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This application is a Continuation-in-Part Application of U.S. Patent Application Ser. No. 07/171,436, filed Mar. 21, 1988, now patented U.S. Pat. No. 4,937,295.
BACKGROUND OF THE INVENTION
This invention relates to new boron resins possessing very high selective absorbent power which are stable in organic solvents and in aqueous acid and alkaline solutions.
More particularly, the invention relates to boron resins consisting of an acrylic polymer matrix functionalized with quaternary ammonium groups, an epoxy group and phenylboric groups of general formula (I): ##STR2## in which:
P is a polyacrylic matrix,
R is --(CH 2 ) n -- where n lies between 0 and 5,
R 1 and R 2 , which can be the same or different, are C 1 -C 5 alkyl,
R 3 is --(CH 2 ) n -- where n varies from 1 to 5,
Y is --O--, --S--, ##STR3## where R is a C 1 -C 5 alkyl, and
X - is an anion chosen from halogens and hydroxyl;
The invention also relates to a process for producing the boron resins defined by general formula (I).
In European Patent 8510934.8 we have already described boron resins with a polyacrylic matrix bifunctionalized with quaternary ammonium groups and alkylphenylboric groups, which possess good chemical and mechanical stability characteristics and can be used in industrial processes, they having a marked selective absorbent action particularly in separating lactulose from its mixtures with other carbohydrates, generally lactose and galactose.
It has now been discovered that boron resins with further improved selectivity in separating sugars can be obtained by the process of the present invention, which is described in detail hereinafter.
DETAILED DESCRIPTION OF THE INVENTION
The boron resins of the present invention are prepared from a polyacrylic resin obtained by cross-linking an acrylic ester with divinylbenzene and preferably having the following characteristics:
______________________________________Percentage of cross-linkage 4%Mean pore diameter 1100 ÅSpecific surface area 10 m.sup.2 /gParticle size 0.2-0.4 mm (90%)______________________________________
This resin is firstly subjected to a transamination reaction by reacting with disubstituted diamines.
The aminated acrylic resin is then reacted with an epihalohydrin in an inert solvent such as tetrahydrofuran or dioxane, and the epoxy resin obtained in this manner is reacted at ambient temperature with a boroxin, to produce a resin represented by formula (I).
Alternatively, the chosen boroxin can firstly be reacted with an epihalohydrin to obtain an intermediate of general formula (II): ##STR4## and this can be reacted with the aminated polyacrylic resin, to obtain a boron resin corresponding to general formula (I).
The preferred conditions for implementing the individual process steps of the two alternatives indicated schematically heretofore are as follows:
(a) Transamination reaction: this is conducted by known methods, by reacting the polyacrylic matrix with a disubstituted diamine, to obtain an aminated acrylic resin of general formula: ##STR5## where P, R, R 1 and R 2 have the aforesaid meanings.
(b) Reaction of the aminated acrylic resin with an epihalohydrin: the aminated acrylic resin is pretreated by a process comprising regenerating in C1 form by reaction with a dilute NaCl and HCl solution at about ambient temperature, washing with demineralized water until neutral, regenerating in OH form by treatment in aqueous ammonia at about ambient temperature, washing with demineralized water until neutral, washing with acetone and drying under vacuum.
At this point the resin is placed in a polar aprotic solvent, such as dioxane, and heated under reflux with epichlorohydrin dissolved in the same solvent and a catalytic quantity of potassium iodide, heating under reflux to between 40° and 100° C. for 15-25 hours. After filtration and washing repeatedly with the same solvent, the crude product is ready for the subsequent reactions.
(c) Reaction with the boroxin: the resin obtained in (b) is treated, in suspension in an organic solvent of the type used in (b), with the chosen boroxin at a temperature of between 50° and 100° C. for 36-48 hours.
After cold filtration, the product is washed repeatedly with the same solvent and then with a dilute sodium hydroxide solution.
It is finally washed with water until alkaline reactions disappear.
Alternatively:
(a') Transamination reaction as in (a)
(b') Reacting the chosen boroxin with an epihalohydrin. This reaction takes place in an aliphatic hydrocarbon or chlorinated solvent at a temperature of between 0° and 10° C. for 10-15 hours.
After distilling off the solvent under reduced pressure, the product is taken up in a chlorinated aliphatic solvent, then again distilling to eliminate the excess epichlorohydrin.
A dense oil is obtained from which the required product is crystallized using a chlorinated aliphatic solvent.
(c') Reacting the product obtained in (b') with the aminated acrylic resin.
The aminated acrylic resin, pretreated as described in (b), is placed in a solvent of the type used in (b), for example dioxane, a product such as that obtained in (b') is added, together with a catalytic quantity of potassium iodide, and the mixture heated under reflux to a temperature of between 40° and 80° C. for 15-25 hours.
After cold filtration, the product is washed repeatedly with the same solvent and finally with solvent to which hydrochloric acid has been added, to obtain the required product.
The reaction sequence involved in the first alternative is for example the following: ##STR6##
The reaction sequence involved in the second alternative is for example the following: ##STR7##
Some practical embodiments of the processes and resin of the present invention are given hereinafter in order to make the processes and resin more easily reproducible.
EXAMPLE 1
(a) Preparation of the polyacrylic matrix
A mixture consisting of 50 g of methylacrylate, 2 g of 1,4-divinylbenzene, 1 g of 1,4-ethylvinylbenzene and 1 g of benzoyl peroxide in 250 ml of a 0.2% aqueous solution of polyvinyl alcohol is fed into a 500 ml flask fitted with an agitator, thermometer and condenser.
It is heated for 20 minutes to 50° C. and then overnight to 90° C. under suitable agitation. The product formed is filtered off, washed with deionized water, alcohol and ethyl ether, and dried at 50° C. in an oven under vacuum for 5 hours.
47 g of copolymer are obtained, having the following characteristics:
______________________________________percentage of cross-linkage 4%mean pore diameter 1100specific surface area 10 m.sup.2 /gparticle size 0.2-0.4 mm (90%)______________________________________
(b) Preparation of the aminated resin
The copolymer of step (a) is swollen for 4 hours in 400 ml of dimethylformamide and is then fed into a 50 ml flask fitted with a mechanical stirrer, thermometer and condenser with a calcium chloride tube. 45 g of dimethylethyldiamine and 0.5 g of K 2 CO 3 as catalyst are added.
It is kept overnight at 15° C. under agitation, after which it is allowed to cool, the product filtered off and washed with dimethylformamide, water, 4% NaOH and then again with water until neutral, then with alcohol, and is dried in an oven under vacuum at 60° C. for 4 hours. 45 g of amine resin are obtained having the following characteristics:
______________________________________N(CH.sub.3).sub.2 6 meq/g of dry resinmean pore diameter 1000 Åspecific surface area 12 m.sup.2 /gparticle size 0.2-0.4 mm (80%)______________________________________
(c) Preparation of the epoxy resin
45 g of acrylo-amine resin from step (b) are subjected to the following sequence of operations:
the resin is regenerated in C1 - form by treatment with 130 ml of a NaC1 solution of 100 g/l concentration at a temperature of 20° C. for 60 minutes; the regeneration is completed by treatment with 150 ml of a 10% HC1 solution at a temperature of 20° C. for 40 minutes;
the resin is washed with demineralized water until neutral;
the resin is regenerated in OH - form by treatment with 200 ml of an NH 3 solution of 40 g/l concentration at a temperature of 20° C. for 90 minutes;
the resin is washed with demineralized water until neutral;
it is washed with acetone and dried by heating under vacuum at 55° C. for 8 hours;
200 ml of dioxane are added to the resin and the resin left n the dioxane at ambient temperature for 24 hours.
40 grams of resin pretreated in this manner, corresponding to 160 ml, are fed into a glass flask fitted with a reflux condenser, a CaC1 2 tube, thermometer and mechanical agitator.
120 ml of epichlorohydrin dissolved in 500 ml of dioxane and 20 g of potassium iodide are added, the mixture suitably agitated and kept at 50° C. for 24 hours.
On termination of the reaction, the mixture is filtered through a Buchner funnel and washed by washing three times successively with 500 ml of dioxane each time, followed by filtration.
The product is used crude in the next reaction.
(d) Preparation of epoxyaminoboron resin
The crude epoxy resin from the preceding reaction is placed in 1000 ml of dioxane. 120 g of m-aminobenzeneboronic acid are then added.
The suspension is heated to 80° C. and kept under agitation for 42 hours.
On termination of the reaction the mixture is filtered cold through a Buchner funnel, the residue obtained is taken up in 1000 ml of a dioxane/0.2N NaOH mixture and again filtered. The product is then washed with 1000 ml of a 0.2N NaOH solution, the resin filtered through a Buchner funnel and washed abundantly with water until alkaline reaction in the filtrate disappears.
In this manner 55 g of resin are obtained with a volume of about 210 ml.
The resin has the following characteristics:
______________________________________degree of functionalization 4.1 meq of boron per gram of dry resinpercentage of cross-linkage 4%pore diameter 1000specific surface area 20 m.sup.2 /gapparent density 0.75 g/mlreal density 1.4 g/mlparticle size 0.2-0.4 mm (80%)______________________________________
(e) Preparation of epoxy oxy-boron resin
The crude resin from the preceding reaction is placed in 1000 ml of dioxane. 120 g of m-hydroxyboronic acid are then added.
The suspension is heated to 80° C. and kept under agitation for 42 hours.
On termination of the reaction the mixture is filtered cold through a Buchner funnel, the residue obtained is taken up in 1000 ml of a dixoane/0.2N NaOH mixture and again filtered.
The product is then washed with 1000 ml of a 0.2N NaOH solution, the resin filtered through a Buchner funnel and washed abundantly with water until alkaline reaction of the filtrate disappears.
55 g of resin are thus obtained with a volume of about 210 ml.
The resin has the following characteristics:
______________________________________degree of functionalization 4.4 meq of boron per gram of dry resinpercentage of cross-linkage 4%pore diameter 1000specific surface area 20 m.sup.2 /gapparent density 0.81 g/mlreal density 1.35 g/mlparticle size 0.2-0.4 mm (80%)______________________________________
EXAMPLE 2
(b) Preparation of the intermediate ##STR8##
50 g of m-aminobenzeneboronic acid are placed in a 250 ml flask and 150 ml of epichlorohydrin are added.
The mixture is cooled to 0°-10° C. and kept at this temperature for 12 hours.
On termination, the solvent is distilled off under vacuum and the residue taken up in dichloropropane, again distilling to remove excess epichlorohydrin.
The dense oil obtained is crystallized from methylene chloride. 32 g of the product concerned are obtained, with an M.P of 78°-80° C.
______________________________________Elementary analysis for C.sub.9 H.sub.13 C1BNO.sub.3 M.W.______________________________________229.26:Calculated: C 47.1 N 6.1 H 5.67Found: C 47.6 N 5.7 H 5.6______________________________________
(b) Preparation of the intermediate ##STR9##
50 g of m-hydroxybenzeneboronic acid are placed in a flask and 150 ml of epichlorohydrin are added.
The mixture is heated to 30°-40° C. and kept at this temperature for 8 hours.
On termination, the solvent is distilled off under vacuum. The oily residue is taken up in 300 ml of ethanol at 50°-60° C., treated with active carbon and filtered.
The clear solution obtained is concentrated to one half its volume, and left standing at 2°-3° C. overnight.
In this manner 42 g of product precipitate and are crystallized from methylene chloride (180 ml) to obtain 38 g of the required product. M.P. 102°-105° C.
______________________________________Elementary analysis for C.sub.9 H.sub.12 C1BO.sub.4 M.W.______________________________________230.26:Calculated: C 46.4 N 5.2 C1 15.39Found: C 46.7 N 5.1 C1 15.6______________________________________
(c) Preparation of epoxy-oxy-boron resin ##STR10##
45 g of acrylo-amine resin are subjected to the following sequence of operations:
the resin is regenerated in C1 - form by treatment with 130 ml of an NaC1 solution of 100 g/l concentration at a temperature of 20° C. for 60 minutes; the regeneration is completed by treatment with 150 ml of a 10% HC1 solution at a temperature of 20° C. for 40 minutes;
the resin is washed with demineralized water until neutral;
the resin is regenerated in OH form by treatment with 200 ml of an NH 3 solution of 40 g/l concentration at a temperature of 20° C. for 90 minutes;
the resin is washed with demineralized water until neutral;
it is washed with acetone and dried by heating under vacuum to 55° C. for 8 hours;
200 ml of dioxane are added to the resin and the resin left in dioxane at ambient temperature for 24 hours.
40 grams of resin pretreated in this manner, corresponding to 160 ml, are fed into a glass flask fitted with a reflux condenser, a CaC1 2 tube, thermometer and mechanical agitator.
1200 ml of dioxane, 65 g of the product of point (b) and 21.8 g of KI are then added. The mixture is suitably agitated, heated to 50° C. and kept under these conditions for 24 hours.
On termination of the reaction, the mixture is filtered through a Buchner funnel and washed by three successive washing and refiltering operations, the first washing being in 500 ml of dioxane, the second in 400 ml of dioxane/0.1N HC1 mixture in a 2/1 volume ratio, and the third in 300 ml of 0.1N HC1.
53 g of resin are obtained with a volume of 200 ml; the resin is of cream color with a certain quantity of light brown beads, and has the following characteristics:
______________________________________degree of functionalization 4.8 meq of B per gram of dry resinpercentage of cross-linkage 4%pore diameter 1000 Åspecific surface area 20 m.sup.2 /gapparent density 0.81 g/mlreal density 1.35 g/mlparticle size 0.2-0.4 mm (80%)______________________________________
EXAMPLE 3
A boron resin of the characteristics of example 1d is rehydrated in deionized water for 8 hours.
100 cc of this resin are placed in a 26 mm diameter column and fed for 60 minutes with 45 cc of a lactulose syrup solution (lactulose 50% by weight, lactose 4% by weight, galactose 4.5% by weight, other sugars 7% by weight) diluted 1 to 2 with deionized water and alkalinized to give a final solution of pH 8. By elution with a mobile phase of the same pH, 180 cc of a solution are obtained containing 21.6 g of unretained sugars, comprising:
______________________________________ lactulose 17.8 g lactose 2.1 g galactose 1.7 g______________________________________
The column is then eluted with a 1N HC1 solution to obtain 150 cc of lactose-free solution containing:
lactulose 11.7 g
galactose 0.25 g
EXAMPLE 4
A boron resin of the characteristics of example 1e is rehydrated with deionized water for 8 hours.
100 cc of this resin are placed in a 26 mm diameter column and fed for 60 minutes with 45 cc of a lactulose syrup solution (lactulose 50%, lactose 1% by weight, galactose 4.5% by weight, other sugars 7% by weight) diluted 1 to 2 with deionized water and alkalinized to give a final solution of pH 8. By elution with a mobile phase of the same pH, 180 cc of a solution are obtained containing 20.8 g of unretained sugars, comprising:
______________________________________ lactulose 16.8 g lactose 2.1 g galactose 1.9 g______________________________________
The column is then eluted with a 1N HC1 solution to obtain 150 cc of a lactose-free solution containing:
lactulose 12.5 g
galactose 0.3 g
Due to their high selective absorbent power, the boron resins of the present invention are particularly suitable for separating carbohydrate mixtures, particularly for purifying lactulose containing solutions.
It is therefore another object of the present invention to provide a method for purifying an aqueous lactulose syrup containing other carbohydrates, which comprises the steps of:
(a) activating a boron resin of general formula (I) ##STR11## in which:
P is a polyacrylic matrix,
R is --(CH 2 ) n -- where n lies between 0 and 5,
R 1 and R 2 , which can be the same or different, are C 1 -C 5 alkyl,
R 3 is --(CH 2 ) n where n varies from 1 to 5,
Y is --O--, --S--, ##STR12## where R is a C 1 -C 5 alkyl, and
X is an anion chosen from halogens and hydroxyl; by salifying the resin with HC1 1N, then by treating with deionized water up to a pH value of the eluate higher than 5, then with NaOH 0.2N and finally with deionized water up to a pH value of the eluate lower than 9;
(b) contacting an aqueous lactulose syrup containing from 20% to 40% by wt. of lactulose and from 5% to 30% by wt. of other carbohydrates with said activated boron resin;
(c) eluting the carbohydrates absorbed on the boron resin with water and then with HC1 from 0.5N to 1N, separately collecting the eluates.
In the preferred embodiments of the invention, the boron resin is loaded in a column, activated as described above and then the impure lactulose solution is percolated therethrough. The rate of percolation is controlled between 0.5 and 3 volumes of syrup/volume of resin per hour.
The temperature of the percolation is not a critical factor and can be comprised between 10° and 60° C. without any significant effect on the absorption capacity of the resin.
The lactulose is strongly and preferably absorbed by the boron resins of the invention in an amount of from 50 to 250 g/lt of resin, independently from the presence of other carbohydrates in the impure solution.
It is thus possible to separate the other carbohydrates from lactulose by eluting the column with 2 to 4 volumes of water per resin volume, so obtaining a solution containing the larger amount of the impurities contained in the original impure syrup.
The resin is then eluted from 1.3 to 2.5 volumes of an aqueous solution of from 0.5 to 1N HC1 per volume of resin by recovering a solution of lactulose with a very low content of other carbohydrates.
In the preferred embodiments of the invention, the solution of lactulose recovered by means of the HC1 treatment are divided in two fractions: the first one up to a pH value of the eluate higher or equal to 3 and the second one with a pH value of the eluate lower than 3. The second fraction of the eluate contains lactulose without any trace of lactose.
EXAMPLE 5-8
100 ml of a boron resin of the characteristics of example 1d are placed in a 26 mm diameter column, salified with HC1 1N, washed with deionized water up to a pH value of the eluate equal to 5, treated with 1,000 ml of 0.2N NaOH and then washed again with water up to a pH value of the eluate equal to 9.
The column is fed for 60 minutes with 100 ml of a lactulose syrup solution containing 30 g of lactulose, 2.3 g of galactose and 2.3 g of lactose.
The column is eluted with 180 ml of deionized water and the eluate collected (eluate A), then with 90 ml of 1N HC1 up to a pH value of the effluent from the column equal to 3 and the eluate collected (eluate B) and finally with 110 ml of 1N HC1 and the eluate (having a pH lower than 3) is collected (eluate C).
The same procedure as above was repeated by changing the concentrations and the type of carbohydrates different from lactulose.
The characteristics of starting products and of the obtained eluates are reported in the following Table 1, together with the volumes of crude syrups and of eluates A, B and C.
TABLE 1______________________________________Ex Product lactulose galactose tagatose lactoseN. volume (ml) (g) (g) (g) (g)______________________________________5 Crude syrup 30 2.3 -- 2.3100 mleluate A 17.8 1.9 -- 2.2180 mleluate B 8.2 0.1 -- --90 mleluate C 3.5 0.15 -- --110 ml6 Crude syrup 60 4.6 -- 4.6200 mleluate A 48.1 4.4 -- 4.6310 mleluate B 8.7 -- -- --90 mleluate C 3.2 0.2 -- --110 ml7 Crude syrup 15 1.2 -- 1.250 mleluate A 6.3 0.5 -- 0.7120 mleluate B 6.9 -- -- 0.490 mleluate C 1.8 0.7 -- --110 ml8 Crude syrup 30 2.1 1.0 2.1100 mleluate A 18.5 1.6 -- 2.0160 mleluate B 8.0 -- 0.6 --90 mleluate C 3.2 0.5 0.4 --100 ml______________________________________
EXAMPLE 9-12
100 ml of a boron resin of the characteristics of example 1e are placed in a 26 mm diameter column, salified with HC1 1N, washed with deionized water up to a pH value of the eluate equal to 5, treated with 1000 ml of 0.2N NaOH and then washed again with water up to a pH value of the eluate equal to 9. The column is fed for 60 minutes with 50 ml of a lactulose syrup solution containing 15 g of lactulose, 1.2 g of galactose and 1.2 g of lactose.
The column is eluted with 95 ml of deionized water and the eluate collected (eluate A), then with 95 ml of 1N HC1 up to a pH value of the effluent from the column equal to 3 and the eluate collected (eluate B) and finally with 85 ml of 1N HC1 and the eluate (having a pH lower than 3) is collected (eluate C). The same procedure as above was repeated by changing the concentrations and the type of carbohydrates different from lactulose.
The characteristics of starting products and of the obtained eluates are reported in the following Table 2, together with the volumes of crude syrups and of eluates A, B and C.
TABLE 2______________________________________Ex Product lactulose galactose tagatose lactoseN. volume ml (g) (g) (g) (g)______________________________________9 Crude syrup 15 1.2 -- 1.250 mleluate A 0.7 -- -- 1.195 mleluate B 8.3 -- -- --95 mleluate C 5.7 1.1 -- --85 ml10 Crude syrup 30 2.4 -- 2.4100 mleluate A 10.5 -- -- 2.2160 mleluate B 10.2 0.4 -- --90 mleluate C 9.0 1.9 -- --105 ml11 Crude syrup 60 4.6 -- 4.8200 mleluate A 42.5 -- -- 4.7340 mleluate B 14.1 0.8 -- --90 mleluate C 3.2 3.8 -- --175 ml12 Crude syrup 15 1.2 0.7 1.250 mleluate A 0.6 -- -- 1.090 mleluate B 8.1 -- -- --85 mleluate C 6.1 1.0 0.6 --100 ml______________________________________
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Stable boron resins of high selective absorbent power, their production process, and processes of using said boron resins. The boron resins include a polyacrylic matrix functionalized with quaternary ammonium groups, an epoxy group and phenylboric groups in accordance with general formula (I): ##STR1## in which P, R, R 1 , R 2 , R 3 , Y and X - are as defined in the text. The resin is prepared by condensing an acrylic resin with an epihalohydrin and then with a halide or hydroxide of an oxiphenyl-aminophenyl- or thiophenyl-boroxin or their alkyl derivatives. Compared with similar currently known resins, the resins of formula (I) have improved selectivity in sugar preparation. They can be used for purifying lactulose.
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FIELD OF THE INVENTION
The present invention relates to an improved fascia cap assembly for roofing. More particularly, the invention is a fascia cap assembly designed to limit water from moving through capillary action back towards the roof. The assembly has an elongated drip edge that displaces water away from the roof, preserving the integrity of the roof and building walls below. The assembly also contains a blocking strip to help the flow of water away from the roof and also to hold the assembly together.
BACKGROUND OF THE INVENTION
Buildings, such as houses and office buildings are made of walls and are covered by a roof. The roof is typically, but not always, downward sloping so that water can drip off the roof and away from the building.
At the point where the water drips off the edge of the roof, a fascia cap is typically installed to provide protection for the roof. The edge of the roof is the place most likely to have water accumulate and a fascia cap is designed to protect water from entering the building walls through the roof.
A disadvantage to prior art designs for fascia caps is that water is often able to seep between the fascia cap and the roof, causing rot and deterioration of the roof and building walls. Prior art fascia caps, such as the one described in U.S. Pat. No. 6,035,587 suffer from a phenomena known as capillary action, which allows water to adhere to the fascia cap and seep through and enter the roof.
Capillary action involves water moving back up the fascia cap due to surface tension. The surface tension results in water penetrating the fascia cap and entering the roof.
Along with water, dirt and other debris may enter the roof via capillary action and surface tension, whereby the water causes the dirt and debris to flow back towards the roof. As such, it important to design a fascia cap that adequately displaces water away from the roof and building and limits capillary action and surface tension from allowing water and debris to seep back into the roof. This limits and potentially prevents rot and decay of the roof and preserves the structural integrity of the roof and building as a whole.
What is desired therefore is to provide a fascia cap design and assembly that mitigates and almost entirely eliminates capillary action. It is further desirable to develop a roofing assembly with a fascia cap having a continuous elongated drip edge that works to mitigate capillary action. It is further desirable and advantageous for the fascia cap to be in one continuous piece for assembly and cost purposes. It is further desirable to have fascia cap assembly with blocking strip that reinforces and attaches the fascia cap to the roof. A method for assembling a roofing assembly having a fascia cap with an elongated drip edge is also desirable.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a fascia cap design and assembly that mitigates and almost entirely eliminates capillary action. It is further object of the present invention to provide a roofing assembly with a fascia cap having a continuous elongated drip edge that works to mitigate capillary action. A further object of the invention is to have the fascia cap be in one continuous piece. A further object of the invention is to have a blocking strip as part of the assembly that reinforces the fascia cap and attaches it to the roof. It is a further object of the present invention to provide a method for a roofing assembly having a fascia cap with a continuous elongated drip edge.
These and other objectives are achieved by providing a roofing assembly for the end of a roof comprising: a fascia cap having a top edge, side edge, and bottom edge, the side edge connecting the bottom edge to the top edge to form a U-shaped body, the bottom edge having a drip edge extending past the U-shaped body; a roofing material; and a shingle material, wherein the body of the fascia cap accepts the roofing material, and wherein the shingle material is adapted to lie flat against the top edge of the fascia cap. This assembly may be used on the following roof systems: TPO-RS, SBS Modified bitumen, all one-ply and BUR, and also used as fascia.
The assembly further may have the drip edge run across the length of the bottom edge and be continuous with the bottom edge. The assembly further may have the edges of the fascia cap be fused together as one piece.
In preferred embodiments, the drip edge is at least as long as the side edge. In other preferred embodiments, the drip edge is at least half as long as the side edge. In other preferred embodiments, the bottom edge is at least as long as the top edge. The assembly functions to limit water from moving through capillary action back towards the roof. The assembly mitigates surface tension allowing water to move back and up towards the roof.
The assembly may further comprise a blocking strip, the blocking strip adapted to lie on top of the shingle material. Fasteners may also be applied that secure the blocking strip to the shingle material, although fasteners are not always necessary. On the bottom surface of the blocking strip, an adhesive may be applied to secure the blocking strip to the shingle material. The adhesive on the bottom surface may heat up and solidify to adhere the blocking strip to the roof, preferably to the shingle material. The blocking strip may also contain side surfaces angled so as to limit and block water from entering the bottom surface of the blocking strip, so water will not interfere and interact with the adhesive material.
Another embodiment of the present invention involves a fascia cap comprising: a top edge, side edge, and bottom edge, the side edge connecting the bottom edge to the top edge to form a U-shaped body, and the bottom edge having a drip edge extending past the U-shaped body. The fascia cap is typically found on the end of the roof.
Furthermore, the fascia cap may have the drip edge run the length of the bottom edge and be continuous with the bottom edge. The drip edge may limit water from moving through capillary action and surface tension back towards the roof.
In another embodiment, the drip edge is at least as long as the side edge. In another embodiment, the drip edge is at least half as long as the side edge. In another embodiment, the bottom edge is at least as long as the top edge. In another embodiment, the elongated drip edge has an axial length of more than half an inch.
The body of the fascia cap may be adapted to accept a roofing material, such as insulation, shingles, wood, or other roofing materials known in the art. The edges of the fascia cap are typically fused together as one piece, through they may also be formed of separate pieces hinged or fused together.
Another embodiment of the present invention involves a method for assembly of a roofing system for the end of a roof comprising the steps of: installing a fascia cap with a top edge, side edge, and bottom edge, the side edge connecting the bottom edge to the top edge to form a U-shaped body, and the bottom edge having a drip edge extending past the U-shaped body; sliding roofing into the body of the fascia cap; and laying shingle material over the top edge of the fascia cap.
The fascia cap of the above method may have the drip edge run across the length of the bottom edge and be continuous with the bottom edge. The method may further comprise applying a blocking strip over the shingle material and adhering the blocking strip to the shingle material. The blocking strip may contain a bottom surface with an adhesive to attach the blocking strip to the shingle material.
Other objects of the invention and its particular features and advantages will become more apparent from consideration of the following drawings and accompanying detailed description. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is perspective view of the assembly for a roof having a fascia cap, roofing material, and shingle material connected in an assembly;
FIG. 2 is side view of the assembly of FIG. 1 ;
FIG. 3 is a perspective view of a fascia cap of an embodiment of the present invention;
FIG. 4 is a side view of the fascia cap of FIG. 3 ;
FIG. 5 is a front view of the fascia cap of FIG. 3 ;
FIG. 6 is a perspective view of a fascia cap of another embodiment of the present invention;
FIG. 7 is a side view of the fascia cap of FIG. 6 ;
FIG. 8 is a front view of the fascia cap of FIG. 6 ;
FIG. 9 is a top view of a blocking strip of an embodiment of the present invention;
FIG. 10 is a bottom view of the blocking strip of FIG. 9 ;
FIG. 11 is a side view of the blocking strip of FIG. 9 .
DETAILED DESCRIPTION OF THE INVENTION
Referring to FIG. 1 , an assembly 100 fitting on the end of a roof in accordance with the present invention is shown. This assembly 100 contains a fascia cap 110 having an elongated drip edge 115 , top edge 120 , side edge 125 , and bottom edge 130 . In a preferred embodiment, the fascia cap 110 is made of a single material such as a metal, metal alloy, hard plastic, or other such material used in the roofing industry. The body 105 of the fascia cap 110 is preferably a U-shape where top edge 120 and bottom edge 130 are connected by side edge 125 . Bottom edge 130 has drip edge 115 extending past U-shaped body 105 .
The fascia cap 110 is designed to accept a roofing material 140 , such as insulation, wood, foam, or any such material that is used in the roofing and construction industry. Shingle material 150 is adapted to lay flat against the top edge of the fascia cap. Single material 150 may be standard housing shingles or other such materials designed to protect a roof from water and wear and tear of external elements.
The assembly 100 may be used on the following roof systems: TPO-RS; SBS Modified bitumen, all one-ply and BUR, and also used as fascia.
In certain embodiments, elongated drip edge 115 runs across the entire length of bottom edge 130 and is continuous with bottom edge 130 . Drip edge 115 may be at least as long as side edge 125 . In other embodiments, drip edge 115 may be at least half as long as side edge 125 . Bottom edge 130 may be as long as top edge 120 , and may be longer in certain embodiments of the invention.
In other embodiments, drip edge 115 , top edge 120 , side edge 125 , and bottom edge 130 are fused together as one piece. This is advantageous in terms of cost of manufacturing the fascia cap as well as to limit points of entry for water.
Furthermore, fascia cap 110 is used to limit water from moving through capillary action or surface tension back towards the roof. Surface tension causes water to adhere to fascia cap 110 and causes the water to move back upward to the roof. Drip edge 115 keeps the water away from fascia cap 110 and allows the water to drip off the fascia cap 110 and away from the roof.
FIG. 1 further shows blocking strip 160 having fasteners 170 and 175 . Fasteners 170 / 175 and blocking strip 160 function to hold roof assembly 100 together and to secure shingle material 150 to fascia cap 110 and roofing material 140 .
The bottom surface of blocking strip 160 also contains adhesive 168 designed to secure blocking strip 160 to shingle material 150 . This adhesive 168 may heat up and solidify to adhere and attach blocking strip 160 to shingle material 150 . Blocking strip 160 also preferably has side surfaces 162 and 165 designed to limit water from entering the bottom surface of blocking strip 160 , which limits water from interfering and interacting with adhesive material 168 .
In FIG. 2 , a side view of assembly 100 is presented. Fascia cap 110 is shown with drip edge 115 , top edge 120 , side edge 125 , and bottom edge 130 . Roofing material 140 is merged into U-shaped body 105 of fascia cap 110 . Shingle material 150 is shown laying flat on the top edge 120 of fascia cap 110 with blocking strip 160 fastened to fascia cap via fastener 170 / 175 . Fastener 170 / 175 are shown holding assembly 100 together. Lower roofing material 210 is also shown, whereby lower roofing material 210 is typically wood or other such material used to provide structural support for the building 250 (not shown).
Also drip edge 115 is shown in its elongated state. Water droplets 220 , 240 are shown on drip edge 115 . Water droplets 220 , 240 are shown moving in a direction away from the roof namely in direction 230 shown by an arrow. This displays how drip edge 115 functions whereby it limits capillary action and causes water and water droplets 220 , 240 to drip away from the roof.
Stopping capillary action is important as it preserves the structural integrity of the roof as well as limits water from seeping into the space between a fascia cap and the roofing material.
FIG. 3 shows the fascia cap, specifically fascia cap 110 having top edge 120 , side edge 125 , bottom edge 130 , and drip edge 115 extending past bottom edge 130 . Fascia cap 110 can be linked together with another fascia cap 300 via locking mechanism 310 . This allows multiple fascia caps to be linked together to cover the length of a roof, so that the entire edge of the roof can be covered if it is longer than individual fascia caps. Furthermore, other embodiments of the present invention allow for different locking mechanisms 310 than the ones shown in FIG. 3 .
FIGS. 4 and 5 show a side view and front view of fascia cap 110 , respectively. Top edge 120 , side edge 125 , bottom edge 130 , and drip edge 115 are displayed and fused together as one piece.
In FIG. 4 , one can see drip edge 115 measured along length x and side edge 125 measured along length y. Length y is the diameter between the inner surface of top edge 120 and bottom edge 130 , which is the length of side edge 125 . Length x is the distance from the end of drip edge 115 to the part where side edge 125 meets drip edge 115 . As shown drip edge 115 is as least half as long as side edge 125 . In other embodiments, drip edge 115 may be at least as long as side edge 125 . The longer the drip edge, the farther away the water is from the roof and the more difficult it would be for water to seep back towards the fascia cap and roof.
FIG. 6 shows a perspective view of a fascia cap 600 of another embodiment of the present invention. Fascia cap 600 has top edge 610 , side edge 615 , drip edge 620 , and bottom edge 625 . Drip edge 620 extends past side edge 615 .
Fascia cap 600 is designed lay on top of and accept fascia cap 110 . This allows fascia cap 600 to cover seem/opening 650 which occurs as a result of fascia caps 110 and 660 being placed side-by-side. When two fascia caps are placed side-by-side, seem 650 results, which can allow water to drip inside the seam and potentially enter the fascia cap and roof. The design of fascia cap 600 allows fascia cap 110 and/or 660 to accept fascia cap 600 and cover seem 650 , preventing water from entering the roof.
As shown in FIGS. 7 and 8 , fascia cap 600 has top wall 610 , side wall 615 , drip edge 620 , and bottom wall 625 . Drip edge 620 has a side wall 622 whereby drip edge 620 can fit around drip edge 115 of fascia cap 110 . This allows fascia cap 110 to fit inside fascia cap 600 .
FIG. 7 also shows the length of drip edge 620 represented by x′. y′ is the diameter between the inner surface of top edge 610 and bottom edge 625 . In the embodiment shown y″ is the length of side edge 615 . As shown drip edge 620 is as least half as long as side edge 615 . In other embodiments, drip edge 620 may be at least as long as side edge 615 . The longer the drip edge, the farther away the water is from the roof and the more difficult it would be for water to seep back towards the fascia cap and roof
FIGS. 9-11 show blocking strip 900 , which is equivalent to blocking strip 160 shown in FIG. 1 . Blocking strip 900 has side walls 910 and 930 , top wall 920 , which has holes 950 , 952 , 955 , and 958 for accepting fasteners (not shown). Adhesive material 940 is shown on the bottom of blocking strip 900 .
Adhesive material 940 is made of housing material 1100 with sticky material 1110 attached to housing material 1100 . Sticky material 1110 connects blocking strip 900 to shingle material 150 (not shown). Sticky material 1110 can heat up and solidify to adhere and attach blocking strip 900 to shingle material 150 .
Blocking strip 900 also contains side walls 910 , 930 , which contain bottom side walls 1020 and 1010 respectively. These walls limit water from entering the bottom of blocking strip 900 , and prevent water from interfering with adhesive material 940 .
Another embodiment of the present invention involves a method for assembly 100 of a roofing system for the end of a roof comprising the steps of: installing a fascia cap 110 with a top edge 120 , side edge 125 , and bottom edge 130 , wherein side edge 125 connects bottom edge 130 to top edge 120 to form U-shaped body 105 , bottom edge 130 having drip edge 115 extending past U-shaped body 105 ; sliding roofing 140 into body 105 of fascia cap 110 ; and laying shingle material 150 over top edge 120 of fascia cap 110 .
The method further may have drip edge 115 run across the length of bottom edge 130 and be continuous with bottom edge 130 . A blocking strip 160 may further be applied over shingle material 150 , adhering blocking strip 160 to shingle material 150 . Blocking strip 160 contains a bottom surface with an adhesive to attach blocking strip 160 to shingle material 150 .
While the invention has been specifically described in connection with certain specific embodiments thereof, it is to be understood that this is by way of illustration and not of limitation and that various changes and modifications in form and details can be made thereto, and the scope of the appended claims should be construed as broadly as the prior art will permit.
The description of the invention is merely exemplary in nature, and thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
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An improved roofing method and assembly having a fascia cap designed to prevent water from moving through capillary action back towards the roof. The assembly has an a elongated drip edge running back the bottom edge of the fascia cap that displaces water away from the roof, preserving the integrity of the roof and building walls below. A blocking strip attaches the fascia cap to the roof, maintaining the assembly and helping the flow of water away from the roof.
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BACKGROUND OF THE INVENTION
Flexible materials of a plastic composition, particularly when foamed, have found use in the field of textiles on the decorative side of fabrics and as coatings on individual textile units such as yarns, strands, and threads. Some materials can be processed as a coating on a strand to produce a coated strand having unique characteristics depending upon the method employed in processing the strand.
For example, U.S. Pat. No. 3,761,346, issued Sept. 25, 1973 to Caroselli et al. discloses a system wherein a plastisol is applied to a linear textile material such as a strand of glass filaments by passing the textile material through an excess of plastisol via two coating/wiping dyes and then advancing the coated textile material into an oven for partial fusion. Subsequently, a second plastisol is applied via a second set of two coating/wiping dyes, followed by a second thermal treatment sufficient to first fuse the coatings and then to activate the blowing agent therein to create a foam-like structure. The second plastisol may or may not contain a blowing agent. Without the blowing agent in the second coating the outer surface of the strand will not have the pits or voids therein which would have been formed if a blowing agent were present.
However, in either instance a nozzle sprays water onto the strand as it leaves the second oven to cool the strand. It has been found that by directing a stream of water against the surface of such a strand while the coating is still in a deformable or tacky state the resulting coated strand will have a wrinkled and dented outer surface even when the second coating does not contain a blowing agent. It is believed that the immediate rapid cooling of the strand by the spray of water contacting the coated strand immediately after leaving the oven causes the coating material to shrink forming the wrinkled outer surface. Since the coating material is still in a delicate tacky or deformable state, the impact of large drops of water upon the strand tends to form indentations therein.
Therefore, it is believed that cooling the coating of the strand according to the principles of this invention permits the coating to expand to and remain at substantially the maximum extent thereof.
SUMMARY OF THE INVENTION
This invention pertains to a method of processing a coated strand by heating the strand, then directing a gas at the strand to cool the strand, and then moving the strand through a zone having an atomized mist of liquid therein to further cool the strand.
It is an object of this invention to provide a method and apparatus for cooling a linear material having a coating thereon in the absence of an undue amount of surface deformation occurring in the coating.
It is another object of this invention to provide a method for producing a composite strand having a smooth, non-lustrous, unwrinkled outer surface over a foam core.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic representation of the system employed in producing the composite strand according to the principles of this invention.
FIG. 2 is a graph depicting the surface temperature of the coated strand as it passes through the first and second cooling zones.
FIG. 3 is an enlarged view of the final product processed according to the principles of this invention.
FIG. 4 is an enlarged view of a similar product except that a stream of water has been directed against the strand to cool the strand (prior art).
DESCRIPTION OF THE PREFERRED EMBODIMENTS
As shown in FIG. 1, a first coating material 11, which can be a plastisol, is applied to a bundle of filaments advancing through a first coating station 12. The bundle of filaments, or strand 10, can be a group of glass filaments having a suitable sizing material thereon. The first coating material 11 can contain a blowing agent. The strand 10 then passes through oven 14 which can be a conventional thermal oven. In practice, the strand with the coating thereon is heated to partially fuse the first coating material in the absence of activating the blowing agent contained therein.
Then the strand 10 passes through a second coating station 16 to receive a layer of a second coating material 17. The second coating material 17 can be a plastisol, and in practice, the second coating material 17 does not contain a blowing agent.
From the second coating station 16 the strand 10 then advances to a second oven 18. Oven 18 can be a conventional thermal oven. In the second oven 18 the first and second coating materials are heated to fuse the two layers together and to activate the blowing agent contained therein. The processes, coating materials, sizings and apparatus of the system thus far described can be of any suitable type. For example, the processes, coating materials, sizings, and apparatus can be of the type described in U.S. Pat. No. 3,761,346, issued to Caroselli et al. on Sept. 25, 1973 which is incorporated by reference herein.
Upon leaving second oven 18 the resulting composite strand 20 is in a tacky and deformable state. That is, the temperature of the coating material thereon is such that the physical characteristics of the coating are not yet permanently set. The slightest excess in contact of the coating at that point will cause defects to be generated at the surface of the strand and/or strip the coating from the filaments of the strand. The deformation temperature of the coating material is that temperature below which the coated strand can contact guide rollers, other strands and the like without the coating being permanently deformed.
The first cooling station or zone 25 is located immediately adjacent the exit section of second oven 18. At the first station 25, a suitable gas, such as air, is directed upwardly at composite strand 20 at a volume, velocity, and temperature sufficient to cool and support the composite strand 20. That is, as composite strand 20 advances through the first cooling zone, strand 20 substantially gently floats across the top of foraminous plate 29 through which a plurality of streams of air are upwardly directed toward the strand 20.
Foraminous plate 29 is suitably attached to housing 27 having a blower or fan 31 located therein to direct streams of air through plate 29 to cool and support coated strand 20.
Upon leaving the first cooling zone 25 at least a skin has formed on the outer surface of the composite strand 20. That is, at least the outer surface of the coating on the strand is at a temperature below the deformation temperature of the coating material. It would be possible, but impractical, to entirely cool the coated strand using the above described air table technique. To decrease the amount of physical space needed to cool the strand, it is desirable to use a liquid, such as water, to cool the strand.
However, it has been found that the application of a stream or a heavy spray of water directly onto the coated strand immediately after leaving the second oven 18 produces a strand having a wrinkled surface with indentations therein. Furthermore, if a stream or spray of water was directed onto the strand 20 at a point wherein the coating only had a very thin skin at the outer surface, wrinkles and indentations still may form. Therefore, it is important that the kinetic energy with which the individual particles of the liquid, such as water, contact the composite strand 20 be as low as practically possible to reduce the tendency of the cooling liquid to wrinkle and dent the surface of the strand.
To accomplish this, strand 20 after leaving the first cooling zone 25 advances through a second cooling zone 36 having an atomized mist 50 of liquid therein. It has been found that a mist substantially consisting of tiny droplets of water having a diameter within a range from about 20 microns to about 300 microns is suitable for the purposes of this invention. It is preferred however, that the liquid droplets have a diameter within a range from about 25 microns to about 110 microns. Furthermore, it is believed that to be effective, the mass of the mist 50 within the second cooling zone 36 should be within the range of about 1.4 to about 1.8 times the mass of water that would be present in the zone if the relative humidity of the zone were 100%.
As shown in FIG. 1, the second cooling zone or mist cooler 36 is comprised of a housing 38 and a plurality of spray-heads 40 oriented above composite strand 20 to direct a body of atomized mist 50 from each spray-head 40 toward composite strand 20. Spray-heads 40 can be of any suitable type, and hydraulic atomizing nozzles, type LN 1.5, of the Spraying Systems Corporation, Randolph Street, Bellwood, Illinois have been found suitable for the purposes of this invention. A fog of water surrounds the strand as it advances through mist cooler 36. In operation, a majority of the water collects in reservoir 48 of housing 38 to be forced through piping 44 to manifold 42 and finally through spray-heads 40 by means of pump 46.
Upon leaving the second cooling zone 36 the composite strand 20 then advances through an air knife 55. Basically, an air knife is a pair of nozzles oriented to direct a pair of opposing streams of air towards the strand running therebetween. As shown, the nozzles are angled slightly in the direction of advancement of the strand passing therebetween. A suitable air knife 55 can be obtained from the Berlyn Corporation, Milbury, Massachusetts.
Basically, the strand is located in a horizontal plane by wiping dye in the second coating station and guide roller 57. That is, upon leaving the second oven 18 the strand is essentially unsupported except for the upwardly directed stream of gas at the first cooling zone 12 between the second oven 18 and the guide roller 57.
Strand 20 can be wound upon a conventional winder 59 as a wound package 61.
As shown in FIG. 2, given a uniform velocity for the advancing strand, the rate of cooling of the composite strand 20 from a point at x, to x 2 of the first cooling zone 25 is at a lower rate than the rate of cooling of the strand and the second cooling zone 36 from point x 3 to point x 4 . Also, it can be seen that the surface temperature of the composite strand 20 is below the deformation temperature T d for the coating material as any particular point on the surface of the strand passes point x 2 . Of course, the temperature of the coating material and its deformation temperature will vary according to the particular type of coating employed. In essence, however, the coating material is cooled at a first rate by directing a gas upwardly at the advancing strand to cool and support the strand and then cooling the strand at a second rate, greater than the first rate, by advancing the strand through a zone having an atomized mist of liquid therein.
If the first coating material is a plastisol containing a blowing agent and the second coating material is a plastisol that does not contain a blowing agent and is processed according to the principles of this invention, the resulting deposit strand has a substantially smooth, non-lustrous, unwrinkled outer surface over a foam core surrounding a centrally located bundle of filaments as shown in FIG. 3.
As can be seen from FIGS. 3 and 4, the system using the cooling mode according to the principles of this invention and the system employing a water spray directly after leaving the second oven, respectively, there are substantial differences in the physical characteristics of the resulting end products even though the materials employed in producing the composite strand are essentially identical. Composite strand 20, as shown in FIG. 3, is comprised of a central core of filaments 65 surrounded by a first layer of material 66 containing voids 67 which is surrounded by an unfoamed layer 70 having an outer surface 72 thereon. A continuous composite strand having a substantially smooth, non-lustrous, unwrinkled outer surface can be produced according to the principles of this invention.
However, as shown in FIG. 4, the prior art composite strand, which is produced by applying water spray of large droplets or a coherent stream of water to the coated strand immediately after leaving the second oven, is comprised of a central bundle of filaments which is surrounded by a first layer of coated material having voids therein which is surrounded by a second layer of coating material having an outer surface characterized by a substantially wrinkled appearance having indentations randomly located along the surface.
It is apparent that within the scope of the invention, modifications and different arrangements can be made other than is herein disclosed. The present disclosure is merely illustrative with the invention comprehending all the variations thereof.
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A method of processing a coated strand comprises heating the strand; directing a gas at the strand to cool and support the strand; and moving the strand through a zone having an atomized mist of liquid therein to cool the strand.
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FIELD OF THE INVENTION
[0001] The invention refers to the use of Red Nocardia Rubric Cell Wall Skeleton in the medicament preparation, especially in the preparation of medicaments for treating cervical precancerous lesion.
BACKGROUND OF THE INVENTION
[0002] Cervical precancerous lesion is a kind of undiagnosable gynecology disease that has an ability of self-limitation on one aspect, but is potential to develop further on another aspect. The transition period of development from cervical precancerous lesion to the cervical cancer is about ten years. Since persisting a long time, there is enough time to check and treat cervical precancerous lesion as early as possible. Especially the patients with light degree of cervical precancerous lesion are expected to be cured.
[0003] Cervical precancerous lesion is usually called as squamous intraepithelial lesion of cervix (SZL) or Cervical intraepithelial neoplasia (CIN). The disease is also subdivided as Atypical squamous cells (ASCUS) and atypical glandular cells (AGUS), low squamous intraepithelial lesion (LSIL) and High squamous intraepithelial lesion (HSIL). The CIN can be further classified to three classes as CIN-I, CIN-II and CIN-III.
[0004] According to modern medical theory, the development of cervical cancer is related to the infection of Human Papillomavirus (HPV), the interaction of HPV with herpes simplex virus (HSV) and fungus will further promote the pathological change of the cervical epithelial cells and gradually induce the lesion of epithelial cells and tissue into complete canceration.
[0005] Cervical precancerous lesion is such a disease that the cervical epithelial cells and the cell tissue change abnormally but have become cancer. The cervical cancer has a series of precancerous lesions whose occurrence and development are a process from quantitative alternation to qualitative alteration and from gradation to mutation. The typical type of cervical precancerous lesion is the atypical hyperplasia of cervical epithelial cells. So the degree of cell tissue lesion is determined by detecting cells and tissue.
[0006] There would be about more than 500 thousand people who suffer cervical cancer, and 200 thousand people who die from it all over the world every year. In China there are about more than 150 thousand people who suffer cervical cancer, and 80 thousand who die from it every year. According to the statistics provided by WHO, the death caused by the cervical cancer is in the second position among the death of women died from cancer all over the world and even in the first position in some developing countries. In the 21 st century, cervical cancer has been one of the most dangerous diseases affecting the health of the women of the world.
[0007] Nowadays, no effective medicament is used clinically with certain curative effect on treating cervical precancerous lesion. So the medicament for treating cervical precancerous lesion is desired for a long time. Different method is applied by different countries for confronting cervical precancerous lesion. A general means that was applied by most countries is to have women at proper age screened, those suffering from cervical precancerous lesion can be found out by cytology detection method in combination with cytohistologic detection method and HPV infection test. For the patients suffering from cervical precancerous lesion, they can be treated by cervical surface damage method or cervical lesion cutting method according to the degree of the lesion. This means can decrease the possibility of development from cervical precancerous lesion to cervical cancer.
[0008] The research directions of this field in the world are focused on two aspects: the first, consummating the detecting methods to make it more accurate and convenient; the second, improving and finding the physical and operating methods, such as applying laser, electrical surgery, and cone cutting operation and the like. The researchers in this field put focus on how to damage the cervical surface and how to cut the cervical lesion; in addition, there are some medicaments to be used for treating cervical precancerous lesion.
[0009] In China, the treatments of the cervical precancerous lesions are developing. Because people have a panic feeling of cancer, the phenomenon that dealing with patients only by cytological smearing, overdrawing cervical precancerous lesion and over-treatment is widespread. Therefore, taking use of an effective medicament treatment will change over-treatment phenomenon and will be undoubtedly a more scientific, more exact and more humanistic treatment for cervical precancerous lesion.
[0010] The goal that gynecological doctors and researchers are pursuing is to decrease the pain suffered by the patient and to keep the physiological function of the women as more as possible. In other words, the physical treatment usually by doctors now is to damage and to cut the ailing uterus; but present Red Nocardia Rubric Cell Wall Skeleton (Nr-cws) treatment is to protect and recover the cervix. Prior treatment method aims to the “disease”; while present method aims to “etiology”. So the present method is a more scientific, more advanced and more humanistic one.
[0011] In the prior art, Red Nocardia rubric Cell Wall Skeleton for External Use (Commercial Name: Nikejar) is a kind of non-specific immune regulator. The effective agents of Red Nocardia Rubric Cell Wall Skeleton (Nr-cws) include muramic acid, arabogalactan and mucopeptide, etc, with the ability of regulating the immune function of the body and increasing the activity of T cells, macrophages and NK cells, as well as inducing the production of IFN and IL, and other immune cytokines. At the present time, Nr-cws is mainly used in the treatment of cervical erosion. It also is reported in the art that Red Nocardia Rubric Cell Wall Skeleton can be used for treating infection caused by Herpes simplex virus (HZV), varicella-zoster virus (VZV), HPV and fungus.
[0012] Unexpectedly, the inventor of this invention finds that Nr-cws can be used for treating cervical precancerous lesion, settling the problem that cervical precancerous lesion can only be detected, but there is no effective medicaments to treat it, and thus making it more humanistic of the treatment. Furthermore, it is also possible for the present method to realize not only the early finding of the cervical cancer but also the early treatment thereof. The use of this medicament makes it more active of cervical precancerous lesion treatment so as to remove cervical cancer at its early stage.
SUMMARY OF THE INVENTION
[0013] The invention refers to the use of Red Nocardia Rubric Cell Wall Skeleton in the preparation of medicaments for treating cervical precancerous lesion. The cervical precancerous lesions can be classified as ASCUS, AGUS and SZL, atypical hyperplasia of cervical epithelia, wherein the preparation form of the medicament is ointment, cream, plaster, gelatin, lotion, tincture, liniment, oil agent, cataplasm, aerosol, suppository or effervescent tablet, and furthermore, the medicament can be applied topically and directly on surface of the lesion of the cervix. The medicament can be diluted with NS solution into a certain concentration solution for further application. The concentration of present medicament is 0.3 μg/ml˜1402 μg/ml, preferably 30 μg/ml to 240 μg/ml.
[0014] There is so much advantages in using medicament prepared from Red Nocardia Rubric Cell Wall Skeleton (Nr-cws) for treating cervical precancerous lesion, which include as follows:
1. Good safety: there is no side effect being observed and uncomfortable feeling being reported during the treatment. 2. Good suitability: topical application such as smearing for topical damage is used so as to avoid systematical reaction in the body. 3. Strong pertinence: the lesion occurs on skin and mucosa, while the medicament is good immunopotentiator when it is applied on these areas, and so the medicament shows strong pertinence. 4. Non-specificity: the medicament has good effect in treating every type of cervical precancerous lesion, such as ASCUS, AGUS and SZL, atypical hyperplasia of cervical epithelia. 5. Affectivity: the effective rate is 80%, and curative rate is 70%. 6. Easy to be used: only disposable medical utensils are needed in the treatment. 7. To cure as early as possible: according to the principles of cervical cancer treatment, the screening of cervical precancerous lesion starts to realize not only early finding, but also early treating for cervical cancer. 8. Easy to be extended: the present medicament does not damage the cervical epithelial tissue and is highly safe and easy to be accepted by the patients. 9.
[0024] The effect of present invention medicament is mainly focused on its immune regulation activity. Since the medicament is applied correctly or) the key lesion part for treating the etiology, it can activate the immune system of the lesion part with low immune function, recover and enhance correspondingly the immune function of patients, which is an important factor for achieving the medicament effect.
[0025] Cervical precancerous lesion is a kind of reversible disease. Some patients can recover by themselves; and others keep in the original state; but some other patients having the disease continue to develop to be worse. The key factor dominating the developing direction of disease is if the human's immunity system is normal. This further shows that the normal immunity of a human body can clear up the cervical injured epithelial cells and recover the injured cells and tissue little by little. The fact can be provided as evidence in theory to make sure that Nr-cws can be used to treat cervical precancerous lesion.
[0026] After acting on the lesion part, the present medicament can rapidly activate the immune system of the body, gather immune cells to the lesion position and increase the ability of macro phagocytes and NK cells to kill and clear up the pathogen and ailing cells. At the same time, it induces the production of IFN and IL, or other immune cytokines which can inhibit the production of infected cells and break down DNA synthesis of damaged or deficient cells, and furthermore to intermit the process of canceration of cervical epidermic tissue to prevent the development of cervical cancer. The present medicament is diluted with NS solution into a certain concentration solution for use. The concentration is in amount of 0.3˜1402 μg/ml, perferably 30 μg/ml to 240 μg/ml.
[0027] To show the present medicament effect. Nr-cws has been used in different test including cytological test, animal test and clinical observation respectively. The result shows that the effect of Nr-cws in the treatment of cervical precancerous lesion is reliable.
BRIEF DESCRIPTION OF DRAWINGS
[0028] FIG. 1A is the state of HeLa cell cycle from control group when tested by the flow cytometer, in which the rate of cells in static stage (G0-G1) is 44.44% and the rate of cells in proliferation stage (S+G2−M) is 56.56%.
[0029] FIG. 1B is the state of HeLa cell cycle from the group applying Nr-cws, in which the rate of cells in static stage (G0-G1) is 74.61% and the rate of cells in proliferation stage (S+G2−M) is 25.39%.
[0030] FIG. 2 is HeLa cell growth curve.
DETAILED DESCRIPTION OF THE INVENTION
[0031] The technical solution of the invention will be explained in details by combination with specific examples, just as follows.
[0032] HPV infected cervical cancer cells series-Hela cells are tested in groups. Cell growth curve are protracted by analyzing synthetically the vigor of cells detected by MTT of test group applied Nr-cws and blank control group, the result shows: the OD 490 light absorption value at different time for the two groups are notable different, wherein the growth of the cells is inhibited in the test group; but the growth of the cells is obvious in the control group. Therefore Nr-cws has the activity of inhibiting the HeLa cells growth.
[0033] In the experiment testing the ratio of each stage in the cell cycle by flow cytometer, cells that are inhibited in static stage (G0-G1) from test groups are more than that from control group; while the cells in proliferation stage (S+G2−M) from test group are less than that from control group. So Nr-cws has an ability of inhibiting the mitosis of cervical cancer cell, blocking the cancer cells in the G0/G1 stage and prolonging the process of the cancer cells from G1 stage to S stage, and therefore a chance is provided for injured cells to recover and stop damaged cells into DNA synthesizing stage, and to avoid correspondingly deficiency accompanied with DNA synthesis, and finally to prevent the occurrence of cervical cancer.
[0034] When the test of inhibiting cancer cells is carried in test animals, the growth of tumor in mouse from experimental group is inhibited; the growth of tumor in mouse from control group is great. There is obvious difference between the two groups, so that Nr-cws has an activity of inhibiting tumor growth.
[0035] In the clinical test, Nr-cws is used to treat the patients suffering from ASCUS, AGUS or cervical squamous epithelial lesion. After the treatment perfect results are obtained that Nr-cws has good activity for treating cervical precancerous lesion.
[0036] As required, toxicity test of Nr-cws is also carried out to the tested cells and medicament effect test of Nr-cws to the virus infected cells. In the test, African green monkey kidney cells and human embryo lung duple cells are selected as test cells. At the same time the HZV and VZV are applied as the test virus. By the tests the TD 0 and MIC of Nr-cws solution are determined as well.
EXAMPLE
[0037] 1. Detecting the inhibiting activity of anti-cancer drug-Nr-cws in inhibiting cervical cancer cells
[0000] Method:
[0038] MTT (methylthiazolyl tetrazolium) assay is used to test the vigor of cells, protract the cell growth curve, and then analysis the results by using statistics softwere.
[0039] (1) Materials and Agents
[0040] DMEM culture medium (Gibco, USA), pancreatic protein enzymes (Sigma, USA), MTT (Sigma, USA), embryo ox serum (Hyclone, USA), dimethylsulfoxide (Sigma, USA), 96 well plate (Corning company)
[0041] (2) Preparation of MTT
[0042] 5 mg/ml stock solution with PBS is prepared, followed by filtrating and sterilizing with 0.22 μm filter membrane. The solution can be kept at 4° C. in the shade for one week.
[0043] (3) Preparation of Nr-cws
[0044] Nr-cws is provided by Shenyang Sun Bell Com Biopharmaceutical Co. Ltd. The collected Nr-cws that are prepared into a certain concentration of suspension is sterilized and suspended under 0.07 Mpa for 15 min for keeping at 4° C.
[0000] Cell Growth Curve and the Cell Vigor Test
[0045] 1) HeLa cells culture: HeLa cells in the log stage are collected by Trypsin digestion. Using DMEM culture solution is to prepare cell suspension, and the cell concentration is adjusted to 5×10 4 /ml. Well-prepared cell suspension is inoculated into the 96-well culture plate, 0.1 ml/well, and 5 wells for test and control group each, wherein Nr-cws (Nikejar, produced by Shenyang Sun Bell Com Biopharmaceutical Co. Ltd.) is added into the test group to the final concentration of 30 μl/ml and is put into the 5% CO 2 culture box (37° C.) for 24-120 h, the culture solution is changed every two days. Cell growth difference between the two groups is tested at 24 h, 48 h, 72 h, 96 h and 120 h during culture via MTT assay.
[0046] 2) Cell growth Test: according to the known MMT assay, MMT solution at 20 μl/cell (5 mg/ml stock solution) at every detection point (24 h, 48 h, 72 h, 96 h and 120 h) is added, followed by putting them in the CO 2 culture box for 4 hours and discarding the upper part, DMSO, 150 μl/well is added again, and then keeping it in the culture box for 20 min. ELISA meter is used to determine the light absorption value at 590 nm after the MMT is fully dissolved.
[0047] 2) Protracting HeLa cell grow curve: the values of each light absorption at each time cluding mean value and S are obtained. The time data is taken as x-axis and the light absorption value as y-axis to protract HeLa cell growth curve.
[0048] 3) Statistics analysis: SPSS 12.0 software is applied to carry couple T-test based on the values obtained from each group.
[0000] Results
[0049] Table-1 is the OD490 light absorption values of HeLa cells at every time and Table-2 is the result of the couple T-test obtained by disposing the values by using SPSS soft statistics analysis, when p<0.05 is shown, it means that there is obvious difference between the two groups. Comparing with HeLa cell growth curve in FIG. 2 , test group is obviously different from control group, and Nr-cws can inhibit the growth of the HeLa cells; the tumor cells in test group grow slowly.
TABLE 1 OD490 light absorption values of the HeLa cells at every time point time Group 24 h 48 h 72 h 96 h 120 h Control group 0.46 ± 0.03 0.75 ± 0.01 0.98 ± 0.05 1.45 ± 0.07 2.17 ± 0.01 Test group 0.38 ± 0.02 0.53 ± 0.01 0.66 ± 0.02 1.07 ± 0.1 2.10 ± 0.06
[0050] TABLE 2 Paired Test Paired Differences 95% Confidence Std. Interval of the Std. Error Difference Mean Deviation Mean Lower Upper t df Sig. (2-tailed) Pair Control-test .21600 .13939 .06234 .04292 .38908 3.465 4 .026 group
Flow Cytometer Test
[0051] 1) Cell culture. HeLa cells to log stage in DMEM containing 10% blood serum are cultured. After digesting it with 0.25% pancreatic enzyme digestion, digested Hela cells are added into 24-well plate at 5000 cells/well to 0.1 ml/well, and 3 wells for test group and control group each. PBS solution is used to wash twice after cells adhering to the wall, followed by culturing in the non-serum culture medium for 12 h to realize synchronization of the cells. The culture medium is exchanged with 10% serum DMEM culture medium to continue curing. Nr-cws is adding into test group to achieve a final concentration of 30 μg/ml. The cells are further cultured in 5% CO2 culture box (37° C.) with changing the solution every two days. Flow cytometer is used to determine the difference of DNA synthesizing between the two groups after one week from the day adding the medicament.
[0052] 2) Cell preparation: The cells are digested with 0.25% pancreatic enzyme and collected, and then washing them twice with PBS solution. The supernatant is discarded after centrifugation. 0.5 ml cell suspension is kept, and is dispersed by concussion. The cells are injected rapidly into 70% cold ethanol at 4° C. and are kept at the same temperature for at least 18 hours. The cells finally are centrifuged and collected and then RNA enzyme (with a final concentration of 50 μg/ml), containing 0.1% Triton X-100 is added, followed by keeping them in the 37° C. water bath for 30 min and then putting them in the cold ice. The action of RNA enzyme is quenched and washed with PBS solution twice. Propidium iodide (PI) with a final concentration of 50 μg/ml is added and further kept in shade of the cold ice bath for at least 30 min. The cells are filtrated by using 40 μm nylon net before use in the next step.
[0053] 3) The results: The difference of the DNA synthesis between the test group and the control group are compared. The cells at the stationary stage in the test group are more than that in the control group. The cells at the replicating stage in the test group are less than that in the control group. So it shows that Nr-cws has an activity of inhibiting cervical cancer cells. (Data is shown in the following table)
Analysis on the ratio of every stage during Hela cell proliferation Group/stage (G0-G1) stage S stage (G2-M) stage Control group 44.44% 47.1% 8.45% Test group 74.61% 20.30% 5.1%
[0054]
2. Inhibitation of Nr-cws to the tumor cell growth in mouse
Group/standard
Length*width (cm)
Weight (g)
Control group (1)
2.2*1.8
2.05
Test group (1)
1.7*1.2
0.7
Control group (2)
2.4*1.7
3.02
Test group (2)
1.5*0.7
0.54
[0055] Culture density of cell is 10 6 /mouse and the tumor can be seen by our naked eyes after one week (8-9 days).
[0056] The medicament (with a concentration of 30 μg/ml) is injected into the tumor in clinical amount, twice/week. The tested mouse is killed after 4 weeks and the length, width and weight of the tumor are measured. The results are showed in the above tables. The growth of the tumor for the test group is slow definitely. The mean weight of tumor for the test group is 0.62 g which is obviously less than that for the control group (2.54 g), having statistic difference.
[0057] 3. The therapy effect of Nr-cws on clinical patients by local use
[0058] The therapy effects of Nr-cws on 10 patients suffering from cervical lesion are showed in table 3. The medicament concentrations for the 10 patients are respectively 30 μg/ml, 60 μg/ml, 120 μg/ml and 240 μg/ml. For the patients, 6 among them are at the age of 28-35, 3 among them are older than 35, one is 26 years old, wherein, 3 patients are suffering from HPV infection meanwhile. After treating with Nr-cws at different dose for different time, 7 patients are cured, 1 patient's condition is relieved and two patients' inflammation is alleviated. For the 3 patients that are not cured, the reason is believed that the condition is very serious and complication is followed, as well as short treatment period. Even is such a disadvantage case, the condition of 3 HPV patients turn negative. When Nr-cws is used for treating cervical precancerous lesion, the curative rate is 70% and effective rate is 80%. So it can be concluded that Nr-cws has a good effect on the treatment of ASCUS, AGUS and atypical hyperplasic lesion. After being treated with Nr-cws the cervical lesion epidermal cells could be cleared up and the injured cervical epithelial tissue could be recovered. Meanwhile, HPV infection can be turned into negative result.
TABLE 3 The observation table of the treatment for the cervical precancerous lesion Adminis- Treat- Post- Num- Cervical tration ment treatment ber Name Age lesion way period Detection 01 MAFA* 36 ASCUS Outward, 2 Cure pushing 02 JIHO* 50 ASCUS Outward, 2 Cure pushing, injection 03 WAXU 30 AGUS Outward, 2 Cure pushing 04 LICE 28 ASCUS Outward, 2 Cure pushing 05 XYLI* 26 CIN-I Outward, 2 Cure pushing, injection 06 GANA 28 ASCUS Outward, 3 Cure pushing 07 ZHYE 35 Atypical Outward, 1 Relieve the hyper- pushing inflammation plasia, serious erosion 08 LIXI 38 ASCUS, Outward, 2 Relieve the cervical pushing inflammation lesion 09 LIJI 34 CIN-I Outward, 2 Cure pushing 10 CEMH 29 Atypical Outward, 1 Atypical hyper- pushing epithelia plasia Noted: *shows that the patient suffers from HPV infection meanwhile.
[0059] 4. The medicament effect test of Nr-cws against virus infected cells
[0060] 1) Toxicity of Nr-cws to the cells:
[0061] Nr-cws solution is provided by Shenyang Sunbellcom Biopharmaceutical Co. Ltd. The toxicity of Nr-cws to the cells including VERO cells and 2 BS cells have been observed already.
[0062] (1) Toxicity test of Nr-cws solution to 2 BS cells (the results are mean values of three tests).
[0063] Tested medicaments: Nr-cws solution CPE method: the maximum nontoxic concentration (TD 0 ) is 625 μg/ml; median nontoxic concentration (TD 50 ) is 1667 μg/ml. In the MMT method the TD 0 is 625 μg/ml; TD 50 is 1417 μg/ml.
[0064] (2) Toxicity test of Nr-cws solution to VERO cells (the results are mean values of three tests).
[0065] The medicaments: Nr-cws solution CPE method: TD 0 is 1042 μg/ml; TD 50 is 2220 μg/ml. In the MMT assay, TD 0 is 958 μg/ml; TD 50 is 2376 μg/ml.
[0066] 2) Inhibitation of Nr-cws to the infected cells:
[0067] (1) The inhibitation of Nr-cws solution to HSV-I type virus (the results are mean values of three tests).
[0068] {circle around (1)} Group treated with once administration:
[0069] Tested medicaments: Nr-cws solution CPE method: the median inhibitory concentration (IC 50 ) is 0.145 μg/ml; maximum inhibitory concentration (MIC) is 0.313 μg/ml; therapeutic index (TI) is 1997. In the MMT method the IC 50 is 0.124 μg/ml; MIC is 0.30 μg/ml; TI is 2111.
[0070] {circle around (2)} Group treated with three times administration:
[0071] Tested medicaments: Nr-cws solution CPE method: IC 50 is 0.116 μg/ml; MIC is 0.3 μg/ml; TI is 1997. In the MMT method the IC 50 is 0.11 μg/ml; MIC is 0.313 μg/ml; TI is 1997.
[0072] (2) Inhabitation of Nr-cws solution to VZV virus (the results are mean values of three tests).
[0073] {circle around (1)} Group treated with once administration:
[0074] Tested medicaments: Nr-cws solution CPE method; the IC 50 is 0.583 μ/ml; MIC is 1.25 μg/ml; TI is 500. In the MMT method the IC 50 is 0.456 μg/ml; MIC is 0.846 μg/ml; TI is 779.
[0075] {circle around (2)} Group treated with three times administration:
[0076] Tested medicaments: Nr-cws solution CPE method: the IC 50 is 0.308 μg/ml; MIC is 1.25 μg/ml; TI is 500. In the MMT method the IC 50 is 0.25 μg/ml; MIC is 0.342 μg/ml; TI is 1827.
[0077] Conclusion of the Test:
[0078] {circle around (1)} TD 0 of Nr-cws to the tested cells is: VERO 1042±360 μg/ml, 2BS 625±0 μg/ml.
[0079] {circle around (2)} MIC of Nr-cws to the infected cells is:
[0080] For group treated with once administration: 0.3±0 μg/ml,
[0081] For group treated with three times administration: 0.313±0 μg/ml.
[0082] The results are showed in table 4.
TABLE 4 Toxicity test results of Nr-cws solution to VERO and 2BS cells VERO 2BS TD0 TD50 TD0 TD50 Medicament Test method μg/ml μg/ml μg/ml μg/ml Nr-cws Change of Cell 1042 ± 360 2220 ± 242 625 ± 0 1667 ± 0 solution morpha MTT method 958 ± 0 2376 ± 213 625 ± 0 1417 ± 144.3
[0083]
TABLE 5
Efficiency test of Nr-cws solution against HSV-I type virus and VZV virus.
Group treated with once
Group treated with three
administration
times administration
Virus
Medicament
Method
IC50
MIC
TI
IC50
MIC
TI
HSV-I
Nr-cws
CPE
0.145 ± 0.01
0.313 ± 0
1997
0.116 ± 0.01
0.313 ± 0
1997
Solution
method
MTT
0.124 ± 0.04
0.30 ± 0
2111
0.11 ± 0.01
0.313 ± 0
1997
method
Noted:
the unit of IC50 and MIC is μg/ml, the results showed in the table are the mean values of three te
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The use of Red Nocardia Rubric Cell Wall Skeleton in the preparation of medicaments for treating cervical precancerous lesion is disclosed in the present application.
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FIELD OF THE INVENTION
[0001] This invention relates to improvements in products and processes for cleaning up oil, chemical, or other hydrocarbon spills, and cleaning up the environment where such spills have occurred.
BACKGROUND
[0002] When an oil, chemical, or other hydrocarbon spill occurs in water an effort is made to absorb the oil, chemical, or other hydrocarbon and recover or retrieve it. This is done with the use of straw, hay, sawdust, absorbent pads or booms, “Kitty Lifter” and several other adsorbents. However these adsorbents hold water as well as the oil. They therefore become saturated with a mixture of water and oil, chemical, or other hydrocarbon and sink. Generally speaking, only a small portion of the spilt oil, chemical, or other hydrocarbon is removed from the environment and recovered for further processing. The remainder of the oil, chemical, or other hydrocarbon spill is burnt, dispersed or treated with harsh chemicals, which themselves often cause further environmental damage. Much of the oil, chemical, or other hydrocarbon is trapped in the sunken adsorbent and may be slowly released into the water over a period of many years causing long-term environmental damage.
[0003] When an oil, chemical, or other hydrocarbon spill occurs on land a similar process using adsorbent booms or embankments is used but any excess which is not readily collected or retrieved is frequently washed away with water and/or detergents into the nearest drain, or burnt, or dispersed over a wide area.
[0004] One example of an environmentally sympathetic product used in the retrieval of oil, chemicals or other hydrocarbons from the environment is, for example, a product made from recycled waste plant fibres which are hydrophobic and oleophilic.
[0005] Other environmentally unsympathetic solutions for oil spills, for example, include the use of surfactants and dispersion agents.
[0006] The need for better recovery products and processes has been recognised worldwide. To date there has been no suitable product that will collect the oil, chemical, or other hydrocarbon, hold it in suspension, and cause it to separate from the water or soil so that it can be recovered or retrieved. It is an object of this invention to provide recovery products and processes suited to the efficient removal of oil, chemical or other hydrocarbon spills from a polluted environment.
SUMMARY OF THE INVENTION
[0007] In one aspect of the invention, there is provided an adsorbent polymeric composition which is oleophilic and capable of adsorption of other chemicals and hydrocarbons from both land and water, the adsorbent composition including polyethylene/vinyl acetate copolymer, catalyst, cross-linking agent, lubricant, blowing agent and a bulking agent.
[0008] One advantage of the composition according to the invention is that it is biodegradable and will be broken down by the action of ultraviolet light such as the ultraviolet rays of the sun. The final products of this biodegradation process are environmentally friendly and suitable for marine and/or land use.
[0009] In a preferred embodiment of this aspect of the invention, the adsorbent composition additionally includes one or more of anti microbial and antifungal agents, odour-masking agents, wetting agents and other suitable additives such as, for example, colouring agents and/or dyes.
[0010] A suitable catalyst is any substance or chemical that is capable of starting or kicking the cross linking of the polymeric composition during preparation and may be, for example, one or more of zinc stearate, lead, chromium, copper, cobalt, nickel, silica or zinc oxide or compounds and ionic forms thereof. Zinc oxide is preferred.
[0011] Preferably the zinc oxide is present in amounts of 0.2-2% w/w.
[0012] Preferably the polyethylene/vinyl acetate copolymer is made up of between about 2-30% vinyl acetate and is present in amounts of about 75-95% w/w. Preferably the vinyl acetate is ethyl vinyl acetate. The proportion of ethyl vinyl acetate present may be varied so as to ease the handling of the product according to the invention.
[0013] The melt flow index of suitable polyethylene/vinylacetate copolymers may be varied according to need, and according to the mode and manner of application. Preferably, the melt flow index of the copolymer is 0.2-600 g/10 min.
[0014] One suitable polyethylene/vinylacetate copolymer is Escorene™ T LDPE available from a variety of sources.
[0015] A suitable cross linking agent is any substance or chemical that is capable of linking a cellular structure together and may be, for example, one or more diacyl peroxide, dialkyl peroxide, ketone peroxide, peroxydicarbonates, peroxyesters, tertiary alkyl hydra peroxides, tertiary amyl peroxides, acid chlorides, hydrogen peroxides whether they be organic or inorganic or dicumyl peroxide.
[0016] The cross linking agent is preferably peroxide, and more preferably, dicumyl peroxide. The peroxide is preferably used as a 99% solution but may be as low as a 20% solution. It is present in amounts of about 0.2-1.8% w/w.
[0017] One preferred lubricant according to the invention is a fatty acid, preferably stearic acid, but it will be appreciated, for example, that other fatty acids such as palmitic acid may be suited to the process. The lubricant may be present in amounts of about 0.5-1.75% w/w.
[0018] A suitable blowing agent may be any substance which alone or in combination with other substances is capable of producing a cellular structure in the adsorbent composition and is preferably present in amounts of about 1-7% w/w. Blowing agents include compressed gases that expand when pressure is released, soluble solids that leave pores when leached out, liquids that develop cells when they change to gases, and chemical agents that decompose or react under the influence of heat to form a gas. Chemical blowing agents range from simple salts such as ammonium or sodium bicarbonate to complex nitrogen releasing agents. A preferred blowing agent is azodicarbonamide.
[0019] Suitable bulking agents may include one or more of calcium carbonate, talc or any other substitute for these substances and may be present in amounts of about up to 25% w/w.
[0020] Suitable odour masking agents may include, for example, one or more of ti-tree oil, lavender oil and like substances and can be present in amounts of about up to 1% w/w. These substances, for example ti-tree oil, may also act as anti fungal and anti microbial agents.
[0021] Wetting agents may be useful in the manufacturing process to prevent dust generation and might be present in amounts of about up to 29% w/w. Suitable wetting agents may include, for example, white oil. This substance, for example, may have a secondary function as, for example, an insecticide.
[0022] In a second aspect of the invention there is provided a method of manufacture of an adsorbent composition for use in retrieving and recycling oil, chemicals and hydrocarbons from land or water environments, the method including the steps of forming an admixture for example, preferably in the form of a crepe of the components of the adsorbent composition of this invention, subjecting said admixture to pressure and optionally, temperature and forming the resultant cake into a shape or form suited to the environment of application of the composition.
[0023] Preferably, the admixture is treated at a temperature of between 70-400° C. and at pressure of about 12000 tonne/m 2 . The duration of said treatment will vary according to the volume of adsorbent composition being produced and the surface area of the vessel in which the treatment is occurring.
[0024] The adsorbent composition may be granulated after the heat and pressure treatment, but this granulation may also take place during the heat and pressure treatment, for example, by use of injection moulding equipment which forces the formation of a particularised product. Alternatively, the product may be shaped so as to form a sweep, boom or case as needs be. The adsorbent composition may also be applied in a liquid form in which case it will be necessary to add a co-solvent to the system to solubilise the composition. This form of the adsorbent composition is especially useful in environments where high wind is a factor.
[0025] In a third aspect of the invention the adsorbent composition prepared according to the method described hereinabove, having the characteristics described may be incorporated into a product such as a filter for off-site treatment of contaminated water or soil. In this aspect, the polluted water or soil could be removed by any suitable collection means and transported to said filter for treatment. The filter could then be treated for recovery of the pollutant and adsorbent composition, or the gelatinous mass arising from the treatment removed from the filter and treated independently of any filter structure.
[0026] In a fourth aspect of the invention, there is provided a method of treating an environment to remove an oil, chemical or other hydrocarbon pollutant including applying to said environment an adsorbent composition according to the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0027] When the composition according to the invention, being an inert adsorbent, comes into contact with oil, chemical, or other hydrocarbon, it collects, and forms a gelatinous mass with, the oil, chemical, or other hydrocarbon without any chemical reaction taking place between the composition according to the invention and the oil, chemical, or other hydrocarbon. This allows the process to be easily reversed so that the gelatinous mass may be separated into adsorbent composition and the oil, chemical, or other hydrocarbon without the oil, chemical, or other hydrocarbon being affected by its contact with the adsorbent composition according to the invention.
[0028] When an oil, chemical, or other hydrocarbon spill occurs on water the oil, chemical, or other hydrocarbon tends to float for some time. The composition according to the invention after application by spreading or spraying on to the spill, will collect the oil, chemical, or other hydrocarbon suspended in or on water and hold it in suspension in the form of a gelatinous mass constituted by the oil, chemical or other hydrocarbon impregnated adsorbent. This gelatinous mass will not appreciably absorb water and hence in the instance where it is used to treat chemical or oil spills in or on water, will continue to float so that it can be recovered or retrieved. Surfactant may be used to at least partially fluidise the adsorbent composition to assist in spreading or spraying. The recovered or retrieved mass is then treated so as to desorb the oil, chemical, or other hydrocarbon for further treatment or processing. The adsorbent according to the invention may then be cleaned for further use.
[0029] The floating mass is easily recognised and can be recovered or retrieved by normal means including, but not limited to, suction, scoop, filter, or water-porous conveyor belt or is simply floated or scraped off the water. The oil, chemical, or other hydrocarbon may be recovered by means of compression, suction, centrifugal force, or any other suitable type of filter which will not be detrimentally affected by the composition itself, the oil, chemical, or any other hydrocarbon, the water or a combination of the oil, chemical, or other hydrocarbon and the water at the operating temperature and environmental conditions.
[0030] When an oil, chemical, or other hydrocarbon spill occurs on land the oil, chemical, or other hydrocarbon may remain on the surface for a time, or penetrate into the surface layer at a rate determined by the type of soil or substrate and by the type of oil, chemical, or other hydrocarbon in the spill. Chemical reactions between the contents of the spill and the soil or substrate will also affect the rate of penetration.
[0031] In a similar fashion to the mechanism of treatment and retrieval of oil, chemical and hydrocarbons from water, on land, after application by spraying or spreading, the adsorbent will adsorb the pollutant oil, chemical or hydrocarbon waste and hold it in the form of a gelatinous mass. This mass may then be recovered or retrieved by suitable mechanical means of a scoop, suction or by other suitable means or washing it into a recovery or retrieval point with the use of available water and treated so as to desorb by compression, suction, centrifugal system, or any other type of suitable filter, the oil, chemical or hydrocarbon pollutant for further treatment or processing.
[0032] The filter removes the collected oil, chemical, or other hydrocarbon out of the gelatinous mass and recovers or retrieves it for storage, transport or further processing. The composition according to the invention, being substantially, if not totally, cleaned in the filter process, can be immediately returned to the oil, chemical, or other hydrocarbon spill and reused for a number of cycles.
[0033] In an embodiment in which the oil, chemical, or other hydrocarbon has leached, or penetrated, or soaked into the soil or environment, cleaning and retrieval is commenced by removing the contaminated soil from its natural or initial location into a water-filled container or bath thus allowing the oil, chemical, or other hydrocarbon to be released into the water. It may be necessary to adjust the temperature of the mixture in the bath and/or cause some agitation of the mixture or use other methods to enhance the release of the oil, chemical, or other hydrocarbon from the soil into the water.
[0034] The mixture is then treated as a water-based spill of oil, chemical, or other hydrocarbon by spraying or spreading the adsorbent composition according to the invention onto the mixture by any suitable means and allowing it to collect the oil, chemical, or other hydrocarbon. The resultant gelatinous mass is recovered or retrieved by means of a scoop, suction, floatation, or other suitable means and fed into a compression, suction, or centrifugal, or other type of suitable filter. The filter removes the collected oil, chemical, or other hydrocarbon out of the gelatinous mass and recovers or retrieves it for storage, transport or further processing. The composition according to the invention, being substantially, if not totally, cleaned in the filter process, can be immediately returned to the bath and reused for a number of cycles. When the oil, chemical, or other hydrocarbon has been removed from the bath, the soil can then be removed from the water and soil mixture by any suitable means and dried so that it can be returned to its original location or to an alternate site.
[0035] In the event that a small amount of the adsorbent composition according to the invention inadvertently remains in the environment as a result of not being completely recovered or retrieved, the adsorbent composition will be degraded by the ultraviolet light of the sun so that no long-term harm will be done to the environment.
[0036] In a preferred embodiment the composition according to the invention may be made by admixing suitable proportions of calcium carbonate, ethyl vinyl acetate, stearic acid, blowing agent, white oil, ti-tree oil, lavender oil, dicumyl peroxide, and zinc oxide in a roller mill, and then subjecting the mixture to a temperature between 70-400° C. and pressure of between approximately one thousand (1,000) and twelve thousand (12,000) tonne per square metre in a seated vessel to allow the chemicals to react to form a polymeric solid of suitable particle size.
[0037] The step of admixing the components of the composition is exothermic. When a polyethylene/vinylacetate of low MFI is used e.g. about 2 g/10 min, a temperature of about 70-160° C. is desirably maintained in the roller mill. When copolymers of higher MFI are used e.g. 30-600 g/10 min, cold milling is required and it will not be necessary to perform the admixing step at elevated temperature.
[0038] During the manufacturing process, other additives may be added according to need and the conditions of the manufacturing process can be altered to enhance the properties of the product or to alter the properties to make the product suitable for other applications. The product may then be granulated by known means if necessary and is subsequently packaged.
[0039] In its natural form the composition according to the invention comes in the form of white powder or granule. It may be possible to colour the composition, but care needs to be taken in the development of a colouring agent so that the basic chemical, physical and electrical properties of the composition according to the invention are not adversely affected. Colouring may be used to identify different grades or particle sizes of the product for use in different environments or for different types of spill.
[0040] One preferred composition according to the invention is as follows:
Component kg polyethylene/ethyl vinyl acetate (18%) 25.00 [MFI-2 g/10 mins] Azodicarbonamide 0.89 Dicumyl peroxide 0.18 Stearic Acid 0.20 Zinc Oxide 0.240 Calcium carbonate 3.570
This may be scaled up according to need.
EXAMPLES 1-11
[0041] Other examples of composition according to the invention are as follows:
Amount (g) FUNCTION COMPONENT 1 2 3 4 5 6 7 blowing agent Azodicarbonamide (AC2) 778 700 530 488 800 773 758 catalyst Zinc oxide 195 240 198 156 206 198 226 lubricant Stearic acid 150 150 150 150 150 150 150 cross linker (X/L 99%) dicumyl 118 118 106 148 116 106 112 peroxide bulking agent Calcium carbonate 2248 2100 2248 2248 2248 2248 2248 copolymer EVA FL 00206 — 16000 — 16000 — — — EVA FL 00209 — 16000 — 16000 — — — EVA FL 00212-218 16000 — 16000 16000 — 16000 16000 EVA VL 00328 — — — — 16000 — — colourant 200 200 75 200 200 200 200 Amount (g) FUNCTION COMPONENT 8 9 10 11 blowing agent Azodicarbonamide (AC2) 700 443 907 890 catalyst Zinc oxide 180 156 188 240 lubricant Stearic acid 150 150 150 200 cross linker (X/L 99%) dicumyl 118 148 115 180 peroxide bulking agent Calcium carbonate 2248 2248 2248 3570 copolymer EVA FL 00206 16000 — — EVA FL 00209 — — 16000 EVA FL 00212-218 — — — 25000 EVA VL 00328 — 16000 16000 colourant 200 200 200
[0042] The composition according to the invention has been tested with controlled spills on a number of oil, chemical, or other hydrocarbon based products and is found to be able to collect oil, chemical, or other hydrocarbon products ranging from, but not limited to, crude oil through refined oils and fuels to paraffins, waxes, animal and vegetable oils and other hydrocarbons.
EXAMPLE 12
[0043] In a test conducted by The Murray-Darling Freshwater Research Centre, of New South Wales, Australia, to ascertain the rate of recovery of oil from a contaminated water sample, the following procedure was conducted.
[0044] 200 ml of distilled water was weighed into a beaker and 20 ml of oil (unspecified) was added. In 1 g increments, a sorbent composition according to example 11 was added until saturation occurred or until the desired result was achieved. The water with oil and product added was stirred to stimulate a wave action. The sorbent product/oil composite was removed with a filter scoop and weighed. The weight of the remaining water was recorded. The oil in the product sample was then analysed using gravimetric method APHA5520B.
[0045] The following results were achieved:
Sample A B C oil/grease mg/l 7.5 13.0 9.0 Petroleum hydrocarbon mg/l 1.0 6.0 2.0
EXAMPLES 13-16
[0046] The following tests were conducted by the Industrial Research Institute of Beirut, Lebanon to test the ability of a sorbent composition according to example 11 to adsorb oils and other hydrocarbons spilled in sand, stones and water.
EXAMPLE 13
Contaminated Sand and Rocks
[0047] Two kilograms of mixed sand and stones contaminated with fuel oil were mixed with 100 g of the sorbent material for 15 minutes. Water at 35° C. (2.5 litres) was added and mixed for another 15 minutes. Floating material was skimmed with a sieve. Sand mixture, remaining water and the skimmed material (weighed 321 g on air dried basis) were tested for oil and grease content. Remaining water was also tested for Biochemical Oxygen Demand (BOD 5 ).
[0048] The results were found as follows:
Skimmed Sand material (on mixture Water air dried basis) Oil and grease 7.70 g/kg <0.1 mg/l <0.1 mg/l (before treatment) Oil and grease 291 mg/kg 3 mg/l 20 g/kg (after treatment) BOD 5 as O 18 mg/l
EXAMPLE 14
Sand Mixture Containing 200 g/kg of Fuel Oil
[0049] A 400 g sample of “clean” sand and stones mixture was mixed with 100 g of fuel oil and 20 g of the sorbent material.
[0050] Water at 35° C. (200 ml) was added and mixed for 15 minutes.
[0051] Floating material was skimmed with a sieve (weighed 155 g on air dried basis). Samples were tested and results were found as follows:
Skimmed Sand material (on mixture Water air dried basis) Oil and grease 200 g/kg <0.1 mg/l — (before treatment) Oil and grease 3.5 g/kg 54 mg/l 303.6 g/kg (after treatment)
EXAMPLE 15
Sea Water Containing 200 g/l Fuel Oil
[0052] 400 g of fuel oil were mixed with 1.5 litres of sea water.
[0053] 100 g of the sorbent material was added and mixed for 15 minutes.
[0054] Floating material was skimmed with a sieve (weighed 485 g on air dried basis). Water and the recovered floating material were tested for oil and grease. Water was also tested for Biochemical Oxygen Demand (BOD 5 ).
Skimmed material (on Water air dried basis) Oil and grease 200 g/l (before treatment) Oil and grease 23 mg/l 276 g/kg (after treatment) BOD 5 as O 19.5 mg/l —
EXAMPLE 16: Sand Containing 380 g/kg Fuel Oil
[0055] 400 g of sand and stones were mixed with 250 g of fuel oil. 35 g of the sorbent material were added along with 1 litre of water. Floating material was skimmed with a sieve (weighed 450 g on air dried basis). Tests were performed as described in Ex. 13.
Skimmed Sand material (on mixture Water air dried basis) Oil and grease 385 g/kg <0.1 mg/l <0.1 mg/kg (before treatment) Oil and grease 58 g/kg 725 mg/l 413 g/kg (after treatment)
EXAMPLE 17
[0056] The following trial on a sorbent composition according to example 11 was conducted by Science Applications International Corporation (SAIC Canada).
[0057] The purpose of these tests was to evaluate the sorbent's performance as per the Environment Canada Sorbent Performance Test Program, using ASTM Standard Method of Testing Sorbent Performance of Adsorbents (F726-99). This protocol is based, in part, upon test methods listed in the Canadian General Standards Board Method for Testing Sorbents (CAN/CGSB-183.2-4), and internal standards initially developed in part by the Emergencies Engineering Technologies Office (formerly the Emergencies Engineering Division) of Environment Canada.
[0000] Procedures
[0058] Materials and Equipment
[0059] Sorbent Description
[0060] The following brief description of the sorbent is based on information supplied by the manufacturer and from the quantitative and qualitative observations obtained during testing. Such information is provided since it may be useful when interpreting or comparing results.
[0061] The sorbent supplied for testing is described as a granular (non-metallic) material. Two samples of the sorbent particulate were received, one fully white and the other with a coloured fleck (indicated as being for safety reasons—made for defence and government departments only). The coloured fleck sample was used for testing purposes—having a measured density of approximately 0.090 g/cm 3.
[0062] Test Liquids
[0063] The following test liquids were used:
Density Viscosity Temperature Test Liquid (g/cm 3) (cP) (° C.) Diesel 0.829 3 20 Light Crude Oil 0.944 290 20 Heavy Crude Oil 0.995 2050 20
[0064] Equipment
[0065] The following apparatus was used to measure physical and chemical properties of the sorbent and/or test liquids.
[0066] Density Anton-Paar DMA 35 hand-held digital densitometer. The unit contains a borosilicate U-shaped oscillating tube and a system for electronic excitation, frequency counting and display. An injected sample volume is kept constant and is vibrated. The density is calculated based on a measurement of the sample oscillation period and temperature. Replicate measurements are conducted and the average density is reported.
[0067] Viscosity Brookfield DVII+ viscometer powered by a precision motor and equipped with a beryllium copper spring to measure torque. The degree to which the spring is wound is proportional to the viscosity of the fluid. Several of the following spindles are used per measurement when possible: LVT spindles (#1, #2, #3, #4). Ultra Low viscosity Adapter (ULA) and spindle, Small Sample Adapter (SSA) and spindles SC4-18, SC4-31.
[0068] Models are stated to be accurate to within 1% of their full scale range when employed in the specified manner. Readings should be reproducible to within 0.2% of full scale subject to environmental conditions such as variation in fluid temperature. Calibrations are conducted with Brookfield Standard Fluids.
[0000] Mass Sample mass is measured using a Mettler PM 4000 analytical balance. The scale resolution is 0.01 g and the reported reproducibility is 0.01 g.
[0000] Test Cells: Pyrex 190 mm (diameter)×100 mm (depth) crystallizing dishes are the typical test cells used although other vessels can be used in order to accommodate special materials
[0000] Weighing Pans Non-stick coated pans of 20 cm diameter.
[0000] Mesh Basket Mesh baskets (mesh size approximately 1.1 mm diameter) are used to contain and drain Type II (particulate) samples.
[0000] Shaker Table An Eberbach Corporation shaker table, modified to hold three 4 L jars is used to agitate samples. The table is set at a frequency of 150 cycles per minute with an amplitude of 3 cm.
[0069] Test Protocol
[0070] The following summary test protocol which is applicable to Type II (particulate) sorbents was utilized.
[0071] The Dynamic Degradation Test
[0072] This procedure is designed to determine the buoyancy, hydrophobic and oleophilic properties of a sorbent sample under dynamic conditions. A sorbent sample is placed in a sealed 4L jar which is half-filled with water. The jar is placed on its side and mounted on a shaker table, set at a frequency of 150 cycles per minute at an amplitude of 3 cm, for a duration of 15 minutes. The contents of the jar are allowed to settle for a period of 2 minutes, after which observations pertaining to the condition of the water and the sorbent sample are recorded. If greater than 10% of the sorbent is observed to sink or the water column is rendered contaminated with sorbent particles, then the sorbent is designated with a Failure and is not recommended for use on open water. The sorbent samples are removed from the jar and the water pick-up ratio is determined.
[0073] 3 mL of oil is added to the surface of the test jars which have been half-filled with water. The wetted sorbent samples used in the beginning of this procedure are returned to the jar and the container is placed on its side and mounted on the shaker table for an additional 15 minutes. The contents of the jar are allowed to settle for a period of 2 minutes and observations pertaining to the existence of any oil sheen on the surface of the water is noted.
[0074] The Oil Adsorption—Short Test (15 Minutes)
[0075] This procedure is designed to determine a sorbent's pick-up ratio when placed in a pure test liquid under stagnant conditions. The sorbent sample is initially weighed and the value recorded. A test cell is filled with a layer of test liquid to a depth of approximately 80 mm. The sorbent sample is placed in a fine mesh basket and lowered into the test cell. After 15 minutes, the sorbent is removed from the cell and allowed to drain for 30 seconds (sorbents tested in Heavy Oil are drained for 2 minutes). The sorbent is then transferred to a weighing pan and the weight recorded. All tests are conducted in triplicate.
[0076] The Oil Adsorption—Long Test (24 Hours)
[0077] This procedure is designed to determine a sorbent's pick-up ratio when placed in a pure test liquid under stagnant conditions. The sorbent sample is initially weighed and the value recorded. A test cell is filled with a layer of test liquid to a depth of approximately 80 mm. The sorbent sample is placed in a fine mesh basket and lowered into the test cell. After 24 hours, the sorbent is removed from the cell and allowed to drain for 30 seconds (sorbents tested in Heavy Oil are drained for 2 minutes). The sorbent is then transferred to a weighing pan and the weight recorded. All tests are conducted in triplicate.
[0078] Results and Discussion
[0079] Test results are as follows:
[0080] The Dynamic Degradation Test
[0081] After shaking for 16 minutes and settling for 2 minutes, the bulk of the sorbent material was observed to be floating on the water column. The bulk water remained clear, with little evidence of clouding or colour change.
[0082] After shaking for 15 minutes following the addition of 3 mL of oil, there was little evidence of clouding in the water column, however, trace amounts of oil sheen remained on the water surface. Due to these factors the sorbent was deemed to have passed this test and is therefore recommended for use on waterways and for land applications.
DYNAMIC: DEGRADATION PRE-TEST 1 2 3 Temperature (° C) 21 21 21 Sample weight (g) 6.13 6.19 6.50 Weight of wetted sorbent (g) 33.66 35.74 21.61 Initial water pickup ratio (g liquid/g sorbent) 4.5 4.8 2.3 Average liquid up-take (g liquid/g sorbent) 3.9 Standard Deviation (g liquid/g sorbent) 34.7% Buoyancy test (Pass/Fail) Pass
[0083] Comments:
[0000] sorbent floats
[0084] lost a significant amount of sorbent through filter.
DYNAMIC: DEGRADATION TEST 1 2 3 Temperature (° C.) 23 21 19 Sample weight (g) As above Persistence of oil sheen on surface (Yes/No) Yes Yes Yes
[0085] Comments
[0000] sorbent floats freely/water remains clear
[0000] VERY SMALL oil sheen remains on surface: stirred containers after 2 minutes and sheen got smaller
[0086] List of Possible Comments:
[0000] Sorbent: floats freely, 25%/50%/75% submerged; sorbent still floating, sinks, dissolves.
[0000] Water: remains clear, becomes slightly coloured, becomes cloudy, becomes murky.
[0087] Oil: sheen remains on surface, no sheen on surface.
Density Viscosity Temperature COMMENTS Oil Used (g/cm 3 ) (cP) (° C.) Medium 0.944 290 20 (Crude oil)
[0088] The Oil Adsorption—Short Test
[0089] Following completion of the above test, new sorbent samples were exposed to a range of test oils. Based on 15 minute exposure and 0.5 or 2 minute drain periods, the sorbent was observed to have the following oil sorption ratios:
Oil Viscosity Pick-up ratio Oil Type (cP) (g oil/g sorbent) Diesel fuel 3 7.0 Medium oil 290 10.7 Heavy Oil 2050 5.2
[0090] The Short L-Test (15 minutes) is the designated test which indicates standard performance.
Short L Test - 15 minutes Liquid #1 Liquid #2 Liquid #3 Sample Sample Sample 1 2 3 1 2 3 1 2 3 Temperature (° C.) 19 19 19 19 19 19 19 19 19 Sample weight (g) 5.63 5.71 5.61 6.10 6.07 6.43 4.87 5.99 4.81 Wet sample weight (g) 40.99 47.05 48.06 70.14 72.12 74.69 34.21 33.17 28.67 Initial Sorption Capacity 6.28 7.24 7.57 10.50 10.88 10.62 6.02 4.54 4.96 (g liquid/g sorbent Average liquid up-take 7.0 10.7 5.2 (g liquid/g sorbent) Standard Deviation 9.5% 1.8% 14.8% (g liquid/g sorbent) Density Viscosity Temperature Liquid Used (g/cm 3 ) (cP) (° C.) Comments Light (Diesel) 0.829 3 20 Float Medium (crude oil) 0.944 290 20 Sorbent floats Heavy (crude/bunker) 0.995 2050 20 Floats, not fully saturated
[0091]
Adsorption - Long Test
Oil Viscosity
Pick-up ratio
Oil Type
(cP)
(g oil/g sorbent)
Diesel fuel
3
5.8
Medium oil
290
12.0
Heavy Oil
2050
13.2
[0092]
Long L Test - 15 minutes
Liquid #1
Liquid #2
Liquid #3
Sample
Sample
Sample
1
2
3
1
2
3
1
2
3
Temperature (° C.)
19
19
19
19
19
19
19
19
19
Sample weight (g)
5.14
5.34
5.29
5.76
5.58
7.24
7.42
7.62
6.30
Wet sample weight (g)
33.22
36.30
38.48
71.43
75.28
95.50
104.71
107.37
91.41
Initial Sorption Capacity
5.46
5.80
6.27
11.40
12.49
12.19
13.11
13.09
13.51
(g liquid/g sorbent
Average liquid up-take
5.8
12.0
13.2
(g liquid/g sorbent)
Standard Deviation
7.0%
4.7%
1.8%
(g liquid/g sorbent)
Density
Viscosity
Temperature
Liquid Used
(g/cm 3 )
(cP)
(° C.)
Comments
Light (Diesel)
0.829
3
20
Float
Medium (crude oil)
0.944
290
20
Float/sorbent out
mostly in one chunk
Heavy (crude/bunker)
0.995
2050
20
Float
CONCLUSIONS
[0093] The sorbent material was tested using ASTM F726-99 Protocol in order to evaluate its performance. It passed the buoyancy test by having less than 10% of the product sink under dynamic (wave) conditions.
