrangements of the openings on the first and second surfaces.
[0017] The embodiments directed at different aperture configurations are advantageous in that they allow an air flow to be collected in a first location, say over the OD of the disk, to be redirected to a second location that is not directly over the first location, such as the straight segment of the ramp. These embodiments also allow the air flow out of the apertures to be shaped and otherwise manipulated, for example by providing nozzles to increase the speed of the air flow. Such variations provide greater lift to a tab over some regions of the ramp than over other regions. A properly shaped aperture can reduce turbulence and thus reduce resistance to the flow of air.
[0018] More embodiments are directed at ramp systems for loading and unloading at least two sliders. Such an embodiment comprises a body having a first portion and a second portion where each portion is a ramp as described above, and the first portion is proximate to a first surface of a disk and the second portion is proximate to a second surface of the disk. The two portions, taken together, provide the body of the ramp system. The ramp system can be positioned around the OD of the disk. This design is desirable as disk drives typically are configured to be able to utilize both surfaces of a magnetic disk by employing a separate slider for each.
[0019] Further embodiments are directed to disk drives for storing and retrieving magnetic data comprising a housing containing a rotatable magnetic disk, an actuator configured to pivot a load beam proximate to a surface of the disk, a slider and a tab each attached to the load beam, the tab extending the load beam in a first direction, and a ramp as described above. The ramp is situated such that the tab engages a sloped segment of the ramp as the load beam is pivoted to an outside diameter of the surface of the disk. Additional embodiments of the disk drive are directed to variations of the tab, and specifically to the surface of the tab that faces the ramp. This surface may have a non-planar component, for example, it can be concave or have an aerodynamic shape to help it glide on the air bearing. Shaping the surface of the tab can be an advantage in that it allows the tab to experience a greater lifting force from the air flow provided by the apertures beneath it.
[0020] Lastly, embodiments are directed to methods for loading and unloading a slider. Both methods include providing a rotatable magnetic disk disposed within a housing, providing an actuator disposed within the housing and configured to pivot a load beam proximate to a surface of the disk, providing a slider and a tab attached to the load beam wherein the tab extends the load beam in a first direction, and providing a ramp as described above. The method of loading the slider further includes rotating the magnetic disk to provide an air flow through the plurality of apertures, pivoting the load beam while the air flow through the apertures provides a lifting force to the tab as it moves with respect to the ramp from a straight segment to a sloped segment, and finally flying the slider such that the tab disengages from the ramp.
[0021] The method of unloading the slider further includes flying the slider over the disk, pivoting the load beam such that the tab engages a sloped segment of the ramp as the load beam is pivoted to an outside diameter of the disk, moving the tab over the sloped segment and onto the straight segment of the ramp, and reducing the rotation of the disk to reduce the flow of air through the apertures to allow the tab to be supported on the straight segment of the ramp. Further embodiments of both methods include supporting the tab on an air bearing while it is moving relative to the ramp. Other embodiments of both methods are directed to providing an amount of lift to the tab that is not sufficient to raise the tab off of the ramp, but is sufficient to lower the contact force between the tab and the ramp.
[0022] These and other advantages of the present invention will become apparent to those skilled in the art upon a reading of the following descriptions of the invention and a study of the several figures of the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, with like reference numerals designating like elements.
[0024] [0024]FIG. 1A is a partial cross-sectional elevation view of a magnetic data storage system of the prior art;
[0025] [0025]FIG. 1B is a top plan view of the magnetic data storage system taken along line 1 B- 1 B of FIG. 1A;
[0026] [0026]FIG. 2 is a top plan view of a magnetic data storage system equipped with a ramp and a tab of the prior art;
[0027] [0027]FIG. 3 is an elevational view taken along the line 3 - 3 of FIG. 2
[0028] [0028]FIG. 4 is an elevational view taken along the line 4 - 4 of FIG. 2;
[0029] [0029]FIG. 5 is a perspective view of a ramp of the present invention;
[0030] [0030]FIG. 6A is a partially broken view of the ramp of FIG. 5;
[0031] [0031]FIG. 6B is an elevational view of a cross-section of a portion of a ramp provided with an aperture;
[0032] [0032]FIG. 7 is a cross-section of an alternative embodiment of a ramp showing a branching of apertures;
[0033] [0033]FIG. 8A is a cross-section of a ramp system of the present invention for one disk;
[0034] [0034]FIG. 8B is a cross-section of a ramp system of the present invention for a disk stack;
[0035] [0035]FIG. 9 is a plan view of the ramp showing various first opening shapes and arrangements;
[0036] [0036]FIG. 10A is a cross-section of an alternative embodiment of the ramp of the present invention;
[0037] [0037]FIGS. 10B and 10C are side elevational views of alternative embodiments of the ramp of the present invention;
[0038] [0038]FIG. 10D shows an elevational view of the ramp situated above the disk to show how the second surface may be shaped along the minor axis of the ramp;
[0039] [0039]FIG. 11 shows a cross-section of the tab of the present invention disposed over the ramp;
[0040] [0040]FIG. 12 shows a flow diagram for the method of loading the slider; and
[0041] [0041]FIG. 13 shows a flow diagram of for the method of unloading the slider.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] [0042]FIGS. 1A, 1B, and 2 - 4 were discussed above with reference to the prior art.
[0043] [0043]FIG. 5 shows a perspective view of the ramp 40 of the present invention. The ramp 40 comprises a body 42 having a first surface 44 and a second surface 46 and a plurality of apertures 48 extending between the two. The body 42 is preferably formed of a plastic, such as Teflon, or plastic-like material selected for having very low levels of outgassing of volatile organic compounds and very low levels of particle shedding. The body 42 should also be formed of a material that is resistant to wear and that can be readily machined or otherwise formed. In some embodiments ceramic materials or metallic materials can be used to form the body 42 . Further embodiments include surface treatments, lubricants, and specially formed solid surface layers to provide additional wear resistance to first surface 44 .
[0044] The first surface 44 is further divided into two sections, a straight segment 50 and a sloped segment 52 , the sloped segment 52 being acutely angled with respect to the second surface 46 . The straight segment 50 is a location where a tab 32 rests when a slider 24 is parked. Although shown as flat in FIG. 5, the straight segment 50 in other embodiments can be provided with a notch, a step, or a depression, for example, to more securely hold the tab 32 when the slider 24 is at rest. Such designs are well known in the art. The sloped segment 52 provides a transition region to guide the slider 24 towards the surface of the disk 16 during loading, and to gently bring the slider 24 away from the surface of the disk 16 when unloading. While the sloped segment 52 is shown in FIG. 5 as being a flat section acutely angled with respect to the second surface 46 , the sloped segment 52 take more complex forms in other embodiments. For example, the sloped segment 52 can be contoured so that towards one end it smoothly transitions into the straight segment 50 and on the other end it is flared to be more nearly parallel to the plane defined by the surface of the disk 16 .
[0045] The ramp 40 is situated such that it partially overhangs the OD of the disk 16 . As the disk 16 rotates, a layer of air proximate to the surface of the disk 16 is swept along with it. This flow of air is commonly known as windage. The air flow near the OD of the disk 16 is complex and will be affected in the vicinity of the ramp 40 both by the ramp 40 itself and by the presence of the nearby slider 24 and load beam 20 . In general, however, the air flow near the OD has both radial and circumferential components, moving both towards the OD of the disk 16 and in the direction of the rotation of the disk 16 . The second surface 46 can be shaped in order to better capture some of the air flow underneath the ramp 40 . An advantageous shape of the second surface 46 can direct a greater portion of the air flow near the OD of the disk 16 into the plurality of apertures 48 so that more air will emerge through the first surface 44 as shown by the arrows in FIG. 5.
[0046] [0046]FIG. 6A shows a partially broken view of the ramp 40 taken along the line 6 - 6 of FIG. 5 to illustrate various embodiments of apertures 48 . In one embodiment, an aperture 48 ′ has a first opening 54 ′ at the first surface 44 and a second opening 56 ′ at the second surface 46 . For this aperture 48 ′ the cross-sectional areas of the first opening 54 ′ and the second opening 56 ′ are substantially equal and the aperture 48 ′ between them is substantially straight and perpendicular to the second surface 46 . Aperture 48 ′ represents the simplest type of aperture 48 and should be the easiest to manufacture, for example, by laser drilling.
[0047] Aperture 48 ″ shows a more complex aperture 48 . Aperture 48 ″ differs from aperture 48 ′ in four ways: the cross-sectional area of the first opening 54 ″ is less than the cross-sectional area of the second opening 56 ″, the aperture 48 ″ is neither straight nor perpendicular to the second surface 46 , and the first opening 54 ″ includes a nozzle region 55 . Of course, other embodiments may be more complex than aperture 48 ′ while less complex than aperture 48 ″. For example, one embodiment of aperture 48 might be straight with a cross-sectional area of the first opening 54 less than the cross-sectional area of the second opening 56 and not include a nozzle 55 .
[0048] Non-linear apertures 48 can be used to bring an air flow from a second opening 56 situated over the surface of the disk 16 to a first opening 54 on the first surface 44 that is substantially distant from the OD of the disk 16 . In order to provide a flow of air to the straight segment 50 , for example, it may be necessary to direct the flow of air from second openings 56 , located proximate to the OD of the disk 16 , through a plurality of apertures 48 and to first openings 54 located on the straight segment 50 . Aperture 48 ″ in FIG. 6A illustrates this configuration. Aperture 48 ″ also illustrates a nozzle region 55 that is shaped to increase the speed of the air as it exits through the first opening 54 ″.
[0049] [0049]FIG. 6B is an elevational view of a cross-section of a portion of a ramp provided with an aperture 48 that intersects the second surface 46 at an angle α to a tangent T of the second surface 46 at the location of the second opening 56 . In some embodiments it is desirable to angle the apertures 48 at the second surface 46 to take advantage of an air flow that impinges on the second surface 46 at or near the angle α to the tangent T of the second surface 46 .
[0050] Other embodiments of apertures 48 involve branching. For example, the second opening 56 can connect to a plurality of first openings 54 . FIG. 7 illustrates two of many possible ways in which such branching can occur. In one embodiment, several apertures 48 lead away from one second opening 56 . In another embodiment, a single aperture 48 splits into two apertures 48 , one of which splits again into two more apertures 48 . In both illustrated embodiments three first openings 54 connect to one second opening 56 , however in other embodiments two first openings 54 connect to one second opening 56 and in still other embodiments more than three first openings 54 connect to one second opening 56 . Yet other embodiments are directed to a ramp 40 where the plurality of apertures 48 includes a selection from amongst the various types of apertures 48 described above. Computer modeling, such as by computational fluid mechanics and computational structural mechanics, can be employed to determine optimal numbers, arrangements, shapings and sizes of the apertures 48 , as will be appreciated by those skilled in the art.
[0051] [0051]FIG. 8A shows a cross-section of a ramp system 70 of the present invention that allows for the simultaneous loading and unloading of two sliders 24 on one disk 16 . The ramp system 70 includes a body having a first portion 72 and a second portion 74 , each portion 72 and 74 including a first surface 44 , a second surface 46 , and a plurality of apertures 48 extending between them. The first portion 72 is proximate to a first surface 73 of the disk 16 and the second portion 74 is proximate to a second surface 75 of the disk 16 . Each portion 72 and 74 is essentially an independent ramp 40 . Since most disk drive systems 10 employ disks 16 having magnetic layers on both surfaces 73 and 75 they also include two sliders 24 attached to independent load beams 20 operated by a single actuator 18 . A ramp system 70 allows the sliders 24 on both sides of the disk 16 to be loaded and unloaded with all of the advantages of the present invention. In disk drive systems 10 having more than one disk 16 , frequently referred to as a disk stack, the ramp system 70 can be built to provide a ramp 40 for each surface 73 and 75 of each disk 16 as shown in FIG. 8B.
[0052] A further benefit of a ramp system 70 is that second surface 46 can be contiguous with the two portions 72 and 74 . Since much of the windage moves in a radial direction as shown in FIG. 8A, the U-shaped portion of the second surface 46 will tend to block the flow of air and direct it instead into the plurality of apertures 48 in the first and second portions 72 and 74 . It should be noted that although shown as U-shaped, this portion can take other forms as well such as a squared-off shape or a V-shape.
[0053] [0053]FIG. 9 shows a plan view of a ramp 40 to illustrate that first openings 54 may have various shapes. These shapes may reflect the cross-sectional shapes of the apertures 48 extending into the ramp 40 , or they may be formed only at the first surface 44 . Such shapes include, but are not limited to, circles, squares and diamonds, ovals or ellipses having different ratios of major to minor axes, commas, and hexagons. Hexagons, for example, are preferably arranged to form a honeycomb structure. The apertures 48 can be arranged in a lattice, such as illustrated by the hexagonal arrangement of the hexagons in FIG. 9, or they can be arranged in concentric circles as shown on the sloped segment 52 , or arranged such that the density of first openings 54 is greatest along the center line of the first surface 44 . Many other arrangements are also possible. Similarly, second openings 56 on the second surface 46 can also take any of these shapes or arrangements.
[0054] FIGS. 10 A- 10 C show ramp embodiments 40 having second surfaces 46 that are specially shaped to direct air into second openings 56 . In FIGS. 10A and 10B the second surface 46 is essentially concave. In FIG. 10A the second surface is further made wavy, grooved, or corrugated so that second openings 56 can be angled to face into the air flow as shown. FIG. 10B shows a second surface 46 that curves below the level of the edge of the disk 16 to better collect the air flow coming off of the disk 16 and urge it into second openings 56 . FIG. 10C shows a more aerodynamically shaped second surface 46 that extends downward over the disk 16 to narrow the gap between the ramp 40 and the disk 16 to increase the speed of the air flow through this gap.
