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The invention relates to copolymers which contain siloxane units which are crosslinkable as a result of the action of a photosensitive cationic catalyst such as salts of sulfonium or iodonium. These siloxane units contain a lateral peripheral vinyl ether group connected by a bridge group to a silicon atom, this bridge group having the structure of an aliphatic or aromatic urethane. The substituent groups on the siloxane, which carries peripheral vinyl ether, have the structure of trimethylene urethane-2-ethyl vinyl ether, trimethylene-m-toluenediurethane vinyl ether or 3-thia-1,5-pentanediyl-m-toluenediurethane vinyl ether, as nonlimiting examples.
The vinyl ether group unit alternates along the polysiloxane chain with dimethylsiloxane or methylphenylsiloxane or alkylfluoralkylsiloxane units, or tetraalkyl-alpha,omega-fluoroalkylenedisilaoxane units, or polymer sequences thereof. Said fluoroalkyl or alpha,omega-fluoralkylene group can be obtained by telomerization of tetrafluoroethylene. The proposed silocones can be, for example, crosslinked in the presence or absence of air by conventional irradiation using a mercury vapor lamp or in the presence of salts of sulfonium or iodonium, such as hexafluoroantimonate of triphenylsulfonium. The films of crosslinked polymers are characterized by hydrophobic-oleophobic properties and by antiadhesive properties as well as by good heat resistance and they are useful as protecting insulation layers or as antiadhesive products for paper.
These properties are particularly pronounced when the structure contains fluoroalkyl or fluoroalkylene groups. The antiadhesive property with respect to strong adhesive ribbons is particularly effective at high temperature.
The copolymers of the invention have a molecular weight from 5,000 to 100,000, preferably from 5,000 to 50,000, and they have formula I:
(R.sub.a).sub.3 SiO(V).sub.v --(W).sub.w --(Y).sub.y --(Z).sub.z --Si(R.sub.a).sub.3 I
where
V=--SiR a R b O--;
W=--SiR' a (R c --R d --OCH═CH 2 )O--;
Y=SiR a R g O--;
Z=--R a R g SiC n H 2n R' f C n H 2n SiR a R g O-- with n=2, 3 or 4;
v, y, z are identical or different numbers, which can however not be zero simultaneously; w is always different from zero; and the ratio of v+y+z/w is between 1 and 100; the R a groups represent, independently of each other, a radical selected from the group consisting of CH 3 , C 2 H 5 , n--C 3 H 7 , n--C 4 H 10 radicals, and phenyl, with not more than one phenyl radical being attached to a given silicon atom;
R b =R a ;
R' a =R a , --OCH 3 or OC 2 H 5
R c =--C 2 H 4 --, --C 3 H 6 --, --C 2 H 4 --S--C 2 H 4 --, or --C 3 H 6 --S--C 2 H 4 --;
R d =--OCONHR e NHCO--, --NH--COOC 2 H 4 --, or --NHCOOC 3 H 6 --;
R 3 =--C 6 H 3 (CH 3 )--, --C 6 H 4 CH 2 C 6 H 4 --, --(CH 2 ) 6 --, --C 6 H 10 --CH 2 --C 6 H 10 --, or --CH 2 --[(CH 3 ) 3 C 6 H 7 ]--;
R g =--C k H 2k --R f where k=2, 3 or 4;
R f is a perfluoroalkyl group with 1 to 12 carbon atoms such as --CF 3 , --C 2 F 5 , --C 3 F 7 , --C 4 F 9 , --C 6 F 13 , or --C 8 F 17 , where the higher perfluoralkyl groups can be formed by telomerization of tetrafluoroethylene (TFE), or a monovalent radical of an aligomer of fluorated oxetanes or oxiranes; R' f is a perfluoroalkylene group containing from 4 to 10 carbon atoms such as --C 4 F 8 --, --C 6 F 12 -- or C 8 F 16 --, or an alpha,omega-fluoralkenyl group formed by the telomerization of tetrafluoroethylene or a divalent telochelating radical of an oligomer derived from fluorinated oxetanes or oxiranes, or a m-phenylenedi(hexafluoroisopropoxy) radical; the units V, W, Y and Z can be arranged randomly, in order, or alternated along the polymer chain.
Of the claimed structures, the siloxane units V are obtained by methods which are well known to an expert in the field of commercial silanes. The siloxane units W are obtained, as nonlimiting examples, either by condensation of 3-acetoxypropylmethyldicholorosilane with units of the disilanol type and/or hydrolysis of the acetoxy group and condensation of the hydroxyl group released with alpha,omega-monoisocyanato-m-tolylurethane-ethylene-2-vinyl ether (pathways a, b). ##STR1## where R e has the above-mentioned structure, said reaction of diisocyanates with hydroxyl groups is catalyzed by dilauryldibutyltin at a temperature of 50° to 60° C.; or by addition of 2-thioethanol to sequences of methylvinylsiloxane, catalyzed by a free radical initiator such as azobisisobutyronitrile at 70° C. (pathway c).
[SiCH.sub.3 (CH═CH.sub.2)O]+n HSC.sub.2 H.sub.4 OH→--[SiCH.sub.3 (CH.sub.2 CH.sub.2 SC.sub.2 H.sub.4 OH)O].sub.n --(cl)
The sequences (cl) are then reacted with alpha,omega-monoisocyanatourethane-ethyl vinyl ether (al)
(al)+(cl)→[OSiCH.sub.3 --(C.sub.2 H.sub.4 SC.sub.2 H.sub.4 OCONHR.sub.e NHCOOC.sub.2 H.sub.4 OCH═CH.sub.2)]
or by reacting 3-isocyanatopropyltriethoxysilane with 2-hydroxyethyl vinyl ether (pathway e).
(e) (EtO).sub.3 SiC.sub.3 H.sub.6 NCO+HOC.sub.2 H.sub.4 OCH═CH.sub.2 →(EtO).sub.3 SiC.sub.3 H.sub.6 --NHCOO--C.sub.2 H.sub.4 OCH═CH.sub.2
The fluorinated organosilicon reaction compounds having the formulas
X.sub.2 R.sup.1.sub.2 Si II or
XR.sup.2.sub.2 Si(R.sup.3 SiR.sup.2.sub.2).sub.z X III
are intermediate compounds for the siloxane units of the invention corresponding to Y and Z, where X represents a reactive group selected from the group consisting of halogens, preferably chlorine, the hydroxyl, alkoxy, acetoxy, amino, alkylamino and dialkylamino groups, z has values from 1 to 5 inclusively, at least one radical R 1 with formula II and at least one of the radicals R 2 connected to each one of the silicon atoms of formula III is selected from the group:
1) The fluoroalkyl groups with formula --C K H 2k R f where R f is a perfluoroalkyl group with from 1 to 12 carbon atoms, such as --CF 3 , --C 2 F 5 , --C 3 F 7 or --C 4 F 9 , where the higher perfluoroalkyl groups can be obtained by telomerization of tetrafluoroethylene, and k=2, 3 or 4.
2) The radicals of monovalent oligomers of fluorinated oxetanes and oxiranes, said radicals being attached to the silicon by a group which contains a nonhalogenated ethylene radical or a nonhalogenated trimethylene radical; all of the possible other radicals R 1 and R 2 are selected from the group consisting of alkyl radicals with 1 to 4 carbon atoms, alkenyl radicals, perfluoroalkyldimethylene, -trimethylene or -tetramethylene, phenyl or phenyl substituted by a perfluoralkyl group, with the perfluoralkyl fragment of said radicals being substituted by a perfluoralkyl group which contains from 1 to 4 carbon atoms; and R 3 is a divalent radical with the formula --C k H 2k --R' f --C k H 2k -- where R' f contains a radical --(C 2 F 4 )-- n -obtained by telomerization of tetrafluoroethylene, or a divalent radical derived from oligomers of fluorinated oxetanes or fluorinated oxiranes, or it is a metaphenylenedi(hexafluoroisopropoxy) radical.
The oligomer radicals represented by R 1 and R 2 have the formulas:
R.sub.f "O(C.sub.3 F.sub.6 O).sub.m CF(CF.sub.3)CA.sub.2 OC.sub.3 H.sub.6 --,
C.sub.3 F.sub.7 O(C.sub.3 H.sub.2 F.sub.4 O).sub.m --CH.sub.2 CF.sub.2 CA.sub.2 OC.sub.3 H.sub.6 --, or
R.sub.f "O(CF.sub.3 C.sub.2 H.sub.3 O).sub.m C.sub.3 H.sub.6 --.
In the preceding formulas, "A" represents hydrogen or fluorine, and R f " is --CF 3 , --C 2 F 5 or --C 3 F 7 ; all the possible radicals R 1 and R 2 which do not represent a fluoroalkyl radical or a TFE telomer or an oligomer radical as defined above each represent preferably a methyl radical, 3,3,3-trifluoropropyl, phenyl or phenyl substituted by a perfluoralkyl group, where said perfluoralkyl group contains from 1 to 3 carbon atoms.
R 3 is selected preferably from the group consisting of
--C.sub.k H.sub.2k --(C.sub.2 F.sub.4).sub.n --C.sub.k H.sub.2k--
--C.sub.3 H.sub.6 O(CF.sub.3).sub.2 C--C.sub.6 H.sub.4 --C(CF.sub.3).sub.2 OC.sub.3 H.sub.6 --,
--C.sub.3 H.sub.6 OCA.sub.2 CF.sub.2 CH.sub.2 O(C.sub.3 H.sub.2 F.sub.4 O).sub.g T'O(C.sub.3 H.sub.2 F.sub.4 O).sub.g --CH.sub.2 CF.sub.2 CA.sub.2 OC.sub.3 H.sub.6 --,
--C.sub.3 H.sub.6 OCH.sub.2 CF.sub.2 O(C.sub.2 F.sub.4 O).sub.h (CF.sub.2 O).sub.i CF.sub.2 CH.sub.2 OC.sub.3 H.sub.6 -- or
--C.sub.3 H.sub.6 OCA.sub.2 --CF(CF.sub.3)O(C.sub.3 F.sub.6 O).sub.g T'O(C.sub.3 F.sub.6 O).sub.g --CF(CF.sub.3)CA.sub.2 OC.sub.3 H.sub.6 --.
T' is selected from the group consisting of --C 2 F 4 --, --C 4 F 8 --, --C 5 F 10 -- and --(C 2 F 4 ) 2 O--;
the recurrent units are arranged randomly or in succession along the chain;
the value of k is 2, 3, 4;
the value of n is from 2 to 20 inclusively, preferably from 2 to 10;
the value of m is from 1 to 20 inclusively, preferably from 1 to 10;
the value of g is from 1 to 20 inclusively, preferably from 2 to 10; and the value of h/i is from 0.5 to 20 inclusively, and the value of h+i is from 8 to 100 inclusively, preferably from 8 to 20.
The different recurrent fluorinated organosilicon units are arranged randomly or in sequence in the molecules and the silicon atoms of these units are connected by a nonhalogenated linear alkylene radical which contains 2, 3 or 4 carbon atoms with fluoralkyl groups R f , or by a bivalent group which contains a nonhalogenated dimethylene radicals or halogenated trimethylene with the divalent group R 3 defined above. One of the radicals R 1 present in formula II and one of the terminal radicals R 2 located on each of the silicon atoms in formula III can represent alkyl, alkenyl, aryl radicals, phenyl substituted with a perfluoralkyl group and/or monovalent fluorinated alkyl groups corresponding to the formula --C k H 2k R 4 , where k is 2, 3, 4, and R 4 is a perfluoralkyl radical containing from 1 to 4 carbon atoms. R 3 can be a telomer or a divalent oligomer as defined above or it can be --[(CH 2 ) 3 OC(CF 3 ) 2]2 Ph, where Ph stands for the m-phenylene radical.
The polysiloxane chain (I) is obtained by hydrolysis or cohydrolysis or polymerization by condensation of silane intermediates of the types:
X.sub.2 SiR.sub.a R.sub.b
X.sub.2 SiR'.sub.a (R.sub.c --R.sub.d --OCH═CH.sub.2)
X.sub.2 SiR.sub.a R.sub.g
X[R.sub.a R.sub.g SiC.sub.k H.sub.2k R'.sub.f C.sub.k H.sub.2k SiR.sub.a R.sub.g ]X
X--Si(R.sub.a).sub.3
where X represents a reactive group selected from halogens, preferably chlorine, the hydroxyl, alkoxy, acetoxy, amino, alkylamino and dialkylamino groups, and K=2, 4 or 4.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
The polyorganosiloxanes prepared using the present organosilicon compounds as at least a part of the organosilicon reactants have a high thermochemical resistance and low surface energy values, which are particularly improved when their structure contains fluorinated groups.
Telomers of Tetrafluoroethylene
One class of the radicals attached to silicon according to the invention is prepared from fluorinated telomers of tetrafluoroethylene.
A preferred method for the preparation of telomers of TFE consists of a radical telomerization of TFE.
The telomerization of TFE can be initiated by telogens substituted with bromine or iodine, represented by the formula R f X or XR' f X, where R f and R' f are as defined above in the present description, and X is bromine or iodine. These telogens belong to a class which includes, without being limited to, CF 3 I, C 2 F 5 I, n- or iso-C 3 F 7 I, n-C 4 F 9 I, C 2 F 5 Br, CF 3 CFBrCF 2 Br, CF 2 Br 2 , CF 2 ICF 2 I, I(C 2 F 4 ) n I (n=2 to 10).
The telomers prepared from monobrominated or monoiodated telogens above are attached to a silicon atom by nonhalogenated alkylene radicals containing 2, 3, 4 carbon atoms, and using the methods described in the following paragraphs, to prepare the siloxanes represented by formula I.
The telogens which contain two reactive halogen atoms, iodine or bromine, produce alpha,omega-telochelating telomers which can be attached to two different silicon atoms by means of nonhalogenated linear alkylene radicals with 2, 3, 4 carbon atoms to produce fluorinated polysiloxane. To obtain the linear structure and the absence of extensive crosslinking which characterize the present organosilicon compounds, the synthesis must be organized appropriately with regard to the subsequent series of reactions of appropriate silanes with telochelating dihalotelomers and with monoiodo- and/or monobromotelomers, or with the other compounds described here.
The process of telomerization of TFE initiated by said telogens according to the present invention can be activated by heat or gamma irradiation, or ultraviolet irradiation, of initiators of the organic peroxide type or of redox systems. Preferred catalysts for these reactions are benzoyl peroxide, di-t-butyl peroxide, t-butyl peroxypivalate, and percarbonates.
The reaction can be conducted in the presence of organic solvents including, without being limited to, 1,1,2-trichlorotrifluorethane, t-butyl alcohol, acetonitrile and mixtures thereof. Catalysts such as redox systems with persulfate can also be included, and the telomerization can be carried out in an aqueous dispersion.
The telomerization temperature is between room temperature and 150° C., if the process is activated by irradiation or by catalysts, or between 150° C. and 220° C. if the process is activated thermally.
The pressure at which the reaction is conducted can range from atmospheric pressure to approximately 100 atmospheres, and one should take care to exclude oxygen from the telomerization reaction.
The fluorinated telomers are then attached to the silicon atoms of the present compounds through the intermediary of an alkylene radical without halogen consisting of 2, 3, or 4 carbon atoms, such as the dimethylene or trimethylene or tetramethylene radicals, according to a chain termination process which is carried out appropriately. Ethylene is a reactant which can be used easily in the chain termination reaction.
When they are correctly attached to the silicon as described above, the telomer chain imparts to the final fluorinated organosilicon compound high levels of chemical and thermal resistance and of antiadhesive properties.
Oligomers of Cyclic Fluorinated Ethers (Oxetanes and Oxiranes)
Intermediate oligomer fluorinated polyoxaalkylenes according to the present invention can be prepared using well known methods for the oligomerization of polyfluorooxiranes or fluorooxetanes such as perfluoropropene oxide, 2,2,3,3-tetrafluorooxetane and 3,3,3-trifluoropropene oxide. Some of these oligomers are available commercially.
According to a preferred method, the preferred oligomer polyoxaalkylenes are prepared by reacting cesium fluoride or potassium fluoride with perfluorinated carbonyl compounds such as hexafluoroacetone, trifluoroacetyl fluoride, perfluoropropionyl fluoride, carbonyl fluoride, perfluorosuccinyl or 1,5-oxaperfluoroglutaryl fluorides which can initiate the oligomerization of perfluorooxiranes and fluorooxitanes according to a known method.
The perfluorinated polyoxaalkylenecarbonyl fluoride must be reacted to form appropriate intermediate compounds which can be attached to the silicon. A preferred method consists of stoichiometric addition of potassium and subsequent substitution with allyl bromide to produce oligomer fluorinated polyoxaalkylenes terminated by allyl groups, which are then made to react with a reactive organohydrosilane.
Another pathway to attach the present oligomer fluorinated polyoxaalkylenes to the silicon atom is the metathesis of the fluoride groups of carbonyl acid terminals of these oligomers to methyl esters followed by a reduction to methanol radicals, followed by terminal capping with allyl bromide using the known Williamson synthesis.
Reaction of Fluorinated Telomers and Fluorinated Oligomers to Form Reactive Fluorinated Organosilicon Compounds
Fluorinated telomers which are terminated by one or two (XC k H 2k )--where X is bromine or iodine can be converted to an organometallic derivative such as a Grignard reagent, a copper Grignard reagent, an organic lithium, zinc, or aluminum compound, and they can then be reacted with the silane which contains at least one halogen such as fluorine, chlorine or bromine, and at least one alcoholate group. The organometallic compound can be prepared beforehand or it can be formed in the presence of the silane.
As a variant, the alpha-iodo or alpha-bromo terminal group of the telomer fluoroalkane terminated by a polymethylene group, or the analog of the telechelic alpha,omega-diiodo- or- dibromo-or -bromoiodopolymethylenepolyfluoroalkane which may be dehydrohalogenated to present, respectively, one or two terminal vinyl groups which can be reacted in a hydrosilylation reaction with silanes which contain at least one hydrogen atom connected to the silicon atom. The reaction is catalyzed by organic peroxides and platinum catalysts.
In the case of silanes with formula II, in addition to two atoms or groups required to react with the above-mentioned derivatives of fluorinated telomers and oligomers or other groups, the silanes, after the reaction with the telomers and monofunctional oligomers or with other groups, contain two reactive entities "X" as in formula II which can then be made to react with other silanes to form the sequence of polysiloxane. These two reactive entities include, without being limited to, halogens such as chlorine, alkoxy groups containing 1 to 4, or more than 4 carbon atoms, the hydroxyl group and primary or secondary amino groups.
In the case of formula III, the silanes which are reacted with bifunctional derivatives of telomers or oligomers, or with other groups, and with the monofunctional derivatives of telomers or oligomers or with other groups, require one of the above-mentioned reactive entities on each of the two telochelating silicon atoms present at the end of the molecule represented by formula III. These reactive entities X can then be reacted with other silanes to form an alongated chain structure as mentioned above and represented by formula I.
The units V, W, Y, Z which have the structures represented in formula I can be homopolycondensed appropriately separately to form a homogenous or copolycondensed sequence with statistical sequences according to the useful techniques in silicon chemistry which are well known to the expert in the field.
The crosslinking of said copolymer silicones of formula I which contain a lateral peripheral vinyl ether group is carried out by activation with UV light in the presence of cationic photoinitiators selected from the group of salts of halonium or sulfonium or phosphonium, with the preferred photoinitiators being of the triarylsulfonium hexafluouroantimonate type.
One of the techniques proposed in the invention follows pathways (a) and (b). The intermediate 2-hydroxyethyl vinyl ether is prepared from 2-chloroethyl vinyl ether (Aldrich) using a phase-transfer reaction with sodium acetate, and hydrolysis under mild conditions with KCN. The monoisocyanato-m-tolylurethaneethylene-2-vinyl ether intermediate (1) is prepared by condensation of tolyl diisocyanate and 2-hydroxyethyl vinyl ether as described in European Patent Application No. 0 398 775, filed Nov. 22, 1990. Next, (1) is reacted with a polysiloxane having the structure (2):
C.sub.6 H.sub.5 --Si(CH.sub.3).sub.2 O[Si(CH.sub.3).sub.2 O].sub.v [CH.sub.3 Si(C.sub.3 H.sub.6 OH)O].sub.v,Si(CH.sub.3).sub.2 C.sub.6 H.sub.5 ( 2)
to yield the product (3) which contains the peripheral vinyl ether group with the following formula:
C.sub.6 H.sub.5 Si(CH.sub.3).sub.2 O--[Si(CH.sub.3).sub.2 O].sub.v [CH.sub.3 Si[C.sub.3 H.sub.6 OCONHC.sub.6 H.sub.3 (CH.sub.3)NHCOOC.sub.2 H.sub.4 OCH═CH.sub.2 ]O].sub.v '--Si(CH.sub.3).sub.2 C.sub.6 H.sub.5
Product (3) is then applied in the form of a film onto paper and crosslinked in the presence of triarylsulfonium hexafluoroantimonate to obtain an antiadhesive coating on the paper.
According to a variant of the same general technique, triethoxysilane-3-propylurethane-2-ethyl vinyl ether (prepared by condensation catalyzed by dibutyl tin dilaurate of 2-hydroxyethyl vinyl ether with 3-isocyanatopropyltriethoxysilane) was subjected to polycondensation with a polydimethylsiloxanediol in the presence of dimethylphenylchlorosilane as chain termination agent. A product (4) with the following structure was obtained:
C.sub.6 H.sub.5 Si(CH.sub.3).sub.2 O[Si(CH.sub.3).sub.2 O].sub.v --RSi(OC.sub.2 H.sub.5)O].sub.v '(Si(CH.sub.3).sub.2 O).sub.v --Si(CH.sub.3).sub.2 C.sub.6 H.sub.5
where R=C 3 H 6 NHCOOC 2 H 4 OCH═CH 2 .
After application to paper, this product (4), in the presence of triarylsulfonium salt, was crosslinked by a short exposure to UV light yielding a paper with antiadhesive properties.
According to a different technique, a polymethylvinylsiloxane was reacted with thioethyleneglycol to produce a sil-2-thio-4-hydroxy unit which was reacted with isocyanatotolylurethane-2-ethyl vinyl ether to obtain a silanoxy group with the structure (5). ##STR2## The modified polysiloxane which contains peripheral vinyl ether was activated for crosslinking by UV light in the presence of sulfonium salt.
EXAMPLE 1
Preparation of a Polysiloxane Containing Lateral Urethanevinyl Ether Groups
a) Synthesis of hydroxy-2-ethyl vinyl ether
a.1) Synthesis of acetoxy-2-ethyl vinyl ether
In a 250-mL flask equipped with cooling coil and mechanical stirring system one introduces 50 g of chloro-2-ethyl vinyl ether (Aldrich) (0.47 mol), 39 g sodium acetate (0.47 mol), and 2.2 g TBAH (tetrabutylammonium hydrogen sulfate). The mixture was stirred at 450 rpm for 12 hours at 109° C. It was then filtered, and the solid part (primarily NaCl), was washed several times with ether which was then eliminated by evaporation at reduced pressure; the product was finally distilled (bp 20 mm Hg= 72° C.). The yield obtained was 92%.
With IR (PERKIN ELMER 398): the presence of vibration bands at 1,750 (CO) and 1,620 cm -1 (--HC═CH 2 ) was observed.
1 H-NMR (250 MHz, CHCl 3 ): the peaks were assigned as follows: ##STR3##
a.2) Hydrolysis of acetoxy-2-ethyl vinyl ether
In a 250-mL flask equipped with cooling coil and magnetic stirring system one introduces: 13 g acetoxy-2-ethyl vinyl ether (0.1 mol), 1.2 g potassium cyanide (0.018 mol), 150 mL methanol RP, and 0.1 g hydroquinone.
The mixture was stirred for 12 hours at 25° C.; it was then treated with ether and filtered over Na 2 SO 4 . The solvent was then eliminated at reduced pressure. The product was prepared with a yield of 90%.
1 H-NMR (250 MHz, CHCl 3 ): the complete disappearance of the peak at 2.07 ppm ##STR4## IR: (Perkin-Elmer 398), observation of the complete disappearance of the band at 1,750 cm -1 (--C═O) and the appearance of the band at 3,350 cm -1 (C--OH).
From this one can conclude that the product obtained had the structure:
HO--CH.sub.2 --CH.sub.2 --O--CH═CH.sub.2
a.3) Synthesis of isocyanatourethane vinyl ether: ##STR5##
In a 250-mL flask fitted with nitrogen inlet, tap funnel and a cooling coil, one introduces: 9.88 g TDI (toluene diisocyanate), 100 mL anhydrous toluene, 0.1 DBDLT (dibutyltin dilaurate and 0.1 g hydroquinone. Using a tap funnels one introduces 5 g hydroxy-2-ethyl vinyl ether (7) and 10 mL toluene drop by drop for 30 minutes. The mixture is then heated to 50° C. for 5 hours. At the end of the reaction, toluene and unreacted products are eliminated by evaporation at reduced pressure (yield 98%). The NCO index was 14.2% (by weight).
IR analysis revealed: NCO band to 2,260 cm -1
Disappearance of OH band at 3,350 cm -1
Presence of --C═C band at 1,620 cm -1 and NH band at 3,320 cm -1
13 C-NMR analysis (BRUKER 80 MHz, CHCl 3 ) permitted the following assignment of peaks: ##STR6##
a.4) Synthesis of silicone-urethane vinyl ether (10)
In a flask with 2 outlets, fitted with cooling coil and a nitrogen inlet, one introduces: 8.2 g of compound (9) prepared as described below, 12 g anhydrous toluene, 2.72 g of compound (8) and 0.1 g hydroquinone. The mixture was maintained at 60° C. for 6 hours, and then the solvent was eliminated at reduced pressure.
The following product was obtained quantitatively: ##STR7## where R=--C 3 H 6 --O--CONH--C 6 H 4 (CH 3 )NH COOC 2 H 4 OCH═CH 2 and
φ=--C 6 H 5
IR (Perkin-Elmer 398) results were:
absence of OH vibration bands (3,350 cm -1 ) and NCO vibration band (2,260 cm -1 ).
presence of bands for NH (3,320 cm -1 ) and for vinyl groups (1,620 cm -1 ).
b.1) Synthesis of the compound with formula (9)
In a 500-mL flask fitted with cooling coil one introduces: 100 g α,ω-dihydroxypolydimethylsiloxane (product manufactured by the RHONE-POULENC Company: % OH=5%, Mn=680; n=8.9), equivalent to 0.147 mol part; 27.65 g acetoxy-3-propylmethyldichlorosilane (supplied by Petrarch System), equivalent to 0.129 mol part, 6.26 g phenyldimethylchlorosilane (supplied by Petrarch System), equivalent to 0.0368 mol part, 200 mL anhydrous toluene and 4 mL pyridine.
The mixture was heated to 80° C. for 24 hours, then filtered to eliminate the white precipitate and evaporated at reduced pressure to eliminate the solvent (toluene) and unreacted product. A dilution was then carried out with ethyl ether followed by repeated washing to completely eliminate the pyridine salt. The ether phase was dried over Na 2 SO 4 , filtered and evaporated at reduced pressure. The product was obtained with a yield of 95%.
This compound was analyzed by IR [spectroscopy] (Perkin-Elmer 398): the complete disappearance of the Si-OH band at 3,360 cm -1 was observed, and the appearance of the ##STR8##
The intrinsic viscosity was measured in butanone at 30° C. (K=0.048 mL/g and α=0.55)
n=8.5×10.sup.-3 mL/mg and MV≃9,200
29 Si-NMR (80 MHz, CHCl 3 ) revealed: presence of central silicon atoms at -21.9 ppm and of terminal Si atoms at -2.5 ppm, and absence of (OSi--OH) peaks at -11.8 ppm and of ##STR9##
13 C-NMR (80 MHz, CHCl 3 ) resulted in the following assignment of the peaks: ##STR10##
The hydrolysis of this compound was carried out in the presence of KCN (1 wt %) in methanol at room temperature for 24 hours. The compound was purified by washing with water-ether, then it was dried over Na 2 SO 4 , and the solvent was evaporated at low pressure. The product was obtained with a yield of 90%.
The IR results (Perkin Elmer 398) were: disappearance of the vibration band for the ##STR11## groups (b 1,730 cm -1 ) and appearance of the vibration band for the OH groups at 3,350 cm -1 .
1 H-NMR (250 MHz, CHCl 3 ) result: hydrolysis rate: 95%.
The structure of compound (9) is as follows: ##STR12##
EXAMPLE 2
Preparation of the Polysiloxane which Contains Lateral Urethane-vinyl Ether Groups (11)
Step 1--Synthesis of triethoxysilane-propylurethane vinyl ether (12)
In a 50-mL flask fitted with a cooling coil one introduces:
6 g (EtO) 3 --Si(CH 2 ) 3 NCO
2.2 g CH 2 ═CH--O--C 2 H 4 OH (7)
0.1 g DBDLT
0.05 g hydroquinone.
The mixture was stirred for 10 min at room temperature. The formation of this product was accompanied by a high release of heat.
Unreacted products were eliminated at reduced pressure. The product yield was more than 95%.
IR analysis of the product (Perkin Elmer 398) revealed the disappearance of the NCO vibration band at 2,260 cm -1 and the appearance of the NH band at 3,320 cm -1 . 1 H-NMR (250 MHz, CHCl 3 ) result; one quadruplet at 6.4 ppm (O--CH═CH 2 ). 13 C-NMR (Brucker 80 MHz) results: the peaks were assigned as follows to the structural formula (12): ##STR13##
Step 2--Polycondensation of triethoxysilane-urethane vinyl ether with polydimethylsiloxanediol in the presence of a chain terminating agent (formation of polysiloxane) (11)
In a 250-mL flask fitted with cooling coil one introduces:
13.6 g triethoxysilane-urethane vinyl ether (12) (0.0406 mol)
32 g dihydroxypolydimethylsiloxane (M=680; % OH=5%; n=8.9, or 0.048 mol), the structure of this commercial product was as follows: ##STR14##
50 mL toluene.
The mixture was stirred for 20 minutes at room temperature. Then 2.3 g of phenyldimethylchlorosilane were added; the mixture was then heated for 90° C. overnight.
Unreacted products were evaporated at reduced pressure (0.005 mm Hg at 140° C.).
44 g of (11) were obtained: ##STR15## where R═C 3 H 6 --NHCOOC 2 H 4 OCH═CH 2 and φ═--C 6 H 5 .
The results of IR analysis (Perkin Elmer 398) were: presence of NH bands (3,320 cm -1 ), and the band for the double bond at 1,620 cm -1 .
13 C-NMR (80 MHz, CDCl 3 ) revealed: peaks at 151.5 and 86.9 ppm (--CH═CH 2 ), peaks at 11.3; 23.7 and 43.77 for the carbon atoms at α, β and γ of Si, and the peak at 1.0 ppm for the different carbon atoms attached to the Si atom.
EXAMPLE 3
Polycondensation of Triethoxysilane-urethane Vinyl Ether with 1'α,ω-dihydroxypolydimethylsiloxane Without Chain Terminating Agent (Polysiloxane (13))
In the same apparatus as above one introduces 8.04 g triethoxysilane-urethane vinyl ether (12) and 127 g α,ω-dihydroxypolydimethylsilane (Mn=3,580; % OH=0.95) with the formula HO[(CH 3 ) 2 SiO] 48 --H, followed by addition of 100 mL of toluene, the mixture is then heated to 80° C. overnight. After elimination of the solvent at reduced pressure, the ether is then diluted, and activated charcoal is added; the entire mixture is then heated to the boiling point for 30 minutes. The mixture is then filtered over Na 2 SO 4 and silica. The ether is evaporated and the product consists of 130 g of viscous compound (13) with the structure: ##STR16## where R=(CH 2 ) 3 --NHCOOC 2 H 4 OCH═CH 2
The same IR and 13 C-NMR characteristics were observed as for the product of Example 2, Step 2.
EXAMPLE 4
Preparation of a Polysiloxane which Contains Lateral Thioether-urethane Vinyl Ether Groups (14)
Step 1--Preparation of a polydimethylsiloxane (15) which contains primary hydroxy groups
In the 500-mL flask fitted with the cooling coil and a nitrogen inlet one introduces:
100 g of a copolymer of dimethylsiloxane and methylvinylsiloxane (η=1 Pa.s; %[OSi(CH 3 )CH═CH 2]= 7.5%, supplied by Petrarch System)
21.7 g thioethanol (MERCK) and 0.6 g AIBN, and 200 mL toluene.
The mixture was heated to 70° C. for 6 hours. Then solvent and unreacted products were eliminated by evaporation at reduced pressure. 118 g of product e 1 were obtained. ##STR17## where R=CH 2 CH 2 --S--CH 2 CH 2 OH and
n 1= 348
n 2= 25.
1 H-NMR analysis (250 MHz, CDCl 3 ) revealed the complete disappearance of vinyl protons at 6.0 ppm and the appearance of multiplets at 0.9 and 2.6 ppm in α and β positions of the Si atom and at 2.7 and 3.6 ppm in the α and β positions of the hydroxyl group.
13 C-NMR (80 MHz, CDCl 3 ) permitted the assignment of the peaks corresponding to group (16) as follows: ##STR18## The content of OH groups of the product was 1.2%.
Step 2--Polysiloxane (14)
In a 100-mL flask fitted with cooling coil and a nitrogen inlet the following quantities of the following ingredients are introduced:
10 g of product (15) prepared in Step 1, 1.9 g of product (8), 50 mL of anhydrous toluene and 0.1 g hydroquinone.
The mixture was stirred and heated at 60° C. for 6 hours. The reaction mixture was treated as in Example 1, Step (a 4 ). The yield was quantitative.
IR analysis (Perkin-Elmer 398) results:
Disappearance of NCO band at 2,260 cm -1
Appearance of NH band at 3,380 cm -1
Appearance of vinyl band at 1,620 cm -1
The structure of compound (14) was as follows: ##STR19## where n 1= 348, n 2= 25 and
R=CH.sub.2 CH.sub.2 --S--CH.sub.2 CH.sub.2 --OCONHC.sub.6 H.sub.3 (CH.sub.3)--NHCOO--C.sub.2 H.sub.4 --O--CH═CH.sub.2
EXAMPLE 5
Preparation of a Polysiloxane which Contains Fluorinated Lateral Groups in the Chain (Product (17))
One introduces into a flask: ##STR20##
n=48 and % OH=0.95
2.07 g CH 2 ═CH--O--C 2 H 4 --OCONHC 3 H 6 Si(OEt) 3 (product (11) of Example 2) (0.0062 mol).
1.17 g C 6 F 13 C 2 H 4 OC 3 H 6 Si(OEt) 3 (0.0021 mol).
The reaction is conducted and treated in the same manner as for product (13).
1 H-NMR and 13 C-NMR confirmed the following structure of the polymer (17) obtained: ##STR21## where R v =C 3 H 6 --NHCOOC 2 H 4 OCH═CH 2
R F =C 3 H 6 OC 2 H 4 C 6 F 13
n=48.
This product is soluble in most organic solvents such as CHCl 3 , methyl ethyl ketone, CCl 4 , and acetone. IR analysis revealed the presence of vibration bands for vinyl at 1,620 cm -1 and for NH at 3,300 cm -1 .
EXAMPLE 6
Preparation of a Polysiloxane which Contains Fluorinated Groups in the Chain and at the Ends (18)
In a 250-mL flask fitted with cooling coil, one introduces: ##STR22## equivalent to 0.044 mol
11.82 g R V Si(OEt) 3 (12), or 0.035 mol
7.51 g R F Si(OEt) 3 , or 0.013 mol, and
0.5 g tetramethylguanidine.
The reaction is conducted and treated in the same manner as for Example 6.
40 g of a viscous product are obtained, which, as shown by the IR spectrum, agrees with the following formula (18): ##STR23## where R F =C 6 F 13 C 2 H 4 OC 3 H 6
R v =--C 3 H 6 NHCOOC 2 H 4 OCH═CH 2
n=8.9.
The theoretical Mn was approximately 10,500.
EXAMPLE 7
Preparation of a Polysiloxane which Contains Fluorinated Lateral Groups and Lateral and Terminal Urethane-vinyl Ether Groups (19)
Step 1
In the same apparatus as above one introduces: ##STR24## Mn=680) (0.073 mol),
11.44 g C 6 F 13 C 2 H 4 OC 3 H 6 SiCH 3 Cl 2 (0.022 mol),
9.48 g AcOC 3 H 6 SiCl 2 CH 3 (0.0441 mol),
2.86 g AcOC 3 H 6 SiCl(CH 3 ) 2 (0.0147 mol), and
1 g tetramethylguanadine. The reaction was conducted and treated as above.
The structure of the product obtained was as follows: ##STR25## where R F =C 3 H 6 --O--C 2 H 4 --C 6 F 13 and
R=C 3 H 6 --OCOCH 3
Step 2: hydrolysis of (20) to prepare (21)
The product obtained in the first step is reacted in the presence of 0.4 g KCN in 100 mL CH 3 OH (RP) for 24 hours at room temperature.
Step 3: Grafting of ω-isocyanate vinyl ethers
10 g of product (21) are added to 1.96 g of vinyl ether-ω-isocyanate (8) and 60 mL of toluene in a nitrogen atmosphere. The reaction lasted 5 hours at 40° C. A waxy yellowish product (19), which was soluble in butanone, was obtained.
The analysis showed that product (19) agreed with the following formula: ##STR26##
EXAMPLE 8
Preparation of the Polysiloxane which Contains Fluorinated Lateral Groups and Urethane-vinyl Ether and which has Dimethylphenylsilane Ends (22)
One reacts: 50 g ##STR27## (n=8.9) 0.073 mol),
12.5 g C 6 F 13 C 2 H 4 OC 3 H 6 SiCl 2 CH 3 (0.024 mol),
9.3 g AcOC 3 H 6 SiCl 2 CH 3 (0.043 mol), and
2.1 g φSiCl(CH 3 ) 2 (0.012 mol).
After condensation in the presence of a salt of tetramethylguanadine and hydrolysis in the presence of KCN (CH 3 OH) one obtains a fluorinated polysiloxane which contains lateral OH groups (23).
One reacts 10 g of this polymer (23) in 20 mL toluene and 1.5 g vinyl ether-ω-isocyanate (8) at 50° C. for 4 hours in nitrogen to obtain a yellowish viscous liquid (22), whose analysis showed that it agreed with the following formula: ##STR28##
EXAMPLE 9
Preparation of a Polysiloxane which Contains Fluorinated Groups in the Chain, Lateral Fluorinated and Urethane-vinyl Ether Groups, and which has Dimethylvinylsilane Ends (24)
The silanediol
CF.sub.3 C.sub.2 H.sub.4 (CH.sub.3)(HO)SiC.sub.2 H.sub.4 C.sub.6 F.sub.12 C.sub.2 H.sub.4 Si(CH.sub.3)C.sub.2 H.sub.4 CF.sub.3 (OH) (25)
was prepared according to a method described by Y. Kim in Rubber Chem. Technol. (1971), 1350, by hydrosilylation of CH 2 ═CHC 6 F 12 CH═CH 2 with 3,3,3-trifluoropropylmethylchlorosilane, followed by hydrolysis.
One reacts 12 mol parts of silanediol (25) with 4 mol parts C 6 F 13 C 2 H 4 OC 3 H 6 SiCl 2 CH 3 , 7 mol parts AcOC 3 H 6 SiCl 2 CH 3 , and 2 mol parts C 6 H 5 SiCl(CH 3 ) 2 as described in Example 8. After hydrolysis of the silicone in the presence of KCN/CH 3 OH and reaction with compound (8), as described in Example 8, one obtains a product (24) which had the following structure: ##STR29## where R F and R are as described in Example 8.
EXAMPLE 10
Preparation of the Polysiloxane which Contains Lateral Fluorinated Groups and Lateral and Terminal Urethane-vinyl Ether Groups
Step 1: One introduces in a 250-mL flask: ##STR30## 19.86 g Cl 2 (CH 3 )SiC 3 H 6 OC 2 H 4 C 8 F 17 (0.032 mol) (26), 1.53 g Cl 2 (CH 3 )SiC 3 H 6 OCOCH 3 (0.0071 mol), 1.384 g Cl(CH 3 ) 2 SiC 3 H 6 OCOCH 3 (0.0071 mol), 0.1 g tetramethylguanidine.
Product (26) was prepared as follows:
from C 2 F 5 I, by telomerization of TFEE at 200° C., one obtains the telomer C 2 F 5 (C 2 F 4 ) 3 I (27) which one separates by distillation from the other telomers. Product (27) was reacted with the C 2 H 4 at 120° C. in the presence of CuCl/ethanolamine producing C 8 F 17 C 2 H 4 I which was hydrolyzed with 30% oleum to be converted to C 8 F 17 C 2 H 4 OH (28). Product (28) was reacted with allyl chloride in the presence of tetrabutylammonium hydroxide and soda (20N). After distillation the product obtained is C 8 F 17 C 2 H 4 OCH 2 --CH═CH 2 (29). One reacts product (29) with HSi(CH 3 )Cl 2 in the presence of H 2 PtCl 6 (at 50% in isopropanol) in hexane at 70° C. for 24 hours and, after distillation of the solvent, one distills the final product in a vacuum (26).
The polycondensation reaction between ##STR31## and the precursors mentioned above was conducted at 70° C. for 18 hours while keeping the reaction in a 20 torr vacuum. The product was diluted with ether and filtered, and after evaporation of the solvent in a vacuum, one obtained 34.75 g of very viscous product which contains 31.5 wt % fluorine.
IR analysis has shown the presence of acetate groups (1,740 cm -1 region) and also of other units present in the structure (30). ##STR32## where n=54; n'=9, n"=2
R=C 3 H 6 OCOCH 3 .
This structure corresponds to the theoretical percentage by weight of fluorine of 29.9% and to a MW=9720.
Step 2
The product (30) was hydrolyzed in the presence of KCN in methanol to prepare a product (31) which presented a total conversion of acetate groups to free hydroxyl groups.
Step 3
Polysiloxane (31) with free, lateral and terminal hydroxyl groups was reacted with vinyl ether-ω-isocyanate (8) to obtain product (32): ##STR33## where R'=C 3 H 6 OCONHC 6 H 3 (CH 3 ) NHCOOC 2 H 4 OCH═CH 2 and where n, n', and n" are the same as in (30).
EXAMPLE 11
Use of Polymers According to the Invention for the Production of Crosslinked Coatings with Antiadhesive Properties
Coating compositions were prepared by dissolving a polymer according to the invention, and a photosensitive catalyst in a solvent in the proportions indicated in the table below, and these compositions were applied to kraft paper using a manual applicator consisting of a threaded rod, in quantities indicated in said table (in g/m 2 ). The applied coat was crosslinked by exposure to a UV lamp (80 W/cm 2 ) for the time indicated in the table. In all cases a paper with antiadhesive properties was obtained from which adhesive ribbons could be removed easily. In addition, there was no trace of migration, from the antiadhesive film of the silicon polymer of the invention to the adhesive ribbon, because the latter remained capable of adhering to itself. These antiadhesive properties were preserved even after storage for 24 hours of the treated papers in an oven at 60° C.
TABLE__________________________________________________________________________ Weight Time of Polymer Solvent Catalyst of Coating ExposureComposition Type Quantity, g Type Quantity, g Type Quantity, g g/m.sup.2 to UV, sec__________________________________________________________________________A (10) (Ex. 1) 1 MEK 1 φ.sub.3 S.sup.+ SbF.sup.-.sub.6 0.05 8.8 3B (10) (Ex. 1) 0.5 CHCl.sub.3 0.7 φ.sub.3 S.sup.+ SbF.sup.-.sub.6 0.04 4.3 3C (11) (Ex. 2) 1.85 -- -- φ.sub.3 S.sup.+ SbF.sup.-.sub.6 0.07 15 5D (13) (Ex. 3) 2.2 -- -- φ.sub.3 S.sup.+ SbF.sup.-.sub.6 0.15 14 5E (17) (Ex. 5) 2 MEK 0.4 φ.sub.3 S.sup.+ SbF.sup.-.sub.6 0.06 12 3__________________________________________________________________________
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The invention relates to copolymers of siloxanes with the formula:
(R.sub.a).sub.3 SiO(V).sub.v --(W).sub.w --(Y).sub.y --(Z).sub.z
--Si(R a ) 3
where
V=SiR a R b O--;
W=SiR' a (R c --R d --OCH═CH 2 )O--;
Y=SiR a R g O--;
Z=R a R g SiC n H 2n R' f C n H 2n SiR a R g O-- where n=2, 3 or 4;
v, y, z=0 or an integer, w≠0 with v+y+z≠0;
R a =alkyl or phenyl; R b =R a ; R' a =R a or alkoxy; R c =alkylene, for example:
R d =--OCONHR e NHCO--, --NH--COOC 2 H 4 --, or --NHCOOC 3 H 6 --;
R e =divalent hydrocarbon radicals; R g , R f and R' f are fluorinated or perfluorinated radicals.
The above copolymers are used for the preparation of antiadhesive coatings, for example on paper.
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FIELD OF THE INVENTION
This invention relates to agricultural implements. More particularly, to implements for laying and retrieving/retracting protective netting and other crop protection materials onto/from agricultural crops, including, but not limited to berries, kiwi, apples, grapes, or any other crop which is grown in a row formation or on a trellis, to protect the plants from predators and/or other potential damage from weather i.e., frost, rain, hail, wind and sun, and to enhance growth and productivity.
BACKGROUND OF THE INVENTION
Implements for applying protective coverings on various surfaces have been previously known and used. Many devices have been used in agriculture for laying a covering on the ground or protecting certain types of agricultural plants. Typically, these devices are used in conjunction with a tractor and a normal hitch system utilizing hydraulic equipment.
The main purpose of the protective coverings of the present invention is the prevention of damage caused by particular animals, most notably birds, which feed on the various agricultural plants, most particular finches, starlings and sparrows, and by other potential damages as the result of weather i.e., frost, rain, hail, wind and sun. In the case of vineyards, the birds feed on the foliage and grapes, eventually damaging the crop. By applying a protective covering over the plants, the nuisance birds are prevented from damaging the crop and the crops are protected from damaging weather. The present invention is directed at applying and retrieving such protective coverings.
Typically, large bulk rolls of coverings have been dispensed on, or retrieved from, crops by elevating the rolls above the crops and unrolling/retrieving the covering onto the crops. Due to the great weight and unwieldy nature of the roll, this method may be quite dangerous and difficult. The present invention provides an easier and more controlled method, in that the bulk rolls are placed low to the ground for greater safety and stability and the reusable coverings may be retrieved onto small spools that are easy to manhandle, move and store and reuse.
Some machines that spread or provide covering for plants include the following:
U.S. Pat. No. 3,395,485, issued to Ricklidge on Aug. 6, 1968, discloses a crop protecting plastic dispensing mechanism attachment for a tractor or jeep which is moved between rows of fruit trees and dispenses a thin layer of plastic from a large roll through rollers and over the row of trees.
U.S. Pat. No. 1,957,994, issued to Eccher on May 8, 1934, discloses a motorized wheeled frame for dispensing covering material from a roll on the frame over trees in an orchard.
U.S. Pat. No. 4,318,514, issued to Weberg on Mar. 9, 1982, discloses a machine for applying and retracting a protective covering to agriculture plants. The implement is supportively attached by forward and rearward attachment mechanisms to a tractor and movably supported additionally by a coaster wheel laterally spaced from the tractor. Vertically oriented supports and rearward attachment mechanisms and front attachment to a wheel to support a horizontally oriented, substantially rectangular frame. A rotatable shaft mechanism attached to a universal joint is supported at the ends by shaft supports which extend upwardly from the rearward portion of the frame.
U.S. Pat. No. 3,791,069, issued to Nelson on Feb. 12, 1974, discloses an orchard tree covering device for use in placing individual covers or strips of cover material over orchard trees to prevent frost damage. The device is adapted to fit on conventional tractors and includes an adjustable elevational support and a cover holding magazine. The magazine is designed to hold a plurality of covers and includes means for selectively releasing individual covers onto trees below. In an alternate form, the covers are connected in trips and rolled onto spools. The strips may then be reeled out by the device over long rows of trees.
The present invention provides improved implements and methods of laying and retrieving protective covering materials over crops to prevent damage to said crops.
SUMMARY OF THE INVENTION
The present invention provides improved implements and methods for dispensing and retrieving protective crop covering materials (PCCM), such as, but not limited to, netting, such as bi-axially oriented polypropylene netting, films, such as blown poly films, ether cloth fabrics, plastic sheets and woven or nonwoven fabrics, on/from crops, particularly vineyard crops, to protect the plants from nuisance birds and weather conditions which cause damage to the crops. Basically, there is disclosed herein a system for layout of PCCM from a bulk roll of PCCM onto crops, a system for retrieving the PCCM from the crops and disposing it or storing said PCCM on reusable spools and a system for layout of the PCCM from the reusable spools.
The bulk roll layout system generally consists of a rolling cradle utilizing powered or idler rollers to layout bulk rolls of material from a low ground profile, wherein the roll is carried between and parallel with the rows of crops, up and over the crop through a sweep attached to a tower which reduces the material as it leaves the rolls and enters the sweep and then expands the material as it is introduced onto the crop row. This rolling cradle can be mounted on a dedicated trailer or in a frame that is designed to attach to a standard trailer.
The retrieval system consists of a hydraulically driven arbor shaft (preferably a 11/2 arbor shaft) that accepts spools for retrieval of PCCM for reuse or disposal. The shaft is mounted into a frame that is then hitched to a tractor. The PCCM is retrieved evenly onto plastic spools for reuse at a later time or onto a permanent spool that facilitates disposal in tightly compacted rolls. PCCM is pulled off the vine row utilizing the same tower and sweep arrangement used in the above mentioned bulk roll laying system. This tower arrangement is manipulated over the rows of crops by attaching it to the same frame that carries the retrieval head. Again, the material is brought from a low position in the row, elevated over the row, reduced and then expanded. In retrieving the product the opposite action takes place in that the material is lifted off the row, run through the tower sweep, reduced and put back on the spool which again is at a ground level profile.
In the system for layout of the PCCM from the reusable spools, the reusable spools of wound PCCM are taken from storage and reused by unrolling them onto the rows of crops. The system is basically the same as that of the retrieval system except that the spool of wound PCCM is mounted on the tower rather than the sweep and allowed to unroll onto the crops.
The object of the present inventions is to efficiently and effectively layout, retrieve and store PCCM, which are used to protect crops from nuisance animals, most notably vines from particular birds, and damaging weather.
A further objective is to provide a system which minimizes crop damage during the covering and uncovering process.
A further objective is to provide a crop covering system that utilizes elements, some of which were formerly thought to be single use items, which may be easily stored and reused and inexpensive machinery, which reduces manual labor and increases speed of application and retrieval of the coverings.
A further objective is to provide such a device that is adapted to be mounted to conventional farm tractors.
A further objective is to provide a system of applying crop protection materials from a low to ground profile to up and over the row so that the majority of the weight of the material is close to the ground both in laying out and retrieving material instead of being suspended above the crops.
A further objective is to provide a method of handling protective coverings that does not require the use of special material handling equipment
These and other objects and advantages will become evident upon reading the following description which, taken with accompanying drawings, describe a preferred and alternate embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of a protective covering layout system.
FIG. 2 is a detailed view of a sweep.
FIG. 3 is a blow-up proportional view of a sweep.
FIGS. 4-5 are perspective views of a dispersing guide.
FIG. 6 is an illustrative demonstration of a laying of netting upon targeted crops.
FIG. 7 is a rear perspective view of a protective covering layout system in progress.
FIG. 8 is a top view of a protective covering layout system in progress.
FIG. 9 is a perspective view of a protective covering retrieval system.
FIG. 10 is a perspective view of a levelwind system.
FIGS. 10a and 10b are illustrative views of the arbor shaft and the bolted flange.
FIG. 11 is a perspective view of a proximal half of a permanent spool.
FIG. 12 is a perspective view of a distal half of a permanent spool.
FIG. 13 is a perspective view of the resulting wound netting after retrieval.
FIG. 14 is a perspective view of an alternative protective covering layout system utilizing a reusable distribution spool of netting.
FIG. 15 is a detailed perspective view of a mounted distribution spool.
FIG. 16 is an illustrative view of mounting clamps mounting multiple booms onto a tower.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention discloses generally a bulk PCCM (for the purpose of discussing the drawings and the embodiments below, netting will be used as an example of the PCCM, but it should be known that any PCCM may be used) roll layout system, a net retrieval system for disposal or reuse and a spooled roll layout system. The layout and retrieval systems incorporate a low profile carrier for bulk rolls or individual spools which may be stored and reused. Such a low profile carrier provides a safe method for transporting rolls or spools through fields and facilitates ease of loading and unloading.
FIGS. 1-4 disclose a tower and sweep arrangement that places netting over vine rows for protection of said rows. FIG. 1 illustrates the bulk netting roll layout system (BRLS), generally designated as 10. The BRLS carries a bulk roll of netting and dispenses the netting over crops. The BRLS consists of a trailer 12 which may be hitched to a tractor 14 (not fully shown) via a standard hitch system 16, which incorporates an optional auxiliary hydraulic system 18. The trailer 12 carries a rolling cradle 20, which may be configured and constructed to accept any type of roll or spool of covering, utilizing powered or idler rollers 21,22, powered by the hydraulic motor 46 which is driven by the hydraulic system 18. The rolling cradle 20 carries and lays out the bulk roll 24 (may also carry spools) of netting. To form the tower, a pole 26 is also mounted on the trailer 12 and supports a boom 28 at approximately a 90° angle. It should be understood that the tower be of such construction as to suspend the sweep over the row of crops and not limited to a particular angle. A guiding ring 30 is connected to the boom 28 to guide the netting 25 from the bulk roll 24, as seen in FIG. 1, into a sweep 32, also mounted on the boom 28, which guides and redirects the netting 25 90° (It should be understood that the sweep be of such construction as to direct the netting into alignment with the row of crops and not limited to a particular angle). As the netting 25 exits the sweep 32 it is then guided through a dispersement guide 34, which is also mounted to the boom 28. The dispersement guide 34 aids in the laying of the netting by spreading the netting from it's "roped" configuration as it exits the sweep 32 to a "fanned" configuration to cover the crops more effectively.
The preferred trailer 12 is as shown in FIG. 1. The trailer 12 should be a low profile trailer which may be towed between rows of crops. The trailer may be towed via a tractor 14 utilizing a standard hitch 16. The trailer's 12 purpose is carry the bulk roll 24 and facilitate laying of the netting. As such, the trailer is constructed to provide such a function. The trailer 12 (in this example a bin trailer) is preferably a heavy duty (steel) mobile (tires 37) frame 36 which may support a standard roll of netting, which can be approximately 200 to 1000 pounds. Preferably, the trailer should be able to support two rolls for dual dispersement/retrieval or just to have an extra roll when the first is completed.
The rolling cradle 20 can be mounted on a dedicated trailer or in a frame that is designed to attach to a standard 4-row vineyard/orchard trailer or a bin trailer. The purpose of the rolling cradle 20 is to support and rotate the bulk roll of netting 24. The cradle 20 consists of two parallel rollers 21,22, preferably PVC rollers, rotatively mounted at either end to a support frame 38, which is connected to or integral with the trailer 12. The support frame 38, preferably is a heavy duty metal of a welded tube type, Structural Grade, A-500-72 Gr. B. The forward and rear ends of the rollers 21,22 are rotatably connected, preferably via 11/2 inch stub axle and flange bearings, to T posts 40,41 in parallel fashion to receive a bulk roll of netting 24. Retaining posts 42,43 are also connected to the support frame 38 and aids in retaining the bulk roll 24 in place on the rollers 21,22 to prevent longitudinal sliding of the roll 24. Support rollers, 44, 47 (the right support roller 47 shown is shown in FIG. 8, and is a mirror image of support roller 44) are also mounted on posts which are mounted on frame 36 to support rollers 21,22, to prevent outward bowing of the rollers 21,22, under the weight of the bulk roll 24. The support frame 38 should be longitudinally adjustable to adapt to longer rollers 21,22 and bulk rolls 24.
The rollers 21,22 are preferably driven in a clockwise and counter clockwise direction, respectively, to rotate the bulk roll 24 to release the netting 25, by a close coupled orbital motor 46 with a pressure compensated flow control. A conventional hydraulic system 18 may be used to control the rotation from the tractor 14. Due to the great weight of a bulk roll 24, typically at least one of the rollers 21,22, or both in unison, or the bulk roll 24 itself, should be rotatably driven. Bearings may be incorporated to roll the rollers 21,22, driven merely by the drag of the netting 25 over the crops. The rolls may also be ground driven. The drive means may be constructed in other manners, as long as the bulk roll 24 may be controllably unrolled so as to not bind up or damage the crops. Conventional motors and hydraulic control systems are well known to achieve this task.
The support pole 26 is also vertically mounted on the trailer 12, frame 36, and preferably is a heavy duty metal of a welded tube type, Structural Grade, A-500-72 Gr. B. Also preferably, the tower 26 is round in shape to accommodate vertical adjustment of the boom 28, via a vertically adjustable mount/clamp 27, most preferably a sliding mount, upon which the boom is mounted.
The boom 28 as such is vertically slidably mounted on the support pole 26. The boom 28 extends substantially perpendicularly from the support pole 26 as well as from the direction of the trailer 12. The boom, as illustrated, supports the guidance elements (30, 32, 34) such that the netting may be laid from directly above the crops.
The guiding ring 30 is adjustably, preferably slidably, mounted on cross bar 48, via an adjustable mount/clamp 49. The cross bar is in turn connected to the boom 28, preferably slidably/adjustably along the length of the boom 28. The guiding ring 30 is not only adjustable along the length of the cross bar 48, but also adjustable around the axis of the cross bar 48. As stated above, the guiding ring 30, aids in collecting and directing the netting 25 into the sweep 32.
The sweep, or collector tube, 32, as seen in FIGS. 1-3, is essentially a guiding tube made of any rigid material, preferably steel having a plastic wear liner. The netting 25 is fed into the sweep 32 and is rerouted by about 90° to align the netting 25 with the rows of crops. The sweep, as seen in FIGS. 1-3, comprises a curved tube 32 having a conduit 50 therethrough and an entry end 52 and an exit end 54. The tubing is curved in about a 90° angle, or at an appropriate angle as mentioned above, and is supported by a support bar 56, which is secured to the tubing 32 at the entry end 52 and at the exit end 54. The support bar 56 is connected to an additional cross bar 58 which is mounted in a double adjustable mount/clamp 60 which allows for adjustable/slidably movement along both the cross bar 58 and the boom 28. The sweep 32 may, at its entry end 52, or at both ends, a periphery washer-like ring or trumpet-like configuration to aid in the feeding of the netting 25 into the sweep 32. When the netting passes through the sweep it ropes down to a narrow configuration and as a result becomes abrasive. As such, the sweep should be lined or at least have a protective insert at the entry end of the sweep. Preferably, the sweep 32 is steel having a Ultra High Molecular Weight (UHMW) polyethylene insert 62 to prevent wear on the sweep 32 and on the netting 25, as shown in FIGS. 2-3. The insert 62 comprises a trumpet-shaped interior conduit 64, a stepped-up rim 66 and an engagement portion 68 which snugly fits within the entry end 52 of the sweep 32. The insert 62 prevents wear of both the sweep 32 and the netting 25 itself. To further protect the netting, an inside liner with a low coefficient of friction may also be incorporated to line the fill length of the sweep conduit 50.
After the netting has been rerouted and exits the sweep 32, it is allowed to fan out/disperse and is guided over the crop rows by the dispersing guide 34. The dispersing guide 34 is mounted on a third crossbar 70 which in turn is slidably secured to the boom 28 via a second double adjustable mount/clamp 61 which allows for adjustable/slidably movement along both the cross bar 70 and the boom 28. The arcuately-shaped dispersing guide (elongated kidney-shaped guide) is further illustrated in FIGS. 4-5. As can be seen, the arc of dispersing guide 32 is preferably and substantially in a vertical plane and has a supporting cross bar 72 connecting the ends of the dispersing guide. Preferably, the supporting cross bar 72 has a securing post 74 extending from the cross bar 72 inwardly in relation to the arc of the dispersing guide 34 and adjustably and releasably mounted to the (may be welded thereto) cross bar 70 via an adjustable mounting brace 76, which perpendicularly is mounted on the end of the cross bar 70 (seen in phantom in FIG. 4). The securing post 74 may also be welded to the end of the cross bar 70 as seen in FIG. 1. The securing post 74 may also extend from the cross bar 72 outwardly in relation to the arc of the dispersing guide 34 and mounted on the end of the cross bar 70 as seen in FIG. 5, via a conventional mounting brace or via welding. Said mounting brace receives the securing post 74, as seen in FIG. 4, and is secured by tightening screws 73. The spread of the netting may be somewhat controlled by varying the size of the dispersing guide 34 and the acuteness of the curvature of the guide 34.
Preferably, before beginning laying netting over a particular row of crops, the end of the netting should be anchored at the starting end of the row. After the netting is initially unrolled from the bulk roll 24 and fed through the guide ring, the sweep and the dispersing guide, the end of the netting is gathered together and preferably bound, such as with duct tape (whipping). The end is then anchored by a secured body, such as a post 8 at the end of a crops row 9, as illustrated by FIG. 6. The anchoring of the end of the netting allows for tension in order to achieve a smooth, secure covering of the crops.
FIG. 7 further illustrates a rear view of the working apparatus and how the apparatus of the present invention smoothly and efficiently covers the row of crops as the tractor tows the trailer between the rows. Notice should be made to the numerous amount of adjustable elements incorporated in the device such that the height and width of the rows can be accounted for.
FIG. 8 still further illustrates a top view of the working apparatus.
The system illustrated above in FIGS. 1-8 can also be modified to accept and disperse other various holders or carriers of protective covering materials, such as smaller rolls or spools. The cradle need only be designed to allow the carrier to unroll at a controlled rate such that the protective covering is evenly dispersed onto the row of crops without creating too much or too little tension. For example, for smaller bulk rolls and spools a smaller cradle system may be used or, if the carrier incorporates a bore, as with conventional spools, a support may be constructed on the frame to suspend the carrier so that it may freely unroll or unroll in a controlled manner in cooperation with the speed of the tractor, such as with a hydraulically controlled rotation system, similar to the system mentioned above. In any case, by carrying the carrier on the trailer, low to the ground and feeding the protective covering up through the tower/sweep arrangement, better and safer control may be maintained.
FIGS. 9-13 illustrate the protective covering retrieval system 100, specifically the method and apparatus for retrieving the netting after it has been laid for disposal or to reuse in a reverse manner. Generally, this system consists of a hydraulically driven arbor shaft that accepts spools for retrieving netting for reuse or disposal. The shaft is mounted into a frame that is then hitched to a tractor. The netting is retrieved evenly onto plastic spools for reuse at a later time or onto the permanent spool that facilitates disposal in tightly compacted rolls. Netting is pulled off the vine row utilizing the same tower and sweep arrangement used in the above mentioned bulk roll laying system. This tower arrangement is manipulated over the rows of crops by attaching it to the same frame that carries the retrieval head.
Referring to FIG. 9, the tractor 114 carries a three point implement, herein referred to as trailer 112, via a standard hitch 111, preferably a category II 3-point mount, in such a manner by which the trailer 112 may be suspended slightly above ground during movement. The trailer 112 comprises a frame 113 which supports a level wind system 115 which receives spools 116 for retrieving the netting 125 in an even, tight package. The frame 113 also supports a deck/screen 118 to hold empty or full spools or rolls of wound netting for disposal. For the tower, a vertical support pole 120, which is also supported by the frame 113, in turn supports a boom 122 and an angled sweep 132 (preferably a 4-inch EMT (electrical metallic tubing) 90° Sweep with a UHMW wear liner). As the tractor moves forward between the rows, the netting is lifted from off the row of crops, through the sweep and reeled evenly onto a spool. Each element of this system is discussed separately and in more detail below.
The trailer 112 comprises a frame 113, which is a welded tube type structure, preferably structural grade, A-500-72 Gr. B. As mentioned above, the trailer is coupled to the hitch of the tractor, preferably via a category II 3-point mount which allows the driver to raise the frame when in motion and lower the frame 113 when idle.
The level wind system 115 and the raising and lowering of the frame is driven by a conventional tractor and tractor auxiliary hydraulics, both of which are well known. As shown in FIG. 9, the rear of the frame 113 forms a deck or screen 118 to hold empty or full spools or rolls of wound netting for disposal. The frame 113 also comprises skids 124 which support the frame when at rest.
The frame 113 further supports a mounting bracket standard 126, which is vertically mounted thereon. The support pole 120, which is similarly discussed above, is vertically mounted on the bracket standard via adjustable clamp 128. The support pole 120 may be vertically adjusted by loosening and tightening the adjustable clamp 128.
A boom 122 is horizontally mounted to the support pole 120 via an adjustable T clamp 133. The T clamp 133 may be loosened or tightened to adjust the length of the boom 122 on either side of the T clamp 133. As shown in FIG. 9, the boom 122 supports the sweep 132. The sweep 132 is basically configured as described above in the net laying system, except that it is reversed in its direction. The entry end 152 (the gathering fairlead) faces the crops, from which the netting is drawn, and the exit end 154 faces the level wind system 115, to which the netting is retrieved. Otherwise, the sweep 132 is attached to the boom 122 as discussed above in the net laying system.
The frame 113 also supports a level wind system 115 which is hydraulically actuated via a chain drive and incorporates a mounted rotating shaft, an oscillating linear actuator and removable PVC wear guides. The drive system which rotates the spools is preferably a close coupled orbital motor with down stream pressure sensing flow control which may be controlled through the tractor's hydraulic system by the driver.
FIG. 10 shows a more detailed view of the level wind system mechanism 115. In this embodiment, the netting is reeled onto a permanent spool 116, which is preferably constructed from formed and welded 12 gage HR steel, having a bolt on flange mount 117 for attachment to the arbor shaft 166. The bolt on flange mount 117 secures the spool 116 the arbor shaft 166 and is further illustrated in FIGS. 10a and 10b. The bolt on flange 117 is welded to the arbor shaft and bolted to the spool 116 The level wind system comprises a level wind housing 140 mounted upon the frame 113, wherein the level wind housing 140 is preferably in the configuration of an upside down L (herein referred to as short leg of the L 146 and long leg of the L 148) such that the loaded spool 116 is facially exposed the exit end of the sweep to best receive the gathered netting 144. The short leg 146 has a secured access lid 147 and houses a levelwind axle 156 and a level wind follower 154 which oscillates back and forth along the level wind axle 156. A guide 158, preferably a pair of parallel rods which are preferably tubular, are connected at one end to the levelwind follower 154 and extend at an angle downward across the open face of the spool 116 as shown in FIG. 10. The guides 158 oscillate back and forth across the face of the spool 116 allowing for even reeling of the gathered net 144, which travels between the pair of rods of the guide 158. The levelwind axle 156 is coupled to a levelwind driven sprocket 160, which in turn is driven by a levelwind belt 162 which communicates the levelwind driven sprocket 160 in motion with a levelwind drive sprocket 163 which is driven by an orbit motor 164. The orbit motor 164 also drives the spool axle 166 which in turn rotates the spool 116. As mentioned above, the motor 164 is preferably hydraulically powered, and, in this particular embodiment a selector valve 168 is mounted on the outer surface of the long leg 148 to regulate the hydraulic system and as such, the speed of the orbit motor 164. Since the orbit motor 164 drives both the rotation of the spool 116 and the levelwind follower 154, they move in cooperation to evenly reel the netting.
FIGS. 11-13 illustrate in a more detailed fashion the two part permanent spool 116 and the reeled gathered netting 170. As shown in FIGS. 11-12, the spool 116 has basically two parts, a distal half 172 and a proximal half 174, both having a bore 176 therethrough to accept the axle 166. Both halves, as illustrated, have truncated cone portions 178,180, a flange 182,184 on the base of the cones and a flat top portion 186,188. To secure the cone portions 178,180 on the axle 166 to form the spool 116, a locking lug 190 is provided in the distal half 172. The locking lug 190 has a locking lug lever 192 at its proximal end and extends through a bore 194, which is substantially parallel to bore 176, protruding from the flat top portion 186. At the distal end of the locking lug there is provided a key portion 196. As the distal half cone 172 is slid onto axle 166, the key portion is accepted by a locking lug hole 198 provided in the flat top portion 188 of the proximal half spool 174. To lock the two half spools together, lever 192 is merely turned around the axis of the locking lug 194. To maintain the lock, a spring loaded locking means may be provided to maintain the tension on the lever 192.
FIG. 13 shows a wound netting 170 after being removed from the temporary (trash) spool 116. The netting at this point is wound in a neat bundle 170 and may be disposed of or stored. As mentioned above, the ends of the netting may be bound to form a whipping 200, and may be tagged and stored for a particular row when wound upon a reusable spool.
Conventional spools may also be mounted and secured on the levelwind system in place of the permanent spool and secured in place. The netting may be retrieved in the same manner as discussed above with regard to the permanent spool. This method provides a wound length of netting loaded onto a reusable spool which may be stored for later use. Preferably, the spool is a conventional plastic spool having a hollow core with retaining flanges with the appropriate core length and flange diameter to match the amount and type of material retrieved to the carrying capacity of the operator, i.e., 50-70 pounds. The core diameter should be large enough to snugly fit the arbor shaft mentioned above. Such spools include an Andros Engineering Agri-Spool II which may be obtained from Andros Engineering, located in San Margarita, Calif.
These reusable loaded spools may also be loaded onto the levelwind mechanism on the arbor shaft after the permanent spool has been removed and the netting may be laid out over the crops by utilizing the same retrieval head, frame, tower and sweep arrangement used for retrieving. The valving to the shaft's drive motor can be manipulated to allow the motor to freewheel and the levelwind head is disengaged. The netting is pulled off the freewheeling spool, fed into the entry end of the reversed sweep and over the row of crops, driven merely by the tension created by the anchor and crops. For dispersal, loaded reusable spools may be seated on the above mentioned cradle or just a single axle mounted on the trailer.
FIGS. 14-15 illustrate a redistribution system 208 an alternative system of spooled roll layout, wherein the reusable spools of wound netting 170 are taken from storage and reused by unrolling them onto the rows of crops 205. The system is basically the same as that of the retrieval system except that the spool of wound netting is mounted on the tower rather than the sweep. Such a system is shown in FIG. 14.
As seen in FIG. 14, the reusable spool of wound netting, or distribution spool, 210 is mounted on the boom 122 and is allowed to unroll under the tension created by the dragging over the crops and primarily from the anchored end of the netting, as discussed above. A brake 212 may also be incorporated to prevent over spinning of the spool 210 so as to provide for a smooth laying of the netting.
FIG. 15 illustrates in more detail the distribution spool 210 and its mounting to the boom 122. As is conventional, the spool 210 comprises a spool drum 220 having a conduit therethrough and two retaining flanges 222. The distribution spool 210 is mounted onto an axle 224, shown in phantom, flush with an axle housing 226 from which the axle 224 extends. The axle extends through the axle housing 226 and is coupled with a brake drum 228. The distribution spool 210 is secured on the axle 224 via a retainer means 230, such as a clamp or a pin, such as a lynch pin. The spool is connected to the boom 122 via a cross bar 132 which is affixed to the axle housing 226 at one end and the boom 122 at the other end via a slidably adjustable clamp 234. The brake 212 comprises a brake belt 236 wrapped around the brake drum 228 and a tension spring 238 secured at one end to the brake belt 236 and to an anchor post 240, which is mounted on the cross bar 232, at the other end. The tension spring 238 provides sufficient tension to prevent the spool 210 from over-spinning and releasing netting prematurely, but is loose enough to prevent tearing of the netting and damage to the crops.
For each embodiment disclosed above, a modification may be made to provide for dual retrieval or layout systems on one trailer, such that the row of crops on either side of the tractor can be covered. In the case of the layout system for bulk rolls, a two row machine may be configured such that netting may be laid on two rows of crops. In such an embodiment, the rolls would be offset to the outside of the trailer with a common center column supporting opposing outrigger arms. Netting would be applied simultaneously to the rows immediately adjacent to the left and right sides of the trailer. FIG. 16 illustrates the manner in which two booms 28,28a may be mounted on the support pole 26 to allow for mirror images of the netting laying system. The collar 250 may be drilled at a 90° angle to allow for pin 252 securement in two positions for the booms for transport and for work. A thrust collar 254 keeps the booms in position on the support pole 26 also when switching from transport to work positioning. The systems of FIGS. 9 and 14 may also be set up in mirrored configuration to retrieve and layout netting from/on two rows of crops.
It should also be known that the above mentioned spools used for retrieval, the temporary spools or the reusable spools, may incorporate, preferably somewhere on the drum area of the reusable spool or the conical portion of the temporary spool, a snag, a hole or some kind of device to pinch or anchor the leading end of the covering when initially starting the winding operation so as not to have a laborer's hands caught in the spool.
The above mentioned hydraulically controlled drives of the different embodiments may be controlled by the operator of the tractor so that he may coordinate the speed of rotation of the rolls or spools during dispersement or retrieval of the protective covering with the speed of the tractor to prevent excessive tension of slack in the covering. This usually requires the operator to periodically look back at the trailer. Alternatively, a second operator may ride along on the trailer to control the speed of the roll or spool. Such hydraulic controls are well known in the field of agricultural implements.
This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
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The present invention provides improved implements and methods for dispensing and retrieving protective crop covering materials (PCCM) onto/from rows of crops, particularly vineyard crops, to protect the plants from nuisance birds and weather conditions which cause damage to the crops. Basically, there is disclosed herein a system for layout of PCCM from a bulk roll of PCCM onto crops, a system for retrieving the PCCM from the crops and disposing it or storing said PCCM on reusable spools and a system for layout of the PCCM from the reusable spools.
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BACKGROUND
1. Technical Field
The present invention relates generally to medical imaging and, more particularly, to single photon emission computed tomographic (SPECT) imagers which detect gamma ray emissions from radionuclides administered to a patient.
2. Background Information
The field of medical imaging includes use of photon detectors commonly known as "gamma cameras" to detect, record, and display the uptake and distribution of radioactive drugs administered orally or intravenously to a patient. Signals generated by the gamma cameras are processed to provide a display of the internal distribution of the drugs in the patient or a particular target area or organ of the patient. The images are then interpreted by a specialist in radiology, cardiology or other relevant fields, in diagnosing any of a variety of medical conditions. Although stationary and planar gamma imaging have been used, a more advanced method is single photon emission computed tomography (SPECT) wherein a series of images or readings of gamma ray emissions are taken at regular angles around the patient, e.g., every 3 degrees about an axis through a target area or organ (such as the heart). The resulting images or data are processed using standard "back-projection" computer algorithms to construct one or more cross-sectional (tomographic) views of the body, target area, or organ. These images may be displayed as a single slice, a stack of slices oriented orthogonal to the axis or by other appropriate means. In the case of cardiac SPECT, the tomographic images are displayed as slices orthogonal to the long axis of the left ventricle.
SPECT has an advantage over conventional planar imaging of achieving greater contrast between normal and abnormal radioisotope uptake. In the diagnosis of coronary artery heart disease, increased image contrast is important to more clearly identify zones of the heart muscle (myocardium) which may be injured (infarcted) or may be at risk for subsequent ischemic injury.
Such conditions may warrant emergency admission to the hospital for more intensive observation or therapeutic intervention such as administration of anti-clotting drugs, cardiac catheterization or more radical surgery. Radionuclide SPECT has thus become a standard technique used in the diagnosis and prognosis of heart disease as well as disorders of the brain and other organs.
It is known that cardiac SPECT can be performed by rotating the gamma camera detector head through only 180 degrees rather than through a full 360 degrees. In this case, the imaging detector acquires data while it rotates through 180 degrees over the front of the chest. Because of the normal location of the heart, data recording begins with the detector head in the 45 degree right-anterior-oblique (RAO) position, which is slightly in front of the right shoulder, and ends in left-posterior-oblique (LPO) position, which is slightly behind the left shoulder.
Accordingly, manufacturers of commercial gamma cameras allow rotation of their detector heads either through 180 or 360 degrees. In addition, some manufacturers offer the choice of rotations that use an elliptical rather than circular path or orbit. In theory, an elliptical orbit allows the detector to travel in an orbit more closely corresponding to the elongate cross-section of the human torso. Accordingly, the imager head is closer to the patient's heart at all times, and provides better image quality. Additionally, some manufacturers offer the option of a continuous mode of data recording during rotation rather than the more usual "step-and-shoot" method of obtaining individual images at approximately 3 degree intervals through 180 or 360 degrees. The continuous mode reduces acquisition time, which may be important in studying very ill patients in an emergency setting.
As an alternative to rotating the gamma camera detector head around the patient, as used in conventional SPECT imaging, Kan et al., published a report in the Journal of Nuclear Medicine in the late 1970's in which they demonstrated that the detector could remain stationary while the patient was turned in a chair in front of the camera. This "rotating chair" method is currently embodied in a gamma camera manufactured by Picker International (formerly known as the Sinticor model SIM 400 Multi-crystal Camera). While rotating chair tomography may be useful with a reasonably healthy and cooperative patient, it is difficult with an acutely ill individual who must raise and maintain his or her left arm in a position above the chest and away from the heart. In patients confined to a bed this technique is unsuitable.
There are several gamma camera designs that utilize a single ring or multiple contiguous rings of radiation detectors. However, these imaging cameras are generally intended for brain SPECT and require that the patient lie on a bed or sit in a chair while the ring(s) completely surround the body or organ to be imaged. Therefore, complete ring detector configurations are impractical for SPECT imaging in an acute care setting. Furthermore, they are very heavy instruments and generally require permanent placement in a fixed location.
SPECT gamma cameras typically weigh several thousand pounds. Consequently, it is impractical to transport these imaging devices to desirable locations in the hospital such as the coronary care unit (CCU) or emergency room (ER) or department where care management decisions may depend on timely information concerning the patient's condition. One example is determining the state of myocardial perfusion in patients with unexplained chest pain, identifying risks of impending worsening of the disease and deciding if it is safe to send them home. Furthermore, because of their weight and gantry configuration, there are no known gamma cameras designed or capable of performing true SPECT imaging on patients who should remain in their existing beds, e.g., in the CCU or ER.
There are some mobile single head gamma cameras available that are capable of being transported to patient locations such as the CCU or ER. However, these instruments are not capable of performing true (multiple angle) SPECT. At best, they are capable only of performing a less useful technique called "limited angle" tomography. Examples include: "7-pinhole" and "rotating slant-angle collimator" tomography.
Consequently, the dominant method currently available to perform SPECT imaging on a patient in a CCU bed or in a similar emergency setting is to first transfer the patient to the location of the camera and place the patient on a special low attenuation bed that by design is an integral part of a gamma camera gantry assembly.
It is therefore advantageous that a SPECT imager and method be provided which allow imaging in a preexisting patient environment with little physical disturbance of the patient. Such a system would preferably accommodate multiple patient environments and orientations including supine patients in conventional hospital beds or seated patients.
SUMMARY
The present invention includes a SPECT imager for detecting gamma ray emissions from a patient to whom a radionuclide has been administered and generating images therefrom. The imager includes an arcuate detector carrier which encompasses at least 180° of arc about an examination axis through a target area of the patient to be examined. One or more detectors for sensing gamma ray emissions are carried by the detector carrier. The carrier is preferably of sufficiently low profile as to allow a portion of it to be inserted beneath the patient's mattress without undue movement or disturbance of the patient.
In one aspect the invention is directed to a method of imaging a patient to whom a radionuclide has been administered. A detector carrier member, carrying one or more detectors, is positioned about the patient so that the carrier member encompasses at least 180° of arc about an axis through a target area of the patient's body. A plurality of readings of gamma ray emissions from the radionuclide are taken at detection positions corresponding to positions of the one or more detectors along the carrier member. The carrier member remains substantially immobile relative to the patient while the plurality of readings are taken.
Implementations of the inventive method may include one or more of the following. All the detectors may be in a detector assembly which moves along the carrier member to take said plurality of readings. All the detectors may be positioned at different fixed locations along the carrier member. The positioning step may also comprise moving the carrier member so as to insert a portion of the carrier member beneath a mattress on which the patient rests, the patient passing through a gap between first and second ends of the carrier member. The moving step may comprise rotating the carrier member. The moving step may comprise translating the carrier member. The positioning step may comprise placing the carrier member around a head of the patient so that the axis is substantially parallel to an ear-to-ear axis of the patient. The positioning step may comprise placing the carrier member around the head of the patient so that the axis is substantially parallel to an axis extending from a nose of the patient to the back of the head of the patient.
In another aspect, the invention is directed to an imager for the study of a patient to whom a radionuclide has been administered. An arcuate detector carrier member encompasses at least 180 degrees of arc about an examination axis through a target area of the patient. One or more detectors are carried by the detector carrier member for taking a plurality of readings of gamma ray emissions from the radionuclide. The carrier member is substantially immobile relative to the patient while the plurality of readings are taken.
Implementations of the invention may include one or more of the following. The arc may be encompassed by the detector carrier member from a first end through a second end with sufficient gap to permit the relative ingress and egress of the patient through the gap. The detectors may be in a detector head moveable along the carrier member to take said plurality of readings. The detector head may be moveable along a circular arc defined by the carrier member. The detector head may be moveable along a non-circular arc defined by the carrier member, the noncircular arc corresponding more nearly to the perimeter of the patient than would a circular arc. The carrier member may have a shell, extending substantially along the length of the carrier member for preventing physical contact between the patient or the patient's environment and the detectors, while being substantially gamma transparent so as to allow the detectors to detect radiation passing through the shell. All the detectors may be positioned at different fixed locations along the carrier member. The carrier member may have first and second substantially flat portions, parallel to each other and joined by a curved portion, the detectors being substantially continuously arrayed along said flat portions and curved portion. A gantry may support the carrier member above a floor surface and be rotatably coupled to the carrier member for relative rotation about a horizontal axis orthogonal to the examination axis so as to accommodate multiple orientations of the examination axis. The gantry may include a base section for supporting the imager on a floor surface, a tower section extending upward from the base section, and an arm section coupling the tower section and the carrier member.
In another aspect, the invention is directed to an imager for the study of a patient. An arcuate detector carrier member encompasses an arc about an examination axis through a target area of the patient. One or more detectors are carried at least in part within the detector carrier member for taking a plurality of readings of gamma ray emissions. The carrier member is substantially immobile relative to the patient while the plurality of readings are taken. The detector carrier member may encompass less than 360° of arc about the examination axis. The carrier member may include a shell, extending substantially along the length of the carrier member for preventing physical contact between the patient and the detectors.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a side (axial) semi-schematic and partially cut-away view of an open ring imager according to the present invention.
FIG. 2 is a side (axial) semi-schematic and partially cut-away view of the imager of FIG. 1 shown prior to patient ingress in broken lines and after patient ingress in solid.
FIG. 3 is a side (axial) semi-schematic and partially cut-away view of an alternate open ring imager according to the present invention shown prior to patient ingress in broken lines and after patient ingress in solid.
FIG. 4 is a side (axial) semi-schematic and partially cut-away view of another alternate open ring imager according to the present invention shown prior to patient ingress in broken lines and after patient ingress in solid.
FIG. 5 is a top (axial) semi-schematic and partially cut-away view of the imager of FIG. 1, the examination axis having been rotated 90 degrees to accommodate a patient sitting in a chair.
FIG. 6 is a semi-schematic sectional view through the carrier of the imager of FIG. 1 taken orthogonally to the carrier axis along line 6--6.
FIG. 7 is a semi-schematic sectional view of an alternate carrier mechanism.
FIG. 8 is a side (axial) semi-schematic view of an open ring imager according to the present invention having a carrier of approximately elliptical section.
FIG. 9 is a side (axial) semi-schematic view of an open ring imager according to the present invention having fixed detectors and a carrier having flat top and bottom portions.
FIG. 10 is a side semi-schematic view of the imager of FIG. 1, the imager having been rotated 90° relative to the patient from the position of FIG. 1 for imaging the head of the patient.
FIG. 11 is a top semi-schematic view of the imager of FIG. 1, the examination axis having been rotated 90° and the imager rotated to image the head of the patient.
Like reference numbers and designations in the various drawings indicate like elements.
DETAILED DESCRIPTION
The following description is of the best presently contemplated modes for carrying out the invention. This description is made for 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.
As shown in FIG. 1, a patient 1 is lying in a hospital bed 10 having a mattress 12 and a supporting structure 14. The location of the patient's heart 2 is shown schematically and corresponds to a view of a supine patient from toe to head. A radionuclide drug (not shown) that preferentially concentrates in the heart is or has been administered to the patient.
A SPECT imager 20 is positioned aside the bed, adjacent the patient's left side. The imager includes a detector head 24, containing a plurality of detectors (not shown) carried by an arcuate detector carrier 26, the overall section of which is a substantially annular sector preferably of slightly greater than 180 degrees. A suitable detector head is disclosed in co-pending patent application Ser. No. 08/672,831, filed Jun. 28, 1996 now U.S. Pat. No. 5,786,597, the disclosure of which is incorporated herein by reference. The imager further includes a gantry 28 supporting the detector carrier above the floor 16. The gantry comprises a base section 30 for supporting the imager on the floor and optionally including casters 32 to facilitate movement of the imager, as well as a tower section 34 extending upward from the base and connected to a proximal end of an arm section 36, the distal end of which is connected to the carrier for holding the carrier and detector head.
As shown in FIG. 2, ingress of the patient to the imager is achieved through a gap between the upper and lower ends of the detector carrier 26. In the illustrated embodiment, the lower end 38 has a tapering contour which allows the lower portion of the carrier to be slid between the mattress and supporting structure. This may be achieved, starting with the broken line initial position, by rolling or driving the entire imager inward from the side of the bed to achieve the solid final position, or this also may be achieved via a telescoping arm 36' (FIG. 3). In addition or as an alternative to such linear translation, ingress may be achieved by a rotation of the carrier. As shown in FIG. 4, such a carrier may rotate about its central axis 100, by being driven through the distal end of the arm 36.
In the operational position, the central axis of the carrier (which defines an examination axis) is coincident with a central longitudinal axis through the patient or, more particularly, through the target organ or area of the patient's body.
As shown in FIG. 1, the detector head is movable along the carrier in a path of approximately 180° about the carrier axis. Preferably the path is slightly greater than 180° so as to provide a corresponding degree of over sampling to ensure image quality. Thus, in order to fully accommodate the detector head, the overall section of the carrier encompasses somewhat more than 180° of an arc. Initially, the detector head 24 is adjacent to the upper end of the carrier, defining a first extreme of its range of motion relative to the carrier. In the illustrated use as a cardiac SPECT imager, this is the right-anterior-oblique (RAO) position. In operation, the detector head is driven along the carrier member, taking readings either at predetermined discrete intervals, e.g., every 3°, or in a substantially continuous mode. Such operation continues until the detector head reaches a final position, shown in broken lines adjacent the lower end of the carrier and corresponding to the left-posterior-oblique (LPO) position in cardiac SPECT. Throughout this process, the carrier remains substantially immobile relative to the patient and target organ. The detector head may be driven via one or more drive motors either on the camera or the carrier. The signals from the detector head resulting from the readings of gamma ray emissions from the radionuclide as well as detector position signals from position detecting sensors (not shown) are communicated to a processing unit (not shown) where they are processed to generate images which are displayed on a conventional monitor (not shown). Egress of the patient may be achieved by simply reversing the steps involved in ingress.
As shown in FIG. 5, the carrier and examination axis may be rotated 90° about an axis orthogonal to the carrier axis (for example a longitudinal axis 104 of the arm) to perform SPECT on a patient seated upright in a chair. Rotation of less than 90° may, for example, be used if the patient is not fully upright but slightly reclined such as in a tilted bed or similar situation. To enhance image quality, the patient may place his or her inboard arm or both arms atop of the carrier (on the longitudinal edge of the carrier), which removes the arm(s) from the image and also allows the torso to be placed closer to the carrier (and thus to the detectors).
Optional methods of performing SPECT on the brain include having the imager approach the bed from the head rather than the side. With the examination axis oriented transverse to the patient's head (e.g., parallel to an ear-to-ear axis) movement of the detector head provides a view from the patient's nose to the back of the patient's head (FIG. 10). An alternative is to approach from the head of the bed with the carrier in a horizontal orientation so as to provide an ear-to-ear view (FIG. 11). In such a position, the examination axis may be parallel with a front-to-back axis of the patient's head (e.g., an axis from the nose to the back of the head).
As shown in the sectional view of FIG. 6, in one embodiment, the detector head rides between a pair of longitudinally outboard tracks 82 within the carrier. Additionally, the carrier has a shell 84 extending substantially along its length which protects the detector head and internal features of the carrier, preventing physical contact between the patient or the patient's environment (such as the bed) and the detector head. The radially inboard portion 86 of the shell is substantially gamma transparent so as to allow the detector head to detect radiation emissions from the radionuclide which must pass through the shell. To electrically couple the detector head to a processor, an annular sliding contact system 88 may be provided within the carrier member or conventional wiring or other suitable means may be used. An alternative track mechanism is shown in FIG. 7 wherein a single track 82' is located radially outboard of the detector head. This potentially provides a narrower, but thicker carrier member section than the embodiment of FIG. 6 which facilitates a low aspect ratio carrier member which is easier to insert beneath a mattress.
In the alternate embodiment of FIG. 8, the carrier 226 defines a substantially elliptical arc which corresponds more nearly to the perimeter of a patient's torso than does the circular arc.
Optional features include having the detector head be readily removable. This would facilitate both the use of a single detector head in multiple imager units (such as in the present open-ring unit and in a stationary planar imager) and the selective use of different detector heads in the single open ring imager (the detector heads being designed or tuned for different purposes such as different radiation levels, different desired image densities, or the like). In such a case, the detector head might be provided with handles which would allow it to be used as a hand-held scanner for particular purposes. With that option, electrical communication could be maintained with the processing unit by the use of extra long cabling drawn from the carrier or by separate cabling provided for such external use. Optionally a break could be made in the carrier (for example by hinging two sections of the carrier) to allow it to open yet wider to facilitate patient ingress and egress.
In yet another alternate embodiment of FIG. 9, a plurality of detectors 124 are positioned at different fixed locations along the carrier member. The resulting array of detectors extends both longitudinally and along the arc of the detector carrier and is of sufficient density to supply the desired image definition. Substantially simultaneous readings may be taken from all the detectors. The particular carrier of this embodiment is shown having upper and lower substantially flat portions 126 and 128 parallel to each other and joined by a curved portion, the detectors being substantially continuously arrayed along the flat portions and curved portions. This geometry further facilitates ingress and egress by minimizing patient disturbance when the carrier is simply translated to be inserted under the mattress. Via appropriate alignment of the detectors and programming of the processor, such noncircular and nonsimple arc profiles may be accommodated. Such profiles may also be used with a movable detector head.
Although preferred embodiments of, and/or modifications to, the present invention have been illustrated and described, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, various tracks or other structures may be utilized to define the detector path. Various detector head configurations may be utilized, including multipurpose detector heads or dedicated units. The shell may be fully or partially integrated with the track members such as in a monocoque structure. Further, the shell may be limited in scope to portions of the path of the detector requiring particular protection from contact with the environment. Further, but by no means finally, if desired, various other structures could be utilized to protect the detectors, such as a forked guide insertable under the mattress to hold the mattress elevated away from the detector path. Accordingly, other embodiments are within the scope of the following claims.
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A single photon emission computer tomography (SPECT) imager for the study of a patient to whom a radionuclide has been administered. The imager has an arcuate detector carrier encompassing at least 180° of arc about an examination axis through a target area of the patient. One or more scintillation detectors are carried by the detector carrier for taking a plurality of readings of gamma ray emissions from the radionuclide. While the plurality of readings are taken, the carrier remains substantially immobile relative to the patient.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is related to L&P 629865-2, U.S. patent application Ser. No. 14/041,667 filed Sep. 30, 2013, and U.S. Pat. No. 8,853,709, issued Oct. 7, 2014, which are incorporated herein by reference as though set forth in full.
STATEMENT REGARDING FEDERAL FUNDING
None
TECHNICAL FIELD
This disclosure relates to GaN complementary metal-oxide-semiconductor (CMOS) technology.
BACKGROUND
GaN N-channel transistors are known in the prior art to have excellent high-power and high-frequency performance. However, there are applications in which it is desirable to have a P-channel GaN transistor that can work with a GaN N-channel transistor on the same integrated circuit or substrate so that a high performance complementary metal-oxide-semiconductor (CMOS) integrated-circuit (IC) can be realized. The embodiments of the present disclosure answer these and other needs.
SUMMARY
In a first embodiment disclosed herein, a semiconductor device comprises a substrate, a III-nitride buffer layer on the substrate, an N-channel transistor comprising a III-nitride N-channel layer on one portion of the buffer layer, and a III-nitride N-barrier layer for providing electrons on top of the N-channel layer, wherein the N-barrier layer has a wider bandgap than the N-channel layer, a P-channel transistor comprising a III-nitride P-barrier layer on another portion of the buffer layer for assisting accumulation of holes, a III-nitride P-channel layer on top of the P-barrier layer, wherein the P-barrier layer has a wider bandgap than the P-channel layer, and a III-nitride cap layer doped with P-type dopants on top of the P-channel layer.
In another embodiment disclosed herein, a method for providing a semiconductor device comprises forming a III-nitride (III-N) layer buffer layer on a substrate, forming a III-N N-channel layer on the buffer layer, forming a III-N N-barrier layer on the N-channel layer, forming a first dielectric layer on top of the N-barrier layer, etching the first dielectric layer, the N-barrier layer, and the N-channel layer to form a first mesa for an N-channel transistor and to expose a portion of the buffer layer, forming a second dielectric layer over the first mesa and over a first area of the exposed portion of the buffer layer, wherein the first area is adjacent the first mesa, and wherein a remaining portion of the buffer layer is exposed, forming on top of the remaining exposed portion of the buffer layer a III-N P-barrier layer, forming on top of the III-N P-barrier layer a III-N P-channel layer, forming on top of the III-N P-channel layer a III-N P-cap layer, wherein the III-N P-barrier layer, the III-N P-channel layer, and the III-N P-cap layer form a second mesa for a P-channel transistor, and wherein the first and second mesa are separated by the first area on the buffer layer, removing the second dielectric, and implanting ions in the buffer layer between the first mesa and the second mesa for providing isolation between the N-channel transistor and the P-channel transistor.
These and other features and advantages will become further apparent from the detailed description and accompanying figures that follow. In the figures and description, numerals indicate the various features, like numerals referring to like features throughout both the drawings and the description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a cross-section of a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure; and
FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, 2J, 2K, 2L, 2M, 2N, and 2O show a process flow for fabrication a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure.
DETAILED DESCRIPTION
In the following description, numerous specific details are set forth to clearly describe various specific embodiments disclosed herein. One skilled in the art, however, will understand that the presently claimed invention may be practiced without all of the specific details discussed below. In other instances, well known features have not been described so as not to obscure the invention.
The present disclosure describes a GaN CMOS technology which integrates N-channel and P-channel GaN transistors on the same wafer. The result is a high performance GaN-based complementary metal-oxide-semiconductor (CMOS) integrated circuit. CMOS IC is the preferred topology for many circuit applications, due to its high noise immunity and low power consumption.
L&P 629856-2, which is incorporated by reference, describes a P-channel transistor. The GaN ICs of the present disclosure integrate N-channel and P-channel transistors on a common substrate and have better performance than a circuit with discrete GaN N-channel and/or P-channel transistors because more functionality can be achieved with less power consumption. An advantage of the GaN ICs of the present disclosure is that their performance is better than what can be attained with Si CMOS, because high performance N-channel and P-channel GaN transistors are used.
FIG. 1 shows a cross-section of a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure. The substrate 10 can be GaN, AlN, Sapphire, SiC, Si or any other suitable substrate material. FIG. 1 is further described below with reference to FIG. 2O .
FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, 2J, 2K, 2L, 2M, 2N, and 2O show a process flow for fabrication a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors in accordance with the present disclosure. FIG. 2O is the same as FIG. 1 , but is also shown in the process flow for completeness.
Referring now to FIG. 2A , a III-N layer buffer layer 12 is on the substrate 10 , and may be grown by chemical vapor deposition (MOCVD) or molecular beam epitaxy (MBE). The buffer layer 12 may be GaN. On top of the buffer layer 12 is III-N N-channel layer 14 , which may be GaN, and which may be grown by MOCVD or MBE. On top of the III-N N-channel layer 14 is a III-N N-barrier layer 16 , which may be grown by MOCVD or MBE. The barrier layer 16 can be AlGaN, AlInN, AlInGaN, AlN, or a combination of these layers. The barrier layer 16 has a wider bandgap than the N-channel layer 14 , and the thickness of the barrier layer 16 is typically in the range of 1˜100 nm.
A layer of dielectric 18 is deposited on top of the N-barrier layer 16 . The dielectric 18 may be SiN, SiO 2 , SiON, AlN, or any combination of those, and may have a thickness of 1˜500 nm.
Next with reference to FIG. 2B , the dielectric 18 , the barrier layer 16 , and the channel layer 14 are etched to create a mesa 52 of the channel layer 14 , the barrier layer 16 and the dielectric 18 and to expose a portion of the buffer layer 12 .
Then as shown in FIG. 2C , a dielectric 60 is formed over the mesa 52 and over an area 54 of the exposed portion of the buffer layer 12 .
Next with reference to FIG. 2D , on top of the remaining portion 56 of the buffer layer 12 , a III-N P-barrier layer 20 may be grown by MOCVD or MBE. The P-barrier layer 20 can be AlGaN, AlInN, AlInGaN, AlN, or a combination of these. The thickness of the P-barrier layer 20 is typically in the range of 1˜100 nm. The P-barrier layer 20 assists in the accumulation of holes. On top of the III-N P-barrier layer 20 , a III-N P-channel layer 22 may be grown by MOCVD or MBE. The P-channel layer 22 is typically GaN, with a narrower bandgap than the P-barrier layer 20 . The thickness of the P-channel layer 22 is typically in the range of 1˜100 nm.
On top of the III-N P-channel layer 22 , a III-N P-cap layer 24 may be grown by MOCVD or MBE. The III-N P-cap layer 24 is typically GaN doped with Mg. The Mg concentration can vary across the P-cap layer 24 . The thickness of the P-cap layer 24 is typically 1˜100 nm.
Then, as shown in FIG. 2E , the dielectric 60 , which masked the mesa 52 and the area 54 of the buffer layer 12 while forming the P-barrier layer, the P-channel layer, and the P-cap layer, is removed. The result, as shown in FIG. 2E is the mesa 52 for an N-channel transistor, and a mesa 58 for a P-channel transistor.
Next, as shown in FIG. 2F , the mesa 52 may be isolated from the mesa 58 by ion implantation 50 in the area 54 and on the sides of mesas 52 and 58 .
Then, as shown in FIG. 2G , a dielectric 26 is deposited over the P-cap layer 24 of mesa 58 , and over a portion of area 54 between the mesa 52 and the mesa 58 .
Next, as shown in FIG. 2H , a P-gate trench 62 is formed in dielectric 26 . The bottom of the P-gate trench 62 may extend partially or entirely through the P-cap layer 24 , and may also extend partially through the P-channel layer 22 .
Then, as shown in FIG. 2I , a N-gate trench 64 is formed in dielectric 18 . The bottom of the trench 64 may extend partially or entirely through the dielectric 18 , partially or entirely through the barrier layer 16 , and partially or entirely through the N-channel layer 14 , so that the N-gate trench stops anywhere between the top surface of dielectric 18 and the top surface of the buffer layer 12 .
Next, as shown in FIG. 2J , a dielectric 28 is formed over the device, so that the dielectric 28 is on top of dielectric 18 , covering the bottom and sides of N-gate trench 64 , on top of dielectric 26 , and covering the bottom and sides of P-gate trench 62 . The dielectric 28 is typically a stack of AlN/SiN layer, grown by MOCVD. The dielectric 28 may also be only deposited in the N-gate trench 64 and the P-gate trench 62 to insulate the N-gate electrode 32 and the P-gate electrode 42 , respectively, for low gate leakage current.
Then, as shown in FIG. 2K , N-ohmic openings 70 and 72 are made on opposite sides of the N-gate trench 64 . The openings 70 and 72 are made through the dielectric 28 , and may be made partially or entirely through the dielectric 18 , and in some cases partially or entirely through the N-barrier layer 16 .
Next, as shown in FIG. 2L , the openings 70 and 72 are filled with metal to form N-ohmic electrodes 74 and 76 , forming source and drain contacts, respectively, for the N-channel transistor.
Then, as shown in FIG. 2M , P-ohmic openings 80 and 82 are formed on opposite sides of the P-gate trench 62 . The openings 80 and 82 are made through the dielectric 28 , through the dielectric 26 , and in some cases partially or entirely through the P-cap layer 24 .
Next, as shown in FIG. 2N , the openings 80 and 82 are filled with metal to form P-ohmic electrodes 84 and 86 , forming source and drain contacts, respectively, for the P-channel transistor.
Finally, as shown in FIG. 2O , the N-gate trench 64 is filled with metal 32 to form a gate contact for the N-channel transistor, and the P-gate trench 62 is filled with metal 42 to form a gate contact for the P-channel transistor.
The result is a GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit with N-channel and P-channel transistors, as shown in FIG. 1 , which is the same as FIG. 2O .
Referring now to FIG. 1 , the substrate 10 may be but is not limited to GaN, AlN, Sapphire, SiC, or Si. The III-N buffer layer 12 is on the substrate 10 . As shown in FIG. 1 , on top of one portion of the buffer layer 12 , is the III-N N-channel layer 14 on the buffer layer 12 , and the III-N N-barrier layer 16 on the N-channel layer 14 . On top of another portion of the buffer layer 12 , is the III-N P-barrier layer 20 on the buffer layer 12 , the III-N P-channel layer 22 on the P-barrier layer 20 , and the III-N P-Cap layer 24 on the P-channel layer 22 .
The dielectric 28 covers the bottom and sides of N-gate trench 64 , and the bottom and sides of P-gate trench 62 , as described above. Metal 32 fills gate trench 64 to form a gate contact for the N-channel transistor, and metal 42 fills gate trench 62 to form a gate contact for the P-channel transistor.
N-ohmic electrodes 74 and 76 provide source and drain contacts, respectively, for the N-channel transistor, and P-ohmic electrodes 84 and 86 provide source and drain contacts, respectively, for the P-channel transistor.
Ion implantation 50 in the area 54 between the N-channel transistor and the P-channel transistor provides isolation of the N-channel transistor from the P-channel transistor.
A person skilled in the art will understand that the order of the steps of the process flow of FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, 2J, 2K, 2L, 2M, 2N, and 2O may be in another order to achieve the GaN based complementary metal-oxide-semiconductor (CMOS) integrated circuit shown in FIG. 1 . A person skilled in the art will also understand that well known steps of patterning and etching may be used in the process flow, such as for example to remove a layer or portion of a layer. Such well known processes are not described in detail, because they are widely used in semiconductor processing.
Having now described the invention in accordance with the requirements of the patent statutes, those skilled in this art will understand how to make changes and modifications to the present invention to meet their specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention as disclosed herein.
The foregoing Detailed Description of exemplary and preferred embodiments is presented for purposes of illustration and disclosure in accordance with the requirements of the law. It is not intended to be exhaustive nor to limit the invention to the precise form(s) described, but only to enable others skilled in the art to understand how the invention may be suited for a particular use or implementation. The possibility of modifications and variations will be apparent to practitioners skilled in the art. No limitation is intended by the description of exemplary embodiments which may have included tolerances, feature dimensions, specific operating conditions, engineering specifications, or the like, and which may vary between implementations or with changes to the state of the art, and no limitation should be implied therefrom. Applicant has made this disclosure with respect to the current state of the art, but also contemplates advancements and that adaptations in the future may take into consideration of those advancements, namely in accordance with the then current state of the art. It is intended that the scope of the invention be defined by the Claims as written and equivalents as applicable. Reference to a claim element in the singular is not intended to mean “one and only one” unless explicitly so stated. Moreover, no element, component, nor method or process step in this disclosure is intended to be dedicated to the public regardless of whether the element, component, or step is explicitly recited in the Claims. No claim element herein is to be construed under the provisions of 35 U.S.C. Sec. 112, sixth paragraph, unless the element is expressly recited using the phrase “means for . . . ” and no method or process step herein is to be construed under those provisions unless the step, or steps, are expressly recited using the phrase “comprising the step(s) of . . . .”
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A semiconductor device includes a substrate, a III-nitride buffer layer on the substrate, an N-channel transistor including a III-nitride N-channel layer on one portion of the buffer layer, and a III-nitride N-barrier layer for providing electrons on top of the N-channel layer, wherein the N-barrier layer has a wider bandgap than the N-channel layer, a P-channel transistor including a III-nitride P-barrier layer on another portion of the buffer layer for assisting accumulation of holes, a III-nitride P-channel layer on top of the P-barrier layer, wherein the P-barrier layer has a wider bandgap than the P-channel layer, and a III-nitride cap layer doped with P-type dopants on top of the P-channel layer.
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The present invention relates to a microbial pest control agent active against Venturia inaequalis.
BACKGROUND OF THE INVENTION
After years of research and treatment, apple scab, caused by Venturia inaequalis (CKE.) Wint., is economically the worst disease of apple trees (Malus domesticus L.) worldwide (Agrios, 1988). Much research has been devoted to the control of primary infections, and it has yielded very costly and ecologically questionable spraying schedules (Funt, 1990). These sprays represent an appreciable cost to growers and can have a substantial indirect impact on the environment. Development of fungicide resistance in the pathogen population is also threatening apple production. Thus it is essential to develop an ecologically and environmentally friendly alternative control strategy for apple scab.
In cold temperature regions, the fungal pathogen V. inaequalis overwinters as a saprophyte and to a significant extent only as incipient pseudothecia (sexual structures) in fallen apple leaves on the orchard floor. Pseudothecia, initiated during fall or winter, mature in the spring to produce ascospores which serve as primary inoculum for the initial infections (Ellis 1990). Thus, the overwintering stage is one weak link in the life cycle of the fungus. If the pathogen could be killed or seriously weakened in the leaf litter, the primary inoculum available in the spring would be substantially reduced.
Ascospore discharged from leaves are dispersed by wind to expanding floral primordia and unfolding leaves. Floral, leaf, and fruit tissues are much more susceptible when young than when mature. Early infection, particularly of floral structures, by primary inoculum (ascospores) is thus extremely significant in the epidemiology of this disease because the fungus becomes established in a favourable location for secondary infection of the developing fruit and leaves. The critical time for the development of apple scab is from the opening of fruit buds until petal fall. If the disease can be suppressed during this time, its later management is usually easier. Thus, this period is the second key stage in the life cycle for the disease control.
After the host penetrates, a fungal stoma eventually develops between the cuticle and the outer walls of the epidermal cells. This stroma produces conidiophores which rupture the host cuticle. Conidia borne from these conidiophores are dispersed by the movement of wind and rain to susceptible leaves and fruit where secondary infection occurs. This secondary infection repeats itself until leaf fall in the autumn. When the pathogen, V. inaequalis, infects developing fruit, it causes corky lesions and deformations, reducing yields and making fruit unmarketable. The overwintering saprophytic stage is then re-initiated.
Early attempts to use urea to reduce the primary inoculum of V. inaequalis was reported in the 1960's (Cook, 1969). Since then a lot of attention was focused on safe methods for the reduction of the primary inoculum and less attention was devoted to methods which employed dangerous chemicals such as DNOC and lead arsenate. Cultural methods aimed at destroying the leaves such as mulching and tilling were also successfully used in the past.
Certain organisms, mainly fungal isolates, when applied in autumn on fallen leaves will inhibit pseudothecial formation and thus reduce ascospore production in the following spring. Heye (1982) found a fungus, Athelia bombacina, which completely inhibited the formation of pseudothecia on sterile discs (Heye and Andrews, 1983). This antagonist was also tested under field conditions. However, results are incomplete since it was not evaluated during the whole ascospore ejection season (Miedtke and Kennel, 1990).
Thus, there is a need for a biological control agent against V. inaequalis, which can be used on a commercial scale.
SUMMARY OF THE INVENTION
The present invention relates to a microbial pest control agent active against Venturia inaequalis. More specifically the present invention is directed to a microbial pest control agent of the genus Microsphaeropsis.
In one embodiment of the present invention there is provided an substantially pure isolate of a species of the genus Microsphaeropsis, which is effective in controlling apple scab caused by V. inaequalis.
In a further embodiment of the present invention there is provided a method of controlling apple scab caused by V. inaequalis comprising applying an effective amount of an isolate of a species of the genus Microsphaeropsis.
The present invention also provides a method of purifying an extract from the isolate of a species of the genus Microsphaeropsis, which is effective in controlling apple scab caused by V. inaequalis.
A further embodiment of the present invention is directed to a substantially purified extract from an isolate of a species of the genus Microsphaeropsis, which is effective in controlling apple scab caused by V. inaequalis.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings wherein:
FIG. 1: The effect of different fungal isolates on the ascospore production of V. inaequalis; inoculation of V. inaequalis with mycelium (the "M" experiment in Example 1).
FIG. 2: The effect of different fungal isolates on the ascospore production of V. inaequalis; inoculation of V. inaequalis with conidia (the "C" experiment in Example 2).
FIG. 3: Wooden cages used for ascospore monitoring.
FIG. 4: Effect of fungal isolates on ascospore production on naturally infected apple leaves under orchard conditions.
FIG. 5: Effect of fungal isolates on ascospore production on artificially infected apple leaves under orchard conditions.
DESCRIPTION OF PREFERRED EMBODIMENT
The present invention relates to a microbial pest control agent active against Venturia inaequalis. More specifically the present invention is directed to a microbial pest control agent of the genus Microsphaeropsis.
Samples of natural fungal microflora were collected from an abandoned apple orchard. Dead leaves were collected from the ground after snow melt and the leaves were placed in appropriate growth media to encourage the growth of any natural fungal microflora occurring on the leaves. A number of isolates were collected and tested for their ability to degrade apple leaf tissue, inhibit pseudothecia or ascospore production of V. inaequalis. As mentioned above, if pseudothecia or ascospore production of V. inaequalis could be reduced then the present reliance on chemical spays could also be reduced.
In the present invention six samples: P176A, P130A, P11A, P164A, P138A and P10A significantly reduced ascospore production of V. inaequalis with conidia. Three isolates P176A, P130A and P11A significantly reduced ascospore production of V. inaequalis with mycelium. The first three isolates were common to both sets.
In one embodiment of this present invention two of the possible isolates, based on morphological characteristics, have been determined to belong to the genus Microsphaeropsis. Suitable isolates, which have been identified according to the present invention include, but are not limited to, isolates identified as P130A and P176A. In one embodiment of the present invention isolates P130A and P176A were consistently in the top ten in tests to determine leaf rheology, ascospore and pseudothecia reduction. One isolate of the present invention P130A has been deposited with the American Type Culture Collection on May 23, 1997 under Assession Number 74412.
One aspect of the present invention involves a method of controlling and or reducing the incidence of V. inaequalis infestation and thus reducing the amount of chemical spraying of the apple orchard. In this aspect of the invention a suitable amount of the microbial pest control agent comprising a single isolate is applied after harvest to inhibit the formation of pseudothecia and ascospore of V. inaequalis, and consequently reduce the amount of primary inoculum the following spring. Thus according to this aspect of the invention the microbial pest control agent comprises one isolate identified as P130A.
The isolates of the present invention can be used along or together with suitable carriers. Any aqueous material that does not adversely effect the effectiveness of the isolate could be mixed with the isolate and used as the microbial pest control agent. Any effective amount of the microbial pest control agent can be used. The most effective amount can be determined empirically by persons skilled in the art. Examples of effective amounts can range from 2×10 5 to 6×10 5 conidia per ml. The suspension of conidia can be applied at a dose of from about 1000L/ha to about 1500L/ha or from about 1L per tree to about 1.5L per tree. The invention is of course not limited to these specific examples, as persons skilled in the art could make appropriate amendments are required.
In a further embodiment of the present invention, the active fraction from the isolate is partially purified. In this aspect of the invention the isolate was grown in a liquid medium and the broth collected after an appropriate growth period. The liquid media was subjected to a solvent extraction, to obtain a solvent extract. The solvent extract was then dried and resuspended in a small volume of solvent. In one example of the present invention chloroform is used to obtain the solvent extract. The dried solvent extract can be resuspended in methanol or chloroform for example. According to this aspect of the invention two active fractions were identified, one with an approximate R f value of 0.65 and one with approximate R f value of 0.95.
In a further embodiment of the present invention the solvent extract can be further purified by silicic acid column chromatography. The solvent extract, in one example the chloroform extract, was applied to a column of silica gel silicic acid and eluted with steps of increasing concentration of methanol in chloroform. From such a column four fraction were identified. Of these four fractions only one, FII, showed strong antifungal activity.
In yet a further embodiment of the present invention the active fraction (FII), purified from the silica gel column as described above can be further purified by preparative thin layer chromatography. A number of fractions were identified, of which fractions F-II2 and FII3a were found to have antifungal activity.
Thus the present invention is also directed to any one of these partially purified extracts of the isolates of the present invention. One or more of these partially purified extract can be used alone or together with one or more extracts, any of which can be added to any acceptable carrier prior to use.
Thus according to the present invention, any one of these partially purified fractions from the isolates of the present invention could be used to inhibit the formation of pseudothecia and ascospore of V. inaequalis. As with the isolates, the partially purified fractions would be applied after harvest to inhibit the formation of pseudothecia and ascospore of V. inaequalis in the following spring.
While this invention is described in detail with particular reference to preferred embodiments thereof, said embodiments are offered to illustrate but not to limit the invention.
EXAMPLES
Example 1
Isolation and Characterization of the Microbial Pest Control Agent
Sampling was done in an apple (Malus pumila Mill var McIntosh) orchard, which had been abandoned for more than five years, to ensure that no fungicide treatment or residues would affected the natural fungal microflora. Dead apple leaves lying on the ground were collected for a three day period after snow melt. Arbitrarily chosen leaves were placed in glass petri plates of 9 cm diameter containing a sheet of Whatman filter paper saturated with distilled water. The petri plates were incubated at -2° C. for two to three weeks, four plates per temperature. The leaves were observed under a dissecting microscope and each mass of spores, fruiting bodies or mycelia was picked up and placed on half-strength V8 agar media amended with 100 μg/ml of chlorotetracycline and 200 μg/ml of streptomycin. The isolate was transferred to V8 medium (Calcium carbonate, 3 g; bacto agar, 15 g; V-8 juice, 100 ml; and distilled H 2 O; 900 ml).
Resulting colonies were cream color, with a cottony aspect, on both sides of the colonies. Growth was relatively slow on V-8 agar (5 cm in 14 days) and the color of the media turned brown. The isolate produced dark brown to black pycnidia on different agar media after a few weeks, and after 10 days when inoculated on apple leaves or in soil. Droplets of black liquid containing conidia may ooze out by the pycnidia ostiole. A description of the isolate was as follows:
Mycelium: brown, septate, branched
Conidiomata: pycnidia partially superficial, black, globose, ostiolate
Ostiol: simple, circular
Conidiophore: absent
Conidiogenous cells: Enteroblastic, phialidic
Conidia: pale brown, aseptate, smooth and thin-walled, guttulate, no appendices, cylindrical to elliptical (4-6 μ×2-4 μ)
As a result of this description the isolate (P130A) was determined to belong to the genus Microsphaeropsis. As previously discussed, this strain has been deposited with the American Type Culture Collection on May 23, 1997, under ATCC designation number 74412.
When comparing conidia of P130A with those of other Microsphaeropsis, the only species which has similar conidia based on conidia size is M. arundinis. None of the other Microsphaeropsis (M. olivaceae, M concentrica, M. centaurae) bear such small conidia. However, final species identification is not yet complete.
The optimal temperature for growth is 25° C. and the optimal pH for growth is 5.0. There was no marked difference in growth among different media (V-8, PDA (Potato Dextrose Agar) or PDB (Potato Dextrose Broth), Czapek agar or broth, MEA (Malt Extract Agar); PDA, PDB, Czapek and MEA available from either Difco or BBL). The isolate is sensitive to Captan, Mancozeb and Metiram, but is relatively resistant to Myclobutanyl.
Example 2
In vitro Screening
A collection of forty-two fungal isolates were tested for their in vitro ability to degrade apple leaf tissue, inhibit pseudothecia, and ascospore production. Ascospore production was retained as the most useful screening parameter. Six isolates (P176A, P130A, P11A, P164A, P138A and P10A) proved to significantly reduce the ascospore production of Venturia inaequalis. Two isolates (P130A and P176A) were as effective as Athelia bombacina, a previously reported antagonist of pseudothecia formation and inhibited over 98% of the ascospore production under in vitro conditions.
Leaf disks were cut from non infected apple leaves (cv McIntosh). The leaf disks were sterilized by irradiation (10 hr, 40 kGy of gamma radiation). Glass jars (500) were filled with 100 ml of Perlite™ and 50 ml of distilled water and were then autoclaved for 15 minutes at 121° C. The leaf disks were placed in them under sterile conditions, abaxial surface up, at a rate of 4 disks per jar. The jars were used as sampling units.
The conidia of V. inaequalis, (5 isolates), were produced with very slight modifications of previously published methods (Keitt and Palmiter, 1938; Williams, 1976). A mycelial suspension of V. inaequalis was made from one-month-old cultures grown on PDA (7 isolates). Each disk received 50 μL of the conidial (C) or mycelial (M) suspension and were incubated at room temperature in full darkness for approximately two weeks.
The fungal isolates were grown on V8 agar for two weeks. One month after the inoculation with V. inaequalis, a mycelial suspension of each fungal isolate was made and applied directly on the leaf disks (50 μL/disk) of 5 jars. Two uninoculated controls per block were used: sterile disks and V. inaequalis inoculated alone. The jars were kept at 25° C. in full darkness for one week to favor antagonist colonization, incubated at 4° C. for a month and then were transferred to 10° C. for an extra 3 months. An isolate of A. bombacina found antagonistic in Heye's study (1982) was included as a positive control.
The maximum rupture force (N), per leaf thickness (mm) was recorded for each disk using a Instron® penetrometer using a 50-Newton cell with crosshead speed set at 100 mm/min. All disks were recovered for the following tests.
The ascospore production was measured after a simulated winter. Three different readings at weekly intervals were taken to observe any possible lag in spore maturation. The results of the three extractions are reported for each treatment as the total ascospore production per cm 2 .
The two remaining disks of each jar were cleared by autoclaving them in glass petri dishes with approximately 25 ml of a KOH solution 0.4M (20 g/L). After careful decantation of the caustic solution, a few drops of lactophenol were added to each disk. The pseudothecia were counted under a binocular at a low magnification, and expressed as the number of pseudothecia per square centimetre.
The V. inaequalis control significantly affected leaf rheology as compared to the sterile disk, consequently it served as the reference for the other treatments. Aside from the positive control (A. bombacina), a total of ten isolates in the C and twenty-one in the M experiment significantly reduced the leaf strength in vitro at the 95% confidence level. Of these, five of the six best were common to both inoculation methods. Except for the difference between the sterile control and all the treatments, the leaf strengths showed no obvious groupings and varied smoothly with the different treatments. The nine best treatments in the M experiment were not statistically different from one another, and similarly for the nineteen best treatments of the C method.
Aside from the control, three isolates (P130A, P176A and P11A) significantly reduced the ascospore production in the C experiment while six isolates (P176A, P130A, P11A, P164A, P138A and P10A) did the same in the M experiment (FIG. 1 and FIG. 2). The three first isolates are common to both sets. Treatment with P130A is reported by both methods to be as efficient as A. bombacina, while P176A is rated similarly only in the M experiment. More than 98% of the ascospore production (>1.84 log reduction) was inhibited by the fungi classed alongside A. bombacina.
In the C experiment, 5 isolates (P130A, P11A, P176A, P10A, and 306) aside from the positive control (AB) significantly reduced the pseudothecial production and the efficiency of the first three was not significantly different from A. bombacina. A total of nine isolates significantly reduced pseudothecial production.
Example 3
Field Testing
Among our collection of fungal isolates, an isolate of Microsphaeropsis spp. has shown the ability to inhibit ascospore production under controlled conditions (in vitro test). In order to estimate the real potential of this antagonist as well as others, tests were conducted under natural condition. The objective of this study was to test the efficacy of fungal isolates in reducing ascospore potential under orchard conditions.
All assays in the field were done at Frelighsburg (Quebec) experimental farm of Agriculture Canada. In the beginning of October, apple leaves (Malus pumila Mill. "McIntosh") naturally infected with V. inaequalis were collected on the trees. This apple variety was chosen for its susceptibility to infections of V. inaequalis (Cke.) Wint. The trees had not been sprayed with fungicides and leaves showed severe apple scab symptoms. The leaves were carefully examined and leaves without evident scab lesions were discarded. The leaves were stored at 2° C. in bags until processed. Infected leaves not treated with the fungal isolate were used as control.
The number of ascospores on lesions from naturally infected leaves is extremely variable (0 to more than 2,000 ascospores). This makes the analysis and interpretation of the results difficult. Since increasing the number of leaves sampled would not be possible because of the time required to count the ascospores it was decided to add a test with artificially inoculated apple leaves. Since this method have previously shown to produce more uniform results. Leaf disks were cut in non infected apple leaves collected randomly from McIntosh trees using a stainless steel cork borer of 2.7 cm in diameter (or 5,73 cm 2 ) and sterilized in a glass jar by irradiation (10 hours exposition at 40 kGy (4Mrad) of gamma radiation). Sterile leaf disks were placed in glass jars (4 per jar), filled with 100 ml of Perlite and 50 ml of distilled water and then autoclaved for 15 minutes at 121° C. After cooling of the jars, the leaf disks were placed in jars under sterile conditions, abaxial surface up. A mycelial suspension of Venturia inaequalis was made from a 1 :1 :1 :1 :1 mixture of cultures originating from 5 different isolates of known sexual compatibility and 50 μl of the mycelial suspension was inoculated on the disks surfaces. The disks were then incubated at room temperature in full darkness for approximately two weeks prior to antagonist inoculation.
The antagonist was grown on potato-dextrose agar at 20° C. until the fungi covered more than approximately half the surface of a 9-cm Petri-dish. They were then stored at 2° C. until the day of application on the leaves or leaf disks. On the day of application, 25 Petri-dishes were cut and inserted in a sterile plastic bag along with 300 mL of distilled water. The bag contents were homogenized in a Stomacher for 480 seconds at normal speed or longer until the same homogeneity was obtained. The bag contents were then transferred to a beaker of 2 L capacity and the volume was adjusted to 1.5 L with distilled non sterile water. Each treatment consisted of applying 500 mL of this preparation to 450 scabbed leaves. The leaf disks artificially inoculated with V. inaequalis received 50 μL of a mycelial suspension of the antagonist. After an incubation of two weeks at room temperature leaf disks were placed on the orchard floor.
Each sample of treated leaves or leaf disks were over-wintered under screen cages so that leaves were exposed to natural weather conditions. The cages were installed in the orchard in a randomized complete block design and fastened to the ground with wire pegs. The blocks represented different locations in the orchard. Leaf cages remained in the orchard until the end of the ascospore ejection period the following spring.
The ascospore production for each treatment was evaluated during the whole ascospore ejection periods, from late April to early July. Three leaves per treatment, randomly chosen, were installed on the bottom of a wooden spore trap (Coulombe 1976); FIG. 3, the ventral face upward. At 0.5 cm above the leaves, microscopic slides, previously coated with petroleum jelly, were installed. After each period of rain, all the microscopic slides were removed and immediately replaced with new ones. These microscopic slides were stored at 0° C. until examination. The number of ascospores present on 40% of the slide surface were counted.
The isolates labelled P130A reduced the ascospore production by 87% (FIG. 4). The cumulative number of ascospores trapped followed a typical pattern. Looking at each rain event, we observed only three periods with moderate ascospore production as opposed to six in the control.
Because of the inherent variation in ascospore numbers produced on naturally infected leaves, other tests were conducted on artificially inoculated leaves. Half of these leaves were incubated in vitro and the other half in the orchard. The amount of ascospores produced on these leaves was measured only once since mature ascospores accumulated in the pseudothecia in the absence of rain (Philion, 1995). For the isolate P130A, we observed 96 and 95% ascospore inhibition on leaves incubated in vitro and on those placed in the orchard for the whole winter, respectively (FIG. 5). Thus, if we compare the two tests, natural vs artificial infection of leaves with V. inaequalis, we can note that in all artificial inoculations including experiments done earlier (Philion, 1995) the ascospore inhibition when leaves are treated with the isolate P130A varies from 95 to 98%. However, when leaves are naturally infected with V. inaequalis and maintained under orchard conditions the inhibition is reduced to about 87%. One possible explanation would be that the mycoparasitism activity of the antagonist which implies an intimate contact between the antagonist and the pathogen is favored in artificial inoculations. Natural microbial competition present on leaves naturally infected with V. inaequalis may also explain the difference in efficiency since this competition is absent on leaves artificially inoculated.
Example 4
Mode of Action of the Microbial Pest Control Agent
The purpose of the work described here was to determine the mode of action of Microsphaeropsis sp. in its antagonism against V. inaequalis and other potential pathogens. To this end, two aspects of the interaction between Microsphaeropsis sp. and its host was studied: cytological and cytochemical investigation of the interaction and biological activity of extracellular metabolites produced by Microsphaeropsis sp.
Cytological aspect of the interaction between Microsphaeropsis sp. and its host Microsphaeropsis sp., Pythium ultimum, Botrytis cinerea, Rhizoctonia solani, were kept at room temperature on Potato dextrose agar medium (PDA), while Venturia inaequalis, was kept at 15° C. on PDA.
Sterile microscopic glass slides (2.5×7.5 cm) were immersed in four time dilute PDA. The next day, discs (5 mm) cut with cork borer from the leading edge of colonies were deposited 3.5 cm apart on slides. Two Petri dishes for each dual culture were incubated for at least 5 days at room temperature. Interactions between the opposing colonies were visualized progressively under reversed light microscopy. Because V. inaequalis is a slow grower, Pythium ultimum, Botrytis cinerea, Rhizoctonia solani were chosen for preliminary experiments.
In tip-to-host side interactions, the antagonist tips continued to grow after contact; they grew over or along the host hyphae depending on the angle of the contact. A few hours after contact, vacuolation or coagulation of B. cinerea and P. ultimum hyphae occurred. In some instances, lysis occurred in P. ultimum by violent discharge from a narrow region where host and antagonist have first made contact. In B. cinerea, the development of intracellular hyphae of Microsphaeropsis sp. was observed.
Antifungal activity of extracellular metabolites produced by Microsphaeropsis sp.
Microsphaeropsis sp., Cladosporium cucumerinum, Botrytis cinerea were both kept at room temperature on Potato dextrose agar medium (PDA), while Venturia inaequalis, was kept at 15° C. on PDA.
One liter of malt extract liquid medium was poured into two 1-L Erlenmeyer flask. The medium was inoculated with ten discs of Microsphaeropsis sp. grown on solid medium (7-mm diameter) punched out from the edge of a 7-day-old colony grown on PDA. The fungus grew at 26° C. for different periods of time (5, 10, 15, 20, 25, and 30 days), with agitation at 175 rpm. At the end of the incubation period, the mycelium was collected, dried to a constant weight in a ventilated oven at 100° C., and weighed. The pH values of the liquid culture were measured during the course of the experiment.
After discarding the mycelium, the liquid media was extracted three times with one volume of chloroform for one volume of culture filtrate. The chloroform extract was dried under vacuum, with a 40° C. water bath and a rotary evaporator, then was redissolved in chloroform. Chloroform extracts were transferred to 4 ml vials, dried under nitrogen stream and weighed. The dried extracts were resuspended in a known volume of chloroform or methanol.
The screening of molecules with antifungal activity was performed with thin layer chromatography (TLC). TLC was carried out for analytical purpose with silica gel plates (Merck 60 F 254 , 0.2-mm thick). Chloroform extracts were deposited as spots of 50 μl after drying, the chromatograms were developed in an appropriate solvent mixture. The spots were viewed under ultraviolet radiation at 254 and 366 nm. To localize zones with antifungal activity, silica gel plates were seeded with a sporal suspension of Cladosporium cucumerinum. Because of the dark pigmentation of spores and mycelium of this fungus, zones of antifingal activity could be readily identified as white spots. Spraying of sporal suspension of C. cucumerinum minimally revealed two major active spots in the chloroform extract with an approximately R f value of 0.65 and 0.95.
For a large scale purification, chloroform extracts were purified by silicic acid column chromatography. The extracts were applied to a column (2×37 cm) filled with silica gel silicic acid (Silica Gel; 60-230 mesh, Baker Analyzed reagent) and flash-chromatographed by successive elutions with steps of increasing concentration of methanol in chloroform: 0, 2.5, 5, 10, 30, 50, 100%. For each eluted fraction, assessment of antifungal activity was carried out with the TLC bioassay as described above. Different products were found in different mixtures of chloroform/methanol. Fractions containing the same products, as determined by TLC plate, were pooled for further analysis. The active fraction was designated F-II.
The fraction F-II was further purified by preparative thin layer chromatography silica gel 60 F 254 0.5 mm (Merck). The chloroform fraction FII was deposed on the plate (20×20 cm), which was developed using the solvent system CH 3 Cl:AcEt (1:1; v/v). The fractions F-II1; F-II2; F-II3a and F-II4a were extracted from silicic acid with chloroform and the fractions F-II3b; F-II4b were extracted with methanol. Thin layer bio-assay revealed the antifungal activity in F-II2 (R f =0.46) and F-II3a (R f =0.34).
Aliquots of the semi-purified chloroformic extract (Fraction F-II3a) were added to 10-ml vials and dried by sterilized air to remove the solvent. The residue was weighed, and the vials were filled with 2 ml of potato dextrose broth (PDB) and inoculated with 7-mm disc of B. cinerea or V. inaequalis. Antifungal activities were determined by weighing the colonies as described above.
Growth of the fungus, pH of the medium, and antiflngal activity of the culture filtrates were determined for 30 days of culture. During the growth period, the pH value stayed relatively stable. The antifungal activity was detectable after 15 days, and reached a maximum after 20 days of culture under our standard conditions. On silica gel thin layer chromatograms, chloroform extracts were separated into several spots as visualized under ultraviolet radiation at 254 and 366 mm and by cerric sulfate ammonium molybdate reagent.
Example 5
Field Trials
The biological control agent in a suspension of 4.5×10 5 conidia per ml was applied at a rate of 1125 L/ha or 1.2 L per tree. The suspension was applied using conventional orchard sprayers.
The suspension was applied in one of two methods, either after apple harvest but before leaf fall or in two applications on the ground at about 60% and 90% leaf fall.
All scientific publications and patent documents are incorporated herein by reference.
The present invention has been described with regard to preferred embodiments. However, it will be obvious to persons skilled in the art that a number of variations and modifications can be made without departing from the scope of the invention as described in the following claims.
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Apple scab, caused by the fungal pathogen Venturia inaequalis, is considered to be the most important single disease of apple worldwide and one of the most costly to control. Currently, the strategy for apple scab control relies on multiple applications of fungicides, often 8 to 12 fungicide sprays each growing season. These sprays represent an appreciable input of costs to growers and additionally, they can have a substantial impact on the environment. A new microbial pest control agent belonging to the genus Microsphaeropsis has been isolated. The application of this agent after harvest inhibits the formation of pseudothecia of V. inaequalis and consequently reduces the amount of primary inoculum the following spring which will result in a reduced spraying schedule.
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BACKGROUND OF THE INVENTION
The present invention relates weft reservoir for an alternate two-pick change type fluid jet shuttleless loom, and more particularly relates to weft reservoir in which a weft continuously supplied from a given source is provisionally reserved on a rotary drum or drums for subsequent delivery to a jet nozzle on an alternate two-pick change type fluid jet shuttleless loom such as an air jet loom wherein alternate two-pick change type weft insertions are carried out within four crank cycle.
Weft reservoirs of alternate two-pick change type are classified into two categories, the one using a weft reserving tube or tubes and the other using a weft reserving drum or drums.
From the viewpoint of weft supply, they are further classified into two categories, the one employing continuous weft supply and the other employing intermittent weft supply.
Some examples of the intermittent weft supply type weft reservoir are disclosed in Japanese Patent Publication No. 10692/64 and Utility Model Publication No. 8701/73. In the case of the weft reservoir of this type, slip of weft tends to occur when weft measuring is initiated for the first weft insertion. Excessive tension may be generated on the weft at this moment, also. Further, when weft measuring for the second weft insertion comes to end, supply of weft cannot be stopped at the correct moment due to inertia of the weft and its related part, thereby disabling correct control of the measured length of the weft. In order to avoid these troubles, it is advisable to employ the continuous weft supply system.
An example of the continuous weft supply type weft reservoir is disclosed in Japanese Utility Model No. 34306/73. In the case of weft reservoir of this type, the length of weft for about two picks reserved in a weft reserving tube at one time and delivered in two separate times for weft insertion. Consequently, the length of weft reserved in the tube before the first weft insertion is different from that before the second weft insertion, i.e. after the first weft insertion. This results in a large difference in resistance against weft delivery from the tube between the first and second weft insertions. This naturally leads to difference in weft tension which ill affects the quality of the products woven on the loom for which the weft reservoir is used. During the reservation within the tube, the weft is entrained on air flow whilst forming a U-shape. This relatively free condition of the weft during the reservation tends to form kinks and/or snarls on the weft in particular when the weft is a high twist yarn, which form weaving defects on the products woven. Use of strong air stream in the tube prevents formation of such kinks and snarls on the weft during its reservation. This, however, causes other troubles such as increased resistance against weft delivery, increased power consumption and formation of fluffs. In order to avoid the above-described drawbacks, it is advantageous to use a combination of weft reservation on a drum with continuous weft supply.
In the case of the continuous weft supply system combined with reservation on a drum, however, it is necessary to subject the weft to controlled delivery during the terminal stages of the first and second weft insertions in order to avoid variance in length of the inserted weft. In the case of the conventional weft reservoirs of weft reserving drum type, it has been technically impossible to practice such a control delivery of weft during the first difficult on a conventional weft reservoir to successfully combine the weft reserving drum system with the continuous weft supply system.
SUMMARY OF THE INVENTION
It is the basic object of the present invention to enable successful combination of the weft reserving drum system with the continuous weft supply system on a weft reservoir for an alternate two-pick change type fluid jet shutteless loom.
It is another object of the present invention to practice controlled delivery of weft from a weft reserving drum, to which the weft is continuously supplied, during the terminal stage of the first insertion on an alternate two-pick type fluid-jet shuttleless loom.
In accordance with the basic aspect of the invention, the weft is continuously supplied to a continuously rotating weft reserving drum assembly and a weft control pin is arranged facing the drum assembly in an arrangement such that the control pin is provisional registered, at a prescribed timing, at an operative position in order to be in engagement with the weft to be unwound from the drum assembly, thereby causing the controlled delivery of weft.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the weft reserving drum used for the first embodiment of the weft reservoir in accordance with the present invention,
FIG. 2 is a side view, partly in section, of the weft reservoir including the weft reserving drum shown in FIG. 1,
FIG. 3 is a simplified illustration of the weft reservoir shown in FIG. 2,
FIG. 4 is an operation diagram for the weft reservoir shown in FIG. 2,
FIGS. 5A to 5I are perspective views for showing the operation of the weft reservoir of the first embodiment,
FIG. 6 is a graph for showing the mode of weft delivery from the weft reservoir in accordance with the present invention,
FIG. 7 is a perspective view of the weft reserving drum used for the second embodiment of the weft reservoir in accordance with the present invention,
FIG. 8 is a side view, partly in section, of the weft reservoir including the weft reserving drum shown in FIG. 7,
FIG. 9 is a simplified illustration of the weft reservoir shown in FIG. 8,
FIG. 10 is an operation diagram for the weft reservoir shown in FIG. 8,
FIGS. 11A to 11H are perspective views for showing the operation of the weft reservoir of the second embodiment,
FIG. 12 is a perspective view of the weft reserving drum used for the third embodiment of the weft reservoir in accordance with the present invention,
FIG. 13 is a side view, partly in section, of the weft reservoir including the weft reserving drum shown in FIG. 12,
FIG. 14 is a diametral cross sectional view of the weft reservoir shown in FIG. 13,
FIG. 15 is a fragmentary side sectional view of a modification of the third embodiment shown in FIG. 13,
FIG. 16 is an end view of the arrangement shown in FIG. 15,
FIG. 17 is a side view, partly in section, of the fourth embodiment of the weft reservoir in accordance with the present invention, and
FIG. 18 is a perspective view showing the weft reservoir adapted for operation with an alternate two-picks change type fluid jet loom having two reserving drums in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the following description, parts belonging to different embodiments but substantially common in construction and operation are designated with common reference numerals and symbols.
Since the present invention concerns a weft reservoir of an alternate two-picks change type wherein a weft is supplied continuously, the reservoir is naturally provided with a pair of weft reserving drums 1, a pair of weft metering devices 2, a pair of weft air blowers 3, a pair of eyelets 4 for guiding the weft 5, a pair of weft grippers 6 and a pair of weft insertion nozzles 7. These weft reserving drums, however, are quite similar in construction and operation except for a prescribed operational timing. Consequently for conveniency in description, the following explanation will be made to one of the pair of weft reserving drums.
One embodiment of the weft reserving drum in accordance with the present invention is shown in FIGS. 1 and 2, in which the weft reserving drum 10 is accompanied with a fixed cover C, a weft control pin Pa operable on the weft being wound on the reserving drum 10 as hereinafter described in more detail, and a mechanism (not shown) for controlling the operation of the weft control pin Pa. An additional mechanism should preferably be annexed to the weft reserving drum for adjusting the peripheral angular position of the weft control pin Pa with respect to the weft reserving drum 10 in accordance with change in length of the weft to be inserted which is usually caused by change in weaving width.
The weft reserving drum 10 is made up of several cylindrical and conical sections arranged in axial alignment. At a position remotest from a weft ejection nozzle (not shown) of the loom a cylindrical driver section 12 is arranged around a main shaft 11 in peripheral pressure contact with a measuring roller in order to drive the latter for rotation. The driver section 12 merges into a conical weft guide section 13 converging towards the nozzle side. The conical guide section 13 is then followed by a cylindrical weft reserving section 14, whose diameter is smaller than that of the driver section 12. This section 14 is hereinafter referred to "the first weft reserving section". A like weft reserving section 17 is mounted around the main shaft 11, whose diameter is substantially similar to that of the first weft reserving section 14. This section 17 is hereinafter referred to "the second weft reserving section". A cylindrical section 16 is formed in between the first and second weft reserving sections 14 and 17, whose diameter is somewhat smaller than those of the two sections 14 and 17. This section is referred to "the annular groove section". Ends of the first and second weft reserving sections 14 and 17 mating the annular groove section 16 are provided with small flanges 14a and 17a for later-described smooth transit of the weft. At a position closest to the nozzle, a cylindrical section 18 is secured at its boss (not shown) to the main shaft 11 coupled to a given drive source (not shown), whose diameter is smaller than those of the reserving sections 14 and 17. This section is hereinafter referred to "the holder section". The above-described six sections 12 through 18 are formed in one body and rotatable together as the main shaft 11 is driven for rotation.
The cover C embraces a part of the second weft reserving section 17 and the holder section 18 leaving a small gap whilst defining an annular air passage 19 around the holder section 18. The air passage 19 communicates with the outside atmosphere via an end opening of the cover C. As in the known drum type weft reservoirs, air supplied by a given source (not shown) flows through the air passage in the same direction as the rotating direction of the weft reserving drum 10.
The control pin Pa is located at a position corresponding to the annular groove section 16 of the weft reserving drum 10 and, at prescribed timings, advances into and recedes out of the annular groove section 16 by operation of a control mechanism (not shown) including a cam and links which operate in synchronism with running of the loom.
Sequential operation of the weft reservoir in accordance with the present invention will hereinafter be explained in detail in reference to FIGS. 4 and 5A through 5I. In connection with this, the construction of the weft reserving drum 10 is simplified in these drawings as shown in FIG. 3 for easy understanding of the operation.
As shown in FIG. 4, one complete operation cycle of the weft reservoir in accordance with the present invention spans four crank cycles I through IV of the loom, i.e. 1440° crank angles. For conveniency in explanation, particular timings are set for weft insertion and operation of the control pin in the following description. In application of the present invention, however, these timings can be conditionally changed as desired.
It is assumed that the weft reserving drum 10 reserves the length of weft W for half a pick during one crank cycle of the loom.
FIG. 5A depicts the condition of the weft reserving drum 10 at a timing A in FIG. 4, i.e. at 610° crank angle when the second weft insertion has just been completed. At this timing A, the control pin Pa recedes out of the annular groove section 16 of the drum 10 and rests at its inoperative position. No weft is yet reserved on the drum 10. Since the weft W is supplied continuously from an upstream supply source (not shown), the weft W is reserved on the first weft reserving section 14 of the drum 10 at a rate of 0.5 picks/360° crank angles as the loom goes on running. Since no insertion of weft is carried out during this period, no weft is delivered from the reserving drum 10. Consequently, the length of weft reserved on the drum 10 increases gradually as shown in FIG. 4.
FIG. 5B depicts the condition of the weft reserving drum at a timing B in FIG. 4, i.e. at 970° crank angle. At this moment, the length of weft for half a pick has already been wound about and reserved on the first weft reserving section 14 of the drum 10. Delivery of weft, i.e. the first weft insertion, from the other weft reserving drum starts at 830° crank angle and terminates at the timing B, i.e. 1190.
At an appropriate timing somewhat after the timing B, i.e. at a timing after 970° crank angle but before the next wind of weft comes to the position of the control pin Pa, the control pin Pa is driven for advance into the annular groove section 16 of the drum 10 in order to be registered at its operative position. Due to the presence of the control pin Pa and the rotation of the reserving drum 10, the weft W is handed over to the second weft reserving section 17 astriding the control pin Pa and starts to be wound about and reserved on the second weft reserving section 17 of the drum 10. The angular position of the control pin Pa with respect to the reserving drum 10 is fixed so that the angular position corresponds to a peripheral position on the drum 10 whereat the length of weft for half a pick has just been reserved on the first weft reserving section 14 as shown in FIG. 5B.
The length of weft for one pick varies in accordance with the weaving width on the loom whereas the total peripheral length of each weft reserving section is constant once the diameter of the drum 10 is fixed. In order to cover this gap, the angular position of the control pin Pa should preferably be changeable along the periphery of the weft reserving drum in order to freely adjust the winding angle of the weft W on the drum 10.
FIG. 5C depicts the condition of the weft reserving drum 10 at a timing C in FIG. 4, i.e. at a moment just after the transit of the weft W to the second reserving section 17.
Running of the loom and weft reservation on the drum further continue. At a timing D in FIG. 4, the length of weft for half a pick has already been wound about and reserved on the second weft reserving section 17. More precisely, a part of the above-describe length is still on the first weft reserving section 14. This condition is illustrated in FIG. 5D. Meanwhile, delivery of weft for the second weft insertion is carried out on the other weft reserving drum during the period of 1190° to 1330° crank angle.
Since weft insertion is not yet started, winding and reservation of the weft W continue on the second weft reserving section 17 untill a timing E in FIG. 4, i.e. 110° crank angle. That is, during the period between timings D and E, a surplus of weft for 2 pick ##EQU1## is wound about and reserved on the second weft reserving section 17. Consequently, the length of weft for (1+α) pick has been reserved on the drum at the timing E. That is, the first reserving section 14 carries the length of weft for half a pick and the second reserving section 17 carries the length of weft for (0.5+α) pick. The condition of the weft reserving drum 10 at the timing E is shown in FIG. 5E.
The first weft insertion starts at the timing E and the length of weft for (0.5+α) pick on the second weft reserving section 17 is delivered. Since there is no particular resistance against this delivery of the weft W, the free delivery shown in FIG. 6 is carried out here. As the weft W on the second weft reserving section 17 has been fully delivered, the weft W now runs under the control pin Pa due to the presence of the control pin Pa and the continued rotation of the weft reserving drum 10. This condition is shown in FIG. 5F. Since the position of the control pin Pa is fixed under this condition, the length of weft W reserved on the first weft reserving section 14 is delivered therefrom, the weft delivery speed being equal to the weft measuring speed during the period from the timing F to 250° crank angle. The delivery speed of the weft W from the drum 10, i.e. the first weft reserving section 14, during this period is by far smaller than that during the free delivery. Controlled delivery of weft shown in FIG. 6 continues during the period from the timing F to a timing G. The timing F is somewhat ahead of the timing G where at the first weft insertion terminates.
At the timing G, i.e. at 250° crank angle, the length of weft for one pick has already been delivered from the drum 10. During the first weft insertion period P1, the weft W taken from the supply source is concurrently wound about and reserved on the first weft reserving section 14 of the drum 10. Imaginary increase in amount of weft reserved on the drum 10 is shown with a chain line in FIG. 4, if weft insertions were not carried out. In practice, however, weft insertions are carried out twice each accompanying concurrent delivery of the length of weft for one pick, and the amount of weft reserved on the drum 10 shifts as shown with solid lines. FIG. 5G depicts the condition of the weft reserving drum 10 when the first weft insertion terminates.
Delivery of the weft W from the drum 10 ceases at the timing G but the supply of the weft W from the source continues. Consequently, the weft W is wound about and reserved on the first weft reserving section 14 and the amount of the weft W reserved on the drum 10 starts to increase. At an appropriate timing after the timing G, i.e. at a timing after 250° crank angle but before the next wind of weft comes to the position of the control pin Pa, the control pin Pa is driven for recession out of the annular groove section 16 of the drum 10 in order to resume its inoperative position. This condition is shown in FIG. 5H.
The second weft insertion starts at 470° crank angle and the weft W is delivered again so that the amount of the weft W reserved on the drum 10 decreases. This weft delivery is the free delivery since the weft W is taken from the first weft reserving section 14. At a timing I somewhat ahead of termination of the second weft insertion at 610° crank angle, the weft W is conducted to the ejection nozzle directly from a supply roller SR of the supply source. The controlled delivery of weft starts at this moment under influence by the supply speed of the roller SR. The condition of the weft reserving drum 10 at the timing I is shown in FIG. 5I. This controlled delivery of weft lasts untill the timing A in FIG. 4.
At the timing A, i.e. at 610° crank angle, the second weft insertion terminates the drum 10 is placed under the condition shown in FIG. 5A in order to sequencially repeat the operations shown in FIGS. 5A through 5I.
As is clear from the foregoing, the combination of the control pin with the annular groove section on the drum 10 in accordance with the present invention enables reliable practice of the controlled delivery of weft even on a reserving drum type weft reservoir where the weft is continuously supplied from the given supply source, thereby assuring constant production of woven cloths with reduced loss of weft.
In the case of the above-described first embodiment of the present invention, the weft reserving drum 10 is provided with two weft reserving sections. The present invention, however, is not limited to this construction. In a modified second embodiment of the present invention, a weft reserving drum is provided with one weft reserving section only.
Such a weft reserving frum 20 is shown in FIGS. 7 and 8, in which the drum 20 is provided, just like the drum 10 of the first embodiment, with the cylindrical driver section 12, the conical weft guide section 13 and the cylindrical holder section 18 fixed on the main shaft 11. A further cylindrical section 24 is formed between the weft guide and holder sections 13 and 18. The diameter of this intermediate section 24 is somewhat smaller than that of the driver section 13. This section 24 is hereinafter referred to "weft reserving section".
A control pin Pb is disposed to the outlet side end face of the cover C by means of a shaft 25 fixed to the end face. Like the control pin Pa used for the first embodiment, this pin Pb is operationally coupled to a mechanism for controlling its operation, and swingable in a plane normal to the axis of the drum 20.
Sequential operation of the weft reservoir of this second embodiment of the present invention will hereinafter be explained in detail in reference to FIGS. 11A through 11H. In connection with this, the construction of the weft reserving drum is simplified in the drawings as shown in FIG. 9 for easy understanding of the operation.
FIG. 11A depicts the condition of the weft reserving drum 20 at a timing A, i.e. at 610° crank angle whereat the second weft insertion has been completed. At this timing A, the control Pb is placed in its inoperative position out of engagement with the weft W, and no weft is reserved on the drum 20. Since the weft W is continuously supplied, the weft W is wound about and reserved on the weft reserving section 24 at a rate of 0.5 picks/360° crank angles as the loom goes on running. No weft insertion takes place during this period and, consequently, the weft W on the reserving section 24 of the drum 20 gradually increases in amount. At a timing B, the control pin Pb is driven for swinging about the shaft 25 by the above-described control mechanism in order to be registered at its operative position. At this operative position, the point of the control pin Pb is located in front of the outlet opening the cover C and brought into engagement with the weft W unwound from the weft reserving section 24 of the drum.
The condition of the drum 20 at a timing B, i.e. at 970° crank angle, is shown in FIG. 11B. No weft insertion is initiated at this moment as yet and the length of weft for half a pick has already been reserved on the reserving section 24 of the drum 20. Delivery of weft from the other weft reserving drum, i.e. the first weft insertion, starts at 830° crank angle and terminates at the timing B, i.e. at 970° crank angle.
The drum 20 is placed under the condition shown in FIG. 11C at a timing C, i.e. at 1330° crank angle. No weft insertion is initiated at this moment as yet and the length of weft for one pick has been reserved on the reserving section 24 of the drum 20. Incidently, delivery of weft from the other weft reserving drum, i.e. the second weft insertion, starts at 1190° crank angle and terminates at the timing C, i.e. at 1330° crank angle.
Reservation of weft on the drum 20 further goes on during the period from the timing C to a timing D, i.e. to 110° crank angle. During this period, the length of weft for α pick ##EQU2## is further reserved on the weft reserving drum 20. Therefore at this moment, the length of weft for (1+α) picks has already been reserved on the drum 20. This condition is shown in FIG. 11D.
The first weft insertion starts at the timing D and the reserved weft is delivered from the drum 20 while new weft taken from the source is concurrently wound about and reserved on the drum 20. Since the length of weft for (1+α) picks has already been reserved on the drum 20, the weft W is subjected to the free delivery in FIG. 6.
As the weft W on the weft reserving section 24 of the drum has been fully delivered, the weft W now runs under the control pin Pb due to the presence of the control pin Pb and the continued rotation of the weft reserving drum 20. This condition is shown in FIG. 10E.
Thus, the weft W is delivered from the drum 20 whilst being kept in engagement with the control pin Pb placed in the operative position. This delivery speed is equal to the weft measuring speed. The weft W is now subjected to the controlled delivery in FIG. 6. The condition of the weft reserving drum 20 is shown in FIGS. 11E and 11F. This timing E is somewhat ahead of a timing F whereat the first weft insertion terminates.
By the timing F whereat the first weft insertion terminates, the length of weft for one pick has been delivered from the weft reserving drum 20. During this weft insertion period P1, the weft W taken from the source is wound about and reserved on the weft reserving section 24 of the drum 20. Imaginary increase in amount of weft reserved on the drum 20 is shown with a chain line in FIG. 10, if weft insertions were not carried out. In practice, however, weft insertions are carried out twice each causing concurrent delivery of the length of weft for one pick, and the amount of weft reserved on the drum 20 shifts as shown with solid lines.
Delivery of weft from the drum 20 terminates at the timing F and supply of the weft W from the source continues. Thus, the amount of weft reserved on the drum 20 again increases. The control pin Pb is driven by swinging back to its initial inoperative position by the above-described control mechanism at an appropriate timing G, more specifically at a timing after completion of the first weft insertion but before the next wind of weft comes to the position of the control pin Pb. At this inoperative position, the control pin Pb is out of engagement with the weft W to be unwound from the weft reserving drum 20.
The second weft insertion starts at 470° crank angle, the weft W reserved on the drum 20 is again delivered and the amount of weft on the drum 20 accordingly decreases. The weft W is here subjected to the free delivery shown in FIG. 6. At a timing H just ahead of termination of the weft insertion at 610° crank angle, the weft W starts to be delivered directly from the supply roller SR of the source and, due to influence of the weft supply speed, subjected to the controlled delivery shown in FIG. 6, which lasts until the timing A. The condition of the weft reserving drum 20 at the timing H is shown in FIG. 11H.
The second weft insertion terminates at the timing A and the weft reserving drum 20 resumes the condition shown in FIG. 11A in order to repeate the above-described operations as shown in FIGS. 11A through 11H.
As long as the control pin Pb is engageable with the weft W in its operative position and placed out of such an engagement in its inoperative position, the control pin Pb may be disposed to any body other than the cover C. It is also employable in the present invention that, during the second weft insertion, the control pin Pb is driven for engagement with the weft W to be unwound from the weft reserving drum.
In connection with the first embodiment of the present invention in which the drum includes first and second cylindrical weft reserving sections in axial alignment, a wide variety of modifications are employable.
One of such a modification is shown in FIGS. 12 and 13, in which an annular projection delimits the first and second weft reserving sections as a substitute for the annular groove section in the first embodiment.
In FIGS. 12 and 13, a weft reserving drum 30 is accompanied with fixed covers C1 and C2 combined in axial alignment, a ring assembly 40 coaxially rotatable about the drum 30, a control pin Pc disposed to the cover C2 and a control mechanism (not shown) for driving the ring assembly 40 for turning.
The first cover C1 is mounted to a horizontal shaft 1 fixed to a framework (not shown) of the loom. When necessary, the cover C1 is turnable about the shaft 1 which extends normal to the axial direction of the weft reserving drum 30. The second cover C2 is axially turnable relative to the first cover C1 in order to shift the angular position of the control pin Pc along the periphery of the weft reserving drum 30 in accordance with change in weaving width. The ring assembly 40 is also axially turnable together with the second cover C2. To this end, the ring assembly 40 is accompanied with a driver rod 41 (see FIG. 14) coupled to a suitable drive source (not shown).
The control pin Pc has a shaft 2 axially rotatably received in a hole formed in the end face of the second cover C2. The control pin Pc is further provided with a projection 3 idly received in a skew groove 42 formed in the end face of the ring assembly 40.
As shown in FIG. 12, the weft reserving drum 30 includes the cylindrical driver section 12, the conical weft guide section 13, the cylindrical first weft reserving section 14, the cylindrical second weft reserving section 17, the cylindrical holder section 18, the main shaft 11 and an annular projection 31 delimitting the first and second weft reserving sections 14 and 17. The fixed cover C1 defines the air passage 19 around the holder section 18 of the drum 30.
The control pin Pc is arranged on the second cover C2 at a position corresponding to the position of the annular projection 31 on the drum 30. As the ring assembly 40 is driven for axial turning by movement of the driver rod 41, the projection 3 swings about the shaft 2 held by the second cover C2 whilst being guided by the skew groove 42 formed in the ring assembly 40. Consequently, the control pin Pc swings about the shaft 2 also since the projection 3 is formed in one body with the control pin Pc. This movement of the control pin Pc is shown in FIG. 14.
In the position shown with solid lines in FIG. 14, the hooked point of the control pin Pc is located near the base of the annular projection 31 on the drum 30. Whereas, in the position shown with chain lines in FIG. 14, the hooked point of the control pin Pc is located above the top of the annular projection 31.
The control pin Pc is provided at its hooked point with a hollow nose 4a and a hook 4b both adapted for engagement with the weft.
When the weft W is handed over from first to second weft reserving section passing over the annular projection 31, the weft W is caught by the hook 4b of the control pin Pc. Due to the relatively small crossing angle of the weft W with the annular projection 31 at this transit, the weft W is liable to fall off the hook 4b of the control pin Pc. In order to prevent this accident, the hook 4b is deeply constructed. The point of the hook 4a converges forwards for engagement of the weft W with the control pin Pc in the lowered position (solid lines) i.e. the operative position.
During the controlled delivery shown in FIG. 6, the weft W comes into engagement with the hollow nose 4a of the control pin Pc. In this case, the crossing angle of the weft W with the annular projection 31 of the drum 30 and, therefore, the weft W does not fall off the nose 4a despite its relatively shallow hollowness. This shallow construction of the hollow nose 4a enables easy disengagement of the weft W with the control pin Pc moving upwards.
In the foregoing description, the weft reserving drum 30 is assumed to rotate in the direction shown with an arrow in FIG. 14, i.e. in the counterclockwise direction. When the weft reserving drum 30 rotates in the opposite direction, the hollow nose 4a should be deeper in construction whereas the hook 4a should have a shallower construction.
The sequential operation of the weft reservoir of this embodiment is substantially same as that of the first embodiment and the timing diagram for the first embodiment given in FIG. 4 is applicable to this embodiment. At the timing H, the control pin Pc rises towards the inoperative position and lower towards the operative position at a timing just after the timing B.
A further modification is shown in FIGS. 15 and 16, in which the weft reserving drum 30 is provided with an overhand type annular projection 32 inclining towards the nozzle side and the hooked point of the control pin Pc extends somewhat under the annular projection 32. The inclined overhang construction of the annular projection 32 assures successful engagement of the weft W with the control pin Pc. Like the foregoing embodiment, the control pin Pc is held by the second cover C2 by means of the shaft 2 and provided with the projection 3 received in the skew groove 42 in the ring assembly 40.
In the case of the foregoing embodiments each having an annular projection, respectively, the control pin Pc is located on the nozzle side of the annular projection. The control pin may, however, be arranged on the opposite side of the annular projection. In this case, the overhang type annular projection should be inclined over the hooked point of the control pin.
In the case of the foregoing embodiments in which a weft reserving drum is provided with a pair of weft reserving sections in axial alignment, the two weft reserving sections are driven for rotation at an equal rotation speed by a common main shaft. In connection with this, however, the pair of weft reserving sections may be rotated at different rotation speeds in a further modified embodiment of the present invention.
In accordance with the third embodiment of the present invention, the weft reservoir is provided with a pair of weft reserving drums in axial alignment. The pair of weft reserving drums are driven for rotation at different rotation speeds. That is, the peripheral speed of the second weft reserving drum closer to the nozzle is equal to or larger than that of the first weft reserving drum closer to the supply source of weft. A control pin is arranged facing the border between the two weft reserving drums.
The first weft reserving drum corresponds to the above-described first weft reserving section whereas the second weft reserving drum corresponds to the above-described second weft reserving section.
Prescribed movement of the control pin causes transit of the weft from the first to the second weft reserving drum and engagement of the control pin with the weft during weft insertion enables controlled delivery of the weft.
Difference in peripheral speed between the two weft reserving drums well avoids slack of weft at transit from the first to the second drum. Difference in diameter between the drums assures reliable engagement of the control pin with the weft in order to enable smooth transit and the controlled delivery of the weft.
Such further embodiment of the present invention is shown in FIG. 17, in which the weft reservoir is provided with a pair of weft reserving drums 50 and 60 in axial alignment.
The first weft reserving drum 50 is provided, in axial alignment, with a cylindrical driver section 52 for pressure contact with the supply roller SR, a conical weft guide section 53 following the driver section 52 and a cylindrical weft reserving section 54, in one body with each other. The reserving section 54 is smaller in diameter than the driver section 52.
The second weft reserving drum 60 is provided, in axial alignment, with a cylindrical weft reserving section 67 and a cylindrical holder section 68.
The weft reserving section 54 of the first drum 50 is larger in diameter than the weft reserving section 67 of the second drum 60.
The first drum 50 is fixed to a cylindrical shaft 102 whereas the second drum 60 is fixed to an auxiliary shaft 101 extending coaxially through the cylindrical shaft 102. First and second covers C1 and C2 are mounted, in axial alignment, to a framework 103 of the weft reservoir whilst covering the first and second weft reserving drums 50 and 60 in order to define the air passage 19 around the holder section 68 of the second drum 60. The first cover C1 is axially turnable about the second cover C2 so that the angular position of a control pin Pd, which is carried by the first cover, is shiftable along the periphery of the second drum 60 in accordance with change in weaving width on the loom.
The control pin Pd is swingably mounted to the first cover C1 by means of a horizontal pivot pin 104 fixed to the first cover C1 whilst extending substantially normal to the axial direction of the weft reservoir. The control pin Pd is driven for swinging by a rod 105 which reciprocates axially at prescribed timings in synchronism with running of the loom. This control pin Pd is adapted for provisional engagement with the weft W taken from the supply source at prescribed timings in order to assist transit of the weft W from the first to the second weft reserving drum. The control pin Pd further causes the control delivery shown in FIG. 6 by its provisional engagement with the weft W unwound freely from the second drum 60. When the rod 105 assumes the position shown with solid lines in FIG. 17, the control pin Pd is kept in engagement with the weft W. As the rod 105 shifts in the direction shown with an arrow A, the control pin Pd assumes the position shown with chain lines and is brought out of engagement with the weft W. In the inoperative position, the control pin Pd is almost fully accommodated within the first cover C1.
The auxiliary shaft 101 is rotatably supported by a gear casing 106 fixed to the framework 103 and the cylindrical shaft 102 by means of bearings 107, 108 and 109. Whereas the cylindrical shaft 102 is rotatably supported by the framework 103 by means of bearings 110 and 111. The first weft reserving drum 50 is fixed to the cylindrical shaft 102 by a fastening nut 112 whereas the second weft reserving drum 60 is fixed to the auxiliary shaft 101 by a fastening nut 113.
In the gear casing 106, a gear 114 is fixed to the auxiliary shaft 101 and a gear 115 is fixed to the cylindrical shaft 102, the gears 114 and 115 being somewhat spaced from each other in the axial direction of the weft reservoir. The gears 114 and 115 and in meshing engagement with gears 116 and 117 fixed to the main shaft 11, respectively. Consequently, rotation of the main shaft 11 is transmitted on the one hand to the second weft reserving drum 60 via the gears 116, 114 and the shaft 101 and, on the other hand, to the first weft reserving drum 50 via the gears 117, 115 and the shaft 102.
The gear ratios between the gears 116 and 114, and between the gears 117 and 115 are designed in the case of this embodiment so that the peripheral speed of the second drum 60 is equal to or larger than that of the first drum 50. Bearings 118 and 119 are arranged for rotatable coupling of the main shaft 11 with the gear casing 106 and the framework 103.
Operation of this embodiment is substantially similar to that of the first embodiment and its operation diagram is substantially similar to that shown in FIG. 4.
As long as the above-described relationship in peripheral speed is satisfied, the relationship in diameter between the two drums may be reversed.
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A weft reservoir for a alternate two-pick change type fluid jet shuttleless loom includes a continuously rotating drum assembly for provisionally reserving a weft continuously supplied from a given source and a control pin arranged facing the drum assembly and driven, at a prescribed timing, for provisional engagement with the weft being unwound from the drum assembly, thereby causing the controlled delivery of weft during the terminal stage of each weft insertion. Stabilized quality of the products with reduced waste of weft is attained.
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FIELD OF THE INVENTION
The present invention relates to a valve for controlling the flow of the fluid through a bore and particularly, but not exclusively, the invention relates to a ball valve for use in the oil and chemical process industry.
BACKGROUND OF THE INVENTION
Ball valves are commonly used in both industries. The type of ball valve of interest in relation to controlling flow of a fluid is an apertured ball valve such as is disclosed in applicant's co-pending published Patent Application No. WO 93/03255 which was published on Feb. 18, 1993. In an apertured ball valve the valve operation or function may be broken down into two separate stages. Firstly, the ball moves between an open and a closed position by rotating through 90° such that the ball aperture from an orientation coaxial with the flow direction, i.e. when the valve is open, to a position whereby the ball aperture is normal or perpendicular to the flow direction. Secondly, the valve seals in the closed position to prevent flow through the bore across the ball valve. Therefore, the on-off control of flow through the valve is achieved by rotating the ball through 90° within the valve housing.
There are two basic types of ball valve mechanism which currently exist which fulfil the above functions. Firstly, there is the trunnion mounted ball system in which the ball element is positionally constrained inside the valve, usually by radial bearings. The ball is rotated by the application of torque to the trunnion. Sealing occurs as a result of the valve seat “floating” onto the ball element. The advantage of this system is that it provides highly reliable rotation between the valve open and the closed positions. The principal disadvantage of this system is that seal reliability is reduced because the sealing force only develops in proportion to the annular area of the valve seat. Thus, when trunnion mounted ball systems are used in high pressure wells and especially those in which the well fluid has a high proportion of particulate matter, being generally known as “aggressive” wells, the pressure is such that the particulate matter can leak past seals between the ball and the valve seats and become jammed in all surfaces of the valve. This often results in the valve not achieving integrity of sealing. In such cases this type of ball valve is unable to operate properly in such conditions.
The second type of ball valve mechanism which effects the abovementioned function is known as the “floating ball system”. In this system the ball is not positionally constrained relative to the valve body. Rotation is caused by the application of force to a point which is offset from the ball centre which, in conjunction with the mating curvatures of the ball and seat, cause the ball to rotate. Sealing occurs as a result of the ball “floating” onto the valve seat. The advantage of this mechanism is that the reliability of the seal is increased because the sealing force develops in proportion to the circular area of the ball to seat contact. The disadvantage of this type of mechanism is that the rotational reliability is reduced as the friction factor between the ball and seat are considerably larger than that of trunnion mounted devices. With aggressive types of wells and particulate flows of the type described above, the reliability of this valve creates a problem in that the valve seizes between the open and the closed position giving rise to serious problems in both operational and safety terms.
An object of the present invention is to provide improved ball valve which obviates or mitigates at least one of the aforementioned disadvantages.
SUMMARY OF THE INVENTION
This is achieved by allowing a very slight movement of a ball valve retaining mechanism to allow that the ball element to be unloaded off the valve seat during rotation, but remain in contact with the valve seat so as to prevent debris ingress between the ball and the valve seat, and to instantaneously reload onto the valve seat upon the event of closure. This instantaneous and automatic redirection of the reaction load path at the occurrence of closure provides an effective seal against high pressure aggressive fluids to prevent fluid escaping beyond the valve components whilst, at the same time, allowing effective rotational movement of the valve to occur without providing rotational reliability.
This solution allows conflicting load paths through the valve to be resolved, namely through the trunnion during rotation and through the valve seat during sealing.
The slight movement of the ball retaining mechanism which is required may be variable depending on a number of factors but requires to be only very slight and in the preferred arrangement hereinafter described is of the order of 0.025″ (0.60 mm).
According to one aspect of the present invention, there is provided a ball valve structure comprising:
a valve housing having a wall defining a housing bore having a longitudinal bore axis,
an apertured ball element disposed within a ball cage, said ball element and said ball cage being disposed within said bore for rotation between a first position in which said ball element is oriented such that the aperture of the ball element is aligned with the bore, this position defining a valve open position, and a second position in which said ball element is rotated through approximately 90° such that said ball element fully obstructs said bore, this position being defined as the closed position,
piston means disposed within said housing and coupled to said ball element such that movement of said piston means in the direction of the longitudinal axis of said bore causes said ball element to rotate between said open and said closed position,
valve seat means disposed downstream of said ball element between said ball element and a valve housing cap, said valve seat means being coupled to first resilient means for applying a first spring force for biasing said valve seat into contact with said ball element as it moves between said open and said closed positions,
compression spring means coupled to said piston means and responsive to movement of said piston means to move between a first position defining a first compressive spring force sufficient to maintain said ball element in said closed position and a second compressed position in which said piston is actuated to move that said ball element to said open position, said first compression spring means being retained in a direction substantially parallel to said longitudinal bore axis within said housing by a top plate means and by said lower plate means,
a generally tubular mandrel coupled to said ball cage and to said bottom plate means, such that said mandrel, said ball cage and ball element and said valve seat are constrained to be moved together,
second resilient means disposed between the bottom plate means and said valve housing for applying a second spring force to said mandrel assembly for biasing said mandrel assembly, said ball element and said ball cage towards said valve seat, said second spring force being selected to be less than the force of said compression spring means when said ball element is in said open and closed position but greater than the spring force of said first resilient means when said ball valve is in the closed position,
the arrangement being such that in response to an applied force said piston means is moveable to rotate said ball element to an open position and to compress said compression spring means to a compressed state in which a compressed spring force in said compressed state which is greater than the second spring force applied by said second resilient means, and the first resilient means applies said first spring force to said valve seat to bias said valve seat to remain in contact with said ball element in said open position and,
in the absence or removal of the force applied to said piston means, said compression spring means urges said piston means towards said housing cap such that such ball element is rotated by substantially 90° to a just-closed position where said top plate means abuts said tubular mandrel to limit the decompression of said first compression spring means and, substantially instantaneously, said second resilient means urges said tubular mandrel, said ball cage and said ball element upwardly by a minimal amount relative to said piston means against said valve seat to create a valve closed intensifying condition to provide a relatively strong and effective initial seal between said valve seat and said ball element.
Preferably, said piston means is a tubular or annular piston having apertures in an interior wall thereof for receiving pins or trunnions coupled to said ball element such that rectilinear movement of said piston within said valve housing causes said ball element to rotate substantially 90° between a fully open and a fully closed position.
Preferably also, said ball cage surrounds the ball element and provides a sealed unit as said ball element rotates to prevent passage of debris from the bore of said housing to the components of the ball valve.
Advantageously, said compression spring means is provided by a stack of radially, and circumferentially, spaced helical coil springs, each coil spring bring retained between said top plate means and said lower plate means, said top plate means being moveable with said springs in response to force applied from said piston.
Conveniently, a lower seal ring is coupled to said mandrel beneath said lower plate means.
The second resilient means is provided by a Belleville spring disposed between the base of the lower seal ring and the valve housing. Similarly, the first resilient means is provided by a Belleville spring, which is coupled between the valve seat and the housing cap, for biasing valve seat into contact with said ball element.
Conveniently, said valve housing cap has a port and conduit to the interior of said housing cap for receiving hydraulic fluid for actuating said piston to move downwardly against the spring force of helical coil springs.
Conveniently, eighty helical coil springs are disposed around the periphery of the valve housing to supply a spring force of about 50,000 lbs (225 Kilonewtons (Kn)) when the valve is located in the open position and to supply a spring force of approximately 30,000 lbs (135 Kn) when said valve is in a closed position. The lower Belleville spring provides an upward spring force of approximately 25,000 lbs (112 Kn) and the upper Belleville spring provides a downward force of approximately 10,000 lbs (45 Kn).
Conveniently, the distance moved by the assembly of the mandrel, ball cage and ball element and valve seat assembly between the just-closed position and the intensified position is about 0.025″ (0.60 mm).
Advantageously, the pin or trunnion coupled to said ball element for rotation of the ball element by said piston is disposed in windows or apertures in said piston with clearance to allow the pin to float axially upwards thereby allowing the valve components to reposition themselves in response to spring forces and hydrostatic end loads to the intensifying condition.
According to another aspect of the present invention, there is provided a method of minimising the ingress of debris between a ball valve element and valve seat as the ball valve is moved between an open and a closed position, the method comprising the steps of, compressing the first compression spring means, having a first uncompressed spring force, to a second position having a second compressed spring force greater than said first compressed spring force, and simultaneously rotating said apertured ball element to said open position,
biasing a valve seat into contact with said ball element as the ball element rotates from the open to the closed position, said biasing being achieved using a first resilient means having a resilient spring force,
providing a second resilient spring for applying an upward force to an assembly consisting of a mandrel means, a ball cage and ball element and said valve seat, said second resilient spring force being less than the second compressed spring force of said first compression spring means when said valve element is in said open position but being greater than said spring force of said first resilient means,
moving the first compression spring means upwardly in the absence or removal of an applied force to cause the ball element to rotate through 90° and to a just-closed piston, retaining said valve seat in contact with said ball element by said first resilient means, and
providing an upward biasing force flowing through said mandrel assembly, said ball cage and said ball element so as to move the assembly upwards by a relatively small amount to provide an intensifying effect between said ball element.
In accordance with another aspect of the present invention, there is provided a ball valve for use with said ball valve structure, said improved ball valve comprising an apertured ball valve having pin means coupled thereto for rotating the ball valve between an open and a closed position in response to an applied force, ball cage for surrounding said ball element except in the region of a valve bore, said cage sealingly engaging said valve seat on one side of the ball and being adapted to be coupled to a mandrel on the other wide of the ball thereby providing a mechanical barrier between the movement of debris from the bore of said ball valve structure to working components of said ball valve structure.
Preferably, said cage is formed by two matching split shells which, when coupled together, form the cage surrounding said ball element.
Each shell has a circular window therein for receiving and engaging with the trunnions of the ball element via plain bearings.
Preferably, the lower end of the cage is threaded into the mandrel.
Conveniently, the trunnions engage with a cylindrical piston which is adapted to be move rectilinearly within a valve housing in response to application of hydraulic pressure, such that when pressure is applied, or removed, the piston moves in the direction of the longitudinal axis of the bore such that the ball element moves within said cage between an open and a closed position.
According to a further aspect of the present invention, there is provided a method of equalising pressure across the ball valve in response to an over pressure from above the ball valve, the method comprising the steps of:
exposing a portion of the main valve actuating means to bore pressure above said valve element, causing downward movement of said valve actuating means in response to said over pressure to rotate the ball partially open to allow pump through of fluid.
It will be understood that the valve seat spring maintains the valve seat in contact with the ball element throughout the pressure equalisation process.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the invention will be become apparent from the following description when taken in combination with the accompanying drawings in which FIG. 1 is a longitudinal sectional view through a ball valve structure in the closed position, in accordance with an embodiment of the present invention;
FIG. 2 depicts a diagrammatically longitudinal sectional view of a valve structure in accordance with an embodiment of the invention with the valve shown in the open position and parts of the valve element shown enlarged for clarity;
FIG. 3 depicts a split longitudinal sectional view similar to that shown in FIG. 2 but with the ball valve in the just-closed position;
FIG. 4 depicts a similar view to FIG. 3 but with the ball valve in the closed and intensifying position, and
FIG. 5 depicts a computer-aided drawing of an exploded view of part of a ball valve structure showing the ball element located in part of the ball cage assembly for mounting in a generally cylindrical piston in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Reference is first made to FIG. 1 of the drawings which depicts a high integrity ball valve structure, generally indicated by reference numeral 10 , which comprises an outer cylindrical housing 12 coupled to a valve housing cap 14 by an annular threaded collet 16 .
The valve housing 12 and valve cap 14 define an internal longitudinal bore, generally indicated by reference numeral 18 , which extends the length of the housing 12 and along which well fluids can be conveyed or blocked, depending upon whether the valve is open or closed as will be later described.
Disposed within the valve housing is an apertured ball element, generally indicated by reference numeral 20 , which, as will be described, is rotatable through 90° between a closed position, as shown in FIG. 1, and a fully open position as shown in FIG. 2 .
The ball element 20 is disposed within a ball 22 for totally enclosing the ball, in use, to provide a mechanical barrier against movement of debris from the bore of the tool to the working from components as will also be later described. The apertured ball element 20 has protruding from it sides two cylindrical bosses or trunnions 24 , best seen in FIGS. 1 and 5. These trunnions pass through circular apertures in the cage 24 via main bearings for engaging in windows 25 (best seen in FIGS. 1 and 5) in valve actuating means in the form of a cylindrical piston 26 . The apertured ball element is of the type disclosed in applicant's co-pending International Patent Application Publication No. WO 90/03255.
The cylindrical piston 26 is shown abutting the lower surface 14 a of annular cap 14 . On the left side of the annular cap 14 is shown an hydraulic inlet line 28 through which hydraulic pressure can be applied to piston 26 for rotation of the ball valve as will be later described.
It will be seen that the base 26 a of the piston 26 . abuts a top annular plate 30 or gusset ring 30 beneath which is disposed a magazine of forty nested helical coil compression spring stacks 32 , of which four are shown in the interests of clarity. The spring stacks 32 are spaced around the circumference of the housing, and each stack is located between the top annular plate 30 and a lower plate or end seal 34 . As will be described, when the piston 26 is moved within the valve housing 16 , the spring stacks 32 move between an uncompressed position as shown in FIG. 1 and a compressed position shown in FIG. 2 of the drawings.
The valve cage 22 is threadedly connected to a mandrel 36 which extends longitudinally within the bore 18 of the housing 16 . The base 36 a of the mandrel 36 a has a threaded exterior 38 which is coupled to an external seal ring 40 . The upper part of the mandrel 36 has a shoulder region 42 against which abuts the top annular plate 30 so that the maximum uncompressed position of the coil springs is as shown in FIG. 1 of the drawings. Disposed beneath the seal ring 40 is a mandrel Belleville spring 44 which exerts an upward force of approximately 25,000 lbs (112 Kn) on the seal ring 40 and mandrel assembly over a short operating range. The mandrel spring 44 is shown located beneath the seal ring 40 and a shoulder 46 of the housing 16 .
The valve cage 22 is threadedly connected to a mandrel 36 which extends longitudinally within the bore 18 of the housing 16 . The base 36 a of the mandrel 36 a has a threaded exterior 38 which is coupled to an external seal ring 40 . The upper part of the mandrel 36 has a shoulder region 42 against which abuts the top annular plate 30 so that the maximum uncompressed position of the coil springs is as shown in FIG. 1 of the drawings. Disposed beneath the seal ring 40 is a mandrel Belleville spring 44 which exerts an upward force of approximately 25,000 lbs (45 Kn) on the seal ring 40 and mandrel assembly over a short operating range. The mandrel spring 44 is shown located beneath the seal ring 40 and a shoulder 46 of the housing 16 .
Operation of the ball valve will now be described and the description will examine a functional cycle from the fully open position as shown in FIG. 2 to the fully closed position shown in FIG. 3 and the intensified fully closed position shown in FIG. 4 .
To orient and maintain the valve in the open position, hydraulic pressure is applied through the open port 28 to the top of the piston 26 b . This pressure develops a force which pushes the cylindrical piston 26 onto the top annular plate 30 which bears on the helical coil spring stack 32 . The lower end of the spring stack 32 is fixed via lower plate 34 which abuts a shoulder 60 of the valve housing 16 . The coil spring stack 32 then bears on the seal ring 34 and retainer ring 40 which is an integral part of the mandrel assembly and the mandrel assembly is, in turn, pushed down onto the body shoulder 46 best seen in lowermost balloon part 62 in FIGS. 3 and 4. The mandrel spring 44 is compressed by the higher force developed by the hydraulics which is transmitted through the highly compressed main spring pack.
As the piston 30 moves down, the trunnions 24 engage with the windows of the piston 26 such that the ball is rotated from the closed position shown in FIG. 1 to the fully open position shown in FIG. 2 such that the bore of the ball element 20 b is aligned with the internal bore of the mandrel 36 and the bore of the valve housing 18 .
The valve seat spring 50 disposed between the valve seat 48 and the top cap 14 provides a force to the valve seat 48 to “follow” the ball element 20 to the lower position shown in FIG. 2 to maintain a preloaded contact with the surface 20 a of the ball element 20 to reduce the possibility of debris from the bore 18 , when in the open position shown in FIG. 2, becoming entrained between the valve seat 48 and the surface 20 a of the ball element and thus contaminating the valve components.
Thus, in the position shown in FIG. 2 the stack of helical coil springs 32 are compressed and the piston 26 has been moved downwards to rotate the ball valve 20 through 90° to the position shown so that the ball element bore 20 b is aligned with the bore 18 of the valve housing 16 to allow fluid flow through the ball valve assembly.
Reference is now made to FIG. 3 of the drawings which depicts the valve in what is known as the “just-closed” position. In this position the hydraulic actuating force has been removed from the piston 26 and the main helical coil spring stack 32 has returned the piston to its uppermost position thereby rotating the ball element through 90° (as was seen in FIG. 1) such that the bore 18 of the valve assembly is blocked to prevent fluid flow therethrough. At this point there is a significant change of reaction load path; the main coil spring stack 32 has closed the valve and pushed the piston 26 through its 3.0″ (151.2 mm) stroke. The spring stack 32 simultaneously shoulders out on the underside of the mandrel shoulder 42 . This means that the force which was pushing up on the piston 26 , and down on the seal ring 40 , is now pushing up on the mandrel 36 and down on the seal ring 40 . Because the mandrel 36 and seal ring 40 are both part of the mandrel assembly, the force therefore becomes neutral or self-balancing. Therefore, at this particular point the main coil spring stack 32 ceases to have an effect on the position of the mandrel assembly 36 which is hydraulically neutral, that is both the pressure within the bore 18 and the control pressure have no tendency to effect the mandrel position of the assembly.
After the main spring stack has shouldered out on the mandrel shoulder 42 , the only external force acting on the mandrel assembly comes from the mandrel spring 44 and the seat spring 50 . Because the mandrel string 44 is considerably stronger than the seat spring 50 , the mandrel assembly (the mandrel, ball cage and ball element, piston and valve seat) is pushed up until the valve seat 48 shoulders out on the top cap 14 as described above. Although there is no rigid connection between them, the seat and mandrel assembly move as one system due to the preloaded Belleville springs 44 , 50 at either end of the system.
Reference is now made to FIG. 4 of the drawings which depicts the ball valve when the ball element 20 is in the “intensifying” position. In this position the ball element 20 has been pushed up onto the valve seat 48 by the mandrel spring 44 . In addition, the mandrel assembly, ball and valve seat have all moved up 0.025″ (0.7 mm) towards the valve cap 14 because of the higher force exerted by the mandrel spring 44 over the seat spring 50 . Therefore, the ball element 20 is preloaded onto the valve seat 48 which, in turn, is shouldered out on the top cap 14 . Any further forces across the ball element, such as differential pressure, are reacted through this load path thereby providing intensification in proportion to the circular seal contact area.
Still referring to FIGS. 3 and 4, it will be understood that these figures illustrate the transition between the “just-closed” and “intensifying” positions and it will be appreciated that in FIG. 3 the piston 26 returns the trunnion or pin 24 to the fully closed position best illustrated by the bubble 64 . Thereafter, the trunnion or pin 224 is allowed to float axially upwards within its connection with the piston 26 . This float allows the valve components to reposition themselves in response to spring force and hydrostatic end loads to the intensifying condition shown in FIG. 4 . This is why the overall travel of the piston is slightly greater than the actual stroke of the ball (3;000″ (151.2mm)). The piston travel includes both the functional stroke (3.000″ (151.2 mm)) and the residual force (0.050″ (1.2 mm)).
In particular it will be appreciated that by referring to the enlarged bubbles on FIGS. 3 and 4 it will be seen that the travel of the mandrel assembly between the just-closed position and the intensifying position is 0.025″ (0.7 mm); this movement being sufficient to provide the aforementioned intensifying effect.
In order to ensure that the piston 26 travels fully home to permit the intensifying effect, it will be understood that a number of the helical coil springs 32 a on the radially outer portions of the spring stack 36 are arranged to penetrate through the top plate 30 and act directly on the piston 26 as is best seen in FIG. 1 and bubble 66 in FIG. 4 of the drawings. These springs 32 a provide the main part of the force to deliver the piston 26 to the fully up position but additional force is provided for both the functional and residual portions of piston stroke by the seal arrangement between the piston and the tool bore. An inequality of seal diameters between the piston and top cap seal, and between the piston and the mandrel seal means that any pressure in the tool bore has the effect of driving the piston upwards.
It will be readily understood that the ball valve structure hereinbefore described provides both rotational reliability and seal reliability with the result that the ball valve can be used in aggressive wells environment which have hitherto been impossible with existing valves. It will also be understood that, as with the ball valve described in applicant's co-pending application, the ball element may have hardened tungsten carbide edges which are shaped such that actuation of the valve to a closed position provides sufficient force to shear or cut coil tubing and comply with relevant safety requirements.
It will also be understood that the ball valve structure hereinbefore described includes other features which improve the operational reliability. For example, the totally enclosed cage 22 engages above the ball 20 with the seat 48 and below the ball with the mandrel 36 . The cage 22 provides a mechanical barrier against the movement of debris from the bore 18 of the valve structure to the working components of the valve. It is important for the functionality of the valve that any pressure in the bore 18 is allowed to act through the cage and consequently the cage is not pressure retaining in any way.
The mechanism by which the valve pumps through (equalises in response to an overpressure from above) is also improved in relation to prior art ball valve structures. Previously equalisation of pressure occurred as a result of the ball floating away axially from the seat thereby creating an annular flow path between two components. This annular flow path resulted in debris becoming trapped between the ball and the seat when the differential pressure was removed. This is minimised with the present structure because the pump through mechanism now maintains the valve seat 48 in constant contact with the ball surface 20 a . A portion of the main cylindrical actuation piston 26 is exposed to bore pressure above the ball element 20 . When a positive differential pressure is created above the valve, it acts on this portion of the piston 26 which moves downwardly in response. Hence, the ball 20 rotates to a partially open position to allow pump through of fluid. The seat spring 50 maintains contact between the ball surface 20 a and the valve seat 48 throughout the process.
Wiper seals have been included in front of all hydraulic seals which are exposed to production water surfaces. These wiper seals displace any debris and protect the hydraulic seals and the respective mating surfaces.
It will be appreciated that various modifications may be made to the valve structure hereinbefore described without departing from the scope of the invention. For example, although the valve structure requires 40 helical coil springs it will be appreciated that any suitable number may be used depending on the spring strength. In addition, the exact spring tensions of the mandrel spring, seat spring and compression strings may be varied, although it is a requirement that the spring force of the mandrel spring be greater than the seat spring sufficient to allow the mandrel assembly to move up to the intensified position, and the spring force in the coil spring stack when in the just-closed position, must be greater than the spring force of the mandrel spring.
It will be appreciated that the valve housing and internal valve structure may be of any suitable shape to allow the components to be disposed in the valve housing sufficient to achieve the function hereinbefore described, namely that there is an upward movement of the assembly to create an intensified position when the valve is fully closed. It will also be understood that premium corrosion-resistant materials are preferred.
The principal advantage of the invention over the prior art is that it provides the ball valve structure with both rotational reliability and seal reliability such that it can be used in aggressive well environments. The design minimises the possibility of the mechanism binding because the valve seat stays in contact with the ball element throughout its rotation and this also eliminates the possibility of debris ingress between the ball and the seat. The provision of wiper seals also protects the hydraulic seals from debris damage and because the ingress of debris is minimised to working components, the component life is increased and this reduces replacement frequency. This effectively increases the working life of the valve. The coil spring stack also provides an increase failsafe close spring force which also provides increased passive cutting capacity. Furthermore, because rotational friction forces are minimised valve closure times are significantly reduced.
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A ball valve ( 10 ) is described which has a ball valve retaining mechanism which, when subject to very slight movement, allows a ball element ( 20 ) to be unloaded off a valve seat ( 48 ) during rotation, but remain in contact with the valve seat ( 48 ) so as to prevent debris ingress between the ball and the valve seat, and to instantaneously reload onto the valve seat upon the event of closure. This instantaneous and automatic redirection of the reaction load path at the occurrence of closure provides an effective seal against high pressure aggressive fluids to prevent fluid escaping beyond the valve components whilst, at the same time, allowing effective rotational movement of the valve to occur without providing rotational reliability. This solution allows conflicting load paths through the valve to be resolved, namely through the trunnion during rotation and through the valve seat during sealing.
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This is a continuation of Application No. PCT/NL01/00516, filed Jul. 6, 2001.
FIELD OF THE INVENTION
The present invention relates to a method for removing a plurality of die-cut products from an operating area of a die-cutting apparatus having multiple dies.
BACKGROUND OF THE INVENTION
A die-cutting apparatus having multiple dies cuts a plurality of products out of a base material in a single stroke. For this purpose, the base material is positioned between a top table and a bottom table, on which the dies are arranged. During the die-cutting, the bottom table and the top table are pressed against one another and the dies penetrate into the base material. A stroke consists in the bottom table and the top table being moved towards one another, a die-cutting operation and the bottom table and top table being moved away from one another. The operating area of the die-cutting apparatus is formed by the area where the dies are located.
The base material is fed continuously to the die-cutting apparatus and is shaped as a long strip which slides onwards a certain distance after each die-cutting operation. The strip of base material is supported by conveyor rollers.
After each die-cutting operation, the die-cut products have to be removed from the dies. It is known to use a blowing device for this purpose, which blows the die-cut products off the dies, after which they are collected. It is also known to use ejectors which eject the die-cut products from the dies, after which they are likewise collected. The products are generally removed in a direction which is at right angles to the direction in which the strip of base material slides onwards.
When using multiple dies in a die-cutting apparatus, it may be necessary for the die-cut products to be sorted on the basis of origin. In this case, after the die-cutting, die-cut products. originating from a specific die must not be mixed with die-cut products originating from a different die. If the die-cut products are blown off or ejected from the dies, it is not easy to ensure that this is the case. Moreover, methods of this type for removing the die-cut products from the dies have the drawback that it is not altogether certain whether all products will reach a location which is designated for their collection.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a method for removing a plurality of die-cut products from the operating area of a die-cutting apparatus having multiple dies, in which die-cut products which originate from different dies are not mixed with one another and in which the die-cut products reliably reach the location which is designated for their collection.
This object is achieved by a method which comprises the following steps: substantially simultaneously picking up a plurality of die-cut products at a pick-up point in the operating area; substantially simultaneously moving the die-cut products from the pick-up point to a delivery point outside the operating area; and substantially simultaneously releasing the die-cut products at the delivery point; the die-cut products being fixed with respect to one another at positions which substantially correspond to positions with respect to one another which they adopt at the pick-up point.
The method advantageously comprises the following step: moving the die-cut products from the delivery point to a discharge point located outside the die-cutting apparatus; separate die-cut products being held at different positions.
The method is preferably characterized by moving a transfer member between the pick-up point and the delivery point; bringing the transfer member into an operative state when it is at the pick-up point; and bringing the transfer member into an inoperative state when it is at the delivery point; the transfer member being designed to pick up a plurality of die-cut products at the pick-up point and to release the die-cut products at the delivery point, said transfer member also being designed to fix the die-cut products with respect to one another at positions which substantially correspond to positions with respect to one another which they adopt at the pick-up point.
The die-cut products are always removed from the operating area of the die-cutting apparatus between two die-cutting operations. For this purpose, the transfer member is moved to the pick-up point after each die-cutting operation, the pick-up point being the location where the products are situated after the die-cutting. The transfer member is then activated, so that it is able to pick up the die-cut products. This takes place in such a manner that the die-cut products substantially retain their positions with respect to one another. Then, the transfer member, together with the die-cut products is moved to the delivery point, which is located outside the operating area of the die-cutting apparatus. At the delivery point, the transfer member is deactivated, with the result that the transfer member releases the die-cut products. The positions which the die-cut products adopt with respect to one another at the delivery point substantially correspond to the positions with respect to one another which they adopt at the pick-up point.
The die-cut products are advantageously moved onwards from the delivery point to a discharge point located outside the die-cutting apparatus, where, by way of example, they are collected in receptacles. When the die-cut products are being moved onwards, they are held at different positions, so that products which originate from different dies are not mixed with one another.
If the die-cut products comprise a material which can be attracted by magnetic forces, the transfer member preferably comprises an electrically actuable magnet.
The invention also relates to a die-cutting apparatus having multiple dies and to a removal device for removing a plurality of die-cut products from an operating area of a die-cutting apparatus having multiple dies.
BRIEF DESCRIPTION OF THE DRAWINGS
The method according to the invention and a preferred embodiment of a removal device for use with this method will be explained in more detail in the description which follows with reference to the appended drawing, in which identical reference numerals denote identical or similar components, and in which:
FIG. 1 shows a side view of a removal device according to the invention, in a pick-up position;
FIG. 2 diagrammatically depicts the removal device shown in FIG. 1;
FIG. 3 shows a side view of the removal device according to the invention in a delivery position;
FIG. 4 diagrammatically depicts the removal device shown in FIG. 3 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a removal device for removing a plurality of die-cut products from the operating area of a die-cutting apparatus having multiple dies. The removal device is denoted overall by the reference numeral 1 .
The removal device 1 comprises a transfer member which can be moved in linear fashion and is denoted overall by the reference numeral 10 . The transfer member 10 comprises an extraction head 11 , which in this example is designed as an electrically actuable magnet, and a transfer rod 12 , the extraction head 11 being arranged at a first end 13 of the transfer rod 12 . Over a section of its length, the transfer rod 12 is surrounded by a guide 14 , which is provided, for example, with a ball jacket, by means of which the transfer rod 12 can be supported successfully and can be guided with the minimum possible play. The guide 14 is attached to a holder 15 , for example by means of screws, and the holder in turn, in the installed state, is connected to a bottom table, which can be displaced in a vertical direction, of a die-cutting apparatus. In FIG. 1, the bottom table is shown by means of a dashed line, although only in part, and is denoted overall by reference numeral 50 . The bottom table 50 bears the dies, which are situated in the area which, in FIG. 1, is denoted by reference numeral 51 .
The transfer rod 12 may be designed as a single rod, but with a view to stability is preferably designed as a double rod, in which case the two rods are arranged substantially parallel to one another and-each of the two rods is supported and guided by a ball jacket in the guide 14 .
At its second end 16 , the transfer rod 12 is connected to a first end 17 of a first connecting rod 18 , it being impossible for the transfer rod 12 and the first connecting rod 18 to move with respect to one another. The transfer rod 12 and the first connecting rod 18 could therefore also be designed as a single unit.
At its second end 19 , the first connecting rod 18 is pivotably connected to a first rod head 20 of an adjustment rod 21 . The adjustment rod 21 is shaped in such a manner that its length can be adjusted as desired. In this example, the adjustment rod 21 comprises a connector 22 which is provided with an internal screw thread, two lock nuts 23 , said first rod head 20 and a second rod head 24 . Both rod heads 20 , 24 are provided with a screw thread, one of the two rod heads 20 , 24 and one of the two lock nuts 23 being provided with a left-hand screw thread, and the other of the two rod heads 20 , 24 and the other of the two lock nuts being provided with a right-hand screw thread. The connector 22 is provided with both types of screw thread. The length of the adjustment rod 21 can be varied by turning the connector 22 . The lock nuts 23 are used to lock the connector 22 .
The adjustment rod 21 could also be designed with a fixed length. An adjustable length is advantageous if the removal device 1 is not arranged fixedly at one defined die-cutting apparatus, but rather must be usable for more than one die-cutting apparatus.
The first rod head 20 of the adjustment rod 21 is preferably connected by means of a ball joint to the second end 19 of the first connecting rod 18 , since a ball joint is able to absorb forces acting in different directions. Using a ball joint, any lateral movement of the adjustment rod 21 will be transmitted to a lesser extent to the first connecting rod 18 and the transfer rod 12 than when using a different type of joint.
At the second rod head 24 , the adjustment rod 21 is pivotably connected to a first end 25 of a rocker rod 26 . The rocker rod 26 comprises a first arm 27 and a second arm 28 , which are rigidly connected to one another at a fixed angle at a connecting section 29 . In this example, the first arm 27 and the second arm 28 are situated in the same plane, and the first arm 27 , the second arm 28 and the connecting section 29 are formed as a single unit. The connecting section 29 of the rocker rod 26 is rotatably connected to a fixed column 30 , the axis of rotation extending in a direction which is substantially perpendicular to the plane in which the first arm 27 and the second arm 28 are situated, a bearing preferably being used.
The second rod head 24 of the adjustment rod 21 is preferably connected to the first end 25 of the rocker rod 26 by means of a ball joint.
At its second end 31 , the rocker rod 26 is pivotably connected to a first end 32 of a second connecting rod 33 , which in turn, at its second end 34 , is pivotably connected to a support 35 which, in the installed position, is attached to the bottom table 50 of the die-cutting apparatus.
The removal device 1 comprises discharge chutes, which in FIG. 1 are jointly denoted by reference numeral 40 . In this example, the discharge chutes 40 are attached to the holder 15 . The number of discharge chutes 40 is at least equal to the number of dies used in the die-cutting apparatus, since only products originating from one die may be discharged in any one discharge chute 40 . Each discharge chute 40 comprises a collection end 41 for collecting the die-cut products and extends, for example, to as far as a receptacle (not shown) for collecting the die-cut products or a moving belt (not shown), by means of which the die-cut products are moved onwards.
The discharge chutes 40 may be made from steel U-sections, but may also comprise a different material or be of a different form. The shape of the assembly of discharge chutes 40 should be such, that the die-cut products in different discharge chutes 40 cannot be mixed with one another.
The transfer rod 12 , the first connecting rod 18 , the adjustment rod 21 , the rocker rod 26 and the second connecting rod 33 together form a system of rods which is used to enable accurate control of the movement of the extraction head 11 on the basis of the movement of the bottom table 50 of the die-cutting apparatus. The way in which this rod system operates, as well as the way in which the removal device 1 overall operates, will be described below with reference to FIGS. 1-4, FIGS. 2 and 4 only providing a diagrammatic illustration of the pivot points and the rods.
When the die-cutting apparatus is operating, a number of steps are always passed through each stroke. The starting position is defined as the position in which the bottom table 50 is in its lowermost position. From this position, the bottom table 50 is moved upwards, until it meets a top table (not shown), a base material (not shown) being clamped between the top table and a number of dies (not shown) on the bottom table 50 . During a die-cutting operation, both tables are together moved a short distance upwards, during which movement the pressure exerted on the base material by the dies is increased, until the dies penetrate into the base material and cut products out of the base material. Then, the bottom table 50 together with the dies is moved back downwards, with the die-cut products remaining on the dies. The base material, which is generally in strip form, is moved onwards a certain distance before the next stroke.
The removal device 1 is used to pick up the die-cut products from the dies. During this operation, it is of essential importance for the movement of the removal device 1 to be adapted to the movement of the tables of the die-cutting apparatus in such a manner that the extraction head 11 cannot become jammed between the top table and the dies on the bottom table 50 .
It is also important for the removal device 1 to remove all the die-cut products at each stroke. Therefore, the die-cutting apparatus is generally provided with a security means which signals if a product has remained in place and which is able to stop the movement of the die-cutting apparatus. This security means, which forms part of the die-cutting apparatus, is not shown in the figures.
The movement of the removal device 1 is related to the movement of the bottom table 50 . The structure of the system of rods is such that the extraction head 11 moves towards the tables when the bottom table 50 is moving downwards and moves away from the tables when the bottom table 50 is moving upwards. The diagrammatic representation of the removal device 1 in FIGS. 2 and 4 clearly illustrates this relationship between the movements of the removal device 1 and the bottom table 50 .
FIG. 1 shows the removal device 1 in a pick-up position, i.e. the position in which the extraction head 11 is situated above the die-cut products and is picking them up from the dies. The pick-up position is also diagrammatically illustrated in FIG. 2 . In the pick-up position, the bottom table 50 is situated in a low position and the distance between the top table and the dies is such that the extraction head 11 can be moved between the top table and the dies. When the bottom table 50 is moved upwards, this movement, via the second connecting rod 33 , brings about a rotation of the rocker rod 26 about a rotation point 36 . This rotation of the rocker rod 26 and the associated displacement of the first end 25 of the rocker rod 26 results, via the adjustment rod 21 and the first connecting rod 18 , in a linear displacement of the transfer rod 12 which is directed away from the tables. When the transfer rod 12 has been moved away from the tables by a distance which is such that the extraction head. 11 is situated above the collection ends 41 of the discharge chutes 40 , the removal device 1 is in a release position. The release position is shown in FIGS. 3 and 4.
In this example, the extraction head 11 moves in a direction which is substantially at right angles to the direction in which the dies move. This is advantageous with a view to utilizing the limited free space which is available in the immediate vicinity of a die-cutting apparatus.
In the pick-up position, the extraction head 11 is situated above the die-cut products and is activated in order to pick up the products. In this example, in which the extraction head 11 is an electrically actuable magnet, a magnetic field is generated and, under the influence of the said magnetic field, the products come to bear against the extraction head 11 . During the picking-up operation, the die-cut products substantially retain their positions with respect to one another.
During the movement from the pick-up position to the release position, the magnet remains in an operative state. In the release position, the magnet is brought into an inoperative state, so that the die-cut products drop off the magnet. In the release position, the magnet is situated above the collection ends 41 of the discharge chutes 40 , so that die-cut products are collected by the said collection ends 41 .
The magnet can be actuated by means of activating means which are already being used to activate the die-cutting apparatus. Another possibility is for the magnet to be actuated with the aid of a switch which is arranged in the guide 14 and is actuated by the transfer rod 12 .
The discharge chutes 40 can be omitted if the die-cut products, after they have been released by the extraction head 11 , can remain at the location where they are collected and do not need to be moved any further.
In this example, the removal device comprises a system of rods which is secured at a fixed rotation point 36 and converts a movement of the dies into a movement of the extraction head 11 . As a result, a movement of the extraction head 11 is activated mechanically on the basis of a movement of the dies. The activation could also be produced by electronic means, for example. However, mechanical activation is advantageous since activation of this type is relatively unsusceptible to faults. Moreover, a removal device in which the activation takes place by mechanical means can easily be used for different types of die-cutting apparatus, irrespective of the movement characteristics of the dies.
It will be clear to the person skilled in the art that the scope of the present invention is not limited to the embodiment discussed above, but rather numerous amendments and modifications to this embodiment are possible without departing from the scope of the invention as defined in the appended claims.
For example, the extraction head 11 could be provided with pneumatically actuable suction cups, which are known per se, for picking up the die-cut products and releasing them again, instead of the electrically actuable magnet described above.
Another possibility is for the removal device 1 not to be equipped with a system of rods, but rather with a cam system which provides direct activation of the movement of the extraction head 11 on the basis of the movement of the bottom table 50 of the die-cutting apparatus.
The movement of the extraction head 11 has to be accurately matched to the movement of the tables of a die-cutting apparatus. In the above text, the removal device 1 has been described in connection with a die-cutting apparatus in which the bottom table 50 undergoes most of the displacement and the top table only undergoes a slight displacement during the die-cutting operation, movements of the removal device 1 being related to movements of the bottom table 50 . The removal device 1 can also be used for other types of die-cutting apparatus, for example die-cutting apparatus in which the top table undergoes most of the movement. In die-cutting apparatus of this type, the removal device 1 may be installed in such a manner that movements of the removal device 1 are related to movements of the top table.
In the above text, the removal device 1 has been described as mounted on a die-cutting apparatus, but this does not detract from the fact that the removal device 1 in the unmounted state is also covered by the scope of the invention.
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The invention describes a method and an apparatus removing a plurality of die-cut products from an operating area of a die-cutting apparatus having multiple dies. The die-cut products are simultaneously picked up at a pick-up point in the operating area. Then they are simultaneously moved to a delivery point outside the operating area. At the delivery point, the die-cut products are released simultaneously. The operations of picking up moving and releasing are carried out in such a manner that the die-cut products at the delivery point are situated at substantially at the same position with respect to one another as those which they adopt at the pick-up point.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for measuring the weight of fluids, particularly for determining the weight of drilling, completion, and workover fluids used in drilling, completion, and workover operations in the context of oil well drilling operations.
2. Background of the Invention
The present invention relates to an improved apparatus for accurately determining the unit weight of drilling fluid being pumped into a well during drilling operations and for determining the weight of the drilling fluid returning from the well during drilling operations. Also, present invention can be used to similarily determine the unit weight of drilling fluid being utilized in completion and workover operations within the context of oil well drilling operations.
During the drilling of a well in the quest for hydrocarbons using the rotary method of drilling, it is necessary to pump or circulate a drilling fluid, known in the art as "drilling mud", downwardly through the drill pipe to which the drill bit is attached and outwardly through the drill bit into the annulus formed by the drill pipe and the wall of the well bore, for return upwardly through the annulus to the surface.
A container known as a suction tank contains the drilling fluid for pumping through the drill pipe into the well. Circulating drilling mud exits from the drill bit returning to the surface through the annulus between the drill pipe and the wall of the well bore and out into a shaker box where the cuttings which are drilled up are separated from the returning drilling fluid. Drilling fluid then flows from the shaker box via a settling tank back to the suction tank for return to the well. Drilling mud is essential to a well drilling operation as it serves to carry away the cuttings from the drill bit to facilitate drilling and act as a medium for transporting the cuttings from the drill bit area out of the well bore to be separated from the mud by means of the shaker box or settled out in a mud pit at the top of the well prior to recirculation. The primary function of the drilling mud is to act as a stopper in the well by exerting hydrostatic pressure on the bottom of the well according to the specific weight of the drilling mud thereabove to balance or overcome the formation pressure in order to prevent blowouts. The pressure of the formation adjacent to the drill bit, or bottom-hole pressure, must also be taken into consideration because this pressure must be sufficient to sustain the hydrostatic pressure of the mud in order to prevent loss of circulation, and loss of the mud as it escapes into the formation due to the pressure exerted by the mud column being substantially greater than the formation pressure itself. It is therefore essential that the pressure of the well bore, i.e., formation pressure, and the hydrostatic pressure of the drilling mud be maintained near balanced condition. The drilling mud also acts as a sealing means upon the well bore by caking on the surface of the bore to seal the bore and prevent the drilling mud from flowing out into the formation material.
It is necessary that the drilling mud be of sufficient weight to balance against the force of any upwardly acting hydrostatic pressure such as the pressure of gas, water, or oil which may be exposed in drilling and, at the same time, the drilling mud should not become so heavy that it enters the formation causing a loss of circulation. As conditions vary in the course of drilling, the weight of the drilling mud has to be altered to meet these changing conditions. For instance, if the gas sand is penetrated, the gas of the bore space will become a part of the drilling fluid. As the fluids are pumped out of the hole the gas expands, with the consequence that the mud flows out of the hole at a faster rate than it enters and the mud weight becomes considerably lighter. Such a condition must be detected immedately as remedial action may be necessary by the addition of weighted material to the drilling fluid, as otherwise the fluid might not contain the forces of the formation pressures reacting upwardly thereagainst with the consequence that a blowout may occur.
The use of excessive mud weight to provide a large factor of safety against blowouts has been previously used as a standard drilling procedure. Of course, as mentioned previously, such an overbalance may result in a loss of circulation where the formation pressures are incapable of withstanding the over-balanced hydrostatic pressures of the drilling mud. For reasons of economy, a new drilling concept of balanced pressure drilling was adopted and it became essential that continual accurate measurement of the mud weight be maintained at all times during the drilling operation, since less dense drilling mud allows faster drilling with less wear on the equipment. Since balanced pressure drilling reduced the factor of safety against blowouts, which resulted from excess mud weight, it becomes imperative that accurate and continuous mud weights into and out of the well be logged since the best evaluation of bottom hole conditions is to continuously determine the absence or to accurately measure the volume of gas entering the hole. Such a determination will provide information essential to maintaining minimal mud weight to balance the bottom hole pressures and prevent blowout conditions.
It is recognized that a continuous accurate measure of the amount of gas entering the formation is valuable information for properly balancing the well during the drilling operation. Drilling for hydrocarbons is hazardous as is evident by frequent blowouts which cause considerable air and water pollution and general ecological damage, which entails considerable expense and delays in the oil rig operation, in addition to causing periodically serious injuries. Blowouts result from the unknown relationship between formation pressures and the weight of the drilling mud which is predetermined for formation pressure containment and penetration control. The mud weight determinations are initially based on historical data for a particular formation which, of course, is only an approximation and it is therefore essential that accurate and continuous determinations be made of the drilling fluid exiting from a well since the mud weight out of the well is a reflection of the bottom hole pressure of the formation being drilled up.
The present invention is an improved apparatus for accurately measuring the weight of the drilling mud being pumped into the well and accurately determining the weight of the mud being pumped out of the well and continuously logging the information on a time chart so that an accurate determination can be made as to changes in the mud weight resulting from bottom hole conditions. The determination of mud weight in and mud weight out require two measurements, one of which is made in the suction tank which contains the drilling fluid being pumped into the well and the other measurement is made in the shaker box which contains the drilling fluid returning from the well. There have been some devices of the prior art which have attempted to make this accurate determination of the weight of the drilling mud, some of these devices of the prior art consisting of a differential pressure densiometer in which the weight of the fluid is measured by the difference in pressure between two pneumatic tubes submerged in the drilling fluid, both tubes having independently controlled air supplies, wherein the pressure of the air in each tube is regulated to the same rate and the flow is metered so that both tubes have the same volume of air at equal pressure flowing into the mud being measured, the ends of the tubes being positioned at exactly 8.35 inches apart, which represents the weight of water in pounds per gallons. Therefore, when the weight of the drilling fluid is increased or decreased, the pressure differential at the ends of the submerged tubes will increase or decrease by one inch of water pressure for each pound per gallon increase or decrease in the weight of the drilling fluid. This permits direct reading in pounds per gallon on a pressure differential recording device. However, these attempts to use pressure differential pneumatic tubes for measuring the weight of the fluid have been highly inaccurate and infeasible in actual practice.
It is the primary object of the present invention to provide an apparatus which accurately and feasibly measures the weight of the drilling mud being pumped into the well and out of the well and for continuously logging the information so that an accurate determination can be made of the changes in the mud weight resulting from bottom hole conditions.
The present invention features a single air pressure sensor tube threaded on top for mating with a connector fitting which is connected to a source of air supply and a remote pressure recorder and pressure gauge. A preferably adjustable float is mounted around the sensor tube to ensure that the sensor tube remains submerged in the fluid within the suction tank or the shaker box at a certain depth, regardless of variations in the level of the drilling fluid in the tank. A pressure gauge which is connected to the connector fitting at the top of the sensor tube above the connection of the air supply hose to the connection fitting at the top of the pressure sensor tube, measures the pressure sensed by the sensor tube in inches of water, preferably, and the remote pressure recorder connected adjacent thereto continuously records the measurements continuously generated by the pressure gauge. The air sensor tube has an open-ended bell bottom with a check valve mounted therein to prevent plugging of the sensor tube in the event the air supply is momentarily lost. The weight of fresh water is 8.34 pounds per gallon. Therefore, as in the preferred embodiment, if the sensor tube is submerged 8.34 inches in fresh water, the air pressure required to maintain air flow through the sensor tube will be 8.34 inches of water as seen on the pressure gauge and recorder. For the purposes of the present invention, this pressure is read as 8.34 pounds per gallon. In operation, the sensor tube is fixedly submersed in the drilling fluid to have its density determined, regardless of the amount of drilling fluid in the suction tank or shaker box, because of the float being fixed 8.34 inches above the bell-bottom. Further, the sensor tube is maintained in a substantially vertical position relative to the surface of the drilling fluid in the suction tank or shaker box, by means of a plurality of pulley wheels rotatably mounted on a plate which is fixably attached to a C-clamp which is securely mounted to the suction tank or shaker box, preferably, so that the sensor tube is allowed to pass between the pulley wheels when the sensor tube is vertical relative to the surface of the drilling fluid to have its density determined, the pulley wheels thereby maintaining the sensor tube in this vertical position relative to the surface of the drilling fluid. This dispositon of the sensor tube in a vertical position relative to the surface of the drilling fluid ensures an accurate reading of the density of the drilling fluid to have its density determined. Now, if the sensor tube is submersed at this 8.34 inches, but in 18.0 pounds per gallon drilling fluid, the amount of air pressure required to maintain air flow will read 18 inches of water on the pressure gauge and recorder. This pressure is interpreted as 18.0 pounds per gallon mud weight.
Because of the use of one sensor tube rather than two sensor tubes, the apparatus of the present invention has proven to achieve more accurate readings and is simpler to implement.
Many other objects and advantages of the present invention will become apparent from the detailed description of the preferred embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic, sectional view of a drilling rig including pumps, well bore, suction tank and shaker box with the present invention included therein.
FIG. 2 is a partially schematic, cross-sectional, elevational view of the present invention mounted to the suction tank.
FIG. 3 is a cross-sectional, frontal view of the vertical aligning means of the present invention for maintaining the sensor tube and extension tube in a substantially vertical axis relative to the surface of the drilling fluid.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As can be seen from FIG. 1, a derrick 2 has been illustrated as mounted over the well bore 3 which is being drilled by the drill bit 4 connected to drill pipe 5 which is in turn connected to a swivel 6, a travelling block 7 and the hoisting lines 8. This drill pipe is rotated by rotary table 9 which receives its power from a suitable source. The well bore 3 is being filled with a drilling mud 10 which is forced downwardly by pump 12 through a hose 14 and into the upper end of the drill pipe 5. The mud is picked up by the pump from the suction tank 21 via conduit 22 shown partly in schematic form in FIG. 1. Well casing 11 exits from the bore 3 in known manner and has a blow out preventor 23 mounted on top of said casing with a bell nipple 24 mounted on top of the blow out preventor 23. The drilling mud circulates upwardly in the casing within the annular space between the casing 11 and the drill pipe 5 and will rise to a level such as 15 in the casing depending upon the rate of circulation which is being maintained by the pump 12. The discharge flow line 16 allows the drilling mud to discharge from the well bore and into the shaker box 17. The drilling mud exits from the shaker box over a vibrating screen not shown and into settling tank 25. The drilling fluid then travels from the settling tank 25 via conduit 26 and into the suction tank 21 to be recycled into the well via conduit 22.
As shown in FIG. 2, there can be seen the pneumatic fluid densiometer of the present invention, as indicated generally by the numeral 1. The pneumatic fluid densiometer of the present invention comprises a pneumatic tube 32 submersed 8.34 inches in the drilling fluid contained by either the shaker box 17 or the suction tank 21, the pneumatic tube 32, or sensor tube 32 being threadedly connected near its top end, preferably (although it can be fixably attached), to a generally spherical air-tight floating chamber 43, or float 43, float 43 being maintained at a distance of 8.34 inches from the bottom end of sensor tube 32 by means of collar 33, thereby ensuring that sensor tube 32 remains constantly sumbersed 8.34 inches in the drilling fluid to have its density determined, for reasons which will hereinafter be seen. Sensor tube 32 comprises an open-ended, generally bell-shaped bottom 44, which can be either threadedly connected or fixably attached to the bottom end of sensor tube 32. The top end of sensor tube 32 is either threadedly or fixably attached to a longitudinally elongated extension tube 46. In the preferred embodiment, extension tube 46 is threadedly connected to the top end of sensor tube 32 by means of connector collar 47. In the preferred embodiment, a plurality of pulley wheels 48 are rotatably mounted to a plate 49, the distance between the pulley wheels 48 being approximately the same as the outside diameter of the sensor tube 32, thereby positioning the annular grooves 50 of the pulley wheels 48 for receiving and guiding the extension tube 46, as will hereinafter be seen. As disclosed in FIG. 3, plate 49 comprises three pulley wheels 48 arranged in a triangular configuration. Plate 49 is connected by any suitable means, for example pivot rod 54, to a C-clamp 55 which is securably mounted to the side of the shaker box 17 or the suction tank 21. Pivot rod 54 is a generally L-shaped rod which is preferably fixably attached to C-clamp 55 on one end and preferably fixably attached to plate 49 on its other end, so that the extension tube 46 is permitted to pass through the space between pulley wheels 48, so that the annular grooves 50 of pulley wheels 48 guide extension tube 46, and therefore sensor tube 32, along a substantially vertical axis relative to the surface of the drilling fluid to have its density determined. A connector nipple 60, adapted for receiving an air supply conduit 62 is threadedly connected, preferably, to the top end of extension tube 46. Air supply conduit 62 is connected on one end to connector nipple 60 and on its other end to a source of pressurized air, which can be provided by the drilling rig 2 or a small air pump (not shown). An air regulator 64 is connected to the air supply conduit 62 for regulating the air entering the extension tube 46 and the sensor tube 32 via air supply conduit 62 at a pressure of approximately 3 p.s.i. The low pressure is used to maintain a constant flow of air through the extension tube 46 and the sensor tube 32 with a minimum amount of friction and the flow is maintained constant in each tube 46, 32 by means of flow meters 35 which are serially mounted to the air supply conduit 62 between air regulator 64 and the source of compressed air (not shown). Another conduit 66, is connected to air supply conduit 62 at some point above connector nipple 60, so that conduit 66 fluidly communicates with conduit 62. Conduit 66 is connected on its other end to a remote pressure recorder 68 and a pressure gauge 70 which are calibrated in inches of water, which is readily converted to pounds per gallon and/or pounds per cubic foot. Since the sensor 32 is preferably submersed 8.34 inches in the fluid to have its density determined, if the fluid is water, then the amount of air pressure required to maintain air flow in the sensor tube 32 and the extension tube 46 will read 8.34 in inches of water on the pressure gauge 70 and the pressure recorder 68. Since the weight of water is 8.34 pounds per gallons, then this 8.34 inches of water figure can be directly read as 8.34 pounds per gallon fluid density. Now, if the sensor tube 32 is submersed 8.34 inches in 18.0 pounds per gallon density drilling fluid, the amount of air pressure required to maintain air flow will be 18 inches of water as read on the pressure gauge 70 and the pressure recorder 68, and this pressure can be directly interpreted as 18.0 pounds per gallon mud weight.
The operation of the device is as follows:
1. The C-clamp 55 is securably mounted to the side of either the shaker box 17 or the suction tank 21, wherein the drilling fluid is contained, thereby substantially aligning the longitudinal axis of the space between the pulley wheels 48 with the vertical axis of the imaginary plane perpendicular to the surface of the drilling fluid to have its density determined;
2. The extension tube 46 is inserted in the space between the pulley wheels 48 so as to ride in the annular grooves 50 of the pulley wheels 48, the float 43 floating on the surface of the drilling fluid in the tank 21 or the shaker box 17, so that the sensor tube 32 is submersed at an 8.34 inch depth in the drilling fluid, the pulley wheels 48 ensuring that the extension tube 46 and the sensor tube 32 remain in a substantially vertical axis relative to the surface of the drilling fluid to have its density determined;
3. Compressed air is fed from the source of compressed air (not shown) and is regulated to a pressure of approximately 3 p.s.i. by means of air regulator 64 before flowing through air supply conduit 62 and through extension tube 46 into sensor tube 32; low pressure is used to maintain a constant flow of air through the tubes 46, 32 with a minimum amount of friction and the flow is maintained constant in each tube 46, 32 by means of flow meters 35;
4. If the drilling fluid is water, an air pressure of 8 inches of water will be necessary to create an equilibrium condition between the air in the sensor tube 32 and the drilling fluid to have its density determined, and this equilibrium condition can be observed as bubbles at the surface of the drilling fluid;
5. Because drilling fluid is generally denser than water, a greater air pressure, in inches of water, as readable on the pressure gauge 70, will be required in order to achieve an equilibrium condition between the air in the sensor tube 32 and the drilling fluid in the shaker box 17 or the suction tank 21; when the operator (not shown) of the device of the present invention observes bubbles at the surface of the drilling fluid, then this signifies that an equilibrium condition has occurred between the air in the sensor tube 32 and the drilling fluid to have its density determined; at the time that this equilibrium condition occurs, the density of the drilling fluid can be determined by reading the pressure gauge 70, and because of the manner in which the pressure gauge 70 is calibrated, this reading in inches of water is directly convertible into pounds per gallon, which is indicative of the density of the drilling fluid; remote pressure recorder 68 continuously records these readings.
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A device for determining the density of drilling mud by having one end of a float carried tube 8.34 inches below the surface of the mud. A constant flow of air is supplied to the other end of the tube. The pressure of the air entering the tube, when air bubbles appear at the surface of the mud, is indicative of the density. The tube is maintained vertical by passing the tube through the grooves of a group of pulley wheels.
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This is a division of application Ser. No. 08/416,625 filed Apr. 4, 1995 now U.S. Pat. No. 5,614,919.
TECHNICAL FIELD OF THE INVENTION
This invention relates to a diamond matrix metallic mesh structure which serves as a near perfect absorber of RF energy to suppress the side lobes produced from a phased array radar system, and to a method for fabricating the metallic mesh structure.
BACKGROUND OF THE INVENTION
Phased array radars are in use in many military and commercial applications. The transmit function of such phased arrays typically results in generation of side lobe radiation. There is a need to suppress such radiation, since it can occur over large angles and at high energy, allowing energy radars to triangulate and fix their fire control radars onto the radiator. Moreover, elimination of side lobes results in main beams having greater resolution, permitting target profiles/cross-sections to be calculated more efficiently and the system to refresh more quickly.
SUMMARY OF THE INVENTION
A structure is described for reflecting/absorbing electromagnetic radiation, comprising a wire mesh structure emulating a diamond lattice bond link structure between carbon atoms of a diamond lattice. The diamond wire lattice structure is useful for absorbing side lobe energy from a phased array radiating system.
A method for described for fabricating the wire mesh structure, comprising the following steps:
fabricating a plurality of unit structure wire elements, each defining a zig-zag pattern of adjacent link portions, adjacent portions defining unit structure vertices;
interconnecting said elements in adjacent tiers of unit structures, each tier defined by a set of spaced aligned unit structures, and wherein the structures of one tier are disposed transversely to the structures of adjacent tiers, and structures of one tier are electrically and mechanically interconnected to structures of adjacent tiers at said unit structure vertices.
The adjacent link portions of each unit structure preferably define an included angle of 108.47 degrees.
A preferred method for fabricating the unit structure elements comprises:
providing a set of first and second forms, said forms defining complementary zig-zag surfaces in the outline of said unit structure elements;
disposing said forms in an aligned, spaced relationship with said respective zig-zag surfaces facing each other;
disposing a straight section of wire between said surfaces; and
forcing said forms toward each other to compress said wire between said zig-zag surfaces, bending said wire to assume the shape of said zig-zag surfaces.
BRIEF DESCRIPTION OF THE DRAWING
These and other features and advantages of the present invention will become more apparent from the following detailed description of an exemplary embodiment thereof, as illustrated in the accompanying drawings, in which:
FIG. 1 is a simplified side view of an antenna array employing a wire diamond lattice structure in accordance with the invention for side lobe suppression.
FIG. 2 is a schematic diagram illustrating a basic element of a diamond lattice structure.
FIGS. 3A-3E are simplified diagrams illustrating the connection of a plurality of building block elements into a unit cube structure comprising a wire lattice structure in accordance with the invention. FIG. 3A shows one half of diamond lattice unit cube building block of a diamond structure. FIG. 3B is similar to FIG. 3A but with the size of the atom representations reduced in size. FIG. 3C illustrates the unit cube structure with one unit wire structure in place. FIG. 3D shows two additional unit wire structures arranged in alignment with the first unit wire structure. FIG. 3E shows fourth and fifth unit wire structures disposed transversely to the first three unit wire structures, with intersections between wire segment portions disposed at the center of carbon atoms in the unit cube.
FIG. 4 illustrates complementary forms employed to compress a straight metal wire between complementary surfaces to form a wire unit structure element.
FIG. 5 shows the two forms of FIG. 4 in compression against a metal wire to bend the wire into the zig-zag shape of the unit structure element.
FIG. 6 shows an exemplary wire unit structure in isolation.
FIG. 7 illustrates an exemplary initial step in a fabrication process to fabricate a diamond wire lattice structure embodying the invention, wherein tines of a fork structure position unit structure elements in an aligned relationship for attachment to a second tier of unit structures.
FIG. 8 shows the resulting partial assembly resulting from the assembly step of FIG. 7.
FIG. 9 shows a further step in the assembly of the wire lattice structure, wherein a third tier of unit structure elements has been added to the partial assembly of FIG. 7.
FIG. 10 shows a further step in the assembly of the wire lattice structure, wherein a fourth tier of unit structure elements has been added to the partial assembly of FIG. 8, resulting in a basic interlocking cube structure of the diamond lattice structure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
This invention is directed to a metal mesh matrix that has the structure of the bond segments joining the carbon atoms in the diamond structure. This structure will absorb and/or suppress the side lobe radiation that is generated by the radar transmitter in an active radar system. This radiation needs to be suppressed since it radiates at large angles and high energy, allowing the enemy radars to triangulate and fix their fire control systems onto this radiator. Moreover, the invention provides a technique to make a multi-functional aperture stealthy, since the sidelobes are suppressed. Since the side lobes are eliminated, the main beam has a greater resolution, and better target profiles/cross-sections can be calculated more efficiently and system refreshes more rapidly.
FIG. 1 is a simplified partially exploded schematic illustration of an exemplary embodiment of a phased array antenna 50 employing this invention. The system 50 includes a ground plane 60, which may be fabricated of a photonic band gap material as described in commonly assigned, co-pending application serial number 08/416,626, filed Apr. 04,1995, now U.S. Pat. No. 5,600,342, entitled "METHOD FOR PRODUCING A DIAMOND LATTICE VOID STRUCTURE FOR WIDEBAND ANTENNA SYSTEM," Attorney Docket PD 93240. Alternatively the ground plane can be a conventional metallic surface. The antenna includes an array of radiating elements 70 fabricated on a dielectric substrate 72, and having a periodicity D. In accordance with the invention, a side lobe energy absorbing/reflecting structure 80 extends above the plane of the radiating elements 70. The structure 80 is a diamond wire lattice structure.
In this exemplary embodiment of FIG. 1, the radiating elements 70 are stub elements comprising a stub element array. Five elements are shown in FIG. 1, of a three by five element array. These stub elements are fabricated on the substrate layer 72 fabricated, e.g., of Duroid (TM).
The ground plane 60 below the radiators 70 reflects all of the incident radiated power from the radiators. The function of the structure 80 is to reflect/absorb the undesirable side lobe energy, so that the undesirable sidelobe energy is essentially trapped and prevented from radiating to free space, while allowing the main beam energy to pass through the structure.
For the case in which the ground plane 60 is a photonic band gap material, there is no particular spacing requirement for a given space dimension between the radiating plane of the radiating elements 70 and the ground plane 60, except for some irregularity appearing from surface waves. For the case in which the ground plane is a conventional metallic plane, then the distance between the radiating plane and the ground plane should be one quarter wavelength of radiation for monochromatic radiation.
The ideal spacing between the radiating plane of the radiating elements 70 and the side lobe energy absorbing structure 80 is zero, although there is no electrical contact between the wires comprising the structure 80 and the radiators 70.
FIG. 1 also illustrates a simple radar emission from the antenna array comprising the radiating elements 70, with two sidelobes S1 and S2 surrounding a main beam B, and radiating into a metal mesh matrix. The Bragg reflected wave condition is given by
sinθ=λ/2d
where λ0 is the radiation wavelength, d is the unit lattice dimension inside the metal mesh matrix, and θ is the angle of side lobe emission. Hence, for a specific sidelobe angle, say θ i , and wavelength of emission, the lattice dimension d i for the metal mesh is specified. Given that these values satisfy the Bragg reflected wave condition, no sidelobe radiation at angle θ i is transmitted through the metal mesh. Since the metal mesh is already fabricated to satisfy the sidelobe suppression at the sidelobe angle θ i , the main lobe B, at θ=90 degrees, does not satisfy the Bragg condition. Thus, the main lobe B is transmitted through the metal mesh structure 80, albeit with some losses incurred.
The sidelobes S1 and S2 will appear at an angle θ=λ/D, where D is the period of the antenna array. Hence the lattice dimension d in the metal mesh 80 is related to the array periodicity by D=2d for a specific radiation wavelength.
The basic building blocks of the metal mesh diamond structure for the wire absorber 80 emulate the bond lines that lie parallel/perpendicular to the {1,1,0} planes of the diamond lattice. These bond lines form a zig-zag structure 20 as shown in FIG. 2, wherein the bond lines 24 interconnect between carbon atoms 22. As shown in FIG. 2, angle A is 36.26 degrees, and angle B, the included angle formed between adjacent links 24, is 109.47 degrees. The outline of the zig-zag structure 20 will form the basic unit structure employed in fabricating an embodiment of the wire mesh lattice structure 80.
In an exemplary embodiment, the basic unit zig-zag structure 100 is formed from a straight length of metal wire 110 of the appropriate gauge or diameter chosen for the desired frequency of operation. The wire gauge or diameter is not critical, and is typically selected to produce a needed structural strength. In one exemplary embodiment, the wire gauge is selected to be about 1/10 (or smaller) of the unit diamond lattice dimension d (FIG. 3B).
FIGS. 3A-3E illustrate the connection of a plurality of the unit structures 100 into the structure 80. FIG. 3A shows one half of diamond lattice unit cube building block 10. The spherical balls 22 represent one half of the carbon atoms in the diamond cube structure. Vertical and horizontal sticks 14 and 16 indicate the sides and bottom of the unit cube. FIG. 3B is similar to FIG. 3A but with the size of the atoms reduced to show the side and bottom sticks 14 and 16 more clearly.
FIGS. 3C-3E illustrate the buildup of a wire lattice structure in accordance with the invention. FIG. 3C illustrates the unit cube structure 10 with one unit wire structure 100B in place, essentially running diagonally across the unit cube structure, with intersections between wire segment portions disposed at the center of carbon atoms in the unit cube. Next, at FIG. 3D, two additional unit wire structures 100A and 100C are arranged in alignment with the first unit wire structure 100B. These second and third unit wire structures will interconnect this unit cube structure 10 to adjacent unit cube structures. FIG. 3E shows fourth and fifth unit wire structures 120A and 120B disposed transversely to the first three unit wire structures 100A-100C, with intersections between wire segment portions disposed at the center of carbon atoms in the unit cube. To complete the unit cube structure 10, third and fourth tiers or courses of wire structures would be added, in the same manner.
To produce the basic unit zig-zag wire structure according to an exemplary fabrication method, complementary forms 102 and 104 are constructed as shown in FIG. 4. As shown in FIG. 4, the metal wire 110 is positioned between the complementary surfaces of the forms 102 and 104. When the straight length of metal wire 110 is compressed between the forms 102 and 104, as shown in FIG. 5, the straight wire is transformed into the required shape of the basic unit structure 100.
The basic unit structure 100 is shown in FIG. 6. As in the diamond bond link structure of FIG. 2, the adjacent "links" of the structure 100, i.e., the adjacent straight segments 112 of the wire forming the structure, meet at an included angle of 109.47 degrees. Several of the unit structures 100 can be made simultaneously using the forms 102 and 104. Moreover, only this set of forms 102 and 104 is required to produce the complete diamond metal mesh structure 80.
Once the basic unit structures 100 have been made up as shown in FIG. 6, many of the structures are assembled to form the wire mesh structure 80. Referring to FIG. 7, a metal fork structure 130 is employed to hold a first tier of the unit structures in place for assembly with a second tier of unit structures. The fork structure 130 includes a number of fork tines 132, 134, 136 and 138. The fork structure may include many more tines; only four tines are shown for simplicity in FIG. 7. The tines are made from flat strips of metal, and act as gauge blocks to hold the first tier of metal wire unit structures 100A, 100B and 100C in the exact position required for connection of the first tier to a second tier of unit structures 120A, 120B and 120C. The second tier of unit structures 120A-120C is rotated 90 degrees relative to the first tier of structures 100A-100C. The first and second tiers are connected both electrically and mechanically at upper vertices 114 of the unit structures. The connection at the vertices is by soldering, brazing, laser welding or electroforming, or by other known method of connecting metal structures electrically and mechanically. Once the first and second tiers are connected, the tines of the fork are removed from the resulting structure, and the diamond structure begins to emerge, as shown in FIG. 8.
Referring now to FIG. 9, a third tier of unit structures 130A-130D is added to the partial assembly of FIG. 8. The structures of the third tier are attached at the lower set of vertices 116 of the first tier structures 100A-100C. The third tier unit structures are also oriented at 90 degrees relative to the first tier structures.
In the next fabrication step, the result of which is shown in FIG. 10, a fourth tier of unit structures is added to the partial assembly of FIG. 9. The fourth tier structures 140A-140C are oriented parallel to the first tier structures, and orthogonally to the second and third tier structures. The fourth tier structures are attached at their respective lower vertices to corresponding upper vertices 116 of the second tier unit structures 120A-120C. The assembly shown in FIG. 10 illustrates the basic interlocking cube structure of the diamond lattice structure.
If the lattice dimension d of the diamond cube is approximately 1.0 centimeter, then the distances of the unit structures 10 become the following for a center frequency of approximately 14.7 GHz.
L1=0.71 cm,
L2=0.43 cm,
L3=0.25 cm, and
L4=0.25 cm.
where L1, L2, L3 and L4 are as shown in FIG. 2 and FIG. 3. All of these dimensions are such that machining of the forms and performing the interconnecting of the unit structures are all very manageable. Table I below relates the dimensions of the unit shape 100 to the center frequency of the radar system.
TABLE I______________________________________CenterL1 (cm) d (cm) Freq (GHz) Bandpass (GHZ)______________________________________.7068 1.02 14.7 6.761.1238 1.59 9.4 4.321.795 2.54 5.9 2.712.8625 4.05 3.7 1.74.5942 6.5 2.3 1.06______________________________________
The values given in Table I are derived in the following manner. The center frequency f is determined by the dimension d of the lattice through the relationship
f=c/2d
where c is the speed of light. The dimension d is also equal to λ/2, where λ is the wavelength at the center frequency f. The bandpass is determined from published data on diamond wire lattices, which gives an optimum bandpass as a function of the lattice spacing and ratio of air to metal. See, e.g., K.M. Ho, C. T. Chan and C. M. Soukoulis, "Existence of photonic bandgap in periodic dielectric structures," Physical Review Letters, 65, 3152 (1990).
The wire lattice structure 80 should be oriented such that the planes of symmetry of the lattice structure face the radiating elements 70, i.e., the Bragg condition for reflected waves. The planes of symmetry are indicated as planes 82 in FIG. 1, and are spaced apart by the unit lattice dimension d. The planes are defined by the bottom and top planes of the unit cube structures 10 which make up the wire lattice structure 80.
It is understood that the above-described embodiments are merely illustrative of the possible specific embodiments which may represent principles of the present invention. Other arrangements may readily be devised in accordance with these principles by those skilled in the art without departing from the scope and spirit of the invention.
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A diamond matrix metallic mesh suppresses RF energy, and particularly side lobe energy, in a phased array antenna, while passing main beam energy. The metal mesh emulates the structure of the bond segments joining the carbon atoms in a diamond structure. The wire diamond lattice structure is placed above an array of radiating elements to absorb side lobe energy. The wire lattice structure is fabricated through use of complementary forms which compress a wire into a required unit shape. Many unit shaped wires are placed in a form which hold the wires in the proper position. Other unit shaped wires are rotated 90 degrees and attached in place to the held wires. Additional unit shaped wires are added to form the basic interlocking cube structure of the diamond lattice.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 10/698,095, filed Oct. 31, 2003, and entitled “Electronic Valve Reader”, which is now U.S. Pat. No. 7,334,582, issued Feb. 26, 2008; the entirety of which is incorporated herein by reference.
FIELD
The invention relates to medical devices and, more particularly, to magnetic reader-based indicator tools.
BACKGROUND
Magnetic-based indicator tools are used to determine a setting of an implantable medical device. The implantable medical device may include a fluid flow control valve that controls the pressure of cerebral spinal fluid (CSF) in a patient's brain. Excessive accumulation of cerebral spinal fluid (CSF), due to hydrocephalus or other causes, manifests itself as increased pressure within the brain. Relieving the CSF pressure is therapeutically beneficial and is usually done by using a fluid flow control valve to drain CSF from ventricles in the brain.
The implantable medical device may include a target in the form of a magnet. The magnet allows a tool set to determine the setting of the medical device and change the setting without removing the subcutaneously implanted device. The tool set typically includes a locator tool to determine the orientation of the medical device, the magnetic-based indicator tool to determine the setting of the implantable medical device by using a compass, and an adjustment tool to change the setting of the medical device by using another magnet. The tool set works by using magnetic coupling between the magnet on the implantable medical device and each of the indicator tool compass and the adjustment tool magnet.
The compass-based indicator tool relies on an interaction between the magnet on the medical device and the compass that is strong enough to determine the position of the magnet even through a patient's scalp. The magnet-compass interaction must also be resistant to external magnetic fields, especially from the Earth. The compass will drift toward aligning with the Earth's magnetic field if the pull of the magnet in the implanted medical device is not strong enough. The deflection angle increases as the distance between the magnet and the compass increases, and may lead to inaccurate device setting indications.
Alternatively, magnetic based location tools have been developed to determine the three-dimensional location and orientation of magnetic devices within implanted medical devices, such as medical tubes and catheters. These alternate location systems typically do not relate to the rotatable orientation of magnetic devices that are part of implantable valve devices.
U.S. Published Patent Application No. 2002/0022793 to Bertrand et al. discloses a compass-based indicator for assessing the position of a fluid flow valve within an implanted device. The fluid flow valve described by Bertrand et al. may be used for controlling the flow of cerebral spinal fluid (CSF) in a patient with hydrocephalus. This compass-based indicator is used in combination with an implantable flow control device disclosed within U.S. Pat. No. 5,637,083 to Bertrand et al. U.S. Pat. No. 5,879,297 and U.S. Pat. No. 6,129,668 to Haynor et al. discloses an electronic device to determine the location and orientation of a magnet coupled to an indwelling medical device using a plurality of magnetic sensors. Table 1 below lists documents that disclose devices for determining the location and orientation of magnetic devices within implantable medical devices.
TABLE 1
Patent Number
Inventors
Title
U.S. Pat. No. 5,637,083
Bertrand et al.
Implantable Adjustable Fluid
Flow Control Valve
2002/0022793
Bertrand
Tool for Adjusting an
Implantable Adjustable
Fluid Flow Control Valve
U.S. Pat. No. 5,879,297
Haynor et al.
System and Method to
Determine the Location and
Orientation of an Indwelling
Medical Device
U.S. Pat. No. 6,129,668
Haynor et al.
System and Method to
Determine the Location and
Orientation of an Indwelling
Medical Device
All documents listed in Table 1 above are hereby incorporated by reference herein in their respective entireties. As those of ordinary skill in the art will appreciate readily upon reading the Summary of the Invention, Detailed Description of the Preferred Embodiments and claims set forth below, many of the devices and methods disclosed in the patents of Table 1 may be modified advantageously by using the structures and techniques of the present invention.
SUMMARY
In general, the invention is directed to an electronic device for determining the location and orientation of magnets coupled to implantable medical devices. The electronic device is included in a magnetic-based indicator tool for interaction with an implanted medical device to assess a setting associated with the device. The invention has certain objects. That is, various embodiments of the present invention provide solutions to one or more problems existing in the prior art with respect to the magnetic-based indicator tools for interaction with implanted medical devices.
The problems include, for example, inaccuracies in the setting indication provided by a compass-based indicator tool due to the effects of external magnetic fields. The compass-based indicator tool interacts with a magnetic target that creates an internal magnetic field, and causes the compass to indicate a particular position. The position of the compass is indicative of the setting of the implantable medical device, e.g., the position of a fluid flow valve. External magnetic fields, and especially the Earth's magnetic field, may interfere with the compass and create an incorrect device setting indication.
Various embodiments of the present invention have the object of solving the foregoing problems. For example, it is an object of the present invention to overcome at least some of the disadvantages of the foregoing procedures by providing an electronic-based magnetic location and orientation based indicator tool that produces more accurate and reliable indications of implantable device settings. To that end, it is a further object of the present invention to reduce the effects of an external magnetic field on the electronic-based indicator tool, and thereby enhance the accuracy of the tool. It is another object of the invention to reduce the effects of an external magnetic field by electronically measuring and compensating for the presence of the external magnetic field. The invention is also capable of sensing the implanted magnet at a greater distance (such as in the case where there is thick skin or scalp tissue over the implanted device) than the prior compass-based tool. A third advantage is that the current invention is that it is much less sensitive to alignment with the implanted device. The compass based tool must be positioned within about 1 cm or less from coaxial with the implanted device to provide an accurate reading. With the current invention, the implanted device must only be encircled by the sensor array. Precise coaxial centering is not required.
Various embodiments of the invention may possess one or more features capable of fulfilling the above objects. In general, the invention is directed to an electronic magnetic-based indicator tool that includes a plurality of magnetic field sensors and a processing system that uses data generated from the plurality of magnetic field sensors to determine a location and orientation of a magnetic indication device. The magnetic indication device, being coupled to a valve used to control operation on an implantable flow control device, permits the processing module to further determine a setting for the valve from the location and orientation of the magnetic indication device.
In another embodiment, the invention is directed to a system comprising an implantable medical device that includes an implantable flow control device, an electronic magnetic-based indicator tool, and an adjustment tool. The implantable flow control device includes a magnetic device coupled to a control valve. The electronic magnetic-based indicator tool that includes a plurality of magnetic field sensors and a processing system that uses data generated from the plurality of magnetic field sensors to determine a location and orientation of a magnetic indication device. The magnetic device, being coupled to a valve used to control operation on an implantable flow control device, permits the processing module to further determine a setting for the valve from the location and orientation of the magnetic indication device.
In another embodiment, the invention is directed to a method which comprises placing a electronic magnetic-based indicator tool adjacent to an implantable medical device, detecting a magnet field from a plurality of magnetic field sensors, estimating a background magnet field from a sequence of magnetic field data observed over time, and indicating a device setting of the implantable medical device, wherein the device setting is indicated by the indicator tool. The plurality of target magnetic field sensors and the plurality of background magnetic field sensors are located a distance apart sufficient to permit the background magnetic field sensors to only detect ambient magnetic fields when the target magnetic field sensors are located near the implanted flow control device.
In comparison to known implementations of magnetic-based indicator tools for implantable medical devices, various embodiments of the present invention may provide one or more advantages. For example, if the implantable medical device is implanted subcutaneously on a patient's skull, an electronic magnetic-based indicator tool in accordance with the invention is capable of taking a more accurate device setting measurement through the patient's skin. As a magnetic-based indicator tool moves further away from the magnet contained within an implantable medical device, external magnetic fields have a relatively greater influence on the indicator tool. The magnetic sensors of the present invention enable estimation and compensation of the external magnetic fields and thus prevent the corruption of the device setting measurement, even as the distance increases between the indicator tool and the implantable medical device. The electronic indicator tool is then able to display accurate device setting values in the cases where the patient's skin is thicker than normal. In this way, the electronic indicator tool may eliminate the need for x-rays to determine an implantable medical device setting through a surface, such as a patient's skin.
It is a primary object of the present invention to provide an improvement to magnetic-based indicator tools for use with implantable medical devices. This and other objects of the invention will become clear from an inspection of the detailed description of the invention and from the appended claims. Throughout the description, like elements are referred to by like reference numbers. An element referred to by a reference number has all the attributes and characteristics of the element as described wherever in the description unless specifically stated otherwise.
The above summary of the present invention is not intended to describe each embodiment or every embodiment of the present invention or each and every feature of the invention. Advantages and attainments, together with a more complete understanding of the invention, will become apparent and appreciated by referring to the following detailed description and claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram illustrating a subcutaneously implantable and adjustable fluid flow control device for use with an improved valve reader device according to an example embodiment of the present invention.
FIG. 2 is a cross-sectional diagram further illustrating the subcutaneously implantable and adjustable fluid flow control device of FIG. 1 .
FIG. 3 is a diagram illustrating an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention.
FIG. 4 is a block diagram illustrating a general programmable processing system for use in a handheld device such as an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention.
FIG. 5 is a block diagram illustrating a display showing a magnetic device within an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention.
FIG. 6 is a block diagram illustrating a set of processing modules within an improved electronic valve reader and adjustment tool in accordance with another example embodiment of the present invention.
FIGS. 7 and 8 illustrate improved implantable valve devices possessing additional magnetic devices for used with an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention.
FIG. 9 illustrates a diagram of an improved electronic valve reader while used with an accompanying adjustment tool in accordance with an example embodiment of the present invention.
FIG. 10 illustrates a flowchart of a method for use of an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention.
DETAILED DESCRIPTION
As shown in the drawings for purposes of illustration, the FIGS. 1 and 2 illustrate a subcutaneously implantable and percutaneously adjustable fluid flow control device, generally designated in the accompanying drawings by the reference numbers 10 . The fluid flow control devices 10 is intended for use in a surgically implanted physiological shunt system for draining fluid from one portion of the body to another. In order to connect, for example, the device 10 in such a system, the device includes an inlet connector 12 and an outlet connector 14 which each receive one end of a piece of surgical tubing (not shown). The ends of the surgical tubing are placed over the connectors 12 and 14 and secured thereon by a single ligature just inside of an annular ridge formed near the end of each connector.
When the flow control device 10 is used in a drainage system intended for the treatment of hydrocephalus, the inlet connector 12 is fluidly connected with a proximal catheter that is inserted through the skull into a brain ventricle containing cerebrospinal fluid under pressure. The outlet connector 14 is fluidly connected to a distal catheter that serves to discharge cerebrospinal fluid to, for example, the atrium portion of a patient's heart. Ordinarily the flow control device 10 will be surgically implanted on the patient's skull with a flap of skin overlying the device. To facilitate holding the device in its desired position after implantation, a generally flexible mounting plate can be provided with one or more suture holes.
The highly reliable fluid flow control device has a single flow path there through and a valve mechanism which can be percutaneously adjusted when the device is subcutaneously implanted by the use of the valve adjuster and reader device of the present invention. The flow control device 10 include a relatively rigid, molded plastic base invested within an elastomeric casing 16 which, together, define a fluid flow path through the fluid flow control devices from the inlet connector 12 to the outlet connector 14 . The valve housing includes a percutaneously adjustable valve mechanism that restricts the flow of fluid through the device 10 . Coupled to the adjustable valve mechanism is a magnetic indication device that may be externally located using an indicator tool. The present invention provides an improved mechanism for determining the setting of the adjustable valve mechanism. The flow control device is described in more detail in U.S. Pat. No. 5,637,083 issued to Bertrand et al. entitled “Implantable Adjustable Fluid Flow Control Valve.”
FIG. 3 is a diagram illustrating an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention. The electronic valve reader 300 includes three main components: a valve reader sensor module 303 , a display module 301 , and an adjustment tool 305 . The valve reader sensor module 303 corresponds to the sensor mechanism that electronically determines the location and orientation of a magnetic indication device that is an integral part of the implanted flow control device disclosed in the '083 patent. Valve reader sensor module 303 uses a plurality of magnetic sensor devices, as discussed below and as disclosed in detail in the '668 and the '297 patents identified above, to identify the location and orientation of the implanted magnetic device. Processing modules within the valve reader sensor module 303 determine a corresponding valve setting for the adjustable valve within the implanted flow control device based upon location and orientation of the magnetic indication device. In one embodiment, a valve reader sensor module 303 contains the magnetic field sensors and some associated support electronics, while processing, display, power supply circuitry, and batteries may be contained inside the rest of the unit 301 .
From all of this information, the processing modules within the valve reader sensor modules 303 generate display data that is subsequently output to the display module 301 of the electronic valve reader 300 . The display data represents a visual indication of the orientation of a valve control mechanism within the flow control device. The user of the reader may use this display data to determine whether the valve within the flow control device is set to a desired position.
In prior valve indicator devices, a magnetic compass has been used to determine an orientation for the magnetic indication device that is coupled to the valve control mechanism within the flow control device. This compass-based indication mechanism is replaced within the improved electronic valve reader with the electronic-based magnetic location and orientation processing system similar to the devices disclosed within the '668 and the '297 patents identified above. These prior patents locate a position and orientation of a magnetic device, such as a medical tube or catheter, but fail to indicate a valve orientation setting as a result of the determined orientation. The indicator mechanism of the present invention is less sensitive to environmental sources of magnetic fields that required prior indicator tools to be located extremely close to the flow control device in order to function properly.
When operating, the valve reader sensor module 303 , and its plurality of magnetic sensor modules, are placed near the patient at a location in which the implanted flow control device is believed to be located. In many cases, a physician may accurately identify this location for the flow control device and the valve reader sensor module 303 may be located on top of the implanted flow control device. The electronics in the valve reader sensor module 303 process detected signals corresponding to magnetic fields generated by the magnetic indication device that is part of the flow control device. These electronic signals may also correspond to magnetic fields associated with ambient and environmental sources. The effects from these ambient and environmental sources may be subtracted from the detected signals to determine a more accurate indication for the location and orientation of the magnetic indication device that is part of the flow control device. The magnetic field data from each of the plurality of magnetic sensor modules permits a determination of the location and orientation of a magnetic indication device to be expressed in five degrees of freedom: x, y, z, pitch, and yaw.
From this determined orientation of the magnetic indication device that is part of the flow control device and from the known orientation of the flow control device, the processing modules may determine the present setting for the valve within the flow control device. The processing required to translate the position of the magnetic indication device to the setting of the valve within the flow control device is easily determined in that the value corresponds to a rotatable wheel having a position within a circle of rotation for the magnetic indication device that directly corresponds to the setting of the valve within the flow control device. This translation processing is well understood and disclosed in detail within the '668 and '297 patents as the orientation of a compass within its circle of rotation directly corresponded to the setting for the valve within the flow control device. Once the current position of the valve is determined and displayed, the adjustment tool 305 may be used to alter the setting for the valve within the flow control device.
FIG. 4 is a block diagram illustrating a general programmable processing system for use in a handheld device such as an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention. In an exemplary embodiment of a handheld processing system 400 , computing system 400 is operative to provide a magnetic valve reader processing system. Those of ordinary skill in the art will appreciate that the magnetic valve reader 400 may include many more components than those shown with reference to a computing system 400 shown in FIG. 4 . However, the components shown are sufficient to disclose an illustrative embodiment for practicing the present invention.
As shown in FIG. 4 , magnetic valve reader processing system 400 is used in connection with an implantable flow control device 10 as needed. The magnetic valve reader processing system 400 also includes processing unit 412 , video display adapter 414 , and a mass memory, all connected via bus 422 . The mass memory generally includes RAM 416 , ROM 432 , and may include one or more mass storage devices, such as a removable memory device such as a Compact Flash, Smart Media, or Secure Digital memory card. The memory devices may store an operating system 420 for controlling the operation of magnetic valve reader processing system 400 . It will be appreciated that this component may comprise a general purpose server operating system as is known to those of ordinary skill in the art, such as UNIX, MAC OS™, LINUX™, or Microsoft WINDOWS®. Basic input/output system (“BIOS”) 418 is also provided for controlling the low-level operation of processing system 400 .
The mass memory as described above illustrates another type of computer-readable media, namely computer storage media. Computer storage media may include volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules or other data. The mass memory also stores program code and data for providing a magnetic valve reader processing program. More specifically, the mass memory stores applications including magnetic valve reader program 430 , and other programs 434 , and similar analysis tool applications 436 as may be needed. The magnetic valve reader processing program 430 includes computer executable instructions which are executed to perform the logic described herein.
The magnetic valve reader processing system 400 also comprises input/output interface 424 for communicating with external devices, such as a touch screen and similar input devices, or other input devices not shown in FIG. 4 . Likewise, the magnetic valve reader processing system 400 may further comprise additional mass storage facilities also not shown should additional data storage be needed.
One skilled in the art will recognize that the processing system illustrated within FIG. 4 may represent a set of processing components typically found within a handheld or similar dedicated processing system. Of course, other processing systems including general purpose computing systems containing additional peripherals and user interface devices may also be used to implement the programmable processing according to various embodiments of the present invention without deviating from the spirit and scope of the present invention as recited within the attached claims.
FIG. 4 illustrates an example of a suitable operating environment in which the invention may be implemented. The operating environment is only one example of a suitable operating environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Other well known computing systems, environments, and/or configurations that may be suitable for use with the invention include, but are not limited to, personal computers, server computers, hand-held or laptop devices, multiprocessor systems, microprocessor-based systems, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like. For example, a dedicated processing system may consist of a digital signal processor (DSP) for performing the required floating-point math, various internal memory types including FLASH, ROM, RAM, and FPGA, some minimal external memory for the valve calibration system, and a user interface and display driver chip to run the switches and custom LCD display. A proprietary embedded operating system is and a specifically written application for implementing the reader program may be included.
The invention may also be described in the general context of computer-executable instructions, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments.
Processing devices typically include at least some form of computer readable media. Computer readable media can be any available media that can be accessed by these devices. By way of example, and not limitation, computer readable media may comprise computer storage media and communication media. Computer storage media includes volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by processing devices.
Communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and includes any information delivery media. The term “modulated data signal” means a signal that has one or more of its characteristics set or changed in such a manner as to encode information in the signal. By way of example, and not limitation, communication media includes wired media such as a wired network or direct-wired connection, and wireless media such as acoustic, RF, infrared and other wireless media. Combinations of any of the above should also be included within the scope of computer readable media.
Additionally, the embodiments described herein are implemented as logical operations performed by a programmable processing devices. The logical operations of these various embodiments of the present invention are implemented (1) as a sequence of computer implemented steps or program modules running on a computing system and/or (2) as interconnected machine modules or hardware logic within the computing system. The implementation is a matter of choice dependent on the performance requirements of the computing system implementing the invention. Accordingly, the logical operations making up the embodiments of the invention described herein can be variously referred to as operations, steps, or modules.
FIG. 5 is a block diagram illustrating a magnetic device within an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention. The electronic valve reader 500 includes an opening 501 within the reader 500 that permits the reader 500 to be positioned over an implanted flow control device. The reader also includes a plurality of magnetic sensor devices 510 - 513 that each detect the magnetic field at their respective locations within reader 500 . The magnetic field detected by each sensor 510 - 513 at its location is due to both background environmental magnetic fields and that arising from a magnetic device 520 located within the opening 501 . As such, signals from the various magnetic sensor devices 510 - 513 may be processed to determine a location and orientation of the magnetic device 520 relative to the known positions of the magnetic sensor devices 510 - 513 .
When the magnetic device 520 that is detected by the plurality of magnetic sensors corresponds to a magnetic indication device that is part of the valve within a flow control device, it is desired to determine the orientation of the magnetic indication device relative to a known position of the flow control device in order to accurately determine the setting for the valve within the flow control device. In one embodiment, the user orients the electronic valve reader to a known orientation relative to the implanted flow control device. As such, the orientation of the magnetic indication device, and thus the valve, is determined relative to this known orientation. Prior indicator tools that utilize a compass-based indicator required users to orient the tools relative to the flow control device to perform this identical determination. In other embodiments, additional measurements for additional position references may be used to perform this orientation and position translation operation. Because processing within the reader 500 may be updated periodically, and may occur several times per second, ambient and environmental sources of magnetic fields may be estimated and subtracted from the observed signals generated by the plurality of magnetic sensor devices 510 - 513 . These magnetic sensor devices 510 - 513 are generally located at dispersed locations about the reader. In one embodiment, these sensors 510 - 513 may be located about one of the respective four corners of the reader. Use of these sensors in this fashion permits the reader device to sense implanted magnetic devices at greater distances while being less sensitive to being centered coaxially over the implanted flow control device as compared to compass-based devices.
FIG. 6 is a block diagram illustrating a set of processing modules within an improved electronic valve reader and adjustment tool in accordance with another example embodiment of the present invention. The electronic valve reader 600 is constructed using a display module 610 that is surrounded by a plurality of magnetic field sensor modules 601 - 604 . Each of these four sets of magnetic field sensors 601 - 604 contain three separate sensors so as to measure the full, three-dimensional vector magnetic field detected by the module at its location. The reader 600 also contains an analog-to digital converter module 621 and a combined magnetic field sensor module 611 to electronically process the signals generated by the magnetic field sensor modules 601 - 604 to obtain digital measurements corresponding the observed magnetic field.
These digital measurements of the observed magnetic field are subsequently processed within a processing module 620 to determine the location and orientation of a magnetic device within a field of view for the reader 600 . The processing module corresponds to a programmable processing system as discussed above with respect to FIG. 4 . The processing module performs operations upon the measured magnetic field data to determine the magnetic field generated by the magnetic device while subtracting an estimate for ambient and environmental magnetic field also observed by the magnetic field sensors 601 - 604 . The processing performed in this determination of the location and orientation of the magnetic indication device is described in more detail within the '668 and the '397 patents to Haynor et al. discussed above.
From the above location and orientation of the magnetic device relative to the implantable flow control device, the processing module further determines the setting of the valve. This setting data is then used to generate a display image to be presented to a user on the display module 610 . The processing module 620 outputs the display data to the display module 610 through a display driver 612 .
The device may further contain a memory card reader 631 for accepting computer readable storage media. In one embodiment, this storage media may include compact flash, start media, secure digital, and memory stick memory cards for providing the device replaceable memory containing data usable by the device. For example, an implantable flow control device may permit fluid to flow at a particular pressure setting that corresponds to a particular setting on the valve. When the reader determines the valve setting, the data from the memory card may be used to display the corresponding pressure setting. Because the valve-to-pressure setting may vary from particular models of implantable flow control devices, the use or a memory card corresponding to the model of the flow control device will permit the reader device to easily display pressure values for a wide variety of flow control devices without needing to maintain all of the valve to pressure setting data for all devices at one time.
FIGS. 7 and 8 illustrate improved implantable valve devices possessing additional magnetic devices for used with an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention. As discussed above, the location and orientation of a detected magnetic device that is coupled to an implantable flow control device is used relative to an estimated position of the flow control device to determine the valve setting. This estimate is made because the valve is set by positioning the magnetic device coupled to the valve such that as the valve rotates about a known circular position, the magnetic field of the magnetic device also rotates about the same circle. In existing indicator tools, the tools must be aligned manually by a user into an orientation aligned with the implanted flow control device. This alignment process is also used in one embodiment of the electronic valve reader as discussed above.
In an alternate embodiment, an additional magnet 710 is coupled to the implantable flow control device 700 in a location separate from the valve 701 and its magnetic indicator device 703 . The electronic reader, using the same processing to detect the magnetic device as discussed above, detects the location and orientation of the additional magnet 710 . The location of the additional magnet 710 provides a reference point for the processing modules within the electronic valve reader to expressly determine the orientation of the electronic valve reader. The reader does not require the implanted flow control device to be position into a known orientation relative to the reader in order to accurately determine the setting of the valve. In this alternate embodiment, the setting of the valve may be made by determining the orientation of the magnetic device 703 coupled to the valve 701 relative to the position of the additional reference magnet 710 . Using this method, the setting of the valve may be made accurately, yet independently of the orientation of the reader to the implanted flow control device.
In yet another embodiment, two separate reference magnets 810 - 811 are added to the valve 801 so that the orientation of the valve 801 and its corresponding magnetic indicator device 803 independently of the position of the reader. This second embodiment also works with separate embodiment of the reader. In alternate embodiment for the reader, the reader may utilize less magnetic sensors. The sensors would provide information regarding the general orientation of the detected magnetic fields. When the user orients the reader in this embodiment into a desired orientation aligned with the implanted flow control device, the setting of the valve 801 may be determined from the orientation of the magnetic fields observed from the magnetic indicator device 803 coupled to the valve 801 .
FIG. 9 illustrates a diagram of an improved electronic valve reader while used with an accompanying adjustment tool in accordance with an example embodiment of the present invention. In this embodiment, the reader 901 contains a display module 911 that displays the position of the valve once the reader 901 is positioned near an implanted flow control device. This process of determining the position of the valve is discussed above in detail.
Once the current position of the valve is determined and displayed, the adjustment tool 905 may be used to alter the setting for the valve within the flow control device. The adjustment tool corresponds to a magnetic coupling device that is placed over the valve reader sensor module 903 to orient the adjustment tool directly over the magnetic indication device that is part of the valve. The adjustment tool 905 magnetically couples to the magnetic indication device such that a rotation of the adjustment tool 905 within its location at above the valve reader sensor module 903 causes the magnetic indication device to rotate within the valve. This rotation of the magnetic indication device changes the settings for the valve within the flow control device as the magnetic indication device is directly coupled to the valve setting mechanism. The operation of the adjustment tool 905 is disclosed in additional detail with the published U.S. Patent application to Bertrand et al., No. 2002/0022873 as identified above. These modules operate together as disclosed herein to provide the operation of an electronic valve reader and valve adjustment tool.
FIG. 10 illustrates a flowchart of a method for use of an improved electronic valve reader and adjustment tool in accordance with an example embodiment of the present invention. The method for determining the setting of a valve within an implantable flow control device begins by determining an estimate for background magnetic fields 1001 . This value is determined by obtaining a set of magnetic field values that are averaged to obtain this estimate for the background fields from environmental and ambient sources. Next, the method continues by placing 1003 of the reader near the implantable flow control device within a patient. Because the magnetic field typically observable at a distance of 12 cm from a typical magnetic indicator device coupled to an implantable flow control device is generally less than 5 milliGauss, the reader must be placed as close as possible to the flow control device to permit the reader to detect this magnetic field within the Earth's background magnetic field typically observed to be approximately 500 milliGauss.
Once the reader is located as close to the flow control device as possible, the reader detects an observed magnetic field 1005 from all sources. The background magnetic fields estimate 1001 is subtracted from the observed values 1005 to obtain a position and orientation for the magnetic indicator device 1007 coupled to the valve that is part of the implanted flow control device. The detected magnetic field measurements and processed position and orientation for the magnetic indicator device are repeated at a rate of several times per second.
The orientation of the magnetic indicator device is compared to a known orientation of the flow control device to determine a setting 1009 for the valve of the flow control device. The known orientation of the flow control device may be manually determined by requiring the reader to be oriented to a particular position relative to flow control device. The known orientation of the flow control device may also be determined from a detection of other reference positions, such as a separate reference magnet as discussed above. Once the reader has determined the setting for the valve, a user may utilize an adjustment tool to magnetically rotate and thus alter the setting of the valve as desired.
In the claims, any means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents but also equivalent structures. Thus, although a nail and a screw may not be structural equivalents in that a nail employs a cylindrical surface to secure wooden parts together, whereas a screw employs a helical surface, in the environment of fastening wooden parts a nail and a screw are equivalent structures.
Many embodiments of the invention have been described. Various modifications may be made without departing from the scope of the claims. These and other embodiments are within the scope of the following claims.
Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and scope of the present invention.
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The invention is directed toward a magnetic valve reader used as an indicator tool. The magnetic valve reader determines a location and an orientation for a magnetic indicator device to indicate a device setting of an implantable medical device. The implantable medical device includes the magnetic indicator device coupled to a valve on the implantable medical device. External magnetic fields, specifically the Earth's magnetic field, may interfere with the compass and create an incorrect device setting indication. The electronic reader estimates the external magnetic fields to subtract the estimate from received data to minimize any influence that external magnetic field has on the accuracy of the device setting measurement.
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BACKGROUND OF THE INVENTION
The present invention relates to actuator mechanisms and more particularly to a slide actuator mechanism that cycles a push-on, push-off electrical switch through on and off conditions.
A push-on, push-off electrical switch has an actuator shaft which if the shaft is sufficiently moved in an axial direction and then released, the switch contacts will change their condition. Thus, if the switch is initially in an off position and the shaft is sufficiently moved in the axial direction, then the switch changes to the on position. Similarly, if the switch is initially in the on position and the shaft is sufficiently moved in the axial direction, then the switch changes to the off position After the actuating shaft is moved to change the position of the switch contacts from off to on or from on to off, the actuating shaft is released and some device within the switch, for example a spring, restores the shaft to a location for the next actuating movement.
Push-on, push-off switches are commonly used as on/off power switches for electronic units, such as computers. Such switches are typically located on the front panel of the electronic unit to provide ready access and ease of operation for the operator.
A problem arises, however, from such a location on the front panel of an electronic unit in that the operation of other front panel mounted assets can inadvertently actuate the push-on, push off switch to the off position. An inadvertent change of the power switch of a computer from the on to the off condition can cause valuable data to be lost.
Thus, it is an object of the present invention to provide a switch actuator mechanism that is not prone to inadvertent actuation.
It is another object of the present invention to provide a switch actuator mechanism to reduce the sensitivity of a push-on, push-off switch to inadvertent actuation.
It is another object of the present invention to provide a switch actuator mechanism that converts a push-on, push-off switch to a slide-on, slide-off switch.
SUMMARY OF THE INVENTION
Briefly stated, in accordance with one aspect of the invention the foregoing objects are achieved by providing a switch actuator mechanism, including push-on, push-off switch and a device for slidably actuating said push-on, push-off switch. To provide additional protection against inadvertent switch actuation, this switching mechanism can be arranged such that the actuating shaft of the push-on, push-off switch, which is moved in an axial direction to change a condition of the switch from on to off, is actuated by the slidably actuating device by sliding in a direction that is perpendicular to the axial direction of the shaft.
In another aspect of the invention, the aforementioned objects may be achieved by providing a mechanism for an electronic unit, including: a front panel having an elongated hole therein; a push-on, push-off switch mounted within the electronic unit, this switch has an actuator shaft and the switch is mounted such that the shaft is in a spaced relationship with the elongated hole in the front panel; a device for imparting a transverse motion along the elongated hole mounted behind the front panel, the transverse motion device having a portion that extends through the elongated hole; a device connected to the transverse motion device for transferring a transverse force to the shaft; and a device for converting the transverse force to an axial force for changing a condition of the switch.
Various objects appear from a reading of the foregoing summary of the invention and other objects and further scope of applicability of the present invention will appear from the following detailed description. It should be understood that the detailed description indicates exemplary embodiments of the invention and which are given by way of illustration only since changes and modifications may be made within the spirit and scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
While the specification concludes with the appended claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention, it is believed that the invention will be better understood from the following description taken in conjunction with the accompanying drawings in which:
FIG. 1 is a partially broken away plan view of a electronic unit showing a push-on, push-off switch location, a switch actuator mechanism and a cross section of a front panel in accordance with one embodiment of the invention.
FIG. 2 is a partial front view of the electronic unit shown in FIG. 1 showing frontal details a slide member.
FIG. 3 is a plan view of a torsion spring such as the one shown in FIGS. 1 and 4.
FIG. 4 is a partially broken away plan view of an electronic unit showing a push-on, push-off switch location, a switch actuator mechanism and a cross section of a front panel according to another embodiment of the invention
DETAILED DESCRIPTION
Referring now to FIG. 1, an electronic unit 10, such as a computer, is shown in a plan view with its top section removed to expose internal details. In addition to the section removal, the electronic unit 10 is also partially broken away to simplify the detail shown in FIG. 1. Electronic unit 10 has a front panel 12 which is shown in section. Front panel 12 has an elongated hole 14, through which a portion of slide member 16 protrudes. Referring briefly to FIG. 2, a broken away portion of the front panel 12 is shown in a front view. This front view shows elongated hole 14 with a protruding portion 17 of slide member 16 protruding therethrough.
Referring back to FIG. 1, slide member 16 also has a support member 18 protruding in an opposite direction from the protruding portion 17. Preferably, the support member 18 has a roller 19, the function of which will be explained below.
A guide plate 20 is fastened by fasteners 22, 23 and other fasteners (not shown) to guide the slide member 14. The guide plate 20 has a slot therein (not shown) to provide for passage of the support member 18 The guide plate 20 also guides the slide member 14 such that the slide member 14 travels in a direction that is substantially in parallel with front panel 12 Alternatively, upper and lower guide plates that are positioned to form a channel could be used instead of a single guide plate 20 with a slot.
Fastener 22, which may be a screw, may also secure a spring 24. Referring to FIG. 3, the spring 24 is shown as a torsion spring in this plan view. Referring back to FIG. 1, the ends 26, 28 of the spring 24 respectively bear against fastener 23 and support 18 The purpose of this spring will be explained below.
A push-on, push-off switch 30 is shown in block diagram form. The push-on, push-off switch is fastened on the inside of the electronics unit 10 in any of a number of ways, and how the switch 30 is fastened is not relevant to the present invention. The push-on, push-off switch 30 is located in a spaced relationship to the slide member 16, which is relevant to the present invention.
The push-on, push-off switch 30 has a shaft 32. This shaft 32 is the actuating part of the push-on, push-off switch 30. Assuming the switch 30 is in the off position, if the shaft 32 is pushed sufficiently to cause the condition of the switch to change, a change to the on condition occurs. Similarly, if the switch 30 is in the on position and the shaft 32 is pushed sufficiently to cause the switch 30 to change, a change to the off condition occurs.
An inclined plane member 34 is attached to the free end of the shaft 32. The inclined plane member 34 is sized such that the roller 19 bears against its surface 36 as the slide member 16 is moved in the direction A. As the roller 19 bears against the surface 36, part of the transverse pushing force is converted to a force in the axial direction of the shaft 32. This axially directed force pushes the shaft 32 inward. By sizing the roller 19, the inclined plane member 34 properly to provide sufficient displacement for the shaft 32 to cause a change of condition of the switch 30, the desired operation is achieved The switch 30 must also be located in a spaced relationship to the roller 19 to provide for sufficient interaction of the roller 19 with the inclined plane member 34 to achieve the change of condition.
With a push-on, push-off switch, usually the shaft must be extended after each condition change to prepare the switch for the next condition change. Most such switches have an internal elastic member of some type; however, if the internal elastic member does not return the shaft as necessary, an external spring 40 can be added.
Since the slide member 16 must traverse the elongated hole 14 in direction A every time to move the shaft 32 and actuate the switch 30, it would be convenient to return the slide member 16 in the direction B in preparation for the next actuation of the switch 30. In addition to convenience, returning the slide member 16 to in the direction B clears the space in front of inclined plane member 34 and allows the shaft 32 to return to the fully extended position in preparation for the next actuation. This return action is provided by the spring 24. As the slide member is pushed by the operator in direction A, spring 24 stores energy, and when the operator releases the slide member 16 spring 24 releases that energy and restores the slide member 16 to its rest position.
Referring now to FIG. 4, another embodiment of the invention is shown. The electronic unit 10' is the same as the electronic unit 10 shown in FIG. 1, except that the inclined member 34' has a curved surface 36' instead of an inclined plane surface of constant slope as the surface 36 shown in FIG. 1.
Thus, it will now be understood that there has been disclosed a switch actuator mechanism for a push-on, push-off switch. While the invention has been particularly illustrated and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form, details, and applications may be made therein. For example, the roller can be replaced by a non-rolling protrusion, such as a rounded support, on the back of the slide member. It is accordingly intended that the appended claims shall cover all such changes in form, details and applications which do not depart from the true spirit and scope of the invention.
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An actuator mechanism which is located at the front of an electronic unit and converts the push-on, push-off action of a switch to a sliding action. By converting the actuating action from an in-and-out pushing motion to a transverse sliding motion, inadvertent actuation of this switch is all but eliminated. This conversion is provided in a simple, cost effective mechanism.
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BACKGROUND OF THE INVENTION
A return flow prevention arrangement in a draw-off tap with an extensible outlet nozzle for a sink basin is known from U.S. Pat. No. 4,696,322. This draw-off tap includes a mixing valve with a hollow sphere-shaped valve body in the tap housing. The housing has two supply connections and one mixed water outlet channel. A diaphragm-like ventilating valve, which opens into the mixed water channel within the mixing valve body, is built into the valve body of the mixing valve. The air supply openings to the ventilating valve are arranged on the upper side of the mixing valve body. If one of the supply lines has reduced pressure, air is sucked in through the ventilating valve and thus water is prevented from being sucked in from the outlet nozzle. This is advantageous because the extensible nozzle can lie, under some circumstances, in the sink basin filled with dirty water.
The drawbacks with this known return flow safety valve arrangement are that the return flow of the water into the supply lines cannot be reliably prevented by the ventilating valve alone, and the ventilating valve is not accessible for maintenance. When it is defective, the entire mixing valve body must be replaced, which is quite expensive. In addition, it is almost impossible to check the functionality of the ventilating valve.
SUMMARY OF THE INVENTION
An object of the present invention is thus to provide a return flow prevention arrangement of the aforementioned kind that is reliable and can be repaired in a cost-effective manner. This object is achieved by providing a safety valve arrangement for a single lever water tap which includes, disposed coaxially in series in a removable module, a first air ventilating valve, a second air ventilating valve, and a non-return valve coupled to and controlling the second ventilating valve. The non-return valve is disposed in the mixed water outlet passage of the tap such that when it opens in response to a water demand, it automatically closes the second ventilating valve, and vice versa.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a sectional view of a draw-off tap in accordance with the invention; and
FIG. 2 is a partial cross sectional view of the tap housing.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The tap 1 shown in FIG. 1 includes a tap housing 2 with a mixing valve 3, two supply connections 4 (of which only one is visible, to which supply lines 5 for hot and cold water are attached, and a mixed water connection 6, to which an extensible outlet nozzle 8 in the form of a hand spray is attached. Downstream of the connection 6, two non-return valves 9, 10 are installed in the mixed water line 7 leading to the outlet nozzle. Housing 2 has a contact face 11 with which it abuts against an upper surface 12 of a sink basin 13, which is only partially shown. Surface 12 defines the highest level that the water standing in the sink basin can reach.
A module 18 comprising a two-piece, screwed together sleeve 19, two ventilating valves 20, 21, and a non-return valve 22 are screwed into a stepped bore 17 (FIG. 2) of the housing 2. The sleeve 19 has on its circumference an annular groove 23, which is sealed by two o-rings 24, 25. The mixed water channel 26 coming from the mixing valve 3 empties radially into the annular groove 23. Several radial bores 27 lead from the bottom of the groove into a chamber 28, which is closed against the outside by a separating wall 29 of sleeve 19 with an axial, conical bore 30. Bore 30 forms the valve seat for the fructo-spherical, plastic valve body 36 of valve 21. Valve body 36 is rigidly connected by a shaft 37 to the coaxial valve body 38 of non-return valve 22. Valve body 38 is slid over shaft 37 with an axial bore and secured with a snap ring 39. Valve body 38 comprises a rigid disk 40 and an elastomer disk 41 having a peripheral sealing lip 42, which abuts against a radial shoulder 43 of sleeve 19. The diameter of the sealing lip 42 is significantly greater than the diameter of the valve body 36 at the point where the valve body abuts against bore 30 when valve 21 is closed. In the pressureless state valve body 3 is forced into the closed position of the non-return valve 22 by a spring 44. Spring 44 is locked into a groove 45 of disk 40 so that it forms part of the replaceable module 18.
The first ventilating valve 20 is also a seat valve. Its valve body 48 again comprises a rigid disk 49 and an elastomer disk 50 having a peripheral sealing lip 51, which abuts against the inside 52 of face wall 53 of sleeve 19. An axial bore 54 is drilled through face wall 53 as the air supply opening, and a screw driver slot 55 for assembly and disassembly is cut into the face wall. Valve body 48 is also preloaded by a spring 56 into the closed position. Spring 56 is also locked into a groove 57 of disk 49. The spring 56 is selected such that valve 20 opens at very low pressure.
In service, when the mixing valve 3 is closed, the three non-return valves 9, 10, 22 and valve 20 are closed. If the mixing valve 3 is opened, water flows out of one or both supply lines 5 through channel 26 and into chamber 28, and builds up a pressure that opens the non-return valve 22 and thus automatically closes the ventilating valve 21. The water flows through the non-return valve 22 into an axial chamber 60 of bore 17, and from there through a radial bore 61 to connection 6. Due to the diameter differential between valve bodies 36, 38, the greater the pressure drop across and the flow through the non-return valve 22, the greater the closing force of valve 21. If the mixing valve 3 is closed again, the non-return valve 22 closes with the falling water pressure due to the spring 44, and the ventilating valve 21 is automatically opened. Owing to the closing and opening stroke of the valve 21 following each usage of the mixing valve 3, the valve 21 cannot calcify or otherwise be blocked by non-usage. The primary function of valve 21 is to prevent a short-term opening of the ventilating valve 20 when the mixing valve 3 is closed quite rapidly following a high flow of water, thus preventing the water from escaping through bore 54. If the flow of water is reduced very rapidly, a reduced pressure can form in chamber 60 due to the inertia of the water column still flowing in hose 7 and also in chamber 28 due to the still open non-return valve 22. However, since this reduced pressure stresses the still closed valve 21 in a closing sense, it cannot effect valve 20. Thus, with the second ventilating valve 21 coupled directly to the non-return valve 22, the ventilating valve 20 remains closed even when mixing valve 3 is closed quite rapidly; thus, no water can escape through the air supply opening 54.
If the pressure should fall in one of the two supply lines 5, e.g. due to a pipe line rupture when mixing valve 3 is open, the flow is stopped by the non-return valve 22 and it closes due to the force of spring 44. Thus, ventilating valve 21 is automatically opened and the reduced pressure in channel 26 acts on valve body 48 of ventilating valve 20, which opens against the force of spring 56 and allows air to flow via opening 54, channel 26 and mixing valve 3 into the supply line(s) 5. Valve body 38 of non-return valve 22 is also loaded in a closing sense by the reduced pressure so that no water can be siphoned in through outlet nozzle 8, which could, for example, lie in the sink basin which could be filled at least in part with dirty water. Thus, dirty water is effectively prevented from being sucked into the supply pipe network. In addition, due to the supply of air into the pipe network, dirt is prevented from being sucked into the network due to other taps that are less well protected or by leaks in the pipe network.
Since the ventilating valves 20, 21 and the non-return valve 22 are mounted in a readily replaceable module 18, these parts can be easily maintenance checked and, when necessary, be replaced at a low cost.
The radial bores 26 and 61 communicating with groove 23 and chamber 60 can be angled and distributed arbitrarily around the periphery of the housing 2 so that the installation position of the module 18 can be selected arbitrarily. Preferably its arrangement is constructed in such a manner that module 18 can be installed and removed without any problems when tap 1 is assembled. To this end it is preferred that bore 17 in tap housing 2 be attached on the side and above the contact face 11.
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A safety valve arrangement for a single lever water tap includes, disposed coaxially in series in a removable module 18, a first air ventilating valve 20, a second air ventilating valve 21, and a non-return valve 22 coupled to and controlling the second ventilating valve. The non-return valve is disposed in the mixed water outlet passage of the tap such that when it opens in response to a water demand, it automatically closes the second ventilating valve, and vice versa.
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BACKGROUND OF THE INVENTION
[0001] Heated molds for forming or welding plastic materials to one another have been used for many years. Generally, these molds are machined of metal to form cavities commensurate with the final shape of the article. Usually, the material(s) to be formed or welded are inserted within the mold and the mold is heated to a temperature sufficient to form or weld the materials into the configuration represented by the mold cavity. Usually, a coil is wound about the mold and heating is accomplished by RF energy applied to the coil resulting in heating by induction.
[0002] Heating of the mold to a temperature within a narrow temperature range is generally required in order to produce consistent results. This is a particular problem for the molds used in catheter forming because of the fast response time of the small molds and the need for accuracy and repeatability of the process and end result.
[0003] The conventional way of controlling the temperature of a mold is through use of a thermocouple lodged adjacent the mold. The thermocouple provides a signal in the manner of a feedback signal to control the electrical power supplied to the coil. Where temperature within a narrow range is not critical, such a thermocouple is adequate for temperature control purposes. However, there is a finite delay in heating the thermocouple through heat conduction from the mold due to the limited contact area therebetween. This can result in the surface of the mold cavity being at a higher temperature then that reflected by the thermocouple.
[0004] The net result of such heat losses and delays in transfer of heat to the thermocouple is that the signal generated by the thermocouple is inaccurate. Such inaccuracy will often result in excessive heating of the mold and overshoot of the temperature at the mold cavity surface. While it is possible to incorporate compensatory circuitry, additional expenses will be incurred and such compensatory circuitry would have to be modified as a function of the nature of the material being formed or welded, the ambient temperature as it impacts the degree of heat radiation from the mold and the location of the thermocouple on the mold.
SUMMARY OF THE INVENTION
[0005] A thermocouple is formed of two different metals soldered or welded together and connected to a galvanometer or a potentiometer to provide an indication of an electromotive force developed as a result of a temperature difference at their junction. To obtain minimal thermal loss contact between the two metals of the thermocouple and a mold, the temperature of which is to be measured, both metals of the thermocouple are welded to a surface of the mold as a unit. Alternatively, each of the two metals of the thermocouple may be individually welded to the mold at spaced apart locations. The resulting current generated by the electromotive force developed as a function of the temperature of the mold is very accurate in reflecting the temperature of the mold and minimal thermal losses and minimal time delay of heat transfer between the mold and the thermocouple are present.
[0006] It is therefore a primary object of the present invention to provide an accurate indication reflective of the temperature of a mold used to weld plastic materials with one another to form plastic materials.
[0007] Another object of the present invention is to provide a thermocouple coupled with a mold for generating an indication accurately reflective of the temperature of the mold.
[0008] Yet another object of the present invention is to provide an accurate control signal for maintaining a mold cavity at a predetermined temperature.
[0009] Yet another object of the present invention is to provide a control signal for controlling an inductively heated mold cavity.
[0010] A further object of the present invention is to provide a thermocouple as an integral part of a mold to generate a signal reflective of the temperature of the mold.
[0011] A yet further object of the present invention is to provide a thermocouple having its bi-metallic elements welded to a mold.
[0012] A still further object of the present invention is to provide a method for accurately sensing and controlling the temperature of a mold.
[0013] These and other objects of the present invention will become apparent to those skilled in the art as the description thereof proceeds.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will be described with greater specificity and clarity with reference to the following drawings, in which:
[0015] [0015]FIG. 1 is a perspective view of a mold and elements associated therewith;
[0016] [0016]FIG. 2 is a representative cross section of the mold and certain of its related components shown in FIG. 1;
[0017] [0017]FIG. 3 is a schematic of the prior art for sensing the temperature of a mold with a thermocouple;
[0018] [0018]FIG. 4 illustrates two separated metals of a thermocouple welded to a mold at separated locations;
[0019] [0019]FIG. 5 illustrates the two metals of a thermocouple unit welded to a mold at a common location; and
[0020] [0020]FIG. 6 illustrates a block diagram of the circuitry for heating and controlling the amount of heat applied to a mold.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] Referring to FIG. 1, there is illustrated a representative mold 10 for welding plastic materials, such as any of the various plastics, by applying heat to the materials to obtain a weld in conformance with the configuration of the mold cavity. Molds of this type may also be used to form plastic materials into a configuration commensurate with the mold cavity. A connector 12 mechanically supports the mold by a clip 14 extending therefrom into engagement with the mold. The connector also provides electrical connection to a circuit (see FIG. 6). As shown in further detail in FIG. 2, clip 14 may be in engagement with a groove 16 formed about mold 10 . A pair of electrical conductors 18 , 20 , electrically connect a coil 22 extending about a spool 24 of the mold. Radio frequency (RF) energy is applied to the coil through conductors 18 , 20 to inductively heat the mold. A thermocouple 26 is welded to the surface of spool 24 . The thermocouple will provide an indication via a pair of conductors 28 , 29 reflective of the temperature at the surface of the mold to which the thermocouple is welded.