[0094] The sorbent appeared to have reached saturation in all tests except the Short Test in Heavy Oil. This was confirmed by the results of the Long Test, which showed higher values (over 50% higher pick-up ratio when compared to Short Test). There was variability in the testing results which forced repeat testing to be undertaken. Due to the relatively fine particle size of the sorbent it is thought that losses through the test baskets contributed greatly to this variability.
[0095] The oil sorption capacities, expressed as weight ratios of liquid sorbed per unit weight of sorbent, varied between 5.2 and 10.7 for the standard 15 minute tests.
[0096] It will be evident that the composition according to the invention is uniquely able to be re-used thereby reducing the cost of processing materials, the cost of processing and disposal of waste, and the cost of transport and storage. Moreover the adsorbent composition presents a reduced risk to personnel because it is biodegradable and non-toxic.
[0097] The advantages of the process of the invention include, but are not limited to, the use of only non-toxic and biodegradable materials, the ability of the process to return uncontaminated oil, chemical, or other hydrocarbon to the original source of the spill or back to the refinery, and the re-usability of the composition according to the invention after separating it from the oil, chemical, or other hydrocarbon at the site of the spill.
[0098] It will be appreciated that the invention goes beyond the scope of the limited disclosure outlined herein above, and that nothing stated herein above should be taken to unnecessarily limit the scope of the invention claimed.
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This invention relates to improvements in products and processes for cleaning up oil, chemical, or other hydrocarbon spills, and cleaning up the environment where such spills have occurred. In one aspect of the invention, there is provided an adsorbent polymeric composition which is oleophilic and capable of adsorption of other chemicals and hydrocarbons from both land and water, the adsorbent composition including polyethylene/vinyl acetate copolymer, catalyst, cross-linking agent, lubricant, blowing agent and a bulking agent. In a second aspect of the invention there is provided a method of manufacture of an adsorbent composition for use in retrieving and recycling oil, chemicals and hydrocarbons from land or water environments.
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BACKGROUND OF THE INVENTION
One of the problems with the polystyrene reaction injection molding systems is shrinkage of the foam before polymerization completes to the degree necessary for the polymer to retain its shape. Commercially available surfactants such as polymethylphenylsiloxane and block copolymer styrene-dimethylsiloxane enable the foam to retain the mold's shape. However, these surfactants react with commonly used initiators requiring more initiator and reducing the product's molecular weight.
SUMMARY OF THE INVENTION
A novel class of block copolymer of styrene type monomer and vinyltrihydrocarbon substituted silane, with blowing agents, were found to solve both the reaction and the low molecular weight problems in reaction injection molding. Weight average molecular weights over 200,000 are easily obtained using the block copolymer.
DETAILED DESCRIPTION OF THE INVENTION
The new surfactants used with foaming agents are thought to be AB type block copolymers. A preferred method of manufacture is to polymerize the alkenyl aromatic monomer such as styrene then add the vinylorganosilane to at least one end of the alkenyl aromatic polymer such as styrene by polymerizing it on one end of the living alkenyl aromatic polymer.
(a) Polymers of the present invention having the formula: ##STR1## wherein Ar is selected from the group consisting of phenyl, alkyl substituted phenyl, napthyl alkyl substituted alkyl groups wherein the alkyl substitution contains from 1 to 20 carbon atoms;
R=alkyl radical containing 1-10 carbon atoms;
R 1 =Hydrogen or methyl;
R 2 , R 3 , R 4 are individually selected from the group consisting of alkyl and cycloalkyl groups varying from 1-10 carbon atoms, phenyl and alkyl or cyclo alkyl substituted phenyl;
m and n vary independently among the positive integers, preferably less than about 5,000 and more preferably m varies among the integers between 90 and 270 and n varies among the integers between 10 and 30;
T is the radical obtained from chain termination.
For producing Block B, vinyltriorganosilanes of the following structure are used: ##STR2## where R 2 , R 3 and R 4 represent identical or different radicals, for example, not by way of limitation: alkyl radicals of normal, branched or cyclic structure with one to sixteen carbon atoms, methyl, butyl, cyclohexyl aryl or substituted aryl or naphthenic radicals which include monomers such as vinylethyldimethylsilane, vinylbutyldi-methylsilane, vinyltrimethylsilane and vinylphenyl-dimethylsilane, as well as copolymers of said monomers and styrene or its derivatives can be used for producing Block B.
The block copolymers of type A-B are produced, according to the invention, by anionic block copolymerization of conjugated dienes and/or styrene and polyvinyltriorganosilanes in the presence of lithium-based initiators in an organic solvent.
Under the above conditions there are produced nonelastomeric or elastomeric high-molecular compounds of the following general structure: ##STR3##
The process of producing silicon-containing block copolymers of the type A-B can be carried out in the presence of the following anionic polymerization initiators: metallic lithium, lithium alkyls or other lithium organic compounds. The alkyls in said lithium alkyls are preferably branched, e.g. isopropyllithium, sec. butyllithium, isobutyllithium, isoamyllithium, etc.
Block copolymerization is carried out in hydrocarbon solvents: lower alkanes of normal and iso-structure containing from 5 to 10 carbon atoms, aromatic and cycloaromatic hydrocarbons or mixtures of the same, e.g. hexane, cyclohexane, benzene, toluene, or mixtures of the same, etc.
In the presence of metallic lithium or lithium-organic compounds in the above-mentioned hydrocarbon solvents there is obtained block A. Polymerization is carried out at temperatures from 0° to 70° C.
The concentration of the initiator can vary within a wide range, depending on the required molecular weight of the block copolymer, e.g., from 0.001 mol/l. to 0.1 mol/l.
Polymerization can be carried out in vacuum (from 10- 1 to 10- 5 mm. of mercury) or in an atmosphere of a dry and purified inert gas, e.g. nitrogen, argon, etc.
The block copolymer of the general formula A-B is produced by the consecutive addition of monomers.
The consecutive process of adding monomers is carried out as follows.
In the first stage there is produced in the presence of lithium alkyls and an organic solvent a block A polymer having a terminal lithium ion, a so-called living polymer. This stage is completed when the free initiator and monomer are completely exhausted. In the second stage there is added a vinyl silane which grows on the polymeric chains of block A, forming block B. Block B also has a lithium ion at the ends of the polymeric chains, and after completion of polymerization of the block copolymer, the polymer is terminated with an active hydrogen compound such as methanol, isopropanol and the like. The polymer solution may then be washed to remove water soluble residues and the polymer recovered by evaporation of the solvent.
Although there is no known reason to limit the extent of polymerization, most embodiments of the invention will have each block preferably comprised of less than about 5,000 monomer units of each. Desirable polymers of the AB configuration have a weight average molecular weight of about 10,000 to 30,000 grams per mole and a polysilane content of about 5 to about 10 percent.
There are no known limits on the amount of the surfactant used to assist foaming. While enough surfactant has to be used to be operable, there is no reason to use much more than necessary to achieve the foaming stabilization required. For some of the invention's embodiments, about 0.5 to 1.5 weight percent was the preferred concentration of the surfactant.
Use of Surfactant
The surfactant can be added to a mixture of the desired monomer or monomers, crosslinker, or other desired organic materials. This mixture can be saturated with an inert gas such as nitrogen. The new mixture is then initiated by an anionic initiator and foamed simultaneously by dropping the pressure,
The manufacture and use of the invention can also be carried out by numerous alternative methods such as by substituting a volatile fluid blowing agent foaming system for the saturated nitrogen foaming system.
The following examples demonstrate a few embodiments of the invention. All ratios are weight ratios unless otherwise indicated.
EXAMPLE 1
Styrene (5.0 g) which has been deoxygenated with nitrogen, was added to 100 ml of deoxygenated hexane. An initiator n-butyllithium (0.15 millimole) was added and the polymerization was allowed to continue for about thirty minutes. Trimethylvinylsilane (5.0 g) was then added. The polymerization was allowed to continue for several hours. Methanol was used to stop the reaction. The initiator residue was removed by water extraction. The solution was evaporated to leave a styrene-vinyltrimethylsilane diblock copolymer.
EXAMPLE 2
Example 1 is repeated with triethylvinylsilane. The product is a styrene-vinyltriethylsilane diblock copolymer.
EXAMPLE 3
A polystyrene/styrene syrup (80 weight percent styrene) (400 g) had styrene-vinyltrimethylsilane diblock copolymer (1.2 g) added. The resulting solution was stirred under a nitrogen atmosphere (100 psi) for about twenty minutes. n-Butyllithium (5.31 milliequivalents) in a hexane solution (3.0 ml) was then added and the solution was stirred 30 seconds. The solution was molded at atmospheric pressure. After curing for ninety minutes (65°-80° C.), the polymer was removed from the mold. The resulting foam had a density of about 0.7 g/cm 3 and fine cells.
EXAMPLE 4 (COMPARATIVE)
Example 3 was repeated without the styrene-vinyltrimethylsilane diblock copolymer. The resulting material had large holes and voids throughout the structure and exhibited considerable shrinkage.
EXAMPLE 5
Example 3 was repeated at a nitrogen pressure of 30 psi. The resulting material is a fine cell foam with a density of 0.82 g/cm 3 .
EXAMPLE 6
Example 3 was repeated at a nitrogen pressure of 200 psi. The resulting material is a fine cell foam with a density of 0.53 g/cm 3 .
EXAMPLE 7
A mixture of divinylbenzene (6.0 g), styrene (320 g), polystyrene (80 g), and styrene-vinyltrimethylsilane diblock copolymer (90 weight percent styrene) (1.2 g) was stirred for twenty minutes under nitrogen (100 psi). n-Butyllithium (5.31 milliequivalents) was added and the mixture was stirred for an additional thirty seconds. The mixture is molded in the atmosphere at atmospheric pressure. The mold is maintained at 100° C. for thirty minutes. The resulting very finely celled foam has a density of 0.64 g/cm 3 .
EXAMPLE 8
A block copolymer of polybutadiene and polystyrene (72/28 by weight) (80 g) was added to styrene (320 g). Styrene-vinyltrimethyl silane diblock copolymer (90 weight percent styrene) (1.2 g) was added to the styrene mixture. This solution was stirred for twenty minutes under nitrogen (100 psi). n-Butyllithium (14.16 milliequivalents) was added and the mixture was stirred for thirty seconds. Then the mixture was molded at atmospheric pressure. The molding was cured for ninety minutes (81° C.). The resulting fine cell foam was very flexible and had a density of 0.55 g/cm 3 .
EXAMPLE 9
Example 3 was repeated with a styrene-vinyltrimethylsilane diblock copolymer. The resulting fine cell foam had a density of 0.6 g/cm 3 .
EXAMPLE 10
The ratio of trimethylvinylsilane to styrene in the block copolymer of 2000 g/mole molecular weight of Example 1 was varied and was used as a surfactant for styrene/polystyrene (80/20 by weight) in 1 weight percent concentration. The solution was stirred under nitrogen (100 psi) for twenty minutes. The pressure was then released and the percent change in volume from the fully foamed state relative to the state when the foam has dissipated was calculated. The results are summarized in Table 1.
TABLE 1______________________________________Mole % Δ %Trimethylvinylsilane Volume______________________________________100 5080 5040 5035 4720 3010 5______________________________________
EXAMPLE 11
The molecular weight of a 10 mole fraction trimethylvinylsilane block copolymer prepared in the manner of Example 10 was varied and the percent change in volume is calculated as in Example 10. The results are summarized in Table 2.
TABLE 2______________________________________Molecular Weight Δ % Volume______________________________________35,000 4025,000 9020,000 92 8,000 100 3,500 7______________________________________
EXAMPLE 12
Example 3 was rerun and the nitrogen pressure was varied. The results are summarized in Table 3.
TABLE 3______________________________________ Nitrogen Pressure Density (psi) g/cm.sup.3______________________________________ 200 0.54 100 0.60 30 0.86______________________________________
EXAMPLE 13
Example 3 was rerun and the stirring time was varied. The results are summarized in Table 4.
TABLE 4______________________________________Stirring Time DensityMinutes g/cm.sup.3______________________________________20 0.5810 0.63 5 0.70 2 0.81______________________________________
EXAMPLE 14
A mixture was prepared employing 320 grams of styrene having dissolved therein 90 grams polystyrene, 0.2 gram of divinylbenzene, 20 grams of normal pentane and 1.5 grams of block copolymer of styrene and trimethylvinylsilane as hereinbefore described. The mixture was stirred under a nitrogen atmosphere at a pressure of 100 pounds per square inch for a period of 20 minutes. On completion of the 20 minutes stirring, 3 milliliters of 1.77 normal butyl lithium in hexane were added and stirring continued for a period of 30 seconds. The mixture was transferred to a mold at atmospheric pressure. The mold had a rectangular cavity measuring 15.2 centimeters by 19.7 centimeters by 35 centimeters. The mold and contents were then placed in an oven having a temperature of 100 degrees centigrade for a period of 30 minutes. At the end of that period, mold and contents were removed from the oven and the rectangular foam article removed from the mold. The article replicated the internal dimensions of the mold and had a uniform fine celled structure. The resultant molded article was then placed in a hot air oven having a temperature of 135° centigrade to cause further expansion of the article. The resultant foam was tough, impact resistant and had a density of 3.2 pounds per cubic foot.
A wide variety of expanding agents may be utilized in the practice of the present invention. Such foaming agents are volatile fluid materials such as methane, ethane, propane, butane, pentane, nitrogen, helium, argon and the like. The foaming agents useful in the present invention are those that become gaseous at polymerization temperature and are chemically inert to a polymerization initiator such as an organolithium compound, for example n-butyllithium.
As is apparent from the foregoing specification, the present invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. For this reason, it is to be fully understood that all of the foregoing is intended to be merely illustrative and is not to be construed or interpreted as being restrictive or otherwise limiting of the present invention, excepting as it is set forth and defined in the hereto-appended claims.
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A new class of hydrocarbon foaming agents which are block copolymers, one block of which is a styrene derivative, the other a vinylsilane derivative. Said hydrocarbon foaming agents are nonreactive with common anionic initiators.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This utility patent application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/081,075 filed Jul. 16, 2008, entitled “Composite Armor Structure,” the entire disclosure of the application being considered part of the disclosure of this application, and hereby incorporated by reference.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to armor used for preventing the penetration of structures by projectiles. More specifically, the invention relates to an improved armor including a fiber grid structure having composite tiles, such as composite ballistic resistance tiles retained in the grid with the grids forming a substantially polyhedron structure that both increases the resistance to penetration as well as increases the performance of each individual composite tile.
[0003] Armor systems have traditionally been known to include thick metal as an outer skin to protect the structure or vehicle. Typically, these armor structures such as those used in military vehicles include layers of thick metal plates to provide resistance to the penetration of projectiles. The resistance to penetration of projectiles is very important to protect individuals inside from injury and death. Newer types of armor piercing projectiles have decreased the efficiency of metal plates in preventing projectile penetration and metal armor systems are extremely heavy, which detracts from the performance and fuel economy of mobile vehicles. The heavy weight of metal-plated armor causes many problems including limited vehicle speed, high fuel consumption, increased time for vehicle assembly, as well as detracting from the maneuverability and other operational capabilities of the vehicle. To summarize, the weight of the layered metal plates causes serious reductions in performance capabilities of any vehicle to which the armor system is added. For example, increased fuel consumption due to the heavy weight of the metal plates requires more frequent fill-ups and reduces the range of the armored vehicle. In addition, increased fuel consumption creates other problems in a military environment, such as requiring more trips to the armored vehicles by fuel tanker trucks, which are typically not armored. These fuel tanker trucks during a military operation are common targets as the armored vehicles stop operating if fuel is unable to reach them, and therefore improving the fuel economy of armored vehicles is important. In addition, the additional weight of the vehicle from the armor, when used in a military environment may seriously reduce the operating performance and characteristics of the vehicle. For example, certain vehicles when armored are incapable of traveling across some off-road terrains.
[0004] To address some of the above deficiencies with metal-plated armor, some manufacturers have replaced metal armor with lighter weight armor systems made from composite material having reinforced fibers made of, for example, Kevlar, S-2 glass, graphite, or high molecular weight polyethylene. Such armor systems have utilized these multiple layers of composite materials to achieve reduced overall weight, while yet providing sufficient structural properties that preserve the ability of the armor to protect against penetration. Many times these composite armor materials are used in combination with metal plates and can provide additional protection while yet reducing weight. It is still desirable to reduce the weight of the vehicle while yet improving the resistance of the armor to projectile penetration. These systems are very expensive and generally do not provide the desired balance between weight, cost and effectiveness.
[0005] Other armor systems have been designed that use ceramic tiles in connection with a grid to provide protection against high speed projectiles while yet minimizing the weight of the armor system. Ceramic tiles are much lighter than metal plates. Many ceramic tiles have convex surfaces and are inserted into a honeycomb grid. Upon impact by the projectile against the ceramic tiles, ceramic armor systems are known to experience failure of not only the impacted plate but also of the plates adjacent to the plate receiving the impact. Therefore, it is critical but also difficult to manage the propagation of cracks from the plate receiving the impact to adjacent plates. Ceramic tiles also typically lose structural integrity after an initial impact, making the armor system vulnerable to subsequent impacts.
[0006] The armor system must sustain multiple hits by projectiles to sufficiently protect the occupants of a vehicle. As stated above, many ceramic systems provide excellent resistance to projectile penetration against the first impact but their effectiveness is typically substantially reduced for subsequent impacts. Some manufacturers have proposed layering on top of each other multiple layers of ceramic tiles similar to the layers of metal plates previously used as well as providing layers of composite materials in combination with the ceramic tiles. These layers of composite materials are generally sheets such as sheets of carbon fiber directly engaging the ceramic tiles. While these multiple layered ceramic tiles provide additional protection, they also substantially increase the weight of the vehicle while yet experiencing propagation of cracks and debris created during impact. Propagation of cracks weakens the adjacent composite plates as well as the underlying plates. The propagation of such cracks results from the tight engagement of the armor structure and therefore while multiple layers of ceramic tiles do provide additional protection, the armor system may after an initial impact be substantially weakened against subsequent impacts.
SUMMARY OF THE INVENTION
[0007] The present invention is directed to a composite armor that improves the resistance to penetration of projectiles as well as resistance to projectile penetration from multiple impacts, while reducing the weight of the armor structure as compared to metal plate systems and other armor systems with similar penetration resistance.
[0008] More specifically, the armor system of the present invention provides a polyhedron structure which covers the surface on which armor protection is needed. The polyhedron structure is made up of a plurality of cellular structures into which composite inserts are provided. Cellular structures generally are generally a one-piece integrally formed continuous composite cellular structure of which multiple cellular structures are used to create the polyhedron structure. A filler such as a ballistic foam is provided within the polyhedron structure formed by the cellular structures. If needed, various composite laminates may be provided to provide additional protection.
[0009] Further scope and applicability of the present invention will become apparent from the following detailed description, claims and drawings. However, it should be understood that the specific examples in the detailed description are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present invention will become more fully understood from the detailed description given here below, the appended claims, and the accompanying drawings in which:
[0011] FIG. 1 is a perspective view of a cellular structure;
[0012] FIG. 2 is a plan view of the cellular structure;
[0013] FIG. 3 is a perspective view of cellular structures forming the inter-disposed sides;
[0014] FIG. 4 is a plan view of a first exemplary side in FIG. 3 ;
[0015] FIG. 5 is a plan view of a second exemplary side in FIG. 3 ;
[0016] FIG. 6 is an exploded perspective view of an exemplary polyhedron structure;
[0017] FIG. 7 is an exploded perspective view of a second exemplary polyhedron structure;
[0018] FIG. 8 is an exploded perspective view of a third exemplary polyhedron structure;
[0019] FIG. 9 is an exploded perspective view of a fourth exemplary polyhedron structure;
[0020] FIG. 10 is an exploded perspective view of a fifth exemplary polyhedron structure;
[0021] FIG. 11 is an exploded perspective view of a cellular structure without composite inserts;
[0022] FIG. 12 is an exploded perspective view of a cellular structure partially assembled to form the polyhedron structure;
[0023] FIG. 13 is a perspective view of the grid polyhedron cellular structure;
[0024] FIG. 14 is a perspective view of the cellular structure with composite plates in place and forming the polyhedron structure;
[0025] FIG. 15 is a perspective view of the polyhedron structure as complete with a portion of the sides removed to show the various layers;
[0026] FIG. 16 is a perspective view of the polyhedron structure;
[0027] FIG. 17 is an exploded partial perspective view of an exemplary polyhedron structure;
[0028] FIG. 18 is an enlarged perspective view of the polyhedron structure showing the various layers of laminate;
[0029] FIG. 19 is a two-layer polyhedron structure showing the cellular structures without composite inserts and with the sides exploded off to show the inner portions;
[0030] FIG. 20 is a perspective view of an assembled two-layer cellular structure;
[0031] FIG. 21 is a perspective view of the polyhedron structure with portions removed to show the inner foam;
[0032] FIG. 22 is a perspective view of the cellular structure with inserted ceramic tiles forming the polyhedron structure;
[0033] FIG. 23 is a perspective view of a completed polyhedron structure;
[0034] FIG. 24 is an exemplary side view of a two-layer polyhedron structure;
[0035] FIG. 25 is a side view of the two-layer polyhedron structure in FIG. 24 with ceramic tiles partially in place and partially removed;
[0036] FIG. 26 is a perspective view of a three-layer polyhedron structure showing the grid of the cellular structures;
[0037] FIG. 27 is a perspective view of the polyhedron structure with ceramic tiles in place;
[0038] FIG. 28 is a perspective view of the polyhedron structure;
[0039] FIG. 29 is a side view of the polyhedron structure in FIG. 27 with ceramic tiles partially in place and partially removed;
[0040] FIG. 30 is another exemplary side view of the polyhedron structure in FIG. 27 with the ceramic tiles partially in place and partially removed;
[0041] FIG. 31 is a perspective view of a four-layer polyhedron structure showing the grid of the cellular structure;
[0042] FIG. 32 is a first exemplary side view of a four-layer polyhedron structure;
[0043] FIG. 33 is a second exemplary side view of a four-layer polyhedron structure;
[0044] FIG. 34 is a perspective view of an exemplary two-layer polyhedron structure using rectangular side plates;
[0045] FIG. 35 is a perspective view of the polyhedron structure in FIG. 38 with the ceramic tiles inserted;
[0046] FIG. 36 is a completed perspective view of the polyhedron structure in FIGS. 34 and 35 ;
[0047] FIG. 37 is a perspective and top plan view of a hexagonal grid element;
[0048] FIG. 38 is a perspective and top plan view of a triangular grid element;
[0049] FIG. 39 is a perspective and top plan view of a trapezoidal grid element;
[0050] FIG. 40 is an exemplary illustration of an armored vehicle;
[0051] FIG. 41 is a perspective view of a two-layer cellular structure wherein the grids are offset relative to each other;
[0052] FIG. 42 is a top plan view of a two-layer cellular structure wherein the grids are offset relative each other; and
[0053] FIG. 43 is a side view of a two-layer cellular structure wherein the grids are offset relative to each other.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0054] The present invention is directed to an armor system 10 such as for the exemplary vehicle 110 illustrated in FIG. 40 . The armor system 10 is partially illustrated in FIGS. 1-39 as being formed from individual polyhedron structures 20 . The individual polyhedron structures 20 are generally illustrated in greater detail in FIGS. 1-39 and multiple structures of varying sizes may be required to sufficiently armor a vehicle. More specifically, the multiple polyhedron structures 20 creates individual cells that combine to form the armor system 10 . Therefore, for the exemplary vehicle 110 illustrated in FIG. 40 , the polyhedron structures 20 would preferably substantially cover the vehicle. To conform the armor system 10 to the vehicle, the structure of the individual polyhedron cells 20 may vary to match the contour of the vehicle. However, to reduce manufacturing costs, it is preferable to use standardized polyhedron structures whenever possible, which can be formed in single or multiple sizes to form the armor system. Therefore, the armor system 10 will be described below as being formed of multiple polyhedron structures 20 , even though other shapes may be used having a cavity that is filled with a filler 100 , such as ballistic foam.
[0055] The polyhedron structures 20 are generally formed of a grid of cellular structures 22 . The individual cellular structures 22 may combine to form a cellular structure 30 that forms the outer surface to which laminates 80 are applied. As more specifically illustrated in FIG. 6 , the cellular structure may be formed from a first face 32 , a second face 34 and inter-disposed cellular sides 50 . As further illustrated in FIG. 19 , the cellular structure 30 may further include at least one cellular structure 40 . These at least six cellular structures 22 , forming the outer cellular structure 30 specifically the two faces 32 , 34 and four sides 50 , form a cavity into which the filler 100 is placed. The cellular structures 22 forming the outer cellular structure 30 as well as any secondary or inner cellular structures 40 or side cellular structures 50 each include a grid 38 that defines openings 36 . The openings 36 are configured to receive composite inserts 70 . The grid 38 extends to a border structure 39 . Due to the overall size of the cellular structures 22 , the grid 38 may have partial openings 37 near the border 39 . These partial openings may be filled with different shaped or partial composite inserts 70 .
[0056] It is preferable for the strength and integrity of the cellular structure 30 that the grid structure 38 of the sides 50 meets the grid structure 38 , of the cellular faces 32 , 34 structure, and if present any additional inner cellular structures 40 . More specifically, the points where the grid structure 38 meets the border 39 are approximately aligned for all of the cellular structures 22 . This allows the composite inserts 70 to individually support an adjacent plate and minimizes the potential for propagation of cracks from an insert 70 on the cellular structure faces 32 , 34 to an insert 70 or in particular multiple inserts on the sides 50 . As illustrated in the side views of other Figures, the sides within a single cellular side structure may differ, such that they match the edge pattern of one of the exterior cellular structure faces 32 , 34 .
[0057] Composite inserts 70 generally include a perimeter portion 72 and a first side 74 and a second side 76 . Composite inserts 70 are inserted into the cellular structures 22 and in particular, into the openings 36 defined by the grid structure 38 . The composite inserts 70 may be formed in triangle shapes 60 , partial hexagon shapes 62 , hexagon shapes 42 , rectangular or square shapes 64 or any other desired shapes.
[0058] The armor system 10 further includes laminates 80 which are secured to the cellular structures 22 and the composite inserts 70 . The laminates 80 are generally secured to the cellular structure 30 as well as the inner cellular structures 40 but in the preferred embodiment are not secured to the inter-disposed sides 50 . While laminates 80 secured to the inter-disposed sides 50 would improve protection against projectile penetration, the laminates 80 are generally expensive and would not provide a substantial increase in protection. The laminates 80 are generally secured with the use of a binding material such as a resin to the cellular structures 22 . The bonding material may also be used as a filler applied to the inserts 70 and in some cases around the perimeter portion 72 to fill in the gaps between the inserts 70 and the grid structures 38 . The binder may also bind the sides 50 to the other cellular structures 30 and 40 .
[0059] Laminates 80 can be formed from any material that improves the penetration resistance of the armor and more particularly, improves the resistance of the composite inserts 70 against penetration. The laminates 80 are generally shown in the Figures as being placed on at least one side of the cellular structures 22 forming the polyhedron structures in particular the exterior surfaces however, as seen in other Figures, the laminates 80 may be layered on each side of the cellular structures 22 or selectively layered to maximize resistance to penetration balanced against cost. In general, the armor 10 illustrated in the Figures uses at least two layers of laminates 80 in particularly a first layer 82 formed of a carbon fiber reinforced polymer which generally forms the exterior surface of the polyhedron structure 20 and a second layer 84 of a hybrid ductile fabric which generally engages directly against the composite inserts 70 . In some cases, the binder although not illustrated may be inter-disposed between the second laminate layer 84 and the composite inserts 70 . In the preferred embodiment, the exterior surface of the polyhedron structure on at least one side includes four layers of laminates particularly the first and second layers 82 and 84 layered in an alternating manner specifically including extending away from the cellular structure 22 , the hybrid ductile fabric lamina 84 , high modulus lamina 82 , hybrid ductile fabric 84 , and high modulus lamina or carbon reinforced polymer 82 . In the preferred embodiment, it has been found that materials having acoustic impedance between 0.7×10 6 and 40×10 6 kg/m 2 , as measured in a direction parallel to the normal of the laminates sheets are most effective. It should be appreciated and as disclosed in the Figures, various configurations and placements of laminates 80 may be used with the armor system 10 . Adding the laminates 80 generally improves the strength against projectile resistance. Also, though not illustrated, the cellular structures 22 may form a polyhedron structure 20 with each cellular structure 22 having composite inserts being directly laminated together or laminated together with the laminates 80 inter-disposed between.
[0060] As further illustrated in the Figures specifically FIGS. 19-36 , the polyhedron structures 20 may be stacked to create two, three or more layers with filler between. It is expected as shown in the Figures that for the stacked polyhedron structures 20 that only one cellular structure 40 would be placed between each filler 100 to reduce costs, although individual polyhedron structures 20 that form by itself one layer of armor may be stacked such that the cellular structures 22 with composite inserts 70 inserted in close proximity with no filler therebewteen. The sides 50 may be formed from multiple sides in stacked configuration as illustrated in the Figures, or one side cellular structure (not illustrated), extending past the inner cellular structure 40 .
[0061] The composite inserts 70 may be made of materials such as ceramic, glass, metal matrix, ceramic matrix composite, or any other types of composite materials known to provide high resistance to impact penetration while providing low weight, particularly when compared to metal armor systems. The surfaces of the composite inserts 70 may vary such as having convex or concave surfaces. In addition to the other shapes described above, the composite inserts 70 may be provided in square, oval, round, or other shapes.
[0062] The cellular structures 22 may be formed in a variety of configurations but preferably use the cellular structures as described in U.S. patent application Ser. No. 11/504,343 filed on Aug. 15, 2006. Such cellular structures minimize crack propagation from a projectile impact. As described in U.S. application Ser. No. 11/504,343, the cellular structures may be formed from individual fibers that extend approximately continuous throughout the cellular structure. Of course, other fiber structures may be used without continuously extending fibers.
[0063] The filler within the polyhedron structure 20 is generally illustrated as 100 and is typically a ballistic foam or another type of lightweight filler material that is resistant to projectile penetration. The filler 100 also helps to support the composite inserts after impact from a projectile such that the initial impact of a projectile, even if it cracks the outer layer of composite inserts near the impact zone, does not completely or substantially reduce subsequent performance to additional impacts. By separating the composite inserts 70 on the cellular structure 30 with the filler 100 from the second layer of ceramic inserts shown as being inserted in the grid 40 , the armor system 10 may withstand subsequent impacts from projectiles without being compromised. In addition, using a filler 100 such as a ballistic foam further increases the ability of the armor system 10 to withstand against subsequent projectile impacts.
[0064] The cellular grid structures 22 in particular the cellular structures 30 , 40 and 50 of are generally also assembled as described in U.S. patent application Ser. No. 11/504,343 filed on Aug. 15, 2006. Once the individual cellular structures 22 are assembled, the polyhedron structure 20 is then assembled out of the cellular structure 30 , second cellular structure 40 as well as the inter-disposed sides 50 . After it is assembled into a polyhedron structure, the filler or ballistic foam 100 is inserted into the cavity of the polyhedron structure 20 . In some embodiments, the polyhedron structure 20 may be assembled except one side 50 or one of the outer cellular structures 30 or 40 , to allow for easy insertion of the filler 100 . In other embodiments, the cellular structures 22 may be assembled but for at least one composite insert which is inserted later. To assembly multi-layer polyhedron structures, the cellular structures 22 are assembled as described in U.S. patent application Ser. No. 11/504,343 and then assembled into the polyhedron structure 20 . Once the ballistic foam or filler 100 is inserted into the polyhedron structure 20 , the polyhedron structure easily maintains its shape for assembly onto the armor system of a vehicle 110 . The polyhedron structure 20 may be a cuboid, a rectangular box, a hexahedron, an octagonal prism, an elongated pentagonal cupola as well as any other desirable shape. As illustrated in FIG. 40 , it is assembled on the vehicle 110 , the cellular structure 102 having composite inserts 104 is shown in use for the floor plan 107 of a military vehicle 109 . It should be appreciated that the cellular structure 102 can be assembled adjacent to each other and throughout the entire floor plan or across the entire outer surface of the vehicle. The illustrated vehicle and shape is only an exemplary embodiment and it may be used on a variety of other vehicles as well as stationary objects such as buildings and bunkers. Forming large polyhedron structures allows for lightweight building blocks to be created from which buildings may be quickly assembled for use in field operations where danger exists from projectiles. Therefore, the polyhedron structures can be transported as lightweight, easily assembled building blocks that quickly create an armored bunker structure for forward field operations. The structure would provide resistance against impact such as from mortar rounds, small arms fire, rocket propelled grenades and other projectiles. Of course, modifications can be made to the polyhedron structure 20 in particular the cellular structures 22 to provide attachment means to quickly connect the polyhedron structures together in a desired building shape.
[0065] As illustrated in FIGS. 41-43 , the cellular structures 22 may be place din an offset grid 38 pattern. More specifically, when the cellular structures forming one portion of the overall cellular structure 30 , may be placed together and have the grids offset, such that the grid of one structure 22 does not align with the grid of other cellular structures. Therefore, a projectile that hits the grid 38 of the outermost cellular structure, the weakest portion of the cellular structure will most likely hit a ceramic tile 70 of the underlying structure and not the grid of the underlying cellular structure. Of course, although the cellular structures are illustrated as being laminated or adjoining, ballistic foam 100 or other laminates may reside therebetween to provide enhanced resistance to projectile penetration.
[0066] The foregoing discussion discloses and describes an exemplary embodiment of the present invention. One skilled in the art will readily recognize from such discussion, and from the accompanying drawings and claims that various changes, modifications and variations can be made therein without departing from the true spirit and fair scope of the invention as defined by the following claims.
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A non-metallic armor structure having lightweight and being capable of withstanding multiple impacts without substantial degradation of the penetration resistance of the armor.
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TECHNICAL FIELD OF THE INVENTION
[0001] This present invention provides cDNA sequences and polypeptides having the enzyme CDP-diacylglycerol synthase (CDS) activity. CDS is also known as CTP:phosphatidate cytidyltransferase (EC2.7.7.41). The present invention further provides for isolation and production of polypeptides involved in phosphatidic acid metabolism and signaling in mammalian cells, in particular, the production of purified forms of CDS.
BACKGROUND OF THE INVENTION
[0002] CDP-diacylglycerol (DAG) is an important branch point intermediate just downstream of phosphatidic acid (PA) in the pathways for biosynthesis of glycerophosphate-based phospholipids (Kent, Anal. Rev. Biochem. 64: 315-343, 1995). In eukaryotic cells, PA, the precursor molecule for all glycerophospholipid, is converted either to CDP-DAG by CDP-DAG synthase (CDS) or to DAG by a phosphohydrolase. In mammalian cells, CDP-DAG is the precursor to phosphatidylinositol (PI), phosphatidylglycerol (PG), and cardiolipin (CL). Diacylglycerol is the precursor to triacylglycerol, phosphatidylethanolamine, and phosphatidylcholine in eukaryotic cells. Therefore, the partitioning of phosphatidic acid between CDP-diacylglycerol and diacylglycerol must be an important regulatory point in eukaryotic phospholipid metabolism (Shen et al., J. Biol. Chem. 271:789-795, 1996). In eukaryotic cells, CDP-diacylglycerol is required in the mitochondria for phosphatidylglycerol and cardiolipin synthesis and in the endoplasmic reticulum and possibly other organelles for the synthesis of phosphatidylinositol (PI). PI, in turn, is the precursor for the synthesis of a series of lipid second messengers, such as phosphatidylinositol-4,5-bisphosphate (PIP 2 ), DAG and inositol-1,4,5-trisphosphate (IP 3 ). Specifically, PIP 2 is the substrate for phospholipase C that is activated in response to a wide variety of extracellular stimuli, leading to the generation of two lipid second messengers; namely, DAG for the activation of protein kinase C and IP 3 for the release of Ca ++ from internal stores (Dowhan, Anal. Rev. Biochem. 66: 199-232, 1997).
[0003] The genes coding for CDS have been identified in E. coli (Icho et al, J. Biol. Chem. 260:12078-12083, 1985), in yeast (Shen et al., J. Biol. Chem. 271:789-795, 1996), and in Drosophila (Wu et al., Nature 373:216-222, 1995). A human cDNA coding for CDS (hCDS1) is described by us herein and has been reported in Weeks et al., DNA Cell Biol. 16: 281-289, 1997. Moreover, Heacock et al., J. Neurochem. 67: 2200-2203, 1997 report cloning of a CDS1 from a human neuronal cell line. Furthermore, Lykidis et al., J. Biol. Chem 272:33402-33409 ,1997 and Halford et al., Genomics 54:140-144, 1998 both report DNA sequences suspected to encode a human cds2 protein, but these references fail to disclose either biological activity or an intact N-terminal region for the putative proteins.
[0004] It is of interest to isolate polynucleotides coding for human CDS and express them in mammalian cells to determine the potential roles of this enzyme in cellular function and use this enzyme as a target for the development of specific compounds that are modulators of its activity. With the advance in the understanding of disease processes, it has been found that many diseases result from the malfunction of intracellular signaling. This recognition has led to research and development of therapies based on the interception of signaling pathways in diseases (Levitzki, Curr. Opin. Cell Biol. 8:239-244, 1996). Compounds that modulate CDS activity, and hence modulate generation of a variety of lipid second messengers and signals involved in cell activation, are therefore of therapeutic interest generally, and of particular interest in the areas of inflammation and oncology.
SUMMARY OF THE INVENTION
[0005] The present invention provides cDNA sequences, polypeptide sequences, and transformed cells for producing isolated recombinant mammalian CDS. The present invention provides two novel human polypeptides and fragment thereof, having CDS activity. The polypeptides discovered herein are novel and will be called hCDS1 (human CDS1) and hCDS2 (human CDS2). CDS catalyzes the conversion of phosphatidic acid (PA) to CDP-diacylglycerol (CDP-DAG), which in turn is the precursor to phosphatidylinositol (PI), phosphatidylglycerol (PG) and cardiolipin (CL).
[0006] The present invention further provides nucleic acid sequences coding for expression of the novel CDS polypeptides and active fragments thereof The invention further provides purified CDS mRNAs and antisense oligonucleotides for modulation of expression of the genes coding for CDS polypeptides. Assays for screening test compounds for their ability to modulate CDS activity are also provided.
[0007] Recombinant CDS is useful for screening candidate drug compounds that modulate CDS activity, particularly those compounds that activate or inhibit CDS activity. The present invention provides cDNA sequences encoding a polypeptide having CDS activity and comprising the DNA sequence set forth in SEQ ID NO. 1 (hCDS1), the DNA sequence set forth in FIG. 8 (hCDS2), shortened fragments thereof, or additional cDNA sequences which due to the degeneracy of the genetic code encode a polypeptide of SEQ ID NO. 2 (hCDS1), a polypeptide of FIG. 8 (hCDS2), or biologically active fragments thereof, or a sequence hybridizing thereto under high stringency conditions. The present invention further provides a polypeptide having CDS activity and comprising the amino acid sequence of SEQ ID NO. 2 (hCDS1), the amino acid sequence of FIG. 8 (hCDS2), or biologically active fragments thereof.
[0008] Also provided by the present invention are vectors containing a DNA sequence encoding a mammalian CDS enzyme in operative association with an expression control sequence. Host cells, transformed with such vectors for use in producing recombinant CDS are also provided with the present invention. The inventive vectors and transformed cells are employed in a process for producing recombinant mammalian CDS. In this process, a cell line transformed with a cDNA sequence encoding a CDS enzyme in operative association with an expression control sequence, is cultured. The claimed process may employ a number of known cells as host cells for expression of the CDS polypeptide, including, for example, mammalian cells, yeast cells, insect cells and bacterial cells.
[0009] Another aspect of this invention provides a method for identifying a pharmaceutically-active compound by determining if a selected compound modulates the activity of CDS for converting PA to CDP-DAG. A compound having such activity is capable of modulating signaling kinase pathways and being a pharmaceutical compound useful for augmenting trilineage hematopoiesis after cytoreductive therapy and for anti-inflammatory activity in inhibiting the inflammatory cascade following hypoxia and reoxygenation injury (e.g., sepsis, trauma, ARDS, etc.).
[0010] The present invention further provides a transformed cell that expresses active mammalian CDS and further comprises a means for determining if a drug candidate compound is therapeutically active by modulating recombinant CDS activity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] [0011]FIG. 1 shows the cDNA sequence encoding hCDS1. The nucleotide sequence analysis and restriction mapping of the cDNA clone revealed a 5′-untranslated region of 149 base pairs, an open reading frame capable of encoding a 461 amino acid polypeptide that spans nucleotide positions 150 to 1535 and a 3′-untranslated region of 520 base pairs.
[0012] [0012]FIG. 2 shows the translated amino acid sequence of hCDS1.
[0013] [0013]FIG. 3 shows the amino acid sequence of hCDS1.
[0014] [0014]FIG. 4 shows the sequence homology among the hCDS1 coding sequence, the yeast CDS coding sequence, E. coli CDS coding sequence, and the Drosophila CDS coding sequence. This comparison shows that hCDS1 has the greatest extended homology with amino acids 109 to 448 of Drosophila CDS. The hCDS1 protein and the CDS protein from Drosophila, yeast, and E. coli have 45%, 21% and 7% overall match in amino acid sequence, respectively.
[0015] [0015]FIG. 5 shows the results of in vitro hCDS1 activity assays on cell fractions from stable transfectants of NCI-H460 cells. CDS activity was assessed by conversion of (α- 32 P)CTP to ( 32 P)CDP-DAG in in vitro reactions that required addition of an exogenous PA substrate. This is a representative histogram comparing the radiolabel incorporated into various cell fractions (membranes, cytosol, and nuclei/unbroken cells) from NCI-H460 cells stably transfected with the hCDS1 cDNA (pCE2.hCDS) or vector only (pCE2). In all fractions, the hCDS1 cDNA increased radiolabel in the organic phase of the reactions. Total CDS activity was much greater in membrane fractions, as would be expected for membrane associated CDS, compared to cytosol fractions. Activity in unbroken cells masked the activity specific to nuclei.
[0016] [0016]FIG. 6 is a representative phosphorimage of [ 32 P]phospholipids from membrane fraction CDS assay reactions after the second dimension of ffTLC. FIG. 6 confirms that the radiolabeled product found in the membrane fractions does migrate with a CDP-DAG standard on TLC. The identities of labeled bands were determined by migration of phospholipid standards visualized by UV or FL imaging on the STORM after primulin staining. Lanes 1-3 represent triplicate samples derived from membranes of NCI-H460 cells transfected with the hCDS1 expression vector, and lanes 4-6 represent triplicate samples from transfectants with the control vector. Cells transfected with the hCDS1 cDNA showed 1.6-2.4 fold more CDS activity in membrane fractions than vector transfectants. The relative CDS activity between hCDS1 transfectants and vector transfectants was similar when determined by scintillation counting or TLC analysis. These data indicate that the hCDS1 cDNA clone of SEQ ID NO. 1 does encode CDS activity.
[0017] [0017]FIGS. 7A and 7B show, respectively, that production of TNF-α (tumor necrosis factor alpha) and IL-6 in ECV304 cells stably transfected with a hCDS1 expression vector increases by greater than five fold relative to ECV304 cells stably transfected with control vector after equal stimulation with IL-1β (interleukin-1 beta). There was little effect on basal level of cytokine release. These data indicate that overexpression of hCDS1 amplified the cytokine signaling response in these cells, as opposed to enhancing steady state, basal signals.
[0018] [0018]FIG. 8 shows the DNA and amino acid sequence of hCDS2.
[0019] [0019]FIG. 9 shows an amino acid sequence alignment of the hCDS2 coding sequence with the hCDS1 coding sequence. The amino acids that are identical between the two sequences are highlighted.
[0020] [0020]FIG. 10 shows the results of a TLS analysis of hCDS2 production of [32P]CDP-DAG after TLC analysis
[0021] [0021]FIG. 11 shows expression of hCDS1 and hCDS2 mRNAs in cancer versus normal prostate tissues.
DETAILED DESCRIPTION OF THE INVENTION
[0022] The present invention provides novel, isolated, biologically active mammalian CDS enzymes. The term “isolated” means any CDS polypeptide of the present invention, or any other gene encoding CDS polypeptide, which is essentially free of other polypeptides or genes, respectively, or of other contaminants with which the CDS polypeptide or gene might normally be found in nature.
[0023] The invention includes a biologically active polypeptide, CDS, and biologically active fragments thereof. As used herein, the term “biologically active polypeptide” refers to a polypeptide which possesses a biological function or activity which is identified through a biological assay, preferably cell-based, and which results in the formation of CDS-DAG species from PA. A “biologically active polynucleotide” denotes a polynucleotide which encodes a biologically active polypeptide. The term “biologically active fragment,” as used herein, refers to a nucleotide or polypeptide sequence in which one or more amino acids or nucleotides has been deleted but which retains CDS activity.
[0024] Minor modification of the CDS primary amino acid sequence may result in proteins which have substantially equivalent activity as compared to the sequenced CDS polypeptide described herein. Such modifications may be deliberate, as by site-directed mutagenesis, or may be spontaneous. All of the polypeptides produced by these modifications are included herein as long as the activity of CDS is present. This can lead to the development of a smaller active molecule which would have broader utility. For example, the present invention includes removal of one or more amino, carboxy terminal, or internal amino acids from the CDS polypeptide, so long as such amino acids are not required for CDS activity.
[0025] The CDS polypeptide of the present invention also includes conservative variations of the polypeptide sequence. The term “conservative variation” denotes the replacement of an amino acid residue by another, biologically active similar residue. Examples of conservative variations include the substitution of one hydrophobic residue, such as isoleucine, valine, leucine or methionine for another, or the substitution of one polar residue for another, such as the substitution of arginine for lysine, glutamic for aspartic acids, or glutamine for asparagine, and the like. The term “conservative variation” also includes the use of a substituted amino acid in place of parent amino acid provided that antibodies raised to the substituted polypeptide also immunologically react with the unsubstituted polypeptide.
[0026] The present invention further includes allelic variations (naturally-occurring base changes in the species population which may or may not result in an amino acid change) of the DNA sequences herein encoding active CDS polypeptides and active fragments thereof.
[0027] The inventive DNA sequences further comprise those sequences which hybridize under high stringency conditions (see, for example, Maniatis et al, Molecular Cloning (A Laboratory Manual), Cold Spring Harbor Laboratory, pages 387-389, 1982) to the coding region of hCDS1 (e.g., nucleotide #150 to nucleotide #1535 in SEQ ID NO. 1) or the coding region of hCDS2 (FIG. 8) and which have CDS activity. High stringency conditions include 5× SSC at 65° C., followed by washing in 0.1× SSC at 65° C. for thirty minutes or, alternatively, 50% formamide, 5× SSC at 42° C.
[0028] The present invention also includes nucleotide sequences having at least an 85%, at least a 90%, or at least a 95% sequence identity to the nucleotide sequence of the coding region of hCDS2 (FIG. 8) and which have CDS activity. The present invention further includes a polypeptide having at least an 85%, at least a 90%, or at least a 95% sequence identity to the hCDS2 polypeptide shown in FIG. 8 and which have CDS activity. As used herein, the term “sequence identity” denotes the “match percentage” calculated by the DNASIS computer program (Version 2.5 for Windows; available from Hitachi Software Engineering Co., Ltd., South San Francisco, Calif.) using standard defaults as described in the reference manual accompanying the software, which is incorporated herein by reference.
[0029] With regard to the above-described fragments of hCDS2, sequences that hybridize to hCDS2, and sequences having sequence identity to hCDS2, the invention includes embodiments where these sequences have an intact CDS N-terminal region.
[0030] The present invention further includes DNA sequences which code for CDS polypeptides having CDS activity but differ in codon sequence due to degeneracy of the genetic code. Variations in the DNA sequences which are caused by point mutations or by induced modifications of the sequence of SEQ ID NO. 1 or FIG. 8, which enhance the activity of the encoded polypeptide or production of the encoded CDS polypeptide are also encompassed by the present invention.
[0031] CDS Sequence Discovery
[0032] hCDS1
[0033] A homology search of the Genbank database (Boguski, et al., Science 265:1993-1994, 1994) of expressed sequence tags (dbEST) using Drosophila CDS protein sequence as a probe came up with several short stretches of cDNA sequence with homology to the Drosophila CDS protein sequence. These cDNA sequences were derived from single-run partial sequencing of random human cDNA clones carried out mainly by I.M.A.G.E. Consortium [LLNL] cDNA clones program. An example of the amino acid sequence homology between the Drosophila CDS and a human cDNA clone (IMAGE Clone ID #135630) is shown below:
371 KRAFKIKDFGDMIPGHGGIMDRFDCQFLMATFVNVYIS 408 KRAFKIKDF + IPGHGGIMDRFDCQ+LMATFV+VYI+ 11 KRAFKIKDFANTIPGHGGIMDRFDCQYLMATFVHVYIT 124
[0034] The top line (SEQ ID NO. 3) refers to the Drosophila CDS sequence from amino acids 371 to 408 and the bottom line (SEQ ID NO. 4) refers to a homologous region from IMAGE Clone ID #135630 translated using reading frame +2. Identical amino acids between these two sequences are shown on the middle line with the “+” signs indicating conservative amino acid changes. In order to determine if such cDNA clones with this level of homology to the Drosophila CDS sequence encoded human CDS sequence, it was necessary to isolate the full-length cDNA clone, insert it into an expression vector, and test if cells transfected with the cDNA expression vector will produce more CDS activity.
[0035] Accordingly, a synthetic oligonucleotide (o.h.cds.1R), 5′- CCCACCATGG CCAGGAATGG TATTTGC-3′ (SEQ ID NO. 5), was made based on the complement sequence of the amino acid region, ANTIPGHGG, of IMAGE Clone ID #135630 for the isolation of a putative human cDNA clone from a SuperScript human leukocyte cDNA library (Life Technologies, Gaithersburg, Md.) using the GeneTrapper cDNA positive selection system (Life Technologies, Gaithersburg, Md.). The colonies obtained from positive selection were screened with a [γ- 32 P]-ATP labeled synthetic oligonucleotide (o.h.cds.1), 5′-AGTGATGTGA ATTCCTTCGT GACAG-3′ (SEQ ID NO. 6), corresponding to nucleotides 144-168 of IMAGE Clone ID #133825. Of the few cDNA clones that hybridized with the o.h.cds.1 probe, clone LK64 contained the largest cDNA insert with a size of 1700 base pairs. DNA sequence analysis of LK64 showed the translated sequence of its largest open reading frame from the 5′ end contained extensive homology with amino acids 109 to 448 of the Drosophila CDS protein sequence. Clone LK64 did not appear to contain a full-length cDNA insert for CDS. It was missing the coding region corresponding to the first 110 amino acids from the N-terminus. A second homology search of the Genbank database (Boguski, et al., Science 265:1993-1994, 1994) using the 3′-untranslated sequence of LK64 as a probe came up with more short stretches of cDNA sequences with perfect homology to the 3′ end of the putative human CDS clone LK64. Restriction mapping and DNA sequence analysis of IMAGE Clone ID #145253 (Genome Systems, St. Louis, Mo.), derived from a placental cDNA library, showed it contained extensive sequence homology with the N-terminal coding region of the Drosophila CDS and overlapped with the sequence obtained from clone LK64.
[0036] To assemble the putative full-length human CDS cDNA clone, a 500 base pair Pst I-Nco I fragment from of IMAGE Clone ID #145253 and a 1500 base pair Nco I -Not I fragment from LK64 were isolated. These two fragments were inserted into a Pst I and Not I digested vector pBluescriptII SK(−) vector via a three-part ligation to generate pSK.hcds.
[0037] [0037]FIG. 1 shows the cDNA sequence of hCDS1. The nucleotide sequence analysis and restriction mapping of the cDNA clone revealed a 5′-untranslated region of 149 base pairs, an open reading frame encoding a 461 amino acids polypeptide that spans nucleotide positions 150 to 1535 and a 3′-untranslated region of 520 base pairs (FIG. 2). The ATG initiation site for translation was identified at nucleotide positions 150-152 and fulfilled the requirement for an adequate initiation site. (Kozak, Critical Rev. Biochem. Mol. Biol. 27:385-402, 1992). There was another upstream ATG at positions 4-6 but it was followed by an in-phase stop codon at positions 19-20. The calculated molecular weight of hCDS1 is 53,226 daltons with a predicted pI of 7.57.
[0038] The sequence of the 461 amino acid open reading frame (FIG. 3) was used as the query sequence to search for homologous sequences in protein databases. A search of Genbank Release 92 from the National Center for Biotechnology Information (NCBI) using the BLAST program showed that this protein was most homologous to the Drosophila CDS, the yeast CDS, and the E. coli CDS. FIG. 4 shows amino acid sequence alignment of this putative human CDS coding sequence with the Drosophila CDS, the yeast CDS, and the E. coli coding sequences, showing that the human CDS is most homologous to the Drosophila CDS.
[0039] hCDS2
[0040] A homology search of the Genbank database (Boguski, et al., Science 265:1993-1994, 1994) of expressed sequence tags (dbEST) using the hCDS1 protein sequence (Weeks et al, DNA Cell Biol. 16: 281-289, 1997) as probe came up with several short stretches of human cDNA sequences that were homologous but distinct from the hCDS1 sequence. These cDNA sequences were derived from single-run partial sequencing of random human cDNA clones projects carried out mainly by I.M.A.G.E. Consortium [LLNL] cDNA clones program.
[0041] Of these sequences, IMAGE Clone ID#485825 was found to have the following homology to the coding region of hCDS1 from amino acids 227-271:
10 20 30 40 QSHLVIHNLFEGMIWFIVPISCVICNDIMAYMFGFFFGRTPLIKL X:::::.:::::::::.::::.:::::: ::.::::::::::::: QSHLVTQNLFEGMIWFLVPISSVICNDITAYLFGFFFGRTPLIKL 230 240 250 260 270
[0042] The top line refers to IMAGE Clone ID#485825 translated using reading frame +3 and the bottom line refers to the coding region of hCDS1 from amino acids 227-271. Identical amino acids between these two sequences are shown on the middle line as “:” and with the “.” signs indicating conservative amino acid changes. Since the 5′-end of the cDNA insert of IMAGE Clone ID#485825 corresponded to amino acid 227 of hCDS1, this clone therefore does not appear to contain a full-length cDNA insert for CDS, most likely missing the coding region corresponding to the first 220 amino acids from the N-terminus. A second homology search of the Genbank database (Boguski, et al., Science 265:1993-1994, 1994) of expressed sequence tags (dbEST) using the sequence of IMAGE Clone ID#485825 as probe came up with a clone with a longer cDNA insert (clone ID#663789) from the Genbank database with perfect homology to the IMAGE Clone ID#485825. Restriction mapping and DNA sequence analysis of IMAGE Clone ID#663789 (Genome Systems, St. Louis, Mo.) showed it to be a longer cDNA clone with extensive sequence homology with the coding region of hCDS1 but still missing the first 60 amino acids in the coding region. To isolate the 5′-coding region of hCDS2 cDNA, a synthetic oligonucleotide, 5′- AGGACGCATA TGAGTGGTAG AC-3′ (oCDS2 — 2R), complementary to a region spanning the Nde I site near the 5′ portion of clone ID#663789 was used in combination with a forward vector primer (o.sport.1), 5′- GACTCTAGCC TAGGCTTTTG C-3′ for amplification of the 5′-region from a pCMV.SPORT human leukocyte cDNA library (Life Technologies, Gaithersburg, Md.). PCR fragments generated that were >400 bp were inserted into the pGEM-T vector (Promega, Madison, Wis.) for further analysis. Restriction mapping and DNA sequence analysis showed one of the clones, pCDS2.H7, to be homologous to the N-terminal coding region of hCDS1.
[0043] To assemble the putative full-length human CDS cDNA clone, the 420 bp Acc65 I-Nde I fragment from pCDS2.H7 and the 1200 bp Nde I-Xba I fragment from clone ID#663789 were isolated. These two fragments were inserted into a Acc65 I and Xba I digested vector pBluescript SK(−)II vector via a three-part ligation to generate pSK.CDS2.
[0044] [0044]FIG. 8 shows the DNA sequence ID of the hCDS2. The nucleotide sequence analysis and restriction mapping of the cDNA clone revealed a 5′-untranslated region of 24 bp, an open reading frame capable of encoding a 445 amino acid polypeptide that spans nucleotide positions 25 to 1362 and a 3′-untranslated region of 1126 bp. The ATG initiation site for translation was localized at nucleotide positions 25-27 and fulfilled the requirement for an adequate initiation site according to Kozak (Kozak, Critical Rev. Biochem. Mol. Biol. 27:385-402, 1992).
[0045] Amino acid sequence alignment of the hCDS2 coding sequence with the human CDS1 shows 64% identity (FIG. 9). The amino acids that are identical between the two sequences are highlighted.
[0046] Expression of human CDS cDNA in mammalian cells
[0047] hCDS1
[0048] To see if overexpression of hCDS1 would have any effect on mammalian cells, the entire cDNA insert (˜2,000 base pairs) from pSK.hcds was cleaved with Asp718 I and Not I for insertion into the mammalian expression vector pCE2 to generate pCE2.hCDS. The plasmid pCE2 was derived from pREP7b (Leung et al. Proc. Natl. Acad. Sci. USA, 92:4813-4817, 1995) with the RSV promoter region replaced by the CMV enhancer and the elongation factor-1α (EF-1α) promoter and intron. The CMV enhancer came from a 380 base pair Xba I-Sph I fragment produced by PCR from pCEP4 (Invitrogen, San Diego, Calif.) using the primers 5′-GGCTCTAGAT ATTAATAGTA ATCAATTAC-3′ (SEQ ID NO. 7) and 5′-CCTCACGCAT GCACCATGGT AATAGC-3′ (SEQ ID NO. 8). The EF-1α promoter and intron (Uetsuki et al., J. Biol. Chem., 264:5791-5798, 1989) came from a 1200 base pair Sph I-Asp718 I fragment produced by PCR from human genomic DNA using the primers 5′-GGTGCATGCG TGAGGCTCCG GTGC-3′ (SEQ ID NO. 9) and 5′-GTAGTTTTCA CGGTACCTGA AATGGAAG-3′ (SEQ ID NO. 10). These 2 fragments were ligated into a Xba I/Asp718 I digested vector derived from pREP7b to generate pCE2.
[0049] A second clone, pCE2.hCDS2, was constructed that lacked the human CDS 3′-UT region (520 nt). An Asp718 I (in the multiple cloning site)/NcoI fragment and a NcoI/BamHI fragment from pSK.hCDS were combined in a three-part ligation with Asp718 I/BamHI digested pCE2. Northern blot analysis of 293-EBNA human embryonic kidney cells transiently transfected with CDS cDNA expression plasmids (pCE2.hCDS or pCE2.hCDS2) showed that deletion of the entire 3′-UT region had little effect on CDS steady-state mRNA levels.
[0050] The CDS activity in transfected cell fractions (membranes, cytosol, nuclei/unbroken cells) was determined by incorporation of (α- 32 P)CTP into ( 32 P)CDP-DAG in the presence of exogenously added PA substrate. Cells were fractionated by resuspending previously frozen cell pellets in cold hypotonic lysis buffer (HLB; 10 mM KCl, 1.5 mM MgCl 2 , 10 mM Tris, pH 7.4, 2 mM benzamidine HCl, and 10 μg/ml each leupeptin, soybean trypsin inhibitor, and pepstatin A) at approx. 5×10 7 cells/ml. After 10 min. on ice, cells were dounced (Wheaton pestle A) 40 strokes, then spun 500 ×g, 10 min. at 4° C. to remove nuclei and unbroken cells. The resuspension of the pellet, incubation, and low speed spin were repeated twice. The final “nuclei/unbroken cells” pellet was resuspended in 50-100 μl HLB. Supernatants were spun at 109,000× g, 30 min. at 4° C. generating “cytosol” supernates and “membrane” pellets. The pellets were resuspended in 150-225 μl HLB. An aliquot of each fraction was removed for determination of protein concentration by a BCA assay. Fractions were stored at −70° C. All assays were done on fractions after one thaw.
[0051] The in vitro CDS activity assay conditions were a modification of methods described previously (Mok et al., FEBS Letters 312:236-240,1992; and Wu et al., Nature 373:216-222,1995). Briefly, each 0.3 ml reaction combined 0.23 mM PA (Sigma; from egg yolk lecithin), 50 mM Tris-maleate, pH 7.0, 1.5% Triton X-100, 0.5 mM DTT, 75-500 μg protein from cell fractions, 30 mM MgCl 2 , and 2 μCi (α- 32 P)CTP. MgCl 2 and (α- 32 P)CTP were added just prior to a 10 min. incubation at 37° C. The reactions were terminated with 4 ml chloroform:methanol (1:1) and vortexing. The organic phase was extracted three times with 1.8 ml 0.1 N HCl with 1 M NaCl, and vortexing. Radioactivity in the organic phase was determined by scintillation counting or TLC.
[0052] A flip-flop TLC (ffTLC) system (Gruchalla et al., J. Immunol. 144:2334-2342, 1990) was modified for the separation of CDP-DAG and PA. Specifically, 200 ml of organic phase was dried and brought up in 20 μL CHCl 3 :MeOH (2:1) and spotted in the center of a 20×20 cm TLC plate (Analtech Silica Gel HP-HLF). TLC was run in CHCl 3 :MeOH:NH 4 OH:H 2 O (65:30:4:1) until the solvent had reached the top of the plate. In this solvent system, neutral and cationic lipids migrate, whereas PA, CDP-DAG and other anionic lipids stay near the origin. The plate was dried and visualized by UV with 0.05% primulin stain (Sigma, St. Louis, Mo.) in 80% acetone. The plate was cut below the PC standard, and the bottom half of the plate was rotated 180° and run in CHCl 3 :MeOH:Acetic Acid:H 2 O (80:25:15:5) to enable migration of the anionic lipids until the solvent reached the top of the plate. The radioactive bands on the TLC plate were quantified using a STORM® phosphorimager (Molecular Dynamics, Sunnyvale, Calif.). Non-radiolabeled lipid standards were stained with primulin and visualized by fluorescence using the STORM®.
[0053] [0053]FIG. 5 shows the results of in vitro CDS activity assays on cell fractions from stable transfectants of NCI-H460 cells. CDS activity was assessed by conversion of (α- 32 P)CTP to ( 32 P)CDP-DAG in in vitro reactions that required addition of an exogenous PA substrate. This is a representative histogram comparing the radiolabel incorporated into various cell fractions (membranes, cytosol, and nuclei/unbroken cells) from NCI-H460 cells stably transfected with the hCDS1 cDNA (pCE2.hCDS) or vector only (pCE2). In all fractions, the CDS cDNA increased radiolabel in the organic phase of the reactions. Total CDS activity was much greater in membrane fractions, as would be expected for membrane associated CDS, compared to cytosol fractions. Activity in unbroken cells masked the activity specific to nuclei.
[0054] [0054]FIG. 6 is a representative phosphorimage of [ 32 P]phospholipids from membrane fraction CDS assay reactions after the second dimension of ffTLC. FIG. 6 confirms that the radiolabeled product found in the membrane fractions does migrate with a CDP-DAG standard on TLC. The identities of labeled bands were determined by migration of phospholipid standards visualized by UV or FL imaging on the STORM after primulin staining. Lanes 1-3 represent triplicate samples derived from membranes of NCI-H460 cells transfected with the hCDS1 expression vector, and lanes 4-6 represent triplicate samples from transfectants with the control vector. Cells transfected with the hCDS1 cDNA showed 1.6-2.4 fold more CDS activity in membrane fractions than vector transfectants. The relative CDS activity between CDS transfectants and vector transfectants was similar when determined by scintillation counting or TLC analysis. Similar CDS activity was seen in two different transfected human cell lines, NCI-H460 and ECV304. The average specific activity of CDS in membranes of CDS transfectants was 2.7 fmol/min/mg protein compared to 1.4 fmol/min/mg protein in membranes of vector transfectants. These results demonstrated that overexpression of the human CDS cDNA clone lead to an increase in CDS activity in cell fractions and that activity in an in vitro assay was completely dependent on the addition of PA. These data indicate that the human cDNA clone of SEQ ID NO. 1 does encode CDS activity.
[0055] hCDS2
[0056] To see if overexpression of hCDS2 has an effect in mammalian cells, the entire cDNA insert (˜1,900 bp) from pSK.CDS2 was cleaved with Asp718 I and Xba I for insertion into a mammalian inducible expression vector pIND (Invitrogen, San Diego, Calif.) to generate pI_CDS2.
[0057] pI_CDS2 DNA and pVgRXR (Invitrogen, San Diego, Calif.) DNA were co-transfected into ECV304 cells (American Type Culture Collection, Rockville, Md.) with a Cell-Porator™ (Life Technologies, Gaithersburg, Md.) using conditions described previously (Cachianes, et al., Biotechniques 15:255-259, 1993). After adherence of the transfected cells 24 hours later, the cells were grown in the presence of 500 μg/ml G418 (Life Technologies, Gaithersburg, Md.) and 100 μg/ml Zeocin (Invitrogen, San Diego, Calif.) to select for cells that had incorporated both plasmids. G418 and Zeocin resistant clones that expressed CDS2 mRNA at a level more than 10 fold higher in the presence of muristerone A (Invitrogen, San Diego, Calif.) relative to uninduced or untranfected cells based on Northern Blot analysis (Kroczek, et al., Anal. Biochem. 184: 90-95, 1990) were selected for further study.
[0058] The CDS activity in ECV304 cells transfected with pI_CDS2 DNA and pVgRXR DNA with or without muristerone A induction was compared using a TLC assay (Weeks et al, DNA Cell Biol. 16: 281-289, 1997).
[0059] [0059]FIG. 10 shows an example of hCDS2 assay results by measuring the production of [32P]CDP-DAG after TLC analysis. The identities of labeled bands were determined based on Rf values obtained for standard phospholipids visualized by primulin staining. The left two bars represent triplicate samples derived from ECV304 cells transfected with pVgRXR and the control vector pIND in the absence or presence of the inducer muristerone A. The enzyme activity found here represents endogenous CDS activity found in ECV304 cells, as cells without or with muristerone A treatment produced similar activity. The right two bars represent triplicate samples derived from ECV304 cells transfected with pVgRXR and the inducible CDS2 vector pI_CDS2 in the absence or presence of the inducer muristerone A. Quantitation of the radioactive bands corresponding to CDP-DAG shows cells transfected with the inducible hCDS2 expression plasmid have an approximately two fold increase in activity after induction with muristerone A compared to same cells without induction or to vector control cells either with or without induction, showing that the hCDS2 cDNA clone encode a protein having CDS activity.
[0060] Complementation of yeast cds1 mutant with hCDS1
[0061] As the yeast CDS gene is essential for growth (Shen et al., J. Biol. Chem. 271:789-795, 1996), another way to show that the cDNA does encode CDS activity was to determine if the human CDS cDNA will complement the growth defect of a mutant yeast strain with a deletion in the endogenous yeast CDS gene. Accordingly, the hCDS1 cDNA was cloned downstream of a GAL1 promoter in a yeast expression vector. Specifically, a Hind III-Sac I fragment from pSK.hCDS was inserted into pYES.LEU vector to generate pYES.hCDS. pYES.LEU was derived from pYES2 (Invitrogen, San Diego, Calif.) by inserting a BspH I fragment containing a LEU2 marker from pRS315 (Sikorski et al., Genetics 122:19-27, 1989) into the Nco I of pYES2. pYES.hCDS was introduced into a null cds1 strain of yeast, YSD90A (Shen et al., J. Biol. Chem. 271:789-795, 1996), with a covering plasmid, pSDG1, carrying the functional yeast CDS1. The latter plasmid was cured from cells by growth in media lacking leucine but containing uracil and galactose. PCR analysis confirmed the absence of the yeast CDS1 gene and Northern blot analysis verified expression of the hCDS1 cDNA. This strain was found to be absolutely dependent on galactose for growth. Galactose activates the GAL1 promoter for the production of human CDS protein. When the carbon source was switched to glucose, which would shut down the GAL1 promoter, growth stopped completely in less than a generation. These data show the human CDS was able to complement the growth defect of a yeast cds1 mutant.
[0062] The cells grown on galactose were lysed and assayed for CDS activity according to the assay method described (Shen et al., J. Biol. Chem. 271:789-795, 1996). The specific activity using yeast conditions showed activity at 20% of single copy CDS1 wild type activity. This is consistent with the above plasmid in a wild type background showing approximately 1.3 fold increase in activity when grown on galactose versus glucose.
[0063] The following experiment found that hCDS1 over-expression enhanced cytokine induced signaling in cells. Over-expression of CDS was expected to alter the cellular level of various lipid second messengers such as PA, IP 3 and DAG (Kent, Anal. Rev. Biochem. 64:315-343, 1995) and hence modulates cytokine induced signaling response in cells. To test this hypothesis, a hCDS1 expression plasmid (pCE2.hCDS), or vector (pCE2) were stably transfected into ECV304 cells (American Type Culture Collection, Rockville, Md.), an endothelial cell line that produces IL-6 and TNF-α upon stimulation with IL-1β. FIG. 7 shows that the secretion of TNF-α IL-6 in ECV304 cells stably transfected with CDS expression vector increased by >5 fold relative to ECV304 cells stably transfected with control vector after stimulation with 1 ng/ml IL-1β. However, there was little effect on the basal level of cytokine release, suggesting that over-expression of CDS amplified the cytokine signaling response, as opposed to enhancing the steady-state, basal signal, in these cells.
[0064] Expression of hCDS1 and hCDS2 mRNA in cancer versus normal prostate tissue
[0065] To examine if CDS mRNA expression in cancer versus normal tissues, RT-PCR was performed on specimens of prostate cancer tissues and the corresponding normal prostate tissues in the surgical margins from four independent patients. FIG. 11 shows hCDS1 mRNA was elevated in prostate cancer in 2 out of 4 patients, whereas hCDS2 mRNA was elevated in prostate cancer in 3 out of 4 patients. A housekeeping gene β2-microglobulin mRNA level was found to be similar in normal and cancer prostate tissues. ETS-2, a transcription factor reported to be elevated in prostate cancer (Liu et al., Prostate 30: 145-153, 1997), was found to be elevated in the same 3 out of 4 patients examined here, suggesting hCDS2, like ETS-2, may be a target for drug intervention in cancer therapy.
[0066] CDS Polypeptide Synthesis
[0067] Polypeptides of the present invention can be synthesized by such commonly used methods as t-BOC or FMOC protection of alpha-amino groups. Both methods involve step-wise syntheses whereby a single amino acid is added at each step starting from the C-terminus of the peptide (Coligan et al., Current Protocols in Immunology, Wiley Interscience, Unit 9, 1991). In addition, polypeptides of the present invention can also be synthesized by solid phase synthesis methods (e.g., Merrifield, J. Am. Chem. Soc. 85:2149, 1962; and Steward and Young, Solid Phase Peptide Synthesis, Freeman, San Francisco pp. 27-62, 1969) using copolyol (styrene-divinylbenzene) containing 0.1-1.0 mM amines/g polymer. On completion of chemical synthesis, the polypeptides can be deprotected and cleaved from the polymer by treatment with liquid HF 10% anisole for about 15-60 min at 0° C. After evaporation of the reagents, the peptides are extracted from the polymer with 1% acetic acid solution, which is then lyophilized to yield crude material. This can normally be purified by such techniques as gel filtration of Sephadex G-15 using 5% acetic acid as a solvent. Lyophilization of appropriate fractions of the column will yield a homogeneous polypeptide or polypeptide derivatives, which are characterized by such standard techniques as amino acid analysis, thin layer chromatography, high performance liquid chromatography, ultraviolet absorption spectroscopsy, molar rotation, solubility and quantitated by solid phase Edman degradation.
[0068] CDS Polynucleotides
[0069] The invention also provides polynucleotides which encode the CDS polypeptide of the invention. As used herein, “polynucleotide” refers to a polymer of deoxyribonucleotides or ribonucleotides in the form of a separate fragment or as a component of a larger construct. DNA encoding the polypeptide of the invention can be assembled from cDNA fragments or from oligonucleotides which provide a synthetic gene which is capable of being expressed in a recombinant transcriptional unit. Polynucleotide sequences of the invention include DNA, RNA and cDNA sequences. Preferably, the nucleotide sequence encoding CDS is the sequence of SEQ ID NO. 1 or of FIG. 8. DNA sequences of the present invention can be obtained by several methods. For example, the DNA can be isolated using hybridization procedures which are known in the art. Such hybridization procedures include, for example, hybridization of probes to genomic or cDNA libraries to detect shared nucleotide sequences, antibody screening of expression libraries to detect common antigenic epitopes or shared structural features and synthesis by the polymerase chain reaction (PCR). Such hybridization includes hybridization under high stringency conditions as described above.
[0070] Hybridization procedures are useful for screening recombinant clones by using labeled mixed synthetic oligonucleotides probes, wherein each probe is potentially the complete complement of a specific DNA sequence in a hybridization sample which includes a heterogeneous mixture of denatured double-stranded DNA. For such screening, hybridization is preferably performed on either single-stranded DNA or denatured double-stranded DNA. Hybridization is particularly useful for detection of cDNA clones derived from sources where an extremely low amount of mRNA sequences relating to the polypeptide of interest are present. Using stringent hybridization conditions to avoid non-specific binding, it is possible to allow an autoradiographic visualization of a specific genomic DNA or cDNA clone by the hybridization of the target DNA to a radiolabeled probe, which is its complement (Wallace et al. Nucl. Acid Res. 9:879, 1981). Specific DNA sequences encoding CDS can also be obtained by isolation and cloning of double-stranded DNA sequences from the genomic DNA, chemical manufacture of a DNA sequence to provide the necessary codons for the complete polypeptide of interest or portions of the sequence for use in PCR to obtain the complete sequence, and in vitro synthesis of a double-stranded DNA sequence by reverse transcription of mRNA isolated from a eukaryotic donor cell. In the latter case, a double-stranded DNA complement of mRNA is eventually formed which is generally referred to as cDNA. Of these three methods for developing specific DNA sequences for use in recombinant procedures, the isolation of cDNA clones is the most useful. This is especially true when it is desirable to obtain the microbial expression of mammalian polypeptides since the presence of introns in genomic DNA clones can prevent accurate expression.
[0071] The synthesis of DNA sequences is sometimes a method that is preferred when the entire sequence of amino acids residues of the desired polypeptide product is known When the entire sequence of amino acid residues of the desired polypeptide is not known, direct synthesis of DNA sequences is not possible and it is desirable to synthesize cDNA sequences isolation can be done, for example, by formation of plasmid- or phage-carrying cDNA libraries which are derived from reverse transcription of mRNA. mRNA is abundant in donor cells that have high levels of genetic expression. In the event of lower levels of expression, PCR techniques can be used to isolate and amplify the cDNA sequence of interest. Using synthesized oligonucleotides corresponding exactly, or with some degeneracy, to known CDS amino acid or nucleotide sequences, one can use PCR to obtain and clone the sequence between the oligonucleotides. The oligonucleotide may represent invariant regions of the CDS sequence and PCR may identify sequences (isoforms) with variations from SEQ ID NO. 1 or FIG. 8.
[0072] A cDNA expression library, such as lambda gt11, can be screened indirectly for the CDS polypeptide, using antibodies specific for CDS. Such antibodies can be either polyclonal or monoclonal, derived from the entire CDS protein or fragments thereof, and used to detect and isolate expressed proteins indicative of the presence of CDS cDNA.
[0073] A polynucleotide sequence can be deduced from an amino acid sequence by using the genetic code, however the degeneracy of the code must be taken into account. Polynucleotides of this invention include variant polynucleotide sequences which code for the same amino acids as a result of degeneracy in the genetic code. There are 20 natural amino acids, most of which are specified by more that one codon (a three base sequence). Therefore, as long as the amino acid sequence of CDS results in a biologically active polypeptide (at least, in the case of the sense polynucleotide strand), all degenerate nucleotide sequences are included in the invention. The polynucleotide sequence for CDS also includes sequences complementary to the polynucleotides encoding CDS (antisense sequences). Antisense nucleic acids are DNA, and RNA molecules that are complementary to at least a portion of a specific mRNA molecule (Weintraub, Sci. Amer. 262:40, 1990). The invention embraces all antisense polynucleotides capable of inhibiting the production of CDS polypeptide. In the cell, the antisense nucleic acids hybridize to the corresponding mRNA, forming a double-stranded molecule. The antisense nucleic acids interfere with the translation of mRNA since the cell cannot translate mRNA that is double-stranded. Antisense oligomers of about 15 nucleotides are preferred, since they are easily synthesized and are less likely to cause problems than larger molecules when introduced into the target CDS-producing cell. The use of antisense methods to inhibit translation of genes is known (e.g., Marcus-Sakura, Anal. Biochem. 172:289, 1988).
[0074] In addition, ribozyme nucleotide sequences for CDS are included in this invention. Ribozymes are hybrid RNA:DNA molecules possessing an ability to specifically cleave other single-stranded RNA in a manner analogous to DNA restriction endonucleases. Through the modification of nucleotide sequences which encode such RNAs, it is possible to engineer molecules that recognize specific nucleotide sequences in an RNA molecule and cleave it (Cech, J. Amer. Med. Assn. 260:3030, 1988). An advantage of this approach is that only mRNAs with particular sequences are inactivated because they are sequence-specific.
[0075] The CDS DNA sequence may be inserted into an appropriate recombinant expression vector. The term “recombinant expression vector” refers to a plasmid, virus or other vehicle that has been manipulated by insertion or incorporation of the genetic sequences. Such expression vectors contain a promoter sequence which facilitates efficient transcription of the inserted genetic sequence in the host. The expression vector typically contains an origin of replication, a promoter, as well as specific genes which allow phenotypic selection of the transformed cells. Vectors suitable for use in the present invention include, for example, vectors with a bacterial promoter and ribosome binding site for expression in bacteria (Gold, Meth. Enzymol. 185:11, 1990), expression vectors with mammalian or viral promoter and enhancer for expression in mammalian cells (Kaufman, Meth. Enzymol. 185:487, 1990) and baculovirus-derived vectors for expression in insect cells (Luckow et al., J. Virol. 67:4566, 1993). The DNA segment can be present in the vector operably linked to regulatory elements, for example, constitutive or inducible promoters (e.g., T7, metallothionein I, CMV, or polyhedren promoters).
[0076] The vector may include a phenotypically selectable marker to identify host cells which contain the expression vector. Examples of markers typically used in prokaryotic expression vectors include antibiotic resistance genes for ampicillin (β-lactamases), tetracycline and chloramphenicol (chloramphenicol acetyltransferase). Examples of such markers typically used in mammalian expression vectors include the gene for adenosine deaminase (ADA), aminoglycoside phosphotransferase (neo, G418), dihydrofolate reductase (DHFR), hygromycin-B-phosphotransferase (HPH), thymidine kinase (TK), and xanthine guanine phosphoriboseyltransferase (XGPRT, gpt).
[0077] In another preferred embodiment, the expression system used is one driven by the baculovirus polyhedrin promoter. The gene encoding the polypeptide can be manipulated by standard techniques in order to facilitate cloning into the baculovirus vector. A preferred baculovirus vector is the pBlueBac vector (Invitrogen, Sorrento, Calif.). The vector carrying the gene for the polypeptide is transfected into Spodoptera frugiperda (Sf9) cells by standard protocols, and the cells are cultured and processed to produce the recombinant polypeptide. See Summers et al., A Manual for Methods of Baculovirus Vectors and Insect Cell Culture Procedures, Texas Agricultural Experimental Station.
[0078] Once the entire coding sequence of the gene for the polypeptides has been determined, the gene can be expressed in any number of different recombinant DNA expression systems to generate large amounts of polypeptide. Included within the present invention are polypeptides having native glycosylation sequences, and deglycosylated or unglycosylated polypeptides prepared by the methods described below. Examples of expression systems known to the skilled practitioner in the art include bacteria such as E. coli, yeast such as Pichia pastoris, baculovirus, and mammalian expression systems such as in COS or CHO cells.
[0079] The gene or gene fragment encoding the desired polypeptide can be inserted into an expression vector by standard subcloning techniques. In a preferred embodiment, an E. coli expression vector is used which produces the recombinant protein as a fusion protein, allowing rapid affinity purification of the protein. Examples of such fusion protein expression systems are the glutathione S-transferase system (Pharmacia, Piscataway, N.J.), the maltose binding protein system (NEB, Beverley, Mass.), the thiofusion system (Invotrogen, San Diego, Calif.), the FLAG system (IBI, New Haven, Conn.), and the 6xHis system (Qiagen, Chatsworth, Calif.). Some of these systems produce recombinant polypeptides bearing only a small number of additional amino acids, which are unlikely to affect the CDS activity of the recombinant polypeptide. For example, both the FLAG system and the 6xHis system add only short sequences, both of which are known to be poorly antigenic and which do not adversely affect folding of the polypeptide to its native conformation. Other fusion systems produce proteins where it is desirable to excise the fusion partner from the desired protein. In a preferred embodiment, the fusion partner is linked to the recombinant polypeptide by a peptide sequence containing a specific recognition sequence for a protease. Examples of suitable sequences are those recognized by the Tobacco Etch Virus protease (Life Technologies, Gaithersburg, Md.) or Factor Xa (New England Biolabs, Beverley, Mass.) or enterokinase (Invotrogen, San Diego, Calif.).
[0080] Production of Polypeptides
[0081] Polynucleotide sequences encoding CDS polypeptides of the invention can be expressed in either prokaryotes or eukaryotes. Hosts can include microbial (bacterial), yeast, insect and mammalian organisms. Methods of expressing DNA sequences inserted downstream of prokaryotic or viral regulatory sequences in prokaryotes are known in the art (Makrides, Microbio. Rev. 60:512, 1996). Biologically functional viral and plasmid DNA vectors capable of expression and replication in a eukaryotic host are known in the art (Cachianes, Biotechniques 15:255, 1993). Such vectors are used to incorporate DNA sequences of the invention. DNA sequences encoding the inventive polypeptides can be expressed in vitro by DNA transfer into a suitable host using known methods of transfection.
[0082] Sequences encoding CDS polypeptides may be inserted into a recombinant expression vector. The term “recombinant expression vector” refers to a plasmid, virus or other vehicle that has been manipulated by inserting or incorporating genetic sequences. Such expression vectors contain a promoter sequence which facilitates efficient transcription of the inserted genetic sequence of the host. The expression vector typically contains an origin of replication and a promoter, as well as specific genes which allow phenotypic selection of the transformed cells. The DNA segment can be present in the vector, operably linked to regulatory elements, for example, a promoter (e.g., T7, metallothionein I, or polyhedren promoters). Vectors suitable for use in the present invention include, for example, bacterial expression vectors, with bacterial promoter and ribosome binding sites, for expression in bacteria (Gold, Meth. Enzymol. 185:11, 1990), expression vector with animal promoter and enhancer for expression in mammalian cells (Kaufman, Meth. Enzymol. 185:487, 1990) and baculovirus-derived vectors for expression in insect cells (Luckow et al., J. Virol. 67:4566, 1993).
[0083] The vector may include a phenotypically selectable marker to identify host cells which contain the expression vector. Examples of markers typically used in prokaryotic expression vectors include antibiotic resistance genes for ampicillin (β-lactamases), tetracycline and chloramphenicol (chloramphenicol acetyltransferase). Examples of such markers typically used in mammalian expression vectors include the gene for adenosine deaminase (ADA), aminoglycoside phosphotransferase (neo, G418), dihydrofolate reductase (DHFR), hygromycin-B-phosphotransferase (BPH), thymidine kinase (TK), and xanthine guanine phosphoriboseyltransferase (XGPRT, gpt).
[0084] In another preferred embodiment, the expression system used is one driven by the baculovirus polyhedrin promoter. The polynucleotide encoding CDS can be manipulated by standard techniques in order to facilitate cloning into the baculovirus vector. See Ausubel et al., supra. A preferred baculovirus vector is the pBlueBac vector (Invitrogen, Sorrento, Calif.). The vector carrying a polynucleotide encoding CDS is transfected into Spodoptera frugiperda (Sf9) cells by standard protocols, and the cells are cultured and processed to produce the recombinant polypeptide. See Summers et al., A Manual for Methods of Baculovirus Vectors and Insect Cell Culture Procedures, Texas Agricultural Experimental Station.
[0085] The polynucleotides of the present invention can be expressed in any number of different recombinant DNA expression systems to generate large amounts of polypeptide. Included within the present invention are CDS polypeptides having native glycosylation sequences, and deglycosylated or unglycosylated polypeptides prepared by the methods described below. Examples of expression systems known to the skilled practitioner in the art include bacteria such as E. coli, yeast such as Pichia pastoris, baculovirus, and mammalian expression systems such as in Cos or CHO cells.
[0086] The polynucleotides of the present invention can be inserted into an expression vector by standard subcloning techniques. In a preferred embodiment, an E. coli expression vector is used which produces the recombinant protein as a fusion protein, allowing rapid affinity purification of the protein. Examples of such fusion protein expression systems are the glutathione S-transferase system (Pharmacia, Piscataway, N.J.), the maltose binding protein system (NEB, Beverley, Mass.), the thiofusion system (Invitrogen, San Diego, Calif.), the Strep-tag II system (Genosys, Woodlands, Tex.), the FLAG system (IBI, New Haven, Conn.), and the 6xHis system (Qiagen, Chatsworth, Calif.). Some of these systems produce recombinant polypeptides bearing only a small number of additional amino acids, which are unlikely to affect the CDS ability of the recombinant polypeptide. For example, both the FLAG system and the 6xHis system add only short sequences, both of which are known to be poorly antigenic and which do not adversely affect folding of the polypeptide to its native conformation. Other fusion systems produce proteins where it is desirable to excise the fusion partner from the desired protein. In a preferred embodiment, the fusion partner is linked to the recombinant polypeptide by a peptide sequence containing a specific recognition sequence for a protease. Examples of suitable sequences are those recognized by the Tobacco Etch Virus protease (Life Technologies, Gaithersburg, Md.) or Factor Xa (New England Biolabs, Beverley, Mass.) or enterokinase (Invitrogen, San Diego, Calif.).
[0087] In an embodiment of the present invention, the polynucleotides encoding CDS are analyzed to detect putative transmembrane sequences. Such sequences are typically very hydrophobic and are readily detected by the use of standard sequence analysis software, such as MacDNASIS (Hitachi, San Bruno, Calif.). The presence of transmembrane sequences is often deleterious when a recombinant protein is synthesized in many expression systems, especially in E. coli, as it leads to the production of insoluble aggregates which are difficult to renature into the native conformation of the polypeptide.
[0088] Accordingly, deletion of one or more of the transmembrane sequences may be desirable. Deletion of transmembrane sequences typically does not significantly alter the conformation or activity of the remaining polypeptide structure. However, one can determine whether deletion of one or more of the transmembrane sequences has effected the biological activity of the CDS protein by, for example, assaying the activity of the CDS protein containing one or more deleted sequences and comparing this activity to that of unrnodified CDS. Examples of assays for CDS activity are described above.
[0089] Moreover, transmembrane sequences, being by definition embedded within a membrane, are inaccessible as antigenic determinants to a host immune system. Antibodies to these sequences will not, therefore, provide immunity to the host and, hence, little is lost in terms of generating monoclonal or polyclonal antibodies by omitting such sequences from the recombinant polypeptides of the invention. Deletion of transmembrane-encoding sequences from the polynucleotide used for expression can be achieved by standard techniques. See Ausubel et al., zipra, Chapter 8. For example, fortuitously-placed restriction enzyme sites can be used to excise the desired gene fragment, or the PCR can be used to amplify only the desired part of the gene.
[0090] Transformation of a host cell with recombinant DNA may be carried out by conventional techniques. When the host is prokaryotic, such as E. coli, competent cells which are capable of DNA uptake can be prepared from cells harvested after exponential growth phases and subsequently treated by a CaCl 2 method using standard procedures. Alternatively, MgCl 2 or RbCl can be used. Transformation can also be performed after forming a protoplast of the host cell or by electroporation.
[0091] When the host is a eukaryote, methods of transfection of DNA, such as calcium phosphate co-precipitates, conventional mechanical procedures, (e.g., microinjection), electroporation, liposome-encased plasmids, or virus vectors may be used. Eukaryotic cells can also be cotransformed with DNA sequences encoding CDS polypeptides of the present invention, and a second foreign DNA molecule encoding a selectable phenotype, such as the herpes simplex thymidine kinase gene. Another method uses a eukaryotic viral vector, such as simian virus 40 (SV40) or bovine papilloma virus to transiently infect or transform eukaryotic cells and express the CDS polypeptides.
[0092] Expression vectors that are suitable for production of CDS polypeptides preferably contain (1) prokaryotic DNA elements coding for a bacterial replication origin and an antibiotic resistance marker to provide for the growth and selection of the expression vector in a bacterial host; (2) eukaryotic DNA elements that control initiation of transcription, such as a promoter; and (3) DNA elements that control the processing of transcripts, such as a transcription termination/polyadenylation sequence. CDS polypeptides of the present invention preferably are expressed in eukaryotic cells, such as mammalian, insect and yeast cells. Mammalian cells are especially preferred eukaryotic hosts because mammalian cells provide suitable post-translational modifications such as glycosylation. Examples of mammalian host cells include Chinese hamster ovary cells (CHO-K1; ATCC CCL61), rat pituitary cells (GH 1 ; ATCC CCL82), HeLa S3 cells (ATCC CCL2.2), rat hepatoma cells (H-4-II-E; ATCC CRL1548) SV40-transformed monkey kidney cells (COS-1; ATCC CRL 1650) and murine embryonic cells (NIH-3T3; ATCC CRL 1658). For a mammalian host, the transcriptional and translational regulatory signals may be derived from viral sources, such as adenovirus, bovine papilloma virus, simian virus, or the like, in which the regulatory signals are associated with a particular gene which has a high level of expression. Suitable transcriptional and translational regulatory sequences also can be obtained from mammalian genes, such as actin, collagen, myosin, and metallothionein genes.
[0093] Transcriptional regulatory sequences include a promoter region sufficient to direct the initiation of RNA synthesis. Suitable eukaryotic promoters include the promoter of the mouse metallothionein I gene (Hamer et al., J. Molec. Appl. Genet. 1:273,1982); the TK promoter of Herpes virus (McKnight, Cell 31: 355, 1982); the SV40 early promoter (Benoist et al., Nature 290:304, 1981); the Rous sarcoma virus promoter (Gorman et al., Proc. Nat'l. Acad. Sci. USA 79:6777, 1982); and the cytomegalovirus promoter (Foecking et al., Gene 45:101, 1980). Alternatively, a prokaryotic promoter, such as the bacteriophage T3 RNA polymerase promoter, can be used to control fusion gene expression if the prokaryotic promoter is regulated by a eukaryotic promoter (Zhou et al., Mol. Cell. Biol. 10:4529, 1990; Kaufman et al, Nucl. Acids Res. 19:4485, 1991).
[0094] An expression vector can be introduced into host cells using a variety of techniques including calcium phosphate transfection, liposome-mediated transfection, electroporation, and the like. Preferably, transfected cells are selected and propagated wherein the expression vector is stably integrated in the host cell genome to produce stable transformants. Techniques for introducing vectors into eukaryotic cells and techniques for selecting stable transformants using a dominant selectable marker are described, for example, by Ausubel and by Murray (ed.), Gene Transfer and Expression Protocols (Humana Press 1991). Examples of mammalian host cells include COS, BHK, 293 and CHO cells.
[0095] Purification of Recombinant Polypeptides.
[0096] The polypeptide expressed in recombinant DNA expression systems can be obtained in large amounts and tested for biological activity. The recombinant bacterial cells, for example E. coli, are grown in any of a number of suitable media, for example LB, and the expression of the recombinant polypeptide induced by adding IPTG to the media or switching incubation to a higher temperature. After culturing the bacteria for a further period of between 2 and 24 hours, the cells are collected by centrifugation and washed to remove residual media. The bacterial cells are then lysed, for example, by disruption in a cell homogenizer and centrifuged to separate the dense inclusion bodies and cell membranes from the soluble cell components. This centrifugation can be performed under conditions whereby the dense inclusion bodies are selectively enriched by incorporation of sugars such as sucrose into the buffer and centrifugation at a selective speed. If the recombinant polypeptide is expressed in the inclusion, these can be washed in any of several solutions to remove some of the contaminating host proteins, then solubilized in solutions containing high concentrations of urea (e.g., 8 M) or chaotropic agents such as guanidine hydrochloride in the presence of reducing agents such as β-mercaptoethanol or DTT (dithiothreitol). At this stage it may be advantageous to incubate the polypeptide for several hours under conditions suitable for the polypeptide to undergo a refolding process into a conformation which more closely resembles that of the native polypeptide. Such conditions generally include low polypeptide (concentrations less than 500 mg/ml), low levels of reducing agent, concentrations of urea less than 2 M and often the presence of reagents such as a mixture of reduced and oxidized glutathione which facilitate the interchange of disulphide bonds within the protein molecule. The refolding process can be monitored, for example, by SDS-PAGE or with antibodies which are specific for the native molecule. Following refolding, the polypeptide can then be purified further and separated from the refolding mixture by chromatography on any of several supports including ion exchange resins, gel permeation resins or on a variety of affinity columns.
[0097] Isolation and purification of host cell expressed polypeptide, or fragments thereof may be carried out by conventional means including, but not limited to, preparative chromatography and immunological separations involving monoclonal or polyclonal antibodies.
[0098] These polypeptides may be produced in a variety of ways, including via recombinant DNA techniques, to enable large scale production of pure, active CDS useful for screening compounds for trilineage hematopoietic and anti-inflammatory therapeutic applications, and developing antibodies for therapeutic, diagnostic and research use.
[0099] Screening Assays using CDS Polypeptides
[0100] The CDS polypeptide of the present invention is useful in a screening methodology for identifying compounds or compositions which affect cellular signaling of an inflammatory response. This method comprises incubating the CDS polypeptides or a cell transfected with cDNA encoding CDS, with a suitable substrate, for example, PA, under conditions sufficient to allow the components to interact, and then measuring the effect of the compound or composition on CDS activity. See, for example, above, and Weeks et al., DNA Cell Biol. 16: 281-289, 1997. The observed effect on CDS may be either inhibitory or stimulatory. Such compounds or compositions to be tested can be selected from a combinatorial chemical library or any other suitable source (Hogan, Jr., Nat. Biotechnology 15:328, 1997).
[0101] Peptide Sequencing of Polypeptides
[0102] Substitutional variants typically contain the exchange of one amino acid for another at one or more sites within the protein, and are designed to modulate one or more properties of the polypeptides such as stability against proteolytic cleavage. Substitutions preferably are conservative, that is, one amino acid is replaced with one of similar shape and charge. Conservative substitutions are well known in the art and include, for example, the changes of alanine to serine; arginine to lysine; asparigine to glutamine or histidine; aspartate to glutamate; cysteine to serine; glutamine to asparigine; glutamate to aspartate; glycine to proline; histidine to asparigine or glutamine; isoleucine to leucine or valine; leucine to valine or isoleucine; lysine to arginine, glutamine, or glutamate; methionine to leucine or isoleucine; phenylalanine to tyrosine, leucine or methionine; serine to threonine; threonine to serine; tryptophan to tyrosine; tyrosine to tryptophan or phenylalanine; and valine to isoleucine or leucine. Insertional variants contain fusion proteins such as those used to allow rapid purification of the polypeptide and also can include hybrid polypeptides containing sequences from other proteins and polypeptides which are homologues of the inventive polypeptide. For example, an insertional variant could include portions of the amino acid sequence of the polypeptide from one species, together with portions of the homologous polypeptide from another species. Other insertional variants can include those in which additional amino acids are introduced within the coding sequence of the polypeptides. These typically are smaller insertions than the fusion proteins described above and are introduced, for example, to disrupt a protease cleavage site.
[0103] Anti-CDS Antibodies
[0104] Antibodies to human CDS protein can be obtained using the product of a CDS expression vector or synthetic peptides derived from the CDS coding sequence coupled to a carrier (Pasnett et al., J. Biol. Chem. 263:1728, 1988) as an antigen. The preparation of polyclonal antibodies is well-known to those of sldl in the art. See, for example, Green et al., “Production of Polyclonal Antisera,” in Immunochemical Protocols (Manson, ed.), pages 1-5 (Humana Press 1992). Alternatively, a CDS antibody of the present invention may be derived as a rodent monoclonal antibody (MAb). Rodent monoclonal antibodies to specific antigens may be obtained by methods known to those skilled in the art. See, for example, Kohler and Milstein, Nature 256:495, 1975, and Coligan et al. (eds.), Current Protocols in Immunology, 1:2.5.1-2.6.7 (John Wiley& Sons 1991). Briefly, monoclonal antibodies can be obtained by injecting mice with a composition comprising an antigen, verifying the presence of antibody production by removing a serum sample, removing the spleen to obtain B-lymphocytes, fusing the B-lymphocytes with myeloma cells to produce hybridomas, cloning the hybridomas, selecting positive clones which produce antibodies to the antigen, culturing the clones that produce antibodies to the antigen, and isolating the antibodies from the hybridoma cultures.
[0105] MAbs can be isolated and purified from hybridoma cultures by a variety of well-established techniques. Such isolation techniques include affinity chromatography with Protein-A Sepharose, size-exclusion chromatography, and ion-exchange chromatography. See, for example, Coligan at pages 2.7.1-2.7.12 and pages 2.9.1-2.9.3. Also, see Baines et al., “Purification of Immunoglobulin G (IgG),” in Methods in Molecular Biology, 10:79-104 Humana Press, Inc. 1992. A CDS antibody of the present invention may also be derived from a subhuman primate. General techniques for raising therapeutically useful antibodies in baboons may be found, for example, in Goldenberg et al., international patent publication No. WO 91/11465 (1991), and in Losman et al., Int. J. Cancer 46:310, 1990.
[0106] Alternatively, a therapeutically useful CDS antibody may be derived from a “humanized” monoclonal antibody. Humanized monoclonal antibodies are produced by transferring mouse complementarity determining regions from heavy and light chain variable regions of the mouse antibody into a human antibody variable domain, and then, substituting human residues in the framework regions of the murine counterparts. The use of antibody components derived from humanized monoclonal antibodies obviates potential problems associated with the immunogenicity of murine constant regions. General techniques for cloning murine immunoglobulin variable domains are described, for example, by the publication of Orlandi et al., Proc. Nat'l. Acad Sci. USA 86:3833, 1989. Techniques for producing humanized MAbs are described, for example, by Jones et al., Nature 321:522, 1986; Riechmann et al., Nature 332:323, 1988; Verhoeyen et al., Science 239:1534, 1988; Carter et al., Proc. Nat'l Acad Sci. USA 89:4285, 1992; Sandhu, Crit. Rev. Biotech. 12: 437, 1992; and Singer et al., J. Immun. 150:2844, 1993.
[0107] As an alternative, a CDS antibody of the present invention may be derived from human antibody fragments isolated from a combinatorial immunoglobulin library. See, for example, Barbas et al., METHODS: A Companion to Methods in Enzymology 2:119 1991, and Winter et al., Ann. Rev. Immunol. 12:433, 1994. Cloning and expression vectors that are useful for producing a human immunoglobulin phage library can be obtained, for example, from STRATAGENE Cloning Systems (La Jolla, Calif.). In addition, a CDS antibody of the present invention may be derived from a human monoclonal antibody. Such antibodies are obtained from transgenic mice that have been “engineered” to produce specific human antibodies in response to antigenic challenge. In this technique, elements of the human heavy and light chain loci are introduced into strains of mice derived from embryonic stem cell lines that contain targeted disruptions of the endogenous heavy chain and light chain loci. The transgenic mice can synthesize human antibodies specific for human antigens, and the mice can be used to produce human antibody-secreting hybridomas. Methods for obtaining human antibodies from transgenic mice are described by Green et al., Nature Genet. 7:13, 1994; Lonberg et al., Nature 368:856, 1994; and Taylor et al., Int. Immun. 6:579, 1994.