[0055] [0055]FIG. 10D shows an elevational view of a ramp embodiment 40 as seen from a point located over the center of the disk 16 . This perspective shows that the second surface 46 can be shaped along a minor axis of the ramp 40 as well as along a major axis of the ramp 40 as shown in FIGS. 10 A- 10 C. In FIG. 10D the shaping of the second surface 46 along the minor axis of the ramp 40 is concave. However, in other embodiments the second surface 46 can be flat or convex along the minor axis. In still other embodiments the second surface has grooves or channels set along the minor axis, with such grooves or channels extending substantially in the direction of the major axis of the ramp 40 . Computer modeling, such as by computational fluid mechanics and computational structural mechanics, can be employed to design the shape of the second surface 46 for a given air flow around the disk 16 , as will be appreciated by those skilled in the art. Also shown in FIG. 10D is that the straight segment 50 and the sloped segment 52 can be made convex rather than flat to further reduce the contact area between the tab 32 and the ramp 40 if ever they should touch.
[0056] [0056]FIG. 11 shows a cross-section of a tab 80 positioned over the straight segment 50 of a ramp 40 . Tab 80 varies from tab 32 of the prior art shown in FIG. 4 in that tab 80 has a shape designed to take advantage of the flow of air out of first openings 54 to generate lift. The shape of tab 80 in FIG. 11 is essentially concave on the surface 82 that faces the ramp 40 . Just as with the second surface 46 of the ramp 40 , the surface 82 of the tab 80 can be shaped along one or two axes. Hence, the concavity shown in FIG. 11 may represent either a section through a cylinder, a section through a hemispherical cap, or a section through a surface that is partially cylindrical and partially hemispherical. A cylindrical shape to the surface 82 would produce two lines of contact with the first surface 44 when the tab 80 is touching the ramp 40 . A hemispherical shape to the surface 82 would produce a circular line of contact with the first surface 44 when the tab 80 is touching the ramp 40 . Where the first surface 44 is convex, such as shown in FIG. 10D, either a cylindrical shape or a hemispherical shape to surface 82 would produce simply two points of contact with the first surface 44 when the tab 80 is touching the ramp 40 .
[0057] Tab 80 is preferably formed of a plastic, such as Teflon, selected for having very low levels of outgassing of volatile organic compounds and very low levels of particle shedding. The tab 80 should also be formed of a material that is resistant to wear and that can be readily machined or otherwise formed. In some embodiments ceramic materials or metallic materials can be used to form the tab 80 . Further embodiments include surface treatments or specially formed solid surface layers to provide additional wear resistance to the surface 82 . Tab 80 can be made thin to minimize mass, as the air flow coming out of first openings 54 is intended to lift the tab 80 off of the first surface 44 of the ramp 40 . Minimizing mass to make lifting the tab 80 easier also suggests forming the tab 80 from a low-density material. Additionally, the tab 80 can be made wider in a direction parallel to the long axis of the ramp 40 , compared with tabs 32 of the prior art, in order to be situated over a greater number of first openings 54 at any given moment.
[0058] [0058]FIG. 12 shows a flow chart illustrating the process 100 for loading a slider 24 according to the present invention. The process 100 includes the act or operation 102 of providing a magnetic disk 16 within a housing 12 , the act or operation 104 of providing an actuator 18 and a load beam 20 , where the actuator 18 is configured to pivot the load beam 20 proximate to the surface of the disk 16 , the act or operation 106 of providing a slider 24 attached to the load beam 20 , the act or operation 108 of providing a tab 80 attached to the load beam that extends the load beam in a first direction, and the act or operation 110 of providing a ramp of the present invention. The process 100 further includes the act or operation 112 of rotating the disk 16 , the act or operation 114 of pivoting the load beam 20 , and the act or operation 116 of flying the slider 24 .
[0059] Acts or operations 102 , 104 , and 106 are all well known in the prior art. Act or operation 108 involves providing a tab 80 attached to the load beam 20 . While a tab 80 of the present invention is preferable, it should be noted that a tab 32 of the prior art can also be used. It should also be pointed out that in preferred embodiments the tab 80 or 32 will be integral to the load beam 20 rather than a separate piece that has been joined to the load beam 20 . The tab 80 is intended to extend the load beam 20 in a first direction, where the first direction is defined as the long axis of the load beam 20 . Extending the load beam 20 in a first direction with a tab 32 that is integral to the load beam 20 is also well known in the prior art and is shown in FIGS. 2 and 3. It should also be noted that although the tab 32 in FIG. 3 is shown as projecting out from the top surface of the load beam 20 , the tab 32 or a tab 80 can also be extended from the end of the load beam 20 , or extended from the flexure 22 . The tab 80 needs to extend sufficiently beyond the end of the load beam 20 so that when the tab 80 engages the ramp 40 neither the flexure 22 nor the slider 24 contacts the ramp 40 .
[0060] In act or operation 110 a ramp 40 of the present invention is provided. The ramp 40 should be positioned such that as the actuator 18 pivots the load beam 20 towards the OD of the disk 16 the tab 80 engages the ramp 40 . The ramp 40 should be rigidly attached to the housing 12 , or to another component within the system 10 that itself is rigidly attached to the housing 12 , so that the ramp 40 can be securely positioned proximate to a surface of the disk 16 at the OD. The ramp 40 should be proximate to the surface of the disk 16 , but not so close that a sudden jolt or shock could cause the ramp 40 to contact the disk 16 . In act or operation 110 the ramp should be further positioned so that the tab 80 is in contact with the straight segment 50 of the first surface 44 .
[0061] Act or operation 112 involves rotating the disk 16 in order to provide a flow of air through the plurality of apertures 48 . Since the amount of air flowing through the plurality of apertures 48 is proportional to the speed of the disk 16 , and the lifting force felt by the tab 80 is proportional to the amount of air flowing through the apertures 48 , it is therefore desirable to spin the disk 16 to its operating rotational rate, or nearly so, in act or operation 112 . At a minimum, however, the disk 16 should be spinning at least as fast as is required to fly the slider 24 . Preferably, the air flow through the plurality of apertures 48 in act or operation 112 is sufficient to lift the tab 80 completely off of the straight segment 50 of the ramp 40 . However, even if the air flow is not sufficient to lift the tab 80 completely off of the straight segment 50 , any air flow at all will provide some benefit by reducing the contact force between the tab 80 and the ramp 40 , thus reducing the rate with which contamination is generated through wear.
[0062] Act or operation 114 involves pivoting the load beam 20 , including the tab 80 and the slider 24 attached thereto, so that the tab 80 moves from a straight segment 50 of the ramp 40 to a sloped segment 52 of the ramp 40 . Ideally, the tab 80 should be supported on an air bearing provided by the air flow through the plurality of apertures 48 as the load beam 20 is pivoted by the actuator 18 . In some embodiments, however, the air flow is only sufficient to lift the tab 80 off of the ramp 40 over a limited portion of the range of motion in act or operation 114 , and in still other embodiments the tab remains in sliding contact through the entire act or operation.
[0063] Act or operation 116 involves flying the slider 24 over the surface of the disk 16 so that the tab 80 disengages from the ramp 40 . More specifically, as actuator 18 pivots the load beam 20 in the direction of the ID of the disk 16 , the tab 80 follows the contour of the ramp 40 as it moves along the sloped segment 52 . As the tab 80 nears the end of the sloped segment 52 the slider 24 comes ever closer to the surface of the disk 16 and encounters an ever increasing flow of air proximate to the surface of the disk 16 . This flow of air provides lift to the slider 24 . The lift felt by the slider 24 is transferred to the flexure 22 , the load beam 20 , and ultimately to the tab 80 .
[0064] In the prior art, the lift transferred to the tab 32 had to be sufficient to overcome attractive forces tending to hold the tab 32 against the surface of the ramp 30 before the tab 32 would disengage from the ramp 30 . However, in act or operation 116 of the present invention the tab 80 is supported off of the first surface 44 by a cushion of air so that the attractive forces between the ramp 40 and the tab 80 are minimized or eliminated. Consequently, unlike the prior art, in a preferred embodiment of process 100 there is not a sharp transition at the moment when the tab 80 separates from the ramp 40 . Instead, in act or operation 116 the transition as the tab 80 disengages the ramp 40 is smooth and gradual as the slider 24 gains the necessary lift to fly over the surface of the disk 16 . In embodiments of act or operation 114 in which the tab 80 is in sliding contact with the ramp 40 at the time act or operation 116 begins, the transition in act or operation 116 may be abrupt as in the prior art. However, the lift provided to the tab 80 , even if insufficient to raise the tab 80 off of the ramp 40 prior to the end of act or operation 114 , can still reduce the magnitude of the jolt experienced by the slider 24 as the tab 80 disengages in act or operation 116 .
[0065] [0065]FIG. 13 shows a flow chart illustrating the process 120 for unloading a slider 24 according to the present invention. The process 120 includes the act or operation 122 of providing a spinning magnetic disk 16 within a housing 12 , the act or operation 124 of providing an actuator 18 and a load beam 20 , where the actuator 18 is configured to pivot the load beam 20 proximate to the surface of the disk 16 , the act or operation 126 of providing a slider 24 attached to the load beam 20 that is flying over the surface of the disk 16 , the act or operation 128 of providing a tab 80 attached to the load beam that extends the load beam in a first direction, and the act or operation 130 of providing a ramp of the present invention such that the rotating disk 16 provides a flow of air through the plurality of apertures 48 . The process 100 further includes the act or operation 132 of pivoting the load beam 20 to engage tab 80 with ramp 40 , the act or operation 134 of moving the tab 80 along the ramp 40 , and the act or operation 136 of reducing the rotation rate of the disk 16 .
[0066] Acts or operations 122 , 124 , and 126 are all well known in the prior art. Act or operation 128 involves providing a tab 80 attached to the load beam 20 and is essentially the same as act or operation 108 described above. In act or operation 130 a ramp 40 of the present invention is provided, where the rotating disk 16 provides a flow of air through the plurality of apertures. The ramp 40 should be positioned as described in act or operation 110 except that the tab 80 will not be engaged with it.
[0067] Act or operation 132 involves pivoting the load beam 20 , including the tab 80 and the slider 24 attached thereto, such that the tab 80 engages a sloped segment 52 of the ramp 40 as the load beam 20 is brought to the OD of the disk 16 . The flow of air through the apertures 48 can serve to cushion the engagement, gently guiding the tab 80 onto the sloped segment 52 , in contrast to the prior art in which the tab 32 simply collided with the ramp 30 . It will be appreciated by one skilled in the art that gently guiding the tab 80 onto the sloped segment 52 will tend to preserve the surface of the ramp 40 and reduce the amount of wear and contamination generated by engaging the tab 80 with the ramp 40 .
[0068] Act or operation 134 is directed to moving the tab 80 over the sloped segment 52 and then onto the straight segment 50 of the ramp 40 . Ideally, the flow of air through the plurality of apertures 48 provides a lifting force to the tab 80 that is sufficient to keep the tab 80 separated from the ramp 40 by an air bearing as the tab 80 moves across sloped segment 52 and onto straight segment 50 . However, even if the lift provided to the tab 80 is insufficient to maintain a separation between the tab 80 and the ramp 40 during act or operation 134 , it can still reduce the magnitude of the contact force between them and thereby reduce wear and contamination.
[0069] Act or operation 136 involves reducing the rotation rate of the disk 16 , thereby reducing the flow of air through the plurality of apertures 48 so that the lifting force experienced by the tab 80 is reduced. As the lifting force diminishes the tab 80 gently sets down on the straight segment 50 of the ramp 40 . Once the disk 16 slows sufficiently and the air flow through the plurality of apertures 48 has stopped the slider 24 is said to be parked.
[0070] Although the foregoing invention has been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims. | Windage proximate to a spinning disk within a disk drive is directed through a plurality of apertures in a ramp situated near the outside diameter of the disk. A tab extending from a load beam that supports a slider rests on the ramp when the drive is not in use. When the drive is started the disk begins to spin and an actuator moves the load beam to bring the slider over the surface of the disk. As the load beam moves, the tab is guided along the ramp and cushioned by the air flow emerging from apertures in the ramp beneath it. When the drive is stopped the actuator brings the load beam back so that the tab engages the ramp. A cushion of air is again provided as the tab is moved along the ramp as the tab is returned to a parked position. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to an improved transmission mechanism used to control the movement of a presser in sewing machines.
There are a variety of sewing machines on the market, which can be divided into two categories-hand-activated and electro-activated. The former is generally used in ordinary households while the latter is widely used in factories.
The need exists for a durable, inexpensive and easily constructed or repaired transmission mechanism in an electro-activated sewing machine. In the past, sewing machines have been constructed with the transmission mechanism positioned horizontally under the carriage of the sewing machine.
The traditional transmission mechanism for a sewing machine is very complicated, containing a large number of parts that are exposed to the environment and are thereby easily contaminated by dust, etc., which causes malfunctions to occur. Another disadvantage of the traditional transmission mechanism is that the presser moves vertically while the plunger of the transmission means moves horizontally. Therefore, extra parts are required by the transmission means to transform the horizontal movement of the plunger of the transmission means into the vertical movement of the presser. Consequently, the exposure of these members outside the transmission means makes the total length thereof relatively large, which in turn requires the horizontal orientation of the transmission mechanism resulting in an increase in the cost and the difficulty of repair.
The art has long sought a transmission mechanism which is durable, inexpensive and easily constructed or repaired. As shown below the transmission mechanism of the present invention meets this need.