[0022] Referring to FIG. 3, there is shown a conventional prior art arrangement between a mold 40 and a thermocouple 42 . Generally, the thermocouple is lodged adjacent the mold with resulting losses at the interface. The thermal conduction across the interface is relatively inefficient and the temperature of the thermocouple, seldom, if ever, approaches that of the contacted surface of the mold. Hence, the signal generated by the thermocouple and transmitted through conductors 44 , 46 provides an indication of a temperature less than that present at the surface of the mold cavity itself. Thus, accurate determination of the temperature at the mold cavity and acting upon the materials to be welded, is impossible to obtain. To overcome this discrepancy, compensatory circuitry or compensatory techniques have to be employed. Invariably, such compensatory schemes results in overshooting the desired temperature at the mold cavity and overheating or under heating the mold cavity.
[0023] Referring to FIG. 4, there is shown a mold 10 , such as the mold illustrated in FIGS. 1 and 2, having a mold cavity 30 . The mold cavity shown is particularly adapted for butt welding plastic tubing. Each of two metallic elements 32 , 34 of a thermocouple ( 26 ) is welded or soldered to mold 10 at spaced apart locations. Thereby each metallic element becomes an integral part of the mold. With such welding or soldering, thermal conduction from the mold to each metallic element of the thermocouple is greatly enhanced and the thermal losses and time delay of heat transfer attendant previous uses of a thermocouple are avoided. The resulting indication present on conductors 28 , 29 is very, very closely reflective of the actual temperature at the surface of mold cavity 30 .
[0024] Referring to FIG. 5, there is shown an alternative mechanical junction between thermocouple 26 and mold 10 . Each metallic element 32 , 34 of a conventional thermocouple 26 is welded or soldered to mold 10 at a common location. With such form of attachment, thermal conductivity across the interface between the mold and the thermocouple is greatly enhanced. Thereby, the indication generated by the thermocouple across conductors 28 , 29 is very very close to and reflective of the temperature at the surface of mold cavity 30 .
[0025] [0025]FIG. 6 illustrates a block diagram of the major components attendant operation of the present invention. A pulse width modulator (PWM) controls an oscillator formed as part of a circuit for generating a radio frequency (RF) signal. The RF signal is conveyed through a coaxial conductor 52 (conductors 18 , 20 in FIGS. 1 and 2) to mold 10 to heat the mold by induction. Thermocouple 26 generates an indication or signal on conductors 28 , 29 as a function of the temperature of the mold at the location the thermocouple is welded or soldered thereto. The signal is amplified through an amplifier (T C AMP) and conveyed to a differential amplifier 54 via conductor 56 . The differential amplifier compares the signal received from the thermocouple with a temperature reference signal developed by a temperature reference circuit (T C REF) and conveyed via conductor 58 . The output of the differential amplifier is conveyed via conductor 60 to the pulse width modulator (PWM) to increase or decrease the power control signal to cause an increase or decrease of the RF power applied to the mold in order to obtain a temperature match between the signal generated by the thermocouple and the signal generated by the temperature reference circuit (T C REF).
[0026] In summary, by welding or soldering the bimetallic elements of a thermocouple to a mold for welding or forming materials, the temperature sensed by the thermocouple is essentially equivalent to the temperature in the mold cavity and the thermal losses and time delays attendant prior art thermocouple controlled molds are completely avoided.
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A mold for forming plastic elements or for welding plastic elements to one another includes a thermocouple having its metallic elements welded to the mold to provide an accurate indication of the temperature of the mold. The metallic elements may be welded at a common location or at spaced apart locations. A circuit responsive to the temperature indication provided by the thermocouple controls the heating of the mold to maintain it at a predetermined temperature.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation of application Ser. No. 09/795,882, filed Feb. 28, 2001, now U.S. Pat. No. 6,410,420, issued Jun. 25, 2002, which is a continuation of application Ser. No. 09/136,384, filed Aug. 19, 1998, now U.S. Pat. No. 6,235,630, issued May 22, 2001.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to contact interfaces on the surface of semiconductor substrates and methods of forming the same. More particularly, the present invention relates to forming silicide interfaces for use with thin film devices and backend integrated circuit (“IC”) testing devices.
2. State of the Art
In the processing of integrated circuits, electrical contact must be made to isolated active-device regions formed within a semiconductor substrate, such as a silicon wafer. Such active-device regions may include p-type and n-type source and drain regions used in the production of NMOS, PMOS, and CMOS structures for production of DRAM chips and the like. The active-device regions are connected by conductive paths or lines which are fabricated above an insulative or dielectric material covering a surface of the semiconductor substrate. To provide electrical connection between the conductive path and the active-device regions, openings in the insulative material are generally provided to enable a conductive material to contact the desired regions, thereby forming a “contact.” The openings in the insulative material are typically referred to as “contact openings.”
Higher performance, lower cost, increased miniaturization of components, and greater packaging density of integrated circuits are goals of the computer industry. However, as components become smaller and smaller, tolerances for all semiconductor structures (such as circuitry traces, contacts, dielectric thickness, and the like) become more and more stringent. In fact, each new generation of semiconductor device technology has seen a reduction in contact size of, on average, about 0.7 times. Further, the reduction in size of integrated circuits also results in a reduction in the height of the integrated circuits.
Of course, the reduction in contact size (i.e., diameter) has resulted in a greatly reduced area of contact between the active-device regions and the conductive material. Regardless of the conductive material used to fill these small contact openings to form the contacts (such as tungsten or aluminum), the interface between the conductive material and active-device region must have a low resistance.
Various methods have been employed to reduce the contact resistance at the interface between the conductive material and active-device region. One such method includes the formation of a metal silicide contact interface atop the active-device region within the contact opening prior to the application of the conductive material into the contact opening. A common metal silicide material formed is cobalt silicide (CoSi x , wherein x is predominately equal to 2) generated from a deposited layer of cobalt. Cobalt silicide is preferred for shallow junctions of thin film structures because it forms very smooth, fine grained silicide, and will not form tightly bonded compounds with arsenic or boron atoms used in the doping of shallow junctions.
FIGS. 27-31 illustrate a common method of forming a cobalt silicide layer on an active-device region of a thin film semiconductor device. FIG. 27 illustrates an intermediate structure 400 comprising a semiconductor substrate 402 with a polysilicon layer 404 thereon, wherein the polysilicon layer 404 has at least one active-device region 406 formed therein with a thin dielectric layer 408 , such as tetraethyl orthosilicate—TEOS, disposed thereover. The dielectric layer 408 must be as thin as possible to reduce the height of the thin film semiconductor device. A contact opening 412 is formed, by any known technique, such as patterning and etching, in the dielectric layer 408 to expose a portion of the active-device region 406 , as shown in FIG. 28. A thin layer of cobalt 414 is applied over the dielectric layer 408 and the exposed portion of the active-device region 406 , as shown in FIG. 29. A high-temperature anneal step is conducted in an inert atmosphere to react the thin cobalt layer 414 with the active-device region 406 in contact therewith which forms a cobalt silicide layer 416 , as shown in FIG. 30 . However, dielectric materials, such as TEOS—tetraethyl orthosilicate, BPSG—borophosphosilicate glass, PSG—phosphosilicate glass, and BSG—borosilicate glass, and the like, are generally porous. Thus, the thin dielectric layer 408 has imperfections or voids which form passages through the thin dielectric layer 408 . Therefore, when the high-temperature anneal is conducted, cobalt silicide also forms in these passages. The cobalt silicide structures in the passages are referred to as patches 418 , as also shown in FIG. 30 . When the nonreacted cobalt layer 414 is removed to result in a final structure 422 with a cobalt silicide layer 416 formed therein, as shown in FIG. 31, the patches 418 also form conductive paths between the upper surface of the thin dielectric layer 408 which can cause shorting and current leakage on IC backend testing devices which leads to poor repeatability and, thus, poor reliability of the data from the testing devices.
Although such voids can be eliminated by forming a thicker dielectric layer 424 , the thicker dielectric layer 424 leads to poor step coverage of the cobalt material 426 in bottom corners 428 of the contact opening 412 , as shown in FIG. 32 . The poor step coverage is caused by a build-up of cobalt material 426 on the upper edges 432 of the contact opening 412 which causes shadowing of bottom corners 428 of the contact openings 412 . The result is little or no cobalt material 426 deposited at the bottom corners 428 of the contact opening 412 and consequently an inefficient silicide contact formed after annealing.
Step coverage can be improved by using filtering techniques, such as physical collimated deposition and low-pressure long throw techniques, which are used to increase the number of sputtered particles contacting the bottom of the contact opening. However, such filtering techniques are costly and the equipment is difficult to clean. Furthermore, filtering techniques also reduce the deposition rate of the cobalt material which reduces product throughput and, in turn, increases the cost of the semiconductor device. Moreover, using a thick dielectric layer is counter to the goal of reducing semiconductor device size. Finally, a thick dielectric layer eliminates the ability of the structure to be used as a backend IC probing device since the contacts are too small and too deep in the dielectric material. This is a result of dielectric material not being scalable. As device geometries get smaller, the thickness of the dielectric cannot be reduced without the potential of shorting and/or formation of patches. Thus, contact size must be increased to allow probe tips to fit in contacts, which is counter to the goal of reducing semiconductor device size.
Thus, it can be appreciated that it would be advantageous to develop a technique and a contact interface which is free from patch formations, while using inexpensive, commercially available, widely practiced semiconductor device fabrication techniques and equipment without requiring complex processing steps.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to methods of forming silicide interfaces for use with thin film devices and backend integrated circuit testing devices and structures so formed. The present invention is particularly useful when a porous dielectric layer is disposed between a silicon-containing substrate and a silicidable material deposited to form a silicide contact in a desired area. As previously discussed, dielectric layers may have imperfections or voids which form passages through the thin dielectric layer. Therefore, when the high-temperature anneal is conducted to form the silicide contact from the reaction of the silicidable material and the silicon-containing substrate, a silicide material may also form in these passages through the dielectric material. Such silicide material extending through these passages can cause shorting and current leakage. The present invention prevents the formation of silicide material through passages in the dielectric material by the application of a barrier layer between the dielectric material and the silicidable material.
In an exemplary method of forming a contact according to the present invention, a semiconductor substrate is provided with a polysilicon layer disposed thereon, wherein at least one active-device region is formed in a polysilicon layer. A thin dielectric layer is deposited or grown (such as by a thermal oxidation process) over the polysilicon layer and a layer of barrier material, preferably titanium nitride, is deposited over the thin dielectric layer.
A mask material is patterned on the barrier material layer and a contact opening is then etched through the barrier material layer and the thin dielectric layer, preferably by an anisotropic etch, to expose a portion of the active-device region. Any remaining mask material is removed and a thin layer of silicidable material, such as cobalt, titanium, platinum, or palladium, is deposited over the barrier material layer and into the contact opening over the exposed portion of the active-device region. A high-temperature anneal is conducted to react the thin silicidable material layer with the active-device region in contact therewith, which forms a silicide contact. The barrier material prevents the formation of silicide structures within voids and imperfections in the thin dielectric layer. The nonreacted silicidable material layer and remaining barrier material layer are then removed.
In an exemplary method of forming a testing contact used in backend testing of semiconductor devices, a silicon-containing substrate is provided having at least one contact projection disposed thereon. A first dielectric layer is deposited or grown over the substrate and the contact projection. A layer of polysilicon is then deposited over the first dielectric layer. A second dielectric layer is optionally deposited over the polysilicon layer and a layer of barrier material is deposited over the optional second dielectric layer, or over the polysilicon, if the optional second dielectric layer is not used.
A mask material is patterned on the barrier material layer. The barrier material layer and the optional second dielectric layer (if used) are then etched to expose the polysilicon layer over the contact projection, then any remaining mask material is removed. A thin layer of silicidable material is deposited over the barrier material layer and onto the exposed contact projection. A high-temperature anneal is conducted to react the thin silicidable material layer with the exposed portion of the polysilicon layer over the contact projection which forms a silicide layer. The nonreacted silicidable material layer and the remaining barrier material layer are then removed to form the testing contact.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly claiming that which is regarded as the present invention, the advantages of this invention can be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings in which:
FIGS. 1-8 are cross-sectional views of a method of forming a contact interface in a thin semiconductor structure according to the present invention;
FIG. 9 is a cross-sectional view of CMOS structures within a memory array of a DRAM chip formed by a method according to the present invention;
FIGS. 10-17 are cross-sectional views of a method of forming a testing interface according to the present invention;
FIG. 18 is a cross-sectional view of a testing interface according to the present invention with a chip-under-test disposed therein;
FIGS. 19-26 are cross-sectional views of another method of forming a testing interface according to the present invention;
FIGS. 27-31 are cross-sectional views of a method of forming a contact interface in a thin semiconductor structure according to a known technique; and
FIG. 32 is a cross-sectional view of the deposition of a metal layer in an opening in a thick dielectric according to a known technique.
DETAILED DESCRIPTION OF THE INVENTION
FIGS. 1-8 illustrate a method of forming a contact interface of the present invention. It should be understood that the illustrations are not meant to be actual views of any particular semiconductor device, but are merely idealized representations which are employed to more clearly and fully depict the formation of contact interfaces in the present invention than would otherwise be possible. Additionally, elements common between FIGS. 1-8 retain the same numerical designation.
Although the examples presented are directed to the formation of cobalt silicide contact interfaces, any metal or metal alloy which is capable of forming a silicide may be employed, including, but not limited to, titanium, platinum, or palladium.
FIG. 1 illustrates a semiconductor substrate 100 , such as a silicon-containing substrate, having a polysilicon layer 102 thereon, wherein at least one active-device region 104 is formed in a polysilicon layer 102 , with a thin dielectric layer 106 , such as TEOS, of a thickness of approximately 1 kÅ disposed over the polysilicon layer 102 . A layer of barrier material 108 , preferably titanium nitride deposited to a thickness of between about 100-150 Å, is deposited over the thin dielectric layer 106 , such as by PVD, as shown in FIG. 2 . Other potential barrier materials include tungsten nitride, tungsten silicon nitride, titanium silicon nitride, and the like.
A mask material 112 is patterned on the barrier material layer 108 , as shown in FIG. 3. A contact opening 114 is then etched through the barrier material layer 108 and the thin dielectric layer 106 , preferably by a dry etch such as reactive ion etching or the like, to expose a portion of the active-device region 104 , then any remaining mask material 112 is removed, as illustrated in FIG. 4. A thin layer of cobalt 116 is deposited, preferably by PVD, over the barrier material layer 108 and into the contact opening 114 over the exposed portion of the active-device region 104 , as shown in FIG. 5. A high-temperature anneal step, preferably between about 400 and 800° C., most preferably between about 450 and 600° C. for between about 5 seconds and 1 hour, is conducted in an inert atmosphere, preferably nitrogen containing gas, to react the thin cobalt layer 116 with the active-device region 104 in contact therewith which forms a cobalt silicide layer 118 , as shown in FIG. 6 . The barrier material layer 108 prevents the formation of cobalt silicide structures within voids and imperfections in the thin dielectric layer 106 . In particular, it has been found that a thin titanium nitride film acts as a good diffusion barrier for a thin TEOS dielectric layer. Further, it has been found that titanium nitride does not react with cobalt. Thus, cobalt silicide patch formations have been eliminated when titanium nitride is used as a barrier layer over a thin TEOS dielectric layer.
The nonreacted cobalt layer 116 is removed, preferably by a wet etch such as hydrochloric acid/peroxide or sulfuric acid/peroxide mixtures, wherein the barrier material layer 108 preferably acts as an etch stop, as shown in FIG. 7 . Preferably, the nonreacted cobalt layer 116 is etched in a dilute HPM (Hydrochloric acid/Peroxide Mixture) solution (typically, 1 volume of hydrochloric acid to 1 volume of peroxide to 5 volumes of water) for about 30 seconds at about 30° C. Such an HPM solution is preferred because its selectivity is greater than 10 4 for cobalt against cobalt silicide and titanium nitride.
As shown in FIG. 8, the remaining barrier material layer 108 is then removed, preferably by etching in an APM solution (Ammonia/Peroxide Mixture) solution (typically, 1 volume of ammonia to 1 volume of peroxide to 5 volumes of water) for between about 1 and 2 minutes at about 65° C. Such an APM solution is preferred because of its selectivity for titanium nitride against cobalt silicide and TEOS.
It is contemplated that the process of the present invention may be utilized for production of DRAM chips, wherein the contact interfaces are used in the MOS structures within a memory array of a DRAM chip. Such a MOS structure 200 is illustrated in FIG. 9 as a portion of a memory array in a DRAM chip. The MOS structure 200 comprises a semiconductor substrate 202 , such as a lightly doped P-type crystal silicon substrate, which has been oxidized to form thick field oxide areas 204 and exposed to implantation processes to form drain regions 206 and source regions 208 . Transistor gate members 212 , including a wordline 214 bounded by insulative material 216 , are formed on the surface of the semiconductor substrate 202 and thick field oxide areas 204 . A barrier layer 218 is disposed over the semiconductor substrate 202 , the thick field oxide areas 204 , and the transistor gate members 212 . The barrier layer 218 has bitline contacts 222 contacting the source regions 208 for electrical communication with a bitline 224 and, further, has capacitor contacts 226 contacting the drain regions 206 for electrical communication with memory cell capacitors 228 . Each of the bitline contacts 222 and capacitor contacts 226 may have silicide layer interfaces 232 , formed as described above, for reducing resistance between the bitline contacts 222 and the source regions 208 , and between the capacitor contacts 226 and the drain regions 206 . The memory cell capacitors 228 are completed by depositing a dielectric material layer 234 , then depositing a cell poly layer 236 over the dielectric material layer 234 .
FIGS. 10-17 illustrate a method of forming a testing contact used in backend testing of semiconductor devices. It should be understood that the illustrations are not meant to be actual views of any particular semiconductor device, but are merely idealized representations which are employed to more clearly and fully depict the formation of contact interfaces in the present invention than would otherwise be possible. Additionally, elements common between FIGS. 10-17 retain the same numerical designation.
FIG. 10 illustrates a substrate 302 having at least one contact projection 304 disposed thereon, preferably with a height of approximately 100 μm, wherein the substrate 302 and the contact projection 304 have a first dielectric layer 306 , preferably silicon dioxide, disposed thereover. The first dielectric layer 306 may be deposited by any known technique or, if silicon dioxide, may be grown on the surface of the substrate 302 by a thermal oxidation process. A layer of polysilicon 308 is deposited by any known technique over the first dielectric layer 306 . As shown in FIG. 11, a second dielectric layer 312 , such as TEOS or silicon dioxide, is deposited over the polysilicon layer 308 and a layer of barrier material 314 , preferably titanium nitride, is deposited over the second dielectric layer 312 , such as by PVD.
A mask material 316 is patterned on the barrier material layer 314 , as shown in FIG. 12 . The barrier material layer 314 and the second dielectric layer 312 are then etched, preferably by a dry etch such as reactive ion etching or plasma etching, to expose the polysilicon layer 308 over the contact projection 304 , then any remaining mask material 316 is removed, as illustrated in FIG. 13. A thin layer of cobalt 318 is deposited, preferably by PVD, over the barrier material layer 314 and onto the exposed contact projection 304 , as shown in FIG. 14. A high-temperature anneal step, preferably between about 400 and 800° C., most preferably between about 450 and 600° C. for between about 5 seconds and 1 hour, is conducted in an inert atmosphere, preferably nitrogen containing gas, to react the thin cobalt layer 318 with the exposed portion of the polysilicon layer 308 over the contact projection 304 which forms a cobalt silicide layer 322 , as shown in FIG. 15 .
The nonreacted cobalt layer 318 is removed, preferably by a wet etch, such as hydrochloric acid/peroxide or sulfuric acid/peroxide mixtures, wherein the barrier material layer 314 preferably acts as an etch stop, as shown in FIG. 16 . Preferably, the nonreacted cobalt layer 318 is etched in a dilute HPM (Hydrochloric acid/Peroxide Mixture) solution (typically, 1 volume of hydrochloric acid to 1 volume of peroxide to 5 volumes of water) for about 30 seconds at about 30° C.
As shown in FIG. 17, the remaining barrier material layer 314 is then removed, preferably etching in an APM (Ammonia/Peroxide Mixture) solution (typically, 1 volume of ammonia to 1 volume of peroxide to 5 volumes of water) for between about 1 and 2 minutes at about 65° C., and the remaining second dielectric layer 312 and polysilicon layer 308 are also removed, by any known technique. The cobalt silicide layer 322 is not disturbed by the removal of the remaining barrier material layer 314 or the removal of the second dielectric layer 312 and polysilicon layer 308 , as dry etches containing chlorine or fluorine will not etch cobalt silicide (i.e., CoF x and CoCl x are nonvolatile).
Structures such as illustrated in FIG. 17 are generally used for testing of flip-chips, wherein, as illustrated in FIG. 18, solder bumps 332 of a flip-chip 330 electrically contact the cobalt silicide layer 322 . The cobalt silicide layer 322 conducts electrical signals to and/or receives electrical signals from the flip-chip 330 through the solder bumps 332 .
FIGS. 19-26 illustrate another method of forming a testing contact used in backend testing of semiconductor devices. Elements common between FIGS. 10-17 and FIGS. 19-26 retain the same numerical designation.
FIG. 19 illustrates a substrate 302 having at least one contact projection 304 disposed thereon, wherein the substrate 302 and the contact projection 304 have a first dielectric layer 306 , preferably silicon dioxide, disposed thereover. A layer of polysilicon 308 is deposited by any known technique over the first dielectric layer 306 . As shown in FIG. 20, a layer of barrier material 314 , preferably titanium nitride, is deposited over the polysilicon layer 308 .
A mask material 316 is patterned on the barrier material layer 314 , as shown in FIG. 21 . The barrier material layer 314 is then etched to expose the polysilicon layer 308 over the contact projection 304 , then any remaining mask material 316 is removed, as illustrated in FIG. 22. A thin layer of cobalt 318 is deposited over the barrier material layer 314 and onto the exposed contact projection 304 , as shown in FIG. 23. A high-temperature anneal step, preferably between about 400 and 800° C., most preferably between about 450 and 600° C. for between about 5 seconds and 1 hour, is conducted in an inert atmosphere, preferably nitrogen containing gas, to react the thin cobalt layer 318 with the exposed portion of the polysilicon layer 308 over the contact projection 304 which forms a cobalt silicide layer 322 , as shown in FIG. 24 .
The nonreacted cobalt layer 318 is removed, preferably by a wet etch, such as hydrochloric acid/peroxide or sulfuric acid/peroxide mixtures, wherein the barrier material layer 314 preferably acts as an etch stop, as shown in FIG. 25 . As shown in FIG. 26, the remaining barrier material layer 314 and the remaining polysilicon 308 are removed.
Having thus described in detail preferred embodiments of the present invention, it is to be understood that the invention defined by the appended claims is not to be limited by particular details set forth in the above description as many apparent variations thereof are possible without departing from the spirit or scope thereof.
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Silicide interfaces for integrated circuits, thin film devices, and backend integrated circuit testing devices are formed using a barrier layer, such as titanium nitride, disposed over a porous, thin dielectric layer which is disposed between a silicon-containing substrate and a silicidable material which is deposited to form the silicide interfaces for such devices. The barrier layer prevents the formation of a silicide material within imperfections or voids which form passages through the thin dielectric layer when the device is subjected to a high temperature anneal to form the silicide contact from the reaction of the silicidable material and the silicon-containing substrate.
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TECHNICAL FIELD OF THE INVENTION
[0001] This invention refers to a multipurpose self-propelled agricultural machine with great soil clearing with a mechanism for fitting and lifting tools for tilling, sowing, and/or fertilizing, spraying, fumigating, and/or any other labors with other tools being fitted, in lands apt for cultivating and within the lines of existing crop whatever its stage of development, without damaging said crop.
BACKGROUND OF THE INVENTION
[0002] At present, it is not widely known by the public the existence of a multipurpose self-propelled agricultural machine with great soil clearing with the possibility of performing multiple agricultural activities, passing through the crop lines whatever its stage of growth, without damaging it, in order to perform labors such as sowing and/or fertilizing, spraying, and other labors according to the labor device being fitted.
OBJECT OF THE INVENTION
[0003] The object of this invention is described in this memory with the aid of the complementary attached drawings of a multipurpose self-propelled agricultural machine with great soil clearing, since the labors that may be performed vary with different tools being fitted. Its feature of great soil clearing makes it possible to pass through crop lines at any stage of growth.
[0004] This new multipurpose machine has been designed with the aim of improving productivity as from the technical point of view as well as ensuring the ecological conservation of soil. Since, given the possibility of passing among the crop lines or furrows of corn, sunflowers, wheat, sorghum, soy, etc, whatever their stage of development, it is possible to sow a new crop between the existing one or the same plant, or fertilize or spray the crop.
[0005] This advantage makes the difference with the other sowing machines and fertilizers, as well as the fact of being self-propelled. Therefore, this is an important advantage, since it permits to produce two crops in the same cycle with the aid of a self-propelled machine with a sowing and/or fertilization device that increases productivity, and, at the same time, it allows an optimal combination of cultures to preserve ecology.
[0006] This machine is characterized in that the sowing equipment and the hopper may be easily disassembled and therefore it may become a self-propelled fumigating and/or spraying machine comparable to any of the existing ones with the advantage of passing between the crop lines or furrows whatever their degree of growth without damaging them. This new multi-purpose machine has been designed for the producer to have an only self-propelled machine to perform the sowing and/or fertilization works, fumigation, and/or spraying or other thanks to the advantage of easily assembling and disassembling the different sowing and/or fertilization and spraying devices or any other device for another agricultural labor.
[0007] The feature of this self-propelled multipurpose agricultural great soil clearing machine of being easily disassembled adds the advantage of allowing its conversion into another machine.
SUMMARY OF THE INVENTION
[0008] This invention refers to a self-propelled multipurpose agricultural machine of a considerable power and great soil clearing with a mechanism for fitting and lifting tools for tilling, sowing and/or fertilizing, spraying, fumigating and/or any other labor according to the element being attached, for lands apt for cultivating between crop lines whatever the degree of growth of those crops, without damaging them.
[0009] It is not widely known by the public the existence of a self-propelled agricultural machine of great soil clearing with the capacity of performing several agricultural labors and passing between the lines of existing crops whatever their degree of growth, without damaging them, with the purpose of sowing and/or fertilizing, spraying and other labors according to the device being attached.
[0010] The object described in this memory, with the aid of the attached complementary drawings, refers to a multi-purpose self-propelled agricultural machine of great soil clearing, since the labors to be performed vary with the tools being attached. It is characterized in that it performs great soil clearing, which allows it to pass between the existing lines of crops at any stage of growth.
[0011] This new multi-purpose machine has been designed with the aim of improving productivity and preserving the land's ecology. As it may pass between the lines or furrows of corps such as corn, sunflowers, wheat, sorghum, soy, etc, whatever their stage of growth, this machine permits the sowing of another crop between those lines, or the same one, and, at the same time, fertilize or spray the crop.
[0012] This advantage makes it different from the rest of the existing sowing machines or fertilizers as well as the fact that it is self-propelled. Thus, this is a considerable advantage, since it permits to produce two crops in the same cycle, and allows the producer, with this self-propelled machine with a sowing and/or fertilization device, to increase productivity and yield, and, at the same time, make an optimal combination of crops to preserve the ecology. This machine is characterized in that the sowing and hopper equipment may be easily disassembled, therefore, it may become a self-propelled machine for fumigation and/or spraying purposes comparable to any of the existing ones, with the advantage that it may pass between the crop lines or furrows at any stage of growth without damaging it. This new multi-purpose machine has been designed for the producer to have an only self propelled machine for performing different labors such as sowing and/or fertilizing, fumigating and/or spraying, or any other thanks to the advantage of the easy assembling and disassembling of the different devices for sowing and/or fertilizing and spraying or any other device for any other labor.
[0013] The feature of the easy disassembly adds the advantage to convert it into another agricultural machine for any other labor according to the device being fitted, which, in turn, adds the multipurpose characteristic. Thus, it addresses the problem of agricultural labors that could not be performed before because there was no access to the crop line or furrow due to its stage of growth. Thanks to this multipurpose self-propelled machine, according to the device attached, access to crop line is guaranteed for performing any agricultural labor, as, for example, plowing the land, if a plough is attached, among other applications and uses. This is an advantage for the producer since, with a small inversion, they obtain more applications.
[0014] The features of novelty and practical use of this multipurpose, self-propelled agricultural machine of great soil clearing are the basis for obtaining the privilege of exclusivity sought in this patent application.
BRIEF DESCRIPTION OF DRAWINGS
[0015] In order to illustrate the object of this invention, 7 schematic drawings have been attached for one of the preferred modalities of use, as an example, in which:
[0016] FIG. 1 is the perspective view of the multipurpose, self-propelled agricultural machine of great soil clearing, which illustrates the general disposition of its elements.
[0017] FIG. 2 is the perspective view of the multipurpose, self-propelled agricultural machine of great soil clearing with the sowing and/or fertilizing kit attached showing the way in which it is assembled and the way to arrange the sowing bodies in order to pass between the crop lines without damaging the crop.
[0018] FIG. 3 Perspective view of the frame, which consists of a tubular structure of crossbars and crosspieces.
[0019] FIG. 4 Isometric drawing of the frame with its supporting legs and the lifting system for the labor tools.
[0020] FIG. 5 Perspective view of the lifting holder.
[0021] FIG. 6 A view of the holding in which the different tools are fixed.
[0022] FIG. 7 The fertilizer sowing machine's frame that consists of a tubular structure with two separate crossbars with a groove and its frame.
DETAILED DESCRIPTION OF THE INVENTION
[0023] FIG. 1 shows the high agricultural self-propelled machine with details of its elementary components, such as the frame ( 1 ), the power generation device ( 2 ), which consists of an internal combustion engine and hydraulic pumps, the interior ( 3 ) with its command posts, the hopper or deposit ( 4 ), the lifting mechanism ( 5 ) for bearing, dragging and lifting the relevant tools and the four wheels, which have a variable gauge, since the legs where they are attached are fixed to the frame by means of an adjustable displaceable system with a considerable diameter and the less width as possible.
[0024] The novelty of this machine arises from the fact that its is self-propelled performs a great soil clearing with a minimum contact with the land, for which purpose it has the following configuration, as may be seen in FIG. 2 : on the highly resistant frame ( 1 ) (complementary drawing in FIG. 3 ), there are four supporting legs, two rear ( 10 ) and two at the front ( 7 ), in the auxiliary complementary drawing in FIG. 4 there is the steering mechanism and the tiltable system ( 6 ) which absorbs deformations in the land, the legs and wheels ( 12 and 14 ), of a great diameter and minimum width, which are propelled by hydraulic engines ( 11 and 13 ). On this frame ( 1 ) lies the internal combustion engine ( 3 ) which is propelled with the hydrostatic pump of hydraulic transmission as well as the hydraulic pump for the requirements of the different labors. On the front of this engine are its cooling radiators and the hydraulic system's oil ( 4 ).
[0025] The assembled cab is shown in ( 5 ) for controlling and driving the machine, where the command post includes the seat, the wheel and the control for forward and backwards movements and the operation commands.
[0026] On the frame ( 1 ), behind the cab, there is the cradle for supporting the hopper ( 20 ). When the machine is used as a fertilizer sowing machine, the hopper of grains and solid fertilizers ( 8 ) is on the cradle ( 20 ), and the hopper may be divided in two for each product, or undivided for using only one product, and it has a good capacity, which provides a great autonomy.
[0027] The hopper has an air turbine ( 9 ) for the pneumatic transportation of grains and/or fertilizers from the container to the sowing devices, and, below, as a dosing system with hydraulic propelled finned tubes according to the machine's speed that may be regulated according to the dose to be applied.
[0028] In the back part of the frame ( 1 ), there is the lifting holder ( 15 ) (complementary drawing in FIG. 5 ); and, inside, the lifting itself ( 16 ), (auxiliary complementary drawing in FIG. 6 ), propelled by the compensated hydraulic cylinders ( 17 ) on which the labor tools to be used are hanged and fixed with bolts ( 19 ). In the same example of the machine used as fertilizing sowing machine, on the lifting ( 16 ) the sowing machine is fixed. The sowing machine consists of a frame ( 2 ), a frame ( 27 ), with supporting hooks ( 18 ), on which lie and hangs the lifting system. It also the fixation bolts ( 19 ) its compact functioning.
[0029] The sowing machine's frame is assembled with two separate beams (auxiliary complementary drawing FIG. 7 ) which have a groove for passing only one bolt for fixing the supporting leg and the sowing bodies ( 22 ). In the inferior part the cutting blade ( 26 ) is fixed, and, by means of a deformable parallelogram, the sowing body ( 23 ), with its relevant sowing discs, the leveling wheel, the seeds cap and the wheels for covering or forming the furrows are fixed in their relevant positions and pressure.
[0030] The groove all along the frame permits to fit the leg supporting the sowing body in any position. Thus, sowing can be made at any distance between the lines. On the sowing bodies ( 23 ) are placed the sowing pneumatic dosage measurer, that, with the controlled hydraulic propelling centrifuge turbine ( 21 ) and the pneumatic distributor ( 25 ) complete the pneumatic sowing system.
[0031] In addition, the seed dosing can also be made either by means of mechanic dosing or directly from the hopper. The advantage of this self-propelled machine with a sowing and/or fertilizing device is that the sowing and/or fertilization elements may be easily disassembled, and, therefore, by assembling the fumigation and/or spraying elements, it may become a self-propelled fumigator and/or sprayer.
[0032] When the self-propelled machine is used as a fumigator, on the supporting cradle ( 20 ), the liquids deposit is placed, and, instead of the turbine ( 9 ) a fumigation pump is placed which is propelled by the same hydraulic command of the air turbine. On the lifting ( 16 ) the fumigation boom is hung and fixed. Its technical features are similar to those available in the market.
[0033] In case any other tool is fitted, if it has to use the lifting system, it may be either fitted in a similar was as described above for the sowing machine and fumigator, or by means of a bolt, as in any tractor available in the market.
[0034] The fact that the tools kit may be easily disassembled has the advantage of facilitating its transportation, since the kit may me transported in a trolley designed for this purpose, that may be carried by the machine and respect the width permitted by the traffic law.
[0035] Those materials, shapes, colors and dimensions, and, in general, all those aspects that do not alter or change the essence of this invention, are independent from the object of this patent.
[0000] Schematic simplified view of FIG. 2 , with details of the following elements:
[0000]
1 . Tractor's frame.
2 . Sowing machine's frame.
3 . Diesel engine.
4 . Radiators.
5 . Cab.
6 . Tiltable and steering system.
7 . Front leg.
8 . Hopper for solid grains and fertilizers.
9 . Turbine for the pneumatic transportation of grains and fertilizers.
10 . Rear leg.
11 . Front hydraulic engine.
12 . Front wheel.
13 . Rear hydraulic engine.
14 . Rear wheel.
15 . Lifting holder.
16 . Lifting.
17 . Hydraulic cylinder that propels the lifting.
18 . The sowing machine's frame holding hook.
19 . Bolt for holding the sowing machine's trailer.
20 . Turbine for the pneumatic dosing device.
21 . Leg for holding the sowing trailer.
22 . Sowing body.
23 . Pneumatic grain dosing device.
24 . Pneumatic distributor.
25 . Blade for conventional or direct cuts.
After the above description of the nature and object of this patent, it is attested that the essential characteristics are shown in the next pages' claims:
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This invention refers to a self-propelled multipurpose agricultural machine of a considerable power and great soil clearing with a mechanism for fitting and lifting tools for tilling, sowing and/or fertilizing, spraying, fumigating and/or any other labor according to the element being attached, for lands apt for cultivating between crop lines whatever the degree of growth of those crops, without damaging them.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part patent application of Ser. No. 10/885,246, filed Jul. 6, 2004 for COAXIAL CABLE SPLICE CONNECTOR ASSEMBLIES by Randall A. Holliday, now U.S Pat. No. 7,059,900, and of Ser. No. 11/111,198, filed Apr. 20, 2005 now U.S. Pat. No. 7,159,695 for ADAPTER FOR COAXIAL CABLE WITH INTERCHANGEABLE COLOR BANDS by Randall A. Holliday, now U.S. Pat. No 7,156,695, and both incorporated by reference herein.
BACKGROUND
This invention relates to coaxial cable connectors; and more particularly relates to splice connectors for splicing the ends of coaxial cables together.
In coaxial cable installations, it is often necessary to splice the ends of two cables together. In the past, this has been done by exposing the conductor portions at the end of each cable and attaching special connectors to each end; and the special connectors in turn are then interconnected to opposite ends of a common connector body in such a way as to establish an electrical connection therebetween. Accordingly, there is presently an unmet need for a splice connector which will eliminate special end connectors on the end of each cable as well as to achieve a highly secure connection with minimal signal loss. This is of importance in home entertainment systems in creating improved connections or splicing between mini-coaxial cables as well as wall connections for the min-coaxial cables either manually or with the aid of a tool of the type customarily employed for crimping of a connector to a cable.
SUMMARY
It is therefore an object to provide for a novel and improved splice connector for coaxial cable installations.
It is another object to provide for a splice connector which is adaptable for use in different applications to establish secure interconnection between ends of a pair of min-coaxial cables to be joined together while avoiding the use of threaded fasteners.
It is another object to provide for a novel and improved method and means for interchangeably connecting different colored bands to a coaxial cable splice connector according to its intended application.
It is a further object to provide for a novel and improved splice connector conformable for use in the interconnection of a pair of min-coaxial cables in various applications, such as, wall mounts and which eliminates parts as well as requires less space in the installation or assembly of the cable and connector into a wall.
It is still another object to provide for a novel and improved connector body incorporating a starter guide extension for a pin conductor to facilitate blind insertion of the cable into one end of the connector body so as to be precisely centered for insertion of another pin conductor at the end of a second coaxial cable and wherein the connector body is readily conformable for use with different types of RGB connectors including but not limited to BNC, RCA and F-connectors.
In one aspect, a splice connector has been devised for electrically connecting pin or wire-like connectors at ends of each of a pair of cables, the connector comprising a tubular connector body including an insert with a socket end portion in combination with an adapter sleeve therein for insertion of opposite ends of the cables, the adapter including an electrically conductive portion to receive one of the conductors, the guide being axially advanced into centered relation to the adapter, and another of the conductors being inserted into a recessed portion at the socket end of the insert.
In another embodiment, the splice connector includes a special wall mounting clamp which is snap-fit with a tool onto a non-circular external surface portion of the connector body prior to mounting in the wall of an electrical outlet box, and an opposite end of the connector body protrudes from the wall mounting clamp for connection of the second cable with a color ring mounted on the opposite end in accordance with a standard color code for the industry so as to be visible externally of the wall plate. Typically, the RGB connector body would be a BNC, RCA or F-type socket connector and the second cable would be terminated with a corresponding male connector end in which the conductor extends from the male connector for insertion into a recessed portion at the socket end of the insert.
In a further embodiment, a corresponding type of splice connector body is employed with a resilient band or ring on its external surface which is color-coded to signify the intended application of the splice connector. The band can be attached to the body after one cable is connected to one end of the insert and the insert is crimped into position in the connector body, after which a second cable is inserted into the opposite end of the splice connector body to complete the connection to the selected electronic component. The color-coded band or ring is manually stretchable over the connector body and releasable to contract into close-fitting engagement with a groove on the body, and in wall mounting applications the band or ring is mounted in a groove externally of the wall mount installation so that it is visible after the installation is completed.
The above and other objects, advantages and features of the embodiments described will become more readily appreciated and understood from a consideration of the following detailed description when taken together with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view partially in section of an RCA connector assembly with a mini-cable inserted into the connector prior to the crimping operation;
FIG. 2 is an end view of the assembly shown in FIG. 1 ;
FIG. 3 is still another view of the assembly shown in FIGS. 1 and 2 after the connector body has been crimped onto the end of the cable;
FIG. 4 is an end view of the assembly shown in FIG. 3 ;
FIG. 5 is a longitudinal section view of a completed RCA splice connector assembly;
FIG. 6 is an exploded view of an extension tip for a mini-coaxial cable;
FIG. 7 is another exploded view of the assembled extension tip of FIG. 1 and an adapter sleeve;
FIG. 8 is another exploded view of a socket end portion prior to assembly onto the adapter sleeve;
FIG. 9 is a view in section of one embodiment of FIGS. 1 to 5 illustrating the initial stages of assembly of a mini-coaxial cable in relation to the RCA connector;
FIG. 10 is an exploded view in section of an RCA connector and a wall mount clip and color band;
FIG. 11 is an end view of the clip shown in FIG. 10 ;
FIG. 12 is a view partially in section of the form shown in FIG. 10 after the clip and color band have been mounted thereon;
FIG. 13 is an exploded perspective view of the splice connector assembly of FIGS. 10 to 12 and illustrating the extension of a first cable through an outlet box;
FIG. 14 is an exploded view partially in section of a BNC/RGB socket connector and wall mount clip and color band therefor;
FIG. 15 is a view partially in section of the connector of FIG. 14 after assembly of the wall mount clip and connection of a second cable;
FIG. 16 is a sectional view of a tool for mounting of the wall mount clip onto the connector body;
FIG. 17 is another sectional view of the tool of FIG. 15 in the closed position after mounting the clip on the connector body;
FIG. 18 is a front perspective view of one form of wall mount clip;
FIG. 19 is a rear perspective view of the clip shown in FIG. 18 ;
FIG. 20 is a front perspective view of another form of wall mount clip;
FIG. 21 is a rear perspective view of the clip shown in FIG. 20 ; and
FIG. 22 is an exploded perspective view of the tool and connector body of FIGS. 16 and 17 ;
DETAILED DESCRIPTION
FIGS. 1 to 22 illustrate embodiments of the present invention which are specifically adaptable for use with smaller diameter coaxial cables, customarily referred to as mini-coaxial cables which are on the order of 2.5 mm. to 4 mm. in diameter and are utilized with RGB splice connector bodies including but not limited to the BNC and RCA connector bodies.
In FIGS. 1 to 5 a wall mount splice connection is comprised of an RCA socket-type connector 10 having a barrel portion 12 which is enlarged at one end to provide a hexagonal surface portion 15 ; and an external circumferentially extending groove 13 is provided which may, for example, accommodate a color band B shown in FIGS. 10 and 12 and selected from one of a set of different colored bands which are furnished for the installation. Each band B may be composed of an elastic material and sized to fit over the connector body and then released to contract into the groove 13 . Thus, the user can identify the specific application after installing a given size and frequency of cable into the connector 10 . A series of grooves or slots 14 are provided on the hexagonal portion 15 for insertion of a seal to be hereinafter described.
An inner concentric sleeve 16 is composed of an electrically non-conductive material and mounted within the barrel 12 to receive an insert 30 , and the sleeve 16 extends from an end of the connector body 9 to a stop 10 ′ at the end of the barrel 12 . In addition, an external rib 11 is mounted on the barrel 9 for a purpose to be described; and the body 12 is in the form of a standard universal compression connector adapted to accommodate different sized cables and includes first and second tapered sleeves S 1 and S 2 in stepped relation to one another and interconnected to form a first external shoulder therebetween. The first sleeve S 1 also forms an external shoulder at one end which terminates in a groove 17 . The sleeve S 2 is provided with inner sealing ribs 18 , the sealing ribs 18 being axially spaced along the inner wall surface of the sleeve S 2 to effect a positive sealed engagement with a cable member inserted therein.
A crimping ring 20 is preassembled over the sleeve S 2 and is comprised of a main body 22 which is composed of a plastic material of limited compressibility, such as, DELRIN®. The leading end of the body 22 which fits over the sleeve S 2 has an inner, tapered wall surface which terminates in an internal shoulder 24 at its leading end, the end 24 being of a diameter slightly less than the external diameter of the distal end of the sleeve S 2 so that the shoulder 24 can be forced over the distal end until it extends beyond the sealing rings 18 and is then free to expand into engagement with the external surface of the sleeve S 1 . The body 22 is undercut along its outer surface to receive a reinforcing liner 25 which will fit snugly over the body 22 and limit expansion of the body 22 when it is subsequently advanced over the sleeve S 2 during the crimping operation to be described.
In order to splice the exposed ends of a pair of mini-coaxial cables M and M′ together, an insert 30 is shown in various stages of assembly in FIGS. 6 to 9 and is made up of an elongated tubular portion 32 of an electrically non-conductive material and which is undercut at one end 34 to receive the end of an adapter sleeve 36 of electrically conductive material. The sleeve 36 diverges into relatively thick arcuate end portions 38 which are separated by longitudinally extending slots 40 and have internal teeth 41 as illustrated in FIGS. 7 to 9 for the RCA connector version herein described. The opposite end of the tubular portion 32 has an inner wall surface 42 which diverges into a thin-walled annular end retainer 44 . The retainer 44 is longitudinally slotted at circumferentially spaced intervals to form an internal bore 48 . The tubular portion 32 receives a first socket end portion 50 which has a hollow, thin-walled cylindrical body 52 and which terminates in an annular end wall 54 . The socket end portion 50 fits snugly within the tubular portion 32 with the end wall 54 abutting inner shoulder 33 as best seen from FIGS. 7 , 8 and 9 .
Referring to FIG. 9 , the second socket end portion 56 includes a tubular end 58 provided with spaced longitudinal slots 59 and terminates in a nose 60 at an opposite end with longitudinal slots 62 dividing the end of the nose 60 into arcuate segments, and the hollow interior of the nose 60 communicates with a central bore 48 . When the nose 60 is advanced into the bore 64 , an external shoulder 66 on the nose will force the end retainer 44 to expand until the shoulder 66 moves into mating engagement with the end portion 46 .
Each of the mini-coaxial cables M and M′ is of standard construction and made up of a central conductor pin or wire E, a dielectric layer F, an outer braided conductive layer G, an insulating jacket H, and typically a foil layer is interposed between the layers G and H. The end of each cable M and M′ is prepared by removing a limited length of the jacket H and an even shorter length of the dielectric F so as to expose the end of the conductor pin or wire E; and the conductive layer G is peeled away from the dielectric layer F and doubled over the end of the jacket H. The socket end portion 50 is dimensioned to fit snugly over the exposed dielectric layer G with the pin E extending through the central bore 48 and nose 60 , as best seen from FIGS. 8 and 9 .
The assembled insert 30 , as shown in FIGS. 5 and 9 , is advanced through the hollow connector body 12 to center the second socket end portion 56 with respect to the inner sleeve 16 , and the socket end portion 56 will continue to advance until the slotted hollow end 58 abuts the end wall of the sleeve 16 and the end retainer 44 is seated in the body 9 .
It should be noted that the crimping ring 20 must be preassembled onto the end of the sleeve S 2 before the insert assembly 30 and the connector body 12 are assembled as described. Thus, when the crimping ring 20 is advanced from the open position shown in FIG. 1 to the closed position shown in FIG. 2 will exert a radially inwardly directed crimping force on the sleeves S 2 and S 1 in succession which will force the arcuate segments 38 into positive uniform crimping engagement with the braided layer G and jacket H.
Again, the insert 30 reinforces the conductor E and facilitates blind insertion of the cable M into the connector body 12 and assures alignment of the doubled-over portion of the braided layer G and underlying jacket H with the internal teeth 41 along the metallic segments 38 . Once the crimping ring 20 has been advanced to securely crimp the end of the cable M in position, the socket end portion 56 will act as a centering guide and extends through the sleeve 16 and terminates adjacent to the leading end of the barrel 10 ′.
FIGS. 10 to 13 illustrate the RCA socket connector 12 of FIGS. 1 to 9 and demonstrates its use or application in a wall mount assembly for an electrical outlet box P having a wall plate W, as shown in FIG. 13 . To this end, a mounting clamp 78 has a square inner body 80 provided with a hexagonal opening 82 which is dimensioned to fit snugly over the hexagonal nut portion 15 of the connector body 12 . The previously referred to band B is inserted into the slot 13 to designate the intended application, such as, a connection to a particular terminal on an electrical device, and the clamp 78 is mounted on the nut portion 15 so that the inner circumferentially spaced ribs 83 in the opening 82 are aligned with and inserted into the aligned slots 14 on the hexagonal nut portion 15 .
The clamp 78 shown in FIGS. 10-13 , 18 and 19 is open-sided and includes a pair of upper and lower clamping plates or legs 84 and 85 spaced apart a distance just greater than the spacing between upper and lower edges of the opening V in wail plate W so that the plates 84 and 85 have to be pressed toward one another at their free ends to enable insertion into the wall plate W until shoulder portions 86 and 87 on the upper and lower plates 84 and 85 move into abutting relation to the wall plate W. It will be noted that the upper clamping plate 84 is joined to the body 80 by inclined connecting portion 88 ; however, the lower mounting plate 85 extends at right angles to the base of the body 80 so as to establish the proper spacing or distance between the plates 84 and 85 in relation to the size of the square opening V in the wall plate W. Further, locating tabs 68 are offset both laterally and downwardly from opposite sides of the upper plate and lower tabs 69 are laterally offset only from opposite sides of the lower plate 85 in order to cooperate with the shoulders 85 , 86 in mounting the clamp 78 in the wall plate W. The modified form of clamp 78 ′ shown in FIGS. 20 and 21 is identical to that of FIGS. 18 and 19 but additionally includes opposite sidewalls 90 with shoulders 91 to engage the sides of the wall plate opening V.
DETAILED DESCRIPTION OF ALTERNATE FORMS
FIGS. 14 and 15 illustrate a BNC/RGB socket-end splice connector assembly for use with min-coaxial cables M and M′ which substantially corresponds to the RCA connecter body 12 and accordingly like parts are correspondingly enumerated. The end wall 10 ′ of the RCA connector is eliminated but an external flange 92 on the barrel facilitates connection of a standard BNC socket extension 94 on the end of the barrel with a bayonet slot which is slidable on the flange 92 in a conventional manner. Also, the extension 94 has an internal guide 96 with a tapered central opening 98 for insertion of the extension tip 100 of a pin conductor E′ of the cable M′. For the purpose of illustration but not limitation the cable M′ is mounted in a standard RGB connector, such as, Part No. FS RCA 1 RGB manufactured and sold by ICM Corp. Of Denver, Colo. Accordingly, the socket end 58 ′ is reduced in diameter from that of FIGS. 1 to 9 for snug-fitting engagement with the extension tip 100 on the end of the pin E′.
In use, the first cable M and its socket end 50 which are located in the electrical outlet box B are inserted into the connector body 12 and the crimping ring 20 is then advanced over the outer sleeves S 1 and S 2 to securely crimp the end of the cable M in position with the leading socket end portion 58 extending through the inner body or barrel portion 12 and terminating just short of the distal end of the barrel 12 . The clamp 78 is mounted on the connector with a compression tool T, as shown in FIGS. 16 , 17 and 22 and wherein the tool itself may be of the type set forth and described in U.S. Pat. No. 6,293,004 for LENGTHWISE COMPLIANT CRIMPING TOOL and U.S. Pat. No. 6,708,396 for UNIVERSAL CRIMPING TOOL, both assigned to the assignee of this patent application. Referring in particular to the U.S. Pat. No. 6,708,396, the tool is made up of an elongated body 102 having a yoke 104 at one end defining an end stop and in facing relation to a receiver 106 across a generally channel-shaped recess or opening 108 in the body 102 . The receiver 106 is in the form of a spring clip having circumferentially spaced resilient tabs and is mounted on the plunger 110 which is axially advanced through bushing 112 by a lever arm 114 . The receiver 106 is anchored to the end of the plunger by a shaft 116 having a base plate 118 , and when the shaft is inserted into a bore at the end of the plunger 110 the receiver 106 is sandwiched between the base plate 118 and the end of the plunger 110 .
Typically, the tool T is primarily intended for use with a plurality of different length tip extenders which can be releasably inserted into the receiver 106 for the purpose of engaging one end of a connector body and enable compression of a crimping ring onto the opposite end of the connector body into crimping engagement with a cable. For the purpose of mounting the clamp 78 onto the nut 15 , in place of the tip extender, a hollow cylindrical attachment 120 has one end 122 of slightly reduced diameter and of external concave configuration which is complementary to the receiver tabs for releasable, snug-fitting insertion into the receiver 106 , and a clip-engaging end 124 of increased outside diameter terminates in a circular rim 125 which is sized to engage the end surface 85 of the body 80 . The body 80 is loosely mounted on the end of the connector body 12 , as shown in FIG. 16 , so as to bear against the rim 125 . When the lever arm 114 is depressed from the open position shown in FIG. 16 to the closed position shown in FIG. 17 , the fitting 120 will force the clamp 78 to slide in an axial direction over the nut 15 until the corner ribs 83 are aligned with the slots 14 in the nut 15 . The lever arm 114 is then retracted and the connector body 10 along with the cable M is removed from the tool.
Preferring to FIG. 13 , after clamp 78 ′ is inserted into the opening V and the wall plate W is fastened to the electrical outlet box P, the color ring B is mounted in the external groove 13 so as to be visible externally of the wall plate after the installation has been completed. The cable M′ which is mounted in a standard BNC/RGB connector R, such as, Part No. FS BNC 1 RGB is inserted into the end of the connector body 12 with the conductor pin E′ and an extension tip 100 aligned for advancement into the socket end portion 58 , as shown in FIG. 15 . The socket end portion 58 is dimensioned to be slightly smaller than the extension tip 100 so that the slotted end 59 will undergo a slight expansion to receive the extension tip in snug-fitting relation and resist any tendency of the extension tip to accidentally escape from the socket end portion. The connection can be made in the same way as an RCA connector, for example, as illustrated in FIG. 5 .
It is therefore to be understood that while different embodiments and aspects are herein set forth and described, the above and other modifications may be made therein without departing from the spirit and scope of the invention as defined by the appended claims and reasonable equivalents thereof. For example, virtually any type or size of coaxial cable connector may be attached in place of the cable M′ into the min-coaxial cable splice connection assembly with or without the wall mount attachment.
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A splice connector assembly for electrically connecting or splicing mini-coaxial cable ends together includes an insert having opposed conductor pin-receiving sockets, a crimping member at one end of the body for crimping one cable end to the body with its conductor pin inserted into one of the sockets, and another cable end having its conductor pin inserted into the other socket, the assembly being conformable for use alone or in wall mount applications and with a wall mount clip color-coded to signify intended application of the splice connector for different uses and a tool for positioning the clip onto the connector body.
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BACKGROUND OF THE INVENTION
Various manually operated socket wrenches have been proposed heretofore in which the socket is driven from a rotatable handle through gears acting between them. For example, such wrenches are disclosed in the following U.S. pat. Nos.:
Wildmo 1,042,736; Gatewood 1,327,991; Mitchell
1,346,505; Owens 1,432,142; Kientz 1,648,134; and
Moritz, et al 2,478,935.
SUMMARY OF THE INVENTION
The present invention is directed to a novel and improved manually operated socket wrench having a selectively adjustable gear ratio in the gear reduction between the handle and the socket.
In the presently-preferred embodiment, the gear reduction has an intermediate shaft which is axially adjustable manually to change the gear ratio and a pivoted locking lever for locking this shaft axially in any one of several different axial positions. Different diameter gears on this intermediate shaft are engageable individually with corresponding gears on the socket shaft, depending upon the axial position of the intermediate shaft, so as to change the gear ratio in the gear reduction drive from the handle to the socket.
A principal object of this invention is to provide a novel and improved manually operated socket wrench having a selectively variable gear reduction acting between the handle and the socket.
Further objects of this invention will be apparent from the following detailed description of a presently-preferred embodiment, which is shown in the accompanying drawing in which:
FIG. 1 is a perspective view of a manual socket wrench in accordance with a preferred embodiment of the invention;
FIG. 2 is a planned view of the socket wrench of FIG. 1;
FIG. 3 is a longitudinal sectional view of the socket wrench.
Before explaining the disclosed embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown, since the invention is capable of other embodiments. Also, the terminology used herein is for the purpose of description and not of limitation.
DETAILED DESCRIPTION
The socket wrench 10 includes a handle 12, a socket 14, and a gear reduction 16 acting between the handle and the socket. The handle 12 in this embodiment is a conventional ratchet type handle for a socket wrench. It has a stud 18 which, in the use of a normal socket wrench, is inserted into a recess in a socket. However, in this embodiment, the stud 18 is inserted into a recess 20 in a member 22 affixed to the input shaft 24 of the gear reduction 16. The handle 12 includes a ratchet device (not shown) which is set by means of a lever 26 in a known manner.
The gear reduction 16 includes an input shaft 24 and an output shaft 25 mounted in a casing 28 for rotation. The input shaft 24 carries drive gear 30. The output shaft 25 carries driven gears 32, 34 and 36 of different diameters. The gear reduction 16 also includes an axially movable intermediate shaft 38 mounted on the casing 28 for rotation. The intermediate shaft 38 carries a corresponding plurality of intermediate gears 42, 44 and 46 of different diameters which can be engaged to a corresponding driven gear on the output shaft 25 in different axial positions of the shaft 38. Another intermediate gear 40 on shaft 38 remains engaged with drive gear 30 in all axial positions of shaft 38.
The shaft 38 is slidably received in an opening in a partition 48 of the casing 28, so that the shaft 38 can be axially shifted back and forth within the casing. The shaft 38 carries collars 50, 52, 54 and 56 for retaining the intermediate shaft 38 in different axial positions while permitting the shaft to rotate in each of the different axial positions. The collars can move through an opening in the casing 28. The intermediate shaft 38 is locked in a given axial position by engaging it with a locking lever 58 which has a recess 60 for snapping onto the shaft 38. The lever 58 may be made of yieldable plastic so that the recess 60 will have a snap fit on the shaft 38. The lever 58 is engaged between any two adjoining pairs of the collars 50, 52, 54 and 56 for locking the intermediate shaft in a given axial position. The inner ends of shafts 24 and 25 are also rotatably mounted in an opening in partition 48.
In the position of the shaft 38 shown in FIG. 3, gear 46 engages gear 36, and gear 40 engages gear 30. Thus, when the handle 12 is turned, the socket 14 will be driven with a predetermined gear reduction. When the shaft 38 is moved one step to the right as viewed in FIG. 3, gear 44 will engage gear 34, and gear 40 will still engage gear 30. Thus, by turning the handle 12, the socket 14 will be rotated with still a different gear reduction. It may be noted that the input gear 30 is wide enough to remain in engagement with the intermediate gear 40 in all three axial positions of gear 40. It may also be noted that a different number of gears and axial positions of the intermediate shaft 38 may be provided if desired.
Thus, the device 10 has different gear ratios in the gear reduction 16 for selecting the mechanical advantage between the handle 12 and the socket 14 as desired.
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A manual socket wrench having an adjustble gear reduction between the handle and the socket. The gear ratio may be adjusted by shifting axially a gear-carrying intermediate shaft and locking that shaft in the axial position to which it has been adjusted.
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RELATED APPLICATION
The present application claims priority benefit to the following applications, which contents are all incorporated by reference herein: U.S. Provisional Application No. 61/250,010 filed on Oct. 9, 2009 and Korean Patent Application No. 10-2010-0094780 filed on Sep. 29, 2010.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a wireless communication system and a user equipment (UE) providing wireless communication services, and more particularly, a method of minimizing an unnecessary MSI (MCH Scheduling Information) reception by a terminal (UE) during a reception of a MBMS (Multimedia Broadcast/Multicast Service) service in an Evolved Universal Mobile Telecommunications System (E-UMTS), a Long Term Evolution (LTE) system, and a LTE-Advanced (LTE-A) system that have evolved from a Universal Mobile Telecommunications System (UMTS).
2. Description of the Related Art
The LTE system is a mobile communication system that has evolved from a UMTS system, and the standard has been established by 3rd Generation Partnership Project (3GPP), which is an international standardization organization.
FIG. 1 is a view illustrating the network architecture of an LTE system, which is a mobile communication system to which the related art and the present invention are applied.
As illustrated in FIG. 1 , the LTE system architecture can be roughly classified into an Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) and an Evolved Packet Core (EPC). The E-UTRAN may include a user equipment (UE) and an Evolved NodeB (eNB, base station), wherein the connection between UE-eNB is called a Uu interface, and the connection between eNB-eNB is called an X2 interface. The EPC may include a Mobility Management Entity (MME) performing a control-plane function and a Serving Gateway (S-GW) performing a user-plane function, wherein the connection between eNB-MME is called an S1-MME interface, and the connection between eNB-S-GW is called an S1-U interface, and both connections may be commonly called an S1 interface.
A radio interface protocol is defined in the Uu interface which is a radio section, wherein the radio interface protocol is horizontally comprised of a physical layer, a data link layer, a network layer, and vertically classified into a user plane (U-plane) for user data transmission and a control plane (C-plane) for signaling transfer. Such a radio interface protocol can be typically classified into L1 (first layer) including a PHY layer which is a physical layer, L2 (second layer) including MAC/RLC/PDCP layers, and L3 (third layer) including a RRC layer as illustrated in FIGS. 2 and 3 . Those layers exist as a pair in the UE and E-UTRAN, thereby performing data transmission of the Uu interface.
FIGS. 2 and 3 are exemplary views illustrating the control plane and user plane architecture of a radio interface protocol between UE and E-UTRAN in an LTE system, which is a mobile communication system to which the related art and the present invention are applied.
The physical layer (PHY) which is a first layer provides information transfer services to the upper layers using a physical channel. The PHY layer is connected to the upper Medium Access Control (MAC) layer through a transport channel, and data between the MAC layer and the PHY layer is transferred through the transport channel. At this time, the transport channel is roughly divided into a dedicated transport channel and a common transport channel based on whether or not the channel is shared. Furthermore, data is transferred between different PHY layers, i.e., between PHY layers at the transmitter and receiver sides.
Various layers exist in the second layer. First, the Medium Access Control (MAC) layer serves to map various logical channels to various transport channels, and also performs a logical channel multiplexing for mapping several logical channels to one transport channel. The MAC layer is connected to an upper Radio Link Control (RLC) layer through a logical channel, and the logical channel is roughly divided into a control channel for transmitting control plane information and a traffic channel for transmitting user plane information according to the type of information to be transmitted.
The Radio Link Control (RLC) layer of the second layer manages segmentation and concatenation of data received from an upper layer to appropriately adjust a data size such that a lower layer can send data to a radio section. Also, the RLC layer provides three operation modes such as a transparent mode (TM), an un-acknowledged mode (UM) and an acknowledged mode (AM) so as to guarantee various quality of services (QoS) required by each radio bearer (RB). In particular, AM RLC performs a retransmission function through an automatic repeat and request (ARQ) function for reliable data transmission.
A Packet Data Convergence Protocol (PDCP) layer of the second layer performs a header compression function for reducing the size of an IP packet header which is relatively large in size and contains unnecessary control information to efficiently transmit IP packets, such as IPv4 or IPv6, over a radio section with a relatively small bandwidth. Due to this, information only required from the header portion of data is transmitted, thereby serving to increase the transmission efficiency of the radio section. In addition, in the LTE system, the PDCP layer performs a security function, which includes ciphering for preventing the third person's data wiretapping and integrity protection for preventing the third person's data manipulation.
A radio resource control (RRC) layer located at the uppermost portion of the third layer is only defined in the control plane. The RRC layer performs a role of controlling logical channels, transport channels and physical channels in relation to configuration, re-configuration, and release of Radio Bearers (RBs). Here, the RB denotes a logical path provided by the first and the second layers for transferring data between the UE and the UTRAN. In general, the establishment of the RB refers to a process of stipulating the characteristics of protocol layers and channels required for providing a specific service, and setting each of the detailed parameter and operation method thereof. The RB is divided into a signaling RB (SRB) and a data RB (DRB), wherein the SRB is used as a path for transmitting RRC messages in the C-plane while the DRB is used as a path for transmitting user data in the U-plane.
Hereinafter, a description of MBMS (Multimedia Broadcast/Multicast Service) will be given. In order to provide the MBMS service to a terminal (UE), in general, the wireless network may provide the MBMS Control Channel (MCCH) and the MBMS Traffic Channel (MTCH) for an MBMS service. The MCCH is used for transmitting MBMS control information to a terminal. The MTCH is used for transmitting the MBMS service to the terminal. The MBMS service is comprised of one session or a plurality of sessions, and only one session should exist for single time period (or duration). The wireless network may transmit an MBMS notification message in order to inform a session start of the MBMS service or a change of the MBMS control information. The notification message may be transmitted via the MCCH channel. Meanwhile, through the MBMS Indicator Channel (MICH), the wireless network notifies the terminal whether or not a MBMS notification message or control information for a specific service has been changed (modified).
In a conventional art, the terminal (UE) must read MCH scheduling information (MSI) in every MCH scheduling period in order to receive a certain MBMS service. However, since a MBMS data can be transmitted intermittently due to its traffic characteristic, in some case, some MBMS data may not be transmitted in the MCH scheduling period. Therefore, if the terminal always wakes in every MCH scheduling period to receive the MSI, this will cause an unnecessary battery consumption of the terminal.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a method of effectively receiving MBMS data transmission in a wireless communication system.
In order to achieve the foregoing object, the present invention may propose a method of receiving a point-to-multipoint service in wireless communication system, the method comprising: receiving scheduling information for the point-to-multipoint service, wherein the scheduling information includes sub-frame information and an indication, wherein the indication indicates a specific multicast channel scheduling period transmitting next scheduling information for the point-to-multipoint service; receiving the next scheduling information for the point-to-multipoint service based on the indication included in the scheduling information; and receiving the point-to-multipoint service according to the received scheduling information.
Further, in order to achieve the foregoing object, the present invention may propose a method of providing a point-to-multipoint service in wireless communication system, the method comprising: transmitting scheduling information for the point-to-multipoint service, wherein the scheduling information includes sub-frame information and an indication, wherein the indication indicates a specific multicast channel scheduling period transmitting next scheduling information for the point-to-multipoint service, wherein the transmitted scheduling information is used by a terminal in order to receive the next scheduling information for the point-to-multipoint service according to the indication included in the scheduling information; transmitting the point-to-multipoint service based on the transmitted scheduling information.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain the principles of the invention.
In the drawings:
FIG. 1 is a view illustrating the network architecture of an LTE system or an LTE-A system, which is a mobile communication system to which the related art and the present invention are applied;
FIG. 2 is an exemplary view illustrating the control plane architecture of a radio interface protocol between UE and E-UTRAN in an LTE system or an LTE-A system, which is a mobile communication system to which the related art and the present invention are applied;
FIG. 3 is an exemplary view illustrating the user plane architecture of a radio interface protocol between UE and E-UTRAN in an LTE system or an LTE-A system, which is a mobile communication system to which the related art and the present invention are applied;
FIG. 4 is an exemplary view illustrating a Multimedia Broadcast/Multicast Service (MBMS) channel structure;
FIG. 5 is an exemplary view illustrating a MBMS service reception procedure;
FIG. 6 is an exemplary view illustrating a structure of a MAC PDU (Medium Access Control Protocol Data Unit) used in an LTE or LTE-A system to which the present invention is applied;
FIG. 7 is an exemplary view illustrating a structure of a MAC sub-header for an variable-sized MAC CE (Control Element) and/or a MAC SDU (Service Data Unit) used in an LTE or LTE-A system to which the present invention is applied;
FIG. 8 is an exemplary view illustrating a structure of a MAC sub-header for an fixed-sized MAC CE (Control Element) used in an LTE or LTE-A system to which the present invention is applied;
FIG. 9 is an exemplary view illustrating a case that the UE receives unnecessary MSI during a reception of the MBMS service;
FIG. 10 is an exemplary view illustrating a case that the UE does not receives unnecessary MSI during a reception of the MBMS service by using a MSI skip indication according to the present invention; and
FIG. 11 is an exemplary view illustrating a structure of MSI MAC control element (CE) including the MSI skip indication according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
One aspect of this disclosure relates to the recognition by the present inventors about the problems of the related art as described above, and further explained hereafter. Based upon this recognition, the features of this disclosure have been developed.
Although this disclosure is shown to be implemented in a mobile communication system, such as a UMTS developed under 3GPP specifications, this disclosure may also be applied to other communication systems operating in conformity with different standards and specifications.
The present invention may be applied to a 3GPP communication technology, particularly to a Universal Mobile Telecommunications System (UMTS), system, and a communication device and method thereof. However, the present invention is not limited to this, but may be applied to every wire/wireless communication to which technical spirit of the present invention can be applied.
Hereinafter, the construction and operation of preferred embodiments according to the present invention will be described with reference to the accompanying drawings.
First, a detailed description for a MBMS (Multimedia Broadcast/Multicast Service) service will be given as follows.
FIG. 4 is an exemplary view illustrating a Multimedia Broadcast/Multicast Service (MBMS) channel structure.
In general, in order to effectively utilize radio resource(s), a MBMS service is transmitted via a common transport channel such as MCH (Multicast Channel). The MCH may be mapped with logical channels of MTCH (Multicast Traffic Channel) and MCCH (Multicast Control Channel), and may be mapped to a physical channel of PMCH (Physical Multicast Channel). Here, the MCH and PMCH is mapped in one to one relationship. Each MCH may be used to transmit a MSI (MCH Scheduling Information) indicating a MCH scheduling information at every MCH scheduling period. Here, the MSI may be in a form of a MAC control element.
FIG. 5 is an exemplary view illustrating a MBMS service reception procedure.
In general, in order to receive a MBMS service, the terminal (UE) may receive a MBMS data transmitted via a MTCH. Here, in order to receive MTCH, the MBMS service reception procedure illustrated as FIG. 5 must be performed. First, the UE may obtain MCCH scheduling information and MCCH configuration information by receiving system information (e.g., SIB 13 ) via a BCCH (Broadcast Control Channel). Here, the MCCH scheduling information may include information about a MCCH modification period and a MCCH repetition period. Further, the MCCH scheduling information may also include information indicating a particular sub-frame carrying the MCCH. The MCCH configuration information may indicate a type of MCS (modulation and coding scheme) used at the particular sub-frame. Namely, by receiving the system information (SIB 13 ), the terminal can properly receive the MCCH.
The MCCH is repeatedly transmitted in the repetition period, and it may be modified in the modification period. The MCCH may include information with respect to the all MBMS service providing by a corresponding cell, and may include scheduling information with respect to all MCH. Here, a MSI (MCH Scheduling Information) may be introduced to indicate that which MTCH is transmitted at which sub-frame. The MSI may be in a form of a MAC CE (Control Element), and may be transmitted at a first sub-frame in every MCH scheduling period. Therefore, the UE may obtain the MSI by receiving a first sub-frame in every MCH scheduling period, and then may receive the actual MBMS data at a corresponding sub-frame based on the obtained MSI.
As described above, the MSI (MCH Scheduling Information) may be transmitted in a form of a MAC CE (Control Element). The MAC CE may be referred to a control information generated in a MAC layer. The MAC CE may consist of a MAC SDU (Service Data Unit) and a MAC PDU (Protocol Data Unit). A header of the MAC PDU may include a MAC sub-header indicating a type and location of each MAC CE or MAC SDU. A payload of the MAC PDU may include a MAC CE or MAC SDU as indicated by MAC sub-header.
FIG. 6 is an exemplary view illustrating a structure of a MAC PDU (Medium Access Control Protocol Data Unit) used in an LTE or LTE-A system to which the present invention is applied.
Each field shown in FIG. 6 will now be described in detail as follows.
R (1 bit): Reserved field. E (1 bit): Extension field. It informs that whether or not an ‘F’ field and/or ‘L’ field is existed in a next byte. LCID (5 bit): Logical Channel ID field. It informs about a logical channel to which a corresponding MAC SDU belongs, or which information a corresponding MAC CE (MAC Control Element) includes. F (1 bit): Format field. It informs about the length of a subsequent ‘L’ field (either 7 bit or 15 bit). L (7 or 15 bit): Length field. It informs a length of a MAC CE or MAC SDU corresponding to the MAC sub-header. Here, the ‘F’ and ‘L’ field is not included in case with a fixed-sized MAC CE.
FIGS. 7 and 8 are exemplary views illustrating a structure of a MAC sub-header for a variable-sized MAC CE (Control Element) and a fixed-sized MAC CE used in an LTE or LTE-A system to which the present invention is applied. As illustrated in FIG. 8 , the ‘F’ and ‘L’ field are not existed for fixed-sized MAC CE.
In general, the MBMS (Multimedia Broadcast/Multicast Service) control information is provided on a logical channel, such as a MCCH (MBMS control channel). The MCCH may carry a single message which indicates the MBMS sessions that are ongoing as well as the (corresponding) radio resource configuration. The MCCH information may be transmitted periodically, using a configurable repetition period. Here, a change of MCCH information may only occur at specific radio frames, such as a modification period. Within the modification period, the same MCCH information may be transmitted a number of times, as defined by its scheduling that is based on a repetition period.
Usually, a MBMS service may be delivered through a MTCH (MBMS traffic channel) logical channel. The scheduling of MTCH may be dynamically changed, and this change information may be provided by MSI (MCH Scheduling Information). The eNB may periodically provide MSI (MCH scheduling information) at MAC layer as a MSI MAC CE (control element), where the MSI concerns the time domain scheduling of MTCHs within a MCH scheduling period. The MCH scheduling period may be called differently, e.g. MSAP allocation period, Dynamic Scheduling period, etc. The MSI may be placed at the beginning of each MCH scheduling period. The MSI may indicate the sub-frames that each MBMS data is actually transmitted in the MSAP allocation period. Based on the MSI, the UE may determine what sub-frames are used by which MTCH.
As aforementioned, though a MBMS service is ongoing, the actual data may be transmitted intermittently. However, the UE doesn't know when the MBMS data is transmitted, so the UE has to receive the MSI at every MCH scheduling period. As such, at a MCH scheduling period, the UE wakes up and receives the MSI to figure out whether the actual MBMS data is transmitted in this MCH scheduling period. If the MSI indicates that there is a data transmission, then the UE may receive the MBMS data in the sub-frames indicated in the MSI. But if there is no data transmission indicated in the MSI, the UE may sleep again until next MCH scheduling period, and in the next MCH scheduling period, the UE may wake up again and receive the MSI. For a MBMS service with very small data, the actual data transmission is performed only in a few MCH scheduling periods. In this case, such behavior of the UE is not efficient because the UE uselessly receives the MSIs even if there is no data transmission. It causes much waste of UE battery.
FIG. 9 is an exemplary view illustrating a case that the UE receives unnecessary MSI during a reception of the MBMS service.
As illustrated in FIG. 9 , if the UE (terminal) wants to receive a MBMS_x service, the UE should receive a MSI (MCH Scheduling Information), which is transmitted in a first sub-frame of MCH scheduling period of the MCH transmitting the MBMS_x service. Then, the UE may determine a specific sub-frame transmitting MBMS_x data transmission in this MCH scheduling period by checking the sub-frame information included in the MSI. Thereafter, the UE receives the MSI (MCH scheduling information) at every MCH scheduling period. However, if there is no data transmission in particular MCH scheduling period, a reception of the MSI in such MCH scheduling period is not necessary.
To avoid UE's receiving of MSIs at every MCH scheduling periods, a MSI skip indication (MSI) may be included in the MSI (MCH Scheduling Information) such that the MSI can indicate up to which MCH scheduling period the UE can sleep. In other words, the MSI may indicate the next MCH scheduling period where the MBMS data is transmitted.
The MSI (MCH Scheduling Information) of each MBMS service may be composed of sub-frame information (i.e. on which sub-frames the MBMS data is transmitted) and MSI (MSI skip indication) (i.e. next MCH scheduling period that the MBMS data is transmitted).
FIG. 10 is an exemplary view illustrating a case that the UE does not receives unnecessary MSI during a reception of the MBMS service by using a MSI skip indication according to the present invention.
As illustrated in FIG. 10 , the MSI (MSI skip indication) may indicate the offset to the next MCH scheduling period that the actual MBMS data is transmitted. That is, MSI=0 indicates the MBMS data is transmitted in the very next MCH scheduling period (UE shall receive the MSI at very next MCH scheduling period), MSI=2 indicates the MBMS data is transmitted in the third MCH scheduling period from this MCH scheduling period (UE can sleep next two MCH scheduling periods), and so on. As such, at the indicated MCH scheduling period, the UE may wake up and receive the MSI (MCH Scheduling Information), and may receive the MBMS data at the sub-frames indicated in the MSI. For example, if the MSI (MSI skip indication) is set to zero (i.e., MSI=0), then the UE should receive the MSI (MCH Scheduling Information) at the very next MCH scheduling period.
Further optimization may be possible in transmitting sub-frame information. That is, if there is no actual MBMS data transmission, the sub-frame information composed in the MSI (MCH Scheduling Information) may be omitted. For this purpose, a flag may be introduced in the MSI (MCH Scheduling Information) to indicate whether the sub-frame information is included or not in the MSI (MCH Scheduling Information). Here, a special value of MSI may be utilized instead of using of the flag. For example, if the flag or MSI special value is set to zero, this may indicate that there is a sub-frame information for this MBMS service, and if the flag or MSI special value is set to other values other than zero, this may indicate that there is no sub-frame info for this MBMS service. But, in this case, the MSI does not indicate the next MCH scheduling period but only indicates the current MCH scheduling period that the MBMS data is transmitted. Therefore, the UE should receive the MSI at the very next MCH scheduling period even if MSI=0. Therefore, there is a trade-off between one additional MSI reception and sub-frame information transmission.
The MSI (MCH Scheduling Information) may be transmitted as a MAC CE (Control Element). The MSI MAC CE may consist of a header and a payload. The MSI MAC CE header may further consist of a MSI identifier and a length field of the MSI MAC CE payload. Here, the Length field may not be needed if the MSI MAC CE payload has a fixed size or may be calculated by the number of ongoing service included in the MCCH (MBMS Control Channel). The MSI MAC CE payload may further consist of a set of MBMS ID, MSI, and sub-frame information for each ongoing MBMS service. The MBMS ID is usually implemented by a LCID (Logical Channel ID) of the MTCH (MBMS Traffic Channel).
As described above, it is possible to make sub-frame information transmitted only when there is actual data transmission. In this case, a flag is introduced in the MSI. Therefore, a field for the flag (i.e., ‘F’ field) may be also introduced in the MSI MAC CE. Further, the length field may be included in the MSI MAC CE because optional sub-frame information field causes variation of total length.
FIG. 11 is an exemplary view illustrating a structure of MSI MAC control element (CE) including the MSI skip indication according to the present invention. As illustrated in FIG. 11 , the MSI (MCH Scheduling Information) may be transmitted as a MAC CE (Control Element) via a MCH. The MSI MAC CE may consist of lists of all ongoing MBMS service. For example, the MSI MAC CE may consist of a set of MBMS ID for each MBMS service, a skip information (i.e., MSI (MSI Skip Indication), sub-frame information for each ongoing MBMS service, etc.
The present disclosure may provide a method of receiving a point-to-multipoint service in wireless communication system, the method comprising: receiving scheduling information for the point-to-multipoint service, wherein the scheduling information includes sub-frame information and an indication, wherein the indication indicates a specific multicast channel scheduling period transmitting next scheduling information for the point-to-multipoint service; receiving the next scheduling information for the point-to-multipoint service based on the indication included in the scheduling information; and receiving the point-to-multipoint service according to the received scheduling information, wherein the scheduling information is MCH scheduling information (MSI), the indication is a MSI skip indication, the indication includes a specific value indicating a number of skipping that the terminal should skip a reception of consecutive scheduling information, the scheduling information is received on a first sub-frame of a MCH scheduling period of a multicast channel (MCH) transmitting the point-to-multipoint service, the sub-frame information indicates a specific sub-frame transmitting the point-to-multipoint service within a MCH scheduling period, the scheduling information is received in a form of a MAC control element (CE), and the point-to-multipoint service is a Multimedia Broadcast/Multicast Service (MBMS) service.
It can be also said that the present disclosure may provide a method of providing a point-to-multipoint service in wireless communication system, the method comprising: transmitting scheduling information for the point-to-multipoint service, wherein the scheduling information includes sub-frame information and an indication, wherein the indication indicates a specific multicast channel scheduling period transmitting next scheduling information for the point-to-multipoint service, wherein the transmitted scheduling information is used by a terminal in order to receive the next scheduling information for the point-to-multipoint service according to the indication included in the scheduling information; transmitting the point-to-multipoint service based on the transmitted scheduling information, wherein the scheduling information is MCH scheduling information (MSI) and the indication is a MSI skip indication, the indication includes a specific value indicating a number of skipping that the terminal should skip a reception of consecutive scheduling information, the scheduling information is transmitted on a first sub-frame of a MCH scheduling period of a multicast channel (MCH) transmitting the point-to-multipoint service, the scheduling information is transmitted in a form of a MAC control element (CE), and the point-to-multipoint service is a Multimedia Broadcast/Multicast Service (MBMS) service.
Hereinafter, a terminal according to the present invention will be described.
A terminal according to the present invention may includes all types of terminals capable of using services that can transmits and/or receives data to and/or from each other in a wireless environment. In other words, a terminal according to the present invention may be used in a comprehensive meaning by including a mobile communication terminal (for example, user equipment (UE), portable phone, cellular phone, DMV phone, DVB-H phone, PDA phone, PTT phone, and the like), a notebook, a laptop computer, a digital TV, a GPS navigation, a potable gaming device, an MP3, other home appliances, and the like.
A terminal according to the present invention may include a basic hardware architecture (transmission and/or reception unit, processing or control unit, storage unit, and the like) required to perform the function and operation for effectively receiving the system information as illustrated in the present invention.
The method according to the present invention as described above may be implemented by software, hardware, or a combination of both. For example, the method according to the present invention may be stored in a storage medium (for example, internal memory, flash memory, hard disk, and the like, in a mobile terminal or base station), and may be implemented through codes or instructions in a software program that can be implemented by a processor (for example, microprocessor, in a mobile terminal or base station), and the like.
Although the present disclosure is described in the context of mobile communications, the present disclosure may also be used in any wireless communication systems using mobile devices, such as PDAs and laptop computers equipped with wireless communication capabilities (i.e. interface). Moreover, the use of certain terms to describe the present disclosure is not intended to limit the scope of the present disclosure to a certain type of wireless communication system. The present disclosure is also applicable to other wireless communication systems using different air interfaces and/or physical layers, for example, TDMA, CDMA, FDMA, WCDMA, OFDM, EV-DO, Wi-Max, Wi-Bro, etc.
The exemplary embodiments may be implemented as a method, apparatus or article of manufacture using standard programming and/or engineering techniques to produce software, firmware, hardware, or any combination thereof. The term “article of manufacture” as used herein refers to code or logic implemented in hardware logic (e.g., an integrated circuit chip, Field Programmable Gate Array (FPGA), Application Specific Integrated Circuit (ASIC), etc.) or a computer readable medium (e.g., magnetic storage medium (e.g., hard disk drives, floppy disks, tape, etc.), optical storage (CD-ROMs, optical disks, etc.), volatile and non-volatile memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmable logic, etc.).
Code in the computer readable medium may be accessed and executed by a processor. The code in which exemplary embodiments are implemented may further be accessible through a transmission media or from a file server over a network. In such cases, the article of manufacture in which the code is implemented may comprise a transmission media, such as a network transmission line, wireless transmission media, signals propagating through space, radio waves, infrared signals, etc. Of course, those skilled in the art will recognize that many modifications may be made to this configuration without departing from the scope of the present disclosure, and that the article of manufacture may comprise any information bearing medium known in the art.
As the present disclosure may be embodied in several forms without departing from the spirit or essential characteristics thereof, it should also be understood that the above-described embodiments are not limited by any of the details of the foregoing description, unless otherwise specified, but rather should be construed broadly within its spirit and scope as defined in the appended claims, and therefore all changes and modifications that fall within the metes and bounds of the claims, or equivalents of such metes and bounds are therefore intended to be embraced by the appended claims.
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The present invention relates to a wireless communication system and a user equipment (UE) providing wireless communication services, and more particularly, a method of minimizing an unnecessary MSI (MCH Scheduling Information) reception by a terminal (UE) during a reception of a MBMS (Multimedia Broadcast/Multicast Service) service in an Evolved Universal Mobile Telecommunications System (E-UMTS), a Long Term Evolution (LTE) system, and a LTE-Advanced (LTE-A) system that have evolved from a Universal Mobile Telecommunications System (UMTS), thereby preventing an unnecessary battery consumption of the terminal.
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FIELD OF THE INVENTION
[0001] The present invention is directed generally to medical devices and a method of vision screening, and more particularly to a pediatric vision screening system and method thereof that identifies a risk factor for amblyopia by measurement of microstrabismus.
BACKGROUND
[0002] Amblyopia is defined as poor vision in a structurally sound eye, and with a prevalence of 3-5%, it is the leading cause of vision loss in childhood. Amblyopia results from the inability of the brain to correctly interpret visual input due to deprivation or suppression. Anatomical risk factors for this condition include strabismus, anisometropia, cataract, certain forms of astigmatism, and hyperopia. Early detection and treatment is essential to prevent irreversible vision loss, but the risk factors can be difficult to detect. While comprehensive eye exams have been mandated in some areas, in most cases this solution is not economically feasible and tends to be instituted later than is optimal for amblyopia detection. Ideally, all children would be screened for amblyopic risk factors before age 4 or 5.
[0003] Practical vision screeners with sufficiently high testability, sensitivity, cost effectiveness, speed and specificity to reliably identify children at risk for amblyopia have been difficult to implement. Visual acuity tests have been the most widely used approach to vision screening. However, visual acuity testing may be no better than other screening tests for detecting amblyopia.
[0004] Guyton, Hunter, et. al., in U.S. Pat. No. 6,027,216 (hereby incorporated by reference) disclose a method of eye fixation monitoring using retinal reflections of polarized light to determine foveal fixation. This system was designed to detect both ocular focus and alignment. The object of the PVS is to provide a first-stage screening device that will differentiate between children in need of referral to an ophthalmologist and those not at risk, without attempting diagnosis. The output of the device is binary (either “refer” or “pass”) to facilitate use by non-ophthalmologists.
SUMMARY OF THE INVENTION
[0005] Generally, the present invention relates to medical devices and a method of vision screening, and more particularly to a pediatric vision screening system and method thereof that identifies a risk factor for amblyopia by measurement of microstrabismus.
[0006] An embodiment of the invention is directed to a method of patient screening for risk factors for amblyopia which includes the steps of illuminating the eye with polarized light, scanning the polarized light about the eye, capturing the retro-reflected light emanating back from the eye, analyzing the retro-reflected light to determine ocular misalignment; and calculating a metric to determine if the patient passes or fails the screening test thereby providing an indication that the patient may have a risk of amblyopia based on either strabismus, anisometropia, or any other eye condition that might interfere with the focus or alignment of the eyes.
[0007] Another embodiment of the invention is directed to a method of patient screening for risk factors for amblyopia which includes the steps of illuminating the eye with polarized light, scanning the polarized light about the eye, capturing the retro-reflected light emanating back from the eye, analyzing the retro-reflected light to determine ocular misalignment; and calculating a metric to determine if the patient passes or fails the screening test thereby providing an indication that the patient may have a risk of amblyopia derived from anisometropia. Another embodiment is to actually diagnose the condition of amblyopia rather than simply detect the risk for amblyopia. This can be used to follow the response to treatment, or to distinguish between patients who may have risk factors but have not developed the condition vs. patients with or without measurable risk factors who have developed the condition.
[0008] Another embodiment of the invention is directed to an apparatus for screening children for risk factors for amblyopia including an optical source for illuminating the eye, a polarizer to filter the output of the optical source, a scanner configured to direct the polarized light about the human eye at an oblique angle to the eye and at an angular frequency, an optical channel to capture the retro-reflected light from the eye and route the retro-reflected light to an optical detector, a calculator to compute the binocularity score based on the captured data, and an output device to indicate pass or fail if the binocularity score exceeds, or fails to exceed, a predetermined threshold.
[0009] The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description which follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
[0011] FIG. 1 is a cross sectional view of a human eye.
[0012] FIG. 2 is a flattened view of the posterior surface of the retina.
[0013] FIG. 3 is an enlarged view of the foveal area of the retina centered on the fovea.
[0014] FIG. 4 is a schematic representation of one embodiment of an optical instrument which may illuminate and subsequently detect polarization related changes in optical energy retro-reflected by a human eye.
[0015] FIG. 5A depicts an optical beam scanned in a circular pattern on the retina surface of a human eye encompassing the fovea region of the retina.
[0016] FIG. 5A-1 depicts the resultant electronic signal generated by scanning a human eye as depicted in FIG. 5A .
[0017] FIG. 5B depicts an optical beam scanned in a circular pattern on the retina surface of a human eye not encompassing the fovea region of the retina.
[0018] FIG. 5B-1 depicts the resultant electronic signal generated by scanning a human eye as depicted in FIG. 5B .
[0019] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0020] In general, the present invention is directed to medical devices and more particularly to a pediatric vision screening system that identifies a risk factor for amblyopia by measurement of microstrabismus. What follows is an overview of the optical measurement technique to detect ocular misalignment (strabismus).
[0021] The human eye has birefringent properties that may alter the state of polarization of an incoming optical beam traversing and ultimately retro-reflected from the retina region of the eye. The eye serves best as a retro-reflector when the eye is focused in the same plane, and nearly boresighted to, the incoming optical beam. In this case, an image of the source of light is formed on the central region of the retina, wherein the majority of the reflection in the eye takes place. Reflected light from this image is focused by the optics of the eye, and directed back toward the light source. Under certain conditions the polarization state of the incoming optical beam may be modified by interacting with naturally occurring birefringent elements within the eye. The nerve fibers in the retina of the eye have this birefringent property and may alter the polarization state of light impinging on them as a function of their incident orientation. These nerve fibers are arrayed in a characteristic pattern in the retina, specifically radiating outward from the fovea and converging to the optic nerve head. By analyzing polarization related changes in retro-reflected light from multiple retinal areas of both eyes either sequentially or simultaneously, characteristic birefringence signatures of portions of the retina can be identified which can be used to assess the direction of fixation of the eye.
[0022] FIG. 1 is a cross sectional view of the human eye 10 . Light incident upon the eye 10 enters through the transparent cornea 11 , passes through the pupil 12 , traverses the transparent crystalline lens 13 , and proceeds toward the fundus region of the eye, which is the inside aspect of the back of the eye, and passes through the retina 14 which lines the inner surface of the back of the eye. A central depression in the retina identifies the fovea 15 which is the area of the retina having the most acute vision. In viewing an object 16 , the brain uses the neck and eye muscles to aim the eye at the object. The direction of fixation is defined by the orientation of the axis of fixation 17 which connects the object 16 with the fovea 15 of the eye. When the eye is fixed on object 16 , an image of the object 16 is formed on the fovea 15 , and in a conjugate manner an image of the fovea 15 is projected onto the object 16 . Further, retinal nerve fibers (see FIG. 2 ; element 20 ) arising from all parts of the retina 14 travel along the surface of the retina 14 and converge to form the optic nerve 18 which conveys visual information from the eye to the brain.
[0023] FIG. 2 is a flattened view of the posterior surface of the retina 14 , showing the characteristic array of retinal nerve fibers 20 arising from all parts of the retina 14 and converging to the optic nerve head 21 . A large fraction of the retinal nerve fibers 20 arise from the foveal area where the concentration of neural elements is greatest and vision is most acute. As the retinal nerve fibers 20 leave the foveal area, they first travel in a radial direction away from the fovea 15 , then curve around as necessary to eventually reach the optic nerve head 21 .
[0024] FIG. 3 is an enlarged view of the foveal area of the retina 14 , centered on the fovea 15 , showing in greater detail the paths of the nerve fibers leaving the fovea 15 . The cell bodies 25 of the photoreceptor elements are in the very center of the fovea 15 . These cell bodies send nerve fibers called axons to communicate with a ring of ganglion cells 27 surrounding the fovea. The ganglion cells in turn give rise to long axons of their own, constituting the retinal nerve fibers 20 which travel to the optic nerve to communicate with the brain.
[0025] The short axons 26 of the photoreceptor cell bodies are called Henle fibers and emanate radially about the center of the fovea 15 . This radial array of Henle fibers, ending at the ring of ganglion cells 27 , has an overall diameter subtending approximately four degrees of visual angle. Besides the area surrounding the fovea, the only other location in the retina having a radial array of nerve fibers is the area around the optic nerve head. The optic nerve head 21 subtends a visual angle of about five degrees. Therefore, an area of the retina at least six or seven degrees in diameter would have to be examined in order to detect the radial pattern of nerve fibers surrounding the optic nerve head. Thus, the array of Henle fibers centered on the fovea 15 , because of its relatively small angular size and its precise radial symmetry, constitutes a unique arrangement of nerve fibers within the retina and, therefore, can serve as a marker for the fovea. Therefore, identification of the location of the array of Henle fibers also identifies the location of the fovea, being centered in the array of Henle fibers.
[0026] Both the Henle fibers and the other retinal nerve fibers are birefringent, with the optical axis of the birefringence being parallel to the direction of the fiber. In general, this birefringence will change the state of polarization of polarized light that passes across the nerve fiber. Polarized light striking the retina, therefore, will be changed in its state of polarization as it passes through the layer of nerve fibers. A small fraction of the light passing through the nerve fibers is reflected by deeper layers of the fundus to pass back through the pupil of the eye. This portion of the light thus double-passes the nerve fibers, and its state of polarization is changed twice by the birefringence of the nerve fibers.
[0027] FIG. 4 is a schematic representation of one embodiment of an optical instrument 400 which may illuminate and subsequently detect polarization related changes in optical energy retro-reflected by a human eye. An optical source 410 of energy may provide a linearly polarized output which is routed to the patient's eyes by relay optics. The optical source 410 may comprise, but is not limited to, a laser, a laser diode, a light emitting diode, or a broad-band optical source such as a halogen lamp with appropriate wavelength selective filter and linear polarizer. The output of the optical source 410 may be collimated by optical lens 420 and reflected by partial beamsplitter 430 . The optical beam reflected by partial beamsplitter 430 may be brought to a focus by condensing lens 440 at a location passing through aperture stop 445 and through the clear hole in mirror 450 , which may be oriented at 45 degrees relative to the incoming optical beam. The optical beam diverging from mirror 450 may be collimated by lens 460 enroute to mirror 470 . Mirror 470 may be tilted slightly off axis relative to incoming beam 461 such that reflected beam 471 returns to lens 460 displaced laterally a sufficient amount to be focused back onto the reflective surface of mirror 450 . The reflected beam 451 from mirror 450 is thereby incident upon the patient eyes 480 . The tilted mirror 470 may be rotated at angular frequency Ω (omega) about its axis of symmetry such that the incident optical beam 451 impinging upon the patient's eyes may map out a circular arc when ultimately focused on the patient's retina (see FIG. 5 ). The retro-reflected signal emanating from the patient's eye is reflected by mirror 445 and captured by lens 460 , i.e. captured in the sense that the retro-reflected signal is focused onto mirror 470 by lens 460 in such a manner as to retrace the path of incoming optical beams 451 , 471 , and 461 in this order eventually passing through the central hole in mirror 450 enroute to lens 440 . The reason that the retro-reflected signal retraces the illumination pathway is that the optical channel to capture the retro-reflected signal, composed primarily of mirrors 445 and 470 and lenses 460 and 440 , is that the illumination and capture optics are designed to be optically conjugate. After recollimation by lens 440 , a fraction of beam 441 is transmitted by partial beam splitter 430 enroute to knife edge reflecting prism 490 . Knife edge reflecting prism 490 spatially separates the retro-reflected signal from the patient's left and right eyes enroute to polarizing beam splitters 491 and 492 . Polarizing beam splitter 491 spatially separates the input beam from one eye (say, the right eye for example) into its' orthogonal x and y polarized components which are then focused by condensing lens 493 and 494 onto separate optical detectors 495 and 496 . In one embodiment of the present invention, the electronic outputs of optical detectors 495 and 496 are subtracted from one another to produce a differential polarization (X−Y) output insensitive to common mode specular reflections and non-polarized light. The optical beam incident upon polarizing beam splitter 492 , for the left eye, is processed similar to that of beamsplitter 491 outlined above. The output of optical detector 495 (and 496 ) may be analyzed in the frequency domain as outlined below to determine if the patient is fixated within an acceptable offset angle relative to the incident optical beam 451 .
[0028] With reference to FIGS. 5A and 5B , when the patient's eye is fixating directly at the incoming optical beam ( FIG. 4 , element 451 ), the circular arc mapped out by way of rotating mirror 470 , forms a circular arc 510 centered about the fovea region 520 and subtending approximately 3° of the patient's angular field of view. FIG. 5A depicts a view of the Henle fibers 530 radially expanding from the fovea region 520 . The Henle fibers 530 exhibit form birefringence wherein a principal axis of each fiber lines along the direction of its' radial path. When interacting with polarized light, each individual Henle fiber may alter the state of polarization of an incident linearly polarized beam by an amount depending upon the vector angle between the incident beam's polarization vector relative to the fiber's principal axis. Locations 1 through 4 in FIG. 5A represent one representative clockwise circular arc generated by rotating mirror 470 , wherein the arc encompasses the fovea region 520 . Similarly, FIG. 5A-1 maps in the time domain a one-to-one relationship of locations 1 through 4 in the circular arc to the electronic signal generated by the differential polarization output (X−Y) described earlier. As can be seen, in one revolution of the arc 510 about the fovea at angular frequency Ω, the time domain differential polarization signal (X−Y) generates a 2Ω (frequency doubled) component. In contrast, FIG. 5B depicts one representative clockwise circular arc generated by rotating mirror 470 , wherein the patient's eye is skewed off axis relative to the incoming optical beam 451 by a sufficient amount that the circular arc lies outside and does not encompass the fovea region 520 . In this case the one-to-one mapping in the time domain generates a time domain differential polarization signal (X−Y) at the same angular frequency Ω as the rotating mirror 470 . Given this, the differential polarization signal can be analyzed by frequency spectrum analysis to detect the presence, or absence; of the 2Ω frequency doubled signal which can be used to determine if the patient's eye is within a particular angular offset relative to the incoming optical beam 451 . For example, fast fourier transform techniques can be used to analyze the ratio of the 1Ω to 2Ω signal strength and a predetermined threshold for this ratio may be established in clinical trials to establish a pass/fail (“refer”) criterion for the test.
[0029] Instrumentation similar to that as described in FIG. 4 was used to evaluate the clinical performance of screening children for strabismus in a pediatric ophthalmology office setting. In one study 77 subjects between 2 and 18 years of age received “gold standard” orthoptic examinations, and were classified as “at risk” for amblyopia if strabismus or anisometropia (greater than 1.50 diopters difference) was present. Strabismus was sub-classified as variable or constant. The subjects were then tested with the instrumentation, a metric termed the binocularity score was calculated from the collected data (see equation below) and a pass or fail recommendation based upon the binocularity score was assessed. If the calculated binocularity score met or exceeded a predetermined threshold the subject was considered to have passed the screening test, otherwise the subject was considered to have failed the test and may be referred for follow-on testing (the failed subject being coined a “refer”). During central fixation, the incoming light beam to the eye (see FIG. 4 ; element 451 ) is focused by the eye and surrounds the fovea, as illustrated by the circle centered on the fovea shown in FIG. 5A . The device measures the number of times in a series of five measurements that the subject is able to binocularly fixate and produces a binocularity score as a percentage, wherein binocularity was calculated as:
[0000]
Binocularity
=
Number
of
bilateral
readings
Number
of
unilateral
readings
+
Number
of
bilateral
readings
×
100
%
[0000] Thus binocularity included only those readings in which at least one eye was fixating on the target. A subject who was relatively inattentive to the target did therefore not influence this parameter. If neither eye was centrally fixating, the reading was not included in the binocularity calculation. That is, a subject with 100 percent binocularity had bilateral alignment for every usable reading. Based on the results of a pilot study in adults, a binocularity score of greater than 60% was defined as “passing.”
[0030] In the first study, measurements were obtained from 77 children, 40 of whom had risk factors for amblyopia. Given the above criterion of a binocularity score greater than 60% as passing, all control subjects (n=37) received a passing score. Subjects were considered “control” if there they had no history of major ocular problems, and if both eyes met all of the following criteria: less than 3.25 diopters of myopia, less than 3.25 diopters of hyperopia, less than or equal to 1.50 diopters of anisometropia, and no strabismus. No separate criterion was set for astigmatism. Also, the results of this study yielded a binocularity score of less than 20% (a “refer”) for all subjects with constant strabismus and subjects with variable strabismus had binocularity scores ranging from 0% to 52% (also a “refer”). In addition, the 3 subjects pre-screened with anisometropia, and no strabismus, were all tested to have a binocularity score less than 10%. Follow-on testing with an additional 8 subjects pre-screened with anisometropia (7 of which with greater than 1.5 diopters difference), and no strabismus, yielded similar results with all subjects with anisometropia greater than 1.5 diopters having a binocularity score less than 60%. Given these results, the binocular retinal birefringence scanning technique may be directly sensitive to anisometropia, a risk factor for amblyopia. One possible explanation for these results may be that a sufficient focus in both eyes is a prerequisite for accurate fixation. To achieve a passing binocularity score, a subject must be able to focus and fixate on the target simultaneously with both eyes. However, a subject with anisometropia has one eye severely out of focus, which may impair the accuracy of fixation in that eye, leading to low binocularity Score. For example, the lack of fixation (meandering) may mimic the effect of lack of binocular alignment, but the scores on successive scans may be substantially different from each other. This may give clues that the risk factor is not binocular alignment but anisometropic induced meandering. For the screener, it does not matter. The goal is to rapidly identify subjects at risk for further evaluation. An acuity test given to a small group of selected subjects, who are suspected of being at risk for amblyopia is far simpler and more cost effective than testing every subject for acuity. This effect may be understood by examining the binocularity score equation shown below
[0000]
Binocularity
=
Number
of
bilateral
readings
Number
of
unilateral
readings
+
Number
of
bilateral
readings
×
100
%
[0031] One possible explanation is that the defocused spot on the retina in the anisometropic eye is sufficiently large so as to generate a significant amount of 1Ω signal at the mirror scanning frequency (see FIG. 5B ) during the cyclical scans so as to be designated as a unilateral reading (i.e., one good reading via the 2Ω signal from the in-focus eye). The large 1Ω (unilateral) term may directly drive down the binocularity score leading to the patient being “referred” to follow-on treatment. Alternatively, the anisometropic eye, unable to effectively focus, may wander throughout the procedure, generating a mixture of 2Ω signal while on or near axis, but generating a sufficient amount of 1Ω signal while wandering off axis to bias the result to a unilateral score, again driving down the binocularity score leading to the patient being “referred”. The present invention also contemplated the use of statistical analysis techniques applied to multiple determinations of the binocularity score as described above. Here, the protocol established above may be repeated multiple times and a mean and standard deviation may be calculated from the data set of individual binocularity scores. This test protocol may be useful in determining if eye wandering, whether random or induced by lack of fixation via an anisometropic eye, may influence the repeatability of the binocularity score. Furthermore, statistical non repeatability may itself set a threshold for identifying the patient as having a risk factor for amblyopia. For example, if the deviations in the binocularity scores vary by more than 2 standard deviations from the mean binocularity score, the patient may be indicating a probability of a risk factor for amblyopia. An alternative criterion may be, if the standard deviation of repetitive binocularity scores exceeds a predetermined clinically established threshold, the patient may be indicating a probability of a risk factor for amblyopia.
[0032] The instrumentation as described in FIG. 4 may also be designed with additional optical components that can assess the patient's ability to fixate and focus on a target. The focus detection characteristics of the instrumentation have been published elsewhere (see Hunter et. al., “Automated detection of ocular focus”, Journal of Biomedical Optics, 2004, 9:1103-1109) which is incorporated in its entirety herein by reference. However, given the above results, it may be possible to screen children for risk factors for amblyopia by measurement of microstrabismus alone, without the need for simultaneous or follow-on visual acuity/focusing data. As a result, it is possible to determine subjects at risk of amblyopia by testing for binocular misalignment (strabismus) as set forth above, but without the need to explicitly test for anisometropia (focal differential between eyes). This permits the development of a faster and cheaper screening device than was heretofore possible. Given this, a single test (binocular retinal birefringence scanning) may directly identify one risk factor for amblyopia and indirectly identify another (anisometropia); the device required may thus be simpler than first imagined. Furthermore, because mass screening must be done quickly, by using one test, the time required to achieve results may be reduced. In future embodiments of screening devices, optimization of this single test will undoubtedly result in even faster screening with higher patient throughput.
[0033] In some cases, the binocularity score returned to normal after treatment of amblyopia improved visual acuity to within the normal range. In other cases, patients with potential risk for amblyopia (but no amblyopia) had normal binocularity scores. This suggests that the detection of microstrabismus in association with amblyopia may diagnose the condition of amblyopia rather than simply detecting conditions that place the patient at risk for amblyopia.
[0034] As noted above, the present invention is applicable to medical devices and is believed to be particularly useful for screening children (pediatric) for risk factors for amblyopia because this screening technique requires very little co-operation of the patient and no patient response or interaction is required. This is particularly advantageous in pediatric screening of very young children. The present invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention as fairly set out in the attached claims. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the present specification. The claims are intended to cover such modifications and devices.
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Generally, the present invention relates to medical devices and a method of vision screening, and more particularly to a pediatric vision screening system and method thereof that identifies a risk factor for amblyopia or diagnoses amblyopia by measurement of microstrabismus. An embodiment of the invention is directed to a method of patient screening for risk factors for amblyopia which includes the steps of illuminating the eye with polarized light, scanning the polarized light about the eye, capturing the retro-reflected light emanating back from the eye, analyzing the retro-reflected light to determine ocular misalignment; and calculating a metric to determine if the patient passes or fails the screening test thereby providing an indication that the patient may have a risk of amblyopia based on either strabismus or anisometropia. The method is effective at detecting amblyopia related to focusing problems without the measuring the focus of the eye directly.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to window blinds of the type having tilting shade elements, such as the slats in a venetian blind.
[0003] 2. Description of the Related Art
[0004] Venetian blinds are one type of popular window covering. These blinds have a headrail, a bottom rail, and ladders extending between the bottom rail and the headrail that support a series of slats. Lift cords extend from the bottom rail into the headrail for raising and lowering the blind. The slats are tilted by movement of the ladders.
[0005] The slats can be raised to a fully open position, lowered to cover the entire window and tilted vertically to a fully closed position or lowered to a fully lowered or partially lowered position with the slats tilted at a selected orientation between vertical and horizontal. In a venetian blind the spacing between slats does not exceed the width of the slats and is usually less than the width of the slats. Such spacing is required so that the blind will fully cover the window when the slats are tilted to a vertical or near vertical position. Because of this spacing there are no gaps between the slats when they are in a fully tilted vertical or near vertical position.
[0006] Although the slats in most venetian blinds are wood, aluminum or plastic, it is known to make fabric slats. One example of a fabric slat is disclosed in U.S. Pat. No. 5,829,506 to Zorbas. Like wood, aluminum and plastic slats, fabric slats are hung on ladders or attached to ladder rungs and may have transverse stiffeners. Venetian blinds having fabric slats operate in the same manner as venetian blinds having wood, aluminum or plastic slats.
[0007] Kandel in U.S. Pat. No. 3,388,490 discloses a venetian blind having a fringe attached to one edge of each slat. The fringe extends to the next adjacent slat covering the space between the slats for privacy but allowing air to pass. Nien discloses a venetian blind having a mesh fabric attached to either or both longitudinal edges of the slats in United States Published Patent Application No. 2004/0016693. Like the other venetian blinds in the prior art the spacing between adjacent slats in the blinds disclosed by Kandel and Nien does not exceed the width of the slat. Consequently, when the slats are moved to a fully tilted, vertical or near vertical position there will be no space between adjacent slats through which light may pass. Therefore, these blinds provide the same type of light control as a conventional venetian blind.
SUMMARY OF THE INVENTION
[0008] I provide a window covering having a headrail, two or more lift cords extending from the headrail and several slat-like shade elements of selected width positioned sequentially below the headrail. Each shade element may have apertures through which the lift cords pass. Unlike a conventional venetian blind, adjacent shade elements in the present invention are spaced apart a greater distance than the width of the shade element or slat. The shade elements are substantially parallel to one another and oriented transverse to the lift cords. A flap is attached to one or both longitudinal edges of each shade element. The width of each shade element plus the width of the flap is not less than the spacing between adjacent shade elements. When the shade elements are in a closed position the lower edge of one flap is opposite or abuts the upper edge of an adjacent shade element so that there is no gap in the window covering through which light may pass. When the shade elements are in an open position, the lower edge of the flap is spaced apart from the adjacent shade element. Movement of the shade elements is controlled by a first cord or cords attached to one longitudinal edge of each shade element and extending into the headrail and a second cord or cords attached to the opposite longitudinal edge of each shade element. In one embodiment the upper end of the each cord is fixed to the headrail. Pulling or releasing the second cords raises or lowers the longitudinal edge of the shade elements to which the second cords are attached closing or creating a gap between the shade elements and adjacent flaps. In another embodiment both the first cords and the second cords are movable relative to the headrail. Therefore, either or both longitudinal edges of the shade elements can be raised or lowered. As the shade elements move the flaps remain in a substantially vertical position such that the shade element can be said to fold relative to the flap. One could connect both cords to a drum or shaft which when rotated will move the edges of each shade element in opposite directions.
[0009] In addition to the first and second cords that are attached to the longitudinal edges of the shade elements, lift cords extend from the headrail to the lowermost shade element or the bottom rail, if a bottom rail is present. The lift cords raise and lower the shade elements just as the lift cords in a venetian blind raise or lower the slats.
[0010] The shade elements may be wood, aluminum, woven wood or vinyl, but preferably are fabric. The flaps also are preferably fabric, but they could be a woven wood or film. In one embodiment the shade elements and flaps are the same fabric. In another embodiment two flaps are provided, one flap being a mesh fabric through which light may pass and the second fabric being an opaque material which blocks light.
[0011] One may also configure the present shade as a top down, bottom up shade. In one embodiment of this type of shade all the cords pass through cord locks allowing the shade elements to be lowered and stacked on a bottom rail or window sill. Another embodiment of a top down, bottom up shade uses an intermediate rail. The cords that attach to the edges of the shade elements are attached to or pass through the intermediate rail.
[0012] One may provide a panel or two panels of sheer material extending from the headrail. The panel of sheer material can be used in addition to or in place of the cords that are attached to the longitudinal edges of the shade elements.
[0013] Other objects and advantages of the present window covering will become apparent from certain present preferred embodiments thereof shown in the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a perspective view of a first preferred embodiment of the present invention in a fully lowered, first open position.
[0015] FIG. 2 is a perspective view of the embodiment of FIG. 1 in a fully lowered, second open position.
[0016] FIG. 3 is a perspective view of the embodiment of FIG. 1 in a fully lowered, closed position.
[0017] FIG. 4 is a side view of the embodiment of FIG. 1 in the first open position.
[0018] FIG. 5 is a side view of the embodiment of FIG. 1 in a fully lowered, closed position.
[0019] FIG. 6 is a perspective view of a second preferred embodiment of the present invention in a fully lowered, fully open position.
[0020] FIG. 7 is a perspective view of the embodiment of FIG. 6 in a fully lowered, first closed position.
[0021] FIG. 8 is a perspective view of the embodiment of FIG. 6 in a fully lowered, second closed position.
[0022] FIG. 9 is a perspective view of a third present preferred embodiment of the invention in a fully lowered, fully open position.
[0023] FIG. 10 is a side view of a preferred embodiment in a fully lowered, first closed position.
[0024] FIG. 11 is a side view of the upper portion of the embodiment shown in FIG. 9 .
[0025] FIG. 12 is a front view of a fourth present preferred embodiment in a fully lowered closed position.
[0026] FIG. 13 is a front view of the embodiment of FIG. 12 in a lowered open position.
[0027] FIG. 14 is a front view of an upper portion of a sixth present preferred embodiment, which is similar to the embodiment shown in FIGS. 9, 10 and 11 .
[0028] FIG. 15 is a perspective view of a seventh preferred embodiment of the present invention in a fully lowered, first open position.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0029] A first present preferred embodiment of my window covering is shown in FIGS. 1 through 5 . This window covering 1 is comprised of a headrail 6 , a plurality of operable shade elements 2 , two first cords 3 , two second cords 4 and two lift cords 5 , all of which extend into the headrail 6 . The shade elements 2 could be wood, woven woods, aluminum, vinyl or other plastic, but preferably are fabric or film. Any fabric that has traditionally been used in a window coverings could be used including natural materials, such as silk, cotton and linen, synthetic materials such as polyester, rayon and nylon, or a blend of natural and synthetic materials. The fabric could be woven or non-woven. Preferably the material has a weave that is sufficiently tight so that light does not pass through the material. Each shade element 2 has a first longitudinal edge 11 to which a first stiffening rod 21 is attached, and a second longitudinal edge 12 to which a second stiffening rod 22 is attached. The rods 21 and 22 extend the full length of the operable shade element 2 . A flap 7 extends from the first longitudinal edge 11 of the shade element 2 . The flap may be the same material as the shade element. Accordingly, a third stiffening rod 23 is provided along the lower edge or free edge 13 of the flap 7 . Preferably the flaps 7 and the shade elements 2 have the same width. That width preferably is between about 2 inches and 6 inches (5 cm to 15 cm) and most preferably is 4 inches (about 10 cm). The spacing between adjacent shade elements is always greater than the width of the shade element and is not more than the width of the shade element plus the width of the flap.
[0030] In the first present preferred embodiment, the upper ends of the two first cords 3 are fixed to the headrail 6 . These cords are also attached to the first longitudinal edge of each shade element 2 . In an alternative embodiment the first cord may be connected to a shaft 16 shown in dotted line in FIG. 1 or other operating mechanism within the headrail 6 . The second cords 4 are attached to the opposite longitudinal edge 12 of each shade element 2 . The second cords 4 pass through a cord lock 8 in the headrail 6 . Pulling the second cords 4 will raise the second longitudinal edge 12 of the shade elements from the position shown in FIG. 1 to the fully closed position shown in FIGS. 3 and 5 . Releasing cords 4 from the cord lock 8 will enable the second longitudinal edge of the shade elements to fall to the second open position shown in FIG. 2 . Of course, one could raise or lower the second longitudinal edge to any selected position intermediate the second open position shown in FIG. 2 and the fully lowered, closed position shown in FIG. 3 . Accordingly, the size of the gap between shade elements and adjacent flaps is determined by how much the edge of the shade element 2 is raised. If desired, one could fix the upper ends of cords 4 to the headrail and pass cords 3 through the cord lock 8 . Then the shade would be moved to a fully lowered, closed position by lowering the first longitudinal edges of each shade element. One could also raise the first longitudinal edges of the shade elements so that the shade elements are positioned as shown in FIG. 4 . Yet, another alternative is to connect both the first cords 3 and the second cords 4 to a shaft 16 in a manner so that both edges of the shade elements and rods 21 and 22 would move in opposite directions as the shade is turned. As the shade elements 2 tilt the flaps 7 remain in a vertical orientation. Hence, the shade elements 2 could be said to fold relative to the flaps 7 .
[0031] Lift cords 5 extend from the bottom rail 10 through the shade elements 2 , through the headrail 6 and a cord lock 9 in the headrail. Pulling the lift cords 5 will raise the bottom rail 10 and shade elements 2 . If desired the lift cords could be connected to the lowermost shade element and the bottom rail would then not be present. The lift cords 5 may pass through the center of the shade elements 2 or through loops extending from the first cords or the second cords. If desired one could wind the lift cords on a shaft within the headrail and use a motor or cord loop to rotate the shaft thereby raising or lowering the shade.
[0032] In the second present preferred embodiment 20 shown in FIGS. 6, 7 and 8 , two flaps 24 and 25 are attached to each shade element 26 . Each shade element has a stiffening rod 21 or 22 on each longitudinal edge. A stiffening rod 23 is also provided in the free edge of each flap 24 , 25 . Although both flaps 24 and 25 could be same material, I prefer that one flap 24 be an opaque material through which light does not pass and the second flap 25 be a mesh or other light transmissive material. Consequently, when the shade elements 26 are tilted to the position shown in FIG. 7 , the opaque flaps 24 close the gaps between adjacent shade elements allowing little or no light to pass through the window covering. However, when the shade elements 26 are tilted in the opposite direction, shown in FIG. 8 , the light transmissive flaps 25 will be between adjacent shade elements. Therefore, light may pass through the light transmissive flaps 25 between adjacent slats. Lift cords 27 extend from a bottom rail 30 through the shade elements and into the headrail 6 . The lift cords 27 pass through a cord lock 9 . Pulling the lift cords will raise the bottom rail 30 lifting the shade elements. As in the first embodiment, a first pair of cords 28 is attached to one edge of each shade element and a second pair of cords 29 is attached to the opposite edge of each shade element. These cords 28 , 29 function in the same manner as cords 3 and 4 in the first embodiment.
[0033] Although I prefer that each flap 24 , 25 be a single material having the same opacity throughout other variations are possible. Two or more materials could be used in a single flap such that one portion of the flap is a different opacity, color or texture than another portion of the flap. Both flaps may be a mesh fabric or other light transmissive material. When the flaps are positioned as in FIG. 6 it may or may not be possible to see through the flaps depending upon the weave of the flaps. The flaps may also be different colors as well as being light transmissive. The use of different colors, such as blue for one flap and yellow for the second flap, may cause the flaps to appear to be a third color, such as green, when the flaps are aligned as in FIG. 6 . A similar effect may be achieved by placing a third flap (not shown) between the two flaps.
[0034] A third present preferred embodiment 31 , shown in FIGS. 9, 10 and 11 has a narrow headrail 32 with a valance 33 . Like the first embodiment this embodiment has a plurality of shade elements 34 , first cords 35 , second cords 36 and lift cords 37 . Here cords 35 and 36 are fabric tape. Rods 21 and 22 are attached to the longitudinal edges of each shade element 34 . As in the second embodiment, flaps 38 and 39 extend from the longitudinal edges of the shade elements 34 . Each flap 38 , 39 has a stiffening rod 23 on its free edge. Because of the narrow headrail and because the shade elements are fabric, the longitudinal edges of each shade element will be closer together when in a horizontal, plane as shown in FIGS. 9 and 11 . Consequently, this embodiment has a relatively narrow profile. The headrail 32 may simply be a fabric-covered board having cord locks and pulleys attached to the bottom of the board behind the valances. This embodiment can be operated in the same manner as the previous embodiments depending upon whether the first cords or the second cords or neither the first cords nor second cords are fixed to the headrails. Pulling cords 36 will raise the second longitudinal edge of the shade elements to the position shown in FIG. 10 . Pulling the first cords will raise the first longitudinal edge of the shade elements. When the first longitudinal edge is raised, flaps 39 will cover the gap between adjacent shade elements 34 . If the second longitudinal edge is fully raised or the first longitudinal edge is lowered, then flaps 38 will be between adjacent shade elements. Preferably, flaps 38 do not allow light to pass and flaps 39 are a light transmissive material.
[0035] Any of the embodiments here disclosed could be corded to operate as a top down, bottom up blind. In such an embodiment the first cords and second cords would be movable such that all of the shade elements could be lowered onto a bottom rail or window sill. The cords would be connected to the shade elements in the same manner as in the embodiments shown in the drawings.
[0036] One could also provide top down bottom up capability through the use of another headrail or an intermediate rail as in the fourth embodiment 40 shown in FIGS. 12 and 13 . In this embodiment, the shade elements 42 may be similar to any of the shade elements of the first three embodiments. First cords 43 are attached to the one longitudinal edge of each shade element and have their upper ends affixed to the intermediate rail 41 . Second cords 44 are attached to the opposite longitudinal edge of each shade element and pass through the intermediate rail 41 and through a cord lock 48 at one end of the intermediate rail 41 . Lift cords 50 extend from the lowermost shade element or bottom rail into the intermediate rail through cord lock 49 . A second set of lift cords 46 is attached to the intermediate rail and passes through a cord lock 47 in the headrail 6 . If desired, cord locks 48 and 49 could be positioned in the headrail 6 in which case cords 44 and 45 would pass through the intermediate rail and into the headrail. In either configuration the cords would operate the shade elements in the same way. Cords 46 are attached to the intermediate rail and pass through a cord lock 47 in the headrail. These cords permit the intermediate rail 41 to be raised and lowered.
[0037] In all the embodiments described and illustrated to this point, the lower edge of every flap has been a straight line. However, such a configuration is not required. The bottom edge of one or more flaps could be curved, scalloped, or have another non-linear configuration. Moreover, a fringe could be attached to the bottom edge of one or more flaps. Another present preferred embodiment 51 shown in FIG. 14 has several shade elements 54 each having at least one flap 53 . In this embodiment the lower edges 55 of each flap 53 are scalloped. As in the previous embodiments rods 21 are attached to each shade element adjacent to the upper edge and lower edge of each shade element. Since the lower edge 55 is scalloped rod 23 is positioned above the scallops. A valance 52 extends from the front of the headrail 6 . First cords or tapes 56 are attached to the front edge of each shade element and have an upper end fixed to the headrail. Second cords 57 are attached to the opposite edge of each shade element and pass through cord lock 8 . Lift cords 58 are attached to the lowermost shade element or bottom rail and pass through cord lock 9 .
[0038] Each of the embodiments here disclosed has a pair of lift cords, a pair of first cords attached to one longitudinal edge of each shade element and a pair of second cords attached to the opposite longitudinal edge of each shade element. However, a single cord or more than two cords could be used in place of each pair of cords depending upon the size of the shade and the material used for the shade elements. One could use a tape or strip of fabric rather than a conventional cord material for the cords attached to the edges of the shade elements. Indeed, anything that functions in the same way as the cords shown in the preferred embodiment should be considered a cord for the purposes of this invention. The rods attached to the edges of the shade elements and flaps are preferably metal, but they could be plastic or fiberglass.
[0039] The headrail and bottom rail could be any configuration that is known in the art. Additionally, either or both of the headrail and the bottom rail could be covered with a fabric. This fabric may or may not be the same as the fabric used for the shade elements or a valance.
[0040] A seventh present preferred embodiment of my window covering 60 , shown in FIG. 15 , is similar to the embodiment of FIG. 1 . Accordingly, similar components bear the same reference number. In this embodiment I provide a panel of mesh fabric 61 that extends from the bottom rail 10 to the headrail 6 . This panel may or may not be attached to the longitudinal edges 12 of each shade elements 2 . If the panel is attached to those edges, then the upper edge of the fabric could be attached to a shaft or roller within the headrail making cords 4 unnecessary. The longitudinal edges of the shade elements could be raised or lowered by simply rolling and unrolling the panel about the shaft or roller. If desired one could provide a second panel (not shown) on the opposite side of the window covering and adjacent to edges 11 of the shade elements 2 . This panel may be used in place of or in addition to cords 3 . One could also use one or two panels of mesh fabric in combination with the embodiments shown in FIGS. 6 through 14 . The panel or panels would be connected between the headrail and the bottom rail in any of the same manners described here.
[0041] Although I have shown and described certain present preferred embodiments of my window covering having operable shade elements, it should be distinctly understood that the invention is not limited thereto, but may be variously embodied within the scope of the following claims.
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A window covering has a series of spaced apart, slat-like shade elements. Each shade element has a flap extending from one or both longitudinal edges of the shade elements. The space between adjacent shade elements is greater than the width of the shade elements and less than or equal to the width of the shade element plus the width of the flap. Cords are attached to the longitudinal edges of the shade elements so that the shade elements can be tilted or folded relative to the flaps. A panel of sheer material can be used in addition to or in place of the cords.
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RELATED APPLICATION DATA
[0001] This application is a division of application Ser. No. 10/358,447, filed Feb. 4, 2003 (now U.S. Pat. No. 6,744,907), which is a continuation of application Ser. No. 09/618,779, filed Jul. 17, 2000 (now U.S. Pat. No. 6,535,618), which is a continuation-in-part of application Ser. No. 09/150,147, filed Sep. 9, 1998 (now abandoned), which is a division of application Ser. No. 08/438,159, filed May 8, 1995 (now U.S. Pat. No. 5,850,481), which is a continuation-in-part of application Ser. No. 08/327,426, filed Oct. 21, 1994 (now U.S. Pat. No. 5,768,426). The software appendices published with U.S. Pat. No. 5,768,426 are incorporated herein by reference.
[0002] This application has essentially the same specification as application Ser. No. 08/327,426.
FIELD OF THE INVENTION
[0003] The present invention relates to methods and systems employing steganographic processing.
BACKGROUND AND SUMMARY OF THE INVENTION
[0004] “I would never put it in the power of any printer or publisher to suppress or alter a work of mine, by making him master of the copy”
[0005] Thomas Paine, Rights of Man, 1792.
[0006] “The printer dares not go beyond his licensed copy”
[0007] Milton, Aeropagetica, 1644.
[0008] Since time immemorial, unauthorized use and outright piracy of proprietary source material has been a source of lost revenue, confusion, and artistic corruption.
[0009] These historical problems have been compounded by the advent of digital technology. With it, the technology of copying materials and redistributing them in unauthorized manners has reached new heights of sophistication, and more importantly, omnipresence. Lacking objective means for comparing an alleged copy of material with the original, owners and possible litigation proceedings are left with a subjective opinion of whether the alleged copy is stolen, or has been used in an unauthorized manner. Furthermore, there is no simple means of tracing a path to an original purchaser of the material, something which can be valuable in tracing where a possible “leak” of the material first occurred.
[0010] A variety of methods for protecting commercial material have been attempted. One is to scramble signals via an encoding method prior to distribution, and descramble prior to use. This technique, however, requires that both the original and later descrambled signals never leave closed and controlled networks, lest they be intercepted and recorded. Furthermore, this arrangement is of little use in the broad field of mass marketing audio and visual material, where even a few dollars extra cost causes a major reduction in market, and where the signal must eventually be descrambled to be perceived, and thus can be easily recorded.
[0011] Another class of techniques relies on modification of source audio or video signals to include a subliminal identification signal, which can be sensed by electronic means. Examples of such systems are found in U.S. Pat. No. 4,972,471 and European patent publication EP 441,702, as well as in Komatsu et al, “Authentication System Using Concealed Image in Telematics,” Memoirs of the School of Science & Engineering, Waseda University, No. 52, p. 45-60 (1988) (Komatsu uses the term “digital watermark” for this technique). An elementary introduction to these methods is found in the article “Digital Signatures,” Byte Magazine, November, 1993, p. 309. These techniques have the common characteristic that deterministic signals with well defined patterns and sequences within the source material convey the identification information. For certain applications this is not a drawback. But in general, this is an inefficient form of embedding identification information for a variety of reasons: (a) the whole of the source material is not used; (b) deterministic patterns have a higher likelihood of being discovered and removed by a would-be pirate; and (c) the signals are not generally ‘holographic’ in that identifications may be difficult to make given only sections of the whole. (‘Holographic’ is used herein to refer to the property that the identification information is distributed globally throughout the coded signal, and can be fully discerned from an examination of even a fraction of the coded signal. Coding of this type is sometimes termed “distributed” herein.)
[0012] Among the cited references are descriptions of several programs which perform steganography—described in one document as “ . . . the ancient art of hiding information in some otherwise inconspicuous information.” These programs variously allow computer users to hide their own messages inside digital image files and digital audio files. All do so by toggling the least significant bit (the lowest order bit of a single data sample) of a given audio data stream or rasterized image. Some of these programs embed messages quite directly into the least significant bit, while other “pre-encrypt” or scramble a message first and then embed the encrypted data into the least significant bit.
[0013] Our current understanding of these programs is that they generally rely on error-free transmission of the of digital data in order to correctly transmit a given message in its entirety. Typically the message is passed only once, i.e., it is not repeated. These programs also seem to “take over” the least significant bit entirely, where actual data is obliterated and the message placed accordingly. This might mean that such codes could be easily erased by merely stripping off the least significant bit of all data values in a given image or audio file. It is these and other considerations which suggest that the only similarity between our invention and the established art of steganography is in the placement of information into data files with minimal perceptibility. The specifics of embedding and the uses of that buried information diverge from there.
[0014] Another cited reference is U.S. Pat. No. 5,325,167 to Melen. In the service of authenticating a given document, the high precision scanning of that document reveals patterns and “microscopic grain structure” which apparently is a kind of unique fingerprint for the underlying document media, such as paper itself or post-applied materials such as toner. Melen further teaches that scanning and storing this fingerprint can later be used in authentication by scanning a purported document and comparing it to the original fingerprint. Applicant is aware of a similar idea employed in the very high precision recording of credit card magnetic strips, as reported in the Wall Street Journal but which cannot presently be located, wherein very fine magnetic fluxuations tend to be unique from one card to the next, so that credit card authentication could be achieved through pre-recording these fluxuations later to be compared to the recordings of the purportedly same credit card.
[0015] Both of the foregoing techniques appear to rest on the same identification principles on which the mature science of fingerprint analysis rests: the innate uniqueness of some localized physical property. These methods then rely upon a single judgment and/or measurement of “similarity” or “correlation” between a suspect and a pre-recording master. Though fingerprint analysis has brought this to a high art, these methods are nevertheless open to a claim that preparations of the samples, and the “filtering” and “scanner specifications” of Melen's patent, unavoidably tend to bias the resulting judgment of similarity, and would create a need for more esoteric “expert testimony” to explain the confidence of a found match or mis-match. An object of the present invention is to avoid this reliance on expert testimony and to place the confidence in a match into simple “coin flip” vernacular, i.e., what are the odds you can call the correct coin flip 16 times in a row. Attempts to identify fragments of a fingerprint, document, or otherwise, exacerbate this issue of confidence in a judgment, where it is an object of the present invention to objectively apply the intuitive “coin flip” confidence to the smallest fragment possible. Also, storing unique fingerprints for each and every document or credit card magnetic strip, and having these fingerprints readily available for later cross-checking, should prove to be quite an economic undertaking. It is an object of this invention to allow for the “re-use” of noise codes and “snowy images” in the service of easing storage requirements.
[0016] U.S. Pat. No. 4,921,278 to Shiang et al. teaches a kind of spatial encryption technique wherein a signature or photograph is splayed out into what the untrained eye would refer to as noise, but which is actually a well defined structure referred to as Moiré patterns. The similarities of the present invention to Shiang's system appear to be use of noise-like patterns which nevertheless carry information, and the use of this principle on credit cards and other identification cards.
[0017] Others of the cited patents deal with other techniques for identification and/or authentication of signals or media. U.S. Pat. No. 4,944,036 to Hyatt does not appear to be applicable to the present invention, but does point out that the term “signature” can be equally applied to signals which carry unique characteristics based on physical structure.
[0018] Despite the foregoing and other diverse work in the field of identification/authentication, there still remains a need for a reliable and efficient method for performing a positive identification between a copy of an original signal and the original. Desirably, this method should not only perform identification, it should also be able to convey source-version information in order to better pinpoint the point of sale. The method should not compromise the innate quality of material which is being sold, as does the placement of localized logos on images. The method should be robust so that an identification can be made even after multiple copies have been made and/or compression and decompression of the signal has taken place. The identification method should be largely uneraseable or “uncrackable.” The method should be capable of working even on fractional pieces of the original signal, such as a 10 second “riff” of an audio signal or the “clipped and pasted” sub-section of an original image.
[0019] The existence of such a method would have profound consequences on piracy in that it could (a) cost effectively monitor for unauthorized uses of material and perform “quick checks”; (b) become a deterrent to unauthorized uses when the method is known to be in use and the consequences well publicized; and (c) provide unequivocal proof of identity, similar to fingerprint identification, in litigation, with potentially more reliability than that of fingerprinting.
[0020] In accordance with an exemplary embodiment of the invention, the foregoing and additional objects are achieved by embedding an imperceptible identification code throughout a source signal. In the preferred embodiment, this embedding is achieved by modulating the source signal with a small noise signal in a coded fashion. More particularly, bits of a binary identification code are referenced, one at a time, to control modulation of the source signal with the noise signal.
[0021] The copy with the embedded signal (the “encoded” copy) becomes the material which is sold, while the original is secured in a safe place. The new copy is nearly identical to the original except under the finest of scrutiny; thus, its commercial value is not compromised. After the new copy has been sold and distributed and potentially distorted by multiple copies, the present disclosure details methods for positively identifying any suspect signal against the original.
[0022] Among its other advantages, the preferred embodiments' use of identification signals which are global (holographic) and which mimic natural noise sources allows the maximization of identification signal energy, as opposed to merely having it present ‘somewhere in the original material.’ This allows the identification coding to be much more robust in the face of thousands of real world degradation processes and material transformations, such as cutting and cropping of imagery.
[0023] The foregoing and additional features and advantages of the present invention will be more readily apparent from the following detailed description thereof, which proceeds with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] [0024]FIG. 1 is a simple and classic depiction of a one dimensional digital signal which is discretized in both axes.
[0025] [0025]FIG. 2 is a general overview, with detailed description of steps, of the process of embedding an “imperceptible” identification signal onto another signal.
[0026] [0026]FIG. 3 is a step-wise description of how a suspected copy of an original is identified.
[0027] [0027]FIG. 4 is a schematic view of an apparatus for pre-exposing film with identification information in accordance with another embodiment of the present invention.
[0028] [0028]FIG. 5 is a diagram of a “black box” embodiment of the present invention.
[0029] [0029]FIG. 6 is a schematic block diagram of the embodiment of FIG. 5.
[0030] [0030]FIG. 7 shows a variant of the FIG. 6 embodiment adapted to encode successive sets of input data with different code words but with the same noise data.
[0031] [0031]FIG. 8 shows a variant of the FIG. 6 embodiment adapted to encode each frame of a videotaped production with a unique code number.
[0032] [0032]FIGS. 9A-9C are representations of an industry standard noise second that can be used in one embodiment of the present invention.
[0033] [0033]FIG. 10 shows an integrated circuit used in detecting standard noise codes.
[0034] [0034]FIG. 11 shows a process flow for detecting a standard noise code that can be used in the FIG. 10 embodiment.
[0035] [0035]FIG. 12 is an embodiment employing a plurality of detectors in accordance with another embodiment of the present invention.
DETAILED DESCRIPTION
[0036] In the following discussion of an illustrative embodiment, the words “signal” and “image” are used interchangeably to refer to both one, two, and even beyond two dimensions of digital signal. Examples will routinely switch back and forth between a one dimensional audio-type digital signal and a two dimensional image-type digital signal.
[0037] In order to fully describe the details of an illustrative embodiment of the invention, it is necessary first to describe the basic properties of a digital signal. FIG. 1 shows a classic representation of a one dimensional digital signal. The x-axis defines the index numbers of sequence of digital “samples,” and the y-axis is the instantaneous value of the signal at that sample, being constrained to exist only at a finite number of levels defined as the “binary depth” of a digital sample. The example depicted in FIG. 1 has the value of 2 to the fourth power, or “4 bits,” giving 16 allowed states of the sample value.
[0038] For audio information such as sound waves, it is commonly accepted that the digitization process discretizes a continuous phenomena both in the time domain and in the signal level domain. As such, the process of digitization itself introduces a fundamental error source, in that it cannot record detail smaller than the discretization interval in either domain. The industry has referred to this, among other ways, as “aliasing” in the time domain, and “quantization noise” in the signal level domain. Thus, there will always be a basic error floor of a digital signal. Pure quantization noise, measured in a root mean square sense, is theoretically known to have the value of one over the square root of twelve, or about 0.29 DN, where DN stands for ‘Digital Number’ or the finest unit increment of the signal level. For example, a perfect 12-bit digitizer will have 4096 allowed DN with an innate root mean square noise floor of 0.29 DN.
[0039] All known physical measurement processes add additional noise to the transformation of a continuous signal into the digital form. The quantization noise typically adds in quadrature (square root of the mean squares) to the “analog noise” of the measurement process, as it is sometimes referred to.
[0040] With almost all commercial and technical processes, the use of the decibel scale is used as a measure of signal and noise in a given recording medium. The expression “signal-to-noise ratio” is generally used, as it will be in this disclosure. As an example, this disclosure refers to signal to noise ratios in terms of signal power and noise power, thus 20 dB represents a 10 times increase in signal amplitude.
[0041] In summary, the presently preferred embodiments of the invention embed an N-bit value onto an entire signal through the addition of a very low amplitude encodation signal which has the look of pure noise. N is usually at least 8 and is capped on the higher end by ultimate signal-to-noise considerations and “bit error” in retrieving and decoding the N-bit value. As a practical matter, N is chosen based on application specific considerations, such as the number of unique different “signatures” that are desired. To illustrate, if N=128, then the number of unique digital signatures is in excess of 10 {circumflex over ( )}{circumflex over ( )}38 (2 {circumflex over ( )}{circumflex over ( )}128). This number is believed to be more than adequate to both identify the material with sufficient statistical certainty and to index exact sale and distribution information.
[0042] The amplitude or power of this added signal is determined by the aesthetic and informational considerations of each and every application using the present methodology. For instance, non-professional video can stand to have a higher embedded signal level without becoming noticeable to the average human eye, while high precision audio may only be able to accept a relatively small signal level lest the human ear perceive an objectionable increase in “hiss.” These statements are generalities and each application has its own set of criteria in choosing the signal level of the embedded identification signal. The higher the level of embedded signal, the more corrupted a copy can be and still be identified. On the other hand, the higher the level of embedded signal, the more objectionable the perceived noise might be, potentially impacting the value of the distributed material.
[0043] To illustrate the range of different applications to which the principles of the present invention can be applied, the present specification details two different systems. The first (termed, for lack of a better name, a “batch encoding” system), applies identification coding to an existing data signal. The second (termed, for lack of a better name, a “real time encoding” system), applies identification coding to a signal as it is produced. Those skilled in the art will recognize that the principles of the present invention can be applied in a number of other contexts in addition to these particularly described.
[0044] The discussions of these two systems can be read in either order. Some readers may find the latter more intuitive than the former; for others the contrary may be true.
[0045] Batch Encoding
[0046] The following discussion of a first class of embodiments is best prefaced by a section defining relevant terms:
[0047] The original signal refers to either the original digital signal or the high quality digitized copy of a non-digital original.
[0048] The N-bit identification word refers to a unique identification binary value, typically having N range anywhere from 8 to 128, which is the identification code ultimately placed onto the original signal via the disclosed transformation process. In the illustrated embodiment, each N-bit identification word begins with the sequence of values ‘0101,’ which is used to determine an optimization of the signal-to-noise ratio in the identification procedure of a suspect signal (see definition below).
[0049] The m'th bit value of the N-bit identification word is either a zero or one corresponding to the value of the m'th place, reading left to right, of the N-bit word. E.g., the first (m=1) bit value of the N=8 identification word 01110100 is the value ‘0;’ the second bit value of this identification word is ‘1’, etc.
[0050] The m'th individual embedded code signal refers to a signal which has dimensions and extent precisely equal to the original signal (e.g. both are a 512 by 512 digital image), and which is (in the illustrated embodiment) an independent pseudo-random sequence of digital values. “Pseudo” pays homage to the difficulty in philosophically defining pure randomness, and also indicates that there are various acceptable ways of generating the “random” signal. There will be exactly N individual embedded code signals associated with any given original signal.
[0051] The acceptable perceived noise level refers to an application-specific determination of how much “extra noise,” i.e. amplitude of the composite embedded code signal described next, can be added to the original signal and still have an acceptable signal to sell or otherwise distribute. This disclosure uses a 1 dB increase in noise as a typical value which might be acceptable, but this is quite arbitrary.
[0052] The composite embedded code signal refers to the signal which has dimensions and extent precisely equal to the original signal, (e.g. both are a 512 by 512 digital image), and which contains the addition and appropriate attenuation of the N individual embedded code signals. The individual embedded signals are generated on an arbitrary scale, whereas the amplitude of the composite signal must not exceed the pre-set acceptable perceived noise level, hence the need for “attenuation” of the N added individual code signals.
[0053] The distributable signal refers to the nearly similar copy of the original signal, consisting of the original signal plus the composite embedded code signal. This is the signal which is distributed to the outside community, having only slightly higher but acceptable “noise properties” than the original.
[0054] A suspect signal refers to a signal which has the general appearance of the original and distributed signal and whose potential identification match to the original is being questioned. The suspect signal is then analyzed to see if it matches the N-bit identification word.
[0055] The detailed methodology of this first embodiment begins by stating that the N-bit identification word is encoded onto the original signal by having each of the m bit values multiply their corresponding individual embedded code signals, the resultant being accumulated in the composite signal, the fully summed composite signal then being attenuated down to the acceptable perceived noise amplitude, and the resultant composite signal added to the original to become the distributable signal.
[0056] The original signal, the N-bit identification word, and all N individual embedded code signals are then stored away in a secured place. A suspect signal is then found. This signal may have undergone multiple copies, compressions and decompressions, resamplings onto different spaced digital signals, transfers from digital to analog back to digital media, or any combination of these items. IF the signal still appears similar to the original, i.e. its innate quality is not thoroughly destroyed by all of these transformations and noise additions, then depending on the signal to noise properties of the embedded signal, the identification process should function to some objective degree of statistical confidence. The extent of corruption of the suspect signal and the original acceptable perceived noise level are two key parameters in determining an expected confidence level of identification.
[0057] The identification process on the suspected signal begins by resampling and aligning the suspected signal onto the digital format and extent of the original signal. Thus, if an image has been reduced by a factor of two, it needs to be digitally enlarged by that same factor. Likewise, if a piece of music has been “cut out,” but may still have the same sampling rate as the original, it is necessary to register this cut-out piece to the original, typically done by performing a local digital cross-correlation of the two signals (a common digital operation), finding at what delay value the correlation peaks, then using this found delay value to register the cut piece to a segment of the original.
[0058] Once the suspect signal has been sample-spacing matched and registered to the original, the signal levels of the suspect signal should be matched in an rms sense to the signal level of the original. This can be done via a search on the parameters of offset, amplification, and gamma being optimized by using the minimum of the mean squared error between the two signals as a function of the three parameters. We can call the suspect signal normalized and registered at this point, or just normialized for convenience.
[0059] The newly matched pair then has the original signal subtracted from the normalized suspect signal to produce a difference signal. The difference signal is then cross-correlated with each of the N individual embedded code signals and the peak cross-correlation value recorded. The first four bit code (‘0101’) is used as a calibrator both on the mean values of the zero value and the one value, and on further registration of the two signals if a finer signal to noise ratio is desired (i.e., the optimal separation of the 0101 signal will indicate an optimal registration of the two signals and will also indicate the probable existence of the N-bit identification signal being present.)
[0060] The resulting peak cross-correlation values will form a noisy series of floating point numbers which can be transformed into O's and 1 's by their proximity to the mean values of 0 and 1 found by the 0101 calibration sequence. If the suspect signal has indeed been derived from the original, the identification number resulting from the above process will match the N-bit identification word of the original, bearing in mind either predicted or unknown “bit error” statistics. Signal-to-noise considerations will determine if there will be some kind of “bit error” in the identification process, leading to a form of X % probability of identification where X might be desired to be 99.9% or whatever. If the suspect copy is indeed not a copy of the original, an essentially random sequence of O's and 1 's will be produced, as well as an apparent lack of separation of the resultant values. This is to say, if the resultant values are plotted on a histogram, the existence of the N-bit identification signal will exhibit strong bi-level characteristics, whereas the non-existence of the code, or the existence of a different code of a different original, will exhibit a type of random gaussian-like distribution. This histogram separation alone should be sufficient for an identification, but it is even stronger proof of identification when an exact binary sequence can be objectively reproduced.
[0061] Specific Example
[0062] Imagine that we have taken a valuable picture of two heads of state at a cocktail party, pictures which are sure to earn some reasonable fee in the commercial market. We desire to sell this picture and ensure that it is not used in an unauthorized or uncompensated manner. This and the following steps are summarized in FIG. 2.
[0063] Assume the picture is transformed into a positive color print. We first scan this into a digitized form via a normal high quality black and white scanner with a typical photometric spectral response curve. (It is possible to get better ultimate signal to noise ratios by scanning in each of the three primary colors of the color image, but this nuance is not central to describing the basic process.)
[0064] Let us assume that the scanned image now becomes a 4000 by 4000 pixel monochrome digital image with a grey scale accuracy defined by 12-bit grey values or 4096 allowed levels. We will call this the “original digital image” realizing that this is the same as our “original signal” in the above definitions.
[0065] During the scanning process we have arbitrarily set absolute black to correspond to digital value ‘30’. We estimate that there is a basic 2 Digital Number root mean square noise existing on the original digital image, plus a theoretical noise (known in the industry as “shot noise”) of the square root of the brightness value of any given pixel. In formula, we have:
< RMS Noise n,m >=sqrt (4+(V n,m −30)) (1)
[0066] Here, n and m are simple indexing values on rows and columns of the image ranging from 0 to 3999. Sqrt is the square root. V is the DN of a given indexed pixel on the original digital image. The < > brackets around the RMS noise merely indicates that this is an expected average value, where it is clear that each and every pixel will have a random error individually. Thus, for a pixel value having 1200 as a digital number or “brightness value”, we find that its expected rms noise value is sqrt(1204)=34.70, which is quite close to 34.64, the square root of 1200.
[0067] We furthermore realize that the square root of the innate brightness value of a pixel is not precisely what the eye perceives as a minimum objectionable noise, thus we come up with the formula:
< RMS Addable Noise n,m >=X*sqrt (4+( V n,m −30){circumflex over ( )}Y) (2)
[0068] Where X and Y have been added as empirical parameters which we will adjust, and “addable” noise refers to our acceptable perceived noise level from the definitions above. We now intend to experiment with what exact value of X and Y we can choose, but we will do so at the same time that we are performing the next steps in the process.
[0069] The next step in our process is to choose N of our N-bit identification word. We decide that a 16 bit main identification value with its 65536 possible values will be sufficiently large to identify the image as ours, and that we will be directly selling no more than 128 copies of the image which we wish to track, giving 7 bits plus an eighth bit for an odd/even adding of the first 7 bits (i.e. an error checking bit on the first seven). The total bits required now are at 4 bits for the 0101 calibration sequence, 16 for the main identification, 8 for the version, and we now throw in another 4 as a further error checking value on the first 28 bits, giving 32 bits as N. The final 4 bits can use one of many industry standard error checking methods to choose its four values.
[0070] We now randomly determine the 16 bit main identification number, finding for example, 1101 0001 1001 1110; our first versions of the original sold will have all 0's as the version identifier, and the error checking bits will fall out where they may. We now have our unique 32 bit identification word which we will embed on the original digital image.
[0071] To do this, we generate 32 independent random 4000 by 4000 encoding images for each bit of our 32 bit identification word. The manner of generating these random images is revealing. There are numerous ways to generate these. By far the simplest is to turn up the gain on the same scanner that was used to scan in the original photograph, only this time placing a pure black image as the input, then scanning this 32 times. The only drawback to this technique is that it does require a large amount of memory and that “fixed pattern” noise will be part of each independent “noise image.” But, the fixed pattern noise can be removed via normal “dark frame” subtraction techniques. Assume that we set the absolute black average value at digital number ‘100,’ and that rather than finding a 2 DN rms noise as we did in the normal gain setting, we now find an rms noise of 10 DN about each and every pixel's mean value.
[0072] We next apply a mid-spatial-frequency bandpass filter (spatial convolution) to each and every independent random image, essentially removing the very high and the very low spatial frequencies from them. We remove the very low frequencies because simple real-world error sources like geometrical warping, splotches on scanners, mis-registrations, and the like will exhibit themselves most at lower frequencies also, and so we want to concentrate our identification signal at higher spatial frequencies in order to avoid these types of corruptions. Likewise, we remove the higher frequencies because multiple generation copies of a given image, as well as compression-decompression transformations, tend to wipe out higher frequencies anyway, so there is no point in placing too much identification signal into these frequencies if they will be the ones most prone to being attenuated. Therefore, our new filtered independent noise images will be dominated by mid-spatial frequencies. On a practical note, since we are using 12-bit values on our scanner and we have removed the DC value effectively and our new rms noise will be slightly less than 10 digital numbers, it is useful to boil this down to a 6-bit value ranging from −32 through 0 to 31 as the resultant random image.
[0073] Next we add all of the random images together which have a ‘1’ in their corresponding bit value of the 32-bit identification word, accumulating the result in a 16-bit signed integer image. This is the unattenuated and un-scaled version of the composite embedded signal.
[0074] Next we experiment visually with adding the composite embedded signal to the original digital image, through varying the X and Y parameters of equation 2. In formula, we visually iterate to both maximize X and to find the appropriate Y in the following:
V dist;n,m =V orig;n,m +V comp;n,m *X*Sqrt (4 +V orig;n,m {circumflex over ( )}Y) (3)
[0075] where dist refers to the candidate distributable image, i.e. we are visually iterating to find what X and Y will give us an acceptable image; orig refers to the pixel value of the original image; and comp refers to the pixel value of the composite image. The n's and m's still index rows and columns of the image and indicate that this operation is done on all 4000 by 4000 pixels. The symbol V is the DN of a given pixel and a given image.
[0076] As an arbitrary assumption, now, we assume that our visual experimentation has found that the value of X=0.025 and Y=0.6 are acceptable values when comparing the original image with the candidate distributable image. This is to say, the distributable image with the “extra noise” is acceptably close to the original in an aesthetic sense. Note that since our individual random images had a random rms noise value around 10 DN, and that adding approximately 16 of these images together will increase the composite noise to around 40 DN, the X multiplication value of 0.025 will bring the added rms noise back to around 1 DN, or half the amplitude of our innate noise on the original. This is roughly a 1 dB gain in noise at the dark pixel values and correspondingly more at the brighter values modified by the Y value of 0.6.
[0077] So with these two values of X and Y, we now have constructed our first versions of a distributable copy of the original. Other versions will merely create a new composite signal and possibly change the X slightly if deemed necessary. We now lock up the original digital image along with the 32-bit identification word for each version, and the 32 independent random 4-bit images, waiting for our first case of a suspected piracy of our original. Storage wise, this is about 14 Megabytes for the original image and 32*0.5 bytes*16 million=˜256 Megabytes for the random individual encoded images. This is quite acceptable for a single valuable image. Some storage economy can be gained by simple lossless compression.
[0078] Finding a Suspected Piracy of our Image
[0079] We sell our image and several months later find our two heads of state in the exact poses we sold them in, seemingly cut and lifted out of our image and placed into another stylized background scene. This new “suspect” image is being printed in 100,000 copies of a given magazine issue, let us say. We now go about determining if a portion of our original image has indeed been used in an unauthorized manner. FIG. 3 summarizes the details.
[0080] The first step is to take an issue of the magazine, cut out the page with the image on it, then carefully but not too carefully cut out the two figures from the background image using ordinary scissors. If possible, we will cut out only one connected piece rather than the two figures separately. We paste this onto a black background and scan this into a digital form. Next we electronically flag or mask out the black background, which is easy to do by visual inspection.
[0081] We now procure the original digital image from our secured place along with the 32-bit identification word and the 32 individual embedded images. We place the original digital image onto our computer screen using standard image manipulation software, and we roughly cut along the same borders as our masked area of the suspect image, masking this image at the same time in roughly the same manner. The word ‘roughly’ is used since an exact cutting is not needed, it merely aids the identification statistics to get it reasonably close.
[0082] Next we rescale the masked suspect image to roughly match the size of our masked original digital image, that is, we digitally scale up or down the suspect image and roughly overlay it on the original image. Once we have performed this rough registration, we then throw the two images into an automated scaling and registration program. The program performs a search on the three parameters of x position, y position, and spatial scale, with the figure of merit being the mean squared error between the two images given any given scale variable and x and y offset. This is a fairly standard image processing methodology. Typically this would be done using generally smooth interpolation techniques and done to sub-pixel accuracy. The search method can be one of many, where the simplex method is a typical one.
[0083] Once the optimal scaling and x-y position variables are found, next comes another search on optimizing the black level, brightness gain, and gamma of the two images. Again, the figure of merit to be used is mean squared error, and again the simplex or other search methodologies can be used to optimize the three variables. After these three variables are optimized, we apply their corrections to the suspect image and align it to exactly the pixel spacing and masking of the original digital image and its mask. We can now call this the standard mask.
[0084] The next step is to subtract the original digital image from the newly normalized suspect image only within the standard mask region. This new image is called the difference image.
[0085] Then we step through all 32 individual random embedded images, doing a local cross-correlation between the masked difference image and the masked individual embedded image. ‘Local’ refers to the idea that one need only start correlating over an offset region of +/−1 pixels of offset between the nominal registration points of the two images found during the search procedures above. The peak correlation should be very close to the nominal registration point of 0,0 offset, and we can add the 3 by 3 correlation values together to give one grand correlation value for each of the 32 individual bits of our 32-bit identification word.
[0086] After doing this for all 32 bit places and their corresponding random images, we have a quasi-floating point sequence of 32 values. The first four values represent our calibration signal of 0101. We now take the mean of the first and third floating point value and call this floating point value ‘0,’ and we take the mean of the second and the fourth value and call this floating point value ‘1.’ We then step through all remaining 28 bit values and assign either a ‘0’or a ‘1’ based simply on which mean value they are closer to. Stated simply, if the suspect image is indeed a copy of our original, the embedded 32-bit resulting code should match that of our records, and if it is not a copy, we should get general randomness. The third and the fourth possibilities of 3) Is a copy but doesn't match identification number and 4) isn't a copy but does match are, in the case of 3), possible if the signal to noise ratio of the process has plummeted, i.e. the ‘suspect image’ is truly a very poor copy of the original, and in the case of 4) is basically one chance in four billion since we were using a 32-bit identification number. If we are truly worried about 4), we can just have a second independent lab perform their own tests on a different issue of the same magazine. Finally, checking the error-check bits against what the values give is one final and possibly overkill check on the whole process. In situations where signal to noise is a possible problem, these error checking bits might be eliminated without too much harm.
[0087] Benefits
[0088] Now that a full description of the first embodiment has been described via a detailed example, it is appropriate to point out the rationale of some of the process steps and their benefits.
[0089] The ultimate benefits of the foregoing process are that obtaining an identification number is fully independent of the manners and methods of preparing the difference image. That is to say, the manners of preparing the difference image, such as cutting, registering, scaling, etcetera, cannot increase the odds of finding an identification number when none exists; it only helps the signal-to-noise ratio of the identification process when a true identification number is present. Methods of preparing images for identification can be different from each other even, providing the possibility for multiple independent methodologies for making a match.
[0090] The ability to obtain a match even on sub-sets of the original signal or image is a key point in today's information-rich world. Cutting and pasting both images and sound clips is becoming more common, allowing such an embodiment to be used in detecting a copy even when original material has been thus corrupted. Finally, the signal to noise ratio of matching should begin to become difficult only when the copy material itself has been significantly altered either by noise or by significant distortion; both of these also will affect that copy's commercial value, so that trying to thwart the system can only be done at the expense of a huge decrease in commercial value.
[0091] The fullest expression of the present system will come when it becomes an industry standard and numerous independent groups set up with their own means or ‘in-house’ brand of applying embedded identification numbers and in their decipherment. Numerous independent group identification will further enhance the ultimate objectivity of the method, thereby enhancing its appeal as an industry standard.
[0092] Use of True Polarity in Creating the Composite Embedded Code Signal
[0093] The foregoing discussion made use of the 0 and 1 formalism of binary technology to accomplish its ends. Specifically, the O's and l's of the N-bit identification word directly multiplied their corresponding individual embedded code signal to form the composite embedded code signal (step 8 , FIG. 2). This approach certainly has its conceptual simplicity, but the multiplication of an embedded code signal by 0 along with the storage of that embedded code contains a kind of inefficiency.
[0094] It is preferred to maintain the formalism of the 0 and 1 nature of the N-bit identification word, but to have the O's of the word induce a subtraction of their corresponding embedded code signal. Thus, in step 8 of FIG. 2, rather than only ‘adding’ the individual embedded code signals which correspond to a ‘1’ in the N-bit identification word, we will also ‘subtract’ the individual embedded code signals which correspond to a ‘O’ in the N-bit identification word.
[0095] At first glance this seems to add more apparent noise to the final composite signal. But it also increases the energy-wise separation of the O's from the 1's, and thus the ‘gain’ which is applied in step 10 , FIG. 2 can be correspondingly lower.
[0096] We can refer to this improvement as the use of true polarity. The main advantage of this improvement can largely be summarized as ‘informational efficiency.’
[0097] ‘Perceptual Orthogonality’ of the Individual Embedded Code Signals
[0098] The foregoing discussion contemplates the use of generally random noise-like signals as the individual embedded code signals. This is perhaps the simplest form of signal to generate. However, there is a form of informational optimization which can be applied to the set of the individual embedded signals, which the applicant describes under the rubric ‘perceptual orthogonality.’ This term is loosely based on the mathematical concept of the orthogonality of vectors, with the current additional requirement that this orthogonality should maximize the signal energy of the identification information while maintaining it below some perceptibility threshold. Put another way, the embedded code signals need not necessarily be random in nature.
[0099] Use and Improvements of the First Embodiment in the Field of Emulsion-Based Photogaphy
[0100] The foregoing discussion outlined techniques that are applicable to photographic materials. The following section explores the details of this area further and discloses certain improvements which lend themselves to a broad range of applications.
[0101] The first area to be discussed involves the pre-application or pre-exposing of a serial number onto traditional photographic products, such as negative film, print paper, transparencies, etc. In general, this is a way to embed a priori unique serial numbers (and by implication, ownership and tracking information) into photographic material. The serial numbers themselves would be a permanent part of the normally exposed picture, as opposed to being relegated to the margins or stamped on the back of a printed photograph, which all require separate locations and separate methods of copying. The ‘serial number’ as it is called here is generally synonymous with the N-bit identification word, only now we are using a more common industrial terminology.
[0102] In FIG. 2, step 11 , the disclosure calls for the storage of the “original [image]” along with code images. Then in FIG. 3, step 9 , it directs that the original be subtracted from the suspect image, thereby leaving the possible identification codes plus whatever noise and corruption has accumulated. Therefore, the previous disclosure made the tacit assumption that there exists an original without the composite embedded signals.
[0103] Now in the case of selling print paper and other duplication film products, this will still be the case, i.e., an “original” without the embedded codes will indeed exist and the basic methodology of the first embodiment can be employed. The original film serves perfectly well as an ‘unencoded original.’
[0104] However, in the case where pre-exposed negative film is used, the composite embedded signal pre-exists on the original film and thus there will never be an “original” separate from the pre-embedded signal. It is this latter case, therefore, which will be examined a bit more closely, along with observations on how to best use the principles discussed above (the former cases adhering to the previously outlined methods).
[0105] The clearest point of departure for the case of pre-numbered negative film, i.e. negative film which has had each and every frame pre-exposed with a very faint and unique composite embedded signal, comes at step 9 of FIG. 3 as previously noted. There are certainly other differences as well, but they are mostly logistical in nature, such as how and when to embed the signals on the film, how to store the code numbers and serial number, etc. Obviously the pre-exposing of film would involve a major change to the general mass production process of creating and packaging film.
[0106] [0106]FIG. 4 has a schematic outlining one potential post-hoc mechanism for pre-exposing film. ‘Post-hoc’ refers to applying a process after the full common manufacturing process of film has already taken place. Eventually, economies of scale may dictate placing this pre-exposing process directly into the chain of manufacturing film. Depicted in FIG. 4 is what is commonly known as a film writing system. The computer, 106 , displays the composite signal produced in step 8 , FIG. 2, on its phosphor screen. A given frame of film is then exposed by imaging this phosphor screen, where the exposure level is generally very faint, i.e. generally imperceptible. Clearly, the marketplace will set its own demands on how faint this should be, that is, the level of added ‘graininess’ as practitioners would put it. Each frame of film is sequentially exposed, where in general the composite image displayed on the CRT 102 is changed for each and every frame, thereby giving each frame of film a different serial number. The transfer lens 104 highlights the focal conjugate planes of a film frame and the CRT face.
[0107] Getting back to the applying the principles of the foregoing embodiment in the case of pre-exposed negative film. At step 9 , FIG. 3, if we were to subtract the “original” with its embedded code, we would obviously be “erasing” the code as well since the code is an integral part of the original. Fortunately, remedies do exist and identifications can still be made. However, it will be a challenge to artisans who refine this embodiment to have the signal to noise ratio of the identification process in the pre-exposed negative case approach the signal to noise ratio of the case where the un-encoded original exists.
[0108] A succinct definition of the problem is in order at this point. Given a suspect picture (signal), find the embedded identification code IF a code exists at al. The problem reduces to one of finding the amplitude of each and every individual embedded code signal within the suspect picture, not only within the context of noise and corruption as was previously explained, but now also within the context of the coupling between a captured image and the codes. ‘Coupling’ here refers to the idea that the captured image “randomly biases” the cross-correlation.
[0109] So, bearing in mind this additional item of signal coupling, the identification process now estimates the signal amplitude of each and every individual embedded code signal (as opposed to taking the cross-correlation result of step 12 , FIG. 3). If our identification signal exists in the suspect picture, the amplitudes thus found will split into a polarity with positive amplitudes being assigned a ‘1’ and negative amplitudes being assigned a ‘0’. Our unique identification code manifests itself. If, on the other hand, no such identification code exists or it is someone else's code, then a random gaussian-like distribution of amplitudes is found with a random hash of values.
[0110] It remains to provide a few more details on how the amplitudes of the individual embedded codes are found. Again, fortunately, this exact problem has been treated in other technological applications. Besides, throw this problem and a little food into a crowded room of mathematicians and statisticians and surely a half dozen optimized methodologies will pop out after some reasonable period of time. It is a rather cleanly defined problem.
[0111] One specific example solution comes from the field of astronomical imaging. Here, it is a mature prior art to subtract out a “thermal noise frame” from a given CCD image of an object. Often, however, it is not precisely known what scaling factor to use in subtracting the thermal frame, and a search for the correct scaling factor is performed. This is precisely the task of this step of the present embodiment.
[0112] General practice merely performs a common search algorithm on the scaling factor, where a scaling factor is chosen and a new image is created according to:
NEW IMAGE=ACQUIRED IMAGE−SCALE*THERMAL IMAGE (4)
[0113] The new image is applied to the fast Fourier transform routine and a scale factor is eventually found which minimizes the integrated high frequency content of the new image. This general type of search operation with its minimization of a particular quantity is exceedingly common. The scale factor thus found is the sought-for “amplitude.” Refinements which are contemplated but not yet implemented are where the coupling of the higher derivatives of the acquired image and the embedded codes are estimated and removed from the calculated scale factor. In other words, certain bias effects from the coupling mentioned earlier are present and should be eventually accounted for and removed both through theoretical and empirical experimentation.
[0114] Use and Improvements in the Detection of Signal or Image Alteration
[0115] Apart from the basic need of identifying a signal or image as a whole, there is also a rather ubiquitous need to detect possible alterations to a signal or image. The following section describes how the foregoing embodiment, with certain modifications and improvements, can be used as a powerful tool in this area. The potential scenarios and applications of detecting alterations are innumerable.
[0116] To first summarize, assume that we have a given signal or image which has been positively identified using the basic methods outlined above. In other words, we know its N-bit identification word, its individual embedded code signals, and its composite embedded code. We can then fairly simply create a spatial map of the composite code's amplitude within our given signal or image. Furthermore, we can divide this amplitude map by the known composite code's spatial amplitude, giving a normalized map, i.e. a map which should fluctuate about some global mean value. By simple examination of this map, we can visually detect any areas which have been significantly altered wherein the value of the normalized amplitude dips below some statistically set threshold based purely on typical noise and corruption (error).
[0117] The details of implementing the creation of the amplitude map have a variety of choices. One is to perform the same procedure which is used to determine the signal amplitude as described above, only now we step and repeat the multiplication of any given area of the signal/image with a gaussian weight function centered about the area we are investigating.
[0118] Universal Versus Custom Codes
[0119] The disclosure thus far has outlined how each and every source signal has its own unique set of individual embedded code signals. This entails the storage of a significant amount of additional code information above and beyond the original, and many applications may merit some form of economizing.
[0120] One such approach to economizing is to have a given set of individual embedded code signals be common to a batch of source materials. For example, one thousand images can all utilize the same basic set of individual embedded code signals. The storage requirements of these codes then become a small fraction of the overall storage requirements of the source material.
[0121] Furthermore, some applications can utilize a universal set of individual embedded code signals, i.e., codes which remain the same for all instances of distributed material. This type of requirement would be seen by systems which wish to hide the N-bit identification word itself, yet have standardized equipment be able to read that word. This can be used in systems which make go/no go decisions at point-of-read locations. The potential drawback to this set-up is that the universal codes are more prone to be sleuthed or stolen; therefore they will not be as secure as the apparatus and methodology of the previously disclosed arrangement. Perhaps this is just the difference between ‘high security’ and ‘air-tight security,’ a distinction carrying little weight with the bulk of potential applications.
[0122] Use in Printing, Paper, Documents, Plastic Coated Identification Cards, and other Material where Global Embedded Codes can be Imprinted
[0123] The term ‘signal’ is often used narrowly to refer to digital data information, audio signals, images, etc. A broader interpretation of ‘signal,’ and the one more generally intended, includes any form of modulation of any material whatsoever. Thus, the micro-topology of a piece of common paper becomes a ‘signal’ (e.g. it height as a function of x-y coordinates). The reflective properties of a flat piece of plastic (as a function of space also) becomes a signal. The point is that photographic emulsions, audio signals, and digitized information are not the only types of signals capable of utilizing the principles of the present invention.
[0124] As a case in point, a machine very much resembling a Braille printing machine can be designed so as to imprint unique ‘noise-like’ indentations as outlined above. These indentations can be applied with a pressure which is much smaller than is typically applied in creating Braille, to the point where the patterns are not noticed by a normal user of the paper. But by following the steps of the present disclosure and applying them via the mechanism of micro-indentations, a unique identification code can be placed onto any given sheet of paper, be it intended for everyday stationary purposes, or be it for important documents, legal tender, or other secured material.
[0125] The reading of the identification material in such an embodiment generally proceeds by merely reading the document optically at a variety of angles. This would become an inexpensive method for deducing the micro-topology of the paper surface. Certainly other forms of reading the topology of the paper are possible as well.
[0126] In the case of plastic encased material such as identification cards, e.g. driver's licenses, a similar Braille-like impressions machine can be utilized to imprint unique identification codes. Subtle layers of photoreactive materials can also be embedded inside the plastic and ‘exposed.’
[0127] It is clear that wherever a material exists which is capable of being modulated by ‘noise-like’ signals, that material is an appropriate carrier for unique identification codes and utilization of the principles of the invention. All that remains is the matter of economically applying the identification information and maintaining the signal level below an acceptability threshold which each and every application will define for itself.
[0128] Appendix A Description
[0129] Appendix A to U.S. Pat. No. 5,768,426 contains the source code of an implementation and verification of the foregoing embodiment for an 8-bit black and white imaging system.
[0130] Real Time Encoder
[0131] While the first class of embodiments most commonly employs a standard microprocessor or computer to perform the encodation of an image or signal, it is possible to utilize a custom encodation device which may be faster than a typical Von Neumann-type processor. Such a system can be utilized with all manner of serial data streams.
[0132] Music and videotape recordings are examples of serial data streams—data streams which are often pirated. It would assist enforcement efforts if authorized recordings were encoded with identification data so that pirated knock-offs could be traced to the original from which they were made.
[0133] Piracy is but one concern driving the need for the present invention. Another is authentication. Often it is important to confirm that a given set of data is really what it is purported to be (often several years after its generation).
[0134] To address these and other needs, the system 200 of FIG. 5 can be employed. System 200 can be thought of as an identification coding black box 202 . The system 200 receives an input signal (sometimes termed the “master” or “unencoded” signal) and a code word, and produces (generally in real time) an identification-coded output signal. (Usually, the system provides key data for use in later decoding.)
[0135] The contents of the “black box” 202 can take various forms. An exemplary black box system is shown in FIG. 6 and includes a look-up table 204 , a digital noise source 206 , first and second scalers 208 , 210 , an adder/subtracter 212 , a memory 214 , and a register 216 .
[0136] The input signal (which in the illustrated embodiment is an 8-20 bit data signal provided at a rate of one million samples per second, but which in other embodiments could be an analog signal if appropriate A/D and D/A conversion is provided) is applied from an input 218 to the address input 220 of the look-up table 204 . For each input sample (i.e. look-up table address), the table provides a corresponding 8-bit digital output word. This output word is used as a scaling factor that is applied to one input of the first scaler 208 .
[0137] The first scaler 208 has a second input, to which is applied an 8-bit digital noise signal from source 206 . (In the illustrated embodiment, the noise source 206 comprises an analog noise source 222 and an analog-to-digital converter 224 although, again, other implementations can be used.) The noise source in the illustrated embodiment has a zero mean output value, with a full width half maximum (FWHM) of 50-100 digital numbers (e.g. from −75 to +75).
[0138] The first scaler 208 multiplies the two 8-bit words at its inputs (scale factor and noise) to produce—for each sample of the system input signal—a 16-bit output word. Since the noise signal has a zero mean value, the output of the first scaler likewise has a zero mean value.
[0139] The output of the first scaler 208 is applied to the input of the second scaler 210 . The second scaler serves a global scaling function, establishing the absolute magnitude of the identification signal that will ultimately be embedded into the input data signal. The scaling factor is set through a scale control device 226 (which may take a number of forms, from a simple rheostat to a graphically implemented control in a graphical user interface), permitting this factor to be changed in accordance with the requirements of different applications. The second scaler 210 provides on its output line 228 a scaled noise signal. Each sample of this scaled noise signal is successively stored in the memory 214 .
[0140] (In the illustrated embodiment, the output from the first scaler 208 may range between −1500 and +1500 (decimal), while the output from the second scaler 210 is in the low single digits, (such as between −2 and +2).)
[0141] Register 216 stores a multi-bit identification code word. In the illustrated embodiment this code word consists of 8 bits, although larger code words (up to hundreds of bits) are commonly used. These bits are referenced, one at a time, to control how the input signal is modulated with the scaled noise signal.
[0142] In particular, a pointer 230 is cycled sequentially through the bit positions of the code word in register 216 to provide a control bit of “0” or “1” to a control input 232 of the adder/subtracter 212 . If, for a particular input signal sample, the control bit is a “1”, the scaled noise signal sample on line 232 is added to the input signal sample. If the control bit is a “0”, the scaled noise signal sample is subtracted from the input signal sample. The output 234 from the adder/subtracter 212 provides the black box's output signal.
[0143] The addition or subtraction of the scaled noise signal in accordance with the bits of the code word effects a modulation of the input signal that is generally imperceptible. However, with knowledge of the contents of the memory 214 , a user can later decode the encoding, determining the code number used in the original encoding process. (Actually, use of memory 214 is optional, as explained below.)
[0144] It will be recognized that the encoded signal can be distributed in well known ways, including converted to printed image form, stored on magnetic media (floppy diskette, analog or DAT tape, etc.), CD-ROM, etc. etc.
[0145] Decoding
[0146] A variety of techniques can be used to determine the identification code with which a suspect signal has been encoded. Two are discussed below. The first is less preferable than the latter for most applications, but is discussed herein so that the reader may have a fuller context within which to understand the invention.
[0147] More particularly, the first decoding method is a difference method, relying on subtraction of corresponding samples of the original signal from the suspect signal to obtain difference samples, which are then examined (typically individually) for deterministic coding indicia (i.e. the stored noise data). This approach may thus be termed a “sample-based, deterministic” decoding technique.
[0148] The second decoding method does not make use of the original signal. Nor does it examine particular samples looking for predetermined noise characteristics. Rather, the statistics of the suspect signal (or a portion thereof) are considered in the aggregate and analyzed to discern the presence of identification coding that permeates the entire signal. The reference to permeation means the entire identification code can be discerned from a small fragment of the suspect signal. This latter approach may thus be termed a “holographic, statistical” decoding technique.
[0149] Both of these methods begin by registering the suspect signal to match the original. This entails scaling (e.g. in amplitude, duration, color balance, etc.), and sampling (or resampling) to restore the original sample rate. As in the earlier described embodiment, there are a variety of well understood techniques by which the operations associated with this registration function can be performed.
[0150] As noted, the first decoding approach proceeds by subtracting the original signal from the registered, suspect signal, leaving a difference signal. The polarity of successive difference signal samples can then be compared with the polarities of the corresponding stored noise signal samples to determine the identification code. That is, if the polarity of the first difference signal sample matches that of the first noise signal sample, then the first bit of the identification code is a “1.” (In such case, the polarity of the 9th, 17th, 25th, etc. samples should also all be positive.) If the polarity of the first difference signal sample is opposite that of the corresponding noise signal sample, then the first bit of the identification code is a “0.”
[0151] By conducting the foregoing analysis with eight successive samples of the difference signal, the sequence of bits that comprise the original code word can be determined. If, as in the preferred embodiment, pointer 230 stepped through the code word one bit at a time, beginning with the first bit, during encoding, then the first 8 samples of the difference signal can be analyzed to uniquely determine the value of the 8-bit code word.
[0152] In a noise-free world (speaking here of noise independent of that with which the identification coding is effected), the foregoing analysis would always yield the correct identification code. But a process that is only applicable in a noise-free world is of limited utility indeed.
[0153] (Further, accurate identification of signals in noise-free contexts can be handled in a variety of other, simpler ways: e.g. checksums; statistically improbable correspondence between suspect and original signals; etc.)
[0154] While noise-induced aberrations in decoding can be dealt with—to some degree—by analyzing large portions of the signal, such aberrations still place a practical ceiling on the confidence of the process. Further, the villain that must be confronted is not always as benign as random noise. Rather, it increasingly takes the form of human-caused corruption, distortion, manipulation, etc. In such cases, the desired degree of identification confidence can only be achieved by other approaches.
[0155] The presently preferred approach (the “holographic, statistical” decoding technique) relies on recombining the suspect signal with certain noise data (typically the data stored in memory 214 ), and analyzing the entropy of the resulting signal. “Entropy” need not be understood in its most strict mathematical definition, it being merely the most concise word to describe randomness (noise, smoothness, snowiness, etc.).
[0156] Most serial data signals are not random. That is, one sample usually correlates—to some degree—with the adjacent samples. Noise, in contrast, typically is random. If a random signal (e.g. noise) is added to (or subtracted from) a non-random signal, the entropy of the resulting signal generally increases. That is, the resulting signal has more random variations than the original signal. This is the case with the encoded output signal produced by the present encoding process; it has more entropy than the original, unencoded signal.
[0157] If, in contrast, the addition of a random signal to (or subtraction from) a non-random signal reduces entropy, then something unusual is happening. It is this anomaly that the preferred decoding process uses to detect embedded identification coding.
[0158] To fully understand this entropy-based decoding method, it is first helpful to highlight a characteristic of the original encoding process: the similar treatment of every eighth sample.
[0159] In the encoding process discussed above, the pointer 230 increments through the code word, one bit for each successive sample of the input signal. If the code word is eight bits in length, then the pointer returns to the same bit position in the code word every eighth signal sample. If this bit is a “1”, noise is added to the input signal; if this bit is a “0”, noise is subtracted from the input signal. Due to the cyclic progression of the pointer 230 , every eighth sample of an encoded signal thus shares a characteristic: they are all either augmented by the corresponding noise data (which may be negative), or they are all diminished, depending on whether the bit of the code word then being addressed by pointer 230 is a “1” or a “0”.
[0160] To exploit this characteristic, the entropy-based decoding process treats every eighth sample of the suspect signal in like fashion. In particular, the process begins by adding to the 1 st, 9th, 17th, 25th, etc. samples of the suspect signal the corresponding scaled noise signal values stored in the memory 214 (i.e. those stored in the 1st, 9th, 17th, 25th, etc., memory locations, respectively). The entropy of the resulting signal (i.e. the suspect signal with every 8th sample modified) is then computed.
[0161] (Computation of a signal's entropy or randomness is well understood by artisans in this field. One generally accepted technique is to take the derivative of the signal at each sample point, square these values, and then sum over the entire signal. However, a variety of other well known techniques can alternatively be used.)
[0162] The foregoing step is then repeated, this time subtracting the stored noise values from the 1st, 9th, 17th, 25 etc. suspect signal samples.
[0163] One of these two operations will undo the encoding process and reduce the resulting signal's entropy; the other will aggravate it. If adding the noise data in memory 214 to the suspect signal reduces its entropy, then this data must earlier have been subtracted from the original signal. This indicates that pointer 230 was pointing to a “0” bit when these samples were encoded. (A “0” at the control input of adder/subtracter 212 caused it to subtract the scaled noise from the input signal.)
[0164] Conversely, if subtracting the noise data from every eighth sample of the suspect signal reduces its entropy, then the encoding process must have earlier added this noise. This indicates that pointer 230 was pointing to a “1” bit when samples 1 , 9 , 17 , 25 , etc., were encoded.
[0165] By noting whether entropy decreases by (a) adding or (b) subtracting the stored noise data to/from the suspect signal, it can be determined that the first bit of the code word is (a) a “0”, or (b) a “1”.
[0166] The foregoing operations are then conducted for the group of spaced samples of the suspect signal beginning with the second sample (i.e. 2, 10, 18, 26 . . . ). The entropy of the resulting signals indicate whether the second bit of the code word is a “0” or a “1”. Likewise with the following 6 groups of spaced samples in the suspect signal, until all 8 bits of the code word have been discerned.
[0167] It will be appreciated that the foregoing approach is not sensitive to corruption mechanisms that alter the values of individual samples; instead, the process considers the entropy of the signal as a whole, yielding a high degree of confidence in the results. Further, even small excerpts of the signal can be analyzed in this manner, permitting piracy of even small details of an original work to be detected. The results are thus statistically robust, both in the face of natural and human corruption of the suspect signal.
[0168] Illustrative Variations
[0169] From the foregoing description, it will be recognized that numerous modifications can be made to the illustrated systems without changing the fundamental principles. A few of these variations are described below.
[0170] The above-described decoding process tries both adding and subtracting stored noise data to/from the suspect signal in order to find which operation reduces entropy. In other embodiments, only one of these operations needs to be conducted. For example, in one alternative decoding process the stored noise data corresponding to every eighth sample of the suspect signal is only added to said samples. If the entropy of the resulting signal is thereby increased, then the corresponding bit of the code word is a “1” (i.e. this noise was added earlier, during the encoding process, so adding it again only compounds the signal's randomness). If the entropy of the resulting signal is thereby decreased, then the corresponding bit of the code word is a “0”. A further test of entropy if the stored noise samples are subtracted is not required.
[0171] The statistical reliability of the identification process (coding and decoding) can be designed to exceed virtually any confidence threshold (e.g. 99.9%, 99.99%, 99.999%, etc. confidence) by appropriate selection of the global scaling factors, etc. Additional confidence in any given application (unnecessary in most applications) can be achieved by rechecking the decoding process.
[0172] One way to recheck the decoding process is to remove the stored noise data from the suspect signal in accordance with the bits of the discerned code word, yielding a “restored” signal (e.g. if the first bit of the code word is found to be “1,” then the noise samples stored in the 1 st, 9th, 17th, etc. locations of the memory 214 are subtracted from the corresponding samples of the suspect signal). The entropy of the restored signal is measured and used as a baseline in further measurements. Next, the process is repeated, this time removing the stored noise data from the suspect signal in accordance with a modified code word. The modified code word is the same as the discerned code word, except 1 bit is toggled (e.g. the first). The entropy of the resulting signal is determined, and compared with the baseline. If the toggling of the bit in the discerned code word resulted in increased entropy, then the accuracy of that bit of the discerned code word is confirmed. The process repeats, each time with a different bit of the discerned code word toggled, until all bits of the code word have been so checked. Each change should result in an increase in entropy compared to the baseline value.
[0173] The data stored in memory 214 is subject to a variety of alternatives. In the foregoing discussion, memory 214 contains the scaled noise data. In other embodiments, the unscaled noise data can be stored instead.
[0174] In still other embodiments, it can be desirable to store at least part of the input signal itself in memory 214 . For example, the memory can allocate 8 signed bits to the noise sample, and 16 bits to store the most significant bits of an 18- or 20-bit audio signal sample. This has several benefits. One is that it simplifies registration of a “suspect” signal. Another is that, in the case of encoding an input signal which was already encoded, the data in memory 214 can be used to discern which of the encoding processes was performed first. That is, from the input signal data in memory 214 (albeit incomplete), it is generally possible to determine with which of two code words it has been encoded.
[0175] Yet another alternative for memory 214 is that is can be omitted altogether.
[0176] One way this can be achieved is to use a deterministic noise source in the encoding process, such as an algorithmic noise generator seeded with a known key number. The same deterministic noise source, seeded with the same key number, can be used in the decoding process. In such an arrangement, only the key number needs be stored for later use in decoding, instead of the large data set usually stored in memory 214 .
[0177] Alternatively, if the noise signal added during encoding does not have a zero mean value, and the length N of the code word is known to the decoder, then a universal decoding process can be implemented. This process uses the same entropy test as the foregoing procedures, but cycles through possible code words, adding/subtracting a small dummy noise value (e.g. less than the expected mean noise value) to every Nth sample of the suspect signal, in accordance with the bits of the code word being tested, until a reduction in entropy is noted. Such an approach is not favored for most applications, however, because it offers less security than the other embodiments (e.g. it is subject to cracking by brute force).
[0178] Many applications are well served by the embodiment illustrated in FIG. 7, in which different code words are used to produce several differently encoded versions of an input signal, each making use of the same noise data. More particularly, the embodiment 240 of FIG. 7 includes a noise store 242 into which noise from source 206 is written during the identification-coding of the input signal with a first code word. (The noise source of FIG. 7 is shown outside of the real time encoder 202 for convenience of illustration.) Thereafter, additional identification-coded versions of the input signal can be produced by reading the stored noise data from the store and using it in conjunction with second through Nth code words to encode the signal. (While binary-sequential code words are illustrated in FIG. 7, in other embodiments arbitrary sequences of code words can be employed.) With such an arrangement, a great number of differently-encoded signals can be produced, without requiring a proportionally-sized long term noise memory. Instead, a fixed amount of noise data is stored, whether encoding an original once or a thousand times.
[0179] (If desired, several differently-coded output signals can be produced at the same time, rather than seriatim. One such implementation includes a plurality of adder/subtracter circuits 212 , each driven with the same input signal and with the same scaled noise signal, but with different code words. Each, then, produces a differently encoded output signal.)
[0180] In applications having a great number of differently-encoded versions of the same original, it will be recognized that the decoding process need not always discern every bit of the code word. Sometimes, for example, the application may require identifying only a group of codes to which the suspect signal belongs. (E.g., high order bits of the code word might indicate an organization to which several differently coded versions of the same source material were provided, with low-order bits identifying specific copies. To identify the organization with which a suspect signal is associated, it may not be necessary to examine the low order bits, since the organization can be identified by the high order bits alone.) If the identification requirements can be met by discerning a subset of the code word bits in the suspect signal, the decoding process can be shortened.
[0181] Some applications may be best served by restarting the encoding process—sometimes with a different code word—several times within an integral work. Consider, as an example, videotaped productions (e.g. television programming). Each frame of a videotaped production can be identification-coded with a unique code number, processed in real-time with an arrangement 248 like that shown in FIG. 8. Each time a vertical retrace is detected by sync detector 250 , the noise source 206 resets (e.g. to repeat the sequence just produced) and an identification code increments to the next value. Each frame of the videotape is thereby uniquely identification-coded. Typically, the encoded signal is stored on a videotape for long term storage (although other storage media, including laser disks, can be used).
[0182] Returning to the encoding apparatus, the look-up table 204 in the illustrated embodiment exploits the fact that high amplitude samples of the input data signal can tolerate (without objectionable degradation of the output signal) a higher level of encoded identification coding than can low amplitude input samples. Thus, for example, input data samples having decimal values of 0, 1 or 2 may be correspond (in the look-up table 204 ) to scale factors of unity (or even zero), whereas input data samples having values in excess of 200 may correspond to scale factors of 15. Generally speaking, the scale factors and the input sample values correspond by a square root relation. That is, a four-fold increase in a value of the sampled input signal corresponds to approximately a two-fold increase in a value of the scaling factor associated therewith.
[0183] (The parenthetical reference to zero as a scaling factor alludes to cases, e.g., in which the source signal is temporally or spatially devoid of information content. In an image, for example, a region characterized by several contiguous sample values of zero may correspond to a jet black region of the frame. A scaling value of zero may be appropriate here since there is essentially no image data to be pirated.)
[0184] Continuing with the encoding process, those skilled in the art will recognized the potential for “rail errors” in the illustrated embodiment. For example, if the input signal consists of 8-bit samples, and the samples span the entire range from 0 to 255 (decimal), then the addition or subtraction of scaled noise to/from the input signal may produce output signals that cannot be represented by 8 bits (e.g. −2, or 257). A number of well-understood techniques exist to rectify this situation, some of them proactive and some of them reactive. (Among these known techniques are: specifying that the input signal shall not have samples in the range of 0-4 or 251-255, thereby safely permitting modulation by the noise signal; or including provision for detecting and adaptively modifying input signal samples that would otherwise cause rail errors.)
[0185] While the illustrated embodiment describes stepping through the code word sequentially, one bit at a time, to control modulation of successive bits of the input signal, it will be appreciated that the bits of the code word can be used other than sequentially for this purpose. Indeed, bits of the code word can be selected in accordance with any predetermined algorithm.
[0186] The dynamic scaling of the noise signal based on the instantaneous value of the input signal is an optimization that can be omitted in many embodiments. That is, the look-up table 204 and the first scaler 208 can be omitted entirely, and the signal from the digital noise source 206 applied directly (or through the second, global scaler 210 ) to the adder/subtracter 212 .
[0187] It will be further recognized that the use of a zero-mean noise source simplifies the illustrated embodiment, but is not necessary to the invention. A noise signal with another mean value can readily be used, and D.C. compensation (if needed) can be effected elsewhere in the system.
[0188] The use of a noise source 206 is also optional. A variety of other signal sources can be used, depending on application-dependent constraints (e.g. the threshold at which the encoded identification signal becomes perceptible). In many instances, the level of the embedded identification signal is low enough that the identification signal needn't have a random aspect; it is imperceptible regardless of its nature. A pseudo random source 206 , however, is usually desired because it provides the greatest identification code signal S/N ratio (a somewhat awkward term in this instance) for a level of imperceptibility of the embedded identification signal.
[0189] It will be recognized that identification coding need not occur after a signal has been reduced to stored form as data (i.e. “fixed in tangible form,” in the words of the U.S. Copyright Act). Consider, for example, the case of popular musicians whose performance are often recorded illicitly. By identification coding the audio before it drives concert hall speakers, unauthorized recordings of the concert can be traced to a particular place and time. Likewise, live audio sources such as 911 emergency calls can be encoded prior to recording so as to facilitate their later authentication.
[0190] While the black box embodiment has been described as a stand alone unit, it will be recognized that it can be integrated into a number of different tools/instruments as a component. One is a scanner, which can embed identification codes in the scanned output data. (The codes can simply serve to memorialize that the data was generated by a particular scanner). Another is in creativity software, such as popular drawing/graphics/animation/paint programs offered by Adobe, Macromedia, Corel, and the like.
[0191] Finally, while the real-time encoder 202 has been illustrated with reference to a particular hardware implementation, it will be recognized that a variety of other implementations can alternatively be employed. Some utilize other hardware configurations. Others make use of software routines for some or all of the illustrated functional blocks. (The software routines can be executed on any number of different general purpose programmable computers, such as 80×86 PC-compatible computers, RISC-based workstations, etc.)
[0192] Types of Noise, Quasi-Noise and Optimized-Noise
[0193] Heretofore this disclosure postulated Gaussian noise, “white noise,” and noise generated directly from application instrumentation as a few of the many examples of the kind of carrier signal appropriate to carry a single bit of information throughout an image or signal. It is possible to be even more proactive in “designing” characteristics of noise in order to achieve certain goals. The “design” of using Gaussian or instrumental noise was aimed somewhat toward “absolute” security. This section of the disclosure takes a look at other considerations for the design of the noise signals which may be considered the ultimate carriers of the identification information.
[0194] For some applications it might be advantageous to design the noise carrier signal (e.g. the Nth embedded code signal in the first embodiment; the scaled noise data in the second embodiment), so as to provide more absolute signal strength to the identification signal relative to the perceptibility of that signal. One example is the following. It is recognized that a true Gaussian noise signal has the value ‘0’ occur most frequently, followed by 1 and −1 at equal probabilities to each other but lower than ‘0’, 2 and −2 next, and so on. Clearly, the value zero carries no information as it is used in the service of this invention. Thus, one simple adjustment, or design, would be that any time a zero occurs in the generation of the embedded code signal, a new process takes over, whereby the value is converted “randomly” to either a 1 or a −1. In logical terms, a decision would be made: if ‘0’, then random (1,−1). The histogram of such a process would appear as a Gaussian/Poissonian type distribution, except that the 0 bin would be empty and the 1 and −1 bin would be increased by half the usual histogram value of the 0 bin.
[0195] In this case, identification signal energy would always be applied at all parts of the signal. A few of the trade-offs include: there is a (probably negligible) lowering of security of the codes in that a “deterministic component” is a part of generating the noise signal. The reason this might be completely negligible is that we still wind up with a coin flip type situation on randomly choosing the 1 or the −1. Another trade-off is that this type of designed noise will have a higher threshold of perceptibility, and will only be applicable to applications where the least significant bit of a data stream or image is already negligible relative to the commercial value of the material, i.e. if the least significant bit were stripped from the signal (for all signal samples), no one would know the difference and the value of the material would not suffer. This blocking of the zero value in the example above is but one of many ways to “optimize” the noise properties of the signal carrier, as anyone in the art can realize. We refer to this also as “quasi-noise” in the sense that natural noise can be transformed in a pre-determined way into signals which for all intents and purposes will read as noise. Also, cryptographic methods and algorithms can easily, and often by definition, create signals which are perceived as completely random. Thus the word “noise” can have different connotations, primarily between that as defined subjectively by an observer or listener, and that defined mathematically. The difference of the latter is that mathematical noise has different properties of security and the simplicity with which it can either be “sleuthed” or the simplicity with which instruments can “automatically recognize” the existence of this noise.
[0196] “Universal” Embedded Codes
[0197] The bulk of this disclosure teaches that for absolute security, the noise-like embedded code signals which carry the bits of information of the identification signal should be unique to each and every encoded signal, or, slightly less restrictive, that embedded code signals should be generated sparingly, such as using the same embedded codes for a batch of 1000 pieces of film, for example. Be this as it may, there is a whole other approach to this issue wherein the use of what we will call “universal” embedded code signals can open up large new applications for this technology. The economics of these uses would be such that the de facto lowered security of these universal codes (e.g. they would be analyzable by time honored cryptographic decoding methods, and thus potentially thwarted or reversed) would be economically negligible relative to the economic gains that the intended uses would provide. Piracy and illegitimate uses would become merely a predictable “cost” and a source of uncollected revenue only; a simple line item in an economic analysis of the whole. A good analogy of this is in the cable industry and the scrambling of video signals. Everybody seems to know that crafty, skilled technical individuals, who may be generally law abiding citizens, can climb a ladder and flip a few wires in their cable junction box in order to get all the pay channels for free. The cable industry knows this and takes active measures to stop it and prosecute those caught, but the “lost revenue” derived from this practice remains prevalent but almost negligible as a percentage of profits gained from the scrambling system as a whole. The scrambling system as a whole is an economic success despite its lack of “absolute security.”
[0198] The same holds true for applications of this technology wherein, for the price of lowering security by some amount, large economic opportunity presents itself. This section first describes what is meant by universal codes, then moves on to some of the interesting uses to which these codes can be applied.
[0199] Universal embedded codes generally refer to the idea that knowledge of the exact codes can be distributed. The embedded codes won't be put into a dark safe never to be touched until litigation arises (as alluded to in other parts of this disclosure), but instead will be distributed to various locations where on-the-spot analysis can take place. Generally this distribution will still take place within a security controlled environment, meaning that steps will be taken to limit the knowledge of the codes to those with a need to know. Instrumentation which attempts to automatically detect copyrighted material is a non-human example of “something” with a need to know the codes.
[0200] There are many ways to implement the idea of universal codes, each with their own merits regarding any given application. For the purposes of teaching this art, we separate these approaches into three broad categories: universal codes based on libraries, universal codes based on deterministic formula, and universal codes based on pre-defined industry standard patterns. A rough rule of thumb is that the first is more secure than the latter two, but that the latter two are possibly more economical to implement than the first.
[0201] Universal Codes: 1) Libraries of Universal Codes
[0202] The use of libraries of universal codes simply means that the techniques of this invention are employed as described, except for the fact that only a limited set of the individual embedded code signals are generated and that any given encoded material will make use of some sub-set of this limited “universal set.” An example is in order here. A photographic print paper manufacturer may wish to pre-expose every piece of 8 by 10 inch print paper which they sell with a unique identification code. They also wish to sell identification code recognition software to their large customers, service bureaus, stock agencies, and individual photographers, so that all these people can not only verify that their own material is correctly marked, but so that they can also determine if third party material which they are about to acquire has been identified by this technology as being copyrighted. This latter information will help them verify copyright holders and avoid litigation, among many other benefits. In order to “economically” institute this plan, they realize that generating unique individual embedded codes for each and every piece of print paper would generate Terabytes of independent information, which would need storing and to which recognition software would need access. Instead, they decide to embed their print paper with 16 bit identification codes derived from a set of only 50 independent “universal” embedded code signals. The details of how this is done are in the next paragraph, but the point is that now their recognition software only needs to contain a limited set of embedded codes in their library of codes, typically on the order of 1 Megabyte to 10 Megabytes of information for 50×16 individual embedded codes splayed out onto an 8×10 photographic print (allowing for digital compression). The reason for picking 50 instead of just 16 is one of a little more added security, where if it were the same 16 embedded codes for all photographic sheets, not only would the serial number capability be limited to 2 to the 16th power, but lesser and lesser sophisticated pirates could crack the codes and remove them using software tools.
[0203] There are many different ways to implement this scheme, where the following is but one exemplary method. It is determined by the wisdom of company management that a 300 pixels per inch criteria for the embedded code signals is sufficient resolution for most applications. This means that a composite embedded code image will contain 3000 pixels by 2400 pixels to be exposed at a very low level onto each 8×10 sheet. This gives 7.2 million pixels. Using our staggered coding system such as described in the black box implementation of FIGS. 5 and 6, each individual embedded code signal will contain only 7.2 million divided by 16, or approximately 450 K true information carrying pixels, i.e. every 16th pixel along a given raster line. These values will typically be in the range of 2 to −2 in digital numbers, or adequately described by a signed 3 bit number. The raw information content of an embedded code is then approximately {fraction (3/8)}th's bytes times 450 K or about 170 Kilobytes. Digital compression can reduce this further. All of these decisions are subject to standard engineering optimization principles as defined by any given application at hand, as is well known in the art. Thus we find that 50 of these independent embedded codes will amount to a few Megabytes. This is quite reasonable level to distribute as a “library” of universal codes within the recognition software. Advanced standard encryption devices could be employed to mask the exact nature of these codes if one were concerned that would-be pirates would buy the recognition software merely to reverse engineer the universal embedded codes. The recognition software could simply unencrypt the codes prior to applying the recognition techniques taught in this disclosure.
[0204] The recognition software itself would certainly have a variety of features, but the core task it would perform is determining if there is some universal copyright code within a given image. The key questions become WHICH 16 of the total 50 universal codes it might contain, if any, and if there are 16 found, what are their bit values. The key variables in determining the answers to these questions are: registration, rotation, magnification (scale), and extent. In the most general case with no helpful hints whatsoever, all variables must be independently varied across all mutual combinations, and each of the 50 universal codes must then be checked by adding and subtracting to see if an entropy decrease occurs. Strictly speaking, this is an enormous job, but many helpful hints will be found which make the job much simpler, such as having an original image to compare to the suspected copy, or knowing the general orientation and extent of the image relative to an 8×10 print paper, which then through simple registration techniques can determine all of the variables to some acceptable degree. Then it merely requires cycling through the 50 universal codes to find any decrease in entropy. If one does, then 15 others should as well. A protocol needs to be set up whereby a given order of the 50 translates into a sequence of most significant bit through least significant bit of the ID code word. Thus if we find that universal code number “4” is present, and we find its bit value to be “0”, and that universal codes “1” through “3” are definitely not present, then our most significant bit of our N-bit ID code number is a “0”. Likewise, we find that the next lowest universal code present is number “7” and it turns out to be a “1”, then our next most significant bit is a “1”. Done properly, this system can cleanly trace back to the copyright owner so long as they registered their photographic paper stock serial number with some registry or with the manufacturer of the paper itself. That is, we look up in the registry that a paper using universal embedded codes 4, 7, 11, 12, 15, 19, 21, 26, 27, 28, 34, 35, 37, 38, 40, and 48, and having the embedded code 0110 0101 0111 0100 belongs to Leonardo de Boticelli, an unknown wildlife photographer and glacier cinematographer whose address is in Northern Canada. We know this because he dutifully registered his film and paper stock, a few minutes of work when he bought the stock, which he plopped into the “no postage necessary” envelope that the manufacturing company kindly provided to make the process ridiculously simple. Somebody owes Leonardo a royalty check it would appear, and certainly the registry has automated this royalty payment process as part of its services.
[0205] One final point is that truly sophisticated pirates and others with illicit intentions can indeed employ a variety of cryptographic and not so cryptographic methods to crack these universal codes, sell them, and make software and hardware tools which can assist in the removing or distorting of codes. We shall not teach these methods as part of this disclosure, however. In any event, this is one of the prices which must be paid for the ease of universal codes and the applications they open up.
[0206] Universal Codes: 2) Universal Codes Based on Deterministic Formulas
[0207] The libraries of universal codes require the storage and transmittal of Megabytes of independent, generally random data as the keys with which to unlock the existence and identity of signals and imagery that have been marked with universal codes. Alternatively, various deterministic formulas can be used which “generate” what appear to be random data/image frames, thereby obviating the need to store all of these codes in memory and interrogate each and of the “50” universal codes. Deterministic formulas can also assist in speeding up the process of determining the ID code once one is known to exist in a given signal or image. On the other hand, deterministic formulas lend themselves to sleuthing by less sophisticated pirates. And once sleuthed, they lend themselves to easier communication, such as posting on the Internet to a hundred newsgroups. There may well be many applications which do not care about sleuthing and publishing, and deterministic formulas for generating the individual universal embedded codes might be just the ticket.
[0208] Universal Codes: 3) “Simple” Universal Codes
[0209] This category is a bit of a hybrid of the first two, and is most directed at truly large scale implementations of the principles of this technology. The applications employing this class are of the type where staunch security is much less important than low cost, large scale implementation and the vastly larger economic benefits that this enables. One exemplary application is placement of identification recognition units directly within modestly priced home audio and video instrumentation (such as a TV). Such recognition units would typically monitor audio and/or video looking for these copyright identification codes, and thence triggering simple decisions based on the findings, such as disabling or enabling recording capabilities, or incrementing program specific billing meters which are transmitted back to a central audio/video service provider and placed onto monthly invoices. Likewise, it can be foreseen that “black boxes” in bars and other public places can monitor (listen with a microphone) for copyrighted materials and generate detailed reports, for use by ASCAP, BMI, and the like.
[0210] A core principle of simple universal codes is that some basic industry standard “noiselike” and seamlessly repetitive patterns are injected into signals, images, and image sequences so that inexpensive recognition units can either A) determine the mere existence of a copyright “flag”, and B) additionally to A, determine precise identification information which can facilitate more complex decision making and actions.
[0211] In order to implement this particular embodiment of the present invention, the basic principles of generating the individual embedded noise signals need to be simplified in order to accommodate inexpensive recognition signal processing circuitry, while maintaining the properties of effective randomness and holographic permeation. With large scale industry adoption of these simple codes, the codes themselves would border on public domain information (much as cable scrambling boxes are almost de facto public domain), leaving the door open for determined pirates to develop black market countermeasures, but this situation would be quite analogous to the scrambling of cable video and the objective economic analysis of such illegal activity.
[0212] One prior art known to the applicant in this general area of pro-active copyright detection is the Serial Copy Management System adopted by many firms in the audio industry. To the best of applicant's knowledge, this system employs a non-audio “flag” signal which is not part of the audio data stream, but which is nevertheless grafted onto the audio stream and can indicate whether the associated audio data should or-should not be duplicated. One problem with this system is that it is restricted to media and instrumentation which can support this extra “flag” signal. Another deficiency is that the flagging system carries no identity information which would be useful in making more complex decisions. Yet another difficulty is that high quality audio sampling of an analog signal can come arbitrarily close to making a perfect digital copy of some digital master and there seems to be no provision for inhibiting this possibility.
[0213] The principles of this invention can be brought to bear on these and other problems, in audio applications, video, and all of the other applications previously discussed. An exemplary application of simple universal codes is the following. A single industry standard “1.000000 second of noise” would be defined as the most basic indicator of the presence or absence of the copyright marking of any given audio signal. FIG. 9 has an example of what the waveform of an industry standard noise second might look like, both in the time domain 400 and the frequency domain 402 . It is by definition a continuous function and would adapt to any combination of sampling rates and bit quanitizations. It has a normalized amplitude and can be scaled arbitrarily to any digital signal amplitude. The signal level and the first M'th derivatives of the signal are continuous at the two boundaries 404 (FIG. 9C), such that when it is repeated, the “break” in the signal would not be visible (as a waveform) or audible when played through a high end audio system. The choice of 1 second is arbitrary in this example, where the precise length of the interval will be derived from considerations such as audibility, quasi-white noise status, seamless repeatability, simplicity of recognition processing, and speed with which a copyright marking determination can be made. The injection of this repeated noise signal onto a signal or image (again, at levels below human perception) would indicate the presence of copyright material. This is essentially a one bit identification code, and the embedding of further identification information will be discussed later on in this section. The use of this identification technique can extend far beyond the low cost home implementations discussed here, where studios could use the technique, and monitoring stations could be set up which literally monitor hundreds of channels of information simultaneously, searching for marked data streams, and furthermore searching for the associated identity codes which could be tied in with billing networks and royalty tracking systems.
[0214] This basic, standardized noise signature is seamlessly repeated over and over again and added to audio signals which are to be marked with the base copyright identification. Part of the reason for the word “simple” is seen here: clearly pirates will know about this industry standard signal, but their illicit uses derived from this knowledge, such as erasure or corruption, will be economically minuscule relative to the economic value of the overall technique to the mass market. For most high end audio this signal will be some 80 to 100 dB down from full scale, or even much further; each situation can choose its own levels though certainly there will be recommendations. The amplitude of the signal can be modulated according to the audio signal levels to which the noise signature is being applied, i.e. the amplitude can increase significantly when a drum beats, but not so dramatically as to become audible or objectionable. These measures merely assist the recognition circuitry to be described.
[0215] Recognition of the presence of this noise signature by low cost instrumentation can be effected in a variety of ways. One rests on basic modifications to the simple principles of audio signal power metering. Software recognition programs can also be written, and more sophisticated mathematical detection algorithms can be applied to audio in order to make higher confidence detection identifications. In such embodiments, detection of the copyright noise signature involves comparing the time averaged power level of an audio signal with the time averaged power level of that same audio signal which has had the noise signature subtracted from it. If the audio signal with the noise signature subtracted has a lower power level that the unchanged audio signal, then the copyright signature is present and some status flag to that effect needs to be set. The main engineering subtleties involved in making this comparison include: dealing with audio speed playback discrepancies (e.g. an instrument might be 0.5% “slow” relative to exactly one second intervals); and, dealing with the unknown phase of the one second noise signature within any given audio (basically, its “phase” can be anywhere from 0 to 1 seconds). Another subtlety, not so central as the above two but which nonetheless should be addressed, is that the recognition circuits should not subtract a higher amplitude of the noise signature than was originally embedded onto the audio signal. Fortunately this can be accomplished by merely subtracting only a small amplitude of the noise signal, and if the power level goes down, this is an indication of “heading toward a trough” in the power levels. Yet another related subtlety is that the power level changes will be very small relative to the overall power levels, and calculations generally will need to be done with appropriate bit precision, e.g. 32 bit value operations and accumulations on 16-20 bit audio in the calculations of time averaged power levels.
[0216] Clearly, designing and packaging this power level comparison processing circuitry for low cost applications is an engineering optimization task. One trade-off will be the accuracy of making an identification relative to the “short-cuts” which can be made to the circuitry in order to lower its cost and complexity. A preferred embodiment for the placement of this recognition circuitry inside of instrumentation is through a single programmable integrated circuit which is custom made for the task. FIG. 10 shows one such integrated circuit 506 . Here the audio signal comes in, 500 , either as a digital signal or as an analog signal to be digitized inside the IC 500 , and the output is a flag 502 which is set to one level if the copyright noise signature is found, and to another level if it is not found. Also depicted is the fact that the standardized noise signature waveform is stored in Read Only Memory, 504 , inside the IC 506 . There will be a slight time delay between the application of an audio signal to the IC 506 and the output of a valid flag 502 , due to the need to monitor some finite portion of the audio before a recognition can place. In this case, there may need to be a “flag valid” output 508 where the IC informs the external world if it has had enough time to make a proper determination of the presence or absence of the copyright noise signature.
[0217] There are a wide variety of specific designs and philosophies of designs applied to accomplishing the basic function of the IC 506 of FIG. 10. Audio engineers and digital signal processing engineers are able to generate several fundamentally different designs. One such design is depicted in FIG. 11 by a process 599 , which itself is subject to further engineering optimization as will be discussed. FIG. 11 depicts a flow chart for any of: an analog signal processing network, a digital signal processing network, or programming steps in a software program. We find an input signal 600 which along one path is applied to a time averaged power meter 602 , and the resulting power output itself treated as a signal Psig. To the upper right we find the standard noise signature 504 which will be read out at 125% of normal speed, 604 , thus changing its pitch, giving the “pitch changed noise signal” 606 . Then the input signal has this pitch changed noise signal subtracted in step 608 , and this new signal is applied to the same form of time averaged power meter as in 602 , here labeled 610 . The output of this operation is also a time based signal here labeled as P s-pcn , 610 . Step 612 then subtracts the power signal 602 from the power signal 610 , giving an output difference signal P out , 613 . If the universal standard noise signature does indeed exist on the input audio signal 600 , then case 2 , 616 , will be created wherein a beat signal 618 of approximately 4 second period will show up on the output signal 613 , and it remains to detect this beat signal with a step such as in FIG. 12, 622. Case 1 , 614 , is a steady noisy signal which exhibits no periodic beating. 125% at step 604 is chosen arbitrarily here, where engineering considerations would determine an optimal value, leading to different beat signal frequencies 618 . Whereas waiting 4 seconds in this example would be quite a while, especially is you would want to detect at least two or three beats, FIG. 12 outlines how the basic design of FIG. 11 could be repeated and operated upon various delayed versions of the input signal, delayed by something like {fraction (1/20)}th of a second, with 20 parallel circuits working in concert each on a segment of the audio delayed by 0.05 seconds from their neighbors. In this way, a beat signal will show up approximately every {fraction (1/5)}th of a second and will look like a traveling wave down the columns of beat detection circuits. The existence or absence of this traveling beat wave triggers the detection flag 502 . Meanwhile, there would be an audio signal monitor 624 which would ensure that, for example, at least two seconds of audio has been heard before setting the flag valid signal 508 .
[0218] Though the audio example was described above, it should be clear to anyone in the art that the same type of definition of some repetitive universal noise signal or image could be applied to the many other signals, images, pictures, and physical media already discussed.
[0219] The above case deals only with a single bit plane of information, i.e., the noise signature signal is either there (1) or it isn't (0). For many applications, it would be nice to detect serial number information as well, which could then be used for more complex decisions, or for logging information on billing statements or whatnot. The same principles as the above would apply, but now there would be N independent noise signatures as depicted in FIG. 9 instead one single such signature. Typically, one such signature would be the master upon which the mere existence of a copyright marking is detected, and this would have generally higher power than the others, and then the other lower power “identification” noise signatures would be embedded into audio. Recognition circuits, once having found the existence of the primary noise signature, would then step through the other N noise signatures applying the same steps as described above. Where a beat signal is detected, this indicates the bit value of ‘1’, and where no beat signal is detected, this indicates a bit value of ‘1’. It might be typical that N will equal 32, that way 232 number of identification codes are available to any given industry employing this invention.
[0220] Use of this Technology when the Length of the Identification Code is 1
[0221] The principles of this invention can obviously be applied in the case where only a single presence or absence of an identification signal—a fingerprint if you will—is used to provide confidence that some signal or image is copyrighted. The example above of the industry standard noise signature is one case in point. We no longer have the added confidence of the coin flip analogy, we no longer have tracking code capabilities or basic serial number capabilities, but many applications may not require these attributes and the added simplicity of a single fingerprint might outweigh these other attributes in any event.
[0222] The “Wallpaper” Analogy
[0223] The term “holographic” has been used in this disclosure to describe how an identification code number is distributed in a largely integral form throughout an encoded signal or image. This also refers to the idea that any given fragment of the signal or image contains the entire unique identification code number. As with physical implementations of holography, there are limitations on how small a fragment can become before one begins to lose this property, where the resolution limits of the holographic media are the main factor in this regard for holography itself. In the case of an uncorrupted distribution signal which has used the encoding device of FIG. 5, and which furthermore has used our “designed noise” of above wherein the zero's were randomly changed to a 1 or −1, then the extent of the fragment required is merely N contiguous samples in a signal or image raster line, where N is as defined previously being the length of our identification code number. This is an informational extreme; practical situations where noise and corruption are operative will require generally one, two or higher orders of magnitude more samples than this simple number N. Those skilled in the art will recognize that there are many variables involved in pinning down precise statistics on the size of the smallest fragment with which an identification can be made.
[0224] For tutorial purposes, the applicant also uses the analogy that the unique identification code number is “wallpapered” across and image (or signal). That is, it is repeated over and over again all throughout an image. This repetition of the ID code number can be regular, as in the use of the encoder of FIG. 5, or random itself, where the bits in the ID code 216 of FIG. 6 are not stepped through in a normal repetitive fashion but rather are randomly selected on each sample, and the random selection stored along with the value of the output 228 itself in any event, the information carrier of the ID code, the individual embedded code signal, does change across the image or signal. Thus as the wallpaper analogy summarizes: the ID code repeats itself over and over, but the patterns that each repetition imprints change randomly accordingly to a generally unsleuthable key.
[0225] Towards Steganography Proper and the Use of this Technology in Passing More Complex Messages or Information
[0226] This disclosure concentrates on what above was called wallpapering a single identification code across an entire signal. This appears to be a desirable feature for many applications. However, there are other applications where it might be desirable to pass messages or to embed very long strings of pertinent identification information in signals and images. One of many such possible applications would be where a given signal or image is meant to be manipulated by several different groups, and that certain regions of an image are reserved for each group's identification and insertion of pertinent manipulation information.
[0227] In these cases, the code word 216 in FIG. 6 can actually change in some pre-defined manner as a function of signal or image position. For example, in an image, the code could change for each and every raster line of the digital image. It might be a 16 bit code word, 216 , but each scan line would have a new code word, and thus a 480 scan line image could pass a 980 (480×2 bytes) byte message. A receiver of the message would need to have access to either the noise signal stored in memory 214 , or would have to know the universal code structure of the noise codes if that method of coding was being used. To the best of applicant's knowledge, this is a novel approach to the mature field of steganography.
[0228] In all three of the foregoing applications of universal codes, it will often be desirable to append a short (perhaps 8- or 16-bit) private code, which users would keep in their own secured places, in addition to the universal code. This affords the user a further modicum of security against potential erasure of the universal codes by sophisticated pirates.
CONCLUSION
[0229] In view of the great number of different embodiments to which the principles of my invention can be put, it should be recognized that the detailed embodiments are illustrative only and should not be taken as limiting the scope of my invention. Rather, I claim as my invention all such embodiments as may come within the scope and spirit of the following claims, and equivalents thereto.
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Electronic content data that is copied without authorization can be traced back to its source using steganographically encoded information. Such arrangements are useful, e.g., where electronic content is rendered to an audience—one of whom may be making an illicit recording. In such embodiments, the encoding may be performed as the content is made available to the consumer, e.g., allowing data identifying time and place of rendering to be encoded. The specification details a variety of other steganographic techniques and applications, including conveying different messages using different parts of an image, and conveying record control information with electronic content.
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BACKGROUND OF THE INVENTION
The present invention relates to a novel fluorine-containing polymeric compound which is useful as a material of Langmuir-Blodgett's films as well as to a method for the preparation of such a fluorine-containing polymeric compound.
It is known that polymeric compounds modified with long-chain perfluoroalkyl groups have excellent properties such as water- and oil-repellency, insusceptibility to dust deposition, corrosion resistance and the like so that they are used, for example, for protection and surface modification of electronic circuit boards. Further, they are promising as a material of oxygen-permeable membranes having improved selectivity for the permeation of oxygen relative to other gases by virtue of the high affinity of the perfluoroalkyl groups to oxygen.
A problem in the use of such a polymeric compound having perfluoroalkyl groups introduced into the molecular structure is that the polymer is hardly soluble in solvents due to the water- and oil repellency inherent in the perfluoroalkyl groups so that fluorine-containing polymers are generally not handleable as a material of thin films. In other words, fluorine-containing polymeric compounds can be shaped only with great difficulties into an extremely thin film as an essential element when the polymer is used as a material for surface modification or protection of boards. While it is important that the perfluoroalkyl groups as the functional groups for the oil- and water-repellency and other useful surface properties are oriented toward the surface of the polymeric material in order that the desired performance of surface modification and oxygen permeation can be fully exhibited, a general understanding is that control of such an orientation of polymeric molecules is far from possibility.
One of the inventors has been successful in preparing an ultra-thin film of a controlled molecular orientation by the Langmuir-Blodgett's method from a polyallylamine or polyvinylamine modified with perfluoroalkyl groups as bonded through an amide linkage (see, for example, Japanese Patent Kokai 63-170405. These perfluoroalkyl-modified polyallylamines or polyvinylamines, however, are still not quite satisfactory because the polymer in a solution is subject to gradual hydrolysis of the amide linkages and difficulties are encountered in the handling thereof due to the low solubility of the modified polymer in a solvent.
SUMMARY OF THE INVENTION
The inventors accordingly have continued extensive investigations with an object to develop a method for the preparation of an extremely thin film of a fluorine-containing polymeric compound by utilizing the water-repellency or hydrophobicity of the perfluoroalkyl groups and, as a result, arrived at a discovery that a fluorine-containing polymeric compound quite satisfactory as a material of extremely thin films in respect of the relatively large solubility in organic solvents and stability in an organic solvent against hydrolysis can be obtained when 2- or 4-(perfluoroalkyl-substituted methoxy)phenyl groups are bonded to a part or all of the amino groups in a Polyallylamine through a thiourea linkage -NH-CS-NH- to provide perfluoroalkyl-containing pendant groups.
Thus, the present invention completed on the basis of the above mentioned discovery provides a fluorine-containing polymeric compound which is a novel compound having a structure represented by the general formula
CH.sub.2 --CH(CH.sub.2 --NHhd 2) .sub.m-n CH.sub.2 --CH(CH.sub.2 --NH--CS--NH--Pn--OCH.sub.2 Rf) .sub.n, (I)
in which Rf is a perfluoroalkyl group having 6 to 15 carbon atoms, Pn is a 1,2- or 1,4-phenylene group, m is a positive integer in the range from 10 to 1500, n is a positive integer not exceeding m.
The fluorine-containing polymeric compound of the general formula (I) can be prepared by the reaction of one mole of a polyallylamine expressed by the formula
CH.sub.2 --CH(CH.sub.2 --NH.sub.2) .sub.m, (II)
in which m has the same meaning as defined above, with n moles of a 2- or 4-(perfluoroalkylmethoxy)phenyl isothiocyanate represented by the general formula
RfCH.sub.2 O--Pn--NCS, (III)
in which Rf and Pn each have the same meaning as defined above.
The above defined fluorine-containing polymeric compound of the invention has good solubility in organic solvents to give a solution, from which an LB film, which means a thin film of a monomolecular layer or accumulated multilayer prepared by the well known Langmuir-Blodgett's method, can be readily prepared.
BRIEF DESCRIPTION OF THE DRAWING
FIGS. 1 and 2 each illustrates an F-A isotherm of the LB films prepared from the inventive fluorine-containing polymeric compounds of the general formula (I) with 2- and 4-(perfluoroalkylmethoxy)phenyl groups, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
As is described above, the fluorine-containing polymeric compound of the invention represented by the general formula (I) can be prepared by the reaction of a polyallylamine of the general formula (II) with a 2- or 4-(perfluoroalkyl-methoxy)phenyl isothiocyanate of the general formula (III). The polyallylamine as the starting material of the reaction can be obtained by neutralizing a polyallylamine hydrochloride with a basic compound. The perfluoroalkyl group denoted by Rf in the general formula (I) has 6 to 15 carbon atoms. This is because the water- and oil-repellency of the polymer can be obtained only when the perfluoroalkyl group has 6 or more carbon atoms while the polymer is less soluble in an organic solvent when the perfluoroalkyl group has an excessively large number of carbon atoms. Further, the degree of polymerization of the polymer denoted by m in the general formula (I) should be in the range from 10 to 1500 because no LB films can be prepared with stability when the degree of polymerization of the polymer is too low while a polymer having an excessively large degree of polymerization is less soluble in an organic solvent.
The above mentioned reaction is performed, preferably, by adding the 2- or 4-(perfluoroalkylmethoxy)phenyl isothiocyanate into a solution of the polyallylamine in a reaction medium, which is preferably a mixture of an alcohol and benzene, at a temperature in the range from 5 to 50° C. or, preferably, from 15 to 30° C. The solution of the polyallylamine preferably has a concentration of about 2 to 10 g/liter. The degree of modification, i.e. the ratio of n:m in the general formula (I), of the polyallylamine with the perfluoroalkyl groups bonded through the thiourea linkages can be controlled by suitably selecting the amount of the 2- or 4-(perfluoroalkylmethoxy)phenyl isothiocyanate relative to the polyallylamine. The reaction is complete usually within several minutes to several hours under agitation of the reaction mixture. After completion of the reaction, the reaction mixture is freed from the solvent by evaporation and the residue is washed with water and dried to give a fluorine-containing polymeric product which can be identified by the chemical analysis for the fluorine content and infrared absorption spectrophotometry to be the polymer expressed by the general formula (I).
The polymer is soluble in several organic solvents and the solution can be spread over a water surface to form a monomolecular layer from which an LB film can be easily prepared. Measurement of the F-A isotherms give a conclusion that an increase in the degree of modification, in each of the 2- and 4-isomers of the isothiocyanate compounds, facilitates preparation of an ultra-thin film in which a single perfluoroalkyl-containing pendant group occupies a decreased area. When the degree of modification with the 2-isomer is 100% or the degree of modification with the 4-isomer is 60% or higher, the area occupied by a single perfluoroalkyl-containing pendant group is smaller than the value of 0.28 nm 2 , which is the cross sectional area of a perfluoroalkyl group. This fact indicates that the perfluoroalkyl-containing pendant groups are folded in multifold overlapping in the thin film.
When the degree of modification with the 4-isomer is 80% or higher, several different values of the intrinsic area are taken by the pendant groups indicating that the alignment of the perfluoroalkyl-containing pendant groups are subject to variation depending on the degree of modification.
An LB film was prepared by taking up a single layer or a plural number of the layers spread over a water surface on a glass plate and the film thickness and the critical surface tension γc of the film in dyn/cm relative to n-alkanes were determined. The results were that the value of γc for the LB film prepared from the 2-isomer of the isothiocyanate compound was about 20 dyn/cm when the degree of modification was 5% while the value of γc decreased as the degree of modification increased to reach and level off at about 16 dyn/cm when the degree of modification was 40%. In the LB films prepared from the 4-isomer of the isothiocyanate compound, the value of γc was about 18 dyn/cm when the degree of modification was 5% and the value was decreased as the degree of modification was increased reaching about 10 dyn/cm when the degree of modification was 40% while the value was again increased to reach and level off at about 14 to 22 dyn/cm as the further increased degree of modification was 60% or higher.
The above mentioned values of γc in dyn/cm are considerably close to the value 18.5 dyn/cm on a poly(tetrafluoroethylene) resin indicating that the surface energy of the films is considerably low. In particular, the value of γc on the films prepared from the 4-isomer of the isothiocyanate compound is still smaller than on the previously reported perfluoroalkyl-modified polyvinylamine or polyallylamine. This fact suggests that the perfluoroalkyl group bonded through an ether linkage has high freedom of rotation around the ether linkage so as to contribute to a great decrease in the surface energy. Thus, the films obtained in this manner exhibit excellent water- and oil-repellency and insusceptibility to the deposition of dusts. It was notes in the preparation of the LB films of the perfluoroalkyl-modified polymers prepared from the 4-isomer of isothiocyanate compound, of which the degree of modification was 20% and 40%, that difficulties were encountered in the taking up of the second and following layers from the water surface on to the glass plate. This is presumably due tot he extreme slipperiness of the film surface as a consequence of the upright alignment of the perfluoroalkyl groups on the film surface.
The thickness of the LB films per single layer can be determined in two ways by using a Talystep or by the X-ray diffractometry to give a value of about 2 to 4 nm for the polymers having a degree of modification of 80% or lower with the 2-isomer of the isothiocyanate compound and having a degree of modification of 40% or lower with the 4-isomer of the isothiocyanate compound while the value is increased to about 6 nm or larger when the degree of modification is 100% with the 2-isomer or 60% with the 4-isomer of the isothiocyanate compound presumably due to the overlapping disposition of the (perfluoroalkylmethoxy)phenyl groups to increase the film thickness. Thus, it is possible to freely control the film thickness by adjusting the degree of modification of the polyallylamine with the 2- or 4-(perfluoroalkylmethoxy)phenyl-containing pendant groups which in turn can be controlled by adjusting the amount of the perfluoroalkyl-containing reactant, i.e. 2- or 4-(perfluoro-akylmethoxy)phenyl isothiocyanate, relative to the polyallylamine.
The perfluoroalkyl-containing polymer of the invention is soluble in at least one organic solvent so that an LB film of an extremely small film thickness can be prepared from the solution. The area occupied by a single perfluoroalkyl-containing pendant group in the thus prepared thin film can be controlled by changing the degree of modification by selecting the isomeric position of substitution of the perfluoroalkylmethoxy group on the benzene ring.
The perfluoroalkyl groups are standing on the thus prepared LB film of the inventive polymer to exhibit an extremely low surface energy which can be controlled by adequately selecting the degree of modification with the perfluoroalkyl-containing pendant groups and the isomeric position of the perfluoroalkylmethoxy group on the benZene ring to have a possibility that the critical surface tension γc may have a value ranging from a somewhat larger value than that of poly(tetrafluoroethylene) resins to an extremely small value of about 10 dyn/cm. Such a small value of the surface energy has never been obtained in the prior art on a thin film prepared from a polymer modified with a perfluoroalkyl group bonded to the benzene ring through a covalent bond by the Langmuir-Blodgett's method to control the intramolecular and intermolecular orientations.
In the following, the fluorine-containing polymer of the invention and the method for the preparation thereof are described in more detail by way of examples.
EXAMPLE 1.
A methyl alcohol solution of sodium methylate was prepared by adding 115 mg of metallic sodium to 10 ml of methyl alcohol and, when evolution of hydrogen gas from the solution had ceased, 467 mg of a polyallylamine hydrochloride having an average molecular weight of about 9000 corresponding to an average degree of polymerization of about 100 were added to the solution and stirred in a covered reaction vessel. The precipitates of sodium chloride were removed from the reaction mixture by filtration. The filtrate which was a solution of the free polyallylamine was admixed with 10 ml of methyl alcohol and 5 ml of benzene. The thus diluted solution of the polyallylamine was then admixed at one time with a solution of 134 mg of 2-(perfluoroheptylmethoxy)phenyl isothiocyanate dissolved in a solvent mixture of 4 ml of methyl alcohol and 1 ml of benzene and agitated for 30 minutes at room temperature. The resultant solution was clear and could be used as such as a master solution of the polymer for the preparation of an LB film.
The solvents in the solution were removed by evaporation to dryness under a reduced pressure and the residue was washed with water and dried to give a product which was a polyallylamine having the 2-(perfluoroheptylmethoxy)phenyl groups bonded to the polyallylamine molecules through the thiourea linkages in a degree of modification of 5%. The infrared absorption spectrum of the thus obtained polymer product had a strong absorption band in the wave number region of 1300 to 1100 cm -1 assignable to the carbon-fluorine linkages from which substitution of the fluoroalkyl-containing pendant groups could be confirmed.
Substantially the same synthetic procedure as above was applicable to the preparation of the modified polymers in which the degree of modification with the perfluoroalkyl-containing pendant groups was higher than 5% or the reactant isothiocyanate was the 4 isomer in place of the 2-isomer. Thus, the synthetic procedure with some modification of the reaction conditions was undertaken to prepare perfluoroalkyl-modified polyallylamine polymers having degrees of modification of 5%, 20%, 40%, 60%, 80% and 100%, of which the pendant groups were 2- or 4-(perfluoroheptylmethoxy)phenyl groups bonded through a thiourea linkage. These perfluoroalkyl-modified polyallylamines are referred to as 2-PAPEF-5 to 2-PAPEF-100 and 4-PAPEF-5 to 4 PAPEF 100, respectively, hereinbelow, the numerical figures at the end of each abridgment being the degree of modification in %. The modifications effected in the reaction conditions include some extension of the reaction time to complete the reaction when the intended degree of modification was 40% or higher. When the intended degree of modification was 80% or higher with the 2-isomer of the isothiocyanate compound, the polyallylamine solution in the solvent mixture of methyl alcohol and benzene was admixed with 2-(perfluoroheptylmethoxy)phenyl isothiocyanate and the solvents were removed by evaporation under a reduced pressure to dryness followed by the addition of a 10:1 mixture of benzene and trifluoroethyl alcohol and agitation of the solution for 24 hours at room temperature to effect the polymer reaction in this second solvent mixture.
The degree of modification in each of the above prepared modified polymers was confirmed by conducting chemical analysis for the content of fluorine. Thus, the values of the fluorine content obtained bY the chemical analysis and calculated from the proportion of the reactants used in the reaction were as follows, the latter values given in brackets, for the respective modified polymers. 4-PAPEF-5: 15.7% (17.1%); 4-PAPEF-20: 34.7% (34.8%); 4-PAPEF-40: 41.9% (42.2%); 4-PAPEF-60: 45.4% (45.3%); 4-PAPEF-80: 45.9% (46.9%); and 4-PAPEF-100: 48.0% (48.2%).
EXAMPLE 2.
Langmuir-Blodqett's films of the perfluoroalkyl-modified polyallylamines were prepared in the following manner. Thus, each of the perfluoroalkyl-modified polyallylamines prepared in Example 1 excepting the 2-PAPEF-5 was dissolved in a solvent mixture of trifluoroethyl alcohol and benzene to prepare a polymer solution in a concentration of 0.3 to 1.0×10 -3 moles/liter calculated for the perfluoroalkyl-containing pendant groups. The solvent mixture used for dissolving the 2-PAPEF- 5 was composed of methyl alcohol and benzene. The solution was dropped on and spread over a water surface and the surface pressure was determined according to the Langmuir-Bodgett's method as a function of the area occupied by a single molecule to prepare a so-called F-A isotherm. The results are shown in FIGS. 1 and 2. These graphs indicate that the intrinsic area, i.e. the area occupied by a single perfluoroalkyl group in the film, is 0.87, 0.56, 0.43, 0.37, 0.30 and 0.15 nm 2 for the 2-PAPEF-5, -20, -40, -60, -80 and -100, respectively, and 0.79, 0.46, 0.27 and 0.07 nm 2 for the 4-PAPEF-5, -20, -40 and -60, respectively. No definite intrinsic area could be obtained for the 4-PAPEF-80 and -100 but the values were 0.03 and 0.06 nm 2 , respectively, when the surface pressure was about 20 mN·m -1 .
The ultra-thin film spread over the water surface was taken up on a glass plate at a surface pressure of 20 mN·m -1 in the form of a monomolecular film and accumulated multilayered film. No uniform accumulated film could be obtained from the 4-PAPEF-20 and -40 because the film could not be taken up smoothly on the preceding film already on the glass plate in the second time and thereafter as is mentioned before. Further, no accumulated film could be obtained from the 4-PAPEF-80 and -100 because the first layer on the glass plate was peeled off from the glass plate when taking up of the second film was tried. Each of the LB films thus prepared had good tansparency.
EXAMPLE 3.
The contact angle of an n-alkane was determined on the monomolecular and accumulated LB films taken up on a glass plate in Example 2 and the value of the critical surface tension γc in dyn/cm obtained from the Zisman plot was calculated by the method of least squares to give the results shown in Table 1 below.
TABLE 1______________________________________Modified Poly- Monomolecular Five-fold accumu-allylamine film lated film______________________________________2-PAPEF-5 19.5 19.92-PAPEF-20 17.7 17.62-PAPEF-40 15.8 15.82-PAPEF-60 15.5 15.72-PAPEF-80 15.7 16.22-PAPEF-100 16.4 16.34-PAPEF-5 17.8 17.74-PAPEF-20 14.8 14.5*4-PAPEF-40 9.8 10.4*4-PAPEF-60 13.7 13.54-PAPEF-80 21.8 --**4-PAPEF-100 20.1 --**______________________________________ *The film was uneven in the second and subsequent layers. **Five-fold accumulated film could not be obtained.
EXAMPLE 4.
The LB films prepared in Example 2 were subjected to the measurement of the film thickness in the following two ways.
Thus, a part of the LB film was peeled off from the substrate surface and the level difference between the area covered with the LB film thereon and the bare substrate surface after peeling of the LB film was determined by using a Talystep to give a result that the thickness of a sigle layer was 2.6-3.2 nm, 0.9-1.4 nm, 1.6-2.6 nm, 1.1-2.3 nm, 2.7-5.9 nm and 5.0-10.4 nm in the LB films of 2-PAPEF-5, -20, -40, -60, -80 and -100, respectively, and 1.4-1.7 nm and 6.0-10.3 nm in the LB films of 4-PAPEF-5 and -60, respectively.
Separately, each of the LB films was subjected to the X-ray diffractometry by using the Cu Ka 1 line of the wave-length of 0.154050 nm with an acceleration voltage of 40 kV and beam current of 30 mA to give a diffraction diagram from which the film thickness of the single layer was calculated by utilizing the Bragg's equation to give a value of about 3.7 nm, 1.9 nm, 1.8 nm, 1.9 nm, 3.7 nm and 5.8 nm for the LB films of 2-PAPEF-5, -20, -40, -60, -80 and -100, respectively, and 1.8 nm, 3.4 nm. 3.7 nm and 7.7 nm for the LB films of 4-PAPEF-5 -20 -40 and -60 respectively.
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A novel fluorine-containing polymeric compound represented by the general formula
--CH.sub.2 --CH(CH.sub.2 --NH.sub.2)].sub.m-n --CH.sub.2 --CH(CH.sub.2
--NH--CS--NH--Pn--OCH 2 Rf)] n ,
in which Rf is a perfluoroalkyl group having 6 to 15 carbon atoms, Pn is a 1,2- or 1,4-phenylene group, m is a positive integer in the range from 10 to 1500, n is a positive integer not exceeding m, is prepared by the reaction of one mole of a polyallylamine of the formula
--CH.sub.2 --CH(CH.sub.2 --NH.sub.2)].sub.m,
in which m has the same meaning as defined above, with n moles of a 2- or 4-(perfluoroalkylmethoxy)phenyl isothiocyanate represented by the general formula
RfCH.sub.2 O--Pn--NCS,
in which Rf and Pn each have the same meaning as defined above. Despite the high fluorine content, the polymer is soluble in at least one kind of organic solvents so that Langmuir-Blodgett's films can be prepared from a solution of the polymer. The LB films have an extremely low surface energy and useful as a material for protection and modification of various surfaces.
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BACKGROUND OF THE INVENTION
This invention relates to an improved method of starting or re-starting a flyer frame.
In a flyer frame, when bobbins fitted onto respective spindles on the bobbin support rail become full, they are doffed and empty bobbins are fitted in their place onto the respective spindles. Then, the end of a rove connected to the roller part of the flyer frame is attached to each of the empty bobbins. Heretofore, this attaching operation has been carried out manually by the operator for every rove end.
Referring to FIGS. 1 and 2, there are views illustrating two modes of the attaching operation. In the mode of FIG. 1, a length of a rove greater than the circumference of the empty bobbin 1 is supplied through the roller part by the inching operation of the main motor of the flyer frame so that the supplied rove can pass across the rove end, whereby the rove end is enabled to be manually pressed against the cylindrical surface of the empty bobbin by the supplied rove as well as by a well known presser 3 biased against the empty bobbin.
In the mode shown in FIG. 2, a bobbin 1 is employed which has a rove holding member, such as a napped cloth 4, circumferentially disposed therearound in a position allowing the presser 3 to contact the napped cloth 4 when th bobbin rail is in a position at the begining of the winding operation. At the doffing, the rove is cut at a portion which is a suitable distance away from the extremity of the flyer presser 3, and then the operator strongly presses the cut end against the napped cloth 4 with the presser 3. In both of the two modes illustrated in FIGS. 1 and 2, the operator must carry out the abovenoted manual operation for every empty bobbin. Thus, the operator is required to perform the very complicated rove end attaching operation. Furthermore, since the starting operation of the flyer frame is allowed to commence only upon the completion of the above manual operation for all of the empty bobbins, the down time of the flyer frame is relatively long, resulting in a lower operation efficiency.
In order to remove the abovenoted disadvantages, it has been desired to automatically attach the rove end around the empty bobbin to thereby allow the automatic operation of the flyer frame. However, even through the automatic attaching of the rove end around the empty bobbin has been tried on the bobbin shown in FIG. 2, a favorable result could not be obtained because of the following reason. That is, after the doffing, even if the bobbin rail is raised so as to position the napped cloth 4 of the empty bobbin 1 at the same height as the presser 3 and then the flyer frame is started, a rove slackening phenomenon has occurred between the flyer top and the front rollers (in the case of the flyer frame shown in FIGS. 6A-6E) at each of half or more of the total number of spindles in the flyer frame. Thus, the operator has been required to stop the flyer frame to take necessary manual steps to remove the slack to the rove. Otherwise, the slackened rove would be swung about the flyer neck by means of the centrifugal force applied thereon, resulting in a rove break.
It is accordingly a principal object of this invention to provide a method of starting a flyer frame, which can automatically remove any slack of a rove occurring in the flyer frame and allows the rove end to be automatically attached to the bobbin.
SUMMARY OF THE INVENTION
It has been found that the slack of a rove is actually caused by a time difference between the time point at which the rove is supplied through the top rollers simultaneously with the pushing down of a starting button and the time point at which the winding of the rove commences after the presser has been pressed against the bobbin. Also, it has been found that in order to achieve the abovenoted object, the slack of the rove must be removed before the flyer frame attains its normal high speed operation, because during its normal high speed operation, any slackened rove will be subject to the maximum centrifugal force. On the basis of this knowledge, the method according to this invention includes operating the flyer frame at a relatively low speed for a predetermined time period before the flyer frame is rotated at its normal high speed. During this time period, any slack of the rove can be removed because in the flyer frame the winding of the rove on the bobbin is carried out at a speed which is slightly faster than the rove supply speed (e.g., the speed ratio is 1:1.02).
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention will become more readily apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:
FIGS. 1 and 2 are perspective views illustrating two modes of a manual rove attaching operation according to the prior art;
FIG. 3 is a view illustrating operation speedtime characteristics of a flyer frame according to the prior art method of starting the flyer frame;
FIG. 4 is a power circuit for operating the flyer frame on the basis of the characteristics shown in FIG. 3;
FIG. 5 is a control circuit for the power circuit of FIG. 4;
FIGS. 6A to 6E are elevational view illustrating the sequence of operation steps from the doffing of the full bobbin to the attachment of the rove end of the empty bobbin;
FIG. 7 is an elevational view of a flyer of the hollow pipe type;
FIG. 8 is a view illustrating the operation speed-time characteristics of the flyer frame according to the first embodiment of the starting method of this invention;
FIG. 9 is a power circuit for operating the flyer frame on the basis of the characteristics shown in FIG. 8;
FIG. 10 is a control circuit for controlling the power circuit of FIG. 9 so that the flyer frame is started in accordance with the first embodiment of this invention;
FIG. 11 is a view illustrating the operation speed-time characteristics of the flyer frame according to the second embodiment of this invention; and
FIG. 12 is a control circuit for controlling the power circuit of FIG. 9 so that the flyer frame is started in accordance with the second embodiment of this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In a flyer frame of the type wherein the top of a flyer is supported by a support rail, the necessary steps to attach the end of a rove around an empty bobbin are carried out in the sequence shown in FIGS. 6A to 6E. When the bobbin becomes full, a signal indicating the full bobbin 1' is issued from an auto-counter AC (FIG. 5) to stop the flyer frame (FIG. 6A). Then, a bobbin rail 7 is lowered to the position shown in FIG. 6B, in which the top of the full bobbin 1' is away from the bottom of a flyer guide leg 6. Upon such a lowering, the rove is cut between a presser 3 and the outermost rove layer, and the cut end having length of several centimeters is suspended from the presser 3. In this condition, the full bobbin 1' on the bobbin rail 7 is replaced by an empty bobbin 1 (FIG. 6C), and thereafter, the bobbin rail 7 is lowered until the napped cloth 4 circumferentially mounted on the empty bobbin 1 reaches a height corresponding to the position of the presser 3 (FIG. 6D). Then, the rove end is caught by the napped cloth 4 as shown in FIG. 6E when the presser 3 is pressed against the napped cloth 4. When the flyer frame is started, the empty bobbin 1 starts to rotate to wind the rove thereon.
Heretofore, to carry out the step of FIG. 6E, the operator has been required to perform heavy manual labor in moving the presser 3 toword the empty bobbin 1 and attaching the rove end to the napped cloth 4 while strongly pressing against the napped cloth 4 so that the rove end is firmly caught by the napped cloth 4.
Furthermore, it has been the practice to operate the flyer frame in a manner shown in FIG. 3 by the use of the power and control circuits of FIGS. 4 and 5. That is, upon the pushing down of a start button PB START , an electromagnetic contactor MS1 for a cushion start of a main motor M1 of the flyer frame is energized through the normally closed contacts of an overload relay OL1 to close the MS1 contacts, thereby energizing the main motor M1. Thus, the main motor M1 is cushion started as is well known in the art. At the same time, a timer TR1 is energized. When the timer TR1 counts up to a set time, an electromagnetic contactor MS2 for the normal speed operation of the main motor M1 is energized in lieu of the contactor MS1. Thus, the main motor M1 and accordingly the flyer frame are driven at the normal operation speed as shown in FIG. 3.
Assuming that the flyer frame in the state shown in FIG. 6D is started in the manner described in conjunction with FIGS. 3 to 5, the slack of a rove will occur, as stated in the beginning of the specification, since there is the time difference between the time point at which the rove is supplied through the top rollers 8 simultaneously with the pushing down of the start button PB START , and the time point at which the winding of the rove commences after the presser 3 has been pressed against the bobbin 1. When the flyer frame attains its normal operation speed at the set time of the timer TR1, the slack of the rove, present at the flyer neck in the flyer frame of FIG. 6 and between the top rollers 8 and the flyer top in the flyer frame of FIG. 7, increases to more than during the cushion starting since a higher centrifugal force is applied to the slack of the rove. This results in the rove break.
According to the first embodiment of the starting method of this invention, the flyer frame is operated in accordance with the operation speed-time relationships shown in FIG. 8. The first embodiment of this invention will be described with reference to FIGS. 8 to 10.
Assuming that the flyer frame is in the state shown in FIG. 6D, when the start button PB START is pushed down, a control relay CR2 is energized and an electromagnetic contactor MS A is also energized through the normally closed contacts of a timer TR5 and a contactor MS B . Therefore, an electromagnetic contactor MS C for a low speed operation of the main motor M1 and a timer TR4 are energized, whereby the main motor M1 reaches a predetermined low speed after the lapse of a rise time. When the timer TR4 counts up to a set time, a contactor MS D for a cushion start of the main motor is energized in lieu of the contactor MS C and at the same time a timer TR5 is energized. Therefore, the cushion start of the main motor commences. When the timer TR5 counts up to a set time, an electromagnetic contactor MB B for the normal speed operation of the main motor is energized to drive the main motor at the normal operation speed.
At the same time as the commencement of the flyer frame starting, the supply of the rove commences. However, a certain period of time is required until the presser 3 is pressed against the napped cloth 4. Also, after this period of time, an additional time period is required until the rove end is firmly caught by the napped cloth 4. Therefore, during these time periods, the rove supplied through the front rollers 8 is slackened between the front rollers 8 and the flyer top 9 in the case of the flyer frame shown in FIG. 7 and at the flyer neck in the case of the flyer frame shown in FIG. 6. However, since the flyer frame is adapted to drive to bobbin at a rove winding speed slightly faster than a rove supply speed and since the flyer frame is operated at the predetermined low speed for the period of the set time of the timer TR4 minus the rise time of the motor prior to the normal speed operation of the flyer frame, any slack of the rove can be removed during said period.
The starting method illustrated in FIG. 8 is also applicable to the re-starting of the flyer frame, e.g. after a broken rove has been ended. Heretofore, since the flyer frame has been started in the manner shown in FIG. 3 by pushing down the start button PB START (FIG. 5), the ended portion of the rove would be broken again if the manner of FIG. 3 was applied to the re-starting of the flyer frame after the rove ending. Therefore, repeated inching operations have had to be carried out until the ended portion of the rove is wound on the bobbin so that a rove break does not occur again.
Referring back to FIG. 8, if a rove break occurs, the flyer frame will be stopped in the known manner. After the stoppage of the flyer frame, a switch PB INCH (FIG. 10) is operated to inch the flyer into a favourable angular position to perform subsequent operations such as a rove ending. After the rove ending, the start button PB START can be pushed down, since according to this invention the flyer frame attains the normal operation speed after it has been operated for the predetermined time period at the relatively low speed, which does not apply a sufficient tension on the ended portion of the rove to cause it to be broken again.
In the first embodiment, although the contactor MS C for the low speed operation is energized at the start, the contactor MS D can be energized prior to the energization of the contactor MS C to provide a cushion start.
The second embodiment of this invention will be described with reference to FIGS. 11 and 12.
The second embodiment is the same as the first embodiment, except that when the start button PB START is pushed down, the contactor MS B for the normal speed operation is first energized so that the main motor is abruptly accelerated. This increased acceleration applies a sufficient centrifugal force on the presser 3 to cause it to be moved to the napped cloth 4 in a shorter time and pressed more strongly thereagainst. Thus, it will be understood that according to the second embodiment, the degree of rove slacking upon the starting of the flyer frame is decreased and the rove end is firmly held by the napped cloth 4.
Assuming that the flyer frme is in the state shown in FIG. 6D, in FIGS. 11 and 12, when the start button PB START is pushed down, the control relay CR2 is energized to thereby energize the electromagnetic contactor MS B for the normal speed operation of the flyer frame and the timer TR3 through the closed normally open contacts of the relay CR2. This causes the main motor M1 (FIG. 9) of the flyer frame to be started with the full voltage and abruptly accelerated within a decreased time period of b-a as shown in FIG. 11. Thus, the presser 3 can be quickly and strongly pressed against the napped cloth 4 of the empty bobbin 1. When the timer TR3 counts up to a set time, the contactor MS B is deenergized and the contactor MS C for the low speed operation of the flyer frame is energized under the control of the motor primary voltage. Thus, the main motor M1 is driven at the low speed for the predetermined time period determined by the set time of the timer TR4, during which any slack of the rove can be removed in the same manner as in the first embodiment. When the timer TR4 counts up to the set time at the time point c, the contactor MS C for the low speed operation is deenergized and the contactor MS D for the cushion start of the flyer frame is energized to thereby connect the motor M1 to the higher voltage tap of the three-phase autotransformer (FIG. 9), increasing the motor primary voltage. This allows the speed of the flyer frame motor M1 to be gradually increased to the normal operation speed. The timer TR5, energized at the same time as the counting up of the timer TR4, up at a time point d, at which point the motor M1 reaches the normal operation speed and the contactor MS B for the normal speed operation is energized in lieu of the contactor MS D . Then, the flyer frame continues to operate at this normal operation speed until the bobbin becomes full with the rove.
In FIG. 12, letters KR C denote a catch coil, KR T a trip coil, and DR contacts of a keep relay. By these elements, the starting for winding the rove on the empty bobbin is distinguished from the re-starting after the stoppage due to the rove break possibly occurring during the normal speed operation. After the catch of the keep relay (after the completion of the starting for winding), the cushion starting is carried out during the time period d-c as shown in FIG. 11.
In these embodiments of this invention, although the autotransformer starting method has been used to start the main motor M1 of the flyer frame, the main motor M1 can be started as shown in FIGS. 8 and 11 by the use of any one of the other known starting methods, such as reactor starting, stator resistance starting, primary voltage control (using thyristors), and motor pole number changing methods.
Furthermore, in these embodiments of this invention, the normal operation speed of the main motor M1 is generally within the limits of 800 r.p.m. to 1,100 r.p.m.; the low operation speed of the main motor M1 determined by the contactor MS C for the low speed operation changes between 200 r.p.m. and 300 r.p.m. (preferably about 250 r.p.m.) depending on the thickness of the rove; the set time of the times TR4 for defining the time period of the low speed operation may be about 15 sec. or more, preferably between 15 sec. and 20 sec. with a view to not decreasing the operation efficiency; and the set time of the timer TR3 for defining the time period during which the full voltage is impressed to the main motor terminals when starting is about 0.3 sec. to 0.4 sec., which assures that all the pressers can firmly contact the napped cloths of the bobbins.
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The slack of a rove is actually developed by a time difference between the time point at which the rove is supplied simultaneously with the pushing down of a start button of a flyer frame, and the time point at which the winding of the rove commences after the presser has been pressed against the bobbin. The removing of the rove slack must be performed before the flyer frame attains its normal high speed operation. On the basis of this knowledge, the method according to this invention includes operating the flyer frame at a relatively low speed for a predetermined time period before the flyer frame is rotated at its normal high speed. During this time period, any slack of the rove can be removed.
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FIELD
[0001] The application pertains to multi-modal communications systems. More particularly, the application pertains to such systems which incorporate multiple, wireless communications systems of substantially different wavelengths which can operate in tandem.
BACKGROUND
[0002] Various types of wireless RF communications systems are known for use in building automation, monitoring and control systems. While useful, there are limitations as to the type of functionality that such systems can provide. Such systems can also suffer from eavesdropping and exposure to foreign third parties along with power related limitations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] FIG. 1 illustrates a system in accordance herewith.
[0004] FIG. 2 is a block diagram of an illumination element in accordance herewith; and
[0005] FIG. 3 is a block diagram of a radio frequency enabled device in accordance herewith.
DETAILED DESCRIPTION
[0006] While disclosed embodiments can take many different forms, specific embodiments hereof are shown in the drawings and will be described herein in detail with the understanding that the present disclosure is to be considered as an exemplification of the principles hereof, as well as the best mode of practicing same, and is not intended to limit the claims hereof to the specific embodiment illustrated.
[0007] Visible Light Communication (VLC) is a non-disruptive wireless communications solution made possible by the advent of light emitting diode (LED) building illumination systems. A key property of LED lighting is that it can be amplitude modulated at very high rates, providing good data transmission without affecting the illumination function itself.
[0008] VLC has several advantages over traditional RF communication systems; the operation is unlicensed, the transmission path is contained (by walls), so spatial re-use is not an issue, nor is eavesdropping beyond the room/building walls a problem. Further the cost of transmission and reception is low. Since wavelengths are short, there are good ranging and location opportunities. The downsides of VLC are short operating range and of course the lights need to be powered and modulated to operate as a communications service in addition to providing illumination.
[0009] In fact RF communications and VL communications operating together offer several complementary properties. As discussed below, complementary or tandem operation offers additional control configurations not available with a single wireless system.
[0010] Examples of functionality available with multi-modal communications systems follow. The particular characteristics of the different types of communications systems can be selected and allocated to implement various functions which might be difficult or expensive to implement with one type of communications system but which can be very cost effectively provided with the second type of system.
[0011] Those of skill will understand that the following are exemplary only and are not limitations hereof. Numerous additional possibilities are available with multiple complimentary communications systems.
[0012] In particular the following exemplary functionality is possible with VLC and RF communication systems operating in tandem. The following examples contribute to extending battery life of wireless units. Synchronized sirens, or sounders, can be provided for battery-powered smoke detectors. In such instances, if one goes, all go sound operation is possible. Redundant operation preserves batteries in the RF emergency devices by using VLC communications when the lights are on, and RF when they are not.
[0013] Synchronizing optical signals can be sent to RF transceivers at much lower operating current in the battery powered device than would be possible if synchronization was via the RF signals. In-building location services can be provided. In this regard, a security system portable tablet control unit, or phone could use its built-in camera to detect the nearest modulated LED light fixture, and therefore its location, again enabling smart room operation.
[0014] In yet another aspect, smart room RF based functionality can be augmented. For example, a manually operated light switch can indicate occupancy and can trigger other devices in the illuminated area when the light is turned on or energized. A shade or blind can automatically be closed when the light is turned on. Similarly, the heat could be turned on, or up or a door locked, or unlocked in response to a light being turned on. Status requests to remote detectors could reduce overall quiescent current if the request to the battery powered detector was via VLC with the sensor response via RF. Those of skill will understand that these are examples, and not limitations hereof.
[0015] In principle, the enabling technology includes an ability to amplitude modulate individual LED light fixtures in conjunction with the capability of high speed photo diodes to detect messages in building control products and portable devices. As those of skill will understand, the examples disclosed here require various data protocols—both RF and visible light to enable timing accuracy for timing and synchronization. Addressable lighting fixtures and control devices that can detect RF and/or VLC signals are useful in the present context.
[0016] Further, elements of the VLC system can transmit a change of status indication, for example, “turning-off”, to alert local RF devices. Alternately, a change of status message indicating “light on” could also be transmitted.
[0017] FIG. 1 illustrates a system 10 , in accordance herewith installed in a building B. Building B has two floors indicted by spaces S 1 , S 2 . A plurality 12 of detectors and/or output devices 12 a, 12 b, 12 c . . . 12 n which can be in wireless RF communication R are illustrated scattered throughout the building B as would be understood by those of skill in the art.
[0018] The plurality 12 can include fire or gas detectors, intrusion or other security monitoring detectors, output devices such as audible or visual alarm indicating devices as well as solenoids or other types of actuators all without limitation. For example, unit 12 a can be implemented as a fire detector, 12 b, could be implemented as a gas detector and 12 c could be implemented as an intrusion detector. Unit 12 d can be an actuator which could implement a linear motion in response to a received command. All such devices can be in wireless RF communication R with a displaced monitoring system control unit 16 .
[0019] Other devices in a plurality 18 can emit visible light and provide both an illumination function as well as modulated beams of radiant energy V which can provide a second communications mode which can compliment the above noted RF communications mode of operation. For example devices 18 a, 18 b, 18 c . . . 18 p can provide illumination to the respective adjacent regions such as S 1 - 1 , S 1 - 2 . . . S 1 -n in space S 1 , or S 2 - 1 , S 2 - 2 in space S 2 . In addition such devices can emit modulated beams of visible radiant energy V which can provide additional, or different control functions than provided by the wireless RF system.
[0020] For example, manually operable switch 20 can be used to turn on a light emitting diode source 18 b which can not only provide illumination in sub-region S 2 - 1 but also emit the above noted modulated, visible, radiant energy V which can in turn cause actuator 12 d to open or close a curtain, or shade, C, or unlock a door. Radiant energy signals V from switch 20 could also provide synchronization signals to detectors, or output devices 12 b,c. The devices 12 b, c can then communicate via RF communication links R with the monitoring system 16 or other units in the building B.
[0021] FIG. 2 is a block diagram of an illumination element, such as 18 i in accordance herewith. Element 18 i includes a housing 40 which carries a source 42 of visible light. For example, one or more light-emitting-diodes. Control circuits 44 can energize the source 42 to provide both visible light for illumination and a modulated, coded, data sequence which can be detected and responded to by other units in the vicinity of element 18 i.
[0022] Optionally, unit 18 i can also include an RF transceiver 46 and one or more sensors 48 as desired. Those of skill will understand that exemplary illumination element 18 i can implement a variety of communications modes in accordance herewith to maximize battery life of the various wireless units 12 i or to provide additional “smart house” functionality as desired.
[0023] FIG. 3 is a block diagram of a detector or actuator 12 i such as 12 a - 12 d. The unit 12 i can be carried by a housing 50 and include alight sensors 52 which can respond to coded messages from element 18 i as described above. Control circuits 54 can decode messages received from sensors 52 , and/or RF messages received from transceiver 56 . The units such as 12 i can carry one or more condition sensors and/or actuators as at 58 all without limitation. Units, such as 12 i can be energized by batteries B whose life can be extended by the above described processes of using multi-model communications.
[0024] From the foregoing, it will be observed that numerous variations and modifications may be effected without departing from the spirit and scope of the invention. It is to be understood that no limitation with respect to the specific apparatus illustrated herein is intended or should be inferred. It is, of course, intended to cover by the appended claims all such modifications as fall within the scope of the claims.
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A system having first and second different communication system can include a plurality of illumination devices having modulatable optical output signals. A plurality of building control units are in wireless communications with one another. Representative units could include ambient condition detectors, intrusion detectors, output devices or actuators. At least some of the units include optical sensors responsive to the modulatable optical output signals, and, wherein in responsive to received, modulated optical output signals, the respective control unit carries out a predetermined function.
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BACKGROUND OF THE INVENTION
There are known in the prior art merchandising machines of the helical feed type adapted to deliver articles in response to rotary movement of one or more helices between the turns of which articles to be dispensed are disposed. Most machines of this type are intended to deliver merchandise in bags such, for example, as bags of chips and the like. It is desirable that such a machine also have the capability of delivering other articles such, for example, as packets of gum or mints or the like. Some attempts have been made in the prior art to adapt the bagged merchandise delivery units to dispense articles such as packets of gum and mints. Adaptation of such a unit to the delivery of articles of the latter type in the prior art involves a number of drawbacks. First, and most important, the amount of space occupied by the unit is excessively large for the capacity thereof. In addition, machines of the prior art generally involve relatively complicated mechanism for selectively operating the units of the machine.
We have invented a delivery unit for a helical feed merchandising machine which unit is especially adapted to deliver articles such as packets of gum or mints or the like. Our unit has a large capacity relative to the space occupied in the machine. It is certain in operation. It is simple in construction.
SUMMARY OF THE INVENTION
One object of our invention is to provide a gum and mint delivery unit for a merchandising machine of the helical feed type.
Another object of our invention is to provide a gum and mint delivery unit for a helical feed merchandising machine which unit has a large capacity for the space occupied thereby.
A further object of our invention is to provide a gum and mint delivery unit for a helical feed merchandising machine which unit is certain in operation.
Yet another object of our invention is to provide a gum and mint delivery unit for helical feed merchandising machine which unit is simple in construction.
Other and further objects of our invention will appear from the following description.
In general, our invention contemplates the provision of a gum and mint delivery unit for a merchandising machine of the helical feed type in which unit a product separator extends axially through a helix mounted for rotary movement between the unit walls which extend from front to back of a shelf of the machine and in which drive means rotates the helix through one half of a revolution on each operation of the unit to cause a cam formed at the front of the helix to deliver an article over the front edge of the shelf so that articles are dispensed alternately from one side of the separator and the other side thereof on successive operations of the unit.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings which form part of the instant specification and which are to be read in conjunction therewith and in which like reference numerals are used to indicate like parts in the various views:
FIG. 1 is a front elevation of a merchandising machine of the helical feed type which is provided with our gum and mint delivery unit.
FIG. 2 is a sectional veiw through one shelf of the machine shown in FIG. 1 illustrating our gum and mint delivery unit.
FIG. 3 is a fragmentary front elevation of a shelf of the machine shown in FIG. 1 illustrating two of our gum and mint delivery units with parts broken away and with other parts shown in section.
FIG. 4 is a fragmentary sectional view of the unit shown in FIG. 2 taken along the line 4--4 of FIG. 2.
FIG. 5 is a schematic view of one form of electrical circuit which may be used to control our gum and mint delivery units.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, a merchandising machine, indicated generally by the reference character 10, of the spiral feed type, includes a cabinet 12, having a door 14 supported on the cabinet by means of hinges 16 and 18. The machine 10 includes a window 20 in door 14 through which merchandise to be delivered can be viewed by the customer. We provide the main door 14 with a delivery door 22 adapted to be opened for access to merchandise delivered by one of the units to be described hereinbelow. A coin slot 24 in the door 14 permits coins to be introduced into the machine in anticipation of making a purchase. The buttons of an array 26 of push buttons are adapted to be operated to permit the customer to select a desired article of merchandise. As is conventional, we provide the door 14 with a lock 28 adapted to secure the door in closed position on the cabinet 12. A coin return recess 30 permits the customer to receive change or to have his coins returned to him in the event that he does not wish to complete a purchase.
The particular embodiment of the machine 10 illustrated in the drawings includes four respective merchandising levels indicated generally by the reference characters 32, 34, 36 and 38. In this embodiment each of the levels 32, 34 and 36 is made up of a plurality of main merchandise delivery units each of which is indicated generally respectively by the reference character 40. These units 40 are adapted to deliver articles of bagged merchandise, for example. The construction and operation of these units are described more fully in our copending application Ser. No. 454,118, filed Mar. 25, 1974, for "Helical Feed Merchandising Machine".
The lowest level 38 of the machine 10 includes a number of delivery units indicated generally by the reference character 42 which units are adapted to deliver articles of merchandise such, for example, as bars of candy. These units 42 are described in detail in our copending application Ser. No. 453,885, filed Mar. 25, 1974, for "Candy Bar Delivery Unit for Helical Feed Merchandising Machine". Also included in the level 38 are a number of our delivery units indicated generally by the reference character 44 which units 44 are adapted to deliver articles such, for example, as packets of gum or mints or the like.
The units 44 are supported on a shelf 46 of the level 38 of the merchandising machine. Shelf 46 is formed with a rear wall 48 carrying a rearwardly extending flange 50 along its upper edge. A plurality of partitions 52 secured to the shelf 46 by any suitable means divide the shelf into a number of compartments, each of which houses one of the units 42 or 44. Each unit includes a helix, indicated generally by the reference character 54, which is provided with a pair of closely spaced turns 56 at the rear thereof. We so form the first 180° at the front of the helix, identified by the reference character 58, as to have zero pitch. The next 90° of the helix, identified by the reference character 60, is formed with a greater pitch than the remainder of the helix so that the distance between the terminus of this 90° section and a corresponding point on the preceding turn is one-and-a-half times the distance between corresponding points on adjacent normal turns of the helix. As will more fully be pointed out hereinbelow, this arrangement provides a cam at the front of the helix for ensuring that the frontmost article is delivered over the edge of the shelf 46 in response to one half of a revolution of the helix 54.
A spider, indicated generally by the reference character 62 at the rear of each of the units 44, has a hub 64 from which a plurality of resilient arms 66, 68, 70 and 72, extend to connectors 74 and 76 which respectively connect pairs of arms 64 and 66 and 68 and 70. We provide the connectors with pairs of fingers 78 having grooves therein for receiving the turns 56 of the helix. A shaft 80, rotatably supported in the back 48, carries the spider 62 for rotation therewith. We form each helix 54 with a tail 81 adapted to be engaged by the bend connecting the arm 66 to the connector 74 of the spider 62 to ensure that the helix 54 turns with the spider and to prevent any slippage between the spider and the helix.
Each unit 44 includes an elongated product divider 82 having a rectangular cross sectional shape. We provide the base of each of the product dividers 82 with a re-entrant slot 84. A front divider supporting clip 86 is formed with an insert portion 88 adapted to be inserted into the slot 84 in the base of the product divider. Each of the clips 86 is provided with a pair of resilient legs 90 and 92 and with a cover portion 94 extending upwardly so as to cover the front of the product divider 82. After the insert 88 has been placed in the base slot 84, legs 90 and 92 are moved downwardly into an opening 96 in the shelf 46 and snapped in position therein securely to hold the front of the product divider 82 in position. It will be seen that the product divider 82 extends axially of the helix 54 and that the front turn of the helix is located between the base 46 and the portion of the clip 86 which is inserted into the product divider base slot. Thus, the front clip further serves to retain the helix in position in the unit.
Each of the units 44 includes a rear product divider support 98 formed with an insert portion 100 adapted to be received in the base slot 84 at the rear of the unit. The rear support 98 has a collar 102 adapted to be received by shaft 80.
We provide a respective motor and gearbox 104 for driving the shaft 80 of each of the units. Each of the motor and gearbox units 104 includes a cam 106 which we have illustrated as being carried by the portion of shaft 80 behind the back wall 48. Cam 106 is formed with a pair of detent recesses 108 and 110 which are located at diametrically opposite positions around the periphery of the cam 106. A detent 112 is carried by a spring arm 114 supported on the rear wall 48. Arm 114 normally urges the detent 112 into engagement with the cam 106. We select a relatively heavy spring material for the spring 114 so that the detent 112 exerts a positioning action on the helix 54 as it moves into one of the recesses 108 and 110. We also so arrange the detent and recesses that approximately 10° of revolution of the shaft 80 is required before spring 114 strikes the actuator 118 of a switch 116 adapted to complete the circuit of the motor 104 for the period of time during which the actuator is engaged by the spring arm. This prevents a dishonest person from momentarily closing a push button switch to be described hereinbelow to cause the unit to operate and, at the same time, receive his purchase price back.
We provide each of the units 44 with a price setting switch 120 adapted to be moved among four different positions to permit the merchandise to be sold at one of four prices as desired.
We provide each unit 42 and 44 with a flag 119 carrying selection and pricing information. Any suitable means such as a spring 121 or the like suspends the flag 119 in front of the unit. For purposes of simplicity not all of the flags are shown.
Referring now to FIG. 5, one form of control circuit which may be employed in a merchandising machine including our units 44 includes a transformer 124 adapted to supply power to lines 126 and 128. We connect lines 126 and 128 to a coin mechanism 130 of any suitable type known to the art adapted to energize lines 132, 134, 136 and 138 in response to the deposit therein of sums of money corresponding to four respective prices, for example. The coin mechanism 130 includes a coin return electromagnet 140. Each of the price setting switches 120a and 120b includes an arm 142a or 142b adapted selectively to be moved into engagement with one of four contacts in response to the positioning of the element 122a or 122b of the switch. We connect the respective contacts of each of the switches 120a and 120b to the four price lines 132, 134, 136 and 138 leading out of the coin mechanism 130. The moveable contacts 142a and 142b of the switches 120a and 120b are respectively connected to one terminal of the motors 104a and 104b. The cycle switches 116a and 116b include respective moveable contacts 144a and 144b normally in engagement with upper contacts and adapted to be moved into engagement with lower contacts in response to the operation of the cam 100a and 100b. While we have shown a four price system it will be understood that we may provide as many prices as desired.
The control circuit includes a transfer relay TR which is normally energized to hold respective switches TR1 to TR5 in the positions shown. When winding TR drops out switches TR1 to TR5 move to alternate positions indicated in broken lines in FIG. 5. We connect the moveable contacts of switches TR1 to TR4 to the line 128. The moveable contact of switch TR5 is connected to the moveable contact of a push button switch PB2 of the array 26 associated with the unit 44b. This moveable contact of switch PB2 normally engages a contact connected to the moveable contact of a switch PB1 normally in engagement with the upper contact shown in FIG. 5. When either of the switches PB1 or PB2 is actuated, its moveable element engages a respective lower contact connected to the upper terminal of the motor 104a or 104b. We connect the normally engaged lower contact of switch TR4 to the coin return electromagnet 140 in the coin totalizer 130. The upper contacts of the respective switches TR1 to TR4 are connected to the price lines 138, 136, 134 and 132.
As can readily be seen from the arrangement shown in FIG. 5, with power on winding TR normally is energized through the cycle switches 116a and 116b. When a sum in coins or bills or the like sufficient to permit a purchase to be made has been inserted in the coin mechanism 130, a selection may be made. At the same time, the price lines 132, 134, 136 and 138 are energized in accordance with the sum which has been deposited in the coin mechanism 130. Under these conditions, when the customer makes a selection he pushes one of the push buttons PB1 or PB2 to complete the circuit of the associated motor 104a or 104b which drives the corresponding cam 106 so that after a predetermined rotation of the cam the corresponding switch 116a or 116b is actuated to move its contact arm 144a or 144b out of engagement with the upper contact and into engagement with the lower contact. As soon as the moveable contact 144a or 144b leaves the upper contact, winding TR is deenergized to permit the switches TR1 to TR5 to move to the broken line positions. When this occurs, electromagnet 140 is deenergized and the credit is removed from the credit line. The motor continues to rotate until the detent drops into the next recess.
In operation of our gum and mint unit for a helical feed merchandising machine, when the motor and gearbox unit 104a, for example, is activated in the manner described above, the associated helix 54a rotates in the direction of the arrow X in FIG. 3. Assuming that the packet of merchandise to the left of the axis of the helix is furthest forward as the helix rotates through 180° it will be the first dispensed. For purposes of illustration we have illustrated this package in dot-dash lines and have identified it by the reference character A in FIG. 3. The package next furthest forward which is to the right of the helix as viewed in FIG. 3 has been indicated by the reference character B. As the helix travels through 180°, this packet B will be advanced to a position at which it will be the next dispensed upon the next operation of the unit in the course of which the helix rotates through 180°. As can be seen by reference to FIG. 3, initially the helix 44a is in a position at which its forward end is approximately at the top center of the unit. Following the first operation thereof, the end will be adjacent the bottom center of the unit. By way of example, we have illustrated this position of the helix 44b. Further we have designated the next package behind package A by the reference character C. That is to say, the position of the helix 54a in FIG. 3 illustrates the condition of a unit before its first operation, while the position of the helix 54b indicates the condition of a unit after its first operation. It will readily be appreciated that after the second operation of the helix, it will return to the condition shown for the helix 54a in FIG. 3.
It will be seen that we have accomplished the objects of our invention. We have provided a delivery unit for a helical feed merchandising machine which unit is especially adapted to deliver articles of merchandise such as packets of gum or packets of mints or the like. Our unit has a very large capacity for the space occupied thereby. It is certain in operation. It is simple in construction.
It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of our claims. It is further obvious that various changes may be made in details within the scope of our claims without departing from the spirit of our invention. It is, therefore, to be understood that our invention is not to be limited to the specific details shown and described.
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A gum and mint delivery unit for a merchandising machine of the helical feed type in which a product separator extends axially through a helix mounted for rotary unit between the unit walls extending from front to back of a shelf of the machine to permit packets of gum or mints or the like to be arranged vertically between the turns of the helix on opposite sides of the separator and in which a motor rotates the helix through one half of a revolution on each operation of the unit to cause a cam formed on the front of the helix to deliver an article over the front edge of the shelf so that articles are alternately delivered from one side of the separator and the other side thereof on successive operations of the unit.
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CROSS-REFERENCE TO RELATED APPLICATION
The present application is a divisional application of the U.S. application Ser. No. 10/507,231, filed on Sep. 9, 2004, entitled “STRETCH FABRIC WITH IMPROVED CHEMICAL RESISTANCE AND DURABILITY,” the teachings of which are incorporated by reference herein, as if reproduced in full hereinbelow now abandoned, which is a 371 National Stage of International Application No. PCT/US2003/007592, filed on Mar. 11, 2003, entitled “STRETCH FABRIC WITH IMPROVED CHEMICAL RESISTANCE AND DURABILITY,” the teachings of which are incorporated by reference herein, as if reproduced in full hereinbelow, and which claims priority from the U.S. Provisional Application No. 60/363,127, filed on Mar. 11, 2002, entitled “STRETCH FABRIC WITH IMPROVED CHEMICAL RESISTANCE AND DURABILITY,” the teachings of which are incorporated by reference herein, as if reproduced in full hereinbelow. U.S. Provisional Application No. 60/363,127 is a continuation-in-part of U.S. Ser. No. 09/627,534 filed on Jul. 28, 2000 now U.S. Pat. No. 6,437,014.
BACKGROUND OF THE INVENTION
The present invention relates to stretch fabrics. In one aspect, the invention relates to stretch fabrics comprising synthetic and natural fibers while in another aspect, the invention relates to such fabrics comprising crosslinked, heat-resistant elastic fibers capable of withstanding dyeing and heat-setting processes. The crosslinked, heat-resistant elastic fibers are useful in various durable or repeated-use fabric applications such as, but not limited to, clothing, undergarments, sports apparel and upholstery. The crosslinked, heat-resistant elastic fibers can be conveniently formed into fabrics using well-known techniques such as, for example, by using co-knitting techniques with cotton, nylon, and/or polyester fibers.
A material is typically characterized as elastic if it has a high percent elastic recovery (that is, a low percent permanent set) after application of a biasing force. Ideally, elastic materials are characterized by a combination of three important properties, i.e., (i) a low percent permanent set, (ii) a low stress or load at strain, and (iii) a low percent stress or load relaxation. In other words, there should be (i) a low stress or load requirement to stretch the material, (ii) no or low relaxing of the stress or unloading once the material is stretched, and (iii) complete or high recovery to original dimensions after the stretching, biasing or straining is discontinued.
To be used in the durable fabrics, the fibers making up the fabric have to be, inter alia, stable during dyeing and heat setting processes. For an elastic polyolefin fiber to be stable under dyeing and heat-setting conditions, it must be crosslinked. These fibers can be crosslinked by one or more of a number of different methods, e.g., e-beam or UV irradiation, silane or azide treatment, peroxide, etc., some methods better than others for fibers of a particular composition. For example, polyolefin fibers that are irradiated under an inert atmosphere (as opposed to irradiated under air) tend to be highly stable during dyeing processes (that is, the fibers do not melt or fuse together). The addition of a mixture of hindered phenol and hindered amine stabilizers further stabilized such fibers at heat setting conditions (200-2100 C).
Lycra®, a segmented polyurethane elastic material manufactured by E. I. du Pont de Nemours Company, is currently used in various durable stretch fabrics. Lycra, however, is not stable at the typical high heat-setting temperatures (200-210° C.) used for polyethylene terephthalate (PET) fiber. Moreover, and similar to ordinary uncrosslinked polyolefin-based elastic materials, Lycra fabrics tend to lose their integrity, shape and elastic properties when subjected to elevated service temperatures such as those encountered in washing, drying and ironing. As such, Lycra can not be easily used in co-knitting applications with high temperature fibers such as polyester fibers.
SUMMARY OF THE INVENTION
According to this invention, a stone-washed fabricated article comprises a fabric that comprises a heat-resistant, crosslinked olefin elastic fiber and an inelastic fiber. In one embodiment, the fabric is a durable stretch fabric made and processed from one or more crosslinked, heat-resistant olefin elastic fibers. The fabrics can be made by any process, e.g., weaving, knitting, etc., and from any combination of crosslinked, heat-resistant olefin elastic and inelastic (“hard”) fibers. These fabrics exhibit excellent chemical, e.g., chlorine, resistance and durability, e.g., they retain their shape and feel (“hand”) over repeated exposure to service conditions, e.g., washing, drying, etc. For example, in one embodiment the fabric has a change in elasticity not in excess of about 10% and/or retains at least about 50% of its growth after exposure to a 5% by weight permanganate solution for a period of at least 90 minutes at a temperature of at least 140 F. In another embodiment, the fabric retains at least about 10% of its elasticity and/or at least about 50% of its growth after exposure to a 10% by weight hypochlorite solution for a period of at least 90 minutes at a temperature of at least 140 F.
The crosslinked, heat-resistant olefin elastic fibers include ethylene polymers, propylene polymers and fully hydrogenated styrene block copolymers (also known as catalytically modified polymers). The ethylene polymers include the homogeneously branched and the substantially linear homogeneously branched ethylene polymers as well as ethylene-styrene interpolymers. The other fibers of the fabric can vary widely, and they include virtually all know natural and synthetic fibers, particularly inelastic fibers. Typical of these other fibers are cotton, wool, silk, nylon, polyester, and the like. Usually the crosslinked, heat-resistant olefin elastic fibers comprise a minority of the fabric on a weight basis.
The fabrics of this invention include (i) a stone-washed elastic cotton fabric, (ii) a dye-stripped elastic nylon fabric, (iii) a brilliant-colored, dyed elastic polyester (e.g., PET) fabric, (iv) a dry-cleaned elastic fabric (e.g., a fabric that has been exposed to perchloroethylene), and (v) a chlorine- or bromine-exposed elastic fabric comprising one or more of polyester, nylon and cotton. All of these fabrics have been exposed to harsh and stringent processes that utilize chemicals and conditions that would degrade most conventional stretch fabrics because these chemicals and conditions would degrade the stretch fiber component of these fabrics. The fabrics of this invention, however, comprise a stretch fiber that is particularly resistant to such degradation and as such, the fabric containing these fibers exhibits surprising durability and chemical resistance.
BRIEF DESCRIPTION OF THE FIGURES
The FIG. 1 is a photograph of four heavy weight, denim fabric samples comprising fiber made from AFFINITY ethylene/1-octene copolymer. Each sample was subjected to a different stone wash protocol, i.e., the first (or top) sample to a vintage wash, the second to an antique wash, the third to a destructive wash, and the fourth (or bottom) sample to a bleach-out wash. The stretch properties of each sample after the washing protocol were essentially the same as the stretch properties before the washing protocol. The dark blue patch on top of the first or top sample is the color of each sample before it was stone washed.
FIG. 2 is a Scanning Electron Microscopy (SEM) image of a Speedo swimsuit after a five-month wear test. The suit is of a tricot warp knit structure made with a chlorine-resistant Lycra™ fiber.
FIG. 3 is an SEM image of the swimsuit of FIG. 2 showing the loop structure under enhanced magnification.
FIG. 4 is a SEM image of a Speedo swimsuit after a four-month wear test. The suit is of a weft knit single jersey structure made with a crosslinked AFFINITY ethylene/1-octene copolymer fiber.
FIG. 5 is an SEM image of the swimsuit of FIG. 4 showing the loop structure under enhanced magnification.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
“Fiber” means a material in which the length to diameter ratio is greater than about 10. Fiber is typically classified according to its diameter. Filament fiber is generally defined as having an individual fiber diameter greater than about 15 denier, usually greater than about 30 denier. Fine denier fiber generally refers to a fiber having a diameter less than about 15 denier. Microdenier fiber is generally defined as fiber having a diameter less than about 100 microns denier.
“Filament fiber” or “monofilament fiber” means a single, continuous strand of material of indefinite (i.e., not predetermined) length, as opposed to a “staple fiber” which is a discontinuous strand of material of definite length (i.e., a strand which has been cut or otherwise divided into segments of a predetermined length).
The term “heat resistant” as used herein refers to the ability of an elastic polymer or elastic polymer composition in the form of fiber to pass the high temperature heat setting and dyeing tests described herein.
The term “elastic article” is used in reference to shaped items, while the term “elastic material” is a general reference to polymer, polymer blends, polymer compositions, articles, parts or items.
“Elastic” means that a fiber will recover at least about 50 percent of its stretched length after the first pull and after the fourth to 100% strain (doubled the length). Elasticity can also be described by the “permanent set” of the fiber. Permanent set is the converse of elasticity. A fiber is stretched to a certain point and subsequently released to the original position before stretch, and then stretched again. The point at which the fiber begins to pull a load is designated as the percent permanent set. “Elastic materials” are also referred to in the art as “elastomers” and “elastomeric”. Elastic material (sometimes referred to as an elastic article) includes the polyolefin polymer itself as well as, but not limited to, the polyolefin polymer in the form of a fiber, film, strip, tape, ribbon, sheet, coating, molding and the like. The preferred elastic material is fiber. The elastic material can be either cured or uncured, radiated or unradiated, and/or crosslinked or uncrosslinked. For heat reversibility, the elastic fiber must be substantially crosslinked or cured.
“Nonelastic material” means a material, e.g., a fiber, that is not elastic as defined above.
“Meltblown fibers” are fibers formed by extruding a molten thermoplastic polymer composition through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity gas streams (e.g. air) which function to attenuate the threads or filaments to reduced diameters. The filaments or threads are carried by the high velocity gas streams and deposited on a collecting surface to form a web of randomly dispersed fibers with average diameters generally smaller than 10 microns.
The term “spunbond” is used herein in the conventional sense to refer to fibers formed by extruding the molten elastic polymer or elastic polymer composition as filaments through a plurality of fine, usually circular, die capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced and thereafter depositing the filaments onto a collecting surface to form a web of randomly dispersed spunbond fibers with average diameters generally between 7 and 30 microns.
The term “nonwoven” as used herein and in the conventional sense means a web or fabric having a structure of individual fibers or threads which are randomly interlaid, but not in an identifiable manner as is the case for a knitted fabric. The elastic fiber of the present invention can be employed to prepare inventive nonwoven elastic fabrics as well as composite structures comprising the elastic nonwoven fabric in combination with nonelastic materials.
The term “conjugated” refers to fibers which have been formed from at least two polymers extruded from separate extruders but meltblown or spun together to form one fiber. Conjugated fibers are sometimes referred to in the art as multicomponent or bicomponent fibers. The polymers are usually different from each other although conjugated fibers may be monocomponent fibers. The polymers are arranged in substantially constantly positioned distinct zones across the cross-section of the conjugated fibers and extend continuously along the length of the conjugated fibers. The configuration of conjugated fibers can be, for example, a sheath/core arrangement (wherein one polymer is surrounded by another), a side by side arrangement, a pie arrangement or an “islands-in-the sea” arrangement. Conjugated fibers are described in U.S. Pat. Nos. 5,108,820, 5,336,552 and 5,382,400. The elastic fiber of the present invention can be in a conjugated configuration, for example, as a core or sheath, or both.
The term “thermal bonding” is used herein refers to the heating of fibers to effect the melting (or softening) and fusing of fibers such that a nonwoven fabric is produced. Thermal bonding includes calendar bonding and through-air bonding as well as methods known in the art. The expression “thermal bondable at a reduced hot melt adhesive amount” refers to comparative peel test results using Ato Findley Adhesive HX9275 (supplied by Ato Findley Nederlands B. V., Roosendaal, The Netherlands) or H. B. Fuller Adhesive D875BD1 (supplied by H. B. Fuller GmbH, IOneburg, Germany) and test procedures and methods described in WO 00/00229, wherein the same peel strength as the adhesive without deploying thermal bonding can be obtained even though the quantity of adhesive is at least 15 percent less where thermal bonding is deployed.
The term “polymer”, as used herein, refers to a polymeric compound prepared by polymerizing one or more monomers. As used herein, generic term “polymer” embraces the terms “homopolymer,” “copolymer,” “terpolymer” as well as “interpolymer.” A polymer is usually made in one reactor or polymerization vessel but can as well as be made using multiple reactors or polymerization vessels, although the latter is usually referred to as a polymer composition.
The term “polymer composition” as used herein refers to a mixture of a polymer and at least one ingredient added to or mixed with the polymer after the polymer is formed. Thus, the term “polymer composition” includes poly-blends (that is, admixtures of two or more polymers wherein each polymers is made in separate reactors or polymerization whether or not the reactors or vessels are part of the same polymerization system or not).
The term “interpolymer”, as used herein refers to polymers prepared by the polymerization of at least two different types of monomers. As used herein the generic term “interpolymer” includes the term “copolymers” (which is usually employed to refer to polymers prepared from two different monomers) as well as the term “terpolymers” (which is usually employed to refer to polymers prepared from three different types of monomers).
“Radiated” or “irradiated” means that the elastic polymer or polymer composition or the shaped article comprised of the elastic polymer or elastic composition was subjected to at least 3 megarads (or the equivalent of 3 megarads) of radiation dosage whether or not it resulted in a measured decrease in percent xylene extractables (i.e., an increase in insoluble gel). Preferably, substantial crosslinking results from the irradiation. “Radiated” or “irradiated” may also refer to the use of UV-radiation at an appropriate dose level along with optional photoinitiators and photocrosslinkers to induce crosslinking.
The terms “crosslinked” and “substantially crosslinked” as used herein mean the elastic polymer or elastic polymer composition or the shaped article comprised of the elastic polymer or elastic polymer composition is characterized as having xylene extractables of less than or equal to 70 weight percent (that, is, greater than or equal to 30 weight percent gel content), preferably less than or equal to 40 weight percent (that is, greater than or equal to 60 weight percent gel content), more preferably less than or equal to 35 weight percent (that is; greater than or equal to 65 weight percent gel content), where xylene extractables (and gel content) are determined in accordance with ASTM D-2765.
The terms “cured” and “substantially cured” as used herein means the elastic polymer or elastic polymer composition or the shaped article comprised of the elastic polymer or elastic polymer composition was subjected or exposed to a treatment which induced crosslinking. As used herein, the terms also relate to the use of a grafted silane compound, e-beam and UV-radiation.