SEQUENCE LISTING
[0108] (2) INFORMATION FOR SEQ ID NO:1:
[0109] (i) SEQUENCE CHARACTERISTICS:
[0110] (a) LENGTH:2051
[0111] (b) TYPE: nucleic acid
1
19
1
2051
DNA
Homo sapiens
CDS
(150)..(1532)
1
tctatggtgg ggccgcgtta gtggctgcgg ctccgcggga ctccagggcg cggctgcgag 60
gtggcggggc gccccgcctg cagaaccctg cttgcagctc aggtttcggg gtgcttgagg 120
aggccgccac ggcagcgcgg gagcggaag atg ttg gag ctg agg cac cgg gga 173
Met Leu Glu Leu Arg His Arg Gly
1 5
agc tgc ccc ggc ccc agg gaa gcg gtg tcg ccg cca cac cgc gag gga 221
Ser Cys Pro Gly Pro Arg Glu Ala Val Ser Pro Pro His Arg Glu Gly
10 15 20
gag gcg gcc ggc ggc gac cac gaa acc gag agc acc agc gac aaa gaa 269
Glu Ala Ala Gly Gly Asp His Glu Thr Glu Ser Thr Ser Asp Lys Glu
25 30 35 40
aca gat att gat gac aga tat gga gat ttg gat tcc aga aca gat tct 317
Thr Asp Ile Asp Asp Arg Tyr Gly Asp Leu Asp Ser Arg Thr Asp Ser
45 50 55
gat att ccg gaa att cca cca tcc tca gat aga acc cct gag att ctc 365
Asp Ile Pro Glu Ile Pro Pro Ser Ser Asp Arg Thr Pro Glu Ile Leu
60 65 70
aaa aaa gct cta tct ggt tta tct tca agg tgg aaa aac tgg tgg ata 413
Lys Lys Ala Leu Ser Gly Leu Ser Ser Arg Trp Lys Asn Trp Trp Ile
75 80 85
cgt gga att ctc act cta act atg atc tcg ttg ttt ttc ctg atc atc 461
Arg Gly Ile Leu Thr Leu Thr Met Ile Ser Leu Phe Phe Leu Ile Ile
90 95 100
tat atg gga tcc ttc atg ctg atg ctt ctt gtt ctg ggc atc caa gtg 509
Tyr Met Gly Ser Phe Met Leu Met Leu Leu Val Leu Gly Ile Gln Val
105 110 115 120
aaa tgc ttc cat gaa att atc act ata ggt tat aga gtc tat cat tct 557
Lys Cys Phe His Glu Ile Ile Thr Ile Gly Tyr Arg Val Tyr His Ser
125 130 135
tat gat cta cca tgg ttt aga aca cta agt tgg tac ttt cta ttg tgt 605
Tyr Asp Leu Pro Trp Phe Arg Thr Leu Ser Trp Tyr Phe Leu Leu Cys
140 145 150
gta aac tac ttt ttc tat gga gag act gta gct gat tat ttt gct aca 653
Val Asn Tyr Phe Phe Tyr Gly Glu Thr Val Ala Asp Tyr Phe Ala Thr
155 160 165
ttt gtt caa aga gaa gaa caa ctt cag ttc ctc att cgc tac cat aga 701
Phe Val Gln Arg Glu Glu Gln Leu Gln Phe Leu Ile Arg Tyr His Arg
170 175 180
ttt ata tca ttt gcc ctc tat ctg gca ggt ttc tgc atg ttt gta ctg 749
Phe Ile Ser Phe Ala Leu Tyr Leu Ala Gly Phe Cys Met Phe Val Leu
185 190 195 200
agt ttg gtg aag gaa cat tat cgt ctg cag ttt tat atg ttc gca tgg 797
Ser Leu Val Lys Glu His Tyr Arg Leu Gln Phe Tyr Met Phe Ala Trp
205 210 215
act cat gtc act tta ctg ata act gtc act cag tca cac ctt gtc atc 845
Thr His Val Thr Leu Leu Ile Thr Val Thr Gln Ser His Leu Val Ile
220 225 230
caa aat ctg ttt gaa ggc atg ata tgg ttc ctt gtt cca ata tca agt 893
Gln Asn Leu Phe Glu Gly Met Ile Trp Phe Leu Val Pro Ile Ser Ser
235 240 245
gtt atc tgc aat gac ata act gct tac ctt ttt gga ttt ttt ttt ggg 941
Val Ile Cys Asn Asp Ile Thr Ala Tyr Leu Phe Gly Phe Phe Phe Gly
250 255 260
aga act cca tta att aag ttg tct cct aaa aag act tgg gaa gga ttc 989
Arg Thr Pro Leu Ile Lys Leu Ser Pro Lys Lys Thr Trp Glu Gly Phe
265 270 275 280
att ggt ggt ttc ttt tcc aca gtt gtg ttt gga ttc att gct gcc tat 1037
Ile Gly Gly Phe Phe Ser Thr Val Val Phe Gly Phe Ile Ala Ala Tyr
285 290 295
gtg tta tcc aaa tac cag tac ttt gtc tgc cca gtg gaa tac cga agt 1085
Val Leu Ser Lys Tyr Gln Tyr Phe Val Cys Pro Val Glu Tyr Arg Ser
300 305 310
gat gta aac tcc ttc gtg aca gaa tgt gag ccc tca gaa ctt ttc cag 1133
Asp Val Asn Ser Phe Val Thr Glu Cys Glu Pro Ser Glu Leu Phe Gln
315 320 325
ctt cag act tac tca ctt cca ccc ttt cta aag gca gtc ttg aga cag 1181
Leu Gln Thr Tyr Ser Leu Pro Pro Phe Leu Lys Ala Val Leu Arg Gln
330 335 340
gaa aga gtg agc ttg tac cct ttc cag atc cac agc att gca ctg tca 1229
Glu Arg Val Ser Leu Tyr Pro Phe Gln Ile His Ser Ile Ala Leu Ser
345 350 355 360
acc ttt gca tct tta att ggc cca ttt gga ggc ttc ttt gct agt gga 1277
Thr Phe Ala Ser Leu Ile Gly Pro Phe Gly Gly Phe Phe Ala Ser Gly
365 370 375
ttc aaa aga gcc ttc aaa atc aag gat ttt gca aat acc att cct gga 1325
Phe Lys Arg Ala Phe Lys Ile Lys Asp Phe Ala Asn Thr Ile Pro Gly
380 385 390
cat ggt ggg ata atg gac aga ttt gat tgt cag tat ttg atg gca act 1373
His Gly Gly Ile Met Asp Arg Phe Asp Cys Gln Tyr Leu Met Ala Thr
395 400 405
ttt gta cat gtg tac atc aca agt ttt ata agg ggc cca aat ccc agc 1421
Phe Val His Val Tyr Ile Thr Ser Phe Ile Arg Gly Pro Asn Pro Ser
410 415 420
aaa gtg cta cag cag ttg ttg gtg ctt caa cct gaa cag cag tta aat 1469
Lys Val Leu Gln Gln Leu Leu Val Leu Gln Pro Glu Gln Gln Leu Asn
425 430 435 440
ata tat aaa acc ctg aag act cat ctc att gag aaa gga atc cta caa 1517
Ile Tyr Lys Thr Leu Lys Thr His Leu Ile Glu Lys Gly Ile Leu Gln
445 450 455
ccc acc ttg aag gta taactggatc cagagaggga aggactgaca agaaggaatt 1572
Pro Thr Leu Lys Val
460
attcagaaaa acactgacag atgttttata aattgtacag aaaaatagtt aaaaatgcaa 1632
taggttgaag ttttggagat atgtttctct ctgaaattac tgtgaatatt taacaaacac 1692
ttacttgatc tatgttatga aataagtagc aaattgccag caaaatgtct tgtacctttt 1752
ctaaagtgta ttttctgatg tgaacttcct tccccttact tgctaggttt cataatttaa 1812
aagactggta tttaaaagag tcaaacacta taaaatgagt aagttgacga tgttttaaga 1872
ttgcacctgg cagtgtgcct ttttgcacaa atatttactt ttgcacttgg agctgctttt 1932
aattttagca aaatgtttta tgcaaggcac aataggaagt cagttctcct gcacttcctc 1992
ctcatgtagt ctggagtact ttctaaaggg cttagttgga tttaaaaaaa aaaaaaaaa 2051
2
461
PRT
Homo sapiens
2
Met Leu Glu Leu Arg His Arg Gly Ser Cys Pro Gly Pro Arg Glu Ala
1 5 10 15
Val Ser Pro Pro His Arg Glu Gly Glu Ala Ala Gly Gly Asp His Glu
20 25 30
Thr Glu Ser Thr Ser Asp Lys Glu Thr Asp Ile Asp Asp Arg Tyr Gly
35 40 45
Asp Leu Asp Ser Arg Thr Asp Ser Asp Ile Pro Glu Ile Pro Pro Ser
50 55 60
Ser Asp Arg Thr Pro Glu Ile Leu Lys Lys Ala Leu Ser Gly Leu Ser
65 70 75 80
Ser Arg Trp Lys Asn Trp Trp Ile Arg Gly Ile Leu Thr Leu Thr Met
85 90 95
Ile Ser Leu Phe Phe Leu Ile Ile Tyr Met Gly Ser Phe Met Leu Met
100 105 110
Leu Leu Val Leu Gly Ile Gln Val Lys Cys Phe His Glu Ile Ile Thr
115 120 125
Ile Gly Tyr Arg Val Tyr His Ser Tyr Asp Leu Pro Trp Phe Arg Thr
130 135 140
Leu Ser Trp Tyr Phe Leu Leu Cys Val Asn Tyr Phe Phe Tyr Gly Glu
145 150 155 160
Thr Val Ala Asp Tyr Phe Ala Thr Phe Val Gln Arg Glu Glu Gln Leu
165 170 175
Gln Phe Leu Ile Arg Tyr His Arg Phe Ile Ser Phe Ala Leu Tyr Leu
180 185 190
Ala Gly Phe Cys Met Phe Val Leu Ser Leu Val Lys Glu His Tyr Arg
195 200 205
Leu Gln Phe Tyr Met Phe Ala Trp Thr His Val Thr Leu Leu Ile Thr
210 215 220
Val Thr Gln Ser His Leu Val Ile Gln Asn Leu Phe Glu Gly Met Ile
225 230 235 240
Trp Phe Leu Val Pro Ile Ser Ser Val Ile Cys Asn Asp Ile Thr Ala
245 250 255
Tyr Leu Phe Gly Phe Phe Phe Gly Arg Thr Pro Leu Ile Lys Leu Ser
260 265 270
Pro Lys Lys Thr Trp Glu Gly Phe Ile Gly Gly Phe Phe Ser Thr Val
275 280 285
Val Phe Gly Phe Ile Ala Ala Tyr Val Leu Ser Lys Tyr Gln Tyr Phe
290 295 300
Val Cys Pro Val Glu Tyr Arg Ser Asp Val Asn Ser Phe Val Thr Glu
305 310 315 320
Cys Glu Pro Ser Glu Leu Phe Gln Leu Gln Thr Tyr Ser Leu Pro Pro
325 330 335
Phe Leu Lys Ala Val Leu Arg Gln Glu Arg Val Ser Leu Tyr Pro Phe
340 345 350
Gln Ile His Ser Ile Ala Leu Ser Thr Phe Ala Ser Leu Ile Gly Pro
355 360 365
Phe Gly Gly Phe Phe Ala Ser Gly Phe Lys Arg Ala Phe Lys Ile Lys
370 375 380
Asp Phe Ala Asn Thr Ile Pro Gly His Gly Gly Ile Met Asp Arg Phe
385 390 395 400
Asp Cys Gln Tyr Leu Met Ala Thr Phe Val His Val Tyr Ile Thr Ser
405 410 415
Phe Ile Arg Gly Pro Asn Pro Ser Lys Val Leu Gln Gln Leu Leu Val
420 425 430
Leu Gln Pro Glu Gln Gln Leu Asn Ile Tyr Lys Thr Leu Lys Thr His
435 440 445
Leu Ile Glu Lys Gly Ile Leu Gln Pro Thr Leu Lys Val
450 455 460
3
38
PRT
Drosophila
3
Lys Arg Ala Phe Lys Ile Lys Asp Phe Gly Asp Met Ile Pro Gly His
1 5 10 15
Gly Gly Ile Met Asp Arg Phe Asp Cys Gln Phe Leu Met Ala Thr Phe
20 25 30
Val Asn Val Tyr Ile Ser
35
4
38
PRT
Homo sapiens
4
Lys Arg Ala Phe Lys Ile Lys Asp Phe Ala Asn Thr Ile Pro Gly His
1 5 10 15
Gly Gly Ile Met Asp Arg Phe Asp Cys Gln Tyr Leu Met Ala Thr Phe
20 25 30
Val His Val Tyr Ile Thr
35
5
27
DNA
Artificial Sequence
Description of Artificial Sequence Synthetic
oligonucleotide
5
cccaccatgg ccaggaatgg tatttgc 27
6
25
DNA
Artificial Sequence
Description of Artificial Sequence Synthetic
oligonucleotide
6
agtgatgtga attccttcgt gacag 25
7
29
DNA
Artificial Sequence
Description of Artificial Sequence Primer
7
ggctctagat attaatagta atcaattac 29
8
26
DNA
Artificial Sequence
Description of Artificial Sequence Primer
8
cctcacgcat gcaccatggt aatagc 26
9
24
DNA
Artificial Sequence
Description of Artificial Sequence Primer
9
ggtgcatgcg tgaggctccg gtgc 24
10
28
DNA
Artificial Sequence
Description of Artificial Sequence Primer
10
gtagttttca cggtacctga aatggaag 28
11
2488
DNA
Homo sapiens
CDS
(25)..(1359)
11
cgacgtcggg ccgattttcc cagg atg aca gag ctg agg cag agg gtg gcc 51
Met Thr Glu Leu Arg Gln Arg Val Ala
1 5
cat gag ccg gtt gcg cca ccc gag gac aag gag tca gag tca gaa gca 99
His Glu Pro Val Ala Pro Pro Glu Asp Lys Glu Ser Glu Ser Glu Ala
10 15 20 25
aag gta gat gga gag act gca tcg gac agt gag agc cag gca gaa tcc 147
Lys Val Asp Gly Glu Thr Ala Ser Asp Ser Glu Ser Gln Ala Glu Ser
30 35 40
gca ccc ctg cca gtc tct gca gat gat acc ccg gag gtc ctc aat agg 195
Ala Pro Leu Pro Val Ser Ala Asp Asp Thr Pro Glu Val Leu Asn Arg
45 50 55
gcc ctt tcc aac ttg tct tca aga tgg aag gac tgg tgg gtg aga ggc 243
Ala Leu Ser Asn Leu Ser Ser Arg Trp Lys Asp Trp Trp Val Arg Gly
60 65 70
atc ctg act ttg gcc atg att gca ttt ttc ttc atc atc att tac ctg 291
Ile Leu Thr Leu Ala Met Ile Ala Phe Phe Phe Ile Ile Ile Tyr Leu
75 80 85
gga cca atg gtt ttg atg ata atc gtg atg tgc gtt cag att aag tgt 339
Gly Pro Met Val Leu Met Ile Ile Val Met Cys Val Gln Ile Lys Cys
90 95 100 105
ttc cat gag ata atc act att ggc tac aac gtc tac cac tca tat gat 387
Phe His Glu Ile Ile Thr Ile Gly Tyr Asn Val Tyr His Ser Tyr Asp
110 115 120
ctg ccc tgg ttc agg acg ctc agc tgg tac ttt ctc ctg tgt gta aac 435
Leu Pro Trp Phe Arg Thr Leu Ser Trp Tyr Phe Leu Leu Cys Val Asn
125 130 135
tat ttc ttc tat ggt gag aca gtg acg gat tac ttc ttc acc ctg gtc 483
Tyr Phe Phe Tyr Gly Glu Thr Val Thr Asp Tyr Phe Phe Thr Leu Val
140 145 150
cag aga gaa gag cct ttg cgg att ctc agt aaa tac cac cgg ttc att 531
Gln Arg Glu Glu Pro Leu Arg Ile Leu Ser Lys Tyr His Arg Phe Ile
155 160 165
tcc ttt act ctc tat cta ata gga ttc tgc atg ttt gta ctg agt ctg 579
Ser Phe Thr Leu Tyr Leu Ile Gly Phe Cys Met Phe Val Leu Ser Leu
170 175 180 185
gtc aag aag cat tat cga ctg cag ttc tac atg ttt ggc tgg acc cat 627
Val Lys Lys His Tyr Arg Leu Gln Phe Tyr Met Phe Gly Trp Thr His
190 195 200
gtg aca ttg ctg att gtt gta aca cag tca cat ctt gtt atc cac aac 675
Val Thr Leu Leu Ile Val Val Thr Gln Ser His Leu Val Ile His Asn
205 210 215
cta ttt gaa gga atg atc tgg ttc att gtc ccc ata tct tgt gtg atc 723
Leu Phe Glu Gly Met Ile Trp Phe Ile Val Pro Ile Ser Cys Val Ile
220 225 230
tgt aat gac atc atg gcc tat atg ttt ggc ttt ttc ttt ggt cgg acc 771
Cys Asn Asp Ile Met Ala Tyr Met Phe Gly Phe Phe Phe Gly Arg Thr
235 240 245
cca ctc atc aag ctg tcc ccg aag aag acc tgg gaa ggc ttc att ggg 819
Pro Leu Ile Lys Leu Ser Pro Lys Lys Thr Trp Glu Gly Phe Ile Gly
250 255 260 265
ggc ttc ttt gct act gtg gtg ttt ggc ctt ctg ctg tcc tat gtg atg 867
Gly Phe Phe Ala Thr Val Val Phe Gly Leu Leu Leu Ser Tyr Val Met
270 275 280
tcc ggg tac aga tgc ttt gtc tgc cct gtg gag tac aac aat gac acc 915
Ser Gly Tyr Arg Cys Phe Val Cys Pro Val Glu Tyr Asn Asn Asp Thr
285 290 295
aac agc ttc act gtg gac tgt gag ccc tcg gac ctg ttt cgc ctg cag 963
Asn Ser Phe Thr Val Asp Cys Glu Pro Ser Asp Leu Phe Arg Leu Gln
300 305 310
gag tac aac att cct ggg gtg atc cag tca gtc att ggc tgg aaa acg 1011
Glu Tyr Asn Ile Pro Gly Val Ile Gln Ser Val Ile Gly Trp Lys Thr
315 320 325
gtc cgg atg tac ccc ttc cag att cac agc atc gct ctc tcc acc ttt 1059
Val Arg Met Tyr Pro Phe Gln Ile His Ser Ile Ala Leu Ser Thr Phe
330 335 340 345
gcc tcg ctc att ggc ccc ttt gga gga ttc ttc gca agt gga ttc aaa 1107
Ala Ser Leu Ile Gly Pro Phe Gly Gly Phe Phe Ala Ser Gly Phe Lys
350 355 360
cga gcc ttt aaa atc aaa gac ttt gcc aat acc att cct ggc cat gga 1155
Arg Ala Phe Lys Ile Lys Asp Phe Ala Asn Thr Ile Pro Gly His Gly
365 370 375
ggc atc atg gat cgc ttt gac tgc cag tat ctg atg gcc acc ttt gtc 1203
Gly Ile Met Asp Arg Phe Asp Cys Gln Tyr Leu Met Ala Thr Phe Val
380 385 390
aat gta tac atc gcc agt ttt atc aga ggc cct aac cca agc aaa ctg 1251
Asn Val Tyr Ile Ala Ser Phe Ile Arg Gly Pro Asn Pro Ser Lys Leu
395 400 405
att cag cag ttc ctg act tta cgg cca gat cag cag ctc cac atc ttc 1299
Ile Gln Gln Phe Leu Thr Leu Arg Pro Asp Gln Gln Leu His Ile Phe
410 415 420 425
aac acg ctg cgg tct cat ctg atc gac aaa ggg atg ctg aca tcc acc 1347
Asn Thr Leu Arg Ser His Leu Ile Asp Lys Gly Met Leu Thr Ser Thr
430 435 440
aca gag gac gag taggggccac ccagggccag gagaacagga acagaactga 1399
Thr Glu Asp Glu
445
gcaggggcag gtctccaagg caagcccagc tggtgtgact tagacaatga cgaggcttca 1459
actcactgtc tttttttttt tttttttttt ggagggtatt ttttatttgt gggttcaaaa 1519
aatctgtata tacagtctat gtgtttagaa tttgtgttgt aagtaaacta cagctttgag 1579
ttggaaagaa gtcacgggtt gtaaaaccat ttggattttt ttaaaacaaa agtattaata 1639
atctggaaga cagtgttgcc caggtcagga gtgttttctt ggtggttcca gcccccatca 1699
attgaactgt ttctgggctc agtcagacac agacattcat ctgtgtctga ccaaatcagg 1759
ggacttcccc acctgtggtg ggaggcacag cttagatgtt ttgtacacct ggtcttttct 1819
agaaatccct gcttggagct gcagaagggt tgccttctgt aggtcggagg aatggaggct 1879
tactaaccag gtaagccttc tatgcatcca caccaaaatc ctgcagaatg taagtaagct 1939
ctgctttata agatgggttc accttcatcg cagactgaaa gtttcagttt ttattttttt 1999
cagaaagcac gaaaaattat ttataatagt ctggagaaaa aacacactgt aatatttcaa 2059
gtgtatgcag tagaatgtac tgtaactgag ccctttccca catgtctagg ctccaatgtc 2119
tcctgtaggt ccacctaact gtgtgttttc agggacaatg ccatccatgt ttgtgctgta 2179
gacttgctgc tgctgaatcc tttctgggga ctttctcatc gggcagggag cagagggctt 2239
ctcgttcatg caccctttgc ctgaacaccc atgtagctgc tgtgttgtgt atatattact 2299
cttaagagga gtgtgtgtgt ctgtgtttgt tttaaaagtc acttatttct tacagtgatt 2359
tcaattgcac catgacttct tcactaaaac cacaaagtcc tgcttaaaac tatggaaaac 2419
ctaacctgat tagagccttg actattttga agattaaatg cacacttttt atataaaaaa 2479
aaaaaaaaa 2488
12
445
PRT
Homo sapiens
12
Met Thr Glu Leu Arg Gln Arg Val Ala His Glu Pro Val Ala Pro Pro
1 5 10 15
Glu Asp Lys Glu Ser Glu Ser Glu Ala Lys Val Asp Gly Glu Thr Ala
20 25 30
Ser Asp Ser Glu Ser Gln Ala Glu Ser Ala Pro Leu Pro Val Ser Ala
35 40 45
Asp Asp Thr Pro Glu Val Leu Asn Arg Ala Leu Ser Asn Leu Ser Ser
50 55 60
Arg Trp Lys Asp Trp Trp Val Arg Gly Ile Leu Thr Leu Ala Met Ile
65 70 75 80
Ala Phe Phe Phe Ile Ile Ile Tyr Leu Gly Pro Met Val Leu Met Ile
85 90 95
Ile Val Met Cys Val Gln Ile Lys Cys Phe His Glu Ile Ile Thr Ile
100 105 110
Gly Tyr Asn Val Tyr His Ser Tyr Asp Leu Pro Trp Phe Arg Thr Leu
115 120 125
Ser Trp Tyr Phe Leu Leu Cys Val Asn Tyr Phe Phe Tyr Gly Glu Thr
130 135 140
Val Thr Asp Tyr Phe Phe Thr Leu Val Gln Arg Glu Glu Pro Leu Arg
145 150 155 160
Ile Leu Ser Lys Tyr His Arg Phe Ile Ser Phe Thr Leu Tyr Leu Ile
165 170 175
Gly Phe Cys Met Phe Val Leu Ser Leu Val Lys Lys His Tyr Arg Leu
180 185 190
Gln Phe Tyr Met Phe Gly Trp Thr His Val Thr Leu Leu Ile Val Val
195 200 205
Thr Gln Ser His Leu Val Ile His Asn Leu Phe Glu Gly Met Ile Trp
210 215 220
Phe Ile Val Pro Ile Ser Cys Val Ile Cys Asn Asp Ile Met Ala Tyr
225 230 235 240
Met Phe Gly Phe Phe Phe Gly Arg Thr Pro Leu Ile Lys Leu Ser Pro
245 250 255
Lys Lys Thr Trp Glu Gly Phe Ile Gly Gly Phe Phe Ala Thr Val Val
260 265 270
Phe Gly Leu Leu Leu Ser Tyr Val Met Ser Gly Tyr Arg Cys Phe Val
275 280 285
Cys Pro Val Glu Tyr Asn Asn Asp Thr Asn Ser Phe Thr Val Asp Cys
290 295 300
Glu Pro Ser Asp Leu Phe Arg Leu Gln Glu Tyr Asn Ile Pro Gly Val
305 310 315 320
Ile Gln Ser Val Ile Gly Trp Lys Thr Val Arg Met Tyr Pro Phe Gln
325 330 335
Ile His Ser Ile Ala Leu Ser Thr Phe Ala Ser Leu Ile Gly Pro Phe
340 345 350
Gly Gly Phe Phe Ala Ser Gly Phe Lys Arg Ala Phe Lys Ile Lys Asp
355 360 365
Phe Ala Asn Thr Ile Pro Gly His Gly Gly Ile Met Asp Arg Phe Asp
370 375 380
Cys Gln Tyr Leu Met Ala Thr Phe Val Asn Val Tyr Ile Ala Ser Phe
385 390 395 400
Ile Arg Gly Pro Asn Pro Ser Lys Leu Ile Gln Gln Phe Leu Thr Leu
405 410 415
Arg Pro Asp Gln Gln Leu His Ile Phe Asn Thr Leu Arg Ser His Leu
420 425 430
Ile Asp Lys Gly Met Leu Thr Ser Thr Thr Glu Asp Glu
435 440 445
13
2103
DNA
Homo sapiens
13
tctatggtgg ggccgcgtta gtggctgcgg ctccgcggga ctccagggcg cggctgcgag 60
gtggcggggc gccccgcctg cagaaccctg cttgcagctc aggtttcggg gtgcttgagg 120
aggccgccac ggcagcgcgg gagcggaaga tgttggagct gaggcaccgg ggaagctgcc 180
ccggccccag ggaagcggtg tcgccgccac accgcgaggg agaggcggcc ggcggcgacc 240
acgaaaccga gagcaccagc gacaaagaaa cagatattga tgacagatat ggagatttgg 300
attccagaac agattctgat attccggaaa ttccaccatc ctcagataga acccctgaga 360
ttctcaaaaa agctctatct ggtttatctt caaggtggaa aaactggtgg atacgtggaa 420
ttctcactct aactatgatc tcgttgtttt tcctgatcat ctatatggga tccttcatgc 480
tgatgcttct tgttctgggc atccaagtga aatgcttcca tgaaattatc actataggtt 540
atagagtcta tcattcttat gatctaccat ggtttagaac actaagttgg tactttctat 600
tgtgtgtaaa ctactttttc tatggagaga ctgtagctga ttattttgct acatttgttc 660
aaagagaaga acaacttcag ttcctcattc gctaccatag atttatatca tttgccctct 720
atctggcagg tttctgcatg tttgtactga gtttggtgaa ggaacattat cgtctgcagt 780
tttatatgtt cgcatggact catgtcactt tactgataac tgtcactcag tcacaccttg 840
tcatccaaaa tctgtttgaa ggcatgatat ggttccttgt tccaatatca agtgttatct 900
gcaatgacat aactgcttac ctttttggat ttttttttgg gagaactcca ttaattaagt 960
tgtctcctaa aaagacttgg gaaggattca ttggtggttt cttttccaca gttgtgtttg 1020
gattcattgc tgcctatgtg ttatccaaat accagtactt tgtctgccca gtggaatacc 1080
gaagtgatgt aaactccttc gtgacagaat gtgagccctc agaacttttc cagcttcaga 1140
cttactcact tccacccttt ctaaaggcag tcttgagaca ggaaagagtg agcttgtacc 1200
ctttccagat ccacagcatt gcactgtcaa cctttgcatc tttaattggc ccatttggag 1260
gcttctttgc tagtggattc aaaagagcct tcaaaatcaa ggattttgca aataccattc 1320
ctggacatgg tgggataatg gacagatttg attgtcagta tttgatggca acttttgtac 1380
atgtgtacat cacaagtttt ataaggggcc caaatcccag caaagtgcta cagcagttgt 1440
tggtgcttca acctgaacag cagttaaata tatataaaac cctgaagact catctcattg 1500
agaaaggaat cctacaaccc accttgaagg tataactgga tccagagagg gaaggactga 1560
caagaaggaa ttattcagaa aaacactgac agatgtttta taaattgtac agaaaaatag 1620
ttaaaaatgc aataggttga agttttggag atatgtttct ctctgaaatt actgtgaata 1680
tttaacaaac acttacttga tctatgttat gaaataagta gcaaattgcc agcaaaatgt 1740
cttgtacctt ttctaaagtg tattttctga tgtgaacttc cttcccctta cttgctaggt 1800
ttcataattt aaaagactgg tatttaaaag agtcaaacac tataaaatga gtaagttgac 1860
gatgttttaa gattgcacct ggcagtgtgc ctttttgcac aaatatttac ttttgcactt 1920
ggagctgctt ttaattttag caaaatgttt tatgcaaggc acaataggaa gtcagttctc 1980
ctgcacttcc tcctcatgta gtctggagta ctttctaaag ggcttagttg gatttaaaaa 2040
aaaaaaaaaa agggcggccg ctctagagga tccctcgagg ggcccaagct tacgcgtgca 2100
tgc 2103
14
45
PRT
Homo sapiens
14
Gln Ser His Leu Val Ile His Asn Leu Phe Glu Gly Met Ile Trp Phe
1 5 10 15
Ile Val Pro Ile Ser Cys Val Ile Cys Asn Asp Ile Met Ala Tyr Met
20 25 30
Phe Gly Phe Phe Phe Gly Arg Thr Pro Leu Ile Lys Leu
35 40 45
15
22
DNA
Artificial Sequence
Description of Artificial Sequence Synthetic
oligonucleotide
15
aggacgcata tgagtggtag ac 22
16
21
DNA
Artificial Sequence
Description of Artificial Sequence Primer
16
gactctagcc taggcttttg c 21
17
249
PRT
E. coli
17
Met Leu Ala Ala Trp Glu Trp Gly Gln Leu Ser Gly Phe Thr Thr Arg
1 5 10 15
Ser Gln Arg Val Trp Leu Ala Val Leu Cys Gly Leu Leu Leu Ala Leu
20 25 30
Met Leu Phe Leu Leu Pro Glu Tyr His Arg Asn Ile His Gln Pro Leu
35 40 45
Val Glu Ile Ser Leu Trp Ala Ser Leu Gly Trp Trp Ile Val Ala Leu
50 55 60
Leu Leu Val Leu Phe Tyr Pro Gly Ser Ala Ala Ile Trp Arg Asn Ser
65 70 75 80
Lys Thr Leu Arg Leu Ile Phe Gly Val Leu Thr Ile Val Pro Phe Phe
85 90 95
Trp Gly Met Leu Ala Leu Arg Ala Trp His Tyr Asp Glu Asn His Tyr
100 105 110
Ser Gly Ala Ile Trp Leu Leu Tyr Val Met Ile Leu Val Trp Gly Ala
115 120 125
Asp Ser Gly Ala Tyr Met Phe Gly Lys Leu Phe Gly Lys His Lys Leu
130 135 140
Ala Pro Lys Val Ser Pro Gly Lys Thr Trp Gln Gly Phe Ile Gly Gly
145 150 155 160
Leu Ala Thr Ala Ala Val Ile Ser Trp Gly Tyr Gly Met Trp Ala Asn
165 170 175
Leu Asp Val Ala Pro Val Thr Leu Leu Ile Cys Ser Ile Val Ala Ala
180 185 190
Leu Ala Ser Val Leu Gly Asp Leu Thr Glu Ser Met Phe Lys Arg Glu
195 200 205
Ala Gly Ile Lys Asp Ser Gly His Leu Ile Pro Gly His Gly Gly Ile
210 215 220
Leu Asp Arg Ile Asp Ser Leu Thr Ala Ala Val Pro Val Phe Ala Cys
225 230 235 240
Leu Leu Leu Leu Val Phe Arg Thr Leu
245
18
457
PRT
Yeast
18
Met Ser Asp Asn Pro Glu Met Lys Pro His Gly Thr Ser Lys Glu Ile
1 5 10 15
Val Glu Ser Val Thr Asp Ala Thr Ser Lys Ala Ile Asp Lys Leu Gln
20 25 30
Glu Glu Leu His Lys Asp Ala Ser Glu Ser Val Thr Pro Val Thr Lys
35 40 45
Glu Ser Thr Ala Ala Thr Lys Glu Ser Arg Lys Tyr Asn Phe Phe Ile
50 55 60
Arg Thr Val Trp Thr Phe Val Met Ile Ser Gly Phe Phe Ile Thr Leu
65 70 75 80
Ala Ser Gly His Ala Trp Cys Ile Val Leu Ile Leu Gly Cys Gln Ile
85 90 95
Ala Thr Phe Lys Glu Cys Ile Ala Val Thr Ser Ala Ser Gly Arg Glu
100 105 110
Lys Asn Leu Pro Leu Thr Lys Thr Leu Asn Trp Tyr Leu Leu Phe Thr
115 120 125
Thr Ile Tyr Tyr Leu Asp Gly Lys Ser Leu Phe Lys Phe Phe Gln Ala
130 135 140
Thr Phe Tyr Glu Tyr Pro Val Leu Asn Phe Ile Val Thr Asn His Lys
145 150 155 160
Phe Ile Cys Tyr Cys Leu Tyr Leu Met Gly Phe Val Leu Phe Val Cys
165 170 175
Ser Leu Arg Lys Gly Phe Leu Lys Phe Gln Phe Gly Ser Leu Cys Val
180 185 190
Thr His Met Val Leu Leu Leu Val Val Phe Gln Ala His Leu Ile Ile
195 200 205
Lys Asn Val Leu Asn Gly Leu Phe Trp Phe Leu Leu Pro Cys Gly Leu
210 215 220
Val Ile Val Asn Asp Ile Phe Ala Tyr Leu Cys Gly Ile Thr Phe Gly
225 230 235 240
Lys Thr Lys Leu Ile Glu Ile Ser Pro Lys Lys Thr Leu Glu Gly Phe
245 250 255
Leu Gly Ala Trp Phe Phe Thr Ala Leu Ala Ser Ile Ile Leu Thr Arg
260 265 270
Ile Leu Ser Pro Tyr Thr Tyr Leu Thr Cys Pro Val Glu Asp Leu His
275 280 285
Thr Asn Phe Phe Ser Asn Leu Thr Cys Glu Leu Asn Pro Val Phe Leu
290 295 300
Pro Gln Val Tyr Arg Leu Pro Pro Ile Phe Phe Asp Lys Val Gln Ile
305 310 315 320
Asn Ser Ile Thr Val Lys Pro Ile Tyr Phe His Ala Leu Asn Leu Ala
325 330 335
Thr Phe Ala Ser Leu Phe Ala Pro Phe Gly Gly Phe Phe Ala Ser Gly
340 345 350
Leu Lys Arg Thr Phe Lys Val Lys Asp Phe Gly His Ser Ile Pro Gly
355 360 365
His Gly Gly Ile Thr Asp Arg Val Asp Cys Gln Phe Ile Met Gly Ser
370 375 380
Phe Ala Asn Leu Tyr Tyr Glu Thr Phe Ile Ser Glu His Arg Ile Thr
385 390 395 400
Val Asp Thr Val Leu Ser Thr Ile Leu Met Asn Leu Asn Asp Lys Gln
405 410 415
Ile Ile Glu Leu Ile Asp Ile Leu Ile Arg Phe Leu Ser Lys Lys Gly
420 425 430
Ile Ile Ser Ala Lys Asn Phe Glu Lys Leu Ala Asp Ile Phe Asn Val
435 440 445
Thr Lys Lys Ser Leu Thr Asn His Ser
450 455
19
446
PRT
Drosophila
19
Met Ala Glu Val Arg Arg Arg Lys Gly Glu Asp Glu Pro Leu Glu Asp
1 5 10 15
Thr Ala Ile Ser Gly Ser Asp Ala Ala Asn Lys Arg Asn Ser Ala Ala
20 25 30
Asp Ser Ser Asp His Val Asp Ser Glu Glu Glu Lys Ile Pro Glu Glu
35 40 45
Lys Phe Val Asp Glu Leu Ala Lys Asn Leu Pro Gln Gly Thr Asp Lys
50 55 60
Thr Pro Glu Ile Leu Asp Ser Ala Leu Lys Asp Leu Pro Asp Arg Trp
65 70 75 80
Lys Asn Trp Val Ile Arg Gly Ile Phe Thr Trp Ile Met Ile Cys Gly
85 90 95
Phe Ala Leu Ile Ile Tyr Gly Gly Pro Leu Ala Leu Met Ile Thr Thr
100 105 110
Leu Leu Val Gln Val Lys Cys Phe Gln Glu Ile Ile Ser Ile Gly Tyr
115 120 125
Gln Val Tyr Arg Ile His Gly Leu Pro Trp Phe Arg Ser Leu Ser Trp
130 135 140
Tyr Phe Leu Leu Thr Ser Asn Tyr Phe Phe Tyr Gly Glu Asn Leu Val
145 150 155 160
Asp Tyr Phe Gly Val Val Ile Asn Arg Val Glu Tyr Leu Lys Phe Leu
165 170 175
Val Thr Tyr His Arg Phe Leu Ser Phe Ala Leu Tyr Ile Ile Gly Phe
180 185 190
Val Trp Phe Val Leu Ser Leu Val Lys Lys Tyr Tyr Ile Lys Gln Phe
195 200 205
Ser Leu Phe Ala Trp Thr His Val Ser Leu Leu Ile Val Val Thr Gln
210 215 220
Ser Tyr Leu Ile Ile Gln Asn Ile Phe Glu Gly Leu Ile Trp Phe Ile
225 230 235 240
Val Pro Val Ser Met Ile Val Cys Asn Asp Val Met Ala Tyr Val Phe
245 250 255
Gly Phe Phe Phe Gly Arg Thr Pro Leu Ile Lys Leu Ser Pro Lys Lys
260 265 270
Thr Trp Glu Gly Phe Ile Gly Gly Gly Phe Ala Thr Val Leu Phe Gly
275 280 285
Ile Leu Phe Ser Tyr Val Leu Cys Asn Tyr Gln Tyr Phe Ile Cys Pro
290 295 300
Ile Gln Tyr Ser Glu Glu Gln Gly Arg Met Thr Met Ser Cys Val Pro
305 310 315 320
Ser Tyr Leu Phe Thr Pro Gln Glu Tyr Ser Leu Lys Leu Phe Gly Ile
325 330 335
Gly Lys Thr Leu Asn Leu Tyr Pro Phe Ile Trp His Ser Ile Ser Leu
340 345 350
Ser Leu Phe Ser Ser Ile Ile Gly Pro Phe Gly Gly Phe Phe Ala Ser
355 360 365
Gly Phe Lys Arg Ala Phe Lys Ile Lys Asp Phe Gly Asp Met Ile Pro
370 375 380
Gly His Gly Gly Ile Met Asp Arg Phe Asp Cys Gln Phe Leu Met Ala
385 390 395 400
Thr Phe Val Asn Val Tyr Ile Ser Phe Ile Arg Thr Pro Ser Pro Ala
405 410 415
Lys Leu Leu Thr Gln Ile Tyr Asn Leu Lys Pro Asp Gln Gln Tyr Gln
420 425 430
Ile Tyr Gln Ser Leu Lys Asp Asn Leu Gly His Met Leu Thr
435 440 445
|
There is disclosed cDNA sequences and polypeptides having the enzyme CDP-diacylglycerol synthase (CDS) activity. CDS is also known as CTP:phosphatidate cytidylyltransferase. There is further disclosed methods for isolation and production of polypeptides involved in phosphatidic acid metabolism and signaling in mammalian cells, in particular, the production of purified forms of CDS.
| 2
|
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to an improved combination belt and pulley used in a belt drive mechanism.
2. Description of the Prior Art
So called V-belts and multiple groove belts have heretofore been employed in conjunction with pulleys for power transmission purposes. One such V-belt pulley is disclosed in U.S. Pat. No. 3,225,614. In many cases the belts are not of V-section but are of trapezoidal section, and have a number of ribs across the contacting surface of the belt which are seated in and engage grooves in the pulley. Such a multiple rib belt and pulley arrangement is disclosed in U.S. Pat. No. 2,728,239. These belt and pulley mechanisms have been used for driving the rotatable horizontal axis drum of laundry machines such as automatic clothes dryers. The pulley is of small diameter and driven by an electric motor with the belt wrapping around the clothes dryer drum which is substantially larger in diameter than the pulley so that the drum is driven at a speed much slower than the drive pulley. Multiple groove or poly-V-belts, as they are often called, have been utilized for this purpose as they have been found to perform quite well with a minimum of slippage due to the poly-V configuration and mating of the spool of the pulley. Because the pulley is quite small in diameter relative to the drum, good traction between the belt and pulley is needed for power transmission. Moreover, the use of poly-V belts result in a belt of smaller overall dimensions for a predetermined power capacity.
One of the difficulties, however, in the utilization of a poly-V belt and pulley mechanism is that during the assembly of the mechanism there may be misalignment of the belt ribs to the drive pulley grooves. When this occurs the operation of the belt and pulley mechanism is detrimentally affected by the additional stress on some of the ribs which in turn reduces the belt life and induces a change in the speed of the driven item, such as the clothes dryer drum. In addition, such misalignment condition can cause the belt to actually come off the pulley and make the drive mechanism inoperative.
It is desirable to be able to have a poly-V belt and drive pulley mechanism that will automatically compensate for any misalignment of the belt ribs in the proper mating pulley groove and in addition prevent the belt from coming off of the pulley should there be any such misalignment.
SUMMARY OF THE INVENTION
There is provided a mechanism including the combination of a rib-and-groove tractive face belt for service as a transmission belt, conveyor belt or the like, and a rib-and-groove pulley over which the belt is trained. The pulley has a spool with grooves and ribs to correspond and to mate with the rib-and-groove tractive surface of the belt and upwardly and outwardly diverging opposing side walls each being curved convexly.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a partially cut away perspective of a laundry machine showing the arrangement of the various machine components and including the poly-V belt and pulley mechanism.
FIG. 2 is an enlarged side plan view of the poly-V belt and pulley mechanism partially in cross section.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is illustrated a laundry machine 10 including an appearance and protective outer cabinet 12 having an access door 14 which is hingedly secured to the front wall of the cabinet 12. Within cabinet 12 there is provided a clothes tumbling container or drum 16 mounted for rotation about a horizontal central axis. Drum 16 is cylindrical in shape and has a cylindrical side wall 18, a rear circular wall portion 20 secured to the cylindrical side wall 18 as by a crimped flange generally shown around the periphery of the circular wall portion 20 as 21. The front drum portion is a circular member (not shown) that may be secured to the cylindrical side wall 18 by a crimped flange 23 and has an opening in communication with an access opening through the cabinet 12 which is covered by access door 14.
Such laundry machines are provided with an automatic control so that the operator by manually setting the control and actuating a second means causes the machine to start and automatically proceed through a desired cycle operation. In some cases the laundry machine may simply dry clothes while in others it may be a combination washer-dryer machine which will include washing, extraction and drying operations. Both types of laundry machines may utilize this invention as they have a horizontal axis type drum driven by a poly-V belt and pulley mechanism.
The drum 16 is rotatably supported within the cabinet 12 at the rear thereof by a central stub bearing axle assembly 26 that supports the drum at the center of the rear circular wall 20. The front of the drum 16 is rotatably supported on a large circular component 30 which has an access opening at the front of the drum. The forward end of cylindrical side wall 18 rests on two slide members (not shown) each located on the large circular component 30 to slidably support the front portion of the drum 16. In this manner then the drum may be rotated and is supported in its proper position within cabinet 12 at the front by the slide members and at the rear by central stub bearing assembly 26.
There is provided within the laundry machine an electric motor 32 for driving the driven components of the machine. The motor shaft extending toward the front of the machine, as shown in the drawings, is connected to a wheel in a blower 34 for causing the air to flow through the system within the machine. Air is drawn from the interior of the drum 16 through duct 35 to blower 34. Air leaving the blower 34 may be expelled from the machine through an air conduit 36 that projects through an opening 38 in the rear wall 40 of cabinet 12. Alternatively, the air which is moisture laden may be directed through a condenser unit (not shown) within the machine wherein the moisture is removed from the air and the air then recirculated back through the system.
The motor shaft extending toward the rear of the machine has secured to it a belt pulley 42 for driving an endless belt 44 which wraps around the cylindrical side wall 18 of the drum 16 so that the electric motor through the belt pulley and belt cause the drum 16 to be rotated. To take up any slack in the belt 44 there is a belt tension assembly 46 provided and may be secured to the base 48 of cabinet 12.
With reference to FIG. 2, the details of the combination belt and pulley mechanism is shown in an enlarged view. An endless, flexible poly-V belt 44 is trained over pulley 42. The working face of the poly-V belt carries a plurality of adjacent V-sectioned ribs 50 with grooves 51 therebetween and has a top portion 52 which is flat. The ribs 50 and grooves 51 being parallel to each other and extending over the continuous tractive face of the belt 44. Such belts are made of an elastomeric material, such as neoprene, and may include cords for strengthening. The pulley 42 has a spool 53 with a plurality of annular grooves 54 and ribs 55 therebetween. The grooves 51 are so shaped and so dimensioned as to receive the belt ribs 50. In the embodiment shown in the drawings the belt ribs 50 and grooves 51 in the pulley spool have no clearance space and interfit with each other when the belt is in contact with the pulley spool. In some cases of poly-V belt and pulley mechanisms there is a clearance between the belt ribs and the pulley grooves and this invention works with that type of mechanism also. It should also be noted that the cross sectional shape of the belt may vary and the shape of the ribs in cross section may also be varied within this invention.
To retain the belt 44 on the pulley 42 there is provided opposing pulley side walls 56a and 56b which extend upwardly and outwardly from the spool 53 of pulley 42. The side walls 56a and 56b normally extend a greater distance from the spool of the pulley than the thickness of the belt 44 as can readily be seen in FIG. 2. Heretofore, it was common practice for the opposing side walls of pulleys to diverge upwardly and outwardly and be straight sided. In my invention the opposing side walls diverge upwardly and outwardly but are convexly shaped. That is, each opposing side wall of 56a and 56b of the pulley is curved upwardly and outwardly from the spool 53 of pulley 42. The convexly shaped side walls are formed by machining or any other suitable forming operation to conform to a curvature generated by a radius which is designated "R" in FIG. 2, the center point "P" of the radius being located on the axis 58 of the pulley. While the radius to provide the upwardly and outwardly convexly shaped side walls 56a and 56b may be varied depending upon the application or mechanism in which it is employed, I have found that a radius R of approximately 0.300 inches has performed quite satisfactorily relative to a belt having a width of 5/16 inches.
By providing the upwardly and outwardly convexly shaped side walls 56a and 56b in pulley 42, should there be any misalignment of the belt ribs 50 in pulley spool grooves 54, rotation of the pulley automatically shifts the belt 44 laterally with respect to the pulley spool 53 and causes the ribs 50 of the belt and grooves 54 of the spool to be aligned properly. Because of the small dimensions of the belt and pulley and particularly the ribs 50 of the belt and grooves 54 of the spool it is difficult for them to be aligned properly during assembly of the mechanism. As a result the misalignment will produce in many cases premature destruction of the belt, inefficient operation of the belt and pulley mechanism, and the belt can even come off the pulley. All of these increase repair maintenance necessary to correct the condition. By this invention the poly-V belt is self aligning and therefore minimizes or eliminates these problems.
The foregoing is a description of the preferred embodiment of the invention and variations may be made thereto without departing from the true spirit of the invention, as defined in the appended claims.
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A poly-V-belt and pulley mechanism including a rib-and-groove tractive face belt for service as a transmission belt, conveyor belt or the like, and a pulley over which the belt is trained. The pulley has a spool with grooves and ribs to correspond to and mate with the rib-and-groove tractive surface of the belt and upwardly and outwardly diverging opposing side walls, each being curved convexly. This poly-V-belt and pulley mechanism provides for self-alignment of the ribs of the belt in the grooves of the pulley.
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FIELD OF THE INVENTION
The present invention relates to a method for the production of packing for stuffing boxes, including a step in which the elementary yarns are braided to form the packing at an assembly point.
BACKGROUND INFORMATION
It is known that packings produced by the method specified above are wound around pump shafts or valve rods within a stuffing box to reduce or eliminate liquid losses. The packing thus arranged is compressed by a gland with a predetermined force so that it presses against the surface of the shaft or rod.
As a result of the curvature imposed by the winding, the elementary yarns on the extrados surface of the packing are in traction while the elementary yarns on the intrados surface are compressed so that the cross-section of the packing, which initially is square or rectangular, deforms into an isosceles trapezium with its larger base on the intrados side.
As a result of this deformation, the compressive force is not transmitted uniformly through the packing. Thus it is necessary to increase the force to achieve adequate hydraulic sealing at the expense of greater wear of the packing itself due to yielding and friction.
WO-A-94/11555 discloses a packing which has a cross-section in the form of an isosceles trapezium with its larger base on the extrados side. The deformation induced by the winding makes the section square or rectangular, improving the uniformity of transmission of the compressive forces.
The elementary yarns in such a packing are however subject to yielding as in conventional packing and are, in any case, under traction and compression. Moreover, in pumps, the friction is increased since the elementary yarns on the intrados surface are pressed together by the overlying yarns and pressed onto the surface of the shaft with a consequent loss of energy and overheating of the packing.
SUMMARY OF THE INVENTION
The technical problem which is at the root of the present invention is to provide a method for the production of packing for stuffing boxes, which packing is able to avoid the problems mentioned with reference to the prior art.
This problem is solved by a method of the type specified which is characterised in that it includes a step of winding the packing starting at the assembly point.
The main advantage of the method of the invention lies in the fact that packing is obtained which enables compressive forces to be transmitted uniformly through adjacent turns while at the same time eliminating forces within the packing.
BRIEF DESCRIPTION OF THE DRAWINGS
Further characteristics and advantages will become clear from the description of one preferred embodiment of the method of the invention, given below by way of non-limitative example, with reference to a machine for carrying out the said method and packing formed as illustrated in the appended drawings, in which:
FIG. 1 is a schematic perspective view of a machine for carrying out the method for the production of packing for stuffing boxes according to the invention;
FIG. 2 is a perspective view of a detail of the machine of FIG. 1;
FIG. 3 is a cross-section of the detail of FIG. 2;
FIG. 4 is a close-up perspective view of the step in which packing is braided in the machine of FIG. 1;
FIG. 5 is an enlarged perspective view of packing formed by the method for the production of packing for stuffing boxes according to the invention;
FIG. 6 is a perspective view of a portion of the packing of FIG. 5 in a rest condition; and
FIG. 7 is a sectional view of the packing of FIG. 5 within a stuffing box.
DETAILED DESCRIPTION
With reference to FIG. 1, a machine for the production of packing for stuffing boxes by means of the method for the production of packing for stuffing boxes according to the invention is indicated 1.
The machine 1 includes a frame 2, a horizontal thread guide plate 3 supported by the frame 2, a plurality of reels 4 of elementary yarns 5 rotatably engaged on respective fixed pins 6 of the frame 2 beneath the thread guide plate 3.
The thread guide plate 3 has a plurality of thread guide tubes 7 corresponding to the plurality of reels 4, the thread guide tubes extending perpendicular to the plate 3 and passing therethrough. In this embodiment there are seventeen thread guide tubes 7 arranged in a square with four tubes per side plus a tube in the central position.
The elementary yarn 5 of each reel 4 passes through the respective tube 7 and is termed conventionally a core yarn. Above the thread guide plate 3, each core yarn is maintained at a predetermined position relative to the other core yarns and is indicated 5a.
The thread guide plate 3 has a plurality of diagonal paths 8 located in its upper surface and arranged so as to surround each of the thread guide tubes 7.
The machine 1 further includes a plurality of movable elements 9 which are driven to move along the diagonal paths 8 by drive means housed within the thread guide plate 3 but not shown since they are conventional, there being a corresponding plurality of spools 10 of elementary yarns 5 rotatably engaged on the movable elements 9, each of which has a vertical rod 11 with a ring 12 at its upper end at a height above that of the ends of the thread guide tubes 7.
FIG. 1 shows only one movable element 9 for each diagonal path 8 when, in reality, the machine 1 includes several, for example four, movable elements 9 for each diagonal path 8.
The movement of the movable elements 9 is arranged so that they travel at the same speed, at a constant distance apart on each path 8 so that the movable elements 9 never touch each other.
The elementary yarn 5 of each spool 10 passes through the respective ring 12 and is conventionally termed a strand. Above the thread guide plate 3, the strands are braided with the core yarns 5a and are indicated 5b.
All the core yarns 5a and the strands 5b coming from the reels 4 and spools 10 respectively converge to an assembly point P above the centre of the thread guide plate 3 where they are braided to form a packing 14.
The assembly point P is located on the surface 15' of a horizontal roll 15 of the machine 1, the roll having a diameter D and being rotated by a motor 16. The roll 15 and the motor 16 are supported by a pair of uprights 17.
As a result of the rotation of the roll 15, the packing 14 forms a coil 18 on the surface 15' from which it is drawn by a draw and packaging assembly not shown since it is conventional.
The method of the invention includes a braiding step in which the elementary yarns 5 are braided to form the packing 14 at the assembly point P and a winding step in which the packing 14 is wound starting from the assembly point P into a coil.
In the machine 1 described above, the braiding step is effected, in an entirely conventional manner, by the movement of the movable elements 9 which causes the strands 5b to interlace with the core yarns 5a coming from the reels 4 and by the simultaneous traction exerted by the forced rotation of the roll 15 both on the strands 5b and on the core yarns 5a which unwind respectively from the spools 10 and the reels 4 which are free to rotate in their seats.
All the elementary yarns 5, namely both the core yarns 5a and the strands 5b, meet at the assembly point P to form the packing 14.
The winding step occurs at a winding diameter D as a result of the location of the assembly point P on the surface 15' of the rotary roll 15.
As a result of this rotation, those core yarns 5a and strands 5b which, at the assembly point, are further from the surface 15' of the roll 15, or on the extrados surface of the packing 14, are drawn at a higher velocity than the core yarns 5a and strands 5b which are close to the surface 15', or on the intrados surface of the packing 14, since they follow the same curved path but with a larger radius of curvature in a given unit of time.
The result is that, in its rest condition, the packing 14 produced by the method described above, has a square cross-section and is curved (FIG. 6) with a radius of curvature C which substantially corresponds to the predetermined winding diameter D.
FIG. 7 shows a stuffing box 19 of a pump, not all of which is shown, and which has a drive shaft 20 of radius C'. Packing 14 produced by the method described above is wound around the drive shaft 20 within a chamber 21 defined by a bush 22 and compressed by a gland 23.
The radius of curvature C of the packing 14 must approximate the radius C' of the shaft 20. There is a direct correlation between this latter magnitude and the thickness S of the packing 14 such that, in accordance with normal practice, it is possible, for a particular thickness S of packing, to determine the correct value of the diameter D of the cylinder 15 on which the assembly point P should be located in the machine 1.
What has been stated above is also true for a stuffing box for a valve rod.
In addition to the aforesaid advantage, the method for the production of the packing for stuffing boxes is quick and economic to carry out by conventional equipment.
Moreover, it lends itself to the production of packing of different dimensions, the winding diameter simply being changed by means of the replacement of the roll, while the cross-section need not necessarily be right-angled but may also be circular.
Furthermore, the packing produced by the said method has greater resistance to wear and can rapidly be put into use.
In the case of a pump stuffing box, the quantity of liquid which acts as a lubricant and coolant which passes between the intrados surface of the packing and the surface of the pump shaft is reduced, this quantity however being essential to avoid burning of the packing due to friction and hastened wear.
An expert in the art may make numerous variations in the method for the production of packing for stuffing boxes described above, to the machine for carrying out the method and to the packing thus formed to satisfy various specific requirements, all of which however fall within the scope of protection of the invention as defined by the following claims.
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A method for producing packing for the stuffing of boxes, among other purposes. In one embodiment, the packing enables compressive forces to be transmitted uniformly from a gland along an entire winding of the packing so as to eliminate stresses within the packing itself. The method includes a step in which elementary yarns converge to form the packing at an assembly point and a step in which the packing is wound into a coil starting at the assembly point.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a cab locking apparatus for locking a cab, which is pivotally supported on a chassis frame and movable between a standing position and a forwardly inclined position, in the standing position by engagement with a striker, which is secured to the chassis frame downwardly of a rear end of the cab, so as to prevent the cab from moving toward the forwardly inclined position.
2. Description of the Related Art
A typical conventional cab locking apparatus of the described type is exemplified by Japanese Patent Publication No. 4708/1986. In the known cab locking apparatus, a latch member and a locking plate are pivotally mounted on a base plate. The latch member is pivotally movable between a locking position in which the latch member engages a striker and a unlocking position in which the latch member is removed from the striker. The locking plate is pivotally movable between a restriction position in which the locking plate prevents the latch member from being removed from the locking position and a releasing position in which the locking plate releases the latch member. A lock lever and an input lever are also pivotally mounted on the base plate. The lock lever is engageable with a lower end of the locking plate to hold the locking plate in the releasing. When the latch member is pivotally moved to the locking position, the input lever pushes the lock lever away from the locking plate against the biasing force so that the locking plate is pivotally moved from the releasing position to the restricting position.
It is desirable to minimize the size of a cab lock apparatus in order to increase the interior space and bed space of a cab to a maximum. Particularly the cab locking apparatus to be located under the cab should desirably have a reduced height.
However, with this prior cab locking apparatus, since the apparatus further includes a locking lever disposed downwardly of the locking plate, the apparatus has an increased height, which not only restricts the bed space to impair the inhabitability but also requires the lock lever and a spring to urge the lock lever, thus increasing the number of parts and hence the cost of production.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a cab locking apparatus which improves the inhabitability of a cab, increases the bed space and reduces the cost of production.
According to the invention, there is provided a cab locking apparatus for locking a cab, which is pivotally supported on a chassis frame and movable between a standing position and a forwardly inclined position, in the standing position by engagement with a striker, which is secured to the chassis frame downwardly of a rear end of the cab, so as to prevent the cab from moving toward the forwardly inclined position, the apparatus comprising: a base plate adapted to be supported on the chassis downwardly of the rear end of the cab; a latch member pivotally connected to the base plate and pivotally movable between a locking position in which the latch member is engaged with the striker and an unlocking position in which the latch member is removed from the striker, the latch member being normally urged from the locking position toward the unlocking position; a locking plate pivotally connected to the base plate and pivotally movable between a restricting position in which the locking plate prevents the latch member from being moved from the locking member, and a releasing position in which the locking plate releases the latch member, the locking plate being normally urged from the releasing position toward the restricting position; an input lever disposed between the latch member and the locking plate, which are vertically spaced apart, the input lever being movable between a locking operative position and a releasing operative position for pivotally moving the locking plate between the restricting position and the releasing position; and the base plate having a groove engageable with the input lever to hold the locking plate in the releasing position, when the input lever is moved from the locking operative position to the releasing operative position, so as to prevent the input lever from returning to the locking operative position, the groove being disengageable from the input lever to allow the locking plate to move from the releasing position to the restricting position under the biasing force when the latch member is pivotally moved from the unlocking position to the locking position.
In operation, as the cab is locked, the input lever is in the locking operative position, and the locking plate is held in the restricting position. The latch member is thereby held in the locking position to engage the striker.
Then when the input lever is moved from the locking operative position to the releasing operative position, the locking plate is pivotally moved from the restricting position to the releasing position. At that time, the input lever engages in the groove to hold the locking plate in the releasing position.
When the locking plate is pivotally moved from the restricting position to the releasing position, the latch member is brought from the locking position to the unlocking position under the biasing force, removing from the striker.
When the latch engages the striker, the input lever is then disengaged from the groove so that the locking plate is pivotally moved from the releasing position to the restricting position under the biasing force. As a result, the locking plate holds the latch in the locking position.
The above and other advantages, features and additional objects of this invention will be manifest to those versed in the art upon making reference to the following detailed description and the accompanying drawings in which a preferred structural embodiment incorporating the principles of this invention is shown by way of illustrative example.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front elevational view of a motive lock mechanism of a cab locking apparatus embodying this invention;
FIG. 2 is a perspective view, with parts omitted, of a truck, showing the manner in which the cab locking apparatus is attached to the truck; and
FIGS. 3 through 5 are fragmentary front elevational views of FIG. 1, showing the operation of the motive lock mechanism.
DETAILED DESCRIPTION
The principles of this invention are particularly useful when embodied in a cab locking apparatus such as shown in FIGS. 1 and 2.
As shown in FIGS. 1 and 2, a cab 20 is pivotally mounted on a front end of a truck chassis 10 by a hinge 11 and is pivotally movable between a normal standing position and a forwardly inclined position.
A main frame 12 is mounted on the chassis 10 along a lower rear end portion 21 of the cab 20, and on the main frame 12, an auxiliary frame 15 is supported via a pair of springs 13, 13 and a pair of suspensions 14, 14. To the auxiliary frame 15 a pair of strikers 16, 16 are fixedly connected. Forwardly of the main frame 12, a hydraulic cylinder 17 is disposed for pushing the lower rear end portion 21 upwardly of the cab 20 to pivotally move from the normal standing position to the forwardly inclined position.
For engagement with the respective strikers 16, 16, a motive lock mechanism 40 and a following lock mechanism 50 are located at the lower rear end portion of the cab 20. The motive and following lock mechanisms 40, 50 are substantially alike in construction; therefore, the detailed description of the following lock mechanism 50 is omitted here for clarity.
The motive lock mechanism 40 includes a base plate 41 fixedly mounted on the lower rear end portion 21 of the cab 20. A latch member 42 is pivotally supported on the base plate 41 by a pivot 41a for pivotal movement between a locking position in which the latch member 42 is engaged with the striker 16 and an unlocking position in which the latch member 42 is removed from the striker 16. The latch member 42 is normally urged from the locking position toward the unlocking position by a spring 43 wound around the pivot 41a.
Further, a motive locking plate 44 is pivotally supported on the base plate 41 by a pivot 41b for pivotal movement between a restricting position in which a lock portion of the motive locking plate 44 engages a free end 42a of the latch member 42 to prevent the latch member 42 from being pivotally moved from the locking position, and a releasing position in which the lock portion 44a is removed from the free end 42a of the latch member 42 to release the latch member 42. The motive locking plate 44 is normally urged from the releasing position toward the restricting position by a spring 45 wound around the pivot 41b.
An input lever 46 is pivotally movably connected at its base portion 46a to the free end 44b of the motive locking plate 44. The input lever 46 has in its distal end portion a through opening 46b, through which a connecting pivot portion 61 formed by bending a distal end portion of an operating lever 60 is pivotally movably inserted.
On a base portion of the operating lever 60, a handle portion 62 is formed, and a lock member 63 is pivotally mounted near the handle portion 62. The handle portion 62 is hooked by the lock member 63 and is thereby prevented from being drawn from the locking operative position (inner side) toward the releasing operative position (outer side). The lock member 63 is normally urged by a spring 64 in such a direction as to hook the handle portion 62.
The base plate 41 has a substantially horizontally extending groove 48, in which the connecting pivot 61 is inserted. When the input lever 46 is reciprocatingly moved by operating the operating lever 60, the connecting pivot 61 is moved in and along the groove 48 in response to the reciprocating movement of the input lever 46.
The groove 48 has a restricting/releasing holding groove portion 49. When the operating lever 60 is moved from the locking operative position to the releasing operative position by the biasing force of the spring 45 via the motive locking plate 44 and the input lever 46 in order to hold the motive locking plate 44 in the releasing position via the input lever 46, the connecting pivot 61 is retained in the groove portion 49. And when the latch member 42 is pivotally moved from the unlocking position to the locking position in order that the motive locking plate 44 is pivotally moved from the releasing position to the restricting position under the biasing force of the spring 45, the connecting pivot 61 is hit by the free end 42a of the latch member 42 and is thereby removed from the groove portion 49.
The motive locking plate 44 has at the free end 44b thereof a locking flange 44c which is engageable with a cutout 41c of the base plate 41 when the motive locking plate 44 is pivotally moved from the releasing position to the restricting position.
The motive locking plate 44 also has at the free end 44b thereof a connecting hole 44d in which a base portion 71 of a connecting rod 70 is pivotally movably inserted. A distal end portion of the connecting rod 70 extends to the following lock mechanism 50.
As shown in FIGS. 2 and 3, the following lock mechanism 50, like the motive lock mechanism 40, includes a non-illustrated latch member and a nonillustrated following locking plate. To the free end of the following locking plate, the distal end 72 of the connecting rod 70 is connected.
In operation, in FIG. 3, the latch member 42 is in the locking position where the latch member 42 is engaged with the striker 16 and is prevented, by the motive locking plate 44 whose lock portion 44a is in contact with the free end 42a of the latch member 42, from being pivotally moved from the locking position. Likewise, the latch member of the following lock mechanism 50 is prevented by the following locking plate from being pivotally moved from the locking position.
Thus both the motive lock mechanism 40 and the following lock mechanism 50 assume a locking posture. At that time, the lock member 63 is in its hooking position and hooks the handle portion 62 of the operating lever 60, preventing the handle portion 62 from being drawn from the hooking position.
Now when the lock member 63 is pivotally moved from the hooking position to the unhooking position against the biasing force of the spring 64 to draw the handle portion 62 of the operating lever 60 outwardly, the connecting pivot 61 of the operating lever 60 is moved in the long groove 48 from one end to the other end. The motive locking plate 44 is thereby pivotally moved from the restricting position to the releasing position via the input lever 46. And the connecting pivot 61 of the operating lever 60 is retained in the restricting/releasing holding groove portion 49 so as not to return from the other end to one end.
When the motive locking plate 44 is pivotally moved to the releasing position, the following locking plate is pivotally moved from the resting position to the releasing position via the connecting rod 70.
With both the motive locking plate 44 and the following locking plate in the released position, the latch member 42 is allowed to pivotally move to the unlocking position under the biasing force of the spring 43. Likewise, the non-illustrated latch member of the following lock mechanism 50 is allowed to pivotally move to the unlocking position under the biasing force of a non-illustrated spring.
Then when the lower rear end portion 21 of the cab 20 is pushed upwardly by the hydraulic cylinder 17, the latch member 42 of the motive lock mechanism 40 and the non-illustrated latch member of the following lock mechanism 50 are removed from the respective strikers 16, 16 and are thereby allowed to be forwardly inclined.
With the operating lever 60 in the releasing operative position, when both the motive locking plate 44 and the following locking plate are in the releasing position, the connecting pivot 61 of the operating lever 60 is retained in the restricting/releasing holding groove portion 49 so that the motive locking plate 44 is prevented from returning to the restricting position under the biasing force of the spring 45.
Subsequently, when the operating lever 60 is pushed inwardly to the locking operative position, the connecting pivot 61 of the operating lever 60 is disengaged from the restricting/releasing holding groove portion 49 and is thereby allowed to move to the locking operative position.
FIG. 5 shows the cab 20 in the forwardly inclined position, in which the latches 42, 52 are removed from the respective strikers 16, 16. In FIG. 5, when the operating lever 60 is pushed inwardly to the locking operative position, the motive locking plate 44 is intended to pivotally move from the releasing position to the restricting position via the input lever 46. If the motive locking plate 44 is intended to pivotally move to the restricting position, the free end 42a of the latch member 42 is brought in contact with the lock portion 44a of the motive locking plate 44 to thereby prevent the motive locking plate 44 from being pivotally moved to the restricting position. And the operating lever 60 also is prevented from being pushed toward the locking operative position. Of course, the non-illustrated following locking plate is also prevented from being pivotally moved to the restricting position.
With the cab 20 in the forwardly inclined position, the locking plate does not return to the locking position even by the foregoing operation so that the lock mechanism 40, for example, is prevented from being damaged even when the cab 20 is inadvertently moved from the forwardly inclined position to the normal standing position.
When the cab 20 is moved from the forwardly inclined position to the normal standing position, the latch member 42 is pushed by the striker 16 to pivotally move to engage the striker 16, thus assuming the locking position.
Then when the latch member 42 is pivotally moved from the locking position, the free end 42a of the latch member 42 hits the connecting pivot 61 of the operating lever 60 from the lower side thereof to remove the connecting pivot 61 from the restricting/releasing holding groove portion 49. With the connecting pivot 61 removed from the groove portion 49, the motive locking plate 44 is returned to the restricting position, and the operating lever 60 is returned to the locking operative position.
When the motive locking plate 44 is pivotally moved from the releasing position to the restricting position, the following locking plate is pivotally moved via the connecting rod 70 to assume the restricting position.
As a result, the lock portion 44a of the motive locking plate 44 comes into contact with the free end 42a of the latch member, and the latch member 42 is restricted in the locking position where the latch member 42 engages the striker 16. Meanwhile, the lock portion of the non-illustrated following locking plate comes into contact the free end of the non-illustrated latch member, and the latch member is restricted in the locking position where the same latch member engages the striker 16. Therefore, it is possible to retain the cab 20 on the chassis 10 reliably.
With the cab locking apparatus of the illustrated embodiment, since the motive locking plate 44 is prevented from being pivotally moved to the restricting position even when the connecting pivot 61 of the operating lever 60 is removed from the restricting/releasing holding groove portion 49 of the long groove 48 for some cause, an improved degree of safety can be guaranteed.
According to this invention, partly since the latch member will be removed from the striker when the input lever is moved to the releasing operative position, and partly since the latch member will be held in the locking position when the latch member is engaged with the striker, the height of the entire apparatus can be reduced to increase the interior space of the cab, thus improving the inhabitability. Also the bed space of the cab can be increased. Therefore the apparatus has a simple construction and hence can be produced at a reduced cost.
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A cab locking apparatus engages a striker on a chassis of a truck and holds a cab in a normal standing position, without allowing the cab to be forwardly inclined. To minimize the entire size of the apparatus and the total number of component elements, an input lever is located between a latch member, for engaging and disengaging the striker, and a locking plate, for retaining the latch member in a locking position. When the input lever is moved to a releasing operative position, the input lever is retained in a restricting/releasing holding groove in a base plate so that the latch member can be removed from the striker. When the latch member is engaged with the striker, the input lever is removed from the restricting/releasing holding groove so that the latch member is restricted in the locking position.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional application No. 60/207,053 filed May 25, 2000.
TECHNICAL FIELD
[0002] The invention relates generally to the field of fluid absorbing devices, and more particularly to a device for attaching to an oil pan or transmission pan to absorb oil or transmission fluid that leaks from the gasket seals of these component parts.
BACKGROUND OF THE INVENTION
[0003] Virtually all fossil-fuel-powered land vehicles, such as automobiles, trucks, buses, trains, tractors, and motorcycles, have engines that are internally lubricated with oil. Typically, an oil pan is mounted to the bottom of the engine, and an oil pump is disposed within or near the oil pan. While the engine is not running, the pan acts as a reservoir for the oil. While the engine is running, the oil pump circulates the oil from the pan up into the cylinders and other internal regions of the engine in need of lubrication, and then the oil flows back into the pan and is again circulated by the pump.
[0004] Unfortunately, the oil often leaks from various regions of the engine and drips onto the ground. For example, common regions from which oil may leak are the gasket seal between the rocker-arm covers and the engine, the main-bearing seals, and the gasket seal between the oil pan and the engine. Although these gaskets and seals are intended to provide a leak-proof seal, they often break down over time and allow oil to leak. Typically, this leaking oil flows down the sides of the engine, onto and down the sides of the oil pan, and then drips from the oil pan onto the ground. While the vehicle is moving, the air flow beneath the vehicle may blow the dripping oil onto other portions of the vehicle, such as a rear wheel differential. The blown oil may then drip to the ground from that portion of the vehicle.
[0005] One problem with the dripping engine oil is that it often creates a dirty, greasy, or slick area on the surface over which the car is parked. For example, such areas are clearly visible in most public parking spaces and private garages.
[0006] Another problem is that the dripping oil, whether it drips onto a parking surface or a roadway, often pollutes the environment as rain washes it into the soil or water ways. In fact, many consider dripping engine oil a serious environmental hazard.
[0007] In addition, types of oil other than engine oil may drip from a vehicle and cause problems similar to those discussed above. For example, transmission oil may leak from regions of the transmission including the gasket seal between the transmission oil pan and the transmission housing. The leaking transmission oil flows onto the transmission oil pan, and then drips or is blown from the transmission oil pan onto the ground. Likewise, differential oil may leak from regions of the rear-wheel differential including the gasket seal between the front and rear portions of the differential housing. The leaking differential oil drips or is blown from the differential housing onto the ground.
SUMMARY OF THE INVENTION
[0008] In one aspect of the invention, an oil-drip catcher includes an oil-absorbent material that is removably attachable to a region near an oil-pan or other type of machined assembly having a fluid retaining joint, such as a seal or gasket. The material absorbs the oil that leaks from the joint gasket or from other places above the gasket before the leaking oil can drip to the ground. One can replace the material when it becomes saturated with oil.
[0009] One advantage of such an oil-drip catcher is that because it can be positioned near and beneath an oil-pan gasket, the catcher can absorb leaking oil before it can drip or be blown onto the ground. Furthermore, such an oil-drip catcher is relatively inexpensive, easy to install, easy to replace, and can remain on the vehicle while the vehicle is being driven.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIGS. 1 - 4 are views of an oil-drip catcher attached to an engine oil pan according to an embodiment of the invention.
[0011] [0011]FIG. 5 is a cross-sectional view of the oil-drip catcher of FIGS. 1 - 4 according to an embodiment of the invention.
[0012] [0012]FIGS. 6 and 7 are views of an oil-drip catcher attached to a transmission oil pan according to an embodiment of the invention.
[0013] [0013]FIG. 8 is a side view of an oil-drip catcher that can be used for the oil-drip catcher of FIGS. 1 - 7 according to an embodiment of the invention.
[0014] [0014]FIG. 9 is a cross-sectional end view of the oil-drip catcher of FIG. 8.
[0015] [0015]FIG. 10 is a side view of an oil-drip catcher that can be used for the oil-drip catcher of FIGS. 1 - 7 according to another embodiment of the invention.
[0016] [0016]FIG. 11 is a cross-sectional end view of the oil-drip catcher of FIG. 10.
DETAILED DESCRIPTION OF THE INVENTION
[0017] Referring to FIGS. 1 - 4 , FIG. 1 is a side view, FIG. 2 is an end view, FIG. 3 is a cross-sectional view, and FIG. 4 is a bottom plan view of an oil-drip catcher 10 attached to an engine oil pan 12 according to an embodiment of the invention. The catcher 10 is mounted beneath a flange 14 of the pan 12 , and typically is wrapped all the way around the pan 12 . The flange 14 is typically where the pan 12 is mounted to the bottom of an engine (not shown) with bolts (not shown). An oil-pan gasket (not shown) forms a seal between the flange 14 and the engine. Unfortunately, as discussed above, sometimes the gasket wears out and allows oil to leak from the inside of the engine onto the pan 12 . In addition, oil may leak from other regions of the engine and drip down the sides of the engine toward the oil pan. But because the pan 12 is typically the lowest point of the engine, leaking oil drips down the sides of and onto the pan 12 before it drips to the ground. Therefore, by mounting the catcher 10 beneath and around the flange 14 , the catcher 10 absorbs the leaking oil before it can drip down the sides of the pan 12 and onto the ground. Furthermore, by mounting the catcher 10 close to the flange 14 , the catcher 10 absorbs the leaking oil before it can be blow from the sides of the pan 12 onto the ground.
[0018] Still referring to FIGS. 1 - 4 , the oil-drip catcher 10 may be attached to the oil pan 12 in a number of ways. For example, referring to FIG. 3, a first mounting strip 18 having interlocking fabric hooks and loops (i.e., Velcro®) is attached to the catcher 10 and a second mounting strip 16 also having interlocking fabric hook and loops is attached to the oil pan. Therefore, one attaches the strip 18 to the strip 16 to secure the catcher 10 to the oil pan 12 . In a preferred embodiment, the interlocking fabric hooks and loops include Velcro® H88 products in ½ inch, ⅝ inch or ¾ inch widths, available as product numbers 0174 (hook) and 0199 (loops). In a preferred practice, the hook product is attached to the machined assembly and the loop product is attached to the absorbent material, however, the reverse is also suitable. Alternatively, one may use other techniques for attaching the catcher 10 to the pan 12 . For example, the second mounting strip 16 may be attached securely to the pan using the screws or bolts used to attach the pan 12 to the engine. Alternatively, the second mounting strip 16 may be attached to the pan 12 using a magnetic material or strong adhesive. The first mounting strip 18 can likewise be removably attached to the second mounting strip 16 using a variety of techniques. For example, using a detachable adhesive or a magnetic material attracted to the second mounting strip 16 . In general, the first mounting strip 18 has a first surface removably attachable to a second surface located on the second mounting strip 16 . The second mounting strip 16 in turn has a third surface that is attached to the oil pan 12 . The catcher 10 may be attached to the oil-pan gasket (not shown) such that after the gasket is installed, the catcher 10 is positioned around the pan 12 beneath the flange 14 , or, the catcher 10 may be cemented or otherwise attached to the pan 12 .
[0019] Although discussed as being attached to the oil pan 12 beneath the flange 14 , the oil-drip catcher 10 may be attached to the engine above the flange 14 . In this position, the catcher 10 can absorb the oil leaking from the engine, but may not be able to absorb oil leaking from the oil-pan gasket (not shown).
[0020] [0020]FIG. 5 is a cross-sectional view of the oil-drip catcher 10 and the oil pan 12 of FIGS. 1 - 4 in a region where the pan 12 is near an engine-exhaust pipe 20 according to an embodiment of the invention. While the engine (not shown) is running, the pipe 20 can get quite hot. Therefore, a flame-resistant spacer 22 is placed between the catcher 10 and the pipe 20 to prevent the heat from the pipe 20 from burning or otherwise damaging the catcher 10 . The spacer 22 may be attached to the catcher 10 , to the pipe 20 , or to both the catcher 10 and pipe 20 . Alternatively, the spacer 22 may be wedged between the catcher 10 and the pipe 20 but attached to neither. The catcher may also have an inner 17 and outer 19 surface, with the inner surface being contoured to accommodate the shape of the pan in the region where the catcher 10 is mounted.
[0021] Still referring to FIG. 5, one can omit the spacer 22 in other embodiments. For example, the oil-drip catcher 10 may be formed from a flame-retardant material that can be near or actually touch the exhaust pipe 20 without burning. Alternatively, in a region where the pipe 20 is close enough to the oil pan 12 such that it is difficult or impossible to fit the catcher 10 between the pipe 20 and the pan 12 without the catcher 10 burning, one may omit a corresponding portion of the catcher 10 . That is, one may dimension the absorbent material on the catcher with a recess, such as, for example, a notch in the region where the pipe 20 is close to the pan 12 . In most such cases, because the pipe 20 is so close to the pan 12 , the heat from the pipe 20 burns away most of the oil that leaks into or from this region before the oil can flow onto the sides of the pan 12 and drip onto the ground. Therefore, such notching often causes little or no reduction in the effectiveness of the catcher 10 .
[0022] Although discussed with respect to the exhaust pipe 20 , the spacer 22 or notching technique may be used to accommodate another item that may interfere with the placement or installation of the catcher 10 . More generally, the catcher may be dimensional with a recess that forms a space so that the catcher can be fit on the oil pan without contacting an actual part of the vehicle.
[0023] Referring to FIGS. 6 - 7 , FIG. 6 is a side view and FIG. 7 is a bottom plan view of an oil-drip catcher 10 attached to a transmission oil pan 24 according to an embodiment of the invention. In one embodiment, the catcher 10 is similar to the catcher 10 of FIGS. 1 - 5 . Like the engine oil pan 12 of FIGS. 1 - 5 , the pan 24 has a flange 26 having holes that bolts (not shown) extend through to mount the pan 24 to the transmission housing (not shown). A transmission-oil-pan gasket (not shown) is disposed between the flange 26 and the transmission housing to form a leak proof seal there between. Unfortunately, as discussed above, sometimes the gasket wears out and allows oil to leak from the inside of the transmission onto the pan 24 . In addition, oil may leak from other regions of the transmission, or engine oil may leak from the engine, and drip down the sides of the transmission toward the pan 24 . But because the pan 24 is typically the lowest point of the transmission, leaking oil drips down the sides of and onto the pan 24 before it drips to the ground. Therefore, by mounting the catcher 10 beneath and around the flange 26 , the catcher 10 absorbs the leaking oil before it can drip down the sides of the pan 24 and onto the ground, Furthermore, by mounting the catcher 10 close to the flange 26 , the catcher 10 absorbs the leaking oil before it can be blown from the sides of the pan 24 onto the ground.
[0024] Referring to FIGS. 5 and 6, modifications similar to those discussed with respect to the oil-drip catcher 10 of FIG. 5 can be made to the catcher 10 of FIG. 6 to accommodate an exhaust pipe 20 or another item that may interfere with the placement or installation of the catcher 10 .
[0025] Referring to FIGS. 8 and 9, FIG. 8 is a side view and FIG. 9 is a cross-sectional end view of the oil-drip catcher 10 of FIGS. 1 - 7 according to an embodiment of the invention. The catcher 10 includes at least one strip of oil-absorbent material 28 and the Velcro® strip 18 . In one embodiment, the material 28 is Petroleum Sorbent folded (P-F1 550DD) material manufactured and sold by 3M Corporation. The strip 18 is attached to the material 28 using any compatible technique such as by adhesive or stitching.
[0026] Referring to FIG. 9, in one embodiment the oil-absorbent material 28 is rolled or folded and the ends are stitched together and to the strip 1 . 8 . In other embodiments, however, a single unfolded sheet of the material 28 may be used or multiple folds or rolls of the material 28 may be used. In one embodiment, the oil-drip catcher 10 is formed from sections of 5-inch-by-50-foot rolls of the P-F1 550DD material. Furthermore, any compatible material may be disposed within the interior 30 formed by rolling or folding the material 28 .
[0027] Still referring to FIGS. 8 and 9, although the oil-drip catcher 10 can have many dimensions, in one embodiment it has a width W of approximately three inches and a thickness T of approximately two inches. The catcher 10 also has a length L, which can be selected to accommodate the dimensions of a wide variety of selected vehicles. Alternatively, the length L may be long enough so the catcher can be cut to custom-size the catcher to fit any selected vehicle. Preferably, the catcher is part of a kit that includes instructions on how to mount the catcher or to customize it to fit a variety of vehicles.
[0028] Referring to FIGS. 10 and 11, FIG. 10 is a side view and FIG. 11 is a cross-sectional end view of the oil-drip catcher 10 of FIGS. 1 - 7 according to another embodiment of the invention. The catcher 10 of FIGS. 10 and 11 is similar to the catcher 10 of FIGS. 8 and 9 except that the second mounting strip 18 of FIGS. 8 and 9 is replaced by a mounting strip 32 , which has openings 34 for receiving the pan mounting bolts (not shown) that mount the oil pan 12 of FIGS. 1 - 5 to the engine (not shown). In one embodiment, the strip 32 is positioned such that it lies either beneath or on top of the oil-pan gasket (not shown). Next, the gasket and attached catcher 10 are installed such that the bolts that mount the pan to the engine extend through the flange 14 , through the openings 34 , and into the engine. When the bolts are tightened, the flange 14 compresses the gasket and the strip 32 against the engine housing to form an oil proof seal. This secures the catcher 10 around the pan 12 and beneath the flange 14 . In these embodiments, only a single mounting strip need be used to removably attach the absorbent material to the oil pan. In addition, referring to FIG. 11, in the illustrated embodiment, the region 30 is filled with a material 36 . Any suitable material may be used for the material 36 , such as more of the material 28 or another material.
[0029] Although described as being used with the engine oil pan 12 , the oil-drip catcher 10 of FIGS. 10 and 11 may be modified for use with the transmission oil pan 24 (FIGS. 6 and 7), with a differential housing (not shown), or with other types of oil pans or oil seals, including, but not limited to, valve gasket covers, rocker-arm covers, a differential housing, an oil filter, and a bearing seal. Moreover, the invention is generally applicable to any machined assembly having component parts for storing or permitting a flow or fluid within the machined assembly. For example, the invention is readily adaptable to the cooling system of an engine such as a radiator or water pump where the catcher absorbs a coolant that leaks from these components. Again, the catcher would be attached to the lower portion of the radiator or the engine to capture the fluid leaked therefrom.
[0030] From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention.
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An inexpensive and replaceable fluid absorbing device for capturing fluid leaked from a machined assembly such as an oil pan or transmission is described. The device includes an absorbent material that absorbs the leaked fluid, which is attached to the first mounting strip and the first mounting strip is attached to a second mounting strip. The second mounting strip is attached to an exterior portion of the machined assembly. When the first mounting strip is attached to the second mounting strip, the absorbent material is positioned at a location where fluid leaked from the machined assembly is absorbed by the absorbent material. Once saturated with fluid, the device can be removed by simply detaching the first mounting strip from the second mounting strip and a new device can be attached.
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This is a divisional of application Ser. No. 460,658, filed on Jan. 3, 1990, of Rudolf FUCHS et al., for PROCESS FOR THE PRODUCTION OF 1,3-CYCLOPENTANEDIONE.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the production of 1,3-cyclopentanedione.
2. Background of the Art
1,3-Cyclopentanedione or its derivatives are interesting intermediate products for numerous active ingredient syntheses, e.g., according to Chemical Abstracts, 107:197620 it is useful as the starting product for the production of a prostaglandin intermediate product or according to Tetrahedron Letters, Vol. 22, No. 44, (1981), p. 4385ff, as base substances for the antibiotic Kjellmanianone. Other uses are listed in Aldrichimica Acta, Vol. 10, No. 1, (1977), p. 19.
The known processes for the production of 1,3-cyclopentanedione are just as numerous.
According to widespread synthesis methods, 1,3-cyclopentanedione is used as the starting product, which is converted into 1,3-cyclopentenediol, by oxidation into 1,3-cyclopentanedione and, after final hydrogenation, into 1,3-cyclopentanedione. As described by Lick et al. in Chem. Ber., 111, (1978), p. 2466, these methods are connected with numerous difficulties and are not very successful in the production of considerable amounts of product. The same authors have developed a process of their own in which 2-norbornene is converted into 1,3-cyclopentanedione in a three-step synthesis with a 70 percent yield [Chem. Ber., 111, (1978), p. 2461f].
By the necessary ozonolysis at -60° to -70° C., required twice in the process, the process because of the energy expenditure (cooling, ozone production) is not very profitable for conversion into an industrial process.
BROAD DESCRIPTION OF THE INVENTION
The object of the invention is to provide a process for the production of 1,3-cyclopentanedione that does not exhibit the above-mentioned drawbacks.
It has been found that the object of the invention can be attained in a surprisingly good way by means of the invention process. The invention involves a process for the production of 1,3-cyclopentanedione. In a first step (a) of the invention process, a malonic acid ester in the presence of a base is reacted with a 4-halo-3-alkoxy-2E-butenoic acid ester to a 5,5-bis-(alkoxycarbonyl)-3-alkoxy-2E-pentenoic acid ester of the formula: ##STR1## wherein the radicals R are each the same or different and are an alkyl having 1 to 4 C atoms. In the second step (b), the pentenoic acid ester is cyclized in the presence of a base to the corresponding salt of 5-alkoxycarbonyl-3-alkoxy-2-cyclopentene-1-one of the formula: ##STR2## wherein M is sodium or potassium and R has the above-named meaning. In step (c), the ester function is saponified in the presence of a base. Finally, in step (d), the cyclic compound is decarboxylated in the presence of a mineral acid to the end product.
Decisive for the economy of the invention process is the fact that one can start from commercially-available malonic acid esters and 4-halo-3-alkoxy-2E-butenoic acid esters which are easily available from diketene or 4-haloacetic acid esters.
The invention also includes the 5,5-bis-(alkoxycarbonyl)-3-alkoxy-2E-pentenoic acid esters of the formula: ##STR3## wherein the Rs are the same or different and are alkyl having 1 to 4 C atoms. Preferably the pentenoic acid is 5,5-bis-(ethoxycarbonyl)-3-methoxy-2E-pentenoic acid methyl ester, or 5,5-bis-(methoxycarbonyl)-3-methoxy-2E-pentenoic acid methyl ester, or 5,5-bis-(ethoxycarbonyl)-3-ethoxy-2E-pentenoic acid ethyl ester.
DETAILED DESCRIPTION OF THE INVENTION
Step (a)
According to the invention process, in a first step, a malonic acid ester in the presence of a base is reacted with a 4-halo-3-alkoxy-2E-butenoic acid ester to the corresponding 5,5-bis-(alkoxycarbonyl)-3-alkoxy-2E-pentenoic acid ester. Suitably the malonic acid di-(C 1 -C 4 )-alkyl ester, preferably the malonic acid di-(C 1 -C 2 )-alkyl ester, is used. The 4-halo-3-alkoxy-2E-butenoic acid-(C 1 -C 4 )-alkyl esters are to be considered as suitable derivatives of the 4-halo-3-alkoxy-2E-butenoic acid esters; the 4-chloro-3-(C 1 -C 2 )-alkoxy-2E-butenoic acid-(C 1 -C 2 )-alkyl esters are especially suitable.
Alkali alcoholates, alkali hydroxides or strong organic bases, preferably alkali alcoholates, are used as the base. The term alkali alcoholate is understood to mean sodium or potassium alcoholates of lower aliphatic, optionally-branched, alcohols, such as, methanol, ethanol, propanol or butanol. Suitable representatives of the alkali hydroxides are potassium hydroxide or sodium hydroxide; and DBU [1,8-diazabicyclo(5,4,0)-undec-7-ene] can be used as the strong organic base. Suitably the reaction takes place in the presence of a polar solvent from the series acetonitrile, benzonitrile, lower aliphatic alcohols, such as, methanol or ethanol, 1,2-dimethoxyethane, N,N'-dimethylformamide or N,N'-dimethylacetamide. N,N'-dimethylformamide is the preferred solvent. The reaction temperature is advantageously selected between 0° and 180° C. and is especially preferred between 20° and 60° C.
The previously unknown 5,5-bis-(alkoxycarbonyl)-3-alkoxy-2E-pentenoic acid esters of the formula: ##STR4## are obtained as the reaction product. The radicals R, which correspond to the ester groups or alkoxy groups of the malonic acid esters or 4-halo-3-alkoxy-2E-butenoic acid esters which are used, are the same or different and are alkyl having 1 to 4 C atoms. The 5,5-bis-[(C 1 -C 2 )-alkoxycarbonyl]-3(C 1 -C 2 )-alkoxy-2E-pentenoic acid-(C 1 -C 2 )-alkyl esters are especially advantageous for the synthesis of 1,3-cyclopentanedione. Such compounds can be isolated in the usual way but as a rule are used directly in the following step (b) without special preparation.
Step (b)
Step (b) comprises the ring closure of the 5,5-bis-(alkoxycarbonyl)-3-alkoxy-2E-pentenoic acid esters in the presence of a base. The sodium or potassium alcoholates of the lower aliphatic alcohols methanol, ethanol, propanol or butanol or the alkali hydroxides potassium hydroxide or sodium hydroxide corresponding to step (a) are used as the base. As a rule the alcohol corresponding to the alcoholate is the solvent for the ring closure. But other polar solvents, such as, acetonitrile or benzonitrile, can be used. The ring closure suitably takes place at temperatures between 0° and 180° C., preferably between 20° and 60° C.
The corresponding salt of 5-alkoxycarbonyl-3-alkoxy-2-cyclopenten-1-one of the formula: ##STR5## wherein M is sodium or potassium and R has the above-mentioned meaning, is obtained as the reaction product.
Steps (c) and (d)
To obtain 1,3-cyclopentanedione, the ester group of the salt of step (b) is saponified (step c) and the carboxyl group is finally decarboxylated.
Suitable bases for the saponification are aqueous solutions of sodium hydroxide or potassium hydroxide. The saponification temperature is advantageously between 0° and 100°, preferably room temperature.
The resultant carboxylic acid salt as a rule is not isolated but is further treated in situ with another acid. Suitable acids are the inorganic mineral acids, such as, hydrochloric acid or sulfuric acid.
The decarboxylation and, therefore, the conversion into 1,3-cyclopentanedione goes along with the acid treatment, which suitably takes place at temperatures between 20° and 100° C.
After the usual working up, the desired product can be obtained in good quality and good yields.
The following examples disclose the process according to the invention in more detail.
EXAMPLE 1
(a) Production of 5,5-bis-(ethoxycarbonyl)-3-methoxy-2E-pentenoic acid methyl ester
83.9 g (0.5 mol) of malonic acid diethyl ester was placed in 250 ml of N,N'-dimethylformamide. 27.8 g (0.5 mol) of sodium methylate was added at 20° C.; 10 minutes later 41.6 g (0.25 mol) of 4-chloro-3-methoxy-2E-butenoic acid methyl ester was added within 5 minutes. It was stirred for 2 hours at 20° C. Then 10.8 g (0.2 mol) of sodium methylate was added once more. After stirring for 15 hours at 20° C., N,N'-dimethylformamide was distilled off at 40° to 50° C./20 mbars. 120 ml of water and 100 ml of methylene chloride were added to the residue. After neutralization of the phases, the organic phase was separated and evaporated to dryness. The residue was distilled in a vacuum at 176° to 180° C./20 mbars. 58.8 g (80 percent) of the compound, with a purity of 98 percent (GC), was obtained. Data for the title compound was:
1 H-NMR: (CDC1 3 , 300 MHz) δ:
1.25, t J=6 Hz, 6,
3.4, d J=8 Hz, 2H,
3.6, s, 3H,
3.68, s, 3H,
3.71, t J=8 Hz, 1H,
4.16, q J=6 Hz, 4H,
5.06, s, 1H,
(a1) Production of 5,5-bis(methoxycarbonyl)-3-methoxy-2E-pentenoic acid methyl ester
66 g (0.5 mol) of malonic acid dimethyl ester was placed in 250 ml of N,N'-dimethylformamide. 27.8 g (0.5 mol) of sodium methylate was added at 20° C.; 10 minutes later 41.6 g (0.25 mol) of 4-chloro-3-methoxy-2E-butenoic acid methyl ester was added within 5 minutes. It was stirred for 2 hours at 20° C. Then 10.8 g (0.2 mol) of sodium methylate was added once more. After stirring for 15 hours at 20° C. it was distilled off. After working up according to Example (a) 53.8 g (81 percent) of the title compound, with a purity of 98 percent (GC), was obtained. Data for the title compound was:
1 H-NMR: (CDC1 3 , 300 MHz) δ:
3.4, d, J=8 Hz, 2H,
3.60, s, 3H,
3.66, s, 3H,
3.71, s, 6H,
3.7, t, J=8 Hz, 1H,
5.1, s, 1H,
(a2) Production of 5,5-bis-(ethoxycarbonyl)-3-methoxy-2E-pentenoic acid methyl ester
83.9 g (0.5 mol) of malonic acid diethyl ester was placed in 250 ml of N,N'-dimethylformamide. 27.8 g (0.5 mol) of sodium methylate was added at 20° C., 10 minutes later 48 g (0.25 mol) of 4-chloro-3-ethoxy-2E-butenoic acid methyl ester was added within 5 minutes. It was stirred for 2 hours at 20° C. Then 10.8 g (0.2 mol) of sodium methylate was added once more. After stirring for 15 hours at 20° C., the solvent was distilled off. After working up according to Example (a), 63.75 g (79 percent) of the title compound, with a purity of 98 percent (GC), was obtained. Data for the compound was:
1 H-NMR: (CDC1 3 , 300 MHz) δ:
1.2-1.35, m, 12H,
3.41, d, J=8 Hz, 2H,
3.71, t, J=8Hz, 1H,
3.80, q, J=8Hz, 2H,
4.1-4.18, m, 6H,
5.02, s, 1H.
(b) Production of 5-ethoxycarbonyl-3-methoxy-2-cyclooenten-1-one
9 g (56 mmol) of malonic acid diethyl ester was placed in 50 ml of N,N'-dimethylformamide. 3 g (56 mmol) of sodium methylate was added at 20° C.; 10 minutes later 8.25 g (50 mmol) of 4-chloro-3-methoxy-2E-butenoic acid methyl ester was added within 5 minutes. It was stirred for 1.5 hours at 20° C., after further addition of 0.9 g (17 mmol) of sodium methylate, it was stirred for 1.5 hours more. Then the N,N'-dimethylformamide was distilled off at 40° to 50° C./20 mbars. 100 ml of water and 100 ml of methylene chloride were added to the residue. The organic phase was separated and the aqueous phase was extracted with 80 ml of methylene chloride. The combined organic phases were concentrated by evaporation and the residue was dissolved in 100 ml of ethanol. 3.5 g (51 mmol) of sodium methylate, dissolved in 100 ml of ethanol, was added to this solution during 15 minutes at 20° C. The title compound precipitated out after 2 hours with stirring at 60° C. Then 100 ml of toluene was instilled at 60° C. and cooled to 0° C. 5.43 g (52.5 percent) of the title compound was obtained after filtering and drying. Data for the title compound was:
1 H-NMR: (CDC1 3 , 300 MHz) δ:
1.30, t, J=7.5 Hz, 3H,
2.79, dd, J1=18 Hz, J2 =7.5 Hz, 1H,
3.06, dd, J1 =18 Hz, J3 =3 Hz, 1H,
3.52, dd, J2 =7.5 Hz, J3 =3 Hz, 1H,
3.89, s, 3H,
4,24, q, J =7.5 Hz, 2H,
5.30, s, 1H.
(c) Production of 1,3-cyclopentanedione
2.1 g (10 mmol) of 5-ethoxycarbonyl-3-methoxy-2-cyclopenten-1-one Na salt was placed in 20 ml of water and 5 ml of sodium hydroxide solution (4 N). It was stirred for 2.5 hours at 20° C. Then 2.6 g of hydrochloric acid (32 percent in H 2 O) was added (pH 3). The solution was stirred for 2 hours at 90° C. and then concentrated by evaporation in a vacuum. The residue was suspended in 10 ml of ethanol and filtered. The ethanol phase was concentrated by evaporation. 0.85 g (80 percent) of 1,3-cyclopentanedione was obtained. Melting point of the product was 145° to 147° C. Data for the compound was:
1 H-NMR: (DMSO, 300 MHz) δ:
2.38, s, 4H,
5.10, s, 1H,
11.5-12.5, br. s, 1H.
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A process for the production of 1,3-cyclopentanedione, which is a versatile intermediate product for numerous active ingredient syntheses. For this purpose, a malonic acid ester is reacted with a haloalkoxybutenoic acid ester, the resultant bis-(alkoxycarbonyl)alkoxypentenoic acid ester is cyclized to alkoxycarbonyl alkoxycyclopentenone, the ester function is saponified, and finally the intermediate is decarboxylated to the end product.
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BACKGROUND OF THE INVENTION
This invention relates to an apparatus for repairing the lining of a furnace used in a steel making plant, and more particularly to a spray pipe of non-circular hollow cross-section and the mechanisms to operate the above spray pipe.
A conventional spray pipe has a cross section defined by a complete circle and is generally manipulated such that the pipe is tilted in an upward or downward direction as well as to the right or left and is slidable in an axial direction and is further rotated on the axis of the spray pipe.
Although the above described conventional spray pipe has been sufficient and effective when manually operated, such shooting pipe of circular above cross section is not proper when the revolving or sliding operations of the spray pipe must be mechanically or automatically conducted in order to meet the requirement of improved mobility or operability of the gunning device in currently sophisticated steel making plants.
Therefore the spray pipe must be provided with a guiding mechanism which works with rotating and slide mechanisms.
However, since the conventional pipe is made of a comparatively thin circular tube such as a gas pipe, a guiding mechanism cannot be formed thereon, and even if a guide could be provided by making a keyway along the pipe, the pipe would decrease drastically in rigidity or strength. On the other hand in order to maintain the rigidity or strength, the entire weight of the pipe would be increased and the cost of producing such a pipe is considerably very high.