SUMMARY OF THE INVENTION
The present invention, which includes the transmission means to be interconnected to the presser, overcomes the foregoing disadvantages to achieve the required functions. The present invention comprises a transmission means attached to a specially designed base plate, which may be readily and easily constructed, assembled underneath the carriage of the sewing machine.
This invention permits the transmission means to encompass all necessary parts inside its own casing. Furthermore, the transmission means is so constructed as to be placed vertically. Therefore, the plunger of the transmission means moves vertically and cooperates directly with a presser, known per se, disposed in the sewing machine.
It is an objective of the invention therefore to provide an improved transmission mechanism enclosing most of the parts inside the transmission means for protection against an environment full of dust and cloth fibers.
Another objective of the invention is to provide a vertically placed transmission mechanism, thereby reducing the number of connecting parts between the transmission mechanism and presser.
Further objectives and advantages of the present invention will become apparent as the following description proceeds, and the features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a transmission mechanism for a sewing machine in accordance with the present invention;
FIG. 2 is a partially exploded view of the transmission mechanism of FIG. 1 with the fixing clamp omitted for simplicity;
FIG. 3 shows the positioning of the bar and clamp of the present invention in a sewing machine;
FIG. 4 is a perspective view of a transmission means in accordance with the present invention;
FIG. 5 is an exploded view of the transmission means of FIG. 4 in accordance with the present invention;
FIG. 6 is a sectional view of the transmission means of FIG. 4 when the solenoid therein is not energized;
FIG. 7 is a view similar to FIG. 6 but with the solenoid therein energized;
FIG. 8 shows the transmission mechanism of the present invention in vertically mounted position; and
FIG. 9 shows a prior art sewing machine wherein the transmission mechanism thereof is horizontally mounted.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIGS. 1 and 2, there is illustrated a transmission mechanism of the present invention which comprises a specially designed base plate 1 to which a transmission means 2 is attached in a known manner. It can be seen that a bar 3 fits through three mounts 11 on the base plate 1 and also provides coupling to the carriage 7, as shown in FIG. 3. At an appropriate position an opening 13 is precisely disposed, allowing a plunger 21 of the transmission means 2 to move up and down through the opening 13 to operate the sewing machine.
There are provided four bolts 12 which are threadably disposed at each of the four corners of the base plate 1. Each of the four bolts 12 is provided with a plastic bolt head so that when the bottom of a carriage 7 (shown in FIG. 3) comes into contact with the base plate 1, the carriage 7 remains stable in a horizontal orientation thus allowing the sewing machine to operate smoothly. At an end of the base plate 1 is provided a circuit board 14 which is positioned between the base plate 1 and the carriage 7. Mounted at one end of the bar 3 is a fixing clamp 4 which in turn grips an end of a connecting rod 5. Another end of the connecting rod 5 is connected to a switch box 6. The switch box 6 is wired to the circuit board 14 for controlling actuation of the transmission means 2. Since the switch box 6 and the circuit board 14 are both constructed in a known manner and do not play a part of this invention, they will not be further described herein.
FIG. 3 particularly shows the orientation of the bar 3 and the fixing clamp 4 beneath the carriage 7 of the sewing machine.
The preferred embodiment of the present invention employs the vertically positioned transmission means 2 to replace conventional transmission means which are horizontally oriented. With reference to FIG. 4, the transmission means 2 in accordance with the present invention can be seen, which comprises an upper cover 8, a lower cover 9, and the plunger 21 that protrudes from a middle portion of the upper cover of the transmission means 2.
FIG. 5 shows the detailed structure of the transmission means 2. A solenoid 10 is mounted inside a housing 101. An iron core 15 is disposed within a center portion of the solenoid 10. The iron core 15 has a conical surface 152 and a stepped center hole. A cylindrical protrusion 81 is disposed on an inside face of the upper cover 8. The cylindrical protrusion 81 forms an oblique hole 82 on an inside surface thereof for disposing a washer 84 and a seal 85. A bushing 83 is also disposed within a central hole of the upper cover 8 for the plunger 21 to slide thereon. The plunger 21 is provided with an externally threaded portion 211 at one end thereof for threadedly engaging with the iron core 15 and receiving a nut 70. At the other end of the plunger 21 is an internally threaded portion 210, wherein a first spring 212 and a buffer ring 213 are mounted. A positioning ring 214 is threadably fixed to an end of the internally threaded portion 210 to seal the buffer ring 213 and therefore the first spring 212. A T-shaped bolt 217 is further threaded into the buffer ring 213 and a rubber disk 218 is attached on top of the T-shaped bolt 217. Below a base ring 60 is the lower cover 9 within which is provided a plastic buffer washer 72. The lower cover 9 has a central opening which allows the nut 70 to pass through. It is noted that adjustment of the stroke of the plunger 21 can be achieved by moving the nut 70 along the externally threaded portion 211 thereof.
FIG. 6 is a cross sectional view of the transmission means 2, illustrating the relative positions of each member with the solenoid 10 in the de-energized state. The solenoid 10 and the base ring 60 are disposed within the housing 101 and further encased by the upper cover 8 and lower cover 9, thus fixing the solenoid 10 within the housing 101. From FIG. 7 it can be seen that the iron core 15 is positioned in the center of the solenoid 10. The plunger 21, threaded through the center of the iron core 15, is fixed therein by the nut 70.
The base ring 60 is mounted at the bottom of the housing 101 for the iron core 15 to move freely on the central portion of the base ring 60. A second spring 19 is disposed within an upper portion of the stepped center hole of the iron core 15 with one end thereof urging the washer 84.
When the solenoid 10 is energized, as shown in FIG. 7, the iron core 15 is urged forward, or upward in the figure, by induced magnetic force so that the plunger 21 is protruded over the upper cover 8. The iron core 15 is urged forward until the conical surface 152 thereof makes contact with the oblique hole 82 of the upper cover 8. The plunger 21 moves along with the iron core 15 because the threaded engagement therebetween. The first spring 212 prevents any damage to the transmission means 2 from sudden movement. The second spring 19 is compressed at this position. When the solenoid 10 is de-energized, the second spring 19 urges the iron core 15, and hence the plunger 21, to return to their original positions, as shown in FIG. 6.
The nut 70 is used to adjust the relative position between the iron core 15 and the plunger 21 to provide different strokes of protrusion of the plunger 21 relative to the upper cover 8, as required by different sewing machines.
FIGS. 8 and 9 respectively show the vertically mounted transmission means of the present invention and the horizontally mounted transmission means of the prior art. It is noted that, as the transmission mechanism of this invention incorporates, those parts that are externally exposed to the environment to form an integral part, the total length thereof is reduced. Therefore, it can be positioned vertically because it comprises fewer outward extending parts. Moreover, all parts are encased thus preventing the harmful effects of outside dust and other contaminants.
As various possible embodiments might be made of the above invention without departing from the scope of the invention, it is to be understood that all matter herein described is to be interpreted as illustrative. Thus, the scope of the invention is to be limited only by the scope of the appended claim. | A transmission mechanism used for sewing machines equipped with a carriage comprising a base plate having an opening, a fixing clamp for mounting the base plate to the carriage, and an apparatus for transmission which can be vertically attached to the base plate under the opening thereof. The transmission apparatus has a plunger passable through the opening to perform a reciprocating movement. The transmission apparatus has all its elements substantially disposed within a housing encased by an upper cover and a lower cover thereof to form an integral piece and to reduce the total length thereof. | 3 |
TECHNICAL FIELD
[0001] This invention pertains to the field of sending and receiving electronic messages, such as e-mails, in communications networks.
BACKGROUND ART
[0002] Electronic messaging has become an essential form of communication in the age of the Internet. With the surge in usage of electronic media, such as e-mail, an increased burden has been placed on the resources needed to manage this data traffic, including data storage devices. Efficiencies in this area have come from many sources, including the technology described in the invention protected by U.S. Pat. No. 5,815,663 (Distributed posting system using an indirect reference protocol), referred to herein as “dynamic content”.
[0003] One shortcoming of dynamic content technology, as applied to e-mail, is that all mail sent to multiple recipients assumes that recipient mail clients are enabled to read dynamic content mail. The present invention removes this requirement by moving the responsibility of dealing with dynamic content out of the mail client and into the outbound-and inbound mail servers. Thus, all mail clients are now able to participate in the advantages of dynamic content without requiring any modifications to the client.
DISCLOSURE OF INVENTION
[0004] This invention eliminates redundant electronic messages in a network caused by copying a message to multiple recipients without requiring code changes in the messaging client code. Specifically, a message sent by a user messaging client, such as an e-mail client, is received by a receiving server, such as an SMTP server, which then stores the message content with a content server. The content server returns a pointer to the content, as described in U.S. Pat. No. 5,815,663, which the receiving server then may insert into the message header, in place of the message content, before sending the message to the message recipients. When a recipient receives a message and wishes to read it, the associated inbound messaging server, such as an IMAP or POP mail server, uses the pointer contained in the message to retrieve the message content and return it to the recipient.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] These and other more detailed and specific objects and features of the present invention are more fully disclosed in the following specification, reference being had to the accompanying drawings, in which:
[0006] FIG. 1 is a flowchart illustrating a process of reading a message according to the present invention.
[0007] FIG. 2 is a flowchart illustrating a process of sending a message according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0008] The preferred implementation is for electronic mail and includes an SMTP server, and IMAP server (collectively, “mail servers”) and a content server communicating with the mail servers via HTTP. In all that follows, our preferred implementation is based on the Apache James Server (see http://james.apache.org/ for details), modified to support the functionality as described herein. We define the operation of the outbound-(SMTP) and inbound (IMAP/POP) servers separately.
[0000] SMTP server
[0009] When a message is sent to the SMTP server, the server first checks to see which of the recipients are to be sent dynamic content; for example, this could be done via a configuration option. For recipients who are NOT to receive dynamic content, the server simply performs the usual SMTP functions and forwards the message to the appropriate mail relay server for that recipient. If the recipient is to receive dynamic content, the SMTP server sends to the content server one RECEIVE CONTENT request for each content component in the message and the content server returns pointers to the locations of the respective content components on the server; see the Appendix for the format of the RECEIVE CONTENT request. The pointer information includes numeric values corresponding to the content components in the content server database. This pointer information, along with the name and port number of the content server, are added to the mail message header and the header is sent to the recipient. Note that the message body is empty, in this implementation.
[0010] See FIG. 2 : Sending a message.
[0000] IMAP/POP server
[0011] When a user of a mail client wishes to view a mail message in the user's inbox, the user typically selects the message to be viewed from within a window that displays certain summary information about the message, such as the date received, the sender e-mail address or name, and the message subject. The mail client sends a request to the IMAP or POP server to retrieve the message body and this in turn causes the IMAP/POP server to query the message header for dynamic content information. If there is none, it is assumed that the message requested does not contain dynamic content and the IMAP or POP server performs the usual function of fetching and returning the content. If the pointer information is present, it is retrieved and used to format a FETCH CONTENT request (described in the Appendix) to the content server, who returns the desired content. Similarly, if a dynamic content attachment is selected for viewing, the pointer for the attachment is used in the FETCH CONTENT request.
[0012] See FIG. 1 : Reading a message.
[0013] The above description is included to illustrate the operation of the preferred embodiments, and is not meant to limit the scope of the invention. The scope of the invention is to be limited only by the following claims. From the above discussion, many variations will be apparent to one skilled in the art that would yet be encompassed by the spirit and scope of the present invention. | A method is presented for reducing the total amount of disk space used by multiple recipients of an electronic message in a network. | 7 |
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of our copending U.S. patent application Ser. No. 07/367,261 filed June 16, 1989, which issued as U.S. Pat. No. 4,961,953 on Oct. 9, 1990 which was a continuation of our U.S. patent application Ser. No. 07/127,955, filed Dec. 2, 1987, now abandoned, which, in turn, was a continuation-in-part of our U.S. patent application Ser. No. 06/606,959 filed May 4, 1984, which issued as U.S. Pat. No. 4,734,287 on Mar. 29, 1988.
BACKGROUND
The present invention relates to reduced fat yogurt compositions which include a microparticulated protein product as described in our allowed U.S. Pat. No. 9,961,953 the entire disclosure of which is incorporated by reference herein.
SUMMARY OF THE INVENTION
The present invention is a reduced fat yogurt having all or part of the fat and/or oil content normally found in yogurt replaced with a proteinaceous, water-dispersible, macrocolloid comprising substantially non-aggregated particles of denatured protein having in a dry state a mean diameter particle size distribution ranging from about 0.1 to about 2.0 microns, with less than about 2 percent of the total number of particles exceeding 3.0 microns in diameter, and wherein the majority of the said particles are generally spheroidal as viewed at about 800 power magnification under a standard light microscope, the particles in a hydrated state form said macrocolloid having substantially smooth, emulsion-like organoleptic character.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a photomicrographic view at 1000× magnification of microparticulated whey protein of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
The following examples relate to preferred methods and procedures for practicing the present invention. Example 1 relates to a preferred method for the production of microparticulated protein from the proteinaceous material present in acidified whey. Example 2 relates to a preferred method for the production of microparticulated protein from casein micelles and the proteinaceous material present in egg white. Example 3 relates to the production of microparticulated protein from the proteinaceous material in whey. Example 4 relates to the preparation of a sundae style reduced fat yogurt. Example 5 relates to the preparation of a swiss style reduced fat yogurt.
EXAMPLE 1
Microparticulated Protein Produced From Acidified Whey
Microbiologically, aromatically and particulately clean water produced by a reverse osmosis process is added to a sanitary tank.
Commercially available liquid whey protein concentrate is treated by ultrafiltration and evaporation until the concentration of protein is about 50-55% by weight, on a dry basis. The whey protein concentrate is added to the water in the sanitary tank with agitation avoiding aeration through the suction side of a positive displacement pump to achieve a solids concentration of about 37% solids for the mixture.