The terms “curable” and “crosslinkable” as used herein mean the elastic polymer or elastic polymer composition or the shaped article comprised of the elastic polymer or elastic polymer composition is not crosslinked and has not been subjected or exposed to treatment which induces crosslinking although the elastic polymer, elastic polymer composition or the shaped article comprised of the elastic polymer or elastic polymer composition comprises additive(s) or functionality that will effectuate crosslinking upon subjected or exposed to such treatment.
The term “pro-rad additive” as used herein means a compound which is not activated during normal fabrication or processing of the elastic polymer or elastic polymer composition, but can be activated by the application of temperatures (heat) substantially above normal fabrication or processing temperatures or ionizing energy (or both) (and especially with regard to article, part or item fabrication and processing) to effectuate some measurable gelation or preferably, substantial crosslinking.
In the practice of the present invention, curing, irradiation or crosslinking of the elastic polymers, elastic polymer compositions or articles comprising elastic polymers or elastic polymer compositions can be accomplished by any means known in the art, including, but not limited to, electron-beam irradiation, beta irradiation, X-rays, UV-radiation, controlled thermal heating, corona irradiation, peroxides, allyl compounds and gamma-radiation with or without crosslinking catalyst. Electron-beam and UV-radiation irradiation are the preferred technique for crosslinking the olefin polymer.
Preferably, the curing, irradiation, crosslinking or combination thereof provides a percent gel, as determined using xylene in accordance with ASTM D-2765, of greater than or equal to 30 weight percent, more preferably greater than or equal to 55 weight percent, most preferably greater than or equal to 60 weight percent. Suitable electron-beam irradiation equipment is available from Energy Services, Inc. Wilmington, Mass. with capabilities of at least 100 kilo-electron volts (KeV) and at least 5 kilowatts (Kw). Preferably, electrons are employed up to 70 megarads dosages. The irradiation source can be any electron beam generator operating in a range of 150 Kev to 12 mega-electron volts (MeV) with a power output capable of supplying the desired dosage. The electron voltage can be adjusted to appropriate levels which may be, for example, 100,000, 300,000, 1,000,000 or 2,000,000 or 3,000,000 or 6,000,000, or higher or lower. Many other apparati for irradiating polymeric materials are known in the art.
In the present invention, effective irradiation is usually carried out at a dosage between 3 megarads (Mrad) to megarads, preferably from 10 to 35 megarads, more preferably from 15 to 32 megarads, and most preferably from 19 to 28 megarads. Further, the irradiation can be conveniently carried out at room temperature. Preferably, irradiation is conducted while the article (or plurality of articles) is at lower temperatures throughout the exposure, such as, for example, at −50° C. to 40° C., especially at −20° C. to 30° C., more especially at 0° C. to 25° C., and most especially from 0° C. to 12° C. The irradiation can be carried out on-line (that is, during fabrication of the article), off-line (such as after fabrication of the article, for example, film, by unwinding or wrapping the fabricated article) or on-spool (as such in the case of fibers, and filaments). Preferably, the irradiation is carried out after shaping or fabrication of the article. Also, in a preferred embodiment, a pro-rad additive is incorporated into the elastic polymer or elastic polymer composition and the polymer or composition is subsequently irradiated with electron beam radiation at 8 to 32 megarads.
In another aspect of the invention, the irradiation is carried out under an inert or oxygen-limited atmosphere. Suitable atmospheres can be provided by the use of helium, argon, nitrogen, carbon dioxide, xenon and/or a vacuum. Substantial improvements in high temperature serviceability can be gained by using an inert or oxygen-limited atmosphere without any attendant substantial lost in elastic performance ordinarily associated with service or use at elevated temperatures.
Crosslinking can be promoted with a crosslinking catalyst, and any catalyst that will provide this function can be used. Suitable catalysts generally include organic bases, carboxylic acids, and organometallic compounds including organic titanates and complexes or carboxylates of lead, cobalt, iron, nickel, zinc and tin. Dibutyltindilaurate, dioctyltinmaleate, dibutyltindiacetate, dibutyltindioctoate, stannous acetate, stannous octoate, lead naphthenate, zinc caprylate, and cobalt naphthenate. Tin carboxylate, especially dibutyltindilaurate and dioctyltinmaleate, are particularly effective for this invention. The catalyst (or mixture of catalysts) is present in a catalytic amount, typically between 0.015 and 0.035 phr.
Representative pro-rad additives include, but are not limited to, azo compounds, organic peroxides and polyfunctional vinyl or allyl compounds such as, for example, triallyl cyanurate, triallyl isocyanurate, pentaerthritol tetramethacrylate, glutaraldehyde, ethylene glycol dimethacrylate, diallyl maleate, dipropargyl maleate, dipropargyl monoallyl cyanurate, dicumyl peroxide, di-tert-butyl peroxide, t-butyl perbenzoate, benzoyl peroxide, cumene hydroperoxide, t-butyl peroctoate, methyl ethyl ketone peroxide, 2,5-dimethyl-2,5-di(t-butyl peroxy)hexane, lauryl peroxide, tert-butyl peracetate, and azobisisobutyl nitrite and combination thereof. Preferred pro-rad additives for use in the present invention are compounds which have polyfunctional (that is, at least two) moieties such as C═C, C═N or C═O.
At least one pro-rad additive can be introduced to the ethylene interpolymer by any method known in the art. However, preferably the pro-rad additives) is introduced via a masterbatch concentrate comprising the same or different base resin as the ethylene interpolymer. Preferably, the pro-rad additive concentration for the masterbatch is relatively high for example, greater than or equal to 25 weight percent (based on the total weight of the concentrate).
The at least one pro-rad additive is introduced to the ethylene polymer in any effective amount. Preferably, the at least one pro-rad additive introduction amount is from 0.001 20 to 5 weight percent, more preferably from 0.005 to 2.5 weight percent and most preferably from 0.015 to 1 weight percent (based on the total weight of the substantially hydrogenated block polymer).
Suitable amine or nitrogen-containing stabilizers for use in the present invention include, but are not limited to, naphthylamines, for example, N-phenyl naphthylamines such as Naugard PAN supplied by Uniroyal); diphenylamine and derivatives thereof which are also referred to as secondary aromatic amines (for example, 4,4′-bis (oc, oc-dimethylbenzyl) diphenylamine which is supplied by Uniroyal Chemical under the designation Naugard® 445); p-phenylenediamines (for example, Wingstay 300 supplied by Goodyear); piperidines and derivatives thereof (for example, poly[[6-[(1,1,3,3-tetramethylbutyl)amino]-1,3,5-triazine-2, 4-diyl][(2,2,6,6-tetramethyl-4-piperidinyl)imino)-1, 6-hexanediyl[(2,2,6,6-tetramethyl-4-piperidinyl)imino)]) which is supplied by Ciba Specialty Chemicals under the designation of Chimassorbe 944 as well as other substituted piperidines such as Chimassorb® 119, Tinuviri 622 and Tinuvin® 770, all three also supplied by Ciba Specialty Chemicals), and quinolines (for example, oxyquinolines and hydroquinolines such as polymeric 2,2,4-trimethyl-1,2-dihydroquinoline which is supplied by Vanderbilt Company under the designation Agerite® D).
Suitable amine or nitrogen-containing stabilizers also include the hybrid stabilizers such as aminophenols (for example, N,N′-hexamethylenebis-3-(3,5-di-tert-butyl-4-hydroxyphenyl)-propionamide), acylaminophenols (which are also referred to as 4-hydroyanilides) and the various hybrid stabilizers described in U.S. Pat. No. 5,122,593 that consist of a N-(substituted)-1-(piperazine-2-one alkyl) group at one end and a (3,5-dialkyl-4-hydroxyphenyl)-α,α-disubstituted acetamine at the other end.
Other suitable amine or nitrogen-containing stabilizers include carboxylic acid amides of aromatic mono and dicarboxylic acids and N-monosubstituted derivatives (e.g. N,N′-diphenylokamide and 2,2′-oxamidobisethyl-3-(3,5-di-tertbutyl-4-hydroxyphenyl)propionate which is supplied by Uniroyal Chemical under the designation Naugarde XL-1); hydrazides of aliphatic and aromatic mono- and dicarboxylic acids and N-acylated derivatives thereof; bis-acylated hydrazine derivatives; melamine; benzotriazoles, hydrazones; acylated derivatives of hydrazino-triazines; polyhydrazides; salicylaethylenediimines; salicylaloximes; derivatives of ethylenediamino tetraacetic acid; and aminotriazoles and acylated derivatives thereof.
Preferred amine or nitrogen-containing stabilizers for use in the present invention are diphenylamines, substituted piperidines and hydroquinolines. The most preferred amine or nitrogen-containing stabilizers are hindered amines since they tend to cause less detrimental polymer discoloration than aromatic amines.
Further, the at least one amine or nitrogen-containing stabilizer can be employed alone or in combination with one or more other stabilizer such as, for example, but not limited to, other amine or nitrogen-containing stabilizer; a hindered phenol (for example, 2,6-di-tert-butyl-4-methylphenol which is supplied by Koppers Chemical under the designation BHT; tetrakis(methylene 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) methane which is supplied by Ciba Specialty Chemicals under the designation Irganox 1010; Irganox 1076 supplied by Ciba Specialty Chemicals; Cyanox 1790 which is tris (4-t-butyl-3-hydroxy=2,6-dimethylbenzyl)-s-triazine-2,4,6-(1H,3H,5H)-trione as supplied by Cytec; and Irganox 3114 which is 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazinane-2,4,6-trione as supplied by Ciba Specialty Chemicals); a thioester (for example, dilauryl thiodipropionate which is supplied by Evans under the designation Evanstab® 12); a phosphite (for example, Irgafos® 168 supplied by Ciba Specialty Chemicals and tri(nonylphenyl) phosphite which is supplied by Uniroyal Chemical under the designation Naugard® P); diphosphite (for example, distearyl pentaerthritol diphosphite which is supplied by Borg-Warner under the designation Westori 618); a. polymeric phosphite (for example, Wytox .345-S(1) supplied by Olin); phosphited phenol and bisphenol (for example, WytoX 604 supplied by Olin); and diphosphonite (for example, tetrakis(2,4-di-tert-butylphenyl) 4,4′-biphenylylene diphosphonite which is supplied by Sandos under the designation Sandostab® P-EPQ). A preferred combination is a hindered amine and a hindered phenol. With regard to hindered phenols, Cyanox 1790 and Irganox 3114 are preferred since these stabilizers tend to have a less detrimental effect on discoloration (due to nitroxide gas formation) than Irganox 1076 or Irganox 1010.
Preferably, the at least one amine or nitrogen-containing stabilizer (and optional other stabilizer) is added to the homogeneously branched ethylene polymer or the substantially hydrogenated block polymer or both in a melt compounding step, more preferably by the use of an additive concentrate, prior to fabrication and shaping process steps. The at least one nitrogen-containing stabilizer (and the optional other stabilizer) can be added to the interpolymer or block polymer at any effective concentration. But, preferably, the total stabilizer concentration is in the range of from 0.02 to 2 weight percent (based on the total weight of the stabilizer and interpolymer and/or block polymer), more preferably in the range from 0.075 to 1 weight percent (based on the total weight of the stabilizer and the interpolymer and/or block polymer) and most preferably in the range of from 0.1 to 0.32 weight percent (based on the total weight of the stabilizer and the interpolymer and/or block). Where an optional other stabilizer is used (for example, a hindered phenol), the concentration of the amine to the phenol is in-the range from 2:1 to 1:2, preferably in the range of from 1.25:1 to 1:1.25.
An especially preferred embodiment is a combination of amine with a phenol and a phosphorus-containing stabilizer, more preferably where the total concentration of the phenol and a phosphorus-containing stabilizer is less than or equal to 0.15 weight percent and the amine or nitrogen-containing stabilizer concentration is in the range of 0.15 to 0.32 weight percent.
In-process additives, for example, calcium stearate, water, and fluoropolymers, may-also be used for purposes such as for the deactivation of residual catalyst or improved processability or both. Colorants, coupling agents and fire retardants may also be include as longer as their incorporation does not disturb the desirable characteristics of the invention.
Suitable polymers for use in the present invention include ethylene-α-olefin interpolymers, substantially hydrogenated block polymers, styrene butadiene styrene block polymers, styrene-ethylenelbutene-styrene block polymers, ethylene styrene interpolymers, polypropylenes, polyamides, polyurethanes and any combination thereof. The preferred polymers are homogeneously branched ethylene-α olefin interpolymers.
The term “substantially hydrogenated block polymer” as used herein means a block copolymer that is characterized as having a hydrogenation level of greater than 90 percent (by number) for each vinyl aromatic monomer unit block and a hydrogenation level of greater than 95 percent (by number) for each conjugated diene polymer block, where for both the vinyl aromatic monomer and conjugated diene monomer repeating unit blocks, hydrogenation converts unsaturated moieties into saturated moieties. These polymers are more fully described in U.S. Ser. No. 09/627,534 filed on Jul. 28, 2000.
The term “partially hydrogenated block polymer” as used herein means a block polymer that is hydrogenated but does not meet the hydrogenation levels that define a substantially hydrogenated block polymer.
Substantially hydrogenated block copolymers comprise at least one distinct block of a hydrogenated polymerized vinyl aromatic monomer and at least one block of a hydrogenated polymerized conjugated diene monomer. Preferred substantially hydrogenated block polymers are triblock comprising (before hydrogenation) two vinyl aromatic monomer unit blocks and one conjugated diene monomer unit block. Suitable substantially hydrogenated block polymers for use in the present invention are generally characterized by:
a) a weight ratio of conjugated diene monomer unit block to vinyl aromatic monomer unit block before hydrogenation of greater than 60:40
b) a weight average molecular weight (MW) before hydrogenation of from 30,000 to 150,000 (preferably, especially for high drawdown application such as, for example, fiber spinning, less than or equal to 81,000), wherein each vinyl aromatic monomer unit block (A) has a weight average molecular weight, Mwa, of from 5,000 to 45,000 and each conjugated diene monomer unit block (B) has a weight average molecular weight, Mwb, of from 12,000 to 110,000; and
c) a hydrogenation level such that each vinyl aromatic monomer unit block is hydrogenated to a level of greater than 90 percent and each conjugated diene monomer unit block is hydrogenated to a level of greater than 95 percent, as determined using UV-VIS spectrophotometry and proton NMR analysis.
Neat substantially hydrogenated block polymers can be further characterized as having a viscosity at 0.1 rad/sec and 190° C., as determined using a parallel plate rheometer (Rheometrics RMS-800 equipped with 25 mm diameter flat plates at 1.5 mm gap under a nitrogen purge), that is less than 1,000,000 poises, preferably less than or equal to 750,000 poises, more preferably less than 500,000 poises or that is at least 30 percent, preferably at least 50 percent, more preferably at least 80 lower than that of a partially hydrogenated block polymer having the same monomer types, number of monomer units, symmetry and weight average molecular weight, or that is defined by the following inequality:
Ln viscosity at 0.1 rad/sec #(7.08×10−5)( MW )+7.89
where “Ln” means natural log, and “#” means less than or equal to.
Neat substantially hydrogenated block polymers can also be further characterized as having a drawability of less than or equal to 200 denier, preferably less than or equal to 175 denier, more preferably less than or equal to 50 denier when fiber spun at 0.43 g/minute and 250° C. using an Instron capillary rheometer equipped with a die having a 1,000 micron diameter and a 20:1 L/D. The term “neat” is used herein to mean unblended with other synthetic polymer.
The vinyl aromatic monomer is typically a monomer of the formula:
wherein R′ is hydrogen or alkyl, Ar is phenyl, halophenyl, alkylphenyl, alkylhalophenyl, naphthyl, pyridinyl, or anthracenyl, wherein any alkyl group contains 1 to 6 carbon atoms which may be mono or multisubstituted with functional groups such as halo, nitro, amino, hydroxy, cyano, carbonyl and carboxyl. More preferably Ar is phenyl or alkyl phenyl with phenyl being most preferred. Typical vinyl aromatic monomers include styrene, alpha-methylstyrene, all isomers of vinyl toluene, especially para-vinyl toluene, all isomers of ethyl styrene, propyl styrene, butyl styrene, vinyl biphenyl, vinyl naphthalene, vinyl anthracene and mixtures thereof. The block copolymer can contain more than one specific polymerized vinyl aromatic monomer. In other words, the block copolymer can contain a polystyrene block and a poly-α-methylstyrene block. The hydrogenated vinyl aromatic block may also be a copolymer, wherein the hydrogenated vinyl aromatic portion is at least 50 weight percent of the copolymer.
The conjugated diene monomer can be any monomer having 2 conjugated double bonds. Such monomers include for example 1,3-butadiene, 2-methyl-1,3-butadiene, 2-methyl-1,3-pentadiene, isoprene and similar compounds, and mixtures thereof. The block copolymer can contain more than one specific polymerized conjugated diene monomer. In other words, the block copolymer can contain a polybutadiene block and a polyisoprene block.
The conjugated diene polymer block can comprise materials that remain amorphous after the hydrogenation process, or materials which are capable of crystallization after hydrogenation. Hydrogenated polyisoprene blocks remain amorphous, while hydrogenated polybutadiene blocks can be either amorphous or crystallizable depending upon their structure. Polybutadiene can contain either a 1,2 configuration, which hydrogenates to give the equivalent of a 1-butene repeat unit, or a 1,4-configuration, which hydrogenates to give the equivalent of an ethylene repeat unit. Polybutadiene blocks having at least approximately 40 weight percent 1,2-butadiene content, based on the weight of the polybutadiene block, provides substantially amorphous blocks with low glass transition temperatures upon hydrogenation. Polybutadiene blocks having less than approximately 40 weight percent 1,2-butadiene content, based on the weight of the polybutadiene block, provide crystalline blocks upon hydrogenation. Depending on the final application of the polymer it may be desirable to incorporate a crystalline block (to improve solvent resistance) or an amorphous, more compliant block. In some applications, the block copolymer can contain more than one conjugated diene polymer block, such as a polybutadiene block and a polyisoprene block. The conjugated diene polymer block may also be a copolymer of a conjugated diene, wherein the conjugated diene portion of the copolymer is at least 50 weight percent of the copolymer. The conjugated diene polymer block may also be a copolymer of more than one conjugated diene, such as a copolymer of butadiene and isoprene. Also, other polymeric blocks may also be included in the substantially hydrogenated block polymers used in the present invention.
A “block” is herein defined as a polymeric segment of a copolymer which exhibits microphase separation from a structurally or compositionally different polymeric segment of the copolymer. Microphase separation occurs due to the incompatibility of the polymeric segments within the block copolymer. The separation of block segments can be detected by the presence of distinct glass transition temperatures. Microphase separation and block copolymers are generally discussed in “Block Copolymers-Designer Soft Materials”, PHYSICS TODAY, February, 1999, pages 32-38. Suitable substantially hydrogenated block polymers typically have a weight ratio of conjugated diene monomer unit block to vinyl aromatic monomer unit block before hydrogenation of from 60:40 to 95:5, preferably from 65:35 to 90:10, more preferably from 70:30 to 85:15, based on the total weight of the conjugated diene monomer unit and vinyl aromatic monomer unit blocks.
The total weights of the vinyl aromatic monomer unit block(s) and the conjugated diene monomer unit block(s) before hydrogenation is typically at least 80 weight percent, preferably at least 90, and more preferably at least 95 weight percent of the total weight of the hydrogenated block polymer. More specifically, the hydrogenated block polymer typically contains from 1 to 99 weight percent of a hydrogenated vinyl aromatic polymer (for example, polyvinylcyclohexane or PVCH block, generally from 10, preferably from 15, more preferably from 20, even more preferably from 25, and most preferably from 30 to 90 weight percent, preferably to 85 and most preferably to 80 percent, based on the total weight of the hydrogenated block polymer. And, as to the conjugated diene polymer block, the hydrogenated block copolymer typically contains from 1 to 99 weight percent of a hydrogenated conjugated diene polymer block, preferably from 10, more preferably from 15, and most preferably from 20 to 90 weight percent, typically to 85, preferably to 80, more preferably to 75, even more preferably to 70 and most preferably to 65 percent, based on the total weight of the copolymer.
The substantially hydrogenated block polymers suitable for use in the present invention are produced by the hydrogenation of block copolymers including triblock, multiblock, tapered block, and star block polymers such as, for example, but not limited to, SBS, SBSBS, SIS, SISIS, and SISBS (wherein S is polystyrene, B is polybutadiene and I is polyisoprene). Preferred block polymers contain at least one block segment comprised of a vinyl aromatic polymer block, more preferably the block polymer is symmetrical such as, for example, a triblock with a vinyl aromatic polymer block on each end. The block polymers may, however, contain any number of additional blocks, wherein these blocks may be attached at any point to the triblock polymer backbone. Thus, linear blocks would include, for example, SBS, SBSB, SBSBS, and SBSBSB. That is, suitable block polymers include asymmetrical block polymers and tapered linear block polymers. The block polymer can also be branched, wherein polymer chains are attached at any point along the polymer backbone. In addition, blends of any of the aforementioned block copolymers can also be used as well as blends of the block copolymers with their hydrogenated homopolymer counterparts. In other words, a hydrogenated SBS block polymer can be blended with a hydrogenated SBSBS block polymer or a hydrogenated polystyrene homopolymer or both. It should be noted here that in the production of triblock polymers, small amounts of residual diblock copolymers are often produced.
The weight average molecular weight (MW) of suitable substantially hydrogenated block polymers, as measured before hydrogenation, is generally from 30,000, preferably from 45,000, more preferably from 55,000 and most preferably from 60,000 to 150,000, typically to 140,000, generally to 135,000, preferably to 130,000, more preferably to 125,000, and most preferably to 120,000. But preferably, especially when used neat (that is, without being blended with other polymer) for fiber melt spinning purposes, the weight average molecular weight before hydrogenation will be less than or 20 equal to 81,500, more preferably less than or equal to 75,000 and most preferably less than or equal to 67,500. Substantially hydrogenated block polymers can have vinyl aromatic monomer unit block with weight average molecular weights, Mw, before hydrogenation of from 6,000, especially from 9,000, more-especially from 11,000, and most especially from 12,000 to 45,000, especially to 35,000, more especially to 25,000 and most especially to 20,000. The weight average molecular weight of the conjugated diene monomer unit block before hydrogenation can be from 12,000, especially from 27,000, more especially from 33,000 and most especially from 36,000 to 110,000, especially to 100,000, more especially to 90,000 and most especially to 80,000. But preferably, especially when used neat for fiber melt spinning purposes, for triblocks comprising two hydrogenated vinyl aromatic monomer unit blocks and one hydrogenated conjugated diene monomer unit block, the weight average molecular weight of each vinyl aromatic monomer unit block before hydrogenation will be less than or equal to 15,000, more preferably less than or equal to 13,000 and most preferably less than or equal to 12,000.
It is important to note that each individual block of the hydrogenated block copolymer of the present invention, can have its own distinct molecular weight. In other words, for example, two vinyl aromatic polymer blocks may each have a different molecular weight. Mp and MW, as used to throughout the specification, are determined using gel permeation chromatography (GPC). The molecular weight of the substantially hydrogenated block polymer and properties obtained are dependent upon the molecular weight of each of the monomer unit blocks. For substantially hydrogenated block polymers, molecular weights are determined by comparison to narrow polydispersity homopolymer standards corresponding to the different monomer unit segments (for example, polystyrene and polybutadiene standards are used for SBS block copolymers) with adjustments based on the composition of the block copolymer. Also for example, for a triblock copolymer composed of styrene (S) and butadiene (B), the copolymer molecular weight can be obtained by the following equation:
InMc=x ln Ma+ (1 −x ) InMb
where Mc is the molecular weight of the copolymer, x is the weight fraction of S in the copolymer, Ma is the apparent molecular based on the calibration for S homopolymer and Mb is the apparent molecular weight based on the calibration for homopolymer B. This method is described in detail by L. H. Tung, Journal of Applied Polymer Science, volume 24, 953, 1979.
Methods of making block polymers are well known in the art. Typically, block polymers are made by anionic polymerization, examples of which are cited in Anionic Polymerization Principles and Practical Applications, H. L. Hsieh and R. P. Quirk, Marcel Dekker, New York, 1996. Block polymers can be made by sequential monomer addition to a carbanionic initiator such as sec-butyl lithium or n-butyl lithium. Block polymers can also be made by coupling a triblock material with a divalent coupling agent such as 1,2-dibromoethane, dichlorodimethylsilane, or phenylbenzoate. In this method, a small chain (less than 10 monomer repeat units) of a conjugated diene monomer can be reacted with the vinyl aromatic monomer unit coupling end to facilitate the coupling reaction. Note, however, vinyl aromatic polymer blocks are typically difficult to couple, therefore, this technique is commonly used to achieve coupling of the vinyl aromatic polymer ends. The small chain of the conjugated diene monomer unit does not constitute a distinct block since no microphase separation is achieved.
Coupling reagents and strategies which have been demonstrated for a variety of anionic polymerizations are discussed in Hsieh and Quirk, Chapter 12, pgs. 307-331. In another method, a difunctional anionic initiator is used to initiate the polymerization from the center of the block system, wherein subsequent monomer additions add equally to both ends of the growing polymer chain. An example of a such a difunctional initiator is 1,3-bis(1-phenylethenyl) benzene treated with organolithium compounds, as described in U.S. Pat. Nos. 4,200,718 and 4,196,154.
After preparation of the block polymer, the polymer is hydrogenated to remove sites of unsaturation in both the conjugated diene monomer unit block(s) and the vinyl aromatic monomer unit block(s) of the polymer. Any method of hydrogenation can be used where suitable methods typically include the use of metal catalysts supported on an inorganic substrate, such as Pd on BaSO 4 (U.S. Pat. No. 5,352,744) and Ni on kieselguhr (U.S. Pat. No. 3,333,024). Additionally, soluble, homogeneous catalysts such those prepared from combinations of transition metal salts of 2-ethylhexanoic acid and alkyl lithiums can be used to fully saturate block copolymers, as described in Die Makromolekulare Chemie, Volume 160, pp. 291, 1972. Hydrogenation can also be achieved using hydrogen and a heterogeneous catalyst such as those described in U.S. Pat. Nos. 5,352,744; 5,612,422 and 5,645,253. The catalysts described therein are heterogeneous catalysts consisting of a metal crystallite supported on a porous silica substrate. An example of a silica supported catalyst which is especially useful in the polymer hydrogenation is a silica which has a surface area of at least 10 m 2 /g which is synthesized such that it contains pores with diameters ranging between 3000 and 6000 angstroms. This silica is then impregnated with a metal capable of catalyzing hydrogenation of the polymer, such as nickel, cobalt, rhodium, ruthenium, palladium, platinum, other Group VIII metals, combinations or alloys thereof. Other heterogeneous catalysts can also be used, having average pore diameters in the range of 500 to 3,000 angstroms.
The level of hydrogenation of the substantially hydrogenated block polymers used in the present invention is greater than 95 percent for the conjugated diene monomer unit block(s) and greater than 90 percent for the vinyl aromatic monomer unit block(s), preferably greater than 99 percent for the conjugated diene monomer unit block(s) and greater than 95 percent for the vinyl aromatic monomer unit block(s), more preferably greater than 99.5 percent for the conjugated diene monomer unit block(s) and greater than 98 percent for the vinyl aromatic monomer unit block(s), and most preferably greater than 99.9 percent for the conjugated diene monomer unit block(s) and 99.5 percent for the vinyl aromatic monomer unit block(s).
The term “level of hydrogenation” refers to the percentage of the original unsaturated bonds that become saturated upon hydrogenation. The level of hydrogenation for the (hydrogenated) vinyl aromatic monomer unit block(s) can be determined using gamma-VIS spectrophotometry, while the level of hydrogenation for the (hydrogenated) diene conjugated monomer unit block(s) can be determined using proton NMR. The block polymer composition (that is, ratio of conjugated diene monomer unit blocks to vinyl aromatic monomer unit blocks) can be determined using proton NMR and a comparative integration technique such as that described by Santee, Chang and Morton in Journal of Polymer Science: Polymer Letter Edition, Vol. 11, page 449 (1973). Conveniently, a Varian Inova NMR unit set at 300 MHz for 1 H is used and samples of the block polymer are analyzed as 4 percent solutions (w/v) in CDC13 (deuterochloroform). Individual block lengths can be calculated from the weight average molecular weight, Mw, and 1 H NMR compositional analysis and by assuming a symmetrical structure (for example, a triblock with terminal polystyrene blocks).
The term “homogeneously branched ethylene polymer” is used herein in the conventional sense to refer to an ethylene interpolymer in which the comonomer is randomly distributed within a given polymer molecule and wherein substantially all of the polymer molecules have the same ethylene to comonomer molar ratio. The term refers to an ethylene interpolymer that are manufactured using so-called homogeneous or single-site catalyst systems known in the art such Ziegler vanadium, hafnium and zirconium catalyst systems and metallocene catalyst systems for example, a constrained geometry catalyst systems which is further described herein below.
Homogeneously branched ethylene polymers for use in the present invention can be also described as having less than 15 weight percent, preferably less 10 weight percent, more preferably less than 5 and most preferably zero (0) weight percent of the polymer with a degree of short chain branching less than or equal to 10 methyls/1000 carbons. That is, the polymer contains no measurable high density polymer fraction (for example, there is no fraction having a density of equal to or greater than 0.94 g/cm3), as determined, for example, using a temperature rising elution fractionation (TREF) technique and infrared or 13 C nuclear magnetic resonance (NMR) analysis.
Preferably, the homogeneously branched ethylene polymer is characterized as having a narrow, essentially single melting TREF profile/curve and essentially lacking a measurable high density polymer portion, as determined using a temperature rising elution fractionation technique (abbreviated herein as “TREF”). The composition distribution of an ethylene interpolymer can be readily determined from TREE as described, for example, by Wild et al., Journal of Polymer Science, Poly. Phys. Ed., Vol. 20, p. 441 (1982), or in U.S. Pat. Nos. 4,798,081 and 5,008,204; or by L. D. Cady, “The Role of Comonomer Type and Distribution in LLDPE Product Performance,” SPE Regional Technical Conference, Quaker Square Hilton, Akron, Ohio, October 1-2, pp. 107-119 (1985).
The composition (monomer) distribution of the interpolymer can also be determined using 13 C NMR analysis in accordance with techniques described in U.S. Pat. No. 5,292,845; U.S. Pat. No. 4,798,081; U.S. Pat. No. 5,089,321 and by J. C. Randall, Rev. Macromol. Chem. Phys., C29, pp. 201-317 (1989). In analytical temperature rising elution fractionation analysis (as described in U.S. Pat. No. 4,798,081 and abbreviated herein as “ATREF”), the polymer, polymer composition or article to be analyzed is dissolved in a suitable hot solvent (for example, trichlorobenzene) and allowed to crystallized in a column containing an inert support (stainless steel shot) by slowly reducing the temperature. The column is equipped with both a refractive index detector and a differential viscometer (DV) detector. An ATREF-DV chromatogram curve is then generated by eluting the crystallized polymer sample from the column by slowly increasing the temperature of the eluting solvent (trichlorobenzene). The ATREF curve is also frequently called the short chain branching distribution (SCBD) or composition distribution (CD) curve, since it indicates how evenly the comonomer (for example, 1-octene) is distributed throughout the sample in that as elution temperature decreases, comonomer content increases. The refractive index detector provides the short chain distribution information and the differential viscometer detector provides an estimate of the viscosity average molecular weight. The composition distribution and other compositional information can also be determined using crystallization analysis fractionation such as the CRYSTAF fractionalysis package available commercially from PolymerChar, Valencia, Spain.
Preferred homogeneously branched ethylene polymers (such as, but not limited to, substantially linear ethylene polymers) have a single melting peak between −30 and 150° C., as determined using differential scanning calorimetry (DSC), as opposed to traditional Ziegler polymerized heterogeneously branched ethylene polymers (for example, LLDPE and ULDPE or VLDPE) which have two or more melting points. The single melting peak is determined using a differential scanning calorimeter standardized with indium and deionized water. The method involves about 5-7 mg sample sizes, a “first heat” to about 180° C. which is held for 4 minutes, a cool down at 10° C./min. to −30° C. which is held for 3 minutes, and heat up at 10° C./min. to 150° C. to provide a “second heat” heat flow vs. temperature curve from which the melting peak(s) is obtained. Total heat of fusion of the polymer is calculated from the area under the curve.
The at least one homogeneously branched ethylene interpolymer to be irradiated and/or crosslinked has a density at 23° C. less than 0.90 g/cm 3 , preferably less than or equal to 0.88 g/cm 3 , more preferably less than or equal to 0.87 g/cm 3 , and especially in the range of 0.86 g/cm 3 to 0.875 g/cm 3 , as measured in accordance with ASTM D792. Preferably, the homogeneously branched ethylene interpolymer is characterized as having a melt index less than 100 g/10 minutes, more preferably less than 30, most preferably less than 10 g/10 minutes or in the range of 3 to 12 g/10 minutes, as determined in accordance with ASTM D-1238, Condition 190° C./2.16 kilogram (kg). ASTM D-1238, Condition 190° C./2.16 kilogram (kg) are referred to herein as I 2 melt index.
The homogeneously branched ethylene polymers for use in the invention can be either a substantially linear ethylene polymer or a homogeneously branched linear ethylene polymer. The term “linear” as used herein means that the ethylene polymer does not have long chain branching. That is, the polymer chains comprising the bulk linear ethylene polymer have an absence of long chain branching, as in the case of traditional linear low density polyethylene polymers or linear high density polyethylene polymers made using Ziegler polymerization processes (for example, U.S. Pat. No. 4,076,698), sometimes called heterogeneous polymers. The term “linear” does not refer to bulk high pressure branched polyethylene, ethylene/vinyl acetate copolymers, or ethylene/vinyl alcohol copolymers which are known to those skilled in the art to have numerous long chain branches.
The term “homogeneously branched linear ethylene polymer” refers to polymers having a narrow short chain branching distribution and an absence of long chain branching. Such “linear” uniformly branched or homogeneous polymers include those made as described, for example, in U.S. Pat. No. 3,645,992 and those made, for example, using so called single site catalysts in a batch reactor having relatively high ethylene concentrations (as described in U.S. Pat. Nos. 5,026,798 or 5,055,438) or those made using vanadium catalysts or those made using constrained geometry catalysts in a batch reactor also having relatively high olefin concentrations (as described in U.S. Pat. No. 5,064,802 or in EP 0 416 815 A2).
Typically, homogeneously branched linear ethylene polymers are ethylene/α-olefin interpolymers, wherein the α-olefin is at least one C 3 -C 20 α-olefin (for example, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-hexene, and 1-octene) and preferably the at least one C 3 -C 20 α-olefin is 1-butene, 1-hexene, 1-heptene or 1 octene. Most preferably, the ethylene/α-olefin interpolymer is a copolymer of ethylene and a C 3 -C 20 α-olefin, and especially an ethylene/C 4 -C 8 α-olefin copolymer such as an ethylene/1-octene copolymer, ethylene/1-butene copolymer, ethylene/1-pentene copolymer or ethylene/1-hexene copolymer. Suitable homogeneously branched linear ethylene polymers for use in the invention are sold under the designation of TAFMER by Mitsui Chemical Corporation and under the designations of EXACT and EXCEED resins by Exxon Chemical 5 Company.
The term “substantially linear ethylene polymer” as used herein means that the bulk ethylene polymer is substituted, on average, with 0.01 long chain branches/1000 total carbons to 3 long chain branches/1000 total carbons (wherein “total carbons” includes both backbone and branch carbons). Preferred polymers are substituted with 0.01 long chain branches/1000 total carbons to 1 long chain branches/1000 total carbons, more preferably from 0.05 long chain branches/1000 total carbons to 1 long chain branched/1000 total carbons, and especially from 0.3 long chain branches/1000 total carbons to 1 long chain branches/1000 total carbons.
As used herein, the term “backbone” refers to a discrete molecule, and the term “polymer” or “bulk polymer” refers, in the conventional sense, to the polymer as formed in a reactor. For the polymer to be a “substantially linear ethylene polymer”, the polymer must have at least enough molecules with long chain branching such that the average long chain branching in the bulk polymer is at least an average of from 0.01/1000 total carbons to 3 long chain branches/1000 total carbons. The term “bulk polymer” as used herein means the polymer which results from the polymerization process as a mixture of polymer molecules and, for substantially linear ethylene polymers, includes molecules having an absence of long chain branching as well as molecules having long chain branching. Thus a “bulk polymer” includes all molecules formed during polymerization. It is understood that, for the substantially linear polymers, not all molecules have long chain branching, but a sufficient amount do such that the average long chain branching content of the bulk polymer positively affects the melt rheology (that is, the shear viscosity and melt fracture properties) as described herein below and elsewhere in the 5 literature.
Long chain branching (LCB) is defined herein as a chain length of at least one (1) carbon less than the number of carbons in the comonomer, whereas short chain branching (SCB) is defined herein as a chain length of the same number of carbons in the residue of the comonomer after it is incorporated into the polymer molecule backbone. For example, a substantially linear ethylene/1-octene polymer has backbones with long chain branches of at least seven (7) carbons in length, but it also has short chain branches of only six (6) carbons in length.
The substantially linear ethylene polymers used in the present invention are a unique class of compounds that are further defined in U.S. Pat. Nos. 5,272,236, 5,278,272 and 5,665,800. The substantially linear ethylene elastomers and plastomers for use in the present invention are further characterized as having:
(a) melt flow ratio, I 10 /I 2 ≧5.63,
(b) a molecular weight distribution, Mw/Mn, as determined by gel permeation chromatography and defined by the equation: (Mw/Mn)≦(I 10 /I 2 )−4.63,
(c) a gas extrusion rheology such that the critical shear rate at onset of surface melt fracture for the substantially linear ethylene polymer is at least 50 percent greater than the critical shear rate at the onset of surface melt fracture for a linear ethylene polymer, wherein the substantially linear ethylene polymer and the linear ethylene polymer comprise the same comonomer or comonomers, the linear ethylene polymer has an I 2 and Mw/Mn within ten percent of the substantially linear ethylene polymer and wherein the respective critical shear rates of the substantially linear ethylene polymer and the linear ethylene polymer are measured at the same melt temperature using a gas extrusion rheometer,
(d) a single differential scanning calorimetry, DSC, melting peak between −30 and 150 C, and
(e) a density less than or equal to 0.895 g/cm 3 .
Determination of the critical shear rate and critical shear stress in regards to melt fracture as well as other rheology properties such as “rheological processing index” (PI), is performed using a gas extrusion rheometer (GER). The gas extrusion rheometer is described by M. Shida, R. N. Shroff and L. V. Cancio in Polymer Engineering Science, Vol. 17, No. 11, p. 770 (1977) and in Rheometers for Molten Plastics by John Dealy, published by Van Nostrand Reinhold Co. (1982) on pp. 97-99.
An apparent shear stress vs. apparent shear rate plot is used to identify the melt fracture phenomena over a range of nitrogen pressures from 5250 to 500 psig (369 to 35 kg/cm 2 ) using the die or GER test apparatus previously described.
The molecular weights and molecular weight distributions are determined by gel permeation chromatography (GPC). A suitable unit is a Waters 150 C high temperature chromatographic unit equipped with a differential refractometer and three columns of mixed porosity where columns are supplied by Polymer Laboratories and are commonly packed with pore sizes of 10 3 , 10 3 , 10 5 and 10 6 A. For ethylene polymers, the unit operating temperature is about 140° C. and the solvent is 1,2,4-trichlorobenzene, from which about 0.3 percent by weight solutions of the samples are prepared for injection. Conversely, for the substantially hydrogenated block polymers, the unit operating temperature is about 25° C. and tetrahydrofuran is used as the solvent. A suitable flow rate is about 1.0 milliliters/minute and the 5 injection size is typically about 100 microliters.
For the ethylene polymers where used in the present invention, the molecular weight determination with respect to the polymer backbone is deduced by using narrow molecular weight distribution polystyrene standards (from Polymer Laboratories) in conjunction with their elution volumes. The equivalent polyethylene molecular weights are determined by using appropriate Mark-Houwink coefficients for polyethylene and polystyrene (as described by Williams and Ward in Journal of Polymer Science, Polymer Letters, Vol. 6, p. 621, 1968) to derive the following equation:
M polyethylene −a*(M polystyrene )b
In this equation, a=0.4316 and b=1.0. Weight average molecular weight, M w , is calculated in the usual manner according to the following formula:
M j =( w i ( M i j )) j
where wi is the weight fraction of the molecules with molecular weight Mi eluting from the GPC column in fraction i, and j=1 when calculating M w and j=−1 when calculating Mi j . For the at least one homogeneously branched ethylene polymer used in the present invention, the M w /M n is preferably less than 3.5, more preferably less than 3.0, most preferably less than 2.5, and especially in the range of from 1.5 to 2.5 and most especially in the range from 1.8 to 2.3.
The homogeneously branched ethylene interpolymers (for example, substantially linear ethylene polymers and homogeneously branched linear ethylene polymers) used in the present invention are interpolymers of ethylene with at least one C 3 -C 20 α-olefin and/or C 4 -C 12 diolefin. Copolymers of ethylene and an -olefin of C 3 -C 20 carbon atoms are especially preferred. The term “interpolymer” as discussed above is used herein to indicate a copolymer, or a terpolymer, where, at least one other comonomer is polymerized with ethylene or propylene to make the interpolymer. Suitable unsaturated comonomers useful for polymerizing with ethylene include, for example, ethylenically unsaturated monomers, conjugated or non-conjugated dienes, polyenes, etc. Examples of such comonomers include C 3 -C 20 α-olefins such as propylene, isobutylene, 1-butene, 1-hexene, 1-pentene, 4-methyl-1-pentene, 1-heptene, 1-octene, 1-nonene, and 1-decene. Preferred comonomers include propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, and 1-octene, and 1-octene is especially preferred. Other suitable monomers include styrene, halo- or alkyl-substituted styrenes, vinylbenzocyclobutane, 1,4-hexadiene, 1,7-octadiene, and naphthenics (for example, cyclopentene, cyclohexene and cyclooctene).
In one preferred embodiment, at least one substantially hydrogenated block polymer is blended with at least one substantially linear ethylene polymer. In another preferred embodiment, at least one substantially hydrogenated block polymer is blended with at least one polypropylene polymer. Suitable polypropylene polymers for use in the invention, including random block propylene ethylene polymers, are available from a number of manufacturers, such as, for example, Montell Polyolefins and Exxon Chemical Company. From Exxon, suitable polypropylene polymers are supplied under the designations ESCORENE and ACHIEVE.
Other polymers that can be blended with either the substantially hydrogenated block polymer or the homogeneously branched ethylene interpolymer include, for example, but are not limited to, substantially hydrogenated block polymers, styrene block polymers, substantially linear ethylene polymers, homogeneously branched linear ethylene polymers, heterogeneously branched linear ethylene (including linear low density polyethylene (LLDPE), ultra or very low density polyethylene (ULDPE or VLDPE) medium density polyethylene (MDPE) and high density polyethylene (HDPE)), high pressure low density polyethylene (LDPE), ethylene/acrylic acid (EAA) copolymers, ethylene/methacrylic acid (EMAA) copolymers, ethylene/acrylic acid (EAA) ionomers, ethylene/methacrylic acid (EMAA) ionomers, ethylene/vinyl acetate (EVA) copolymers, ethylene/vinyl alcohol (EVOH) copolymers, polypropylene homopolymers and copolymers, ethylene/propylene polymers, ethylene/styrene interpolymers, graft-modified polymers (for example, maleic anhydride grafted polyethylene such as LLDPE g-MAH), ethylene acrylate copolymers (for example, ethylene/ethyl acrylate (EEA) copolymers, ethylene/methyl acrylate (EMA), and ethylene/methmethyl acrylate (EMMA) copolymers), polybutylene (PB), ethylene carbon monoxide interpolymer (for example, ethylene/carbon monoxide (ECO), copolymer, ethylene/acrylic acid/carbon monoxide (EAACO) terpolymer, ethylene/methacrylic acid/carbon monoxide (EMAACO) terpolymer, ethylene/vinyl acetate/carbon monoxide (EVACO) terpolymer and styrene/carbon monoxide (SCO)), chlorinated polyethylene and mixtures thereof.
The following examples are to illustrate the invention, and not to limit it. Ratios, parts and percentages are by weight unless otherwise stated.
EXPERIMENTAL
Fiber Descriptions:
Fiber made from Dow AFFINITY ethylene-octene copolymer (MI 3 g/10 min, density 0.875 g/cc) 140 Denier crosslinked by e-beam (19.2 mrad)
Generic spandex
Fabric Description:
3×1 RHT (right-hand twill); 100% cotton warp, 94% cotton/6% Crosslinked AFFINITY filling.
Example 1
Stone Washing
The stones were white pumas ranging approximately between 2-4 inches in diameter. The stones were soaked in the chemical solution for two (2) hours prior to testing.
Stone Wash/Decolorize - Hypochlorite Formula
Liquor
Water
Time
Chemical
Process
Ratio
Temp (F.)
(Min)
Quantity
Chemical
Comment
Stonewash/
10:1
140
90
10% soln. 5.25%
Sodium
3:1 Stone to
Hypochlorite
available Cl
Hypochlorite
Fabric ratio
(stone soak)
Drain/Rinse
10:1
170
10
Rinse
Neutralize
10:1
170
20
0.5 g/l
Sodium
Disulfite
Drain/rinse
Rinse Hot
Rinse Cold
Dry
Tumble Dry
Low
Stone Wash/Decolorize - Permanganate Formula Liquor Water Time Chemical Process Ratio Temp (F.) (Min) Quantity Chemical Comment Stonewash/ 10:1 140 90 5% soln. (stone Potassium 3:1 Stone to Potassium soak) Permanganate Fabric ratio Permanganate Drain/Rinse 10:1 170 10 Rinse Neutralize 10:1 170 20 0.5 g/l Sodium Bisulfite Drain/rinse Rinse Hot Rinse Cold Dry Tumble Dry Low
Test Results:
To understand the effects of stone washing on spandex, a sample of stretch denim comprising spandex was run in parallel with a sample of stretch denim comprising AFFINITY fiber. Although the properties of the two fabrics cannot be compared directly (the fabrics are of slightly different constructions), the data does show, however, property degradation in spandex-based denims and property retention in AFFINITY-based denims.
AFFINITY
Spandex
Denim
Denim
Test Procedures
Length
Width
Length
Width
Fabric Dimensional Change
−2.2%
−1.6%
4.9%
−10.2%
(AATCC 135) After Stone Wash,
Chlorine Bleach
Fabric Dimensional Change
−2.6%
−1.7%
−5.1%
−10.5%
(AATCC 135) After Stone Wash,
Permanganate
Stretch and Recovery
Stretch
Growth
Stretch
Growth
Comparison (ASTM D6614)
As Received
7.0%
2.9%
17.3%
4.5%
After 1x Stone Wash, Chlorine
7.3%
3.5%
28.3%
8.0%
Bleach
After 1x Stone Wash,
7.5%
3.5%
29.9%
10.1%
Permanganate
Denim fabric containing AFFINITY fiber did not have any significant change in stretch properties. When a commercially available spandex containing stretch fabric was subjected to the hypochlorite and permangenate washes, it exhibited deterioration in stretch properties and dimensional stability.
Example 2
Stripping Agents
Chemical Reduction by 1 g/L Sodium Hydrosulfite (Dye Stripping), 100° C./212° F., 1 hour:
Dye Stripping is a process to chemically remove color from fabric for redying. This test was performed as sodium hydrosulfite is a commonly used dye stripping agent. Since published research has shown some sensitivity on the part of elastomeric fibers to dye-stripping. Dyers prefer to work with a fiber that can withstand a stripping bath rather than one that will not.
Fiber Description:
Fiber made from Dow AFFINITY EG 8200 (MI 5 g/10 min, density 0.870 g/cc) 70 Denier crosslinked by e-beam (32 mrad)
Dupont Lycra 70 Denier
Dupont Lycra—Chlorine Resistant 70 Denier
Fiber Test Data
AFFINITY
Lycra
Lycra-CR
Ultimate Elongation
276.68
334.94
297.26
After Treatment (%)
% Difference against
−16%
−23%
−28%
as received
Breaking Load After
32.35
49.21
47.37
Treatment (g)
% Difference against
−53
−43
−33
as received
Example 3
Swimming Pool Water
100 ppm Sodium Hypochlorite (Chlorine Bleach), 50° C./120° F., 24 hours:
This accelerated test was performed as the hypochlorite ion is responsible both for bleaching and fiber damage in textiles, and it is also a chief cause in the degradation of fibers by swimming pool water. This level of chlorine was found by ruggedness testing to be roughly equivalent to the amount of exposure that would cause failure in a chlorine resistant Lycra® swimsuit after five months of use in which the suit was worn three times per week.
Fiber description:
P Fiber made from Dow AFFINITY EG 8200 (MI 5 g/10 min, density 0.870 g/cc) 70 Denier crosslinked by e-beam (32 mrad)
Dupont Lycra 70 Denier
Dupont Lycra—Chlorine Resistant 70 Denier
AFFINITY
Lycra
Lycra-CR
Ultimate Elongation
250.23
125.83
206.50
After Treatment (%)
% Difference against
−24%
−71%
−50%
as received
Breaking Load After
38.46
2.12
15.19
Treatment (g)
% Difference against
−44%
−98%
−79%
as received
Example 4
Wear Test
Fiber description:
Fiber made from Dow AFFINITY EG 8200 (MI 5 g/10 min, density 0.870 g/cc) 70 Denier crosslinked by e-beam (32 mrad)
A Speedo suit made of a two bar tricot construction with nylon and conventional Lycra spandex was obtained that displayed almost complete disintegration of the spandex component. Additionally new Speedo suits containing chlorine resistant Lycra spandex were purchased, and a swimsuit was constructed using weft knit polyester (about 88% by weight)/Dow AFFINITY fiber (about 12% by weight) fabric.
After a five-month wear trial test, the chlorine resistant suit displayed localized degradation. Scanning Electron Microscopy (SEM) images ( FIGS. 2 and 3 ) revealed that this degradation involved only the spandex filaments which were heavily degraded while the nylon filaments were untouched.
In contrast to the chlorine resistant spandex, the crosslinked AFFINITY elastomeric yarn contained in a similar swimsuit used in a four month wear trial displayed no degradation ( FIGS. 4 and 5 ). No significant bagging of the AFFINITY suit was found present and the suit was found to be functional in all ways with exception of the polyester yarn's propensity to stain readily when exposed to zinc oxide sun block, sun tan lotion and oil.
After completion of the wear trial, the AFFINITY suit was washed using the machine wash/warm tumble dry low cycle. The suit improved in appearance due to removal of stains and dirt accumulated over the period of the wear trial. After washing, the suit continued to fit well without bagging or excess shrinkage.
Example 5
Laundering
Stretch Properties of Fabric Containing AFFINITY Crosslinked Fibers:
Fabric description: 3×1 LHT (left-hand twill); 100% Nylon T-66 warp, 84% cotton/16% Dow AFFINITY EG 8200 (MI 5 g/10 min, density 0.870 g/cc) 70 Denier crosslinked by e-beam (22.4 mrad) filling.
Fabric Stretch, % weft direction
Laundry
(ASTM-D-6614-00)
Method
Conditions
1 cycle
25 cycles
50 cycles
MWH TDH SIM
From AATCC Test Method 135
66.6
70.2
73.0
machine wash hot
(normal cycle, 12 minutes), 140° F.
tumble dry high, 160° F.
steam iron medium, 300° F.
MWH TDH SIM
From AATCC Test Method 135
65.0
70.1
74.6
With Chlorine
machine wash hot
(CLOROX ®)
(normal cycle, 12 minutes), 140° F.
tumble dry high, 160° F.
steam iron medium, 300° F.
MWH TDH SIM
From AATCC Test Method 135
64.1
66.4
71.0
With Non-
machine wash hot
Chlorine Bleach
(normal cycle, 12 minutes), 140° F.
(CLOROX 2 ®)
tumble dry high, 160° F.
steam iron medium, 300° F.
The data in the above table demonstrates that the fabric experiences minimal change over 1 to 50 cycles.
Although the invention has been described in considerable detail through the preceding embodiments, this detail is for the purpose of illustration. Many variations and modifications can be made on this invention without departing from the spirit and scope of the invention as described in the following claims. All U.S. patents and allowed U.S. patent applications cited above are incorporated herein by reference.
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Durable stretch fabrics are made and processed from one or more crosslinked, heat-resistant olefin elastic fibers, e.g., a substantially linear, homogeneously branched ethylene polymer. The fabrics can be made by any process, e.g., weaving, knitting, etc., and from any combination of crosslinked, heat-resistant olefin elastic and inelastic (“hard”) fibers, e.g., cotton and wool. These fabrics exhibit excellent chemical, e.g., chlorine, resistance and durability, e.g., they retain their shape and feel (“hand”) over repeated exposure to processing conditions, e.g., stone-washing, dye-stripping, PET-dyeing and the like, and service conditions, e.g., washing, drying, etc.
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BACKGROUND OF THE INVENTION
This invention relates to hair cutting devices and more particularly to a hair cutting device wherein the bodily movement of the device adjacent the surface of a head to cut hair and the movement of the clipper blade portion of the device a controlled distance from the surface of the head are operatively effected in controlled relation with each other.
In a conventional hair cutting device, the distance between the device and the head is adjusted in accordance with the skill and judgment of the barber and considerable skill is consequently required for cutting hair. A hair cutting device wherein the distance between the head surface and cutting blade end surface can be automatically adjusted in accordance with the movement of the hair cutting device along the head surface has not previously been known.
The present inventor is the inventor of a "Hair Cutting Device" as shown in U.S. Pat. No. 4,150,483. The present invention represents a new improvement and advance over the aforementioned device.
An object of the present invention is to provide a hair cutting device in which the movement of the device and the distance of the cutting blade end surface from the head surface are jointly operatively connected and controlled.
The above-mentioned and other objects and advantages of the present invention will be made clear from the following description.
SUMMARY
The hair cutting device of the present invention comprises an electrically operated clipper and an open-ended hollow casing wherein the fixed cutting blade end surface of the clipper is arranged in the open end of the casing so that both end surfaces can be in the same plane, the clipper is moved relative to the open end in the casing by threads on rotary drums connected to an external object positioned adjacent the hair to be cut. A resilient member connects the casing with the clipper and returns the clipper to the original position. A power transmitting thread connects the above-mentioned rotary drum means with the clipper to operatively effect the displacement of the clipper in the casing so that the drums can be rotated to change the relative position of the clipper within the casing.
In the hair cutting device of the present invention, sliding members are provided on the side surface of the clipper, guide rails for the above-mentioned sliding members are provided on the casing and the resilient member connecting the clipper with the casing can be formed on a second rotary drum within the casing on the fixed cutting blade end surface of the clipper. A second thread is fixed at one end on the second drum and connected at the other end to a fitting member on the side surface of the clipper; a spring is supported at one end by the casing and a third thread is wound reversely to the second thread and fixed at one end on the second drum and connected at the other end to the spring.
The power transmitting means of the hair cutting device can also be formed of a rotary drum on which a thread connected to a connector is wound and which is pivoted within the casing at the end on the other side of the end on the fixed cutting blade side of the clipper and a thread wound reversely to the thread connected to the connector is fixed at one end on this drum and connected at the other end to a connector member on the side surface of the clipper in the form of a pulley provided on the side surface of the clipper. A thread wound on the pulley is fixed at one end to the casing and is wound reversely to the other thread on the rotary drum. Driving movement to the clipper can also be effected by a pinion provided integrally with the rotary drum on which the thread connected to the connector is wound and a rack engaged with the pinion and provided on the side surface of the clipper.
The device of the present invention can be also of a formation wherein a clipper in which the fixed cutting blade end surface is inclined to the casing and clipper axis. First and second rotary drums are coaxially pivoted within the casing to the fixed cutting blade side end of the clipper, a first thread connected to a fixer is wound and fixed at the end on the first drum, a second thread is connected to a fitting member on the side surface of the clipper and a third thread is connected to a spring supported at one end by the casing are wound respectively reversely to each other and fixed at the ends on the second drum; a fourth thread is wound reversely to the first thread as fixed at one end on the first drum and is wound reversely to the winding on the first drum as fixed on a third drum pivoted within the casing to the end on the other side of the fixed cutting blade side end of the clipper. A fifth thread connected to a fitting member on the side surface of the clipper is wound reversely to the winding of the fourth thread as fixed on the third drum and the clipper is provided with slide members and the casing can be provided with guide rails for the above-mentioned slide members so as to linearly slide and displace the clipper. Alternatively, the clipper can be pivoted at the end on the other side of the fixed cutting blade side end to the casing so as to be rocked and displaced.
The rotary drums included in the hair cutting device of the present invention can have the thread winding cylinders made properly different from one another in the diameter so that the distance of the displacement of the clipper with the movement of the device can be varied and further a member making the peripheral edge of the cutting blade of the clipper communicate with a vacuum source can be provided.
In order to fit the connector to the hair cutting device of the present invention, there is provided a fitting member wherein a forehead contacting member, a chin receiving member, and a guide member for the above-mentioned connector are fitted to a supporting member so as to be adjustable in position. The casing to which the connector is connected through an internally fitted rotary drum is fitted to an electrically operated clipper so that the clipper is displaced with respect to the casing with the variation of the relative positions of the casing and connector.
The hair cutting device of the present invention can be also of a structure wherein a graduation is attached to the side surface of the clipper or its sliding member, a base line is attached to the casing side surface and a fixer or a thread clamping piece connected to the fixer is provided on the side surface of the casing so that the cutting blade of the clipper can be fixed at a predetermined distance from the tool end surface of the casing.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a side view of a first embodiment;
FIG. 1B is a plan view of FIG. 1A;
FIG. 1C is a bottom view of FIG. 1A;
FIG. 2 is partly sectioned elevation of FIG. 1A;
FIG. 3 is a partly sectioned view of FIG. 1A;
FIG. 4A is a sectioned view along line IVA--IVA in FIG. 2;
FIG. 4B is a sectioned view on line IVB--IVB in FIG. 2;
FIG. 5 is a sectioned view showing another embodiment;
FIG. 6A is a partly sectioned side view showing another embodiment;
FIG. 6B is a sectioned view on line VIB--VIB in FIG. 6A;
FIG. 7A is a partly sectioned side view showing another embodiment;
FIG. 7B is a sectioned view on line VII--VII in FIG. 7A;
FIG. 8 is a partly sectioned view showing another embodiment;
FIG. 9A is a partly sectioned view showing another embodiment;
FIG. 9B is a sectioned view on line IX--IX in FIG. 9A;
FIG. 10 is a partly sectioned view showing another embodiment;
FIG. 11 is a partly sectioned view showing still another embodiment;
FIG. 12 is a side view of a tip of an embodiment;
FIG. 13 is a side view of an embodiment of the hair cutting device fitting member of the present invention;
FIG. 14A is a side view of another mode of the forehead contacting member;
FIG. 14B is a view seen in the direction A of FIG. 14A; and
FIG. 15 is a side view of another mode of the chin receiving member.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The embodiments of the present invention shall be explained with reference to the drawings. In the embodiment shown in FIGS. 1 to 4, reference numeral 1 denotes a casing fitted to a clipper 2 so that the fixed cutting blade end surface 3 of the clipper 2 may coincide with the open end 4 at the end of the casing 1. First and second rotary drums 5 and 6 are provided adjacent the upper and lower ends of the casing 1. A first thread or cord 8 is connected by its free end to a connector 7 provided outside the casing and is wound and fixed at its opposite end on the first rotary drum 5. Thread 8 also extends over a guide pulley 9 attached to the rotary drum 6 on the cutting blade end of the clipper 2. Further, a second thread or cord 10 is wound reversely to the above-mentioned thread 8 is fixed to the rotary drum 5 and is fixed at the other end to a fitting 11 formed on the side surface of the clipper 2.
Also, a third thread or cord 12 is fixed at one end to the fitting member 11 and is wound on the rotary drum 6 and is fixed at one end to the rotary drum 6. A fourth thread 13 is fixed at one end to the second rotary drum 6 and is wound on the drum reversely to the above-mentioned thread 12 and is connected at an opposite end to a spring 14 supported by the casing 1.
Further, guide rails 25 to guide the movement of the clipper 2 are arranged within the casing 1 and slide members 26 attached to clipper 2 are mounted for sliding movement on the guide rails 25 so that the clipper 2 can move in a stable manner while operatively connected by thread means with the rotary drums. The clipper 2 is of a conventional electrically operated type receiving power via an electrical cord 21 and has its fixed cutting blade end surface 3 vertical to the axis of the clipper 2 as shown in FIG. 3. The fixed cutting blade end surface on the clipper may also be inclined to the axis of the clipper as shown in FIG. 8.
The hair cutting device is used by fixing the connector in a position adjacent the lower edge of the hair on the neck of the person having his hair cut as shown in FIGS. 13 to 15 in which the fitting member comprises a supporting member 33, forehead contacting member 37, chin receiving member 42, and guide member 50. The supporting member 33 consists of a carrier rod 35 and base plate 34 which can be free-standing on a table or the like to the heavy weight of base plate 34. A scale 36 is attached to the side surface of the carrier rod 35 and the positions of the forehead contacting member 37, the chin receiving member 42 and guide member 50 will be able to be quickly adjusted in response to a desired position with respect to the head being cut.
The forehead contacting member 37 has a forehead restrainer 38 and an adjustable slide sleeve 39 and is fixed in a proper position by a clamp 40 or carrier rod 35. The forehead restrainer 38 is formed so as to be rotatable with respect to the slide rod 39 and the inclination of the forehead contacting surface can be made properly adjustable by fixing clamp knob 41 as shown in FIGS. 14A and 14B.
The chin receiving member 42 includes a chin support 43 carried on a slide tube 47 adjustably positioned on a carrier shaft 46 extending from a carrier sleeve 44 which is clamped in position on carrier rod 46 by clamp knob 45. Slide tube 47 is clamped in position on carrier rod 46 by clamp knob 48. The chin receiving support 43 is rotatable with respect to the fitting tube and can be held in adjusted rotary position by clamp knob 49. Thus, the chin receiving support 43 can be properly adjusted as shown in FIG. 15.
The guide member 50 consists of a guide frame 51 and a supporting part having an adjustable rod 53 held in adjusted position on the outer end of an arm 55 by a clamp knob 54. Arm 55 includes a slide sleeve 56 which can be clamped in desired position on carrier rod 35 by clamp knob 57. Connector 7 of the hair cutting device is connectable to a fitting part 52 on frame 51. The supporting rods 53 are inserted through the tips of two supporting arms 55 protruded out of the sleeve 56 and can be fixed in proper positions with clamp knobs 54.
Therefore, in the fitting apparatus of the present invention, the forehead contacting member 37, chin receiving member 42, and guide member 50 are fixed in properly adjusted positions, the inclinations of the contacting surface of the forehead restrainer 38 and chin receiving surface of the chin support 43 are adjusted as required for the particular human head whose hair is to be cut. The guide frame 51 is positioned and fixed on the lower edge of the hair on the rear part of the head, and the connector 7 of the hair cutting device is fitted to the guide member and the casing 1 and clipper 2 are moved along the surface of the head to permit the clipper to cut the hair.
When the clipper 2 is moved together with the casing 1, the thread 8 wound on the rotary drum 5 will be unwound, thereby the second thread 10 wound reversely on the rotary drum 5 will be wound onto the rotary drum 5, and the clipper 2 will gradually be moved and the fixed cutting blade end surface 3 will gradually move away from the open end surface 4 of the casing 1. Therefore, when the casing 1 is moved upwardly from the lower edge of the head, the clipper 2 will accordingly separate from the open end surface 4 of the casing 1 and will progressively move away from the head to leave the hair longer as it moves up the head as shown in FIG. 13.
By this movement of the clipper 2, the thread 12 fixed to the clipper 2 will be unwound from the rotary drum 6, at the same time, the thread 13 will be wound up on the rotary drum 6 and the spring 14 will be stretched. If the casing 1 is returned to the original position, the spring 14 will cause the clipper 2 to return to the original position in the casing 1 shown in FIG. 1A.
Thus, the connector 7 can then be shifted sideways on guide frame 51 to trim an adjacent area of the head along a cutting path adjacent the previous path of clipper travel over the head.
FIG. 5 illustrates an alternative rotary drum 5, 6 having canted winding surfaces which can be used in place of drum 5 to give a different contour to the haircut provided by the apparatus.
In the embodiment shown in FIG. 6A and 6B, the thread 10 is wound on the rotary drum 5 and is fixed at the end to the inner wall of the casing 1 through a pulley 22 provided on the side surface of the clipper 2 so that the rotation of the drum will operatively effect the displacement of the clipper relative to casing 1. In such case, the moving distance of the clipper 2 with the movement of the casing will be smaller than it is when the thread 10 is fixed to the fitting member 11 of the clipper 2 as in the embodiment of FIGS. 1A, etc.
In the embodiment shown of FIG. 7A and 7B, instead of the motion transmission being effected by using the thread 10, a pinion 23 is attached to the rotary drum 5 and a rack 24 is provided on the side surface of the clipper 2 so as to mesh with the pinion so that rotation of the pinion shifts the clipper longitudinally.
Rotary drums 6a and 6b of the embodiment of FIGS. 9A and 9B are rotated, and a thread 8a is connected to the connector 7 and is wound and fixed at the end on the drum 6a. A thread 12 is connected to a fitting member 11b on the clipper and a thread 13 is connected to a spring 14 supported at one end by the casing 1. Threads 12 and 13 are wound reversely to each other so that when the thread 12 is unwound, the thread 13 will be wound. A thread 8b is attached to one end of the rotary drum 6 and is wound reversely to the thread 8a so that when thread 8a is wound, 8b will be unwound. A thread 10 is mounted on drum 5 and connected to a fitting member 11a on the side surface of the clipper and is wound on drum 5 reversely to the winding of the thread 8b. The clipper 2 is pivoted at one end opposite the fixed cutting blade end surface to the casing 1 by a pin 27 so that the clipper may be pivoted about the pin 27 as a fulcrum and the fixed cutting blade end surface 3 of the clipper 2 may be separated along an arcuate path from the opening surface 4 of the casing 1.
In the embodiment in FIG. 8, sliding members 26 are provided on the side surface of the clipper 2 and guide rails 25 for the above-mentioned sliding members 26 are respectively provided at right angles with the open end surface 4 in the casing so that the clipper 2 can move vertically.
By properly varying the diameters of the respective rotary drums of the hair cutting device of the present invention, the moving speed of the clipper 2 can be varied and the curve of the finished surface of cut hair can be varied. For example, as in the embodiment shown in FIGS. 2 and 4, steps are formed on the rotary drums 5 and 6 so that the respective threads can be wound on the drum surfaces of the respective steps. Further, as in the embodiment shown in FIG. 5, tapered steps may be formed on the rotary drum.
In the embodiment shown in FIG. 10, a flow path 29 is connected to a vacuum source (not illustrated) through a flexible tube 28 and has an end near the cutting blade of the clipper 2 so that hairs will be sucked in through the flow path 29 and will be prevented from being scattered over the surrounding area. It should be understood that such a vacuum flow path 29 can be provided not only in the embodiment shown in FIG. 10 but also in any other embodiment.
In the hair cutting device of the present invention, a comb 30 can be provided outside near the cutting blade of the clipper so that hair can be cut while being raised by the comb 30 and the finished surface can be made better. Additionally, the comb 30 can be provided so as to be adjustable vertically and removable.
Further, as shown in the embodiment of FIG. 11, a graduation can be made on the side surface of the clipper 2 adjacent a base line mark made on the casing 1. A set screw 32 or any other clamping member having a washer 31 can clamp thread 8 connected to connector 7 so that the thread 8 is fixed to the casing and the distance between the opening surface 4 of the casing the fixed cutting blade end surface 3 of the clipper 2 is set so that the casing 1 and clipper 2 will keep their relative positions and so-called 5% cut, 30% cut, or 50% cut can be made without using any auxiliary device.
As described above, according to the present invention, without requiring any skill, any desired hair cut can be easily made at any convenient location such as at home.
Further, since the fitting member of the present invention can be fixed in a predetermined position of the head without applying any load to the human body, the hair can be smoothly cut.
It should be understood that the spirit and scope of the present invention is not to be limited by the disclosed embodiments but is to be limited solely by the appended claims.
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A hair cutting unit device for the human head includes a movable open-ended casing in which an electrically operated clipper is mounted on guide means for movement. The blades of the clipper are in the open end of the casing. The position of the clipper with respect to the casing will fluctuate so that the cutting blades are moved away from the open end as the unit is moved upwardly on a head from the lower hairline so as to gradually increase the length of hair being left on the head. Rotary drums and threads in the casing are connected to a fixed member in which the head is positioned to effect translation of the clipper relative to the casing in response to movement of the unit upwardly from the lower hairline.
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This is a continuation-in-part, of application Ser. No. 426,620 filed Sept. 29, 1982 now abandoned.
BACKGROUND OF THE INVENTION
Before pulp is formed into paper, it is almost invariably subjected to mechanical treatment in order to shorten, abrade, and internally fibrillate or bruise the structure of the fibers in the desired proportion and degree. The present method of accomplishing this is to make a slurry of the pulp with a concentration (consistency) of 3% to 5% and crush and rub the mixture between disks fitted with narrow metal bars disposed nearly radially. The relative speed of the bars is usually from 3,000 to 6,000 feet per minute and the pressure between the faces of the bars may be as high as 1,000 p.s.i. Consequently, the operation consumes a very large amount of energy for the resulting disruption of the fibrous structure. It is well recognized that, considering the results, the present method mechanically is a most inefficient operation.
An obvious approach to save energy which has no doubt been tried is to crush a layer of wet fibers between smooth rolls. However, it is not possible to feed any practical amount of wet fibers through such a nip, because water is squeezed from the pulp before it reaches the nip and the expressed water prevents the roll surface from grasping the pulp. Roughening the surfaces is no solution because the roughness would not much improve adhesion because the expressed water would tend to push and float the fibers away. Furthermore, the roughness would cut the fibers unduly, even if satisfactory feeding were possible.
It should be mentioned that with common barred machines, fiber clots are formed on the rapidly moving edges of the bars, which are further dewatered on the edges of the opposing bars when they come into contact. For effective treatment it is necessary that the clots of pulp be dewatered to about 50% dry before mechanical treatment.
Fifty years ago, I designed a laboratory apparatus constructed to beat a small batch of about three ounces of pulp prior to making it into test sheets of paper so as to evaluate its properties. The apparatus comprised three heavy rollers with 9-mm wide rims having 3 mm wide central grooves, the rollers restrained by gearing to rotate within a frame around a smooth, flat circular track around the bottom of a V-shaped annular trough. It and other beating devices have been described in detail by me in my textbook Pulp Technology and Treatment for Paper, pages 331 to 333, published by Miller Freeman in San Francisco in 1978 said disclosure being incorporated herein by reference.
Although the described laboratory apparatus was successful and has since been adopted as one of four instruments to carry out one of the official test methods of the Technical Association of the Pulp and Paper Industry (T225 OS-75), its principle of operation was not until recently fully understood; nor was it envisaged how the tiny laboratory batch apparatus could be modified and transformed into a simple, large, commercial machine having a continuous and substantial output of several tons an hour as is now described in the present invention.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a novel method and means for refining paper pulp with the minimum amount of energy.
It is another object to provide a simple means for controlling the intensity of treatment of the pulp.
It is still another object to provide means for emphasizing one or the other of the three basic actions of refining, namely, shortening, abrading, and crushing of the fibers.
These and some of the other objects and advantages of the invention will hereinafter become apparent.
DESCRIPTION OF THE DRAWINGS
FIG. 1 shows somewhat schematically a front view partially in section of an apparatus embodying the invention through 1--1;
FIG. 2 shows a side view partially in section taken through 2--2 of FIG. 1 of the apparatus;
FIG. 3 shows a front section taken through 3--3 of FIG. 4 showing a means of applying pressure to the rolls.
FIG. 4 shows a side section taken through 4--4 of FIG. 3;
FIG. 5 shows a rotating toothed shaft adapted to keep clean the circumferential grooves on a roll;
FIG. 6 is an end view taken through 6--6 of FIG. 5;
FIG. 7 shows a side view of a portion of one form of nip between the grooved center drum and a smooth roll;
FIG. 8 shows the side view of another form of the nip between a smooth roll and the center drum with circumferential and longitudinal grooves;
FIG. 9 shows a side view of a portion of another form of nip between the grooved center drum and a grooved outer roll;
FIG. 10 shows the front view of a portion of the center drum and a roll both longitudinally and circumferentially grooved; and
FIG. 11 is a side view of part of FIG. 10 through 1--1.
DETAILED DESCRIPTION
Basically, the method of treating pulp fibers in accordance with the present invention involves mixing the fibers with sufficient water to form a slurry, directing a continuous stream of the slurry to a series of narrow nips located between a pair of revolving rolls, the widths of the nips being less than that which would cause the slurry carrying a major portion of the fibers to enter the spaces between the sides of the nips as the rolls revolve, and pressing the revolving rolls together with a predetermined force adequate to provide the desired effect on the fibers from the slurry that pass between the nips. The narrow nips have contacts thereon whose widths do not exceed significantly the lengths of the longest fibers in the slurry, so the contacts generally have widths not exceeding about 9 mm and preferably of 3 mm or less.
By so adjusting the relationship between the row of intermittent contacting widths in the nips, they grab and dewater the fibers before crushing them, allowing the water to flow through the spaces between the contacting widths. This action will not happen if the contacts are much wider than the longest fibers in the slurry, because in that case, the individual nips would push the slurry sideways to the openings and not allow them to grab any but a tiny proportion of the fibers.
In the preferred embodiment of the invention there are a large number of contacting elements along the length of the roll, each element preferably having a width of less than three times the average lengths of the fibers in the pulp with channels between the elements of sufficient size to permit passage of the water squeezed from the pulp by adjacent elements. Thus, the spacing between the contacts is insufficient to cause most of the slurry presented to them to be pushed to the openings between the contacts.
Another feature of the present invention involves continuously mechanically dispersing clots of pulp that are compressed in the nips.
In the drawings 12 indicates the outer cylindrical casing of one form of the apparatus of the invention. Mounted on a shaft 13 driven by a motor (not shown) is a circumferentially grooved drum 14. Spaced around the drum are a number of usually plain rolls 15 each of which has a shaft 16, the ends of which pass through holes in the sides of the casing 12 and rotate on bearings 17 which are housed at the ends of lever arms 18 which are pivoted on pins 19 affixed to both sides of the casing. Normally only the grooved drum 14 is driven, the rolls 15 being rotated by friction. However, all the rolls 15 may be geared together and driven separately. In this case, with some paper stocks, it may be desirable to subject the fibers to additional rubbing by arranging for a differential peripheral speed between the drum 14 and the rolls 15.
The casing 12 has an inlet 20 and an outlet 21 (shown schematically by arrowed lines) for the pulp slurry which at the desired consistency is pumped through the apparatus at the desired rate depending on the extent of treatment required.
The rolls 15 from both sides are pressed against the driven drum 14 by a circular piston 22, FIG. 3, sliding in a casting 23 which piston is part of the arm 18 and which is activated by fluid pressure supplied through inlets 24 to a rubber diaphragm 25, all of which inlets may be connected to a common fluid pressure source. If the apparatus is not operated in a vertical but in a horizontal position, the arm of each roll is supplied, for example, with a leaf spring 31 held at one end by a stud 32 affixed to one side of the casing 12 and by means of screw 33 turning in pillar 34, caused to balance the weight of rolls 15 if the rolls are situated on the upper part of the casing or if the rolls are on the lower part, to apply upward pressure to arm 18 to support the weight of the rolls. The springs will not be needed for the two rolls in the middle. It will be observed that the movement of the rolls 15 needs to be only very small, enough to provide some flexibility if a large lump of pulp goes through the nip.
Referring to FIGS. 5 and 6 located adjacent to the outgoing sides of each of the nips between all the rolls 15, adjacent the drum 14 is a milled shaft 26 driven by a high speed motor (not shown). The shaft 26 carries spike wheels 27 which have teeth 27a milled in the periphery so that the tips sweep through the grooves on drum 14 and keep them clear in case any pulp should plug their grooves. A simple means of preventing leakage through the sides of casing 12 is to have the shaft 26 pass through an opening in a seal 28 which is held in place by a ring 28a held by bolts 29a against the housing end 29. The seal is made of rubber or suitable sealing material constructed essentially as illustrated for sealing the rotary shaft. A similar construction for shaft 16 is shown in FIG. 4 where the seal is shown simplified for purposes of illustration only as a rubber disk 28 with a shaft opening therethrough and it will be understood that various forms of seals may be employed. The milled shaft 26, FIGS. 5 and 6 and teeth 27a have the additional and desirable function of dispersing clots of pulp that were loosened after being compressed in the nips.
FIG. 7 shows one type of contact between the rolls 15 and the drum 14 which by adjusting the pressure to about 30 pounds per land width of about 1/8 in. and the concentration (consistency) of the pulp to about 3% gives results similar to that of barred apparatus with respect to shortening abrasion and crushing all of which occur to some degree.
It is contemplated that a pattern illustrated in FIG. 8 will enhance the shortening effect if this is desired, and that shown in FIGS. 9 and 10 will enhance the abrading effect. The patterns are not to be presumed restricted to those shown but may assume a number of different forms depending on the type of pulp, the type of paper desired, the consistency of the pulp, the applied pressure between the rolls, and the throughput.
The means of keeping teeth in the rolls 14 and 15 clean and the pulp dispersed in the pattern shown in FIG. 10 and 11 may take the same form as shown in FIGS. 5 and 6, operating in circumferential grooves spaced around the rolls, whereas that shown in FIG. 9 may require the shafts to be situated that the teeth are applied to each roll.
It will be obvious that many modifications to the apparatus may be made without departing from the spirit of the invention which is mainly that of providing a very flexible treatment of pulp for paper with a minimum of energy as compared to existing machines.
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A method and apparatus is disclosed for treating pulp prior to being made into paper, which treatment is known as beating or refining. The method comprises feeding a slurry of the pulp to the narrow nips of grooved rolls at which the slurry of pulp is partially dewatered then almost simultaneously fragments of the pulp are subjected to a predetermined heavy pressure, then dispersed before being subjected to the same sequence until treated to the desired degree.
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FIELD OF THE INVENTION
[0001] The present invention relates to paper making machines and, more particularly, to press rolls employed in paper making machines and, most particularly, to an apparatus for removing water from the shoe press sleeve or belt in the press section of a paper making machine.
BACKGROUND OF THE INVENTION
[0002] Paper, linerboard, and other sheet products produced from cellulose fibers are produced in a paper making machine by depositing an aqueous slurry of cellulose fiber containing various additives from a head box on a fabric screen to form a cellulose mat. Water is extracted from the slurry via vacuum boxes positioned below the fabric leaving a mat or sheet of cellulose fibers on the fabric. The mat is then transferred to a continuous press felt. The felt and mat are then run to a first pair of nip rolls, commonly referred to as a top press roll and a bottom press roll. Additional water is extracted from the mat as it passes between the top and bottom press rolls. A polyethylene sleeve or belt is mounted on one of the press rolls, typically the top press roll. Circumferential grooves are provided in the sleeve to allow the water being squeezed from the mat to travel laterally and thus extract it from the mat. Some of this water is removed from the grooves by the centrifugal force created by the spinning top press roll.
[0003] However, it has been observed that water may still puddle ahead of the nip between the press rolls. The presence of this water detracts from the performance of the press rolls. It is therefore desirable to reduce or eliminate the puddling that occurs ahead of the nip between the press rolls. Heretofore, however, the origin of the water that puddles ahead of the nip and how to remove that water have not been fully understood.
SUMMARY OF THE INVENTION
[0004] It has now been recognized that despite removal of water from the top press roll by centrifugal force, much water still remains on the surface of the rolls and particularly in the circumferential grooves in the sleeve. The present invention removes this water from the surface and the grooves by providing a means for wiping the surface of the grooved sleeve. This is accomplished with a top press roll wiper blade mounted in a bracket, which in turn is mounted on the paper making machine framework. The wiper blade has an edge that is positioned in contact with the surface of the sleeve upstream from the nip between the top and bottom press rolls. As the top press roll spins in the direction of the wiper blade and the nip, the wiper blade removes water from the surface of the sleeve and, moreover, removes water from the circumferential grooves in the sleeve. In a preferred form of the invention, the wiper blade is mounted for movement toward and away from the sleeve so as to allow for varying the pressure of the wiper blade on the sleeve and for retracting it from contact with the sleeve when it is not needed, or for repair or replacement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:
[0006] [0006]FIG. 1 is a schematic view of top and bottom press rolls in a paper making machine along with a preferred form of the wiper blades constructed in accordance with the present invention;
[0007] [0007]FIG. 2 is an enlarged side view of the wiper blade shown in FIG. 1;
[0008] [0008]FIG. 3 is a top view of a segment of the wiper blade and mounting mechanism shown in FIG. 2; and
[0009] [0009]FIG. 4 is an illustration of a top press roll, a wiper blade, and a trough constructed in accordance with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0010] Referring first to FIG. 1, the first set of press rolls 10 of a press section of a conventional paper making machine is shown in phantom. The press section of a conventional paper making machine may have more than one set of press rolls. The bottom press roll 12 is usually mounted on the paper making machine framework for rotation in a counterclockwise direction. The top press roll 14 is mounted for rotation in a clockwise direction. The top press roll is conventionally mounted so that it can be moved up and down, that is, toward and away, from the bottom press roll 12 . A felt 18 forming part of the press carries a mat of cellulose fibers between the nip 16 of the top and bottom press rolls. In this view, the paper mat is omitted for purposes of simplicity. The top press roll 14 normally carries a sleeve (shown in FIG. 2 as 26 ) that carries a plurality of circumferential grooves that assist in extracting water from the mat of cellulose fibers being run through the nip 16 between the rolls 12 and 14 . A wiper blade 20 constructed in accordance with the present invention is mounted on a blade mounting assembly 22 , in turn mounted on framework 24 of the paper making machine.
[0011] Referring now to FIGS. 2 and 3, the blade 20 is positioned against the grooved sleeve 26 forming part of the top press roll 14 . The blade 20 itself is an elongated member that is at least the length of the sleeve 26 . A cross-sectional profile shows the blade coming to a sharp edge at the instance where it contacts the sleeve 26 . The opposite edge of the blade is fixed to the mounting assembly 22 as described further below. Although the blade is shown as a straight edge, in other embodiments the blade edge may be profiled to match the groove profile in the sleeve. For grooved sleeves, the blade edge would then be provided with protrusions to match the profile of the grooves. Groove profiles may be trapezoidal, square, U-shaped, or any other profile. It is also to be appreciated that other surface patterns besides grooves may be machined on the sleeve. For example, a drilled pattern sleeve can be used in place of a grooved sleeve.
[0012] The blade assembly 22 has a first section 30 that is pivotally attached to a second section 32 . Opposing flanges 34 and 36 extend from the first and second sections 30 and 32 , respectively, and are coupled together by a pivot pin 38 . The axis of the pivot pin 38 is substantially parallel to the rotational axis of the top press roll 14 . The blade 20 is secured in the first section 30 of the bracket by conventional fasteners, such as bolts 40 . The second section 32 of the blade mounting assembly is affixed to an L-shaped bracket 42 by a conventional fastener 44 such as a bolt. The L-shaped bracket 42 has an upright arm 42 b and a generally horizontal arm 42 a, which rests on a horizontal surface 46 forming part of the main framework 24 of the paper making machine. The L-shaped bracket 42 is mounted for movement toward and away from the press roll 14 in the direction of arrows 48 . A jack screw assembly 50 is employed to adjust the position of the L-shaped bracket relative to the top press roll 14 . The screw 50 a is rotatably mounted in flange 52 attached to framework 24 . A threaded nut 50 b is affixed to bracket 42 . A lock nut 53 is employed to lock the screw 50 a to the nut 52 b. The jack screw mechanism provides a gross positioning of the blade mounting assembly 22 relative to the press roll 14 .
[0013] The entire blade assembly and captive blade extend the entire length of the top press roll 14 . Only one end portion of the blade 20 and mounting assembly 22 is shown in FIG. 3. Several of the jack screw mechanisms 50 are placed at intervals along the length of the blade mounting assembly. In a preferred installation, it is preferred that the blade 20 be mounted less than about 90 degrees from the nip 16 of the top press roll 14 .
[0014] The blade mounting assembly 22 also has a pair of bladders 54 and 56 mounted between the first and second sections 30 and 32 and above and below the pivot pin 38 . The bladders are coextensive in length with the blade mounting assembly 22 . Selective inflation of the bladders 54 and 56 allows the first section 30 to be pivoted to and fro so that the blade 20 can be moved toward and away from contact with the surface of the sleeve 26 and so that variable pressure can be applied by the leading edge blade of the wiper blade 20 against the surface of the sleeve 26 . In other embodiments, the bladders 54 and 56 can be replaced with other equally suitable biasing devices, including leaf or coil springs. In a preferred embodiment, the blade mounting assembly is constructed so as to allow movement of the blade toward and away from the surface of the sleeve 26 of the top press roll 14 from one to two inches. The blade load may be adjusted so that loads on the order of 0.2 pounds per linear inch (PLI) (36 grams per cm) can be applied by the blade against the surface of the press roll sleeve 26 .
[0015] In a preferred embodiment, the sleeve 26 of the top press roll is preferably comprised of polyethylene. The grooves in the sleeve 26 are conventionally machined into the surface of the polyethylene. It is also preferred that the blade 20 also be made of polyethylene. Thus, when the blade is brought into contact with the press roll sleeve 26 , a minimum of frictional wear is created. Without the wiper blade of the present invention, the sleeve appears to be free of water. However, when the blade is positioned against the sleeve, substantial amounts of water are removed. Measurements have shown that on the order of an additional 66 gallons of water per minute are removed from a sleeve in the press section of a paper making machine running at an overall output of 58 tons per hour of paper. This results in substantial overall energy savings in the paper making process because the amount of water that is removed from the sleeve is not required to be evaporated from the fiber mat at a later stage.
[0016] Referring now to FIG. 4, one embodiment of the present invention is illustrated, whereby a trough 50 is located below the blade 20 . The trough has a lower base 56 surrounded by peripheral walls 58 , thus forming a collection basin for water that may run off from the outboard side of the blade 20 . The water is indicated by arrows 52 . The trough 50 has sufficient width to also collect water that may run off from the inboard side of the blade 20 , said water run off being indicated by arrow 54 . Lengthwise, the trough 50 is at least as long as the blade 20 . The trough 50 has sufficient volume to contain the expected water collection from the sleeve surface 26 and the sleeve grooves 26 a. The trough 50 is inclined, meaning that one end of the trough is at a higher relative position than its opposite and lower end. At the lower end, a pipe 60 , or other suitable conduit, may be connected to channel away the collected water from the roll. The trough 50 may be positioned at any location below the blade 20 . However, in one embodiment, the trough is located below the machine framework 24 . In this manner, any water that is collected from the sleeve 26 and the sleeve grooves 26 a may be captured and discarded from the process.
[0017] The invention may be incorporated into any paper making process that produces paperboard, linerboard, and/or any other sheet products produced from cellulose fibers that are formed into a fiber mat. The process includes depositing an aqueous slurry of cellulose fiber containing various additives from a head box onto a fabric screen to form a cellulose fiber mat. Water is extracted from the slurry via vacuum boxes positioned below the fabric screen leaving a fiber mat or fiber sheet of cellulose fibers on the fabric. Paper making machines having a press roll system often include more than one pair of nip rolls. After forming, the fiber mat or sheet is then transferred to a continuous press felt. The felt and the mat are run through the press roll system to a first pair of nip rolls. The nip rolls are also referred to as a top press roll and a bottom press roll. As mentioned previously, the press roll system can include a plurality of pairs of nip rolls. Water is further extracted from the fiber mat or sheet as it passes between the pairs of top and bottom press rolls. The present invention can be incorporated into any one top or bottom press roll or both and in one or more pairs of press rolls in the press roll system. Any roll that is provided with a surface patterned sleeve can be modified to incorporate the wiper blade in accordance with the present invention. The water is removed from the fiber mat or sheet by the wiper blade assembly in accordance with the invention, thus producing a fiber mat of reduced water content before further processing, meaning less water than would ordinarily be expected will need to be evaporated from the fiber mat or sheet.
[0018] While the preferred embodiment of the invention has been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. For example, one of ordinary skill will recognize that, alternatively or in addition, a grooved sleeve can be mounted on the bottom press roll. A wiper blade constructed in accordance with the present invention can be positioned to contact such a sleeve upstream from the nip and remove water from the sleeve so positioned.
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A blade ( 20 ) for wiping water from a grooved sleeve ( 26 ) mounted on a press roll ( 14 ) in a paper making machine is adjustably mounted on the machine for movement toward and away from the sleeve ( 26 ). The wiper blade ( 20 ) is positionable against the surface of the sleeve ( 26 ) to wipe water therefrom adjacent and upstream from the nip between the sleeve ( 26 ) and a mating press roll ( 12 ).
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TECHNICAL FIELD
The present invention relates to an apparatus for routing power and inserting fiber optic cabling for a photonic local area network in a residential or a business neighborhood.
BACKGROUND OF THE INVENTION
Conventionally, electrical power service cabling and communications service cabling--such as cable and telephone communications--have been physically separate because of electrical noise interference on communications and safety concerns with exposure to high power transmission cabling. Conventionally, power and communications cabling were also separate installations because different providers provided the installation.
Fiber-optic cable has been available and has a non-conductive capacity in which electric or magnetic fields do not affect transmission of optical waveforms through the optic cable. Thus the conventional constraint of mixing communications cables with power cables due to electronic or "white noise" concerns was resolved. Examples of power cables incorporating fiber optic cables is illustrated in U.S. Pat. Nos. 5,274,725 and 5,495,546 issued to Bottoms et al., which discloses an embedded fiber optic cables within ground conductors used in high voltage power line architectures.
Conventionally, new neighborhood developments have utility connections such as electrical power, telephone PSTN copper twisted pair, cable television coaxial cable. Each service is trenched by separate installation contractors and owned by individual business entities, adding to the complexity and overall cost. Conventionally, primary power in new developments is distributed to local transformers in a parallel fashion. From the transformers the wiring is installed in a star topology to each individual home or business. Conventionally, communications companies form their own communications distribution overlay. In total, power and communications installation for a development require five trenching installations.
Furthermore, service company monitoring of a customers use was limited and control is maintenance intensive. For example, power service companies would have field technicians read power meters. These readings would then be compiled to provide a customer their billing.
Thus, to reduce costs and complexities in construction and installation, an integrated power and communications distribution unit for selective distribution and data acquisition for providing power and communications services to a set of residential or business buildings is desired. It is also desired that the integrated power and communications unit have a large data rate for accommodating video, audio and high bandwidth data.
From the foregoing discussion, it can be appreciated that a need exists for a simplified neighborhood transmission system that is safe and has a large data rate for accommodating video, audio and high bandwidth data with mixed synchronous, asynchronous, unidirectional and bidirectional transmission formats that is integrated within the community and the power distribution system.
SUMMARY OF THE INVENTION
Provided is an apparatus for distributing and controlling distribution of externally and locally generated communications signals to and between a plurality of subscribers.
A photonic distribution apparatus for a home area network having a plurality of subscribers has an optical transmission medium for conveying a communications data signal containing a plurality of distribution instruction segments, a microcontroller circuit, and a communications routing circuit. The optical transmission medium has at least one transmit and one receive pathway. The communications routing circuit responsive to a distribution instruction from the microcontroller circuit. The routing circuit has a plurality of fiberoptic switches in fiberoptic communication with one another, wherein a first fiberoptic switch of the plurality of fiberoptic switches has an input terminal photonically connected to said one receive pathway, and a last fiberoptic switch of the plurality of fiberoptic switches has an output terminal photonically connected to said transmit pathway.
In another aspect, the photonic distribution apparatus has a second optical transmission medium having at least one transmit and one receive pathway. The second optical transmission medium is for redundantly conveying the communications data signal containing a plurality of distribution instruction segments. A second communications routing circuit is responsive to the distribution instruction from the microcontroller circuit. The second routing circuit has a second plurality of fiberoptic switches in fiberoptic communication with one another, wherein a first fiberoptic switch of the second plurality of fiberoptic switches has an input terminal photonically connected to said one receive pathway, and a last fiberoptic switch of the plurality of fiberoptic switches has an output terminal photonically connected to said transmit pathway.
In a further aspect, the optical transmission mediums are embedded in an electrical cable having a plurality of electrical power conductors.
In yet another aspect, the invention has a high-voltage enclosure, and a low-voltage enclosure, the microcontroller circuit and the communications routing circuit being contained in the low-voltage enclosure. A high-voltage transformer contained within said high-voltage enclosure, said transformer electrically connected to said plurality of electrical power conductors of said electrical cable and said first and second optical transmission mediums photonically.
These and other features and advantages of the present invention will be apparent to those skilled in the art upon reading the following detailed description of preferred embodiments and referring to the drawing.
DESCRIPTION OF THE DRAWING
The accompanying drawings are incorporated into and form a part of the specification to illustrate several examples of the present invention. The drawings together with the description serve to explain the principles of the invention. The drawings are not necessarily to scale and the proportions of certain parts may have been exaggerated to better illustrate details and features of the invention. The drawings are only for the purpose of illustrating preferred and alternative examples of how the invention can be made and used and is not to be construed as limiting the invention to only the illustrated and described examples. The various advantages and features of the present invention will be apparent from a consideration of the drawings in which:
FIG. 1 is a schematic of a power/communications distribution of the present invention;
FIG. 2 is a schematic of a photonic distribution unit of the present invention;
FIG. 3 is a power/communication network implemented with a plurality of photonic distribution units;
FIG. 4 is a schematic of a station module of the present invention; and
FIG. 5 is a power/communication network implemented with a first and a second head-end unit.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The present inventions will be described by referring to drawings showing and describing examples of how the inventions can be made and used. In these drawings the same reference characters are used throughout the several views to indicate like or corresponding parts.
Referring to FIG. 1, shown is an integrated communication and power distribution unit 100. Distribution unit 100 has a conventional ground-mounted electrical power transformer portion 200 and an optical communications portion 300.
Power transformer portion 200 has a high voltage enclosure 202. Contained within the high voltage enclosure 202 is a conventional power transformer 204 for converting high voltage power to household needs.
Electrically connected to power transformer 200 through high-voltage enclosure 202 are two integrated three-phase power/optic-fiber cables 206 and 208, respectively, such as those disclosed in U.S. Pat. No. 5,274,725, issued Dec. 28, 1993, to Jack Bottoms, Jr., et al., wherein the fiber-optic cables are embedded within the conductors of the primary voltage feed lines or ground lines. It should also be noted that separate fiber optic cable can be layered in the trench at the time of power cable installation, as is known in the industry.
Input cable 206 provides power input with power cables 206a, 206b, and 206c, accordingly, from a power line or other ground transformer. Also input into distribution unit 100 are transmit and receive optic-fiber cables 206d and 206e. Output cable 208 provides a link for connection to another distribution units or for closing the distribution path by terminating a head end used for home area networks. Output cable 208 has corresponding power cables 208a, 208b and 208c for the power phases and transmit and receive optic-fiber cables 208d and 208e. It should be noted that the transmit and receive cables can be combined into a unitary fiber-optic cable implementing bi-directional signaling techniques, as is well known in the industry.
The optic-fiber cables 206d, 206e, 208d, and 208e can route integrated communications data signals. As an example, an integrated signal can contain data from an external communications data network that has a plurality of asynchronous and synchronous user data bandwidth segments or channels. These channels contain television programming data, direct space TV data (Ka Band, C-Band, and S-Band), audio programming data and telephony service data, including PSTN, from back-haul service providers or world wide communications networks. The telephony service data can be external to the resulting network or between network subscribers (FIG. 3). As the term is used herein, a "subscriber" is either a residential or business location that can subscribe to use the power and data provided by the integrated distribution unit 100. These communications signals are typically multiplexed together at a communications head-end for transmission over the optic-fibers. Optical frequencies provide wide signal bandwidths greater than or equal to 1 GHz. Such bandwidth capacity, for example, allows distribution of at least two-hundred television channels. The bandwidth simultaneously allows telephony and personal computer transmissions, compressed video conferencing and other data transmissions.
The high-voltage enclosure 202 and the low-voltage communications enclosure 302 are isolated from each other by bulk-head 304. Extending therethrough are a plurality of voltage isolation connectors 306. Through the isolation connectors 306, distribution input fiber-optic cables 206d and 206e are photonically connected to photonic distribution unit 300 at input photonic connector 308. Photonic pathways can be in free-space transmissions form or in wave-guide (fiberoptic) forms. A suitable isolation connector is an SC duplex adapter available from Amp, Inc. Similarly, distribution output fiber-optic cables 208d and 208e are photonically connected to photonic distribution unit 300 at output photonic connector 310.
Photonic distribution unit 300 has an optical switch assembly 312 and switch control circuit 314. Control circuit 314 demultiplexes controller commands sent from a community head-end station 104 for performing self-test functions, service hookup and discontinuance, as well as fault isolation. Similarly a holding voltage or digital command from the premises equipment may automatically initiate isolation upon premises equipment failure. Subscriber fiberoptic cables 336 extend from photonic distribution unit 300 through voltage isolation connectors 306 in bulkhead 304. The number of fiberoptic cables 336 number from 1 through n-1, where n is the number of subscriber nodes for providing power/communications services. Subscriber fiberoptic cables 336 are recombined with subscriber power cables 210, and extend from high-voltage enclosure 202. The integrated power/communications cables are installed, typically underground, to a subscriber node S 1 , S 2 , S 3 , S 4 through S n-1 .
Referring to FIG. 2, shown is a block schematic of control circuit 314 and switch assembly 312. Switch assembly has a plurality of two-by-two Multimode Fiberoptic Switches 316. Multimode fiberoptic switches are fully reversing optical bypass switches used to insert or bypass stations in fiber ring networks. In response to node, individual switch, failures, the switch reverts to the bypass state, thereby preserving network integrity. A suitable multimode fiberoptic switch is disclosed in U.S Pat. No. 4,834,488, issued May 30, 1989, to Ho-Shang Lee, the specification of which is incorporated by reference herein. A commercial embodiment of a multimode fiberoptic switch is available from DiCon Fiberoptics, Inc., of Berkeley, Calif. Switches 316 are electrically-driven solenoid-actuated optical switches. Each switch has an "IN" terminal 326, an "OUT" terminal 328, a "Rx" or receive terminal 330, and a "Tx" or transmit terminal 332. It should be noted that as technology evolves, semiconductor-actuated switches can be used in place of these solenoid-actuated optical switches.
Also, fiber optic switches 316 isolate failed subscriber equipment or set-top boxes because service is not provided to that premises. Isolation control can be accomplished through a holding voltage or command instruction from a community centralized head-end controller. For a series connected local area network ("LAN") type system, such isolation capability is important for maintaining system reliability. Alternative architectures could be used within the communications enclosure.
Plurality of switches 316 are arranged in a primary channel A and secondary channel B fiber optic loops 318a and 318b, respectively. Each group of two-by-two switches 316 (e.g., SW1A and SW1B) are electrically connected in parallel, which provides a network controller the capability to either selectively isolate or connect individual subscribers to the communications network. For example, optical switches SW1A and SW1B provide communications services to one subscriber. Thus, in the preferred embodiment, each subscriber has four fiberoptic cables going to it, providing an incoming data entrance 330a, an incoming data exit 332a, an outgoing data entrance 330b and an outgoing data exit 332b. The embodiment illustrated in FIG. 2 provides communications connections for at least ten subscribers S 1 through S 10 . The fiberoptic cables are combined with household power lines 210 and subscriber fiberoptic cables, shown in FIG. 1, to limit installation expenses. It is believed that in the future only two primary optical fibers would be needed for the subscriber connections for two-directional communications, allowing termination of dark or un-powered fibers in the enclosure 100 for future subscriber uses.
Switch control circuit 314 is photonically connected to transmit and receive fiberoptic cables 208d and 208e, respectively, through channel A fiberoptic loop 318a. Switch control circuit preferably has a microcontroller, which is generally a one-chip integrated system typically having a peripheral features such as program and data memory, ports, and related sub-systems. A microprocessor can be used, but such devices are used to drive general-purpose computers. Switch control circuit 314 is also photonically connected to transmit and receive fiberoptic cables 206d and 206e, respectively, through channel B fiberoptic loop 318b. As shown in FIG. 2, circuit 318a allows parallel control for redundancy. These signal transmissions are converted from the optical propagation mode to the electrical propagation mode through optical receivers or detectors 320a and 320b, as is well known in the industry. Combined within the data signal are digital data segments or instructions segments that are assigned to the switch controller 322. The digital data segments are extracted with detection firmware modules 324a and 324b, respectively. The remaining signal data flow is reconverted to an optical propagation signal mode through optical transmitters or laser diodes 32 and the signal stream in input into the optical switch assembly.
Referring to FIG. 3, shown is a spoked-type network configuration with integrated communication/power distribution units 100, 100' and 100" distributing household power and communications data to subscribers S 1 through S 4 , S 1 ', through S 4 ', and S 1 " through S 4 ", respectively. More distribution units 100 can be similarly employed to provide network capabilities to a larger geographic area or larger subscription need. For clarity, the cables are set out by their base number. For example, cable 206 is understood to have cable components 206a, 206b, 206c, 206d, and 206e.
Referring to FIG. 3, shown is a serial interconnect for a electrical power transformer for a plurality of subscribers. As the term is used herein, a "subscriber" is either a residential or business location seeking to use the power and data provided by the integrated unit 100. In this case there is a A circuit and a B circuit 19. The optical circuits can be multi-mode or single-mode functionality.
At the subscriber residence, the subscriber has a distribution device with a combined fiber/power panel architecture and a conventional breaker power panel. An example of a distribution device is provided by the set-top box or station module disclosed in U.S. application Ser. No. 08/607,964, filed Feb. 29, 1996, entitled "Photonic Home Area Network," pending, incorporated by reference herein. The distribution device provides two-way communications connections for the home or business. Telephony connections would be category-3 or category-5 multi-pair cable looped through the subscriber's domain for individual-line data accumulation. Multi-output coaxial cable television channel connections are also provided from the distribution device.
In FIG. 4, shown is an illustration of a set-top box or station module 400, which has linear bidirectional link ("LBL") with demultiplexing and data extraction from a downstream channel and data insertion into an upstream channel. The LBL is formed through photonically connecting receive terminals 404 and 406 to photonic distribution unit 300 through transmit terminals 332a and 332b, respectively, and photonically connecting transmit terminals 402 and 408 to receive terminals 330b and 330a, respectively. LBL terminals 402 and 404 define an "upstream" or receive pathway data flow. LBL terminals 404 and 408 define a "downstream" or transmit pathway data flow. The photonic signals are converted into electrical representations or vice versa through optical detectors or receivers 410.
Data insertion can be accomplished through insertion module 412 with synchronous demultiplexing and re-multiplexing using high-speed demultiplexer and multiplexer integrated circuits capable of at least a 1.5 Giga-bits-per-second data rate time-division multiplexing ("TDM"). A suitable demultiplexer is a Fiber Channel Standard demultiplexer, such as a HDMP1014. A suitable multiplexer is also a Fiber Channel Standard multiplexer such as a HDMP1012, both available from Hewlett-Packard. The inserted data is then channeled through a gated-multiplexer 414 for insertion into the upstream data flow. Alternative SONET standard chip-sets can also be used, with minor data rate and configuration changes. Other forms of suitable data insertion are implemented by synchronous-labeled multiplexing wherein a station module detects an end-of-message ("EOM") code at the end of a data stream and appends the insertion data onto the end of the last message packet, or an asynchronous transmission burst within prescribed time slots having a synchronization preamble for each upstream burst Data extraction is similarly accomplished through extraction module 416.
The extracted data is delivered to various units or ports such as a television, telephone or the like. Telephony or other such data is conveyed through insertion module 412 for integration into the upstream data flow through gated-multiplexer 414. The user data streams are 62.5 Megabits-per-second (Mbps) channel, but can be increased to two or three similar channels as the demands of the users increases. The user data bit stream is dynamically allocated by the head-end 104. As an example, about 2 Mbps to about 5 Mbps of the data frame can be allocated toward telephone conversations. Specific telephone conversations starting will be allocated to a position in the data frame at the start of the telephone call by the head-end 104 and that position in the data frame would remain allocated until that telephone call is terminated.
User data, conveyed through data lines 418 and 420, consists of telephony, personal computer data, auxiliary data for home maintenance and control, fire and intrusion alarm, etc. Futuristic home video conferencing equipment allowing total office immersion of stay-at-home workers could be supported. The bandwidth availability can readily accommodate data transmissions common today. For example, telephone service can be accomplished to about 500 subscribers with less than 3 Mbps. However, bandwidth hungry technologies such as real-time video conferencing, can require throughputs approaching a magnitude of Giga-bits-per-second. An initial allocation of 125 Mbps for the residences in the network is sufficient for future bandwidth needs in the near future. As is known in the industry, the communications interface electronics in the subscriber residence will vary depending upon system data format.
Referring to FIG. 5, shown is a linear topology that has one or more head-ends 104a and 104b. This particular topology uses the downstream path for distribution of the incoming head-end signals and the upstream path for accumulation of the outgoing head-end signals. Two head-ends topology accounts for signal-point failure auto-correction. Auto-correction is achieved by reversing the data flow in one side of each part of the broken segment of the network.
The description and figures of the specific examples above do not point out what an infringement of this invention would be, but are to provide at least one explanation of how to make and use the invention. Numerous modifications and variations of the preferred embodiments can be made without departing from the scope and spirit of the invention. Thus, the limits of the invention and the bounds of the patent protection are measured by and defined in the following claims.
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Provided is an apparatus for distributing and controlling distribution of externally and locally generated communications signals to and between a plurality of subscribers. A photonic distribution apparatus for a home area network having a plurality of subscribers has an optical transmission medium for conveying a communications data signal containing a plurality of distribution instruction segments, a microcontroller circuit, and a communications routing circuit. The optical transmission medium has at least one transmit and one receive pathway. The communications routing circuit responsive to a distribution instruction from the microcontroller circuit. The routing circuit has a plurality of fiberoptic switches in fiberoptic communication with one another, wherein a first fiberoptic switch of the plurality of fiberoptic switches has an input terminal photonically connected to said one receive pathway, and a last fiberoptic switch of the plurality of fiberoptic switches has an output terminal photonically connected to said transmit pathway.
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FIELD OF THE INVENTION
The present invention relates to the general field of firearms and is particularly concerned with a firing nipple for muzzle loading firearm.
BACKGROUND OF THE INVENTION
Muzzle loading firearms which were once considered the ultimate weapon have been used increasingly in recent years both in tournaments and for hunting. Indeed, in some regions regulations allow for a extended hunting season for users of muzzle loading firearms since such their use allows the game to escape more easily.
Most muzzle loading firearms now use a so-called percussion type firing system instead of the so-called flintlock method which was prevalent up until the 19 th century. Conventional percussion type firing systems including a percussive firing cap and a nipple communicating with the firearm ignition chamber.
Conventional percussion caps are typically made out of a thin soft metal formed into a substantially cap shape. The percussion cap is provided with a relatively thin coating of priming compound on the inside of its flat surface of the closed portion of the cap. For the priming compound to ignite it must be compressed between two surfaces. During use, the percussion cap is placed on the nipple so that when the hammer strikes the cap the priming compound is compressed between the hammer and the nipple which thus acts as an anvil. Compression of the priming compound between the hammer and the nipple ignites the priming compound. This produces a predetermined quantity of burning gas in the nipple. The gas in the nipple is forced under considerable pressure into the ignition chamber of the firearm igniting the propellant charge therein. The firing cap naturally needs to fit snugly over the nipple in a position to be struck by the firearm's hammer.
The ignition assembly of most percussion type muzzle loading firearms further includes a breech plug mounted within the breech of the firearm. Typically the breech plug is screwed into the breech. The breech plug may be provided with a threaded nipple bore for threadably receiving the firing nipple.
Heretofore, nipples usable in conjunction with percussion caps to ignite the propellant charge in a firearm have included an elongated body having a passage extending longitudinally therethrough. Such passage generally includes a cylindrical primary chamber communicating with the cap receiving end of the nipple. This primary chamber serves as an explosion chamber for the percussion cap. The passage also includes a relatively small bore constriction chamber communicating with the gas discharge end of the nipple. This constriction chamber serves to restrict flow of particles out of the primary chamber whereby a high gas pressure within the primary chamber occurs at the time of the percussion explosion.
The prior art discloses various modifications of firing nipples. However, prior art constructions suffer from at least one major drawback. Indeed, misfiring of muzzle loading firearms utilizing a percussion cap and a percussion nipple has proven to be a common problem. The chance of misfiring would be lessened considerably by using a more powerful percussion or potent percussion cap. However, the use of a more powerful percussion cap would increase the risk of so-called blow back of the discharge from the percussion cap. Blow back occurs when the heated gases from the detonated firing cap blow back in the direction of the cap. It can be easily understood that such blow back adversely affect ignition efficiency and may even potentially present a danger to the firearm user. Such blow back effect may also occur from heated gases upon ignition of the propellant charge within the firearm ignition chamber, again diminishing the firearm performance and creating potential danger to the firearm user.
In order to reduce the amount of misfiring, improved firing caps have been developed. For example, the so-called 209 type of fire cap has proven to be more reliable.
Accordingly, there exists a need for an improved firing nipple for muzzle loading firearms.
SUMMARY OF THE INVENTION
According to one aspect of the present invention, there is provided a firing nipple for a muzzle loading firearm comprising a body portion having an inlet end and an outlet end, an exterior wall comprised of a first exterior wall section, a second exterior wall section and a third exterior wall section, the first exterior wall section being situated proximate the inlet end, the third exterior wall section being situated proximate the outlet end and the second exterior wall section being situated intermediate the first and third exterior wall sections, the first exterior wall section having a greater diameter than a diameter of the second exterior wall section to thereby form a first exterior abutment shoulder therebetween,
the second exterior wall section diameter being greater than a diameter of the third exterior wall section to thereby form a second exterior abutment shoulder therebetween, an interior wall comprised of a first interior wall section, a second interior wall section and a third interior wall section, the first interior wall section being situated proximate the inlet end and defining a first chamber, the third interior wall section being situated proximate the outlet end and defining a third chamber, and the second interior wall section being located between the first interior wall section and the third interior wall section and defining a second chamber, the second interior wall section having an interior diameter less than a diameter of the first interior wall section to thereby form a first interior abutment shoulder therebetween, the second interior wall section interior diameter being less than a diameter of the third interior wall section, and an inwardly tapering wall section extending between the second interior wall section and the third interior wall section.
Advantages of the present invention include that the proposed firing nipple is specifically adapted to be used with relatively high performance percussion caps in muzzle loading firearms thus reducing the risks of misfiring.
The proposed firing nipple is specifically configured so as to provide easy and stable mounting of the percussion cap thereon. The firing nipple is provided with a built-in means for ensuring stable and safe support of the percussion cap.
The configuration of the passage formed in the firing nipple is optimized to increase the igniting capacity of the percussion cap. Furthermore, the firing nipple is provided with built-in means for reducing the risk of blow back both from the percussion cap and the propellant charge in the firearm.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view illustrating a firing nipple for muzzle loading firearms in accordance with an embodiment of the present invention;
FIG. 2 is an end view of the firing nipple shown in FIG. 1 as seen from the left hand side thereof;
FIG. 3 is a top view of the firing nipple shown in FIG. 1;
FIG. 4 is a side view of the firing nipple shown in FIG. 1;
FIG. 5 is a longitudinal cross sectional view of the firing nipple shown in FIG. 1;
FIG. 6 is a partial longitudinal cross sectional view illustrating the firing nipple of FIG. 1 threadably mounted to a breech plug, the breech plug being screwed into the breech of a firearm; and
FIG. 7 is a partial longitudinal cross section of a conventional breech plug.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring initially to FIG. 6, there is shown a portion of a firearm employing a percussion cap firing system for igniting a propellant charge within the firearm. The percussion cap firing system includes a nipple 10 in accordance with one embodiment of the present invention and which is adapted to be threadably mounted to a breech plug 12 . Breech plug 12 is, in turn, threadably mounted to the barrel 14 of a firearm. The barrel 14 is typically made out of a single piece of cast and machined steel defining a breech 16 therein. The rearward section of the breech 16 adjacent the breech plug 12 defines a powder chamber section 18 for receiving a propellant charge such as a gun powder 20 packed thereinto.
Referring now to FIGS. 1 to 5 , there is shown in greater detail the configuration of the nipple 10 . The nipple 10 has a generally elongated body defining a first or proximal end 22 and a longitudinally opposed second or distal end 24 . The nipple 10 is provided with a longitudinal channel extending therethrough and which will be discussed in greater detail hereinbelow.
The external opposed longitudinal ends 22 , 24 respectively have corresponding planer faces 26 and 28 which occupy substantially parallel geometrical planes. The nipple 10 defines a proximal annular rim section 30 intercepting the face 26 . The annular rim section 30 is provided with two notches 32 formed radially therein. The notches 32 are configured and sized for receiving the blade of a conventional screwdriver or other tool adapted to facilitate rotation of the nipple 10 about its longitudinal axis.
The external configuration of the nipple 10 also defines an annular groove 34 positioned adjacent the annular rim section 30 . The annular groove 34 is configured and sized for receiving a biasing means for concentrically biasing the body of the nipple 10 in the region of the groove 34 towards a smaller radius. In a preferred embodiment of the invention, the biasing means takes the form of a wire spring 36 . Both the rim section 30 and the annular groove 34 are provided with a slot 38 intercepting at least a portion thereof. The slot 38 is adapted to slidably receive a locking end section 40 of the spring 36 .
The external configuration of the nipple 10 further defines a first exterior wall section 42 and an adjacent second exterior wall section 44 . The first exterior wall section 42 has an external diameter somewhat larger than that of the second exterior wall section 44 so that both the first and second exterior wall sections 42 and 44 define a first exterior abutment shoulder or surface 46 therebetween. As shown in FIG. 6, the first and second exterior wall sections 42 and 44 are configured and sized so that the first abutment shoulder 46 will matingly abut against an exterior shoulder or surface 48 of the breech plug 12 .
The external configuration of the nipple 10 still further includes an exterior wall spacing section 50 . The spacing section 50 has an external diameter somewhat smaller than that of the second exterior wall section 44 so that the spacing section 50 and the second exterior wall section 44 together define a second exterior abutment shoulder or surface 52 therebetween. The spacing section 50 and the second exterior wall section 44 are configured and sized so that the second abutment shoulder 52 matingly and sealingly abuts against a breech plug proximal internal shoulder 51 . Also, the external diameter of the spacing section 50 is smaller preventing obstruction or interference.
The external configuration of the nipple 10 still further includes a mounting section 58 provided with an external thread 60 . The external thread 60 is adapted to cooperate with the internal thread formed in the internal connecting channel 56 part of the breech plug 12 . The mounting section 58 of the nipple 10 includes an outlet section 62 having an external diameter smaller than the threaded portion of the mounting section 58 . The outlet section 62 and the rest of mounting section 58 thus define yet a third exterior abutment shoulder or surface 64 therebetween. The third exterior abutment shoulder 64 is configured and sized for matingly and sealingly abutting against a second internal shoulder 68 part of the breech plug 12 . The length of the outlet section 62 is preferably sized so that the distal end 24 is positioned substantially adjacent a conically divergent wall 70 which forms part the breech plug 12 . Typically, for Remington type and other firearms a spacing channel 72 extends between the internal threads 56 and the divergent wall 70 of breech plug 12 . Outlet section 62 is thus adapted to extend at least partially through the internal spacing section 72 of the breech plug 12 for reasons which will be hereinafter disclosed.
In a preferred embodiment, the external diameter of the rim 30 and the first intermediate section 42 has a value substantially in the range of between 0.425″ and 0.445″, the external diameter of the second intermediate section 44 preferably has a value substantially in the range of between 0.32″ and 0.34″ and the external diameter of both spacing section 50 and outlet section 62 having a value substantially in the range of between 0.2″ and 0.21″. Typically, the nipple 10 has an overall length substantially in the range of between 0.875″ and 0.975″ with the length between the second abutment shoulder 52 and the second end 28 being substantially in the range of between 0.4″ and 0.43″. The length between the first and second abutment shoulders 46 and 52 is preferably substantially in the range of between 0.15″ and 0.17″ with a length between first end 26 and first abutment shoulder 46 being substantially in the range of between 0.33″ and 0.37″ while the annular groove 34 preferably has a thickness in the range of between 0.07″ and 0.09″.
Turning now more specifically to FIG. 5, there is shown in greater detail the configuration of an internal longitudinal channel 74 . Channel 74 includes a first large chamber section 76 defined by interior wall 75 and which is configured and sized for receiving an ignition cap. The first chamber section 76 extends into a second chamber 78 defined by interior wall section 79 . An internal shoulder 80 is defined between the first chamber section 76 for abuttingly contacting the distal end of the cap. The second chamber 78 preferably has a generally cylindrical configuration that tapers conically at a distal end thereof into an intermediate section 82 . The cone shaped intermediate section is defined by a conical wall disposed at an angle substantially in the range between 117° and 119° relative to the longitudinal axis of the nipple. The second chamber 78 extends integrally into a smaller diameter third chamber 84 defined by interior wall section 85 . Joined passage sections 82 and 84 define a funnel shaped chamber.
In operation, the nipple 10 is threadably attached to the breech plug 12 . The ready the firearm for firing, the propellant charge such a gunpowder 20 is packed into the powder chamber 18 and a percussion cap 78 is slidably introduced into the first chamber section 76 . The cap is releasably attached to the nipple 10 using the spring type component 36 mounted in the annular slot 74 with the locking segment 40 extending through the slot 38 .
The cap contains the usual internal explosive charge. A hammer type component, when released by a suitable trigger, strikes the cap exploding its charge. The exploding particles initially extend into the second chamber 78 and are momentarily contained therein under high pressure. The high pressure forces, the heated bases and particles through the tapered conical wall section 82 , into the outlet chamber 84 and thence, into the firing chamber 18 . The heated gases and particles then ignite the propellant charge in the firearm. The sudden rush of hot explosive gases rapidly flowing to or out of the ignition port provide a simultaneous expulsion of the bullet from the gun muzzle.
As mentioned previously, the proposed invention is adapted to reduce the risk of blow back. The gas blow back is at least partially related to the fact that at the instant of cap firing, heated gas particles fill the primary chamber creating an intense pressure therein for a brief period. If not quickly released into the main firing chamber the pressurized particles of gas will blow back against the cap. Secondly, following ignition of the firearm propellant charge, a portion of the gasses and particles form that charge are forced back inside the nipple creating further blow back. From the foregoing, it can be appreciated how the present invention in nipple design substantially reduces blow back. Firstly, the first chamber 76 is solidly created with minimal apertures extending threrethrough and is designed so as to reduce the formation of the cap upon ignition of the latter. The only aperture extending through the first chamber 76 retaining the cap consists of the slot 38 used for maintaining the cap within the chamber 76 .
The design of the second chamber 78 is also adapted to extend the periods during which the cap combustion products are contained therein. This extended period of time allow more product of ignition to reach the propellant and allows them to achieve the transfer over an extended period of time. The ignition material is thus allowed to reach a higher ignition temperature within the chamber 78 which will, in turn, result in a higher reliability of ignition of the powder 20 .
The angular relationship of the cone shaped wall 82 with the longitudinal axis of the nipple 10 allows for a better gas outlet which reduces the risks of blow back within the nipple. This risk is further reduced by the use of a single outlet.
The risk of blow back is still further reduced by the use of at least two and preferably three abutment shoulders 46 , 52 and 64 which sealingly abut against corresponding surfaces of the breech plug 12 for preventing blow back towards the cap 78 . In order to allow for unobstructed abutment of the shoulders 46 , 52 and 64 against corresponding abutment surfaces of the breech plug 12 , the spacing section 50 is undersized relative to the external diameter of the threaded channel 56 part of the breech plug 12 . Also, the external thread 60 part of the mounting section 58 is given a thread step substantially in the range of 273 to 274 thousands of an inch in order to increase resistance to pressure forces created by the ignition.
Furthermore, the outlet section 62 allows the ignition gases to reach directly the divergent cone shaped wall 70 part of the breech plug 12 . Typically, the divergent wall 70 has an angle substantially in the range of 100° relative to the longitudinal axis of the breech 12 plug which allows the ignition gases to reach a wider initial surface of powder 20 . The powder 20 thus ignites more rapidly which, in turn, again reduces the risk of misfiring.
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A firing nipple for a muzzle loading firearm where there are provided a plurality of exterior wall sections of differing diameters to provide abutment shoulders to sealingly engage against surfaces on a breech plug, and an internal chamber having a tapering wall to direct the hot gasses. The arrangement substantially prevents blow back and provides for an increased efficiency in the firing of a weapon.
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CROSS-REFERENCES TO RELATED APPLICATIONS
The present invention is a continuation-in-part of U.S. patent application Ser. No. 08/223,989, filed Apr. 6, 1994, now U.S. Pat. No. 5,482,100, issued Jan. 9, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to the art of spring motors useful for a variety of applications, including venetian blinds and window shades. More specifically the present invention relates to a system in which lifting cords and cord locking mechanisms are eliminated from shades or blinds. Still more specifically, the invention relates to window covering systems which employ one or more constant or consistent, variable force springs to balance the weight of accumulated window covering material, depending upon the extent to which the blind or shade is raised or lowered. The present invention also relates to motorized blinds and shades.
2. Description of the Prior Art
Venetian blinds have been known for many years and typically include a plurality of slats made from metal, plastic, wood or other materials and supported by ladders. Such blinds typically include a bottom bar and a tilt mechanism to cause the slats to move from a horizontal position to a nearly vertical position to open and close the blinds with respect to the passage of light. It is also conventional with such systems to use lifting cords coupled to the bottom bar, passing through the slats and into mechanisms within the blind headrail. The cord is used to raise the bottom bar, accumulating individual slats as the bar is raised. Because of the natural tendency of the bar and accumulated slat weight to free fall, locking mechanisms are also commonly employed with such prior art devices. Pleated and other types of shades also include a bottom bar and similar raising, lowering, and cord locking mechanisms.
Several attempts have been made to eliminate the lifting cord locks, some of such attempts going back nearly 140 years. See, for example, Bixler, U.S. Pat. No. 13,251, issued Jul. 17, 1855 for "Inside Blinds." In this device, a pair of "fusees" are employed, namely spirally grooved pulleys, to wind a cord passing therebetween. The two fusees are arranged so that as a barrel spring is being wound the cord joining the fusees compensates for changes in spring force. A spool is provided for accumulation of the lifting cord.
U.S. Pat. No. 2,420,301, issued May 13, 1947 to Cusumano for "Venetian Blind" also employs a cone-shaped member with grooves and an elongate coil spring. This design dispenses with normal draw cords and provides a counterbalance so that the slats may be retained at any vertical position without a lock or anchorage and so that the blinds can be raised with relatively small effort.
A different device is shown in Pratt's U.S. Pat. No. 2,324,536 issued Jul. 20, 1943 for "Closure Structure." In this device, tapes and coil springs are employed to raise and lower a blind particularly suited for use in a vehicle such as a train. The complex structure disclosed in this patent is especially suitable for devices in which the bottom bar and the slats ride in tracks as they move upwardly and downwardly.
Other patents show various spring devices used with venetian blinds. For example, in Cohn's U.S. Pat. No. 2,390,826, issued Dec. 11, 1945 for "Cordless Venetian Blinds," two coil springs are used to provide even force, with a centrifugal pawl stop. The blind is raised by freeing the pawl to allow the spring to provide a lift assist. Other more conventional systems employing springs and ratchet and pawl mechanisms include those shown in Etten's U.S. Pat. No. 2,824,608, issued Feb. 25, 1958 for "Venetian Blind"; U.S. Pat. No. 2,266,160, issued Dec. 16, 1941 to Burns for "Spring Actuated Blind"; and U.S. Pat. No. 2,276,716, issued Mar. 17, 1942 to Cardona for "Venetian Blind."
Various attempts have also been made in the prior art to motorize blinds and shades. In most of these systems hard wiring is required because larger motors are required to move the bottom rail and accumulated window material.
None of the aforementioned patents disclose the use of spring motors of the type disclosed herein to eliminate the conventional pull cords and locks of venetian blinds or shades in a simple and easily adaptable mechanism having few components parts. A system which overcomes the disadvantages of the more complex and cumbersome systems of the prior art would represent a significant advance in this art.
SUMMARY OF THE INVENTION
The present invention features a cordless blind or shade in which a spring motor is used to eliminate conventional pull cord and cord-lock mechanisms.
The present invention also features a system in which either the spring strength or the number of spring motors may be altered, depending upon the size of the window covering. The invention further features techniques for increasing the friction on the cords used to raise and lower the blinds or shade to assist in maintaining a desired position against any spring force which may exist through the range of travel of the bottom bar.
The present invention still further features a system which is easy to adapt to a wide variety of blind or shade designs and sizes and the capability of applying spring forces in a variety of ways and combinations.
A different feature of the present invention is the use of spring motors and small electric motors to provide highly desirable automatic or remote controlled capabilities for shades and blinds.
How the present invention accomplishes these features will be described in the following detailed description of the most preferred embodiments, taken in conjunction with the FIGURES which illustrate blind systems, although shade applications are also enhanced by the present invention. Generally, however, the features are accomplished by employing constant force or consistent variable force spring motors in a blind or shade system, while eliminating conventional pull cord and associated cord-lock mechanisms. The features are accomplished by using springs wound on drums, the springs being of constant cross-section (constant force) or varying in width, thickness, or both along their length (variable force) whereby spring force imparted to a coiled spring is transferred from one drum to another. For these spring motors, such force is at its highest level when the blind or shade is fully raised, i.e., when the cords are supporting the full weight of the window covering. The spring force is at its lowest point when the window covering is fully lowered and, in the case of blinds, the slats are being individually supported by ladders, rather than by the cords, leaving only the bottom bar to be supported by the cord. In constant force systems, the spring force is substantially constant throughout the range of movement of its shade or blind bottom rack. The blinds and shades of the present invention may be manipulated by the operator simply grasping the bottom bar and urging it in an upward or downward direction.
The features of the present invention are also accomplished by providing selection criteria for the springs, to take into account the size and weight of a particular blind or shade or by adding additional spring motors for heavier or wider window coverings. To achieve greater certainty in maintaining desirable spring forces, in a most preferred, alternate form of the invention, the spring motors are interconnected to ensure that they operate in unison to provide a level action throughout the range of blind or shade travel. All of these features are accomplished in a blind or shade which will remain in the position selected by the user and which in a preferred embodiment may be motorized, e.g. by a small remote controlled DC motor. In an illustrated embodiment, friction imparting devices are, if necessary, used with the cords coupling the bottom bar and a spool within the headrail.
Other features of the invention, and other ways in which those features are accomplished, will become apparent to those skilled in the art after the detailed description of the most preferred embodiment is read and understood. Such other ways are deemed to fall within the scope of the invention.
DESCRIPTION OF THE DRAWINGS
FIG. 1A is a perspective view of a spring storage drum useful in one preferred form of the present invention;
FIG. 1B is a perspective view of output drum, combined with a cord spool, useful in this preferred form of the present invention;
FIG. 2 is a schematic view of a spring motor together with one form of friction imparting device;
FIG. 3 is a schematic illustration of a combination of three spring motors, with the cord spools coupled together to ensure that all motors operate in unison;
FIG. 4A is a perspective view of a strip of spring material varying in width along its length;
FIG. 4B is a schematic view of the spring shown in FIG. 4A wound into a coil;
FIG. 5A is a schematic view of a spring varying in thickness along its length;
FIG. 5B is a view of the spring of FIG. 5A shown in a coiled position;
FIG. 6 is a schematic representation of a blind in the fully open position with the cord storage drum fully wound and a spring wound on its storage drum, the system thereby supporting the full weight of the slats and bottom bar;
FIG. 7 is a schematic illustration of the blind shown in FIG. 6, with the bottom bar in its fully lowered position and illustrating how the storage drum for the cords is substantially empty and the spring substantially transferred from its storage drum to its associated output drum; and
FIG. 8A is a perspective view of a strip of spring material being generally uniform in cross section along its length,
FIG. 8B is a schematic view of the spring shown in FIG. 8A wound into a coil; and
FIG. 9 is a view, similar to FIG. 6, but showing in schematic form a motor system for raising and lowering the blind.
In the various FIGURES, like reference numerals are used to indicate like components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before proceeding with the detailed description of the preferred embodiments, several comments should be made about the applicability and the scope of the present invention. First, while venetian-type blinds are shown in certain of the FIGURES, the types of materials from which the blinds are made or the relative widths, heights and the configuration of the headrail, bottom rail and slats may vary widely. The present invention has applicability to a variety of such blinds. The present invention is also useful with window shades of various types since many shade designs also use lifting cords and would benefit from the features of this invention. Whenever blinds are mentioned herein, shades should be considered a suitable alternative.
Second, while preferred types of springs are shown, one varying in width, another varying in thickness and a third being of constant cross-section, a combination of the three could be employed. Other spring configurations could also be used, in addition to those having a rectangular cross-section. For example, springs with round or oval cross-sections, decreasing along its length (for a variable force spring) or a laminated spring could also be employed.
Third, while one example is given of how to interconnect a plurality of spring motors, other techniques can be employed. For example, a gear system can be employed instead of the illustrated bar. The object of illustrative FIG. 3 is to show how the spring motors can be made to operate in unison for level raising or lowering of the blind or shade, even if the lifting forces are applied off center. Ideally, however, the user should be instructed to apply the lifting or lowering force at, or relatively near, the center of the bottom rail to maintain desirable balance and to prevent slack from being created in the lifting cords.
Proceeding now to a description of the FIGURES, FIG. 1 is a perspective view of one storage drum 10 useful in the preferred embodiment. Storage drum 10 includes an axial hole 12, a cylindrically-shaped spring storage area 14, and a pair of walls 16 and 18 which taper upwardly and outwardly from area 14. This particular storage drum is especially suitable for a spring which varies in width, as will be described later in this specification. Drum 10 will be referred to herein as a storage drum, i.e. the drum on which the spring is initially coiled. The drum 10 would have parallel walls 16 and 18 for other embodiments such as for the springs illustrated in FIGS. 5A, 5B, 8A, and 8B.
Proceeding next to FIG. 1B, an output drum is shown generally at 20 to include an axial hole 22, a cylindrical body 24, and a pair of walls 26 and 28. A hole 29 is provided on body portion 24, the purpose of which will become apparent shortly. Output drum 20 also includes a cord spool 30 having a central aperture (not shown) coaxial with hole 22, a body portion 32, and a pair of parallel side walls 34 and 36 defining an area therebetween for storage of the lifting cords.
Proceeding next to FIG. 2, the arrangement of the devices in FIGS. 1A and 1B in a spring motor unit 40 is shown. Motor unit 40 includes a bracket having a planar back wall 42 onto which the storage drum 10 and output drum 20 are rotatably mounted in a spaced apart orientation. Axles 43 and 44 pass respectively through the apertures 12 and 22 of the drums 10 and 20. From FIG. 2, it will be appreciated that output drum 20 is located adjacent wall 42, with the cord spool 30 located outwardly therefrom.
A spring is illustrated at 45 and is coupled between storage drum 10 and output drum 20. The spring itself will be described later. The spring motor unit 40 also includes a pair of surfaces 46 and 47, which are parallel to one another and perpendicular to surface 42, defining a generally U-shaped enclosure for the two drums and the cord spool. A hole 49 is provided in surface 46 and a hole 50 is provided in surface 47, with lifting cords 52 shown passing through each toward the cord spool 30. The illustrated motor unit 40 also includes another bracket component 55 spaced apart from surface 47 and including a plurality of slots 56 in its upper edge. Solid and dashed lines illustrate how the slots 56 may be used to increase the tension on the cord 52 traveling through portion 47 toward cord spool 30.
Finally, two attachment areas 57 and 59 are shown in FIG. 2, with holes 58 and 60, respectively. The latter are used for attachment of the bracket to the blind head bracket. Obviously, the location of the mounting holes can vary widely, depending on the overall configuration of the blind with which the spring force motor unit 40 is to be used.
Before proceeding to more detailed descriptions of the springs 45, reference should now be made to FIG. 3, showing schematically how a plurality of spring motor units 40 may be coupled together, e.g. by an elongate bar 62 rotatably coupled to each of the respective cord spools 30 (or by gearing on the drums 10 and 20, not shown). It will be appreciated from this drawing, which is from a reverse perspective compared to that shown in FIG. 2, that the three spring motor units 40 will work in unison and the bar 62 will compensate for minor variations in spring forces which may exist for the individual springs 45 and ensure an even winding of the cords 52, even if the force to raise or lower the blind is applied off-center.
Proceeding next to the descriptions of FIGS. 4A and 4B, a preferred spring 70 is shown, again in perspective form. Spring 70 includes a first narrower end 72, a second wider end 74 and a coupling extension 75 having a hole 76 therein. The illustrated spring has a constant thickness. Spring 70, in use, is wound onto the storage drum in the configuration illustrated in FIG. 4B, i.e. with its narrower end coupled to body portion 14, and its wider end toward the outside. The extension 75 is attached to the body portion 24 of output drum 20 using hole 76 and any suitable fastener. The spring is wound from one drum to the other in an opposite coil orientation. In other words, as spring 70 is transferred from the storage drum 10 to the output drum 20, the width of the spring 70 between the two drums will decrease and the spring will be wound oppositely to its original coil shape.
Another embodiment of a spring useful in the invention is shown in FIGS. 5A and 5B, i.e. a spring 80 having a varying thickness. Spring 80 has a thinner first end 82, a thicker second end 89 having a width equal to that of end 82, and a coupling extension 85 having a hole 86 therein. The preferred coil orientation for spring 80 is shown in FIG. 5B, this time with the thinner end 82 at the core of the storage drum 10 and the thicker end 89 extending onto and around the output drum 20, using coupling extension 85 and hole 86. Again, the orientation of the spring, as it is transferred from the storage drum 10 to the output drum 20, is reversed.
While it has been mentioned earlier that springs of different configurations may be employed for variable force spring motors, it will now be more fully appreciated that one variation would be to use a spring which varies both in width and thickness. Also, a coil spring of circular cross-section or a laminated spring could be employed. The cross-section increasing from the end attached to the storage drum 10 to the end attached to the output drum 20.
Proceeding now to FIG. 6, the use of a spring motor unit 40 for a blind system 90 is shown. Blind system 90 includes a bottom bar 92, a headrail 94, and a plurality of slats 95 located therebetween. The ladders are not illustrated in these FIGURES but are conventional and, in and of themselves, do not form part of the present invention. The cords for raising and lowering bottom bar 94 are illustrated at 96 and 97 and are shown extending through the slats and toward the cord spool 30, which will be fully wound with cord when the blind is in the position illustrated in FIG. 6. Moreover, the storage drum would be wound with most of spring 45 and the output drum would be wound only to the extent desirable to attach its end and to provide the desired holding force.
Referring now to FIG. 7, the bottom bar 92 is shown in its fully lowered position with the individual slats 95 spaced from one another and with the cords 96 and 97 unwound from cord spool 30. At this point, the slats would be individually suspended from ladders (not shown) attached to the headrail 94, so that their weight is not being carried by the spring motor unit 40. It can be observed that the spring 45 has been substantially transferred from the storage drum 10 to the output drum 20, thereby decreasing the amount of force exerted on the bottom bar. In an ideal situation, the spring force will be just sufficient to prevent bottom bar 92 from self-raising.
When it is desired to open blind system 90, the bottom bar 92 is urged toward headrail 94, resulting in a spring driven rotation of the cord spool to wind cords 96 and 97. The spring will rewind back to storage drum 10, with an ever increasing level of force as the weight of the bottom bar 92 and accumulating slats 95 continues to increase. The operation is completed when the FIG. 6 configuration is achieved.
While the present invention has been described in connection with several illustrated embodiments, further variations may now be apparent. For example, instead of using only two cords (illustrated as 96 and 97 in FIGS. 6-7), additional cords could be used for wider blinds, as required.
In connection with experiments done to date, one suitable spring is made from Type 301 High-Yield Stainless Steel and has a length of 87 inches and a constant thickness of 0.005 inches. Its width increased from 0.110 inches at its narrow end to 0.312 inches at its wide end. For a coil diameter of 0.540 inches, a theoretical maximum torque of 0.650 pounds per inch was created, and the theoretical torque minimum was 0.230 pounds per inch.
In another example, a spring strip of the same length and material varied in thickness from 0.0029 inches to 0.0054 inches with the same coil diameter. The theoretical maximum torque was 0.819 pounds per inch, while the torque at the bottom (minimum) is reduced to 0.140 pounds per inch. It can be seen from these examples that the spring motor provides a variable force which is consistent in application, depending upon the particular position of the bottom rail or member with respect to the headrail. The theoretical forces may be readily calculated using formulas which are available from spring manufacturers in which the output force is determined by the formula: ##EQU1## where: F=Output force
E=Modulus of elasticity
b=Width of spring strip
s=Thickness of spring strip
r=Constant coil radius.
It then becomes apparent that as the width or thickness varies from end to end of the strip, so also will the resultant force.
FIGS. 8A and 8B show yet another embodiment of the present invention, this time where the spring 45 is a constant cross-section spring 110 having a first end 112, a second end 114, an extension 115 extending from the second end, and a hole 116 in the extension. The coiled form of spring 110 is shown in FIG. 8B.
It has been found that in some applications, for example applications where the blinds are short, or are made from very light materials, or where friction imparting devices are used with the cords that a constant force spring may be entirely suitable. This is true because while the weight exerted on the lifting cords 96 and 97 will vary as the blind is raised and lowered, frictional forces are present which can be sufficient to maintain the shade in any desired position without free fall. This particular embodiment could be enhanced using the friction imparting devices discussed in connection with FIG. 2. Accordingly, it can be readily seen that the present invention has extremely wide application and that the designer may make numerous choices depending upon the particular size of the blind, its construction materials, etc.
As with the other embodiments, several spring motors employing springs 110 can be coupled together, e.g. as is shown in FIG. 3. Alternatively, a plurality of such motors may be used which are not interconnected to one another.
FIG. 9 is a view, similar to FIG. 6, showing in schematic form a motor system for raising and lowering a blind. In order to facilitate understanding of the invention, like elements will be identified by like reference numerals in FIG. 9 and FIG. 6. Accordingly, in FIG. 9, a blind system 90 is illustrated having a spring motor unit 40 and cords 96,97 for raising and lowering bottom bar 92.
Also shown in FIG. 9 are a drive motor 130, and a control unit 132 for controlling operation of drive motor 130. Drive motor 130 is preferably an electrical motor which can drive in two directions and is operatively coupled with spring motor unit 40 by a coupling 131 to apply a drive force in either of two directions to move bottom bar 92 up or down. It is advantageous to use both spring motor unit 40 and drive motor 130 so that the force applied to blind system 90 by spring motor unit 40 augments and assists drive motor 130. Drive motor 130 may be operatively coupled anywhere in the driving mechanism of blind system 90. By such an arrangement a smaller, cheaper, and more energy-efficient drive motor 130 may be more advantageously employed with blind system 90 than could be employed alone without spring motor unit 40.
Control commands may be provided to control unit 132 for controlling operation of drive motor 130 from a remote position by hard-wired connection (not shown in FIG. 9) to a remote control unit such as remote control unit 134. In the alternative, remote control unit 134 may wirelessly communicate with control unit 132 by any of several methods, such as sonic coded signal patterns or optic coded signal patterns. The coding patterns may be coded transmission patterns, or coded frequency patterns, or combinations of such patterns.
In environments where there are a plurality of blind systems 90 which should be individually wirelessly controllable by one or more remote control units 134, respective blind systems 90 must be individually addressable. The required distinction among such a plurality of blind systems 90 may be encoded in each respective control unit 132 and recognized by remote control unit(s) 134 in any of several manners. For example, respective control units 132 may be user-coded by individual digital switches to assign a user-determined code to each respective blind system 90. Further, similar coding may be effected by embedding code in a read only memory (ROM) in each respective control unit 132, or by programming a code into a random access memory (RAM) in each control unit 132. A pin grid array or a jumper wire arrangement would also accomplish the desired coding, but such arrangements are susceptible to error and occupy large amounts of space.
Remote control unit 134 may similarly be encoded to selectively address a particular blind system 90: digital switch coding, ROM, RAM, and jumper-wiring may all be appropriate. Yet another approach involves factory preprogramming of systems. For example, a factory-provided library of codes may be programmed into a ROM in a remote control unit 134. A user may select a code from the library of codes for assignment to a respective blind system 90 by any of the above-described encoding mechanisms: e.g., digital switches, RAM, or the like. The user-selection may involve merely a two-digit entry or selection to identify an eight-digit (for example) digital code. By such an arrangement, the security of eight-digit coding and its protection against inadvertent operation of blinds is achieved with significantly less opportunity for errors in user-coding since the user needs only to enter two digits to identify/encode a particular blind system 90.
So while the invention has been described in connection with certain illustrative examples, it is not to be limited thereby but is to be limited solely by the scope of the claims which follow.
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A cordless, balanced venetian blind or shade with a constant, or a variable force spring motor includes conventional window covering components without the outside hanging lifting cords or cord locking mechanisms. One or more spring motors are employed. A cord spool, in the preferred embodiment, is coupled to one of the spring drums to serve to wind the cords to cause the blind to be raised or lowered, simply by manipulation of the bottom bar of the blind system. Due to the spring forces, the system compensates for the increasing weight on the cords as the window covering is raised and for the decreasing weight as it is lowered.
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FIELD OF THE INVENTION
This invention relates to a device for detecting the loss of tension of a warp yarn in a weaving loom.
BACKGROUND OF THE INVENTION
In a conventional weaving loom an operator has to find a heddle to which an abnormal warp belongs by pushing a plurality of heddles aside. It usually takes a long time to find it because the operator has to find it by guess of the place where the abnormal warp is or by a clue of waste of yarn coming out of the loom. Therefore finding a heddle to which an abnormal warp belongs is really troublesome, especially in a dobby which has many heddle frames.
SUMMARY OF THE INVENTION
The present invention has been proposed to facilitate a detection of a heddle to which an abnormal warp belongs. When a warp is broken or loosened a signal representative of loss of tension of warp is transmitted from detection means disposed on a heddle frame to which the warp belongs and a lamp corresponding to the heddle frame glows by a signal through a lamp illuminating circuit. The detection means can be divided into more than two portions in a heddle frame so that a plurality of lamps corresponding to the portions are provided for displaying an approximate place of a heddle to which an abnormal warp belongs.
It is a primary object of the present invention to provide a device, for displaying the loss of tension of a warp, which indicates a heddle frame or a portion in a heddle frame to which the abnormal warp belongs by illuminating at least a lamp among a plurality of lamps corresponding to each heddle frame or the portion respectively.
It is another object of the present invention to provide a device for displaying the loss of tension of a warp which facilitate the detection of a heddle to which an abnormal warp yarn belongs.
It is a further object of the present invention to provide such a device in which a lamp maintains glowing until a lamp illuminating circuit is reset.
BRIEF DESCRIPTION OF THE DRAWINGS
Other features, objects and advantages of the present invention will be more apparent as the description of the preferred embodiment proceeds taken in conjunction with the appended drawings in which:
FIG. 1 shows a partly perspective view of a first preferred embodiment of a device for detecting the loss of tension of a warp yarn according to the present invention;
FIG. 2 is a sectional view of the heddle bar shown in FIG. 1 taken along the line II-II';
FIG. 3 shows a lamp illuminating circuitry which may by adapted to the first preferred embodiment;
FIG. 4 shows a partly perspective view of a second embodiment of a device for detecting the loss of tension of a warp yarn according to the present invention;
FIG. 5A is a sectional view of the heddle bar shown in FIG. 4 taken along the line V-V';
FIG. 5B is an enlarged sectional view of the heddle bar around a sharp projection mounted on the heddle bar shown in FIG. 5A taken along the line VB-VB';
FIG. 6A shows a partly perspective view of a third embodiment of a device for detecting the loss of tension of a warp yarn according to the present invention;
FIG. 6B is a sectional view of the heddle bar shown in FIG. 6A taken along the line VIB-VIB';
FIG. 7 shows a lamp illuminating circuitry which may be adapted to the third embodiment;
FIG. 8A shows a schematic view of a fourth embodiment of a device for detecting the loss of tension of a warp yarn according to the present invention;
FIG. 8B is a sectional view of the heddle bar shown in FIG. 8A taken along the line VIII-VIII';
FIG. 8C is an enlarged view of the heddle bar shown in FIG. 8A around one of the sharp triangle insulating projections.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Reference is now made to FIG. 1 which shows first preferred embodiment according to the present invention. Though each heddle frame 1, 1' includes a pair of heddle bars only the heddle bars 2, 2' disposed on the upper portions are shown in the figure. A plurality of one group of heddles 3 made of wires are movably attached by loops 4 to the heddle bar 2 and the other group of heddles 3' to the other bar 2' by loops 4'. Each heddle 3, 3' has its eye of a needle for supporting a warp yarn. In the operation of the loom, especially in shedding, heddle bars 2, 2' and other heddle bars on the opposite side which are not shown move reciprocatively and alternately raising and lowering the two groups of warp yarns 5, 5' via heddles 3, 3'. As shown in FIG. 1, when the heddle bar 2' is at an upper portion pulling and thus raising a plurality of heddles 3', the loops 4' are fully pulled respectively downward because of the tension along the warps 5'. On the other hand when the heddle bar 2 is at an lower portion, the top portion of each loop 4 has a space with respect to the upper portion of the heddle bar 2 because heddles 3 receive upward force by way of tension along the warps 5.
The heddle bars 2, 2' are made of electro-conductive material and at its one end of each heddle bars 2, 2' are disposed electrodes 6A, 6'A respectively while another electrodes, 7A, 7'A are disposed via an insulating member 9A on the body (no numeral) of the loom to contact the electrodes 6A, 6'A respectively when the heddle frame 1 or 1' moves downward. Thus the combination of electrodes 6A and 7A and also the combination of electrodes 6'A and 7'A form a pair of first electric switches 8A, 8'A respectively for detecting the lower position in the movement of the heddle frame 1, 1' i.e. heddle bars 2, 2'.
The electrodes 7A, 7'A disposed on the insulating member 9A which is fixedly connected to the body are further arranged to be reciprocatively movable by means of springs 11A, 11'A for absorbing the pressure which may be produced by the fluctuation of the strokes of the movement of the heddle frames 1, 1'.
Reference is now made to FIG. 2 which shows a sectional view of the heddle bar 2 and the relation between the heddle bar 2 and a loop 4X which hangs over the top portion of the same. An elongate electrode 10A is disposed via an insulating member 13 longitudinally along the entire top portion of the heddle bar 2. The electrode 10A is arranged to contact with the loop 4X when the loop 4X hangs over the heddle 2. All the loops 4 including the loop 4X shown in FIGS. 1 and 2, are made of electro-conductive material and conductive with the heddle bars 2, 2' at their either side. Consequently, the electrode 10A and the top portion of the loop 4X constitute a second electric switch 14A.
Switches 8A and 14A are connected in series as shown in FIG. 1, by a chain line L, and this arrangement is made for each heddle frame. With this construction, during the first switch 8A closes i.e. during the heddle bar 2 is at its lower position, if in operation, all the warps are in normal condition the heddles 3 are biased upwardly by the tension of warps. Since the upper portion of each loop 4 is spaced from the upper surface of the heddle bar 2, the second switch 14A does not close. If a warp 5X is in abnormal condition such as being broken or loosen, as shown in FIG. 1, the tension along the warp 5X disappears and the heddle 3X which keeps the warp 5X falls down by its self-weight. At this instant a loop 4X which is corresponding to the heddle 3X fell on the upper surface of the heddle bar 2 thereby the second switch 14A closes.
When both of the first and second switches 8A, 14A close simultaneously, terminals TA-1, TA-2 become conductive and a signal for stopping the operation of the loom is generated in a circuit which is not shown. The first embodiment according to the present invention is provided to generate a signal for illuminating a lamp corresponding to a heddle frame to which an abnormal warp belongs by using a signal obtained though the switches 8A, 14A.
Referring now to FIG. 3 which shows a lamp illuminating circuitry for lighting lamps, the circuitry comprises a illuminating signal generating circuitry S and a display circuitry W. Switches shown in FIG. 1 and 2 are also shown in the illuminating signal generating circuitry for convenience. The construction of the circuitries S, W is designed to apply for a loom having four heddle frames. However, the circuitries may be designed to adapt to looms having more heddle frames. Switching circuits S 1 to S 4 are corresponding to each heddle frame respectively where all the switching circuits S 1 to S 4 are connected at its one end with a node P which is always fed with a logic signal "1", the logic signal is produced by a logic signal generator which is not shown. The construction and the function of the switching circuits S 1 to S 4 are same therefore the description of the switching circuits is made only for the switching circuit S 1 which corresponds to the heddle frame 1 i.e. to heddle bar 2. The first switch 8A and the second switch 14A are connected in series where the first switch is also connected to the node P at the other terminal TA-1 thereof. An inverter 15A is interposed between the terminal TA-2 of the switch 14A and an input 16-2 of a first NAND gate 16A. An output (no numeral) of the first NAND gate 16A is coupled to an input 17-1 of a second NAND gate 17A and an output of the second NAND gate is connected to an input 16-1, which is different from the above-mentioned input 16-2, of the first NAND gate 16A. The other input 17-2 of the second NAND gate 17A is connected to a reset circuit R which comprises a reset switch 18 one of the terminal of which is coupled to the node P. The other terminal of the reset switch 18 is connected not only to the input 17-2 of the second NAND gate 17A but also to one of two inputs of other second NAND gates of the switching circuits S 2 to S 4 . The reset switch 18 is a press-to-open type (normally close type) switch therefore the both terminals of the reset switch 18 is closed unless the switch 18 is pressed. The display circuitry W includes four display circuits denoted by W 1 to W.sub. 4, where each circuit corresponds respectively to the switching circuits S 1 to S 4 mentioned above. Since the display circuits W 1 to W 4 are the same in construction and the function, the description is made only for the display circuit W 1 . A resistor 20A is inserted between a positive terminal of a power supply (not shown but denoted by (+)) and an anode of a LED (light emitting diode) 21A. The cathode of the LED 21A is coupled to a collector of a transistor 19A the emitter of which is connected to a negative or ground terminal denoted by (-) of the power supply. A base of the transistor 19A is connected via a resistor 22A to the output of the first NAND gate 16A. Other display circuits W 2 to W 4 are arranged in the same manner where each base of each transistor is connected to an output terminal of a first NAND gate (no numeral) of each switching circuit S 2 to S 4 respectively.
Now the description of the operation of the lamp illuminating circuitry S, W is made. At the beginning the lamp illuminating circuitry becomes operable after the reset switch 18 is pressed instantaneously. By opening the reset switch 18 the input 17-2 of the second NAND gate 17A is fed with logic "0" signal so that the second NAND gate 17A produces logic "1" signal at its output irrespectively of the state of the other input 17-1 of the same. The logic "1" signal at the output 17-2 is applied to the input 16-1 of the first NAND gate 16A. When warps belonging to the heddle frame which corresponds to the first and second switches 8A, 14A are normal to the logic "1" signal at the node P is not supplied to the invertor 15 because the second switch 14A is in open state even while the first switch 8A is closed. Therefore the input 16-2 of the first NAND gate 16A is supplied with a logic "1" signal by the inverter 15A. In response to the logic "1" signals at both inputs 16-1, 16-2 the first NAND gate 16A produces a logic "0" signal at its output. Since the LED 21A is designed to emit light by the current through the collector and the emitter of the transistor 19A, the LED 21A does not emit light while a logic "0" signal is fed via the resistor 22A to the base of the transistor 19A. It is apparent that if all the warps of the loom are in normal condition, viz. with certain tension, none of the LEDs of the display circuitry W emits light.
When the reset switch 18 closes again after an instantaneous opening of the same, the input 17-2 of the second NAND gate 17A is again fed with a logic "1" signal. However, since the other input terminal of the same is fed with the logic "0" signal as described hereinbefore the output of the second NAND gate 17A is still at logic "1" which is the same state as before the reset switch 18 is closed again. Consequently, the output of the first NAND gate 16A maintains the logic "0" signal irrelevant to the state of the reset switch 18 after the first opening of the same.
If in operation, a warp 5X belonging to the heddle frame 1 is abnormal as shown in FIG. 1, the second switch 14A contineously closes and at the lower position of the heddle frame 1 the first switch 8A also closes. In this case the inverter 15A produces logic "0" signal in response to the logic "1" signal fed via the first and second switches 8A and 14A from the node P to the input. With this logic "0" signal the first NAND gate 16A produces a logic "1" signal at its output irrelevant to the state of the other input 16-2 of the same. The logic "1" signal produced by the first NAND gate is then fed via the resistor 22A to the base of the first transistor 19A to drive the same and thus make the first LED 21A emit light. The output of the first NAND gate 16A is also supplied to the input 17-1 of the second NAND gate 17A while the other input 17-2 of the same is fed via the reset switch 18 with logic "1" signal. Because the both input terminals 17-1, 17-2 are supplied with logic "1" signal respectively the second NAND gate 17A produces logic "0" signal at its output which is fed to the input 16-1 of the first NAND gate 16A and thus the first NAND gate 16A maintains to produce logic "1" signal irrespective to the logic value of the other input 17-2. Namely, even after the switch 8A opens, the first NAND gate 16A keeps producing logic "1" signal for driving the corresponding transistor 19A and thus LED 21A maintains emitting light untill the reset switch 18 is pressed to open the same.
If the reset switch 18 is opened the input 17-2 of the second NAND gate 17A is fed with logic "0" signal so that the second NAND gate 17A produces logic "1" signal which is fed to the input 16-1 of the first NAND gate 16A. Then the first NAND gate 16A produces logic "0" signal at its output which does not drive the transistor 19A and thus the LED 21A any more. It is to be noted that the combination of a pair of NAND gates 16A, 17A is provided to constitute a holding circuit. This circuit may be substituted with other holding circuit.
Reference is now made to FIGS. 4, 5A and 5B which show the second embodiment according to the present invention. In this embodiment both sides of the heddle frame 1, 1' are shown where the same arrangement of switches 8A, 8'A and 8B, 8'B are arranged symmetrically. Same numerals are used for the corresponding elements as the first embodiment shown in FIG. 1. The heddle bars 2, 2' have sharp triangle insulating projections 12, 12' respectively at midway of the entire length. FIG. 5A is a sectional view of the heddle bar 2 taken along the line V-V' shown in FIG. 4 and FIG. 5B shows a further sectional view of the enlarged portion of the heddle bar 2 around the insulating projection 12 taken along the line VB-VB' of FIG. 5A. The insulating projection 12 is disposed on the upper portion of the heddle bar 2 and the bottom end of the insulating projection 12 is fixedly incorporated with a recess (no numeral) of the heddle bar 2. The shape of the insulating projection 12 is upwardly so sharp that the loop 4 loosely attached besides the same slides down to the top surface of the heddle bar 2 along the either sides of the insulating projection 12 when not only the heddle frame 1 is raised but also a loop 4X hangs over the insulating porjection 12 by its weight when a corresponding warp is abnormal in case of the lower position of the heddle bar 2. Two elongate electrodes 10A, 10B are longitudinally positioned via an insulating member 13 on the top surface of the heddle bar 2 as shown in FIGS. 4, 5A and 5B. Electrodes 10A, 10B are electrically insulated by the insulating projection 12 and constitute switches 14A, 14B respectively. A pair of contacts 6A, 6B of switches 8A, 8B are disposed on the both sides of the heddle bar 2 where the construction of the switches is the same as the one described in the first embodiment. Same arrangement is made to the other heddle bar 2' which includes a pair of electrodes 10'A, 10'B, an insulating projection 12' and a pair of contacts 6'A, 6'B of switches 8'A, 8'B.
The chain lines in FIG. 4 show the connection of the switches 8A, 14A and 8B, 14B to terminals TA-1, TA-2 and TB-1, TB-2. It is now clear that in this second embodiment, the construction is the same as the first embodiment except each heddle bar 2, 2' includes a pair of elongate electrodes 10A, 10B or 10'A, 10'B, an insulating projection 12 or 12' and a pair of contacts 6A, 6B or 6'A, 6'B of switches 8A, 8B or 8'A, 8'B.
The circuitry S, W for illuminating lamps shown in FIG. 3 may be used for this second embodiment. Turning back to the FIG. 3, the combinations of switches of each switching circuit S 1 to S 4 are respectively substituted with combinations of a pair of switches 8A and 14A, 8B and 14B, 8'A and 14'A, and 8'B and 14'B which are shown in FIG. 4. Operation and the function of the illuminating circuitry S, W are the same as the first embodiment and thus the description of the same is omitted.
Since the entire length of the heddle bars 2, 2' are electrically divided into two portions each LED shown in FIG. 3 corresponds to a half portion of a heddle bar respectively. The circuitry S, W shown in FIG. 3 can be adapted to a loom having two heddle frames but it is possible to increase the number of the switching circuits and display circuits as much as desired corresponding to the number of heddle frames. It is to be understood that since each heddle bar is electrically divided into two portions it is more convenient than the first embodiment to find an abnormal warp yarn when one of the LEDs lights. This means it takes approximately a half time for finding the abnormal warp for the operator compared to the first embodiment.
Reference is now made to FIGS. 6A and 6B which show the third embodiment according to the present invention. The entire length of the heddle bar 2 between switches 6A and 6B are electrically divided into three portions denoted by A, B, C and two independent elongate electrodes 10A, 10B are disposed via an insulating member 13 on the top surface of the heddle bar 2. These two electrodes are designed to be parallel at the portion B and connected respectively to terminals TA-2, TB-2 where the connection is shown by chain lines in FIG. 6A. As shown in FIG. 6B these electrodes 10A, 10B are insulated from each other by a insulating member 13 and also insulating from the heddle bar 2. Each loop has a downward bent portion at the top portion thereof to facilitate connecting the electrodes 10A and 10B effectively when the loop 4 hangs over the heddle bar 2 as shown in FIG. 6B. The electrodes 10A, 10B are connected respectively via the terminals TA-2, TB-2 to each corresponding lamp lighting circuit in the same manner as described hereinbefore and the circuitry for illuminating lamps shown in FIG. 3 may be adapted.
The operation of the third embodiment is as follows. When a loop 4X which belongs to the portion A or C of the heddle bar 2 hangs over the same, a LED corresponding to the portion A or C glows and when a loop 4X belongs to the portion B hangs over the heddle bar 2, both of the LEDs which respectively correspond to the portions A and C glow.
In the third embodiment, it will be understood that since the heddle bar 2 is electrically divided into three portions, it is more convenient to find an abnormal warp compared with other emdobiments described hereinbefore.
Referring now to FIG. 7 which shows a lamp illuminating circuitry S', W' which may be also adapted to the above-mentioned third embodiment, the lamp illuminating circuitry includes a illuminating signal generating circuitry S' and a display circuitry W'. Most of the arrangement is the same as the before-mentioned lamp illuminating circuitry S, W shown in FIG. 3 except that an AND gate 23 and a pair of EX (exclusive) OR gates 24A, 24B are provided. The circuitry shown in FIG. 7 is for only one heddle frame 1 and the other circuits for the other heddle frame is omitted from the figure since the construction is the same as the circuitry shown in the figure. When the lamp illuminating circuitry is adapted to a weaving loom having more than two heddle frames the number of circuits can be increased as much as desired corresponding to the number of heddle frames.
Each input of the AND gate 23 is coupled to the outputs of the first NAND gates 16A, 16B of each switching circuit S'1, S'2 respectively. Thus the AND gate 23 produces output logic signal when both outputs of the first NAND gates 16A, 16B are at logic value "1" i.e. when a loop 4X hangs over the both electrodes 10A, 10B in the portion B of the heddle bar 2 as shown in FIG. 6A, 6B. An input of the first EX OR gate 24A is also connected to the output of the first NAND gate 16A and the other input of the first EX OR gate 24A is connected to the output of the AND gate 23. An input of the second EX OR gate 24B is connected to the output of the first NAND gate 16B and the other input of the second EX OR gate is also connected to the output of the AND gate 23. The outputs of the first and second EX OR gates 24A, 24B are connected via resistors 22A, 22B to bases of first and second transistors 19A, 19B respectively and the output of the AND gate 23 is connected via resistor 22C to a base of a third transistor 19C. It will be appreciated that when switches 8A and 14A closes simultaneously the invertor 15A is fed with logic "1" signal and thus produces logic "0" signal at its output which is supplied to the first NAND gate 16A. Then the NAND gate 16A produces logic "1" signal at its output irrespectively to the logic value of the other input of the same, thereby the logic "1" signal is provided to the AND gate 23 and the EX OR gate 24A. The function of the switching circuit S 2 ' and other switching circuits which are not shown in the figure is the same as that of the circuit S 1 '. When a loop 4X hangs over the portion B of the heddle bar 2 shown in FIG. 6A both outputs of the first NAND gate 16A, 16B are at logic value "1" and the AND gate produces logic "1" signal to drive the transistor 19C and thus the LED 21C emits light therefrom. Since both inputs of each EX OR gate 24A, 24B are supplied with logic "1" signal, none of the EX OR gate generates logic "1" signal at its output and LED 21A and 21B thereby do not emit light. If the loop 4X hangs over the portion A shown in FIG. 6A, the output of the first NAND gate of the second switching circuit S'2 is at logic value "0" while the output of the first NAND gate 16A is at logic value "1" and thus the AND gate 23 does not drive the transistor 19C. The first EX OR gate 24A is fed with logic "1" and "0" signals respectively at its inputs thereby produces logic "1" signal to drive the transistor 19A i.e. the LED 21A while the second EX OR gate 24B generates logic "0" signal because of logic "0" input signals at both inputs.
Now it is apparent with this lamp illuminating circuitry S', W' shown in FIG. 7, a LED corresponding to each portion A, B or C emits light displaying the portion of the heddle 2 to which an abnormal warp yarn belongs.
Reference is now made to FIGS. 8A, 8B and 8C which show the fourth embodiment. The heddle bar 2 includes four portions A, B, C, D which are electrically independent as shown in FIG. 8A. There are disposed four elongate electrodes 10A, 10B, 10C, 10D via an insulating member 13 on the top surface of the heddle bar 2. Further the electrodes 10A to 10D are insulated each other not only by the insulating member 13 but also insulating projections 12AB, 12BC, 12CD. These insulating projections are such as those described in the second embodiment shown in FIGS. 4 and 5B. Since the construction of the heddle bar 2 with electrodes 10A to 10B is symmetrical the description of the right half portion of the heddle bar 2 shown in FIG. 8A is made. The electrode 10A is positioned above the half of the other electrode 10B in vertically parallel position as shown in FIGS. 8A, 8B, 8C and the rest of the electrode 10B is positioned co-axially with the other electrode 10A. The electrode 10B has a bent portion denoted by V beside the insulating projection 12AB as shown in FIG. 8C. With this arrangement the heddle bar 2 has four electrically independent portions.
Each electrode 10A to 10D is connected at its one end to terminals TA-2, TB-2, TC-2, TD-2 respectively as shown in FIG. 8A to be connected to a lamp illuminating circuitry. The same lamp illuminating circuitry S, W as the first embodiment shown in FIG. 3 may be adapted. Since the operation of the circuitry is described hereinbefore it is omitted. It is now apparent that a LED which corresponds to one of the portions of the heddle bar 2 emits light when a loop 4X hangs over the portion. Since the circuitry shown in FIG. 3 includes only four switching circuits S 1 to S 4 and displaying circuits W 1 to W 4 this circuitry may be adapted to only one heddle bar of one heddle frame. Therefore the number of switching circuits and displaying circuits may be increased corresponding to the number of heddle frames so as to facilitate the operator of the loom to find a place to which a loop i.e. a heddle which supports an abnormal warp yarn belongs with much less time.
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At least one elongate electrode is positioned on the upper surface of an upper heddle bar of each heddle frame of a loom for constituting a switch with loops loosely coupled to the upper heddle bar, each loop being spaced from the upper surface of the upper heddle bar at the lower position of the heddle bar due to upward force along the heddle produced by the tension of a warp, the switch being closed when a loop hangs over the electrode by its self weight due to loss of tension along the warp at the lower position of the heddle bar, the lower position of each heddle bar being detected by a heddle bar position detector, a corresponding LED being illuminated by a display circuitry connected to the switch and the heddle bar position detector, the circuitry including holding circuits for maintaining the illumination of the LED from the first glowing until the holding circuit is reset.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a U.S. national stage application of International Application No. PCT/FI01/00791, filed Sep. 12, 2001, and claims priority on Finnish Application No. 20002031, filed Sep. 14, 2000, the disclosure of each application is hereby incorporated by reference herein.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED RESEARCH AND DEVELOPMENT
Not applicable.
BACKGROUND OF THE INVENTION
The invention concerns a method and equipment for pulp fractionation in a paper machine or such, such as a board machine.
Multi-layer headboxes are already in use with many board grades and they are also on their way to printing paper machines. Layering has traditionally been done by layering the supply of either filler or retention agents. It is a weakness of this system that the pulp itself is entirely similar in all layers, so the drainability, fibre content and quantities of fines in the layers are not different. This of course limits the efficiency of layering.
Alternatively with e.g. tissue or board machines the different raw material components, such as short and long fibre, are treated separately from each other all the way from pulp treatment to the headbox. In such a system a double pulp system must of course be built all the way from pulp treatment to the paper machine.
Fractionation plants are used also in the production of pulp. Pressurized screens are generally used in the fractionation, and the fractionation is performed already at the pulp plant. In this case too a double pulp system must be built for the paper machine.
SUMMARY OF THE INVENTION
In the system according to the invention, the pulp is brought mixed into the short circulation of the paper machine. For example, in a machine using 100% recycled fibre, there is only one raw material, whereby pulp layering without fractionation cannot be done at all.
The centrifugal cleaners traditionally used in the short circulation of the paper machine have been used only to separate sand. The centrifugal cleaner installation separates pulp e.g. according to its density, size, shape and surface roughness. In the system according to the invention, the fractionation done by centrifugal cleaners is utilised in such a way that the accept of a certain centrifugal cleaner is conducted into a certain bypass manifold of the multi-layer headbox to form a certain web layer. In the system according to the invention, the fractionation ability of centrifugal cleaners is utilised e.g. in such a way that the fraction having more fines or long fibres is guided into the bottom and/or surface layer of the headbox.
In the first step of centrifugal cleaning, the pulp is divided roughly in a suitable proportion between the various layers. The final fine control of proportioning takes place only at the pump of the headbox. Surplus of pulp is circulated back to the input of the centrifugal cleaner.
Compared with filler layering, the quality of the pulp itself in the various layers can also be varied, and desired fibre fractions can be guided either to the surface or into the middle layer as required.
There is no need for any separate pulp systems before the centrifugal cleaners, but all pulp is brought in only one line all the way to the short circulation.
The equipment already in the short circulation is utilised and there is no need for any new partial processes. Only the operation of step 1 of the centrifugal cleaning is changed in such a way that the so-called reject ratio will correspond with the quantity of fibres needed in the various layers.
According to the invention, the pulp is conducted from the wire pit to the centrifugal cleaner, and from the first stage, that is, from step 1 , of the centrifugal cleaner installation the pulp is conducted forward, in one embodiment of the invention into a deaeration tank, the reject of step 1 is conducted further into the second stage of the centrifugal cleaner installation and thence the accept is conducted forward into the second part of the deaeration tank.
An advantageous embodiment of the invention is as follows. The accept arrived from the first stage of centrifugal cleaning into the deaeration tank is conducted from the deaeration tank into the part of the headbox forming the bottom and surface layers of the web, preferably through power screens. The pulp conducted as accept from the second stage, that is, from step 2 , of the centrifugal cleaner into the deaeration tank is conducted through a power screen located in between the deaeration tank and the headbox into the bypass manifold of the headbox, through which bypass manifold the pulp is conducted on to the formation wire to form the middle layer of the web.
Thus, in fractionation according to the invention, the centrifugal cleaner installation is utilised and the fractionation is carried out from various stages of the centrifugal cleaner installation in such a way that the pulp conducted from the first stage into the deaeration tank is conducted further after deaeration to form top layers of the web, and the pulp conducted as accept from the second stage or from other stages is moved further from the concerned stage/stages of the centrifugal cleaner installation to form other layers of the web, such as the middle layer of the three-layer web. However, it is not a purpose to limit the invention to the manner of forming a three-layer web described above. With the equipment according to the invention it is also possible to form two-layer paper to paper or board grades having even more layers instead of three-layer paper.
The system thus utilises a centrifugal cleaner installation and its fractionation in the making of multi-layer paper. The system may be applied to such short circulation already in use, which include a centrifugal cleaner. One stock is conducted into short circulation and it is treated in such a way in the centrifugal cleaner installation that the desired fraction can be conducted further through a deaeration tank to the multi-layer headbox into the pulp bypass manifold corresponding with each layer. In the system according to the invention, a power screen may also be used in between the deaeration tank and the headbox in order to achieve the final fractionation result. Such an embodiment is also possible within the scope of the invention, where there is no deaeration from the pulp. In a system where there is no deaeration from the pulp, the accepts of centrifugal cleaning may be taken directly to the suction side of the headbox's feed pump. In other respects the structure of the system is similar to the one in the embodiment shown in FIG. 1 .
Such an embodiment may also be possible within the scope of the invention, wherein water leaving the wire section is conducted into the wire pit, from which wire pit the tail water is pumped into the deaeration tank and harmful air is removed from the tail water in the deaeration tank. Then the tail water is admixed with high-consistency pulp, which is conducted further into the centrifugal cleaner installation and further according to the invention from the centrifugal cleaner installation to the multi-layer headbox.
In an embodiment containing a deaeration tank this is preferably in two parts. From the deaeration tank there are discharge fittings for each desired fraction. The pulp fraction can then be branched off to form several layers or conducted without branching in order to form one layer containing the concerned fraction.
BRIEF DESCRIPTION OF THE DRAWINGS
In the following, the invention will be described with reference to the embodiments in the appended figures, but the intention is not to limit the invention to these only.
FIG. 1 is a schematic view of the fractionation system according to the invention.
FIG. 2A is a schematic side view of the centrifugal cleaner of the first step of the centrifugal cleaner installation.
FIG. 2B is a sectional view along line I-I in FIG. 2A .
FIG. 3 shows a second advantageous embodiment of the invention, wherein tail water is conducted into a deaeration tank and then virgin stock is admixed with the flow conducted from the deaeration tank, and the flow is conducted further into the centrifugal cleaner installation and through this according to the invention to the multi-layer headbox.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows schematically the equipment according to the invention for pulp fractionation. The equipment includes a multi-layer headbox 10 and a deaeration tank 11 , which is preferably in many sections, being a two-section tank in this embodiment of the invention. In addition, the system according to the invention includes a centrifugal cleaner installation 12 , which includes at least two steps, steps 12 a 1 and 12 a 2 , that is, centrifugal cleaning degrees. In addition, the system according to the invention includes a wire pit 13 and a fitting b 1 leading from this to the first centrifugal cleaning step 12 a 1 of the centrifugal cleaning installation 12 . From the first step 12 a 1 of the centrifugal cleaning installation 12 there is a further fitting a 1 for the accept into the deaeration tank 11 , into the first section 11 a 1 of the said tank. From tank 11 a 1 there is another fitting a 2 , which branches off to form fittings a 2 ′ and a 2 ″. The fittings a 2 ′ and a 2 ″ include power screens 14 a 1 and 14 a 2 , from which the accept is conducted further along fittings a 2 ′ and a 2 ″ to a multi-layer headbox 10 and into its bypass manifolds J 1 and J 3 , from which the pulp is divided further into the headbox's set of pipes, through an intermediate chamber and a turbulence generator to the formation wire (not shown in FIG. 1 , see formation wire H 1 in FIG. 3 ) and to form the top and bottom layers of the web. The fittings, such as channels or pipes a 2 ′ and a 2 ″, include pumps P 2 and P 1 and, correspondingly, a pump P 3 is located in a fitting a 4 . Using the pumps, the pulp fractions are pumped into each bypass manifold J 1 , J 2 , J 3 of the multi-layer headbox 10 .
From the first step 12 a 1 of the centrifugal cleaner installation 12 there is a fitting b 2 by the reject, and further to fitting b 3 , which leads to the second stage of centrifugal cleaner installation 12 , that is, to second step 12 a 2 , from which there is further a fitting a 3 for the accept into the second section 11 a 2 of the deaeration tank 11 , and further a fitting a 4 , e.g. a pipe, into bypass manifold J 2 of the multi-layer headbox 10 to form the middle layer of the web. In this application, virgin stock is understood as being the new stock conducted to wire pit 13 . The stock includes fillers and additives and fibres. Thus, from the first step 12 a 1 of the centrifugal cleaner installation 12 there is a fitting a 1 into multi-section deaeration tank 11 , into its first section 11 a 1 , from which after the deaeration the fraction is transferred further into fitting a 2 , which branches off to form branch fittings a 2 ′, a 2 ″, which lead further into corresponding pulp bypass manifolds J 1 and J 3 of the multi-layer headbox 10 . Branch fittings a 2 ′, a 2 ″ include power screens 14 a 3 and 14 a 1 , from which the accept is conducted further to the corresponding bypass manifolds J 1 , J 3 of the headbox, and the reject is conducted along channels t 1 , t 3 back to the wire pit 13 . Correspondingly, from the second step 12 a 2 of the centrifugal cleaner installation 12 the accept is conducted into multi-section deaeration tank 11 , into its section 11 a 2 along fitting a 3 , and after the deaeration the said fraction is conducted to fitting a 4 , which is conducted further into the middle bypass manifold J 2 of the multi-layer headbox 10 to form the middle layer of the web. Fitting a 4 includes a power screen 14 a 2 , from which the accept is conducted into bypass manifold J 2 of the multi-layer headbox 10 , and the reject is conducted along fitting t 2 as a back flow back to wire pit 13 .
As is shown in FIG. 1 , centrifugal cleaner installation 12 may include several steps. In the embodiment shown in FIG. 1 , there are two actual fractionation steps, which are steps 12 a 1 and 12 a 2 , which are used for forming a three-layer web. Step 12 a 1 includes centrifugal cleaner cones 120 , of which there are five in the step and the accept outlets of which are joined together, while, correspondingly, the reject outlets are joined together. There is a corresponding arrangement in the other steps. The number of cones 120 in step 12 a 2 is four, in step 12 a 3 there are three, in step 12 a 4 two and in the last step 12 a 5 there is one cone. The reject outlet fitting b 2 of step 12 a 1 is connected to supply channel b 3 of the second step 12 a 2 . The reject outlet b 4 of step 12 a 2 is connected to supply fitting b 5 of the third step 12 a 3 and reject outlet b 6 of step 12 a 3 is connected to supply fitting b 7 of step 12 a 4 , reject outlet fitting b 8 of step 12 a 4 is connected to supply fitting b 9 of the last step 12 a 5 . The accepts of steps 12 a 3 , 12 a 4 and 12 a 5 , for which there is a fitting d 1 , d 2 , d 3 , are connected in such a way to the system that the accept of step 12 a 3 is made to flow along fitting d 1 to the second step 12 a 2 , into its fitting b 3 to the suction side of feed pump P 5 . Correspondingly, accept fitting d 2 of step 12 a 4 is connected with supply channel b 5 of step 12 a 3 on the suction side of feed pump P 6 and, correspondingly, accept fitting d 3 of step 12 a 5 is connected with supply fitting b 7 of step 12 a 4 on the suction side of pump P 7 . The reject taken from the last step 12 a 5 is moved entirely to the discharge or to further treatment in connection with another installation.
Fitting b 1 from wire pit 13 includes a feed pump P 4 , and there is an input fitting f for virgin stock to the wire pit. For the tail water of the wire section there is a return fitting e to wire pit 13 , and as is shown in the figure, from deaeration tank 11 between the end walls of sections 11 a 1 and 11 a 2 there is a return fitting g for overflow to wire pit 13 . Negative pressure pump arrangements in connection with deaeration tank 11 for bringing about a negative pressure in the top section of the deaeration tank are not shown. Air is removed from the fractionated pulp with the aid of a high negative pressure brought about in the deaeration tank by a negative pressure pump.
Such an embodiment is also possible within the scope of the invention, where there is no deaeration of the pulp. In systems with no deaeration of the pulp the accept of the centrifugal cleaning may be taken directly to the suction side of the headbox's feed pump. In other respects the system is similar to the one in the embodiment shown in FIG. 1 .
FIG. 2A shows one centrifugal cleaner of the first step 12 a 1 of a centrifugal cleaner installation. There may be several centrifugal cleaner cones 120 in each step 12 a 1 , 12 a 2 . . . . The accepts of the cones 120 in each step are combined with each other and the rejects are also combined and then conducted along their respective fittings a 1 , b 2 ; a 2 , b 4 . . . . As is shown schematically in the figure, the heaviest particles move along a helical path downwards in the centrifugal cleaner cone 120 and further out of the cone 120 , and from the middle at the top the accepts are conducted forward into the deaeration tank and further into that bypass manifold of the multi-layer headbox, which relates to the concerned fraction. Thus, the fractionation of the centrifugal cleaner is characterised in that fractionation takes place in the said cleaner especially as regards the pulp, whereby the heavier particles move along a helical path to the following step or stage of the centrifugal cleaning, and thus the fractionation takes place also in regard to fillers and additives and not only in regard to fibres.
FIG. 2B is a sectional view along line I-I of FIG. 2A . Fitting b 1 is joined tangentially to cone 120 . The centrifugal force thus separates the heavier particles from the pulp flow L 1 in the space 0 shaped like a truncated cone inside cone 120 , while the lighter particles and the pulp fraction separated from the other pulp are conducted (arrow L 2 ) into deaeration tank 11 of the deaeration equipment by way of fitting a 1 .
FIG. 3 shows an embodiment of the invention, wherein the tail water is conducted to wire pit 13 along fitting e and the tail water is conducted further from wire pit 13 pumped by pump P 10 along fitting b 1 into deaeration tank 11 , from which deaeration tank 11 the tail water is conducted further along fitting b 1 ′ pumped by pump P 20 to the centrifugal cleaner installation 12 . High-consistency pulp, that is, virgin stock, is fed into channel b 1 ′ to the suction side of pump P 20 . From the first step 12 a 1 of the centrifugal cleaner installation 12 the accept is conducted along fitting a 1 into branch fittings a 1 ′, a 1 ″, which include feed pumps P 1 and P 2 , and the pulp is conducted further through power screens 14 a 1 and 14 a 3 into bypass manifolds J 1 and J 3 of the multi-layer headbox 10 . From the first step 12 a 1 of the centrifugal cleaner installation 12 the reject is conducted along fitting b 2 to the second step 12 a 2 of centrifugal cleaner installation 12 as supply, and from the said step the accept is conducted along fitting a 3 pumped by pump P 3 to power screen 14 a 2 and further to the central bypass manifold J 2 of the multi-layer headbox 10 to form the middle layer of the web.
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Virgin stock is conducted to a paper or board machine and further to a centrifugal cleaner installation ( 12 ) into its first centrifugal cleaner step ( 12 a 1 ). From the first centrifugal cleaner step ( 12 a 1 ) the accept is conducted into a multi-layer headbox ( 10 ) to form a layer of the web determined according to the concerned fraction. From a second step ( 12 a 2 ) and/or from lower steps ( 12 a 3 , 12 a 4 . . . ) of the centrifugal cleaner installation ( 12 ) a second fraction or more fractions are conducted into the multi-layer headbox ( 10 ) to form a second layer or other layers of the web, which are determined according to the pulp fractionation taking place in the concerned second step or lower steps.
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BACKGROUND OF THE INVENTION
The invention relates to a retainer system for adjustable beds and specifically to a pocket formed in a mattress for receiving a retention bracket which is carried by a mattress-supporting element, such as a foot support and/or a head support of an adjustable bed, or a box spring, etc. With the retention bracket housed within the pocket of the mattress, the mattress cannot shift during adjustment of the adjustable bed and, more importantly, because of the novel construction of the pocket, the retention bracket is hidden from view and creates an aesthetic appearance to an observer.
A typical conventional mattress-retention bracket constructed in accordance with this invention is disclosed in U.S. Pat. Nos. 5,737,783 and 5,978,992 in the name of Santino Antinori granted respectively on Apr. 14, 1998 and Nov. 9, 1999. In each of these patents a mattress-retention bracket is of a generally inverted U-shaped configuration or an upstanding T-shaped configuration, and these retention brackets are secured to head, back, hip and/or foot supports of an adjustable bed. The retention brackets embrace the head, back, hip and/or foot ends of the overlying mattress and are functionally adequate for the intended purpose, but are not aesthetically acceptable because they are readily visible to a casual observer. However, in accordance with the mattress-retainer system of the present invention, such brackets are hidden from view by providing a lower opening along a peripheral edge of the mattress which opens into a pocket into which the mattress-retainer bracket can be inserted. An outer portion of the peripheral material defining the mattress cover covers the retention bracket thereby hiding the same and providing the mattress with the appearance of a conventional or standard mattress absent a pocket therein.
Other typical mattress holders and/or brackets are disclosed in U.S. Pat. No. 1,125,277 granted on Jan. 19, 1915 to Homer Eckerson and U.S. Pat. No. 1,371,098 granted on Mar. 8, 1921 to Mariana T. Jones. In each of these patents a bed frame includes a set of supporting springs upon which rests a mattress and mattress holders or brackets are attached to head ends and foot ends of the bedframe to permit the mattress to shift relative to the frame and the springs supported thereby.
U.S. Pat. No. 4,297,754 granted on Nov. 3, 1981 to Julio A. Zuniga and U.S. Pat. No. 4,017,919 granted on Apr. 19, 1977 to John H. Hemmeter each disclose a plurality of mattress-retention brackets associated with a bed, and in each of these the mattress is supported upon box springs and the mattress-retention brackets prevent each mattress from shifting relative to its associated box spring.
U.S. Pat. No. 1,842,873 granted on Jan. 26, 1932 to Mary E. Leeking discloses an adjustable bed formed by a head spring section, a foldable foot spring section and an intermediate foldable spring section therebetween with the three sections supporting a mattress and several sections being adjusted to accommodate a patient in prone, sitting or partially sitting positions. Rather than utilizing retention brackets, the mattress is held to the head, intermediate and foot spring sections by a number of flexible straps having a hooks at opposite ends which are selectively hooked to the spring sections and to eyelets or eye members of the mattress.
Published U.S. Patent Application No. 2002/0066142 A1 published on Jun. 6, 2002 in the name of Osborne et al. discloses a mattress having a transverse tubular sleeve along an underside thereof through which a rod passes with the rod being secured to an underlying mattress-supporting surface, such as a box spring for retaining the mattress positioned atop the box spring.
SUMMARY OF THE INVENTION
In keeping with the foregoing, a novel mattress-retention system particularly adapted for association with adjustable beds includes a retention bracket which can be configured in a variety of different ways, such as the retention brackets of U.S. Pat. Nos. 5,737,783 and 5,978,992 connected in upstanding projected relationship at a head end, a foot end or both head and foot ends of an associated mattress support, such as head and/or foot supports of an adjustable bed. A mattress associated with the adjustable bed is provided with a downwardly opening pocket at its head end, foot end or both its head and foot ends. The mattress includes a conventional inner mattress core which may include coil springs, polymeric/copolymeric foam plastic, combinations thereof, and upper, lower and peripheral outermost pieces of fabric which are conventionally secured together by a conventional tape edging machine except along lower or bottom edges of the head and/or foot ends of the peripheral fabric material. At one or both of the latter ends of the mattress, the peripheral edge of the mattress bottom covering and a lower edge of the peripheral covering are not edge-taped together thereby forming an upwardly accessible hidden pocket which can be accessed by the retention bracket(s). Since the retention bracket(s) is inboard of the outermost peripheral covering or fabric material of the mattress, it is unobservable from the exterior thereby imparting a highly aesthetic appearance to the overall adjustable bed and virtually renders invisible the mattress-retention bracket(s).
In a preferred embodiment of the invention, the bracket-retention pocket(s) is formed by manufacturing a mattress in a conventional manner except a limited length of the head end and/or foot end of the mattress periphery are not sewn together utilizing typical tape edging. Instead, a piece of pocket-forming material is secured along a bottom peripheral edge of the bottom outer fabric or covering of the mattress and projects freely upwardly inboard of the outer peripheral material or covering of the mattress which is tape secured along the entire periphery of the outer bottom fabric covering except in the area of the pocket-forming piece of material. The latter selective securing of the components creates an opening along a lower edge of the outer peripheral fabric or covering which defines with the pocket-forming material an upwardly accessible pocket into which the retention bracket is received. The latter construction provides an aesthetic appearance when the mattress is assembled upon the head, back, hip and leg supports of the adjustable bed because the retention bracket(s) is completely hidden from view to a casual observer.
With the above and other objects in view that will hereinafter appear, the nature of the invention will be more clearly understood by reference to the following detailed description, the appended claims and the several views illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an adjustable bed, and illustrates a wheeled adjustable bed frame including relatively adjustable head, back, hip and leg supports; a mattress support supported upon the latter body supports carrying an inverted U-shaped mattress-retention bracket at a foot end, and a mattress above the mattress support prior to assembly therewith.
FIG. 2 is a fragmentary perspective view of the adjustable bed, and illustrates the retention bracket accessed within a pocket or chamber of the mattress through an opening formed along a portion of a lower peripheral edge of the mattress at the foot or head end thereof.
FIG. 3 is an enlarged fragmentary cross-sectional view of the mattress taken generally along line 3 — 3 of FIG. 7 , and illustrates details of the chamber or pocket and the lower opening for accessing the pocket with the retention bracket by lowering the mattress from the position shown in FIG. 1 to the position shown in FIG. 2 .
FIG. 4 is a schematic perspective view, and illustrates the mattress inverted with its bottom uppermost and a separate piece of pocket-forming border material which is insertable into a foot end (or head end) of the mattress inboard of the peripheral fabric or covering which is folded downwardly for purposes of assembly.
FIG. 5 is a schematic perspective view similar to FIG. 4 , and illustrates a conventional tape edging machine securing a lower edge of the pocket-forming material to a peripheral edge of the bottom mattress covering.
FIG. 6 is a schematic view of the mattress, and illustrates the tape edging machining securing the peripheral edge of the bottom mattress covering to the mattress peripheral covering lower edge beginning substantially midway at the head end of the mattress, continuing along the right side, the subsequent corner, excluding the area of the pocket ( FIG. 5 ) previously tape edged only to the peripheral edge of the mattress bottom covering, continuing taping adjacent the succeeding corner and continuing to the mid-portion of the head end of the mattress.
FIG. 7 is an enlarged fragmentary perspective view of the completed mattress of FIGS. 3 and 6 and specifically the pocket thereof, and illustrates the manner in which the peripheral edge taping of the peripheral covering excludes the area of the pocket-forming border material or insert to define an access area or opening opening into the mattress-retainer pocket or chamber.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
An adjustable bed B ( FIGS. 1 and 2 ) includes a conventional frame F having wheels or casters W and appropriate linkages, motors and drives (not shown) of a conventional bed adjusting mechanism BAM for moving a mattress-supporting member or mattress support S between numerous positions of adjustment, as shown in FIGS. 1 and 2 of U.S. Pat. Nos. 5,737,783 and 5,978,992, the details of which are herein incorporated by reference. The mattress support S includes a mattress head support Sh, a mattress back support Sb, a mattress hip support Sh′ and a mattress foot support Sf with the latter having secured thereto a mattress-retention bracket MR of a generally inverted U-shaped configuration. The bed adjusting mechanism BAM articulates the pivotally movable mattress supports Sh, Sb, Sh′ and SF between planar ( FIGS. 1 and 2 ) and nonplanar (not shown) positions. Though the mattress-retention bracket MR is located at the mattress foot support Sf, the same can be located at the mattress head support end Sh or at both mattress supports Sf, Sh.
The mattress bracket MR defines one component of a mattress-retention system MRS ( FIG. 2 ) which includes as a second component thereof a mattress-retention bracket receiving pocket or chamber P ( FIGS. 1 through 3 ) accessible through a lower opening 0 ( FIGS. 3 and 7 ) of a mattress 10 which is constructed in a novel manner in accordance with the present invention.
The mattress 10 includes a mattress core 11 ( FIG. 3 ) of a substantially conventional construction including coil springs 12 foam plastic corner pieces Cp ( FIGS. 4–6 ), upper and lower relatively thick fabric layers 13 , 14 , respectively, and upper and lower relatively thin, though dense, mesh fabric 15 , 16 , respectively, with a layer of polymeric/copolymeric foam plastic material 17 being sandwiched between the layers 13 , 15 . Another foam layer 20 lies atop the fabric 15 and is covered by an outermost upper or top fabric material, cover or covering 21 defining the uppermost surface of the mattress 10 which can be appropriately stitched by spaced stitching 22 ( FIG. 1 ) to impart a conventional quilted characteristic mattress appearance thereto. Outboard peripheral edge portions 25 , 26 ( FIG. 3 ) of the thin mesh fabric or fabric material 15 , 16 , respectively, are spaced from each other along the entire periphery of the mattress 10 , as is readily apparent from FIG. 3 . An outer peripheral covering 31 formed of a piece of fabric material peripherally bounds or encases the entire periphery of the mattress core 11 and an upper edge 32 thereof ( FIG. 3 ) is secured by edge tape Te and edge stitching Se utilizing a conventional tape edging machine TEM ( FIGS. 5 and 6 ) to entirely peripherally unite the peripheral covering 31 to an edge 33 of the top or upper fabric covering 21 ( FIG. 3 ).
Reference is made to FIG. 4 of the drawings which illustrates the mattress 10 constructed as thus far described inverted from the position shown in FIG. 3 with the uppermost or top covering 21 at the bottom and the peripheral covering 31 projecting upwardly therefrom with a peripheral edge 34 thereof opposite the peripheral edge portion 32 being partially folded downwardly to expose the foot end of the mattress 10 and the inner core 11 thereof into which is inserted a substantially polygonal or rectangular piece of plastic reinforcing foam 40 ( FIGS. 3 and 4 ) which reinforces the mattress 10 in the area of the pocket P, as is most readily apparent from FIG. 3 of the drawings.
The piece of reinforcing foam 40 slightly overlies the peripheral edge portions 25 , 26 of the respective fabric pieces 15 and 16 ( FIG. 3 ). Since the outer peripheral covering 31 relatively tightly encases the periphery of the mattress core 11 , the reinforcing plastic foam piece 40 is retained frictionally therein in the position shown in FIG. 3 but may, if desired, be sewn or adhesively united to the edge portions 25 , 26 of the pieces of material 15 , 16 .
Thereafter, a sheet of pocket-forming border material 50 of a polygonal configuration larger than that of the plastic foam piece 40 is inserted into the foot end of the mattress, as indicated by the headed arrow I associated therewith in FIG. 4 with an upper edge 51 thereof, as viewed in FIG. 4 , which is the lower edge 51 in FIG. 3 , immediately adjacent a foot edge 52 of a lower or bottom covering 55 of the mattress 10 and a remote terminal edge 53 ( FIG. 3 ) being inboard of and adjacent the peripheral edges 32 , 33 of the respective peripheral covering 31 and upper covering 21 ( FIG. 3 ). Thereafter, a length of pocket-forming tape Tp ( FIG. 5 ) is secured by stitching Sp of the conventional tape edging machine TEM to the edges 51 , 52 of the respective pocket-forming border material 50 and bottom covering 55 only along the length of the tape Tp ( FIG. 5 ) which corresponds to the length of the opening 0 which is formed when the peripheral covering 31 is subsequently progressively unfolded to cover the entirety of the pocket-forming fabric material 50 , as is readily visualized in FIG. 6 of the drawings.
Tape edging of the bottom covering 55 to the peripheral covering 31 by the tape edging machine TEM begins at the head end of the mattress ( FIGS. 6 and 7 ) which applies bottom tape Tb and associated bottom stitching Sb ( FIG. 3 ) to unite the peripheral edge 52 of the bottom covering 55 to the bottom edge 34 of the peripheral covering 31 , along the entire lengths thereof except in the area of the tape Tp ( FIG. 7 ). In other words, as is best visualized in FIGS. 6 and 7 , the tape Tb secures the edges 52 , 34 of the respective bottom covering 55 and peripheral covering 31 to each other halfway along the head end of the mattress ( FIG. 6 ), around the adjacent corner, and along a portion of the right side. As the tape edging proceeds, the edges 52 , 34 are secured to each other by the tape Tb until a first edge E 1 ( FIGS. 6 and 7 ) of the tape Tp is encountered, and at this point the tape Tb is applied only to the edge 34 ( FIGS. 3 and 7 ) of the peripheral covering 31 until the edge Et of the tape Tp is reached at which point the edges 34 , 52 are again secured to each other by the tape Tb which continues to the starting point of the edge taping operation at the head end of the mattress 10 . In this manner, the opening 0 ( FIGS. 3 and 7 ) is defined between the tape Tp and the opposing portion to the tape Tb of the peripheral covering 31 which permits upward access, as viewed in FIGS. 1–3 , into the pocket or chamber P by the mattress-retention bracket MR in the manner readily apparent from FIGS. 1 , 2 and 3 of the drawings. As is particularly emphasized in FIG. 2 of the drawings, the mattress-retention bracket MR is essentially invisible or unobservable because it is, obviously, hidden in the pocket P. Obviously, the bed-adjusting mechanism BAM ( FIG. 1 ) can be selectively operated to adjust or articulate the adjustable bed B to and between desired positions of adjustment during which the mattress supports Sh, Sb, Sh′ and Sf will pivot conventionally relative to each other. However, because the mattress-retention system MRS, specifically the mattress-retention bracket MR housed in the chamber or pocket P of the mattress 10 , the mattress 10 will be held at all times in substantial peripheral alignment with the underlying mattress support S.
Although a preferred embodiment of the invention has been specifically illustrated and described herein, it is to be understood that minor variations may be made in the apparatus without departing from the spirit and scope of the invention, as defined by the appended claims.
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The invention is directed to a mattress retainer system for adjustable beds which includes a mattress-retention bracket housed within a pocket of a mattress accessible in an upward direction through an opening along a bottom edge of the mattress. The pocket is formed by attaching a separate piece of material along a bottom edge of the mattress at one or both of opposite head/foot ends thereof and permitting an overlying downwardly projecting portion of a peripheral covering of the mattress to remain free thereby defining the opening into the pocket.
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FIELD
[0001] The invention relates to braking systems, and in particular to an electrically controlled hydraulic booster.
BACKGROUND
[0002] A braking system typically includes a master cylinder which is fluidly coupled to downstream braking circuits. Typically the master cylinder is selectively coupled to a fluid reservoir. A seal arrangement allows fluid flow from the reservoir to the master cylinder and also isolates the master cylinder form the reservoir. A master cylinder piston within the master cylinder slidably seals against the seal arrangement in order to pressurize fluid within the master cylinder, and thereby pressurize the downstream braking circuits.
[0003] In modern braking systems a boost system is typically provided to supply a boost function (i.e., assist in moving the master cylinder piston by providing a boosted force to the master cylinder piston in place or in addition to a force provided by the operator to a brake pedal). Typically the boost function is provided by either a vacuum boost system utilizing available vacuum in an engine, or by a hydraulic boost system. In the hydraulic boost system, a high pressure fluid generator, e.g., a pump, provides high fluid pressure to an accumulator which is utilized to provide the desired boost function.
[0004] The hydraulic boost system uses position of an input rod that is mechanically coupled to the brake pedal in order to determine the amount of boost. The amount of boost that is provided to the master cylinder piston is relative to the position of the brake pedal.
[0005] Furthermore, in a failure mode (i.e., when the high pressure system is inoperable), providing a limited braking function remains desirable.
[0006] Therefore, it is highly desirable to provide a hydraulic boost system utilizing a high pressure source which is capable of quickly reacting to movement of the brake pedal and provide a boosted force to the master cylinder piston in response to the position of the input rod coupled to the brake pedal and also provide a limited braking function in a failure mode in which the high pressure source is inoperable.
SUMMARY
[0007] According to one embodiment of the present disclosure, there is provided a braking system with an electric hydraulic booster. The braking system with an electric hydraulic booster includes a booster chamber, a booster piston activating chamber, a booster piston located between the booster chamber and the booster activating chamber, and a solenoid valve operably connected to a high pressure source, the booster chamber, and the booster piston activating chamber, the solenoid movable between (i) a first position whereat the booster chamber and the booster piston activating chamber are in fluid communication and fluidly isolated from the high pressure source, (ii) a second position whereat the booster chamber and the booster piston activating chamber are fluidly isolated from each other and from the high pressure source, and (iii) a third position whereat the booster piston activating chamber and the high pressure source are in fluid communication and fluidly isolated from the booster chamber.
[0008] According to one embodiment of the present disclosure, there is provided a braking system with an electric hydraulic booster. The braking system with an electric hydraulic booster includes a high pressure source, a booster chamber, a booster piston rearward of the booster chamber, and a solenoid valve including a first port selectively fluidly coupled with the high pressure source, a second port selectively fluidly coupled with the booster chamber, and a third port in fluid communication with a rear facing portion of the booster piston.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 depicts a partial cross sectional view of a braking system including a high pressure accumulator, a reservoir, a boost piston assembly, a master cylinder assembly, and a pressure regulating assembly, wherein the pressure regulating assembly is positioned in a first position;
[0010] FIG. 2 depicts a partial cross sectional view of the boost piston assembly, depicted in FIG. 1 ;
[0011] FIG. 3 depicts a partial cross sectional view of the master cylinder assembly, depicted in FIG. 1 ;
[0012] FIG. 4 depicts a partial cross sectional view of the pressure regulating assembly, depicted in FIG. 1 ;
[0013] FIG. 5 depicts a partial cross sectional view of the braking system shown in FIG. 1 in an initial activation position, wherein the pressure regulating assembly is placed in a second position; and
[0014] FIG. 6 depicts a partial cross sectional view of the braking system shown in FIG. 1 in a subsequent activation position, wherein the pressure regulating assembly is placed in a third position.
DESCRIPTION
[0015] For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and described in the following written specification. It is understood that no limitation to the scope of the invention is thereby intended. It is further understood that the present invention includes any alterations and modifications to the illustrated embodiments and includes further applications of the principles of the invention as would normally occur to one of ordinary skill in the art to which this invention pertains.
[0016] Referring to FIG. 1 , a partial cross sectional view of a braking system 100 is depicted. The braking system 100 includes a housing 102 , a high pressure accumulator 104 , and a reservoir 106 . The high pressure accumulator 104 is mechanically coupled to the housing 102 and is fluidly coupled to a high pressure generator (not shown), e.g., a pump (typically an electric motor/pump is utilized for this purpose). The high pressure generator (not shown) is fluidly coupled to the reservoir 106 and maintains high pressure within the high pressure accumulator 104 by pumping fluid from the reservoir 106 thereto.
[0017] The braking system 100 further includes a boost piston assembly 108 and a master cylinder assembly 110 . The boost piston assembly 108 is slidably disposed within the housing 102 and is configured to move from right to left with reference to FIG. 1 in response to application of high pressure fluid from the high pressure accumulator 104 , as described further below. An input rod 112 is partially positioned within the boost piston assembly 108 and is configured to move therein. The input rod 112 is coupled to a brake pedal (not shown) in a manner in which movement of the brake pedal (not shown) is translated into linear movement of the input rod 112 . The input rod 112 includes a collar 114 which interfaces with a washer 166 to limit the rightward travel of the input rod 112 , as described further below with reference to FIG. 2 . Additionally, a spring 115 is positioned between the collar 114 and the boost piston assembly 108 and is configured to bias the input rod 112 away from the boost piston assembly 108 , and particularly toward the washer 166 .
[0018] Also included in the braking system 100 is a pressure regulating assembly 116 . The pressure regulating assembly 116 is mechanically coupled to the housing 102 and is in fluid communication with the high pressure accumulator 104 and the reservoir 106 . The pressure regulating assembly 116 defines a booster piston activating chamber 118 , an internal chamber 120 , and a fluid channel 124 .
[0019] The interface between the boost piston assembly 108 and the master cylinder assembly 110 defines a boost chamber 126 , while the master cylinder assembly defines a master cylinder chamber 128 . The boost chamber 126 is in selective fluid communication with the reservoir 106 via a fluid channel 208 , a chamber 130 and a fluid channel 132 (see also FIG. 3 ). The master cylinder chamber 128 is also in selective fluid communication with the reservoir 106 via a fluid channel 206 , and also in continuous fluid communication with a downstream braking circuit (not shown).
[0020] Referring to FIG. 2 , a partial cross sectional view of the boost piston assembly 108 is depicted. The boost piston assembly 108 includes a rear body portion 152 , a reaction washer assembly 154 , and a front body portion 158 . The front body portion 158 includes a cavity 160 which partially defines the boost chamber 126 . Within the cavity is a spring 210 (depicted in phantom) which biases the front body portion 158 away from a master cylinder piston 205 of the master cylinder assembly 110 , described further below in reference to FIG. 3 . The front body portion 158 interfaces with the rear body portion 152 via the reaction washer 154 .
[0021] The reaction washer assembly 154 is a composite member which may include a resilient member 155 and a stiff member 156 . Alternatively the reaction washer assembly 154 may be a single stiff member. The reaction washer assembly 154 is positioned within a cavity 157 of the rear body portion 152 .
[0022] The rear body portion 152 also includes a cavity 168 for receiving the input rod 112 and a travel sensor 162 . The input rod 112 (depicted in phantom) is slidably positioned within the cavity 168 and is configured to move leftward within the cavity 168 , but be limited in its rightward by the washer 166 , as described above. The washer 166 is fixedly coupled to the rear body portion 152 .
[0023] The travel sensor 162 is also fixedly coupled to the rear body portion 152 and is configured to generate an electrical signal placed on a cable 164 corresponding to the relative position of the input rod 112 with respect to the travel sensor 162 . The cable 164 may have multiple wires for transmitting and receiving signals thereon. The travel sensor 162 is coupled to an electronic control unit (ECU, not shown) which is configured to the control pressure regulating assembly 116 and the pressure within the boost activating chamber 118 and the boost chamber 126 , as further described below. The ECU (not shown) contains memory including program instructions that may be executed by a processor aboard the EC (not shown).
[0024] The travel sensor 162 may be of a digital type sensor, e.g., a frequency shift keying type, configured to generate a signal with varying frequencies, or an analog type sensor, e.g., an amplitude modulated type sensor configured to generate varying amplitudes in response to position of the input rod 112 .
[0025] As described above, the spring 115 (depicted in phantom) biases the input rod 112 away from a step 170 formed in the rear body portion 152 by providing a biasing force on the collar 114 of the input rod 112 .
[0026] The boost piston assembly 108 also includes seals 172 and 174 for sealing the rear body portion 152 against the housing 102 .
[0027] Referring to FIG. 3 , a partial cross sectional view of the master cylinder assembly 110 is depicted. The master cylinder assembly 110 includes a cylinder 202 defining an end portion 204 , the master cylinder piston 205 and the fluid channels 206 and 208 . The space between the end portion 204 and the master cylinder piston 205 defines the master cylinder chamber 128 while the space between the master cylinder piston 205 and the front body portion 158 (depicted in phantom) of the boost piston assembly 158 defines the boost chamber 126 . As described above, the spring 210 biases the front body portion 158 away from the master cylinder piston 205 , while a spring 212 biases the master cylinder piston 205 away from the end portion 204 .
[0028] A seal 214 is configured to isolate the boost chamber 126 from the reservoir 106 . For example, as depicted in FIG. 3 , the front body portion 158 (depicted in phantom) is position beyond the fluid channel 208 but not beyond the seal 214 . Therefore, the boost chamber 126 as depicted in FIG. 3 remains in fluid communication with the reservoir 106 .
[0029] Two seals 216 and 218 are configured to isolate the master cylinder chamber 128 from the reservoir 106 . For example, as depicted in FIG. 3 , the position of the master cylinder piston 205 is beyond the seal 216 and the fluid channel 206 , but not beyond the seal 218 . Therefore, the master cylinder chamber 128 as depicted in FIG. 3 is in fluid communication with the reservoir 106 .
[0030] Referring to FIG. 4 , a partial cross sectional view of the pressure regulating assembly 116 is depicted. The pressure regulating assembly 116 includes a body portion 252 (depicted in segments) and a bracket 254 . The body portion 252 is sealed with the housing 102 by seals 250 and 251 .
[0031] The pressure regulating assembly 116 also includes a seal member 256 which is sealingly disposed between an inlet member 258 defining an inlet seat 262 and a spring loaded socket 266 . The spring loaded socket 266 is biased away from the body portion 252 and toward the seal member 256 by a spring 268 . The spring loaded socket 266 is configured to interface with the seal member 256 in a sealed manner in which the high pressure accumulator 104 is isolated from the interface between the seal member 256 and the spring loaded socket 266 .
[0032] The pressure regulating assembly 116 also includes a solenoid assembly 270 . The solenoid assembly is biased away from the inlet member 258 by the spring 272 . The solenoid assembly 270 includes a coil 274 , a core 276 , and a core extension 280 . The coil 274 is fixedly coupled to the body portion 252 , while the core 276 and the core extension 280 are slidably disposed between segments of the body portion 252 . The core extension 280 is fixedly coupled to the core 276 and is configured to move in response to movement of the core 276 . The core extension 280 may be integrally formed with the core 276 or may be formed as a separate member coupled to the core 276 with a fastener. The core extension 280 includes a hollow center 282 which is in fluid communication with the chamber 130 and, therefore, with the reservoir 106 .
[0033] The pressure regulating assembly 116 also includes a hollow outlet seat 284 with an inner bore 286 . The outlet seat 284 is aligned with the core extension 280 in a manner in which the inner bore 286 of the outlet seat 284 is substantially aligned with the hollow center 282 of the core extension 280 .
[0034] The outlet seat 284 is fixedly coupled to the core extension 280 at a first end of the outlet seat 284 . The interface between the outlet seat 284 and the core extension 280 may be one of a permanent type, e.g., welded members, or of a fastened type. The outlet seat 284 includes a seat 288 at a second end of the outlet seat 284 . The seat 288 is configured to interface with the seal member 256 and form a seal.
[0035] The operation of the braking system 100 is described with initial reference to FIG. 1 . The position of the input rod 112 depicted in FIG. 1 corresponds to the brake pedal (not shown) in a released position. The position of the braking system 100 depicted in FIG. 1 is hereinafter referred to as the “rest” position. In the rest position, the boost chamber 126 and the master cylinder chamber 128 are in fluid communication with the reservoir 106 via the fluid channels 208 and 206 (see FIG. 3 ).
[0036] In the rest position, the solenoid assembly 270 is de-energized by the ECU (not shown). Therefore, the spring 272 biases the outlet seat 284 to a location spaced apart from the seal member 256 . Thus, the inner core 286 and the hollow center 282 provide a vent path for the boost activating chamber 118 through the fluid channel 124 to the chamber 130 and the reservoir 106 (see FIG. 4 ).
[0037] Additionally, the spring 268 acting on the spring loaded socket 266 which is firmly in contact with the seal member 256 (or integrally formed therewith) forces the seal member 256 against the inlet seat 262 of the inlet member 258 , thereby sealing the boost activating chamber 118 from high pressure accumulator 104 .
[0038] Therefore, the boost chamber 126 which is in fluid communication with the chamber 130 in the rest position is in fluid communication with the boost activating chamber 118 and isolated from the high pressure accumulator 104 .
[0039] Referring to FIG. 5 , the input rod has moved leftward as compared to FIG. 1 , in response to the operator applying a force to the brake pedal (not shown). The movement of the input rod is particularly exemplified by the separation between the collar 114 and the washer 166 . The spring 115 is compressed in response to the leftward movement of the input rod 112 .
[0040] The travel sensor 162 senses the leftward movement of the input rod 112 and provides a signal on the cable 164 to the ECU (not shown). The ECU (not shown) receives the signal and energizes the coil 274 , e.g., by providing a first voltage level to the coil 274 , which magnetically force the core 276 and the core extension 280 rightward (with reference to FIG. 5 ). Since the outlet seat 284 is fixedly coupled to the core extension 280 , the outlet seat 284 moves rightward and makes contact with the seal member 256 .
[0041] The position of the braking system depicted in FIG. 5 is also referred to as the initial activation position. In the initial activation position, the seat 288 of the outlet seat 284 seals against the seal member 256 , thus, the fluid path including the hollow center 282 and the inner core 286 of the outlet seat 284 no longer provides fluid communication between the chamber 130 and the boost activating chamber 118 . Therefore, these chambers are isolated from each other. Since the boost chamber 126 in the rest position depicted in FIG. 1 or the initial activation position depicted in FIG. 6 is in fluid communication with the chamber 130 , the boost chamber 126 is also isolated from the boost activating chamber 118 .
[0042] Since the inlet seat 262 of the inlet member 258 remains firmly seated on the seal member 256 , thereby providing a seal, the boost activating chamber 118 and the boost chamber 126 remain isolated from the high pressure accumulator 104 . In the initial activation position, the braking system is in a ready position to provide the desired braking function.
[0043] Referring to FIG. 6 , the input rod 112 has traveled further leftward. The travel sensor 162 senses the leftward travel of the input rod 112 and places an electrical signal corresponding to the position of the input rod 112 on the cable 164 . The ECU (not shown) receives the signal and further energizes the coil 274 , e.g. by providing a second voltage level which is higher than the first voltage level. In response to the additional energizing of the coil 274 , the core 276 and the core extension 280 travel further rightward with reference to FIG. 6 which rightward movements cause the outlet seat 284 to further move rightward. The additional rightward movement of the outlet seat 284 moves the seal member 256 off of the inlet seat 262 of the inlet member 258 . The force applied to the seal member 256 , which remains in firm contact with the spring loaded socket 266 , by the outlet seat 284 compresses the spring 268 (see also FIG. 4 ). In this position, the booster activating chamber 118 and the high pressure accumulator 104 are in fluid communication with each other via the internal chamber 120 and the fluid channel 124 .
[0044] With fluid entering the boost activating chamber 118 , pressure therein begins to rise. In response to the pressure rise, the boost piston assembly 108 moves leftward and thereby moves the front body portion 158 , which is in contact with the reaction washer assembly 154 , leftward (with reference to FIG. 6 ). The leftward movement of the boost piston assembly 108 causes the front body portion 158 to seal against the seal 214 , and thereby isolates the boost chamber 126 from the chamber 130 and the reservoir 106 (see also FIG. 3 ).
[0045] Once the boost chamber 126 is isolated from the reservoir 106 , pressure rises in the boost chamber 126 . The pressure rise applies a force to the master cylinder piston 205 which moves it leftward sealing against the seal 218 , which thereby isolates the master cylinder chamber 128 from the reservoir 106 .
[0046] Once the master cylinder chamber 128 is isolated from the reservoir 106 , pressure in the master cylinder chamber 128 rises. Since the master cylinder chamber 128 is in continuous fluid communication with the downstream braking circuit (not shown), the pressure rise provides the desired braking function.
[0047] With the leftward movement of the boost piston assembly 108 , the washer 166 once again comes in contact with the collar 114 (as depicted in FIG. 6 ). The relative positions of the input rod 112 and the boost piston assembly 108 , and in particular the travel sensor 162 , causes the travel sensor 162 to generate a signal in correspondence thereto. The signal generated by the travel sensor 162 , and placed on the cable 164 , is received by the ECU (not shown). In response thereto, the ECU (not shown) reduces the energy provided to the coil 274 , e.g., by providing a third voltage to the coil 274 , whereby the third voltage is substantially the same as the second voltage.
[0048] In response to receiving the smaller energy, the coil 274 provides a smaller magnetic force. Since the core 276 and the core extension 280 are biased away from the inlet member 258 which is fixedly coupled to the body portion 252 , the core 276 and the core extension 280 move leftward (with reference to FIG. 6 ). Since the outlet seat 284 is fixedly coupled to the core extension 280 , the outlet seat 284 also moves leftward, which allows the seal member 256 to seal against the inlet seat 262 of the inlet member 258 (see also FIG. 4 ). Therefore, the solenoid assembly 270 returns to the position depicted in FIG. 5 . As described above, in the position depicted in FIG. 5 , the boost activating chamber 118 and the boost chamber 126 are isolated from each other and from the high pressure accumulator 104 . The difference with the position of the boost piston assembly 108 and the master cylinder assembly 110 that is depicted in FIG. 5 , however, is that the boost chamber 126 in FIG. 6 is isolated from the reservoir 106 . In this isolated position, the pressure in the boost chamber is raised, as compared to the boost chamber 126 in FIG. 5 , and thereby maintains a force on the master cylinder piston 205 .
[0049] The ECU (not shown) continues to increase and decrease the energy applied to the coil 274 by switching between the first and second voltage levels. Thereby the seal member 256 moves right and left with respect to FIG. 6 , in order to provide a modulation of pressure in the boost activating chamber 118 .
[0050] While not shown, the boost chamber 126 may be continuously coupled to another downstream braking circuit, in order to provide a separate braking function.
[0051] Also, while not shown, in the event of a failure of high pressure in the high pressure accumulator 104 , e.g., due to failure of the high pressure generator (not shown), the input rod 112 may in response to movement of the brake pedal (not shown) move leftward and make contact with the reaction washer assembly 154 . The contact between the input rod 112 and the reaction washer assembly 154 provides the capability of moving the front body portion 158 to provide braking without the boost function. Release of the brake pedal (not shown) moves the input rod 112 rightward which moves the reaction washer assembly 154 and the front body portion 158 rightward, to reduce the braking. The rightward movement is partially generated by the biasing force of the spring 115 .
[0052] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same should be considered as illustrative and not restrictive in character. It is understood that only the preferred embodiments have been presented and that all changes, modifications and further applications that come within the spirit of the invention are desired to be protected.
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A braking system with an electric hydraulic booster includes a booster chamber, a booster piston activating chamber, a booster piston located between the booster chamber and the booster activating chamber, and a solenoid valve operably connected to a high pressure source, the booster chamber, and the booster piston activating chamber, the solenoid movable between (i) a first position whereat the booster chamber and the booster piston activating chamber are in fluid communication and fluidly isolated from the high pressure source, (ii) a second position whereat the booster chamber and the booster piston activating chamber are fluidly isolated from each other and from the high pressure source, and (iii) a third position whereat the booster piston activating chamber and the high pressure source are in fluid communication and fluidly isolated from the booster chamber.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to novel compositions for the softening and/or loosening of unwanted organic coatings for removal from surfaces, such as oven surfaces which are soiled by baked-on organic or carbon deposits. This invention also relates to methods of making these novel compositions and to methods of using them. Other unwanted organic coatings which can be softened or loosened for removal by the compositions of this invention include organic paint, varnish, shellac or lacquer coatings that are desired to be stripped from surfaces to which they are applied.
2. Description of the Prior Art
The job of periodically cleaning soil from interior surfaces of home ovens or commercial food ovens or cooking utensils often is disagreeable. The soil normally has been baked-on by several heatings between the time it was deposited and the time that its removal is attempted and, therefore, is difficult to remove. Mechanical removal as by chipping with a tool or scrubbing with abrasives is arduous, potentially hazardous to the surface and/or the worker and usually is not very effective. Two currently popular means for removing soils of this type are (a) the self-cleaning oven which uses extremely high temperatures and catalytic oven surfaces to oxidize and burn off the soil and (b) the application of a cleaner which dissolves, softens and/or lifts the soil from the surfaces. Most of the oven cleaners currently being marketed contain strong caustic or alkaline materials which can cause severe burns and tissue damage if they contact the skin or eyes and there is a high level of interest in safer oven cleaning compositions.
As illustrated by U.S. Pat. Nos. 3,031,408; 3,031,409; 3,079,284; 3,196,046; 3,331,943; 3,335,092; 3,549,419; 3,684,576; 3,715,324; 3,779,933; 3,829,387 and others, oven interiors soiled by baked-on grease and spattered foods have been cleaned by applying solutions of saponification agents or materials that provide ammonia gas which condenses on the oven walls, usually preceded or followed by heating of the soiled interiors in order to cause a chemical reaction with the soil. However, the use of these solutions is accompanied by certain drawbacks, such as, harsh fumes emanating from the oven, and/or they are harmful to the eyes and skin on contact due to caustic. These solutions are also capable of producing corrosive damage to aluminum surfaces, if accidentally spilled on them.
Products containing catalytic metal salts and oxides are also described which substitute for catalytic coatings in self-cleaning ovens. These coatings require higher than normal cooking temperatures in order to be operable.
U.S. Pat. No. 3,658,711 discloses oven cleaning compositions containing an alkali metal or ammonium carbonate, phosphate, borate or silicate and a polyoxyethylene glycol amine enhancer. While these compositions avoid the use of caustic alkalis, the amine contributes to a higher pH and presents the possibility of injury to the skin or tissue. Alkali metal carbonates are themselves quite stable and will not convert to alkali metal hydroxides under the conditions of oridinary use and, thus, are lacking in cleaning ability.
U.S. Pat. No. 3,808,051 describes oven cleaning compositions containing salts of mixed alkali metals and a volatile weak organic acid. The salt mixtures become molten at elevated temperatures and the weak organic acid moiety volatilizes to release alkali metal ions which attack the soil. Thereafter, the soil residue is washed from the surface. These compositions require relatively high temperatures to become operable and cannot function at room temperature. Furthermore, during washing to remove the soil, the user is faced with the potential hazards of removing and handling caustic alkalis.
SUMMARY OF THE INVENTION
The present invention is based, in part, on the discovery that effective, safer cleaning compositions can be made from organic amines, that attack unwanted organic coatings on surfaces desired to be cleaned, by neutralizing an aqueous solution of the amine with carbon dioxide. The amine solution is thus rendered substantially less corrosive to the eyes or skin than the amines themselves or the caustic alkalis and other strongly alkaline materials employed by the prior art. The organic amine solutions neutralized with CO 2 forming the cleaning compositions of this invention are sufficiently unstable when applied as an over-coating on the unwanted coating, that a reduction in partial pressure of carbon dioxide acting on the composition, either by heating and/or by standing open to the atmosphere of a relatively large enclosure, e.g., a room or oven, liberates CO 2 leaving the free organic amine which then acts on the unwanted coating to loosen, soften and/or make it more amenable to mechanical removal, as by rinsing, wiping or scraping. It was also unexpectedly discovered that the pH of the neutralized organic amine solutions are far below the normal pH of the unneutralized aqueous solutions of the organic amine itself and that the pH of the composition over-coating does not elevate to the normal pH of the unneutralized solution of organic amine as CO 2 is released during the cleaning operation. This phenomenon is shown by the plot of the drawing and is distinct from the action of prior art materials which contain caustic or highly alkaline substances and have high pH's throughout the cleaning operation. Consequently, the compositions of this invention are not only safer during application but they are also safer during removal.
Accordingly, the present invention relates to the loosening or softening of unwanted organic coatings bonded to a surface by the application to the coatings of an aqueous amine solution neutralized with CO 2 , said solution being capable of decomposing to release the CO 2 leaving the amine when subjected to conditions wherein the partial pressure of carbon dioxide acting on the solution is less than the partial pressure of carbon dioxide of the solution at the temperature and CO 2 partial pressure in the atmosphere in which the composition is used to clean the surface, the amine preferably having a boiling point in excess of the temperature at which the composition is used for cleaning the surface and being capable, alone or in conjunction with a water-soluble organic solvent, of loosening or softening the unwanted coating on the surface. The invention includes cleaning compositions containing the above-described aqueous solutions and thickening agents for increasing viscosity to facilitate the adherence of the compositions to inclined and vertical surfaces and ceilings and/or water-soluble organic solvents to assist in the loosening or softening action. The invention also includes novel aerosol products containing the novel compositions and to novel methods of preparing the novel compositions.
BRIEF DESCRIPTION OF THE DRAWING
The drawing is a plot of pH versus time in hours of two compositions applied as an over-coating to baked-on cooking soil and kept in a 90° C. oven to illustrate the pH of the applied composition at various points in time after application over a three hour period. (See Examples 16 and HHH). The compositions are identical except that the one illustrating the invention (Example 16) was neutralized with CO 2 before application. The plot shows that throughout the three hour period after application of the novel composition as an over-coating, the pH of the novel composition over-coating never exceeded 10 whereas the pH of the over-coating which contained no CO 2 was at all times in excess of 10.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The novel compositions of this invention are based on aqueous solutions of CO 2 -neutralized solutions of water-soluble organic amines. Methods of preparing aqueous solutions of this type are well known in the art and involve the reaction of carbon dioxide with the amine in aqueous solution. The reaction can be carried out by mixing carbon dioxide in gaseous or solid form with the aqueous amine solution until the reaction has proceeded to the desired extent. Any reaction conditions can be employed, although low temperatures such as room temperature or lower facilitate the dissolution of the carbon dioxide in the aqueous amine solution for reaction with the amine. Higher temperatures can be used; however, they tend to increase the partial pressure of carbon dioxide of the solution, slow the entry of additional carbon dioxide into the solution and consequently tend to retard the neutralization and impede the reduction of pH. Gentle to moderate stirring or mixing, of course, serves to facilitate the dissolution of carbon dioxide and aids in accelerating the reaction. The initial pH of the aqueous amine solution is usually in excess of 11 and the reaction with carbon dioxide can be continued until the pH of the solution drops to 10 or below, preferably 8 or below. Most preferably the pH is reduced as close to 7 as possible. The resulting aqueous solution, with or without the addition of other ingredients, then can be packaged in a container which is capable of maintaining a partial pressure of at least one atmosphere carbon dioxide at room temperature acting on the solution greater than the partial pressure in the solution over the temperature range to which the container can be expected to be subjected. Suitable containers are gas-tight jars, bottles or cans for application by brush, sponge, cloth, mop etc. or aerosol containers for application by spraying.
The water-soluble organic amines used in this invention are those that are capable, alone or in conjunction with water-soluble organic solvents, of loosening or softening the unwanted coating. Preferably, they have boiling points in excess of the temperature at which the composition is used for loosening or softening the unwanted coating on the surface being cleaned. These water-soluble organic amines are capable of forming carbonates and/or bicarbonates and/or other compounds with carbon dioxide in aqueous solution which carbonates and/or bicarbonates and/or other compounds are capable of decomposing to said amine and carbon dioxide when subjected to conditions wherein the partial pressure of carbon dioxide acting on the solution is less than the partial pressure of carbon dioxide in the solution at the temperature at which the composition containing it is used to clean the surface. Without intending to be bound to any particular theory or mechanism of reaction, it is believed that the formation of the novel CO 2 -neutralized aqueous amine solutions of this invention can be depicted by the following equations, R 3 N representing the water-soluble organic amine wherein one or two of the R's can be hydrogen and one or two of three R' s individually can be organic groups or two R's taken together comprise an organic group:
2R.sub.3 N + 2H.sub.2 O ⃡ 2R.sub.3 NH.sup.+ + 2OH.sup.-
co.sub.2 + h.sub.2 o ⃡ h.sup.+ + hco.sub.3.sup.-
hco.sub.3.sup.- ⃡ h.sup.+ + co.sub.3.sup.=
each of the reactions depicted above is reversible. The reactions involving carbon dioxide and the carbonate and bicarbonate ions can be biased to the right by raising the partial pressure of carbon dioxide acting on the amine solution above the partial pressure of carbon dioxide of the solution which is proportional to the amount of bicarbonate and carbonate ions present in the solution. This is conveniently done by increasing the amount of carbon dioxide in contact with the solutions, e.g., by increasing the amount of dry ice or gaseous carbon dioxide added to the solution, that is, in general, causing an increase in the partial pressure of carbon dixode acting on the solution. These reactions are forced to the right during the manufacture of the novel cleaning solutions and are forced to the left when the compositions containing the solutions are used. These reactions are conveniently forced to the left by increasing the temperature of the solution or by decreasing the partial pressure of carbon dioxide acting on the solution.
Any water-soluble organic amine as described above can be employed. Preferred amines are those that have low or no irritating or toxic properties and have low or no odor or have a pleasant odor. Illustrative of suitable water-soluble organic amines include those having at least one nitrogen-bonded hydrogen atom per molecule and, preferably, those having at least two nitrogen-bonded hydrogen atoms per molecule. Such illustrative organic amines can be depicted by the formula:
R'R"NH
wherein R' individually can be hydrogen or a monovalent organic group, R" individually can be a monovalent organic group, and both R' and R" together can be a divalent organic group. Preferably, R', when it is organic, and R" are composed of elements selected from the class consisting of carbon, hydrogen, oxygen and nitrogen and most preferably are composed of elements selected from the class consisting of carbon, hydrogen and oxygen. Preferably, R', when organic, and R" are aliphatic or cycloaliphatic and, most preferably, are selected from the class consisting of alkyl, hydroxyalkyl, and, when taken together, alkylene and alkylene-oxy-alkylene. The number of carbon atoms in R', when organic, and R" individually is preferably 1 to 18, most preferably 2 to 16, and, when together, is preferably 3 to 18, most preferably 4 to 10.
Specific water-soluble organic amines include monoethanolamine, diethanolamine, n-butylamine, morpholine, 2-[2-(3-aminopropoxy)ethoxy]ethanol, N(2-hydroxyethyl) ethylenediamine, dihexylamine, diisopropylamine, dipropylamine, cyclohexylamine, ethylenediamine, n-amylamine, trimethylene diamine, phenylenediamine, and the like. The proportion of the CO 2 -neutralized water-soluble organic amine in the novel compositions is not narrowly critical and is conveniently measured by the proportion of the water-soluble organic amine used to produce the novel compositions and available upon decomposition of the novel compositions. The proportion of amine used in producing the novel compositions can range from about 1 wt.% to about 20 wt.%, preferably about 8 wt.% to about 12 wt.%, based on the total weight of the water, amine, and water-soluble solvent, if any, in the composition.
The compositions of this invention can also contain a water-soluble organic solvent to aid in the removal of the unwanted coating such as grease from an oven surface. It should be one having a boiling point above the temperature at which the composition is used, should not adversely affect the other ingredients, should not itself be adversely affected by the other ingredients, should not react with carbon dioxide or interfere with the reaction of carbon dioxide and the amine, and should not present a fire hazard. In many cases, the water-soluble organic solvent has been found to unexpectedly act synergistically with the amine in attacking the unwanted coating. That is, an amine which has little effect on the unwanted coating, when combined according to this invention with certain water-soluble organic solvents which have little or no effect on the unwanted coating, provide compositions that efficiently loosen and/or soften the unwanted coating. In addition to aiding the attack on the unwanted coating, the water-soluble organic solvent, if properly selected, can decrease the rate of evaporation of the amine and water from the unwanted coating to which it is applied. The water-soluble organic solvent can be mixed into composition before or after the water-soluble organic amine is converted to neutral form by treatment with carbon dioxide. It must of course be chosen with regard to its toxicity and compatibility with the other components of the compositions. Odor is of course also a significant consideration, particularly where the solutions are to be used in domestic applications. Suitable organic solvents include alkanols, dialkyl ketones, polyoxyalkylene glycols and alkyl ethers thereof, and alkyl esters of alkanoic acids. Examples of suitable organic solvents are 2-(2-butoxyethoxy)ethanol, triethylene glycol monobutyl ether, triethylene glycol monomethyl ether, a mixture of 70 wt. parts 2-phenoxyethanol and 30 wt. parts 2-(2-phenoxyethoxy)ethanol, 1-butoxy-2-ethoxypropanol, hexylene glycol, tripropylene glycol monomethyl ether, 2-methoxy-1-methylethanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 2-(2-methoxyethoxy)ethanol, 2-methoxyethanol, 2-(2-ethoxyethoxy) ethanol, 2-methyl-2,4-pentanediol, glycerol, ethanol, and butanol.
The proportion of water-soluble organic solvent, if used, is not narrowly critical and can range from about 0 wt.% to about 50 wt.%, preferably from about 5 wt.% to about 20 wt.% based on the total weight of water, amine and water-soluble organic solvent in the novel compositions.
Thickening agents can be used in the compositions of this invention to provide body to the compositions, i.e., to render them more viscous and help them to stick to the surface being cleaned, for example, the walls and ceilings of cooking ovens. The thickening agent should be generally compatible with the other ingredients of the composition and should not adversely affect them or itself be adversely affected by the other ingredients. Suitable thickening agents include colloidal magnesium aluminum silicate (Veegum), hydroxyethyl cellulose, sodium carboxymethyl cellulose, sodium carboxyethyl cellulose, bentonite, alginates, amylopectin starch, carboxy vinyl polymers, xanthan gums, fumed amorphous silica, precipitated silica and the like. The type and amount of thickening agent can be selected to provide a pseudo-plastic composition having a viscosity of between about 300 to about 1500 cps., preferably about 400 to about 900 cps. as determined on a Brookfield LVT viscometer using a No. 2 spindle at 12 rpm.
The proportion of thickening agent, if used, is not narrowly critical and can range from about 0 wt.% to about 10 wt.%, preferably from about 0 wt.% to about 5 wt.% based on the total weight of the water, amine and water-soluble organic solvent, if any, in the novel compositions. The proportion of thickening agent depends largely on the thickening ability of the agent. The thickening agent can be mixed into the composition before or after the water-soluble organic amine is neutralized by treatment with carbon dioxide.
The novel compositions can contain other optional ingredients insofar as they do not interfere with the cleaning ability of the compositions or adversely affect the other ingredients of the compositions.
Surfactants of various kinds can also be added to augment the cleaning power of the compositions. Small amounts of a wax, such as beeswax, scale wax (crude) or paraffin wax, in pulverized form can be added to improve the adherence of the compositions to the unwanted coating desired to be removed. Such waxes are solids at room temperature and soften in the range of 100° F. to 200° F. The novel compositions can be employed as foams in which case foam stabilizers of the well known types are added to the solutions which are then packaged in aerosol containers with suitable propellants.
Carbon dioxide can be used as a propellent when the novel compositions are packaged in aerosol containers and, when so used, also functions to provide a CO 2 atmosphere for maintaining the pH of the compositions at or near neutral. Alternatively, other conventional propellants can also be employed in the aerosol container. Such other propellants include the hydrocarbons such as isobutane and isobutane/propane mixtures, halocarbons such as dichlorodifluoromethane, trichlorofluoromethane, dichlorotetrafluoroethane, and 1,1,2-trichlorotrifluoroethane or mixtures thereof, or any other suitable propellant which is effective at atmospheric temperatures and does not adversely react with any components of the composition. The aerosol container unit consists of a pressure-tight aerosol container having a valve-controlled opening and containing the novel composition as set forth therein and from about 1.00 wt.% to about 25.00 wt.% of a propellant based on the weight of said composition. The aerosol container unit can be adapted to provide a fine spray or foam upon activation of the valve. The novel compositions can be first prepared and then added to the aerosol container or the aqueous solution of the water-soluble organic amine and other ingredients can be added to the aerosol container which can then be pressurized with carbon dioxide to neutralize the amine solution and provide the internal pressure needed to propel the composition from the container. Alternatively, the novel compositions can be packaged in non-aerosol containers, such as jars or bottles, under about one atmosphere of CO 2 .
Treatments of the unwanted coatings to loosen and/or soften same according to this invention can be effected in a variety of ways, the following being typical examples:
(a) Application of the novel composition by means of a sponge, brush or cloth.
(b) Application of the novel composition by means of a hand operated spray bottle or a hand pump or automatically (e.g., by venturi action) by means of a cartridge of compressed gas.
(c) Application of the novel composition in gel or paste form.
(d) Application of the novel composition by means of an aerosol type pressurized dispenser.
The novel composition can be applied to the unwanted coating which is at ambient temperature and allowed to stand thereon at ambient temperature or the temperature can be raised, e.g., to 80° or 90° C. more or less and held there for a period of a few minutes to three or more hours. Alternatively, the temperature of the unwanted coating can be elevated, e.g., to 80° or 90° C., more or less, followed by application of the novel composition and the temperature can be maintained at that level or increased or allowed to decrease. The time required to loosen or soften the unwanted coating sufficiently to facilitate mechanical removal depends largely upon the temperature used and on the stubbornnesss of the unwanted coating to loosening or softening. Even the toughest, unwanted coatings in cooking ovens can usually be loosened or softened sufficiently for removal within 30 minutes, especially at the higher temperatures, to 2 to 3 hours or more at room temperature. If the novel composition applied as an over-coating on the unwanted coating dries out before the unwanted coating has sufficiently loosened or softened, additional amounts of the novel composition can be applied. In general, however, even the toughest coatings in cooking ovens are removed in one application.
After loosening or softening, the loosened or softened unwanted coating can be mechanically removed by washing, scraping, wiping, scrubbing or flushing with water, if feasible, or by any other means available or convenient to the user. The novel composition of this invention, when tested for toxicity and irritation, was found to be not "toxic" by the standard of the Federal Hazardous Substances Act (FHSA) and was found not to be a skin irritant according to the FHSA standards, unlike a popular commercial brand oven cleaner which contained caustic alkali. The commercial brand oven cleaner was found to be considerably more toxic and irritating than the novel composition. The pH's of the novel compositions are initially low and remain relatively low (for example below 10) throughout the operation. This phenomenon was unexpected and indicates that high pH's are not essential to achieve a satisfactory attack on the unwanted coating and that the novel compositions can be substantially as safe during and after the cleaning as they were before it was applied or in the initial stages of application.
The following examples are presented to illustrate the invention. Numbered Examples refer to CO 2 -neutralized organic amine compositions and except as noted, illustrate this invention. Lettered Examples do not refer to CO 2 -neutralized organic amine compositions and thus are not illustrative of the invention claimed herein. Unless otherwise specified, all parts, ratios and percentages are on a weight basis, all temperatures are on the Centigrade scale, and pH's were determined with pH paper. The percent soil removal values given in the examples were determined by visual inspection and estimation of the percentage of the area of baked-on soil removed by the composition being tested. The tests were continued until all baked-on soil could be removed by rinsing in water and wiping with a sponge, or until the composition being tested had dried out.
In the examples, the following designations are used as abbreviations for the following bases:
TABLE 1______________________________________Designation Base______________________________________MEA MonoethanolamineAC Ammonium CarbonateM MorpholineDEA DiethanolamineTEA TriethanolamineNBA N-ButylamineDBA Di-N-ButylamineTPA Tri-N-PropylamineNaOH Sodium HydroxideAH Ammonium HydroxideAPEE 2-[2-(3-Aminopropoxy) ethoxy]ethanolCa(OH).sub.2 Calcium Hydroxide______________________________________
In the examples, the following designations are used as abbreviations for the following solvents:
TABLE 2______________________________________Designation Solvent______________________________________BEE 2-(2-butoxyethoxy) ethanolTBE Triethylene glycol monobutyl etherTME Triethylene glycol monomethyl etherPE Mixture of 70 parts 2-phenoxyethanol, and 30 parts 2-(2-phenoxyethoxy)ethanol,BEP 1-Butoxy-2-EthoxypropanolHG Hexylene GlycolTPM Tripropylene glycol monomethyl etherMME 2-Methoxy-1-methylethanolEG Ethylene GlycolDEG Diethylene GlycolTEG Triethylene GlycolPG Propylene GlycolMEE 2-(2-methoxyethoxy) ethanolME 2-methoxyethanol______________________________________
The "composite soil" used in most of the examples was prepared by mixing the following ingredients in a baking dish:
______________________________________Ingredient Amount (g)______________________________________Peanut oil 90Corn oil 50Cherry pie mix 50Ground beef 50Ground pork 50Corn Syrup 50NaCl 2Water 50______________________________________
The mixture was heated for two hours at 400° F. and then liquid was drained off and separated from the solids. The liquid was used as the composite soil by applying it to and baking it on a surface. This procedure is similar to the one set forth in Proposed Federal Specification P-C-1947 "Cleaning Compound, Oven" (Aerosol--for indoor occupied areas) GAS Jan. 2, 1975 which also includes 2 grams sodium glutamate, but does not contain Corn syrup.
A "carbohydrate soil" is used in some of the following examples and was made pursuant to the above-identified Federal Specification by mixing the following ingredients in a food blender for 10 minutes at 100° F.:
______________________________________Ingredient Amount (g)______________________________________Commercial Cheese Spread 80Dehydrated instant augratin potatoes 80Sugar 160Vegetable oil 23______________________________________
EXAMPLES 1, A AND B
In Example 1, 10 grams of 2-(2-butoxyethoxy)ethanol (BEE), 10 grams of monoethanolamine (MEA) and 80 grams of water were placed in an aerosol can and a valve was affixed to the can. The can was filled with CO 2 and vented three times. The contents then were pressurized with CO 2 gas until the equilibrium interior pressure reached about 90 psig. Whenever the can became warm, it was shaken until it cooled before continuing with the above procedure.
In Example B, a commercial oven cleaner, Dow Oven Cleaner, made by Dow Chemical Company was employed as the cleaning composition. The Dow Oven Cleaner used contained water, 10% glycol ethers, 5% alkanolamines, 4% propellant, 4% sodium hydroxide and less than 1% each of inert cleaning aids, thickener, nonionic surfactants and perfume, according to label.
In Example A, 10 grams of MEA was dissolved in water. Then, 10 grams of BEE was also dissolved in the water to provide a composition containing 10 grams MEA, 10 grams BEE and 80 grams of water.
Each of the compositions of Examples 1, A and B was tested by the following procedure. Glass microscope slides were coated with a thin but thorough coating of "composite soil" and then baked at 246° C. (475° F.) for 1.5 hours. Smooth and even baked soil surfaces were used for subsequent testing. A section broken from a baked, soiled slide was placed in a 50 ml. beaker with the baked, soiled side up. Five grams of the cleaning composition under test was placed on the baked, soiled surface. The beaker was placed in a 90° C. (193° F.) oven and checked every 30 minutes for percentage of soil removal. When 100% of the soil was removed or the cleaning composition had evaporated the test was terminated. The results are given in Table 3 below.
TABLE 3______________________________________ % Soil RemovalExample Base Solvent 1 hr. 1.5 hr.______________________________________1 MEA BEE 75 100A MEA BEE 100 --B DOW OVEN CLEANER* 0 100______________________________________ *Consumer product on market
EXAMPLES 2-7 AND C TO H
In these examples, various amine bases were tested as 10 wt.% mixtures in an aqueous solution containing 10 wt.% BEE. In Examples 2-7, CO 2 was added by adding dry ice to each cleaning composition until the pH was reduced into the range of 7 to 8. The identities of the amines tested and the results obtained expressed in terms of percent of soil removed are given in Table 4 below. The preparation and testing procedures given in Examples 1, A and B were used.
TABLE 4__________________________________________________________________________Percent Soil Removal - Various AminesExample2 3 4* 5 6 7* C D E F G HBase NBA DBA TPA MEA DEA TEA NBA DBA TPA MEA DEA TEA__________________________________________________________________________30 min.0 0 0 0 0 0 100 20 0 50 0 01 hr.0 0 0 100 0 0 100 95 10 100 0 01.5 hrs.50 0 0 100 5 0 100 100 40 100 0 02 hrs.100 0 0 100 25 0 100 100 45 100 0 02.5 hrs.100 0 0 100 30 0 100 100 45 100 0 03 hrs.100 5 0 100 100 0 100 100 45 100 100 03.5 hrs.100 5 0 100 100 0 -- -- -- -- -- --4 hrs.100 5 0 100 100 0 -- -- -- -- -- --__________________________________________________________________________ *Examples 4 and 7 are CO.sub.2 neutralized tertiary amine compositions no within the scope of this invention.
EXAMPLES 8, 9, I AND J
The following compositions given in Table 5 were prepared and tested by the procedure set forth in Examples 1, A and B. In Examples 8 and 9 the respective compositions as given in Table 5 were treated with CO 2 (dry ice) until the pH dropped into the range of 7 to 8. The results obtained expressed percent of soil removed are given in Table 6.
TABLE 5______________________________________Example Ingredients % by Weight______________________________________I APEE 10 H.sub.2 O 90J APEE 10 BEE 10 H.sub.2 O 808 Same as Ex. J + CO.sub.29 Same as Ex. I + CO.sub.2______________________________________
TABLE 6______________________________________Percent Soil RemovalExample I J 8 9______________________________________30 mins. 0 0 0 01 hr. 0 50 50 01.5 hrs. 0 100 95 02 hrs. 5 100 100 52.5 hrs. 50 100 100 103 hrs. 90 100 100 1003.5 hrs. 100 100 100 1004 hrs. 100 100 100 100______________________________________
EXAMPLES K-M
Three compositions were prepared using the procedures of Example 1, A and B and the materials listed in Table 7.
TABLE 7______________________________________ K L M______________________________________Saturated aqueous CaOH solution (g) 100 90 90BEE (g) 0 10 10______________________________________
The composition of M was treated with CO 2 until the pH was lowered to about 7. Each composition was tested pursuant to the procedures given in Example 1, A and B and after 2.5 hours no soil whatsoever had been removed by any of the three compositions.
EXAMPLE N
4.5 wt. parts of NaOH and 95.5 wt. parts water were mixed in a beaker and tested pursuant to the procedures given in Examples 1, A and B. The resulting solution had a pH of 13.8 measured by a pH meter. When tested on glass slides there was 0% soil removal after 1 hour, 70% after 2 hours and 100% soil removal after 3 hours.
Examples 10-12 AND O-T
Ten compositions as described in Table 8 were prepared using the procedures described in Table 9. Porcelainized enamel panels were coated with a thin, but thorough coat of the composite soil described hereinbefore and baked at 246° C. (475° F.) for 1.5 hours. Smooth and even baked soil surfaces were used for subsequent testing. In each case, the cleaning composition was coated onto the baked soiled panel and placed in a 90° C. oven. Each panel was checked periodically for percent of soil removal and the results are correspondingly given in Table 8. The panels are kept in the oven until all soil was removed or until the composition coating dried out.
TABLE 8__________________________________________________________________________Base Solvent Thickener % Soil RemovalEx. Type Amt.(g) Type Amt.(g) Type Amt.(g) H.sub.2 O(g) CO.sub.2 20 mins. 30 mins. 35 mins. 40 mins. 4__________________________________________________________________________ hrs.O MEA 10 TPM 10 V 10 80 76 NO -- 100 -- -- --10 " 10 BEE 10 C 1 80 YES 98 -- -- -- --P DOW OVEN CLEANER 100 -- -- -- --Q -- -- BEE 15 C 2 83 YES -- 0 -- -- --11 MEA 10 BEE 10 V 2 78 YES -- -- 100 -- --R MEA 10 TPM 10 V 1 79 NO -- -- -- 100 --12 M 10 -- -- -- -- 90 YES -- -- -- 100 --S NaOH 7 TPM 10 V 1 82 NO -- -- -- 100 --T " 7 " 10 V 1 82 YES -- -- -- 0 --__________________________________________________________________________ V designates Veegum T, a colloidal magnesium aluminum silicate made and sold by R. T. Vanderbilt Co., Inc. C designates a hydroxyethyl cellulose having a viscosity, as a 2 wt. % aqueous solution, of 5401 to 6100 cps as determined at 25° C. on a Brookfield LVT Viscometer at 60 rpm using a #4 spindle. --designates no measurement made
TABLE 9______________________________________Example Preparation______________________________________O The base, solvent and water were mixed and heated to 60 to 70° C. Then the mixture was vigorously stirred and the thickener was added.10 The base, solvent and water were mixed in a beaker and dry ice (solid CO.sub.2) was added until the pH (measured with pH paper) was reduced to 8 or lower. Thereafter, the composition was placed in a Waring blender and whipped while adding the thickener. The resulting composition was placed in an eight-ounce, double-lined aerosol can (vinyl/epoxy) and a valve (4 inch × 0.025 inch stem and 0.080 inch body was affixed). The can and contents were pressurized with CO.sub.2 gas until the internal pressure reached 90 psig. The can was vented and pressurized three times before final pressurizing to 90 psig. A 0.020 inch actuator was then attached to the valve.P Dow Oven Cleaner purchased at random.Q The solvent and water were mixed and placed in a Waring blender and whipped while adding the thickener. The resulting composition was packaged in an aerosol can in the manner described in Example 10.11 The water was heated to 50 to 60° C. and placed in a Waring blender. The blender was turned on "low" and the thickener was sprinkled in. Thereafter, the base and solvent were added while the blender agitated the mixture and thereafter the blender was turned on "high" for two minutes. The resulting composition was packaged in an aerosol container in the manner described in Example 10 except that whenever the can became warm during pressurization with CO.sub.2 gas it was shaken until cooled to room temperature before continuing with the pressurization.R The water was heated to 50 to 60° C. and placed in a Waring blender. The blender was turned on "low" and the thickener sprinkled in. There- after, the base and solvent were added while the blender was on and then the completed composition was mixed on "high" for two minutes. The same procedure as used in Example R was employed except that chunks of solid CO.sub.2 were added to the finished composition in the Waring blender until the pH was reduced to 8 or below.S The procedure described in Example R was used.T The procedure described in Example 12 was used.______________________________________
EXAMPLES 13, 14 AND U
Seven compositions as described in Table 10 were prepared using the procedures described in Table 11. Porcelainized enamel test panels soiled as described in Examples 10-12 and O-T were used. Smooth and even cured surfaces were used for testing. Prior to coating with each composition, each panel was warmed in a 90° C. oven. Thereafter, it was coated with the composition under test, placed in a 90° C. oven and periodically visually checked for percent soil removal. The results are given in Table 10. The panels were kept in the oven until all soil was removed or until the composition coating dried out.
TABLE 10__________________________________________________________________________Base Solvent Thickener % Soil RemovalExampleType Amt. (g) Type Amt. (g) Type Amt. (g) H.sub.2 O (g) CO.sub.2 15 mins. 20 mins. 30 mins.__________________________________________________________________________13 MEA 10 TPM 10 -- -- 80 YES -- -- 25U DOW OVEN CLEANER -- -- -- -- -- NO 25 -- --14 MEA 10 BEE 10 V 19 80 YES -- 20 8010 MEA 10 BEE 10 C 1 80 YES -- 98 --__________________________________________________________________________ V designates Veegum T, a colloidal magnesium aluminum silicate made and sold by R.T. Vanderbilt Co., Inc. C designates a hydroxyethyl cellulose having a viscosity, as a 2 wt.% aqueous solution, of 5401 to 6100 cps as determined at 25° C. on a Brookfield LVT Viscometer at 60 rpm using a #4 spindle. --designates no measurement made
TABLE 11______________________________________Example Preparation______________________________________13 The base, solvent and water were mixed together and then placed in an aerosol can and pressurized pursuant to the procedure described in Example 10 with the exception that, when- ever the can became warm, it was shaken until cooled to room temperature before continuing with the pressurization.V Dow Oven Cleaner14 The base, solvent and water were mixed and heated to 50 to 60° C. Solid CO.sub.2 was added until the pH was reduced to 8 or less. Thereafter, the composition was placed in a Waring blender and whipped while adding the thickener.10 See Table 9.______________________________________
EXAMPLES 15 and V
The composition of Example V was prepared by mixing 15 grams BEE and 83 grams of water in a beaker. Thereafter, the mixture was placed in a Waring blender and whipped while two grams of a hydroxyethyl cellulose thickner were added. The resulting composition was packaged in an aerosol container using the procedure described for Example 10, Table 9.
The composition of Example 15 was prepared by mixing 28.5 grams of water and 10 grams of monoethanolamine and adding solid CO 2 until the pH was reduced to 8 or less. 50 grams of water were heated to 50 to 60° C. and placed in a Waring blender. The blender was turned on "low" and the thickener was sprinkled in. While agitating the mixture of water and thickener, 10 grams of BEE were added. Then, the mixture of base and water treated with CO 2 were added to the blender while continuing agitation. Thereafter, the resulting composition was whipped on "high" in the blender for two minutes. The resulting composition was packaged in an aerosol container in the manner described for Example 10 in Table 9.
In each instance, the two above-mentioned compositions were tested on porcelainized enamel panels soiled with the composite oven soil. The soiled panels were prepared in the same manner as the soiled panels described in Examples 10-12 and O-T. After the panels were coated with the cleaning composition, they were allowed to stand at room temperature and observations were made periodically for percent soil removal. The composition of Example V provided 0% soil removal after 48 hours. The composition of Example 15 provided 100% solid removal after 17 hours.
EXAMPLES 16 and W
Two identical compositions were made, each containing 10 grams monoethanolamine (MEA), 10 grams of BEE and 80 grams of water. In the composition of Example 16 the above-mentioned mixture was neutralized with solid CO 2 to a pH of 8 or less whereas the composition of Example W was not.
5 grams of each resulting cleaning composition was placed in a 50 ml. beaker which was then placed in a 90° C. oven. The pH of each mixture in the oven was taken periodically and the results are given in Table 11 below.
Every 30 minutes one ml. of water was added to each mixture to replace evaporated water. These Examples illustrate the substantial effectiveness of the present invention in maintaining the pH of the cleaning composition well below 10 while it is being used in a typical manner to clean an oven. The results are plotted in the graph of the drawing.
TABLE 12______________________________________ pH ComparisonExample W 16______________________________________0 hrs. 11.6 7.830 mins. 11.5 9.51 hr. 11.4 9.62 hrs. 11.0 9.73 hrs. 10.8 9.9______________________________________
EXAMPLES 17 AND X
In the case of Example 17, a composition was prepared containing 10 grams of monoethanolamine (MEA), 10 grams of BEE and 80 grams of water. Carbon dioxide was added to saturate the composition and reduce its pH to a range of 7 to 8. The composition of X was Dow Oven Cleaner which is a commercial product. The two compositions were tested on porcelainized enamel panels which were coated with the "carbohydrate soil" described hereinabove and baked on the panels at 191° C. for two hours.
Two sets of tests were conducted. In the first set, the soiled panels were at room temperature when coated with the compositions of Examples 17 and X. They were then placed in a 100° C. oven and observations of percent soil removal were made. The results of these observations are given in Table 13 below.
In the second set, the soiled panels were first heated to 100° C. before the compositions of Examples 17 and Z were coated onto them. After coating, the panels were heated in a 100° C. oven and observations were made of the percent soil removal. The results are given in Table 13 below.
TABLE 13______________________________________% Soil Removal______________________________________Panels initially coolMinutes X 1730 90 5045 95 85Panels initially hotMinutes______________________________________ X 1730 98 7545 98 98.______________________________________
EXAMPLE 18
A composition was prepared containing 10 grams monoethanolamine (MEA), 10 grams of BEE, 78.5 grams water and 1.5 grams colloidal magnesium aluminum silicate using the procedure described in Example R. Thereafter, solid CO 2 was added until the composition was saturated at one atmosphere at room temperature. This took about 9.5 grams of CO 2 . 96 wt. parts of the composition and 4 wt. parts of isobutane propellant were charged into an aerosol container in a typical manner. The resulting oven cleaning composition was quite effective, contained no caustic alkali and was not a skin irritant based on animal tests whereas a leading caustic alkali-containing oven cleaner on the market had to be classified as a skin irritant pursuant to FHSA definition. Additionally, the composition of Example 18 was considerably less irritating to the eye according to animal testing than a leading caustic alkali-containing oven cleaner on the market. The composition of Example 18 was found to be not toxic, by FHSA definition, following acute peroral or covered dermal routes of administration. The substantially saturated vapor evolved from the composition of Example 18 at room temperature under static conditions was not toxic by FHSA standards and products resulting from heating the composition of Example 18 at 85° C. for two hours and twenty-five minutes did not kill test animals (rats) after that period of exposure. Overall, the commercial caustic alkali-containing oven cleaner tested was found to be considerably more toxic and irritating than the composition of Example 18 with the exception of inhalation results in which both cleaners were found to be non-toxic.
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Organic coatings or deposits are removed from a surface, such as an oven surface, by applying to the coating an aqueous composition containing a primary or secondary amine neutralized with an amount of carbon dioxide in the composition sufficient to cause the composition to have a pH of 10 or less, subjecting the applied composition to conditions whereby partial pressure of carbon dioxide acting on the composition is less than the partial pressure of carbon dioxide in the composition at the temperature of use, and thereafter mechanically removing the coating. The composition may optionally contain a water-soluble organic solvent or a thickening agent.
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FIELD OF THE INVENTION
[0001] This invention relates to motor vehicles that are capable of transporting a large number of people at one time, school busses being prime examples. More particularly, the invention relates to the electrical systems of such vehicles that are equipped with post-trip inspection alert systems for alerting responsible persons, such as school bus drivers, to walk to the rear of their busses at the end of each trip during which pupils have been transported to make sure that none remain inside, and continuing the alert for some interval of time so long as a device at the rear of a bus fails to be manually operated after the end of a pupil-carrying trip so to alert not only the bus driver but also anyone else in the immediate vicinity that a responsible person has not walked to the rear of the vehicle to check for pupils left on board.
BACKGROUND OF THE INVENTION
[0002] Certain motor vehicles that transport people in substantial numbers at one time, such as school busses, are required by law and/or regulation to comply with certain requirements related to the well-being of the people they transport, school pupils in the case of school busses. A typical school bus has a front entrance/exit door at a side of the vehicle opposite the driver's seat, and a center aisle running from front to rear with a row of seats along each side of the aisle.
[0003] As a school bus is preparing to stop to pick up or drop off pupils at various locations along a route, it gives certain signals to other vehicles in the immediate vicinity as an indication that it is coming to a stop for a pick-up. The driver may operate one or more switches to begin flashing certain exterior lamps and/or deploy stop signs at the sides of the bus, or such signals may be issued automatically in one way or another based on conditions indicating that the bus is about to stop for a pick-up or drop-off.
[0004] Once the bus has been brought to a complete stop, the front entrance/exit door is opened to allow pupils to board or exit the bus. After the pupils have entered and seated themselves, or alternatively exited, the door is closed. After that, the flashing lamps are extinguished, the deployed stop signs are retracted, and the bus proceeds to the next stop.
[0005] Upon the last pupil or pupils having been dropped off, the bus typically proceeds to its final destination which may be on school premises or in a parking yard for school busses not necessarily on the premises of any school.
[0006] A number of incidents have been publicly documented where one or more pupils have been left inside a bus after the bus has been parked and the driver has left. These are situations that obviously should not have occurred, but for whatever reason or reasons, actually did.
[0007] In efforts to minimize the risk that such incidents might occur in the future, it has been proposed to equip the electrical systems of school buses with systems for alerting responsible persons, chiefly the bus driver, to walk to the rear of the bus at the end of each trip during which pupils have been transported to make sure that none remain inside. Such systems typically rely on the manual actuation of a device near the rear of the bus as an indication that a responsible person has in fact walked to the rear of the bus.
[0008] Upon the bus being parked at the end of a trip, a typical system will give an alarm of some sort to alert the driver and possibly other individuals in the immediately vicinity of the need to check the bus for any remaining pupils. If the device at the rear of the bus continues not to be manually actuated within some interval of time after the bus has been parked and the motor shut off, the alarm will continue. In some systems, the driver is given the option of delaying the alarm for a limited time after the expiration of which the failure to have actuated the device at the rear of the bus will cause the alarm to be given.
[0009] U.S. Pat. Nos. 5,128,651, 5,874,891, 6,107,915, and 6,259,358 B1 and US Patent Application Publication No. 2003/0030550 A1 describe various systems that require manual actuation of a device at the rear of a bus as an indicator that a responsible person has walked to the rear to check for any persons remaining on the bus after they should have de-boarded. They disclose various conditions for arming and disarming the systems, various conditions for triggering alarms, and various conditions for allowing alarms to be turned off.
[0010] In some systems like that of U.S. Pat. No. 5,128,651, operation of the vehicle's ignition switch to OFF position is effective to give an alarm. U.S. Pat. No. 5,128,651 allows for the ignition switch to be turned from OFF to ON to silence an alarm without having to manually operate a device at the rear of the bus, but when the ignition switch is again turned to OFF, the alarm will be given and can be shut off only by manual actuation of the device at the rear of the bus.
[0011] The system of U.S. Pat. Nos. 5,874,891 allows the driver to deactivate the alarm system with the engine still running (ignition switch in ON) by walking to the rear of the bus and then manually actuating the device at the rear. While that is alleged to be a convenience to the driver, U.S. Pat. No. 5,128,651 seems to consider that possibility undesirable because it would allow any pupil, either on the pupil's own initiative or on instruction from the driver, to deactivate the system by manually operating the device at the rear while the driver remains driving the bus.
SUMMARY OF THE INVENTION
[0012] The present invention relates to a system and method for alerting responsible personnel to perform a post-trip inspection check for passengers remaining on the bus at the end of a trip. The invention requires that the ignition switch be in the ACCESSORY position in order for the system, once armed, to be rendered capable of being disarmed by actuation of a disarming device at the rear of the bus. Because a key-operated ignition switch can be operated only by a key, the invention minimizes the risk that the disarming device at the rear can disarm the system in the absence of a responsible person like the bus driver being present.
[0013] A preferred embodiment of the invention enables the disarming device to disarm the system when the ignition switch is in ACCESSORY position, and that is considered especially desirable because it enables disarming after the bus has been parked and the motor turned off, but still requires presence of a responsible person who has the ignition key, like the bus driver.
[0014] Accordingly, one general aspect of the invention relates to a bus comprising a motor that propels the bus and that is turned on and off by an ignition switch that is selectively operable to at least OFF, IGNITION, and ACCESSORY positions and a bus body comprising an interior and an exterior.
[0015] A driver's seat is at one side of the interior at a front of the body, and an entrance/exit door is at the other side opposite the driver's seat for allowing passengers to board and exit when open.
[0016] An aisle runs rearward from the front, and passenger seats are adjacent the aisle.
[0017] An electrical system of the bus comprises: signaling devices on the exterior of the bus body that, when activated, signal that the bus is stopping to allow passengers to enter or exit; one or more alert devices for giving alerts within and immediately surrounding the bus; and an electrical system controller (ESC) that processes data from various sources to provide output data for performing certain functions incidental to operation of the bus via various virtual controllers in the ESC.
[0018] One virtual controller controls the alert devices by processing data indicating status of the entrance/exit door, data indicating status of the signaling devices, data indicating status of the ignition switch, and data indicating status of a disarming device disposed proximate a rearmost passenger seat.
[0019] The one virtual controller: is set from an UNARMED state to an ARMED state upon processing data disclosing concurrence of the ignition switch being in IGNITION position, the door being open, and the signaling devices being active; is set from the ARMED state to a TRIGGERED state upon processing data disclosing concurrence of the ignition switch being in OFF position and the signaling devices not being active; is set from the TRIGGERED state to a SNOOZE state upon processing data disclosing concurrence of the ignition switch being in the ACCESSORY or IGNITION position and a snooze switch being pressed; and is rendered capable of being reset from TRIGGERED and SNOOZE states to the UNARMED state upon processing data disclosing concurrence of operation of the disarming device and of the ignition switch being in the ACCESSORY position.
[0020] A more specific aspect is that the one virtual controller, is rendered capable of being reset from TRIGGERED and SNOOZE states to the UNARMED state upon processing data disclosing concurrence of operation of the disarming device and of the ignition switch being in ACCESSORY position, and is actually reset to the UNARMED state when the processing of data discloses concurrence of operation of the disarming device, of the ignition switch being in ACCESSORY position, and of a park brake of the bus being applied.
[0021] Another general aspect of the invention relates to a method for alerting responsible personnel to perform a post-trip inspection check for passengers remaining on the bus at the end of a trip.
[0022] Still another aspect relates to how operation of the disarming device is indicated to the one virtual controller. Specifically, operation is indicated by a correct operational sequence of non-actuated, then actuated, and then non-actuated.
[0023] Still another aspect relates to a snooze feature that allows the driver to silence an alert that is given during a trip due to the motor being temporarily shut off before the trip is resumed. Silencing the alert in this way does not defeat the system because if the bus does not resume the trip within a predetermined amount of time, the system reverts to TRIGGERED state. Resuming the trip before reversion to TRIGGERED state prevents expiration of a snooze timer would otherwise resets the system to TRIGGERED state upon expiring.
[0024] The foregoing, along with further aspects, features, and advantages of the invention, will be seen in the following disclosure of a presently preferred embodiment of the invention depicting the best mode contemplated at this time for carrying out the invention. The disclosure includes drawings, briefly described as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] FIG. 1 is a general schematic diagram of portions of a school bus electrical system relevant to principles of the present invention.
[0026] FIG. 1A is a top plan view of the layout of a typical school bus.
[0027] FIG. 2 is a general schematic diagram of the inventive post-trip inspection alert system including a virtual controller that receives input data, processes data, and issues output data.
[0028] FIG. 3 is a diagram showing various operational states for the inventive post-trip inspection alert system.
[0029] FIG. 4 is a general software strategy diagram for use in describing an implementation of an algorithm in the virtual controller for selectively placing the inventive post-trip inspection alert system in the various operational states.
[0030] FIG. 5 is a more detailed software strategy diagram that that describes a DISABLED state of the algorithm and an UNARMED state of the algorithm.
[0031] FIG. 6 is a more detailed software strategy diagram that describes an ARMED state of the algorithm.
[0032] FIGS. 7A and 7B together are a more detailed software strategy diagram that describes a TRIGGERED state of the algorithm.
[0033] FIGS. 8A and 8B together are a more detailed software strategy diagram that describes a SNOOZE state of the algorithm.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0034] FIG. 1A shows a school bus 10 comprising a body 12 mounted on a chassis that comprises a motor 14 for propelling the bus. On its interior, body 12 has a driver's seat 16 at the left front and an entrance/exit door 18 (shown open) at the right front opposite seat 16 . A steering wheel 20 and instrument cluster 22 are in front of seat 16 .
[0035] Bus 10 comprises an electrical system 23 that may comprise separate body and chassis system controllers that can communicate with each other, or alternatively a single system controller. For purposes of the present disclosure, bus 10 is considered to have a body electrical system controller (ESC) 24 (see FIG. 1 ) that exercises control over certain equipment of body 12 that includes a city horn 26 , headlamps 28 , 30 , a cluster alarm 32 , pupil warning lamps 34 , 36 , and deployable stop signs 38 , 40 (shown deployed).
[0036] FIG. 1A further shows body 12 to have a center aisle 42 running rearward from the front of the body and rows of passenger seats 44 adjacent either side of aisle 42 . Body 12 also comprises a rear emergency exit door 45 at the rear end of aisle 42 .
[0037] FIG. 1 shows various inputs to ESC 24 that include a disarm input 46 , an ignition switch 47 , a park brake input 48 , a pupil warning input 50 , a door open input 52 , and a snooze input 53 .
[0038] General principles of the invention can be understood by considering FIGS. 2 and 3 in light of the following description.
[0039] The programming of ESC 24 with an algorithm according to the present invention creates a unique virtual controller 54 shown in FIG. 2 .
[0040] Various input data processed by a processor of ESC 24 during iterations of the algorithm may be considered as inputs to virtual controller 54 . The various input data shown in FIG. 2 are designated:
BUS_Post_Trip_Insp_Switch, Accessory_Signal, Ignition_Signal, BUS_PTI_Snooze_Switch Park_Brake_Signal, BUS_Door-Open_Cmd, BUS_PWL_Active_Flag, BUS_LT_RED_PWL_Req, and BUS_RT_RED_PWL_Req.
[0050] Various output data that result from processing performed by the processor during iterations of that algorithm may be considered as outputs of virtual controller 54 . The various output data shown in FIG. 2 are designated:
Low_Beam_Override_Req, Elec_City_Horn_Req_Sem, EGC_Alarm_AlwaysBeep-Req, and EGC_Alarm_ 1 ShortBeep-Req.
[0055] Ignition switch 47 functions to turn motor 14 on and off and is disposed in or near cluster 22 . A key is required to operate ignition switch 47 selectively to ACCESSORY, OFF, IGNITION, and CRANK positions. The IGNITION position may sometimes be referred to as ON position. The key is typically inserted into the switch when the switch is in OFF position. Turning the inserted key counterclockwise from OFF position places the switch in ACCESSORY position. Turning the inserted key clockwise from OFF position places the switch first in IGNITION, or ON, position. Turning the key still farther clockwise against a return spring places the switch in CRANK position for cranking motor 14 at starting. Typically the key can be physically removed from the switch only in OFF position.
[0056] The data input Ignition_Signal and Accessory_Signal are derived from ignition switch 47 . Ignition_Signal, when true, indicates to virtual controller 54 that ignition switch 47 is in either IGNITION or CRANK position. The data input Accessory_Signal, when true, indicates to virtual controller 54 that ignition switch 47 is in either ACCESSORY or IGNITION position.
[0057] When ignition switch 47 is in either OFF or ACCESSORY position, motor 14 is off. When ignition switch 47 is in IGNITION position, the motor 14 is either running after having been cranked and started, or is enabled to run if cranked. When ignition switch 47 is in IGNITION position, both Ignition_Signal and Accessory_Signal are true, but when ignition switch 47 is in ACCESSORY position, only Accessory_Signal is true. When ignition switch 47 is in OFF position, neither Ignition_Signal nor Accessory_Signal is true. By processing both Ignition_Signal and Accessory_Signal, virtual controller 54 can distinguish each of the three positions, ACCESSORY, OFF, and IGNITION.
[0058] BUS_Post_Trip_Insp_Switch is an element of the disarm input 46 . When a disarming device at the rear of the bus, such as an existing switch 45 S associated with a lever that can be selectively positioned to bar and unbar rear door 45 , or alternatively a devoted switch near the rear door, operates from a non-actuated state to an actuated state, BUS_Post_Trip_Insp_Switch operates from false to true. Depending on the specific switch, the switch may be a normally open switch that is closed when actuated, or a normally closed switch that is open when actuated. The switch is typically spring-biased. Again depending on the particular switch, actuation may occur by depressing the switch actuator against the spring-bias or by releasing the switch actuator to allow the spring-bias to operate the switch from non-actuated to actuated. BUS_Post_Trip_Insp_Switch corresponds to disarm input 46 .
[0059] Park_Brake_Signal is derived from a source named Park_Brake_Ind 48 and is true when a park brake of the bus is being applied. The park brake is typically applied after the bus has been parked at the end of a trip. Park_Brake_Signal and Park_Brake_Ind correspond to park brake input 48 .
[0060] BUS_Door Open_Cmd is derived from a source BUS_Door_Control 52 and is true when the bus driver is requesting that door 18 be open. This is one of alternate ways to signal door opening. Another way would be by using a door switch at the door to signal door open and door closed. BUS_Door_Control and BUS_Door_Open Cmd correspond to Door Open Input 50 .
[0061] BUS_PWL_Active_Flag is derived from a source designated BUS_PWL_Flash_Processor. It is true when the a pupil warning is being given. In the particular embodiment shown in FIG. 1A , pupil warning is given by the flashing of lights 34 , 36 and the deployment of stop signs 38 , 40 .
[0062] BUS_LT_RED_PWL_Req and BUS_RT_RED_PWL_Req are derived from a source designated Bus_Pupil_Warning_Lght_Handler and are true when the driver is requesting pupil warning either by actuation of a devoted switch or by some other action.
[0063] In case certain lamps used for signaling pupil warning may flash at times other than for pupil warning, the processing of BUS_PWL_Active_Flag assures that flashing of the lights is due to pupil warning and not some other function. Collectively, BUS_LT_RED_PWL_Req, BUS_RT_RED_PWL_Req, and BUS_PWL_Active_Flag correspond to pupil warning input 50 .
[0064] BUS_PTI_Snooze_Switch is derived from a snooze push-button switch 57 located in or near cluster 22 and corresponds to snooze input 53 in FIG. 1 . BUS_PTI_Snooze_Switch is true when switch 57 is being actuated, i.e. switch actuator being pressed.
[0065] Low_Beam_Override_Req is effective through a headlights handler 59 , and when true, is requesting headlamps 28 , 30 to operate at low beams.
[0066] Elec_City_Horn_Req_Sem is effective through a horn handler 61 , and when true, requests horn 26 to sound.
[0067] EGC_Alarm_AlwaysBeep_Req is effective through an alarm handler 63 , and when true, requests cluster alarm 32 to continually sound, i.e. continually beep.
[0068] EGC_Alarm_ 1 ShortBeep_Req is effective through handler 63 , and when true, requests cluster alarm 32 to sound once for a short time and then stop, i.e. beep once.
[0069] FIG. 3 shows a succession of operational states of the inventive post-trip inspection alert system beginning with a DISABLED state 100 followed in succession by an UNARMED state 102 , an ARMED state 104 , and a TRIGGERED state 106 . When snooze switch 57 is actuated while the system is in the TRIGGERED state, the system switches to a SNOOZE state 108 .
[0070] The system transitions from one state to another depending on the status of various input signals to virtual controller 54 . Virtual controller 54 is created by an algorithm that is programmed in the processor of ESC 24 , hence the adjective “virtual”. Once the algorithm is first enabled, such as when the ignition switch is turned to a position other than OFF, the algorithm begins its first iteration at a start point 110 with the presumption that the system is in DISABLED state 100 . If the status of the park brake is good, the system state advances to the UNARMED state 102 . Presuming that the bus will be embarking on a passenger-transporting trip, the system will remain in UNARMED state 102 until such time as virtual controller 54 detects that passengers are being transported. Transportation of passengers is indicated to virtual controller 54 by concurrence of a pupil warning provided by pupil warning input 50 and opening of entrance/exit door 18 provided by door open input 52 , whereupon the system state advances from UNARMED state 102 to ARMED state 104 .
[0071] The system remains in ARMED state 104 until such time as motor 14 is turned off and any pupil warning has ceased. Typically that will occur at the end of a passenger trip after all passengers have de-boarded. At that time the system is set from ARMED state 104 to TRIGGERED state 106 by virtual controller 54 processing data disclosing concurrence of motor 14 being turned off provided by ignition switch 47 and the pupil warning devices not being active.
[0072] Upon entering TRIGGERED state 106 , virtual controller 54 starts a timing function and also issues a low-level alert intended to remind the bus driver to check the bus for any pupils who for whatever reason may still be in the bus. The low-level alert comprises cluster alarm 32 beeping continually and headlamps 28 and 30 flashing low beams. The timing function allows the bus driver an appropriate amount of time, approximately one minute for example, to walk along aisle 42 to the rear of the bus and actuate switch 45 S.
[0073] Upon processing data disclosing that switch 45 S has not been actuated within the allotted one minute time after the onset of TRIGGERED state 106 , virtual controller 54 then causes one or more alert devices to give a high-level alert. A high-level alert is more prominent than the low-level alert and is intended to cover a larger area, not only inside the bus, but in the immediate vicinity surrounding the bus, to alert others who may be present in the vicinity besides the driver that the bus has not been checked to assure that all pupils are off the bus. The high-level alert comprises not only continued flashing of the headlamps, but further includes honking horn 26 . For example, a high-level alert may be given for up to ten minutes more after the one-minute low-level alert.
[0074] The system is capable of being placed in SNOOZE state 108 from TRIGGERED state 106 upon virtual controller 54 processing data disclosing concurrence of actuation of snooze switch 57 and of ignition switch 47 being in either ACCESSORY or IGNITION position.
[0075] The system is capable of being reset from both TRIGGERED state 106 and SNOOZE state 108 to UNARMED state 102 upon virtual controller 54 processing data disclosing concurrence of actuation of disarming switch 45 S and of ignition switch 47 being in ACCESSORY position. However, according to the disclosed preferred embodiment of the invention, actual resetting to UNARMED state 102 is also conditioned on the park brake also being set. By requiring that ignition switch 47 be in ACCESSORY position, it is assured that motor 14 has not been re-started after having been shut off, and that a key is present in the ignition switch. Consequently, the system cannot be disarmed by merely actuating the disarming device, i.e. switch 45 S. The ignition switch must also be turned to ACCESSORY position at the time that the disarming device is actuated, and in the disclosed embodiment the still further condition that the park brake be set must also be satisfied.
[0076] If the system remains in TRIGGERED state 106 for a certain amount of time without the disarming device being operated, the timing function, which continues after time allotted to the TRIGGERED state (i.e. one minute low-level alert, ten minutes high-level alert), will eventually shut off the alert devices that are giving the high-level alert so as not to drain the bus batteries.
[0077] In case the parking brake is indicated as possibly faulty, by a “bad status” for example, the system is placed in DISABLED state 100 . A ‘bad status’ input to virtual controller 54 is depicted as a fault in the park brake module. The fault can range from a sensor input error to a brake system failure.
[0078] FIG. 4 depicts steps of the algorithm that creates virtual controller 54 .
[0079] Various parameters are instrumental in execution of the algorithm. Parameters already mentioned include: BUS_Post Trip_Insp_Switch, Accessory_Signal, Ignition_Signal, BUS_PTI_Snooze_Switch, Park_Brake_Signal, BUS_Door Open_Cmd, BUS_PWL_Active_Flag, BUS_LT_Red_PWL_Req, and BUS_RT_Red_PWL_Req. Further parameters include: BUS_PTI_Ignition_Off_Delay Timer, BUS_Post Trip_Alarm_Timer, BUS_Post_Trip_Alert_Timer, and BUS_PTI_Snooze_Timer which provide respective timing functions that will be eventually explained. BUS_Post_Trip_Lag_Flag, BUS_Post_Trip-Timer_Flag, BUS_Post_Trip_Button_Pushed_Flag, and BUS_Post_Trip_Alert_Flag are respective flags that can be set and reset. The purposes of the various flags will also be eventually explained. Bus_Post_Trip_Alarm_State indicates one of the possible system states: DISABLED, UNARMED, ARMED, TRIGGERED, and SNOOZE.
[0080] The algorithm repeatedly iterates at an appropriate frequency which may be constant or variable depending on processing priorities. After its start 500 , the algorithm executes a first step 501 that determines the park brake status. If the status is “bad”, meaning consistently bad for the past five seconds for example, the system will not operate except to remain in DISABLED state 100 as indicated at step 502 . The Post Trip Alarm, Post Trip Alert, and PTI Snooze timing functions are stopped, and the Bus Post Trip Lag Flag is reset. Thereupon execution of the algorithm stops (step 503 ) until the next iteration is requested.
[0081] Whenever a subsequent execution of the algorithm discloses that park brake status is not “bad”, a step 504 determines the state of the system, which is still DISABLED state 100 as indicated by Bus_Post_Trip_Alarm_State. Consequently, the algorithm executes according to steps shown FIG. 5 .
[0082] FIG. 5 shows that during a step 505 , BUS_Post_Trip_Alarm_State is set to UNARMED state 102 , and EGC_Alarm_ 1 ShortBeep_Req is set true causing cluster alarm 32 to give one short beep that is intended to inform the driver that the system is now UNARMED.
[0083] A subsequent step 506 checks the status of ignition switch 47 . If Accessory_Signal and Ignition_Signal are both false, ignition switch 47 is indicated in OFF position, resulting in a step 507 that sets Send_Flag_ 61207 . The purpose of Send_Flag_ 61207 will be eventually explained. Thereafter the algorithm continues in UNARMED state 102 to a step 508 .
[0084] When step 506 discloses that ignition switch 47 is not in OFF position, the system remains in UNARMED state 102 and the algorithm continues directly with step 508 , the difference being that step 507 is omitted so that Send_Flag_ 61207 is not set.
[0085] Step 508 stops two timing functions BUS_Post_Trip_Alarm_Timer, and BUS_Post_Trip_Alert_Timer (meaning the timing functions stop counting down), and resets the BUS_Post_Trip_Lag_Flag.
[0086] A step 509 determines the status of door 18 and the pupil warning signal and causes the system to remain in UNARMED state 102 as long as door 18 is not open at the same time as a pupil warning is being given, and as long as a pupil warning is not being given at the same time that the door is open. If the door is not open and the pupil warning is not being given, then that iteration of the algorithm stops.
[0087] When the algorithm next iterates, it repeats steps 501 and 504 , but after step 504 executes a step 511 to determine if the system is in UNARMED state 102 . As long as UNARMED state 102 continues, steps 508 and 509 follow step 511 and the algorithm then stops until the next iteration.
[0088] Whenever step 509 determines that door 18 is open while pupil warning is being given, a step 510 is performed setting BUS_Post_Trip_Alarm_State to ARMED state 104 . When the algorithm next iterates, step 511 will be followed by a further step 512 . With the system now in ARMED state 104 , the sequence of steps shown in FIG. 6 is performed.
[0089] A first step 513 in FIG. 6 determines the status of ignition switch 47 to ascertain if it is still in IGNITION position or if it has been operated out of IGNITION position. As long as ignition switch 47 is still in IGNITION position, a subsequent step 514 determines if BUS_PTI_Ignition_Off_Delay_Timer has expired, meaning having timed out. As long as that timer has not expired, BUS_Post_Trip_Lag_Flag is reset (step 515 ). A step 516 then determines if the Ignition_Signal is “back on”, meaning simply is the switch in IGNITION position.
[0090] If ignition switch 47 is in IGNITION position, a step 517 stops BUS_PTI_Ignition_Off_Delay_Timer. A subsequent step 518 determines if BUS_Post_Trip_Lag_Flag is set and not new (meaning not newly set during this iteration of the algorithm) and if the pupil warning is not being given. If either the flag is not set or pupil warning is being given, the algorithm stops to await the next iteration. Should both the flag be set and not new and pupil warning not be also given, a step 519 sets BUS_Post_Trip_Alarm_State to TRIGGERED, starts BUS_Post_Trip_Alarm_Timer, resets BUS_Post_Trip_Timer_Flag, and resets BUS_Post_Trip_Button_Pushed_Flag, after which this iteration of the algorithm stops.
[0091] Had step 513 disclosed that the Ignition_Signal was off and new, the algorithm would have performed a step 520 before the algorithm advanced to step 514 . Step 520 comprises starting BUS_PTI_Ignition_Off_Delay_Timer. The delay is defined by a parameter BUS_PTI_Ignition_Off_Delay_Const, and in the embodiment shown the length of the delay is 0.5 second.
[0092] Had step 514 disclosed that the BUS_PTI_Ignition_Off_Delay_Timer had expired, it would have set BUS_Post_Trip_Lag_Flag at a step 521 before the algorithm advanced to step 516 .
[0093] The purpose of BUS_PTI_Ignition_Off_Delay_Timer can now be explained. As the algorithm executes, some of the data that it processes each time that it executes is obtained from “snapshots”. In electrical and electronic systems, data taken by one snapshot may not be the true data for any one or more of various reasons, such as electrical noise, a momentary random event such as an interrupt, etc. In the case of ignition switch 47 , the act of turning the switch from IGNITION position to OFF or ACCESSORY position will result in Ignition_Signal changing from true (i.e., on) to false (i.e., off). In order to assure that the switch has in fact been operated from IGNITION, the BUS_PTI_Ignition_Off Delay_Timer is started by step 520 when step 513 first discloses that Ignition_Signal has changed from true to false. BUS_PTI_lgnition_Off_Delay_Const is a programmable parameter that sets the amount of time to be timed, 0.5 seconds as mentioned.
[0094] The algorithm runs sufficiently fast that the first execution of step 514 after the timer has started will disclose that the time has not expired. This results in step 515 resetting BUS_Post_Trip_Lag_Flag. As long as Ignition_Signal remains false while BUS_PTI_Ignition_Off_Delay_Timer is timing the 0.5 second delay, step 513 will by-pass step 520 and proceed directly to step 514 . If Ignition_Signal has remained false for the 0.5 second delay, the next time that step 514 is performed, that step will be followed by step 521 that then sets BUS_Post_Trip_Lag_Flag. Should a momentary event cause Ignition_Signal to indicate true as BUS_PTI_Ignition_Off_Delay_Timer is timing, then step 517 will stop the timer from counting down to prevent it from expiring. The setting of BUS_Post_Trip_Lag_Flag is used as the indicator that ignition switch 47 is not in IGNITION position. One of the conditions of step 518 however is that BUS_Post_Trip_Lag_Flag be set, but not newly set, meaning not newly set during the current iteration. Hence at the first setting of BUS_Post_Trip_Lag_Flag, step 519 will not be performed after step 518 , and the algorithm will iterate beginning at start 500 . As long as Ignition_Signal has remained false, the next time that step 518 occurs, BUS_Post_Trip_Lag_Flag will still be set and not newly set. If BUS_LT_Red_PWL_Req and BUS_LT_Red_PWL_Req are also both false, step 519 will follow. Otherwise the algorithm will continue to iterate until they are.
[0095] BUS_Post_Trip_Lag_Flag serves to cause at least one additional iteration after the first determination that the ignition switch has actually been turned to OFF or ACCESSORY position. The purpose of the additional iteration is to assure that the latest pupil warning light request data, which is processed later in the loop, is taken into account.
[0096] When execution of the steps of FIG. 6 results in the system state being set to TRIGGERED state 106 , step 519 is followed by the next iteration of the algorithm beginning at start 500 , and assuming that step 501 continues to disclose park brake status as good, proceeding through steps 504 , 511 , and 512 after which a step 522 is performed. Step 522 will disclose that the system has been set to TRIGGERED state 106 , and that results in the algorithm proceeding to perform the sequence of steps shown in FIGS. 7A and 7B .
[0097] An initial step 523 resets BUS_Post_Trip_Lag_Flag to ensure an additional iteration. A following step 524 checks the status of BUS_Post_Trip_Timer_Flag and BUS_Post_Trip_Alarm_Timer. If either BUS_Post_Trip_Timer_Flag is not false or BUS_Post_Trip_Alarm_Timer has not expired, a step 525 is performed next. However, if both BUS_Post_Trip_Timer_Flag is false and BUS_Post_Trip_Alarm_Timer has expired, a step 524 A is performed before step 525 . Step 524 A starts BUS_Post_Trip_Alarm_Timer and sets BUS_Post_Trip_Timer_Flag.