Accordingly, it is an object of the present invention to provide a shooting pipe with a non-circular cross section which would resolve the aforementioned problems.
Moreover the conventional method for repairing the furnace lining requires at least some number of operators who are under high radiation heat conditions and since the pipe is manually operated, the operators are subject to heavy labor.
Therefore it is another object of the present invention to provide a gunning apparatus which is provided with a above spray pipe and desired mechanism which can manipulate the spray pipe automatically.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view with a part in cross section of the gunning apparatus of the first embodiment of this invention.
FIG. 2 is an enlarged cross sectional view of the above apparatus taken on line I--I of FIG. 1.
FIG. 3 is an enlarged cross sectional view of the above apparatus taken on line II--II of FIG. 1.
FIG. 4 is a side view with a part in cross section of the gunning apparatus of the second embodiment of this invention.
FIG. 5 is an enlarged cross sectional view of the above apparatus taken along the line III--III of FIG. 4.
FIG. 6A through FIG. 6I are cross sectional views of the non-circular shooting pipes applicable to the apparatus of this invention.
FIG. 7 is a side view with a part in cross section of the modification of the apparatus of either first or second embodiment which is provided with a non-circular shooting pipe of a duplicate-pipe construction.
FIG. 8 is an enlarged cross-sectional view of the above apparatus taken along the line IV--IV of FIG. 7.
FIG. 9 is an enlarged cross-sectional view of the above apparatus taken along the line V--V of FIG. 7.
FIG. 10 is an enlarged cross-sectional view of the above apparatus taken along the line VI--VI of FIG. 7.
FIG. 11 is a partial side view with a portion in cross section of the apparatus of the third embodiment of this invention.
FIG. 12 is an enlarged rear end view of the above apparatus taken along the line VII--VII of FIG. 11.
FIG. 13 is another enlarged rear end view of the above apparatus taken along the line VIII--VIII of FIG. 11.
FIG. 14 is a front view with a part broken away of the apparatus of the fourth embodiment of this invention.
FIG. 15 is a front view of the above apparatus repairing a DH furnace.
FIG. 16 is a front view of the above apparatus repairing a RH furnace.
FIG. 17 is a perspective view of the above apparatus in operation.
DETAILED DESCRIPTION OF THE INVENTION
The apparatus for repairing the furnace lining of this invention which is provided with the improved type of spray pipe is hereinafter disclosed in the following embodiments in conjunction with the attached drawings.
First Embodiment
The gunning device of the first embodiment is shown in FIG. 1 through FIG. 3 and is generally used for the repairing of the lining of a converter furnace or an open-hearth furance.
In the drawings, a support column 2 is rotatably mounted on a transport car 1 which in turn is provided with four wheels 3 for facilitating the mobility of the transport car 1.
A rocking sleeve 4 is tiltably mounted on the top of the support column 2 and a long rigid spray pipe 5 having a non-circular hollow cross section thereof is slidably disposed in the rocking sleeve 4.
A spray nozzle 6 is fixed to the front end of the spray pipe 5 while a hose 7 is rotatably connected with the pipe 5 by means of a swivel joint 8.
The hose 7 is connected to a suitable mixer (not shown in the drawing) arranged to supply refractory material in proper form for spraying.
In this invention, the rotating means for rotating the support column 2 on the vertical axis thereof comprises a worm wheel 9 fixedly secured to the base portion of the support column 2, a worm gear 10 which meshes with the worm wheel 9 on the same level, and a drive means such as a power-operated motor for driving the worm wheel 10.
Numeral 12 indicates a tilting means such as a hydraulic cylinder for effecting a rocking movement of the rocking sleeve 4, and this hydraulic cylinder 12 is diagonally disposed on the transport car 1 while numeral 13 indicates a pivot shaft which pivotally connects the rocking sleeve 4 to the support column 2.
The rotating means for rotating the non-circular spray pipe 5 of this embodiment comprises a spur wheel 14 which receives the spray pipe 5 slidably but non-rotatably by way of slide bearing 15, a spur gear 16 which meshes with the spur wheel 14, and a drive means 17 such as a power-operated motor which is mounted on the front end of the rocking sleeve 4 for rotating the spur gear 16.
The means for causing the spray pipe 5 to move longitudinally towards or away from the furnace (not shown in the drawing) or relative to the rocking sleeve 4 is disposed at the rear end of the rocking sleeve 4 and comprises guide rollers 18 which rotate firmly on either side of the non-circular spray pipe 5 so as to move the non-circular shooting pipe 5 back and forth at opposite sides, a drive means 19 such as a power-operated motor for driving guide rollers by way of gear means 20 and a rotating circular plate 21 which is rotatably mounted on the flange portion of the rocking sleeve 4 for integrally rotating the guide rollers 18, drive means 19, and gear means 20 with shooting pipe 5 relative to the rocking sleeve 4 and which are all mounted on the circular plate 21.
At each longitudinal end of the rocking sleeve 4, duplicate bearings 22 are provided wherein the bearings allow the rotation of the non-circular spray pipe 5 relative to the rocking sleeve 4.
Second Embodiment
In FIG. 4 and FIG. 5, which is the second embodiment of the gunning apparatus there is provided with the non-circular spray pipe of this invention wherein the improvement is characterized in that the means for rotating the non-circular rotating pipe 5 relative to the rocking sleeve 4 and a means for the moving the spray pipe 5 back and forth along and within the rocking sleeve 4 are both integrally assembled at the rear end of the rocking sleeve.
The gunning apparatus of this embodiment is further provided with a gear mechanism for permitting the rocking movement of the rocking sleeve instead of the hydraulic cylinder of the first embodiment.
In the assembled construction of the rotating and slide means shown in FIG. 4, a drive means 17' for rotating the shooting pipe 5 is mounted on the rocking sleeve 4 and has a spur gear 16' fixed to the drive shaft thereof. This spur gear 16' meshes with a toothed circular plate 21' which is rotably mounted on the rear flange portion of the rocking sleeve 4. The toothed circular plate 21' is provided with a slide bearing 15' at the center thereof for facilitating the smooth lengthwise movement of the shooting pipe 5. The toothed circulr plate 21' is further provided with means for longitudinally moving the spray pipe 5 back and forth within and along the rocking sleeve 4 and which comprises guide roller means 18' and a drive means 19' for driving the guide roller means 18' by way of gear means 20'.
Referring to the means for permitting the rocking movement of the rocking sleeve 4, numeral 23 indicates a spur gear which is fixedly secured to the drive shaft 24 of a drive means (not shown in the drawing). This spur gear 23 meshes with a semi-circular spur wheel 25 secured to the lower portion of the rocking sleeve 4.
In the above embodiments, the non-circular spray pipe 5 has the cross sections disclosed in FIG. 6. These non-circular or polygonal hollow cross sections have at least one sliding guide surfaces 5a thereof respectively for preventing the rotation thereof on their longitudinal axis. The spray pipe 5 of this invention may be constructed by a plurality of non-circular pipes so that the spray pipe 5 can be extended or retracted in a telescopic manner whereby the lengthwise slide movement of the spray pipe 5 is further improved.
FIG. 9 shows such a construction of the spray pipe which is telescopically extended or retracted in two stages, wherein numeral 5-1 indicates a secondary pipe which slidably but non-rotatably encloses a primary spray pipe 5.
For the above purpose, the primary and secondary pipes 5 and 5-1 have the corresponding hollow square cross sections.
The spray pipe may be further telescopically constructed such that each inner pipe has at least one contacting point on the rotating locus thereof which contacts with the inner surface of the outer pipe so that each contacting point works as a means for preventing the rotation of the inner pipe as well as a means for guiding the reciprocation of the inner pipe.
FIG. 6A through FIG. various show varios cross sections which are suitable as a cross section of the spray pipe of this invention wherein the experiments have proven that the shooting pipes having the cross sections shown in FIG. 6A through FIG. 6D are most suitable and have following advantages;
(i) The refractory material in either wet or dry form can smoothly pass through the pipe.
(ii) The refractory material does not adhere to the inner surface of the pipe.
(iii) The pipe can maintain high rigidity thereof.
To recapitulate the operation of the apparatus of the first and second embodiments, the support column is rotatably mounted on the transport car by means of the drive means and the combination of the worm gear and worm wheel so that the shooting pipe is also rotated on the vertical axis of the support column while the hydraulic cylinder or the gear mechanism which comprises the semi-circular wheel and the drive gear is capable of rocking the rocking sleeve so that the spray nozzle fixed to the extremity of the spray pipe can be displaced vertically within the furnace. The spray pipe is also rotated on its axis within and relative to the rocking sleeve by either a combination of the drive means, gear means and circular rotating plate or a combination of drive means, gear means and circular rotating plate so that the spraying direction of the spray nozzle is displaced at an angle of 360° while the spray pipe is furthermore movable back and forth within and relative to the rocking sleeve so that the spray pipe can be displaced in a lengthwise direction within and relative to the furnace.
Therefore, the spray pipe, or more particularly the spray nozzle fixed to the front end of the spray pipe can be moved vertically and horizontally while the pipe can be also moved back and forth whereby the operation for repairing the furnace lining is conducted mechanically and automatically by a remote control means (not shown in drawings).
Third Embodiment
The third embodiment of the gunning apparatus of this invention is described hereinafter in conjunction with the attached drawings, FIG. 11 through FIG. 13 wherein the improvement is characterized in that the rocking sleeve and the shooting pipe are integrally rotated without rotating the shooting pipe relative to the rocking sleeve as disclosed in the first embodiment.
As shown in FIG. 11, the means for rotating the shooting pipe 5 is constructed such that a slide ring 26 which is pivotally mounted on the top of the support column 2 by a pivot pin rotatably receives the middle portion of the rocking sleeve 4. Adjacent to the slide ring 26, a spur wheel 27 is fixedly secured around the rocking sleeve 4. This spur wheel 27 meshes with a sur gear 28 fixed to the drive shaft of a drive means 29 such as a power-operated motor which is fixedly mounted on the top portion of the slide ring 26.
Another slide ring 30 is rotatably mounted on the rocking sleeve 4 in place and has a lug 31 formed at the lower portion thereof. An actuating rod 32 of a diagonally disposed hydraulic cylinder 33 is pivotally connected by a pin 34 to the above lug 31 while the distal end of the cylinder 33 ia pivotally secured to a lug 35 formed to the side of support column 2.
Referring to the means for moving the spray pipe 5 back and forth relative to the rocking sleeve 4, the construction of the means of the third embodiment corresponds with the construction of previous embodiments with the exception of spring means 36 which biasingly urge the guide rollers 18" so that the rollers 18" can move the spray pipe 5 without causing the slip between surface of rollers 18" and the flat longitudinal surface of the spray pipe 5.
According to the gunning apparatus of this invention, since the spray nozzle of the spray pipe can be easily manipulated vertically and horizontally as well as in a lengthwise direction whereby the operation for repairing the furnace lining is mechanically conducted at the place of operation remote from the vicinity of furnace which is subject to the high-temperature radiation from the furnace.
Fourth Embodiment
The fourth embodiment relates to a gunning apparatus which is characterized in that the gunning apparatus is constructed such that it can repair the lining of a reactor furnace such as a DH furnace (FIG. 15) and a RH furnace (FIG. 16)
A typical structure of the apparatus of this embodiment is described in great detail in conjunction with the attached drawings.
Referring to FIGS. 14 to 17, numeral 41(FIG. 15) indicates a DH furnace, numeral 41a (FIG. 16) indicates an RH furnace, numerals 42 and 42a indicate observation windows through which a viewer can observe the spraying operation within the furnace 41 and 41a and which is disposed on an upper working deck such as the working deck 43 over the furnace 41a. Numerals 44 and 45 in FIG. 16 respectively indicate a suction pipe and a discharge pipe of the furnace 41a. Numeral 44a in FIG. 15 indicates a suction pipe.
With respect to the apparatus which has been devised to enable the optimum degree of repair operations to the furnace, numeral 46 indicates rails laid on a lower working deck 47, numeral 48 indicates a transport car which is movable on the rails 46 and which carries the spraying device thereon, and numeral 49 indicates a hose for supplying refractory material in a wet slurry form through a spray pipe 50 of non-circular cross section to a spary nozzle 51 which is attached to the top of the spray pipe 50. The mechanism for rotating the non-circular spray pipe 50 comprises an inner hollow cylindrical body 52 which permits elevation but which restricts rotation of the spray pipe 50 relative to the cylindrical body 52, a circular bearing means 53 mounted on the transport car 48 and which rotatably supports the inner cylindrical body 52, an outer cylindrical support frame 54 mounted on the car 48 and which also rotatably supports the inner cylindrical body 52, a worm gear 55 fixedly secured to the lower portion of the inner cylindrical body 52, and a worm gear 56 which is rotated by a power-operated motor 57 and which engages and drives the worm gear 55.
The mechanism to elevate the non-circular spray pipe 50 comprises elevating rollers 58 which contact and press against the spray pipe 50 from both sides, a power operated motor 59 mounted on the cylindrical body 52 and which effects rotation of the two rollers 58, and supporting rollers 70 mounted on the cylindrical body 52, which rotatably support spray pipe 50.
Numeral 71 (FIG. 16) indicates a remote control means which is usually manipulated by an operator who stands on the lower working deck, and numeral 72 (FIG. 17) indicates a power operated means to move the transport car 48 along the rails 46.
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A gunning apparatus for repairing a furnace lining is provided with a spray pipe of non-circular hollow cross-section. The spray pipe of non-circular cross section slidably moves back and forth within a rocking sleeve by a slide mechanism while the spray pipe is non-rotatable relative to the slide mechanism and is rotatable only by the rotation of the slide mechanism, whereby the shooting pipe is manipulated without weakening the rigidity or strength thereof which usually occurs on a conventional circular shooting pipe which requires keyways for rotation thereof.
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This invention relates to glass fiber scrap reclamation. In one of its more specific aspects this invention relates to a method of reclaiming scrap glass fibers by introducing the fibers into a glass melting furnace without the removal of binder from the fibers prior to the introduction.
BACKGROUND OF THE INVENTION
In the production of glass fiber products, such as glass fiber insulation and glass strands for reinforcement purposes, some scrap material is produced. This scrap comprises off-specification production, trimmings of insulation batts and the like.
This off-specification material has been disposed of in various ways but methods of reintroducing it into the process to recover the glass have been generally unsatisfactory. One principal difficulty arises due to a chemically-based binder or size which such scrap material has had applied to its surface during processing. When introduced directly into the glass batch, these surface coatings are difficult to burn off and their introduction into the molten glass affects the corrosion rate of the tank in which the molten glass is contained and changes the redox state of the glass. As a result of the latter, the radiant heat transfer characteristics of the furnace are adversely affected.
The method of this invention is directed to allowing the reintroduction of scrap glass into a glass melting furnace while avoiding these difficulties.
STATEMENT OF THE INVENTION
According to this invention there is provided a method for reclaiming chemically coated glass scrap in a glass batch melting furnace which comprises introducing the fibers in discrete form in an oxidizing gaseous stream into the hot oxidizing gases above a glass batch moving over the surface of melted glass within a glass melting furnace. At least a portion of the chemical coating on the surface of the glass scrap is oxidized. Some portion of the glass fibers accumulates on the unmelted glass batch. The unmelted glass batch and the accumulation of glass fibers are moved through the furnace to melt and commingle the glass fibers and the glass batch as molten glass.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view of a typical glass batch melting furnace.
FIG. 2 is a view in elevation of a typical glass batch melting furnace.
DESCRIPTION OF THE INVENTION
The method of this invention is suitable for use in any gas fired furnace. It is particularly suitable for use in furnaces of the type discussed in U.S. Pat. No. 3,885,945 to Rees et al. A furnace of this type is depicted in FIGS. 1 and 2. Referring now to FIGS. 1 and 2, the aforementioned patent discusses a combination hydrocarbon fuel fired, electrode heated furnace 1 into which glass batch is charged through one or more introduction parts 20 in an upstream end wall 2 and molten glass is withdrawn through opening wall 3 in end wall 30. Electrodes 4 are positioned along the length of the furnace in one or more rows spaced from the longitudinal side walls 5 and from each other.
A pulverized glass batch is charged to the furnace in any suitable form and can include cullet. After its introduction, it floats on the molten glass mass 6 as a blanket 7 which is thickest in the region of introduction 8 and which tapers gradually to a leading edge of batch line 9 at its intersection with a molten glass upper surface 10 beyond which the molten glass is withdrawn from the furnace. The batch line is located about two-thirds the length of the furnace downstream from the locus of introduction of the batch.
The furnace will be equipped with hydrocarbon fuel-firing burners 11 along its sides. These burners discharge hot combustion gases above the glass batch and the molten glass in a direction perpendicular to the direction of flow of the glass through the furnace. These burners can be positioned in pairs along the sides with about six burners on each side being located upstream of the batch line and two burners on each side being located downstream of the batch line. In the usual operation of the furnace, only the latter two burners are employed with the remainder of the burners being used for auxiliary purposes. It is the burners downstream of the batch line which are principally employed in the method of this invention and it is principally into the hot combustion gases at and from these burners that the glass and oxidizing gases are projected.
The method of this invention is applicable to all types of glass fiber scrap regardless of the density thereof and the amount of chemical coating thereon. The invention has been employed using both high and low density glass fiber scrap having up to about 15% LOI.
The scrap glass can be introduced into the furnace in any suitable form. Preferably, it will be introduced in particulate form up to about 11/4 inch screen size by means of a blowing wool machine, one or more machines being used depending upon the quantity of scrap glass being introduced.
The scrap glass can be introduced in any suitable gaseous carrier. Preferably, it will be introduced in a gaseous oxidizing stream, such as air, the air being supplied in an amount sufficient to transport the scrap glass into the hot combustion gases above the batch charge and to provide oxygen for the oxidation of the surface coating. Generally, air to scrap glass ratios of preferably about 10 to about 35 cubic feet of air per pound of glass scrap are satisfactory. Sufficient air should be present in the combustion space above the melter surface to enable complete oxidation of the binder contained on the surface of the scrap glass, with some excess air being present. The air-glass mixture is introduced at a velocity of from about 15 to about 25 feet per second or at any velocity, depending upon the locus of introduction, sufficient to carry the air-glass mixture into intimate mixing with the hot combustion gases proximate their locus of production at the burner, that is, at a locus which exposes the glass to oxidation by the combusting gases for a sufficient time to oxidize at least a portion of the chemical coating from the surface of the glass.
The air-glass mixture can be introduced into the furnace at any suitable locus which allows the above described mixing with the combustion gases from the burners. The locus of introduction will determine the quantity of glass which can be successfully introduced.
The air-scrap glass mixture can be introduced through one or more entrance parts positioned in the upstream end wall 2 of the furnace. Preferably, it will be introduced through either ports 21 positioned between the longitudinal sidewalls of the furnace and the batch introduction parts 20, one of which, 20a, can be employed to introduce cullet and two of which, 20b, can be employed to introduce powdered batch. Employing this method of introduction, the amount of scrap glass which can be satisfactorily introduced is up to about 5 weight percent of the total glass pull from the furnace.
The air-scrap glass mixture can be introduced through one or more entrance ports 22 positioned in the longitudinal sidewalls 5 of the furnace. Preferably, it will be introduced through one port opening through each of the sidewalls, the ports being oppositely positioned from about two to about six feet from the upstream end wall. Employing this method of introduction, the amount of scrap glass which can be satisfactorily introduced is between about 2 to 3 weight percent of the total glass pull from the furnace.
The air-scrap glass mixture can be introduced through one or more entrance ports in the downstream end wall of the furnace. Preferably, it will be introduced through one or more peephole ports 23 positioned between the longitudinal side walls of the furnace. Employing this method of introduction, the amount of scrap glass which can be satisfactorily introduced is up to about 15 weight percent of the total glass pull from the furnace.
The air-scrap glass mixture can be introduced into the furnace through any suitable means. Preferably, it will be introduced through an expanding nozzle, for example, a nozzle expanding to about six inches in diameter affixed to a three inch introductory conduit.
As stated above, the glass will preferably be introduced into the hot combustion or oxidation gases from the burner. Some accumulation of the scrap glass on the unmelted batch will occur. This accumulation will, however, be melted to molten glass by the time it reaches the batch line.
The method of this invention is further illustrated by the following example.
A dual heat input furnace, that is, surface gas firing and underglass electric firing, was employed. Coarsely ground 11/4 inch screen, chemically coated scrap having a 15 percent LOI was fed into the furnace. The scrap had been ground in a hammer mill.
Cullet was introduced between the two batch entry points and an air-scrap glass mixture was introduced through a peephole in a downstream portion of the longitudinal side wall. The initial rate of scrap glass introduction was 260 pounds per hour, the rate being increased to 325 pounds of scrap glass per hour without increasing the energy input into the furnace. Air rates under all conditions were within the range of from about 150 to about 175 CFM.
Glass samples were taken during and for three days after the trial. Analysis of these samples showed that the scrap addition had been between 1 and 3 weight percent of the glass pull and that there had been only a slight increase in the ferrous-ferric ratio, which is a measure of the glass redox state. The glass had a 0.4 to 0.5 ratio prior to the scrap glass addition and increased only to 0.5 to 0.6 due to the scrap addition.
The above data demonstrates that the method of this invention provides for the satisfactory reclamation of chemically coated scrap glass fibers without adverse effect upon the glass contents of the furnace into which the scrap is introduced.
It will be evident from the foregoing that various modifications can be made to the method of this invention. Such, however, are considered within the scope of the invention.
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A method of reclaiming chemically coated glass scrap is disclosed. The scrap is introduced into the oxidizing atmosphere of a hydrocarbon-fuel fired glass melting furnace. Some of the glass is melted with the unmelted portion being melted with the glass batch as it moves through the furnace.
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CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims the benefit of U.S. Provisional Application No. 60/874,820 filed Dec. 14, 2006 by Christopher J. Joski.
BACKGROUND
[0002] This invention relates to a tile spacing tool. More specifically, this invention relates to a tool, which is used to easily lay tile and ensures that the joint spacing between the tiles is accurate.
[0003] Laying tile is a tedious and time-consuming task. When laying tile it is extremely important to make certain that the tiles are accurately spaced with respect to one another. If the alignment is even a bit off, the results will look sloppy and unprofessional. In addition, many types of adhesive used to affix tile to a surface set up very quickly. For example, Duraceramic® is a type of flooring product with unique installation procedures that vary from that of ceramic or natural stone. Specifically, the type of adhesive used to install Duraceramic® bonds instantly to a surface. Therefore, it is imperative to properly position Duraceramic® prior to making contact with the laying surface. If a spacing mistake is made once the tile is bonded, it cannot be corrected.
[0004] As a result, efforts have been made to develop tools or devices which assist in accurately positioning tiles, such as tile spacers. Traditional tile spacers are small, cross-shaped plastic pieces, which are placed on the corner of each tile and act as a wedge between adjacent tiles. However, tile spacers have a number of disadvantages. First, it is difficult to accurately position the individual pieces. It is also challenging to ensure that the tile spacers remain in the correct position while laying adjacent tiles in place. Furthermore, when the adhesive is dry, a removal tool is needed to pry the spacers out from between the tiles.
[0005] Thus, there is a need in the art for a tool which allows tile to be laid easily and ensures that the joint spacing between the tiles is accurate.
SUMMARY
[0006] The present invention is a tool used to accurately space tile. The present invention is a tile spacer, which comprises a first spacing rib having a top edge and a bottom edge and comprising a handle and a second spacing rib having a top edge and a bottom edge. The second spacing rib extends longitudinally along a generally perpendicular axis of the first spacing rib to form a generally cross-shaped horizontal spacing surface comprising the bottom edges of each of the first and second spacing ribs.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIGS. 1A-1B are perspective views of an exemplary embodiment of a tile spacing tool.
[0008] FIG. 2A is a perspective view of the tile spacing tool shown spacing two tiles.
[0009] FIG. 2B is a top view of the tile spacing tool shown spacing two tiles.
[0010] FIG. 3 is a top view of the tile spacing tool shown spacing four tiles.
[0011] FIG. 4A is a side view showing possible dimensions of the tile spacing tool.
[0012] FIG. 4B is a top view showing possible dimensions of the tile spacing tool.
[0013] FIG. 4C is a perspective view of the tile spacing tool.
[0014] FIG. 5 is a perspective view of the tile spacing tool as used by an installer to space tile.
DETAILED DESCRIPTION
[0015] FIGS. 1A-1B are perspective views of an exemplary embodiment of tile spacing tool 10 . Shown is tile spacing tool 10 , which comprises first spacing rib 12 A, second spacing rib 12 B, third spacing rib 12 C, first support joint 14 A, second support joint 14 B, third support joint 14 C and handle 16 .
[0016] First support joint 14 A, second support joint 14 B, third support joint 14 C are arranged in a generally cross-shaped orientation. Second spacing rib 14 B extends outward from first spacing rib 12 A in a perpendicular direction to generally form two 90 degree angles with respect first spacing rib 12 A. Third spacing rib 14 C also extends outward from first spacing rib 12 A in an opposite perpendicular direction to generally form two 90 degree angles with respect first spacing rib 12 A. First spacing rib 12 A comprises handle 16 .
[0017] First support joint 14 A and second support joint 14 B are disposed between first and second support ribs 12 A and 12 B. Third support joint 14 C is disposed between second support rib 12 B and third support rib 12 C. First, second, and third support joints 14 A- 14 C ensure that first, second, and third support ribs 12 A- 12 C remain properly positioned with respect to one another and maintain the integrity of the 90 degree angles, which are essential to accurate alignment.
[0018] As shown in FIGS. 1A-1B , tile spacing tool 10 is formed of individual aluminum parts, which are welded together. However, the invention is not so limited and any suitable material may be used. Tile spacing tool 10 may also be formed, for example, of a single unitary piece of molded metal or plastic.
[0019] FIG. 2A is a perspective view and FIG. 2B is a top view of tile spacing tool 10 in use. Shown is tile spacing tool 10 , which comprises first spacing rib 12 A, second spacing rib 12 B, third spacing rib 12 C, first support joint 14 A, second support joint 14 B, third support joint 14 C and handle 16 . Also, shown are tiles 18 A- 18 B and joint 20 A.
[0020] As tile is laid it is extremely important to accurately space tiles with respect to one another. If the alignment or spacing between the tiles is even a little bit off, the end result will look sloppy and unprofessional. Therefore, it is necessary to ensure that the joints between tiles are uniformly spaced throughout the tile laying process.
[0021] In FIGS. 2A-2B , tile spacing tool 10 is shown spacing tiles 18 A- 18 B, which have a square shape. FIGS. 2 and 3A illustrate how tile spacing tool 10 may be used to accurately position and lay tiles 18 A- 18 B. Tiles 18 A- 18 B are spread with a suitable adhesive and placed side by side using tile spacing tool 10 as a guide. First spacing rib 12 A fits snuggly against an edge of each tile 18 A- 18 B. Second spacing rib 12 B extends between tiles 18 A- 18 B, and fits snuggly against an adjacent edge of each tile 18 A- 18 B. Thus, tiles 18 A- 18 B are aligned and second spacing rib 12 B defines a uniform width for joint 20 A, which runs in between tiles 18 A- 18 B.
[0022] FIG. 3 is a top view of tile spacing tool 10 as used to space tiles 18 A- 18 D. Also shown are joints 20 A- 20 C.
[0023] Once tiles 18 A- 18 B are properly positioned and laid, as described with reference to FIGS. 2A-2B , additional tiles may be added using tile spacing tool 10 . As shown in FIG. 3 , third spacing rib 12 C is inserted into joint 20 A, which extends between tiles 18 A- 18 B, until an edge of each of tiles 18 A- 18 B fits snuggly against first spacing rib 12 A.
[0024] Tiles 18 C- 18 D are then spread with adhesive and aligned with tiles 18 A- 18 B using tile spacing tool 10 . Tiles 18 C- 18 D are positioned by placing an edge of each tile 18 C- 18 D against a side of first spacing rib 12 A (opposite the side of first spacing rib 12 A against which an edge of each of tiles 18 A- 18 B is positioned). An adjacent edge of each tile 18 C- 18 D is placed against opposing sides of second spacing rib 12 B. Thus, first spacing rib 12 A defines a uniform width for joint 20 C, which runs in between tiles 18 A- 18 C and tile 18 B- 18 D and second spacing rib 12 B defines a uniform width for joint 20 B, which extends between tiles 18 C- 18 D.
[0025] As a result, tiles 18 A- 18 D are easily and properly aligned and joints 20 A- 20 C are uniformly spaced. Additional tiles may be added using the technique described in FIGS. 2A-2B and FIG. 3 .
[0026] FIG. 4A is a side view and FIG. 4B is a top view showing possible dimensions of an exemplary embodiment of tile spacing tool 10 . As shown in FIG. 4A , tile spacing tool 10 has a height of 4 inches, as indicated by line H and a width of 14.13 inches, as indicated by line W. As shown in FIG. 4B , tile spacing tool 10 may have a length of 9.5 inches, as indicated by line L. However, the invention is not so limited and tile spacing tool 10 may be configured to have any suitable dimensions. In addition, first, second, and third spacing ribs 12 A- 12 C, shown in FIG. 4B , may each have a width of about 0.1 inches to about 1 inch. However, since first, second, and third spacing ribs 12 A- 12 C define joints 20 A- 20 C, as described with reference to FIG. 3 , it is preferred that first, second, and third spacing ribs 12 A- 12 C have identical widths.
[0027] FIG. 4C shows a perpendicular view of tile spacing tool 10 . In the exemplary embodiment shown in FIGS. 4A-4C , support joint 14 A is not used.
[0028] FIG. 5 is a perspective view of tile spacing tool 10 as used by an installer to space tile. As shown, tile spacing tool 10 is grasped by handle 16 and can be easily moved as needed. Tile spacing tool 10 is reusable and may be cleaned and stored for future use.
[0029] Although the present invention has been described with reference to preferred embodiments, workers skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. For example, in some cases the angles between the first and second ribs may not be exactly 90 degrees, but may be in a range of about 80 degrees to 100 degrees.
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A tile spacing tool is used to accurately space tile and comprises a first spacing rib having a top edge and a bottom edge and comprising a handle and a second spacing rib having a top edge and a bottom edge. The second spacing rib extends longitudinally along a perpendicular axis of the first spacing rib to form a generally cross-shaped horizontal spacing surface comprising the bottom edges of each of the first and second spacing ribs.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to improved reaction chambers for use in Chemical Vapor Deposition (CVD) systems, and more particularly to improvements in reaction chambers for use in epitaxial deposition systems for processing wafers on a one-at-a-time basis and for providing a more efficient deposition, a more uniform deposition on the substrate or wafer to be processed, and for reducing or eliminating deposits beneath the susceptor.
2. Description of the Prior Art
Chemical Vapor Deposition (CVD) is the formation of a stable compound on a heated substrate by the thermal reaction or decomposition of certain gaseous compounds. Epitaxial growth is a highly specific type of CVD that requires that the crystal structure of the substrate or wafer be continued through the deposited layer.
Chemical Vapor Deposition systems take many forms but the basic components of any CVD system usually include a reaction chamber which houses the wafer(s) to be processed, a gas control section, a timing and sequence control section, a heat source, and an effluent handling component. A great variety of ways of implementing each of these components leads to a great number of individual reactor configurations in prior art systems.
The purpose of the reaction chamber is to provide a controlled environment for the safe deposition of stable compounds. The chamber boundary may be quartz, stainless steel, aluminum or even a blanket of a non-reacting gas, for example, nitrogen. Commercial epitaxial deposition (epi) reaction chambers are generally classified as being one of the following three general types, depending primarily upon gas flow. Horizontal systems are employed wherein the wafers are placed horizontally on a boat or susceptor and the gas flows horizontally in one end of the reaction chamber, across the wafers, and out the other end. In vertical systems, the wafers are placed horizontally on a susceptor with the gas flow vertically toward the wafers from the top and the susceptor is normally rotated to provide more uniform temperature and gas distributions. In cylindrical or barrel reactor systems, the wafers are placed vertically on the outer surface of a cylinder, and the gases flow vertically into the chamber from the top and pass over the wafers on the susceptor which rotates for uniformity of deposition.
Heating in a cold-wall CVD system is accomplished through the use of radio frequency (RF) energy, or by radiation energy commonly in the ultraviolet (UV), visible, or infrared (IR) bands or by resistance heating. In an RF heated susceptor, the energy in an RF coil is coupled into a silicon carbide coated carbon susceptor. The wafers are heated through their contact with the susceptor. Radiant UV or IR heating is accomplished by the use of high intensity lamps that emit strongly in the ultraviolet, visible, and/or infrared spectrum. The large amounts of energy from these lamps heat the wafers and their holders by radiation. In both types of cold-wall heating, the walls of the chamber are cold, in comparison to the wafers themselves. The chamber walls must be cooled to prevent radiation from the lamps and the susceptor from producing a large temperature rise.
The reaction chamber is used in epitaxial deposition systems to provide the carefully controlled environment needed for the epitaxial deposition to take place is a critical component of the epitaxial reactor. Three basic reactor chamber configurations are used in the semiconductor processing industry including the horizontal reactor, the vertical reactor, and the barrel reactor, all of which were previously described herein.
Prior to reactor heat-up, any residual air that remains in the chamber must be removed or purged. Prior to cool-down, following the deposition cycle, any gases remaining from the growth process are flushed out.
The various gases used in an epitaxial reaction chamber include a non-reactive "purge" gas which is used at the start and end of each deposition if the reaction chamber is opened to the atmosphere after every run as is normally done. The non-reactive purge gas, usually nitrogen, is used to flush unwanted gases from the reaction chamber.
A carrier gas is used before, during, and after the actual growth cycle. The carrier gas is mixed with the gases responsible for etching, growth, or doping the silicon as each is added. Hydrogen, is most often used as a carrier gas, although helium is sometimes employed.
Etching gases may be used prior to the actual epitaxial deposition wherein etching is performed to remove a thin layer of silicon from the surface of the wafer together with any foreign matter or crystal damage that is present on it. The etching prepares atomic sites for nucleating or initiating the epitaxial deposition process.
The carrier gas is normally hydrogen. The source gases for silicon conventionally used for epitaxial depositions include Silane (SiH 4 ); Dichlorosilane (SiH 2 Cl 2 ); Trichlorosilane (SiHCl 3 ); and Silicon tetrachloride (SiCl 4 ). The dopant gases normally used in epitaxial deposition include Arsine (AsH 3 ); Phosphine (PH 3 ); and Diborane (B 2 H 6 ). The etching gas is commonly HCl.
The problems inherent in all prior art systems of Chemical Vapor Deposition, and more particularly in the epitaxial deposition systems, include the non-uniform deposition on the surface of the wafer to be processed; the presence of contaminants in the reaction chamber prior to processing; wall deposits formed on the interior walls of the reactor chamber; deposition of the reactant chemicals on the heated susceptor and its support structure; inefficient gas flow characteristics; slow processing times; and non-uniform depositions due to uncontrolled gas velocity profiles or gas density profiles.
These problems become even more important with the modern trend away from batch processing systems toward single wafer or one-substrate-at-a-time processes. In a single wafer-at-a-time processing system, the same volume of gas normally flowing through a reaction chamber with many wafers to be processed cannot be used since too much reactant gas will be consumed for one wafer. Still further, the cycle times to process a batch of wafers in a conventional batch processing system are far too long for single wafer processing. A single wafer process requires a more rapid deposition rate to minimize the cycle time. Within a single wafer system, the deposits form reaction by-products build-up far more rapidly on a per wafer basis than in batch processing systems. Customers are increasingly demanding reduced particulate contamination. As a result, these deposits must be controlled or minimized in order to reduce the particulate contamination.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide an improved reaction chamber apparatus for use in CVD processing single substrates or wafers on a one-at-a-time basis.
It is another object of the present invention to provide an improved single wafer reaction chamber apparatus for use in epitaxial deposition.
It is yet another object of this invention to provide an improved single wafer reaction chamber apparatus for use in a single wafer CVD system which controls the reactant gas velocity profile to insure uniform depositions.
It is a further object to provide an improved single wafer CVD reaction chamber for producing more uniform deposition than were heretofore possible.
It is still a further object of this invention to provide an improved single wafer CVD reaction chamber with a relatively fast processing time wasting reactant gases.
It is yet a further object to provide an improved single wafer CVD reaction chamber which aids in substantially reduces deposits beneath the susceptor.
It is still another object to provide an improved reaction chamber apparatus for use in a single wafer epitaxial deposition system including a method and apparatus for increasing system efficiency by reducing carrier gas flow consumed on a per wafer basis.
The present invention provides an improved reaction chamber for us in a CVD system, and more particularly, for use in an improved single wafer epitaxial deposition system system for processing a single wafer-at-a-time with greatly improved efficiency. The system of the present invention includes a reaction chamber having a top plate, a bottom plate parallel to the top plate, sides joining the top and bottom plate, a hollow interior with a generally rectangular cross-section, a reactant gas inlet at one end of the hollow interior of the reaction chamber and a gas outlet at the opposite end of the hollow interior of the reaction chamber for exhausting the at least partially spent gases therefrom.
In one embodiment of the improved epitaxial deposition reactor chamber of the present invention, an aperture is provided or formed in an intermediate portion of the bottom panel of the reaction chamber, and a well having a hollow interior cavity is connected with its open end coterminous with the aperture and the remaining portion of the well distending vertically downwardly therefrom. A susceptor support means is housed at least partially within the well for positioning a susceptor for demountably carrying or positioning a semiconductor wafer or substrate to be processed within the circular aperture in the bottom panel of the reaction chamber and either slightly above or slightly below the plane of the bottom panel, as desired. In this embodiment, the use of the well for positioning the susceptor enables the height which is measured as the vertical distance between the top panel and the bottom panel to be substantially reduced to approximately one half of its normal height for providing a reduced cross-sectional area. The reduced cross-sectional area of the hollow interior of the reaction chamber enables the velocity of the reactant gases, which are supplied at a uniform flow rate, to be greatly increased and in fact doubled, so as to greatly reduce the processing time required for an epitaxial deposition operation. Conversely, for a given flow rate, the reduced area results in reduced total gas flow per unit time or per wafer processed.
Normally, reducing the distance between the top and bottom panels is known in the prior art to increase the undesirable wall deposits thereon. However, the present invention reduces the height while simultaneously reducing wall deposits downstream of the susceptor between the susceptor and the gas outlet end of the reaction chamber, as hereinafter described.
In an alternate embodiment of the epitaxial deposition reaction chamber of the present invention, a chamber is provided which has a first bottom panel disposed between the reactant gas input end of chamber and an intermediate portion of the hollow interior of the chamber. A second substantially lower bottom panel is disposed between the intermediate portion of the chamber and the exhaust end thereof. An inwardly curved vertical wall is used to interconnect the first bottom panel with the second or lower bottom panel to provide a dual height reaction chamber. The first height is significantly reduced between the top panel and the bottom panel for decreasing the cross-sectional area thereby greatly increasing the gas flow velocity of the reactant gas for reducing the time required for the deposition operation and greatly reducing the amount of used gases. The lower portion of the chamber has a height which is approximately twice the height of the input end of the chamber, so that it is able to house the susceptor and means for supporting the susceptor within the chamber, and so that it provided ready access to the susceptor and its support structure.
Each of the reaction chamber embodiments can include a quartz bib having an inwardly curved end portion extending partially over the central aperture or inwardly curved vertical wall to overhang the lower panel and at least partially encircle a portion of the circumference of the susceptor for providing a narrow gap therebetween. The inwardly curved portion can be shaped or sized to significantly narrow the gap at the center along the longitudinal axis of the reaction chamber to and widen the gap in both directions toward the sides of the chamber for shaping the velocity profile to a predetermined desired profile for optimizing the uniformity of the deposition on the wafer.
Similarly, instead of a quartz plate laying over the input end of the bottom panel, the bottom panel can be extended horizontally rearwardly to provide the identical effect.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a cross-sectional view of the preferred embodiment of the epitaxial deposition reaction chamber of the present invention;
FIG. 2 shows a partial perspective view of the epitaxial deposition reaction chamber of the embodiment of FIG. 3;
FIG. 3 illustrates a sectional side view of an alternate embodiment to the epitaxial deposition reaction chamber of FIG. 3;
FIG. 4 is a partial perspective view of the embodiment of the epitaxial deposition reaction chamber of FIG. 11;
FIG. 5 is a partial sectional side view of the input end of an epitaxial deposition reaction chamber showing a quartz bib disposed on the bottom panel adjacent the outer periphery of the susceptor;
FIG. 6 is a blow-up of the circled portion of FIG. 5 showing the detail in the gap area;
FIG. 7 is a blow-up of the circled portion of FIG. 5 showing an alternate embodiment to the quartz plate thereof;
FIG. 8 shows a top view of the susceptor, wafer, and quartz plate of FIG. 5 illustrating the gap therebetween;
FIG. 9 is a partial sectional side view of the input end of the dual height epitaxial deposition reaction chamber of FIGS. 3 and 4 showing a quartz plate therein;
FIG. 10 is a top view taken along view lines 10--10 of FIG. 5 and showing the relationship of the quartz plate to the susceptor;
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a sectional side view of the preferred embodiment of the epitaxial deposition reaction chamber of the present invention which is referred to herein as the "reduced area"; deep well" reaction chamber 11. The reaction chamber 11 is shown as including a top panel 13 and a bottom panel 15. Each of the panels 13 and 15 is an elongated, generally rectangular, substantially planar quartz panel which is substantially transparent to visible and shorter wavelength radiation in a predetermined frequency range for producing a "cold-wall" reactor while enabling the radiation to penetrate to the hollow interior 17 of the reaction chamber 11. The chamber 11 further includes a front end 19 having a reactant gas input 21 and a rear end 23 having a spent gas output 25. The gas flow at the input end 19 of the reaction chamber 11 is indicated by the gas flow direction arrow 27.
In an intermediate portion 29 of the hollow interior 17 of the reaction chamber 11, a circular aperture 31 is disposed in the lateral center of the bottom panel 15. A cylindrical well 33 operably distends substantially vertically downward from the bottom panel 15 at the outer peripheral edge of the circular aperture 31. The well 33 includes cylindrical walls 35, a circular well bottom, floor or base 37, and a hollow interior or well cavity 36 formed interiorly of the cylindrical walls 35 and the well bottom 37. A circular aperture or base aperture 39 is formed in the center of the bottom 37 of the well 33. Positioned above the center of the base aperture 39 within the top portion of the well cavity 36 and at least partially within the circular base aperture 31, a susceptor assembly 41 is housed. The assembly 41 includes a susceptor 43 having a planar top surface 55 for demountably positioning or carrying one substrate or wafer 45 to be processed. The susceptor 45 may be supported by support apparatus including a pedestal 47, and a shaft 49 distending vertically downwardly from the center bottom portion of the pedestal 47. The shaft 49 passes through the center of the hollow cavity 36 of the well 33 and through the base aperture 39 for connection to drive means positioned therebelow, as hereinafter described. A gasket or seal member may be positioned within the base aperture 39 about the shaft 49 for sealing purposes, and conventional bearings may also be used.
An annular gap 53 is formed within the outer peripheral portion of the circular aperture 31 between the outer peripheral, rim, edge, or circumference 59 of the susceptor 43 and the upper lip 55 of the well 33 where the bottom plate 15 meets the vertically disposed cylindrical well wall 35.
The reactant gases flow through the intermediate portion 29 of the reaction chamber 11 and a major portion of the reactant gas flow passes over the top surface of the wafer 45 to be processed while some portion (not shown) attempts to pass downwardly through the gap 53 and into the hollow interior 36 of the well 33 in the area beneath the susceptor 43. Any reactant gas passing through the annular gap 53 can form undesirable chemical coatings or deposits on the heated undersurface of the susceptor 43 and its support structure 47, 49, the interior 36 of the well 33, and the like, and these deposits may cause contamination problems, loss of time for cleaning, greatly reduced efficiency of the system, etc.
The vertical distance or height "d 1 " measured between the interior surface 63 of the top panel 13 and the interior surface 65 of the bottom panel 15 is approximately one half of the distance previously used in the prior art systems. Reducing the height of at least the input portion of the reaction chamber 19 simultaneously reduces the cross-sectional area of the hollow interior 17 thereof.
The reduction of the height "d" to the distance "d 1 " would normally prevent the reaction chamber 11 from being able to house the susceptor assembly as required therein. Therefore, the provision of the well 33 provides the additional space required for housing the susceptor 43 within the well 33 and at least partially within the circular aperture 31 of the bottom panel 15 for positioning the susceptor 43 and the wafer 45 demountably positioned thereon at least one of coplanar with the plane of the bottom surface 17 or slightly vertically disposed above said plane, in order to obtain an optimal deposition on the wafer 45. The height or depth of the well 33 is given by "d 2 " and this dimension is approximately equal to or slightly greater than the height "d 1 ".
The purpose of the reduced area input portions of the first embodiment of the reaction chamber 11 and the alternate embodiment of the reaction chamber 81 (as hereinafter described) is to reduce the gas flow required for a given deposit. The embodiment of the reaction chamber 11 of FIG. 1 reduces the gas flow required for a given deposition by a factor of approximately one half or more. Assuming the d 2 is slightly greater than d 1 , even greater efficiencies can be realized. In order to control wall deposits in order to reduce the negative impact of the throughput by reducing the volume of the input area of the quartz tubes.
FIG. 2 shows a perspective view of the reaction chamber 11 of the preferred embodiment of the present invention of FIG. 1. The reaction chamber 11 is shown as including a top panel 13 and a bottom panel 15. A pair of sides 71 are shown as interconnecting the edges of the top and bottom panels 13 and 15 to form an elongated, box-like construction having a rectangular cross-section and a generally hollow interior. The front end 19 of the reaction chamber 11 is shown as including a flange portion 77. The flange 77 is positioned adjacent a combination gate and reactant gas injector port 75, as hereinafter described. The opposite or rear end 23 of the reaction chamber 11 is shown as including a flange 73 surrounding a spent gas outlet 22 for exhausting the at least partially spent gases from within the hollow interior of the chamber 17.
The reaction chamber 11 is shown as having a circular aperture 31 disposed within an intermediate portion 29 of the floor 15 of the chamber 11, and a well 33 has its top opening coincident with the aperture 31. The well 33 has a generally cylindrical wall 35 depending substantially vertically therefrom and extending downward to terminate in a circular well floor or base 37. The plane of the base 37 is substantially parallel to the plane of the bottom panel 15, and the height of the well "d 2 " is approximately equal to or slightly greater than the height of the chamber, measured as the perpendicular distance between the planes of the top panel 13 and the bottom panel 15. The base 37 of the well 33 includes a central base aperture 39 which has, distending vertically downwardly therefrom, an elongated hollow tube 79 having cylindrical walls 80, a hollow interior 83, and a purge gas inlet 83.
FIG. 3 illustrates a second embodiment to the epitaxial deposition reaction chamber 11 previously described. In FIG. 3, the reaction chamber 81 is generally referred to as a "dual height" reaction chamber. The chamber 81 has a top panel 83 which is an elongated, generally rectangular, substantially planar, quartz panel which is transparent to higher frequency radiant energy so as to form a cold-wall reactor whose walls are transparent to heat energy in a predetermined frequency range so that the walls remain cool while any absorbing material such as the susceptor and wafer in the hollow interior 87 of the reaction chamber 81 can be heated for facilitating the deposition reaction. The reaction chamber 81 also includes a first or front bottom panel 85 disposed between the front end 19 of the reaction chamber 81 and an intermediate portion 29 thereof. A vertical wall 87 depends substantially vertically downward from the end of the first or front bottom panel 85 and terminates in a second or rear bottom panel 89 which is an elongated, generally rectangular, substantially planar, quartz panel.
A circular aperture 41 is formed in an intermediate portion 29 of the second bottom panel 89. A hollow tubular element 91 depends vertically downward therefrom, and a shaft 49 depends vertically downward through the hollow interior 93 of the tube 91 along the longitudinal axis thereof. Purge gas is supplied to an inlet 95 in the tube 91 and the purge gas is supplied to the hollow interior 93 bounded by tube walls 99 of the tube 91 and then into the lower hollow interior portion 111 of the reactor 81 via the bottom circular aperture 41. The purge gas flow is shown by the purge gas flow direction arrows 97 and, the purge gas works exactly the same as the purge gas usage previously described with reference to the preferred embodiment of the reaction chamber 61 of the present invention. The shaft 49 is shown as supporting the pedestal 47 which in turn supports the susceptor 43 which demountably carries or positions a wafer 45 thereon.
The front end 19 of the reaction chamber 81 of FIG. 3 is shown as including flange members 101 and a reactant gas injector port and gate assembly 103 is mounted in abutting relationship to the flange member 101 for injecting reactant gases into the input 21 of the reaction chamber 81. Similarly, the rear 23 of the reaction chamber 81 includes flanges 105 and a spent gas output port and gate assembly 107 having a spent gas outlet 25. Furthermore, the beginning of the vertical wall 87 at the junction of the first floor or bottom wall 85 is referred to as the lip 109 and the area between the lip 109 and the outer peripheral circumference, rim or edge 59 of the susceptor 45 defines a gap 110 therebetween. The gap 110 connects the hollow interior 87 of the front end 19 of the reaction chamber 81 with the hollow interior 111 beneath the susceptor assembly 43 and the hollow interior 113 of the intermediate portion 29 and rear portion 23 of the reaction chamber 81.
FIG. 4 represents a perspective view of the dual height epitaxial deposition reaction chamber 81 of the alternate embodiment of the present invention. In FIG. 4, the reaction chamber 81 is shown as having a top panel 83, a first or front bottom panel 85 and a second or rear bottom panel 89. The vertical height between the top panel 83 and the rear bottom panel 89 is approximately equal to or slightly greater than twice the height of the input end of the reactor 81 measured as the perpendicular distance between the inside surface 115 of the top panel 83 the inside surface 117 of the front bottom panel 85 of FIG. 3.
The front end 19 of the reaction chamber 87 is shown as terminating in a flange 101 positioned in a cooperating relationship with an input gate and reactant gas injector 103. The rear end 23 of the reaction chamber 81 includes a flange 105 surrounding a gas outlet 25 for exhausting the at least partially expended, reacted, or spent reactant gases from the hollow interior 17 of the reaction chamber 81. The front bottom panel 85 is shown as terminating in a curved vertical wall portion 35 whose bottom portion terminates the front end portion 19 and of the front bottom panel 85. The height of the rear end portion of the reaction chamber 81, as measured between the inside surface 119 of the top panel and the inside surface 120 of its rear bottom panel 89 is equal to or slightly greater than twice the height of the front end portion 19 of the reactor 81 as measured between the inside surfaces 119, 120 of the top 83 and the second lower panel 89.
An intermediate portion 29 of the rear bottom panel 89 includes a circular aperture 41 communicating with the top opening in a hollow cylindrical tube 91 distending vertically downwardly from the bottom surface of the second bottom panel 89 and including a hollow interior 93 surrounded by wall 99 and a purge gas inlet 95 disposed therein for supplying purge gas to the hollow interior of the reaction chamber 81, as previously described.
FIG. 5 illustrates yet another embodiment of the improved epitaxial deposition reaction chamber 11 of the present invention which includes further means for improving the deposition process while eliminating or at least significantly reducing undersirable chemical deposits beneath the susceptor 43 and within the well 33, as previously described. In FIG. 5, the reduced area deep well reaction chamber 11 is shown as previously described in FIG. 1, and like reference numbers designate like components, as known in the art, except that a bib or quartz plate 121 is disposed with its bottom surface 118 on the interior surface 117 of the bottom panel 15 between the front end 19 and the susceptor 43. The plate 121 is shown as including an extension portion 122 which extends past or beyond the lip 61 of the well 33 so that the gap 53 of FIGS. 1 and 2 is substantially reduced to a relatively narrower gap 125 disposed between the rear edge or end portion 124 of the plate 121 and the outer peripheral rim or circumference 59 of the susceptor 43. The reduced area gap 125 further restricts the ability of the reactant gas 27 to pass through the reduced area gap 125 and beneath the susceptor 43 to form undesirable deposits thereon. The plate 121 is a separate piece of quartz material and will be further described hereinafter.
FIG. 6 represents the dotted circle 91 of FIG. 5 and illustrates a portion of the apparatus of the system of FIG. 5 in greater detail. In FIG. 6, the flow arrow 27 illustrates that the reactant gas is passing over the wafer 47 and the bifurcated arrow 28 illustrates that a small portion of the reactant gas is passing through the narrowed gap 125 into the area 36 beneath the susceptor 43 and its support components. This reactant gas 28 causes undesirable deposits beneath the susceptor and on the support components which can result in contamination of the wafer 45. The quartz plate or bib 121 is shown as having its lower surface 118 operatively supported on the upper interior surface 117 of the lower wall 15. The wall 15 terminates in the vertical distending wall 35 of the well 33 and the area of intersection of the upper surface 117 of the lower wall 15 and the interior surface of the well wall 35 is referred to by the reference numeral 61 designating the lip of the well 33. An extension portion or end portion 122 of the quartz plate 121 extends beyond the lip 61 and parallel to the inside surface of the floor 37 of the well 33 as previously described. The lower surface portion 124 of the extension portion 122 extends beyond the lip 61 and over the floor 37 of the well 33 while the outer end portion 127 represents the rear end portion of the plate 121. The outer peripheral circumference or rim 59 of the susceptor 43 is spaced a predetermined distance away from the outer end portion 124 of the plate 121 and a narrowed gap 125 exists therebetween. The gap 125 communicates with the hollow interior 36 within the well 33 as previously described.
An alternate embodiment of the separate bib or quartz plate 81 is shown in FIG. 7. In FIG. 7, the individual plate 81 is replaced with an extension 129 of the bottom panel 15 of the reaction chamber 11. In FIG. 7, the extension 129 is shown as overhanging the lip 61 of the wall 35 of the well 33 since it extends radially inward over the entrance to the well as defined by the circular aperture 31 in the base 15, so that the point where the bottom surface 15 meets the cylindrical wall 35 of the well 33 is defined as the lip 61, and the extension or overhang 129 passes horizontally outwardly thereover and terminates in the rear end portion 131 having the identical structure to the end portion 122 of the plate 81 previously described with reference to FIG. 7. The result achieved by the embodiment of FIG. 7 is substantially identical to that achieved with FIGS. 5 and 6, and the gap 125 is narrowed to the reduced area gap 135 and shaped or dimensioned so as to have the narrowest gap portion 143 at the center and the widest gap portions 147 at the sides for reducing the chance of reactant gas flow into the area beneath the susceptor as shown in FIG. 8. The reduced gap 135 is wider than reduced gap 125 to compensate for increased heating of the plate or bib 121 from the susceptor 45 in the area which is further downstream.
FIG. 8 shows a top view of the susceptor 45, wafer 47, and the bib or quartz plate 121 of FIG. 5. The plate 121 is shown as including a relatively straight front end 141 which is generally perpendicular to the longitudinal axis 151 of the reactor 11, a pair of generally parallel sides 137, 139 which are generally parallel to the longitudinal axis 151 and to the sides of the reactor 11 and perpendicular to the rear end 141, and a top planar surface 120. The sides 137, 139 are spaced a predetermined distance from the sides of the reactor chamber 11 or in an abutting relationship thereto, as desired. The rear end 143 of the plate 121 is inwardly curved at the front end so as to provide a relatively narrow gap 145 between the outer peripheral edge of the inwardly-curved end portion 143 and the outer peripheral rim or circumference 149 of the susceptor 43. The gap 145 between the inwardly curved end portion 143 and the outer peripheral rim or circumference 59 of the susceptor 43. The gap 145 between the inwardly curved rear end portion 143 and the outer peripheral edge 59 of the susceptor 43 which is at least partially encircled thereby is non-linear. The inwardly curved end portion 143 is shaped or designed so as to produce a relatively narrow gap 145 at the center of the plate 121 along the longitudinal axis 151 of the reaction chamber 11, and the gap 145 widens as the inwardly curved surface 143 at the rear end extends laterally outward from the longitudinal axis 151 towards the chamber sides so that the gap continues to widen until it reaches a maximum width 147 between the outer longitudinal end portions of the sides 137, 139 of the plate 121 and the outer peripheral rim 59 of the susceptor 45.
As can be seen in FIG. 8, the rearwardly extending ends of the sides 137, 139 forming the widest gap portions 147 and the wall 143 of the rear end portion 143 at least partially encircle a portion of the outer peripheral circumference 59 of the susceptor 45, and in fact, encircle nearly 180° of the circumference 59. Therefore, the gap 145, 147 extends almost 180° about the outer peripheral rim 149 of the susceptor 45 and continually widens as it goes laterally from the narrowest center gap portion 145 toward the widest side gap portions 147 on opposite sides of the outer peripheral rim 149 of the susceptor 45. The narrowing of the gap 145 along the longitudinal center line or axis 151 of the reactor 45 further reduces the chance of the reactant gas passing therethrough and forming undesirable deposits beneath the susceptor 45. Furthermore, the reduced area gap 145, 147 produces a positive effect on the reactant gas flow thereover. It serves to partially reshape the velocity profile of the gas passing thereover to insure the production of a more uniform deposition on the surface of the wafer 47.
FIG. 9 illustrates a second embodiment to the epitaxial deposition reaction chamber 11 previously described. In FIG. 9, the reaction chamber 81 is generally referred to as a "dual height" reaction chamber. The chamber 81 has a top panel 83 which is an elongated, generally rectangular, substantially planar, quartz panel which is transparent to ultraviolet energy so as to form a cold-wall reactor whose walls are transparent to heat energy in a predetermined frequency range so that the walls remain cool while the interior 87 of the reaction chamber 81 is heated for facilitating the deposition reaction. The reaction chamber 81 also includes a first or front bottom panel 85 disposed between the front end 19 of the reaction chamber 81 and an intermediate portion 29 thereof. A vertical wall 87 depends substantially vertically downward from the end of the first or front bottom panel 85 and terminates in a second or rear bottom panel 89 which is an elongated, generally rectangular, substantially planar, quartz panel.
A circular aperture 41 is formed in an intermediate portion 29 of the second bottom panel 89. A hollow tubular element 91 depends vertically downward therefrom, and a shaft 49 depends vertically downward through the hollow interior 93 of the tube 91 along the longitudinal axis thereof. Purge gas is supplied to an inlet 95 in the tube 91 and the purge gas is supplied to the hollow interior 111 of the lower portion of the reactor 81 via the bottom circular aperture 41. The purge gas flow is shown by the purge gas flow direction arrows 97 and, the purge gas works exactly the same as the purge gas usage previously described with reference to the preferred embodiment of the reaction chamber 11 of the present invention. The shaft 49 is shown as supporting the pedestal 47 which in turn supports the susceptor 43 which demountably carries or positions the wafer 45 thereon. The bib or quartz panel 121 is shown as being disposed with its bottom surface 118 upon the interior top surface 117 of the first bottom panel 85 and located between the front end 19 and the susceptor 43. An extension portion 124 of the quartz plate 121 extends beyond the lip 61 of the junction of the intermediate end of the first lower panel 85 with the top of the vertical wall 88 such that the horizontal extension 124 overhangs the second bottom panel 89 and is substantially parallel thereto. This reduces or narrows the gap 125 between the curved rear end surface 127 of the plate 121 and a portion of the outer peripheral rim or circumference 59 of the susceptor 43, as previously described. It will be seen that the height "d 4 " of the rear end portion 23 of the chamber 81 is substantially equal to twice the vertical height "d 3 " measured between the interior surface 115 of the top panel 83 and the interior surface 117 of the first bottom panel 85 at the front end portion of the reactor 81. In addition to providing the necessary space for mounting the susceptor 43 the wafer 45 pedestal 47 and shaft 49, which could not otherwise be housed within the space between the top panel 83 and the first bottom panel 85, the dual height portion of the reaction chamber 81 at the rear end 23 provides adequate access space for installing the susceptor assembly and the plate 121, as desired.
FIG. 10 shows a sectional top view of a portion of the reaction chamber 81 of FIG. 9 illustrating the gap 125 between the inwardly curved end portion 127 of the plate extension 122 and the outer peripheral rim or circumference 59 of the susceptor 45. The plate 121 is again shown as having a rear end 141 and a pair of parallel sides 137, 139 which are generally perpendicular to the front end 141 and generally adjacent to the sides of the plate 121. The rear end portion 125 has an inwardly curved surface 143 which defines a narrow gap 145 between the inwardly curved surface 143 and the outer peripheral circumference 59 of the susceptor 45. The gap 125 is shown as including a relatively narrow center portion 145 disposed along the longitudinal axis 151, and the gap 145, 147 is shown as ever widening from the narrow central portion 145 to the widest gap portion 147 at the opposite ends of the gap 147. The inwardly curved surface 127 is shaped to provide this non-linear gap. It will be seen that a portion of the outer circumference 59 of the susceptor 43 is encircled within the inwardly curved portion forming the gap 125. Some portion less than 180° of the circumference of the susceptor 43 is so-encircled. The apparatus, instruction, operation and methodology of the dual height epitaxial deposition reaction chamber 81 of FIGS. 9 and 10 are substantially identical to that previously described, and will not be repeated herein. Anything previously described as an improvement on the reaction chamber 11 can be similarly applied to the reaction chamber 81 described herein.
As a parallel to the alternate embodiment of FIG. 10 to FIG. 9 a corresponding alternate embodiment exists to the structure of the dual height reaction chamber 81 of FIGS. 9 and 10 and it is indicated by the dotted horizontal extension 181 of the first bottom wall 85 extending horizontally beyond the lip 61 of the vertical wall 88 into and over the second portion of the reaction chamber 81 and the bottom 89 thereof. The extension 181 serves to replace the quartz plate 121, as previously described, and will not be further described herein.
In the preferred embodiment, the entire reaction chambers 11 and 81 have walls 13, 15 and sides 65 made of quartz or any suitable material which is transparent to the radiation used to heat the hollow interior of the reaction chamber 11, 81. Such chambers 11, 81 are typically referred to as "cold wall reactors". Typically, the material of the pedestal, the distending shaft, the elongated hollow tubular element, and the bib or plate 121 is also fused quartz.
The wafers to be processed are typically silicon semiconductor wafers, since epitaxial deposition is the deposition of a single crystal layer on a substrate (often, but not always, of the same composition as the deposited layer), such that the crystal structure of the layer is an extension of the crystal layer of the substrate. In this case, we can assume that a layer of silicon is being deposited into the surface of the silicon substrate or wafer to be processed.
The susceptor typically includes a graphite (carbon) body having a thin coating of silicon carbide over the outer surface thereof. The graphite is "susceptible" to being heated. The "flush" gas used at the beginning and end of each deposition, is a non-reactive gas, such as hydrogen and sometimes nitrogen, which is used to flush away unwanted gases from the reaction chamber. Prior to the reactor heat up, any residual air that may inadvertently have entered the chamber is removed by the flush process. A carrier gas such as hydrogen is used in the preferred embodiment of the present invention, although helium may also be used. The gases used in almost all epitaxial depositions of silicon are compounds containing one silicon atom and four other atoms that are either chlorine or hydrogen or a combination of the two. The four most commonly used sources of silicon include Silane (SiH 4 ); Dichlorosilane (SiH 2 Cl 2 ); Trichlorosilane (SiHCl 3 ); and Silicon Tetrachloride (SiCl 4 ). Similarly, the gases most commonly used to control the type of conductivity and the resistivity of the epitaxial layer must be compatible with the gases already present in the reaction chamber. These are referred to as dopant gases and the most commonly used include Arsine (AsH 3 ); Phosphine PH 3 ); and Diborane (B 2 H 6 ).
It will be seen that in either the reduced area embodiment of the deposition reaction chamber 11 or in the dual height reaction chamber 81, that either the separate quartz plate or bib can be used or a horizontal extension of the lower wall at the input end of the reaction chamber to narrow the gap between the outer peripheral rim of the susceptor and the inwardly curved end portion thereof.
Likewise, the system of the present invention can be used in any conventional epitaxial deposition operation although it is preferably used with the reaction chamber and susceptor positioning system disclosed and described in assignee's U.S. Pat. No. 4,821,674, which is expressly incorporated by reference herein.
It will be noted that in order to optimize the spacing between the level of the susceptor with respect to the level of the bottom of the reactor, the shaft and pedestal supporting the susceptor can be selectively raised or lowered and finely tuned or adjusted for optimal performance of the system. Furthermore, the shaft can be rotated to rotate the susceptor and the wafer demountably carried thereon in order to average out imperfections in the deposition process and provide a truly uniform deposition on the surface of the wafer. In fact, the importance of shaping the velocity profile of the incoming reactant gases lies in the fact that the velocity profile produced can be shaped to produce either a linear thickness distribution upstream-to-downstream or a truly uniform coating on the surface of the wafer. If the wafer is rotated, the linear deposition will be averaged out and a truly uniform deposition will result. Various features of the quartz plate, the narrowed gap, and the like, further tend to produce or shape the desired velocity profile to optimize the uniformity of the deposition.
The narrowing of the cross-sectional area of the reaction chamber which results, serves to greatly increase the velocity of the gas therethrough, reducing processing time, reducing wasted gas, and reducing the amount of gas required for performing the deposition process so that the process becomes much more efficient, especially for processing a single wafer on a one-at-a-time basis, as contemplated by the system of the present invention.
It will be recognized, by those skilled in the art, that various modifications, variations, alterations, substitutions, and changes can be made in the structure, components, materials, and the like set forth in the preferred embodiments described herein without departing from the spirit and scope of the present invention, which is limited only by the appended claims.
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An improved reaction chamber for use in an epitaxial deposition process for processing a single wafer-at-a-time includes a cold-wall reactor having a substantially rectangular cross-section. The cross-sectional area of the reaction chamber is substantially reduced to increase the efficiency of the system. Apparatus is provided to maintain the wall temperature within a predetermined range for insuring that only readily cleanable deposits are formed. The susceptor assembly is mounted within a wall distending vertically downward from the bottom of the chamber or within a second portion of a duel height chamber having a greater cross-sectional area. A method and apparatus is provided for supplying purge gas to prevent the flow of reactant gas and the undesirable deposits resulting therefrom from forming beneath the susceptor. The flow of reactant gas beneath the susceptor is controlled by a quartz plate for narrowing the gap between the input end of the reactor and the susceptor and for simultaneously shaping the gap to provide a desired velocity profile. Alternatively, a horizontal extension of the floor of the cavity can be provided to perform substantially the identical function. Furthermore, two types of reactant gas injectors can be used for controlling the result in velocity profile of the injected gases.
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DESCRIPTION OF PRIOR ART
Powder metallurgy is a metal-forming technique that allows the economic mass production of relatively complex shaped parts from metal powders. The impact and fatigue strength of such parts are quite low because of the presence of pores throughout the part. The low dynamic properties of these porous substances severely restrict the use of such parts. For example, the impact strength of powder metal ("P/M") parts is important for many applications, e.g., gears wherein a critical region is at the root of the gear teeth with weakness at that point leading to gear failure; and in hammers for use in hammer type mills wherein a critical area is the area between the head and the shank. Imperfection in this area can lead to failure.
While it is well known that increasing the density of a part will, generally, significantly improve its dynamic properties, much higher densities usually are at the expense of higher cost. It is, therefore, an object of the instant invention to improve the dynamic properties of a porous part by means other than by raising its density. A further object of the invention is to significantly improve the dynamic properties of a porous P/M part without raising its density and without a significant increase in cost.
SUMMARY OF THE INVENTION
The present invention significantly improves the impact and fatigue strength of porous P/M parts by using a finer powder, for instance -150 or -170 mesh, in comparison to the widely, if not exclusively, used state of the art -80 or -100 mesh powders. The invention results in significantly (20 to 30%) improved impact and fatigue strength at identical values of sintered density. The improvements are effective over a wide range of densities.
DETAILED DESCRIPTION OF THE INVENTION
The porous P/M parts of this invention having improved impact and fatigue strength are produced from a fine powder mixture having a particle size of for example -150 or -170 mesh. The resulting parts are pressed and sintered using procedures typical of industrial practice and, for instance as described in Metals Handbook, Vol. 7, Powder Metallurgy, Published by American Society of Metals, Metals Park, Ohio, p.322 and 360. Dogbone tensile bars (MPIF standard No. 10) as well as Izod impact bars were made and then tested for density, tensile strength, yield strength, elongation, impact strength and fatigue strength. Such testing indicated that the use of a finer powder mesh significantly improved the impact strength, fatigue strength and elongation at about the same density.
The following specific examples are illustrative of the present invention.
EXAMPLE 1
A very widely used commercial iron powder, designated as A1000 (available from Hoeganaes Corp.), was blended with 0.9% graphite (commercially available and widely used in the industry) and with 0.75% Acrawax C (Chemical Abstracts Reg. No. 110-30-5) using typical pressing and sintering procedures. Dogbone tensile bars (MPIF Standard No. 10) as well as Izod impact bars, were made. The compacting pressure was 30 tsi. The sintering conditions were: 30 minutes at 2050 degrees F. in dissociated ammonia. The sintered bars were then tested for density, ultimate tensile strength, yield strength, elongation, impact (unnotched Charpy) strength, and fatigue strength.
EXAMPLE 2
Materials and procedures were identical to Example 1 except that the +150 mesh fraction of the iron powder was removed by screening prior to its use. A comparison of the properties of this example with those of Example 1 indicated that the removal of the +150 mesh fraction significantly improved impact strength, fatigue strength, and elongation at about the same density.
EXAMPLE 3
An iron powder of the designation A1000PF, (available from Hoeganaes Corp.) was blended with 0.5% graphite (Lonza Electrographite), 0.75% Acrawax C, and 0.05% boron (in the form of an alloy powder). The powder blend was pressed into Izod impact bars having a density of about 7.0 g cm 3 . The bars were sintered in a vacuum furnace at about 2050 degrees F. for about 30 minutes. Thereafter they were copper-infiltrated also in a vacuum furnace at about 2050 degrees F. for about 7 minutes. The bars were then heated to about 1650 degrees F. for about 30 minutes to achieve an austenitic microstructure. After quenching in water, the bars were tempered at about 350 degrees F. for about 60 minutes. Density, impact strength and hardness were then determined using three samples.
______________________________________Density, g/cm.sup.3 7.8Impact Strength, Ft. lbSample 1 69Sample 2 72Sample 3 90______________________________________
EXAMPLE 4
The impact bars of this example were made exactly as in Example 3 with the exception that the coarse +100 and +170 mesh fractions were removed from the iron powder prior to its use. The properties of these bars are shown in the following table:
______________________________________ +100 mesh +170 mesh removed removed______________________________________Density, g/cm.sup.3 7.8 7.8Impact strength, ft. lbSample 1 64 112Sample 2 100 117Sample 3 105 123______________________________________
It is clear from a comparison of Examples 3 and 4 that not only did the impact strength significantly improve (by 52%) by removing the +170 mesh fraction, but also the scatter of the individual data points became much narrower. This feature is very desirable as it allows the design engineer to use this material with superior reliability and at a higher percentage of its average value. Furthermore, these examples also demonstrate that the instant invention can be applied to different P/M compositions as well as to infiltrated materials.
EXAMPLE 5
A recently developed binder-treated powder, consisting of 0.9% graphite, 0.75% Acrawax C, and a balance iron (1000A) designated as "Bondalloy" (available from Hoeganaes Corp.) was processed as the material of Example 1. The properties of the sintered bars were then determined in like manner.
EXAMPLE 6
The sintered bars of this example were made from the same raw materials as in example 5 except that the +170 mesh fraction was removed prior to use. Processing was identical to that in example 5. The same properties were then determined.
A comparison of the results of examples 5 and 6 shows that the instant invention is also effective with this recently developed binder-treated powder.
The present invention is not intended to be limited to the disclosure herein, and changes and modifications may be made by those skilled in the art without departing from the spirit and the scope of the present invention. Such modifications and variations are considered to be within the purview and the scope of the present invention and the appended claims.
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The present invention relates to porous powder metal (P/M) parts having improved dynamic properties such as impact and fatigue strength. These properties are achieved by the use of finer metal powders.
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BACKGROUND OF THE INVENTION
This invention relates to an improved liquid-phase concentrated sulfuric acid process for the indirect hydrolysis of an olefin to produce a lower aliphatic alcohol.
It is known to produce a lower aliphatic alcohol by reacting the corresponding olefin with concentrated sulfuric acid to form an ester reaction product and thereafter hydrolyzing the ester reaction product to form a lower aliphatic alcohol. This process is characterized by producing large quantities of dilute sulfuric acid together with some undesirable by-products. For this process to be feasible, it is essential that the dilute sulfuric acid be purified and concentrated so that it can be recycled to the esterification reaction.
It is also known to concentrate the dilute sulfuric acid effluent from this process by means of a direct heat immersion-burner unit. In addition to concentrating the dilute sulfuric acid, the immersion-burner effects a combustion of the undesirable by-products present in the dilute sulfuric acid effluent and thus purifies the sulfuric acid being concentrated serving to facilitate the recycling of the acid to the process.
A serious draw-back to the direct heat immersion-burner concentration step is that the environment in the evaporator or concentrator is very corrosive. The effective life of the direct heat immersion-burner is unusually short under the extremely corrosive conditions prevailing. Short immersion-burner life or early failure is, therefore, a serious limitation or bottleneck in this process.
An improved process has been developed which substantially reduces the immersion-burner corrosion problem and which is more efficient in the utilization of the heat energy input.
SUMMARY OF THE INVENTION
According to this process, an aliphatic olefin having from 2 to 4 carbon atoms is reacted with concentrated sulfuric acid to form an ester reaction product of said olefin and said sulfuric acid. Water is added to the ester reaction product to promote hydrolysis of the ester reaction product. The aqueous dilute ester reaction product is introduced into a stripping column and contacted with steam to effect stripping of the aliphatic alcohol obtained from the hydrolyzed ester overhead.
Dilute sulfuric acid is withdrawn from the stripping column and introduced into a first stage evaporator employing indirect heat exchange. The steam generated in this evaporator is passed into the stripping column to effect the stripping procedure referred to above. The partially concentrated sulfuric acid is then passed into a second stage direct heat evaporator to further concentrate the sulfuric acid and to oxidize or burn off the impurities in the sulfuric acid. The so concentrated and purified sulfuric acid is recycled to the initial olefin esterification reaction.
DESCRIPTION OF THE DRAWING
Referring to the drawing, FIG. 1 is an illustration of a stripping column and first stage evaporators wherein the principal aspects of the present process are conducted.
Stripping column 1 is connected to feed line 4 through which the dilute ester reaction product is introduced into the top of the stripping column. Line 8 is connected to the bottom of the stripping column and to first stage evaporator 2 and serves to conduct the stripped and diluted sulfuric acid bottoms and by-products into the evaporator. Line 5 is a steam line connecting evaporator 2 to a low point in the stripping column. Steam generated in the evaporator 2 by indirect heat exchange (not illustrated) is passed into the stripping column via line 5 for the purpose of stripping the dilute ester reaction product feed.
Evaporator 3 is a second evaporator in the first stage evaporation step. Line 9 connects evaporator 2 to evaporator 3. Steam generated in evaporator 3 by indirect heat exchange is passed into the stripping column via connecting line 6. The partially concentrated sulfuric acid from the first stage indirect heat evaporation step is removed via line 10 and passed into a second stage direct heat evaporator not illustrated.
DETAILED DESCRIPTION OF THE INVENTION
In accordance with this process an aliphatic olefin and concentrated sulfuric acid are contacted in a suitable reaction vessel to effect a reaction and the formation of an ester of the olefin and sulfuric acid in an ester reaction product. The olefins which can be employed are the lower aliphatic olefins having from 2 to 4 carbon atoms. These will include ethylene, propylene, 1-butene and 2-butene. In general, the olefin feed mixture will contain at least about 65 percent of the desired olefin in admixture with the related saturated aliphatic hydrocarbons. It is preferred to employ an olefin feed mixture containing at least about 70 percent of olefin with the most preferred feed mixture containing greater than 80 up to 100 percent olefin. Commercial olefin feed streams will usually have from 70 to 85 percent of olefin present.
It is essential in this process to employ a concentrated sulfuric acid in the ester reaction. The sulfuric acid must have a concentration greater than 70 percent. The preferred concentration for this process is from about 73 to 80 percent sulfuric acid. The esterification reaction is conducted at a temperature ranging from about 40° to about 60°C under a pressure of from about 16 to 20 atmospheres.
Water is added to the ester reaction product to promote hydrolysis of the ester to the corresponding aliphatic alcohol and regeneration of sulfuric acid. The amount of water employed is not critical but should be a substantial excess over that needed to effect complete esterification of the ester reaction product. This process can be expedited by heating the aqueous dilute ester reaction product. Heating the ester reaction product at a temperature above about room temperature up to about 100°C is increasingly effective for promoting the hydrolysis reaction with temperatures from 50° to 100°C. being preferred.
The substantially hydrolyzed ester reaction product is introduced into the top of a stripping column while steam is introduced near the bottom of the stripping column. The aliphatic alcohol from the hydrolyzed ester is taken off overhead from the stripping column. At the same time, the dilute sulfuric acid from the hydrolysis reaction is removed from the bottom of the stripping column. This sulfuric acid solution will generally have a sulfuric acid concentration of less than about 45 percent and generally from about 35 to 45 percent.
The dilute sulfuric acid solution is conducted into a first stage evaporator employing indirect heat exchange. While any means of indirect heat exchange is effective for the first stage evaporation, steam has been found most convenient. Steam at a temperature from about 120° to 150°C under a pressure from about 2 to 10 atmospheres is highly effective as the indirect heat source in the first stage evaporator. This first stage evaporation by indirect heat exchange can be conducted using two or more evaporators. In a typical example, steam at about 125°-130°C under about 2.5 atmosphere is employed in a first evaporator and steam at 140°-150°C. under about 5 atmospheres is employed in a second evaporator.
In general, the dilute sulfuric acid which leaves the stripper column at a concentration of from 40 to 45 percent is concentrated up to a range from about 55 to 65 percent in the first stage indirect-heat evaporator. It is preferred to conduct this evaporation in one or more steps to effect a concentration in the range from about 60 to 65 percent.
The first stage evaporation is essential to the effectiveness of the present process. In the first place, the steam generated in this evaporation is employed in the stripping column for removing the lower aliphatic alcohol produced overhead. This procedure provides important overall economies in the heat input to this process amounting to about 0.8 to 1 ton of steam per ton of alcohol produced.
More importantly, effecting a major part of the concentration of the sulfuric acid in the steam evaporator employing indirect heat exchange removes a substantial evaporation load from the direct heat immersion-burner unit. This is a critical feature in the present process because of the short life of the immersion-burner in the corrosive environment prevailing. By reducing the evaporation load on the direct heat immersion-burner, the through-put or capacity of this process is increased by a factor of 2 to 2.5 which is a most surprising aspect of this process. A further significant improvement is the reduced amount of exhaust gas emissions due to the reduced use of the direct heat immersion-burner which facilitates the meeting of statutory clear air standards by this process.
The alcohols produced correspond to the olefin in the feed stream. This process is particularly suited to the production of ethyl alcohol, isopropyl alcohol and the butyl alcohols, such as sec. butyl alcohol.
The following examples further illustrate preferred embodiments of this invention.
EXAMPLE 1
PRODUCTION OF ISOPROPYL ALCOHOL (IPA)
In a pressure-proof stirring vessel, 2.1 kg per hour of a 73 percent sulfuric acid are reacted with 0.95 kg of a liquified propene-propane-mixture (ratio 85/15) at a temperature of 60°C, whereby 0.65 kg per hour of propene are absorbed so that 2.75 kg per hour of a reaction mixture of isopropyl alcohol, i-propyl sulfate, sulfuric acid, and water (thick C 3 ester) is yielded. 2.75 kg of the said thick C 3 ester are diluted with 1.1 kg of water at a temperature of 80°C and are prehydrolyzed at this temperature for 0.5 to 1 hour.
1150 grams of the resultant dilute C 3 ester (specific gravity at 20°C: 1.15) are passed per hour at a temperature of 80°C via line 4 to the head of stripping column 1. The 1150 grams of dilute IPA ester contain 5.5 moles of chemically combined propylene i.e., about 86 percent as free alcohol and 14 percent as sulfuric acid ester. Thus, the said dilute ester is composed of 34.5 percent of sulfuric acid, 28.8 percent of crude alcohol (including ether) and of 36.7 percent of water.
The ratio of sulfuric acid to water is 48.5 : 51.5 parts by weight.
The aqueous isopropyl alcohol is now stripped with 283 grams of steam per hour in countercurrent flow via head 7 in stripping column 1 and subsequently is condensed. Simultaneously, the sulfuric acid ester, still present in the dilute ester, is hydrolyzed to sulfuric acid and isopropyl alcohol.
The ratio of sulfuric acid to water of 48.5 : 51.5 present in the said dilute ester, is reduced to a ratio of sulfuric acid to water of 42 : 58 in the stripping column by means of the stripping process.
On account of the isopropyl alcohol being stripped off the described dilute ester, 488 grams per hour of an aqueous crude alcohol with about 67 percent by weight of isopropyl alcohol are yielded.
The 283 grams of the steam per hour required in stripping column 1 are produced in evaporators 2 and 3 by reconcentrating the alcohol-free 42 percent sulfuric acid discharged from the stripping column 1 to 60 percent.
The steam developed is passed to the stripping column via lines 5 and 6.
The reconcentration of the sulfuric acid is conducted by means of indirect addition of energy in Stage 1, 2 with a steam of 2.5 atmospheres at 127°C and in Stage 2, 3 749 grams of a 53 percent sulfuric acid is reconcentrated to 662 grams of a 60 percent sulfuric acid by evaporating 87 grams of water.
The sulfuric acid to be reconcentrated is passed to the evaporators 2 and 3 via lines 8 and 9. 662 grams of a 60 percent sulfuric acid per hour are passed via line 10 for the final reconcentration to 73 percent and for cleaning into said immersion-burner unit.
EXAMPLE 2
PRODUCTION OF SEC.-BUTYL ALCOHOL (SBA)
0.675 kg of butene are absorbed by 1.83 kg of a 75 percent sulfuric acid at 53°C from butene-butane-mixture (ratio 72/28) in a pressure proof extraction column, whereby 2.5 kg of a reaction mixture of sec.-butyl alcohol, butyl sulfate, sulfuric acid, and water (thick C 4 ester) are obtained, said reaction mixture being diluted with 1.5 kg of water at 80°C and prehydrolyzed at this temperature for 0.5 to 1 hour.
1 liter of the resultant dilute C 4 ester (specific gravity at 20°C: 1.320) is supplied per hour to the stripping column via line 4.
1320 grams of dilute SBA ester contain 3.9 mole of combined butene. About 84 percent thereof are present as free sec.-butyl alcohol whereas 16 percent are bound as sulfuric acid ester.
The ratio of sulfuric acid to water is 47.5 : 52.5 parts by weight.
The dilute ester comprises in composition 37.0 percent of sulfuric acid, 21.9 percent of crude alcohol, and 41.1 percent of water.
The aqueous sec.-butyl alcohol is stripped with 349 grams of steam per hour in stripping column 1 via head 7, thereby yielding 507 grams of aqueous crude alcohol with about 57 percent by weight of sec.butyl alcohol.
The sulfuric acid ester is hydrolyzed in the stripping column to sulfuric acid and sec.-butyl alcohol.
The ratio of sulfuric acid to water of 47.5 : 52.5 in the said dilute SBA ester is diluted by means of the stripping process to a ratio of sulfuric acid to water of 42 : 58 parts by weight.
The change in concentration in the stripping column is comparable with the one described in Example 1.
The 349 grams of steam per hour required in the stripping column are produced in the evaporators 2 and 3 by reconcentrating the discharged 42 percent sulfuric acid.
The foregoing examples illustrate the more important advantages of the novel process of the invention. Substantial overall heat energy input is reduced to the extent of 0.8 to 1 ton of steam per ton of alcohol produced by employing the steam from the first stage evaporators in the stripping column. Corrosion losses to the immersion-burner in the second stage direct heat evaporator are very significantly reduced because a major part of the required evaporation is completed in the first stage evaporator.
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Process for the production of an aliphatic alcohol comprising reacting an olefin having from 2 to 4 carbon atoms with sulfuric acid to form an ester reaction product, diluting said product with water and steam stripping to remove a lower aliphatic alcohol overhead leaving a dilute sulfuric acid solution, concentrating said dilute sulfuric acid solution in a first stage indirect evaporator, recycling the steam generated in this first stage evaporator to the steam stripping step, further concentrating the sulfuric acid solution in a second stage direct heat evaporator to form a concentrated sulfuric acid solution and recycling said concentrated sulfuric acid solution for reaction with fresh olefin feed.
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FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO SEQUENCE LISTING, A TABLE, OR A COMPUTER LISTING APPENDIX
Not applicable.
COPYRIGHT NOTICE
A portion of the disclosure of this patent document contains material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or patent disclosure as it appears in the Patent and Trademark Office, patent file or records, but otherwise reserves all copyright rights whatsoever.
FIELD OF THE INVENTION
The present invention relates generally to boating equipment. More particularly, the invention relates to a retractable caution flag that mounts on a boat.
BACKGROUND OF THE INVENTION
The present invention is a caution flag for water sports safety. When a person participating in a water sport such as, but not limited to, water skiing or tubing falls into the water, the boat is required to fly an orange, 12-inch-by-12-inch caution flag to warn other boats in the area of the presence of a person in the water. The only safety flag currently available is a manually operated flag. In typical use of this currently known flag, one person on the boat is assigned the duty of holding the flag until the person skiing or tubing falls into the water when the person holding the flag raises the flag into the air. Or else, someone on the boat must find the flag after the person skiing or tubing has already fallen into the water and then lifts flag into the air. This requirement can sometimes be a nuisance to abide by; however, it is definitely an important requirement for the safety of the skiers and other people participating in water sports.
In view of the foregoing, there is a need for improved techniques for providing an automatic caution flag that can be attached to a boat.
BRIEF DESCRIPTION OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like reference numerals refer to similar elements and in which:
FIGS. 1A and 1B illustrate an exemplary retractable caution flag assembly ready to be mounted onto a boat, in accordance with an embodiment of the present invention. FIG. 1A is a diagrammatic side view and FIG. 1B is a side perspective view;
FIG. 2 is a diagrammatic side view of an exemplary flag for a retractable caution flag assembly, in accordance with an embodiment of the present invention;
FIGS. 3A and 3B illustrate an exemplary lower flagpole guide for a retractable caution flag assembly, in accordance with an embodiment of the present invention. FIG. 3A is a diagrammatic top view, and FIG. 3B is a diagrammatic side view; and
FIG. 4 is a diagrammatic side view of an exemplary caution flag assembly mounted to a boat, in accordance with an embodiment of the present invention.
Unless otherwise indicated illustrations in the figures are not necessarily drawn to scale.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention is best understood by reference to the detailed figures and description set forth herein.
Embodiments of the invention are discussed below with reference to the Figures. However, those skilled in the art will readily appreciate that the detailed description given herein with respect to these figures is for explanatory purposes as the invention extends beyond these limited embodiments. For example, it should be appreciated that those skilled in the art will, in light of the teachings of the present invention, recognize a multiplicity of alternate and suitable approaches, depending upon the needs of the particular application, to implement the functionality of any given detail described herein, beyond the particular implementation choices in the following embodiments described and shown. That is, there are numerous modifications and variations of the invention that are too numerous to be listed but that all fit within the scope of the invention. Also, singular words should be read as plural and vice versa and masculine as feminine and vice versa, where appropriate, and alternative embodiments do not necessarily imply that the two are mutually exclusive.
The present invention will now be described in detail with reference to embodiments thereof as illustrated in the accompanying drawings.
Detailed descriptions of the preferred embodiments 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.
It is to be understood that any exact measurements/dimensions or particular construction materials indicated herein are solely provided as examples of suitable configurations and are not intended to be limiting in any way. Depending on the needs of the particular application, those skilled in the art will readily recognize, in light of the following teachings, a multiplicity of suitable alternative implementation details.
Preferred embodiments of the present invention provide a hands free, retractable flag that easily mounts to a bimini top of a boat. A bimini top is an open-front cover for the cockpit of a boat, usually made of canvas supported by a metal frame. Most biminis can be collapsed when not in use, and raised again if shade or shelter from rain is desired. Preferred embodiments allow the flag to come up to warn other boaters of a person in the water. Preferred embodiments are usually mounted on the right side of the boat where the spotter sits. In the present embodiment when a skier or tuber falls into the water, the spotter releases a trigger and the flag pops out of a tube, and when the skier or tuber is up and skiing or tubing, the spotter retracts a lever and the flag goes back inside the tube.
FIGS. 1A and 1B illustrate an exemplary retractable caution flag assembly 100 ready to be mounted onto a boat, in accordance with an embodiment of the present invention. FIG. 1A is a diagrammatic side view and FIG. 1B is a side perspective view. In the present embodiment, an aluminum housing unit 105 comprises a slot 110 with a range of motion which allows a flag 115 on a flagpole 120 to extend from housing unit 105 . Aluminum housing unit 105 is preferably 36 inches in length by 1 and 1/16 inches in outside diameter and 13/16 of an inch in inside diameter. However, housing units in alternate embodiments may be various different sizes and may be made of various different materials. In the present embodiment, slot 110 , which is cut into the side of housing unit 105 , starts 6 and ⅜ inches from the bottom of housing unit 105 and ends 21 inches from the bottom of housing unit 105 . At the bottom of slot 110 , a short section of slot 110 is situated at a right angle to the rest of slot 110 to create a safety lock. In alternate embodiments the slot may be various different sizes and may be located in different places on the housing unit. In the present embodiment, a trigger lever 125 in slot 110 , which is attached to flagpole 120 , can be pulled down through slot 110 to compresses compression spring 140 in housing unit 105 . At the bottom of slot 110 , trigger lever 125 can be slid into the safety lock to lock flagpole 120 in a retracted position. When trigger lever 125 is released the flag extends into an upright warning position, as shown by way of example in FIGS. 1A and 1B . Trigger lever 125 may be made of various different materials including, but not limited to, aluminum, stainless steel, plastic, etc. Trigger lever 125 is preferably rounded at the end for safety with no sharp edges; however, trigger lever 125 may not be rounded. The other end of trigger lever 125 is threaded to be screwed into a lower guide for flagpole 120 , shown by way of example in FIGS. 3A and 3B . In the present embodiment the top end of housing unit 105 is threaded on the outside to enable a safety and storage cap to screw onto the top of housing unit 105 , and the bottom of housing unit 105 is threaded on the inside to enable a bottom plug 130 to screw into the bottom of housing unit 105 . When threaded bottom plug 130 is threaded into the bottom of housing unit 105 , it secures compression spring 140 in place.
Bottom plug 130 is preferably made of aluminum with all surfaces eased for safety. Bottom plug 130 has ¼ of an inch of knurled surface for gripping to secure tightening and is threaded at the other end to match threads on the bottom of housing unit 105 in order to tighten into housing unit 105 . In alternate embodiments, the bottom plug may be made of various different materials such as, but not limited to, different types of metal, plastic or rubber and may be attached to the bottom of the housing unit using various different means including, but not limited to, welding, set screws, friction, etc. In the present embodiment, bottom plug 130 has a small hole drilled through its center to release any water that may become trapped in housing unit 105 to generally prevent water damage. Bottom plug 130 holds compression spring 140 in housing unit 105 . In the present embodiment, flag assembly 100 also has a cap 145 at the top of housing unit 105 as a safety device when not in use to generally prevent injury that may be caused by hitting the top of housing unit 105 . Safety cap 145 is preferably made of aluminum and is used when mounting and removing flag assembly 100 to and from a boat. Safety caps in alternate embodiments may be made of various different materials such as, but not limited to, other metals, plastic, rubber, etc. In the present embodiment, safety cap 145 has threads cut into it to match threads cut at top of housing unit 105 and has a medium knurled outside surface for easy installation. Safety cap 145 prevents flag 115 from popping out of housing unit 105 if someone releases trigger lever 125 from its locked, retracted position, such as, but not limited to, when flag assembly 100 is being installed or is in storage. Safety cap 145 may be attached to the top of housing unit 105 using various different means such as, but not limited to, set screws, friction, etc. Safety cap 145 may also be used when the boat is not in use to keep water out of housing unit 105 . Some embodiments of the present invention may not include a safety cap.
In the present embodiment, flag assembly 100 is attached to a bimini top of a boat with a clamp 135 . Clamp 135 comprises two sides that are bolted together to create one single clamp. Clamp 135 is preferably made of aluminum and is 3½ inches long by 1 inch wide. Clamp 135 has all edges cut at 45-degree angles to prevent sharp edges. The two sides of clamp 135 are held together with a seven-lobe knob with a threaded stud built into the knob that is screwed into a hole drilled through the center of each side of clamp 135 ; however the two pieces of clamp 135 may be held together using various different means such as, but not limited to, bolts, screws, etc. When bolted together, there is a hole at one end of clamp 135 that fits around housing unit 105 and a hole at the other to fit and around the railing of the bimini cover of the boat. In alternate embodiments the clamp may be sized to fit on various different locations on the boat such as, but not limited to, a ski pylon, ski tower, etc. In other alternate embodiments, the flag assembly may be attached to the boat using various different types of clamps or other attachment means such as, but not limited to, welding, rope, straps, bolts, screws, brackets, etc. In the present embodiment, flag assembly 100 is shown with one clamp 135 ; however, more clamps may be used to attach flag assembly 100 to the boat for example, without limitation, one at the top of housing unit 105 and one at the bottom of housing unit 105 for stability, as shown by way of example in FIG. 4 . Clamp 135 can slide anywhere along housing unit 105 and anywhere on the boat bimini top or elsewhere on the boat to suit the boat and the preference of the user.
Flagpole 120 is preferably 5/16 of an inch round by 28½ inches in length and is rounded on the end. Flagpole 120 is preferably made of aluminum. In alternate embodiments the flagpole may be various different sizes and may be made of various different materials including, but not limited to, different types of metal or plastic. In the present embodiment, flagpole 120 slides into an upper guide and the lower guide in housing unit 105 , which help flagpole 120 move smoothly between the upright position and the retracted position. Flagpole 120 holds 12-inch-by-12-inch flag 115 , which may be glued, sewn or otherwise attached to flagpole 120 to remain in place when moving between the upright and retracted positions.
Flagpole 120 is extended from the retracted position to the upright position by compression spring 140 . Compression spring 140 is preferably made of stainless steel; however, various other metals may be used. Compression spring 140 is inserted into the bottom of housing unit 105 and stops against the lower guide on flagpole 120 . Then, bottom plug 130 is screwed into the bottom of housing unit 105 to keep compression spring 140 in place. When trigger lever 125 is removed from the safety lock, flag 115 pops out of the top of housing unit 105 due to the force of the expansion of compression spring 140 . When trigger lever 125 is pressed down, spring 140 compresses until trigger lever 125 is slid into the safety lock and is ready to release and pop flag 115 out of housing unit 105 again. Compression spring 140 is strong enough to enable flag 115 to fully extend while not being overly powerful so it operates smoothly and efficiently. An alternate embodiment of the present invention may be implemented without a compression spring. In this embodiment a user manually slides the trigger lever attached to the flagpole up into the upright position and back down into the retracted position. This embodiment comprises a second safety lock at the top of the slot in the housing unit into which the trigger lever is inserted to hold the flagpole in the upright position.
In the present embodiment, almost the entire structure of flag assembly 100 is made from aluminum to resist water damage and to promote a longer life, in addition to being attractive. However in alternate embodiments, some or all of the parts may be made from different materials, for example, without limitation, different metals or plastic.
In typical use of the present embodiment, a user attaches flag assembly 100 to a boat using clamp 135 . Trigger lever 125 is pushed down into the safety lock to lock flag 115 in the retracted position. As a skier or tuber participates in a water sport while connected to the boat, flag 115 remains in the retracted position. If the skier or tuber falls into the water, the user removes trigger lever 125 from the safety lock and compression spring 140 forces flagpole 120 and flag 115 up and out of housing unit 105 by pressing against the lower flagpole guide. Once the skier or tuber is safely out of the water, the user pushes trigger lever 125 back down into the safety lock to pull flagpole 120 and flag 115 back into housing unit 105 and into the retracted position.
FIG. 2 is a diagrammatic side view of an exemplary flag 115 for a retractable caution flag assembly, in accordance with an embodiment of the present invention. In the present embodiment, flag 115 is 12 inches by 12 inches in size when installed on a flagpole and is orange in color to meet legal requirements. Flag 115 is preferably made of polyester nylon material; however other materials may be suitable such as, but not limited to, cotton, silk or plastic. Flag 115 has a 1¼-inch overhang 205 , which is rolled over and sewn down the length of flag 115 . This creates a pocket into which the flagpole may be inserted for installation. Flag 115 may be glued or otherwise adhered to the flagpole to generally ensure stability when flag 115 is in motion. The rest of the material creating flag 115 is cut in a radius to better fit inside the housing unit while not in operation; however, in alternate embodiments the flag may have a different shape such as, but not limited to, a square, a rectangle, a triangle, etc. Those skilled in the art, in light of the present teachings, will readily recognize that alternate embodiments of the present invention may be implemented for purposes other than a water safety caution flag such as, but not limited to, other types of signal flags on boats, flags in other sporting events, road construction flags, etc. In these alternate embodiments the flag may be virtually any size, shape or color.
FIGS. 3A and 3B illustrate an exemplary lower flagpole guide 305 for a retractable caution flag assembly, in accordance with an embodiment of the present invention. FIG. 3A is a diagrammatic top view, and FIG. 3B is a diagrammatic side view. In the present embodiment, lower flagpole guide 305 is preferably made of aluminum with all edges cut at 45 degree angles for smother operating; however, lower flagpole guide 305 may be made of various different materials including, but not limited to, other types of metal, plastic, rubber, etc. It is lower flagpole guide 305 into which the trigger lever screws in order to move the flagpole up and down. Lower flagpole guide 305 is sized to fit inside the housing unit and has hole 310 in the center into which the flagpole can be inserted. Lower flagpole guide 305 has two ⅛-inch holes 315 and a ¼-inch, threaded hole 320 drilled into its side. Holes 315 are designed so that when flagpole 120 is first inserted into hole 310 , flagpole 120 can be drilled with a ⅛″ bit through holes 315 and ⅛″roll-pins can be inserted into holes 315 to lock flag pole to guide 305 . The trigger lever screws into hole 320 in order to operate the flagpole. In alternate embodiments, the trigger lever may be attached to the lower flagpole guide using various different means such as, but not limited to, welding, bolts, screws, etc. In the present embodiment, lower flagpole guide 305 is set at the bottom of the flagpole and a ⅛-inch stainless steel roll pin is inserted through one of holes 315 to hold lower flagpole guide 305 in place. In alternate embodiments the lower flagpole guide may be held in place on the flagpole using various different means including, but not limited to, welding, set screws, etc. In the present embodiment, an upper flagpole guide similar to lower flagpole guide 305 without a hole for the trigger lever is located 13 inches from the top end of the flagpole. The upper flagpole guide may be located in different places on the flagpole depending on factors such as, but not limited to, the size of the flagpole, the size of the flag, etc. Furthermore, alternate embodiments of the present invention may be implemented without an upper guide on the flagpole or with more than two flagpole guides. The upper and lower flagpole guides help the flagpole move between the upright position and the retracted position smoothly. However, those skilled in the art, in light of the present teachings, will readily recognize that various other means may be used to accomplish this such as, but not limited to, roller bearings. Some alternate embodiments may be implemented without flagpole guides of any type. In these embodiments the trigger lever is attached directly to the flagpole and the flagpole fits snuggly inside the housing unit while still being able to slide up and down. Lubricants may be used in these embodiments to aid in the movement of the flagpole within the housing unit.
FIG. 4 is a diagrammatic side view of an exemplary caution flag assembly 100 mounted to a boat 400 , in accordance with an embodiment of the present invention. In the present embodiment, flag assembly 100 is attached to a bimini top 405 of boat 400 with two clamps 135 . However, users of embodiments of the present invention can easily mount the assembly to their boats wherever they want, making embodiments of the present invention more attractive to more people.