As this mixture is recirculated back to the sanitary tank, a dilute solution of food acid (acetic, lactic, citric or hydrochloric; alone or in combination) is added through an in-line mixer to lower the pH from about 6.8 to about 4.4±0.05.
The pH adjusted mixture is then rigorously deaerated in a Versator deaerator/homogenizer and bottom fed into a holding tank which is equipped for non-aerating agitation.
The deaerated mix is then pumped (300 lbs/hr) from the holding tank, by a positive displacement pump through an in-line strainer (300 μm cheesecloth) and a mass flow meter, into a plate heat exchanger which heats the mixture to about 165°-180° F., a temperature lower than the target peak temperature which is achieved within a heat and shear generating apparatus ("microcooker"). Flow is manually-controlled based on readings from the in-line flow-meter.
The heated mixture is pumped directly from the plate heat exchanger into the microcooker apparatus as described in U.S. Pat. No. 4,823,396 with the exception that the inlet and outlet ports have been interchanged or exchanged, i.e., the inlet port is disposed where the outlet port is shown in the patent drawing and the outlet port is located at the bottom of the bowl shaped vessel and the temperature of the mixture is raised to about 200° F. within less than 10 seconds under high shear conditions. Rigorous temperature control of the mixture is maintained at 200° F. by means of a cascade control loop. The control loop senses the temperature of the product exiting the microcooker and maintains it at 200° F. by adjusting the temperature of the mixture leaving the plate heat exchanger.
The speed of the rotor in the microcooker is held constant, for example, at about 3715 rpm. At this rpm, the shear rate is about 27,000 reciprocal seconds at the tips of the rotor which has a diameter of approximately 7 inches.
After exiting the microcooker apparatus, the product flows directly into an eccentric scraped surface heat exchange and is cooled with vigorous agitation to less than 130° F. The cooled product then flows through additional heat exchangers (scraped surface of plate type) to reduce its temperature to less than 55° F.
EXAMPLE 2
Microparticulated Protein Produced from Casein Micelles and Egg White
Microbiologically, aromatically and particulately clean water (16.83 wt. %) produced by a reverse osmosis process is heated in a sanitary tank to about 120° F.
Commercially available apple pectin (0.35 wt. %) dry-blended with sugar (5.0 wt. %) to assure its complete dispersion and is then added to the water in the sanitary tank by means of a high shear solid/liquid Triblender mixer. This mixture is held at about 120°-140° F. with agitation for about 5 minutes to assure hydration and dissolution of the pectin. The mixture is then cooled to less than about 100° F.
Liquid egg white is ultrafiltered using membrane filters having a molecular weight cut-off of about 10,000. The ultrafiltration reduces the total volume of the liquid egg white by about 50% and effectively doubles the protein content and halves the sodium content of the egg white. The treated egg white (55 wt. %) is added to the pectin solution through the suction side of a positive displacement pump with controlled agitation to avoid aeration.
Condensed skim milk (22.65 wt. %) is then added to the mixture through the suction side of a positive displacement pump.
As this mixture is recirculated back to the sanitary tank, a dilute solution of food acid (0.17 wt. %) (acetic, citric, lactic or hydrochloric; alone or in combination) is added through an in-line mixer to lower the pH from about 7 to about 6.20±0.05.
The pH adjusted mix is then rigorously deaerated in a Versator deaerator and bottom-fed into a holding tank which is equipped for non-aerating agitation.
The deaerated mixture is then pumped (600 lb/hr) from the holding tank, by a positive displacement pump through an in-line strainer (300 μm cheesecloth) and a mass flow meter into a plate heat exchanger which heats the mixture to about 165° F., a temperature lower than the target peak temperature which is achieved within the microcooker apparatus described in Example 1. At this lower temperature no coagulate will have developed. Flow is manually-controlled based upon readings from the in-line flow-meter.
The heated mixture is pumped directly from the plate heat exchanger into the microcooker apparatus and the temperature of the mixture is raised to about 185° F. within less than about 10 seconds under high sheer conditions. Rigorous temperature control is maintained over the temperature of the mixture in the microcooker apparatus by a cascade control loop. The control loop senses the temperature of a product exiting the microcooker and holds the temperature constant by regulating the temperature of the mixture leaving the plate heat exchanger.
The speed of the rotor in the microcooker is held constant at about 5400 rpm. At this rpm, the shear rate is about 40,000 reciprocal seconds at the tips of the rotor which has a diameter of approximately 7 inches.
After exiting the microcooker apparatus, the product flows directly into an eccentric scraped surface heat exchanger and is cooled with vigorous agitation to less than 130° F. The cooled product then flows through additional heat exchangers (scraped surface or plate type) to reduce its temperature to less than 55° F.
EXAMPLE 3
Microparticulated Protein Produced From Whey
Commercially available liquid whey is treated by ultrafiltration and evaporation to give a mixture having about 42% by weight solids and about 50%-55% by weight protein, on a dry basis. The resulting whey protein concentrate is deaerated in a Versator deaerator and bottom fed into a sanitary tank equipped for a non-aerating agitation.
The deaerated mixture is then pumped (600 lbs/hr), by a positive displacement pump through an in-line strainer (300 μm cheesecloth), a mass flow meter and plate heat exchanger which raises the temperature of the mixture to about 170° F., into a heated holding device.
The heated holding device includes two concentric scraped surface heat exchangers connected in series. Each heat exchanger provides a hold time of about 3.6 minutes at a flow rate of about 300 lbs/hr. Both of these heat exchangers are heated to maintain the hold temperature set by the plate heat exchanger.
The mixture is then pumped from the holding device to an eccentric scraped surface heat exchanger. This scraped surface heat exchanger cools the mixture to a temperature of about 165° F., a temperature lower than the target peak temperature inside a heat and high shear generating apparatus (microcooker). The mixture then flows directly into the microcooker apparatus as described in Example 1 and the temperature of the mixture is raised to 200° F. within 10 seconds under high shear conditions. Rigorous temperature control at 200° F. is maintained in the microcooker by a cascade control loop. The control loop senses the temperature of a product exiting the microcooker and holds the temperature constant by regulating the temperature of the mixture leaving the eccentric scraped surface heat exchanger.
The speed of the rotor in the microcooker is held constant at about 5200 rpm. At this rpm, the shear rate is about 40,000 reciprocal seconds at the tips of the rotor which has a diameter of approximately 7 inches.
After exiting the microcooker apparatus, the product flows directly into an eccentric scraped surface heat exchanger and is cooled with vigorous agitation to less than 130° F. The cooled product then flows through an additional heat exchanger (scraped surface or plate type) to reduce its temperature to less than 55° F.
EXAMPLE 4
Preparation of a Sundae Style Reduced Fat Yogurt
A sundae style reduced fat yogurt was prepared from the ingredients shown in Table 1.
TABLE 1______________________________________Sundae Style Reduced Fat YogurtIngredients Wt. % of Composition______________________________________Skim Milk 91.57Nonfat Dry Milk 3.53Microparticulated Protein 2.94(Example 3)Starter Culture System 1.96(Chris Hansen CH.sub.3 inoculum)______________________________________
The skim milk was heated to about 100°-120° F. in a steam jacketed kettle. Nonfat dry milk and the microparticulated protein prepared as described in Example 3 were added to the heated skim milk and the temperature was increased to about 160° F. The heated mixture was then homogenized at 2500 psi in a first stage and then at 500 psi in a second stage. The homogenized mixture was then pasteurized at 195° F. for 5 minutes, at 185° F. for 30 minutes or, at 203° F. for 6 minutes. The mixture was cooled to about 108°-115° F., the inoculum was added, the inoculated mixture was filled into individual cups and then incubated for about 3.5 hours until the pH reached a value of 4.6. After incubation, the cups were cooled to about 38°-45° F.
EXAMPLE 5
Preparation of a Swiss Style Reduced Fat Yogurt
A swiss style reduced fat yogurt was prepared from the ingredients listed in Table 2 and following the procedures set forth in Example 4 provided that before the inoculated mixture was added to individual cups the inoculated mixture was incubated for 3.5 hours until the pH reached a value of 4.6, and the cultured mixture was then stirred to break the coagulum. The broken coagulum was pumped through a sour cream value into individual cups containing the fruit preparation and the undisturbed cups were cooled to about 40° F.
TABLE 2______________________________________Swiss Style Reduced Fat YogurtIngredient Wt. % of Composition______________________________________Cultured Skim Milk with starter 76.40culture systemNonfat Dry Milk 1.63Fruit Preparation 15.00Microparticulated Protein 4.25(Example 3)Sugar 1.7Modified Food Starch 0.85Gelatin 0.17______________________________________
Numerous modifications and variations in practice of the invention are expected to occur to those skilled in the art upon consideration of the foregoing descriptions of preferred embodiments thereof. Consequently, only such limitations should be placed upon the scope of the invention as appear in the appended claims. | The present invention provides yogurt formulated with microparticulated protein which serves as a replacement for all or part of the fat and/or oil normally found in yogurt. | 8 |
ORIGIN OF THE INVENTION
The invention described herein was made in the performance of work under a NASA contract and is subject to Public Law 96-517 (35 U.S.C. §200 et seq.). The contractor has not elected to retain title to the invention.
This is a division of application Ser. No. 553,339, filed 11/18/83 now U.S. Pat. No. 4,526,925.
TECHNICAL FIELD
This invention relates to vinyl pyridine group-containing compounds and oligomers, their advantageous copolymerization with bismaleimide resins, and the formation of reinforced composites based on these copolymers.
BACKGROUND
Bismaleimides are being increasingly used as matrix resins for fiber-reinforced composites, especially high-performance graphite fiber-reinforced composites. The monomers are cured by a thermally induced addition reaction to give highly crosslinked, void-free network polymers having good physical properties with higher thermal stability, higher clear yield, better fire resistance and lower water absorption than currently-used epoxy systems.
There are problems with maleimides, however, such as solvent retention in the prepregs, high temperatures often needed for curing with attendant distortion and high cost, and the brittleness of the polymers due to the high crosslink density obtained in network polymers. Brittleness can be such a problem that a single minor impact can greatly reduce the strength of a maleimide-based composite. These problems have prevented the wide application of the carbon-reinforced maleimides in aircraft primary and secondary structures where their high strength and fire resistance is much sought after.
A number of methods have been proposed to minimize some of the aforesaid problems. For one, the basic maleimide structure can be modified. For another, the bismaleimides can be copolymerized with comonomers. The present invention concerns vinyl pyridine group-containing compounds and their incorporation as comonomers into bismaleimide resins. One of the types of vinyl pyridine group-containing compounds has a vinyl styrylpyridine structure, i.e., a ##STR1## wherein n is 1 to 10, each of the R 1 is hydrogen or lower alkyl and R 2 is an organic group. U.S. Pat. No. 4,362,860 of Ratto et al discloses such materials as well as the materials where R 2 is hydrogen as thermosetting polymers but does not suggest their copolymerization with bismaleimide. Rockwell International's Final Report (Phase I) (Aug. 18, 1980-Nov. 30, 1981) in NASA contract NAS2-10709 further discusses the Ratto et al findings where R 2 is hydrogen and shows that the one step synthesis route it discloses gives a mixture product which must be fractionated to obtain the desired vinyl styrylpyridine materials.
U.S. Pat. No. 3,810,848 and '872 disclose a family of complex-forming polymers having ##STR2## wherein L is a covalent bond or O, S, CO, CHR or NR and R is hydrogen or an alkyl. At Example 6, U.S. Pat. No. 3,180,848 shows condensing such a polymer with a pyromellitic anhydride to give a maleimide-like copolymer structure. Another patent of interest is U.S. Pat. No. 3,994,862 of Ropars, et al. which discloses condensation products of trimethylpyridine with aromatic aldehydes to give prepolymers which differ from the present vinyl-terminated styrylpyridines in not having the vinyl terminis. Ropars, et al. also does not show copolymers with bismaleimides.
STATEMENT OF THE INVENTION
It has now been found that the properties of bismaleimide resins and their preparation conditions are substantially improved by incorporating with the bismaleimide resins, as copolymeric units, the vinyl pyridine 5-vinyl-2-stilbazole of the structure ##STR3## and/or the vinyl styrylpyridine oligomer of the structure ##STR4## wherein R and R 1 are independently selected from hydrogen, aryls, lower alkyls, alkoxy and halos, R 1 is hydrogen or lower alkyl, and R 2 is a 1 to 4 carbon organic group.
In another aspect, this invention provides the vinyl stilbazole materials as novel comonomers.
In a further aspect, this invention provides composites made of the bismaleimide resin copolymers cured with a reinforcing amount of reinforcing fiber. The copolymer resins can be applied as solvented "varnishes" or very advantageously as "hot melts".
In an additional aspect, the invention provides a high yield two step synthetic path to the vinyl styrylpyridine oligomer (II).
Yet another aspect of this invention concerns a low temperature cure process for the bismaleimide resins in which the above-described copolymers are cured at temperatures of from about 130° C. to 230° C.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be described with reference being made to the accompanying drawing in which
FIG. 1 is a differential scanning calorimeter plot of the relative cure temperatures of the copolymers of this invention and the individual monomers alone.
DETAILED DESCRIPTION OF THE INVENTION
Vinyl stilbazole
The vinyl stilbazole materials of this invention have the structure ##STR5## wherein each of R and R 1 are independently selected from hydrogen, lower alkyls, alkoxies, aryls and halos, i.e., 1 to 4 carbon alkyls and alkoxy, chloros, iodos, bromos, phenyls and alkyl phenyls of 7 to 9 carbons and the like, especially methyl, ethyl, isopropyl, methoxy, ethoxy, chloros, and phenyl. Preferably at least one and more preferably both of R and R 1 are hydrogens.