[0098] Step 525 determines the status of both ignition switch 47 and the park brake switch. If both the ignition switch is in ACCESSORY position and the park brake is being applied, the algorithm determines the status of the disarming switch 45 S at the rear of the bus via a sequence of steps 526 , 527 , and 528 . If either the ignition switch is not in ACCESSORY position or the park brake is not being applied, the algorithm sets the value of BUS_Post_Trip_Button_Pushed_Flag to 0. After either step 528 or step 529 , the algorithm performs a step 530 .
[0099] The status of disarming switch 45 S is indicated by BUS_Post_Trip_Button_Pushed_Flag that can have any one of four unique values, 0, 1, 2, or 3.
[0100] BUS_Post_Trip_Button_Pushed_Flag is assigned the value 0 by the algorithm before the algorithm reaches step 525 . Step 526 checks the switch status to assure that BUS_Post_Trip_Button_Pushed_Flag has been reset to 0 and to assure that the disarming switch is not being actuated , i.e. is off, i.e. false. This corresponds to the rear door lever being in position barring the rear door from opening.
[0101] When step 526 confirms that BUS_Post_Trip_Button_Pushed_Flag has been set to 0 and that disarming switch 45 S is off, step 531 sets BUS_Post_Trip_Button_Pushed_Flag to the value 1.
[0102] So long as disarming switch 45 S remains non-actuated, i.e. off, during ensuing iterations of the algorithm, the value of BUS_Post_Trip_Button_Pushed_Flag remains 1 , and the algorithm will proceed through steps 527 and 528 without changing that value.
[0103] Whenever actuation of the disarming switch is first detected, step 527 will be followed by a step 532 before step 528 is performed. Step 532 advances the value of BUS_Post_Trip_Button Pushed Flag to 2, after which the algorithm proceeds to step 528 . If actuation of the disarming switch has ceased by the time step 528 executes, that step will cause a step 533 to be performed before step 530 . Step 533 advances the value of BUS_Post_Trip_Button_Pushed_Flag to 3.
[0104] The purpose of the sequence of requiring BUS_Post_Trip_Button_Pushed to advance through values 0 through 3 in succession is to provide the maximum assurance that the disarming switch has actually been actuated and returned to its pre-actuation condition. The sequence checks the detailed sequence of switch conditions that occur when the switch is initially non-actuated, then actuated, and returned to non-actuated.
[0105] Step 530 checks the status of the BUS_Post_Trip_Alarm_Timer, the Post_Trip_Timer Flag, and the BUS_Post_Trip_Button_Pushed_Flag.
[0106] If disarming switch 45 S has not been actuated and released within the time allotted by the alarm timer, the algorithm will proceed to a first entry point A in the sequence of steps shown in FIG. 7B . On the other hand, if the disarming switch has been actuated and returned to non-actuated condition within the time allotted by the alarm timer, the algorithm will proceed to a step 534 still in FIG. 7A that sets BUS_Post_Trip_Alarm_State to UNARMED and causes the cluster alarm 32 to give one short beep to announce UNARMED state 104 .
[0107] After step 534 , the algorithm proceeds to a second entry point B in FIG. 7B . That second entry point is at a step 535 that checks the status of ignition switch 47 and snooze switch 57 . The current iteration of the algorithm will stop unless the ignition switch is in ACCESSORY or IGNITION position and the snooze switch has been pressed, in which case a step 536 would be performed before the current iteration stops. With the driver presumably at the rear of the bus when the disarming switch is operated, he or she cannot be pressing the snooze switch, in which case step 536 does not occur and the system remains in UNARMED state 104 .
[0108] When the algorithm next iterates, steps 501 , 504 , and 511 will be performed after which step 508 resets BUS_Post_Trip_Lag_Flag and stops BUS_Post_Trip_Alarm_Timer and BUS_Post_Trip_Alert_Timer. Since the driver will not be giving the pupil warning, step 509 will no longer be able to arm the system although the driver can open the door to allow himself or herself to exit after having turned ignition switch 47 off and removed the key.
[0109] Should step 530 disclose that the BUS_Post_Trip_Button_Pushed_Flag value is not 3, then the algorithm proceeds to performs steps shown in FIG. 7B beginning with a step 537 that determines enablement of Bus_Post_Trip_Alert_Timer. If Bus_Post_Trip_Alert_Timer is not enabled, then a step 538 starts it and also sets BUS_Post_Trip_Alert_Flag.
[0110] When successive iterations of the algorithm ahead of step 537 reach step 537 for the first time, the steps immediately following step 537 will cause the low-level alarm to be given. That low level alarm will continue for one minute unless the disarming switch at the rear of the bus is operated in accordance with the sequence described earlier within that one minute time interval. After steps 537 and 538 , a step 539 determines if Bus_Post_Trip_Alert_Timer has expired, and if it is determined that it has not expired, a step 540 determines if BUS_Post_Trip_Timer_Flag is true. If that flag is not true, a step 543 sets EGC_Alarm_AlwaysBeep_Reg, causing cluster alarm 32 to continually sound as the algorithm continually iterates. A next step 544 determines the ignition switch status.
[0111] If ignition switch 47 is in OFF position, both Acccessory_Signal and Ignition_Signal will be false, and a step 546 will set Send_Flag_ 61207 before a step 545 is performed. If ignition switch 47 is in either ACCESSORY position or IGNITION position, then step 546 is omitted, and step 545 determines if BUS_Post_Trip_Alert_Flag is true. If BUS_Post_Trip_Alert_Flag is true, a step 547 issues Low_Beam_Override_Req=100 before step 535 is performed. If BUS_Post_Trip_Alert_Flag is false, step 547 is omitted. (The =100 qualifier following Low_Beam_Override_Req means that when the low beams are on, they are on at 100% intensity.)
[0112] The purpose of BUS_Post_Trip_Alert_Flag is to provide a toggle for timing the low beams of headlamps 28 , 30 and city horn 26 on and off. The toggle occurs by BUS_Post_Trip_Alert_Flag being repeatedly set for 0.5 second and then reset for 0.5 second. BUS_Post_Trip_Alert_Timer times the 0.5 second time intervals.
[0113] Should step 540 disclose that BUS_Post_Trip_Timer_Flag is true, a step 542 determines if BUS_Post_Trip_Alert_Flag is true. If BUS_Post_Trip_Alert_Flat is not true, the algorithm proceeds to step 535 . If it is true, a step 548 issues Elec_City_Horn_Req_Sem and Low_Beam_Override_Req=100. The _SEM qualifier following Elec_City_Horn_Req means that the horn request is conveyed via semaphore.
[0114] BUS_Post_Trip_Alert_Timer was first started by step 519 when the system state changed from ARMED state 104 to TRIGGERED state 106 . As long as that BUS_Post_Trip_Alert_Timer has not expired and BUS_Post_Trip_Button_Pushed_Flag does not have the value 3 , step 530 will be followed by step 537 . Collectively, steps 538 , 539 , 540 , 541 , and 542 will toggle the BUS_Post Trip_Alert Flag. The toggling is monitored by step 545 to turn the headlamp low beams on at 100% intensity for 0.5 second and then off for 0.5 second via step 547 . For the first minute of TRIGGERED state 106 step 543 will set EGC_Alarm_AlwaysBeep_Req by continually setting EGC_Alarm_AlwaysBeep_Req at each iteration of the algorithm. Cluster alarm 32 will therefore continually sound until either the request is discontinued or cluster 22 is placed in a sleep mode that discontinues operation of devices in the cluster like cluster alarm 32 .
[0115] Because certain conditions may place the cluster in sleep mode before the inventive algorithm has concluded, setting Send_Flag_ 61207 serves to override the effect of those conditions and keep the cluster awake until the algorithm concludes.
[0116] Consequently during the first minute of TRIGGERED state 106 , cluster alarm 32 will continually sound and the headlamp low beams will flash. That is the low_level warning.
[0117] After the first minute has elapsed without the system being disarmed, the high-level warning is given. The first time that step 524 is performed after the first minute in TRIGGERED state 106 has elapsed, it will determine that BUS_Post_Trip_Alarm_Timer has expired. Since BUS_Post_Trip_Timer_Flat is also false, step 524 will be followed by step 524 A that restarts BUS_Post_Trip_Alarm_Timer and sets BUS_Post_Trip_Timer_Flag to true.
[0118] With BUS_Post_Trip_Timer_Flag now true, step 540 will be followed by step 542 . With steps 537 , 538 , 539 , and 541 still toggling BUS_Post_Trip_Alert_flag, step 542 in conjunction with step 548 will now not only continue to flash the headlamp low beams, but also to turn horn 26 on and off with the flashing of the headlamps. Since step 543 is no longer setting EGC_Alarm_AlwaysBeep_Req at each iteration of the algorithm, cluster alarm 32 does not sound during high-level alert.
[0119] If the system has not been disarmed within the additional ten minutes during which the high-level alert is being given, the first time that step 530 is performed after the expiration of the additional ten minutes, it will return the system to UNARMED state 102 , discontinuing the alert in order to conserve battery power.
[0120] With the system in TRIGGERED state 106 , actuation of snooze switch 57 places the system in SNOOZE state 108 , setting BUS_Post_Trip_Alarm_State to SNOOZE. The purpose of SNOOZE state 108 is to allow the driver to interrupt TRIGGERED state 106 for a limited amount of time. When the algorithm reaches step 535 for the first time after snooze switch 57 has been actuated, i.e. set to true, the immediately following step 536 sets EGC_Alarm_ 1 ShortBeep_Req to true, causing cluster alarm 32 to sound briefly to announce SNOOZE state 108 . A BUS_PTI_Snooze_Minute_Counter is set to BUS_PTI_Snooze_Minutes_Param. BUS_PTI_Snooze_Timer is also started. BUS_PTI_Snooze_Timer counts sixty second, i.e. one minute, time intervals.
[0121] At the next iteration of the algorithm, steps 501 , 504 , 511 , and 522 will be performed. With step 522 now disclosing that the system is no longer in TRIGGERED state 106 , a step 550 is next executed resulting in the sequence of steps shown in FIGS. 8A and 8B . A first step 551 in FIG. 8A stops, but does not reset, BUS_Post_Trip_Alarm_Timer and BUS_Post Trip_Alert_Timer. A following step 552 determines the status of ignition switch 47 .
[0122] If ignition switch 47 in step 552 is in a position other than ACCESSORY position, then a step 553 sets BUS_Post Trip_Button Pushed_Flag to 0. If the ignition switch is in ACCESSORY position and the park brake is being applied, then the status of disarming switch 45 S is determined by steps 554 , 555 , 556 which will be recognized as a sequence identical to sequence 526 , 527 , 528 in FIG. 7A . Depending on the determination of each step 554 , 555 , 556 , the value of BUS_Post_Trip_Button_Pushed_Flag may be advanced. Hence, the status of the disarming switch will have been determined at the time that a step 560 occurs.
[0123] Step 560 determines whether the disarming switch has been depressed and released. If it has, then a step 561 sets BUS_Post_Trip_Alarm_State to UNARMED, sets EGC_Alarm_ 1 ShortBeep_Req to true, causing cluster alarm 32 to sound briefly to announce UNARMED state 102 , and stops BUS_PTI_Snooze_Timer. This allows the disarming switch to return the system to UNARMED state 102 from SNOOZE state 108 . Thereupon the algorithm performs a step 562 . When step 560 determines that the disarming switch has not been depressed and released, step 561 is omitted and 562 is performed immediately after step 560 .
[0124] Step 562 determines if the BUS_PTI_Snooze_Timer has expired and if the BUS_PTI_Snooze_Minutes_Counter is greater than zero. Although some positive number of minutes (determined by BUS_PTI_Snooze_Minutes_Param) is set in BUS_PTI_Snooze_Minutes_Counter at the first performance of step 536 ( FIG. 7B ), the first performance of step 562 will indicate that snooze time has not yet expired because the first sixty seconds of snooze time are just starting, and therefore the algorithm will execute steps in FIG. 8B .
[0125] When step 562 determines that BUS_PTI_Snooze_Timer has expired and that the BUS_PTI_Snooze_Minutes_Counter is greater than zero, then steps 563 and 564 are performed before steps in FIG. 8B are executed. Step 563 decrements BUS_PTI_Snooze_Minutes_Counter by one, thereby subtracting one minute from the number of minutes remaining. Step 564 determines if BUS_PTI_Snooze_Minutes_Counter is greater than zero. If it is, then a step 565 starts BUS_PTI_Snooze_Timer to count down another 60 seconds. If it is not, then step 565 is omitted.
[0126] A first step 566 in FIG. 8B determines if the bus is moving at a speed greater than some minimum, 3 kilometers per hour in this embodiment, and less than some maximum. Step 566 also determines if the source of the speed data is good. If that status is good and speed is in the range between the minimum and maximum, then a step 567 sets BUS_PTI_Snooze_Minutes_Counter to BUS_PTI_Snooze_Minutes_Param and also starts BUS_PTI_Snooze_Timer. Then a step 568 is performed.
[0127] When step 567 determines either that status is not good or speed is not within the range, then step 568 is performed immediately after step 566 with step 567 being omitted.
[0128] Step 568 determines the status of ignition switch 47 . If either Ignition_Signal or Accessory_Signal is newly off, then a step 569 starts BUS_PTI_Ignition_Off_Delay_Timer with the same 0.5 second BUS_PTI_Ignition_Off_Delay_Const. If that is not the case, then step 569 is omitted.
[0129] A step 570 determines if BUS_PTI_lgnition_Off_Delay_Timer has expired, meaning having timed out. As long as that timer has not expired, BUS_Post_Trip_Lag_Flag is reset (step 57 1 ). A step 573 then determines if the Ignition_Signal or Accessory_Signal is “back on”, meaning simply is the switch in IGNITION position or ACCESORY position. When step 570 determines that BUS_PTI_Ignition_Off_Delay_Timer has expired, a step 572 sets BUS_Post_Trip_Lag_Flag before step 573 is performed.
[0130] When step 573 determines that the Ignition_Signal or Accessory_Signal is “back on”, a step 574 stops BUS_PTI_Ignition_Off_Delay_Timer before a step 575 is performed. If that is not the case, then step 575 is performed immediately after step 573 with step 574 being omitted.
[0131] By comparison of the sequence of steps 568 , 569 , 570 , 571 , 572 , 573 , and 574 with the sequence steps 513 , 520 , 514 , 515 , 521 , 516 , and 517 , the description of the former sequence given earlier leads one to understand that the purpose of the latter sequence is to assure that the ignition switch is actually in either ACCESSORY position or IGNITION position.
[0132] Step 575 determines either if BUS_PTI_Snooze_Timer has expired, the count of BUS_PTI_Snooze_Minutes_Counter is zero, and bus speed is below the minimum 3 kilometers per hour or if ignition switch 47 is in OFF position and there is no pupil warning input 50 . If either is true, then a step 576 returns the system to TRIGGERED state 106 , starts BUS_Post_Trip_Alarm_Timer, resets BUS_Post_Trip_Timer_Flag, resets BUS_Post Trip_Button Pushed_Flag and stops BUS_PTI_Snooze_Timer.
[0133] If both are not true, the algorithm stops to await the next iteration.
[0134] The ability to place the alert system in SNOOZE state 108 by turning ignition switch 47 to either ACCESSORY or IGNITION position and then pressing snooze switch 57 provides a certain maximum amount of time, 20 minutes for example as set by BUS_PTL_Snooze_Minutes_Param, for the driver to temporarily switch the system out of the TRIGGERED state before either the system is disarmed or the alert is resumed. SNOOZE state 108 temporarily discontinues the alert that is being given, either high-level or low-level.
[0135] There may be situations during a trip where the alert should not be given because the driver shuts off motor 14 temporarily before the trip is completed. (Keep in mind that shutting off the motor with the system in ARMED state 104 changes the system state to TRIGGERED state 106 setting off the alert.) If conditions that caused the system state to change to SNOOZE state 108 remain unchanged for the allotted snooze time, i.e. 20 minutes, the system automatically reverts to TRIGGERED state 106 to prevent the system from being defeated. In the usual course of a trip before all pupils are either picked up or dropped off, motor 14 will be typically be restarted and the bus will again be driven within the allotted snooze time. Operation of the bus at or above 3 km/hr continually resets the BUS_PTI_Snooze_Minutes_Counter to 20 minutes and keeps the system in SNOOZE state 108 . The system state will change from SNOOZE state 108 to TRIGGERED state 106 when ignition switch 47 is again turned off at the end of the trip.
[0136] Whenever the algorithm proceeds through steps 501 , 504 , 511 , 512 , and 522 to step 550 , and step 550 discloses that BUS_Post Trip_State is not in SNOOZE state 108 , a step 580 that is identical to step 502 occurs placing the system in DISABLED state 100 .
[0137] While a presently preferred embodiment of the invention has been illustrated and described, it should be appreciated that principles of the invention are applicable to all embodiments that fall within the scope of the following claims.
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A system and method for alerting responsible personnel to perform a post-trip inspection check for passengers remaining on a bus at the end of a trip by issuing audible and/or visual alerts when the bus is parked and the motor shut off at the end of the trip. The ignition switch ( 47 ) must be placed in ACCESSORY position and a park brake applied for the system to be rendered capable of being disarmed by operation of a disarming device ( 45 S) at the rear of the bus. Operation of the disarming device is indicated by a correct sequence of operating conditions of the device, namely first non-actuated, then actuated, and then non-actuated. The system includes a SNOOZE state that allows the ignition switch to be temporarily turned off during a trip and the alert to be stopped by pressing a snooze switch.
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BACKGROUND OF THE INVENTION
The present invention relates to beds having side rails. More particularly, the invention relates to an apparatus for bed side rails which prevents injuries to bed occupants by preventing them from placing their extremities between components of the bed rail.
Hospital type beds usually have provisions for vertically movable side rails. Such side rails provide for patient control while facilitating activities such as removing and replacing bed sheets and mattresses and moving patients. When the side rails are raised and set in their normal working position, the lowermost side rails of even the best beds are in a horizontal position at or just above the upper plane of the mattress.
It is well known that bed occupants or patients who are asleep, or who cannot control or do not realize the significance of their movements, often injure themselves when their appendages become lodged between components of the bed side rails, or more commonly between a bed side rail and mattress or mattress support. Various designs have been advanced to remove this source of patient injury.
U.S. Pat. No. 4,370,765 describes an envelope for a bed having side rails. The envelop comprises an envelope portion for enveloping a side rail running the length of the bed and a flap positionable between and attachable to a mattress and mattress support. The envelope portions are made of durable and washable meshed, netted or screen-like plastic or polymeric material such as nylon. The flap is made of washable cotton sheet or canvas material.
Another approach, represented by U.S. Pat. No. 4,827,545, employs a protective covering assembly comprised of pipe insulation cut and fitted around the side rail members and a protective cover portion for enveloping a side rail running the length of the bed. The protective cover is made of a plastic upholstery.
The patents mentioned above, as well as others disclose a variety of techniques and structures for preventing patient bed injuries. However, such techniques and structures are not suitable for many hospital type beds.
Modern hospital type beds generally allow adjustment of the mattress over a range of segmental elevational configurations. Movement of the mattress changes its position relative to the bed side rails. Additionally, the bed rails on many modern hospital type beds typically employ a number of independently positionable bed rail segments which are arrayed down each side of the bed. Movement of the mattress support changes the position of the bed rail segments relative to each other.
SUMMARY OF THE INVENTION
The present invention overcomes the above briefly discussed and other deficiencies of the prior art by providing a novel bed rail apparatus which is sufficiently flexible to accommodate variable relative positions between the bed rail and the mattress and between bed rail segments. A bed rail apparatus in accordance with the present invention is characterized by ease of application and removal from the bed.
A bed rail apparatus in accordance with the invention is an envelope .like assembly comprised of spaced opposed substantially rectangular side panels attached along their top and side edges to opposing side edges of a border strip. The side panels and border strip are made from elastomeric material, for example, control mesh or power net. An additional border strip may be attached along each side panel bottom edge to provide additional strength.
The envelope assembly is open along the bottom edge such that it may be slipped over a bed rail. The elastomeric material may be stretched to envelop padding material disposed around the bed rail. A foot flap composed of elastomeric material is provided for attaching the cover to the mattress support. For single rail bed embodiments, the flap is attached to the top edge of the rail cover. For multiple rail bed embodiments, the bottom edges of the side panels are joined by the foot flap where the side rail gaps occur. The flap carries grommets which are typically attached to the mattress support by carabiner clips or similar means.
An object of the invention is to provide a new and improved bed rail apparatus for use on beds having side rails.
Another object of the invention is to provide a new and improved bed rail apparatus that is sufficiently flexible to accommodate variable relative positions between the bed rail and the mattress or between bed rail segments.
A further object of the invention is to provide a new and improved bed rail apparatus that is sufficiently flexible to accommodate the additional bulk of padding material disposed around bed rail segments.
A yet further object of the invention is to provide a new and improved bed rail apparatus that is easily installed and removed from the bed.
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 wherein like reference numerals refer to like elements in the several figures and in which:
FIG. 1 is a perspective view of a hospital bed having two side rail segments on each side and having one rail apparatus in accordance with the invention fully installed and one rail apparatus partially installed;
FIG. 2 is a side view, suspended for illustration purposes, of a bed rail apparatus, for a bed having two side rail segments on each side, in accordance with the present invention;
FIG. 3 is a bottom view of the bed rail apparatus of FIG. 2;
FIG. 4 is a perspective view of a bed rail apparatus, for a bed having one side rail per side, in accordance with the present invention;
FIGS. 5A, 5B and 5C are side views of three alternative mattress configurations for a hospital bed having a bed rail apparatus in accordance with the present invention; and
FIG. 6 is a perspective view of a hospital bed with the mattress removed and having bed rail apparatus in accordance with the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
With reference to the drawings wherein like numerals represent like parts throughout the figures, a bed rail apparatus in accordance with the present invention is generally designated with the numeral 10. The bed rail apparatus 10 is particularly adapted for a hospital bed 11 of a type having a mattress 32, a mattress support 34, bed support means (not shown) and at least one bed rail 30 on each side. The bed rail 30 typically consists of a plurality of elongate, intersecting tubular members that are adapted to move up and down relative to the bed. Each bed rail 30 may be composed of a plurality of bed rail segments 30', 30". The hospital bed has means (not shown) for adjusting the mattress 32 over a range of segmental elevational configurations. The mattress 32 is typically relatively stiff and does not conform exactly to the configuration assumed by the mattress support 34 resulting in relative movement between the mattress 32 and the bed rail 30. Additionally, movement of the mattress support 34 changes the position of the bed rail segments 30', 30" relative to each other.
The rail apparatus 10 comprises a folded resilient sheet 12 joined along the lateral end edges to define an envelope having an open bottom. The rail apparatus 10 is pulled over the bed rail 30 and secured in place by means that are described below. The resilient sheet 12 is composed of a fire retardant elastomeric material containing Lycra™ material or similar elastic fiber. The resilient sheet 12 may be divided into a pair of opposed side panels 13, 13' which are joined at their top portions 18, 18' and their end portions 15, 15'.
In the embodiment shown in FIGS. 3 and 4, the first and second side panels 13, 13' are joined by a border strip 14. The border strip 14 is composed of a heavier grade elastomeric material, for example elastic webbing and comprises longitudinally extending first and second side edge portions 42, 44. The first edge portion 42 of the first border strip 14 is attached to the top portion 18 and the first and second end portions 15 of the first side panel 13 and the second edge portion 44 of the first border strip 14 is attached to the top portion 18' and the first and second end portions 15' of the second side panel 13', the border strip 14 thereby defines top and end portions 46, 48.
A foot flap 16 functions as a barrier to prevent the bed occupant from sticking an arm or leg through the space between the mattress 32 and the bed rail 30. In an embodiment for beds having single side rails on each side, a first edge portion 23 of the foot flap 16' is attached to one of the side panel top edges 18, as shown in FIG. 4. Grommets 22 are mounted adjacent the second edge portion 23" of the foot flap 16'. Carabiner clips 24 or similar means, engage through the grommets 22 to the mattress support 34.
In an embodiment for beds having multiple side rails 30, 30' on each side of the bed, the foot flap 16 is connected to the bottom edges 20 of the first side panel 13 and the bottom edge 20' of the second side panel 13' where the side rail gap occurs, as shown in FIGS. 1, 2 and 3. Grommets 22 are mounted adjacent the foot flap border portion 25. Carabiner clips 24 or similar means, engage through the grommets 22 to the mattress support 34.
In an alternative embodiment, the foot flap 16 of one bed rail apparatus 10 may be connected to the foot flap 16 of another bed rail apparatus 10 by a sheet of resilient material 40, as shown in FIG. 6. The sheet is disposed between the mattress 32 and mattress support 34.
Bottom border strips 28, 26' may be attached along each side panel bottom edge portion 21, 21'. Handles 28 may be attached at the end portions 48 of the border strip 14, as shown in FIG. 4. Alternatively, the handles 28, 28' may be attached to the first end section 50 of the first border strip 26 to the first end section 54 of the second border strip 26' and from the second end section 52 of the first border strip 26 to the second end section 56 of the second border strip 26', as shown in FIGS. 2 and 3. Single handles 28 may also be used. The handles 28 facilitate installation and removal of the bed rail apparatus 10 by providing a means for gripping and stretching the apparatus.
The bed rail apparatus 10 is open along the bottom edge 20, 20' such that a bed rail apparatus 10 may be slipped over the bed rail 30, as shown in FIG. 1. A foot flap 16 is attached to The mattress support to prevent patients from inadvertently sticking an appendage through the gap between the bed rail 30 and the mattress 32. Use of elastomeric material allows the apparatus 10 to stretch and accommodate relative movement between the mattress 32 and the rail 30 and between the bed rail segments 30', 30" when the mattress position is adjusted. Additionally, the use of elastomeric material allows the apparatus 10 to stretch and envelop padding material disposed around bed rail components and pillows or other padding material disposed between bed rail components. Triple interlocking stitches are utilized to join border strips 14, 26, 26' to the side panels 13, 13'. These stitches provide strength while allowing stretching of the joined border strips 14, 26, 26' and side panels 13, 13'.
FIGS. 5A, 5B and 5C illustrate how the bed rail apparatus 10 accommodates various mattress 32 configurations. In FIG. 5A, the whole mattress 32 is in a "normal" horizontal position. The bed rail apparatus 10 may be stretched slightly to provide a snug fit and taut appearance. In FIG. 5B, an upper portion of the mattress 36 has been raised to an inclined position relative to a lower portion of the mattress 38. As shown, the bed rail apparatus 10 stretches along the bottom edge 20 to accommodate the motion of bottom of bed rail segment 30+ away from the bottom of bed rail segment 30". In FIG. 5C, bed rail segment 30' has been raised to a higher position than bed rail segment 30". The bed rail apparatus 10 stretches along its length to accommodate the relative motion between the two bed rail segments 30' and 30". The same degree of patient protection is provided for every mattress position.
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that the present invention has been described by way of illustration and not limitation.
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A bed rail cover for removable placement over a bed side rail comprises two spaced, opposed side panels joined along their side and top edges to a border strip, the panels and border strip being composed of an elastomeric material. A flap of elastomeric material attaches the cover to the bed, preventing bed occupants from placing their appendages through the gap between the mattress and the rail. Use of elastomeric material allows the cover to accommodate changes in the relative positions of the mattress and rails and between rail segments when the mattress position is adjusted.
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BACKGROUND
The invention relates generally to catheters, and more particularly, to steerable catheters for performing electrophysiological procedures, such as mapping electrical signals emitted from conductive cardiac tissue and ablating aberrant cardiac tissue at the point of arrhythmia origination in order to terminate the arrhythmia.
The heart beat in a healthy human is controlled by the sinoatrial node (S-A node) located in the wall of the right atrium. The S-A node generates action potentials which are transmitted through pathways of conductive heart tissue in the atrium to the atrioventricular node (A-V node) which in turn transmits the signals throughout the ventricle by means of the His and Purkinje conductive tissues. Improper growth of or damage to the conductive tissue in the heart can interfere with the passage of electrical signals from the S-A and A-V nodes resulting in disturbances to the normal rhythm of the heart, referred to as cardiac arrhythmia.
If the arrhythmia is refractory to medication, an alternative treatment is to ablate the aberrant conductive tissue. However, that aberrant tissue must first be located. One technique involves the electrical mapping of signals emanating from conductive cardiac tissue to locate the aberrant tissue causing the arrhythmia. Ablation may then be performed. Ablation of the aberrant conductive tissue usually controls the arrhythmia and allows the heart rhythm to return to an acceptable level.
One conventional method for mapping the electrical signals from conductive heart tissue is to provide an array of electrodes on the distal extremity of a catheter and place those electrodes in contact with the interior of a patient's heart. Typically, the catheter is introduced into the cardiovascular system of the patient through a blood vessel and advanced to an endocardial site such as the atrium or ventricle of the heart. When placed into the blood vessel, the catheter must follow the irregularly shaped path defined by the blood vessel and branch vessels until the distal end of the catheter reaches the desired location. To assist in steering the catheter, some catheters have a curved distal tip. While this pre-formed curve may fit the curves of some blood vessels, it rarely fits all anatomical possibilities. Greater freedom of movement is desirable.
To achieve greater control over the movement of the catheter in steering it through the cardiovascular system to the desired location in the patient, prior catheters have used guide wires to selectively vary the shape of the distal tip of the catheter. In another technique, a control line is attached at a point adjacent the distal tip of the catheter. Pulling the proximal end of the control line causes the distal tip of the catheter to bend in one direction. Other designs have used multiple control lines to obtain bending in multiple directions; however, the size of the catheter increases. Larger catheters are undesirable due to the difficulties involved in moving them through the patient's cardiovascular system and the increased blockage to blood flow. While the control line approach provides increased freedom of control over the movement of the distal end of the catheter, its effect in prior techniques is limited to an arc with a fixed radius.
In another technique, a mandrel or guide wire is also located in the catheter in addition to the control line and is moved to alter the radius of bend of the distal end of the catheter. The mandrel would be moved more towards the distal end or more towards the proximal end of the catheter to alter the radius of bend of the distal end. While such an approach has been found to yield improved control over the movement of the distal end, the disclosed technique required that the physician use two hands to exert this control. Additionally, no means were provided for holding the mandrel and control line in position once the desired bend was obtained thereby resulting in the physician having to hold both the mandrel end and the operating mechanism of the control line. Requiring the use of two hands for the steering function alone restricts the physician from performing other tasks at the same time.
Another consideration in keeping the catheter small in size but providing an increased steering capability is the torsional rigidity of the catheter. In catheters with low torsional rigidity, torsion may accumulate as the proximal end of the catheter is twisted by the physician. Then as the distal end finally begins rotating, the accumulated torsional moment will tend to unwind the catheter, resulting in rapid rotation of the tip inside the blood vessel. Such unwinding may result in the distal tip of the catheter overshooting the branch vessel entrance then requiring further steering manipulation on the part of the physician lengthening the procedure. Thus it is desirable to have increased torsional rigidity of the catheter so that rotating the proximal end of the catheter will result in immediate rotation at the distal end; i.e., immediate torque reaction.
A further consideration in navigating the catheter into the desired position in the patient is the bending rigidity or stiffness of the catheter. In some cases, increased force is required to advance the distal end of the catheter through a certain vessel position or to hold it against a particular site such as buttressing the catheter against a wall of the aorta or against a valve lip. However, decreased bending rigidity is beneficial in some cases. Therefore it would be desirable to provide variable bending rigidity of the catheter to provide increased steering and positioning control. Such a feature would be desirable in an electrophysiological procedure catheter due to the requirement for navigation completely into the heart and for continued contact with particular tissue during the beating action of the heart. Additionally, it would be desirable to incorporate the control means over the bending rigidity of the catheter into the same control device as is used for the other steering mechanisms.
Frequently, the position of the distal portion of the catheter within the heart may have to be adjusted one or more times in order to provide a complete and comprehensive view of the signals from the electrically conductive heart tissue which is necessary to detect the point where the arrhythmia originates. Once the origination point for the arrhythmia is determined, the conductive heart tissue at the site can be ablated. RF heating is one technique typically used for ablation. Successful ablation of the conductive tissue at the arrhythmia initiation site usually terminates the arrhythmia or at least moderates the heart rhythm to acceptable levels. Increased and easier control over the steering and positioning of the catheter would facilitate the mapping and ablation of the heart tissue.
Hence, those skilled in the art have recognized the need for a catheter for use in electrophysiological procedures which provides increased control over steering and positioning the catheter while not increasing the size of the catheter. It has also been recognized as desirable a catheter with increased torsional rigidity and a means for providing increased control over the axial rigidity of the catheter. The present invention fulfills these needs and others.
SUMMARY
Briefly and in general terms, the present invention is directed to a catheter which is adapted to perform electrophysiological procedures, such as detecting arrhythmia and ablating conductive pathways within a patient's myocardium in order to control arrhythmia. The catheter comprises a body member; a manipulation handle attached to the proximal end of the body member for applying torque to the body member, the catheter body being attached to the handle such that when the handle is rotated about its longitudinal axis, the body member rotates about its longitudinal axis in response. The handle also has a control device adapted for control movements in a first plane and in a second plane simultaneously.
A deflection control line is slidable in a direction parallel to the longitudinal axis of the body member and has its distal end attached to the distal portion of the catheter and its proximal end attached to the control device of the handle so that tension applied to the control line by movement of the control device in the first plane will cause the deflection of the distal portion of the catheter.
A stiffening member is disposed within the body member of the catheter and is slidable in a direction parallel to the longitudinal axis of the body member, said stiffening member providing increased rigidity to the portion of the body member in which the stiffening member is located. Additionally, the stiffening member is connected at its proximal end to the control device of the handle such that movement of the control device in the second plane controls the position of the stiffening member in the body member. In a further aspect, a stiffening member in accordance with one embodiment includes a tapered distal end section with a ball formed on the distal tip, the tapered section terminating at the ball. The tapered section permits easier bending of this portion of the stiffening member so that as it is advanced into the body member, it may negotiate a bend in a catheter which is already in position. The ball protects the body member of the catheter from being pierced by the stiffening member as the stiffening member is advanced and contacts a bend in the body member.
The deflection control line may be a wire or cable which is slidably disposed in the body member of the catheter. An open channel may be formed entirely within an inner tubular member of the body member, or may be formed in the exterior of the tubular member, and extends to the flexible distal portion of the catheter shaft where the distal end of the control line is attached. Tension applied to the control line by the physician operating the control device causes the flexible distal portion of the catheter shaft to be deflected from the central longitudinal axis of the catheter shaft and thereby allows the physician to control the shape of the distal extremity during the procedure which in turn facilitates steering through blood vessels and placement of the distal extremity against the cardiac tissue within the patient's heart. The anchoring element may be a plate fixed within a transverse plane in the distal portion of the catheter shaft or a cylindrical member disposed about the inner tubular member.
In accordance with another aspect, a torsion device for increasing the torsional rigidity of the catheter body is coupled with the body member of the catheter so that torque applied to the proximal end of the body member will be rapidly reflected at the distal end. In a further aspect, this torsional device comprises a layer of aramid fibers mixed with an epoxy, the layer being located within the body member such that rotating the handle results in rapid rotational response at the distal end of the catheter. Movement of the handle in a rotational sense controls the rotational position of the distal end of the catheter and movement of the handle in a longitudinal sense control the longitudinal position of the distal end of the catheter.
The handle control device may comprise a rotatable slide element, the rotation of which advances or retracts the stiffening element and the sliding action of which applies or releases tension on the control line. In another feature, the range of movement of the rotatable sliding element and the coupling of the control line thereto are selected to result in a complete release of tension on the control line when the rotatable sliding element is at one end of the range of sliding movement thereby permitting the body member to resume its substantially straight form. The range of movement caused by rotation of the rotatable slide element is also selected to permit positioning the stiffening member at a first position resulting in a first radius of curvature of the distal end of the body member when tension is applied to the control line, and at the other end of the range, in positioning the stiffening member at a second position resulting in a second radius of curvature of the distal end of the body member when tension is applied to the control line. The second radius of curvature is different from the first radius. At positions in between the respective ends of the ranges, various bends are possible and the bending of the distal end of the catheter is continuously variable between the ends of the ranges. In a further aspect, the positioning of the stiffening rod controls the bending stiffness of the body member and the range of movement of the control device is selected to achieve a predetermined range of bending rigidity.
In yet another feature in accordance with the principles of the invention, the handle and rotatable sliding element are symmetrically shaped to facilitate complete single-handed operation of the handle by the physician including rotation of the handle, longitudinal movement of the handle, rotation of the rotatable sliding element, and sliding of the rotatable sliding element. The handle itself may be rotated about its longitudinal axis while the sliding element is being both rotated and slid. Additionally, the handle is shaped for ease in grasping and retention by the physician's hand and further, the rotatable sliding element is shaped so that it may be both rotated and slid by the digits of that same hand. The sliding element in one aspect, has a groove formed about the outside and the two surfaces on either side of the groove are conveniently used by the operator to control sliding movement of the element.
The handle may also contain indicia, such as a colored band positioned on the handle body, to indicate movement of the rotatable slide element beyond a preselected point. The handle may also include gradations to provide a visual reference system to indicate the present position of the rotatable sIiding element in its range of movement.
The catheter may have one or more electrodes on a distal portion, and may have an ablation electrode provided on the distal tip for ablation of cardiac conductive pathways. One or more electrical conductors extend within the body member and are electrically connected to the electrodes on the distal portion of the catheter. Additional electrical conductors extend within the body member to electrically connect the ablation electrode to an electrical source, preferably a high frequency electrical source, for providing the ablation energy.
The catheter of the invention allows a physician to effectively control the shape and stiffness of the catheter during electrophysiological procedures, including the detection and ablation of aberrant conductive cardiac tissue. The catheter of the present invention can be more easily manipulated within a patient's heart and allows the physician to more accurately place the catheter electrodes as desired. Other aspects and advantages of the invention will become apparent from the following detailed description and accompanying drawings, illustrating by way of example the features of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an elevation view of an electrophysiological catheter embodying features of the invention;
FIG. 2 is an enlarged longitudinal cross-sectional view of the distal portion of the catheter along lines 2--2 shown in FIG. 1;
FIG. 3 is a transverse cross-sectional view of the distal portion of the catheter shown in FIG. 2, taken along the lines 3--3;
FIG. 4 is a schematic elevation view of a distal portion of the catheter shown in FIG. 1 with tension applied to a control line which extends into the distal portion of the catheter;
FIG. 5 is a schematic elevation view of a distal portion of the catheter similar to that shown in FIG. 4 except that a stiffening rod is advanced into the distal portion of the catheter shaft in addition to tension being applied to the control line;
FIG. 6 is a schematic elevation view of a distal portion of the catheter similar to that shown in FIG. 5 except that the stiffening rod is advanced farther into the distal portion of the catheter than that shown in FIG. 5;
FIG. 7 is a transverse cross-sectional view of an alternative embodiment incorporating principles of the invention;
FIG. 8 is an enlarged longitudinal view, partially in section, of a manipulating handle secured to the proximal end of the catheter as shown in FIG. 1;
FIG. 9 is an exploded perspective view of the manipulating handle shown in FIG. 8;
FIG. 10 is a perspective view of the distal portion of the catheter shown in FIG. 1 with the jacket and a distal extremity cut away to illustrate the connection of the deflection control line to the anchor plate;
FIG. 11 is a perspective view of the distal portion of an alternative catheter with the jacket and a distal extremity cut away to illustrate the connection of the deflection line to an anchor cylinder;
FIG. 12 is a perspective view of the catheter shown in FIG. 1; and
FIG. 13 is a view of the distal end of a tapered stiffening member having a ball formed on the distal tip.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring now to the drawings with more particularity, wherein like reference numerals designate like or corresponding elements among the several views, there is shown in FIGS. 1-3, a catheter 10 usable for electrophysiological procedures and embodying features of the invention, including an elongated shaft or body member 11, a plurality of sensing electrodes 12 on the exterior of the body member along the distal portion 13 thereof and an ablation electrode 14 at the distal tip of the body member 11. The tip electrode functions both as an ablation electrode and as a sensing electrode; thus, both numerals 12 and 14 are pointing to it. The body member 11 has an inner lumen 15 which extends to the distal tip and which has disposed therein an electrical conductor 16 having a distal end electrically connected to the ablation electrode 14. Also extending within the inner lumen 15 are a plurality of electrical conductors 17 which have distal ends electrically connected to the sensing electrodes 12. Although three sensing electrodes 12 and one ablation electrode 14 are shown, this is for purposes of illustration only and is not meant to be restrictive of the invention. More or fewer of each of these electrodes may be used depending on the application. Additionally, the types of devices mentioned for sensing and ablation are for also only for purposes of illustration. For example, rather than using an "electrode" for ablation, a different type of energy transducer may be incorporated into the catheter.
The catheter body member 11 has a deflection control system 18 which has a distal end located at the distal portion 13 of the body member 11. The deflection control system 18 preferably comprises a control line or deflection wire 23 and a lubricous coating or jacket 24, e.g. a suitable fluoropolymer such as poly(tetrafluoro)ethylene which is available under the trademark Teflon® from E. I. dupont, deNemours & Company. Other fluoropolymers and other lubricous materials may be utilized to coat the deflection wire 23. The jacket 24 may be a lubricous sheath which allows for the movement of the deflection wire 23 therein. The deflection wire 23 is fixed to an anchor member 19 in the distal portion 13 so that, when tension is applied to the deflection wire 23 by means of the manipulating knob 43 mounted on the handle 20 at the proximal end of the catheter body member 11, the flexible distal portion 13 of the body member 11 will be deflected from its at rest position as shown in FIGS. 1 and 2 to the curved shape shown in FIG. 4. Preferably, the deflection control system 18 is disposed within a lumen 21 formed in the catheter body member 11 so as to be off-set from the central longitudinal axis 22 of the catheter body member 11 to more easily effect the deflection of the flexible distal portion 13. In the preferred embodiment shown in the figures, the body member 11 is constructed so that it is substantially straight when at rest and returns to that position when bending forces have been removed. The deflection control system 18 is used to impart such bending forces. FIGS. 1 and 2 illustrate a presently preferred embodiment of the invention wherein the catheter body member 11 has an inner tubular member 25 with the inner lumen 15 extending therein, an outer jacket or coating 26 on the exterior of the body member and a reinforcing tubular structure or layer 27 disposed between the outer jacket or coating 26 and the inner tubular member 25. The layer 27 is formed of multi-filament strands 28 within a polymeric matrix 29. Preferably, the reinforcing multi-filament strands 28 are braided as shown schematically in FIGS. 3 and 7. It has been found that this construction provides improved torsion rigidity along the entire length of the body member 11 proximal to the relatively short, flexible distal portion 13. Thus, the torque developed by rotating the manipulation handle 20 at the proximal end of the body member 11 will be quickly communicated to the distal end and the torsion storage problems experienced in the prior art are lessened. The tubular reinforcing structure 27 terminates at a location proximal to the distal tip of the body member 11 to provide the deflectable distal portion 13 with more flexibility.
A mandrel or stiffening member 31 is slidably disposed within a sheath 30, preferably formed of a fluoropolymer such as Teflon, both of which are disposed in the inner lumen 15 of the inner tubular member 25. The stiffening member is preferably formed of stainless steel, although other materials may function as well. The advancement of the stiffening member 31 within the distal portion 13 of the catheter body member 11 controls the stiffness of the distal portion and in conjunction with the deflection wire 23 controls the shape of the flexible distal portion as shown in FIGS. 4-6.
In FIG. 4 the stiffening member 31 is shown completely withdrawn from the distal portion 13 of the catheter body member 11 so that tension applied to the deflection wire 23 will result in the curvature of the distal portion 13 as shown. In the case shown in FIG. 5, the stiffening member 31 has a tapered end thus making that section more "bendable" and has been advanced into the distal portion 13. The tapered part of the stiffening member 31 has been bent and the curvature of the distal portion 13 is altered. Two radii of curvature are shown thus resulting in increased steering capability.
As depicted in FIG. 6, the stiffening member 31 is more stiff and has been advanced even farther into the distal portion 13 of the body member 11. The curvature is altered again. The portion 32 of the body member which extends distal to the location of the anchor member remains essentially straight.
FIG. 13 presents an enlarged view of the stiffening member 31 of FIG. 5. In accordance with this embodiment, the stiffening member 31 includes a tapered section 76 ending at a ball 78. The ball 78 will protect the catheter body from being pierced by the stiffening member from the inside such as in the case where the catheter has already been put into a curved configuration and the stiffening member is being advanced into that curved section of the catheter to obtain increased bending stiffness distally. Such may occur where the distal section 32 of the catheter will not remain in position against certain tissue due to heart movement. Rather than piercing the body member, the rounded distal tip of the stiffening member will negotiate the curve of the body member. The remainder of the stiffening member 31 will then follow. The tapered section 76 likewise assists the stiffening member 31 in negotiating already established bends in the catheter. Because the tapered section is of a smaller diameter, it will bend more easily thus enabling the distal end of the stiffening member to bend around the existing catheter bend more easily. As mentioned above, a further advantage of the tapered section/ball combination is shown in FIG. 5 where different radii of bends are possible thereby giving the physician greater steering control.
The deflection wire 23, the stiffening member 31, and the torque control layer 27 resulting in additional torsional rigidity, allow the physician using the catheter to more easily and accurately advance the catheter through a patient's vascular system into the beating heart. The physician can more easily adjust the shape and stiffness of the distal portion 13 of the catheter 10 to place the distal portion at a desired location against a ventricle wall for example in a desired orientation. This degree of control provides the physician with greater versatility in accurately placing the catheter at the desired location in order to better determine the site from which the arrhythmia originates and to more accurately place the ablation electrode against the originating site of the arrhythmia to effectively ablate the conductive tissue at the site to eliminate or moderate the arrhythmia while the heart is beating. The position of the stiffening member 31 may be adjusted to result in greater or lesser bending stiffness as required. For example, when the catheter is placed against a beating heart and increased bending stiffness is needed to keep it in position, such stiffness may be attained by advancing the stiffening member towards the distal end of the catheter. Where less bending stiffness is required, the stiffening member may be retracted towards the proximal end of the catheter.
FIG. 7 illustrates an alternative embodiment to the catheter body member 11 construction shown in FIGS. 1-3. In this embodiment, the inner tubular member 25 is provided with a plurality of open channels formed in its exterior which are adapted to receive the electrical conductors 16 in addition to a plurality of deflection control systems 18. In this embodiment four sensing electrodes are provided on the distal portion of the catheter. The electrical conductor 17 connected to the ablation electrode 14 is shown extending through the central inner lumen 15. However, it may be disposed within a different channel which may be formed in the exterior of the tubular member 25 in order to provide a stiffening member within the inner lumen 15 as in the previously discussed embodiment. The channels are closed by the tubular layer 27.
The details of the manipulating handle 20 on the proximal end of the catheter 10 are shown in detail in FIGS. 8 and 9. The handle 20 generally includes a body 40, a tubular body member 41 having a proximal end seated within a recess provided within the body. A slide element 43 is slidably mounted about the cap 42 and an elongated female threaded element 44 which acts as a nut and which rotates within the body 40. The distal portion of the female threaded element 44 is provided with a plurality of longitudinally extending ridges 45 on the exterior thereof which are adapted to be slidably received within the interior surface of the slide element 43. Therefore, rotating the slide element 43 will cause rotation of the threaded element 44. A hollow male threaded element 47 is slidably disposed about the body member 41 and is threadably engaged within the female threaded element 44. The male threaded element 47 has an inward projection 48 to which the proximal end of the stiffening member 31 is suitably secured such as by crimping or insert molding. A ring 49 is seated within a shoulder 50 provided on the interior of the slide element 43 and the ring 49 has an inward projection 51 to which is secured the proximal end of the deflection wire 23. In the preferred embodiment, the shoulder is formed by two parts fastened together by screws as shown in FIG. 8. The inward projections 48 and 51 are located in the longitudinal slot 60 in the shaft 41, and are thus restricted from rotating. The proximal end of the catheter body member 11 is secured to the cap 42 such as by adhesive. Therefore, rotating the handle 20 will result in rotation of the body member 11.
Longitudinal movement of the slide element 43 in the proximal direction by an operator will move the ring element 49 longitudinally in the proximal direction causing tension to be applied to the deflection wire 23 which is secured to the inward projection 51 of the ring 49 and thereby curves the distal portion 13 of the catheter body member 11. Longitudinal movement in the distal direction will lessen the tension applied to the deflection wire 23 and allow the distal portion 13 to return to its normal shape, which is usually straight. The slide element 43 includes a groove 62 into which the digit or digits of the operator may reside when moving the element. The surfaces 64 and 66 on either side of the groove would be used to receive the force applied by the operator's digits to move the slide element 43. This results in more positive control over the slide element and increased convenience in operation.
Rotation of the slide element 43 by the operator will rotate the female threaded element 44, which in turn will move the hollow male threaded element 47 along the body member 41 and result in the longitudinal movement of the stiffening member 31 which is connected to the inward projection 48 on the male threaded element 47. The stiffening member 31 must have sufficient column strength to communicate the thrust applied to the proximal end to the distal end thereof and to otherwise stiffen the distal portion 13 of the catheter body member 11.
Turning briefly to FIG. 12, the movement of the knob 43 in two planes can be seen. In the first plane 62, the knob 43 slides in a direction parallel to the longitudinal axis 64 of the catheter 20 for control over the deflecting wire 23, as shown by the arrows 65 drawn in parallel with the longitudinal axis. In the second plane 66, the knob 43 rotates as shown by the curved arrows 68, to control the position of the stiffening member. These planes are perpendicular to each other in this view. It may also be noted that the handle body 40 includes a larger diameter portion 70 at its proximal end. The body 40 is smoothly tapered up to that enlarged diameter portion 70. The existence of this enlarged portion 70 provides a physical indicator to the physician as to the location of his or her hand on the handle 40. The physician can tell how far back his or her hand is on the handle based on the feeling imparted to the hand by the differences in diameter along the handle.
The cap 42 or female threaded element 44 may include indicia, such as the color red, placed at a certain point on its outer surface to establish a position reference system. Upon moving the slide element 43 far enough distally to reveal the red indicia on the cap, the operator would then be made aware that he or she has reached a predetermined position. Alternately, the indicia may include gradations marked on the cap.
Electrical conductors 16 and 17 (not shown in FIG. 8 or 9) pass through the inner lumen 52 of the tubular shaft 41 and are electrically connected to the electrical connector 53 shown on the proximal end of the handle 20 in FIG. 8. A suitable connector 53 is the Model No. V114RC72 sold by Alden Products Company, located in Brockton, Mass. Other suitable electrical connectors are commercially available.
In one presently preferred embodiment of the invention, the tubular sheath member 24 about the deflection wire 23 has an outer diameter of about 0.015 to about 0.020 inches (0.38 to 0.51 mm) and an inner diameter of about 0.008 to about 0.012 inches (0.20 to 0.31 mm). The layer 27 formed of multifilament strands 28 and polymer matrix 29 has a wall thickness of about 0.003 to about 0.005 inches (0.08 to 0.013 ram) and the outer jacket or coating 26 has a wall thickness of about 0.004 to 0.007 inches (0.10 to 0.18 ram). The outer diameter of the catheter may range from about 0.079 to about 0.12 inches (2.01 to 3.05 mm) and the overall length of the catheter 10 may range from about 39.4 to 51.2 inches (100 to about 130 cm). The sensing electrodes 12 on the distal end are preferably formed of platinum or a platinum alloy and are about 0.030 to 0.079 inches (0.75 to about 2.0 ram) in width and are spaced along the length of the distal portion about 0.079 to 0.394 inches (2 to about 10 mm) apart. A preferable spacing is about 0.20 inches (5 mm). The ablation electrode which is about 0.16 inches (4 mm) long is also preferably formed of platinum or a platinum alloy, or platinum coated stainless steel.
The inner tubular member 25 is formed from a thermoplastic elastomer having a Shore hardness from about 75A to about 75D, preferably about 85A to about 55D and is preferably a thermoplastic polyurethane. Suitable polyurethanes include Tecothane® which is available from Thermedics, Inc. Alternative materials include Pebax® which is a thermoplastic elastomer available from the Atochem Company. The polymer matrix 29 is formed of a thermosetting polymer and preferably is an epoxy adhesive such as FDA2. The multi-filament strands 28 may be formed of high strength polymeric materials such as aramid (Kevlar®) available from E.I. dupont, deNemours & Co., Inc. The fibrous strands compress into a ribbon-like shape when braided.
The outer jacket or coating 26 is preferably formed of a thermoplastic polymeric material having a Shore hardness of about 85A to about 75D, preferably about 95A to about 65D. Suitable polymers include a polyurethane made with a polytetramethylene glycol ether which is available commercially as 2363 55DE Pellethane from the Dow Chemical Company or a polyurethane such as TT 2055D B320 Tecothane which is available from Thermedics. Other suitable thermoplastic polymeric materials may be employed.
Both the inner tubular member 25 and the outer jacket 26 may have incorporated therein a radiopaque material such as barium sulfate to facilitate the fluoroscopic observation during the procedure by the physician in attendance.
The electrical conductors 16 and 17 may be 30-40 awg copper wires with a suitable insulation, such as a polyamide, polyurethane/nylon, or a fluoropolymer such as poly(tetrafluoro)ethylene. The deflection wire 23 and stiffening member 31 are formed of a stainless steel suitable for in vivo use. The deflection wire 23 is about 0.005 to about 0.010 inch (0.127 to 0.254 mm) in diameter and the stiffening member 31 is about 0.010 to about 0.020 inch (0.254 to 0.508 ram) in diameter, and the lengths thereof are appropriate for the catheter in which they are utilized.
The catheter 10 can be conveniently made by the following procedure. Multi-filament strands 28 are braided about the inner tubular member 25 along the length thereof. The braiding may be terminated short of the distal portion 13 or the entire length of the inner tubular member 25 may be braided and the braided portion on the distal portion 13 may be removed. Matrix 29 is formed either by impregnating the braided product with a suitable impregnate or incorporating matrix material with the strands prior to braiding and then heating the braided product to form the matrix. To complete the catheter body member, a heat shrinkable thermoplastic tubular member or sleeve which forms the outer jacket 26 is fitted onto the braided and impregnated reinforcing layer 27, and then a heat shrinkable tubular element (not shown) is fitted over the thermoplastic tube forming the outer jacket 26 and the assembly is then heated by hot air to shrink the heat shrinkable tube and press the thermoplastic tube against the exterior of the reinforcing layer 27 to secure the jacket 26 thereto. Upon cooling, the heat shrinkable tube is stripped off and discarded and the catheter is then ground to the desired outer diameter.
Electrical conductors 16 and 17 are advanced through the inner lumen 15 of the inner tubular member 25 and electrically connected by soldering to the sensing electrodes 12 and the ablation electrode 14 respectively. The electrodes 12 are slid over the distal portion 13 and secured to the exterior thereof by a suitable adhesive. Ablation electrode 14 is similarly secured to the distal tip of the catheter after conductor 17 is soldered thereto. The stiffening member 31 is passed proximally through the inner lumen 15 and is secured by its proximal end to the inward projection 48 on the male threaded element 47 on the manipulating handle 20 by suitable means such as brazing or soldering or by an adhesive. The deflection wire 23 is advanced through the lumen 21. The proximal end of the deflection wire 23 is secured by the same or similar means to the inward projection 51 on the ring 49. The distal end of the deflection wire 23 is secured by the same or similar means to the anchor plate 19 as shown in FIG. 10. In this instance a transverse slit is formed in the distal portion 13, the anchor plate 19 is adhesively bonded to the proximal facing of the slit and then the distal facing of the slit is adhesively bonded to the anchor plate and the proximal facing of the slit. An alternative embodiment is shown in FIG. 11 wherein an anchor cylinder 55 is provided which encircles and is secured to the inner tubular member 25, and has a linear depression or groove 56 which is seated into the open channel 30. In the latter instance, the deflection wire 23 is suitably secured such as by soldering within the groove 56. The anchor plate 19 and the anchor cylinder 55 may be formed of suitable high strength material such as stainless steel.
While the invention has been described herein in terms of certain preferred embodiments, those skilled in the art of catheters for performing electrophysiological procedures within a patient will recognize that various modifications and improvements can be made to the invention without departing from the scope thereof. Although preferred and alternative embodiments of the invention have been described and illustrated, it is clear that the invention is susceptible to numerous modifications and adaptations within the ability of those skilled in the art and without the exercise of inventive faculty. Thus, it should be understood that various changes in form, detail and usage of the present invention may be made without departing from the spirit and scope of the invention.
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A catheter adapted to perform electrophysiological procedures comprises a body member, a manipulation handle attached to the proximal end of the body member for applying torque to the body member, the handle having a control knob adapted for control movements in a first plane and in a second plane simultaneously. A deflection control line is attached at its distal end to the distal portion of the catheter and its proximal end attached to the control device of the handle so that tension applied to the control line by sliding the control knob causes deflection of the distal portion of the catheter. A stiffening member is disposed within the body member of the catheter and is slidable, said stiffening member providing increased rigidity to the portion of the body member in which the stiffening member is located. Rotation of the control knob controls the position of the stiffening member in the body member. In a further aspect, a stiffening member in accordance with one embodiment includes a tapered distal end section with a ball formed on the distal tip, the tapered section terminating at the ball. In accordance with another aspect, the torsional rigidity of the catheter body is increased by use of a layer of aramid fibers mixed with an epoxy. In yet another feature, the handle and rotatable sliding element are symmetrically shaped to facilitate complete single-handed operation of the handle by the physician of all position control aspects of the catheter.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a method of operating an internal combustion engine, more specifically a diesel combustion engine.
2. The Prior Art
Combustion processes for diesel combustion engines with substantially homogeneous combustion—what are termed alternative diesel combustion processes—make it possible to drastically reduce engine emissions. Specifically, concurrent reduction of NO x and of particles in the engine exhaust is thereby possible. These new combustion processes rely on homogenization of the in-cylinder charge prior to the combustion event. Diesel combustion engines with homogeneous combustion are known from the printed documents U.S. Pat. No. 5,832,880 A, U.S. Pat. No. 6,260,520 B1, U.S. Pat. No. 6,276,334 B1 or from U.S. Pat. No. 6,286,482 B1.
As contrasted with conventional combustion processes, it can be observed in alternative combustion processes that the engine exhausts (NO x , particles, HC, CO and noise) are much more sensitive to the engine operation parameters (injection timing, exhaust gas recirculation rate, fresh air temperature, temperature of the intake manifold, pressure in the intake manifold, exhaust back pressure, coolant temperature, atmospheric pressure). In reverse, changing quite slightly, by a few percent, the exhaust gas recirculation rate suffices to considerably change the NO x emissions for example. In this context, FIG. 1 shows the influence of the exhaust gas recirculation rate and of injection timing on the NO x emission of the engine during alternative combustion. As can be seen from FIG. 2 , injection timing and exhaust gas recirculation rate also have considerable influence on particle emission. A slight change in injection timing suffices to heavily influence particle emission.
This fact is at the origin of the need for exactly complying with the engine operation parameters required for alternative combustion processes in order to be able to tap the full potential of alternative diesel combustion processes. With the currently utilized methods for computing certain engine operation parameters (such as injection timing and desired value for the exhaust gas recirculation rate) the control within the engine control system is a simple control as a function of engine speed and engine load, that is to say there is no so-called “closed loop” control. For conventional combustion processes, which have far less sensitiveness between the engine operation parameters and the resulting engine emissions, this simple control is sufficient. Using alternative combustion processes for diesel engines, these control processes however are insufficient because of the sensitiveness described so that the search for new methods continues. The reason therefor is that in the simple control calculation of certain engine operation parameters such as injection timing and exhaust gas recirculation rate currently used, the influence of engine speed, engine load, fresh air temperature, atmospheric pressure and coolant temperature is only taken into consideration statically in characteristic diagrams or lines within the engine control system.
When operating a diesel engine with alternative combustion together with the currently used control strategy, two critical operating conditions occur. Firstly, if the exhaust gas recirculation rate is too high, combustion becomes instable. The 50% mass fraction burned is too near top dead center, which results in incomplete combustion with high emissions (HC and CO) and in an instable engine torque. Secondly, if the exhaust gas recirculation rate is too low, the 50% mass fraction burned is advanced, this involving considerable increase of combustion noise.
A system for controlling the exhaust gas recirculation rate in a compression ignition internal combustion engine is known from DE 31 34 631 A1, in which a desired value for ignition delay is determined and the actual value of ignition delay is controlled to match this desired value. The desired value for ignition delay thereby originates from an engine characteristic map. Ignition delay time is obtained comparing the signals, for example the start of injection by an injection nozzle and of a pressure sensor connected to the combustion chamber.
An automatic control for a self-igniting internal combustion engine in which the in-cylinder peak pressure is measured and compared with a desired value is known from GB 2 091 000 A. The control variable changed as a result of this difference is injection timing.
Both in DE 31 34 631 A1 and in GB 2 091 000 A, only one control variable is changed. This is not sufficient for controlling a diesel combustion engine with homogeneous combustion.
The most important variables for determining the combustion process in an internal combustion engine are the phasing of the combustion process or of start of combustion, the maximum speed of pressure increase in the cylinder, and the peak pressure.
In an internal combustion engine in which combustion substantially occurs through self-ignition of a directly injected quantity of fuel, the determining variables are mainly determined by injection timing, charge composition and ignition delay. These parameters are in turn determined by a great number of influencing variables such as speed, fuel quantity, intake temperature, boost pressure, effective compression ratio, inert gas content of the in-cylinder charge and component temperature.
Conventional diesel combustion essentially is a diffusion process in which air and fuel are not mixed together but separately delivered to the combustion zone. Conventional diesel combustion is characterized by the inhomogeneous distribution of air and fuel. The concentration of the fuel in the injection spray decreases continuously from the inside to the outside toward the region of the surrounding air-residual gas mixture. Combustion in zones at air conditions within the range of stoichiometric air ratio and below leads to high peak temperatures resulting in thermal NO x formation. Further, lack of oxygen in rich zones combined with high temperatures results in the formation of soot.
A more stringent legal framework makes it necessary to always find new ways for designing combustion processes in order to reduce emission of soot particles and NO x emission in diesel combustion engines.
It is known to reduce NO x and soot emission in the exhaust by increasing ignition delay, advancing therefor the ignition timing so that combustion occurs through self-ignition of a lean fuel-air mixture. A possible variant thereof is termed HCLI process (Homogeneous Charge Late Injection). When such mixture combustion is carried out, fuel injection occurs sufficiently far from the top dead center of the compression period, so that a largely homogeneous fuel-air mixture is obtained. Exhaust gas recirculation permits to keep combustion temperature below the minimum temperature needed for NO x to be generated. Since homogenization of fuel and air is time-dependent, the realization of this process is restricted, being dependent both on speed and on charge, as particle emission increases if homogenization is insufficient.
U.S. Pat. No. 6,338,245 B1 describes a diesel combustion engine relying for operation on the HCLI process in which combustion temperature and ignition delay are adjusted so that at lower and medium part load the combustion temperature is lower than the NO x formation temperature and the air ratio is greater than the value that is relevant for soot formation. The combustion temperature is thereby controlled by changing the exhaust gas recirculation rate and ignition delay, by fuel injection timing. At medium and high load, the combustion temperature is lowered to such an extent that the formation of both NO x and soot is avoided. The disadvantage thereof is that, at medium part load particularly, a low air ratio occurs together with low combustion temperatures with poor efficiency trade-off.
U.S. Pat. No. 6,158,413 A describes a direct injection diesel combustion engine in which fuel injection is not set to take place before compression top dead center and in which oxygen concentration in the combustion chamber is minimized through exhaust recirculation. This method of operation is also termed the HPLI process (Highly Premixed Late Injection). Due to the temperature level that decreases after top dead center—as compared to a conventional injection before top dead center—and to the increased quantity of recirculated exhaust over conventional operation, ignition delay is longer than in what is termed diffusion combustion. The low temperature level controlled by the exhaust gas recirculation rate causes the combustion temperature to remain below the value relevant for NO x formation. The long ignition delay effected by the later ignition time permits to obtain a good blend so that, as a result thereof, the local lack of oxygen during combustion of the mixture is significantly reduced and the formation of particles is decreased. Retarding the combustion process results in a lower maximum temperature but at the same time in a higher mean temperature at a given late crank angle so that the burning off of soot is enhanced. Moreover, causing combustion to occur in the expansion stroke together with the high exhaust gas recirculation rate leads, in spite of the larger quantity of pre-mixed fuel due to the long ignition delay and, as a result thereof, in spite of the higher maximum combustion rate, to an in-cylinder pressure increase rate that does not exceed the admissible value. The disadvantage thereof is the poor efficiency in the lower part load range.
The Austrian Utility Model Application GM 702/2002 suggests operating a diesel combustion engine in the lower part load range in the HCLI mode, in the medium part load range in the HPLI mode and in the full load range with conventional diesel combustion. As a result, the internal combustion engine can be operated with high efficiency and low NO x and soot emissions in any load range.
The HCLI process and the HPLI process pertain to the alternative diesel combustion processes.
It is known to determine injection timing for the fuel on the basis of engine operation parameters or through the control of characteristic diagrams. It is further known to compute injection timing through a combustion regulator with feedback on the actual combustion situation. For stationary condition, injection timings determined in this manner are sufficient.
In dynamic operation of the engine though, transiently occurring differences in the in-cylinder charge as compared to the stationary desired values result in a difference between the resulting combustion noise and the stationary desired values.
A method for controlling an internal combustion engine is known from DE 43 22 319 C2 in which a first actual value is prescribed starting from a value λ and said first actual value and a first desired value are prescribed by a first control means, starting from a first control variable. Further, a second actual value can be prescribed from a quantity of air and, starting from said second actual value and a second desired value, a second control variable is prescribed by a second control means. The desired values are thereby chosen so that, if certain operating conditions are given, the desired values are prescribed for the quantity of air, and if these certain operating conditions are not given, desired values are prescribed for the value λ.
It is known to determine start of injection or combustion situation in an internal combustion engine using for example an in-cylinder pressure sensor and to obtain therefrom control signals for controlling the internal combustion engine such as injection timing. DE 197 49 817 A1 suggests computing the start of injection and the combustion situation from the measured pressure history and from the calculated pressure history.
It is the object of the invention to control combustion in a diesel combustion engine with homogeneous combustion in the simplest possible way and with the greatest possible accuracy. It is another object to develop a method by means of which the internal combustion engine can be operated in the optimal mode at each operating point. It is still another object of the invention to propose a method of operating an internal combustion engine by means of which, in dynamic operation of the engine, the combustion noise can, as far as practicable, be kept at the values of the stationary engine operation.
SUMMARY OF THE INVENTION
In accordance with the invention, this makes it possible to detect a condition variable in the cylinder, preferably the pressure, the temperature, the ion flow or the output signal of an optical principle of measurement as a function of the crank angle and to obtain therefrom a signal about the cylinder condition, to determine from the cylinder condition signal at least two characteristic cycle values from the group comprising mass fraction of the injected fuel burned, maximum pressure increase in the cylinder, combustion noise, start of combustion or duration of combustion, to compare the determined characteristic cycle values with desired values for the characteristic cycle values entered in a characteristic diagram and to compute a given difference between the two values and to supply the difference to a regulation algorithm and to adjust as a correcting variable the time of fuel ignition of at least one injection event and/or the inert gas fraction in the cylinder in order to stabilize combustion and/or to minimize noise and exhaust emission. This makes it possible to stabilize combustion and to minimise noise and exhaust emission. Preferably, there is provided that the 50 % mass fraction burned of the injected fuel and the maximum in-cylinder pressure increase is determined.
The newly developed method relies on the reflection consisting in dynamically calculating certain engine operation parameters such as injection timing and inert gas fraction in the cylinder rate depending on variables that describe the actual condition inside the cylinder.
In order to detect the actual condition of the cylinder, a sensor detects for example the in-cylinder pressure as a function of the crank angle. Then, certain characteristic cycle values are calculated from this sensor signal in an interval of 720° crank angle. Accordingly, in-cylinder pressure history is described by two characteristic values computed from the pressure history itself.
These two characteristic values more specifically are the timing of the 50% mass fraction of the injected fuel burned and the maximum in-cylinder pressure increase. Combustion noise, start of combustion or duration of combustion may also be utilized as characteristic cycle values to describe the combustion process.
The characteristic cycle values may be determined either from the output signal of a sensor, making use of an acoustic, optical, electrical, thermodynamic or mechanical principle of measurement or through a mathematical model. A combination of a sensor-based approach with a model-based approach may also find application.
Within the scope of the method developed, each of the actual characteristic cycle values developed are then compared with the desired value for the characteristic cycle values each entered in a characteristic diagram depending on the engine speed and the engine load, and a given difference between the two values is calculated. This difference is next supplied to a regulation algorithm. The regulator dynamically calculates the new engine operation parameters such as injection timing and recirculated exhaust mass needed in order to maintain the desired cylinder condition. A precontrol value entered in a respective characteristic diagram is added to the values calculated by the regulator in order to improve the dynamics of the system as a whole.
As contrasted with conventional control processes, the method of the invention also allows for stable control of the combustion process with optimum emission conditions even in the transient mode, the timing of fuel injection being controlled by at least one injection event and the maximum in-cylinder pressure increase being concurrently controlled via the inert gas fraction in accordance with the values prescribed by the regulator. In accordance with an advantageous implementation variant of the invention, there is provided that the correcting variables timing of fuel injection of at least one injection event and inert gas fraction inside the cylinder be adjusted simultaneously by means of the regulation algorithm.
To control the inert gas in the cylinder, there may be provided that the supply and variation of the inert gas mass in the cylinder be carried out through external exhaust gas recirculation or through in-cylinder exhaust gas recirculation or by combining internal and external exhaust gas recirculation.
Within the scope of the invention, the following steps are provided to resolve the problem posed:
selecting at least one, preferably at least two, characteristic engine operation parameters, entering at least one threshold value for each selected characteristic engine operation parameter, associating value ranges separated by at least one threshold value with each engine operation parameter, at least one first value range being associated with the first mode of operation and at least one second value range being associated with the second mode of operation, comparing the actual values of the selected characteristic engine operation parameters with the value ranges, switching to the second mode of operation or remaining in the second mode of operation when all the selected characteristic engine operation parameters lie within the second value ranges.
Preferably, there is provided that switching to the first mode of operation occurs or that the first mode of operation is maintained when at least one actual value of a selected characteristic engine operation parameter lies within the first value range.
At least two characteristic engine operation parameters are selected from the group comprising engine speed, engine load, engine coolant temperature, atmospheric pressure, temperature of the exhaust gas after-treatment system, exhaust gas temperature upstream of the exhaust gas after-treatment system, exhaust gas temperature downstream of the exhaust gas after-treatment system, speed of the engine speed change, speed of the engine load change and actual transmission ratio of the driving train. The engine load may thereby be defined for example by the torque, the injected quantity or the position of the accelerator pedal. An oxidation catalytic converter is preferably provided as an exhaust gas after-treatment system. The actual transmission ratio of the driving train is advantageously defined by the number of the gear.
The first mode of operation is preferably associated with the conventional diesel combustion and the second mode of operation, with an alternative diesel combustion method.
Each of the selected characteristic engine parameters is at least compared with a threshold value that has been entered. For each of the engine operation parameters used, the threshold values are stored either as fixed values (e.g.: upper threshold value for engine speed of about 4,000 rpm) or as dependent values (e.g.: characteristic line against the engine speed, characteristic line against the engine speed and the engine load). The threshold values may also have a hysteresis, i.e., the threshold values are dependent on the direction in which the engine operation parameter of concern changes. If every engine operation parameter selected lies within the admissible value range defined by the corresponding threshold values, switching from conventional to alternative diesel combustion occurs. As soon as one of the input variables leaves the admissible value range defined by the corresponding threshold values, switching from alternative to conventional diesel combustion occurs.
Further, the solution of the problem is achieved by the following steps:
determining a desired value for injection timing and/or a combustion situation, determining a desired value for the ratio fresh air mass to inert gas mass inside the cylinder and/or for the air/fuel ratio in the exhaust, measuring or computing an actual value for the ratio fresh air mass to inert gas mass inside the cylinder and/or for the air/fuel ratio in the exhaust, calculating the difference between the desired value and the actual value of the ratio fresh air mass to inert gas mass inside the cylinder or of the air/fuel ratio in the exhaust, correcting the desired value of injection timing or the combustion situation as a result of the difference between the desired value and the actual value of the ratio fresh air mass to inert gas mass or of the air/fuel ratio in the exhaust.
The desired values can be calculated from at least one actual engine parameter or selected from data filed in a characteristic diagram.
If injection timing is determined by simple control, that is to say without any feedback about the actual combustion situation, this predetermined injection timing can be corrected dynamically. Correction is thereby performed as a function of the difference between the desired value required for the ratio fresh air mass to inert gas mass and the measured and/or calculated actual value for the ratio fresh air mass to inert gas mass inside the cylinder. If the actual value for the ratio fresh air mass to inert gas mass is smaller than the desired value for the ratio fresh air mass to inert gas mass, with the inert gas mass fraction inside the cylinder being too high or the fresh air mass fraction too low as a result thereof, injection timing is advanced. If the actual value for the ratio fresh air mass to inert gas mass is higher than the desired value for the ratio fresh air mass to inert gas mass, with the inert gas mass fraction being too low or the fresh air mass fraction too high as a result thereof, injection timing is retarded.
As an alternative or in addition thereto, correction may be performed as a function of the difference between the desired value required for the air/fuel ratio in the exhaust gas and the measured and/or calculated actual value for the air/fuel ratio in the exhaust gas. If the actual value of the air/fuel ratio in the exhaust gas is smaller than the desired value of the air/fuel ratio in the exhaust gas, with the inert gas mass fraction in the cylinder being too high as a result thereof, injection timing is advanced. If, by contrast, the actual value of the air/fuel ratio in the exhaust gas is greater than the desired value of the air/fuel ratio in the exhaust gas, with the inert gas mass fraction in the cylinder being too small as a result thereof, injection timing is retarded.
If injection timing is calculated through a combustion controller, meaning in a closed loop controller with feedback about the actual combustion situation, the desired value for the combustion situation is corrected dynamically, for example additively. Correction may thereby be performed as a function of the difference between the desired value for the ratio of fresh air mass to inert gas mass and the actual value measured and/or calculated for the fresh air mass to inert gas mass ratio inside the cylinder. If the actual value for the ratio of fresh air mass to inert gas mass is smaller than the desired value for the ratio of fresh air mass to inert gas mass, with the inert gas mass fraction in the cylinder being too high or the fresh air mass fraction too low as a result thereof, the required desired value for the combustion situation is advanced. If, by contrast, the actual value of the ratio of fresh air mass to inert gas mass is greater than the desired value for the ratio of fresh air mass to inert gas mass, with the inert gas mass fraction in the cylinder being too low or the fresh air mass fraction too high as a result thereof, the required desired value for the combustion situation is retarded. Likewise, correction may be determined as a function of the difference between the required desired value of the air/fuel ratio in the exhaust gas and the actual value measured and/or calculated for the air/fuel ratio in the exhaust gas. If the actual value of the air/fuel ratio in the exhaust gas is smaller than the desired value of the air/fuel ratio in the exhaust gas, with the inert gas mass fraction in the cylinder being too high as a result thereof, the required desired value for the combustion situation is advanced. If, by contrast, the actual value of the air/fuel ratio in the exhaust gas is greater than the desired value of the air/fuel ratio in the exhaust gas, with the inert gas mass fraction in the cylinder being too small as a result thereof, the required desired value for the combustion situation is retarded.
By correcting injection timing and/or the combustion situation as a function of the difference between the actual and the desired values for the ratio fresh air mass to inert gas mass in the cylinder and/or the air/fuel ratio in the exhaust gas, a difference between the transient and the stationary combustion noise resulting from transiently occurring differences between the cylinder charge and the stationary desired value may be avoided in dynamic engine operation.
The invention will be described in closer detail herein after with reference to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the influence of the injection timing and of the exhaust gas recirculation rate upon NO x engine emission,
FIG. 2 the influence of the injection timing and of the exhaust gas recirculation rate upon particle emission,
FIG. 3 an in-cylinder pressure—crank angle diagram,
FIG. 4 schematically a regulator structure of the method of the invention,
FIG. 5 the influence of fuel injection timing upon the location of the 50% mass fraction burned,
FIG. 6 the influence of the inert gas mass upon the maximum in-cylinder pressure increase,
FIG. 7 the correlation between the maximum in-cylinder pressure increase and the resulting combustion noise in the case of alternative combustion,
FIG. 8 a valve lift—crank angle diagram for internal exhaust recirculation,
FIG. 9 a diagram with different engine parameters when carrying out the method of the invention,
FIG. 10 a speed—time diagram,
FIG. 11 a torque—time diagram,
FIG. 12 a 50% mass fraction burned—time diagram,
FIG. 13 an engine noise—time diagram for transient engine operation when carrying out the method of the invention,
FIG. 14 schematically the decision structure for switching between the operating modes,
FIG. 15 a representation explaining the dynamic correction of injection timing during controlled operation, and
FIG. 16 a representation explaining the dynamic correction of the desired value of the combustion location during regulated operation.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
With alternative combustion processes relying for operation on homogenization of the cylinder charge prior to the combustion event, a considerably higher sensitiveness of engine emission (NO x , particles, HC, CO and noise) to the engine operation parameters (injection timing, exhaust gas recirculation EGR rate, fresh air temperature, temperature of the intake manifold, pressure in the intake manifold, exhaust back pressure, coolant temperature, atmospheric pressure) over conventional combustion processes can be observed. FIG. 1 illustrates by way of example the influence of the exhaust gas recirculation rate EGR and of injection timing SOE before top dead center upon NO x engine emission during alternative combustion. It can be seen that changing the exhaust gas recirculation EGR rate by a few percent results in a significant change in NO x emission. FIG. 2 shows by way of example the influence of injection timing SOE before top dead center of combustion and of the exhaust gas recirculation EGR rate upon particle emission Soot during alternative combustion. A slight change of injection timing SOE strongly affects particle emission Soot.
Using the method described, the in-cylinder pressure is detected by a sensor as a function of the crank angle CA for detecting the actual cylinder condition. Next, certain characteristic variables are calculated from this sensor signal in an interval of 720° crank angle CA, in the exemplary embodiment these variables being the timing of 50% mass fraction of the injected fuel burned MFB50% and the maximum in-cylinder pressure increase Δp max for each degree crank angle CA. By way of example, in FIG. 3 the in-cylinder pressure p is plotted down the side of the diagram whereas the crank angle CA is plotted on the horizontal axis and the maximum in-cylinder pressure increase Δp max as well as the 50% mass fraction burned MFB50% for a certain injection time and a certain exhaust gas recirculation rate are plotted in this diagram. Combustion noise S, start of combustion or the combustion duration may also be used as characteristic variables to describe the combustion. The characteristic cycle values are determined either by virtue of the output signal of a sensor, making use for this purpose of an acoustic, optical, electrical, thermodynamic or mechanical principle of measurement or through a mathematical model. A combination of a sensor-based approach with a model-based approach may also find application.
In the method developed, each of the actual characteristic cycle values obtained (time of the 50% mass fraction of the injected fuel burned MFB50% and the maximum pressure increase Δp max ) is compared with the desired values MFB50% desired and Δp max for the characteristic cycle values that are each stored in a characteristic diagram as a function of engine speed n and engine load L, and an existing difference between these two values is calculated.
This difference is supplied to a regulation algorithm. A possible regulation structure is illustrated by way of example in FIG. 4 . The PID controller dynamically calculates, on the basis of the difference between the desired value for 50% mass fraction burned MFB50% desired and the actual value of 50% mass fraction burned MFB50% and of the difference between the desired value for the maximum in-cylinder pressure increase Δp max, desired and the actual value of the maximum in-cylinder pressure increase Δp max , the operation parameters needed for maintaining the desired cylinder condition, namely injection timing SOE and the exhaust gas recirculation rate EGR, for actuating the injection valve and the EGR valve or for actuating an intake valve during the exhaust stroke (or an exhaust valve during the intake stroke). A precontrol value SOEv and EGRv stored in a characteristic diagram and being for example a function of the engine speed n and the engine charge L is added to the value calculated by the PID controller in order to improve the dynamics of the system as a whole.
The important point with the method developed is that, in order to obtain stable control of alternative diesel combustion processes with optimum emission in the transient mode of operation of the engine as well, the combustion process, which is for example described by the timing of the 50% mass fraction burned MFB50% or of the combustion duration, is influenced, through fuel injection timing SOE calculated by the PID controller, by at least one injection event and the maximum in-cylinder pressure increase Δp max is simultaneously regulated through the inert gas fraction, meaning through the exhaust gas recirculation EGR rate. FIG. 5 illustrates by way of example how the location of the 50% mass fraction burned MFB50% plotted against fuel injection timing SOE in degrees crank angle CA can be influenced before top dead center even if the exhaust gas mass recirculated in the cylinder varies. The lines plotted in FIG. 5 characterize the points of mass fraction burned MFB50% for various exhaust gas recirculation EGR rates, with the lowermost line representing the lowermost exhaust gas recirculation rate. This makes it possible to accommodate temperature changes occurring in the transient engine mode of operation such as intake manifold temperature, exhaust gas temperature or changes in the cylinder charge (e.g., EGR fraction too high) using the method described and, as a result thereof, to ensure stable combustion of the injected fuel with optimal emission.
Additionally, in the method developed, the engine noise emission (described by the the maximum in-cylinder pressure increase Δp max ) is regulated to a desired value through the inert gas fraction in the cylinder charge. FIG. 6 illustrates by way of example how the maximum in-cylinder pressure increase Δp max and the correlated engine noise emission S may be influenced through the inert gas mass contained in the cylinder even if the time of fuel injection SOE varies. The opening duration IVH of at least one intake valve during an exhaust stroke is plotted on the ordinate, this opening duration being directly correlated with the inert gas mass. The lines plotted in the diagram show various fuel injection timings SOE, with the uppermost line representing early, the lowermost line, rather late injection timing. The correlation between the maximum in-cylinder pressure increase Δp max and the resulting combustion noise S during alternative combustion is illustrated in FIG. 7 . The lines therein show various fuel injection timings SOE.
In the method developed, the inert gas mass in the cylinder can be delivered and varied either through external recirculation (that is outside of the cylinder head) or through in-cylinder recirculation (e.g., through variable intake and exhaust valve timing) or through a combination of the two kinds of recirculation.
Changing the recirculated exhaust mass by varying the intake manifold pressure (e.g. through a throttle valve or a turbocharger) or by varying the exhaust back pressure (e.g., through an exhaust turbocharger with variable through flow cross section on the side of the turbine) may also be utilized.
In the method described, the pressure history sensed by an in-cylinder pressure sensor and a speed sensor serves as a feedback on the actual condition of the combustion within the cylinder. Next, two characteristic values (time of the 50% mass fraction burned MFB50% of the injected fuel and the maximum in-cylinder pressure increase Δp max ) for characterizing the combustion are calculated from the pressure history. The target values for the two characteristic values are stored in characteristic diagrams that are at least dependent on speed and charge.
The present method for regulating alternative diesel combustion processes substantially differs from known methods by the following points:
1. Through a regulation algorithm, the fuel injection timing SOE and the inert gas mass are concurrently influenced on the basis of the differences between the actual characteristic values determined from the pressure history and the desired target values. 2. Accordingly, the 50% mass fraction burned MFB50% and the maximum in-cylinder pressure increase Δp max are, within the physically possible limits, simultaneously and independently of one another set on the desired target values. 3. The method also accommodates a change of parameters outside the cylinder (such as atmospheric pressure, intake air temperature, coolant temperature, exhaust back pressure, intake manifold pressure, fuel pressure) while concurrently maintaining the target values demanded (timing of the 50% mass fraction burned MFB50% of the injected fuel and maximum in-cylinder pressure increase Δp max ).
As a possible application of the method, the timing of the 50% mass fraction of the injected fuel burned MFB50% is regulated through the injection timing SOE. The maximum in-cylinder pressure increase is influenced through in-cylinder exhaust gas recirculation. The in-cylinder exhaust gas recirculation is thereby realized by additionally opening at least one intake valve during the exhaust stroke. FIG. 8 shows by way of example the valve lift curves for this kind of internal exhaust gas recirculation. The full line shows the opening of the intake valves, the dashed line, the opening of the exhaust valves. In order to influence the mass of the recirculated exhaust gas EGR and, as a result thereof, the maximum in-cylinder pressure increase Δp max , the intake valve opening duration IVH at constant start of opening is changed during the exhaust stroke. Opening at least one exhaust valve during the intake stroke may also be used to carry out an internal exhaust gas recirculation. It is furthermore possible to change the valve overlap in the region of top dead center of the charge changing process in order to influence the internal recirculated mass of exhaust gas.
FIG. 9 shows by way of example events realized with the method developed during alternative diesel combustion in a stationary point of operation (at constant engine speed n and engine load L). The use of the method makes it possible to change e.g., the combustion noise and concurrently to keep constant the location of the 50% mass fraction burned MFB50%. The following engine operation parameters are plotted in the diagram: combustion noise S, maximum in-cylinder pressure increase Δp max , desired maximum in-cylinder pressure increase Δp max, desired , fresh air mass m L , timing of the 50% mass fraction of the fuel burned MFB50%, desired timing of the 50% mass fraction of the fuel burned MFB50% desired , injection timing SOE. The curves are plotted against time t.
The advantages of the method for the transient mode of operation are illustrated in the FIGS. 10 through 13 . If, during alternative diesel combustion, the engine load L ( FIG. 11 ) and the engine speed n ( FIG. 10 ) are changed to higher values simultaneously, for example when the vehicle accelerates, the exhaust gas mass in the cylinder charge is temporarily too high if the method described is not used. Since with conventional methods, the fuel injection timing is controlledly calculated from one or several characteristic diagrams, the fuel injection is too late for the actual in-cylinder gas composition in this period. In conjunction with the exhaust gas recirculation EGR rate, which is too high, this causes the 50% mass fraction burned MFB50% to be retarded ( FIG. 12 ). This causes the engine torque L ( FIG. 11 ) to drop because of the poor efficiency obtained with late combustion. In an extreme case, combustion can tend to become instable (misfiring). This situation is illustrated by the dashed line in the FIGS. 10 through 13 .
Using the method, injection timing SOE is dynamically corrected through the controller in such a manner that the timing of the 50% mass fraction burned MFB50% also meets the value demanded in the transient engine mode of operation ( FIG. 12 ). Combustion is stabilized as a result thereof and the demanded torque history is observed ( FIG. 11 ). Further, the combustion noise S is regulated to the value demanded by concurrently changing the exhaust mass discharged ( FIG. 13 ). The curve of the characteristic variables of the engine speed n, load L, 50% mass fraction burned MFB50% and combustion noise S using the method is illustrated by full lines in the FIGS. 10 through 13 .
FIG. 14 schematically shows the decision structure for switching between the operation modes. In the exemplary embodiment, the characteristic engine operation parameters selected are the engine speed n, the engine charge L and the temperature of the catalytic converter T c . The engine speed n is compared with an upper threshold value n so . The engine charge L is compared with a characteristic line-based upper threshold value for the engine charge L so that depends on the engine speed n. The temperature of the catalytic converter T c is compared with a characteristic diagram-based lower threshold value for the temperature of the catalytic converter T cu that depends on the engine speed n and the engine charge L. The comparative steps are identified by A 1 , A 2 , A 3 . If, in the comparative steps A 1 , A 2 , A 3 , it is found that the engine speed n, the engine charge L and the temperature of the catalytic converter T c each are in the second range of values that is associated with the second mode of operation and is separated from the first range of values by the respective one of the threshold values n so , L so , T Cu , an instruction is given to switch or to remain in the second mode of operation associated with the alternative diesel combustion method by means of an &-link identified by the reference character B. The second mode of operation is denoted with the reference character MOD 2 .
As can be seen from FIG. 15 , an injection timing t Es is calculated in an electronic control unit ECU on the basis of the engine speed n, the engine charge L and other engine operation parameters without feedback about the actual combustion location. The desired value for the ratio fresh air mass to inert gas mass v s within the cylinder or a desired value λ s for the air/fuel ratio λ in the exhaust is computed on the basis of the engine operation point. The actual value v I or λ I of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust is further determined or calculated using measurement techniques. A correction value Δt ES for the desired value of injection timing t ES is determined on the basis of the difference between the desired values v s , λ s and the actual values v I , λ I of the ratio fresh air mass to inert gas mass within the cylinder or of the air/fuel ratio λ in the exhaust. If the actual value v I or λ I of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust is smaller than the desired value v s or λ s of the ratio fresh air mass to inert gas mass of the air mass or of the air/fuel ratio λ in the exhaust, the injection timing t ES is advanced by an additive correction for example. If, by contrast, the actual value v I or λ I of the ratio fresh air mass to inert gas mass or of the air/fuel ratio λ is greater than the desired value v s or λ s of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust, the injection timing t ES is retarded. The result of this process is a corrected injection timing t ES, K .
In the implementation variant illustrated in FIG. 16 , the injection timing t ES, K is calculated through a combustion regulator R v that takes into consideration actual values t vI about the actual combustion situation. In an electronic control unit ECU, a desired value t vs for the combustion situation is determined from the engine speed n and the engine charge L. A desired value v s or λ s for the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust is prescribed on the basis of the operating condition of the engine. The actual value v I or λ I of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust is determined continuously or discontinuously. A correction factor Δt vs for the desired value of the combustion situation t vs is calculated on the basis of the difference between the desired values v s , λ s and the actual values v I , λ I and the desired value t vs for the combustion situation is corrected dynamically, for example additively. If the actual value v I , λ I of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust is smaller than the desired value v s or λ s of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio in the exhaust, the demanded desired value t vs for the combustion situation is corrected by being advanced. If the actual value v I or λ I is greater than the desired value v s or λ s of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust, the demanded desired value t vs for the combustion situation is corrected by being retarded. In the regulator of the combustion situation, the corrected desired value t vs,K is compared with the actual value t vI of the combustion situation and a corrected desired value t ES,K is calculated therefrom for injection timing.
The dynamic correction of injection timing by comparing the actual values v I or λ I with the desired values v s or λ s of the ratio fresh air mass to inert gas mass in the cylinder or of the air/fuel ratio λ in the exhaust permits to avoid, in dynamic engine operation, a difference between the resulting transient and the corresponding stationary combustion noise due to transiently occurring differences of the cylinder charge with respect to the stationary desired value.
The wording of the patent claims filed together with the application is a mere proposal and without prejudice for obtaining a larger patent protection. The applicant reserves the right to claim further features which hereto before have only been disclosed in the specification and/or the drawings.
Backreferences used in the dependent claims are directed to further complement the subject matter of the main claim with the features of a respective one of the dependent claims; they are not to be understood as obviating the right of achieving an independent, subject matter protection for the features of the dependent claims that are referring back.
The subject matters of these dependent claims however also form independent inventions that comprise a design independent of the subject matters of the previous dependent claims.
The invention is not limited to the exemplary embodiment(s) of the specification. Numerous modifications and changes, more specifically such variants, elements and combinations and/or materials that are e.g., inventive by combining or varying discrete features or elements or method steps in conjunction with those described in the general specification and embodiments as well as in the claims and contained in the drawings and that lead, by combining the features, to a novel subject matter or to novel method steps or method step sequences, also as far as they concern methods of manufacturing, inspecting and working, are possible without departing from the scope of the invention.
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According to the invention, noise of an internal combustion engine is reduced by dynamically correcting the moment of injection when the engine is in the transient mode.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This Application claims priority from U.S. patent application Ser. No. 09/584,297 filed May 31, 2000.
BACKGROUND OF THE INVENTION
[0002] Mobile telephones and similar communication devices are rapidly expanding in use and function. Such devices will soon provide Internet access, personal information management, facsimile, messaging, in addition to telephone communication. To accomplish this there is a need to provide keyboards compatible with the more complex applications to which the mobile device will be adapted. Full function keyboards, such as the standard QWERTY typing array of keys and buttons, are difficult to provide while maintaining the compact size required in the mobile device. Such devices on the market today are cumbersome and often require a separate belt pouch for carrying the mobile device on the person of the user. In addition it is necessary to coordinate on screen displays for adaptation to the variety of functions.
[0003] It is a purpose of this invention to provide a simple and inexpensive means of providing a full function keyboard to accommodate the burgeoning applications to which a mobile communication device is adapted.
SUMMARY OF THE INVENTION
[0004] A mobile communication device is constructed having a body in which is mounted a viewing screen for displaying user interface communications. A first panel is fixed to the body and includes one half of a full function keyboard and a back cover. A second panel is pivotally mounted on the body for rotation between two positions, namely, a closed position and an open position. The second panel is constructed with inner and outer surfaces located on opposite sides of the panel which are positioned such that the inner surface faces the keyboard of the first panel and the outer surface is exposed in the closed position. In the open position, the second panel is pivoted approximately 180° so that the outer surface faces away from the user of the mobile device while the inner surface is exposed.
[0005] To enable the device to be operated as a communication device a communication keypad is constructed in the outer surface of the second panel. To provide the second half of the full function keyboard, the inner surface contains a keyboard which is operatively associated with the keyboard of the first panel in the open position. The screen remains exposed in each position of the second panel. The display which appears on the screen is oriented in a manner consistent with the position of panels.
[0006] In another embodiment of this invention, a switch is operatively associated with the moveable second panel to send a signal to the microprocessor controller of the device indicative of the position of the second panel. This information is used by the controller to adjust the function of keys to be consistent with the application for which the second panel is positioned. In particular an array of soft keys is mounted on the body of the display for convenient use. These soft keys have different functions depending on the position of the second panel.
[0007] In a preferred embodiment of this invention an array of three soft keys are positioned about the periphery of the user so that there are always two keys available at the bottom of the display and a third key available at the upper portion of the display. In this arrangement the key pattern is substantially the same irrespective of orientation of the device. The orientation will be horizontal or vertical depending on the position of the second panel. It is a purpose of this invention to provide substantially the same key functions for the key in a particular relative position in both modes of operation. The upper key, right or left, will be the power key and the lower right and left keys will each operate as a soft key to open quick selection profiles. Each key may be assigned a different menu for different key functions.
[0008] Considering first the use of the device with the second panel closed, for example as a mobile telephone, soft keys are arranged at the lower left, the lower right and the upper left of the display screen. In this position, the upper left hand key will operate as the power on/off key. The lower right and left keys operate as a soft key to open quick selection profiles and menus. For an example, one function of the lower keys that may be selected would be as up and down and left and right scroll keys. Other alternate functions may be devised depending on the applications served.
[0009] When the second panel is opened, the assigned function of the lower soft keys is shifted clockwise or counter clockwise by the controller depending on the use orientation of the device with the second panel open. The functions assigned to the newly positioned lower left and right keys will be the same as the keys positioned at these locations in the closed position. The upper key moves to the upper right and will be the power key. The device controller adjusts the assignment of key functions available at a soft key to provide a similar set of functions at substantially the same relative key location in the open position of the second panel, as in the closed position.
DESCRIPTION OF THE DRAWING
[0010] The invention is described in more detail below with reference to the attached drawing in which:
[0011] [0011]FIG. 1 is a top view of the communications device of this invention in the closed position;
[0012] [0012]FIG. 2 is a top view of the communications device of this invention in the open position;
[0013] [0013]FIG. 3 a is a side view of the communications device of this invention in the closed position;
[0014] [0014]FIG. 3 b is a schematic illustration of the display orientation in the closed position;
[0015] [0015]FIG. 3 c is a schematic illustration of the display orientation in the open position;
[0016] [0016]FIG. 4 is a block diagram of the control system of a communication device as it applies to this invention;
[0017] [0017]FIG. 5 is a top view of an alternative embodiment of this invention;
[0018] [0018]FIG. 6 is a top view of embodiment of this invention showing an array of soft keys with the second panel closed; and
[0019] [0019]FIG. 7 is a top view of the embodiment of FIG. 6 with the second panel open.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0020] A mobile communication device is provided with a full function keyboard. For the purpose of illustration, this invention will be described with reference to a mobile telephone, but is applicable to other devices such as pagers, game units and the like. As shown in FIG. 3 a , a mobile telephone 1 is constructed having a body 2 . The body 2 encloses a screen 3 which provides a display 4 for communicating pertinent information to the user in response to actions by the user. The mobile telephone 1 is constructed having two panels 5 and 6 which are mounted on the body 2 . In FIG. 3, panel 5 is shown fixed to body 2 as a separated component, but it could also be constructed integrally with body 2 . Panel 6 is rotatable on the body 2 about an axis x-x as shown in FIGS. 1 and 2.
[0021] In a first position, referred to as the closed position, panel 6 is rotated into overlapping alignment with panel 5 , as shown in FIG. 3 a . Rotating panel 6 has two opposing flat faces 7 and 8 . Face 7 is the inner face when panel 6 is in the closed position and face 8 is the outer face in the closed position. In the preferred embodiment, face 8 contains a standard telephone keypad 9 for use when the mobile phone 1 is operating strictly in the communication mode. In the closed position, the device operates as a standard operating mobile telephone with the display 4 of screen 3 oriented in alignment with keypad 9 .
[0022] To provide the full function keyboard of the preferred embodiment of this invention, the key and button array 12 , used for the particular application, is divided in half and arranged on left and right keyboard portions 10 and 11 . To facilitate operation of the keyboard, it is designed for thumb actuation by both hands. This makes it convenient to hold the small device in both hands and operate the keyboard portions 10 and 11 accurately and efficiently.
[0023] As shown best in FIG. 3, the left hand keyboard portion 10 is constructed on face 7 of rotating panel 6 on the opposite side of telephone keypad 9 . The right hand keyboard portion 11 is constructed on upper face 13 of panel 5 . A back cover is assembled on the face 14 of panel 5 . To insure a compact engagement of panels 5 and 6 in the closed position, the portions of key array 12 on the opposing panel faces 7 and 13 are offset to avoid interference in the closed position.
[0024] To operate the keyboard array 12 , panel 6 is rotated approximately 180° to the open position to form a substantially flat unit having right and left keyboard portions separated by screen 3 as shown in FIG. 2. By holding the left and right hand portions in either hand, the keyboard, thus extended, can be conveniently operated using thumbs. In the open position, outer face 8 of panel 6 is oriented away from the user.
[0025] The display 4 of screen 3 is controlled for orientation in two positions depending on the mode of use. In the closed position, the display 4 is oriented in alignment with the keypad 9 , while in the open position the display 4 is aligned with the function key array 12 . As shown in FIGS. 3 b and 3 c , display orientation is rotated 90° between the mobile telephone mode in which panel 6 is in the closed position to the full function mode when panel 6 is in the open position. This is accomplished by providing a panel position indicator 15 which signals control unit 16 when the panel 6 is opened or closed. Control unit 16 may be a microprocessor, display driver or other means including hardware or software. This could be automatic or by a manual button operated by the user. The control unit 16 will signal the display control 17 to orient the position of the display as needed. In addition, in the open position, keypad 9 will be locked in an inoperative mode by telephone keypad lock 18 .
[0026] In the alternate embodiment shown in FIG. 5, instead of a keyboard, a game controller keypad is provided. The game keyboard consists of action buttons 19 and motion pad 20 constructed in panels 5 and 6 respectively. The telephone keypad 9 is constructed in the reverse side of panel 6 , as described above. As a further alternative, the device could be designed without a communication capability and used as a game unit only.
[0027] In this manner, a simple and compact keyboard is provided in operative association with a mobile communications device. It should be noted that other key arrays can be used such as the French AZERTY or the German QWERTZ (U). The device would also be useful as a microprocessor based game unit driven by game software or firmware.
[0028] In another embodiment of this invention, the panel position indicator 15 may be used to provide additional flexibility in the functioning of the device. Panel indicator 15 can be a series of contacts which are engaged in one of the positions of panel two or a switch which is closed or opened in one of the positions. Whatever scheme of actuation is used, panel indicator 15 sends a signal to the device control unit 16 which indicates the position of the moveable panel 6 .
[0029] As shown in FIGS. 6 and 7, soft keys 20 - 22 are constructed on body 2 at the periphery of the screen 3 . These soft keys are alternatively assigned to provide different functions depending on the position of the second panel 6 . The assignment of functions of the soft keys is controlled by device control unit 16 in response to signals from the panel position indicator 15 .
[0030] In a preferred embodiment of this invention, as shown in FIGS. 6 and 7, an array of soft keys 20 , 21 , and 22 is provided in which soft key 20 is at the upper left of the screen 3 , soft key 21 is at the lower left of screen 3 , and soft key 22 is at the lower right of screen 3 , when the panel 6 is in its closed position. In this position, which, as shown, is the position in which the device is used as a mobile phone, the use orientation is referred to as vertical. The functions that are assigned to the lower keys 21 and 22 are preferably for scrolling through profiles and menus to select specific sets of optional functions and services. A different set of key functions can be assigned to each of the lower keys. The power on/off function is assigned to upper key 20 . The user of the device therefore, becomes familiar with the location of the functions in this position of use.
[0031] In the open position, the device control 16 reassigns the functions of the soft keys to shift the set of functions of the lower keys clockwise or counter clockwise while the function of the upper left key is shifted to the upper right. In the device shown, the functions of the lower keys are shifted clockwise when moving panel 6 from closed to open position. This makes it easier for the user to become familiar with the location of certain functions and sets of key functions in either operational mode of the device.
[0032] In the open position (horizontal position), the array of keys is physically shifted clockwise and the upper soft key (key 20 in the vertical position) becomes key 22 at the upper right, while the lower soft keys (key 21 and 22 in the vertical position) are now keys 20 and 21 . Soft key 20 therefore is reassigned the functions of the lower left key and soft key 21 is reassigned the functions of the lower right key. The power on/off function is reassigned to key 22 .
[0033] The alternative functions in closed and open positions of panel 6 may be assigned in a wide variety of combinations and permutations depending on the applications served. The above examples generate considerable convenience in a dual mode device, but are not intended by any means to be exhaustive of the combinations that may be provided.
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A mobile communication device is provided with a body having a screen, a first panel fixed to the screen, and a second panel which mounted on said body for pivotable motion relative to said first panel. The second panel is either open or closed depending on the selected function of the device. A sensor generates a signal indicating the position of the second panel. Soft keys are provided which have alternative functions depending on the position of the second panel.
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BACKGROUND OF THE INVENTION
[0001] When congestion or rubbernecking occurs on major highways, vehicles stand still and idle their engines. As the congestion builds up, the wait time increases. The congestion wastes fuel and aggravates the driver's nerves.
[0002] Often it is the drivers own curiosity that helps to fuel the delay which is known as rubbernecking. As the name implies, rubbernecking refers to the action of passing drivers or motorists who divert their attention from the roadway in front of them to the unusual situation that is existing within eyeshot of the driver. This unusual situation can be a car accident, a hit pedestrian, road construction, road repair, a patrol car that pulled over a motorist, or some other disturbance. Because the driver is drawn to the disturbance, the driver must slow the car down to get a better view, and this leads to what is known as “rubbernecking.”
[0003] It is a desire of this invention to address several issues regarding rubbernecking; 1) find a way to decrease the wait time, 2) decrease waste of fuel, and 3) attempt to remove the need to rubberneck.
[0004] Here are some fuel expenditure conditions in the US, as illustrated in FIG. 9 . Almost 140 billion gals of fuel is used in the US. During a traffic jams, the study estimates, that in 75 of the largest metropolitan areas, almost 6 billion gals are wasted in traffic jams. Not to mention the time that is wasted waiting in a traffic jam.
[0005] A desirable feature of this invention would be to deter the need to perform rubbernecking. In addition, another feature of this invention would be to control the traffic flow while in a congested state to decrease the congestion.
BRIEF SUMMARY OF THE INVENTION
[0006] This invention relates to the idea of replacing the view of the accident with a second view that lacks detail. Ideally, this second view should be applied uniformly across a region of the country to substitute the disturbance with this commonly known second view. It is important to point out that this invention would decrease rubbernecking gradually since the need for rubbernecking should secede after a period of time because the reward of rubbernecking will not provide a visual of the unusual situation, instead the second view will be shown. Once this second view is accepted by all drivers in this region of the country, the drivers will tend to disregard the need to rubberneck.
[0007] The second view is a quickly erected shield that blocks the view of the disturbance from the passing drivers. This shield could have standardized appearance, but the net result will be that the driver would not be able to see disturbance. Features such as color, width and height of the shield or shields can be resolved to provide for better uniformity of the second view. As the uniformity improves, there will be a lesser chance for the driver or motorist to slow down.
[0008] One way of erecting the second view is by filling balloons with helium which in turn lifts shields to block the disturbance. The bottom end of the shield will have a counter weight to hold the base of the shield against the ground. In case of stiff cross winds, the ends of the shield can further be help in place by additional wires quickly connected to local support.
[0009] Another aspect of this invention is to control the flow of congested traffic in real time. Wirelessly controlled mobile flat units can be placed on the shoulder of the road and then moved onto the roadway remotely controlled by a master unit. As these flat units are moved onto the roadway, the congested traffic can run over these flat units without damaging them. Once these units are in position, a signal is given to raise or extend a reflective, illuminated post which also has an LCD (Liquid Crystal Display) display. This spacing of these marked posts defines and establishes a new dynamically adjusted roadway. As the traffic follows these roadways, the congestion becomes reduced until it is eliminated.
[0010] After the congestion is eliminated, the marked posts are slowly moved by the processor unit until the new sets of lanes superimpose the original set of lanes in the roadway. Then, the posts are lower or retracted and the units moved to the shoulder of the road for future reuse.
[0011] Another aspect of this invention is that the marked posts are positioned with the guidance of a master processor that has the details of the roadway in memory. The memory can be in the master processor or located on a web server. If the master processor knows; 1) which roadway is blocked, 2) the location of the accident, and 3) the positioning of the mobile flat units, the master processor issues instructions to the mobile units to optimize and reduce the flow of the congested traffic.
[0012] Once the shields are in place and the reward of rubbernecking is reduced, the traffic will become less affected by the rubbernecking event and the waste of fuel waiting in long traffic lines can be decreased. In addition, because of the active control of congested traffic, the ability to control and reduce congestion offers another approach to improving fuel usage in the US.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Please note that the drawings shown in this specification may not be drawn to scale and the relative dimensions of various elements in the diagrams are depicted schematically and not to scale.
[0014] FIG. 1 shows a typical major throughput highway.
[0015] FIG. 2 illustrates a traffic accident located in the shoulder of the road and the rubbernecking that starts to form.
[0016] FIG. 3 depicts a top view of the highway shown in FIG. 1 .
[0017] FIG. 4 a shows the inventive technique being applied to FIG. 2 to conceal the traffic accident from rubberneckers.
[0018] FIG. 4 b shows the inventive technique being applied to FIG. 2 a second way to conceal the traffic accident from rubberneckers.
[0019] FIG. 5 depicts the top view of the highway shown in FIG. 4 a illustrating the decrease in rubbernecking of this inventive technique.
[0020] FIG. 6 illustrates a traffic accident located directly in one of the lanes of the roadway and the rubbernecking that starts to form.
[0021] FIG. 7 shows the inventive technique being applied to FIG. 6 to conceal the traffic accident from rubberneckers.
[0022] FIG. 8 depicts the top view of the highway shown in FIG. 7 illustrating the decrease in rubbernecking of this inventive technique.
[0023] FIG. 9 shows a table illustrating the fuel usage in the US.
[0024] FIG. 10 shows the inventive technique being applied to FIG. 2 to control congestion building up in the roadway (note that the view is the southbound view of FIG. 2 ).
[0025] FIG. 11 a depicts the front view of a mobile flat unit that has the marked post extended.
[0026] FIG. 11 b shows the side view of a mobile flat unit that has the marked post extended.
[0027] FIG. 11 b illustrates the top view of a mobile flat unit that has the marked post extended.
[0028] FIG. 11 c depicts the top view of a mobile flat unit that has the marked post retracted.
[0029] FIG. 12 a illustrates the front view of a portion of a mobile flat unit illustrating the traction belt used to move the unit onto the roadway.
[0030] FIG. 12 b shows the side view of a portion of a mobile flat unit and some of the electronics inside the unit.
[0031] FIG. 13 depicts a tire of a vehicle rolling over the mobile flat unit.
[0032] FIG. 14 a illustrates the top view of the southbound lanes of FIG. 10 with the mobile flat units positioned in the shoulder of the roadway.
[0033] FIG. 14 b shows the top view of the southbound lanes of FIG. 10 with the mobile flat units being positioned.
[0034] FIG. 14 c illustrates the top view of the southbound lanes of FIG. 10 with the mobile flat units in position and posts extracted to control traffic flow dynamically.
DETAILED DESCRIPTION OF THE INVENTION
[0035] FIG. 1 illustrates a view of a typical highway or interstate 1 - 1 . The highway is bounded by 1 - 2 and 1 - 29 which defines the paved region of the highway. This highway 1 - 1 stretches from North to South as shown by the arrow. The highway has four paved lanes 1 - 16 , 1 - 18 , 1 - 23 and 1 - 28 heading North and has four paved lanes 1 - 3 , 1 - 5 , 1 - 9 and 1 - 14 heading South. The North and South directions are separated by the concrete barrier 1 - 15 . Each of the two outer lanes of the North and South directions serve as shoulders. The inner shoulders of the North and South directions are 1 - 16 and 1 - 14 , respectively. The outer shoulders the North and South directions are 1 - 28 and 1 - 3 , respectively. The active portion of the highway comprises lanes 1 - 18 and 1 - 23 traveling North and the lanes 1 - 5 and 1 - 9 traveling South.
[0036] The various lanes are separated by barriers, markings, depressions, or lines for demarcation purposes. For instance, the lanes that are traveling South 1 - 3 , 1 - 5 , 1 - 9 and 1 - 14 are bordered by markings 1 - 2 , 1 - 4 , 1 - 8 , 1 - 13 , and 1 - 15 , respectively and the lanes traveling North 1 - 16 , 1 - 18 , 1 - 23 and 1 - 28 are bordered by markings 1 - 15 , 1 - 17 , 1 - 22 , 1 - 27 and 1 - 29 , respectively. The markings 1 - 4 , 1 - 13 , 1 - 17 and 1 - 27 may have rumble strips formed in them to make the characteristic sound once the tires rolls over them. The barrier 1 - 15 separates the North from the South lanes as mentioned earlier. The dotted lines 1 - 8 and 1 - 22 separate the two active portions in each direction into two lanes.
[0037] The northbound traffic has moving vehicles 1 - 19 and 1 - 20 traveling at velocity 1 - 21 . While vehicles 1 - 25 and 1 - 26 are traveling at velocity 1 - 24 . In the southbound lanes vehicle 1 - 6 is traveling at velocity 1 - 7 while vehicles 1 - 10 and 1 - 11 are traveling at velocity 1 - 12 . Although it is not necessary for both vehicles in the same lane to travel at the same velocity at all times. Also note that a vehicle can be any moving vehicle such as a motorcycle, car, truck, van, scooter, tractor trailer, 18 wheeler or tandem rig.
[0038] The shoulders 1 - 3 , 1 - 14 , 1 - 16 and 1 - 28 are used to decelerate any vehicles traveling on the active portion of the highway for emergency care (typically when the car starts to fail in operation, a fender bender or minor collision) or unavoidable stoppage (police request) or for any other need to stop a vehicle.
[0039] FIG. 2 illustrates a view of a typical highway or interstate 2 - 1 after an accident 2 - 3 in the outer shoulder 1 - 3 between two vehicles 2 - 4 and 2 - 5 . Rubbernecking lines 2 - 6 and 2 - 7 start to build up in the Southbound lanes before the accident as those who are passing the accident want to slow down to get a better view. As these vehicles slow down, the following vehicles start forming rubbernecking lines 2 - 6 and 2 - 7 since the traffic before them has slowed down. The vehicles assume a bumper to bumper configuration. Likewise, in the northbound direction, rubbernecking lines 2 - 12 and 2 - 13 starts to form. All of these vehicles desire a view of the disturbance or accident so they slow down. The dotted region 2 - 2 is used and indicated in FIG. 3 .
[0040] Depending on the time of day, (for example, weekdays 8 AM or 5 PM) the rubbernecking traffic can build up quickly. FIG. 3 illustrates the bird's eye view 3 - 1 of FIG. 2 from above. Note that dotted region 2 - 2 . The accident is at 2 - 3 . The rubbernecking lines are illustrated in regions as 3 - 2 and 3 - 3 for the southbound and northbound lanes, respectively. The length of these rubbernecking lines could extend for several miles. Most cars in the rubbernecking lines are standing still or moving very slowing and are wasting fuel whether the fuel is gasoline, diesel, chemical reactions, or electric charge. In addition, besides the waste of fuel, each motorist is stretched to the edge of their patience of just waiting in the rubberneck or congested line. After the vehicles pass the accident, the traffic starts to move again as illustrated in regions 3 - 4 and 3 - 5 where the spacing between vehicles increases again.
[0041] FIG. 4 a illustrates the inventive technique of using shields to block the details of the accident 2 - 3 which is behind the shields 4 - 4 a through 4 - 4 n . The shields are connected to the balloons by wires 4 - 3 a through 4 - 3 n and are lifted by helium balloons 4 - 3 a through 4 - 3 n . Another possibility is for a shield that can be constructed so that it can hold helium eliminating the need for the wires and balloons. Ideally, the traffic would be flowing in the northern directions at velocities 4 - 6 and 4 - 7 and in the southern directions at velocities 4 - 4 and 4 - 5 . These velocities should be larger than the velocities given for FIG. 2 without the shields in place.
[0042] A bird's eye view of FIG. 4 a is given in FIG. 5 . Due to the shields 4 - 4 a through 4 - 4 n and the lack of information to rubberneckers, the motorists will not slow sown to view just a shield, although they may slow slightly to drive with caution. The “rubbernecking” lines indicated in the regions 5 - 3 and 5 - 4 have been improved in that not all cars are bumper to bumper and the traffic flow improves.
[0043] FIG. 4 b illustrates a second inventive technique of using shields to block the details of the accident 2 - 3 . The shields 4 - 4 a through 4 - 4 n are now placed juxtaposed to the barrier 1 - 15 . The shields are connected to the balloons by wires 4 - 3 a through 4 - 3 n and are lifted by helium balloons 4 - 3 a through 4 - 3 n.
[0044] Another possibility instead of balloons is to use light rigid shield extensions that fit over the barrier 1 - 15 to block the view of the northbound traffic. Although this solves half of the rubbernecking problem (only the northbound lane), the ability to position these shields could be performed very quickly.
[0045] FIG. 6 shows a portion 6 - 2 of a road 6 - 1 . An accident 6 - 3 between two vehicles 6 - 4 and 6 - 5 occurred in the outer southbound lane 1 - 5 . The traffic flow 6 - 8 of the vehicles 6 - 6 is stopped. While the flow 6 - 9 of the traffic 6 - 7 is reduced due to rubbernecking and the traffic of the vehicles 6 - 6 trying to enter the inner lane. In the northbound lanes, the traffic flow 6 - 10 of the vehicles 6 - 12 and the traffic flow 6 - 11 of the vehicles 6 - 13 are reduced due to rubbernecking.
[0046] FIG. 7 shows the inventive technique of using shields to block the details of the accident 6 - 3 which is behind the shields 7 - 4 a through 7 - 4 n and shields 7 - 5 a through 7 - 5 n . The shields are connected to the balloons by wires and are juxtaposed to the accident. New traffic patterns are established. The traffic flow 7 - 8 comprising vehicles 7 - 3 and 7 - 6 occur in the shoulder of the southbound lane. While the traffic flow 7 - 9 is formed by the vehicles 7 - 7 . The northbound traffic flows of 7 - 10 and 7 - 11 due to the vehicles is reduced.
[0047] A bird's eye view 8 - 1 of FIG. 7 is given in FIG. 8 . Due to the shields and the lack of information to rubberneckers, the vehicles begin forming new lanes before the accident in region 8 - 3 . And due to the shields, the northbound lanes do not suffer a backup in region 8 - 4 .
[0048] FIG. 9 provides a table illustrating the fuel usage in the US being almost 140 billion gals a year. Due to the traffic jams caused by rubbernecking and roadway congestion, almost 6 billion gals of fuel is wasted in the largest 75 metropolitan areas. According to the analysis of the 75 largest metropolitan areas by the Texas Transportation Institute in 2002, the average rush-hour driver wastes about 62 hours in traffic annually. The length of the average traffic jam has been increasing over the years. The Urban Mobility Report, from the Texas Transportation Institute, has indicated in 1982, traffic lasted for 4.5 hours a day in the 75 cities studied, however, in 2000, the traffic congestion time increased to seven hours a day.
[0049] FIG. 10 illustrates the use of extended mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n after being placed in position to control traffic congestion 10 - 1 . Note that this is the same scenario as shown in FIG. 2 but the view is from the southbound direction instead of the northbound direction. The flat units can be used in conjunction with the shields or each can be used alone to reduce traffic congestion. The traffic flows 10 - 4 and 10 - 5 in the southbound direction are controlled dynamically with the use of the mobile flat units.
[0050] FIG. 11 a shows an insert 11 - 2 presenting the front view of an extended mobile flat unit 10 - 2 . The extended post 11 - 4 can have LED's (Light Emitting Diodes) 11 - 5 and reflective paint (not shown). The top of the post 11 - 3 has a display panel. The display panel can be an illuminated LCD or LED panel that can be used to display instructions 11 - 8 . Some examples of instructions can include; 10 MPH, STOP, 5 MPH or any other instruction that can be directed to the motorists in the vehicles. The section 11 - 7 will be described later with regards to height, contents, durability, mobility, etc.
[0051] FIG. 11 b depicts an insert 11 - 10 presenting the side view 11 - 9 of an extended mobile flat unit 10 - 2 . The extended post 11 - 4 is viewed from the side.
[0052] FIG. 11 c illustrates an insert 11 - 12 presenting the top view 11 - 11 of an extended mobile flat unit 10 - 2 . The extended post 11 - 13 is viewed from the top and a cavity 11 - 14 is embedded in the unit 10 - 2 .
[0053] FIG. 11 d shows an insert 11 - 16 presenting the top view 11 - 15 of a retracted mobile flat unit 10 - 2 . Note that the post 11 - 17 is rotated into the recessed cavity 11 - 14 and prevents tires from damaging the retracted post when the tire rolls over the mobile unit 10 - 2 . A dotted rectangle 11 - 18 illustrates one of the rubber tracks that are located beneath the unit 10 - 2 .
[0054] FIG. 12 a depicts the front view 12 - 1 of a mobile flat unit 10 - 2 . The rubber track 11 - 18 mentioned earlier is wrapped around two cylindrical shafts 12 - 3 and 12 - 4 . As the shaft 12 - 4 rotates counterclockwise, the unit moves in the direction 12 - 7 . The arrow 12 - 5 presents the side view shown next.
[0055] FIG. 12 b illustrates the side view 12 - 5 of a mobile flat unit 10 - 2 . The rubber track 11 - 18 mentioned earlier as well as additional rubber tracks 12 - 2 and 12 - 8 are presented. The rubber tracks are shown in contact with the road 12 - 9 . A local processor 12 - 11 receives/transmits instructions from/to the wireless block 12 - 12 . The motor 12 - 10 controls the movement of the cylindrical shafts (not shown) which move the rubber tracks and thereby move the unit in/out of the page. Although not shown, the unit also contains all the components required to form the system. For example, batteries, memory, clocks that may be required but not shown.
[0056] FIG. 13 shows the off-angle view 13 - 1 of a vehicle's tire 13 - 2 rolling over the unit 10 - 2 that is on the road 12 - 9 . The height of the unit is minimized and the edges are tapered to allow easy entry and exit of the tire over the unit. The unit must be built to withstand the forces of the various masses that the tires of the vehicles transfer to them.
[0057] FIG. 14 a depicts a top view 14 - 1 of a master processor 14 - 2 controlling the mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n . The flat units can be positioned in the shoulder of the roadway. The control to move the units is performed wirelessly by the communications paths 14 - 3 , 14 - 4 , 4 - 5 and 14 - 6 . As an alternative, the mobile flat units can communicate using wired connections (not shown). This control moves the units in the direction of the arrows 14 - 7 into lane 1 - 5 . To simplify the drawings, the traffic of vehicles traveling over these lanes is not shown, but it is understood that the mobile flat units can be rolled over by the tires of vehicles without damaging the units. The master processor 14 - 2 contains all the components necessary to control the flat units, such as, wireless systems, computation systems, memory storage systems, and contact with a roadway database that described the features of the roadway. In the remaining figures of moving the mobile flat units into place, the master controller is not shown.
[0058] FIG. 14 b depicts a top view 14 - 8 of the mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n moved closer into final position. The units are still moving in the direction 14 - 9 and are now located in the two lanes of the southbound lanes 1 - 9 and 1 - 5 .
[0059] FIG. 14 c shows a top view 14 - 10 of the mobile flat units 10 - 2 a to 10 - 2 n and 10 - 3 a to 10 - 3 n moved when they are in final position. At this point, a command from the master controller is given to extend the post as illustrated in the inset 14 - 11 . The vehicles 14 - 13 now use the new lanes defined by the extended posts.
[0060] Once the traffic congestion is controlled, the mobile units are slowly moved under the master control in the opposite direction with active traffic flowing in the lanes. The movement occurs until the mobile flat units 10 - 2 a to 10 - 2 n are overlaying the center line 1 - 8 and the mobile flat units 10 - 3 a to 10 - 3 n are overlaying the edge line 1 - 4 . At this point, the posts are retracted and the vehicles follow the lines in painted lines in the road. Meanwhile, the mobile flat units are moved into the shoulder 1 - 3 for pickup and removal.
[0061] Finally, it is understood that the above description are only illustrative of the principles of the current invention. It is understood that the various embodiments of the invention, although different, are not mutually exclusive. In accordance with these principles, those skilled in the art may devise numerous modifications without departing from the spirit and scope of the invention. For example, in place of helium balloons used to lift the shield, hydrogen can be used. Rigid rods connected to a base can be used to hold the shield in place. The mobile base units can also communicate directly with the passing vehicles to provide instructions directly to the vehicle processor located in the vehicle. Both, the rubbernecking and congestion control can be used together or individually.
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One estimate indicates that rubbernecking and congestion consumes about 4% of this country's fuel. Two approaches are presented to help solve this problem. The first uses shields to block the view of a car accident. Rubbernecking is reduced since the visibility of the car accident is reduced. A second approach uses mobile flat units that can be remotely controlled to enter a roadway that is carrying active traffic. The traffic runs over these units that are being moved until the master processor indicates that the mobile flat units are in position. A post is extended from the flat unit that issues commands to the motorists so the master processor can begin to control and reduce congestion. Both approaches can be used to help decrease fuel waste in the US.
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BACKGROUND
The present invention relates to exhaust gas heat exchangers, as are known in general, and to a sealing device which is suitable particularly for use in the case of exhaust gas heat exchangers.
Exhaust gas heat exchangers are used in exhaust gas recirculation systems in particular for increasing the mass of combusted air taken in during an intake stroke. For this purpose, the density of the recirculating exhaust gas flow has to be increased, which takes place by means of cooling of the recirculated gas flow. This usually takes place by the exhaust gas flow flowing through an exhaust gas heat exchanger where it outputs heat to a coolant, such as a cooling liquid.
Exhaust gas heat exchangers are therefore known, through which both an exhaust gas flow and a coolant flow. The exhaust gas heat exchanger has for the exhaust gas flow connection points for connecting the heat exchanger, with, firstly, an exhaust gas supply line being provided for supplying the hot exhaust gas flow, and an exhaust gas withdrawal line being provided for withdrawing the exhaust gas flow cooled in the exhaust gas heat exchanger. In this case, the exhaust gas flow flows in a throughflow direction through the exhaust gas heat exchanger in a bundle of exhaust gas guiding tubes. The bundle of exhaust gas guiding tubes serves essentially to enlarge the exchange surface between the exhaust gas flow and the coolant flow. At least one coolant supply connection and at least one coolant withdrawal connection are provided for the throughflow of the coolant flow through the exhaust gas heat exchanger. The coolant is guided here in a coolant channel within which it flows around the bundle of exhaust gas guiding tubes.
SUMMARY
In the case of exhaust gas heat exchangers of this type, the coolant flow is either guided through the exhaust gas heat exchanger in parallel with and in the direction of the exhaust gas flow or else is guided through the exhaust gas heat exchanger counter to the throughflow direction of the exhaust gas flow.
The selection of the throughflow direction of the coolant flowing with respect to the exhaust gas flow is dependent here firstly on structural conditions, for example the option of permitting the linear compensation for the thermal expansion of the parts conducting exhaust gas through the exhaust gas heat exchanger and secondly in respect of optimizing the heat output of the exhaust gas flow in the heat exchanger. In this case, the optimization is undertaken to the effect that the exhaust gas flow is to output as large a quantity of heat as possible to the coolant.
Furthermore, vibration problems frequently also occur in the case of exhaust gas heat exchangers. The excitations to vibration that are initiated in the driving mode of a vehicle and during operation of the internal combustion engine are also transmitted to the exhaust gas heat exchanger and, for example via the exhaust gas flow, excitations to vibration are also transmitted directly to the parts conducting the exhaust gas flow. In this case, in particular the exhaust gas guiding tubes have a tendency to vibrate, since they generally span a free length which is as long as possible and can vibrate in this region. It is therefore the object of the invention to optimize the design of an exhaust gas heat exchanger to the effect that the disadvantages can be compensated for and, at the same time, the quantity of heat output can be optimized. This object is achieved according to the invention described herein.
A further technical problem which occurs in conjunction with exhaust gas heat exchangers is the fluidtight guiding of the exhaust-gas-conducting connection points out of the exhaust gas heat exchanger. Due to the changing thermal load, this guiding of them out has to be able to compensate for an expansion play of the exhaust-gas-conducting parts. On the other hand, it is necessary for the tightness to continue to be ensured in this region. A particularly favorable design of a sealing device of this type can be gathered from the further embodiments of the invention. In this case, a sealing device of this type can also be used in the case of other component leadthroughs, which are to be designed in a fluidtight manner, out of another component which is thermally more heavily or less heavily loaded.
An exhaust gas heat exchanger designed according to the invention has an exhaust gas flow and a coolant flow flowing through it. The exhaust gas heat exchanger has for the exhaust gas flow connection points for connecting the exhaust gas heat exchanger both to an exhaust gas supply line for supplying a hot exhaust gas flow and an exhaust gas withdrawal line for withdrawing the exhaust gas flow cooled in the exhaust gas heat exchanger. The exhaust gas flow here flows in a throughflow direction through the exhaust gas heat exchanger in a bundle of exhaust gas guiding tubes. Furthermore, a coolant flows in a coolant flow through the exhaust gas heat exchanger. For this purpose, at least one coolant supply connection and at least one coolant withdrawal connection are provided. In the exhaust gas heat exchanger, the coolant is guided in a coolant channel within which it flows around the bundle of exhaust gas guiding tubes. According to the invention, the coolant channel has at least two regions which differ in terms of the throughflow direction of the exhaust gas flow by diverging throughflow directions of the coolant.
By means of the division of the coolant channel into two regions through which the flow flows in different directions, the transmission of heat from the exhaust gas flow to the coolant flow can be improved by the fact that the difference in temperature between exhaust gas flow and coolant flow is increased by a section twice being available at which coolant having the starting temperature is supplied and this not being in contact with the exhaust gas flow over the entire length of the exhaust gas heat exchanger.
In this connection, according to an advantageous refinement of the invention, each of the regions is assigned at least one coolant channel segment, with a coolant channel segment being fluidically connected in each case to the coolant supply connection and to the coolant withdrawal connection. The division into coolant channel segments and its respective fluidic connection with coolant supply connection and coolant withdrawal connection permits a simple division of the coolant channel into subsections having a different throughflow direction.
According to an advantageous refinement, at least one region of the coolant channel has the flow flowing through it in the throughflow direction of the exhaust gas flow. A throughflow in the same direction of exhaust gas flow and coolant flow permits a relatively long contact time between the coolant flowing through and the exhaust gas flowing through. By this means, in particular if the difference in temperature between exhaust gas and coolant is very large, a very favorable transfer of energy from the exhaust gas flow to the coolant flow is made possible. According to a further advantageous refinement, there is at least one region in which the coolant flow flows through counter to the throughflow direction of the exhaust gas flow. By means of this measure, a difference in temperature which is as constant as possible between exhaust gas flow and coolant flow is maintained over the entire length of the region. This measure also serves to optimize the transfer of energy from the exhaust gas flow to the coolant flow. A direction of flow of the coolant flow transverse to the exhaust gas flow is also possible.
According to a preferred refinement of the invention, a region of the coolant channel which has the flow flowing through it counter to the throughflow direction of the exhaust gas flow is formed on the approach-flow side of the exhaust gas guiding tubes and preferably a region of the coolant channel which has the flow flowing through it in the throughflow direction of the exhaust gas flow is formed on the discharge-flow side of the exhaust gas guiding tubes.
According to an alternative refinement, it is provided that a region of the coolant channel which has the flow flowing through it counter to the throughflow direction of the exhaust gas flow is formed on the approach-flow side of the exhaust gas guiding tubes and preferably a region of the coolant channel which has the flow flowing through it in the throughflow direction of the exhaust gas flow is formed on the discharge-flow side of the exhaust gas guiding tubes.
A further refinement of the invention makes provision for the at least two regions to have a fixed length ratio. According to a first advantageous refinement, the length ratio is determined as a function of the thermal coefficient of expansion of the material used for producing the exhaust gas guiding tubes. The length ratio is preferably selected in such a manner that a fixed relationship is observed in the thermal linear expansion of the two regions, the fixed relationship residing in particular in a length ratio, which is constant irrespective of temperature, of preferably one. The effect achieved by this measure is that the two different regions through which the flow flows have a constant length ratio irrespective of the temperature of each other. This measure leads in particular to the thermal expansion behavior of the exhaust gas heat exchanger being favorably influenced.
Another advantageous refinement makes provision for the length ratio to be determined in such a manner that in each of the two regions a predetermined portion of the heat energy output overall by the exhaust gas flow is output. Provision may be made here in particular for a small portion of the quantity of heat output overall to be output, for example, to the region through which the exhaust gas flow first of all flows, with more than 70%, in particular between 80 and 95%, of the quantity of heat output overall being output, for example, in one of the two regions. According to such a refinement of the invention, an exhaust gas heat exchanger is therefore provided by a small quantity of heat being output in a first region, which is preferably kept short, while the main part of the quantity of heat is exchanged in a subsequent, long section. This measure makes it possible to distribute the exchange of energy to two regions, with each of the regions being optimized in its function. In particular, by means of a design of this type, an overall relatively large transfer of energy from the exhaust gas flow to the coolant can therefore be transferred in an advantageous manner.
According to an advantageous refinement of the invention, the exhaust gas guiding tubes are designed in such a manner that a turbulent exhaust gas flow is formed in their interior. The measure of providing a turbulent exhaust gas flow increases the residence time of the exhaust gas in the exhaust gas guiding tube and therefore optimizes the heat exchange within the exhaust gas heat exchanger.
An exhaust gas heat exchanger designed according to the invention, which may also involve a development of the abovementioned refinements, makes provision for the exhaust gas heat exchanger to have at least one tube body which is formed from a bundle of exhaust gas guiding tubes which are aligned parallel to one another. In this case, the ends of the exhaust gas guiding tubes are in each case fixed on a common tube plate. They rest here in each case in an opening in the respective tube plate and close this opening in a fluidtight manner. All of the openings in the tube plate are assigned in each case to one exhaust gas guiding tube. The construction of a tube body in this way can be produced in a simple manner. In addition, the tube body is fixed on account of this manner of construction and is less susceptible to vibrations.
According to an advantageous refinement, provision is made, in the case of at least one of the tube plates, for a bell-shaped exhaust gas collector to be arranged on that side of the tube body which faces away from the bundle of tubes, said collector having a connection point and being connected in a fluidtight manner to the tube plate. The bell-shaped exhaust gas collector constitutes a simple means of providing a transition between a connection point and the tube body, with a distribution of the exhaust gas flow to the individual exhaust gas guiding tubes of the tube body or a collection of the partial flows after they have flowed through the exhaust gas guiding tubes being made possible.
According to a further advantageous refinement, the exhaust gas heat exchanger has two tube bodies, with two tube plates of the tube bodies facing each other—in particular directly butting against each other, the exhaust gas guiding tubes preferably being aligned flush with one another—and with said tube plates being connected to each other toward the outside in a fluidtight manner. The division of the exhaust-gas conducting means into two tube bodies makes it possible to displace the vibration behavior of the exhaust gas guiding tubes in the exhaust gas heat exchanger in the direction of higher natural vibration frequencies. This advantageously results in the service life of the exhaust gas heat exchanger being increased. The natural vibration frequencies are displaced into a region in which there are fewer excitations to vibration. This resides in the shortening of the free length of the exhaust gas guiding tubes. As a result, both the vibration behavior and a possible development of noise by the exhaust gas heat exchanger are reduced.
According to a preferred refinement, provision is made here for a respective bell-shaped exhaust gas collector to be arranged at both free ends of two tube bodies connected to each other, said collectors in each case having a connection point and being connected to the bundle of tubes in a fluidtight manner. In this case, provision is made in particular for the coolant channel of the exhaust gas heat exchanger to extend over the length between the two bell-shaped exhaust gas collectors and optionally also to partially enclose them. A respective sealing device is formed in this case between the bell-shaped exhaust gas collectors and a coolant housing which bounds the coolant channel and radially surrounds the tube bodies. According to a further preferred advantageous refinement of the coolant guiding housing, the latter is composed of two half shells which are added together to form a housing which is closed to the outside. The half shells have, on the one hand, two connections which are formed on the end-side of the half shells. One of the half shells has a further connection point in particular in the region of a widening of the outside diameter of the half shells, the connection point serving for the supply and the withdrawal of coolants.
The coolant is in particular cooling water which has been branched off from the cooling circuit of the internal combustion engine and is subsequently supplied to said cooling circuit again. In this case, it is possible in particular for the cooling liquid then to be supplied to a further heat exchanger, in particular to the heat exchanger for producing a flow of warm air for a heating system of the vehicle. Instead of water, the coolant may also be another fluid, for example air which is flowing through. Although the use of air reduces the thermal capacity of the coolant in comparison to other coolants, for example water, the heated air produced in this case can be used directly at another location, for example for defrosting vehicle windows or the like. Of course, the coolant flow in this case may also be used directly for heating the interior of the vehicle.
According to a method according to the invention for producing an exhaust gas heat exchanger, first of all the tube bodies are produced. If required, the two tube bodies are connected to each other in a fluidtight manner. The bell-shaped exhaust gas collectors are subsequently fastened to the free ends of the tube bodies and in particular are connected to the tube plates in a fluidtight manner. The tube body, optionally further supported in the region of the exhaust gas guiding tubes by intermediate webs, is inserted into a lower half shell. The sealing devices are fastened to the bell-shaped exhaust gas collectors. They are connected to the lower half shell of the coolant guiding housing in a fluidtight manner. The upper half shell is then placed onto the lower half shell. A fluidtight connection is produced in the region of the sealing device and via the abutting edge of the two half shells against each other.
A particularly favorable method for producing two tube bodies, the exhaust gas guiding tubes of which are aligned flush with one another, resides in two tube plates which are arranged tightly next to each other being pushed on to a corresponding number of gas guiding tubes having, as seen continuously, the entire length of the pair of tube bodies. In this case, a connection may already be produced between the tube plates and the individual exhaust gas guiding tubes. The connection may be produced, for example, by shrinking on, by corresponding adhesive bonding or else by welding. Before or after the production of the connection between the individual exhaust gas guiding tubes and the tube body, a severing of the bundle of the exhaust gas guiding tubes takes place in a gap between the two tube plates. Before this severing takes place, the outer tube plates may also be pushed onto the bundle of exhaust gas guiding tubes. The severing takes place in particular by laser cutting or a comparable process. According to a preferred refinement, the severing may take place in each case flush with the surface of the two tube plates. If a further working step then has to be carried out in order to fasten the exhaust gas guiding tubes to the tube plates, then this is carried out now. The two tube plates can subsequently be connected to each other in a fluidtight manner, which can take place in particular by them being adhesively bonded or welded to each other along their abutting surfaces, with it being possible for the weld seam to follow the outer contour of the tube plates. However, it is also possible, via an encircling crimping or clamping, to produce an additional or sole fastening of the tube plates to each other. Following this, a respective tube plate may also be fastened to the free ends of the exhaust gas guiding tubes, if this has not yet happened. The bell-shaped gas collectors are welded onto the tube plates.
A sealing device designed according to the invention for an exhaust gas heat exchanger or another fluidtight leadthrough between two components, namely an exhaust-gas-conducting hot component and a cold component which outwardly bounds a cooling device, serves to lead the hot component through to the outside through the cold component. In this case, the hot component is held in the cold component in a manner such that it can be displaced longitudinally with axial guidance. According to the invention, the sealing device has two sealing elements which are independent of each other. Each of the sealing elements produces a fluidtight connection between hot component and cold component.
The provision of a double seal, with two sealing devices completely independent of each other, increases the service life and the security of the sealing device in particular in the case of applications exposed to high thermal loads. In this case, care has to be taken to ensure that the sealing device, on the one hand, is indeed arranged in the region of the component cooled by the cooling liquid, but, on the other hand, can be entirely exposed to the high temperatures of the hot component.
According to a preferred refinement of the invention, an intermediate chamber which is closed in a fluidtight manner is formed between the two sealing elements of the sealing device. This intermediate chamber permits the seals to be separated spatially from each other and at the same time to form an insulating gap between the two seals. Furthermore, the penetration of one of the two media, i.e. of the exhaust gas flow or of the coolant flow, into the intermediate chamber between the two sealing devices can constitute an indication of a corresponding leakage and can be monitored.
According to a preferred refinement of the invention, at least one bore passing through the cold component and leading to the outside is fitted into the sealing device in the region between the two sealing elements, the at least one bore having a thread in particular over a partial length. The provision of corresponding bores which may lead in particular into the intermediate chamber results in it being possible in a simple manner firstly to check the seal tightness of the sealing devices during production and secondly also to monitor the occurrence of leakages of the sealing devices. It is possible in particular to establish whether the first, inner sealing element of the sealing device still forms a sealing closure in relation to the seal situated between the hot component and the cold component. Medium can only penetrate from this chamber into the intermediate space between the two sealing elements if the inner seal is untight. This would be made noticeable by the escape of medium, for example a coolant, flowing through the chamber. This would escape in this case at the at least one bore and would be detectable there. According to a preferred refinement of the invention, the sealing device has more than one, in particular two or three such bores. The bores are suitable in particular for the connection of a burst-testing device for carrying out a tightness check. A method for carrying out a tightness check before a device having a sealing device designed in such a manner is used involves the bores being closed, in particular involves line endings being screwed into the bores. A pressurized fluid, for example compressed air, is then supplied via at least one of the lines. It is checked via a pressure measuring device connected to another bore whether the pressure provided can be maintained constantly in the intermediate space over a predetermined time without pressurized fluid being fed in. After appropriate venting, the burst-testing device can then be removed again. If a leakage occurs, then it can be checked, for example by measuring the pressure at the connection points of the chamber of an exhaust gas heat exchanger designed according to the invention, whether the leakage takes place into the chamber. This can be established with, for example, a rise in pressure in the chamber. It is therefore not only possible by means of the burst-testing process to establish leakages, but also to classify which of the two sealing elements is not fully sealing. The tightness of the coolant channels may also be checked by such a burst-testing process.
It is in keeping with advantageous refinements if at least one of the two sealing elements is a radial seal or if at least one of the two sealing elements is an axial seal. The terms radial seal and axial seal have been selected in such a manner that a radial seal refers to a seal in which the sealing means extends in the radial direction from one sealing surface to the other sealing surface and seals off an intermediate space. An axial seal extends along an axis and seals off a gap which is correspondingly aligned. Therefore, in the case of the radial seal, the throughflow direction of a leakage is aligned axially while this runs radially in the case of an axial seal. As radial seal, use can be made in particular of sealing rings of polymer compounds or with metal while the axial seal can be designed, for example, as a bellow seal, in which a bellows, which is folded in the manner of a concertina and forms a ring, is connected in a fluidtight manner by its axial ends in each case to one component of the components which are to be sealed off in relation to one another.
A tightness test during the use of the sealing device, for example during the operation of a vehicle, and the use of the sealing device in an exhaust gas heat exchanger takes place, for example, in such a manner that the escape of coolant as a bore is checked. Instead of a visual check, it is also possible, of course, for a sensory test to be carried out via a moisture sensor arranged there. For this purpose, it is in keeping with an advantageous refinement of the invention if the at least one bore is arranged in the region of the installation position at the lowest point of the sealing device.
It is in keeping with a particularly advantageous refinement if the sealing device has an axial seal and a radial seal, with the two seals being spaced apart from each other, so that an intermediate chamber is formed in particular between the two sealing elements. In this case, in particular the axial seal is the inner seal sealing off the two parts from each other during operation, while the radial seal is in particular the back up seal for the situation in which the axial seal has leakages.
The use of an axial seal in conjunction with a leadthrough in the case of a sealing device according to the invention has the advantage in particular that said axial seal is suitable for being able more easily to compensate for length plays between components movable with respect to one another, which length plays occur, for example, due to changes in temperature, than is the case in the case of a radial seal which has to be able to slide here along a sealing surface, so that an axial stroke of the two parts which are sealed off in relation to each other can be compensated for. The use of two different sealing elements also has the advantage that, in the case of loads which occur and over the load cycles, different strengths complement each other.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is furthermore explained in more detail below with reference to the exemplary embodiment which is illustrated in the drawings, in which:
FIG. 1 shows the sectional illustration through an exhaust gas heat exchanger according to the invention,
FIG. 2 shows the section with reference to the section line B-B through FIG. 1 in the region of the central connection;
FIG. 3 shows the section according to the section line A-A through FIG. 1 ; and
FIG. 4 shows the enlarged illustration of a detail of a sealing device according to the invention.
DETAILED DESCRIPTION
FIG. 1 shows, in a sectional illustration, an exhaust gas heat exchanger 10 designed according to the invention. In the illustration of FIG. 1 , the exhaust gas heat exchanger 10 has been divided into two parts 10 a and 10 b , with the division having taken place along the dividing line 10 c (illustrated by chain-dotted lines), so that the illustration of the heat exchanger, which is of linear design per se, can be undertaken on an enlarged scale without having to reproduce the proportions of the two tube bodies 23 in a changed manner. FIGS. 2 and 3 show sectional illustrations along the section lines A-A and B-B illustrated in FIG. 1 . FIG. 4 shows an enlarged illustration of a detail in the region of a sealing device, as also illustrated in FIG. 1 .
An exhaust gas heat exchanger 10 according to the invention, as illustrated in FIGS. 1 to 4 , is described below with reference to a method for producing an exhaust gas heat exchanger of this type.
First of all, a number of exhaust gas guiding tubes 21 , which may in particular be rectangular semi-finished products which can be cut to length, are aligned in a suitable number parallel to one another in accordance with the requirements of the invention. For this purpose, first of all the semi-finished products are cut to a length which corresponds approximately to the overall length of the section formed by the exhaust gas guiding tubes 21 in the exhaust gas heat exchanger. The two tube plates 24 , which are connected to each other at a later time, are then pushed, slightly spaced apart from each other, onto the exhaust gas guiding tubes 21 . In the process, these tube plates 24 are positioned on the exhaust gas guiding tubes 21 in such a manner that the two outwardly emerging, free lengths of the semi-finished product are in accordance with the desired ratio between the lengths of the exhaust gas guiding tubes of the two tube bodies 23 . The end-side tube plates 24 are also pushed onto the exhaust gas guiding tubes 21 . A respective exhaust gas guiding tube rests here in each opening in the tube plate that is intended for receiving an exhaust gas guiding tube. Like the two tube plates 24 pushed on first of all, the end-side tube plates can be connected to the exhaust gas guiding tubes 21 by being shrunk on. If desired or required, the end-side tube plates 24 may alternatively or additionally be welded to the exhaust gas guiding tubes 21 in order to produce a fluidtight connection to the same. A severing of the semi-finished products protruding through the central tube plates then takes place, with it being possible for this severing to be carried out, for example, by laser cutting. The severing takes place in each case flush with the surface of the mutually facing sides of the two tube plates 24 . Subsequently, if this is still required, the exhaust gas guiding tubes 21 are connected in a fluidtight manner to the two otherwise mutually facing tube plates 24 , for example by a corresponding welding process, with it also being possible for laser welding processes to be used here. In this manner, two tube bodies 23 which form a pair are formed in a simple manner from the semi-finished products.
The mutually facing, inner tube plates 24 are connected to one another in a fluidtight manner in the next working step, which takes place, for example, by them being welded together along their side edge, with care being taken to ensure the formation of a fluidtight, continuous welding seam. The welding can take place by laser welding or by roll spot welding or another welding process. In order to form a defined outer contour of the two tube plates, the latter can also be engaged around by an encircling ring clip 53 which is in particular also tightly welded onto it.
Respective bell-shaped exhaust gas collectors 25 are then welded in a fluidtight manner on the outer tube plates 24 , on the side facing away from the exhaust gas guiding tubes 21 . In this case too, an annular clip 54 can form the outer contour in the region of the attachment point between tube plate 24 and bell-shaped exhaust gas collector. Also, in particular welding processes with a weld seam running continuously are suitable as a fastening possibility for the fastening of the bell-shaped exhaust gas connectors.
The first of two tube bodies 23 , which are closed on both sides by bell-shaped exhaust gas collectors 25 , is then inserted into a lower half shell 44 . The lower half shell forms part of the coolant guiding housing 13 and in the region of its profile delimits the chamber 14 in the interior of the coolant guiding housing outward. In the process, the constructional unit is held in the region of the two tube plates 24 which are welded to each other, i.e. not on the edge side in the region of extent of the constructional unit. The lower half shell 44 has a radial widening 52 which extends axially on both sides of the two tube plates 24 . In the region of the radial widening 52 , a bearing ring 47 is formed, said bearing ring radially surrounding the ring clip 53 and this forming a fixed mount for the constructional unit. By means of the bearing of the ring clip 53 against the bearing ring 47 , the path of fluid is prevented in the axial direction by the chamber 14 . An annular chamber 48 is formed on both sides of the bearing ring 47 , only in the region of the radial widening 52 , said annular chamber opening at one point into a connection point 19 , here a coolant withdrawal connection 19 , which is fluidically connected to both sides which are separated from each other by the tube plates 24 . In the exemplary embodiment illustrated, the coolant withdrawal connection 19 , however, is arranged in the upper half shell 43 which is placed on later.
After the constructional unit is inserted into the lower half shell 44 , the sealing unit 30 is fitted. The sealing unit 30 contains a basic body which is of essentially rotationally symmetrical design. The basic body ends in an insert flange 60 which can be placed against a corresponding bearing flange 49 of the upper half shell 43 and the lower half shell 44 . The flanges 49 and 60 are connected to each other in a fluidtight manner by welding, for example. Offset radially inward, the basic body 34 has a bearing sleeve 61 which, as seen axially, projects into the region of the bell-shaped exhaust gas collector 25 . In this region, the bearing sleeve 61 is of cylindrical design, i.e. is of rotationally symmetrical design with a constant diameter, as seen in the axial direction. Before the basic body 34 is placed on, an intermediate ring 62 is welded onto the bell-shaped exhaust gas collector 25 and surrounds the outer connectors of the bell-shaped exhaust gas collector radially in a fluidtight manner. The bellows seal 33 is pushed onto this intermediate ring 62 axially, said bellows seal having as fastening points a respective annular body 63 at its axial ends, between which the bellows of the bellows seal 33 extends and onto which said bellows is fastened in each case in a fluidtight manner. One of the two annular bodies 63 is welded in a fluidtight manner to the intermediate ring 62 . The other annular body 63 has an outer ring 64 which can accommodate drill holes which are preferably designed as a blind hole. In this case, the outside diameter of the outer ring 64 corresponds approximately to the outside diameter of the intermediate ring 62 , but is spaced apart axially from the latter, this axial spacing forming the intermediate chamber 35 . A pair of O-rings is arranged radially on the outside of the intermediate ring 62 , as a radial seal 32 on the circumferential surface. After intermediate ring 62 and axial seal 33 are fastened to the bell-shaped exhaust gas collector 25 , the basic body 34 is pushed in the axial direction over the bell-shaped exhaust gas collectors 25 in such a manner that the radial seal 32 of the intermediate ring 62 passes into sealing contact with the inner cylindrical surface of the bearing sleeve 61 .
Situated further on the outside in the axial direction, the outer ring 64 of the axial seal 33 is radially surrounded by the bearing sleeve 61 , with it being possible for the outer contours to have a conical design matched to one another, said conical designs tapering axially outward. The bearing sleeve 61 merges into a sleeve surface 65 which has bores positioned corresponding to the bores in the outer ring 64 and via which a screw fastening with fastening screws 66 can take place, with a fluidtight end being achieved via the in particular form-fitting bearing of the outer ring 64 against the sleeve surface 65 in the cylindrical to conical inner surface of the bearing sleeve 61 . In this case, the sleeve surface 65 opens up an opening into which a connecting flange 67 is inserted, said connecting flange being designed as a sleeve and the free inside diameter of which, through which the flow can flow, corresponds to the diameter of the bell-shaped exhaust gas collector in its inflow region. That inner region of the bell-shaped exhaust gas collector through which the exhaust gas flows is separated from the chamber 14 in the interior of the coolant guiding housing 13 via the axial seal 33 and the radial seal 32 . Owing to the fact that the axial seal 33 has axial movability in the axial direction via the convolution of its bellows and the intermediate ring 62 can slide in the axial direction in the bearing housing 61 , an axial compensation of the thermal expansion of the two tube bodies 23 is possible. The leadthrough of the exhaust gas supply line 16 or of the exhaust gas withdrawal line 17 through the exhaust gas heat exchanger is therefore a loose bearing, as seen in the axial direction. Only in the region of the bearing ring 47 is a positionally fixed mounting of the tube bodies 23 and therefore of all of the hot components out of the cold components provided.
In this case, the hot component 40 is the bell-shaped exhaust gas collector 25 and the connecting flange 67 forming a connection point 15 . The cold component 41 is formed by the upper and lower half shells 43 , 44 and by the basic body 34 of the sealing device 30 .
Bores 36 are guided through the basic body 34 into the intermediate chamber 35 which is bounded in the axial direction by the intermediate ring 62 and the annular body 63 or the ring 64 and radially by the axial seal 33 and the bearing sleeve 61 . If the radial seal 32 , which is formed here from two O-rings independent of each other, has a leakage, then liquid flows out of the chamber 14 into the intermediate chamber 35 due to this leakage. In the interior of the intermediate chamber 35 , this liquid then flows to the lowest point by a bore 36 being provided in each case. The escape of liquid from this bore enables the presence of a leakage to be established, but an overflow of the escaping cooling liquid, for example cooling water, into the part conducting exhaust gas is not possible owing to the presence of the axial seal 33 .
The connection points for the coolant supply connection 18 are also formed in the lower half shell 44 . These connection points are formed in a region of the lower half shell 44 by the latter also surrounding part of the bell-shaped exhaust gas collector 25 , so that the chamber 14 formed in the interior of the coolant guiding housing 13 which forms is situated and is therefore in contact with the influence of the coolant.
In the next working step, the upper half shell 43 is placed onto the lower half shell 44 and the half shells are welded and screwed to each other in a fluidtight manner. In this case, the upper half shell also has a bearing flange 49 . The basic body 34 is connected to the sealing device 30 in a fluidtight manner, i.e. in particular is welded thereto. It is also possible to provide screw bores in the direction of extent of the tube bodies 23 , by means of which the two half shells can be connected to each other, with it also being possible to provide a seal in order to obtain a fluidtight casing. It is possible to hold the bearing flange 60 in a fluidtight manner on the bearing flange 49 by a screw connection, with it also being possible for sealing means, such as O-rings, to be used here as sealing means.
The exhaust gas heat exchanger 10 illustrated in FIG. 1 has an exhaust gas flow flowing through it, illustrated diagrammatically by the arrows 11 . The exhaust gas supply line 16 supplies the exhaust gas flow which then flows into a bell-shaped exhaust gas collector 25 which acts as a diffuser and distributes the exhaust gas flow to the individual exhaust gas guiding tubes 21 of the tube bodies 23 . After flowing through the tube bodies, the exhaust gas flow 11 is collected in the second bell-shaped exhaust gas collector 25 and leaves the exhaust gas heat exchanger 10 in the exhaust withdrawal line 17 .
The exhaust gas heat exchanger has a cooling liquid, such as water, flowing through it as coolant. The coolant flow is illustrated by the arrows 12 . Two coolant flows form in the exhaust gas heat exchanger. The coolant is supplied through the two coolant supply connections 18 formed in the region of the bell-shaped exhaust gas collectors 25 . It flows in each case from the coolant supply connection 18 to the coolant withdrawal connection 19 formed in the region in which the two bundles of tubes 25 meet. From the coolant supply connection 18 , which is formed on the supply side of the exhaust gas flow, i.e. in the region of the exhaust gas supply line 16 , the coolant flows parallel to the exhaust gas flow flowing through the exhaust gas guiding tubes 21 , to the coolant withdrawal connection 19 . This is the shorter region in the embodiment illustrated, the length of which is approximately half the size of the longer of the two regions. In this case, the coolant flow is guided in the chamber 14 , which is bounded by the coolant guiding housing 13 , and flows around the exhaust gas guiding tubes 21 on all sides, so that a good flow of heat from the exhaust gas flow to the coolant flow is ensured. The coolant flow, which flows through the exhaust gas heat exchanger in the opposite direction to the direction of flow through the tube bodies 23 , flows from the coolant supply connection 18 —which is formed in the region of the bell-shaped exhaust gas collector 25 opening into the exhaust gas withdrawal line—to the annular chamber 48 and likewise passes into the coolant withdrawal connection 19 where it leaves the exhaust gas heat exchanger 10 .
During the flow through the exhaust gas heat exchanger, the exhaust gas flowing through is cooled while the coolant is heated. The exchange of thermal energy is facilitated by a surface area which is as large as possible and in which a contact between a separating surface, which has as thin a wall as possible, the exhaust gas flow is thermally conductively in contact with the coolant flow.
In this case, a process according to the invention, for cooling an exhaust gas flow, is complied with if the direction in which the coolant flows past the exhaust gas flow is divided into two regions, with the exhaust gas flow being oriented initially parallel to the exhaust gas flow in one region, for example the hotter of the two regions, while, in a second region, the coolant flow is directly counter to the throughflow direction of the exhaust gas flow. The two regions can be selected in an advantageous manner such that the thermal linear expansion of the exhaust gas guiding tubes corresponds to one another in these two regions. This makes it necessary for the first region to be of shorter design because a more rapid cooling is formed in this region than in the other region, with the effect ultimately being achieved by the different overall length that the difference in temperature of the two regions essentially corresponds to each other.
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An exhaust gas heat exchanger comprises connection points for the exhaust gas flow, for connecting the exhaust gas heat exchanger to an exhaust gas supply line for supplying a hot exhaust gas and an exhaust gas withdrawal line for withdrawing the exhaust gas flow cooled in the exhaust gas heat exchanger. The exhaust gas flow flows through the exhaust gas heat exchanger in a bundle of exhaust gas guiding pipes in a flow direction. The exhaust gas heat exchanger is provided with at least one coolant supply connection and at least one coolant withdrawal connection. Coolant is guided in a coolant channel in the exhaust gas heat exchanger, inside which it flows around the bundle of exhaust gas guiding pipes. The coolant channel comprises at least two regions which differ in terms of the flow direction of the exhaust gas flow by divergent flow directions of the coolant.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to monitoring and tracking systems, and more specifically to a product operations tracking system and method for oil and gas tubulars and tools.
[0003] 2. Background of the Invention
[0004] In the oil and gas industry, tools and products are regularly shipped from a vendor or owner to a customer. Generally, these tools are used during the drilling operations. Additional tools are often ordered on a standby basis for scenarios in which the operational tool fails and a substitute is needed.
[0005] Without oversight and control, it is difficult to monitor how often the tools have been utilized while in the control of the customer. The tool could be utilized for several hours, days, or even months, with the owner or vendor dependent upon receiving the utilization timeframes from the client. In some cases, tools shipped back to owners in a visibly operated state, showing wear and tear and the presence of drilling fluid, are reported as having never been used. In another scenario, tools involved in inter-company asset transfers can be lost or misplaced in inventory, or be loaned out to third-parties without being reported to someone in operations to track the asset. The financial loss incurred when improperly billing for standby costs rather than operating costs can represent a huge sum for companies.
[0006] The following patents discuss background art related to the above discussed subject matter:
[0007] U.S. Pat. No. 5,360,967, issued Nov. 1, 1994, to Perkin, et al., discloses an apparatus for identifying equipment, including the maintenance of usage histories for the equipment and recommending whether the equipment is to be used in a prospective application based on prospective application and usage history. A portable encapsulated passive circuit capable of transmitting an identification code is affixed to a piece of equipment. The circuit is activated by a portable reader which receives and decodes the identification code and transmits it to a central computer. The central computer verifies the reader and the existence of the equipment in a database and retrieves the usage history for the equipment. Based on the usage history, the prospective application and guidelines for usage of equipment, the computer determines the advisability of using the equipment in the prospective application and transmits the recommendation back to the portable reader.
[0008] U.S. Pat. No. 6,973,416, issued Dec. 6, 2005, to Denny, et al., discloses an oilfield equipment identifying apparatus comprising a computer loaded with an oilfield equipment database. A unique identification code is input into the computer for each piece of oilfield equipment in the drill string to form a reference in the oilfield equipment database to each piece of oilfield equipment in the drill string. A drilling monitoring device receives input signals indicative of at least one of rotating and non-rotating usage of the drill string and output signals to the computer wherein the computer continuously and automatically monitors the cumulative rotating usage and non-rotating usage of each piece of oilfield equipment identified in the drill string.
[0009] U.S. Pat. No. 7,014,100, issued Mar. 21, 2006, to Zierolf, discloses an assembly and process for identifying and tracking assets, particularly tubulars, equipment, tools and/or devices. An antenna is electrically connected to a responding device, such as a radio frequency identification device, and this assembly is connected to an asset. The antenna may be positioned about the exterior and/or the interior of the asset and significantly increases the range of signals that may be received and/or broadcast by the responding device. A transceiver may accordingly be positioned a greater distance from the asset without regard to the orientation of the asset and still permit communication between the transceiver and the responding device. In this manner, information that specifically identifies the asset may be compiled in a data base so as to maintain an accurate history of the usage of such assets as tubulars, equipment, tool and/or devices.
[0010] U.S. Pat. No. 7,159,654, issued Jan. 9, 2007, to Ellison, et al., discloses apparatus identification systems and methods. A member having a body, the body having two spaced-apart ends, wave energizable identification apparatus which, in one aspect, is radio frequency identification apparatus with integrated circuit apparatus and antenna apparatus on the exterior of the body, and encasement structure encasing the identification apparatus, the encasement structure, in certain aspects, including one or a plurality of layers of heat resistant material and, in certain aspects, at least one layer of heat resistant material, and methods for producing such a member.
[0011] U.S. Pat. No. 7,474,218, issued Jan. 6, 2009, to Johnson, et al., discloses a system and method for managing enterprise assets located at geographically distributed sites utilizing wireless tag technologies. The method includes storing in a database information relating to each asset, wherein the stored information includes cost of each asset and cost of service for each asset. The method further includes tracking and storing information relating to servicing of the assets, including the cost of servicing. Information relating to the assets is then displayed to a user of the system.
[0012] U.S. Pat. No. 7,603,296, issued Oct. 13, 2009, to Whiteley, et al., discloses a method for monitoring well equipment during transport and storage. Items of equipment and assemblies for use in drilling or completion of a well or in other well operations are monitored from the time they are assembled for shipment to a particular well site for a job through the time of delivery and installation at the well site. Radio frequency identifier devices (RFID's) are mounted with the items to electronically tag them as they are assembled for shipment. The items are assembled into containers which can be readily inventoried during transit to detect loss or pilferage. Detailed information about the individual items can be encoded into the RFID at the time of electronic tagging. If desired, the shipping containers can be provided with separate RFID's detailing the particular items within the container and the progress of the shipment monitored remotely by satellite or the like.
[0013] U.S. Pat. No. 7,677,439, issued Mar. 16, 2010, to Zierolf, discloses an assembly and process for identifying and tracking assets, such as tubulars, equipment, tools and/or devices. An antenna is electrically connected to a responding device, such as a radio frequency identification device, and this assembly is connected to an asset. The antenna may be positioned about the exterior and/or the interior of the asset and significantly increases the range of signals that may be received and/or broadcast by the responding device. A transceiver may accordingly be positioned a greater distance from the asset without regard to the orientation of the asset and still permit communication between the transceiver and the responding device.
[0014] U.S. Pat. No. 7,912,678, issued Mar. 22, 2011, to Denny, et al., discloses a system for identifying a piece of oilfield equipment having an exterior surface, the system having an identifier assembly that includes an RFID tag storing a unique identifier, an enclosure receiving and retaining the RFID tag, and a reader.
[0015] U.S. Pat. No. 7,946,356, issued May 24, 2011, to Koederitz, et al., discloses a n item (e.g. a drill bit) handling method, the item for use in a well operation, the method including producing information about an item used for a specific well task, the information including design information and intended use information, producing an item identification specific to the item, associating the information with the item identification producing thereby an information package, installing the information package in at least one wave-energizable apparatus, and applying the at least one wave-energizable apparatus to the item.
[0016] U.S. Pat. No. 8,091,775, issued Jan. 10, 2012, to Zierolf, discloses an assembly and process for identifying and tracking assets, such as tubulars, equipment, tools and/or devices. An antenna is electrically connected to a responding device, such as a radio frequency identification device, and this assembly is connected to an asset. The antenna may be positioned about the exterior and/or the interior of the asset and significantly increases the range of signals that may be received and/or broadcast by the responding device. A transceiver may accordingly be positioned a greater distance from the asset without regard to the orientation of the asset and still permit communication between the transceiver and the responding device. In this manner, information that specifically identifies the asset may be compiled in a data base so as to maintain history of the usage of such assets as tubulars, equipment, tool and/or devices.
[0017] U.S. Pat. No. 8,463,664, issued Jun. 11, 2013, to Griggs, et al., discloses serialization and database methods for tubular and oilfield equipment. Methods and apparatus identify downhole equipment and correlate input data with the equipment to improve planning and/or inventory operations. For some embodiments, oilfield equipment or tubular goods such as drill pipe include a shaped recess along an outer circumference for receiving a tag cartridge by shrink fitting. Once tagged, detector system configurations at pipe yards may facilitate logging the presence and location of each drill pipe and correlating specific data, such as inspection data, to each drill pipe. Further, this correlation populates a database utilized to achieve other business functions such as forecasting number of additional drill pipe needed to purchase, invoicing customers according to actual tracked wear/use of the drill pipe being returned, and providing well or job specific drill string population using known history pipe joints.
[0018] U.S. Patent Application No. 2013/0063277, published Mar. 14, 2013, to
[0019] Christiansen, discloses a system and method for managing use of a downhole asset. In one embodiment, a system includes a rig interface, a tag reader, and FIG. 1 a remote datacenter. The rig interface is disposed proximate to a borehole being drilled, and configured to process information related to use and physical condition of the downhole asset while drilling the borehole. The tag reader is configured to transfer a measurement of an attribute of the downhole asset to the rig interface. The remote datacenter is disposed remote from the borehole and is configured to assess the condition of the downhole asset based on information received from the rig interface and additional information related to use of the downhole asset received by the remote datacenter over the life of the downhole asset.
[0020] The above prior art does not provide a suitable solution to the above and/or other problems. There exists a need for an improved product operations tracking system. Consequently, those skilled in the art will appreciate the present invention that addresses the above and/or other problems.
SUMMARY OF THE INVENTION
[0021] An object of the present invention is to provide an improved product operations tracking system.
[0022] Another object of the present invention is to provide an improved product operations tracking system which more accurately tracks the utilization time for the product being monitored.
[0023] Yet another object of the present invention is to provide a product operations tracking system which can track a physical location of a product and verify correct product is being monitored.
[0024] These and other objects, features, and advantages of the present invention will become clear from the figures and description given hereinafter. It is understood that the objects listed above are not all inclusive and are only intended to aid in understanding the present invention, not to limit the bounds of the present invention in any way.
[0025] In accordance with the present disclosure, one possible embodiment of a product operations tracking system may include, but is not limited to, a thread protector connectable with the threaded member of a tool, a switch mounted to the thread protector and being configured to detect removal and replacement of the thread protector from the tool, a timer operably connected to the switch to track a utilization time, and a power source operably connected to the switch and the timer.
[0026] More generally the present invention utilizes an end protector, which may comprise a thread protector, end cap, sleeve, plug or the like.
[0027] The timer and the switch may be configured so that when the end protector/thread protector is removed from the tool, the timer initiates counting the utilization time.
[0028] The system may comprise an identifier tag on the tool, wherein the identifier tag comprises at least one of a barcode, a QR code, and/or a serial number.
[0029] The system may further comprise a camera mounted to the end protector/thread protector and positioned to observe and take a picture of the identifier tag. In another embodiment, a GPS antenna for determining a location of the tool may be included with the product operations tracking system.
[0030] In one embodiment, the timer may further comprise software and a processor. In another embodiment, the tool may comprise an oil and gas tubular.
[0031] The system may further comprise at least one of a database or memory to store at least one of the utilization time, the location, and the picture of the identifier tag. The switch may include at least one of a mechanical switch, a light based switch, or a digital switch.
[0032] In another embodiment of the present invention, a method for a product operations tracking system for use with a tool comprising an end to be protected during non-use with an end protector being removed during use of the tool. The method may comprise steps such as providing an end protector connectable with an end of the tool, mounting a switch to the end protector configured to detect removal of the end protector from the tool, operably connecting a timer to the switch to track a utilization time, and operably connecting a power source to the switch and the timer.
[0033] The method may further comprise providing the timer and switch are configured so that when the end protector is removed from the tool, the timer initiates counting the utilization time. Another step may comprise providing an identifier tag on the tool, wherein the identifier tag comprises at least one of a barcode, a QR code, and/or a serial number.
[0034] The method may comprise further steps, such as mounting a camera to the end protector positioned to observe and take a picture of the identifier tag, and providing a GPS antenna for determining a location of the tool.
[0035] Other steps may include providing the timer further comprises software and a processor, providing the tool comprises an oil and gas tubular, providing at least one of a database or memory to store at least one of the utilization time, the location, and the picture of the identifier tag, and providing the switch is at least one of a mechanical switch, a light based switch, or a digital switch.
[0036] In yet another embodiment of the present invention, a system for tracking usage of an oilfield tubular is presented, comprising, but not limited to, a removable member mountable to the oilfield tubular, and a timer built into the removable member to detect use of the oilfield tubular, whereupon the removable member is removable from the oilfield tubular for access to the electronic usage detection system to determine the usage of the equipment.
[0037] The system may further comprise a timer built into the removable member.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] The above general description and the following detailed description are merely illustrative of the generic invention, and additional modes, advantages, and particulars of this invention will be readily suggested to those skilled in the art without departing from the spirit and scope of the invention. A more complete understanding of the invention and many of the attendant advantages thereto will be readily appreciated by reference to the following detailed description when considered in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts and wherein:
[0039] FIG. 1 is an elevational view, in section, of a product operations tracking system in accord with one possible embodiment of the present invention.
[0040] FIG. 2 is a perspective view of a product operations tracking system with thread protector type of end protector removed from tool in accord with one possible embodiment of the present invention.
[0041] FIG. 3 is a block diagram of a product operations tracking system in accord with one possible embodiment of the present invention.
[0042] FIG. 4 is block diagram of another embodiment of a product operations tracking system in accord with one possible embodiment of the present invention.
[0043] FIG. 5 is a flowchart of the life cycle for a product operations tracking system in accord with one possible embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0044] Detailed descriptions of the preferred embodiment are provided herein. It is to be understood, however, that the present invention may be embodied in various forms. Therefore, specific details disclosed herein are not to be interpreted as limiting, but rather as a basis for the claims and as a representative basis for teaching one skilled in the art to employ the present invention in virtually any appropriately detailed system, structure or manner.
[0045] In a preferred embodiment, product operations tracking system is designed to track when a product is being utilized. A product will have a connection with the tracking device and allow for operational tracking of the product once the tracking device is removed. In a preferred embodiment, the system is designed so that the tracking device is removed in order to operate the product. The customer by contract will be aware that once the tracking device is removed, billing will be at an operational rate and not a standby rate. The system will show that the tool was utilized and provide an estimated time in operations. When operations of the product are completed or there is a need to stop the time of use, the customer will reconnect the tracking device to the product or tool.
[0046] While the preferred embodiment of the present invention relates generally to the oil and gas industry, the application of this system could be used to track products used in other industries, such as, but not limited to, aerospace, transportation, retail, and the like.
[0047] Turning now to FIG. 1 , there is shown an elevational view in section of product operations tracking system 100 . In this embodiment, thread protector 60 is fully connected with tool 50 . Thread protectors, end caps, sleeves, plugs, and the like are commonly used to preserve the integrity of the threadable portion, exterior surface, components of oilfield tools, tubular, equipment, machinery, and the like. While the present invention is described in terms of thread protector 60 , it will be appreciated that the present invention could be utilized with any type of end protector that includes thread protectors, end caps, sleeves, plugs, and the like. Therefore, as used herein, the term end protector will be used interchangeably and will be understood to encompass thread protectors, end caps, sleeves, plugs, and the like. End protectors are generally used with oilfield tubulars to protect the ends that may comprise threads, finish, interior components or the like, when the tool is not in use. In some cases, end protectors may not utilize threads and may instead may be press fit onto the end of the oilfield tubular. End protectors are normally required to be removed prior to operation of the tool. Once the tool is no longer being used, then the end protectors are replaced to protect the ends of the tool.
[0048] End protector/Thread protector 60 comprises tracking components to be described hereinafter to monitor product or tool 50 . End protector/thread protector 60 may be clearly marked for this purpose and may have an unusual shape so as to identify itself for this purpose. The contract for use of the tool may specify that thread protector 60 is utilized. In this disclosure, tool 50 may also be referred to as machine, equipment, tubular, product and the like, consistent within the teachings of this disclosure. End protector/Thread protector 60 is of a generic variety and could comprise any conceivable shape, provided it comprises threadable portion 62 which engage with threadable portion 52 of tool 50 to provide thread protection. In a preferred embodiment, end protector/thread protector 60 comprises a rubber material, PFTE material, polymeric material, non-metallic materials, or the like, but could conceivably be made with any material suitable including plastic, metal, and the like for attaching with tool 50 without harming threadable portion 52 , or other portions.
[0049] In this embodiment, switch 10 is positioned on inner shoulder 12 of end protector/thread protector 60 to activate and deactivate the various tracking components of product operations tracking system 100 . Battery 40 powers the tracking components, including detector/camera 20 , GPS 30 , and processor or timer 70 . Switch 10 is positioned to engage tool wall end 14 when thread protector end 44 contacts tool shoulder 42 . In other embodiments, switch 10 may be included in other portions of end protector/thread protector 60 , provided that switch 10 is positioned to be operable to detect when end protector/thread protector 60 is removed from and reconnected to tool 50 . Switch 10 is operably connected to processor 70 which is connected with camera 20 and GPS 30 . In a preferred embodiment, switch 10 is a mechanical switch. However, the invention is not limited to a mechanical switch and may comprise any type of electronic switch including motion detector or the like whereupon proximity to the tool, relative motion or rotating motion with respect to the tool acts to turn on power to a processor or timer. Processor 70 may comprise a programmed timer or may be a dedicated timer circuit as discussed hereinafter. If desired, a processor 70 could be utilized with a separate timer 72 . If desired, a solar cell may be built into battery 40 for charging the battery.
[0050] Detector/camera 20 is used to verify asset utilization and/or tracking information by taking pictures of identification code or marking 56 to ensure thread protector 60 is connected and/or removed from the same tool 50 . Detector/camera 20 may comprise cameras or any other suitable means to verify the use of the same tool 50 such as an RFID, bar code, RFID reader or bar code reader. Other types of devices and codes for verifying the same tool may be utilized for this purpose. Accordingly, detector/camera 20 as used herein broadly refers to any means of verifying that the same tool is being utilized with system 100 . This prevents end protector/thread protector 60 from being connected to a different piece of equipment, to stop the tracking of utilization time for tool 50 . GPS 30 is embedded within thread protector 60 to provide a location for tool 50 and to further verify status of tool 50 . In this preferred embodiment, GPS 30 also comprises antenna 32 for transmitting information and allowing interrogation of product operations tracking system 100 . In alternative embodiments, GPS 30 may have an integrated antenna and antenna 32 may be omitted. If desired, GPS 30 and antenna 32 may also comprise cellular telephone circuitry and antenna for broadcasting the information. However, in a preferred embodiment, non-volatile memory is utilized to keep a record of tool usage, whereupon the memory is read upon return of the tool.
[0051] FIG. 2 shows another perspective view of product operations tracking system 200 with end protector/thread protector 60 fully removed from tool 50 . Product Operations Tracking system 200 has detector/camera 20 positioned to verify operations utilization and/or tracking information by taking pictures of ID bar code, QC code, RFID, or markings 56 to prevent thread protector 60 from being connected to a different piece of equipment. As discussed hereinbefore, barcode or any type of identifying marking or identifier 56 could be located on inner wall 58 of tool 50 or at any desired location as shown in FIG. 1 . Processor/timer 70 can be activated when thread protector 60 is removed from tool 50 activating switch 10 . Processor/timer 70 is deactivated when thread protector 60 is reconnected to corresponding tool 50 . In other embodiments, timer 72 may be a timer circuit with memory, rather than software on processor 70 . The timer and/or processor preferably comprises a non-volatile memory to keep track of multiple on and off useage.
[0052] In this embodiment, end protector/thread protector 60 and tool 50 connect by way of threadable portion 62 and threadable portion 52 , respectively, whereby thread protector end 44 contacts tool shoulder 42 when fully connected. Switch 10 is positioned on inner shoulder 12 of thread protector 60 to engage tool wall end 14 when thread protector 60 is connected to tool 50 .
[0053] The location of GPS 30 , camera 20 , processor 70 , and battery 40 is not fixed within the end protector/thread protector, and can be moved consistent with the present invention where best suited for their function. For example, camera 20 is preferably located with a line of sight to the code to be read for a particular tool.
[0054] FIG. 3 is a block diagram of product operations tracking system 300 in accord with one possible embodiment of the present invention. Processor/timer 370 may comprise a software timer within a processor, a processor with separate timer, a dedicated timer circuit with non-volatile memory, or any other suitable circuitry to perform the intended timing function as discussed herein. Switch 310 may be used to turn the processor or dedicated timer on and off. Accordingly item 370 may be referred to herein as processor/timer 370 . A non-volatile memory can be used to store each time of use of the tool.
[0055] Processor/timer 370 is operably connected with battery 340 to provide power for camera 320 , GPS 330 , and antenna 350 . In one embodiment, the entire circuit may be turned off until turned on with switch 310 . In another embodiment, a processor may operate in a sleep mode until turned on with switch 310 . Once switch 310 is activated, processor/timer 370 initiates the timer function. Camera 320 takes a picture of or otherwise identifies tool identification mark 56 (See FIGS. 1 & 2 ). GPS 330 tracks the location of product operations tracking system 300 . Configured in this arrangement, camera 320 , GPS 330 and related antenna 350 will not draw power from battery 340 unless processor 370 allows for that function, e.g., after the switch 310 is activated.
[0056] When the end protector/thread protector is put back on to the tool, then switch 310 is deactivated. At this time, processor/timer 370 powers down and closes the connection between battery 340 and the remaining tracking components, i.e., GPS 330 , antenna 350 , and camera 320 . The time and/or other information such as GPS information and/or cameral information is stored in a non-volatile memory for processor/timer 370 or non-volatile memories for GPS 330 or camera 320 . In one embodiment, the last picture for each use by camera 320 will be obtained as the end protector/thread protector is being reconnected or shortly after reconnection to verify that the end protector/thread protector is placed on the same tool. As well, GPS 330 is preferably turned off when the thread connector is replaced.
[0057] The process repeats each time the end protector/thread protector is removed. The timer is started, a camera shot is taken and a GPS fix is attempted. When reconnected and switch 310 switches off, then processor/timer 370 obtains a time and stores the time in a non-volatile memory. The switch shuts off the camera. Alternatively, a camera shot is taken and/or a GPS position fix is attempted. Once the camera shot is completed and/or a GPS fix is obtained, then the processor/timer 370 powers off.
[0058] The above sequence discussed above is repeated each time the end protector/thread protector is removed/connected. When the tool is returned to the tool owner or lessor, the non-volatile memory downloaded to provide the information of use such as time and location of use. In one embodiment, this involves interrogating the non-volatile memory of processor/timer 370 to show the time of use for each use of the tool. The non-volatile memory of camera 320 (or other type of detector 320 such as RFID, bar code, or shows pictures of visual indicator 56 for each time the end protector/thread protector is removed or replaced.
[0059] FIG. 4 is an alternative block diagram of product operations tracking system 400 in accord with one possible embodiment of the present invention. First, end protector/thread protector 60 is removed or reconnected at 410 . Next, switch activates and/or deactivates the processor with timer or dedicated timer circuit for utilization tracking of the tool at 420 . Then at 440 , the battery powers the tracking system, i.e., camera and GPS. Following step 440 , the camera or other detector activates to take pictures of barcode or markings to verify equipment at 450 , and GPS activates to track utilization of equipment and/or location of equipment at 460 . Finally, tracking information transmitted to service center at 430 . This may be accomplished by reading the non-volatile memory after return of the tool. The camera and timer may continue to operate until reconnected whereupon a final camera shot may be produced and the timer stops with the final time recorded in non-volatile memory. In one embodiment, the timer or processor begins a new time sequence for each subsequent use, which is stored in non-volatile memory. Likewise for each subsequent use a new camera shot is obtained and/or a GPS fix is attempted. In one embodiment, the present invention may comprise a cellular telephone circuit to transmit a signal at the time of removal and/or replacement. However, this type of circuit is often not available at remote rig locations.
[0060] FIG. 5 is a flowchart of the life cycle for product operations tracking system 100 in accord with one possible embodiment of the present invention. Step 510 involves manufacturing of tracking component system within end protector/thread protector. The provider utilizes/initiates product operations tracking system and installs tracking end protector/thread protector on the equipment or tool at Step 520 . The identifier of the tool may be built into the tool by some means such as etching, stamping, or the like. In Step 530 , tracking end protector/thread protector and tool are shipped and monitored by service center (if a cellular telephone circuit is provided) until return of equipment to provider. At Step 540 , the client or end user removes end protector/thread protector from tool to begin operations and this activates utilization tracking of tool by client. Next, end user terminates operation of equipment and reconnects end protector/thread protector to tool to deactivate utilization tracking at Step 550 . At 560 , the client continues cycle until equipment or tool is no longer required and shipped back to provider. Finally, at step 570 the equipment is shipped and returned to provider with service center tracking and acquired information regarding the utilization time of tool, the location history of asset, and the like.
[0061] In summary, the present invention provides various embodiments of an end protector/thread protector that is modified as shown in FIG. 1 or FIG. 2 with system 100 as discussed herein. Various configurations for the structure or organization of the invention are discussed in FIG. 3 and FIG. 4 as discussed herein. Possible non-limiting uses of the equipment are shown in FIG. 5 as discussed herein. While a thread protector is one preferred embodiment, any end protector, whether threaded or not, which is mountable to some location of the oilfield tubular could conceivably be utilized for timing of usage purposes although a thread protector is a presently preferred embodiment.
[0062] The foregoing description of the preferred embodiments of the invention has been presented for purposes of illustration and description only. It is not intended to be exhaustive nor to limit the invention to the precise form disclosed; and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to a person skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.
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A product operations tracking system involves an apparatus and system to track and monitor the operational use of assets, with an emphasis on tubular products in the oil and gas industry. A tracking device is manufactured into an end protector, such as a thread protector, attached to an asset, which in a preferred embodiment will include a camera, a GPS and related antennas, an on/off switch, a timer which may comprise software in a processor, and a power source. The removal of the end protector begins operation of a timer which will deactivate once thread connector is reconnected to the equipment to log actual usage history of the typically rented or leased asset. Once the equipment is returned to the owner, the record in the tracking device indicates the time of usage.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to sprinkler heads and especially to a sprinkler head having a removable weighted collar.
[0002] Mechanically moved irrigation systems are commonly used throughout the United States for irrigating agricultural lands. Generally, the mechanically moved irrigation systems include a plurality of wheeled towers supporting a linear water conduit in a manner that the wheeled towers and water conduit can be moved through an agricultural field for changing the position of irrigation sprinklers coupled to the water conduit. One end of the water conduit is coupled to a water main or well and sprinkler heads are mounted in spaced alignment along the water conduit between the wheeled towers. The irrigation system may be moved in an agricultural field by a motor coupled through a gear box to the wheels of the towers.
[0003] One type of mechanically moved irrigation system in common use is a center pivot irrigation system used in the irrigation of large fields. These typically are comprised of a linear water conduit which is pivotally connected at one end to a source of water under pressure. The water conduit is carried in an elevated position by a plurality of spaced wheeled towers which are powered by hydraulic, pneumatic or electric motors to rotatably sweep the central conduit over a central pattern in a field. The central conduit includes a plurality of water sprinkling heads spaced over its length for distributing a spray of water on the circular field area as the center pivot irrigation conduit passes thereby. The center pivot and other wheeled line irrigation systems have been successful for uniform distribution of water over a field crop.
[0004] The current practice in these irrigation systems is to connect drop hoses to the water main with conventional couplings and then have the hoses drop near the field below and have sprinklers attached to the end thereof for distributing the water adjacent the crops.
[0005] Prior U.S. patents using weighted collars can be seen in Applicant's prior U.S. patent to Santiesteban et al., U.S. Pat. No. 6,382,525, which is a sprinkler head with a shielded weighted collar used to reduce vibrations and to deflect water from a sprinkler head while shielding the sprinkler head from physical damage. The Landry U.S. Pat. No. 6,808,135 is for a fluid-filled weight, particularly suited for use in irrigation systems. The Nelson et al., U.S. Pat. No. 6,997,406, is for a hose weight with ballast for use in an irrigation drop tube system and includes an elongated hollow core sleeve. The prior U.S. patent to M. D. Walklet, U.S. Pat. No. 3,226,117, is a bar bell disk weight construction having hollow weights for filling with a fluid material as does the J. W. Newman, U.S. Pat. No. 3,171,652, for an exercising weight filled with solidifying material.
[0006] One of the problems that occurs with sprinkler heads is sprinkler movement from the wind which can result in wear and premature failure of a sprinkler head. The present invention holds the sprinkler head down and prevents it from blowing around and at the same time forms a collar which continuously maintains a snug fit on the sprinkler head to prevent movement between the weight and the sprinkler head to prevent wear and damage from the movement of the weight on the sprinkler head.
SUMMARY OF THE INVENTION
[0007] The present invention relates to a sprinkler head having a removable weighted collar thereon. The sprinkler head body has an upper body portion having an elongated tapered water inlet having a water passageway therethrough. The tapered body portion also has a nozzle for directing water from the water inlet while the sprinkler head body lower body portion has at least one arm extending therefrom. A weighted collar has a tapered bore therethrough with the taper being sized to fit over the elongated taper water inlet to wedge thereon. The weighted collar is thus prevented from moving relative to the sprinkler head body water inlet due to vibration and movement of the sprinkler head. The weighted collar has a hollow interior which can be filled with any material for adding weight to the collar but granular magnetite is one preferred material. The elongated water inlet has a threaded end portion for attaching a water supply and may be either removably attached to the sprinkler head or formed as part of the sprinkler head body. The weighted collar bore taper is sized to ride on the water inlet taper to thereby allow continuing wedging thereon from the vibration of the sprinkler head allowing the weigh to settle down further on the taper and preventing movement of the weight relative to the sprinkler head.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Other objects, features, and advantages of the present invention will be apparent from the written description and the drawings in which:
[0009] FIG. 1 is an exploded view of the sprinkler body and weighted collar of the present invention;
[0010] FIG. 2 is a perspective view of the tapered water inlet collar support of FIG. 1 ;
[0011] FIG. 3 is a sectional view taken through the sprinkler head having the weighted collar attached; and
[0012] FIG. 4 is a sectional view of the weight collar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0013] Referring to the drawings, FIGS. 1 through 4 , a sprinkler body 10 can be seen having an upper body portion 11 having a plurality of arms 12 extending downward therefrom. The upper body has a nozzle portion 19 and has an elongated tapered water inlet 13 which is also the tapered support for the weighted collar 14 . The elongated water inlet and weight support, as shown in FIG. 2 , has a threaded attachment 15 for attaching to the sprinkler body 11 . It should be clear, of course, that this part can be molded into the sprinkler head 10 . The elongated tapered water inlet 13 also has a threaded portion 16 for attaching to the drop hose of a central irrigation system.
[0014] The weighted collar 14 can be seen having a passageway 17 passing therethrough which passageway, as seen in FIGS. 3 and 4 , has an annular tapered surface 18 , which taper is sized to fit onto the elongated tapered water inlet 13 , as shown in FIG. 3 , such that the weighted collar taper 18 will fit onto the tapered surface 20 of the elongated water inlet 13 and wedge thereon without quite reaching a flange 21 at the end of the taper 20 . This allows the continued vibration and movement of the sprinkler head 10 to further wedge the weighted collar 14 downward onto the tapered surface 20 , always maintaining a snug fit to prevent any vibration or movement between the weighted collar 14 and the sprinkler head 10 . This prevents wear and tear on both the weighted collar and the sprinkler head.
[0015] The weighted collar 14 can be seen having a hollow interior 22 , as seen in FIGS. 3 and 4 . Also as seen in FIG. 3 , the elongated taper water inlet 24 is formed into the sprinkler head 10 upper body portion 11 rather than being removably threaded thereto, as seen in FIGS. 1 and 2 . The hollow portion 22 of the weighted collar 14 can be filled with any fluid, granular material but Applicant has found that a granular magnetite or black iron oxide (FE3O4) is an ideal material adding a substantial weight to the collar 14 for the small size of the hollow area 22 . This material advantageously reduces the cost of a weighted collar for the sprinkler head over a solid brass or other metal collar and is mounted in a plastic weighted collar 14 so that corrosion is avoided for the weighted collar.
[0016] It should be clear that the present invention also contemplates a weighted collar of a solid brass or metal or other weighted collar having an angled bore therethrough sized to be dropped onto and fit onto an annular tapered water inlet of an upper sprinkler body. The present invention is not to be construed as limited to the forms shown which are to be considered illustrative rather than restrictive.
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The present invention relates to an irrigation sprinkler head having a removable weighted collar thereon. The sprinkler head has a tapered water inlet for wedging a weighted collar having a matching tapered opening therethrough.
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This is a division, of application Ser. No. 681,108 filed Apr. 5, 1991 now U.S. Pat. No. 5,173,364.
FIELD OF THE INVENTION
The invention relates to a glass fibre reinforced plasterboard and a method for producing same.
DESCRIPTION OF THE PRIOR ART
Plasterboards or gypsum boards, which are manufactured at large formats with a thickness of 5 to 20 mm, are mainly used for interior construction. In order to increase their flexural strength, it is known to provide the outer layers of the board with a sheath, for example of cardboard, which externally covers a gypsum core and which is firmly connected to the gypsum (plastercardboard). Another method of reinforcement is applied for gypsum boards with an intended high degree of fire resistance. The gypsum boards then comprise several layers, the outer ones containing fibreglass fleece (U.S. Pat. No. 3,993,822), whilst the gypsum core is composed of a mixture of gypsum and water, if required with short glass fibres or mineral fibres added (DE-AS 1 033 123).
Also known are light-fibre gypsum boards (DE-OS 2 728 581) with a light core board manufactured of gypsum, chopped glass fibres and foam generating materials, the core board being surrounded on all sides by fibre mats which are laid into a form into which the gypsum slurry is poured. These fibre mats can be woven or manufactured materials, but also fleece material of synthetic fibres, which give the board the desired stability whilst their gypsum core, which in itself is of low breaking resistance, offers the required form stability. The materials used and the construction of the board demand complicated, cost-intensive manufacturing, resulting in a high price of such coated boards which limits their possible applications.
There are also other glass fibre reinforced gypsum boards whereby the glass fibres are arranged to be concentrated immediately underneath the top surface of the board (U.S. Pat. No. 4,195,110). This known type of board is very elaborate in its manufacturing process as it has to be cast of separate gypsum layers of different density.
In another type of gypsum board with a multi-layer structure (DE-OS 27 17 276), the matrix of crystalline gypsum also contains glass fibres and asbestos fibres and is formed so that a core layer of lower density transides continuously into respective exterior layers of higher density. A multi-layer product of this type is very difficult to manufacture. It is particularly difficult to regulate the density of the individual layers so that the denser layers are at the exterior sides and the layers of lesser density in the middle. Furthermore, this production necessitates working with a water surplus which has to be drawn off after casting the board. After casting, it is further necessary to subject the board to a pressurising process in order to achieve a firm inner bond between the individual gypsum layers.
All layered, surface-sheathed and glass fibre reinforced gypsum boards have in common that their layers are inclined to separate from one another either during the manufacturing process or later whilst in use as the adhesive- and shearing strength in the bordering surfaces between the individual layers is generally less than inside each layer.
In order to avoid the disadvantages of sandwich-like constructed boards, glass fibre reinforced gypsum boards are known which have 2%-vol. glass fibres of short lengths mixed into the gypsum compound as a reinforcement (DD Patent 139 614). During the manufacture, the gypsum is sprinkled into a mixture of water, foam material and fibre material which has been foamed up prior to adding the bonding substances. The foaming up is to assure that the finished product has a cell structure and is, in consequence, of lesser weight and easier to work with, i.e. it permits either sawing, nailing or clamping. However, sprinkling gypsum into the foamed-up substance does not achieve thorough mixing of gypsum and glass fibres, in particular as the short cut glass fibres, henceforth called "chopped fibres", are inclined to adhere to each other due to adhesive properties, so that the individual glass fibres do not embed themselves in the gypsum matrix and are not surrounded by same at all sides. In particular if anhydrite is used according to this known proposal, then the finished product is inhomogenous and has highly differing stability.
In the manufacture of a similarly based fibre reinforced gypsum board (GB-PS 1 437 040), a prepared foam is added to a stiff mixture of gypsumhalfhydrate and water. In a subsequent production stage, glass fibre pieces of short length are mixed into this reliquefied gypsum mixture. In spite of the following mixing process in the mixer, the short fibreglass pieces are not sufficiently bonded in the gypsum matrix, so that they cannot serve as desired as reinforcing agents, and the finished board has a relatively low density, but also only limited break resistance which does not go beyond 2.2 MN/m 2 .
With regard to a continuous production of glass fibre reinforced gypsum boards, it has already been suggested to feed a mixture of glass fibres and an aqueous gypsum compound from a funnel into a mould or onto a surface which moves along under the funnel opening (GB-PS 1 483 046). Internal vibrators, which are flowed around by the mass and vibrate it in a certain direction and at the same time align the glass fibres in the mass, are arranged in the funnel outlet opening to permit the glass fibre reinforced gypsum compound to run out of the funnel and spread out on a forming table. This vibration also removes air- and gas bubbles trapped in the mass, and a gypsum board is produced which is of relatively high rigidity but also very heavy and difficult to work with due to its high density. If the glass fibres are aligned in one direction during the manufacturing process, then the flexural strength of the boards differs in different directions.
SUMMARY OF THE INVENTION
It is an object of the invention to provide a glass fibre reinforced gypsum board which is more homogenous and of virtually equal rigidity in all directions, but only of low overall weight and easily processed. Furthermore, it is an object of the invention to provide a process for continuous manufacture of glass fibre reinforced gypsum boards even on conventional gypsum board producing equipment.
These objects are achieved by features specified in the claims.
A glass fibre reinforced gypsum board of the desired properties is characterised according to the invention by the following features:
a) a gypsum matrix (CaSO 4 2H 2 O), made from a hemihydrate and water, the density of which is at least 1.35 g/cm 3 and at least 25% higher than the density of the finished board;
b) glass fibres as reinforcement, having a diameter of 5-20 μm and a length of 2-20 mm and in a quantity of 0.3-3.0 weight-% of the finished board, evenly distributed therein;
c) a plurality of voids, evenly distributed in the skeleton of solid material, which is composed of the gypsum matrix and the glass fibres, and each individual void having a diameter of 5-350 μm and altogether taking up a volume of at least 20% of the overall finished board.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
When manufacturing a gypsum matrix of hemihydrate and water and with a density of at least 1.35 g/cm 3 , then this is based on a water/gypsum ratio of between 0.4 and 0.60. Preferably, the water/gypsum ratio is 0.4-0.55. In the following, "water/gypsum ratio" is understood to mean theweight ratio of the total liquid, i.e. water, foam water and, if appropriate, liquefier, to the entire solid material quantity which, apartfrom hemihydrate, includes glass fibers and, if appropriate, free-flowing or pourable fillers. Such a low water/gypsum ratio produces a gypsum matrix of high density and final strength, because after the setting and drying of the gypsum in the matrix only those pores remain which originatefrom evaporation of the surplus water in the matrix.
A gypsum compound of a water/gypsum ratio between 0.4 and 0.60 can still flow freely under its own weight, however, if according to the invention glass fibers as chopped fibers with a diameter of 5 to 20 μm and a length of 2 to 20 mm are added at a quantity of 0.3 to 3.0 weight-% of thefinished board, then the paste becomes so thick that it will no longer flowunder its own weight. It can then be processed only with difficulties by a rotary mixer as used in conventional gypsum-board production plants, because the increase in viscosity causes shearing forces in the mixer which are so high that the installed output of the mixer has to be increased considerably, and jamming of the mixer must be expected.
However, by mixing in a separately made thick foam of a suitable tenside and/or by adding non-porous and non-water absorbing solid and hollow filler materials with particles no larger than 350 μm, it is surprisingly achieved that the viscosity of the initially very stiff mixture, which disperses glass fibers well, is again reduced to such an extent that this mixture can be processed easily in conventional rotary mixers. When using a micro foam, the cell structure of the foam is hardly changed in this process and voids of 5-350 μm in diameter develop in the mixture. Thus, the gas bubbles of the foam are not joined by the shearing action into large, macroscopic air bubbles which would result in an inhomogenous product of small mechanical strength, instead the microscopic gas bubbles, like the ball-shaped solid body particles of the paste, render the product thereof a homogenous structure with evenly distributed microscopic voids.
In embodying the invention, the foam may have an apparent density of maximum 0.12 g/cm 3 . Preferably, the foam forming material is a tenside or a polyvinylalcohol. The paste will then flow easily from the rotary mixer without forming lumps. It has a much improved cohesion relative to a gypsum compound of higher water/gypsum ratio. On a moving surface under the mixer outlet, for example a moving conveyor belt on which the produced boards harden and are cut and dried, the mass is then subjected, according to the invention, to a vibration, for example by a shaker, so that it spreads out flat and larger air pockets are expelled. Even when adding a thicker foam into the mixer, the micro gas bubbles in the foam are surprisingly not destroyed by this vibration, but form micro cells which, after the gypsum has set, are spread out in the end product which is then of an overall porous structure, but comprising a dense matrix. This gypsum matrix, which firmly encloses and bonds the individualchopped glass fibers, forms an extremely pressure resistant and flexurally resistant skeleton of solid particles which is interpersed by evenly spaced gas bubbles, established by the foam or the hollow solid body particles.
If non-porous or non-water absorbing free-flowing or pourable fillers are to be added totally or partially in lieu of a foam, then they should be spherical with an apparent density of no more than 0.7 q/cm 3 . The size of the individual particles should be <350 μm, whereby light fillers of up to 20 weight-% of the finished board can be added. The fillers can be, for example, hollow glass balls or spherical solid bodies (cenospheres) of fly ash. Balls of synthetic materials can also be used.
After forming, bonding and drying, the end product is of a homogenous composition and is characterised by a bonding-matrix of high density and by low apparent density and high strength. The apparent density lies between 0.6 g/cm 3 and 1.08 g/cm 3 , whilst the gypsum matrix has adensity of at least 1.35 g/cm 3 , thus being at least 25% larger than the apparent density of the overall mixture.
The basic material gypsum, i.e. calciumsulphatebetahemihydrate, should be pure as in pure natural gypsum, chemical gypsum or FGD gypsum. Best results are obtained by means of hemihydrate of gypsum which occur in fluegas desulphurisation plants (FGD gypsum). The applied quantity can be between 80 and 99.5 weight-% of the total quantity of solids.
Preferred for use as glass fibers are chopped fibers which in water divide into individual fibers, with a length of between 2 and 20 mm, preferably with a length of 7 mm, and in a quantity of 0.3 to 3.0 weight-%, preferably in a quantity of 1.0 to 2.0 weight-% of the total weight of theboard.
Depending on the type of product to be manufactured, it is also possible toadd a plurality of additives, for example polystyrene balls, mica, clay, fly ash, vermiculites, other known silicates and aluminium-silicates. Furthermore, processing aids, such as known types of accelerators, retardants and liquefiers, can also be applied.
In a process of manufacturing boards embodying the invention, the gypsum, the fibers and, if appropriate, the solid fillers are mixed, and the resulting mixture is filled into a rotary mixer. At the same time, the required quantity of water and separately produced foam are separately added and mixed with the solids. The paste, which has been thoroughly processed by the mixer, is then poured into a form, which is transported under the mixer outlet, or onto a conveyor surface which are for a limitedlength subjected to a vibration during which the paste spreads and is shaped. The mass dries and is cut into the desired boards and dried.
After setting and drying, a mechanically isotropic glass fiber reinforced gypsum board is obtained in which the solid components, substantially composed of glass fibers and re-hydrated gypsum, have a density which is substantially higher than the apparent density of the overall product.
The gas bubbles, placed inside the finished board by way of the foam, have an average diameter of approximately 50 μm. Overall, they take up a volume of at least 20% of the entire finished board.
In order to obtain a good, even and non-aligned distribution of the glass fibers in the gypsum matrix, they are initially dry-mixed with the gypsum and, if appropriate, with the solid fillers, and filled together with theminto the rotary mixer. It is also possible to enter all solids in an unmixed state into the mixer and to loosen them up by vorticity.
Below, two examples for the invention are given:
EXAMPLE C
A mixer of the ERSHAM type is loaded with 791 kg/h hemihydrate, 14 kg/h chopped glass fibers of 7 mm length of HTH 8144 Rovings, 325 l/h water with the addition of 0.2% of the water-reducing substance TAMOL NH and a foam which has been brought up to an apparent density of 0.1 g/cm 3 byfoaming 50 l/h of a 1% solution of the foam substance GYP2 with air. The paste flowing out of the mixer is then spread by way of vibration to a board of 12.6 mm thickness. The paste density was 1.34 g/cm 3 , the density of the thus formed dried board was 1.01 g/cm 3 . The break resistance of the board was 10.5N/mm 2 .
Composition of the board: 98.5 weight-% dihydrate, 1.5 weight-% glass fibers.
Ratio of water to solids: 0.47
EXAMPLE D
A mixer of the ERSHAM type is loaded with 1059 kg/h hemihydrate, 31 kg/h chopped glass fibers of 13 mm length of HTH 8144 Rovings, 320 kg/h of hollow glass-bead fraction (cenospheres) obtained from fly ash and 690 l/hwater with an addition of 0.2% of the water-reducing substance TAMOL NH. The paste flowing out of the mixer is then spread by way of vibration to aboard of 13.8 mm thickness. The density of the paste was 1.37 g/cm 3 , the density of the thus formed dried board was 1.01 g/cm 3 . The break resistance of the board was 8.8N/mm 2
Composition of the board: 78.1 weight-% dihydrate, 1.9 weight-% glass fibers, 20% cenospheres.
Ratio of water to solids: 0.49
A comparison of the board compositions in examples C and D with other boardcompositions is shown in the following chart:
__________________________________________________________________________Board Composition (in weight-%) Properties Water/ Apparent Break Glass Fibres Solid Gypsum## Density ResistanceExampleGypsum 7 mm 13 mm Foam Fillers# Liquefier Ratio g/cm.sup.3 N/mm.sup.2__________________________________________________________________________A 98.5 -- 1.5 -- -- 0.2 0.45 1.30 11.6B 98.5 1.5 -- -- -- 0.2 0.49 1.26 12.7C 98.5 1.5 -- + -- 0.2 0.47 1.01 10.5D 78.1 -- 1.9 -- 20 0.2 0.49 1.01 8.8E 98.5 1.5 -- -- -- 0.2 0.75 1.02 5.0F 98.5 1.5 -- -- -- 0.2 0.85 0.95 3.2__________________________________________________________________________ # (Cenospheres) ## Ratio of water and foam to halfhydrate and, if appropriate, fillers
comparing the examples A through F, one notices that the preferred compositions C (using foam) and D (using lightweight hollow spheres-cenospheres) give break resistances that are more than twice the values of examples E and F (without foam or lightweight hollow spheres) respectively. This is so even though all of Examples C, D, E and F includesubstantially the same glass fiber content and the apparent densities of the products are substantially the same. Quite surprisingly, the break resistances of C and D are much closer to those obtained in Examples A andB although the apparent densities of the latter are much higher, the glass fiber content is the same as in C and D, the water/gypsum ratios are similar and no foam or lightweight fillers are used in A and B. This comparison shows that only the compositions according to the invention give an optimum result i.e. products that are both strong and lightweight.
With the water/gypsum ratio higher than specified herein, equally small or smaller apparent densities can be produced, but the break resistance is reduced by more than half. The desired optimum is thus achievable only as has been described.
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Glass fibre reinforced plasterboard including a gypsum matrix of high density with embedded staple glass fibres therewith forming a pressure resistant solid body frame in which are embedded a plurality of very small hollow spaces of 5-350 microns in diameter, produced by a fine-pore foam or at least partially by small particles of non-porous and non-water absorbing fillers. During the manufacturing process of such glass fibre reinforced gypsum board, the gypsum and the fibre pieces are given only so much water that the water/gypsum ratio does not exceed 0.6, whereafter a foam and/or pourable or free-flowing fillers are added in such quantities that the apparent density of the entire board is at least 20% smaller than the density of the bonding means component of the matrix, and the paste is subjected while being formed to a vibration.
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This application is a divisional application of U.S. patent Ser. No. 07/352,327, now U.S. Pat. No. 5,003,078 filed May 16,1989.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates, in general, to high temperature materials and, in particular, to a new class of aromatic phthalonitrile monomers containing ether and imide linkages and their conversion to high temperature thermosetting polymers and copolymers and the synthesis thereof.
2. Description of the Prior Art
Interest in fiber-reinforced composites for advanced aerospace applications has led to the search for high temperature polymers that are easily processed and exhibit high thermal and oxidative stability. Presently, epoxies and polyimides are used. These materials have superior mechanical properties and are lighter and more economical to produce than metals but lack the thermal stability to operate at high temperatures and tend to oxidize and become brittle over time. Conventional epoxy-based composites and adhesives are limited to 120° C. maximum, have a problem with water absorption and require low temperature prepreg storage. Polyimides can produce gaseous products when cured, resulting in voids and blisters in composite components.
Phthalonitrile polymers constitute a recent and important class of high-temperature materials, having a wide range of uses, such as composite matrices, adhesives, sealants, and even semiconductors. These polymers are prepared from phthalonitriles in which the linking group between the two ortho dinitrile groups separates the dinitrile groups enough to permit polymerization. Presently several bridging groups are known. Examples include aliphatic and unsaturated groups, aromatic groups, aliphatic and aromatic diamide groups, and aliphatic and aromatic ether, sulfone and ketone groups.
The chemical and physical properties of the polymers depend primarily on the bridging groups. The groups providing the best properties are those with aromatic, polar and flexible moieties, especially the --O--φ--φ--O group of U.S. Pat. No. 4,259,471 by Keller et al., the --O--φ--C 3 F 6 --φ--O-- of U.S. Pat. No. 4,238,601 by Keller et al., the --O--C 3 --H 6 --φ--O-- group of U.S. Pat. No. 4,223,123 by Keller el. at, the --O--φ--SO 2 --φ--O-- and --O--φ--(C═O)--φ--O-- groups of U.S. Pat. No. 4,234,712 by Keller el at and the --O--C n --H 2n --O-- group of U.S. Pat. No. 4,226,801 by Keller el al. These polymers have exceptional thermal and oxidative stability, low water absorptivity, high strength, good dimensional integrity and strong adhesion. The aromatic moieties provide the high mechanical strength, modulus and high thermal and oxidative stability and the polar moieties provide the excellent adhesive properties.
U.S. Pat. No. 4,408,035 teaches curing of phthalonitrile monomers with a nucleophilic aromatic amine. The monomer, 4,4' -bis(3,4-dicyanophenoxy)biphenyl, has a melting point of 232°-234° C. The aromatic diamines covered in the above patent are somewhat volatile at the required processing melt temperature, causing void problems when used in an amount greater than 5% by weight. It is advantageous for a resin not to produce gaseous products when cured. Also, the chemical makeup of the polymer must be such that it consists of units having known resistance to bond-rupture under thermal, oxidative and hydrolytic conditions.
U.S. patent application Ser. No. 07/273,443 discloses 1,3-bis(3-aminophenoxy)benzene and other bis(aminophenoxy) compounds used as a curing agent for a rapid synthesis of phthalonitrile resin. The time and temperature needed for polymerization of bisphenol-linked phthalonitrile monomers are easily controlled as a function of the concentration of amine curing agent.
The necessity for aromatic and heterocyclic ring structure in a polymer to achieve heat resistance has long been recognized. The ideal heat resistant polymer would be composed of aromatic and/or heteroaromatic ring structures interconnected by flexible linkages within the polymeric backbone to improve processability and to enhance the mechanical properties. However, few synthetic methods are available for incorporating stable linkages into a polymeric system.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to synthesize phthalonitrile monomers, polymers and copolymers with excellent thermal and oxidative properties and good mechanical properties in excess of 300° C.
And, an object of this invention is to produce polymeric materials for composite matrices to be used in applications where the use temperature is above the operating temperature for conventional high temperature polymers and below the operating temperature for ceramics or metals.
Also, an object of this invention is to produce polymeric material which are free of voids.
Further, an object of this invention is to provide new type of phthalonitrile resins having aromatic imide and ether linkages in the bridge connecting the terminal phthalonitrile polymerizable units.
Additionally, an object of this invention is to provide a resin which is more resistant to oxidative attack than epoxies, bismaleimides and other conventional thermosetting polyimides.
These and other objects are accomplished by reacting an aminophenoxyphthalonitrile with an aromatic anhydride to produce an amic acid linked phthalonitrile which can be imidized either by chemical and/or thermal means. The resulting phthalonitrile resin is processed either alone or in the presence of a bisphenol-based phthalonitrile which behaves as a reactive plasticizer. Polymerization of the neat resin or polymeric blend is achieved by heating above the melting point or softening temperature in the absence or presence of aromatic di- or poly-amines, metal and/or metallic salts.
DESCRIPTION OF THE PREFERRED EMBODIMENT
The imide-containing phthalonitrile monomers of this invention are represented by the formula: ##STR1## where R is an aromatic tetravalent radical or substituted aromatic tetravalent radical. By the word "substituted", it is meant in this application that any known substituent could be attached to the aromatic moiety. Substituents include but are not limited to halogens, chalcogens and organic radicals, such as phenyl, alcohol, carboxyl, carbonyl, or aliphatic groups of less than 10 carbon atoms. The preferred compounds are where R is an aromatic tetravalent radical of the general formula: ##STR2## where X is ##STR3## any alkyl of six carbons or fewer or any partially or perhalogenated alkyl of six carbons or fewer.
The most preferred compounds are where R is an aromatic tetravalent radical of the general formula: ##STR4## where X is ##STR5##
The imide-containing phthalonitrile monomers of this invention are prepared in solution by reaction of their precursors, 4-(3- or 4-aminophenoxy) phthalonitrile and an aromatic anhydride. The phthalonitrile monomers are synthesized by reaction of 4-(3- or 4-aminophenoxy) phthalonitrile with an aromatic anhydride. Upon isolation by pouring the reaction mixture into an appropriate precipitating solvent such as ethanol, complete imidization is achieved thermally in air at 300° C.
The imide-containing phthalonitrile monomers are prepared from 4-(3- or 4-aminophenoxy)phthalonitrile and an aromatic anhydride according to the following process: ##STR6## where R is as described above.
The 4-(3- or 4-aminophenoxy)phthalonitrile is prepared according to the following process: ##STR7##
Examples of the preferred anhydrides which are suitable for use in this invention are listed below:
4,4'-(hexafluoroisopropylidene)diphthalic anhydride pyromellitic dianhydride
3,3',4,4'-benzophenonetetracarboxylic dianhydride
2,3,6,7-naphthalene tetracarboxylic dianhydride 3,3',4,4'-diphenyl tetracarboxylic dianhydride
1,3,5,6-naphthalene tetracarboxylic dianhydride
2,2'3,3'-diphenyl tetracarboxylic dianhydride
2,2-bis(3,4-dicarboxyphenyl)propane dianhydride
bis(3,4-dicarboxyphenyl)ether dianhydride
naphthalene-1,2,4,5-tetracarboxylic dianhydride
naphthalene-1,4,5,8-tetracarboxylic dianhydride
decahydronaphthalene-1,4,5,8-tetracarboxylic dianhydride
4,8-dimethyl-1,2,3,5,6,7-hexahydronaphthalene-1,2,5,6-tetracarboxylic dianhydride
2,6-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride
2,7-dichloronaphthalene-1,4,5,8-tetracarboxylic dianhydride
2,3,6,7-tetrachloronaphthalene-1,4,5,8-tetracarboxylic dianhydride
phenanthrene-1,8,9,10-tetracarboxylic dianhydride
2,2-bis(2,3-dicarboxyphenyl)propane dianhydride
1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride
1,1-bis(3,4-dicarboxyphenyl)ethane dianhydride
bis(2,3-dicarboxyphenyl)methane dianhydride
bis(3,4-dicarboxyphenyl)methane dianhydride
bis(3,4-dicarboxyphenyl)sulfone dianhydride
benzene-1,2,3,4-tetracarboxylic dianhydride
4,4'-oxydiphthalic dianhydride
4,4'-thiophthalic dianhydride
The most preferred anhydrides are 3,3',4,4'-benzophenonetetracarboxylic dianhydride and 4,4'-(hexafluoroisopropylidene)diphthalic anhydride.
The imide-containing phthalonitrile polymers of this invention contain the repeating unit represented by the formula: ##STR8## where R is an aromatic tetravalent radical or substituted aromatic tetravalent radical as defined above. The preferred compounds are where R is an aromatic tetravalent radical of the general formula: ##STR9## where X is ##STR10## any alkyl of six carbons or fewer or any partially or perhalogenated alkyl of six carbons or fewer.
The most preferred compounds are where R is an aromatic tetravalent radical of the general formula: ##STR11## where X is ##STR12##
Polymerization of the phthalonitrile monomer is accomplished by heating the monomer mixture above its melting point, continued heating at a temperature above the glass transition temperature of the prepolymer amorphous reactants until the mixture reaches its gelation point, curing the mixture to complete crosslinking of the polymer and postcuring at a temperature from above the glass transition temperature of the polymer up to just below the carbonization temperature. Examples of cure cycles for neat polymerization are 1) a two-part cure of 225°-280° C. for 6-20 hours and 300°-315° C. for 10-20 hours; 2) a three-part cure of 225°-280° C. for 6-16 hours, 240°-300° C. for 2-6 hours and 300°-315° C. for 5-16 hours. The preferred two-part cure is 240° C. for 17 hours and 315° C. for 16 hours. The preferred three-part cure is 225° C. for 16 hours, 280° C. for 6 hours and 315° C. for 16 hours. The most preferred cure is the three-part cure.
The time and temperature needed for polymerization can be reduced by curing phthalonitrile resins in the presence of amine curing agents that are stable at the initially required processing temperatures. These amine curing agents do not volatilize during the polymerization reaction. The amine curing agents are of the general formula YNH 2 where Y is an aromatic. The amount of curing agent added should be in the range of 1 to 10 weight percent of the polymer mixture. The preferred amount of curing agent is 1 to 5 weight percent. The most preferred amount of curing agent is 1.5 to 2.0 weight percent.
Specific examples of amine curing agents useful in this invention are given below:
o-phenylenediamine
m-phenylenediamine
p-phenylenediamine
4,4'-diaminodiphenylpropane
4,4'-diaminodiphenylmethane (commonly named 4,4'-methylenedianiline)
4,4'-diaminodiphenyl sulfide (commonly named 4,4'-thiodianiline)
4,4'-diaminodiphenyl ether (commonly named 4,4'-oxydianiline)
1,5-diaminonaphthalene
3,3'-dimethylbenzidine
3,3'-dimethoxybenzidine
2,4-bis(β-amino-t-butyl)toluene
bis(p-β-amino-t-butyl)ether
bis(p-β-methyl-o-aminopentyl)benzene
1,3-diamino-4-isopropylbenzene
1,2-bis(3-aminopropoxy)ethane
benzidine
m-xylylenediamine
p-xylylenediamine
2,4-diaminotoluene
2,6-diaminotoluene
1,3-bis(3-aminophenoxy)benzene
3-bis(4-aminophenoxy)benzene
1,4-bis(3-aminophenoxy)benzene
1,4-bis(4-aminophenoxy)benzene
bis[4-(3-aminophenoxy)phenyl]sulfone
bis[4-(4-aminophenoxy)phenyl]sulfone
4,4'-bis(3-aminophenoxy)biphenyl
4,4'-bis(4-aminophenoxy)biphenyl
2,2-bis[4-(3-aminophenoxy)phenyl]propane
2,2-bis[4-(4-aminophenoxy)phenyl]propane
The most preferred amine curing agent is 1,3-bis(3-aminophenoxy) benzene (APB).
Examples of cure cycles for polymerization with amine curing agents are 1) a two-part cure of 225°-260° C. for 5-20 hours and 300°-315° C. for 5-20 hours; 2) a three-part cure of 180°-240° C. for 2-6 hours, 240°-300° C. for 2-8 hours and 300°-315° C. for 10-20 hours; 3) a four-part cure of 180°-200° C. for 1-3 hours, 200°-240° C. for 2-4 hours, 240°-280° C. for 4-6 hours and 300°-315° C. for 10-20 hours. The preferred two-part cure is 225° C. for 6 hours and 315° C. for 16 hours. The preferred three-part cure is 225° C. for 16 hours, 280° C. for 6 hours and 315° C. for 16 hours. The preferred four-part cure is 200° C. for 2 hours, 240° C. for 3 hours, 280° C. for 5 hours and 315° C. for 16 hours. The most preferred cure is the three-part cure.
After the cure cycle is complete, a postcure can be carried out to improve the mechanical and thermal properties of the material. The preferred postcure is 325°-365° C. for 2-6 hours and 365°-385° C. for 5-24 hours. The most preferred postcure is 350° C. for 4 hours and 375° C. for 12 hours. When postcure temperatures are in excess of 316° C., heating is under an inert atmosphere, such as nitrogen or argon.
It should be noted that the cure cycles and postcures given above are not intended to be complete and all inclusive. Other cure cycles and postcures are possible depending on variations in time, temperature and additives.
Polymerization and thus processibility phthalonitrile monomers are somewhat difficult due to the enhanced viscosity of these monomers compared to the bisphenol-based phthalonitrile of U.S. patent application Ser. No. 07/273,443. A reduction in the viscosity was achieved by copolymerizing the imide-containing phthalonitrile with these bisphenol-based phthalonitriles. The bisphenol-based phthalonitriles behave as reactive plasticizer. As the term implies, the role of the reactive plasticizer is to improve the processability and then, through reaction with the imide-containing phthalonitriles and itself, become a part of the cured resin system. Blends of imide-containing phthalonitrile and bisphenol-based phthalonitrile can be fabricated without seriously compromising the use properties. The amount of bisphenol-based phthalonitrile is in the range from 10% to 50% by weight. The preferred amount is in the range from 20% to 30% by weight. The most preferred amount is approximately 25% by weight.
A general formula of the bisphenol-based phthalonitrile useful as a reactive plasticizer is shown below: ##STR13## where A is any divalent organic radical, for example, a bisphenol group, a diether group or a dithioether group. The preferred diphthalonitrile monomers are those in which A in the formula above is a diether group, --R'--O. The most preferred diphthalonitrile monomers are those wherein R' is selected from the class consisting of ##STR14## wherein φ is a phenyl group, wherein the phenyl groups are linked at tho para and the meta positions and wherein "a" is any integer. The bisphenol-containing phthalonitrile monomers copolymerize with the imide-containing phthalonitrile monomers to form a copolymer with the following repeating unit: ##STR15##
It is possible with the present invention to include a metal or metal salt in the resins. For composite fabrication, a salt or a metal would be less desirable because of problems with homogeneity and gassing. Examples of suitable metal salts include cuprous chloride, cuprous bromide, cuprous cyanide, cuprous ferricyanide, zinc chloride, zinc bromide, zinc iodide, zinc cyanide, zinc ferrocyanide, zinc acetate, zinc sulfide, silver chloride, ferrous chloride, ferric chloride, ferrous ferricyanide, ferrous chloroplatinate, ferrous fluoride, ferrous sulfate, cobaltous chloride, cobaltic sulfate, cobaltous cyanide, nickel chloride, nickel cyanide, nickel sulfate, nickel carbonate, stannic chloride, stannous chloride hydrate, a complex of triphenylphosphine oxide and stannous chloride (2TPPO/SnCl 2 ) and mixtures thereof. The metals which can used include chromium, molybdenum, vanadium, beryllium, silver, mercury, aluminum, tin, lead, antimony, calcium, barium, manganese, magnesium, zinc, copper, iron, cobalt, nickel, palladium and platinum. Mixtures of these metal may also be used. The preferred metals are copper, silver and iron.
The invention having been generally described, the following examples are given as particular embodiments of the invention and to demonstrate the practice and advantages thereof. It is understood that the examples are given by way of illustration and are not intended to limit the specification or the claims to follow in any manner.
EXAMPLE I
Synthesis of Imide-Containing Phthalonitrile from 3,3',4,4'-benzophenonetetracarboxylic dianhydride (BTDA) and 4-(3-aminophenoxy)phthalonitrile
To a 100ml three-necked flask was added 3,3',4,4'-benzophenonetetracarboxylic dianhydride (5.4 g, 16.7 mmol) and 30 ml of dry dimethylformamide (DMF). After flushing the solution with nitrogen for 20 minutes, 4-(3-aminophenoxy) phthalonitrile (7.8 g, 33.3 mmol) was added under ambient conditions. The temperature of the reaction mixture was increased to 90° C. and held at this temperature for 1 hour. Toluene (30 ml) was added and the solution was heated to reflux. The water which was formed as a by-product was azeotroped from the mixture with a Dean Stark trap. Total reflux time was 12 hours. After removing the toluene by distillation and cooling, the white solidified product mixture was removed from the reaction vessel washed with ethanol, collected by filtration, dried and annealed at 200° C. for 2 hours to afford 11.9 g (93%) of imide-containing phthalonitrile, m.p. 245°-248° C.
EXAMPLE II
Synthesis of 6F Imide-Containing Phthalonitrile from 4,4'-(hexafluoroisopropylidene)diphthalic Anhydride and 4-(3-aminophenoxy)phthalonitrile
To a 100 ml three necked flask was added 4,4'-hexafluoroisopropylidene)diphthalic anhydride (5.0 g, 11.3 mmol) and 30 ml of dry dimethylformamide (DMF). After thoroughly flushing the solution with nitrogen, 4-(3-aminophenoxy) phthalonitrile (5.3 g, 22.3 mmol) was added under ambient conditions. The temperature of the reaction mixture was increased to 90° C. and held at this temperature for 1 hour. Toluene (30 ml) was added and the solution was heated to reflux. Water as formed was azeotroped from the mixture with a Dean-Stark trap. After refluxing for 12 hours, the toluene was removed by distillation. Upon cooling the product mixture was removed from the reaction vessel, washed several times with ethanol, collected by suction filtration, dried and annealed at 200° C. for 4 hours to complete the imidization reaction resulting in the formation of an amorphous material.
EXAMPLE III
Neat Polymerization of BTDA-Derived Imide Phthalonitrile
A 1 g sample of the imide-containing phthalonitrile was placed in an aluminum planchet and degassed in a specially designed desiccator for evacuation purposes at 280° C. for 3 hours. The viscous monomer was then placed in a oven preheated to 280° C. and cured in air by heating at 280° C. for 17 hours (overnight) and at 315° C. for 16 hours. Upon cooling the polymer was removed from the planchet and found to be void-free. A portion of the polymer was then postcured under an oxygen-free argon atmosphere at 350° C. for 4 hours and at 375° C. for 12 hours. The thermal and oxidative properties were enhanced as a result of the postcure treatment.
EXAMPLE IV
Polymerization of BTDA-Derived Imide Phthalonitrile with Amine Additive
A 1.0 g sample of BTDA-imide-containing phthalonitrile was placed in an aluminum planchet and degassed at 300° C. for 4 hours in a specially designed desiccator for evacuation purposes. After cooling to 250° C., 1,3-bis(3-aminophenoxy)benzene (APB, 2% by weight) was added to the viscous sample with stirring. After 2 hours at 250° C., the sample had gelled and become rubbery. The sample was then heated at 280° C. for 6 hours and at 315° C. for 16 hours (overnight). Thermogravimetric analysis (TGA) of powdered samples under both air and inert atmospheres showed no decomposition before 350° C. Between 550°-650° C., catastrophic oxidative degradation occurred. At 800° C. under a nitrogen atmosphere, the polymer exhibited a char yield of 60%.
EXAMPLE V
Polymerization of BTDA-Derived Imide Phthalonitrile with Amine Additive
A 0.5 g sample of BTDA-imide-containing phthalonitrile was placed in an aluminum planchet and degassed at 300° C. for 3 hours as in Example III. At this time, the sample was cooled to 210° C. and APB (5 mmol, 1% by weight) was added with stirring to the viscous monomer. The sample was then placed in an oven and cured by heating at 200° C. for 2 hours, at 220° C. for 3 hours and at 260° C. for 5 hours and at 315° C. for 16 hours. The sample exhibited a glass transition temperature (T g ) of 177° C. as determined by differential scanning calorimeter (DSC). When further postcured in a sequence under an oxygen-free argon atmosphere at 350° C. for 4 hours and at 375° C. for 12 hours, the sample did not exhibit a T g .
EXAMPLE VI
Polymerization of BTDA-Derived Imide Phthalonitrile with Stannous Chloride
A 0.5 g sample of the BTDA-imide-containing phthalonitrile was placed in an aluminum planchet and degassed as in Example III. To the melt as 260° C. was added SnCl 2 .H 2 O (0.035 g, 7% by weight) with stirring. The viscosity started to increase rapidly. Full gelation had occurred within 3 minutes. To complete the cure, the sample was heated at 260° C. for 6 hours and a 300° C. for 16 hours. Upon cooling, the polymer was removed from the planchet and appeared tough.
To another sample of the monomer (0.5 g) was added SnCl 2 .H 2 O (0.018 g, 3.6% by weight) with stirring at 260° C. Solidification occurred within 5 minutes at 260° C. To complete the cure the sample was heated at 260° C. for 6 hours and at 315° C. for 16 hours.
To a third sample of the monomer (0.5 g) was added SnCl 2 .H 2 O (0.005 g, 1% by weight) with stirring at 260° C. Full gelation was somewhat slower. Solidification had occurred after 20 minutes. To complete the cure, the sample was heated at 260° C. for 2 hours and at 315° C. for 16 hours.
EXAMPLE VII
Polymerization of 6F Imide-Containing Phthalonitrile with Amine Additive
A 0.5 g sample of the 6F imide-containing phthalonitrile was placed in a aluminum planchet and degassed as in Example III. To the melt was added 0.01 g of APB (2% by weight) with stirring. The sample was cured by heating at 260° C. for 3 hours and at 300° C. for 5 hours and at 315° C. for 10 hours. The polymer showed excellent thermo-oxidative stability as determined by TGA with the initial weight loss commencing at about 450° C. and the catastrophic decomposition occurring between 500°-700° C. In an inert atmosphere, the polymer exhibited a char yield of 60% at 800° C. When the polymer was postcured in sequence under an oxygen-free argon atmosphere at 350° C. for 4 hours and at 375° C. for 12 hour, it was found not to exhibit a T g . Moreover, an enhancement in the thermo-oxidative stability was observed with initial weigh loss commencing at temperature in excess of 500° C. No improvements in the thermal stability was observed.
EXAMPLE VIII
Copolymer of BTDA-Derived Imide Phthalonitrile and 4,4'-Bis(3,4-dicyanophenoxy)biphenyl Cured Neat
A sample containing 0.8 g of BTDA-imide-containing phthalonitrile and 0.2 g of 4,4'-bis(3,4-dicyanophenoxy)biphenyl was thoroughly mixed in an aluminum planchet and degassed in the melt at 260°-280° C. for 4 hours at reduced pressure in a specially designed desiccator for evacuation purposes. The monomeric blend, whose viscosity was considerably reduced relative to the neat BTDA-imide-containing phthalonitrile itself, was cured by heating in air at 225° C. for 16 hours, at 280° C. for 6 hours and at 315° C. for 16 hours. The blend solidified during the 225° C. heat treatment. The copolymer showed similar thermal and oxidative properties as found for the polymer derived solely from the BTDA-imide-containing phthalonitrile polymer. When the copolymer was further post cured in sequence at 350° C. for 4 hours and at 375° C. for 12 hours, it was found not to exhibit a T g .
EXAMPLE IX
Copolymer of BTDA-Derived Imide Phthalonitrile and 4,4'-Bis(3,4-dicyanophenoxy)biphenyl Cured with Amine Additive
A sample containing 0.8 g of BTDA-imide-containing phthalonitrile and 0.2 g of 4,4'-bis(3,4-dicyanophenoxy)biphenyl was mixed in a aluminum planchet and degassed as in Example VIII. To the melt of the blend was added 0.01 g of APB at 240° C. with stirring. The monomeric blend was then cured by heating in air at 225° C. for 16 hours (overnight), at 280° C. for 8 hours and at 315° C. for 16 hours. Gelation occurred during the 225° C. heat treatment.
EXAMPLE X
Copolymer of BTDA-Derived Imide Phthalonitrile (70%) and 4,4'bis(3,4-dicyanophenoxy)biphenyl (30% ) Cured with 2% By Weight of Amine Additive
A sample containing 0.70 g of BTDA-imide-containing phthalonitrile and 0.30 g of 4,4'-bis(3,4-dicyanophenoxy)biphenyl was mixed in a aluminum planchet and degassed as in Example VIII. The fluidity of the mixture was such that it was easy to process the sample above 200° C. To the melt at 225° C. was added 0.02 g (2% by weight) of APB with stirring. The monomeric blend was then cured in air by heating at 225° C. for 6 hours, at 280° C. for 2 hours and at 315° C. for 16 hours. Gelation occurred during the 225° C. heat treatment.
EXAMPLE XI
Copolymer of BTDA-Derived Imide Phthalonitrile (70%) and Bis[4-(3,4-dicyanophenoxy)phenyl]2,2-propane (30% ) Cured with 3% By Weight of Amine Additive
A sample containing 0.70 g of BTDA-imide-containing phthalonitrile and 0.30 g of bis[4-(3,4-dicyanophenoxy)phenyl]2,2-propane was mixed in an aluminum planchet and degassed as in Example VIII. Due to the low viscosity of the mixture in the melt relative to that of pure BTDA-imide-containing phthalonitrile monomer, the resulting mixture was easily processed above 200° C. To the melt of the monomeric blend at 225° C. was added 0.03 g of APB (3% by weight). The mixture was stirred for 15 minutes. The mixture was then cured in air at 225° C. for 16 hours and at 315 for 6 hours.
EXAMPLE XII
Copolymer of BTDA-Derived imide Phthalonitrile (70%) and Bis[4-(3,4-dicyanophenoxy)phenyl] Sulfone (30%) Cured With 2% By Weight of Amine Additive)
A sample containing 0.70 g of BTDA-imide-containing phthalonitrile and 0.30 g of bis[4-(3,4-dicyanophenoxy) phenyl]sulfone was placed in an aluminum planchet and degassed as in Example VIII. To the melt of the monomeric blend was added 0.02 g of methylenedianiline (MDA) with stirring. The mixture was cured by heating in air at 225° C. for 4 hours, at 280° C. for 4 hours and at 315° C. for 10 hours. Gelation occurred during the heat treatment at 225° C.
EXAMPLE XIII
Copolymer of BTDA-Derived imide Phthalonitrile (50%) and Bis[4-(3,4-dicyanophenoxy)phenyl] Sulfone (50%) Cured With 2% By Weight of Amine Additive)
A sample containing 0.50 g of BTDA-imide-containing phthalonitrile and 0.50 g of bis[4-(3,4-dicyanophenoxy) phenyl)sulfone was placed in an aluminum planchet and degassed as in Example VIII. To the low viscosity melt at 200° C. was added 0.02 g of 1,3-bis(4-aminophenoxy)benzene with stirring. Soon after the addition of the amine compound, the temperature of the mixture was reduced to 160° C. resulting in the reaction blend becoming somewhat viscous. After stirring the monomeric blend at 160° C. for 30 minutes, it was placed in an oven preheated to 200° C. Gelation had occurred after 2 hours at 200° C. To complete the cure, the sample was further heated in air at 260° C. for 8 hours and at 300° C. for 16 hours.
EXAMPLE XIV
Copolymer of 6F Imide-Containing Phthalonitrile (70%) and Bis[4-(3,4-dicyanophenoxy)phenyl]2,2-hexafluoropropane (30%) Cured Neat
A sample containing 0.70 g of 6F imide-containing phthalonitrile and 0.30 g of bis[4-(3,4 dicyanophenoxy)phenyl]2,2-hexafluoropropane was placed in an aluminum planchet and degassed as in Example VIII. The resulting monomeric blend was cured by heating in air at 240° C. for 16 hours (overnight), at 280° C. for 2 hours, and at 315° C. for 6 hours. Gelation occurred during the 240° C. heat treatment.
EXAMPLE XV
Copolymer of 6F Imide-Containing Phthalonitrile (60%) and Bis[4-(3,4-dicyanophenoxy)phenyl]2,2-Hexafluoropropane (40%) with 1.5% By Weight of Amine Additive
A sample containing 0.50 g of 6F imide-containing phthalonitrile and 0.40 g of bis[4-(3,4-dicyanophenoxy)phenyl]2,2-hexafluoropropane was placed in an aluminum planchet and degassed as in Example VIII. To the melt of the monomeric blend at 200° C. was added 0.15 g of APB with stirring. After stirring for 10 minutes at 200° C. , the sample was placed in an oven and cured by heating in air at 180° C. for 4 hours, at 240° C. for 4 hours and at 300° C. for 20 hours.
The new phenoxy- and imide-containing polymers exhibit outstanding thermo-oxidative stability and have potential usage for aerospace composite applications in the 300°-375° C. range. Such material could bridge the gap between currently used high temperature polymers and ceramics and metal.
During polymerization of the new phthalonitrile resins containing ether and imide linkages, no volatiles are formed, resulting in void-free components. The new resins exhibit better thermo-oxidative properties than current commercially available high temperature materials, such as PMR-15 and Thermid 600. The mechanical properties of the new resins should be improved due to a reduction in the crosslinking density.
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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Imide-containing phthalonitrile monomers are synthesized into heat resistant polymers and copolymers with aromatic ring structure incorporating imide and ether linkages. The synthesis of the high temperature thermosetting polymers and copolymers is also disclosed.
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TECHNICAL FIELD
This invention relates generally to the detection of the cell proteins of microorganisms. Of particular interest is the detection of the principal outer membrane protein of Chlamydia trachomatis. Because this protein exhibits antigenic properties common to all the Chlamydia trachomatis serotypes, its detection is useful as a diagnostic indicator.
BACKGROUND OF THE INVENTION
Immunoassay is in many cases the method of choice for detecting infection by microorganisms. As an aid to specific diagnosis, the assay must be capable of identifying a particular species of microorganism with a high degree of reliability. In most cases this requires the isolation of species specific antigens for reaction with appropriate antibodies. Typical of the type of organism yielding to such analysis is Chlamydia trachomatis, which is one of the two microorganism species of the genus Chlamydiaceae, order Chlamydiales. The other species is Chlamydia psittaci. Chlamydia trachomatis, in its some fifty various strains, are the etiologic agents for a number of human ocular and genital diseases including trachoma, inclusion conjunctivitis, lymphogranuloma venereum, "nonspecific" or nongonococcal urethritis and proctitis. C. trachomatis infection is pervasive throughout the general population. It has been estimated, for instance, that C. trachomatis is accountable for several million cases per year of nongonococcal urethritis.
Since C. trachomatis mediated disease is widespread, a reliable, simple and inexpensive test for the organism's presence is highly desirable and of great importance in order that proper treatment can be undertaken. The only serological test in current use is the microimmunofluorescence test. This test however requires that the strains of C. trachomatis be used as serological test antigen. In addition, the facilities for conducting this test are available in only a limited number of laboratories throughout the world. The test is very laborious, time consuming and difficult to perform.
Recently, U.S. Pat. No. 4,118,469, noted the preparation of an antigen of C. trachomatis useful in serological testing for lymphogranuloma venereum and nongonococcal urethritis. Such antigen was purified from C. trachomatis organisms by immunoadsorption chromatography using the monospecific antiserum as a specific ligand covalently bound in an agarose gel column. This antigen had a molecular weight of only about 160,000 daltons, and in counter-immunoelectrophoresis testing was capable of detecting antibodies from the sera of lymphogranuloma venereum patients. However, when utilized in a similar test with sera of nongonococcal urethritis patients, this antigen failed to detect antibodies. It was successful, however, in detecting antibodies in two dimensional immunoelectrophoresis testing.
In any event, however, there is still great medical interest in the isolation of species specific antigens of microorganisms, such as C. trachomatis, which are capable of detecting infection, preferably by commonly practiced antigen-antibody assay methods. It therefore is an object of the present invention to provide an improved method of isolating such species specific antigens.
BRIEF SUMMARY OF THE INVENTION
The present invention relates to a diagnostic testing method for detecting cell proteins. Although the invention is described in detail with reference to Chlamydia trachomatis, it is to be understood that the invention applies equally to cell membrane proteins of microorganisms in general.
In many microorganisms cell membrane proteins are species-specific antigens. That is, when tested against antibodies derived from all the sera types of the microorganism, the protein reacts with species specificity. The protein thus is a unique protein common to all serotypes of the microorganism, and as an antigen, provides a basis for the identification of all such serotypes.
The method of this invention for releasing cell membrane proteins from a microorganism includes the steps of: taking a test sample suspected of containing a particular microorganism, mixing the sample with a first buffer solution having a pH of from about 6.0 to about 8.0, forming a sample solution thereby, adjusting the sample pH to a value of from about 8.0 to about 12.5 using a solution of base, incubating the sample for a period of from about 5 minutes to about 30 minutes, adding a neutralizing second buffer having a pH of from about 1.0 to about 7.0 to bring the pH of the sample to a final value of from about 7.0 to about 8.0, and assaying the sample to detect the presence of antigens.
In a specific embodiment of this invention, a test method for releasing the principal outer membrane protein from C. trachomatis includes: taking a sample such as a cervical or urethral test swab, placing the sample in a first buffer solution comprising sucrose phosphate having a pH of about 7.0, mixing the swab with the buffer solution to form a sample solution, adding to the sample solution a quantity of sodium hydroxide solution having a molarity of about 0.4, thereby raising the pH of the sample solution to between about 11.0 and about 11.8, raising the temperature of the sample solution to about 100° C., incubating the sample solution for a period of about 15 minutes, cooling the sample solution to a temperature of from about 20° C. to about 30° C., reducing the pH of the cooled sample solution to between about 7.2 and about 7.8 using a neutralizing buffer of phosphate having a pH of about 6.1, and assaying the sample to detect the presence of antigens.
DETAILED DESCRIPTION OF THE INVENTION
Cell membrane proteins of many microorganisms of interest are species-specific antigens to all serotypes of those organisms. One such protein is the principal outer membrane protein of Chlamydia trachomatis. This protein comprises about 60% of the total associated outer membrane protein of C. trachomatis, and has a size or subunit molecular weight of between about 30,000 and about 44,000 daltons, with a mean molecular weight of about 39,500 daltons. Hereinafter for ease in reference, this principal outer membrane protein group will be referred to as MP 39.5, signifying "major outer membrane protein having a mean subunit molecular weight of 39,500 daltons".
The detection of a cell membrane protein is indicative of infection with that microorganism in an individual. Effective detection requires that the protein be released and/or exposed from within the infective particle of a microorganism cell. Once this is done, detection may be accomplished by a variety of assays, for example, radioimmunoassay (RIA), enzyme linked immunosorbent assay (ELISA), etc.
In accordance with the method of the present invention, disclosed is a procedure for treatment of the infective particles in cells of microorganisms, which involves the taking of a sample or specimen suspected of harboring the organism, and subjecting the sample to an alkali solution and optionally heat.
Applicant has discovered that treating cells with an alkali solution will release and/or expose cell membrane proteins from the infective particle of the cell. Applicant further has discovered that the addition of heat to the treatment process increases the efficiency by which the protein is released and/or exposed. Various assays then can be conducted to detect the presence of the protein in a sample containing the treated cells.
A general procedure in accordance with this invention is as follows: a test sample is first mixed with a buffer salt solution having a pH of from about 6.0 to about 8.0. Suitable buffers include sugar phosphate buffers, such as sucrose phosphate, and other sugar-containing buffers known to the art. Desirably, the pH of the buffer solution is from about 6.8 to about 7.2.
After the sample and the buffer salt solution have been mixed thoroughly, a quantity of alkali solution is added to the sample to raise the pH to between about 8.0 and about 12.5. Desirably the pH is from about 10.0 to about 12.0, with from about 11.0 to about 11.8 preferred. Suitable alkali solutions include those of sodium hydroxide, potassium hydroxide, trisodium phosphate, and tri(hydroxymethyl)aminomethane, with sodium hydroxide being preferred.
Once the pH has been adjusted to the desired level, the sample is incubated for a period of from about 5 to about 30 minutes. The incubation can take place at room temperature (20° C.) or at elevated temperatures up to about 105° C. Desirably, the temperature of the sample is raised to between about 90° C. and about 100° C., with about 100° C. preferred. The use of elevated temperatures during the incubation has been found to increase the efficiency by which the cell membrane protein is released and/or exposed. After the incubation period, if the sample solution has been heated, it is cooled to a temperature of from about 0° C. to about 40° C., with about 25° C. preferred. Cooling is preferably by immersion in an ice bath.
After cooling the sample, a neutralizing second buffer is added, having a pH of from about 1.0 to about 7.0, to bring the pH of the sample to a final value of from about 7.0 to about 8.0. Optimum conditions for assaying are generally obtained at these pH values, i.e., neutral to slightly alkaline. Preferably the solution has a final pH of from about 7.2 to about 7.8. Suitable neutralizing buffers include the various phosphate buffer solutions (PBS), with sucrose phosphate preferred. Other suitable buffer solutions include citric acid, hydrochloric acid and tri(hydroxymethyl)aminomethane.HCl. Following this pH adjustment, the sample is ready for assaying without further modification.
As is apparent from the preceding description, a variety of buffer salts, alkali solutions to raise the pH, and neutralizing buffers can be used in the method of this invention, along with a broad range of incubation times and temperatures. The actual reaction components and conditions can be selected so as to integrate the method of liberating MP 39.5, or other protein, into the particular detection assay of interest, e.g., enzyme immunoassay (EIA), radioimmunoassay (RIA), latex immunoassay, etc. In general, any type of known immunoassay technique can be used.
Monospecific antibodies against, for example, MP 39.5 antigen can be generated by suitable inoculation procedures with laboratory animals such as mice or rabbits. The animal generated antibodies may be utilized in assays for Chlamydial infection in other mammals. These assays may be conducted using well-known procedures for assaying the presence of bacterial antigen in the infected subject. Once a supply of monospecific antibodies has been secured from MP 39.5 antigen-inoculated laboratory animals, either direct or indirect assay procedures can be undertaken using specimens suspected of harboring Chlamydial infections.
In a direct assay procedure, monospecific antibody against the membrane protein may be covalently or noncovalently attached to a solid phase support system. As is customary in these techniques, the support system may be glass plastic or the like.
The solid phase support with attached monospecific antibody against the particular membrane protein may be incubated with a specimen prepared as outlined above. Monospecific antibody against the membrane protein antigen, which previously has been radiolabeled or conjugated with enzyme by known techniques, is then equilibrated against the support system. Any antigen present in the specimen and which has been bound to the antibody on the support system will in turn bind to the radiolabeled or enzyme conjugated antibody.
If radiolabeled antibody is used, the amount of residual radioactivity in the sample then may be determined. This value is compared to specimens that have been determined to be free of the membrane protein antigen. In the event enzyme conjugated antibody is used, a substitute specific for the enzyme is added to the solid support reaction mixture and the resultant color change is recorded spectrophotometrically. This color change is compared to samples known to be free of the membrane protein antigen. In this way, the presence of the antigen in specimens can be assayed directly.
Alternatively, indirect assay procedures can be used. Specifically, the antigens can be covalently or non-covalently bound to a suitable solid phase support system. A specimen prepared as outlined above is mixed with a known quantity of radiolabeled or enzyme conjugated antibody against the membrane protein antigen, previously secured from a laboratory animal source. The specimen extract-antibody mixture may then be incubated with the solid support system and its bound antigen.
The radioactivity of the solid support system is measured, or color development in the conjugated system is measured, and compared to specimens similarly treated as standards and which do not contain the antigen of interest.
The ability of the clinical sample suspected of containing the microorganism to inhibit the binding of the radiolabeled or enzyme conjugated antibodies to the solid support reveals the presence, or absence, of the membrane protein antigen in the clinical specimen. Any demonstrated inhibition indicates infection. Other suitable assay methods and variations will be apparent to those skilled in such assay techniques.
The following example illustrates the invention as applied to the detection of Chlamydia trachomatis MP 39.5. With little or no modification, the described procedure can be used for detection of other types of cell proteins in a variety of microorganisms.
EXAMPLE
One hundred clinical swabs were obtained and tested for the presence of Chlamydia. Reagent formulations were prepared as follows:
______________________________________A. Sodium Hydroxide (0.42 M) Solution34 ml 50% (12.5 M) NaOHq.s. to 1.0 LB. Neutralizing Bufferto 900 mL dH.sub.2 O add:NaH.sub.2 PO.sub.4.H.sub.2 O 13.8 gadjust pH to 6.10 ± 0.05 with NaOHBSA 2.0 gNaN.sub.3 1.0 gC. Standard Diluentto 800 ml dH.sub.2 O add:6.90 g NaH.sub.2 PO.sub.4.H.sub.2 O1.000 g BSA0.50 g NaN.sub.334.25 g Sucrose1.044 g K.sub.2 HPO.sub.40.544 g KH.sub.2 PO.sub.425.0 ml Heat Treated Fetal Calf Serum25 mg Streptomycin50 mg Vancomycin12,500 units Nystatinadjust pH to 7.45 ± 0.05 using 0.42 M NaOHq.s. to 1.0 LFilter through a 0.22 um filterD. Conjugate Bufferto 600 ml dH.sub.2 O add:0.532 g KH.sub.2 PO.sub.42.80 g K.sub.2 HPO.sub.40.20 g Thimerosal250. ml Heat Teated Fetal Calf Serumadjust pH to 7.4 ± 0.1q.s to 1.0 LFilter through 0.22 um filterE. Well Wash Bufferto 900 ml dH.sub.2 O add:0.532 g KH.sub.2 PO.sub.42.800 g K.sub.2 HPO.sub.41.000 g BSAadjust pH to 7.4 ± 0.1q.s. to 1.0 L with dH.sub.2 OF. Substrate Bufferto 900 ml dH.sub.2 O add:8.203 g Sodium Acetate Anyhdrousadjust pH with 1 M Citric Acid to 6.0 ± 0.1q.s. to 1.0 L with dH.sub.2 OG. Tetramethyl Benzidine (TMB) Substrateto 900 ml Dimethyl Sulfoxide (DMSO) - Spectragrade,freezing point, 18° C. add:10.0 g 3,3',5,5', tetramethyl benzidineq.s. to 1.0 L with DMSO.Store at room temperatureH. 0.5 --M Hydrogen Peroxide Solutionto 500 ml stabilized 3% H.sub.2 O.sub.2 add 500 mldH.sub.2 O and mix. I. Stopping Solution - 2 M Sulfuric Acidto 800 ml dH.sub.2 O add:carefully 111 ml Sulfuric Acid (concentrated).Cool to R.T.q.s. to 1.0 L with dH.sub.2 OJ. 2 SP Transport Mediato 900 ml dH.sub.2 O add:Sucrose 68.5 gK.sub.2 HPO.sub.4 2.088 gKH.sub.2 PO.sub.4 1.088 gFetal Calf Serum (Heat Treated) 50 mlStreptomycin 50 mgVancomycin 100 mgNystatin 25,000 unitsAdjust pH to 7.0 and q.s. to 1.0 Lfilter through sterile 0.22 um filter.______________________________________
Sample Treatment
Sample dacron swabs were cut just above cotton directly into 10×75 mm glass test tubes. Two tubes were also set up with unused swabs as blanks. 500 ul of 2SP transport medium was added to each tube and the mixtures vortexed 10-20 seconds vigorously, followed by addition of 50 ul 0.42 M NaOH to each tube. The mixtures were then vortexed 10-20 seconds vigorously, followed by incubation at 100° C. (±2° C.) for 15 minutes. The tubes were then placed in an ice bath and cooled to about 25° C., after which 500 ul of the neutralizing buffer were added. The mixtures were then vortexed 10-20 seconds vigorously. Samples were then ready for assay.
Assay Protocol--Enzyme Linked Immuo-sorbent Assay(ELISA)
Antibody coated plates were washed 3 times with wash buffer and tapped dry. One hundred microliters of standards, controls, blanks or treated samples were added to corresponding duplicate wells, followed by mixing. The controls were sample swabs known to contain elementary bodies of Chlamydia and treated as described above. A second set of controls known to contain elementary bodies were treated with 500 ul of the neutralizing buffer and 50 ul NaOH. This set of controls was untreated. The plates were then covered with plate sealers (tin foil) and incubated overnight at ambient temperature. The contents of the wells were then discarded and the plates again washed, as above. One hundred microliters of conjugate were added to each well, followed by mixing and covering with plate sealers. The plates were then incubated at 37° C. for 2 to 3 hrs. The contents of the well were again discarded and the plate washed, as above, followed by the addition of two hundred microliters of working TMB substrate solution. The working solution had the following composition:
10.0 ml Substrate buffer
100 ul Stock TMB substrate
30 ul 0.5M H 2 O
Mix solution thoroughly
The mixture was incubated 30 minutes at ambient temperature with occasional mixing. The reaction was then stopped by the addition of 50 microliters of 2M H 2 SO 4 . The plates were read against a substrate blank prepared by adding 200 microliters substrate and 50 microliters 2 M H 2 SO 4 to a strip of wells, using a 450 nanometer filter.
Calculations and Interpretation of Results
The absorbance of the blank swabs should be comparable to the 0.0ng/ml standard. Absorbances of standard wells, controls and samples were each averaged. The average 0.0ng/ml absorbance was subtracted from all averaged absorbances of standards. The average absorbance of the blank swabs was subtracted from the average absorbances of all samples and controls. The corrected average absorbance of each standard was then plotted against the concentation in ng/ml, and the recoveries determined from the plotted curves. A recovery value of ≧0.5 ng/ml was considered positive. All positive samples were repeated using both the above protocol and the confirmatory assay given below.
Confirmatory Assay Protocol for Positive Samples
Using the same Chlamydia antibody coated on the ELISA wells, solutions were prepared containing 1 mg/ml in standard buffer diluent. 10×75 mm test tubes were labeled by adding 250 ul of each digested positive sample or control to be treated. 5 ul of the antibody solution were added to all tubes, which were then mixed thoroughly by vortexing and left standing for 5 minutes. To corresponding duplicate wells were added 100 ul of the antibody treated samples. Duplicate wells from aliquots of the digested samples were also set up (not treated with Ab). Assays were then performed as described above.
Interpretation of Results from Confirmatory Testing
A positive result was assigned to samples with MP 39.5 recoveries ≧0.5 ng/ml in the wells containing the samples not treated with antibody and a significant decrease (>70% inhibition) in recovery in the sample treated with antibody. A sample assaying as positive or questionable positive when first assayed that becomes negative in the confirmatory assay was considered negative. This may result either from recovering ≦0.5 ng/ml on the repeat test (aliquots not treated with Ab) or where the aliquots treated with antibody did not show a significant decrease in recovery.
Results
Of the 100 samples tested, 62 were negative and 38 positive. Confirmation of positive results was by inhibition assay. Elementary bodies (EB) in controls were divided into treated and untreated groups to determine the efficiency of MP 39.5 liberation. Of the treated EB the average absorbance at 450 nanometers was 0.611 while the untreated EB yielded an absorbance of 0.018 at 450 nanometers.
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The invention comprises a method for detecting cell proteins of microorganisms, such as the principal outer membrane protein of Chlamydia trachomatis having a mean molecular weight of 39,500 daltons. The method includes the steps of adding a buffer salt solution to a specimen suspected of containing bacterial antigens, raising the pH of the buffered solution so produced, incubating the solution, adding a neutralizing buffer to the solution to lower the pH, and assaying the sample by conventional immunoassay techniques. Optionally the sample solution is heated prior to incubation and then cooled afterwards before adding the neutralizing buffer.
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This is a Continuation-In-Part application of co-pending application, Ser. No. 08/577,779, filed Dec. 22, 1995 pending.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to fluid delivery devices for infusion of beneficial agents into a patient. More particularly, the invention concerns a fluid delivery apparatus which includes a conformable ullage and a novel fill assembly for filling the fluid reservoir of the apparatus in the field.
DISCUSSION OF THE INVENTION
Many medicinal agents require an intravenous route for administration thus by passing the digestive system and precluding degradation by the catalytic enzymes in the digestive tract and the liver. The use of more potent medications at elevated concentrations has also increased the need for accuracy in controlling the delivery of such drugs. The delivery device, while not an active pharmacologic agent, may enhance the activity of the drug by mediating its therapeutic effectiveness. Certain classes of new pharmacologic agents possess a very narrow range of therapeutic effectiveness, for instance, too small a dose results in no effect, while too great a dose results in toxic reaction.
In the past, prolonged infusion of fluids has generally been accomplished by gravity flow methods, which typically involve the use of intravenous administration sets and the familiar bottle suspended above the patient. Such methods are cumbersome, imprecise and require bed confinement of the patient. Periodic monitoring of the apparatus by the nurse or doctor is required to detect malfunctions of the infusion apparatus.
One of the most versatile and unique fluid delivery apparatus developed in recent years is that developed by one of the present inventors and described in U.S. Pat. No. 5,205,820. The components of this novel fluid delivery apparatus generally include: a base assembly, an elastomeric membrane serving as a stored energy means, fluid flow channels for filling and delivery, flow control means, a cover, and an ullage which comprises a part of the base assembly. The ullage in these devices, that is the amount of the fluid reservoir or chamber that is not filled by fluid, is provided in the form of a semi-rigid structure having flow channels leading from the top of the structure through the base to inlet or outlet ports of the device. Since the inventions described herein represent improvements over those described in U.S. Pat. No. 5,205,820 this patent is hereby incorporated by reference as though fully set forth herein.
In the semi-rigid ullage configuration described in U.S. Pat. No. 5,205,820, wherein the ullage means is more fully described, the stored energy means of the device must be superimposed over the ullage to form the fluid-containing portion of the reservoir from which fluids are expelled at a controlled rate by the elastomeric membrane of the stored energy means tending to return to a less distended configuration in the direction toward the ullage. With these constructions, the stored energy membrane is typically used at higher extensions over a significantly large portion of the pressure-deformation curve.
For good performance, the elastomeric membrane materials selected for construction of the stored energy membrane must have good memory characteristics under conditions of high extension; good resistance to chemical and radiological degradation; and appropriate gas permeation characteristics depending upon the end application to be made of the device. Once an elastomeric membrane material is chosen that will optimally meet the desired performance requirements, there still remain certain limitations to the level of refinement of the delivery tolerances that can be achieved using the semi-rigid ullage configuration. These result primarily from the inability of the semi-rigid ullage to conform to the shape of the elastomeric membrane near the end of the delivery period. This nonconformity can lead to extended delivery rate tail-off and higher residual problems when extremely accurate delivery is required. For example, when larger volumes of fluid are to be delivered, the tail-off volume represents a smaller portion of the fluid amount delivered and therefore exhibits much less effect on the total fluid delivery profile, but in very small doses, the tail-off volume becomes a larger portion of the total volume. This sometimes places severe physical limits on the range of delivery profiles that may easily be accommodated using the semi-rigid ullage configuration.
As will be better appreciated from the discussion which follows, the apparatus of the present invention provides a unique, disposable fluid dispenser of simple but highly reliable construction that may be adapted to a wide variety of end use applications. A particularly important aspect of the improved apparatus is the incorporation of conformable ullages made of yieldable materials which uniquely conform to the shape of the stored energy membrane as the membrane distends and then returns to a less distended configuration. This novel construction, which permits the overall height of the device to be minimized, will satisfy even the most stringent delivery tolerance requirements and uniquely overcomes the limitation of materials selection. Further a plurality of subreservoirs can be associated with a single ullage thereby making it possible to incorporate a wide variety of delivery profiles within a single device.
The thrust of the present invention is to provide a novel fluid delivery apparatus that includes a conformable ullage of the character described in the preceding paragraph and also includes a unique fill assembly that can be used to controllably fill the fluid reservoir of the apparatus in the field. As will be better understood from the description which follows, the fill assembly of the present invention includes a fluid containing vial subassembly mounted within a unique adapter subassembly that functions to conveniently mate the vial subassembly with the conformable ullage type fluid delivery assembly.
In use, the adapter subassembly of the invention securely interconnects the fluid containing vial with the fluid delivery assembly so that the reservoir of the device can be controllably filled with the fluid contained within the vial assembly. After the reservoir is thus filled, the stored energy means of the fluid delivery device will cooperate with the conformable ullage to controllably expel the fluid from the device.
Another very important feature of the invention is the ability of the apparatus to provide, not only a closely controllable basal dose of medication, but also to periodically provide a controlled bolus dose of medication. This makes the apparatus most attractive for use with diabetics. For example, a normal individual who doesn't have diabetes requires energy throughout the day just to maintain a basal metabolic rate. This energy is supplied to the cells by glucose that is transported from the bloodstream to the cells by insulin. When food is consumed, the blood glucose level rises and the pancreas responds by releasing a surge of fast-acting insulin. To mimic this natural process with individual injections, the individual would have to administer minuscule amounts of fast-acting insulin every few minutes throughout the day and night.
Conventional therapy usually involves injecting, separately, or in combination, fast-acting and slower-acting insulin by syringe several times a day, often coinciding with meals. The dose must be calculated based on glucose levels present in the blood. Slower-acting insulin is usually administered in the morning and evening to take advantage of longer periods of lower level glucose uptake. Fast-acting insulin is usually injected prior to meals. If the dosage of fast-acting insulin is off, the bolus administered may lead to acute levels of either glucose or insulin resulting in complications, including unconsciousness or coma. Over time, high concentrations of glucose in the blood can also lead to a variety of chronic health problems, such as vision loss, kidney failure, heart disease, nerve damage, and amputations.
A recently completed study sponsored by the National Institutes of Health (NIH) investigated the effects of different therapeutic regimens on the health outcomes of insulin-dependent diabetics. This study revealed some distinct advantages in the adoption of certain therapeutic regimens. Intensive therapy that involved intensive blood glucose monitoring and more frequent administration of insulin by conventional means, for example, syringes, throughout the day saw dramatic decreases in the incidence of debilitating complications.
The NIH study also raises the question of practicality and patient adherence to an intensive therapy regimen. A bona fide improvement in insulin therapy management must focus on the facilitation of patient comfort and convenience as well as dosage and administration schemes. Basal rate delivery of insulin by means of a convenient and reliable delivery device over an extended period of time represents one means of improving insulin management. Basal rate delivery involves the delivery of very small volumes of fluid (for example, 0.3-3 mL. (depending on body mass) over comparatively long periods of time (18-24) hours). As will be appreciated from the discussion which follows, the apparatus of the present invention is uniquely suited to provide precise basal fluid delivery management and also a closely controlled bolus delivery of medication on an as-needed basis. For example, if the apparatus is being used for basal delivery of insulin over an extended period of time, should a bolus delivery of medication be required to manage an anticipated increase in blood sugar, such a bolus delivery can be quickly and easily accomplished using the bolus injection means of the invention, thereby eliminating the need for a direct subdermal injection at an alternate site on the individual's body.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a fluid delivery apparatus which embodies a stored energy source such as a distendable elastomeric membrane which cooperates with a base and a conformable ullage to define a fluid reservoir and one which includes a unique fill assembly for use in controllably filling the fluid reservoir. The novel fill assembly of the invention enables the fluid reservoir of the fluid delivery portion of the apparatus to be aseptically filled in the field with a wide variety of selected medicinal fluids.
Another object of the present invention is to provide an apparatus of the aforementioned character in which the fill assembly comprises a vial assembly of generally conventional construction that can be prefilled with a wide variety of medicinal fluids.
Another object of the present invention is to provide a fill assembly of the type described in the preceding paragraph in which the prefilled vial subassembly is partially received within a novel adapter subassembly that functions to operably couple the vial subassembly with the fluid delivery portion of the apparatus.
Another object of the invention is to provide viewing means for viewing the amount of fluid remaining within the prefilled vial as the fluid reservoir is being filled.
Another object of the invention is to provide an adapter subassembly of the type described in which the body of the prefilled vial is surrounded by a protective covering to maintain the vial in an aseptic condition until immediately prior to mating the subassembly with the fluid delivery portion of the apparatus.
Another object of the invention is to provide an apparatus as described in the preceding paragraphs in which the adapter subassembly includes locking means for locking the subassembly to the fluid delivery portion of the apparatus following filling of the fluid reservoir thereof.
Another object of the invention is to provide a novel fill assembly which is easy to use, is inexpensive to manufacture, and one which maintains the prefilled vial in aseptic condition until time of use.
Another object of the invention is to provide an apparatus of the character described in the preceding paragraphs which embodies a soft, pliable, conformable mass which defines an ullage within the reservoir of the device which will closely conform to the shape of the stored energy membrane geometry thereby providing a more linear delivery and effectively avoiding extended flow delivery rate tail-off with minimum residual fluid remaining in the reservoir at end of the fluid delivery period.
Another object of the invention is to provide an apparatus of the character described which includes novel fluid rate control means for precisely controlling the rate of fluid flow from the device.
Another object of the invention is to provide an apparatus which, due to its unique construction, can be manufactured inexpensively in large volume by automated machinery.
Another object of the present invention is to provide a fill assembly of the type described in which the adapter subassembly includes a plurality of outwardly extending teeth which are engageable by a manually operated drive wheel that is rotatably mounted in the fluid delivery portion of the apparatus so that the adapter subassembly and the vial subassembly can be controllably advanced into a receiving chamber provided in the fluid delivery portion of the apparatus.
Another object of the invention is to provide an apparatus of the character described in the preceding paragraph which is specially designed to permit in addition to the infusion of a basal dose the infusion of a bolus dose of medication.
Other objects of the invention are set forth in U.S. Pat. No. 5,205,820 which is incorporated herein by reference and still Further objects will become apparent from the discussion which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a generally perspective, exploded view of one form of the fluid delivery portion of the apparatus of the invention with which the adapter assembly of the invention can be operably interconnected.
FIG. 2 is a plan view of the fluid delivery portion shown in FIG. 1, partly broken away to show internal construction and shown coupled with the fill assembly of the apparatus.
FIG. 3 is a cross-sectional view taken along lines 3--3 of FIG. 2.
FIG. 4 is a cross-sectional view taken along lines 4--4 of FIG. 2.
FIG. 5 is a cross-sectional view taken along lines 5--5 of FIG. 2.
FIG. 6 is a cross-sectional view taken along lines 6--6 of FIG. 2.
FIG. 7 is a generally perspective view of one form of the adapter assembly of the present invention.
FIG. 8 is an enlarged, cross-sectional view of the adapter assembly illustrated in FIG. 7 as it appears in an assembled configuration.
FIG. 9 is a cross-sectional view similar to FIG. 8, but showing the appearance of the component parts of the invention after the plunger of the container has been telescopically moved from a first to a second position.
FIG. 10 is a cross-sectional view taken along lines 10--10 of FIG. 8.
FIG. 11 is a generally perspective exploded view of an alternate form of fill assembly of the present invention usable in providing a bolus dose of medication to a patient.
FIG. 12 is an enlarged, cross-sectional view of the fill assembly illustrated in FIG. 11 as it appears in an assembled configuration.
FIG. 13 is a cross-sectional view taken along lines 13--13 of FIG. 12.
FIG. 14 is a top plan view, partly broken away to show internal construction of an alternate form of the fluid delivery portion of the apparatus of the invention to which the fluid containing portion of the assembly shown in FIG. 12 has been operably connected.
FIG. 14A is an end view of the apparatus shown in FIG. 14.
FIG. 14B is a side view of the apparatus shown in FIG. 14.
FIG. 15 is a cross-sectional view taken along lines 15--15 of FIG. 14.
FIG. 15A is a fragmentary, cross-sectional view of the portion designated as 15A in FIG. 15.
FIG. 16 is a cross-sectional view taken along lines 16--16 of FIG. 14.
FIG. 17 is a cross-sectional view taken along lines 17--17 of FIG. 14
FIG. 17A is a generally perspective view of one form of the quick coupler assembly which forms a part of the fluid delivery means of the invention.
FIG. 18 is a fragmentary, plan view, partly in cross section, of a portion of the apparatus of this latest form of the invention illustrating in particular the advancement of the adapter assembly into the fluid delivery portion of the apparatus and showing the path of flow of the bolus dose.
FIG. 18A is a view similar to FIG. 14 but showing in greater detail the construction of the advancing means of the invention for controllably advancing the adapter assembly into the fluid delivery portion of the apparatus.
FIG. 18B is a cross-sectional view taken along lines 18B--18B of FIG. 18A.
FIG. 18C is a fragmentary top view illustrating further advancement of the adapter assembly during the delivery of the bolus dose.
FIG. 19 is a cross-sectional view taken along lines 19--19 of FIG. 14 showing one form of locking means of the invention for controlling rotation of the driving wheel of the invention.
FIG. 20 is a cross-sectional view taken along lines 20--20 of FIG. 14.
FIG. 21 is a cross-sectional view taken along lines 21--21 of FIG. 14.
FIG. 22 is a fragmentary, cross-sectional view of a portion of the apparatus showing the construction of an alternate locking means for controlling rotation of the driving wheel of the invention.
FIG. 23 is a cross-sectional view taken along lines 23--23 of FIG. 22.
FIG. 24 is a generally perspective exploded view of another form of the apparatus of the invention.
FIG. 25 is a generally perspective exploded view of the reservoir assembly of the apparatus shown in FIG. 24.
FIG. 26 is a top plan view, partly broken away to show internal construction of another form of the fluid delivery portion of the apparatus of the invention to which the fluid containing portion of the assembly shown in FIG. 12 has been operably connected.
FIG. 27 is a side view of the apparatus shown in FIG. 26.
FIG. 28 is a cross-sectional view taken along lines 28--28 of FIG. 26.
FIG. 29 is a cross-sectional view taken along lines 29--29 of FIG. 26.
FIG. 29A is an enlarged, fragmentary, cross-sectional view of the area designated as 29A in FIG. 28.
FIG. 30 is a view similar to FIG. 26 but showing in greater detail the construction of the advancing means of the invention for controllably advancing the adapter assembly into the fluid delivery portion of the apparatus.
FIG. 31 is a cross-sectional view taken along lines 31--31 of FIG. 26.
FIG. 32 is a cross-sectional, exploded view of the reservoir assembly of the apparatus shown in FIGS. 24 through 31.
FIG. 33 is a cross-sectional view of the reservoir assembly shown in FIG. 32 as it appears in an assembled, unfilled configuration.
FIG. 34 is a cross-sectional view similar to FIG. 33, but showing the reservoir assembly in a filled configuration.
FIG. 35 is a cross-sectional, exploded view of an alternate form of the reservoir assembly of the apparatus of the invention.
FIG. 36 is a cross-sectional view of the reservoir assembly shown in FIG. 35 as it appears in an assembled, unfilled configuration.
FIG. 37 is a cross-sectional view similar to FIG. 36 but showing the reservoir assembly in a filled configuration.
FIG. 38 is a cross-sectional, exploded view of still another form of the reservoir assembly of the apparatus of the invention.
FIG. 39 is a cross-sectional view of the reservoir assembly shown in FIG. 38 as it appears in an assembled, unfilled configuration.
FIG. 40 is a cross-sectional view similar to FIG. 39, but showing the reservoir assembly in a filled configuration.
FIG. 41 is a top plan view, partly broken away to show internal construction of still another form of the apparatus of the invention.
FIG. 42 is a side view of the apparatus shown in FIG. 41.
FIG. 43 is a view of the opposite side of the apparatus from that shown in FIG. 42.
FIG. 44 is a right-hand end view of the apparatus shown in FIG. 41.
FIG. 44A is a lift-hand end view of the apparatus shown in FIG. 41.
FIG. 44B is a cross-sectional view taken along lines 44B--44B of FIG. 44A.
FIG. 45 is a cross-sectional view taken along lines 45--45 of FIG. 41.
FIG. 46 is a cross-sectional view taken along lines 46--46 of FIG. 41.
FIG. 47 is an enlarged fragmentary, cross-sectional view taken along lines 47--47 of FIG. 41.
FIG. 47A is a fragmentary, cross-sectional view similar to FIG. 47 but showing the delivery line release means of the invention in a depressed configuration.
FIG. 48 is a generally perspective, exploded view of one form of the delivery line release means of the invention.
FIG. 49 is a top plan view, partly broken away to show internal construction of still another form of dual vial apparatus of the invention for accomplishing basil and bolus fluid delivery.
FIG. 49A is a fragmentary, cross-sectional view of the area designated as 49A in FIG. 49.
FIG. 50 is a cross-sectional view of a portion of the fill assembly of the apparatus for accomplishing bolus delivery.
FIG. 51 is a right-hand end view of the apparatus shown in FIG. 49.
FIG. 52 is a side view of the apparatus shown in FIG. 49.
FIG. 53 is a cross-sectional view taken along lines 53--53 of FIG. 49.
FIG. 54 is a cross-sectional view taken along lines 54--54 of FIG. 49.
FIG. 55 is a cross-sectional view taken along lines 55--55 of FIG. 49.
FIG. 56 is a cross-sectional view taken along lines 56--56 of FIG. 49.
FIG. 57 is an enlarged, fragmentary, cross-sectional view taken along lines 57--57 of FIG. 49.
FIG. 58 is an enlarged, fragmentary, cross-sectional view of the bolus-vial portion of the apparatus shown in FIG. 49.
FIG. 59 is a generally perspective view of yet another embodiment of the invention showing the vial assembly of the apparatus in the retracted position.
FIG. 60 is a generally perspective view of the embodiment of the invention shown in FIG. 59, but with the vial assembly received within the housing and the delivery line connected to the outlet port of the housing.
FIG. 61 is an end view of the apparatus shown in FIG. 60.
FIG. 62 is a side view of the apparatus shown in FIG. 60.
FIG. 63 is a view of the opposite end of the apparatus from that shown in FIG. 61 partly broken away to show internal construction.
FIG. 64 is a generally perspective exploded view of the apparatus of the invention shown in FIG. 60.
FIG. 65 is a generally perspective, exploded view of the operating means of this latest form of the invention.
FIG. 66 is a top plan view of the apparatus shown in FIG. 59, partly broken away to show internal construction.
FIG. 67 is a cross-sectional view of the area designated as 67 in FIG. 66.
FIG. 68 is a cross-sectional view taken along lines 68--68 of FIG. 66.
FIG. 69 is a cross-sectional view taken along lines 69--69 of FIG. 66.
FIG. 70 is a cross-sectional view taken along lines 70--70 of FIG. 66.
FIG. 71 is a cross-sectional view taken along lines 71--71 of FIG. 66.
FIG. 72 is an enlarged cross-sectional view of the left-hand portion of the device shown in FIG. 68 illustrating the push button assembly in an extended configuration.
FIG. 73 is a cross-sectional view taken along lines 73--73 of FIG. 72.
FIG. 74 is a cross-sectional view similar to FIG. 72, but showing the push button assembly in a depressed configuration.
FIG. 75 is a cross-sectional view taken along lines 75--75 of FIG. 66.
FIG. 76 is a cross-sectional view taken along lines 76--76 of FIG. 66.
FIG. 77 is a cross-sectional view taken along lines 77--77 of FIG. 66.
FIG. 78 is a cross-sectional view taken along lines 78--78 of FIG. 66.
DESCRIPTION OF THE INVENTION
Referring to the drawings and particularly to FIGS. 1 and 7, it is be observed that the apparatus of the invention comprises two major cooperating assemblies, namely the fluid delivery assembly 10 shown in FIG. 1 and the fill assembly 12 shown in FIG. 7. The fluid delivery assembly is similar in many respects to those disclosed in U.S. Pat. No. 5,205,820 in that it includes a base, a stored energy means which cooperates with the base to form a fluid reservoir and a cover assembly which overlays the base and encloses the stored energy means. However, unlike the fluid delivery apparatus disclosed in U.S. Pat. No. 5,205,820, which embodies semi-rigid ullages, the fluid delivery assembly of the present invention includes a novel conformable ullage, the character of which will presently be described. Also, unlike the fluid delivery devices shown in U.S. Pat. No. 5,205,820, the fluid delivery assembly of the present invention includes a uniquely configured receiving chamber 13 which is formed in the cover assembly (FIG. 1) and, in a manner presently to be described, telescopically receives a portion of the novel fill assembly of the invention.
Turning particularly to FIGS. 7 through 10, one form of the novel fill assembly portion of the apparatus is there shown and generally designated by the numeral 12. This form of the fill assembly comprises a container subassembly 14, an adapter assembly 15, and a cover assembly 17, the character of which will presently be described. Container subassembly 14 includes a body portion 16, having a fluid chamber 18 for containing an injectable fluid "F" provided with first and second open ends 20 and 22 (FIGS. 8 and 9). First open end 20 is sealably closed by closure means here provided in the form of a pierceable septum assembly 24. Septum assembly 24 is held securely in position by a clamping ring 24a. As best seen in FIGS. 8 and 9, a plunger 26 is telescopically movable within chamber 18 of container subassembly 14 from a first location shown in FIG. 8 where it is proximate first open end 22 to a second position shown in FIG. 9 where it is proximate first open end 20. The vial portion of the container subassembly 14 can be constructed of various materials such as glass and plastic.
Referring particularly to FIG. 7, it can be seen that the adapter subassembly 15 comprises a hollow housing 30 having a first open end 32 and a second closed end 34 (FIG. 9). Container subassembly 14 is telescopically receivable within open end 32 of housing 30 in the manner shown in FIG. 8 so that the housing can be moved from the first extended position shown in FIG. 8 to the second vial encapsulation position shown in FIG. 9. Forming an important part of the adapter subassembly is pusher means shown here as an elongated pusher rod 36 which functions to move plunger 26 within fluid chamber 18 from the first position shown in FIG. 8 to the second position shown in FIG. 9. In the form of the invention shown in the drawings, pusher rod 36 has a first end 36a interconnected with closure wall 34 and an opposite end 36b which engages plunger 26 and causes telescopic movement of the plunger within chamber 18 of container subassembly 14 as housing 30 is moved from the extended position into the vial encapsulating position shown in FIG. 9.
As best seen by referring to FIG. 10, the interior wall 31 of housing 30 is provided with circumferentially spaced-apart protuberances 40 which engage and center container subassembly 14 within housing 30. Due to the small surface area presented by protuberances 40, there is little frictional resistance to the sliding movement of container subassembly 14 relative to housing 30 as the housing is moved from the extended position shown in FIG. 8 into the vial encapsulating position shown in FIG. 9.
Cover subassembly 17 of the fill assembly of the present form of the invention includes a spiral wound, frangible portion 42 having a first open end 44 for telescopically receiving body portion 16 of container subassembly 14 (FIG. 8) and a second closed end 46. Portion 42 initially circumscribes a major portion of container subassembly 14 in the manner best seen in FIG. 8. An integral pull tab 42a is provided to permit the spiral wound, frangible portion to be pulled from container subassembly 14 so as to expose a substantial portion of body 16. As best seen in FIG. 7, a medicament label 50 circumscribes spiral wound portion 42 and serves to prevent accidental unwinding of the spiral portion from the container subassembly 14. However, upon pulling tab 42a, the spiral portion will unwind and, in so doing, will tear medicament label 50 so that the spiral portion 42 of the covering as well as a cylindrical portion 52 which, also comprises a part of the cover assembly, can be slipped from the container 14 so as to expose to view septum assembly 24.
As shown in FIGS. 7 and 8, the apertured end 52a of cylindrical portion 52 of subassembly 17 is provided with venting apertures 54 which are covered by a porous vent patch 56 which can be constructed from any suitable porous material that will permit air entrapped within the interior of cover subassembly 17 to be expelled to atmosphere as the subassembly is placed over container subassembly 14.
Turning once again to FIGS. 1 through 6, the fluid delivery assembly portion 10 of the apparatus can be seen to include a base subassembly 60, a cover subassembly 73 receivable over base subassembly 60, and a stored energy means, here provided in the form of a distendable membrane 66 (FIGS. 3 and 4). As best seen in FIGS. 3 and 4 the periphery of membrane 66 is sealably connected to an upraised portion 68 formed on base member 70. Base member 70 forms a part of base assembly 60 as does a clamping ring 72 which functions to clamp membrane 66 to upraised portion 68 (FIG. 1). Affixed to member 70 is a thin, planar shaped foam pad 71 having an adhesive coating provided on both its upper and lower surfaces. The adhesive coating on the upper surface of the pad enables the pad to be affixed to the lower surface of base member 70. As indicated in FIGS. 3 and 4, a peel strip 71a is connected to the bottom surface of foam pad 71 by the adhesive coating provided thereon. when the device is to be used, peel strip 71a can be stripped away from the pad so that the adhesive on the lower surface thereof can be used to releasably affix the apparatus of the invention to the patient's body.
Turning particularly to FIGS. 1 and 3, it can be seen that the cover subassembly 73 includes a cover member 74 and a medicament label 76. Cover member 73 is provided with the previously identified elongated receiving chamber 13 which is adapted to receive a portion of the fill subassembly of the invention. In a manner presently to be described the fluid container portion of the fill subassembly communicates via passageways 78, 80 and 81 with a fluid reservoir 82 which is uniquely formed between a deformable barrier member 83 and the upper surface 68a of upraised portion 68 of base member 70 (FIGS. 3 and 4). Disposed between barrier member 83 and distendable membrane 66 is the important conformable ullage means of the invention, the unique nature of which will presently be discussed.
Passageways 78 and 80 are formed within a housing 84 which is connected to cover member 73, while passageway 81 is formed within upraised portion 68 of base member 70. Housing 84 comprises a part of the cover subassembly of the invention and includes an outlet passageway 86 which communicates with a luer assembly 88 via flow control means generally designated by the numeral 90 (FIGS. 2 and 3). Plugs 85 and 87 seal access ports to the fluid passageways formed internally of housing 84, the purpose of which will presently be described. As best seen in FIG. 6, the flow control means here comprises an assemblage make up of four disc-like wafers. Wafers 94 and 96 of the assemblage comprise porous glass distribution frits while intermediate wafers 98 and 100 comprise a filter member and a rate control member respectively.
While filter member 98 can be constructed from a wide variety of materials, a material comprising polysulfone sold by Gelman Sciences under the name and style of SUPOR has proven satisfactory. Rate control member 100 is preferably constructed from a porous material such as polycarbonate material having extremely small flow apertures ablatively drilled by an excimer laser ablation process. Both the orifice size and unit distribution can be closely controlled by this process. However, a number of other materials can also be used to construct this permeable member, including metals, ceramics, cermet, plastics and glass. The rate control member can be specifically tailored to accommodate very specific delivery regimens including very low flow and intermediate flow conditions.
As best seen in FIGS. 2 and 5, housing 84 includes a generally cylindrically shaped hollow hub-like portion 102 which extends into receiving channel 13 when the housing 84 is mated with cover member 74. Formed within hub-like portion 102 is a hollow piercing cannula 104 the purpose of which will presently be described. As indicated in FIG. 2, the internal bore 104a of hollow cannula 104 comprises the previously identified fluid passageway 78, which is in fluid communication with flow passageway 80 of housing 84.
In using the apparatus of the invention, with the fill assembly in the filled configuration shown in FIG. 8, the cover subassembly is first removed from the container subassembly by pulling on pull-tab 42a. This will cause the spiral portion 42 of the cover subassembly to tear away from the container subassembly so that it can be separated from the forwardly disposed portion 52. Once the spiral wound portion 42 is removed, cylindrical portion 52 can also be removed and discarded. Removal of the cover subassembly exposes the forward portion of the container subassembly and septum 24 readies fluid containing subassembly, which comprises the adapter subassembly and the container subassembly, for interconnection with the fluid delivery assembly.
Prior to mating the adapter subassembly of the fluid containing subassembly with the fluid delivery assembly, closure plug 106 of the cover subassembly must be removed in the manner illustrated in FIG. 1. This done, the fill assembly can be telescopically inserted into receiving chamber 13 and pushed forwardly in the direction indicated by the arrow 107 in FIG. 5. A force exerted in the direction of the arrow will cause the adapter subassembly to move to the right as viewed in FIG. 5 and will cause the piercing cannula 104 to pierce septum 24. Once a fluid flow path between fluid chamber 18 of the container subassembly 16 and the fluid reservoir 82 of the fluid delivery assembly is thus created, a continued movement of the adapter subassembly will cause pusher rod 36 to move plunger 26 forwardly of chamber 18 to a position shown in FIG. 5. As plunger 26 is moved forwardly of chamber 18, the fluid "F" contained within the chamber will flow through open end 20, into passageway 104a of the piercing cannula, passageway 80 of housing 84 and then into fluid reservoir 82 via passageway 81. As the fluid under pressure flows into reservoir 82, barrier member 83 will be distended outwardly in the manner shown in FIG. 4 and will uniformly deform the conformable ullage 77 and at the same time distend the distendable membrane 66 until it reaches the position shown in FIG. 4 where it engages inner wall 74a of cover member 74. Gases contained in the volume between wall 74a and the distendable membrane 66 will be vented to atmosphere via vent passageway "V" (FIG. 3). Ring 72, which is in clamping engagement with upstanding portion 68 of base 70 functions to capture and seal t h e distendable membrane against portion 68. In a similar manner, the periphery of the barrier member 83 is sealably affixed to the upstanding portion 68a of base 70 as by adhesive or thermal bonding, so as to prevent leakage of fluid around the perimeter of the member.
It is to be understood that distendable membrane 66 can comprise a single film layer or can comprise a laminate construction made up of a number of cooperating layers. In this regard, reference should be made to columns 10 and 11 of U.S. Pat. No. 5,411,480 which patent is incorporated herein by reference, wherein the various materials that can be used to construct membrane 66 are discussed in detail. Reference should also be made to columns 11 and 12 of this patent for the various materials that can be used in the construction of the cover and base subassemblies of the fluid delivery apparatus of the present invention. Reference to FIG. 39 of the patent will show a distendable membrane of a laminate construction that can be used in the construction of the fluid delivery device of the present invention (see also columns 17 and 18 of U.S. Pat. No. 5,411,480).
Referring particularly to FIG. 1, it is to be noted that inlet means shown here as an inlet 111 formed in base 70 is provided to enable the introduction of gel which forms the conformable ullage of this form of the invention. Inlet 111 communicates with a fluid passageway 112 which, in turn, communicates with the volume defined between the under surface 66a of membrane 66 and the upper surface 83a of barrier member 83. Inlet 111 is sealably closed by a bonded plug 114.
With the construction described in the preceding paragraphs and as shown in FIGS. 3 and 4, the conformable mass 77, which comprises the ullage defining means of the invention is disposed within a chamber defined by the upper surface 68a of base member 68 and the inner surface or wall 74a of cover 74. Ullage 77 is, as shown in the drawings, in direct engagement with distendable membrane 66 which, after being distended, will tend to return to its less distended configuration. It is to be noted that the shape of the conformable ullage will continuously vary as the distendable membrane distends outwardly from the base during reservoir filling and then tends to return to its less distended configuration during fluid delivery.