Those skilled in the art, in light of the present teachings, will readily recognize that alternate embodiments of the present invention may enable the user to raise and lower the flag using means other than a spring-loaded mechanism. For example, without limitation, one alternate embodiment may be implemented with a push button mechanism rather than a manual trigger. Other alternate embodiments may be motorized versions of the flagpole assembly. Yet another alternate embodiment may comprise a screw type flagpole with a worm gear.
Having fully described at least one embodiment of the present invention, other equivalent or alternative methods of providing a retractable caution flag according to the present invention will be apparent to those skilled in the art. The invention has been described above by way of illustration, and the specific embodiments disclosed are not intended to limit the invention to the particular forms disclosed. For example, the particular implementation of the flag assembly may vary depending upon the particular type of mounting object being used. The flag assemblies described in the foregoing were directed to boat-mounted implementations; however, similar techniques are to mount retractable caution flags on different types of objects. For example, without limitation, retractable flags may be mounted to construction vehicles at a worksite or traffic signals or signs. Retractable flags may also be mounted to various types of sporting equipment for example, without limitation, a soccer or hockey goal to indicate when a player scores or the finish line of a race to indicate when a racer finishes. Non boat-mounted implementations of the present invention are contemplated as within the scope of the present invention. The invention is thus to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the following claims.
Claim elements and steps herein have been numbered and/or lettered solely as an aid in readability and understanding. As such, the numbering and lettering in itself is not intended to and should not be taken to indicate the ordering of elements and/or steps in the claims.
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An apparatus includes a housing unit having a hollow cylinder shape with a longitudinal slot and a short section of slot situated at a right angle to the longitudinal slot. A flagpole is inserted into the housing unit for movement within the housing unit, where the flagpole is completely contained within the housing unit at a first position. A lower guide is joined to the flagpole for guiding movement of the flagpole. A caution flag is joined to the flagpole proximate a flagpole end. At least one bracket assembly joins the apparatus to a vehicle. A compressible spring is disposed within the housing unit for driving the flagpole in a first direction to a second position to display the flag. A trigger lever extends through the longitudinal slot where a placement of the trigger lever in the short section of slot prevents the compressible spring from moving the flagpole.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a hydraulic circuit for a working machine, such as a crushing machine, that has an attachment to which working devices are selectively attached.
2. Description of the Related Art
A typical crushing machine includes a base machine and an attachment which is mounted on the base machine and to which working devices, such as a compression crusher and a breaker, are selectively attached at an end of the attachment depending on the kind of work to be performed. In the following description, work using the breaker is called breaking.
In this case, the compression crusher and the breaker use different hydraulic actuators, and the actuators must be provided with respective oil supply/discharge passages. Accordingly, a hydraulic circuit must be switched depending on the kind of the working device to be used.
FIGS. 6A and 6B are diagrams illustrating a structure in which the circuit is switched manually. FIG. 6A shows a circuit state for compression crushing and FIG. 6B shows a circuit state for breaking.
Referring to FIGS. 6A and 6B , the structure includes a hydraulic pilot-operated directional control valve 5 operated by a remote control valve 6 , a manual directional control valve (three-way valve) 7 , a hydraulic pump 8 that functions as a hydraulic power source for actuators, a tank T, and a primary hydraulic power source 11 for the remote control valve 6 . When the control valve 5 is operated, oil is supplied from the hydraulic pump 8 to a compression-crusher cylinder 9 or a breaker cylinder 10 , and the compression-crusher cylinder 9 or the breaker cylinder 10 is operated accordingly.
As shown in FIG. 6A , when compression crushing is performed, similar to a double acting cylinder circuit, input and output ports of the compression-crusher cylinder 9 are connected to the hydraulic pump 8 and the tank T via the control valve 5 .
When breaking is performed, the power of the breaker is reduced if a back pressure is applied to a return line of the breaker cylinder 10 due to a throttle effect of the control valve 5 , and there is a risk that the breaker cannot be operated. In addition, pulsation occurs in an oil cooler (not shown) and there is risk that the oil cooler will be damaged.
Therefore, as shown in FIG. 6B , when breaking is performed, the directional control valve 7 is operated so that the return line of the breaker cylinder 10 is directly connected to the tank T.
A technique for automatically switching the circuit state with a directional valve depending on the kind of the working device without using the manual directional control valve 7 shown in FIGS. 6A and 6B is disclosed in Japanese Unexamined Patent Application Publication No. 2002-294758.
Also in this case, there is a risk that a fail, such as a breakage of a line connecting a controller and a solenoid valve or a breakdown of the controller, will occur in an electrical or hydraulic control system of the directional control valve that functions as an automatic control device. Accordingly, there is a possibility that the circuit state expected by the operator and the actual circuit state do not match.
Therefore, the following problems occur:
(i) If the actual circuit state is set to the state for compression crushing even though breaking (circuit state for breaking) is selected by a mode switch operation performed by the operator and breaking is performed, the back pressure in the return line is increased as described above and there is a risk that the power of the breaker will be reduced or the breaker will stop.
(ii) If the actual circuit state is set to the state for breaking even though compression crushing (circuit state for compression crushing) is selected by the operator and compression crushing is performed, the compression-crusher cylinder cannot be reciprocated and operates in only one direction since one of the lines of the cylinder is directly connected to the tank.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide a hydraulic circuit for a working machine that performs a fail-safe function when actual and expected circuit states do not match.
According to the present invention, a hydraulic circuit for a working machine basically has the following structure.
That is, according to an aspect of the present invention, a hydraulic circuit for a working machine including a base machine and an attachment mounted on the base machine includes a controller that generates a signal depending on a selecting operation performed by an operator; hydraulic actuators for driving respective working devices, the hydraulic actuators being driven by a drive circuit having two kinds of circuit states that correspond to the working devices; a directional control valve unit which, when one of the working devices is attached to the attachment, switches in response to the signal from the controller to select one of the two kinds of circuit states; a detector for detecting the actual circuit state; and a display activated by the controller. The controller activates the display when the actual circuit state detected by the detector and the selected circuit state do not match.
When the circuit state expected by the operator and the actual circuit state do not match, the display is activated to inform the operator of the discrepancy. Accordingly, a fail-safe function is provided when the operator informed of the discrepancy stops the operation.
In a hydraulic circuit for a working machine according to another aspect of the present invention, working devices driven by different hydraulic actuators are selectively attached to an attachment mounted on a base machine, the hydraulic actuators being driven by a drive circuit having two kinds of circuit states that correspond to the working devices. A directional control valve unit selects one of the circuit states by switching in response to a signal generated by a controller depending on a selecting operation performed by an operator. The hydraulic circuit has the following features:
(A) A hydraulic pilot-operated directional control valve that functions as a common control valve for controlling the operation of the hydraulic actuators for driving the working devices and that is operated by a remote control valve is provided.
(B) The directional control valve unit includes a hydraulic pilot-operated main directional control valve that switches depending on whether a pilot pressure is supplied or shut off to generate the two kinds of circuit states and first and second solenoid valves that are selectively operated on the basis of an electric signal from a control means.
(C) Each of the solenoid valves is connected to the pilot hydraulic power source and applies a pilot pressure from the pilot hydraulic power source to the main directional control valve when the solenoid valve is operated.
(D) The pilot pressure from the pilot hydraulic power source is supplied to the remote control valve that operates the common control valve as a primary pressure when the solenoid valves are operated.
In this structure, when the solenoid valves included in the directional control valve unit are activated, the pilot pressure from the pilot hydraulic power source is supplied to the remote control valve via the directional control valve unit as the primary pressure. Therefore, if an abnormality like a breakage of electric lines connecting the controller to the solenoid valves occurs and the solenoid valves cannot be operated, the supply of the primary pressure to the remote control valve stops.
Therefore, the common control valve cannot be operated even when the remote control valve is operated (or the common control valve returns to neutral if the common control valve is being operated). As a result, the operation of the hydraulic actuator is automatically stopped and thus the fail-safe function is provided.
In addition, since the solenoid valves included in the directional control valve unit are used to shut off the primary pressure of the remote control valve, the structure is simpler than that in the case in which, for example, an additional solenoid shutoff valve is provided at a primary side of the remote control valve and the shutoff valve is operated when a fail is detected.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a diagram illustrating a circuit structure according to a first embodiment of the present invention;
FIG. 2 is a diagram illustrating a circuit structure according to a second embodiment of the present invention;
FIG. 3 is a diagram illustrating a circuit structure according to a third embodiment of the present invention;
FIG. 4 is a schematic side view of a crushing machine in which an opening/closing compression crusher is attached to an attachment;
FIG. 5 is a schematic side view of the crushing machine in which a breaker is attached to the attachment; and
FIGS. 6A and 6B are diagrams illustrating the structure of a circuit that is switched with a manual directional control valve, where FIG. 6A shows a circuit state for compression crushing and FIG. 6B shows a circuit state for breaking.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 4 and 5 illustrate a crushing machine including a hydraulic excavator as a base body and a hydraulic circuit for a working machine according to the present invention.
The crushing machine includes a crawler type base machine 1 and a bendable attachment 2 mounted on the base machine 1 . In the embodiments described below, an opening/closing compression crusher 3 (see FIG. 4 ) called a nibbler and a vibrating breaker 4 (see FIG. 5 ) are explained as examples of working devices.
The opening/closing compression crusher 3 called a nibbler or the vibrating breaker 4 is attached to an end of the attachment 2 as a working device depending on the kind of work to be performed.
In this case, the compression crusher 3 and the breaker 4 use different hydraulic actuators, and the actuators must be provided with respective oil supply/discharge passages. Accordingly, a hydraulic circuit must be switched depending on the attached working device.
Hydraulic circuits for working machines according to embodiments of the present invention that provide a fail-safe function will be described below with reference to the accompanying drawings.
First Embodiment (see FIG. 1 )
Referring to FIG. 1 , a directional control valve unit 18 includes a hydraulic pilot-operated main directional control valve 19 that switches between a compression-crushing position a and a breaking position b and a solenoid valve 20 that switches the main valve 19 on the basis of an electric signal from a controller 21 that functions as control means. The solenoid valve 20 switches between a position y for supplying a pilot pressure to the main valve 19 and a position x for shutting off the pilot pressure on the basis of the electric signal from the controller 21 .
According to the present invention, detecting means detects the switch state of the main valve 19 as the actual circuit state. Preferably, the detecting means is structured such that the main valve 19 included in the directional control valve unit 18 has a pressure port connected to a hydraulic power source at one end of the main valve 19 and a pressure sensor is connected to the pressure port. The detecting means may include, for example, a pressure sensor 23 which will be described below.
In this case, since the state of the main valve 19 included in the directional control valve unit 18 is detected as the actual circuit state, the structure of the detecting means can be made simple. In particular, when the pressure sensor 23 is used, the pressure sensor 23 simply detects whether or not a pressure is applied to the pressure port of the main valve 19 . Therefore, the detecting means is small and inexpensive, and can easily be installed in the circuit.
The basic structure and operation (circuit-state-switching operation) performed by the directional control valve unit 18 will be described below.
The solenoid valve 20 switches between the compression-crushing position x at which the pilot pressure of a pilot hydraulic power source 16 is not supplied to a pilot port 19 a of the main valve 19 (that is, for connecting the port 19 a to a tank T) and the breaking position y at which the pilot pressure is supplied to the pilot port 19 a. In this structure, when a mode switch 17 as a switch for changing modes is switched to compression-crushing, the controller 21 does not transmit the electric signal to the solenoid valve 20 . Therefore, the solenoid valve 20 and the main valve 19 are switched to the compression-crushing positions x and a, respectively, as shown in FIG. 1 .
Accordingly, lines of the compression-crusher cylinder 9 are connected to a hydraulic pump 8 and the tank T via a control valve 5 (circuit state for compression crushing).
When the mode switch 17 is switched to breaking, the controller 21 transmits the electric signal to the solenoid valve 20 so that the solenoid valve 20 switches to the breaking position y. Therefore, the main valve 19 also switches to the breaking position b.
Accordingly, the return line of the breaker cylinder 10 is directly connected to the tank T without passing through the control valve 5 (circuit state of for breaking).
In the first embodiment, the main valve 19 included in the directional control valve unit 18 has a sub-spool 22 that moves together with a spool (main spool) of the main valve 19 .
The sub spool 22 has input and output ports 22 a and 22 b and a tank port 22 c.
The input port 22 a is connected to the pilot hydraulic power source 16 and the tank port 22 c is connected to the tank T. When the main valve 19 is switched from the compression-crushing position a shown in the figure to the breaking position b, the input and output ports 22 a and 22 b communicate with each other and the pressure of the pilot hydraulic power source 16 is supplied to the output port 22 b.
The output port 22 b is connected to the pressure sensor 23 and the pressure sensor 23 outputs a signal to the controller 21 .
Accordingly, whether the main valve 19 is at the compression-crushing position a or the breaking position b, that is, the actual circuit state, can be detected on the basis of whether or not the pressure is applied to the output port 22 b.
In addition, the controller 21 is connected to a display (lamp, buzzer, etc.) 24 that functions as display means. As is clear from the fact that a buzzer is mentioned as an example of the display 24 , the display 24 is not limited to a visual display that can be presented on a screen or the like. For example, other means for attracting an attention, such as an alarm, may also be used as the display 24 as long as the operator can be informed of the actual circuit state by the activated display 24 .
The controller 21 compares the signal from the pressure sensor 23 that represents the actual circuit state with an operation signal of the mode switch 17 that represents the circuit state expected by the operator. If the two signals do not match, that is, when the circuit is set for breaking even through compression crushing is selected by the operator or when the circuit is set for compression crushing even through breaking is selected by the operator, the display 24 is activated.
Thus, when an abnormality like a line breakage occurs in a control system of the directional control valve unit 18 , the operator can be informed of the situation by the display. Accordingly, the operator can stop the operation of the control valve 5 so that various troubles caused by the discrepancy between the expected and actual circuit states can be avoided.
In the above-described structure, a pressure switch may be used instead of the pressure sensor 23 .
Second Embodiment (see FIG. 2 )
In the first embodiment, the display is activated when the expected and actual circuit states do not match. In comparison, in a second embodiment, the operation of a compression-crusher cylinder 9 or a breaker cylinder 10 is stopped automatically when an abnormality occurs.
According to the second embodiment, a directional control valve unit 25 includes a hydraulic pilot-operated main directional control valve 19 and first and second solenoid valves 26 and 27 for breaking and compression crushing, respectively, that are selectively operated by an electric signal transmitted from a controller 28 in accordance with the operation of a mode switch 17 .
The solenoid valves 26 and 27 are both connected to a pilot hydraulic power source 16 . When the first solenoid valve 26 is operated, a pilot pressure of the pilot hydraulic power source 16 is supplied to a pilot port 19 a of the main valve 19 so that the main valve 19 is switched from a compression-crushing position a to a breaking position b.
In addition, when the solenoid valves 26 and 27 are operated, the pilot pressure is output from output ports thereof and is supplied to a remote control valve 6 for controlling a control valve 5 via a shuttle valve 29 as a primary pressure.
In this structure, when the solenoid valves 26 and 27 are operated normally, the primary pressure is supplied to the remote control valve 6 via the operated solenoid valve 26 or 27 . Accordingly, the control valve 5 is switched in accordance with the operation of the remote control valve 6 and the compression-crusher cylinder 9 or the breaker cylinder 10 is operated.
However, if an abnormality like a breakage of electric lines connecting the controller 28 to the solenoid valves 26 and 27 occurs and the solenoid valves 26 and 27 cannot be operated, the supply of the primary pressure to the remote control valve 6 stops.
More specifically, if an abnormality occurs while breaking is selected, the first solenoid valve 26 cannot be operated and the pilot pressure is not output from the solenoid valve 26 . Therefore, the primary pressure of the remote control valve 6 is shut off.
Similarly, if an abnormality occurs while compression crushing is selected by the mode switch 17 , the second solenoid valve 27 cannot be operated. Therefore, also in this case, the primary pressure of the remote control valve 6 is shut off.
Accordingly, the control valve 5 cannot be operated even when the remote control valve 6 is operated (or the control valve 5 returns to neutral if the control valve 5 is being operated). As a result, the compression-crusher cylinder 9 or the breaker cylinder 10 is automatically stopped, and thus the fail-safe function is provided.
According to the present embodiment, the solenoid valves 26 and 27 included in the directional control valve unit 25 are used to shut off the primary pressure of the remote control valve 6 . Therefore, the structure is simpler than that in the case in which, for example, an additional solenoid shutoff valve is provided at a primary side of the remote control valve 6 and the shutoff valve is operated when a fail is detected.
Thus, according to the present embodiment, operation-stopping means for stopping the operation of the compression-crusher cylinder 9 or the breaker cylinder 10 , which functions as a hydraulic actuator, is provided. The controller 28 that functions as control means causes the operation-stopping means to stop the operation of the compression-crusher cylinder 9 or the breaker cylinder 10 when the actual circuit state and the selected circuit state do not match.
Thus, when the actual and selected circuit states do not match, the operation of the compression-crusher cylinder 9 or the breaker cylinder 10 can be automatically stopped by the operation-stopping means in addition to activating a display. Accordingly, the reliability of the fail-safe function can be increased. In addition, when the display and automatic stopping are performed simultaneously, the operator can reliably recognize the discrepancy between the expected and actual circuit states (occurrence of a fail). Therefore, recognition of the cause and repair can be facilitated.
Third Embodiment (see FIG. 3 )
In the third embodiment, the display function described in the first embodiment and the automatic stopping function described in the second embodiment are both performed when an abnormality occurs.
More specifically, the circuit structure according to the first embodiment is basically applied, and an additional solenoid shutoff valve 30 is provided at a primary side of a remote control valve 6 . In this case, when the actual and expected circuit states do not match, in addition to activating a display 24 , the shutoff valve 30 is activated by a signal from a controller 21 so that the primary pressure of the remote control valve 6 is shut off.
Accordingly, since the display 24 is activated and the operation of a hydraulic actuator (a compression-crusher cylinder 9 or a breaker cylinder 10 ) is automatically stopped simultaneously, the reliability of the fail-safe function can be increased. In addition, since the automatic stopping and display are simultaneously performed, the operator can reliably recognize the discrepancy between the expected and actual circuit states (occurrence of a fail). Therefore, recognition of the cause and repair can be facilitated.
In the above-described embodiments, the compression crusher and the breaker are explained as examples of working devices that can be selectively attached. However, other various combinations of devices can be applied as long as the devices are driven by different hydraulic actuators and it is necessary to switch the circuit state depending on the actuator to be used.
Although the invention has been described with reference to the preferred embodiments in the attached figures, it is noted that equivalents may be employed and substitutions made herein without departing from the scope of the invention as recited in the claims.
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A hydraulic circuit for a working machine includes hydraulic actuators which respectively drive a plurality of kinds of working devices and which are driven by a drive circuit having circuit states that correspond to the working devices, a directional control valve unit which, when one of the working devices is attached to the attachment, switches in response to a signal from a controller to select one of the circuit states, a detection sensor that detects the actual circuit state, and a display operated by the controller. The controller activates the display when the detected actual circuit state and the selected circuit state do not match.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of U.S. patent application Ser. No. 12/113,865 filed May 1, 2008, entitled “Thulium and/or Holmium Doped Silicate Glasses for Two Micron Lasers” to Shibin Jiang and claims priority under 35 U.S.C. §120 to the same. U.S. patent application Ser. No. 12/113,865 is hereby incorporated by reference herein.
FIELD OF THE INVENTION
This invention relates to glasses and fibers for laser applications. More specifically, this invention is directed to Thulium-doped, Holmium-doped, and Thulium/Holmium co-doped germanosilicate glasses for near 2 micron fiber lasers with high quantum efficiency.
BACKGROUND OF THE INVENTION
Near 2 micron fiber lasers are of great interest because of the potential possibility of combining high output power and retina safety together, which are needed for a wide variety of commercial and military applications including materials process, remote sensing, and bio-medical application. Due to the stronger absorption of many materials containing water molecules and organic materials at 2 micron than at 1 micron, less power of 2 micron fiber laser is needed compared to 1 micron fiber laser in order to achieve the same effect. More importantly, 2 micron is classified as retina safe wavelength (frequently called as eye-safe laser), which is much safer than 1 micron laser. Up to now, majority of the high power fiber laser development focus on 1 micron Yb 3+ -doped fiber laser.
SUMMARY OF THE INVENTION
Considering the inherent critical drawbacks associated with silica and germanate glass fibers, Applicants have prepared highly Tm 3+ -doped, Ho 3+ -doped, and Tm 3+ /Ho 3+ -doped germanosilicate glass fiber for 2 micron fiber laser application. By “germanosilicate glass,” Applicants mean multi-component glass with a first network former of SiO 2 and a second network former of GeO 2 . In contrast to silica glass, germanosilicate glass contains glass network modifiers such as alkali ions and alkaline metal ions, and glass network intermediates such as aluminum oxide and boron oxide in addition to glass network formers of SiO 2 and GeO 2 . In most cases, the content of SiO 2 is not higher than 70 mole percent and the content of GeO 2 is not higher than 70 mole percent in germanosilicate glasses.
Applicants have found that high concentration of rare-earth oxides can be doped into silicate and germanosilicate glasses without the so-called ion-clusters mainly because of the glass network modifiers. The glass network modifiers, such as sodium ions, potassium ions, barium ions, and calcium ions, break the well-defined glass network of silica, thereby producing sites for rare-earth ions. Applicants have found that silicate and germanosilicate glass fiber exhibits numerous advantages over silica fiber, germanate glass fiber and other multi-component glass fibers as the host for highly efficient and high power fiber laser near 2 microns.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood from a reading of the following detailed description taken in conjunction with the drawings in which like reference designators are used to designate like elements, and in which:
FIG. 1A illustrates absorption spectra of Tm 3+ -doped germanosilicate glasses with different doping concentrations;
FIG. 1B illustrates absorption spectra of Tm 3+ /Ho 3+ co-doped germanosilicate glasses with different doping concentrations;
FIG. 1C illustrates absorption spectra of Ho 3+ -doped germanosilicate glasses with different doping concentrations;
FIG. 2 illustrates thermal expansion curves of Tm 3+ -doped germanosilicate glass;
FIG. 3 illustrates laser performance of Tm-doped germanosilicate glass fiber;
FIG. 4 shows a cross section view of single cladding Tm 3+ -doped germanosilicate glass fiber;
FIG. 5 shows a cross section view of on off-center single cladding Tm 3+ -doped germanosilicate glass fiber;
FIG. 6 shows a cross section view of doubling cladding Tm 3+ -doped germanosilicate glass fiber;
FIG. 7 shows a cross section view of on off-center double cladding Tm 3+ -doped germanosilicate glass fiber;
FIG. 8 is a block diagram showing Applicants' apparatus used for fiber laser characterization; and
FIG. 9 illustrates laser performance of Tm/Ho co-doped germanosilicate glass fiber.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
This invention is described in preferred embodiments in the following description with reference to the Figures, in which like numbers represent the same or similar elements. Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.
The described features, structures, or characteristics of the invention may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are recited to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the invention.
Near 2 micron fiber lasers can be generated from Tm 3+ -doped, Ho 3+ -doped, and Tm 3+ /Ho 3+ -co-doped fibers. The laser wavelengths can vary from 1.8 micron to 2.2 micron, which is generally called 2 micron fiber laser. Tm 3+ -doped and Tm 3+ /Ho 3+ -co-doped fibers can be used to generate near 2 micron fiber lasers because diode lasers near 800 nm can be used as a pump source. In some cases pump lasers from 1.5 micron to 1.9 micron are used to excite the active rare-earth ions from the ground state to the lasing state, which is called in-band pumping. When a near 800 nm laser is used as pump source, the quantum efficiency can be close to 200% because of the so-called cross-relaxation process of Tm 3+ ions.
Tm 3+ cross-relaxation is a non-radiative process which occurs when the Tm 3+ doping concentration is sufficiently high in which an excited Tm 3+ in the 3 H 4 level decays to the 3 F 4 level and a neighboring ground-state Tm 3+ ion is excited to the 3 F 4 level, accompanied by the emission of phonons. In Tm 3+ doped crystals the probability of Tm 3+ cross relaxation is negligible for concentration less than about 2 weight percent but approaches unity for concentrations greater than about 5 weight percent.
The cross-relaxation process has been observed in Tm 3+ -doped silica fiber when the doping concentration is at least 2.2 weight percent, resulting in a quantum efficiency of 120%, and in Tm 3+ -doped germanate fiber when the doping concentration is at least a 4 weight percent, resulting in a quantum efficiency of 170%. Additionally, highly efficient fiber lasers have been demonstrated using either Tm 3+ -doped silica or germanate fiber by taking advantage the cross-relaxation of Tm 3+ ions. For example, by using Tm 3+ -doped germanate glass fiber, a 2 μm fiber laser with more than 100 W output power and 68% slope efficiency has been demonstrated.
However, both Tm 3+ -doped silica fiber and Tm 3+ -doped germanate fiber suffer many problems for practical fiber laser applications. For Tm 3+ -doped silica fiber specifically, the doping concentration of Tm 3+ ions is restricted to around 2.2 weight percent of Tm 2 O 3 due to the intrinsic glass network structure, which limits the benefit of cross-relaxation of Tm 3+ ions. As a result, the efficiency is relatively low. Various approaches have been developed to increase the doping concentration, including co-doping with Al 2 O 3 , B 2 O 3 , and P 2 O 5 and using nano-particles, however, the highest doping levels achieved are still far below the 4 to 6 weight percent required for efficient cross-relaxation energy transfer of Tm 3+ ions.
Applicants have discovered that germanosilicate glass provides significant advantages over silica glass, including that high Tm 3+ doping concentrations of rare-earth ions can be achieved in germanosilicate glass due to its less defined glass network, which enables the maximum benefit of cross-relaxation energy transfer. More specifically, Applicant has achieved Tm 3+ doping concentrations of about 2 weight percent to about 15 weight percent using germanosilicate glass. Moreover, Applicants have discovered that a quantum efficiency near 200% can be achieved when Tm 3+ -doped germanosilicate fiber laser is pumped with near 800 nm laser diodes. Such high quantum efficiency results in a high slope efficiency and relatively small amount of heat.
Another significant advantage of germanosilicate glass over silica glass is that the phonon energy of germanosilicate near 950 cm −1 is much smaller than that of near 1100 cm −1 of silica glass. A lower phonon energy is beneficial for achieving high laser efficiency for near 2 micron fiber lasers.
Germanosilicate glass also has advantages over germanate glass, including increased mechanical and chemical strength. As will be appreciated, silicate glasses and germanate glasses comprise different glass network formers. As the bond strength of Si—O is stronger than that of Ge—O, the mechanical strength of silicate glasses typically is logically stronger than germanate glasses, and the coefficient of thermal expansion of silicate glasses is smaller. As will be appreciated, the smaller the coefficient of thermal expansion, the higher the thermal shock resistance. Furthermore, a higher thermal shock resistance and a stronger mechanical strength yields a higher pump heat induced damage threshold and laser induced damage threshold, which are critical in order to achieve high fiber laser power.
Applicants have also found that using germanosilicate glass provides numerous advantages when co-doped with Tm 3+ /Ho 3+ or when doped with Ho 3+ alone. As mentioned, a high Tm 3+ doping concentration can produce efficient pump absorption near 800 nm and when co-doped with Ho 3+ , the Tm 3+ transfers energy to Ho ions. In certain preferred embodiments, when Tm 3+ /Ho 3+ are co-doped, the Tm 3+ doping concentration is higher that Ho 3+ doping concentration. In yet other embodiments however, the Ho 3+ doping concentration is higher or the doping concentration of the Tm 3+ and the Ho 3+ are the same. For embodiments doped with Ho 3+ only, a relatively high Ho doping concentration is very important as well in order to achieve a relatively high gain per unit length near 2 micron.
For all three embodiments, Tm 3+ -doped, Tm 3+ /Ho 3+ co-doped, and Ho 3+ -doped germanosilicate glass, the expected laser wavelength is near 2 micron. For near 2 micron fiber laser a relatively lower phonon energy can produce a higher quantum efficiency, which means germanosilicate glass has a clear advantage over silica glass.
Applicants' present invention utilizes a glass host of germanosilicate glass. Germanosilicate glass is a glass having two network formers, one being SiO 2 and the other being GeO 2 . As will be appreciated, the network structure of glass allows for the accommodation of different types of atoms which can significantly change the properties of the glass. Cations can act as network modifiers, disrupting the continuity of the network, or as formers, which contribute to the formation of the network. Network formers have a valence greater than or equal to three and a coordination number not larger than four. Network intermediates have a lower valence and higher coordination number than network formers. Applicants' germanosilicate glass host maintains the superior mechanical and chemical strength of silicate glass while having the similar phonon energy of germanate glass.
In certain embodiments, Applicants' germanosilicate glass host comprises from about 2.5 mole percent to about 70 mole percent SiO 2 and from 2.5 mole percent to about 70 mole percent GeO 2 , where the total mole percent of the SiO 2 and GeO 2 is from about 30 mole percent to about 90 mole percent. In certain other embodiments, Applicants' germanosilicate glass host comprises from about 2.5 mole percent to about 50 mole percent SiO 2 and from 4.25 mole percent to about 60 mole percent GeO 2 , where the total mole percent of the SiO 2 and GeO 2 is from about 45 mole percent to about 70 mole percent.
Using Applicants' germanosilicate glass host, Applicants have designed and fabricated a series of germanosilicate glasses which exhibit good rare-earth solubility and thermal properties. The Si—O and Ge—O bonds which form the glass host matrix can be perturbed using one or more Network Modifiers (“MO”). Generally speaking, Network Modifiers affect, inter alia, the thermal expansion, hardness, chemical durability, density, surface tension, and refractive index, of a pure germanosilicate glass. In certain embodiments, Applicants' germanosilicate glass host is modified using one or more MO materials selected BaO, CaO, MgO, ZnO, PbO, K 2 O, Na 2 O, Li 2 O, Y 2 O 3 , or combinations thereof, from 5 mole percent to 40 mole percent.
In certain embodiments, Applicants' laser glass composition comprises one or more glass network intermediators (XO). A glass network intermediator modifies the host glass network, thereby creating additional dopant sites. In certain embodiments, the one or more glass network intermediators bridge some of the bonds in the network thereby increasing the network's strength and chemical durability without raising the melting temperature appreciably. In certain embodiments, Applicants' germanosilicate glass host is modified using one or more XO materials selected from Al 2 O 3 , B 2 O 3 , La 2 O 3 , or combinations thereof, from 0.5 mole percent to 40 mole percent.
Table 1 recites Applicants' glass compositions. The glass compositions recited in Table 1 can be doped with Tm 3+ only, Tm 3+ /Ho 3+ co-doped, or Ho 3+ only.
TABLE 1
Glass compositions in mole percent
Glass No.
SiO 2
Al 2 O 3
GeO 2
Li 2 O
Na 2 O
CaO
BaO
S-G-2-s
55
2.5
4.25
3
3
16
16.25
S-G-3-s
45
2.5
10
5
5
16.25
16.25
S-G-17-s
55
4
4.5
0
0
18.25
18.25
S-G-18-s
50
4
9.5
0
0
18.25
18.25
S-G-19-s
44.5
4
15
0
0
18.25
18.25
S-G-C-54
18.5
6
41.5
7
7
10
10
S-G-C-60
35
6
25
7
7
10
10
S-G-C-1-s
35
6
25
7
7
10
10
S-G-C-2-s
35
6
25
7
7
2
18
S-G-C-3-s
35
6
25
7
7
2
18
S-G-30-s
30
6
30
0
0
17
17
In certain such embodiments, Applicants' germanosilicate glass has a Tm 3+ doping concentration of between about 2 weight percent to about 15 weight percent. In certain such embodiments, Applicants' germanosilicate glass has a Tm 3+ doping concentration of between about 4 weight percent to about 7 weight percent. In yet other embodiments, Applicants' germanosilicate glass has a Ho 3+ doping concentration of between about 0.1 weight percent to about 3 weight percent. In certain such embodiments, Applicants' germanosilicate glass has a Ho 3+ doping concentration of between about 0.4 weight percent to about 2 weight percent. In yet other embodiments, Applicants' germanosilicate glass co-doped with a Tm 3+ doping concentration of between about 2 weight percent to about 15 weight percent and a Ho 3+ doping concentration of between about 0.1 weight percent to about 3 weight percent. In certain such embodiments, Applicants' germanosilicate glass is co-doped with a Tm 3+ doping concentration of between about 4 weight percent to about 7 weight percent and a Ho 3+ doping concentration of between about 0.2 weight percent to about 2 weight percent.
Additionally, Applicant's germanosilicate glass exhibits excellent thermal properties as, during the fiber drawing process, the fiber preform is heated to the glass softening temperature, which is around 200° C. above the glass transition temperature. No crystallization occurs during fiber drawing process otherwise scattering loss will be introduced in the fiber.
To make Applicants' glass compositions, starting materials having a purity greater than about 99.99% are preferably utilized. The glass is melted in a platinum crucible in a resistance heated furnace. Typically, chemicals are loaded at 1300° C., and heated to 1450° C. after melting. The glass liquid is kept at around 1450° C. in liquid nitrogen protected environment in order to remove OH − groups from the glass. The glass is then cast into a preheated aluminum mold.
After the glass solidifies, it is moved into an annealing oven for annealing process to remove the cast induced stress. Glass samples can then be fabricated for characterization of thermal properties and measurement of the refractive index and absorption.
Applicants have fabricated germanosilicate glasses with doping concentrations of 2 weight percent, 3 weight percent, 4 weight percent, 5 weight percent, 6 weight percent, and 7 weight percent of Tm 2 O 3 . FIG. 1A illustrates absorption spectra 100 comprising spectrum 110 for a 3 weight percent Tm 2 O 3 doping, and spectrum 120 for a 6 weight percent Tm 2 O 3 doping.
Applicants have further fabricated germanosilicate glass with that is Ho 3+ -doped or Tm 3+ /Ho 3+ co-doped. FIG. 1B illustrates the absorption spectra 130 comprising spectrum 140 for a germanosilicate glass co-doped with 6 weight percent Tm 2 O 3 and 0.4 weight percent Ho 2 O 3 and spectrum 150 for a germanosilicate glass co-doped with 6 weight percent Tm 2 O 3 and 2 weight percent Ho 2 O 3 . FIG. 1C illustrates the absorption spectra 160 comprising spectrum 170 for a germanosilicate glass comprising 1 weight percent Ho 2 O 3 and spectrum 180 for a germanosilicate glass comprising 3 weight percent Ho 2 O 3 .
Applicants have also fabricated undoped cladding glasses. As those skilled in the art will appreciate, cladding glasses must comprise a similar thermal expansion coefficient with respect to the doped core glass to ensure low mechanical and thermal stress in the fiber, and a lower refractive index compared to the core glass to form waveguide. FIG. 2 illustrates thermal expansion curves of Tm 3+ -doped germanosilicate glass. As will be appreciated by those of ordinary skill in the art, as Applicants use the same or similar glass compositions for their Ho 3+ -doped and Tm 3+ /Ho 3+ -co-doped germanosilicate glass, the thermal properties of these glasses are very similar to that depicted in FIG. 2 .
Fiber preforms can be formed using doped core glass rod and undoped cladding glass tubes. Doped core glass rods are drilled from a bulk core glass using diamond core drill and the barrel of the rod is polished to a high surface quality. The undoped cladding glass tubes can be drilled from cladding glasses. Both inside and outside surfaces of the glass tubes are polished to a high surface quality. Tm 3+ -doped germanosilicate glass fibers are then pulled using a fiber drawing tower.
FIG. 4 shows a fiber preform 400 comprising cladding 410 and core 420 . In certain embodiments, the cladding diameter was about 229 microns, and the core diameter was about 41.5 microns.
FIG. 5 shows a fiber preform 500 comprising cladding 510 and off-center core 520 . In certain embodiments, the cladding diameter was about 216 microns, and the core diameter was about 18.5 microns.
FIG. 6 shows a fiber preform 600 comprising first cladding 610 , second cladding 620 , and core 630 . In certain embodiments, the first cladding diameter was about 245 microns, the second cladding diameter was about 210 microns, and the core diameter was about 21.5 microns.
FIG. 7 shows a fiber preform 700 comprising first cladding 710 , second cladding 720 , and off-center core 730 . In certain embodiments, the first cladding diameter was about 231 microns, the second cladding diameter was about 195.5 microns, and the core diameter was about 20.5 microns.
FIG. 8 illustrates apparatus 800 which can be used for fiber laser characterization. Fiber pigtailed multi-mode 790 nm diode lasers 805 and 810 are used as pump sources. The core of the pump laser delivery fiber is 125 micron. The delivery fiber of the pump laser is fusion spliced with a Tm-doped germanosilicate glass fiber 820 . Fiber Bragg grating 830 is used as the high reflectivity mirror for the fiber laser cavity. Fresnel reflection of approximately 5% from the Tm 3+ -doped germanosilicate glass fiber was used to form the fiber laser cavity.
FIG. 3 shows the fiber laser test results using apparatus 800 ( FIG. 8 ) and F-Tm-24 fiber with different fiber lengths. The cross section view of F-Tm-24 fiber was shown in FIG. 7 . Curve 310 was obtained using a 20 cm fiber length. Curve 320 was obtained using a 40 cm fiber length. Curve 330 was obtained using a 100 cm fiber length.
A slope efficiency of 40% was achieved in F-Tm-24 fiber with 100-cm fiber length. It should be noted that the slope efficiency depends heavily on the reflectivity of the output coupler. Here the reflectivity of the output coupler is fixed because apparatus 800 simply uses the Fresnel reflection of the output end of the fiber. The slope efficiency can be significantly improved by optimizing output coupler.
FIG. 9 illustrates the fiber laser performance using apparatus 800 ( FIG. 8 ) and a 1.2 m germanosilicate glass fiber co-doped with 5 weight percent Tm 2 O 3 and 0.4 weight percent Ho 2 O 3 .
While the preferred embodiments of the present invention have been illustrated in detail, it should be apparent that modifications and adaptations to those embodiments may occur to one skilled in the art without departing from the scope of the present invention as set forth in the following claims.
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A laser glass fiber with a core of the fiber comprising a germanosilicate glass host, one or more glass network modifiers, one or more glass network intermediators, and Thulium ions, Holmium ions, or a combination of Thulium ions and Holmium ions. The fiber emits laser light from 1.7 micron to 2.2 micron.
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BACKGROUND OF THE INVENTION
The present invention relates to a thermal printer having a thermal head and a platen for printing information on continuous paper which holds labels, tags or the like, and more particularly relates to a paper autoloading mechanism which prevents wastage of paper, at the start of the printing process.
DESCRIPTION OF BACKGROUND ART
In thermal printers of the type referred to above, the driving power for feeding the continuous paper is conventionally provided solely through rotation of the platen roller, which platen roller is in pressure contact with the thermal head. To set the position of the continuous paper with respect to the printing section of the printer, the leading end of the continuous paper which has been previously loaded in the paper supply section of the printer is grasped between the fingers, passed through a label pitch sensor located between the paper supply section and the printer section, and inserted into the printer section The printer section serves both to imprint information on and to feed (draw) the continuous paper.
After the continuous paper has been set manually in this manner, it is necessary to properly align the leading end of the first label or tag of the continuous paper with the printer section. To this end, when the printer is turned on, the platen roller is rotated to feed the paper until the label pitch sensor outputs a pitch detection signal which indicates that the leading end of the label or tag has been properly aligned.
Because of the relative positions of the printer section, the label pitch sensor, and the leading end of the labels or tags, the first one or two labels or tags on the continuous paper are invariably conveyed past the printer head and are thus wasted.
SUMMARY OF THE INVENTION
Accordingly, it is an object of the present invention to provide a continuous paper autoloading mechanism for a thermal printer capable of properly aligning continuous paper at the start of printing so that label wastage is avoided.
The foregoing and other objects of the present invention are realized by a mechanism which does not rely on the platen roller as the sole means of feeding the paper. Rather, a further paper feeding means is provided in the vicinity of the continuous paper supply section. This further paper feeding means is constructed to operate synchronously with the platen roller.
More specifically, the invention provides a continuous paper autoloading mechanism for a thermal printer comprising a continuous paper supply section, a paper feeding means, a pitch sensor for detecting the pitch of labels or tags of the continuous paper and for producing pitch signals, a paper guide and a printing means which includes paper feeding means. The foregoing elements are disposed in succession, in the direction of paper feed. The paper feeding operation of the paper feeding means and of the printing means are synchronized and controlled in response to the pitch signals to feed the leading edge of the continuous paper into proper alignment with the printing means.
The continuous paper used with the autoloading mechanism according to this invention is in the form of a continuous strip on which labels or tags are serially disposed. A segment of a label strip is shown in FIG. 2, by way of example. The continuous paper (label strip) 1 comprises a tape-like backing sheet 4 having labels 2 attached thereon at regular intervals. As shown in FIG. 1, the continuous paper 1 is wound on a supply reel disposed at a supply section 6. Alternatively, the continuous paper 1 can be in the form of a strip of continuous tags which are separated by perforations for being easily detached from one another, avoiding the need for a backing sheet.
The manual phase of the paper loading process consists of feeding the leading end of the continuous paper 1 between the rollers 11 and 12 of a feeding means and pressing an autofeed button (not shown).
Pressing the autofeed button starts a pulse motor 10 which rotates both the feed roller 11 of the feeding means and also the platen roller 14. The continuous paper 1 is thus advanced (autoloaded) and, simultaneously, the thermal head 15 is raised. In the raised position of the thermal head 15, little or no traction exists between the platen roller 14 and a carbon ribbon 7 that passes over it. Consequently, fresh carbon ribbon is not fed during the initial feeding and alignment of the continuous paper 1. This saves carbon ribbon.
When the continuous paper 1 is fed forwardly by the feed roller 11, its leading end is detected by a pitch sensor 18 located at an intermediate position of a paper guide 19 which forms a feed path for the continuous paper 1. The detection signal from the pitch sensor 18 is supplied to a microcomputer (not shown) in the memory of which is stored a value corresponding to the distance L between the pitch sensor 18 and the printing means. It is noted that when the paper arrives at the printing section, the platen roller 14 is used to press the paper against the thermal head 15. Upon receiving the detection signal, the microcomputer 10 outputs to the pulse motor 10 a value corresponding to the number of feed pulses needed to move the paper by the distance L. This starts the paper moving toward the printing section.
Next, the pitch sensor 18 detects the pitch of the labels of the continuous paper 1, that is the distance l between adjacent detection marks, holes or the like which enable the device to distinguish the labels from one another. Specifically, the microcomputer counts the number of feed pulses outputted to move the paper between the first and second detection marks. The result is stored as the label or tag pitch of the particular continuous paper 1. This enables the device to operate with differently sized labels or tags.
Upon determination of the label pitch, the number of feed pulses Pb corresponding to the detected label pitch is subtracted from the number of feed pulses Pa corresponding to the distance between the pitch sensor 18 and the printing means. The subtraction result is stored in the microcomputer memory. Thereby the number of feed pulses Pc needed to further feed the continuous paper 1 so as to cause the leading edge of the first label to be properly aligned with the printing means is obtained.
The microcomputer outputs the number of pulses Pc to the motor 10, thus completing the initial setting of the continuous paper 1. After the continuous paper 1 has been to be in correct alignment with the printing means in this manner, an electromagnet 17 is de-energized. This allows the thermal head 15 to return to its normal position and to clamp the continuous paper 1 between itself and the platen roller 14. This completes the autoloading operation.
Other features and advantages of the present invention will become apparent from the following description of the invention which refers to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS o FIG. 1 is a schematic view of a thermal printer having an autoloading mechanism according to the present invention.
FIG. 2 is a plan view of a section of an exemplar of a continuous label strip, usable with the autoloading mechanism according to this invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The invention is explained below with reference to FIG. 1 which shows the overall arrangement of the autoloading mechanism. FIG. 2 shows a continuous paper which holds sequentially arranged labels.
In the case of the continuous paper having the labels 2 shown in FIG. 2, the individual labels 2 are coated on their rear sides with an adhesive 3 by which they are detachably attached to the backing sheet 4. The distance l between successive spaces or marks 5 separating the labels 2 from each other is defined as the label pitch.
Referring to FIG. 1, the continuous paper 1 is wound on a supply reel or the like and loaded into a supply section 6. The continuous paper 1 is led from the supply section 6 through a continuous paper feeding means constituted of a feed roller 11 and a pressure roller 12 which resiliently bears against the feed roller 11. The paper then passes through a to-be-described pitch sensor 18 and is thereafter guided through a printing means constituted by a platen roller 14 and a thermal head 15.
A carbon ribbon 7 is paid out of a supply reel 8. It passes over guides (unnumbered) on its way to the printing means, where the ribbon 7 comes into intimate contact with the continuous paper 1. It then continues on to a take-up reel 9.
The paper feeding means 11,12 and the platen roller 14 of the printing means are synchronously driven by a pulse motor 10 via a timing belt 13.
The thermal head 15 is pivotally supported by a pin 16 about which it can swing upward by magnetic attraction provided through energization of an electromagnet 17 positioned immediately above it. In its raised position, the thermal head 15 is separated from the platen roller 14 that normally presses against it and which forms with it a label path.
The pitch sensor 18 is located between the feed roller 11 of the feeding means and the platen roller 14 of the printing means. Put another way, the feeding means for the continuous paper 1 is positioned between the pitch sensor 18 and the continuous paper supply section 6. To ensure reliable guiding of the continuous paper 1, a paper guide 19 extends from immediately upstream of the feeding means 11,12 to immediately upstream of the printing means 14,15.
More precisely, the pitch sensor 18 is positioned in the vicinity of the feeding means 11,12, at a distance L from the printing means, with L being greater than the aforesaid label pitch l.
The pitch sensor 18 depicted in FIG. 2 is a transmission type sensor consisting of a light emitting element and a light receiving element, the two elements facing one another across the path of the continuous paper 1. The output of the pitch sensor 18 (specifically, the light receiving element) has three levels: (1) a high level produced when no label is present in the light path, (2) a medium level produced when only the backing sheet 4 is present within the light path (this occurs when the leading end of the continuous paper, which precedes the first label, or a portion of the continuous paper between labels, is disposed between the sensor elements), and (3) a low level produced when a double layer consisting of the backing sheet 4 and the label 2 is within the light path. The device of the present invention is able to distinguish between these three states.
The operation of the autoloading mechanism is as follows.
First, the pressure roller 12 which normally presses against the feed roller 11 is raised and the leading end of the wound continuous paper 1 which is loaded in the supply section 6 is set between the two rollers. The pressure roller 12 is then allowed to resume its normal position at which it clamps the leading end, i.e. the header, of the continuous paper 1 between itself and the feed roller 11.
Next, an autofeed button (not shown) is pressed to start the pulse motor 10. The rotation of the pulse motor 10 is transmitted via the timing belt 13 to the feed roller 11. As a result, the continuous paper 1 is controllably autofed between the feed roller 11 and the pressure roller 12. Simultaneously, the electromagnet 17 is energized whereby the thermal head 15 is raised and the otherwise clamped carbon ribbon 7 between the thermal head 15 and the platen roller 14 is released. This prevents unnecessary and wasteful feeding of the carbon ribbon 7 during the loading operation.
Since the feed roller 11 of the feeding means and the platen roller 14 of the printing means are interlinked and both are driven by the pulse motor 10 through the timing belt 13, the system can be controlled with a microcomputer to feed the paper by the feeding means 11,12 and by the platen roller 15 at the same speed.
Rotation of the feed roller 11 causes the leading end of the continuous paper 1 to be fed out and to be guided by the paper guide 19 toward the print head 14. In time, the leading edge of the first label attached to the backing sheet 4 thereof is detected by the pitch sensor 18.
More precisely, the pitch sensor 18 produces at first the high level output as no continuous paper is detected. This output falls to the medium level when the backing sheet 4 header reaches the sensor 18, and finally falls to the low level when the leading edge of the first label reaches the sensor. Thus, the leading edge of the first label is detected when the output of the pitch sensor 18 changes from the medium to the low level.
The distance L from the pitch sensor 18 to the printing means 14,15, specifically the printing position at which the platen roller 14 presses onto the thermal head 15, is stored in the microcomputer in advance. Once the pitch sensor 18 detects the leading edge of the continuous paper 1, the microcomputer outputs to the pulse motor 10 just enough feed pulses to move the paper 1 by the distance L.
Next the pitch sensor 18 detects the distance l which is equivalent to the distance from the space 5 of the first label to the space 5 of the next label. This distance is the label pitch.
Since the labels are not present at the spaces 5 on the backing sheet 4, as the first space 5 and then the leading edge of the second label pass by the pitch sensor 18, the output of the pitch sensor 18 changes from the low to the medium level and then back to the low level. Thus, the leading edge of the second label can be detected from the falling signal level.
The microcomputer counts the number of feed pulses produced between the detection of the leading edges of the first and second labels and stores the count as the label pitch value of the continuous paper which is presently loaded in the thermal printer.
After the label pitch is detected, the number of feed pulses Pb corresponding to the detected label pitch is subtracted from the number of feed pulses Pa corresponding to the distance L between the pitch sensor 18 and the printing means 14,15. The subtraction result designated as the value Pc is immediately stored in the microcomputer memory. The value Pc represents the number of feed pulses pc required to further feed the continuous paper 1 so as to cause the leading edge of the first label to be exactly aligned with the printing means 14,15.
The microcomputer outputs the number of pulses Pc to the motor 10 and thus completes the initial setting of the continuous paper 1. After the continuous paper 1 has been advanced for proper alignment at the printing means in this manner, the electromagnet 17 is de-energized, causing the thermal head 15 to return to its normal position to clamp the continuous paper 1 between itself and the platen roller 14. This completes the autoloading operation.
It will be understood that while the thermal head 15 is in the raised position there is little or no friction between the carbon ribbon 7 and the platen roller 14 so that the carbon ribbon 7 is not fed forward, even though the platen roller 14 is rotated synchronously with the feed roller 11 during alignment of the first label with the printing means. This avoids wastage of the carbon ribbon.
The invention is not necessarily limited to only such arrangements in which the spaces 5 are used to detect the label pitch. Alternatively, the surface of the tape-like backing sheet can be provided with detection marks whose reflectance differs from that of the other surfaces of backing sheet. In this case a reflection type pitch sensor is used and the label pitch is sensed as the interval between changes in output caused either by transition from a detection mark to the backing sheet or vice versa. If detection marks are not located at the leading edges of the respective labels, the distance between each detection mark and the leading edge of the associated label is taken into consideration in controlling feeding of the labels 5.
It was stated above that the distance L between the platen roller 14 and the pitch sensor 18 is greater than the label pitch l, i.e. the label length or repetition distance. However the invention is not necessarily limited in this manner. Even if the distance L is shorter than the distance l, autofeeding is still possible if two conditions are met. The first of these is that the label pitch data be stored in the memory of the microcomputer in advance and the second that a distance l' (not shown) between each detection mark and the leading edge of the associated label be smaller than the distance L, i.e. (l' is smaller than L). In this case, the label pitch data stored in the microcomputer in advance corresponds to the number of feed pulses of the pulse motor 10 needed to advance the paper by the distance L-l'.
During an autofeed operation, the stored data is read out upon detection of the detection mark by the pitch sensor 18 and the paper feeding operation is continued by an amount corresponding to the read-out data, whereby the leading edge of the first label of the continuous paper 1 is fed into proper alignment with the printing means.
In the foregoing embodiment, in which the portions of the backing sheet of the continuous paper 1 located between the labels constitute the detection marks, the distance l is zero so that the label pitch data to be stored in advance in the microcomputer memory is the number of feed pulses corresponding to the distance L.
As explained above, in the present invention, the means for feeding the continuous paper is not constituted solely by the platen roller of the printing means but also by a separate feeding means provided in the vicinity of the continuous paper supply section 6. More specifically, the autoloading mechanism comprises a continuous paper supply section, a paper feeding means, a pitch sensor and a printing means, disposed in the order mentioned, in the direction of paper feed. The feeding operation of the paper feeding means is synchronized with that of the printing means 14,15. As a result, when a fresh reel of the continuous paper is loaded into the thermal printer employing this invention, the first label, tag or the like of the continuous paper can be automatically aligned with the printing means, whereby continuous paper is not wasted.
Further, since the paper guide 19 extends at least from the feeding means 11,12, past the pitch sensor 18, and to the printing means 14,15, the continuous paper 1 can be reliably fed and guided.
Although the present invention has been described in relation to particular embodiments thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred, therefore, that the present invention be limited not by the specific disclosure herein, but only by the appended claims.
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A continuous paper autoloading mechanism for a thermal printer comprises a continuous paper supply section, a paper feeder, a pitch sensor for detecting the pitch of labels or tags detachably attached to the continuous paper and for producing pitch signals, a paper guide and a printer section having a paper feeding capability, all disposed in succession in the direction of paper feed. The paper feeding functions provided by the paper feeder and the printer section are synchronized and controlled in response to the pitch signals for feeding the leading edge of a first label on the continuous paper into proper alignment with the printer head, in a manner which avoids wastage of labels and carbon ribbon during the autoloading process.
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BACKGROUND OF THE INVENTION
The ever enlarging gap between world food supply and world demand for high quality food products continues, and has in the recent past and will continue in the future to force shifts from animal to vegetable sources of protein for human nutrition. Soy-based milk analogs are known in the prior art and have been shown to have potential in improving world-wide nutrition, particularly in less well developed countries. In this country, soybeans have been grown primarily for their oil content, the meal residue being used as livestock feed; only 3 to 5 percent of the annual domestic soybean crop is used for direct human nutrition. The largest domestic market for direct human use has been for milk substitutes for infants allergic or hypersensitive to bovine milk. Soy products are also currently used in a variety of applications including protein fortification and enhancement of functional properties in baked products, texturized imitation food products, the extension of comminuted meat products, and the fortification of breakfast cereals and beverages.
FLAVOR PROBLEMS
Although the functional and nutritional benefits of soy products have been demonstrated in numerous human food applications, the utilization of soybeans in non-Oriental food consumption patterns has been limited due to the presence in those soy products of biologically active components of the soybean and enzymes which catalyze the oxidation of fatty acids having conjugated carbon-carbon double bonds. The latter enzyme causes rapid flavor deterioration when raw soy flour is slurried or when soybeans are ground in water. It is largely this flavor problem which has precluded the extensive use of soy products outside the Orient. Numerous methods have been devised to reduce this off-flavor development; however these methods also reduce yields of soymilk, dispersable endogenous protein content and the functional properties of the protein generally, and the nutritional qualities of the soymilk occasionally. These processes have the further disadvantage of requiring large amounts of installed energy-intensive capital and a great deal of technical expertise in operation, and generate large amounts of waste water having high biological or chemical oxygen demand.
The extent to which undesirable flavor components are inherent in the soybean itself and the extent to which such flavors are produced during processing has not yet been fully defined. It is generally accepted, however, that comminution of the intact soybean during processing does in fact generate significant off-flavors, particularly when previously nonheat-treated soy particles contact water.
It is now generally recognized that the typical raw soybean flavor which results upon maceration of the bean is decreased by either moist or dry heat application preceding maceration, and this because the enzyme lipoxygenase (linoleate oxygen oxidoreductase, EC 1.13.11.12) is heat sensitive. Primary oxidation products of both lipoxygenase-catalyzed reactions and autoxidation are thought to involve the formation of nine- and thirteen-hydroperoxide isomers of linoleic acid, in which the hydroperoxide oxygen derives from the gaseous phase. These hydroperoxides in turn undergo a variety of enzymatic and nonenzymatic reactions to produce volatile carbonyls and organic acids which have very low flavor thresholds. Once the off-flavor is produced it is not currently possible to eliminate it entirely or to mask it. It has been further reported that the off-flavor caused by lipoxygenase activity, which results when the cell tissue of soybean cotyledons is disrupted in the presence of even a small amount of moisture, develops almost instantaneously. It is generally assumed that this enzymatic activity is minimal at the usual moisture content of dry merchantable soybeans before grinding or comminution.
Soymilk has been prepared for hundreds of years in the Orient by a traditional water-extraction method which involves soaking the soybeans in water for several hours, draining, grinding with additional water, filtering to remove the insoluble residue and cooking the filtrate for about thirty minutes. This process continues to be practiced today although it produces a soymilk which has a flavor to which Occidentals have not become accustomed. All efforts to transplant this process to developing third world cultures have failed largely as a result of the unacceptable flavor of this liquid product. It is generally recognized that the traditional Oriental method allows extensive lipid oxidation by lipoxygenase; grinding the bean in water produces ideal conditions for lipoxygenase activity (hydration, increased surface area for water contact, fat dispersion, abundance of oxygen, and optimum pH and temperature for enzyme activity). The filtered water extract is heat treated to pasteurize the extract and to partially reduce the off-flavor produced; it is only in this latter step that lipoxygenase is inactivated, far too late to preclude off-flavor development. In addition, some soluble protein is insolubilized by the heat, forming a surface scum or a precipitate which must be removed before bottling.
Dry-heat roasting of the whole unbroken soybean has been used to inactivate lipoxygenase and trypsin inhibitor prior to processing soybeans into numerous derivative products.
It was found that while dry heat at 200° F. for thirty minutes greatly reduced enzyme activity, protein extractability yield is also greatly reduced, a nutty flavor distinguishable from that of lipid oxidation products develops, a chalky texture in the extract is produced and the color darkens, all of which are undesirable.
The traditional soaking of whole soybeans at ambient temperature prior to wet grinding presumably tenderizes the beans, facilitates comminution or grinding and enhances extraction of solids. Yet, despite the fact that soaking is nearly always used, there is no clear demonstrated advantage to this pretreatment. In fact, lipoxygenase activity has been shown to occur, although at a low level, during this period even though soybean seed coat remains intact; at a very minimum, the soaking process brings the soybean lipoxygenase to a potentially active state from which the enzyme becomes instantly active once the soybean seed coat is disrupted.
Blanching of whole soybeans prior to grinding very severely and permanently "sets" the protein bodies therein, and denatures protein and therefore prevents solubilization of the soy proteins, allowing a yield of soybean solids including lipid and protein in the aqueous extract only much lower than soymilks prepared by other methods when centrifuged at 1000 g.
REDUCED YIELD
Ordinarily, the application of heat to effect inactivation of lipoxygenase and of antinutritional factors such as trypsin inhibitors is common to all known processes for the preparation of aqueous soybean extracts, but, major soy proteins are also denatured and rendered insoluble by heating in prior processes. Generally, the yield of solids in soymilk extracts decreases as a function of the extent and severity of the heat treatment. As a benchmark, approximately 62 to 65 percent of the whole soybean is recovered in centrifuged or filtered soymilk made by the traditional Oriental process and most common particles today. (Compare with Table 1 which shows the yield of the conventional processes compared with the process of this invention.)
Since blanching prior to grinding drastically reduces the solids and protein recovery of conventionally processed soybeans, the art sought to overcome the deficiencies of prior processes and to also provide a stable aqueous dispersion of soybean protein and other solids. U.S. Pat. Nos. 3,901,978 and 4,041,187 allegedly teach a process for the preparation of a bland, stable aqueous dispersion of whole soybeans through soaking, blanching to inactivate the lipoxygenase enzyme, comminuting the blanched soybeans and forming therefrom a slurry in water, and homogenizing the slurry in multiple steps with concomitant heat treatment. According to the alleged teachings of these patents, even undehulled soybeans can be used whereby 99 percent of the soybean solids become dispersed in the uncentrifuged soymilk. The process taught in the reference patents is known to those skilled in the art as the Illinois Process.
A study undertaken to directly compare the Illinois Process, in which blanching or moist heating of the intact soybean is accomplished before soybean disruption, with other processes known in the art in which the soybean is heated only during or only after disruption, is reported in "Soy Milk; a Comparison of Processing Methods on Yields and Composition", Journal of Food Science, Volume 43, pages 349-353 (1978). That comparative study demonstrated that the Illinois Process, after centrifugation (a step not taught or utilized in either patent) of the final homogenate at 642×G provided a yield of soymilk, i.e., the weight of soymilk or supernate after centrifugation of the final homogenate of only 59.2 percent; the total yield of soymilk solids, i.e., the weight of solids in the soymilk (supernatant) divided by the total weight of solids in the cooked slurry was found to be only 48.8 percent. (Compare with Table 1 showing results of the process of this invention.)
An object of this invention is to provide a process which provides a remarkably stable soy beverage with improved yields.
An object of this invention is to provide a process which provides a remarkably stable soy beverage with improved yields and less chemical browning while achieving greater than 90% inactivation of trypsin inhibitor.
An object of this invention is to provide a process which provides a remarkably stable soy beverage with improved yields and less chemical browning while achieving greater than 90% inactivation of trypsin inhibitor and having a thiobarbituric acid value of less than 15 p.p.m. basis moisture-free solids.
An object of this invention is to provide a process which provides a remarkably stable soy beverage with improved yields and less chemical browning while achieving greater than 90% inactivation of trypsin inhibitor having a thiobarbituric acid value of less than 15 p.p.m. basis moisture-free solids which avoids denaturing of the protein or setting of protein bodies and provides prolonged storage life.
An object of this invention is to provide a process which eliminates the need for energy intensive capital and technical expertise in preparation of soy products.
Yet another object of this invention is to provide a stable organoleptically acceptable product.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The discovery which constitutes the present invention is that the infusion of live steam into an aqueous slurry of comminuted whole soybeans, preferably, practically, instantaneously and the containment of such steam-injected slurry for a time sufficient to inactivate at least nine-tenths of the trypsin inhibitor activity and of all lipoxygenase, results in a nutritionally and organoleptically superior soymilk and enhanced yields of a stable dispersion of endogenous soybean solids and protein. By whole soybeans, here and throughout the specification, is meant soybeans with the hull intact.
The soymilk of this invention is an aqueous preparation of the soybean which exhibits:
(1) minimal destruction of essential amino acids;
(2) maximal retention with enhanced nutrient value and thus increased yield of soybean solids protein;
(3) optimal inactivation of trypsin inhibitors and reduced chemical browning; and
(4) enhanced flavor and palatability along with prolonged storage life.
Any of the known varieties of soybeans can be used in the practice of this invention provided that they are of merchantable quality passing without objection in the trade. For the practice of this invention, it is preferable that the soybeans be cleaned by conventional air aspiration means and mechanically classified to remove detritus such as stalks, twigs and rocks.
Whole soybeans, with hulls intact, are ground or comminuted in a suitable fashion. Comminuted particle sizes are sufficient for this purpose when the particles of comminuted soybeans pass through a screen having an opening of up to 0.200 millimeters, more preferably the openings being up to 0.125 millimeters. The comminuted whole soybeans or soy flour is then combined with water. Water and comminuted soybeans may be placed in the receiving end of an auger feeder of sufficient size to allow discharge therefrom of a homogenous slurry of the comminuted soybean to the inlet end of a positive-displacement pump such as a Moyno pump.
The rate of volumetric displacement of the Moyno pump is regulated by a variable speed reducer. Upon discharge from the Moyno pump, the slurry is fed under pressure greater than that of the infusing steam into a high shear mixing device such as a hydroheater valve in which an internal combining tube of the hydroheater valve diverts the slurry to the periphery of the steam infusion nozzle in such manner that the slurry envelops in a concentric manner the steam flowing into the combining valve.
As the preferred embodiment the process of the invention, the steam infusion of the slurry is accomplished under conditions which provide high shear treatment of the slurry and nearly instantaneous heating of the slurry, providing extraordinary turbulence and shear so as to contact each comminuted soybean particle with superheated steam instantly upon admission to the containment vessel. The rate of heat transfer and absorption into each particle is increased, thereby preventing temperature stratification, and providing rapid and uniform heat treatment of each particle.
Preferably after the mixture of the infused steam and soybean slurry, the infused slurry is discharged directly into a holding device. The length of residence time of the steam-infused slurry within the holding device is a function of the volume of that tube. Upon passing through the back pressure control valve at the terminus of the holding tube, the superheated steam-infused soybean slurry is (1) flashed to a holding vessel maintained at or below ambient atmospheric pressure if the process is conducted batchwise; or (2) conducted to a heat exchanger if the process is conducted in a continuous manner.
While resident within the receiving holding vessel or cooling heat exchanger to which the infused soy slurry is discharged, the slurry is also rapidly cooled to less than about 140° F. and preferably to less than about 120° F.
Preferably, the soy slurry is cooled from its flash discharge temperature of 212° F. to less than 120° F. in about 120 seconds and preferably in less than about 90 seconds. This rapid cooling is necessary to prevent the browning caused by the further degredation of heat-labile amino acids and peptides and oligopeptides containing those amino acids. The temperature above which browning occurs shall be referred to as "the browning temperature". The cooling also functions to decrease the rate of formation of Maillard condensation products between heat-denatured proteins or peptides and various carbohydrates, thus avoiding undue browning discoloration of the soymilk indicative of loss of availability of the Maillard reaction condensed proteins, peptides or amino acids to human digestive and absorbative capabilities.
It is known in the art that the protein efficiency ratio of soymilks containing less than 10 percent of original trypsin inhibitor activity may be predicted using the Hunter L value which measures the lightness--darnkess of a color, higher values indicating lighter color and less browning, lower values indicating a darker color and more browning. Browning in soymilks is indicative of protein and amino acid destruction. The amino acids methionine, cysteine, lysine, serine and threonine are found in soymilk and are known to be susceptible to heat damage. Since these amino acids are known to be the first growth rate limiting amino acids, their destruction in any protein product greatly reduces the protein efficiency ratio of that product. The empirical relationship known to the art for determining the protein efficiency ratio (PER) of soymilks as a function of the Hunter L value, and thus as a funcion of the extent of browning, is given by the simple arithmetic equation:
PER=0.027H-0.04,
where H equals the Hunter L value.
This color measuring test has been found very useful in the evaluation of relative extents of amino acids destruction.
The hydroheater valve for effecting the steam infusion under conditions of extreme turbulence and shear can be any commercially available such valve, such as that made by Hydro-Thermal Corporation, Milwaukee, Wis. The materials of construction of all of the components of this rapid hydration hydrothermal steam infusion cooking system are such as to be compatible with the handling of lipid-containing foods, that is, no metals or alloys thereof which might leach copper or iron or other heavy metals capable of catalyzing the oxidation of fatty acids are permitted in any of the materials of construction of the entire system. Preferably, the entire system is constructed of stainless steel.
It is further generally agreed that the nutritional quality of heat-treated soybeans or aqueous preparations thereof is inversely proportional to the trypsin inhibitor content; that destruction of at least nine-tenths of native trypsin inhibitor activity is essential to the retention of optimal nutritional quality of the soy protein; that the nutritional quality of the protein increases with heat treatment until a point is reached where significant amino acid degradation occurs. It is also known that the extent to which trypsin inhibitors are inactivated by heat is a direct function of temperature, of duration of heat treatment, of particle size, of pH, and of moisture content. The proper heat treatment of soy flour results in improved nitrogen and amino acid absorption in rats, as measured by the protein efficiency ratio assay, in direct proportion to the extent of heat destruction of trypsin inhibitors. Trypsin inhibitor content is generally taken as a good measure of the adequacy of heat treatment, provided that heating is not continued beyond the time required for 90 percent destruction of trypsin inhibitor activity or the point where substantial destruction of heat-labile essential amino acids occurs. It is also known that the rate of inactivation of trypsin inhibitors increases with more alkaline pH values, and that the rate of inactivation follows zero order kinetics at pH 6.8 and first order kinetics at pH 9.9 when using conventional heat-treating or retorting techniques.
Any suitable means for determining trypsin inhibitor activity may be used. In one means, to determine trypsin inhibitor activity, approximately 4.0 g of soymilk is diluted to 100 ml with distilled water and centrifuged at 30,000 g for 30 minutes at 5° C. The supernatant is diluted from 1:1 to 1:4, depending upon trypsin inhibitor activity. Trypsin inhibitor activity is assayed by the procedure of Swartz et al. (1977) Journal of Biological Chemistry 252:8105.
In addition to providing a level of inactivation of trypsin inhibitors to well below the maximal level thought acceptable in the art, the process of the instant invention is remarkably and effective in inactivating soybean lipoxygenase, thereby providing a bland beverage.
It has been found in the practice of the process of this invention that the rate of increase in the concentration of fatty acid hydroperoxides and resultant oxidation products increases in comminuted soybean slurries very rapidly, nearly doubling in the sixty second period following soybean disruption or comminution.
Thus in other embodiments of this invention the formation of oxidation products may be minimized by:
(a) rapidly heating the slurry shortly after formation;
(b) forming the slurry in a vacuum;
(c) sparging the slurry soon after formation with nitrogen or any other inert non-toxic, non oxygen-containing gas;
(d) adjusting the pH to below 3 or greater than 9.5; and
(e) slurrying with hot water (slurry temperature 780° C).
The foregoing we shall refer to collectively as means for preventing the substantial oxidation of the slurry.
The exemplary material is provided below to enhance an understanding of this invention, but is not to be construed to limit in any way the scope of the inventions being defined in the appended claims.
EXAMPLE 1
This Example relates to comminuting whole soybeans having the hulls thereon for use in the process of this invention. Seed grade Columbus soybeans from the 1976 crop, 99 percent pure with 88 percent germination, and with protein, crude free fat and moisture contents respectively of 37.9 percent, 21.9 percent and 8.1 percent are used in these experimental evaluations. The whole soybeans are ground in a hammermill through a 0.125 millimeter opening screen, one part of the comminuted soybeans being slurried in four parts water. In varying the slurry water temperature, it is found that the use of water at 9° C. does not materially reduce the rate of lipid oxidation over the first five minutes of slurry time, but does reduce the concentration of 2-thiobarbituric acid reactive materials after 70 minutes of slurry time to about one-half the value found in the use of slurry water at 25° C. It is further found that the slurry water temperature has to be increased to about 70° C. before lipid oxidation is substantially reduced, and that at 80° C. the rate of lipid oxidation is nearly zero. Further, the temperature optimum for maximum rate of generation of 2-thiobarbituric acid reactive materials is found to be about 25° C., which is also the temperature optimum for lipoxygenase activity reported in the art.
The whole seed-grade Columbus soybeans are then slurried in comminuted form in tap water at a ratio of four parts water to one part soy flour. The slurry is formed and transferred to a modified Hydro-Thermal Corporation hydrothermal jet cooker with hydro-heating valve and a downstream holding tube, back-pressure controlled. The soy slurries are divided into four batches and processed at cook temperatures of 250° F., 270° F., 290° F. and 310° F. (121° C., 132° C., 143° C. and 154° C.,) under continuous operation and at times indicated in Table 2. Upon discharge from the hydrothermal jet cooker to ambient atmospheric pressure, the flashed product is cooled within 5 seconds to 110° F. or less in an ice bath. A control sample, using the standard Oriental process, is prepared by cooking identically comminuted soybeans in the conventional manner in a Groen kettle at 210° F. (99° C.) in which cooking time started upon contact of the soy flour with boiling water and in which approximately 30 seconds were required to re-establish the cooking temperature after addition of the comminuted soybeans. During cooking the control sample is continuously agitated and upon completion of cooking is cooled in an ice bath.
Upon cooling, all samples are adjusted to 10 percent solids after initial determination of hydrothermally cooked slurry solids, and aliquot portions of each of the samples were then centrifuged at 2,700 rpm under 1,050 g centrifugal force for five minutes. The soymilk supernate is decanted and residual material weighed. Yields of the fractions and their respective solids and protein contents, and in the case of the supernate, the residual trypsin inhibitor activity as a percent of the original activity, and the color as measured by the Hunter L value are determined. The results of the comparative evaluations are shown in Table 1. As can be seen from Table 1, longer cooking times permit lower temperature use while shorter cooking times require higher temperatures. Thus, cooking time and temperature are inversely related.
TABLE 1__________________________________________________________________________Yield and Quality of Soymilk Processed by Steam-InfusionCooking at pH 6.7Cooking Conditions Soymilk Time Fraction Solids Protein Residual ColorTemperature (sec) Yield (%) Yield (%) Yield (%) TI (%) (Hunter L)__________________________________________________________________________Control99° C. (210° F.) 5 75.3 63.8 76.9 70.0 77.1Control- 300 74.7 63.3 75.6 23.2 76.9Oriental 900 73.9 62.7 75.1 11.5 76.2Process 1800 73.7 62.9 75.0 9.6 75.2 2700 72.9 61.8 74.2 8.0 73.6 3600 72.1 61.2 73.2 7.6 73.0Invention121° C. (250° F.) 5 76.4 65.9 78.1 73.3 78.3Steam 19 ND ND ND 57.0 NDInfusion 55 ND ND ND 21.3 NDProcess 85 74.9 65.6 77.0 13.2 79.0 145 71.0 63.4 74.4 11.6 78.5 205 72.9 64.6 74.9 8.9 78.2 265 73.8 66.0 76.2 8.0 77.9132° C. (270° F.) 5 75.3 64.8 75.8 72.0 78.3Steam 58 72.6 64.1 75.0 13.0 80.0Infusion 88 69.9 63.4 72.0 9.4 79.4Process 148 74.9 69.9 76.2 7.0 78.0 208 81.7 76.7 82.4 6.5 77.0 268 87.2 83.3 87.2 6.0 76.0143° C. (290° F.) 5 74.0 63.6 75.5 71.8 78.2Steam 9 ND ND ND 53.0 79.3Infusion 30 69.4 61.2 69.0 14.8 79.1Process 60 84.3 79.8 85.1 8.6 78.1 90 89.0 84.7 89.3 7.7 76.7 150 86.1 85.2 82.7 6.5 74.2 210 85.3 78.7 82.0 5.6 73.0 270 84.2 76.8 80.0 4.4 71.5154° C. (310° F.) 5 76.0 65.8 77.7 71.1 79.0Steam 11 72.9 64.6 76.4 32.5 79.8Infusion 25 88.2 84.8 85.8 10.9 79.0Process 34 90.2 86.0 89.4 8.5 77.4 64 89.1 83.4 86.3 6.1 74.4 94 87.0 79.1 80.5 5.1 72.9 154 84.7 73.3 78.1 4.7 70.5 214 81.5 71.9 73.2 2.9 67.2__________________________________________________________________________ ND denotes not determined
EXAMPLE 2
The procedure of Example 1 is repeated except that samples cooked at a slurry pH of 9.5 were neutralized with 2 N HCl to pH 6.6 immediately after cooking and cooling. The results are reported in Table 2 below.
TABLE 2__________________________________________________________________________Yield and Quality of Soymilk Processed by Steam-InfusionCooking at pH 9.5Cooking Conditions Soymilk Time Fraction Solids Protein Residual ColorTemperature (sec) Yield (%) Yield (%) Yield (%) TI (%) (Hunter L)__________________________________________________________________________Control99° C. (210° F.) 5 78.5 66.5 79.1 45.6 76.2Control- 300 74.6 65.9 75.3 5.5 73.5Oriental 900 72.9 64.8 77.2 3.0 70.8Process 1800 74.2 67.6 73.9 1.8 67.1 2700 74.4 66.6 73.9 0.9 65.8 3600 73.7 63.7 73.9 Trace 63.6Invention121° C. (250° F.) 5 79.7 69.0 76.7 47.5 77.2Steam 25 74.3 64.8 74.9 12.8 77.2Infusion 40 74.8 65.8 75.7 9.0 77.2Process 85 72.0 63.0 71.9 7.2 76.1 145 73.2 65.4 73.0 5.9 74.9 205 76.7 70.1 76.7 4.1 73.6 265 81.3 76.2 82.0 3.8 71.1143° C. (290° F.) 5 78.9 68.7 79.8 27.2 77.3Steam 9 73.3 63.5 74.2 15.1 74.5Infusion 22 74.9 67.8 76.6 11.9 75.9Process 30 80.0 74.6 80.8 8.3 74.9 60 81.6 76.7 80.1 6.0 72.6 90 86.1 82.1 84.5 3.0 69.4 150 89.4 86.0 87.5 Trace 66.6 210 90.5 87.0 87.9 Trace 64.3__________________________________________________________________________
COMPARISON OF EXAMPLES 1 AND 2
It is noted that all inventive samples of Examples 1 and 2 exhibited an identical pattern in recovery of soybean solids in the milk fraction as a function of time and exposure to a given process temperature, namely, an initial decrease in yield at short times followed by a rapid increase to a maximal yield at intermediate times, and then a final decrease in yield at prolonged times. The pattern was consistent, with the point of maximal solids yield being directly dependent upon time and temperature. The process time for a maximum yield of solids is roughly halved for each 20° F. (11° C.) increase in temperature.
The great stability of the end product soymilk to be had in the practice of the instant process is believed to be brought about by the extensive shear and turbulence of the steam infusion process, short heat treatment at high temperature, the subsequent flashing to ambient pressure, and the rapid cooling to near ambient temperatures.
The samples processed at pH 9.5 provide patterns similar in solids yield recovery to those obtained in the samples processed at pH 6.7, with the exception that the time for arrival to a maximal solids and protein recovery is slightly higher at pH 6.7. It will readily be seen that generally, a processing at pH 9.5 reduced the cooking time for the production of equivalent yields of soymilk fraction, solids and protein.
It is clear from the results of Tables 1 and 2 that processing at pH 9.5 significantly increases the rate and the extent of chemical browning. The Hunter L value for all process times at 250° and 290° F. (121° and 143° C.) at pH 9.5 is significantly darker than comparable samples processed at pH 6.7. It is also clear that severe darkening occurred at 290° F. (143° C.) during long-time processing at pH 9.5. The results presented in Table 1 indicate much less chemical browning and consequently less amino acid destruction in high temperature, short time hydrothermal processing at neutral or near-neutral pH values than at alkaline values. It is further apparent from the results of Tables 1 and 2 that the kinetics of trypsin inhibitor inactivation are very much different than the kinetics of chemical browning.
Each of the samples evaluated and included in Tables 2 and 3 gave no indication of settling upon storage at 5° C. for a two-week period.
EXAMPLE 3
As in Example 1, whole seed-grade Columbus soybeans are ground in a hammermill through a 0.125 millimeter opening screen and are slurried in tap water in comminuted form at a ratio of four parts water to one part soy flour. The Hydro-Thermal hydroheating valve with downstream holding tube is used to process the soy slurry at a temperature of 310° F. (154° C.) for from 20 to 300 seconds at the inherent pH of the soybean, namely, pH 6.6 to 6.7. Again, upon discharge from the hydrothermal jet cooker, the flashed product is cooled to 110° F. or less in an ice bath. Upon cooling, the slurry is centrifuged at 2700 rpm under 1050 g centrifugal force for five minutes to remove the small portion of nonemulsified soybean solids, including the hulls. On a weight basis, the supernate is found to contain a minimum of 80 percent of the total soybean solids, in a soymilk representing recovery of at least 85 percent of the initial slurry, containing a minimum of 80 percent of the soy protein and between 7 and 9 percent of the original trypsin inhibitor activity. When spray-dried to less than about 7-8 percent moisture, the soymilk so prepared, provides a finely particulate, free-flowing, pale tan powder having exceptional organoleptic and functional properties. The soymilk may also be lyophilyzed to a comparable moisture content. This soy flour powder is bland and completely acceptable to health and natural-food advocates, has excellent water absorption and emulsifying properties, and is fully functional in baking, beverage, and confectionery applications for mammalian nutrition. The powdered product rehydrates readily and forms a stable aqueous emulsion or colloidal suspension at concentrations up to 50 percent by weight of water. Essentially all the lipid in the spray-dried product remains emulsified upon dissolution in water; no free fat separates from the aqueous layer.
With similar advantageous effect, as shown in Examples 2 and 3, the soy slurry of this example may be hydrothermally processed at temperatures higher or lower than 310° F. (154° C.), and for longer or shorter times than from 20 to 300 seconds, to yield a soymilk of identical quality although diminished in yield of total solids and protein when processed at temperatures lower than 310° F. in comparison to the slurry hydrothermally processed at 310° F. (154° C.) or higher for from 20 to 300 seconds.
EXAMPLE 4
The procedure of Example 3 is repeated but for the following modificatins:
(1) During the steps of soybean comminution and slurrying, means are used for preventing substantial oxidation of the slurry such as: the hammermill and the slurry forming auger are sparged with nitrogen; other inert, nontoxic and non oxygen-containing gas or gases may be used in place of nitrogen; the pH may be adjusted; a vacuum may be used; or the time between slurrying and heating minimized; or slurrying in hot water.
(2) Advantageously, the soymilk so prepared is found to contain lipid oxidation products as measured by the 2-thiobarbituric acid value with reference to total solids in the soymilk of less than 10 p.p.m. basis moisture-free solids; and
(3) Preventing substantial oxidation during slurrying advantageously allows recovery of a soymilk significantly decreased in concentration of fatty acid oxidation products.
EXAMPLE 5
The following soymilk is prepared as in Example 3, varying only temperature and time to provide a maximum of 7 to 8 percent residual trypsin inhibitor activity. The results are reported in Table 3.
TABLE 3__________________________________________________________________________Properties of Soymilk Processed by Hydrothermal Cookingat Various Temperatures to Inactivate 92-93% of theOriginal TI ActivityCooking Conditions Soymilk Time Fraction Solids Protein ColorpH Temperature (sec) Yield (%) Yield (%) Yield (%) (Hunter L Value)__________________________________________________________________________6.7 99° C. (210° F.) 3600 72.1 61.2 73.2 73.26.7 121° C. (250° F.) 280 74.1 66.4 76.6 77.66.7 132° C. (270° F.) 165 77.1 71.6 77.9 78.86.7 143° C. (290° F.) 100 88.0 84.0 88.0 76.66.7 154° C. (310° F.) 40 90.2 86.0 89.4 76.89.5 99° C. (210° F.) 150 76.6 66.2 77.2 74.99.5 121° C. (250° F.) 80 71.6 63.2 72.3 76.79.5 143° C. (290° F.) 40 80.5 75.3 80.6 74.0__________________________________________________________________________
EXAMPLE 6
The product of Example 3, containing approximately 90.5 percent water, 4.0 percent protein, the remainder being lipids, salts, and flatulence causing carbohydrates such as stachyose and raffinose, is subjected to ultrafiltration. Any commercially available ultrafiltration equipment with a molecular weight cutoff for retentate of approximately 40,000 daltons and provided with conventional ultrafiltration membranes made of mixed cellulose acetates manufactured by Abcon. (Suitable ultrafiltration membranes can also be made of polysulfones. Other manufacturers include Romicon, Osmonics, Dorr-Oliver or De Danske Sukkerfabrikker for the ultrafiltration membranes suitably employed for this process.) Upon recirculation of the ultrafiltration retentate, there is obtained a liquid product containing between 15 percent and 40 percent solids by weight, of which solids approximately half is protein and half is lipid. Advantageously, the ultrafiltration retentate may be spray dried to a powder of less than 5 percent total moisture to insure its keeping qualities. Upon maintenance of aseptic technique during the ultrafiltration process, the ultrafiltration retentate remains essentially sterile. Upon assay of the retentate for carbohydrates, it is found that the spray-dried product contains approximately one-half the carbohydrate endogenous to the whole soybean. Further reductions in the content of carbohydrate may be had through the conventional process known in the art as diafiltration, in which deionized water is mixed with the ultrafiltration retentate to further dissolve salts and carbohydrates and allow their permeation through the ultrafiltration membrane without limiting the flux rate there through by concentration polarization.
Although this invention is described 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 in the details of equipment and the parameters of the process may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.
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This invention relates to a process for making a soybean-based milk analog or soymilk and food products prepared therefrom.
The process involves the comminuting of whole soybeans having the hulls thereon, forming a slurry of the comminuted soybeans, simultaneously initiating the inactivation of trypsin inhibitor and lipoxygenase without fixing protein bodies or substantially denaturing the soybean protein, confining the heated slurry until the trypsin inhibitor activity is reduced to a desired value, cooling the slurry, and separating the hulls from the slurry to recover the desired product.
The resulting soymilk is an aqueous preparation of the soybean which exhibits minimal destruction of essential amino acids, enhanced nutritional value, maximal retention, and thus increased yield of soybean solids including lipid and protein, optimal inactivation of trypsin inhibitors, reduced chemical browning, and enhanced flavor and palatability along with prolonged storage life. The process is characterized by the instantaneous heat transfer through direct infusion of steam into the slurry.
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BACKGROUND OF THE INVENTION
[0001] This invention relates generally to hot tub or spa water treatment, and more particularly to time related control of such treatment.
[0002] Prior spa controls operate to circulate water, to heat water and to filter the water. A spa user manually activates the spa control or controls, turning it on for use and then turning it off.
[0003] Spas typically operate thermostatically, in the sense that the temperature is “set” and the spa operates to maintain that temperature. The spa user can “set” a filter cycle i.e. pre-programmed times or times when the spa will operate in order to filter the water. This allows the water to be circulated and run through the equipment's filtration apparatus, so that the water is filtered or “turned over”, meaning that all water is run through the filter. This helps to keep the water clean, prevents algae formation and circulates whatever sanitizer is being employed, to kill bacteria in the tub.
[0004] At the present time, all three of these functions operate independently of each other. The spa runs to maintain temperature, the spa owner can use the spa as he pleases, and the filter cycles turn on automatically at their pre-programmed or pre-set times. If the spa or tub should run for 1 hour a day to keep the water clean, the filter cycles are set for one hour per day in order to keep the water clean and clear. Dependent on the outside ambient temperature, the spa could satisfactorily operate for no time in the hot summer, or for 24 hours a day in the winter, to maintain temperature. The filter operates during such heating cycles, because the filter is connected to the main pump and heater.
[0005] There is need to provide for more efficient spa or tub operation, for example to reduce consumption of power needed to operate pumps, and without compromising efficient water filtering or sanitizing, or water heating.
SUMMARY OF THE INVENTION
[0006] It is a major object of the invention to provide apparatus and methods of operation which will meet the above, as well as other needs, as will appear. Basically, the invention concern a novel combination of steps of operation, employing timed control of spa water pumping, water filtering and/or water sanitizing.
[0007] The invention recognizes and concerns, for example, the following type situation:
[0008] If the spa only needs to run for 1 hour to keep the water clean and filtered, any operation over the 1 hour is not necessary to keep the water clean. If a tub runs for 2 hours to maintain the water set temperature, certain pre-set or pre-programmed filter cycles are not necessary, and are a waste of energy. The present invention enables a comparison of the total run time of the spa in between filter cycles with a selected parameter such as a desired filter cycle. If, in a 12 hour period between filter cycles, the tub does not run for a heat call, the filter cycle will run as it should. If the tub runs in order to maintain heat, the amount of time the tub has run is compared to the desired filter cycle, and a portion of the filter cycle is eliminated if sufficient filtering has occurred during heating. Accordingly, the tub operation will not waste energy to filter and clean the water, if the spa already has run for enough time to keep the water clean. These concepts are applicable to an enclosed body of water that is filtered and either heated, sanitized, run for therapy or display, with the filtration equipment connected to the pump being run. Examples are spas, hot tubs, pools, ponds, fountains, etc.
[0009] The program that determines the required filtration time of the tub varies with the size of the tub, usage, number of jets, size of filter, sanitizer being used, etc. and can be set or selected as by trial and error or calculated by comparison methods, knowing the desired objectives. Additionally, whether the filter cycle is completely turned off or calculated to the actual difference in time between the programmed filter time and the actual amount of time the tub ran (i.e. 60 minutes desired filter cycle—45 minutes heating=15 minutes left) is of lesser consequence. The concepts of comparing and contrasting these operations or actions in order to increase energy efficiency, reduce unnecessary wear on equipment, extend the life of the filter and seal, and numerous other benefits are of importance to the invention.
[0010] Accordingly, it is a major object of the invention to provide a method of controlling the operation of a spa water treating system, where such treating is selected from the group:
[0011] i) water filtration
[0012] ii) water sanitizing
[0013] iii) water heating
[0014] and that includes the steps
[0015] a) determining a desired water treating time interval as a function of timing of spa water prior treating interval, or usage,
[0016] b) and treating the spa water for that determined time interval.
[0017] Such treating may comprise water filtration, sanitizing, or heating, or combinations of these. Also, the timing of spa water prior treating interval is the time duration of such treating.
[0018] Yet another object is to provide a method of reducing pump water energy requirement, in a spa water circulation system, wherein the water pump is programmed to operate during timewise spaced cyclic intervals A 1 and A 2 to effect water filtration by a filter during such intervals, and wherein a water heater is operable for a time interval B to heat the water being circulated and filtered and in response to a drop in spa water temperature, the steps that include
[0019] a) determining said intervals A 1 , A 2 , and B 1 and
[0020] b) reducing or eliminating said cyclic interval A 2 as a function of duration of said time interval B.
[0021] These and other objects and advantages of the invention, as well as the details of an illustrative embodiment, will be more fully understood from the following specification and drawings, in which:
DRAWING DESCRIPTION
[0022] [0022]FIG. 1 is a schematic diagram showing a spa water control system;
[0023] [0023]FIG. 1 a is a control system diagram;
[0024] [0024]FIG. 2 is a circuit diagram;
[0025] [0025]FIG. 3 is a circuit diagram;
[0026] [0026]FIG. 4 is a time cycle example description; and
[0027] [0027]FIG. 5 is a timing sheet summary.
DETAILED DESCRIPTION
[0028] [0028]FIG. 1 schematically shows a hot tub or spa 10 containing water 11 to be treated. Treatment may typically include heating (as by a heater 11 ); filtering (as by filter 12 through which water flows); and sanitizing (as by use of dispenser 13 for sanitizing chemicals, as for example chlorine to be added to the water flowing to or from the spa 10 . A motor driven water pump 14 operates to withdraw water at 14 a from the spa, and return it to the spa at 14 b. A control unit 15 is operatively connected at 15 a, 15 b and 15 c to the pump water 14 c to turn the water ON and OFF and thereby control circulation, to the heater 11 to turn the heater ON and OFF in accordance with changes in sensed temperature of the water flowing to the pump; and to the chemical dispenser 13 to control a sanitizer (i.e. to dispense sanitizer at 13 a into the water flow, periodically). See also FIG. 1 a, showing a water temperature sensor 16 providing a heating control signal at 16 a to controller 15 .
[0029] Definition of water and controllable components are as follows:
[0030] A chemical sanitizer is defined as a chemical that has the ability to destroy or control the formation of contaminants. Typical of these are chlorine, bromine, biguanide, ozone, hydrogen peroxide and iodine.
[0031] A filter is defined as a device used to remove particulate from water by several means, including but not limited to pressure, vacuum, evaporation, or osmosis. Typical of these are fine mesh of varying materials and construction, sand particles, plastic particles, chemical particles, charcoal particles, reefing systems, coagulants, skimmers or vacuums.
[0032] A filtration system is defined as a device that incorporates a filter.
[0033] Additional water treating components that can be used are defined as follows:
[0034] An ozonator is a sanitizing system that creates ozone. Typical of these are an Ultra-Violet (UV) bulb, microchip or corona discharge (CD) chamber that produces varying amounts of ozone.
[0035] An ionizer is a sanitizing system that adds, either electrically or chemically, ions or halogens to the water via chemical or electrical reactions. Typical of these are electrolytic plates, copper and silver plates, stainless steel balls or plates and charcoal grids.
[0036] A predetermined or initially computed time for the cyclic operation of a filtration or sanitation system as at predetermined intervals is input at 17 into the control. The control then stores this information for reference and use. The system as at 17 a is initially activated when power is introduced to the system. A default setting, input by the manufacturer, will be the operational condition unless superceded by manual input or internal computation.
[0037] There are several means by which a filtration or sanitation system will operate during time periods when the spa, hot tub or pool is not being used. During such timewise spaced periods of operation, the filtration or sanitation system is operating, not as or for it's primary purpose, but as a secondary operation, concurrent to another programmed, automatic or required function. Typical of these are thermostatic controls, solar powered operation, circulation systems, automated vacuums, automatic leveling devices or spa covering devices.
[0038] Upon completion of a predetermined time period, the control compares the total run time of all systems that either directly or indirectly control or operate the filtration or sanitation system. The aforementioned predetermined time limit of cyclic filtering is initially input by the manufacturer, unless superceded by manual input or internal computation.
[0039] If the time limit of filtering (during pump operation as for example two fifteen minute periods of filtering over a 24 hour period), is met or exceeded, (as for example by additional filtering during operation of water heating equipment) the next set filtration or sanitation cycle is bypassed for that next time period, and a new comparison interval is initiated.
[0040] If the time limit is not met, the system will either operate for the entire pre-set time period, or for the remaining time difference between the two, or for a computed percentage of the original value. This is based on the application, usage, versatility of the control being employed or a number of other factors or constraints.
[0041] The control system can be utilized on newly designed or pre-existing apparatus. Various methods for sensing or measuring operation of the filtration or sanitation system can be employed. Likewise, the methods of connection to and means of controlling such systems can vary upon design and material construction and usage. However, none of the aforementioned connections, or sensing or operating constraints limit the scope of the described system or its accompanying design, description or applicable logical control.
EXAMPLE
[0042] Referring to FIG. 5, it shows timewise spaced cyclic intervals A 1 , A 2 , A 3 . . . A n , of water filtration, during which the spa water pump 14 is operating to circulate water in or through the hot tub or spa 10 . Such intervals are typically set. Typically, the circulating water passes in heating relation with the water heater 11 ; and, when the heater is ON, the flowing water is heated. The water is turned ON or OFF by control circuitry 15 which responds to the spa water temperature sensor 16 , as in thermostatic relation, to keep the water in the spa within acceptable temperature limits. A water filter 12 also operates to filter the water as it circulates (see path 14 a in FIG. 1).
[0043] The water pump is typically programmed to operate during timewise spaced or set cyclic intervals, shown for example at A 1 , A 2 . . . A n , which are equally spaced apart in time. The time spacing of such intervals is indicated by t 1 , which may for example be 12 hours. Thus, filtration occurs during equal time intervals A 1 , A 2 . . . A n , which may be between 5 and 30 minutes long, for example.
[0044] The circulating water heater 11 is or may for example, be operable during time intervals B to heat the water being circulated and filtered, and in response to a drop in water temperature, as referred to above, heating ending when sensed water temperature has increased to threshold level. B may occur timewise simultaneously, in whole or in part, with one or more of A 1 , A 2 . . . A n , and may have different time durations, dependent upon water heating requirements, as determined by weather, tub usage, etc.
[0045] The invention contemplates that if B occurs at a time t 2 , as indicated, it means that the pool water is being circulated at that time, which in turn means that water filtration is also occurring at that time. If the duration t 3 of B is greater than the duration t 4 of a subsequent set filtering cycle, say A 2 , then this means that the water has already been filtered, during B, by an amount in excess of filtration that would occur in A 2 , so that when the time arrives for A 2 to start, there is no need for A 2 . This then contemplates the steps:
[0046] a) determining said intervals A, A 2 and B, and
[0047] b) reducing or eliminating said cyclic interval A 2 , as a function of duration of said time interval B.
[0048] Therefore, the circuitry in software control 15 provides for A 1 , B, and controls the pump to eliminate A 2 (i.e. not operate to circulate water) if B is sufficiently long in duration (i.e. t 3 >t 4 ) or, if B is less than A 2 in duration, (i.e. t 3 <t 4 ) the duration of A 2 is controllably reduced (i.e. the pump water is deactivated) by or for the time duration of B, for example, i.e. the pump operates during the shortened interval (t 4 -t 3 ). Therefore, since the pump motor operation is reduced, electrical energy is saved.
[0049] The same mode of operation occurs for water treatment such as sanitizing, such treatment typically occurs cyclically, during filtration cycles as at A 1 , A 2 . . . A n . Therefore, need for sanitizing is reduced as A 2 is reduced, as a function of heater operation B.
[0050] [0050]FIG. 2 shows a comparator 40 for comparing t 3 and t 4 where t 3 is determined by needed water heating as determined by water temperature sensing at 16 .
[0051] [0051]FIG. 3 is an overall control circuit 40 a having input and output, as shown.
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A method of controlling the operation of a spa water treating system, where such treating is selected from the group:
iv) water filtration
v) water sanitizing
vi) water heating
and that includes the steps:
a) determining a desired water treating time interval as a function of timing of spa water prior treating interval, or usage,
b) and treating the spa water as a function of said determined time interval.
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STATEMENT OF PRIOR ART
The use of various paper compositions as substrates for the ingestion of a medicament is known in the art. Belgian Pat. No. 637,363 published Mar. 13, 1964 and Netherlands Pat. No.7,507,785 published Jan. 7, 1976 teach incorporation of the medicament into a paper web.
Higuchi et al U.S. Pat. No. 3,625,214 issued Dec. 7, 1971 describes pharmaceutical dosage forms prepared by depositing a matrix containing medicament on a substrate which might be of paper composition and then spirally rolling the coated substrate, e.g. in the manner of a jelly roll.
Finally, a series of U.S. Pats., e.g. No. 4,029,758 issued June 14, 1977 teach specific paper compositions useful in the preparation of a novel, solid unit dosage forms wherein finely divided medicament is loaded to the surface of one or more webs of paper or polymeric composition, and the loaded web(s) is fabricated into an orally ingestible, pharamaceutically and cosmetically acceptable shape and sealed so as to have no exposed medicament.
The latter mentioned patent claims a method of forming solid unit dosage forms wherein a stack of edible webs, e.g. 20 or more are fabricated into a unit dosage form by laminating only the edges. Upon ingestion, the laminated edges rupture thereby, allowing the stack of webs to separate and disperse. As this takes place, finely particulate medicament loaded to at least one of the sheets of web becomes exposed for absorption. In view of the number of sheets utilized in a laminate, the surface area available for absorption from such a unit dosage form is quite large in comparison to conventional dosage forms.
In accordance with the present invention, it has been found that a particular paper formulation, not heretofore suggested for the preparation of such unit dosage forms, possesses unexpectedly superior properties when utilized in the form of one or more sheets in an edge-sealed laminate unit dosage form.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 represents a graph plotting disintegration time of single sheets of the paper composition of the invention as a function of the density of the sheet.
FIG. 2 represents a graph plotting percent disintegration of single sheets of the paper composition of the invention in ten seconds as a function of the pressure applied to the sheet.
FIG. 3 represents a graph plotting the thickness change remaining in single sheets of the paper composition of the invention as a function of the pressure applied to the sheet.
DETAILED DESCRIPTION OF THE INVENTION
The paper webs utilized in the preparation of edge-sealed laminated unit dosage forms in accordance with the present invention along with a method for their preparation are taught in U.S. Pat. No. 3,826,711 issued July 30, 1974, the disclosure of which is incorporated herein by reference. The materials useful for the manufacture of the paper webs are disclosed in U.S. Pats. 3,589,364; 3,678,031 and 3,379,720, issued June 29, 1971; July 18, 1972 and Apr. 23, 1968 respectively. The disclosure of these patents are also incorporated herein by reference. The disclosed paper webs are coherent of at least partially water-soluble and water-swellable fibers of cellulose derivatives such as sodium carboxymethylcellulose, wet epichlorohydrin cross-linked sodium carboxymethylcellulose or sodium carboxymethylcellulose cross-linked by other means described in said patents. It is critical to the practice of the invention that the final sheets are not more than about 20% by weight soluble in water and preferably from about 2% by weight to about 10% by weight soluble in water. This limitation in water soluble fibers vs. water-swellable fibers is critical to the operation of the paper sheets in the dosage form as will be discussed hereinafter.
The paper webs contemplated herein are prepared with the materials and in accordance with the method described in the above mentioned patents. This method generally comprises forming a slurry of the fibers at a consistency of 0.5% to 3% by weight in an aqueous organic slurry media, e.g. water/methanol, containing from about 32% to 50% by weight water, forming a fibrous sheet from the dispersion on a filter media, washing the sheet in 2 to 5 stages of alcohol displacement washing gradually decreasing the water content of the sheet to about 0.02 to 0.5 part by weight water per part carboxymethylcellulose fiber and drying the resulting sheets. The webs must be uniform both in thickness and width. Generally, the webs should be from about 1 to about 25 mils. (about 0.025 mm. to about 0.64 mm.), preferably from about 3 to about 12 mils. (about 0.076 mm. to about 0.305 mm.) thick. The width of the web can be of any convenient size, for example 12 inches (30 cm.). The width of the web can be adjusted to the particular equipment being utilized. Likewise, the length of the web is not critical. Because the contemplated unit dosage forms are amenable to high speed manufacture webs are conveniently prepared in large quantity, e.g. 1500 feet or more, and stored, e.g. on cores or spools.