Such materials are prepared by condensing 5-vinyl-2-methyl pyridine with an appropriately R and R 1 -substituted benzaldehyde under dehydrating conditions as follows: ##STR6## This reaction can be carried out neat, since the reactants are solvents for one another. A nonaqueous inert solvent such as DMF, glacial acetic acid, NMP (N-methylpyrolidone), DMAc or DMSO could be used if desired. The dehydration conditions are suitably provided by acetic anhydride, optionally in combination with acetic acid and/or a catalyst like ZnCl 2 to activate the methyl groups. The condensation is carried out at a temperature of from about 50° C. to about 140° C. Higher temperatures are generally to be avoided as they may lead to some degree of polymerization of the product. The reaction is not rapid at these temperatures, generally requiring at least about 4 hours and preferably 6 to 60 hours. The reaction is preferably carried out in the substantial absence of oxygen--either under reduced pressure or under an inert atmosphere like nitrogen or argon. Usually, about equimolar amounts (i.e., from 1 to 1.1 to about 1.1 to 1 moles) of the vinyl pyridine and the aldehyde are employed. An excess of one material or the other could be employed, but the excess would only have to be removed from the final product.
Vinyl styrylpyridine oligomers
The vinyl styrylpyridine oligomer materials have the structure ##STR7## wherein n is an integer from 1 to 10, most advantageously 1 to 4, R 1 is hydrogen or a lower alkyl of 1 to 4 carbons, especially hydrogen or methyl, but more especially, hydrogen; and R 2 an organic group such as is a 1 to 4 carbon alkyl, or a 1 to 4 carbon alkoxy, a halo-substituted 1 to 4 carbon alkyl, such as, for example, methyl, ethyl, propyl, butyl, methoxy, ethoxy, 2-chloroethyl, chloromethyl. R 2 is especially a methyl or methoxy.
The structure II is an "average" structure and is provided to show a representative structure at the A and B rings. The exact substitution patterns on the A and B rings can vary. The A rings should have their two double bonds in a "1,3" (meta) or "1,4" (para) configuration. The B rings should have their two olefin groups i.e. "vinyl" groups and R 2 in a "2,6-divinyl-4-R 2 " or a "2,4-divinyl-6-R 2 " configuration.
These oligomeric materials are prepared by the two step process of (1) condensing a 2,6-dimethyl-4-R 2 -pyridine or a 2,4-dimethyl-6-R 2 -pyridine such as collidine, or the like with an R 1 -substituted aromatic dialdehyde such as an "R 1 -substituted" terephthaldehyde under dehydrating conditions and in the absence of a vinyl pyridine and (2) thereafter treating the reaction product with 5-vinyl-2-methylpyridine again under dehydrating conditions, for example: ##STR8## In the first step of this reaction the number of equivalents of aldehyde should be greater than the number of equivalents of methyl groups on the 2 and 4 or 2 and 6 positions on the dimethyl-R 2 -substituted pyridine, preferably from 1.0 to 1.5 times the number of 2,4 or 2,6 methyls. In the second step the combined equivalents of 2,4 or 2,6 methyls plus vinyl methylpyridine is larger than the total equivalents of aldehydes (i.e., from 1.0 to 2.0 times). As with the stilbazole materials, a catalyst like ZnCl 2 can be present if desired. The temperature for reacting the collidine or the like with the dialdehyde may be selected in the range of about 130° to 190° C., preferably 140° to 180° C. and more preferably about 160° C. for times of 1-40, especially 1-20 hours. An inert oxygen-free atmosphere is preferred. The coupling of vinyl methylpyridine to residual aldehyde groups is carried out at somewhat lower temperatures, e.g., 80° to 130° C., preferably 80° to 120° C. and especially about 110° C. again for 1 to 40, and especially 1 to 20 hours, preferably in an inert atmosphere. The dehydrating conditions are achieved by having a water acceptor such as an acid anhydride, e.g. acetic anhydride, in the reaction zone or by permitting the water that is formed to evaporate. This two step process has the advantage of allowing precise control of each of the two reactions. In comparison to the one step process of Ratto et al U.S. Pat. No. 4,362,860, this process gives a more reproducible product in higher yield.
The Bismaleimides
The bismaleimide is represented structurally by the formula ##STR9## wherein R* and R** independently are hydrogen or a 1 to 4 carbon alkyl. Preferably R* and R** are hydrogen or CH 3 and more preferably at least one of the groups is hydrogen. L Or is a covalent organic linking group, that is a bivalent organic group containing in its structure an aliphatic chain or at least one aromatic ring. Many suitable examples of these bismaleimides are available commercially. They are prepared synthetically by a sequenced addition of a diamine to maleic anhydride followed by cyclization. Bismaleimide materials can be drawn from resins having as L Or simple ##STR10## aromatic rings as were used in the pioneering Gemon resins sold by General Electric, and ##STR11## aromatic rings as are found in commercial Kerimid 353 and Kerimid 601 resins of Rhone-Poulonc to more involved materials such as Technochemie's H-795 resin: ##STR12## wherein R is an aromatic ring and X-R 1 -X is a Michael addition coupling group Technochemie's M-751 resin which is an "eutectic" mixture of ##STR13## In general, L Or can be any organic linking group that is relatively inert, that permits the bismaleimide to be intimately admixed with the vinyl pyridine material either by melting or by dissolving in a common solvent and that does not interfere with the reactivity of the maleimide units. The M-795 type bismaleimides offer the advantage of working well in hot-melt systems.
Copolymers
The copolymers of this invention are composed of the vinyl styrylpyridine oligomers and/or vinyl stilbazole copolymerized with one or more bismaleimides. The properties of the cured composite will depend in part of the relative amounts of the vinyl styrylpyridine oligomers and/or vinyl stilbazole and the bismaleimide. As the proportion of vinyl stilbazole is increased, the product becomes less flame-resistant when fully cured but easier to cure. As the proportion of the vinyl stilbazole is increased, a more amorphous, less brittle, less crystalline, tougher product is achieved, but one which has decreased flame retarding because of lesser char yield on pyrolysis.
With vinyl stilbazole the preferred maximum proportion of stilbazole is about 2 moles per mole of bismaleimide since under the usual cure conditions the vinyl group on the stilbazole reacts with the bifunctional maleimide. With the vinyl styrylpyridine oligomer materials, any proportion can be employed. In general, however, it is desired to have a cured product with good flame retardency and thus to employ at least about one mole of bismaleimide per mole of vinyl styrylpyridine and/or vinyl stilbazole. To achieve the improved product properties, it is generally desired to use at least about 0.05 moles of vinyl stilbazole or vinyl styryl pyridine per mole of bismaleimide. On a weight basis, it is preferred to employ maleimide to vinyl pyridine ratios of 15:1 to 1:1, especially 10:1 to 2:1.
Cured Products
The cured resins of this invention find ready use as moldable plastics and especially as binders or substrates for reinforced composites. The reinforcement is generally a fiber and can be organic or inorganic and in organized or disorganized form, for example carbon fiber, aramide fiber or glass fiber as yarns, fabrics, or felts; or such material as chopped fiber. Other materials known in the art as polymer reinforcements, for example boron nitride, and metal fibers, can be employed as well. Carbon fibers is the preferred reinforcement.
Conventional ratios of reinforcement to substrate are employed, such as from about 0.5 to about 5 parts by weight of reinforcement per part of substrate.
Other materials such as fillers, pigments, antioxidants and the like can be added as well, if desired.
Copolymer Formation and Cure
It is an important advantage of the present copolymers that their cure conditions are far less severe than those employed with the bismaleimides alone. Thus, it is less expensive to cure the present materials and less distortion occurs during cure. It is also an important advantage that the present copolymers, as they cure, do not give off volatile components which can generate voids and decrease the strength of the final cured products.
Copolymers are formed by admixing the bismaleimides and the vinyl styrylpyridine oligomer and/or vinyl stilbazole in the desired ratio and heating. The mixing can be carried out in a polar organic solvent such as chloroform, tetrahydrofuran, dichloroethane, ketones such as acetone, methyl ethyl ketone, and the like, or it can be carried out using a hot melt of the next copolymer components. This liquid mixture (or varnish) is mixed with the reinforcement, by dipping, coating or the like. Any solvent is preferably removed prior to cure to avoid voids created by solvent volatilizing from partially cured resin.
A typical cure cycle for a copolymer might employ 110°-170° C. to remove solvent if present (or lower temperature if vacuum is applied) and 130° to 230° C. for curing. In general the copolymers of vinyl stilbazole materials cure at lower temperatures, i.e., 130°-190° C. than do the vinyl styrylpyridines which usually require 160°-230° C. Such temperatures are far lower than required for the bismaleimides alone. This can be shown experimentally using a differential scanning calorimeter which measures heat flow and can detect when the exothermic curing reactions take place. Three experiments were carried out in such a calorimeter and their results are given in FIG. I.
First, a bismaleimide (Technochemie H795) was placed in the unit and heated. The peak heat flow--indicating maximum curing rate required was 282.4° C. Second, vinyl stilbazole alone was tested. No distinct cure peak was detected even up to and over 400° C. In the third experiment 3 parts by weight of vinyl stilbazole was mixed with 7 parts weight of Technochemie H795 resin. The cure temperature observed was 164° C., as shown in FIG. 1. With copolymers of vinyl styrylpyridine the cure peak would be about 200° C. These substantially reduced curing temperatures offer advantages of less distortion and/or shrinkage during cure and lower energy requirements.
The copolymers of this invention are formed into castings or molded products by conventional processes. They can be formed into reinforced structural bodies by any of the methods known in the art including pressure forming, hand lay-up, pull-truding, filament winding, vacuum laminating and the like and the invention is not to be construed as limited to any particular forming technique.
Using a representative pressure molding technique with a solvated vinyl styrylpyridine bismaleimide copolymer one might employ the melting/solvent stripping/cure cycle shown in Table I.
TABLE I______________________________________Mode Temperature Pressure Time______________________________________Heat-solvent removal 150° C. 0 20 minor melt mixturefrom hot meltHeat and Press 180° C. 75 psi 10 minHeat and Press 190° C. 100 psi 40 minHeat and Press 200° C. 100 psi 200 min______________________________________
Infrared analysis of a material cured by such a schedule shows that it contains the internal double bonds of the original feedstock and that they have not polymerized. This is important to fire resistance as these bonds are available to react during pyrolysis to form additional organic rings as needed for char formation.
In general, one does not have to employ curing agents or catalysts with the present resin systems. It is often desired to not have curing take place during solvent removal so as to minimize or avoid forming voids due to the solvent release in the cured body or to maximize pot life of a melt in which case one would prefer to not have a catalyst present. If this is not considered a problem, as might be the case with injection molded parts, any conventional peroxide or other free-radical initiator can be employed as catalyst.
The invention will be further described by the following preparations and examples. These are provided to illustrate the invention and are not to be construed as limiting its scope which is instead defined by the claims.
Preparation I
Two Step Preparation of Vinyl Terminated Polystyrylpyridine
Step 1: 18.0 g (0.3 mole) of acetic acid, 30.6 g (0.3 mole) of acetic anhydride, 20.1 g (0.15 mole) of terephthaldehyde, and 12.1 g (0.1 mole) of collidine were placed in a 500 ml, 3-necked round-bottom flask equipped with a mechanical stirrer and a reflux condenser. After the reaction solution was deoxygenated, the flask was immersed in an oil bath and the reaction solution was heated at 130° C. to 170° C. for several hours. Step 2: The reaction solution was cooled to room temperature and 17.9 g (0.15 mole) of 5-vinyl-2-methyl pyridine was added. The solution was degassed again and heated to 80° C.-120° C. for several hours. The reaction mixture was then poured into 10% NaOH solution. The brownish viscous product was washed with 10% NaOH solution, then with de-ionized water until the aqueous layer tested neutral. All the water was decanted and the product was dissolved in THF and filtered. The filtrate was then poured into large quantity of de-ionized water to precipitate out VPSP (II). This purification was repeated several times. Finally, the product was dried in vacuum and stored in THF. For hot melt applications, the product could be stored neat.
Preparation II
Preparation of Vinyl Stilbazole
50.0 g (0.42 mole) of 5-vinyl-2-methyl pyridine, 44.6 g (0.42 mole) of benzaldehyde, 25.2 g (0.42 mole) of acetic acid, and 42.9 g (0.42 mole) of acetic anhydride were placed in a 1000 ml, 3-necked round-bottom flask equipped with a mechanical stirrer and a reflux condenser. After the reaction solution was deoxygenated, the flask was immersed in an oil bath and the reaction was held at 80° C.-120° C. for several days. The reaction solution was then cooled to room temperature and poured into a large beaker containing 10% NaOH solution. The mixture was stirred for half an hour and the aqueous layer was decanted. The brownish viscous product was washed several timed with 10% NaOH solution, then with deioized water until the aqueous layer tested neutral. All the water was decanted and the product was dissolved in THF and filtered. The filtrate was then poured into large quantity of de-ionized water to precipitate out vinyl stilbazole. This purification was repeated several times. Finally, the brownish product was dried in vacuum, weighed and transferred into a storage container using THF as solvent. For hot melt applications, the product could be stored neat.