While the conformable ullage, or mass 77 is here constructed from a flowable gel, the conformable ullage can also be constructed from a number of materials such as various types of foams, fluids and soft elastomers. In some instances, the conformable ullage may comprise an integral conforming mass. In other instances, such as when a gel or fluid is used as the ullage medium, an encapsulation barrier member such as member 83 must be used to encapsulate the gel or fluid and to provide an appropriate interface to the fluid contained in the reservoir.
Once reservoir 82 is filled with fluid from the container subassembly of the fill assembly, the fluid will remain in the reservoir until such time as the luer cap 89 is removed from luer assembly 88 so as to open the outlet flow path of the fluid delivery assembly. Once the outlet flow path of the assembly is opened, distendable membrane 66 will tend to return to its less distended configuration and will act upon the conformable ullage 77 and the barrier member 83 in a manner to cause fluid to flow from reservoir 82 outwardly through flow passageways 81 and 86 and then into the outlet port 120 of the device via the flow control means 90.
Referring once again to FIGS. 5 and 7, it is to be noted that hollow housing 30 includes locking means for locking the housing within receiving chamber 13 of cover 74 after the fill subassembly has been mated with the fluid delivery device. These locking means are here provided in the form of a series of forwardly and rearwardly disposed locking teeth 122 and 124 respectively. As indicated in FIG. 5, these locking teeth and constructed so that they will slide under a flexible locking tab 126, which is provided proximate the entrance of receiving chamber 13, as the adapter subassembly is urged inwardly of receiving chamber 13. However, once the adapter subassembly has reached the fully inserted position shown in FIG. 5 wherein the fluid is transferred to reservoir 82, locking tab 126 will effectively prevent removal of housing 30 of the adapter subassembly from passageway 13. With this novel construction, once reservoir 82 has been filled with the fluid contained in the container subassembly, the adapter subassembly cannot be removed from the fluid delivery device and, therefore, cannot be reused thereby preventing system adulteration.
Also forming an important aspect of the present invention is the provision of viewing means for viewing at any time the volume of fluid contained within chamber 18 of the fluid container subassembly 14. In the form of the invention shown in the drawings, this viewing means takes the form of an elongated viewing window 130 which is provided in housing 30 (FIG. 7). As indicated in FIG. 7, the body portion 16 of the container subassembly is provided with a plurality of longitudinally spaced-apart index lines, or marks 132, which can be viewed through window 130 as the container subassembly is urged forwardly of housing 30 in the manner previously described. Index lines 132 provide reference points for observing the volume of fluid remaining within the container subassembly. A protuberance 30a formed on housing 30 in cooperation with channel 30b (FIG. 5) functions to provide polarized orientation of the subassembly.
Referring next to FIGS. 11 through 23 an alternate form of apparatus of the invention is there shown. This alternate embodiment is similar in many respects to that shown in FIGS. 1 through 10, but here includes novel operating means for controllably advancing the adapter assembly into the receiving chamber of the fluid delivery portion of the apparatus to cause a controlled flow of fluid through the outlet of the apparatus.
As before, the apparatus of this latest form of the invention comprises two major cooperating assemblies, namely the fluid delivery assembly 125 shown in FIGS. 14 and 15 and the fill assembly 127 shown in FIG. 11. The fluid delivery assembly is similar in many respects to that previously described herein and to those disclosed in U.S. Pat. No. 5,205,820 in that it includes a base, a stored energy means which cooperates with the base to form a fluid reservoir and a cover assembly which overlays the base and encloses the stored energy means. Like the device shown in FIGS. 1 through 4, the fluid delivery assembly of the present invention includes novel conformable ullage means and a uniquely configured receiving chamber 130 which is formed between the base and cover assemblies (FIGS. 14A and 16). In a manner presently to be described, chamber 130 telescopically receives a portion of the fill assembly of the invention to permit controlled filling of the reservoir of the device and also to administer bolus doses of medication as may be required.
Turning particularly to FIGS. 11 and 12, the alternate form of the fill assembly portion of the apparatus is there shown and can be seen to comprise a container subassembly 133, an adapter subassembly 135, and a cover assembly 137, the character of which will presently be described. Container subassembly 133 includes a body portion 139, having a fluid chamber 141 for containing an injectable fluid "F". Chamber 141 is provided with first and second open ends 143 and 145 (FIG. 12). First open end 143 is sealably closed by closure means here provided in the form of a pierceable septum assembly 147. Septum assembly 147 is held securely in position by a clamping ring 147a. As best seen in FIGS. 11 and 12, a plunger 129 is telescopically movable within chamber 141 of container subassembly 133 between first and second locations.
As best seen in FIGS. 11 and 12, adapter subassembly 135 comprises a hollow housing 153 having a first open end 155 and a second closed end 157 (FIG. 12). Container subassembly 133 is telescopically receivable within open end 155 of housing 153 in the manner shown in FIG. 12 so that the housing can be moved from a first extended position to a second vial encapsulation position. As was earlier the case, the adapter subassembly includes pusher means shown here as an elongated pusher rod 159 (see also FIG. 13), which functions to move plunger 129 within the fluid chamber 141 of the container subassembly. Pusher rod 159 has a first end 159a interconnected with closure wall 157 and an opposite end 159b which engages plunger 129 and causes telescopic movement of the plunger within chamber 141.
Cover subassembly 137 of the fill assembly of this latest form of the invention comprises a generally cylindrically shaped cover 161 having a first open end 161a for telescopically receiving body portion 139 of container subassembly 133 (FIG. 11) and a second end 161b which is closed by a filter means shown here as a porous filter member or vent 163. Cover 161 initially circumscribes a major portion of the container subassembly, but is removable therefrom expose a substantial portion of body 139 of the container. As best seen in FIG. 11, a medicament label 164 circumscribes the fill assembly to provide a septic closure and also serves to prevent accidental separation of the cover 161 from the adapter subassembly 135. However, upon tearing the medicament label the cover assembly can be easily slipped from the container so as to expose to view septum assembly 147. Filter member 163 can be constructed from any suitable porous material that will permit air entrapped within the interior of cover subassembly 137 to be expelled to atmosphere as the subassembly is placed over container subassembly 133.
Turning particularly to FIGS. 14, 14A, 14B and 15 the fluid delivery assembly portion of the apparatus can be seen to include a base subassembly 167, a cover subassembly 169 which is receivable over base subassembly 167, and a stored energy means, here provided in the form of a distendable membrane 171 (FIGS. 15 and 15A). As best seen in FIG. 15A the periphery 171a of membrane 171 is sealably connected to a base member 173 which forms a part of base assembly 167. Distendable membrane 171, as well as a barrier member 175, the purpose of which will presently be described, are affixed to base member 173 by adhesive bonding, by sonic bonding, or by other suitable means in the manner shown in FIG. 15A. By way of example a reservoir defining member 176, which forms a part of base assembly 167, includes a protuberance, or energy director 177 which functions to cut membrane 171 and to direct sonic energy when member 176 is sonically bonded to base member 173 in the manner shown in FIG. 15A.
Affixed to the lower surfaces of the base assembly is a thin, planar shaped foam pad 177 (FIG. 15) having an adhesive coating provided on both its upper and lower surfaces. The adhesive coating on the upper surface of the pad enables the pad to be affixed to the lower surface of base assembly. As before, a peel strip 177a is connected to the bottom surface of foam pad 177 by the adhesive coating provided thereon. When the device is to be used, peel strip 177a can be stripped away from the pad so that the adhesive on the lower surface thereof can be used to releasably affix the apparatus of the invention to the patient's body.
An extremely important feature of the apparatus of the latest embodiment of the invention is the provision of the previously mentioned bolus delivery means for delivering bolus doses of medication to the patient. The bolus delivery means here includes operating means for accomplishing closely controlled fluid flow through the outlet of the fluid delivery assembly. As best seen in FIGS. 14, 15, 17, and 18A, the operating means of the present form of the invention comprises driving means, including a drive wheel 180, which is rotatably carried by base member 173 and driven means, which here comprises a plurality of longitudinally spaced-apart engagement members, or teeth like portions, 182 provided on hollow housing 153. As shown in FIG. 18A, drive wheel 180 along with a first screw gear 184 are mounted on a first shaft 186 which is carried by spaced-apart shaft supports 188 formed on base member 173 (FIG. 17). Screw gear 184 along with drive wheel 180 are driven by a second screw gear 190, which along with a finger engaging or thumb wheel 192, is mounted on a second shaft 194 which is rotatably supported by supports 195 in the manner best seen in FIG. 15. Thumb wheel 192 is engageable by the user through an aperture provided in the cover through which a portion of the thumb wheel extends.
Also carried by second shaft 194 is an anti-reverse rotation gear 196, an indexing disc 198, and an indicator disc 200, the purpose of each of which will presently be described. For example, illustrated in FIG. 21, the anti-reverse rotation gear 196 comprises a toothed member which cooperates with a tooth engaging clip 202 mounted on base member 173 to permit rotation of the gear only in one direction.
Indexing disc 198 and indicator disc 200 both comprise a part of the control means of the invention for controlling bolus flow outwardly of the device as a result of the controlled advancement of hollow housing 153 within receiving chamber 130. The details of operation of the control means will be later discussed in connection with an overall discussion of the operation of the apparatus of this latest form of the invention.
Turning now particularly to FIGS. 14, 16 and 18, the previously identified elongated receiving chamber 130, which is adapted to receive a portion of the fill subassembly of the invention, can be seen to be strategically located between base 173 and cover member 206 of cover assembly 169. In a manner presently to be described, the fluid chamber 141 of container 139 of the fill subassembly communicates via passageways 208, 210 and 212 with the fluid reservoir 214 of the fluid delivery assembly 125, which reservoir is uniquely formed between a deformable barrier member 175 and the upper surface 173a of base member 173 (see also FIGS. 15, 16 and 17). Disposed between barrier member 175 and distendable membrane 171 is the important conformable ullage means of this latest form of the invention which is similar in many respects to that described in connection with FIGS. 1 through 4.
Passageway 208, which is formed within a hollow piercing cannula 220 communicates with passageway 210 which, in turn, communicates with passageway 212 that terminates in inlet 222 of reservoir 214. Passageway 210 also communicates via a porous plug 226 with a continuation passageway 210a which, in turn, communicates with the outlet port 228 of the fluid delivery assembly 125. Outlet port 228 includes a tapered wall portion 228a which sealably receives the tapered portion of a novel quick connect coupler which comprises a part of the fluid delivery means of the invention. As best seen in FIG. 18, continuation passageway 210a also communicates with an outlet passageway 230 which leads to the outlet port 232 of fluid reservoir 214.
In using the apparatus of the invention, with the fill assembly in the filled configuration shown in FIG. 12, the cover subassembly 137 is first removed from the container subassembly to expose the forward portion of the container subassembly and septum 147. This step readies the adapter subassembly for interconnection with the fluid delivery assembly 125 of the invention in the manner shown in FIG. 14.
In mating the adapter subassembly with the fluid delivery assembly, the container subassembly is first telescopically inserted into receiving chamber 130 of the fluid delivery assembly and the adapter subassembly is then pushed forwardly to the position indicated by the solid lines in FIG. 14. The pushing force exerted on the adapter subassembly will cause piercing cannula 220, which extends into receiving chamber 130, to pierce septum 147. Once a fluid flow path between fluid chamber 141 of the container subassembly and the fluid reservoir 214 of the fluid delivery assembly is thus created, a continued movement of the adapter subassembly toward the solid line position shown in FIG. 14 will cause pusher rod 159 to move plunger 129 forwardly of chamber 130 to the position shown in the solid lines of FIG. 14. As plunger 129 is moved forwardly of chamber 141, a portion of the fluid "F" contained within the chamber will flow into passageway 208 of the piercing cannula, into passageway 210, into passageway 212 and then into fluid reservoir 214 via inlet 222. As the fluid under pressure flows into reservoir 214, barrier member 175 will be distended outwardly in the manner shown in FIG. 15 and will uniformly deform the conformable ullage means, shown here as a gel 235. As gel 235 moves outwardly from surface 173a and into a toroidal chamber 176b formed in member 176, the distendable membrane 171 will distend outwardly until it reaches the position shown in FIG. 15 where it engages inner wall 176a of reservoir defining member 176. Gases contained in the volume between wall 176a and distendable membrane 171 will be vented to atmosphere via vent passageway "V" (FIG. 15). In the manner best seen in FIG. 15A, reservoir forming member 176 which is bonded to base 173 functions to capture and seal the distendable membrane about its periphery. In a similar manner, the periphery of the barrier member 175 is sealably affixed to base 173 as by adhesive or thermal bonding, so as to prevent leakage of fluid around the periphery of the member.
It is to be understood that distendable membrane 171 can comprise a single film layer or can comprise a laminate construction made up of a number of cooperating layers. In this regard, reference should be made to columns 10 and 11 of U.S. Pat. No. 5,411,480 which patent is incorporated herein by reference, wherein the various materials that can be used to construct membrane 171 are discussed in detail. Reference should also be made to columns 11 and 12 of this patent for the various materials that can be used in the construction of the cover and base subassemblies of the fluid delivery apparatus of the present invention. Reference to FIG. 39 of the patent will show a distendable membrane of a laminate construction that can be used in the construction of the fluid delivery device of the present invention (see also columns 17 and 18 of U.S. Pat. No. 5,411,480).
With the construction described in the preceding paragraphs and as shown in FIGS. 15, 15A, and 16, the conformable mass or gel, which comprises the ullage defining means of this form of the invention is disposed within a chamber defined by the upper surface of the barrier membrane 175 and the inner surfaces of base 173 and reservoir defining member 176. As indicated in the drawings, the ullage or gel 235 is in direct contact with distendable membrane 171 which, after being distended, will tend to return to its less distended configuration. It is to be noted that the shape of the conformable ullage will continuously vary as the distendable membrane distends outwardly from the base during reservoir filling and then as it tends to return to its less distended configuration during the basal fluid delivery step.
While the conformable ullage, or mass 235 is here constructed from a flowable gel, the conformable ullage can also be constructed from a number of materials such as various types of foams, fluids and soft elastomers.
Once reservoir 214 is filled with fluid from the container subassembly of the fill assembly, the fluid will remain in the reservoir until such time as the outlet flow path of the fluid delivery assembly is opened to fluid flow. Once the outlet flow path of the assembly is opened, distendable membrane 171 will tend to return to its less distended configuration and will act upon the conformable ullage 235 and the barrier member 175 in a manner to cause fluid to flow from reservoir 214 outwardly through a reservoir outlet 232 via an appropriate rate control means. The fluid will next flow into passageways 230 and 210a and finally outwardly of the device via the fluid delivery means of the apparatus, the character of which will presently be described. It is to be noted that due to impedance offered by porous member 226 to upstream flow, the fluid will tend to flow downstream toward the fluid delivery means via passageway 210a.
Considering next the extremely important bolus delivery means of the apparatus of the invention, this novel means enables the patient to receive both a selected basal dose of medication from reservoir 214 and also a bolus dose of medication from chamber 141 of container 139. Typically insulin is maintained from the manufacturer prepackaged in 1.0 ml vials. A portion of this quantity can be used for basal delivery, a portion for incremental bolus delivery on demand, and the balance, if any, for residual within the device. For example, if insulin is being delivered at a basal rate, the patient may receive from reservoir 214 up to one-half milliliter over a period of 24 hours. Additionally should the patient determine that the blood sugar level is unduly high, a bolus injection of a predetermined volume can quickly and easily be simultaneously accomplished through use of the controlled incremental bolus injection means of the invention thereby supplementing as necessary the basal dose being delivered from the fluid reservoir 214.
Referring particularly to FIG. 18A, after the adapter subassembly 135 has been pushed forwardly into the position there shown, reservoir 214 has been filled and further forward movement of the subassembly within receiving chamber 130 is temporarily blocked by the engagement of tooth 182a with drive wheel 180. It should also be noted that as the adapter subassembly 135 is pushed forwardly of chamber 130 in the direction of the arrow 240 of FIG. 18A, a angularly inclined valve member engaging surface 242 which is provided on housing 153, engages the valve means of the invention which functions to control fluid flow toward fluid inlet 222 of reservoir 214. As best seen by also referring to FIG. 18, this novel valve means here comprises an inwardly extending, slidably movable operating arm 244 having at one end a sloping camming surface 246 which is engageable by surface 242 of housing 153. Provided at the opposite end of arm 244 is a port closure member 248 which functions to close port 222 when arm 244 is in its inward-most position (FIG. 18C). With this construction as surface 242 engages camming surface 246, member 244 will be moved relative to base 173 from an inlet port open position shown in FIG. 14 to the inlet closing position shown in FIGS. 17 and 18A wherein port closure member 248 blocks and substantially seals against further fluid flow into fluid reservoir 214 via inlet 222. When reservoir inlet 222 is closed by the valve means, it is apparent that the fluid "F1" remaining in fluid chamber 141 is precluded from flowing into the fluid reservoir 214 via inlet 222. However, it is important to note that upon further advancement of the adapter subassembly, the fluid F1, which remains in fluid chamber 141, is free to flow into cannula passageway 220, into passageway 210 through impedance 226 and then into passageway 210a of the fluid delivery assembly.
To cause the fluid F1 which remains within chamber 141 to flow outwardly of the device, the finger engaging means, or thumb wheel 192, of the operating means of the invention must be rotated. As previously discussed, rotation of thumb wheel 192 will impart rotation to first screw gear 184 and also to drive wheel 180. Turning to FIG. 18C, it is to be observed that rotation of drive wheel 180 of the drive means relative to adapter housing 153 will cause the controlled advancement of the adapter assembly from the position shown in FIG. 18A to the position shown in FIG. 18C. As the adapter assembly 153 is thus moved incrementally inwardly of receiving chamber 130, plunger 129 will move incrementally forwardly of chamber 141 causing a portion of the fluid F1 contained within chamber 141 to be expelled outwardly of the chamber via cannula passageway 208 and delivery passageways 210 and 210a.
Another important feature of the fluid delivery assembly of the invention is control means for controlling the rotation of drive wheel 180 and thereby controlling the bolus volume flowing from the apparatus via outlet port 228. This novel control means, which forms a part of the operating means of the invention, includes the previously identified indexing disc 198. Also forming a part of the control means of the invention is safety interlocking means for controlling rotation of indexing disc 198. This interlocking means here comprises a locking shaft 250 having first and second ends 250a and 250b. Shaft 250 is connected to base 173 proximate its first end 250a in a manner such that end 250b extends outwardly of the cover through an opening 252 provided therein. Provided intermediate ends 250a and 250b of shaft 250, is an engagement arm 254 which, as best seen in FIG. 19, includes an end portion 254a, which is biased toward and receivable in a selected one of four circumferentially spaced slots 256 provided in control wheel 198, which slots are here spaced apart 90 degrees. With this construction so long as end portion 254a is received within one of the slots 256, rotation of indexing disc 198 as well as rotation of the finger engaging or thumb wheel 192 of the apparatus is effectively prevented. However, upon transverse movement of control shaft 250 from its normal inwardly biased locking position into the unlocked position shown in FIG. 18, a rotation of disc 198 and wheel 192 is possible.
As wheel 192 is rotated, wheel 190 will engage and rotate screw gear 184 which, in turn, will rotate drive wheel 180 causing an incrementally controlled, telescopically inward movement of adapter assembly 153 into receiving chamber 130. With this unique construction, it is apparent that the volume of the fluid F1 remaining within the chamber can be likewise precisely incrementally displaced from the chamber by closely controlling the extent of rotation of control wheel 198. By way of example for insulin use, if chamber 141 is sized to contain 1.0 milliliter of liquid and if 0.5 milliliter of liquid is required to fill reservoir 214, then the liquid or fluid F1 remaining in chamber 141 after filling reservoir 214 is approximately 0.5 milliliter of insulin. Similarly, if teeth 182 and drive wheel 180 are designed so that one full rotation of drive wheel 180 will advance adapter assembly 153 a distance to cause plunger 129 to move one-fourth of the remaining distance of chamber 141 that is filled with fluid F1, then four complete revolutions of drive wheel 180 would result in the delivery to the fluid delivery means of the invention of the all of the fluid F1 remaining in chamber 141. It follows, therefore, that one rotation of drive wheel 180 would deliver one quarter of the volume or one tenth (0.1) milliliter of the fluid remaining within chamber 141. Accordingly, rotation of wheel 198 through one-quarter of a turn, that is the distance between adjacent notches 256, would result in the delivery of one-quarter of one tenth (0.025) milliliter of liquid per quarter rotation of wheel 198. With this unique arrangement, it is apparent that as desired by the user, a volume of between one quarter of one tenth milliliter (0.025 ml) and 0.4 milliliters of liquid can be delivered from the apparatus by the bolus delivery means depending upon the extent to which the control wheel 198 is permitted to be rotated. For example, if locking shaft 250 is maintained in the open, unlocked position shown in FIG. 18A, a continued rotation of thumb wheel 192 will result in free rotation of the control wheel 198 and will permit complete dispensing of the fluid F1 from the device. Conversely, if locking shaft 250 is manipulated to only remove end portion 254a from the slot in which it resides and then is released, wheel 198 will turn one quarter of a turn and then will be blocked from further rotation as end portion 254 moves into the next succeeding notch 256 due to the urging of biasing shaft 250. This one quarter of a turn of wheel 198 will then result in the delivery of precisely one quarter of one tenth milliliter of liquid from the fluid F1 remaining in chamber 141. It is to be understood that chamber 141 of container 139 can be of various volumes and that the control wheel can be notched in a manner to permit delivery of any desired increment of the liquid volume of chamber 141.
As previously mentioned, the beneficial agent flowing through outlet 228 will be received within the fluid delivery means, which includes tapered outlet cavity 228a. Cavity 228a is adapted to receive a quick connect delivery fitting 260 that also comprises a part of the delivery means of the invention. As shown in FIG. 17A, fitting 260 includes a tapered inboard end portion 260a and a body portion 260b. A central bore 262 extends through portions 260a and 260b and communicates at its outboard end with a cannula 264 which also forms a part of the delivery means of the invention for delivering fluids from the device. When fitting 260 is seated within outlet 228 (FIG. 18), the inboard end of bore 262 communicates with continuation passageway 210a which, in turn, communicates with passageway 210 and cannula 220.
In order to lock quick connect delivery fitting 260 in the fluid delivery position, locking means shown here as resiliently deformable locking tabs 266 are provided on the body portion 260b of fitting 260. Tabs 266 lockably engage a locking surface 268 provided on a connector receiving ring 270 form on front housing 269 (FIG. 18). Upon pushing inwardly on fitting 260, tabs 266 will yieldably deform inwardly so that tapered portion 260a of the fitting can be introduced into outlet 228. As the fitting seats within the chamber, the resiliently deformable locking tabs will spring outwardly and engage locking surface 268 in a manner to lockably interconnect the delivery means with the front housing 269. With the quick connect fitting thus in place, the beneficial agent contained within reservoir 214 can flow outwardly of the apparatus through delivery cannula 264.
Turning next to FIGS. 22 and 23, an alternate form of control means for controlling the rotation of drive wheel 180 is there shown. This novel control means, which forms a part of the operating means of the invention, includes the previously described indexing disc 198 and also includes a slightly different form of safety interlocking means for controlling rotation of indexing disc 198. This locking means here comprises a push button assembly 270 having a finger engaging hub 272 which extends outwardly of the cover through an opening 274 provided therein. Push button, or hub, 272 is connected to an inwardly extending shaft 276 to which an engagement arm 278 is connected. Shaft 276 and push button 272 are biased outwardly by a coil spring 280 which is contained between a flange 272a connected to button 272 and a support 282 having an aperture 282a adapted to slidably receive shaft 276.
As best seen in FIG. 23, end 278a of engagement arm 278 is receivable in a selected one of four circumferentially spaced slots 256 provided in control wheel 198, which slots are here spaced apart by 90 degrees. With this construction so long as end 278a of arm 278 is received within one of the slots 256, rotation of indexing disc 198 as well as rotation of the finger engaging or thumb wheel 192 of the apparatus is effectively prevented. However, upon pushing button 272 and shaft 276 inwardly from their normal outwardly biased locking position into the unlocking position shown by the phantom lines in FIG. 22, rotation of disc 198 and wheel 192 is possible.
As before, as wheel 192 is rotated, wheel 190 will engage and rotate screw gear 184 which, in turn, will rotate drive wheel 180 causing a telescopically inward movement of adapter assembly 153 into receiving chamber 130. With this alternate construction, it is apparent that, as before, the volume of the fluid F1 remaining within the chamber can be precisely dispensed from the chamber by closely controlling the extent of rotation of control wheel 198.
Turning next to FIGS. 24 and 25, another form of the apparatus of the invention is there shown. This form of the apparatus is very similar to that shown in FIGS. 14 through 23 and like numbers are used to identify like components. The major difference between this latest embodiment and that previously described resides in the fact that, unlike the embodiment shown in FIGS. 14 through 23, this latest form of the apparatus of the invention is not designed to be interconnected directly with the patient's body, but rather comprises a free standing unit which can be carried by the patient or attached to the patient's clothing. Therefore, the casing or housing of the device does not include an adhesive coated foam pad 177 of the character shown in FIGS. 15, 16, and 17.
Referring particularly to FIGS. 24, 25, and 28, the fluid delivery assembly portion of the apparatus can be seen to include a base subassembly 277, a cover subassembly 279, including forward portion 279b which is receivable over base subassembly 277, and a fluid reservoir defining means, or reservoir unit, which includes a stored energy means, here provided in the form of a distendable membrane 281 (FIGS. 25, 28, and 29A). Distendable membrane 281, in cooperation with a barrier member 283, functions to encapsulate the ullage defining means of this form of the invention, which means also comprises a part of the reservoir defining means. The details of the reservoir defining means will be described more fully in the paragraphs which follow.
This latest embodiment of the invention also includes a novel bolus delivery means of the character previously described for delivering bolus doses of medication to the patient. As before, the bolus delivery means includes operating means for accomplishing closely controlled fluid flow through the outlet of the fluid delivery assembly. The operating means of the present form of the invention is virtually identical in construction and operation to that described in connection with FIGS. 14, 15, 17, and 18A and like numbers have been used in FIGS. 24 through 29 to identify like components of this important bolus delivery means.
Turning particularly to FIGS. 24, 26, 27, and 29, an elongated receiving chamber 285 is provided between base subassembly 277 and cover assembly 279 and is adapted to receive a portion of the fill subassembly 127 of the invention. Once again, the fill assembly of the invention is identical to that shown in FIGS. 11 and 12 and includes a container subassembly 133, an adapter subassembly 135, and a cover assembly 137 (FIG. 11) all of which are of the same construction and operate in the same manner as previously described herein. As best seen in FIG. 26 and 28, the fluid chamber 141 of container 139 of the fill subassembly communicates via passageways 288, 290 and 292 with the reservoir defining means which functions to define fluid reservoir 294 of the fluid delivery assembly. Reservoir is uniquely formed between deformable barrier member 283 and the upper surface 296a of a base member 296 which forms a part of base subassembly 277. As previously mentioned, disposed between barrier member 283 and distendable membrane 281 is the important conformable ullage means of this latest form of the invention which is similar in many respects to that described in connection with FIGS. 14 through 17.
Passageway 288, which is formed within hollow piercing cannula 220 communicates with passageway 290 which, in turn, communicates with passageway 292 that terminates in inlet 300 of reservoir 294 (FIG. 29). Passageway 290 also communicates via a porous plug 226 with a continuation passageway 290a which, in turn, communicates with the outlet port 302 of the fluid delivery assembly. Outlet port 302 includes a tapered wall portion 228a which sealably receives the tapered portion of the quick connect coupler assembly 260 (FIG. 17A) which comprises a part of the fluid delivery means of the invention, which means is also identical to that previously described. As best seen in FIG. 26, continuation passageway 290a also communicates with an outlet passageway 304 which leads to the outlet port 306 of fluid reservoir 294.
In using the apparatus of the invention, with the reservoir defining means mated with the base and with the fill assembly in the filled configuration shown in FIG. 12, the cover subassembly 137 is first removed from the container subassembly to expose the forward portion of the container subassembly and septum 147. This step readies the adapter subassembly for interconnection with the fluid delivery assembly of the invention in the manner shown in FIG. 26.
In mating the adapter subassembly with the fluid delivery assembly, the container subassembly is first telescopically inserted into receiving chamber 285 of the fluid delivery assembly and the adapter subassembly is then pushed forwardly to the position shown in FIG. 30. The pushing force exerted on the adapter subassembly will cause piercing cannula 288, which extends into receiving chamber 285, to pierce septum 147. Once a fluid flow path between fluid chamber 141 of the container subassembly and the fluid reservoir 294 of the fluid delivery assembly is thus created, a continued movement of the adapter subassembly toward the position shown in FIG. 30 will cause pusher rod 159 to move plunger 129 forwardly of chamber 141 to the position shown in FIG. 30. As plunger 129 is moved forwardly of chamber 141, a portion of the fluid "F" contained within the chamber will flow into passageway 288 of the piercing cannula, into passageway 290, into passageway 292 and then into fluid reservoir 294 via inlet 300. As the fluid under pressure flows into reservoir 294, barrier member 283 will be distended outwardly in the manner shown in FIG. 28 and will uniformly deform the conformable ullage means, shown here as a fluid medium 309. As medium 309 moves outwardly from surface 296a, the distendable membrane 281 will distend outwardly until it reaches the position shown in FIGS. 28 and 29. Gases contained in the volume between the cover subassembly and distendable membrane 281 will be vented to atmosphere via vent passageway "V" (FIG. 28).
In addition to distendable membrane 281, barrier member 283 and the conformable ullage, the reservoir defining means also includes an outer membrane retaining ring 312 and an internal clamping ring 314. In the manner best seen in FIGS. 25, 28, 32, 33, and 34, the outer membrane retaining ring 312 and the internal clamping ring 314 cooperate to capture and seal both the distendable membrane and the barrier membrane about their periphery. More particularly, the periphery 283a of barrier member 283 is sealed relative to base 296, by clamping ring 314, while the periphery 281a of distendable membrane 281 is sealably clamped between an internal shoulder 312a formed on outer membrane retaining ring 312 and the top surface 314a of internal clamping ring 314. It is to be noted that base 296 is provided with an annular groove 315 which receives the lower peripheral portion of ring 312 so that the entire reservoir assembly shown in FIG. 25 can be assembled as a unit 313 with base 296. For this purpose, base 296 is provided with an upstanding, generally ring-shaped reservoir assembly receiving ring portion 296b, which defines surface 296a that forms the base of reservoir 294.
As before, distendable membrane 281 can take the various forms described in U.S. Pat. No. 5,411,480 which is incorporated herein by reference.
With the construction described in the preceding paragraphs, when the reservoir defining means, shown here as reservoir assembly 313, is assembled with base 296 in the manner shown in FIGS. 28 and 29, the conformable mass or ullage fluid, which comprises the ullage defining means of this form of the invention is disposed within a chamber defined by the lower surface of the distendable membrane 281, the upper surface of the barrier membrane 283 and the inner surface of clamping ring 314. As indicated in the drawings, the ullage or fluid medium 309 is in direct contact with distendable membrane 281 which, after being distended in the manner shown in FIG. 28, will tend to return to its less distended configuration. It is to be noted that the shape of the conformable ullage will continuously vary as the distendable membrane distends outwardly from the base during reservoir filling and then as it tends to return to its less distended configuration during the basal fluid delivery step.
Once reservoir 294 is filled with fluid from the container subassembly of the fill assembly, the fluid will remain in the reservoir until such time as the outlet flow path of the fluid delivery assembly is opened to fluid flow. Once the outlet flow path of the assembly is opened, distendable membrane 281 will tend to return to its less distended configuration and will act upon the conformable ullage 309 and the barrier member 283 in a manner to cause fluid to flow from reservoir 294 outwardly through reservoir outlet 306. The fluid will next flow into passageways 304 and 290a and finally outwardly of the device via the fluid delivery means of the apparatus. As before, the impedance offered by porous member 226 to upstream flow, the fluid will tend to flow downstream toward the fluid delivery means via passageway 290a.
The important bolus delivery means of the apparatus of this latest form of the invention, enables the patient to receive both a selected basal dose of medication from reservoir 294 and also a bolus dose of medication from chamber 141 of container 139.
Referring particularly to FIG. 30, after the adapter subassembly 135 has been pushed forwardly into the position there shown, reservoir 294 has been filled and further forward movement of the adapter subassembly within receiving chamber 285 is temporarily blocked by the engagement of tooth 182a with drive wheel 180. It should also be noted that as the adapter subassembly 135 is pushed forwardly of chamber 285, a angularly inclined valve member engaging surface 242 which is provided on housing 153, engages the valve means of the invention which functions to control fluid flow toward fluid inlet 300 of reservoir 294. This novel valve means is identical in operation and construction to that previously described in connection with FIGS. 14 through 23 and comprises an inwardly extending, slidably movable operating arm 244 having at one end a sloping camming surface 246 which is engageable by surface 242 of housing 153. Provided at the opposite end of arm 244 is a port closure member 248 which functions to close port 300 when arm 244 is in its inward-most position (FIG. 30). With this construction as surface 242 engages camming surface 246, member 244 will be moved relative to base 296 from an inlet port open position to the inlet closing position shown in FIG. 30 wherein port closure member 248 blocks further fluid flow into fluid reservoir 294.
To cause the fluid F1 which remains within chamber 141 to flow outwardly of the device, the operating means of the invention is operated in the manner previously described by rotation of the thumb wheel 192, a portion of which extends through an access opening 279a provided in cover 279 (FIG. 24). Rotation of thumb wheel 192 and the concomitant rotation of drive wheel 180 of the drive means relative to adapter housing 153 will cause the controlled advancement of the adapter assembly within receiving chamber 285. As the adapter assembly 153 moves incrementally inwardly of receiving chamber 285, plunger 129 will simultaneously move forwardly of chamber 141 causing a portion of the fluid F1 contained within chamber 141 to be expelled outwardly of the chamber via cannula passageway 288 and then into passageways 290 and 290a.
Another important feature of the fluid delivery assembly of this latest form of the invention is control means for controlling the rotation of drive wheel 180 and thereby controlling the bolus volume flowing from the apparatus via outlet port 302. This control means, which forms a part of the operating means of the invention, is identical in construction and operation to that previously described herein.
When the adapter subassembly is fully inserted into receiving chamber 285, locking means of the character previously described, which includes locking teeth 122 and locking tab 126, will lock the adapter subassembly to the base assembly thereby preventing system adulteration (FIG. 27).
Turning next to FIGS. 32 through 34, an alternate form of reservoir assembly is there shown and generally designated by the numeral 320. This reservoir assembly or unit is similar to that shown in FIGS. 24 through 31 save that the unit mates with the base of the fluid delivery device in a slightly different manner. More particularly, as best seen in FIG. 33, the base 322 of the fluid delivery device of this alternate form of the invention is provided with a generally flat surface 322a which is provided with a circular groove 322b that is adapted to closely receive a skirt portion 324a of a strategically shaped retainer member 324 (see also FIG. 32). With this construction, a distendable membrane 325 is sealably clamped between an internal shoulder 324b formed on member 324 and the upper surface 326a of a clamping ring 326.
A barrier membrane 327 extends over the upper surface 322a of base 322 and is clamped there against about its periphery by clamping ring 326 in the manner shown in FIGS. 33 and 34. Disposed between distendable membrane 325 and barrier membrane 327 is a conformable ullage defining means here shown as a gel 328.
In operation, as the fluid under pressure flows into the reservoir 329, which is defined by the lower surface of the barrier membrane 327 and the upper surface 322a of the base 322, barrier member 327 will be distended outwardly from the position shown in FIG. 33 to the position shown in FIG. 34 and will uniformly deform the conformable ullage means or gel 328. As the gel moves outwardly from the upper surface of the base, the distendable membrane 325 will distend outwardly until it reaches the position shown in FIG. 34. As before, the entire reservoir assembly 320 can be assembled as a unit with base 322 and will function with the base assembly in the same manner as previously described.
Referring now to FIGS. 35, 36, and 37, still another form of reservoir assembly of the invention is there shown and generally designated by the numeral 330. This reservoir assembly or unit also mates with the base of the fluid delivery device in a slightly different manner. More particularly, as best seen in FIG. 35, the base 331 of the fluid delivery device of this alternate form of the invention is provided with an upstanding, generally ring-shaped protuberance 332 over which a skirt portion 333a of a strategically shaped cover member 333 is closely received (FIG. 36). With this construction, a distendable membrane 334 is sealably clamped between an internal shoulder 333b formed on the cover member and the upper surface 332a of ring-shaped protuberance 332.
A barrier membrane 335 extends over the upper surface 331a of base 331 and is suitably affixed thereto about its periphery as by adhesive or thermal bonding in the manner shown in FIGS. 36 and 37. Disposed between distendable membrane 334 and barrier membrane 335 is a conformable ullage defining means here shown as a soft elastomer 336.
In operation, as the fluid under pressure flows into the reservoir 337, which is defined by the lower surface of the barrier membrane and the upper surface 331a of the base 331, barrier member 335 will be distended outwardly from the position shown in FIG. 36 to the position shown in FIG. 37 and will uniformly deform the conformable ullage means or elastomer 336. as elastomer 336 moves outwardly from the upper surface of the base, the distendable membrane 334 will distend outwardly until it reaches the position shown in FIG. 37 and engages the inner surfaces 333c. Gases contained in the volume between the cover subassembly and distendable membrane 334 will be vented to atmosphere via vent passageway "V" (FIG. 35). As before, the entire reservoir assembly can be assembled as a unit with base 331 and will function in the same manner as previously described.
Turning next to FIGS. 38 through 39, still another form of reservoir assembly is there shown and generally designated by the numeral 338. This reservoir assembly or unit is somewhat similar to that shown in FIG. 15 save that the base 336 of the fluid delivery device of this alternate form of the invention includes a bottom housing 339 (FIG. 38) which includes circular shaped central portion 339a which is circumscribed by a groove 340. Sealably receivable within groove 340 is a skirt portion 342a which is provided on a strategically shaped membrane retaining ring 342 (FIG. 38). With this construction, a barrier membrane 344 is sealably clamped between retaining ring 342 and the upper surface 348 of ring-shaped groove 340 formed in housing 339.
A distendable membrane 346 extends over retaining ring 342 and is sealably connected thereto about its periphery 346a by a downwardly depending skirt 350a formed on a cover member 350 (FIGS. 39 and 40). Disposed between the distendable membrane 346 and barrier membrane 344 is a conformable ullage defining means here shown as a deformable foam 353.
In operation, as the fluid under pressure flows into the reservoir 354, which is defined by the lower surface of the barrier membrane and the upper surface of housing 339, barrier member 344 will be distended outwardly from the position shown in FIG. 39 to the position shown in FIG. 40 and will uniformly deform the conformable ullage means or foam 353. As foam 353 moves outwardly from the upper surface of housing 339, the distendable membrane 346 will distend outwardly until it reaches the position shown in FIG. 40 where it engages the inner wall 350b of cover 350. Gases contained in the volume between the cover and distendable membrane 346 will be vented to atmosphere via vent passageway "V". As before, the entire reservoir assembly can be assembled as a unit and will function in the same manner as previously described.
It is apparent from the foregoing discussion and from an analysis of FIGS. 24 and 32 through 40, that a number of different types of reservoir assemblies can be operably coupled with a base assembly 277 of the character shown in FIG. 25. More particularly, by selecting the proper reservoir assembly, the user can choose from various types of ullage means and ullage configurations and reservoir volumes as may be best suited for the end use of the fluid delivery device. For example, the ullage means can comprise a gel, a cellular mass, an elastomer, a flowable substance or the like.
Turning next to FIGS. 41 through 48, yet another form of the apparatus of the invention is there shown. This form of the apparatus is very similar to that shown in FIGS. 24 through 40 and like numbers are used to identify like components. The major difference between this latest embodiment and that previously described resides in the sculptured appearance of the device and in the manner by which the delivery line is connected to and released from the housing. Like the apparatus shown in FIGS. 24 through 40, this latest form of the apparatus of the invention is also designed to be a free standing unit which can be carried by the patient or attached to the patient's clothing.
Referring particularly to FIGS. 41, 45, and 46, the fluid delivery assembly portion of the apparatus can be seen to include a base subassembly 360, including an end portion 360a (FIG. 47), a cover subassembly 362, which is receivable over base subassembly 360, and a stored energy means, here provided in the form of a distendable membrane 364 (FIG. 45) As before, distendable membrane 364, in cooperation with a barrier member 366, functions to encapsulate the ullage defining means of this form of the invention for providing a conformable ullage, which is of the character previously described.
Like the earlier described embodiments of the invention, this latest embodiment also includes a novel bolus delivery means of the general character previously described for delivering bolus doses of medication to the patient. As before, the bolus delivery means includes operating means for accomplishing closely controlled fluid flow through the outlet of the fluid delivery assembly. The operating means of this latest form of the invention is virtually identical in construction and operation to that previously described herein save for the addition of an idler gear assembly 367 (FIG. 41) and like numbers have been used in FIGS. 41 through 48 to identify like components of this important bolus delivery means.
As best seen in FIG. 41 an elongated receiving chamber 368 is provided between base subassembly 360 and cover assembly 362 and is adapted to receive a portion of the fill subassembly of the invention. Once again, the fill assembly of the invention is identical to that shown in FIGS. 11 and 12 and includes a container subassembly 133, an adapter subassembly 135, and a cover assembly of the character shown in FIG. 11 and designated by the numeral 137 all of which are of the same construction and operate in the same manner as previously described herein. As indicated in FIG. 41, the fluid chamber 141 of container 139 of the fill subassembly communicates via passageways 370, 372 and 374 with the fluid reservoir 376 (FIG. 45) of the fluid delivery assembly, which reservoir is uniquely formed between deformable barrier member 366 and the upper surface 378a of a base member 378 which forms a part of base subassembly 360. As previously mentioned, disposed between barrier member 366 and distendable membrane 364 is the important conformable ullage means of this latest form of the invention which is similar in many respects to that described in connection with FIGS. 14 through 17.
Passageway 370, which is formed within hollow piercing cannula 220 communicates with passageway 372 which, in turn, communicates with passageway 374 that terminates in inlet 380 of reservoir 376. Passageway 372 also communicates via a porous plug 382 with a continuation passageway 372a which, in turn, communicates with the outlet port 384 of the fluid delivery assembly. As before, outlet port 384 includes a tapered wall portion 384a which sealably receives the tapered portion of the quick connect coupler assembly 260 which is of the same general Character previously described and which comprises a part of the fluid delivery means of the invention. As best seen in FIG. 41, continuation passageway 372a also communicates with an outlet passageway 388 which leads to the outlet port 389 of fluid reservoir 376.
Save for the design of the control means and the manner of interconnection and release of the delivery line assembly, the apparatus operates in substantially the same manner as the apparatus shown in FIGS. 24 through 40. More specifically, the control means here comprises the previously identified indexing disc 198 and also includes a safety interlocking means for controlling rotation of indexing disc 198. This interlocking means here comprises a push-button, activated locking means which comprises an engagement arm 391 which, as best seen in FIG. 41, includes an end portion 391a, which is receivable in a selected one of four circumferentially spaced slots 256 provided in control wheel 198, which slots are here spaced apart 90 degrees. With this construction, so long as end portion 391a of the engagement arm is received within one of the slots 256, rotation of indexing disc 198 as well as rotation of the finger engaging or thumb wheel 192 of the apparatus is effectively prevented. However, upon inward movement of the push button 393 and the engagement arm connected thereto against the urging of a biasing means, here provided as a coil spring 395, rotation of disc 198 and wheel 192 is made possible (see FIG. 41).
As before, as wheel 192 is rotated, wheel 190 will engage and rotate an idler gear 367 and the screw gear 184 which, in turn, will rotate drive wheel 180 causing an incrementally controlled, telescopically inward movement of adapter assembly 153 into receiving chamber 368. In this way the volume of the fluid F1 remaining within chamber 141 can be precisely incrementally displaced from the chamber by closely controlling the extent of rotation of control wheel 198.
In operating the device of this latest form of the invention, the fluid containing portion of the fill assembly is mated with the device in the manner previously described and the reservoir is filled in the manner previously described. Similarly, bolus injections are accomplished using the operating means, which means is substantially identical in construction and operation to that shown in FIGS. 24 through 40.
Turning particularly to FIGS. 47 and 48, the novel delivery line interconnection and release means of the invention for interconnecting the delivery assembly shown in FIG. 17A to the apparatus housing is there shown. This means here comprises a push button subassembly 390 which includes a head portion 390a; and a pair of yieldably deformable legs 392. A part of head portion 390a extends through an aperture 394a formed in cover 394 of the cover subassembly 362 in the manner shown in FIG. 47 so that the depending legs 392 engage the ramp sides 396a and 396b of a ramp unit 396 (FIG. 48). Ramp unit 396 is connected to the base subassembly as shown in FIG. 47 at a location proximate outlet port 384. Each of the legs 392 of the push button subassembly is provided with a locking protuberance 398 which is constructed and arranged to lockably engage the shoulder 397 of the delivery fitting (FIG. 44B) when the push button subassembly is in the upward, at-rest position shown in FIG. 47. It is apparent that a downward force of head portion 390 as shown in FIG. 47A will cause legs 392 to move downwardly along ramp sides 396a and 396b causing protuberance 398 to spread apart a sufficient distance to permit withdrawal of delivery fitting. As best seen in FIG. 44A, the fitting 399 is similar to fitting 260 save for the fact that shoulder 397 replaces wings 266 of the earlier described fitting assembly.
Turning next to FIGS. 49 through 58, another embodiment of the invention is there shown. This form of the apparatus is somewhat similar to that shown in FIGS. 24 through 40 and like numbers are used to identify like components. The major difference between this latest embodiment and those previously described herein resides in the fact that the apparatus here comprises dual fill assemblies, one for use in filling the reservoir of the fluid delivery assembly and the other for providing a bolus dose of beneficial agent as may be required. Like the apparatus shown in FIGS. 24 through 40, this latest form of the apparatus of the invention is a free standing unit which can be carried by the patient or, for example, attached to the patient's belt.
Referring particularly to FIGS. 49, 53, and 54, the fluid delivery assembly portion of the apparatus can be seen to include a base subassembly 400, a cover subassembly 402, which is receivable over base subassembly 400, and a stored energy means, here provided in the form of a distendable membrane 404 (FIG. 53). Distendable membrane 404, in cooperation with a barrier member 406, functions to encapsulate the ullage defining means of this form of the invention for providing a conformable ullage, which is of the character previously described.
Unlike the earlier described embodiments of the invention, this latest embodiment includes a first fill assembly for filling the reservoir of the device and a separate bolus delivery means for delivering bolus doses of medication to the patient. The bolus delivery means here comprises a second fill assembly and, as before, includes operating means for accomplishing closely controlled fluid flow through the outlet of the fluid delivery assembly via a second hollow cannula 408 which extends into a second receiving chamber 410 formed in the delivery assembly portion of the apparatus. The operating means of this latest form of the invention is very similar in construction and operation to that described in connection with the apparatus shown in FIGS. 24 through 40.
More particularly, as best seen in FIG. 49, the operating means here comprises driving means, including a drive wheel 412, which is rotatably carried by base member 414 of the base assembly of this latest embodiment. The operating means further includes driven means, which here comprises a plurality of longitudinally spaced-apart, teeth-like portions 417 provided on a second hollow housing 417a of the second fill assembly which is of identical construction to that shown in FIG. 11 save that the second hollow housing is provided with additional teeth-like portions. Drive wheel 412 along with a first screw gear 419 are mounted on a first shaft 421 which is carried by spaced-apart shaft supports formed on base member 414. Screw gear 419 along with drive wheel 412 are driven by a second screw gear 423, which along with a finger engaging or thumb wheel 424, is mounted on a second shaft 427 which is rotatably supported by supports similar to supports 195 of the character shown in FIG. 15 (see also FIG. 54).
Also carried by second shaft 427 is an anti-reverse rotation gear 428, an indexing disc 430, and an indicator disc 434 (FIG. 49) which performs the same function respectively as anti-rotation gear 196, indexing disc 198 and indicator disc 200. Indexing disc 430 and indicator disc 432 comprise a part of the control means of this latest form of the invention for controlling bolus flow outwardly of the device as a result of the controlled advancement of hollow housing 417a within receiving chamber 410 (FIG. 49).
Second receiving chamber 410, which is adapted to receive a portion of the second fill subassembly of the invention, is strategically located between base 400 and a cover member 402 which comprises a part of the cover subassembly. When the components are in the position shown in FIG. 49, the fluid chamber 141a of a second container 139a of the second fill subassembly communicates via second hollow cannula 408 with the fluid delivery means of the apparatus, which includes the outlet port 411 of the apparatus.
As best seen in FIG. 49 another elongated receiving chamber 414 is provided between base subassembly 400 and cover subassembly 402 and is adapted to receive a portion of the first fill subassembly of the invention which is identical to the previously described fill subassembly 127 (see FIG. 11). First fill assembly includes a container subassembly 133, an adapter subassembly 135, and a cover assembly 137 all of which are of the same construction and operate in the same manner as previously described herein. As indicated in FIG. 49, the fluid chamber 141 of first container 139 of the first fill subassembly communicates via passageways 416, 418 and 420 with a fluid reservoir 422 of the fluid delivery assembly. Reservoir 422 is formed between deformable barrier member 406 and the upper surface 414a of a base member 414 which forms a part of base subassembly 400 (FIGS. 53 and 54). In the manner previously discussed the important conformable ullage means of the invention is disposed between barrier member 406 and distendable membrane 404.
Passageway 416, which is formed within a first hollow piercing cannula 426 communicates with passageway 418 which, in turn, communicates with passageway 420 that terminates in an inlet 428 of reservoir 422. Passageway 418 also communicates with a continuation passageway 418a via reservoir 422 which, in turn, communicates with the outlet port 410 of the fluid delivery assembly. As before, outlet port 411 includes a tapered wall portion 411a which sealably receives the tapered portion of the quick connect coupler assembly 399 which is of the character previously described and which comprises a part of the fluid delivery means of the invention. As best seen in FIG. 49, a continuation passageway 418a also communicates with an outlet passageway 430 which leads to the outlet port 432 of fluid reservoir 422. Interconnection and release of the delivery line assembly shown in FIG. 17A is accomplished in the exact manner as was the case with the apparatus shown in FIGS. 24 and 40.
In using the apparatus of this latest form of the invention, with the first fill assembly in the filled configuration shown in FIG. 12, the cover subassembly 137 is first removed from the container subassembly to expose the forward portion of the container subassembly and first septum 147. This step readies the first adapter subassembly for interconnection with the fluid delivery assembly of the invention in the manner shown in FIG. 49.
In mating the first adapter subassembly with the fluid delivery assembly, the first container subassembly is first telescopically inserted into first receiving chamber 414 of the subassembly of the invention which is identical to the previously described fill subassembly 127 (see FIG. 11). First fill assembly includes a container subassembly 133, an adapter subassembly 135, and a cover assembly 137 all of which are of the same construction and operate in the same manner as previously described herein. As indicated in FIG. 49, the fluid chamber 141 of first container 139 of the first fill subassembly communicates via passageways 416, 418 and 420 with a fluid reservoir 422 of the fluid delivery assembly. Reservoir 422 is formed between deformable barrier member 406 and the upper surface 414a of a base member 414 which forms a part of base subassembly 400 (FIGS. 53 and 54). In the manner previously discussed the important conformable ullage means of the invention is disposed between barrier member 406 and distendable membrane 404.
Passageway 416, which is formed within a first hollow piercing cannula 426 communicates with passageway 418 which, in turn, communicates with passageway 420 that terminates in an inlet 428 of reservoir 422. Passageway 418 also communicates with a continuation passageway 418a via reservoir 422 which, in turn, communicates with the outlet port 410 of the fluid delivery assembly. As before, outlet port 410 includes a tapered wall portion 410a which sealably receives the tapered portion of the quick connect coupler assembly 260 which is of the character previously described and which comprises a part of the fluid delivery means of the invention. As best seen in FIG. 49, a continuation passageway 418a also communicates with an outlet passageway 430 which leads to the outlet port 432 of fluid reservoir 422. Interconnection and release of the delivery line assembly shown in FIG. 17A is accomplished in the exact manner as was the case with the apparatus shown in FIGS. 24 and 40.
In operating this latest form of the invention, with the first fill assembly in the filled configuration shown in FIG. 12, and with the cover subassembly 137 removed the assembly is inserted into receiving chamber 414 and pushed forwardly to the position shown in FIG. 49. The pushing force exerted on the first adapter subassembly will cause first piercing cannula 426, which extends into receiving chamber 414, to pierce first septum 147. Once a fluid flow path between fluid chamber 141 of the container subassembly and the fluid reservoir 422 of the fluid delivery assembly is thus created, a continued movement of the first adapter subassembly toward the position shown in FIG. 49 will cause pusher rod 159 to move plunger 129 forwardly of chamber 141. As plunger 129 is moved forwardly of chamber 141, substantially all of the fluid "F" contained within the chamber will flow into passageway 416 of the first piercing cannula, into passageway 418, into passageway 420 and then into fluid reservoir 422 via inlet 428. As the fluid under pressure flows into reservoir 422, barrier member 406 will be distended outwardly in the manner shown in FIG. 53 and will uniformly deform the conformable ullage means, shown here as a gel 235. As gel 235 moves outwardly from surface 414a, the distendable membrane 404 will distend outwardly until it reaches the position shown in FIG. 53. Gases contained in the volume between the cover subassembly 402 and distendable membrane 404 will be vented to atmosphere via vent passageway "V" (FIG. 54). As before, a retainer ring 312 functions to capture and seal the distendable membrane about its periphery. In a similar manner, the periphery of the barrier member 406 is sealably clamped to base 414 by clamping ring 314 so as to prevent leakage of fluid around the periphery of the member (see also FIG. 34).
With the construction described in the preceding paragraphs, the conformable gel, which comprises the ullage defining means of this form of the invention is disposed within a chamber defined by the upper surface of the barrier membrane 406 and the inner surfaces of base 414 and retaining ring 312. As indicated in FIG. 53 and 54, the ullage or gel 235 is in direct contact with distendable membrane 404 which, after being distended, will tend to return to its less distended configuration. It is to be noted that the shape of the conformable ullage will continuously vary as the distendable membrane distends outwardly from the base during reservoir filling and then as it tends to return to its less distended configuration during the basal fluid delivery step.
Once reservoir 422 is filled with fluid from the first container subassembly of the first fill assembly, designated in FIG. 49 as 433, the fluid will remain in the reservoir until such time as the outlet flow path of the fluid delivery assembly is opened to fluid flow. Once the outlet flow path of the assembly is opened, distendable membrane 404 will tend to return to its less distended configuration and will act upon the conformable ullage and the barrier member 406 in a manner to cause fluid to flow from reservoir 422 outwardly through a reservoir outlet 432. The fluid will next flow into passageway 418a via a rate control element 419 and finally outwardly of the device via the fluid delivery means of the apparatus.
Considering once again the bolus delivery means of the apparatus of this latest form of the invention, this novel means enables the patient to receive a selected basal dose of medication from reservoir 422 and also a bolus dose of medication from chamber 141a of second container 135a of the portion of the fill assembly designated as 435 in FIG. 49.
More particularly, after the second adapter subassembly 135a of the second fill assembly portion has been mated with the fluid delivery assembly by insertion of the vial assembly and adapter assembly into receiving chamber 410 (FIG. 58), bolus delivery can be accomplished by operation of the operating means of the invention and, more particularly, by rotation of the finger engaging means, or thumb wheel 424, of the operating means of the invention. As previously discussed, rotation of thumb wheel 424 will impart rotation to first screw gear 419 and also to drive wheel 412. Rotation of drive wheel 412 of the drive means relative to adapter housing 418a will cause the controlled advancement of the second adapter assembly into receiving chamber 410. As the second adapter assembly is thus moved incrementally inwardly of receiving chamber 410, second plunger 129a will move incrementally forwardly of second chamber 141a causing the fluid F3 contained within chamber 141a to be expelled outwardly of the chamber via second hollow cannula 408 and delivery passageway 418a.
An important feature of the fluid delivery assembly of this latest form of the invention comprises the previously mentioned control means for controlling the rotation of drive wheel 412 and thereby controlling the bolus volume flowing from portion 435 of the apparatus via outlet port 418a. This novel control means, which forms a part of the operating means of the invention, is similar to that described in connection with the embodiment shown in FIG. 14 and includes the previously identified indicator disk 200 and an indexing disc 430. Also forming a part of the control means of this latest form of the invention is safety interlocking means for controlling rotation of indexing disc 430. This interlocking means here comprises a push button assembly 431 which includes a locking member 431a (FIG. 56). The control means operates in substantially the same manner as previously discussed herein and the details of operation will not be here repeated.
Turning to FIGS. 59 through 78, still another form of the apparatus of the invention is there shown. This form of the apparatus is similar to that shown in FIGS. 41 through 48 and like numbers are used to identify like components. This embodiment, like that of FIGS. 41 through 48, has a sleek sculptured appearance and is also designed to be a free standing unit which can be carried by the patient or attached to the patient's clothing.
Referring particularly to FIGS. 59 through 64, the fluid delivery assembly portion of the apparatus can be seen to include a base subassembly 450, a cover subassembly 452, which is receivable over base subassembly 450, and a stored energy means, here provided in the form of a distendable membrane 454 (FIGS. 64 and 70). As before, distendable membrane 454, in cooperation with a barrier member 456, functions to encapsulate the ullage defining means of this form of the invention for providing a conformable ullage, which is of the character previously described.
Like the earlier described embodiments of the invention, this latest embodiment also includes a novel bolus delivery means of the general character previously described for delivering bolus doses of medication to the patient. As before, the bolus delivery means includes operating means for accomplishing closely controlled fluid flow through the outlet of the fluid delivery assembly. As best seen in FIGS. 64 and 65, the operating means of this latest form of the invention is similar in construction and operation to that previously described and like numbers have been used in FIGS. 59 through 78 to identify like components.
An elongated receiving chamber 458 is provided between base subassembly 450 and cover subassembly 452 and is adapted to receive a portion of the fill subassembly of the invention. Once again, the fill assembly of the invention is similar to that shown in FIGS. 11 and 12 and includes a container subassembly 459, an adapter subassembly 461, and a cover subassembly 137 all of which operate in a similar manner to that previously described herein. As indicated in FIG. 66, the fluid chamber 463 of container 465 of the fill subassembly communicates via passageways 468, 470 and 472 with the fluid reservoir 474 (FIG. 70) of the fluid delivery assembly, which reservoir is uniquely formed between deformable barrier member 456 and the upper surface 476a of a base member 476 which forms a part of base subassembly 450. As previously mentioned, disposed between barrier member 456 and distendable membrane 454 is the important conformable ullage means of this latest form of the invention which is similar in many respects to that described in connection with FIGS. 49 through 58.
Passageway 468, which is formed within a hollow piercing cannula 478 communicates with passageway 470 which, in turn, communicates, via a porous member 471, with passageway 472 that terminates in inlet 480 of reservoir 474. As shown in FIGS. 66 and 70, reservoir 474 also communicates with an outlet port 492 via a passageway 482 and a rate control means shown here as a second porous wafer 484. Porous members 471 and 484 can be constructed of various porous sintered materials such as ceramics, stainless steel and other metals having fluid flow passages of a desired size to closely control the flow of fluid therethrough. As before, outlet port 486, which comprises the outlet of the fluid delivery assembly, includes a tapered wall portion 488 which sealably receives the tapered portion 490a of a quick connect coupler assembly 490 which is of the same general character previously described and which comprises a part of the fluid delivery means of the invention. As best seen in FIG. 66, passageway 482 communicates with the outlet port 492 of fluid reservoir 474.
As best seen in FIGS. 64 and 65, the control means of this latest form of the invention comprises an indexing disc 496 and also includes a safety interlocking means for controlling rotation of indexing disc 496. This interlocking means here comprises a push-button, activated locking means, or locking assembly 497, which includes an engagement arm 498 which, as best seen in FIG. 78, includes an end portion 498a, which is receivable in a selected one of four circumferentially spaced slots 500 provided in disc 496, which slots are here spaced apart 90 degrees. With this construction, so long as end portion 498a of the engagement arm is received within one of the slots 500, rotation of indexing disc 496 as well as rotation of the finger engaging or thumb wheel 502 of the apparatus is effectively prevented. However, upon inward movement of the push button 497a of the locking assembly and the engagement arm connected thereto against the urging of a biasing means, here provided as a coil spring 504, rotation of disc 496 and wheel 502 is made possible.
As thumb wheel 502 is rotated, it will engage and rotate wheel 506, which will engage and rotate a gear 508. In turn, gear 508 will rotate a drive wheel 510, which cooperates with teeth 526 provided on adapter assembly 461 to cause an incrementally controlled, telescopically inward movement of the adapter assembly into receiving chamber 458. In this way the volume of the fluid remaining within chamber 463 can be precisely, incrementally displaced and thereby dispensed from the chamber by closely controlling the amount of rotation of the control or thumb wheel 502 which is carried by a shaft 512. Shaft 512 also carries means for preventing reverse rotation to wheel 514, which includes a tooth engaging, resiliently deformable locking clip 516 that is mounted on base assembly 450 (see FIGS. 64, 65 and 78). When clip 516 is in the position shown in FIG. 78, rotation of wheel 514 in a counter-clockwise, reverse direction is prevented, but rotation in the opposite direction is permitted.
In operating the device of this latest form of the invention, the fluid containing portion of the fill assembly is mated with the device in the manner previously described. More particularly, after the adapter subassembly has been inserted into receiving chamber 458, it is pushed forwardly in the direction of the arrow "P" of FIG. 66. The pushing force exerted on the adapter subassembly will cause piercing cannula 478, which extends into receiving chamber 458, to pierce septum 147 in the manner shown in FIG. 71. Once a fluid flow path between fluid chamber 463 of the container subassembly and the fluid reservoir 474 of the fluid delivery assembly is thus created, a continued inward movement of the adapter subassembly will cause pusher rod 159 to move plunger 129 forwardly of chamber 463 to the position shown in FIG. 66. As plunger 129 is moved forwardly of chamber 463, a portion of the fluid contained within the chamber will flow into passageway 468 of the piercing cannula, into passageway 470, into passageway 472 via porous member 471 and then into fluid reservoir 474 via inlet 480.
As the fluid under pressure flows into reservoir 474, the stored energy means will be energized. More particularly, barrier member 456 will be distended outwardly in the manner shown in FIG. 75 and will uniformly deform the conformable ullage means, shown here as a gel 521. As gel 521 moves outwardly from surface 476a, the distendable membrane 454 will distend outwardly until it reaches the position shown in FIG. 70. Gases contained in the volume between the cover and the distendable membrane will be vented to atmosphere via vent passageway "V" (FIG. 70). In the manner previously described, clamping ring 312 functions to capture and seal the distendable membrane about its periphery. In a similar manner, the periphery of the barrier member 456 is sealably affixed to base 476 as by adhesive or thermal bonding, so as to prevent leakage of fluid around the periphery of the member.
Once reservoir 474 is filled with fluid from a portion of the container subassembly of the fill assembly, valve means member 248 will extend and thereby close inlet 480 in the manner previously described. With the inlet closed, the fluid will remain in the reservoir until such time as the outlet flow path of the fluid delivery assembly is opened to fluid flow. Once the outlet flow path of the assembly is opened, the stored energy means or distendable membrane 454 will tend to return to its less energized configuration and will act upon the conformable ullage 521 and the barrier member 456 in a manner to cause fluid to flow from reservoir 474 outwardly through a reservoir outlet 492. The fluid will next flow into passageways 482 then into passageway 524, via porous member 484 and finally outwardly of the device via the fluid delivery means of the apparatus.
Considering next the extremely important bolus delivery means of the apparatus of this latest form of the invention, this novel means enables the patient to receive both a selected basal dose of medication from reservoir 474 and also a bolus dose of medication from chamber 463 of container 459. Referring particularly to FIG. 66, after the adapter subassembly 461 has been pushed forwardly into the position there shown and reservoir 474 has been filled, further forward movement of the subassembly within receiving chamber 458 is temporarily blocked by the engagement with drive wheel 510 of tooth 526a of the plurality of spaced-apart adapter teeth 526 provided on adapter assembly 466. As before, as the adapter subassembly 461 is pushed forwardly of chamber 458 in the direction of the arrow "P" of FIG. 66, an angularly inclined valve member engaging surface 242 engages the valve means of the invention which functions to control fluid flow toward fluid inlet 480 of reservoir 474. This novel valve means here comprises the previously described, inwardly extending, slidably movable operating arm 244 which has at one end a sloping camming surface 246 which is engageable by surface 242 of adapter assembly 461. Provided at the opposite end of arm 244 is a port closure member 248 which, in the manner previously described, functions to close port 480 when arm 244 is in its inward-most position. When reservoir inlet 480 is closed by the valve means, it is apparent that the fluid remaining in fluid chamber 463 is blocked from flowing into the fluid reservoir via inlet 480. However, it is important to note that upon further advancement of the adapter subassembly, the fluid that remains in fluid chamber 463, is free to flow into cannula passageway 468, into passageway 470 and then into passageway 524 via a stub connector passageway 523 (FIG. 66). In this way a controlled basal delivery of fluid to the patient can be appropriately accomplished.
To cause the fluid which remains within chamber 463 (FIG. 71) to flow outwardly of the device, the finger engaging means, or thumb wheel 502, of the operating means of the invention must be rotated. The operating means, which includes the previously discussed control means and indicator or dosing disk 200, is similar in construction and operation to that previously described herein. As before, rotation of thumb wheel 502, which extends through an opening 452c provided in cover 452, will impart rotation to gears 506 and 508 and also to drive wheel 510. Rotation of drive wheel 510 of the drive means will cause the controlled advancement of the adapter assembly from the position shown in FIG. 59 to the position shown in FIG. 60. As the adapter assembly 461 is thus moved incrementally inwardly of receiving chamber 458, plunger 129 will move incrementally forwardly of chamber 463 causing a selected bolus increment of the fluid remaining within chamber 463 to be expelled outwardly of the chamber via cannula passageway 468 and delivery passageways 470, 523 and 524. As indicated in FIG. 59, cover 452 is provided with viewing means for viewing the amount of fluid remaining in chamber 463. This viewing means here comprises a viewing window 527 having longitudinally spaced indicator lines 527a. Locking means, shown here as a locking clip 529 (FIG. 67) engages each tooth 122a of the row of locking teeth 122 provided on adapter subassembly 461 and, functions to irreversibly lock the adapter subassembly in each incrementally inserted position.
Turning particularly to FIGS. 72, 73, and 74, the novel delivery line interconnection and release means of the invention for interconnecting the delivery assembly shown in FIG. 59 to the apparatus housing is there shown. This means here comprises a push button subassembly 530 which includes a head portion 530a and a pair of yieldably deformable legs 530b. A part of head portion 530a extends through an aperture 532a formed in one end a cover assembly 532 which interconnects the top and bottom assemblies 450 and 452 in the manner illustrated in FIG. 64. With this construction, depending legs 530b of the subassembly engage the ramp sides 534a and 534b of a ramp unit 534 (FIG. 72). Ramp unit 534, which forms a part of the base subassembly 450, which is also shown in FIG. 72, is disposed at a location proximate outlet port 486. Each of the legs 530a and 530b of the push button subassembly is provided with a locking protuberance 531 which is constructed and arranged to lockably engage the shoulder 490c of the delivery fitting (FIG. 72) when the push button subassembly is in the upward, at-rest position shown in FIG. 72. It is apparent that a downward force exerted on head portion 530a will, as shown in FIG. 74, cause legs 530b to move downwardly along the ramp sides causing protuberances 531 to spread apart a sufficient distance to permit withdrawal of delivery fitting.
Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.
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A fluid delivery apparatus for continuous basal infusion, together with controlled bolus infusion of injectable medicaments, which embodies a stored energy source such as distendable elastomeric membrane which cooperates with a base and a conformable ullage to define a fluid reservoir and one which includes a unique fill assembly for use in controllably filling the fluid reservoir. The novel fill assembly of the invention enables the fluid reservoir of the fluid delivery portion of the apparatus to be aseptically filled in the field with a wide variety of selected medicinal fluids.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to road spikes with improved characteristics and methods of deployment, and in particular to road spikes made of long fiber reinforced thermoplastics that, when deployed, are geometrically positioned to puncture or disable a tire.
2. Description of the Related Art
The problems associated with stopping the escape of a vehicle in police and military applications are well known. It is desirable to cause rapid stopping of the vehicle by puncturing one or more tires, and then allowing the air to escape without plugging the hole. There are numerous devices that are designed to accomplish these tasks. Some examples are:
U.S. Pat. No. 2,346,713 to Walker is titled Caltrop. This patent teaches a body having four hollow arms equally spaced about a body. When three of the arms are in contact with a horizontal surface, the fourth arm is vertically oriented.
U.S. Pat. No. 2,912,229 to Persgard is titled Vehicle Impeding Device. This patent illustrates the use of spikes that are releasably received within a base, and as such, can be picked up by a tire.
U.S. Pat. No. 5,328,292 to Williams is titled Traffic Barrier Chain. This patent shows a barrier chain having splines, wherein ½ of the splines face the direction of the traffic flow at an angle of 45 degrees. The splines, however, do not appear to be removable from the chain. Also, any deviation from having the chain deployed perpendicular to the flow of traffic will result in deviation from the illustrated puncture angle.
U.S. Pat. No. 5,921,703 to Becker et al. is titled Caltrop. This patent illustrates a rigid caltrop structure that is formed from two metallic members which abut each other and are welded together. Pairs of adjacent corners of sides of triangular portions create penetration points. When three of the penetration points rest on a horizontal surface, the fourth penetration point projects upwards. The angle of penetration point projection is dependent upon the rotational angle of the caltrop relative the road surface.
U.S. Pat. No. 6,312,189 to Marphetia is titled Vehicle Tire Puncturing and Deflating Spike and Assembly Therefor. This patent shows a configuration of a metal spike.
U.S. Pat. No. 7,210,875 to Christle et al. is titled Entrapment Snare for the Termination of Vehicle Pursuits. This patent illustrates the use of two small but heavy weights connected by a flexible cable covered with spikes. FIG. 12 of this patent illustrates a spike design wherein all of the spikes are within a singular plane. Also, the spikes do not appear to be removable from the chain.
None of the existing products, including those illustrated in the above-mentioned patents teach, show or suggest spike assembly containing multiple spikes that can be removably attached to a deployment string.
Further, it is the industry standard to use metal spikes. This is because plastic is regarded as either too brittle (subject to shatter) or too flexible (incapable of puncture) to be used as road spikes. Yet metal spikes can be expensive, heavy and may require corrosion prevention protection. Hence, an engineered solution using plastics is desirable, both as replacement spikes in existing systems and as integrated devices.
Still further, none of the existing products, including those illustrated in the above-mentioned patents teach, show or suggest a configuration aligns at least one spike angled vertically divergent towards oncoming traffic regardless of device rotational orientation.
Related, none of the existing products, including those illustrated in the above-mentioned patents teach, show or suggest a six point configuration wherein the device is automatically self-leveling and self-centering on three spikes and having three remaining spikes project upwards with at least one spike being angled vertically divergent towards oncoming traffic regardless of the device rotational orientation.
Thus, there exists a need for road spikes with improved characteristics that solves these and other problems.
SUMMARY OF THE INVENTION
The present invention relates to road spikes with improved characteristics and methods of deployment, and in particular to road spikes made of long fiber reinforced thermoplastics that, when deployed, are geometrically positioned to puncture or disable a tire. The spikes can be formed of a long fiber reinforced thermoplastic containing 10-70% long fibers by weight. Spikes of this material can be made as direct and/or alternative replacements for existing metal spikes or as unique integrated devices. One integrated component is a device having several piercing elements that are deployed in a vertically divergent manner spaced about a vertical axis wherein at least one piercing element is directed towards the direction of the oncoming vehicle. The device can be configured to deploy from a carrier strip or a flexible string. In one embodiment deployable from a string, this is accomplished through the use of spikes with six piercing elements that are self-leveling and self-centering.
According to one advantage of the present invention, spikes made of long fiber reinforced thermoplastic can be provided. Advantageously, the spike can be comprised of approximately 10-70% long fiber by weight, wherein the fibers can be chopped to discontinuous lengths of fiber. The long fiber reinforced thermoplastic is strong and stiff to ensure piercing, and tough to prevent shattering. Further, long fiber reinforced thermoplastic is light weight, cost-effective, recyclable, reusable and does not require corrosion prevention measures. Spikes of this material can be made specifically as replacement spikes in existing systems, or can be incorporated into novel integrated configurations.
According to another advantage of the present invention, a device can be provided wherein at least one spike is angled vertically divergent towards oncoming traffic regardless of device rotational orientation. This can be accomplished in one embodiment wherein three or more piercing elements are oriented in vertically divergent positions and spaced about a vertical axis, and a base is removable held in a carrier strip. This is accomplished in another embodiment with a six point configuration wherein the device is automatically self-centering and self-leveling on three spikes and has the three remaining spikes project upwards with at least one spike being angled vertically divergent towards oncoming traffic regardless of the device rotational orientation.
According to a further advantage of one embodiment of the present invention, the device can be designed to break free from a chain upon impaling of a tire.
According to a still further advantage yet of the present invention, the device can be an integrated device.
According to a still further advantage of the present invention, a string with multiple devices is both easily storable in a compact manner and easy deployable across a relatively wide section of road. Related, successful deployment can be accomplished from a moving vehicle without the need for precision, due to the self-centering and self-leveling configuration and the ability to be properly angularly aligned relative the target vehicle regardless of angular orientation.
Other advantages, benefits, and features of the present invention will become apparent to those skilled in the art upon reading the detailed description of the invention and studying the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a top view of one preferred embodiment of the present invention.
FIG. 2 is a side view of the preferred embodiment of the present invention illustrated in FIG. 1 .
FIG. 3 is a perspective view of the preferred embodiment of the present invention illustrated in FIG. 1 .
FIG. 4 is a perspective view showing several devices attached to a deployment string in a deployed position.
FIG. 5 is a close-up view of a portion of FIG. 4 as noted by circle- 5 .
FIG. 6 is a perspective view showing many devices attached to a deployment string in a storage position.
FIG. 7 is a perspective view showing a preferred embodiment of a spike.
FIG. 8 is a cross-sectional view taken along line 8 - 8 in FIG. 7
FIG. 9 is a perspective view of an alternative preferred embodiment of the present invention.
FIG. 10 is a side view of the alternative preferred embodiment of the present invention shown in FIG. 9 .
FIG. 11 is a top view of the alternative preferred embodiment of the present invention shown in FIG. 9 .
FIG. 12 is a cross-sectional view taken along line 12 - 12 in FIG. 11 .
FIG. 13 is a top view of one embodiment of a carrier strip.
FIG. 14 is a side view showing several devices attached to the carrier strip illustrated in FIG. 13 .
FIG. 15 is a top view of FIG. 14 .
FIG. 16 is a cross-sectional view taken along line 16 - 16 in FIG. 15 .
FIG. 17 is a perspective view of an alternative preferred embodiment of the present invention.
FIG. 18 is a bottom view of the alternative preferred embodiment shown in FIG. 17 .
FIG. 19 is a top view of the alternative preferred embodiment shown in FIG. 17 .
FIG. 20 is a side view of the alternative preferred embodiment shown in FIG. 17 .
FIG. 21 is a perspective view of an alternative embodiment shown in a folded position.
FIG. 22 is a perspective view of the alternative embodiment shown in FIG. 21 , but in a storage container.
FIG. 23 is a perspective view of the alternative embodiment shown in FIG. 21 shown in a straight deployed orientation.
FIG. 24 is a close up perspective view of a preferred cluster.
FIG. 25 is a perspective view of an alternative embodiment showing a trigger assembly connected to a rail.
FIG. 26 is a perspective view of the alternative embodiment shown in FIG. 25 in a storage position.
FIG. 27 is a close up perspective exploded view showing an end to end relationship of several rails.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
While the invention will be described in connection with several preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.
Starting with FIGS. 7 and 8 , it is seen that a spike 180 having a tip 181 , a base 182 with an inside 183 and an outside 184 , and having flutes 185 is provided. The base can fit over a male connector on an existing track, or alternatively act as a male connector that fits within a cup or hole in the track.
The spike 180 is fully interchangeable with existing metal spikes. However, it is appreciated that spike 180 is preferably made of long fiber reinforced thermoplastic. In the preferred embodiment, the long fiber content by weight is approximately 10-70%. It is even more preferred that the long fiber content by weight be approximately 30-50%. However, it is understood that relative amounts outside of the preferred range may be used without departing from the broad aspects of the present invention. One preferred fiber is E-glass fibers. Another is carbon fiber. It is also understood that other fibers, such as natural fibers derived from plants and wood including lignin and cellulose, or other synthesized organic fibers such as polyester, non-organic such as synthetic carbon fiber or metallic such as stainless steel may be used without departing from the broad aspects of the present invention. It is preferred that the average fiber length is approximately 2-4 millimeters with a 25-30% Gaussian distribution around the average. Yet, it is understood that it may be possible to use fiber lengths that are shorter or longer without departing from the broad aspects of the present invention. Spikes formed with this reinforcement are strong enough to puncture or pierce tires, yet tough enough to resist shattering under the large amounts of force imparted upon the spike by an automobile tire.
Formation of the spikes 180 can be accomplished with any suitable process including injection, compression or injection-compression molding, or any other plastic-forming/shaping process. Raw materials can be provided as a prefabricated pellet of fiber embedded in resin, or alternatively can be provided separately for in-line mixing of resin and fiber.
Turning now to FIGS. 1-3 , it is seen that a preferred embodiment of a device 10 is illustrated. The device 10 , when deployed on a surface 5 , has a vertical axis 15 . The device has a central hub 20 . A plurality of piercing elements (described below) extends approximately 1.5 inches from the center of the hub 20 . The device 10 is preferably made of long fiber reinforced thermoplastic. However, other materials can be used without departing from the broad aspects of the present invention.
Piercing element 30 has a point 31 , a base 32 connected to the hub 20 side flutes 33 . Piercing element 40 has a point 41 , a base 42 connected to the hub 20 side flutes 43 . Piercing element 50 has a point 51 , a base 52 connected to the hub 20 side flutes 53 . Piercing element 60 has a point 61 , a base 62 connected to the hub 20 side flutes 63 . Piercing element 70 has a point 71 , a base 72 connected to the hub 20 side flutes 73 . Piercing element 80 has a point 81 , a base 82 connected to the hub 20 side flutes 83 .
Each piercing element is preferably cone-shaped, and all of the piercing elements are preferably equally space about the hub 20 . In this regard, with six piercing elements, each piercing element is spaced approximately 90 degrees from the four adjacent piercing elements, and is preferably collinear with the one opposite piercing element.
Four retainers 90 , 100 , 110 and 120 are further provided. Retainer 90 has a slot 91 and a neck 92 . Retainer 100 has a slot 101 and a neck 102 . Retainer 110 has a slot 111 and a neck 112 . Retainer 120 has a slot 121 and a neck 122 . The slots are preferably round in perimeter and are designed to receive a deployment string 130 (described below). The necks are preferably smaller than their respective slots, wherein a predetermined amount of force is necessary to force the string through the neck to remove the device from the string. Retainer 90 preferably spans between piercing elements 30 and 40 . Retainer 100 preferably spans between piercing elements 40 and 50 .
Retainer 110 preferably spans between piercing elements 50 and 60 . Retainer 120 preferably spans between piercing elements 60 and 30 . It is illustrated that all of the retainers lie in a single plane. However, it is understood that other retainer locations, configurations and/or numbers of retainers could be utilized without departing from the broad aspects of the present invention.
Device 10 is designed for use on a deployment string and alternatively as a stand-alone tool. FIGS. 4-6 illustrate engagement of multiple devices 10 , 10 A and 10 B on a deployment string. In particular, FIG. 4 illustrates several devices in the deployed position, and FIG. 6 illustrates the devices and deployment string in a storage position.
When deployed, three of the piercing elements contact a surface, roadway or ground. It is appreciated that any three adjacent elements can simultaneously contact the surface and in this regard the device is self-centering, self-balancing and self-leveling. The remaining three piercing elements supported in an upwardly projected orientation. It is preferred that the piercing elements project in a vertically divergent manner. It is also preferred that the three projecting elements are equidistant from each other about the vertical axis 15 . In this regard, at least one piercing element will be angled generally towards the tire of an oncoming vehicle regardless of the rotational orientation of the device 10 about the vertical axis relative. It is understood that the devices 10 can be deployed from a moving vehicle, due to the self centering aspects of the present invention.
In the preferred embodiment, the device 10 detaches from the deployment string upon being impaled by the tire. However, the device could alternatively be designed such that the remainder of the string winds around the vehicle axis when one device impales the tire without departing from the broad aspects of the present invention.
Turning now to FIGS. 9-12 , it is seen that an additional preferred embodiment of a device 210 is illustrated. The device 210 , when deployed on a carrier strip 280 , has a vertical axis 215 . A base 220 is provided, as is a plurality of piercing elements 230 , 240 , 250 , 260 and 270 . The device 210 is preferably made of long fiber reinforced thermoplastic. However, other materials can be used without departing from the broad aspects of the present invention.
Base 220 has a cylindrical outside 221 and an interior shaft 222 . A fastener 225 , such as a pop rivet, can be used to secure the device 210 to a hole 283 between the ends 281 and 282 of a carrier strip 280 . The cylindrical outside can alternative friction fit within a carrier strip hole without a separate fastener without departing from the broad aspects of the present invention.
Piercing element 230 has a point 231 , a base 232 connected to the base 220 side flutes 233 . Piercing element 240 has a point 241 , a base 242 connected to the base 220 side flutes 243 . Piercing element 250 has a point 251 , a base 252 connected to the base 220 side flutes 253 . Piercing element 260 has a point 261 , a base 262 connected to the base 220 side flutes 263 .
Piercing elements 230 , 240 , 250 and 260 are preferably vertically divergent from each other. Each element is preferably equidistantly spaced about the vertical axis 215 and is preferably oriented approximately 60 degrees from vertical. Yet, it is understood that other angles of vertical divergence, other numbers of piercing elements and/or variably spaced piercing elements may be utilized without departing from the broad aspects of the present invention.
Piercing element 270 has a point 271 , a base 272 connected to the base 220 side flutes 273 . Piercing element 270 is preferably vertically oriented on the device 210 and is connected to the base 220 .
Each of the piercing elements preferably generally has a conical shape. However, other shapes could be used without departing from the broad aspects of the present invention.
A preferred embodiment of the carrier strip 280 is illustrated in FIGS. 13-16 . The strip 280 is shown to have a generally rectangular perimeter, and is shown to be straight. However, other perimeter shapes and other orientations are within the scope of the present invention. The strip can be made of rigid or flexible materials, such as metal, leather, wood or any other suitable material. It is further appreciated that other types of carrier strips, such as accordion-style or other strips, may be utilized without departing from the broad aspects of the present invention.
Turning now to FIGS. 17-20 , it is seen that another preferred embodiment is illustrated. In this embodiment, a device cluster 310 is provided. The cluster 310 has a hub 320 , and a frame 330 comprising cross piece 331 and end pieces 332 and 333 , respectively. The hub 320 is preferably centrally located within the frame 330 .
A spike 340 having a vertically oriented piercing element 341 and a plurality of vertically divergent piercing elements 342 is provided. In this illustrated embodiment, four vertically divergent piercing elements are provided.
A spike 350 having a vertically oriented piercing element 351 and a plurality of vertically divergent piercing elements 352 is provided. In this illustrated embodiment, four vertically divergent piercing elements are provided.
A spike 360 having a vertically oriented piercing element 361 and a plurality of vertically divergent piercing elements 362 is provided. In this illustrated embodiment, four vertically divergent piercing elements are provided.
A spike 370 having a vertically oriented piercing element 371 and a plurality of vertically divergent piercing elements 372 is provided. In this illustrated embodiment, four vertically divergent piercing elements are provided.
Spikes 340 , 350 , 360 and 370 are preferably integrally connected to frame 330 . This can be accomplished by forming the device cluster 310 in a multiple-cavity mold. The hub 320 can attach to a base in an existing carrier strip or device.
Turning now to FIGS. 21-24 , it is seen that a further preferred embodiment of the device 410 is illustrated. Device 410 can be selectably folded for storage in a container 420 , and straightened for deployment on a road or other surface.
In one embodiment, a gas canister 430 is provided for selectably inflating tube 440 . One preferred gas is air. However, it is understood that many gasses could be used without departing from the broad aspects of the present invention. Tube 440 has ends 441 and 442 . A plurality of folds 443 separate segments that are generally straight. The segments are generally parallel when the tube is in a deflated storage position. However, the inflation of the tube 440 causes the folds 443 to release and the tube 440 to straighten. The straightened length of the device is several times the length of the stored device.
A plurality of clusters 450 are preferably removably connected to tube 440 . In the preferred embodiment, one cluster 450 is connected to the tube 440 in each segment. Clusters each have a central hub 455 . A frame 456 , preferably one that is rigid, extends away from the hub 455 in a plane 458 that lies generally perpendicular to a vertical axis 457 of the cluster.
The frame 456 supports preferably four upwardly oriented piercing elements 460 , and also four downwardly oriented piercing elements 470 . All the piercing elements preferably have a central axis that is parallel with the vertical axis 457 of the cluster 450 . It is appreciated that more or fewer piercing elements 460 and 470 may be used without departing from the broad aspect of the present invention.
The clusters 450 are self centering. In this regard, there are always upwardly and downwardly oriented piercing elements regardless of whether the cluster is flipped or tipped on the deployment surface.
Turning now to FIGS. 25-27 , it is seen that a still further alternative embodiment of the present invention is illustrated. The device 510 is mountable on a rail 520 . The rail 520 has ends 522 and 523 . The first end of one rail is mountable with the second end of the adjacent rail. Two adjacent rails can be secured in an end-to-end (via quick connect pieces) arrangement with a segment of extendable chord. Each rail 520 has many holes or notches 524 formed through the rail along its longitudinal axis.
Trigger assemblies 530 are secured along the rail 520 , having protrusions that extend through selected notches. Spacing of the trigger assemblies can vary widely. Each trigger assembly received a piercing element. Three configurations are shown in FIG. 25 (insertion, set, and removal).
Trigger assembly 530 has a vertical axis extending through the base 540 . A support arm 541 and a latch 542 operate to secure the piercing element 550 within a hole 544 in the base. The support arm 541 engages a flute of the piercing element in order to secure the piercing element in place. A second support arm 543 is also provided for engaging the piercing element.
Insertion of piercing element 550 B into trigger assembly hole 544 B of base 540 B of trigger assembly 530 B is also shown in FIG. 25 . The latch 542 B and support arm 541 B are shown ready to lock the piercing element 550 B in place.
Piercing element 550 A is locked in place within trigger assembly 530 A. Support arm 541 A and latch 542 B are positioned so as to orient the end of support arm 541 A in engagement with a fluted side of the piercing element. Arm 543 A is also seen to be engaging piercing element 550 A. It is seen that the vertical axis of the piercing element is preferably vertically divergent from the vertical axis 531 A of the trigger assembly 530 A when the piercing element is inserted into the trigger assembly.
Piercing element 550 is shown being released from the trigger assembly 530 . This occurs when or after the piercing element 550 is impaled by a tire or the like.
Thus it is apparent that there has been provided, in accordance with the invention, road spikes with improved characteristics and methods of deployment that fully satisfies the objects, aims and advantages as set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims.
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The present invention relates to road spikes that can made of long fiber reinforced thermoplastics that, when deployed, are geometrically positioned to puncture or disable a tire. The spikes can be formed of a long fiber reinforced thermoplastic containing 10-70% long fibers by weight. Spikes of this material can be made as direct and/or alternative replacements for existing metal spikes or as unique integrated devices. One integrated component is a device having several piercing elements that are deployed in a vertically divergent manner spaced about a vertical axis wherein at least one piercing element is directed towards the direction of the oncoming vehicle. In one embodiment deployable from a string, this is accomplished through the use of spikes with six piercing elements that are self-leveling and self-centering. In another embodiment, several clusters can be fixed to a tube that is foldable and extendable.
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This application claims priority under 35 U.S.C. §§ 119 and/or 365 to Appln. No. 2001 1010/01 filed in Switzerland on Jun. 1, 2001; the entire content of which is hereby incorporated by reference.
FIELD OF THE INVENTION
The present invention relates to a burner for a gas turbine or hot-gas generation for the combustion of liquid or gaseous fuel and to a method for operating it.
BACKGROUND OF THE INVENTION
A principal problem which has to be solved within the framework of the development of industrial premixing burners for use in gas turbines or for hot-gas generation is the stabilization of the flame primarily in the part-load operating mode. Most industrial burners of this type utilize a swirl flow for generating a backflow zone on the burner axis. In these burners, flame stabilization takes place aerodynamically, that is to say without special flame holders. In this case, the backflow zones, which occur during the breakdown of the vortex, or the outer recirculation zones are utilized. Hot exhaust gases from these zones in this case ignite the fresh fuel/air mixture.
A burner according to the prior art, in which, for example, a backflow zone of this type is formed on the axis of the burner, is described in EP 0 210 462 A1. In the dual burner, specified there, for a gas turbine, the swirl body is formed from at least two double-curved metal plates acted upon by tangential air inflow, the plates being folded so as to be widened outward in the outflow direction. During outflow into the combustion chamber, a backflow zone at the downstream end of the inner cone is formed on the axis of the burner as a result of the increasing swirl coefficient in the flow direction. The geometry of the burner is in this case selected such that the vortex flow at the center has low swirl and axial velocity excess. The increase in the swirl coefficient in the axial direction then leads to the vortex backflow zone remaining in a stable position.
Further examples of what are known as double-cone burners are found in the prior art in EP 0 321 809 B1 and in EP 0 433 790 B1. In these burners with a conical shape opening in the flow direction, in which there are two part-cone bodies which are positioned one on the other and the center axes of which run, offset to one another, in the longitudinal direction, combustion air flows through the tangential inflow slots formed as a result of the offset into the interior of the burner. Simultaneously, during inflow through these slots, fuel is admixed with the combustion air, with the result that a conical fuel/combustion-air cone is formed and, again, a backflow zone in a stable position is formed in the region of the burner mouth.
In burners of this type, a power output reduction is achieved principally by a reduction in the fuel mass flow, with the air mass flow remaining approximately constant. That is to say, in other words, that, with a decreasing power output, the fuel/air mixture becomes increasingly leaner. However, since modern premixing burners are already operated near the lean extinguishing limit for the purpose of NOx minimization, other combustion concepts have to be developed for the part-load operating mode, in order to prevent extinguishing or an unstable behavior in the case of an increasingly leaner fuel/air mixture.
The prior art discloses, as combustion concepts for the part-load operating mode, for example, what is known as burner staging, in which individual burners are switched off in a specific manner, so that the remaining burners can be operated under full load. Particularly in the case of annular combustion chambers with a plurality of mutually offset burner rings having a different radius, this concept can be employed with a certain amount of success.
On the other hand, the transition from premixing combustion to diffusion-flame-like combustion is proposed, which, as is known, has a lower extinguishing limit in relation to the temperature. Consequently, a double operation of individual burners, which is employed according to the load, to be precise a premix-like and a diffusion-like operation, is proposed, in order to prevent extinguishing in the part-load mode. The problem with this, however, is that, on the one hand, it is complicated to design a burner for two different operating modes and, on the other hand, diffusion-like combustion usually cannot be carried out optimally in terms of emissions.
EP 0 866 267 A1 discloses the mixing of fresh air with recirculated smoke gas in the mirror-symmetrically tangentially arranged feed ducts of a double-cone burner in the case of atmospheric combustion. The combustion air enriched with the recirculated exhaust gas gives rise, for example, to better evaporation of the liquid fuel fed, via a central fuel nozzle, within the premixing zone induced by the length of the premixing burner. Although a lowering of pollutant emissions can consequently advantageously be achieved, nevertheless one disadvantage in a stabilization of the burner during the starting phase is that it is necessary to have a blow-off device which is connected operatively to the air plenum and by the use of which the admission pressure in the plenum is lowered, the air mass flow through the burner is reduced and consequently the air ratio is decreased.
SUMMARY OF THE INVENTION
The object of the invention is, therefore, to make available a burner for a gas turbine or hot-gas generation for the combustion of liquid or gaseous fuel, in which burner fuel is mixed with combustion air in a burner interior, is fed to a combustion chamber and is burnt in this combustion chamber, and a method for operating a burner of this type, which makes it possible to have a stable part-load operating mode.
As already mentioned above, double-cone burners from the prior art cannot achieve the abovementioned object, since, because operation is already lean in the full-load mode, in the part-load mode the flame becomes unstable or is even extinguished.
The present invention achieves the object by the provision of means which can stabilize the flame in the part-load mode.
The subject of the invention is consequently a burner of the abovementioned type, in which means are provided which make it possible to recirculate hot exhaust gas out of the combustion chamber into the burner interior for stabilization in the part-load mode.
The essence of the invention is, therefore, that the hot exhaust gases from the combustion chamber are used to stabilize the flow behavior in the burner interior and near the burner mouth, particularly in the part-load mode, that is to say during lean operation with reduced power output. Such recirculation of exhaust gases makes it possible to use burners of this type in machines (in particular, machines with variable inlet guide vane assemblies, VIGV) in a load range 30-100%.
According to a first preferred embodiment of the invention, the means are a recirculation line which, furthermore, picks up preferably hot exhaust gas on an axial combustion chamber wall near outer backflow zones present next to the burner mouth issuing into the combustion chamber and which feeds it to the burner interior in the region of a burner tip facing away from the combustion chamber. In such recirculation of the hot exhaust gases from a backflow zone, this recirculation takes place usually passively, that is to say the flow of hot exhaust gas into the burner interior does not have to be driven.
Another embodiment of the invention is distinguished in that the burner has at least one inner backflow zone. In a burner of this type, the result of the recirculation of the hot exhaust gases is that precisely this inner central backflow zone is stabilized on the axis of the burner by these hot exhaust gases.
In a further embodiment of the invention, the burner is a double-cone burner with at least two part-cone bodies positioned one on the other and having a conical shape opening toward the combustion chamber in the flow direction, the center axes of these part-cone bodies running, offset to one another in the longitudinal direction, in such a way that tangential inflow slots into the burner interior are formed over the length of the burner, through which inflow slots combustion air flows in, fuel being injected at the same time into the burner interior, so as to form a conical swirling fuel column and, subsequently, the mixture flows out, so as to form an inner backflow zone, into the combustion chamber and is burnt there. Particularly in the case of a double-cone burner of this type, the stabilization of the backflow zone on the burner axis can commence efficiently. In this case, the inner central backflow zone is stabilized particularly effectively when the hot exhaust gas is fed to the burner interior centrally in the vortex core, that is to say essentially on the burner axis, and, moreover, preferably as near as possible to the burner tip, that is to say at the point of the double-cone burner with the smallest diameter. The recirculation of the hot exhaust gases may in this case even take place actively in such a way that, in particular in the part-load mode, an inner backflow zone is completely or partially prevented.
According to a further embodiment of the invention, moreover, means are provided which make it possible to admix fuel with the hot recirculated exhaust gas. In combination with the increased temperature of the hot exhaust gases, this admixing of fuel leads to a selfigniting mixture being fed to the burner interior. Preferably, furthermore, fuel injection, exhaust-gas temperature and flow velocity are coordinated with one another in such a way that selfignition of the fuel takes place in the combustion chamber.
According to another preferred embodiment of the invention, not only fuel, but additionally also pilot air, is admixed with the recirculated hot exhaust-gas air. The admixing of the pilot air may in this case take place on the injection principle, that is to say in a way which drives the exhaust-gas air stream. By the additional introduction of pilot air into the exhaust-gas air duct, the burner can be actively regulated optimally in the part-load mode, using only a little additional air. To be precise, the usually cold pilot air may, on the one hand, be used for setting the temperature of the recirculated exhaust-gas air, but, on the other hand, the pilot air may also be utilized for increasing or lowering the exhaust-gas air stream, that is to say the flow velocity. Consequently, with the aid of the pilot air, selfignition, that is to say, in particular, the selfignition location of the mixture of hot exhaust gas and the fuel in or upstream of the burner interior in the combustion chamber, can be set exactly, that is to say optimized in terms of the influence exerted on the backflow zones.
The present invention relates, furthermore, to a method for operating a burner, such as is described above. Thus, in particular, exhaust gas recirculation is cut in and cut out as a function of the instantaneous power output stage of the burner, and, in particular, preferably the recirculation of hot exhaust gas is employed in the part-load mode. According to a preferred embodiment of the method mentioned, in this case the pilot-air stream is used for controlling the formation of the inner backflow zone or else also in order to block the recirculation of the exhaust-gas air, so that the swirl of the main airflow is sufficient to cause a breakdown of the vortex.
Further preferred embodiments of the burner and of the method are described in the dependent patent claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be explained in more detail below with reference to exemplary embodiments, in conjunction with the drawings, in which:
FIG. 1 shows a double-cone burner in axial section and the backflow zones occurring during operation;
FIG. 2 shows a double-cone burner according to FIG. 1 with exhaust gas recirculation;
FIG. 3 shows the selfignition time of a fuel/air mixture as a function of the temperature;
FIG. 4 shows a double-cone burner according to FIG. 2, in which the central backflow zone is prevented; and
FIG. 5 shows a double-cone burner according to FIG. 4, in which pilot air can be supplied in addition to the hot recirculated exhaust-gas air.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a double-cone burner 1 , formed from two part-cone bodies 6 , the axes of which are offset relative to one another in such a way that a slot 7 is formed between the part-cone bodies 6 . Combustion air 9 b flows tangentially through this slot 7 into the burner interior 14 . Moreover, axial combustion air 9 a is supplied to the burner interior 14 from the side of the burner tip 2 where the diameter of the burner is at a minimum. Fuel 8 is admixed with the tangential combustion air 9 b , so that a conical swirling cone consisting of a fuel/air mixture is formed in the burner interior 14 . In addition to the admixing of fuel near the slot 7 between the part-cone bodies 6 , in particular, liquid fuel can also be supplied to the burner interior 14 axially, that is to say near the burner tip 2 , via a central nozzle.
During the outflow of this cone into the combustion chamber 3 , various backflow zones are formed at the same time. On one side, what are known as outer backflow zones 10 are formed laterally next to the burner mouth, these backflow zones being delimited, on the one hand, by the axial combustion chamber wall 5 , and, on the other hand, by the radial combustion chamber wall 4 . The radial combustion chamber wall 4 does not in this case necessarily have to be present, however, since a plurality of burners 1 may also be arranged next to one another. Moreover, an inner backflow zone 11 , which occurs during the breakdown of the vortex, is formed on the burner axis 12 as a result of the swirl coefficient which increases in the direction of the combustion chamber.
FIG. 1 also illustrates a graph which represents the axial velocity distribution 13 as a function of the x-coordinate along the burner axis 12 in the region of the inner backflow zone 11 . It can be seen from this that, at a specific point upstream of the burner mouth, the axial velocity of the gas passes through the zero point and becomes negative, that is to say exactly the backflow zone 11 occurs. The burner according to FIG. 1 is a burner such as is described, for example, in European patent applications EP 0 321 809 B1 and EP 0 433 790 B1.
FIG. 2, then, shows how, according to the invention, hot exhaust gas 17 is fed out of the combustion chamber 3 , particularly preferably out of the outer backflow zones 10 , along the axial combustion chamber wall 5 , via a recirculation line 15 , to the burner interior 14 . The central injection portion 16 of the recirculation line 15 is in this case advantageously arranged on the burner axis 12 , so that the hot exhaust gas 17 is injected in the vortex core of the conical fuel/combustion-air cone formed in the burner interior 14 . Optimum stabilization of the inner recirculation zone 11 is thereby brought about. The flow of recirculated exhaust gas in this case moves typically within the range of 2-10%.
If the recirculated exhaust gas 17 is additionally mixed with fuel (pilot fuel 21 ), a selfigniting mixture can be formed, depending on the exhaust-gas temperature T, the fuel concentration and the dwell time. FIG. 3, in this respect, shows the selfignition time in ms of a fuel/air mixture at a pressure of 15 bar, in the case of 1=2.7, and with an oxygen content of 15 percent, as a function of the temperature in degrees Celsius.
In a double-cone burner 1 as described above (for example, a burner of the type EV 17 of the applicant), nominal velocities of 30 m/s typically occur, dwell times of 2 to 7 ms being obtained. In other words, at the typical temperatures of the recirculated hot exhaust gases 17 of 700 to 800 degrees Celsius, such short selfignition times are obtained that selfignition occurs before the mixture leaves the burner.
FIG. 4, then, shows a section through a double-cone burner, in which the recirculated hot exhaust gas 17 influences the vortex core to such an extent that an inner backflow zone 11 can no longer be formed. This pronounced exertion of influence may take place in that either a large flow of hot exhaust gas 17 is injected into the vortex core or, in particular, in that additional fuel 21 is admixed with the hot exhaust gas 17 . This is, as it were, a burner with active exhaust gas recirculation. Again, approximately 2-10% of the exhaust gas is recirculated. In order to position the selfignition location of the mixture of hot exhaust gas 17 and fuel in the right place in the vortex core, that is to say in order to prevent a backflow zone, in particular for the part-load mode, the flow velocity and the exhaust-gas temperature must be coordinated exactly with one another. If the backflow zone is prevented in the region of the zone 18 , an axial velocity distribution 19 , such as is illustrated in the lower part of FIG. 4, is established. The velocity of the air stream flowing on the burner axis 12 still experiences a reduction in velocity v in the zone 18 , but there is no longer any zero passage, and no negative velocities occur, that is to say a backflow zone is absent.
FIG. 5 illustrates a further exemplary embodiment, in which not only is additional fuel 21 admixed with the hot exhaust gases 17 , but, in addition, pilot air 20 is used for controlling the hot exhaust-gas stream 17 . The pilot air 20 may, in principle, be admixed with the hot exhaust gas 17 at any desired point in the recirculation line 15 . Preferably, however, for the sufficient mixing of pilot air and exhaust-gas air, injection takes place at least 10 pipe diameters upstream of the injection point. The routing of the pilot air 20 may in this case advantageously be organized on the injector principle, that is to say in such a way that the flow velocity of the hot exhaust gases 17 can be driven by the pilot air 20 . Alternatively, the routing of the pilot air 20 may be designed in such a way that the recirculated exhaust-gas stream 17 can be blocked, and the swirl of the main airflow is sufficient to cause a breakdown of the vortex. If, in this arrangement, the pilot air 20 is cut off, stabilization takes place again via the selfignition process.
The pilot-air stream 20 makes it possible, using comparatively little additional air, on the one hand, to set the temperature of the recirculated exhaust gas 17 and consequently the selfignition time and also to control the formation of the inner recirculation zone. Typically, less than 10% of the total burner air is supplied via recirculation (pilot air and exhaust-gas air).
The recirculation of hot exhaust gas into the burner interior for stabilization in the part-load mode may also be employed in other burners, for example in burners of the type AEV of the applicant, in which a mixing zone in the form of a pipe is arranged downstream of the swirl generator in the form of the double cone (cf., for example, EP 0 780 629 A2). These burners consist, in general terms, of a swirl generator for a combustion-air stream, which swirl generator may take the form of a double cone or else the form of an axial or radial swirl generator, and of means for injecting a fuel into the combustion-air stream. Moreover, they are characterized in that, downstream of the swirl generator, a mixing zone is arranged, which has, within a first zone part, transitional ducts, running in the flow direction, for transferring a flow formed in the swirl generator into a pipe located downstream of the transitional ducts, the outflow plane of this pipe into the combustion chamber being designed with a breakaway edge for stabilizing and enlarging a backflow zone which is formed downstream. In these burners, too, a stable inner and outer backflow zone is formed downstream of the breakaway edge in the combustion chamber.
The recirculation of the hot exhaust gases for stabilization in the part-load mode takes place, here too, out of the combustion chamber, in particular preferably so as to be picked up next to the burner mouth, via a recirculation line which injects the hot exhaust gases, if appropriate with the admixing of pilot air and/or fuel, preferably axially centrally into the burner tip, that is to say, in this case, into the center of that end of the swirl generator which faces away from the combustion chamber.
The novel method for exhaust gas recirculation may also be employed in a burner such as is described, for example, in DE 19640198 A1. In a burner of this type, the swirl generator arranged upstream of the mixing pipes configured cylindrically, but, in its interior, has a conical inner body running in the flow direction. The outer casing of the interior is pierced by tangentially arranged air inflow ducts, through which a combustion-air stream flows into the interior. The fuel is in this case injected via a central fuel nozzle arranged at the tip of the inner body. In a burner of this type, too, a stable inner and outer backflow zone are formed downstream of the breakaway edge in the combustion chamber.
Here, too, for stabilization in the part-load mode, the recirculation of the hot exhaust gases takes place out of the combustion chamber, again preferably so as to be picked up next to the burner mouth, via a recirculation line which injects the hot exhaust gases, if appropriate with the admixing of pilot air and/or fuel, preferably axially centrally. Axially centrally means, in this case, that injection preferably takes place near the tip of the inner body tapering in the flow direction, into the swirl center, that is to say in the region of fuel injection.
LIST OF DESIGNATIONS
1 double-cone burner
2 burner tip
3 combustion chamber
4 combustion chamber wall (radial)
5 combustion chamber wall (axial)
6 part-cone body
7 inflow slot between part-cone bodies
8 fuel injected at the gap
9 a axially inflowing combustion-air stream
9 b tangentially inflowing combustion-air stream
10 outer recirculation zone
11 Iinner recirculation zone
12 burner axis
13 velocity distribution in the axial direction
14 burner interior
15 recirculation line
16 central injection portion
17 recirculated hot exhaust gas
18 zone with exhaust gas recirculation and selfignition
19 axial velocity distribution
20 pilot air
21 additional fuel (pilot fuel)
v axial velocity
x axial direction
t selfignition time
T gas temperature
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In a premixing burner ( 1 ) for a gas turbine or hot-gas generation for the combustion of liquid or gaseous fuel, in which fuel is mixed with combustion air ( 9 a , 9 b ) in a burner interior ( 14 ), is fed to a combustion chamber ( 3 ) and is burnt in this combustion chamber ( 3 ), stabilization in the part-load model is achieved in a simple and efficient way in that means ( 15 ) are provided which make it possible to recirculate hot exhaust gas ( 17 ) out of the combustion chamber ( 3 ) into the burner interior ( 14 ) and to stabilize the flame by means of selfignition processes. The means ( 15 ) are preferably a recirculation line which picks up hot exhaust gas ( 17 ) from the outer backflow zone ( 10 ) and feeds it to the burner interior ( 14 ) in the region of a burner tip ( 2 ) facing away from the combustion chamber ( 3 ), additional fuel (pilot fuel 21 ) being admixed with the exhaust gas ( 17 ) in the recirculation line upstream of the feed to the burner interior ( 14 ).
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[0001] This Application claims the benefit of U.S. Provisional Application No. 62/073,389 filed Oct. 31, 2014.
FIELD OF THE INVENTION
[0002] The present invention relates generally to plumbing fixtures and to the component parts that are used in them. More particularly, it relates to a flush lever of the type that is used in gravity flush toilets. It also relates to such a flush lever that is able to be mounted in a variety of positions relative to the tank of the flush toilet.
BACKGROUND OF THE INVENTION
[0003] Conventional toilets typically employ a number of essential components. First, a porcelain water tank is mounted immediately above a porcelain bowl from which a quantity of water is rapidly drained in order to flush waste from the bowl into a sewer system. One very common design uses a flapper valve made of an elastomeric material that covers the drain outlet of the tank. When the flush handle on the outside of the tank is manually actuated, typically by pushing the handle downwardly, the flapper valve is lifted by means of a flush lever via a chain or other connecting means. This allows the head of water in the tank to drain through the flush valve and the drain outlet. The flapper valve is typically designed with an inverted air chamber so that it initially floats as it is lifted away from the drain outlet in the bottom of the tank. This allows sufficient flushing water to flow into the bowl even if the user immediately releases the flush handle. When the water level in the tank drops, the tank is automatically refilled through a fill valve connected to a water supply line.
[0004] Current flush levers used with toilet tanks typically comprise a rotatable handle disposed to the tank exterior, a flush lever disposed within the tank interior and a mechanical coupling disposed between the rotatable handle and the flush lever. The mechanical coupling extends through an aperture defined within a tank wall that separates the tank exterior and the tank interior, the tank interior comprising the vessel for storing that amount of water that is used to flush the toilet upon rotation of the aforementioned rotatable handle. Actuation of the flush lever is accomplished by pushing the end of the rotatable handle downwardly (or rearwardly depending on the handle's orientation), thereby lifting the flush lever about a central pivot point. All of this mechanical action relies essentially on gravity, the flush lever and flapper valve typically being heavier than the flush handle, and on the flotation of the flapper valve within the tank.
[0005] In the view of this inventor, there is a need to allow the flush lever and the rotatable handle to be mounted such that it can be operated in a number of different ways. For example, one operational position, the handle is a standard front left mount (as viewed by a user standing and facing the toilet bowl), with the handle being disposed in a horizontal position with handle rotation being downward. Another is the same type of mount, but where the horizontal handle is positioned on the left side of the tank, with handle rotation also being downward. Another is a standard angle mount where the handle is disposed in either a vertical or a horizontal position and can be pushed or pulled depending on the internal configuration of the toilet tank. In any one of the operational positions, it would be desirable that the lever consistently return to its default or neutral position irrespective of the orientation of the handle relative to the tank. That is, it would be desirable to provide a “dual action” for the handle whereby rotation of the handle in two different directions always results in the handle returning to its default position, i.e. horizontal or vertical.
[0006] There is also a need for such a handle and flush lever such that one portion of the flush lever can be variably adjustable within 360° of rotation and by adjustments every 15° for optimal placement of the flush lever as desired or required. Lastly, there is also a need to provide another portion of the flush lever that can be variably adjustable within 180° of rotation and by adjustments also every 15°. Such would allow the wide variety of handle placements as discussed above.
SUMMARY OF THE INVENTION
[0007] In accordance with the foregoing, an improved flush lever has been devised by this inventor which accomplishes the goals identified above. As used in this disclosure, the term “flush lever” means the exterior handle, the interior lever and the interposed mechanical coupling. It is also to be understood that use of the improved flush lever with a conventional water tank, for purposes of this disclosure, comprises an “assembly.”
[0008] More specifically, the flush lever of the present invention comprises a handle and a skirt, or escutcheon plate, both disposed to the exterior of the tank. Within the tank is a flush lever subassembly, the subassembly taking one of two different embodiments and each embodiment comprising means for mechanically linking the flush lever with the subassembly.
[0009] One embodiment uses a semi-metallic handle and skirt, the semi-metallic handle and skirt having a die cast configuration. In that embodiment, it is to be understood that the semi-metallic structures could be made of brass, aluminum or zinc using the die case process. A second embodiment uses a plastic handle and skirt, the plastic handle being attached by means of a “snap on” configuration such that the handle becomes non-removable once assembled, or snapped on. Further, the plastic chosen for the handle and skirt of the second embodiment can be molded in virtually any color and the plastic chosen can also be painted by the end user to accommodate the user's liking or decor. Each embodiment uses other components, many of which are common to both.
[0010] The foregoing and other features of the flush lever and the assembly of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] FIG. 1 is a top plan view of a first preferred embodiment of a flush lever constructed in accordance with the present invention.
[0012] FIG. 2 is a cross sectioned view of the flush lever shown in FIG. 1 .
[0013] FIG. 3 is a cross sectioned view of a portion of the flush lever taken along line B-B of FIG. 1 .
[0014] FIG. 4 is an enlarged front elevation view of a portion of the flush lever.
[0015] FIG. 5 is a cross sectioned view similar to that shown in FIG. 2 , but of a second preferred embodiment of the present invention.
DETAILED DESCRIPTION
[0016] Referring now to the drawings in detail, wherein like-numbered elements refer to like elements throughout, FIG. 1 illustrates a top plan view of a first preferred embodiment of the flush lever, generally identified 10 , of the present invention, which flush lever 10 is the type that would be mounted within a toilet tank (not shown). As shown, the flush lever 10 comprises a tank handle 20 , a “skirt” or escutcheon plate 30 , a connector or “tank handle stop” 40 , an adapter 50 , a nut 60 , a lock pin 70 , a “segment” or connecting arm 80 , and a lever 90 .
[0017] The connecting arm 80 has 360° of rotation and can be adjusted every 15°. The connecting arm 80 is held in place by a retention clip 87 . See also FIG. 2 . This retention clip 87 must be removed to adjust the position of the connecting arm 80 . On an end of the connecting arm 80 , there is a holder for the clip 87 so that it does not get lost. Similarly, the lever 90 has 180° of rotation and can be adjusted every 15° as well. The lever 90 is held in place by a retention clip 97 as well. This retention clip 97 must be removed to adjust the position of the lever 90 .
[0018] In this first configuration, the tank handle 20 and the skirt 30 are made of a semi-metallic alloy, which is a first preferred embodiment. Again, in this first embodiment, it is to be understood that the semi-metallic structures could be made of brass, aluminum or zinc using the die case process.
[0019] FIG. 5 illustrates the plastic counterpart 110 of the present invention. This is a second preferred embodiment and its components are slightly different, but not completely, and will be discussed in further detail below.
[0020] Referring specifically now to FIG. 2 , it shows a cross-section of the flush lever 10 shown in FIG. 1 . As shown, the tank handle 20 comprises a proximal handle portion 22 , a distal handle portion 24 and an annular ring 26 disposed about the proximal handle portion 22 , but separated from the proximal handle portion 22 by an annular gap 25 . The proximal handle portion 22 further comprises a shaft 27 that extends inwardly and has an aperture 29 defined in the distal end 28 of the shaft 27 . Again, in this first embodiment, the tank handle 20 and its component parts are preferably made of a single piece of semi-metallic alloy material.
[0021] Moving inwardly (since the tank handle 20 is intended to be disposed to the exterior of the water tank), it will be seen that an escutcheon or skirt 30 is provided (or, simply, skirt). This skirt 30 comprises a centrally disposed portion 32 having an aperture 31 defined in it. Moving outwardly from the centrally disposed portion 32 , it will be seen that the skirt 30 further comprises an outwardly extending annular ring 35 , which ring 35 is functionally adapted to fit within the annular gap 25 of the handle 20 . This structure maintains the general alignment between the handle 20 and the skirt 30 . Moving outwardly from the center of the skirt 30 , it will be seen that the skirt 30 further comprises a pair of inwardly extending annular arcs 36 and a contoured inwardly extending annular ring 38 . An annular space 39 is disposed between those two structures 36 , 38 . The contoured annular ring 38 is that portion of the skirt 30 that is visible to the user and is also disposed at the outer surface of the water tank (not shown). Again, in this first embodiment, the skirt 30 and its component elements are preferably made of a single piece of semi-metallic alloy material.
[0022] Extending from the tank exterior to the tank interior is a centrally disposed connector 40 , which is also referred to herein as a “tank handle stop.” This tank handle stop or connector 40 comprises a central portion 42 having an aperture 41 defined axially within it. At a first end 44 of the connector 40 , which first end 44 extends outwardly of the water tank, a first annular ring 46 is provided as is a second annular ring 48 , although the second annular ring 48 is not a complete ring—it is interrupted, as is shown in FIG. 3 and discussed below. Further, where a portion of the second annular ring 48 is nonexistent, there is instead a spring rotational stop 49 ; again, see FIG. 3 . The diameter of the second annular ring 48 is greater than that of the first annular ring 46 . As shown, the first annular ring 46 creates a cavity 47 between it and the first inwardly extending annular ring 36 of the skirt 30 . The second annular ring 48 is disposed within the annular space 39 created between the arcs 36 and ring 38 of the skirt 30 . Inwardly of the connector 40 (relative to the water tank), an outer threaded portion 45 is provided. This threaded portion 45 is provided such that a like-threaded nut 60 can secure the connector 40 to the wall of the water tank from the interior side of the wall.
[0023] Disposed opposite the nut 60 is a circumferential adapter 50 which allows a tight and water-proof connection of the flush lever 10 to the water tank wall. This adapter 50 is preferably made of rubber and is designed to adapt to the smallest and largest square hole in the tank wall. This allows the assembly (i.e. the lever 10 together with the tank) to remain located in its tightened position which is critical to opening the flapper properly and consistently. Further, the adapter 50 acts as a spring washer when under compression. Accordingly, the use of a low compression set rubber is key to this preferred embodiment.
[0024] At the distal end 28 of the handle shaft 27 is a lock pin 70 having a first centrally disposed aperture 72 and a second centrally disposed aperture 74 , the diameter of the latter being smaller than that of the former. In this way, a self-tapping screw 75 can be introduced to the handle shaft 27 via the first centrally disposed aperture 72 and the screw 75 can be secured within the second aperture 74 to secure the handle 20 to the lock pin 70 . The lock pin 70 further comprises a circumferential notch 77 about its upper perimeter 76 . The notch 77 is used to receive a retention clip 87 that attaches a proximal portion 82 of the “segment” 80 (which is effectively a 90° elbow) to the lock pin 70 . One of the key features of the preferred embodiment is that this connecting arm 80 has 360° rotation and can be adjusted every 15° to achieve a desired positioning. The connecting arm 80 is held in place by the retention clip 87 . The clip 87 must be removed to adjust the positioning of the connecting arm 80 . Further, on the proximal portion 82 of the connecting arm 80 is a holder for the clip 87 so that the clip 87 does not get lost.
[0025] As shown in FIG. 2 , the connecting arm 80 also comprises a distal portion 84 to which is attached the flush lever 90 , the lever 90 having a number of lever holes 92 to allow all types of lanyards, loop chains and beaded chains (not shown) that are connected to a flapper (also not shown) that is disposed at the bottom of the water tank. See FIG. 4 . More significantly, the lever 90 also has 180° of rotation and it can be adjusted every 15° as well. The lever 90 is likewise held in place by a retention clip 97 . The retention clip 97 must also be removed to adjust the lever 90 .
[0026] Referring specifically now to FIG. 3 , it shows a cross-section of the skirt 30 and connector 40 taken along line B-B of FIG. 1 wherein an additional significant functional feature of the present invention is illustrated. Specifically, a spring 100 is assembled to the tank handle stop 40 . When the spring 100 is so assembled, it has a small amount of preload on it. This allows the lever 90 to return consistently back to the neutral position. As shown in FIG. 3 , the spring 100 comprises two ends 102 each of which is held to movement within only a portion of the skirt 30 and the tank handle stop 40 . As previously alluded to, a spring rotational stop 49 is also provided.
[0027] Referring to FIG. 5 , it shows a cross sectioned view of the structure 110 of the second preferred embodiment of the present invention. The differences in structure are that the handle 120 and skirt 130 are snap fitted together. Prior to snap fitting the handle 120 , a self-tapping screw 102 is inserted into one end of a much longer lock pin 170 to secure the connecting arm 180 and lever 190 to the structure 110 . Once snapped into place, the handle 120 is not intended to be removed. In all other respects, the functionality of the second embodiment is substantially similar to that of the first embodiment.
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A flush lever comprises a handle and a skirt, or escutcheon plate, both disposed to the exterior of a toilet tank. Within the tank is a flush lever subassembly, the subassembly taking one of two different embodiments and each embodiment comprising means for mechanically linking the flush lever with the subassembly. One portion of the flush lever can be variably adjustable within 360° of rotation and by adjustments every 15° for optimal placement of the flush lever as desired or required. Another portion of the flush lever can be variably adjustable within 180° of rotation as well and by adjustments also every 15°.
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TECHNICAL FIELD
The present invention relates to a digital frequency/phase locked loop (FLL: Frequency Locked Loop, PLL: Phase Locked Loop) used in a wireless communication device or the like, and, more specifically, relates to a digital FLL/PLL that converges an oscillation frequency to a desired frequency at a high speed on the basis of a signal error that is the difference between a channel signal and the oscillation frequency.
BACKGROUND ART
In recent years, with technology of wireless LAN, third-generation mobile phone, digital broadcasting, and the like, digitalized communication/broadcasting has a purpose of switching the frequency of a channel signal. As a method for converging a frequency outputted from a wireless communication device or the like to the frequency of a channel signal when switching the frequency of the channel signal as described above, technology using a digital FLL/PLL is known.
FIG. 12 is a diagram illustrating a digital FLL 900 in the conventional art. In FIG. 12 , the digital FLL 900 includes a frequency comparator 910 , an FIR filter 920 , an IIR filter 930 , a digital-analogue convertor (DAC) 940 , a voltage-controlled oscillator (VCO) 950 , and a frequency-digital convertor 960 .
The frequency comparator 910 compares a channel signal D_ref inputted to the digital FLL 900 to a loopback signal D_vco and outputs a frequency error signal D_error between the channel signal D_ref and the loopback signal D_vco. The FIR filter 920 and the IIR filter 930 output a control voltage signal D_vtune on the basis of the frequency error D_error outputted from the frequency comparator 910 .
Here, the FIR filter 920 includes first to third delay blocks Z -1 921 to 923 , first and second adders 924 and 925 , and a multiplier 926 having a fixed multiplying factor of ⅓. The FIR filter 920 performs a moving average process on the frequency error D_error by using the third delay blocks Z -1 921 to 923 . In addition, the IIR filter 930 includes first and second multipliers 931 and 933 , first and second adders 932 and 934 , and a delay block Z -1 935 . An output of the FIR filter 920 is inputted to the first multiplier 931 and the first adder 932 of the IIR filter 930 . The first multiplier 931 multiplies the output of the FIR filter 920 by a weighting factor β. The first adder 932 adds an output of the second multiplier 933 to the output of the FIR filter 920 . The second multiplier 933 multiplies an output of the first adder 932 looped back via the delay block Z -1 935 , by a weighting factor α. The second adder 934 sums an output of the first multiplier 931 and an output of the first adder 932 , and outputs the summed output as the control voltage signal D_vtune to the DAC 940 .
The control voltage signal D_vtune is analogue-converted by the DAC 940 and then inputted to the VCO 950 . The VCO 950 controls an oscillation frequency fout outputted from the VCO 950 , on the basis of the inputted control voltage signal. The oscillation frequency fout generated by the VCO 950 is digital-converted by the frequency-digital convertor 960 and returns as the loopback signal D_vco to the frequency comparator 910 .
In this manner, the digital FLL 900 generates the control voltage signal D_vtune on the basis of the frequency error signal D_error between the channel signal D_ref and the loopback signal D_vco, and further controls the oscillation frequency fout outputted from the VCO 950 , on the basis of the control voltage signal D_vtune.
FIG. 13 is a diagram illustrating a situation where the oscillation frequency fout from the VCO 950 of the digital FLL 900 in the conventional art converges to a desired frequency. In FIG. 13 , between times t 0 and t 1 , the reference frequency of the channel signal D_ref and the oscillation frequency fout from the VCO 950 are in a stationary state at the same frequency f 1 .
When the frequency of the channel signal D_ref is switched from f 1 to f 2 at time t 1 , the oscillation frequency fout from the VCO 950 does not instantly come into a stationary state at the frequency f 2 . The oscillation frequency fout from the VCO 950 converges to the desired frequency f 2 with repeated vibrations, and substantially comes into a stationary state at time t 3 .
The reason why the oscillation frequency fout from the VCO 950 converges to the desired frequency f 2 with repeated vibrations as described above is that due to group delays of the FIR filter 920 and the IIR filter 930 , the frequency error signal D_error is not instantly transferred.
FIG. 14A is a diagram illustrating the frequency error signal D_error that is an output from the frequency comparator 910 , D_FIR that is an output from the FIR filter 920 , and D_IIR_B that is an output from the first multiplier 931 of the IIR filter 930 . FIG. 14B is a diagram illustrating D_IIR_A that is an output from the first adder 932 of the IIR filter 930 , and D_IIR_C that is an output from the second multiplier 933 of the IIR filter 930 . Hereinafter, timings of operations of the digital FLL 900 will be described with reference to FIGS. 14A and 14B .
Between times t 0 and t 1 between which the oscillation frequency fout from the VCO 950 is in a stationary state at the frequency f 1 , the frequencies of the frequency error signal D_error, D_FIR, and D_IIR_B are in a stationary state at 0 in FIG. 14A , and the frequencies of D_IIR_A and D_IIR_C are in a stationary state at f 1 in FIG. 14B .
Here, when the frequency of the channel signal D_ref is switched from f 1 to f 2 at time t 1 , the frequency of D_error rapidly falls to near —(f 1 -f 2 ) in FIG. 14A . This is because the frequency of the channel signal D_ref is switched to f 2 at time t 1 but the frequency of the oscillation frequency fout does not instantly become f 2 . The frequency difference between the channel signal D_ref and the loopback signal D_vco based on the oscillation frequency fout becomes about —(f 1 -f 2 ), and the frequency comparator 910 outputs a frequency error signal D_error having a frequency of —(f 1 -f 2 ).
Then, the FIR filter 920 outputs D_FIR on the basis of the frequency error D_error outputted from the frequency comparator 910 . In FIG. 14A , D_FIR delays from D_error. This is due to the delay properties of the FIR filter 920 (the third delay blocks Z -1 921 to 923 and the like). Further, D_FIR is multiplied by the weighting factor β by the first multiplier 931 of the IIR filter 930 and outputted as D_IIR_B. Here, the weighting factor β=0.3.
Further, when the frequency of the channel signal D_ref is switched from f 1 to f 2 at time t 1 , the frequency of D_IIR_A falls from f 1 to f 2 slightly after time t 1 in FIG. 14B . This is because D_IIR_A is obtained by adding the output of the second multiplier 933 to D_FIR, which is the output of the FIR filter 920 , and thus influenced by the above delay properties of the FIR filter 920 . Then, D_IIR_C is obtained by looping back the above D_IIR_A via the delay block Z -1 935 and multiplying D_IIR_A by the weighting factor α by the second multiplier 933 of the IIR filter 930 , and thus further delays from D_IIR_A. Here, the weighting factor α=1.0.
As described above, according to the digital FLL 900 , when the frequency of the channel signal D_ref is switched from f 1 to f 2 at time t 1 , due to the group delays of the FIR filter 920 and the IIR filter 930 , the frequency error signal D_error is not instantly transferred, and the oscillation frequency fout from the VCO 950 converges to the desired frequency f 2 while repeatedly vibrating in a regular attenuation vibration cycle T (=1/ωn (ωn: natural frequency). In other words, in the digital FLL 900 , it takes a certain time (time t 3 −time t 1 ) until the oscillation frequency fout from the VCO 950 converges to the desired frequency f 2 . The above conventional art is disclosed, for example, in Non-Patent Literature 1.
CITATION LIST
[Non Patent Literature]
[NPL 1] Dean Banerjee, “PLL Performance, Simulation, and Design 4th Edition”, [online], [searched on Jan. 28, 2009], Internet <http://www.national.com/appinfo/wireless/files/deansbook4.pdf>.
SUMMARY OF THE INVENTION
Problems to be Solved by the Invention
Here, when the natural frequency (on is increased by reducing the operation load of the digital filter (the FIR filter 920 and the IIR filter 930 ) only when switching the frequency of the channel signal D_ref, the attenuation vibration cycle T becomes low, and thus the oscillation frequency fout from the VCO 950 can be converged to the desired frequency at a high speed.
However, when the VCO gain varies, it is necessary to adjust the natural frequency ωn by setting a damping factor corresponding to each VCO gain. In other words, a desired natural frequency ωn is not obtained unless the damping factor is corrected as appropriate by using the actual measured value of each VCO gain. Thus, when converging the oscillation frequency from the VCO to the desired frequency, the effect of speedup is not exerted at 100%.
Therefore, an object of the present invention is to provide a digital FLL/PLL that is capable of converging an oscillation frequency from a VCO to a desired frequency at a high speed even without setting a damping factor corresponding to each VCO gain.
Solution to the Problems
To achieve the above object, according to a first aspect of the present invention, a digital FLL/PLL or controlling an outputted oscillation frequency on the basis of a signal error that is a difference between an inputted channel signal and the oscillation frequency. The digital frequency/phase locked loop comprises: a comparator for comparing the channel signal to a loopback signal having the oscillation frequency to generate the signal error; a digital loop filter for generating a control voltage that determines the oscillation frequency, on the basis of the signal error; a VCO for controlling an oscillation frequency on the basis of the control voltage; a loopback path through which the oscillation frequency generated by the VCO is outputted as the loopback signal to the comparator; and a control section for monitoring the signal error generated by the comparator, and controlling the digital loop filter such that the oscillation frequency of the VCO comes into a stationary state, when detecting that the signal error is within a predetermined range based on 0 after the channel signal is switched.
Further, the control section may monitor the signal error generated by the comparator, and may control the digital loop filter such that the oscillation frequency of the VCO comes into a stationary state, when detecting that the absolute value of the signal error is minimum after the channel signal is switched.
Further, the control section may monitor a temporal average of the signal error generated by the comparator. Further, the control section may control the digital loop filter by using a temporal average of the control voltage generated by the digital loop filter.
Further, the control section may have a function to correct a delay time occurring between an input and an output of the loopback path.
Preferably, the digital loop filter includes an FIR filter and an IIR filter, and the control section sets 0 to a delay block of the FIR filter, and sets the control voltage generated by the digital loop filter to a delay block of the IIR filter.
Further, preferably, the loopback path includes a frequency-digital convertor that performs analogue-digital conversion on the oscillation frequency generated by the VCO.
Further, preferably, the digital frequency/phase locked loop further comprises: a subband selection circuit for controlling selection of a subband in which the VCO oscillates at a desired frequency; and a switch, provided between the digital loop filter and the VCO, for switching between inputs of the control voltage generated by the digital loop filter and a control voltage from the subband selection circuit. The subband selection circuit fixes a control voltage inputted to the VCO, during the selection of the subband, and changes the control voltage inputted to the VCO, after the selection of the subband. The switch switches to connect the subband selection circuit to the VCO, at start of the selection of the subband, and switches to connect the digital loop filter to the VCO, when the oscillation frequency of the VCO comes into a stationary state.
Further, the digital frequency/phase locked loop may further comprise a DAC for performing digital-analogue conversion on the control voltage generated by the digital loop filter.
To achieve the above object, a second aspect of the present invention applies the digital FLL/PLL described above by incorporating the digital FLL/PLL into a wireless communication device or the like.
Advantageous Effects of the Invention
As described above, according to the present invention, the digital loop filter is controlled into a stationary state on the basis of the signal error, thereby implementing a digital FLL/PLL that is capable of converging the oscillation frequency from the VCO to a desired frequency at a high speed. In other words, the present invention does not converge the oscillation frequency from the VCO to a desired frequency at a high speed by adjusting the natural frequency ωn to decrease the attenuation vibration cycle T. Thus, even when the VCO gain varies, the present invention can converge the oscillation frequency from the VCO to a desired frequency at a high speed without making correction to a damping factor corresponding to each VCO gain. It should be noted that when a stationary state is provided in a short time after the frequency of the channel signal is switched, each device can be set in a sleep mode and thus reduction of current consumption can be achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a digital FLL 100 according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating a situation where an oscillation frequency fout from a VCO 150 of the digital FLL 100 according to the first embodiment of the present invention converges to a desired frequency.
FIG. 3 is a flowchart illustrating an operation of a control section 170 of the digital FLL 100 according to the first embodiment of the present invention.
FIG. 4A is a diagram illustrating a frequency error signal D_error that is an output from a frequency comparator 110 , D_FIR that is an output from an FIR filter 120 , and D_IIR_B that is an output from a first multiplier 131 of an IIR filter 130 .
FIG. 4B is a diagram illustrating D_IIR_A that is an output from a first adder 132 of the IIR filter 130 , and D_IIR_C that is an output from a second multiplier 133 of the IIR filter 130 .
FIG. 4C is a diagram representing the absolute value of the frequency error signal D_error illustrated in FIG. 4A .
FIG. 4D is a diagram illustrating a digital FLL 100 b according to the first embodiment of the present invention.
FIG. 4E is a diagram illustrating a digital FLL 100 c according to the first embodiment of the present invention.
FIG. 5 is a diagram illustrating a digital FLL 200 according to a second embodiment of the present invention.
FIG. 6 is a diagram illustrating a situation where an oscillation frequency fout from a VCO 150 of the digital FLL 200 according to the second embodiment of the present invention converges to a desired frequency.
FIG. 7 is a flowchart illustrating an operation of the digital FLL 200 according to the second embodiment of the present invention.
FIG. 8A is a diagram illustrating relationships between a control voltage inputted to the VCO 150 and an oscillation frequency when subbands (N−1) to (N+2) are selected.
FIG. 8B is a diagram illustrating a digital FLL 200 b according to the second embodiment of the present invention.
FIG. 8C is a diagram illustrating a digital FLL 200 c according to the second embodiment of the present invention.
FIG. 9A is a diagram illustrating a digital PLL 300 according to a third embodiment of the present invention.
FIG. 9B is a diagram illustrating a digital PLL 300 b according to the third embodiment of the present invention.
FIG. 9C is a diagram illustrating a digital PLL 300 c according to the third embodiment of the present invention.
FIG. 10 is a diagram illustrating a polar modulation circuit 400 according to a fourth embodiment of the present invention.
FIG. 11 is a diagram illustrating a wireless communication device 500 according to a fifth embodiment of the present invention.
FIG. 12 is a diagram illustrating a digital FLL 900 in the conventional art.
FIG. 13 is a diagram illustrating a situation where an oscillation frequency fout from a VCO 950 of the digital FLL 900 in the conventional art converges to a desired frequency.
FIG. 14A is a diagram illustrating a frequency error signal D_error that is an output from a frequency comparator 910 , D_FIR that is an output from an FIR filter 920 , and D_IIR_B that is an output from a first multiplier 931 of an IIR filter 930 .
FIG. 14B is a diagram illustrating D_IIR_A that is an output from a first adder 932 of the IIR filter 930 , and D_IIR_C that is an output from a second multiplier 933 of the IIR filter 930 .
DESCRIPTION OF EMBODIMENTS
Hereinafter, each embodiment of the present invention will be described with reference to the drawings.
(First Embodiment)
FIG. 1 is a diagram illustrating a digital FLL 100 according to a first embodiment of the present invention. In FIG. 1 , the digital FLL 100 includes a frequency comparator 110 , an FIR filter 120 , an IIR filter 130 , a VCO 150 , a frequency-digital convertor 160 , and a control section 170 . The digital FLL 100 according to the first embodiment of the present invention is typically applied to a frequency synthesizer.
The frequency comparator 110 compares a channel signal D_ref inputted to the digital FLL 100 to a loopback signal D_vco and outputs a frequency error signal D_error between the channel signal D_ref and the loopback signal D_vco. The FIR filter 120 and the IIR filter 130 output a control voltage signal D_vtune on the basis of the frequency error D_error outputted from the frequency comparator 110 .
Here, the FIR filter 120 includes first to third delay blocks Z -1 121 to 123 , first and second adders 124 and 125 , and a multiplier 126 having a fixed multiplying factor of ⅓. The FIR filter 120 performs a moving average process on the frequency error D_error by using the first to third delay blocks Z -1 121 to 123 . Further, the IIR filter 130 includes first and second multipliers 131 and 133 , first and second adders 132 and 134 , and a delay block Z -1 135 .
An output of the FIR filter 120 is inputted to the first multiplier 131 and the first adder 132 of the IIR filter 130 . The first multiplier 131 multiplies the output of the FIR filter 120 by a weighting factor β. The first adder 132 adds an output of the second multiplier 133 to the output of the FIR filter 120 . The second multiplier 133 multiplies an output of the first adder 132 looped back via the delay block Z -1 135 , by a weighting factor α. The second adder 134 sums an output of the first multiplier 131 and an output of the first adder 132 , and outputs the summed output as the control voltage signal D_vtune.
The control voltage signal D_vtune is inputted to the VCO 150 . The VCO 150 controls an oscillation frequency fout outputted from the VCO 150 , on the basis of the inputted control voltage signal. Here, a loopback path through which the oscillation frequency fout generated by the VCO 150 is looped back to the frequency comparator 110 includes the frequency-digital convertor 160 . The oscillation frequency fout generated by the VCO 150 is digital-converted by the frequency-digital convertor 160 and returns as the loopback signal D_vco to the frequency comparator 110 .
In this manner, the digital FLL 100 generates the control voltage signal D_vtune on the basis of the frequency error signal D_error between the channel signal D_ref and the loopback signal D_vco, and further controls the oscillation frequency fout outputted from the VCO 150 , on the basis of the control voltage signal D_vtune.
The configuration and the operation of the digital FLL 100 described so far are the same as the configuration and the operation of the digital FLL 900 in the conventional art. The digital FLL 100 according to the first embodiment of the present invention further includes the control section 170 . Hereinafter, the difference between the digital FLL 100 according to the first embodiment of the present invention and the digital FLL 900 in the conventional art will be described in detail with a description concerning an operation of the control section 170 .
FIG. 2 is a diagram illustrating a situation where the oscillation frequency fout from the VCO 150 of the digital FLL 100 according to the first embodiment of the present invention converges to a desired frequency. In FIG. 2 , between times t 0 and t 1 , the reference frequency of the channel signal D_ref and the oscillation frequency fout from the VCO 150 are in a stationary state at the same frequency f 1 .
When the frequency of the channel signal D_ref is switched from f 1 to f 2 at time t 1 , the oscillation frequency fout from the VCO 150 does not instantly come into a stationary state at the frequency f 2 . However, the oscillation frequency fout from the VCO 150 does not converge to the desired frequency f 2 with repeated vibrations, as illustrated in FIG. 13 , between times t 2 and t 3 , but substantially comes into a stationary state at the desired frequency f 2 at time t 2 . This is because at time t 2 , the control section 170 controls the FIR filter 120 and the IIR filter 130 on the basis of the frequency error signal D_error.
FIG. 3 is a flowchart illustrating the operation of the control section 170 of the digital FLL 100 according to the first embodiment of the present invention. Further, FIG. 4A is a diagram illustrating the frequency error signal D_error that is an output from the frequency comparator 110 , D_FIR that is an output from the FIR filter 120 , and D_IIR_B that is an output from the first multiplier 131 of the IIR filter 130 . FIG. 4B is a diagram illustrating D_IIR_A that is an output from the first adder 132 of the IIR filter 130 , and D_IIR_C that is an output from the second multiplier 133 of the IIR filter 130 . Hereinafter, timings of operations of the digital FLL 100 will be described with reference to FIGS. 3 , 4 A, and 4 B.
Between times t 0 and t 1 between which the oscillation frequency fout from the VCO 150 is in a stationary state at the frequency f 1 , the frequencies of the frequency error signal D_error, D_FIR, and D_IIR_B are in a stationary state at 0 in FIG. 4A , and the frequencies of D_IIR_A and D_IIR_C are in a stationary state at f 1 in FIG. 4B . This is the same as the stationary state illustrated in FIGS. 14A and 14B .
In FIG. 3 , when the frequency of the channel signal D_ref is switched from f 1 to f 2 (at time t 1 in FIG. 2 ), the control section 170 starts a process for converging the oscillation frequency fout from the VCO 150 , to a desired frequency at a high speed. Then, the control section 170 executes steps S 101 to S 104 in order.
At step S 101 , the control section 170 monitors the frequency error signal D_error, which is from the frequency comparator 110 . When the frequency error signal D_error does not meet a predetermined condition, the control section 170 continues to monitor the frequency error signal D_error (No at step S 102 ). It should be noted that between times t 1 and t 2 , in FIG. 4A , D_error, D_FIR, and D_IIR_B exhibit the same characteristics as those in FIG. 14A , and in FIG. 4B , D_IIR_A and D_IIR_C exhibit the same characteristics as those in FIG. 14B .
When the frequency error signal D_error meets the predetermined condition after the frequency of the channel signal D_ref is switched from f 1 to f 2 , namely, when the control section 170 detects that the frequency error signal D_error meets the predetermined condition after starting the monitoring of the frequency error signal D_error, the control section 170 proceeds to a process at step S 103 (Yes at step S 102 ). At step S 103 , the control section 170 obtains the control voltage signal D_vtune, which is the output from the IIR filter 130 , and proceeds to a process at step S 104 .
Here, the control section 170 can determine whether or not the frequency error signal D_error meets the predetermined condition, on the basis of whether or not the frequency error signal D_error is 0. In other words, when the frequency error signal D_error is not 0 such as between times t 1 and t 2 in FIG. 2 , the control section 170 continues to monitor the frequency error signal D_error (No at step S 102 ). When the control section 170 detects that the frequency error signal D_error is 0 after starting the monitoring of the frequency error signal D_error (e.g., at time t 2 in FIG. 4A ), the control section 170 proceeds to the process at step S 103 (Yes at step S 102 ).
Alternatively, the control section 170 may detect whether or not the frequency error signal D_error meets the predetermined condition, on the basis of whether or not the frequency error signal D_error is within a predetermined range based on 0. It should be noted that the predetermined range based on 0 is preferably close to 0. In this case, when the control section 170 detects that the frequency error signal D_error is within the predetermined range based on 0 after starting the monitoring of the frequency error signal D_error, the control section 170 advances the processing to step S 103 (Yes at step S 102 ). This is for assuredly advancing the operation to steps subsequent to the step S 103 even when the frequency error signal D_error does not completely become 0 due to reasons of digital signal processing.
Alternatively, the control section 170 may detect whether or not the frequency error signal D_error meets the predetermined condition, on the basis of whether or not the absolute value of the frequency error signal D_error is minimum. FIG. 4C is a diagram representing the absolute value of the frequency error signal D_error illustrated in FIG. 4A . FIG. 4C illustrates the case where the absolute value of the frequency error signal D_error reaches minimum at time t 2 . When the control section 170 detects that the absolute value of the frequency error signal D_error is minimum after starting the monitoring of the frequency error signal D_error (e.g., at time t 2 in FIG. 4C ), the control section 170 advances the processing to step S 103 (Yes at step S 102 ).
At step S 104 , the control section 170 sets 0 to the first to third delay blocks Z -1 121 to 123 of the FIR filter 120 , and sets the control voltage signal D_vtune obtained at step S 103 to the delay block Z -1 135 of the IIR filter 130 . By so doing, at time t 2 , the frequencies of D_FIR and D_IIR_B become 0 in FIG. 4A , and the frequencies of D_IIR_A and D_IIR_C become f 2 in FIG. 4A .
Here, the FIR filter 120 and the IIR filter 130 of the digital FLL 100 according to the first embodiment of the present invention will be compared to the FIR filter 920 and the IIR filter 930 of the digital FLL 900 in the conventional art. At step S 104 , the control section 170 sets 0 to the first to third delay blocks Z -1 121 to 123 of the FIR filter 120 , and sets the control voltage signal D_vtune obtained at step S 103 to the delay block Z -1 135 of the IIR filter 130 , whereby at time t 2 , the FIR filter 120 and the IIR filter 130 of the digital FLL 100 according to the first embodiment of the present invention come into a state that is the same as that at time t 3 of the FIR filter 920 and the IIR filter 930 of the digital FLL 900 in the conventional art (see FIG. 13 ).
Therefore, the oscillation frequency fout from the VCO 150 of the digital FLL 100 according to the first embodiment of the present invention does not converge to the desired frequency f 2 with repeated vibrations as illustrated in FIG. 13 , between times t 2 and t 3 , but substantially comes into a stationary state at the desired frequency f 2 at time t 2 .
As described above, according to the digital FLL 100 according to the first embodiment of the present invention, at time t 2 when the control section 170 detects that the frequency error signal D_error meets the predetermined condition, the control section 170 controls the digital loop filter into a stationary state (a state at time t 3 in FIG. 13 ), whereby the oscillation frequency fout from the VCO 150 can be converged to the desired frequency at a high speed.
Further, according to the digital FLL 100 according to the first embodiment of the present invention, a stationary state is provided in a short time after the frequency of the channel signal is switched, and thus each device can be set in a sleep mode and reduction of current consumption can be achieved.
Further, in order to maximally exert the effects of the present invention, the digital FLL 100 may operate, for example, as follows. At step S 101 in FIG. 3 , the control section 170 monitors the frequency error signal D_error, which is from the frequency comparator 110 . At that time, the control section 170 may use a temporal average of the frequency error signal D_error for monitoring the frequency error signal D_error. By so doing, the control section 170 can reduce the influence of a noise component included in the frequency error signal D_error, when monitoring the frequency error signal D_error.
Further, at step S 103 in FIG. 3 , similarly, the control section 170 may use a temporal average of the control voltage signal D_vtune for obtaining the control voltage signal D_vtune. By so doing, the control section 170 can reduce the influence of the noise component included in the control voltage signal D_vtune, when obtaining the control voltage signal D_vtune.
By using the temporal average of at least either one of the frequency error signal D_error or the control voltage signal D_vtune as described above, the control section 170 can set a value that reduces the influence of the noise component, at step S 104 .
Further, in the example described above, the control section 170 calculates the temporal averages of the frequency error signal D_error and the control voltage signal D_vtune. However, a component other than the control section 170 may calculate them. In this case, the digital FLL circuit 100 may be configured to further include, for example, at least either one of an averaging section 180 or an averaging section 190 as in a digital FLL 100 b illustrated in FIG. 4D . The averaging section 180 calculates a temporal average of the frequency error signal D_error outputted from the frequency comparator 110 , and outputs the temporal average to the control section 170 . The averaging section 190 calculate a temporal average of the control voltage signal D_vtune, and outputs the temporal average to the control section 170 .
It should be noted that since the influence of the noise component is reduced as described above, it is effective to calculate the temporal averages of the frequency error signal D_error and the control voltage signal D_vtune. However, if the timing of determining at step S 102 whether or not the predetermined condition is met and the timing of obtaining the control voltage signal D_vtune at step S 103 are out of synchronization with each other, the effects of the present invention are reduced. Thus, the frequency error signal D_error and the control voltage signal D_vtune are desirably temporally averaged at the same level.
Further, for the timing of obtaining the control voltage signal D_vtune at step S 103 , it is desirable to take into consideration a delay time occurring at the frequency-digital convertor 160 . In other words, the control section 170 desirably has a function to correct a delay time occurring between an input and an output of the loopback path.
Further, the digital FLL 100 according to the first embodiment may be configured to further include a DAC 140 as in a digital FLL 100 c illustrated in FIG. 4E . The DAC 140 performs digital-analogue conversion on the control voltage signal D_vtune generated by the IIR filter 130 , and outputs the resultant signal to the VCO 150 .
Further, other than the frequency synthesizer, the digital FLL 100 according to the first embodiment of the present invention may be applied to a frequency modulation circuit. The frequency modulation circuit performs frequency modulation on an inputted modulation signal, and outputs the resultant signal as a frequency modulation signal.
(Second Embodiment)
FIG. 5 is a diagram illustrating a digital FLL 200 according to a second embodiment of the present invention. In FIG. 5 , the digital FLL 200 includes a frequency comparator 110 , an FIR filter 120 , an IIR filter 130 , a VCO 150 , a frequency-digital convertor 160 , a control section 170 , a switch 210 , and a subband selection circuit 220 . The digital FLL 200 according to the second embodiment of the present invention differs from the digital FLL 100 according to the first embodiment of the present invention in including the switch 210 between the IIR filter 130 and the VCO 150 and in including the subband selection circuit 220 for selecting a subband. In FIG. 5 , the same components as those in FIG. 1 are designated by the same reference characters, and the detailed description thereof is omitted. In the present embodiment, the difference from the digital FLL 100 according to the first embodiment of the present invention will be described in detail.
FIG. 9 is a diagram illustrating a situation where an oscillation frequency fout from the VCO 150 of the digital FLL 200 according to the second embodiment of the present invention converges to a desired frequency. In FIG. 6 , between times t 0 and t 1 , the reference frequency of a channel signal D_ref and the oscillation frequency fout from the VCO 150 are in a stationary state at the same frequency f 1 .
When the frequency of the channel signal D_ref is switched from f 1 to f 2 at time t 1 , the oscillation frequency fout from the VCO 150 does not instantly come into a stationary state at the frequency f 2 , and substantially come into a stationary state at the desired frequency f 2 at time t 2 a . The digital FLL 200 performs subband selection between times t 1 and t 1 a and changes a control voltage to the VCO 150 between times t 1 a and t 2 a , thereby causing the frequency error signal D_error to approach 0.
FIG. 7 is a flowchart illustrating an operation of the digital FLL 200 according to the second embodiment of the present invention. In FIG. 7 , when the frequency of the channel signal D_ref is switched from f 1 to f 2 (at time t 1 in FIG. 6 ), the digital FLL 200 starts a process for converging the oscillation frequency fout from the VCO 150 , to a desired frequency at a high speed. Then, the digital FLL 200 executes steps S 201 to S 210 in order.
At step S 201 , the digital FLL 200 switches an input terminal of the switch 210 to the terminal A side to connect the subband selection circuit 220 to the VCO 150 .
At step S 202 , a lower bit outputted from the subband selection circuit 220 is fixed.
By steps S 201 and S 202 , the lower bit outputted from the subband selection circuit 220 is inputted as a control voltage signal to the VCO 150 via the switch 210 . Since the lower bit outputted from the subband selection circuit 220 is fixed at step S 202 , the control voltage signal inputted to the VCO 150 is also fixed.
At step S 203 , an upper bit outputted from the subband selection circuit 220 is changed, whereby subband selection is performed while a subband setting is changed. Here, the subband selection will be described. FIG. 8A is a diagram illustrating relationships between the control voltage inputted to the VCO 150 and an oscillation frequency when subbands (N−1) to (N+2) are selected. In the present embodiment, by fixing the lower bit outputted from the subband selection circuit 220 , the control voltage inputted to the VCO 150 is fixed, and the subband selection is performed. In FIG. 8A , for example, by fixing the control voltage inputted to the VCO 150 at Vo and changing the upper bit outputted from the subband selection circuit 220 , a subband in which the oscillation frequency is the desired frequency f 2 is searched for while the subband setting is changed. Examples of the method of searching for a subband include binary search.
As described above, by changing the upper bit outputted from the subband selection circuit 220 , the subband setting is repeatedly changed (No at step S 204 ), a subband N that meets that FN≦f 2 <F(N+1) is selected as illustrated in FIG. 8A (Yes at step S 204 , time t 1 a in FIG. 6 ).
At step S 205 , after the subband selection is completed (Yes at step S 204 ), the upper bit outputted from the subband selection circuit 220 is fixed.
At step S 206 , the lower bit outputted from the subband selection circuit 220 is changed to change the control voltage inputted to the VCO 150 .
The VCO 150 controls the oscillation frequency fout outputted from the VCO 150 , on the basis of the inputted control voltage signal. The oscillation frequency fout outputted from the VCO 150 is inputted as a loopback signal D_vco to the frequency comparator 110 via the frequency-digital convertor 160 . The frequency comparator 110 compares the channel signal D_ref to the loopback signal D_vco and outputs a frequency error signal D_error between the channel signal D_ref and the loopback signal D_vco.
In this manner, the lower bit outputted from the subband selection circuit 220 is changed to change the control voltage inputted to the VCO 150 and further to change the loopback signal D_vco. Thus, the frequency error signal D_error outputted from the frequency comparator 110 is also changed.
Similarly as described in the first embodiment of the present invention, the control section 170 monitors the frequency error signal D_error. When the frequency error signal D_error does not meet a predetermined condition, the lower bit outputted from the subband selection circuit 220 is changed such that the frequency error signal D_error approaches 0 (No at step S 207 ).
When the frequency error signal D_error meets the predetermined condition, namely, when the control section 170 detects that the frequency error signal D_error meets the predetermined condition, the control section 170 proceeds to a process at step S 208 (Yes at step S 207 ).
The control section 170 can determine whether or not the frequency error signal D_error meets the predetermined condition, similarly as in the first embodiment. For example, when the frequency error signal D_error is not 0 (between times t 1 a and t 2 a in FIG. 6 ), the control section 170 changes the lower bit outputted from the subband selection circuit 220 such that the frequency error signal D_error approaches 0 (No at step S 207 ). When the frequency error signal D_error is 0 (at time t 2 a in FIG. 6 ), namely, when the control section 170 detects that the frequency error signal D_error is 0, the control section 170 proceeds to the process at step S 208 (Yes at step S 207 ). Alternatively, the control section 170 may detect whether or not the frequency error signal D_error meets the predetermined condition, on the basis of whether or not the frequency error signal D_error is within a predetermined range based on 0 or whether or not the absolute value of the frequency error signal D_error is minimum.
At step S 208 , the control section 170 obtains the control voltage signal D_vtune that is an output from the IIR filter 130 , and proceeds to a process at step S 209 .
At step S 209 , the control section 170 sets 0 to first to third delay blocks Z -1 121 to 123 of the FIR filter 120 , and sets the control voltage signal D_vtune obtained at step S 103 to a delay block Z -1 135 of the IIR filter 130 .
At step S 210 , the digital FLL 200 switches the input terminal of the switch 210 to the terminal B side to connect the IIR filter 130 to the VCO 150 .
As described above, according to the digital FLL 200 according to the second embodiment of the present invention, after the subband selection is performed, the control voltage inputted to the VCO 150 is changed in order to cause the frequency error signal D_error to approach 0. At time t 2 a when the control section 170 detects that the frequency error signal D error meets the predetermined condition, the control section 170 controls the digital loop filter into a stationary state (the state at time t 3 in FIG. 13 ), whereby the oscillation frequency fout from the VCO 150 can be converged to the desired frequency at a high speed.
Further, according to the digital FLL 200 according to the second embodiment of the present invention, a stationary state is provided in a short time after the frequency of the channel signal is switched, and thus each device can be set in a sleep mode and reduction of current consumption can be achieved.
Similarly as in the first embodiment, the digital FLL circuit 200 according to the second embodiment may be configured to further include at least either one of an averaging section 180 or an averaging section 190 as in a digital FLL 200 b illustrated in FIG. 8B . The averaging section 180 calculates a temporal average of the frequency error signal D_error outputted from the frequency comparator 110 , and outputs the temporal average to the control section 170 . The averaging section 190 calculates a temporal average of the control voltage signal D_vtune, and outputs the temporal average to the control section 170 .
Further, the digital FLL 200 according to the second embodiment may be configured to further include a DAC 140 between the switch 210 and the VCO 150 as in a digital FLL 200 c illustrated in FIG. 8C . Hereinafter, an operation different from that in FIG. 7 when the digital FLL 200 b includes the DAC 140 will be described. At step S 201 , the digital FLL 200 b switches the input terminal of the switch 210 to the terminal A side to connect the subband selection circuit 220 to the DAC 140 . By steps S 201 and S 202 , the lower bit outputted from the subband selection circuit 220 is inputted to the DAC 140 via the switch 210 . The signal inputted to the DAC 140 is analogue-converted by the DAC 140 and then inputted as a control voltage signal to the VCO 150 .
(Third Embodiment)
The digital FLLs 100 and 200 described in the first and second embodiments of the present invention can be applied as a digital PLL used in a wireless communication device or the like.
FIG. 9A is a diagram illustrating a digital PLL 300 according to a third embodiment of the present invention. In FIG. 9A , the digital PLL 300 includes a phase comparator 310 , an FIR filter 120 , an IIR filter 130 , a VCO 150 , and a control section 170 . The digital PLL 300 according to the third embodiment of the present invention differs from the digital FLL 100 according to the first embodiment of the present invention illustrated in FIG. 1 , in including the phase comparator 310 instead of the frequency comparator 110 and in not including the frequency-digital convertor 160 .
In the digital PLL 300 , an oscillation frequency outputted from the VCO 150 is inputted as a loopback signal to the phase comparator 310 without any changes. The phase comparator 310 compares a channel signal D_ref to the loopback signal and outputs a phase error signal D_error between the channel signal D_ref and the loopback signal. In addition, a loopback path through which the oscillation frequency fout generated by the VCO 150 is looped back to the phase comparator 310 typically includes a DAC. The other process is the same as that of the digital FLL 100 according to the first embodiment of the present invention illustrated in FIG. 1 , and needless to say, the same effects are obtained.
Similarly as in the first embodiment, the digital PLL circuit 300 according to the third embodiment may be configured to further include at least either one of an averaging section 180 or an averaging section 190 as in a digital FLL 300 b illustrated in FIG. 9B . Further, the digital PLL 300 according to the third embodiment may be configured to further include a DAC 140 between the switch 210 and the VCO 150 as in a digital FLL 300 c illustrated in FIG. 9C .
Needless to say, the digital FLL 200 described in the second embodiment can similarly be applied as a digital PLL.
(Fourth Embodiment)
FIG. 10 is a diagram illustrating a polar modulation circuit 400 according to a fourth embodiment of the present invention. In FIG. 40 , the polar modulation circuit 400 includes a signal generation section 410 , a phase modulator 420 , a regulator 430 , and a power amplifier 440 .
In the polar modulation circuit 400 , the signal generation section 410 generates an amplitude signal and a phase signal. The amplitude signal is inputted to the regulator 430 . In addition, a direct-current voltage is supplied from a power supply terminal to the regulator 430 . The regulator 430 supplies a voltage Vcc controlled in accordance with the inputted amplitude signal, to the power amplifier 440 . Typically, the regulator 430 supplies a voltage Vcc proportional to the magnitude of the inputted amplitude signal, to the power amplifier 440 . The phase signal generated by the signal generation section 410 is inputted to the phase modulator 420 . The phase modulator 420 performs phase modulation on the phase signal and outputs a phase modulation signal. The power amplifier 440 amplifies the phase modulation signal with the voltage Vcc supplied from the regulator 430 . A signal Vout resulting from the amplification by the power amplifier 440 is outputted as a transmission signal from an output terminal.
The digital FLL/PLL of the present invention can be incorporated as a modulator used in the phase modulator 420 of the polar modulation circuit 400 .
(Fifth Embodiment)
FIG. 11 is a diagram illustrating a wireless communication device 500 according to a fifth embodiment of the present invention. In FIG. 11 , the wireless communication device 500 includes an antenna 510 , a power amplifier 520 , a modulator 530 , a switch 540 , a low noise amplifier 550 , a demodulator 506 , and a digital FLL/PLL 570 of the present invention.
When transmitting a wireless signal, the modulator 530 modulates a desired high frequency signal outputted from the digital FLL/PLL 570 , with a baseband modulation signal, and outputs the resultant signal. The high frequency modulation signal outputted from the modulator 530 is amplified by the power amplifier 520 , and radiated from the antenna 510 via the switch 540 .
When receiving a wireless signal, a high frequency modulation signal received by the antenna 510 is inputted into the low noise amplifier 550 via the switch 540 , amplified, and inputted into the demodulator 506 . The demodulator 506 demodulates the inputted high frequency modulation signal into a baseband modulation signal with the high frequency signal outputted from the digital FLL/PLL 570 . A plurality of the digital FLL/PLLs 570 may be used on the transmission side and the reception side. Furthermore, the digital FLL/PLL 570 may also serve as a modulator.
INDUSTRIAL APPLICABILITY
The present invention can be used in a wireless communication device or the like, and is useful particularly for the case where it is desired to converge the oscillation frequency of a VCO to a desired frequency at a high speed, or the like.
DESCRIPTION OF THE REFERENCE CHARACTERS
100 , 200 , 900 digital FLL
110 , 910 frequency comparator
120 , 920 FIR filter
130 , 930 IIR filter
140 , 940 DAC
150 , 950 VCO
160 , 960 frequency-digital convertor
170 control section
180 , 190 averaging section
121 to 123 , 135 , 921 to 923 , 935 delay block Z -1
124 , 125 , 132 , 134 , 924 , 925 , 932 , 934 adder
126 , 131 , 133 , 926 , 931 , 933 multiplier
210 , 540 switch
220 subband selection circuit
300 digital PLL
310 phase comparator
400 polar modulation circuit
410 signal generation section
420 phase modulator
430 regulator
440 , 520 power amplifier
500 wireless communication device
510 antenna
530 modulator
550 low noise amplifier
560 demodulator
570 digital FLL/PLL
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A digital FLL/PLL is provided which is capable of converging an oscillation frequency from a VCO to a desired frequency at a high speed even without setting a damping factor corresponding to each VCO gain. A digital FLL/PLL of the present invention includes: a comparator for comparing a channel signal to a loopback signal having an oscillation frequency to generate a signal error; a digital loop filter for generating a control voltage that determines the oscillation frequency, on the basis of the signal error; a VCO for controlling an oscillation frequency on the basis of the control voltage; a loopback path through which the oscillation frequency generated by the VCO is outputted as the loopback signal to the comparator; and a control section for monitoring the signal error, and controlling the digital loop filter such that the oscillation frequency of the VCO becomes a stationary state, when detecting that the signal error meets a predetermined condition after the channel signal is switched.
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FIELD OF THE INVENTION
The present invention relates to a holder for providing ambient light, and, more particularly, relates to a hand-held or portable baton for displaying and storing light sticks.
Among the common devices which provide light for an area or surface are candles, lamps, flashlights, streetlights, lanterns, and flares. Such lights have general purpose as well as recreational and safety uses. When flashlights, lanterns, and flares (which can be hand-held or mounted on sawhorses, stands, and barriers) are used in safety, hazard, and emergency situations, their purposes are varied, such as illuminating a dangerous area, like a collapsed structure, a washed out road or bridge, or a traffic accident scene. Flashlights, lanterns, and flares are also commonly used to assist in traffic and crowd control at public gatherings and events, such as fairs; air, boat, and car shows; and sporting competitions of all kinds.
One disadvantage of flares, in particular, is that they drip a noxious chemical substance during their use. When used by public safety and emergency personnel, such as police officers, firefighters, and EMT's, the flares are mounted on the road or road berm or held or waved by the public safety personnel for signaling to pedestrians and drivers that they are approaching a dangerous situation and should exercise caution in proceeding therethrough. However, if hand-held, the flares will drip and splatter the noxious substance on the uniform of the personnel, which will soil the uniforms and cause unsightly and/or unsafe holes to be produced thereon. New uniforms must then be purchased which are quite often an out-of-pocket expense for the personnel.
DESCRIPTION OF THE PRIOR ART
While flashlights, lamps, lanterns, and flares have been, and continue to be, used in various emergency and public safety situations, they have a number of shortcomings, especially when they must be held, carried, or manually waved by public safety personnel for extended periods of time. Waving lamps, lanterns, and policemen's flashlights over an extended period of time produces muscle strain and fatigue for the user. In addition, these devices produce only white light and, depending upon the circumstances, white light may not be the most penetrating or visible. Moreover, in many emergency and danger situations, a beam of white light may not be the most desirable form of light for warning approaching pedestrians or vehicles of the dangerous condition. An example of a light displaying device is the lighted baton of U.S. Pat. No. Des. 370,276.
SUMMARY OF THE INVENTION
The present invention comprehends a device for providing ambient light, and, more particularly, comprehends a hand-held or ground-mounted baton for displaying a first visible light source and storing therein a second light source.
The baton includes an elongated, generally tubular-shaped body having a first end and an opposite second end. The body also includes an inner bore which defines a storage chamber or compartment and is coequal in length with the body and extends from the first end to the second end. The first end of the body is closed by a removably securable cap or plug and mounted to the second end is a socket member. At least one illumination producer, generator or source in the form of a chemically-activated light stick is contained within the storage compartment, and a second light stick is mounted to the socket member so that a major portion of that light stick projects outwardly from the socket member for generating ambient illumination. A preferred light stick is described in U.S. Pat. No. 4,508,642, and is incorporated herein by reference. The light sticks shown in U.S. Pat. Nos. Des. 331,889, Des. 356,276, and Des. 368,045 can also be used with the baton of the present invention. In addition, U.S. Pat. Nos. 3,576,987 and 4,064,428 disclose light sticks composed of a range of compounds for producing chemiluminescent light, and both of these light sticks can be used with the baton of the present invention.
It is an objective of the present invention to provide a baton which is portable and easy to store and transport.
It is another objective of the present invention to provide a baton which includes an auxiliary or secondary illumination source as a replacement for the primary illumination source.
Still another objective of the present invention is to provide a baton which is lighter than a policeman's flashlight and safety flare and thereby produces less muscle fatigue and strain from the policeman's continuous waving of the baton during emergency or public safety situations.
Yet another objective of the present invention is to provide a baton which can be hand-held or carried pendent from the neck.
A further objective of the present invention is to provide a baton having an illumination source which produces various colors of light in addition to the standard white light of a flashlight.
A still further objective of the present invention is to provide a baton having as its illumination source at least one chemiluminescent light stick whereby attaching the light stick to the baton allows the light stick to throw more light than if the light stick is hand-held because a substantial portion of the light stick body projects outwardly from the baton.
Yet a further objective of the present invention is to provide a baton that includes structure to raise the light emitting end off the ground when the baton is set on the ground.
These and other features, objects, and advantages of the present invention will become apparent with reference to the follow description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the baton being held by an individual in the use disposition;
FIG. 2 is a perspective view of the baton with the body of the baton broken away;
FIG. 3 is an elevational view of the baton first shown in FIG. 1;
FIG. 4 is a perspective view of a light stick first shown in FIG. 1; and
FIG. 5 is a sectioned elevational view of the baton first shown in FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in FIGS. 1-5, the baton 10 includes an elongated, generally tubular-shaped body 12 which has a diameter which permits the user to easily grip and hold the baton 10 . The body 12 defines a generally cylindrical, exterior surface or sidewall 14 and is preferably constructed from a lightweight and durable plastic, such as polyvinylchloride (PVC), so that the body 12 is usable in all weather conditions. As shown in FIGS. 1-3, the body 12 is cylindrically-shaped, but, in the alternative, the body 12 could be square or rectangular-shaped. The body 12 includes a first end 16 , an opposite second end 18 , and an interior sidewall 20 which is coequal in length with the body 12 . The annular, interior sidewall 20 further defines an internal passageway or bore 22 which is coextensive with the sidewall 20 . Furthermore, the bore 22 defines an internal storage chamber, receptacle, or compartment, the purpose of which will be more fully described hereinafter. The first end 16 can be threaded to receive a closure means, such as a removably securable cap 24 . The attachment of the cap 24 to the first end 16 closes or seals the bore 22 at the first end 16 . A plug could also be used in place of the cap 24 . In addition, the cap 24 includes a lanyard 26 which allows the user to wear the baton 10 pendent from the user's neck so that the user's hands are free for other tasks.
Illustrated in FIGS. 1-3 and 5 is an illumination mounting means which can be integrally and permanently formed to the second end 18 of the body 12 or can be adapted for removable securement to the second end by being snapped or threaded thereon. The illumination mounting means of the present invention is a generally cylindrical-shaped socket member 28 which is mounted to the second end 18 of the body 12 so that the socket member 28 is in axial alignment with the bore 22 and the body 12 . The socket member 28 includes an interior, annular sidewall 30 which is circumjacent a socket passageway or bore 32 , and, when the socket member 28 is mounted to the second end 18 of the body 12 , both bores 22 and 32 are disposed in axial alignment with each other. The socket member 28 also includes an inner end 34 and an opposite outer end 36 . It is possible for the bore 32 of socket member 28 to terminate as a blind hole adjacent the inner end 34 .
As illustrated in FIGS. 1-3 and 5 , the socket member 28 also includes an anti-rotation means to restrict and limit the ability of the baton 10 to roll away from the user and under vehicles or off of the road surface should the baton 10 be accidentally dropped by the user. The anti-rotation means for the baton 10 includes a plurality of upraised flat surfaces or flats 38 integrally formed on the exterior cylindrical surface of the socket member 28 and which project radially and laterally therefrom adjacent the outer end 36 of the socket member 28 . The flats 38 are also circumjacent the bore 32 of the socket member 28 . The lateral and radial extension of the flats 38 from the exterior surface of the socket member can be increased from that shown in FIGS. 1-3 and 5 whereby the second end 18 of the baton 10 will be raised up from the ground a distance determined by the lateral extension of the flats 38 . The baton 10 adjacent the first end 16 will remain on the ground, and the distance the second end 18 is raised above the ground will depend, in part, on the magnitude of the lateral extension of the flats 38 from the socket member 28 . The structure of the flats 38 both provides an anti-rotation means for the baton 10 as well as enhancing the display of light when the baton 10 is set upon the ground.
As shown in FIGS. 2, 3 , and 5 , in order to support or hold the illumination producer or generator to or within the socket member 28 , the socket member 28 can include a plurality of internal threads 40 disposed circumjacent the bore 32 . In addition, as shown in FIG. 5, the socket member 28 can also include, in the alternative, a singular annular tooth or projection 42 projecting inwardly from the sidewall 30 . The projection 42 of FIG. 5 is helical in form but could be an annular horizontal projection instead. An alternative embodiment of the flats 38 could have them extend the length of the socket member 28 from the outer end 36 to the inner end 34 . Also, to enhance the visibility of the baton 10 , one or more bands or stripes 43 of fluorescent material can be painted or taped onto the body 12 of the tube 10 as shown in FIG. 1 .
As illustrated in FIGS. 1-5, the illumination producer, generator, or source is at least one, and, as used with the baton 10 of the present invention, two commercially available chemiluminescent light sticks 44 that can be purchased from safety products suppliers and distributors, retail hardware stores, and hunting, camping, and outdoor equipment suppliers. One version of a light stick is described in U.S. Pat. No. 4,508,642 and is incorporated in this specification by reference. Light sticks vary in the duration within which they produce light, and two common time durations are the one-half hour duration of high intensity ambient light production and the twelve hour time duration of ambient light production. The light produced is generally of the three primary colors: red, green, and blue. The baton 10 can contain and display light sticks 44 described in U.S. Pat. No. 4,508,642, as well as other light sticks currently available on the market. In order to initiate illumination, the user gently and slightly bends the light stick 44 , which action causes an internal chamber, tube, or casing to rupture, thereby causing the chemicals contained therein to admix with the chemicals contained within an outer casing or tube whereupon ambient light is produced and is viewable through the outer casing or tube. The light stick then returns to its normal longitudinal orientation. The light stick 44 includes a base end which generally has a diameter slightly larger than the diameter of the body of the light stick 44 . The light stick 44 also includes an opposite tapered or hook end which allows the light stick 44 to be tied to and dangled from a belt or pack when used by military personnel. Because the external casing or body of the light stick 44 is of a non-rigid, waxy, plastic composition, such as polyethylene, polypropylene, or TEFLON, the light sticks are never directly inserted or mounted into the ground, but are most commonly held or waved by, for example, a police officer or fireman.
When the baton 10 is used by a police officer, fireman, or an EMT in a public safety and emergency situation, the cap 24 is temporarily removed so that one light stick 44 can be fully inserted within the bore 22 of the body 12 whereupon the bore 22 serves as the storage chamber or receptacle for containing that respective light stick 44 . The cap 24 is then reattached to the first end 16 for closing off the storage chamber at the first end 16 in order to prevent that light stick 44 from falling out. The second light stick 44 is then mounted to the socket member 28 and, for the present invention, the base of the second light stick 44 can simply be rotated several turns against the threads 40 , whereupon the surface of the base is scored by the threads 40 —or by the singular annular projection 42 —and is thereby secured to the socket member 28 at the outer end 36 . The surface hardness of the threads 40 or annular projection 42 must be greater than the surface hardness of the exterior sidewall 14 of the body of the light stick 44 so that the threads 40 or annular projections 42 can be easily dig into and grip the base as the light stick 44 is being rotated into the bore 32 of the socket member 28 . It is also possible for the base end of the light stick 44 to be press-fitted into the bore 32 for attaching the light stick 44 to the socket member 28 . A substantial portion of that light stick 44 will protrude outwardly from the socket member 28 , and that light stick 44 will be in axial alignment with the bore 32 as well as the bore 22 of the baton 10 . The light stick 44 mounted to the socket member 28 may be referred to as the in-use light stick, and the light stick 44 contained and stored within the storage compartment or receptacle defined by bore 22 may be referred to as the replacement light stick. Because a substantial portion of the body of the in-use light stick 44 will project out from the socket member 28 , this light stick 44 will throw out much more light than a normally hand-held light stick 44 wherein perhaps one-half of the body of the hand-held light stick 44 , and, thus, much of its light, will be obscured by the user's hand. Should the user desire to lay the baton 10 on the ground while the in-use light stick 44 is projecting from the socket member 28 and radiating light, the laterally-projecting flats 38 serve to raise the baton 10 off the ground at an angle determined by the magnitude of the lateral projection of the flats 38 from the external sidewall of the socket member 28 . This allows the light emanating from the light stick 34 to have more visibility at a greater distance.
Therefore, when the illumination producing chemicals of the in-use light stick 44 are exhausted, that light stick 44 can be removed from the bore 32 of the socket member 28 for proper disposal. The user can then remove the cap 24 from the first end 16 of the body 12 and withdraw the replacement light stick 44 from the bore 22 so that the replacement light stick 44 can be mounted to the socket member 28 and thereupon slightly bent to initiate the chemical reaction which causes the replacement light stick to produce ambient light for the user. In addition, the body 12 could be lengthened so that the bore 22 could store two or more light sticks 44 in series, or the body 12 could be widened so that two or more light sticks 44 could be placed side-by-side for storage therein. For proper fitting therein, the light sticks 44 may need to be flip-flopped so that the tapered end of one light stick 44 would be next to the base of an adjacent light stick 44 .
A number of different types of bases or stands could be used with the baton 10 in order to avoid physically inserting the baton 10 into the ground. The first end 16 of the body 12 would be inserted within or secured to such a base or stand, thereby freeing the user to move about the area unencumbered by holding or waving the baton 10 .
Although the invention has been herein shown and described in what is believed to be the most practical preferred embodiment, it is recognized that departures may be made therefrom while still keeping within the scope of the invention.
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A hand-carriable baton for displaying at least one chemiluminescent light stick which provides a determinate period of ambient light includes an elongated tubular body having first and second ends, and an inner bore coequal in length with the body. The bore is closed at the first end by a removably securable cap to which a lanyard is attached, and secured to the second end is a socket member. One illumination producer in the form of a chemiluminescent light stick is mounted to the socket member for projecting outwardly therefrom for providing ambient light of fixed duration while a second illumination producer, also a chemiluminescent light stick, is stored within the bore for replacing the first light stick. The tubular body also includes an anti-rotation element adjacent the second end to prevent the device from rolling away from the user if dropped on any ground surface.
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FIELD OF THE INVENTION
[0001] The present inventions apply generally to improved methods of wastewater treatment in treatment facilities employing an activated sludge process. More particularly, the inventions are directed to enhancing the secondary treatment process by selected reaeration, recirculation and nitrification techniques that result in improved volumetric loading, hydraulic capacity and nutrient removal over conventional activated sludge treatment techniques.
BACKGROUND OF THE INVENTION
[0002] Wastewater generated by municipalities and industries water is commonly collected and routed to a treatment facility for the removal of a variety of physical, chemical and biological pollutants prior to being discharged into a receiving body of water. To effect the necessary treatment, many public and private treatment facilities employ both physical and biological treatment methods. Physical methods-including screening, grinding and physical setting processes-are effective for the removal of larger and heavier so ids in the wastewater. However, lighter, smaller solids and other soluble pollutants in the wastewater resist removal by physical methods. For these pollutants, biological treatment methods such as activated sludge and trickling filters are commonly employed.
[0003] In the activated sludge process, settled wastewater is introduced into a reactor where an aerobic microbial culture is maintained in suspension. The culture may include a variety of different strains of bacteria, protozoa and rotifers. The combination of this microbial culture and the wastewater is commonly referred to as mixed liquor. Aeration in the reactor creates an aerobic environment and maintains the mixed liquor in suspension. The microorganisms interact with the wastewater to create a biomass that is more amenable to physical settling. After a specified reaction period, mixed liquor is sent to a settling tank to separate and remove the accumulated solids. A portion of the settled solids is treated further and the remaining portion is returned to the reactor to maintain a specified microbial concentration in the mixed liquor.
[0004] A desirable microbial culture will decompose organic pollutants quickly and will form a floc to separate biosolids. Mean cell residence time (MCRT) is the average time the microbes are present to metabolize their food. For typical domestic wastewater, the mean cell residence time generally falls within the range of five to fifteen days. Within these limits the beneficial treatment qualities of the floc generally improve with increased residence time. There is a direct relationship between mean cell residence time and effluent waste concentration.
[0005] Effluent discharges from wastewater treatment works must meet certain water quality limitations for selected pollutant parameters which are specified in discharge permits issued in accordance with the National Pollution Discharge Elimination System (NPDES). In order to meet the permitted effluent limits, wastewater treatment facilities are designed for a specified peak hydraulic capacity and a peak volumetric pollutant loading. The specified peak capacity and loading fix the size of the treatment facility. Still, in areas of residential or industrial growth, increased water use leads to increased wastewater production that, in turn, leads to increased hydraulic loading. Industrial processes may also produce occasional “shock” loadings of pollutants that may overwhelm the pollutant removal capabilities of the existing biological treatment facilities.
[0006] With the conventional activated sludge process, the maximum recommended volumetric pollutant loading rate is 0.6 (kg BOD 5 applied/m 3 -day). Some enhancements to the conventional activated sludge process can increase volumetric pollutant loading without compromising the quality of the effluent. The known processes include enhanced aeration techniques, contact stabilization and Kraus process systems. However, even with known enhancements, there is an upper limit for volumetric loading. For enhancement by the Kraus process, the upper limit is 1.6 (kg BOD 5 , applied/m 3 -day) 1 . Modified aeration may raise the limit to 2.4 (kg BOD 5 , applied/m 3 -day). Pure oxygen aeration systems may attain a volumetric loading of up to 3.3 (kg BOD 5 applied/m 3 -day), but are rarely used due to high implementation and maintenance costs.
[0007] When pollutant loading or hydraulic capacity limits are reached, treatment facilities face the risk of permit limit violations, the possibility of Federal or State enforcement action, and restrictions or prohibitions on domestic and industrial growth within the service area of the treatment works. Typically, wastewater treatment facilities undergo physical expansion to meet the needs of increased hydraulic loading. But, physical expansion is expensive and often requires additional land that may not be available adjacent to existing facilities.
[0008] Therefore, it is desirable to find a way to increase volumetric pollutant loading and hydraulic capacity without the need for physical plant expansion. A significant advantage of the present invention over prior art methods of enhanced activated sludge processes is that volumetric pollutant loading can be substantially increased with only minor modifications to existing physical facilities. In addition, it is also a feature and advantage of the present invention that the enhanced activated sludge process produces a sludge with improved settling characteristics. Improved settling characteristics allow increases in hydraulic loading without requiring an increase in the size of the physical elements of the activated sludge system. By the same token, new activated sludge treatment works can be constructed in smaller sizes and at lower costs than known systems. With the enhanced activated sludge process of the present invention, design parameters that reflect the increased hydraulic capacity and pollutant loading capability can be incorporated into the sizing of the required structural elements to reduce the construction cost of new treatment works.
[0009] Most operators of wastewater treatment facilities have little or no control over the quality of the influent coming to the treatment plant they operate. Variations in domestic and industrial water use necessarily give rise to hourly, daily and seasonal fluctuations in influent wastewater quality. In particular, certain industrial events can result in the discharge of a “shock” pollutant load into the wastewater collection system and ultimately into the treatment plant. Such shock loading can upset the balance of the microbial culture present in the activated sludge reactor with a resulting loss of wastewater treatment effectiveness. Shock loading events also raise the risk of violating NPDES permit limitations on effluent quality with corresponding potential penalties and fines. It is another advantage of the present invention that the enhanced activated sludge process offers improved resistance to upsets of the microbial culture. It is also a feature and an advantage of the present invention that operating conditions of the activated sludge reactor are maintained in a more uniform condition, more resistant to undesirable variation in influent water quality changes.
[0010] For the activated sludge process to function properly, certain nutrients must be available in adequate amounts. The principal nutrients are nitrogen and phosphorus. While these nutrients are necessary for wastewater treatment, they may cause problems for aquatic life in the receiving waters where the treated effluent is discharged. Accordingly, the concentration of these nutrients in wastewater effluent is often limited by the NPDES discharge permit of the treatment facility. In these situations wastewater treatment facilities must include nutrient removal as part of the overall treatment process. In some cases the influent is nutrient deficient, requiring both the addition of nutrients and their subsequent removal. It is known in the art that nutrients may be added into the activated sludge process by chemical addition or, if digesters are present at the treatment works, by the recycling of digester supernatant.
[0011] Nutrient removal may be accomplished by any one of many suspended growth and attached growth processes that are known in the art. However, these systems often require the construction and operation of additional reactors and clarifiers, adding substantially to the cost of wastewater treatment. Therefore, it is a feature of the present invention that the enhanced activated sludge process can provide effective nutrient removal without the construction of separate nutrient removal reactors.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a process diagram of a common configuration for a conventional activated sludge treatment facility.
[0013] [0013]FIG. 2 is a process diagram for a conventional activated sludge treatment facility with a Kraus process modification.
[0014] [0014]FIG. 3 is a process diagram for an enhanced activated sludge process according to a preferred embodiment of the present invention.
[0015] [0015]FIG. 4 is a chart illustrating the relationship between influent and return activated sludge (RAS) versus time according to a preferred embodiment of the present invention.
[0016] [0016]FIG. 5 is a chart illustrating the relationship between mixed liquor suspended solids (MLSS) in the reaeration and general aeration zones versus time according to a preferred embodiment of the present invention.
[0017] [0017]FIG. 6 is a chart illustrating the relationship between respiration rate in the reaeration and general aeration zones versus time according to a preferred embodiment of the present invention.
[0018] [0018]FIG. 7 is a chart illustrating the relationship between dissolved oxygen concentrations in the Kraus and reaeration zones versus time according to a preferred embodiment of the invention.
[0019] [0019]FIG. 8 is an exemplary comparative table of plant performance factors for volumetric loading, hydraulic loading and nutrient removal during periods before and after implementation of the present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0020] Set forth below is a description of what is currently believed to be the preferred embodiments or best examples of the claimed inventions. Future and present alternatives and modifications to the preferred embodiments are contemplated. Any alternatives or modifications which make insubstantial changes in function, in purpose, in structure or in result are intended to be covered by the claims of this patent.
[0021] Physical Characteristics
[0022] While it is within the understanding of the invention that the claimed treatment processes can be incorporated into the design and construction of new treatment facilities, the best mode of practicing the invention involves the retrofitting of existing treatment works. FIG. 1 depicts a process diagram of a conventional activated sludge treatment system. Commonly, the activated sludge treatment step will be preceded by a physical settling process and may be followed by supplemental treatment prior to discharge at the treatment plant outfall. Therefore the influent 10 refers to the influent stream entering the aeration reactor 12 and the effluent 11 refers to the effluent stream leaving the settling tanks 13 . The aeration reactor 12 may be a single basin or may be partitioned into multiple zones to facilitate operation and maintenance. The settling basin 13 may also consist of one or more operating units. Process piping 14 , 15 , 16 conveys the solids collected from the settling basin to one or more locations. For example, a process line 14 may return activated sludge to the upstream side of the aeration basin 12 . Other process lines 15 , 16 may route activated sludge to digesters 17 or to a waste process for thickening or disposal. The process lines 14 , 15 , 16 may include a combination of valves, pumps and automated controls as are known in the art to provide the treatment plant operator with the ability to control the volume of sludge drawn from the settling basin 13 and the portion of the withdrawn sludge that is directed through each process line.
[0023] [0023]FIG. 2 is a schematic illustrating an activated sludge treatment system that has been modified according to the Kraus process. The Kraus process involves adding one or more process lines 18 to return digester supernatant and, optionally, digested sludge from the digester 17 to the aeration basin 12 . The return flow from the digester passes through a reaeration basin 19 prior to being reintroduced to the reactor 12 for the general aeration of the activated sludge.
[0024] In order to employ the enhanced activated sludge treatment process of the present invention in an existing conventional activated sludge system, the general aeration reactor 12 should preferably be partitioned into subsets of the total reactor volume. The size and number of partitioned subsets may be dictated by operational convenience or other factors as it is not significant to the result obtained by the present invention. Alternatively, additional basins may be constructed adjacent to the existing aeration basin and hydraulicly connected with associated piping and channels. In this alternative, the collection of separately constructed basins comprise the aeration reactor 12 that is to be partitioned.
[0025] [0025]FIG. 3 shows the general aeration basin 12 of a conventional activated sludge treatment process that has been partitioned into sixteen discreet aeration zones 20 a - 20 p of generally equal volume. Aeration equipment, as is known in the art, is present in the aeration zones 20 a - 20 p to transfer oxygen to the mixed liquor. In the preferred embodiment, six of the sixteen aeration zones (37.5% by volume) are removed from the initial general aeration process and reserved for the receipt of return activated sludge (RAS). These six zones are the reaeration zones 22 a - 22 f of the present invention. RAS enters the reaeration zones 22 a - 22 f at the upstream end and exits at the downstream end into the general aeration zones 24 . Of the six reaeration zones 22 a - 22 f two (33% by volume) are reserved as Kraus zones 26 for operation according to the Kraus process. In the Kraus zones 26 digester supernatant is combined with the return activated sludge. The contents are reaerated prior to being returned to the general aeration zones 24 .
[0026] The preferred embodiment also includes a biological selector 30 upstream of the general aeration zones 24 that is normally operated in an anoxic state. When operated in this manner, the dissolved oxygen concentration is typically between 0.0 mg/l and 0.2 mg/l. The biological selector 30 can be operated in oxic, anoxic and anaerobic conditions as desired to stress the biological culture in the selector and promote a desirable sludge type in the aeration phase.
[0027] The control of return activated sludge rates, waste activated sludge rates and supernatant addition is regulated in the preferred embodiment by process automation. Readings from respirometers 25 , solids meters 31 , and on-line RedOx monitors 32 are calibrated against laboratory analyses. Once calibrated, the readings are combined with the results of settleable solids testing to dictate process variable set points (such as flow rates and dissolved oxygen) to achieve overall process control.
[0028] Operating Conditions
[0029] The enhanced activated sludge treatment method of the preferred embodiment involves controlling selected conditions in the aeration phase of the treatment process. First, the return flow rate of activated sludge from the settling basin 13 to the upstream side of the aeration phase is preferably maintained at approximately 30% of the influent 10 to the aeration phase as illustrated in FIG. 4. While the preferred return rate is 30%, the process remains effective for return rates in the range of 25% to 60% of the influent flow rate. The return rate has an inverse correlation to the total suspended solids (TSS) concentration of the RAS. At low sludge return rates, as employed in the preferred embodiment, the solids concentration of the RAS may be as high as 20,000 ppm.
[0030] The sludge volume index (SVI) of the mixed liquor in the general aeration phase, as measured from a sample drawn preferably at a point between the aeration phase and the settling phase is an indication of the settling characteristics of the sludge. Generally, the SVI for the present invention can be expected to fall within the range of 40-80. For the preferred embodiment, the expected range is 40-60. Activated sludge return rates on the higher end of the beneficial range are appropriate where the SVI is similarly high.
[0031] Limiting the volume of the return activated sludge as described above results in a heavier solids concentration in the return line 14 than in the influent line 10 . The additional solids are then retained in the reaeration zones 22 a - 22 f of the aeration phase so that the concentration of mixed liquor suspended solids (MLSS) in the reaeration zones 22 a - 22 f is typically 8,000-12,000 ppm as compared to the concentration of MLSS in the general aeration zones 24 which is typically 3,000-5,000 ppm. In cold weather conditions, the MLSS in the general aeration zones 24 is slightly higher with typical concentrations of 5,000-6,000 ppm. The relationship of solids concentrations in the general aeration zones 24 , reaeration zones 22 a - 22 f and return sludge are illustrated in FIG. 5.
[0032] The respiration rate of the biological culture varies between the selector 30 , reaeration zones 22 a - 22 f and the general aeration zones 24 as illustrated in FIG. 6. When operating according to the preferred embodiment, the respiration rate in the reaeration zones 22 is consistently lower than the respiration rate of the general aeration zones 24 . The respiration rate, also known as the specific oxygen uptake rate (SOUR) is used an indicator of sludge age. A high SOUR measured in the selector 30 indicates that the sludge age is too low and sludge wasting should be reduced. A low SOUR measured in the general aeration zones 24 indicates that the sludge age is too high and sludge wasting should be increased.
[0033] Process controls on the means of aeration, as are known in the art, allow the operator to selectively adjust the concentration of dissolved oxygen (DO) in the reaeration zones 22 . In the preferred embodiment, the DO concentration in the mixed liquor at the downstream end of the Kraus zones 26 is typically 1.5 mg/l-3.0 mg/l. If ammonia nitrogen is present in the effluent 12 of the aeration phase, the DO concentration in the Kraus zones 26 is increased. The non-Kraus reaeration zones 22 c - 22 f are operated with the least amount of aeration that is necessary to maintain the solids of the mixed liquor in suspension. Typically, the DO concentration at the downstream end of the reaeration zones 22 c - 22 f is 0.1 mg/l-0.3 mg/l.
[0034] The differential aeration between the Kraus zones 26 and the other reaeration zones 22 c - 22 f has the effect of enhancing nitrogen removal. Where conventional, single stage nitrification has a 70% nitrogen removal efficiency, the differential aeration of the preferred embodiment increases the nitrogen removal efficiency to 95%. The desired differential aeration can be expressed as a ratio between the DO concentrations, the downstream ends of the Kraus zones 26 and the other reaeration zones 22 c - 22 f. In the preferred embodiment, that ratio is typically greater than 5:1. Ratios as low as 2:1 are also known to achieve improved nitrogen removal efficiency.
[0035] The combination of aeration partitioning, return activated sludge rate control, and differential MLSS concentrations described above create an improved solids type with low and stable SVI. The high MLSS in the reaeration zones 22 provides buffering capacity for shock pollutant loadings that resists typical process upsets and increases the volumetric loading capacity to values as much as six times the maximum loading capacity reported for conventional activated sludge systems with Kraus process modifications. The low and stable SVI produces gains in hydraulic capacity of 50% in the preferred embodiment. The further operation of differential DO concentrations in the reaeration zones 22 c - 22 f and the Kraus zones 26 enhances nutrient removal efficiency. Resulting nutrient removal rates achieved by the enhanced process of the preferred embodiment are typically 0.005 lbs. N/lb. VSS as an annual average and 0.010 lbs. N/lb. VSS during warm weather seasons. The performance factors expected for typical municipal wastewater treatment plants before and after practicing the described method are reported in FIG. 8.
[0036] The above description is not intended to limit the meaning of the words used in the following claims that define the invention. Rather, it is contemplated that future modifications in structure, function or result will exist that are not substantial changes and that all such unsubstantial changes in what is claimed are intended to be covered by the claims.
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An enhanced activated sludge wastewater treatment method increases volumetric pollutant loading, hydraulic loading capacity and nutrient removal efficiency at a conventional activated sludge wastewater treatment plant. The method describes the control of return activated sludge rates, and the operation of partitioned aeration and reaeration zones according to measured properties of the mixed liquor to achieve the claimed benefits. Operating an existing treatment plant according to the enhanced treatment method provides a more consistent treatment process that is resistant to shock loading and increases plant capacity without the need for costly construction and operation of additional reactors and clarifiers.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application is a division of copending application Ser. No. 11/555,833, filed Nov. 2, 2006 (Publication No. 2007/0057908), which is a continuation of application Ser. No. 10/652,218, filed Aug. 29, 2003 (now U.S. Pat. No. 7,148,128, issued Dec. 12, 2006), which is a continuation of U.S. Ser. No. 10/200,571, filed Jul. 22, 2002 (now U.S. Pat. No. 6,652,075, issued Nov. 25, 2003), which is a continuation of U.S. Ser. No. 09/471,604, filed Dec. 23, 1999 (now U.S. Pat. No. 6,422,687 issued Jul. 23, 2002), which is a divisional of U.S. Ser. No. 08/935,800, filed Sep. 23, 1997 (now U.S. Pat. No. 6,120,588 issued Sep. 19, 2000), which claims priority to U.S. Provisional Application No. 60/035,622, filed Sep. 24, 1996, and claims priority to and is a continuation-in-part of International Application PCT/US96/13469, filed Aug. 20, 1996, which claims priority to U.S. Provisional Application No. 60/022,222, filed Jul. 19, 1996, the entire disclosures of which applications are incorporated herein by reference in their entirety.
BACKGROUND OF INVENTION
[0002] Currently, printing of conductors and resistors is well known in the art of circuit board manufacture. In order to incorporate logic elements the standard practice is to surface mount semiconductor chips onto said circuit board. To date there does not exist a system for directly printing said logic elements onto an arbitrary substrate.
[0003] In the area of flat panel display drivers there exists technology for laying down logic elements onto glass by means of vacuum depositing silicon or other semiconductive material and subsequently etching circuits and logic elements. Such a technology is not amenable to laying down logic elements onto an arbitrary surface due to the presence of the vacuum requirement and the etch step.
[0004] In the area of electronically addressable contrast media (as may be used to effect a flat panel display) emissive and reflective electronically active films (such as electroluminescent and electrochromic films), polymer dispersed liquid crystal films, and bichromal microsphere elastomeric slabs are known. No such directly electronically addressable contrast medium however is amenable to printing onto an arbitrary surface.
[0005] Finally in the area of surface actuators electrostatic motors, which may be etched or non-etched, are known in the art. In the first case, such etched devices suffer from their inability to be fabricated on arbitrary surfaces. In the second case, non-etched devices suffer from the inability to incorporate drive logic and electronic control directly onto the actuating surface.
[0006] It is an object of the present disclosure to overcome the limitations of the prior art in the area of printable logic, display and actuation.
SUMMARY OF THE INVENTION
[0007] In general the present invention provides a system of electronically active inks and means for printing said inks in an arbitrary pattern onto a large class of substrates without the requirements of standard vacuum processing or etching. Said inks may incorporate mechanical, electrical or other properties and may provide but are not limited to the following function: conducting, insulating, resistive, magnetic, semiconductive, light modulating, piezoelectric, spin, optoelectronic, thermoelectric or radio frequency.
[0008] In one embodiment this invention provides for a microencapsulated electric field actuated contrast ink system suitable for addressing by means of top and bottom electrodes or solely bottom electrodes and which operates by means of a bichromal dipolar microsphere, electrophoretic, dye system, liquid crystal, electroluminescent dye system or dielectrophoretic effect. Such an ink system may be useful in fabricating an electronically addressable display on any of a large class of substrate materials which may be thin, flexible and may result in an inexpensive display.
[0009] In another embodiment this invention provides for a semiconductive ink system in which a semiconductor material is deployed in a binder such that when said binder is cured a percolated structure with semiconductive properties results.
[0010] In another embodiment this invention for provides for systems capable of printing an arbitrary pattern of metal or semiconductive materials by means of photoreduction of a salt, electron beam reduction of a salt, jet electroplating, dual jet electroless plating or inert gas or local vacuum thermal, sputtering or electron beam deposition.
[0011] In another embodiment this invention provides for semiconductor logic elements and electro-optical elements which may include diode, transistor, light emitting, light sensing or solar cell elements which are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Additionally said elements may be multilayered and may form multilayer logic including vias and three dimensional interconnects.
[0012] In another embodiment this invention provides for analog circuits elements which may include resistors, capacitors, inductors or elements which may be used in radio applications or magnetic or electric field transmission of power or data.
[0013] In another embodiment this invention provides for an electronically addressable display in which some or all of address lines, electronically addressable contrast media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Such display may further comprise a radio receiver or transceiver and power means thus forming a display sheet capable of receiving wireless data and displaying the same.
[0014] In another embodiment this invention provides for an electrostatic actuator or motor which may be in the form of a clock or watch in which some or all of address lines, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments.
[0015] In another embodiment this invention provides for a wrist watch band which includes an electronically addressable display in which some or all of address lines, electronically addressable contrast media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments. Said watch band may be formed such that it has no external connections but rather receives data and or power by means of electric or magnetic field flux coupling by means of an antennae which may be a printed antennae.
[0016] In another embodiment this invention provides for a spin computer in which some or all of address lines, electronically addressable spin media, logic or power are fabricated by means of a printing process or which employ an electronically active ink system as described in the aforementioned embodiments.
[0017] Further features and aspects will become apparent from the following description and from the claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention.
[0019] FIGS. 1A-F are schematic representations of means of fabricating particles with a permanent dipole moment.
[0020] FIGS. 2A-C are schematic representations of means of microencapsulation.
[0021] FIGS. 3A-E are schematic representations of microencapsulated electronically addressable contrast media systems suitable for top to bottom addressing.
[0022] FIGS. 4A-M are schematic representations of microencapsulated electronically addressable contrast media systems suitable for bottom addressing.
[0023] FIGS. 5A-D are schematic representations of microencapsulated electronically addressable contrast media systems based on a dielectrophoretic effect.
[0024] FIGS. 6A-B are schematic representations of microencapsulated electronically addressable contrast media systems based on a frequency dependent dielectrophoretic effect.
[0025] FIGS. 6C-E are plots of the dielectric parameter as a function of frequency for various physical systems.
[0026] FIGS. 7A-D are schematic representations of electronic ink systems and means for printing the same.
[0027] FIG. 8 is a schematic representation of a laser reduced metal salt ink system.
[0028] FIGS. 9A-E are schematic representations of electronic ink systems and means for printing the same.
[0029] FIGS. 10A-C are schematic diagrams of printed transistor structures.
[0030] FIG. 10D is a schematic diagram of a printed optoelectronic element.
[0031] FIGS. 10E-H are schematic diagrams of printed analog circuit elements.
[0032] FIGS. 11A-C are a schematic diagram of an electronic display employing printed elements which; this display may further include a data receiver or transceiver and a power means.
[0033] FIG. 12 is a schematic diagram of an electrostatic motor which may be in the form of a watch or clock in which said electrostatic elements are printed.
[0034] FIGS. 13A-B are a schematic diagram of a watch in which the wristband of said watch incorporates an electronically addressable display having printed elements and which may further comprise wireless means for sending or receiving data or power between watch and watchband.
[0035] FIG. 14 is a schematic diagram of a spin computer.
DETAILED DESCRIPTION
[0036] Means are known in the prior art for producing bichromal particles or microspheres for use in electronic displays. Such techniques produce a particle that does not have an implanted dipole moment but rather relies in general on the Zeta potential of the material to create a permanent dipole. Such a scheme suffers from the fact that it links the material properties to the electronic properties thus limiting the size of the dipole moment which may be created. FIG. 1 details means of producing particles, either bichromal as might be used in an electrostatic display, or monochromal as might be used in a dielectrophoretic display, with an implanted dipole moment.
[0037] Referring to FIG. 1A , atomizing nozzles 1 are loaded with materials 12 and 13 which may be differently colored. A first atomizing nozzle may be held at a positive potential 3 and a second nozzle may be held at a negative potential 4 . Such potentials aid in atomization and impart a charge to droplets which form from said nozzles producing positively charged droplets 5 and negatively charged droplets 6 . Such opposite charged droplets are attracted to each other electrostatically forming an overall neutral pair. After the formation of a neutral pair there is no more electrostatic attraction and no additional droplets are attracted to the neutral pair. If said material 12 and 13 is such that the particles are liquid when exiting said nozzles and either cool to form a solid or undergo a chemical reaction which may involve an additional hardening agent to form a solid then said charge may be trapped on each side of said neutral pair forming a bichromal solid particle with an implanted dipole 16 . By suitable choice of materials such as polyethylene, polyvinylidene fluoride or other materials such metastable dipoles may persist for long periods of time as is known in the art of electrets. A heating element 7 may serve to reheat said pair thus minimizing surface tension energy and serving to reform said pair into a more perfect spherical shape. Finally a set of electrodes 8 biased at either the same or opposite voltage may be employed to trap particles which are not overall charge neutral.
[0038] Referring to FIG. 1B a similar apparatus may be employed to create a monochromal particle with an implanted dipole. In this arrangement nozzles containing material of the same color 12 are employed as before to create a monochromal particle with implanted dipole 21 .
[0039] Referring to FIGS. 1C and 1D alternative means are shown for producing a bichromal particle with implanted dipole by means of combining two differentially colored materials 12 and 13 on a spinning disk 11 or in a double barreled nozzle 19 . Said materials are charged by means of positive electrode 14 and negative electrode 15 and combine by means of electrostatic attraction at the rim of said disk or exit of said double barrel nozzle to form bichromal particle with implanted dipole moment 16 . Said means differs from that known in the art by means of causing said two different materials 12 and 13 to coalesce by means of electrostatic attraction as opposed to relying on surface properties and interactions between the two materials. Additionally the present scheme creates a particle with an implanted dipole moment 16 which may serve to create a larger dipole moment than that possible from the naturally occurring Zeta potential.
[0040] Referring to FIGS. 1E and 1F , a similar apparatus may be employed to create a monochromal particle with an implanted dipole. In this arrangement nozzles containing material of the same color 12 are employed as before to create a monochromal particle with implanted dipole 21 .
[0041] A large number of techniques are known in the literature for microencapsulating one material inside of another material. Such techniques are generally used in the paper or pharmaceutical industry and do not generally produce a microcapsule which embodies simultaneously the properties of optical clarity, high dielectric strength, impermeability and resistance to pressure. With proper modification however these techniques may be made amenable to microencapsulating systems with electronic properties.
[0042] Referring to FIG. 2A , an internal phase 25 may be a liquid or may be a solid with an additional associated surface layer 27 . Said internal phase if liquid or said associated surface layer may contain a polymer building block, such as adipoyl chloride in silicone oil. Said internal phase, with associated boundary layer in the case of a liquid, may then be dispersed in a continuous phase liquid 30 which may be an aqueous solution which is immiscible with said internal phase or associated surface layer. Finally a solution 40 which contains another polymer building block or cross linking agent may be added to continuous phase liquid 30 . Said solution 40 has the effect of forming a solid layer at the interface of the internal phase or associated surface layer and said continuous phase liquid 30 thus acting to microencapsulate said internal phase.
[0043] Referring to FIG. 2B an internal phase 25 which may be a solid or a liquid may be caused to pass through a series of liquid films 50 , 60 , 70 which may contain polymer building blocks, cross linking agents and overcoat materials such that a final microcapsule 120 results comprised of an internal phase 25 , an associated surface layer 27 and an outer shell 80 .
[0044] An alternate means of microencapsulation is shown in FIG. 2C . In this scheme a light source 82 which may be a UV light source passes in some areas through a photomask 84 exposing a crosslinkable polymer which may be caused to form a cellular structure 86 . The individual cells of said cellular structure may then be filled with an internal phase 25 .
[0045] Employing the systems described in FIGS. 2A-C it is possible to microencapsulate systems with electronically active properties specifically electronically addressable contrast media. FIG. 3 details such electronically addressable contrast media systems which are suitable for addressing by means of a top clear electrode 100 and bottom electrode 110 . Referring to FIG. 3A a microcapsule 120 may contain a microsphere with a positively charged hemisphere 142 and a negatively charged 140 hemisphere and an associated surface layer material 130 . If said hemispheres are differentially colored an electric field applied to said electrodes may act to change the orientation of said sphere thus causing a perceived change in color.
[0046] Referring to FIG. 3B a microcapsule 120 may contain positively charged particles of one color 210 and negatively charged particles of another color 220 such that application of an electric field to said electrodes causes a migration of the one color or the other color, depending on the polarity of the field, toward the surface of said microcapsule and thus effecting a perceived color change. Such a system constitutes a microencapsulated electrophoretic system.
[0047] Referring to FIGS. 3C-D , a microcapsule 120 may contain a dye, dye precursor or dye indicator material of a given charge polarity 230 or a dye, dye precursor or dye indicator material attached to a particle of given charge polarity such as a microsphere with an appropriate surface group attached and a reducing, oxidizing, proton donating, proton absorbing or solvent agent of the other charge polarity 240 or a reducing, oxidizing, proton donating, proton absorbing or solvent agent attached to a particle of the other charge polarity. Under application of an electric field said dye substance 230 is maintained distal to said reducing, oxidizing, proton donating, proton absorbing or solvent agent 240 thus effecting one color state as in FIG. 3C . Upon de-application of said electric field said dye substance and said reducing, oxidizing, proton donating, proton absorbing or solvent agent may bond to form a complex 245 of second color state. Suitable materials for use in this system are leuco and lactone dye systems and other ring structures which may go from a state of one color to a state of a second color upon application of a reducing, oxidizing or solvent agent or dye indicator systems which may go from a state of one color to a state of a second color upon application of a proton donating or proton absorbing agent as is known in the art. An additional gel or polymer material may be added to the contents of said microcapsule in order to effect a bistability of the system such that said constituents are relatively immobile except on application of an electric field.
[0048] Referring to FIG. 3E , a microcapsule 120 may contain phosphor particles 255 and photoconductive semiconductor particles and dye indicator particles 260 in a suitable binder 250 . Applying an AC electric field to electrodes 100 and 110 causes AC electroluminescence which causes free charge to be generated in the semiconducting material further causing said dye indicator to change color state.
[0049] Referring to FIGS. 4A-M , it may be desirable to develop ink systems which are suitable for use without a top transparent electrode 100 which may degrade the optical characteristics of the device. Referring to FIGS. 4A and 4B , the chemistry as described in reference to FIGS. 3C-D may be employed with in-plane electrodes such that said chemistry undergoes a color switch from one color state to a second color state upon application of an electric field to in-plane electrodes 270 and 280 . Such a system is viewed from above and thus said electrodes may be opaque and do not effect the optical characteristics of said display.
[0050] As another system in-plane switching techniques have been employed in transmissive LCD displays for another purpose, namely to increase viewing angle of such displays. Referring to FIGS. 4C and 4D a bistable liquid crystal system of the type demonstrated by Hatano et. al. of Minolta Corp. is modified to be effected by in plane electrodes such that a liquid crystal mixture transforms from a first transparent planar structure 290 to a second scattering focal conic structure 292 .
[0051] Referring to FIG. 4E the system of FIG. 3E may be switched by use of in-plane electrodes 270 and 280 .
[0052] Other systems may be created which cause a first color change by means of applying an AC field and a second color change by means of application of either a DC field or an AC field of another frequency. Referring to FIGS. 4F-G , a hairpin shaped molecule or spring in the closed state 284 may have attached to it a positively charged 282 and a negatively charged 283 head which may be microspheres with implanted dipoles. Additionally one side of said hairpin shaped molecule or spring has attached to it a leuco dye 286 and the other side of said hairpin shaped molecule or spring has attached to it a reducing agent 285 . When said molecule or spring is in the closed state 284 then said leuco dye 286 and said reducing agent 285 are brought into proximity such that a bond is formed 287 and said leuco dye is effectively reduced thus effecting a first color state. Upon a applying an AC electric field with frequency that is resonant with the vibrational mode of said charged heads cantilevered on said hairpin shaped molecule or spring said bond 287 may be made to break, thus yielding an open state 288 . In said open state the leuco dye and reducing agent are no longer proximal and the leuco dye, being in a non-reduced state, effects a second color state. The system may be reversed by applying a DC electric field which serves to reproximate the leuco dye and reducing agent groups. Many molecules or microfabricated structures may serve as the normally open hairpin shaped molecule or spring. These may include oleic acid like molecules 289 . Reducing agents may include sodium dithionite. The system as discussed is bistable. Energy may be stored in said hairpin shaped molecule or spring and as such said system may also function as a battery.
[0053] Referring to FIGS. 4I-K an alternative leucodye-reducing agent system may employ a polymer shown in FIG. 41 in a natural state 293 . When a DC electric field is applied said polymer assumes a linear shape 294 with leuco 286 and reducing agent 285 groups distal from each other. Upon application of either a reversing DC field or an AC electric field said polymer will tend to coil bringing into random contact said leuco and reducing groups forming a bond 287 with a corresponding color change. Said polymer serves to make said system bistable.
[0054] Referring to FIGS. 4L and 4M , a similar system is possible but instead polymer leuco and reducing groups may be attached to oppositely charge microspheres directly by means of a bridge 286 which may be a biotin-streptavidin bridge, polymer bridge or any other suitable bridge. As before application of a DC field cause leuco and reducing groups to become distal whereas application of a reverse DC field or AC field brings into random contact the leuco and reducing groups. A polymer may be added to aid in the stability of the oxidized state.
[0055] Referring to FIGS. 5A-D and FIGS. 6A-B an entirely different principle may be employed in an electronically addressable contrast media ink. In these systems the dielectrophoretic effect is employed in which a species of higher dielectric constant may be caused to move to a region of high electric field strength.
[0056] Referring to FIGS. 5A and 5B a non-colored dye solvent complex 315 which is stable when no field is applied across electrode pair 150 may be caused to become dissociate into colored dye 300 and solvent 310 components by means of an electric field 170 acting differentially on the dielectric constant of said dye complex and said solvent complex as applied by electrode pair 150 . It is understood that the chemistries as discussed in the system of FIG. 3C-D may readily be employed here and that said dye complex and said solvent complex need not themselves have substantially different dielectric constants but rather may be associated with other molecules or particles such as microspheres with substantially different dielectric constants. Finally it is understood that a gel or polymer complex may be added to the contents of said microcapsule in order to effect a bistability.
[0057] Referring to FIG. 5C-D stacked electrode pairs 150 and 160 may be employed to effect a high electric field region in a higher 170 or lower 180 plane thus causing a higher dielectric constant material such as one hemisphere of a bichromal microsphere 141 or one species of a mixture of colored species 147 to migrate to a higher or lower plane respectively and give the effect of differing color states. In such schemes materials 165 which may be dielectric materials or may be conducting materials may be employed to shape said electric fields.
[0058] Referring to FIGS. 6A-B , systems based on a frequency dependent dielectrophoretic effect are described. Such systems are addressed by means of applying a field of one frequency to produce a given color and applying a field of a different frequency to produce another color. Such a functionality allows for a rear addressed display.
[0059] Referring to FIG. 6A , a microcapsule 120 encompasses an internal phase 184 which may be a material which has a frequency independent dielectric constant as shown in FIG. 6C , curve 320 and which may have a first color B and material 182 which has a frequency dependent dielectric constant and a second color W. Said frequency dependent material may further have a high dielectric constant at low frequency and a smaller dielectric constant at higher frequency as shown in FIG. 6C , curve 322 . Application of a low frequency AC field by means of electrodes 270 and 280 causes said material 182 to be attracted to the high field region proximal the electrodes thus causing said microcapsule to appear as the color B when viewed from above. Conversely application of a high frequency AC field by means of electrodes 270 and 280 causes said material 184 to be attracted to the high field region proximal the electrodes thus displacing material 182 and thus causing said microcapsule to appear as the color W when viewed from above. If B and W correspond to Black and White then a black and white display may be effected. A polymer material may be added to internal phase 184 to cause said system to be bistable in the field off condition. Alternatively stiction to the internal side wall of said capsule may cause bistability.
[0060] Referring to FIG. 6A , material 182 and FIG. 6C , a particle is fabricated with an engineered frequency dependent dielectric constant. The means for fabricating this particle are depicted in FIGS. 1B , E and F. At low frequency such dipolar particles have sufficiently small mass that they may rotate in phase with said AC field thus effectively canceling said field and acting as a high. dielectric constant material. At high frequency however the inertia of said particles is such that they cannot keep in phase with said AC field and thus fail to cancel said field and consequently have an effectively small dielectric constant.
[0061] Alternatively material 182 may be comprised of naturally occurring frequency dependent dielectric materials. Materials which obey a frequency dependence functionality similar to the artificially created dipole material discussed above and which follow curves similar to FIG. 6C , curve 322 include materials such as Hevea rubber compound which has a dielectric constant of K=36 at f=10 3 Hz and K=9 at f=10 6 Hz, materials with ohmic loss as are known in Electromechanics of Particles by T. B. Jones incorporated herein by reference and macromolecules with permanent dipole moments.
[0062] Additionally material 182 may be a natural or artificial cell material which has a dielectric constant frequency dependence as depicted in FIG. 6D , curve 330 as are discussed in Electromechanics of Particles by T. B. Jones incorporated herein by reference. Such particles are further suitable for fabrication of an electronically addressable contrast ink.
[0063] Referring to FIG. 6B , a system is depicted capable of effecting a color display. Microcapsule 120 contains a particle of a first dielectric constant, conductivity and color 186 , a particle of a second dielectric constant, conductivity and color and an internal phase of a third dielectric constant, conductivity and color 190 . Referring to FIG. 6E it is known in the art of electromechanics of particles that for particles with ohmic loss (e.g. finite conductivity) at low frequency the DC conductivity governs the dielectric constant whereas at high frequency the dielectric polarization governs the dielectric constant. Thus a particle with finite conductivity has a dielectric constant K as a function of frequency f as in FIG. 6E , curve 338 . A second particle of second color has a dielectric constant K as a function of frequency f as in FIG. 6E , curve 340 . Finally an internal phase with no conductivity has a frequency independent dielectric constant K, curve 336 . If an AC field of frequency f 1 is applied by means of electrodes 270 and 280 , material 186 of color M will be attracted to the high field region proximal to said electrodes thus causing said microcapsule to appear as a mixture of the colors C and Y, due to the other particle and internal phase respectively, when viewed from above. If an AC field of frequency f 2 is applied by means of electrodes 270 and 280 material 188 of color Y will be attracted to the high field region proximal to said electrodes thus causing said microcapsule to appear as a mixture of the colors C and M when viewed from above. Finally if an AC field of frequency f 3 is applied by means of electrodes 270 and 280 internal phase 190 of color C will be attracted to the high field region proximal to said electrodes thus causing said microcapsule to appear as a mixture of the colors M and Y when viewed from above. If C, M and Y correspond to Cyan, Magenta and Yellow a color display may be effected.
[0064] It is understood that many other combinations of particles with frequency dependent dielectric constants arising from the physical processes discussed above may be employed to effect a frequency dependent electronically addressable display.
[0065] In addition to the microencapsulated electronically addressable contrast media ink discussed in FIGS. 3-6 , FIGS. 7-9 depict other types of electronically active ink systems. In the prior art means are known for depositing metals or resistive materials in a binding medium which may later be cured to form conducting or resistive traces. In the following description novel means are described for depositing semiconductive materials in a binder on a large class of substrate materials in one case and for depositing metals, resistive materials or semiconductive materials outside of vacuum, in an arbitrary pattern, without the need for an etch step and on a large class of substrate materials in another case.
[0066] In one system a semiconductor ink 350 may be fabricated by dispersing a semiconductor powder 355 in a suitable binder 356 . Said semiconductor powder may be Si, Germanium or GaAs or other suitable semiconductor and may further be with n-type impurities such as phosphorus, antimony or arsenic or p-type impurities such as boron, gallium, indium or aluminum or other suitable n or p type dopants as is known in the art of semiconductor fabrication. Said binder 356 may be a vinyl, plastic heat curable or UV curable material or other suitable binder as is known in the art of conducting inks Said semiconductive ink 350 may be applied by printing techniques to form switch or logic structures. Said printing techniques may include a fluid delivery system 370 in which one or more inks 372 , 374 may be printed in a desired pattern on to a substrate. Alternatively said ink system 350 may be printed by means of a screen process 377 in which an ink 380 is forced through a patterned aperture mask 378 onto a substrate 379 to form a desired pattern. Said ink pattern 360 when cured brings into proximity said semiconductive powder particles 355 to create a continuous percolated structure with semiconductive properties 365 .
[0067] Referring to FIG. 8 a system is depicted for causing a conductive or semiconductive trace 390 to be formed on substrate 388 in correspondence to an impinging light source 382 which may be steered by means of an optical beam steerer 384 . The operation of said system is based upon a microcapsule 386 which contains a metal or semiconductive salt in solution. Upon being exposed to light 382 which may be a UV light said metal or semiconductive salt is reduced to a metal or semiconductor and said microcapsule is simultaneously burst causing deposition of a conductive or semiconductive trace.
[0068] Referring to FIG. 9A , an ink jet system for depositing metallic or semiconductive traces 410 is depicted. In this system a jet containing a metal or semiconductive salt 420 impinges upon substrate 400 in conjunction with a jet containing a reducing agent 430 . As an example, to form a metallic trace silver nitrate (AgNO 3 ) may be used for jet 420 and a suitable aldehyde may be used for the reducing jet 430 . Many other examples of chemistries suitable for the present system are known in the art of electroless plating. In all such examples it is understood that said jets are moveable and controllable such that an arbitrary trace may be printed.
[0069] Referring to FIG. 9B a system which is similar to that of FIG. 9A is depicted. In this case an electron beam 470 may be used instead of said reducing jet in order to bring about a reduction of a metal or semiconductive salt emanating from a jet 460 . A ground plane 450 may be employed to ground said electron beam.
[0070] Referring to FIG. 9C an ink jet system for depositing a metallic or semiconductive trace is depicted based on electroplating. In this system a metal or semiconductive salt in a jet 480 held at a potential V may be electroplated onto a substrate 410 thus forming a metallic or semiconductive trace.
[0071] Referring to FIG. 9D means are known in the prior art for UV reduction of a metal salt from an ink jet head. In the present system a jet containing a metal or semiconductive salt 490 may be incident upon a substrate 400 in conjunction with a directed light beam 495 such that said metal or semiconductive salt is reduced into a conductive or semiconductive trace 410 . Alternatively jet 490 may contain a photoconductive material and a metal salt which may be caused to be photoconductively electroplated onto surface 400 by means of application of light source 495 as is known in the field of photoconductive electroplating.
[0072] Referring to FIG. 9E a system is depicted for a moveable deposition head 500 which contains a chamber 520 which may be filled with an inert gas via inlet 510 and which further contains thermal, sputtering, electron beam or other deposition means 530 . Said moveable head 500 may print a metal, semiconductor, insulator, spin material or other material in an arbitrary pattern onto a large class of substrates 540 . In some case such substrate 540 be cooled or chilled to prevent damage from said materials which may be at an elevated temperature.
[0073] Referring to FIG. 10 said previously described electronically active ink systems and printing means may be applied to form switch or logic structures, optoelectronic structures or structures useful in radio or magnetic or electric field transmission of signals or power. As indicated in FIGS. 10A-B an NPN junction transistor may be fabricated consisting of a n-type emitter 950 , a p-type base 954 and a n-type collector 952 .
[0074] Alternatively a field effect transistor may be printed such as a metal oxide semiconductor. Such a transistor consists of a p-type material 970 , an n-type material 966 an n-type inversion layer 968 an oxide layer 962 which acts as the gate a source lead 960 and a drain lead 964 . It is readily understood that multiple layers of logic may be printed by using an appropriate insulating layer between said logic layers. Further three dimensional interconnects between different logic layers may be accomplished by means of vias in said insulating layers.
[0075] Referring to FIG. 10D a printed solar cell may be fabricated by printing some or all of a metal contact layer 972 , a p-type layer 974 , an n type layer 976 and an insulating layer 978 . Light 979 which impinges upon said structure generates a current as is known in the art of solar cells. Such printed solar cells may be useful in very thin compact and/or inexpensive structures where power is needed.
[0076] Referring to FIGS. 10E-H elements useful for analog circuitry may be printed. Referring to FIG. 10E a capacitor may be printed with dielectric material 983 interposing capacitor plates 981 and 985 . Alternatively the same structure may constitute a resistor by replacing dielectric 983 with a resistive material such as carbon ink.
[0077] Referring to FIGS. 10E-H inductors, chokes or radio antennae may be printed layer by layer. Referring to FIGS. 10F and G a first set of diagonal electrodes 989 may be laid down on a substrate. On top of this may be printed an insulator or magnetic core 987 . Finally top electrodes 992 which connect with said bottom electrodes may be printed this forming an inductor, choke or radio antennae. An alternate in-plane structure is shown in FIG. 10H in which the flux field 995 is now perpendicular to the structure.
[0078] The ink systems and printing means discussed in the foregoing descriptions may be useful for the fabrication of a large class of electronically functional structures. FIGS. 11-14 depict a number of possible such structures which may be fabricated.
[0079] Referring to FIG. 11A , an electronic display, similar to one described in a copending patent application Ser. No. 08/504,896, filed Jul. 20, 1995 by Jacobson (now U.S. Pat. No. 6,124,851), is comprised of electronically addressable contrast media 640 , address lines 610 and 620 and logic elements 670 all or some of which may be fabricated with the ink systems and printing means as described in the foregoing descriptions. Said Electronic Display may additionally comprise a data receiver or transceiver block 672 and a power block 674 . Said data receiver block may further be a wireless radio receiver as pictured in FIG. 11B in which some or all of the components thereof including antennae 676 , inductor or choke 678 , diode, 680 , capacitor 682 , NPN transistor 684 , resistor 681 , conducting connection 677 or insulation overpass 675 may be printed by the means discussed above. Alternatively said data receiver or transceiver block may be an optoelectronic structure, a magnetic inductive coil an electric inductive coupling or an acoustic transducer such as a piezoresistive film.
[0080] Said power block 674 may comprise a printed polymer battery as pictured in FIG. 11C which consists of in one instance a lithium film 686 , a propylene carbonate LiPF 6 film 688 and LiCoO 2 in matrix 690 . Said power block may alternatively consist of any other battery structure as known in the art of thin structure batteries, a magnetic or electric inductive converter for means of power reception as known in the art, a solar cell which may be a printed solar cell or a semiconductive electrochemical cell which may further have an integral fuel cell for energy storage or a piezoelectric material which generates power when flexed.
[0081] Such a display 600 as described above further comprising a data receiver or transceiver 672 and power block 674 in which some or all of said components are printed may comprise an inexpensive, lightweight, flexible receiver for visual data and text which we may term “radio paper.” In such a system data might be transmitted to the “radio paper” sheet and there displayed thus forming a completely novel type of newspaper, namely one which is continuously updated.
[0082] Referring to FIG. 12 an electrostatic motor which may form an analog clock or watch is depicted which consists of printed conducting elements 720 , 730 , 740 and 760 which are printed onto substrate 700 . Said elements, when caused to alternately switch between positive negative or neutral states by means of a logic control circuit 710 may cause an element 750 to be translated thus forming a motor or actuator. In the device of FIG. 12 some or all of said conducting elements and/or logic control elements may be printed using the ink systems and printing means described in the foregoing description.
[0083] Referring to FIG. 13A a wrist watch 800 is depicted in which the band 820 of said watch contains an electronically addressable display 830 in which some or all of the components of said display, including the electronically addressable contrast media, the address lines and/or the logic are fabricated by means of the ink systems and printing means described in the foregoing description. Such a fabrication may be useful in terms of producing an inexpensive, easily manufacturing and thin display function. Control buttons 810 may serve to control aspects of said display 830 .
[0084] Referring to FIG. 13B it is presently a problem to transmit data or power to a watch band via a wire connection as such connections tend to become spoiled by means of motion of the watchband relative to the watch. In order to overcome this FIG. 13B describes a system in which a magnetic or electric inductor 832 in watch band 820 may receive or transmit power or data to a magnetic or electric inductor 834 in watch 800 thus eliminating said wired connection. Said inductor 832 and 834 may be printed structures.
[0085] Referring to FIG. 14 , a spin computer is depicted in which dipoles 912 with dipole moment 914 are situated at the nodes of row 920 and column 930 address lines. Such a computer works by means of initially addressing said dipoles to an initial condition by said address lines and then allowing dipole interactions to produce a final state of the system as a whole thus performing a calculation as is known in the art of Spin Ising models and cellular automata. Said dipoles may consist of a dipolar microsphere 912 microencapsulated in a microcapsule 910 or may consist of another form of dipole and/or another means of encapsulation.
[0086] While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.
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A system of electronically active inks is described which may include electronically addressable contrast media, conductors, insulators, resistors, semiconductive materials, magnetic materials, spin materials, piezoelectric materials, optoelectronic, thermoelectric or radio frequency materials. We further describe a printing system capable of laying down said materials in a definite pattern. Such a system may be used for instance to: print a flat panel display complete with onboard drive logic; print a working logic circuit onto any of a large class of substrates; print an electrostatic or piezoelectric motor with onboard logic and feedback or print a working radio transmitter or receiver.
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TECHNICAL FIELD
The invention relates to a device for coupling optical fibers and to a method for coupling optical fibers with the aid of such a device.
BACKGROUND
It is known to couple optical fibers in cassettes. Such cassettes for coupling optical fibers are known for example from U.S. Pat. No. 6,282,360 B1, it being possible for the optical fibers to be received by the cassettes with an excess length for a splicing reserve. The cassettes are designed in such a way that the excess lengths of the optical fibers can be received while at the same time a minimum bending radius is maintained. For access to the optical fibers in a cassette, it is known to form the cassette in such a way that it is movable in relation to a receiving element.
A device for coupling optical fibers in cassettes is also known from DE 102 55 561 A1. In a receiving element formed as a module, a number of cassettes are arranged in such a way that they can in each case be pivoted in relation to the receiving element and, in addition, are releasably connected to the receiving element. This makes it possible for the excess length or excess lengths of the optical fiber(s) received in the cassette to be unwound and for the connection of the optical fibers to be performed at a workplace specially prepared for this, which is spatially separate from the receiving element.
In the case of the known devices, the receiving element is in each case formed in a modular manner in such a way that it can receive a number of cassettes. However, the maximum number of cassettes that can be received is not variable. This means that this maximum number of cassettes that can be received is fixed when the receiving element is produced.
In the case of the known modular receiving elements, it is in each case provided that optical fibers, which are preferably led in to the receiving element by means of one or more buffered fibers, are led in largely from one direction. In the mentioned DE 102 55 561 A1, provided for this purpose is an opening which opens into a funnel-shaped channel, in which optical fibers led in by means of buffered fibers are individually separated and passed to the individual cassettes. A clearly arranged organization of individual optical fibers in the funnel-shaped channel is possible only with difficulty. In particular during servicing work, in which, following initial installation, individual optical fibers are to be exchanged or connected to different optical fibers than before, this is very disadvantageous. There is a high risk of individual optical fibers that are not specifically being worked on being damaged during such servicing work. Damage to these optical fibers is generally not noticed by the engineer carrying out the servicing, since not all the optical fibers connected to one another in all the cassettes can be checked after a servicing procedure on account of the great effort this involves.
Although a number of inlets are provided in the case of the device known from U.S. Pat. No. 6,282,360 B1, they likewise open out into a common leading-in channel, which however has a number of rudimentary guiding elements and additional guiding elements leading to the individual cassettes. Furthermore, there is a description of an embodiment in which the leading-in channel just described is formed doubly, the two leading-in channels formed being made to extend parallel to each other. A disadvantage of this embodiment is that the inner leading-in channel is covered by the outer leading-in channel, so that access to the inner leading-in channel during servicing work is in many cases impossible. In the other cases, access is at least not possible without all the optical fibers that are guided in the receiving element being greatly affected. There is consequently a high risk of optical fibers being damaged.
In the case of both known devices, it is provided that the one or more buffered fibers or the individual optical fibers are all led in to the receiving device largely from one direction. As a result, a clearly arranged and easy-to-service construction of a distributing unit in which these receiving elements are usually used together with the cassettes for coupling optical fibers is possible only with difficulty or not at all.
SUMMARY
The invention is based on the technical problem of providing a device and a method for coupling optical fibers with which a more simple, easier-to-service and more clearly arranged and more flexible construction of a distributing unit in which optical fibers are connected to one another is possible.
In a distributor or a distributing unit, an arrangement can be more clearly organized if led-in and led-away optical fibers are led in from different sides of the distributing unit of the device for coupling the optical fibers. The terms “leading in” or “led in” and “leading away” or “led away” are meant here in the mechanical sense or on the basis of a hierarchical network structure, since the transmission of information over the optical fibers generally takes place bidirectionally. The optical fibers led in from one side are consequently regarded as led-in optical fibers and the optical fibers mechanically guided on the other side of the distributor are regarded as led-away optical fibers. It is therefore envisaged according to the invention to provide a device for coupling optical fibers, comprising at least one receiving element for receiving a cassette, the cassette being connected to the at least one receiving element in such a way that it is movable in relation to it, and the cassette comprising at least one securing element for a coupling element, at which at least one of the optical fibers and at least one other of the optical fibers can be connected, the at least one receiving element being formed for receiving only the one cassette, and comprising two guiding devices, which make it possible for at least one of the optical fibers and at least one other of the optical fibers to be led in to the one cassette, the two guiding devices allowing the at least one of the optical fibers and the at least one other of the optical fibers to enter the at least one receiving element in different directions. This makes it possible that only the one cassette can be received in the at least one receiving element and the at least one of the optical fibers and the at least one other of the optical fibers are led in to the one cassette, which fibers run to the at least one receiving element from different directions, respectively via different guiding devices of the two provided, and the at least one of the optical fibers and the at least one other of the optical fibers are connected at the coupling element of the one cassette and the coupling element is arranged at the securing element of the one cassette. If, for example, one distributor is entered by a buffered fiber with a number of optical fibers which are connected to a further distributing unit and are regarded as led-in optical fibers, and by a further buffered fiber with other ones of the optical fibers, which lead to individual subscribers of an optically formed telephone network and are regarded as led-away optical fibers, the one buffered fiber and the other buffered fiber can be arranged on different sides of the distributor. The optical fibers individually separated from the two buffered fibers are then respectively led in to the at least one receiving element from different directions. During servicing of this distributing unit, searching for a specific optical fiber is made much easier. In addition to leading in the optical fibers that are used for different functions (for example on the one hand for forming a connection to a further distributing unit and on the other hand to terminating parties) from different directions, the optical fibers led to the at least one receiving unit and led away from it are led precisely to or away from the one cassette via the guiding devices. An incorrect assignment of optical fibers can be avoided more easily, so that a wrong connection or coupling of two of the optical fibers occurs more rarely or is ruled out. All the connections of the optical fibers and components used thereby for forming the connection and/or for protecting the connection are regarded as coupling elements. Securing elements may therefore be differently formed. Their purpose is to provide securement for connected optical fibers in the cassette.
An advantageous refinement of the invention provides that the guiding devices are formed as channels with respectively parallel side walls. These are designed in such a way that optical fibers are guided in the channels in such a way that the bending radius of the optical fibers does not at any point go below a minimum bending radius. In addition, the guiding channels preferably have lugs or projections under which the optical fibers can be held, so that they cannot fall out from the channels even in an arrangement in which, for example, gravitational forces act on the optical fibers. The parallel running side walls are preferably smooth and not interrupted, in order to facilitate threading in of optical fibers.
It is particularly preferred that the optical fibers enter the at least one receiving element not only from different directions but also enter it on different side faces of the receiving element. Therefore, a particularly preferred embodiment of the invention provides that each of the guiding devices comprises an opening and the openings of the guiding devices are formed on different side faces of the at least one receiving element. These may be opposite side faces or side faces which are oriented in relation to each other at an angle of 90°. For example, the side faces may be a side face and a rear face of the at least one receiving element.
In addition to permanent connections, which are formed by means of splicing optical fibers, the spliced connections of which are received in the cassettes, it is desirable for plug-in connections to be additionally provided in a distributing unit, allowing optical fibers to be coupled to one another in the distributing unit easily and quickly and releasably. Generally provided for this purpose in a distributing unit are patch fields, in which optical fibers which are provided with plug-in elements at one end can be releasably connected to one another. It is likewise possible to connect the individual optical fibers to one another in the cassettes by means of plug-in connections. It is usually provided that a led-in or led-away optical fiber is initially permanently coupled in the cassette by means of a spliced connection to a further optical fiber, which is connected at one end to a plug-in element for forming a plug-in connection. The end connected to the plug-in element must then generally be led into another cassette or to a patch field mentioned above. For a clearly arranged construction of a distributing unit, it is of advantage here if the guiding of these optical fibers can take place separately from the led-in or led-away optical fibers. Therefore, a particularly preferred embodiment of a device for coupling optical fibers provides that the at least one receiving element comprises a clearance and guiding elements, the clearance passing through the receiving element transversely in relation to guiding directions which are defined by the two guiding devices, and it being possible for the at least one receiving element to be arranged with further receiving elements, which in each case likewise comprise a clearance and guiding elements and can respectively be connected to a further cassette, to form a module in such a way that the clearances of the at least one receiving element and of the further receiving elements form a guiding channel and at least one additional one of the optical fibers, which is guided in the guiding channel, can be led in by means of the guiding elements to the one cassette of the receiving element. This means that, transversely in relation to the leading-in and leading-away of the optical fibers via the guiding devices of the at least one receiving element, there is created a guiding channel that is used for guiding preferably the optical fibers which are led from one cassette into another cassette or from a cassette to the patch field. It goes without saying that it is similarly possible to use this channel for leading optical fibers in or away and in this way separate the optical fibers if two separate buffered fibers are led in or two separate buffered fibers are led away from the distributing unit. It is similarly possible and preferred to guide in the guiding channel those optical fibers which are led between two cassettes, in order to be connected there to led-in or led-away optical fibers. The connection in the cassettes may take place by means of a permanent spliced connection or by means of a plug-in connection. The provision of the clearance in the at least one receiving element constitutes a self-evident invention. The fact that a number of the receiving elements can be arranged in a module is likewise self-evidently inventive and offers the further advantage that a distributing unit can be flexibly adapted and designed. Depending on the requirements, virtually any desired number of receiving elements with cassettes can be arranged in the distributing unit in one or more modules. In this way, it is possible for example for a module to be subsequently expanded, in that additional receiving elements which respectively enclose a cassette are added to the module or the modules. The receiving elements may be differently designed, for example adapted to cassettes of different sizes, which can receive a different number of optical fibers.
An embodiment in which the at least one receiving element is formed in the manner of a plate is particularly advantageous. To make a space-saving construction of a distributing unit possible, it may be provided that the clearance in the at least one receiving element is formed in such a way that, when a number of receiving units are arranged for forming the guiding channel, an angle other than 90° is obtained between an axis of the guiding channel and the individual guiding directions which are respectively fixed by the two guiding devices of the at least one receiving element. This allows in particular flat distributing units to be produced particularly easily.
A simple construction of the modules is made possible by the at least one receiving element being able to be connected with positive engagement to at least one of the further receiving elements by means of at least one latching connection.
It has proven to be particularly inexpensive and easy for expansion to form the at least one receiving element and the further receiving elements identically.
In order to protect the optical fibers which are guided in the guiding channel from damage and at the same time allow access to the optical fibers, for example for servicing purposes, in a development it is provided that the clearance is almost completely enclosed and on one side comprises a flexible, openable wall. The flexible, openable wall of the clearance is formed in such a way that it can preferably be easily opened with one finger. As a result, access to the optical fibers guided in the guiding channel is made possible during servicing work. Nevertheless, the optical fibers guided in the guiding channel are well protected against damage by the flexible walls and are reliably retained by them in the channel. The guiding channel or the clearances have additional openings, in order that optical fibers which are guided in the guiding channel can be led out from it and the optical fibers can be led by the guiding elements to the corresponding cassettes.
In order to make access possible to the ends of the optical fibers led in to the cassette, which are received in the cassette and are generally connected to one another, the cassette is connected to the at least one receiving element in a releasable and/or pivotable manner. It is generally advantageous to provide that the cassette is initially pivoted out from the receiving element and subsequently released from the receiving element, if appropriate, in order to bring the cassette and a connecting point at which the optical fibers are coupled to one another, preferably spliced, to a workplace. For this purpose, excess lengths of the optical fibers, which are received in the cassette, are unwound, in order to allow the cassette and the connecting point to be transported to the workplace, which is generally spatially separate from the receiving element. In the cassette, the optical fibers are guided in such a way that the bending radius cannot go below a minimum bending radius. Furthermore, it is provided that the at least one of the optical fibers and the at least one other of the optical fibers can be guided in the cassette in such a way that their ends can be connected to one another in a colinear manner at the securing element for the coupling element. The receiving element and the cassette are preferably designed in such a way that a pivoting movement of the cassette takes place about an axis which is oriented virtually perpendicular or perpendicular in relation to the guiding directions fixed by the guiding devices. In the case of a plate-like formation of the receiving element, there is a plane in which the receiving element has a maximum surface-area extent. The movement of the cassette preferably takes place in this plane or parallel to this plane.
In order to obtain both a releasable connection and a pivotable connection of the one cassette to the receiving element, in a preferred embodiment of the invention it is provided that the one cassette is connected to the at least one receiving element by means of a snap connection, about which the one cassette can be pivoted in a connected state. A snap connection can be easily released and additionally formed with a spindle, so that a pivoting movement can be performed about this spindle. Alternatively, the one cassette may be connected to the at least one receiving element by means of any desired other connection with positive engagement. A connection with positive engagement is characterized in that there is a plastically or elastically deformable element which, in a connected state, blocks one joining direction. For example, the cassette may have a ring-shaped hinge element, which can be fitted onto a cylindrical spindle located on the receiving element, with at least one flattening in a joining position. When the cassette is fitted on, a locking lug, for example, is elastically deformed. If the cassette is pivoted about the spindle, the locking lug returns to its original position and prevents the cassette from pivoting back into the joining position, in which the clearance of the ring-shaped hinge element is aligned with the at least one flattening of the spindle in such a way that the ring-shaped hinge element, and consequently the cassette, can be released from the spindle. Only if the locking lug is elastically deformed once again can the cassette consequently be moved into the joining position, in which it can be released again from the spindle. This deformation of the locking lug can preferably be achieved by exerting an increased pivoting moment.
In a preferred embodiment of the device, the module is an element of a distributing device used in communication technology, in particular telecommunication technology.
In a particularly advantageous development of the invention, the guiding elements are designed in such a way that at least one other of the optical fibers which is guided in the guiding channel in a direction opposed to a guiding direction of the at least one additional one of the optical fibers in the guiding channel can be led in to the one cassette. If it is assumed, without restricting generality, that the individual receiving elements are arranged one on top of the other to form a module, the guiding channel runs through the module from top to bottom. In this preferred embodiment, both optical fibers which enter the guiding channel from below and optical fibers which enter the guiding channel from above can be led in to the one cassette. In this case, the guiding elements are designed in such a way that the radius of curvature of the optical fibers does not go below a minimum radius of curvature. The leading in, for example, of the other of the optical fibers from “above” and of the additional optical fiber from “below” can take place simultaneously, so that for example in a distributing unit in which a patch field is respectively arranged both above and below the module, it is possible for example for two optical fibers which respectively have a plug-in element at their one end for forming a plug-in connection to be connected to each another in the upper patch field and the lower patch field in a cassette.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is explained in more detail below on the basis of a preferred exemplary embodiment with reference to the drawing, in which:
FIG. 1 shows a schematic view of a distributing unit used in communication technology;
FIG. 2 shows a perspective view of an embodiment of a device for coupling optical fibers;
FIG. 3 shows an isometric view of a receiving element of the device for coupling optical fibers as shown in FIG. 2 ;
FIG. 4 shows a side view of the receiving element as shown in FIG. 3 ;
FIG. 5 shows a front view of the receiving element as shown in FIGS. 3 and 4 along a direction indicated in FIG. 4 by means of an arrow A; and
FIG. 6 shows a plan view of the receiving element as shown in FIGS. 3 to 5 along a direction indicated in FIG. 4 by means of an arrow B.
DETAILED DESCRIPTION
In FIG. 1 , a distributing unit 1 used in communication technology, in particular telecommunication technology, is schematically represented. Enclosed in the distributing unit 1 is a device 2 for coupling optical fibers 8 , 9 , 12 . The device 2 comprises a module 3 . The module 3 comprises at least one receiving element 4 and preferably further receiving elements 4 a , which are respectively connected to precisely one cassette 5 or a further cassette 5 a . The cassette 5 and the further cassettes 5 a can in each case be received in the receiving elements 4 or in the further receiving elements 5 a . In the distributing unit 1 , optical fibers 8 , 9 are led in and led away via two buffered fibers 6 , 7 , respectively. In another embodiment, the optical fibers may be led in to the distributing unit 1 buffered in one buffered fiber. The buffered fibers 6 , 7 in each case comprise a number of the optical fibers 8 , 9 . In the distributing unit 1 , led-in optical fibers 8 , which are grouped together in the buffered fiber 6 and are, for example, connected with one end in a further telecommunication device (not represented), are directly and/or indirectly coupled to led-away optical fibers 9 , which are grouped together in the buffered fiber 7 and lead for example to different terminating parties of a telecommunication network. For this purpose, the led-in optical fibers 8 are respectively led in to the receiving elements 4 , 4 a from one side from one direction and the led-away optical fibers 9 are respectively led away from the corresponding receiving element 4 , 4 a from another side in another direction. In the receiving elements 4 , the led-in and led-away optical fibers 8 and 9 are respectively guided in two guiding devices to the cassettes 5 , 5 a , which are connected to the corresponding receiving elements 4 , 4 a , and guided in the cassettes 5 , 5 a in such a way that the ends of the led-in optical fibers 8 and of the led-away optical fibers 9 can be connected in a colinear manner at coupling elements. Excess lengths as working reserves and splicing reserves can be received in the cassettes 5 , 5 a . All connections of the optical fibers 9 and components used thereby for forming the connection and/or for protecting the connection are regarded as coupling elements.
The connections between the led-in optical fibers 8 and the led-away optical fibers 9 are preferably formed as permanent spliced connections at a splicing workplace. Such connections are referred to here as direct coupling or connection. However, it is similarly possible to connect the ends of the optical fibers 8 , 9 , 12 by plug-in elements, which in turn may form a plug-in connection. In addition, however, it is desirable to be able to connect individual led-in optical fibers 8 flexibly to other led-away optical fibers 9 in the distributing unit 1 . For this purpose, patch fields 10 , 11 are provided in the distributing unit. The patch fields 10 , 11 are designed in such a way that so-called patch fibers 12 , provided with plug-in elements, can be easily connected to one another at the patch fields 10 , 11 by means of releasable connections. These connections are referred to here as indirect connections. As a result, a high degree of flexibility of the distributing unit is made possible. In order to couple optical fibers at the patch fields 10 , 11 , it is customary to couple the led-in or led-away optical fibers 8 , 9 in one of the cassettes 5 , 5 a to the so-called patch fibers 12 , which are connected at one end to a plug-in element. The patch fibers 12 are guided in the module 3 by a guiding channel 13 , which is represented by dashed lines and is formed by clearances in the receiving elements 4 , 4 a . The guiding channel 13 runs transversely in relation to the leading-in directions, which are fixed by the guiding devices of the individual receiving elements 4 , 4 a for the led-in and led-away optical fibers 8 , 9 . This achieves the effect that the optical fibers performing different functions, led-in optical fibers 8 , led-away optical fibers 9 and patch fibers 12 , are guided in the distributing unit in such a way that they are well separated from one another. This facilitates servicing and later changing of couplings between the individual optical fibers 8 , 9 , 12 .
In FIG. 2 , an isometric view of an embodiment of a device 20 for coupling optical fibers is represented. The device 20 for coupling optical fibers comprises a module 21 . The module 21 comprises a receiving element 22 , preferably formed in the manner of a plate. The receiving element 22 is connected to precisely one cassette 23 , which can be received in a receiving element 22 . The receiving element 22 and further receiving elements 22 a , in which a further cassette 5 a is respectively received, are connected with positive engagement by means of latching connections 24 to form the module 21 . Furthermore, the receiving element 22 and the further receiving elements 22 a are connected to a rail 25 . The rail 25 serves the purpose of allowing the module 21 to be fastened in a distributing unit similar to that shown in FIG. 1 . In the embodiment described here, the receiving element 22 and the cassette 23 are in each case formed identically to the further receiving elements 22 a and further cassettes 23 a , respectively.
The cassettes 23 , 23 a are connected to the receiving elements 22 , 22 a by means of a snap connection 26 . The snap connections 26 are formed in such a way that the cassettes 23 , 23 a are pivotable about these snap connections 26 . In a pivoted-out state, in which the cassette 23 is represented, the snap connection 26 can be released, so that the cassette 23 can be separated from the associated receiving element 22 . In a received state, in which the cassettes 23 a are in, the cassettes 23 a are locked in the associated receiving elements 22 a . For this purpose, the cassettes 23 , 23 a in each case comprise a locking mechanism 27 , which comprises a resiliently mounted lug 28 . These resiliently mounted lugs 28 engage in the received state in locking clearances 29 in the corresponding receiving elements 22 , 22 a.
Each of the receiving elements 22 , 22 a comprises two guiding devices 30 , 31 , which in each case comprise an opening 32 , 33 . The openings 32 of the guiding devices 30 of the receiving elements 22 , 22 a are in each case located in a side face 34 and the openings 33 of the guiding devices 31 are located in another side face 35 . This makes it possible to guide optical fibers (not represented) that enter the receiving elements 22 , 22 a from different directions respectively to the cassettes 23 , 23 a by the guiding devices 30 , 31 . These different directions are preferably opposite directions. The guiding devices 30 , 31 are formed in the manner of channels and comprise parallel running side walls 36 . The side walls 36 are preferably formed such that they are smooth and uninterrupted. The guiding devices 30 , 31 can receive both optical fibers in the form of glass fibers and insulated conductors of a cable, i.e. glass fibers provided with protection. They are preferably designed in such a way that they can receive a number of glass fibers or cable conductors. Furthermore, the guiding devices 30 , 31 are designed in such a way that the bending radius of the optical fibers does not at any point in the guide go below a minimum bending radius.
The cassettes 23 , 23 a comprise cassette guides 37 , in order to guide the optical fibers that are led in to the respective cassette 23 , 23 a in the cassettes 23 , 23 a . The cassette guides 37 are designed in such a way that excess lengths of the optical fibers can be received and the optical fibers can be guided in such a way that the ends of two optical fibers in each case can be connected in a colinear manner at securing elements 38 for coupling elements. In the exemplary embodiment represented, the cassettes 23 , 23 a are formed in such a way that they comprise securing elements 38 for coupling elements for receiving spliced connections for in each case four unsheathed glass fibers and/or for cable conductors. The actual configuration of the cassette guides 37 and the choice of the number and configuration of the securing elements 38 can be adapted to correspond to the respective requirements.
The receiving elements 22 , 22 a in each case also comprise a clearance 39 , which respectively passes through the receiving elements 22 , 22 a . The clearances 39 of the receiving elements 22 , 22 a arranged against each other form a guiding channel 40 , which runs transversely in relation to guiding directions which are fixed by the guiding devices 30 , 31 of the receiving elements 22 , 22 a . The guiding directions respectively run in planes parallel to each other, which are defined by the receiving elements 22 , 22 a formed in the manner of plates. The guiding channel 40 runs transversely in relation to the planes formed by the plate-like receiving elements 22 , 22 a . The clearances 39 are in each case formed at the edge of the receiving elements 22 , 22 a but are almost completely enclosed. One wall of the clearances 39 is in each case advantageously formed as a flexible, openable wall 41 . The guiding channel 40 is consequently closed, but can easily be at least partly opened with a finger for servicing work. In addition, the clearances 39 have openings through which the optical fibers can be led to the cassettes 23 , 23 a.
The receiving elements 22 , 22 a also comprise guiding elements 42 . The guiding elements 42 of the receiving elements 22 , 22 a are designed in such a way that they make it possible for optical fibers which are guided in the guiding channel 40 to be led to the cassettes 23 , 23 a in such a way that the radius of curvature of the optical fibers does not go below a minimum radius of curvature. They are advantageously formed in such a way that both optical fibers which are led into the channel “from below” and optical fibers which are led into the channel “from above” can be led to the cassettes 23 , 23 a . The guiding elements 42 are designed in such a way that it is easily possible for optical fibers to be laid. The guiding elements 42 are even accessible when the receiving elements 22 , 22 a are latched to each other with positive engagement.
In FIG. 3 , an isometric view of the receiving element 22 of the device for coupling optical fibers as shown in FIG. 2 is represented. The one cassette, assigned to the receiving element 22 , has been removed from the receiving element 22 and is not represented. The same technical features are provided with the same designations in FIGS. 2 to 6 . The two guiding devices 30 , 31 and the clearance 39 , one wall of which is formed as a flexible, openable wall 41 , can be plainly seen. The locking clearance 29 , in which the resiliently mounted lug of the associated cassette latches in a received position of the cassette, can also be seen. Between the guiding devices 30 , 31 , a rail guiding clearance 43 can be seen. The rail guiding clearance 43 is designed in such a way that it is adapted to the profile of the rail 25 as shown in FIG. 2 , with which a module formed by a number of receiving elements 22 can be fastened. In the exemplary embodiment represented, the rail guiding clearance 43 is formed in such a way that the receiving element 22 can be pushed onto the rail 25 as shown in FIG. 2 . An alternative configuration of the rail guiding clearance may be designed in such a way that a latching connection or snap connection with the rail can be produced.
In FIG. 4 , a side view of the receiving element 22 as shown FIG. 3 is represented. The receiving element 22 is oriented in such a way that it can be pushed over a perpendicularly aligned rail for securing the receiving elements 22 joined together to form a module. This means that a plane defined by the receiving element 22 formed in the manner of a plate has an angle of inclination with respect to the rail of approximately 60°. An extent which is indicated by means of a double-headed arrow 44 is hereby reduced in comparison with an embodiment in which the angle of inclination is 90°, so that, for example, it is possible for it to be installed in a distributing unit as shown in FIG. 1 , which has only a small depth.
In FIG. 5 , the front view of the receiving element as shown in FIGS. 3 and 4 is represented. A viewing direction extends along an arrow A, which is represented in FIG. 4 .
In FIG. 6 , a plan view with a viewing direction along an arrow B as shown in FIG. 4 of the receiving element 22 as shown in FIGS. 3 to 5 is represented. The two guiding devices 30 , 31 and the guiding channel 40 formed by the clearance 39 are hatched. The guiding directions of optical fibers are indicated by arrows 45 , a point in a circle indicating out of the plane of the figure and a cross surrounded by a circle representing an arrow into the plane of the figure.
The cassettes and receiving elements are preferably in each case produced in one piece. It is preferred for them to be produced from plastic, for example by means of an injection-molding process.
Even if it is not preferred, it is possible for the optical fibers to be led into a cassette or away from it in the receiving element by one and the same of the two guiding devices or the guiding channel.
LIST OF DESIGNATIONS
1 distributing unit
2 device for coupling optical fibers
3 module
4 receiving element
4 a further receiving element
5 cassette
5 a further cassette
6 led-in buffered fiber
7 led-away buffered fiber
8 led-in optical fiber
9 led-away optical fiber
10 patch field
11 patch field
12 patch fiber
13 guiding channel
20 device for coupling optical fibers
21 module
22 receiving element
22 a further receiving element
23 cassette
23 a further cassette
24 latching connection
25 rail
26 snap connection
27 locking mechanism
28 lug
29 locking clearance
30 guiding device
31 guiding device
32 opening
33 opening
34 side face
35 other side face
36 side wall
37 cassette guide
38 securing element
39 clearance
40 guiding channel
41 flexible, openable wall
42 guiding elements
43 rail guiding clearance
44 double-headed arrow for indicating an extent
45 arrows for indicating guiding directions
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A device for coupling optical waveguides includes at least one element for accommodating a cartridge. The cartridge is connected to the at least one accommodating element so as to be movable relative thereto while being provided with at least one mounting element for a coupling element to which at least one of the optical waveguides and at least one other optical waveguide can be connected. The at least one accommodating element is embodied so as to accommodate only one cartridge while encompassing two guiding mechanisms which allow the at least one optical waveguide and at least one other optical waveguide to be delivered to the cartridge. The optical waveguides, which run into the at least one accommodating element from different directions, are delivered to the one cartridge via a different of the two guiding mechanisms. The optical waveguides are connected at the coupling element of the cartridge, said coupling element being disposed on the mounting element of the cartridge.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to turbine rotor assemblies and more particularly to methods and apparatus for relieving stress at a tip shroud of rotating airfoils used with turbine rotor assemblies.
[0002] At least some known turbine rotor assemblies include a plurality of rotor blades or buckets (hereinafter, the term “bucket” shall be used to refer generically to a turbine bucket or an aircraft engine blade) that extend from a root to a tip shroud. Generally, tip shrouds facilitate improving the performance of the turbine rotor assembly. During operation, tip shrouds are subject to high thermal and mechanical loading which induce stresses into the tip shrouds which must be addressed to maintain the useful life of the blade.
[0003] To facilitate reducing stresses induced to tip shrouds, at least some known bucket tip shrouds are scalloped such that selected portions of the tip shroud are removed. For example, it is known to remove portions of the tip shroud along the leading edge and/or trailing edge of the tip shroud during a scalloping process. Although the scalloped areas facilitate reducing mechanical loading, and thus stresses, induced to the tip shrouds, scalloping the tip shrouds may adversely affect the performance of the engine.
BRIEF DESCRIPTION OF THE INVENTION
[0004] In one aspect, a method of assembling a rotor assembly is provided. The method includes coupling a first turbine bucket to a rotor disk wherein the first turbine bucket includes a first tip shroud including a first surface, providing a second turbine bucket that includes a second tip shroud including a second surface, and coupling the second turbine bucket to the rotor disk such that the second turbine bucket is circumferentially adjacent to the first turbine bucket and such that during operation of the rotor assembly the first tip shroud contacts the second tip shroud along the first and second surfaces to enable at least one of a portion of radial loading induced to the first tip shroud to be transferred to the second tip shroud and a portion of radial loading induced to the second tip shroud to be transferred to the first tip shroud.
[0005] In a further aspect, a rotor assembly is provided. The rotor assembly includes a first turbine bucket including a first tip shroud extending from a radially outer end of the first turbine bucket. The first tip shroud includes a first surface. The rotor assembly also includes a second turbine bucket including a second tip shroud extending from a radially outer end of the second turbine bucket. The second tip shroud is positioned circumferentially adjacent to the first tip shroud. The second tip shroud includes a second surface configured to transfer at least one of a portion of radial loading induced to the second tip shroud to the first tip shroud and a portion of radial loading induced to the first tip shroud to the second tip shroud.
[0006] In a further aspect, a turbine bucket assembly is provided. The turbine bucket assembly includes a turbine bucket and a tip shroud extending from a radially outer end of the turbine bucket. The tip shroud includes a leading edge and an opposing trailing edge such that a first circumferential side and an opposing second circumferential side each extend between the leading edge and the trailing edge. The tip shroud further includes at least one tip rail extending between the first and second circumferential side. The turbine bucket assembly also includes a first surface and a second surface each extending along a portion of at least one of the first circumferential side, the at least one tip rail, the leading edge, and the trailing edge. The first and second surfaces are configured to enable radial load transfer from the first tip shroud to an adjacent second tip shroud.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a perspective view of an exemplary bucket that may be used with an axial flow turbine;
[0008] FIG. 2 is a perspective view of a portion of a pair of the buckets shown in FIG. 1 and coupled in position within a turbine rotor assembly;
[0009] FIG. 3 is a perspective top view of an exemplary bucket tip shroud shown in FIG. 2 ; and
[0010] FIG. 4 is a perspective bottom view of the bucket tip shroud shown in FIG. 3 .
DETAILED DESCRIPTION OF THE INVENTION
[0011] As used herein, an element or step recited in the singular and proceeded with the word “a,” “an,” or “one” (and especially, “at least one”) should be understood as not excluding plural said elements or steps, unless such exclusion is explicitly stated. Furthermore, references to “one embodiment” (or to “other embodiments”) of the present invention are not intended to be interpreted as excluding either the existence of additional embodiments that also incorporate the recited features or of excluding other features described in conjunction with the present invention. Moreover, unless explicitly stated to the contrary, embodiments “comprising” or “having” an element or a plurality of elements having a particular property may include additional such elements not having that property.
[0012] FIG. 1 is a perspective view of a turbine bucket 100 that may be used with an axial flow turbine. In an exemplary embodiment, each bucket 100 includes an airfoil 42 and an integrally-formed dovetail 43 used for mounting airfoil 42 to a rotor disk (not shown).
[0013] Airfoil 42 includes a first sidewall 44 and a second sidewall 46 . First sidewall 44 is concave and defines a pressure side of airfoil 42 , and second sidewall 46 is convex and defines a suction side of airfoil 42 . Sidewalls 44 and 46 are connected at a leading edge 48 and at an axially-spaced trailing edge 50 of airfoil 42 that is downstream from leading edge 48 .
[0014] First and second sidewalls 44 and 46 , respectively, extend longitudinally or radially outward to span from a blade root 52 positioned adjacent dovetail 43 . In the exemplary embodiment, airfoil 42 and blade root 52 are fabricated as a unitary component. In an alternative embodiment, airfoil 42 and root 52 are not fabricated as a unitary piece. In the exemplary embodiment, bucket 100 includes a tip shroud 212 . Bucket 100 is coupled to a rotor shaft and extends radially outward from the rotor shaft. In an alternative embodiment, bucket 100 may be coupled to a rotor shaft by other devices configured to couple a bucket to a rotor shaft, such as, a blisk.
[0015] FIG. 2 is a perspective view of a portion of a pair of circumferentially-adjacent buckets 100 and 101 coupled in position within a turbine rotor assembly. FIG. 3 is a perspective top view of tip shroud 212 . FIG. 4 is a perspective bottom view of tip shroud 212 .
[0016] Specifically, in the exemplary embodiment, buckets 100 and 101 are substantially identical and each includes tip shroud 212 . For simplicity, a first bucket is identified as bucket 100 and a second bucket is identified as bucket 101 . Bucket 100 includes a first tip shroud 212 and bucket 101 includes a second tip shroud 214 . As described in more detail below, tip shroud 212 is sized and oriented at the time of manufacture to cooperate and mate against a portion of tip shroud 214 . Moreover, as described in more detail below, in the exemplary embodiment, a portion of first tip shroud 212 is configured to support a radial load from second tip shroud 214 that is circumferentially adjacent to first tip shroud 212 .
[0017] As shown in FIG. 2 , each tip shroud 212 and 214 includes a first sidewall 234 and an opposite circumferentially-spaced second sidewall 238 that are connected together via a leading edge side 240 and an opposite trailing edge side 242 . In the exemplary embodiment, neither leading edge side 240 nor trailing edge side 242 are scalloped. Leading and trailing edge sides 240 and 242 each extend circumferentially between first and second sidewalls 234 and 238 , respectively. In the exemplary embodiment, each tip shroud 212 and 214 includes a pair of tip rails 241 and 243 . In an alternative embodiment, each tip shroud 212 and 214 includes one tip rail.
[0018] As shown in FIG. 3 , in the exemplary embodiment, first sidewall 234 is formed with an overhang portion 250 that is defined along a portion of first sidewall 234 . Specifically, in the exemplary embodiment, overhang portion 250 extends from leading edge side 240 towards trailing edge side 242 . As shown in FIG. 4 , in the exemplary embodiment, overhang portion 250 extends a distance D 1 from leading edge side 240 towards trailing edge side 242 . First sidewall 234 is also formed with a notch 252 . Specifically, in the exemplary embodiment, notch 252 is defined by a first end 254 and a second end 255 that are connected together at an apex 253 . In the exemplary embodiment, notch 252 is a Z-notch that extends continuously from first end 254 to second end 255 . As such, in the exemplary embodiment, overhang portion 250 extends from leading edge side 240 to notch first end 254 .
[0019] Overhang portion 250 is formed by a recess 257 that extends a width W 1 from first sidewall 234 towards second sidewall 238 and along a radially inner surface 251 . In the exemplary embodiment, a radially outer surface 245 is offset a distance (not shown) outboard from radially outer surface 244 of leading edge 240 . Overhang portion radially inner surface 251 forms a mating surface that enables circumferentially-adjacent tip shrouds 212 and 214 to abut each other, as described in more detail below.
[0020] First sidewall 234 is also formed with an undercut portion 260 that extends along a portion of first sidewall 234 . Specifically, in the exemplary embodiment, undercut portion 260 extends from trailing edge side 242 towards leading edge side 240 . More specifically, in the exemplary embodiment, undercut portion 260 extends a distance D 3 from trailing edge side 242 to apex 253 . In an alternative embodiment, undercut portion 260 extends from trailing edge side 242 to a projection 261 is positioned adjacent notch second end 255 . In the exemplary embodiment, distance D 3 is approximately equal to distance D 1 . In an alternative embodiment, distance D 3 is different than distance D 1 .
[0021] Undercut portion 260 is defined by a recessed area 263 that extends a width W 2 from first sidewall 234 towards second sidewall 238 and along a radially outer surface 264 . Undercut portion radially outer surface 264 forms a mating surface that enables circumferentially adjacent tip shrouds 212 and 214 to abut each other, as described in more detail below.
[0022] Second sidewall 238 includes an undercut portion 270 , a projection 271 , a notch 272 , and an overhang portion 274 . In the exemplary embodiment, undercut portion 270 , notch 272 , and overhang portion 274 are formed similarly to undercut portion 260 , notch 252 , and overhang portion 250 in that each is sized, shaped, and oriented to mate against a respective circumferentially-adjacent overhang portion 250 , notch 252 , and undercut portion 260 . More specifically, in the exemplary embodiment, undercut portion 270 extends from leading edge side 240 towards trailing edge side 242 . Specifically, undercut portion 270 extends a distance D 5 from leading edge side 240 towards trailing edge side 242 . Specifically, undercut portion 270 extends from leading edge side 240 to an apex 279 . Alternatively, undercut portion 270 extends from leading edge side 240 to projection 271 . In the exemplary embodiment, distance D 5 is substantially equal to distance D 3 of undercut portion 260 . In an alternative embodiment, distance D 5 is different than undercut portion distance D 3 . Second sidewall 238 is also formed with a notch 272 that is defined by a first end 276 and a second end 278 that are connected together at apex 279 . In the exemplary embodiment, notch 272 is a Z-notch extending continuously from first end 276 to second end 278 . As such, in the exemplary embodiment, undercut portion 270 extends from leading edge side 240 to projection 271 near notch second end 278 .
[0023] Undercut portion 270 is defined by a recessed area 273 that extends a width W 3 from second sidewall 238 towards first sidewall 234 and along shroud a radially outer surface 280 . Undercut portion radially outer surface 280 forms a mating surface that enables circumferentially adjacent tip shrouds 212 and 214 to abut each other, as described in more detail below.
[0024] Additionally, second sidewall 238 is formed with overhang portion 274 that extends along a portion of second sidewall 238 . Overhang portion 274 extends from trailing edge side 242 towards leading edge side 240 . In the exemplary embodiment, overhang portion 274 extends a distance D 6 from trailing edge side 242 towards leading edge side 240 . In the exemplary embodiment, distance D 6 is substantially equal to distance D 1 of overhang portion 250 . In an alternative embodiment, D 6 is different than overhang portion distance D 1 . Specifically, overhang portion 274 extends from trailing edge side 242 to first end 276 of notch 272 . Overhang portion 274 is formed by a recess 282 that extends a width W 4 from second sidewall 238 towards first sidewall 234 and along a shroud radially inner surface 284 . Overhang portion radially inner surface 284 forms a mating surface that enables circumferentially-adjacent tip shrouds to abut each other, as described in more detail below.
[0025] In the exemplary embodiment, first sidewall 234 is designed to mate against second sidewall 238 such that a portion of radial loading induced to tip shroud 212 is transferred to tip shroud 214 . Specifically, overhang portion 250 is designed to mate against undercut portion 270 , and overhang portion 274 is designed to mate against undercut portion 260 . In the exemplary embodiment, overhang portions 250 and 274 are designed to ensure overlap with undercut portions 270 and 260 , respectively. It should be noted that the orientation and configurations of tip shrouds 212 and 214 is the exemplary embodiment. For example, in an alternative embodiment, neither tip shroud 212 nor tip shroud 214 is formed with overhang portions 250 and 274 or with undercut portions 260 and 270 . In an alternative embodiment, tip shroud first sidewall 234 is formed with a first surface that is positionable relative to tip shroud second sidewall 238 to enable the first surface and second surface to contact during operation of the rotor assembly such that a portion of radial loading induced to tip shroud 212 is transferred to tip shroud 214 . In another alternative embodiment, for example, at least one of tip shroud 212 and/or tip shroud 214 includes, but is not limited to including, circumferential pins, tabs, and/or any other suitable mechanisms that enables a portion of radial loading induced to tip shroud 212 to be translated to tip shroud 214 .
[0026] In an alternative embodiment, leading edge 240 includes overhang portion 250 and undercut portion 260 , and/or trailing edge 242 includes overhang portion 274 and undercut portion 270 wherein a portion of radial loading induced to tip shroud 212 is transferred to tip shroud 214 . In a further alternative embodiment, tip rail 241 includes overhang portion 250 and undercut portion 260 , and/or tip rail 243 includes overhang portion 274 and undercut portion 270 wherein a portion of radial loading induced to tip shroud 212 is transferred to tip shroud 214 .
[0027] During assembly, in the exemplary embodiment, buckets 100 and 101 are positioned circumferentially adjacent one another such that tip shrouds 212 and 214 are positioned circumferentially adjacent to each other. More specifically, when aligned, the leading edge side 240 of tip shroud 212 is substantially circumferentially aligned with the leading edge side 240 of tip shroud 214 . As such, first sidewall 234 of tip shroud 212 is positioned circumferentially adjacent second sidewall 238 of tip shroud 214 . More specifically, in the exemplary embodiment, when tip shrouds 212 and 214 are adjacent to each other, radially inner surface 251 of overhang portion 250 is aligned with radially outer surface 280 of undercut portion 270 , projection 271 is aligned with the walls within notch 252 , and apex 279 receives projection 261 . Furthermore, radially outer surface 264 of recessed area 263 of undercut portion 260 is aligned with radially inner surface 284 of recess 282 of overhang portion 274 . Positioning undercut portions 260 and 270 and overhang portions 250 and 274 in a mating relationship with one another facilitates increasing the useful life of tip shrouds 212 and 214 , and thus prevents the inclusion of scallops and/or other weakening cut away portions of tip shrouds 212 and 214 . Prior to thermal expansion of buckets 100 and 101 , first sidewall 234 of tip shroud 212 is aligned with adjacent second sidewall 238 of tip shroud 214 . Tip shrouds 212 and 21 4 are positioned to contact one another during operation of the turbine.
[0028] During operation of a turbine, air flows along tip shrouds 212 and 214 and from leading edge 240 towards trailing edge side 242 . As tip shrouds 212 and 214 thermally and mechanically expand, overhang portions 250 and 274 facilitate resisting radially outward movement of undercut portions 260 and 270 such that stresses induced to tip shrouds 212 and 214 during turbine operation are reduced. During operation, the combination of overhang portions 250 and 274 , and undercut portions 260 and 270 , transmit tip shroud centrifugal loading into each corresponding bucket 100 and 101 . Specifically, in the exemplary embodiment, a portion of radial loading induced to tip shroud 212 is transferred to tip shroud 214 , or a portion of radial loading induced to tip shroud 214 is transferred to tip shroud 212 . Moreover, in the exemplary embodiment, a portion of radial loading induced to tip shroud 212 is transferred to tip shroud 214 , and a portion of radial loading induced to tip shroud 214 is simultaneously transferred to tip shroud 212 . The enhanced radial retention enables a manufacturer to prevent from having to scallop the leading and/or trailing edges of the tip shroud. Additionally, the radial retention facilitates preventing a fillet (not shown) located between the airfoil and tip shroud from being solely responsible for carrying the load of the tip shroud. By reducing and lowering stresses in tip shroud 212 and 214 , the useful life of the tip shrouds is facilitated to be increased.
[0029] The above-described invention provides an overlapping tip shroud assembly that facilitates reducing stresses induced within the tip shroud. Reducing stresses within the tip shroud facilitates increasing the useful life of the tip shroud white maintaining engine performance.
[0030] An exemplary embodiment of a turbine rotor assembly is described above in detail. The assembly illustrated is not limited to the specific embodiments described herein, but rather, components of each assembly may be utilized independently and separately from other components described herein.
[0031] While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.
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A method of assembling a rotor assembly is provided. The method includes coupling a first turbine bucket to a rotor disk wherein the first turbine bucket includes a first tip shroud including a first surface, providing a second turbine bucket that includes a second tip shroud including a second surface, and coupling the second turbine bucket to the rotor disk such that the second turbine bucket is circumferentially adjacent to the first turbine bucket and such that during operation of the rotor assembly the first tip shroud contacts the second tip shroud along the first and second surfaces to enable at least one of a portion of radial loading induced to the first tip shroud to be transferred to the second tip shroud and a portion of radial loading induced to the second tip shroud to be transferred to the first tip shroud.
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This application is the National Phase of PCT/EP2007/060796 filed on Oct. 10, 2007, which claims priority under 35 U.S.C. 119(e) to U.S. Provisional Application No. 60/851,011filed on Oct. 11, 2006 and under 35 U.S.C. 119(a) to Patent Application No. EP 06122143.8 filed in Europe on Oct. 11, 2006, all of which are hereby expressly incorporated by reference into the present application.
The present invention relates to a process for the manufacture of polymorph B of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide.
BACKGROUND OF THE INVENTION
N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide is a potent ligand of γ-aminobutyric acid A (GABA A ) receptors useful in the treatment or prevention of anxiety, epilepsy, sleep disorders, and insomnia, for inducing sedation-hypnosis, anesthesia, and muscle relaxation, and for modulating the necessary time to induce sleep and its duration, such as described in PCT/EP2006/063243 and U.S. 60/692866.
Throughout the present application the term “compound (I)” refers to N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide. Crystal form of compound (I) obtained in the above applications is coded here polymorph A.
This form of compound (I) shows a melting point of 165-167° C. In the present research this form showed a DSC with a sharp melting peak between 166.2° C. and 167.4° C. The slight difference with the previously reported melting point is acceptable and is within the range of experimental error. This form is coded here polymorph B.
SUMMARY OF THE INVENTION
The present invention concerns a process for the industrial manufacture of a new form of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide, polymorph B, which comprises the synthesis in situ of compound (I) followed by addition of a (C 1 -C 4 )-alcohol to the reaction mixture to cause the precipitation of the final product, which is isolated as a solid by filtration.
Polymorph B of compound (I) shows a powder X-Ray diffraction pattern containing the most intense peaks at 2θ=7.1°(±0.1°) and 21.4°(±0.1°). Polymorph B of compound (I) also shows a FT-Raman Spectrum with characteristic signals at 3107 cm −1 , 1605 cm −1 , 1593 cm −1 , 1538 cm −1 , 1336 cm −1 , and 102 cm −1 and a Differential Scanning Calorimetry with a melting peak at approximately 158° C.
In comparison with polymorph A, polymorph B of compound (I) can be conveniently handled and processed because of its higher stability. This is of importance, not only from the point of view of obtaining a commercially viable manufacturing process, but also from the point of subsequent manufacture of pharmaceutical formulations comprising the active compound. The drug substance, and compositions containing it, are capable of being effectively stored over appreciable periods of time, without exhibiting a significant change in the active component's physicochemical characteristics.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention is described in connection with the appended drawings in which:
FIG. 1 is the Powder X-Ray Diffraction curve of polymorph B. The Intensity, on the ordinate, is expressed in cps.
FIG. 2 is the Fourier-Transform Raman (FT-Raman) Spectrum of polymorph B.
FIG. 3 is the Differential Scanning Calorimetry (DSC) curve of polymorph B.
DETAILED DESCRIPTION OF THE INVENTION
The applicants have discovered that the preparation of compound (I) in situ by reaction of (5-amino-1H-pyrazol-4-yl)-thiophen-2-yl-methanone and N-[5-(3-dimethylamino-acryloyl )-2-fluoro-phenyl]-N-methyl-acetamide in acetic acid, followed with addition of a (C 1 -C 4 )-alcohol such as 2-propanol, in combination with selected operating conditions, is of great importance in enabling a final substance to be obtained smoothly without problems of reproducibility, quality and yield.
According to the present invention, a more efficient industrial manufacturing process is provided which affords high yield and constant purity standards kilogram-scale preparations of polymorph B of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1, 5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide which circumvents the above-mentioned problems. Thus, in a first embodiment, the present invention consists in a process for the industrial manufacture of polymorph B of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1, 5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide which comprises the following steps:
(i) reacting (5-amino-1H-pyrazol-4-yl)-thiophen-2-yl-methanone with N-[5-(3-dimethylamino-acryloyl)-2-fluoro-phenyl]-N-methyl-acetamide in a solvent selected from the group consisting of acetic acid, propionic acid, and formic acid at a temperature ranging from 50° C. to the boiling point of the mixture; (ii) adding a (C 1 -C 4 )-alcohol such as methanol, ethanol, 2-propanol, or 1-propanol; at a temperature comprised between 40° C. and 80° C.; (iii) aging for at least 30 min. at a temperature comprised between 30 and 55° C. to initiate the crystallization; and (iv) recovering the crystallized product.
Step (I) of the process can also be carried out in an alcohol such as methanol, ethanol, 2-propanol, 1-propanol; dimethylformamide or dimethylsulfoxide.
In a particular embodiment, the process comprises the following steps:
(i) the reaction of (5-amino-1H-pyrazol-4-yl)-thiophen-2-yl-methanone and N-[5-(3-dimethylamino-acryloyl)-2-fluoro-phenyl]-N-methyl-acetamide in acetic acid at a temperature ranging from 100° C. to the boiling point with stirring, under nitrogen medium; (ii) cooling the reaction mixture to 40-80° C. and adding 2-propanol; (iii) cooling the reaction mixture to 30-55° C.; and aging for ½ to 2 hours; (iv) cooling the reaction mixture over 2-3 hours to 0-10° C.; aging for 1 to 4 hours; filtering and washing the resulting crystalline material with 2-propanol; and drying the product under vacuum at 40-60° C.
In another embodiment, the preferred process temperature in step (i) is comprised between 115° C. and 125° C. In another particular embodiment, the preferred temperature is 100° C.
In another embodiment, the reaction mixture in step (ii) is cooled to 60-70° C.
In another embodiment, the reaction mixture in step (iii) is cooled to 40-45° C.
In another embodiment, the aging in step (iii) takes at least 1 hour.
In another embodiment, the crystallized product is recovered by cooling the mixture at a temperature comprised between 0 and 10° C., followed by filtering the obtained product. In a more preferred embodiment, the reaction mixture in step (iv) is cooled for at least 1 hour to 0-5° C.
In another embodiment, the aging in step (iv) takes at least 2 hours, preferably, over 2.5 hours.
In another embodiment, the product in step (iv) is dried at a temperature comprised between 45 and 55° C.
The invention and the best mode of carrying out the same are illustrated by the following non-limitative example.
EXAMPLE 1
Polymorph B of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide
A 300 L vessel was flushed with nitrogen. Acetic acid (40.0 L) was charged, and then 7.312 kg (37.84 moles) of (5-amino-1H-pyrazol-4-yl)-thiophen-2-yl-methanone and 10.000 kg (37.84 moles) of N-[5-(3-dimethylamino-acryloyl)-2-fluoro-phenyl]-N-methyl-acetamide were added consecutively. The mixture was heated to 120° C. (±5° C.) with stirring. The reaction was controlled by HPLC until completion (<1% of each starting material), which typically occurs in 4 hours. The reaction mass was cooled to 60-70° C. 2-Propanol (80.0 L) was charged to reaction mixture, cooled to 40-45° C. and aged for at least 1 hour. The mixture was cooled over approximately 2.5 hours to 0-5° C. and aged for at least 2 hours. Solids were filtered and washed twice with 10.0 L of chilled 2-propanol. The solid product was dried under vacuum at 50° C. (±5° C.) to remove residual solvents (<0.5% w/w of acetic acid and <0.5% w/w of 2-propanol). N-{2-fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide was obtained as a crystalline material (12.686 kg). Yield 85%. Purity ≧95%.
1 H NMR(400 MHz, CDCl 3 ): δ 1.98 (3H, s,), 3.3 (3H, s), 7.13 (1H, d, J=4 Hz), 7.18-7.20 (1H, m), 7.42 (1H, t, J=8.8 Hz), 7.71 (1H, d, J=5.2 Hz), 8.02-8.08 (2H, m), 8.12 (1H, dd, J=2.4 and 7.6 Hz), 8.71 (1H, s), 8.82 (1H, d, J=4 Hz).
MS (ES) m/z=395 (MH + )
The obtained crystalline material was identified as polymorph B using the following procedures.
Instrumental and Experimental Conditions
Powder X-Ray Diffraction: Bruker D8 Advance. Cu Kα radiation; tube power 35 kV/45 mA; detector VANTEC1; 0.017° 2θ step size, 105±5 s per step, 2°-50° 2θ scanning range (printed range may be different). Silicon single crystal sample holders were used, sample diameter 12 mm, depth 0.1 mm.
FT-Raman Spectroscopy: Bruker RFS100. Nd:YAG 1064 nm excitation, 100 mW laser power, Ge-detector, 64 scans, range 50-3500 cm −1 , 2 cm −1 resolution, Aluminum sample holder.
Differential Scanning Calorimetry: Perkin Elmer DSC 7. Gold crucibles, heating rates of 2 C min −1 or 10° C. min −1 , varying start and end temperatures.
Single-Crystal X-Ray Diffraction: The crystal was measured on a Nonius Kappa CCD diffractometer at 173° K. using graphite-monochromated Mo Kα radiation with λ=0.71073 Å. The COLLECT suite was used for data collection and integration. The structure was solved by direct methods using the program SIR92. Least-squares refinement against F was carried out on all non-hydrogen atoms using the program CRYSTALS. Sheldrick weights were used to complete the refinement. Plots were produced using ORTEP III for Windows.
Results
Powder X-Ray Diffraction: The most intense peaks in the X-ray diffractogram were located at 2θ=7.1°(±0.1°) and 21.4°(±0.1°). The X-Ray diffractogram is shown in FIG. 1 .
FT-Raman Spectroscopy: Characteristic signals in the Raman spectrum of polymorph B were found at 3107 cm −1 (most intense peak in the C-H region), 1605 cm −1 , 1593 cm −1 , 1538 cm −1 , 1336 cm −1 , and 102 cm −1 . The FT-Raman spectrum is shown in FIG. 2 .
Differential Scanning Calorimetry: The DSC measurement showed a sharp melting peak at approximately 158° C. with a melting enthalpy Δ fus H=104 J/g. The DSC curve is shown in FIG. 3 .
Single crystal structure: The compound crystallized in the centro-symmetric space group P-1. The structure showed two molecules in the asymmetric unit which were not related by space group symmetry. These two molecules could be superimposed almost perfectly by rotation around the a axis, but the unit cell could not be transformed in order to gain higher lattice symmetry.
The structure could be interpreted as being based on dimers of the compound. The driving force for the formation of these dimers was most likely π-π interaction between the phenyl ring and the thiophene ring on the one hand and the N-heterocycles on the other hand. The two different types of molecules in the unit cell formed two different types of dimers with slightly different short distances between the condensed N-heterocycles (3.348 Å and 3.308 Å for the shortest distance, respectively). The dimers were arranged in layers with a fishbone structure. Bands of the two types of dimers always alternated in the fishbone structure, as well as they alternated from one layer to the next. The crystal data are reported in Table 1.
TABLE 1
Crystal data for polymorph B
Molecular formula
C 20 H 15 FN 4 O 2 S
Molecular weight
394.43 g/mol
Molecules per unit cell Z
4
Calculated density
1.478 g/cm 3
Number of electrons per unit cell F(000)
816
Size of crystal
0.14 × 0.18 × 0.24 mm 3
Absorption coefficient
0.218 mm −1
Min./max. transmission
0.96/0.97
Temperature
173° K
Radiation (wavelength)
Mo Kα (α = 0.71073 Å)
Crystal system
triclinic
Space group
P-1
a
8.9236(2) Å
b
14.0292(3) Å
c
15.6218(3) Å
α
65.3449(14)°
β
87.0440(14)°
γ
86.0799(14)°
Volume of the unit cell
1772.69(7) Å 3
Min./max. θ
1.435°/27.883°
Number of collected reflections
16548
Number of independent reflections
8448 (merging r = 0.034)
Number of observed reflections (I > 2.00σ(I))
5430
Number of refined parameters
506
r (observed data)
0.0455
rW (all data)
0.0734
goodness of fit
0.9980
residual electron density
−0.37/0.39 e Å −3
X-Ray diffractogram, FT-Raman spectrum and DSC curve are identical with disclosed in the referred European patent application entitled “Polymorph B of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide” when compared by superposition. Moreover, crystal data are consistent with the reported in said application.
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The present invention relates to a novel process for the industrial manufacture of polymorph B of N-{2-Fluoro-5-[3-(thiophene-2-carbonyl)-pyrazolo[1,5-a]pyrimidin-7-yl]-phenyl}-N-methyl-acetamide.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to punching plural holes in a substrate, such as "greensheet", or a metal foil at a high rate of speed. More particularly, an electrical coil is described that has enhanced cooling features, which increases the speed and reliability of the magnetic repulsion punch apparatus, in which the coil is used.
2. Description of the Related Art
Magnetic repulsion technology has been utilized for several years to punch greensheets in order to form multilayer ceramic substrates for use in the computer industry. Briefly, the repulsive forces generated between an energized electrical coil and an electrically conductive punch head, or disk, is used to drive the punch into a dielectric material, thereby forming holes. These holes or vias are then aligned on adjacently stacked dielectric sheets and metallized to form multilayer substrates. More specifically, several configurations of coils have been utilized in magnetic repulsion punches with varying degrees of success.
For example. U.S. Pat. No. 4,821,614, hereby incorporated by reference, describes a wire wound coil that includes plural configurations of spacers, adjacent to the wire, which allow cooling fluid to be circulated radially through the coil. However, it has been found that the mechanical characteristics of wire wound coils will not meet the requirements of a production type magnetic repulsion (M-R) tool, thereby causing extensive down time. It has been determined that this type of coil has an average life of approximately 15 million cycles. Further it can be seen that by creating spaces between the wound wires, less conductive material can be included in the coil such that electrical performance is degraded.