The improved edge-sealed laminates of the present invention are formed in accordance with the methods described in U.S. Pat. No. 4,029,758. For example, a suitable stack of webs can be continuously passed through a pair of heated reciprocating die plates which would form, seal and cut dosage forms simultaneously from the moving stack.
The stack of webs in the contemplated laminate may be predominantly sheets of edible polymeric material, sheets of edible paper or equal mixtures thereof. The edible polymeric webs are formed from a composition which, in general, comprises:
(a) One or more organic film formers, i.e. art-recognized, non-toxic film formers such as, for example, natural and chemically modified starches and dextrins, cellulose derivatives such as hydroxypropyl cellulose, sodium carboxymethylcellulose and the like, other polysaccharides such as pectin, acacia and the like, synthetics such as polyvinylpyrrolidone, polyvinylalcohol and the like. Preferred film formers are hydroxypropylcellulose and sodium carboxymethylcellulose;
(b) One or more plasticizers such as those recognized in the art of pharmaceutical compounding, for example, glycerin, the polysorbates, certain mixtures of mono- and di-glycerides of saturated fatty acids and the like;
(c) Modifiers, i.e. ingredients optional with certain formulations such as disintegrants, extenders, pigments and the like; and one or more fugitive solvents, e.g. water, lower alkanols such as methanol, ethanol and the like.
The polymeric formulations contain from about 5% by weight to about 95% by weight, preferably from about 40% by weight to about 90% by weight film former, from about 1% by weight to about 60% by weight, preferably from about 10% by weight to about 50% by weight plasticiser and from about 0% by weight to about 40% by weight of said modifiers, e.g. a disintegrant.
The edible paper webs other than those contemplated herein are formed from a composition which, in general, comprises:
(a) One or more fibrous materials such as, for example, cotton, linen cellulose, textured vegetable protein, preferably hardwood or softwood fibers or mixtures thereof;
(b) One or more non-fibrous modifiers, i.e. ingredients optional with certain formulations such as organic film formers such as enumerated above, disintegrants, extenders and the like; and
(c) A fugitive solvent, e.g. water, a lower alkanol such as methanol, ethanol, isopropanol and the like.
Preferred paper formulations comprise from about 70% by weight to about 99% by weight, preferably from about 90% by weight to about 96% by weight fibers, from about 1% by weight to about 30% by weight, preferably from about 4% by weight to about 10% by weight of a binder/disintegrant such as, for example, hydroxypropylcellulose, sodium carboxymethylcellulose, polyvinylpyrrolidone and the like, and from about 0% by weight to about 5% by weight, preferably from about 0% by weight to about 2% by weight of an edible surfactant such as, for example, polysorbate 80, dioctyl sodium sulfosuccinate and the like.
The paper webs are formed by conventional methods and on conventional apparatus such as, for example, the Fourdrinier paper making machines. The polymeric webs are also formed by methods conventional in the art, e.g. by casting on a suitable substrate such as Mylar, stainless steel, release paper or the like and then dried. The polymeric webs can also be formed by conventional extrusion techniques where the film forming component is amenable to such techniques, e.g. hydroxypropylcellulose.
The improved paper sheets utilized in edge-seal laminated pharmaceutical unit dosage forms in accordance with the present invention function unexpectedly to both seal the edges of the dosage form through the application of heat and pressure and to delaminate the unit dosage forms in the stomach. The capability of the paper sheets contemplated herein to function as delaminating sheets and therefore to disintegrate unit dosage forms incorporating them in the stomach can be controlled by altering the physical properties of the sheets. Therefore the capacity of sheets of identical chemical composition to function as delaminating agents can be altered by techniques such as calendering, basis weight control or other means known to those skilled in the paper arts. By the use of these techniques, one can control the density of the sheets.
As is evident from FIG. 1, one can control the rate of disintegration of the cross-linked carboxymethylcellulose sheets utilized in the present invention by adjusting the density of the sheet. It is further evident from FIG. 2 that the disintegration rate of the sheet is also related to the pressure in the calender stack. It can be seen from FIG. 3 that the thickness of the sheet can be calculated from the log normal effect of pressure, which is easily translatable into sheet density.
In addition, when conventional, untreated paper is incorporated into edge seal laminated pharmaceutical unit dosage forms as contemplated herein by a single application of heat and pressure utilizing heated dies that simultaneously form a plurality of unit dosage forms, many do not form cohesive units. Many of the unit dose forms that are formed exhibit splitting of the edges, e.g. in transit. Introduction of between about 2 and about 15 layers of the cross-linked carboxymethylcellulose paper as described herein into such unit dosage forms markedly increases the number of cohesive dosage units formed and reduces or eliminates the incidence of split edges in the finished unit dosage forms.
The above described dual functions are considered prepared by the method described in U.S. Pat. No. 3,826,711, i.e. a coherent fibrous sheet product formed from an aqueous alcoholic fibrous slurry comprised of at least partially water-soluble and water-swellable carboxymethylcellulose fibers, which has a communition quality of from about 0.1 to 30 and a water solubility not in excess of 20% is not known as being capable of precise swelling and disintegration as a function of the density of the sheet. Also, it is considered unexpected that, as applicants have found, stacks of this paper can be edge sealed by the application of heat and pressure. It has been found in accordance with the present invention that such sheets do in fact seal not only themselves but layers of conventional paper as well, and do in fact swell and disintegrate under the acid conditions of the stomach, and that the swelling and disintegrating properties are controllable post-manufacture by physical alteration of the sheet. It has further been found that, unexpectedly, edge-seal laminates such as described herein containing such sheets disrupt, thereby making the medicament contained therein available for absorption at a substantially enhanced rate over similar unit dosage forms which do not contain them. The capacity of the sheets to disrupt can be controlled by controlling pressure on the sheet thereby releasing the medicament from the unit dosage forms at any desired release rate pattern.
Two different mechanisms are contemplated herein for controlling the rate of release of medicament from edge seal laminated unit dosage forms are contemplated herein. The first of these is the use of the improved carboxymethylcellulose paper sheets described herein solely as a means to separate the medicament loaded sheets from the body of the edge-seal laminates. In this instance, the medicament will be loaded to sheets of conventional paper. In the stomach, the sheets of the improved paper composition function to delaminate the unit dosage forms. The second method utilizes the improved paper composition sheets both as delaminating and disintegrating means. In this instance, the medicament is loaded to the improved paper composition sheets, i.e. the sheet serves as a substrate for the medicament. The medicament loaded sheets are separated in the unit dosage form by sheets of non-loaded, conventional paper.
It has been found in accordance with the present invention that the laminates described herein, which generally contain from 5 to 60 sheets, preferably from 8 to 32 sheets, must contain the improved sheets as described herein in a ratio of at least one improved sheet for every medicament loaded sheet in the laminate, regardless of whether the remaining sheets are of a paper or polymeric composition. While it is in theory possible to have a laminate totally comprised of such improved sheets, in general a maximum content will be one improved sheet for every medicament loaded sheet therein. The improved sheets are randomly dispersed throughout the laminate, preferably evenly dispersed. The improved sheets may or may not have medicament loaded thereto as described in said U.S. Pat. No. 4,029,758. As a sealer layer, from about 1 to 20 sheets, preferably from about 3-8 sheets of the improved paper are utilized. The inclusion of these sheets in the unit dosage forms contemplated herein materially reduces delaminating and/or edge splitting in storage or transit.
By utilizing the improved sheets as described herein in an edge-sealed laminate unit dosage form, it is possible to achieve improvement both in rate an uniformity of release of medicament from such unit dosage forms in the stomach.
EXAMPLE 1
Edge-seal unit dosage forms were prepared by stacking twenty sheets of various paper composition webs as set forth below and subjecting them to heated reciprocating dies at a pressure of 13,000 lbs. p.s.i.g.
Coating layer
Cross-linked CMC layer
Medicament loaded layer
Cross-linked CMC layer
Sealing layers (12)
Cross-linked CMC layer
Medicament loaded layer
Cross-linked CMC layer
Coating layer
The coating layer comprised a conventional paper composition webs impregnated with 5% by weight sodium carboxymethylcellulose. The medicament loaded layers were conventional paper composition webs dry coated with chlorodiazepoxide. The sealing layers were conventional paper composition webs impregnated with hydroxypropylcellulose.
In the above lamination, the cross-linked CMC layer functioned to delaminate the medicament loaded layers from the sealing sheets in the stomach, i.e. artificial gastric fluid.
EXAMPLE 2
In accordance with the procedure described in Example 1, edge-seal unit dosage forms were prepared from the following stack of webs.
Coating layer
Medicament loaded cross-linked CMC layer
Non-disintegrating filler layer
Medicament loaded cross-linked CMC layer
Non-disintegrating filler layer
Sealing layers (10)
Non-disintegrating filler layer
Medicament loaded cross-linked CMC layer
Non-disintegrating filler layer
Medicament loaded cross-linked CMC layer
Coating layer
The medicament utilized was chlordiazepoxide. The non-disintegrating filler layer was a conventional web comprised of cellulose fibers. The cross-linked CMC layer functioned in this laminate as both as substrate and a delaminating layer.
EXAMPLE 3
In accordance with the procedure of Example 1, edge-seal unit dosage forms were prepared from the following stack of webs.
Coating layer
Cross-linked CMC layer
Medicament loaded layer
Cross-linked CMC layer
Non-disintegrating filler layer
Cross-linked CMC layers (10)
Non-disintegrating filler layer
Cross-linked CMC layer
Medicament loaded layer
Cross-linked CMC layer
Coating layer
In this lamination the ten internal cross-linked CMC layers functioned to seal the unit dosage form and the interspersed cross-linked CMC layers functioned to delaminate the unit dosage form.
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Use of an improved water-swellable carboxymethylcellulose paper in a unique pharmaceutical unit dosage form comprising a stack of edible webs laminated at the edges at least some of which are paper is described. The subject paper is a superior delaminating agent in said unit dosage forms.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional Patent Application No. 61/826,356, filed May 22, 2013, the content of which is herein incorporated by reference in its entirety.
STATEMENT OF GOVERNMENT SUPPORT
[0002] This invention was made with government support under grant numbers CA32551, 5P30-CA13330 and SIG 1S10RR019352 awarded by the National Institutes of Health. The government has certain rights in the invention.
FIELD OF THE INVENTION
[0003] The invention relates to assays for activators and inhibitors of actions of interleukin-34 (IL-34) that are independent of the colony stimulating factor-1 (CSF-1) receptor (CSF-1R) and play a role in development, homeostasis and disease.
BACKGROUND OF THE INVENTION
[0004] Throughout this application various publications are referred to in parentheses. Full citations for these references may be found at the end of the specification before the claims. The disclosures of these publications are hereby incorporated by reference in their entireties into the subject application to more fully describe the art to which the subject application pertains.
[0005] The CSF-1R kinase (1,2) plays a critical role in the regulation of macrophage and osteoclast production and function (3-6) as well as the development and regulation of other cell types (7-11). The existence of an additional CSF-1R ligand was proposed based on the greater severity of phenotype of homozygous null CSF-1R mice, compared to the phenotype of homozygous CSF-1-null mutant mice (12). A second ligand for the CSF-1R, interleukin-34 (IL-34), with no apparent sequence similarity to any other growth factor, was subsequently identified (13). While IL-34 and CSF-1 compete for binding to the CSF-1R and have similar CSF-1R-mediated effects, they exhibit significant tissue specific and developmental differences in their expression patterns (14). In addition, whereas CSF-1-deficient mice exhibit partial loss of microglia, CSF-1R-deficient mice have no microglia (15). This observation, together with the high expression of IL-34 in brain suggested an important role of IL-34 in microglial development. In agreement with this, IL-34-deficient (IL-34−/−) mice were shown to exhibit severe deficits in microglia (16,76). Despite the similarity of IL-34 and CSF-1 in their CSF-1R-mediated effects (14,17), IL34 mRNA is expressed at a significantly higher level than either Csf1 or Csf1r mRNA in several regions of the early postnatal and adult brain (14) and IL-34 protein is often expressed in regions where there is minimal expression of the CSF-1R or CSF-1-reporter proteins and IL-34 is significantly more active in suppressing neural progenitor cell proliferation and neuronal differentiation than CSF-1 (9).
[0006] Protein tyrosine phosphatase receptor type zeta (PTP-ζ) (18,19), a cell-surface receptor and a chondroitin sulfate (CS) proteoglycan (CSPG), is highly abundant in the brain (20), primarily expressed on neural progenitors and glial cells (21-23) and binds to and signals through the action of multiple ligands (24) including the growth factor, pleiotrophin (PTN) (25,26), the cell-surface protein, contactin (CNTN) (27) and the extracellular matrix (ECM) protein, tenascin-R (TN-R) (28). The binding of some of these ligands involves the CS glycosaminoglycan (GAG)-moiety of PTP-ζ (25,29). Ligand binding to PTP-ζ leads to increased tyrosine phosphorylation of down-stream targets, including β-catenin, β-adducin, Src-family kinases (SFK), focal adhesion kinase (FAK), paxillin and extracellular signal-regulated kinase-1/2 (Erk-1/2) (30-37). PTP-ζ is up-regulated in many human cancers, including glioblastomas, and regulates their proliferation and migration (38-40).
[0007] The present invention addresses the need for activators and inhibitors of actions of IL-34 that are independent of the CSF-1R receptor and play a role in development, homeostasis and disease.
SUMMARY OF THE INVENTION
[0008] The invention provides methods for determining whether or not an agent is a candidate agent for inhibiting interaction between interleukin-34 (IL-34) and protein tyrosine phosphatase receptor type zeta (PTP-ζ) comprising: contacting cells that express PTP-ζ on their surface and that do not express colony stimulating factor-1 receptor (CSF-1R) with IL-34 in the presence of the agent and in the absence of the agent, and measuring a cellular response induced by IL-34, wherein an agent that reduces a cellular response induced by IL-34 is a candidate agent for inhibiting interaction between IL-34 and PTP-ζ, and wherein an agent that does not reduce a cellular response induced by IL-34 is not a candidate agent for inhibiting interaction between IL-34 and PTP-ζ.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1A-1C . Interaction of IL-34 with PTP-ζ in solubilized membrane fractions of mouse brain. (A) N-octyl-β-D-glucoside (OG)-solubilized membrane fractions of mouse brain were incubated (4° C., 16 h) with either immobilized polyclonal rabbit anti-mIL-34 antibody beads that had been preincubated with mIL-34 (lanes 1 & 2), or with biotinylated mIL-34 (lanes 3, 4). The SDS eluates of the IL-34 immunoprecipitates or biotinylated IL-34 complexes (recovered with neutravidin beads) were analyzed by SDS-PAGE with silver staining. The IL-34-associated proteins identified with 99% certainty by mass spectrometry were PTP-ζ and TN-R ( FIG. 7 ). Western blots (WB) indicate the PTP-ζ (L, long isoform, P, phosphacan/soluble isoform and the ˜225-kDa short isoform) and TN-R staining bands. Multimeric (52) (slower migrating bands, ˜400 kDa) and alternatively spliced (faster migrating bands, 160/180 kDa) variants of TN-R were co-immunoprecipitated, or pulled down. (B) Scheme depicting various PTP-ζ isoforms. Upper panel, the long isoform (active) containing a carbonic anhydrase domain (CA) and a fibronectin type III repeat (F), a transmembrane domain (TM), protein tyrosine phosphatase domains (PTP1 and PTP2) and three glycosaminoglycan (GAG) addition sites. Middle, phosphacan or the secreted isoform lacking the (TM) and PTP domains. Lower, the short isoform (active) missing 860 amino acids of the long isoform. 3F8 and C-209 antibodies recognize the extracellular and intracellular regions of PTP-ζ, respectively and the 473-HD antibody all three isoforms. 3F8 is directed against rat phosphacan and is not as effective in detecting mouse PTP-ζ. C-209 antibody recognizes the short isoform from the mouse brain membrane lysates infrequently. (C) Co-immunoprecipitation of PTP-ζ with IL-34. The OG-solubilized mouse brain membrane fraction was incubated with mIL-34 (4° C., 16 h), immunoprecipitated with immobilized anti-PTP4 (3F8), or isotype control (mIgG1) antibodies and the immunoprecipitates analyzed by gradient SDS-PAGE and western blotting. L, long isoform; P, phosphacan and S, short isoform.
[0010] FIG. 2A-2C . IL-34 binds cell-surface PTP-ζ in U251 human glioblastoma cells. (A) Interaction of IL-34 with PTP-ζ in OG-solubilized U251 cell membrane fractions. Membranes lysates were incubated with biotinylated hIL-34 (4° C., 16 h), the complexes captured with neutravidin beads (4° C., 6 h), eluted with SDS and analyzed by SDS-PAGE and silver staining, or by western blotting (WB) with antibodies to PTP-ζ. Arrowhead, non-specific band; asterisk, PTP-ζ proteolytic product (51); L, long isoform; NG, non-glycosaminoglycan form; S, short isoform. (B) Reduced PTP-ζ expression in PTP-ζ KD U251 clones. Left panel; PTP-ζ and control (EF1α) western blots of OG-solubilized whole cell lysate from cells expressing scrambled, or PTP-ζ (KD1 and KD2) shRNAs. Right panel, quantitation of the combined intensities of the three bands (L, NG, S) from two independent experiments (average±range). (C) Flow cytometric analysis of hIL-34 binding to PTP-ζ KD U251 lines. Serum-starved control (scrambled) and KD (1 & 2) cells were either untreated, incubated with 5 μg/ml biotinylated hIL-34, then subsequently incubated with streptavidin-conjugated APC-Cy7 prior to flow cytometric analysis, gating on viable cells. G.M., geometric means of signal intensities of duplicate experiments (average±range).
[0011] FIG. 3A-3B . IL-34 inhibits growth and clonogenicity of U251 glioblastoma cells in a PTP-ζ-dependent manner (A) Cell proliferation assay. Control (left panel) or PTP-ζ KD (right panel) cells were incubated with the indicated factors for the indicated times and the viable cell numbers assessed by trypan blue exclusion staining (B) Clonogenic assay. Left panel, micrographs of colony forming assays of U251 cells incubated with vehicle or IL-34. Right panel, histograms showing average colony counts from triplicate experiments. (A) and (B), Means±SD; n=3; *, significantly different from cells incubated with vehicle alone, p<0.05.
[0012] FIG. 4A-4D . IL-34 inhibits PTP-ζ-dependent U251 motility. (A) Inhibition of U251 monolayer wound healing by IL-34. Left panel, numbers above the horizontal lines indicate the fraction of the initial wound width at the time of scratching. Scale bar, 100 μM. Right panel, quantitation (means±SD; n=3). (B) Quantitation of wound healing by control and PTP-ζ KD U251 cells at 9 h, in the presence of PTN or IL-34 (means±SD; n=3). (C) Inhibition of haptotactic migration by IL-34. Migration is expressed as a percent of cells migrated in the BSA control (means±SD; n=3, ≧15 fields per condition). (D) Inhibition of random migration by IL-34. Migration is expressed as a percent of cells migrated in no GF (vehicle) control (means±SD; n=3, ≧10 fields per condition). *, p<0.05 and **, p<0.01.
[0013] FIG. 5A-5C . IL-34 binding to PTP-ζ enhances tyrosine phosphorylation of FAK and Paxillin, in U251 cells. (A) Kinetics of tyrosine phosphorylation in response to IL-34. SDS-PAGE and western blot analysis of NP-40 lysates from U251 cells treated with IL-34 or PTN harvested at the indicated times and stained as shown. FAK, focal adhesion kinase; Pax, paxillin. (B) Immunoprecipitates of FAK (left panel) and paxillin (right panel) from NP-40 lysates of serum-starved U251 cells incubated with hPTN or hIL-34 (0.1 nM) western blotted with antibodies to phosphotyrosine (pY), FAK or Pax. (C) Abrogation of the IL-34 and PTN-induced phosphorylation of FAK and paxillin in U251 cells expressing PTP-ζ shRNA. Normalized to the total FAK and Pax expression and expressed as fold stimulation of levels in control (vehicle-treated) cells (dotted line).
[0014] FIG. 6A-6C . IL-34 binds to PTP-ζ in a CS-dependent manner. (A) Effect of Chondroitinase ABC on specific PTP-ζ isoforms. Anti-PTP-ζ western blot of U251 membrane lysates incubated with and without chondroitinase ABC (0.3 U/ml, 37° C., 1 h). L, long isoform; NG, non-glycosaminoglycan isoform; S, short isoform. (B) CS is required for IL-34 binding to PTP-ζ. Serum-starved U251 cells were either incubated with, or without ChABC (4.2 Um′) and subsequently with 2 μg/ml biotinylated hIL-34, prior to further incubation with streptavidin-conjugated APC-Cy7 and flow cytometric analysis, gating on viable cells. The vertical line defines the level of non-specific binding of biotinylated IL-34. (C) Competition with CS and the failure to compete with CSF-1 and PTN. 2×10 5 serum-starved U251 cells were pre-incubated with a 16 molar excess of IL-34 in the presence of increasing concentrations of CS, or with a 16 molar excess of CSF-1 or PTN, prior to washing and binding of biotinylated-IL-34 (2 μg/ml). Geometric means (G.M.) of signal intensities of duplicate experiments (average±range) were used to calculate percentage inhibition. *, p<0.05.
[0015] FIG. 7A-7B . LC-MS/MS peptide hits for TN-R and PTP-ζ. (A) TN-R protein sequence from mouse (SEQ ID NO:10). (B) PTP-β/ζ protein sequence from mouse (SEQ ID NO:11). The carbonic anhydrase homology domain (CA), the fibronectin type III repeat (F) and the two phosphatase domains (PTP1 and PTP2), are boxed. The consensus glycosaminoglycan (GAG)-addition sites are underlined and the transmembrane domain is italicized. The several N-linked glycosylation sites are not indicated. The peptide stretch missing in the short isoform is bolded.
[0016] FIG. 8A-8C . U251 cells lack the CSF-1R. (A) Failure of hIL-34 to bind to CSF-1R on U251 cells. N-octyl-β-D-glucoside (OG)-solubilized membrane fractions of BAC1.2F5 (lanes 1 & 2) and U251 (lanes 3 & 4) cells were incubated overnight at 4° C. with biotinylated mIL-34 (lanes 1 & 2) or biotinylated hIL-34 (lanes 3 & 4). The biotinylated IL-34 complexes were recovered by incubation with neutravidin and SDS eluates containing the complexes analyzed by SDS-PAGE and western blotting (WB) with an antibody that equivalently recognizes both mCSF-1R and hCSF-1R. (B) Absence of the CSF-1R in U251 cells. N-octyl-β-D-glucoside (OG)-solubilized membrane fractions of U251 human glioblastoma (lane 1) and NIH-3T3-hCSF-1R (lanes 2-4) cells were incubated overnight at 4° C. with anti-hCSF-1R antibody (lanes 1, 2) or biotinylated hIL-34 (lanes 3, 4). The biotinylated IL-34 complexes were recovered by incubation with neutravidin and SDS eluates of IL-34 pull-down and CSF-1R immunoprecipitates analyzed by SDS-PAGE and western blotting (WB) with antibodies to hCSF-1R. (C) Further verification of the lack of CSF-1R expression on U251 cells. Flow cytometric analyses of 2×10 5 viable 3T3-hCSF-1R and U251 cells were incubated with 5 μg/ml of rat monoclonal anti-hCSF-1R antibody, or rat IgG1 (isotype control) for 30 min at 4° C., washed with PBS and further incubated with 5 μg/ml of anti-rat IgG1-conjugated FITC for 30 min at 4° C.
DETAILED DESCRIPTION OF THE INVENTION
[0017] The invention provides a method for determining whether or not an agent is a candidate agent for inhibiting interaction between interleukin-34 (IL-34) and protein tyrosine phosphatase receptor type zeta (PTP-ζ) comprising:
[0018] contacting cells that express PTP-ζ on their surface and that do not express colony stimulating factor-1 receptor (CSF-1R) with IL-34 in the presence of the agent and in the absence of the agent, and
[0019] measuring a cellular response induced by IL-34,
[0020] wherein an agent that reduces a cellular response induced by IL-34 is a candidate agent for inhibiting interaction between IL-34 and PTP-ζ, and
[0021] wherein an agent that does not reduce a cellular response induced by IL-34 is not a candidate agent for inhibiting interaction between IL-34 and PTP-ζ.
[0022] The terms PTP-ζ. and PTP-β/ζ are used interchangeably in this application.
[0023] The cells can be, for example, glioblastoma cells, such as, e.g., U251 human glioblastoma cells.
[0024] The cells can have been transfected with nucleic acid encoding human PTP-ζ. Human PTP-ζ has the amino acid sequence (ACCESSION P23471, VERSION P23471.4 GI:229485537, SEQ ID NO:12):
[0000]
1
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61
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181
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241
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301
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361
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421
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481
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541
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601
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661
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721
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781
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841
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901
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961
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1021
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1081
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1141
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1201
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1261
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1321
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1381
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1441
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1501
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1561
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1621
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1681
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1741
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1801
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1861
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1921
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1981
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2041
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2101
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2161
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2221
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2281
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[0025] Cellular response induced by IL-34 can include any of the following. IL-34 can inhibit, for example, one or more of cell proliferation, clonogenicity and/or motility. IL-34 can induce tyrosine phosphorylation of a protein, such as, for example, focal adhesion kinase (FAK) and/or paxillin. IL-34 can also, for example, stimulate differentiation of neural progenitor cells.
[0026] The agent can be, for example, an antibody, a monoclonal antibody, a polyclonal antibody, an antibody fragment, a F(ab′) 2 fragment, a Fab′ fragment, a peptide, a peptide nucleic acid, or small chemical compound (e.g., have a molecular weight of 5,000 daltons or less).
[0027] The agent can bind to a chondroitin sulfate glycosaminoglycan (GAG) moiety on PTP-ζ or to a GAG mimic.
[0028] The agent can be useful, for example, for treatment of a disease or disorder or a defect in neural or microglial development or a defect in homeostasis. The disease or disorder can be, for example, cancer, inflammation, a central nervous system disease, brain injury, neuro-degeneration, a memory deficit, glioblastoma, multiple sclerosis, schizophrenia, or autoimmune disease.
[0029] This invention will be better understood from the Experimental Details that follow. However, one skilled in the art will readily appreciate that the specific methods and results discussed are merely illustrative of the invention as described more fully in the claims that follow thereafter.
EXPERIMENTAL DETAILS
Introduction
[0030] An unbiased proteomic approach identified PTP-ζ as an IL-34-interacting membrane protein in mouse brain. Using shRNA-mediated suppression of PTP-ζ expression in a CSF-1R-less U251 human glioblastoma cell line, IL-34 was demonstrated to bind specifically to cell-surface PTP-ζ to initiate downstream signaling that leads to the inhibition of cell proliferation, clonogenicity and motility. IL-34-binding to PTP-ζ is dependent on the presence of the CS GAG moiety on PTP-ζ. The demonstration of the existence of a novel IL-34 receptor increases the scope of biological effects of IL-34 in development, homeostasis and disease.
Materials and Methods
[0031] Reagents—
[0032] Purified mouse IL-34 (mIL-34), human IL-34 (hIL-34) and purified polyclonal rabbit anti-mIL-34 antibodies were from FivePrime Therapeutics, Inc., CA, USA) and human PTN (hPTN) was from R&D (Minneapolis, Minn.). Growth factors were suspended in phosphate buffered saline (PBS) as vehicle mIL-34 and hIL-34 were biotinylated using a 10 molar excess of EZ-Link Sulfo-NHS-LC-LC-Biotin (Thermo Scientific, MA, USA) (15′, 20° C.) following manufacturer's instructions. The rabbit anti-C-terminal CSF-1R peptide antibody (C-15) to the mouse CSF-1R (mCSF-1R) and human CSF-1R (hCSF-1R), used for western blotting and immunoprecipitation, has been previously reported (41). Other antibodies used for western blotting were directed against phosphotyrosine (pY-100) and β-catenin (Cell Signaling), pY118paxillin and pY397FAK (Life Technologies, NY, USA); hCSF1R (2-4A5), β-adducin, FAK and TN-R (Santa Cruz Biotechnology Inc., CA, USA); paxillin and PTP-ζ (C-209) (BD Biosciences), PTP-ζ (3F8) (DSHB, the University of Iowa); PTP-ζ (473-HD) (Santa Cruz Biotechnology Inc., CA, USA)(42); EF1α (43). Bovine serum albumin (BSA), was from Gemini (CA, USA), Puromycin dihydrochloride, trypan blue, crystal violet, DAPI, shark cartilage CS salts, Proteus vulgaris chondoitinase ABC (chABC) and phalloidin were from SIGMA (MO, USA). Polybrene was from Santa Cruz Biotechnology, Inc. (CA, USA). Neutravidin-Ultralink beads were from Thermo Scientific (MA, USA). Streptavidin-conjugated APC-Cy7 was from Biolegend (CA, USA). LIVE/DEAD® Fixable dead cell stain kits were from Molecular Probes (NY, USA). HTS FluoroBlok™ inserts and 24-well and 6-well tissue culture dishes were from BD Biosciences, Franklin Lakes, N.J. Accutase was from Stem Cell Technologies (Vancouver, BC, Canada). Human PTP-ζ and CSF-1R extracellular domains (ECD) fused immunoglobulin Fc domains (hPTP-ζ-ECD-Fc and hCSF-1R-ECD-Fc) were prepared as described previously for the hCSF-1R-ECD-Fc (13). Human recombinant CSF-1 (hCSF-1) was a gift from Chiron Corp. (Emeryville, Calif., USA). EDC/NHS, HBSP and HBSP+ buffers were from GE Healthcare Biosciences, Pittsburgh, Pa., USA.
[0033] Sample Preparation for LC-MS/MS-Identification of the Receptor—
[0034] Sub-cellular fractionation was carried out to isolate the membrane fraction from a pool of 2 postnatal day 7 and 2 postnatal day 60 mouse brains. Briefly, mouse brain tissue was homogenized in homogenization buffer (65 mM Tris, 150 mM sodium chloride, 1 mM EDTA, 10 μg/ml aprotinin, 10 μg/ml leupeptin and 1 mM benzamidine, pH 7.4) and the homogenate centrifuged (1000×g, 3 min, 4° C.). The supernatant was further centrifuged (100,000×g, 30 min, 4° C.) and the pellet dissolved in 2% N-octyl-β-D-glucoside (OG), prior to centrifugation (100,000×g, 30 min, 4° C.). The supernatant, containing 26 mg of the OG-solubilized membrane lysate was first pre-cleared by incubation with 60 μg of anti-CSF-1R peptide antibody (C-15) (4° C., 16 h) and then incubated with 24 μg of mIL-34 non-covalently bound to 40 μg of immobilized polyclonal rabbit anti-mIL-34 antibody (4° C., 16 h) mIL-34-anti-mIL-34 antibody complex was serially washed using 0.1 M glycine-HCl, pH 2.2 and 8 M urea and subsequently eluted with 1% SDS. The glycine-HCl and urea washes did not result in dissociation of proteins from mIL-34-anti-mIL-34 antibody complex, as determined by SDS-PAGE and LC-MS/MS. The denatured, reduced and alkylated SDS eluate was further concentrated by ultracentrifugation using 100 kDa cut-off filters and subjected to SDS removal, concentration, trypsinization and detergent extraction with ethyl acetate, as described elsewhere (44,45) followed by LC-MS/MS.
[0035] Nanoelectrospray LC-MS/MS Analyses and Protein Identification—
[0036] Tryptic digests were loaded and separated using the UltiMate, FAMOS, Switchos nano-HPLC system (LC Packings, Dionex; Sunnyvale, Calif.), connected on-line to a LTQ Linear Ion Trap mass spectrometer (Thermo Fisher Scientific, Waltham, Mass.) and equipped with a nanospray source. The mobile phases consisted of 5% acetonitrile/water, 0.1% formic acid (A) and 80% acetonitrile/water, 0.1% formic acid (B). After injection (15 μl of sample) and loading onto a C18 trap column, 0.3 mm I.D.×5 mm, the tryptic peptides were separated on a C18 analytical HPLC column (75 μm I.D.×15 cm; Pepmap, 3 μm, 100 Å; LC Packings, Dionex; Sunnyvale, Calif.). The flow rate for loading and desalting was 15 μl/min for 30 minutes while the analytical separation was performed at 250 ηl/min. The gradient used was: 2% to 55% B in 65 min; held at 55% B for 10 minutes; increase to 95% B in 5 min and then held at 95% B for 5 minutes. The HPLC eluent was electrosprayed into the LTQ using the nanospray source. After an initial MS-survey scan, m/z 300-1800, MS/MS scans were obtained from three most intense ions using a normalized collision-energy of 35%. DTA files were generated from the raw data files, merged and searched against all species of the NCBInr database (Jul. 2, 2010) using Mascot (version 2.3). The search parameters were: fixed modification—carboxymethyl Cys; variable modifications—N/Q deamidation, oxidized Met, pyro-glu from Q and pyro-glu from E; 2 missed cleavages; peptide mass tolerance of +/−3.5 Da and +/−0.6 Da for the product ions. Scaffold (version 3, Proteome Software Inc., Portland, Oreg.) was used to validate MS/MS based peptide and protein identifications. Peptide identifications were accepted if they could be established at greater than 95% probability and protein identifications were accepted at greater than 99% probability and with unique significant peptide hits (p<0.05). Utilizing these criteria 9 proteins were identified excluding trypsin and keratin (6 of them were membrane proteins). The two proteins identified with the highest protein score were TN-R and PTP-ζ. The Mascot protein score for TN-R (3 matching protein accession numbers: gi|148707401, gi|226958549 or gi|61216646; 139 kDa) was 932 with protein sequence coverage of 15% protein. The protein score for PTP-ζ (gi|124486807) was 555 with 5% coverage.
[0037] Cell Lines, Cell Culture Conditions and Cell Treatments—
[0038] The U251, SNB19 and U87MG human glioblastoma cell lines were a gift of Dr. J. Segall, Albert Einstein College of Medicine, NY, USA). NIH-3T3-hCSF-1R cells (46) were a gift from Dr. Martine Roussel, St. Jude Children's Research Hospital, Memphis, Tenn. Mouse BAC1.2F5 macrophages (47) were cultured in 36 ng/ml hCSF-1 as described (48). U251 cells were cultured in DMEM-high glucose (GIBCO, Grand Island, N.Y., USA) supplemented with 10% FCS and passaged when confluent. Prior to stimulation with hIL-34 or hPTN, cells were depleted of growth factors by incubation in DMEM-high glucose supplemented with 0.2% BSA for 16 h, except where otherwise indicated. Following stimulation, cells were washed in ice-cold PBS and recovered by scraping and centrifugation, except where otherwise indicated. For chABC-treatment, serum-starved U251 cells were incubated with 4.2 U/ml chABC (37° C., 1 h 30′) and washed extensively, before processing for flow cytometry as described below. For treating membrane lysates, 0.3 U/ml chABC was used.
[0039] Generation of U251 PTP-ζ Knock-Down (KD) Cells—
[0040] Lentiviral particles (5×10 4 IFU) carrying a pool of three different PTP-ζ shRNA or scrambled shRNA plasmids (Santa Cruz Biotechnology, CA, USA) were used to infect 3×10 4 U251 cells (50% confluent) in the presence of 5 μg/ml polybrene in 6-well dishes (37° C., 16 h). Vector-containing cells were selected using 5 μg/ml of puromycin dihydrochloride and the resistant colonies were further sub-cloned by serial dilution method in 96-well plates. The efficiency of knock-down was estimated by western blotting whole cell lysates from the puromycin resistant clones.
[0041] Immunoprecipitation and Western Blot Analysis—
[0042] Membrane fractions of mouse brain and of BAC1.2F5 macrophages, NIH-3T3-hCSF-1R cells or U251 cells were solubilized in homogenization buffer (65 mM Tris, 150 mM sodium chloride, 1 mM EDTA, 10 μg/ml aprotinin, 10 μg/ml leupeptin and 1 mM benzamidine, pH 7.4) containing the appropriate concentration of OG (brain membrane 2%; cell membrane 1%) and incubated (4° C., 16 h) with either immobilized purified polyclonal rabbit anti-mIL-34 antibody beads (preincubated with mIL-34), biotinylated mIL-34, biotinylated hIL-34 (a gift from FivePrime Therapeutics, Inc., CA, USA), or anti-hCSF-1R antibodies. The biotinylated IL-34 complexes were recovered by incubation with neutravidin-agarose and SDS eluates of IL-34 pull-down and immunoprecipitates analyzed by SDS-PAGE and western blotting (WB). For co-immunoprecipitation experiments, mouse brain membrane lysates were pre-incubated with mIL-34 (4° C., 16 h), prior to incubation with anti-PTP-ζ (3F8) antibodies. For stimulation and/or immunoprecipitation experiments, serum-starved U251 cells were incubated with hPTN or hIL-34 (120 ng/ml) at 37° C. and NP-40 cell lysates (using 1% NP-40, 10 mM Tris HCl, 50 mM NaCl, 30 mM Na 4 P 2 O 7 , 50 mM NaF, 100 μM Na3VO4, 5 μM ZnCl 2 , 1 mM benzamidine, 10 μg/ml leupeptin, and 10 μg/ml aprotinin, pH 7.2) were subjected to immunoprecipitation using antibodies to FAK and paxillin.
[0043] Flow Cytometry—
[0044] For cell-surface IL-34 binding, serum-starved U251 cells were gently harvested with 2 mM EDTA in PBS, pH 7.4, washed and 1×10 6 cells were pre-incubated with a 10 molar excess of hIL-34 in Hank's Balanced Salt Solution (HBSS) (Life Technologies) in the presence of 1% BSA (4° C., 1 h). After extensive washing, specific IL-34 binding was detected by incubating the cells with 2 μg/ml biotinylated hIL-34 (4° C., 1 h), and, subsequently, with 5 μg/ml streptavidin-conjugated APC-Cy7. Flow cytometry was performed using FACS Canto II (BD Biosciences, NC, USA) (gating on viable cells). The FlowJo software (Treestar, USA) was used for data analysis. For detection of hCSF-1R expression, serum-starved 2×10 5 U251 cells were incubated with 5 μg/ml rat anti-hCSF-1R monoclonal antibody (2-4A5) or control rat IgG 1 (e-Biosciences, CA, USA) (4° C., 45′), then subsequently incubated with 5 μg/ml FITC-conjugated F(ab′)2-anti-Rabbit IgG (e-Biosciences, CA, USA) prior to flow cytometric analysis as previously described. For the analysis of FLAG-tagged IL-34 and CSF-1 binding to U251 cells by flow cytometry, the expression, purification and quantitation of the concentrations of IL-34-FLAG and CSF-1-FLAG proteins in the medium of the transfected 293T cells, as well as the detection of cell binding with biotin-labeled anti-FLAG M2 antibody, were carried out as described (17).
[0045] Cell Proliferation and Clonogenic Assays—
[0046] U251 cells were seeded at 25% confluency in DMEM-high glucose supplemented with 10% FCS in 24-well tissue culture dishes. 24 h later, cells were washed twice with PBS and medium was replaced with DMEM-high Glucose supplemented with 1% FCS and vehicle (PBS) or hIL-34 (20 ng/ml) or hPTN (20 ng/ml). Cell proliferation was assessed by counting viable (Trypan-Blue excluding) cells harvested at the indicated times. For the clonogenic assays, semi-confluent U251 cells were exposed to a 16 h pulse of hPTN (20 ng/ml), hIL-34 (20 ng/ml) or vehicle (PBS). After that, cells where harvested by Accutase digestion, filtered through a 40 μm mesh to ensure single cellularity and subsequently seeded at 1000 cells/well into 6-well dishes in the presence of 25% conditioned medium (from the 16 h pulse). The number of colonies composed of >50 cells was scored by crystal violet staining 8 days later.
[0047] Cell Migration Assays—
[0048] For wound healing assays, serum-starved (16 h) monolayer cultures of U251 cells were scratched and the wound allowed to heal in the continued absence of serum and in the presence of either hPTN or hIL-34 (200 ng/ml). For haptotactic migration assays, 10 5 serum-starved U251 cells were assayed (37° C., 4 h) in a 24-well transwell chamber. Inserts were pre-coated with BSA (20 μg/ml, no growth factor) or hPTN (5 μg/ml) or hIL-34 (10 μg/ml) for 2 h at room temperature prior to the assay. For the random migration studies (37° C., 4 h), hPTN or hIL-34 (1 μg/ml) was added to both sides of the transwell chamber. Cells were scraped from the upper side of the chamber and the lower side was stained with DAPI and phalloidin. Phalloidin-stained cells were counted using a fluorescence microscope.
[0049] Nanoelectrospray LC-MS/MS Analyses and Protein Identification—
[0050] Tryptic digests were loaded and separated using the UltiMate, FAMOS, Switchos nano-HPLC system (LC Packings, Dionex; Sunnyvale, Calif.), connected on-line to a LTQ Linear Ion Trap mass spectrometer (Thermo Fisher Scientific, Waltham, Mass.) and equipped with a nanospray source. The mobile phases consisted of 5% acetonitrile/water, 0.1% formic acid (A) and 80% acetonitrile/water, 0.1% formic acid (B). After injection (15 μL of sample) and loading onto a C18 trap column, 0.3 mm I.D.×5 mm, the tryptic peptides were separated on a C18 analytical HPLC column (75 μm I.D.×15 cm; Pepmap, 3 μm, 100 Å; LC Packings, Dionex; Sunnyvale, Calif.). The flowrate for loading and desalting was 15 μL/min for 30 minutes while the analytical separation was performed at 250 ηL/min. The gradient used was: 2% to 55% B in 65 min; hold at 55% B for 10 minutes; increase to 95% B in 5 min and hold at 95% B for 5 minutes. The HPLC eluent was electrosprayed into the LTQ using the nanospray source. After an initial MS-survey scan, m/z 300-1800, MS/MS scans were obtained from three most intense ions using a normalized collision-energy of 35%. DTA files were generated from the raw data files, merged and searched against all species of the NCBInr database (Jul. 2, 2010) with Mascot (version 2.3). The search parameters used were: fixed modification—carboxymethyl Cys; variable modifications—N/Q deamidation, oxidized Met, pyro-glu from Q and pyro-glu from E; 2 missed cleavages; peptide mass tolerance of +/−3.5 Da and +/−0.6 Da for the product ions. Scaffold (version 3, Proteome Software Inc., Portland, Oreg.) was used to validate MS/MS based peptide and protein identifications. Peptide identifications were accepted if they could be established at greater than 95.0% probability and protein identifications were accepted at greater than 99.0% probability and unique significant peptide hits (p<0.05). With these criteria 9 proteins were identified excluding trypsin and keratin (6 of them were membrane proteins). The 2 proteins identified with the highest protein score were TN-R and PTP-ζ. The Mascot protein score for TN-R (3 matching protein accession numbers: gi|148707401, gi|226958549 or gi|61216646; 139 kDa) is 932 with protein sequence coverage of 15% protein. The protein score for PTP-ζ (gi|124486807) is 555 with 5% coverage.
[0051] PTP-ζ shRNA Sequences are as Follows—
[0000]
Hairpin sequence (SEQ ID NO: 1):
5′-GATCCCCAGATTTCTACCACAACATTCAAGAGATGTTGTGGTAGAA
ATCTGGTTTTT-3′
Corresponding siRNA sequences:
Sense:
(SEQ ID NO: 2)
5′-CCAGAUUUCUACCACAACATT-3′
Antisense:
(SEQ ID NO: 3)
5′-UGUUGUGGUAGAAAUCUGGTT-3′
Hairpin sequence (SEQ ID NO: 4):
5′-GATCCCCACAGAGATGGTTCTGTATTCAAGAGATACAGAACCATCT
CTGTGGTTTTT-3′
Corresponding siRNA sequences:
Sense:
(SEQ ID NO: 5)
5′-CCACAGAGAUGGUUCUGUAtt-3′
Antisense:
(SEQ ID NO: 6)
5′-UACAGAACCAUCUCUGUGGtt-3′
Hairpin sequence (SEQ ID NO: 7):
5′-GATCCCGAAGGAACTGTCAACATATTCAAGAGATATGTTGACAGTT
CCTTCGTTTTT-3′
Corresponding siRNA sequences:
Sense:
(SEQ ID NO: 8)
5′-CGAAGGAACUGUCAACAUAtt-3′
Antisense:
(SEQ ID NO: 9)
5′-UAUGUUGACAGUUCCUUCGtt-3′.
[0052] Surface Plasmon Resonance (SPR) Binding Analyses—
[0053] SPR binding analyses were performed at 25° C. on Biacore instruments. For binding of hIL-34 and hCSF-1 to immobilized hPTP-ζ- and hCSF-1R-ECD-Fcs (Biacore T100), all flow cells of a CM4 sensor chip were activated with EDC/NHS (7 min, 10 μl/min) and recombinant Protein A (Pierce, 21184, 50 μg/ml in 10 mM Na acetate, pH 4.5) was applied (7 min, 10 μl/min) Following immobilization (≧2500 RU of Protein A per flow cell), all flow cells were blocked with 1M ethanolamine-HCl, pH 8.5. hPTP-ζ-ECD-Fc (25 μg/ml) and hCSF-1R-ECD-Fc (7 μg/ml) in HBSP were captured (˜300 RU and 97 RU respectively) on individual flow cells and binding analyses performed with different concentrations of recombinant hCSF-1 or hIL-34 in HBSP+ or HBSP+ with 3 μg/ml CS (shark cartilage, Sigma, C4384). The protein A surface was regenerated with 10 mM Glycine-HCl, pH 1.5. For binding of hIL-34 to brevican, different concentrations of hIL-34 in HBSP+ were passed over brevican immobilized on the chip. Binding of hTN-R to IL-34 and to hPTP-ζ ECD-Fc (Biacore 3000) was carried out at 25° C. by immobilizing IL-34 (pH 7.0) and hPTP-ζ ECD-Fc (pH 4.05) directly onto flow cells of a CM5 sensor chip (≧2800 RU per flow cell) and passing over different concentrations of hTN-R. Kds were calculated according to the steady state model using BIAevaluation Software (GE Lifesciences). All sensorgrams were double-referenced.
[0054] Immunofluorescence Microscopy—
[0055] Anesthetized mice were transcardially perfused with ice-cold 0.25 mg/ml heparin in PBS (10 ml) followed by 4% paraformaldehyde (50 ml), their brains harvested, post-fixed overnight in 4% PFA, equilibrated in 20% sucrose, flash frozen in a cryomatrix resin and stored at −80° C. prior to use. For immunofluorescence microscopy, specimens were cryosectioned (30 μm sections), immunostained with a mature neuronal marker (NeuN, mIgG1, 1:100, Millipore); an adult neural stem cell marker (GFAP, mouse IgG2b, 1:300, Millipore); IL-34 (polyclonal rabbit IgG, 1:500, Five Prime Therapeutics, CA, USA); PTP-ζ (3F8, mouse IgG1, 1:1250, Developmental Studies Hybridoma Bank, IA); TN-R (polyclonal rabbit IgG, 1:50, Santa Cruz Biotechnology, CA); photographed either with an Olympus BX51 microscope (Tokyo Japan) coupled with a Sensicam digital camera (Cooke Corporation, Michigan, USA), or with a Zeiss Duo V2 Laser Confocal Microscope. Images were subsequently processed with Image J and Photoshop CS5 software programs.
[0056] Statistics—
[0057] Student's t test was used to assess the statistical significance of the data sets.
Results
[0058] Mouse IL-34 (mIL-34) Associates with Mouse Brain PTP-ζ and TN-R—
[0059] Compared with the expression patterns of CSF-1 and the CSF-1R, IL-34 expression in postnatal mouse brain, is spatially, temporally and quantitatively distinct (9,14). This prompted a search for additional IL-34 receptor(s) in detergent-solubilized postnatal mouse brain membranes. To identify novel IL-34-interacting proteins, mouse brain membrane lysate, depleted of the known IL-34 receptor, CSF-1R, was subjected to affinity chromatography with mIL-34 non-covalently bound to an immobilized polyclonal rabbit anti-mIL-34 antibody. Bound proteins were eluted with SDS and processed for mass spectrometry (MS). The two eluted proteins identified with highest certainty were PTP-ζ, a cell-surface RPTP and its ECM ligand, TN-R ( FIG. 7 ). SDS-PAGE and silver staining of the SDS eluates of the mIL-34-anti-mIL-34 antibody affinity purification, or of IL-34-associated proteins prepared by the alternative approach of binding to biotinylated-mIL-34 and capturing the complexes with immobilized neutravidin contained a diffuse band of ˜400 kDa, another broad band at ˜225 kDa, as well as 160/180 kDa species ( FIG. 1A , lanes 1-4, upper panel).
[0060] Due to alternative splicing, PTP-ζ exists in three isoforms, one soluble and two membrane-spanning molecules ( FIG. 1B ). The ˜400-kDa band was confirmed by western blotting to cover stainable bands corresponding to both the long (49) and phosphacan isoforms of PTP-ζ (50,51) as well as multimeric TN-R (52). The ˜225-kDa band co-migrated with a band that stained with the 473-HD antibody (42), that sensitively stains the short PTP-ζ isoform and which also stained in the region of the ˜400 kDa band corresponding to the long receptor and the phosphacan isoforms. The 160/180-kDa proteins, with the apparent M r of the monomeric TN-R isoforms (52), co-migrated with the faster bands western blotted with the anti-TN-R antibody ( FIG. 1A , lanes 1-4, lower panels), corresponding to the monomeric TN-R isoforms. To confirm the PTP-ζ binding results, mouse brain membrane lysate was incubated with mIL-34 and a reciprocal co-immunoprecipitation experiment was performed, immunoprecipitating with 3F8, an antibody that recognizes both the soluble and the long membrane-spanning isoforms of rat PTP-ζ (53) ( FIG. 1B ) and western blotting with anti-IL-34 and anti-TN-R antibodies ( FIG. 1C ). These results show that mIL-34 forms a complex with the larger membrane-spanning isoform of PTP-ζ and with TN-R. However, consistent with earlier reports that the TN-R binding to PTP-ζ is ligand-independent (28,54), TN-R binding to PTP-ζ was IL-34-independent ( FIG. 1C ).
[0061] SPR analysis of hIL-34 binding to the full-length hPTP-ζ ECD-Fc (Kd˜10-7M) and the hCSF-1R-ECD-Fc (Kd˜10-12M) revealed dose-dependent binding to both, whereas hCSF-1 only bound to the hCSF-1R-ECD-Fc (Kd˜10-11M). Similar analyses of the binding of IL-34 to two other proteoglycans identified by MS, hTN-R (Kd˜10-6M) and human brevican (Kd=3×10-6M), revealed lower affinity binding, whereas the interaction of TN-R with the hPTP-ζ ECD-Fc was of higher affinity (Kd˜10-8M), but lower than previously reported (28,54).
[0062] Human IL-34 (hIL-34) Binds to Cell-Surface PTP-ζ on U251 Glioblastoma Cells—
[0063] Since membrane-spanning PTP-ζ, rather than TN-R, is a known signal-transducing receptor for several ligands (24-28), it was determined whether PTP-ζ also functions as a receptor for IL-34. As PTP-ζ is upregulated in human glioblastomas (38-40), glioblastoma cell lines U251, SNB19 and U87MG were tested for PTP-ζ expression. All the tested cell lines expressed high levels of PTP-ζ. U251 was selected for human IL-34 (hIL-34)-binding studies since it does not express the CSF-1R ( FIG. 8 ). Supporting the observations in mouse brain membrane ( FIG. 1A ), biotinylated-hIL-34 primarily formed complexes with the long, membrane-spanning, ˜400 kDa PTP-ζ (50) and to a lesser extent with the non-glycosaminoglycanylated 300 kDa (55) and the short 220 kDa (49) isoforms ( FIG. 2A ) in U251 membrane lysates. However, TN-R was not observed in the biotinylated-hIL-34 pull-down fractions of U251 membranes, suggesting that IL-34 probably binds to PTP-ζ in a TN-R-independent manner. Clones stably-expressing PTP-ζ shRNA (KD cells) expressed lower levels of PTP-ζ protein than clones expressing scrambled shRNA (scrambled cells) ( FIG. 2B ). Scrambled cells expressed higher levels of total soluble PTP-ζ than uninfected cells, indicating that lentiviral infection per se causes cellular PTP-ζ upregulation. Consistent with the dependence of IL-34 binding on PTP-ζ expression, flow cytometric studies demonstrated that the ability of biotinylated hIL-34 to bind to the cell-surface of intact U251 cells was reduced in PTP-ζ KD cells ( FIG. 2C ), particularly in KD2 cells. Thus these results show that hIL-34 binds to PTP-ζ at the surface of intact U251 cells. The specificity and binding of IL-34 to U251 cells was also investigated in binding experiments with FLAG-tagged human IL-34 and FLAG-tagged human CSF-1 (17). At equivalent concentrations, IL-34-FLAG showed robust binding, whereas CSF-1-FLAG failed to bind and IL-34-FLAG exhibited dose-dependent binding, covering a wide concentration range (0.1 pM-1 nM).
[0064] hIL-34 Inhibits U251 Proliferation, Clonogenicity and Motility in a PTP-ζ-Dependent Manner—
[0065] PTP-ζ-signaling is involved in neuronal migration (56) and neuritogenesis (57) in mouse and in the in vitro and in vivo growth of human glioblastomas (39,58,59). As previous studies have shown that PTN inhibits the growth of glioblastomas, to determine the functional relevance of PTP-ζ receptor engagement by IL-34, the effects of IL-34 and PTN were tested on the U251 glioblastoma cells expressing either PTP-ζ or scrambled (control) shRNAs. Either IL-34 or PTN treatment slightly, but significantly, reduced the growth of scrambled U251 cells over a 96 h time period (˜20% reduction in IL-34 vs vehicle-treated control cells, FIG. 3A left panel), while not affecting the growth of the PTP-ζ KD U251 cell lines ( FIG. 3A right panel). The effects of IL-34 and PTN on the colony-forming-ability of infected U251 cells were also examined After a 16 h pulse with IL-34 or PTN, cells were seeded at clonal density and the colonies formed at 8 days were stained and counted. IL-34 or PTN treatment strongly decreased the clonogenicity of scrambled U251 cells (reductions of 68% for IL-34 and 53% for PTN, vs vehicle control cells), without significantly affecting the clonogenicity of PTP-ζ KD cells ( FIG. 3B , left and right panels).
[0066] As PTN was also previously shown to affect glioblastoma cell migration (38-40), to investigate the role of IL-34 in PTP-ζ-mediated glioblastoma cell migration, the effects of IL-34 and PTN were first compared on the wound-healing rates of scrambled and PTP-ζ KD cells ( FIG. 4A ). In the absence of added ligand(s), KD clones exhibited a slower rate of wound healing, indicating that the constitutively active PTP-ζ receptor facilitates U251 migration (e.g. time taken for 50% wound closure [t 50 ] for KD2 cells was >20 h, compared to 5.5 h for scrambled cells). Consistent with ligand-induced inactivation of the receptor (30,32,60), PTN (t 50 =10 h), or IL-34 (t 50 =11.5 h) significantly inhibited wound healing in uninfected cells (vehicle t 50 =7.5 h). Furthermore, neither IL-34, nor PTN could suppress PTP-ζ KD cell wound healing ( FIG. 4B ), thereby indicating that suppression of healing by either ligand is mediated through PTP-ζ. To determine whether IL-34 and PTN suppress directed migration a haptotaxis assay was used ( FIG. 4C ), in which PTP-ζ ligands were shown to be more effective in regulating migration than in a conventional chemotaxis assay (61,62). Both IL-34 as well as PTN, when coated on the bottom of the membrane, suppressed migration of U251 cells ( FIG. 4C ). To determine whether IL-34 and PTN also inhibit random migration, migration of the cells was examined through membranes containing these growth factors on both sides. Both IL-34 as well as PTN inhibited the random migration of the cells ( FIG. 4D ). Together, these results demonstrate that IL-34 suppresses proliferation, clonogenicity and motility of U251 cells in vitro, in a PTP-ζ-dependent manner.
[0067] hIL-34 Enhances PTP-ζ-Mediated Tyrosine Phosphorylation of FAK and Paxillin in U251 Cells—
[0068] To function as a receptor for IL-34, IL-34 binding to cell surface PTP-ζ should trigger intracellular signaling. Consistent with the reduction of PTP-ζ phosphatase activity by ligand binding (30,33,60), PTP-ζ ligand binding has previously been shown to trigger intracellular protein tyrosine phosphorylation (31,32,34,35). Following incubation of U251 cells with PTN or IL-34 for various times at 37° C., a similar ligand-induced tyrosine phosphorylation of proteins was observed, including those with apparent M r s of ˜190, ˜125, ˜120, ˜70 and ˜42 kDa, that peaked within the first 5 minutes of stimulation ( FIG. 5A ). PTP-ζ ligands have been shown to increase the tyrosine phosphorylation of FAK, in lung and prostate carcinomas and endothelial cells (31,37,40) and of paxillin, in osteoblastic cells (63). Either PTN or IL-34 also increased the tyrosine phosphorylation of FAK (˜125 kDa) and paxillin (˜70 kDa) in U251 cells ( FIGS. 5 A, B). In contrast, there was no detectable increase in the tyrosine phosphorylation of the putative PTP-ζ substrates, β-catenin or β-adducin (32,34), in response to either ligand. IL-34-mediated activations of FAK and paxillin were abolished in the PTP-ζ-KD2 cell lines ( FIG. 5C ), demonstrating that tyrosine phosphorylation of these proteins, induced by IL-34, is mediated by PTP-ζ.
[0069] hIL-34 Binds to PTP-ζ in a Chondroitin Sulfate-Dependent Manner—
[0070] PTP-ζ is a proteoglycan receptor for several ligands (24-28) Furthermore, the PTP-ζ CS chains are known to affect binding to some of these ligands (25,29). The possible requirement of CS for IL-34 binding was therefore tested. Consistent with the previously reported presence of CS on PTP-ζ (19,64), treatment of solubilized U251 membranes with chondroitinase ABC increased the mobility of a significant fraction of the large PTP-ζ isoform ( FIG. 6A ). To determine the requirement of CS for cell surface binding, intact U251 cells were incubated with enzyme buffer alone, or with chondroitinase ABC, to remove cell surface CS. Treatment with chondroitinase ABC reduced binding of biotinylated IL-34 to the level seen in IL-34 competed cells (background levels) ( FIG. 6B ). Pre-incubation of U251 cells with a 16 molar excess of IL-34 blocked the subsequent binding of biotinylated IL-34, whereas pre-incubations with a 16 molar excess of CSF-1, or of PTN, were without effect ( FIG. 6C ). Consistent with the removal of binding sites by preincubation with chondroitinase ABC, pre-incubation of IL-34 with 3 μg/ml of shark cartilage CS blocked IL-34 inhibition of biotinylated IL-34 binding ( FIG. 6C ). Thus the CS GAG moiety of PTP-ζ is involved in IL-34 binding. SPR analysis further confirmed the inhibition by CS.
[0071] Comparative Expression Profiles of PTP-ζ, TN-R and IL-34 in Adult Brain—
[0072] Previous studies have shown that PTP-ζ is primarily expressed in neural progenitors and glial cells (21-23) as well as in a subset of cortical neurons (22,25). The expression of TN-R overlaps with PTP-ζ expression in rostral brain regions (77-79). IL-34 expression is primarily observed on mature neurons (9,16,76), including regions of the brain where PTP-ζ is expressed (23). IL-34 expression profiles are distinct from those of its cognate receptor, CSF-1R and also of CSF-1, and that it is preferentially increased in specific areas of early postnatal and adult forebrain, thereby suggesting the presence of an alternative signaling receptor (9). As PTP-ζ functions as a cell-surface receptor for IL-34 and also interacts with TN-R, the expression profiles of IL-34, PTP-ζ and TN-R were analyzed in 8-10 week-old mouse brains. PTP-ζ and TN-R were co-localized in OB, cerebral cortex, RMS and the CA3 region of the hippocampus that have previously been shown to express IL-34 (9). In addition, PTP-ζ expression remained prominent in distinct subcortical structures (thalamic and subthalamic nuclei), midbrain and brain stem nuclei (inferior colliculus, pontine nuclei, locus coeruleus and vestibular nuclei), as well as the cerebellum, and displayed distinct co-localization patterns with both IL-34 and TN-R. Mature post-mitotic neurons of the cerebrum were labeled by all three of these markers. These observations are consistent with a previous study that localized IL-34 expression preferentially to mature neurons of the adult cerebral cortex, extending from layers 2-5. In addition, IL-34 and PTP-ζ co-localization was particularly prominent in layer 5 of the cortex. Consistent with the existence of the secreted PTP-ζ isoform, PTP-ζ expression was also observed in the ECM of the cerebral cortex in concert with IL-34. IL-34 and PTP-ζ appeared to be uniformly distributed in the ECM of layer 5 and at the periphery of mature neuronal cell bodies. In contrast, in cortical layer 6, PTP-ζ expression was reduced in the ECM and neuronal soma, whereas IL-34 expression was virtually absent. Expression of TN-R was evident in cerebral cortical layers 2-5, most prominently in layer 4, where it was co-localized with IL-34 in both the ECM and at the periphery of mature neuronal somas. Its cellular and extra-cellular expression decreased in cortical layer 5. Finally, in contrast to the expression profiles of IL-34 and TN-R, PTP-ζ staining was also seen in GFAP+ adult neural stem cells present in the anterior SVZ, as well as in those neural species migrating through the RMS to the OB (21,23), but not in GFAP+ astrocytes in the CC.
DISCUSSION
[0073] The differential and higher expression of IL-34, compared to CSF-1 and CSF-1R expression in brain coupled with the more pronounced effects of IL-34 compared with CSF-1 on neural progenitor cell self-renewal and differentiation (9,14), raised the possibility that IL-34 might signal via an alternate receptor. The present studies identified PTP-ζ, a cell-surface CSPG, as a second functional receptor for IL-34. IL-34 selectively interacts with PTP-ζ in membrane lysates from both mouse brain as well as U251 human glioblastoma cells. It binds to intact U251 cells, stimulates their phosphotyrosine signaling and suppresses their tumorigenic properties in a PTP-ζ-dependent manner. Furthermore, IL-34, but not CSF-1, binds PTP-ζ in vitro (K a ˜10 −7 M) and at the cell surface and whereas IL-34 and CSF-1 compete for binding to the CSF-1R (14,65,66), pre-incubation with a 16-molar excess of CSF-1 failed to compete for IL-34 binding to U251 cells. Thus PTP-ζ fulfills the criteria required for it to function as the postulated IL-34 receptor.
[0074] PTP-ζ is primarily expressed on neural progenitor and glial cells (21-23), as well as on a subset of cortical neurons (22,25). In contrast, IL-34 is expressed primarily on neurons (9,16) and also in the regions of the brain where PTP-ζ is expressed (23). Interestingly, IL-34 signaling via PTP-ζ in U251 glioblastoma cells causes a suppression of clonogenicity, similar to the effect of CSF-1 or IL-34 on isolated CSF-1R-expressing neural progenitors (9). This suppression of clonogenicity is correlated with stimulation of cellular tyrosine phosphorylation in either setting. Indeed, IL-34 was shown to be significantly more active in suppressing neural progenitor cell proliferation than CSF-1 (9), consistent with an additional action of IL-34 via the PTP-ζ receptor on the neural progenitor cells.
[0075] PTP-ζ-signaling plays a contrasting role in hematopoietic stem cells, leading to their expansion (67). A positive regulatory role of PTP-ζ in proliferation and migration was also reported in some glioblastomas (31,40), which could reflect the role of other known PTP-ζ co-receptors, such as the integrins β1 (63) and β3 (38), in governing these biological responses. Addition of IL-34 to U251 cells led to an increase in the tyrosine phosphorylation of FAK and paxillin and a suppression of cell motility. Although an increase in tyrosine phosphorylation of FAK is associated with an increase in proliferation and motility in other cells, it has been shown to inhibit these responses in glioblastomas (68). Also, similar to the present observations in U251 cells, increased tyrosine phosphorylation of paxillin is correlated with inhibition of motility in macrophages (69) and FAK (Y397) dephosphorylation promotes tumor metastasis (68). Thus, signaling via the PTP-ζ receptor can have contrasting biological effects in specific cellular contexts, possibly dependent on the differential expression of PTP-ζ co-receptors and the activation of specific signaling pathways.
[0076] In view of the striking dependence of the IL-34-PTP-ζ interaction on the CS GAG chain, it was of interest that IL-34 also bound to other CS and HS proteoglycans with low affinity. The CS inhibition of PTP-ζ binding and the finding that binding to brevican and glypican was effectively blocked by heparin, suggest that the low affinity binding of IL-34 to proteoglycans involves the electrostatic interactions between IL-34 and the proteoglycan GAG chains and that the nature of the GAG chain is the likely determinant of this interaction. This electrostatic interaction may also be an important part, but not the sole component, of the high affinity interaction of IL-34 with PTP-ζ and the reason for the CS inhibition that was observed.
[0077] Like IL-34, PTN also exhibits GAG-dependent binding to PTP-ζ. However, in contrast to IL-34, CS-C, but not shark cartilage CS, inhibits this binding (25). Furthermore, competition experiments showed that PTN fails to compete for the binding of IL-34 ( FIG. 6C ), suggesting that IL-34 binding could involve a different PTP-ζ CS GAG-moiety, not recognized by PTN. Interestingly, the CS-A replaces CS-C on the PTP-ζ receptor during development from embryonic to post-natal brain and this is correlated with a decrease in the expression of PTN (64,70). In contrast, IL-34 expression increases progressively during brain development (9).
[0078] The identification of PTP-ζ as a novel receptor for IL-34 necessitates a reevaluation of the possible role of IL-34/PTP-ζ signaling in tissues in which both ligand and receptor are expressed. Obviously the CNS is an important organ system because of the significant expression of both IL-34 and PTP-ζ in brain and because PTP-ζ has been implicated in several disease settings in the CNS. For example, it is expressed in remyelinating oligodendrocytes (OL) and PTP-ζ-deficient mice display a delayed recovery from demyelinating lesions in a model of experimental autoimmune encephalomyelitis (71). Furthermore, the soluble PTP-ζ isoform has been shown to be necessary for maturation for OL progenitors to differentiated myelin-secreting oligodendrocytes in vitro (72) and PTP-ζ-deficient mice exhibit increased myelin breakdown (73). In addition, PTPRZ1 gene in humans is a schizophrenia-susceptibility gene (74) and PTP-ζ regulates tyrosine phosphorylation of voltage-gated sodium channels in neurons (75). Given the present demonstration that IL-34 modulates tumorigenic properties of glioblastoma cell line U251, the fact that PTP-ζ is expressed in neuroblastomas (18) and other tumors (37,40), such as prostate and lung cancer, is highly relevant. IL-34 is also important for Langerhans cell development (16, 76), probably via RPTP-zeta.
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Methods are disclosed for identifying activators and inhibitors of actions of interleukin-34 (IL-34) that are independent of the colony stimulating factor-1 (CSF-1) receptor (CSF-1R) and play a role in development, homeostasis and disease.
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FIELD OF THE INVENTION AND RELATED ART
[0001] The present invention relates to a liquid jet head chip which jets liquid from its liquid ejection openings, and a manufacturing method therefor.
[0002] There are various liquid jet head chips which jet liquid from their liquid ejection openings. Among these liquid jet head chips, an ink jet head chip has been most widely known.
[0003] There has been known an ink jet head chip manufacturing method, such as the one recorded in Japanese Laid-open Patent Application H10-13849, which forms the common ink delivery channel of an ink jet head chip by anisotropic etching.
[0004] There has also been known another ink jet head chip manufacturing method, which is recorded in Japanese Laid-open Patent Applications H05-330066 and H06-286149. This method has been known as an ink jet head chip manufacturing method for very precisely forming the ink passages of an ink jet head chip, at a high density. There is also the ink jet head chip manufacturing method recorded in Japanese Laid-open Patent Application H10-13849. According to this application, the common ink delivery channels of an ink jet head chip is formed with a combination of different types of anisotropic etching.
[0005] In the case of an ink jet head chip, in accordance with the prior art, which jets ink in the direction perpendicular to the heat generating surface of a heat generating resistor, the electrodes of the ink jet head chip, which are for supplying heat generating resistors on the substrate of the ink jet head chip, with electricity, are connected to an external wiring plate, on the surface of the substrate of the ink jet head chip, which has the ink ejection openings. That is, the electrical joint is on the surface of the substrate of the ink jet head chip, which has the ink ejection openings. Placing the electrical joint on the surface of the substrate of an ink jet head chip unavoidably creates bumps on the surface, making it necessary to increase the distance between the surface having the ink ejection openings and the sheet of recording paper, as recorded in Japanese Patent Application Publication H08-25272. This has been problematic in that when this type of ink jet head chip is used for recording, its electrical joint is in the space (gap) between the ink ejection openings and the sheet of paper (recording medium), affecting thereby an ink jet recording apparatus in recording performance.
[0006] Thus, it has been thought of making electrical connection between the abovementioned electrodes and external wiring plate, on the opposite surface of the substrate from the surface having the ink ejection openings, in order to prevent the formation of the bumps on the surface having the ink ejection openings. One of the embodiments of this thought is recorded in Japanese Laid-open Patent Application 2006-321222. According to this application, the ink jet head chip is provided with electrodes (which hereafter will be referred to as through electrode) which extend through the substrate of the ink jet head chip from the surface having the ink ejection openings to the opposite surface, and the electrical connection between the abovementioned electrodes of the ink jet head chip and the external wiring plate is made on the surface opposite from the surface having the ink ejection openings.
[0007] FIG. 6 shows an example of an ink jet head chip, which employs through electrodes. FIG. 6A is a schematic plan view of the ink jet head chip employing the through electrodes. The through electrodes are not shown in FIG. 6A . FIG. 6B is a schematic sectional view of the ink jet head chip, at a plane which coincides with Line X 3 -Y 3 in FIG. 6A .
[0008] The substrate 301 of the ink jet head chip has a common ink delivery channel 302 , which is in the form of an elongated trapezoid, the lengthwise direction of which is parallel to the row of heat generating resistors, which corresponds to the recording width of the ink jet head chip. In order for an ink jet recording apparatus to be increased in recording speed, it needs to be increased in the width of one of the multiple passes which must be made across a sheet of recording medium by the ink jet head chip of the ink jet recording apparatus to complete a single copy of an image. However, increasing an ink jet head chip in the recording width, that is, one of the abovementioned passes, requires lengthening the row of ink ejection openings, which in turns requires lengthening the common ink delivery channel 302 . The longer the common ink delivery channel 302 , the greater the deformation of the center portion of the common ink delivery channel 302 . Further, the greater the deformation, the more likely it is for the ink passage formation plate, or the like, to separate from the substrate 301 , and/or crack. Thus, in the case of an ink jet head chip in accordance with the prior art, the ink passage formation plate on the substrate 301 sometimes separated from the substrate 301 , and/or the substrate 301 itself sometimes cracked.
SUMMARY OF THE INVENTION
[0009] The primary object of the present invention is to provide a liquid jet head chip which employs through electrodes, but, does suffer from the problem that the center portion of its substrate deforms, and also, to provide a method for manufacturing the liquid jet head.
[0010] According to an aspect of the present invention, there is provided a liquid ejection head comprising a substrate including, at a surface thereof, an ejection energy generating means for generating ejection energy for ejecting liquid, a flow path forming member provided with an ejection outlet, said substrate further including a liquid supply opening, penetrating therethrough, for supplying the liquid to be ejected by the ejection energy to a flow path of said flow path forming member; a reinforcing member connected to a back side of said substrate; a first penetrating electrode, penetrating said substrate from a front side to the back side thereof, for supplying electric power to said ejection energy generating means; and a second penetrating electrode penetrating said reinforcing member from a front side to a back side thereof, said second penetrating electrode being electrically connected to said first penetrating electrode.
[0011] These and other objects, features, and advantages of the present invention will become more apparent upon consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1A is a schematic plan view of the ink jet head chip in one of the preferred embodiments of the present invention.
[0013] FIG. 1B is a schematic sectional view of the ink jet head chip shown in FIG. 1A , at a plane which coincides with Line X 1 -Y 1 in FIG. 1A .
[0014] FIG. 1C is a schematic sectional view of the ink jet head chip shown in FIG. 1A , at a plane which coincides with Line X 2 -Y 2 in FIG. 1A .
[0015] FIG. 2A is a schematic plan view of a silicon wafer on which multiple ink jet head chips have been formed in a grid pattern.
[0016] FIG. 2B is an enlarged schematic plan view of one of the ink jet head chips yielded by dicing the silicon wafer shown in FIG. 2A .
[0017] FIG. 3A is a schematic plan view of a silicon wafer on which multiple reinforcement plates have been formed in a grid pattern.
[0018] FIG. 3B is an enlarged schematic plan view of one of the reinforcement plates yielded by dicing the silicon wafer shown in FIG. 3A .
[0019] FIG. 4A is a schematic plan view of the front surface of a silicon wafer after multiple reinforcement plates were formed thereon in a grid pattern, and then, another silicon wafer on which multiple ink jet head chips had been formed in a grid pattern was bonded to the former so that the front surface of the latter faced the back surface of the former.
[0020] FIG. 4B is a schematic plan view of the back side of one of the ink jet head chips yielded by dicing the bonded combination of the two silicon wafers shown in FIG. 4A .
[0021] FIG. 5A is an enlarged schematic plan view of one of the modified versions of the ink jet head chip, in accordance with the present invention.
[0022] FIG. 5B is a schematic sectional view of the ink jet head chip shown in FIG. 5A , at a plane which coincides with Line X 1 -Y 1 in FIG. 5A .
[0023] FIG. 5C is a schematic sectional view of the ink jet head chip shown in FIG. 5A , at a plane which coincides with Line X 2 -Y 2 in FIG. 5A .
[0024] FIG. 6A is a schematic plan view of an example of ink jet head chip in accordance with the prior art.
[0025] FIG. 6B is a schematic sectional view of the ink jet head chip shown in FIG. 6A , at a plane which coincides with Line X 3 -Y 3 in FIG. 6A .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0026] Hereinafter, the preferred embodiments of the present invention will be described with reference to the appended drawings.
[0027] The liquid jet head chips in the following embodiments of the present invention are ink jet head chips. An ink jet head is one of the various forms of liquid jet head, and therefore, an ink jet head chip is one of the variations forms of liquid jet head chip. Similarly, the ink, ink ejection opening, common ink delivery channel, and ink delivering member of the ink jet head chip, are equivalent to the liquid, liquid ejection opening, common liquid delivery channel, and liquid delivering member of a liquid jet head chip, respectively. A liquid jet head in accordance with the present invention can be used as a device for ejecting liquid fuel, cosmetic liquid, medicinal liquid, etc.
[0028] FIG. 1A is a schematic sectional view of the ink jet head chip in one of the preferred embodiment of the present invention. Incidentally, first through electrodes 105 are not shown in this drawing. FIG. 1B is a schematic sectional view of the ink jet head chip shown in FIG. 1A , at a plane which coincides with Line X 1 -Y 1 in FIG. 1A . FIG. 1C is a schematic sectional view of the ink jet head chip shown in FIG. 1A , at a plane which coincides with Line X 2 -Y 2 in FIG. 1A .
[0029] The ink jet head chip in this embodiment is made up of a substrate, an ink passage formation plate 104 formed on the substrate. It is also provided with a reinforcement plate 106 , which is a substrate reinforcing member placed on the back surface of the substrate to prevent the common ink delivery channel 102 , which is a through hole extending from the front surface of the substrate to the back surface of the substrate, etc., from deforming. Further, the ink jet head chip in this embodiment is provided with multiple through electrodes 105 (first through electrodes) put through the substrate, and multiple through electrodes 109 (second through electrodes) put though the reinforcement plate 106 to establish electrical connection between the first through electrode 105 and the external electrode(s) of the ink jet head chip.
[0030] In a case where a reinforcement plate having no second through electrode 109 is placed on the back surface of the substrate of the ink jet head chip 101 , which has the first through electrodes 105 , it is impossible to establish electrical connection between the first through electrodes 105 and external electrodes to extend electrical lead wires from the ink jet head chip. As for a solution to this problem, it is possible to directly attach the external lead wires to the first through electrodes 105 , before placing the reinforcement plate having no through electrode, on the back surface of the substrate of the ink jet head chip 101 . However, in order to do so, it must be after the dicing of a silicon wafer 100 a that the reinforcement plate with no through electrode is placed on the back surface of the substrate of the ink jet head chip 101 , making meaningless the reason for providing the ink jet head chip with the reinforcement plate.
[0031] Thus, in the case of the ink jet head chip manufacturing method in this embodiment, multiple first through electrodes 105 are formed through the silicon wafer 100 a , and multiple reinforcement plates 106 are formed on a silicon wafer 100 b so that the reinforcement plates 106 match in position the multiple ink jet head chips formed on the silicon wafer 100 a . Then, the silicon wafer 100 b is bonded to the back surface of the silicon wafer 100 a so that not only the reinforcement plates 106 on the silicon wafer 100 b match in position the precursors of the ink jet head chip on the silicon wafer 100 a , one for one, but also, the first through electrodes 105 put through the substrates 101 silicon wafer 100 a . The multiple reinforcement plates 106 on the silicon wafer 100 b correspond to the multiple precursors of ink jet head chip 101 on the silicon wafer 100 a , one for one. Each reinforcement plate 106 is provided with second through electrodes 109 put through the reinforcement plate 106 so that they can be placed in contact with the first through electrodes 105 put through the silicon substrate 100 a , one for one. Further, the common ink delivery channels 102 are formed through the first silicon wafer 100 a before the silicon wafer having the reinforcement plates 109 is bonded to the silicon wafer 100 a . The multiple ink delivery holes 106 c of the silicon wafer 100 b , which correspond in position to the common ink delivery channels 102 of the silicon wafer 100 a , are formed after the bonding of the silicon wafer 100 b having the reinforcement plates 109 , to the back surface of the silicon wafer 100 a.
[0032] Next, the ink jet head chip in this embodiment will be described in detail.
[0033] First, multiple ink passage formation plate 104 are formed on the front surface 101 a of the silicon wafer 100 a (that is, front surface of substrate of ink jet head chip 101 ) so that each ink passage formation plate 104 has multiple ink ejection holes (openings) 103 and multiple ink passages 104 a dedicated to the ink ejection holes one for one.
[0034] The silicon wafer 100 a is etched so that the substrate of each precursor of the ink jet head chip 101 has the common ink delivery channel 102 for supplying the multiple dedicated ink delivery passages 104 a with ink. Further, there are energy generating means for generating the energy for ejecting from ink ejection holes (openings) 103 , on the front surface 101 a of the substrate of each precursor of the ink jet head chip 101 , being arranged so that they align one for one with the ink ejection holes 103 (openings). More specifically, the ink ejection energy generating means in this embodiment are heat generating resistors 110 , which generate thermal energy as the ink ejection energy. Further, the substrate of the precursor of the ink jet head chip 101 (which hereafter may be referred to simply as ink jet head chip 101 ) is provided with first through electrodes 105 which extend from the front surface 101 a of the substrate of the ink jet head chip 101 to the bottom surface 101 b of the substrate of the ink jet head chip 101 . The first through electrode 105 is the passage through which the electric power for causing the heat generating resistor 110 to generate heat is supplied.
[0035] The reinforcement plate 106 as the member for reinforcing the substrate of the ink jet head chip 101 is a plate for preventing the substrate of the ink jet head chip 101 , which has the common ink delivery channels, from deforming. It is placed on the back surface 101 b of the substrate of the ink jet head chip 101 . The reinforcement plate 106 is provided with the ink delivery through hole 106 c , which corresponds in position to the common ink delivery channel 102 of the substrate of the ink jet head chip 101 . Further, the reinforcement plate 106 is provided with multiple ribs 107 , which extend from one long lateral surface of the ink delivery hole 106 c to the other. The ribs 107 are arranged in parallel in the ink delivery hole 106 c , with the presence of preset intervals. The reinforcement plate 106 is also provided with second through electrodes 109 , which extend from the front surface 106 a of the reinforcement plate 106 to the back surface 106 b of the reinforcement plate 106 .
[0036] There are electrical wires 108 on the surface 106 a of the reinforcement plate 106 , which establish electrical connection between the first through electrodes 105 and second through electrode 109 by coming into contact therewith, as the silicon wafer 100 a (substrate of ink jet head chip 101 ) and the silicon wafer 100 b (substrate of reinforcement plate 106 ) are joined with each other. That is, the electrical connection between the first through electrodes 105 and second through electrodes 109 is established through the electrical wires 108 .
[0037] Next, the method for manufacturing the ink jet head chip in this embodiment will be described.
[0038] First, the steps for manufacturing the ink jet head chip 101 will be described.
[0039] First, the silicon wafer 100 a , which is 300 μm in thickness, is prepared. Then, a layer of TaN, which makes up the heat generating resistors, and a layer of Al, which makes up the electrodes, are formed on the silicon wafer 100 a by sputtering. Then, the heat generating resistors 110 and electrodes are formed with the use of photolithography. The size of each heat generating resistor is 30 μm×30 μm. If necessary, each heat generating resistor may be covered with a protective layer. Next, multiple through holes, which are 50 μm in diameter, are cut through the silicon wafer 100 a by dry etching so that they match in position to the precursors of the ink jet head chip 101 , one for one. Then, the seed film for plating is formed on the surface of each through hole. Then, each through hole is filled with gold by electroplating to form the first through electrode 105 . This completes the process of forming multiple precursors of the ink jet head chip 101 having the heat generating resistors 110 on the front surface of the substrate of the precursor, and the first through electrodes 105 which extend from the front surface of the substrate of the ink jet head chip 101 to the back surface of the substrate of the ink jet head chip 101 . In other words, a substantial portion of the silicon wafer 100 a is turned into multiple precursors of the ink jet head chip 101 , which are arranged in a grid pattern.
[0040] Next, a relatively thick film (15 μm thick) of positive resist, which is for forming the molds for the dedicated ink delivery passage 104 a , which extend from the common ink delivery channel 102 to the ink ejection holes 103 (openings), is coated to a thickness of 15 μm on the front side (surface) of the silicon wafer 100 a (surface 101 a of substrate of ink jet head chip 101 ). Then, the molds having a preset pattern are formed by exposing the positive resist layer, and then, developing the positive resist layer. Then, photosensitive negative epoxy is applied to a thickness of 30 μm to cover the molds on the front side (surface) of the silicon wafer 100 a (surface 101 a of substrate of ink jet head chip 101 ). Thereafter, the layer of negative epoxy is exposed, and then, is developed to form the ink ejection holes 103 which are 25 μm in diameter. Then, the front side of the silicon wafer 100 a is coated with protective resin, and then, the mask for forming the common ink delivery channels 102 by etching is formed on the back surface of the silicon wafer 100 a (back surface 101 b of substrate of ink jet head chip 101 ). Then, the silicon wafer 100 a (precursor of ink jet head chip 101 ) is entirely dipped in liquid etchant which anisotropically etches the silicon wafer (substrate of ink jet head chip 101 ). As a result, each substrate of the ink jet head chip 101 is provided with the common ink delivery channel 102 . Lastly, the resinous protective layer on the front side of the silicon wafer 100 a , and the molds (patterned layer of positive resist) for forming the dedicated ink delivery passage 104 a , are removed, yielding thereby the silicon wafer 100 a having multiple ink jet head chips 101 , each of which is made up of the ink ejection holes 103 , dedicated ink delivery passages 104 a , and heat generating resistors 101 . After the completion of the above described steps, the silicon wafer 100 a has multiple ink jet head chips 101 , which are positioned in a grid pattern. FIG. 2A is a schematic plan view of the silicon wafer 100 a having multiple ink jet head chips 101 which have been formed in a grid pattern, through the above described steps. FIG. 2B is an enlarged schematic plan view of one of the ink jet head chips 101 formed using the silicon wafer 100 a.
[0041] Next, the steps for manufacturing the reinforcement plate 106 will be described.
[0042] First, the silicon wafer 100 b , which is 300 μm in thickness, is prepared. Then, multiple through holes, which are 50 μm in diameter, are cut through the silicon wafer 100 b by dry etching. Next, a film of plating seed is formed on the surface of each through hole. Then, each through hole is filled with gold by electroplating, forming thereby second through electrode 109 . Incidentally, wiring can be formed on the front and rear surfaces of the silicon substrate, during this step. Therefore, the wiring 108 is formed on the front surface of the silicon wafer 100 b (which corresponds to front surface 106 a of reinforcement plate 106 ), of gold by plating, during this step of forming the through electrodes 109 . If necessary, wiring can be formed also on the back surface of the silicon wafer 100 b (back surface 106 b of reinforcement plate 106 ). Next, the through hole 106 c , across which the ribs 107 extend, is formed by dry etching, yielding thereby the silicon wafer 100 b having multiple reinforcement plates 106 , each of which is made up of the wiring 108 and second through electrodes 109 . FIG. 3A is a schematic plan view of the silicon wafer 100 b after the multiple reinforcement plates 106 have been formed in a grid pattern on the silicon wafer 100 b . FIG. 3B is an enlarged schematic plan view of one of the completed multiple reinforcement plates 106 , which the silicon wafer 100 b has.
[0043] After the completion of the above described steps, the ink jet head chips 101 are still parts of a pair of six inch (152.4 mm) silicon wafers, that is, the silicon wafers 100 a and 100 b . Then, the silicon wafers 100 a and 100 b are positioned relative to each other so that the back surface 101 b of the substrate of each ink jet head chip 101 and the front surface 106 a of the corresponding reinforcement plate 106 face each other and align with each other, and also, so that the common ink delivery channel 102 and first through electrodes 105 of each ink jet head chip 101 , align with the through hole 106 c and second through electrodes of the corresponding reinforcement plate 106 , respectively. Then, the two wafers 100 a and 100 b are solidly bonded to each other so that the common ink delivery channel 102 is connected to the through hole 106 c , and electrical connection is established between the first through electrodes 105 and second through electrodes 109 , one for one. Then, the two wafers 100 a and 100 b are kept pressed upon each other in the ambience which is 200° C. in temperature, to ensure that the electrical connection is established between the first through electrode 105 of each ink jet head chip 101 , which is formed of gold, and the wiring 108 of the corresponding reinforcement plate 106 , which is also formed of gold. As a result, electrical connection is reliably established between each ink jet head chip 101 and corresponding reinforcement plate 106 . In other words, electrical connection is established between the heat generating resistors 110 on the front surface 101 a of the substrate of each ink jet head chip 101 and the second through electrode 109 of the corresponding reinforcement plate 106 . FIG. 4A is a schematic plan view of the silicon wafer 100 b after the silicon wafers 100 a and 100 b were bonded to each other so that the back surface of the silicon wafer 100 a faces the front surface of the silicon wafer 100 b . FIG. 4B is an enlarged schematic plan view of one of the ink jet head chip 101 to which the reinforcement plate 106 has been bonded.
[0044] Next, the bonded combination of the silicon wafers 100 a and 100 b is diced to yield multiple ink jet head chips 101 reinforced with the reinforcement plate 106 . Then, each ink jet head chip 101 is sealed across its electrical junction and ink inlet, with sealant. Thereafter, the ink jet head chip 101 is put though the step for attaching an external wiring plate to the ink jet head chip 101 , and step for bonding an ink delivery member to the ink jet head chip 101 , to yield an ink jet recording cartridge.
[0045] As described above, in this embodiment, it is the reinforcement plate 106 that is provided with the second through electrodes 109 . Therefore, the electrical connection between the ink jet head chip 101 and external electrical electrodes can be made on the rear surface 106 b of the reinforcement plate 106 . Also in this embodiment, the reinforcement plate 106 is bonded to the ink jet head chip 101 before the silicon wafer 100 a holding multiple ink jet head chips 101 and the silicon wafer 100 b holding multiple reinforcement plates 106 are diced. Therefore, the common ink delivery channel 102 is prevented from deforming, by the reinforcement plate 106 , even after the dicing of the silicon wafers 100 a and 100 b . Therefore, it does not occur that the ink passage formation plate 104 peels away from the substrate of the ink jet head chip 101 and/or cracks. Further, providing the ink jet head chip 101 with the reinforcement plate 106 enables the ink jet head chip 101 to withstand the thermal stress which occurs during the step for attaching the external wiring plate to the ink jet head chip 101 , and the step for bonding the ink delivery member to the ink jet head chip 101 , preventing thereby the deformation of the common ink delivery channel 102 . That is, in this embodiment, the problem that the common ink delivery channel 102 of the ink jet head chip 101 is deformed after the dicing of the silicon wafer on which multiple ink jet head chips 101 have been formed. Therefore, it is possible to deal with the previously mentioned problem that occurs as an ink jet head chip is increased in recording width to increase an ink jet recording apparatus in recording speed.
[0046] Further, in this embodiment, it is unnecessary to place external electrodes on the surface of the substrate of the ink jet head chip 101 , which faces the front surface 106 a of the reinforcement plate 106 . That is, it is unnecessary to place electrical components on the front surface 101 a of the substrate of the ink jet chip 101 . Therefore, the ink jet head chip 101 in this embodiment can significantly reduce the gap between an ink jet head chip and a sheet of paper as recording medium. The reduction in the distance between an ink jet head chip and recording medium improves an ink jet recording apparatus in the accuracy with which each ink droplet jetted from the ink jet head chip lands on the recording medium, making it possible to improve an ink jet recording apparatus in image quality.
[0047] Incidentally, the reinforcement plate 106 of the ink jet head chip 101 in this embodiment is formed of silicon. Therefore, the ink jet head chip 101 in this embodiment can be modified so that the driving element 211 is placed on the reinforcement plate 106 , as shown in FIG. 5 . FIG. 5A is a schematic plan view of one of the modified versions of the ink jet head chip 101 in this embodiment. FIG. 5A does not show the second through electrodes 109 . FIG. 5B is a schematic sectional view of the ink jet head chip shown in FIG. 5A , at a plane coinciding with Line X 1 -Y 1 in FIG. 5A . FIG. 5 c is a schematic sectional view of the ink jet head chip shown in FIG. 5A , at a plane which coincides with Line X 2 -Y 2 in FIG. 5A .
[0048] The driving element 211 which drives the heat generating resistors 110 , and the wirings 108 a and 108 b , are on the top surface 106 a of the reinforcement plate 106 . The driving element 211 is electrically connected to the first through electrodes 105 through the wiring 108 a , and also, to the second through electrodes 109 through the wiring 108 b . Placing the driving element 211 on the reinforcement plate 106 makes it unnecessary to place the driving element 211 on the substrate of the ink jet head chip 101 , making it possible to reduce the ink jet head chip 101 in size and cost.
[0049] While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the purposes of the improvements or the scope of the following claims.
[0050] This application claims priority from Japanese Patent Applications Nos. 337030/2006 and 288550/2007 filed Dec. 14, 2006 and Nov. 6, 2007 which are hereby incorporated by reference.
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A liquid ejection head includes a substrate including, at a surface thereof, an ejection energy generating means for generating ejection energy for ejecting liquid, a flow path forming member provided with an ejection outlet, the substrate further including a liquid supply opening, penetrating therethrough, for supplying the liquid to be ejected by the ejection energy to a flow path of the flow path forming member; a reinforcing member connected to a back side of the substrate; a first penetrating electrode, penetrating the substrate from a front side to the back side thereof, for supplying electric power to the ejection energy generating means; and a second penetrating electrode penetrating the reinforcing member from a front side to a back side thereof, the second penetrating electrode being electrically connected to the first penetrating electrode.
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FIELD OF THE INVENTION
This invention relates to catalytic hydrocarbon conversion, and more specifically to the use of a catalyst for conversion of heavier polycyclic aromatics such as naphthalene and C 11 aromatics compounds into lighter aromatics such as C 6 , C 7 , C 8 , and C 9 aromatics. The catalyst comprises a solid-acid support with a metal hydrogenation component, and the catalyst effectively processes heavy aromatics while also converting lighter aromatics via transalkylation into desirable xylene species.
BACKGROUND OF THE INVENTION
Xylenes isomers, para-xylene, meta-xylene and ortho-xylene, are important intermediates which find wide and varied application in chemical syntheses. Para-xylene upon oxidation yields terephthalic acid, which is used in the manufacture of synthetic textile fibers and resins. Meta-xylene is used in the manufacture of plasticizers, azo dyes, wood preservers, etc. Ortho-xylene is feedstock for phthalic anhydride production.
Xylene isomer streams from catalytic reforming or other sources generally do not match demand proportions as chemical intermediates, and further comprise ethylbenzene, which is difficult to separate or to convert. Para-xylene in particular is a major chemical intermediate with rapidly growing demand, but amounts to only 20 to 25% of a typical C 8 aromatics stream. Among the aromatic hydrocarbons, the overall importance of the xylenes rivals that of benzene as a feedstock for industrial chemicals. Neither the xylenes nor benzene are produced from petroleum by the reforming of naphtha in sufficient volume to meet demand, and conversion of other hydrocarbons is necessary to increase the yield of xylenes and benzene. Often toluene (C 7 ) is dealkylated to produce benzene (C 6 ) or selectively disproportionated to yield benzene and C 8 aromatics from which the individual xylene isomers are recovered.
A current objective of many aromatics complexes is to increase the yield of xylenes and to de-emphasize benzene production. Demand is growing faster for xylene derivatives than for benzene derivatives. Refinery modifications are being effected to reduce the benzene content of gasoline in industrialized countries, which will increase the supply of benzene available to meet demand. Benzene produced from disproportionation processes often is not sufficiently pure to be competitive in the market. A higher yield of xylenes at the expense of benzene thus is a favorable objective, and processes to transalkylate C 9 aromatics and toluene have been commercialized to obtain high xylene yields.
U.S. Pat. No. 4,341,914 discloses a transalkylation process over mordenite using toluene and C 9 + aromatics, where indane is removed as a poison from fresh feed by distillation. U.S. Pat. No. 4,857,666 discloses a transalkylation process over mordenite and suggests modifying the mordenite by steam deactivation or incorporating a metal modifier into the catalyst.
U.S. Pat. No. 5,763,720 discloses a transalkylation process for conversion of C 9 + hydrocarbons into mixed xylenes and C 10 + aromatics over a catalyst containing zeolites illustrated in a list including amorphous silica-alumina, MCM-22, ZSM-12, and zeolite beta, where the catalyst further contains a Group VIII metal such as platinum.
U.S. Pat. No. 5,942,651 discloses a transalkylation process in the presence of two zeolite containing catalysts. The first zeolite is selected from the group consisting of MCM-22, PSH-3, SSZ-25, ZSM-12, and zeolite beta. The second zeolite contains ZSM-5, and is used to reduce the level of saturate co-boilers in making a benzene product.
U.S. Pat. No. 5,952,536 discloses a transalkylation process using a catalyst comprising a zeolite selected from the group consisting of SSZ-26, Al-SSZ-33, CIT-1, SSZ-35, and SSZ-44. The catalyst also comprises a mild hydrogenation metal such as nickel or palladium, and can be used to convert aromatics with at least one alkyl group including benzene.
U.S. Pat. No. 6,060,417 discloses a transalkylation process using a catalyst based on mordenite with a particular zeolitic particle diameter and having a feed stream limited to a specific amount of ethyl containing heavy aromatics. The catalyst contains nickel or rhenium metal.
U.S. Pat. No. 6,486,372 B1 discloses a transalkylation process using a catalyst based on dealuminated mordenite with a high silica to alumina ratio that also contains at least one metal component. U.S. Pat. No. 6,613,709 B1 discloses a catalyst for transalkylation comprising zeolite structure type NES and rhenium.
Many types of supports and elements have been disclosed for use as catalysts in processes to transalkylate various types of lighter aromatics into xylenes. However, applicants have found that even heavier polycyclic aromatics can be converted into lighter aromatics and be further converted into xylenes via more conventional transalkylation pathways. Indane and C 10 + components, such as naphthalenes, had previously been regarded as coke precursors in conventional transalkylation technologies, but applicants have found a catalyst and a process to convert these components to a great extent, and that permits processing low-value, heavy aromatics into high-value, light aromatics with less stringent feed stream pre-fractionation specifications.
SUMMARY OF THE INVENTION
A principal object of the present invention is to provide a process for the transalkylation of alkylaromatic hydrocarbons. More specifically, the process of the present invention is directed to converting aromatic hydrocarbons with improved conversion of heavy aromatics components such as naphthalene and indane. This invention is based on the discovery that a catalyst based on a solid-acid material in conjunction with a metal component exhibits high effectiveness for conversion when contacted under transalkylation conditions.
Accordingly, a broad embodiment of the present invention is a process for transalkylation of indane and C 10 + aromatics to C 8 aromatics over a catalyst. The catalyst has a solid-acid component such as mordenite, mazzite, zeolite beta, ZSM-11, ZSM-12, ZSM-22, ZSM-23, MFI topology zeolite, NES topology zeolite, EU-1, MAPO-36, MAPSO-31, SAPO-5, SAPO-11, SAPO-41, and silica-alumina. The catalyst also has a metal component.
In another embodiment, the present invention is a process for conversion and transalkylation of heavy aromatics to xylenes over a solid-acid catalyst with a metal component, where the stream ending-boiling-point over the catalyst is reduced by about 5° C. or more. Effective metal components include, for example, platinum, palladium, nickel, tin, lead, iridium, germanium, and rhenium.
In yet another embodiment, the present invention is a fractionation scheme based upon an apparatus practicing the process of transalkylating heavy aromatics with specifications permitting indanes and naphthalenes to come in contact with a metal stabilized solid-acid catalyst.
These, as well as other objects and embodiments will become evident from the following detailed description of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The feed stream to the present process generally comprises alkylaromatic hydrocarbons of the general formula C 6 H (6−n) R n , where n is an integer from 0 to 6 and R is CH 3 , C 2 H 5 , C 3 H 7 , or C 4 H 9 , in any combination. Suitable alkylaromatic hydrocarbons include, for example but without so limiting the invention, benzene, toluene, ortho-xylene, meta-xylene, para-xylene, ethylbenzene, ethyltoluenes, propylbenzenes, tetramethylbenzenes, ethyl-dimethylbenzenes, diethylbenzenes, methylpropylbenzenes, ethylpropylbenzenes, triethylbenzenes, di-isopropylbenzenes, and mixtures thereof.
The feed stream also comprises naphthalene and other C 10 and C 11 aromatics and suitably is derived from one or a variety of sources. Polycyclic aromatics such as the bi-cyclic components including naphthalene, methylnaphthalene, or indane are preferred components for the feed stream of the present invention. Indane, which is also referred to as indan or indene, is meant to define a carbon number nine aromatic species with one carbon six ring and one carbon five ring wherein two carbon atoms are shared. Naphthalene is meant to define a carbon number ten aromatic species with two carbon six rings wherein two carbon atoms are shared. Preferably the polycyclic aromatics are present in amounts above the trace amounts noted in prior art, and these amounts are herein defined as substantial amounts such as greater than about 0.3 wt-% and even more preferably greater than about 0.5 wt-% of the feed stream.
Feed components may be produced synthetically, for example, from naphtha by catalytic reforming or by pyrolysis followed by hydrotreating to yield an aromatics-rich product. The feed stream may be derived from such product with suitable purity by extraction of aromatic hydrocarbons from a mixture of aromatic and nonaromatic hydrocarbons and fractionation of the extract. For instance, aromatics may be recovered from reformate. Reformate may be produced by any of the processes known in the art. The aromatics then may be recovered from reformate with the use of a selective solvent, such as one of the sulfolane type, in a liquid-liquid extraction zone. The recovered aromatics may then be separated into streams having the desired carbon number range by fractionation. When the severity of reforming or pyrolysis is sufficiently high, extraction may be unnecessary and fractionation may be sufficient to prepare the feed stream. Such fractionation typically includes at least one separation column to control feed end point.
The feed heavy-aromatics stream, characterized by C 9 + aromatics (or A 9 + ), permits effective transalkylation of light aromatics such as benzene and toluene with the heavier C 9 + aromatics to yield additional C 8 aromatics that are preferably xylenes. The heavy-aromatics stream preferably comprises at least about 90 wt-% total aromatics, and may be derived from the same or different known refinery and petrochemical processes as the benzene and toluene and/or may be recycled from the separation of the product from transalkylation.