EXAMPLE 1
A maleimide copolymer was prepared as follows: 1 part by weight of vinyl stilbazole (VST) as prepared above and 4 parts of Technochemie H795 bismaleimide resin was dissolved in THF. The THF was removed to give an intimate mixture of the two comonomers. A portion of this material was placed in a differential scanning calorimeter and gradually heated to detect the cure temperature of 197° C. The cure material's glass-transition temperature (Tg) was determined to be 380° C. and its polymer decomposition temperature in N 2 was seen to begin at 400° C. The material had a high char yield (43% at 800° C.) indicative of excellent flame retarding properties. It had a composite modulus at 25° C. of 15 GPa and 12 GPa at 300° C.
A series of other copolymers based on H795 bismaleimide and the varying amounts of the above-described VST or vinyl styrylpyridine (VPSP) were prepared and similarly tested and compared with a currently favored epoxy and the bismaleimides alone. The results which demonstrated the advantages of the present invention are given in Table II.
TABLE II______________________________________ Cure CHAR Tempera- PDT YIELD ture (DSC Tg (N.sub.2) at 800RESIN SYSTEM PEAK), °C. °C. °C. %______________________________________EPOXY (MY720) 255 250 300 30BISMALEIMIDE (H795) 282 >400 400 42COPOLYMERS:VST:H795 = 1:4 197 380 400 43VST:H795 = 3:7 164 400 36VPSP:H795 = 1:9 245 >400 400 43VPSP:H795 = 1:4 230 >400 400 50VPSP:H795 = 3:7 226 400 400 55______________________________________
EXAMPLE 2
Another portion of the various copolymers of Example 1 were formed into graphite-reinforced composites.
In a typical preparation 9 ply satin-weave graphite fiber cloth was heated at 310° C. overnight to remove sizing in air. The resin system, for example VST/H795 3:7 by weight was dissolved in THF and brushed on the fiber:
Fiber weight--245 g.
Fiber coating weight--405 g.
Excess resin (47 g) was removed when the fiber was lightly pressed to give a resin content of 31.5%. The product was press cured as follows:
1. No pressure--heated to 250° F. for 10 min to remove solvent.
2. No pressure--heated to 320° F. for 10 min to complete solvent removal.
3. At 75 psi--heated to 356° F. for 10 min.
4. At 100 psi--heated to 374° F. for 40 min.
5. At 100 psi--heated to 392° F. for 200 min.
6. Cool to room temperature with pressure.
The properties of the composite as well as other similar composites made with other copolymer systems were evaluated and compared with H795 and VPSP alone. The results are shown in Table III.
The composites of this invention find especially advantageous application in structures which are exposed to extreme environments. They may be formed into primary and secondary structures for aircraft, spacecraft and the like (e.g. panels, wing spars and the like) where their high performance thermal behavior is such as to minimize human risks.
TABLE III__________________________________________________________________________MECHANICAL PROPERTIES OF VST, VPSP/BMI COPOLYMERCOMPARED WITH H795 GRAPHITE COMPOSITES RESIN SYSTEM WITH 9 PLY SATIN-WEAVE GRAPHITE FIBERPHYSICAL & MECHANICAL VPSP/H795 VST/H795 VPSP/H795 VST/H795PROPERTIES H795 1:4 1:4 3:7 3:7 VPSP__________________________________________________________________________RESIN CONTENT % 30.5 26 30 30.2 31.5 26DENSITY, g/cc 1.55 1.43 1.39 1.4 1.39 1.44LOI (4 PLY SAMPLE) 52 62 46 55 45 57WATER ABSORPTION, % 0.72 1.17 0.99 1.20 0.86 1.362 hrs BOILING WATERSHORT BEAM SHEAR 1.7 2.95 2.96 2.7 2.89 3.15R.T. KSIR.T. FLEXURAL 7.7 7.3 7.3 7.4 7.4 7.6MODULUS, MSISTRENGTH, KSI 24 41 46 44 41 49FLEXURAL, 100° C. 5.8 7.1 6.9 7.0 6.3 --MODULUS, NSI HOT-WETSTRENGTH, KSI HOT WET 24 37 44 40 37 --YOUNG'S MOD, GPa25° C. 15 15.5 13 15 15 --300° C. 14 15 12 14 13.5 --__________________________________________________________________________ | Vinyl pyridines including vinyl stilbazole materials and vinyl styrylpyridine oligomer materials are disclosed. These vinylpyridines form copolymers with bismaleimides which copolymers have good fire retardancy and decreased brittleness. The cure temperatures of the copolymers and substantially below the cure temperatures of the bismaleimides alone. Reinforced composites made from the cured copolymers are disclosed as well. | 2 |
PRIOR APPLICATION
Pursuant to 37 C.F.R. § 1.78(a)(4) and 35 U.S.C. § 119(e), this application claims the benefit of U.S. Provisional Application Ser. No. 60/430,399, filed Dec. 3, 2002.
TECHNICAL FIELD
This invention relates generally to display devices and, more particularly, to a display device with a rear-illuminated display area.
BACKGROUND ART
Various types of display devices are known in the art for advertisements, signs, attractions, and the like. Display devices typically have a display area which displays graphics, pictures, characters, words, etc. of interest. Many display devices have an associated illumination means for illuminating the display area for enhancing its visibility in low lighting conditions or to make it more appealing and attention-catching to observers. Some illuminated display devices have certain portions of the display area illuminated more or differently to highlight or direct more attention to those particular portions.
The various types of illumination means known in the art for illuminating display areas of display devices vary in how they illuminate the display area. Some simply comprise a light source, such as a light bulb or a fluorescent light, directing light at the surface of the display area. Others have an at least partially translucent display area with a light source disposed behind it, whereby light from the light source passes through the at least partially translucent display area and illuminates it. Such rear-illuminated display devices, however, have drawbacks. The light source usually projects a strong bright spot, sometimes termed as a hot spot, at the location of the light source behind the display area. Further, there is a gradient of decreasing light in a direction away from the light source on the remainder of the display area. Such inconsistent illumination, particularly the hot spots at the location of the light source, project an unappealing visual impression on an observer and are therefore undesirable.
Solutions that have been proposed for this problem have shortcomings. For example, fiberoptic weaves or meshes disposed under the display area provide inconsistent illumination, and are usually unable to provide an adequate amount of illumination because of the limited amount of light they can carry and deliver. Light bulbs and fluorescent lights usually cause hot spots, and can require large amounts of electric power, usually in the form of alternating current. Therefore, they are not always practicable for use in smaller-sized or battery-powered and portable display devices. Electroluminescent lamps provide illumination proportionate to the amount of electric power provided, so although they may work in battery powered and portable devices, the illumination they provide is limited to the amount of electric power available, which may sometimes not be adequate in a battery operated or portable display device.
Accordingly, there is a need for a display device with a rear-illumination means for its display area that overcomes such problems. The present invention is directed to overcoming one or more of these problems.
SUMMARY OF THE INVENTION
In one aspect of the present invention, a display device comprises a display area that is at least partially translucent. An illumination source is disposed behind the display area, and a diffuser baffle is disposed between the illumination source and the display area. The diffuser baffle includes at least one diffuser lens and at least one spacer disposed adjacent to the diffuser lens. The spacer forms a gap between the diffuser lens and one of the display area and the illumination source.
These and other objects and advantages of the present invention will be classified in the following description of the preferred embodiment in connection with the drawings, the disclosure and the appended claims, wherein like reference numerals represent like elements throughout. The drawings constitute a part of this application and include exemplary embodiments of the present invention and illustrate various features thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is front view of a display device according to one embodiment of the present invention;
FIG. 2 is a schematic illustration of an illumination source for the display device of FIG. 1 ;
FIG. 3 is an exploded view of one embodiment of a diffuser baffle and its components implemented in the display device of claim 1 ; and
FIG. 4 is a schematic illustration of an alternate embodiment of an illumination source for the display device of FIG. 1 .
Corresponding reference characters indicate corresponding parts throughout the several figures for more convenient understanding and practice of the present invention.
DETAILED DESCRIPTION
While the present invention may be embodied in many different forms, there is shown in the drawings and discussed herein a few specific embodiments with the understanding that the present disclosure is to be considered only as an exemplification of the principles of the invention and is not intended to limit the invention to the embodiments illustrated.
Referring to FIG. 1 , a front view of a display device 10 according to one embodiment of the present invention is shown. Display device 10 includes a display area 12 , such as a panel, which may have something of interest displayed thereon. Although display area 12 depicted in the drawings is flat and rectangular, it is recognized and anticipated that the present invention is applicable to display devices with display areas of any shape or size. Display area 12 is preferably at least partially translucent whereby at least some light may pass therethrough. Various materials are known in the art, such as partially transparent plastic or painted glass, that are at least partially translucent and are used for forming display areas in display devices.
Display device 10 is electrically coupled to an electric power source 14 by one or more electrical conductors 16 . Electric power source 14 may be an external source of AC or DC electric power, or it may be an internal source of electric power such as a battery held inside or adjacent to display device 10 . Electrical conductors 16 may be any component capable of conducting electric current, such as wires, leads, conductive traces on a circuit board, and the like.
Referring to FIG. 2 , a schematic illustration of an illumination source 18 for display device 10 is shown. Illumination source 18 includes a board or panel 19 that can hold electrical or electronic components. In one embodiment, board or panel 19 is a 5 mil. thick flexible printed circuit board with electrical and electronic components embossed therein and interconnected in a predetermined manner with conductive epoxy. In such embodiment, the embossed electrical and electronic components may be potted with non-conductive UV or thermally cured resin epoxy, which is known in the art. Illumination source 18 is disposed behind display area 12 and is operable to emit light at display area 12 from behind as shown in FIG. 3 and discussed in more detail below.
Illumination source 18 includes one or more light devices 20 that are operable to emit light. In one embodiment, light devices 20 are surface-mount device (SMD) light emitting diodes (LED). In other embodiments, light devices 20 may be light bulbs, fiberoptic channels, fluorescent tubes, electroluminescent lamps, or any other means or device capable of emitting light. The number of light devices 20 in illumination source 18 will typically vary from one embodiment to another, and will usually depend on the light requirements for display area 12 in the particular embodiment of display device 10 , the light output of the particular light devices 20 implemented in that embodiment, and the electrical power available from electric power source 14 in that embodiment. In this regard, it is recognized and anticipated that the types and number of light devices 20 implemented in a particular embodiment of the present invention may be customized in accordance with the particular requirements of an embodiment. In the embodiment shown in FIG. 2 , illumination source 18 includes sixteen light devices 20 , each of which are commercially available SMD LEDs rated 20 mA at 3.5V.
Light devices 20 may be positioned on illumination source 18 in any configuration desired for a particular embodiment of the present invention. The layout may depend on the light output of each respective light device 20 and the amount of illumination desired for the various portions of the corresponding display area 12 . In the embodiment shown in FIG. 2 , the sixteen light devices 20 are distributed on illumination source 18 as shown to achieve a more even distribution of illumination on display area 12 .
Light devices 20 are electrically coupled to electric power source 14 via electrical conductors 16 . In one embodiment, each light device 20 is connected in parallel to electric source 14 via electrical conductors 16 so that operation of a light device 20 is not impacted by the operation of other light devices 20 on that same circuit. However, it is recognized and anticipated that in alternate embodiments light devices 20 may be connected in series, or in a combination of parallel and series, without departing from the spirit and scope of the present invention.
Disposed between display area 12 and illumination source 18 is a diffuser baffle 22 . Referring to FIG. 3 , an exploded view of one embodiment of diffuser baffle 22 is shown implemented between display area 12 and illumination source 18 . A diffuser baffle 22 according to the present invention includes at least one diffuser lens 24 with a spacer 26 on at least one side. Diffuser lenses 24 are essentially a sheet or panel of a translucent material that is preferably substantially translucent but not completely transparent, such as semi-clear plastic, vellum, polyester, paper, elastomer, or the like. The thickness of each diffuser lens 24 may vary, and is 5 mils in one embodiment. Spacers 26 serve the purpose of separating the items disposed on each side thereof and to form a gap 28 between those items. In this regard, spacers 26 may be made of any material such as polycarbonate, polyester, plastic, wood, and the like. In one embodiment, spacers 26 include a pressure-sensitive adhesive for implementation in diffuser baffle 22 by adhering the pressure-sensitive adhesive with an adjoining item. The thickness of spacers 26 may be adjusted in each embodiment to correspond to the thickness of gap 28 desired between the items on each side of the respective spacer 26 in that particular embodiment. In one embodiment, the thickness of spacers 26 is 9 mils. each.
In the embodiment shown in FIG. 3 , diffuser baffle 22 includes three diffuser lenses 24 separated by spacers 26 with gaps 28 formed by spacers 28 . In one embodiment, gaps 28 consist of ambient air disposed between the items on each side of the respective spacer 26 . In alternate embodiments, gaps 28 may consist of an inert gas, such as Nitrogen, held in the gap by an airtight laminating material that laminates the spacer and at least one of its adjoining items. Many types of airtight transparent laminating materials are known in the art.
In this configuration, display area 12 on display device 10 is illuminated from behind when electric power source 14 provides electric power to light devices 20 . Light emitted by light devices 20 passes through each of the gaps 28 and diffuser lenses 24 between illumination source 18 and display area 12 . During such travel, the light is dispersed by each diffuser lens 24 . The dispersed light from a diffuser lens 24 is scattered over a wider area because of the gap 28 following that diffuser lens 24 . This dispersed and scattered light is further dispersed and scattered by each successive diffuser lens 24 and gap 28 . As a result, when the light reaches display area 12 , it is considerably dispersed and scattered from its origin which was at one or more specific source points. This dispersed and scattered light travels through the at least partially translucent display area 12 and gives the aesthetic impression of an illuminated display area 12 with comparatively more even illumination and considerably reduced or no hot spots.