U.S. Pat. No. 4,872,381, hereby incorporated by reference, uses a coil that is photoetched from a flat copper or aluminum sheet. This coil is made from two separate etched pieces and then assembled. Liquid coolant is circulated through the coil. A problem exists with this design, because there is not a sufficient number of turns to provide the necessary magnetic force, nor is the crossectional area of the conductors sufficient to make the impedance acceptably low.
To solve the problems exhibited by the coils in the previous magnetic repulsion tools, a tape wound coil was developed and is described in IBM Technical Disclosure Bulletin, Vol. 33, No. 4, September 1990, pps. 219-220, hereby incorporated by reference. This coil was cooled by exposing one of the generally planar sides of the coil to a coolant. Although providing adequate electrical characteristics, the tape coil was not able to operate at the necessary high frequency due to lack of a sufficient cooling mechanism.
Additionally U.S. Pat. No. 4,209,129 describes a cooling system for the punch head of a solenoid operated punch apparatus. More particularly, coolant is circulated through a manifold chamber to conduct heat away from a punch assembly.
It would be desirable to have a coil for use in a magnetic repulsion punch apparatus that exhibited all of the electrical characteristics of a tape wound coil, but without the cooling problems associated with these types of coils. Further a method of consistently making coils that exhibit these electrical and cooling characteristics would be advantageous.
SUMMARY OF THE INVENTION
In contrast to the prior art, the present invention is a tape wound coil having a plurality of slits therein which allows circulation of coolant therethrough. Broadly, a coil made of thin copper foil, or the like, is treated with an epoxy, for providing electrical insulation between the windings, and wound around a center post. A planar face of the coil is machined smooth, whereas a counter bore is machined into the back of the coil such that a portion of the center post and the inner most windings are removed. Radial slits are then machined into the back of the coil, which will allow for the coolant flow.
Thus, a coil for use in magnetic repulsion punching is provided which maximizes the capacity for carrying electrical current and increases the winding density currently exhibited by conventional M-R coils. Further, the coil of the present invention will withstand high repetition mechanical shear forces created as a result of the large amount of electrical current pulsing through the windings.
Therefore, in accordance with the previous summary, objects features and advantages of the present invention will become apparent to one skilled in the art from the subsequent description and the appended claims taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a crossectional view of the tape wound coil of the present invention prior to the formation of cooling slits therein;
FIG. 2 is a plan view of the coil of FIG. 1;
FIG. 3 is a plan view of the tape wound coil with cooling slits therein;
FIG. 4 is an elevation view of the coil of FIG. 3;
FIG. 5 is a crossection of a portion of a magnetic repulsion punch with the coil of the present invention disposed therein;
FIG. 6 shows the metal foil used to make the tape coil:
FIG. 7 illustrates how the metal foil is affixed to the center post;
FIG. 8 is a plan view of a winding apparatus used to fabricate the tape wound coil of the present invention;
FIG. 9 is an elevation of the winding apparatus of FIG. 8; and
FIG. 10 shows the metal foil wound around a center post during fabrication of the coil of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 a tape wound coil is shown and generally referred to by reference numeral 1. Conductive foil windings 3 are shown concentrically layered (wound) about a center post 5 (see FIG. 6). Individual metal foil layers 3a may consist of any electrically conductive material but copper foil was used in the preferred embodiment of the present invention and exhibits desirable electrical and mechanical characteristics. Center post 5 includes a cylindrical cavity portion 6 having threaded walls 7. A center terminal post 9 with a threaded end portion 11 can be threadedly engaged with threads 7 of center post 5. A cavity 12 is included within winding 3 such that annular area 13 is formed about the circumference of center terminal 9, when terminal 9 is engaged with center post 5, and will aide in the dissipation of heat generated by coil 3, as described in detail below. A layer 15 of the copper foil 3a utilized by windings 3 is shown unwound from coil 1 and attached to an outer terminal post 17. It will be understood by those skilled in the art that outer terminal post 17 and center terminal post 9 will be connected to a cyclically operated power supply which energizes windings 3 of coil 1 and induces magnetic energy, which is used to drive a punch through a substrate material to form holes therein (FIG. 5).
FIG. 2 is plan view of coil 1 of FIG. 1 and shows concentric windings 3. Further, center terminal post 9 and the annular area 13, as well as outer terminal post 17 and the attached single foil layer 15 are illustrated in FIG. 2. It can be seen that the metal foil 15 can be affixed to outer terminal post 17 by conventional means such as soldering or the like.
FIG. 3 is a plan view of coil 1, similar to previously described FIG. 2. However, FIG. 3 shows cooling slits 19 which are radially disposed coolant passageways, formed into the winding 3 of coil 1. Again, terminal post 9 and 17 are shown, as well as connecting foil layer 15. Additionally, annular area 13 is shown surrounding center terminal post 9 and in communication with slits 19, which extend radially outward from annular area 13 to the circumference of the coil 1. Thus, each layer 3a of winding 3 is intersected by plural cooling slits 19. FIG. 4 is an elevation view of coil 1 showing a lower portion 23 and a plurality of slits 19 formed in a top portion 21. It can be seen that slits 19 cannot be extended across the entire width of coil 1 without degrading mechanical and electrical performance. In the preferred embodiment, coil 1 requires a thickness of approximately 5/8 inches in order to fit into the magnetic punch apparatus. It has been found that a slit 19 with a thickness approximately 1/2 the coil thickness, or in this case 5/16 inches will provide good results. Thus, the thickness of upper portions 21 and lower portion 23 are each approximately 5/16 inches. A planar surface 25 of coil 1, on a side opposite the slits, will be used to interface with a punch head, as described below.
Next, the operation of the tape wound coil of the present invention in a magnetic repulsion punch will be described in conjunction with FIG. 5. FIG. 5 shows a magnetic repulsion punching apparatus which is generally referred to by reference numeral 27. An upper housing 29 is shown which includes cooling channels 30 disposed therein. Housing 29 also includes a first cavity portion defined by a generally cylindrically shaped wall 32 which receives coil 1. Further, a second cavity, defined by wall 34 is included in housing 29. The diameter of the second cavity, defined by wall 34, is equal to the diameter of the annular area 13 of FIG. 1. Thus, as coil 1 is placed into housing 29, a second annular area 36 is defined between center terminal 9 and wall 34 which is in communication with annular area 13.
A punch assembly is shown which includes a punch head 47 that is generally configured as a copper disk, although other suitable electrically conductive materials such as aluminum or the like are contemplated by the present invention. A shaft 39 extends downward from punch head 47. Biasing means 45, such as spring, or the like, biases punch head 47 adjacent surface 25 of lower portion 23 of coil 1. Retaining means 43, such as a washer, or the like, provides a surface that maintains spring 45 in compression between punch head 47 and a lower housing 31 of the magnetic repulsion punch apparatus 27.
Lower housing 31 includes a cavity 41 which allows punch head 47 to move upwardly and downwardly therein. A second cavity 40 is in communication with cavity 41 and allows shaft 39 to extend downwardly from lower housing 31. Guide bushing 42 is provided within cavity 41 and ensures proper vertical alignment of shaft 39 therein. A substrate support 33 is also shown and includes a cavity 50 capable of receiving shaft 39 as it is driven downwardly from lower housing 31. It can be seen that lower portion 33 will support substrate material 35, which is disposed adjacent to lower housing 31, during punch operations. Further, a hole 37 is shown which has been formed in substrate material 35 by punch shaft 39, as it was driven downwardly in response to the energization of coil 1.
In operation, center terminal 9 and outer terminal 17 (not shown) are energized, thereby providing electrical energy to winding 3 of coil 1 which in turn induces magnetic energy due to the winding turns. This magnetic energy is then transferred, as a repulsive force, to disk 47 of the punch assembly, thereby driving shaft 39 downwardly to punch hole 37 in substrate material 35. Additionally, it can be seen that coolant will be circulated through coil 1 in order to dissipate heat which is generated due to the operation of the coil. A liquid coolant, such as water, or the like is introduced into annular areas 36 and 13 in a direction as shown by arrows 49. This coolant is introduced under pressure and forced from annular area 13 through upper portion 21 of coil 1 by way of slits 19 formed therein. In this manner, each individual concentric winding layer 3a is contacted by the liquid coolant flowing therethrough which results in enhanced cooling of the tape wound coil 1. Upon exiting portion 21 of winding 3, coolant flows into channel 30 of upper housing 29 (again as shown by arrows 49) and exits punch apparatus 27, thereby dissipating heat from the coil 1.
It has been found through testing that the original tape wound coil, absent any cooling, was able to operate at punch rates of only 10 cycles per second. However, upon utilization of the cooling slits 19 of the present invention the maximum punch rate was increased from 10 cycles per second to 240 cycles per second. Additionally, a reliability test was conducted on the coil of the present invention at a 100 cycle per second rate. It has been shown through testing that the wire wound coil described by U.S. Pat. No. 4,821,614 was capable of operating for an average life of approximately 15 million cycles. However, coil 1 of the present invention was operated through 350 million cycles with no visible degradation of the coil.
The process utilized to fabricate the tape wound magnetic repulsion coil 1 with cooling of the present invention will now be described with reference to FIGS. 6-10. Several criteria must be met in order to form a coil having suitable characteristics to be used in a magnetic repulsion punch application. First, a conductor is desired that will maximize the capacity for carrying electrical current, i.e. a greater crossectional area of the windings, and include surface treatments between the windings that minimize wasted space thereby increasing winding density. Next, sufficient dielectric insulation must be provided on the conductor surface to prevent electrical shorts from occurring between the winding layers, while at the same time making the insulation thin enough to ensure a maximum number of winding turns. The dielectric must also form a bonding surface so that the entire coil can be laminated. Finally, the coil unit must have high structural integrity in order to withstand the machining operations, that form the slits 19, resist high repetition mechanical sheer forces created as result of electrical current pulsing through the winding 3, and eliminate any possibility of voids between the windings in order to prevent leakage therethrough.
Referring to FIG. 6, center post 5 is shown prior to any machining that subsequently occurs to yield the configuration shown in FIG. 1. A strip of metal foil 60 is shown attached to center post 5. Copper foil which is used for metal foil 60 in the preferred embodiment has been previously treated with an electrodeposit process on both surfaces thereof. The electrodeposit provides a mechanical bonding (roughened) surface for a dielectric material, such as epoxy, which is applied by roll coating, curtain coating, or the like in a thin layer on the metal foil. This dielectric coating must be applied in a thin enough layer to assure high lamination density, but thick enough to provide adequate dielectric strength. The dielectric epoxy must then be cured to ensure good adhesion in the subsequent lamination phase. After the curing of the dielectric, the foil can be cut into strips of the desired processing width as shown by strip 60 of FIG. 6. As previously discussed, the preferred embodiment utilizes coil of approximately 5/8 inches, but for processing purposes the width of strip 60 is chosen to be 1.25, inches because two coils can be formed from a single strip 60.
Next, the foil strip 60 is attached to center post 5 by means such as soldering, welding or the like. It has been determined that a 50/50 percent tin/lead solder provides good results. FIG. 7 shows a side view of center post 5 and metal foil 60 and solder area 62, wherein the actual soldering of strip 60 to post 5 occurs. It should be noted that the joining metallurgy between strip 60 and post 5 should be very thin in order to ensure the maximum number of winding turns for a given coil diameter, i.e. any excess solder, or other chemicals must be removed after attachment of strip 60 to post 5.
Next, foil strip 60 is ready to be wound into a coil. An adhesive must be used to bond the winding layers 3a to one another. In the preferred embodiment an epoxy was chosen as an adhesive due to its high strength, temperature resistance and low viscosity. A plan view of a winding fixture 64 used to fabricate the present invention is shown in FIG. 8. Center post 5 is first placed in an axial support member 66 which rotatingly receives center post 5. The end of foil 60, opposite center post 5 is then attached to a tension spring 72, through a clamp mechanism 70. The clamp and spring assembly is used to hold tension on the completed coil during the time period when it is curing. Spring 72 is attached at the other end to a nonmovable base 74. Initially, clamp 70 with the end of foil 60 therein will be biased toward base 74. A crank handle 68, or the like is then affixed to center post 5 rotated such that foil 60 is wound about post 5. The adhesive is applied onto the metal foil as the coil is being wound. Of course, application of this adhesive any can occur by number of conventional means such as brushing, spraying, or the like. A pan 78 is provided within winding fixture 64 such that excess adhesive is retained therein. It can be seen that once metal foil 60 is completely wound about center post 5, clamp 70 will have be drawn toward support 66 with spring 72 exerting tension onto the coil layers. A stop device 76 is then utilized to prevent crank handle 68 from turning in response to the tension within spring 72. In this manner, spring 72 produces a tension in the newly wound coil such that voids in the bonded winding layers are eliminated and a coil having superior mechanical integrity is produced. FIG. 9 is an elevational view of the winding fixture as shown in FIG. 8 and includes the same features as previously described.
After the coil has been cured, the end of foil 60, not attached to post 5, is unwound to give the desired turn density (which is directly related to coil diameter). Next, the post 5 with foil 60 wound thereabout is cut in the center (along line 80 of FIG. 10), thereby yielding two post and foil assemblies. Wound metal foil 60 is now referred to as winding 3, as previously discussed. Additionally, the portion of post 5 extending out of the coil is removed from the winding 3 by cutting, or the like at points as shown by lines 82 and 84 in FIG. 10.
At this point coil blank 86 is formed which includes winding 3 disposed about center post 5 with the length of post 5 being equal to the thickness of winding 3.
Next, blanks 86 are vacuum and pressure impregnated with a low viscosity dielectric material, e.g., epoxy to ensure that no voids, which may have occurred due to the cutting operations, are present along lines 82 and 84 of FIG. 10. Subsequent to the vacuum and pressure impregnation, the epoxy is then allowed to cure.
Referring to FIG. 1, blank 86 is then counter bored such that cavity 12 is formed and annular area 13 is created when terminal 9 is coaxially disposed within coil 1. The remaining portion of the original post 5 is then tapped to form threads 7 which are used to engage threaded portion 11 of center terminal 9.
Referring to FIGS. 3 and 4, radial cooling slits 19 are then machined into the counter bored and tapped coil 1 by using techniques such as sawing and electrical discharge machining. Cooling slits 19 have been machined using slitting saws with adequate results, however this technique is very difficult due to the large depth to width ratio of slits 19. In a preferred embodiment, the method of the present invention uses electrical discharge machining to form cooling slits 19. This technique is capable of forming slits having a narrow width.
Finally, outer terminal 17 is affixed by soldering, or the like to the outer wrap 15 of the coil 1. This point, coil unit 1 is now completed and can be sealed into a coolant housing of the nagnetic repulsion punch apparatus 27, prior to punching operations.
Although certain preferred embodiments have been shown and described, it should be understood that many changes and modifications may be made therein without departing from the scope of the appended claims.
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A tape wound coil is provided, for use in magnetic repulsion punching, that has a plurality of slits therein which allow circulation of coolant therethrough. This coil is made of thin copper foil, or the like that is treated with an epoxy, for electrical insulation between the windings, and then wound around a center post. The face of the coil is machined smooth, whereas a counter bore is machined into the back of the coil such that a portion of the center post and the inner most windings are removed. Radial slits are then machined into the back of the coil, which will allow for the coolant flow. Thus, a coil for use in magnetic repulsion punching is provided which maximizes the capacity for carrying electrical current and increases the winding density exhibited by conventional M-R coils. Further, the coil of the present invention will withstand high repetition mechanical shear forces created as a result of the large amount of electrical current pulsing through the windings.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
REFERENCE TO SEQUENCE LISTING, A TABLE, OR COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX
[0003] Not Applicable
BACKROUND OF THE INVENTION
[0004] Cast aluminum wheels manufactured for the automotive market and other markets frequently have porosity in the material. This porosity is created during the molding or casting process during manufacture of the wheel. As the aluminum freezes from its liquid or molten state in the mold, the aluminum material contracts. This contraction occurs not only at the surface but throughout the interior of the wheel as well. The contracting interior material can develop openings or holes called porosity while accommodating the geometry constraints and cooling rates governing the shape of the wheel in the mold. This porosity is detrimental to the performance of the wheel and can be large enough to allow air to pass through the wheel. A tire mounted to such a wheel would not be capable of sustaining air pressure as the air would leak out through the porosity of the wheel.
[0005] Such wheels are termed or known as “leakers” in the wheel manufacturing industry. They are undesirable. Efforts are made at wheel manufacturing facilities to test for leakers and remove them from the production line. Such wheels are then recycled generally by melting them back into liquid form and recasting the material into another wheel. Unfortunately, most of the cost to produce the wheel has already been spent by the time the wheel is tested for leaking. So, a wheel which has been determined to be a leaker and subsequently scraped or melted back down results in a significant loss to the manufacturer. High scrap rates due to leakers can have a dramatic impact on the cost of manufacturing cast aluminum wheels. Manufacturers go to great lengths to design and build molds and control freezing rates to reduce porosity as much as possible. Even with these efforts, porosity cannot be completely eliminated. As a result, some leakers will always remain.
[0006] The object of the current invention is to provide a method of repair for cast aluminum wheels that leak air due to porosity. This would allow leaking wheels to be reclaimed and not scrapped or melted back down.
BRIEF SUMMARY OF THE INVENTION
[0007] The invention involves repairing cast aluminum wheels that leak air due to porosity. A roller burnishing tool is used to deep roll the surface of the wheel such that the porosity becomes sealed and the wheel no longer leaks air. The wheel can be used in service and does not have to be discarded. By roller burnishing the surface of the wheel under controlled operating parameters, the plastic deformation of the surface and subsurface layers cause the material to flow and the porosity formed during the casting process to close. This effectively seals the wheel's surface permanently for the life of the wheel.
BRIEF DESCRIBTION OF THE DRAWING
[0008] FIG. 1 is drawing showing the cross section of a typical wheel with a burnishing tool shown against the outer surface.
DETAILED DESCRIPTION OF THE INVENTION
[0009] The invention involves using a roller burnishing tool to deep roll the surface of a cast aluminum wheel such that the porosity becomes sealed and the wheel no longer leaks air. Deep rolling is a method of roller burnishing where the parameters of the burnishing process are tightly controlled. Particularly, the parameters of applied force, feed rate, roller material properties, and roller geometry are required to be specified and validated. Unfortunately, past commercially available burnishing tools were not capable of maintaining tight control of the operational parameters to the degree necessary. Deep rolling produces cold work and plastic deformation in the surface of the wheel due to the Hertzian contact stress induced by the action of the roller under an applied load. This plastic deformation effectively closes the porosity in the near surface layers in the wheel material. The residual compressive stresses and cold work induced by the deep rolling process also acts to keep the porosity sealed for the life of the wheel.
[0010] Referring to FIG. 1 , the wheel 1 is shown in cross-section along with the rotational centerline 8 of the wheel. The spherical burnishing member 3 is brought into contact with the surface of the wheel 2 . The spherical burnishing member 3 is retained in housing 4 which also forms the hydrostatic bearing which is further described in U.S. Pat. No. 4,947,668. The piston 10 forces the burnishing member 3 against the surface 2 by a controlled amount of force which is directly proportional to the applied pressure supplied to the burnishing tool. This controlled applied force plastically deforms the surface and subsurface material and closes porosity. The piston housing 6 is mechanically connected to a machine tool shank 9 . The machine tool shank 9 is manufactured such that it will mount into the appropriate machine tool which will be used to perform the burnishing operation. The machine tool could be a lathe, milling machine, or a machining center. The wheel 1 is rotated about centerline 8 during the burnishing process as the spherical burnishing member 3 is feed at a controlled rate in an axial direction along the surface 2 while under controlled load applied by the piston 10 and the supplied fluid pressure. It has also been found that the applied load supplied by piston 10 to the burnishing member 3 must be done gradually at the start of the burnishing area and relieved slowly at the end of the burnishing area in order to create a smooth transition in the residual stress state and amount of cold work induced. In this manner, the entire outside diameter 2 and the bead seat area 5 are deep roller burnished. The inside diameter wheel surface 7 can also be deep roller burnished in the same manner as the outside wheel surface 2 . In fact, it is possible to deep roller burnish the entire surface of the wheel 1 or any part of the surface which is desired.
[0011] The operational deep roller burnishing parameters of applied force, axial feed rate, the size and geometry of the burnishing member 3 , and surface speed are determined experimentally to yield the best results for a particular wheel 1 and amount of porosity. Once determined, these operational parameters must be tightly controlled to ensure reproducibility and repeatability during manufacturing repair processing. The tool shown in FIG. 1 which is described in further detail in U.S. Pat. No. 4,947,668 is capable of operating under such controlled parameters. Other types of burnishing members such as asymmetrical rollers could also be used to generate similar results.
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The present invention is a novel method for the repair of cast aluminum wheels that leak air due to porosity caused during the casting process. It involves deep roller burnishing the surface of the wheel under controlled operating parameters to effectively seal the porosity so that the wheel no longer leaks air.
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TECHNICAL FIELD
[0001] The present invention relates to a curved pleated product having a curved pleat and a method for manufacturing the curved pleated product.
BACKGROUND ART
[0002] There are garments such as a skirt, a one-piece dress, a blouse, and slacks or fabric products such as curtains known in the art that have a gather called a pleat. The pleat is one of popular decoration because of its beautiful impression due to the shade or its wearing comfort due to the looseness in size.
[0003] Methods for forming a pleat in a product such as a garment that have been proposed so far include those of folding a cloth fabric like paper folding to form a wrinkle and sewing a folded over fabric.
[0004] For example, Japanese Patent No. 2504931 proposes a processing method for forming a pleat in which a semi-finished product after sewing is subjected to a pleating machine to be machine-pleated, the semi-finished product is then wrapped by a soft sheet having excellent breathability and heat-resistance, the soft sheet is twisted and bound up with string, and the semi-finished product is put into heat treatment equipment (Patent Literature 1 ). This processing method enables a variety of designs and easily provides high value added pleated products.
CITATION LIST
Patent Literature
[0000]
Patent Literature 1: Japanese Patent No. 2504931
SUMMARY OF INVENTION
Technical Problem
[0006] Most pleats applied to conventional pleated products have linearly formed gathers and lack variation. On the other hand, a wrinkled pleat called a twist pleat can be formed by using the invention described in Patent Literature 1. The twist pleat, however, is formed by wrapping a semi-finished product that is machine-pleated or hand-pleated with a soft sheet, twisting the soft sheet, bound it up with string, and heat-treating the semi-finished product, so that the method provides the entire pleated product with wrinkled and disordered pleat. Such a pleat undesirably impairs a sense of luxury of the product, and also, is not an orderly pleat with neatness, elegance, nor gracefulness. In particular, the invention of Patent Literature 1 cannot manufacture, for example, a loosely waving curved pleat nor a tidily-aligned curved pleat.
[0007] In addition, the conventional pleated products are each formed from a single fabric, and thus, cannot have gathers each of which differs from the other in color, pattern, nor material. Accordingly, the conventional pleated products can only give a beautiful impression due to the shade, and are undesirably limited to monotonous designs.
[0008] The present invention has been made to solve such problems, and aims to provide a curved pleated product that has dramatically improved flexibility of pleat design and thus can be rolled out in a wide variety of variations and that can have new value, like clothing provided with a pleat that gives a graceful or sensual impression, and also aims to provide a method for manufacturing the curved pleated product.
Solution to Problem
[0009] A curved pleated product according to the present invention has a curved pleat including a plurality of fabric pieces with longitudinally curved opposite side edge portions, the fabric pieces including a plurality of outer pleat pieces and a plurality of inner pleat pieces formed narrower than the outer pleat pieces, the curved pleat being formed by alternately arranging the outer pleat pieces and the inner pleat pieces, joining each adjacent fabric pieces along contours of opposing side edge portions, and alternately forming a mountain fold and a valley fold along the contours.
[0010] In an aspect of the present invention, the fabric pieces may include different colors, different patterns, different materials, or combinations thereof.
[0011] A method for manufacturing a curved pleated product according to the present invention includes cutting a plurality of outer pleat pieces and a plurality of inner pleat pieces out of a desired fabric, the outer pleat pieces each having longitudinally curved opposite side edge portions, the inner pleat pieces each having side edge portions that conform with the shapes of the side edge portions of the outer pleat pieces and being formed narrower than the outer pleat pieces, forming a curved pleat by alternately arranging the outer pleat pieces and the inner pleat pieces, joining each opposing side edge portions along contours of the opposing side edge portions, and alternately forming a mountain fold and a valley fold along the contour of each side edge portion, and attaching the curved pleat to a desired position of the product to manufacture the curved pleated product.
Advantageous Effects of Invention
[0012] The present invention dramatically enhances flexibility of pleat design to allow the pleat to be rolled out in a wide variety of variations, and can add new value to a pleated product, such as clothing provided with a pleat that gives a graceful or sensual impression.
BRIEF DESCRIPTION OF DRAWINGS
[0013] FIG. 1 is a computer graphic image showing a front view of a curved pleated garment, which is an embodiment of a curved pleated product according to the present invention.
[0014] FIG. 2 is a computer graphic image showing the back of the curved pleated garment of the embodiment.
[0015] FIG. 3 is a front view of a skirt section of the curved pleated garment of the embodiment.
[0016] FIG. 4 shows fabric pieces constituting curved pleat in FIG. 3 .
[0017] FIG. 5 is a rear view of the skirt section of the curved pleated garment of the embodiment.
[0018] FIG. 6 shows fabric pieces constituting curved pleat in FIG. 5 .
[0019] FIG. 7 is a front view of a skirt section of another embodiment of the curved pleated garment.
[0020] FIG. 8 shows fabric pieces constituting curved pleat in FIG. 7 .
[0021] FIG. 9 is a partially enlarged front view of the skirt section of the embodiment where a lower edge is shown by a solid line and the other edges are shown by dashed lines.
[0022] FIG. 10 is a partially enlarged front view of the skirt section of the embodiment shown in FIG. 7 where a lower edge is shown by a solid line and the other edges are shown by dashed lines.
[0023] FIG. 11 is a computer graphic image showing the upper half of the curved pleated garment of the embodiment.
DESCRIPTION OF EMBODIMENTS
[0024] Hereinafter, an embodiment of an invention according to the present invention will be described using the drawings.
[0025] A curved pleated product 1 has a curved pleat structure, and is a garment such as a skirt, a one-piece dress, a blouse, a party dress, or slacks or a product such as curtains that is decorated with a curved pleat 2 .
[0026] In the embodiment, a curved pleated garment 1 will be taken as an example curved pleated product 1 , as shown in FIGS. 1 and 2 . The curved pleated garment 1 is provided with curved pleats 2 at a front of a skirt section 11 , and also, at a back of the skirt section 11 , a chest section 12 , and right and left sleeve sections 13 . The configuration of the curved pleat 2 will be described mainly based on the curved pleat 2 provided at the front of the skirt section 11 .
[0027] As shown in FIGS. 3 and 4 , the curved pleat 2 in the embodiment is formed by joining a plurality of fabric pieces 21 each having longitudinally curved opposite side edge portions, at the right and left opposite side edge portions along the contours of the opposite side edge portions and then folding the fabric along the contours of the joined side edge portions, alternating between mountain folds and valley folds. That is, unlike a method for forming a pleat by making a fold like a wrinkle on a cloth fabric or by sewing a folded over cloth fabric, surfaces constituting the gathers of the curved pleat 2 are formed from fabric pieces 21 each cut into a different shape. These fabric pieces 21 are joined together by sewing, crimping using an adhesive, or other ways, thereby forming the curved pleat 2 .
[0028] The fabric pieces 21 of the curved pleat 2 are made of a cloth fabric of cotton, silk, or other material, which can be used for garments, curtains, or other products, or made of a leather fabric including natural leather or synthetic leather, for example. The fabric is cut into a predetermined shape using a pattern, or the like, to have the opposite side edge portions formed in longitudinal curves, as shown in FIG. 4 . The fabric pieces 21 of the embodiment include outer pleat pieces 22 that appear on the outer side of the curved pleat 2 and inner pleat pieces 23 that stay on the inner side of the curved pleat 2 . The curved pleat 2 is formed by alternately arranging the outer pleat pieces 22 and the inner pleat pieces 23 , and joining each opposing side edge portions, which are formed in the same contour.
[0029] The outer pleat pieces 22 are fabric pieces 21 each having longitudinally curved left side edge portion A and right side edge portion B. The contour of either right or left side edge portion A or B appears on the outer side of the finished garment to give a beautiful impression. In the embodiment, the contour of the left side edge portion A appears on the outer side, as shown in FIGS. 1, 3, and 4 .
[0030] Similarly to the outer pleat pieces 22 , the inner pleat pieces 23 are fabric pieces 21 each having longitudinally curved left side edge portion a and right side edge portion b that respectively conform with the shapes of the side edge portions A and B of each outer pleat piece 22 . In the embodiment, the outer pleat pieces 22 and the inner pleat pieces 23 are formed such that the left side edge portions A of the outer pleat pieces 22 and the left side edge portions a of the inner pleat pieces 23 have the same contour, and also, the right side edge portions B of the outer pleat pieces 22 and the right side edge portions b of the inner pleat pieces 23 have the same contour, as shown in FIG. 4 . In the embodiment, the right side edge portion B of the rightmost outer pleat piece 22 continues to the back side of the skirt section 11 and the outer pleat piece 22 forms the side silhouette of the skirt section 11 . The left side edge portion A of the leftmost outer pleat piece 22 and the right side edge portion B of the rightmost outer pleat piece 22 may be formed in any shape.
[0031] In the embodiment, the inner pleat pieces 23 are formed to be narrower than the outer pleat pieces 22 , as shown in FIG. 4 . In this way, the inner pleat pieces 23 stay on the inner side of the finished curved pleat 2 , and also, the outer pleat pieces 22 and the inner pleat pieces 23 are arranged such that the contours of the left side edge portions A and the left side edge portions a are aligned laterally parallel to each other, as shown in FIGS. 1 and 3 . The inner pleat pieces 23 may be set to any width, and do not have to be narrower than the outer pleat pieces 22 and may be formed to have almost the same width with the outer pleat pieces 22 .
[0032] In the embodiment, the curve shape appearing on the outer side of the curved pleat 2 in FIG. 3 is defined by the contours of the left side edge portions A and a of the outer pleat pieces 22 and the inner pleat pieces 23 , but the curved shape is not limited to this and may be defined by the contours of the right side edge portions B and b as shown in FIGS. 5 and 6 .
[0033] The width of the inner pleat piece 23 is determined to meet the needs of, for example, how high the curved pleat 2 rises or how softly it flutters. For example, wider inner pleat pieces 23 as shown in FIGS. 3 and 4 make deeper the valleys at the valley folds formed by each inner pleat piece 23 and the outer pleat piece 22 behind the inner pleat piece 23 as shown in FIG. 9 , thereby allowing the gathers to rise higher. On the other hand, narrower inner pleat pieces 23 as shown in FIGS. 7 and 8 make shallower the valleys as shown in FIG. 10 , thereby reducing the height of the rising gathers.
[0034] The fabric pieces 21 may include different colors, different patterns, different materials, or combinations thereof. For example, the color of the inner pleat pieces 23 may be different from that of the outer pleat pieces 22 . In that case, the inner pleat pieces 23 are hidden inside when a wearer is standing still, while they appear when the wearer moves, providing an excellent accent in design. Also, a lace fabric may be used for some of the plurality of outer pleat pieces 22 , achieving a gorgeous or fascinating design.
[0035] The curved pleat 2 is formed by joining the plurality of fabric pieces 21 described above. Now, a description will be made of a method for manufacturing the curved pleated product, including how the fabric pieces 21 are joined together, taking a garment as an example.
[0036] First, the longitudinally curved outer pleat pieces 22 and inner pleat pieces 23 are cut out of a desired fabric. In the embodiment, as shown in FIG. 4 , the plurality of outer pleat pieces 22 and the plurality of inner pleat pieces 23 are cut out of the fabric. The outer pleat pieces 22 are cut out such that they each has longitudinally curved opposite side edge portions A and B. The inner pleat pieces 23 are cut out such that they each has side edge portions a and b that conform with the shapes of the side edge portions A and B of the corresponding outer pleat pieces 22 and such that they are narrower than the outer pleat pieces 22 .
[0037] Next, the outer pleat pieces 22 and the inner pleat pieces 23 having the side edge portions a and b that conform with the side edge portions A and B of the outer pleat pieces 22 are aligned alternately, and each opposing side edge portions are sewed together along their contours. In the embodiment, each right side edge portion B of the outer pleat pieces 22 and the corresponding right side edge portion b of the inner pleat pieces 23 are sewed together along their contours and each left side edge portion A of the outer pleat pieces 22 and the corresponding left side edge portion a of the inner pleat pieces 23 are sewed together along their contours, as shown in FIGS. 3 and 4 . Thus, the fabric pieces 21 are tidily joined together along the contours of the opposite side edge portions.
[0038] The side edge portions A, B, a, and b of the fabric pieces 22 and 23 may be stitched together in any ways as long as they will not frayed, and the stitch type is appropriately selected from, running stitch, reverse stitch, overcast stitch, blind stitch, and other stitches. A core such as wire may be inserted along the contours in order to prevent the pleat from losing its curved contour. The fabric pieces 21 may be joined together by crimping using an adhesive, instead by sewing.
[0039] Next, the joined outer pleat pieces 22 and inner pleat pieces 23 are folded along the contours of the sewed side edge portions A, B, a, and b. Here, the joined fabric is folded to alternate between mountain folds and valley folds. Thus, the outer pleat pieces 22 are arranged on the outer side and the inner pleat pieces 23 are arranged on the inner side as shown in FIG. 1 , thereby forming the curved pleat 2 . In the embodiment, the folded fabric is pressed to put folds at the contours of the side edge portions A, B, a, and b.
[0040] The joined fabric may be folded such that the stitches are hidden on the inner side or appear on the outer side according to the design. The outer pleat pieces 22 and the inner pleat pieces 23 are sewed together and then the joined fabric is folded along the contours in the embodiment, while the fabric may be folded as needed every time an outer pleat piece 22 and an inner pleat piece 23 is sewed together along the contour.
[0041] Finally, the formed curved pleat 2 is sewed on the garment at a desired position to manufacture the curved pleated garment. In this way, the curved pleat 2 can be arranged on a garment freely at a desired position without any design constraints. For example, in the embodiment, a slit is formed at the front center of the skirt section 11 , and the curved pleat 2 is sewed to the right of the slit, as shown in FIG. 1 . Similarly, the curved pleated product 1 of the embodiment has curved pleats 2 sewed thereto at the back of the skirt section 11 , the chest section 12 , and the right and left sleeve sections 13 , as shown in FIGS. 1 and 2 . Thus, the curved pleat 2 can be attached to various portions.
[0042] Now, operation of each configuration in the curved pleated product 1 of the embodiment will be described.
[0043] In the curved pleat 2 , the curved contours of the left side edge portions A of the outer pleat pieces 22 appear in a laterally aligned manner, as shown in FIGS. 1 and 3 . Thus, the curved pleat 2 can give a beautiful impression due to the pleat design with the beautiful curves that cannot be achieved by conventional techniques, to those who look at the curved pleat 2 . Such a curved pleat 2 has high design flexibility, thereby adding various beautiful impressions like a neat impression, a charming impression, or a graceful and sensual impression.
[0044] In addition, the height of the rising each gather of the pleat can be changed by increasing or decreasing the width of the inner pleat pieces 23 as shown in FIGS. 9 and 10 . Accordingly, it is possible to adjust how much the pleat flutters or how high it rises to meet the needs. For example, wider inner pleat pieces 23 as shown in FIG. 9 allow the curved pleat 2 to easily flutter softly and slowly, and thus this tends to emphasize the gracefulness and makes the curved pleat 2 elegant. In contrast, narrower inner pleat pieces 23 as shown in FIG. 10 reduce the weight of the inner pleat pieces 23 to make the curved pleat 2 move easily, and thus the inner pleat pieces 23 tend to appear and disappear whenever the wearer moves.
[0045] The curved contours of the left side edge portions A in the outer pleat pieces 22 appearing on the outer side have a role to define the pleat design and the outer pleat pieces 22 may be designed to have any desired contour. As a result, a manufacturer can easily achieve a desired design image.
[0046] Also, while not shown in the figure, the outer pleat pieces 22 and the inner pleat pieces 23 may include different colors, different patterns, different materials, or combinations thereof, thereby improving the aesthetic effect of the curved pleat 2 . For example, when a see-through material is used for one of the fabric pieces 21 , the effect is that the curved pleat 2 looks as if it was provided with a slit. Alternatively, when a color of the outer pleat pieces 22 is different from that of the inner pleat pieces 23 , the three-dimensionality of the curved pleat 2 is emphasized.
[0047] Further, as shown in FIGS. 1, 2, and 11 , there are only few limits on the position to provide or the size of the curved pleat 2 , which means the curved pleated product 1 itself has high flexibility. For example, the curved pleat 2 may be arranged spirally on a skirt portion of a wedding dress, making the dress gorgeous.
[0048] The above embodiment provides the following effects.
[0000] 1. The shape, color, pattern, material, and the like of each fabric piece 21 may be selected freely, and thus this dramatically enhances the pleat design flexibility, allowing the curved pleat 2 to be rolled out in a wide variety of variations.
2. The arrangement position of the curved pleat 2 can be selected freely, and thus this makes the curved pleated product 1 highly flexible in kind, shape, and the like, allowing the curved pleated product 1 to be rolled out in a wide variety of variations.
3. The curved pleat 2 can add new value to the curved pleated product 1 , including various beautiful impressions like a neat impression, a charming impression, or a graceful and sensual impression, and a sense of luxury.
4. It is possible to appropriately adjust how much each gather of the pleat flutters or how high it rises, by appropriately selecting the width of each fabric piece 21 , and accordingly, the curved pleated product 1 can also be provided with functionality such as ease of mobility.
[0049] The curved pleated product according to the present invention and the method for manufacturing the same is not limited to the above embodiment, and can be changed as appropriate.
[0050] For example, the embodiment has been described taking a dress as an example curved pleated garment, while the curved pleated product 1 is not limited to a garment and can be applied to a variety of products, such as curtains. Also, in addition to the cloth fabric or the leather fabric, fabrics of other materials may be employed.
REFERENCE SIGNS LIST
[0000]
1 Curved pleated product
2 Curved pleat
11 Skirt section
12 Chest section
13 Sleeve section
21 Fabric piece
22 Outer pleat piece
23 Inner pleat piece
A Left side edge portion of outer pleat piece
B Right side edge portion of outer pleat piece
a Left side edge portion of inner pleat piece
b Right side edge portion of inner pleat piece
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[Problem] To provide a curved pleated product and a method for manufacturing curved pleated products, which dramatically increase the degree of freedom in pleat design and are capable of providing pleats of multiple variations and which impart a novel value to products, such as pleated clothing that gives an elegant or “sexy” impression.
[Solution] The curved pleated product has curved pleats ( 2 ) formed by joining together multiple fabric pieces ( 21 ), in which the two side edges (A, B, a, b) are formed as long curves, at the respective left and right side edges (A, B, a, b) along the contours of the two side edges (A, B, a, b) and alternating ridge folds and valley folds along the contours of said joined side edges (A, B, a, b).
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BACKGROUND OF THE INVENTION
This invention relates to a control device for a needle hole switching mechanism in a needle plate in a sewing machine, in which machine the lateral swing amplitude of the needle bar is electrically controlled by an electric driving device for forming stitched patterns, in which machine actuation of the needle hole switching mechanism is regulated by selecting members to change the configuration of the needle hole to conform with the shape required for zigzag stitches or straight stitches in accordance with an operator's requirements, and in which machine the feed dog is caused to drop down under the needle plate to allow manual stitching.
Conventional sewing machines, provided with mechanical pattern generating devices require that when the patterns are changed from zigzag stitches to straight stitches, the lateral swing amplitude of the needle is reduced zero and maintained at that value, and the needle hole is made to conform to straight stitches. In changing the machine pattern from straight stitches to zigzag stitches, these steps are reversed. Such operations are troublesome to the operator of the sewing machine.
SUMMARY OF THE INVENTION
The present invention has been devised to eliminate such faults and disadvantages of the prior art.
It is a first object of the invention to provide automatic control of the needle hole mechanism in the needle plate to correspond to the patterns to be stitched, to thereby simplify machine adjustment.
It is a second object of the invention to provide a needle hole mechanism which does not require independent operation, to thereby prevent needle breakage.
It is a third object of the invention to construct a small structure which will be physically small.
Other features will become apparent from the following explanation of the embodiments of the invention, which explanation refers to the attached drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a sewing machine the invention installed therein;
FIG. 2 shows perspective views of partially dissembled of the invention;
FIG. 3 is a plane view illustrating the relationship between a needle plate and an auxiliary plate thereof;
FIG. 4 is a cross-sectional view along line IV--IV in FIG. 3;
FIG. 5 is a cross-sectional view illustrating the relationship between a lateral amplitude link, a switching plate and an engaging piece;
FIG. 6 shows a partially enlarged view of a disengaging piece;
FIG. 7 shows a block diagram of a control circuit for the invention;
FIG. 8 shows a flow chart used in the control circuit;
FIG. 9 shows successive operation steps in a part of the invention;
FIG. 10 is a perspective view of a portion of a second embodiment the invention;
FIG. 11 shows a perspective view of a block body of the embodiment shown in FIG. 10;
FIG. 12 is a perspective view of a dissembled pulse motor;
FIG. 13 shows a perspective view of a dissembled clutch used in the second embodiment of the invention;
FIG. 14 shows a perspective view of a switching plate of the above;
FIG. 15 shows a cross sectional view of a set clutch solenoid;
FIG. 16 shows a block diagram of a control circuit for the second embodiment of the invention;
FIG. 17 shows a flow chart used in the control circuit of FIG. 16;
FIG. 18 shows a perspective view of a third embodiment of the invention;
FIGS. 19 and 20 show front views of this third embodiment of the invention, illustrating different states thereof;
FIG. 21 shows a cam in detail of the above; and
FIG. 22 shows a block diagram of a control circuit.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
In FIGS. 1-6, reference numeral 1 designates a sewing machine having an arm housing 2 and a bed frame 3. A needle bar supporter 4 is provided, for generating zigzag stitches, and has an upper end which is pivotally secured to arm housing 2 with a pin 5. Side wall 4a of needle bar supporter 4 holds a needle bar 6 vertically for vertical reciprocation, needle bar 6 being fixedly secured at its bottom end to needle 7. A connecting plate 8 is pivotally secured to a meddle part of needle bar supporter 4 by a pin 9, and has piece 8a which faces a left side 4b of needle bar supporter 4 and supports stop screw 11.
A spring 10 is wound on the pin 9. One end of spring 10 engages needle bar supporter 4 and the other end engages connecting plate 8. Stop screw 11 is secured to piece 8a by a nut 12 so that the end of stop screw 11 is always engaged with the left side 4b by means of spring 10, so that needle bar supporter 4 and connecting plate 8 always move together. A rod 13 is pivoted to plate 8 with a pin 14 to enable needle bar supporter 4 to be moved laterally. Stop 15 and 16 are fixed to arm housing 2 for limiting lateral and motion of needle bar 6.
Left stop 15 is disposed at such a position that it touches needle bar 6 when it comes to the leftmost extreme of its lateral range. i.e., the left basic line, and right stop 16 is disposed at such a position that it touches the needle bar 6 when it comes to the rightmost extreme of its lateral range, i.e., the right basic line. A plurality of pattern selectors 17 are arranged within a pattern selecting device shown in FIG. 7.
A block 18 is fixed to arm housing 2, and an electric driver 19 (which, in this embodiment, is a pulse motor) is mounted on the block in to enable lateral motion of needle bar 6 to take place.
A link 20 is secured to a motor shaft 19a of the pulse motor 19, and is also secured to an end of rod 13. When link 20 is rotated by pulse motor 19, needle bar 6 moves laterally via cooperation between rod 13, connecting plate 8 and needle bar supporter 4. Segment 20a is defined at the lower part of the link 20.
Referring now to FIG. 2, it can be seen that switching plate 22 is mounted on a pivot shaft 23, which is secured to block 18. Plate 22 has a hollow cylindrical bushing 22a, and is restrained in axial movement by a flange 23a located at the outermost and of the pivot shaft 23. The switching plate is bent into a U-shape at its upper part to define a bent part 22b, and has a lower erect part 22c.
A coiled tension spring 24 shown in FIG. 1 is arranged between the bent part 22b and block 18, by which spring switching plate 22 rotates clockwise around pivot shaft 23, to be finally restrained by a stop 25 secured to block 18. An engaging piece 26 is mounted on bushing 22a between bent portion 22b and block 18, and is provided with an upper engaging pin 27 which supports a backwardly projecting pin 27a and a forwardly projecting pin 27b. Pin 27a engages a segment 20a in a normal turning range and projecting pin 27b is inserted into a hole 22d formed in the bent part 22b. Therefore, the switching plate 22 and the engaging piece 26 rotate together around pivot shaft 23.
A coiled compression spring 28 is mounted on bushing 22a between switching plate 22 and engaging piece 26. Spring 28 urges pin 27a against segment 20a. In this condition (see FIG. 5), there is created a space "a" between the front of segment 20a and the rear end of engaging piece 26. That is, the length of pin 27a Is equal to a distance of a. Pin 27b is so dimensioned that it extends forwardly from the front end of switching plate 22 by a distance "a 1 ", which is larger than "a". A releasing piece 29 is interposed between block 18 and engaging piece 26, and has at its right end, an oblique portion 29a having a lift "a 2 " larger than "a" as shown in FIG. 6. Its point "p" starts at a rear (lift "h") than an extension line (x--x) of the front part of the oblique portion 29a and its end point "q" terminates at "h+a+h 1 -a 2 " when engagement between the front end of segment 20a and pin 27a ends, at which time the oblique portion 29a is placed at such a position to push engaging piece 26 forwardly by a "a" distance re-engaging segment 20a and pin 27a shown in FIG. 1.
An L-shaped intermediate lever 30 shown in FIG. 1 is pivotally secured at pivot 30a to bed frame 3 and has a punched hole 30b at one end, into which a vertical lever 22c is placed. Intermediate lever 30 is rotated clockwise around pivot 30a by spring 24 via switching plate 22, and this rotation is limited by a stop 31 secured to bed frame 3. A switching lever 32 is pivotally secured at pivot 32a to bed frame 3 and engages intermediate lever 30 at the right end of switch lever 32. Tension spring 33 is stretched between switching lever 32 and bed frame 3 and serves to rotate switching lever 32 counterclockwise around pivot 32. Needle plate 34 is secured to bed frame 3. Auxiliary plate 35 is slidably mounted in a recess 34b formed in an upper surface of needle plate 34 such that the auxiliary plate 35 faces an elongated needle hole 34a in needle plate 34. A pin 36 extending beneath auxiliary plate 35 is inserted into a punched hole 32b at the left side of switching lever 32. A semicircular needle hole 35a is formed forwardly of elongated needle hole 34a, in auxiliary plate 35. An oblong hole 34c is formed in needle plate 34 for moving pin 36, and a collar 37 surrounds pin 36 to prevent auxiliary plate 35 from slipping off switching lever 32. Therefore, when the switching lever 32 is rotated, auxiliary plate 35 slides within recess 34b in needle plate 34.
FIG. 7 shows a block diagram. An output from a pattern selecting device, that is, a signal issued by operation of a pattern selector 17 is routed to an input of a control circuit such as a microcomputer or LSI, and which functionally operates according to the flow chart shown in FIG. 8), and an output of the control circuit is routed to an input of a driving circuit for driving pulse motor 19. The functioning of this first embodiment will be explained with reference to the flow-chart in FIG. 8. The explanation begins with a case in which a pattern selection is made by operating a pattern selector 17, and (CPU) reads out a control signal from (ROM) and a command for a "straight stitch" is issued. To determine whether a new stitch is different from a previous stitch the sewing machine is first rotated at a low speed, and the position of an upper shaft (not shown) can be used to confirm that needle 7 is above needle plate 34 since in order to laterally swing needle 7, it must be above needle plate 34. Pulse motor 19 is then driven by a signal from the control circuit and link 20 is rotated counterclockwise against spring 10 by β° from an original position L in which original position needle bar 6 is located at the left basic line as shown in FIG. 9 (A) and FIG. 9 (B). In this case, needle bar supporter 4 and needle bar 6 do pass by left stop 15, and connecting plate 8 only rotates clockwise around pin 9. When pin 21 comes to position L 1 , engagement between the front end of segment 20a and pin 27a ceases. Pin 27a slides down along the left side of segment 20a and the two are held together by tension spring 24.
When pulse motor 19 rotates in reverse from this state and link 20 rotates clockwise until needle bar 6 reaches the central position of its lateral range, namely, a position M (FIG. 9 (C) (in which needle bar 6 is located at middle basic line), engaging piece 26 engaging the left side of the segment 20a via pin 27a rotates counterclockwise around pivot shaft against the pressure of tension spring 24. Thus auxiliary plate 35 slides towards elongated needle hole 34a via movement of switching plate 22, intermediate lever 30 and switching lever 32, whereby elongated needle hole 34a is covered by auxiliary plate 35 and the shape of the needle hole in needle plate 34 is effectively changed to a semicircular needle hole 35a located in auxiliary plate 35. Thus, needle bar 6 is set to the middle basic line, and needle hole in needle plate 34 is set to correspond with straight stitches. The control circuit then registers the change from zigzag stitching to straight stitching, and the process begins once again.
If the same stitch is again selected, the relationship between position of needle bar 6 and the needle hole in needle plate 34 is the same, since the previous stitch was straight. Pin 21 thus is positioned at point M, and therefore the pulse motor 19 does not change needle position. The sewing machine is then accellerated from low speed operation to high speed operation. As long as straight stitching is selected, the routine will be repeated.
If a different stitch is selected, that is, if the machine is to be reset to zigzag stitching again, it is first confirmed that the sewing machine is operating at low speed and that needle 7 is above needle plate 34. After such confirmation, pulse motor 19 is driven by the signal from the control circuit, and link 20 is rotated in clockwise direction until pin 21 reaches a position R (FIG. 9 (D) in which needle bar 6 is moved to the right basic line. The left end of engaging piece 26 is then pushed forwardly against compression spring 28 by the oblique portion 29a of the releasing piece 29 and is lifted by a distance of "a" and engaging piece 26 moves until pin 27a meets segment 20a. Then, engaging piece 26 is rotated clockwise around the pivot shaft 23 by tension spring 24, and pin 27a can once again engage segment 20a under the influence of compression spring 28 (shown as a hidden line in FIG. 9 (D)). Concurrently, auxiliary plate 35 slides to its original position switching plate 22, intermediate lever 30 and switching lever 32, whereby the needle hole of needle plate 4 is effectively changed to the elongated needle hole 34a. Thus, the needle hole of needle plate 34 is set for zigzag stitching. This change is then registered, and needle bar 6 is returned to its original position. As long as zigzag stitching is selected, the sewing machine is set to operate at high speed, pulse motor 19 is disengaged from the needle hole mechanism and the only needle swinging mechanism is driven.
A second embodiment of the invention will be explained with reference to FIGS. 10-17. Block 38 is secured to an arm frame. Pulse motor 39 (which is fixed to block 38) is one example of an electric driving device for swinging the needle 7. A screen 40 and an amplitude link 41 are fixed to shaft 39a of pulse motor 39, and a pin 42 fixed to amplitude link 41 supports an end of amplitude rod 43. Accordingly, needle swinging is carried out by transmitting a pattern signal from a memory (not shown) to a driving circuit (not shown) for pulse motor 39 to rotate the shaft 39a and thus swing the needle. A recess 41a is formed at a left side of amplitude link 41.
An electromagnetic clutch solenoid 42 is fixed parallel to pulse motor 39 by being attached to furnishing plate 43, which latter is secured to block 38. Numeral 44 designates the plunger of solenoid 42, and numeral 45 identifies a switching shaft for switching a needle hole in needle plate 34. Switching shaft is mounted in a bushing 46 (which is secured to block 38) and has flange 45a at one end. Switching shaft 45 is axially moved together with solenoid plunger 44 because connecting plate 48 is retained in slit 45b (formed opposite flange 45a on switching shaft 45) and in a slit 44a (formed in one end of solenoid plunger 44) by pins 47. Switching shaft 45 is restrained in leftward movement by collar 49 which encircles its right end.
Numeral 50 is a switching arm which extends over block 38 and is mounted on bushing 46, and switching arm 50 is pushed towards flange 45a by a compression spring 51 mounted on bushing 46 between left side wall 50a and block 38. Flange 45a is relieved to a depth "a", measured from the left end of bushing 46. Notch 50b, formed in left side wall 50a of switching arm 50, can engage pin 46a which is provided on bushing 46. Switching pin 52 is located at an extension of left side wall 50a, and the pin 52 can engage recess 41a of amplitude link 41.
A switching plate 53 in the shape of a reversed L is attached to pivot shaft 54, which latter is secured to block 38. An oblong hole 53b formed at an end of a horizontal piece 53a (which is part of plate 53) receives pin 50c, which is located at a center part of left side wall 50a. Tension spring 55 is arranged between horizontal plate 53a and plate 56 which is secured to block 38. Tension spring 55 is arranged between horizontal plate 53a and plate 56 which is secured to block 38. Tension spring 55 serves to rotate switching plate 53 clockwise around pivot shaft 54. A stop 57 is secured to block 38 to limit movement of switching plate 53.
FIG. 16 shows a block diagram of the control system used in this second embodiment. An output from a pattern selecting device, that is, a signal operated by operation of a pattern selector 17 is routed to an input of a control circuit (such as a microcomputer or LSI, and which functionally operates according to the flow chart shown in FIG. 17), and a part of the control circuit functions to control pulse motor 39 to move a control mechanism in synchronism with rotation of an upper shaft of an ordinary sewing machine for swinging the needle bar. Detailed explanation thereof is omitted.
The output of the control circuit is connected to inputs of the pulse motor driving circuit and of the clutch solenoid driving circuit to drive pulse motor 39 and clutch solenoid 42, respectively.
The operation of this second embodiment will refer to the flow chart in FIG. 17. Reference will initially be made to a case where a straight stitch is selected by operating a pattern selector disposed within the pattern selecting device, so that (CPU) reads out a control signal from (ROM) and an order of "Straight Stitch" is issued. To determine whether this straight stitch is different from a previous stitch, i.e. to determine if a previously selected stitch was a zigzag stitch, the sewing machine is first rotated at low speed, after which clutch solenoid 42 is energized. Then, switching arm 50 is moved in a direction shown by arrow P in FIG. 15 via solenoid plunger 44 along switching shaft 45 against compression spring 51. After position of an upper shaft (not shown ) indicates that needle 7 is above needle plate 34 as the necessary prerequisite for needle movement, pulse motor 39 is driven by a signal from the control circuit such that recess 41a of amplitude link 41 is positioned at the leftmost end in its turning range, causing needle bar 6 to move to the rightmost end of the needle range, (that is, the right basic line) via amplitude rod 43. At this position, recess 41a of the amplitude link 41 engages notch pin 52 to rotate amplitude link 41 and switching arm 50. At the same time, the engagement between the engaging pin 46a and notch 50b ceases.
When pulse motor 39 subsequently reverses to position notch 41a of the amplitude link 41 at the center of lateral needle range, needle bar 6 will thus move via amplitude rod 43 to the center basic line. This rotation causes amplitude link 41 and switching arm 50 to rotate slightly clockwise around bushing 46 since the clutch is engaged, and auxiliary plate 35 slides towards elongated needle hole 34a via switching plate 53 intermediate lever 30 and switching lever 32. Therefore, elongated needle hole 34a is covered by auxiliary plate 35 and the shape of the needle hole of needle plate 34 is effectively changed to a semicircular needle hole 35a. Thus, needle bar 6 is set at the middle basic line and the needle hole of needle plate 34 is set to correspond to straight stitching. The control circuit then registers the change from zigzag stitching to straight stitching, and the process begins once again.
If the same stitch is again selected, the relationship between needle position and the needle hole in needle plate 34 is the same, since the previous stitch was straight. Thus, recess 41a of the amplitude link 41 may be retained at the middle of its turning range, and pulse motor 39 therefore does not change needle position. The sewing machine is then accelerated from low speed to the high speed. The clutch solenoid 42 is not needed and it is thus deenergized. In this case, engaging pin 46a of bushing 46 is not located in notch 50b, so switching arm 50 is limited in leftward movement by pin 46a even when clutch solenoid 41 is deenergized. Therefore the amplitude link 41 and the switching arm 50 are still connected to the clutch. Needle bar 6 and needle hole in needle plate 34 are adjusted for straight stitching by keeping amplitude link 41 at its middle position. As long as a straight stitch is selected, the above routine is repeated.
When a zigzag stitch is subsequently selected, it is first confirmed that the sewing machine is operating at low speed and that the needle is above the needle plate (clutch solenoid 42 is already off), after which confirmation pulse motor 39 is driven by the signal from the control unit to rotate the amplitude link 41 such that its recess 41a is positioned at its leftmost extreme. Then, switching arm 50 rotates slightly counterclockwise around bushing 46, and auxiliary plate 35 is moved via switching plate 53, intermediate lever 30 and switching lever 32, to effectively change the shape of the needle hole in needle plate 34 to elongated needle hole 34a. At the same time, switching arm 50 moves toward flange 50b by expansion of compression spring 51. Recess 50b can then engage pin 46a of bushing 46 and the engagement between notch 41a switching pin 52 can then be released, to disengage link 41 and switching arm 50. Thus, the needle hole of needle plate 34 is set for zigzag stitching in elongated needle hole 34a. The change from straight stitching to zigzag stitching is registered, and needle bar 6 is returned to its original position. As long as zigzag stitching is selected the sewing machine is operated at high speed, and pulse motor 39 is separated from the needle hole control mechanism so that only the needle swinging mechanism is driven.
The third embodiment of the invention will be explained with reference to FIGS. 18-22. A body 58 is attached to a sewing machine. A pulse motor 59 is attached to body 58. A bed plate 61 is mounted perpendicular to axis 60 of pulse motor 59, and is convex at regions 61a and 61b (as seen in FIG. 19) so that bed plate 61 is limited in its range of rotation by limiting portion 62 provided on body 58. A screen 63 is fixed to the bed plate 61 for cooperating with a photointerrupter 64 which is fixed to body 58 at a position shown in FIG. 18 or FIG. 19, to thereby generate a signal indicating position of pulse motor 59.
A needle cam 65 is fixed to bed plate 61. As is shown in FIG. 21, cam 65 has an angular region A for controlling needle swing and an angular region B for switching the needle hole. Cam 65 is engaged with engaging pin 67 attached to an L-shaped pivoted lever 66 for controlling lateral swinging of the needle. Lever 66 is pivoted by a screw 68 for moving swinging rod 69 shown in FIG. 19. A spring 70 pulls lever 66 counterclockwise to cause engaging pin 67 to ride on cam face 65. When engaging pin 67 is positioned at location A 1 in FIG. 21, swinging rod 69 swings maximally left, and when engaging pin 67 is positioned at location A 2 swinging rod 69 swings maximally right, so that the needle of the sewing maching is swung maximally left and maximally right, respectively. When the engaging pin 67 is positioned at region B, it serves to keep the needle at a central position. An axle 71 is fixed switching lever 72 and is pivotable on boss 73, so that the needle hole may be switched. The switching lever 72 is urged counterclockwise by a spring (not shown) and is positioned as shown in FIG. 19 by a stop (not shown). Bed plate 61 is provided with a pin 74 for switching the needle hole and when pin 74 strikes switching lever 72 due to counterclockwise rotation of bed plate 61 lever 72 is rotated clockwise. Cam 65 is so arranged that the rotational position of bed plate 61 is within cam region B.
FIG. 20 illustrates that when switching pin 74 rotates switching lever 72 clockwise, pin 67 is located within region B of cam 65 to keep the needle at the middle of its lateral range of motion.
FIG. 20 illustrates that pulse motor 59 rotates almost maximally counterclockwise for forming straight stitches and although the needle plate 34 is not shown, it shows the position in which lever 72 adjusts the needle hole for straight stitching. Here pulse motor 59 is kept stationary for straight stitching. In the position shown in FIG. 19, the needle hole is set for zigzag stitching. The position of screen 63 relative to bed plate 61 is so determined that the resetting position of the pulse motor 59 is located where pin 67 comes to the cam face (A 1 ) of the cam, where the needle swings maximally laterally.
FIG. 22 is a block diagram, in which solid arrows show relations and directions of electric signal, and phantom arrows show mechanical relations. (ROM) is an electric memory for exclusively reading out memorizing a plurality of stitched pattern control signals (including straight stitches) and program control signals. (CPU) is a central processing unit for controlling each of the programs. (RAM) is a read-write memory for temporarily storing processes and results thereof during execution of the programs. I/O is an input and output port. (PS) is a pattern selector which stores in (RAM) results of selecting desired patterns by switches (not shown) provided at the head of the sewing machine. (PG) is a pulse generator for an upper shaft of the sewing machine, which issues pulses in synchronism with rotation of the upper shaft of the sewing machine and gives a pulse signal to (CPU) for reading out a stitching signal from a (ROM). (DV) is an electric driving device for controlling lateral needle swing and fabric feed, and drives pulse motor 59 to control needle swing and pulse motor 59' for controlling fabric feed in accordance with signals from (CPU). Reference numerals 64 and 64' are photo-interrupters generating pulse signals using the screens (of which one is shown at numeral 63 in FIG. 18) which rotate together with their pulse motors 59 annd 59', the signals being sent to (CPU) as resetting signals for pulse motors 59 and 59'.
In this third embodiment, when a control source is turned on, the control circuit in FIG. 22 is energized. When screen 63 is not blocking photo-interrupter 64, pulse motor 59 rotates to be reset to the position shown in FIG. 19. This rotation is carried out after (CPU) confirms that the needle is near its upper dead point by reading the signal of the upper shaft pulse generator (PG). Since the pin 74 for switching the needle hole does not touch switching lever 72 in this position, lever 72 is rotated maximally counterclockwise, and the needle hole (not shown) is therefore elongated for zigzag stitching, and the engaging pin 67 for controlling needle swing is within the region A of cam 65. When a pattern calling for needle swing is selected by operation of the pattern selector (PS), such a pattern can thus be stitched, (CPU) receives a signal from upper shaft pulse generator (PG) and reads out a stitch control signal from memory (ROM) once stitch to cause driving device (DV) to control rotation of pulse motors 59 and 59'. Since cam 65 does not exceed region A driving needle swinging, needle hole switching lever 72 therefore does not rotate, and the needle hole is kept elongated for zigzag stitching without causing the needle to be broken. When the straight stitch is selected by the pattern selector (PS), central processing unit (CPU) uses the program control signal stored in (ROM) and causes pulse motor driving device (DV) to rotate pulse motor (59 in this case) to rotate switching lever 72 clockwise to reduce the needle hole for straight stitching. Then, engaging pin 67 rides in region B of the cam face, and swinging rod 69 keeps with in the center of the needle hole to protect the needle from breakage. The reduction of the needle hole for straight stitching is completed when engaging pin 67 reaches B 1 on cam 65, and this reduction is retained by balancing the pulse motor 59 enabling straight stitching to continue. The switch to straight stitching is accomplished by confirming that the needle is at its upper dead point at the time of resetting. The control of lateral needle swing and the needle hole size has been explained with reference to FIG. 18 followings and in this invention the same structure may be employed for manual stitching by using motor 59' for controlling fabric feed and by sinking the fabric feed control and the feed dog under the needle plate. It is further possible to locate a lever similar to switching lever 72 at another position for providing another function, for example, thread cutting. In such a case, it is necessary to prepare a third region on cam 65 in addition to regions A and B.
According to the present invention, the mechanism of the needle hole in the needle plate is controlled by the electric driving device which is driven by the operation of the pattern selector disposed within the pattern selecting device. Operation is very easy and convenient. Control is carried out when the needle is above the needle plate. The lateral swinging of the needle bar and the switching mechanism of the needle hole of the needle plate are simultaneously by means of the electric driving device for causing lateral movement therefore the needle and needle plate do not interfere with each other at all.
Since the electric driving device is driven at the low speed, the needle hole switching mechanism may be moved for a relatively long period of time. Therefore the load on the electric driving device which actuates the needle hole mechanism is low enough for working, and the inertia load required at high operating speed of the sewing machine may be neglected, the electric driving device is not subject to the total of the inertia load and the working load.
Further, the relation between the electric driving device and the needle dropping hole switching mechanism is governed by the amplitude link mounted on the electric driving device and an engaging piece which is integrally engaged with the amplitude link when it is rotated outside the lateral swinging range. The adjustment of the needle dropping hole is controlled by the switching plate. This control is interrupted by a releasing piece which serves to move the engaging piece axially when rotating the amplitude link to the right basic line of the needle bar. The electric driving device drives the needle bar swing mechanism seperately from the needle hole switching mechanism. Thus, the invention is relatively simple in structure and can be manufactured at a low cost.
The clutch solenoid (which functions as a trigger) does not need to be energized, when the needle hole is adjusted for straight stitching and in this respect energy consumption may be curtailed. Therefore, a small solenoid, not needing a large space and a large control circuit, suffices. In an ordinary mechanism using the solenoid, a relatively large time lag is created between solenoid turnon and its actual movement, and on the other hand a relatively large time lag also exists between solenoid turnoff and actual retraction. Therefore, if the solenoid is used to drive a mechanism which involves a danger of interference between the needle and the needle plate, it is necessary to moniter actual mechanical working with a proper means. However, in the present invention, energization of the solenoid may take place during operation of the pattern selectors and independantly of the phase of the pulse motor, and deenergization thereof can take place when the needle hole switching mechanism is switched to the smaller needle hole, so it is no longer necessary to take the time lag into consideration, thereby avoiding needle breakage.
Furthermore, according to the invention, it is possible to control the mechanism which sinks the feed dog under the needle plate. For example, in controlling the needle hole, when the needle is centrally located, it is not possible to reduce the size needle hole, and therefore even if an erroneous signal is issued, there is no danger of breaking the needle. Further the sewing machine is driven safely without the power source, and the device may be incorporated in the block unit.
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A sewing machine is disclosed in which a needle hole switching mechanism is activated in association with pattern stitch selection.
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[0001] This application claims the benefit of priority under 35 U.S.C. 119(e) to the filing date of Craven, U.S. provisional patent application No. 60/370,832 entitled “Network Interface Unit (NIU) with Integrated Subscriber Interface Module (SIM)”, which was filed Apr. 7, 2002, and is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates to network communication systems. More specifically, the present invention relates to using a subscriber Identity Module (“SIM”) in a network interface unit to allow continuity of services and billing among a plurality of network devices at a plurality of locations.
BACKGROUND
[0003] Subscriber Identity Module (“SIM”) (sometimes referred to as a subscriber interface module) technology, which is known in the art, has been used in mobile phone systems to allow users to establish account information in cellular telephones. For example, if a particular user has a first phone, and then buys another one, a SIM card can be removed from the first phone and inserted into the second one, thereby allowing account authentication, authorization and policy control information, as well as billing information, to be transferred from one phone to the next without the need of canceling the account corresponding to the first phone and then having to establish another account for the second phone. Examples of SIM-stored data include identity and billing information of the consumer, ongoing pre-paid usage totals, account and usage history, allowable access criteria, other information necessary for network usage and consumer favorites.
[0004] In addition to mobile telephone systems, other communication systems associate accounts that correspond to a particular user, in order to facilitate access and billing of the customer. Examples of such services include cable television, wired or wireless telephony, high-speed data and or multimedia services, for which a user typically establishes an account with the provider of each service. The signals for these services, which may be provided by as many different providers as there are services, typically enter into a dwelling or place of business via a customer premises Network Interface Unit (“NIU”). An NIU typically interfaces each of these services to a single dwelling unit (“SDU”) or a multiple dwelling unit (“MDU”), or a single converged services portal may receive signals from a plurality of service providers. Furthermore, these services may all be provided via a single service provider via a single network source such as, for example, xDSL, FTTx, HFC, fixed wireless, etc, in which case the converged services portal would be used.
[0005] Each one of the services may require that a separate account be established corresponding thereto. This requires either speaking with a representative of each service provider separately to establish the account with that a particular provider, or at the least, establish an account online, providing credit card information to the provider so that service level packaging, billing and related procedures can be agreed upon and established. Although this can be burdensome for a homeowner having just moved in to a new residence, many people realize such procedures are a one-time affair, and after the pain is over, tend to forget about the inconvenience. Until if is time to move again; or until they decide to buy a second home, such as a retreat in the mountains or a house on a beach.
[0006] In addition, in today's mobile economy, many people work temporary jobs at locations for durations less than a year, often working at many different locations for a few weeks each during the course of a year. Or, people who have time-share arrangements in resort locations also tend to desire telephone, data and television services. One of the first things one does upon establishing such a new residence is to set up accounts for desired communication services at the new location(s). One can see that after a while, the account establishing process become a real burden. Either they must use the services that are currently established at the particular location, often paying premium rates for limited services, or they must establish their own accounts for such services. In addition, the setup and account activation costs are prohibitive in comparison to the monthly service rates.
[0007] Accordingly, there is a need for a method and system to allow the establishment of authentication, authorization and policy management of one information/services account, and for each of the desired services within the account, such that account subscription and billing information can follow the user, thereby allowing the user to access the subscribed services from a plurality of locations without the need of establishing an account or accounts at each location.
SUMMARY
[0008] It is an object to provide a method and system that allows the transporting and handling of user-account authentication, authorization and policy control information user communications subscription account information from one location to another without the user having to establish a new and different account at each location. A user can establish one or more accounts corresponding to one or more services, and store that account information on a SIM device, such as a card. The card can then be used in one or more NIU devices that may be located at different locations, one being located at a primary residence, one at a secondary residence, another at a temporary job location and yet another at a vacation resort location. Thus, by transferring the card from one NIU to another, the user will have access to all of the subscribed-to services at each of the locations, and will not have to establish new accounts for services at the various locations. By simply removing a device the size of a credit card from one NIU, transporting it to another, and then inserting it into the other NIU, the user can quickly and easily enjoy all of the services for which he or she has subscribed, without having to establish accounts for the same at each location. Furthermore, a single bill, for all the services, or at least a single bill for each one of the services without the need for two or more telephone bills, two or more cable television bills, etc., would greatly reduce the number of bills to keep track of and have to pay each billing cycle, which would probably not be coterminous.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 illustrates a system for facilitating transporting user account information from one location to another to obtain desired services at a plurality of locations using a SIM card.
[0010] FIG. 2 illustrates a system for facilitating transporting user account information from one location to another to obtain desired services at a plurality of locations using a virtual SIM.
[0011] FIG. 3 illustrates a flow diagram of a method for facilitating user account information from one location to another to obtain desired services at a plurality of locations using a SIM.
DETAILED DESCRIPTION
[0012] As a preliminary matter, it will be readily understood by those persons skilled in the art that the present invention is susceptible of broad utility and application. Many methods, embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications, and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the following description thereof without departing from the substance or scope of the present invention.
[0013] Accordingly, while the present invention has been described herein in detail in relation to preferred embodiments, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for the purposes of providing a full and enabling disclosure of the invention. The following disclosure is not intended nor is to be construed to limit the present invention or otherwise to exclude other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.
[0014] Turning now to the figures, FIG. 1 illustrates a system 2 for using a SIM device 4 , such as in the form of a card (it will be appreciated that the other forms may be implemented, including a virtual version where account information is downloaded from a provider's server or determined via personal physical identity, such as, for example, a fingerprint or other biometric means known in the art), for transporting account information related to communication services from one to another among a plurality of NIUs 6 . A user 8 obtains SIM 4 from a variety of means, preferably from a SIM vending machine 10 that dispenses or reprograms a renewable SIM card when requested services are selected and an appropriate amount of money is inserted into the machine, the amount corresponding to the type and level of selected services.
[0015] The SIMs 4 primary function is the handling of the activation, deactivation, maintenance and conditional access of the services and sub-level services supplied via NIU 6 . Information stored in SIM 4 in support of these services can vary with varying degrees of service functionality. For example, SIM 4 can support high-level services, such as telephony, as well as sub-level services such as caller ID. Other examples of services and sub-level services include: telephony/parental control, multimedia/ppv and multimedia/favorites, among others. Examples of data stored on SIM 4 are identity and relative billing information of user 8 , ongoing pre-paid usage totals, account and usage history, allowable access criteria, other network usage information known in the art and consumer/user favorites.
[0016] SIM 4 can be loaded with user-specific information at a location remote from NIU 6 , such as vending machine 10 , or can be loaded with information that facilitates a procedure via the NIU to communicate with external systems (e.g. activation systems) for programming user-specific information. In addition, SIM 4 can provide management of data used by the NIU related to access, credit, system security, etc. (i.e. subscriber authentication and speech encryption keys, etc.) Examples of services facilitated include, but are not limited to, controlled and automated activation, automated deactivation, pre-paid debit processing rental service credit control, parental control applications, encryption, favorite lists and tier-packaging (i.e., class of service). In addition, user 8 can have access to the data stored on SIM 4 via the stroke of a few keys on a telephone keypad or a TV/PC screen, for example.
[0017] When services have been selected and paid for, the vending machine 10 either ejects a new SIM card 4 with authorization for the selected services encoded thereon, or ejects a previously used and inserted card that has been reprogrammed/renewed. A user would preferably have incentive to reuse cards, as the amount of money inserted into the vending machine 10 would be lower than if a new card was programmed and ejected by the machine.
[0018] The vending machine 10 preferably has a user interface, such as a computer monitor, and means for inputting information thereto, such as, for example, a keyboard or the computer monitor that may be designed for touch sensitive data entry, both technologies being known in the art. The user selects the services he desires from a list of services offered by providers the operator of the vending machine 10 has agreements with. and the final cost of the generating or reprogramming is shown before the user selects a button that authorizes the programming charges. These charges may be charges to a credit card that the user enters into machine 10 , or, based on a username and password, the predetermined credit account may be automatically billed, or the user may choose to input cash into the machine. In addition, instead of programming or reprogramming a physical card, the service provider may authorize or reauthorize services based on the amount of money provided to machine 10 , and in response to an identifier, entered by the user, that corresponds to the users device. It will be appreciated that SIM card 4 may have a unique identifier, such as a serial number, that identifies the card, or other SIM device, to the provider's server, rather than having the user input a user name and password, or other identifying information.
[0019] When the programming charges have been authorized and/or paid, the SIM card 4 is programmed and the revised account information is stored to the selected service provider's central location, such as, for example, a head end or a central office. As known in the art, such a central location 12 may contain one or more server computers that store user information in a database 14 . Thus, when a user attempts to access services through NIU 6 , the head end 12 checks information extracted from SIM 4 at the NIU, against the same user's account information stored in database 14 . If the account server at the head end 12 determines that the user is authorized to access the requested services, the services are provided. If the user is determined to not be authorized, programming access to the services is denied, and an error message sent advising the user that the SIM 4 has not been authorized to access the requested services.
[0020] The request for services and the sending of the error message, as well as the providing of the services, is typically transmitted over network 16 . Network 16 may he any of a variety of network types, including, but not limited to, the Internet, a community antennae television coaxial network, an optical fiber network, or a wireless network, any and all of which will be known to those skilled in the art.
[0021] NIU 6 transmits and receives signals and messages from network 16 and interfaces with one or more user interface devices, such as, for example, a computer 18 , a telephone 20 , a television 22 , or a PDA 24 . Communication between NIU 6 and these user devices will typically be provided over local area network (“LAN”) 25 , which may be, for example, an Ethernet network or other LAN type that will be known to those skilled in the art. NIU 6 will typically have a SIM interface device 26 , known in the art, for receiving SIM card 4 and connecting it to the internal circuitry of the NIU, thereby facilitating the transfer of stored information from the SIM card to the NIU. Interlace 26 may allow for external insertion and removal of SIM 4 by a user, or may be internal to NIU 6 so that insertion and removal is performed by the provider.
[0022] Turning now to FIG. 2 , system 27 facilitates the establishing of a virtual SIM in any one or more of NIUs 6 . For example, instead of having a physical SIM device, as shown in FIG. 1 , user 8 inputs service request information to kiosk 28 , including credit card, or other form of payment, account information, including cash inserted into the kiosk device. Upon verification of the user's identity (either the user is an existing customer or registered user in the provider's database 14 , or the user establishes a new account and profile with the provider 12 ), using a username and password, or biometrics, for example, and verification that adequate funds are available, provider 12 downloads a message 30 to one or more of the NIUs 6 . The particular NIUs 6 to which message 30 is sent are NIUs specified by user 8 . If user 8 is an existing customer/subscriber of provider 8 , a list a NIUs 6 associated with the user may appear as a drop down box, list box, or other interface device known in the art. If user 8 is not an existing customer, the user will typically enter identifiers of the NIUs 6 , the NIU identifier being a serial number, for example, that is not on record with the provider 12 , from which requested services are to be established.
[0023] When user 8 attempts to access any of the requested services, such as, for example, a pay-for-view program on television 22 or telephone services on telephone 20 , NIU 6 would check the information carried by message 30 and stored in the NIU to determine if such services are authorized. Thus, a password or other access control methods known in the art are not required. This is advantageous because the access control is provided directly at the NIU 6 , rather than having passwords and other sensitive personal information being transmitted across network 16 . This saves time, server resources at server 12 , and reduces the chance that the sensitive information could be compromised along public network 16 . Furthermore, sensitive information need not even reside on the NIU 6 , because the information carried in message 30 and stored at the NIU is essentially go/no-go (gatekeeping) information corresponding to each of the services requested and authorized by the user. Typically, the only time sensitive information is exposed to network 16 is when user 8 is establishing the services ‘credit’ at kiosk 28 .
[0024] In addition to establishing services credit at kiosk 28 , which may be located in public locations, it will be appreciated that the virtual SIM functionality can be requested and established from any of the user devices connected to LAN 25 A, or any other network that is configured to transmit data to provider 12 . This includes using a personal computer (“PC”) connected to the Internet at any location. Furthermore, user 8 can also speak with a representative on the telephone in person to either establish a new services account or to replenish and/or alter an existing account. It will be appreciated that systems and methods known in the art for providing secure transmitting of information will typically be used. These include, but are not limited to, hash functions, data encryption and secure sockets layer technology, etc.
[0025] Turning now to FIG. 3 , a flow diagram showing the steps in programming a SIM with desired services and levels thereof, as well as the amount of money (which typically is proportional to the length of given subscriptions requested and the levels thereof), is illustrated. The steps shown are applicable to an aspect that uses a physical SIM as well as an aspect that uses virtual SIM functionality.
[0026] After routine 300 starts at step 302 , a user enters a request for services from a service provider at step 304 . This request may be performed at a stand-alone kiosk in a public location, at the provider's place of business, or at a variety of remote locations using a variety interface devices, such as, for example, a PC, a mobile telephone, a landline telephone, or any other fixed or portable device known in the art, with access to a communication network. As part of the request for service, the user will typically be queried for an identifier, such as, for example, a username and password, or a biometric identifier, such as a thumbprint, or other such means known in the art. If the SIM has a unique identifier associated with it, the identifier can be used and no further identification input would be needed from the user.
[0027] At step 306 , the service provider checks the user-provided identifier to determine whether the user has an established account with the provider. This check may he performed manually, such as would be the case if the user had called the provider's representative using a telephone and verbally placed the request with said representative. The check at step 306 may also be performed automatically upon the provider's server receiving the user-provided identifier, or the SIM identifier.
[0028] Upon receiving the user-provided identifier, if the provider determines at step 308 that the user does not have an established account a message is sent to the requesting user at step 310 informing said user that the identification information does not match any user information currently stored in the provider's database. The message may further inform the requestor that he or she may elect to establish an account, upon such election the routine would return to step 304 .
[0029] To establish credit at step 304 , the user will typically provide billing information, such as, for example, a credit card number, name, address, telephone number, etc. In addition, a personal profile, or suite of services, may be established, including the services requested, and the level and location of these services.
[0030] For example, if a household has four televisions, three PCs and five telephones (including two separate numbers), the telephone in a child's room may have restricted access after a certain time of day, all televisions except one may have restricted access to certain channels, and data provided to the PCs may have certain content blocked. Moreover, a user may establish more than one physical location for receiving services. If a user has a primary and a secondary residence, separate profiles may be established for each location, the NIU at each location having functionality to provide a NIU identifier, such as, for example, a serial number. If the primary residence is the household described above, and the secondary residence is a vacation house on a beach, the beach house may only have one television and one telephone and no PC. Thus, each profile may be customized for use with a particular NIU, based on the NIU identifier.
[0031] Another scenario contemplates that at a particular location, multiple users may periodically use the same network devices connected to the same NIU. Such would be the case with a time-share condominium, for example. If the condominium has a different user every week, month or other period of time, each user may have their own SIM, or virtual SIM, associated with their billing account and preferred suite of services. Thus, temporary service does not have to be established for each user before the condominium usage period begins, and cancelled after tire period ends.
[0032] After the provider has determined that the requestor has an established account, the provider determines whether the requestor has sufficient payment capability based on the currently established payment and billing information at step 312 . The established customer with an established account may have credit existing in the services account. This scenario may arise when an existing customer wishes to change the preferences indicated in the one or more profiles associated with that user. If the established user does not have sufficient credit, or if a verification check of a new user's credit card account (or other payment means) indicates that the billing information does not have sufficient credit or the account number or billing address is incorrect, then a message is sent at step 314 to the user informing him or her that either an authorization to charge additional funds must be made, or a different means of payment must be provided.
[0033] If the account has sufficient funds for the requested change in services, the provider performs a financial transaction with the user-provided and authorized financial institution, debiting the user's account at step 316 . When the provider has determined that: sufficient funds have been, or will be, transferred to the provider in connection with the user's request, then the provider downloads a message to the user's SIM means at step 318 . As discussed above, the user's SIM means may be an actual SIM card or other physical device that contains memory and possibly processing means, or SIM card functionality may be implemented in software and/or firmware within an NIU, this functionality being referred to as a ‘virtual SIM.’ The downloading of the message at step 318 will typically be performed over a secure network, as credit having a cash value with respect to a provider will be established in the SIM means at step 320 .
[0034] This credit can then be used at step 322 by an NIU into which the SIM means is inserted, or resides, to grant access to the services requested at step 304 . Alternatively, if the SIM is a virtual SIM, the NIU with respect to which the credit has been requested can grant access to the requested services as long as the credit established at step 322 has not expired or been consumed.
[0035] It will be appreciated by those skilled in the art that the SIM card may also be non-renewable, this type typically being purchased in prepaid cash amounts for predetermined services, such as telephony. While this type of SIM card may not be flexible with respect to the suite of services and the customization thereof, ease of use is provided. For example, in the condominium example described above, the only service having a variable cost, based upon usage level, may be telephony, cable television, for example, being a fixed amount that can be easily calculated into the price of ownership/rental. The same would apply to telephony services in a hotel. Thus, a prepaid card that only authorizes telephony may be desirable.
[0036] These and many other objects and advantages will be readily apparent to one skilled in the art from the foregoing specification when read in conjunction with the appended drawings. It is to be understood that the embodiments herein illustrated are examples only, and that the scope of the invention is to be defined solely by the claims when accorded a full range of equivalents.
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Subscriber-associated authentication, authorization and policy control information is stored on a SIM (preprogrammed or user programmed) to facilitate an NIU at a location granting or denying access to a plurality of services when the programmed SIM or virtual SIM resides in the NIU. A provider stores a message in the SIM based on a payment, which determines the level and period of services to be provided. The SIM can be removed and transported among a plurality of NIUs so that paid-for services follow the SIM.
Each NIU may receive data from a single source and distribute appropriate telephony, data and video services to telephones, computers and televisions, respectively, based on the level and duration of the services requested by a user/subscriber. Thus, services access and billing are user-associated and location-independent. The SIM can be renewable or disposable, and can be programmed before or after purchase by a subscriber.
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BACKGROUND OF THE INVENTION
The present invention relates generally to a torsional vibration damping device, and more particularly, to a torsional vibration damping device for use between an input rotation member and an output rotation member of a power transmission apparatus.
Viscous or fluid dampening devices employed in automotive flywheel devices are known. Such dampening devices are typically disposed between an input flywheel and an output flywheel of a flywheel assembly or power transmission apparatus. Examples of this type of conventional device include a flywheel device used in, for example, the engine of an automobile.
One such prior art device in includes a first flywheel, a second flywheel coupled coaxially to the first flywheel for limited rotary displacement, and a viscous damper mechanism disposed between both the flywheels for elastically connecting the flywheels to each other and dampening torsional vibration between the flywheels by the viscous resistance of viscous fluid in response to rotary displacement between the two flywheels. The viscous dampening mechanism has an annular case fixed to the first flywheel and choke activating members disposed so as to be circumferentially movable within the annular case. The annular case is filled with viscous fluid. The dampening mechanism includes an output member connected to the second flywheel, and has a plurality of projections projected into the annular case. The choke activating members are in a cap shape, and are respectively fitted in the projections of the output member and are movable through a predetermined angle relative to the projections. Chokes through which viscous fluid can pass are formed between the choke activating members and the projections.
In the above described conventional torsional vibration damping device, fluid passes through the chokes formed between the choke activating members and the projections of the output member in response to relative displacement of the first and second flywheels. The chokes limit fluid passage thus dampening vibration during relative displacement of the flywheels. In addition, if respective ends of the choke activating members abut against the projections, the chocks are closed.
In the conventional device, however, there is typically insufficient resistance force to restrain the longitudinal vibration of the body of an automobile during tip-in and tip-out of the automobile and the vibration thereof when starting the engine. The reason for this is that the volume of viscous fluid in the annular case is insufficient, thereby to make it difficult to obtain a sufficient resistance force.
In the above described conventional torsional damping device, a radially outer surface of the output member functions as a part of each chokes. Since the radial outer surface of the output member has a plurality of radial projections, it is difficult to manufacture, machine or process the radially outer surface of the output member with high precision.
SUMMARY OF THE INVENTION
An object of the present invention is to obtain a large damping force which has not been obtained in the conventional construction.
Another object of the present invention is to replenish a fluid chamber with a sufficient amount of viscous fluid to obtain desired viscous resistance.
Still another object of the present invention is to make it easy to manufacture and process an output member.
A torsional vibration damping device according to a first aspect of the present invention is a torsional vibration damping device of a power transmission apparatus having an input rotation member and an output rotation member which is connected to the input rotation member so as to be relatively rotatable and to which power from the input rotation member is transmitted. The torsional vibration damping device includes a viscous damping part and a dry friction part. The viscous damping part is formed between the input rotation member and the output rotation member and includes a choke through which fluid passes in response to relative rotation between the input rotation member and the output rotation member for damping torsional vibration. The dry friction part damps the torsional vibration by dry friction in response to rotary displacement of the input and output members.
The relative displacement between the input rotation member and the output rotation member causes fluid to pass through the choke of the viscous damping part. The choke provides a viscous resistance force to damp the torsional vibration. In addition, the dry friction part produces a dry frictional force.
According to a second aspect of the present invention, a torsional vibration damping device of a power transmission apparatus includes an input rotation member and an output rotation member which are connected to each other to allow for limited rotary displacement therebetween and through which power is transmitted. The limited rotary displacement is defined by two angular displacement ranges, a first range and a second range, the second range being larger that the first range.
The apparatus includes an input member, an output member and a viscous damper mechanism. The input member is connected to the input rotation member, to constitute, together with the input rotation member, an annular fluid chamber filled with viscous fluid. The output rotation member is connected to the output rotation member, and has an abutting part projected into the fluid chamber. The viscous damper mechanism produces a first viscous damping force in the first displacement range, and produces a second viscous damping force in the second displacement range, the second damping force greater than the first damping force. The viscous damper mechanism is provided in the fluid chamber, and has first and second chokes through which fluid passes in response to relative rotation between the input rotation member and the output rotation member and a choke activating member moved in the fluid chamber to open and close the first choke. The choke activating member has an abutting part which abuts against the output member to press one surface of the choke activating member against a wall surface of the fluid chamber in a dry friction state for damping torsional vibration.
If the input rotation member and the output rotation member are relatively rotated in the first displacement range, fluid passes through the first choke to produce the first viscous damping force. If the relative torsional angle is increased, an abutting part of the choke activating member abuts against the abutting part of the output member, to close the first choke. Fluid passes through the second choke in the second displacement range to produce the second viscous damping force.
If the choke activating member abuts against the output member and then, the relative torsional angle is further increased, one surface of the choke activating member is pressed against the wall surface of the fluid chamber by the abutment. A fluid film between the surface of the choke activating member and the wall surface of the fluid chamber is removed by the pressing, whereby both the choke activating member and the fluid chamber slide while being pressed against each other in a dry friction state. Therefore, a large frictional force is obtained.
In this construction, the dry friction state is caused by a part of the choke activating member for opening and closing the first choke. Therefore, it is possible to obtain a large frictional force in a simple structure.
According to a third aspect of the present invention,an input rotation member to which power is inputted is connected to an output rotation member so as to be relatively rotatable therewith and through which the power from the input rotation member is transmitted, a viscous damping part and an annular sealing member are disposed between input and output members.
The above described viscous damping part is formed between the input rotation member and the output rotation member and includes a choke through which fluid passes in response to relative rotation between the input rotation member and the output rotation member and an annular fluid chamber filled with viscous fluid. The annular sealing member is pressed against both the rotation members when pressure is exerted on the fluid chamber, to seal viscous fluid with which the fluid chamber is filled.
If power is inputted to the input rotation member, the power is transmitted to the output rotation member. If the torsional vibration is transmitted to the input rotation member, both the rotation members are relatively rotated, whereby a viscous resistance force is produced by viscous fluid in the annular fluid chamber to damp the torsional vibration. Since the pressure is exerted on the fluid chamber at the time of the relative rotation, the annular sealing member is pressed against both the rotation members. Therefore, it is possible to reduce the leakage of viscous fluid from the annular fluid chamber, thereby to obtain a large resistance force.
A fourth aspect of the present invention includes a torsional vibration damping device of a power transmission apparatus having an input rotation member and an output rotation member which are connected to each other so as to be relatively rotatable and through which power is transmitted. The torsional vibration damping device comprises an input member, an annular output member, and a plurality of slide stoppers. The input member is connected to the input rotation member and together with the input rotation member, forms an annular fluid chamber. The annular output member is connected to the output rotation member, and has its radially outer surface forming a part of the fluid chamber and having a plurality of recesses directed radially inward. The plurality of slide stoppers are disposed so as to be circumferentially movable in the annular fluid chamber and respectively have projections projected into the recesses of the output member to form chokes through which fluid can pass.
If the slide stoppers are moved in the fluid chamber by torsional vibration, the torsional vibration is damped by a resistance force produced when fluid passes through the chokes.
The radially outer portion of the output member need not be provided with projections. Consequently, the radially outer surface of the output member can be subjected to lathe machining, whereby the radially outer surface forms high-precision chokes.
A fifth aspect of the present invention includes a first flywheel and a second flywheel supported on the first flywheel so as to be rotatable, first and second members, an elastic member, and a viscous damping part. The first member is connected to the first flywheel, to ensure a space in which viscous fluid can be contained therebetween. The second member is connected to the second flywheel, to constitute, together with the first flywheel and the first member, a fluid chamber with which viscous fluid is filled. The elastic member elastically connects the first and second members to each other. The viscous damping part moves viscous fluid in the fluid chamber to create viscous resistance in response to relative rotation between the first and second members. The second member has a window hole for containing the elastic member, and has a fluid supplying path connecting with the fluid chamber from the window hole.
If torque is inputted to the first flywheel, the torque is transmitted from the first member to the second member through the elastic member, to further rotate the second flywheel. If torsional vibration is transmitted to radially rotate the first flywheel and the second flywheel, the elastic member repeatedly expands and contracts and the viscous damping part produces viscous resistance, to damp the torsional vibration. At this time, when viscous fluid leaks out of the fluid chamber, the fluid chamber is replenished with viscous fluid through the fluid supplying path from the window hole of the second member. Since the inside of the window hole of the second member is a place where the largest amount of viscous fluid is accumulated, the fluid chamber is replenished with a sufficient amount of viscous fluid, to obtain a desired viscous resistance force.
The foregoing and other objects, aspects and advantages of the present invention will become more apparent from the following detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic cross sectional view showing a power transmission apparatus employing one embodiment of the present invention;
FIG. 2 is a partially enlarged view showing the upper half of FIG. 1;
FIG. 3 is a partially sectional view taken along a line III--III shown in FIG. 2;
FIG. 4 is a partially enlarged view showing the upper half of FIG. 3;
FIG. 5 is a partially enlarged view of FIG. 2;
FIG. 6 is a view similar to FIG. 4, showing relative displacement of various elements of the present invention;
FIG. 7 is a view similar to FIGS. 4 and 6 showing further relative displacement of various elements of the present invention;
FIG. 8 is a view similar to FIGS. 4, 6 and 7 showing still further relative displacement of various elements of the present invention;
FIG. 9 is a graph showing the torsional characteristics of a flywheel assembly;
FIG. 10 is view similar to FIG. 4 showing another embodiment of the present invention; and
FIG. 11 is a view similar to FIG. 2 showing still yet another embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a power transmission apparatus employing one embodiment of the present invention. The left side is the front side (engine side) and the right side is the rear side (transmission side).
The power transmission apparatus is mainly composed of a flywheel assembly 1, a clutch disc 101, and a clutch cover assembly 102.
As shown in FIGS. 1 through 4, the flywheel assembly 1 mainly comprises a first flywheel 2, a second flywheel 3, and a viscous damper mechanism 4 disposed between the first flywheel 2 and the second flywheel 3. The first flywheel 2 is fixed to an end of an engine crankshaft by a bolt 25. The second flywheel 3 has a friction surface 3a against which a friction member of the clutch disc 101 is pressed on its rear side surface. In addition, a clutch cover of the clutch cover assembly 102 is fixed to a radially outer portion of the friction surface 3a.
The first flywheel 2 is a substantially disc-shaped member, and has a hub portion 2a, a disc portion 2b extending outward from the hub portion 2a and formed integrally therewith, and a rim 2c extending backward from a radially outer portion of the disc portion 2b. An annular recess is formed between the hub portion 2a and the rim 2c, and the viscous damper mechanism 4 is contained in the recess. Two rolling bearings 22 and 23 are mounted side-by-side on a radially outer portion of the hub portion 2a. Each of the bearings 22 and 23 is one of a lubricant sealing type having sealing members mounted on both its sides. A snap ring 24 is fitted in a radially outer surface of the hub portion 2a to regulate backward movement of the bearings.
The second flywheel 3 is a substantially disc-shaped member, and its radially inner portion is removably fixed to a driven member 6 (as described below) of the viscous damper mechanism 4 by a bolt 21. In addition, a radially inner end of the second flywheel 3 regulates the backward movement of the rolling bearings 22 and 23. Further, a hole 3b is formed in the radially inner portion of the second flywheel 3 allowing the clutch disc 101 and the viscous damper mechanism 4 to communicate with each other.
The viscous damper mechanism 4, shwon in FIG. 2, is mainly composed of a disc-shaped drive plate 5 fixed to the first flywheel 2, a disc-shaped driven member 6 having its radially inner portion supported on the first flywheel 2 through the rolling bearings 22 and 23, coil springs 12a, 12b and 12c for elastically connecting an input member comprising the first flywheel 2 and the drive plate 5 and the driven member 6 to each other in the circumferential direction, the above members being shown in FIGS. 2 and 3. The viscous damper mechanism 4 further includes a viscous damper part 7 for damping torsional vibration by viscosity of fluid, as indicated in FIG. 2 and described in grerater detail below. The viscous damper mechanism 4, has an annular chamber 7a formed by the first flywheel 2, the drive plate 5, and the driven boss 6a of the driven member 6 is filled with viscous fluid. A radially outer end of the drive plate 5 is fixed to the rim 2c of the first flywheel 2 by a plurality of bolts 19. An annular sealing member 20 is disposed between a radially inner end of the drive plate 5 and the driven boss 6a of the driven member 6. The sealing member 20 and the above described sealing members of the bearings 22 and 23 seal a radially inner end of the above described annular chamber 7a.
Since the drive plate 5 is mounted on the first flywheel 2 by the bolts, the viscous damper mechanism 4 can be replaced by removing the drive plate 5. Consequently, the viscous damper mechanism 4 can be overhauled, thereby making it possible to cope with a large-sized vehicle.
The driven member 6 is a casting member formed in a disc shape, and is disposed between the disc portion 2b of the first flywheel 2 and the drive plate 5. The driven member 6 has the driven boss 6a flanged backward from its radially inner portion, as described above. The rolling bearings 22 and 23 are mounted on a radially inner portion of the driven boss 6a, and the radially inner portion of the second flywheel 3 is fixed to the driven boss 6a by the bolt 21. Six window holes 6b are formed circumferentially equidistant in a radially intermediate portion of the driven member 6. The window holes 6b extend in the direction of rotation, and coil springs 12a, 12b and 12c are contained in the window holes 6b.
As shown in FIG. 3, the coil springs 12c are respectively contained in the radially opposing two window holes 6b (the window holes in the vertical direction of FIG. 3) out of the six window holes 6b of the driven member 6. The coil spring 12c abuts against end surfaces in the circumferential direction of the window hole 6b through spring sheets 13. The large-diameter coil spring 12a and the small-diameter coil spring 12b disposed therein are contained in each of the remaining four window holes 6b.
Although spring sheets 13 are disposed in both ends of the coil springs 12a and 12b, predetermined clearances are respectively ensured between the spring sheets 13 and the end surfaces in the circumferential direction of the window hole 6b in a torsion free state. The spring sheet 13 has a radially outer supporting part 13a and a boss 13b. The large diameter coil spring 12a has its radially outer portion supported on the radially outer supporting parts 13a of the spring sheets 13, and the small diameter coil spring 12b has its radially inner portion supported on the bosses 13b of the spring sheets 13. The coil springs 12a and 12b are prevented from interfering with each other because they are coaxially retained by the spring sheets 13.
The first flywheel 2 and the drive plate 5 respectively have abutting parts which abut against ends of each of the spring sheets 13, whereby the input member comprising the first flywheel 2 and the drive plate 5 and the driven member 6 are elastically connected to each other in the direction of rotation. In FIG. 3, an abutting part 2e of the first flywheel 2 is illustrated.
The viscous damper part 7 is mainly composed of an annular fluid chamber 7a, and a stopper member 8 and a a slider element 10, hereinafter referred to as slide stopper 10 formed of an elastic resin material, which are disposed in the annular fluid chamber 7a.
The annular fluid chamber 7a, described above, is further constructed to be enclosed by a radially inner surface of the rim 2c of the first flywheel 2, a radially outer surface of the driven member 6, and the disc portion 2b of the first flywheel 2 and the drive plate 5. It is filled with viscous fluid. Six stopper member 8 are disposed circumferentially equidistant in the annular fluid chamber 7a, and divide the annular fluid chamber 7a into six division chambers. The stopper member 8 is connected to the first flywheel 2 and the drive plate 5 by pins 9 so as not to be relatively rotatable. A choke C 2 through which viscous fluid can pass between the division chambers is formed between a radially inner surface of the stopper member 8 and the radially outer surface of the driven member 6. Recesses 6c are formed between the window holes 6b on a radially outer edge of the driven member 6; each recess is concave and all are generally circumferentially equidistantly spaced apart from each other. Each recess is formed with inclined surfaces 6e (see FIG. 4) which serve as cam surfaces, as described further below. A liquid supplying hole 6d extending radially outward from the center of the window hole 6b and opening to the annular fluid chamber 7a is formed in the middle between the adjacent recesses 6c. This hole 6d is positioned in the center of the stopper member 8 in a torsion free state.
The slide stopper 10 is formed of resin, and is disposed between adjacent stopper members 8. Within the chamber the stopper members 8 and the slide stoppers 10 further define first arcuate chambers 14 and a second arcuate chambers 15. The slide stopper 10 has its radially outer surface formed in a circular arc shape along the radially outer surface of the rim 2c and has its radially inner surface formed in a circular arc shape along the radially outer surface of the driven member 6. The slide stopper 10 has a projection 10a projected radially inward from its center. The projection 10a is disposed in the recess 6c of the driven member 6 and divides it into a first sub-chamber 16 and a second sub-chamber 17. Each projection 10a is provided with cam surfaces 10b. Further, a choke C 1 through which viscous fluid can pass between the first sub-chamber 16 and the second sub-chamber 17 is formed between a radially inner end of the projection 10a and the bottom surface of the recess 6c.
The choke C 1 is so formed as to have a larger flow passage cross-sectional area than that of the choke C 2 . In addition, the inclined surfaces 6e of the recess 6c and the cam surfaces 10b of the projection 10a of the slide stopper 10 are complimentarily inclined. When any of the surfaces 10b and 6e abut one another, the choke C 1 closes restricting fluid flow. If the cam surfaces 10b and the surfaces 6e are further pressed against one another during relative motion of the flywheels 2 and 3, the slide stopper 10 is urged radially outward due to the inclination of the surfaces 10b and 6e, as described below with respect to the force diagram in FIG. 6.
A radially inner portion of the annular fluid chamber 7a is sealed by annular sealing members 11 formed of Teflon or heat-resistant and wear-resistant resin. The sealing members 11 are respectively disposed between the first flywheel 2 and the driven member 6 and between the drive plate 5 and the driven member 6. As shown in detail in FIG. 5, one of the sealing members 11 is movably disposed between an annular groove 2d formed in the first flywheel 2 and an end surface of the driven member 6. Although the sealing member 11 is disposed in the annular groove 2d, as indicated by a dotted line in FIG. 5, when no pressure is applied to the annular fluid chamber 7a, the sealing member 11 is moved to a position indicated by a solid line in FIG. 5, and when pressure P is applied, the radially inner portion of the annular fluid chamber 7a becomes sealed, the movement of the seal indicated in FIG. 5 by the arrow Z depicted within the seal 11. A similar annular groove is also formed in the drive plate 5, and the other sealing member 11 is disposed inside.
The benefit of the above described construction is that it is not necessary to have radial projections extending from the driven member 6, thus radial outer surface can be processed of the driven member 6 can be processed and the choke C 2 may be formed easily and precisely by lathe. Manufacturing costs are thus reduced, and since the slide stoppers 10 are formed separately, the formations of projections are made easy.
Description is now made of operations of the flywheel assembly according to the above described embodiment.
When torque is input to the first flywheel 2 from the crankshaft on the engine side, the torque is subsequently transmitted to the second flywheel 3 through the driven member 6, the coil springs 12a, 12b and 12c, as well as the viscous damper mechanism 4. At this time, if torsional vibration is inputted from the engine, the coil springs 12a, 12b and 12c repeatedly expand and contract, and the viscous damping part 7 produces a viscous resistance force to damp torsional vibration.
With reference to FIG. 4, description is now made of operations at the time of relative rotation between the first flywheel 2 and the second flywheel 3.
When torque is input to the first flywheel 2 from the crankshaft on the engine side, the first flywheel 2 and the drive plate 5 are rotated relative to the driven member 6. The first flywheel 2 and the drive plate 5 then rotate in the direction of rotation R 1 away from their position in a torsion free state shown in FIG. 4. When the drive plate 5 rotates in the direction of rotation R 1 relative to the driven member 6, the slide stopper 10 is similarly moved in the direction of rotation R 1 . Consequently, the volume of the second sub-chamber 17 is decreased and at the same time, the volume of the first sub-chamber 16 is increased. Specifically, fluid in the second sub-chamber 17 flows to the first sub-chamber 16 through the choke C 1 as the slide stopper 10 is moved. Since the flow passage cross-sectional area of the choke C 1 is large, the viscous resistance thereof is small. In addition, only the coil spring 12c is compressed in a range of small torsional angle, while the coil springs 12a and 12b are not compressed until the spring sheet 13 abuts against the window hole 6b of the driven member 6. Consequently, low rigidity and small viscosity are exerted up to the point where the spring seat 13 abuts against the window hole 6b (i.e. a small torsional displacement angle).
If the torsional displacement angle in the direction of rotation R 1 is increased, the projection 10a of the slide stopper 10 abuts against the end surface of the recess 6c of the driven member 6 (see FIG. 6). Consequently, the choke C 1 is closed and then the choke C 2 functions. The projection 10a is pressed against the end surface of the recess 6c, i.e. cam surface 10b engage surfaces 6e, a force A perpendicular to both abutting inclined surfaces is produced. The force A can be separated into a circumferential component of force B and a radial component of force C. The component of force C and a centrifugal force cause the slide stopper 10 to be pressed radially outward, whereby the radially outer surface of the slide stopper 10 is pressed against the radially inner surface of the rim 2c, and thus eliminating any clearance therebetween. If the first flywheel 2 continues to rotate relative to the slide stopper 10, where the stopper 10 is fixed to the driven member 6, a large resistance force is produced therebetween due to dry friction. The resistance force can be adjusted by manipulation of the complimentary angles of the abutting inclined surfaces 10b and 6e of the projections 10a and the recess 6c.
If the torsional angle shown in FIG. 6 is further increased to that shown in FIG. 7, the coil springs 12a and 12b start to be compressed. In the angular displacement range where springs 12a and 12b are compressed, high rigidity characteristics or responses are obtained. At the same time, fluid in the first arcuate chamber 14 flows into the second arcuate chamber 15 through the choke C 2 . Since the flow passage cross-sectional area of the choke C 2 is small, large viscous resistance is experienced. The above described dry frictional resistance is added to the viscous resistance, thereby obtaining a large resistance force.
Furthermore, the stopper member 8 is moved in the direction of rotation R 1 at this time, whereby the liquid supplying hole 6d of the driven member 6 opens to the second arcuate chamber 15. Therefore fluid, accumulated in the window hole 6b of the driven member 6, quickly flows into the second arcuate chamber 15 by the centrifugal force and an increased attraction force from the second arcuate chamber 15. Since the inside of the window hole 6b is a place where the largest amount of viscous fluid is accumulated in the radially inner portion of the annular fluid chamber 7a, a sufficient amount of fluid can be returned to the annular fluid chamber 7a, thereby making it difficult to cause the shortage of fluid in the annular fluid chamber 7a.
If the torsional angle shown in FIG. 7 is increased to that shown in FIG. 8, the stopper member 8 abuts against the slide stopper 10. Consequently, the relative rotation between the first flywheel 2 and the drive plate 5 and the driven member 6 is constrained.
FIG. 9 is a diagram showing torsional characteristics of the flywheel assembly 1, where a solid line indicates static torsional characteristics, and a dotted line indicates dynamic torsional characteristics. In the static torsional characteristics, a region of small hysteresis torque H 1 which can be seen in a range of small torsional angle is an angle range in which the slide stopper 10 is rotated relative to the driven member 6 so that the choke C 1 functions. Large hysteresis torque H 2 is produced by the choke C 2 . The reason why the small hysteresis torque H 1 in a range of large torsional angle is seen is that when small torsional vibration (for example, combustion fluctuation) is caused in a state where the drive plate 5 is rotated through a predetermined angle relative to the driven member 6, the slide stopper 10 is separated from the end in the circumferential direction of the recess 6c of the driven member 6 so that the choke C 1 functions. Since the small hysteresis torque H 1 can be thus produced irrespective of the relative angle of the drive plate 5 with the driven member 6, it is possible to effectively damp slight vibration at the time of, for example, combustion fluctuation.
In the dynamic torsional characteristics shown in FIG. 9, viscosity becomes significantly larger than the conventional one. The reasons for this are mainly as follows:
⊚ Since a sufficient amount of fluid is returned to the annular fluid chamber 7a from the window hole 6a of the driven member 6, it is difficult to cause the shortage of viscous fluid.
⊚ Since the sealing member 11 seals the annular fluid chamber 7a and the driven member 6 is integrally formed, little fluid leaks.
⊚ A dry frictional force produced by pressing the radially outer surface of the slide stopper 10 against the radially inner surface of the rim 2c is added to the viscosity.
Since a large viscous damping force is exerted on such a large torsional angle, back-and-forth vibration of the body of an automobile at the time of tip-in and tip-out and vibration thereof at the time of starting the engine are restrained.
Description will now made of method of assembly of the above described flywheel assembly 1.
First, the rolling bearings 22 and 23 are forced into the radially inner portion of the driven boss 6a of the driven member 6. The driven member 6 with the bearings 22 and 23 mounted thereon is mounted on the first flywheel 2. At this time, the bearings 22 and 23 are forced into the radially outer portion of the hub portion 2a of the first flywheel 2. The sealing member 11 is previously inserted into the annular groove 2d of the first flywheel 2. After the driven member 6 is mounted on the first flywheel 2, the snap ring 24 is mounted on the hub portion 2a. Further, the spring sheet 13 and the coil springs 12a, 12b and 12c are mounted on the driven member 6. The stopper members 8 are mounted in the annular fluid chamber 7a with the pins 9, and the slide stopper 10 is further inserted into the annular fluid chamber 7a. In this state, fluid (for example, grease) is put in a portion corresponding to the fluid chamber 7a. The drive plate 5, an annular groove of which the sealing member 11 is inserted, is fixed to the rim 2c of the first flywheel 2 by the bolts 19. Subsequently, the sealing member 20 is inserted between the radially inner portion of the drive plate 5 and the radially outer portion of the driven boss 6a.
After the viscous damper mechanism 4 is assembled in the above described manner, the second flywheel 3 is fixed to the driven boss 6a of the driven member 6 using bolts 21.
In such an assembling method, the second flywheel 3 can be easily mounted and removed by removing or tightening the bolt 21. Moreover, in mounting and removing the second flywheel 3, the bearings 22 and 23 and the sealing member 20 need not be touched, thereby decreasing wear on the bearings 22 and 23 and the sealing member 20; thus lengthening their usable lifespan.
In another embodiment of the present invention, the position of the liquid supplying hole is changed, as shown in FIG. 10, thereby it is possible to adjust torsional characteristics. If a fluid supplying hole 51 is shifted in the direction of rotation R 2 , as shown in FIG. 10, the fluid supplying hole 51 openly communicates with the first arcuate chamber 14 at the time point where a slide stopper 10 abuts against a driven member 6 (a state shown in FIG. 6 in the above described embodiment). Consequently, a choke C 2 does not function until the fluid supplying hole 51 is filled with a stopper member 8. The position and the size of a fluid supplying hole and the number of fluid supplying holes are thus changed, thereby to make it possible to adjust the torsional characteristics.
In still another embodiment, an example in which a driven member and a driven boss are separately provided is shown in FIG. 11. In this case, the driven member in the above described embodiment is constituted by three driven plates 66. Wave-shaped inner teeth 66a are formed in a radially inner portion of the driven plate 66, and wave-shaped outer teeth which are engaged with the wave-shaped inner teeth 66a are formed in a radially outer portion of a driven boss 86. The driven plate 66 and the driven boss 86 are thus separated from each other by a serration, whereby the deflection of a second flywheel 3 does not easily affect the driven plate 66. As with the first embodiment, the present embodiment allows for easy removal of the second flywheel 3, improving duration in which the rolling bearings 82 and 83 are usable. The embodiment depicted in FIG. 11 also includes a seal member 80, which is similar to the seal 220 depicted in FIG. 2.
Various details of the invention may be changed without departing from its spirit nor its scope. Furthermore, the foregoing description of the embodiment according to the present invention is provided for the purpose of illustration only, and not for the purpose of limiting of the invention as defined by the appended claims and their equivalents.
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A flywheel assembly comprises a first flywheel, a second flywheel supported on the first flywheel so as to be rotatable, a drive member connected to said first flywheel to ensure a space in which viscous fluid can be contained therebetween, a driven member connected to the second flywheel to constitute, together with the first flywheel and the drive member, a fluid chamber with which viscous fluid is filled, a coil spiring for elastically connecting the members to each other, and a viscous damper part for moving viscous fluid in the fluid chamber in response to relative rotation between both the members to create viscous resistance. The driven member has a window hole containing the coil spring and a fluid supplying path connecting with the fluid chamber from the window hole. The viscous damper part has chokes for creating viscous resistance when the first flywheel and the driven member are relatively rotated. The chokes are opened and closed by sliders which can be pressed against the wall of the fluid chamber in a dry friction state. The driven member has a plurality of recesses concaved radially inward on its outer peripheral surface. The sliders respectively have projections projected into the recesses of the driven member, and the chokes are formed between the recesses and the projections.
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FIELD OF THE INVENTION
[0001] The present invention is directed generally to planar electron beam devices, and more particularly to Metal-Insulator-Metal tunneling planar electron emitters for lithography applications.
BACKGROUND
[0002] Optical lithography has dominated the fabrication of integrated circuits for over 30 years. The general process involves back illuminating a mask with optical radiation, reducing the image of the mask with de-magnifying optics, and then imaging the pattern onto a substrate covered with a layer of photo-resist. Then, with the appropriate photo-resist, the substrate surface (covered with photo-resist) is chemically treated to remove those areas of the photo-resist, which were optically illuminated, thereby transferring a de-magnified image of the mask into the photo-resist. Subsequent chemical etching steps may be utilized to complete the process of transferring a de-magnified image of the mask onto the surface of the substrate material.
[0003] The constant competitive driving force in integrated circuits is for smaller and faster devices. Optical lithography has taken the state of the art down to dimensions where the diffraction of light has become the major limiting variable. Creating features smaller than the wavelength of the illuminating light has led to creative optical techniques such as off-axis illumination and phase-shifting masks. Even so, initially utilizing krypton fluoride excimer lasers at 248 nanometers (nm), and more recently argon fluoride excimer lasers operating at 193 nm, the industry standard today for narrow linewidths utilizing optical lithography hovers somewhere around 80 nanometers, slightly less that 12 the wavelength of the 193 nm illuminating laser. Also, at these short ultraviolet (UV) wavelengths material science issues become a practical limiting factor. For example, there are few materials that have sufficient UV transmission at these wavelengths to be used as either refractive lenses in the de-magnifying relay optics or as substrates for the mask assembly.
[0004] Given this, several non-optical lithography techniques have been explored by the semiconductor industry. Direct write electron-beam (E-beam) lithography has been researched and commercialized given its potential of wavelengths in the nanometer range. Commercial direct-write E-beam devices are readily available today with resolutions down to 50 nm and slightly below, however, the direct write devices are slow to process a large scale wafer and the search continues for a faster way to utilize the potential resolution available from electron-beam lithography.
[0005] Planar electron beam lithography has been investigated for over 20 years with limited commercial success. One configuration commonly referred to as an M-I-M (Metal-Insulator-Metal) planar electron beam lithography (PEBL) device has been constructed and has demonstrated partial technical success. The M-I-M devices consist of an insulator material sandwiched between two conducting metal materials. The individual metal and insulator layers may be made sufficiently thin that when an electrical voltage is applied across the device, electrons from the cathode (the metal with the negative electrical potential) may be driven by the electro-static forces to quantum tunnel into and through the first part of the insulating layer, then drift through the remainder of the insulating layer and anode metal (at the positive potential) and exit the device as free particles, essentially an electron gun. Devices of this type have been fabricated in cross-sectional dimensions as large as 1 inch square, and with appropriate sub-micron masking of the output electron beam, this device configuration opens the possibility of projecting patterns at a 1:1 (one-to-one) ratio in the resist-covered substrate. Also, it has been demonstrated that the exposure time to transfer the entire pattern to the photo-resist in this configuration can be as small as {fraction (1/10)} of a second, which may allow for rapid processing of large commercial wafers utilizing a step-and-repeat procedure. This rapid pattern transfer rate may give the emerging planar electron beam emitter a technical/commercial advantage over the traditional electron beam devices that write the pattern sequentially in the resist similar to how a television raster scans the screen with a small pencil beam.
[0006] However, the useful life of the planar electron emitting devices have historically been sufficiently short so as to limit their applicability to commercially viable manufacturing processes. In view of this, there is a need for a method or technique to prolong the lifetime of planar electron beam emitters for application to electron beam lithography.
SUMMARY OF THE INVENTION
[0007] Generally, the present invention relates to approaches to increasing the lifetime of M-I-M planar electron emitters (PEEs). It is believed that one of the important mechanisms in limiting the lifetime of the PEE is related to the in-diffusion of metal ions from the thin metal anode of the PEE into the insulating layer. Once the metal ions diffuse through the thin insulator to the other metal layer, it becomes impossible to maintain an electric potential between the two metal layers, and so no electron beam can be generated.
[0008] The approaches of the present invention are directed to reducing the possibility that diffusion takes place and also to reversing the diffusion process. Diffusion is a temperature dependent process; for the first approach cooling the PEE to temperatures below room temperature lowers the metal ion mobility, and so the metal ions are less likely to diffuse into the insulator layer.
[0009] In the second approach, the electrical potential across the M-I-M PEE is occasionally reversed from the polarity used to generate the electron beam. This counteracts the electrical driving force that drives the positively charged metal ions from the PEE anode to the PEE cathode, thus increasing the length of time taken for the metal ions to diffuse across the insulator layer from the anode to the cathode.
[0010] In one particular embodiment, the invention is direction to a planar electron emitter system for lithography. The system includes a planar electron emitter having a first electrically conducting layer, a second electrically conducting layer that emits electrons, and an insulating layer disposed between the first and second electrically conducting layers. The second electrically conducting layer emits electrons when held at an electrical potential that is sufficiently positive with respect to an electrical potential applied to the first electrically conducting layer. A source of electric potential is electrically connected to the first and second electrically conducting layers so as to impose an electrical potential across the insulating layer. The source of electric potential is adapted so that a polarity of the electrical potential difference between the first and the second electrically conducting layers is reversible.
[0011] Another embodiment of the invention is directed to a method of exposing a resist on a wafer using a planar electron emitter. The method includes applying a first electrical potential of a first polarity to the planar electron emitter so that the planar electron emitter emits electrons incident on the resist to expose a first portion of the resist. A second electrical potential of a second polarity, opposite to the first polarity, is applied to the planar emitter so that the planar emitter does not emit electrons.
[0012] Another embodiment of the invention is directed to a system for lithography, that includes a planar electron emitter having a first electrically conducting layer, a second electrically conducting layer that emits electrons, and an insulating layer disposed between the first and second electrically conducting layers. The second electrically conducting layer emits electrons when held at an electrical potential that is sufficiently positive with respect to an electrical potential applied to the first electrically conducting layer. A temperature control unit is thermally coupled to the planar electron emitter for controlling temperature of the planar electron emitter.
[0013] Another embodiment of the invention is directed to a method of exposing a resist on a wafer using a planar electron emitter. The method includes applying a first electrical potential of a first polarity to the planar electron emitter so that the planar electron emitter emits electrons incident on the resist to expose a first portion of the resist. The method also includes controlling the temperature of the planar electron emitter at a temperature below an ambient temperature.
[0014] Another embodiment of the invention is directed to a stepper system for lithography, comprising a planar electron emitter that has a first electrically conducting layer, a second electrically conducting layer that emits electrons, and an insulating layer disposed between the first and second electrically conducting layers. The second electrically conducting layer emits electrons when held at an electrical potential that is sufficiently positive with respect to an electrical potential applied to the first electrically conducting layer. The system also includes a temperature control unit thermally connected to the planar electron emitter for controlling the temperature of the planar electron emitter, a substrate mount for holding a substrate having a resist layer facing the planar electron emitter, and an adjustable stage. The mount is fixed relative to the adjustable stage. The adjustable stage is adapted to move a wafer, when the mount holds a wafer, relative to the planar electron emitter so that successively different portions of resist on the wafer are exposed to electrons emitted from the second electrically conducting layer.
[0015] Another embodiment of the invention is directed to a stepper system for lithography that includes a planar electron emitter having a first electrically conducting layer, a second electrically conducting layer that emits electrons, and an insulating layer disposed between the first and second electrically conducting layers. The second electrically conducting layer emits electrons when held at an electrical potential that is sufficiently positive with respect to an electrical potential applied to the first electrically conducting layer. The system also includes a voltage source connected to the first and second electrically conducting layers, the voltage source being adapted to apply a first voltage having a first polarity between the first and second electrically conducting layers, and a second voltage having a second polarity opposite to the first polarity between the first and second electrically conducting layers. There is a substrate mount for holding a substrate having a resist layer facing the planar electron emitter, and an adjustable stage, the mount being fixed relative to the adjustable stage. The adjustable stage is adapted to move a wafer, when the mount holds a wafer, relative to the planar electron emitter so that successively different portions of resist on the wafer are exposed to electrons emitted from the second electrically conducting layer.
[0016] Another embodiment of the present invention is directed to a planar electron emitter system for lithography that comprises a planar electron emitter having a first electrically conducting layer, a second electrically conducting layer that emits electrons; and an insulating layer disposed between the first and second electrically conducting layers. The second electrically conducting layer emits electrons when held at an electrical potential that is sufficiently positive with respect to an electrical potential applied to the first electrically conducting layer. The planar electron emitter has a lifetime in excess of one million exposure shots of approximately 100 msec.
[0017] The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. The figures and the detailed description which follow more particularly exemplify these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:
[0019] [0019]FIG. 1 schematically illustrates an embodiment of a stepper system that uses a planar electron emitter according to principles of the present invention;
[0020] [0020]FIGS. 2A-2C schematically illustrate different embodiments of planar electron emitter;
[0021] [0021]FIGS. 3A-3C present graphs representing different time-dependent electrical potentials applied to a planar electron emitter according to principles of the present invention; and
[0022] [0022]FIG. 4 schematically illustrates an embodiment of a cooled planar electron emitter according to principles of the present invention.
[0023] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
DETAILED DESCRIPTION
[0024] The present invention is applicable to planar electron beam devices and is believed to be particularly useful in Metal-Insulator-Metal (M− 1 -M) tunneling electron emitters for lithography applications. In the process of integrated circuit (IC) manufacturing, the lithographic pattern transfer may be the most critical and frequent process step since up to 30 different patterns may be transferred to the same wafer before the final device can be packaged and tested for quality assurance.
[0025] Planar electron beam lithography (PEBL) has at least two advantages over other next generation lithographic techniques. First, the PEBL technique requires no external ultraviolet, x-ray, or high energy electrons to transfer a pattern from mask to wafer. The electrons needed for pattern transfer are generated within the planar electron emitter (PEE) and the mask is incorporated within the planar electron emitter. And secondly, the entire pattern is transferred simultaneously, whereas competing technologies require “stitching” together a large number of small overlapping patterns. An embodiment of a planar electron beam lithography system 100 is depicted in FIG. 1. The planar electron emitter (PEE) and integrated mask unit 102 is housed in the mask controller device 104 . The mask controller unit 104 may also include a lifetime monitoring device 106 for recording the operational run time and/or number of exposures on the planar electron emitter 102 . The lifetime monitoring device 106 may also include an ammeter, voltmeter, network analyzer or other suitable device and may measure the impedance or other electrical properties of the planar electron emitter 102 . A temperature control unit 108 may be connected to the planar electron emitter (PEE) and integrated mask unit 102 for controlling the temperature of the PEE and integrated mask unit 102 . The temperature control unit 108 may be connected to receive cooling fluid from a fluid source 110 . The cooling fluid source may supply liquid nitrogen, liquid helium, or other suitable liquid to cool the planar electron emitter (PEE) and integrated mask unit 102 .
[0026] The electron beam 112 emanating from the planar electron emitter (PEE) and integrated mask unit 102 may be directed by a projection device 114 to image the mask features at a unity (one-to-one) magnification onto a resist surface of the wafer 116 . The projection device 114 may be a magnetic field, operating in concert with an electric field, oriented in such a way so as to focus the electron beam 112 with an effective magnification factor which is variable, depending upon the strength and orientation of the magnetic and electric field.
[0027] For one particular approach, the projection device 114 includes a pair of Helmholtz coils, wherein the orientation of the magnetic field lines may be perpendicular to the emitting surface of the planar electron emitter (PEE) and integrated mask unit 102 . The projection device 114 may be augmented in the process of “projecting” electrons emitted from the planar electron emitter (PEE) and integrated mask unit 102 by an electric field generated by applying a voltage between the planar electron emitter (PEE) and integrated mask unit 102 and the wafer 116 . The polarity of the voltage between the planar electron emitter (PEE) and integrated mask unit 102 and the wafer 116 may be such that the planar electron emitter (PEE) and integrated mask unit 102 is held at a negative potential in the range of 5 kilo-volts (KV) relative to the wafer 116 . With this polarity, the applied electric field may cause the emitted electrons emanating from the planar electron emitter (PEE) and integrated mask unit 102 to be accelerated in route to the wafer 116 . Also, given the orientation of the magnetic and electric field lines described above, each individual electron's terminal position upon impinging the wafer 116 , is uniquely determined by its location where the electron exits the surface of the planar electron emitter (PEE) and integrated mask unit 102 . In other words, the angle at which an electron exits the planar electron emitter (PEE) and integrated mask unit 102 (relative to the normal to the surface of the PEE) does not affect the effective magnification of the projection device 114 . This is analogous to the classical geometrical optics situation in imaging a point source of radiation to a point source in the image plane. That is, all the radiation emanating from the point source (independent of angle) is focused to a point source in image space, where the location of the image is uniquely determined by the location of the radiating point source. It is in this spirit that the projection device 114 may be referred to as an “imaging device”. Given this, with the appropriate choice of orientations and strengths of the magnetic and electric fields, it is possible to “image” the radiating surface of the planar electron emitter (PEE) and integrated mask unit 102 onto the surface of the wafer 116 with one-to-one (1:1) magnification.
[0028] The wafer 116 may be mounted on a wafer support unit 118 , which in turn may be mounted on an adjustable stage 120 . The adjustable stage 120 may be an X-Y-Z, or X-Y-Z-θ, or X-Y-Z-θ-φ (five degree-of-freedom) adjustable stage which may be driven by a stage controller 121 , which may be part of an overall alignment system 122 . In another approach, the PEE 102 may be adjustable in one or more degrees of freedom to provide movement relative to the wafer. The overall alignment system 122 may be part of a master controller unit 124 , which controls the overall mechanical features of the planar electron beam lithography system 100 . For example, the master controller unit 124 may control the timing and operation of the vacuum system 126 , the alignment system 122 , and the planar electron emitter (PEE) and integrated mask unit 102 .
[0029] An operational sequence of the planar electron beam lithography system 100 may proceed as follows. The master controller unit 124 may generate a command, or receive a command from the interface unit 128 to initiate a deposition run on the wafer 116 . The interface unit 128 may couple to a computer or other suitable device to issue electronic commands to the master controller unit 124 . The master controller unit 124 may in response to an externally generated command, issue a command to the vacuum system 126 to generate a vacuum on the inner chambers of the planar electron beam lithography system 100 to remove potentially contaminating residual gases in the chamber.
[0030] Also, the master controller unit 124 may route a command to the temperature control unit 108 to begin delivering cooling fluid first to the temperature getter device 109 and later to the planar electron emitter (PEE) and integrated mask unit 102 . The getter device 109 may also be held at a lower temperature than the planar electron emitter (PEE) and integrated mask unit 102 to preferentially draw potentially contaminating gaseous particle to the temperature getter device 109 and not to the planar electron emitter (PEE) and integrated mask unit 102 .
[0031] Next, the master controller unit 124 may issue a command to the alignment system 122 and stage controller 120 to orient the wafer 116 in the proper position before initiating electron beam bombardment. The master controller unit 124 may then issue a command to the projection system 114 to set the magnetic and electric field strengths appropriate for the desired one-to-one (1:1) magnification. The command may then be given to apply the necessary voltage signals to the planar electron emitter (PEE) and integrated mask unit 102 to begin electron bombardment on the wafer 116 . The master controller unit 124 may include a timer module to issue repetitive commands to the stage controller 120 to periodically translate the wafer 116 in the horizontal directions X and Y (Z being elevation) in a process commonly referred to in the semiconductor industry as “step and repeat”.
[0032] The above process may be repeated until the wafer 116 has been processed by all the necessary planar electron emitters (PEE) and integrated mask units 102 to achieve the desired structure in the wafer's topology. With the original wafer 116 electron beam lithography completed, the master controller may issue a command to the wafer exchanger unit 132 to remove the original wafer 116 and install the next wafer in the queue to be processed. This procedure may be repeated until all wafers scheduled for electron beam lithography are processed.
[0033] Once the entire top surface of the wafer 116 has been exposed to electron bombardment via the step and repeat process, it may be necessary to insert a different planar electron emitter (PEE) and integrated mask unit 102 in the mask controller unit 104 . The additional planar electron emitter (PEE) and integrated mask unit 102 may be necessary to define additional structures in the wafer's 116 topology. In this event, the master controller 124 may issue a command to the mask exchanger module 130 to remove the original planar electron emitter (PEE) and integrated mask unit 102 and insert the new emitter.
[0034] It will be appreciated that modifications to the above process steps are anticipated. For example, once the entire top surface of the “first” wafer 116 has been exposed to electron bombardment via the step and repeat process, in contrast to the above, the planar electron emitter (PEE) and integrated mask unit 102 may stay in place and an additional wafer similar to the “first” wafer 116 may be inserted by the wafer exchanger unit 132 for electron beam lithography. This process may be repeated until all scheduled wafers have been processed by the “first” planar electron emitter (PEE) and integrated mask unit 102 . Then, if additional planar electron emitters (PEE) and integrated mask units 102 s are needed to fully define the topology of the wafers 116 s , additional planar electron emitters (PEE) and integrated mask units 102 may be inserted one-by-one until all of the scheduled wafers 116 have been appropriately processed by selective electron exposure by the planar electron emitters (PEE) and integrated mask units 102 .
[0035] A cross sectional view of one embodiment of a planar electron emitter (PEE) and integrated mask unit 200 A in the Metal-Insulator-Metal configuration is shown schematically in FIG. 2A. The metal substrate 202 A may be composed of aluminum or other suitable electrically conducting material such as a metal, and serves as the source of electrons for the electron emitter. The conducting substrate 202 A may also be referred to as the cathode of the PEE 200 A, and is typically formed over a structural substrate, for example a silicon or sapphire structural substrate.
[0036] A thin insulating layer 204 A may be formed on the substrate 202 A, for example by over-coating or by chemical treatment. The thin insulating layer 204 A may include aluminum oxide (Al 2 O 3 ) or other suitable insulating material. In the configuration shown in FIG. 2A, a pattern layer 206 A (composed of the resist remaining after a step of chemical etching) has been fabricated on the exposed surface of the insulator layer 204 A by standard lithographic techniques. The pattern layer 206 A has been over-coated with a thin metal overlay 208 A. The thin metal overlay 208 A may be composed of gold or other suitable metal. Typical thickness dimensions for the individual layers may be;
[0037] conducting substrate 202 A thickness: 1 micron
[0038] insulating layer 204 A thickness: 100 Angstroms
[0039] metal overlay 208 A thickness: 100 Angstroms
[0040] It will be appreciated that the thickness of each layer may be greater or less than these typical dimensions. Furthermore, the PEE may be made using different materials. The conducting substrate may be formed from many different types of electrically conducting materials, including metals and conducting semiconductor materials. For the purposes of this description, the first “Metal” in “Metal-Insulator-Metal” is assumed to include electrically conducting semiconductors. For example, the conducting substrate may be formed from electrically conducting silicon, the insulating layer may be formed from silicon dioxide and the thin metal overlay may be aluminum.
[0041] To initiate electron emission from the planar electron emitter (PEE) and integrated mask unit 200 A, an electrical potential (voltage) 210 A is applied between the conducting substrate 202 A (negative lead) and the metal overlay 208 A (positive lead). For the dimensions and materials shown above, a 5-volt potential may be sufficient to commence electron emission. With the applied voltage 210 A, electrons from the surface of the metal substrate 202 A may receive a sufficient driving force to quantum tunnel into and then drift through the remaining thickness of the insulating layer 204 A. Upon exiting the insulating layer 204 A, those electrons that propagate into the resist left behind in the lithographic process to define the mask 206 A are absorbed by the resist material. The remaining electrons that propagate through the insulating layer 204 A and exit in regions where the resist was etched away, continue on, propagating through the metal overlay 208 A and exit the planar electron emitter (PEE) and integrated mask unit 200 A as free-space propagating electrons 216 A. The free space propagating electrons 216 A are subsequently incident on the resist layer on the wafer, so as to selectively expose portions of the resist layer.
[0042] Another embodiment of a planar electron emitter (PEE) and integrated mask unit 200 B in the Metal-Insulator-Metal configuration is shown schematically in FIG. 2B. A conducting substrate 202 B is composed of aluminum or other suitable electrically conducting material and serves as the source of electrons (cathode) for the electron emitter. The conducting substrate 202 B may be over-coated or chemically treated to form a thin insulating layer 204 B, for example made from aluminum oxide (Al 2 O 3 ) or other suitable insulating material. In the configuration shown in FIG. 2B, a mask 200 B may be formed by chemically etching the exposed surface of the insulating layer 204 B prior to overcoating with the metal overlay 208 B.
[0043] In this configuration, the preferential spatial absorption and/or scattering of electrons occurs due to the spatially non-uniform quantum tunneling barrier of the insulating layer 204 B. For example, the insulating layer 204 B, prior to chemical etching, may be deposited or grown in sufficient thickness to absorb and/or scatter electrons that enter the insulating layer 204 B from the metal substrate 202 B. The subsequent chemical etching of the insulating layer 204 B may be carried out until the etched thickness areas are sufficiently thin (similar to the thickness described above in FIG. 2A) such that electrons propagate through the insulating layer 204 B only in those areas “thinned” by chemical etching.
[0044] To initiate electron emission from the planar electron emitter (PEE) and integrated mask unit 200 B, an electrical potential (voltage) 210 B is applied between the metal substrate 202 B (negative lead) and the metal overlay 208 B (positive lead). For the dimensions and materials shown above, a 5 volt potential may be sufficient for electrons to be emitted. With the applied voltage 210 B, electrons from the surface of the metal substrate 202 B may receive a sufficient driving force to quantum tunnel into the insulating layer 204 B with sufficient velocity to propagate the entire thickness of the insulating layer 204 B. And, those electrons transiting the insulating layer 204 B in the “thinned” region 205 B of the insulating layer 204 B, continue on, propagating through the metal overlay 208 B and exit the planar electron emitter (PEE) and integrated mask unit 200 B as free-space propagating electrons 216 B. The electrons 216 B emitted from the metal overlay 208 B are used for illuminating and exposing the resist layer on the substrate.
[0045] Another embodiment of a planar electron emitter (PEE) and integrated mask unit 200 C in the Metal-Insulator-Metal configuration is shown schematically in FIG. 2C. A conducting substrate 202 C may be composed of aluminum or other suitable electrically conducting material and serves as the source of electrons for the electron emitter. The substrate 202 C may be over-coated or chemically treated with a thin insulating layer 204 C which may be aluminum oxide (Al 2 O 3 ) or other suitable insulating material such as silicon dioxide. The surface of the insulating layer 204 C may be over-coated with metal overlay 208 C. In the configuration shown in FIG. 2C, a mask unit 200 C may be formed by at least two different methods. A voltage may be applied between the conducting substrate 202 C and the metal overlay 208 C using a power supply 210 C of some sort.
[0046] In the first method of fabricating the mask unit 200 C, the metal overlay 208 C, prior to chemical etching, may be deposited or grown in sufficient thickness to absorb and/or scatter all electrons which may be entering the metal overlay 208 C from the insulating layer 204 C. The subsequent chemical etching of the metal overlay 208 C may be carried out until the etched thickness areas are sufficiently thin (similar to the thickness described above in FIG. 2A) such that electrons may propagate through the metal overlay 208 C only in those areas “thinned” by chemical etching.
[0047] In a second method of fabricating the mask unit 200 C requires no direct chemical etching of the exposed metal overlay 208 C surface. Instead, a layer of resist may be applied to the exposed surface of the metal overlay 208 C, and the desired mask unit 200 C structure may be fabricated in the resist by standard lithographic techniques.
[0048] In a third method of fabricating the mask unit 200 C, a thin layer of metal overlay 208 C is deposited over the insulating layer 204 C. Regions of the metal overlay 208 C are protected by portions of resist, while other portions of the metal overlay 208 C are exposed. In a second metal overlaying step, additional metal is grown at the exposed regions, so that the thickness of the metal overlay 208 C at those regions protected by the resist remain thin, while those portions 212 C that were exposed during the second metal overlaying step are relatively thick, advantageously too thick to permit passage of electrons that have tunneled through the insulator layer 204 C from the conducting substrate 202 C to have been grown to a greater thickness.
[0049] In a fourth method of fabricating the mask unit 200 C, a thick layer (typically at least 500 to 1000 Ångstroms thick) of metal overlay 208 C is deposited over the insulating layer 204 C. The metal overlay 208 C is then coated with resist material and treated via standard lithographic techniques to define mask geometries similar to those described above in the third method of fabrication. The metal overlay 208 C is then chemically etched in those regions un-protected by resist, down to the insulating layer 204 C. A thin layer of metal overlay is then deposited in the “etched wells” and the resist material may then be chemically removed. Or as an alternative, the resist material may be chemically removed prior to overcoating with a second layer of metal. In this embodiment, the metal overlay 208 C may have two layers of metal in the “thick” region and 1 layer of metal in the “thinned” region. In both cases, electrons propagating through the metal overlay 208 C may be totally absorbed and/or scattered in the thick regions and may propagate through and exit as free particles only in those areas of the metal overlay 208 C that have been sufficiently thinned.
[0050] It is an object of the present invention to increase the useful life of planar electron emitters of the type described above. Experimental PEEs of the type described above have been fabricated, tested, and found to have a limited lifetime both in a pulsed and continuous mode of operation. It is believed that the failure mechanism may involve the in-diffusion of metal atoms from the metal overlay region, the anode, into the insulating region, which contributes to “shorting out” the device, resulting in a catastrophic failure. In response to this, different methods have been developed to increase the useful life of the REE. The methods are designed to modify the mobility characteristics of the in-diffusing metal atoms penetrating into the insulating layer. The first approach comprises periodically reversing the polarity of the voltage applied between the conducting substrate and metal overlay. This can be better understood by referring to the voltage vs. time diagram shown in FIG. 3A. Applied voltage is represented on the vertical axis and time on the horizontal axis. A positive voltage represents a forward bias condition for the planar electron emitter, for example, the negative terminal of a battery or other electrical power source, connected to the conducting substrate, the cathode and the positive terminal connected to the metal overlay, the anode. A certain time period later, the voltage polarity is reversed, and during this period of reverse biasing, it is believed that at least some of the metal ions that have in-diffused into the insulating layer, driven by electric field forces, diffuse in the reverse direction back into the metal overlay region, thereby re-establishing the original Metal-Insulator-Metal (M-I-M) configuration. For the sake of functionally naming the configuration depicted in FIG. 3A, and to identify the differences in the upcoming alternative methods, this configuration is referred to as the “completely symmetric” configuration for the reverse bias approach, in that both the magnitude of the reverse bias voltage and the time interval of the reverse bias are equal to their forward bias counterparts. This procedure has been tested experimentally, and has been shown to increase the useful life of the planar electron emitter by a factor of three-fold.
[0051] Another technique utilizing the “reverse bias” technique is illustrated in the timing diagram shown in FIG. 3B. This configuration is the “asymmetric time interval” approach to applying the reverse bias. Although the magnitudes of the forward and reverse bias voltages are shown to be equal, the time interval for applying the reverse bias is shown to be approximately twice as long as for the forward bias case, although other ratios can be readily applied. Another perspective on this approach may be understood if one thinks of it as the “asymmetric energy” approach. The asymmetric energy approach incorporates the concept of an “engineering safety factor” to increase the probability that metal ions which may have diffused into the insulating layer during the forward bias condition, are driven back into the metal overlay region during the reverse bias time interval.
[0052] Another alternative technique utilizing the “reverse bias” technique is illustrated in the timing diagram shown in FIG. 3C. This configuration is the “asymmetric voltage” approach to applying the reverse bias. Although the magnitudes of the forward and reverse time intervals are shown to be equal, the magnitude of the reverse bias voltage is larger than the forward bias case. In the illustrated embodiment, the positive voltage time was about one half of the reverse voltage time. It will be appreciated that other ratios can be readily applied. Similar to the “asymmetric time interval” approach discussed above, the approach incorporates the concept of an “engineering safety factor” (again, via the asymmetric energy argument) to increase the probability that metal ions which may have diffused into the insulating layer during the forward bias condition, are driven back into the metal overlay region during the reverse bias time interval.
[0053] It will be appreciated that different shapes of waveforms may be applied to the planar electron emitter (PEE) and integrated mask unit 102 . For example, rather than being applied as a square wave, as illustrated, the voltage may be applied with a sinusoidal or triangular waveform, or with some other type of waveform. Furthermore, the asymmetries in time and voltage may be reversed, with the longer times and greater voltages being applied in the forward bias direction.
[0054] It will also be appreciated that the type and magnitude of the reverse bias techniques described above may evolve over time. For example, the information gathered by the lifetime monitor, for example the internal impedance of the planar electron emitter PEE as the PEE ages, may be used to increase the life of the PEE by appropriately altering (e.g., increasing the time duration of reverse biasing or increasing the magnitude of the reverse bias voltage, or both) as the PEE ages.
[0055] The length of time the positive voltage is applied to the PEE depends on the desired duration of the electron beam. For example, under some conditions, a period of 100 msec time may be sufficient to expose the resist on the wafer. Furthermore, it may take a few 100's of msec to step the wafer to the next position. In such a case, the positive voltage may be applied to the PEE for a pulse length of 100 msec, while the negative voltage is applied during the at least a portion of the period that the stepper system needs to align the PEE to the next region on the wafer to be exposed. In other approaches, the voltage applied to the PEE may be stepped, and take on a number of different values during an exposure step-and-repeat cycle.
[0056] Another approach to extending the useful life of planar electron emitters centers on decreasing the mobility of the metal atoms to migrate (diffuse) into the insulating layer, in other words reducing the diffusion coefficient. Diffusion is a temperature dependent process. In many areas, the temperature dependence of the diffusion coefficient approximates an exponential behavior of the following form;
D ≈constant· e −(ΔE/KT) (1)
[0057] Where D is the diffusion coefficient, K is Boltzman's constant, T is the absolute temperature of the diffusing species, AE is the activation energy of the diffusion process, and the constant depends on the particulars of the materials. As shown is equation (1), the diffusion coefficient can become exceeding small as the temperature approaches absolute zero, in other words the potentially in-diffusing metal atoms may be nearly “frozen in place” at extremely low temperatures.
[0058] In order to test the planar electron emitter's (PEE's) potential increase in useful life at low temperatures, experimental devices were fabricated and tested while being subjected to cooling at liquid nitrogen temperatures—approximately 77 K. The liquid nitrogen cooled devices out-lived their non-cooled counterparts on average by a factor of thirty- to forty-fold. Given this, it may be possible to extend the useful life of the planar electron emitters (PEE's) even further by subjected them to even lower temperatures by using, say, liquid helium temperatures—around 4 K.
[0059] One embodiment of a planar electron emitter (PEE) with integrated temperature control unit 400 is shown schematically in FIG. 4. The planar electron emitter (PEE) 401 is shown in the Metal-Insulator-Metal (M− 1 -M) configuration, where the conducting substrate 402 may be attached to a mounting unit 403 . The mounting unit 403 may be a thermoelectric (TE) cooler or other type of heat extracting device to assist in cooling the planar electron emitter (PEE). The planar electron emitter (PEE) 401 is shown with the insulating layer 404 sandwiched between the conducting substrate 402 and metal overlay 408 similar to the configuration depicted in FIG. 2A. The PEE 401 may be cooled to any desired temperature below room temperature, for example 20K below room temperature, below 100 K below room temperature, or further.
[0060] The mounting unit 403 may in turn be attached to a fluid cooling unit 410 having a series of fluid coolant ducts 412 for delivery of coolants such as liquid nitrogen, liquid helium, or other appropriate coolants. The cooling ducts are closed off form the vacuum chamber in which the wafer is positioned. The fluid cooling unit 410 may also have a temperature getter 414 device placed strategically to be at a lower temperature than the planar electron emitter (PEE) 401 , so as to preferentially attract airborne contaminates in the vacuum chamber to the getter 414 and not to the PEE 401 .
[0061] In one embodiment, the getter 414 device may be situated in the direct flow path of one (or more) of the fluid coolant ducts 412 , whereas the planar electron emitter (PEE) 401 may not be in the direct path of a fluid coolant duct 412 . In this configuration the getter 414 device may be cooled sooner than the planar electron emitter (PEE) 401 and may therefore preferentially attract airborne contaminants to its surface and not the planar electron emitter (PEE) during the initial start-up of the instrument.
[0062] In another embodiment, the fluid coolant unit 410 may time sequence the onset of delivery of cooling fluid to the individual fluid cooling ducts 412 . In this embodiment, the fluid coolant unit 410 may initially only route cooling fluid to the appropriate cooling ducts 412 delivering coolant fluid directly in the vicinity of the getter 414 device. As before, the getter 414 device may be cooled sooner than the planar electron emitter (PEE) 401 and may therefore preferentially attract airborne contaminants to its surface and not the planar electron emitter (PEE) during the initial start-up of the instrument.
[0063] It will be appreciated that other methods may be employed to preferentially cool the getter 414 device prior to cooling the planar electron emitter (PEE) 401 , and that alternative geometries for the getter device 414 may be employed, for example a ring shield around the PEE 401 . Also, the present invention contemplates further, that during the operation of the instrument, it may be useful to maintain the temperature of the getter 414 device at a temperature lower than the planar electron emitter (PEE) 401 . This may prove to be beneficial if the vacuum chamber becomes leaky or malfunctions and allows contaminants to enter the chamber after the onset of electron bombardment.
[0064] It will be appreciated that other approaches to controlling the temperature of the PEE 401 and temperature getter 414 may be employed.
[0065] In another embodiment, the present invention contemplates employing the “reverse bias” procedure(s) described earlier, in simultaneous concert with the low temperature method(s) described above. All possible combinations and permutations of the reverse bias and low temperature methods of extending the lifetime of the PEE are contemplated.
[0066] It will be noted that operation of a PEE without either reverse biasing or cooling leads to a lifetime on the order of 30,000-40,000 exposure shots of 100 msec each. A thirty-fold increase in the lifetime in the lifetime of the PEE, by cooling to liquid nitrogen temperatures, leads to a lifetime of approximately 1 million shots, which is in desired range for a commercial device. Reverse biasing leads to a further increase in device lifetime. Accordingly, the inventions described here enable the PEE to be a serious contender for next generation lithographic procedures. As noted above, the present invention is applicable to lithographic techniques and is believed to be particularly useful in the manufacture of semiconductor components having feature sizes of 50 nm or less. The present invention should not be considered limited to the particular examples described above, but rather should be understood to cover all aspects of the invention as fairly set out in the attached claims. Various modifications, equivalent processes, as well as numerous structures to which the present invention may be applicable will be readily apparent to those of skill in the art to which the present invention is directed upon review of the present specification. The claims are intended to cover such modifications and devices.
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Metal-insulator-metal planar electron emitters (PEEs) have potential for use in advanced lithography for future generations of semiconductor devices. The PEE has, however, a limited lifetime, which restricts its commercial applicability. It is believed that the limited lifetime of the PEE is limited by in-diffusion of metal ions from the anode. The in-diffusion may be countered in a number of different ways. One way is to cool the PEE to temperatures below room temperature. This lowers the metal ion mobility, and so the metal ions are less likely to diffuse into the insulator layer. Another way is to occasionally reverse the electrical potential across the PEE from the polarity used to generate the electron beam. This counteracts the electrical driving force that drives the positively charged metal ions from the PEE anode to the PEE cathode.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is continuation of nonprovisional patent application Ser. No. 12/455,855 filed Jun. 6, 2009 now abandoned by Nasser Saebi for METHODS OF PROVIDING MAN-MADE ISLANDS which claims priority to provisional patent application Ser. No. 61/131,194 filed Jun. 6, 2008 by Nasser Saebi for METHODS OF PROVIDING MAN-MADE ISLANDS.
INCORPORATED BY REFERENCE
The following references are incorporated by reference: U.S. Pat. No. 6,308,490 issued Oct. 30, 2001 and U.S. Pat. No. 6,912,488 issued Jun. 28, 2005 to Nasser Saebi for Method of Constructing Curved Structures as Part of a Habitable Building, U.S. Pat. No. 6,721,684 issued Apr. 13, 2004 and U.S. Pat. No. 6,985,832 issued Jan. 10, 2006 to Nasser Saebi for Method of Manufacturing and Analyzing a Composite Building.
BACKGROUND OF THE INVENTION
Man-made islands have been constructed by moving sand from one location to another location. This is a very expensive proposition.
BRIEF DESCRIPTION OF THE INVENTION
This invention relates to the creation of man-made islands and other like floating structures using composite materials, such as plastic foam coated with a Fiber Reinforced Coating (FRC), such as Glass Fiber Reinforced Concrete (GFRC).
Another alternative is to build a man-made island from materials that are impervious to water and can be fastened to or supported by pilings from the bottom of the water body (sea, ocean, gulf, lake, pond, etc.).
In one embodiment of this invention, plastic foam blocks (16 feet×49 inches×31 inches) are coated with a suitable FRC, such as GFRC. A coating of 0.25 inches of GFRC can be applied to all surfaces. After a suitable setting time, the coated blocks are bonded to each other using a FRC, such as GFRC or another suitable bonding agent. The blocks can be staggered vertically and horizontally.
As an example, the depth of the island can be two blocks (˜60 inches/5 feet). If the plastic used is 1.5 pounds/cu ft Expanded PolyStyrene (EPS), the weight of a cubic foot of EPS will be 1.5 pounds. The weight of a cubic foot of water is 62.5 pounds. Therefore, the block island will float with a loading of less than 5 feetט60 pounds/cu ft or 300 pounds/square foot.
After the foam blocks are bonded together to form a portion of the island. The portion constructed could be the size of a football field (300 feet×100 feet). The coating and bonding could be done on land in an area that can be flooded with water to allow the portion of the island to be floated to the location for the island.
Portions of the island are bonded together to form the island. The island or portions of the island are moored to the floor of the water body or other suitable fixed object using cables or other cable-like means and sea anchors or other anchoring means.
Earth and other landscaping may be added to the island portions to add ballast during transport to the island site.
In another embodiment of this invention, plastic foam blocks (16 feet×49 inches×31 inches) are bonded together to form a portion of the island. The portion constructed could be the size of a football field (300 feet×100 feet). The assembly and bonding could be done on land in an area that can be flooded with water to allow the portion of the island to be floated to the location for the island.
Once the depth or thickness of the blocks (for example, 4-8 feet) has been achieved over the area of the island portion, then the top and sides of the foam structure created by the blocks is coated with a suitable FRC, such as GFRC.
The sides and top are coated with FRC, such as GFRC, and the bottom can be coated or left bare or uncoated. All of the sides or at least some of the sides can be left uncoated. To make a stronger island portion, all of the sides can be coated. Then coating the bottom of the island portion will add additional strength.
Then, the water is allowed in to float the island portion. The portion then can be floated to the island site.
Alternatively, the portion can be made on a barge and transported to the island site in smaller portions.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a perspective view of a house or building and an island or a portion of an island of the invention.
FIG. 2 is a cross-sectional view of a portion of the island.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows island portion 10 with house 20 and landscaping 30 . Island portion 10 is formed from plastic foam with a FRC coating, such as GFRC. The island portion could be moored to land which abuts the body of water or moored to the bottom of the body of water.
The island portion 10 can be joined to another island portion which can provide a road for automobile travel or other conveyance. Another island portion which is similar to island portion 10 can be joined to island portion 10 to provide more building areas on the island.
The building 20 can be built before the other island portions are added and before the island portion 10 is transported to the body of water.
Alternatively, the island or large portions of the island can be built and then the buildings 20 added.
FIG. 2 shows the island 10 with landscaping 30 . The landscaping can be formed from suitable materials such as sand, dirt, etc.
The FRC/GFRC surface of the island has an inclination towards a water catchment tank which allows the island to catch rainwater and reuse it. Filter equipment and pumps can be provided to move the water to points of use. The tank is situated in the plastic foam 11 .
The plastic foam 11 is shown schematically here since it may be made of two pieces of foam in thickness. Preferably the top and side surfaces of the foam island are coated with a FRC, such as GFRC. However, the sides can be left bare or uncoated.
The portions of the island are brought together and bonded to each other using a suitable bonding agent. A suitable bonding agent is GFRG. The bond between GFRC and GFRC has a strength of 70 psi. The bond between GFRC and foam (EPS) has a strength of 40 psi. A tongue and groove connection between the island portions can be provided in the outer surface if desired. The island portion 10 can be coated with 0.25 inches of GFRC for example. The bonding agent, GFRC, can be 0.25 inches or more.
A Finite Element Analysis has been done on the island portion with the building on the portion, and the results proved that the invention provided an acceptable structure for use as a floating island.
Various changes and modifications to the embodiments herein chosen for purposes of illustration will readily occur to those skilled in the art.
The FRC can be a Glass Fiber Reinforced Concrete (GFRC) or a Fiber Reinforced Polymer (FRP). The fibers can be plastic, glass, carbon, single-wall carbon nanotubes (SWNTs or Buckytubes), Aramid or other fibers. The Polymer can be Epoxies, Polyesters, Vinlyesters or other materials.
The coating also can be without fibers if the design loading is low enough. For the strongest structure, fibers should be added to the coating. The number of coats of the coating and the composition of those coats can be varied.
Bonding agents that bond foam to foam, foam to concrete and concrete to concrete can be structural or non-structural as certified by International Code Council (ICC). One structural bonding agent is Glass Fiber Reinforced Concrete (GFRC). A thickness of 0.25-0.50 inches is suitable.
A formula for GFRC is:
1 bag of cement (Portland Cement Type III)—94 pounds,
No. 30 silica sand—100 pounds,
water and ice—25 pounds,
polymer (Forton™ VF-774)—12 pounds,
retarder (Daratard™ 17)—2-5 ounces,
plasticizer (Daracem™ 19)—2-6 ounces,
0.5 inch glass fibers (Cem-FIL™ or Nippon AR™)—1.5 pounds and
1.5 inch glass fibers—1.5 pounds.
A non-structural bonding agent can be expansive plastic foams, such as Expansive PolyUrethane (EPU), etc. This can be used where the joint strength need not be structural, such as a joint that is later covered with FRC to create structural strength.
The type of plastic foam can be different from Expanded PolyStyrene (EPS). The EPS can have a density of 1.5 pounds per cu. ft. (nominal) which is actually 1.35 pounds per cu. ft. (actual). EPS was used because a Finite Element Analysis was done using EPS and GFRC. Suitable plastic foam could be PU, EPS, etc.
The specific materials used to build the structure may be varied, such as the type of plastic foam, the bonding agents, the coatings, etc.
To the extent that such modifications and variations do not depart from the spirit of the invention, they are intended to be included within the scope of the invention.
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This invention relates to the creation of man-made islands and other like floating structures using composite materials, such as plastic foam coated with a Fiber Reinforced Coating (FRC), such as Glass Fiber Reinforced Concrete (GFRC).
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BACKGROUND OF THE INVENTION
1. Technical Field
This device relates to a press used in repairing the damaged portions of a wooden pallet or skid.
Wooden pallets are used to transport a variety of bulk goods and equipment as required in manufacturing and warehousing operations. Wooden pallets are subject to damage in use that occurs from handling with forklifts or the like equipment. Since such pallets are in wide use a large number of damaged and unusable pallets must be repaired or discarded daily. Repair of damaged pallets has become an increasingly sound alternative to disposal due to the sheer volume of pallets that require repair each day. In the repair process damaged portions of the pallets are replaced in a repair station in a multiple conveyor line to facilitate the volume of movement required. As the repairs are made, typically some of the nails used are not driven flush due to existing obstructions, such as original construction nails or wood irregularities. Thus, random upstanding nails if not corrected will damage goods and equipment when in use. Accordingly, it has heretofore been required that a manual inspection be made of each repaired pallet and the upstanding nails be driven down or over by hand or rolling press reducing the efficiency and effectiveness in volume of the pallet repair operation. It would be desirable to have a fully automated high volume pallet nail press to provide a one-stop nail driver which does not require the time consuming visual inspection and manual nail driving hereinbefore required.
It is an object of this invention, therefore, to address this issue and to provide a self-contained automatic pallet nail press which will selectively position a pallet within the press, drive simultaneously whatever nails are upstanding and then exit the press all in an automated operation.
2. Description of Prior Art
Prior art devices of this type do not exist in this specific field. Repair pallet presses have heretofore been used to secure reinforcing nailer plates onto damaged pallet stringers by applying the plates in overlay relation on opposing sides of a damaged portion, see for example U.S. Pat. No. 3,823,861. This patent discloses a pivoted arm that is moved towards and away from an opposing pallet, driving simultaneously oppositely disposed reinforcing nailing plates into the damaged stringer.
A nail rolling apparatus is known to exist as illustrated in a pending Australian patent application which utilizes a series of vertically spaced opposing sets of rollers in which one roller set is movably adjusted for pallet height and rolls over the upstanding nails flattening same.
Analogous fluid driven pneumatic presses are known to use inflatable actuator bags that drive a movable plate forward against a fixed base plate, see for example U.S. Pat. No. 3,376,808.
SUMMARY OF THE INVENTION
An automated continuous pallet nailer press that selectively positions individual repaired wooden pallets within a press support structure vertically lifting each pallet sequentially off a continuous conveyor and engaging the pallet against strategically positioned overhead drive elements which simultaneously drives multiple random upstanding fasteners flush with the surface of the pallet.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the pallet nail press of the invention;
FIG. 2 is an end elevational view of lines 2--2 of FIG. 3 with portions broken away indicating activation of the press with a pallet shown in broken lines within;
FIG. 3 is a top plan view if the pallet nail press of the invention;
FIG. 4 is a side elevational view of a pallet nail press with a portion broken away illustrating activation indicated in use;
FIG. 5 is a simplified representation of an operating sequence for the pallet nail press and accompanying conveyor systems; and
FIG. 6 is a simplified representation of an alternate form of the invention illustrating increased surface area of the lift and press engagement portions.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1 of the drawings, a pallet nail press 10 and an infeed conveyor 11 can be seen. The infeed conveyor 11 is aligned to the left of the pallet nail press 10 and has a pair of horizontally positioned parallel spaced guide tracks 12 on a support frame 13. Continuous conveyor chains 14 are respectively positioned on said guide tracks 12 engaged over drive sprocket assemblies 15 having drive axle 16 and sprockets 17 adjacent the pallet repair press. The drive sprocket assembly 15 is powered by a motor 18 on a support bracket 18A as is well known and understood by those skilled in the art.
A pallet stop bar assembly 19 can best be seen in FIG. 5 of the drawings and is positioned generally between the terminal end of said infeed conveyor 11 and a pallet press conveyor 20.
The pallet stop bar assembly provides an overhead restriction to maintain a pallet P on the infeed conveyor 11 during initial infeed when another pallet is in the pallet nail press 10.
The pallet press conveyor 20 has spaced parallel tracks 20A and respective continuous conveyor chains 20B thereon which extends into and through the pallet nail press 10. A pair of movable pallet indexing pins 21 are positioned inwardly below the pallet press conveyor 20 and are best seen in FIG. 5 of the drawings. Each of the pallet indexing pins 21 are retractable by accompanying piston and cylinder assemblies 21A and can be selectively advanced above the pallet press conveyor 20's surface for engagement with the pallet P as will be described hereinafter.
Referring now to FIGS. 1-4 of the drawings, the pallet nail press 10 has a support frame defining pairs of spaced vertical support beams 23 and 24 with respective upper and lower cross supports 23A and 23B and 24A and 24B. The vertical support beams 23 and 24 are interconnected by interengaging support beams 25 and 26 respectively, best seen in FIGS. 1, 2, and 3 of the drawings and partially broken away in FIG. 4. Pairs of air bags 27 and 28 are positioned on said respective lower cross support 23B and 24B on circular mounting areas defined by multiple upper and lower mounting plates 29 and 30.
Lift beams 31 and 32 are positioned across said respective air bag pairs 27 and 28. Guide pins 31A and B and 32A and B respectively extending from said lower cross support 23B and 24B through aligned apertures in said lift beams 31 and 32.
Each of said lift beams 31 and 32 has longitudinally spaced notches at 33 on its upper surface inwardly from its free ends to provide clearance for the tracks 20A during use.
Multiple hammer I-beams 34, 35, and 36 extend in spaced parallel relation between and on top of said lift beams 31 and 32 completing the movable portion of the pallet nail press 10.
Safety stops 37 extend from and are secured to each of said vertical support beams pairs 23 and 24 by multiple fasteners F. The safety stops 37 prevent unrestricted vertical travel of the hammer I-beams 34, 35 and 36 should a pallet P, best seen in FIGS. 4 and 5 in broken lines, not be positioned within the press by error.
Referring now to FIGS. 1, 2, and 4 of the drawings, a plurality of anvil I-beams 38, 39 and 40 can be seen secured to and extending between said upper support beams 23A and 24A. Each of said anvil I-beams are vertically aligned with a hammer I-beam. Each of said anvil I-beams has a reinforcing plate 38A, 39A and 40A respectively extending along its longitudinal surface opposite said aligned hammer I-beams hereinbefore disclosed. The suspended anvil I-beams 38-40 provide an impact surface for the pallet P as will be discussed hereinafter.
Multiple position and stabilization rods 41, 42, and 43 are threadably secured transversely between and through respective horizontally aligned apertures in said anvil I-beams 38-40. The positioning and stabilization rods 41 and 43 are secured to respective vertical support beam pairs 23 and 24 at their oppositely disposed free ends as best seen in FIGS. 2 and 3 of the drawings while the position and support rod 42 extends only through and between said respective anvil I-beams 38-40.
Referring now to FIGS. 2, 3 and 4 of the drawings, pallet exit stop pin assemblies 44 and 45 are mounted on respective mounting brackets 44A and 45A secured to and extending downwardly from said upper support beams 24A providing for a positive stop and positioning of the pallet P within the pallet nail press 10.
Each of said exit stop pin assemblies 44 and 45 have a registration pin 46 within a guide sleeve 47 interconnected to a piston rod 48 of a piston and cylinder assembly 49 which allows for selective retraction and extension of said registration pin 46 from said guide sleeve 47 as best seen in FIG. 2 of the drawings.
In use, the pallet P enters the pallet nail press 10 and is detected by an electronic sensor 50 that via a control network (as well known within the art) activates pallet exit stop pin assemblies 44 and 45 to a down position and indexing pins 21 to an up position. When the pallet P engages or is about to engage against the exit stop pins 46, a secondary electronic sensor 51 positioned adjacent the exit stop pin assemblies 44 and 45, activates inflation of the air bag pairs 27 and 28 driving the multiple hammer I-beams upwardly lifting the pallet P off the pallet press conveyor 20 against the respective vertically aligned anvil I-beams 38, 39 and 40 thereabove. The pressure exerted by the air bag pairs 27 and 28 is between about 10 lbs. per inch squared to 200 lbs. per inch squared with the optimum pressure being between about 60 lbs. per square inch and 100 lbs. per square inch. Any outwardly extending nails in the pallet are driven into the pallet's surface in one continuous motion. Once the press upward cycle is complete, the air bag pairs 27 and 28 are deflated and the registration pins 46 are retracted allowing the repaired pallet to engage the pallet press conveyor 20 and exit the pallet nail press 10 thereon. As the pallet P clears the electronic sensor 50, it activates the retraction of the indexing pins 21 (down) allowing for a new pallet P to enter the pallet nail press, thus repeating the cycle.
Referring now to FIGS. 2 and 4 of the drawings, it will be seen that they illustrate both an activated and non-activated position of the pallet nail press 10 showing an activated position an elevated pallet P' in broken lines engaged between the anvil I-beams 38, 39 and 40 and the hammer I-beams 34-36 by the respective inflatable air bag pairs 27 and 28 as hereinbefore described. The secondary electronic sensor 51 determines when the pallet P has cleared the pallet nail press 10 reactivating the pallet exit stop pin assemblies 44 and 45 for the next pallet P. The electronic sensor 50 activates the infeed indexing pins 21 as hereinbefore described thereby releasing the next pallet onto the pallet press conveyor 20.
An alternate form of the invention can be seen in FIG. 6 in which the dimensional characteristics of the respective hammer I-beams and anvil I-beams are increased as indicated by modified hammer I-beams 52, 53, 54 and modified anvil beams 55, 56 and 57. The increased dimensional characteristics of said respective alternate I-beam configurations would allow for different pallet engagement areas which might be required in alternate pallet construction or different repair configurations requiring larger pallet engagement surface areas to be addressed.
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A pallet nail press used to drive random fasteners extending from the pallet after repair and assembly has taken place. The pallet nail press includes multiple continuous feed and exit conveyors that pre-position individual repaired pallets within a press support assembly having multiple vertical lift beams below the conveyors. The vertical lift beams are driven by a lift bag assembly. In use, the pre-positioned pallet is lifted off the continuous conveyor and driven against correspondingly positioned anvil beams driving the outwardly extending fasteners flush with the pallet. Sensors activate positioning pins and lift bag air assembly in a selected nature, cycling the pallets through the pallet nail press.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a division of U.S. application Ser. No. 09/970,145, filed on Oct. 2, 2001, now U.S. Pat. No. 7,190,069, which is incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to the field of integrated circuit packaging and more specifically to a method and system of tape automated bonding for an integrated circuit for an implantable medical device such as a defibrillator, pacemaker, or cardioverter.
BACKGROUND
Patients prone to irregular and sometimes life threatening heart rhythms sometimes have miniature defibrillators, cardioverters, and pacemakers implanted in their bodies, typically in the upper chest area above their hearts. These devices detect onset of abnormal heart rhythms and automatically apply corrective electrical therapy, specifically one or more bursts of electric current, to hearts. When the bursts of electric current are properly sized and timed, they restore normal heart function without human intervention, sparing patients considerable discomfort and often saving their lives.
The devices include a set of electrical leads, which extend from a housing into a heart after implantation. Within the housing, among other components, is electronic circuitry for detecting abnormal heart rhythms and for controlling the bursts of electric current through the leads to the heart. The electronic circuitry includes integrated circuits (ICs) which are mounted to a circuit board and connected to various other discrete electrical components by electrically conductive conduits between input/outputs (I/O's) of the IC and the various discrete electrical components.
One method of mounting the IC to the circuit board and providing the interconnections between the IC and the discrete components includes tape automated bonding (TAB). In TAB, interconnection leads are patterned on a flex tape. The tape is positioned above the bare IC chip so that the metal tracks on the tape correspond to I/O bonding sites on the perimeter of the chip. An outer portion of the TAB leads are then connected to contacts on the circuit board. The circuit board includes leads running from the contacts to the discrete electrical components. Since the implantable devices are typically implanted in the left region of the chest or in the abdomen, a smaller size device, which is still capable of performing complex cardiac rhythm management schemes, is desirable.
Accordingly, there is a need to provide a compact implantable device which is capable of performing complex cardiac rhythm management schemes. Furthermore, there is a need to provide methods of manufacturing devices and assembling structures such as the ICs within the implantable devices that provide more efficient and thus less expensive manufacturing.
SUMMARY
To address these and other needs, methods and systems for tape automated bonding have been devised. One aspect of the present system includes a TAB structure. In one embodiment, a TAB structure includes a tape having a conductive lead pattern formed thereon, wherein the conductive lead pattern includes a plurality of leads configured to form an inner lead bond (ILB) portion of the TAB structure. At least one of the plurality of leads is internally routed relative to the ILB portion and has a contact exposed interior to the ILB portion of the TAB structure.
One aspect of the present system includes an electrical device. In one embodiment, an electrical device includes a circuit board, an IC chip mounted to the circuit board, and an electrical component mounted above the IC chip and electrically connected to the IC chip via a lead extending from the electrical component to an I/O of the IC chip.
One aspect includes a method of interconnecting an IC chip to an electronic component. In one embodiment, a method includes connecting the IC to a TAB tape at an ILB portion of the TAB tape and connecting discrete components to one or more leads of the TAB tape at internal portions of the TAB tape within the ILB portion and above the IC chip.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows a top view of a TAB structure according to one embodiment.
FIG. 2 shows a sectional side view of the TAB structure of FIG. 1 .
FIG. 3 is an isometric view of the TAB structure of FIG. 1 having electrical components mounted thereto.
FIG. 4 shows a top view of a TAB structure according to one embodiment.
FIG. 5 shows an isometric view of the TAB structure of FIG. 4 having electrical components mounted thereto.
FIG. 6 shows a block diagram of a generic implantable device including an electrical circuit in accordance with one embodiment.
DETAILED DESCRIPTION
In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which are shown by way of illustration specific embodiments in which the invention may be practiced. It is understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the present invention.
The increases in density that have occurred within ICs have made it possible to provide more functions in each IC, such as more logic gates or more memory bits. This increase in function has made it necessary in many cases to provide more interconnections per IC chip. IC chips have also grown in size to accommodate the larger number of individual circuits, gates or bits required for the expanded functions. The present system and method offers a technique of redistributing the I/O interconnections of an integrated circuit. In one example, a TAB leadframe is utilized to embody the technique.
FIGS. 1-3 show a TAB structure 100 according to one embodiment. FIG. 1 shows a top view of TAB structure 100 . TAB structure 100 is one of a plurality of similar TAB lead-frame structures that are located in a series along a sprocketed tape 110 . Each TAB structure 100 includes tape 110 , such as polyimide or other flex tape, having a conductive lead pattern 120 formed thereon. The TAB structure 100 provides the necessary connections for the perimeter bonded I/Os of an unpackaged or bare IC chip 126 .
IC 126 includes a plurality of IO contact pads 202 (See FIG. 2 ) for providing coupling of the IC to outside components. The I/O contact pads can be located all around the perimeter circumference of a surface of the IC. By way of example, there can be anywhere from approximately 16 to 500 I/O contact pads or more on the chip. IC 126 can be a square or non-square rectangular chip.
In one embodiment, the conductive lead pattern 120 includes a copper etched and gold plated metallization on tape 110 . In one example, in forming TAB structure 100 , a conductor layer composed of Cu or the like is formed on a tape 110 composed of a material such as a polyimide tape or other flex tape. Thereafter, the conductor layer is etched out and thereby a conductive lead pattern is formed.
Conductive lead pattern 120 includes a plurality of leads 123 . The leads 123 of conductive lead pattern 120 include an inner lead bond (ILB) portion 122 and an outer lead bond (OLB) portion 124 . One or more of the IC chip I/O contact pads 202 connect to the one or more of leads 123 at the ILB portion 122 when the IC chip is mounted within an inner frame section 128 of TAB 100 . The inner frame section 128 is dimensioned to hold IC 126 chip therein. OLB portion 124 is for connecting the IC chip to a circuit board, for example. Accordingly, a conductive path is formed from the ILB portion 122 at the I/O of the IC to the OLB portion 124 which is connected to a circuit board.
One or more of the plurality of leads 123 of TAB structure 100 includes internally located contacts 132 . Contacts 132 are located within frame section 128 and are connected interiorly relative to ILB portion 122 . Among other advantages, this allows one or more components to be mounted on or above the surface of the IC and thus within the perimeter of the IC, thus not using up any more footprint area upon a circuit board. In one example, the internally running leads are formed in the same manner along with the rest of lead pattern 120 . Since TAB leadframe cost is relatively constant even with added complexity, the present system does not cause any significant incremental cost to manufacturing or assembly of the TAB.
In one embodiment, a plurality of test contact pads 127 are located on the TAB structure and are connected to one or more of leads 123 . For example, FIG. 1 shows example leads 123 b connected to test contact pads 127 . In some embodiments, each of the plurality of leads 123 are connected to test contact pads. Other embodiments only connect one or more of leads 123 to contact test pads. The present example is shown for sake of clarity. The present TAB structure having test contact pads 127 allows for “known-good-die” testing. Known-good-die testing is electrical testing or bum-in of the integrated circuit prior to committing the expensive discrete components to the overall electrical assembly. Accordingly, in one example use of the present TAB system, once the ILB TAB bonds are completed, the IC 126 can be electrically tested using test contact pads 127 to verify that the circuit is stable and capable of meeting the rigors and high quality standards needed of an implantable defibrillator or pacemaker or other implantable device. The present embodiment accommodates known-good-die testing while still optimizing the surface area utilization above the IC in the form of active circuitry. This results in a smaller, more comfortable, and more reliable implantable device. Moreover, the present structure allows the packaging designer to optimize the circuit board or hybrid surface area which helps to minimize overall device volume while still allowing for complex electronic functions.
One advantage of the present structure is that it allows for reductions in electrical impedance between the IC and the associated discrete electrical components due to the very short and direct connections between the IC and the components mounted above the IC. The structure also reduces the number of electrically redundant interconnects between the IC, the components above the chip, and the hybrid (motherboard) by utilizing a continuous stitch TAB inner lead bond approach to make the necessary electrical connections. In the past, the IC was connected to the hybrid, such as a circuit board, and then a lead went from the hybrid to the component. Now a component can utilize the TAB lead itself as the component's direct interconnect.
Moreover, the present internal contacts 132 allow for lower cost and less complex manufacturing. This is because the internal contacts 132 allow a component to be mounted with a one-step manufacturing process to the IC. A typical two-step process of first mounting the component to the circuit board and then connecting the component to the IC is reduced to mounting the component directly within the frame of the TAB structure with its built-in connection.
FIG. 2 shows a schematic representation of a cross-section of portions of TAB structure 100 . In this embodiment, example lead 123 D extends from a test contact pad 127 to OLB portion 124 to ILB portion 122 and to inner contact 132 located above the major surface of chip 126 . In this example, a conductive filler material 133 is used to make the connection between lead 123 D and inner contact 132 .
Chip 126 includes I/O contact 202 for making the connection to the lead. In other examples a lead such as lead 123 D can extend only inward, for example, from ILB 122 to contact 132 . Other leads extend only outward, for example, from ILB 122 to OLB 124 .
FIG. 3 is an isometric view of TAB structure 100 having electrical components, such as components 302 , 304 , 306 , and 307 , mounted thereto. In this example, ILB portions 122 are connected to the I/Os of chip 126 and OLD portions 124 have been bent into a gull-wing configuration in preparation for mounting onto a circuit board. An example lead 123 C runs from IC I/O 202 to inner contact 132 . Components 302 , 304 , 306 , and 307 can be soldered to contacts 132 . Alternatively they can be connected by an electrically conductive epoxy. Other equivalent connection techniques are within the scope of the present system.
FIGS. 4 and 5 show a TAB structure 400 according to one embodiment. FIG. 4 shows an isometric view of TAB structure 400 . Tab structure 400 includes similar features to TAB structure 100 and certain details will be omitted for sake of clarity. TAB structure 400 generally includes a tape 410 having a conductive lead pattern 420 formed thereon. Conductive lead pattern 420 includes a plurality of leads 423 . The leads 423 of conductive lead pattern 420 include an ILB portion 422 and an OLB portion 424 .
One or more of the plurality of leads 423 of TAB structure 400 includes internally located contacts 432 . Contacts 432 are located within frame section 438 and are connected interiorly relative to ILB portion 422 . This allows one or more components to be mounted above the surface of an IC and thus within the perimeter of the IC, thus not using up any more footprint area upon a circuit board.
In one embodiment, TAB structure 400 includes internally located contacts 425 . In this example, inner contacts 425 do not include contact pads such as provided for inner contacts 432 . Inner contacts 425 include a bare portion of portions of each of one or more of leads 423 and are internally located relative to ILB portion 422 . Again, inner contacts 425 allow one or more components to be mounted above the surface of the IC and within the perimeter of the IC, thus not using up any more footprint area upon a circuit board.
FIG. 5 is an isometric view of TAB structure 400 having an IC chip 526 mounted thereto and having electrical components, such as components 502 , 504 , 506 and so on, mounted thereto. ILB portions 422 are connected to the I/Os 528 of chip 526 and OLB portions 424 have been bent into a gull-wing configuration in preparation for mounting onto a circuit board 532 . In this example, lead 423 D is attached to an I/O 528 of IC 526 . One end of lead 423 D extends to OLB portion 424 and a second end extends to an inner contact 432 (see FIG. 4 ), which in FIG. 5 has a component 504 mounted thereon. Again, the present TAB structure provides that components such as component 504 do not take up any space on the surface of the circuit board.
This example also shows a lead 423 E connected to an I/O 528 of the IC. Lead 423 E includes a first end extending to OLB portion 424 and a second end extending internally to inner contact 425 , where inner contact 425 is attached to the I/Os of component 506 . In this example, component 506 is an IC chip having similar I/Os as shown for IC chip 526 . Thus, the present embodiment allows the back-to-back, internally located mounting of a second IC chip 506 relative to a first IC chip 526 .
FIG. 6 shows one of the many applications for circuit boards incorporating one or more teachings of the present TAB system: a generic implantable device 600 . As used herein, implantable device includes an implantable device for providing therapeutic stimulus to a heart muscle. Thus, for example, the term includes pacemakers, defibrillators, cardioverters, congestive heart failure devices, and combinations of these devices.
Device 600 includes a lead system 603 , which after implantation electrically contacts strategic portions of a patient's heart. Shown schematically are portions of device 600 including electrical circuitry such as a monitoring circuit 602 for monitoring heart activity and for detecting abnormal heart rhythms through one or more of the leads of lead system 603 , and a therapy circuit 601 for controlling and delivering bursts of electrical energy through one or more of the leads to a heart. Device 600 also includes an energy storage component, which includes a battery 604 and a capacitor 605 . Therapy circuit 601 and monitoring circuit 602 can both include circuit boards or hybrids having electrical devices which include one or more of the TAB features described above. In one example, the electrical circuitry of device 600 includes application-specific integrated circuits (ASICs) to monitor, regulate, and control the delivery of electrical impulses to the heart. The present TAB structure allows a packaging designer to increase hybrid efficiency by turning the otherwise passive IC surface into an electrically active design element and therefore offering a significant reduction in the size of implantable device 600 .
It is understood that the above description is intended to be illustrative, and not restrictive. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.
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A tape automated bonding (TAB) structure which includes a flex tape having a conductive lead pattern formed thereon. The conductive lead pattern includes a plurality of leads configured to form an inner lead bond (ILB) portion of the TAB structure. At least one of the plurality of leads is internally routed and has a contact exposed interior to the ILB portion of the TAB structure.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a drive-up transaction arrangement and particularly to an arrangement servicing a plurality of vehicle lanes for banking purposes or the like.
2. Description of the Prior Art
Drive-in arrangements are well know in the prior art, among which the more commonly known are those in the quick service food business, such as drive-in restaurants. In such arrangements service is usually provided by "car hops" and the customer generally must back out of the service area instead of driving through it.
In other prior art drive-in transaction arrangements, service is frequently provided by tellers enclosed in service counters at ground level so that the most advantageous use of ground space is not taken into account.
A disadvantage of other prior art arrangements lies in the fact that visual confrontation is not always afforded between the parties of the transactions.
Examples of prior art drive-in service arrangements of the general types hereinabove described are disclosed in the following U.S. Pat. Nos. 1,819,806; 3,077,243 and 3,556,437.
SUMMARY OF THE INVENTION
The present invention comprises a new and improved drive-in service arrangement which affords the most economical use of available ground space. The improved drive-in arrangement according to the present invention generally comprises one or more overhead servicing compartments from which a protected attendant or teller may transact business remotely with drive-in customers in at least two lanes therebelow. An additional object of this invention is to provide a remote transaction arrangement in which there is visual contact between the parties to the transaction.
Still another object of this invention is to provide a drive-in service arrangement in which the service compartments enclosing the teller or attendant comprise prefabricated plug-in modules which may be conveniently extended or terminated in a line.
A further object of this invention is to provide a drive-in service arrangement which may if desired be quickly disassembled and moved or re-arranged.
Still further objects of the present invention are to provide an improved service arrangement for remote transactions which is of rugged and durable construction and yet require a minimum of time and effort in assembling and/or re-arranging, and which is otherwise particularly well adapted for its intended purpose.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is a front elevational view of the preferred arrangement according to this invention;
FIG. 2 is an elevational view of the arrangement according to FIG. 1 taken along a transverse section of one of the compartments in the arrangement;
FIG. 3 is a plan view of the arrangement shown in FIG. 1 with portions thereof broken away; and
FIG. 4 is a longitudinal section view through a pair of interconnected compartments showing details of the interconnected end portions thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now more particularly to the drawing the assembled compartments according to this invention form a service arrangement, as shown in FIGS. 1-3, which is adapted, in particular, for use in conducting banking transactions with drive-in customers, although it may be equally well adapted to other types of service including the merchandising of goods, dispensing of food, and the like. Thus as shown in FIG. 1, a first compartment module 10 is seen to be annexed to a bank building B proper. Interconnected to the first compartment module 10 in an extensible chain are a series of compartment modules 12, 14, and 16. The modules 10, 12, 14 and 16 are delineated from each other in FIG. 1 by the line 11 and are arranged above ground level to permit the passage of customer vehicles in lanes L1, L2, L3 and L4, respectively, formed therebelow. Each compartment module is supported above ground level by columns 13 and 15, such as shown in FIG. 2, which preferably are of prefabricated reinforced concrete or like material. Each of the compartment modules 10, 12, 14 and 16 are made of completely armored material and include transparent windows 17, 19, 21, etc., which are of armored plate glass.
A pair of conveyor chutes 18 and 20 are interconnected to module 10 and extend downwardly and forwardly therefrom to ground level at lanes L1 and L2. Pull-out drawers 23 and 25 are provided in the vertical extensions of chutes 18 and 20, respectively, generally at the window level of customer vehicles. Similarly, conveyor chutes 22 and 24 extend downwardly and forwardly from compartment module 14 and include pull-out drawers 27 and 29, respectively, in the vertical extensions thereof. Although conveyor chutes 18 and 20 are equipped on compartment module 10, they may instead be located in conjunction with compartment module 12. Similarly, conveyor chutes 22 and 24 may be connected to compartment module 16 instead of to compartment module 14. Thus, as shown in FIG. 3, conveyor chute 22 may also be attached to compartment module 12 as shown in phantom instead of to compartment module 14, in which case module 14 would only have chute 24 extending therefrom.
The chain of compartment modules, which as shown in FIG. 1, includes modules 10, 12, 14 and 16 may be terminated by the omission of module 16 therefrom. With module 16 omitted from this chain the remaining modules 10, 12 and 14 will be adequate to service the lanes L1, L2, L3 and L4. The lane L4, as shown in FIG. 1, is specially constructed at a lower level than lanes L1, L2 and L3 to provide adequate clearance and thus accommodate trucks and other vehicles larger than conventional passenger cars.
Extending vertically and in front of the vertical portion of conveyor chute 18 is a support beam 26 at the top of which extends a cantilevered supported shield 31 which shelters the pull-out drawer 23 from rain, snow, and the like. Similar support beams 28, 30 and 32 provide shields 33, 35, and 37 over pull-out drawers 25, 27 and 29, respectively.
Compartment module 10 includes an arched roof 34 as shown in FIG. 2. Similarly arched roofs 36, 38, and 40 are provided on compartment modules 12, 14 and 16, respectively.
As mentioned above each of the compartment modules include male and female end portions on opposite ends thereof with the male end portion 10' of compartment module 10 telescopically interfitted within female end portion 12' of compartment module 12 as shown in FIG. 4. Appropriate seal elements 39 and 41 may be placed in the area defined by the line of separation 11, for example, in the vicinity between the shoulders and extreme edges of the end portions 10' and 12', respectively.
To carry out a transaction with a teller in compartment module 10, for example, a bank customer may drive up to pull-out drawer 23, pull out the drawer 23, insert his cash or check, and close the drawer 23. The teller in compartment module 10 whose line of sight S allows him to visually confront the customer seated in his car may then activate the conveyor mechanism within chute 18 to gain access to the customer's business and make whatever change or return to the customer by any conventional conveyor means. As a further matter of convenience, an intercom system may be provided for conversation between the participants of the transaction. While one teller or attendant may service two lanes, the compartment module 10, for example, has adequate room for two attendants in the event that more than one attendant is desired in a service module during peak business hours.
The prefabricated compartment modules as described above thus may be conveniently brought on the site, easily moved, arranged and assembled. Further, the assembly of compartment module chain may be easily extended or shortened as desired. In practice each module may be aptly made approximately eight feet deep by nine or ten feet long. Suitable securing means such as bolts located internally of the compartments, for example, may be applied to lock the plug-in end portions to each other. Alternatively, heavy duty clamping means may be provided to lock the assembled modules together.
Although I have described my invention with a certain degree of particularity, it is understood that the present disclosure has been made only by way of example and that numerous changes and details may be resorted to without departing from the spirit and scope of the invention as hereinafter claimed.
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An extensible overhead personnel enclosure compartment assembly forming a drive-in transaction annex to a building proper. The enclosure assembly comprising a plurality of compartment modules each of which includes male and female end portions for plug-in interconnection with adjacent modules to form said extensible assembly.
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FIELD OF THE INVENTION
[0001] The present invention relates to a method and a device for setting, in particular equalizing or flattening, the frequency dependent gain due to polarization shifts in an optical amplifier, such as a Raman optical amplifier, used in a WDM system.
BACKGROUND
[0002] In recent years, the increasing demand for information capacity of optical fiber systems has made telecommunications manufacturers develop methods and devices for in particular wavelength division multiplexing (WDM). For these systems, the signal information is transmitted on distinct channels of optical light. The signal information can comprise a plurality of logical signal channels, and each signal channel may, in turn, include both time division multiplexed (TDM) and space division multiplexed (SDM) components, space division multiplexing (SDM) meaning that separate fibers are used for different parts of a message transferred in a logical channel.
[0003] The preferred wavelengths for most telecommunication optical fiber systems are in the infrared part of the spectrum, around 1500 nm, due mostly to the low attenuation and the low signal pulse broadening when transmitting signals on optical fibers in this region, but also because of the availability of suitable light sources and detectors. In particular for WDM, another advantage here is the availability of various types of optical amplifiers. These are necessary since each wavelength channel carries only a small portion of the total power of light propagating in the fiber and thus needs to be amplified to compensate for optical losses in the fiber link, in order to get a sufficient signal-to-noise ratio at the receiver end.
[0004] There are various designs of optical amplifiers. The most important ones for telecommunication applications include erbium-doped fiber amplifiers (EDFA), semiconductor optical amplifiers (SOA), Raman amplifiers (RA), and optical parametric amplifiers (OPA). These amplifiers have specific advantages and disadvantages.
[0005] Raman amplifiers are of a special interest due to some important features. Such amplifiers differ from the others mentioned above in that the gain thereof is distributed over a given length of the optical fiber used, the Raman fiber. The Raman fiber is connected in series with the ordinary transmission fiber, preferably near the transmitting light source. The power necessary for the amplification is delivered by pumping light from at least one separate pump light source. The maximum value and the shape of the Raman gain depend on the wavelength of the light emitted by the pump light source, rather than on the fiber itself. Usually, injection of pump power takes place near the input end of the Raman fiber, using, e.g., a fiber-optical coupling device. Pump light of different wavelengths from several distinct pump light sources can be injected in parallel in order to achieve a desired shape of the Raman gain, see the published International patent application WO 00/49721. A problem with this pumping method is that nonlinear interaction may take place between the various wavelength contributions. Also, the need for several pump light source and the intricate control thereof make such amplifiers complicated and costly.
SUMMARY OF THE INVENTION
[0006] It is an object of the present invention to provide a method of setting, in particular flattening, the gain of an optical amplifier such as a Raman amplifier and particularly to provide a reduction of the wavelength dependency of an optical amplifier used in a WDM system.
[0007] The above object is achieved by controlling, in a suitable way the optical polarization states of the various channels at the input of a WDM system to give a desired gain curve. This allows for using a single pump source providing light of only one wavelength, instead of a multitude of pump light sources providing light of different wavelengths that is controlled as to its power, or a multiwavelength pump source, in which the light of each wavelength is controlled individually as to its amplitude. The use of a single wavelength pump source is also advantageous, because many different pump wavelengths may create non-linear interaction between the pump contributions. The method of controlling the input polarization states also makes the optical amplifier that thereby obtains the desired gain robust and relatively uncomplicated. Due to the fact that only a single pump light source is required, the amplifier has also a relatively small cost.
[0008] Using the control of the input polarization states the gain can be controlled to have any predetermined shape within two maximum and minimum shapes. In this way, e.g. the gain tilt due to polarization dependent losses may be compensated for over the whole optical link in which the optical amplifier is connected.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Embodiments of the present invention will now be described by way of example, with reference to the accompanying drawings, in which:
[0010] [0010]FIG. 1 is a schematic picture of a Raman amplifier,
[0011] [0011]FIG. 2 is a diagram showing the maximum (solid line) and minimum (dashed line) Raman gain profiles around a wavelength of 1555 nm,
[0012] [0012]FIG. 3 is a diagram showing the flattening of the Raman gain over a bandwidth of 32 nm, and
[0013] [0013]FIG. 4 is a diagram showing the actively controllable change of Raman gain within the maximum and the minimum gains.
DETAILED DESCRIPTION
[0014] In the following description, a Raman amplifier is used as a typical example of an amplifier for which the method can be used. For other amplifiers having a similar behaviour comprising a gain dependent on the polarization states of the different amplified channels, the same method can obviously also be used.
[0015] [0015]FIG. 1 is a schematic diagram showing an actively controlled Raman amplifier 1 connected at the input side of a WDM system. A plurality of input fibers 2 , each carrying light signals of an individual wavelength channel, are connected to the input terminal of a WDM multiplexer (MUX) 3 . The light of each wavelength channel entering the multiplexer 3 is controlled as to its optical polarization state by a polarization controlling unit 4 . The output terminal of the WDM MUX 3 is connected to the Raman fiber 5 . Two optical couplers are connected in the Raman fiber 5 , one 6 a near the input end 7 a thereof and one 6 b near the output end 7 b thereof. Typically, such couplers may consist of two fibers fused together. To one of the input terminals 9 a of the input end coupler 6 a is an optical pump source 8 connected, injecting single wavelength light. A multiple wavelength pump source is not needed because the corresponding effect for the system as a whole is achieved by using the plurality of polarizers 4 , as will be described hereinafter. At the output end coupler 6 b one of its output terminals 9 b is connected to a channel power monitoring device 10 consisting of an array of optical sensor elements, each sensor element measuring the power of a specific channel wavelength, the power received in each element being converted to a corresponding electrical signal. After analog/digital conversion each signal is further processed by an electronic control unit 11 providing control signals fed back to control each of the elements of the array obtained in the cases where the pumping signals having orthogonal and parallel polarizations respectively in relation to the polarization of the light of polarizers 4 .
[0016] A method of controlling the polarizers 4 in order to achieve a predetermined gain curve such as a flattening of the gain obtained at the output end of the Raman fiber will now be illustrated by means of the exemplary diagrams of FIGS. 2-4. The dashed curve of FIG. 2 thus shows the minimum gain and the solid curve shows the maximum gain for light propagating through a Raman fiber and amplified by light from a pump light source as a function of the wavelength of the amplified light in a typical case for a wavelength band located about a center wavelength of 1555 nm. The minimum and the maximum gains are being amplified. In a real case the gain will be somewhere in between these curves due to statistically varying properties of the Raman fiber. Thus it can be generally seen that the gain as measured at the output end 7 b of the Raman fiber depends on the wavelength of the amplified light. Also, the gain depends on the power and polarization state of the input light that is amplified in the Raman fiber.
[0017] In the diagram of FIG. 3 a most favorable value of flattened gain in a Raman fiber is illustrated by the horisontal solid line, this value being equal to the peak value of minimum gain curve. For this gain value a maximum flattened bandwidth of 32 nm could be achieved. This case can be obtained by an individual, appropriate control of the channel polarizers 4 .
[0018] An extension of the flattening control concept may be carried out, as illustrated by FIG. 4. The thick middle line having an irregular shape here illustrates some desirable shape of the gain in the Raman fiber and is located between the maximum and the minimum gain curves. By an appropriate individual control of the channel polarizers 4 any shape of the gain as function of the wavelength can be actually obtained within the constraints. In particular, this includes flattened gain shapes having a higher gain but having smaller bandwidths than that illustrated in FIG. 3. Another possibility is the compensation of gain tilts due to wavelength dependent polarization losses over e.g. the optical link connected to the output end 7 b of the Raman fiber. Furthermore, in combination with chromatic dispersion compensation in fibers of DCF type the method described herein of adapting the gain in a Raman amplifier with wavelength may be very useful.
[0019] A general control scheme executed by the control unit 11 can be as follows. The control unit 11 sends control signals to the polarizers 4 for adjusting the polarization of the light in the channels. The signals output from the elements of the optical sensor 10 representing the power in the channels are compared to the desired gain in the channels, while adjusting the corresponding elements of the array of polarizers 4 in small increments. When the desired gain has been reached for a channel, the adjustment of the polarizer for this channel is stopped.
[0020] A control scheme executed by the control unit 11 for setting the flattened gain as illustrated by the solid line in FIG. 3 can be as follows. The first task is to find a minimum curve similar to that shown in FIG. 3. Thus, the control unit 11 sends control signals to the polarizers 4 for adjusting the polarization of the light in the channels to obtain the minimum gain value for each channel, i.e. the minimum power level of the channel for changing polarization states of the respective input signal. Hence, the signals output from the elements of the optical sensor 10 representing the power in the channels are evaluated and stored, while adjusting the corresponding elements of the array of polarizers 4 in small increments. If the power increases when rotating the polarization by one increment in one direction, in the next trial a control signal having a value is produced rotating the polarization by the same step but in the opposite direction. On the other hand, if the power decreases, the rotation direction when changing the polarization state is maintained. This procedure is repeated for each channel until a state is achieved in which an adjustment of the polarization in either direction gives no further change or gives an increased gain. The minimum value of the power is then represented by the actual signal from the corresponding element of the channel sensor 10 . Thereupon the different stored values representing the minimum power levels for the amplified light of all WDM channels are evaluated and the maximum or peak value and the wavelength channel for which it is obtained are determined.
[0021] The next task is to adjust the gain in the WDM channels or more specifically the power level, as observed at the output end of Raman fiber 5 , to the level of the determined peak value for as many channels as possible which is the gain flattening procedure. Then, the stored values of the detected power levels can be evaluated again and for some channels, the correct polarization state to achieve a gain equal to the determined peak value can be directly set as indicated by the stored values. For other channels, the adjustment method is continued, i.e. the signal representing the optical power output from the respective elements of the optical sensor 10 is evaluated, again while adjusting the corresponding polarizer elements 4 in small increments until the absolute difference between the determined peak value and the read power level reaches a minimum. If the absolute difference increases for rotating the polarization in one direction, the direction is changed for the next rotary increment, and if the difference decreases, the direction when changing the polarization state is maintained. This procedure will continue until no further change in the absolute value of the power difference is observed or until the absolute values thereof increases for rotation of the polarization state in either direction.
[0022] The method of applying individual polarizers 4 at each WDM channel input in combination with using a single wavelength pump source 8 has the equivalent effect on the Raman gain profile as by instead using a multiwavelength pump source, where each spectrum line contribution is controlled as to its polarization and amplitude. An advantage of using a single wavelength pump source is that non-linear interaction between different spectrum lines can be avoided.
[0023] As has already been mentioned and as should be obvious to anyone skilled in the art, the method described herein comprising control of the polarization states of different wavelength channels input to an optical amplifier can be used in any optical amplifier for which the gain of the optical amplifier for light of each of the wavelengths channels are dependent on the optical polarization state of the light of the respective channel.
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For setting the optical gain of an optical amplifier such as a Raman amplifier that is connected in a wavelength division multiplexing (WDM) system, the gain of the amplifier is made dependent on the states of optical polarizers connected to individual inputs of a WDM multiplexer. The polarizers can be actively controlled by a device connected to sense the output power of the Raman fiber at different wavelengths. For an appropriate control the optical gain can be given any desired shape such as for example a reasonable flatness. The control of the polarization states of the WDM-channels allows for the use of a single wavelength pump source of the amplifier, instead of the conventionally used multiwavelength source.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention is directed to a process for reducing the amount of ortho nitro aromatic keto compounds in a mixture containing the same which comprises contacting such mixture with oleum.
2. Description of the Prior Art
Ortho nitro aromatic keto compounds can be found in mixtures wherein their presence is not desired and, obviously, reducing their presence therein, or better still, reducing them entirely, would be highly desirable. For example, diaminobenzophenones, obtained by nitrating benzophenone with nitric acid and thereafter subjecting the resulting dinitrobenzophenones to hydrogenation, can be reacted with a dianhydride, such as 3,4,3',4'-benzophenone tetracarboxylic dianhydride (BTDA) to obtain a polyimide. When the benzophenone is reacted with nitric acid to form the dinitrobenzophenone, a mixture of isomers can be formed, for example, o,o'-dinitrobenzophenone, o,m'-dinitrobenzophenone, o,p-dinitrobenzophenone,m,m'-dinitrobenzophenone,m,p'-dinitrobenzophenone and p,p'-dinitrobenzophenone. Although the m,m'-, m,p'- and p,p'-diamino benzophenones obtained from said mixture will react satisfactorily with BTDA to form desired longchain polyimide resins, the diaminobenzophenones containing an ortho amine substituent will react with BTDA to a lesser extent, resulting in a mixture of long and relatively short polyimide resins. This is believed to be the result of hydrogen bonding between an ortho amine hydrogen and the carbonyl which reduces the basicity of the compound and renders the compound less reactive with BTDA. It would be highly desirable, therefore, to reduce the content of an ortho nitro aromatic keto compound containing the same.
SUMMARY OF THE INVENTION
We have discovered that the ortho nitro aromatic keto content of a mixture containing the same can be reduced by contacting said mixture with oleum.
The ortho nitro aromatic keto compounds, or mixtures of such compounds, referred to above, can be defined, for example, in accordance with the following formula (A): ##STR1## wherein R 1 can be an alkyl radical having from one to 10 carbon atoms, preferably from one to four carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, secbutyl, isobutyl, neo-pentyl, n-decyl, etc., an aryl radical having from six to 20 carbon atoms, preferably from six to 10 carbon atoms, such as phenyl, naphthyl, p-tolyl, m-tolyl, o-tolyl, m-chlorophenyl, o-bromophenyl, m-nitrophenyl, p-nitrophenyl, etc.; or an aroyl radical having from six to 20 carbon atoms, preferably from six to 10 carbon atoms, such as benzoyl, m-nitrobenzoyl, p-nitrobenzoyl, m-chlorobenzoyl, p-bromobenzoyl, etc.; R 2 can be a halogen, such as chloro, bromo, iodo and fluoro, nitro, cyano, or alkyl, aryl or aroyl radicals, as defined above; and n is an integer ranging from 0 to 4, generally from 0 to 2. Specific examples of such compounds include o-nitrobenzophenone, o-nitro-p'-chlorobenzophenone, o,o'-dinitrobenzophenone, o,m'-dinitrobenzophenone, o,p'-dinitrobenzophenone, o-nitroacetophenone, o-nitrobenzil, o-nitro-p'-benzoylbenzophenone, o-nitro-m'-chlorobenzophenone, o-nitro-p'-bromobenzophenone, o-nitro-m' methylbenzophenone, 2-nitro-4,4'-dimethylbenzophenone, 2,2'-dinitro-4,4'-dichlorobenzophenone, 2-nitro-5-chloroacetophenone, 2,4-dinitroacetophenone, 2 -nitro-4,5,3',4'-tetramethylbenzophenone, 2-nitro-3'-cyanobenzil, etc.
The second component (B) of the mixture being treated herein can be composed of one or more compounds that are substantially inert or unreactive when contacted with oleum under the conditions of temperature and time defined hereinafter. Generally, the second component (B) will be composed of one or more compounds similar to component (A), defined above, but wherein no nitro substituent is present ortho to the keto carbonyl. Specific examples of compounds that can be defined as component (B) include p-nitrobenzophenone, m-nitrobenzophenone, m,m'-,m,p'-dinitro-, and p,p'-dinitrobenzophenones, m-nitro-and p-nitroacetophenones, m-nitro- and p-nitrobenzils, m-nitro-m'-chloro- and m-nitro-p'-chlorobenzils, m-nitro-m'-bromobenzophenones, p-nitro-p'-bromobenzophenone, m-nitro-m'-benzoylbenzophenone, m-nitro-m'-(3-nitrobenzoyl)benzophenone, etc.
The weight ratio of component (A) to component (B) can vary over a wide range, for example, from about 0.1:99.9 to about 60:40, but, in general, the weight ratio will be in the range of about 5:95 to about 40:60.
As mentioned above, the defined mixture is contacted with oleum to reduce the ortho nitro aromatic keto content thereof. By "oleum" we mean to include concentrated sulfuric acid (100 weight percent sulfuric acid) containing sulfur trioxide. The amount of sulfur trioxide, on a weight basis relative to the total weight of sulfuric acid and sulfur trioxide, will be in the range of about five to about 65 percent, preferably about 10 to about 35 percent. Oleum suitable for use herein can be prepared, for example, by adding gaseous or liquid SO 3 to concentrated sulfuric acid. It is believed that sulfur trioxide when dissolved, or added to, in sulfuric acid readily forms H 2 S 2 O 7 and higher polysulfuric acids [R. Gillespie, J. Chem. Soc., 2493 (1950)].
In carrying out the process defined herein the oleum and the mixture being treated are admixed in a weight ratio of about 1:1 to about 25:1, but preferably in a weight ratio of about 2:1 to about 5:1. During such contact, which can be about 0.1 to about 48 hours, generally in the range of about 0.5 to about six hours, the temperature of the reaction mixture is maintained within the range of about 10° to about 100° C., preferably about 20° to about 90° C. Pressure is not critical herein and any suitable pressure, including elevated pressures, can be employed, but, in general atmospheric, or ambient, pressure is satisfactory.
At the end of the defined treatment the product can be recovered by pouring over ice and filtering or extracting with a suitable solvent. The filter cake or extract can be washed with water and caustic and dried. The resultant product will be essentially free of the ortho nitro aromatic keto compounds originally present.
We believe that during the treatment herein the ortho nitro aromatic keto will be converted to lower benzoic acids, phenolics, carbon dioxide and other caustic-soluble products.
DESCRIPTION OF PREFERRED EMBODIMENTS
The process defined and claimed herein can be illustrated by the following.
EXAMPLE A
A nitrating mixture was prepared by adding gradually 165 grams of 90 weight percent aqueous nitric acid over a period of 30 minutes to 570 grams of oleum containing 22.5 weight percent of sulfur trioxide. During the addition the oleum was continuously stirred and the temperature of the resulting mixture was maintained at about 10° to about 15° C. The first third of the nitric acid addition was highly exothermic, the second third mildly exothermic and the last third essentially non-exothermic. Similarly 200 grams of benzophenone were added over a period of 30 minutes to 1900 grams of oleum containing 22.5 weight percent of sulfur trioxide while maintaining the temperature of the mixture in a temperature range of about 10° to about 20° C. With vigorous stirring and cooling, the nitrating mixture prepared above was gradually added over a period of 1.5 hours to the benzophenone mixture prepared above while maintaining the temperature of the resulting mixture in the range of about 10° to about 15° C. The resulting mixture was permitted to rise to 25° C. and held there for 30 minutes, after which the mixture was heated to 70° C. and maintained at the latter temperature for 30 minutes and then cooled to 25° C. The resulting product was poured over 2,000 grams of a cracked ice-water mixture and filtered. The recovered solids were washed twice with 1000 milliliter portions of water, thereafter with 1000 milliliters of a 10 weight percent aqueous sodium hydroxide solution and finally twice with 1000 milliliter portions of water, until the final washings were found to have a neutral pH value. The solid product was dried in a vacuum oven at 100° C. for 20 hours, resulting in 289 grams of dinitrobenzophenones, corresponding to a yield of 96 percent. Analysis of the product by high performance liquid chromatography (HPLC) showed the presence of the following isomers: 89.1 weight percent m,m'-dinitrobenzophenone, 5.9 weight percent m,p'-dinitrobenzophenone and 5.0 weight percent o,m'-dinitrobenzophenone.
EXAMPLE B
In this example, 200 grams of benzophenone was incrementally added over a period of one hour, while stirring, to 1200 grams of 90 weight percent of aqueous nitric acid while maintaining the temperature during addition between about 65° and 75° C. After addition of benzophenone was complete, the temperature of the mixture was raised to 90° C. and the reaction was permitted to continue at such temperature for three hours. The solution was cooled to room temperature (25° C.) and then poured, while stirring, over 2000 grams of cracked icewater mixture. The precipitated solids were recovered by filtration, washed four times with water (1000 milliliters each time) until the final washings were essentially neutral, and then dried in a vacuum oven for 24 hours at 100° C. The cream-colored product recovered amounted to 299 grams, corresponding essentially to a yield of 100 percent. Analysis of the product by HPLC showed the following isomer distribution: 7.9 weight percent o,o'-dinitrobenzophenone, 29.7 weight percent o,m' -dinitrobenzophenone, 44.4 weight percent m,m'-dinitrobenzophenone, 17.2 weight percent m,p'-dinitrobenzophenone and 0.8 weight percent p,p'-dinitrobenzophenone.
EXAMPLE C
Herein 110 grams of benzophenone was added gradually, over a 30 minute period, while stirring, to 1100 grams of 98 weight percent aqueous sulfuric acid while maintaining the temperature, during the addition, at about 25° C. In another container, a nitrating mixture was prepared by gradually adding, over a 90 minute period, while stirring, 84 grams of 90 weight percent aqueous nitric acid to 276 grams of concentrated sulfuric acid, while maintaining the temperature of the mixture during the addition between about 20° and 25° C. The latter mixture was then added, by way of an addition funnel, to the dissolved benzophenone at a rate sufficient to maintain the temperature of the resulting mixture slightly below about 30° C. Upon completion of the addition, the resulting mixture was allowed to react at 30° C. for 30 minutes and then at 50° C. for 30 minutes, and finally at 70° C. for 30 minutes. The product was cooled and worked up as in Example A, resulting in the production of 163.7 grams of dinitrobenzophenones, essentially 100 percent yield. Analysis of the product by HPLC showed the following: 2.5 weight percent o,o'-dinitrobenzophenone, 20.6 weight percent o,m'-dinitrobenzophenone, 65.2 weight percent m,m'-dinitrobenzophenone, 11.7 weight percent m,p'-dinitrobenzophenone and <0.1 weight percent p,p'-dinitrobenzophenone.
EXAMPLE D
Example A was repeated except that 2400 grams of oleum containing 15 weight percent of sulfur trioxide was used. The product obtained contained the following isomers: 1.6 weight percent o,o'-dinitrobenzophenone, 17.0 weight percent o,m'-dinitrobenzophenone, 71.5 weight percent m,m'-dinitrobenzophenone, 10 weight percent m,p'-dinitrobenzophenone and 1.0 weight percent p,p'-dinitrobenzophenone.
EXAMPLE E
Into a three-liter, three-necked, round-bottomed flask, equipped with a mechanical stirrer, thermowell and an addition funnel, there was added 2550 grams of 85 weight percent of aqueous nitric acid (1610 milliliters of 90 weight percent aqueous nitric acid and 140 milliliters of water), which was then cooled to about 5° to 10° C. To the stirred autoclave there was gradually added 280 grams of 1,1-diphenylethane over a period of 2.5 hours while maintaining the temperature of the mixture during the addition at about 10° C. After the addition was complete, the mixture was permitted to warm up to about 25° C. and stirred for 30 minutes. The mixture was then poured over ice water and extracted with toluene. The organic layer so obtained was washed successively with 500 milliliters of water, 500 milliliters of five weight percent aqueous sodium hydroxide and then with 500 milliliters of water. The resulting product, a nitrated diphenylethane, was dried by contact with magnesium sulfate, filtered, and the filtrate taken to dryness in a rotary evaporator, resulting in 389 grams of a dark red oil, which was partially crystalline.
A total of 135 grams of the nitrated diphenylethane obtained above was charged into a one liter, 316-stainless steel autoclave, followed by 200 grams of water. The autoclave was heated to 170° C. and, while maintaining this temperature, 170 milliliters of 70 percent aqueous nitric acid was added thereto over a period of 1.5 hours. When the addition of acid was completed, the reaction mixture was maintained at this temperature for 0.5 hour, at the end of which time the pressure was 450 pounds per square inch gauge (3.1 MPa). On cooling to about 25° C., followed by filtration, a total of 111 grams of yellow solids were obtained, amounting to a yield of 82.2 percent. Analysis of the product by HPLC showed the following: 57.9 weight percent p,p'-dinitrobenzophenone, 13.3 weight percent m,p'-dinitrobenzophenone, 25 weight percent o,p'-dinitrobenzophenone, 3.0 weight percent o,m'-dinitrobenzophenone and 0.8 weight percent o,o'-dinitrobenzophenone.
EXAMPLE F
A total of 55.7 grams of p-nitrobenzoyl chloride was dissolved in 225 milliliters of benzene and, while stirring, 65 grams of anhydrous aluminum chloride was added thereto over a period of 40 minutes, all of which was done under a nitrogen atmosphere. After addition was completed, the mixture was stirred for 30 minutes on a steam bath and then poured over ice. Extraction of the resulting product with methylene chloride, followed by washing the organic layer with water, drying with anhydrous magnesium sulfate and filtering, resulted in the recovery of 62.2 grams of p-nitrobenzophenone.
A total of 10 grams of p-nitrobenzophenone was dissolved in 50 milliliters of oleum containing 20 weight percent sulfur trioxide and then nitrated with a mixture containing 3.2 grams of 90 percent aqueous nitric acid and 15 grams of oleum containing 20 weight percent sulfur trioxide for 45 minutes at 15° C. The product was worked up, as before, and had the following composition: 84.1 weight percent m,p'-dinitrobenzophenone, 3.6 weight percent p,p'-dinitrobenzophenone and 12.3 weight percent o,p'-dinitrobenzophenone.
EXAMPLE G
The run of Example E was repeated but wherein 1,1-diphenylmethane was employed in place of 1,1-diphenylethane. On workup a 90 percent yield of a dinitrodiphenylmethane product was obtained.
This product was oxidized following the procedure of Example E to obtain an 85 percent yield of dinitrobenzophenones analyzing as follows: 44.9 weight percent p,p'-dinitrobenzophenone, 11.3 weight percent m,p'-dinitrobenzophenone, 31.0 weight percent o,p'-dinitrobenzophenone, 6.1 weight percent o,m'-dinitrobenzophenone and 6.1 weight percent o,o'-dinitrobenzophenone.
EXAMPLE H
Five grams of p-chlorobenzophenone was added, while stirring, to 50 milliliters of 90 percent aqueous nitric acid, while being maintained at 10° C. The mixture was permitted to come to room temperature (25° C.) and was left standing for 16 hours. The mixture was then poured over ice, filtered, washed with water until neutral, resulting in 6.0 grams of product. Analysis of the product by HPLC showed the following: 62.2 weight percent m-nitro-p'-chlorobenzophenone, 8.3 weight percent p-nitro-p'-chlorobenzophenone and 29.5 weight percent o-nitro-p'-chloro-benzophenone.
EXAMPLE I
A two-liter flask equipped with a mechanical stirrer and thermometer was charged with 250 grams of benzoin and 930 milliliters of acetic anhydride. After cooling to 15° C., 400 milliliters of concentrated sulfuric acid was added dropwise thereto while maintaining the temperature at about 30° C. The flask was cooled to -20° C. and 60 milliliters of 90 weight percent aqueous nitric acid was added at a rate to maintain the temperature of the flask between about -20° and -10° C. After the addition was complete the mixture was allowed to come to about 25° C. and stand overnight. No crystals formed, even when a seed crystal was added thereto. The mixture was poured into about 450 grams of ice water, and the aqueous portion was decanted from the gummy solid which was washed twice, each time with 500 milliliters of water. The solid recrystallized once from an equal volume of methanol and a second time from two volumes of methanol. Analysis by gas chromatography showed the material to be about 90 percent pure at this point. The solids were then slurried with an equal volume of methanol and filtered hot (50° C.). Air drying resulted in 577 grams of a white solid having a melting point to 124° to 126° C. and better than 98 percent pure p-nitrobenzoin acetate. From the filtrate a second crop of product was obtained analyzing by HPLC as follows: 36.8 weight percent p-nitro, 5.7 weight percent m-nitro and 57.5 weight percent o-nitro benzoin acetates. Thirty grams of the second crop obtained above was added to 100 milliliters of 70 weight percent aqueous nitric acid and heated at 70° C. for one hour. The reaction mixture was cooled to about 25° C. and then poured over 300 grams of an ice water mixture. After extraction with 300 milliliters of methylene chloride, washing the organic layer with 300 milliliters of water, drying over magnesium sulfate and filtration, followed by evaporation of the filtrate to dryness, afforded 24.1 grams of a yellow product. Analysis by gas liquid chromatography showed the following: 55 weight percent of o-nitrobenzil, 6.4 weight percent m-nitrobenzil and 38.6 p-nitrobenzil.
Each of the product mixtures obtained above, as well as two blends, was mixed while stirring with sulfuric acid or oleum for selected periods of time at selected temperature levels. The treated materials were then quenched by pouring over ice and filtered or extracted. The recovered products were washed successively with water, 10 weight percent aqueous sodium hydroxide and water and then dried and analyzed by HPLC. The data obtained are summarized below in Table I.
TABLE I__________________________________________________________________________ Source of Grams WeightEx- Material of Such Percent Productam- Being Material H.sub.2 SO.sub.4, SO.sub.3, SO.sub.3 In Temp., Time, Recovered, Isomer Distribution, Weight Percentple Treated Treated Grams Grams H.sub.2 SO.sub.4 °C. Hrs. Grams o,o' o,m' o,p' m,m' m,p' p,p'__________________________________________________________________________I A 10 92 0 0 70 0.5 * Initial 0 5.0 0 89.1 5.9 0 Final 0 5.0 0 89.1 5.9 0II A 10 92 0 0 100 0.5 9.4 Initial 0 5.0 0 89.1 5.9 0 Final 0 5.2 0 89.0 5.8 0III A 50 160 40 20 70 1.0 45 Initial 0 5.0 0 89.1 5.9 0 Final 0 0 0 93.6 6.4 0IV B 50 160 40 20 70 0.5 * Initial 7.9 29.7 0 44.4 17.2 0.8 Final 0 0 0 67.7 30.0 2.3V B 50 170 30 15 70 0.5 29.0 Initial 7.9 29.7 0 44.4 17.2 0.8 Final 0 0 0 69.5 30.5 0VI C 50 170 30 15 70 1.0 * Initial 2.5 20.6 0 65.2 11.7 <0 Final 0 0 0 85.0 15.0 0VII D 30 570 30 5 90 1.0 25.5 Initial 1.6 17.0 0 71.5 10.0 1.0 Final 0 14.7 0 77.3 8.0 0VIII E 50 323 57 15 70 1.0 31.1 Initial 0.8 3.0 25.0 0 13.3 57.9 Final 0 0 0 0 18.3 81.7IX F 12 100 16 14 70 0.5 * Initial 0 0 12.3 0 84.1 3.6 Final 0 0 0.5 0 95.5 4.0X F 12 100 16 14 70 1.0 10.5 Initial 0 0 12.3 0 84.1 3.6 Final 0 0 0 0 96.0 4.0XI G 50 323 57 15 70 1.0 * Initial 6.1 6.1 31.0 0 11.3 44.9 Final 0 0 0 0 19.9 80.1__________________________________________________________________________ Source of Grams Weight Material of such Percent Product Isomer Distribution, Being Material H.sub.2 SO.sub.4, SO.sub.3, SO.sub.3 In Temp., Time, Recovered, Weight PercentExample Treated Treated Grams Grams H.sub.2 SO.sub.4 °C. Hrs. Grams o m p__________________________________________________________________________XII H 6 45.6 11.4 20 70 0.1 2.7 Initial 29.5 62.2 8.3 Final 0 88.0 12.0XIII I 2.6 40.5 4.5 10 50 0.3 * Initial 55.0 6.4 38.6 Final 0 10.5 89.5XIV Blend of 10 80 20 20 70 1.0 5.1 Initial 40.0 60.0 0 Mononitro- Final 0 100 0 benzophenonesXV Blend of 10 80 20 20 25 1.0 6.7 Initial 20.0 70.0 10.0 Nitroaceto- Final 0 89.8 10.2 phenones__________________________________________________________________________ *Not determined.
The data in the above table clearly exemplifies the process defined and claimed herein. In each of Examples I and II, wherein the isomeric mixture was contacted solely with sulfuric acid, the ortho nitro aromatic ketone content thereof remained unchanged. However, when in each of the remaining examples the substrates containing various ortho nitro aromatic ketone compounds were contacted with oleum, as defined and claimed herein, the ortho nitro aromatic keto content thereof was substantially reduced, in most cases with the complete disappearance thereof.
Obviously, many modifications and variations of the invention, as hereinabove set forth, can be made without departing from the spirit and scope thereof and, therefore, only such limitations should be imposed as are indicated in the appended claims.
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A process for reducing the amount of ortho nitro aromatic keto compounds in a mixture containing the same which comprises contacting such mixture with oleum.
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TECHNICAL FIELD
[0001] The present invention relates generally to desensitizing fuel injector performance to internal component distortion, and more particularly to a solenoid carrier assembly that includes a deflection cavity to desensitize solenoid armature air gap to distortion in the fuel injector component stack.
BACKGROUND
[0002] Engineers are constantly seeking ways to improve fuel injector performance in order to accomplish various goals, such as reducing undesirable engine exhaust emissions. One strategy that has been adopted in this regard is the use of a hydraulic direct control needle valve to open and close the nozzle outlets of the fuel injector. In such fuel injectors, a needle control valve is moveable between positions that either expose a closing hydraulic surface on a needle valve member to high pressure or low pressure. While this innovation has greatly improved the ability to electronically control fuel injection characteristics, there remains room for improvement.
[0003] One area in need of potential improvement relates to the response time of the direct control needle valve to an electrically actuated needle control valve. Among other things, the response time can be improved if the volume of the needle control chamber, which applies either high or low pressure to the closing hydraulic surface of the needle valve, can be reduced. One strategy for accomplishing this goal is to locate the needle control valve and its associated electrical actuator deep inside the fuel injector in close proximity to the direct control needle valve. Another potential strategy for reducing response time is to reduce the travel distance of the needle control valve member, which acts as a pressure switch in exposing the closing hydraulic surface of the direct control needle valve to either high pressure or low pressure. While these two strategies appear to have promise, their implementation can potentially introduce new problems.
[0004] In one class of directly controlled fuel injectors, a solenoid is the chosen type of electrical actuator to control movement of the needle control valve. In order for these relatively small fast moving electrically actuated valves to behave predictably, the armature air gap should be known in order to produce predictable results. In order for the valve to perform in a manner consistent with other valves produced in mass production, the air gap should be uniform among valves in order to insure consistent performance in one fuel injector compared to another. These issues are further complicated by the fact that the armature air gap should be relatively small in order to extract the maximum performance from the interaction between the solenoid coil and stator relative to the armature. Furthermore, because the needle control valve wants to be located in close proximity to the direct control needle valve, it might have to be located under a distortion region within the fuel injector, which relates to the area underneath a plunger within a fuel injector. In other words, each time a plunger reciprocates within a fuel injector, fuel is raised to extremely high injection pressure levels. In turn, these pressure forces cause some measurable amount of distortion within the fuel injector. While these distortions are relatively small in magnitude, they can approach a magnitude that is on the same order as an armature air gap tolerance. Thus, in some situations it is possible for component distortion within a fuel injector to cyclically alter the needle control valve's armature air gap to the point that it briefly distorts the armature air gap out of acceptable geometrical tolerances. As such, the predictability of performance is undermined, and the variability in distortion from one fuel injector to another undermines the ability to mass produce valves that behave consistently between different fuel injectors.
[0005] Another potential problem introduced by locating an electrically actuated needle control valve in close proximity to the direct control needle valve relates to packaging considerations. In other words, the act of locating the needle control valve deep within the fuel injector further pressures packaging considerations that insure that all of the various fuel injector performance functions and structure can be packaged in an available envelope of space.
[0006] One potential strategy for desensitizing injector performance to geometrical distortions taking place within the fuel injector is to employ a two way valve as the needle control valve instead of a three way valve. In the case of a two way valve such as that shown in Heavy Duty Diesel Engines—The Potential of Injection Rate Shaping for Optimizing Emissions and Fuel Consumption”, presented by Messrs. Bernd Mahr, Manfred Dürnholz, Wilhelm Polach, and Hermann Grieshaber, Robert Bosch GmbH, Stuttgart, Germany, at the 21st International Engine Symposium, May 4-5, 2000, Vienna, Austria. The control valve member merely moves into and out of contact with a single seat, rather than moving between two seats as in the case of a three way valve. While such a two way valve strategy can potential assist in desensitizing fuel injector performance to component distortion, it necessarily suffers from other draw backs rendering it less than desirable. For instance, a two way valve strategy inherently results in substantial wastage of high pressure fuel since the fuel injector is controlled by opening its high pressure fuel passage directly to a low pressure drain during injection events. Even when flow restrictions are placed in the control passageways, the amount of fuel spilling leakage can be so substantial as to undermine the overall efficiency of the fuel injection system.
[0007] The present invention is directed to one or more of the problems set forth above.
SUMMARY OF THE INVENTION
[0008] In one aspect, a solenoid carrier assembly includes a carrier with a top surface separated from a bottom surface by a side surface. A stator assembly is attached to the carrier and includes an exposed bottom surface. A deflection cavity is disposed in the carrier between the top surface of the carrier and the stator assembly.
[0009] In another aspect, a fuel injector includes a plurality of stacked components, which include a solenoid carrier assembly positioned between a barrel and a needle valve. The solenoid carrier assembly includes a deflection cavity disposed in the solenoid carrier assembly between its top surface and a stator assembly. The deflection cavity is located underneath a plunger bore disposed in the barrel.
[0010] In still another aspect, a method of desensitizing armature air gap to component distortion in a fuel injector includes a step of assembling a stator assembly to a carrier, which has a distortion region. The distortion region is separated from a portion of a top surface of the stator assembly with a deflection cavity. The bottom surface of the carrier and the bottom surface of the stator assembly are made flush.
[0011] In another aspect, a carrier assembly includes a stator assembly attached to a carrier. The carrier includes a ball valve seat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] [0012]FIG. 1 is a front sectioned diagrammatic view of a fuel injector according to the present invention;
[0013] [0013]FIG. 2 is a sectioned side diagrammatic view of the fuel injector of FIG. 1;
[0014] [0014]FIG. 3 is a sectioned side view of the needle control valve assembly from the fuel injector of FIGS. 1 and 2;
[0015] [0015]FIG. 4 is an isometric view of a stator assembly according to one aspect of the present invention;
[0016] [0016]FIG. 5 is a top view of the stator assembly of FIG. 4;
[0017] [0017]FIG. 6 is a sectioned view of the stator assembly of FIG. 5 as viewed along section line A-A;
[0018] [0018]FIG. 7 is a sectioned view of the stator assembly of FIG. 5 as viewed along section line B-B; and
[0019] [0019]FIG. 8 is a bottom view of the stator assembly of FIGS. 4 and 5.
DETAILED DESCRIPTION
[0020] Referring to FIGS. 1 and 2, a fuel injector 14 includes an injector body 21 that can be thought of as including an upper portion 26 and a lower portion 28 . Fuel injector 14 can also be thought of as being divided between fuel pressurization assembly 27 and a direct control nozzle assembly 29 . In the fuel injector 14 illustrated, fuel pressurization assembly 27 is located in upper portion 26 , whereas direct control nozzle assembly 27 is located in lower portion 28 . Although the fuel injector 14 shows the fuel pressurization assembly 27 and the direct control nozzle assembly 29 joined into a unit injector 14 , those skilled in the art will appreciate that those respective assemblies could be located in separate bodies connected to one another with appropriate plumbing. The fuel pressurization assembly 27 includes a pressure intensifier 30 and a flow control valve 34 , which is operably coupled to an electrical actuator 32 . Direct control nozzle assembly 29 includes a needle control valve assembly 36 that is operably coupled to an electrical actuator 38 , which is located in and attached to lower portion 28 . In addition, a direct control needle valve 39 is controlled in its opening and closing by needle control valve assembly 36 , and hence electrical actuator 38 . Pressurized oil enters injector body 21 through its top surface at actuation fluid inlet 20 , and used low pressure oil is recirculated back to a sump (not shown) via an actuation fluid drain 22 . Fuel is circulated among the lower portions 28 of fuel injectors 14 via fuel inlet 24 .
[0021] Pressure intensifier 30 includes a stepped top intensifier piston 42 and a plunger 44 , which is preferably a free floating plunger. Intensifier piston 42 is biased to its retracted position, as shown, by a return spring 43 . The stepped top of intensifier piston 42 allows the initial movement rate, and hence possibly the initial injection rate, to be lower than that possible when the stepped top clears its counter bore. Return spring 43 is positioned in a piston return cavity 46 , which is vented directly to the area underneath the engine's valve cover via an unobstructed vent passage 47 . Piston 42 and plunger 44 move in barrel 31 , which is located near the top of the component stack 19 . Free floating plunger 44 is biased into contact with the underside of intensifier piston 42 via low pressure fuel acting on one end in fuel pressurization chamber 50 . Plunger 44 preferably has a convex end in contact with the underside of intensifier piston 42 to lessen the effects of a possible misalignment. In addition, plunger 44 is preferably symmetrical about three orthogonal axes such that fuel injector 14 can be more easily assembled by inserting either end of plunger 44 into the plunger bore located within injector body 21 . When intensifier piston 30 is undergoing its downward pumping stroke, fuel within fuel pressurization chamber 50 is raised to injection pressure levels. Any fuel that migrates up the side of plunger 44 is preferably channeled back for recirculation via a plunger vent annulus and a vent passage 52 . Pressure intensifier 30 is driven downward when flow control valve 32 connects actuation fluid passages 40 / 41 to high pressure actuation fluid inlet 20 . Between injection events, flow control valve 34 connects actuation fluid passages 40 / 41 to low pressure drain 22 allowing the intensifier 30 to retract toward its retracted position, as shown, via the action of return spring 33 and fuel pressure acting on the underside of plunger 44 . Thus, when pressure intensifier 30 is retracting, fresh fuel is pushed into fuel pressurization chamber 50 past check valve 53 via fuel inlet 24 . Check valve 53 includes carrier 102 having a ball valve seat 113 that is a distance away from top surface 103 that ball valve member 116 is below top surface 103 .
[0022] A flow control valve 34 includes an electrical actuator 32 , which in the illustrated embodiment is a solenoid, but could equally be any other suitable electrical actuator known in the art including, but not limited to, piezos, voice coils, etc. Flow control valve 34 includes a valve body that includes separate passages connected to actuation fluid inlet 20 , actuation fluid drain 22 and actuation fluid passages 40 / 41 , respectively. Flow control valve 34 includes a spool valve member biased via a biasing spring to a first position that fluidly connects actuation fluid passage 40 / 41 to actuation fluid drain 22 . When electrical actuator 32 is energized, a spool valve member moves away from the coil toward a second position. At this energized position, the spool valve member closes the fluid connection between actuation fluid passage 40 / 41 and drain 22 , and opens high pressure inlet 20 to actuation fluid passages 40 / 41 .
[0023] When pressure intensifier 30 is driven downward, high pressure fuel in fuel pressurization chamber 50 can flow via nozzle supply passage 67 to the nozzle chamber 65 , and out of nozzle outlets 64 if direct control needle valve 39 is in an open position. A portion of nozzle supply passage 67 extends between top surface 103 and bottom surface 104 of carrier 102 . A reverse flow valve member 117 is positioned in nozzle supply passage 67 adjacent top surface 103 , and acts to reduce penetration of combustion gases into fuel pressurization chamber 50 . When direct control needle valve 39 is in its closed position as shown, nozzle chamber 65 is blocked from fluid communication with nozzle outlets 64 . Direct control needle valve 39 includes a needle valve member made up of a needle portion 72 separated from a piston portion 69 by a lift spacer 66 . Thus, the needle valve member in this embodiment is made up of several components for ease of manufacturability and assembly, but could also be manufactured from a single solid piece. The needle valve member includes an opening hydraulic surface 63 exposed to fluid pressure in nozzle chamber 65 and a closing hydraulic surface 61 exposed to fluid pressure in a needle control chamber 60 . The thickness of lift spacer 66 preferably determines the maximum opening travel distance of direct control needle valve 39 . The direct control needle valve 39 is biased toward its downward closed position, as shown, by a biasing spring 62 that is compressed between lift spacer 66 and a VOP (valve opening pressure) spacer 68 . Thus, the valve opening pressure of the direct control valve 39 can be trimmed at time of manufacture by choosing an appropriate thickness for VOP spacer 68 .
[0024] A needle control chamber 60 is fluidly connected to either low pressure fuel inlet 24 or to nozzle supply passage 67 depending upon the positioning of needle control valve assembly 36 . When needle control chamber 60 is fluidly connected to nozzle supply passage 67 , direct control needle valve 39 will remain in, or move toward, its closed position, as shown, under the action of fluid pressure forces on closing hydraulic surface 61 and the spring force from biasing spring 62 . When needle control chamber 60 is fluidly connected to fuel inlet 24 , while nozzle passage 67 and hence nozzle chamber 65 are above a valve opening pressure, the fluid forces acting on opening hydraulic surface 63 are sufficient to lift the direct control needle valve 39 upward towards its open position against the action of biasing spring 62 to open nozzle outlets 64 .
[0025] Referring in addition to FIGS. 3 and 4, the inner workings of needle control valve 36 are illustrated. Valve assembly 36 includes a carrier assembly 74 which defines a portion of nozzle supply passage 67 , a connection passage 70 , a low pressure passage 71 and a needle control passage 59 . The valve assembly 36 is a two position three way valve that includes a needle control valve member 89 that is moveable between contact with a high pressure seat 94 and a low pressure seat 95 . Depending upon the position of valve member 89 , needle control passage 59 , which is fluidly connected to needle control chamber 60 (FIGS. 1 and 2), is fluidly connected to nozzle supply passage 67 via connection passage 70 or to fuel inlet 24 via low pressure passage 71 . Needle control valve assembly 36 includes a second electrical actuator 38 which in the illustrated embodiment is a stator assembly 37 , but could also be another type of electrical actuator, such as a piezo, a voice coil, etc. The stator assembly 37 includes a stator 90 , a coil 92 and a pair of female electrical socket connectors 57 that are electrically connected to coil 92 . Stator assembly 37 is attached to carrier 102 to produce a carrier assembly 74 . The female electrical socket connection 57 , which could instead be male, opens through top surface 103 and permits an electrical extension 56 to mate with stator assembly 37 within injector body 21 while providing exposed terminals for insulated conductors 55 outside of upper portion 26 . As illustrated, the socket connection is preferably oriented at a small angle, greater than zero, with respect to centerline 18 . Valve member 89 is biased downward to close low pressure seat 95 by a biasing spring 91 via an armature 93 that is attached to valve member 89 . When coil 81 is energized, armature 93 is lifted upward causing valve member 89 to open low pressure seat 95 and close high pressure seat 94 . Because the flow area is past seats 94 and 95 effect the performance of the fuel injector 14 , such as by effecting the opening and/or closing rate of direct control valve 29 , flow restrictions 96 and 97 are included. In particular, flow restriction 96 , which is preferably manufactured in a valve lift spacer 78 as a flow area that is restrictive relative to the flow area past seat 94 . Likewise, flow restriction orifice 97 preferably has a flow area that is restricted relative to the flow past low pressure seat 95 . Because these respective orifices 96 and 97 are based upon simple bore diameters rather than a clearance area between two separate moving parts, the performance between respective fuel injectors can be made more uniform. Furthermore, because these features are machined in a single valve lift spacer 78 , the manufacturability and assembly of needle control valve assembly 36 can be improved.
[0026] Referring in addition to FIGS. 5 - 8 , carrier assembly 74 includes a stator assembly 37 attached to a carrier 102 . Stator assembly 37 is preferably attached to carrier 102 by including adhesive along the cylindrical side bore that makes up cavity 106 . Stator assembly 37 is preferably advanced into cavity 106 until a peripheral raised portion 101 comes in contact with an internal surface 107 of carrier 102 . With this construction, a deflection cavity 100 is created between internal surface 107 and a majority of the top surface of stator assembly 37 . This deflection cavity is located directly beneath a deflection region 54 in carrier 102 , which itself is located underneath fuel pressurization chamber 50 , which forms a portion of the plunger bore (FIG. 2). When fuel is pressurized in fuel pressurization chamber 50 , distortion region 54 is highly stressed and deforms in the direction of fuel injector tip along centerline 18 . Preferably, the height of raised portion(s) 101 is preferably substantially larger than the expected deformation of region 54 . Raised portion 101 is preferably a flat topped ridge arranged in circular pattern. Those skilled in the art will recognize that raised portion 101 could be located on surface 107 of carrier 102 . In this way, any distortion in distortion region 54 changes the shape of deflection cavity 100 without causing substantial deformations to occur in stator assembly 37 . This in turn prevents the distortion occurring above from substantially altering the air gap 79 that exists between armature 93 and the bottom surface 111 of stator assembly 37 .
[0027] Other features that help maintain air gap 79 include a desirability in having the bottom surface 111 of stator assembly 37 about flush with the bottom surface 104 of carrier 102 . When this feature is combined with an air gap spacer 75 that contacts both bottom surfaces 104 and 111 as shown in FIG. 3, the compressive forces acting on raised portion 101 are transmitted downward along the peripheral portion of stator assembly 37 to the air gap spacer 75 , and from there downward in the component stack 19 (FIG. 2).
[0028] In order to conserve space and reduce part count, carrier assembly 74 preferably includes other functional features, such as plumbing passages, so that it provides more functionality than merely acting as a support for the stator assembly 37 . In particular, carrier 102 includes a top surface 103 separated from a bottom surface 104 by a circumferential side surface 105 . Side surface 105 includes a pair of annular ridges 114 and 115 , between which fuel supply passage 112 opens. The clearance between ridges 114 and 115 with the inner surface of the casing component shown in FIGS. 1 and 2 provide for an edge filter 51 for fuel entering fuel injector 14 through fuel inlet 24 on its way to fuel pressurization chamber 50 . In order to prevent the back flow of fuel through fuel supply passage 112 , it includes a check valve 53 that seats in a conical valve seat 113 . Apart from this plumbing, carrier assembly 74 includes a portion of nozzle supply passage 67 , which extends between top surface 103 and bottom surface 104 .
INDUSTRIAL APPLICABILITY
[0029] Each engine cycle can be broken into an intake stroke, a compression stroke, a power stroke and an exhaust stroke. During each engine cycle, each fuel injector 14 has the ability to inject up to five or more discrete shots per engine cycle. While a majority of these injection events will take place at or near the transition from the compression to power strokes, injection events can take place at any timing during the engine cycle to produce any desirable effect. For instance, an additional small injection event elsewhere in the engine cycle might be useful in reducing undesirable emissions. During each engine cycle, a number of basic steps are performed to inject fuel, and each of those acts is performed at a timing and in a number to produce a variety of fuel injection sequences, which include one or more injection events.
[0030] Among the steps performed at least once each engine cycle in each portion of the injection system (e.g., fuel injector) for each engine cylinder is the step of positioning a needle control valve 36 in a position that fluidly connects the needle control chamber 60 to the fuel pressurization chamber 50 , and fluidly blocks the needle control chamber 60 to the low pressure passage 71 . In the illustrated embodiment, that is accomplished by biasing the needle control valve member 89 into contact to close low pressure seat 95 by a spring 91 . The valve member 89 could be biased in the other direction and operate in a manner opposite to that described with regard to the illustrated embodiment. In the illustrated embodiment, the previously described act is performed by a three way valve. With this configuration, the pressurization chamber 50 is only briefly connected to the fuel inlet 24 when the needle control valve member 89 is moving between low pressure seat 95 and the high pressure seat 94 . Between injection events when pressure in fuel pressurization chamber 50 is relatively low, very little leakage occurs past needle control valve assembly 36 . In addition, little leakage occurs during each injection event since the respective high pressure seat 94 is closed. When the needle control chamber 60 is fluidly connected to the fuel pressurization chamber 50 and blocked from the low pressure passage 71 , no fuel injection takes place. In other words, when that occurs, direct control needle valve 39 is preferably held in or moved toward its downward closed position, as shown.
[0031] Another act that is performed at least once during each engine cycle includes increasing fuel pressure within the fuel pressurization chamber at least in part by moving the flow control valve 34 to a first position. The first position described is preferably the position at which valve 34 opens actuation fluid inlet 20 to actuation fluid passage 40 / 41 . When this step is performed, high pressure actuation fluid bears down onto the intensifier piston 42 , which compresses fuel in fuel pressurization chamber 50 to injection levels.
[0032] Another act that is performed at least once each engine cycle, and in some cases many times per engine cycle, includes moving the needle control valve 36 to a second position that fluidly connects the needle control chamber 60 to the low pressure passage 71 , and fluidly blocks the needle control chamber 60 to the fuel pressurization chamber 50 . This act is accomplished at least in part by supplying electrical energy to direct control nozzle assembly 29 . In the illustrated example, that includes supplying electrical energy to terminals 55 located outside the upper portion of fuel injector 14 , and channeling that electricity via electrical socket connection 57 to electrical actuator 32 located in the lower portion 28 of the injector body 21 . When this occurs, needle control valve member 89 is lifted to close high pressure seat 94 such that needle control chamber 60 is fluidly connected to low pressure passage 71 . If fuel pressure in nozzle chamber 65 is above a valve opening pressure, the direct control needle valve 39 will move to, or stay in, an open position that fluidly connects fuel pressurization chamber 50 to nozzle outlet 64 via nozzle supply passage 67 . If fuel pressure is below a valve opening pressure, the direct control needle valve 39 will move toward, or stay in, its biased closed position due to the action of biasing spring 62 being the dominant force.
[0033] Another step that occurs at least once each engine cycle includes decreasing fuel pressure in the fuel pressurization chamber 50 at least in part by moving a flow control valve 34 to a position that fluidly connects the actuation fluid passage 40 / 41 to the actuation fluid drain 22 . In the illustrated embodiments, this is the act that allows the fuel injector 14 to reset itself for a subsequent injection sequence. When this step occurs, intensifier piston 42 and plunger 44 will retract upward toward their retracted positions as shown, under the respective actions of return spring 43 and fuel pressure in fuel pressurization chamber 50 . In the illustrated embodiment, this act is accomplished by ending electrical energy to actuator 32 in order to allow flow control valve 34 to return to its biased position that opens actuation fluid drain 22 .
[0034] Referring now to FIG. 3, the needle control valve assembly portion of the component stack 19 is constructed by first trapping valve member 89 between an upper seat component 76 and a lower seat component 77 , which are separated by a valve lift spacer 78 having a nominal thickness. Next, the valve travel distance is measured. If its travel distance deviates more than a predetermined amount from a predetermined desired travel distance, a valve lift spacer 78 having a slightly different thickness is chosen in order to cause valve member 89 to have the desired predetermined travel distance. Next, armature 93 is attached to one end of valve member 89 . Next, an armature air gap spacer 75 is positioned atop upper seat component 76 . A biasing spring 91 is placed on top of armature 93 . Finally, a carrier assembly 74 is positioned on top of air gap spacer 75 such that the bottom surfaces 111 and 104 of stator assembly 37 and carrier 102 , respectively, are in contact with the top surface of air gap spacer 75 . At this point, air gap 79 is measured, if the measured air gap deviates from a predetermined air gap by greater than an acceptable tolerance, an air gap spacer 75 having a different thickness is substituted in place. This substituted air gap spacer should be chosen to have a thickness that results in an air gap 79 having a predetermined magnitude. Thus, when manufacturing a large number of valves, air gap spacer 75 can be provided in a range of thicknesses in order to insure that all of the manufactured valves can be made to have consistently sized air gaps 79 .
[0035] Carrier assembly 74 is manufactured by first machining the various passageways 67 and 112 therethrough. In addition, cavity 106 is machined in a conventional manner. Next, a stator assembly 37 is preferably glued to the cylindrical surface that defines a portion of cavity 106 until raised portion 101 comes into contact with the undersurface 107 of carrier 102 . Some care should be taken to prevent an excessive amount of adhesive from finding its way into deflection cavity 100 during this attachment process. After stator assembly 37 is attached to carrier 102 , their bottom surfaces 104 and 111 are ground to be flush with one another and parallel to top surface 103 .
[0036] During an injection event, the downward movement of pressure intensifier 30 causes fuel pressure in pressurization chamber 50 to rise dramatically. This pressure in turn causes a downward distorting force on carrier assembly 74 in distortion region 54 . Preferably, the height of raised portion(s) 101 is preferably larger than the expected deformation of distortion region 54 into deflection cavity 100 . In this way, the distortion is not carried through to stator 90 in a way that could substantially alter air gap 79 . In the illustrated embodiment, raised portion 101 has a height on the order of about 100 microns, and the expected distortion of distortion region 54 is less than 100 microns across the complete operating range of fuel injector 14 .
[0037] Those skilled in the art will appreciate that various modifications could be made to the illustrated embodiment without departing from the intended scope of the present invention. Thus, those skilled in the art will appreciate the other aspects, objects and advantages of this invention can be obtained from a study of the drawings, the disclosure and the appended claims.
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Because of the relatively high pressures experienced within fuel injectors, several internal components can undergo substantial deformation each time fuel is pressurized to injection levels. In some instances, such as when a solenoid operated control valve is positioned near a distortion region, the internal distortion can cause a fuel injector to behave with less predictability, and can undermine consistency from one fuel injector to another, since distortion levels and affects therefrom are likely to vary substantially from one injector to another. In order to desensitize fuel injector performance to this internal distortion, a deflection cavity is disposed within the fuel injector between the distortion region and the needle valve of the fuel injector. This strategy finds particular applicability to needle control valves disposed deep within fuel injectors in order to control fluid pressure on a closing hydraulic surface of a direct control needle valve, which opens and closes the nozzle outlets.
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CONTINUING APPLICATION DATA
This application is a continuation of U.S. application Ser. No. 12/249,175, filed on Oct. 10, 2008, which claims priority to and the benefit of U.S. provisional application Ser. No. 60/978,887, filed on Oct. 10, 2007, both of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the aerosolized delivery of hypertonic saline (HS) and other osmolytes to provide overnight nasal hydration to patients with all forms of chronic obstructive pulmonary disease (COPD) over a long period of time. The present invention also relates to a device and apparatus with a sufficient reservoir to accomplish the same.
2. Description of the Background
The mucosal surfaces at the interface between the environment and the body have evolved a number of “innate defenses”, i.e., protective mechanisms. A principal form of such innate defense is to cleanse these surfaces with liquid. Typically, the quantity of the liquid layer on a mucosal surface reflects the balance between epithelial liquid secretion, often reflecting active anion (Cl ˜ and/or HCO 3 ) secretion coupled with water (and a cation counter-ion), and epithelial liquid absorption, often reflecting active Na + absorption, coupled with water and counter anion (Cl ˜ and/or HCO 3 ). Many diseases of mucosal surfaces are caused by too little protective liquid on those mucosal surfaces created by an imbalance between secretion (too little) and absorption (relatively too much). The defective salt transport processes that characterize these mucosal dysfunctions reside in the epithelial layer of the mucosal surface.
One approach to replenish the protective liquid layer on mucosal surfaces is to “re-balance” the system by blocking Na + channel and liquid absorption. The epithelial protein that mediates the rate-limiting step of Na + and liquid absorption is the epithelial Na + channel (ENaC). ENaC is positioned on the apical surface of the epithelium, i.e. the mucosal surface-environmental interface. Therefore, to inhibit ENaC mediated Na + and liquid absorption, an ENaC blocker of the amiloride class (which blocks from the extracellular domain of ENaC) must be delivered to the mucosal surface and, importantly, be maintained at this site, to achieve therapeutic utility. The present invention describes diseases characterized by too little liquid on mucosal surfaces and “topical” sodium channel blockers designed to exhibit the increased potency, reduced mucosal absorbtion, and slow dissociation (“unbinding” or detachment) from ENaC required for therapy of these diseases.
Chronic obstructive pulmonary diseases are characterized by dehydration of airway surfaces and the retention of mucous secretions in the lungs. Examples of such diseases include cystic fibrosis, chronic bronchitis, and primary or secondary ciliary dyskinesia. Such diseases affect approximately 15 million patients in the United States, and are the sixth leading cause of death. Other airway or pulmonary diseases characterized by the accumulation of retained mucous secretions include sinusitis (an inflammation of the paranasal sinuses associated with upper respiratory infection) and pneumonia.
U.S. Pat. No. 5,817,028 to Anderson describes a method for the provocation of air passage narrowing (for evaluating susceptibility to asthma) and/or the induction of sputum in subjects via the inhalation of mannitol. It is suggested that the same technique can be used to induce sputum and promote mucociliary clearance. Substances suggested include osmolytes such as sodium chloride, potassium chloride, mannitol and dextrose.
Chronic bronchitis (CB), including the most common lethal genetic form of chronic bronchitis, cystic fibrosis (CF), a disease that reflects the body's failure to clear mucus normally from the lungs, which ultimately produces chronic airways infection. In the normal lung, the primary defense against chronic intrapulmonary airways infection (chronic bronchitis) is mediated by the continuous clearance of mucus from bronchial airway surfaces. This function in health effectively removes from the lung potentially noxious toxins and pathogens. Recent data indicate that the initiating problem, i.e., the “basic defect,” in both CB and CF is the failure to clear mucus from airway surfaces. The failure to clear mucus reflects dehydration of airway surfaces that reflects an imbalance between the amount of liquid and mucin on airway surfaces. This “airway surface liquid” (ASL) is primarily composed of salt and water in proportions similar to plasma (i.e., isotonic). Mucin macromolecules organize into a well defined “mucus layer” which normally traps inhaled bacteria and is transported out of the lung via the actions of cilia which beat in a watery, low viscosity solution termed the “periciliary liquid” (PCL). In the disease state, there is an imbalance in the quantities of mucins (too much) and ASL (too little) on airway surfaces that produces airway surface dehydration. This dehydration leads to mucus concentration, reduction in the lubricant activity of the PCL, and a failure to clear mucus via ciliary activity to the mouth. The reduction in mechanical clearance of mucus from the lung leads to chronic airways inflammation and bacterial colonization of mucus adherent to airway surfaces. It is the chronic retention of bacteria, the failure of local antimicrobial substances to kill mucus-entrapped bacteria on a chronic basis, and the consequent chronic inflammatory responses of the body to this type of surface infection, that lead to the destruction of the lung in CB and CF.
The current afflicted population in the U.S. is 12,000,000 patients with the acquired (primarily from cigarette smoke exposure) form of chronic bronchitis and approximately 30,000 patients with the genetic form, cystic fibrosis. Approximately equal numbers of both populations are present in Europe. In Asia, there is little CF but the incidence of CB is high and, like the rest of the world, is increasing.
There is currently a large, unmet medical need for products that specifically treat CB and CF at the level of the basic defect that cause these diseases. The current therapies for chronic bronchitis and cystic fibrosis focus on treating the symptoms and/or the late effects of these diseases. Thus, for chronic bronchitis, fl-agonists, inhaled steroids, anti-cholinergic agents, and oral theophyllines and phosphodiesterase inhibitors are all in development. However, none of these drugs treat effectively the fundamental problem of the failure to clear mucus from the lung. Similarly, in cystic fibrosis, the same spectrum of pharmacologic agents is used. These strategies have been complemented by more recent strategies designed to clear the CF lung of the DNA (“Pulmozyme”; Genentech) that has been deposited in the lung by neutrophils that have futilely attempted to kill the bacteria that grow in adherent mucus masses and through the use of inhaled antibiotics (“TOBI”) designed to augment the lungs' own killing mechanisms to rid the adherent mucus plaques of bacteria. A general principle of the body is that if the initiating lesion is not treated, in this case mucus retention/obstruction, bacterial infections became chronic and increasingly refractory to antimicrobial therapy. Thus, a major unmet therapeutic need for both CB and CF lung diseases is an effective means of re-hydrating airway mucus (i.e., restoring/expanding the volume of the ASL) and promoting its clearance, with bacteria, from the lung.
The inhalation of osmolytes/osmolyte solutions, such as hypertonic saline (3-12% preferred embodiment 7%) has been demonstrated to be a safe and effective treatment for individuals with cystic fibrosis. Inhaled hypertonic saline improves mucus hydration and clearance, and is associated with improvements in lung function, as well as, a reduction in the number of infectious exacerbations over one year (Donaldson et al. N. Engl. J. Med. 354, 3, Jan. 19, 2006, pp. 241-250) and Elkins et al. (N. Engl. J. Med. 354, 3, Jan. 19, 2006, pp. 229-240).
A limitation of inhaled osmolytes to increase mucosal hydration is the durability of the therapeutic effect of the osmolytes. In cell based assays, the ability of the mucosal epithelium to efficiently absorb fluid results in the reversal of osmolyte-induced surface hydration. The relatively short therapeutic benefit of inhaled osmolytes can be overcome by increasing the number of treatments per day. For example, Donaldson et al. ( N. Engl. J. Med. 354, 3, Jan. 19, 2006, pp. 241-250) showed inhaling 7% HS four times daily increased FEV1 by two fold greater than observed by Elkins et al. ( N. Engl. J. Med. 354, 3, Jan. 19, 2006, pp. 229-240) in CF patients inhaling 7% HS twice daily. However, increasing the dosing frequency of hypertonic saline or other osmolytes is inconvenient for subjects in need thereof, requiring hours of time taking medications during the day.
Clearly, what are needed are treatments that are more effective at restoring the clearance of mucus from the lungs of patients with CB/CF. The value of these new therapies will be reflected in improvements in the quality and duration of life for both the CF and the CB populations.
In U.S. patent application Ser. No. 11/851,803, R. C. Boucher and M. R. Johnson describe a method to extend the duration of osmolyte therapy by co-administering a potent sodium channel blockers. The inhibition of epithelial sodium transport prevents the reabsorption of HS osmolytes, and thereby, slows mucosal fluid absorption and extends the duration of mucosal hydration. The present invention describes an alternative approach to improving both the therapeutic benefit and convenience to the of inhaled osmolyte treatments.
SUMMARY OF THE INVENTION
The present invention is designed to improve the dosing of an osmolyte (e.g., HS) delivered to the lungs of subjects in need of airway surface rehydration by delivering the osmolyte to the lung via nasal cannulae. The present invention will permit subjects to be treated for long periods of time (e.g., hours) while sleeping or performing daily activities.
Thus, an object of the present invention is a method of treating chronic obstructive pulmonary disease by administering an effective amount of an aerosolized osmolyte to a subject in need thereof with a nebulizer connected to a nasal cannula.
Another object of the present invention is a nasal cannula system for delivering an osmolyte, comprising:
a nebulizer and
tubing, where one end of the tubing is connected to the nebulizer and another end of the tubing is tapered to fit in the nostril of a subject.
A more complete appreciation of the invention and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following FIGURE and detailed description.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 : Example of a nebulizer device capable of delivering osmolytes for extended periods of time. The diagram shows a standard large volume nebulizer (with >100 ml capacity) connected to a nasal cannula with heated tubing.
DETAILED DESCRIPTION OF THE INVENTION
Osmolytes are well-known therapeutics in the field of respiratory therapeutics. These agents are molecules or compounds that are osmotically active (i.e., are “osmolytes”). “Osmotically active” compounds of the present invention are membrane-impermeable (i.e., essentially non-absorbable) on the airway or pulmonary epithelial surface. The terms “airway surface” and “pulmonary surface,” as used herein, include pulmonary airway surfaces such as the bronchi and bronchioles, alveolar surfaces, and nasal and sinus surfaces. Active compounds of the present invention may be ionic osmolytes (i.e., salts), or may be non-ionic osmolytes (i.e., sugars, sugar alcohols, and organic osmolytes). It is specifically intended that both racemic forms of the active compounds that are racemic in nature are included in the group of active compounds that are useful in the present invention. It is to be noted that all racemates, enantiomers, diastereomers, tautomers, polymorphs and pseudopolymorphs and racemic mixtures of the osmotically active compounds are embraced by the present invention.
Active osmolytes useful in the present invention that are ionic osmolytes include any salt of a pharmaceutically acceptable anion and a pharmaceutically acceptable cation. Preferably, either (or both) of the anion and cation are non-absorbable (i.e., osmotically active and not subject to rapid active transport) in relation to the airway surfaces to which they are administered. Such compounds include but are not limited to anions and cations that are contained in FDA approved commercially marketed salts, see, e.g., Remington: The Science and Practice of Pharmacy , Vol. 11, pg. 1457 (19 th Ed. 1995), incorporated herein by reference, and can be used in any combination including their conventional combinations.
Pharmaceutically acceptable osmotically active anions that can be used to carry out the present invention include, but are not limited to, acetate, benzenesulfonate, benzoate, bicarbonate, bitartrate, bromide, calcium edetate, camsylate (camphorsulfonate), carbonate, chloride, citrate, dihydrochloride, edetate, edisylate (1,2-ethanedisulfonate), estolate (lauryl sulfate), esylate (1,2-ethanedisulfonate), fumarate, gluceptate, gluconate, glutamate, glycollylarsanilate (p-glycollamidophenylarsonate), hexylresorcinate, hydrabamine (N,N′-Di(dehydroabietyl)ethylenediamine), hydrobromide, hydrochloride, hydroxynaphthoate, iodide, isethionate, lactate, lactobionate, malate, maleate, mandelate, mesylate, methylbromide, methylnitrate, methylsulfate, mucate, napsylate, nitrate, nitrite, pamoate (embonate), pantothenate, phosphate or diphosphate, polygalacturonate, salicylate, stearate, subacetate, succinate, sulfate, tannate, tartrate, teoclate (8-chlorotheophyllinate), triethiodide, bicarbonate, etc. Particularly preferred anions include chloride sulfate, nitrate, gluconate, iodide, bicarbonate, bromide, and phosphate.
Pharmaceutically acceptable cations that can be used to carry out the present invention include, but are not limited to, organic cations such as benzathine (N,N′-dibenzylethylenediamine), chloroprocaine, choline, diethanolamine, ethylenediamine, meglumine (N-methyl D-glucamine), procaine, D-lysine, L-lysine, D-arginine, L-arginine, triethylammonium, N-methyl D-glycerol, and the like. Particularly preferred organic cations are 3-carbon, 4-carbon, 5-carbon and 6-carbon organic cations. Metallic cations useful in the practice of the present invention include but are not limited to aluminum, calcium, lithium, magnesium, potassium, sodium, zinc, iron, ammonium, and the like. Particularly preferred cations include sodium, potassium, choline, lithium, meglumine, D-lysine, ammonium, magnesium, and calcium.
Specific examples of osmotically active salts that may be used with the sodium channel blockers described herein to carry out the present invention include, but are not limited to, sodium chloride, potassium chloride, choline chloride, choline iodide, lithium chloride, meglumine chloride, L-lysine chloride, D-lysine chloride, ammonium chloride, potassium sulfate, potassium nitrate, potassium gluconate, potassium iodide, ferric chloride, ferrous chloride, potassium bromide, etc. Either a single salt or a combination of different osmotically active salts may be used to carry out the present invention. Combinations of different salts are preferred. When different salts are used, one of the anion or cation may be the same among the differing salts.
Osmotically active compounds of the present invention also include non-ionic osmolytes such as sugars, sugar-alcohols, and organic osmolytes. Sugars and sugar-alcohols useful in the practice of the present invention include but are not limited to 3-carbon sugars (e.g., glycerol, dihydroxyacetone); 4-carbon sugars (e.g., both the D and L forms of erythrose, threose, and erythrulose); 5-carbon sugars (e.g., both the D and L forms of ribose, arabinose, xylose, lyxose, psicose, fructose, sorbose, and tagatose); and 6-carbon sugars (e.g., both the D- and L-forms of altose, allose, glucose, mannose, gulose, idose, galactose, and talose, and the D- and L-forms of allo-heptulose, allo-hepulose, gluco-heptulose, manno-heptulose, gulo-heptulose, ido-heptulose, galacto-heptulose, talo-heptulose). Additional sugars useful in the practice of the present invention include raffinose, raffinose series oligosaccharides, and stachyose. Both the D- and L-forms of the reduced form of each sugar/sugar alcohol useful in the present invention are also active compounds within the scope of the invention. For example, glucose, when reduced, becomes sorbitol; within the scope of the invention, sorbitol and other reduced forms of sugar/sugar alcohols (e.g., mannitol, dulcitol, arabitol) are accordingly active compounds of the present invention.
Osmotically active compounds of the present invention additionally include the family of non-ionic osmolytes termed “organic osmolytes.” The term “organic osmolytes” is generally used to refer to molecules used to control intracellular osmolality in the kidney. See e.g., J. S. Handler et al., Comp. Biochem. Physiol, 117, 301-306 (1997); M. Burg, Am. J. Physiol. 268, F983-F996 (1995), each incorporated herein by reference. Although the inventor does not wish to be bound to any particular theory of the invention, it appears that these organic osmolytes are useful in controlling extracellular volume on the airway/pulmonary surface. Organic osmolytes useful as active compounds in the present invention include but are not limited to three major classes of compounds: polyols (polyhydric alcohols), methylamines, and amino acids. The polyol organic osmolytes considered useful in the practice of this invention include, but are not limited to, inositol, myo-inositol, and sorbitol. The methylamine organic osmolytes useful in the practice of the invention include, but are not limited to, choline, betaine, carnitine (L-, D- and DL-forms), phosphorylcholine, lyso-phosphorylcholine, glycerophosphorylcholine, creatine, and creatine phosphate. The amino acid organic osmolytes of the invention include, but are not limited to, the D- and L-forms of glycine, alanine, glutamine, glutamate, aspartate, proline and taurine. Additional osmolytes useful in the practice of the invention include tihulose and sarcosine. Mammalian organic osmolytes are preferred, with human organic osmolytes being most preferred. However, certain organic osmolytes are of bacterial, yeast, and marine animal origin, and these compounds are also useful active compounds within the scope of the present invention.
Under certain circumstances, an osmolyte precursor may be administered to the subject. Accordingly, these compounds are also useful in the practice of the invention. The term “osmolyte precursor” as used herein refers to a compound which is converted into an osmolyte by a metabolic step, either catabolic or anabolic. The osmolyte precursors of this invention include, but are not limited to, glucose, glucose polymers, glycerol, choline, phosphatidylcholine, lyso-phosphatidylcholine and inorganic phosphates, which are precursors of polyols and methylamines. Precursors of amino acid osmolytes within the scope of this invention include proteins, peptides, and polyamino acids, which are hydrolyzed to yield osmolyte amino acids, and metabolic precursors which can be converted into osmolyte amino acids by a metabolic step such as transamination. For example, a precursor of the amino acid glutamine is poly-L-glutamine, and a precursor of glutamate is poly-L-glutamic acid.
Also included within the scope of this invention are chemically modified osmolytes or osmolyte precursors. Such chemical modifications involve linking to the osmolyte (or precursor) an additional chemical group which alters or enhances the effect of the osmolyte or osmolyte precursor (e.g., inhibits degradation of the osmolyte molecule). Such chemical modifications have been utilized with drugs or prodrugs and are known in the art. (See, for example, U.S. Pat. Nos. 4,479,932 and 4,540,564; Shek, E. et al., J. Med. Chem. 19:113-117 (1976); Bodor, N. et al., J. Pharm. Sci. 67:1045-1050 (1978); Bodor, N. et al., J. Med. Chem. 26:313-318 (1983); Bodor, N. et al., J. Pharm. Sci. 75:29-35 (1986), each incorporated herein by reference.
In general, osmotically active compounds of the present invention (both ionic and non-ionic) that do not promote, or in fact deter or retard bacterial growth, are preferred.
It is an object of the present invention to provide a nebulizer connected to a nasal cannula to deliver aerosolized osmolytes (e.g., HS) to subjects over long time intervals. The nebulizer will have the capacity for a large volume of osmolyte solution (up to 2 liters) and will produce aerosol particles in the respirable range (1-5 microns MMAD) at a rate that will produce good lung deposition and will be continuous, i.e. will not require refilling over long time periods (8-24 hrs). An example of such a nebulizer is the Westmed Heart High Output Nebulizer. A nasal cannula/tubing will be connected to the nebulizer by a tapered fitting. The tubing will have an inner diameter of ˜3-5 mm with a length of 2-4 meters. The end of the tubing may end in one or two tapered ends that fit into the nostrils, although face masks are alternatives.
Both nebulizers and nasal cannulas are well-known in the field of respiratory treatment. See Critical Care Medicine (Michael James Murray, American Society of Critical Care Anesthesiologists, Douglas B. Coursin, Ronald G. Pearl, Donald S. Prough), pp. 431 and 439-445. However, commercial nebulizers are generally designed to rapidly delivery therapeutic agents via the mouth or mask. Nasal cannulas are generally used to delivery oxygen (gasses) to the lungs through the nose. Nasal cannulas are preferred for the delivery of gasses as they are comfortable to wear for long periods of time. The adaptation of a nasal cannula on a nebulizer provides a novel means to deliver inhaled osmolytes that offers the following advantages. (1) The nasal cannula/nebulizer device is comfortable and can be worn for extended periods of time. (2) The device can deliver osmolytes for long periods of time, thus, increasing the therapeutic benefit of these treatments.
Due to the narrow diameter of oxygen tubing and nasal cannulas, the output from a nebulizer will lead to the deposition of aerosol on the inner surface of the tubing, leading to the “condensation” and accumulation of fluid droplets. Fluid inside the tubing can occlude the flow of aerosol inside the tubing, as well as, result droplets blowing out the nasal cannula that would “drown” the subject with boluses of liquid.
Several modifications improve the performance of the nasal cannula/nebulizer device to prevent fluid condensation on the inner surface of the tubing and nasal cannula. It is an object of the present invention to heat all the fittings, tubing, and/or the nasal cannula of the device to retard condensation in the tubing. Thus the heated, inner surface coated cannula will ensure that the aerosol generated will be delivered to the nostril as a respirable particle. It is another object of the present invention that the tubing will contain a coating on its inner surface so as to prevent condensation of solution in the lumen. It is anticipated that the subject will use the heated cannulae to receive HS for periods of minutes to daily.
EXAMPLES
The nebulizer system shown in FIG. 1 was run for 80 minutes with 7% hypertonic saline. The build-up of fluid within the oxygen tubing was observed with and without heating the oxygen tubing in a water bath. For this system, the tubing became occluded with water droplets within 23 minutes of continuous nebulizer operation. Externally heating the tubing to 60° C. allow the nebulizer system to run for the full 80 minutes without occlusion from water droplets.
TABLE 1
The effect of heating on fluid condensation within the oxygen tubing.
External
Tubing
Time to
Nebulizer/Compressor
Tubing
Temperature
Condensation
Pari-LC Star with
Oxygen Tubing with
Ambient
23 min
ProNeb Compressor
Adult nasal cannula
Pari-LC Star with
Oxygen Tubing with
60° C.
No significant
ProNeb Compressor
Adult nasal cannula
condensation
Obviously, numerous modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described herein.
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The invention described herein is directed to method of treating chronic obstructive pulmonary disease, comprising administering an effective amount of an osmolyte by at least one nasal cannula to a subject in need thereof. Also provided is a nasal cannula system for delivering an osmolyte, comprising a nebulizer and tubing having two ends, where the first end of the tubing is connected to the nebulizer and the second end of the tubing is tapered to fit in the nostril of a subject.
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BACKGROUND OF THE INVENTION
This invention relates to an automatic control device for earth working equipment.
When a grading or earth-pushing work is conducted with earth working equipment such as a bulldozer, it is necessary that the work is efficiently carried out without imposing overload to the vehicle body or the blade; however, in practice, it is difficult to do so.
In a conventional blade control method, a laser beam is emitted from a laser beam emitter set at a predetermined position of the vehicle, which has a reference height, and a laser beam receiver fixedly provided at a predetermined position of the blade or the like receives the laser beam thus emitted, thereby to obtain a height signal which is utilized to automatically control the height of the blade.
In another conventional blade control method, the bulldozer itself has a reference value, and the blade inclination angle is detected by means of a vertical gyroscope or an inclinometer, so that the blade height is automatically controlled in accordance with the difference between the detection value and the reference value.
However, the former method is disadvantageous in the following points: In a dusty place, or in a place where the ground vibrates, the laser beam is disturbed, and therefore the sufficient result cannot be obtained. In addition, the control device is considerably intricate, and accordingly, high in manufacturing cost.
The latter method is also disadvantageous in the following points: In the case where the vertical gyroscope is employed for the detection of the blade inclination angle, the vertical gyroscope itself is expensive, and is relatively low in durability against vibration. In the case where the inclinometer is employed, it is not expensive; however, it is affected by the acceleration and deceleration of the vehicle body. Therefore, when the vehicle speed is varied, it is impossible to control the blade.
In order to perform the blade control by detecting a load applied to the blade, a method is known in the art in which, for a wheel type vehicle such as motor grader or a motor scraper, the ratio in r.p.m. of the driving wheel to the driven wheel is detected to obtain a slip signal, which is utilized to control the vertical movement of the blade.
In this method, the detection is carried out after the load is increased to cause the driving wheel to slip. Therefore, the method is not applicable to a caterpillar type vehicle.
In the automatic blade control, the finish accuracy is greatly affected by the response speed. In the ordinary on-off control system, it is necessary to increase the dead zone to increase the response speed, but if the dead zone is increased, then hunting is caused. Therefore, in the ordinary on-off control system, the finish accuracy is lowered by increasing the response speed. Furthermore, in the ordinary on-off control system, it is necessary to decrease the response speed to increase the finish accuracy. Thus, the ordinary on-off control system suffers from the contradictory problem.
As is apparent from the above description, it is very difficult to automatically control the blade, and therefore almost all of earth working equipments such as bulldozers have no automatic blade control devices.
Accordingly, earth working operations such as those in pushing or leveling of earth are considerably difficult, and the operator must be highly skilled in the operation of the earth working equipment. As the working conditions are severe, the operator becomes considerably fatigued, which makes the work more difficult.
SUMMARY OF THE INVENTION
Accordingly, an object of this invention is to eliminate the above-described difficulties of the conventional blade control method.
It is another object of the invention to provide an automatic control device for an earth working equipment capable of controlling the blade with high accuracy without being affected by vibrations applied to the equipment.
It is another object of the invention to provide an automatic control device for an earth working equipment having two kinds of overload detection means and thereby being capable of detecting overload promptly.
It is still another object of the invention to provide an automatic control device for an earth working equipment capable of conducting a complex blade control by effectively performing a lifting and lowering control and a tilting control.
According to the invention, all of the blade height, the tilt angle, and the load reduction in the case of overload can be automatically controlled. Accordingly, it is unnecessary for the operator to have high operating technique, and the operator's fatigue can be reduced during the work. As two inclinometers are employed, the errors due to the acceleration caused at random can be eliminated, so that the inclination of the vehicle body can be accurately detected. Furthermore, the automatic control device is high in rigidity, high in accuracy, and low in manufacturing cost.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described with reference to the accompanying drawings, wherein:
FIG. 1 is a block diagram of the control system of the present invention;
FIG. 2 is a timing diagram showing the outputs of various components of the control system;
FIG. 3 is a block diagram of the acceleration compensation arithmetic circuit of FIG. 1;
FIG. 4 is a diagram of forces exerted on a pair of inclinometers which form a part of the present invention;
FIG. 5 is a block diagram of a Doppler overload control circuit used in the present invention;
FIG. 6 is a graph of the running characteristics of a bulldozer;
FIG. 7 is a block diagram of a circuit for generating frame inclination correction signals;
FIG. 8 is a block diagram of a timer circuit used to control the operation of the control system of the present invention;
FIG. 9 is a timing diagram showing the operation of the circuit of FIG. 8; and
FIG. 10 is a portion of the control circuitry which controls the interrelation between tilt and lift operations performed by the control system of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
One example of an automatic control device for earth working equipment according to this invention will be described with reference to the accompanying drawings in detail. For convenience in description, the earth working equipment is a bulldozer by way of example.
Referring to FIG. 1, a blade 4 is secured to the end of a blade supporting frame 3 the other end of which is rotatably supported on a body of a bulldozer 2. The blade 4 is moved up and down by a lift cylinder 5 disposed between the body and the blade supporting frame 3. The blade is tilted longitudinally by a tilt cylinder 6 provided between the blade 4 and the blade supporting frame 3. A direction switching valve 7 has four switching positions 7A through 7D to set the lift cylinder 5 to expanding, contracting, holding and floating positions. The valve 7 is connected through a rod 8 to the cylinder section 9a of an operating cylinder (hereinafter referred to as "a slave cylinder" when applicable) 9. The rod 9b of the slave cylinder 9 is connected to a manual operating lever 10. A lock mechanism 11 is to lock the operating lever 10 in the automatic blade control. The lock mechanism 11 is operated in association with a blade manual-automatic control change-over switch 50. That is, when the operating lever 10 is locked, the switch 50 is turned on; and when the operating lever 10 is released, the switch 50 is turned off. A three-position changeover electromagnetic valve 12 and a two-position change-over electromagnetic valve 13 (hereinafter referred to merely as "electromagnetic valves 12 and 13" when applicable) are provided to drive the slave cylinder 9. The electromagnetic valves 12 and 13 are connected to a hydraulic pressure circuit between the slave cylinder 9 and a hydraulic pressure pump 20, so that they are switched in response to output signals from a driver circuit 52. In the blade manual control, the valves 12 and 13 are switched to the positions 12C and 13A, respectively, as a result of which the slave cylinder 9 becomes hydraulically inoperative, i.e. oil is sealed in the cylinder 9 so that the cylinder 9 can be regarded as rigid body. The rod 8 follows movement of the rod 9b. Therefore, the operator can manually set the direction switching valve 7 to a predetermined switching position by using the operating lever 10.
In the automatic control operation, the operating lever 10 is locked by the lock mechanism 11, and accordingly the electromagnetic valve 12 expands or contracts the cylinder section 9a of the slave cylinder 9 with respect to the rod 9b according to the switching position 12A or 12B, thereby to set the direction siwtching valve 7 to a predetermined switching position. The electromagnetic valve 13 is provided for helping return of the direction siwtching valve 7 return by a spring. When the electromagnetic valve 13 is set to the position 13B, the bottom and head chamber thereof are communicated directly with a tank T 6 , so that the slave cylinder 9 can operate freely.
Another direction switching valve 14 has three positions 14A, 14B and 14C to control the tilt cylinder 6, and it is connected to the cylinder section 16a of another slave cylinder 16 through a rod 15. The rod 16b of the slave cylinder 16 is coupled to the operating lever 10.
Electromagnetic valves 17 and 18 are provided to drive the slave cylinder 16. These electromagnetic valves 17 and 18 are connected to a hydraulic pressure circuit between the slave cylinder 16 and a hydraulic pressure pump 20 and are switched in response to output signals from a driver circuit 53, similarly as in the above-described electromagnetic valves 12 and 13. In the blade manual control operation, the electromagnetic valves 17 and 18 are switched to the positions 17C and 18A, respectively, as a result of which the rod 15 follows movement of the rod 16b in the same manner as has previously been described with regard to the slave cylinder 9. Accordingly, the operator can switch the direction switching valve 14 to a predetermined position by using the operating lever 10. In the blade automatic control operation, similarly as in the electromagnetic valve 12, the electromagnetic valve 17 expands and contracts the cylinder section 16a of the slave cylinder 16 with respect to the rod 16b according to the positions 17A-17C. Similarly as in the electromagnetic valve 13, the electromagnetic valve 18 is provided to help return of the direction switching valve 14 by a spring. When the electromagnetic valve 18 is set to the position 18B, the slave cylinder 16 is allowed to operate freely. These electromagnetic valves 13 and 18 are normally at the positions 13A and 18A, respectively. The electromagnetic valves 13 and 18 are switched to the positions 13B and 18B, respectively, when control signals which are outputted by the logic circuits 35 and 48 with the predetermined timing are applied through valve drive circuits 52 and 53 to solenoids 13S and 18S to energize the latter, respectively.
Inclinometers 21 and 22 are mounted on the upper part and the lower part of the body and along a vertical line which is extended near the center of gravity of the body The inclinometers 21 and 22 output signals e a and e b in response to an inclination of the body, respectively. The output signals are applied to an acceleration compensation arithmetic circuit 25. These inclination signals e a and e b include noise signals which are caused by the acceleration of the bulldozer 2 when the bulldozer 2 is moved forwards backwards, started or stopped.
In the acceleration compensation arithmetic circuit 25, the input signals e a and e b are subjected to addition and subtraction to obtain an angular acceleration signal in the direction of advancement of the body and a body inclination angle signal, and the inclination angle signal is subjected to integration twice to obtain an inclination value. The difference between the inclination value thus obtained and the inclination angle signal is obtained. The difference is fed back to the integration, thereby to completely eliminate the effects of the acceleration caused at random. Thus, the circuit 25 outputs an inclination angle signal e d corresponding to inclination of the body.
The acceleration compensation arithmetic circuit 25 is illustrated in FIG. 3 in detail, which comprises addition circuits A 1 through A 4 , integration circuits IG 1 and IG 2 , an inverter IN 1 , and coefficient units C 1 and C 2 .
The inclinometers 21 and 22 are equal in construction, and have weights A and B, respectively. When the weights A and B are turned around the centers G of gravity in the direction of the arrow AR, when forces applied to the weights A and B are expressed by vectors as shown in FIG. 4. In FIG. 4, F 1 and F 2 are the forces applied to the weights to bend the latter, αx and αy are the components in the X and Y direction of the acceleration applied to each weight, and m is the mass of each weight.
If the spring constant of each of the inclinometers 21 and 22 is expressed by K, and the amount of bend of the springs of inclinometers 21 and 22 in balance are expressed by S 1 and S 2 , respectively, then ##EQU1##
The inclinometer 22 is near the center of gravity, and l/g is sufficiently small. Therefore the equation (4) can be rewritten in approximation as follows: ##EQU2##
(1/g) (αx cos θ+αy sin θ) is the combination of the acceleration component and the gravity acceleration component, and therefore it can be regarded as a noise component (Nx) with respect to the inclination angle to be obtained. ##EQU3## The inclinometers 21 and 22 output K/mL S 1 and K/mg S 2 as the electrical signals e a and e b . ##EQU4## The equation (7) is calculated by the addition circuit A 2 . The value θ is obtained by inverting the result of the calculation by the inverter IN 1 . This value is integrated twice to obtain the value. However, since integration error is caused in the integration operation, an arrangement has been made in the invention to correct the integration error. Furthermore, it goes without saying that correction is made to minimize the above-described noise component. Then, the calculation of the following equation (10) is carried out: ##EQU5## Therefore, θ is independent of K 1 and K 2 . In addition, the accumulation error in the integration can be substantially minimized. The value -(1/S) is the transfer function of the integrator.
With respect to the noise component (e b =Nx), the following calculation is carried out: ##EQU6## The transfer function of the equation (13) can be sufficiently reduced by suitably selecting the values K 1 and K 2 . That is, the effect of the noise component can be sufficiently reduced. Accordingly, the signal e d excellent in response characteristic and sufficiently free from the effect of the acceleration caused at random can be obtained.
A cylinder stroke detector 23 is juxtaposed with the blade cylinder 5, to detect the stroke of the blade cylinder 5 thereby to output a stroke signal e s .
An inclinometer 24 is provided at a predetermined position on the rear surface of the blade 4, to detect the tilt angle of the blade 4 to output a tilt angle signal e c .
An arithmetic circuit 26 receives the inclination angle signal e d of the body and the cylinder stroke signal e s , to calculate the inclination angle of the blade supporting frame 3 thereby to output the corresponding inclination angle signal eθ.
A frame inclination angle setter 28 is to set an inclination angle of the blade supporting frame 3, and outputs an inclination angle setting signal Eθ corresponding to the set angle.
A tilt angle setter 30 operates to set a tilt angle of the blade 4, and to output a tilt angle setting signal E c corresponding to the set angle.
A throttle lever opening degree detector 36 detects a throttle lever opening degree to output a signal Ep.
An engine speed detector 37 detects a speed of the engine (not shown) to output an engine speed signal En.
An arithmetic circuit 38 receives the signals Ep and En to calculate a blade load thereby to output a load signal e L .
A load setter 39 is to set a maximum load which can be applied to the bulldozer blade 4 according to working conditions, and it ouptuts a load setting signal E LO corresponding to the set load.
In an arithmetic circuit 40, the load signal e L is compared to the load setting signal E L0 , and when the signal e L exceeds the signal E L0 , i.e., when the blade 4 is overloaded, an overload signal E L1 corresponding to the overload is outputted to comparator 31.
In this invention, an overload control operation employing a Doppler radar can be effected by operating a switch S 1 . The overload control operation using the Dopper radar will be described.
The aforementioned Doppler radar 61 is provided on the bulldozer 2 in such a manner that its antenna forms a predetermined angle with a working surface. The Doppler radar 61 transmits a microwave to the working surface through the antenna and receives the reflected wave, thereby to output a frequency signal corresponding to the speed of the vehicle with respect to the ground. The frequency signal is applied through an amplifier 62 to a frequency-to-voltage converter circuit 63, where it is converted into a corresponding voltage signal. A critical speed setter 64 is to set the critical speed, that is, the lower limit value of speed at which the work can be carried out without causing failures such as slips or engine stops. During the earth working operation, as the blade 4 pushes earth, a large amount of earth is accumulated thereon, and accordingly the speed of the vehicle is reduced by the weight of the earth. If the vehicle is forcibly advanced under this condition, then the vehicle is overloaded, as a result of which the shoe slip or the engine stop is caused.
Therefore, in this invention, the lower limit of speed at which the work can be carried out without causing failures such as shoe slips and engine stops is set up by the critical speed setter 64 according to the qualities of soil and the running characteristics of the vehicle 2 for every using speed thereof. When the speed of the vehicle with respect to the ground falls below the critical speed during the work, it is determined that the vehicle is overloaded, so that the blade is lifted. Thus, the overload is eliminated before the failures occur.
One example of a method of determining the critical speed will be described.
Assume that the running characteristics of the bulldozer for its various speeds (the relation between the vehicle speeds and the traction forces) are as indicated in FIG. 6. In this example, it is considered that only at the first speed, the produced traction force exceeds the shoe slip limit, and at the other speeds no shoe slip is caused. Accordingly, for the first speed the above-described critical speed should be set to a speed (about 1.8 km/h in this example) slightly higher than the speed at which the shoe slip is caused, and for the second and third speeds it should be set to a speed slightly higher than the speed at which the engine stop is caused. However, taking the conditions into account that not only the engine stop should not be caused, but also the work should be conducted more efficiently, the critical speed for the second or third speed should be a speed at which the traction force is not greatly reduced and it is not greatly varied when the second or third speed is changed to the lower speed. More specifically, in the example shown in FIG. 6, the critical speed for the second speed should be a speed (about 2.3 km/h) at the intersection P 2 of the characteristic curve of the first speed and the characteristic curve of the second speed, and the critical speed for the third speed should be a speed (about 4.5 km/h) at the intersection P 3 of the characteristic curve of the second speed and the characteristic curve of the third speed. If the critical speeds are determined as described above, then not only can the work be done efficiently, but also the bulldozer is operated more economically. In other words, the work can be achieved with an improved fuel consumption rate by setting the critical speeds as described above, because the fuel consumption rate is worse with a speed at which the traction force is smaller, but is better with a speed at which the traction force is greater.
As the traction force at the shoe slip limit depends on the quality of soil, it is preferable that a necessary critical speed is determined for every work in advance by selecting a critical speed in a speed step exceeding the traction force.
The critical speed setter 64 may be one potentiometer. If, for the various speed steps, the corresponding ranges are marked on the speed scale (not shown) of the setter 64, then it is unnecessary to provide a potentiometer for every speed step; that is, it is possible to set up the critical speeds for all the speed steps with only one potentiometer.
A signal e 1 corresponding to the critical speed outputted by the critical speed setter 64 and a signal e 2 corresponding to the speed with respect the ground (hereinafter referred to as "a ground speed") outputted by the frequency-to-voltage conversion circuit 63 are applied to a comparator 60a in an arithmetic circuit 60 (FIG. 5). The comparator 60a outputs an overload signal e L when the ground speed becomes lower than the critical speed or the signal e 2 becomes smaller than the signal e 1 (e 2 <e 1 ), i.e., when the blade 4 is overloaded. After being subjected to integration in an integrator 60b, the overload signal e L is applied to a clipper circuit 60c, where its upper portion is cut at a predetermined level, and the resultant overload signal e OL is applied through a gate circuit 60d and the switch S 1 to a comparator 31.
A forward and backward detector 41 is a switch operated in association with the forward and reverse change lever, and outputs signals EF and ER respectively in the forward run and the backward run, these signals EF and ER being applied to a work mode change-over switch 42. The switch 42 operates to place the blade in "lift" state automatically when the bulldozer 2 is moved forward or reversely.
Now it is assumed that the operator has locked the manual operating lever 10 with the lock mechanism 11, as a result of which the change-over switch 50 is turned on, and the blade 4 of the bulldozer 2 is under the automatic control. Furthermore, assume that the bulldozer 2 is moved forward at a speed V. In addition, it is assumed that the output E of the inclination angle setter 28, the output E c of the tilt angle setter 30, the output e.sub.θ of the arithmetic circuit 26 and the output e c of the inclinometer 24 are maintained zero, and that the electromagnetic valves 13 and 18 are set to the positions 13A and 18A, respectively, and the direction switching valves 7 and 14 are set to the middle positions 7C and 14C, respectively, to hold the blade.