The feed stream is preferably transalkylated in the vapor phase and in the presence of hydrogen. If transalkylated in the liquid phase, then the presence of hydrogen is optional. If present, free hydrogen is associated with the feed stream and recycled hydrocarbons in an amount of from about 0.1 moles per mole of alkylaromatics up to 10 moles per mole of alkylaromatic. This ratio of hydrogen to alkylaromatic is also referred to as hydrogen to hydrocarbon ratio. The transalkylation reaction preferably yields a product having an increased xylene content and also comprises toluene. The conversion of naphthalene over the catalyst is preferably greater than about 80 wt-%, while the conversion of methylnaphthalene is preferably greater than about 75 wt-%. The conversion of indane is preferably greater than about 50 wt-%, and even more preferably greater than about 75 wt-%, all conversions being calculated on a fresh-feed basis.
The feed to a transalkylation reaction zone usually first is heated by indirect heat exchange against the effluent of the reaction zone and then is heated to reaction temperature by exchange with a warmer stream, steam or a furnace. The feed then is passed through a reaction zone, which may comprise one or more individual reactors. The use of a single reaction vessel having a fixed cylindrical bed of catalyst is preferred, but other reaction configurations utilizing moving beds of catalyst or radial-flow reactors may be employed if desired. Passage of the combined feed through the reaction zone effects the production of an effluent stream comprising unconverted feed and product hydrocarbons. This effluent is normally cooled by indirect heat exchange against the stream entering the reaction zone and then further cooled through the use of air or cooling water. The effluent may be passed into a stripping column in which substantially all C 5 and lighter hydrocarbons present in the effluent are concentrated into an overhead stream and removed from the process. An aromatics-rich stream is recovered as net stripper bottoms which is referred to herein as the transalkylation effluent.
To effect a transalkylation reaction, the present invention incorporates a transalkylation catalyst in at least one zone, but no limitation is intended in regard to a specific catalyst other than such catalyst must possess a solid-acid component and a metal component. Without wishing to be bound to any one theory, it is believed that such catalyst selectively saturates at least one ring of the polycyclic aromatic compound, cracks that one ring, which results in a remaining single-ring aromatic compound with alkyl groups that is much more resistant towards further saturation than the original polycyclic or multi-ring compound. This remaining alkylated single-ring aromatic compound will readily undergo transalkylation with other single-ring aromatic compounds like benzene or toluene to produce xylenes. Conditions employed in the transalkylation zone normally include a temperature of from about 200° to about 540° C. The transalkylation zone is operated at moderately elevated pressures broadly ranging from about 100 kPa to about 6 MPa absolute. The transalkylation reaction can be effected over a wide range of space velocities. Weighted hourly space velocity (WHSV) is in the range of from about 0.1 to about 20 hr −1 .
The transalkylation effluent is separated into a light recycle stream, a mixed C 8 aromatics product and a heavy recycle stream. The mixed C 8 aromatics product can be sent for recovery of para-xylene and other valuable isomers. The light recycle stream may be diverted to other uses such as to benzene and toluene recovery, but alternatively is recycled partially to the transalkylation zone. The heavy recycle stream contains substantially all of the C 9 and heavier aromatics and may be partially or totally recycled to the transalkylation reaction zone.
Several types of transalkylation catalysts that may be used in the present invention are based on a solid-acid material combined with a metal component. Suitable solid-acid materials include all forms and types of mordenite, mazzite (omega zeolite), beta zeolite, ZSM-11, ZSM-12, ZSM-22, ZSM-23, MFI type zeolite, NES type zeolite, EU-1, MAPO-36, MAPSO-31, SAPO-5, SAPO-11, SAPO-41, and silica-alumina or ion exchanged versions of such solid-acids. For example, in U.S. Pat. No. 3,849,340 a catalytic composite is described comprising a mordenite component having a SiO 2 /Al 2 O 3 mole ratio of at least 40:1 prepared by acid extracting Al 2 O 3 from mordenite prepared with an initial SiO 2 /Al 2 O 3 mole ratio of about 12:1 to about 30:1 and a metal component selected from copper, silver and zirconium. Refractory inorganic oxides, combined with the above-mentioned and other known catalytic materials, have been found useful in transalkylation operations. For instance, silica-alumina is described in U.S. Pat. No. 5,763,720. Crystalline aluminosilicates have also been employed in the art as transalkylation catalysts. ZSM-12 is more particularly described in U.S. Pat. No. 3,832,449. Zeolite beta is more particularly described in Re. 28,341 (of original U.S. Pat. No. 3,308,069). A favored form of zeolite beta is described in U.S. Pat. No. 5,723,710, which is incorporated herein by reference. The preparation of MFI topology zeolite is also well known in the art. In one method, the zeolite is prepared by crystallizing a mixture containing an alumina source, a silica source, an alkali metal source, water and an alkyl ammonium compound or its precursor. Further descriptions are in U.S. Pat. No. 4,159,282, U.S. Pat. No. 4,163,018, and U.S. Pat. No. 4,278,565.
Other suitable solid-acid materials include mazzite, ZSM-11, ZSM-22, ZSM-23, NES type zeolite, EU-1, MAPO-36, MAPSO-31, SAPO-5, SAPO-11, SAPO-41. Preferred mazzite zeolites include Zeolite Omega. The synthesis of the Zeolite Omega is described in U.S. Pat. No. 4,241,036. ZSM intermediate pore size zeolites useful in this invention include ZSM-5 (U.S. Pat. No. 3,702,886); ZSM-11 (U.S. Pat. No. 3,709,979); ZSM-12 (U.S. Pat. No. 3,832,449); ZSM-22 (U.S. Pat. No. 4,556,477); ZSM-23 (U.S. Pat. No. 4,076,842). European Patent EP 378,916 describes NES type zeolite and a method for preparing NU-87. The EUO structural-type EU-1 zeolite is described in U.S. Pat. No. 4,537,754. MAPO-36 is described in U.S. Pat. No. 4,567,029. MAPSO-31 is described in U.S. Pat. No. 5,296,208 and typical SAPO compositions are described in U.S. Pat. No. 4,440,871 including SAPO-5, SAPO-11, SAPO-41.
A refractory binder or matrix is optionally utilized to facilitate fabrication of the catalyst, provide strength and reduce fabrication costs. The binder should be uniform in composition and relatively refractory to the conditions used in the process. Suitable binders include inorganic oxides such as one or more of alumina, magnesia, zirconia, chromia, titania, boria, thoria, phosphate, zinc oxide and silica. Alumina is a preferred binder.
The catalyst also contains an essential metal component. One preferred metal component is a Group VIII (IUPAC8–10) metal, preferably a platinum-group metal. Alternatively a preferred metal component is rhenium. Of the preferred platinum group, i.e., platinum, palladium, rhodium, ruthenium, osmium and iridium, platinum is especially preferred. This component may exist within the final catalytic composite as a compound such as an oxide, sulfide, halide, or oxyhalide, in chemical combination with one or more of the other ingredients of the composite, or, preferably, as an elemental metal. This component may be present in the final catalyst composite in any amount which is catalytically effective, generally comprising about 0.01 to about 2 wt-% of the final catalyst calculated on an elemental basis. The platinum-group metal component may be incorporated into the catalyst in any suitable manner such as coprecipitation or cogellation with the carrier material, ion exchange or impregnation. Impregnation using water-soluble compounds of the metal is preferred. Typical platinum-group compounds which may be employed are chloroplatinic acid, ammonium chloroplatinate, bromoplatinic acid, platinum dichloride, platinum tetrachloride hydrate, tetraamine platinum chloride, tetraamine platinum nitrate, platinum dichlorocarbonyl dichloride, dinitrodiaminoplatinum, palladium chloride, palladium chloride dihydrate, palladium nitrate, etc. Chloroplatinic acid is preferred as a source of the especially preferred platinum component.
Moreover, when the preferred metal component is rhenium, typical rhenium compounds which may be employed include ammonium perrhenate, sodium perrhenate, potassium perrhenate, potassium rhenium oxychloride, potassium hexachlororhenate (IV), rhenium chloride, rhenium heptoxide, and the like compounds. The utilization of an aqueous solution of ammonium perrhenate is highly preferred in the impregnation of the rhenium component. Rhenium may also be used in conjunction with a platinum-group metal. This component may be present in the final catalyst composite in any amount which is catalytically effective, generally comprising about 0.01 to about 2 wt-% of the final catalyst calculated on an elemental basis.
The catalyst may contain additional modifier metal components. Preferred metal components of the catalyst include, for example, tin, germanium, lead, indium, and mixtures thereof. Catalytically effective amounts of such metal modifiers may be incorporated into the catalyst by any means known in the art. A preferred amount is a range of about 0.01 to about 2.0 wt-% on an elemental basis. In summary, the preferred metal components are platinum, palladium, nickel, tin, lead, iridium, germanium, rhenium, or a combination thereof; with platinum-tin or rhenium especially preferred.
EXAMPLES
The following examples are presented only to illustrate certain specific embodiments of the invention, and should not be construed to limit the scope of the invention as set forth in the claims. There are many possible other variations, as those of ordinary skill in the art will recognize, within the scope of the invention.
Example One
Samples of catalysts comprising mordenite were prepared for comparative pilot-plant testing by the forming process called extrusion. Typically, 2500 g of a powder blend of 25 wt-% alumina (commercially available under the trade names Catapal™ B and/or Versal™ 250) and 75 wt-% mordenite (commercially available under the trade name ZeolySt™ CBV-21A) was added to a mixer. A solution was prepared using 10 g nitric acid (67.5 wt-% HNO 3 ) with 220 g deionized water and the solution was stirred. The solution was added to the powder blend in the mixer, and mulled to make dough suitable for extrusion. The dough was extruded through a die plate to form cylindrically shaped (0.16 cm diameter) extrudate particles. The extrudate particles were calcined at about 565° C. with 15 wt-% steam for 2 hours.
Three different catalysts were finished using the extrudate particles and an evaporative impregnation with rhenium metal by using an aqueous solution of ammonium perrhenate (NH 4 ReO 4 ). The impregnated base was calcined in air at 540° C. for 2 hours. Catalyst A was finished at 0.7 wt-% rhenium. Catalyst B was finished at 0.15 wt-% rhenium. Catalyst C was finished at 0.4 wt-% rhenium.
A fourth catalyst was prepared on an extrudate particle similar to that used above, but an additional ingredient of MFI zeolite (commercially available as ZSM-5 under the trade name Zeolyst CBV 8014) was used to make a powder blend of 40 wt-% mordenite, 15 wt-% MFI, and 45 wt-% alumina. The extrudate particle, prepared as above, was finished with 0.05 wt-% platinum using chloroplatinic acid and 0.5 wt-% tin using tin chloride. This final catalyst was labeled Catalyst D.
Example Two
Catalysts A, B, C, and D were tested for aromatics transalkylation ability in a pilot plant using a heavy aromatics feed blend to demonstrate effectiveness of indane and naphthalene conversion and selectivity to xylenes. Table 1 provides the feed composition where 5.5 wt-% of the feed contains the coke precursors of indane, naphthalene species, and C 11 + aromatics. The test consisted of loading a vertical reactor with catalyst and contacting the feed at 2860 kPa abs (400 psig) under a space velocity (WHSV) of 2 hr −1 and hydrogen to hydrocarbon ratio (H 2 /HC) of 4. Before contacting the catalyst with the feed, the catalyst was reduced using hydrogen at 500° C. Various feed conversion levels were tested by adjusting reactor block temperatures and the results are shown in Tables 2 and 3 for high and moderate conversion of C 9 + material respectively.
The data showed extremely high conversion of coke precursors, which are also called poly-nuclear aromatic species, and these high conversions agree with the drop in the 99.5 wt-% ending-boiling-point across the reactor. The data also showed selective saturation of one of the rings in a polycyclic aromatic based on the showing of selectivity towards benzene and alkybenzenes instead of towards equivalent carbon number paraffinic species. Accordingly, a feed with over 5 wt-% coke precursors, defined as C 11 + aromatics plus polycyclic aromatics such as indane and naphthalene species, can be processed successfully in a transalkylation process for xylenes. Such a heavier feed stream permits easier fractionation specifications on distillation equipment used in front of the process, and permits a greater amount of heavy aromatics to be tolerated over the catalyst used in the invention.
TABLE 1
Feed Composition
Feed Stream Component
Amount (wt-%)
Xylenes
0.1
Tri-methyl-benzene (TMBz)
45.5
Methyl-ethyl-benzene (MEBz)
35.0
Propyl-benzene (prop-Bz)
3.3
C10 Aromatics
10.6
Indane
0.5
Naphthalene
0.6
Methylnaphthalene
0.8
Ethylnaphthalene
0.1
Dimethylnaphthalene
0.6
Trimethylnaphthalene
0.3
C11+
2.6
Total Components
100
ASTM D-2887 simulated GC method:
333° C.
99.5 wt-% ending boiling point
TABLE 2
High C 9 + Conversion
Catalyst
A
B
C
D
A 9 + Conversion
63.0
60.2
58.2
57.2
Reactor Temp. ° C.
389
420
394
396
Conversion (wt-%)
TMBz
47.0
45.2
41.2
37.0
MEBz
88.6
87.4
87.0
89.7
Prop-BZ
99.3
99.5
99.5
99.6
C10A
36.1
30.4
23.0
23.4
Indane
90.2
90.4
90.0
69.7
Naphthalene
97.3
88.7
94.1
89.9
Methylnaphthalene
89.5
50.6
74.4
78.4
Ethylnaphthalene
84.3
53.8
70.4
74.5
Dimethylnaphthalene
75.9
0.0
41.9
61.3
Trimethylnaphthalene
73.0
20.7
49.2
69.2
C11+
64.7
39.2
47.8
40.6
99.5 End Point (° C.)
273.5
297.8
309.4
290.2
Selectivity (wt-%)
C1
10.7
5.7
7.0
0.1
C2
12.0
17.9
13.8
19.7
C3
7.8
9.8
6.6
7.2
C4
4.0
2.2
2.6
3.3
C5
1.1
0.6
0.7
1.0
C6
0.8
0.2
0.4
0.5
C7
0.2
0.0
0.1
0.1
C8
0.0
0.0
0.0
0.0
Benzene
3.2
3.5
3.2
3.7
Toluene
19.8
20.4
20.3
23.4
Ethylbenzene
1.2
1.4
1.5
1.1
Xylenes
39.1
38.3
43.7
39.8
Total
100.0
100.0
100.0
100.0
TABLE 3
Moderate C 9 + Conversion
Catalyst
A
B
C
D
A 9 + Conversion
49.8
42.9
47.13935
39.5
Reactor Temp. ° C.
363
377
374
369
Conversion (wt-%)
TMBz
36.3
30.8
33.4
21.7
MEBz
74.4
67.8
74.1
70.0
Prop-BZ
97.3
98.0
98.2
97.5
C10A
4.7
0.0
0.0
0.0
Indane
83.2
80.0
82.7
51.5
Naphthalene
95.3
91.1
94.4
81.8
Methylnaphthalene
90.7
71.3
80.7
69.3
Ethylnaphthalene
73.1
32.5
59.3
55.5
Dimethylnaphalene
75.7
27.0
51.3
50.6
Trimethylnaphalene
69.1
33.7
52.5
60.0
C11+
41.3
6.2
23.5
5.7
99.5 End Point (° C.)
278.1
294.4
292.5
319.4
Selectivity (wt-%)
C1
8.9
1.1
3.8
0.1
C2
13.0
14.3
13.4
16.6
C3
6.9
6.7
6.2
5.7
C4
4.3
2.2
2.7
2.3
C5
1.7
0.6
0.8
0.8
C6
1.6
0.3
0.7
0.5
C7
0.9
0.1
0.3
0.2
C8
0.3
0.0
0.0
0.0
Benzene
2.6
3.4
3.0
4.1
Toluene
17.9
21.7
20.5
28.0
EthylBenzene
2.4
3.6
2.9
3.0
Xylenes
39.5
43.0
44.8
37.9
Total
100.0
100.0
100.0
100.0
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A catalyst, and a process for using the catalyst, that effectively converts and transalkylates indane and C 10 and heavier polycyclic aromatics into C 8 aromatics is herein disclosed. The catalyst comprises a solid-acid support such as mordenite plus a metal component such as rhenium. The catalyst provides excellent conversion of such heavy aromatic species as naphthalene, which is also observed by a decrease in the ending-boiling-point of a hydrocarbon stream passed over the catalyst. The same catalyst is also effective for transalkylation of lighter aromatics, thus yielding a valuable xylenes product stream out of the process.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part of application Ser. No. 14/599,284, filed on Jan. 16, 2015.
FIELD OF THE DISCLOSURE
[0002] The present invention relates to a bendable straight knitting needle, specifically a straight knitting needle made from any material. Accordingly, a method to realize this invention is also provided.
BACKGROUND
[0003] Standard straight knitting needles generally range from 10 to 16 inches, being a narrow stiff shaft that tapers at one end and has a knob at the other end to prevent stitches from slipping off. Straight knitting needles are known to be made of plastic, metal, casein, or wood. These needles are used in knitting to pull loops of string through one another. Needles come in the thickness from 0.75 mm to 25 mm and are commonly marked with U.S. or U.K. sizes that correspond to the mm thickness. The long narrow stiff shaft is not bendable and can therefore result in pain, tiredness and numbness from repeated motion of wrists, hands, and fingers during the formation of loops in the knitting position that must accommodate to the long straight stiff knitting shaft as well as difficulty maneuvering comfortably while knitting in confined spaces and around surrounding obstacles.
SUMMARY
[0004] In accordance with the invention, the advantage of the bendable connection between knitting needles is the ability to bend the needle during formation of loops in a more comfortable manner for arm, wrist, hand, and finger movements as well as more ease of knitting movement in a confined work space.
[0005] The present invention relates to a bendable straight knitting needle consisting of two relatively stiff shanks. Each shank has two ends. One embodiment has a resilient member.
[0006] The resilient member has two ends and can be made of any flexible material such as polyurethane. A first shank has one pointed at one end and joint back end with one end of the resilient member in positioned within the joint end of said first shank. A second shank has one end with a knob and a joint end that attaches to the second end of said resilient member. The resilient member and the joint ends of the shanks form a joint that allows the knitting needle to bend during use.
[0007] In another embodiment, the first shank has one pointed at one end and one back end with internal screw threads in positioned within the back end. The second shank has one end with a knob and back end with internal screw threads in position within the back end, wherein said shanks are connected with each other by the back ends with a bendable vinyl hollow connecting tube containing a metal coil with external metal screw attached at each end of the coil comprising a joint. The joint between the stiff shanks and the bendable hollow connecting tube consisting of an external metal screw attached to the metal coil at each end and protruding out of the tube that contains the metal coil to be inserted into the back end of the shank wherein internal screw threads are positioned.
DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 illustrates a perspective schematic view of the present invention. The two relatively stiff ends of the needle are denoted by 1 , 2 whereas the bendable connecting tube between the two shanks is denoted by 3 . The shank is made from plastic whereas the bendable connecting tube is made from vinyl. See FIG. 1 .
[0009] FIG. 2 illustrates one end of the needle or shank ( 1 ) which is pointed at one end and the other end forms a joint with the bendable connecting tube and one end of the knobbed shank ( 2 ) which has a knob at one end and the other end forms a joint with the bendable connecting tube. See FIG. 2 .
[0010] FIG. 3 illustrates the junction between the shank and the bendable connecting tube where the external screw ( 4 ) and metal coil ( 5 ) are connected, and coil contained in the vinyl tubing ( 6 ) are shown in detail. See FIG. 3
[0011] FIG. 4 illustrates positioning of the drilled internal screw threads ( 4 ) in the back end of each shank and the design of which shows an inward curvature that will insure a strong and even one-level closure when the connecting vinyl tube is attached. See FIG. 4 .
[0012] FIG. 5 illustrates the design of the bendable vinyl tubing that will connect the two stiff shafts at their back ends. A portion of the end of the vinyl tubing that contains the metal coil will also be inserted into the back end of shaft. The design shows two slanted edges at each end of bendable tube that will meet the opposing slanted edge of the shafts during attachment. This will insure a strong and even one-level closure when connecting. See FIG. 5 .
[0013] FIG. 6 illustrates the metal coil that will be contained in the vinyl tubing with the external screws 4 attached at each end which will protrude outward from the bendable vinyl tube. See FIG. 6 . Various modifications and alterations of this invention will become apparent to those skilled in the art without departing from the scope and spirit of this invention and it should be understood that this invention is not unduly limited to the illustrative embodiment set forth herein.
[0014] FIG. 7 illustrates a perspective view of the present invention. The two components or shanks of the needle 10 are denoted by 20 , 30 whereas the bendable connecting tube or resilient member between the two shanks is denoted by 40 .
[0015] FIG. 8 illustrates a perspective view of one shank 20 which is pointed at one end 22 and the other end 24 forms a joint with the resilient member 40 and with a second shank 30 .
[0016] FIG. 9 illustrates a perspective view of a second shank 30 which is has a knob at one end 34 and a joint end 32 forming a joint with the resilient member and with the first shank 20 .
[0017] FIG. 10 illustrates a perspective view of the resilient member 40 , which connects to shanks 20 , 30 .
[0018] FIG. 11 illustrates a perspective view of shanks 20 , 30 connected to resilient member 40 .
[0019] FIG. 12 illustrates a cross-section view of the invention of FIG. 7 .
DETAILED DESCRIPTION OF EMBODIMENTS
[0020] The detailed description set forth below in connection with the appended drawings is intended to provide example embodiments of the present invention and is not intended to represent the only forms in which the invention may be constructed or utilized. The description sets forth the function and the sequences of steps for constructing and operating the invention. However, it is to be understood that the same or equivalent functions and sequences may be accomplished by different embodiments that are also intended to be encompassed within the spirit and the scope of the invention.
[0021] The bendable straight knitting needle with ergonomic benefit consists of two stiff shanks 1 , 2 pointed at one end 1 and one knob end 2 and suitably machined for attachment at the other ends.
[0022] In one embodiment, the product consists of two stiff shanks 1 , 2 , one suitably pointed at one end for knitting and one with a knob at the base for holding knitted stitches, connected from the other ends using a bendable hollow vinyl tube 6 containing a metal coil 5 with attached metal external screws 4 at each end of coil 5 . The joint between the stiff shank and the bendable connecting tube consists of internal screw threads 4 positioned inside the back end of each shank and a metal external screw 4 connected to the metal coil that is contained in the hollow vinyl tubing 6 . The bendable tubing will be the same thickness as the shank and extremely smooth enabling the individual stitches to slide over connection and tubing without impairment, and bendable for ergonomic benefit.
[0023] Another aspect of the invention is the method to realize this invention. The two stiff shanks 1 , 2 of the knitting needle are made from plastic, metal, casein, or wood. The joint between the stiff shanks and the bendable tube 3 is made by inserting the external screw 4 which is attached to the metal coil 5 that is contained in the bendable vinyl tube 6 , into the stiff shank where internal screw threads 4 are positioned and screwed and glued together.
[0024] The present invention relates an invention where, the stiff shanks 1 , 2 are made of plastic whereas the bendable connecting tube 3 is made of bendable hollow vinyl, metal coiling 5 , and attached external metal screw 4 at each end of coil. In the back ends of shaft 1 , 2 , internal screw threads 4 are positioned and drilled.
[0025] In another embodiment of the invention, a method for the manufacture of the bendable knitting needle is provided. The shanks are manufactured by conventional manufacturing processes. The addition of the bendable material is the substance of the invention.
[0026] The bendable material used is in the form of a vinyl hollow tubing 6 that matches the thickness of the stiff shanks 1 , 2 , metal coil 5 , with attached metal external screws 4 . This bendable tube 3 is connected to the stiff shanks using a protruding external screw 4 at each end of bendable tube to be inserted and screwed into the threads of the internal screw threads 4 which are positioned in the back ends of the stiff shanks.
[0027] The joint itself is made by the vinyl tubing 6 and metal parts with attached external screw 4 , threaded to the internal screw threads within the plastic shanks 1 , 2 . The tolerances are such that they meet the requirements of the product and the joint.
[0028] The screw 4 is manufactured and attached to the metal coil 5 , which is contained in the clear bendable vinyl tube 6 .
[0029] The stiff shanks 1 , 2 are made with the back end (the end that is not pointed or knobbed) finished to a diameter suited for development of a drilled internal screw. The external metal screw 4 that is attached to the metal coil 5 , which is contained in the bendable vinyl tube 6 matches the thickness of the shank and is then inserted into the back ends of the stiff shanks.
[0030] The threaded portion of the external screw 4 is attached directly into the internal screw threads which are positioned within the shank. Adhesive may be applied to the threaded portions to ensure that it is a permanent tight lock.
[0031] The above method results in a bendable straight knitting needle, which has the ability to bend in a manner that would be of ergonomic benefit in mobility and can accommodate more readily to a confined workspace.
[0032] In another embodiment, the invention relates to a bendable straight knitting needle 10 with ergonomic benefit, specifically, a long, thin, pointed rod from any material with a bendable addition which enables more natural and less labored movement of the arms, hands, wrists, and fingers during stitch formation compared to other knitting needles found in the prior art. The knitting needles are also advantageous when the surrounding work space is limited as the needles can bend. The bendable straight knitting needle with ergonomic benefit consists of two stiff shanks ( 20 , 30 ) pointed at one end ( 22 ) and one knob end ( 34 ) and suitably machined for attachment at the other ends ( 24 , 32 ).
[0033] FIG. 7 shows one embodiment with two shanks 20 , 30 of the needle 10 . A resilient member 40 is inserted in between the two shanks 20 , 30 . The two shanks 20 , 30 , of the knitting needle 10 may be made from plastic, metal, casein, or wood.
[0034] FIG. 8 illustrates one shank 20 which has a pointed end 22 and has a joint end 24 . Pointed end 22 is used to facilitate weaving together string or yarn while knitting. Joint end 24 forms a joint with the resilient member 40 and the joint end 32 of second shank 30 .
[0035] FIG. 9 illustrates a second shank 30 which is has a knob end 34 . The knob end 34 is used to prevent the string from slipping off the needle 10 when knitting. Second shank 30 has a joint end 33 that forms a forms a joint with the resilient member 40 and the joint end 24 of shank 20 .
[0036] FIG. 10 illustrates the resilient member 40 used to form the joint between shank 20 and shank 30 . Resilient member 40 may take the embodiment of a flexible tube or other shapes. Resilient member 40 has two ends 42 and 44 which connect to the two joint ends 24 , 32 of the shanks 20 , 30 , respectively.
[0037] The bendable material used to form the resilient member 40 , may be shaped as a tube that matches the thickness of the shanks 20 , 30 . The resilient member 40 may be comprised of any flexible material known in the art including, but not limited to a spring, coil, magnet, rubber inserts, or cables. Materials in the preferred embodiment include thermoplastic elastomers, TPU (thermoplastic urethanes), and thermoset polyurethanes. The degree of flexibility of the joint between the shank 20 , 30 will vary depending on the flexibility of the material used to make the resilient member 40 .
[0038] FIG. 11 shows how shanks 20 , 30 and the resilient member 40 are used to assemble the bendable knitting needle 10 . The resilient member 40 is positioned between shanks 20 , 30 and the joint ends of those shanks 24 , 32 are inserted into ends 42 and 44 of the resilient member, respectively.
[0039] FIG. 12 illustrates a cross section of FIG. 7 . As shown in FIG. 12 , there is a spaced relationship or gap between the joint ends 24 , 32 of the shanks 20 , 30 when the joint ends 24 , 32 are inserted into resilient member 40 . Depending on the length of the resilient member 40 , the gap will also be of varying lengths. Furthermore, depending on the length of gap the flexibility of needle 10 will change. For example, a longer gap will mean that needle 10 is more flexible. Thus, in addition to changing the flexibility of needle 10 by changing the material of resilient member 40 , the flexibility of needle 10 may be changed by varying the length of gap.
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A bendable straight knitting needle consisting of at least three parts that provides ergonomic benefit by enabling bending of the needle during stitch/loop creation by the knitter typically done with two knitting needles, one in each hand. The addition of the bendable portion to the standard conventional straight knitting needle would allow flexible knitting motion with enhanced comfort and better ease of knitting in a tight place.
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[0001] The invention relates to an ammunition drum for a firearm, having at least two projectile channels arranged around a longitudinal drum axis. The invention further relates to a firearm, having at least one barrel and at least one ammunition drum.
BACKGROUND OF THE INVENTION
[0002] Ammunition drums of this type are used for feeding projectiles to the barrel of a firearm. They have several projectile channels, which are arranged at even mutual angular distances around the longitudinal axis of the drum. Generally, but not absolutely, the longitudinal drum axis, the longitudinal channel axes and the core axis of the barrel are aligned in parallel. The ammunition drum can be rotated in steps around the longitudinal drum axis; in the course of its rotation it makes stops for a limited pause at defined angular positions between successive steps. In this way the projectile channels come into different positions in turns, in particular into a receiving position, in which they take up a projectile, and into a feed position, in which they deliver the projectile. In this case the projectile channel is located at the inlet side in front of the barrel, i.e. the projectile channel and the barrel are arranged coaxially in respect to each other. Depending on the firearm with which they are used, the ammunition drums can comprise different numbers of projectile channels, and the number of the steps and pauses are different. In theory, the feeding of ammunition to a barrel is possible by means of an ammunition drum with only a single projectile channel which, in the course of a full rotation of the ammunition drum, is only brought into two positions. However, generally ammunition drums have several, often three to six, projectile channels. The number of the projectile channels corresponds to the number of positions of the ammunition drum in which their step-by-step rotation is interrupted by a pause.
[0003] Ammunition drums of the customary type are very well suited for feeding comparatively small-caliber ammunition to comparatively light guns. However, in connection with the use of ammunition drums for heavier guns numerous problems arise in feeding ammunition, both during the employment of the firearm, as well as in the manufacture and mounting of the ammunition drum.
[0004] When used in firearms, it is necessary to accelerate and decelerate the mass during each step in the course of the rotation of the ammunition drum. This mass is composed of the mass of the projectiles to be conveyed and of the mass of the ammunition drum itself. Both the mass of the projectiles and the mass of the drum increase with increasing caliber of the projectiles. Although the mass to be moved can be kept relatively low, even with comparatively large calibers, if ammunition drums with few projectiles are used, it is difficult in this case to achieve the high rate of fire considered necessary for modern guns.
[0005] When employing the weapons, essentially two disadvantages arise because of large masses to be moved. For one, the position of the gun and therefore the direction of the barrel can be changed on account of reactive forces exerted on the gun during each acceleration and deceleration of the ammunition drum; this has the result that the dispersion pattern changes, or the weapons effect is reduced. Furthermore, the large forces cause great wear on the moved parts, which has a negative effect on the firearm and results in a reduction of its service life.
[0006] But the manufacture of ammunition drums having a large mass also has disadvantages. For one, the weight of the ammunition drum becomes so great that it can no longer be moved and mounted without aids. Furthermore, it is necessary to use materials which are highly wear-resistant, since this material must be selected with an eye to the greatest possibly arising wear, although this wear occurs on only a few locations. Highly wear-resistant materials are in general specifically heavy and in any event comparatively expensive, not only in obtaining them, but in most cases also in processing them, since they are not easily workable; in this connection it is particularly disadvantageous that errors in processing occurring during the end phase of manufacturing cause the entire ammunition drum to become waste, so that it is necessary to accept a comparatively large loss of material and processing time.
[0007] To reduce the mentioned disadvantages, an attempt was made to reduce the mass of the ammunition drums by suitable shaping, in that cutouts were made in the areas which are not, or only slightly stressed. However, in this case the same amount of initial material is required, and processing is not simpler, but more elaborate. Moreover, there are limits to the application of cutouts, since the shape, and in particular the wall thickness of the remaining mass, must be such that it is still possible to work in cooling conduits for a coolant. It is alternatively possible to provide an exclusive cooling by means of the ambient air, but for this a shape with cooling ribs is required, which again makes processing more elaborate.
[0008] In summary it can be stated that no ammunition drums are known which would be suitable for feeding large-caliber projectiles to barrels.
OBJECT AND SUMMARY OF THE INVENTION
[0009] It is the object of the invention to
[0010] produce an ammunition drum of the type mentioned at the outset, by means of which the disadvantages of the prior art are avoided in its use, as well as in its manufacture, and
[0011] to propose a firearm with an ammunition drum also suitable for large-caliber projectiles.
[0012] This object is attained in the following ways:
[0013] in connection with the ammunition drum of the type mentioned at the outset by the features of the characterizing portion of claim 1, and
[0014] in connection with the firearm by means of the characteristics of claim 17.
[0015] Preferred further developments and details of the ammunition drum are defined in claims 2 to 16 depending from claim 1.
[0016] The novel ammunition drum is built in a modular fashion and therefore differs from conventional ammunition drums in that it is produced from at least two, but generally three or more drum segments. The mass of the individual drum elements is reduced by this, so that their handling is made easier. A processing error in an end phase has no grave consequences, since only the affected drum segment needs to be replaced, and not the entire ammunition drum. In case of an inspection of the firearm it is moreover possible to only replace damaged drum segments, so that the total service life of the ammunition drum is increased.
[0017] To make the precise fitting of adjoining drum segments easier, it is advantageous to provide the touching separating faces of these drum segments with complementary fitting elements.
[0018] The ammunition drum can be designed in such a way that the drum segments are longitudinal segments, wherein the separation between adjoining drum segments essentially extends in the direction of the longitudinal drum axis. With a configuration of this type it is possible to embody the drum segments sector-like and preferably uniform. In general, each drum segment contains a projectile channel, but it is also possible to arrange several projectile channels in each longitudinal segment, or to arrange a spacing element without a projectile channel between two longitudinal segments with projectile channels. One projectile channel can also be bordered partially by one and partially by a second, adjoining longitudinal element. The projectile channels can have an insert in the form of a highly heat-resistant and low-abrasion insert; this allows the manufacture of the portions of the longitudinal segment surrounding the insert from a material which can be stressed less and is comparatively cost-effective.
[0019] An ammunition drum, whose drum segments are transverse segments, has proven itself to be particularly advantageous, wherein the separation between adjoining transverse segments essentially extends transversely in respect to the longitudinal drum axis.
[0020] In this case the ammunition drum is generally designed in such a way that it has a center segment consisting mainly of projectile channels. The center segment can be a single element and comprise the totality of the projectile channels, or it can consist of several, preferably uniform segment units. In general, every segment unit comprises one, or possibly even more than one projectile channel. But the ammunition drum can also be embodied in such a way that the center segment has segment units with and without a projectile channel in alternation.
[0021] Center segments with a plurality of segment units are particularly advantageous from the viewpoint of cooling. The segment units can be embodied to be tube-like, so that special coolant channels can possibly be omitted.
[0022] Furthermore, an ammunition drum made of transverse segments has a transverse segment embodied either as a front segment or as a rear segment; viewed in the firing direction of the firearm, the front segment is located at the front, and the rear segment at the rear of the center segment. The ammunition drum preferably is comprised of a front segment as well as of a rear segment.
[0023] With very large ammunition drums it is possible not only for the center segment to be transversely divided, but also the front and/or the rear segment. Very long transverse segments can be again divided into several transverse segments.
[0024] The course of the diameters of the projectile channels over the length of the ammunition drum is a function of the shape of the cartridge to be fired. For cylindrical cartridges, the projectile channels can have a constant diameter over the axial length of the ammunition drum and can possibly be used for returning the empty cartridges after firing. For non-cylindrical cartridges the projectile channels can have a rear area of larger diameter as a shell seating, or cartridge seating, and a front area of lesser diameter; with such an arrangement the empty shells are ejected toward the rear.
[0025] The projectile channels are the parts of the ammunition drum which are the most thermally and mechanically stressed; in a construction with a center segment, a front segment and/or a rear segment, it is possible to select a high-quality, in particular greatly heat-resistant material, for the center segment, while the front segment and the rear segment can be produced from less resistant, but more cost-effective, lighter and easier to work materials.
[0026] In connection with this it has been shown to be advantageous to embody the ammunition drum in such a way that the projectile channels run over the entire drum length and therefore extend from the center segment in, or through, the front segment, and in, or through, the rear segment.
[0027] To increase the useful life of the ammunition drum and to assure dependable functioning it is necessary to keep the temperature of the ammunition drum, and of the projectile channels in particular, within a limited temperature range, and to this end to cool them sufficiently. This is particularly important in connection with weapons with a high rate of fire and with comparatively light drums, such as are preferred for dynamic reasons. Measures for cooling must assure that cooling is not only performed at the moment of firing, but also thereafter; it is intended by this to prevent the spontaneous ignition, in particular the spontaneous ignition of the projectiles remaining after the last shot in the projectile channel, which is also known as the cook-off effect. Monitoring of the cooling effect can be performed in a simple manner if cooling takes place with the aid of a coolant circulating through coolant channels. In this case it is sufficient to provide a flow-through monitor which, with insufficient coolant flow, generates a warning signal. Cooling devices of this type are suitable for all ambient temperatures, in particular also for very high ambient temperatures.
[0028] The following should be observed when selecting a suitable coolant: the coolant must not evaporate a high temperatures or chemically change in disadvantageous ways; the coolant must not freeze at low temperatures or have too great a viscosity; in no way must the coolant be corrosive or abrasive. A suitable coolant is water, for example, which has been provided with a suitable additive. Glycol can be used as additive, for example, which provides protection against cold and corrosion.
[0029] In place of cooling by means of a particular coolant, for example water with an additive, cooling can also take place with the aid of the ambient air, provided the ammunition drum has a suitable shape. Suitable shaping, for example by cooling ribs, can be provided here in place of coolant channels.
[0030] Generally those areas of ammunition drums which are divided into transverse segments and have a front segment, a center segment and a rear segment extending into the interior of the front segments, or of the rear segment, must be cooled. This is all the more important, the greater the axial length of the areas of the projectile channels arranged in the interior of the front segment, or the rear segment, is. Coolant channels can be provided for this purpose in the front segments and/or the rear segments. To produce the cooling channels as simply as possible, it is advantageous to cut one or several cutouts into the exterior surface of the segment units of the center segment, namely in that area which comes to lie in the front segment or the rear segment; together with the wall of the front segment, or the rear segment which, in the mounted state is oppositely located, the wall of this cutout then delimits a cooling channel which is optimal, i.e. closest, to the location of the heat generation. Outside of the front segment, or the rear segment, cooling can then take place without special coolants, merely with the aid of the ambient air. A sufficient cooling effect is obtained with such a construction, along with a simple shaping and low coolant consumption.
[0031] The individual drum segments can be connected in various ways with each other. The connection can take place, for example, without connecting elements, merely by an interlocking or frictional connection.
[0032] The movement of the ammunition drums takes place from the outside, for example, by means of drive rollers. The feeding of cartridges can take place by means of a central drive member arranged in a central opening or cutout of the ammunition drum.
[0033] A connection by means of integral connecting elements can be mentioned as an example for an interlocking connection of drum segments, for example a connection by means of complementary grooves and projections; by means of this it is possible in particular to fasten drum segments, which are embodied as longitudinal segments, to each other, whose separating planes extend in the direction of the longitudinal drum axis, preferably diametrically.
[0034] A contracting connection can be mentioned as an example for a frictional connection of drum segments, by means of which a center segment, or segment units of a center segment, in particular can be fastened on a front segment or a rear segment.
[0035] However, the ammunition drum can also have additional connecting elements, for example screws, by means of which the drum segments are braced against each other; in this connection it can be essential to provide screw-locking devices in order to prevent the loosening of the screws because of the dynamic loads under use; in this way it is possible in particular to brace center segments, or units of center segments, between the front segment and the rear segment. In place of the mentioned connections of drum segments, it is also possible to provide other suitable connections. For example, the center segment can be connected by welding with the front segment and the rear segment; however, this may make a later processing, in particular of the projectile channels, necessary.
[0036] The novel ammunition drum is designed to be fastened on a firearm. For retrofitting existing firearms it is preferably designed in such a way that no changes are required for mounting and for the movement of the ammunition drum on the firearm.
[0037] Further advantages and details of the invention will be explained in what follows by means of exemplary embodiments and by reference to the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] [0038]FIG. 1 is a diagram of an exemplary embodiment of an ammunition drum in accordance with the invention;
[0039] [0039]FIG. 2 is a diagram of a front portion of the ammunition drum represented in FIG. 1,
[0040] [0040]FIG. 3 is a diagram of a longitudinal segment of a center section of the ammunition drum represented in FIG. 1, and
[0041] [0041]FIG. 4 is a diagram of a rear section of the ammunition drum represented in FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] It should be noted at the outset that the drawings are not to scale.
[0043] [0043]FIG. 1 shows an ammunition drum 110 with a longitudinal drum axis 112 . Transversely in respect to the longitudinal drum axis 112 , the ammunition drum 110 is divided into three drum segments 114 . 1 , 114 . 2 , 114 . 3 embodied as transverse segments, and furthermore has three connecting elements 120 in the form of screws. The first drum segment 114 . 1 , also called rear segment 114 . 1 , is represented in FIG. 2; the second drum segment 114 . 2 , also called center segment 114 . 2 , essentially consists of four identical segment units extending parallel in respect to the longitudinal drum axis 112 and is represented in FIG. 3; the third drum segment 114 . 3 , also called front element 114 . 3 , is represented in FIG. 4.
[0044] In general, the transverse segments touch at their separating faces, which extend transversely in respect to the longitudinal drum axis 112 . The separating faces of a transverse segment need not be continuous, i.e. several individual partial separating faces can be present on a transverse segment, which are separated from each other by cutouts. The separating faces can also have partial separating faces extending in the direction of the longitudinal drum axis, in particular for providing fitting elements, which make the precise joining of the transverse elements easier. Moreover, the separating faces can also be formed so they run together in the direction of the longitudinal drum axis, or have partial separating faces which run together, which also makes the precise assembly of the individual transverse segments easier.
[0045] In accordance with FIG. 2, the rear segment 114 . 1 is designed similar to a flange and has a centered bore 115 . 1 for receiving a shaft, not represented, by means of which the ammunition drum 110 can be put into rotation when it is fastened on a firearm, not represented. The rear segment 114 . 1 has four bores 115 . 2 , which are arranged at even mutual angular spacings of 90° and at equal distances from the centered bore 115 . 1 . The bores 115 . 2 are used for receiving the rear ends of the segment units 114 . 4 of the center segment 114 . 2 . Moreover, the rear segment 114 . 1 has four bores 115 . 3 for receiving the connecting elements 120 .
[0046] In accordance with FIG. 3, each one of the segment units 114 . 4 of the center segment 114 . 2 is designed in a tube shape and delimits a projectile channel 116 , having a longitudinal channel axis 118 . The segment units 114 . 4 can also be delimited otherwise than cylindrical, and the center segment 114 . 2 can also be embodied as a single part. The longitudinal channel axes 118 are oriented parallel with the longitudinal drum axis 112 . In accordance with FIG. 1, each segment unit 114 . 4 of the center segment 114 . 2 extends over the entire axial length of the ammunition drum 110 , i.e. the rear end of each segment unit 114 . 4 projects into the rear segment 114 . 1 , and the front end into the front segment 114 . 3 . The exterior diameter of the front portion of each segment unit 114 . 4 is less than the exterior diameter of its rear portion. A cutout 122 , preferably helical, which constitutes a first border of a coolant channel, extends over the external surface of the front portion of each segment unit 114 . 4 . A second border of the coolant channel is formed by the interior wall of a bore 115 . 4 of the front segment 114 . 3 . It is also possible for several coolant channels to be present in a front segment. The coolant channels are intended to receive a coolant, which circulates when the weapon is used. A strip at the front end of the front portion is of such a size that sealing problems of the circulating coolant are prevented.
[0047] The front segment 114 . 3 represented in FIG. 4 has a central bore 115 . 5 . In the assembled state of the ammunition drum 110 , the bore 115 . 5 is aligned with the central bore 115 . 1 of the rear segment 114 . 1 and is used for receiving the shaft, not represented, used for seating the ammunition drum 110 and for driving the ammunition feeding device. Furthermore, the front segment 114 . 3 has the already mentioned four bores 115 . 4 which, in the assembled state of the ammunition drum 110 , receive the front ends of the center segment 114 . 2 , or of the segment units 114 . 4 of the center segment 114 . 2 . The front segment 114 . 3 moreover has four flange-like protrusions 124 with bores 125 , in which the connecting elements 120 are received in the mounted state of the ammunition drum 110 . Furthermore, four connection places 132 are formed on the front segment 114 . 3 and are used for receiving drive rollers, by means of which the driving of the ammunition drum 110 takes place.
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An ammunition drum ( 110 ) and firearm with an ammunition drum ( 110 ). The ammunition drum designed for being mounted on a firearm has at least two projectile channels ( 118 ), which are arranged around a longitudinal drum axis ( 112 ). The ammunition drum ( 110 ) has at least two drum segments ( 114.1, 144.2, 114.3 ), which are connected with each other.
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BACKGROUND OF THE INVENTION
This invention relates to a selvage forming system of a shuttleless loom, more particularly to an improvement in a selvage forming system of the shuttleless loom of the type wherein rigid selvage structures are formed at both sides of a woven fabric by binding cut end portions of weft yarns with binding yarns.
It is well known that a shuttleless loom is equipped with a selvage forming system which forms selvage structures at the both sides of a fabric during weaving operation of the fabric. The selvage structure is necessary for preventing warp yarns to fray or separate from the both sides of the woven fabric. It is also well known that two binding yarns or threads are twisted together, putting the ends of picked weft yarns between the two binding yarns. In such a selvage forming system, two binding devices, in general, are installed adjacent the both sides of the array of the warp yarns and located opposite to each other. The two binding yarns are drawn from each binding device and guided to the one side of the array of the warp yarns. Then, the two binding yarns continue alternately their opening and closing actions generally at the same time respectively as the opening and closing actions of the array of the warp yarns. Simultaneous, the two binding yarns are twisted together at each pick of the weft yarn to the shed of the warp yarn, to put the ends of the picked weft yarn between the two binding yarns. As will be appreciated from the foregoing, the essential part of each binding device is composed of a rotatable mechanism.
The two binding devices are usually driven to rotate their rotatable mechanisms by a drive shaft for rotatably connecting them. Accordingly, the rotatable mechanisms of the two binding devices are rotated in the same direction with respect to the shuttleless loom. However, the mechanisms are rotated in opposite directions to each other with respect to each binding device itself. Hence, two binding yarns from one binding device are twisted in the direction opposite to that in the two binding yarns from the other binding device.
Now, when a fabric is woven with so-called "spun yarns," it is necessary to use the same spun yarns as the binding yarns for forming the selvage structures of the woven fabric. Because, if so-called "filament yarns" are used as the binding yarns for spun yarn fabric, shrinkages may occur at the selvage structures of the fabric, which are caused by the fact that the shrinking characteristics between the spun yarn and the filament yarn are considerably different.
In case of using a two-ply cotton yarn as each binding yarn, assuming that the weft yarn density is 31 yarns per cm, the two binding yarns are twisted 1550 times per meter of the woven fabric. With respect to the two-ply cotton yarn, about 1000 times twistings per meter are applied to it. Therefore, if the two binding yarns are twisted, during selvage formation, in the direction opposite to that of the twistings previously applied to the two-ply cotton yarn, the twistings previously applied to the two-ply cotton yarn may be almost cancelled. This considerably lowers the strength of the binding yarns for forming one of the two selvage structures of the fabric and therefore the binding yarns of the one selvage structure are liable to cut. Hence, the one selvage structure is also liable to easily break. In order to prevent such a selvage structure breaking, it will be considered to use specially prepared two-ply yarns which are previously twisted in the direction opposite to that in usual two-ply yarns, as the binding yarns for forming the one selvage structure. However, this causes the management of weaving to be troublesome. Furthermore, if such two kinds of binding yarns are used in error, the twistings of all the binding yarns will be cancelled.
SUMMARY OF THE INVENTION
It is the prime object of the present invention to provide an improved selvage forming device of a shuttleless loom, by which rigid selvage structures can be formed at both sides of a woven fabric.
Another object of the present invention is to provide an improved selvage forming device of a shuttleless loom, by which all the binding yarns for forming the selvage structures of a fabric are not liable to be easily cut.
A further object of the present invention is to provide an improved selvage forming device of a shuttleless loom, equipped with two binding devices for binding both ends of weft yarns with bindings yarns to form selvage structures at both sides of a fabric, the two binding devices being located to prevent the windings of all the binding yarns from being cancelled during weaving operation.
A still further object of the present invention is to provide an improved selvage forming device of a shuttleless loom, equipped with two binding devices for binding both ends of weft yarns with binding yarns to form selvage structures of a fabric, the two binding devices being located so that all the binding yarns from the two binding devices are twisting in the same direction during weaving operation.
Other objects, features and advantages of the improved selvage forming system according to the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings in which like reference numerals are assigned to like parts and elements.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic plan view of a shuttleless loom equipped with a selvage forming system in accordance with the present invention;
FIG. 2 is a schematic front view of a binding device forming part of the selvage forming system of FIG. 1;
FIG. 3 is a sectional side elevation of the selvage forming device of FIG. 1; and
FIG. 4 is a schematic side view of another selvage forming system also to which the principle of the present invention is applicable.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to FIG. 1 of the drawings, there is shown an example of a shuttleless loom 10, equipped with a preferred embodiment of a selvage forming system 12 in accordance with the present invention. The selvage forming system 12 is arranged to form first and second rigid selvage structures S 1 and S 2 at both sides of a fabric F, respectively. In this instance, the selvage forming system 12 comprises first and second binding devices 14 and 16 respectively for binding the cut end portions of weft yarns constituting the first selvage structure S 1 and the other cut end portions of the same constituting the second selvage structure S 2 . Each binding device is arranged to bind the corresponding end portions of weft yarns Y 1 with two binding yarns b 1 and b 2 , or b 1 ' and b 2 '. The first and second binding devices 14 and 16 have substantially the same construction and are located symmetrically opposite to each other with respect to an array of warp yarns Y 2 which are passed on and stretched between rollers 18 and 20, moving in the direction indicated by an arrow. The rollers 18 and 20 are rotatably supported by side frame members 22 and 24, respectively. The reference numerals 26 and 28 denote a heald and a reed, respectively.
As shown in FIGS. 2 and 3, the first binding device 14 is composed of a sun gear 30 which is fixed on a shaft 32. The shaft 32 is fixed to a bracket 34 secured with a screw 36 to the body (no numeral) of the shuttleless loom 10. A cylindrical carrier 40 is rotatably mounted on the shaft 32 through a bearing 41. The carrier 40 is formed at its peripheral surface with a ring gear portion 40a which is meshed with a gear 42. The gear 42 is secured on a drive shaft 44 which is rotatably supported by bearings 46 and 48 and operatively connected to a driving source (not shown). The carrier 40 is, in this instance, rotated by one-half turn at each pick of the weft yarn.
Two planet gears 50 and 52 are rotatably carried or mounted on the carrier 40 and located symmetrically opposite to each other with respect to the shaft 32 of the sun gear 30. The planet gears 50 and 52 mesh with the sun gear 30 as shown. Two auxiliary planet gears 54 and 56 also rotatably carried or mounted on the carrier 40. The auxiliary planet gears 54 and 56 mesh with the planet gears 50 and 52, respectively, but do not mesh with the sun gear 30. In this case, the gear ratio between the sun gear 30 and each auxiliary gear 54 or 56 is 2:1. It is to be noted that the auxiliary planet gears 54 and 56 rotate themselves in the direction opposite to that of their revolutions.
Two bobbin holders 58 and 60 are fixedly mounted on the auxiliary planet gears 54 and 56, respectively. Two bobbins B 1 and B 2 are rotatably mounted respectively on two shafts 62 and 64 which are supported by the bobbin holders 58 and 60, respectively. Accordingly, the bobbins B 1 and B 2 rotate integrally with the auxiliary planet gears 54 and 56. The binding yarns b 1 and b 2 are wound on the bobbins B 1 and B 2 , respectively. The bobbin holders 58 and 60 are equipped respectively with binding yarn control devices (no numerals) for providing tension to the binding yarns b 1 and b 2 from this first binding device 14. The binding yarn control devices comprise rotatable shafts 66 and 68 which are rotatably supported by the bobbin holders 58 and 60, respectively. Bobbin stop levers 70 and 72 are secured to the shafts 66 and 68, respectively, and provided with Y-shaped cut-out portions 70a and 72a, respectively. The reference numerals 74 and 76 represent pawls meshed with ratchet wheels 78 and 80, which are secured to the shafts 66 and 68, respectively. Release levers 82 and 84 are rotatably mounted on the shafts 66 and 68, respectively. The release levers 82 and 84 are biased in the counterclockwise direction by springs (not shown) and provided with release bars 82a and 84a (only their parts shown), respectively.
The binding yarns b 1 and b 2 wound on the bobbins B 1 and B 2 are firstly passed through Y-shaped cut-out portions 70a and 72a and secondly passed on tbe release bars 82a and 84a, and lastly passed through guide openings (no numerals) formed through guide members 86 and 88 fixed to the bobbin holders 58 and 60, respectively. Such binding yarn control devices are known and their operations have been omitted for the purpose of simplicity of explanation. Meanwhile, the binding yarns b 1 and b 2 from the guide openings of the guide members 86 and 88 are guided as shown in FIG. 2 to form the selvage structures S 1 and S 2 at the both sides of the fabric F.
With this first binding device 14, when the carrier 40 is rotated in the direction of an arrow a in FIG. 2 with rotation of the gear 42, the planet gears 50 and 52 are rotated in the direction of arrows b and therefore the auxiliary planet gears 54 and 56 are rotated in the direction of dotted arrows c. As the auxiliary planet gears 54 and 56 rotate, the guide openings of the guide members 86 and 88 rotate around the axis of the sun gear 30. Consequently, the binding yarns b 1 and b 2 alternately continue the opening and closing (crossing) actions thereof, being twisted in the same direction. Therefore, when the crossed binding yarns b 1 and b 2 open or separate from each other, the weft yarn Y 1 picked into the shed of the warp yarns Y 2 is inserted between the binding yarns b 1 and b 2 . Then, the binding yarns b 1 and b 2 cross to securely bind the one cut end portion of the picked weft yarn Y 1 . Thereafter, the binding yarns b 1 and b 2 are opened to await the next picking of the weft yarn Y 1 . It will be understood that the one of the weft yarn Y 1 is securely inserted between the binding yarns b 1 and b 2 lying between a crossing and the next crossing.
As previously stated, the second binding device 16 is constructed substantially the same as the first binding device 14 and accordingly it operates substantially the same as the first binding device 14 so as to bind the other cut end portion of the picked weft yarn Y 1 . In this regard, like reference numerals with the addition of a prime are assigned to the corresponding parts and elements. Moreover, the second binding device 16 is located by one side of the array of the warp yarns Y 2 and generally symmetrically opposite to the first binding device 14 which is located by the other side of the array of the warp yarns Y 2 .
Hence, as clearly seen from FIG. 3, the bobbin holders 58 and 60 face the bobbin holders 58' and 60'. It is to be noted that the shaft 44 is provided at its one end with a gear 90 which meshes with a gear 92. The gear 92 is secured to an end of a rotatable shaft 94 which is rotatably supported by a bearing 96 and provided at the other end thereof with a toothed pulley 98. The toothed pulley 98 is drivingly connected to another toothed pulley 100 with a toothed belt 102. The toothed pulley 100 is secured to a rotatable shaft 103 rotatably supported by a bearing 104 and is provided with a gear 106 which is meshed with the ring gear portion 40a' of the cylindrical carrier 40' of the second binding device 16. In this instance, the gear ratio between the gears 42 and 106 are 1:1. The gear ratio between the gears 90 and 92 is the same as that between the toothed gears 100 and 98.
In operation of the above-mentioned selvage forming system including the first and second binding devices 14 and 16, when the drive shaft 44 is rotated, the gears 42 and 106 rotate in the opposite directions to each other to rotate the cylindrical carriers 40 and 40' in the opposite directions to each other, respectively. Accordingly, the bobbin holders 58 and 60 of the first binding device 14 are rotated in the direction opposite to the rotating direction of the bobbin holders 58' and 60' of the second device 16. Furthermore, since the first and second binding devices 14 and 16 are located generally symmetrically opposite to each other, the binding yarns b 1 and b 2 drawn from the guide openings of the guide members 86 and 88 are twisted in the same direction as in the binding yarns b 1 ' and b 2 ' drawn from the guide openings of the guide members 86' and 88'. Of course, all the binding yarns themselves are twisted in the same direction. It will be appreciated from the foregoing, that each binding yarn is prevented from its tensile strength lowering caused by cancellation of the previously applied twistings, when the binding yarns used are preveously twisted in the same direction as that of twistings applied to the binding yarns during formation of the selvage structures S 1 and S 2 of the fabric F. Therefore, the binding yarns are prevented from being damaged and cut and accordingly rigid selvage structures can be formed at the both sides of a woven fabric. In this connection, it is preferable to use, as the binding yarns b 1 , b 2 , b 1 ' and b 2 ', two-ply yarns which are formed by preveously twisted in the same direction as that of the twistings applied to the binding yarns during the forming the selvage structures S 1 and S 2 .
While the first and second binding devices 14 and 16 have been shown and described to be symmetrically opposite to each other, it will be understood that they may be located so as to be directed in the same direction, in which event the cylindrical carriers 40 and 40' may be rotated in the same direction. In such a case, since the guide openings of the guide members of one binding device 14 or 16 are far from the array of warp yarns Y 2 , it may be required to install a further binding yarn guiding means (not shown) for guiding the two binding yarns drawn from the above-mentioned guide openings to the corresponding side of the array of warp yarns Y 2 .
FIG. 4 illustrates another type of binding device 110 forming part of a selvage forming device (no numeral) also to which the principle of the present invention is applicable. Such a type of the binding device is known per se and comprises first and second bobbins 112 and 114 on which first and second binding yarns y 1 and y 2 are wound, respectively. The first and second bobbins 112 and 114 are rotatably carried on a first rotatable disc 116 which is formed at its peripheral surface with a ring gear portion (no numeral). The rotatable disc 116 is formed with first and second guide openings 118 and 120 through which first and second binding yarns y 1 and y 2 are guided toward a second rotatable disc 122. The first and second guide openings 118 and 120 are located so as to be diametrically opposed.
As clearly viwed in FIG. 4, the first and second rotatable discs 116 and 122 are meshed at their ring gear portions (no numerals) with the ring gear portion (no numeral) of a counter gear 124. Moreover, the first and second rotatable discs 116 and 122 lie in a plane which is substantially perpendicular to the array of weft yarns (not shown). The second rotatable disc 122 is formed at its central portion with a central guide opening 126 through which the first and second binding yarns y 1 and y 2 from the first rotatable disc 116 pass. The first and second binding yarns Y 1 and Y 2 from the central guide opening 126 are respectively guided to first and second peripheral guide openings 128 and 130 through which the first and second binding yarns y 1 and y 2 are guided to one side of a woven fabric 132. The first and second peripheral guide openings 128 and 130 are located to be diametrically opposed.
With the thus arranged binding device 110, as the first rotatable disc 116 rotates so that its first guide opening 118 approaches to, and the second guide opening 120 separates from, the central guide opening 126 of the second rotatable disc 122, the second rotatable disc 122 rotates so that its first peripheral guide opening 128 separates from and the second peripheral guide opening 130 approaches to the woven fabric 132. In this state, the first and second binding yarns y 1 and y 2 between the second rotatable disc 122 and the woven fabric 132 are close to each other to cross each other. Therefore, with rotations of the first and second rotatable discs 116 and 122, the first and second binding yarns y 1 and y 2 between the second rotatable disc 122 and the woven fabric 132 separate from each other as the state shown in FIG. 4. It will be understood that the weft yarn is picked between the first and second binding yarns Y 1 and Y 2 adjacent the woven fabric 132 and therefore the end of the picked weft yarn is secured or bound between the first and second binding yarns y 1 and y 2 .
While only one binding device 110 has been shown and described to form a selvage structure at one side of the fabric, it will be understood that another binding device (no shown) may be used to form another selvage structure at the other side of the fabric, in which the two binding devices are located so that all binding yarns from the two binding devices are twisted in the same direction.
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A selvage forming system of a shuttleless loom, comprising two binding devices for respectively binding both sides of a fabric to form selvage structures, the two binding devices being located to cause all of the binding yarns to twist in the same direction during weaving operation, thereby preventing either one of selvage structures from being easily broken.
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BACKGROUND OF THE INVENTION
[0001] The present invention relates to a pigmented paint formulation containing a phosphorus acid functionalized latex binder and an associative thickener that is designed to give formulators flexibility in targeting a desired Stormer viscosity of the composition, particularly when elevated ICI viscosity is desired.
[0002] Titanium dioxide (TiO 2 ) is widely used to create opacity in paint formulations due to its high index of refraction. The rapid rise in the cost in TiO 2 has led to the search for more efficient ways to reduce concentrations of this pigment without sacrificing hiding. Efficiency can be achieved by improving the spacing between TiO 2 particles, for example, by adsorbing phosphorus acid functionalized emulsion polymer particles to the surfaces of the TiO2 particles. (See, for example, U.S. Pat. No. 7,081,488, U.S. Pat. No. 7,179,531, and US 2015/000546 A1). The resulting composite structures exhibit an increase in viscosity efficiency, which may adversely affect a formulator's ability to tailor the KU rheological response to a desired viscosity using a traditional thickener such as a hydrophobically modified ethylene oxide urethane (HEUR) polymer thickener.
[0003] It would therefore be desirable to discover a composition that provides both efficient use TiO 2 and KU building capability. Such a composition would facilitate viscosity adjustment of a paint formulation at high shear rates in the presence of composite particles without exceeding viscosity targets at low and mid shear rates, and would have the added benefit of increased flexibility in the use of low and mid shear rate thickeners to balance other paint performance properties.
SUMMARY OF THE INVENTION
[0004] The present invention addresses a need in the art by providing a composition comprising an aqueous dispersion of a) from 0.02 to 2 weight percent, based on the weight of the composition, of an associative thickener having a hydrophobic portion with a calculated log P in the range of from 2.7 to 4.8; and b) from 5 to 60 weight percent, based on the weight of the composition, of composite particles comprising phosphorus acid functionalized polymer particles adsorbed to the surfaces of TiO 2 particles; wherein the volume solids content of the composition is in the range of from 30 to 44 volume percent, with the proviso that when the volume solids content is in the range of from 30 to 36 volume percent, the calculated log P of the hydrophobic portion of the associative thickener is in the range of from 4.0 to 4.8.
DETAILED DESCRIPTION OF THE INVENTION
[0005] The present invention is a composition comprising an aqueous dispersion of a) from 0.02 to 2 weight percent, based on the weight of the composition, of an associative thickener having a hydrophobic portion with a calculated log P in the range of from 2.7 to 4.8; and b) from 5 to 60 weight percent, based on the weight of the composition, of composite particles comprising phosphorus acid functionalized polymer particles adsorbed to the surfaces of TiO 2 particles;
[0006] wherein the volume solids content of the composition is in the range of from 30 to 44 volume percent, with the proviso that when the volume solids content is in the range of from 30 to 36 volume percent, the calculated log P of the hydrophobic portion of the associative thickener is in the range of from 4.0 to 4.8.
[0007] As associative thickener comprises a water soluble polymeric backbone with terminal or internal hydrophobic groups or both. Preferably, the concentration of the associative thickener is from 0.1 to 1 weight percent. Examples of suitable backbones include polyether, polymethacrylamide, polysaccharide, or polyvinyl backbones, preferably, a polyether backbone. More preferably, the associative thickener is a hydrophobically modified alkylene oxide urethane polymer, most preferably a hydrophobically modified ethylene oxide urethane polymer (a HEUR). This polymer may be prepared by contacting together under reactive conditions a) a diisocyanate; b) a water-soluble polyalkylene glycol; and c) a capping agent. Examples of suitable diisocyanates include 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethyl-1,6-diisocyanatohexane, 1,10-decamethylene diisocyanate, 4,4′-methylenebis(isocyanatocyclohexane), 2,4′-methylenebis(isocyanatocyclohexane), 1,4-cyclohexylene diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane (IPDI), m-and p-phenylene diisocyanate, 2,6-and 2,4-toluene diisocyanate, xylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4,4′-biphenylene diisocyanate, 4,4′-methylene diphenylisocyanate, 1,5-naphthylene diisocyanate, and 1,5-tetrahydronaphthylene diisocyanate.
[0008] A water-soluble polyalkylene glycol refers to water-soluble polyethylene oxides, water-soluble polyethylene oxide/polypropylene oxide copolymers, and water-soluble polyethylene oxide/polybutylene oxide copolymers. As used herein, the term propylene oxide refers to either a polymer having —(OCH 2 CH 2 CH 2 )— and/or —(OCH(CH 3 )CH 2 )— repeating groups.
[0009] Preferred water-soluble polyalkylene oxides are polyethylene glycols, particularly polyethylene glycols having a weight average molecular weight in the range of from 4000, more preferably from 6000, and most preferably from 7000 to 20,000, more preferably to 12,000 and most preferably to 9000 Daltons. An example of a suitable polyethylene glycol is PEG 8000, which is commercially available as CARBOWAX™ 8000 Polyethylene Glycol (a trademark of The Dow Chemical Company (“Dow”) or an affiliate of Dow, Midland, Mich.).
[0010] A branched hydrophobically modified alkylene oxide urethane polymer may be prepared, for example, by reacting a compound with at least three isocyanate groups with a stoichiometric excess of a water-soluble polyalkylene glycol, followed by reaction of the intermediate with a stoichiometric excess of a diisocyanate to form a branched polyurethane polymer with isocyanate groups, followed by capping of the isocyanate groups with a capping agent. Examples of preferred compounds with three isocyanate groups include cyanurate and biuret trimers such as HDI isocyanurate (trimer), and IPDI isocyanurate (trimer), as illustrated:
[0000]
[0011] The hydrophobic portion from which calculated log P (cLog P) is derived is characterized by either of the following formulas:
[0000]
[0012] where the oxygen atom is covalently bonded to the polymer backbone (squiggly line) through a saturated carbon atom; where R 1 is a divalent group and R 2 and R 3 are monovalent groups selected to achieve the desired cLog P.
[0013] Preferably, R 1 is a C 4 -C 14 alkyl, a C 5 -C 8 cycloalkyl, or a combination of C 1 -C 9 alkyl and C 5 -C 7 cycloalkyl groups.
[0014] Preferably, R 2 is a C 3 -C 10 alkyl, a C 5 -C 8 cycloalkyl, or a benzyl group; X is O or NR 2 ′ where R 2 ′ is H or a monovalent group selected to achieve the desired cLog P. Preferably R 2 ′ is H, a C 1 -C 6 -alkyl, a benzyl, or a C 5 -C 8 cycloalkyl group. Alternatively, R 2 is a tertiary amine containing alkyl, cycloalkyl, or aromatic group that is within the scope of the desired cLog P range of this invention.
[0015] R 3 is preferably a C 7 -C 11 -alkyl, a dibenzylamino-C 2 -C 5 -alkyl, a di-C 4 -C 6 -alkylamino-C 1 -C 4 — alkyl, a C 6 -C 8 -alkylphenyl group.
[0016] The cLog P is determined using ChemBioDraw Ultra 13.0 (PerkinElmer), which uses a chemical fragment algorithm method for assessing the partition coefficient of a molecule based on its constituent parts.
[0017] Examples of combinations of R 1 , R 2 , and R 2 ′ groups within the scope of the desired cLog P range are as follows:
[0000]
R 1
R 2
R 2 ′
X
cLog P
-H 12 MDI-
CH 3 (CH 2 ) 3 —
—
O
4.68
-H 12 MDI-
CH 3 (CH 2 ) 2 —
—
O
4.15
-IPDI-
benzyl
—
O
3.87
-IPDI-
CH 3 (CH 2 ) 5 —
—
O
4.75
-IPDI-
CH 3 (CH 2 ) 4 —
—
O
4.22
-IPDI-
CH 3 (CH 2 ) 3 —
—
O
3.69
-HDI-
CH 3 (CH 2 ) 7 —
—
O
4.34
-HDI-
CH 3 (CH 2 ) 6 —
—
O
3.81
-HDI-
CH 3 (CH 2 ) 5 —
—
O
3.29
-HDI-
CH 3 (CH 2 ) 4 —
—
O
2.76
-HDI-
CH 3 (CH 2 ) 3 —
CH 3 (CH 2 ) 3 —
NR 2 ′
3.16
-HDI-
CH 3 (CH 2 ) 4 —
CH 3 (CH 2 ) 4 —
NR 2 ′
3.76
-HDI-
CH 3 (CH 2 ) 5 —
H
NR 2 ′
2.90
-HDI-
CH 3 (CH 2 ) 6 —
H
NR 2 ′
3.42
-HDI-
CH 3 (CH 2 ) 7 —
H
NR 2 ′
3.95
-HDI-
benzyl
benzyl
NR 2 ′
3.42
-HDI-
cyclohexyl
cyclohexyl
NR 2 ′
4.05
-HDI-
(benzyl) 2 NCH 2 CH 2 —
—
O
4.62
-H 12 MDI-
benzyl
CH 3 —
NR 2 ′
4.37
-H 12 MDI-
cyclohexyl
H
NR 2 ′
4.74
-IPDI-
CH 3 (CH 2 ) 3 —
CH 3 (CH 2 ) 3 —
NR 2 ′
4.62
-IPDI-
CH 3 (CH 2 ) 5 —
H
NR 2 ′
4.36
[0018] where -H 12 MDI- refers to fragments of isomers of methylenebis(isocyanatocyclohexane):
[0000]
[0019] -IPDI- refers to a fragment of 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane:
[0000]
[0020] -HDI- refers to a fragment of hexamethylene diiscocyanate:
[0000]
[0021] where the dotted lines represent the points of attachment of R 1 to the NH groups.
[0022] Examples of suitable —OR 3 groups include —O-n-undecyl (cLog P=4.42), —O-n-decyl (cLog P=3.89), —O-n-nonyl (cLog P=3.36), —O-n-octyl (cLog P=2.83), —O-2-ethylhexyl (cLog P=2.70), —O-3,5,5-trimethylhexyl (cLog P=2.97), —O-3,7-dimethyloctyl (cLog P=3.63), —O-dibenzylaminoethyl (cLog P=3.10), —O-2-propylheptyl (cLog P=3.76), —O-diamylaminoethyl (cLog P=3.76), —O-n-octylphenyl (cLog P=4.77), and —O-2,6-dimethylheptyl (cLog P=3.10).
[0023] The preferred cLog P of the fragment depends on the volume solids content of the composition. When the volume solids is from 30 to 36 volume percent, the cLog P of the fragment is from 4.0, and preferably from 4.2, to 4.8, preferably to 4.7; when the volume solids is from 36 to 44 volume percent, the cLog P of the fragment is from 2.7, preferably from 3.0, and more preferably from 3.5 to 4.8, preferably to 4.7.
[0024] The phosphorus acid functionalized polymer particles are spherical and can be prepared by a variety of emulsion polymerization techniques, such as those disclosed in US 2012/0058277 A1.
[0025] In a preferred method of preparing the spherical phosphorus acid functionalized polymer particles, first monomers comprising a) from 0.5, and more preferably from 1, to 15 more preferably to 10, and most preferably to 7 weight percent of a phosphorus acid monomer or a salt thereof; b) from 0.2, and more preferably from 0.5, to 20, preferably to 10, and more preferably to 4 weight percent of a carboxylic acid monomer or a sulfur acid monomer or salts thereof or combinations thereof; and c) from 50 to 95 weight percent structural units of a polymerizable ethylenically unsaturated bulk monomer are copolymerized under emulsion polymerization conditions. As used herein, a polymerizable ethylenically unsaturated bulk monomer refers to a styrene monomer or an acrylate monomer or a combination thereof.
[0026] Preferred polymerizable ethylenically unsaturated bulk monomers include a combination of the following monomers: i) from methyl methacrylate or styrene or a combination thereof at a concentration preferably in the range of from 35 weight percent, to 74.9 weight percent, more preferably to 65 weight percent, and most preferably to 55 weight percent based on the weight of the first monomers; and ii) ethyl acrylate, butyl acrylate, or 2-ethylhexyl acrylate or a combination thereof, preferably, at a concentration in the range of from 25 weight percent, more preferably from 45 weight percent to preferably 64.9, and more preferably to 60 weight percent, based on the weight of the first monomers. A more preferred combination of bulk monomers is methyl methacrylate or styrene or a combination thereof with ethyl acrylate, butyl acrylate, or 2-ethylhexyl acrylate or a combination thereof, with methyl methacrylate and butyl acrylate being especially preferred.
[0027] As used herein, the term “structural unit” of the named monomer, refers to the remnant of the monomer after polymerization. For example, a structural unit of methyl methacrylate is as illustrated:
[0000]
structural unit of methyl methacrylate where the dotted lines represent the points of attachment of the structural unit to the polymer backbone.
[0029] Examples of suitable phosphorus acid monomers include phosphonates and dihydrogen phosphate esters of an alcohol in which the alcohol contains or is substituted with a polymerizable vinyl or olefinic group. Preferred dihydrogen phosphate esters are phosphates of hydroxyalkyl(meth)acrylates, including phosphoethyl methacrylate and phosphopropyl methacrylates, with phosphoethyl methacrylate being especially preferred. “Phosphoethyl methacrylate” (PEM) is used herein to refer to the following structure:
[0000]
[0030] where R is H or
[0000]
[0031] wherein the dotted line represents the point of attachment to the oxygen atom.
[0032] The first monomers are advantageously polymerized under emulsion polymerization conditions followed by addition of second monomers and a second stage polymerization. Alternatively, the second monomers can be polymerized in a first stage followed by polymerization of the first monomers in a second stage. The second monomers preferably comprise the same ranges of monomers as the first monomers except that the second monomers are preferably substantially free of phosphorus acid monomers. As used herein, the term “substantially free of phosphorus acid monomers” means that the second monomers comprise less than 0.1, more preferably less than 0.01 weight percent structural units of a phosphorus acid monomer, based on the weight of the second monomers. The second monomers most preferably include no structural units of a phosphorus acid monomer.
[0033] The composite can be prepared by mixing the aqueous dispersion of the phosphorus acid functionalized polymer particles with TiO 2 particles in any order and optionally in the presence of other ingredients used in a paint formulation. The preferred concentration of the composite particles in the composition is from 20 to 40 weight percent, based on the weight of the composition.
[0034] The hydrophobically modified alkylene oxide urethane polymer rheology modifier, preferably the HEUR, is advantageously combined with the aqueous dispersion of the composite and other ingredients selected from the group consisting of dispersants, defoamers, surfactants, solvents, non-phosphorus acid functionalized binders, additional thickeners, extenders, coalescents, biocides, and colorants.
[0035] A water-based paint formulation that contains the above-described composite and rheology modifier has a Stormer viscosity that is sufficiently low that a formulator can add from 0.2 to 4.0 dry lbs/100 gal (0.2 g to 4.8 dry g/L) of KU builder to increase Stormer viscosity to the desired level. KU builders offer performance advantages in formulated paints through improved heat age stability, viscosity retention upon tinting, in-can feel, or syneresis resistance. The flexibility to choose from a range of KU builders for a given formulation is also advantageous for tailoring sag resistance and the flow/leveling performance.
EXAMPLES
[0036] Abbreviations
[0000]
CARBOWAX ™ 8000 Polyethylene Glycol
PEG 8000
DESMODUR W Diisocyanate
H 12 MDI
Hexamethylene diisocyanate
HDI
DESMODUR N3600 HDI Trimer
HDI Trimer
Isophorone diisocyanate
IPDI
Butylated Hydroxytoluene
BHT
Pigment Volume Concentration
PVC
Volume Solids
VS
ACRYSOL ™ RM-995 Rheology Modifier
RM-995
[0037] ACRYSOL and CARBOWAX are Trademarks of The Dow Chemical Company or Its Affiliates.
[0038] Intermediate 1—Preparation of PEM-Functionalized Latex Binder
[0039] A first monomer emulsion was prepared by mixing deionized water (160.0 g), Disponil FES 32 surfactant (38.1 g, 30% active), butyl acrylate (323.6 g), methyl methacrylate (396.2 g), and methacrylic acid (2.9 g). A second monomer emulsion was prepared by mixing deionized water (272.1 g), Disponil FES 993 surfactant (37.5 g, 30% active), phosphoethyl methacrylate (29.8 g, 60% active), butyl acrylate (452.7 g), methyl methacrylate (422.4 g), acetoacetoxyethyl methacrylate (74.5 g), and methacrylic acid (9.9 g).
[0040] Deionized water (1106.3 g) and Disponil FES 32 surfactant (2.3 g, 30% active) were added to a 5-L, four-necked round-bottom flask equipped with a paddle stirrer, a thermometer, nitrogen inlet, and a reflux condenser. The contents of the flask were heated to 85° C. under a N 2 atmosphere, and stirring was initiated. A portion of the first monomer emulsion (110.4 g) was added to the flask followed by a rinse of DI water (5.0 g). A solution of sodium persulfate (5.4 g) dissolved in deionized water (33.9 g), followed by a rinse of deionized water (6.7 g) was subsequently added to the reactor. After stirring for 10 min, the remainder of the first monomer emulsion was added over 45 min followed by a DI water rinse (27.0 g). An initiator solution of sodium persulfate (0.58 g) dissolved in DI water (31.7 g) was added separately added over 45 min. Stirring was continued at 85° C. for 15 min.
[0041] The second monomer emulsion and an initiator solution containing sodium persulfate (0.99 g) dissolved in DI water (52.8 g) were added linearly and separately to the vessel over 75 min. The temperature was maintained at 85° C. The second monomer emulsion vessel was rinsed to the reactor with deionized water (27 g). When all additions were complete, the contents of the flask were cooled to 65° C. and a catalyst/activator pair was added to the flask to reduce residual monomer. The polymer was then neutralized to pH 9 with dilute aqueous ammonium hydroxide. The measured particle size was 112 nm as determined using a B190 Plus Particle Size Analyzer, and the solids content was 46.1%.
[0042] RM1—Preparation of a Rheology Modifier with cLog P of 4.34
[0043] PEG 8000 (1751.1 g) was heated to 110° C. in vacuo in a batch melt reactor for 2 h. The reaction mixture was cooled to 85° C. BHT (0.184 g) and 1-octanol (29.66 g) were added to the reactor and the reaction mixture was stirred for 5 min. HDI (52.68 g) was then added to the reactor followed by 5 min of stirring. Bismuth octoate (28% Bi, 4.38 g) was then added to the reactor and the resulting mixture was stirred for 10 min at 85° C. The resulting molten polymer was removed from the reactor and cooled. Prior to testing in coating formulations, portions of this solid polymer were then dissolved in water to form a solution containing 25 wt % polymer based on the total weight of the solution.
[0044] RM2—Preparation of a Rheology Modifier with cLog P of 4.68
[0045] PEG 8000 (1700.0 g) was heated to 110° C. in vacuo in a batch melt reactor for 2 h. After cooling the reactor contents to 85° C., BHT (0.179 g), butanol (12.87 g), H 12 MDI (62.57 g), and HDI Trimer (7.95 g) were added sequentially to the reactor and allowed to mix for 5 min. Bismuth octoate (28% Bi, 4.25 g) was then added to the reactor and the temperature of the mixture was maintained at 85° C. with stirring for 10 min. The resulting molten polymer was removed from the reactor and cooled. Prior to testing in coating formulations, portions of this solid polymer were then dissolved in water to form a solution containing 20 wt % polymer based on the total weight of the solution.
[0046] RM3—Preparation of a Rheology Modifier with cLog P of 5.74
[0047] PEG 8000 (1711.9 g) was heated to 110° C. in vacuo in a batch melt reactor for 2 h. While maintaining a reaction temperature of 110° C., BHT (0.182 g) and hexanol (18.91 g) were added to the reactor and the reaction mixture was stirred for 5 min. H 12 MDI (77.85 g) was then added to the reactor followed by 5 min of stirring. Bismuth octoate (28% Bi, 4.28 g) was then added to the reactor and the resulting mixture was stirred for 10 min at 110° C. Subsequently, hexanol (3.26 g) was added to the reactor and mixing continued for another 10 minutes at 110° C. The resulting molten polymer was removed from the reactor and cooled. Prior to testing in coating formulations, portions of this solid polymer were then dissolved in water to form a solution containing 20 wt % polymer based on the total weight of the solution.
[0048] RM4—Preparation of a Rheology Modifier with cLog P of 5.40
[0049] PEG 8000 Polyethylene Glycol (1700.0 g) and LUMULSE POE(26) glycerine (43.36 g) were heated to 110° C. in vacuo in a batch melt reactor for 2 h. After cooling the reactor contents to 85° C., BHT (0.185 g), 1-decanol (38.88 g), and HDI (59.01 g) were added sequentially to the reactor and allowed to mix for 5 min. Bismuth octoate (28% Bi, 4.25 g) was then added to the reactor and the temperature of the mixture was maintained at 85° C. with stirring for 20 min. The resulting molten polymer was removed from the reactor and cooled. Prior to testing in coating formulations, portions of this solid polymer were then dissolved in water to form a solution containing 18.5 wt % polymer based on the total weight of the solution.
[0050] RM5—Preparation of a Rheology Modifier with cLog P of 6.33
[0051] PEG 8000 (1854.8 g) and LUMULSE POE(26) glycerine (46.60 g) were heated to 110° C. in vacuo in a batch melt reactor for 2 h. After cooling the reactor contents to 85° C., BHT (0.202 g), 2-butyl-1-octanol (47.81 g), and HDI (63.41 g) were added sequentially to the reactor and allowed to mix for 5 min. Bismuth octoate (28% Bi, 4.64 g) was then added to the reactor and the temperature of the mixture was maintained at 85° C. with stirring for 20 min. The resulting molten polymer was removed from the reactor and cooled. Prior to testing in coating formulations, portions of this solid polymer were then dissolved in water to form a solution containing 17.5 wt % polymer based on the total weight of the solution.
[0052] RM6—Preparation of a Rheology Modifier with cLogP of 4.37
[0053] A mixture of PEG 8000 (150 g) and toluene (400 g) were added to a vessel and dried by azeotropic distillation. The mixture was cooled to 90° C., at which time H 12 MDI (6.63 g) was added to the mixture. The mixture was stirred for 5 min, and dibutyltin dilaurate (0.21 g) was added. The mixture was stirred for 1 h, then cooled to 80° C. followed by the addition of N-methylbenzylamine (2.23 g). The mixture was stirred for an additional 1 h, then cooled to 60° C. Solvent was removed in vacuo and the polymer was isolated.
[0054] RM7—Preparation of a Rheology Modifier with cLogP of 4.62
[0055] A mixture of PEG 8000 (150 g) and toluene (400 g) were added to a vessel and dried by azeotropic distillation. The mixture was cooled to 90° C., at which time HDI (4.25 g) was added to the mixture. The mixture was stirred for 5 min and dibutyltin dilaurate (0.21 g) was added. The mixture was stirred for 1 h, then cooled to 80° C. followed by addition of N,N-dibenzylaminoethanol (4.44 g). The mixture was stirred for an additional 1 h, then cooled to 60° C. Solvent was removed in vacuo and the polymer was isolated.
Example 1
Paint Thickened with RM1 at 18% PVC, 35.6% VS
[0056] A. Premix
[0057] Intermediate 1 (462 g), water (109 g), KRONOS 4311 TiO 2 slurry (412 g, 76.5% solids), and ammonia (0.88 g, 29% aq.) were mixed using an overhead mixer for 10 min. Intermediate 1 (440 g), BYK-348 surfactant (4.8 g), FOAMSTAR A-34 defoamer (2.0 g), water (6.6 g) and TEXANOL coalescent (12.0 g) were then added sequentially and mixed for an additional 5 min.
[0058] B. Letdown
[0059] Premix (193.4 g), water (3.95 g), RM1 (5.63 g, 25% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.91 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Example 2
Paint Thickened with RM2 at 18% PVC, 35.6% VS
[0060] A. Premix
[0061] The premix was prepared the same as described in Example 1, Part A.
[0062] B. Letdown
[0063] Premix (193.4 g), water (3.93 g), RM2 (5.62 g, 20% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.94 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Example 3
Paint Thickened with RM1 at 18% PVC, 38.9% VS
[0064] A. Premix
[0065] Intermediate 1 (404 g), water (46.3 g), and KRONOS 4311 TiO 2 slurry (361 g, 76.5% solids), and ammonia (0.68, 28% aq.) were mixed using an overhead mixer for 10 min. Intermediate 1 (385 g), BYK-348 surfactant (4.2 g), FOAMSTAR A-34 defoamer (1.8 g), and TEXANOL coalescent (10.5 g) were then added sequentially and mixed for an additional 5 min.
[0066] B. Letdown
[0067] Premix (202.1 g), water (0.31 g), RM1 (4.09 g, 25% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.49 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Comparative Example 1
Paint Thickened with RM3 at 18% PVC, 35.6% VS
[0068] A. Premix
[0069] The premix was prepared the same as described in Example 1, Part A.
[0070] B. Letdown
[0071] Premix (193.4 g), water (4.51 g), and RM3 (5.98 g, 20.0% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Comparative Example 2
Paint Thickened with RM4 at 18% PVC, 35.6% VS
[0072] A. Premix
[0073] The premix was prepared the same as described in Example 1, Part A.
[0074] B. Letdown
[0075] Premix (193.4 g), water (6.47 g), and RM3 (4.02 g, 20.0% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Comparative Example 3
Paint Thickened with RM5 at 18% PVC, 35.6% VS
[0076] A. Premix
[0077] The premix was prepared the same as described in Example 1, Part A.
[0078] B. Letdown
[0079] Premix (193.4 g), water (6.92 g), and RM5 (3.57 g, 17.5% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
[0080] B. Letdown
[0081] Premix (202.1 g), water (0.31 g), RM1 (4.09 g, 25% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.49 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Comparative Example 4
Paint Thickened with RM3 at 18% PVC, 38.9% VS
[0082] A. Premix
[0083] The premix was prepared the same as described in Example 3, Part A.
[0084] B. Letdown
[0085] Premix (202.1 g), water (0.25 g), and RM3 (4.64 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Comparative Example 5
Paint Thickened with RM4 at 18% PVC, 38.9% VS
[0086] A. Premix
[0087] The premix was prepared the same as described in Example 3, Part A.
[0088] B. Letdown
[0089] Premix (202.1 g), water (1.92 g), and RM4 (2.97 g, 18.5% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Example 4
Paint Thickened with RM6 at 18% PVC, 38.9% VS
[0090] A. Premix
[0091] The premix was prepared the same as described in Example 3, Part A.
[0092] B. Letdown
[0093] Premix (197.8 g), water (0.43 g), RM6 (8.30 g, 20% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.44 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Example 5
Paint thickened with RM7 at 18% PVC, 38.9% VS
[0094] A. Premix
[0095] The premix was prepared the same as described in Example 3, Part A.
[0096] B. Letdown
[0097] Premix (197.8 g), water (5.15 g), RM7 (3.76 g, 25% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.27 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Example 6
Paint Thickened with RM6 at 18% PVC, 38.9% VS
[0098] A. Premix
[0099] Intermediate 1 (404 g) and KRONOS 4311 TiO 2 slurry (361 g, 76.5% solids), and ammonia (0.68, 28%) were mixed using an overhead mixer for 10 min. Intermediate 1 (385 g), BYK-348 surfactant (4.2 g), FOAMSTAR A-34 defoamer (1.8 g), and TEXANOL coalescent (10.5 g) were then added sequentially and mixed for an additional 5 min.
[0100] B. Letdown
[0101] Premix (194.38 g), water (5.16 g), and RM6 (6.99 g, 20% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.45 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Example 7
Paint Thickened with RM7 at 18% PVC, 38.9% VS
[0102] A. Premix
[0103] The premix was prepared the same as described in Example 3, Part A.
[0104] B. Letdown
[0105] Premix (202.1 g), water (2.05 g), and RM7 (2.51 g, 25% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.33 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
Comparative Example 6
Paint Thickened with RM4 at 18% PVC, 38.9% VS
[0106] A. Premix
[0107] The premix was prepared the same as described in Example 3, Part A.
[0108] B. Letdown
[0109] Premix (202.1 g), water (2.05 g), and RM4 (2.51 g, 20% solids), and ACRYSOL™ RM-995 Rheology Modifier (0.33 g, 20% solids) were mixed together using an overhead mixture for 10 to 15 min to complete the formulation.
[0110] Table 1 illustrates KU and ICI viscosities (KU η and ICI η respectively) for amounts of RM-995 thickener added to 18 PVC paint samples. The added thickener is RM-995 in dry lbs/100 gal.
[0000]
TABLE 1
Viscosity Profiles for Thickener Added to 18 PVC Paints
Sample No.
VS %
cLog P
RM-995
RM#
KU η
ICI η (Pa · s)
Example 1
35.6
4.34
1.40
1
100.4
1.34
Example 2
35.6
4.68
0.94
2
97.0
1.25
Comp Ex 1
35.6
5.74
0.00
3
103.0
1.36
Comp Ex 2
35.6
5.40
0.00
4
99.5
1.36
Comp Ex 3
35.6
6.33
0.00
5
123.3
1.30
Example 3
38.9
4.34
0.49
1
97.4
1.38
Example 4
38.9
4.62
0.45
7
103
1.41
Comp Ex 4
38.9
5.74
0.00
3
105.4
1.32
Comp Ex 5
38.9
5.40
0.00
4
103.1
1.32
Example 5
38.9
4.34
0.30
1
90
1.02
Example 6
38.9
4.37
0.45
6
92
0.97
Example 7
38.9
4.62
0.33
7
88
1.04
Comp Ex 6
38.9
5.40
0
4
95
1.05
[0111] For Examples 1-4 and Comparative Examples 1-5, the paint viscosity was targeted at 100±3 KU and 1.3±0.1 Pa·s, whereas for the remaining samples the paint viscosity was targeted at 90±3 KU and 1.0±0.1 Pa·s. The data demonstrate that RM1, which has a cLog P of 4.34, accommodates the highest use levels of RM-995 without exceeding the Stormer viscosity target for both levels of VS studied. RM3, RM4, and RMS, all of which have cLog P values >5.0, match or exceed the KU viscosity target without any RM-995 added when targeted to the same ICI viscosity. However, the use level for KU builders is dependent on the paint formulation studied. At 38.9% VS, RM1, RM6, and RM7 were shown to be effective with RM-995 as a co-thickener. RM3 and RM4, both of which have cLog P >4.8, match or exceed the KU viscosity target without any RM-995 added. The ability to add co-thickener selectively to increase Stormer viscosity in the inventive paint formulations allows for enhanced flexibility toward designed rheology; this flexibility allows for the optimization of performance characteristics such as sag and leveling, viscosity stability, viscosity retention upon tinting, and colorant compatibility.
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The present invention relates to a composition comprising an aqueous dispersion of an associative thickener having a hydrophobic portion with a calculated log P in the range of from 2.7 to 4.8; and composite particles comprising phosphorus acid functionalized polymer particles adsorbed to the surfaces of TiO 2 particles. The composition of the present invention provides formulators with flexibility in their use of low and mid shear rate thickeners to balance paint performance properties.
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RELATED APPLICATIONS
This is a continuation-in-part of U.S. patent application Ser. No. 10/445,149, filed on May 23, 2003 now U.S. Pat. No. 6,794,778 titled “Braking System for Powered Window Covering” and co-pending U.S. patent application Ser. No. 10/786,351, filed Feb. 25, 2004 titled “Piezo-Based Encoder with Magnetic Brake for Powered Window Covering” from which priority is claimed and which are incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates generally to motorized window coverings, awnings, security screens, projection screens, and the like.
BACKGROUND OF THE INVENTION
The present assignee has provided several systems for either lowering or raising a window covering, or for moving the slats of a window covering between open and closed positions, under control of a hand-held remote or other control device. These systems include a motor that is coupled through gears to the window covering activation mechanism. When the motor is energized in response to a user command signal, the activation mechanism moves the window covering. Such assemblies are disclosed in U.S. Pat. No. 6,433,498, incorporated herein by reference.
The present assignee has also provided systems for determining the position of the window coverings based on counting motor pulses, and for braking the motor from turning when it is not energized. By knowing the position of the window coverings, features such as automatic repositioning the window covering to a preset position can be provided. The present invention likewise provides structure and methods for braking an object in the absence of power while minimizing the effects of the brake during motor operation.
In the parent application, one or more permanent magnets are disclosed that are juxtaposed with the rotor to generate a magnetic field which interferes with the rotor slots and thereby creates an extra reluctance torque on the motor shaft. The extra reluctance torque establishes a static brake, to hold the rotor from undesirably turning under the weight of the window covering when the motor is deenergized.
While effective, the present invention recognizes that even though the braking field does not unduly affect motor operation when the motor is energized, it is possible to even further reduce brake drag on the motor when it is operating.
SUMMARY OF THE INVENTION
A powered assembly includes an object that can be moved between a first configuration and a second configuration. The object may be selected from the group consisting of window coverings, awnings, skylight coverings, curtains, and screens. A motor is provided, and an actuator is coupled to the motor and the object to move the object when the motor is energized. First and second magnets are juxtaposed with the rotating member and are magnetically coupled thereto. The first magnet is oriented with its north pole toward the rotating member and the second magnet is oriented with its south pole toward the rotating member.
The magnets can be disk-shaped and can be mounted on a housing of the motor side by side each other on the housing. DC batteries can be the sole source of power for the motor. Or, the braking magnets may be parallelepiped shaped. Shallow recesses may be formed in the housing of the motor in which the braking magnets can be disposed to shorten the distance between the magnets and the motor core and, hence, strengthen the braking power of the magnets. In addition, a concentrator bar can be placed over the top of the braking magnets to close the magnetic field outside the motor and, hence, to concentrate the braking field within the motor.
In another aspect, a drive assembly for a movable object including a rod includes an electrically-powered drive structure couplable to the rod to move the object when the drive structure is energized. The drive structure has a rotating member. First and second braking magnets are closely spaced from the rotating member and are oriented with the north pole of the first magnet being substantially co-planar with the south pole of the second magnet.
In still another aspect, a method for operating an object that can be moved between a first configuration and a second configuration, with the object being selected from the group consisting of window coverings, awnings, skylight coverings, curtains, and screens, includes providing a drive structure and coupling the drive structure to the object such that the object is moved when the drive structure is energized. The method also includes closely juxtaposing at least first and second magnets with the drive structure. Using the magnets, the drive structure is braked when the drive structure is not energized. On the other hand, the magnets are oriented such that when the drive structure is energized, the average magnetic field within the drive structure is at a null. That is, when the motor is energized, little or no back electromotive force (emf) is created because the effect of the field created by the braking magnets on the rotor during operation has a null average value.
The details of the present invention, both as to its construction and operation, can best be understood in reference to the accompanying drawings, in which like numerals refer to like parts, and which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a window covering actuator, shown in one intended environment, with portions of the head rail cut away;
FIG. 2 is a perspective view of a first embodiment of the motor showing disk-shaped braking magnets;
FIG. 3 is a perspective view of a second embodiment of the motor showing parallelepiped shaped braking magnets;
FIG. 4 is a perspective view of a third embodiment of the motor showing braking magnets in shallow recesses that have been formed in the housing of the motor; and
FIG. 5 is a perspective view of a fourth embodiment of the motor showing braking magnets and a magnetic concentrator.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring initially to FIG. 1 , a motorized window covering is shown, generally designated 10 , that includes an actuator such as a rotatable rod 12 of a window covering 14 , such as but not limited to a shade assembly having raisable (by rolling up) and lowerable (by rolling down, or unrolling) shade 16 . As shown, the tilt rod 12 is rotatably mounted by means of a block 18 in a head rail 20 of the window covering 14 .
While a roll-up shade is shown, it is to be understood that the principles herein apply to a wide range of window coverings and other objects that are to be moved by motors. For example, the invention applies to raisable and lowerable pleated shades and cellular shades such as those commonly marketed under the trade names “Silhouette”, “Shangri-La”, etc. as well as to projector screens, awnings, etc. that can be raised and lowered. Moreover, while needed less in applications that require only tilting slats such as in horizontal blinds, the invention may also apply to these systems. Thus, for example, the rod 12 may be a roll-up rod of a shade, awning, or projector screen, or a tilt rod of a horizontal (or vertical) blind, or other like operator. It is thus to be further understood that the principles of the present invention apply to a wide range of window coverings and other objects including, but not limited to the following: vertical blinds, fold-up pleated shades, roll-up shades, cellular shades, skylight covers, etc. Powered versions of such shades are disclosed in U.S. Pat. No. 6,433,498, incorporated herein by reference.
In the non-limiting illustrative embodiment shown, the window covering 14 is mounted on a window frame 22 to cover a window 24 , and the rod 12 is rotatable about its longitudinal axis. The rod 12 can engage a user-manipulable baton (not shown). When the rod 12 is rotated about its longitudinal axis, the shade 16 raises or lowers between an open configuration and a closed configuration.
FIG. 1 shows that the actuator 10 can include a control signal generator, preferably a signal sensor 26 , for receiving a user command signal. Preferably, the user command signal is generated by a hand-held user command signal generator 28 , which can be an infrared (IR) remote-control unit or a radio frequency (RF) remote-control unit. Or, the user command signal may be generated by any other means of communication well known in the art, such as by manipulable manual switches 29 . The user command signals can include open, close, raise, lower, and so on.
An electronic circuit board 30 can be positioned in the head rail 20 and can be fastened to the head rail 20 , e.g., by screws (not shown) or other well-known method. The preferred electronic circuit board 30 includes a microprocessor for processing the control signals.
FIG. 1 shows that a small, lightweight electric motor 32 is coupled to a gear enclosure 34 , preferably by bolting the motor 32 to the gear enclosure 34 . The gear enclosure 34 is keyed to the rod 12 , so that as the gears in the gear enclosure 34 turn, the rod 12 rotates.
It is to be understood that the motor 32 is electrically connected to the circuit board 30 . To power the motor 32 , one or more (four shown in FIG. 1 ) primary dc batteries 36 , such as type AA alkaline batteries or Lithium batteries, can be mounted in the head rail 20 and connected to the circuit board 30 . Preferably, the batteries 36 are the sole source of power for the motor, although the present invention can also be applied to powered shades and other objects that are energized from the public ac power grid.
As set forth in the above-referenced U.S. Patent, a user can manipulate the signal generator 28 to generate a signal that is sensed by the signal sensor 26 and sent to signal processing circuitry in the circuit board 30 . In turn, the electrical path between the batteries 34 and the motor 32 is closed to energize the motor 32 and move the window covering open or closed in accordance with the signal generated by the signal generator 28 , under control of the processor on the electronic circuit board 30 . When the motor is deenergized, the braking magnets disclosed below advantageously brake the motor from turning under the weight of the window covering 14 .
Now referring to FIG. 2 , in one non-limiting implementation the motor 32 includes a motor housing 42 inside of which a rotor 44 may rotate. The rotor 44 may have, e.g., three poles. First and second permanent braking magnets 46 , 48 are closely juxtaposed with the motor. The non-limiting magnets are disk-shaped with opposing magnetic poles for each magnet being established by the flat faces of the disk. Preferably, the magnets 46 , 48 are attached to the housing 42 on a flat portion thereof by, e.g., solvent bonding the magnets to the housing 42 , with the magnets being positioned side by side each other.
In accordance with present principles, the first magnet 46 is oriented with its south pole “S” against the housing 42 and, hence, facing the rotor 44 , while the second magnet 48 is oriented with its north pole “N” against the housing 42 . Stated differently, the north pole “N” of the magnet 48 is substantially co-planar with the south pole “S” of the magnet 46 .
With this structure, the magnets 46 , 48 are magnetically coupled to the rotor 44 sufficiently to stop it from rotating when the motor 32 is deenergized. However, when the motor 32 is energized, the average magnetic field effect on the rotor generated by the magnets 46 , 48 is at a null, thereby causing little or no drag on the rotor 44 as it rotates.