In this regard, those skilled in the art will appreciate that increasing the number of diffuser lenses 24 and gaps 28 in an embodiment of the present invention will directly correlate to more even scattering and dispersion of light emitted by light devices 20 on display area 12 and, therefore, minimizing the appearance of hot spots.
In the embodiment shown in FIG. 3 , display device 10 also includes a holding means 30 and 32 for holding illumination source 18 more securely in display device 10 . Holding means 30 and 32 may be constructed of any material known in the art, and it is recognized that they are optional and not critical for practicing the present invention.
In alternate embodiments of the present invention, diffuser lenses 24 and the placement of light devices 20 may be altered to control the illumination of display area 12 . For example, if a certain portion of display area 12 needs to be highlighted more than other areas, such as to highlight a logo or trademark, a light device 20 may be placed directly behind such area and the portions of the diffuser lenses 24 directly between that light device 20 and the portion to be highlighted may be made thinner, or more transparent, or removed altogether, to increase the amount of light delivered to that portion of the display area 12 . Referring to FIG. 4 , a schematic illustration of an alternate embodiment of an illumination source 118 for a display device 10 is shown wherein four light devices 120 are strategically placed in a certain concentrated circular pattern to deliver comparatively more light to the middle portion of the left half of the corresponding display area 12 . In alternate embodiments, the strength and types of light devices 20 and their respective placement or pattern on illumination source 18 behind display area 12 may be customized to suit the particular requirements of the respective embodiment. Such patterns may include, for example, light devices 18 implemented in a square pattern, a triangular pattern, an uneven zigzag pattern, or the like. Accordingly, all such modifications and alterations are recognized and anticipated, and it is intended that the claims shall cover all such embodiments that do not depart from the spirit and scope of the present invention.
It is further recognized and anticipated that electronic controls and other features may be implemented in the electric circuitry associated with illumination source 18 of display device 10 . For example, a switch (not shown in the drawings) may be added to the electric circuit formed by electric power source 14 , electrical conductors 16 , and light devices 20 to selectively switch light devices 20 , and consequently the illumination on display area 12 , on and off. The switch may be any type of electric switch, and is a membrane switch in one embodiment. Membrane switches are known in the art.
In one embodiment, electronic control means may be added to the circuit formed by electric power source 14 , electrical conductors 16 , and light devices 20 to control the operation of light devices 20 in a predetermined manner. For example, various light devices 20 may be programmed to turn on and off or blink in a predetermined manner or pattern to enhance the aesthetic appeal of the contents displayed on display area 12 or to make them more attention-catching for observers. Or, light devices 20 of different colors may be implemented in certain patterns and their operation may be controlled to enhance the message or appeal of the contents of display area 12 . Various electronic control means to perform such operations with light devices, particularly with LEDs, are well known in the art and many are commonly available commercially.
As is evident from the foregoing description, certain aspects of the present invention are not limited by the particular details of the embodiments illustrated herein, and it is therefore contemplated that other modifications and applications, or equivalents thereof, will occur to those skilled in the art. It is accordingly intended that the claims shall cover all such modifications and applications that do not depart from the spirit and scope of the present invention.
Other aspects, objects and advantages of the present invention can be obtained from studying the drawings, the disclosure, and the appended claims. | A display device including an illumination source disposed behind an at least partially translucent display area, with a diffuser baffle disposed therebetween. The diffuser baffle includes at least one diffuser lens with a gap on at least one side thereof. Light emitted by one or more light devices on the illumination source is dispersed and scattered by the diffuser lens and gap in the diffuser baffle before being projected on the back of the at least partially translucent display area. The dispersed and scattered light from behind more evenly illuminates the at least partially translucent display area. | 6 |
BACKGROUND OF THE INVENTION
The present invention relates to the improvement of a veneer lathe to cut off veneer sheets from a log.
In a conventional veneer lathe, a driving force is transmitted to the butt ends of a log through the chucks of a spindle which grips the butt ends of the log directly. In such a veneer lathe, since the diameter of the chuck is smaller than the diameter of the log, the gripped butt ends of the log can not withstand the cutting resistance applied to the log by the cutting knife, so that the gripped butt ends are twisted off or fractured frequently. Thus such a conventional veneer lathe has a disadvantage that most logs cannot be cut down to an intended diameter (usually 100 mm for a log of 1 m in length).
The applicant of the present invention developed and proposed a new veneer lathe such as disclosed in Japanese Patent Publication No. 56-16729 in order to overcome the disadvantage of the conventional veneer lathes. The new veneer lathe proposed by the applicant of the present invention, comprises a rotary roller having a plurality of annular driving members each having a plurality of spikes arranged along the circumference thereof, said driving members being attached to the roller at suitable intervals along the axial direction of the rotary roller, said rotary roller being disposed substantially in parallel to an edge of the cutting tool and so as to enable the spikes to thrust into the circumference of a log at a position near the edge of the cutting knife, a driving unit for driving the rotary roller and a pressure member, such as a fixed bar or a roller, disposed on at least one side of each driving member, to wit, in some of a plurality of spaces formed between the driving members of the rotary roller.
Since driving force is applied to a log at the circumference thereof near the edge of the cutting knife through the driving members of the rotary roller in cutting the log on the above-mentioned new veneer lathe, damage to the log resulting from the concentration of stress on the gripped part of the log, which is likely to occur in cutting a log on a conventional veneer lathe, occurs scarcely. Additionally, a trouble that a space between the pressure members and a log is clogged with foreign matters such as the bark of logs and pieces of wood and damage to logs resulting from such a trouble are avoided and almost all logs can be cut down to a conventionally intended diameter to produce superior veneer sheets, so that many logs are cut into veneer sheets remarkably effectively as compared with log cutting on conventional veneer lathes.
The outside diameter of a stripped core of about 100 mm for a log of 1 m in length was a desirable outside diameter at the times when logs of comparatively large diameters were available comparatively easily. However, such an outside diameter is not necessarily said to be sufficiently reduced in recent years, when logs of large diameters are not easily available, much less in the future when the diameter of available logs will be reduced still further and hence a further reduction of the outside diameter of the stripped core will be necessary.
As well known, the rigidity of wood in general is considerably low as compared with those of metals and the deflection of a cylindrical body varies in proportion to a function of the fourth power of the diameter and the third power of the length. Therefore, when the outside diameter of the stripped core is reduced below 100 mm, the rigidity is reduced sharply with the result that the log is broken or that a veneer sheet of uneven thickness unsuitable for use is produced due to considerably increased deflection of the log. Furthermore, the spikes of the driving member are required to be thrusted deeper into the circumference of a log to prevent the sharp reduction of the engagement between the circumference of the log and the driving members of the rotary roller as the diameter of logs becomes smaller. The presence of cracks caused by stress and radiating from the core (the heart of the log) also promote damage to logs. Accordingly, even the above-mentioned new veneer lathe is incapable of cutting a log easily to a smaller diameter merely by reducing the outside diameter of the spindles and thereby is incapable of coping with expected difficult availability of suitable logs.
SUMMARY OF THE INVENTION
The present invention improves the above-mentioned new veneer lathe further to enable the veneer lathe to cut a log down to a still smaller diameter and provides a veneer lathe capable of effectively cutting logs under the present condition of log supply and of capable of coping with the future log supply condition, in which only logs of reduced diameters will be available.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partial elevation of one embodiment of the present invention;
FIG. 2 is a side elevation of the veneer lathe of FIG. 1;
FIGS. 3 to 10 are schematic illustrations of a log and spindles for explaining various manners of engagement between the center bores formed in a log and spindles;
FIG. 11 is a perspective view of a roller bar provided on the veneer lathe;
FIG. 12 is a partial elevation of a fixed bar provided on the veneer lathe;
FIG. 13 is a partial elevation of a preferred example of the rotary roller;
FIGS. 14 to 17 are partial perspective views of various forms of spindles according to the present invention;
FIG. 18 is a partial elevation of another embodiment of the present invention;
FIG. 19 is a side elevation of the veneer lathe of FIG. 18;
FIG. 20 is a partial plan view of a boring mechanism used in the embodiment of FIGS. 18 and 19;
FIG. 21 is a side elevation of the boring mechanism of FIG. 20;
FIG. 22 is a partial elevation of a further embodiment of the present invention; and
FIG. 23 is a side elevation of FIG. 22.
DETAILED DESCRIPTION OF THE EMBODIMENTS
A veneer lathe according to the first embodiment of the present invention is provided for cutting logs each having a center bore or bores formed beforehand in the log along the center axis thereof at an appropriate place and is constituted so as to support a log with spindles inserted in the center bore, while a veneer lathe according to the second embodiment of the present invention is designed so as to drill a center bore or bores along the center axis of a log and at the same time to support the log with spindles inserted into the center bore or center bores. Thus, each veneer lathe of the present invention securely supports a log through the engagement of spindles with the center bore or the center bores formed in a log. The detailed forms of spindles will be described more concretely hereinafter.
Various forms of engagement between the spindles and the center bore or the center bores of a log are possible, which are, for example, inserting spindles 2a each having a diameter that fits the corresponding center bore 13 drilled through a log along the center axis thereof into the center bore 13 as shown in FIGS. 3 and 9, inserting spindles 2a each having a diameter that fits the corresponding bottomed center bore 13 formed in a log along the center axis thereof into the center bores 13 as shown in FIG. 4, inserting spindles 2b each having a length reaching the bottom surface of the corresponding bottomed center bore 13 formed in a log along the center axis thereof into the bottomed center bores 13 as shown in FIG. 5 and inserting spindles 2 each having a diameter that fits the corresponding bottomed center bore formed in a log 1 along the center axis thereof and a length reaching the bottom surface of the same bottomed center bore into the bottomed center bores as shown in FIGS. 6 and 8. In either case, the appropriate and sure support of a log is attained by the use of spindles each formed in a diameter and/or length that fits the center bore formed in the log, which supporting manners constitute the principle of the present invention.
FIG. 1 is a partial elevation of one embodiment of the present invention. FIG. 2 is a side elevation, of the veneer lathe of FIG. 1, showing actual log cutting operation by way of example. In FIGS. 1 and 2, a cutting tool indicated at 3 is fastened with a tool holder 12 to a tool support 11 which is adapted to move toward the center axis of a log 1 supported by spindles 2 (2a, 2b) inserted into the center bore of the log 1 as the log 1 is turned, for cutting off a veneer sheet 9 from the log 1 and away therefrom. Divided fixed bars 4 are fastened to a pressure bar holder 10 which moves together with the knife support 11. Said divided fixed bars 4 are disposed between spaces 8 formed between annular driving members 7 of a rotary roller 5 which will be described hereinafter and so as to press the boundary between the log 1 and the veneer sheet 9. The rotary roller 5 is formed by attaching a plurality of annular driving members 7 thereto each having a plurality of spikes 7a arranged along the circumference thereof on a shaft 6 at suitable axial intervals to form the spaces 8 for receiving pressure members such as the fixed bars 4 therein. The rotary roller 5 is supported in bearings 17 fixedly mounted on the pressure bar holder 10 practically in parallel to the edge of the cutting knife 3 and so as to enable the spikes 7a to thrust into the circumference of a log at a position near the edge of the cutting tool 3 during the cutting operation and is driven by a driving source such as a motor, not shown, through a sprocket wheel 18 or the like in order to drive the log along the circumference thereof near the edge of the cutting knife 3.
The veneer lathe according to the first embodiment of the present invention is constituted as described hereinbefore. In operation, when a log having center bores formed therein beforehand along the center axis thereof is fed to the veneer lathe, spindles are inserted into the center bores to support the log, and then the log is cut successively into veneer sheets of a desired thickness through the movement of the cutting tool toward the log and the driving of the log with the rotary roller. Since the line of action of the resistance of the cutting knife and the pressure members is close to the line of action of the counteracting driving force, those opposite forces are well counterbalanced. Therefore, the damage of the log attributable to the concentration of stress is prevented. In addition, since part of or all of the stress-induced cracks which have been present in the heart of the log are removed as a result of drilling the center bores, the damage of the log attributable to those cracks is prevented or is remarkably reduced. Furthermore, since the log is supported with spindles inserted into the center bores formed in the log, the deflection of the log is reduced as compared with the deflection of logs on conventional veneer lathes. Consequently, the breakage of the log or the irregularity in thickness between veneer sheets is avoided and the spikes can thrust into the circumference of the log due to the increased rigidity of the log to drive the log surely. Accordingly, the log can be cut to a small diameter to such an extent that has been impossible on conventional veneer lathes and veneer sheets of good quality can be produced.
Incidentally, in an experimental cutting operation, a larch log of approximately 1 m in length having center bores of 5 cm in diameter and 20 cm in depth formed in the opposite butt ends was subjected to cutting on a veneer lathe provided with spindles of 5 cm in diameter on the opposite ends thereof by supporting the log as shown in FIG. 6. The log could be cut to approximately 6 cm in diameter and good veneer sheets of a desired thickness were obtained.
When a log fed to the veneer lathe of the present invention is barked and dressed practically in a regular cylindrical shape, the log may be driven at the start of cutting only by the rotary roller with the result that the driving mechanism for driving the spindles can be omitted. Usually, however, logs have irregular external shapes and hence it is extremely difficult to drive a log only by the rotary roller in cutting the log. Therefore, it is desirable to provide a driving mechanism, such as a motor, for idling the log in preparation for the advancing tool. Naturally, the log may be driven directly by means of the spindles. However, since the principal driving means is the rotary roller anyhow, it is desirable to harmonize the rotary roller and the spindles by turning the rotary roller at a speed higher than that of the spindles or if necessary, by interposing a buffing mechanism, such as a one-way clutch, between the rotary roller and the driving unit or by interposing a buffing mechanism, such as a torque limiter, between the spindles and the driving unit.