When the operator set the frame inclination setter 28 to, for instance, +3 degrees at the time instant t 0 , then the setter 28 outputs a signal E.sub.θ corresponding to +3 degrees. At this time instant, the signal e.sub.θ is at 0 degrees. Accordingly, the comparator 31 outputs a difference signal eδ corresponding to the difference between these two signals e.sub.θ and E.sub.θ, i.e., +3 degrees. This output is applied to a compensation unit 32. This compensation unit 32 delivers out a difference signal eδ' which is a sum of a signal obtained by proportionally calculating a signal eδ and a signal obtained by differentiating the signal eδ. The signal eδ' is applied to an absolute value circuit 70. The differentiation characteristic is given to the difference signal eδ' to improve the characteristic of the control system. The circuit 70 delivers out a signal eδ" which represents an absolute value of the input signal eδ'.
The pulse control circuit 34 receives the difference signal eδ", the engine speed signal E N and the output signal E T of an oil temperature detector 33, to output a pulse signal P (FIG. 2 (b)) having a suitable period T according to the signal E N and having a pulse width ΔT proportional to the signal eδ", EN,ET. The signal P is applied to the logic circuit 35. This pulse signal P is a spool position instruction signal for the direction switching valve 7.
There are considered many methods of converting the input signal eδ", E T and E N into the pulse signal P having the period T and the pulse width ΔT. However, in this case, the following method is employed by way of example. The difference signal eδ" will be expressed by ε(t) for instance.
First, an average pressurized oil flow rate Q supplied to the lift cylinder 5 when the spool of the direction switching valve 7 is operated by the pulse signal P having the period T and the pulse width ΔT will be roughly calculated. If an oil pressure pump 19 has its discharge quantity Q M , then the average pressurized oil flow rate Q can be expressed by the following equation (1); ##EQU7##
If the oil temperature changes, the flow rate Q also changes due to change in the speed of slave cylinder. This change can be considered to be change in ΔT in the equation (1) due to the temperature change. The equation (1) therefore is converted to ##EQU8##
Where f(th) is a function of the oil temperature whose function form is determined by characteristics of the cylinder, the operation valve and the oil. Correction of the change in the flow rate Q can be achieved by calculating f(th), measuring the oil temperature and changing ΔT so that ΔT becomes ##EQU9##
Assuming that the oil pressure pump 19 is driven by the engine and that the discharge quantity Q M varies in proportion to the engine revolution number N, the above equation (1) is expressed by the following equation (4) ##EQU10## where K 1 is a constant.
Accordingly, the pulse width ΔT can be corrected by a value obtained by detecting the engine revolution number N.
The comparator 34 outputs the pulse signal P (FIG. 2b) having period T and the pulse width ΔT proportional to the input signal.
The flow rate characteristic of the earth working equipment operation switching valve has a dead zone. If the speed or the idling time of the slave cylinder 9 is changed, then the flow rate in the lift cylinder 5 is changed even though the same pulse width signal is applied to the electromagnetic valve 12. The speed and the idling time of the slave cylinder 9 depend on the engine speed and the operating oil temperature. Therefore, the pulse width is corrected by applying the signals from the oil temperature detector 33 and an engine speed sensor 37 to comparator 34.
When the spool position instruction signal, i.e., the pulse width ΔT of the pulse signal P exceeds the dead zone signal E.sub.Δ of a dead zone setter 43, the logic circuit 35 outputs a control signal Esa to energize the solenoid 12Sa of the electromagnetic valve 12, thereby to set the latter 12 to the position 12B. As a result, the slave cylinder 9 moves the rod 8 in the direction of the arrow A, whereby the direction switching valve 7 is set to the position 7A. When the direction switching valve 7 is completely set to the position 7A, the logic circuit 35 turns off the control signal Esa to deenergize the solenoid 12Sa, whereby the electromagnetic valve 12 is set to the middle position. Thus, the slave cylinder 9 is held at that position, and the direction switching valve 7 is held at the spool position 7A. Accordingly, the lift cylinder 5, being supplied with the pressurized oil from the hydraulic pump 19, is contracted, whereupon the blade supporting frame 3 is turned upwardly to move the blade 4 upwardly.
The arithmetic circuit 26 outputs an inclination signal eθ according to the inclination of the blade supporting frame 3. This signal is applied to the comparator 31.
When the pulse signal P becomes to the zero level to make an instruction to hold the blade, then the logic circuit 35 outputs a control signal Esb to energize the solenoid 12Sb of the electromagnetic valve 12 thereby to set the latter 12 to the position 12A. Accordingly, the slave cylinder 9 is contracted to move the rod 8 in the direction of the arrow A', thereby to move the direction switching valve 7 towards the middle position 7C. Then, at the time instant when the direction switching valve 7 has been moved in the spool neutral direction for a predetermined period of time or as much as a predetermined distance, the driver circuit 52 sets the control signal Esb to the zero level, and simultaneously outputs a control signal Esc to energize the solenoid 13S of the electromagnetic valve 13, thereby to set the latter to the position 13B. Accordingly, no pressurized oil is supplied to the slave cylinder 9, and simultaneously the bottom chamber and the head chamber are connected directly to the tank T 6 by the electromagnetic valve 13, as a result of which the slave cylinder 9 is set free. Therefore, the direction switching valve 7 can returned exactly to the middle position 7C by the restoring force of the return spring. When the direction siwtching valve 7 has returned to its middle position 7C, the logic circuit 35 and the driver circuit 52 sets the control signal Esc to the zero level to deenergize the solenoid 13S, thereby to set the electromagnetic valve 13 to the position 13A. Accordingly, the salve cylinder 9 is held at the position, and the direction switching valve 7 is locked at the middle position 7C. Thus, the blade is held at that position.
The blade 4 is gradually lifted by repeatedly carrying out the above-described controls in succession. When the inclination angle of the blade supporting frame 3 reaches the preset angle +3 degrees, then the difference signal eδ from the comparator 31 become the zero level, and the control system is placed in stable state. Thus, the control of moving the blade 4 upwardly has been accomplished.
If the load of the blade 4 is increased and the arithmetic circuit 40 or 60 outputs the overload signal E L1 or E L2 during the earth working operation which is conducted while the blade 4 is automatically controlled to a predetermined height, then the comparator 31 outputs the difference signal eδ [eδ=Eθ-eθ+E L1 (or E L2 )]. According to the difference signal eδ", the signal E T and the signal E N , the comparator 34 outputs the pulse signal P having the period T and the pulse width ΔT. As shown in FIG. 2(a), the comparator 34 compares saw-tooth wave signal P 2 from the saw-tooth wave circuit 100 with the output P of the absolute value circuit 70 and produces a pulse 1 signal (FIG. 2(b)) which is at a high level when the signal P 2 is larger than the signal P 1 and at a low level when the signal P 2 is smaller than the signal P 1 . Although the signal P 1 is changed further in accordance with the signals E T and E N , this change is omitted in FIG. 2(a). In response to the pulse signal P and the dead zone signal from the dead zone setter 43, the logic circuit 35 and the drive circuit 52 output the control signals Esa, Esb and Esc with the predetermined timing, to drive the direction switching valve 7 to operate the lift cylinder 5 whereby the blade 4 is lifted to reduce the over load. As the load is reduced, the overload signal E L is decreased, as a result of which the blade 4 lifting speed is decreased. Thus, when the overload signal E L becomes the zero level, the blade 4 is stopped at that position. When the blade load is reduced to less than the overload, the blade 4 is controlled in accordance with the above-described inclination setting signal Eθ. That is, the blade 4 is automatically controlled so that its height is equal to or closes to a value corresponding to the predetermined inclination setting angle Eθ.
Referring to FIG. 8, a timer circuit 120 comprises two time constant circuits 71 and 72 which are equal in time constant. The inputs of the time constant circuits 71 and 72 are connected to a line lk. The outputs thereof are connected to a NOR circuit 74. The time constant circuit 71 is so designed that the rise of a signal applied to the line lk is subjected to differentiation, thereby to output a signal "1". The arrangement of the time constant circuit 72 is equal to that of the time constant circuit 71. An inverter 73 is connected to the input of the time constant circuit 72. Therefore, in the time constant circuit 72, the fall of the signal is applied to the line lk to output a signal "1". Position detectors 77, 75 and 79 are, for instance, limit switches, which are turned off when an operating lever 76 is pulled, or a brake pedal 78 is depressed, or a clutch lever 80 is pulled, and which are in "on" state when not operated. Accordingly, when the operating lever 76, the brake pedal 78 or the clutch lever 80 is operated, the signal introduced to the line lk is raised to "1". In the time constant circuit 71, this rise is subjected to differentiation and its output level is maintained at "1" for a predetermined time T. When the operating lever 76, the brake pedal 78 or the clutch lever 80 is restored, the signal on the line 1 is lowered to "0". In the time constant circuit 72, this fall is differentiated, and its output is maintained at "1" for a predetermined period T. The outputs of the two time constant circuits 71 and 72 are applied to the NOR circuit 74. The output of the NOR circuit 74 is inverted. As a result, the timer circuit 70 outputs an inhibit signal e t which is maintained at "1" for the predetermined period T in synchronization with the starting or ending time instant of the operation of the operating lever 76, the brake pedal 78 or the clutch lever 80.
The logic circuit 35 has AND circuits 35a and 35b as shown in FIG. 7. When the AND circuits 35a and 35b are disabled by the signal from the timer circuit 120, the conduction of the pulse signal P is interrupted. Therefore, the electromagnetic valve 12 is not driven (being set at the neutral position) but the electromagnetic valve 13 is driven. Accordingly, the blade is held at the position which is obtained immediately before the logic circuit 35 is disabled (off), i.e., immediately before the operating lever 76, the brake pedal 78 or the clutch lever 80 is operated.
Assume that the operating lever 76 is operated from the time instant t 1 to the time instant t 2 in FIG. 9 so that the output signal e 1 of the position detector 77 is maintained at "1" for this period only as indicated in the part (a) of FIG. 9, and the brake pedal 78 is operated from the time instant t 3 to the time instant t 4 so that the output signal e 2 of the position detector 75 is maintained at "1" for this period only as indicated in the part (b) of FIG. 9, the same thing being effected for the output signal of the position detector 79. In this case, the acceleration (negative acceleration) of the vehicle body is increased at the start and end of each of the above-described operations. As a result, the output signal of the acceleration compensation arithmetic circuit 25 is temporarily increased as shown in the part (d) of FIG. 9 although the actual inclination angle θ is is not so greatly changed. As was described above, the acceleration effect can be eliminated greatly by the circuit 25; however, it is difficult to completely eliminate the acceleration effect.
If the blade is controlled in accordance with the detection values of the inclination detectors 21 and 22 at the start and end of the operation similarly as in the ordinary running period, then the blade 4 is moved up and down even though the actual inclination is maintained unchanged. However, the inhibit signal e t is maintained at "1" for the predetermined period T (1 to 2 seconds for instance) in synchronization with the start time (t 1 or t 3 ) and the end time (t 2 or t 4 ) of each operation as shown in the part (c) of FIG. 9, and the logical circuit 35 is disabled. Therefore, the electromagnetic valve 12 is not operated (being at the neutral position). As a result, the frame angle is held at the value which is obtained immediately before the operation is started or ended. Thus, the blade will never move up and down by the acceleration effect.
As is clear from the above description, the blade angle with respect to the vehicle body is maintained at the value obtained immediately before the operation is started or ended, for one or two seconds after the operation of the operating lever or the brake pedal is started or ended causing the acceleration. Therefore, it is possible to prevent the height of the blade from being changed by the acceleration effect. Furthermore, even if the height of the blade is at a value different from the set value by external disturbance, the blade is held at that height for a very short time. Therefore, the excavation is scarcely affected by this irregular height of the blade.
The valve drive circuit 52 delivers the outputs Esa, Esb and Esc, to drive the electromagnetic valves 12 and 13 and the slave cylinder 9, to operate the direction switching valve 7, whereby the blade 4 is lifted to a predetermined height.
Now, the blade tilt angle automatic control will be described.
This automatic control is carried out substantially similarly as in the blade height control described above.
It is assumed that, under the condition that the blade is held horizontally, the operator has set the lift angle setter so that the blade will be tilted by 5 degrees downwardly on the left side as viewed from the operator.
Then, the tilt angle setter 30 outputs a tilt signal Ec corresponding to the set angle 5 degrees. The signal Ec is applied to the comparator 44. On the other hand, the output e c of the inclinometer 24 is at the zero level because the blade 4 is horizontal. The comparator 44 outputs a difference signal eβ corresponding to the difference between the signal E c and e c . The difference signal eβ is applied to a compensator 45. Similarly as in the compensator 32, the compensator 45 outputs a signal eβ' which is obtained by adding a signal obtained by proportional calculation of the input signal and a signal obtained by differentiating the input signal. The signal eβ' is applied to an absolute value circuit 46.
Similarly as in the pulse control circuit 34, a pulse control circuit 47 outputs a pulse signal P' in response to the signal eβ' and the signal E N . This pulse signal P' has a period T 1 and a pulse width ΔT 1 similarly as in the case of the above-described pulse signal P, and it is the spool position instruction signal of the direction switching valve 14. A logic circuit 48 provides its output when the spool position instruction signal, or the pulse width ΔT 1 of the pulse signal P', exceeds the dead zone signal eΔ of a dead zone setter 49. Therefore, a valve drive circuit 53 outputs a control signal e sa ' to energize the solenoid 17S a of the electromagnetic valve 17, thereby to set the latter 17 to the position 17B. Accordingly, the slave cylinder 16 is expanded to move the rod 15 in the direction of the arrow B, whereby the direction switching valve 14 is switched to the position 14A. When the direction switching valve 14 is completely set to the position 14A, the control signal e sa from the valve drive circuit 53 is turned off to deenergize the solenoid 17Sa, whereby the electromagnetic valve 17 is set to the middle position 17C. As a result, the slave cylinder 16 is held at that position, and the direction switching valve 14 is held at the position 14A. Therefore, the tilt cylinder 6, being supplied with the pressurized oil from the hydraulic pump 19, is contracted, as a result of which the blade 4 is tilted so that the left end is lower.
The inclinometer 24 outputs the inclination signal e c in response to the inclination of the blade 4. The inclination signal e c is applied to the comparator 44.
When the pulse signal P' is set to the zero level, then the valve drive circuit 53 outputs a control signal e sb to energize the solenoid 17S b of the electromagnetic valve 17, whereby the latter 17 is set to the position 17B. Accordingly, the slave cylinder 16 is contracted to move the rod 15 in a direction opposite to the direction B, whereby the direction switching valve 14 is moved towards the neutral position 14C. When the direction switching valve 14 has been moved towards the neutral position for a predetermined period of time or as much as a predetermined distance, the logic circuit 48 and the valve drive circuit 53 set the control signal e sb to the zero level to set the electromagnetic valve 17 to the middle position 17C, and simultaneously output a control signal e sc to energize the solenoid 18S of the electromagnetic valve 18 thereby to set the latter to the position 18B. Accordingly, the supply of the pressurized oil to the slave cylinder 16 is suspended, and simultaneously the bottom chamber and the head chamber are connected directly to the tank T 6 by the electromagnetic valve 18. As a result, the slave cylinder 16 is set free. Accordingly, similarly as in the direction switching valve 7, the direction switching valve 14 is returned exactly to the neutral position 14C by the restoring force of the return spring.
When the direction switching valve 14 is returned to the neutral position 14C, the logical circuit 48 and the valve drive circuit 14 set the control signal e sc to the zero level to deenergize the solenoid 18S, so that the electromagnetic valve 18 is set to the position 18A. Thus, the slave cylinder 16 is held at that position, and the direction switching valve 14 is locked at the neutral position 14C, so that the blade 4 is held at that inclination angle.
The above-described controls are repeatedly carried out to gradually tilt the blade 4. When the tile angle of the blade 4 reaches the set angle 5°, the difference signal eβ from the comparator 44 is set to the zero level. Thus, the tilt angle control of the blade 4 has been accomplished.
The tilt angle of the blade 4 can be controlled so that the right end is lower, in a manner similar to the above-described one.
In this case, similarly as in the above-described control for lifting the blade, as the tilt angle reaches the set angle, the speed of the blade is gradually reduced. Therefore, the blade tilt angle can be set at the set value without causing hunting or the like.
In conducting an automatic control of a blade of a bulldozer both in a lifting and lowering direction (i.e. upward and downward direction) and in a tilting direction (i.e. leftward and rightward direction), a desired earth grading accuracy cannot be obtained if the same control system as the control system for the lifting and lowering direction is simply applied to the control system for the tilting direction. The reason is stated below.
Since a bulldozer normally has only one system of hydraulic circuit and, accordingly, a lift cylinder and a tilt cylinder cannot be operated simultaneously but a predetermined one of either a lift cylinder operation valve or a tilt cylinder operation valve is preferentially operated. Such limitation inherent in the hydraulic system of a bulldozer must be taken into consideration in the control device of the present invention, for if the oil is flowing in one actuator, it does not flow in another however great the difference between a preset value and a detected value may be. Accordingly, if a difference value of the tilting system and that of the lifting and lowering system are respectively compared with corresponding saw-tooth waves to obtain pulse width signals and electromagnetic valves are switched on and off by such pulse width signals, one of the tilting system and the lifting and lowering system which is not given priority is limited in its operation by the operation of the other system which is given priority and there occurs in the one system a time interval during which response cannot be made. This decreases the response characteristic of that system resulting in decreasing in accuracy of the earth grading operation.
In the hydraulic system of a bulldozer, priority is normally given to the tilting system. Higher control performance however is required for the lifting and lowering system than for the tilting system. According to the present invention, priority is given to the control of the lifting and lowering system and the control of the tilting system is conducted only while the lifting and lowering control is not conducted. More specifically, an integration circuit of the tilting system is reset by fall of a pulse signal for driving the valve 12 to initiate integration so that a pulse for driving the valve 12 is immediately outputted when there occurs a difference. Thus, a time interval during which the tilting system is not operated is effectively utilized so that the response characteristic is improved. It is to be noted that a drive signal for the tilting system is not generated while the lifting and lowering system is in operation.
The interrelation between the tilting operation and the lifting and lowering operation will now be described with reference to FIGS. 2(a) through 2(g) and FIG. 10. For convenience of explanation, it is assumed that the engine speed and the oil temperature remain constant.
Referring to FIG. 2(a), if the output of the absolute value circuit 70 varies as shown in curve P 1 , a pulse with a larger pulse width is generated if the level of the pulse is higher as shown in FIG. 2(b). Accordingly, the cylinder stroke of the lift cylinder 5 gradually increases as shown in FIG. 2(c). When the level of the pulse P is 0, the stroke of the lift cylinder does not change but remains as it is.
The tilting control is conducted while the stroke of the lift cylinder remains unchanged. The output of the comparator 34, i.e. pulse P, is applied to a fall detection circuit 90 which thereupon produces a trigger signal as shown in FIG. 2(d). This trigger signal is applied to an integration circuit 102. This circuit 102 generates a saw-tooth wave signal as shown in FIG. 2(e) by starting integration by this trigger pulse. The period of this saw-tooth wave signal is determined by the trigger signal. If the output of the absolute value circuit 46 is as shown by H 1 in FIG. 2(e), the output pulse from the operational amplifier OP of the comparison circuit 47 is as shown by FIg. 2(f). This output is applied to one of input terminals of AND gate AD. To the other input of the AND gate AD is applied the output of the comparator 34 through an inverter. Accordingly, the stroke of the tilt cylinder 6 is controlled as shown in FIG. 2(g). In other words, stroke of the tilt cylinder 6 is controlled only while the lift cylinder 5 of the tilt cylinder 6 is not in operation, i.e. in a holding state. The operation time of the tilt cylinder 6 varies with the level of the output of the absolute value circuit 46. The tilt cylinder 6 is maintained in a holding state unless it is in operation.
As described in the foregoing, the tilt control is not conducted while the lifting and lowering control is in operation. For ensuring this, AND circuits AND 1 and AND 2 (FIG. 1) are provided between the logic circuit 48 and the valve drive circuit 53.
That is, in the case where any lift control is effected, the valve drive circuit 52 outputs a lift priority signal which is applied to the inhibit inputs of the AND circuits AND 1 and AND 2 . Therefore, the output signal from the logic circuit 48 is interrupted, and the tilt control is not carried out.
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An automatic control device for an earth working equipment is directed to remove influence of acceleration on an inclinometer mounted on a vehicle body and thereby to effect an accurate blade control. An acceleration compensation arithmatic circuit receives outputs of a pair of inclinometer and removes an acceleration component by performing integration twice. This circuit is also designed to remove an integration error. Further, according to the invention, a Doppler radar system and an engine speed/throttle opening system are employed for detection of overload applied to the blade so that one of the detection systems which is most suitable for an actual work can be selected. Furthermore, the device includes both blade height controllers and tilt controllers and performs the two control operations most effectively. Response characteristics are improved by conducting the tilt control within a time interval during which the bade is in a holding state which time interval occurs in the control operation by the blade height controller.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to fluid flow control devices. More specifically, the invention concerns an overflow prevention device that can be attached to the drain line of a conventional clothes washing machine system and is so constructed and arraigned to automatically disable the washing machine in the event that the washing machine drain becomes clogged.
[0003] 2. Discussion of the Prior Art
[0004] The typical prior art washing machine is usually connected to a household waste system through an upright drain conduit that is, in turn, interconnected with the household sewer system. Since the modern washing machine includes automatic features that enable the washing machine to be used in an unattended fashion, the accidental clogging of the waste line leading to the domestic sewer almost always results in the overflow of rather large quantities of water. Accordingly, several types of overflow control devices have been suggested in the past to avoid this undesirable result. Exemplary of these prior art devices is that disclosed in U.S. Pat. No. 4,418,712 issued to Braley. The Braley invention includes a conductivity pressure sensor that is placed within the drain or standpipe of the washing machine system for sensing the height of liquid therein. The invention further includes a ground fault circuit interrupter and an optional audible alarm both of which can be operably interconnected with the pressure sensor.
[0005] Another type of overflow control device is described in U.S. Pat. No. 5,028,910 issued to Meacham et al. The Meacham patent discloses an overflow device that includes a vertical offset standpipe extending from a conventional standpipe. The offset standpipe has a flow-actuated switch disposed there within that is engaged when the water level rises in the offset standpipe.
[0006] The patent to Mills, U.S. Pat. No. 5,125,247 discloses a device that is somewhat similar to the Meacham device. However, the flow-actuated switch of the Mills device is located in the main standpipe and not in a secondary standpipe.
[0007] The apparatus of the present invention overcomes many of the drawbacks of the prior art overflow control systems and, in one form, includes a backflow preventor having an inflow end and an outflow end. The outflow end is receivable within a drainpipe such as a two-inch plastic standpipe of the character typically used as a washing machine drain. The inflow end of the device, which includes a stepped outer surface to accommodate drain hoses of various sizes, is sealably connected to the washing machine drain hose. A swing type check valve or flapper is mounted internally of the device. The valve is pushed open when water flows from the washing machine to the drain in a normal fashion. However, if the drain backs up and the water flow reverses direction the flapper is pushed closed. This drain backup also causes a strategically located plunger to move upwardly against the urging of a biasing means. Upward movement of the plunger operates an internally mounted micro switch that is operably connected to a portable ground fault circuit interrupter plug. The washing machine is connected to the ground fault circuit interrupter plug, which, in turn, is connected to a conventional duplex wall outlet. With this novel arrangement, when the flapper is closed and backflow pressure from the drain builds up in the outflow end of the valve, the switch is actuated by the upward movement of the plunger. Actuation of the switch causes a low voltage default which triggers the ground fault circuit interrupter, thereby interrupting power to the washing machine.
SUMMARY OF THE INVENTION
[0008] It is an object of the present invention to provide a backflow prevention device of simple construction that can be used with a conventional washing machine system and one which is uniquely designed to automatically disrupt the power to the washing machine should the drain line leading from the washing machine become clogged.
[0009] Another object of the invention is to provide a backflow prevention device of the aforementioned character that is reliable in operation and easy to connect to washing machine drain hoses of various sizes. More particularly, the inflow end of the backflow prevention device includes a stepped outer surface that will accommodate drain hoses of various sizes.
[0010] Another object of the invention is to provide a backflow prevention device as described in the preceding paragraphs that includes an internally mounted micro switch that is actuated upon the washing machine drain becoming clogged. The micro switch is operably interconnected with a portable ground fault circuit interrupter plug that is connected to a duplex outlet and to which the washing machine is connected. Upon actuation, the switch causes a low voltage default to be sent to the ground fault circuit interrupter that triggers the ground fault circuit interrupter thereby automatically causing an interruption of power to the washing machine.
[0011] Another object of the invention is to provide a backflow prevention device of the character described that includes a generally cylindrical connector member having an inflow end and an outflow end. The outflow end is sealably receivable in the standpipe used as the washing machine drain. The outflow end includes an O-ring type seal for sealing the joint between the sleeve and the outflow end so that the backflow prevention device can be easily removed from the standpipe when it is necessary to clear blockages in the washing machine drain system.
[0012] Another object of the invention is to provide a backflow prevention device that is easy to install and one that can be used with almost any type of conventional commercially available washing machine and like appliance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] [0013]FIG. 1 is a generally perspective view showing the device of the invention interconnected with a conventional washing machine system.
[0014] [0014]FIG. 2 is a greatly enlarged, generally perspective view of one form of the backflow prevention device of the invention.
[0015] [0015]FIG. 3 is an enlarged, cross-sectional view of the backflow prevention device shown in FIG. 2.
[0016] [0016]FIG. 4 is a generally perspective, exploded view of the backflow prevention device shown in FIG. 2.
DESCRIPTION OF THE INVENTION
[0017] Referring to the drawings and particularly to FIGS. 1 and 2, one form of the invention can be seen to comprise in combination a washing machine 10 powered from an electrical outlet 12 via current flowing through an electric circuit and a backflow prevention system generally designated by the numeral 14 . The washing machine 10 is adapted to receive water from a water supply (not shown) at predetermined intervals in a washing cycle and to remove the water through a drain hose 16 at predetermined intervals in the washing cycle. A standpipe 18 is interposed between the washing machine 10 and the household drainage system for conveying water to the household drainage system.
[0018] In the present form of the invention, the backflow prevention device comprises a hollow housing 20 defining a flow passageway 22 having an inlet 24 (FIG. 3) interconnected with the drain hose 16 and an outlet 26 interconnected with standpipe 18 . A valve, such as a flapper valve assembly 28 , is mounted within flow passageway 22 intermediate the inlet and the outlet. Valve assembly 28 , which comprises a valve member 28 a and a cooperating gasket 28 b , is movable from a first closed position shown by the solid lines in FIG. 3 to a second open position shown by the phantom lines in FIG. 3 in response to water flowing into the inlet. Valve 28 is movable from the second open position to the first closed position in response to water flowing from outlet 26 toward inlet 24 in the direction of arrow 27 of FIG. 3. A valve biasing means, which is connected to the hollow housing, yieldably urges the valve toward said first closed position.
[0019] Forming an important feature of the backflow prevention device of the present invention is switch means, which is carried by housing 20 and is operably associated with the electric circuit for interrupting the flow of current through the electric circuit upon actuation of the switch means. The backflow prevention device also includes operating means carried by housing 20 . The operating means is operably associated with the switch means and functions to operate the switch means in response to water flowing from outlet 26 toward inlet 24 . The construction and operation of these important features of the invention will be described in greater detail the paragraphs which follow.
[0020] Referring particularly to FIG. 3, it is to be noted that hollow-housing 10 includes first and second side chambers 30 and 32 that are in communication with flow passageway 22 . In the present form of the invention, the operating means comprises a plunger 34 that is reciprocally movable within side chamber 30 from a first position to a second position in response to water flowing from outlet 26 toward inlet 24 (see also FIG. 4). An elastomeric O-ring 35 prevents fluid leakage past the plunger. Plunger 34 includes an elongated, outwardly protruding operating stem 34 a , the purpose of which will presently be described. As best seen in FIG. 3, the upper portion of chamber 30 is closed by a cap 38 having a central aperture 38 a through which stem 34 a protrudes.
[0021] Connected to cap 38 is a hollow switch housing 40 within which the switch means of the invention is mounted. The switch means here comprises a readily commercially available micro switch 42 that is operably associated with the electric circuit of the apparatus for interrupting the flow of current upon actuation of the micro switch by the operating means of the invention. Micro switch 42 is available from various commercial sources such as Micro Switch Co. of Freeport, Ill. Micro switch 42 includes a downwardly extending operating arm 42 a that is engageable by stem 34 a as plunger 34 is moved upwardly within chamber 30 in response to fluid flowing from outlet 26 toward the plunger in the direction of arrow 27 (FIG. 3). As illustrated in FIG. 1, micro switch 42 is operably interconnected by means of the electrical conduit 44 with a portable ground fault circuit interrupter (GFCI) plug 46 that also forms a part of the circuit interrupting means of the invention.
[0022] GFCI plug 46 is readily commercially available from various sources, including TRC of Clearwater, Fla. The details of the construction and operation of plug 46 can be obtained from the TRC Company and are also described in U.S. Pat. No. 4,567,456 issued to Legatti. Reference should be made to this patent for an understanding of the operation of GFCI plug 46 . As shown in FIG. 1, plug 46 , which is plugged into duplex outlet 12 , is constructed and arranged to receive the power plug 10 a of the washing machine 10 which is, in turn, connected to the washing machine power cord 10 a . With the arrangement shown in FIG. 1, the reset switches 46 a of the GFI plug are readily accessible. As previously mentioned, micro switch 42 is operably interconnected with plug 46 by electrical conduit 44 . More particularly, the wires of conduit 44 are connected at one end to the upper terminals of the micro switch and are connected at the other end in parallel to the leads running to the reset switches 46 a of the GFI plug 46 . This electrical interconnection of micro switch 42 with the GFI plug 46 is well understood by those skilled in the art.
[0023] In using the apparatus of the invention, a waste line connector means, which here comprises a generally cylindrically shaped member or connector collar 50 is connected to the upper open end of the standpipe 18 . As best seen in FIG. 3, member 50 has an open top portion and an inwardly tapering sidewall that is sealably receivable within standpipe 18 and a manner shown in FIG. 1. With a connector collar thusly sealably inserted into the upper end of the standpipe 18 and locked in place by the bayonet type locking arrangement 51 , the lower cylindrical portion 20 a of hollow housing 20 is inserted into the connector collar 50 in the manner shown in FIG. 3. As shown in FIG. 3, hollow-housing 20 includes a flange 20 b that engages the upper portion 50 a of collar 50 when the lower portion of the hollow housing is fully seated within the connector collar. An elastomeric O-ring 52 and is disposed between the flange 20 b and upper portion 50 a to prevent leakage between the mating components.
[0024] With the hollow housing 20 mated with the standpipe 18 in the manner described in the preceding paragraph, the water supply connector means of the invention is connected to the upper portion of second chamber 32 in the manner best seen in FIG. 3. In the present form of the invention, the water supply connector means comprises a hollow member 54 made up of a plurality of interconnected, generally cylindrically shaped segments of different outside diameters, such as segments 54 a , 54 b , 54 c , 54 d and 54 e . The novel construction of member 54 permits the convenient interconnection therewith of drain lines of various inside diameters.
[0025] During the normal operation of the washing machine, as the water flows from the washing machine to the drain hose 16 , flapper valve 28 is pushed open against the urging of a flapper valve biasing means shown here as a torsion spring 56 . However, if the drain becomes clogged causing the drain water to back up and to flow in the direction of the arrow 27 , the flapper valve 28 will be pushed closed in the manner shown by the solid lines in FIG. 3. This drain backup and reverse flow of the drain water also causes plunger 34 to move upwardly against the urging of a plunger biasing means shown here as a coil spring 58 . Upward movement of the plunger causes the plunger stem 34 a to engage the downwardly extending switch operating arm 42 a in a manner to actuate micro switch 42 , which as previously mentioned, is operably associated with the portable ground fault circuit interrupter plug 46 . As also previously mentioned, washing machine 10 is electrically connected to the ground fault circuit interrupter plug, which, in turn, is connected to the conventional duplex wall outlet 12 . Actuation of micro switch 42 causes a low voltage default to be sent to the ground fault circuit interrupter, which triggers the ground fault circuit interrupter causing an automatic interruption of the power flowing to the washing machine.
[0026] Following an interruption in power, the backflow prevention body 20 can be easily removed from the connector collar 50 to enable the clog in the drain system to be cleared. Once the clog is cleared, body 20 can be once again sealably interconnected with connector collar 50 and the ground fault circuit interrupter plug 46 can be reset using reset switches 46 a . This done, normal operation of the washing machine can once again commence.
[0027] Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.
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A backflow prevention device for use with a conventional washing machine system that is uniquely designed to automatically disrupt the power to the washing machine should the drain line leading from the washing machine become clogged. The backflow prevention device includes an internally mounted micro switch that is operably interconnected with a portable ground fault circuit interrupter plug that is connected to a duplex outlet. The washing machine is connected to the ground fault circuit interrupter plug so that, upon being actuated, the micro switch will cause a low voltage default to be sent to the ground fault circuit interrupter which triggers it in a manner to automatically cause an interruption of power to the washing machine.
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RELATED APPLICATION DATA
[0001] This invention is a continuation of Ser. No. 11/301,331 filed on Dec. 13, 2005, which is a continuation of Ser. No. 09/540,482 filed on Mar. 31, 2000, now abandoned, which is a continuation of Ser. No. 09/394,219, filed on Sep. 13, 1999, now U.S. Pat. No. 6,375,469, which is a continuation of Ser. No. 08/814,293 filed on Mar. 10, 1997, now U.S. Pat. No. 5,951,300, which is a continuation of Ser. No. 08/784,270, filed Jan. 15, 1997, now U.S. Pat. No. 5,887,133, each of which is incorporated by reference in its entirety.
FIELD OF THE INVENTION
[0002] The present invention relates generally to modifying documents sent over a communications network, and in particular to a system and method for determining the information contents of document portions and replacing undesired document portions with substitute document portions or inserting substitute document portions.
BACKGROUND OF THE INVENTION
[0003] To a large degree, the information age has been brought about by rapid advances in the field of communications and communications networks in particular. Increasingly, information which could formerly be presented in tangible, permanent media is reformatted and rendered for display on screens and monitors. Virtually any information presentable as text or text and graphics is being converted into suitable electronic messages or packets for shuttling across a communications network.
[0004] A communications network, e.g., the Internet, has an architecture in which information packets from resources or content providers is made available through service providers to users who subscribe to the service. The actual transmission takes place over the communication links of various bandwidths and types which make up the network. Content providers typically store this electronic data on server machines connected directly to the Internet in standard format. The data is broken down into packets and these are then transmitted over the communication link. Among the diverse types of information which may be placed on the Internet in this way are articles, news briefs and updates, weather maps, books, summaries, files, software, catalogues, documents, pictorials, video files, public records, commercial literature and so forth.
[0005] Clearly, the number of packets which can be transmitted via a communications network is vast and varied. To aid in sorting, routing and transmitting information on the Internet the content of any given packet is usually identified by its origin (address of the content provider), a brief summary located in a conspicuous portion of the packet (e.g., in the header) or some other identification information. For example, the Internetwork Packet Exchange (IPX) protocol followed by NetWare routers, distributed by Novell, Inc., execute a so-called Routing Information Protocol (RIP) and Service Advertising Protocol (SAP). The RIP protocol involves periodic RIP broadcast packets containing all routing information known to the router. These packets are used to keep the global network synchronized. In addition, the protocol provides for periodically sending SAP broadcast packets containing all server information known to the SAP agent. Thus, the network system keeps track of the contents of the various packets to facilitate transfer, mitigate traffic problems and perform other vital operations.
[0006] In U.S. Pat. No. 5,530,852 issued to Meske, Jr. et al. the inventors disclose a method and system for receiving information in a first file written in a first markup language and identifying the information contents. The method and system ensure that even complex packets of information are processed by generating a list of profiles and topics for each list of the profiles. Secondary and tertiary files are created with anchors referencing particular information in the first file. A parsing procedure is taught by Meske to ascertain whether any information in the first file (original packet) is relevant. If so, fourth and fifth files containing the desired information are created and sent to the user.
[0007] Meske's system and method can be adapted to block or filter entire packets or portions thereof on a content-basis before performing the necessary steps to display the information—usually in the form of a page—on the user's screen. The document is later parsed to extract the profile and build additional pages to catalog and access the information. This method for building a knowledge base with embedded content profiles and in a document is useful but limited to processing the received information only.
[0008] The above-mentioned IPX protocol and similar methods which determine the information contents of packets and use them in the routing process can be employed to control the transfer of packets.
[0009] For example, U.S. Pat. No. 5,541,911 issued to Nilakantan et al. discloses a remote smart filtering communication management system which uses the information contents data to alleviate network traffic problems.
[0010] In particular, Nilakantan controls the traffic across a communication link between a remote network and a central device by applying forwarding rules. The resources monitor the characteristics of the forwarded data packets received across the communication link to learn characteristics of the users of the remote network. In response to the learned characteristics, the resources generate link management messages and forward these to the remote interface. The remote link management resources in the remote interface are responsive to the link management messages and tailor the forwarding rules to the user characteristics. The packets can now be filtered or blocked based on user characteristics.
[0011] The use of selective blocking and filtering of packets by Nilakantan et al. is applied to ultimately reduce network traffic. The invention is centered around sending management messages which are then used to optimize packet traffic across given links in the network. In other words, the problem addressed by this invention is the high volume caused by the proliferation of packets on the network.
[0012] Blocking and filtering of packets or their parts can be employed to speed up the page rendering process on the user's screen. For example, blocking functions may restrict packets from a list of providers or an entire block of providers from ever being sent to the user. This feature allows one to prevent undesired packets (e.g., packets containing adult material) from being sent to the user and rendered on his or her screen. Filters can be preset to chose packets based on the time they require for rendering or in accordance with other user-specified standards (e.g., information contents). Proper application of these two functions results in an optimized and personalized page rendering procedure.
[0013] In the most common practical scenario, however, a network user sends a direct request for an entire document from a terminal located on his or her premises to the service provider. The provider verifies whether the document is already stored in local memory and, if not, obtains this document from the content provider. While the user's request is processed the service provider usually passes on to the user a number of unsolicited document portions, e.g., document portions from other service providers such as advertisement servers. Thus, the subscriber receives, in addition to the requested document(s), numerous other document portions of varying degrees of interest or importance to him or her. When the page is rendered on the user's screen these embedded document portions are displayed as a part of the document.
[0014] Under these circumstances, what is needed is a system and method for modifying or substituting undesired document portions rather than performing blocking and filtering functions on the packet level. For example, the service provider, the user or another party may wish to exchange or modify a document being sent to the user. This situation may occur when the service provider wishes to enclose vital information with the document requested by the user. The use of the bandwidth allocated to a less important document portion, hence a document portion swap, would be highly appropriate for this purpose. In another situation, the user may wish to block undesired document portions. For instance, when recording television programming on the VCR recorder the user can selectively block advertising material from being recorded. Analogously, when rendering a web page the user may wish to omit specific document portions from being rendered on the page.
[0015] At the present time the problems associated with this type of document modification have not been addressed, much less solved. Consequently, what is needed is a system and method which solves the problems associated with document modification based on the information contents in a communications network such as the Internet.
OBJECTS AND ADVANTAGES OF THE INVENTION
[0016] In view of the above, it is an object of the present invention to provide a system and a method for modifying documents, and specifically for replacing an original document portion with a substitute document portion or inserting a substitute document portion in a communications network, where the replacement decision is made based on the information content of the original document portion.
[0017] It is another object of the invention to perform this exchange operation in an efficient manner in a convenient part of the network and to allow the network user to decide which document portions should be exchanged.
[0018] Yet another object of the invention is to perform the document modification according to decisions derived from the service provider.
[0019] Still another object of the invention is the ensure that the system and method of invention can be integrated in any communications network in which content providers, service providers and users are connected via communication links (e.g., the Internet).
[0020] These and other objects and advantages will become more apparent after consideration of the ensuing description and the accompanying drawings.
SUMMARY OF THE INVENTION
[0021] The objects and advantages of the invention are ensured by a system and method applied to a communications network which transmits information in the form of documents or rather document portions, e.g., the Internet. An original document is modified to produce a modified document based on the original document portions and, specifically, based on an identifier portion and an information portion of each original document portion. A substitute document portion is inserted in the place of each undesired original document portion. The system according to the invention provides for a number of content providers whose servers transmit documents or document portions on the network. Service providers relay these document portions to a given network user, who displays them on a user set, e.g., a computer or a television set.
[0022] The system has a controller, typically a proxy server, for parsing the original document to locate the identifier portion of each of the original document portions, determining the information portion of each original document portion to identify the undesired original document portion, i.e., an original document portion which has an undesired content, and issuing a swap order the undesired original document portion is found. For instance, the undesired content may be an advertisement or a message not relevant to the information which the user desires to view on his or her user set.
[0023] A substitute document server receives the swap order and sends the substitute document portion to the controller. A swapping device or mechanism inserts the substitute document portion in place of the undesired original document portion. At this point the substitute document portion can be passed on to the user set and displayed. Depending on the communications network and user preferences, the actual display set can be a computer, a television set, or any other suitable end terminal with a display screen.
[0024] In one version of the system according to the invention the controller is located on the premises of the user, i.e., at the user's residence or at his or her work place. Advantageously, in this embodiment the controller can be integrated with the user set. It is also possible to integrate the swapping mechanism with the controller. Of course, the controller can also be located on the premises of the service provider and be integrated with the swapping mechanism there. In this situation the role of the controller and swapping mechanism can be most efficiently performed by the proxy server.
[0025] The identifier portion of any original document portion can be as simple as a network address. In general, this will be the network address of the content provider who placed the document portion on the network. (Address-based identification is one of the most common ways of identifying document portions.) The content of the information portion can be easily determined as desired or undesired from the provider's address. For this purpose, the controller should have in its memory or some other accessible storage resources a list of network addresses of content providers. In another embodiment the identifier portion will have a brief description or designation of what is contained in the information portion. Such identifier portion will generally consist of any number of signs and/or characters (usually abbreviations).
[0026] In a preferred embodiment the controller has a device or mechanism for matching the dimensions of the substitute document portion with the dimensions of the original document portion being replaced, i.e., the undesired original document portion. This provision ensures that the swapped information will be of appropriate size when rendered on the user's screen, thus preserving the page layout which would have been obtained without swapping.
[0027] A further embodiment adds to the system a user profile bank. The bank has user profile information, e.g., statistical information, personal preferences or any other information either compiled or gathered directly from the user. The profile information is delivered to the controller such that the swap order can be issued based on the user's preferences to tailor the substitute document portions to the user's needs or other relevant profile information.
[0028] The system of the invention can be used in any communications network having the general architecture described. As mentioned above, the Internet is well-suited for the system of the invention. The method of swapping undesired original document portions with substitute document portions is practiced in communications network exhibiting the same architecture as required for the system.
[0029] A detailed description of the system and method of the invention are set forth below in reference to the drawing figures.
BRIEF DESCRIPTION OF THE FIGURES
[0030] FIG. 1 is a block diagram of one embodiment of the system of invention.
[0031] FIG. 2 is a diagram of a document portion.
[0032] FIG. 3 is a block diagram of another embodiment of the system of invention.
[0033] FIG. 4 is an example screen display on a user's set.
[0034] FIG. 5 is a diagrammatic representation of an original document portion and a substitute document portion.
[0035] FIG. 6 is a flow diagram showing how a swap order is issued.
[0036] FIG. 7 is a flow diagram showing how a swap order is issued when profile bank information is available.
[0037] FIG. 8 is a diagram illustrating typical placement of undesired original document portions on a page.
[0038] FIG. 9 is a diagram illustrating the replacement of undesired original document portions with specified substitute document portions.
DETAILED DESCRIPTION
[0039] An advantageous embodiment of the invention is illustrated in the block diagram of FIG. 1 . A document modification or swapping system 10 possessing the necessary architecture to practice the invention is built around a communications network 12 . The individual links and resources of network 12 are not shown, but are generally known to include couplings, high and low bandwidth links, filters, power sources, repeaters, transformers, up- and down-converters, amplifiers and any number of other equipment required to efficiently transmit information across large physical distances. Network 12 may be a stand-alone network or one which takes advantage of existing connections and resources, e.g., telephone lines. In the preferred embodiment network 12 is simply the Internet.
[0040] Two content providers 14 , 16 are connected to network 12 via communication links 18 and 20 respectively. Any suitable medium of sufficient bandwidth to transmit the required information to and from network 12 can be used as links 18 , 20 . Content providers 14 , 16 are servers equipped with the necessary resources to transmit and receive information, specifically requests or queries for the contents of their data banks (not shown). Typically, content providers 14 , 16 have information such as articles, news briefs and updates, weather maps, books, summaries, files, software, catalogues, documents, pictorials, video files, public records, commercial literature and so forth.
[0041] Provider 14 is an independent server, while provider 16 is a part of a larger resource 22 including an advertisement server 24 (hereafter “ad server”). Although it is understood that either provider 14 or 16 may place on network 12 various types of information, e.g., requested files, non-requested information, undesired information and advertising material, the distinction between ad server 24 and provider 16 is useful for better illustrating the operation of system 10 . Thus, in the present embodiment it will be assumed that ad server 24 places, via provider 16 , on network 12 unsolicited information, i.e., commercials and advertisements, while provider 16 delivers requested and/or desired information.
[0042] System 10 also has dedicated ad servers 26 and 28 which deliver to network 12 via communication links 30 and 32 commercials and advertisements in the broadest sense.
[0043] A substitute document server 34 is connected with network 12 by communication link 36 . Server 34 contains information which is not requested or solicited but is desirable or useful. For example, server 34 may contain health-related information, warnings, general advisories and many other types of information.
[0044] The different types of information placed on network 12 by providers 14 , 16 , ad servers 24 , 26 , 28 and substitute document server 34 are formatted in documents or document portions such as document portion 40 shown in FIG. 2 . It is understood that the fundamental building blocks of document portion 40 are information packets (not shown). Although the detailed structure of document portion 40 will be adapted to network 12 each document portion 40 has the same general make-up. A header or an identifier portion 42 generally precedes an information portion 44 with the actual information content. In some cases a footer 46 may be provided to designate the end of document portion 40 . Frequently, identifier portion 42 is simply the network address of the server which placed document portion 40 on network 12 . Alternatively, identifier portion 42 contains a designation or identification of the information contained in portion 44 . Examples of different forms which identifier portion 42 can assume when network 12 is the Internet are discussed below.
[0045] A service provider 50 is in communication with network 12 via communication link 52 . Typically, service provider 50 will have numerous lines 54 connecting directly to the subscribers or network users. In particular, line 54 A establishes a link between service provider 50 and a user set 56 on user premises 58 . When network 12 is the Internet user set 56 is a computer or a network unit. Other devices such as television sets or display devices capable of receiving and/or sending document portion 40 can be used as well. A person of average skill in the art will be able to ensure a suitable connection of user set 56 with service provider 50 .
[0046] A controller 60 is switched between user set 56 and service provider 50 . Controller 60 is capable of reading identifier portion 42 of a document portion 40 to determine the content of information portion 44 . A swapping device 62 , preferably integrated with controller 60 as shown, is also provided to receive a swap order which controller 60 issues when information portion 42 of a packet 40 has an undesirable content.
[0047] The operation of system 10 is now described for the case in which network 12 is the Internet. As an example, FIG. 4 shows a screen display or a page 70 on user set 56 . Page 70 is actually constructed from a number of original document portions analogous in all respects to document portion 40 . The below listing identifies how the page is rendered from original document portions A, B, C, D and E. The formats used conform to the widely accepted and well-known hyper-text mark-up language (HTML).
[0000] Example Page:
[0048] HTML for Document Portion A
Friday December 6 1:59 PM EST </strong> <!-- Text Start--> <p> <h2><a href=/headlines/961206/tech/summary_1.html>Technology Summary</a></h2> <hr> <h2>Headlines</h2> <ul> <li><a href=/headlines/961206/tech/stories/free_1.html><b>Free Market Approach For Internet Urged</b></a> <li><a href=/headlines/961206/tech/stories/copyright_3.html><b>Internet Industry Officials Skeptical of Copyright Rules</b></a> <li><a href=/headlines/961296/tech/stories/telecom_1.html><b>U.S. To Push Telecommunications Aims At WTO</b></a> <li><a href=/headlines/961206/tech/stories/ntt_1.html><b>NTT To Be Restructured But Plan Draws Fire</b></a> <li><a href=/headlines/961206/tech/stories/nttanalysis_1.html><b> Global Competitors Have Little To Fear In NTT</b></a> <li><a href=/headlines/961206/tech/stories/millennium_1.html><b> Countries And Companies Slow To Defuse Millennium Bomb</b></a> <li><a href=/headlines/961206/tech/stories/sales_1.html><b>U.S. Consumer PC Holiday Sales Off To Slow Start</b></a> <li><a href=/headlines/961206/tech/stories/taxes_1.htm><b>Intern et Said Creating Confusing Tax Burden</b></a> <li><a href=/headlines/961206/tech/stories/creative_1.html><b>Cre ative Partners U.S. Technology Firms</b></a> </ul> </body> </html> HTML for document portion B <html> <head> <title>Technology Summary</title> </head> <body> HTML for document portion C (Advertisement) <!-- AdSpace --> <!-- AdParam yhn000001424187 --> <center><p><a href=“http://www.yahoo.com/SpaceID=yhn00000142/AdID =4187/?http:// community.zdnet.com/register/register.cgi”><img width=460 height=55 src=“http://www.yahoo.com/adv/zdi2/password5.gif” alt=“[Too many passwords to remember? Download Password Pro for free.]” border=0></a> <p></center> <!--/AdSpace--> HTML for document portion D (Links) <center><strong>[ <a href=/headlines/>Index</a>| <a href=/headlines/news/>News</a>| <a href=/headlines/international/>World</a>| <a href=/headlines/business/>Biz</a>| <strong>Tech</strong> <a href=/headlines/politics/>Politic</a>| <a href=/headlines/sports/>Sport</a>| <a href=http://sports.yahoo.com/>Scoreboard</a>| <a href=/headlines/entertainment/>Entertain</a>| <a href=/headlines/health/>Health</a> ]</strong> </center> <p> HTML for document portion E (Processing User Input) <center> <form method=get action=“http://search.main.yahoo.com/search/news”> <hr> <input size=24 name=p> <input type=submit value=“Search News”> <input type=hidden name=n value=10> <a href=“http://www.yahoo.com/docs/info/news_search_help.html”> <small>Help</small></a><br> </form> </center> <!--StartLinks--> <!--EndLinks--> <hr> <strong> <!-- Yahoo Time Stamp: 849898740 -->
[0049] In the above example original document portions A, B, C, D and E correspond to those indicated in FIG. 4 . The information rendered and displayed on page 70 is of the news type and it is understood that any other type of information can be involved. Original document portion C contains an ad which originated in one of ad servers 24 , 26 or 28 and was not requested by the user. Specifically, document portion C starts with identifier portion 42 indicating that the information to follow is an ad.
<!-- AdSpace --> In an alternative case, identifier portion 42 can legitimately contain: <a href=“http://www.yahoo.com/SpaceID=yhn00000142/AdID=4187/?http :// community.zdnet.com/register/register.cgi”>
[0050] Here, portion 42 identifies the network address of ad server ( 24 , 26 or 28 ). It is clear that a number of commands is required to render document portion C. These commands relate to proper spacing, location and other parameters of document portion C. The format of these commands is commonly known and widely used, e.g., in the layout of home pages for Internet users. A person of average skill in the art will know how to interpret the commands and how they act to render document portion C on user set 56 .
[0051] During operation the network user will send requests from user set 56 to service provider 50 for specific information, e.g., |Biz| in section D. Service provider 50 will, based on this request, obtain the desired information from content provider 14 or 16 (depending on which provider has the information). Of course, service provider 50 may have already downloaded the information in question. This may be the case with frequently asked for data, minute-by-minute updates, etc. In such situation provider 50 can comply with the request without looking for the information on network 12 . In any case, however, the requested information originates at provider 14 or 16 .
[0052] The document as finally rendered on the screen of user set 56 thus consist of many document portion such as portion 40 . As shown in FIG. 5 , the specific document portion requested by the user is referred to as original document portion 100 for clarity. After original document portion 100 is obtained from provider 14 or 16 (or retrieved from the memory resources (not shown) of service provider 50 ) it is transmitted via line 54 A to controller 60 . An identifier portion 102 of original document portion 100 is read by controller 60 to determine the content of information portion 104 of original document portion 100 .
[0053] As explained above, an ad from ZDNet, which is considered undesirable content, has identifier portion 102 describing the information to follow as <!-AdSpace-->. Alternatively, identifier portion 102 may simply contain the network address <a href=“http://www.yahoo.com/SpaceID=yhn00000142/AdID=4187/?http://community.zdnet.com/register/register.cgi”>of ad server ( 24 , 26 or 28 , depending on which server placed the ad on network 12 ).
[0054] Controller 60 has properly received from user set 56 the request for |Biz|. While parsing the original document obtained as a result of the request controller 60 detects identifier portion 102 of original document portion 100 (in this case the same as document portion C described above) which contains <!--AdSpace-->. These characters distinctly signal that the information in original document portion 100 is an undesired original document portion (in this case unsolicited). Consequently, controller 60 will issue a swap order to swapping mechanism 62 .
[0055] The swap order is formatted as any other information request (e.g., the one for |Biz|) and is addressed to substitute packet server 34 . FIG. 6 shows of flow diagram detailing the steps involved in generating and issuing the swap order. It is understood that the software for executing these steps can be written by any person skilled in the art.
[0056] The swap order travels via line 54 A to service provider 50 who procures the requested substitute document portion 110 (see FIG. 5 ) from substitute document server 34 . Substitute document portion 110 has dimensions D(x,y, 110 ) when rendered as show in FIG. 5 . Preferably dimensions D(x,y, 110 ) are close or equal to dimensions D(x,y, 100 ) of original document portion 100 . This provision will ensure that page 70 on the user set 56 will have approximately the same size as if original document portion 100 had been received and rendered on the screen of user set 56 . In many cases this request can be easily satisfied since the size and width of any document portion when rendered is generally provided as a rendering hint and can be read directly from the HTML code. In the above example original document portion C includes the hint: <img width=460 height=55. In other cases controller can either fetch the content of original document portion 100 to determine the rendered size.
[0057] Alternatively, when identifier portion 102 contains the address <a href=“http://www.yahoo.com/SpaceID=yhn00000142/AdID=4187/?http://community.zdnet.com/register/register.cgi”>controller 60 will be alerted that the information in original document portion 100 is undesired. That is because controller 60 keeps a list of addresses of content providers or ad servers or both. By comparing the address of portion 102 with the addresses of providers 14 , 16 controller can ascertain that information portion 104 is undesirable, since the address of zdnet (one of ad servers 24 , 26 or 28 ) is not on the list. If controller 60 is working with a list of ad servers 24 , 26 or 28 it will determine that information portion 104 is undesirable when identifier portion 102 contains the address of one of ad servers 24 , 26 or 28 . Clearly, when using the address-based method of identifying undesirable information the address lists should be updated frequently.
[0058] At this point, controller 60 will issue a swap order, as described above, to swapping mechanism 62 . The swap order will be used, as explained above, to procure substitute document portion 110 from substitute document server 34 . Again, it is preferable that dimensions D(x,y, 110 ) of substitute document portion 110 be approximately equal to dimensions D(x,y, 100 ) of original document portion 100 .
[0059] Another embodiment of the invention is shown in FIG. 3 . As in the first embodiment, a document modification system 200 consists of content providers 14 , 16 , ad servers 24 , 26 , 28 connected to network 12 by communication links 18 , 20 , 30 and 32 . Substitute document server 34 is connected to network 12 by link 36 .
[0060] A service provider 202 with lines 204 going out to subscribers is connected to network 12 via link 206 . A controller 208 , most conveniently a proxy server, is connected directly to a number of lines 204 on which the document portion swapping or insertion function is desired. Controller 208 may be integrated in the circuitry of service provider 202 or be a stand-alone unit. A swapping mechanism 210 is connected to controller 208 and, in a particularly convenient embodiment, can be integrated with the circuitry of controller 208 and service provider 202 . The choice of how service provider 202 , controller 208 and swapping mechanism 210 are arranged and interconnected can be determined by the circuit designer. In fact, if service provider 202 has all the necessary hardware and circuitry then the functions of controller 208 and/or swapping mechanism 210 may all be performed by service provider 202 given the appropriate software.
[0061] A particular line 204 A shows the path from service provider 202 to user set 212 on user premises 214 . In this embodiment no additional equipment is required of the user. This means that user set 212 is simple to install and may, for example, be a television set configured for WebTV.
[0062] A profile bank 216 is also connected via line 218 to service provider 202 . Bank 216 typically contains user information such as user preferences, past activity data or even medical records. The connection with bank 216 is such that service provider 202 may request and obtain user profile information from bank 216 .
[0063] The operation of this embodiment is analogous to that of the first embodiment. The difference is that the functions of parsing original document and specifically original document portions 100 and deciding whether to issue a swap order for substitute document portion 110 are performed by service provider 202 . In addition, when issuing the swap order, swapping mechanism 210 may take into account the profile of the user obtained from bank 216 .
[0064] For example, data bank 216 may contain the medical records indicating that the user is a diabetic and should be reminded to monitor their blood glucose level. In this situation, when original document portion 100 is undesired, swapping mechanism 210 will issue a swapping order addressed to substitute document server 34 to provide a substitute document portion 110 in which information portion 114 contains the message “remember to monitor your blood glucose level”. In the event the user is trying to quit smoking, substitute document portion 110 may contain the following message: “Don't give up! You can quit smoking!”.
[0065] FIG. 7 shows in flow diagram format how the swap order is generated and issued. Swapping mechanism 210 and controller 208 will perform these steps with the aid of conventional software steps which can be programmed by a person skilled in the art.
[0066] In a preferred embodiment of the invention system 10 is used in conjunction with a browser software installed on user set 56 . Browsers are well-known and commonly used to communicate on the Internet. Examples of suitable browsers include the Netscape Navigator© supplied by Netscape, Inc. and Internet Explorer© provided by Microsoft, Inc. The operation of all components is as described above with the difference that the browser software performs the function of controller 60 and swapping mechanism 62 according to the diagram of FIG. 6 .
[0067] For example, the user may wish to be updated on the local news rather than receive advertisements. In this case the user will select under the options “what to swap” to receive information content 114 concerning local news.
[0068] Alternatively, the user may wish to be reminded of other important personal information. For example, the user may have asthma. He or she will then select substitute document portion 110 to contain a reminder to take their respiratory peak flow reading or appropriate medication. Clearly, the information can be tailored to any user according to need. To offer these options substitute document server 34 has to be loaded with the appropriate information.
[0069] In a particularly advantageous embodiment of the invention the browser can be instructed to replace all banner ads. These ads are located using the techniques discussed above. Two typical web pages 240 with banner ads 242 are shown in FIG. 8 . Ads 242 are located in the middle of each page 240 between sections A and B. The browser will easily recognize and swap these ads with substitute document portions which render to messages 244 as shown in FIG. 9 .
[0070] In an embodiment adapted to current practice controller 60 , 208 can even determine where an address of an identifier 102 is directed to by going to that address. This has to be done when ad servers require the user to “click” on them to go to a web page which describes the item. In most cases the “click-through” web page is hosted on a different service. As the page is being rendered, controller 60 , 208 operating according to the method of the invention can determine where each HREF instruction goes by looking up network addresses as registered in the Domain Network Server (DNS). An HREF which is part of an image that is associated with a different address than the source HTML from content provider 14 , 16 is usually an advertisement.
[0071] Many ad services keep track of “click-through” rates. This is done by aliasing an address on the current service which bounces the click to the target address. In this way the service can count how often the alias was used. The method of invention can be adapted to this situation in two ways.
[0072] According to a first strategy, the reference can be identified by making an HTTP request from the HREF address and then looking at the reply address. If a redirect to another site is discovered then the document portion most likely contains an advertisement.
[0073] A second strategy is to parse the HREF string. In the listing shown above the redirect address contained in original document portion C is easy to find; it is: href=“http://www.yahoo.com/SpaceID=yhn00000142/AdID=4187/?http://community.zdnet.com/register/register.cgi”>. Although the request is part of the “yahoo.com” address, the redirect goes to “community.zdnet.com”. A DNS lookup of this address reveals that it belongs to a different service and that document portion C is an ad.
[0074] Finally, the swapping function according to the invention can be used as an insert function. For example, if original document portion 100 contains a blank, controller 60 , 208 can send a request for substitute document portion 110 to fill this blank. In this manner the space on the rendered page is more completely and efficiently utilized.
SUMMARY, RAMIFICATIONS, AND SCOPE
[0075] Although the above description contains many specificities, these should not be construed as limitations on the scope of the invention but merely as illustrations of the presently preferred embodiment. Many other embodiments of the invention are possible. For example, the functionality of the controller and swapper may reside in software installed on the service provider's resources. Alternatively, software resident in the user set may cooperate with software in the service provider's resources to provide the functionality of the controller and swapping mechanism.
[0076] Therefore, the scope of the invention should be determined not by the examples given but by the appended claims and their legal equivalents.
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A system and method applied to a communications network which transmits document portions in which an original document portion having an identifier portion and an information portion is replaced or swapped with a substitute document portion. The system has a controller, typically a proxy server, for reading the identifier portion of the original document portion, determining the information portion of the original document portion, and issuing a swap order when an undesired original document portion is found. A substitute document server receives the swap order and sends the substitute document portion to the controller. A swapping device or mechanism inserts the substitute document portion in place of the original document portion and the substitute document portion is passed on to the user set and displayed. The controller and swapping mechanism can be integrated with the user set or with the resources of the service provider and their functionality can reside in software.
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This is a continuation of application Ser. No. 07/576,869, filed Sept. 4, 1990, now abandoned, which in turn is a continuation of U.S. patent application Ser. No. 07/356,914 filed May 23, 1989, now abandoned.
This invention relates to protective hoods and in particular to a protective hood for protecting an individual from the effects of smoke and fire in a fire related emergency.
It is known to provide a protective hood in the form of a bag of heat resistant plastics material which may be used in the event of a fire related emergency to protect an individual from the effects of smoke and fire. Such protective hoods may be pulled over the head of the individual and provide a limited volume of clean, smoke-free air which may suffice to sustain the individual whilst they attempt to escape from the fire related emergency. Such hoods may suitably be used in fire related emergencies in confined spaces, such as hotels, factories, homes, vehicles, ships and aircraft. The limited amount of clean air may be provided by means of suitable filters or by compresses oxygen or air supplies to the hood.
However, such hoods tend to transmit and absorb heat from the fire so that the individual's head is not protected from the effects of heat, for example discomfort, burns and the like.
It is known to provide such hoods with a metal coating to reflect heat and reduce absorption. Such coatings may comprise a layer of gold, silver and aluminum. However, it has been found that some coatings tend to be dislodged from the heat resistant plastics material under the conditions to which they are exposed in a fire related emergency. Furthermore, some metals tend to be attacked by the noxious gases to which they are exposed in a fire related emergency and may become opaque.
BRIEF SUMMARY OF THE INVENTION
Thus according to the present invention there is provided a protective hood for protecting an individual from the effects of smoke and fire in a fire related emergency, comprising a high temperature resistant plastics material having a layer of titanium on at least a part of its outer surface.
Preferably, the plastics material is a thermoset plastics material such as polyimide, for example Upilex (trademark) or Kapton (trademark). Preferably, at least a part of the plastics material is transparent to visible radiation.
Preferably, the hood has a layer of fluoropolymer on at least a part of its inner surface. The fluoropolymer may be fluoroethylene polymer (FEP) or perfluoroalkoxy polymer (PFA).
The fluoropolymer may be in the form of a layer 10 to 40 micrometers thick. The plastics material may be in the form of a film 25 to 75 micrometers thick.
The layer of titanium is preferably sufficiently thick to provide the required reflection and transmission properties for heat, but if the hood is used to cover the eyes of the individual, the layer of titanium which covers the eyes must still be sufficiently transparent to visible radiation to provide sufficient visibility for the individual. This may be achieved by using a layer of titanium of different thicknesses at different parts of the hood. The titanium may be a layer several hundred angstroms thick, that is between 100 and 1000 angstroms thick. The titanium may be between 50 and 200 mg per square meter of hood material, preferably between 100 and 150 mg per square meter. The titanium may be applied by sputtering. The hood material may have a transmittance for electromagnetic radiation of between 10% and 40%, preferably between 15 and 25% at 620 nanometers. Preferably, the hood material has about a 70% rejection of infra red radiation.
The present invention may also be used in the form of a cloak or other garment which may be placed over part or all of the body of the individual.
The present invention may be used in the form of a visor on a protective mask or in the form of shield which may be used in a fire related emergency.
Also according to the present invention there is provided an emergency breathing apparatus comprising a hood as hereinbefore described and having suitable filters or a breathable gas supply to provide a wearer of the hood with a limited volume of clean, smoke-free breathable gas which may suffice to sustain the individual whilst they attempt to escape from the fire related emergency. The breathable gas supply may be an independent compressed oxygen-containing gas supply.
According to the present invention there is also provided a method of protecting an individual from the effects of smoke and fire in a fire related emergency comprising placing a protective hood over a part or all of the body of the individual, the hood comprising a high temperature resistant plastics material having a layer of titanium on at least a part of its outer surface.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will now be described by way of example only with reference to the accompanying drawings wherein
FIG. 1 is a perspective view which represents a protective hood according to the present invention;
FIG. 2 is an enlarged cross-sectional view of a seam, part of a protective hood according to the present invention;
FIG. 3 is a top plan view of the apparatus used for testing the flame resistance of a protective hood according to the present invention;
FIG. 4 is a side elevational view of the apparatus shown in FIG. 3;
FIG. 5 is a side elevational view of the apparatus used for testing the resistance to molten drops of nylon on a protective hood according to the present invention;
FIG. 6 is a top plan view of the apparatus shown in FIG. 5, and
FIG. 7 is a cross-sectional schematic view of the apparatus used to test the chemical resistance of material used to fabricate protective hoods according to the present invention.
DETAILED DESCRIPTION
In FIG. 1, a protective hood 1 according to the present invention comprises Kapton having a layer of titanium on its outer surface 2 and a layer of fluoropolymer on its inner surface 3. The hood has a suitable neck seal 4 which allows the hood to be pulled over the head of an individual (not shown) in a fire related emergency and forms a seal with the neck (not shown) to prevent the ingress of smoke and fumes. The hood is fabricated by joining suitably shaped pieces of Kapton film at suitable seams 5 by heat and pressure welding. The hood is provided with filters 6 to allow the individual to breath clean, smoke-free air for a limited period whilst wearing the hood.
In FIG. 2 part of a hood 1 according to the present invention is shown in cross-section with an inner surface 3 adjacent to the head of an individual (not shown) and an outer surface 2 adjacent to a source of heat or fire (not shown). The hood 1 comprises three layers, an inner layer of fluoroethylene polymer 13, 25 micrometers thick, a layer of Kapton film 14, 50 micrometers thick and an outer layer of sputtered titanium 15 several hundred angstroms thick. FIG. 2 also shows a seam 5 of two pieces of the Kapton joined to form the hood so that the inner (fluoroethylene polymer) layers 13 are bonded together to provide a gas-tight seal.
Prototype hoods without filters fabricated from material comprising fluoroethylene polymer, 25 micrometers thick; Kapton, 50 micrometers thick and titanium were subjected to a flame exposure test. The titanium was sputtered onto and Kapton by a DC magnetron sputtering process with argon partial pressure. The amount of titanium on the Kapton was measured by standard wet ashing analysis to be 116 milligrams of titanium per square meter which by calculation, is believed to be equivalent to a thickness of about 255 angstroms. FIGS. 3 and 4 show the apparatus used for the flame exposure test. A hood 30 according to the example was supported on a metal head-shaped holder 31 called a Sheffield head. The hood 30 contained air 35. The Sheffield head 31 was held on a support 32 which was adjustable. Six burners 33 were used to produce a large diffuse propane flame 34 using a propane supply of 13 liters (NTP) per minute at 0.25 barg. These burners 33 produced a flame 34 with a temperature maximum of 915° C. to 920° C. The smoke hood 30 was positioned 250 mm above the burners. The burners 33 had adjustable height for this purpose. The hood 30 was passed through the flame 34 from the burners 33 at a traverse rate of 100 mm/s giving a flame contact time of 5 to 6 seconds. The heat flux in the flame was about 40 Kw/m 2 . The main areas of the hoods and the seams were exposed in separate tests by changing the position of the hood 30 on the Sheffield head 31. A limited number of more severe tests were undertaken by passing the hood more than once through the flame and by using a larger flame.
The titanium coated Kapton FEP of the hood showed no significant effect of the flame 34 after a number (up to three) passes through the flame. Some particulate matter (soot) was deposited on the surface but was easily wiped off. There was no obvious attenuation in the transparency of the hood material, in fact the material appeared more transparent after the flame tests.
The seams of the hood withstood contact with the flame 34 when the hood 30 was passed once through the flame in both horizontal and vertical orientation, i.e. seam facing down towards the flame 34. In view of this lack of damage, a limited number of more severe tests were carried out in which a hood was passed repeatedly through the flame. The hood resisted a single pass and also a second pass, 2 minutes after the first, and the seam only started to fail after a third pass. A limited number of tests were also undertaken with a larger propane flame (propane supply at 1.25 bar and 27 liters (NTP)/minute). The hood resisted two passes through the larger flame and the seam only started to fail in areas of high stress (hoods were a tight fit on the Sheffield head) during the third pass.
Prototype hoods without filters fabricated from material comprising FEP, 25 micrometers thick; Kapton, 50 micrometers thick and titanium, 116 milligrams per square meter were also subjected to molten drop tests. FIGS. 5 and 6 show the apparatus used for this test. A hood 50 according to the example was supported on a rubber head-shaped holder 51 called a Sheffield head. The Sheffield head 51 was held on a support 52 which was adjustable. A gas burner 53 on a swivel mounting 54 was mounted above the hood 50. The gas burner produced a flame 59 150-170 mm long with a temperature of about 1050° C. using commercial grade propane gas at 1 bars, 1.2 liters (NTF) per minute. A piece of nylon 11 tubing 55 was held on a support 58 500 mm above the hood 50. The swivel mounting 54 was pivotable about a pivot 56 and a stop 57 prevented the burner from being moved closer than 65 mm to the nylon tubing 55. The nylon 11 tube 55 had a length of 10 mm, an outside diameter of 2.5 mm, internal diameter of 1.7 mm, a melting point of 170° C. and contained 11% butylbenzene sulphonamide plasticizer. It also had a Melt Flow Index at 230° C., 2.16 Kg of 11 g/10 min, and Melt Flow Index at 190° C., 2.16 Kg of 1.8 g/10 min.
During the test, the burner 53 produced a flame 59 which melted the nylon tube 55 and caused burning drops of nylon to fall onto the hood 51. The drops typically burned for about 4 to 8 seconds. Both the main area of the hood and the seams were tested separately. The tests showed that the drops burned for several seconds before extinguishing without causing an damage to the hood material. The hoods were not significantly distorted or penetrated by the molten drops. When cool the drops were easily removed from the hood leaving an undamaged surface.
Samples of titanium coated plastics materials were evaluated for resistance to various noxious gases which might be expected to be present in the atmosphere of a fire related emergency. For comparison, samples of stainless steel coated polyester were also assessed. The effects of the various chemicals were assessed visually and by the effect on optical properties (% transmittance of different incident electromagnetic radiation wavelengths using a Perkin Elmer Lambda 9 UV/VIS/NIR Spectrometer). The apparatus used for exposing the samples to the noxious gas is shown schematically in FIG. 7. The samples 70 of material were placed in a polypropylene exposure vessel 71 through which a stream of gas 72 was passed. The gas 72 comprised a mixture of concentrated noxious gas 73 and air 74 which were premixed and preheated in a preheating vessel 75. Both the preheating vessel 75 and the exposure vessel 71 were kept at a constant temperature (100° C.) in a thermostatically controlled water bath 76.
The samples 70 were exposed for 30 minutes at 100° C. to humid and dry test atmospheres separately. Humid conditions were obtained by passing the air through a water-filled Drechsel bottle 77 fitted with a mist trap and corresponded to approximately 90% relative humidity. Dry conditions were obtained by replacing the Drechsel bottle with a drying tower and passing the air through the drying tower which contained, for example, phosphorous pentoxide and corresponded to less than 5% relative humidity.
The samples 70 were exposed to test atmospheres on one face only (the metal coated side where applicable) the rear face being protected from exposure by taping the samples onto a sheet of PTFE (now shown).
The following noxious gases were used separately, all at 1000 vapor parts per million: hydrogen chloride, hydrogen cyanide, hydrogen fluoride, ammonia, nitrogen dioxide, and sulphur dioxide. The samples were also exposed to all these gases sequentially in the order given in the tables. The results are tabulated in Tables 1 to 11.
Tables 1 and 2 show comparative results for stainless steel coated polyester. Tables 3 and 4 show results for titanium coated polyester. The stainless steel and titanium were sputtered onto the polyester by a DC magnetron sputtering process with argon partial pressure. The polyester was 142 gauge. Table 5 shows the results for the same material as was used for the flame tests, that is FEP 25 micrometers thick, Kapton 50 micrometers thick and 116 milligrams of titanium per square meter. This sample had a transmittance of 19% at 620 mm and a similar sample had a transmittance of 21% of 620 mm, measured using the Lambda 9 spectrometer. Tables 6 to 11 inclusive show results for various titanium coated Kapton/FEP samples with ammonia and hydrogen fluoride. The thickness of the titanium for the samples in Tables 6 to 11 was measured on-line by an optical monitor within the sputtering machine at 620 nanometer wavelength and is referred to as %T which is the percentage of energy transmitted at 620 nanometers.
The stainless steel coated materials were affected only by hydrogen fluoride and hydrogen chloride. The film damage was only just discernable visually but the transmittance properties in Tables 1 and 2 show an increase in transmittance indicative of attack of the stainless steel.
Titanium coated polyester showed no damage from any of the gases except hydrogen fluoride. Some very slight visual damage was discernable with hydrogen fluoride and the results in Tables 3 and 4 show an increase in transmittance after exposure to hydrogen fluoride, indicative of attack. Whilst these results show the chemical resistance of titanium, polyester would not be a suitable plastics material according to the present invention.
Titanium coated Kapton/FEP showed no visible sign of attack by any of the gases but the transmittance properties shown in Table 5 show that there was slight attack by hydrogen fluoride, resulting in a very small increase in transmittance.
Similar results are shown in Tables 6 to 11 which show that hydrogen fluoride caused slight metallic layer damage to the titanium coated Kapton/FEP but ammonia did not.
The examples given show that the protective hood according to the present invention exhibits good resistance to the conditions which may be present in a fire related emergency, that is, good flame resistance, good resistance to molten, burning plastics material and good resistance to noxious gases.
TABLE 1______________________________________EXPOSURE OF STAINLESS STEEL COATEDPOLYESTER TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 47 51 51Hydrogen chloride (humid) 51 57 57Hydrogen fluoride (humid) 47 50 54Sulphur dioxide (humid) 47 51 51Nitrogen dioxide (humid) 47 53 54Hydrogen cyanide (humid) 48 50 53All gases sequentially 57 60 60(humid)______________________________________
TABLE 2______________________________________EXPOSURE OF STAINLESS STEEL COATEDPOLYESTER TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 29 31 32Hydrogen chloride (humid) 35 35 36Hydrogen fluoride (humid) 35 35 35Sulphur dioxide (humid) 30 30 33Nitrogen dioxide (humid) 31 32 35Hydrogen cyanide (humid) 31 30 36All gases sequentially 37 38 37(humid)______________________________________
TABLE 3______________________________________EXPOSURE OF TITANIUM COATEDPOLYESTER TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 47 49 49Hydrogen chloride (humid) 49 47 48Hydrogen fluoride (humid) 59 58 59Sulphur dioxide (humid) 49 47 49Nitrogen dioxide (humid) 50 47 50Hydrogen cyanide (humid) 50 47 48All gases sequentially 64 61 63(humid)______________________________________
TABLE 4______________________________________EXPOSURE OF TITANIUM COATEDPOLYESTER TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 30 30 32Hydrogen chloride (humid) 30 29 32Hydrogen fluoride (humid) 35 35 37Sulphur dioxide (humid) 30 30 30Nitrogen dioxide (humid) 31 30 31Hydrogen cyanide (humid) 30 29 29All gases sequentially 39 36 37(humid)______________________________________
TABLE 5______________________________________EXPOSURE OF TITANIUM COATED KAPTON/FEPTO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 19 23 23Hydrogen chloride (humid) 19 22 23Hydrogen chloride (dry) 19 22 25Hydrogen fluoride (humid) 22 26 28Hydrogen fluoride (dry) 20 23 26Sulphur dioxide (humid) 19 22 25Sulphur dioxide (dry) 19 23 24Nitrogen dioxide (humid) 20 24 26Nitrogen dioxide (dry) 20 24 25Hydrogen cyanide (humid) 19 23 24Hydrogen cyanide (dry) 19 22 23Ammonia (humid) 19 22 23Ammonia (dry) 19 23 25All gases sequentially 21 25 25(humid)______________________________________
TABLE 6______________________________________EXPOSURE OF TITANIUM COATED KAPTON/FEP(43.6% T) TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 29 28 34Hydrogen fluoride (humid) 30 29 34Ammonia (humid) 22 24 28Sequentially exposed to 28 26 29both gases (humid)______________________________________
TABLE 7______________________________________EXPOSURE OF TITANIUM COATED KAPTON/FEP(47.8% T) TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 36 35 41Hydrogen fluoride (humid) 38 34 38Ammonia (humid) 37 35 39Sequentially exposed to 38 35 40both gases (humid)______________________________________
TABLE 8______________________________________EXPOSURE OF TITANIUM COATED KAPTON/FEP(70.7% T) TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 50 52 60Hydrogen fluoride (humid) 58 64 70Ammonia (humid) 49 51 58Sequentially exposed to 57 62 68both gases (humid)______________________________________
TABLE 9______________________________________EXPOSURE OF TITANIUM COATED KAPTON/FEP(34.7% T) TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 19 20 22Hydrogen fluoride (humid) 25 25 26Ammonia (humid) 22 22 26Sequentially exposed to 32 32 35both gases (humid)______________________________________
TABLE 10______________________________________EXPOSURE OF TITANIUM COATED KAPTON/FEP(15.1% T) TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 9 10 13Hydrogen fluoride (humid) 14 14 16Ammonia (humid) 8 9 12Sequentially exposed to 14 13 16both gases (humid)______________________________________
TABLE 11______________________________________EXPOSURE OF TITANIUM COATED KAPTON/FEP(13.5% T) TO NOXIOUS GASES % Transmittance of electromag- netic radiation at wavelengthGas 600 nm 1200 nm 2000 nm______________________________________None 7 9 11Hydrogen fluoride (humid) 12 12 15Ammonia (humid) 9 10 13Sequentially exposed to 12 12 14both gases (humid)______________________________________
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A protective hood (1) for protecting an individual from the effects of fire and smoke in a fire related emergency comprises a high temperature resistant plastics material (14) having a layer of titanium (2, 15) on at least a part of its outer surface. Preferably the plastics material has a layer of fluoropolymer (3, 13) on its inner surface and the titanium is sufficiently thick to provide the required heat reflective properties, but is transparent to visible light.
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FIELD OF THE INVENTION
[0001] The present invention relates generally to electric power distribution systems. More particularly, the invention relates to such electric power distribution systems that utilize loop sectionalizing for improvement in responding to short circuits on distribution lines.
BACKGROUND OF THE INVENTION
[0000] A. General
[0002] Reference is frequently made herein to circuit breakers, sectionalizers, and reclosers. All of these devices are designed to switch distribution circuits on and off by opening or closing switches therein. Typically modern breakers, sectionalizers, and reclosers do not contain any means to determine when or if they should open or close. Instead these devices are attached to control devices which measure power system currents and/or voltages, and send signals to the reclosers, sectionalizers, and circuit breakers to open and close. The methods described below, which decide when to open and close the circuit breakers, sectionalizers, and reclosers, are typically implemented in these control devices. The usual practice in the art is to refer to a device that controls a circuit breaker as a protective relay. Similarly, a device that controls a recloser is typically referred to as a recloser control and a device that controls a sectionalizer is typically referred to as a sectionalizer control.
[0003] Thus, even though reclosers, sectionalizers, and breakers are frequently referred to herein as measuring current, sensing short circuit current, measuring voltage, and sensing when a line is energized or deenergized, it will be readily apparent to those skilled in the art that the control device associated with each circuit breaker, recloser, or sectionalizer is actually performing the measurements, detecting short circuits or line energization states, and making the decision to open and close the connected recloser, sectionalizer, or circuit breaker. Thus, when a circuit breaker, recloser, and/or sectionalizer is referred to herein, it means the combination of recloser and recloser control, sectionalizer and sectionalizer control, and circuit breaker and protective relay.
[0000] B. Power Distribution Systems with Radial Distribution Lines
[0004] Electric power distribution typically occurs at voltages in the range 4 kV to 35 kV. Historically, distribution lines were connected radially from distribution substations to loads. The prior art example of FIG. 1 illustrates a system 21 with a single distribution line 20 feeding several loads, Load 1 through Load 4 , from a distribution substation 22 . Usually several distribution lines radiate from the substation 22 , but for simplicity, only one distribution line 20 is shown in FIG. 1 .
[0005] A short circuit on such a radial line typically causes a power outage for all connected loads in a radial distribution system. Inside the substation 22 is a circuit breaker 24 that helps protect the distribution line 20 from short circuits. If a short circuit occurs anywhere on the line, then large currents will begin to flow from the substation 22 to the short circuit on the distribution line 20 . Over-current detecting equipment, called protective relays, will detect the large current and will signal the circuit breaker 24 to open. When the circuit breaker 24 opens, the distribution line 20 is disconnected from the power source within the substation 22 . This interrupts power to all of the loads, Load 1 through Load 4 , connected to the radial distribution line 20 . The loads then remain without power until a line crew travels to the site of the short circuit, repairs the short-circuited conductors, and then closes the circuit breaker 24 . The duration of such a power outage is typically several hours.
[0006] Power can be restored to the loads faster after temporary short circuits by reclosing the circuit breaker. Still referring to FIG. 1 , many short circuits are transient in nature. If the short-circuited line is disconnected from the power source by the circuit breaker 24 , temporary short circuits can be self-healed. When the circuit breaker 24 recloses, the short circuit will be gone, and power will be restored to the loads immediately without the need to dispatch a line crew to repair the short circuit. This returns power to the loads faster, in a matter of seconds instead of hours.
[0007] Of course, there is no guarantee that the short circuit is temporary, and it may still be present when the circuit breaker closes. In that case, the circuit breaker 24 is again opened, and may be reclosed one or more additional times testing to see if the short circuit has self-healed. If the short circuit goes away, then the breaker remains closed. If the short circuit is permanent, then the breaker 24 opens a predetermined number of times, waiting a predetermined time between each closing, and then opens a final time and remains open. Again all of the connected loads are without power until a line crew locates and repairs the short circuit, and the circuit breaker is closed. This can take several hours. Since some portion of faults are temporary, reclosing of the circuit breaker 24 decreases the chances that a load will be without power for several hours, and increases the chance that the load will be without power for only a few seconds.
[0008] Sectionalizers and reclosers can be used to limit the size of the power outages caused by permanent short circuits. Some distribution lines are constructed with switches along the length of the line, as shown in FIG. 2 . In particular, in FIG. 2 , a system 23 with a sectionalizer switch 26 allows power to be restored to some loads faster. First, the operation of sectionalizer switches will be discussed, and then the operation of line reclosers will be discussed. Both reclosers and sectionalizers historically have the ability to measure the current flowing through the switch, and the voltage at least on one side of the switch. When the voltage is measured on only one side of the switch (the usual case), it is measured on the side of the switch closer to the sub-station 22 or to the power source.
[0009] The switch 26 , also marked S, in FIG. 2 is a sectionalizer switch. It measures current flowing through the switch, and the voltage on the left (substation or power source) side of the switch. If a short circuit occurs between the substation 22 and the sectionalizer switch 26 , the system of FIG. 2 behaves the same as the system of FIG. 1 . If a short circuit 28 occurs between the sectionalizer switch 26 and the end of the distribution line 20 then the system of FIG. 2 acts differently than the system of FIG. 1 . This short circuit 28 is said to be “down stream” of the sectionalizer 26 .
[0010] The short circuit causes a large current to flow from the power source in the substation 22 , through the substation circuit breaker 24 , along the distribution line 20 , through the sectionalizer switch 26 , and to the short circuit 28 . The sectionalizer 26 senses the large current flow, and then “knows” that the short circuit 28 is down stream from the sectionalizer location. If the short circuit location were upstream of the sectionalizer location, then the sectionalizer switch 26 would not have detected the large current.
[0011] As with the system 21 of FIG. 1 , the circuit breaker 24 in the substation 22 opens and removes power from the distribution line 20 , all of the connected loads, Load 1 through Load 4 , and from the short circuit 28 . This causes the voltage along the distribution line 20 to drop from several thousand volts to substantially zero volts. The sectionalizer 26 senses the absence of voltage, and “knows” that the substation breaker 24 has opened. The substation breaker 24 may be programmed to test several times for a temporary short circuit before finally opening and staying open if the short circuit 28 is permanent. The sectionalizer switch 26 counts each time the substation breaker 24 closes and opens. The sectionalizer 26 does this by sensing the short circuit current flowing through the sectionalizer switch when the substation breaker 24 closes, and senses the absence of voltage when the substation breaker 24 opens.
[0012] The sectionalizer switch S is programmed to open during one of the “open-intervals” of the substation breaker 24 . This open-interval is the time when the substation breaker 24 , or any device, is open. During some pre-determined open interval, the sectionalizer opens.
[0013] When the substation breaker 24 recloses with the sectionalizer switch open, there will be no large current flow because the short circuit 28 has been isolated from the power source by the open condition of the sectionalizer switch 26 . The circuit breaker 24 will then remain closed. In other words, the sectionalizer switch 26 made the permanent short circuit 28 shown in FIG. 2 appear to be a temporary short circuit. The result is that after the substation breaker 24 closes, power is restored to Load 1 and Load 2 after just a few seconds, even though the short circuit 28 is permanent. Only the customers at Load 3 and at Load 4 will experience an extended power outage while the line crew searches for and repairs the short circuit 28 . After the short circuit is repaired, the sectionalizer switch 26 is closed, and power returns to Load 3 and Load 4 . This is an improvement over the system of FIG. 1 where a permanent short circuit caused an extended power outage for all of the loads.
[0014] FIG. 3 illustrates a system 27 with a recloser 30 , also marked R, in place of the sectionalizer 26 in the system 23 of FIG. 2 . This line recloser 30 further reduces the size and length of a power outage. For short circuits between the substation circuit breaker 24 and the recloser 30 , the system 27 of FIG. 3 operates the same as the system 21 of FIG. 1 . For short circuits downstream of the recloser 30 , the systems operate differently. The short circuit 28 shown in FIG. 3 will cause a large current to flow from the substation 22 through the recloser 30 and to the short circuit 28 . The recloser 30 senses the large current and opens quickly. The substation circuit breaker 24 is programmed to open with a longer time delay than the recloser 30 , so the recloser opens and the substation breaker remains closed. This removes power from loads Load 3 and Load 4 , but power to Load 1 and Load 2 is only degraded while the large current is flowing, and is completely restored when the recloser 30 opens. Typically the recloser will open in less than one second, so the short circuit 28 in FIG. 3 will only cause a power degradation lasting less than one second for Load 1 and for Load 2 . The recloser 30 may be programmed to reclose after some time to test if the short circuit 28 is temporary. If the short circuit is temporary, then Load 3 and Load 4 will be without power for only a few seconds.
[0015] If the short circuit is permanent, then the recloser 30 will open and close a predetermined number of times, then open one final time and remain opened. Load 3 and Load 4 will remain un-powered for several hours while the line crew searches for and repairs the short circuit. Load 1 and Load 2 will experience a power degradation lasting less than one second each time the recloser 30 closes to test if the short circuit 28 still exists. This is an improvement over the system 23 of FIG. 2 where Load 1 and Load 2 experienced a power outage lasting several seconds.
[0000] C. Power Distribution Systems with Looped Distribution Lines
[0016] A system 31 in FIG. 4 shows a further improvement over the radial distribution systems of FIGS. 1-3 with looped distribution circuits providing rapid power restoration following permanent short circuits. The previously considered systems 21 , 23 and 27 in FIGS. 1-3 involved radial distribution lines. The system 31 of FIG. 4 involves a looped distribution line 32 . The term “looped” means that power can be fed to any of the loads, Load 1 through Load 6 , from either direction. This system 31 is normally operated in the state shown in FIG. 4 . In the normal operational state of the system shown in FIG. 4 , reclosers R 1 , R 2 , R 4 and R 5 are closed, and recloser R 3 is open. Recloser R 3 is normally open because if all of the reclosers were closed, it would be difficult to control the amount of power flowing through the looped line, especially if the two circuit breakers 24 and 25 are in different substations.
[0017] Reclosers R 1 , R 2 , R 4 and R 5 can sense current flowing through them, and can also measure or at least sense the presence or absence of voltage on at least one side; typically the side closer to the substation 22 or the power source. Recloser R 3 can measure current and can measure voltage on both sides of itself. Methods of measuring current and measuring or sensing voltage are, of course, well known in the art.
[0018] Recall that the system 27 shown in FIG. 3 performed very well for the short circuit 28 shown in FIG. 3 . Load 1 and Load 2 experienced power degradation lasting less than one second even for a permanent fault. However, if the permanent short circuit 28 were upstream of the recloser 30 in FIG. 3 , then all four loads would experience an extended power outage. So, the performance of system 27 depends on the location of the short circuit 28 . The system 31 shown in FIG. 4 removes the dependence on short circuit location. This system performs substantially equally well regardless of where the short circuit exists or occurs.
[0019] For example, FIG. 5 shows a permanent short circuit 28 upstream of recloser R 1 . If the system 31 were not looped, then this short circuit would result in an extended power outage for loads Load 1 , Load 2 , and Load 3 , because the substation breaker 24 would open and would de-energize the line serving all of those loads.
[0020] FIG. 6 and FIG. 7 show how the system 31 limits the size and duration of the outage for the short circuit 28 shown in FIG. 5 . The short circuit 28 causes a large current to flow from the power source inside the substation 22 to the short circuit 28 . The substation circuit breaker 24 opens for a pre-determined time, causing a temporary power outage for loads Load 1 , Load 2 and Load 3 . The substation breaker 24 typically tests the line 32 several times to see if the short circuit 28 is temporary. If the short circuit is temporary, then when the circuit breaker 24 closes the short circuit 28 will no longer exist, and the system 31 will return to the state shown in FIG. 4 . If the short circuit 28 is permanent, the substation breaker 24 opens and closes a predetermined number of times, i.e., the breaker tests the line for a temporary short circuit, and then breaker 24 remains open. Reclosers R 1 and R 2 sense that the line connected to them is de-energized for an extended time. Reclosers R 1 and R 2 are both programmed to take specific action when they sense that the line 32 is de-energized for an extended time (e.g. longer than some predetermined time). Recloser R 1 is programmed to open following a predetermined time delay after the line becomes de-energized. Recloser R 2 is programmed to reconfigure to protect the section of line 32 between reclosers R 2 and R 1 . Recloser R 2 was previously configured to protect the section of line between reclosers R 2 and R 3 because the power source or substation 22 was to the left of recloser R 2 . Recloser R 3 is programmed to close after a predetermined time when it senses that the line 32 connecting to either side of recloser R 3 is de-energized. After the substation breaker 24 has finished testing the line for a temporary short circuit and breaker 24 is open, and all of the reclosers perform their programmed tasks, the system 31 is as shown in FIG. 7 .
[0021] Notice that only Load 1 connected between recloser R 1 and the substation breaker 24 experiences a prolonged power outage. Load 2 and Load 3 would have also experienced a prolonged power outage if the system were radial. However since the system 31 is looped, Load 2 and Load 3 are without power only for a few tens of seconds while circuit breaker 24 is open and while the predetermined time delays elapse before recloser R 1 opens, recloser R 2 reconfigures, and recloser R 3 closes. A timeline for the entire process is shown in the bottom portion of FIG. 7 .
[0022] Now assume a permanent short circuit 28 occurs between reclosers R 1 and R 2 , as shown in FIG. 8 . The permanent short circuit causes a large current to flow from the substation power source through the circuit breaker 24 and through recloser R 1 to the short circuit 28 . Recloser R 1 is programmed to open with less delay than the substation breaker 24 , so recloser R 1 opens and circuit breaker 24 remains closed. I.e., when recloser R 1 opens, the short circuit current ceases, so the substation breaker 24 does not open. Recloser R 1 closes several times to test the line 32 for a temporary short circuit. In this example, the short circuit 28 is permanent, so recloser R 1 eventually opens permanently. It opens before the substation breaker 24 is programmed to open, so the substation breaker remains closed.
[0023] The system 31 is now in the state shown in FIG. 9 . Load 2 and Load 3 are de-energized. Recloser R 2 performs exactly as in the previous example. If it senses that the line connected to it is de-energized for an extended time (e.g. longer than some predetermined time), it reconfigures to protect the section of line 32 between reclosers R 1 and R 2 . Recloser R 3 also acts exactly the same as it did in the previous example. It reconfigures to protect the section of line between reclosers R 2 and R 3 , and closes, which brings the system 31 to the state shown in FIG. 10 .
[0024] The permanent short circuit now causes a large current to flow from the substation, through reclosers R 5 , R 4 , R 3 , and R 2 , causing a temporary power degradation to Load 2 , Load 3 , Load 4 , Load 5 , and Load 6 . When recloser R 2 senses a large current after reconfiguring to protect the line between reclosers R 2 and R 1 , it opens very rapidly, and remains open. It does not attempt to reclose. Because recloser R 2 opens very rapidly, reclosers R 3 , R 4 and R 5 and circuit breaker 25 all remain closed.
[0025] The system 31 now resides in the state shown in FIG. 11 . Notice that the permanent short circuit 28 between reclosers R 1 and R 2 only caused an extended power outage for the Load 2 connected between reclosers R 1 and R 2 . Load 1 experienced one to several temporary power degradations as recloser R 1 was testing the line for a temporary short circuit. Load 3 experienced one to several temporary power outages lasting several seconds as recloser R 1 was testing for a temporary short circuit, and then experienced a longer power outage as reclosers R 2 and R 3 reconfigured. Finally Load 3 experienced a temporary power degradation when recloser R 3 closed, causing short circuit current to flow through reclosers R 2 , R 3 , R 4 and R 5 . Load 4 , Load 5 and Load 6 all experienced a temporary power degradation lasting less than one second when recloser R 3 closed. If the substation breakers 24 and 25 are located in the same substation 22 , or in substations electrically close to each other, then Load 4 , Load 5 and Load 6 may also experience temporary degradations in power due to the initial short circuit, and when recloser R 1 tests the line for a temporary short circuit. A timeline for the entire process is shown in the bottom portion of FIG. 11 .
[0026] In our final example of this configuration, assume a permanent fault 28 between reclosers R 2 and R 3 , as shown in FIG. 12 . This short circuit causes large short circuit current to flow through the substation breaker 24 and reclosers R 1 and R 2 . Recloser R 2 is programmed to open with less delay than the substation breaker 24 and recloser R 1 , so recloser R 2 opens. The short circuit current ceases, so the substation breaker 24 and recloser R 1 remain closed. Recloser R 2 tests the line 32 several times for a temporary short circuit, and finally opens permanently. Each time recloser R 2 opens, it does so before recloser R 1 and the substation breaker 24 react, so each time recloser R 1 and the substation breaker 24 remain closed.
[0027] The system 31 is now in the state shown in FIG. 13 . As with the previous examples, recloser R 3 is programmed to close after it senses either line connected to it is de-energized. When recloser R 3 closes, a large short circuit current flows through reclosers R 3 , R 4 and R 5 and circuit breaker 25 . Recloser R 3 is programmed to open and not reclose in response to short circuit current. After recloser R 3 opens, the system reverts to the state shown in FIG. 13 . Notice that Load 1 and Load 2 only experienced one to several temporary power degradations while recloser R 2 tested the line for a permanent fault. Load 4 , Load 5 and Load 6 experienced one temporary power degradation when recloser R 3 closed. Load 3 is the only load that experiences an extended power outage. A timeline for the entire process is shown in the bottom portion of FIG. 13 .
[0028] All three of the previous examples could have included short circuits on the lower half of the distribution loop, and the results would have been similar except that breaker 25 , reclosers R 3 , R 4 , and R 5 , and loads Load 4 , Load 5 , and Load 6 would have been involved.
[0029] Each of the reclosers in looped distribution lines has a set of rules for operation. From the preceding discussion, it might seem that each recloser performs different functions depending on the location of the short circuit. However, each recloser follows a certain preprogrammed sequence of actions regardless of the location of the short circuit. FIG. 14 shows a flow chart of the preprogrammed sequence of actions that are taken by recloser R 3 , FIG. 15 shows a flow chart of the preprogrammed sequence of actions that are taken by reclosers R 2 and R 4 and FIG. 16 shows a flow chart of the preprogrammed sequence of actions that are taken by reclosers R 1 and R 5 .
[0030] Each flowchart, FIGS. 14 through 19 , has a start and end bubble. The methods move from the end bubble or from anywhere in the flowchart to the start bubble when the scheme is reset or restarted. The reset or restart occurs after the permanent short circuit is repaired or when an operator determines the method should be reset. The reset or restart can be manual, such as when a person issues a reset signal or command to the recloser, or automatic, such as when the reclosers reset themselves when they detect some sufficient condition.
[0031] The above-described operation of recloser R 3 is summarized in FIG. 14 . After starting at bubble 40 , recloser R 3 determines if line 32 is de-energized for a predetermined time on one side only at decision block 41 . If the line is energized on both sides of recloser R 3 , or de-energized on both sides of recloser R 3 , it continues to measure voltage on both side of recloser R 3 until line 32 is de-energized on one side only for some predetermined time. If the line is de-energized on one side only for a predetermined time, the process proceeds to decision block 42 to determine if line 32 is de-energized to the right of recloser R 3 . If so, recloser R 3 configures to protect line 32 to the right of recloser R 3 at block 43 . If not, recloser R 3 configures to protect line 32 to the left of recloser R 3 at block 44 . In either situation, recloser R 3 closes at block 45 . It then continues to sense for short circuit current at decision block 46 . If recloser R 3 detects a short circuit current lasting longer than a predetermined time, recloser R 3 opens at block 47 and the process terminates at end bubble 48 .
[0032] The above-described operation of reclosers R 2 and R 4 is summarized in FIG. 15 . After starting at bubble 50 , reclosers R 2 and R 4 determine if a short circuit current is present on line 32 at decision block 51 . If a short circuit is present, reclosers R 2 and R 4 determine at decision block 52 if the short circuit current lasts longer than a first predetermined time. If not, the process begins again at start bubble 50 . If the short circuit current lasts longer than a predetermined time, then recloser R 2 or R 4 opens at block 58 . Decision block 59 determines if the line has been tested for temporary short circuits more than a predetermined number of times. If it has, then the process ends at block 57 . If the line has been tested for a temporary short circuit less than a predetermined number of times, then the recloser R 2 or R 4 is closed at block 60 and the process continues from the start bubble. If no short circuit current is detected at decision block 51 , then a check is performed to determine if the line is energized at decision block 53 . If the line is not de-energized, i.e., if the line is still energized, then the process continues from the start bubble. If the line is de-energized, then recloser R 2 or R 4 is reconfigured to protect the upstream line, i.e., recloser R 2 or R 4 is reconfigured to protect the line between reclosers R 1 and R 2 or between reclosers R 5 and R 4 . Reclosers R 2 and R 4 again monitor line 32 for a short circuit current that lasts longer than a predetermined amount of time at block 55 . If a short circuit current is detected and lasts longer than the predetermined amount of time, recloser R 2 and/or recloser R 4 open at block 56 and end the process at bubble 57 .
[0033] The above-described operation of reclosers R 1 and R 5 is summarized in FIG. 16 . After starting at bubble 61 , reclosers R 1 and R 5 determine if a short circuit current is present on line 32 at decision block 62 . If a short circuit is present, reclosers R 1 and R 5 determine at decision block 63 if the short current lasts longer than a first predetermined time. If the short circuit current does not last longer than a predetermined time, then the process reverts to the start bubble 61 . If the short circuit lasts longer than a predetermined time, then recloser R 1 or R 5 opens at block 67 . Decision block 68 determines if the line has been tested for temporary short circuits more than a predetermined number of times. If it has, then the process ends at bubble 66 . If the line has been tested for a temporary short circuit less than a predetermined number of times, then recloser R 1 or R 5 is closed at block 69 and the process continues from the start bubble. If short circuit current is not detected at decision block 62 , then recloser R 1 or R 5 determine if the line has been de-energized for longer than a predetermined time at decision block 64 . If the line has not been de-energized for longer than a predetermined time, then the process reverts to start bubble 61 . If the line has been de-energized for a predetermined time, then recloser R 1 or R 5 opens at block 65 , and the process ends at bubble 66 .
[0034] These processes in FIGS. 14-16 are sufficient to reduce the extended power outage to only the section of looped distribution line 32 containing the permanent short circuit 28 . Notice that these processes cover only the function of the reclosers related to controlling the looped distribution line 32 . Each recloser may perform various other functions, such as metering, reporting, etc. These other functions are not shown in FIGS. 14, 15 and 16 .
[0035] A number of problems exist with respect to the present method of controlling looped distribution lines, as represented by FIGS. 14-16 . The method implemented by the processes discussed above has several non-idealities:
A. Permanent short circuits 28 between reclosers R 1 and R 2 , or between reclosers R 2 and R 3 cause a temporary power degradation to Load 4 , Load 5 and Load 6 when recloser R 3 closes. If the system were not configured as a loop, i.e. if recloser R 3 did not connect the top distribution line to the bottom distribution line, then this temporary power degradation would not occur (assuming the looped distribution line terminated in electrically separated substations), or this temporary power degradation would be less severe. In other words, this arrangement decreases the quality of power supplied to the distribution line that does not have the short circuit 28 while it increases the quality of power supplied to the distribution line that does have a short circuit. B. Permanent short circuits 28 between reclosers R 1 and R 2 , or between reclosers R 2 and R 3 , cause added stress on the power system when recloser R 3 closes. This stress includes large short circuit currents that stress transformers, generators, conductors, etc. The added stress also includes decreased voltages that stress many types of connected electrical loads such as motors and electronics. The added stress also includes added wear on recloser R 3 when recloser R 3 must open after closing with a permanent fault between reclosers R 2 and R 3 , and added wear on recloser R 2 when R 2 must open after recloser R 3 closes with a permanent fault between reclosers R 1 and R 2 . C. If the power source in the substation is de-energized, then the distribution line is de-energized. Recloser R 1 responds to this by opening (Blocks 64 and 65 in FIG. 16 ). This is a nuisance because after power is restored to the substation, the loads downstream of recloser R 1 remain de-energized until recloser R 1 is closed, possibly by a manual operation after several hours.
[0039] The shortcomings described are also applicable to the other side of the loop in FIGS. 14-16 , i.e., the side of the loop containing breaker 25 and reclosers R 4 and R 5 .
[0040] There has been a long-felt need for methods or systems that efficiently and effectively reconfigure an electrical power distribution system to provide power to most of the loads upon the occurrence of a short circuit on the distribution line.
[0041] Accordingly, it is a general object of the present invention to provide improved methods and systems that reconfigure a looped distribution line in a manner that continues to supply power to most of the loads when a short circuit occurs.
[0042] Another general object of the present invention is to provide improved methods and systems for sectionalizing a looped distribution line to reduce the stress on the power system and on the power system components when a short circuit occurs.
[0043] Another general object of the present invention is to provide improved methods and systems for sectionalizing a looped distribution line to reduce the unnecessary outages in the distribution power system when no short circuit exists in the distribution power system.
[0044] Yet another object of the present invention is to provide a plurality of preprogrammed switches, with at least some of the preprogrammed switches having at least one unique open interval when responding to a short circuit, such that other preprogrammed switches can determine which preprogrammed switch opened in response to the short circuit.
[0045] A further object of the present invention is to provide a power distribution system and methods in which a normally open preprogrammed switch does not close until an adjacent preprogrammed switch opens when the short circuit is downstream from the adjacent preprogrammed switch.
[0046] A still further object of the present invention is to provide methods for determining which preprogrammed switch opened in response to the occurrence of a short circuit.
BRIEF SUMMARY OF THE INVENTION
[0047] This invention is directed to methods and systems for sectionalizing a looped distribution line, such as from a substation in an electric power distribution system, that supplies electrical power to a plurality of loads and that also reduces the stress on the power system and on the power system components when a short circuit occurs and that also reduces unnecessary temporary outages. The electric power distribution system includes a plurality of preprogrammed switches disposed between at least some of the plurality of loads. The plurality of preprogrammed switches includes a first preprogrammed switch and a fifth preprogrammed switch each disposed in the looped distribution line downstream from said substation, a second preprogrammed switch and a fourth preprogrammed switch each disposed in the looped distribution line downstream from said first and fifth preprogrammed switches and a third preprogrammed switch disposed in the looped distribution line between said second and fourth preprogrammed switches. The third preprogrammed switch is in a normally open condition. All of said preprogrammed switches are programmed to respond to the occurrence of a short circuit in the looped distribution line and to reconfigure the looped distribution line to isolate the short circuit.
[0048] Methods of the present invention include the steps of providing some of the plurality of preprogrammed switches with a unique open interval time for at least one of its open intervals when responding to a short circuit condition on the looped distribution line, determining the length of the unique open interval by at least one of the preprogrammed switches in response to the occurrence of a short circuit, identifying that the short circuit is in a portion of the looped distribution line that is downstream from the preprogrammed switch associated with the determined unique open time interval, and configuring the preprogrammed switch downstream to protect the identified portion of the looped distribution line.
[0049] The step of configuring the next downstream preprogrammed switch may include the steps of immediately opening the second preprogrammed switch upon determining that the short circuit is between the first and second preprogrammed switches, configuring the third preprogrammed switch to protect the line between the second and third preprogrammed switches and closing the third preprogrammed switch. The step of configuring the next downstream preprogrammed switch may also include the steps of immediately opening the fourth preprogrammed switch upon determining that the short circuit is between the fifth and fourth preprogrammed switches, configuring the third preprogrammed switch to protect the line between the fourth and third preprogrammed switches and closing the third preprogrammed switch.
[0050] The step of providing each preprogrammed switch with a unique open time interval may include the steps of providing the preprogrammed switches in the substation with a unique open time interval of time t1, providing the first and fifth preprogrammed switches with a unique open time interval of time t2, with t2 greater than t1, and providing the second and fourth preprogrammed switches with a unique open time interval of time t3, with t3 greater than t2. The step of determining at each preprogrammed switch the length of said open time interval may include the additional steps of determining if the open interval used to test the line for a temporary short circuit is greater than time t1 but less than time t2 and determining if the open interval used to test the line for a temporary short circuit is greater than time t2 but less than time t3.
[0051] Systems in accordance with the present invention may include a plurality of preprogrammed switches disposed between at least some of the plurality of loads, one of the preprogrammed switches being in a normally open condition, some of said plurality of preprogrammed switches programmed to respond to the occurrence of a short circuit in the looped distribution line and to reconfigure the looped distribution line to isolate the short circuit, some of said plurality of preprogrammed switches provided with a unique open time interval for at least one of its open intervals when responding to a short circuit condition on the looped distribution line and at least one of said plurality of preprogrammed switches capable of determining the length of said unique open time interval in response to the occurrence of a short circuit to identify that the short circuit is in a portion of the looped distribution line that is downstream from the preprogrammed switch associated with the determined unique open time interval; whereby the next downstream preprogrammed switch is configured to protect the identified portion of the looped distribution line that is downstream from the preprogrammed switch with the determined unique open interval. The normally open switch may typically determine the amount of time of the unique open time interval.
[0052] Systems may further include a preprogrammed switch disposed adjacently to said normally open preprogrammed switch that immediately opens upon determining that the short circuit is between the adjacent, the normally open preprogrammed switches and the normally open preprogrammed switch configures to protect the line between the adjacent and the normally open preprogrammed switches and the normally open switch closes after the adjacent switch has opened. Systems may further include a first pair of preprogrammed switches disposed at each end of the looped distribution line in the substation, said first pair of preprogrammed switches provided with a unique open time interval of time t1, a second pair of preprogrammed switches disposed next downstream in the looped distribution system from the first pair of preprogrammed switches in the substation, said second pair of preprogrammed switches provided with a unique open time interval of time t2, with t2 greater than t1 and a third pair of preprogrammed switches disposed next downstream in the looped distribution system from the second pair of preprogrammed switches, said third pair of preprogrammed switches provided with a unique open time interval of time t3, with t3 greater than t2. At least one of the preprogrammed switches may determine if the open interval used to test the line for a temporary short circuit is greater than time t1 but less than time t2 and/or determine if the open interval used to test the line for a temporary short circuit is greater than time t2 but less than time t3.
BRIEF DESCRIPTION OF THE DRAWINGS
[0053] The features of the present invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with the further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings, in the figures in which like reference numerals identify like elements, and in which:
[0054] FIG. 1 illustrates a single radial distribution line feeding several loads from a distribution substation;
[0055] FIG. 2 illustrates a sectionalizer switch interposed between some of the loads in the radial distribution line of FIG. 1 ;
[0056] FIG. 3 illustrates a recloser interposed between some of the loads in the radial distribution line in place of the sectionalizer switch of FIG. 2 ;
[0057] FIG. 4 illustrates a plurality of reclosers, with each recloser interposed between respective loads in a looped distribution system;
[0058] FIG. 5 illustrates a short circuit in the looped distribution line of FIG. 4 ;
[0059] FIGS. 6 and 7 illustrate the response of the plurality of reclosers to reconfigure the distribution system in response to sensing conditions on the looped distribution line caused by the short circuit in FIG. 5 ;
[0060] FIG. 8 illustrates a short circuit at a different location in the looped distribution line from that shown in FIG. 5 ;
[0061] FIGS. 9 through 11 illustrate the response of the plurality of reclosers to reconfigure the distribution system in response to sensing conditions on the looped distribution line caused by the short circuit in FIG. 8 ;
[0062] FIG. 12 illustrates a short circuit at a still different location in the looped distribution line from that shown in FIG. 5 or 8 ;
[0063] FIG. 13 illustrates the response of the plurality of reclosers to reconfigure the distribution system in response to sensing conditions on the looped distribution line caused by the short circuit in FIG. 12 ;
[0064] FIG. 14 is a flow chart of a preprogrammed sequence of actions that are taken by a recloser in a looped distribution system;
[0065] FIG. 15 is a flow chart of a preprogrammed sequence of actions that are taken by certain other reclosers in a looped distribution system;
[0066] FIG. 16 is a flow chart of a preprogrammed sequence of actions that are taken by still certain other reclosers in a looped distribution system;
[0067] FIG. 17 is a flow chart of a preprogrammed sequence of actions that are taken by a recloser in a looped distribution system in accordance with the present invention;
[0068] FIG. 18 is a flow chart of a preprogrammed sequence of actions that are taken by certain other reclosers in a looped distribution system also in accordance with the present invention;
[0069] FIG. 19 is a flow chart of a preprogrammed sequence of actions that are taken by still certain other reclosers in a looped distribution system also in accordance with the present invention; and
[0070] FIG. 20 illustrates a three recloser embodiment of a looped distribution system with each recloser interposed between respective loads.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0071] The shortcomings of prior art looped distribution systems described above in Paragraphs 0035-0036 can be overcome by facilitating the reclosers to communicate with each other. For example, for a permanent short circuit 28 between reclosers R 1 and R 2 , after recloser R 1 opens permanently, recloser R 1 could send a signal to recloser R 2 telling recloser R 2 to also open. Then, when recloser R 3 closes, there would be no large short circuit current which would stress the system as described above, and there would be no temporary power degradation for Load 3 , Load 4 , Load 5 and Load 6 . Similar benefits are possible for other short circuit locations when the reclosers communicate with each other. In another example, if the power source inside the substation is de-energized, then the protective relay associated with circuit breaker 24 could send a signal to recloser R 1 not to open. Then, when the power source inside the power station is reenergized, recloser R 1 would still be closed and the downstream loads would be reenergized immediately without manual intervention.
[0072] However, communications infrastructure is rarely available to allow reclosers to communicate with each other in a typical looped distribution line 32 . What is needed is a way to prevent the shortcomings described in A:, B: and C: above, without requiring dedicated or traditional communications between the reclosers.
[0073] Note that while a sectionalizer switch 26 is used in FIG. 2 , reclosers R 1 -R 5 are used in FIGS. 4-13 and circuit breakers 24 - 25 are used at the substation 22 in FIGS. 1-13 , that these devices, including their respective controllers, may be more generally characterized as preprogrammed switches. Of interest with respect to the present invention is that these preprogrammed switches are programmed or set to have at least one open interval in response to a short circuit that is of a known length or duration. Preferably, the preprogrammed switches in the upper segment of the looped distribution line (such as circuit breaker 24 and reclosers R 1 and R 2 in FIGS. 4-13 ), each have a unique open interval of different times such that the other preprogrammed switches in that segment and the normally open recloser R 3 can determine which preprogrammed switch opened in response to the presence of a short circuit on the looped distribution line 32 .
[0074] In accordance with one aspect of the present invention, the methods described herein prevent added stress to the power system and to the power system components when recloser R 3 closes in a looped distribution system 31 similar to that shown in FIG. 4 . To prevent the problematic short circuit current from flowing when recloser R 3 closes, it is necessary to:
[0075] 1: Open recloser R 2 before recloser R 3 closes when a permanent short circuit exists between reclosers R 1 and R 2 .
[0076] 2: Prevent recloser R 3 from closing when a permanent short circuit exists between reclosers R 2 and R 3 . Again, similar discussions and results exist for the other half of the looped distribution line.
[0077] Notice that in both required actions above, both reclosers R 2 and R 3 apparently need to know the location of the short circuit. The present invention allows recloser R 2 and R 3 to operate as required in 1: and 2: above without requiring detailed knowledge of the short circuit location and without the need for communications circuits between the reclosers. The reclosers still operate from a fixed set of processes, but the processes are different than for the system previously described.
[0078] In accordance with another aspect of the present invention, the methods described herein prevent unnecessary extended outages when the power source inside the substation de-energizes. Such an outage is caused when recloser R 1 or R 5 opens during the source de-energization. When recloser R 1 or R 5 opens during such a source de-energization, manual intervention may be necessary to close recloser R 1 or R 5 after the source is reenergized. To prevent such an extended outage, it is required to prevent recloser R 1 or R 5 from opening during source de-energizations.
[0079] FIG. 17 shows the rules of operation for recloser R 3 . The flow charts refer to conditions C 1 _L, C 1 _R, C 2 and C 3 . These names have no significant meanings, and the conditions are defined later. Bold lines in FIG. 17 indicate changes to the prior art, and non-bold lines are the prior art.
[0080] FIG. 18 shows a flow chart that includes the rules of operation for reclosers R 2 and R 4 . Again, the bold lines are changes to the prior art, and non-bold lines are the prior art.
[0081] FIG. 19 shows a flow chart that includes the rules of operation for reclosers R 1 and R 5 . Again, the bold lines are changes to the prior art, and non-bold lines are the prior art.
[0082] Suitable selections for conditions C 1 _L, C 1 _R, C 2 and C 3 are now presented. Conditions C 1 _L, C 1 _R, C 2 and C 3 are checks against the duration of the final open interval (or possibly some other open interval, or some combination of open intervals) of some other recloser or circuit breaker as sensed by the recloser performing the condition checks. An open interval is the time when a recloser or circuit breaker is open between the closings that test the line for a temporary short circuit. One of the aspects of the present invention is to detect which recloser or substation breaker is opening and closing by setting each device with a unique open interval duration for at least one of the open intervals. All other reclosers on the same circuit can then measure the open interval and know which recloser or substation breaker is operating. By knowing which device is operating, the recloser sensing the duration of the open interval can know between which two devices the short circuit exists.
[0083] In the examples which follow, we concentrate on the final open interval before a recloser or substation breaker finally opens and remains open due to a permanent short circuit. Other modifications to the present invention could be to choose some other open interval, such as the first, second, shortest, longest, etc.
[0084] As an example of the selections, assume that the substation breaker has a final open interval of about 30 seconds, recloser R 1 has a final open interval of about 45 seconds, and recloser R 2 has a final open interval of about 60 seconds. Condition C 2 could be chosen as “shorter than about 35 seconds”. In other words, in FIG. 4 when recloser R 2 detects a final open interval shorter than about 35 seconds, it “knows” that the substation breaker was performing the line tests, because the substation breaker has a final open interval of about 30 seconds. Recloser R 2 “knows” that it must not have been recloser R 1 performing the line tests because recloser R 1 has a final open interval of about 45 seconds. Since the substation breaker was performing the line tests, and recloser R 1 was not performing the line tests, the short circuit must lie between recloser R 1 and the substation breaker. In that case, per FIG. 18 , recloser R 2 would configure to protect the line between reclosers R 1 and R 2 in preparation for recloser R 3 closing and recloser R 1 opening.
[0085] If on the other hand, recloser R 2 sensed a last open interval longer than about 35 seconds, then it “knows” recloser R 1 was testing the line because it has a final open interval of about 45 seconds. Recloser R 2 then “knows” that the short circuit lies between reclosers R 1 and R 2 . Per FIG. 18 , recloser R 2 opens to prevent stressing the rest of the system with a large short circuit current when recloser R 3 closes.
[0086] A suitable selection for condition C 1 _R is “shorter than about 50 seconds”. In other words when recloser R 3 in FIG. 4 detects a final open interval shorter than about 50 seconds, it “knows” that recloser R 2 was not testing the line for a temporary short circuit, because recloser R 2 has an open interval of about 60 seconds. Since recloser R 2 was not testing the line, the permanent short circuit does not lie between recloser R 3 and R 2 , and it is safe for recloser R 3 to close. Accordingly, as shown in FIG. 17 , recloser R 3 will configure to protect the “right” line, or the line between reclosers R 3 and R 2 , and will close.
[0087] On the other hand, if recloser R 3 detects an open interval longer than about 50 seconds, it “knows” that recloser R 2 was testing the line, and the permanent short circuit lies between reclosers R 3 and R 2 . Accordingly, as shown in FIG. 17 , recloser R 3 would not reconfigure to protect either right or left line, and more importantly recloser R 3 would not close. This prevents stress to the system, because if recloser R 3 closes, a large short circuit will flow from the substation through reclosers R 4 , R 5 and R 3 to the short circuit between reclosers R 3 and R 2 .
[0088] Note that condition C 1 _L could be the same as or different than condition C 1 _R depending on the open intervals selected for reclosers R 4 and R 5 and the substation breaker attached to recloser R 5 .
[0089] A suitable selection for condition C 3 in FIG. 19 might be “longer than 25 seconds”. In other words, when recloser R 1 detects an open interval longer than 25 seconds, it knows that the substation breaker was testing the line for temporary short circuits because the substation breaker has a final open interval of 30 seconds. If the line is de-energized and there are either no attempts to test the line for short circuits, or the last open interval does not match the required last open interval of the breaker, then the power source within the substation must have been de-energized. Accordingly, recloser R 1 will not open, so that when the power source inside the substation is reenergized, the loads downstream of recloser R 1 will be reenergized immediately without delay or need for manual intervention.
[0090] The above representative time durations are for illustrative purposes only. Actual times could be significantly longer or shorter. The conditions C 1 _R, C 1 _L, C 2 and C 3 used herein are only one possible set of conditions that create the desired result. Other condition sets are possible.
[0091] The operation of recloser R 3 in accordance with the present invention is summarized in FIG. 17 . After starting at bubble 70 , recloser R 3 determines if line 32 is de-energized on only one side of recloser R 3 at decision block 71 . If the line is energized on both sides, or de-energized on both sides, recloser R 3 continues to check the voltage on line 32 until line 32 is de-energized on either side of recloser R 3 , but not on both sides of recloser R 3 . When recloser R 3 detects that the line is de-energized on exactly one side of recloser R 3 , the process proceeds to decision block 72 to determine if line 32 is de-energized to the right of recloser R 3 . If so, recloser R 3 determines if the last open interval satisfied the condition C 1 _R at block 73 . If not, the process ends at end bubble 78 . However, if the condition C 1 _R is satisfied at block 73 , recloser R 3 configures to protect line 32 to the right at block 74 . Recloser R 3 then closes, as indicated at block 75 . It then continues to sense for short circuit current at decision block 76 . If a short circuit current is detected, recloser R 3 opens at block 77 and the process terminates at end bubble 78 .
[0092] Returning to decision block 72 in FIG. 17 , if recloser R 3 determines that the line to the right is not de-energized, recloser R 3 determines if the last open interval satisfied the condition C 1 _L at block 79 . If not, the process ends at end bubble 78 . However, if the condition C 1 _L is satisfied at block 79 , recloser R 3 configures to protect line 32 to the left at block 80 . The process then continues to block 75 where recloser R 3 closes. It then continues to sense for short circuit current at decision block 76 . If a short circuit current is detected, recloser R 3 opens at block 77 and the process terminates at end bubble 78 .
[0093] The operation of reclosers R 2 and R 4 in accordance with the present invention is summarized in FIG. 18 . After starting at bubble 80 , reclosers R 2 and R 4 determine if a short circuit current is present on line 32 at decision block 81 . If a short circuit is present, reclosers R 2 and R 4 determine at decision block 82 if the short circuit current lasts longer than a first predetermined time. If not, the process begins again at start bubble 80 . If the short circuit current lasts longer than a predetermined time, then recloser R 2 or R 4 opens at block 89 . Decision block 90 determines if the line has been tested for temporary short circuits more than a predetermined number of times. If it has, then the process ends at block 88 . If the line has been tested for a temporary short circuit less than a predetermined number of times then the recloser R 2 or R 4 is closed at block 91 and the process continues from the start bubble. If no short circuit current is detected at decision block 81 , then a check is performed to determine if the line is energized for longer than a predetermined time at decision block 83 . If the line is not de-energized for longer than a predetermined time, then the process continues from the start bubble. If the line is de-energized for longer than a predetermined time, then a check is made at decision block 84 to determine if the last open interval satisfies condition C 2 . If the last open interval satisfies condition C 2 , then recloser R 2 or R 4 is reconfigured to protect the upstream line, i.e. recloser R 2 or R 4 is reconfigured to protect the line between R 1 and R 2 or between R 5 and R 4 . Reclosers R 2 and R 4 again monitor line 32 for a short circuit current at decision block 86 . If a short circuit current is detected, recloser R 2 and/or recloser R 4 open at block 87 and the process ends at bubble 88 .
[0094] However, if the condition C 2 was not satisfied at decision block 84 , reclosers R 2 and/or R 4 skip blocks 85 and 86 , proceeding to block 87 where reclosers R 2 and/or R 4 are opened. Thus, in this instance, reclosers R 2 and/or R 4 immediately open and skip the steps of first configuring to protect the upstream line (block 85 ) and to first detect a short circuit current (block 86 ). The process then ends at bubble 88 .
[0095] The operation of reclosers R 1 and R 5 in accordance with the present invention is summarized in FIG. 19 . After starting at bubble 93 , reclosers R 1 and R 5 determine if a short circuit current is present on line 32 at decision block 94 . If a short circuit is present, reclosers R 1 and R 5 determine at decision block 95 if the short current lasts longer than a first predetermined time. If the short circuit current does not last longer than a predetermined time, then the process reverts to start bubble 93 . If the short circuit current lasts longer than a predetermined time, then recloser R 1 or R 5 opens at block 99 . Decision block 100 determines if the line has been tested for temporary short circuits more than a predetermined number of times. If it has, then the process ends at bubble 98 . If the line has been tested for a temporary short circuit less than a predetermined number of times then the recloser R 1 or R 5 is closed at block 101 and the process continues from the start bubble. If short circuit current is not detected at decision block 94 , then recloser R 1 or R 5 determines if the line has been de-energized for longer than a predetermined time at decision block 96 . If the line has not been de-energized for longer than a predetermined time, then the process reverts to start bubble 93 . If the line has been de-energized for a predetermined number of times, then recloser R 1 or R 5 determines if the last open interval satisfies condition C 3 at decision block 102 . If the last open interval does not satisfy condition C 3 , then the process reverts to the start bubble 93 . If the last open interval satisfies condition C 3 at block 102 , then recloser R 1 or R 5 opens at block 97 , and the process ends at bubble 98 .
[0096] It should be noted that while all of the examples shown above included five reclosers and two substation breakers, the invention is also effective at reducing stress to power system components and reducing the number of unnecessary temporary outages if there are fewer than five reclosers in the scheme. As an example, FIG. 20 shows a connection of two substation circuit breakers and three reclosers. In FIG. 20 , recloser R 1 and R 5 operate according to the flow diagram of FIG. 19 , and recloser R 3 operates according to FIG. 17 . The system of three reclosers shown in FIG. 20 is as effective at reducing stress on power system components and reducing the number of unnecessary temporary outages as the system of five reclosers described previously.
[0097] Moreover, many of the drawing figures illustrate a load disposed between each adjacent pair of reclosers. It will be appreciated by those skilled in the art that loads may not always be disposed in the distribution system between each adjacent pair of reclosers. Likewise, certain reclosers have been illustrated in various drawing figures as being located within a substation. Again, it will be appreciated that such reclosers are not limited to a specific location, but may be disposed at other locations in the distribution system.
[0098] It will be further appreciated that, while the looped distribution systems shown in FIGS. 4-13 and 20 , and the flow charts shown in FIGS. 14-16 , have been indicated as prior art, the systems shown in FIGS. 4-13 and 20 and the flow charts in FIGS. 14-16 are not prior art when the circuit breakers and reclosers illustrated therein are programmed to operate in accordance with the teachings of FIGS. 17-19 . Instead, such systems and flow charts then become part of the present invention.
[0099] While particular embodiments of the invention have been shown and described, it will be obvious to those skilled in the art that changes and modifications may be made therein without departing from the invention in its broader aspects.
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A plurality of preprogrammed switches is disposed in a looped distribution line downstream from a source of power to respond to a short circuit and to reconfigure the line to isolate the short circuit. Some of the preprogrammed switches are each provided with a unique open time interval, such as t1, t2 and t3. Others of the plurality of preprogrammed switches can then determine which switch is opening in response to the short circuit and can identify the portion of the line that is shorted. Certain of the preprogrammed switches can then reconfigure to protect the identified portion of the line.
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BACKGROUND OF THE INVENTION
The present invention relates to a locking device, specifically, to a locking device adapted for locking the trunk, side bags, etc., (hereinafter referred to as "accessory compartments") of a two-wheel vehicle such as a motorcycle.
For the purpose of locking the accessory compartments of a two-wheel vehicle it has been the customary practice to employ standard key-type locks. However, key-type locks are especially inconvenient in a motorcycle environment where keys can easily be lost and are difficult to use because the rider often wears gloves. Accordingly, it has long been felt necessary to improve the locking devices used for accessory compartments of motorcycles and the like. In one such approach, electromagnetic solenoid valves have been employed in automatic locking devices, but are not entirely suitable for use on motorcycles due to their relatively large size, high cost and heavy weight.
Therefore, it is a primary object of the present invention to provide a locking device for a two-wheel vehicle which avoids the above-mentioned difficulties.
SUMMARY OF THE INVENTION
These, as well as other objects of the invention are met by a locking device for locking accessory compartments for two-wheel vehicles and the like, comprising a source of pressurized fluid, pressure-operated locking means for locking a cover of a compartment when pressure supplied thereto is below a predetermined level and unlocking the cover of the compartment when the pressure supplied thereto is above the predetermined level, and control means for controlling a flow of pressurized fluid from the source to the locking means. Preferably, the locking means comprises a pressure cylinder having a piston slidably fitted therein, a locking member fixed to the piston, and means for coupling an outlet of the source to a piston chamber of the pressure cylinder. A lock fitting is fixed to the cover, the lock fitting having formed therein a hole for receiving an end of the locking member in a locked position of the locking member, and first and second retainer fittings and fixedly coupled to a main body of the compartment, the retainer fittings having holes located opposite one another for receiving an end of the locking member in the locked position of the locking member, and the retainer fittings defining a slot therebetween for receiving the lock fitting. The control means may comprise a three-way valve including a valve housing having an inlet port and first and second discharge ports, the inlet port being coupled to an outlet of the source, the first discharge port being coupled to the piston chamber, and the second discharge port being vented to the atmosphere, a valve body slidably disposed in the valve housing, the valve body having a first position in which the inlet port is blocked and the first and second discharge ports and connected together, and a second position in which the inlet port is connected to the first discharge port, and the valve body having an operator-actuable head portion for manually moving the valve body between the first and second positions, and a spring biasing the valve body towards the first position. Preferably a key-lockable compartment is provided in which the control means is disposed.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a motorcycle on which a locking device of the present invention is installed;
FIG. 2 is a plan view of the vehicle of FIG. 1;
FIG. 3 is a perspective view showing the manner in which a trunk cover is engaged with a main body;
FIG. 4 is a sectional view of a locking device of the invention;
FIG. 5 is a piping connection diagram; and
FIG. 6 is a perspective view illustrating the manner in which a central switch panel is mounted.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Preferred embodiments of a locking device of the present invention will be described with reference to FIGS. 1 through 6 of the accompanying drawings.
A motorcycle 1 shown in FIGS. 1, 2, and 5 is equipped with plural accessory compartments, including a compartment 3 located forward of a seat 2. In a chamber 3a of the compartment 3 is disposed an air compressor 6 driven by an air pump 4. Compressed air expelled from the air compressor 6 is dehumidified by a drier 5. Suspension components 9 and 10 for the front and wheels, respectively, are adjusted by controlling the flow of pressurized air thereto by a switch located on a central control panel 8, FIG. 2, disposed rightwardly of a front cowl 7.
The accessory compartments of the motorcycle further include a rear trunk 11 and right and left side bags 12 and 13, respectively, carried rearwardly of the seat 2. Locking devices 14, 15, and 16 are provided for these respective accessory compartments. Each of the locking devices 14, 15, and 16 has the same construction. As an example, the locking device 14 for the trunk 11 will be described with reference to FIGS. 3 and 4.
An air cylinder 17 is mounted on a main body 11a (a portion of the compartment which is rigid with the frame of the motorcycle, that is, other than the movable lid or cover of the compartment). In the air cylinder 17 is slidably fitted a piston 19, the latter being integrally formed with a locking member 18. A pressure chamber 17b is defined on the side of the piston 19 where the locking member 18 is located. An air supply port 20 communicates with the chamber 17b. A spring 21, disposed in a rear chamber 17c, urges the locking member leftwardly in the drawing. The forward end of the locking member 18 has an inclined surface 18a normally inserted in holes 22a and 23a in guide segments 22 and 23, respectively, also rigidly secured to the main body 11a.
A cover 11b is provided with a retainer fitting 24 having a locking member receiving hole 24 formed therein. A spring 25 lightly lifts the cover 11b in the unlocked state. The retainer fitting 24 is fitted in a slot 26, FIG. 4, formed between the guide segments 22 and 23 in the locked state.
Reference numerals 12a and 13a identify the main bodies of side bags 12 and 13, respectively, and 12b and 13b, their corresponding covers.
The operation of the locking device 14 arranged as described above will now be explained.
To lock the cover 11b, the cover 11b is pushed so as to force the retainer fitting 24 into the slot 26 so that the forward end of the retainer fitting 24 presses against the inclined surface 18a at the end of the locking member 18, thereby retracting the locking member 18 and moving the piston 19 against the force of the spring 21 (rightwardly in the drawing). When the holes 22a and 23a are in alignment with the hole 24a, the spring 21 forces the locking member 18 towards the hole 22a (leftwardly in the drawing), thereby achieving the locked state.
When the cover is to be unlocked, compressed air is supplied via the supply port 20 to the chamber 17b to thus cause the locking member 18 and the piston 19 to be retracted against the force of the spring 21, thereby moving the locking member out of engagement with the hole 24a in the fitting 24, and thus releasing the locked state. The light force of the spring 25 then lifts the cover 11b.
Next, an example of the piping system used to supply compressed air to the air cylinder 17 will be described.
A first segment of a line 29, FIG. 5, is connected between a control valve 27, which includes an air pressure sensor 28, and a switch on the central control panel 8, while a second segment of the line 29 receives compressed air at the outlet of the drier 5. A first segment of another line 31 is connected between a valve 30, used to control the flow of air to the tires, and a T connector, while a second segment of the line 31 is connected between the T connector and the outlet of the drier 5. The outlet of the T connector is coupled to a line 34 via a check valve 35, associated with an accumulator 36, and thence to the inlet port 37a of a three-way control valve 37. The control valve 37 has two discharge ports 37b and 37c. A valve body 37e is normally urged by a spring 37d into a position in which the inlet port 37a is closed and a line 38, connected to the discharge port 37b, is communicated with the discharge port 37c, which is open to the atmosphere. The line 38 is connected via a distributor to the supply ports 20 of each of the locking devices 11, 12 and 13. Therefore, in this position, the supply ports 20 are communicated with the atmosphere, and hence the locking devices are in their locked states. In the other position of the valve body 37e, air can be supplied via the lines 31 and 34 to the supply ports 20, hence placing the locking devices 11, 12 and 13 in their unlocked states.
Also, lines 32 and 33 are connected between the control switch panel 8 and the suspension components 9 and 10.
As shown in FIGS. 1 and 2, the three-way valve 37 is mounted in a receptacle 3c of the compartment 3 which can be locked with an ordinary key-type lock. The central control panel, as showwn in FIG. 6, carries a switch SW1 for supplying compressed air to the front suspension, a switch SW2 for supplying air to the rear suspension, a control switch SW3 for the air pump 4, and a purge switch SW4 for the control valve. The tire pumping valve 30 and the switch SW3 are mounted below the panel 8. A hose is coupled to the valve 30 for carrying air for the tires.
To unlock the various accessory compartments, first, the cover 3b, FIG. 1 of the compartment 3c is unlocked using a key. At the same time, the switch SW3, FIG. 6, is actuated to turn on the air pump 4, thus supplying pressurized air from the air compressor 6 to the three-way valve 37. Then the valve 37 FIGS. 1, 5, is actuated by manually pressing down upon its head portion, thereby supplying air to the various cylinders 17. Assuming that the pressure of the pressurized air is above a level to overcome the force of the spring 21, the various locking devices are placed in their unlocked state in the manner described above. That is, pressurized air is supplied through the line 38 to the various cylinders 17, causing the pistons 19 to be retracted against the force of the springs 21, and thus retracting the locking members 18. To again lock the locking devices, the valve 37 is merely released, whereupon the flow of pressurized air to the cylinders 17 is halted. The locking members and associated pistons are then pushed towards the locked position by the action of the springs 21. The pressurized air from the cylinders 17 is vented through the discharge port 37c of the valve 37.
Although the above-described embodiment has been discussed with reference to the case where an air compressor is employed as the pressure generating source, it is believed apparent that a hydraulic pump can be used as well. Moreover, the present invention is equally applicable to burglar-proofing devices such as steering locking devices and the like. Further, the invention can be applied to vehicles other than two-wheel vehicles.
This completes the description of the preferred embodiments. Although preferred embodiments have been described, it is believed that numerous modifications and alterations thereto would be apparent to one of ordinary skill in the art without departing from the spirit and scope of the invention.
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A locking device especially useful in locking accessory compartments of motorcycles and the like. Each accessory compartment is provided with a lock mechanism including a pressure-actuated cylinder, a locking member fixed to a piston of the cylinder, and locking fittings through which the locking member projects in the locked position. Pressurized air is supplied to the cylinders to unlock the compartments from a three-way control valve located in a key-lockable compartment.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of prior filed, copending U.S. provisional patent application Ser. No. 60/200,694, filed 29 Apr. 2000.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to a pollution control apparatus, and, more specifically, to an apparatus for attachment to a storm water inlet, such as a curbside inlet, for collecting storm water pollution, such as sediment, floating debris and floating residues, from storm water runoff.
[0004] 2. Background
[0005] It has been reported that forty percent of our nation's rivers, lakes and streams are considered unfit for fishing, swimming, drinking or aquatic life. Urban streams have substantially more problems because high sediment loads affect many aspects of water quality, including water temperature, pH, total suspended solids, total dissolved solids, nutrients, metals, pesticides, and bacteria. Sediment loads from lands undergoing urbanization are up to 50 times more than those in rural areas. It is excessive sediment, generated as anthropogenic waste, that often overwhelms the “assimilative capacity” of a stream and damages its biological components.
[0006] A primary cause of diminished water quality is urban storm water runoff. Urban runoff is a pollutant that consists of soil sediment, floating organic matter, floating man-made debris, chemicals, and other residues. The quality of urban runoff is thus an important issue due to the negative effects it can have on ecological systems and water body volume. Urban runoff carries large amounts of soil sediment which increases the turbidity of water, causes siltation of reservoirs, lakes and ponds, and ultimately adversely impacts aquatic plants, invertebrates and fish.
[0007] One of the greatest contributors to sediment entering storm water systems comes from construction sites, where soil is exposed and can easily erode and be transported into the drainage system. The major problem at construction sites is the period of time that disturbed surfaces lay exposed, more than a year at 25% of the sites. Most cities have the authority to regulate construction sites to make sure they are complying with regulations to reduce the amount of sediment coming from the sites. Covering exposed soil, setting up filter fences and straw bales, reseeding exposed soil and using gravel at exits and entrances are all practices used to reduce soil erosion from construction sites.
[0008] Soil can also be distributed throughout a city on rooftops and on streets by wind. Having a combination of high winds and large amounts of agricultural land in more rural areas sets up the conditions for large amounts of soil to be deposited on streets throughout a city. The soil is then washed into the storm water system in a rain event.
[0009] Soil can also come from the thousands of vehicles that travel the streets. Vehicles collect soil from back roads and alleys, then transport it to the city streets, where the soil can easily be washed into the storm water systems. Soil contributors come from many different places, and the same is true with contributors of municipal trash and debris that enters the storm water systems.
[0010] Municipal trash is especially difficult to eliminate because of the wide variety of contributing sources. Municipal trash has several opportunities to slip through the sanitation removal system. For example, animals, weather, and people all add to the enormous amount of trash that is available to be carried into a storm water system. In addition to sediment and municipal trash, natural debris like tree limbs, grass clippings, and leaves, contribute to the problems in storm water systems.
[0011] There are many other sources and types of pollutants that enter urban runoff. Petroleum products, fertilizers, chemicals, pesticides, and fecal bacteria are all pollutants found in urban runoff. The key contributor to all of these pollutants is man and his mishandling and misuse of products.
[0012] Many cities are actively seeking procedures and devices that can improve the quality of storm water runoff. The problem is currently being addressed in two principal ways. First, most cities regulate construction sites. Regulation ensures that construction sites have the proper erosion control devices installed to limit the amount of soil coming from a construction site, both from water flow and from traffic flow. Second, significant funds are expended on cleaning city streets with sweepers and manually cleaning out storm water inlets. Due, however, to budget and manpower constraints only a minimal level of maintenance is generally performed, enough only to keep storm water systems functioning.
[0013] The current control methods fall drastically short of meeting pollution control goals. Present methods do not stop any sediment or debris present in runoff streams from entering and passing through the storm water system nor do they serve to remove or filter any floatable contaminants. In addition, current systems do not allow for an easy and efficient clean out method.
[0014] The optimum improvement to the quality of storm water runoff would consist of eliminating the aforementioned pollutants while maintaining high flow rates to eliminate flooding potential, recognizing that there will be an expected variation in the degree to which any or all of the pollutants can be removed and to what degree the flowability in the system can be maintained.
[0015] It is thus an object of the present invention to provide a device that will effectively remove a large portion of the pollutants entering a storm water runoff system while maintaining a high level of flowability in the system.
[0016] It is a further object of the invention that the device be simple to construct, install and maintain as well as effective in trapping pollutants entering storm water sewer systems.
SUMMARY OF THE INVENTION
[0017] These and other objects are achieved by capturing pollutants at a particular point of entrance into a storm water runoff system, such as, for example, at curb inlets. The inventive device takes advantage of existing storage volume within storm water inlets and is installed therein with little or no retrofitting necessary to secure the device. Storm water enters the apparatus where water energy is reduced and flow length is increased, increasing water detention time and allowing for the removal of soil sediment, floating debris, hydrocarbons and other pollutants utilizing settling tendencies and trapping areas. A damping system reduces pollutant resuspension and redirects high flows away from deposited sediment.
[0018] Thus, in accordance with the objects of the invention there is provided a method for water detention within a storm water sewer system to allow for the trapping and collection of soil sediment, floating debris, hydrocarbons and other pollutants wherein a waste water stream is routed to a housing suspended below a storm water inlet wherein, depending upon the amount of flow, the stream follows one of two possible flow paths. In low flow conditions the stream is directed such that its flow length and retention time within the housing is increased, thus allowing for the settling out of sediment and for the capture of floating debris and residues. In high flow conditions the stream is diverted to an alternate shorter flow path out of the housing so as not to cause a resuspension of collected sediment.
[0019] A preferred trapping device for use in accomplishing the aforedescribed method includes a two piece housing consisting of front and back portions slidably received together to form a generally rectangular structure to accommodate a common configuration of a storm drain. The device may be shaped so as to conform to other common storm drain configurations or may be specially adapted to fit particular applications. Accordingly, the particular shape of the housing can be varied as needed to complement, for example, round or square drains. For illustrative purposes, the following description will refer as an example to a device for use under a generally rectangular curb inlet.
[0020] A top, hopper-type portion of the device is provided with a lip, being appropriately sized and adapted to be engaged between the lip of the curb inlet grate and the ledge upon which the grate typically rests. The length of the device is such that it is suspended beneath the grate within the curb inlet so as not to impede water flow beneath the structure.
[0021] Water flowing through the grate is directed by an upper surface of the housing into a first detention area within the housing whereupon, under low flow conditions, the water proceeds through a damper into a second larger detention area defined by the walls of the housing. The sediment laden water has a relatively long residency time in the second detention area, thus allowing sediments to settle out from the water. The damper serves to increase the flow length of the sediment laden water stream and minimizes resuspension of sediments contained in the second detention area. Flow between the first and second detention areas is controlled through the adjustment of the damper. In the preferred embodiment, the damper comprises overlapping plates and the degree of separation between the plates controls the flow rate between the first and second detention areas. As the water level rises in the second detention area it climbs upward along the walls of the housing where it eventually advances through a fluid passageway located between the first detention area and the walls of the housing. The water exits the housing through apertures located in the housing walls. The exit points are vertically spaced at a point below the water head in the first detention area so that floating debris and residues are trapped in the first detention area above the exit points.
[0022] During high flow conditions, when the rate of water flow into the first detention area surpasses the maximum rate of flow through the damper, water overflows the first detention area to be released through the exit points in the walls of the housing. In this manner, resuspension of the sediments captured in the second detention area is avoided.
[0023] The inventive device is maintained by periodic removal of the trapped pollutants. Access is afforded to the interior of the device through the removal of the curb inlet grate, whereupon the pollutants are removed by vacuum suction or other means.
[0024] The inventive device is simple and has no moving parts that will wear out, break or reduce efficiency over time. It can easily be adapted into any existing curb inlet or other storm water inlet and optimizes storage volume while maintaining a flow path long enough for adequate efficiency. Pollutant removal is easily accomplished, and the device is very cost effective and manageable.
[0025] A better understanding of the present invention, its several aspects, and its objects and advantages will become apparent to those skilled in the art from the following detailed description, taken in conjunction with the attached drawings, wherein there is shown and described the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated for carrying out the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] [0026]FIG. 1 is a perspective view of a general embodiment of the present invention.
[0027] [0027]FIG. 2 is an exploded view of the components of the device of FIG. 1.
[0028] FIGS. 3 A-G are partial cross sectional views of an upper portion of a general embodiment of the present invention.
[0029] [0029]FIG. 4 is a perspective view of the inventive device shown installed in its typical environment.
[0030] [0030]FIG. 5 is a perspective view of the preferred embodiment of the inventive device.
[0031] [0031]FIG. 6 is a perspective view of the front piece of the device of FIG. 5.
[0032] [0032]FIG. 7 is a perspective view of the back piece of the device of FIG. 5.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0033] The main objective of the preferred embodiment of the invention is to remove soil sediment, floating debris, and a limited amount of floating residues from storm water runoff. The floating residues that the device addresses are primarily floating hydrocarbons deposited on streets and parking lots from vehicular oil leaks. The floating debris is generally a combination of man-made trash and organic material such as leaves, grass clippings, and tree limbs. The trapping of soil sediment focuses on the larger sizes of silt and sand. Before explaining the preferred embodiment in detail, however, it is important to understand that the invention is not limited in its application to the details of the construction illustrated and the steps described herein. The invention is capable of other embodiments and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.
[0034] Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, and particularly referring to FIGS. 1 - 3 , the inventive device 10 , shown generally in a fully assembled condition, has a front 12 and a back 14 . The device 10 comprises a housing 16 consisting of two side panels 18 , 20 , a back panel 22 , and a front panel 24 to form a generally rectangular structure. The device 10 may be of a unitary structure or comprise a multi-piece design, such as the particularly preferred two-piece embodiment described in detail below. The purpose of FIGS. 1 - 3 is to provide a general description of the salient features of the invention.
[0035] One or more of the panels are provided with apertures 25 which serve as water exit points. The size of the apertures 25 are calculated to release the maximum flow rate known for the inlet to which it is attached. At the top portion of the device 10 there is an upper surface comprising a hopper 26 formed of a plurality of angled surfaces 28 . The hopper 26 is provided with a lip 46 , being appropriately sized and adapted to be engaged between the lip of a curb inlet grate and the ledge upon which the grate typically rests. The length of the device 10 is such that it is suspended beneath the grate within the storm water drain so as not to impede water flow from the bottom of the drain into the storm water system piping.
[0036] In addition to supporting the device 10 in a suspended position under the inlet grate, the hopper 26 and angled surfaces 28 function to lengthen the flow path of the device 10 and to direct water flowing through the grate into a first detention area 34 . A set of vertical fins 30 affixed at the terminus of the angled surfaces 28 extends the flow path vertically to within the first detention area 34 while maintaining adequate dimensions between the side panels 18 , 20 and front panel 24 , the purpose of which will become evident from the ensuing description. The vertical fins 30 extend downward in the device 10 to a point below the apertures 25 in the side and front panels 18 , 20 , 24 .
[0037] The first detention area 34 is created within the bounds of diverter 32 , a pair of blockers 36 and damper 38 . The diverter 32 , shown formed from three segments, separates the first detention area 34 from the side and front panels of the housing. The diverter 32 extends above the level of apertures 25 in order than the water head in the first detention area 34 be maintained above the level of the apertures 25 . This allows floating debris and residues to remain above the exit point of the device and within the first detention area 34 under low flow conditions. The blockers 36 are fixed between the vertical fins 30 and the side panels 18 , 20 to prevent the flow of water around the diverter 32 and through the apertures 25 and to provide added structural integrity. The diverter 32 may be tacked to side panels 18 , 20 and front panel 24 for support. The damper 38 , shown as overlapping plates 40 , 42 serves to separate the first detention area 34 from a larger second detention area 44 . The height of the diverter 32 may be varied relative to the aperatures 25 to alter flow characteristics.
[0038] Water flowing through the inlet is directed by angled surfaces 28 at the top of the housing 16 into the first detention area 34 whereupon, under low flow conditions, the water proceeds through the damper 38 into the second larger detention area 44 . The sediment laden water has a relatively long residency time in the second detention area 44 . The allowable flow through the damper 38 may be adjusted, but in the preferred embodiment the distance between the plates 40 , 42 comprising the damper is about 2.5 to 3 inches which, considering the other dimensions of the structure, allows for a flow rate of approximately one cubic foot per second (cfs). As the water level rises in the second detention area 44 it climbs upward through a fluid passageway 45 provided between the diverter 32 and side and front panels 18 , 20 , 24 . The outflow pattern from the second detention area 44 is shown with a dotted arrow in FIG. 3F. The rising water from the second detention area 44 leaves the device through apertures 25 .
[0039] During high flow conditions, when the rate of water flow into the first detention area 34 surpasses the maximum rate of flow through the damper 38 , water overflows the first detention area 34 over diverter 32 to be released through the apertures 25 in the side and front panels of the housing 16 . The outflow path under high flow conditions is illustrated in FIG. 3F with a solid arrow. Having this alternate flow path for high flow conditions reduces resuspension of the sediment that has settled out of the water within second detention area 44 by limiting the amount of flow that passes through the second detention area during periods of high volume runoff.
[0040] The inventive device is maintained by periodic removal of trapped pollutants. Access is afforded to the interior of the device 10 through the removal of the inlet grate, whereupon the pollutants may be removed by vacuum suction, scooping or other means. It is contemplated that a trap door may be designed into the damper 38 , such as a door having a handle and a magnetic latching system, to provide easier access into the second detention area 44 . The bottom of the housing 16 might also be rounded for ease of maintenance. It is further contemplated that weep holes might be located along the side of the device 10 (covered by a shield) allowing for standing water to escape the device without releasing sediment.
[0041] FIGS. 5 - 7 illustrate a particularly preferred two piece device. The two piece device consists of a front piece 100 and a back piece 102 . The back piece is provided with a tube 104 along each of its vertical mating edges into which the rod 106 of the front piece 100 may be slidably received. FIG. 6 best illustrates the structure of the front piece 100 wherein, as it has been previously described, there is provided hopper 126 , vertical fins 130 , lip 146 , apertures 125 , diverter 132 , blockers 136 and damper 138 .
[0042] As shown best in FIG. 7, back piece 102 possesses two plates 140 , 142 which, along with plate 141 in the front piece 100 , comprise the damper 138 . It will be noted that plate 140 in the back piece 102 mates with plate 141 in the front piece 100 . The degree of separation between plate 140 and plate 142 controls the flow rate from the first detention area 134 to the second detention area 144 .
[0043] Typical installation of the device will be described in relation to FIG. 4. The device is dimensioned so that its lip may be engaged between the storm water inlet grate 48 and the ledge 50 upon which the grate 48 rests. The length of the device is such that it is suspended beneath the grate 48 within the storm water drain 52 so as not to impede water flow from the bottom of the drain 52 into the storm water piping system 54 . With reference to the preferred embodiment described above, it would be typical to remove the grate 48 in order to first insert the back piece 102 of the device through the opening into the drain 52 , whereupon the lip of the back piece is positioned upon a ledge on the curb side of the drain 52 . It is common that the curb side of the drain is inset somewhat so that what will be seen from above after insertion of the back piece are basically the mounting tubes 104 . The front piece 100 is then similar inserted through the opening so that its mounting rods 106 are slidably received in tubes 104 and the lip of the front piece is positioned upon a ledge on the street side of the drain 52 . The grate 48 is then replaced, and the device is thus suspended for operation. Other suspension means such as hooks, hangers and other fasteners also may be utilized if so desired.
[0044] It should be further recognized that the aforedescribed description and drawings refer to a device for installation on the left side of a curb inlet. Center and right side devices are, of course, within the scope of the invention.
[0045] The type of material used in the construction of the device may be varied according to strength, durability and thickness requirements and the overall acceptable cost of manufacture. A prototype device was constructed of plexiglass but it is anticipated that a low cost nylon molded product could be used for commercialization, with other suitable materials including fiberglass, metals or heavy duty plastics such as polyethlene.
[0046] The details of the construction illustrated and described above in connection with the preferred embodiment of the invention may be modified by one skilled in the art to achieve particular desired operating parameters and pollutant removal efficiencies. The pollutants that are being addressed can only be effectively captured within a given range of parameters. The design parameters include: concentration of pollutant, flow rate of runoff, and limited flow restrictions. Pollutants have different environmental impacts depending on their concentration and potency. For example, 100 grams of soil sediment will not have the same environmental impact as 100 grams of motor oil. Because of the different environmental impacts, water quality standards are set in place by organizations such as the Environmental Protection Agency (EPA) to monitor storm water runoff quality. The storm water is monitored for pollutants that exceed set concentrations. One quart of motor oil has the potential to contaminate 250,000 gallons of water based on the water quality set by the EPA (City of Laguna, 2000). Accordingly, small amounts of motor oil or other hydrocarbons have the potential to cause large environmental problems.
[0047] For example, the components of the device may be arranged and dimensioned to vary the efficiency of removing soil sediment from storm water. Removing soil sediment is a process that is governed by Stoke's law. Stoke's law is an equation used to determine the settling velocity of particles based off of the particle size:
Vs ={fraction (1/18)}[( d 2 /v )*( SG− 1)],
[0048] wherein
[0049] Vs=settling velocity;
[0050] d=particle diameter;
[0051] g=gravitational constant;
[0052] v=kinematic viscosity; and
[0053] SG=specific gravity of the particles.
[0054] Using a SG of 2.65 and assuming quiescent water at 68° F., the Stoke's law equation reduces to: Vs=2.81d 2 . Using the following USDA table for particle sizes <2 mm in diameter, the resulting settling velocity for various classes of sediment can be calculated.
CLASS SIZE (diameter) Very coarse sand 2.0-1.0 mm Coarse sand 1.0-0.5 mm Medium sand 0.5-0.25 mm Fine sand 0.25-0.10 mm Very fine sand 0.10-0.05 mm Silt 0.05-0.002 mm Clay <0.002 mm
[0055] Knowing the calculated settling velocities enables further calculations to be made to determine what theoretical particle size can be removed for a given flow length and flow rate. The maximum flow rates for typical curb inlets are given below.
max flow flow rate flow rate # of curb inlets rate(cfs) curb(cfs) grate(cfs) 1 4.1 2.5 1.6 2 8.2 5 3.2
[0056] The max flow rate for a single inlet is equal to 4.1 cubic feet per second (cfs). Using the maximum flow rate in units of cubit feet per second and dividing the flow rate by the flow area, given in feet squared, the flow velocity can be calculated having units of feet per second. After obtaining the flow velocity, a flow length can be established that will allow the time needed, based off the settling velocity, for a certain particle size to settle out of the flow path.
[0057] To determine the actual particle size that will settle out of the flow, one skilled in the art will know to determine how far from the main flow path the particle will have to be before it will settle out of the flow stream. The size of the device, constrained by the curb inlet opening, also must be taken into account which limits the use of optimal longer flow lengths. A flow capacity that will allow efficient sediment removal without adversely affecting resuspension must also be determined.
[0058] Calculations can be made to size various parts to achieve the required flow rates. The required flow rates are based on the amount of maximum flow the device must pass and the amount of flow the device will direct through a longer flow path. The flow calculations may be made, for example, using the following weir and orifice flow equations:
[0059] Weir Flow
Q=CLH ({fraction (3/2)}) ,
[0060] wherein
[0061] Q=flow rate in cubic feet per second;
[0062] L=weir length in feet; and
[0063] H=head in feet.
[0064] The weir flow calculations are used to determine the length and height that is needed to pass the max flow and the redirected flow.
[0065] Orifice Flow
Q=C′A (2 gH ) (½) ,
[0066] wherein
[0067] Q=flow rate in cubic feet per second;
[0068] A=cross-sectional area of the orifice in square feet;
[0069] g=gravitational constant;
[0070] H=the head on the orifice; and
[0071] C′=the orifices coefficient.
[0072] The orifice equation is used to calculate the height, given a length, which will pass the redirected lower flow.
[0073] With reference to the trapping of floating pollutants and floating debris, the construction of the components of the device may be arranged and dimensioned to vary the size and placement of storage areas to allow for the inflow of floating pollutants and debris but to otherwise separate the storage areas from the direct flow path of the water to avoid the submergence of the pollutants into the water stream.
[0074] The present invention will be further understood with reference to the following non-limiting experimental example.
EXAMPLE
[0075] A full-scale prototype was designed to simulate hydraulic characteristics, pollutant removal efficiency, and maximum flow capacity. The prototype testing was divided into two specific setups. First, a setup was used that allowed soil to be introduced into the device at a known concentration at relatively low flows ranging from 0.2 to 0.6 cubic feet per second. A second setup was used to introduce high flow rates ranging from 3 to 4.1 cubic feet per second. The second setup did not introduce additional soil; it was used primarily to insure that the maximum design capacity would pass through the device.
[0076] Before the prototype testing proceeded, many testing considerations were addressed. The considerations included the concentration of the soil and water mix, the flow rates, the duration of a testing event, the water entrance conditions, and the types of soil that would be introduced to the mix. A concentration of 3000 mg/l was determined for the soil and water mixture. The concentration of 3000 mg/l was determined based earlier studies in which samples of sediment-laden water were collected and 3000 mg/l was the maximum concentration encountered.
[0077] To address flow rates, an assumption of a critical flow rate was made. The critical flow rate is the flow that allows adequate sediment removal without resuspending the settled particles. A critical flow rate of 1 cfs was used. This flow rate governed the equations used to calculate the dimensions of the prototype. The dimensions, calculated using 1 cfs as the critical flow, are the dimensions of orifices and weir heights that restrict the flow through the sediment detention area to under 1 cfs. Test flows of 0.2, 0.4, and 0.6 cfs were used in the sediment laden water test. These flows were used because they represent the target range for most efficient sediment capturing, and the sediment laden water test was restricted by a maximum of 0.7 cfs. The flow of the maximum capacity test was simply placed at the maximum design flow of 4.1 cfs to insure the device could pass the maximum flow.
[0078] The duration of a testing event was calculated based upon of three pieces of data. First, the maximum flow encountered by a single curb inlet is 4.1 cubic feet per second (cfs). Second, the assumption was made that the maximum flow was encountered during a one hour, one hundred-year flood event. Third, the amount of runoff needed for wash-off is 0.2 inches. The one hour, one hundred-year flood event produces an intensity of 4.1 inches per hour (Haan, Barfield, Hayes, 1994). To produce a flow of 4.1 cfs, an intensity of 4.1 inches per hour must be distributed over 0.99 acres. Using the calculated area, the 0.2 inch wash-off amount, and a predetermined test flow rate, the duration of a test event can be calculated. The duration calculated is the duration needed to produce the volume of water that would be produced from 0.2 inches of rainfall over the calculated area with the given concentration of 3000 mg/l.
[0079] The sediment-laden water was introduced to the device using a mockup of a curb inlet. The mockup was used to insure that entrance conditions were similar to real world conditions. The water was introduced into a cavity that would distribute a gradient of sheet flow with the deepest area being next to the curb and the shallow area extending away from the curb.
[0080] There were two types of soil tested, with one of the soils being introduced with two different characteristics. The first soil type tested was a red clay soil. The soil was prepared from a stockpile of soil. It was sieved using a # 8 sieve. The process of sieving eliminated large aggregate, which aided distributing the proper rate of soil into the water flow. The red clay soil was introduced at a moisture content of 1% and at a moisture content of 10.7%. The difference in moisture content introduced a variance in the amount of aggregate the soils possessed. The amount of aggregate effected the dispersion of the soil in the water. An increase in dispersion reduces the capturing efficiency of the device because the effective particle size is reduced. The second soil tested was a sandy soil. The sandy soil was introduced to compare two very contrasting soil types.
[0081] The testing procedure for the sediment-laden water was a 6-step process. The first step was to determine the soil moisture content (MC) of the soil sample. The soil moisture data is important in determining the mass of soil that needs to be introduced into the water. In order to an equivalent weight of dry soil, it takes more soil at a higher moisture content than soil at a lower moisture content. The concentration of 3000 mg/l is equivalent to 3000 mg of dry soil (0% MC) in one liter of water. Knowing the soil moisture content allows the mass of soil to be adjusted to allow for the proper concentration. The second step was to calculate the flow time and amount of soil to introduce for each flow rate. For each flow rate (0.2, 0.4, and 0.6 cfs), the total volume of water used and the total mass of soil used remains constant. The variables in the test were the duration and rate of soil introduction. The third step was to place the device onto the scales that measure the change in weight of the device. The scales and device were then placed in position under the curb mockup and the device was filled with water and weighed. The fourth step was to calibrate the flow of water using a combination of a known size orifice plate and its corresponding manometer differential. For a given size orifice plate, a valve can be adjusted that changes the manometer differential. Once a target differential was reached that corresponds to the test flow rate, the test was ready to begin. The fifth step was to introduce soil at the given rate for the calculated duration. The soil was introduced into the water flow 30 ft. before the device. The 30-foot distance allowed the soil to become adequately mixed before it entered the device. The soil was metered into the device by introducing a known mass of soil into the stream every minute for the duration of the test. The final step was to stop the flow and let the water drain to the same level as measured previously. When the water was at the previously measured level, the weight of the device was measured.
[0082] Using the sediment-laden setup, other properties of the device were examined. The removal of floating pollutants was another performance characteristic the device was designed to address. To simulate motor oil as an environmental pollutant, mineral oil was placed into the water flow. The device is designed to keep the floating residue out of the direct flow path. The mineral oil was placed into the flow stream then the flow rate was increased from 0 cfs until the turbulence became to high to capture the oil. When the turbulence became too high the oil was submerged into the flow path and exited the device. The threshold for capturing oil was found to be 0.5 cfs.
[0083] Floating debris (domestic trash and grass clippings) was also introduced into the device to allow visual inspection of the flow characteristics of the floating debris. Much of the floating debris was successfully captured in the device. The flow path allows for larger debris (3″), to pass into the storage area, but the outlet from the storage area is reduced to 1 inch.
[0084] The testing procedure for the maximum flow capacity was set up to test two characteristics. The first, and primary, goal was to insure the device could pass the maximum design flow of 4.1 cfs. The second goal was to see how maximum flow conditions affect previously settled particles. The testing was set up in a channel that allowed the introduction of high flows. Once the device was lowered into the channel, sand particles were placed in the bottom of the device to see whether the sand particles would become resuspended. After the device was filled with sand, a flow of 4.1 cfs was introduced to the device. The flow was maintained for 10 minutes. The final procedure was to drain the device and visually insure that no sediment was lost during high flows.
Experimental Results
[0085] Five (5) different sediment-laden test were run under various conditions. The following table is a summary of the data collected from the sediment-laden tests. After each test, a change in weight was found by subtracting the final weight from the initial weight. The change in weight is proportionally related to the mass of soil collected. There is a difference because the soil particles that displace the water and water have different densities. The conversion from the change in weight to the actual mass of soil collected can be calculated from the following equation:
Weight of soil trapped=Δ W * (SGsoil/(SGsoil−SGwater)),
[0086] wherein
[0087] SG=specific gravity;
[0088] SGoil=2.65; and
[0089] SGwater=1.
[0090] Particle densities for most mineral soils vary between the narrow limits of 2.60 to 2.75 g/cm 3 . A particle density of 2.65 may be assumed if the actual particle density is not known (Brady & Weil, 1999). Clay and sand samples were measured by mass and placed in a known volume of water to calculate the particle density. Particle density was calculated on the sand and clay soil samples, and the densities ranged from 2.54 to 2.66 g/cm 3 . Since there was such a narrow range in densities, the assumption of 2.65 g/cm 3 was used as the particle density for both soil types.
SOIL FLOW DURATION MASS OF SOIL TEST # TYPE RATE (cfs) (min) INTRODUCED MC soil 1 WET CLAY 0.6 15.40 107.5 10.73% 2 WET CLAY 0.4 33.25 149.0 10.73% 3 WET CLAY 0.2 50.00 111.5 10.73% 4 DRY CLAY 0.4 15.00 68.4 1.00% 5 SAND 0.4 16.60 62.7 2.32% CONCENTRA- MASS OF TION DELTA WEIGHT MASS OF SOIL TEST # DRY SOIL (mg/l) OF DEVICE TRAPPED % EFFICIENCY 1 95.97 2772.9 50 80.30 83.00% 2 133.01 2669.9 66 106.30 79.00% 3 99.5 2656.4 45 72.50 73.00% 4 67.72 3013.3 9 14.50 21.00% 5 61.25 2462.7 32 51.52 84.00%
[0091] The particle size distribution of the soil entering the device compared to the particle size distribution that remains in the device can be a very instrumental comparison. Knowing the capability of the device on a particle size basis enables the efficiency of the device to be projected to a multitude of soil types.
[0092] One procedure for conducting such a particle size analysis involves passing a measured amount of a soil sample (such as 65 grams of silt or clay soil or 115 grams of sandy soil) through a #4 and #10 sieve, whereupon the mass of the soil retained is measured and recorded. The soil that passes through the #10 sieve is soaked in a solution of sodium hexametaphosphate solution for 16 hours to aid in the dispersion of soil aggregate. The solution is then added to a glass sedimentation cylinder and demineralized water is added until the total volume is equal to 1000 ml. The 1000-ml solution is stirred to ensure the particles are adequately dispersed and the hydrometer is immediately placed into the solution. Hydrometer readings are taken at 15, 30, 60, and 120 seconds and at 5, 15, 30, 60, 240, and 1440 minutes. The hydrometer and sieving procedures produce values that are usable to calculate particle sizes in mm and the percentage of finer particle sizes contained in the sample.
Device Maintenance
[0093] The maintenance on any single device can vary greatly depending on a number of variables, including sediment concentration and rain events and intensities. For example, Oklahoma City encompasses an area of 650 square miles. Within this area, there are approximately 200,000 curb inlets. Over this large area, a rain event may only affect certain portions of the area. Of the area effected by a rain event, there could be a variety of activities that could alter the concentration of soil particles flowing in the water. Construction sites, gardening, muddy roads, and the amount of impervious versus pervious ground can drastically change flow conditions and concentrations. The maintenance schedule will simply be an approximation using the following parameters: weather data collected from the Oklahoma City area, an average concentration of 3000 mg/l of soil particles in the run off water, and the requirement of 0.2 inches of runoff to wash off a developed area (thus runoff exceeding the 0.2 inches of rainfall is considered relatively free of sediment). The final parameters are the drainage area and the storage volume of the device. Using these parameters an expected filling time of the device can be calculated. The filling time also takes into consideration that organic matter will consume a portion of the volume.
[0094] To illustrate, soil samples were collected from existing curb inlets. These soil samples were analyzed for both particle size analysis and percent organic matter. Four samples were collected from the Oklahoma City area. The four samples were placed in an oven for 4 hours at 105° F. to remove moisture from the samples. After the soil was dry, it was weighed. The dry soil sample was placed in the muffle furnace at 550° C. for 24 hours. The muffle furnace was used to burn off the organic matter. The soil sample was weighed again, and the differential in weight corresponded to the loss of organic matter. The four samples had an average of 11.75% organic matter. Soil particles have a particle density of 2.65 g/cm 3 and organic matter has a particle density of 1.1 g/cm 3 (Brady & Weil, 1999). Using these two densities, a weighted average of particle densities was calculated:
[(88.25*2.65 g/cm 3 )+(11.75*1.1 g/cm 3 )]/100=2.47 g/cm 3
[0095] The soil and organic matter that will fill the device will accordingly possess an average particle density of 2.47 g/cm 3 . The 3000 mg/l is the concentration of suspended particles in solution, so the average density of the suspended particles is estimated at 2.47 g/cm 3 .
[0096] The preferred inventive device has a volume of 8 cubic feet. The amount of time needed fill the 8 cubic feet storage volume is dependent on the number of rain events that exceed 0.2 inches of runoff per year, as well as the area that each inlet services, the concentration of the suspended particles in the run-off, and the trapping efficiency of the device. The number of rain events that exceed 0.2 inches of runoff is dependent on the curve number that best represents an urban area. Using a conservative curve number of 95 allows for the amount of rain needed to produce 0.2 inches of run-off (the wash off amount). Turn now to the formula:
Q= ( P− 0.2 S ) 2 /( P +0.8 S ),
[0097] wherein
[0098] S=(1000/CN)−10;
[0099] P=accumulated precipitation (inches);
[0100] S=parameter;
[0101] Q=runoff (inches); and
[0102] CN=curve number (95 for a conservative # for urban areas).
[0103] Runoff begins after 0.2S of rainfall has fallen. Using the equation, it takes 0.52 inches of rainfall to initiate runoff. Using the value of 0.52 inches, we examine previous weather data to see how many 0.52 inch rainfall events occur each year. Every 0.52 inch rainfall event will not produce the concentration of 3000 mg/l because it takes a significant amount of time between events to accumulate the particles to produce that concentration.
[0104] As further example, the Oklahoma City area incurred approximately 40 rain events over 0.5 inches between 1997 and 1999. Although many of the events were not spaced far enough apart to allow adequate time for a build up of sediment, all 40 events were used in the approximation to ensure a conservative estimate on device fill up time.
[0105] The service area of a single curb inlet was previously calculated from the maximum of 4.1 cfs delivered during a 100 year flood event. The service area is thus calculated to be 43200 feet squared. Refer now to the following data and formulae:
[0106] SERVICE AREA=43200 ft 2
[0107] SOIL DENSITY=2.47 g/cm 3
[0108] STORAGE VOLUME=8 ft 3
[0109] RAIN EVENTS/YEAR=13.3 events/year
[0110] CONCENTRATION=3000 mg/l
[0111] WASH OFF AMOUNT=0.2 inches
[0112] EFFICIENCY=65%
cm 3 /year=[(0.2 in )(1 ft/ 12 in )(43200 ft 2 )(1 liter/0.0353 ft 3 )(3 g /liter)(13.3 events/year)]/[(2.47 g/cm 3 )]
SEDIMENT ENTERING THE DEVICE(cm 3 /year)=3.29 E 5 =11.64 ft 3 /year
SEDIMENT RETAINED IN DEVICE=(11.64 ft 3 /year)(0.65 efficiency)=7.6 ft 3 /year
[0113] Using conservative values for both the curve number and the number of wash off events produces a volume of sediment per year that is more than what should be expected. The volume of sediment trapped per year was approximately 7.6 ft 3 /year, and the device has a holding capacity of 8 ft 3 . Dividing the holding capacity by the expected sediment volume per year produces a fill up time of approximately one year.
[0114] While the invention has been described with a certain degree of particularity, it is manifest that many changes may be made in the details of the process of assembly without departing from the spirit and scope of this disclosure. It is understood that the invention is not limited to the experimental methods set forth herein for purposes of exemplification.
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Pollutants are captured at a particular point of entrance into a storm water runoff system, such as at curb inlets. An inventive device takes advantage of existing storage volume within storm water inlets and is installed therein with little or no retrofitting necessary to secure the device. Storm water enters the apparatus where water energy is reduced and flow length is increased, increasing water detention time and allowing for the removal of soil sediment, floating debris, hydrocarbons and other pollutants utilizing settling tendencies and trapping areas. A damping system reduces pollutant resuspension and redirects high flows away from deposited sediment.
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This application is a continuation of PCT/JP96/02131 filed Jul. 29, 1996.
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is utilized for asynchronous transfer mode (hereinafter, "ATM") telecommunications. It relates to a telecommunications network and control system which, when a plurality of terminals which receive a best effort type service use the same route, the cell rates of the various terminals are controlled in such a manner that they rapidly approach values which are fair. This invention relates to rate control and traffic control in packet switching networks or ATM networks. It is provided in an ATM network and is utilized as a buffer means for temporarily storing cells or packets. This invention relates to techniques for controlling the prescribed intervals at which cells or packets are output to each connection. It also relates to congestion control, and in particular to the regulation of a cell rate and to the basis for cancelling this regulation. This invention also relates to techniques for setting up virtual paths (VPs) and virtual channels (VCs).
2. Background of Related Art
In a conventional best effort type service in an ATM network, in order to acquire information relating to congestion or acceptable bandwidth in a given route, cells for acquiring information (resource management cells: hereinafter, "RM cells") are sent back and forth between source and destination terminals, with the network writing information in these RM cells and the source-side terminals referring to this information and on this basis controlling their cell output rate.
For example, a service based on the available bit rate (ABR) protocol (See ATM Forum ATMF 95-0013R2), which is a typical best effort type service on an ATM network, is configured so that it begins by operating on the basis of the ABR protocol at all the nodes between the source and destination terminals, and at those terminals.
A prior art example of this will be explained with reference to FIG. 52-FIG. 57. FIG. 52 shows the overall constitution of a prior art ATM network. FIG. 53 shows the constitution of an RM cell. FIG. 54 and FIG. 55 are flowcharts showing the operation of a source-side terminal. FIG. 56 is a flowchart showing the operation of source-side and destination-side subscriber switches, and of a transit switch. FIG. 57 is a flowchart showing the operation of a destination-side terminal. The ATM network illustrated in FIG. 52 is constituted on the basis of the ABR protocol. In FIG. 52, numeral 20 and 40 represent switches which serve terminals, numeral 30 represents a transit switch, numeral 5 represents a transmission link, numeral 50-1 is a source-side terminal, and numeral 60-1 is a destination-side terminal. As shown in FIG. 53, an RM cell comprises an ATM header, a protocol identifier (ID), a direction identifier (DIR), a backward congestion notification (BN), a congestion indication (CI), a no-increase bit (NI) for prohibiting increase in the allowed cell rate, a request/acknowledgement (RA), the explicit rate (ER), the current allowed cell rate (CCR), the minimum cell rate (MCR), the queue length (QL), and the sequential number (SN).
RM cells are transmitted periodically between each pair of source and destination terminals. For example, source-side terminal 50-1 periodically outputs RM cells; transit switch 30 writes in these cells information relating to congestion in, or the acceptable bandwidth of, the route in question; and destination-side terminal 60-1 returns the cells. In this way, source-side terminal 50-1 is notified of whether there is congestion in that route.
According to the rules of the ABR protocol, source-side terminal 50-1 must transmit using a cell rate that does not exceed the allowed cell rate, termed the ACR.
When source-side terminal 50-1 receives a notification of congestion by means of an RM cell, it decreases the ACR on the basis of the ABR protocol. Conversely, when it has been notified that there is no congestion, it raises the ACR on the basis of the ABR protocol.
When one of the acceptable bandwidths of the network as notified by RM cells is the smallest, source-side terminal 50-1 changes to a cell rate that does not exceed whichever of this smallest value and the newly-computed ACR is the smaller. When the acceptable bandwidths of the network do not have a minimum value, source-side terminal 50-1 changes to a cell rate that does not exceed the ACR.
When a new virtual channel (VC) starts to transmit data, after it has transmitted an initial RM cell, it is allowed to transmit at a rate not exceeding the cell rate stipulated for the start of transmissions, which is called the initial cell rate (ICR).
After the initial RM cell has been returned, the cell rate is controlled by the same procedure as described above. FIG. 54 and FIG. 55 show the operation of source-side terminal 50-1 on the basis of an ABR protocol in the ATM network illustrated in FIG. 52. FIG. 56 shows the operation of switches 20, 30 and 40, and FIG. 57 shows the operation of destination-side terminal 60-1. As shown in FIG. 54, source-side terminal 50-1 generates an RM cell (S1), initializes this cell (S2) and outputs it (S3). The RM cell is returned by way of switch 20→switch 30→switch 40→destination-side terminal 60-1, whereupon it is received by source-side terminal 50-1 as shown in FIG. 55 (S11). If there is a congestion indication in the RM cell (S12), the ACR is decreased (S14), but if there is no congestion indication, the ACR is increased (S13). As a result, terminal 50-1 changes its cell output rate (S15).
As shown in FIG. 56, when switch 20, 30 or 40 receives an RM cell that has been output from source-side terminal 50-1 (S21), it writes an acceptable cell rate in the ER field (S22). If the switch has decided that there is congestion (S23), it writes a congestion indication in the CI field (S24). The switch then forwards the RM cell (S25).
As shown in FIG. 57, when destination-side terminal 60-1 receives an RM cell that has been output from source-side terminal 50-1 (S21), it writes an acceptable cell rate in the ER field (S22), and if it has decided that there is congestion (S23), it writes a congestion indication in the Cl field (S24). Destination-side terminal 60-1 then returns the RM cell (S26).
In conventional ABR, when congestion occurs due to a new terminal starting to transmit or to an increase in cell rate, and when notification is given of this congestion, each terminal that is notified decreases its cell rate, with the result that spare capacity is created. If notification is received that the congestion has been cleared, each terminal raises its cell rate again. Repeating this procedure constitutes a mechanism whereby a fair cell rate is gradually approached.
The control of cell rate will be further explained with reference to FIG. 58, which serves to explain cell rate control in an ATM network according to the prior art. It is assumed here that terminals 50-1 to 50-3 are sources and that connections 70-1, 70-2 and 70-3 are set up between these sources and respective destination terminals 60-1 to 60-3 via switches 20-40. These connections 70-1, 70-2 and 70-3 share transmission links 5 between switches 20-40. Cell rate control is performed as follows. Namely, source terminals 50-1 to 50-3 generate and insert management cells at fixed cell intervals, and send these management cells to destination terminals 60-1 to 60-3 and back again. Switches 20-40 write information in these cells and source terminals 50-1 to 50-3 refer to this information and on this basis perform cell rate control.
For example, a service based on the available bit rate (ABR) protocol (See ATM Forum ATMF 95-0013R2), which is a typical best effort type service on an ATM network, is configured so that it begins by operating on the basis of the ABR protocol at all the nodes between the source and destination terminals, and at those terminals.
A prior art example of this will be explained with reference to FIG. 52-FIG. 57. FIG. 52 shows the overall constitution of a prior art ATM network. FIG. 53 shows the constitution of an RM cell. FIG. 54 and FIG. 55 are flowcharts showing the operation of a source-side terminal. FIG. 56 is a flowchart showing the operation of source-side and destination-side subscriber switches, and of a transit switch. FIG. 57 is a flowchart showing the operation of a destination-side terminal. The ATM network illustrated in FIG. 52 is constituted on the basis of the ABR protocol. In FIG. 52, 20 and 40 represent switches which serve terminals, 30 represents a transit switch, 5 represents a transmission link, 50-1 is a source-side terminal, and 60-1 is a destination-side terminal. As shown in FIG. 53, an RM cell comprises an ATM header, a protocol identifier (ID), a direction identifier (DIR), a backward congestion notification (BN), a congestion indication (CI), a no-increase bit (NI) for prohibiting increase in the allowed cell rate, a request/acknowledgement (RA), the explicit rate (ER), the current allowed cell rate (CCR), the minimum cell rate (MCR), the queue length (QL), and the sequential number (SN).
RM cells are transmitted periodically between each pair of source and destination terminals. For example, source-side terminal 50-1 periodically outputs RM cells; transit switch 30 writes in these cells information relating to congestion in, or the acceptable bandwidth of, the route in question; and destination-side terminal 60-1 returns the cells. In this way, source-side terminal 50-1 is notified of whether there is congestion in that route.
According to the rules of the ABR protocol, source-side terminal 50-1 must transmit using a cell rate that does not exceed the allowed cell rate, termed the ACR.
When source-side terminal 50-1 receives a notification of congestion by means of an RM cell, it decreases the ACR on the basis of the ABR protocol. Conversely, when it has been notified that there is no congestion, it raises the ACR on the basis of the ABR protocol.
When one of the acceptable bandwidths of the network as notified by RM cells is the smallest, source-side terminal 50-1 changes to a cell rate that does not exceed whichever of this smallest value and the newly-computed ACR is the smaller. When the acceptable bandwidths of the network do not have a minimum value, source-side terminal 50-1 changes to a cell rate that does not exceed the ACR.
When a new virtual channel (VC) starts to transmit data, after it has transmitted an initial RM cell, it is allowed to transmit at a rate not exceeding the cell rate stipulated for the start of transmissions, which is called the initial cell rate (ICR).
After the initial RM cell has been returned, the cell rate is controlled by the same procedure as described above. FIG. 54 and FIG. 55 show the operation of source-side terminal 50-1 on the basis of an ABR protocol in the ATM network illustrated in FIG. 52. FIG. 56 shows the operation of switches 20, 30 and 40, and FIG. 57 shows the operation of destination-side terminal 60-1. As shown in FIG. 54, source-side terminal 50-1 generates an RM cell (S1), initializes this cell (S2) and outputs it (S3). The RM cell is returned by way of switch 20→switch 30→switch 40→destination-side terminal 60-1, whereupon it is received by source-side terminal 50-1 as shown in FIG. 55 (S11). If there is a congestion indication in the RM cell (S12), the ACR is decreased (S14), but if there is no congestion indication, the ACR is increased (S13). As a result, terminal 50-1 changes its cell output rate (S15).
As shown in FIG. 56, when switch 20, 30 or 40 receives an RM cell that has been output from source-side terminal 50-1 (S21), it writes an acceptable cell rate in the ER field (S22). If the switch has decided that there is congestion (S23), it writes a congestion indication in the CI field (S24). The switch then forwards the RM cell (S25).
As shown in FIG. 57, when destination-side terminal 60-1 receives an RM cell that has been output from source-side terminal 50-1 (S21), it writes an acceptable cell rate in the ER field (S22), and if it has decided that there is congestion (S23), it writes a congestion indication in the CI field (S24). Destination-side terminal 60-1 then returns the RM cell (S26).
In conventional ABR, when congestion occurs due to a new terminal starting to transmit or to an increase in cell rate, and when notification is given of this congestion, each terminal that is notified decreases its cell rate, with the result that spare capacity is created. If notification is received that the congestion has been cleared, each terminal raises its cell rate again. Repeating this procedure constitutes a mechanism whereby a fair cell rate is gradually approached.
The control of cell rate will be further explained with reference to FIG. 58, which serves to explain cell rate control in an ATM network according to the prior art. It is assumed here that terminals 50-1 to 50-3 are sources and that connections 70-1, 70-2 and 70-3 are set up between these sources and respective destination terminals 60-1 to 60-3 via switches 20-40. These connections 70-1, 70-2 and 70-3 share transmission links 5 between switches 20-40. Cell rate control is performed as follows. Namely, source terminals 50-1 to 50-3 generate and insert management cells at fixed cell intervals, and send these management cells to destination terminals 60-1 to 60-3 and back again. Switches 20-40 write information in these cells and source terminals 50-1 to 50-3 refer to this information and on this basis perform cell rate control.
For example, in the cell rate control used in the ABR protocol according to ATM Forum specifications (95-0013R2, 94-0983, 95-0195, etc.), in order to control the cell rate of each connection in accordance with the residual bandwidth and the requested bandwidth of a shared route in such manner that the cell rates are fair and congestion does not occur, the source terminals transmit management cells at fixed cell intervals and each switch through which these management cells pass reads the allowed cell rate of the terminals from the management cell and calculates (i) information relating to congestion relevant to the switch itself, and (ii) the acceptable cell rate. When a source terminal transmits, the maximum value which the allowed cell rate can have (i.e., the peak cell rate: PCR) in each connection is written in the management cells as the initial value of the acceptable cell rate. Only when the acceptable cell rate calculated by a switch is smaller than the acceptable cell rate written in a returned management cell does the switch write that calculated rate in the management cell and thereby notify the source terminal. The source terminal then sets its own ACR equal to or less than the notified acceptable cell rate, and proceeds to transmit cells at a rate not exceeding this ACR.
FIG. 59-FIG. 61 show the control flow at the switches. FIG. 59 shows the control when it has been decided that there is congestion. FIG. 60 shows the control when a management cell has arrived from a source-side terminal. FIG. 61 shows the control when a management cell is returning from a destination-side terminal. Each switch observes the queue length in the transmission queue cell buffer, and if the queue exceeds a threshold the switch decides that there is congestion at itself. If the queue does not exceed the threshold, the switch decides that there is no congestion. If the switch decides that there is congestion, then as shown in FIG. 59, it calculates the current allowed cell rate reduced by a fixed proportion and takes this as the acceptable cell rate at that switch.
This will now be explained with regard to the j th connection (j=1, 2, . . . , n). ERQ j is obtained by multiplying MACR j , which relates to this j th connection, by ERD, which is a constant that is less than 1 (S31). ERQ j is then taken as the acceptable cell rate (S32). When a management cell from a source terminal arrives, then as shown in FIG. 60 the current allowed cell rate written in that management cell is taken as ccr j (S41). Next, the value of:
ccr.sub.j ×min(1, R.sub.0 /rate.sub.j)
is obtained and set as the new allowed cell rate ccr j , which is then used to obtain the value of:
MACR.sub.j +(ccr.sub.j -MACR.sub.j)×AVF
which is set as the new MACR j (S42). Here, R 0 and AVF are constants, and rate j is the actual cell rate obtained from the current observation of the j th connection. As shown in FIG. 61, when a returning management cell arrives at a switch, the switch refers to the field value ER c in the management cell, this value serving to give notification of the acceptable cell rate. If ERQ j <ER c (S51), the switch replaces ER c in this management cell with ERQ j (S52). If ERQ j ≧ER c , the switch transfers this management cell towards the source terminal without modifying it (S53). Because the source terminal sets its ACR below the notified acceptable cell rate, its allowed cell rate (ACR) is decreased.
FIG. 62 shows the control flow at a switch when it has decided that there is no congestion. When a switch decides that there is no congestion, it makes its acceptable cell rate larger than the allowed cell rate. That is to say, it multiplies:
1-rate.sub.j /R.sub.0
by a constant which will be termed "Gain", adds 1 to this product and takes the result as ERX j . It also takes the product of this and ERQ j as the new ERQ j ; takes the smallest of this ERQ j , MACR j ×ERU, and R 0 , as the new ERQ j ; and takes the larger of this ERQ j and MACR j ×ERD as the new ERQ j (S61). The same control procedure is applied whether the management cell has arrived from the source side or is being returned from the destination side, and the result of this control procedure is that the ACR of the source terminal increases.
Next, an explanation will be given of conventional usage/network parameter control (UPC/NPC). ATM transfers information through a network after splitting it up into fixed-length packets called cells, and manages traffic on the basis of cell interval. In order to manage traffic in this way, a cell interval is stipulated for each connection, and a utilization monitor such as UPC/NPC is generally installed in order to monitor compliance with this cell interval. UPC/NPC immediately discards or tags any cells which arrive at shorter intervals than the stipulated cell interval.
However, because cells are transmitted asynchronously in an ATM network, each cell may be subject to a different delay while being transferred through the network. As a result, even if a subscriber has output cells in compliance with the stipulated cell interval, it will sometimes be impossible to satisfy the prescribed cell interval at a point where UPC/NPC is implemented. Cell delay variation (CDV) is the term used to describe fluctuation in cell transfer delay, and this CDV creates problems for UPC/NPC and traffic management. It has been proposed that the occurrence of CDV in a network could be reduced by traffic shaping, which is a technique whereby, once cells have been stored in a cell buffer, they are read from the buffer in a controlled manner.
An ABR service which has been much discussed in recent years in the ATM Forum is one which performs flow control by employing RM cells to give end-to-end notification of residual bandwidth on a given route. In an ABR service, the control loop comprising RM cells is closed end-to-end and therefore even if RM cells are dropped due to congestion, a negative feedback mechanism operates to restrict the flow of cells. Nevertheless, if cell transfer delay becomes large, as can happen in a public network, the information obtained by the RM cells relating to residual bandwidth on a given route will already be out-of-date, with the resulting problem that it is impossible to obtain a good control effect.
In order to overcome this problem, studies have been made of deploying VD/VS (virtual destination/virtual source) for closing control loops by means of RM cells at suitable places in the public network. In VD/VS, cell buffers are provided and cells are stored for each connection. Reading of cells from the cell buffers is performed by traffic shaping. When an RM cell, output from a source-side switch, returns after having been transferred through the network, a cell transmission interval for the connection in question is decided on the basis of the contents of the RM cell, and cells for that connection are read from the cell buffer at this interval.
If a higher layer protocol than the cell transmission layer provides a retransmission function, then when cells are dropped in the network, the retransmission function will operate, with the result that the degree of congestion may increase. In order to prevent this sort of slide into catastrophically serious congestion, it is essential to regulate the volume of traffic entering the network when the network has become congested.
The following method has previously been proposed for this purpose. Namely, as found in Chaki, "An Examination of Cell Level Congestion Clearing Systems" (Preprints of the Switching Systems Technical Group of the IEICE Japan, SSE 94-97), it is proposed that the volume of traffic should be regulated by a fixed factor when congestion has occurred. According to this method, if congestion occurs, the volume of traffic is regulated by a prescribed factor, and if the congestion is not cleared within a prescribed time, continued attempts are made to overcome the congestion by progressively making the regulation factor more stringent. When the congestion is cleared, the regulation factor is successively relaxed and there is a shift to a normal state.
In multimedia communications implemented on an ATM network, the connections exhibit a wide range of peak rates and average rates. For this reason, the different peak rates and average rates are divided into what are called "call types", and the call admission control (CAC) is carried out so as to meet the requested call quality for each call type.
The symbols used in this specification will now be defined. r i and a i are respectively the peak rate and the average rate of call type i, and a all and C are respectively the sum of the average rates of all the VCs, and the VP bandwidth. CLR AVE is the average cell loss ratio for all call types.
Letting the cell rate probability density function for call type i be f i (x), and the cell rate probability density function for the other call types apart from call type i be F i (x), then the cell loss ratio for call type i, CLR i , can be obtained by as: ##EQU1## (see T. Murase, H. Suzuki, S. Sato and T. Takeuchi, "A call admission control scheme for ATM networks using a simple quality estimate". IEEE J. Select. Areas Commun., Vol.9 (No.9): pp.1461-1470, December 1991). In call admission control, a connection request is accepted if the largest of the cell loss ratios obtained for the different call types by means of Eq.1 satisfies a certain standard value.
FIG. 63 serves as a numerical example of the case where CAC is carried out with a stipulated value of 10 -6 for cell loss ratio. It is assumed in FIG. 63 that call type 1 has peak rate r 1 =10 Mb/s and average rate a 1 =0.05 Mb/s, and that call type 2 has peak rate r 2 =1.5 Mb/s and average rate a 2 =0.15 Mb/s. FIG. 63 shows the cell loss ratio and the number of connections for each call type in a multiple access environment. The number of call type 1 connections is plotted along the horizontal axis, the number of call type 2 connection is plotted along the left-hand vertical axis, and cell loss ratio (CLR) is plotted along the right-hand vertical axis. From FIG. 63 it can be seen that:
1) Call type 1 has a higher cell loss ratio than call type 2. Under some circumstances there is more than an order of magnitude difference.
2) Even though the average cell loss ratio is more than an order of magnitude lower than the stipulated value, the cell loss ratio of call type 1 approaches the stipulated value.
Thus, in an ATM network intended for multimedia communications, because the connections exhibit a wide range of cell rates, and because any notified information relating to residual bandwidth on a given route will be out-of-date if the distance to the terminals is large, it is difficult to obtain a good control effect. For example, the transmission of RM cells takes time, and it takes time for a newly-transmitting terminal to control the ACR of a terminal which is already transmitting. Consequently, it takes time to converge to a fair allocation of bandwidth. Adequate tracking of cell rate and network conditions is also difficult, since these change from moment to moment.
To shorten the time required to raise the ACR, the ICR of each terminal can be set on the high side, but this still leaves the problem that an appreciable amount of time is taken to notify a terminal of congestion if the distance to the terminal is large. Various measures are then required to deal with the problem of congestion, such as ensuring that long buffers are employed in the network and decreasing the network utilization.
Even if the distance to terminals is short, it still takes a certain amount of time to converge to a cell rate which is fair, and so there is a potential need to reduce this time.
In the prior art, the acceptable cell rates of connections routed through the same switch are increased or decreased on the basis of the same congestion situation. This amounts to control which performs a uniform operation, i.e. making a uniform increase or decrease in the ACRs, and this will not always be fair.
When traffic shaping is carried out, for example in the case of the VD/VS scheme described above, cell buffer queues will be more frequent when the number of connections increases, and the increased memory etc. needed to deal with this means that the hardware scale expands. In traffic shaping, only one cell can be transferred per slot, and if a plurality of cells are scheduled for the same slot, some of them will not be transferred. This becomes an actual rather than a potential problem if the number of connections increases, since then there is a high probability that a plurality of cells will be scheduled for the same slot.
When there is severe congestion, it takes time for the congestion to clear. Because the increase in traffic immediately after cell rate regulation has been cancelled is not taken into account when relaxing the regulation, repetitions of relaxation followed immediately by more severe regulation occur, and it takes time to move to a steady state.
When there are many call types, CAC has to be performed with an awareness of the cell loss ratio of each call type. If cell loss ratio is calculated rigorously in accordance with Eq.1, convolution will be necessary for each call type, and therefore in a multimedia environment where there are a large number of call types, the computational requirements will be very high.
Because CAC involves deciding whether or not to accept a connection request when that connection is being set up, a high degree of responsiveness is needed in order to offer a real-time switching service.
The present invention has been made in the light of this technical background. The various objects of this invention include the following to provide a dynamic rate control system whereby the cell rates of a plurality of terminals in a best effort type service can be controlled fairly; (2) to provide a dynamic rate control system capable of causing the cell rates of a plurality of terminals to converge rapidly to fair values; (3) to provide a dynamic rate control system whereby even when the distances to a plurality of terminals are large, the cell rate of each terminal can be controlled fairly without causing transmission delays; (4) to provide a dynamic rate control system capable of changing the bandwidth that can be utilized by each connection so that it becomes as large as possible, while ensuring that the acceptable cell rates notified to the various connections are fair; (5) to provide a dynamic rate control system capable of implementing traffic shaping by means of comparatively modest hardware even when there are a large number of connections; (6) to provide a dynamic rate control system capable of transferring a plurality of cells scheduled for the same slot (i.e., for the same time); (7) to provide a dynamic rate control system capable of increasing the throughput of an ATM network; (8) to provide a dynamic rate control system capable of clearing congestion rapidly; (9) to provide a dynamic rate control system capable of improving the responsiveness of the CAC by calculating the cell loss ratio for each call type by means of a simple calculation even when there are a large number of call types; (10) and to provide a dynamic rate control system capable of performing smooth call admission control.
SUMMARY OF THE INVENTION
This invention is characterized in that a switch which serves a plurality of terminals that receive a best effort type service has a control system for causing the cell rates of the terminals to converge rapidly to a rate which is fair among those terminals.
In the prior art, cells for collecting information were sent back and forth between source and destination terminals, the ATM network wrote congestion information and information relating to acceptable bandwidth in these cells, destination-side terminals returned these cells, and source-side terminals controlled cell rate simply by referring to the information in these cells. The present invention differs from the prior art in respect of network constitution, the way in which the timing of the cell rate control is set, the cell rate control logic, and the speed with which cell rates converge.
Namely, this invention is a dynamic rate control system which serves a multiplicity of terminals, and which has means for setting a virtual path for one of these terminals on the basis of a request from that terminal. One feature of this invention is that it comprises: means for collecting route information which includes information relating to the residual bandwidth of the virtual path once the path has been set up after a cell rate has been specified for the terminal; means for holding the cell rate requested by the aforesaid terminal. The invention also includes and control means which, on the basis of the aforesaid route information, dynamically controls the cell rate of the virtual path once it has been set up, controlling it so that it is as large as possible, up to the cell rate requested by that terminal, and so that it is fair to the plurality of terminals from which there are connection requests. The aforesaid control means preferably has means which computes and sets the cell rate allowed at the aforesaid terminal.
A switch which serves a terminal collects VP information or route information irrespective of whether or not this terminal is transmitting cells. As a result, when the switch receives a request from the terminal to start transmission, it can rapidly compute the cell rate and reply to the terminal with either an acceptance or a rejection of the transmission start request.
The aforesaid residual bandwidth information is numerical information, and the aforesaid means which computes and sets the allowed cell rate can include means which computes the aforesaid allowed cell rate by multiplying the residual bandwidth information by a constant C (0<C≦1). The value of the constant C can be set appropriately after consideration of the characteristics of the ATM network, the kinds of information, and other factors.
It is desirable to have means which, when the minimum cell rate included in the aforesaid transmission start request from a terminal is smaller than the aforesaid allowed cell rate, sets the initial cell rate of the terminal in question to the aforesaid allowed cell rate.
The present invention is characterized in that RM cells are not sent and received between switches that serve terminals, and the decision to accept or reject a transmission start request is made after the request has been sent from a terminal, with the result that less time is taken for the cell rate to be set. Therefore, if the minimum cell rate included in the transmission start request is smaller than the aforesaid allowed cell rate, the cell rate of the terminal is rapidly increased.
An increase in the allowed cell rate can be carried out stepwise in unit increments. The amount by which a terminal can be made to increase its cell rate at one time is set in advance, and this is taken as the unit increment. When the allowed cell rate is greater than this unit increment, the cell rate is increased by the unit increment. After the increase, the same procedure is carried out again. Namely, if the allowed cell rate is still greater than the unit increment, the cell rate is once again increased by the unit increment. The cell rate of a terminal can be increased rapidly by repeating this procedure. Rather than increasing the cell rate gradually while observing the state of the entire route, a unit increment is set in advance and the cell rate increased in one pass by that unit increment. The decision to make this increase is taken by the subscriber switch alone. As a result, the cell rate of a terminal can be increased rapidly in stepwise fashion.
The aforesaid route information is a quantity which shows, in stepwise manner, the residual bandwidth of the virtual paths contained in the route in question, and the aforesaid means which computes and sets the allowed cell rate can also include means which sets the allowed cell rate uniquely in accordance with this quantity. For example, the cell rate can be computed by setting a plurality of thresholds for the residual bandwidth and comparing with these thresholds. It is also possible to select the terminal which should be notified of congestion by setting thresholds for the cell rates of the terminals and by taking these into consideration along with the results derived from the residual bandwidth.
Alternatively, the aforesaid route information can be a quantity which shows, in stepwise manner, the queue lengths in the cell buffers provided at the nodes contained in that route; and the aforesaid means which computes and sets the allowed cell rate can include means which sets the allowed cell rate uniquely in accordance with this quantity. For example, the cell rate can be computed by providing a plurality of thresholds for the cell buffer queue length and comparing with these thresholds. It is also possible to select the terminal which should be notified of congestion by setting thresholds for the cell rate of the terminals as well, and by taking these into consideration along with the results derived from the cell buffer queue length.
When an ATM network according to this invention also has switches which transmit RM cells for notifying the aforesaid route information to other switches, it is desirable if the aforesaid means which computes and sets the allowed cell rate includes means which discards received RM cells.
For example, when a subscriber switch computes the cell rate and notifies a terminal by writing the results of the computation in an RM cell, if there is another RM cell that has arrived from elsewhere, the subscriber switch should recognize this other RM cell and discard it. In this way, malfunctioning of the terminal due to a plurality of different data can be avoided.
The invention can also be configured so that the aforesaid control means comprises: notifying means which notifies information relating to the acceptable cell rate to the source-side terminals of connections which it serves; means which collects and holds various information relating to the plurality of connections which it serves and which share a transmission link, said information comprises the allowed cell rate and the actual cell rate of each connection, the total bandwidth and the total input bandwidth of the shared transmission link, and the number of connections which share this transmission link. The control means further includes means which calculates for each connection, on the basis of the information held in this collecting and holding means, the acceptable cell rate which the aforesaid notifying means notifies to the source-side terminals.
In this way, rather than change the acceptable cell rate notified to the various connections so that all the cell rates increase or all the cell rates decrease, it is possible to give notification of acceptable cell rates which have been individually rewritten so as to provide results having improved fairness. It is also possible to rewrite and give notification of an acceptable cell rate for each connection so as to increase the bandwidth that each connection can utilize without resulting in congestion.
The invention can also be configured so that the aforesaid control means comprises: means which, when a terminal which it serves becomes a source terminal, provides notification to that terminal information relating to the acceptable cell rate; and means which collects and holds various information relating to the connection over which the terminal which it serves becomes a source terminal, and relating to the plurality of connections that share the route. The information comprises the allowed cell rate and the actual cell rate of each connection, the bandwidth and the total input bandwidth of the shared route, and the number of connections which share this route. The control means further includes means which calculates for each connection, on the basis of the information held in this collecting and holding means, the acceptable cell rate which the aforesaid notifying means provides notification. In this way, a terminal that becomes a source terminal can be notified of the acceptable cell rate simply by the switch that serves that terminal.
This reduces the load placed on switches in the network in generating and notifying management information. Moreover, when the cell rate of any connection changes, the time taken to calculate an acceptable cell rate in response to this change can be shortened and the source terminal can be notified more rapidly. Furthermore, the calculation only has to be performed by the switch which serves the terminal, without all the switches calculating acceptable cell rates. Finally, cell rate can be controlled promptly when transmission begins over a new connection.
The information which the aforesaid notifying means notifies to a terminal may be the cell rate data itself, or it may be information that indicates an increase or a decrease of the allowed cell rate. When the latter information is used, the allowed cell rate of a terminal is increased or decreased in accordance with a predefined calculation formula.
In the foregoing constitution, the calculating means may include computing means which uses the variance of the ratio of allowed cell rate to requested rate for each connection as an evaluative function, this variance being provided by: ##EQU2## and obtains, for connection j (j=1, 2, . . . , n), the acceptable cell rate ERQ j at that switch by means of:
ERQ.sub.j =ccr.sub.j -α.sub.j ·sign{n·ccr.sub.j /r.sub.j -w·Σ.sub.i ccr.sub.i /r.sub.i }
where Σ i and Σ j are respectively the sums from i=1 to i=n and from j=1 to j=n, ccr j and r j are respectively the allowed cell rate and the requested cell rate of connection j, and n is the number of connections transmitting data. α j and w are weighting functions, and sign{ } is a function that indicates the sign of the value inside the curly brackets.
α j may also be a positive constant, and may be taken as equal to the absolute value of:
{n·ccr.sub.j /r.sub.j -w-Σ.sub.j ccr.sub.i /r.sub.i }
When a constant is used as α j , ERQ j changes faster with larger values of α j , but any error becomes larger. Conversely, if α j is small, the value of ERQ j obtained is accurate, but more time is taken for ERQ j to change. α j should therefore be set with due regard to these considerations.
w is regarded as a decreasing function of the total input bandwidth of the transmission link or route shared by the connections. Specifically, w may be taken as a function of the total bandwidth B all and the total input bandwidth B use of the transmission link or route shared by the connections:
w=(B.sub.all +p.sub.1)/(B.sub.use +p.sub.2)×p.sub.3
where p 2 is a constant for preventing the denominator becoming zero, p 1 is a constant for correcting p 2 , and p 3 is a constant for setting the allowable width. It is also possible for w to be taken as a function of the total input bandwidth B use of the transmission link or route shared by the connections:
w=-p.sub.4 ·B.sub.use +p.sub.5
where p 4 is a positive constant for setting the allowable width and p 5 is a correction constant.
When the rate requested for a connection is not clear and the terminal is transmitting at or above a fixed proportion of the current allowed cell rate, the maximum value that can be taken by the allowed cell rate in that connection may be regarded as the requested rate. Otherwise, the minimum value that can be taken by the allowed cell rate may be regarded as the requested rate.
Terminals may sometimes transmit at a rate which, instead of conforming to the rate instructed by the ERQ j , exceeds this. When this rate happens, in order to guarantee that transfer to the next switch will be carried out at the prescribed cell rate ERQ j , i.e. at the prescribed cell interval, the following can be provided: (i) a connection table including addresses which are connection identifiers, and which comprises records such as tokens, cell intervals and pointers to the cell buffer; (ii) a cell buffer comprising records such as pointers indicating the order among the entries, and fields which hold the cells themselves; (iii) a simultaneous arrival connection list comprising records such as pointers which indicate the order among the entries, and connection identifiers; (iv) a scheduling table holding pairs of times and pointers to the simultaneous arrival connection list; (v) a timer which shows which entry in the scheduling table is to be processed; and (vi) a timer which shows the current time. With such a constitution, the following control can be performed. Namely, a list is formed in the cell buffer for each connection; the addresses of the heads and tails of these lists are entered in the connection table; every time a cell arrives, that cell is added to the list for the relevant connection; if there is a token, transfer scheduling is carried out at that time. In addition, a list of the connection identifiers of cells to be read at the same time is formed in the simultaneous arrival connection list, and this list is read in consecutive order starting from the address shown by the timer which indicates which entry in the scheduling table is to be processed, whereby cells of various connections are read in the order in which they were scheduled. After they have been read, they are scheduled at the cell intervals shown by the connection table, thereby guaranteeing the cell interval prescribed for each connection.
Because efficient use can be made of memory capacity by using a shared buffer as the cell buffer, it is possible to restrict the increase in hardware that would otherwise accompany an increase in the number of connections. Furthermore, because this control scheme ensures that cells which arrive simultaneously are read sequentially, the number of discarded cells can be reduced. A high throughput ATM network can therefore be achieved.
The invention can also be configured so that the aforesaid control means comprises: an input terminal at which the cell stream arrives; a cell buffer which temporarily stores the cells which have arrived; a traffic shaper which read cells from the cell buffer in accordance with indicated cell transmission intervals; and a connection table the addresses of which are connection identifiers (VPINVCI) and which holds connection information that includes information relating to the aforesaid cell transmission intervals (Int). The aforesaid cell buffer comprises a plurality of memory regions each accommodating a single cell, and pointer regions which show pointer values (Ptr) that map these memory regions to the aforesaid connection table.
The aforesaid connection information may include the pointers of the aforesaid memory regions. These pointers accommodate the head and tail addresses of cells which have the same connection identifier as the corresponding connection identifier in the connection table.
The plurality of cells stored in the aforesaid cell buffer may be formed into chains by the aforesaid pointers. The cells will then be read from the cell buffer in the order in which they have been linked by these chains, and in accordance with the indicated cell transmission intervals.
The aforesaid connection information may include a token (Tk) indicating whether or not cell output scheduling is allowed after the arrival of the tail cell of the connection in question.
It is desirable to provide means for holding the head pointer and the tail pointer of a free memory region of the aforesaid cell buffer.
The invention can also be configured with a timer which counts the current time, and scheduling means which schedules cell output in accordance with this timer.
The aforesaid scheduling means can also comprise scheduling means which, when a plurality of cells arrive at practically the same time and the scheduled output times of this plurality of cells overlap, causes cells to be output after their overlapping scheduled cell output times are successively shifted. As a result, a plurality of cells which have arrived at approximately the same time in an overlapping manner, and which have overlapping scheduled cell output times, can all be output with any being discarded, by adjusting the scheduled cell output times. Accordingly, cell loss ratio can be decreased.
The invention can also be configured so that the aforesaid scheduling means comprises, in addition to the aforesaid timer, a virtual timer which, for the aforesaid plurality of cells with overlapping scheduled cell output times, stops counting until all the cells have been output.
The invention can also be configured so as to comprise: a simultaneous arrival connection list which includes (i) memory regions in which are accommodated the connection identifier information for the plurality of connections in which the aforesaid scheduled cell output times overlap, (ii) pointer regions which correspond with these memory regions, and which show the pointers that have been assigned to these memory regions; and means for holding the head pointer and the tail pointer of a free memory region of the simultaneous arrival connection list.
The invention can also be configured so that the aforesaid scheduling means includes means which indicates in advance the plurality of scheduled cell output times.
The aforesaid memory regions of the cell buffer may have an upper limit for the number of cells stored for each connection.
The aforesaid connection information may contain priority information concerning the cell output order.
An alternative control method is to clear congestion rapidly when it occurs by setting a regulation factor adaptively in accordance with the congestion, and by taking into account the traffic increase that occurs when the regulation is cancelled.
The invention can also be configured so that the aforesaid control means includes: means which measures the cell flow; means which compares this measured cell flow with a threshold; means which, in accordance with the result of this comparison, sends regulation information to the terminal constituting the source of the cells, said regulation information including a cell flow regulation factor; and means which, when regulation is being applied to a source terminal, maintains this regulation until the measured cell flow from that source terminal reaches a preset value below the aforesaid threshold.
It is desirable to set the aforesaid regulation factor R to R=1/λ where λ is the normalized cell flow and the normalized threshold Λ is 1. It is desirable to set the regulation factor R to R=1 when λ<1/R.
The invention may also comprise a table which holds the cell output rates of a plurality of cell generators, and a multiplier which multiplies these cell output rates by the aforesaid regulation factor. The aforesaid means which sends regulation information to a terminal that constitutes a source terminal sends, as the regulation information, the value of the regulated cell output rate. As a result, because a source terminal can receive the cell output rate as the regulation information, there is no need to calculate the cell output rate from the regulation factor at the terminal side.
The invention can also be configured so as to have a cell buffer which temporarily stores cells, and so that the aforesaid measuring means measures the cell flow from the number of cells stored in this cell buffer.
The invention can also be configured so that the aforesaid comparison means has means which observes the variation in the results of the comparison over a set time.
With this constitution, it is also possible to set a plurality of the aforesaid regulation factors (R, R', R"), and to apply these plurality of regulation factors stepwise in accordance with the observation results of the means which observes the aforesaid changes.
For example, the aforesaid plurality of regulation factors R, R' and R" may be respectively taken as:
R=1/λ0(Xλ0>1)
R'=R/λ1(λ1>λ0>1)
R"=R/λ2(R<λ2<1)
where λ0, λ1 and λ2 are the cell flows at different measurement times, and threshold Λ is taken as 1.
Still more precise cell flow control can be performed by controlling in this stepwise manner.
The following control may also be performed. Namely, the average cell loss ratio is obtained from the peak rate and the average rate of all the connections that are set. The result of dividing the sum of the average rates of all the connections by the link capacity is taken as a first safety factor. The result of dividing the peak rates of each connection by the average rate is taken as a second safety factor. The result of multiplying the first safety factor and the second safety factor by the average cell loss ratio is taken as the cell loss ratio of each connection. A connection request is accepted only when the largest cell loss ratio of the connections satisfies a certain standard value.
For example, the cell loss ratio CLRI for call type i is provided rigorously by Eq. 1. In Eq.1, the term x/z indicates the proportion of the overflow accounted for by call type i when the cell rate from all connections exceeds the VP bandwidth. The smallest denominator of this term x/z will be C, and the numerator will be largest when the connection in question is outputting cells at its maximum rate. In other words, the largest numerator will be ri. Accordingly, x/z≦r i /C. It follows that: ##EQU3## In other words, Eq.2 is a formula which gives a safe assessment of the cell loss ratio.
The distinguishing feature of this control means is that Eq.2 has been derived as a safe approximation for the cell loss ratio of call type i. An exact solution of Eq.1 requires convolution for each call type, and if there are many call types an enormous amount of calculation would be required in the call admission control to obtain the cell loss ratio for each call type. By using a scheme based on Eq.2, convolution has to be performed only once in order to obtain the average cell loss ratio CLR AVE , and because the cell loss ratio for each call type can be found simply by multiplying the average cell loss ratio by a safety factor, the amount of calculation required can be cut drastically compared with the prior art scheme. The effect of this control scheme really becomes pronounced in a multimedia environment when there are a large number of call types.
In other words, the invention can also be constituted so that the aforesaid control means includes means which decides whether or not to accept a connection request from a terminal in accordance with the cell loss ratio. This decision means comprises: means which computes the cell loss ratio CLR i of the i th group; and means which permits the connection of a group which satisfies this cell loss ratio CLR i .
It is desirable if the aforesaid means which computes the cell loss ratio CLR i classifies the plurality of connection requests into i groups in accordance with their peak rate and average rate, and computes the cell loss ratio CLR i of the i th group as:
CLR.sub.i ≦(a.sub.all /c)·(r.sub.i /a.sub.i)·CLR.sub.AVE (Eq. 2)
where, for all this plurality of connection requests, CLR AVE is the average cell loss ratio, a all is the sum of the average rates, c is the VP bandwidth, r i is the peak rate of group i, and a i is the average rate of group i.
As has been explained above, the present invention enables the cell rates of a plurality of terminals in a best effort type service to be controlled fairly. It can also make the cell rates of a plurality of terminals converge rapidly to fair values. Even when the distances to a plurality of terminals are large, this invention enables the cell rate of each terminal to be controlled fairly without making transmission delay a problem. It can change the bandwidth that can be utilized by each connection so that it becomes as large as possible, while ensuring that the acceptable cell rates notified to the various connections are fair. Even when there are a large number of connections, it can implement traffic shaping through comparatively modest hardware. It can transfer a plurality of cells that have been scheduled for the same slot (i.e. for the same time). It can increase the throughput of an ATM network, clear congestion rapidly, and improve the responsiveness of the CAC by calculating the cell loss ratio for each call type by means of a simple calculation, even when there are a large number of call types. It can also perform smooth call admission control.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows the overall constitution of a first embodiment of this invention.
FIG. 2 is a block diagram of the essential parts of the switch that serves the source-side terminals.
FIG. 3 is a block diagram of the transit switch and the switch that serves the destination-side terminals.
FIG. 4 is a flowchart showing the operation of a switch serving source-side terminals.
FIG. 5 shows the essential parts of an ATM network according to a second embodiment of this invention.
FIG. 6 represents the state of bandwidth utilization in an ATM network prior to the application of control according to the second embodiment of this invention.
FIG. 7 represents the operation of the second embodiment and the resulting changes in utilized bandwidth.
FIG. 8 is a flowchart representing the operation of a source-side switch in this second embodiment of the invention.
FIG. 9 shows the essential parts of an ATM network according to a third embodiment of this invention.
FIG. 10 represents the bandwidth utilized by each terminal at a certain point in time.
FIG. 11 represents the relation between thresholds in the third embodiment of the invention, and the peak cell rate and minimum cell rate of the source-side terminals.
FIG. 12 represents the relation between residual bandwidth and various thresholds in the third embodiment of the invention.
FIG. 13 is a flowchart of the algorithm used by a switch to notify terminals of congestion.
FIG. 14 shows the relations among residual bandwidth, the cell rate of the terminals, and the contents of the corresponding congestion notification.
FIG. 15 shows the overall constitution of an ATM network according to a fourth embodiment of this invention.
FIG. 16 represents the relation between residual bandwidth and various thresholds in the fourth embodiment.
FIG. 17 is a flowchart of an algorithm that enables a switch to control the cell rates of the source-side terminals.
FIG. 18 shows the relations among the largest buffer utilization, the cell rate of the source-side terminals, and the contents of the corresponding congestion notification.
FIG. 19 shows the overall constitution of a sixth embodiment of this invention.
FIG. 20 shows the control flow of a switch.
FIG. 21 shows the overall constitution of a seventh embodiment of this invention.
FIG. 22 shows the overall constitution of an ATM network according to an eighth embodiment of this invention.
FIG. 23 is a block diagram of a dynamic rate control system according to the eighth embodiment of this invention.
FIG. 24 shows the essential parts of the eighth embodiment of this invention.
FIG. 25 shows how cells are written to the cell buffer.
FIG. 26 shows how the connection list is rearranged.
FIG. 27 shows how the connection list is rearranged.
FIG. 28 shows how cells are fetched from the cell buffer.
FIG. 29 shows the essential parts of a ninth embodiment of this invention.
FIG. 30 shows the essential parts of a tenth embodiment of this invention.
FIG. 31 shows the essential parts of an eleventh embodiment of this invention.
FIG. 32 shows how connection identifiers are written to the simultaneous arrival connection list.
FIG. 33 shows how connection identifiers are written to the simultaneous arrival connection list.
FIG. 34 shows how connection identifiers are fetched from the simultaneous arrival connection list.
FIG. 35 is a flowchart showing the operation of the eleventh embodiment of this invention.
FIG. 36 shows the essential parts of a twelfth embodiment of this invention.
FIG. 37 shows the essential parts of a thirteenth embodiment of this invention.
FIG. 38 shows the essential parts of a fourteenth embodiment of this invention.
FIG. 39 is a block diagram of a dynamic rate control system according to a fifteenth embodiment of this invention.
FIG. 40 is a flowchart showing the operation of the dynamic rate control system according to the fifteenth embodiment of this invention.
FIG. 41 shows the operation of the fifteenth embodiment of this invention in terms of the relation between cell flow λ and time.
FIG. 42 shows the operation of the fifteenth embodiment of this invention in terms of the relation between cell flow λ and time.
FIG. 43 is a block diagram of a dynamic rate control system according to a sixteenth embodiment of this invention.
FIG. 44 is another block diagram of a dynamic rate control system according to the sixteenth embodiment of this invention.
FIG. 45 is a block diagram of a dynamic rate control system according to a seventeenth embodiment of this invention.
FIG. 46 is a block diagram of a dynamic rate control system according to an eighteenth embodiment of this invention.
FIG. 47 is flowchart showing the operation of a dynamic rate control system according to the eighteenth embodiment of this invention.
FIG. 48 serves to explain a dynamic rate control system according to a nineteenth embodiment of this invention.
FIG. 49 is a flowchart showing the operation of the congestion detector and the congestion controller in the nineteenth embodiment of this invention.
FIG. 50 is a flowchart showing the operation of a dynamic rate control system according to a twentieth embodiment of this invention.
FIG. 51 shows a call type management table.
FIG. 52 shows the overall constitution of a prior art ATM network.
FIG. 53 shows the constitution of an RM cell.
FIG. 54 is a flowchart showing the operation of a source-side terminal.
FIG. 55 is a flowchart showing the operation of a source-side terminal.
FIG. 56 is a flowchart showing the operation of source-side and destination-side subscriber switches and of a transit switch.
FIG. 57 is a flowchart showing the operation of a destination-side terminal.
FIG. 58 serves to explain cell rate control in an ATM network according to the prior art.
FIG. 59 shows the control flow at a switch.
FIG. 60 shows the control flow at a switch.
FIG. 61 shows the control flow at a switch.
FIG. 62 shows the control flow at a switch when it has been decided that there is no congestion.
FIG. 63 shows the relation between cell loss ratio and the number of connections for each call type in a multiple access environment.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
(First embodiment)
The constitution of a first embodiment of this invention will be explained with reference to FIG. 1-FIG. 3. FIG. 1 shows the overall constitution of this first embodiment. FIG. 2 is a block diagram of the essential parts of the switch that serves the source-side terminals. FIG. 3 is a block diagram of the transit switch and the switch that serves the destination-side terminals. In FIG. 1, 50-1 and 50-2 are source-side terminals, block 20 is the switch that serves source-side terminals 50-1 and 50-2, 30 is a transit switch, block 40 is the switch that serves the destination-side terminals, 5 is a transmission link and 60-1 and 60-2 are the destination-side terminals. In FIG. 2, block 10 is a route information collector and 12 is a cell rate computation and block control part. In FIG. 3, block 14 is a route information output part.
This first embodiment of the invention is a dynamic rate control system which serves terminals 50-1 and 50-2, wherein switches 20, 30 and 40 have means for setting up a VP for one of these terminals 50-1 or 50-2 on the basis of a request from the terminal. Means for setting up this VP are provided in each of switches 20, 30 and 40 and in each of terminals 50-1, 50-2, 60-1 and 60-2, but because this is not an essential part of this invention, it is not illustrated.
The first embodiment of the invention comprises: route information collector 10 as means for collecting route information which includes information relating to the residual bandwidth of the VP once this has been set up after a cell rate has been specified for a terminal 50-1 or 50-2; and cell rate computation and control part 12 which serves for holding the cell rate requested by a terminal 50-1 or 50-2, and as a control means which, on the basis of the aforesaid route information, dynamically controls the cell rate of the virtual path once this has been set up. The control means controls the cell rate so that it is as large as possible, up to the cell rate requested by that terminal, and so that it is fair to the plurality of terminals from which there are connection requests. Cell rate computation and control part 12 has means which computes and sets the allowed cell rate for terminals 50-1 and 50-2.
Source-side terminals 50-1 and 50-2 make calls on the basis of the ABR protocol. Switch 20 enables connections to be established by emulating the ABR protocol for source-side terminals 50-1 and 50-2. It is not essential for switches 30 and 40 and destination-side terminals 60-1 and 60-2 to operate on the basis of the ABR protocol. However, periodically, or when there has been a state change, switches 30 and 40 must notify switch 20 of the state of utilization of the route in question, this state serving as route information. The current unutilized bandwidth is calculated on the basis of the state of utilization notified to switch 20, or on the basis of cell output from terminals 50-1 and 50-2, or on the basis of both these data.
The operation of switch 20 when there has been a request from terminal 50-1 or 50-2 to start a new transmission via a given route, will be explained by means of FIG. 4, which is a flowchart showing the operation of switch 20 which serves source-side terminals 50-1 and 50-2. When a request to start transmission has newly arrived from terminal 50-1 or 50-2 (S70), the value obtained by multiplying the residual bandwidth by a constant C (0<C≦1) is taken as the initial cell rate ICR of the transmission (S71). Constant C is a parameter determined so as to avoid the situation in which the wrong cell rate is set because the information pertaining to the time at which the transmission start request was accepted deviates from the current situation. If the ICR is smaller than the minimum cell rate (MCR) requested by source-side terminal 50-1 or 50-2 (S72), it would be dangerous to accept the transmission start request at this cell rate, and it is therefore necessary to re-negotiate with source-side terminal 50-1 or 50-2. Until this is done, the transmission start request cannot be granted (S73). If the ICR is larger than the MCR (S72), transmission at the ICR is allowed (S74). This first embodiment of the invention makes it possible to decide immediately whether to accept or reject a new transmission start request from source-side terminal 50-1 or 50-2, whereupon transmission at the ICR from accepted source-side terminals 50-1 and 50-2 can be allowed.
(Second embodiment)
A second embodiment of this invention will be explained with reference to FIG. 5-FIG. 8. FIG. 5, shows the essential parts of an ATM network according to this second embodiment, wherein blocks 50-1, 50-2 and 50-3 are source-side terminals which make calls in accordance with the ABR protocol; 20 is the switch serving the source-side terminals, the switch emulating the ABR protocol for each terminal; and block 5 is part of a route shared by source-side terminals 50-1, 50-2 and 50-3. FIG. 6 represents the state of bandwidth utilization in the ATM network of FIG. 5 prior to the application of control according to this second embodiment of the invention. In FIG. 6, W total is the total bandwidth of the route in question, Wa is the residual bandwidth of this route, W1 is the utilized bandwidth of source-side terminal 50-1, W2 is the utilized bandwidth of source-side terminal 50-2, and W3 is the utilized bandwidth of source-side terminal 50-3. In FIG. 6, immediately after source-side terminal 50-3 has transmitted an initial RM cell at time t0, it starts to transmit data at the initial cell rate ICR shown by W3.
FIG. 7 represents the operation of this second embodiment and the resulting changes in utilized bandwidth. When the value obtained by multiplying the residual bandwidth Wa by the constant C (0<C≦1) is larger than the unit increase in unit time of the cell rate of source-side terminal 50-3, which began transmitting at cell rate ICR at t0, an RM cell serves to notify that there is no congestion is generated at switch 20. This RM cell is transmitted to source-side terminal 50-3, thereby allowing an increase in the cell rate. In FIG. 7, source-side terminal 50-3 receives the RM cell at time t1 and increases its cell rate. Thereafter, if the value obtained by multiplying the residual bandwidth Wa by the constant C is still the larger, switch 20 generates and transmits another RM cell. FIG. 8 is a flowchart representing the operation of switch 20 in this second embodiment of the invention. If there is residual bandwidth (S80), the product of this residual bandwidth and constant C is computed (S81). When the value obtained by multiplying the residual bandwidth by the constant C is greater than the unit increase in cell rate (S82), switch 20 notifies source-side terminals 50-1, 50-2 and 50-3 that there is no congestion (S83), whereupon these source-side terminals increase their cell rate by the unit increase. According to this second embodiment of the invention, rather than increasing the cell rate gradually while observing the state of the entire route, a unit increase is set in advance and the cell rate is increased in one pass by that unit increase, by a decision of switch 20 alone. As a result, the cell rate of source-side terminals 50-1, 50-2 and 50-3 can be increased rapidly in stepwise fashion.
(Third embodiment)
A third embodiment of this invention will be explained with reference to FIG. 9-FIG. 14. FIG. 9, shows the essential parts of an ATM network according to this third embodiment, wherein source-side terminals 50-1 to 50-4 are source-side terminals which make calls in accordance with the ABR protocol; block 20 is a switch which emulates the ABR protocol for each terminal; and block 5 is part of a route shared by the terminals. In FIG. 10, which represents the bandwidth utilized by each terminal at a given time, Wa represents the residual bandwidth of the route in question, and W1, W2, W3 and W4 represent respectively the bandwidths utilized by source-side terminals 50-1 to 50-4. In FIG. 10, there is a large spread in the bandwidths being used, with the result that there is a possibility of unfair cell rates in the various terminals. FIG. 11 represents the relation between thresholds Rth1 and Rth2 in this third embodiment of the invention, and the peak cell rate (PCR) and minimum cell rate (MCR) of source-side terminals 50-1 to 50-4, for the same situation as in FIG. 10. FIG. 12 represents the relation between residual bandwidth and thresholds Wth1, Wth2 and Wth3 in this third embodiment of the invention.
The control algorithm in this third embodiment of the invention will be explained with reference to FIG. 13 and FIG. 14. FIG. 13 is a flowchart of the algorithm used by switch 20 for notifying terminals of congestion. FIG. 14 shows the relations among residual bandwidth, the cell rate of the terminals, and the contents of the corresponding congestion notification. Switch 20 monitors the residual bandwidth and compares its value with thresholds Wth1, Wth2 and Wth3. When residual bandwidth Wa is less than threshold Wth1 (S91), a congestion notification is sent to all source-side terminals 50-1 to 50-4 (S92). If the residual bandwidth Wa is equal to or greater than threshold Wth1 but smaller than threshold Wth2 (S93), a congestion notification is sent to any terminal at which the cell rate is equal to or greater than threshold Rth1 (S94). If the residual bandwidth Wa is equal to or greater than Wth2 but smaller than threshold Wth3 (S95), a "no congestion" notification is sent to any terminal 50-1 to 50-4 at which the cell rate is equal to or less than Rth2 (S96). If the residual bandwidth Wa is equal to or greater than threshold Wth3 (S97), a "no congestion" notification is sent to all source-side terminals 50-1 to 50-4 (S98). Congestion information is sent to each source-side terminal 50-1 to 50-4 by generating RM cells on the basis of these comparison results along the lines shown in FIG. 14, and transmitting them to these terminals. In accordance with the ABR protocol, when source-side terminals 50-1 to 50-4 receive a "no congestion" notification, they get a chance to increase their cell rate. Conversely, when they receive notification that there is congestion, they decrease their cell rate.
In this third embodiment of the invention, the timing at which a congestion notification is sent to source-side terminals 50-1 to 50-4 varies in accordance with the cell rate prior to the change and the residual bandwidth. As a result, when there is spare bandwidth, this third embodiment has the following effects. Namely, all the terminals are shifted to higher cell rates; the spread in cell rates is reduced, thereby giving greater fairness among the terminals; and the cell rate of a terminal with a low cell rate is increased rapidly. Conversely, if the bandwidth begins to be insufficient, the effect is that the cell rate of terminals with a high rate is reduced. If the bandwidth becomes even more insufficient, the effect is that all the cell rates are shifted downwards. In all of these cases, the control function can be implemented without RM cells being sent back and forth between source and destination terminals.
(Fourth embodiment)
A fourth embodiment of this invention will be explained with reference to FIG. 15-FIG. 18. FIG. 15, shows the overall constitution of an ATM network according to this fourth embodiment, wherein blocks 50-1 to 50-4 are source-side terminals, block 20 is a switch serving these source-side terminals, block 30 is a transit switch, block 40 is a switch serving destination-side terminals, 5 is a transmission link, and 60-1 to 60-4 are destination-side terminals. The constitution of this fourth embodiment will be explained with reference to FIG. 15.
Source-side terminals 50-1 to 50-4 make calls on the basis of the ABR protocol. Switch 20 enables connections to be established by emulating the ABR protocol for source-side terminals 50-1 to 50-4. It is not essential for switches 30 and 40 and destination-side terminals 60-1 to 60-4 to operate on the basis of the ABR protocol. Periodically, or when there has been a state change, switches 30 and 40 notify source-side switch 20 of the number of cells stored in their respective buffers. Switch 20 then judges the current state of utilization on the basis of the notified queue lengths and the number of cells stored in its own buffer.
The diagram shown in FIG. 11 in connection with the third embodiment of this invention also represents the relations among peak cell rate (PCR), minimum cell rate (MCR), thresholds Rth1 and Rth2, and the cell rate of each terminal in this fourth embodiment of the invention. Rate 1 to Rate 4 in FIG. 11 are the respective cell rates of source-side terminals 50-1 to 50-4. There is a large spread in the cell rates shown in FIG. 11, with the result that there is a possibility of unfairness in the cell rates of source-side terminals 50-1 to 50-4. FIG. 16 represents the relation between residual bandwidth and thresholds Qth1, Qth2 and Qth3 in this fourth embodiment of the invention.
FIG. 17 is a flowchart of the algorithm used by switch 20 for controlling the cell rates of source-side terminals 50-1 to 50-4. In FIG. 17, Qu is the value of the largest of the buffer utilizations notified to switch 20. Switch 20 compares thresholds Qth1, Qth2 and Qth3 with Qu. If the largest buffer utilization Qu is equal to or greater than threshold Qth3 (S101), a congestion notification is sent to all source-side terminals 50-1 to 50-4 (S102). If the largest buffer utilization Qu is equal to or greater than threshold Qth2 but smaller than threshold Qth3 (S103), a congestion notification is sent to any of source-side terminals 50-1 to 50-4 with a cell rate equal to or greater than threshold Rth1 (S104). If the largest buffer utilization Qu is equal to or greater than threshold Qth1 but smaller than Qth2 (S105), a "no congestion" notification is sent to any of source-side terminals 50-1 to 50-4 where the cell rate does not exceed threshold Rth2 (S106). If the largest buffer utilization Qu is smaller than threshold Qth1 (S107), a "no congestion" notification is sent to all source-side terminals 50-1 to 50-4 (S108). FIG. 18 shows the relations among largest buffer utilization Qu, cell rate of source-side terminals 50-1 to 50-4, and the contents of the corresponding congestion notification. RM cells are generated on the basis of comparison results along the lines shown in FIG. 18, and congestion information is notified by transmitting these RM cells to source-side terminals 50-1 to 50-4. In accordance with the ABR protocol, when source-side terminals 50-1 to 50-4 receive a "no congestion" notification, they get a chance to increase their cell rate. Conversely, when they receive notification that there is congestion, they decrease their cell rate.
In this fourth embodiment of the invention, the timing at which a congestion notification is sent to source-side terminals 50-1 to 50-4 varies in accordance with the cell rate prior to the change and the shared buffer length. As a result, when there is spare bandwidth or spare buffer capacity, this fourth embodiment has the following effects. Namely, all the terminals are shifted to higher cell rates; the spread in cell rates is reduced, thereby providing greater fairness among source-side terminals 50-1 to 50-4; and especially, the cell rate of a terminal with a low cell rate is increased rapidly. Conversely, if the bandwidth or buffer length begins to be insufficient, the effect is that the cell rate of terminals with a high rate is reduced. If the bandwidth or buffer length becomes even more insufficient, the effect is that all the cell rates are shifted down-wards. In all of these cases, the control function can be implemented without RM cells being sent back and forth between source and destination terminals.
(Fifth embodiment)
When another scheme is present in part of an ATM network, switches 30 and 40 and destination-side terminals 60-1 to 60-4 may sometimes transmit RM cells independently. In such a case, if "no congestion" has been entered in such an RM cell, then even though switch 20 may be acting to decrease the cell rate of source-side terminals 50-1 to 50-4, the opposite action to this will be requested by the returned RM cell. Accordingly, in this fifth embodiment of the invention, if an RM cell for source-side terminals 50-1 to 50-4 has arrived from elsewhere, it is discarded at switch 20. In this way, erroneous cell rate control resulting from RM cells with erroneous congestion information can be avoided.
(Sixth embodiment)
The constitution of a sixth embodiment of this invention will be explained with reference to FIG. 19, which shows the overall constitution of this sixth embodiment. Here, the explanation will focus on connections 70-1 to 70-3 between terminals 50-1 to 50-3 and terminals 60-1 to 60-3, the connections all sharing transmission link 5. In other words, terminals 50-1 and 60-1, terminals 50-2 and 60-2, and terminals 50-3 and 60-3 are respectively connected to each other by connections 70-1 to 70-3, said connections passing through switches 20-40 which are connected to each other via transmission links 5. Said terminals send and receive information at variable cell rates. Switches 20-40 each comprise: switching part 301 which performs circuit switching; control part 302 which as well as controlling this switching part 301, sends information relating to acceptable cell rates to source-side terminals 50-1 to 50-3 of connections 70-1 to 70-3 served by the control part, and collects the following information: the allowed cell rate and actual cell rate of connections 70-1 to 70-3, the total bandwidth and the total input bandwidth of shared transmission link 5, and the number of connections that share this transmission link 5; memory part 303 for holding the information collected by control part 302; and computing part 304 which, on the basis of the information held in memory part 303, calculates for each connection the acceptable cell rate for notification to source-side terminals 50-1 to 50-3.
In this constitution, source-side terminals 50-1 to 50-3 generate management cells at fixed cell number intervals, and transmit these management cells to destination-side terminals 60-1 to 60-3. The management cells have a CCR field for giving notification of the allowed cell rate of connections 70-1 to 70-3, and an ER field for giving notification of the acceptable cell rate. When a source-side terminal 50-1 to 50-3 transmits a management cell, its writes the current allowed cell rate ACR j (j=1, 2, . . . , n) of a connection 70-1 to 70-3 in the CCR field.
Each control part 302 of switches 20-40 measures the number of connections n which pass through the switch, the total bandwidth B all and the total input bandwidth B use of the output link, and the current cell rate ratej of each connection (j=1, 2, . . . , n), and holds this information in memory part 303 of the switch. Control part 302 of switches 20-40 also reads the allowed cell rate information for each connection, this information having been written in the CCR field of the management cell that passes through the switch, and holds this information in memory part 303 of the switch as ccr j (j=1, 2, . . . , n).
FIG. 20 shows the control flow of the switches, illustrating the calculation of the acceptable cell rate. Here, by way of example, an explanation will be given of switch 30. For each connections (j=1, 2, . . . , n), the maximum and minimum values that can be taken by the allowed cell rate are determined at call connection by negotiation with the network. This maximum value will be written as PCR j (peak cell rate), and the minimum value will be written as MCR j (minimum cell rate).
Switch 30 holds the following data in memory part 303: the number of connections n, the total bandwidth B all , the total input bandwidth B use , the current cell rate rate j , and the allowed cell rate ccr j (j=1, 2, . . . , n).
As shown in FIG. 20, for each connection 70-1 to 70-3 switch 30 compares the allowed cell rate and the actual cell rate, i.e. it compares ccr 1 and rate 1 , ccr 2 and rate 2 , ccr 3 and rate 3 . If an actual cell rate rate j is greater than a fixed proportion of the allowed cell rate, i.e. if rate j >ccr j ·G (where G is a constant such that 0<G≦1) (S111), then the requested cell rate r j (j=1, 2, . . . , n) for that connection j is taken as the PCR j (S113). Conversely, if an actual cell rate rate j is less than a fixed proportion of the allowed cell rate, then the cell rate requested for that connection is taken as the MCR j (S112). An updating equation for ERQ j can be determined by taking the variance of the ratio of allowed cell rate to requested rate for connections 70-1 to 70-3 as an evaluative function, said variance being given by: ##EQU4## Computing part 304 then obtains the acceptable cell rate ERQ j at switch 30 for connection j (j=1, 2, . . . , n) by computing the following (S114):
ERQ.sub.j =ccr.sub.j -α.sub.j ·sign{n·ccr.sub.j /r.sub.j -w·Σ.sub.i ccr.sub.i /r.sub.i }
where Σ i and Σ j are respectively the sums from i=1 to n and from j=1 to n, ccr j and r j are respectively the allowed cell rate and the requested cell rate of connection j, n is the number of connections 70-1 to 70-3 which are transmitting data, α j and w are weighting functions, and sign{ } is a function that expresses the sign of the value inside the curly brackets.
α j is a positive constant which differs for each connection 70-1 to 70-3. w is a decreasing function of the total input bandwidth of the transmission link shared by connections 70-1 to 70-3. For example, w may be taken as a function of the total bandwidth B all and the total input bandwidth B use of the transmission link shared by connections 70-1 to 70-3, namely:
w=(B.sub.all +p.sub.1)/(B.sub.use +p.sub.2)×p.sub.3
where p 2 is a constant for preventing the denominator from becoming zero, p 1 is a constant for correcting p 2 , and p 3 is a constant for setting the allowable width.
A value equal to the absolute value of:
{n·ccr.sub.j /r.sub.j -w·Σ.sub.i ccr.sub.i /r.sub.i }
may be set as α j . w can also be taken as the following function of the total input bandwidth B use of transmission link 5 shared by the connections:
w=-p.sub.4 ·B.sub.use +p.sub.5
where p 4 is a positive constant for setting the allowable width and p 5 is a correction constant.
When the newly calculated acceptable cell rate is smaller than the acceptable cell rate written in the ER field of a management cell returned by a destination terminal 60-1, 60-2 or 60-3, switch 30 rewrites the ER field to the newly calculated value. If the newly calculated acceptable cell rate is not smaller than the acceptable cell rate written in the ER field of the returned management cell, switch 30 does not rewrite. In either case, switch 30 relays the management cell and thereby notifies a source-side terminal 50-1 to 50-3. It is assumed that when a source-side terminal of connection j generates a management cell, it is the PCR j of connection j that is written in the ER field.
(Seventh embodiment)
A seventh embodiment of this invention will be explained with reference to FIG. 21, which shows the overall constitution of this embodiment. In this seventh embodiment, only switch 20 performs the calculation of the acceptable cell rate. This constitution comprises: switches 20-40 which are mutually connected via transmission links 5; and terminals 50-1 to 50-3 and 60-1 to 60-3 which are mutually connected by connections 70-1 to 70-3, which pass through these switches 20-40. The terminals send and receive information at variable cell rates. Switch 20 directly serves terminals 50-1 to 50-3 has control part 302 which, when terminals 50-1 to 50-3 served by switch 20 act as sources, sends to these terminals 50-1 to 50-3 and information relating to acceptable cell rates. Switch 20 also has memory part 303 and calculating part 304. Memory part 303 collects and holds the following information relating to the plurality of connections which share the route, i.e. relating to connections 70-1 to 70-3 for which terminals 50-1 to 50-3 constitute sources. Namely, memory part 303 collects and holds the allowed cell rate and the actual cell rate of each connection, the allowed bandwidth and the total input bandwidth of the route, and the number of connections that share this route. Computing part 304 calculates, for each connection and on the basis of the information held in this memory part 303, the acceptable cell rate to be notified to a terminal.
In other words, switch 20 rewrites management cells that have arrived from terminals 50-1 to 50-3 with acceptable cell rates which have been newly calculated by the switch, and returns the management cells to their originating terminals 50-1 to 50-3. In this way, source-side terminals 50-1 to 50-3 are notified of acceptable cell rates.
In the sixth and seventh embodiments of this invention, terminals 50-1 to 50-3 were notified of the acceptable cell rate. However, it is also possible for said terminals to be notified of information indicating a rise or fall in the allowed cell rate, and for these terminals to increase or decrease their own allowed cell rates in accordance with a predefined calculation formula. For example, when the acceptable cell rate newly calculated at the switch has become smaller than the current allowed cell rate used for the calculation, the fact that there is congestion is written in a management cell that has been returned by the destination-side terminal, and this is used to notify the source-side terminal. The allowed cell rate should be automatically decreased at the source-side terminal when a congestion notification is received.
(Eighth embodiment)
The constitution of an eighth embodiment of this invention will be explained with reference to FIG. 22-FIG. 24. FIG. 22 shows the overall constitution of an ATM network according to this eighth embodiment. FIG. 23 is a block diagram of a dynamic rate control system according to this eighth embodiment, and FIG. 24 shows the essential parts of this eighth embodiment.
The eighth embodiment of this invention is provided in an ATM network in the manner shown in FIG. 22. As illustrated in FIG. 23, the eight embodiment is a dynamic rate control system comprising: input terminal IN at which a cell stream arrives; cell buffer CB which temporarily stores cells which have arrived; and traffic shaper TS which reads cells from this cell buffer CB in accordance with the indicated cell transmission interval.
As shown in FIG. 24, the eight embodiment includes connection table CT the addresses of which are connection identifiers (VPI/VCI) and which holds connection information that includes the aforesaid cell transmission interval Int. Cell buffer CB includes a plurality of memory regions Cell each accommodating a single cell, and pointer regions Ptr which show pointers that map these memory regions Cell and the connection table CT.
This eighth embodiment of the invention comprises shared cell buffer CB which stores cells from all the connections, and connection table CT which holds, for each connection stored in cell buffer CB, the cell transmission interval Int and the head and tail addresses of the chain of cells in cell buffer CB in their arrival order. Cells of each connection are read from cell buffer CB in accordance with a prescribed scheduling rule.
Connection table CT is a table which holds information relating to each connection. This connection table holds, for each connection, a token Tk, a cell transmission interval Int, a head pointer, and a tail pointer. A token Tk indicates that the cell that arrives next on the connection in question has the right to be transferred when it arrives. A cell transmission interval Int indicates the minimum cell transmission interval which the connection in question has to maintain. The head pointer and the tail pointer indicate linking relations to the cell buffer CB (see arrows (1) and (2) in FIG. 24), and respectively hold the address at which the head cell of the connection in question is held (arrow (1)) and at which the tail cell of that connection is held (arrow (2)).
When a cell from a given connection is written in cell buffer CB, the cell is written in a free region of cell buffer CB. An example of this writing operation is given in FIG. 25, which shows how cells are written to cell buffer CB. FIG. 25 shows a chain of free memory regions in the cell buffer. The address of the head of the chain of free memory regions is assigned to an arriving cell by changing the CB free pointer. In FIG. 25, a cell which has arrived has simply been written in cell buffer CB, and it is still necessary to establish the correspondence between that cell and a connection. The list for the connection in question is therefore rearranged. This process of rearranging the list for the connection is illustrated in FIG. 26 and FIG. 27. In FIG. 26, an address for a cell that has arrived is added to the tail of the chain of cells of the connection in question in cell buffer CB. If there is no chain in the cell buffer, a new chain is created as shown in FIG. 27.
FIG. 28 shows how a cell of a given connection is fetched from cell buffer CB. In FIG. 28, the cell at the head of the cell chain of the connection in question in cell buffer CB is fetched and its head pointer changed.
Cell buffer CB is thus a shared buffer for cells from all connections and logically constitutes a FIFO queue for each connection. In FIG. 24, the CB free pointer holds the addresses of the head (arrow (3)) and the tail (arrow (4)) of a free region in cell buffer CB. Cell buffer CB and the CB free pointer are used in combination. One entry in cell buffer CB comprises a memory region Cell which holds the contents of a cell, and a pointer field Ptr for indicating the reading order of that cell within its connection. In cell buffer CB, lists of cells for each connection are formed logically in terms of the reading order relation shown by the pointers. In other words, for a particular connection, the cells of that connection can be accessed in their reading order by addressing cell buffer CB at the address shown by the head pointer of that connection in connection table CT (see arrow (1)), and then successively running through the list always using the address shown by the pointer at the previous address in cell buffer CB (see arrows (5) and (6)). Connection table CT holds, as linking information in the tail pointer, the address of the tail of the list in cell buffer CB for that connection (arrow (2)). Just as for each connection, free regions are formed logically into a list. The addresses of the head and tail of free regions in cell buffer CB are held respectively in the head pointer (arrow (3)) and the tail pointer (arrow (4)) of the CB free pointer. In other words, the head pointer shows the address to be used next as a free region (arrow (3)) and the address to be used as the next free region after that is given in the pointer of that address in cell buffer CB. The CB free pointer holds in its tail pointer, as linking information, the address of the tail of the list of free regions which are held in cell buffer CB (arrow (4)).
(Ninth embodiment)
A ninth embodiment of this invention will be explained with reference to FIG. 29, which shows the essential parts of the ninth embodiment. This ninth embodiment of the invention comprises, in addition to the constitution of the eighth embodiment, scheduling table ST which holds the mapping between times and connections, and timer Tim, which is a timer that shows the current time. A cell of the connection noted in scheduling table ST is read at the time shown by timer Tim. At the same time as this cell is read, the time at which the next cell of that connection is to be read is scheduled. Namely, the connection in question is written as an entry in scheduling table ST corresponding to a time later than the current time shown by timer Tim by the cell interval of that connection (this cell interval being noted in the cell transmission interval Int field of connection table CT).
(Tenth embodiment)
A tenth embodiment of this invention will be explained with reference to FIG. 30, which shows the essential parts of said tenth embodiment. In this tenth embodiment of the invention the scheduling table ST according to the ninth embodiment has a plurality of fields so that a plurality of connections can be assigned to the scheduling table simultaneously. This tenth embodiment also has, in addition to timer Tim which shows the current time, a virtual timer HTim which shows a virtual time.
In the ninth embodiment of this invention only one of the connections scheduled for the same time can actually be scheduled, whereas in this tenth embodiment a plurality of connections can be scheduled for the same time.
The value given by virtual timer HTim is used to indicate a prescribed address in scheduling table ST. Whereas timer Tim always shows the current time accurately, virtual timer HTim keeps showing the same time while scheduling table ST is reading from cell buffer CB the plurality of cells that have been scheduled to be read at the same time.
(Eleventh embodiment)
An eleventh embodiment of this invention will be explained with reference to FIG. 31, which shows the essential parts of said eleventh embodiment. The eleventh embodiment of the invention comprises: connection table CT, cell buffer CB, a CB free pointer which holds the head address and the tail address of the list of free addresses in cell buffer CB, scheduling table ST, timer Tim which shows the current time, virtual timer HTim which shows the virtual time, simultaneous arrival connection list SL, and an SL free pointer which holds the head address and the tail address of the list of free addresses in simultaneous arrival connection list SL.
Scheduling table ST is a table which schedules the reading of cells. It achieves its management function by pairing times with head and tail pointers which point to the simultaneous arrival connection list SL. This simultaneous arrival connection list SL is a list which holds the identifiers of connections that are scheduled to be read from cell buffer CB at the same time. The head pointer and the tail pointer of scheduling table ST show the linking relation to simultaneous arrival connection list SL (see arrows (20) and (21) in FIG. 31) and respectively hold the identifier of a head cell and a tail cell to be read from cell buffer CB at that time.
This eleventh embodiment has, in addition to timer Tim which shows the current time, a virtual timer HTim which shows a virtual time. The value given by virtual timer HTim is used to indicate a prescribed address in scheduling table ST.
Whereas timer Tim always shows the current time accurately, virtual timer HTim keeps showing the same time while simultaneous arrival connection list SL is reading from cell buffer CB the plurality of cells that have been scheduled to be read at the same time.
Simultaneous arrival connection list SL forms a chain of the connections that are scheduled to be read from cell buffer CB at the same time, and this enables the number of connections scheduled for the same time to be increased flexibly. The chain is formed by the same method used to form the FIFO queue of each connection in shared cell buffer CB. Namely, an SL free pointer holds the head and tail addresses of a free region of simultaneous arrival connection list SL. Simultaneous arrival connection list SL and the SL free pointer are used in combination. Simultaneous arrival connection list SL is a list which holds connection identifiers of cells, and each entry in this list comprises a connection identifier and a pointer for indicating the order in which that connection identifier is to be read (see arrows (22) and (23) in FIG. 31). In simultaneous arrival connection list SL, lists of connection identifiers of cells that have been scheduled to be read at the same time are formed logically in terms of the reading order relation indicated by the pointers. In other words, to take a particular time as an example, the connection identifiers of cells scheduled to be read at that time can be accessed in their reading order by addressing simultaneous arrival connection list SL at the address shown by the head pointer of virtual timer HTim (see arrow (20) in FIG. 31), and then successively running through the list always using the address given by the pointer at the previous address in simultaneous arrival connection list SL (see arrows (22) and (23) in FIG. 31). Virtual timer HTim holds in its tail pointer, as linking information, the address of the tail of the list in simultaneous arrival connection list SL for that time (see arrow (21) in FIG. 31). Just as for the various times, free regions are formed logically into a list. The addresses of the head and tail of free regions in simultaneous arrival connection list SL are held respectively in the head pointer (see (24) in FIG. 31) and the tail pointer (see (25) in FIG. 31) of the SL free pointer. In other words, the head pointer gives the address to be used next as a free region, and the address to be used as the next free region after this is given in the pointer with that address in simultaneous arrival connection list SL. The SL free pointer holds in its tail pointer (see (25) in FIG. 31), as linking information, the address of the tail of the list of free regions held in simultaneous arrival connection list SL.
FIG. 32 and FIG. 33 show how the connection identifiers of cells scheduled for a certain time are written in the simultaneous arrival connection list SL. FIG. 32 shows both the case where a newly scheduled connection is put at the head of a chain, and the case where it is put at the tail of the chain. As shown in FIG. 33, when there is no chain in the simultaneous arrival connection list SL, a new chain is created.
FIG. 34 shows how a connection identifier scheduled for a certain time is fetched from the simultaneous arrival connection list SL. In FIG. 34, the connection identifier is shown being fetched from the head of the chain.
In the foregoing explanation, the position at which a connection identifier is inserted was the tail pointer of the list of connection identifiers scheduled for the same time, and the position at which a connection identifier is read was the head pointer of the list of connection identifiers scheduled for the same time. In other words, connection identifiers scheduled for the same time are read in FIFO order. Moreover, connection identifiers scheduled for the same time are inserted further back in the list the shorter their cell interval, and therefore the shorter the cell interval. In otherwords the faster the cell rate, the later the scheduling. If the position at which a connection identifier is inserted is the head pointer of the list of connection identifiers scheduled for the same time, then connection identifiers scheduled for the same time will be read in LIFO order. The result of this is that the faster the cell rate of the connection, the sooner the connection identifier will be read. Furthermore, by deciding for each connection whether the position at which the connection identifier is inserted is the tail pointer or the head pointer of the list of connection identifiers scheduled for the same time, the connections can be divided into two classes. In other words, it will be possible to create two classes of connections scheduled for the same time: those that are scheduled sooner, and those that are scheduled later.
In the foregoing, the function of each block was described separately. An explanation will now be given of how the blocks interact to achieve the desired object. The relevant flow is shown in FIG. 35, which is a flowchart showing the operation of this eleventh embodiment of the invention. Processing is carried out in the following order: deciding the connection from which a cell is to be read (S121), reading a cell from that connection (S122), scheduling the reading of the next cell of that connection (S123), and writing a cell that has arrived to the FIFO queue in cell buffer CB (S124).
The processing required when a cell arrives is (a) the writing of that cell to cell buffer CB, and (b) the decision as regards whether or not that cell is scheduled for transfer. The processing involved in writing the cell to cell buffer CB differs according to whether or not there is already a list in cell buffer CB for the connection to which that cell belongs. If there is no such list, a list for that connection is first of all newly created in cell buffer CB. The cell is then written to a free region of cell buffer CB. This procedure has already been described in detail with reference to FIG. 25. Next, the logical relations in the list for that connection are newly created in cell buffer CB. This procedure has already been described in detail with reference to FIG. 26 and FIG. 27.
If there is already a list for that connection in cell buffer CB, the list is changed by carrying out the following processing. First of all, the cell is written to a free region of cell buffer CB. This procedure has already been described in detail with reference to FIG. 25. Next, the logical relations in the list for that connection are changed. This procedure has already been described in detail with reference to FIG. 26 and FIG. 27.
Whether or not a cell is scheduled for transfer is determined by whether or not the connection to which that cell belongs has a token Tk. When a cell arrives, connection table CT is looked up on the basis of the connection identifier carried in the cell header.
If no token Tk has been set, transfer scheduling of that cell is not carried out at that point in time. Instead, it is scheduled when the tail cell of that connection at that time is transferred. This will be explained detail in the subsequent section on the processing involved in reading cells.
If token Tk has been set, the scheduling table is looked up, with addressing being carried out by timer Tim which shows the current time. Subsequent processing varies according to whether or not there is a connection which has already been scheduled for that time.
If there is no previously scheduled connection, processing is performed as follows. Namely, lists of cells to be transferred at the current time shown by timer Tim are newly created in simultaneous arrival connection list SL. Firstly, the connection identifier in question is written in a free region of simultaneous arrival connection list SL. Next, the logical relations of the lists of cells to be transferred at the current time shown by timer Tim are newly created in simultaneous arrival connection list SL. These procedures have already been described in detail with reference to FIG. 32 and FIG. 33.
If there is previously scheduled connection, processing is performed as follows. Namely, the lists of cells to be transferred at the current time shown by timer Tim are changed in simultaneous arrival connection list SL. Firstly, the connection identifier in question is written in a free region of simultaneous arrival connection list SL. Next, the logical relations of the lists of cells to be transferred at the current time shown by timer Tim are changed in simultaneous arrival connection list SL. These procedures have already been described in detail with reference to FIG. 32 and FIG. 33.
As has been explained in the foregoing, if a token Tk has been set, the cell in question is scheduled for the current time shown by timer Tim. However, it will sometimes be desired to transfer the cell in question when the virtual time shown by virtual timer HTim has lagged behind during the processing of scheduling table ST. In this case, scheduling table ST is addressed at the time shown by virtual timer HTim, and the connection identifier of the cell in question is added to the head of the list indicated by the head pointer with this address.
The processing required when a cell is read is (a) determining the connection from which a cell is to be read, (b) reading the cell, and (c) scheduling the next cell. Determining the connection differs according to whether or not there is a cell to be transferred at the virtual time shown by virtual timer HTim. If there is no cell to transfer, virtual timer HTim is advanced one unit of time, and each time it does so a check is made to see whether or not there is a cell to be transferred at that time. Virtual timer HTim is advanced faster than the usual rate until a cell for transfer is found. If no cell has been found after the time has been advanced by a prescribed amount, the reading of cells is abandoned. To perform this processing more efficiently, the concept of a list may be introduced for scheduling table ST as well. This will be explained in a section dealing with the processing that is performed within one unit of time. When a cell to be transferred has been found within the prescribed time, the subsequent processing is the same as when there is a cell to be transferred.
If there is a cell to be transferred, the connection to be read at this time is determined. That is to say, the connection identifier scheduled for this time is fetched from simultaneous arrival connection list SL. This procedure has already been described in detail with reference to FIG. 34.
Next, a cell of that connection is read from cell buffer CB. The processing involved in reading a cell from cell buffer CB differs according to whether or not there is a cell of that connection in cell buffer CB. Connection table CT is accessed on the basis of the previously determined connection identifier.
If there is no cell of that connection in cell buffer CB, a token Tk is simply set in connection table CT, and no cell is read from cell buffer CB.
If there is a cell of that connection in cell buffer CB, the cell is fetched. This processing has already been described in detail in the section dealing with cell buffer CB.
The processing involved in scheduling the next cell differs according to whether or not a token Tk has been set for the connection in question. Connection table CT is accessed on the basis of the previously determined connection identifier.
If a token Tk has been set in connection table CT, the scheduling of that connection is carried out when a cell of that connection next arrives. This has been described in detail in the section dealing with the cell arrival processing.
If a token Tk has not been set in connection table CT, the minimum cell interval Int of that connection, said cell interval being given in connection table CT, is added to the current time being counted by timer Tim, the result taken as the transfer time of the next cell, and the connection in question scheduled on this basis. In other words, scheduling table ST is addressed at Int+Tim, and the connection identifier in question is appended to the list of connection identifiers in simultaneous arrival connection list SL that have been scheduled for time Int+Tim, this list being indicated by the head pointer of scheduling table ST. The processing involved in appending a connection identifier has previously been described in detail in the section where the simultaneous arrival connection list SL was explained, and therefore no further details will be given here. It should be noted that because the cell transfer scheduling uses timer Tim which shows the current time, rather than virtual timer HTim, the cell transmission interval Int of the connection in question strictly speaking does not become smaller than the prescribed cell transmission interval Int. If fluctuation of cells scheduled for the same time is allowed, the connection in question can be transferred sooner if it is scheduled for time Int+HTim. The processing involved in making an entry in scheduling table ST is approximately the same as when no token Tk has been set (see the section on cell arrival processing).
(Twelfth embodiment)
A twelfth embodiment of this invention will be explained with reference to FIG. 36, which shows the essential parts of the embodiment. One unit of time is the time required to transfer a cell onto an output line. Cell arrival processing and cell reading processing are carried out in that order in one unit of time. This twelfth embodiment of the invention is designed to make virtual timer HTim, which shows the address in scheduling table ST that is to be processed, catch up efficiently with timer Tim which shows the current time. As mentioned previously, whereas timer Tim always shows the current time accurately, virtual timer HTim keeps showing the same time while simultaneous arrival connection list SL is reading from cell buffer CB the plurality of cells that have been scheduled to be read at the same time. When a large number of connections are scheduled for the same time, there will be a large time difference between virtual timer HTim and timer Tim, and it will take time to catch up with timer Tim after the processing involved in reading cells scheduled for the time shown by virtual timer HTim has been completed.
Accordingly, in this twelfth embodiment of the invention, in order to catch up efficiently with timer Tim, a pointer field is introduced in each time entry in scheduling table ST and a list of the times at which cells should be output is constructed.
In FIG. 36, a list of times at which cells should be output is formed in scheduling table ST. The head of the list is the address shown by virtual timer HTim, while the tail of the list is the address shown by tracking timer TTim. This list of times at which cells should be output is formed logically by the relations indicated by the pointers. In other words, the times at which cells are to be read out can be successively accessed by addressing scheduling table ST at the address shown by virtual timer HTim, and then successively running through the list always using the address shown by the pointer at the previous address.
Initially, virtual timer HTim, tracking timer TTim and timer Tim all show the same time, but if at a certain time there are a plurality of cells scheduled for the same time, then virtual timer HTim will lag behind and timer Tim will be relatively ahead. If virtual timer HTim and timer Tim are not synchronized but no new cells arrive and timer Tim does not show a time at which a cell has been scheduled, then while this is the case, tracking timer TTim will show the same time as virtual timer HTim.
When a cell newly arrives, the address shown by timer Tim is written in the pointer of the address in scheduling table ST shown by tracking timer TTim, so that this address is shown by tracking timer TTim as well. The same processing is also performed when timer Tim has indicated a time at which a cell is scheduled, with the current time being added to the list of times at which cells are to be read.
(Thirteenth embodiment)
Next, a thirteenth embodiment of this invention will be explained with reference to FIG. 37, which shows the essential parts of said thirteenth embodiment. This thirteenth embodiment restricts the number of cells in cell buffer CB for each connection, thereby reducing the adverse effects that inter-connection competition for buffer space can have on quality. In this invention, because cell buffer CB is a shared buffer, if an excessive number of cells arrive from a specific connection they end up taldng possession of cell buffer CB, with the result that there is a danger that they will have an adverse effect on the quality of other connections. This thirteenth embodiment of the invention restricts the number of cells that can enter cell buffer CB from any one connection, so that a specific connection cannot take over possession of cell buffer CB in this way.
Before a cell is written to cell buffer CB, a comparison is made between the Q1en field and the B1en field in connection table CT. If the Q1en field is smaller, the cell is written to cell buffer CB and at the same time Q1en is incremented by 1. If the Q1en field is not smaller, writing of the cell to cell buffer CB is prohibited. In addition, when a cell is read from cell buffer CB, the value of the Q1en field is decremented by 1. The Q1en field shows the number of cells in cell buffer CB from a given connection, while the B1en field shows the number of cells which that connection is allowed to have in cell buffer CB.
(Fourteenth embodiment)
A fourteenth embodiment of this invention will be explained with reference to FIG. 38, which shows the essential parts of said embodiment. This fourteenth embodiment introduces the concept of priority into the connection scheduling. As described previously, connection identifiers scheduled for the same time are read in FIFO order. Moreover, if connection identifiers scheduled for the same time are inserted further back in the list, the shorter their cell transmission interval Int, and therefore the shorter the cell transmission interval Int. In other words, the faster the cell rate, the later the scheduling. If the position at which a connection identifier is inserted is the head pointer of the list of connection identifiers scheduled for the same time, then connection identifiers scheduled for the same time will be read in LIFO order. The result of this is that the faster the cell rate of the connection, the sooner the connection identifier will be read. Furthermore, by deciding for each connection whether the position at which the connection identifier is inserted is the tail pointer or the head pointer of the list of connection identifiers scheduled for the same time, the connections can be divided into two classes. In other words, it will be possible to create two classes of connections scheduled for the same time: those that are scheduled sooner, and those that are scheduled later.
A field Pri for expressing the priority ranking of each connection is provided in connection table CT. When an element is to be added to the list of connection identifiers scheduled for the same time in simultaneous arrival connection list SL, if connection table CT shows a high priority in field Pri corresponding to the connection identifier of this element, the new element is added at the position indicated by the head pointer of scheduling table ST, whereas if field Pri shows a low priority, the new element is added at the position indicated by the tail pointer of scheduling table ST.
In all the embodiments explained so far, connection identifiers were entered in simultaneous arrival connection list SL. However, as an alternative, it would also be feasible to enter connection table addresses.
(Fifteenth embodiment)
A fifteenth embodiment of this invention will be explained with reference to FIG. 39 and FIG. 40. FIG. 39 is a block diagram of a dynamic rate control system according to this fifteenth embodiment, while FIG. 40 is a flowchart showing the operation of this dynamic rate control system.
A dynamic rate control system according to this fifteenth embodiment of the invention comprises: cell flow measuring part 1 as means for measuring cell flow; congestion detector 2 as means for comparing this measured cell flow with a threshold; and congestion notification part 4 as means which, in accordance with the result of this comparison, sends regulation information that includes a cell flow regulation factor to the cell generator.
The dynamic rate control system according to this fifteenth embodiment of the invention includes congestion controller 3 as means which, when regulation is being applied to one cell generator, maintains this regulation until the measured cell flow from that cell generator reaches a preset value below the aforesaid threshold.
As shown in FIG. 40, the aforesaid regulation factor R is set to R=1/λ (S133) where λ is the normalized cell flow and the normalized threshold Λ is 1. The regulation factor R is set to R=1 (S135) when λ<1/R (S134).
In other words, a dynamic rate control system according to this fifteenth embodiment of the invention comprises cell buffer 15, cell flow measuring part 1, and congestion notification part 4 which consists of congestion detector 2 and congestion controller 3. This dynamic rate control system operates as follows. Namely, congestion is detected by congestion detector 2 in accordance with the cell flow obtained by cell flow measuring part 1; the start and cancellation of regulation is determined by congestion controller 3; and congestion notification part 4 informs cell-generating terminals of the regulation factor R using RM cells that flow in the opposite direction to the direction in which congestion is experienced.
FIG. 40 is a flowchart of the operation of congestion detector 2 and congestion controller 3. If there is no current congestion (S131), the measured cell flow λ obtained by cell flow measuring part 1 is compared with a cell flow threshold Λ used to detect congestion (S132). For this comparison, all quantities relating to cell flow are normalized by taking the transmission link capacity as 1. If cell flow λ has exceeded threshold Λ, it is judged that there is congestion, whereupon the regulation factor R applied to the cell output rate from a cell generator is set to 1/λ (S133). In other words, by regulating by 1/λ or less of the current cell rate of a cell generator, the cell flow from the cell generator is restricted to "1" or less, and the congestion is cleared.
If there is currently congestion (S131), the cell flow λ is compared with the reciprocal 1/R of the current regulation factor R (S134), and if cell flow λ is the smaller, it is decided that the congestion has cleared and the regulation is cancelled (S135). As a result of cancelling the regulation, the cell flow λ will increase R times. However, because the cell flow from the cell generator prior to cancellation of the regulation was 1/R or less, the cell flow from the cell generator will not exceed 1.
FIG. 41 and FIG. 42 show the operation of this fifteenth embodiment of the invention in terms of the relation between cell flow λ and time, with time taken along the horizontal axis and cell flow λ along the vertical axis. In the left-hand diagram of FIG. 41 the total of the cell rates from the cell generators has reached λ (where λ>Λ), with the result that a congested state has arisen. When this happens, the regulation factor R is set to 1/λ and notification of this is sent to the cell-generating terminals. If the cell rate from the cell generators effectively becomes 1/λ after the elapse of a prescribed time, then as shown in the right-hand diagram of FIG. 41, the congestion has cleared. If congestion is suppressed, retransmission from cell generators ceases and there is no shift to catastrophic congestion. However, because the cell rate of the cell generators is currently being regulated by 1/λ, immediate cancellation of the regulation means that R times the traffic is applied, with the result that congestion will occur again. Accordingly, as shown in the left-hand diagram of FIG. 42, the regulation is not cancelled until the cell rate from the cell generators has dropped to 1/R or less. By doing it this way, congestion will not occur again even if after the cancellation of regulation the traffic increases by a factor of R (see the right-hand diagram of FIG. 42).
(Sixteenth embodiment)
A sixteenth embodiment of this invention will be explained with reference to FIG. 43 and FIG. 44, which are block diagrams of a dynamic rate control system according to this sixteenth embodiment. The dynamic rate control system shown in FIG. 43 comprises: cell buffer 15, cell flow measuring part 1, congestion notification part 4 comprising congestion detector 2 and congestion controller 3, rate table 6, and multiplier 7. In rate table 6, the cell rate at which the cell generator transmits cells is entered for each connection. The operation of cell flow measuring part 1, congestion detector 2 and congestion controller 3 is similar to the fifteenth embodiment, but in this sixteenth embodiment of the invention, what is carried in an RM cell flowing in the opposite direction to the direction in which congestion has been detected, and is thereby notified to the cell-generating terminal, is not the regulation factor R, but instead the product of the regulation factor R and the cell rate, this product being obtained by multiplication by multiplier 7. The cell-generating terminal regulates its cell rate using the cell rate entered in that RM cell.
FIG. 44 shows an example in which rate table 6 and multiplier 7 are provided in switch 20. It is not necessary for rate table 6 to be provided in congestion controlling switch 30 which is the point at which congestion is detected. Instead, it may be located in subscriber switch 20 which serves terminals. In this case, the RM cells used for notifying that there is congestion carry the regulation factor R while being transferred through the network, and this regulation factor is converted to a cell rate for the transfer from switch 20 to a subscriber.
One advantage of this sixteenth embodiment of the invention is that a cell-generating terminal does not require means for converting the regulation factor R to a regulated cell rate.
(Seventeenth embodiment)
A dynamic rate control system according to a seventeenth embodiment of this invention will be explained with reference to FIG. 45, which is a block diagram of a dynamic rate control system according to this seventeenth embodiment. The dynamic rate control system shown in FIG. 45 comprises: cell buffer 15, cell flow measuring part 1, congestion detector 2, and congestion notification part 4 that includes congestion controller 3. Congestion detector 2 detects the build-up of cells in cell buffer 15, i.e. it detects congestion on the basis of queue length. When the queue length exceeds a queue length threshold for congestion detection, it is decided that there is congestion and regulation is started. The decision to cancel the regulation is made in the same way as in the fifteenth and sixteenth embodiments.
(Eighteenth embodiment)
A dynamic rate control system according to an eighteenth embodiment of this invention will be explained with reference to FIG. 46 and FIG. 47. FIG. 46 is a block diagram of the dynamic rate control system according to this eighteenth embodiment, while FIG. 47 is a flowchart showing the operation of the dynamic rate control system. The dynamic rate control system shown in FIG. 46 comprises: cell buffer 15, cell flow measuring part 1, congestion notifying part 4 comprising congestion detector 2 and congestion controller 3, and timer 8. In this eighteenth embodiment of the invention, it is decided that there is congestion when the congestion detection threshold has been exceeded continuously for more than a set time. In addition, if the congestion is not cleared after a set time has elapsed since the decision that there is congestion, the regulation is intensified.
A flowchart of the operation of congestion detector 2 and congestion controller 3 in this eighteenth embodiment of the invention is shown in FIG. 47. If there is no current congestion (S141), the measured cell flow λ obtained by cell flow measuring part 1 is compared with a congestion detection threshold Λ (S142). If cell flow λ has exceeded threshold Λ, it is judged that there is congestion, whereupon the regulation factor R applied to the cell output rate from a cell generator is set to 1/λ (S143). Even if the cell flow λ does not exceed the threshold Λ, if cell flow λ stays equal to or greater than 1 for more than a set time RTT (S144), it is judged that there is congestion and the regulation factor R to be applied to the cell rate is set to min(1/λ) (S145), where this minimum function ranges over the time period RTT. In other words, the regulation factor R is set to the reciprocal of the maximum cell flow λ max over the period RTT (i.e., to the minimum value min).
If there is currently congestion, the cell flow λ is compared with the reciprocal 1/R of the current regulation factor R (S146), and if the cell flow λ is the smaller, it is decided that the congestion has cleared and the regulation is cancelled (S147). If the cell flow λ is not smaller than 1/R, and the congestion has continued for more than a set time RTT (S148), it is judged that there is severe congestion and the regulation factor R to be applied to the cell rate is intensified to min(R/λ) (S149), where this minimum function ranges over the time period RTT.
(Nineteenth embodiment)
A dynamic rate control system according to a nineteenth embodiment of this invention will be explained with reference to FIG. 48 and FIG. 49. FIG. 48 serves to explain the dynamic rate control system according to this nineteenth embodiment, while FIG. 49 is a flowchart showing its operation. If the regulation factor R is large, then after congestion has cleared, the network utilization efficiency will decrease until the regulation is cancelled. Accordingly, in this nineteenth embodiment of the invention the cancellation of the regulation is carried out in steps. As shown in FIG. 48 and FIG. 49, the number of cells in each set time period RTT is observed (S151), and if there is a state of congestion at time (a) when a cell rate of λ0 is observed (S152), the cell rate of the cell generator is regulated (S153), with the regulation factor at the start of the congestion control being set to R=1/λ0 (λ0>1) (S154), where λ0 is the cell flow from the cell generator. If, at time (b) when a cell rate of λ1 is observed, the congestion has still not cleared (S152) after a set time has elapsed (S151) despite regulation having started (S153), the regulation factor is intensified by setting a next regulation factor R'=R/λ1 (λ1>λ0>1) (S155), where λ1 is the cell flow from the cell generator and has a value of equal to or greater than 1. If the congestion has cleared at time (c) when a cell rate of λ2 is observed (S152, S156), the regulation factor is successively relaxed. That is, the regulation factor is relaxed within a range such that congestion will not re-occur, and is set to R"=R/λ2 (λ2<1) (S157), where λ2 is the cell flow from the cell generator and has a value of less than 1. If the cell flow at time (d), when a cell rate of λ3 is observed, is smaller than the reciprocal 1/R of the regulation factor R (S158), the regulation is cancelled (S159). The foregoing procedure enables network utilization efficiency to be increased even while regulation is being applied.
(Twentieth embodiment)
A dynamic rate control system according to a twentieth embodiment of this invention will be explained with reference to FIG. 50 and FIG. 51. FIG. 50 is a flowchart showing the operation of a dynamic rate control system according to this twentieth embodiment, and FIG. 51 shows a call type management table.
A dynamic rate control system according to this twentieth embodiment of the invention is provided in switch 20 as shown in FIG. 2 which served to illustrate the first embodiment, and includes cell rate computation and control part 12. In a cell rate computation and control part 12 according to this twentieth embodiment, the plurality of connection requests is divided into i groups in accordance with the peak rate and the average rate. As shown in FIG. 50, for all this plurality of connection requests the cell loss ratio CLRI of the i th group is calculated as:
CLR.sub.i ≦(a.sub.all /c)·(r.sub.i /a.sub.i)·CLR.sub.AVE (Eq. 2)
where CLR AVE is the average cell loss ratio, a all is the sum of the average rates, c is the VP bandwidth, r i is the peak rate of group i, and a i is the average rate of group i. A group which satisfies this cell loss ratio CLR i is allowed to be connected.
In other words, as shown in FIG. 50, as a first step a connection for which there has been a connection request is provisionally entered in the call type management table (S161). As shown in FIG. 51, the call type management table has fields in which are recorded for each call type the number of connections, the peak rate, and the average rate. The peak rate and the average rate of a connection for which there has been a connection request are examined, and if a call type with the values is already entered in the call type management table, the relevant number of connections is incremented by 1. If there is no entry, the values are entered in the peak rate and average rate fields, the connection number field is set to "1", and the call type is added to the table.
Next, as the second step, the average cell loss ratio is calculated. f i (x), the cell rate probability density function for call type i, is calculated using the call type management table. This is given by: ##EQU5## where N i is the number of VCs of call type i and p i is the ratio of average cell rate to peak rate for call type i. f i (x) is convolved for all call types i to obtain the cell rate probability density function F(x) for all call types. Namely:
F(x)=f.sub.i * . . . *f.sub.n (x) (Eq.4)
where n is the number of call types and * is the convolution operator. The average cell loss ratio CLR AVE can then be expressed using F(x) as follows (S162): ##EQU6##
Next, as the third step, the cell loss ratio for each call type is calculated. The cell loss ratio CLR i for call type i can be obtained from Eq.2:
CLR.sub.i ≦(a.sub.all /c)·(r.sub.i /a.sub.i)·CLR.sub.AVE (Eq. 2)
where a all /c is a first safety factor which is common to all call types, and r i /a i is a second safety factor specific to call type i (S163).
Next, as the fourth step, it is decided whether or not the cell loss ratio CLR i for call type i is smaller than the standardised value for cell loss ratio, and if it is greater, the decision is made to reject the connection request and the decision flow is terminated (S164).
If it is smaller, processing advances to the next step. Here, by changing the standardized value of the cell loss ratio according to call type, it is possible to meet the requested quality for a plurality of call types.
Next, as the fifth step, it is decided for all call types whether or not the cell loss ratio has been compared with the standardised value, and if it is ascertained for all call types that the decision has been made that the standardized value is satisfied, the processing advances to the next step. If decisions have not been completed for all call types, the third and subsequent processing steps are repeated for the next call type (S165, S167). Finally, as the sixth step, if it has been ascertained in the fifth step that the standardized value of the cell loss ratio is satisfied all call types, the connection request that was provisionally entered in the call type management table in the first step is formally entered and the decision flow terminates (S166).
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In a best effort type service of an ATM communication network for circulating an RM cell, a subscriber's switchboard holds the latest route information, and the RM cell is used for short distance communication between the communication terminal and subscriber's switchboard. For a plurality of connections accommodated in the switchboard and using a transmission line or a route in common, information on the allowable transmission rate, the actual transmission rate, the full bandwidth and full input bandwidth of the transmission line or the route, and the number of connections using in common the transmission line are collected and held. A transmission rate acceptable for the caller's terminal is calculated for each connection on the basis of the information. An increase of a memory capacity is restricted by providing a common buffer and managing it by a pointer value. A list of cells which have arrived simultaneously is prepared, and is managed by the pointer value. The cells are sent out at different timings so as not to be discarded. Even when congestion is solved, the restriction is not quickly lifted but control is enforced in consideration of the increment of the cell flow rate immediately after the lift. Convolution calculation is made only once for determining the overall mean cell loss ratio and consequently the number of calculations is reduced.
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TECHNICAL FIELD
[0001] The invention relates to the field of lifting tackle and particularly to the field of crane technology in connection with the controlled guidance of equipments in three-dimensional spaces. The invention relates in particular to the guidance of a camera in a three-dimensional space by swiveling a crane jib with a camera attached to one of its ends.
PRIOR ART
[0002] An equipment crane of this kind is known from DE 298 16 565 U1, DE 299 07 704 U1 and DE 299 16 225 U1. With the camera crane described there, the camera may be guided in a three-dimensional space by the swiveling motion of a crane jib, whereby parallelogram guidance enables the camera-receiving plate to be held in a specific alignment including also horizontal alignment during guidance through the three-dimensional space. However, it is also possible to change the rope guidance used in the parallelogram system so that there is no longer any parallelogram setting. The camera-receiving plate may be preadjusted in one direction or the other in relation to the setting angle.
DESCRIPTION
[0003] The technical problem (object) of the invention is to define precisely in an equipment crane, particularly a camera crane of the type described at the start, the guidance of an equipment or a camera in the three-dimensional space.
[0004] This object is achieved by an equipment crane, particularly a camera crane, comprising a crane support and crane jib pivotably mounted thereon at a first articulation point. At one end of the crane jib an equipment receiving element is articulated to a second articulation point, to which a traction element is articulated at a third articulation point, which is at a distance from the second articulation point, the said articulation point being guided from there to the crane support, and where it is articulated to a fourth articulation point, which is at a distance from the first articulation point. In the swiveling range of the equipment receiving element and in the area of the second articulation point, there is a motion damping equipment by means of which the swiveling motion of the equipment receiving element may be damped.
[0005] The solution prevents, particularly in the case of a long crane jib and hence a long traction element, any length changes to the traction element caused by loading by a heavy equipment causing it to undergo unwanted oscillations. Even if a pre-stretched traction rope is used, it is not really possible to avoid length changes under relatively high loads in a crane of this type. In addition, the use of a non-extending traction rope results in a not insignificant cost. This can be avoided according to the invention because the extensions of the traction element or the traction rope are isolated by the damping equipment and so the equipment may be guided through the three-dimensional space exclusively with the desired movement.
[0006] Preferably, there are several damping elements that may be switched on or off selectively depending on the weight of the equipment. This enables the degree of the damping to be adapted to the camera weight in question and to the oscillation intensity, which is dependent upon the expansion of the traction element per se and the expansion in dependence on the length of the traction element. The motion damping equipment may be damped.
[0007] In order to achieve the damping effect in a simple way, the use of damping elements that are known per se is envisaged comprising an inner disk and an outer disk, with said inner disk being able to turn inside the outer disk with an interposed viscous fluid. The inner disk is firmly seated on an axis that turns with the equipment receiving element. The outer disk may be locked on the jib side. When the outer disk is locked, the damping disk functions as a damping element. If this locking is not applied, the inner disk and outer disk turn together without any damping action.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The drawings are a purely schematic representation of an example of an embodiment.
[0009] FIG. 1 is a perspective view of a camera crane according to the invention FIG. 2 is a perspective view of the side of the crane support to which the traction rope is attached and
[0010] FIG. 3 is a perspective view of the other side of the crane support to which the end of the traction rope is attached.
[0011] FIG. 4 is a perspective representation of the end of the crane jib with the camera-receiving plate FIG. 5 is a schematic side view of the end of the crane jib shown in FIG. 4 , and
[0012] FIG. 6 is a section view along the line VI-VI in FIG. 5 .
DESCRIPTION OF AN EXAMPLE OF AN EMBODIMENT
[0013] A camera crane shown in FIG. 1 comprises a crane support 1 , only part of which is shown in FIG. 1 . The lower part of the crane support 1 is not shown here, but may take the form of a tripod. In addition, the camera crane comprises a crane jib 2 which is pivotably mounted on a first articulation point 3 on the crane support 1 . There is a counterweight 4 on the right-hand end of crane jib 2 in the drawing. A camera-receiving plate 6 designed as camera-holding element is pivotably mounted at the opposite end of the crane jib 2 at a second articulation point 5 . In the embodiment shown here (to which the invention is not restricted), a rope pulley 7 is pivotably mounted together with the camera-receiving plate 6 with its center in the area of the second articulation point 5 . Without implying any restriction to this example of an embodiment, a similar rope pulley 8 is located at the first articulation point 3 so that its center is arranged on this articulation point, which is simultaneously the swivel axis of the crane jib 2 . Between these pulleys 7 and 8 , a traction rope 9 runs in such way that a third articulation point 10 is formed on the tangential contact point of the traction rope 9 on the circumference of the rope pulleys 7 and 8 in the area of the camera-receiving plate 6 and a fourth articulation point 11 is formed in the area of the crane jib pivot mounting. If this traction rope 9 , which is simultaneously a control rope, runs parallel to the crane jib 2 , the crane jib together with the traction rope 9 and the articulation points 3 , 5 , 10 , 11 form a parallelogram system in such a way that when the crane jib 2 is swiveled, the camera-receiving plate 6 may be held in either an exactly horizontally aligned position or in a specific inclined position if the camera-receiving plate 6 is moved in the three-dimensional space by means of the crane jib 2 when it is swiveled in the crane support 1 .
[0014] The crane jib 2 may then have a relatively lightweight design if it is reinforced by rope struts 12 . In addition, the length of the crane jib 2 can be altered if, for example, the crane jib is telescopic or if the crane jib 12 comprises several sections that are inserted into each other so that it may be shortened or lengthened. Here, the rope struts 12 are slung on as appropriate and the course of the traction rope 9 is also suitably adapted, that is shortened or lengthened.
[0015] If a telescopic jib is involved in the crane jib length adjustment, this expression also covers the aforementioned plug-in connection.
[0016] The rope pulleys 7 and 8 do not have to, but can be, pivoted, whereby the rope pulley 8 is preferably pivoted about its axis. The rope pulley 7 may normally be pivoted with the camera-receiving plate 6 .
[0017] The crane support shown in isolation in FIG. 2 with no supporting structure only illustrates one part of the crane jib 2 . However, FIG. 2 shows individual details more clearly than FIG. 1 , particularly the rope pulley 8 with the first articulation point 3 , which is located in the swivel axis of the crane jib 2 and which stays with the axis of the rope pulley 8 when the parallelogram system is adjusted. Also clearly identifiable is the traction rope 9 , which emerges from the rope pulley 7 , not shown, runs partially about the rope pulley 8 and continues, whereby the end of the rope is attached to the crane support 1 . This may, in principle, be provided on the same side of the crane support. Here, the rope pulley 8 is located on one side of the crane support and the fixed end of the traction rope 9 is located at the other end of the crane support, whereby a major support 13 and a minor support 14 are provided. Although it is also possible to fix the rope end on the crane support 1 on the same side, that is, on the side of major part support 13 , this drawing shows a split solution in which the traction rope 9 is guided partially around the rope pulley 8 and from there guided partially around a deflection pulley 15 . The axis of rotation 16 of this deflection pulley 15 runs parallel to the axis of the rope pulley 8 . From the deflection pulley 15 , the traction rope 9 runs partially around a deflection pulley 17 whose axis rotates perpendicular to the axis 16 of the deflection pulley 15 . From there, the traction rope 9 runs from the major support 13 to the minor support 14 and in this is again guided around another deflection pulley 18 , which may also be seen in FIG. 3 . From there, the traction rope 9 runs to a suspension element 19 forming a latching point. This suspension element 19 is mounted displaceably in a recess 20 in the minor support 14 , and, to be precise, in the direction corresponding to the course of the traction rope 9 at this point. Here, this suspension element 19 takes the form of a spindle nut and sits on a spindle bolt 21 . If this spindle bolt 21 is turned by means of a rotary lever 22 , the position of the suspension element 19 relative to its position in the direction of the spindle bolt 21 may be changed. The consequence is that traction is applied to the traction rope 9 in the relevant direction. This in turn has the result that the angle of the camera-receiving plate 6 changes. This adjustment possibility may also be used to set the desired angle of the camera-receiving plate 6 . If parallelogram guidance is set by means of the traction rope 9 and the crane jib 2 , this position may then be maintained in the event of the crane jib being swiveled. However, it is possible to dispense with this parallelogram guidance. To do this, a similar spindle-nut system with a spindle bolt 23 and a lever 24 may be used to change the position of the rope pulley 8 in the major support 13 and indeed in approximately the same direction as the adjustment of the suspension element 19 , which on the one hand permits the exact adjustment of the parallelogram system, but on the other hand an adjustment may be made in that the traction rope 9 leaves the parallelogram system to a greater or lesser extent. This adjustment results in a change to the angular position of the camera-receiving plate 6 and also the desired setting of the change to the angle of the camera-receiving plate during the swiveling of the crane jib.
[0018] The suspension of the end of the traction rope 9 in the suspension element 19 is achieved by a receiving or latching element 25 fixed to the traction rope, which is not identifiable in suspended condition but is implemented by a latching element 25 shown in the path of the traction rope 9 , which takes effect when the crane jib 2 is shortened. Then, the traction rope 9 is pulled through the described deflection equipment and at the same time the latching element 25 suspended so that there is a surplus of traction rope 9 that may be suspended at a suitable point on the crane support 2 so that this surplus is not an impediment.
[0019] The rope pulley 8 is provided with a pointer 26 and das suspension element 19 is provided with a pointer 27 . These pointers 26 , 27 interact with a scale 28 or 29 in such a way that it is easily possible to introduce a corresponding visible adjustment.
[0020] Decoupling the adjustment on two sides enables a clearer layout and a more effective setting.
[0021] FIG. 4 is a better illustration than FIG. 5 of the camera-side end of the crane jib 2 which shows the rope pulley 7 for the traction rope 9 with the articulation point 5 for the camera-receiving plate 6 and the articulation point 10 for the traction rope 9 . The camera-receiving plate 6 comprises two holding bars 30 , of which one is firmly connected to the rope pulley 7 , and therefore turns together with this, as may be seen more clearly in FIG. 6 , by the connecting element 31 . The holding bars 30 are firmly connected to an axis 32 mounted in rolling bearings 33 in a crane jib end piece 34 . In this example of an embodiment, attached to this axis 32 are two damping elements 34 , which are shown and described as damping disks which are known per se in DE 2657 692 C2. These damping disks comprise an inner disk, which, with an interposed viscous fluid, is able to turn inside an outer disk, whereby the inner disk is firmly connected to the axis 32 and turns with this when the camera-receiving plate 6 is swiveled. The circumference of the outer disk is provided with latching recesses, not shown here. Locking elements 35 may be screwed into these latching recesses, preferably spring-loaded. This puts the damping element into action, because the outer disk is secured on the jib side, while the inner disk is able to turn with the axis 32 and hence with the camera-receiving plate 6 , although it is damped by the viscous fluid. Optionally, one or two and, if there are more damping elements even more, damping elements may be switched on together or in different graduations. When the damping element 34 is switched off, the outer disk turns freely with the inner disk without this causing any relative movement between the inner disk and outer disk and a damping action.
[0022] If the crane jib 2 is swiveled in the three-dimensional space and the weight of the camera on the camera-receiving plate 6 causes the traction rope 9 to expand changeably, oscillations are transmitted by the traction rope 9 onto the camera-receiving plate 6 and hence onto the camera; these oscillations are to be prevented. This is achieved by decoupling these oscillations by means of the damping described above.
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The invention relates to a camera crane which comprises a crane jib ( 2 ) at the end of which a camera receiving platform ( 30 ) is pivotably mounted with dampening elements ( 34 ) interposed between. In this manner, the oscillations that are caused by a traction and control rope ( 9 ) expanding under the load of the camera can be dampened, thereby allowing a perfect operation of the camera.
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BACKGROUND AND SUMMARY
[0001] The disclosure relates to a swivel lock for a caster. In particular, the swivel lock may be configured to be actuated by a brake lever of the caster. The swivel lock comprises a male spline shaft and a female spline bushing which are releasably interlockable to prevent rotation of the caster about a swivel axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] FIG. 1 shows a perspective view of a caster with a swivel lock as described herein.
[0003] FIG. 2 shows a top view of the caster of FIG. 1 .
[0004] FIG. 3 is a front view of the caster of FIG. 1 .
[0005] FIG. 4 is a right side view of the caster of FIG. 3 .
[0006] FIG. 5 is an exploded view of the caster of FIG. 1 .
[0007] FIG. 6 is a cross-sectional view taken along lines 6 - 6 of FIG. 2 .
[0008] FIG. 7 is a cross-sectional view taken along lines 7 - 7 of FIG. 2 .
[0009] FIGS. 8-9 are perspective views of the caster of FIG. 1 with a body and wheels of the caster removed to provide additional detail of one embodiment of the swivel lock.
[0010] FIG. 10 is a perspective view of an embodiment of a stem assembly and a spline bushing comprising the swivel lock described herein.
DETAILED DESCRIPTION
[0011] The caster 20 has a body 22 which serves as a frame for the components of the caster. The caster 20 has first and second wheels 24 , 26 that rotate about a wheel axis 28 . The body 22 may have a portion 30 extending generally perpendicular to the wheel axis 28 . The perpendicular extending portion 30 may have a stem cavity 32 that receives a stem 34 of the caster. The stem 34 rotates relative to the body 22 along a stem or swivel axis 36 . The stem or swivel axis 36 is generally perpendicular to the wheel axis 28 . The caster 20 may have a leading brake lever 38 generally adjacent to perpendicular extending portion 30 of the body 22 , and a trailing brake lever 40 on the opposite side of the body. In the drawings, a two-wheeled caster is shown. In such a configuration, the leading brake lever 38 may be configured to prevent rotation of one wheel 26 , and the trailing brake lever 40 may be configured to prevent rotation of the opposite wheel 24 . The wheels 24 , 26 may be rotatably coupled to the body 22 with an axle 42 .
[0012] As best shown in FIG. 6 , the trailing brake lever 40 may be pivotally connected with the body with a pivot pin 44 . The trailing brake lever 40 may have a finger 46 extending from the lever that engages one or more detents 48 in the body to maintain the lever in a desired position. The body 22 may be provided with the detent 48 to fix the position of the trailing brake lever 40 in the unlocked position. The finger 46 of the trailing brake lever 40 may cooperate with the detent 48 and may have a curved distal end to allow the finger 46 to slide and transition into and out of the detent 48 . The trailing brake lever 40 may have a notch 50 , and a lock block 52 may be coupled to the trailing brake lever at the notch. The lock block 52 may be configured to slide (for instance, vertically as shown in FIG. 6 ) within the body 22 . The lock block 52 may be coupled to a wheel teeth lock 54 . The wheel teeth lock 54 may move within the body (for instance, vertically as shown in FIG. 6 ) to engage wheel teeth 56 formed on an inner diameter surface of the wheel 26 . The assembly of the lock block 52 and the wheel teeth lock 54 may be biased away from the wheel teeth 56 by a spring (not shown).
[0013] The trailing brake lever 40 may be rotated between an unlocked position in which the lock block 52 lifts the wheel teeth lock 54 upward out of engagement with the wheel teeth 56 to allow rotation of the wheel 26 about the body 22 , and a locked position in which the lock block forces the wheel teeth lock downward into engagement with the wheel teeth to prevent rotation of the wheel about the body. FIG. 6 show the trailing brake lever 40 in an unlocked position. Making reference to FIG. 6 , to position the trailing brake lever 40 to the locked position, the brake lever may be pivoted counterclockwise to drive the lock block 52 and the wheel teeth lock 54 downward. Downward force on the trailing brake lever 40 causes the lever to pivot about its pivot pin 44 , releasing the finger 46 from the detent 48 . The downward motion of the lever also moves the lock block 52 downward and drives the wheel teeth lock 54 against the wheel teeth 56 thereby preventing rotation of the wheel 26 about the wheel axis 28 . To re-position the trailing brake lever 40 to the un-locked position, the brake lever may be pivoted clockwise to raise the assembly of the lock block 52 and the wheel teeth lock 54 and release the wheel teeth lock from the wheel teeth 56 thereby allowing rotation of the wheel 26 about the wheel axis 28 .
[0014] Making reference to FIG. 7 , the leading brake lever 38 has a similar configuration. The leading brake lever 38 may be pivotally connected with the body with a pivot pin 58 . The leading brake lever 38 may have a finger 60 extending from the lever that engages detents 62 , 63 in the body to maintain the lever in a desired position. The body 22 may be provided with the detents 62 , 63 to fix the position of the leading brake lever in the locked and unlocked positions, respectively. The finger 60 of the leading brake lever may cooperate with the detents 62 , 63 and may have a curved distal end to allow the finger to slide and transition into and out of the detents. The leading brake lever 38 may have a notch 64 , and a lock block 66 may be coupled to the leading brake lever at the notch. The lock block 66 may be configured to slide (for instance, vertically as shown in FIG. 7 ) within the body 22 . The lock block 66 may be coupled to a wheel teeth lock 68 . The wheel teeth lock 68 may move within the body 22 (for instance, vertically as shown in FIG. 6 ) to engage wheel teeth 56 formed on an inner diameter surface of the wheel 24 . The assembly of the lock block 66 and wheel teeth lock 68 may be biased away from the wheel teeth 56 by a spring (not shown).
[0015] The leading brake lever 38 may be rotated between an unlocked position in which the lock block 66 lifts the wheel teeth lock 68 upward out of engagement with the wheel teeth 56 to allow rotation of the wheel 24 about the body 22 , and a locked position in which the lock block forces the wheel teeth lock downward into engagement with the wheel teeth to prevent rotation of the wheel about the body. FIG. 7 show the leading brake lever 38 in an unlocked position. Making reference to FIG. 7 , to position the leading brake lever 38 to the locked position, the leading brake lever 38 may be pivoted counterclockwise to drive the lock block 66 and the wheel teeth lock 68 downward. Downward force on the leading brake lever causes the lever to pivot about its pivot pin 58 releasing the finger 60 from the detent 62 . The downward motion of the lock block 66 also drives the wheel teeth lock 68 against the wheel teeth 56 thereby preventing rotation of the wheel 24 about the wheel axis 28 . To re-position the leading brake lever 38 to the un-locked position, the brake lever may be pivoted clockwise to raise the assembly of the lock block 66 and the wheel teeth lock 68 and release the wheel teeth lock from the wheel teeth 56 thereby allowing rotation of the wheel 24 about the wheel axis 28 .
[0016] The stem 34 is rotatably mounted in the stem cavity 32 to permit rotation of the stem relative to the body about the stem axis 36 . A bearing 70 may be provided to facilitate rotation of the stem 34 in the stem cavity 32 . The bearing 70 and stem 34 may be retained in the stem cavity with a stem cap 72 . Once installed in the application, weight applied downward to the stem 34 may also facilitate engagement of the stem and the bearing 70 in the stem cavity 32 . The stem 34 may comprise a spline shaft 74 . The spline shaft 74 may be disposed within a hollow interior 76 formed within the stem. A spring 78 may also be disposed in the hollow interior 76 of the stem 34 . The spline shaft 74 is prevented from rotation within the hollow interior of the stem 34 by a pin 80 . The pin 80 allows the spline shaft 74 to reciprocate (vertically in FIGS. 6 and 7 ) within the hollow interior 76 of the stem 34 without rotation about the stem axis 36 . The spline shaft 74 comprises a plurality of splines 82 extending around an intermediate section 84 of the spline shaft. The intermediate section 84 of the spline shaft 74 may be tapered. A distal end 86 of the spline shaft 74 may extend away from the intermediate section 84 along a center axis of the spline shaft.
[0017] In the stem cavity 32 , a spline bushing 88 is provided. The spline bushing 88 has an interior with a plurality of splines 90 and an exterior with a tab 92 which cooperates with the stem cavity 32 to prevent the spline bushing from rotation within the stem cavity. The splines 90 of the spline bushing 88 may cooperate with the splines 82 of the spline shaft 74 to allow releasably interlocking of the bushing 88 and shaft 74 together. The splines 90 of the spline bushing 88 may also be tapered to facilitate releasably interlocking of the bushing and shaft together. The stem cavity 32 may have an interior geometry to allow the spline bushing 88 to be inserted therein and constrained from movement. For instance, the spline bushing 88 may have features, including its tab 92 , which interlock with the body 22 in the stem cavity 32 so that the body and spline bushing may become integral, moving together as a unit relative to the stem when disengaged from the spline shaft.
[0018] The spline bushing 88 has a center axis, which may be co-linearly aligned with the center axis of the spline shaft 74 . While the drawings show the center axis of the spline shaft 74 co-linearly aligned with the stem center axis 36 , the spline shaft center axis may also be offset from the stem center axis. The spline shaft 74 may be movable along the spline shaft center axis toward the spline bushing 88 to engage with the spline bushing in the fixed position, and the spline shaft may be movable along the spline shaft center axis away from the spline bushing to disengage from the spline bushing in the swivel position. In the swivel position, the spline shaft 74 is spaced from the spline bushing 88 so as to allow free rotation of the stem 34 relative to the body 22 about the stem axis 36 . In the fixed position, the spline shaft 74 interlocks with the spline bushing 88 to prevent rotation of the stem 74 relative to the body 22 about the stem axis 36 . While the drawings show the spline shaft 74 moving relative to the spline bushing 88 , the arrangement may be reversed. For instance, in an alternate configuration, the spline bushing may be movable along the spline bushing center axis to engage with and disengage from the spline shaft. By way of example, this configuration may be employed where the stem is integral with the spline bushing and the spline shaft is integral with the body in the stem cavity.
[0019] The leading brake lever 38 may have a spline shaft stop 94 . When the leading brake lever is in the unlocked position, the spline shaft stop 94 may engage the distal end 86 of the spline shaft, maintaining the spline shaft 74 in a spaced-apart relationship with the spline bushing 88 and allowing the stem 34 and spline shaft to rotate together relative to the body 22 about the swivel axis (i.e., the swivel position). When the leading brake lever 38 is moved downward (for instance, clockwise in FIG. 6 ), the spline shaft stop 94 may disengage from the distal end 86 of the spline shaft 74 . The spring 78 housed in the hollow interior 76 of the stem 34 may force the spline shaft 74 downward ( FIG. 6 ) to engage the spline bushing 88 (i.e., the fixed position). The cooperating tapered features of the male and female splines 82 , 90 may facilitate engagement of the spline shaft 74 with the spline bushing 88 and provide good locking properties with little play. With the leading brake lever 38 in the locked position, and the spline shaft 74 and spline bushing 88 interlocked together in the fixed position, the stem 34 is locked with the body 22 and rotation of the stem relative to the body about the stem axis 36 is prevented.
[0020] To reposition the spline shaft 74 and spline bushing 88 to the swivel position, the leading brake lever 38 may be moved upward (for instance clockwise in FIG. 7 ) such that the spline shaft stop 94 may engage the distal end 86 of the spline shaft 74 and forces the spline shaft upward, releasing the spline shaft from the spline bushing 88 . Upward motion (for instance clockwise in FIG. 7 ) of the leading brake lever 38 acts against the pressure of the spring 78 . With the finger 60 of the leading brake lever engaging its upward detent 62 , the spline shaft 74 is moved upward so that the spline shaft spaced away from the spline bushing 88 (i.e., the swivel position).
[0021] While the drawings show a leading brake lever that is movable to engage the spline shaft and the wheel, the brake lever may operate solely to prevent rotation of the wheels, and a separate lever may be provided actuate the swivel or stem lock. To lighten the weight of the body, the body may be formed with interior radial spokes 96 in the stem cavity 32 . The stem bearing 70 may be mounted on upper flat faces on the spokes 96 in the stem cavity. Additionally, the brake levers 38 , 40 may be formed with clearance grooves 98 to allow relative motion of the brake levers relative to pivot pins 44 , 58 and the axle 42 within the body 22 .
[0022] The embodiments were chosen and described in order to best explain the principles and their application to thereby enable others skilled in the art to best utilize the various embodiments and with various modifications as are suited to the particular use contemplated. As various modifications could be made in the constructions and methods herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.
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A caster comprises a body including a stem cavity with a stem of the caster rotatably mounted in the stem cavity to permit rotation of the stem relative to the body about a stem access. The stem may comprise a spline shaft extending from the stem into the stem cavity. The stem and spline shaft are operatively connected. The stem cavity may have a spline bushing. The spline bushing and the body are operatively connected to each other. The spline shaft and the spline bushing are releasbeably interlockable. One of the spline bushing and the spline shaft may be movable in a direction along the stem axis between the swivel position wherein the spline shaft is not engaged with the spline bushing, and a fixed position wherein the spline shaft is engaged with the spline bushing.
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This application is a continuation-in-part of U.S. patent application Ser. No. 829,919 now abandoned in the name of Viljo K. Valavaara assigned to 685562 Ontario Ltd., as filed Feb. 18, 1986 and entitled "ROTARY PRESSURE INTENSIFIER".
FIELD OF THE INVENTION
The invention relates to a pressure intensifier for use in association with a pressurized fluid and for converting and intensifying the pressure of such a fluid.
BACKGROUND OF THE INVENTION
Devices are available for increasing fluid and liquid pressures, which are dependent on some outside power source or motor, i.e., pumps, compressors, etc.
Other forms of devices are directed to the intensification of the pressure of a fluid medium by utilizing the pressure of the medium as the power source. In other words, in theory this can be achieved simply by exchanging or transforming a given volume of medium at a first pressure with a reduced volume of medium at an increased pressure. A portion of the volume of the medium will thus become waste. A smaller volume at the increased pressure will then be obtained and utilized for whatever purpose it is required. Such systems offer attractive possibilities.
In many instances it is desirable to utilize a high pressure jet for example of water for cleaning, cutting, pulverizing or the like. However, in the great majority of cases, the approach to producing such high pressure jet is to apply some form of exterior power such as an electrical or other motor, and a pump.
These systems are therefore relatively expensive. In addition in, for example, a high pressure water jet powered by an electrical pump, rigid precautions are needed to ensure safety from electric shock. Complex continuous flow circulation systems are required to eliminate "hammer" and turbulence.
For many reasons, therefore, it is desirable where possible for a fluid pressure intensifier to operate solely from the pressure of the fluid medium. In the past, such self-powered pressure intensifiers as have been available were generally based on some form of double acting piston design. However, such earlier designs have generally speaking been relatively costly and cumbersome, involving numerous parts, and have also incorporated various inefficiencies, leading to considerable wastage in pressure and volume. One of the problems of earlier designs is the intermittent nature of the high pressure flow. Piston type intensifiers usually produce an intermittent flow in which the high pressure exists as a series of high pressure pulses. Clearly, it is desirable to use multiple pistons and to operate them at a sufficient speed to smooth out these pulses as far as possible.
One of the sources of inefficiency in prior art design is the power loss involved in returning each piston after its power stroke. It is desirable as far as possible to reduce this power loss and also to render the return stroke of the piston as far as possible free of interference or resistance.
In the case of compressors for fluids such as gases and air it is usual to employ a compressor having reciprocating pistons and connecting rods, and a crank shaft similar to the design of gasoline engines. Such a compressor is driven, via the crank shaft, by any suitable motor, e.g., a gasoline or diesel engine, in many cases.
Compressors of this design are known to be relatively inefficient and the manufacturing cost is relatively high. Maintenance costs can also be significant. The use of connecting rods and bearings involves large masses of metal reciprocating to and fro with consequent losses. In addition, reciprocating pistons of this type produce pressure only on one half of the stroke, the other half being merely a dead movement for return. Consequently, the fluid medium is subjected to pressure pulses. To overcome this, a pressure storage tank or accumulator is usually provided to accumulate fluid under pressure. This still further increases the expense.
Clearly, it is desirable to provide a compressor without these disadvantages, and in which mechanical movement is reduced.
In general the approach of the invention is to provide a pressure intensifier which utilizes the pressure of a fluid medium, i.e., air, water or a hydraulic fluid, to either increase the pressure of the fluid medium (e.g., the air, oil or water), or uses the pressure of one fluid medium to intensify the pressure of another fluid medium.
In either case the general principles of the pressure intensifier mechanism are generally similar, and the appearance is similar.
SUMMARY OF THE INVENTION
The invention seeks to overcome the foregoing disadvantages by the use of a pressure intensifier for a fluid medium having at least three piston assemblies disposed along mutually parallel axes equiangularly disposed with respect to a central axis of the intensifier and radially equidistant therefrom. Fluid is supplied to the low pressure cylinders from a supply means and discharged to a discharge means through a low pressure valve means operatively coupled to the pistons of the piston assemblies so as to be driven by axial movement of such pistons.
The invention relates to an intensifier for a fluid medium and comprising:
a stationary low pressure cylinder block portion;
stationary high pressure cylinder block portions;
at least three piston assemblies, said piston assemblies being disposed along mutually parallel axes equiangularly disposed with respect to a central axis of said intensifier and radially equidistant therefrom, each said piston assembly comprising:
low pressure cylinder means in said low pressure cylinder block portion;
a pair of axially aligned and opposed high pressure cylinders coaxially disposed with said low pressure cylinder means in said high pressure cylinder block portions;
low pressure piston means disposed within said low pressure cylinder means for axial movement therein; and,
a pair of high pressure pistons disposed within respective ones of said high pressure cylinders for axial movement therein, each said high pressure piston being connected to said low pressure piston means for conjoint axial movement therewith;
low pressure fluid supply means for the supply of low pressure fluid to said low pressure cylinder means of each said piston assembly;
low pressure fluid discharge means for the discharge of low pressure fluid from said low pressure cylinder means of each said piston assembly;
movable low pressure valve means in said low pressure cylinder block portion and disposed along a central axis thereof within said mutually parallel axes of said piston assemblies, and being movable within said low pressure block portion, said valve means being coupled to said low pressure cylinder means of each said piston assembly and adapted to control the supply of low pressure fluid to said low pressure cylinder means of each said piston assembly from said low pressure fluid supply means and to control the discharge of low pressure fluid from said low pressure cylinder means of each said piston assembly to said low pressure fluid discharge means;
valve drive transmission means operatively coupled to each of said piston assemblies between said two high pressure pistons of each said piston assembly, and disposed within said mutually parallel axes of said piston assemblies whereby movement of said piston assemblies in response to supply of low pressure fluid will cause movement of said low pressure valve means, and simultaneously synchronize movement of said piston assemblies;
high pressure fluid supply means for supplying fluid to said high pressure cylinders; and,
high pressure fluid collector means for receiving high pressure fluid from said high pressure cylinders.
In one form of such an intensifier, the low pressure valve means is driven by a valve drive transmission means operatively interconnecting the pistons of the piston assemblies to such low pressure valve means. In one arrangement, the valve means comprise a central rotary valve shaft with a rotary valve mounted on that shaft. The valve drive transmission means may comprise a swash plate which engages the pistons of each assembly.
In accordance with one feature of this invention utilizing such a swash plate, the valve means is in the form of a ball connected to or forming part of the swash plate so as to be movable therewith and which is movably supported in a fixed cup formed in the intensifier. A supply passage and a plurality of transfer passages communicating with respective ones of the low pressure cylinders, which passages open as ports in such a cup, are then provided for cooperation with recesses formed in the surface of the ball for permitting fluid transfer between respective pairs of said ports during operation of the intensifier.
In accordance with another feature of this invention, each piston assembly of such an intensifier comprises a pair of axially aligned and opposed high pressure cylinders coaxially disposed with the low pressure cylinder and a pair of high pressure pistons disposed within respective ones of the high pressure cylinders for axial movement therein, each high pressure piston being connected to the low pressure piston for conjoint axial movement therewith.
In such an intensifier in accordance with this invention each piston assembly preferably also comprises two low pressure cylinders with two low pressure pistons therein and such low pressure pistons of each piston assembly are connected to respective ones of the high pressure pistons of that piston assembly to provide first and second pairs of high pressure cylinders and pistons and low pressure cylinders and pistons. Linkage means are then provided between the first and second pairs of high and low pressure pistons in each assembly for transmitting axial movement therebetween.
In accordance with a particularly useful feature of such an intensifier in accordance with the invention, the high pressure cylinders and the low pressure cylinders of each piston assembly are interconnected and the low pressure pistons are connected to the low pressure valve means by the valve drive transmission means so that, in each piston assembly, axial movement of the low pressure piston of one of the first and second pairs of cylinders and pistons is effective through a respective one of the linkage means to cause axial movement of the high pressure piston of the other of the first and second pairs of cylinders and pistons.
In accordance with yet another feature of this invention, the high pressure cylinders and the high pressure fluid collector means of an intensifier of the type described form a closed circuit including pressure reaction means for reaction to high pressure therein.
In accordance with another useful feature of this invention, an intensifier of the type described is constructed with a multi-partite body so that the low pressure cylinders are located in a low pressure cylinder block portion and the high pressure cylinders are located in a high pressure cylinder block portion, the intensifier also including spacer means extending between such low pressure and high pressure cylinder block portions. Such multi-partite construction has proven to be particularly beneficial in facilitating maintenance and repair of such an intensifier.
In accordance with another feature of the present invention, an intensifier of the type described is provided with a novel design and construction for the high pressure collector means as well as with a novel construction in which the high pressure cylinders and the high pressuure fluid collector means comprises a closed circuit.
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 use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an exploded perspective illustration of a pressure intensifier according to the invention;
FIG. 2 is a sectional side elevation through the pressure intensifier of FIG. 1 when assembled;
FIG. 3 is an enlarged perspective of a detail of FIGS. 1 and 2 showing conduits in phantom, and partly cut away;
FIG. 4 is an enlarged plan view of FIG. 3, showing valves and conduits in phantom;
FIG. 5 is a perspective of the rotary valve and swash plate assembly;
FIG. 6 is a sectional elevation of a further embodiment;
FIG. 7 is a cut-away perspective of a portion of FIG. 6;
FIG. 8 is an illustration showing an alternative embodiment of an intensifier in accordance with this invention and which comprises a combined swash plate and valve assembly;
FIG. 9 is a fragmentary enlarged view of a ball and cup valve arrangement provided in the intensifier shown in FIG. 8;
FIG. 10 is an illustration of the ball forming part of the ball and cup arrangement of FIG. 9; and
FIG. 11 is an underview of the cup forming part of the ball and cup arrangement of FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Before describing the construction of the pressure intensifier according to the invention, it will be understood that what is described is suitable for use in a variety of different situations. For example, on a small scale, it may be used in domestic applications such as a bathroom accessory or a kitchen accessory, or on a slightly larger scale as an outdoor attachment to a garden hose for example. In other circumstances, it may be used commercially, for example, to provide hydraulic power from a compressed air source, or to provide a high pressure cutting jet.
It will, therefore, be appreciated that the invention is illustrated as a pressure intensifier per se. In use, it could be incorporated in some other article such as a hand-held water jet sprayer, dishwasher, bathroom appliance, or the like, as an integral component thereof.
For the present purposes, however, for the description of this invention, no such appliance or other device is illustrated.
On the other hand, the device might be incorporated in a simple system of liquid supply and outlet conduits, where the higher pressure liquid will be used somewhere downstream, in some other unrelated equipment.
With reference now to the drawings, it will be seen that the pressure intensifier shown in FIGS. 1 to 5 comprises a plurality, in this case, three, combined low and high pressure piston assemblies each of which is illustrated as 10a, 10b, and 10c. In this description, when a number of identical components are indicated by a numerical legend followed by alphabetical suffices, such components will collectively be indicated by the same legend without such suffices. For example, the piston assemblies 10a, 10b and 10c will be collectively referred to as assemblies 10.
Each low and high pressure piston assembly comprises a relatively large diameter low pressure piston 12 and a relatively small diameter high pressure piston 14. The two pistons 12 and 14 are connected together by a piston rod extension 16.
In the embodiment as illustrated, the high pressure piston 14 and the extension 16 are integral structures formed with the same diameter and of the same piece of material. It will, however, be appreciated that this is not necessary for the purposes of the invention.
In each of the piston rod extensions 16, there is provided a bearing notch 18, for purposes to be described below.
In order to receive the pistons 10, there are provided a low pressure cylinder body 20, and a high pressure cylinder body 22. The low pressure cylinder body 20 comprises a plurality of, in this case, three, low pressure cylinders 24a, 24b and 24c, formed around the perimeter of a circle, the centre of the circle being located along the mutual central axis of the bodies 20 and 22.
The lower ends of the low pressure cylinders 24 (as shown in the drawings) are open, and the upper ends of the cylinders 24 are closed by plug members 26. This arrangement is merely for the sake of simplicity and economy in machining and fabricating. The plug members 26 are of reduced diameter, to define an annular liquid flow space therearound, and are closed off at their upper ends by means of closure discs 28.
In order to supply low pressure fluid to the upper ends of cylinders 24, and thereby operate the low pressure pistons 12, there is provided a rotary valve assembly indicated generally as 30. The rotary valve assembly 30 is located within a central axial bore 32 formed in body 20. A low pressure fluid supply conduit 34 is formed through body 20, and communicates with bore 32. Fluid may be supplied by means, for example, of a supply hose or the like to a supply hose fitting indicated generally as 36.
The valve assembly 30 will be seen to comprise a central stem or shaft 38 of reduced diameter relative to bore 32. A sealing collar 40 closes off the lower region of bore 32 from access to low pressure fluid. An annular valve neck 41 is formed integrally with shaft 38 spaced above collar 40. An upper valve segment generally indicated at 42 is provided at the upper end of neck 41. Upper valve segment 42 is divided by axially extending valve partition wall 43.
A lower semi-circular transverse wall 44 partially separates lower valve neck 41 from upper valve segment 42. An upper semi-circular transverse wall 45 partially closes off the upper end of upper valve segment 42. Walls 44 and 45 are on opposite sides of segment 42.
Valve segment 42 is further provided with a fluid distribution face 46 and a fluid ejection face 47, which are on opposite sides of the axial partition wall 43.
As the valve assembly 30 rotates, fluid is first of all received in the lower valve neck 41, then transferred to the distribution face 46, and thus to the respective low pressure cylinder 24 forcing the corresponding low pressure piston 12 to move axially downwardly, as viewed in the drawing. When the low pressure pistons 12 move in the opposite direction, i.e., upwardly on the return stroke, fluid from the low pressure cylinders 24 is then ejected back to the valve assembly 30.
The upper end of bore 32 is open, so that fluid from valve face 47 can be ejected through, for example, low pressure fluid outlet fitting 32a (FIG. 2).
Bore 32 is provided with a plurality, in this case three, liquid supply and return ports 48, each port 48 communicating from upper valve segment 42, with a respective cylinder 24 adjacent the annular space surrounding plug 26.
A low pressure fluid transfer conduit 49 extends downwardly from the fluid supply conduit 34 for a reason to be described.
Shaft 38 is connected to a transmission device, in this case a swash plate shaft50, extending downwardly through the lower ends of bore 32. Shaft 50 has an angled bushing portion 52, carrying a rotary annular swash plate 54 (omitted from FIG. 5). Swash plate 54 rides in the notches 18, formed in the piston rod extensions 16.
The high pressure cylinder body 22 is formed of two separate body portions 60 and 62. This two-part construction facilitates its manufacture and repair in the event of failure. It will also be understood that the high pressure section of the intensifier is subject to considerable stresses during operation and is, therefore, more susceptible to fatigue failure. It is, however, also possible to manufacture the body 22 as a single body.
Body portion 60 is a disc-like member of relatively thin cross-section, and is formed with three high pressure cylinders 64, two of which 64b and 64c are shown in the drawings. These cylinders 64 are axially aligned with respective ones of the low pressure cylinders 24, so that the piston assemblies 10 can be received in the respective pairs of cylinders 24 and 64.
A central or axial opening 66 is provided to receive the shaft 50. Cylinders 64 are counterbored to provide recesses for seals 70 which are continuously engaged by the high pressure pistons 14 during operation of the intensifier.
A low pressure conduit passage 72 extends through body portion 60 for transfer of low pressure fluids in a manner to be described below.
High pressure cylinder body portion 62 is formed with high pressure cylinders 74a, 74b and 74c, aligned with cylinders 64 and cylinders 24. Body 62 also has an axial bearing opening 76 aligned with opening 66. Opening 76 receives bearing 78 on the lower end 68 of shaft 50.
A low pressure conduit passage 80 is formed through body 62, aligned with passage 72.
In order to distribute low pressure fluid, and to collect high pressure fluid, a collector and transfer plate 82 is provided beneath body 62. Plate 82 is provided with three high pressure fluid wells 84a, 84b, and 84c, which are axially aligned with respective ones of the high pressure cylinders 74.
A low pressure distribution well 86 is formed aligned with low pressure conduit passage 80. Wells 84 and 86 are interconnected with one another by a series of drillings or conduits in the radial plane as described below with reference to FIGS. 3 and 4.
The wells 84a, 84b and 84c are also connected by further drillings to respective high pressure outlet openings 88a, 88b and 88c. Suitable one-way check valves to be described below are incorporated in the plate 82 to control flow.
A high pressure fluid collector ring 90 fits around plate 82. Ring 90 is provided with an interior annular groove 92 and a single high pressure outlet 94.
The body 20, body portions 60 and 62, transfer plate 82 and collector ring 90 are held together by suitable bolts or clamps (not shown), the details of which are omitted for the sake of clarity.
A spacer ring 96 is fitted between body 20 and body portion 60, and encloses the space around swash plate 54. In order to communicate low pressure fluid from body 20 to transfer plate 82, a low pressure pipe 98 is provided, which is connected by any suitable means (not shown) to low pressure transfer conduit 49 in body 20. Low pressure pipe 98 passes through the space enclosed by spacer ring 96, and through passages 72 and 80, into well 86 in plate 82.
As best shown in FIGS. 3 and 4, plate 82 is provided with low pressure drillings or conduits 100a, 100b, 100c, each of which is provided with a respective one-way check valve 102a, 102b, 102c (not shown in FIG. 3).
The wells 84a, 84b, 84c are also provided with high presure conduits 104a, 104b, 104c, each of which contains a respective one-way check valve 106a, 106b, 106c (not shown in FIG. 3).
Conduits 104 terminate at outlets 88, and deliver high pressure fluid to groove 92 and outlet 94.
In operation, low pressure fluid is supplied through supply fitting 36 and conduit 34 to the valve neck 41 in bore 32. Simultaneously, low pressure fluid is also supplied via transfer conduit 49 and pipe 98 to distribution well 86 in plate 82. This low pressure fluid will flow from distribution well 86 through conduits 100 and one-way check valves 102 to the three high pressure cylinder wells 84.
Low pressure fluid from neck 41 will flow up to the distribution face 46 of valve segment 42. It will then flow into whichever one of ports 48 is registering with face 46. Fluid will then apply pressure to the upper surface of the respective piston 12, causing it to move downwardly, i.e., toward the high pressure cylinders 64 and 74.
As one of the high pressure pistons 14 moves downwardly within a respective one of the high pressure cylinders 64-74, the fluid in that high pressure cylinder will thereby be subjected to a pressure which is a multiple of the low pressure applied to the low pressure piston 12 by the low pressure fluid. The fluid in the high pressure cylinder will thus be subjected to a much higher pressure than that in the low pressure cylinder. The seals 70 are effective to minimize loss of high pressure fluid through the space between the high pressure pistons 14 and the cylinder bores 64.
As such high pressure piston 14 continues to move downwardly, it will force the high pressure fluid out of the respective high pressure outlet conduit 104 and through the respective one-way check valve 106 into the collector groove 92 in the collector ring 90.
As such high piston 12 is forced downwardly by the low pressure fluid, it will be course cause rotation of swash plate 54, thereby rotating the shaft 38, and bringing the distribution face 46 into registration with a new one of ports 48.
Rotation of swash plate 54 will also cause one of the other piston assemblies 10 to move upwardly, thereby ejecting the low pressure fluid from that low pressure cylinder 24. The low pressure fluid in that cylinder will then be ejected through the respective port 48 into registration with the ejection face 47. Finally, such fluid will pass out through outlet fitting 32a.
Thus so long as low pressure fluid is continuously supplied to the supply fitting 36, the piston assemblies 10 will continue to reciprocate down and up, converting a flow of low pressure fluid of a predetermined volume into a flow of high pressure fluid of a much smaller volume.
The rejected low pressure fluid which is not transferred downwardly to the high pressure cylinders, is merely allowed to run to waste.
Clearly, many variations may be made in the arrangement of the invention. While three pistons and cylinders are shown, it is obvious that there may be more pistons and cylinders, if desired. The rotary valve mechanism as shown is simply one example of a suitable valve mechanism which may be used to distribute the low pressure fluid to and from the cylinders. Many other forms of valve mechanisms may be suitable in other circumstances.
It will also be apparent that in the system already described, the same fluid is used both on the low pressure side and on the high pressure side. This may be suitable in many circumstances such as, for example, in the generation of a high pressure water jet from a lower pressure water source. This may be suitable for use in, for example, the bathroom or in the garden, or in many industrial or commercial applications where a simple high pressure water jet is required. It may also be suitable in high pressure cutting jet applications.
However, there are certain circumstances where it is desirable to use two separate fluids. In this case, an entirely separate source of fluid could be used for supplying the high pressure cylinders through the well 86 and supply conduits 100. In this case, the low pressure supply conduit 98 would not be provided.
Also, in this case, all of the low pressure fluid would be rejected through the outlet fitting 32a. This would have certain advantages where it was desired to keep the two fluids, namely the low pressure and high pressure fluids, separate.
It would also enable the use of compressed air as the low pressure source, and water or some other fluid as the high pressure fluid.
In still other circumstances, it may be desirable to provide for a completely sealed high pressure fluid system wherein there is no contact between the high pressure fluid and some other system to which the high pressure is to be applied.
This may be achieved by the embodiment of FIGS. 6 and 7. In addition, this further embodiment has certain other advantages in that it provides for essentially a double-acting pumping function, which may be arranged to provide a greater compactness and a greater high pressure flow or a larger number of pulses per unit of time than the embodiment of FIGS. 1 to 5.
The principle of operation of this alternative embodiment is essentially the same as that already described. Thus it will be seen to comprise upper and lower pumping units 200 and 202 respectively and which are essentially mirror images of one another. Each of the units 200 and 202 is provided with three low pressure cylinders 204 and high pressure cylinders 206, which are provided with respective piston sets 208. Each of these piston sets 208 comprises a low pressure piston 210 and a high pressure piston 212. The two piston sets 208 which are axially aligned with each other will be referred to as a piston assembly 198.
A central rotary valve shaft 216 is mounted in bearings 218 and is rotated by means of swash plate 220. Swash plate 220 interengages with notches 221 formed in intermediate connecting rods 222. Each intermediate rod 222 interconnects the two low pressure pistons 210, so that the two piston sets 208 which are in alignment with one another also move in unison as a piston assembly 198.
Connecting rods 222 are separate from low pressure pistons 210, and are movable relative thereto to accommodate movement of the peripheral edge of swash plate 220 in the radial direction.
In order to supply low pressure fluid to the low pressure cylinders 204, a pair of upper and lower valve assemblies 223 are mounted on the shaft 216, and both are rotated in unison by swash plate 220. The valve assemblies 223 are of somewhat similar design to the valve assembly shown in FIG. 1 and have inlet and outlet faces on opposite sides. Low pressure fluid will be supplied to the valve assemblies 223 by annular supply channels 224, which are both supplied by a single supply conduit 225, shown schematically. The annular channels 224 correspond to the annular neck 41 of FIG. 1, and supply fluid to the valve assemblies 223 around the full 360 degrees of rotation.
Transfer ports 226 connect with the low pressure cylinders 204, and outlet conduits 227 provide for the discharge of low pressure fluid.
The lower of the two valve assemblies 223 in FIG. 6 is shown in the supply mode, that is to say, with low pressure fluid flowing through the supply conduit 225, around the annular channel 224 and into the cylinder 204. The upper valve in FIG. 6 is shown in the return or outlet mode. In this mode, fluid is ejected through the end of the valve upwardly into the outlet conduit 227.
The upper and lower outlet conduits 227 are connected by conduit 228.
It will be noted that, in this embodiment, the two piston sets 208 are arranged in what may be called an axially opposed fashion, with the two low pressure pistons 210 facing toward one another and the two high pressure pistons 212 extending away from the assembly at opposite ends thereof.
The high pressure pistons 212 operate in cylinders 206 which are connected via passageways 230 to respective sealed bellows chambers 232 defined by bellows 234. The bellows 234 have piston heads 236 which may move to and fro in chambers 235 in response to pulses of high pressure from cylinders 206. The piston heads 236 are connected through passageways 238 by connecting rods 240 to cam members 242. Cam members 242 are slidable against springs 244.
Low pressure transfer passageways 246 connect outlet conduits 227 to passageways 238. Check valves 248 are located in passageways 246, and valves 248 seat cam members 242.
Valves 248 are operable to permit flow of low pressure fluid into passageways 238, to replenish any losses, when plunger rods 240 retract due to fluid leakage.
Screws 250 support cam members 242 in the desired positions in the passageways 238.
It will thus be observed that the high pressure fluid sides of the system are essentially closed sealed systems, so that high pressure pulses caused by high pressure pistons 212 will cause the piston heads 236 to extend and retract, within chambers 235.
Some other fluid such as, for example, oil or the like may fill the chambers 235 around the outside of the bellows 234. Such fluid may enter the chambers 235 via supply conduit 252, transfer conduits 254 and check valves 256.
Such fluid may exit from chambers 232 via one-way outflow valves 258, which are connected by an outflow conduit shown schematically at 260.
It will thus be seen that the high pressure pulses created by the six high pressure pistons 212, are transferred via the bellows 234 and pistons 236 to another fluid. In this way it is possible to use two different fluids in the system without them contacting each other.
Referring now to FIGS. 8 to 11 of the accompanying drawings, it will be noted that there is shown therein a pressure intensifier indicated generally and schematically at 300 and including, as did the intensifier shown in the FIGS. 1 to 5, a plurality of pairs of opposed and co-axial low pressure and high pressure cylinders 302 and 304 respectively, only one such pir being shown in FIG. 8 for the sake of simplicity. As will become apparent as the description herein proceeds, the intensifier 300 will be considered as having three such pairs of cylinders.
The low pressure cylinders 302 house pistons 306 while the high pressure cylindes 304 house pistons 308 of smaller radial dimensions. Other component parts of the intensifier 300 which are identical with those of the intensifier shown in FIGS. 1 to 5 will be identified by the same legends.
The pistons 306 and 308 of each pair are interconnected by a rod 310 which engages a swash plate generally indicated at 312. The swash plate 312 comprises a ball 314 which is movably seated in opposed cups 316 and 318 formed as fixed parts of the body of the intensifier 300. The ball 314 and the cup 316 cooperate so as to provide a low pressure fluid control valve in a manner yet to be described.
From FIGS. 8 and 9, it will be noted that the intensifier 300 is provided with fluid conduits 320 and 322 which are open at ports 326 and 328 respectively in the cup 316. The conduit 320 is a low pressure fluid inlet passage through which low pressure fluid is supplied from supply fitting 36 and supply conduit 34. The conduits 322 provide low pressure fluid transfer passages through which fluid is transferred to the pressure ends of the low pressure cylinders 302. It will be understood that a separate low pressure fluid transfer conduit 322 will be provided for each one of the low pressure cylinders 302. For example, in the particular embodiment illustrated, three such transfer conduits 322 are provided, conduits 322a and 322b being shown in FIGS. 8 and 9.
The positions and shapes of the supply port 326 and of the three transfer ports 328a, 328b and 328c are shown in FIG. 11.
For a reason which will become apparent as the description herein proceeds, a low pressure discharge transfer passage 334 is provided for the discharge of the fluid from the space 335 within the spacer ring 96 to the axial bore 32.
Reference will now be made to FIGS. 9, 10 and 11 from which it will be seen that the ball 314 is formed in its surface with two recesses 336 and 338. On tilting of the swash plate 312, the recess 336 is selectively and sequentially operable to interconnect the fluid inlet passage 320 with the fluid transfer passages 322 so as sequentially to supply low pressure fluid to the pressure ends of the low pressure cylinders 302. The annular recess 338 is operable sequentially to be aligned with the transfer passages 322 so as to permit discharge of low pressure fluid from the low pressure cylinders 302 during the discharge strokes of the low pressure pistons. Such discharged fluid flows through the recess 338 and into the space 335 containing the swash plate 312, so displacing fluid from that space through the discharge transfer passage 334 and into the axial bore 32.
It will be understood that such flow of the low pressure fluid through the space within the spacer ring 96 is possible and advantageous when the low pressure fluid is a liquid, such as oil, which will then be effective to lubricate the moving parts of the intensifier contained within that space 335. Obviously, where the low pressure fluid is not a lubricant, the annular recess 338 would be positioned so as sequentially to permit the flow of fluid from the low pressure cylinders 302 to a separate fluid discharge passage opening into the cup 316.
The foregoing is a description of preferred embodiments of the invention which is given here by way of example only. The invention is not to be taken as limited to any of the specific features as described, but comprehends all such variations thereof as come within the scope of the appended claims.
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A pressure intensifier for a fluid comprises at least three piston assemblies disposed along mutually parallel axes equiangularly disposed with respect to a central axis of the intensifier and radially equidistant therefrom. Each piston assembly has two opposed high pressure cylinders and low pressure cylinders. Fluid is supplied to the low pressure cylinders and discharged through a low pressure valve operatively coupled by a swash plate to the pistons of each assembly so as to be driven thereby. A high pressure collector, optionally in the form of a closed circuit, is provided for receiving high pressure fluid from the high pressure cylinders.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of provisional patent application Ser. No. 61/414,628, filed 2010 Nov. 17 by the present inventors which is incorporated by reference.
BACKGROUND
Prior Art
[0002] The following is a tabulation of some prior art that presently appears relevant:
[0000]
U.S. Patents
Patent Number
Kind Code
Issue Date
Patentee
6,481,244
B1
2002 Nov. 19
Wright
7,654,111
B2
2010 Feb. 2
Alley et al.
6,023,786
2000 Feb. 15
Burnett
4,377,079
1983 Mar. 22
Krueger
Patent Literature Publication
Dow Corning® Silastic® LC Series Liquid Silicone Rubber for High Volume Manufacturing, Product Selection Guide ©2006, Dow Corning Corporation
[0003] Typically an individual's most valuable piece of jewelry, both in terms of monetary and sentimental value is a ring, more specifically but not limited to engagement gemstone rings and wedding bands. Rings are kept throughout a lifetime and handed down to next generations. Everyday wear, work activities and active conduct (such as sports, hobbies such as gardening and beach activities) damage rings. Some such damage is caused by abrasives (such as dirt and sand), chemicals (such as chlorine, bleach and cleaning products) and oils (such as suntan and body lotions). My cylindrical one-piece elastomer ring cover with dome covers and protects rings while on a wearer's finger from such damage.
[0004] These rings include gemstones that protrude away from the body of the ring. It is the most valuable part of the ring. These gemstones are of different sizes (carats) and shapes (cuts) and varying heights of protrusion. If a wearer with a gemstone engages in active conduct it is at risk of coming dislodged. With this protrusion exists a need for a concave covering. Said ring cover has an oval dome that provides a concave covering for gemstones and their protrusion.
[0005] The ring bands (also known as guards) are of various widths. These bands often contain gemstones. In today's jewelry market there exist bands with gemstones on the underside and sides of bands in addition to top of bands requiring more protection to such delicate and valuable jewelry. Said ring cover's width will cover, but not limited to, 2 bands plus a gemstone ring.
[0006] Ring sizes are specified by jeweler ring sizing. The ISO (International Organization for Standardization) standard for ring sizes is ISO 8653:1986, which defines standard ring sizes in terms of the inner circumference of the ring measured in millimeters. In the United States, ring sizes are specified using a numerical scale, with quarter and half sizes. These jeweler sizes correspond directly to cylindrical one-piece elastomer ring cover with dome sizes: jeweler sizes 3-4 are Xtra Small, jeweler sizes 5-6 are Small, jeweler sizes 7-8 are Medium, jeweler sizes 9-10 are Large, jeweler sizes 11-12 are Xtra Large.
[0007] With the sentimental value of the rings exists the need for transparency of the elastomer material it is manufactured from. The wearer (especially new) needs to see their rings beneath the cover to be assured of their safety, to proudly display rings beauty and to be inconspicuous in the workplace. Highly transparent Silicone is my contemplation for this embodiment. In cases where the wearer does not need to see the rings beneath the cover, food grade Silicone provides the same high performance but manufactured in over 1300 beautiful Pantone® colors for protection and wearing enjoyment.
[0008] With today's technological advances in the manufacture of elastomers, it makes Silicone the perfect solution for my 2 embodiments. Silicone is a stretchy, soft elastomer material that enables ease of placement on finger and over rings. This is especially important in today's fast paced lifestyles. The silicone strength eliminates tear when stretched over protruding gemstone and ring bands and then rebounds back to cover's original shape. Cylindrical one-piece elastomer ring cover with dome far surpasses prior art in regards to structure and material.
[0000] a) Silicone is hypo-allergenic, no pores to harbor bacteria
b) Silicone protects and insulates
c) Silicone has excellent sealing performance
d) Silicone withstands temperature extremes, chemicals and solvents
e) Silicone is resistant to age, sunlight and moisture
f) Silicone is flexible
g) Silicone has stability at high temperatures
h) Silicone is comfortable
i) Silicone is durable
j) Silicone rebounds quickly
k) Silicone is tear resistant
l) Silicone (Medical Grade) is transparent
m) Silicone adjusts to various ring widths
n) Silicone is inexpensive to manufacture
o) The selection of Pantone® Matching Color System® color selection process provides security in selecting colors for the rings.
[0009] In view of the foregoing, said ring cover is the solution to ring protection, usage, comfort and structure. It accommodates the various sizes and shapes, protrusions and widths of rings. In view of the strong sentimental value its high transparency permits wearer to view their beautiful samples of love beneath said ring cover.
[0010] Other advantages will be apparent from a consideration of the drawings and ensuing descriptions.
SUMMARY
[0011] In accordance with 2 embodiments an elastomer ring cover comprises a cylindrical one-piece construction, with centered (lengthwise) concave oval dome. Manufactured by injection molding process using Silicone material with transparent and color capabilities. It easily passes over wearer's finger and rings to comfortably encircle the rings to completely cover and protect and aid in holding the rings upon the finger.
Description of Prior Art
[0012] Previously, ring covers or protectors prevented a person's rings while on their finger from slippage or coming off the finger completely. While this prevented possible loss it did not thoroughly protect the ring from damage, chemicals and abrasives. During activities, rings are subjected to possible damage, sweat, water, lotions, chemicals and abrasives such as dirt and sand.
[0013] Several types of rings covers/protectors have been proposed—for example, in U.S. Pat. No. 7,654,111 B2 (2010), U.S. Pat. No. 6,481,244 B1 (2002), and U.S. Pat. No. 6,023,786 (2000). These are all made of various cloth and elastic materials. Cloth and elastic material is not a good material to use because of its many disadvantages:
[0014] a) Cloth materials can rip easily during activities. The layers of materials can become caught on objects destroying the ring covers/protectors and harm can come to the rings including the gemstones.
[0015] b) Cloth materials when in contact with liquids such as water, salt water, chlorinated water and drinks can cause the material to stretch making it less effective in retaining its shape or seal.
[0016] c) Cloth materials have pores that can harbor bacteria.
[0017] d) Cloth materials do not insulate.
[0018] e) Cloth materials are not resistant to age or moisture such as sweat.
[0019] f) Cloth materials in previous patents named are not transparent therefore the rings beneath cannot be seen. In some work environments ring covers/protectors are best not seen by clients or customers of wearer.
[0020] Prior art is comprised only partially of elastomer materials which limits stretch wherein cylindrical one-piece elastomer ring cover with dome is comprised wholly of elastomer material providing complete stretch of ring cover.
[0021] Some prior art have separated ends making it possible for dirt and chemicals to get inside and damage rings. Wherein cylindrical one-piece elastomer ring cover with dome is one-piece.
[0022] Prior art only partially house the gemstone attached to the ring. Dome of said ring cover completely houses the gemstone.
[0023] Prior art is only partially translucent wherein said ring cover manufactured with but not limited to Silastic® LC 2004 is highly transparent. When said ring cover is manufactured with Silicone it is translucent (not partially translucent).
DRAWINGS
Figures
[0024] In the drawings, closely related figures have the same number but different alphabetic suffixes.
[0025] FIG. 1-1A Shows perspective view of main embodiment ring cover on finger of hand. 1 A shows transparent said ring cover on finger of hand.
[0026] FIG. 2 Shows top view of main embodiment ring cover.
[0027] FIG. 3 Shows side view of main embodiment ring cover with gemstone ring inside.
[0028] FIGS. 4A-4B Show cross-section of main embodiment ring cover. FIG. 4B shows 5 sizes of the ring covers, the corresponding diameters and cavity heights accordingly.
[0029] FIG. 5 —Shows main embodiment cavity of Dome
[0030] FIG. 6 —Shows main embodiment manufacture seams
[0031] FIG. 7 —Shows second embodiment
[0032]
[0000]
Drawing - Reference Numerals
4 Seams
6 Thickness
8 Cavity
10 Oval dome
12 Hand
14 Ring finger of left hand
16 Gemstone ring
18 Wedding band (guard)
20A South extension
20B North extension
[0033] As previously stated the highly transparent Silicone elastomer is my contemplation for 2 embodiments. Specifically but not limited to Silastic® LC 2004 Series product from Dow Corning®. Said Silastic material is highly transparent and has a high tear strength. One such variation among many is Xiameter® Brand liquid Silicone from Dow Corning®. It is a liquid Silicone and would require an additional step in the injection molding process. This is not cost effective. However the solid form is available from Dow Corning.
[0034] Silicone elastomer or rubbers are inorganic synthetic elastomers made from a crosslinked Silicone-based polymer reinforced with filler. They offer unique chemical and mechanical properties that organic elastomers can't match.
[0035] An elastomer is a polymer with the property of viscoelasticity (colloquially “elasticity”) generally having notably low Youngs modulus (measure of stiffness of an elastic material) and high yield strain (stress of material).
[0036] The hardness of elastomer material, or Shore A durometer, of these 2 embodiments is 40 durometer in both transparent and translucent (food grade) Silicone. I chose 40 because it stretches with just the right amount of stretch to bring ring cover over rings with ease. This 40 durometer is preferred but not limited to 40 durometer. Durometer can vary from 20-70 and up.
[0037] Dow Corning® has a manufacturing plant in China that can supply the solid Silastic® Silicone for the injection molding process. It has to be supplied from them as most China manufacturers don't carry high transparent Silicone only translucent.
[0038] Specifically, but not limited to food grade Silicone is my contemplation for the color said ring covers. Food grade Silicone is approved by the FDA for contact with food. Ring wearers come in contact with food which makes this a huge benefit for wearers.
[0039] Other elastomers include: Thermoplastic elastomers (TPE) aka. Thermoplastic rubbers, consisting of materials with both thermoplastic and elastomeric properties; Nitrile rubber; Neoprene or polychloroprene synthetic rubber: other brand name Silicone materials.
[0040] Injection molding is the process used to manufacture cylindrical one-piece elastomer ring cover with dome. Injection molding process is described: The injection molding process involves melting the plastic or Silicone for purpose herein, in an extrude and using the extrude screw to inject the material into a mold where it is cooled. Said ring covers are manufactured in 2 pieces, top with the dome and bottom. The bottom portion is where the printing can be put. After the 2 pieces are ready they are then melted together to form one-piece. There are 2 seals shown in FIG. 7 .
DETAILED DESCRIPTION
FIG. 1 - 1 A—First Embodiment
[0041] The main embodiment of elastomer ring cover with oval done is illustrated in FIG. 1 (finger on hand view). This elastomer ring cover is worn on a finger 14 . It is stretched upward and over gemstone rings 16 and wedding bands (also know as guards) 18 . The side extension from dome 10 southward covering ring bands beneath is 20 A. The side extension from dome 10 northward covering ring bands beneath is 20 B. Oval done 10 shape extends east to west. The oval dome 10 covers gemstones that protrude upward from ring band. This oval dome 10 accommodates various sizes of protrusions and various sizes of gemstone cuts (such as marquis, oval, round, square).
[0042] FIG. 1 shows the manner of wearing and using the elastomer ring cover. FIG. 1A shows a wearer using a transparent cylindrical one-piece elastomer ring cover with dome. When slid on the finger, the tubular area that meets the ring first is the south tubular area 20 A. Once said ring cover is in position next to the rings it is ready to be stretched over the gemstone. The person squeezes the oval dome between thumb and first finger and stretches upward and over rings. Then adjust the underside of elastomer ring cover till comfortably positioned over all rings FIG. 1 . It does not matter which end you start to put ring on with as the dome is centered within the cylindrical tube and both sides (north and south of dome) are of equal width.
FIG. 2 First Embodiment
[0043] FIG. 2 shows a top view of elastomer ring cover not on a finger. The east to west oval shaped dome can be noticed 10 . The north 20 B and south 20 A, equal size tubular side extensions top view can be noticed. If elastomer ring cover is transparent then top of gemstone and bands will be visible.
FIG. 3 —First Embodiment
[0044] FIG. 3 shows a side view of said ring cover over rings and not on a finger. The side view of the gemstone 16 shows how the gemstone is positioned inside oval dome 10 inside ring cavity 8 allowing for various sizes and cuts of gemstones. It shows how the gemstone part of the ring is housed 8 in the dome for maximum protection and minimal friction of the ring cover.
FIG. 4 A- 4 B First Embodiment
[0045] FIG. 4B is a chart that displays the 5 sizes of elastomer ring covers. They are based on jeweler ring sizes which are based on the International Organization of Standardization. The ISO standard for ring sizes is ISO 8653:1986, which defines standard ring sizes in terms of the inner circumference of the ring measured in millimeters. In the United States, ring sizes are specified using a numerical scale, with quarter and half sizes.
[0046] Cross-section of elastomer ring cover in FIG. 4A is a size 5-6 Small. The dimensions in FIG. 4A are related directly to FIG. 4B chart. The ISO ring sizes are in the first column. Next column shows the corresponding cylindrical one-piece elastomer ring cover with dome sizes of the 2 embodiments. The next column is finger diameter. This is the size of diameter around the finger that is holding the rings. The next column is the cavity dimensions. The cavity dimensions in FIG. 4B is the convex area where rings are housed, from the bottom of the inside of the ring cover to the top of the inside of the dome. In FIG. 4A shows inside of elastomer ring cover size 5-6 and the concave inside of the oval dome 10 .
[0047] The thickness 6 of the silicone material of the cylindrical one-piece elastomer ring cover with dome is 0.04 inches. In 2 embodiments the thickness is 0.04 inches typical in the complete said ring cover. By that is meant that in manufacture of the ring cover every part of the ring is of the same 0.04 in. thick. This thickness is my contemplation for 2 embodiments. It is thick enough for protection but at the same time it is thin enough for comfortable wear. It is not bulky like prior art.
[0048] The 2 side extensions (north—toward finger nail and south-toward hand) provide for multiple ring bands on either or both sides of gemstone ring. Various width sizes of ring bands are provided for in the preset length of the said ring cover. Length of said ring cover is 0.75 inches for all sizes. This length is my contemplation for 2 embodiments but it is not limited to this length. This length is from knuckle to where finger meets hand.
[0049] The use of Silicone provides for transparency and also the manufacture of any color inventor wants to produce. The use of selecting a Pantone® color is beneficial to the manufacturer and inventor as there is no guesswork involved. The color is simply picked from a color system book.
FIG. 5 First Embodiment
[0050] FIG. 5 shows the cavity of said ring cover and how well it houses the rings. The radius 0.19 is roughly half the thickness of the dome, and since there are two halves melted together it gives the dome a rounded shape. Inside this dome and the cylindrical shape is the cavity 8 .
FIG. 6 First Embodiment
[0051] FIG. 6 shows where the seams are in the product after manufacture. These seams are melted together in the injection molding process. These seams are very strong.
FIG. 7 Second Embodiment
[0052] FIG. 7 shows second embodiment of cylindrical one-piece elastomer ring cover. This embodiment is without the oval dome. All specifications apply of the first embodiment without the dome and in such the side extensions. The cylindrical one-piece elastomer ring cover is the same length 0.75 in as first embodiment. Without the dome there are no extensions. The sizes and durometer dimensions are same as main embodiment diameter dimensions. This second embodiment is for ring bands or flat rings without high protrusion gemstones.
CONCLUSIONS, RAMIFICATIONS AND SCOPE
[0053] Accordingly, the reader will see that the cylindrical one-piece elastomer ring cover with dome and the various embodiments can be used to cover and protect a wearers rings which include but not limited to, gemstone ring and ring bands (guards). If no gemstone ring is worn then additional embodiment of elastomer ring cover is appropriately chosen.
[0054] The reader will see that the Silicone is the superior solution of today's technology for coverage due to its many and vast advantages. The use of highly transparent Silicone enables coverage of rings without impairing the ability to see the sentimental and monetary valuable rings beneath.
[0055] The reader will see that the artistically perfected shape of said ring cover providing flexibility of various sizes and shapes of rings. An oval dome provides perfect housing for protrusions of gemstones. The wide length is for covering multiple ring bands.
[0056] The reader will see the wearable comfort of said ring cover due to its thin structure and lightweight material, that is still strong and durable.
[0057] The reader will undoubtedly see the many solutions that said ring cover provides a wearer.
Advantages
[0058] Accordingly several advantages of 2 embodiments are as follows: conforms to the various sizes of rings per jewelry store sizes as well as the various sizes of gemstones and their protrusions; with many outside factors that change our fingers daily, the expanding and contracting of fingers, sweating and weight loss or gain, the superior moisture resistant silicone material is the solution; there is less friction of the ring cover substrate to the gemstone and its prongs, because of the oval dome; the 5 sizes gives the wearer comfort and the option of wearing a tighter size to create waterproof sealing capabilities: rubber gloves won't rip when put on a wearers hand over rings. Gloves slip over said ring cover easily.
[0059] Although the descriptions in various embodiments contain many specifications, these should not be construed as limiting the scope of the embodiments. For examples;
The thickness of the Silicone can be made thicker. The oval dome could be made to be any shape such as square or heart shaped. Other materials such as glitter or scents can be added to Silicone during manufacture making it more marketable. More sizes can be made such as XXLarge for jeweler size 13-14. The side extensions can be made longer or shorter by changing the cylindrical length. An improved (future) elastomer can be used.
Furthermore, the elastomer ring cover has the additional advantages in that:
The Silicone can be printed on and embossed making it personalized. Any color in the Pantone® Color Matching System® can be used. Elastomer ring covers make it easy to put on rubber gloves while rings are on finger, with out causing the gloves to rip. Silicone is resistant to high temperatures, thereby, can withstand the dish washer and clothes dryer. Prevents scratching children with gemstone accidentally causing harm to skin.
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The main embodiment presents a cylindrical elastomer ring cover protecting a ring while worn on a finger with a dome that houses the protrusion of the gemstone. There is visibility of the rings in cavity of the ring cover when manufactured with transparent Silicone. When manufactured with food grade Silicone it is not transparent but translucent and in many colors. The Silicone provides the stretchability or softness (durometer) for ease of placing on fingers and over rings and holding rings on finger during active conduct.
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This application is a continuation of application Ser. No. 186,583 filed Sept. 12, 1980, now abandoned.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an electrostatic recording apparatus cabable of forming small non-recording regions in a recording field.
2. Description of the Prior Art
In an electrostatographic process, the distributions of the electrostatic charges and the electric field generally assume the state as shown in FIG. 1. In the case of depositing toner on the positive charges formed on an electrostatic image bearing layer a provided on a supporting electrode b, a small charged area A is developed as a solid black image portion while a large charged area B is developed heavily only in the peripheral portions thereof, which is well known as so-called "edge effect".
Such image development is suitable for the recording of line images, but is unadequate for recording the image involving large solid areas. However such edge effect in a large solid area can be reduced by constituting such a large area by dots or small regions as shown in FIG. 2.
SUMMARY OF THE INVENTION
An object of the present invention is therefore to provide an electrostatic recording apparatus capable of preventing deterioration of image quality resulting from the edge effect.
Another object of the present invention is to provide an electrostatic recording apparatus capable of selecting portions of an image which cause deterioration of image quality in the recorded image and improving the image quality in such portions.
Still another object of the present invention is to provide an electrostatic recording apparatus capable of improving image quality in the recording apparatus utilizing a laser beam.
Still another object of the present invention is to provide an electrostatic recording apparatus capable of improving image quality by employing a laser beam in the recording apparatus of the type in which an image is formed by irradiating a photosensitive member with an original image.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1 and 2 are schematic views showing the distributions of the electrostatic charges and the electric field on the photosensitive member;
FIGS. 3 and 4 are a cross-sectional view and a perspective view, respectively, of an electrostatic recording apparatus embodying the present invention;
FIG. 5 shows a waveform of the laser modulating signal;
FIG. 6 is a plan view of an electrostatic image formed on the photosensitive drum;
FIG. 7 is a graph showing the MTF plots of an electrostatic image formed on the photosensitive drum;
FIG. 8 is a schematic block diagram of the control circuitry for laser recording;
FIG. 9 shows waveforms of various signals in the control circuit shown in FIG. 8;
FIG. 10 is a plan view showing an exemplary image formed according to the present invention;
FIG. 11 is a schematic block diagram of the control circuitry for forming small regions in a recording field according to the present invention;
FIGS. 12, 13 and 14 show waveforms of various signals appearing in the control circuitry shown in FIG. 11;
FIG. 15 is a schematic circuit diagram of the masking signal generating circuit;
FIG. 16 depicts waveforms of various signals in the circuit shown in FIG. 15;
FIG. 17 is a schematic circuit diagram showing another embodiment of the masking signal generating circuit; and
FIG. 18 depicts waveforms of various signals appearing in the circuit shown in FIG. 17.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Now the present invention will be clarified more in detail by the description of the embodiment thereof.
Reference is at first made to FIGS. 3 and 4 showing, respectively in a cross-sectional view and a perspective view, apparatus embodying the present invention, which is capable of performing combined functions as of a copier or duplicator (hereinafter called the copier mode) and of a laser beam printer (hereinafter called the LBP mode).
The copy mode section is composed of an original document 1, an imaging lens 2, a mirror 3 and an illuminating system 4, wherein an image of an original 1 illuminated by the illuminating system 4 is projected through the mirror 3 and the imaging lens 2 on a photosensitive drum 10. In the copy mode the apparatus is used singly as an ordinary document copier.
In the LBP mode, a laser beam generated by a laser unit 11 is introduced into the entrance aperture of a modulator 12 which may be composed of an acousto-optical deflecting-modulating device utilizing a known acousto-optical effect or of an electro-optical device utilizing a known electro-optical effect, wherein the laser beam is subjected to an intensity modulation according to the input signal to modulator 12.
Modulator 12 may be omitted in case the laser unit is composed of a semiconductor laser or of a internally modulated gas laser allowing current modulation or having a modulating device in the oscillating light path.
Such a laser beam from the laser unit is introduced, after passing a suitable optical system, into an beam expander (not shown), which expands the diameter of the laser beam with its parallelness maintained. The laser beam with its diameter thus expanded is then introduced into a polygonal rotary mirror 13 having plural mirror faces. Polygonal rotary mirror 13 is fixed on a shaft supported by a high precision bearing, such as an air bearing, and is rotated in a direction of arrow F by a constant-speed motor 14, such as a hysteresis synchronous motor or a DC servo motor, to cause the scanning motion of the laser beam in a direction substantially parallel to the rotary axis of the drum. Such scanning may also be achieved by means of a galvano mirror.
The laser beam put into horizontal scanning motion by means of polygonal rotary mirror 13 is focused, by an imaging lens 15 having the f-θ characteristic, which will be discussed below, as a spot on the photosensitive drum 10.
In an ordinary imaging lens, the focus position r on the image plane is related with the incident angle θ by the following relationship:
r=f·tan θ (1)
wherein f is the focal length of the imaging lens. On the other hand, in the present embodiment, the incident angle of the laser beam reflected by the rotary mirror 13 of a constant rotating speed with respect to the imaging lens 15 varies with time according to a linear function. Consequently the moving speed of the spot focused across the photosensitive drum 10 constituting the image plane is not constant but changes non-linearly, becoming larger at the point where the incident angle becomes larger. Consequently a series of spots formed by the laser beam pulses of a determined time interval will appear more dispersed in the lateral end portions than in the central portion of the photosensitive drum 10. In order to prevent such a phenomenon the imaging lens 15 is so designed as to have the following relationship:
r=f·θ (2)
and such a lens is called an f-θ lens.
In the case of focusing a parallel beam with an imaging lens, the minimum spot diameter d min is given by:
d.sub.min =fλ/A (3)
wherein f is the focal length of the imaging lens, λ is the wavelength of the light and A is the entrance aperture of the imaging lens, so that a smaller spot diameter will be obtained by increasing the value of A for given values of f and λ.
The aforementioned beam expander is employed in consideration of this fact, and may therefore be omitted with in case a desired value of d min is already obtained with the beam diameter from the laser unit.
A beam detector 17, composed of a small entrance slit and a rapid-responding photoelectric transducer, such as a PIN diode, is provided for detecting the position of the laser beam 16 during the scanning motion and thus determinning the timing for starting the input signals to the modulator 12 for providing desired optical information to the photosensitive drum. In this manner it is rendered possible to reduce the effects resulting from the errors in the precision of mirror faces of the rotary mirror 13 and in the horizontal synchronization of input signals, thus achieving an improved image quality and permitting a larger precision tolerance in and thus a cheaper manufacture of the polygonal rotary mirror 13 and the motor 14.
In the above-explained manner the photosensitive drum 10 is exposed to the laser beam 16 modulated with the input signals.
Now there will be explained how the printed image is obtained. A photosensitive member 10 essentially composed of a electroconductive substrate, a photoconductive layer and an insulative layer is charged, on the surface of the insulating layer, negatively and uniformly with a corona discharger 18 for the initial charging. Successively, the insulating layer, thus charged negatively and uniformly, is subjected to image exposure with the laser beam, and is substantially simultaneously subjected to positive recharging by a corona discharger 19 or to charge elimination by an AC corona discharger. Subsequently the insulating layer is entirely exposed to a lamp 20 to form a surface potential difference, thus creating an electrostatic image on the photosensitive member.
The electrostatic image is rendered visible in a developing unit 5 by toner deposition, wherein developing unit 5 and the toner are so designed and selected as to cause such toner deposition not in the regions exposed to the light or light beam but in the regions not exposed to such light or beam.
The toner image thus formed on the photosensitive drum 10 is transferred onto a recording sheet supplied from a cassette 6-1 or 6-2 and subsequently fixed on the sheet by heating or by applying pressure in a fixing unit (not shown).
The aforementioned copy mode and LBP mode may be conducted independently, but these two modes can be combined to alleviate the deterioration of the image quality observed in case the copy mode is conducted alone.
Such combination is achieved by forming the image of the original 1 on the photosensitive drum 10 through the imaging lens 2 and simultaneously irradiating the drum with a laser beam modulated with clock pulses of a determined frequency.
More specifically a generator 7 generates a modulation signal, having a repetition period t1 and a duration t2 as shown in FIG. 5, of a predetermined frequency (for example 4 MHz) synchronized with the beam detection by the beam detector 17, and the laser unit receives the modulation signal for modulation in such a manner that the laser beam 16 is emitted only during the pulse durations t2. In this manner the photosensitive drum receives, in the case of a solid black original, no light therefrom but receives the laser beam modulated with the modulation signal as shown by MB in FIG. 6 to provide, after image development, a screen-like pattern by the toner deposition only in the hatched portions in FIG. 6. On the other hand, in the case of a solid white original, the photosensitive drum receives the light reflected from the original over the entire surface. Although the photosensitive drum receives the modulated laser beam also in this case, the exposure state of the drum is not affected thereby since it is already exposed to the light from the original. In this manner the exposed area gives a white image in the ordinary developing process. The spatial frequency r1 of dots and the width r2 thereof are determined in the manner described in the following.
FIG. 7 shows a modulation transfer function (MTF) curve of an electrophotographic image in the copy mode, for example obtainable in a copy mode described in the Japanese Patent Publication 23910/1967, giving the modulation transfer in the ordinate as a function of the spatial frequency in the abscissa, wherein the curves (a), (b) and (c) respectively show the modulation transfer functions of latent image formation, image development and transfer, and entire image reproduction from latent image formation to final image output. As will be understood from FIG. 7 the steps of image development and transfer give rise to the eminent edge effect peaked at a spatial frequency of 5-6 lp/mm, and this fact contributes to the image quality in the copier.
Namely in the ordinary document copying involving principally images in the form of, the clear and sharp reproductions are obtained because of this fact.
Consequently a sufficiently high image density is obtained even in the solid black original if the spatial frequency of the screen dots is selected in the range of 5-6 lp/mm.
On the other hand the resolving power in the visual observation of an obtained copy will be lowered if the white regions formed of the screen dots are sufficiently resolved by the human eyes. For this reason the dimension r2 of the white regions is so selected preferably as to satisfy a condition r2<<r1. As will be understood from the curve (a) in FIG. 7, the modulation transfer function of the latent image extends to a considerably high spatial frequency.
Consequently an electrostatic latent image has satisfactorily resolvable white dots of a sufficiently small dimension though with a somewhat deteriorated response, whereby the state of electric field becomes close to that shown in FIG. 2. Such white dots are not resolved in the image development and transfer steps so that no disagreeable impression is given to the human eyes by the presence of such screen dots. From the foregoing consideration it is desirable to adopt the conditions r2<<r1 and f1≃5-6 lp/mm, wherein f1=1/r1.
It is thus possible, in the above-explained manner, to reduce the presence of undeveloped regions in the reproduced image resulting from the edge effect. However such process is perferably applied selectively to the images containing continuous tone, such as photographs, since the screen dots overlaid on the line images, such as characters, will inevitably cause slight deterioration of the image quality.
In contrast to the foregoing embodiment in which the screen dots are employed in the recording of an original image, there will be explained in the following the use of screen dots in the recording in the copy mode or LBP mode alone.
Reference is now made to FIG. 8 showing the recording control for a laser beam printer, in which a signal generator 21 generates image signals, for example in the form of a dot matrix, or array, character pattern, as parallel signals in response to the readout signals supplied from a memory contained in signal generator 21. Thus, in case a character is for example composed of n×m dots arranged in n dots in each line and in m dots in each column, there will be simultaneously produced n pixel signals in a parallel manner over signal lines SLI, corresponding to a line in the dot matrix.
The pixel signals are stored in a shift register 22 and supplied therefrom as serial image signals to drive a semiconductor laser 23, thereby causing the emission of a laser beam modulated according to the image signals. The laser beam is deflected by a scanner 13 and is focused by a lens 16 onto the photosensitive drum 10.
Photosensitive drum 10 is naturally provided on the periphery thereof with a member for electrostatic image formation as explained in relation to FIG. 3. Different from the foregoing embodiment, the toner deposition in the present embodiment is designed to take place in the regions exposed to the light. However it is also possible to cause toner deposition in the regions not exposed to light by suitable selection of the signals and the developing unit.
Thus, in case the shift register 22 stores n bits of logical "1" signals as an example, the semiconductor laser 23 receives the logical "1" signals until the completion of the readout of the n-bit signals from the shift register, thus continuously emitting the laser beam during the readout.
In order to synchronize the image signals with the laser beam for scanning the drum 10, the beam detector 17 detects the beam position immediately before the start of scanning motion of the laser beam on the drum 10 and generates a detection signal BD which is supplied as a trigger signal to an image clock synchronizing circuit 24 to control the timing of image transfer clock pulses supplied to shift register 22. Shift register 22 is thus shifted in response to clock pulses to obtain an image on the drum 10 in synchronism with signal BD, as shown in FIG. 9B.
For the purpose of the beam detection by the beam detector 17, the semiconductor laser 23 has to be activated to emit the laser beam prior to the start of scanning motion.
The laser beam emission from the semiconductor laser 23 in synchronism with the detection signal from beam detector 17 is achieved by an unblanking signal generator 25, which produces an unblanking signal at a determined time after the beam detection signal and terminates the unblanking signal as shown in FIG. 9C.
The unblanking signal and the aforementioned image signals are added in an adding circuit 26, of which addition output signals are used for controlling laser 23.
In such a laser beam printer a large solid image region is converted into a group of dots by a modulation suitably interrupting the serial image signals.
Such conversion however is not adequate in case the large solid image regions are mixed with line images since the line images can be reproduced more sharply with the edge effect and becomes deteriorated by the staggered line structure if the image signals are interrupted.
Consequently it becomes necessary to distinguish the large image regions from the small image regions before conducting the signal interruption as explained above.
Another difficulty lies in the fact that, even in large image regions, the edge portions thereof are already developable sufficiently and will therefore show disagreeable staggered edges if the dot structure is adopted in such portions. Thus the interruption of the image signals as explained above should be effected after an internal portion of an image region is distinguished from edge portions thereof, since such interruption is only needed in such an internal portion.
The above-mentioned difficulties are avoided in accordance with the present embodiment by identifying the shape and size of the image area and modulating the image signals according to the result of such identification. FIG. 10 illustrates an example of the image obtained according to the present embodiment, wherein a square large-sized image region composed of 6×6 pixels to be reproduced in black is given white pixels in a staggered manner in the non-edge portion, whereby the hatched parts in FIG. 10 are reproduced in black while the other parts remain in white.
The identification of non-edge pixels in a large image regions during the recording operation on the laser beam printer is to be achieved by the inspection of surrounding pixels. For example the identification of the pixel a in FIG. 10 is achieved by the inspection of the already recorded pixels and those to be recorded. For this purposes there are provided three line memories, respectively for a line already recorded, a line currently under recording and a line to be recorded next.
Based on these three line memories, it is possible to identify that a pixel to be recorded has to be white if all the nine pixels, i.e. that pixel and the surrounding pixels, are black. However, in order to obtain a staggered arrangement of such white pixels, each white pixels has to have immediately neighboring black pixels in the vertical and horizontal direction. For this reason it is necessary to effect a masking operation with such a signal as having a period of two pixels and inverting the phase in the neighboring lines.
Now the control method in this embodiment will be discussed in relation to FIG. 11, wherein the same components as in FIG. 8 are represented by the same reference numerals.
The image signals supplied from the signal generator 21 associated with a beam scan line are received at a terminal 30 and stored in a line memory 31. The storage is conducted during a period t1 shown in FIG. 12C, in which the image recording by the laser beam is not conducted.
Then the beam position detection signal BD is developed as shown in FIG. 12A at the start of each laser beam scanning across the photosensitive drum as already explained in the foregoing, and in synchronism with that signal the image write-in signals are supplied to the laser unit as shown in FIG. 12B.
In the image write-in signals the actual image signal segments VS exist only until a time T1, after which there is an empty period t1 until the succeeding detection signal BD containing no signals except the unblanking signal UB, and during the period effected is the parallel transmission of the image signals as shown in FIG. 12C from the signal generator 21 and the storage thereof in the line memory 31.
At the signal storage the address of the line memory 31 is set in response to an address signal (FIG. 13A) supplied from a line memory address counter 37, and a memory selection signal (FIG. 13B) is simultaneously generated. A line memory control 38 supplies a write-in instruction signal (FIG. 13C) to the line memory, and simultaneously supplies an image signal transmit instruction pulse (FIG. 13D) from a terminal 39 to the signal generator 21, whereby a block of parallel signals for example of n bits as shown in FIG. 13E is entered from signal generator 21 to the terminal 30 and stored in the line memory 31. Upon completion of the signal storage at an address location, the line memory control 38 produces a signal for incrementing the line memory addressing counter 37, and the above-explained procedure will be repeated. The signal storage into the line memory 31 is conducted in a shorter transmission time because of the parallel signal transmission, compared with the image signal period in which the same amount of image signals is transmitted in a serial manner, as shown in FIG. 12C, and is thus completed, for example in the case of 8-bit parallel transfer, within 1/8 of the time period required for serial signal transmission.
A single block of the image signals stored in the line memory 31 is loaded into a shift register 34 in response to the positive-going edge of a load pulse (FIG. 14B) supplied from a shift register control 40, and is shifted by image transfer clock pulses (FIG. 14A) supplied from an image clock pulse generator 41. The image signals thus loaded in the shift register 34 will be transferred, immediately after the loading, to a line memory 32 over a signal line SL and in synchronism with the memory write-in pulses shown in FIG. 14C. Addresses of the storage in the line memory 32 are designated by the line memory address counter 37 and is made in the same addresses as in the line memory 31. The address allocation of the line memories 31, 32 and 33 is conducted, as shown in FIG. 14E, prior to the loading of the shift registers 34, 35 and 36. The image signals loaded in the shift register 35 from the line memory 32 are transferred to the line memory 33 in the same manner as explained in the foregoing. The image signals loaded in the shift register 35 are shifted with the image transfer clock pulses shown in FIG. 14A to provide serial image signals as shown in FIG. 14D.
Stated differently, in response to the storage of a block of signals from the terminal 30 to the line memory 31 and the signal readout of a block of signals from line memory 31 to the shift register 34, the block of signals readout from the line memory 31 is stored in the line memory 32 and simultaneously a block of signals readout from the line memory 32 is stored in the line memory 33. Also the shift registers 35 and 36 respectively receive the signals readout from the line memories 32 and 33.
The image signals loaded in the shift registers 34, 35 and 36 are respectively transferred to flip-flops 42, 43 and 44 in synchronism with the image transfer clock pulses, then further transferred through flip-flops 45, 46 and 47 to flip-flops 48, 49 and 50 again in response to the clock pulses, and in response to such signal transfer new signals are supplied in succession from the shift registers 34-36 to the flip-flop 42-44.
Flip-flops 42-50 constitute three 3-bit shift registers, in which the flip-flops 42, 45 and 48 store the image signals of the line to be printed next, while the flip-flops 43, 46 and 49 store those of the line currently under printing, and the flip-flops 44, 47 and 50 store those of the preceding line already printed. The flip-flop 46 stores the signal of a pixel now printed and supplies an output signal over a signal line SL-9, while the flip-flops 43, 49 respectively store the signal of a pixel already printed before and the signal of a pixel to be printed next. In this manner the image signals of the pixel current under printed and the surrounding pixels are stored in the flip-flops 42-50, and it is therefore possible to identify whether the point currently under printing and the surrounding points are all black by checking, by means of an AND gate 52, if the output signals of the flip-flops are all in its high-level state. The region subjected to such identification can naturally be expanded by increasing the number of those line memories and flip-flops. In case said points are identified as entirely black, a masking signal from a masking signal generator 51 is supplied through a NAND gate 53 to an AND gate 54 to interrupt the serial image signals.
Masking signal generator 51 is shown in detail in FIG. 15, with an associated timing chart in FIG. 16. The image transfer clock pulses (FIG. 16A) synchronized with the aforementioned beam position detection signal BD shown in FIG. 16B are supplied from the aforementioned image clock generator 41 to a terminal 60 and are divided into half in frequency by a flip-flop 61, which produces in turn the signals shown in FIGS. 16E and 16F respectively from the output ports Q and Q thereof. As the flip-flop 61 is cleared by the beam detection signal BD developed at the start of each scanning line, the signals shown in FIGS. 16E and 16F always assume a determined phase at the start of each scanning line. The two signals have phases mutually inverted, and one of the two signals is selected as the masking signal for each other.
The selection is effected by a flip-flop 62 which divides the beam detection signal BD received at a terminal 63 into half in frequency, whereby the output signals from the ports Q and Q thereof are inverted for each line as shown in FIG. 16C and 16D. AND gates 64, 65 are provided to transmit the aforementioned signals shown in FIGS. 16E and 16F respectively only when the signals shown in FIGS. 16C and 16D take their high state.
The output signals from the AND gates are supplied to an OR gate 66, which in fact receives the signal of FIG. 16E or of FIG. 16F since the signals shown in FIGS. 16C and 16D are mutually inverted, and which thus generates the masking signal shown in FIG. 16G through a terminal 67. The masking signal has a repeating period corresponding to two image transfer clock pulses or to two pixels and is inverted in phase line by line, whereby the serial image signals interrupted by such masking signal provide a staggered or checker-board arrangement of white dots in a black image region. In this manner it is rendered possible to alleviate the density loss in a black image region by the edge effect.
Also the line image and the edge portions of large image region maintain a sharp and smooth image line since the masking is effected only when all the nine points, i.e. the point now in recording and the surrounding points, are identified as black and thus is not applied to the line images or the edge portions of large image regions.
FIG. 17 shows another embodiment of the masking signal generator, which is featured by the presence of a one-shot multivibrator for varying the pulse duration of the masking signal and of a terminal 74 for instructing whether the masking operation is to be conducted or not.
In this embodiment the output signal of the OR gate 66 is supplied to an additional gate 70 which also receives a masking control signal as shown in FIG. 18G from a terminal 74, whereby the state of the masking control signal determines whether the masking signal is produced on the signal line SL-10 or not.
The masking signal on signal line SL-10 is supplied to a terminal 72-1 of a switch 72, and also to a one-shot multivibrator 71 of which output signal is supplied to the other terminal 72-2 of switch 72, whereby the masking signal obtained will assume such a form as shown in FIG. 18H when the contact arm 72-3 of switch 72 is in contact with the terminal 72-1 while it will assume a form as shown in FIG. 18I having a pulse duration TM2 determined by the time constant of the one-shot multivibrator when contact arm 72-3 is in contact with the terminal 72-2. Pulse duration TM2 is adjustable to a desired value by rendering the time constant variable.
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Electrostatic recording apparatus forming small non-recording regions in a recording field includes a beam generator generating a beam modulated with a modulation signal, an irradiating unit directing the beam to a photosensitive member to form an electrostatic image, a determination circuit determining when the electrostatic image formed by the beam on the photosensitive member exceeds a predetermined size, an interruptor for intermittently interrupting the emission of the beam at small time intervals, and an actuating circuit actuating the interruptor when the determination circuit determines when the electrostatic image exceeds the size.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to PCT Application No. PCT/US12/42269 filed Jun. 13, 2012, which claims priority to U.S. application Ser. No. 13/253,197, filed on Oct. 5, 2011, now issued as U.S. Pat. No. 8,365,317, which is a continuation-in-part of U.S. application Ser. No. 12/823,873, filed on Jun. 25, 2010, now issued as U.S. Pat. No. 8,060,953; the entirely of these applications is incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to toilet systems, and more particularly, to an automatic toilet seat cleaning system that also serves to hygienically cleanses and dries a user of such system.
BACKGROUND OF THE INVENTION
[0003] Applicant believes that one of the closest references corresponds to U.S. Patent Application Publication No. 2006/0064810, published on Mar. 30, 2006, to Teranishi et al. for a human private part washing apparatus.
[0004] Applicant believes that another reference corresponds to U.S. Patent Application Publication No. 2005/0246828, published on Nov. 10, 2005, to Shirai et al. for a hygiene washing apparatus.
[0005] Applicant believes that another reference corresponds to U.S. Patent Application Publication No. 2005/0028263, published on Feb. 10, 2005, to Wodeslaysky for a water and space conservation toilet/bidet combination.
[0006] Applicant believes that another reference corresponds to U.S. Pat. No. 7,216,374 issued to Hassan on May 15, 2007, for a smart toilet seat.
[0007] Applicant believes that another reference corresponds to U.S. Pat. No. 7,191,473 issued to Matsumoto et al. on March 20, 2007, for a sanitary washing apparatus.
[0008] Applicant believes that another reference corresponds to U.S. Pat. No. 7,155,755 issued to Olivier on Jan. 2, 2007, for a toilet seat having a cleansing facility.
[0009] Applicant believes that another reference corresponds to U.S. Pat. No. 7,096,518 issued to Takenaga on Aug. 29, 2006, for a body part cleansing unit for toilet.
[0010] Applicant believes that another reference corresponds to U.S. Pat. No. 6,769,140 issued to Olivier on Aug. 3, 2004, for a toilet seat having a cleansing facility.
[0011] Applicant believes that another reference corresponds to U.S. Pat. No. 6,105,178 issued to Kurisaki et al. on Aug. 22, 2000, for a sanitary cleansing apparatus.
[0012] Applicant believes that another reference corresponds to U.S. Pat. No. 5,359,736 issued to Olivier on Nov. 1, 1994, for a spray means for a toilet pedestal.
[0013] Applicant believes that another reference corresponds to U.S. Pat. No. 5,319,811 issued to Haurion on Jun. 14, 1994, for a closet seat for a water closet as well as an apparatus for cleaning the posterior on a water closet having a seat.
[0014] Applicant believes that another reference corresponds to U.S. Pat. No. 4,628,548 issued to Kurosawa et al. on Dec. 16, 1986, for a device and method of moving and controlling the position of a slidable body such as used for body cleansing.
[0015] Applicant believes that another reference corresponds to U.S. Pat. No. 4,558,473 issued to Morikawa et al. on Dec. 17, 1985, for sanitary cleaning equipment.
[0016] Applicant believes that another reference corresponds to U.S. Pat. No. 3,247,524 issued to Umann on Apr. 26, 1966, for a hygienic apparatus for use on toilet bowls.
[0017] Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.
SUMMARY OF THE INVENTION
[0018] The instant invention is a combined automatic toilet self-cleaning and user hygienic system, having a housing assembly, an electrical system, a liquid matter system, a turbine assembly, and a manifold assembly. The manifold assembly has a first at least one cut out. The manifold assembly is partially housed within a manifold. The manifold assembly has ducting for air to flow originating from the turbine assembly. The manifold assembly further has a bidet for liquid matter to exit from the liquid matter system directed onto a user positioned on a toilet seat assembly. A toilet seat assembly has mounting brackets to mount onto the manifold assembly for rotary movement of the seat assembly. A cover assembly has a mounting frame to mount onto the manifold assembly. The cover assembly further has a rotating arm assembly.
[0019] It is therefore one of the main objects of the present invention to provide an auto cleaning toilet seat with anal cleaning device and blow dry that disinfects the toilet seat before use.
[0020] It is another object of this invention to provide an apparatus that washes and dries the anus and adjacent body opening areas of a user after using a toilet.
[0021] It is another object of this invention to provide an automatic toilet seat cleaning system, which embodiments can be used in circular and/or oval shape toilet bowls.
[0022] It is another object of this invention to provide an auto cleaning toilet seat with anal cleaning device and blow dry that is volumetrically efficient.
[0023] It is another object of this invention to provide an auto cleaning toilet seat with anal cleaning device and blow dry which is of a durable and reliable construction, inexpensive to manufacture and maintain while retaining its effectiveness.
[0024] Further objects of the invention will be brought out in the following part of the specification, wherein detailed description is for the purpose of fully disclosing the invention without placing limitations thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] With the above and other related objects in view, the invention consists in the details of construction and combination of parts as will be more fully understood from the following description, when read in conjunction with the accompanying drawings in which:
[0026] FIG. 1 is an isometric view of the preferred embodiment for the instant invention with its cover assembly in a closed position and installed onto a standard toilet.
[0027] FIG. 2 is a top plan view of the instant invention with its cover assembly in an open position and installed onto the standard toilet, whereby the tank of the toilet has been removed for illustrative purposes.
[0028] FIG. 3 is an exploded view of the instant invention.
[0029] FIG. 4 is an isometric view of the preferred embodiment for the instant invention with its cover assembly in an open position and installed onto the standard toilet having a circular toilet bowl.
[0030] FIG. 5 is a schematic cross section of the cover assembly, showing the liquid matter and air flowing.
[0031] FIG. 6 is a top view of a rotating arm assembly.
[0032] FIG. 7 is a bottom view of the rotating arm assembly.
[0033] FIG. 8A is a partially sectioned isometric view of the cover assembly in the closed position and showing an activated liquid matter duct assembly.
[0034] FIG. 8B is a partially sectioned isometric view of the cover assembly in the closed position and showing an activated air duct assembly.
[0035] FIG. 9A is a partially sectioned isometric view of the instant invention, showing a bidet extended and in use.
[0036] FIG. 9B is a partially sectioned isometric view of the instant 25 invention, showing the bidet retracted and manifold flaps In an open position, whereby forced air expels therefrom.
[0037] FIG. 10 is an isometric view of an alternate embodiment for the instant invention with its cover assembly in the closed position and installed onto an oval-shape toilet bowl.
[0038] 30 FIG. 11 is an isometric view of the alternate embodiment for the instant invention seen in FIG. 10 , with its cover assembly in the open position and installed onto the standard toilet having the oval shape toilet bowl.
[0039] FIG. 12 is a schematic diagram of the instant invention.
[0040] FIGS. 13A , 13 B, 13 C, 13 D, and 13 E are preferred timing charts of the instant invention.
[0041] FIGS. 14A , 14 B, 14 C, 14 D, and 14 E are alternate timing charts of the instant invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0042] It is evident that an invention such as the automatic toilet seat-cleaning system claimed in the present application is quite desirable because it disinfects the toilet seat before use. The claimed invention is also quite desirable because it provides an apparatus that washes and dries the anus and adjacent body opening areas of a user after using a toilet. In addition, the claimed invention can be used in circular and/or oval shape toilet bowls. Furthermore, the claimed invention is volumetrically efficient, of a durable and reliable construction, and it is inexpensive to manufacture and maintain while retaining its effectiveness.
[0043] Referring now to the drawings, the present invention is a combined automatic toilet self-cleaning and user hygienic system and is generally referred to with numeral 10 . It can be observed that it basically includes housing assembly 20 , electrical system 80 , liquid matter system 110 , turbine assemblies 100 and 200 , manifold assembly 220 , manifold 240 , toilet seat assembly 270 , and cover assembly 280 .
[0044] As seen in FIG. 1 , instant invention 10 is mounted to toilet 400 , which comprises tank 402 with flush button 404 , and toilet bowl 406 . Housing assembly 20 comprises bridge 22 connecting tower assemblies 30 and 130 cooperatively mounted at lateral sides of toilet 400 . Bridge 22 is preferably positioned behind a base of toilet bowl 406 .
[0045] As best seen in FIG. 2 , tower assembly 30 comprises lateral walls 32 and 34 , rear wall 36 , front wall 38 , base switch housing 42 , top wall 44 , base 46 as seen in FIG. 1 , and top switch housing 50 mounted onto top wall 44 . Similarly, tower assembly 130 comprises lateral walls 132 and 134 , rear wall 136 , front wall 138 , pressure regulator 142 , top wall 144 , base 146 as seen in FIG. 1 , and top regulator housing 150 mounted onto top wall 144 .
[0046] As seen in FIG. 3 , front wall 38 of tower assembly 30 has front cover panel 40 removably mounted to cutout 48 . Conduit 52 extends upwardly from top switch housing 50 . Front wall 138 of tower assembly 130 has front cover panel 140 removably mounted to cutout 148 . Conduit 152 extends upwardly from top regulator housing 150 .
[0047] Electrical system 80 comprises control box 82 with switches 84 and 86 disposed at base switch housing 42 , and switches 88 and 90 disposed at top switch housing 50 . In a preferred embodiment, screen 92 is positioned at top switch housing 50 and functions to give a status of instant invention 10 . Electrical system 80 further comprises electrical wiring 94 , seen in FIG. 12 , electrical valves 96 and impeller pump 98 . Pressure regulator 142 is connected to impeller pump 98 .
[0048] Pressure regulator 142 functions to regulate liquid matter LM pressure exiting bidet base 118 having telescopic section 120 , and specifically bidet 122 . Such liquid matter LM may be, but is not limited to, water, water combined with other matter such as a chemical, a chemical solution, and/or a chemical solution comprising a disinfectant as an example. The chemical, chemical solution, and/or chemical solution comprising a disinfectant may be of gas, liquid, semi-liquid, semi-solid, or solid matter.
[0049] Turbine assembly 100 is housed within tower assembly 30 and comprises housing 102 , motor housing 104 and outlet 106 . Outlet 106 connects to conduct 52 . Similarly, turbine assembly 200 is housed within tower assembly 130 and comprises housing 202 , motor housing 204 and outlet 206 that connects to conduit 152 .
[0050] Liquid matter system 110 includes disinfectant container 112 housed within tower assembly 30 , connecting tube 114 , and bidet base 118 having telescopic section 120 and bidet 122 at its distal end. Liquid matter system 110 further includes line 116 from a water source, which is best seen in FIG. 12 .
[0051] As also seen in FIG. 3 , manifold assembly 220 has wall 222 with ends 224 and 226 , cutouts 228 and 232 , and central cutout 230 . Manifold assembly 220 further comprises air ducts 234 and 236 that mount to conduits 52 and 152 of top switch housing 50 and top regulator housing 150 respectively. Connecting tube 114 goes through manifold assembly 220 . Bidet base 118 with telescopic section 120 is partially housed within manifold assembly 220 and protrudes through central cutout 230 .
[0052] Manifold 240 is mounted with mounting posts 250 passing through standard openings in toilet bowl 406 used for mounting of traditional toilet seats. Manifold 240 comprises housing 242 with ends 244 and 246 . Manifold flaps 248 are cooperatively disposed at a forward section of manifold 240 . Manifold flaps 248 have spring-loaded hinges, not seen. Tubular cutout 252 is also at the forward section of manifold 240 between manifold flaps 248 .
[0053] Toilet seat assembly 270 has mounting brackets 272 and inner edge 274 .
[0054] Mounting brackets 272 mount to ends 244 and 246 of manifold 240 . Mounting frame 292 mounts to mounting brackets 272 . It is noted that manifold assembly 220 passes through manifold 240 , mounting brackets 272 , and mounting frame 292 . Proximal ends of air ducts 234 and 236 are mounted to mounting frame 292 , which in turn are next to ends 224 and 226 of manifold assembly 220 . Bidet base 118 is positioned through central cutout 230 of manifold assembly 220 , and through an opening of manifold 240 , not shown, to be cooperatively disposed at tubular cutout 252 .
[0055] It is noted that manifold assembly 220 , manifold 240 , mounting brackets 272 , and mounting frame 292 are on a same axis.
[0056] As also seen in FIG. 3 , manifold assembly 220 has wall 222 with ends 224 and 226 , cutouts 228 and 232 , and central cutout 230 . Manifold assembly 220 further comprises air ducts 234 and 236 that mount to conduits 52 and 152 of top switch housing 50 and top regulator housing 150 respectively. Connecting tube 114 goes through manifold assembly 220 . Bidet base 118 with telescopic section 120 is partially housed within manifold assembly 220 and protrudes through central cutout 230 .
[0057] Manifold 240 is mounted with mounting posts 250 passing through standard openings in toilet bowl 406 used for mounting of traditional toilet seats. Manifold 240 comprises housing 242 with ends 244 and 246 . Manifold flaps 248 are cooperatively disposed at a forward section of manifold 240 . Manifold flaps 248 have spring- loaded hinges, not seen. Tubular cutout 252 is also at the forward section of manifold 240 between manifold flaps 248 .
[0058] Toilet seat assembly 270 has mounting brackets 272 and inner edge 274 .
[0059] Mounting brackets 272 mount to ends 244 and 246 of manifold 240 . Mounting frame 292 mounts to mounting brackets 272 . It is noted that manifold assembly 220 passes through manifold 240 , mounting brackets 272 , and mounting frame 292 . Proximal ends of air ducts 234 and 236 are mounted to mounting frame 292 , which in turn are next to ends 224 and 226 of manifold assembly 220 . Bidet base 118 is positioned through central cutout 230 of manifold assembly 220 , and through an opening of manifold 240 , not shown, to be cooperatively disposed at tubular cutout 252 .
[0060] It is noted that manifold assembly 220 , manifold 240 , mounting brackets 272 , and mounting frame 292 are on a same axis. As seen in FIGS. 4 and 5 , cover assembly 280 comprises exterior wall 282 , best seen in FIG. 1 , sidewall 284 with edge 286 , interior wall 288 , structural wall 290 , and mounting frame 292 . Sidewall 284 fits around toilet seat assembly 270 to force liquid matter to flow into toilet bowl 406 . As best seen in FIG. 5 , cover assembly 280 also has entry port 294 to connecting tube 114 as an access for liquid matter LM from liquid matter system 110 . Entry port 294 extends to channel 296 having holes 298 extending perpendicularly therefrom and hole 299 . Alignment assembly 300 , having threaded neck 302 , secures into hole 299 . Spacer 304 keeps rotating arm assembly 320 in place and spaced apart from alignment assembly 300 . Spacer 304 is made out of a self-lubricated material, preferably, to facilitate the free movement of rotating arm assembly 320 . In an alternate embodiment, neck 302 is not threaded and is forced into hole 298 . When cover assembly is in the closed position, alignment assembly 300 aligns interiorly to inner edge 274 of toilet seat assembly 270 leaving a space for liquid matter LM to go through. As seen in FIGS. 5 , 6 , and 7 , cover assembly 280 has mounting frame 292 to mount onto manifold assembly 220 . Cover assembly 280 further comprises rotating arm assembly 320 . Rotating arm assembly 320 has at least one cutout 344 for air A to flow originating from turbine assemblies 100 and 200 . Rotating arm assembly 320 further has at least one cutout 364 for liquid matter LM to exit therefrom that is directed onto toilet seat assembly 270 in a manner so as to provide cleaning of toilet seat assembly 270 . As best seen in FIGS. 5 and 6 , a section of exterior wall 282 and structural walls 290 define channel 289 .
[0061] More specifically, rotating arm assembly 320 further has hub 322 . Hub 322 fits into interior walls of cover assembly 280 , and specifically interior wall 288 and structural walls 290 . Rotating arm assembly 320 also has bridge 326 within hub 322 and o-ring 328 , or a similar type of sealing member. Bridge 326 connects to liquid matter duct assembly 360 . Extending from hub 322 is at least one arm 330 having end 332 . In a preferred embodiment, hub 322 has arms 330 extending in opposite directions therefrom. Each arm 330 comprises air duct assembly 340 and liquid matter duct assembly 360 . Air duct assembly 340 has air ducts 342 comprising at least one cutout 344 for air A to flow originating from turbine assemblies 100 and 200 . Liquid matter duct assembly 360 has liquid matter ducts 362 comprising at least one cutout 364 for liquid matter LM to exit therefrom.
[0062] As seen in FIGS. 8A and 8B , cover assembly 280 has been partially cross-sectioned to show how interior parts work. It is noted that when cover assembly 280 is closed, cutouts 228 and channel 289 are aligned thus permitting air A flowing from turbine assemblies 100 and 200 to flow through air duct assembly 340 . Also, it is noted that side wall 284 positions around an external edge of toilet seat assembly 270 and alignment assembly 300 cooperatively fits onto inner edge 274 , resting upon toilet seat assembly 270 in a way that a there is a clearance between alignment assembly 300 and inner edge 274 at front and sides. However, a rear portion of alignment assembly 300 snugly fits to a front section of manifold 240 , thus preventing manifold flaps 248 from opening when cover assembly 280 is closed.
[0063] In operation, liquid matter duct assembly 360 is activated with switch 84 or 88 , whereby liquid matter LM is delivered through cutouts 364 for a predetermined period of time on to toilet seat assembly 270 . The disposition of sidewall 284 and alignment assembly 300 forces the delivered liquid matter LM to be directed inside toilet bowl 406 . Once the cycle above has finished a displacing and drying cycle starts. Air A flowing from turbine assemblies 100 and 200 is directed through air ducts 234 and 236 , cutouts 228 and 232 , and then channel 289 into air duct assembly 340 , exiting through cutouts 344 to displace and/or dry the liquid matter LM from the surface of toilet seat assembly 270 . Instant invention 10 is then clean, sanitized, and ready for use by a user
[0064] As seen in FIGS. 9A and 9B , once a user uses toilet 400 , especially upon voiding, switch 86 or 90 is pressed to activate an anal cleaning cycle. Impeller pump 98 causes liquid matter LM to be expelled through bidet 122 for a predetermined period of time. The user can regulate the pressure of the liquid matter LM exiting bidet 122 by actuating pressure regulator 142 . Liquid matter LM pressure causes telescopic section 120 to extend from bidet base 118 . When the anal cleaning cycle ends, telescopic section 120 retracts back in to bidet base 118 and the anal drying cycle starts. Since cover assembly 280 is in an open position, channel 289 is covered by wall 222 of manifold assembly 220 . Therefore, air A flowing from turbine assemblies 100 and 200 forces manifold flaps 248 to open. Air A flowing through manifold flaps 248 is directed to the user's anal area for a predetermined period of time. As seen in FIGS. 10 and 11 , cover assembly 280 may comprise elongated protrusions 310 as an alternate embodiment. Elongated protrusions 310 are best utilized when toilet bowl 406 has a more oval shape as compared to a more circular shape as illustrated in FIG. 4 . In operation, elongated protrusions 310 receive ends 332 of arms 330 as rotating arm assembly rotates therein.
[0065] Seen in FIG. 12 is a schematic diagram of the connections for instant invention 10 . Water enters from a water source through line 116 , having a one-way valve, flows to impeller pump 98 . Liquid matter LM flow is selectively directed by electrical valves 96 ; either to liquid matter duct assembly 360 , along with a predetermined amount of disinfectant from disinfectant container 112 , or to bidet 122 with a pressure that user determines using pressure regulator 142 .
[0066] Electrical wiring supplies electrical power to control box 82 , which in turn is connected to turbine assemblies 100 and 200 , impeller pump 98 , and electrical valves 96 . Retention valves can be conveniently disposed to control the direction of the water flow.
[0067] FIGS. 13A , 13 B, 13 C, 13 D and 13 E represent timing charts showing preferred dispositions and states of the components of instant invention 10 in a period of time as follows:
[0068] 1. Period of time AB: Seat disinfectant cycle:
[0069] FIG. 13A : Cover assembly 280 is in a closed position.
[0070] FIG. 13B : Liquid matter LM is delivered through cutouts 364 of liquid matter duct assembly 360 and onto toilet seat assembly 270 .
[0071] FIG. 13C : Air A from turbine assemblies 100 and 200 to air duct assembly 340 is OFF.
[0072] FIG. 13D : Water flow from impeller pump 98 to bidet 122 s OFF.
[0073] FIG. 13E : Air A flow from turbine assemblies 100 and 200 to manifold flaps 248 is OFF.
[0074] 2. Period of time BC: Seat drying cycle starts:
[0075] FIG. 13A : Cover assembly 280 is in a closed position.
[0076] FIG. 13B : Liquid matter duct assembly 360 is OFF.
[0077] FIG. 13C : Air A from turbine assemblies 100 and 200 to air duct assembly 340 is ON. Air A flowing from turbine assemblies 100 and 200 is directed through air ducts 234 and 236 , cutouts 228 and 232 , channel 289 into air duct assembly 340 , exiting through cutouts 344 to displace and/or dry the liquid matter LM from toilet seat assembly 270 .
[0078] FIG. 13D : Water from impeller pump 98 to bidet 122 is OFF.
[0079] FIG. 13E : Air A flowing from turbine assemblies 100 and 200 to manifold flaps 248 is OFF.
[0080] 3. Period of time CD: Anal cleaning cycle:
[0081] FIG. 13A : Cover assembly 280 is in an open position.
[0082] FIG. 13B : Liquid matter duct assembly 360 is OFF.
[0083] FIG. 13C : Air A flow from turbine assemblies 100 and 200 to air duct assembly 340 is OFF.
[0084] FIG. 13D : Water flow from impeller pump 98 to bidet 122 is ON. Water flowing from impeller pump 98 is expelled through bidet 122 . Liquid matter LM pressure makes telescopic section 120 protrudes from bidet base 118 .
[0085] FIG. 13E : Air A flow from turbine assemblies 100 and 200 to manifold flaps 248 is OFF.
[0086] 4. Period of time DE: Anal area drying cycle:
[0087] FIG. 13A : Cover assembly 280 is in an open position.
[0088] FIG. 13B : Liquid matter duct assembly 360 is OFF.
[0089] FIG. 13C : Air A from turbine assemblies 100 and 200 to air duct assembly 340 is OFF.
[0090] FIG. 13D : Water flow from impeller pump 98 to bidet 122 is OFF.
[0091] FIG. 13E : Air A flow from turbine assemblies 100 and 200 to manifold flaps 248 is ON. Air
[0092] A flowing from turbine assemblies 100 and 200 forces manifold flaps 248 to open. Air A flowing out through manifold flaps 248 is directed to the user's anal area.
[0093] FIGS. 14A , 14 B, 14 C, 14 D and 14 E represent timing charts showing alternate dispositions and states of the components of instant invention 10 in a period of time as follows:
[0094] 1. Period of time AB: Seat disinfectant cycle:
[0095] FIG. 14A : Cover assembly 280 is in a closed position.
[0096] FIG. 14B : Liquid matter LM is delivered through cutouts 364 of liquid matter duct assembly 360 and onto toilet seat assembly 270 .
[0097] FIG. 14C : Air A from turbine assemblies 100 and 200 to air duct assembly 340 is ON. Air A flowing from turbine assemblies 100 and 200 is directed through air ducts 234 and 236 , cutouts 228 and 232 , channel 289 into air duct assembly 340 , exiting through cutouts 344 to displace and/or dry the liquid matter LM from toilet seat assembly 270 .
[0098] FIG. 14D : Water flow from impeller pump 98 to bidet 122 is OFF.
[0099] FIG. 14E : Air A flow from turbine assemblies 100 and 200 to manifold flaps 248 is OFF.
[0100] 2. Period of time BC: Seat drying cycle starts:
[0101] FIG. 14A : Cover assembly 280 is in a closed position.
[0102] FIG. 14B : Liquid matter duct assembly 360 is OFF.
[0103] FIG. 14C : Air A from turbine assemblies 100 and 200 to air duct assembly 340 is ON. Air A flowing from turbine assemblies 100 and 200 is directed through air ducts 234 and 236 , cutouts 228 and 232 , channel 289 into air duct assembly 340 , exiting through cutouts 344 to displace and/or dry the liquid matter LM from toilet seat assembly 270 .
[0104] FIG. 14D : Water from impeller pump 98 to bidet 122 is OFF.
[0105] FIG. 14E : Air A flowing from turbine assemblies 100 and 200 to manifold flaps 248 is OFF.
[0106] 3. Period of time CD: Anal cleaning cycle: FIG. 14A : Cover assembly 280 is in an open position.
[0107] FIG. 14B : Liquid matter duct assembly 360 is OFF.
[0108] FIG. 14C : Air A flow from turbine assemblies 100 and 200 to air duct assembly 340 is OFF.
[0109] FIG. 14D : Water flow from impeller pump 98 to bidet 122 is ON. Water flowing from impeller pump 98 is expelled through bidet 122 . Liquid matter LM pressure makes telescopic section 120 protrudes from bidet base 118 .
[0110] FIG. 14E : Air A flow from turbine assemblies 100 and 200 to manifold flaps 248 is OFF.
[0111] 4. Period of time DE: Anal area drying cycle:
[0112] FIG. 14A : Cover assembly 280 is in an open position.
[0113] FIG. 14B : Liquid matter duct assembly 360 is OFF.
[0114] FIG. 14C : Air A from turbine assemblies 100 and 200 to air duct assembly 340 is OFF.
[0115] FIG. 14D : Water flow from impeller pump 98 to bidet 122 is OFF.
[0116] FIG. 14E : Air A flow from turbine assemblies 100 and 200 to manifold flaps 248 is ON. Air
[0117] A flowing from turbine assemblies 100 and 200 forces manifold flaps 248 to open. Air A flowing out through manifold flaps 248 is directed to the user's anal area.
[0118] The foregoing description conveys the best understanding of the objectives and advantages of the present invention. Different embodiments may be made of the inventive concept of this invention. It is to be understood that all matter disclosed herein is to be interpreted merely as illustrative, and not in a limiting sense.
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A toilet seat cover assembly that has a cover shaped to fit over a toilet seat, the cover including internal side walls and an arm assembly disposed within the cover, the arm assembly including at least one arm that radially spans from an axis of rotation, defines a path of rotation, has a proximal end and a distal end, the distal end defining a discontinuity between the distal end and the internal side walls such that it is operable to move freely of the internal side walls, and defines a first plurality of cutouts fluidly coupled to a liquid source and sized to discharge liquid matter over the toilet seat.
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The present invention relates to a dispensing container for storing and dispensing liquids, and more specifically, relates to the pump dispenser for storing and dispensing samples and other small volumes of liquid from a compact container.
BACKGROUND OF THE INVENTION
It is often desirable to dispense small quantities of liquid from a disposable container. For example, in the fragrance industry, it is desirable to provide sample products for testing of perfume by potential customers. In the fragrance industry, samples are often contained in vials that are broken open or plastic sealed packets that are torn open to dispense the perfume. It is widely recognized that in order for the potential customer to fully appreciate the perfume, the perfume should be dispensed in a mist, preferably through a pump dispenser of the type that is used on bottles of perfume. In order to produce a package suitable for samples for perfume, the package should be compact, inexpensive to produce, and relatively inexpensive so that it is disposable Further, it would be desirable to provide dispensing through an atomizing pump so that the consumer can ascertain the essence of the perfume when it is atomized during application.
One prior art sample pump dispenser is disclosed in U.S. Pat. No. 5,102,018 issued Apr. 7, 1992. This pump dispenser comprises a conventional pump that is sealed with respect to a container by a conventional compressed gasket seal. The seal is held in a place by a multi-part sealing mechanism. This design has several disadvantages including the cost and manufacturing problems associated with multiple parts to be manufactured and assembled, and an awkward external appearance due to the structure needed to accommodate the multiple parts.
It is an object of the present invention to provide a pump dispenser that has the advantages of being disposable, made from very few parts, and easily assembled. The further object of the invention is to provide a sample pump dispenser that provides an excellent liquid seal between the pump and the reservoir containing the liquid. It is a further object of the invention to provide a pump dispenser wherein the exterior appearance of the reservoir is simple and elegant, and has a clean, unbroken silhouette, which is important when a dispenser is used for consumer sampling of products such as fragrances, as well as in other industries wherein the appearance of the container is important.
SUMMARY OF THE INVENTION
In accordance with the present invention a dispensing container for storing and dispensing liquid such as perfume, medicine, and the like is disclosed. The dispensing container includes a reservoir for the liquid and the reservoir includes an opening at the top thereof and a tubular package between the opening and the reservoir. In a preferred form of the invention, the reservoir comprises a cylindrical tube having the opening at one end and which is closed at the other end.
A conventional dispenser is utilized such as a pump of the type described in U.S. Pat. No. 4,606,479 issued Aug. 19, 1986 and U.S. patent application No. 694,418 filed May 1, 1991, or other conventional pump assemblies for dispensing liquid.
In order to provide a seal between the pump assembly and the reservoir, the sealing collar is provided. The collar comprises a resilient deformable polymeric material which provides a seal between the collar and the reservoir. The sealing collar has a frustoconical outer wall separated from a main body of the sealing collar. The top of the outer wall has a diameter which is greater than the diameter of the bottom of the wall to provide a taper angle of the frustoconical outer wall. The outer wall is deformable to permit the wall to flex radially inwardly.
The tubular passage of the reservoir has an interior wall that has a recess sized to receive the outer wall of the collar. The recess has a floor for retaining the bottom of the outer wall of the collar against vertical downward movement, and at a ledge for retaining the top of the outer wall of the collar against vertical upward movement.
The tubular passage has a diameter at the upper ledge of the recess that is smaller than the diameter of the top of the sealing collar. After liquid such as perfume or other dispensable liquid is placed in the reservoir, the sealing collar and pump assembly are inserted through the opening from above. During insertion, the outer wall of the sealing collar flexes radially inwardly as it passes the ledge. Once the top of the frustoconical wall passes the ledge it snaps radially outwardly into contact with the sidewall of the recess to form a liquid seal between the outer wall and the sidewall of the recess.
In accordance with one aspect of the invention, the dispensing container consists of only two subassemblies: (1) the reservoir and (2) the sealing collar and the pump assembly. Preferably, the reservoir consists of a polymeric material which is formed in a single integral part. Also, preferably, the sealing collar consists of a polymeric material which is formed in a single integral part. The pump is drawn from a variety of conventionally manufactured pump assemblies that are readily available. Thus, a dispensing pump and container in accordance with this aspect of the invention has a unique advantage of utilizing only two subassemblies to provide a dispensing pump and container which is easily manufactured and assembled. Further, the unique manner in which the sealing collar engages and seals with the tubular passage of the reservoir provides for an aesthetically pleasing external appearance wherein the dispenser has a clean, uncluttered silhouette.
In accordance with another aspect of the invention, the conventional pump assembly has a cylindrical actuator button from which liquid is dispensed. The button has a top surface for application of finger pressure. The actuator button has a diameter that is slightly less than the diameter than the opening of the reservoir. Thus, the actuator button is movable between a rest position downwardly through a pump stroke wherein the actuator button moves within the tubular package of the reservoir. This provides the advantage that the pump mechanism and the sealing collar is located internal of the actuator button and the reservoir. Thus, only the actuator button and the outer surface of the reservoir are visible by a person using the dispenser.
Other advantages of a dispensing container in accordance with the present invention will be apparent from the detailed description of the invention which follows.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the dispensing pump and container in accordance with the present invention;
FIG. 2 is a partial sectional view through the reservoir shown in FIG. 1 and through a sealing collar shown in FIGS. 3 and 4;
FIG. 3 is a perspective view of the sealing collar shown in FIG. 2;
FIG. 4 is a sectional view of the sealing collar along the lines 4--4 of FIG. 3;
FIG. 5 is a perspective partial sectional view of the inside of the reservoir with the recess shown in detail; and,
FIG. 6 is an expanded sectional view along the lines 6--6 of FIG. 5.
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIGS. 1 and 2, a dispensing pump and container in accordance with the present invention is shown. The dispensing pump includes a reservoir 10, a sealing collar 12, and a conventional pump assembly 14 having an actuator button 16.
Referring to FIGS. 1, 2, 5 and 6, the reservoir 10 includes an opening 18 for receiving the sealing collar 12 and the pump assembly 14. A tubular passage 20 extends between the opening 18 and the reservoir 22 which contains the liquid to be dispensed. In accordance with a preferred aspect of the invention, the reservoir comprises a cylinder that includes opening 18 at the top thereof and a bottom 24 that closes the reservoir. The exterior surface of reservoir 10 preferably comprises a smooth unbroken finish which provides an aesthetically pleasing dispensing container.
Referring in particular to FIGS. 3 and 4, the sealing collar includes a main body 26 having a generally cylindrical peripheral wall 28. Peripheral wall 28 has a bottom 30 that is attached to the bottom 32 of outer wall 34. The outer wall is frustoconical in shape. The outer wall has a top 36 that has a diameter 38 which is greater than the diameter 40 of the bottom 32 of the outer wall 34 to provide the desired frustoconical taper. The outer wall 34 preferably has a predetermined thickness that is deformable to permit the wall 34 to flex radially inwardly.
In accordance with a preferred aspect of the invention, the sealing collar is formed from a flexible polymeric material in a single integral part. More preferably, the part is molded from polyethylene.
As shown in FIG. 2, the pump assembly 14 is secured to the sealing collar 12 in a conventional fashion. The pump can be secured to the sealing collar in a number of different fashions, one of which is disclosed in U.S. Pat. No. 5,108,013 issued Apr. 28, 1992 which is incorporated by reference herein. The sealing collar 12 and pump assembly 14 are assembled and inserted through opening 18 in the reservoir to secure the pump assembly 14 in place and to seal the pump assembly with respect to the tubular passage of the reservoir.
Referring to FIGS. 5 and 6, recess 42 for receiving the frustoconical outer wall 34 of the sealing collar 12 will now be described. Recess 42 has a floor 44 for retaining the bottom 32 of the sealing collar 12 against vertical downward movement. More specifically, the diameter 46 of the tubular passage 20 is less than the diameter 62 of the recess 42, and is also less than the outer diameter 40 of the sealing collar 12. Thus, when the sealing collar 12 is inserted into the tubular passage 20, it comes to rest against floor 44, and can proceed no further into the tubular passage 20.
The recess 42 also has a ledge 48 for retaining the top 36 of the outer wall 34 against vertical upward movement. The diameter 50 of the tubular passage just above the ledge 48 is less than the diameter 66 of the recess 42, and is also less than the diameter 38 of the top 36 of the sealing collar 12. When the sealing collar 12 is inserted into the tubular passage 20, the collar outer wall 34 flexes radially inwardly as it passes the ledge 48 and then moves radially outwardly once it has passed the ledge 48 to position the outer wall 34 adjacent the circumferential sidewall 52 of the recess. The outer wall 34 of the sealing collar 12 forms liquid seal with the circumferential sidewall 52 to retain liquid in the reservoir 10.
In accordance with one aspect of the invention, the outer wall 34 of the sealing collar 12 is frustoconical and has a taper angle 54 of between about 5 to about 10 degrees with respect to vertical. The circumferential sidewall 52 of the recess also has a taper angle 56 with respect to vertical, such taper angle being in the range between about 0.5 and about 3 degrees. The taper angle 54 of the sealing collar should be greater than a taper angle 56 of the recess sidewall Thus, when the sealing collar 12 is seated in the recess 42, the pressure between the sidewall 52 and the outer wall 34 increases along the height of the outer wall 34 from the bottom 30 to the top 36.
In addition, the outer wall 34 of the sealing collar 12 has a height 58 that is slightly less than the height 60 of the recess 42 to permit a snug fit of the outer wall 34 into the recess 42.
The floor 44 of the recess 42 has a diameter 62 which is preferably greater than the diameter 40 of the bottom 30 the sealing collar 12. Thus, when the sealing collar 12 is positioned on floor 44, there is a close fit between the sidewall 52 and the outer wall 32 at the bottom thereof. The top diameter 66 of the recess 42 at the ledge 48 is smaller than the top diameter 38 of the sealing collar 12 to provide an interference fit and an annular area of contact as best illustrated in FIG. 2.
In accordance with another aspect of the invention, the circumferential sidewall 52 of the recess 42 has a plurality of spaced apart ridges 68, 70 and 72. Each ridge includes a sharpened edge 73 that cuts into the outer wall 34 of the sealing collar 12. Because the sealing collar outer 34 wall has a greater taper angle than the taper angle of the circumferential sidewall 52 of the recess 42, the pressure of the outer wall 34 against ridge 68 is greater than the pressure of the outer wall 34 against ridge 70. Thus, ridge 68 digs further into the surface of the outer wall 34 than ridge 70. Likewise, ridge 70 digs further into the outer wall 34 than does ridge 72. The deformation of the outer wall 34 of the sealing collar by the ridges 68, 70, 72 provides a liquid seal that extends around the circumference of the ridges. In particular, a first seal is provided by ridge 72, a second seal is provided by ridge 70, and a third seal is provided by ridge 68. The triple seal is effective to minimize any leakage of liquid from the reservoir 10.
In accordance with one aspect of the invention, the dispensing container has two subassemblies for ease of manufacture and for reduction in costs of parts. More specifically, the first subassembly is the reservoir 10, the second subassembly is the sealing collar 12 and the pump assembly 14.
The pump assembly 14 with the sealing collar 12 is assembled with the actuator 16 in advance. The reservoir 10 is then separately filled, and the sealing collar 12 is fitted into the reservoir 10 until the outer wall 34 is snap fitted into the recess 42 in reservoir 10.
In accordance with one aspect of the invention, the actuator button 16 has a generally cylindrical shape and has a diameter 74 that is slightly less than the diameter of opening 18. Thus, as shown in FIG. 1, once the dispensing pump and container are assembled, one only sees two parts: the reservoir and the actuator button. The actuator button is movable between a rest position downwardly through a pump stroke wherein the actuator button moves internal to the reservoir. Thus, a very simple outward appearance is provided without an aesthetically detracting pump/reservoir fastener or other break line that is visible to the user.
It should be understood that although specific embodiments of the invention have been described herein in detail, such description is for purposes of illustration only and modifications may be made thereto by those skilled in the art within the scope of the invention.
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A dispensing container for storing and dispensing liquid such as perfume, medicine and the like is disclosed. The dispensing container contains a reservoir for the liquid, a pump for dispensing the liquid and a sealing collar for sealing the pump with respect to the reservoir.
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REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 10/413,755, filed Apr. 14, 2003, now U.S. Pat. No. ______, issued ______, the contents of which is herein incorporated by reference.
FIELD OF THE INVENTION
[0002] This invention relates to the isolation and production of cancerous disease modifying antibodies (CDMAB) and to the use of these CDMAB in therapeutic and diagnostic processes, optionally in combination with one or more chemotherapeutic agents. The invention further relates to binding assays, which utilize the CDMAB of the instant invention.
BACKGROUND OF THE INVENTION
[0003] Each individual who presents with cancer is unique and has a cancer that is as different from other cancers as that person's identity. Despite this, current therapy treats all patients with the same type of cancer, at the same stage, in the same way. At least 30 percent of these patients will fail the first line of therapy, thus leading to further rounds of treatment and the increased probability of treatment failure, metastases, and ultimately, death. A superior approach to treatment would be the customization of therapy for the particular individual. The only current therapy that lends itself to customization is surgery. Chemotherapy and radiation treatment cannot be tailored to the patient, and surgery by itself, in most cases is inadequate for producing cures.
[0004] With the advent of monoclonal antibodies, the possibility of developing methods for customized therapy became more realistic since each antibody can be directed to a single epitope. Furthermore, it is possible to produce a combination of antibodies that are directed to the constellation of epitopes that uniquely define a particular individual's tumor.
[0005] Having recognized that a significant difference between cancerous and normal cells is that cancerous cells contain antigens that are specific to transformed cells, the scientific community has long held that monoclonal antibodies can be designed to specifically target transformed cells by binding specifically to these cancer antigens; thus giving rise to the belief that monoclonal antibodies can serve as “Magic Bullets” to eliminate cancer cells.
[0006] Monoclonal antibodies isolated in accordance with the teachings of the instantly disclosed invention have been shown to modify the cancerous disease process in a manner which is beneficial to the patient, for example by reducing the tumor burden, and will variously be referred to herein as cancerous disease modifying antibodies (CDMAB) or “anti-cancer” antibodies.
[0007] At the present time, the cancer patient usually has few options of treatment. The regimented approach to cancer therapy has produced improvements in global survival and morbidity rates. However, to the particular individual, these improved statistics do not necessarily correlate with an improvement in their personal situation.
[0008] Thus, if a methodology was put forth which enabled the practitioner to treat each tumor independently of other patients in the same cohort, this would permit the unique approach of tailoring therapy to just that one person. Such a course of therapy would, ideally, increase the rate of cures, and produce better outcomes, thereby satisfying a long-felt need.
[0009] Historically, the use of polyclonal antibodies has been used with limited success in the treatment of human cancers. Lymphomas and leukemias have been treated with human plasma, but there were few prolonged remissions or responses. Furthermore, there was a lack of reproducibility and no additional benefit compared to chemotherapy. Solid tumors such as breast cancers, melanomas and renal cell carcinomas have also been treated with human blood, chimpanzee serum, human plasma and horse serum with correspondingly unpredictable and ineffective results.
[0010] There have been many clinical trials of monoclonal antibodies for solid tumors. In the 1980s there were at least 4 clinical trials for human breast cancer, which produced only 1 responder from at least 47 patients using antibodies against specific antigens or based on tissue selectivity. It was not until 1998 that there was a successful clinical trial using a humanized anti-Her2 antibody in combination with cisplatin. In this trial 37 patients were accessed for responses of which about a quarter had a partial response rate and another half had minor or stable disease progression.
[0011] The clinical trials investigating colorectal cancer involve antibodies against both glycoprotein and glycolipid targets. Antibodies such as 17-1A, which has some specificity for adenocarcinomas, had undergone Phase 2 clinical trials in over 60 patients with only 1 patient having a partial response. In other trials, use of 17-1A produced only 1 complete response and 2 minor responses among 52 patients in protocols using additional cyclophosphamide. Other trials involving 17-1A yielded results that were similar. The use of a humanized murine monoclonal antibody initially approved for imaging also did not produce tumor regression. To date there has not been an antibody that has been effective for colorectal cancer. Likewise there have been equally poor results for lung, brain, ovarian, pancreatic, prostate, and stomach cancers. There has been some limited success in the use of an anti-GD3 monoclonal antibody for melanoma. Thus, it can be seen that despite successful small animal studies that are a prerequisite for human clinical trials, the antibodies that have been tested thus far, have been for the most part, ineffective.
[heading-0012] Prior Patents:
[0013] U.S. Pat. No. 5,750,102 discloses a process wherein cells from a patient's tumor are transfected with MHC genes, which may be cloned from cells or tissue from the patient. These transfected cells are then used to vaccinate the patient.
[0014] U.S. Pat. No. 4,861,581 discloses a process comprising the steps of obtaining monoclonal antibodies that are specific to an internal cellular component of neoplastic and normal cells of the mammal but not to external components, labeling the monoclonal antibody, contacting the labeled antibody with tissue of a mammal that has received therapy to kill neoplastic cells, and determining the effectiveness of therapy by measuring the binding of the labeled antibody to the internal cellular component of the degenerating neoplastic cells. In preparing antibodies directed to human intracellular antigens, the patentee recognizes that malignant cells represent a convenient source of such antigens.
[0015] U.S. Pat. No. 5,171,665 provides a novel antibody and method for its production. Specifically, the patent teaches formation of a monoclonal antibody which has the property of binding strongly to a protein antigen associated with human tumors, e.g. those of the colon and lung, while binding to normal cells to a much lesser degree.
[0016] U.S. Pat. No. 5,484,596 provides a method of cancer therapy comprising surgically removing tumor tissue from a human cancer patient, treating the tumor tissue to obtain tumor cells, irradiating the tumor cells to be viable but non-tumorigenic, and using these cells to prepare a vaccine for the patient capable of inhibiting recurrence of the primary tumor while simultaneously inhibiting metastases. The patent teaches the development of monoclonal antibodies which are reactive with surface antigens of tumor cells. As set forth at col. 4, lines 45 et seq., the patentees utilize autochthonous tumor cells in the development of monoclonal antibodies expressing active specific immunotherapy in human neoplasia.
[0017] U.S. Pat. No. 5,693,763 teaches a glycoprotein antigen characteristic of human carcinomas is not dependent upon the epithelial tissue of origin.
[0018] U.S. Pat. No. 5,783,186 is drawn to anti-Her2 antibodies, which induce apoptosis in Her2 expressing cells, hybridoma cell lines producing the antibodies, methods of treating cancer using the antibodies and pharmaceutical compositions including said antibodies.
[0019] U.S. Pat. No. 5,849,876 describes new hybridoma cell lines for the production of monoclonal antibodies to mucin antigens purified from tumor and non-tumor tissue sources.
[0020] U.S. Pat. No. 5,869,268 is drawn to a method for generating a human lymphocyte producing an antibody specific to a desired antigen, a method for producing a monoclonal antibody, as well as monoclonal antibodies produced by the method. The patent is particularly drawn to the production of an anti-HD human monoclonal antibody useful for the diagnosis and treatment of cancers.
[0021] U.S. Pat. No. 5,869,045 relates to antibodies, antibody fragments, antibody conjugates and single chain immunotoxins reactive with human carcinoma cells. The mechanism by which these antibodies function is two-fold, in that the molecules are reactive with cell membrane antigens present on the surface of human carcinomas, and further in that the antibodies have the ability to internalize within the carcinoma cells, subsequent to binding, making them especially useful for forming antibody-drug and antibody-toxin conjugates. In their unmodified form the antibodies also manifest cytotoxic properties at specific concentrations.
[0022] U.S. Pat. No. 5,780,033 discloses the use of autoantibodies for tumor therapy and prophylaxis. However, this antibody is an anti-nuclear autoantibody from an aged mammal. In this case, the autoantibody is said to be one type of natural antibody found in the immune system. Because the autoantibody comes from “an aged mammal”, there is no requirement that the autoantibody actually comes from the patient being treated. In addition the patent discloses natural and monoclonal anti-nuclear autoantibody from an aged mammal, and a hybridoma cell line producing a monoclonal anti-nuclear autoantibody.
SUMMARY OF THE INVENTION
[0023] The instant inventors have previously been awarded U.S. Pat. No. 6,180,357, entitled “Individualized Patient Specific Anti-Cancer Antibodies” directed to a process for selecting individually customized anti-cancer antibodies, which are useful in treating a cancerous disease. For the purpose of this document, the terms “antibody” and “monoclonal antibody” (mAb) may be used interchangeably and refer to intact immunoglobulins produced by hybridomas (e.g. murine or human), immunoconjugates and, as appropriate, immunoglobulin fragments and recombinant proteins derived from immunoglobulins, such as chimeric and humanized immunoglobulins, F(ab′) and F(ab′) 2 fragments, single-chain antibodies, recombinant immunoglobulin variable regions (Fv)s, fusion proteins etc. For the purpose of this document, the term “tissue sample” is understood to mean at least one cell or an aggregate of cells obtained from a mammal. It is well recognized in the art that some amino acid sequence can be varied in a polypeptide without significant effect on the structure or function of the protein. In the molecular rearrangement of antibodies, modifications in the nucleic or amino acid sequence of the backbone region can generally be tolerated. These include, but are not limited to, substitutions (preferred are conservative substitutions), deletions or additions. Furthermore, it is within the purview of this invention to conjugate standard chemotherapeutic modalities, e.g. radionuclides, with the CDMAB of the instant invention, thereby focusing the use of said chemotherapeutics. The CDMAB can also be conjugated to toxins, cytotoxic moieties, enzymes e.g. biotin conjugated enzymes, or hematogenous cells, thereby forming antibody conjugates.
[0024] This application utilizes the method for producing patient specific anti-cancer antibodies as taught in the '357 patent for isolating hybridoma cell lines which encode for cancerous disease modifying monoclonal antibodies. These antibodies can be made specifically for one tumor and thus make possible the customization of cancer therapy. Within the context of this application, anti-cancer antibodies having either cell-killing (cytotoxic) or cell-growth inhibiting (cytostatic) properties will hereafter be referred to as cytotoxic. These antibodies can be used in aid of staging and diagnosis of a cancer, and can be used to treat tumor metastases.
[0025] Using substantially the process of U.S. Pat. No. 6,180,357, the mouse monoclonal antibody 10A304.7 was obtained following immunization of mice with frozen single cell suspensions of the human HT-29 colon cancer cell line that had been grown as a solid tumor in SCID mice. These antibodies can be used in aid of staging and diagnosis of a cancer, and can be used to treat tumor metastases. The 10A304.7 antigen was expressed on the cell surface of a broad range of human cell lines from different tissue origins. The colon cancer cell line SW116, the breast cancer cell lines MDA-MB-231, MCF-7, the prostate cancer cell line PC-3 and the ovarian cancer cell line OVCAR-3 were the cancer cell lines tested that were susceptible to the cytotoxic effects of 10A304.7 demonstrated in application Ser. No. 10/413,755, filed Apr. 14, 2003, now U.S. Pat. No. ______, issued ______.
[0026] The result of 10A304.7 cytotoxic activity against breast cancer cells in tissue culture was further extended by establishing its anti-tumor activity in vivo. In an in vivo model of human breast cancer, the MDA-MB-231 cancer cells were implanted underneath the skin at the scruff of the neck of severe combined immunodeficient (SCID) mice, as they are incapable of rejecting the human tumor cells due to a lack of certain immune cells. Pre-clinical xenograft tumor models are considered valid predictors of therapeutic efficacy. Xenografts in mice grow as solid tumors developing stroma, central necrosis and neo-vasculature in the same manner as naturally occurring cancers. The mammary tumor cell line MDA-MB-231 has been evaluated as an in vivo xenograft model in immunodeficient mice. The successful engraftment or ‘take-rate’ of MDA-MB-231 tumors and the sensitivity of the tumors to standard chemotherapeutic agents have characterized them as suitable models. The MDA-MB-231 parental cell line and variants of the cell line have been used successfully in xenograft tumor models to evaluate a wide range of therapeutic agents that are now used as clinical chemotherapeutic agents.
[0027] 10A304.7 prevented tumor growth and reduced tumor burden in a in vivo model of human breast cancer. On day 56 post-implantation, 6 days after the last treatment dose, the mean tumor volume in the 10A304.7 treated group was 1 percent of the tumor volume in the isotype control treated group (p=0.0003, t-test). There were no clinical signs of toxicity throughout the study. Body weight measured at weekly intervals was a surrogate for health. There was no significant difference in body weight between the groups at the end of the treatment period (p=0.3512, t-test). Therefore 10A304.7 was well-tolerated and decreased the tumor burden in a breast cancer xenograft model.
[0028] In all, this invention teaches the use of the 10A304.7 antigen as a target for a therapeutic agent, that when administered can reduce the tumor burden of a cancer expressing the antigen in a mammal. This invention also teaches the use of CDMAB (10A304.7), and its derivatives, to target its antigen to reduce the tumor burden of a cancer expressing the antigen in a mammal. Furthermore, this invention also teaches the use of detecting the 10A304.7 antigen in cancerous cells that can be useful for the diagnosis, prediction of therapy, and prognosis of mammals bearing tumors that express this antigen.
[0029] The prospect of individualized anti-cancer treatment will bring about a change in the way a patient is managed. A likely clinical scenario is that a tumor sample is obtained at the time of presentation, and banked. From this sample, the tumor can be typed from a panel of pre-existing cancerous disease modifying antibodies. The patient will be conventionally staged but the available antibodies can be of use in further staging the patient. The patient can be treated immediately with the existing antibodies and/or a panel of antibodies specific to the tumor can be produced either using the methods outlined herein or through the use of phage display libraries in conjunction with the screening methods herein disclosed. All the antibodies generated will be added to the library of anti-cancer antibodies since there is a possibility that other tumors can bear some of the same epitopes as the one that is being treated. The antibodies produced according to this method may be useful to treat cancerous disease in any number of patients who have cancers that bind to these antibodies.
[0030] If a patient is refractory to the initial course of therapy or metastases develop, the process of generating specific antibodies to the tumor can be repeated for re-treatment. Furthermore, the anti-cancer antibodies can be conjugated to red blood cells obtained from that patient and re-infused for treatment of metastases. There have been few effective treatments for metastatic cancer and metastases usually portend a poor outcome resulting in death. However, metastatic cancers are usually well vascularized and the delivery of anti-cancer antibodies by red blood cells can have the effect of concentrating the antibodies at the site of the tumor. Even prior to metastases, most cancer cells are dependent on the host's blood supply for their survival and an anti-cancer antibody conjugated to red blood cells can be effective against in situ tumors as well. Alternatively, the antibodies may be conjugated to other hematogenous cells, e.g. lymphocytes, macrophages, monocytes, natural killer cells, etc.
[0031] There are five classes of antibodies and each is associated with a function that is conferred by its heavy chain. It is generally thought that cancer cell killing by naked antibodies are mediated either through antibody-dependent cell-mediated cytotoxicity (ADCC) or complement-dependent cytotoxicity (CDC). For example murine IgM and IgG2a antibodies can activate human complement by binding the C-1 component of the complement system thereby activating the classical pathway of complement activation which can lead to tumor lysis. For human antibodies, the most effective complement activating antibodies are generally IgM and IgG1. Murine antibodies of the IgG2a and IgG3 isotype are effective at recruiting cytotoxic cells that have Fc receptors which will lead to cell killing by monocytes, macrophages, granulocytes and certain lymphocytes. Human antibodies of both the IgG1 and IgG3 isotype mediate ADCC.
[0032] Another possible mechanism of antibody mediated cancer killing may be through the use of antibodies that function to catalyze the hydrolysis of various chemical bonds in the cell membrane and its associated glycoproteins or glycolipids, so-called catalytic antibodies.
[0033] There are two additional mechanisms of antibody mediated cancer cell killing which are more widely accepted. The first is the use of antibodies as a vaccine to induce the body to produce an immune response against the putative antigen that resides on the cancer cell. The second is the use of antibodies to target growth receptors and interfere with their function or to down regulate that receptor so that effectively its function is lost.
[0034] The clinical utility of a cancer drug is based on the benefit of the drug under an acceptable risk profile to the patient. In cancer therapy survival has generally been the most sought after benefit, however there are a number of other well-recognized benefits in addition to prolonging life. These other benefits, where treatment does not adversely affect survival, include symptom palliation, protection against adverse events, prolongation in time to recurrence or disease-free survival, and prolongation in time to progression. These criteria are generally accepted and regulatory bodies such as the U.S. Food and Drug Administration (F.D.A.) approve drugs that produce these benefits (Hirschfeld et al. Critical Reviews in Oncology/Hematolgy 42:137-143 2002). In addition to these criteria it is well recognized that there are other endpoints that may presage these types of benefits. In part, the accelerated approval process granted by the U.S. F.D.A. acknowledges that there are surrogates that will likely predict patient benefit. As of year-end (2003), there have been sixteen drugs approved under this process, and of these, four have gone on to full approval, i.e., follow-up studies have demonstrated direct patient benefit as predicted by surrogate endpoints. One important endpoint for determining drug effects in solid tumors is the assessment of tumor burden by measuring response to treatment (Therasse et al. Journal of the National Cancer Institute 92(3):205-216 2000). The clinical criteria (RECIST criteria) for such evaluation have been promulgated by Response Evaluation Criteria in Solid Tumors Working Group, a group of international experts in cancer. Drugs with a demonstrated effect on tumor burden, as shown by objective responses according to RECIST criteria, in comparison to the appropriate control group tend to, ultimately, produce direct patient benefit. In the pre-clinical setting tumor burden is generally more straightforward to assess and document. In that pre-clinical studies can be translated to the clinical setting, drugs that produce prolonged survival in pre-clinical models have the greatest anticipated clinical utility. Analogous to producing positive responses to clinical treatment, drugs that reduce tumor burden in the pre-clinical setting may also have significant direct impact on the disease. Although prolongation of survival is the most sought after clinical outcome from cancer drug treatment, there are other benefits that have clinical utility and it is clear that tumor burden reduction, which may correlate to a delay in disease progression, extended survival or both, can also lead to direct benefits and have clinical impact (Eckhardt et al. Developmental Therapeutics: Successes and Failures of Clinical Trial Designs of Targeted Compounds; ASCO Educational Book, 39 th Annual Meeting, 2003, pages 209-219).
[0035] Accordingly, it is an objective of the invention to utilize a method for producing CDMAB from cells derived from a particular individual which are cytotoxic with respect to cancer cells while simultaneously being relatively non-toxic to non-cancerous cells, in order to isolate hybridoma cell lines and the corresponding isolated monoclonal antibodies and antigen binding fragments thereof for which said hybridoma cell lines are encoded.
[0036] It is an additional objective of the invention to teach CDMAB and antigen binding fragments thereof.
[0037] It is a further objective of the instant invention to produce CDMAB whose cytotoxicity is mediated through ADCC.
[0038] It is yet an additional objective of the instant invention to produce CDMAB whose cytotoxicity is mediated through CDC.
[0039] It is still a further objective of the instant invention to produce CDMAB whose cytotoxicity is a function of their ability to catalyze hydrolysis of cellular chemical bonds.
[0040] A still further objective of the instant invention is to produce CDMAB which are useful in a binding assay for the diagnosis, prognosis, and monitoring of cancer.
[0041] Other objects and advantages of this invention will become apparent from the following description wherein are set forth, by way of illustration and example, certain embodiments of this invention.
BRIEF DESCRIPTION OF THE FIGURES
[0042] FIG. 1 . Representative FACS histograms of 10A304.7, isotype control and anti-EGFR antibodies directed against several cancer and non-cancer cell lines.
[0043] FIG. 2 . Effect of 10A304.7 on tumor growth in a MDA-MB-231 breast cancer model. The dashed line indicates the period during which the antibody was administered. Data points represent the mean+/−SEM.
[0044] FIG. 3 . Effect of 10A304.7 on body weight in a MDA-MB-231 breast cancer model. Data points represent the mean+/−SEM.
DETAILED DESCRIPTION OF THE INVENTION
EXAMPLE 1
[0045] As shown in Ser. No. 10/413,755, the hybridoma cell line 10A304.7 was deposited, in accordance with the Budapest Treaty, with the American Type Culture Collection, 10801 University Blvd., Manassas, Va. 20110-2209 on Mar. 19, 2003, under Accession Number PTA-5065. In accordance with 37 CFR 1.808, the depositors assure that all restrictions imposed on the availability to the public of the deposited materials will be irrevocably removed upon the granting of a patent.
[0046] 10A304.7 monoclonal antibody was produced by culturing the hybridoma in CL-1000 flasks (BD Biosciences, Oakville, ON) with collections and reseeding occurring twice/week and with purification according to standard antibody purification procedures with Protein G Sepharose 4 Fast Flow (Amersham Biosciences, Baie d'Urfé, QC).
[0047] As previously described in Ser. No. 10/413,755, 10A304.7 was compared to a number of both positive (anti-Fas (EOS9.1, IgM, kappa, 20 mg/mL, eBioscience, San Diego, Calif.), anti-Her2/neu (IgG1, kappa, 10 mg/mL, Inter Medico, Markham, ON), anti-EGFR (C225, IgG1, kappa, 5 mg/mL, Cedarlane, Homby, ON), Cycloheximide (100 mM, Sigma, Oakville, ON), and NaN 3 (0.1%, Sigma, Oakville, ON)) and negative (107.3 (anti-TNP, IgG1, kappa 20 mg/mL, BD Biosciences, Oakville, ON), MPC-11 (antigenic specificity unknown, kappa 20 mg/mL), IgG Buffer (2%)) controls in a cytotoxicity assay (Table 1). Breast cancer (MDA-MB-231 (MB-231), MCF-7), colon cancer (Caco-2, DLD-1, Lovo, HT-29, SW 116, SW620), ovarian cancer (OVCAR), pancreatic cancer (BxPC-3), prostate cancer (PC-3), and non-cancer (CCD 27sk, Hs888.Lu) cell lines were tested (all from the ATCC, Manassas, Va.). The Live/Dead cytotoxicity assay was obtained from Molecular Probes (Eugene, Oreg.). The assays were performed according to the manufacturer's instructions with the changes outlined below. Cells were plated before the assay at the predetermined appropriate density. After 2 days, 100 microliters of purified antibody was diluted into media, and then were transferred to the cell plates and incubated in a 5% CO 2 incubator for 5 days. The plate was then emptied by inverting and blotted dry. Room temperature DPBS containing MgCl 2 and CaCl 2 was dispensed into each well from a multichannel squeeze bottle, tapped three times, emptied by inversion and then blotted dry. 50 microliters of the fluorescent Live/Dead dye diluted in DPBS containing MgCl 2 and CaCl 2 was added to each well and incubated at 37° C. in a 5% CO 2 incubator for 30 minutes. The plates were read in a Perkin-Elmer HTS7000 fluorescence plate reader and the data was analyzed in Microsoft Excel and the results were tabulated in Table 1. The data represented an average of four experiments tested in triplicate and presented qualitatively in the following fashion: 4/4 experiments with 15% cytotoxicity above background (++++), 2/4 experiments with 15% cytotoxicity above background (+++), at least 2/4 experiments with 10-15% cytotoxicity above background (++), and at least 2/4 experiments with 8-10% cytotoxicity above background. Unmarked cells in Table 1 represented inconsistent or effects less than the threshold cytotoxicity. The 10A304.7 antibody produced 35% of the cytotoxic effect of the well-described anti-EGFR antibody C225, which induced 31% cytotoxicity in the SW1116 colon cell line. Further, 10A304.7 induced significantly higher cytotoxicity against other cancer cells, compared with C225, including the breast cancer cell lines MDA-MB-231 (111%) and MCF-7 (850%), the prostate cancer cell line PC-3 (375%), and the ovarian cancer cell line OVCAR (667%). Importantly, 10A304.7 did not produce cytotoxicity against a number of non-cancer cells such as CCD 27sk or Hs888.Lu, indicating that the antibody has functional specificity towards various cancer cells. The chemical cytotoxic agents induced their expected cytotoxicity while a number of other antibodies which were included for comparison also performed as expected given the limitations of biological cell assays.
TABLE 1 Colon Pancreas Breast Prostate Ovary Normal Cells Caco-2 DLD-1 Lovo HT-29 SW1116 SW620 BxPC-3 MB-231 MCF-7 PC-3 OVCAR CCD 27sk Hs888.Lu 10A304.7 (20 ++ ++ ++++ +++ ++++ μg/mL) Positive Controls Anti-Fas (20 ++ ++++ ++++ ++ ++++ μg/mL) Anti-Her2/neu (10 μg/mL) Anti-EGFR +++ ++++ ++++ + (c225, 5 μg/mL) Cycloheximide ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ ++++ (100 μM) Negative Controls IgG1 (107.3, + + + 20 μg/mL) IgG2b (MPC- + 11, 20 μg/mL) IgG Buffer (2%)
[0048] Also as previously described in Ser. No. 10/413,755, binding of 10A304.7 to the above-mentioned panel of cancer and normal cell lines was assessed by flow cytometry (FACS). Cells were prepared for FACS by initially washing the cell monolayer with DPBS (without Ca ++ and Mg ++ ). Cell dissociation buffer (INVITROGEN) was then used to dislodge the cells from their cell culture plates at 37° C. After centrifugation and collection the cells were resuspended in Dulbecco's phosphate buffered saline containing MgCl 2 , CaCl 2 and 25% fetal bovine serum at 4° C. (wash media) and counted, aliquoted to appropriate cell density, spun down to pellet the cells and resuspended in staining media (DPBS containing MgCl 2 , CaCl 2 and 2% fetal bovine serum) at 4° C. in the presence of test antibody (10A304.7) or control antibodies (isotype control, anti-EGF-R, or anti-Fas) at 20 micrograms/mL on ice for 30 minutes. Prior to the addition of Alexa Fluor 488-conjugated secondary antibody the cells were washed once with wash media. The Alexa Fluor 488-conjugated antibody in staining media was then added for 20 minutes. The cells were then washed for the final time and resuspended in staining media containing 1 microgram/mL propidium iodide. Flow cytometric acquisition of the cells was assessed by running samples on a FACScan using the CellQuest software (BD Biosciences). The forward (FSC) and side scatter (SSC) of the cells were set by adjusting the voltage and amplitude gains on the FSC and SSC detectors. The detectors for the three fluorescence channels (FL1, FL2, and FL3) were adjusted by running cells stained with purified isotype control antibody followed by Alexa Fluor 488-conjugated secondary antibody such that cells had a uniform speak with a median fluorescent intensity of approximately 1-5 units. Live cells were acquired by gating for FSC and propidium iodide exclusion. For each sample, approximately 10,000 live cells were acquired for analysis and the results presented in Table 2.
[0049] Table 2 tabulated the mean fluorescence intensity fold increase above isotype control and is presented qualitatively as: less than 3 to 5 (+); 5 to 25 (++); 25 to 50 (+++); and above 50 (++++). Representative histograms of 10A304.7 antibody were compiled for FIG. 1 and evidence of the binding characteristics, inclusive of illustrated bimodal peaks in some cases. 10A304.7 non-specifically bound to all cell lines, including high binding to the non-cancer cells CCD 27sk and Hs888.Lu, but the degree of binding differed between the various cell lines. 10A304.7 thus selectively bound to the cell lines at different levels. Results from Tables 1 and 2 indicate that the binding of 10A304.7 to tumor cells is necessary for antibody-mediated cytotoxicity but it is not sufficient in triggering this event.
TABLE 2 Colon Pancreas Breast Prostate Ovary Normal Cells Caco-2 DLD-1 Lovo HT-29 SW1116 SW620 BxPC-3 MB-231 MCF-7 PC-3 OVCAR CCD 27sk Hs888.Lu 10A304.7 ++++ ++ +++ ++++ +++ ++++ +++ ++++ ++ ++++ ++++ ++++ ++++ (bimodal) (bimodal) Anti-Fas ++ ++ ++ + ++ ++ ++ +++ Anti- ++ ++ +++ ++ +++ ++++ ++ +++ +++ ++ +++ EGFR (bimodal) (bimodal)
EXAMPLE 2
[heading-0050] In Vivo MB-231 Tumor Experiments
[0051] With reference to FIGS. 2 and 3 , 4 to 8 week old female SCID mice were implanted with 5 million MDA-MB-231 human breast cancer cells (MB-231) in 100 microlitres saline injected subcutaneously in the scruff of the neck. The mice were randomly divided into 2 treatment groups of 5. On the day after implantation, 20 mg/kg of 10A304.7 test antibody or isotype control antibody (known not to bind MB-231 cells) was administered intraperitoneally at a volume of 300 microliters after dilution from the stock concentration with a diluent that contained 2.7 mM KCl, 1 mM KH 2 PO 4 , 137 mM NaCl and 20 mM Na 2 HPO 4 . The antibodies were then administered once per week for a period of 7 weeks in the same fashion. Tumor growth was measured about every seventh day with calipers for up to 10 weeks or until individual animals reached the Canadian Council for Animal Care (CCAC) end-points. Body weights of the animals were recorded for the duration of the study. At the end of the study all animals were euthanised according to CCAC guidelines.
[0052] 10A304.7 prevented tumor growth and reduced tumor burden in a preventative in vivo model of human breast cancer. On day 56 post-implantation, 6 days after the last treatment dose, the mean tumor volume in the 10A304.7 treated group was 1 percent of the tumor volume in the isotype control treated group (p=0.0003, t-test, FIG. 2 ). There were no clinical signs of toxicity throughout the study. Body weight measured at weekly intervals was a surrogate for well-being and failure to thrive. There was no significant difference in body weight between the groups at the end of the treatment period (p=0.3512, t-test). Therefore 10A304.7 was well-tolerated and decreased the tumor burden in a breast cancer xenograft model.
[0053] All patents and publications mentioned in this specification are indicative of the levels of those skilled in the art to which the invention pertains. All patents and publications are herein incorporated by reference to the same extent as if each individual publication was specifically and individually indicated to be incorporated by reference.
[0054] It is to be understood that while a certain form of the invention is illustrated, it is not to be limited to the specific form or arrangement of parts herein described and shown. It will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification. One skilled in the art will readily appreciate that the present invention is well adapted to carry out the objects and obtain the ends and advantages mentioned, as well as those inherent therein. Any oligonucleotides, peptides, polypeptides, biologically related compounds, methods, procedures and techniques described herein are presently representative of the preferred embodiments, are intended to be exemplary and are not intended as limitations on the scope. Changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims. Although the invention has been described in connection with specific preferred embodiments, it should be understood that the invention as claimed should not be unduly limited to such specific embodiments. Indeed, various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims.
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The present invention relates to a method for producing patient cancerous disease modifying antibodies using a novel paradigm of screening. By segregating the anti-cancer antibodies using cancer cell cytotoxicity as an end point, the process makes possible the production of anti-cancer antibodies for therapeutic and diagnostic purposes. The antibodies can be used in aid of staging and diagnosis of a cancer, and can be used to treat primary tumors and tumor metastases. The anti-cancer antibodies can be conjugated to toxins, enzymes, radioactive compounds, and hematogenous cells.
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RELATED APPLICATIONS
The present invention was first described in a notarized Official Record of Invention on Dec. 16, 2008, that is on file at the offices of Montgomery Patent and Design, LLC, the entire disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to bow making apparatus, and more particularly, to an apparatus and method for making decorative bows made of ribbon.
BACKGROUND OF THE INVENTION
Bow making is a time honored craft that dates back many generations. Handmade bows can be used for decorating packages in their small sizes, while larger ones can be used to decorate buildings and other large objects. It is common for such bows to be made by hand using simple jig-based machines that allows a user to wrap ribbon or similar fabric material around movable dowel rods. Hand crafting allows a bow maker to produce original and creative bow designs in a manner which is lost using complex automated bow making machines.
While traditional hand crafting bow making processes work, they typically require the bow maker to secure the ribbon in place around a central post for the entire bow making process. If the ribbon should be let go, the entire bow may simply fall apart forcing the user to start over. This is a detrimental factor in an otherwise enjoyable craft. Various attempts have been made to provide hand made bow making apparatus. Examples of such attempts can be seen in several U.S. patents: U.S. Pat. No. 3,850,293, issued in the name of Scaringi, describing a bow making kit; U.S. Pat. No. 4,629,100, issued in the name of Owens, describing an apparatus for tying bows; U.S. Pat. No. 5,094,370, describing a method and fixture for center-loop bow making; U.S. Pat. No. 5,411,188, issued in the name of Teuten, describing an adjustable frame bow making device; U.S. Pat. No. 5,810,214, issued in the name of Hecht, describing a method and device for bow making; U.S. Pat. No. 6,000,586, issued in the name of Cavender, describing a bow making apparatus; and, U.S. Pat. No. 6,131,778, issued in the name of Etzion, describing a bow maker with ribbon securing element.
Additionally, various designs exist for bow making devices. Examples of such designs can be seen in U.S. Pat. No. D 291,841, issued in the name of Owens and U.S. Pat. No. D 389,998, issued in the name of Cavender et al.
The disclosures of these examples are incorporated herein by reference. While these attempts may fulfill their respective, particular objectives, each suffers from one (1) or more disadvantages or deficiencies. Accordingly, there is a need for a means by which decorative bows of various sizes can be made without the disadvantages of conventional bow making jigs. The development of the present invention substantially departs from the conventional solutions and in doing so fulfills this need.
SUMMARY OF THE INVENTION
In view of the foregoing prior art references, the inventor recognized inherent problems in devices intended to manufacture decorative bows by hand and observed that there is a need for an apparatus which provides bow makers a means and method to hand craft their own original bows in various sizes in a manner which is effective and thus, the object of the present invention is to solve the aforementioned disadvantages and provide for this need.
Another object of the present invention is to provide a bow tying apparatus which is modular and simple to use and allows a bow maker to make original bows from approximately two inches in diameter up to approximately fourteen inches in diameter.
Another object of the present invention is to provide an apparatus which enables bow makers to utilize bow making material of various widths to manufacture narrow ribbon bows and wide ribbon bows.
Another object of the present invention is to provide an integral storage area for all components of the apparatus, thus making storage convenient.
Another object of the present invention is to provide clear bow making instructional guides integral to a work surface.
Another object of the present invention is to provide an apparatus which is durable, lightweight, and simple and cost effective to manufacture.
To achieve these objectives and advantages, the present invention provides a bow tying apparatus having a generally rectangular main body which provides a work surface for receiving and retaining a continuous length of bow making materials. This bow making material can either be of a preselected length or be deployed from a spool of bow making material. One (1) embodiment of the apparatus provides a plurality of apertures on a face of the main body, into which a pointed lance and a pair of rods are inserted. The apparatus includes a plurality of lances and pairs of rods having varying lengths to accommodate various widths of bow making material. The lance is set in a main lance aperture having a central position in relation to a plurality of pairs of rod apertures disposed at incremental distances on both sides of the main lance aperture. The pair of rods is set in a selected pair of rod apertures each at a desired preselected distance from the lance. This preselected distance is equivalent to the desired diameter of a manufactured bow. A first end of the continuous length of bow making material is retained to the work surface by piercing with the lance, while the remaining length of bow making material is wound around the pair of rods forming a plurality of bow loops. Each time the continuous length of bow making material passes over the lance, it is pierced by the lance thus retaining a base portion of each loop.
Furthermore, the described features and advantages of the invention may be combined in various manners and embodiments as one skilled in the relevant art will recognize. The invention can be practiced without one or more of the features and advantages described in a particular embodiment.
Further objects and advantages of the present invention will become apparent from a consideration of the drawings and ensuing description.
BRIEF DESCRIPTION OF THE DRAWINGS
The advantages and features of the present invention will become better understood with reference to the following more detailed description and claims taken in conjunction with the accompanying drawings, in which like elements are identified with like symbols, and in which:
FIG. 1 is an environmental view of a bow tying apparatus 10 , according to a preferred embodiment of the present invention;
FIG. 2 is a front perspective view of the bow tying apparatus 10 , according to a preferred embodiment of the present invention;
FIG. 3 is an exploded view of the bow tying apparatus 10 , according to a preferred embodiment of the present invention;
FIG. 4 is a rear view of the bow tying apparatus 10 , according to a preferred embodiment of the present invention;
FIG. 5A is a side view of a sheath 44 , according to a preferred embodiment of the present invention; and,
FIG. 5B is a bottom view of the sheath 44 , according to a preferred embodiment of the present invention.
DESCRIPTIVE KEY
10
bow tying apparatus
20
face portion
22
top portion
24
rear portion
26
high friction surface
30
first rod
31
first rod aperture
32
second rod
33
second rod aperture
34
third rod
35
third rod aperture
36
rod aperture
38
width indicia
40
first lance
41
first lance aperture
42
second lance
43
second lance aperture
44
sheath
45
sheath aperture
46
sheath body
47
sheath center aperture
48
main lance aperture
49
lance indicia
50
spool rod
51
spool rod aperture
52
first spool aperture
54
second spool aperture
56
spool indicia
60
directional indicia
62
start indicia
64
finish indicia
70
spool
72
ribbon
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The best mode for carrying out the invention is presented in terms of its preferred embodiment, herein depicted within FIGS. 1 through 5B . However, the invention is not limited to the described embodiment and a person skilled in the art will appreciate that many other embodiments of the invention are possible without deviating from the basic concept of the invention, and that any such work around will also fall under scope of this invention. It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.
The terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced items.
The present invention describes a bow tying apparatus and method of use (herein described as the “apparatus”) 10 , which provides a means for creating decorative bows. The apparatus 10 comprises a main structure, a plurality of rods 30 , 32 , 34 , a plurality of rod apertures 31 , 33 , 35 , a first lance 40 , a second lance 42 , and a multiplicity of indicia. The apparatus 10 allows a user to create various sized bows from conventional spools of ribbon 72 in a secure manner.
Referring now to FIG. 1 , an environmental view of the apparatus 10 , according to the preferred embodiment of the present invention, is disclosed. The apparatus 10 comprises an elongated main body measuring preferably twenty-one-and-a-half (21½) inches in length by a half (½) inch in height. The main structure comprises a face portion 20 providing a main work area for a user. The face portion 20 is further comprised of a plurality of rod apertures 36 enabling insertion of a plurality of rods 30 , 32 , 34 and a plurality of width indicia 38 enabling an approximate measurement for the width of a bow. The face portion 20 further comprises a section for the placement of a spool 70 , thereby enabling ribbon 72 to be secured onto the apparatus 10 during use. The apparatus 10 is fabricated from materials such as, but not limited to: plastic, wood, or the like in well-known processes such as wood shaping and finishing as well as plastic injection molding.
Referring now to FIG. 2 , a front perspective view of the apparatus 10 and FIG. 3 , an exploded view of the apparatus 10 , according to the preferred embodiment of the present invention, are disclosed. The apparatus 10 comprises a pair of first rods 30 , a pair of second rods 32 , a pair of third rods 34 , a plurality of rod apertures 36 , a plurality of width indicia 38 , a first lance 40 , a first lance aperture 41 , a second lance 42 , a second lance aperture 43 , a sheath 44 , a sheath aperture 45 , lance indicia 49 , a spool rod 50 , a spool rod aperture 51 , a first spool aperture 52 , a second spool aperture 54 , spool indicia 54 , a main lance aperture 48 , directional indicia 60 , start indicia 62 , and finish indicia 64 .
A top portion 22 of the apparatus 10 is utilized for storage of the pair of first rods 30 , the pair of second rods 32 , the pair of third rods 34 , the first lance 40 , the second lance 42 , the sheath 44 , and the spool rod 50 , thereby supplying each with a corresponding aperture 31 , 33 , 35 , 41 , 43 , 45 , 51 . The apertures 31 , 33 , 35 , 41 , 43 , 45 , 51 are drilled to appropriate depths to receive each corresponding item. The apparatus 10 also comprises a plurality of rod apertures 36 and a main lance aperture 48 providing a secure in-use placement for the rods 30 , 32 , 34 and the lances 40 , 42 , respectively. A desired pair of rods 30 , 32 , 34 are inserted therein an appropriate rod aperture 36 , thereby enabling the user to create various sized bows. The rod apertures 36 are located at an intermediate position thereon the face portion 20 . The rod apertures 36 are also labeled with width indicia 38 which correspond to the width of the bow to be manufactured. The width indicia 38 preferably comprise descending and ascending digits corresponding to the width. The width ranges from two (2) inches to fourteen (14) inches.
The diameter of the pair of first rods 30 , the diameter of the pair of second rods 32 , and the diameter of the pair of third rods 34 are equivalent, thereby allowing any rod 30 , 32 , 34 to be inserted thereinto any rod aperture 36 . The lengths of the rods 30 , 32 , 34 differ, thereby fitting a variety of sized bows. The first rod 30 is approximately three-and-a-half (3½) inches in length, the second rod 32 is approximately two-and-a-half (2½) inches in length, and the third rod 34 is approximately one-and-a-half (1½) inches in length. Each rod 30 , 32 , 34 is preferably fabricated from a material such as, but not limited to: wood, plastic, or the like.
The apparatus 10 comprises a first lance 40 and a second lance 42 enabling a user to impale the ribbon 72 securely in place to prevent the bow from separating during manufacturing. The first lance 40 is approximately three (3) inches in length and the second lance 42 is approximately two (2) inches in length. The first lance 40 is utilized for the manufacturing of large bows and the second lance 42 is utilized for the manufacturing of small bows. A top portion of the lances 40 , 42 comprises a threaded area enabling a secure insertion into the threaded main lance aperture 48 located thereon the face portion 20 of the apparatus 10 . The main lance aperture 48 is an appropriate diameter to allow insertion of the lances 40 , 42 . The main lance aperture 48 is also labeled with lance indicia 49 to clearly communicate to the user where to insert the lance 40 , 42 . The lance indicia 49 preferably comprise words or images to communicate proper placement of the lance 40 , 42 such as, but not limited to: LANCE, CENTER PIN, or the like. A bottom portion of each lance 40 , 42 comprises a sharp point to skewer the ribbon 72 . The lances 40 , 42 are fabricated from materials such as, but not limited to: metal, plastic, or the like. To protect the user from a sharp end portion thereon a tip of each lance 40 , 42 a sheath 44 is provided (see FIGS. 5A and 5B ). The sheath 44 is stored on the top portion 22 therein a sheath aperture 45 .
The apparatus 10 also comprises a spool rod 50 for securing a spool 70 of ribbon 72 thereto the face portion 20 . The spool rod 50 is comprises of a tubular rod stored on the top portion 22 therein a spool rod aperture 51 . The spool rod aperture 51 comprises an appropriate diameter that corresponds to the diameter of the spool rod 50 . When the apparatus 10 is in-use the spool rod 50 is inserted into a first spool rod aperture 52 or a second spool rod aperture 54 depending on the size of the spool 70 and size of bow desired. The user preferably places a spool 70 on the face portion 22 , superjacent to the spool rod apertures 52 , 54 and slidably inserts the spool rod 50 into the spool 70 and spool rod aperture 52 , 54 , thereby securing the spool to the apparatus 10 . Spool indicia 56 are also located thereon the face portion 22 allowing a user to clearly position a spool 70 in an appropriate location. The spool indicia 56 preferably comprise words or images pertaining to bow making such as, but not limited to: SPOOL, RIBBON, or the like. The spool rod 50 is approximately three-and-a-half (3½) inches in length and fabricated from materials similar to the abovementioned rods 30 , 32 , 34 .
The apparatus 10 further comprises indicia to communicate proper bow making procedures to the user. The indicia are located on the face portion 20 and centered around the rod apertures 36 and width indicia 38 . The indicia comprises start indicia 62 for showing a user where to begin the tail of the ribbon 72 . The start indicia 62 preferably comprises words, letters, or images pertaining to the start of manufacturing a bow such as, but not limited to: “S”, START, BEGIN, or the like. The indicia also comprise finish indicia 64 for communicating to the user where to stop the ribbon 72 . The finish indicia 64 preferably comprises words, letters, or images pertaining to the end of manufacturing a bow such as, but not limited to: “F”, STOP, FINISH, or the like. The indicia further comprise directional indicia 60 for communicating to the user the proper path to follow for manufacturing a bow. The directional indicia 60 begin at the start indicia 62 and follow a figure-eight (8) path ending at the finish indicia 64 . The directional indicia 60 is preferably arrows, dashed lines, or the like which clearly show the appropriate path the user should follow.
Referring now to FIG. 4 , a rear view of the apparatus 10 , according to the preferred embodiment of the present invention, is disclosed. A rear portion 24 of the apparatus 10 comprises a high friction surface 26 for stabilizing the apparatus 10 on a working surface such as, but not limited to: a table top, a user's lap, or the like. Said high friction surface 26 is located either on the entire rear portion 24 or crucial regions on the rear portion 24 . The high friction surface 26 is preferably comprised of non-slip materials such as, but not limited to: rubber, adhesive, fasteners, or the like.
Referring now to FIG. 5A , a side view of the sheath 44 and FIG. 5B , a bottom view of the sheath 44 , according to the preferred embodiment of the present invention, are disclosed. FIG. 5A depicts the second lance 42 for illustration purposes only; it is known that either the first lance 40 or second lance 42 may be utilized in the same manner. The apparatus 10 comprises a sheath 44 for providing a protective covering to the lances 40 , 42 when they are not in use to protect the user from the sharp end portions of the lances 40 , 42 . The sheath 44 comprises a tubular sheath body 46 which further comprises a sheath center aperture 47 enabling the insertion of the lance 40 , 42 . The sheath center aperture 47 extends thereinto the sheath body a maximum depth of the length of the first lance 40 allowing either lance 40 , 42 to fit thereinside. The sheath 44 is stored thereon the top portion 22 of the apparatus 10 therein the sheath aperture 45 (see FIG. 2 ). The sheath 44 is preferably fabricated from a similar material as the apparatus 10 .
It is envisioned that other styles and configurations of the present invention can be easily incorporated into the teachings of the present invention, and only one particular configuration shall be shown and described for purposes of clarity and disclosure and not by way of limitation of scope.
The preferred embodiment of the present invention can be utilized by the common user in a simple and effortless manner with little or no training. After initial purchase or acquisition of the apparatus 10 , it would be installed as indicated in FIGS. 1 through 5B .
The method of installing and utilizing the apparatus 10 may be achieved by performing the following steps: acquiring the apparatus 10 ; determining the width of bow to create and utilizing an appropriate sized rod 30 , 32 , 34 ; removing a desired rod 30 , 32 , 34 from the top portion 22 ; inserting the rod 30 , 32 , 34 into a rod aperture 36 which corresponds to an appropriate width indicia 38 needed to create the desired size of bow; placing a spool 70 on top of a desired spool aperture 52 , 54 ; removing the spool rod 50 from the top portion 22 and inserting it thereinto the spool 70 and spool aperture 52 , 54 ; removing a desired lance 40 , 42 and sheath 44 from the top portion 22 ; inserting the lance 40 , 42 thereinto the sheath center aperture 47 and inserting the threaded end portion of the lance 40 , 42 thereinto the main lance aperture 48 ; unwrapping a desired length of ribbon 72 from the spool 70 ; positioning the tail of the ribbon 72 at the start indicia 62 , removing the sheath 44 from the lance 40 , 42 , and impaling the ribbon 72 through the lance 40 , 42 creating a starting position; following the directional indicia 60 to create a bow; impaling the ribbon 72 in accordion fashion every time said ribbon 72 crosses the main lance aperture 48 ; cutting the ribbon 72 at the finish indicia 64 when a desired size of bow is created; cutting the ribbon 72 from the spool 70 ; securing a center portion of the bow with a desired fastening means; removing the manufactured bow from the lance 40 , 42 ; fanning-out the loops of the bow and cutting the tails of the bow as necessary; creating additional bows as necessary and following the abovementioned steps; replacing the lance 40 , 42 thereinto an appropriate lance aperture 41 , 43 ; replacing the sheath 44 thereinto the sheath aperture 45 ; replacing the rod 30 , 32 , 34 thereinto the first rod aperture 31 , second rod aperture 33 , or third rod aperture 35 ; removing the spool rod 50 from the spool 70 ; replacing the spool rod 50 thereinto the spool rod aperture 51 ; storing the apparatus 10 ; and, enjoying the ease of creating decorative bows for all occasions.
The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, to thereby enable others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.
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An apparatus and method of use for making a decorative bow is herein disclosed, comprising a removable lance used to retain a length of bow making material about a central location. The lance prevents each winded loop from coming apart during the bow making process. The apparatus is provided with a plurality of pairs of removable support rods, each pair having different lengths to accommodate varying widths of bow making material. In a preferred embodiment, the apparatus provides guide indicia to indicate suggested bow making directions and a support rod to hold a spool of bow making material during manufacture. A non-slip covering is provided thereon the base to prevent the apparatus from moving during use.
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BACKGROUND
[0001] When used for medical, surgical and other applications, instruments are generally sterilized prior to use. A common method of preparing instruments for use in sterile environments such as an operating room or medical procedure room is to place a cleaned, but not yet sterilized, instrument into a plastic pouch. The instrument in the pouch is then sterilized in a sterilization device. Typically, instruments are placed in sterilization pouches by human technicians. This involves human handling of the instruments, manual selection of proper pouches, manual labeling of pouches, manual sealing of pouches, and manual logging of data for sterilization records.
[0002] Human handling of such instruments prior to sterilization is labor intensive and error prone. It remains desirable to have systems and methods for automating this process.
SUMMARY
[0003] The present invention is directed to systems and methods for identifying and packaging instruments and logging production data.
[0004] In a first embodiment, a system for packaging instruments includes an input for receiving instrument identification data. The system further includes an instrument processor coupled to the input. The instrument processor includes a database and an instrument analyzer. The database stores instrument type data, instrument packaging data and package labeling data. The instrument analyzer identifies instrument type and determines instrument packaging and labeling using data stored in the database. The instrument analyzer further determines instrument handling, packaging and labeling instructions. An output coupled to the instrument processor sends the handling, packaging and labeling instructions to at least one external device. The at least one external device in various embodiments includes a labeler, a packager and an instrument transfer device.
[0005] In one embodiment, the packager is a packaging turret that holds a plurality of sizes or types of instrument pouches. The specific package is selected based on the received instructions from the instrument processor. In an alternative embodiment, the packager is a unit that holds a roll of packaging tubing and cuts and forms a package in response to instructions received from the instrument processor.
[0006] The instrument transfer device in a first embodiment is a catch and release mechanism. The instrument transfer device in a second embodiment is a robotic arm. In both these embodiments, the transfer device moves an instrument from a receiving element such as a conveyor or an instrument identification platform and transfers the instrument to a packaging element such as a peel pouch.
[0007] The present invention together with the above and other advantages may best be understood from the following detailed description of the embodiments of the invention illustrated in the drawings, wherein:
DRAWINGS
[0008] FIG. 1 is a flow chart of the operation of an embodiment of an automated instrument processing and packaging system according to principles of the invention;
[0009] FIG. 2 is a block diagram of an embodiment of an automated instrument processing system according to principles of the invention;
[0010] FIG. 3 is a flow chart of the operation of an alternative embodiment of an automated instrument processing and packaging system;
[0011] FIG. 4 is a flow chart of the operation of an embodiment of an alternative embodiment of an instrument processing system according to principles of the invention; and
[0012] FIG. 5 is an illustration of an alternative embodiment of an automated instrument processing system according to principles of the invention.
DESCRIPTION
[0013] Embodiments of the present invention enable automated processing and packaging and logging of instrument data for a plurality of surgical instruments.
[0014] A system for automating peel pouch production follows the flow chart in FIG. 1 . At step 101 , an instrument type is determined. When an instrument enters into the system for processing, the instrument may be labeled or unlabeled. Determining the instrument type may involve reading a label or analyzing the instrument. This is described in greater detail below. At step 102 , the data specific to the creation of the peel pouch is determined based on the instrument type. The peel pouch data may include, but is not limited to, the information for the peel pouch label, and the pouch type and size. At step 103 , the peel pouch is created, or made. Peel pouch creation includes the steps of producing an appropriately-sized pouch, affixing a label to the pouch, placing one or more instruments inside the pouch, and sealing the pouch.
[0015] FIG. 2 is a block diagram of an automated instrument packaging system 110 . The instrument packaging system 110 includes an instrument processor 112 having an input 114 and an output 116 , an instrument analyzer 118 and an instrument database 120 . An instrument identification platform 122 , a labeler 124 , a packager 126 and a transfer device 128 are all in communication with the instrument processor 112 .
[0016] The instrument identification platform 122 includes one or more instrument identifying devices. The instrument identifying platform 122 automates the process of determining instrument type. One embodiment employs a machine vision system to recognize the instrument type. Another embodiment employs a bar code reader. Yet another embodiment employs an RFID scanner. Other means of recognizing a particular instrument are possible within the scope of the invention. The instrument identification platform submits the instrument identification data to the instrument processor 112 through the input 114 .
[0017] The instrument analyzer 118 receives the instrument identification data provided by the instrument identification platform 122 . If the instrument identification platform was not able to specifically identify the instrument type, the instrument analyzer 118 accesses data stored in the instrument database 120 to identify the particular instrument by comparing the received data with stored data. The instrument analyzer 118 also determines instrument packaging data based on the instrument type and information stored in the instrument database 120 .
[0018] In one embodiment, the instrument analyzer 118 includes a peel pouch data device. The peel pouch data device receives instrument type information from the instrument identification platform 122 or another source. Using the instrument type, the peel pouch data device may access stored information in the database 120 regarding peel pouch data that pertains to the identified instrument type.
[0019] Additional embodiments of the system employ an output device 116 . The output device 116 provides data from the peel pouch data device and automates the creation of a peel pouch. One embodiment uses a computer monitor for quickly displaying the peel pouch data and providing instruction to an operator for producing the peel pouch. In an alternative embodiment, the output device is in communication with a labeler 124 , for example a printer that produces the label to be affixed to the peel pouch. Additional embodiments include a packager 126 , that is, a device for automatically producing a pouch of the required size. The packager 126 may make the pouch from a roll of tubing, or may select a pre-made pouch. In an alternative embodiment of the packager 126 , the packager has a selection of pre-made pouches that the packager presents to receive one or more instruments.
[0020] In another alternative embodiment, the packager 126 selects a desired amount of packaging material, places the one or more instruments in the selected packaging material, closes and seals the packaging material, prints the label with the selected information and places the label on the package or pouch and sends the instrument data to a log. The log may reside in the packager 126 or alternatively in the instrument database 120 . Other locations are possible within the scope of the invention.
[0021] The system 110 can include a transfer device 128 . In one embodiment, the transfer device 128 is a conveyor to move the one or more instruments both before and after packaging. The transfer device 128 may also include a robotic arm or similar mechanical device to handle the one or more instruments and place them in the selected packaging. In another embodiment, the transfer device 128 may also transfer the package or pouch to a sterilization device.
[0022] In one alternative embodiment of the system 110 , the labeler 124 prints information directly on the packaging. Alternatively, the label can be affixed to the packaging manually or by an external applicator. In still other embodiments, a sterility indicator may be placed in the selected packaging with the one or more instruments. In other embodiments, the packaging material can be heat sealed after the one or more instruments are placed in it, or it can be sealed by an external means. In still another embodiment, the one or more instruments can be placed in the selected packaging by external means, such as a user, and the system then notified that the packaging is ready to be sealed.
[0023] Additionally, the system can be configured to identify and package medical items other than instruments, such as, for example, implantable items and tubing connections.
[0024] FIG. 3 is a flow chart for the operation of an automated system for the identification, package selection, and packaging of instruments for sterilization such as that shown in the block diagram of FIG. 2 . At step 10 , the system provides that an instrument is selected. At step 11 , the instrument is placed on an instrument identification platform which in one embodiment includes a conveyor. One skilled in the art will recognize that the system may be used for packaging of other components and materials in medical and nonmedical applications.
[0025] As shown in FIG. 3 , at step 12 , the system employs a device to recognize the instrument using, for example, machine vision, barcodes, RFIDs, or other indicia. The recognition device may be incorporated into the system or may be external. If the system recognizes the instrument, the system proceeds to step 14 . If the system does not recognize the instrument, the system proceeds to step 13 .
[0026] At step 13 , information about the instrument is compared with a database of known instruments. When the instrument is identified using this comparison, the system proceeds to step 14 .
[0027] At step 14 , the desired packaging is determined and then selected or created based on instrument identification. In a first embodiment, the desired packaging is selected from an inventory of various sizes of packaging. In an alternative embodiment, customized packaging or pouches are cut from bulk packaging material utilizing information from the database of known instruments. The bulk packaging could consist of tubing material.
[0028] At step 15 , a label is printed on the packaging or alternatively, it is printed on a label which is then applied to the packaging.
[0029] At step 16 , with continued reference to FIG. 1 , the instrument is placed in the desired packaging using mechanical or automated means, including for example, a robotic arm.
[0030] At step 17 , the packaging is then sealed and the instrument is ready for sterilization.
[0031] At step 18 , the instrument is then placed in a storage area.
[0032] FIG. 4 is a flow chart for the operation of another embodiment of an automated system for the identification, package selection, and packaging of instruments for sterilization. At step 201 , the system provides that an instrument is selected. At step 202 , the instrument is placed on a conveyor and an operator initiates the process. One skilled in the art will recognize that the system may be used for packaging of other components and materials in medical and nonmedical applications.
[0033] At step 203 , the system employs a device to recognize the instrument using, for example, machine vision, barcodes, RFIDs, or other indicia. The recognition device may be incorporated into the system or may be external.
[0034] At step 204 , the data related to creating a peel pouch from the identified instrument is retrieved. The data may be stored in a relational database and retrieved by using the instrument type.
[0035] At step 205 , the desired packaging is created or retrieved. In a first embodiment, the desired packaging is selected from an inventory of various sizes of packaging. In an alternative embodiment, customized packaging or pouches are cut from bulk packaging material utilizing information from the database of known instruments. The bulk packaging could consist of tubing material.
[0036] At step 206 , a label is printed on the packaging or alternatively, it is printed on a label which is then applied by an operator to the packaging.
[0037] At step 207 , the operator places the instrument in the pouch and seals it using a heat sealer or equivalent.
[0038] FIG. 5 illustrates elements of a system for automated instrument sterilization according to one embodiment of the invention. The system includes a conveyor 250 for instrument conveyance. A catch release mechanism 255 is attached to the conveyor for catching the conveyed instrument. A looped instrument chute 260 is attached to the catch release mechanism and feeds the instrument to a packaging turret 265 . The system further includes a label printer 270 .
[0039] In operation, an instrument to be sterilized is placed on the conveyor. The camera is positioned in relation to the conveyor so that the instrument is in the camera's field of view. The system receives data about the instrument through the camera. In alternative embodiments, other sensors may be used to take instrument data. After data about the instrument is taken, the instrument is conveyed into the catch release mechanism and from there into is sent into the looped instrument chute. The instrument is received from the instrument chute at a packaging turret.
[0040] The packaging turret has a plurality of pouches ready to receive instruments. The turret receives the instrument into a pouch selected by the sterilization system. In a first embodiment, the pouches are different sizes and the sterilization system selects a pouch of an appropriate size for the instrument. In an alternative embodiment, the looped instrument chute is positioned over a selected pouch. In a further alternative embodiment, the turret moves under the instrument chute and the sterilization system directs the turret to position an appropriate pouch for the instrument under the chute.
[0041] The pouch with an instrument is then processed by the system as described above with regard to FIG. 1 . The label printer prints labels. The pouches are labeled and processed in a sterilization unit and then placed into storage.
[0042] The automated system described above enables instruments to be identified, packaged and sterilized without human handling. The automated system provides the benefits of increased safety in the contaminated instruments are not handled by people who could become infected and also that the instruments themselves will not become contaminated from handling by people. Further, the system enables accurate sorting and labeling and efficient packaging.
[0043] It is to be understood that the above-identified embodiments are simply illustrative of the principles of the invention. Various and other modifications and changes may be made by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.
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Systems and methods for handling and packaging instruments are fully automated thereby eliminating human handling and increasing accuracy of packaging and labeling of the instruments. One system includes an instrument identification element, an element that determines packaging requirements, an element that creates the packaging such as a labeled peel pouch. The system makes the package including the instrument or instruments. The completed packaging is ready of next steps including sterilization.
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CLAIM OF PRIORITY
[0001] This application claims benefit of U.S. Provisional Application No. 61/276,269, filed Sep. 10, 2009, which is incorporated herein by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The use of solar thermal power for generating electricity on a utility scale is having a resurgence of interest in light of global warming issues caused largely by the release of carbon dioxide, methane, and absorbing particulates in the atmosphere and to the increasing of fossil fuels. The use of concentrated solar energy to heat a working fluid to a high temperature to operate Rankin, Brayton, and Sterling cycle engines to provide mechanical power to operate a generator for utility scale electric power production offers an attractive alternative to the use of fossil fuels. However, utilities are generally requesting that power production facilities provide dispachable power on the order of 75% of the year. Since the sun is only above the horizon 50% of the time on a yearly basis, there is a need to provide some form of storage to operate the plant when there is no sunlight available.
[0003] Thermal energy storage may be accomplished by storing the energy in the form of heat, either as sensible heat or latent heat (or a combination thereof). Current solar collectors utilize heliostats, parabolic troughs or liner Fresnel reflectors to concentrate sunlight on solar receivers. These receivers are heated by the concentrated sunlight and utilize steam, oil, liquid salt, liquid alkali metal or gas as the heat collection and transfer fluid. This fluid may be used as the heat storage medium itself or the heat may be transferred to another medium to provide the storage. Thermal storage may be provided by the sensible heat in tanks of oil, oil and rock, liquid salts, or liquid alkali metals as discussed by Geyer in Winter et. al. The fluids heated by the concentrated sunlight are used to generate steam, heat a working fluid for energy conversion or they may be stored at high temperatures (or in combination). After giving up their heat for energy conversion the cooled fluids are stored separately from the hot fluids. This may be accomplished in separate hot and cold tanks or by using a thermocline configuration. In the thermocline system, the colder (denser) fluid forms the bottom layer with the hotter (less dense) fluid forms the upper layer. In any of these configurations, when the sun is not providing heat, the stored hot liquid may be pumped through the heat exchanger to heat the working fluid for power production and then to the cold side of the storage to complete the cycle.
[0004] Alternatively, the latent heat of fusion may be used to store thermal energy. Liquid salts or alkali metals that undergo a phase change to store or release heat at their melting temperature have been used in thermal storage systems. An advantage of this form of heat storage is that the heat is released at a nearly constant temperature, providing the optimum operating conditions for the energy conversion cycle. Another advantage to the use of latent heat energy storage occurs because the amount of storage material can be significantly decreased. To clarify, the amount of energy stored in specific heat is determined by the product of the specific heat and the temperature change. For example; the specific heat of water is 1 cal/gm, if the temperature is lowered by 1° C., one gram of the water releases 1 calorie of heat. Alternatively, the latent heat of fusion of water is about 80 cal/gm so that the energy released in freezing or solidifying one gram of ice is 80 calories of heat at a nearly constant temperature. Thus, the amount of water needed to store the same amount of heat that is provided by freezing one gram of ice is 80 times greater than that to change the temperature of the water by 1° C.
[0005] In latent heat storage systems using high temperature salts, there are restrictions in the heat flow into and out of the storage material due to the low conductivity of salt. This is further aggravated by the fact that as the heat storage is discharging, the salt freezes around the pipes carrying the heat exchange fluid which stops convective heat transfer. This reduces the rate at which the heat that can be extracted from the storage system. Thus the combination of the low conductivity of the salt and the curtailment of convection due to the immobility of the salt presents obstacles to the utilization of this type of latent heat storage system.
[0006] Another consideration in the operation of a solar power system is the operating temperatures. To make concentrated solar thermal power systems as cost effective as possible, it is desirable to maximize the efficiency of the power conversion cycle. This reduces the cost of the most expensive component of the plant; the concentrating collectors. Since the maximum efficiency of a heat engine is determined by the temperature difference between the hot and cold reservoirs between which it operates, operating at the highest temperature possible is most desirable. Oils break down at temperatures above about 400° C. Most thermal storage systems using salt operate below about 570° C. No effective means have been found to store steam at the pressures and temperatures required to run efficient Rankin cycle engines. Brayton or gas cycle engines use gas as a working fluid and again it is impracticable to store gas at very high temperatures and pressures. The Brayton cycle provides the highest efficiencies for power tower concentrating systems because the operating temperatures are only limited by the turbine inlet temperatures (well over 1000° C.). Storing high temperature gas is not a realistic energy storage option.
INCORPORATION BY REFERENCE
[0007] The following references are incorporated herein in their entireties:
[0008] U.S. Pat. No. 4,512,388, issued Apr. 23, 1985, by Terry D. Claar et al., entitled “High-Temperature Direct-Contact Thermal Energy Storage Using Phase-Change Media”; Simensen “Comments on the Solubility of Carbon in Molten Aluminum” Metallurgical Transactions A Vol. 20A January 1989, p. 191;
[0009] Winter, Sizmann, @ Vant-Hull, Solar Power Plants, Chapter 6, Springer, Verlag 1991; and
[0010] Guthy and Makhlouf “The aluminum-silicon eutectic reaction: mechanisms and crystallography” Journal of Light Metals Vol. 1, No. 4, November 2001, pp. 199-218.
SUMMARY OF THE INVENTION
[0011] Embodiments of the invention relate to the use of melting and solidifying or freezing metals and metal alloys to store and release the high latent heat of fusion of certain metals and alloys to store large amounts of heat energy at very high temperatures suitable for operating a gas turbine or other purposes. In particular, the alloy may consist of two or more metals with melting and eutectic temperatures in the range that is compatible with the energy conversion device to be used.
[0012] In the first embodiment considered here, the metal or alloy is contained in an array of tubes located in an insulated channel through which the high temperature gas is circulated. The system is charged by passing gas, from the solar receiver or other heat source, past the tubes in order to heat and melt the metal/alloy contained within the tubes. The system is discharged by passing the air to be heated through the same channel until the metal or alloy has changed phase (liquid to solid) and the temperature has dropped to the optimum operating temperature for the system.
[0013] In another embodiment, the metal or alloy is contained in an insulated container equipped with heat transfer elements or tubes that thermally communicate with the heat source. In this case, the system is charged by transferring heat from a high temperature gas circulating in a channel or passageway through a wall into the chamber containing the solid/liquid metal or alloy until it melts. The system is discharged by passing heat out of the chamber with the same or different heat transfer elements or tubes that communicate with the channel carrying the gas to be heated.
[0014] In any of the embodiments above, there is a wide choice of alloys to be used. In another embodiment two elements are combined to form an alloy with a melting temperature determined by the fraction of each metal present, which is in turn chosen by the desired operating temperature. In a particular embodiment, the alloy composed of aluminum and silicon is chosen. By varying the ratio of these elements the operating point may be chosen from about 600° C. to 1411° C. This very wide temperature range provides for the operation of a variety of turbine inlet temperatures including the upper range of Rankine steam cycles.
[0015] The tubes containing the metal or metal alloy in the first embodiment may be made from ceramic, metal, or clad graphite. The graphite must be clad in metal or ceramic in the case of air or other oxidizing gas (e.g., carbon dioxide) in the heat exchanger as otherwise the graphite would be subject to oxidation at the operating temperatures considered here.
[0016] In the embodiment using the heat transfer elements or tubes that transfer the heat to and from the metal enclosed in a separate insulated chamber, the tubes may be composed of solid metal of suitably high melting temperature e.g. copper, steel, nickel, or high temperature alloys of these or other metals. The elements may also be composed of graphite in direct contact with the molten metal if there is minimum chemical reaction with the heat storage metal or metal alloy, but with appropriate cladding in the sections that they may be exposed to an oxidizing atmosphere.
[0017] In another embodiment these heat transfer elements or tubes may also be closed hollow tubes composed of a high temperature metal ceramic or graphite containing a relatively small amount of an element or compound with a boiling temperature that is above that of the melting point of the metal or metal alloy storage material. In this case the element or compound is boiled within the lower end of the tube by the gas passing through the channel below the storage tank with the upper end imbedded in the metal or metal alloy storage material. This heat pipe arrangement is very effective as a heat exchanger. In this case the thermal storage is discharged by similar tubes, but that contain an element or compound with a lower boiling temperature than the melting point of the metal or metal alloy storage material. The lower end of the heat pipe is in the metal or alloy storage material while the upper end passes through the upper side of the storage chamber and into a separate gas carrying channel. In this case the storage is discharged by passing a gas through the upper channel.
[0018] There are several advantages to this form of latent heat storage. First, most of the heat is released at a constant temperature which allows a gas turbine to operate at its design point. This is a consideration as off-design operation of gas turbines can significantly lower their conversion efficiency. Charging the thermal storage is accomplished by the gas at any reasonable temperature above the melting point of the metal. Because all suitable metals and alloys contract on melting there is no reason for metals to break their containing tubes or storage containers. The high thermal conductivity of the metal in both liquid and solid form provides excellent heat transfer within the metal. This avoids problems encountered in using liquid salts or alkali metals wherein low conductivity regions of the solid and solidifying material slow the release of heat.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The foregoing aspects and others will be readily appreciated by the skilled artisan from the following description of illustrative embodiments when read in conjunction with the accompanying drawings.
[0020] FIG. 1 a is a schematic illustration of the top view of an embodiment of the a heat exchanger of an embodiment of the invention.
[0021] FIG. 1 b is a schematic illustration of the side view of an embodiment of a heat exchanger of an embodiment of the invention.
[0022] FIG. 1 c is a schematic illustration one of the tubes containing the metal or metal alloy of an embodiment of the invention.
[0023] FIG. 1 d is a schematic of an embodiment of the invention using a vertical flow configuration wherein the gas is moving parallel to the alignment of the storage tubes.
[0024] FIGS. 1 e and 1 f depict alternative embodiments of the tubes of the invention.
[0025] FIG. 2 is a schematic of another embodiment of the invention showing the charging plenum at the bottom and the discharging plenum above the metal or metal alloy storage container.
[0026] FIG. 3 a is a schematic illustration how an embodiment of the invention is implemented with a gas turbine generator in solar only mode.
[0027] FIG. 3 b is a schematic illustration how an embodiment of the invention is implemented with a gas turbine generator during thermal discharging.
[0028] FIG. 3 c is a schematic illustration how an embodiment of the invention is implemented with a gas turbine generator during hybrid operation wherein power for the turbine is supplied from storage and the solar receiver.
[0029] FIG. 4 is an equilibrium diagram for the Al—Si system showing metastable extensions of liquidus and solidus line.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] The embodiments of the invention are illustrated in the context of a Brayton cycle solar thermal electric power plant. The skilled artisan will readily appreciate, however that the materials and methods disclosed herein will have application in a number of other contexts where high temperature thermal storage is desirable.
[0031] One embodiment of the invention, also know as a Liquid Metal Thermal Storage system (LIMETS) consists of substantially four items ; the metal or metal alloy thermal storage material, the tubes or a compartment containing the metal or metal alloy, the insulated cavity enclosing the tubes, and the heat transfer medium (gas). FIG. 1 a is a top view of a schematic drawing of the system showing the insulated cavity 100 , the ceramic or clad graphite tubes 101 containing the metal or metal alloy and the insulated container 102 . FIG. 1 b is a side view of the same components. FIG. 1 c is a cross sectional view of the tube and metal showing one tube 101 and metal 103 with the open top. FIG. 1 d depicts a perspective view of this embodiment. By way of example only, tubes 101 can include fins or other appendages or structures that increase the surface area of the tubes and the rate of heat transfer to and/or from the tubes ( FIG. 1 e ). The tubes also have cross-sections that increase the rate of heat transfer ( FIG. 1 f ). Such cross-sections increase the surface area of the cross-section by including, for example, a star-shaped cross-section. The tubes and enclosure are to be arranged so as to maximize the heat transfer considering the temperature and nature of the gas transfer medium. The Reynolds number is determined by the properties of the gas and the characteristic dimensions of the tubes and the design should be optimized for these factors to maximize the heat transfer to and from the tubes.
[0032] FIG. 2 illustrates another embodiment utilizing the tubes. A vertical orientation of the tubes is useful so as to utilize the down corner from the solar receiver located at the top of tower and to provide an alternative design to optimize the heat transfer to the tubes. Ducting arrangements can allow flow of the gas in either up or down past the vertical tubes. In both of these arrangements the system is charged by passing hot gas from the solar receiver over the tubes until melting takes place. Since most metals and metal alloys expand when melting the lower density melt will rise to the top, leaving the bottom to melt last. This has a consequence of encouraging good mixing to ensure that the metal or metal alloy is nearly isothermal. In this embodiment the metal or metal alloy 104 is contained in a separate insulated container 105 that thermally communicates to the heated air via either high conductivity metal or metal clad graphite rods, or preferably by using hollow heat pipes or tubes 106 and 107 . In this embodiment there are two channels, one channel 108 for the hot (charging) gas below the metal or metal alloy container and one channel 109 above. The hot gas passes through the lower channel 108 and the heat pipes or tubes or rods 106 and carry the heat to the metal or metal alloy to melt the storage material 104 . To discharge the storage, a similar set of heat pipes or tubes or rods 107 carries the heat to the upper channel when cooler gas is pumped through the upper channel. The heat transfer may be substantially improved by using heat pipes in which an element or compound with a suitable boiling point is encapsulated within the tubes. As an example only, such element or compound can include potassium that may be used from about 500° C. to 1000° C., sodium from 500° C. to 1000° C., and lithium from 900° C. to 1700° C.
[0033] Because heat pipes carry heat most efficiently in an upward direction, in this embodiment there are two sets 106 and 107 . The element or compound within the lower pipes or tubes 106 is preferably chosen to have a operating point above the melting temperature of the metal or metal alloy storage material. The element or compound within the upper pipes or tubes 107 is preferably chosen to have a operating point below the meeting temperatures of the metal or metal alloy storage material.
[0034] The hot gas passing through the lower channel heats the lower end of the tubes and the element or compound in the tubes vaporizes and moves upward and condense at the cooler end in the storage material. When the storage material has melted and heat is needed to run a turbine, the gas to be heated is pumped through the upper channel. The upper heat pipes contain an element or compound that has an operating temperature below that of the melting temperature of the storage material. Therefore, when cooler air is pumped through the upper channel, the element or compound in the upper heat pipes condenses on the upper end transferring the heat to the gas to operate the turbine. The heat transfer is controlled by the flow of gases, moving upwards when heat is needed. There is an added advantage to this heat pipe system because the upper and lower channel may be at different pressures and the storage material need not be in a pressure container. Thus the system can take heat from air at ambient pressure, store the heat and discharge the heat at a convenient pressure for gas turbine operation.
[0035] The choice of the metal or alloy rod or tube is determined by, for example, 1) the melting temperature, 2) latent heat of fusion, 3) heat conductivity, 4) its viscosity and thermal convection characteristics, 5) expansion and contraction upon phase change, 5) chemical reactivity with containment and heat transfer elements and 6) effects of contaminants. For any given application, the melting temperature may be determined by the choice of metal, or be more finely tuned by the selection of alloy. Other considerations include crystallite size, effects of contaminates and alloy separation during the solidifying or freezing and re-melting. Another consideration is the price of the metal or metal alloy in current metal markets and what its future price will be at the decommissioning of the plant as this is likely to represent a significant investment.
[0036] Pure non-alkali metals that may be used for thermal storage include aluminum (m.p. 660° C., I.h. 95 cal/gm), copper (m.p. 1084° C., I.h. 49 cal/gm), iron (m.p. 1536° C., I.h. 65 cal/gm), and magnesium (m.p. 650° C., I.h. 88 cal/gm) (m.p. =melting point, I.h.=latent heat). The other pure metals have impractically high or low melting temperatures, are rare, expensive, radioactive, or toxic. However, alloys of the above mentioned and other metals form a very large class of possible alternatives for thermal storage materials. One reason for this is that two metals with differing melting temperatures often form a eutectic mixture when melted together that has a lower melting point than either metal by itself. Sometimes these effects can significant lower the melting point in a range of materials that could be useful for new metal alloy storage materials.
[0037] Another embodiment of the invention includes the specific choice of aluminum and silicon as a thermal storage material. Silicon is a common component of aluminum alloys; particularly at the composition of AlSi12 (approximately 88% aluminum and 12% silicon with a small amount of impurities such as iron). This is a particularly advantageous combination of materials, because of the physical properties resulting therein. While aluminum has a melting point of about 660° C., and silicon has a melting point of 1411° C., the melting point at the eutectic mixture of AlSi12 is about 600° C. Thus, it can be seen that by varying the composition, the melting point of the resulting alloy ranges from 600° C. at the eutectic point to 1411° C. for a pure Si composition. This is illustrated in FIG. 4 which depicts a graph of melting temperatures vs. compositions. This is a very wide and convenient range for high temperature latent heat storage materials.
[0038] There is another beneficial advantage of this combination of materials. While the latent heat of aluminum is relatively quite high at 95 cal/gm compared to other metals, the latent heat of fusion of silicon is amongst the highest known at 430 cal/gm. For example, it can be seen from the figure that at approximately a 50-50 atomic percentages, the melting temperature of the mixture is about 1000° C. If a linear interpolation between the latent heats of fusion of aluminum and silicon is used, the latent heat of the resulting mixture is about 263 cal/gm. This may be compared to value for sodium which has been used for a latent heat storage medium at 27 cal/gm. (about 1/10th that of the mixture—requiring 10 times the storage mass). Other potential storage materials include zinc with a latent heat of fusion of 27 cal/gm, copper at 49 cal/gm or lead of 5.5 cal/gm. Thus, it can be seen that there is a very substantial reduction in required material in using the AlSi combination.
[0039] Another advantage of the combination of silicon and aluminum is the relatively low cost of these materials in the industrial grades sufficient for this purpose compared to other metals with suitable melting temperatures.
[0040] Yet another consideration is the selection of the containment tubes. The size and shape of the tubes should be chosen to maximize the heat transfer with the gas and optimize the melting rates and patterns of the enclosed metal. In some circumstances radial or axial fins can be added to improve heat transfer to the tubes. High temperature ceramic materials are suitable because of the high melting temperatures of the metals involved (600-1200′ C.). However, certain high temperature alloy tubes may be considered for containment in the lower part of that temperature range. Another choice of materials is graphite. Graphite has high thermal conductivity and low reactivity with aluminum as discussed by Simensen and is widely used in aluminum refining for electrodes and containment materials. However, graphite may not be used in the presence of oxidization gases such as air or carbon dioxide because it will oxidize to carbon dioxide and fail as a containment or heat transfer means. The graphite may be clad with metals or ceramics to prevent its oxidation. The choice of the tube material should be guided by the desired operating temperatures and potential metal—containment tube interactions. The tubes may be closed or open depending on the choice of gas and metals. If air is the heat transfer medium the tubes should be closed to eliminate possible oxidation or other reactions between the metal and the components of the air. If helium, nitrogen or carbon dioxide is used the tubes may be open at the top if there are no interactions between the metal and gasses. For other gasses the potential interactions must be taken into consideration.
[0041] To illustrate the operation of a liquid metal thermal storage system embodiment of the invention in conjunction with a heat source and turbine, an embodiment of the overall system is illustrated in FIGS. 3 a , 3 b , and 3 c . FIG. 3 a illustrates the components of the system without the heat storage system 111 being connected or in the “pure solar” mode Air enters the turbo compressor 112 and is compressed before arriving at the heat source 113 . This may be a high temperature solar receiver heating a gas by direct or indirect of absorption of sunlight or a non-solar high temperature heat source. Further, the heat source 113 can be a windowed high temperature solar receiver that uses small particles to absorb concentrated sunlight 116 and heats the gas in which they are entrained. An example of such a receiver is discussed in “Solar Test Results of an Advanced Direct Absorption High Temperature Gas Receiver (SPHER),” by
[0042] A. J. Hunt and C. T. Brown, Proc. of the 1983 Solar World Congress, International Solar Energy Society, Perth, Australia, Aug. 15-19, 1983, LBL-16947, and “Heat transfer in a directly irradiated solar receiver/reactor for solid-gas reactions” by Klein, H. H., Karni, J., Ben-Zvi, R. and Bertocchi, R. Solar Energy 81 (2007) 1227-1239. which are incorporated herein by reference. After being heated to a high temperature the gas is routed into the expansion turbine 114 that provides power to run the compressor and turn the generator 115 before being exhausted or recycled. FIG. 3 b illustrates the arrangement for charging the storage wherein all the gas is routed through the storage system before passing through the expansion turbine. FIG. 3 c illustrates operation of the system in “hybrid” mode in which the gas is selectively routed both through the storage and through the turbine, in parallel, adjusted with the controlling valves 117 and 118 . Valve 117 can divert gasses directly to the solar receiver or heat source 113 (for the operation of the embodiment of FIG. 3 a ) or directly to the heat storage system 111 for the operation of the embodiment of FIG. 3 b ). Valve 118 can divert gasses to the heat storage system 111 or to the expansion turbine 114 . Various positions of the valves 117 and 118 can allow the expansion turbine 114 to run directly on energy provided by the receiver or heat source 113 , or alternatively on energy provided by the heat storage system 111 , or both.
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Embodiments of this invention relate generally to high temperature thermal energy storage, and more specifically, to the use of the latent heat of fusion of melting and solidifying metals to receive from and provide heat to a gaseous medium. Embodiments of this invention are also known as the Liquid Metal Thermal Storage system or LIMETS. Also described are methods of containing the storage material, heat transfer means, and choices of metals and alloys for thermal storage materials.
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CROSS REFERENCE TO RELATED APPLICATIONS
The present application is a National Phase Application of International Application No. PCT/AU2005/001618, filed Oct. 19, 2005, which claims priority to Australia Patent Application No. 2004906085 filed Oct. 20, 2004, which application is incorporated herein fully by this reference.
FIELD OF THE INVENTION
The present invention relates to an authentication method that allows a personal mobile terminal to authenticate an action.
BACKGROUND TO THE INVENTION
There are a large number of instances where it would be desirable to provide an improved method for a user to authenticate an action. Currently there is a potential security problem in any system which requires a user to log in to a web server by providing a user name and password. Such systems rely on the password being something that the user alone knows. However, the password can be compromised, for example, by so-called “phishing” where a user is tricked into providing their password to a party that is not entitled to the password by getting the user to visit a bogus website and enter their name and password.
It has recently become more popular to employ “2-factor” security techniques which rely on their being something that the user alone has in their possession as well as something the user alone knows. A typical device which is used in such systems is a token that generates a unique code every 60 seconds thereby creating what is in effect a new secondary password every 60 seconds. To defeat such a security measure the person must either obtain the person's password and their security device or learn the secondary password during the very short period of time where it is valid. Accordingly, such devices provide a higher level of security.
A first problem with such devices is that if the person does not carry out all transactions from the same location they must carry the token with them which can be inconvenient. Further, the tokens are typically configured so that they can only act as a secondary password to one additional system. Thirdly, if the user does not use the device regularly, they can readily misplace the token. Fourthly, the tokens can be difficult to distribute. Fifthly, as specific hardware has to be provided for the secondary password, the cost of such tokens is relatively high and accordingly is only attractive to employ them in relation to high security risk transactions or when the potential damage that may be suffered is high.
WO 03/063411 proposes a system which produces an SMS message containing a limited-duration, one-time password and sends it to a user's mobile terminal. A modified Subscriber Identification Module (SIM) is used to store an asymmetric key application and associated software. The user activates the program, enters a personal code to decrypt the user's private key which thus authorises the mobile terminal to decode the SMS using the user's private key. A problem with this system is that it relies on the distribution of specific hardware to the user. Further, as the keys are on the SIM, distribution is dependent on the telecommunications provider. Still further, the one-time password will not contain any data that indicates that it has been decoded by the user i.e.—the one-time password is independent of the user.
It would be desirable to provide a more convenient method of authenticating an action.
SUMMARY OF THE INVENTION
In one aspect, the invention provides an authentication method comprising requesting a user of a personal mobile terminal to enter a personal code into a personal mobile terminal in response to receipt of an authentication request transmitted to the personal mobile terminal, the authentication request being related to an action that requires user authentication, and processing an entered personal code together with challenge data corresponding to the authentication request to determine whether one or more predetermined conditions are met and, if one or more predetermined conditions are met, producing a valid and signed authentication code that the user can provide in order to authenticate the action.
In an embodiment, challenge data is transmitted to the personal mobile terminal as part of the authentication request.
In another embodiment, the method comprises generating, at the personal mobile terminal, challenge data corresponding to at least part of the authentication request.
In an embodiment, at least one of the one or more predetermined condition is that the personal code is correct.
In an embodiment, the method comprises processing the entered personal code together with at least one key stored on the mobile phone.
In this embodiment, at least one of said one or more predetermined conditions is that the key is correct.
In an embodiment, details of the action are included in the authentication request, and the method comprises displaying the details of the action to the user before the user enters the user's personal code.
In an embodiment the transaction details are only displayed after the personal code is entered.
In another aspect, the invention provides a computer program that when executed by a personal mobile terminal enables the personal mobile terminal to request a user of the mobile terminal to enter a personal code following receipt of an authentication request transmitted to the mobile terminal, the authentication request being related to an action that requires user authentication, process an entered personal code together with a challenge corresponding to the authentication request, and produce a valid and signed authentication code that the user can provide in order to authenticate the action if one or more predetermined conditions are met.
In one embodiment the computer program enables a personal mobile terminal to process challenge data transmitted to said personal mobile terminal as part of said authentication request.
In an embodiment the computer program generates, at said personal mobile terminal, challenge data corresponding to at least part of said authentication request.
In an embodiment the computer program is executed by the personal mobile terminal upon receipt of the authentication request.
In an embodiment the computer program causes the personal mobile terminal to automatically provide the authentication code on the user's behalf after completion of processing of the personal code.
In another embodiment, the invention provides a personal mobile terminal configured to request a user of the mobile terminal to enter a personal code following receipt of an authentication request transmitted to the mobile terminal, the authentication request being related to an action that requires user authentication, process an entered personal code together with challenge data corresponding to the action data to determine whether one or more predetermined conditions are met, and produce a valid and signed authentication code that the user can provide in order to authenticate the action if the one or more predetermined conditions are met.
In another aspect, the invention provides an authentication method comprising transmitting an authentication request to a personal mobile terminal designated as belonging to a user in response to the initiation of an action that requires authentication by the user, receiving the authentication request at the personal mobile terminal, prompting a user to enter a personal code into the personal mobile terminal, processing the personal code together with challenge data corresponding to the authentication request and if one or more predetermined conditions are met, producing a valid and signed authentication code that the user can provide in order to authenticate the action.
The action may be a transaction initiated by the user or requiring authorisation by the user.
In an embodiment, the transaction is a banking transaction.
In an embodiment the transaction is an order for a product or service.
In another aspect, the invention also provides a system for authenticating actions comprising an action authentication server, and one or more personal mobile terminals belonging to respective ones of one or more users of the system, the action authentication server being configured to transmit an authentication request to a personal mobile terminal of a user in response to initiation of an action requiring authentication by a user, each users' personal mobile terminal being configured to request the user of the personal mobile terminal to enter a personal code following receipt of the authentication request, process an entered personal code together with challenge data corresponding to the authentication request, and produce a valid and signed authentication code that the user can provide in order to authenticate the action if one or more predetermined conditions are met.
The action authentication server is typically configured to receive the authentication code and authenticate the action if the authentication code is valid.
The invention also extends to a method of configuring a personal mobile terminal to participate in an authentication system comprising providing an activation code to a user by a means independent of the user's personal mobile terminal, placing a security application on a web server for retrieval by the user's personal mobile terminal, providing details of the security application to the user that are sufficient for the user to retrieve the security application, running the security application on the user's personal mobile terminal in order to prompt the user for the activation code and to generate a confirmation code if the activation code is entered into the personal mobile terminal, and providing the confirmation code to the authentication system, and activating the user if the confirmation code is valid.
In an embodiment, the confirmation code is provided by a means independent of the user's personal mobile terminal.
In an embodiment, the user initiates a configuration of the user's personal mobile terminal by accessing the web server.
In an embodiment, the security application is personalised for said user.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic diagram giving an overview of how the system of the preferred embodiment operates;
FIG. 2 is a schematic diagram illustrating how authentication request messages are handled by a computer program of the preferred embodiment operating on a personal mobile terminal;
FIG. 3 is a process flow diagram of a transaction of the preferred embodiment; and
FIG. 4 is a process flow diagram of a provisioning technique of a preferred embodiment.
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiment of the present invention provides a method of implementing a secure yet easy to use and deploy authentication method using personal mobile terminals such as mobile telephones. In the preferred embodiment the implementation is restricted to software that eliminates the need to issue or reissue any hardware to the user. The personal mobile terminal can then be used to authenticate an action. For example, to authenticate the user to a suitably enabled system or to authorise a payment to a suitably enabled payment system. In the preferred embodiment, the system allows a user to authenticate an action by entering a personal code such as a personal identification number (PIN) into their mobile phone.
Referring to FIG. 1 , there is shown schematically the general operation of a method of the preferred embodiment. A system that needs to authenticate an action 100 transmits an authentication request 110 to a user's mobile phone 120 . The mobile phone has been preconfigured with a security application that is run in software environment 121 of the mobile phone.
When the authentication request—e.g. a request to a transaction in an internet banking service—is received by the phone it is processed by the security application and a user is prompted to enter a PIN using keypad 123 . If the PIN is correct, details of the request are displayed on screen 122 . The PIN together with the authentication request are processed by the application 121 in order to generate a security related response 130 that can be supplied to the system with a security related 100 in order to authenticate the action.
The structure of the security application is shown schematically in FIG. 2 . An authentication request 200 is received from the system that requires an action to be authenticated. The request 200 may be optionally encoded using transport keys 210 which are processed before further action is taken by the security related request handler 220 . The request handler splits the authentication request into a data portion 221 and a challenge portion 222 . The challenge portion includes an encoded portion related to the action, for example the transaction data encrypted with a public key assigned to the user.
The data portion 221 is processed by the data display engine 230 which uses preset display schema to format output for display on the screen 232 . In the meantime, the data crypto engine 240 receives the input of the challenge 222 , the user's identification number (PIN) 241 and a user's private key 242 stored in the memory of the personal mobile terminal and processes them to produce an authentication code that is displayed on the screen or transmitted back to the system at step 243 . Persons skilled in the art will appreciate that any appropriate cryptographic algorithms such as 3DES or RSA can be used.
A typical transaction process flow where the method of the preferred embodiment is used to authenticate transactions of an Internet banking system is illustrated in FIG. 3 . In FIG. 3 , components of the system are labelled by numbers on the components whereas the process flows are indicated by numbers beside the system components or beside the arrows between the system components.
In the first step of the process 301 , the user operates their browser 20 typically running on a personal computer to log into their Internet banking website which is hosted by web server 40 by sending data over the Internet 30 . Details of a proposed transaction are posted to the web server at step 302 —e.g. a proposal to transfer $10,000. These details are then relayed to an Internet-banking system 50 at step 303 . At step 304 the Internet banking system confirms that the transaction is allowed. At step 305 the web server serves a new page to the browser for the user to enter an authentication code that is to be generated by the user's mobile phone 10 . At step 306 , the Internet banking system 50 sends a transaction authentication request to transaction authentication server 60 which constructs an authentication request including a cryptographic hash of the details and sends the authentication as a short message service message (SMS) on a preset port number at step 307 . At step 308 the SMS message launches the security application on the user's handset via the java community process standards JSR-118 MIDP-2.0 Push Registry implementation. The security application is a Java 2 Micro Edition (J2ME) java application that has been registered to listen on the preset port. At step 309 the user gives permission to run the security application and is prompted to enter their user PIN and the transaction details are displayed to them. At step 310 the security application then digitally signs the cryptographic hash using the PIN code and a private key stored on the personal mobile terminal to produce a unique numeric code that functions as an authentication code. As the code is using the user's private key, the authentication code can only be provided by someone having access to a personal mobile terminal having the user's software application and the user's PIN. At step 311 the user then having satisfied themselves that the transaction details displayed on the handset are correct enters the authentication code into the entry box on the webpage and submits the funds transfer request. The numeric code is sent at step 312 to the web server and relayed at step 313 to the Internet banking system. At step 314 it is passed to the transaction authentication server which is asked to validate the authentication code. The authentication server 60 replies at step 315 to indicate that the authentication code is correct. A funds transfer confirmation message is sent to the web server at step 316 and then passed to the browser at step 317 . At step 318 the security application automatically exits 60 seconds after displaying the authentication code.
Persons skilled in the art will appreciate that a number of minor variations can be made to the system for example, the transaction details need only be displayed in this embodiment to the user after they have entered their PIN as the user will know whether they have initiated a transaction and to confirm the transaction requires the further step of entering the authentication code into their browser before the transaction is final. However in embodiments where the message is transmitted automatically to an authentication server by the personal mobile terminal (e.g. by return SMS message), it would be advantageous for the user to approve the transaction details before entering the PIN and accordingly for them to be displayed to the user before the user enters their PIN.
Persons skilled in the art will appreciate that there are a number of advantages of the above method. For example, the expense of issuing or reissuing hardware is avoided. The user's existing compatible mobile phone may be used, provided it can run appropriate software applications. Further, the authentication code is specific to the user as it is generated using the user's private key—i.e. the authentication code is “signed”.
In the preferred embodiment the incoming security request efficiently and automatically launches the application thus making it easy for the user to use. It carries a challenge e.g. a random number to input into the cryptographic algorithm and it may carry a description of the service the user is to be authenticate to or the details of the payment to be authorised—generally, the details of the action which requires authentication.
The use of cryptographic algorithms such as 3DES and RSA ensure a high level of security. Additionally the personal nature of a mobile phone or similar device ensures that it is close to the user and its loss will be noted promptly unlike a security token. Because the software can be deployed readily over the air as will be described in further detail below, deployment costs are minimised. The software can also be deployed using infrared, Bluetooth or phone data cables.
Persons skilled in the art will appreciate that the technique of the preferred embodiment can either be deployed as standard authentication technique and licensed to a number of different parties or slightly different variations can be used for authorising different transactions. In this respect it will be appreciated that a number of similar but slightly different cryptographic processes can be applied using different keys in order to authenticate different services using the one mobile phone.
Persons skilled in the art will appreciate that the method may be used to authenticate a number of different actions including:
Authenticating any service offered via Internet and accessed by a personal computer. For example logging onto a government website to update sensitive personal details. Authorisation of phone orders. Authentication of network devices for services. For example authorising a wireless network connection for a personal computer.
A typical personal mobile terminal that will allow the system to operate is a mobile phone that supports a mobile information device profile (MIDP-2.0) as specified in the java community process standard JSR118, connected limited device configuration (CLDC-1.0) as specified in java community process standard JSR30 and wireless messaging API (WMA 1.1), as specified in java community process standards JSR 120. An exemplary phone that complies with these standards is a Nokia 6230. The application is written in J2ME-JSR68 and the security related message can be a GSM SMS message as described by the ETSI organisation in GSM 03.40 and GSM 03.38.
The SMS message is encoded in Protocol Description Unit (PDU) mode, in which a destination port number can be assigned in addition to the destination mobile phone number so that the application can be registered on a specific port number.
A preferred embodiment for configuring a user's mobile phone so that they can utilise the above method to authenticate an action will now be described in relation to FIG. 4 . Referring to FIG. 4 , registration is initiated by a user who wishes to take advantage of this system by registering their mobile phone number with the institute with which they wish to use the authentication technique, in this example a bank. At step 401 the user is sent an initial activation code using a technique such as a personal identification number mailer 70 so that the activation is sent to an address that is already registered with the bank so that the bank can have a high degree of surety that the PIN has been sent to the correct person. At step 402 the user uses their browser 20 to log into their Internet banking system 50 via web server 40 over Internet 30 . The user then starts the application provisioning process by pressing an appropriate button on the web page. The user's request to start the provisioning process is posted to the web server 40 at step 403 . The request is then relayed to the Internet banking system 50 at step 404 .
The Internet banking system confirms that provisioning is allowed at step 405 and at step 406 the web server serves a new page to the user's browser 20 . The new page contains an entry box for the user to enter a confirmation code that will be generated by the user's handset later in the provisioning process. The Internet banking system 50 sends a provisioning request to the transaction authentication server 60 at step 407 . At step 408 the transaction authentication server 60 places a user application customised to the user with appropriate keys on the web server 40 for retrieval by the user's personal mobile phone 10 . At step 409 the transaction authentication server 60 also sends a WAP Push service message to the user's personal mobile phone 10 with the name of the application and a web address. At step 410 the user gives permission to their handset to retrieve the application over the air (OTA) using Wireless Application Protocol (WAP) at step 410 .
At step 411 the handset retrieves the application over WAP, and registers the application with the Push Registry for the preset port number. At step 412 the user gives permission to run the application. At step 413 the application prompts for the activation code and the user enters the activation code that they received from PIN mailer 70 at step 401 . The user is then prompted to select and confirm their own personal identification number (PIN) for all future use. The application cryptographically calculates a unique confirmation code based on the initial activation code and the user's keys and it is displayed to the user at step 414 . At step 415 the user enters the confirmation code into the web page and submits the details to the web server 40 at step 416 . At step 417 the confirmation code is relayed to the Internet banking system 50 . The Internet banking then sends the message to transaction authentication server 60 at step 418 and asks that the user state be set to “provisioned” provided the confirmation code is verified as correct. At step 419 the transaction authentication server asks that the user application be deleted from the web server. At step 420 the Internet banking service notes that the user has been successfully provisioned and that their application is functioning correctly on their handset and sends and accepted message to the web server. The web server presents a “You are now operational” message to the user at step 421 and at step 422 the application exits are, typically 60 seconds after displaying the unique confirmation code.
Persons skilled in the art will appreciate that alternative environments may be used to implement the preferred embodiment. For example, the application could be a .Net security application running in the Windows Mobile 2003 Second Edition for Smart phones environment.
There are a number of specific variations to the above embodiment which can be employed while still obtaining some or all of the benefits of the above embodiment. In one embodiment, rather than the challenge data being contained within the security related request message 200 , the challenge can be generated at the personal mobile terminal from the transaction data sent to the mobile terminal. That is, generated at a handset rather than the server. (This transaction data can still be encrypted with transport keys between the server and handset.)
Persons skilled in the art will appreciate that the term “challenge data” is used herein to refer to the actual challenge data that is processed. In this embodiment, the authentication request will still include a “challenge portion” in the sense that at least a portion of the data in the authentication request is intended to be used to form challenge data. The difference in this embodiment is that instead of the challenge data being a separate part of the authentication request that is not displayed (i.e. which was solely for input to the data-crypto engine), data relating to the actual transaction is used as the basis for the challenge data. This ties the data displayed to the user to the generated authentication code (in addition to the user's keys coupling the authorisation to the user).
The display of data to the user means the user knows precisely what they are authorising/signing. If the other channel is compromised (e.g. a man in the middle attack between the Internet Browser and the Internet Server modifies the amount or account number), the user will see and catch this on the handset display allowing intervention. A system whereby only encrypted passwords are transmitted/generated does not protect against this type of attack.
The action data is typically displayed to the user and then hashed, for example, using SHA-1. A “sequence” number is stored on the personal mobile terminal. The sequence number is added to the data before the hashing function is performed and the sequence number is incremented after each authentication code generation on the handset. At the server end, the last matched sequence number is stored for each handset. When attempting to verify an authentication code, the sequence number is incremented (within a preset limit) until a match is found. It will thus be appreciated that as in the above embodiment, the authentication code is in effect signed by the user as it is personalised to the user. The sequence number is a convenient method of preventing playback attack. A set of challenge/responses will only be verified once as the server will only accepted authentication codes that validate with the current or greater sequence number.
It will also be appreciated by persons skilled in the art that the person who authorises the transaction does not have to be the person who initiated the action. For example, a company could arrange their affairs such that all requests for transfers of funds above a certain dollar value have to be approved by Chief Financial Officer. They can achieve this without needing the Chief Financial Officer (CFO) to be in the office. For example, an administrative officer can initiate the transaction request which will result in the system sending a message to the personal mobile terminal of the CFO providing payment summary details. The CFO can then authorise the payment. This can be returned automatically via SMS.
Persons skilled in the art will also appreciate that it would be possible to enforce multiple authorisations before a request is executed utilising the system of the preferred embodiment. For example, two approvals may be required to transfer funds above certain balances. These may need to be received sequentially—i.e. a first approval is received prior to the second authentication request being sent—or in parallel—i.e. requests are sent contemporaneously to two parties.
Further, rather then using the PIN mailer 70 as indicated in FIG. 4 , the activation code could be returned to the user electronically (e.g. displayed in their browser when they start the provisioning process). A further security element that could be incorporated is to implement a time out on the server side, for example five minutes after the request SMS is sent. This is particularly useful in the embodiments where the user is expecting the authentication request and reduces the exposure to risk, for example, if they have mislaid their mobile terminal.
Persons skilled in the art will appreciate that further security measures may be incorporated. For example, mobile terminal specific data, where available, may be incorporated into the confirmation code and all authentication codes. This helps protect against application cloning—i.e. where someone copies the application code and memory from the mobile terminal and runs it on a different mobile terminal type or emulator. Unless they collect or know the mobile terminal specific data, the activation code generated by the different mobile terminal or emulator will be incorrect.
Persons skilled in the art will appreciate that in specific embodiments the authentication code can be provided in a number of other ways. For example, if the authentication code is used to authenticate a transaction over the phone, the authentication code can be read out by the user or entered into a telephone key pad (either of the user's mobile terminal or another telephone). In order to assist disabled users, it would also be possible to modify the computer program to incorporate a speech synthesis sub-routine so that following entry of the user's PIN, the personal mobile terminal could “read out” the authentication code on the user's behalf either automatically or after it is instructed to do so.
Persons skilled in the art will appreciate that various other modifications may be made to the above invention without departing from the scope and spirit of the inventions described herein.
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There is disclosed an authentication method comprising requesting a user of a personal mobile terminal to enter a personal code into a personal mobile terminal in response to receipt of an authentication request transmitted to the personal mobile terminal, the authentication request being related to an action that requires user authentication, and processing an entered personal code together with challenge data corresponding to the authentication request to determine whether one or more predetermined conditions are met and, if one or more predetermined conditions are met, producing a valid and signed authentication code that the user can provide in order to authenticate the action.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of application Ser. No. 08/669,804 filed Jun. 27, 1996 which is now abandoned and which is a continuation of application Ser. No. 08/370,749 filed Jan. 10, 1995, which is now abandoned.
FIELD OF THE INVENTION
The invention is directed to an improved process for making copper I oxide (Cu 2 O) powders. In particular, the invention is directed to a process for making such powders that are fully dense, single phase, with high purity, spherical morphology and controlled particle size distribution.
BACKGROUND OF THE INVENTION
In thick film conductor systems, copper I oxide is used to promote adhesion to substrates. Copper I oxide powder is added to form chemical or reactive bonds with the substrate, thereby enhancing the adhesion of the conductor.
Known methods of manufacture of copper I oxide involve the furnace reduction of mixtures of copper oxides and copper, the electrolytic process involving plating copper I oxide from an alkaline sodium solution using copper electrodes, or reducing alkaline solutions of copper II salts. These inherently do not produce phase pure copper I oxide. Some copper II oxide is present. This copper II oxide impurity dilutes the efficacy of the copper I oxide and can degrade the solderability of thick film conductors. In addition, these processes are not easily controlled and, therefore, are not found to produce materials with uniform particle size, spherical shape and fully dense, all of which are very important in the improvement in the properties of thick film pastes.
With increasing circuit complexity and decreasing feature sizes, thick film pastes must be composed of pure and chemically uniform particles with very well controlled particle size distributions. Spray pyrolysis has emerged as a promising technique for the production of pure, fully dense, spherical powders with compositional homogeneity at the molecular level with a uniform particle size. Also, the invention may be produced at a lower temperature which produces pure, spherical powders with uniform particle size.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a TEM photograph at magnification of 40,000× of copper I oxide that depicts a not fully dense particle.
FIG. 2 is a TEM photograph at magnification of 100,000× of copper I oxide that depicts a fully dense particle.
FIG. 3 is an experimental apparatus used for spray pyrolysis.
FIG. 4 is an X-ray diffraction of Example 3 from Table 1 showing copper II oxide.
FIG. 5 is an X-ray diffraction of Example 6 from Table 1 showing copper I oxide.
FIG. 6 is an X-ray diffraction of Example 5 from Table 1 showing a mixture of copper I oxide and copper II oxide.
SUMMARY OF THE INVENTION
The invention is directed to a method for the manufacture of fully dense, finely divided, spherical particles of copper I oxide (Cu 2 O) comprising the sequential steps:
A. forming an unsaturated solution of a thermally decomposable copper containing compound in a thermally volatilizable solvent wherein the copper containing compound is used in concentrations not below 0.002 mole/liter or not higher than 90% of saturation and wherein particle size of copper I oxide is an approximate function of the cube root of the concentration of the unsaturated solution;
B. forming an aerosol consisting essentially of finely divided droplets of the solution from step A dispersed in an inert carrier gas, the droplet concentration being below the concentration where collisions and subsequent coalescence of the droplets results in a 10% reduction in droplet concentration and wherein the particle size distribution of copper I oxide is a direct function of the droplet size distribution;
C. heating the aerosol, (1) to an operating temperature of at least 1000° C. but below the decomposition temperature of copper I oxide, (2) at a rate such that the droplets do not explosively burst, and (3) with sufficient residence time; wherein (a) the solvent is volatilized, (b) the copper containing compound is decomposed to form the copper II oxide (CuO), (c) the copper II oxide is decomposed to form pure phase copper I oxide (Cu 2 O), and (d) the copper I oxide is fully densified; and
D. separating the fully dense, spherical particles of copper I oxide from the carrier gas, reaction by-products and solvent volatilization products. The invention is further directed to a method for the manufacture of finely divided, spherical particles of copper I oxide (Cu 2 O) with controlled particle size distribution wherein the method is as described hereinabove with the exception of the operating temperature found in step C being at least 800° C. but below 1000° C.
DETAILED DESCRIPTION OF THE INVENTION
Copper Containing Compound
Any soluble copper salt can be used in the method of the invention so long as it is inert with respect to the carrier gas used to form the aerosol. Examples of suitable salts are cupric nitrate, cupric sulfate, cupric formate, and cupric acetate. Insoluble copper salts are not suitable. The copper containing compound may be used in concentrations as low as 0.002 mole/liter and upward to just below the solubility limit of the particular salt such that the salt does not precipitate while in solution. It is preferred not to use concentrations below 0.002 mole/liter or higher than 90% of saturation.
While it is preferred to use water-soluble copper salts as the source of copper for the method of the invention, the method can, nevertheless, be carried out effectively with the use of other solvent soluble compounds such as organometallic copper compounds dissolved in either aqueous or organic solvents.
Operating Variables
The method of the invention can be carried out under a wide variety of operating conditions so long as the following fundamental criteria are met:
1. The concentration of the copper containing compound should be at least 10% below the saturation concentration in order to prevent precipitation of solids before removal of the liquid solvent;
2. The concentration of the droplets in the aerosol must be sufficiently low so that it is below the concentration where collisions and subsequent coalescence of the droplets results in a 10% reduction in droplet concentration causing significant broadening of size distribution.
Though it is essential to operate under the saturation point of the copper containing compound, the concentration is not otherwise critical in the operation of the process. Much lower concentrations of the copper containing compound can be used. However, it will ordinarily be preferred to use higher concentrations to maximize the mass of particles that can be made per unit of time. The concentration will determine the resulting size of the copper oxide particle. The higher the concentration of copper containing compounds in the droplet, the more mass in the droplet and the subsequent increase in the size of the particle. In addition, particle size is an approximate function of the cube root of the concentration. If a greater change in particle size is needed, a different aerosol generator must be used.
Any conventional apparatus for droplet generation may be used such as nebulizers, collision nebulizers, ultrasonic nebulizers, vibrating orifice aerosol generators, centrifugal atomizers, two-fluid atomizers, electrospray atomizers and the like. The particle size distribution of the powder is a direct function of the distribution of the droplet sizes generated. Therefore, the overall particle size distribution is dependent on the generator chosen for the process.
Virtually any carrier gas which is inert with respect to the solvent for the copper containing compound and with respect to the compounds themselves and the copper I oxide powder may be used. Examples of suitable carrier gases are nitrogen, argon, helium, and the like.
The temperature range over which the method of the invention can be carried out is quite wide and ranges from the decomposition temperature of copper II oxide (about 800° C. in N 2 ) to the decomposition temperature of the copper I oxide (approximately 1400° C.) although below 1235° C. is the preferred operating temperature. This invention allows for the production of spherical, phase pure, copper I oxide at a temperature of 800° C. which is significantly below the melting point of copper I oxide. In addition, by operating at temperatures above 1000° C., fully dense, spherical, phase pure copper I oxide powder can be produced. Fully dense herein means devoid of hollow spaces.
The type of apparatus used to heat the aerosol is not by itself critical providing the apparatus does not cause bursting of the droplets. An example of such apparatus is a tube furnace.
The evolution of particle morphology depends to a large extent on the rate at which solvent evaporation occurs from a droplet. The aerosol droplets from which the product particles evolve do not burst or rupture during any part of the process. The possibility of the bursting of droplets is precluded by sending the aerosol droplets through an initial zone in a furnace whereby the temperature of a droplet gradually rises to the final temperature. This zone provides an environment for controlled evaporation of the solvent in the droplets and thereby prevents them from rupturing due to explosive release of solvent vapor. The resultant powder particle size and particle size distribution is dependent not only on solution concentration and droplet size distribution but also on gradual rise in temperature during the heating step.
Upon reaching the reaction temperature and maintaining the temperature for a residence time which causes the full densification of the particles, the particles are separated from the carrier gas, reaction by-products and solvent volatilization products and the powder is collected by one or more devices such as filters, cyclones, electrostatic separators, bag filters, filter discs, and the like. The by-products generated upon completion of the reaction consists of the carrier gas, decomposition products of the copper containing compound, and solvent vapor. Thus, in the case of preparing copper I oxide from aqueous copper nitrate using N 2 as the carrier gas, the by-products generated from the method of the invention will consist of nitrogen oxide(s), water, and N 2 gas.
Test Apparatus
The experimental apparatus used in the Examples is shown in FIG. 3. A source of carrier gas supplies the N 2 through the regulator and gas flow meter. The carrier gas flow rate determined the residence time of the aerosol in the reactor. The aerosol was produced using a modified BGI Collison CN - 25 generator and the reactor was a Lindberg 3-zone furnace with a 91 cm. heated region. A 152 cm. Coors mullite reactor tube (9 cm. O.D., 8 cm. I.D.) was used. The powders were collected on a membrane filter supported by a heated stainless steel filter holder. The filter was a Tuffryn membrane filter (142 mm dia., 0.45 micron pore dia.) supported on a Gelman 147 mm dia. filter holder.
Copper Nitrate Solution
In the Examples which follow, the copper nitrate solution used for the production of the copper oxide powder samples was prepared by the following procedure:
1. Add 79.55 g of 99.99% pure copper II oxide to a beaker.
2. Slowly add 180 g of nitric acid (70% by weight) to the copper II oxide powder.
3. Gently heat and stir the mixture for several hours until all the powder has dissolved to produce a blue solution.
4. Slowly add additional copper II oxide powder until some of the powder remains undissolved.
5. Filter the solution to remove undissolved powder.
6. Dilute the solution to desired molarity.
Sixteen process runs (Examples 1-16) were performed in which the method of the invention was demonstrated. The operating conditions of these runs are shown in Table 1 and 2 along with the selected properties of the copper oxide particles produced thereon.
EXAMPLES
Examples 1-4 indicate that copper II oxide is produced at temperatures at or below 700° C. in nitrogen. These particles are not fully densified. As the temperature is increased, the particles become more crystalline as indicated by the narrowing of the x-ray diffraction peaks. Transmission electron microscopy (TEM) indicate that the particles are not fully dense and contain some hollow and void spaces as depicted in FIG. 1.
Examples 5 and 6 indicate that at 800° C. in nitrogen, pure phase copper I oxide can be produced if the residence time is long enough. Example 5 was made with a residence time of 3.0 sec. and was found to contain a mixture of Cu I oxide and Cu II oxide as shown by x-ray diffraction. Increasing the residence time to 5.1 sec. (example 6) produced phase pure Cu I oxide. Example 6 powder was found to not be fully dense as indicated by void spaces.
Examples 7-9 indicate that at temperatures of 1000° C. or higher, fully dense, phase pure, spherical copper I oxide powder is produced. Below 1000° C., some of the particles (not all) are not filly dense and still have some void spaces in them as shown by FIG. 1.
Examples 10-11 indicate that using the inert gas argon as the carrier gas produces similar results to that reported using nitrogen gas.
Examples 12-14 were made using air as the carrier gas which is not inert to this system. These examples show that at temperatures between 800° C. and 1200° C., the resulting product is copper II oxide. At 1200° C., a mixture of copper I oxide and copper II oxide was obtained as shown by x-ray diffraction. The oxygen in the air keeps the copper oxide oxidized to the +2 state until the high temperature of 1200° C. where the copper II oxide decomposes partially to Cu I oxide.
Examples 15 and 16 indicate that the particle size distribution is not dependent on the temperature or the flow rate. Examples 15 and 16 had the same concentration and were made using the same aerosol generator resulting in both examples having the same narrow particle size distribution with an average size of about 1 micron. Particle size distribution was measured using a Leeds and Northrup Microtrac II® 7998 SBA.
TABLE 1__________________________________________________________________________Copper Flow Residencenitrate Temperature Carrier rate time X-ray DensityExamplemole/1 °C. gas 1 pm sec. diffraction TEM__________________________________________________________________________1 1.0 400 N.sub.2 7.79 7.0 CuO not dense2 1.0 500 N.sub.2 7.79 6.0 CuO not dense3 1.0 600 N.sub.2 6.04 6.9 CuO not dense4 1.0 700 N.sub.2 6.04 6.2 CuO not dense5 1.0 800 N.sub.2 11.36 3.0 Cu.sub.2 O, CuO mixture6 1.0 800 N.sub.2 6.62 5.1 Cu.sub.2 O not dense7 1.0 900 N.sub.2 5.45 5.8 Cu.sub.2 O not dense8 1.0 1000 N.sub.2 9.55 3.0 Cu.sub.2 O dense9 0.5 1200 N.sub.2 9.55 2.6 Cu.sub.2 O dense10 1.0 800 Ar 7.79 5.2 Cu.sub.2 O not dense11 1.0 1200 Ar 9.55 3.0 Cu.sub.2 O dense12 1.0 800 air 7.79 5.2 CuO not dense13 1.0 1000 air 9.55 3.6 CuO not dense14 1.0 1200 air 7.79 3.8 Cu.sub.2 O, CuO mixture__________________________________________________________________________
TABLE 2__________________________________________________________________________Copper Flow ResidenceNitrate Temp. Carrier Rate Time d.sub.10 d.sub.50 d.sub.90Examplemole/1 °C. gas 1 pm sec. microns microns microns__________________________________________________________________________15 0.5 900 N.sub.2 7.2 9.4 0.52 1.12 2.6416 0.5 1150 N.sub.2 6 9.4 0.44 1.05 2.62__________________________________________________________________________
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The invention is directed to a method for the manufacture of fully dense, finely divided, spherical particles of copper I oxide with controlled particle size distribution. The invention is further directed to a method for the manufacture of finely divided, spherical particles of copper I oxide with controlled particle size distribution.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not Applicable
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH
[0002] Not Applicable
BACKGROUND OF THE INVENTION
[0003] Stents, grafts, stent-grafts, vena cava filters, vascular implants, and similar implantable medical devices, collectively referred to hereinafter as stents, are radially expandable endoprostheses which are typically intravascular implants capable of being implanted transluminally and enlarged radially after being introduced percutaneously. Stents are typically mounted onto a catheter assembly for deployment within a body lumen. Stents may be implanted in a variety of body lumens or vessels such as within the vascular system, urinary tracts, bile ducts, etc. Stents may be used to reinforce body vessels and to prevent restenosis following angioplasty in the vascular system. They may be self-expanding, such as a nitinol shape memory stent, mechanically expandable, such as a balloon expandable stent, or hybrid expandable.
[0004] Prior to delivery a stent or stents may be retained on a portion of the delivery catheter by crimping the stent onto the catheter, retaining the stent in a reduced state about the catheter with a removable sheath, sleeve, sock or other member or members, or by any of a variety of retaining mechanisms or methods. Some examples of stent retaining mechanisms are described in U.S. Pat. No. 5,681,345; U.S. Pat. No. 5,788,707; U.S. Pat. No. 6,066,155; U.S. Pat. No. 6,096,045; U.S. Pat. No. 6,221,097; U.S. Pat. No. 6,331,186; U.S. Pat. No. 6,342,066; U.S. Pat. No. 6,350,277; U.S. Pat. No. 6,443,880; U.S. Pat. No. 6,478,814 and U.S. patent application Ser. No. 09/664,268 entitled Rolling Socks and filed Sep. 18, 2000.
[0005] In some systems for the delivery of a self-expanding stent, the stent is deployed by a pull back sheath system. When the stent is constrained within the system, the stent is exerting a force onto the inside diameter (ID) of the outer shaft or pull back sheath. The frictional interface between the stent and sheath may cause the sheath to negatively interact with the stent as the sheath is retracted during deployment. Lubricious coatings may be used to aid in reducing the frictional interface between the stent and sheath. In some cases, particularly those involving longer stents and thus greater frictional forces, the forces may be to great for the lubricant to compensate for. As a result, in some systems the frictional forces involved will prevent the catheter from being capable of properly deploying a stent of a desired length.
[0006] Excess frictional interaction between the stent and sheath is of particular concern in systems deploying a stent that incorporates one or more therapeutic coatings thereon, as the coatings may be adversely affected by the frictional interface between the sheath and stent, particularly during sheath retraction.
[0007] The present invention seeks to address these and/or other problems by providing catheter assemblies with a variety of embodiments and features which improve sheath retraction and stent deployment characteristics.
[0008] All U.S. patents, applications and all other published documents mentioned anywhere in this application are incorporated herein by reference in their entirety.
[0009] Without limiting the scope of the invention a brief summary of some of the claimed embodiments of the invention is set forth below. Additional details of the summarized embodiments of the invention and/or additional embodiments of the invention may be found in the Detailed Description of the Invention below.
[0010] A brief abstract of the technical disclosure in the specification is provided as well only for the purposes of complying with 37 C.F.R. 1.72. The abstract is not intended to be used for interpreting the scope of the claims.
BRIEF SUMMARY OF THE INVENTION
[0011] The present invention is directed to a variety of embodiments. For example, in at least one embodiment the invention is directed to a co-axial stent delivery system having a roll back inner membrane and an outer pull-back sheath. Prior to delivery of the stent the inner membrane is disposed directly about the stent and the pull back sheath is disposed about the membrane. A distal end of the membrane is engaged to a distal portion of the sheath and a proximal end of the membrane is engaged to a portion of the inner catheter shaft proximal of the stent retaining region of the catheter assembly. When the pull back sheath is retracted the membrane will be drawn along with the sheath and will roll back proximally along the length of the stent until the stent is fully exposed and deployed.
[0012] In at least one embodiment a lubricious coating is positioned between the roll back membrane and the sheath.
[0013] In at least one embodiment a lubricious coating is positioned between the stent and the roll back membrane.
[0014] In at least one embodiment a fluid is present in a lumen or chamber defined by the roll back membrane and the sheath. The fluid may be sufficiently pressurized to maintain a gap between the membrane and sheath during retraction.
[0015] In at least one embodiment the invention is directed to a tri-axial system wherein a secondary lumen is formed between an intermediate shaft or mid-shaft and the inner shaft proximal to the stent retaining region. The proximal end of the roll back membrane may be engaged to a distal portion of the mid-shaft, thereby extending the secondary lumen into the stent retaining region of the catheter. The secondary lumen provides a flush path through which a fluid may be transported to the stent retaining region during or prior to delivery of the stent.
[0016] These and other embodiments which characterize the invention are pointed out with particularity in the claims annexed hereto and forming a part hereof However, for a better understanding of the invention, its advantages and objectives obtained by its use, reference should be made to the drawings which form a further part hereof and the accompanying descriptive matter, in which there is illustrated and described embodiments of the invention.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S)
[0017] A detailed description of the invention is hereafter described with specific reference being made to the drawings.
[0018] FIG. 1 is a schematic longitudinal cross-sectional view of distal and proximal portions of an embodiment of the invention.
[0019] FIG. 2 is a longitudinal cross-sectional view of the distal portion of the embodiment depicted in FIG. 1 shown during retraction of the membrane and sheath.
[0020] FIG. 3 is a longitudinal cross-sectional view of the embodiment depicted in FIG. 1 shown with the membrane and sheath fully retracted from the stent.
[0021] FIG. 4 is a longitudinal cross-sectional view of an alternative embodiment of the invention.
[0022] FIG. 5 is a longitudinal cross-sectional view of an alternative embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0023] While this invention may be embodied in many different forms, there are described in detail herein specific preferred embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.
[0024] For the purposes of this disclosure, like reference numerals in the figures shall refer to like features unless otherwise indicated.
[0025] In at least one embodiment, an example of which is shown in FIGS. 1-3 , a delivery system 10 , is depicted which includes a catheter 20 which is configured to deliver a stent 30 , which in at least one embodiment is a self-expanding stent.
[0026] Catheter 20 includes a catheter shaft or inner shaft 22 , a portion of which defines a stent receiving region 24 . Catheter shaft 22 may further define a guidewire lumen 26 through which a guidewire 28 may be passed in order to advance the catheter to a predetermined position in a body lumen or vessel. Alternatively, the shaft 22 may be configured as a fixed-wire catheter.
[0027] The catheter 20 may be any type of catheter desired and in some embodiments may include a catheter shaft 22 having a substantially hexagonal cross-sectional shape, such as is described in the Inventor's concurrently filed Application entitled Medical Device Delivery System having Attorney Docket number 10527-552001, the entire content of which is incorporated herein by reference.
[0028] As shown in FIG. 1 , a stent 30 may be a self-expanding stent which is disposed about the stent receiving region 24 of the catheter shaft 22 . In some embodiments the stent may be at least partially constructed from one or more of the following shape memory materials: nitinol, shape-memory polymer(s), etc., but may include other material or materials as well. In at least one embodiment the stent is at least partially constructed of stainless steel, cobalt, chromium, titanium, nickel, and any combinations or alloys thereof.
[0029] In some embodiments the stent includes one or more areas, bands, coatings, members etc that is (are) detectable by imaging modalities such as X-Ray, MRI or ultrasound. In some embodiments at least a portion of the stent 30 is at least partially radiopaque.
[0030] In some embodiments the stent 30 may include one or more therapeutic and/or lubricious coatings 50 applied thereto.
[0031] A therapeutic agent may be included with the stent. In some embodiments the agent is placed on the stent in the form of a coating 50 . In at least one embodiment the coating 50 includes at least one therapeutic agent and at least one polymer agent.
[0032] A therapeutic agent may be a drug or other pharmaceutical product such as non-genetic agents, genetic agents, cellular material, etc. Some examples of suitable non-genetic therapeutic agents include but are not limited to: anti-thrombogenic agents such as heparin, heparin derivatives, vascular cell growth promoters, growth factor inhibitors, Paclitaxel, etc. Where an agent includes a genetic therapeutic agent, such a genetic agent may include but is not limited to: DNA, RNA and their respective derivatives and/or components; hedgehog proteins, etc. Where a therapeutic includes cellular material, the cellular material may include but is not limited to: cells of human origin and/or non-human origin as well as their respective components and/or derivatives thereof. Where the therapeutic agent includes a polymer agent, the agent may be a polystyrene-polyisobutylene-polystyrene triblock copolymer (SIBS), polyethylene oxide, silicone rubber and/or any other suitable substrate.
[0033] In some embodiments the at least a portion of the stent may include a stent covering. The covering may be constructed of a variety of materials such as Dacron, PTFE, etc. In at least one embodiment the covering comprises at least one therapeutic agent.
[0034] In the various embodiments described herein the stent 30 is preferably configured to be at least partially self-expanding or have self-expanding characteristics. As used herein the term “self-expanding” refers to the tendency of the stent to return to a predetermined diameter when unrestrained from the catheter, such as in the manner depicted in FIGS. 1-3 . In the present embodiment when the stent is disposed about the stent receiving region 24 of the catheter shaft 22 , the stent is restrained in its reduced diameter or pre-delivery configuration by retractable sheath 40 which is disposed about the entire length of the stent 30 prior to delivery.
[0035] The sheath 40 includes a stent retaining region 42 , which refers to that region of the sheath 40 which is disposed about the stent 30 prior to delivery. Engaged to a portion of the stent retaining region 42 is a roll back sleeve or membrane 44 . To deliver the stent 30 , the sheath 40 is retracted proximally, which causes the membrane 44 to roll back off of the stent in the manner illustrated in FIGS. 2-3 .
[0036] In some embodiments the membrane 44 comprises a distal end region 43 and a proximal end region 45 . The proximal end region 45 is engaged to a portion of the inner shaft 22 proximal to the stent receiving region 24 .
[0037] The distal end region 43 of the membrane is engaged to a distal end portion 47 of the sheath 40 at an engagement region 46 . The membrane 44 and sheath 40 may be engaged together by any mechanism and/or configuration desired. For example region 43 and portion 47 may be engaged together by chemical, or adhesive welding or bonding, fusion or heat welding, ultrasonic welding, etc.; they may be mechanically engaged along complementary surfaces; an additional component such as a fastener or other device may be utilized to secure the components together, etc. In some embodiments the membrane 44 and the sheath 40 may be butt-welded or joined, or lap-welded or joined.
[0038] As is shown in FIG. 1 , in at least one embodiment the distal end region 43 of the membrane 44 can be folded back upon itself to engage the distal end region of the sheath 40 . This results in effectively engaging the inside surface (i.e. that surface which at its proximal extent is in contact with the exterior of the stent) 56 of the membrane 44 to the inside surface 57 of the sheath 40 . This folded arrangement provides the membrane 44 with a continuous bend region 59 which not only aids in providing the membrane 44 with the tendency to roll back upon itself rather than buckle or slide during retraction, but also aids in the formation of a potential gap between the membrane 44 and sheath 40 proximal to their engagement region 46 .
[0039] As illustrated in the various figures this “gap” functions as a fluid lumen or chamber 60 into which a fluid, represented by arrows 62 , from a fluid source 76 (such as a syringe, etc) may be transported via a fluid port 73 at the proximal end region 74 of the catheter 20 . The proximal end region 74 of the catheter may have any handle configuration desired and may have any desired mechanism for regulating the flow of fluid 62 into and/or out of the chamber 60 . In at least one embodiment the catheter 20 may include a pressure gauge 75 or other mechanism for monitoring and regulating to volume, flow rate, and/or pressure of the fluid 62 with in the catheter.
[0040] In a proximal region of the catheter the fluid chamber 60 acts as a lumen to transport the fluid distally into the area of the stent retaining region of the sheath 40 . The proximal portion of the chamber or lumen 60 is defined by the sheath 40 and the inner shaft 22 . As indicated, the distal region of the chamber 60 is defined by the sheath 40 and the membrane 44 .
[0041] While the fluid 62 may be in the form of a coating, such as a lubricious hydrogel, saline, etc. which aids in reducing the potential frictional interactions between the sheath 40 and membrane 44 , in some embodiments however a volume of fluid 62 may be injected into the lumen 60 under a predetermined pressure which is maintained during the stent delivery process depicted in FIGS. 2 and 3 . The use of fluid 62 under pressure keeps the gap between the sheath 40 and membrane 44 open throughout the retraction process effectively minimizing any sliding friction therebetween, as well as limiting the frictional forces resulting from the stent's tendency to push outward against the sheath 40 . As illustrated in FIG. 2 , in addition to the above, the pressure exerted by the fluid 62 against the membrane 44 maintains the membrane 44 over the stent and provides the folded over membrane 44 with a turgid-like state sufficient to retain a portion of the stent 30 thereunder in the reduced state until the membrane 44 is retracted.
[0042] In some embodiments the pressure exerted by fluid 62 on the membrane 44 may be monitored and regulated by the pressure gauge 75 , such as is shown in FIG. 1 . A desired pressure of fluid 62 may be maintained within the chamber 60 by the use of any of a variety of devices such as stop-cocks, relief valves, etc.
[0043] When the sheath 40 and the membrane 44 are fully withdrawn from about the stent 30 , the stent is delivered into a desired location within a body lumen or vessel.
[0044] Because the sheath 40 , and particularly the distal portion or stent retaining region 42 of the sheath, is configured to retain the stent 30 in its reduced or pre-delivery diameter, in some embodiments at least the stent retaining region 42 of the sheath 40 is constructed to have sufficient hoop strength to prevent the stent from expanding off of the stent receiving region 24 until the sheath 40 is retracted. At least the stent retaining region 42 of the sheath 40 may be constructed from one or more of the materials including but not limited to: polymer materials such as Pebax, Hytrel, Arnitel, Nylon, etc. In at least on embodiment the stiffness of the sheath 40 can be varied by changing the polymer durometers from the proximal end to the distal end by any manner desired.
[0045] In some embodiments the sheath 40 comprises a multi-layer construction wherein one or more materials are layered, braided or otherwise combined to form the sheath 40 .
[0046] In some embodiments the sheath 40 may be provided with a PTFE liner or such a liner may be absent. Where a liner is provided, an inner PTFE liner may be braided with an additional polymer as desired.
[0047] In at least one embodiment the sheath 40 is of the same or similar construction as a guide catheter.
[0048] In some embodiments the sheath 40 is at least partially constructed of a clear polymer. Such a clear polymer may be used to provide the sheath 40 with a substantially clear distal end region. The clear distal end would allow for viewing the stent or implant device in a constrained state under the sheath.
[0049] In at least one embodiment the inside of the sheath is coated for enhanced lubricity.
[0050] While the stent retaining region 42 of the sheath 40 is typically constructed to have greater hoop strength than the membrane 44 , the sheath may be less flexible than the membrane 44 as well.
[0051] The membrane 44 may be at least partially constructed of one or more of a variety of flexible materials such as including but not limited to: Pebax, PET, Nylon, POC, Polyurethane, etc. In some embodiments the material of the membrane 44 may include those which are nanoceramic for added durability. In some embodiments the membrane 44 is at least partially made from one or more polymers with surface alterations such as plasma treatment for enhanced lubricity. In at least one embodiment the membrane 44 comprises one or more layers of material. In at least one embodiment one or both sides of the membrane 44 are coated and/or provided with surface enhancements. Coating can include silicones or other substances to enhance lubricity.
[0052] In at least one embodiment the membrane 44 is at least partially constructed from those materials from which medical balloons are known to be manufactured from. Such membrane material may be blown or extruded to any dimensions desired. The wall thickness of the membrane may vary and may be about 0.001 inches to no more than about 0.005 inches thick. In at least one embodiment the thickness of the membrane is less than about 0.001 inches.
[0053] In the embodiments depicted in FIG. 1 prior to delivery the membrane 44 is a single layer membrane folded over upon itself at the distal end region 43 whereupon it is engaged to the sheath 40 . When the sheath 40 is retracted, the membrane 44 is pulled back off of the stent 30 as the outside fold 52 of the membrane rolls proximally on top of the inner fold 54 proximally until the entire membrane 44 is rolled off of the stent 30 such as is depicted in FIGS. 2-3 .
[0054] During retraction of the membrane 44 , the outer fold 52 of the membrane 44 will roll proximally on top of the inner fold 54 until the entire membrane 44 is rolled off of the stent 30 as depicted in FIG. 3 . As discussed above in some embodiments a lubricant or other fluid 62 may be provided within the lumen 60 to encourage the rolling action of the folds 52 and 54 and/or separate the folds. The fluid 62 may be any type of “inflation fluid” such as may be utilized in balloon catheters which are known, and/or may be any sort of biocompatible fluid or lubricant such as is described in U.S. Pat. No. 5,693,034, the entire content of which is incorporated herein by reference. In some embodiments fluid 62 is a liquid.
[0055] In some embodiments a hub, flange, protrusion(s), marker or other member 70 and 72 may be positioned proximally and/or adjacent to the stent receiving region 24 . In some embodiments member 72 may also be provided with a diameter sufficiently greater than the diameter of the stent in the reduced state, to thereby prevent the stent from being inadvertently displaced in the proximal direction. Alternatively, the stent 30 may be crimped onto, or disposed about, one or more of the members 70 and/or 72 , and/or the catheter 20 may be provided any of the variety of stent retaining mechanisms that are known. Members 70 and/or 72 may also include any known or later developed type of fixation system for reducing the likelihood of stent displacement prior to and/or during deployment.
[0056] Members 70 and/or 72 may be configured to be detectable by imaging modalities such as X-Ray, MRI or ultrasound. In some embodiments at least a portion of one or both members is at least partially radiopaque.
[0057] Turning now to the embodiment depicted in FIG. 4 , in the embodiment shown, the catheter 20 is provided with a secondary lumen 80 which is formed between an intermediate shaft or mid-shaft 82 and the inner shaft 22 proximal to the stent receiving region 24 . In this embodiment, the proximal end region 45 of the membrane 44 is engaged to a distal portion 84 of the mid-shaft 82 . This modified system 10 provides a secondary lumen 80 which extends into the stent receiving region 24 of the catheter 20 which underlies the membrane 44 . The secondary lumen 80 provides a flush path through which a fluid 64 may be transported to the stent receiving region 24 during or prior to delivery of the stent 30 .
[0058] Fluid 64 may be similar or different than fluid 62 .
[0059] Flushing the stent receiving region 24 prior to delivery of the stent 30 and/or prior to use of the device 10 will not only purge the region 24 of air but will also act to reduce frictional engagement of the stent 30 and the membrane 44 prior to and/or during retraction of the membrane 44 . Flushing can also be used to hydrate the shaft walls and/or the stent.
[0060] In some embodiments, a system 10 of the type shown in FIGS. 1-3 may also be provided with a flush path for flushing the stent receiving region 24 of the catheter 20 prior to use. In at least one embodiment, an example of which is depicted in FIG. 5 , a flush path is defined by the guidewire lumen 26 and one or more holes or ports 86 through the stent receiving region 24 of the catheter shaft 22 . Ports 86 provide fluid communication between the guidewire lumen 26 and the stent receiving region 24 . By blocking or plugging the distal end of the guidewire lumen 26 with a shipping mandrel or other device 88 , fluid 64 injected under pressure into the guidewire lumen 26 at the proximal end region 74 of the catheter 20 will be forced through the ports 86 to flush the stent receiving region 24 . In some embodiments the ports 86 may be configured as a one-way valve to allow fluid to exit the guidewire lumen 26 but not re-enter.
[0061] The above disclosure is intended to be illustrative and not exhaustive. This description will suggest many variations and alternatives to one of ordinary skill in this art. All these alternatives and variations are intended to be included within the scope of the claims where the term “comprising” means “including, but not limited to”. Those familiar with the art may recognize other equivalents to the specific embodiments described herein which equivalents are also intended to be encompassed by the claims.
[0062] Further, the particular features presented in the dependent claims can be combined with each other in other manners within the scope of the invention such that the invention should be recognized as also specifically directed to other embodiments having any other possible combination of the features of the dependent claims. For instance, for purposes of claim publication, any dependent claim which follows should be taken as alternatively written in a multiple dependent form from all prior claims which possess all antecedents referenced in such dependent claim if such multiple dependent format is an accepted format within the jurisdiction (e.g. each claim depending directly from claim 1 should be alternatively taken as depending from all previous claims). In jurisdictions where multiple dependent claim formats are restricted, the following dependent claims should each be also taken as alternatively written in each singly dependent claim format which creates a dependency from a prior antecedent-possessing claim other than the specific claim listed in such dependent claim below.
[0063] This completes the description of the preferred and alternate embodiments of the invention. Those skilled in the art may recognize other equivalents to the specific embodiment described herein which equivalents are intended to be encompassed by the claims attached hereto.
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A medical device comprises a catheter having a catheter shaft, a sheath and a rolling membrane. The sheath is being disposed about the catheter shaft and is longitudinally moveable relative thereto. A distal portion of the sheath defines a stent retaining region. The sheath is moveable between an extended position and a retracted position, wherein in the extended position the retaining region is disposed about a stent receiving region of the catheter shaft, and in the retracted position the sheath is removed from the stent receiving region. End regions of the rolling membrane are respectively engaged to a distal end of the sheath and a portion of the shaft proximal to the stent receiving region respectively.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. provisional patent application Ser. Nos. 60/701,111 filed Jul. 20, 2005, No. 60/714,600 filed Sep. 7, 2005, and 60/723,347 filed Oct. 4, 2005. Further, this application is related to co-filed U.S. patent application Ser. Nos. ______ [SVCSystem], ______ [SVC] and ______ [Jitter]. All of the aforementioned priority and related applications are hereby incorporated by reference in their entireties.
FIELD OF THE INVENTION
[0002] The present invention relates to multimedia and telecommunications technology. In particular, the invention relates to systems and methods for audio and videoconferencing between endpoints over electronic communication networks based on signal compression using scalable video and audio coding techniques.
BACKGROUND OF THE INVENTION
[0003] Scalable coding techniques allow data signals (e.g., audio and/or video data signals) to be coded and compressed for transmission in a multiple-layer format. The information content of a subject data signal is distributed among its coded multiple layers. Each of the multiple layers or combinations of the layers may be transmitted in respective bitstreams. A “base layer” bitstream, by design, may carry sufficient information for a desired minimum or basic quality level reconstruction, upon decoding, of the original audio and/or video signal. Other “enhancement layer” bitstreams may carry additional information, which can be decoded to improve upon the basic level quality reconstruction or resolution of the original audio and/or video signal. The scalably coded multiple-layer structure is such that the decoding a particular enhancement layer bitstream requires the availability of the information in the base layer bitstream and possibly the additional information in other lower enhancement layer bitstreams.
[0004] It should be noted that other methods of creating enhancement layers also include: a) complete representation of the high quality signal, without reference to the base layer information, a method also known as ‘simulcasting’; or b) two or more representations of the same signal in similar quality but with minimal correlation, where a sub-set of the representations on its own would be considered ‘base layer’ and the remaining representations would be considered an enhancement. This latter method is also known as ‘multiple description coding’. For brevity all these methods are referred to herein as base and enhancement layer coding.
[0005] Scalable Audio Coding (SAC) and Scalable Video Coding (SVC) may be used in audio and/or videoconferencing systems implemented over electronic communication networks. Co-filed U.S. patent application Ser. Nos. ______ [SVCSystem] and, ______ [SVC] describe systems and methods for scalable audio and video coding for exemplary audio and/or videoconferencing applications. The referenced patent applications describe particular IP multipoint control units (MCUs) called Scalable Video Conferencing Servers (SVCS) and Scalable Audio Conferencing Servers (SACS) that are designed for coordinating the transmission of SAC and SVC layer bitstreams between conferencing endpoints.
[0006] For the conferencing applications, in which audio and video pictures are exchanged between conferencing endpoints, the loss of enhancement layer information or bitstreams during transmission may be tolerable. However, any loss of base layer information or bitstreams during transmission may be intolerable. Loss of data or information in the base layer bitstreams can lead to significant degradation of the desired basic or minimum quality of audio and/or video signals reconstructed at receiving endpoints. Such degradation of the desired basic or minimum quality reconstructions may result in unsatisfactory performance of the conferencing applications. Thus, the near-lossless delivery of the base layer bitstreams over the communications network is important for any application based on scalable or layered codecs.
[0007] On best-effort networks (e.g. Internet Protocol (IP) networks), delivery of the base layer bitstreams may occur over unreliable channels, in which reliable delivery may be implemented using available transport-layer techniques. Transport-layer techniques available for this purpose include, for example, standard techniques (e.g., forward error correction (FEC) and automatic repeat request (ARQ)), and the techniques described in U.S. Pat. No. 5,481,312, entitled “Method Of And Apparatus For The Transmission Of High And Low Priority Segments Of A Video Bitstream Over Packet Networks,” which may be used to improve recovery mechanisms for lost packet transmissions and to mitigate the effects of packet loss. In some instances, the base layer may be transmitted reliably off-line prior to real-time data transmission as described in U.S. Pat. No. 5,510,844, entitled “Video Bitstream Regeneration Using Previously Agreed To High Priority Segments.”
[0008] On Internet Protocol (IP) networks that allow differentiated services (DiffServ), the base layer can be transmitted over a high reliability connection. However, in practice, allocating a high reliability channel for the base layer data transmission to each endpoint or conference bridge connection in the network can be difficult, for example, when there are a number of different conferencing sessions of short duration. Reserving and provisioning a high reliability channel over a Diffserv-capable IP network or other network, involves additional signaling and/or manual configuration procedures. These additional signaling and/or manual configuration procedures can be burdensome, especially when they have to be repeated for the number of different conferencing sessions of short duration, which may require different sets of high reliability channel connections between conferencing endpoints and/or bridging servers (e.g., MCUs, SVCSs and SAC's).
[0009] Consideration is now being given to alternate or improved ways for establishing high reliability network communication channels to transport sensitive base layer bitstreams between conferencing endpoints.
SUMMARY OF THE INVENTION
[0010] Systems and methods are provided for establishing permanent or semi-permanent high reliability channels (HRC) between endpoints and bridges in an electronic communications network. A HRC bandwidth may be reserved for and used for reliable transport and delivery of high-priority or sensitive data (e.g., base layer data bitstreams in conferencing applications that employ scalable audio and/or video coding of data signals).
[0011] The inventive systems and methods involve establishing a high-reliability connection with reserved bandwidth for transmitting real-time data from a first endpoint or server to a second endpoint or server in an electronic communications network. In an embodiment of the present invention, the high-reliability connection is based on a technology that is different than the one used for conventional transmission of data between the first endpoint/server and the second endpoint/server in the electronic communications network. Accordingly, the high-reliability connection can be advantageously established between the endpoints/servers independently of the individual communication or conferencing sessions hosted on the network.
[0012] In another exemplary embodiment of the present invention, high-priority and sensitive data from two or more servers or endpoints is multiplexed into a single packet for transmission over a connection in a manner designed to ensure reliable transmission and delivery of the data. The connection may be a permanent connection, or a semi-permanent connection that is set up or terminated separately from the conferencing session, or a semi-permanent connection where the bandwidth is adjusted in operation in response to estimates of network traffic between the first server and the second server.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIGS. 1A and 1B are block diagrams illustrating features of an exemplary system for establishing high reliability connections for delivering sensitive data in a protective manner, in accordance with the principles of the present invention.
[0014] Throughout the figures the same reference numerals and characters, unless otherwise stated, are used to denote like features, elements, components or portions of the illustrated embodiments. Moreover, while the present invention will now be described in detail with reference to the figures, it is done so in connection with the illustrative embodiments.
DETAILED DESCRIPTION OF THE INVENTION
[0015] The present invention provides a permanent or semi-permanent high reliability connection (HRC) between network points for transmission and delivery of high-priority or sensitive data. The high-priority or sensitive data may, for example, be scalably coded base layer data used in point-to-point or multipoint conferencing applications, which employ scalable audio and/or video coding. It should be noted that other methods of creating a base layer also include simulcasting and multiple description coding, among others, and. for brevity we refer to herein all these methods as base and enhancement layer coding.
[0016] FIGS. 1A and 1B show implementation of an HRC 140 in an exemplary electronic communications network (e.g., IP network 100 ). Exemplary communications network 100 may, for example, span two remote college campuses A and B each of which is served by a local area network that provide services to local users (e.g., LAN 1 and LAN 2 operating in college campuses A and B for local users 110 a and 110 b , respectively). MCU 120 a and MCU 120 b are disposed in LAN 1 and LAN 2 , respectively. Local users 120 a (e.g., users 1 , 2 , . . . k) and 120 b (e.g., users 1 , 2 , . . . m) at each campus may be connected to their respective MCU units in any suitable network topology (e.g., a star configuration). Further, MCU 120 a and 120 b may have any suitable network bridge device design, including, for example, conventional MCU, scaleable video coding server (SVCS), and scaleable audio coding server (SACS) designs. Exemplary SVCS and SACS are described in co-filed U.S. patent application No. SVCS. FIG. 1B shows an example where MCU 120 a and 120 b are SACS devices.
[0017] For inter-campus communications over communications network 100 , MCU 120 a and MCU 120 b may be connected by a best-effort link or trunk 130 .
[0018] In accordance with the present invention, MCU 120 a and MCU 120 b also are connected to each other by a second communication link or trunk (i.e., HRC 140 ) in parallel to best-effort trunk 130 . HRC 140 may be permanently established between the two MCUs to provide a minimum of reliable services for audioconferencing, videoconferencing and other delay-sensitive applications. HRC 140 may, for example, be designated to carry loss-sensitive base layer bitstreams between the two MCUs for inter-campus scalable video/audio conferencing applications. Less loss-sensitive bitstreams (e.g., enhancement layers bitstreams) may be transported over best-effort trunk 130 using conventional IP network techniques.
[0019] HRC 140 may be implemented or configured using a technology other than the conventional best-effort delivery technology used in IP network 100 to establish best-effort trunk 130 . For example, using conventional best-effort delivery technology, a shared line in IP network 100 may function as best-effort trunk 130 for delivering enhancement layers data. In contrast, HRC 140 may be a private line with bandwidth reserved or designated for transporting base layer data.
[0020] HRC 140 may be a permanent trunk installation. However, in an alternate embodiment of the invention, in suitable IP networks HRC 140 may be configured as almost permanent or semi-permanent installation. For example, IP network 100 may be a network having differentiated services (DiffServ) capabilities. In such a network, the DiffServ capabilities may be advantageously exploited to establish or designate a high reliability connection as HRC 140 for a predetermined fixed period of time. The bandwidth of the high reliability connection used as HRC may be adjusted and reserved for a fixed or variable period of time depending on network conditions.
[0021] In the absence of other methods for establishing HRC 140 or if an established HRC 140 is not sufficiently reliable, automatic repeat request (ARQ) or forward error correction techniques (FEC) may be used. For example, an endpoint (e.g., users 1 , 2 , etc.) or its bridge (e.g., MCU 120 a or MCU 120 b ) may proactively repeat or duplicate transmissions of information delivered over HRC 140 . The number of such automatic repeat transmissions may depend on forecasted channel error or loss conditions and may be suitably selected to prospectively compensate for expected losses in transmission. Alternatively, an endpoint or MCU may retransmit compensating information retrospectively in response to actual loss. For example, the endpoint of MCU may cache information transmitted over HRC 140 , and retransmit specific cached information only upon request by a receiving endpoint or MCU. This procedure may be appropriate in cases where information loss can be detected and reported quickly by a receiving endpoint or MCU.
[0022] The aforementioned methods for establishing a reserved-bandwidth HRC 140 may be applied in an electronic communication network to endpoint-to-MCU, MCU-to-endpoint, or MCU-to-MCU connections, individually or in any suitable combination, depending on available channel characteristics and network conditions. Further, as previously noted, the MCUs may be of conventional design or may be designed for scaleable video and/or audio coded transmissions.
[0023] An important benefit of using a trunk with an HRC is that in a multi-hop connection, any protocol operations (e.g., retransmissions) related to reliability are limited between the two immediately connected points. This minimizes the impact to the end-to-end delay. In contrast, a system that operated on an end-to-end basis would have to sustain delays equal to the entire end-to-end delay.
[0024] Other aspects of the present invention relate to bandwidth management for HRC 140 . In instances where there is excess bandwidth available on HRC 140 , (i.e. when all of the reserved bandwidth of HRC 140 is not used for transporting the base layer bitstreams), one or more less loss-sensitive enhancement layers bitstreams also may be transported on HRC 140 . Multiplexing the base layer bitstreams and allowed enhancement layers bitstreams over the high reliability channel may be accomplished using standard packet multiplexing technologies (e.g., TCP/IP stack technologies).
[0025] In another exemplary embodiment of the present invention, base layer video, audio and other time-sensitive data packets from several users may be combined or mixed into packets with larger payloads reducing the packet header overhead. The mixed-packet payloads have reduced bandwidth requirements and are transported over HRC 140 high-reliability connection.
[0026] Further, when scalable audio and/or video coding functions are used, there may be periodic changes in the data packet sizes in the audio video stream. In such circumstances, MCUs 120 a and 120 b (e.g., SVCS or SACS) may be configured to send control signals to transmitting endpoints to modulate or stagger data transmissions in order to avoid accumulation of larger packets from different endpoints for transmission over HRC 140 at the same time. Such a configuration may even out bandwidth demand surges and improve trunk utilization.
[0027] While there have been described what are believed to be the preferred embodiments of the present invention, those skilled in the art will recognize that other and further changes and modifications may be made thereto without departing from the spirit of the invention, and it is intended to claim all such changes and modifications as fall within the true scope of the invention. For example, the inventive HRC has been described herein as a second communication link or trunk between two MCUs in a multi-endpoint conferencing arrangement. However, it is readily understood that the inventive HRC can be advantageously implemented in other network configurations and between any two network elements (e.g., network endpoints or terminals, inter- and intra-network points, network bridge devices or servers). For example, an HRC or trunk may be established between two users for direct endpoint-endpoint communications by interposing a suitably configured MCU (e.g., MCU 120 a or MCU 120 b ) between the users. As another example, a suitably configured MCU may be merged or integrated with an endpoint itself to provide an HRC/trunk starting at the endpoint itself.
[0028] It also will be understood that in accordance with the present invention, the HRCs be implemented using any suitable combination of hardware and software. The software (i.e., instructions) for implementing and operating the aforementioned HRCs can be provided on computer-readable media, which can include without limitation, firmware, memory, storage devices, microcontrollers, microprocessors, integrated circuits, ASICS, on-line downloadable media, and other available media.
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A method for transport of high-priority, loss-sensitive data and other less loss-sensitive data between parties in a conference or communication session on an electronic communications network includes establishing a high-reliability connection between two points in the network using a connection technology or transport method that is different than that used for otherwise transmitting conference or communication session data between the two points and transmitting the high-priority, loss-sensitive data over the established high-reliability connection.
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FIELD OF THE INVENTION
The present invention relates to a device for articulating a cover or lid to a frame in particular of a manhole.
BACKGROUND
A device of this type is known, which enables the cover to adopt a position for sealing or closing the frame, or an open position in which the cover is upright so as to allow an operator to access the manhole.
This articulation device includes a male component connected to the cover and mounted with limited pivoting in a housing made in the frame.
The cover can be locked to the frame by a latch placed on the opposite side from the articulation.
However, this device presents a major drawback in that when in the upright position for opening the cover, it can be extracted from the frame by malicious persons.
In order to solve this problem, locking means of the lock type have been associated with the articulation in order to connect the cover to the frame permanently.
However, these means have a complex structure and increase the manufacturing costs of the articulation device.
SUMMARY OF THE INVENTION
The present invention aims to eliminate the aforementioned drawbacks by proposing a device for articulating a cover or lid to a frame in particular of a manhole, which enables the cover to adopt a position for sealing the frame, or an open position in which it is upright so as to allow access to the opening of the frame and including a male component connected with the cover and mounted with limited pivoting in a housing made in the frame, characterized by the fact that the male component of the articulation can be, as desired, either mounted in a removable manner in its housing of the frame in order to allow the cover to be pulled off the frame when in its upright position, or connected in its housing of the frame so that the cover cannot be removed from its frame.
Preferably, the male articulation component includes a cylindrical barrel set in the housing of the frame configured in the form of a clevis, making it possible to support a hinge pin which passes through the cylindrical barrel and can be attached in a tamper-proof manner to the clevis in order to make it so that the cover cannot be removed from its frame.
The diameter of the hinge pin is smaller than the diameter of the bore of the cylindrical barrel through which this pin passes, where the ends of the pin are attached, for example by welding, respectively to the two parallel walls of the clevis.
The cylindrical barrel has means for holding the cover in its upright position.
The holding means advantageously includes two stubs connected to the ends of the cylindrical barrel perpendicularly to it and which can engage by gravity, when the cover is in the upright position, respectively in two recesses in the bottom of the housing of the frame.
When the cover and the frame are circular, the cylindrical barrel is attached to the cover by a radial projecting piece in such a way that the barrel and the projecting piece have a T-shaped configuration.
The cover occupies an upright open position of approximately 90° relative to the frame.
BRIEF DESCRIPTION OF DRAWING FIGURES
The invention will be better understood and its other objectives, characteristics, details and advantages will appear more clearly in the following explanatory description in reference to the drawings given only by way of example illustrating an embodiment of the invention and in which:
FIG. 1 is a perspective view of a manhole cover and frame assembly with the cover articulated to the frame according to the invention;
FIG. 2 is an enlarged perspective view of the articulation of the invention which allows attachment of the cover to the frame;
FIG. 3 is an enlarged perspective view similar to that of FIG. 2 and representing only the housing of the frame which makes it possible to receive the articulation of the invention;
FIG. 4 is an enlarged perspective view similar to that of FIG. 3 and showing also a hinge pin which passes through the housing of the frame; and
FIG. 5 is an enlarged perspective view of a part of the cover with the male articulation component.
DETAILED DESCRIPTION
In reference to the figures, reference 1 designates a frame which has a generally circular shape and on which cover or lid 2 , also circular, is articulated, where it is understood that frame 1 and cover 2 may be of different shapes, for example, rectangular or square.
Frame 1 is intended to be sealed in the pavement so as to constitute, with cover 2 , a manhole.
Articulation 3 allows cover 2 to adopt a position for sealing or closing of frame 1 represented in FIG. 1 or an open position, not represented, in which cover 2 is upright in a determined angular position relative to the frame in order to allow an operator to access the manhole through the opening of frame 1 .
As is known in itself, articulation 3 includes male component 4 connected to cover 2 and mounted with limited pivoting or rotation in housing 5 arranged in frame 1 .
FIG. 1 also shows that cover 2 is provided with latch 6 , known in itself, diametrically opposite from articulation 3 and allowing one to lock cover 2 to frame 1 in its closed position.
According to the invention, male articulation component 4 may as chosen be either mounted in a removable manner in its housing 5 of frame 1 to allow cover 2 , if desired, to be pulled off frame 1 in its upright position, or to be connected in its housing 5 so that cover 2 cannot be disassembled from frame 1 .
Thus, articulation 3 of the invention, with the same cast elements, can as chosen be made part of the frame so that cover 2 cannot be disassembled, or attached in a removable manner in its housing 5 of frame 1 to allow cover 2 to he pulled off the frame.
To this end, male articulation component 4 includes cylindrical barrel 7 set in housing 5 of frame 1 , housing which is configured in the form of a clevis for support of hinge pin 8 which goes freely through longitudinal bore 9 of barrel 7 and is attached in a tamper-proof manner to the clevis of housing 5 .
More precisely, the clevis of housing 5 is defined by two essentially parallel walls 10 externally connected to circular peripheral rim 1 a of frame 1 in which cover 2 is set. Each wall 10 is thus situated in the extension of a chord of frame 1 . Hinge pin 8 goes through holes 10 a in each of walls 10 , which are perpendicular to the hinge pin 8 , and ends of the hinge pin 8 are connected to the respective walls 10 . For example, each end of hinge pin 8 is connected by welding to the external side of wall 10 as indicated at 11 in FIGS. 2 and 4 . Male component 4 of articulation 3 also has projecting piece 12 connected radially to cover 2 and which can engage, in the closed position of cover 2 , in opening 13 , which is delimited between two circumferentially spaced walls 14 in extension of rim 1 a of frame 1 and delimiting, with walls 10 and their connecting external wall 15 , housing 5 for male articulation element 4 . Thus, the latter has a T-shaped general configuration.
The diameter of bore 9 of barrel 7 is larger than the diameter of hinge pin 8 .
Cylindrical barrel 7 has two stubs 16 respectively connected to both ends of barrel 7 perpendicularly to its longitudinal direction, protruding on the same side and situated approximately in the same longitudinal median plane as projecting piece 12 and barrel 7 . The two stubs 16 make it possible to maintain cover 2 in its upright open position by respectively engaging in two recesses 17 in the bottom of housing 5 . Preferably, cover 2 is maintained in its upright position at approximately 90° relative to the plane passing through the upper edge of rim 1 a of frame 1 .
Setting of the two stubs 16 by gravity in their respective recesses 17 , when cover 2 has its male component 4 articulated in such a manner that it cannot be disassembled, in its housing 5 by hinge pin 8 , is allowed by the fact that the diameter of bore 9 of cylindrical barrel 7 is larger than the diameter of hinge pin 8 .
Of course, when one wishes to make articulation 3 removable relative to frame 1 in order to allow cover 2 to be extracted from the frame, hinge pin 8 is not present at all, and the two stubs 16 can also engage by gravity in their respective recesses when cover 2 is in its upright position in order to prevent it from tipping over in its frame.
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A device for articulating a stopper or lid to a frame, in particular of a man hole. The male articulating member may optionally be mounted either removably in its housing of the frame to enable the stopper to be extracted from the frame in its upright position or secured in its housing such that the stopper is not detachable from the frame.
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