It is effective to attain stable support of a log to insert both right-hand and left-hand spindles into the corresponding center bores, for example, as shown in FIGS. 3 to 9. However, the forms of the right-hand and left-hand spindles are not necessarily the same with each other as shown in FIG. 7. Although not necessarily desirable, either the right-hand or the left-hand spindle may be a conventional spindle 15 which is not inserted into the center bore as shown in FIG. 10. Furthermore, if necessary, a known double spindle mechanism as shown in FIG. 8 may be employed, in which a larger spindle 14 is provided over the spindle 2 (2a, 2b) to support a log and the log may be driven also by means of the larger spindle until a suitable timing.
The form of the spindle inserted into the center bore formed in a log is basically a cylindrical shape as shown in FIG. 14. However, the form is not limited to a regular cylinder of a uniform diameter but may be a cylinder having a plurality of sharp projections 19 of a suitable shape at the extremity thereof as shown in FIG. 15, a cylinder having a plurality of projections 21 of a suitable shape along the circumference thereof as shown in FIG. 16 or a cylinder having a plurality of sharp projections 19 of a suitable shape at the extremity thereof and a plurality of projections 21 of a suitable shape along the circumference thereof as shown in FIG. 17. Such spindles of modified forms prevent effectively the slip between the spindle and the log and ensure further the engagement between the spindle and the log, so that the spindles are capable of effectively driving the log as occasion demands.
Naturally, the right-hand spindle and the left-hand spindle may be joined within the center bore, as shown in FIG. 9, if necessary. The detachable front end portion extending from the front end to a suitable position indicated at 20 in FIG. 15, will facilitate the replacement of the projections when worn out and will allow the diameter of the spindle to be changed. Similarly, detachable projections will facilitate the replacement of the projections when worn out. Provision of a guide member 22 having a suitably chamfered head will facilitate the insertion of the spindle into the center bore. Provision of a cutting edge 23 for the edge of the projections 21 will prevent the damage of the log resulting from pressure-fitting the projections into the log and will allow smooth insertion of the spindle into the center bore. In either case, the respective forms of those projections are not limited to those as shown in the drawings. The diameter of the spindles includes an error permitting the elastic and plastic deformations of the fibers of wood including the error and the strains in the center bores. When projections are provided along the circumference of the spindle, a further increased range of tolerance on the error is allowed owing to the pressing action of the projections.
The pressure members are not limited to those fixed bars as shown in FIGS. 1 and 2, but may be roller bars each formed of a divided holder 4a and a roller 16 supported rotatably by the divided holder 4a, as shown in FIG. 11, or may be an undivided fixed bar 4b formed in the shape of a comb as shown in FIG. 12. In either case, smooth removal of foreign matters, such as bark of logs and wood pieces, and absorption of the local hardness variation in logs are possible when the pressure members are fastened to the pressure bar holder in the manner of cantilever as illustrated so as to allow the elastic deformation of the pressure members, consequently, satisfactory cutting operation can be attained effectively.
The form of the driving member of the rotary roller is not limited to the form of a circular saw as illustrated and the form of the spike, in particular may be a wedge-shape as illustrated or various other shapes such as a needle-shape, a conical shape and a pyramidal shape. In either case, a shape that allows the spike to thrust into a log easily is suitable for effectively driving a log. Instead of forming the driving members integrally with the shaft as shown in FIG. 13, the driving members may be mounted detachably on the shaft, which facilitates forming the rotary roller and replacing the driving members in case of wear and reduces the manufacturing cost and the cost of wear and tear.
The rotary roller may be disposed so as to allow the spikes to thrust only into the circumference of a log at a position near the edge of the cutting knife or so as to allow the spikes to thrust into the circumference of a log at a position near the edge of the cutting knife and also to thrust into the veneer sheet at a position immediately after the edge of the cutting knife. Furthermore, a stripping member, not shown, of a suitable shape for surely separating the veneer sheet and foreign matters from the spikes may be provided, if necessary, in a space after the driving members.
The center bores drilled in a log will be described hereinafter. The position of the center bores in a log may be determined by a suitable method selected from various methods, such as a method of aligning the center axis of the bore with the center axis of the imaginary inscribed cylinder of a log for attaining the best yield of a continuous veneer sheet as the principal object, a method of aligning the center axis of the bore with the center axis of the imaginary circumscribed cylinder of a log for attaining the best yield rate as the principal object, a method of aligning the center axis of the bore with the center axis of the heart of a log for allowing the general classification of veneer sheets by water content as the principal object, and a method of determining the position of the bore specially to clear off the deteriorated portion, such as the rotten portion, of a log. The depth of the center bore may be comparatively small when the length of the spindle is as long as to reach the bottom of the center bore, whereas a comparatively large depth is effective when a spindle having a diameter capable of engaging with the inside surface of the bore is inserted into the center bore. Naturally, the bores may be a single through bore penetrating through a log or the form may be different between the right-hand center bore and the left-hand center bore. In either case, it is desirable that the depth of the center bores is equivalent to or greater than the diameter of the spindle. Chamfering the edge of the center bores will facilitate insertion of the spindle into the bores.
Storage of logs to be cut after drilling such center bores in the logs will effectively prevent or reduce the occurence or development of cracks caused by stress or contraction resulting from drying. On the other hand, however, such a method of storage has disadvantages that the center bores and the spindles have to be center-aligned again in feeding the drilled log to the veneer lathe, which is inefficient if the bores and the spindles are center-aligned mechanically or manually and that drilling the logs manually by means of a boring machine equipped with a drilling tool such as a wood drill is not only inefficient but also causes troubles such as misalignment or misdrilling, so that regular cutting is impossible due to inappropriate insertion of the spindles in the center bores. Thus such a method of storage of logs is not preferable.
A veneer lathe according to the second embodiment of the present invention comprises, in addition to the veneer lathe of the first embodiment, a boring mechanism for drilling center bores in a log along the center axis thereof and a log feeding mechanism for feeding a log having center bores to the main part of the veneer lathe, and is capable of extremely efficiently cutting a log. A veneer lathe according to the second embodiment will be described hereinafter.
FIG. 18 is a partial elevation of the second embodiment. FIG. 19 is a side elevation of the veneer lathe of FIG. 18. A boring mechanism is indicated generally at A. As shown in FIGS. 20 and 21 by way of example, the boring mechanism A is provided retractably with a wood drill 24 held by a drill chuck 29 attached to the front end of a splined shaft 28 rotatably supported by a slide base 30 driven to reciprocate along slide guides 27 supported by metals 25 and 26 by means of a suitable driving device, not shown, through levers 31 and 32 and adapted to be driven for rotation by a suitable driving device, not shown, through a pulley 33 and a belt 34, is provided, on each of the right-hand side and the left-hand side thereof, with a centering device C including lifting devices 35 and 37 each having a hydraulic cylinder, a log support 36 adapted to be raised and lowered by the lifting device 35 and a log holder 38 adapted to be raised and lowered corresponding to the upward and downward movement of the log support 36. The boring mechanism A drills a center bore along the center axis of a log 1 supported and centered by the centering devices C, which is constituted so as to determine the center axis on the basis of the external form of the log 1. A log feeding device B comprises a swing base 40 adapted to be driven by a driving device, not shown, including a crank mechanism and hydraulic cylinders so as to swing on a shaft 39 and a pair of spiked bases 26 disposed on the right-hand side and the left-hand side, respectively, of the log feeding device, provided with a plurality of spikes 43 on the surfaces thereof for receiving a log and adapted to be raised and lowered and also to be fixed at an appropriate position by means of an operating device 41 having a locking mechanism including hydraulic cylinders having intermediate position locking mechanisms and connected to the right-hand side and the left-hand side of the swing base 40. The log feeding device B transports a log 1 which has been drilled by the boring mechanism A to form center bores along the center axis thereof to the main part of the veneer lathe by holding the log 1 with the spiked bases with the spikes thrusting into the log 1. The constitution of the main part of the veneer lathe of the second embodiment is identical with the veneer lathe of the first embodiment.
The exemplary veneer lathe of the second embodiment as described hereinbefore operates in the following manner. When supplied to the veneer lathe, the log 1 is centered by the centering devices C, then center bores are formed along the center axis of the log 1 by means of the boring mechanism A, then the log 1 is transported to the main part of the veneer lathe by means of the log feeding device B and is supported by the spindles 2 (2a, 2b), and then the log is cut gradually.
As apparent from what has been described hereinbefore, the veneer lathe of the second embodiment comprises, in addition to the veneer lathe of the first embodiment, a boring mechanism for drilling center bores in a log along the center axis thereof and a log feeding device for transporting the log having center bores drilled therein to the main part of the veneer lathe. Accordingly, the veneer lathe of the second embodiment is not only capable of cutting a log to a reduced diameter as compared with diameters attainable by conventional veneer lathes, but also is capable of effectively eliminating troubles such as misalignment or misdrilling, which troubles are liable to occur when the center bores are drilled in a log manually by means of a drilling apparatus, of preventing various disadvantages such as the damage of the log and the irregular diameter of the veneer sheet which are caused by the deflection of the spindles or bending of the spindles which is attributable to above-mentioned troubles, of effectively performing appropriate cutting of the log and of remarkably efficiently carrying out the cutting operation as compared with cutting a log by taking out each time a log which has been stored after forming center bores along the center axis thereof and by supporting the log after centering the log again.
The boring mechanism is shown in the drawings only by way of example and hence is not limited thereto. The boring mechanism may be a boring apparatus equipped with a built-in driving source, such as an electric drill or a pneumatic drill, disposed retractably and provided with a drilling tool such as a woodworking drill. Essentially, the boring mechanism may be of any form provided that it is provided retractably with a drilling tool such as a wood drill and is capable of drilling a center bore along the center axis of a log supported by the centering device or the log feeding mechanism. The provision of the boring mechanisms on both ends of the veneer lathe or the provision of the boring mechanism either on the right-hand side or the left-hand side of the veneer lathe may be suitably and selectively corresponding to the form of the spindle or spindles of the main part of the veneer lathe. Furthermore, when the spindle or the spindles of the main part of the veneer lathe is divided at an appropriate part thereof so as to make the front part replaceable and various front parts are used alternately, it is required only to make the distance of the axial movement and the thickness of the drilling tool changeable.
A woodworking drill is preferable for the drilling tool, since a woodworking drill has a high capability of removing chips, however, a metalworking drill may be used. Essentially, any drilling tool may be used provided that the drilling tool is capable of drilling a center bore of a desired form. Naturally, the point of a drilling tool need not necessarily be perpendicular to the center axis.
The log feeding mechanism is shown in FIGS. 19 and 20 by way of example and hence is not limited thereto. For example, the log feeding mechanism may be a log centering and feeding mechanism D as shown in FIGS. 22 and 23, comprising two sets of paired upper and lower slide arms 46 movably supported by rollers 45 rotatably supported by a frame 44 and adapted to be reciprocated between the boring mechanism A and the main part of the veneer lathe by a driving device, not shown, having a hydraulic cylinder, and paired upper and lower holding bases 48 adapted to be raised and lowered in harmony with each other by a lifting device 47 having hydraulic cylinders 47 attached to the respective front end of the slide arms 46. Each set of the upper and lower slide arms 46 and the upper and lower holding bases 48 is disposed on each side of the log centering and feeding mechanism D. The log centering and feeding mechanism D determines the center axis of a log on the basis of the external form thereof. The log feeding mechanism may be a mechanism including a pair of right and left spiked arms which thrust into the opposite butt ends of a log to hold the log and are adapted to reciprocate between the boring mechanism A and the main part of the veneer lathe. A log feeding mechanism of any form may be employed provided that the log feeding mechanism comprises spiked bases, holding bases or spiked arms adapted to hold a log having center bores and to be capable of reciprocating at least between the boring mechanism and the main part of the veneer lathe.
Furthermore, centering a log and drilling the center bores in the log need not necessarily be performed at the same position but may be performed at different positions. In case where centering a log and drilling the center bores in the log are performed at different positions, it is preferable to constitute the log feeding mechanism so as to make the log holding members travel from the centering position to the main part of the veneer lathe in three steps to avoid the additional provision of a means to transport a log from the centering position to the boring mechanism. Any known conventional centering device is applicable instead of the centering device as illustrated. In some cases, for example, in determining the center axis along the center axis of the heart of a log or in determining the center axis in a particular manner, it is more convenient to determine the center axis while holding a log by hand, therefore, a centering device need not necessarily be provided. Provision of a stripped core removing stopper of a suitable form, which allows the advancement and the retraction of the spindle and obstructs the advancement and the retraction of the stripped core of a log, near the either butt end of a log allows quick removal of the stripped core of a log after cutting merely through the retraction of the spindle. Such an arrangement further improves the cutting efficiency of the veneer lathe.
It will be apparent from what has been described hereinbefore that the veneer lathe according to the present invention is capable of cutting a log to a smaller diameter as compared with the conventional veneer lathe, extremely efficiently and is remarkably effectively applicable to plywood factories in view of the present state and the future prospects of the plywood industry that plywood factories are obliged to use the thin logs of South-Sea wood or to alternatively use small diameter logs due to the depletion of resources. | A veneer lathe for turning a log thereon to cut off veneer sheets therefrom. The log is principally driven by a rotary roller having a plurality of projections therearound, which roller is pressed against the log to ensure positive engagement with the periphery thereof. The log is formed with a center bore at a core portion thereof. A spindle to support the log is inserted into the center bore to prevent the log deflection due to the pressure from the rotary roller. Another form of this veneer lathe is additionally provided with a center bore forming mechanism together with a centering mechanism for the boring operation such that a center bore is formed in the log in advance before being turned on the veneer lathe. | 1 |
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