FIG. 3 shows an alternate embodiment having a motor 50 on which is mounted braking magnets 52 with opposed polarities as shown. The braking magnets 52 shown in FIG. 3 can be parallelepiped shaped.
FIG. 4 shows another alternate embodiment having a motor 54 on which is mounted braking magnets 56 with opposed polarities as shown. The braking magnets 56 shown in FIG. 4 can be disk shaped as shown or they can have other shapes (e.g., they can be parallelepiped shaped.) In any case, shallow recesses 58 that are preferably configured to match the contours of the braking magnets 56 are formed in the housing of the motor (but not through the case). With this structure, the distance between the magnets 56 and the core of the motor is shortened and, hence, the braking force of the magnets on the motor strengthened.
FIG. 5 shows yet another alternate embodiment having a motor 60 on which is mounted braking magnets 62 with opposed polarities as shown. The braking magnets 62 shown in FIG. 5 can be disk shaped as shown or they can have other shapes (e.g., they can be parallelepiped shaped.) In any case, a magnetic concentrator 64 , such as an elongated ferromagnetic bar, can be placed on top of the braking magnets 62 to sandwich the magnets 62 between the concentrator 64 and motor 60 and thereby close the magnetic field beyond the braking magnets opposite the motor 60 . This serves to strengthen the magnetic braking field inside the motor, permitting the use of smaller magnets if desired. The concentrator 64 can have rounded ends as shown to match the contours of the braking magnets 62 in the event that the braking magnets 62 are disk shaped. The length of the non-limiting concentrator can equal the diameters of the braking magnets plus the distance between the braking magnets as shown.
While the particular MAGNETIC BRAKE FOR POWERED WINDOW COVERING as herein shown and described in detail is fully capable of attaining the above-described aspects of the invention, it is to be understood that it is the presently preferred embodiment of the present invention and thus, is representative of the subject matter which is broadly contemplated by the present invention, that the scope of the present invention fully encompasses other embodiments which may become obvious to those skilled in the art, and that the scope of the present invention is accordingly to be limited by nothing other than the appended claims, in which reference to an element in the singular is not intended to mean “one and only one” unless explicitly so stated, but rather “one or more.” All structural and functional equivalents to the elements of the above-described preferred embodiment that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the present claims. Moreover, it is not necessary for a device or method to address each and every problem sought to be solved by the present invention, for it is to be encompassed by the present claims. Furthermore, no element, component, or method step in the present disclosure is intended to be dedicated to the public regardless of whether the element, component, or method step is explicitly recited in the claims. No claim element herein is to be construed under the provisions of 35 U.S.C. section 112, sixth paragraph, unless the element is expressly recited using the phrase “means for.”
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Two braking magnets are attached to the housing of a motor of a motorized component such as a window covering, with one magnet north face down and the other magnet south face down. With this structure the motor is braked from turning under the weight of the window covering when deenergized, while during operation the average null value of the braking field results in minimal drag on the motor.
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CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE
This application claims priority to Provisional Patent Application No. 60/957,880 having a filing date of Aug. 24, 2007, entitled “Method and Apparatus for Water Surge Protection,” which is hereby incorporated by reference herein in its entirety.
FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[Not Applicable]
MICROFICHE/COPYRIGHT REFERENCE
[Not Applicable]
FIELD OF THE INVENTION
Certain embodiments of the present invention relate to water surge protection. More specifically, certain embodiments of the present invention provide for protecting a water distribution system from main breaks caused by sudden pressure spikes in the distribution system.
BACKGROUND OF THE INVENTION
A conventional city water distribution system is a network of pumps, pipelines, storage tanks, fire hydrants, and the like. The water main pipes are typically buried underground, in dedicated easements. A water distribution system delivers quantities of water at pressures sufficient for supply customers and firefighting equipment while avoiding excess pressure which could cause leaks and pipeline breaks. Water customer services are attached to the water main, and water is carried from the water distribution system into customers' homes or businesses.
Fire hydrants are typically fed by an underground supply pipe and typically include underground shut-off valves which control the flow of water to each hydrant. Fire hydrants contain manually operable valves which are operated by a fireman to release water from the underground supply pipe in an event of a fire or during a training exercise. Also, hydrants may be opened by city workers or others in order to clear sedimentation from the water mains. Typically, the hydrant valve is located underground. Except in tropical climates where the ground does not freeze, it is generally necessary to bury below the frost line all of the parts of the system which normally retain standing water or slowly moving freezable liquids. A drain valve is normally open, draining the hydrant barrel while the hydrant valve is closed.
The hydrant valve is usually controlled by a stem extending vertically from the buried valve and passing through the top of the hydrant. A shut-off auxiliary valve, which is separate from the hydrant valve, is usually provided with an access conduit extending vertically to a removable access cover located at ground level adjacent to the hydrant. The access cover is removed and a removable wrench, commonly known as a valve key, is inserted through the access conduit to operate the shut-off valve.
A water surge can be a severe problem in a distribution system. A water surge results when a valve at one point in a distribution system is opened or shut suddenly, creating shockwaves of moving water upstream and downstream of that valve. In addition, when a pump or other source providing pressure on the water in the main is actuated, additional flows are created or diminished. Since water is essentially incompressible, it does not absorb the energy of the shockwave, but transmits it throughout the distribution system to nearby or distant parts of the system which are not isolated behind a closed valve. The turbulence created by the shockwave seeks a release point. Elevated water tanks are common release points but often are not close to the source of turbulence. Without a planned release point, the turbulence may create its own release point at a weak point in the distribution system, causing a water main break or other damage to the distribution system.
A water surge is capable of parting joints, breaking water mains and other components of the system. Since the system is mostly buried, occasionally time is required to pinpoint the damage area and then correct the resulting damage. The water escaping from the damaged system can cause a pressure failure, a pavement collapse, or other damage. It is sometimes very dangerous to repair. The danger occurs with trench cave-ins during working and with the possibility of breaking, or causing an explosion of a gas or other utility line.
Water main breaks are a costly and time consuming problem for municipalities. A system and method for water surge protection may minimize the frequency of water main breaks. Thus, there is a need for a system and method for protecting a water distribution system from main breaks caused by sudden pressure spikes in the distribution system.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.
BRIEF SUMMARY OF THE INVENTION
A system and method for water surge protection is provided for protecting a water distribution system from main breaks caused by sudden pressure spikes in the distribution system.
These and other advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
FIG. 1 is a schematic view of a water distribution system or a portion thereof, in accordance with an embodiment of the present invention.
FIG. 2 is a side view of an embodiment of a surge suppressor tank apparatus, in accordance with the present invention.
FIG. 3 is a flow chart of a method for installing the surge suppressor tank apparatus of FIG. 2 .
FIG. 4 a is a side view of an embodiment of a surge suppressor tank apparatus, in accordance with the present invention.
FIG. 4 b is a front sectional view of an embodiment of a surge suppressor tank apparatus, in accordance with the present invention.
FIG. 4 c is an exploded view of a portion of the surge suppressor tank apparatus of FIG. 4 a , in accordance with the present invention.
FIG. 5 is a side view of an embodiment of a surge suppressing pipe apparatus, in accordance with the present invention.
The foregoing summary, as well as the following detailed description of certain embodiments of the present invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, certain embodiments are shown in the drawings. It should be understood, however, that the present invention is not limited to the arrangements and instrumentality shown in the attached drawings.
DETAILED DESCRIPTION OF THE INVENTION
Certain embodiments of the invention may be found and/or used in a system and method for water surge protection. More specifically, certain embodiments relate to protecting a water distribution system from main breaks caused by sudden pressure spikes in the distribution system.
Referring to FIG. 1 , a small water distribution system, or a portion thereof, generally indicated at 10 , comprises a water tower 11 , a water reservoir or well 12 , a processing or pumping station 14 , a water main 18 and branch lines 20 which carry the water from main 18 . A plurality of valves, indicated by diagrammatic circles 22 , are located at various places in the distribution system and are used to shut off the flow of water along its distribution line. In addition, water outlets 26 , are also located at various places in the distribution system. Outlets 26 may take on a variety of forms including a fire hydrant. Water distribution systems such as 10 are conventional; they have many outlets such as 26 and cover a wide distribution area.
Referring to FIG. 2 , a surge suppressor apparatus 200 includes a surge suppressor tank 210 and tee pipe 231 . Surge suppressor tank 210 is cylindrical in shape and includes end caps 215 . Surge suppressor tank 210 and tee pipe 231 are manufactured as one piece. For example, surge suppressor tank 210 is welded to tee pipe 231 . Surge suppressor apparatus 200 may be formed of cast iron, ductile iron, or plastic (e.g., polyvinyl chloride), as well as other materials as will suggest itself.
Surge suppressor apparatus 200 is connectable to a branch line or supply pipe 240 using a coupler (not shown), or a standard clamp (not shown), or the like. The coupler or standard clamp may be formed of stainless steel, cast iron, ductile iron or plastic, among other things. Tee pipe 231 includes a base 230 which may be manufactured in varying diameters in order to match the particular diameter of supply pipe 240 where a main break occurs. For example, base 230 is manufactured from cylindrical pipe having a diameter of either 4, 6, 8, 10, or 12 inches. The branch section 220 of tee pipe 231 may also be formed of cylindrical pipe and vary in diameter. In one embodiment, the diameter of the base 230 of the tee pipe is the same diameter as branch section 220 .
Surge suppressor apparatus 200 is installed by cutting out and removing a section of the branch line or supply pipe 240 . The cut out section of supply pipe 240 may be at the location of a break in the pipe, for example, caused by sudden pressure spikes in the water distribution system. Couplers or standard clamps may be used to connect the ends 235 of the tee pipe 231 to the cut out ends 245 of supply line 240 . In one embodiment, surge suppressor apparatus 200 is installed so that surge suppressor tank 210 is vertically above supply line 240 .
Surge suppressor tank 210 is formed of a hollowed cylindrical container. The ends of suppressor tank 210 may be sealed by end caps 215 . End caps 215 may be welded, or otherwise securely attached to surge suppressor tank 210 to seal the tank. Suppressor tank 210 may have an opening 221 which leads to branch section 220 of the tee pipe. The horizontal length of surge suppressor tank 210 is approximately twice that of its diameter. Surge suppressor tank 210 provides a chamber of a predetermined volume which receives an increase in water volume during water surges.
Surge suppressor tank 210 is typically full of ambient air when the surge suppressor apparatus is installed. Air may be trapped within the surge suppressor tank 210 . The end caps 215 of the surge suppressor tank 210 maintain an airtight seal. When water flows into the surge suppressor apparatus 200 via supply pipe 240 and through the base 230 of the tee pipe at a greater pressure than ambient air pressure, the water level may rise up through the branch section 220 and into the surge suppressor tank 210 . The air within surge suppressor tank 210 may be compressed until pressure equilibrium occurs between the compressed air and the water flowing through base 230 of tee pipe 231 . At pressure equilibrium, the water level maintains a vertical height within surge suppressor tank 210 . In operation, upon a water surge, water is forced through branch section 220 of tee pipe 231 and into surge suppressor tank 210 against the compressed gas, compressing the gas even further. The surge suppressor tank thus serves as a shock absorber for the water surge.
In operation, one or more valves that are opened and/or closed rapidly may cause shockwaves of moving water through the water distribution system. If surge suppressor apparatus 200 were absent, the surge would act on, and possibly break or part, the mains within the water system. As will suggest itself, other surges can be caused by different flow characteristics in the line caused by pumps or other devices. After surge suppressor apparatus 200 is installed, however, the surge is diverted and arrested (or at least greatly attenuated) by surge suppressor tank 210 located above tee pipe 231 . When a surge occurs, water is driven upward through branch section 220 of the tee pipe 231 and into surge suppressor tank 210 . The air within surge suppressor tank 210 quickly compresses and then relaxes, absorbing the force of the surge.
FIG. 3 illustrates a flow chart of an exemplary method for installing a surge suppressor tank apparatus 200 , in accordance with an embodiment of the present invention.
First, at step 310 , the area surrounding a water release point in the water distribution system may be excavated. The water release point may be an area where a main break has already occurred, or the area may be chosen, in a preventive step, at a location so as to reduce the risk of future main breaks, among other things. Before excavating, water may need to be shut off using a shut-off valve (not shown) to stop water from passing through supply pipe 240 . Once the water is shut off, the area surrounding the water release point may be excavated by removing the overburden of soil, for example.
At step 320 , the section of supply pipe 240 is cut out and removed to provide an opening in the water distribution piping for receiving surge suppressor tank apparatus 200 . The section of supply pipe 240 which is removed may be the approximate horizontal width of the surge suppressor tank apparatus 200 . The section of supply pipe 240 that is cut out may be located where a main break has occurred or at the water release point, for example.
Next, at step 330 , surge suppressor apparatus 200 is installed. The appropriate surge suppressor apparatus 200 is chosen based on the material (e.g., stainless steel, cast iron, ductile iron, plastic, etc.) forming apparatus 200 . In addition, apparatus 200 is chosen based on the diameter of the supply pipe 240 . A cast iron surge suppressor apparatus 200 may be chosen if supply pipe 240 is cast iron. Additionally, the diameter of base 230 of tee pipe 231 may be the same diameter as that of supply pipe 240 .
In an embodiment, the ends 235 of the base 230 of tee pipe 231 are connected to the cut off ends 245 of supply pipe 240 by using standard clamps or couplers, or by welding together the joining ends 245 and ends 235 where the suppressor 200 is made from polyethylene, fusion welding of ends 245 , 235 could be used. As understood, cast iron, PVC asbestos pipe, etc. is impossible to weld to a dissimilar material of the supply pipe 240 . Surge suppressor apparatus 200 may be installed so that surge suppressor tank 210 is vertically above supply line 240 .
Next, at step 340 , the excavated area surrounding the installed surge suppressor apparatus is covered with soil. After filling in the excavated area, supply pipe 240 , that was previously shut off, may be opened to permit water flow there through. The system once pressurized again may then be inspected for leaks prior to backfilling.
Referring to FIGS. 4 a - 4 c , a surge suppressor apparatus 400 includes a surge suppressor tank 410 and tee pipe 417 . Tee pipe 417 includes a base 430 which may be manufactured in varying diameters in order to match the particular diameter of a supply pipe (e.g., supply pipe 240 , FIG. 2 ) where a main break occurs. For example, base 430 is manufactured from cylindrical pipe having a diameter of either 4, 6, 8, 10, or 12 inches. The branch section 420 of tee pipe 417 may also be formed of cylindrical pipe and vary in diameter. In an embodiment, the diameter of the base 430 of the tee pipe 417 is the same diameter as branch section 420 . In an embodiment, the diameter, as referred to above, is measured using the inside diameter of the cylindrical pipe. Of course, engineering specifications may be met as to sizing the suppressor 400 to adapt to the particular supply pipe.
Surge suppressor tank 410 is cylindrical in shape and includes circular end caps 415 . In certain embodiments, end caps 415 may be recessed from the outer ends of the cylindrical wall of tank 410 , as shown at 450 . For example, end caps 415 may be recessed 0.25 inches from the outer ends of tank 410 . Surge suppressor tank 410 includes six (6) cross braces 405 ( FIG. 4B ) to prevent end caps 415 from bowing. As will suggest itself, other means or structural members may be used to reinforce end caps 415 . Alternatively, tank 410 may be made similar to a conventional propane tank.
Surge suppressor tank 410 may include a test port 440 with an associated plug (not shown) for emptying the surge suppressor tank. For example, during a passavation process (citric acid bath) to coat the area of welds, the tank may be emptied. In another embodiment, port 440 may be used to test water/air ratios, among other things. However, the threaded connection between the port and plug must not allow air to escape. Surge suppressor apparatus 400 may be formed of stainless steel, for example. In addition, if apparatus 400 is made from carbon steel and an approved coating is used, the port and plug, and passavation are unnecessary.
Referring to FIG. 5 , a surge suppressing pipe apparatus 500 includes an inner pipe 510 and an outer pipe 520 . Inner pipe 510 includes multiple perforations 515 . In an embodiment, the multiple perforations may be of uniform size and/or shape, as for example, ¾ inch circular holes which permit water to pass between pipes 510 , 520 . Additionally, the multiple perforations may be uniformly placed on the inner pipe 510 .
Outer pipe 520 is of a larger diameter and surrounds inner pipe 510 . Pipe 520 is attached to inner pipe 510 via tapered ends 517 of outer pipe 520 . The surge suppressing pipe apparatus 500 may be manufactured in varying diameters in order to match the diameter of inner pipe 510 to the diameter of a supply pipe (e.g., supply pipe 240 , FIG. 2 ) where a main break occurs. For example, inner pipe 510 is manufactured from cylindrical pipe having a diameter of either 4, 6, 8, 10, or 12 inches. The outer pipe 520 may also be formed of cylindrical pipe and vary in diameter. For example, if the supply pipe where a main break occurs is 6 inches, a surge suppressing pipe apparatus 500 having an inner pipe 510 diameter of 6 inches and an outer pipe 520 diameter of 8 inches may be used. In an embodiment, the surge suppressing pipe apparatus is manufactured as one piece. In an embodiment, the diameter is measured using the inside diameter of the cylindrical pipe.
The attachment of the outer pipe 520 to the inner pipe 510 forms a seal. For example, outer pipe 520 may be welded to inner pipe 510 .
Outer pipe 520 is filled with batting material for suppressing surges forces that occur from water passing through perforations 515 of the inner pipe. In an embodiment, the batting material may be closed cell foam plastic. Alternatively, a layer of foam may be applied between pipes 510 , 520 . In addition, air or another gas may fill a bladder that is disposed between pipes 510 , 520 . Also, the portion of inner pipe 510 may be eliminated and batting material or other suppressing material may be secured to the inside wall of pipe 520 , as for example, where the pipes are made from polyethylene. Where the batting material is placed throughout the space between pipes 510 , 520 , the suppressing effect on surges will be more effective.
The ends of the inner pipe 510 extend beyond the tapered sealing attachment of the outer pipe 520 onto the inner pipe 510 . For example, the ends of the inner pipe 510 may extend at least 4 inches beyond the attachment point 519 of the outer pipe 520 onto the inner pipe 510 to allow space for attaching the surge suppressing pipe apparatus 500 to a supply pipe (e.g., supply pipe 240 ). Surge suppressing pipe apparatus 500 may be formed of stainless steel, cast iron, ductile iron, or plastic (e.g., polyvinyl chloride), as well as other materials as will suggest itself.
In operation, one or more valves that are opened and/or closed rapidly may cause shockwaves of moving water through the water distribution system. If surge suppressing pipe apparatus 500 were absent, the surge would act on, and possibly break or part, the mains within the water system. As will suggest itself, other surges can be caused by different flow characteristics in the line caused by pumps or other devices. After surge suppressing pipe apparatus 500 is installed, however, the surge is diverted and arrested (or at least greatly attenuated) by the matted outer pipe 520 surrounding the perforated inner pipe 510 . When a surge occurs, water is driven upward through perforations 515 of the inner pipe 510 and into matted outer pipe 520 . The matting within outer pipe 520 quickly compresses and then relaxes, absorbing the force of the surge.
Thus, certain embodiments provide for a system and method for protecting a water distribution system from main breaks caused by sudden pressure spikes in the distribution system using a surge suppressor apparatus and/or a surge suppressing pipe apparatus. By using one or more of the surge suppressing apparatuses, municipalities may save time and money that may be spent fixing future main breaks. Certain embodiments provide for a cost efficient system and method for water surge protection.
While the present invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiment disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.
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A method and apparatus protecting a water distribution system from main breaks caused by sudden pressure spikes in the distribution system. A surge suppressor apparatus may include a surge suppressor tank. The surge suppressor tank may be a hollow, cylindrical container adapted to retain liquid. The surge suppressor apparatus may also include a tee pipe integrally formed to the suppressor tank. The tee pipe is sized so that it connects to an underground supply pipe. End caps may be integrally formed to the suppressor tank. The end caps create an airtight seal in the surge suppressor tank.
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FIELD OF THE INVENTION
[0001] The present invention pertains to the technical field of efficiency enhancing of an internal combustion engine, and relates to a method for optimizing exhaust backpressure of an internal combustion engine. The present invention further relates to an apparatus and system for optimizing exhaust backpressure of an internal combustion engine.
DESCRIPTION OF THE PRIOR ART
[0002] In this century, the world's oil resources insufficiency and environmental pollution problems have become increasingly prominent, and there is the need to further improve the economy of the internal combustion engine and exhaust cleaning. The energy efficiency of the internal combustion engine, i.e. fuel efficiency also needs to be further improved, which is the basis and prerequisite of all facilities and equipment powered by internal combustion engines to enhance energy efficiency.
[0003] At present, the main way to increase the energy efficiency of internal combustion engine is to improve the ventilation effect, i.e. intake and exhaust process, of the internal combustion engine. The way of improving intake is ‘pressure boost’, i.e. to increase the intake pressure; the way of improving exhaust is ‘depressurization’, i.e. to reduce the exhaust backpressure, that is, to reduce the resistance of the exhaust. ‘Pressure boost’ and ‘depressurization’, the two complement each other.
[0004] The pressure boost technology developed at the beginning of last century dramatically improves the performances of the power, economy and emission of the internal combustion engine, which has become an important symbol of the internal combustion engine development. Pressure boost model has become the basic model of the internal combustion engine, and in particular, the turbine pressure boost technology that uses the internal combustion engine exhaust gas to drive a turbine, and then a compressor is driven by a turbine to ‘pressure boost’ intake air of an internal combustion engine, and the intercooling technology that is combined with intake air pressure boost, have now developed into a near-perfect and are widely used. But the disadvantage is: the acceleration performance of the internal combustion engine is limited due to the internal combustion engine being sensitive to exhaust backpressure.
[0005] The so-called ‘depressurization’ is to reduce the exhaust backpressure, and the exhaust backpressure is related to the exhaust resistance of the internal combustion engine. With the increase of the load when the engine operates, the mass of the exhaust gas and the temperature of the exhaust gas are also increased. With the double impact of the mass and temperature of the exhaust gas, the volume flow and the flow rate of the exhaust increase even larger, so that the resistance of the exhaust passage, including the resistance of the other components (e.g., a muffler) in the exhaust passage, rises rapidly due to the law of positive pressure being proportional to the square of flow rate. Therefore, the internal combustion engine backpressure also increases rapidly with the engine load. High backpressure means that the exhaust gas flow is encountered with a large resistance, such that the exhaust within the cylinder is difficult to discharge cleanly, thus affecting subsequent combustion quality. Therefore, the exhaust backpressure affects the performance of an internal combustion engine. The increase of the backpressure will lead to decrease of the combustion efficiency, economy and emission performance of the internal combustion engine, and in the meantime the power performance decreases and fuel consumption increases. Data shows that this will cause at least more than 10% loss of energy efficiency to the internal combustion engine. Especially for a turbocharged internal combustion engine rotating at high speed relying on an exhaust gas driven turbine, the increase of the exhaust backpressure leads to a decrease of the pressure drop of the exhaust gas which drives the turbine, causing a decrease of the effect of turbocharging, which in turn makes the intake pressure reduced, so as to result in a further decrease of the energy efficiency of the internal combustion engine. What is even more serious is that, with countries being increasingly strict on international environmental regulations, the requirements for the internal combustion engine exhaust gas treatment are also increasingly higher.
[0006] As the backpressure of a system is the sum of the pressure drops formed by the airflow sequentially passes through each of the elements in the system, and the pressure drop formed by passing through each element is proportional to the square of the flow rate of the airflow passing through. Accordingly, after the installation of the exhaust processing devices and apparatus for muffling, purification or even waste heat recovery for an internal combustion engine, the engine exhaust backpressure is greatly increased, the energy efficiency of an internal combustion engine is reduced, and energy consumption is increased. The rise of the internal combustion engine energy consumption means more fossil fuel consumption, resulting in more pollution, which in turn results in reducing the effects of the environmental protection and energy-saving measures taken earlier.
[0007] So, while people are continuously developing the ‘pressure boost’ technology, they are also seeking for technology of ‘depressurization’, such as the multi-valve technology which enlarges the exhaust gas flow space by using multiple exhaust valves, so that the exhaust backpressure is reduced. For some special competitive occasions, such as racing, the power of an internal combustion engine is required to give full play, even without installing a muffler aiming to reduce backpressure as much as possible.
[0008] However, in a situation where the internal combustion engine is under low load, if the exhaust backpressure is very low, due to the exhaust valve being opened in advance, the fuel gas still having certain pressure will be discharged from the excessively clear exhaust valve before the piston reaches the bottom stop point, such that a portion of power is lost and the torque is reduced. It can be seen that keeping up a certain exhaust backpressure when the internal combustion engine is under low load will instead increase the torque.
[0009] In summary, for the backpressure of an internal combustion engine, it is desired that the backpressure is not too low when the internal combustion engine is under low load, and however, it is desired that the exhaust backpressure is restrained to the greatest extent from increasing too rapidly. Only then the efficiency improvement of the internal combustion engine can only be realized under all working conditions thereof
SUMMARY OF THE INVENTION
[0010] In view of the existing desires for the exhaust backpressure of an internal combustion engine, the present invention provides a new method, a new apparatus and a new system for optimizing exhaust backpressure of an internal combustion engine. The present invention is based upon the principle: If the exhaust gas of an internal combustion engine is rapidly cooled, the exhaust backpressure can be greatly reduced. So, when the internal combustion engine is under low load, a certain amount of exhaust resistance is arranged such that the backpressure will not go so far as to be too low; when the internal combustion engine is under high load, the exhaust gas is rapidly cooled so that the backpressure will not go so far as to rise too rapidly.
[0011] A first object of the present invention is to provide a method for optimizing exhaust backpressure of an internal combustion engine, comprising:
1) providing a damping member in an exhaust passage of an internal combustion engine, and making an exhaust gas discharged from an internal combustion engine passing through said damping member; 2) cooling the exhaust gas before passing through said damping member, or cooling the exhaust gas while passing through said damping member.
[0014] By utilizing the method provided by the present invention the following can be achieved: a relatively higher exhaust backpressure when the internal combustion engine is under low load, and the exhaust backpressure will not rise too fast when the internal combustion engine is under high load. Specifically, allowing the exhaust gas discharged by the internal combustion engine to pass through a damping member that is capable of providing a certain amount of exhaust resistance produces a desired relatively high exhaust backpressure, so as to increase the torque of the internal combustion engine when it is under low load. The exhaust gas being rapidly cooled before or when it passes through the damping member can achieve the purpose of increasing gas density of the exhaust gas and decreasing the flow rate of the exhaust gas. The backpressure is restrained from rising to fast when the internal combustion engine is under intermediate, high load, so as to improve the efficiency of the internal combustion engine.
[0015] The present invention also provides an apparatus for optimizing exhaust backpressure of an internal combustion engine, comprising:
1) a housing; 2) an exhaust gas inlet provided on the housing allowing an exhaust gas to enter into an interior of the housing, an exhaust gas outlet provided thereon allowing an exhaust gas to be discharged out of the housing; 3) a damping member provided in the interior of the housing or on the housing; 4) a cooling member provided in the interior of the housing for cooling an exhaust gas.
[0020] Based on the above principle, mounting the apparatus provided by the present invention in the exhaust passage can not only provide a certain amount of exhaust resistance when the internal combustion engine is under low load, but also makes the exhaust backpressure not rise too fast when the internal combustion engine is under high load. Especially when the existing members having resistance, such as mufflers, in the exhaust passage is replaced with the apparatus of the present invention, the overall performance of the exhaust system can be preferably improved.
[0021] The present invention also provides another apparatus for optimizing exhaust backpressure of an internal combustion engine, comprising:
1) a housing; 2) an exhaust gas inlet provided on the housing allowing an exhaust gas to enter into an interior of the housing, an exhaust gas outlet provided thereon allowing a exhaust gas to be discharged out of the housing; 3) a damping member provided in the interior of the housing or on the housing; 4) a cooling water inlet provided on the housing allowing cooling water to enter into the housing, a cooling water outlet provided thereon allowing cooling water to be discharged out of the housing; said cooling water inlet, cooling water outlet, exhaust gas inlet and exhaust gas outlet configured so that cooling water and exhaust gas able to come in to contact with each other in an interior of the housing.
[0027] Similarly, installing the apparatus in the exhaust passage can also achieve the purpose of optimizing exhaust backpressure of an internal combustion engine.
[0028] The present invention also provides a system for optimizing exhaust backpressure of an internal combustion engine, comprising an exhaust passage of an internal combustion engine, wherein said system further comprises an apparatus for optimizing exhaust backpressure of an internal combustion engine provided by the present invention, which is mounted in said exhaust passage of an internal combustion engine. Based on the same principle, the present invention provides a system that can achieve the purpose of optimizing exhaust backpressure of an internal combustion engine.
[0029] Utilizing the method, apparatus and system provided by the present invention can simply and efficiently enhance the power of an internal combustion engine, reduce fuel consumption and enhance the specific power of an internal combustion engine, and can be applied to various devices using internal combustion engine as the power.
[0030] The first principle of the present invention is: set a certain amount of exhaust resistance, so that an internal combustion engine has a desired, relatively high exhaust backpressure when under low load.
[0031] The scheme to achieve its purpose is: to provide a damping member in the exhaust passage of an internal combustion engine, and allow the exhaust gas discharged from the internal combustion engine to pass through said damping member.
[0032] Here, the damping member is a member that can provide a certain amount of exhaust resistance, that is, the pressure drop produced before and after exhaust gas passing through the damping member is a desired pressure drop. Forms of the damping member may include: 1) reducing the cross-section of the exhaust passage of the internal combustion engine, or 2) dividing the exhaust gas into small tributaries, or 3) changing the flow direction of the exhaust gas, or 4) other forms that can provide a certain amount of exhaust resistance, or 5) a combination of the above forms.
[0033] The damping member is a member that can reduce the cross-section of the exhaust passage, such as an exhaust pipe with abruptly reduced cross-sections, or a member provided in the exhaust pipe and having pores. It can be provided to abruptly reduce the cross-section of the exhaust passage of an internal combustion engine, so as to provide a certain amount of exhaust resistance. Such as, providing a baffle with pore in the exhaust pipe of an internal combustion engine, such that the exhaust gas can only pass through the pores. It also can be provided such that the exhaust pipe of an internal combustion engine abruptly becomes thinner. In addition, the larger the extent to which the cross-section reduces, the larger the exhaust resistance.
[0034] The damping member may also be a member that can divide the exhaust gas into a plurality of tributaries. Here, the way of the noted ‘divide the exhaust gas into a plurality of tributaries’ may be making the exhaust gas pass through a structure with a plurality of distributed pores, and the exhaust gas is thus dispersed by the pores. The way used may also be making the exhaust gas pass through a structure with a plurality of gaps, and the exhaust gas is thus dispersed by the gaps. By the method of dividing the exhaust gas into small tributaries, a certain amount of exhaust resistance can also be provided. In the method, the degree of the exhaust gas being divided can be adjusted depending on the desired exhaust backpressure: the more the number of small tributaries into which the exhaust gas is divided, the thinner the divided small tributaries, and the greater the exhaust resistance; vice versa.
[0035] The damping member may also be an exhaust pipe that can change the flow direction of the exhaust gas. A certain amount of exhaust resistance can also be provided if the flow direction of the exhaust gas is changed, such as by having a plurality of curved exhaust pipes.
[0036] The damping member referred to in the present invention can also be provided in the interior of a housing, and cools the exhaust gas discharged by the internal combustion engine in the interior of the housing. So, the method provided by the present invention can also include: making the exhaust gas discharged by the internal combustion engine enter into the interior of the housing through an exhaust gas inlet on the housing, then discharge the cooled exhaust gas out of the housing through an exhaust gas outlet on the housing. The damping member may be located in the interior of the housing, such as by providing a pore plate or padding with a large number of gaps in the interior of the housing. In addition, the damping member may also be located on the housing, such as an abrupt reducing of cross-sections existing from the interior of the housing to the exhaust gas outlet on the housing.
[0037] Another principle of the present invention is: the high-temperature exhaust gas of an internal combustion engine being rapidly cooled may greatly reduce the flow rate of the exhaust gas, so that the exhaust backpressure will not rise too fast when the internal combustion engine is under high load.
[0038] It is known in the prior art that: the existing structure of the exhaust passage of the internal combustion engine having a certain amount of exhaust resistance (e.g., an exhaust pipe, muffler, etc.), as the load of the internal combustion engine increases, the gas displacement and the exhaust temperature will rise with it, so that the flow rate rises, and due to the positive pressure, i.e. the resistance being proportional to the square of the flow rate, the exhaust backpressure is thus caused to rise rapidly.
[0039] The applicant has found that before or when the exhaust gas is encountered with a certain amount of resistance, the exhaust backpressure may be reduced if the exhaust gas temperature can be rapidly lowered, thereby improving the efficiency of the internal combustion engine.
[0040] The scheme of rapidly reducing the temperature of the exhaust gas may be: 1) making the exhaust gas and the cooling liquid come into contact with each other; or 2) dividing the exhaust gas into a plurality of small tributaries, and then making the dispersed small tributaries heat exchange with the cooling medium, or 3) a combination of the above two.
[0041] If the high-temperature exhaust gas is made to come into direct contact with a cooling liquid such as cooling water, the purpose of rapid cooling can be achieved. A preferable way is to keep the cooling water flowing, such as the use of spray, discharging the cooling water which has absorbed heat, and the exhaust gas continuously contacting the new cooling water, thus the cooling effect will be better.
[0042] Here, the cooling water source can be determined based on the specific circumstances.
[0043] The cooling water used as the cooling fluid may come from an external independent water system of the immediate natural environment, for example, taken from the natural water body such as seawater or inland freshwater naturally existing. As to the apparatus (such as vessels) that use the internal combustion engine as the power on the ocean or freshwater, the cooling water may be directly extracted from the seawater or freshwater of the immediate nature environment, or, the seawater or freshwater may be firstly stored in a water storing apparatus such as water tank, water tower, the cooling water is obtained from the water storing apparatus. The cooling water which has absorbed heat may be directly discharged to the immediate natural environment; also the cooling water which has absorbed heat may be processed before being discharged to the immediate natural environment. Thus, the method provided by the present invention also includes: extracting cooling water from a natural water body and convey it to the housing. The system provided by the present invention also includes an apparatus, such as a cooling water intake pipe installed with a pump, which is able to extract cooling water from a natural water body and convey it to the housing, the cooling water intake pipe communicating with the cooling water inlet of the housing.
[0044] The cooling water of the internal combustion engine may also be reused to be used as the cooling water for cooling the liquid. Most apparatus that uses internal combustion engine as the power, such as vehicles, vessels, etc., per se, have a set of cooling water system of internal combustion engine. In this case, the cooling water may be taken from the cooling water system of the power apparatus itself. Therefore, the method provided by the present invention also includes conveying the cooling water of an internal combustion engine to a housing. The system provided by the present invention also includes an apparatus that is able to convey the cooling water of an internal combustion engine to a housing.
[0045] The cooling water used as the cooling liquid may be used combining the above two methods, both using the cooling water from a natural water body and using the cooling water of the internal combustion engine.
[0046] The cooling water used as the cooling liquid may also be recycled. The cooling water discharged from the housing, which has absorbed heat of the high-temperature exhaust gas, may be directly discharge out or discharged after being processed, and may also be recycled. For example, the cooling water absorbing heat after cooling the high-temperature exhaust gas may flow through a heat exchanger, being cooled before entering the housing again as the cooling water.
[0047] The cooling water may be allowed to come into contact with the exhaust gas of an internal combustion engine in an interior of a housing, thereby achieving the purpose of rapidly reducing the temperature of the exhaust gas. Therefore, the method provided by the present invention may also include: making the cooling liquid enter into the interior of the housing through the cooling water inlet of the housing, and discharging the cooling liquid which has absorbed heat from the exhaust gas out of the housing through the cooling water outlet of the housing.
[0048] The exhaust gas of the internal combustion engine may be allowed to enter from the exhaust gas inlet on a housing, and be discharged from the exhaust gas outlet, forming an exhaust gas flow path. In addition, the cooling water may be allowed to enter from the cooling water inlet of the housing, and be discharged from the cooling water outlet, forming a cooling water flow path. The exhaust gas inlet abovementioned refers to any opening that allows fluid enter into the interior of the housing, which may be a direct opening on the wall of the housing, then, through a connecting member, communicates with the pipe for conveying liquid. The housing may also be integrally molded with the conveying pipe. The conveying pipe may also extend into the interior of the housing, so that, the exhaust gas inlet refers to the pipe orifice extending into the interior of the housing. The cooling water inlet, cooling water outlet and the exhaust gas outlet may also use the various forms as abovementioned.
[0049] The housing used by the present invention is a closed housing, that is, except the positions of abovementioned exhaust gas inlet, exhaust gas outlet, cooling water inlet, cooling water outlet, the other parts are all sealed, and the gas or liquid entering the housing can only enter and exit from the abovementioned inlets and outlets.
[0050] In order to achieve the purpose of rapid cooling of the exhaust gas, in the method and apparatus provided by the present invention, the exhaust gas of an internal combustion engine and the cooling water are required to come into contact with each other, that is, the flow path of the exhaust gas of the internal combustion engine and the flow path of the cooling water are made to overlap with each other.
[0051] If a more optimal cooling effect is desired, one preferred embodiment is to make the exhaust gas of the internal combustion engine and the cooling water to contact reversely or/and laterally, that is, the flow direction of the exhaust gas and the flow direction of the cooling water are away from each other or facing each other, or nearly away from each other or facing each other. If the cooling water inlet is made to be located downstream of the exhaust gas flow, and the cooling water outlet is located upstream of the exhaust gas flow, the cooling water and exhaust gas thereby may reversely contact, such that the contact is more adequate. Therefore, in a preferred embodiment, the exhaust gas of the internal combustion engine and the cooling water reversely contact. In a more preferred embodiment, the exhaust gas of the internal combustion engine pass through the interior of the housing from bottom to top, and the cooling water pass through the interior of the housing from top to bottom, allowing them to reversely contact. The advantage thereof is that the exhaust gas of the internal combustion engine may disperse in the interior of the housing more adequately, and the cooling water may flow by fully utilizing the gravity effect, other than applying extra pressure to maintain its flowing. Thus, the cooling water inlet may be configured to be higher than the cooling water outlet in the gravity direction, so that the cooling water entering the housing through the cooling water inlet passes through the interior of the housing from top to bottom; the exhaust gas inlet is lower than the exhaust gas outlet in the gravity direction, so that the exhaust gas entering the housing through the exhaust gas inlet passes through the interior of the housing from bottom to top. Thus, the cooling water and the exhaust gas may reversely contact, thereby the contact is more adequate.
[0052] In order to further enhance the full contact of the cooling water and the exhaust gas, one can think of ways to improve the degree of dispersion of the cooling water entering the housing. For instance, one or more water distributor composed of spraying member with a plurality of pores, arranged uniformly on the upper side of the interior of the housing, spraying the cooling water onto the entire interior of the housing to the best of it, so that the cross-section of the housing can be uniformly distributed with water. Thus, the method provided by the present invention also includes: dispersing the cooling water entering the interior of the housing. The housing of the apparatus provided by the present invention is also provided with a member dispersing the cooling water entering into the interior of the housing, such as a water distributor.
[0053] In a more preferred embodiment, in order to not allow the cooling water from entering the exhaust pipe of the internal combustion engine from the exhaust gas inlet, the cooling water outlet may be configured to be lower than the exhaust gas inlet in the gravity direction. Thus, before the liquid surface of the cooling water flowing to or falling onto the bottom of the housing reaches the position of the exhaust gas inlet, the cooling water is already discharged from the cooling water outlet.
[0054] In addition, the bottom of the casing may also be provided with a water seal, making the liquid surface of the cooling water higher than the cooling water outlet and lower than the exhaust gas inlet. Thus, the exhaust gas will not flow out from the cooling water outlet. Further, providing a water seal makes the cooling water not enter the exhaust gas inlet, even if the angle of inclination of the water seal liquid surface in all direction reaches 22.5 °.
[0055] In a more preferred embodiment, the exhaust gas inlet is located on the lower portion of the side surface of the housing, and the exhaust gas outlet is located at the top of the housing, and the exhaust gas outlet may connect directly to the chimney, discharging directly the exhaust gas into the atmosphere. The cooling water inlet is located on the upper portion of the side surface of the housing, and the cooling water outlet is located on the lower portion of the side surface. Moreover, in the gravity direction, the cooling water outlet is lower than the exhaust gas inlet. In a most preferred embodiment, the exhaust gas inlet is located at the bottom of the housing, and the exhaust gas outlet is located at the top of the housing, so that the exhaust gas inlet may connect directly to the exhaust pipe of the internal combustion engine, and the exhaust gas outlet connects directly to the chimney, discharging the exhaust gas directly into the atmosphere.
[0056] If the exhaust gas is divided into small tributaries, and then the dispersed small tributaries heat exchange with a cooling medium, so that the efficiency of heat exchange between the exhaust gas and the cooling medium can be greatly improved, thereby achieving the purpose of rapidly reducing the exhaust temperature, so that the exhaust backpressure will not rise too face when the internal combustion engine is under high load. Another effect of cooling the exhaust gas in this way is: such that the exhaust backpressure will not be too low when the internal combustion engine is under low load, thereby achieving the effect of optimizing the exhaust backpressure under all working conditions.
[0057] Here, the way of the abovementioned ‘dividing the exhaust gas into small tributaries’ may be making the exhaust gas pass through a structure with pores distributed therein, and the exhaust gas is thus dispersed by the pores. The way used may also be making the exhaust gas pass through a structure having gaps, such as a heat dissipating sheet, and the exhaust gas is thus dissipated by gaps.
[0058] Here, the cooling medium may be gases having endothermic properties, such as air, hydrogen, etc. Then the cooling medium may be made to come into contact with the exhaust gas, which is divided into small tributaries, through the cooling member, so that the exhaust gas is cooled. The cooling member may be a heat dissipating sheet or radiator made of materials having good heat transfer properties, such as a metal material. A part of the cooling member is located in the housing, and a part outside the housing, being able to rapidly transfer the heat of the exhaust gas in the housing to the outside of the housing to be released. In this case, the process of heat exchange between the exhaust gas and the cooling member is at the same time the process of the exhaust gas being divided into small tributaries. Here, the cooling medium may also be in the form of a combination of cooling member and fluid, such as the flowing cooling water being encapsulated in a metal pipe, which can also achieve the purpose of rapid cooling. The benefit of doing so is that the cooling water in the pipe may generate vapor, the heat of which may be conveniently and directly utilized. For example, heat exchange is performed between a heat exchanger of tubular, plate, tube-wall or finned tube, and the exhaust gas. Similarly, when the high-temperature exhaust gas passes through the heat exchanger, it is divided into small tributaries to then perform heat exchange with the heat exchanger as well.
[0059] As described above, when the internal combustion engine is under high load, the backpressure is desired to be as low as possible. While in the prior art, the exhaust resistance of the structure (such as a muffler) provided in the exhaust passage of the internal combustion engine is relatively small. Therefore, in the case of the internal combustion engine being under low load, the desired exhaust backpressure cannot be achieved. In this way, the process of dividing the exhaust gas into small tributaries is also the process of providing a certain amount of exhaust resistance. The degree of the exhaust gas being divided can be adjusted depending on the desired exhaust backpressure. The more the small tributaries of the exhaust gas divided, the thinner the small tributaries divided, the greater the exhaust resistance; vice versa.
[0060] Accordingly, in this way, the purpose of optimizing exhaust backpressure of an internal combustion engine under all working conditions can be realized.
[0061] For the cooling of the exhaust gas, the most preferred way is to divide the exhaust gas into small tributaries, which is then cooled by way of making which and the cooling liquid (such as cooling water) come into contact with each other. For example, the exhaust gas is made to pass through a member having a large amount of gaps, to be divided into a plurality of small tributaries which in said gaps come into contact with the cooling liquid. In a preferred embodiment of the present invention, the housing is filled with padding which form gaps thereinbetween, thereby forming a padding layer having a large number of gaps which is a member which can divide the exhaust gas into a plurality of small tributaries, i.e. the damping member. Padding containing gaps thereby having a large specific surface area may be included in the housing, for the purpose that a large number of pores are formed in at least a part of the space inside the housing. Thus, the cooling fluid has to be dispersed when passing through the pores between the padding, in which the cooling fluid and the exhaust gas may fully contact. When the cooling liquid is cooling water, the form of padding may be selected to be the common bulk padding as Pall rings, Raschig rings or other saddle rings, also may be selected to be a common structured padding. The padding texture is preferred to be weatherproof materials like metal, ceramics, etc., and also can be selected to be polymer materials, such as polypropylene, polyethylene, or ABS engineering plastics, etc., or there kinds of materials may be used in combination. The high-temperature exhaust gas is divided into small tributaries when passing through this padding having a large specific surface area, preferably making the cooling liquid like cooling water come into direct contact with the high-temperature exhaust gas in said padding, allowing the high-temperature exhaust gas to be cooling rapidly. Therefore, in the method and apparatus provided by the present invention, the housing is filled with padding which can form gaps thereinbetween, forming a padding layer with a large number of gaps. The method provided by the present invention also includes: the exhaust gas is made to pass through a padding layer having a large number of gaps.
[0062] In addition, if the cooling fluid is selected to be cooling gas, such as air, the purpose of rapid cooling may also be achieved. In this case, the padding is preferably selected to be ceramic, enamel and metal materials, and these kinds of materials may be used in combination.
[0063] The method or apparatus provided by the present invention is specially suited for a turbocharged internal combustion engine, where the exhaust gas discharged by the internal combustion engine passes through a turbocharger impeller and works, before entering the housing from the gas inlet of the housing. Accordingly, the method provided by the present invention also includes: the exhaust gas discharged by the internal combustion engine passes through the turbocharger impeller and works before entering the housing. The exhaust passage of the internal combustion engine of the system provided by the present invention may be an exhaust passage of high-temperature exhaust gas, which is connected to the exhaust outlet at the exhaust gas side of the turbocharger.
[0064] Further, as the exhaust passage of current internal combustion engine is normally provided with one or more of a muffler, exhaust gas purification and waste heat recycling apparatus or devices. If these apparatus are arranged in the exhaust passage of the internal combustion engine, a certain amount of exhaust resistance will be provided, providing pressure drop in the exhaust path of the exhaust gas, and these apparatus are the apparatus that can make exhaust gas discharge produce a pressure drop. The more the pressure drop is, the greater the exhaust resistance is, leading to a higher exhaust backpressure.
[0065] According to the apparatus or devices through which the exhaust gas of the internal combustion engine passes before eventually discharged into the atmosphere, and to the different order of passing through these apparatus or devices, the method of the present invention has at least the following several applications: that is, the present method is applied before or after the exhaust gas passing through the above apparatus or devices, or the apparatus for optimizing backpressure according to the present invention is made to achieve the functions of the above apparatus or devices at the same time of optimizing backpressure, so as to replace the above apparatus or devices.
[0066] Thus, the system provided by the present invention may possibly has several ways described as follows, wherein, for convenience of description, in the following content, P 0 is set to be the external atmospheric pressure. In addition, the pressure drop caused by the resistance of the exhaust pipe is ignored, and pressure drop ΔP is used to represent the local pressure drops of one or more other exhaust gas treatment apparatus and devices. As the gas flow passes through the damping member is the apparatus of the present invention, the cooling apparatus per se will bring in a pressure drop ΔP i . Here it should be noted that, when the load of the internal combustion engine rises, the flow rate were to be increased rapidly, but due to the high-temperature exhaust gas being cooled rapidly with increased density and decreased volume, the flow rate thereby is lowered rapidly. Thus, in the case of a relative high-temperature exhaust, the rising range of ΔP i is small when the load of the internal combustion engine is increasing. In this case, as the flow rate is an exponential relationship with the positive pressure, the positive pressure or resistance caused by the decrease of the flow rate is still decreasing, even taking into consideration of the factor of the increase brought to the positive pressure by the increase of the exhaust gas density.
[0067] When there is no other exhaust gas treatment apparatus and device in the exhaust pipe, the exhaust backpressure of the internal combustion engine then is approximately to be the sum of the external atmospheric pressure P 0 and the pressure drop ΔP i of the cooling apparatus per se, i.e.:
[0000]
P=P
0
+ΔP
i
[0068] Thus, when the internal combustion engine is under low load, due to the presence of ΔP i , the torque of the internal combustion engine may be improved. When the load of the internal combustion engine is increasing, as described above, the rising range of ΔP i is small, so the influence on the backpressure P is limited.
[0069] If the exhaust passage is also installed with other apparatus therein which increases the exhaust backpressure, such as a muffler, and is located downstream of the apparatus provided by the present invention, then, the exhaust gas discharged by the internal combustion engine firstly passes through the apparatus provided by the present invention, and then through other apparatus or device for exhaust gas treatment, and after that, passes through the pipe and is discharged into the atmosphere. The exhaust backpressure P is approximately equal to the sum of external atmospheric pressure P 0 and pressure drop ΔP i of the apparatus per se of the present invention and other apparatus or device for exhaust gas treatment, i.e.:
[0000]
P=P
0
+ΔP+ΔP
i
[0070] Although, in comparison with the case in which the apparatus of the present invention is not used, the newly introduced apparatus of the present invention produces a pressure drop ΔP i , but as the high-temperature exhaust gas when the internal combustion engine is under intermediate and high load is rapidly cooled when passing through the apparatus of the present invention, so that the flow rate is largely decreased. As the pressure drop is proportional to the square of the flow rate, so the pressure drop ΔP when the cooled exhaust gas flow passes through the above described other apparatus or device for exhaust gas treatment is largely decreased in comparison with that when the high-temperature exhaust gas passes through, thereby improving the efficiency of the internal combustion engine. Moreover, in this case, as described above, when the internal combustion engine is under low load, the effect of improving the torque of the internal combustion engine exists, similarly.
[0071] According to the above description, if there is other apparatus for exhaust gas treatment installed in the exhaust passage, the exhaust backpressure will be adversely affected. However, in some cases, for environmental or other objects, it is necessary to install an apparatus for exhaust gas treatment, such as a muffler, in the exhaust passage. Therefore, if multiple functions can be integrated by the apparatus provided by the present invention, for instance, the apparatus is made to simultaneously have the muffling function, thereby the exhaust backpressure can be further optimized.
[0072] When other apparatus or device for exhaust gas treatment can be omitted if their functions are integrated with the apparatus of the present invention, this case is similar to the case in which the apparatus of the present invention is separately installed. Then, the exhaust backpressure of the internal combustion engine is approximately equal to the sum of external atmospheric pressure P 0 and the pressure drop ΔP i of the apparatus per se of the present invention, i.e.:
[0000]
P=P
0
+ΔP
i
[0073] This means that the pressure drop ΔP brought by other apparatus or device for exhaust gas treatment can be eliminated, and the exhaust backpressure is greatly decreased relative to the original situation, thereby improving the efficiency of the internal combustion engine. Similarly, due to the existence of ΔP i , the torque when the internal combustion engine is under low load is increased. Thus it can be seen that a more preferred scheme is that the apparatus of the present invention can integrate the functions of other apparatus or device for exhaust gas treatment, and then to replace these apparatus or devices for exhaust gas treatment. This replacement is precious for spatial resource, for instance, very important for a floating platform like vessel, etc., equipped with a muffler and a waste heat boiler.
[0074] It should be noted that, from the above description, it can be seen that the principle of the cooling apparatus integrating the waste heat recycling of the waste heat boiler lies in the recycling of the heat absorbed after the heat exchange between the cooling fluid and the high-temperature exhaust gas. The principle of integrating the muffling function of the muffler lies in that the effects of the exhaust gas, passing through the apparatus of the present invention, being divided by cross-section expansion and gas flow alteration, the two of which are theoretically and realistically not contradictory. Therefore, the cooling apparatus of the present invention may simultaneously integrate the functions of waste heat recycling and muffling.
[0075] In order to prevent noise pollution, at present, the exhaust passage of the internal combustion engine is generally mounted with the muffler, which is also a main member causing the rise of the exhaust backpressure of the internal combustion engine. The applicant has found that, if the exhaust gas entering the housing can be rapidly cooled, the function of enhancing the muffling effect can be realized.
[0076] Based on the muffling principle, there are different types of mufflers like resistive muffler, reactive muffler and impedance composite muffler. A resistive muffler mainly uses porous sound-absorbing materials to reduce noises. When sound waves enter the resistive muffler, part of the sound energy is turned into heat by friction in the pores of the porous material to be dissipated, making the sound wave passing through the muffler be weakened. A resistive muffler has good effect on intermediate and high frequency, and poor effect on low frequency. A reactive muffler is combined from chambers and ducts with abrupt interfaces, making use of abrupt expansion or contraction of the cross-section of the pipe to reflect back the sound waves of certain frequencies transmitting along the pipe at the position of sudden change to the direction of the sound source, so as to achieve the purpose of muffling. The reactive muffler is suitable for eliminating noise of low-to-intermediate frequency, and is poor for high-frequency noise. Combining the resistive structure and reactive structure in a certain manner, an impedance composite muffler is formed, which has muffling characteristics of both.
[0077] In order to achieve good muffling effect, the following schemes have been found which facilitate enhancing the muffling effect: 1) multiple changes in the direction of air flow, 2) the air flow repeatedly passing through cross-sections first contracting and then expanding, 3) dividing the air flow into a plurality of small tributaries and flow along a plurality of unsmooth planes, 4) cooling the air flow.
[0078] For an internal combustion engine, on one hand, a muffler is essential, based on the requirements of environmental protection, and on the other hand, the muffling effect is constrained by the result of the rise of the backpressure. Therefore, the existing muffling technology for an internal combustion engine is often not good to meet these expectations. For a resistive muffler, a plurality of pores are needed to be provided in the muffler to change and divide the air flow. The more, longer, more irregular the pores, the better the resistive muffling effect, but the exhaust backpressure caused by the muffler is also greater and the loss of power that the internal combustion engine can withstand is limited. For reactive muffling, the greater the expansion magnification of the cross-section of the exhaust passage, that is, the greater the volume of the muffler, the more favorable for muffling. However, for most occasions, especially for ships etc. which have limited accommodating spaces, the way of cross-section expansion is difficult to apply. As to ‘cooling’ of the air flow, the existing muffling technology is even more difficult to achieve, particularly in the muffler in a dense space of a ship, where not only the cooling cannot be achieved, but to prevent a high-temperature of several hundred ° C. burning the surrounding facilities and personnel, insulation materials have to be used for a tight wrapping up for ‘preserving heat’.
[0079] The method or apparatus provided by the present invention can make use of the principle of reactive muffling to effect muffling. Therefore, in the method or apparatus provided by the present invention, abrupt expansion of cross-section is formed from the exhaust gas inlet to the interior of the housing. Here, the method or apparatus provided by the present invention at least makes use of the principle of reactive muffling. A reactive muffler is combined from chambers and ducts with abrupt interfaces, making use of abrupt expansion or contraction of cross-section of the pipe to reflect back the sound waves of certain frequencies transmitting along the pipe at the position of sudden change to the direction of the sound source, so as to achieve the purpose of muffling. In the method and apparatus provided by the present invention, abrupt expansion of cross-section is formed from the exhaust gas inlet to the interior of the housing. The abrupt expansion of cross-section here refers to reducing noise of the exhaust gas by making use of the reactive muffling principle.
[0080] If the casing is made into a regular shape, e.g. a cylindrical or other regular shape, tested by the applicant, when the cross-sectional area of the exhaust gas inlet is 0.05 to 0.5 times the housing of the cross-sectional area, the muffling effect is very significant. Accordingly, in a preferred embodiment, the exhaust gas inlet cross-sectional area is 0.05 to 0.5 times the cross-sectional area of the housing. The Applicant has also proved that when the housing volume is 3 to 30 times the displacement of the internal combustion engine, the muffling effect of apparatus is more remarkable, therefore, in a more preferred embodiment, the volume of the housing 3 is ˜30 times the displacement of the internal combustion engine.
[0081] The muffling method provided by the present invention may further take advantage of the principle of resistive muffling to enhance the muffling effect. The exhaust gas can be divided into small tributaries. According to the principle of muffling, the exhaust gas is divided into a small tributary to enhance the muffling effect.
[0082] If the housing is filled with padding capable of forming gaps thereinbetween, the muffling effect may be further enhanced. The presence of padding makes the apparatus a resistive muffler. When the exhaust gas enters into the padding, part of the sound is turned into heat by friction in the pores of the porous material to be dissipated, so that the sound waves through the muffler are weakened. The Applicant has also found that a large area of contact of the liquid with the exhaust gas flow, per se, can absorb the energy of sound waves to facilitate muffling.
[0083] Thus, the present invention belongs to the impedance composite muffling, which has muffling characteristics of both resistance and reactance. Further, the present invention cools the high-temperature exhaust gas of hundreds of degrees Celsius down to tens of degrees Celsius, flowing through the muffler, producing the expansion cooling effect while enhancing the effect of the resistance and reactance. A resistive muffler of the present invention mainly makes use of a large number of pores formed in materials such as the padding, since the exhaust gas is cooled, the volume is contracted, and the flow rate is decreased, the resistance generated when flowing through a large number of pores is decreased by a greater range. Therefore, it is possible to use more padding to make up more, longer and more irregular pores, which makes the following of the present invention all higher than existing muffler technology by several orders: frequency of changes in the direction of airflow, the number of the times of repetition of airflow passing through cross-sections first contracting and then expanding, the number of the small tributaries divided from the gas stream, and the area of an unsmooth passage formed. On the other hand, the reactive muffling of the present invention is achieved from abrupt expansion of the cross-sections formed from the exhaust gas inlet to the interior of the housing. Due to the technical solution of the present invention significantly reduces the exhaust gas volume, which is equivalent to increasing the expansion magnification of the cross-section of the exhaust passage, further enhancing the reactive muffling effect. From another perspective, in the occasions where a great expansion ratio is required and the prior art is difficult to achieve by space limitations, the method or apparatus provided by the present invention can achieve that very well.
[0084] The method of muffling exhaust gas of an internal combustion engine, provided by the present invention, at the same time, has the above-mentioned effect of optimizing the exhaust backpressure of an internal combustion engine. Thus, by using the method provided by the present invention, the effect of optimizing the exhaust backpressure of an internal combustion engine can be achieved as well as muffling effect is achieved by using the same apparatus. In this way, the apparatus of the present invention is mounted to the exhaust passage of an internal combustion engine, so there is no need to install an additional muffler on the ship. Due to the relevant provisions of the existing regulations on the muffling and energy saving, in the existing structure of the ship, the exhaust passage of an internal combustion engine is installed with a waste heat boiler and a muffler. Moreover, in the position of the exhaust path of the internal combustion engine, there is no extra space for installing the apparatus for optimizing the exhaust backpressure of internal combustion engine. By use of the method provided by the present invention, this problem can be well solved, that is, to install the apparatus provided by the present invention in the position of the existing muffler and replace the existing muffler.
[0085] Further, since cooling the exhaust gas itself can achieve the effect of muffling, the present invention also provides a muffling method for exhaust gas of an internal combustion engine, including: making the exhaust gas discharged from the internal combustion engine enter into the interior of the housing through an exhaust gas inlet of the housing, and in addition, said method further including: making the exhaust gas entering into the interior of the housing to come into direct contact with the cooling liquid.
[0086] The present invention also provides a apparatus for muffling the exhaust gas of an internal combustion engine, including: a housing, the housing is provided with an exhaust gas inlet allowing the exhaust gas to enter into the interior of the housing, an exhaust gas outlet allowing the exhaust gas to be discharge out of the housing, a cooling water inlet allowing the cooling liquid to enter into the interior of the housing, a cooling water outlet allowing the cooling liquid to be discharged out of the housing; said cooling water inlet, cooling water outlet, exhaust gas inlet and exhaust outlet are configured so that the cooling liquid and the exhaust gas may come into contact with each other within the housing.
[0087] The present invention also provides a system for muffling exhaust gas of an internal combustion engine, said system comprising an exhaust passage of the internal combustion engine, said system further comprising an apparatus for muffling exhaust gas of an internal combustion engine provided by the present invention, the apparatus is installed in the exhaust passage of the internal combustion engine.
[0088] By using the method, apparatus and system for muffling exhaust gas of an internal combustion engine provided by the present invention, the existing muffler can be replaced, without the need to install other muffler. For an apparatus which can conveniently utilize cooling water, such as vessel sailing on natural water, can be muffled by the method, apparatus or system, provided by the present invention, for muffling exhaust gas of an internal combustion engine. For an apparatus using an internal combustion engine as a power on the land, such as cars, can also use the cooling water of an internal combustion engine as the cooling liquid, so as to proceed muffling of the exhaust gas of an internal combustion engine, by the method, apparatus and system provided by the present invention.
[0089] The method, apparatus and system for muffling exhaust gas of an internal combustion engine can also be functionally combined with existing muffler. For example, an abrupt expansion of cross-section is formed from the exhaust gas inlet to the interior of the housing, thus, rapid cooling of the high-temperature exhaust gas will further enhance the resistance muffling effect.
[0090] In the method, apparatus and system for muffling exhaust gas of an internal combustion engine, provided by present invention, the way of cooling water, contact between cooling water and high-temperature exhaust gas as well as the configuration of inlet and outlet can be the same as or similar to the method, apparatus and system for optimizing exhaust backpressure of an internal combustion engine as described above.
[0091] Data shows that the diesel engine exhaust gas and cooling medium take away heat about 50% of the total fuel heat, most of which is discharged in the form of high-temperature exhaust gas into the atmosphere. The existing shipbuilding regulations, in addition to environmental regulations on muffling, also requires installing waste heat boiler in the exhaust passage of an internal combustion engine. The waste heat boiler, also known as exhaust gas boiler, the role of which is to recycle the heat in the exhaust gas, in order to achieve the purpose of energy saving. The structure of the existing waste heat boiler is a duct encapsulating cooling water, located in the exhaust passage of the internal combustion engine. Thus a contradiction exists: If it is desired to more fully recover waste heat, the pipe encapsulating the cooling water and the exhaust gas of an internal combustion engine is required to fully contact, which would require the pipe encapsulating the cooling water are more densely distributed in the exhaust pipe of the internal combustion engine, which is bound to increase exhaust resistance and the exhaust backpressure, and thereby adversely affect the effectiveness of the internal combustion engine. It is also because of this, the waste heat boiler in the existing vessels does not have high heat recovery efficiency.
[0092] In various embodiments of the method and apparatus provided by the present invention, if the cooling liquid (cooling water) is in direct contact with the exhaust gas for cooling exhaust gas, the cooling water (i.e., hot water) having absorbed heat of the high-temperature exhaust gas can be discharged and utilize the heat therein. Thus, the method and apparatus provided by the present invention can also perform a waste heat recovery function. Accordingly, the method provided by the present invention further comprises: conveying the cooling liquid which has absorbed heat of the high-temperature exhaust gas to the heat utilization apparatus or heat exchanger. The system provided by the present invention further comprises a heat utilization apparatus or heat exchanger, and a duct for conveying fluid to the heat utilization apparatus or heat exchanger.
[0093] Some transportation of goods such as heavy oil, asphalt etc. needs heat source to preserve heat; hot water can be utilized directly; the apparatus using hot water to preserve heat is a heat utilization apparatus. Some transportation of other goods, such as refrigerated transport vessels also need a heat source (specific scheme belonging to the scope of conventional design) is used for cooling, the recovered waste heat by the scheme of the present invention can meet all or part of heat requirements thereof.
[0094] Since the method and apparatus of the present invention make use of a cooling liquid such as cooling water to absorb the large amount of heat that brought by the high-temperature exhaust gas that is originally to be discharged into the atmosphere at the same time of improving the efficiency of the internal combustion engine. The cooling water which has absorbed heat from the exhaust gas becomes the intermediate hot, and can be directly used again, and can also be reused after been transferred into clean hot water by way of a liquid-liquid heat exchange with high heat exchange efficiency. For example, a ton class ship has exhaust emissions of about 1220 kg/h, the temperature of the exhaust gas discharged to the atmosphere exceeds 300° C. under MCR conditions (80% of the rated power), the heat of which is all abandoned. The temperature of the exhaust gas discharged to the atmosphere through the apparatus of the present invention is stabilized at about 50° C. or 30° C. when the ship is under MCR working conditions, allowing the heat of millions of calories per hour that is formerly abandoned to be recycled. Accordingly, the waste heat boiler on the exhaust pipe of the original internal combustion engine may be completely substituted by the present apparatus. Meanwhile, the recycled waste heat is used to produce hot water and/or steam as required.
[0095] For this purpose, the cooling water pump of the apparatus of the present invention is also designed to adjust the size of the flow, by changing the amount of cooling water to achieve temperature adjusting of the hot water produced, so as to better adapt to the need for utilization of waste heat, to further improve the efficiency of waste heat utilization.
BRIEF DESCRIPTION OF THE DRAWINGS
[0096] FIG. 1 is a schematic diagram of the apparatus for optimizing exhaust backpressure of an internal combustion engine, according to a first embodiment of the present invention;
[0097] FIG. 2 is a schematic diagram of the system for optimizing exhaust backpressure of an internal combustion engine, according to a first embodiment of the present invention;
[0098] FIG. 3 is a schematic diagram of the correlation between exhaust backpressure and engine load rate, according to a first embodiment of the present invention;
[0099] FIG. 4 is a schematic diagram of the correlation between exhaust temperature and engine load rate, according to a first embodiment of the present invention;
[0100] FIG. 5 is a schematic diagram of the apparatus for optimizing exhaust backpressure of an internal combustion engine, according to a second embodiment of the present invention;
[0101] FIG. 6 is a schematic diagram of the system for optimizing exhaust backpressure of an internal combustion engine, according to a third embodiment of the present invention;
[0102] FIG. 7 is a schematic diagram of the system for optimizing exhaust backpressure of an internal combustion engine, according to a forth embodiment of the present invention;
[0103] FIG. 8 is a schematic diagram of the apparatus for optimizing exhaust backpressure of an internal combustion engine, according to a fifth embodiment of the present invention;
[0104] FIG. 9 is a schematic diagram of the apparatus for optimizing exhaust backpressure of an internal combustion engine, according to a sixth embodiment of the present invention; and
[0105] FIG. 10 is a schematic diagram of the apparatus for optimizing exhaust backpressure of an internal combustion engine, according to a seventh embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0106] FIG. 1 to FIG. 4 show the apparatus and system for optimizing exhaust backpressure of an internal combustion engine according to the first embodiment of the present application.
[0107] As shown in FIG. 1 , in this embodiment, the apparatus for optimizing exhaust of an internal combustion engine comprises housing 6 provided with a cooling water inlet 10 and a cooling water outlet 11 . Wherein, cooling water inlet 10 is located on the upper portion of the side surface of the housing, and cooling water outlet 11 is located on the lower portion of the side surface of the housing. Under the effect of gravity, cooling water entering the housing from cooling water inlet 10 pass through from top to bottom, and is discharged through cooling water outlet 11 .
[0108] The housing 6 is also provided with an exhaust gas intake pipe 8 and an exhaust gas outlet 9 . Wherein, the exhaust gas intake pipe 8 extends into the interior of the housing, the pipe orifice extending into the interior of the housing being an exhaust gas inlet 7 . The exhaust gas inlet 7 is located at the bottom of the housing, and the exhaust gas outlet 9 is located at the top of the housing. The exhaust gas entering housing 6 from exhaust gas inlet 7 passes through in the interior of the housing from bottom to top and is discharged through exhaust gas outlet 9 .
[0109] Wherein, the cooling water outlet 11 is located below the exhaust gas inlet 7 in the direction of gravity, so that the cooling water flowing to or falling onto the bottom of the housing does not enter exhaust gas intake pipe 8 through exhaust gas inlet 7 under the effect of gravity.
[0110] Padding which forms gaps thereinbetween is filled within the housing 6 , form padding layer 12 . A water distributor 14 is provided above padding layer 12 .
[0111] Further, in order to prevent the cooling water from entering exhaust gas intake pipe 8 from exhaust gas inlet 7 , a water baffle 13 is also provided between exhaust gas inlet 7 and padding layer 12 . Water baffle 13 is located right above exhaust gas inlet 7 , completely blocking the liquid from top to bottom in the vertical direction to not allow the liquid into exhaust gas inlet 7 . The edge part of the upper surface of water baffle 13 is lower than the central part, so that the rinsing water flowing to or falling onto water baffle 13 further flows to or falls onto the bottom of the housing, which further prevents the rinsing water from entering exhaust gas inlet 7 .
[0112] Hereby exhaust gas intake pipe 8 and exhaust gas inlet 7 are configured to make exhaust gas smoothly reaches inlet 7 , and avoiding water baffle 13 , and then enters into the housing, in order that the high-temperature and high velocity exhaust gas discharged from an internal combustion engine does not turn direction suddenly before reaching exhaust gas inlet 7 due to the obstruction of water baffle 13 , causing a large exhaust resistance.
[0113] As shown in FIGS. 1 and 2 , in use, apparatus 5 for optimizing exhaust backpressure is mounted in the exhaust passage of an internal combustion engine of a ship, the apparatus together with the exhaust passage of an internal combustion engine constituting a system for optimizing exhaust backpressure of an internal combustion engine. The internal combustion engine of the ship is equipped with a turbocharger 2 thereon. In the existing structure of a ship, an exhaust passage of an internal combustion engine is installed with a waste heat boiler and a muffler according to the relevant provisions of the existing regulations on muffling and energy efficiency; moreover, there is no surplus space for further installation of device with large dimensions in the place where the exhaust passage of the exhaust gas from an internal combustion engine. In the present embodiment, apparatus 5 for optimizing exhaust backpressure of an internal combustion engine is mounted in a muffler's position in an existing ship, replacing the original muffler and waster heat boiler. Exhaust gas intake pipe 8 communicates with exhaust pipe 3 of an internal combustion engine, and chimney 4 communicates with exhaust gas outlet 9 . Further, in the present embodiment, the system for optimizing exhaust backpressure of an internal combustion engine may also include cooling water inlet pipe 16 , cooling water outlet pipe 17 , pump 18 , control valve 19 , heat exchanger 20 , and heat utilization apparatus 21 , wherein cooling water inlet pipe 16 , apparatus 5 for optimizing exhaust backpressure of an internal combustion engine, cooling water drain pipe 17 constitutes a flow path of cooling water. Heat exchanger 20 is mounted on the cooling water drain pipe 17 for transferring the heat of the cooling water having absorbed heat to another fluid, and for further transferring to heat utilization apparatus 21 for utilization.
[0114] The apparatus and system of the present embodiment is used by the following method: when the ship is sailing in the ocean, the internal combustion engine works to produce high-temperature exhaust gas (approximately 500° C. or so), which is discharged through exhaust pipe of the internal combustion engine and then enters the housing of the apparatus for optimizing exhaust backpressure of an internal combustion engine through exhaust gas inlet pipe; cooling water inlet pipe extracts sea water directly from its immediate natural environment, and sea water is conveyed into the housing of the apparatus for optimizing exhaust backpressure of an internal combustion engine via pump. Under the effect of exhaust pressure and natural diffusion, exhaust gas flows by in the interior of the housing from bottom to top; under the effect of gravity, sea water flows by in the interior of the housing from top to bottom. High-temperature exhaust gas is divided into small tributaries in padding layer, and comes into contact with sea water to be quickly cooled. The cooled exhaust gas (approximately 30° C. to 80° C. after passing through padding layer) is discharged into the atmosphere through the chimney. Sea water having absorbed heat is drained from the cooling water outlet, and then flows through the cooling water drain pipe to transfer heat to another fluid via heat exchanger, and then is discharged into the ocean. Another fluid that has absorbed heat in the heat exchanger is conveyed to heat utilization apparatus to be utilized.
[0115] The above embodiment utilizes padding layer having large gaps to divide high-temperature exhaust gas into a plurality of small tributaries so as to provide certain amount of exhaust resistance and rapidly cool the high-temperature exhaust gas in padding layer. The cooled high-temperature exhaust gas has a sudden extraction in its volume and the quantity and rate of flow thereof declined, and the resistance caused thereby is decreased by a larger extent. The exhaust backpressure of the internal combustion engine is relatively lowered, so that not only the working condition of ventilation of the internal combustion engine is improved, but also pressure boost efficiency of the turbocharger is enhanced. In the present embodiment, the exhaust backpressure relatively decreases with the increase of the load, thus completely eliminating the factors sensitive to exhaust backpressure. In addition, as the present embodiment also provides a certain amount of backpressure when the internal combustion engine is under low load, the torque of the internal combustion engine is thus increased.
[0116] In the present embodiment, apparatus 5 for optimizing exhaust backpressure of an internal combustion engine also plays a role of a muffler. The principle of muffling pertains to the impedance composite muffling, having both muffling characteristics of resistance and reactance. As the high-temperature exhaust gas of hundreds of degrees Celsius is cooled down to several tens of degrees Celsius, producing a cooling expansion effect of simultaneously enhancing muffling effect of resistance and reactance, thus a better muffling effect is obtained than prior art.
[0117] A ton class vessel is installed with the system for optimizing exhaust backpressure of an internal combustion engine provided by the embodiment. The main pushing diesel engine displacement thereof is P=336 liters, combusting heavy oil with sulfur content of 2% to 3% mm. According to the spatial conditions along the path of the exhaust passage of the internal combustion engine, the volume of the housing of the apparatus for optimizing exhaust backpressure of an internal combustion engine is selected in the scope of 3-30 times of exhaust amount of the internal combustion engine. According to size of the exhaust gas intake pipe 3 , cross-sectional area of the exhaust gas intake pipe is 0.3 m 2 , and cross-section area of housing is selected according to 0.05-0.5 time thereof, then the volume of the housing is selected as 5.3 m 3 , cross-sectional area selected as 1.8 m 2 . An apparatus for optimizing exhaust backpressure of an internal combustion engine is installed on the exhaust passage of the main pushing diesel internal combustion engine, and the main pushing internal combustion engine of that ship is no longer configured with muffler and waste heat boiler.
[0118] The cooling water conveyed to the apparatus for optimizing exhaust backpressure of an internal combustion engine is extracted from sea water by pump, the amount of cooling water being controlled to be 20-100 m 3 /h.
[0119] Tested by the applicant, after the above vessel applied with this embodiment, the exhaust noise of the vessel is reduced by 23 db.
[0120] FIG. 3 is a schematic diagram showing the relationship between the exhaust backpressure of the vessel and load rate of the internal combustion engine that are tested by the applicant in the first embodiment, wherein the data of the prior art is obtained by testing the vessel (other configuration are the same as the configuration of the vessel of the present embodiment) mounted with muffler and waste heat boiler. The exhaust backpressure data is collected from exhaust gas inlet, with unit of Pa. It can be seen from the result in the figure that after installing the apparatus of the present invention, the exhaust backpressure of the present embodiment is a little larger than that of the prior apparatus (muffler) when the internal combustion engine is under low load. With the increase of the load of an internal combustion engine, the exhaust backpressure of the prior art increases rapidly, while the exhaust backpressure of the present embodiment increases with a velocity and extent much smaller than that of the prior art.
[0121] FIG. 4 is a schematic diagram showing the relationship between exhaust gas temperature of the vessel and the load rate of the internal combustion engine that are practically tested by the applicant in the first embodiment, wherein the data of the prior art is obtained by testing the vessel (other configuration are the same as the configuration of the vessel of the present embodiment) mounted with muffler and waste heat boiler. The data of temperature is collected at the discharge port of the chimney. It can be seen from the result in the figure that in a vessel of the prior art, the temperature of the exhaust gas discharged is increased with the increase of the load of an internal combustion engine, maximum to about 350° C. Obviously, there is a lot of waste heat in the exhaust gas that is not utilized yet. While after installing the apparatus of the present embodiment, the exhaust temperature has been stable at about 30° C.
[0122] FIG. 5 shows an apparatus for optimizing exhaust backpressure of an internal combustion engine according to the second embodiment of the present invention.
[0123] In this embodiment, different from the apparatus for optimizing exhaust backpressure of an internal combustion engine in the first embodiment, exhaust gas inlet 7 of the apparatus for optimizing exhaust backpressure of an internal combustion engine is located on the lower portion of the side surface of housing 6 ; in the direction of gravity, the position of exhaust gas inlet 7 is higher than that of rinsing water outlet 11 . In this case, the exhaust passage of the internal combustion engine communicates with the side surface of the housing through exhaust gas inlet 8 . As the exhaust gas enters from the side surface of the housing, there is no need for a water baffle.
[0124] The exhaust passage of the internal combustion engine communicates with the side surface of the housing of the apparatus for optimizing exhaust backpressure of an internal combustion engine. In the present embodiment, the displacement of the internal combustion engine is P=33 liter, housing volume is 0.2 m 3 , cross-sectional area is 0.3 m 2 , cross-sectional area of exhaust gas intake pipe is 0.06 m 2 .
[0125] FIG. 6 illustrates a system for optimizing exhaust backpressure of an internal combustion engine according to the third embodiment of the present invention.
[0126] Different from the system for optimizing exhaust backpressure of an internal combustion engine in the first embodiment, in this embodiment, the cooling water in the system for optimizing exhaust backpressure of an internal combustion engine is taken from the cooling water of the internal combustion engine, the cooling water which has absorbed heat can be directed drained in the same way as the cooling water of the internal combustion engine.
[0127] FIG. 7 illustrates a system for optimizing exhaust backpressure of an internal combustion engine according to the forth embodiment of the present invention.
[0128] Different from the system for optimizing exhaust backpressure of an internal combustion engine according to the first embodiment, in this embodiment, the system for optimizing exhaust backpressure of an internal combustion engine, in addition to including a pipe conveying the fluid of the housing to heat exchanger 20 , also includes a pipe conveying the fluid of heat exchanger 20 to the housing.
[0129] In this kind of system for optimizing exhaust backpressure of an internal combustion engine, the cooling water that has absorbed heat from high-temperature exhaust gas is conveyed to the housing to act as cooling water again after passing through heat exchanger 20 , so as to realize recycling utilization.
[0130] Further, the system for optimizing exhaust backpressure of an internal combustion engine in this embodiment also includes impurity separator 22 installed in the cooling water drain pipe for filtering the impurities in the cooling water, discharging the impurities from impurity discharge pipe 24 , so as to prevent particles brought by the cooling water from accumulating too much. Impurity separator 22 has the function of adding cooling water at the same time, supplementing through cooling water supplementing pipe 23 the cooling water decreased due to evaporation.
[0131] FIG. 8 illustrates the apparatus for optimizing exhaust backpressure of an internal combustion engine according to the fifth embodiment.
[0132] In this embodiment, heat dissipating member 25 is provided in the housing of the apparatus for optimizing exhaust backpressure of an internal combustion engine, i.e. cooling member. Heat dissipating member 25 is composed of heat pipe 26 , heat absorbing sheet 27 and heat dissipating sheet 28 . Heat absorbing sheet 27 is located in the interior of the housing, made of good heat conductor, for dividing the exhaust gas into small tributaries and absorbing the heat in the exhaust gas. Heat dissipating sheet 28 is located outside of the housing, made of good heat conductor, for releasing heat into the environment. Heat pipe 26 connects heat absorbing sheet 27 and heat dissipating sheet 28 , made of good heat conductor, for transferring the heat absorbed by the heat absorbing sheet to the heat dissipating sheet.
[0133] When the high-temperature exhaust gas discharged from the internal combustion engine passes through the apparatus in this embodiment, it is divided by heat absorbing sheet 27 into small tributaries, and is cooled at the same time through heat exchanging with heat dissipating member 25 .
[0134] The apparatus for optimizing exhaust backpressure of an internal combustion engine in this embodiment may also be directly installed in device using internal combustion engine as the power on the land, such as automobiles.
[0135] FIG. 9 illustrates the apparatus for optimizing exhaust backpressure of an internal combustion engine according to the sixth embodiment of the present invention.
[0136] Cooling pipe 29 allowing cooling water flowing therein is provided in the housing of the apparatus for optimizing exhaust backpressure of an internal combustion engine in this embodiment, i.e. cooling member. Cooling pipe 29 is densely distributed in the housing, and thus may acts to divide the exhaust gas into small tributaries.
[0137] In use, cooling water is kept flowing in the cooling pipe, and the exhaust gas is rapidly cooled during the process of being divided into small tributaries. The cooling water forms vapor after absorbing the heat from the high-temperature exhaust gas, and the vapor formed may be conveyed to heat utilization apparatus to be directly utilized.
[0138] The apparatus in this embodiment may be installed on the ship, the cooling water being taken from the sea water, river water or lake water from a natural water body. Cooling water may also use the cooling water of the internal combustion engine. The apparatus may also be installed in an automobile, and the cooling water may also use the cooling water of the internal combustion engine.
[0139] FIG. 10 illustrates the apparatus for optimizing exhaust backpressure of an internal combustion engine according to the seventh embodiment of the present invention.
[0140] The apparatus for optimizing exhaust backpressure of an internal combustion engine in this embodiment includes housing 6 provided with exhaust gas inlet 7 and exhaust gas outlet 9 . Different from above, no abrupt expansion of cross-sections is formed from exhaust gas inlet 7 to the interior of the housing, wherein the existence of exhaust gas inlet 9 reduces the cross-section of the exhaust passage so as to provide a certain amount of exhaust resistance.
[0141] The apparatus in this embodiment also includes sprayer 15 , for spraying cooling water to the interior of the housing, thereby rapidly reducing the temperature of the high-temperature exhaust gas. The cooling water which has absorbed heat is discharged from cooling water outlet 11 .
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A method for optimizing exhaust backpressure of an internal combustion engine, comprising the following steps: 1) arranging a damping component in an exhaust passage of the internal combustion engine, and allowing an exhaust discharged by the internal combustion engine to pass through the damping component; and 2) allowing the exhaust to be cooled prior to passing through the damping component, or allowing the exhaust to be cooled while passing through the damping component. The method allows for relatively high exhaust backpressure when the internal combustion engine has a low load, and for preventing the exhaust pressure from rising excessively rapid when the internal combustion engine has a heavy load. The apparatus and system for optimizing exhaust backpressure of an internal combustion engine is also provided.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to shower curtain holders and, more specifically, to an hollow sphere, mountable on a shouwer curtain rod, in which the sphere has a slotted surface adjacent to an internally formed pin for supporting a portion of the shower curtain, and the like.
2. Prior Art
The number of times in which relatively commonplace devices are accepted by the public in spite of years of unsatisfactory service is surprisingly large. Shower curtain holders are illustrative of this group. The usual shower curtain holder is resilient metal or plastic hook, the wide bight of the hook riding on the shower curtain rod. The narrower bight of the hook carries the usual shower curtain grommet and engages the free end of the hook to secure the hook and the supported portion of the shower curtain on the rod.
This structure has a number of significant shortcomings. If the hook is produced from a metal, being exposed frequently to moist conditions, it is subject to an unsightly and damaging corrosive attack, unless a further expensive chrome plating or other corrosion resistant treatment is provided. Having about the same hardness as the shower curtain rod, the hook and the rod often produce a jarring sound whenever the shower curtain is thrust aside or drawn across the opening to the shower stall. Further in this regard, the hook, scraping against the surface of the rod tends to promote corrosive attack on the rod, to give the entire structure a most displeasing appearance. More disturbing, however, it the fact that after showering is finished, the wet surface of the curtain, hanging from an array of hooks, tends to gather into folds that can promote an unsightly growth of mold or accumulation of soap residue. This is, perhaps, a primary reason for the frequent replacement of shower curtains. The exposed grommets on the shower curtain also are a source of dissatisfaction, in that the usual hooks expose the associated grommets to view, creating thereby an aesthetically unpleasing appearance.
A few of these problems have been alleviated to a very limited extent through the adoption of plastic hooks. These plastic hooks nevertheless still fail to overcome the exposed grommet, mold and soap residue problem and produce a similar squeeky and jarring sound when the curtain is drawn across or back. Also both plastic and metal hooks having one contact point on the rod cause not only the jarring sound but also a resistance to movement which causes the operator to tug harder on the end of the curtain, ofter over time causing the plastic grommets or curtain to stretch or tear at the ends.
Accordingly, there is a need for a sturdy, relatively inexpensive shower curtain holder that will not scrape the shower curtain rod or corrode, that glides easily and diminishes risk of tearing the shower curtain and that sustains the shower curtain in a manner that promotes the rapid draining and drying of the wet curtain surface to inhibit mold growth and soap residue accumulation.
BRIEF DESCRIPTION OF THE INVENTION
These needs are, to a large extent, satisfied through the practice of the invention. Typically, an hollow plastic member is divided into two members that are, preferably, approximate halves. Aligned apertures to accommodate the diameter of a conventional shower rod are formed at the division plane for the two halves. A slot also is provided along a portion of the division plane, and a grommet supporting pin is spaced inwardly from the slot in the members.
The two halves are joined together on the shower rod with a shower curtain grommet on the pin or its associated receptacle. The sides of the slot tend to dress, or straighten the adjacent portions of the shower curtain, that is, a length of about 31/2" of the curtain are held aligned, counting both sides of the grommet, thereby eliminating, to a large degree, the fluting or folds that are often responsible for mold growth and soap residue accumulation, as well as completely concealing the associated grommet from view.
The plastic construction of the members also tends to eliminate jarring noises and the corrosion promoting scraping that takes place when the shower curtain and its attached holders are moved. This friction caused by other types of hooks imposes a greater effort to pull the curtain from side-to-side and thereby, over time, causes damage to the curtain. Certainly, the improved appearance provided through this invention not only by the lack of corrosion, mold and soap residue, but also by the visually more pleasing effect of the hollow members and major reduction in the unpleasant sound effects and strain on the curtain grommets are important features of the invention.
For a more complete appreciation of the invention, attention is invited to the following detailed description of a preferred embodiment, taken with the features of the drawing. The scope of the invention, however, is limited only through the claims appended hereto.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an exploded assembly view of a side elevation of a typical embodiment of the invention; and
FIG. 2 is an assembly view of the embodiment of the invention shown in FIG. 1.
DESCRIPTION OF THE PREFERRED EMBODIMENT
For a more detailed understanding of the invention, attention is invited to FIG. 1 which shows an hollow, spherical member 10. Although the illustrative member 10 in the preferred embodiment is a sphere, any suitable shape, of which a cube, or the like is exemplary, can be used in accordance with the principles of the invention. The spherical member 10 is divided along a great circle into a male half 11 and a female half 12. The male half has three protruding locking pins, of which only pins 13 and 14 are shown in the drawing, the third pin (not shown) being blocked from view in FIG. 1 projection by the pin 14.
Small circles, apertures or aperture portions, formed in part by semicircular bights 18, 19 in the respective halves 11, 12 each are somewhat larger in diameter than the outside diameter of a conventional shower rod (not shown in the drawing). Also not shown in the drawing is a companion set of semicircular bights, each in a respective one of the halves 11, 12 and diametrically aligned with the corresponding bights 18, 19.
The protruding locking pins 13, 14 and a similarly protruding grommet support pin 15 (as well as the third locking pin that is not shown) each are aligned with bores or recesses formed in pin receptacles of which only the locking pin receptacles 16, 17 and the grommet support pin receptacle 20 are shown in the drawing. Preferably, to hold the halves 11, 12 together in an environment of expansion and contraction caused by heat and steam, as well as to permit the halves to be assembled and disassembled without causing the pins 13, 14, 15 to break, it has been found that the three pins (of which only the pins 13, 14 are shown) should protrude about 1" beyond the great circle plane of the hemisphere 11 and that the grommet support pin 15 should protrude about 11/4" in the same direction.
It should be noted that, in accordance with a salient feature of the invention, the grommet or shower curtain hanger aperture support receptacle 20 protrudes well beyond the plane that separates the spherical member 10 into the two hemispherical halves 11, 12. Preferably, the length of the protrusion for the receptacle 20 is at least equal to the combined widths of recessed sides 26, 27 which form an arcuate slot 25 (FIG. 2) in the plane of the great circle that separates the hemispherical members 11, 12.
Ordinarily, the slot 25 should extend along the circumference of the great circle for only slightly less than a full semicircle, with the grommet receptacle 20 in alignment with the center of the spherical member 10 and the midpoint of the arc of the slot 25.
In operation, the halves 11, 12 are aligned on opposite sides of a shower curtain rod (not shown) so that each of the pins 13, 14, 15 will be received with its respective one of the receptacles 16, 17, 20. A shower curtain grommet or hanging aperture 22 (FIG. 2) and its associated shower curtain portion 21 is mounted on the grommet support pin receptacle 20. The two halves 11, 12 (FIG. 1) are moved together in the directions of respective arrows 24, 23 until the entire assembly snaps shut with the pins 13, 14 15 each nested securely within the bore formed in its respective one of the receptacles 16, 17, 20. The grommet 22 and the shower curtain 21 are supported by the grommet support receptacle 20, the sides 26, 27 of the slot 25, dressing the shower curtain out flat for at least the 31/4" of containment by each of the members 11,12 largely eliminate the fluting and folds that heretofore inhibited the drainage and drying of the curtain's surface.
The member 10 is formed, preferably, by injection molded plastic technique and, for this purpose, it has been found that a plastic identified as PETG, sold under the tradename KODAR by the Eastman Kodak Company of Rochester, N.Y., provides the best combination of cost, desirable production characteristics and product durability thus constituting a major feature of the invention. General purpose polypropylene also has been found to be suitable if the member 10 is to have opaque color characteristics from color mixed in the pre-injected plastic. While both of the plastics were finally chosen for cost and their inherent properties of flexibility, durability and the like, the design of the locking pins and therefore the mold had to provide internal supporting structure to counteract the inherent elasticity of the materials. A fine balance had to be struck between best design and plastics for smoothest operation and lowest possible breakage.
Thus, there is provided a device that not only conceals the grommet from view, as well as to eliminate a principal source of mold growth and soap residue accumulation, but also avoids a main cause of scraping and corrosion and the jarring sound in pulling the curtain back and forth, besides largely eliminating the stress that often is applied to the end shower curtain grommets. This is accomplished, moreover, through a structure that can be manufactured inexpensively in any number of pleasing shapes, colors being either added to the plastic prior to molding, or applied after the molding is finished.
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An hollow sphere, in accordance with the preferred embodiment of the invention, has a slot formed on a somewhat less than semicircular portion of the great circle that separates the sphere into two hemispheres. A shower curtain grommet support is spaced inwardly of said slot to engage a shower curtain grommet and support a portion of the curtain. A pair of diametrically aligned small circles in the plane of hemispherical separation enables the holder to move freely on a shower curtain rod.
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This application claims the benefit, under 35 U.S.C. §365 of International Application PCT/US03/38753, filed Dec. 4, 2003, which was published in accordance with PCT Article 21 (2) on Jun. 24, 2004 in English and Which claims the benefit of U.S. provisional patent application Ser. No. 60/431,526, filed Dec. 6, 2002 and U.S. provisional patent application No. 60/433,443, filed Dec. 13, 2002.
FIELD OF THE INVENTION
The present invention relates to providing video services in a Multi-Dwelling or Multi-Tenant network. More particularly, the present invention relates to a method and system for remote tuning and clock synchronization.
BACKGROUND OF THE INVENTION
This section is intended to introduce the reader to various aspects of art, which may be related to various aspects of the present invention that are described and/or claimed below. This discussion is believed to be helpful in providing the reader with background information to facilitate a better understanding of the various aspects of the present invention. Accordingly, it should be understood that these statements are to be read in this light, and not as admissions of prior art.
Over the last few years, many multi-dwelling (“MxU”) establishments, such as hotels, motels, apartments and the like have begun to expand into the business of providing digital data signals, such as digital video or internet services, to their patrons. Besides providing higher quality video than older analog video systems, digital data systems provide the hotel or motel owner the flexibility to supply video-on demand, internet access, and pay-per-view video to each room over one connection. Further, because hotel and motel operators are also usually able to charge residents a premium for digital data services, an increasing number of multi-dwelling establishments are investing in digital data systems. Unfortunately, distribution of digital broadcast signals, such as satellite broadcasts, over wires/networks requires significant amounts of bandwidth. Providing and maintaining this bandwidth can be expensive or prohibitive for the owners of multi-dwelling establishments.
A further problem in the distribution of digital data to a multi-dwelling establishment is the problem of clock jitter. A stable timing clock is vital to the decoding of digital signals because the system clock is used for buffer and color burst control. Without a stable timing clock, the video quality and reliability can be degraded.
Typically, a video broadcast system, such as satellite or cable, will embed a clock signal within the audio/video (“A/V”) data signal by time stamping certain transport packets within the A/V data signal as they are broadcast. Because the delivery of the transport streams is deterministic, the time stamps provide a relative time base between the packets of this type. When one of these packets is received, the receiving system compares its local clock to the time stamp and creates a relative time base. By comparing multiple time stamps within the A/V data signal, the receiving system is able to adjust its local clock until it matches the broadcaster's clock. This type of clock recovery is typically used in digital video broadcast system today. However, because the MxU system converts the A/V data signal into Internet Protocol (“IP”) packets introducing jitter, the conventional method of clock recovery will not work for network set top box systems.
SUMMARY OF THE INVENTION
The disclosed embodiments relates to a system for providing remote tuning and clock synchronization in a network. The system includes a device that receives a signal that includes a plurality of channels, a device that receives a user request indicative of a desire to view at least one of the plurality of channels, and a filter that filters the received signal and transmits a user signal corresponding to the at least one of the plurality of channels to the user. An alternative embodiment of the system may include a device that receives a signal that includes a plurality of packets, at least a portion of the plurality of packets comprising an embedded time stamp, a device that detects at least a portion of the plurality of packets containing the embedded time stamp, and a device that computes an adjusted time stamp based on the embedded timestamp and a precision local clock and incorporates the adjusted timestamp into the at least a portion of the plurality of packets containing the embedded timestamp prior to transmitting the at least a portion of the plurality of packets to the network.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is a block diagram of a digital data system adapted for use in a Multi-Dwelling Unit in accordance with embodiments of the present invention;
FIG. 2 is a block diagram of a satellite receiver in accordance with embodiments of the present invention;
FIG. 3 is a block diagram of a transport packet used for passing the parameters for the Altered Corrected Network Time Stamp (“ACNTS”) in accordance with embodiments of the present invention;
FIG. 4 is a block diagram of a network in which embodiments of the present invention may be employed;
FIG. 5 is a block diagram of an alternative network configuration in which embodiments of the present invention may be employed;
FIG. 6 is a block diagram of a clock recovery packet in accordance with embodiments of the present invention;
FIG. 7 is a block diagram of a device that performs clock jitter removal in accordance with embodiments of the present invention; and
FIG. 8 is a block diagram of a packet discriminator in accordance with embodiments of the present invention.
The characteristics and advantages of the present invention will become more apparent from the following description, given by way of example.
DETAILED DESCRIPTION
One or more specific embodiments of the present invention will be described below. In an effort to provide a concise description of these embodiments, not all features of an actual implementation are described in the specification it should be appreciated that in the development of any such actual implementation, as in any engineering or design project, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which may vary from one implementation to another. Moreover, it should be appreciated that such a development effort might be complex and time consuming, but would nevertheless be a routine undertaking of design, fabrication, and manufacture for those of ordinary-skill having the benefit of this disclosure.
Turning now to the drawings and referring initially to FIG. 1 , a block diagram of a digital data system adapted for use in a Multi-Dwelling Unit in accordance with embodiments of the present invention and designated using a reference numeral 10 . The digital data system 10 is an integrated-digital data system to provide broadband, digital video, and services to multiple users. An additional feature of the digital data system 10 is its ability to integrate quality audio and video with digital IP data services for multiple users. Further, the digital data system 10 is designed to provide a platform to launch a variety of cost effective digital services and is designed to be both scalable and to allow different digital data services to be added incrementally.
The digital data system 10 includes a Mini-Headend unit 12 where digital audio, video, and data services are received, aggregated together and distributed throughout a Multi-Dwelling Unit or Multi-Tenant Unit (“MxU”) network 14 . The MxU network 14 may be located in one or more apartment buildings, hotels, or any other structure where there are multiple clients desiring digital audio, video, or data services.
The Mini-Headend unit 12 is responsible for receiving data, providing Quality of Service (“QoS”) in accordance with industry standards, providing customized services, and routing data to dwelling units 16 in the MxU network 14 . A Core Video Service System 18 , an Advanced Video Services System 22 , a Data Service System 24 communicatively connected to the Internet 26 , and a Gigabit QoS Ethernet Switch 28 may also be included in the Mini-Headend unit 12 .
The Core Video Service System 18 preferably includes a Satellite Receiver System 19 that is communicatively coupled to orbiting satellites 20 . The satellites 20 transmit a signal 15 that is received by the Core Video Service System 18 . In one embodiment, the Satellite Receiver System 19 receives A/V data signals from a Satellite video provider, such as DirecTV. An additional feature of the Satellite Receiver System 19 is the ability to scale the number of A/V data signals received from the orbiting satellites 20 based on how many users request services. More specifically, in this embodiment, the Satellite Receiver System 19 runs a multi-cast server to allow a Network Set Top Box (“NSTB”) 44 in the dwelling units 16 to request A/V data signals. The NSTB may be capable of requesting data from the Mini-Headend unit and may be capable of decrypting and decoding video streams. The number of satellite transponders that the Satellite Receiver System 19 is able to receive can be adjusted by scaling the number of tuning blades in the chassis up or down. A fully-loaded chassis or the like can contain numerous transponders and may be able to handle an input data rate of 2.4 Gbps or higher. Once the satellite signals are received, the Satellite Receiver System 19 can output IP data packets to the Gigabit QoS Ethernet switch 28 . The IP data packets may also conform to QoS specifications set forth in IEEE 802.1 p (entitled “Traffic Class Expediting and Dynamic Multicast Filtering”) and IEEE 802.1q (entitled “Virtual LA/Vs”), which are incorporated by reference.
The Satellite Receiver System 19 may have a 1 Gbps Ethernet port which functions as a network interface. The network interface can also be expanded to include another Ethernet port if desired. In addition, a management system that accepts requests for programs from the clients may also be included in the Satellite Receiver System 19 . The management system can allow the user to select a satellite, transponder, and program IDs, which in turn could allow the Satellite Receiver System 19 to provide specific program streams to the user. The management system may also support multi-casting to save bandwidth. Although the Satellite Receiver System 19 and the satellites 20 are illustrated as the content delivery medium in FIG. 1 , the use of other media (e.g., cable, fiber and the like) for delivering content is considered within the scope of the invention.
The Advanced Video Services System 22 is a platform that works in conjunction with the Satellite Receiver System 19 to enable additional digital video services. Because it is scalable, the Advanced Video Services System 22 can be adjusted depending on the number of users that use the service. For example, the Advanced Video Services System 22 may require more servers 30 as the number of users increases. The types of services provided by the Advanced Video Services System 22 may include Video On Demand, Near Video On Demand, Limited Video On Demand, Nielsen Ratings, Time Shift, Auto Record, Personal Video Recording (“PVR”), and the like. A Conditional Access System can also be used in conjunction with the Advanced Video system 22 for program streams that are recorded to hard drive(s) 32 .
When recording, the original program stream received from the Satellite Receiver System 19 is decrypted, picture data is extracted, and a new program stream (containing the extracted picture data) is encrypted and stored onto the hard drive 32 . In this embodiment, the network provider's conditional access system is terminated at the Advanced Video System Server 30 and the new conditional access system is used thereafter.
The Data Service System 24 may be used to provide internet access to the MxU network 14 . Amongst other features, the Data Service System 24 has the ability to be scaled according to the number of clients using internet service and the required speed or bandwidth of the internet service. The Data Service System 24 can be supplied through a separate device or integrated into the Satellite Receiver. The devices may be able to provide Quality of Service (“QoS”) to insure the quality of the video.
As stated above, the Mini-Headend unit 12 may contain the Gigabit QoS Ethernet Switch 28 to provide connectivity between the Core Video Services System 18 , the Advanced Video Services System 22 , the Data Services System 24 , and the MxU network 14 . While the Gigabit QoS Ethernet Switch 28 may be needed for medium to large systems, it may be removed in small installations. The Gigabit QoS Ethernet Switch 28 supports full-duplex Gigabit Ethernet interfaces and is scalable to support systems of various sizes. The Gigabit QoS Ethernet Switch 28 may also support a QoS standard as set forth in the IEEE 802.1p and 802.1q standards. The QoS standard can facilitate communication between the Gigabit QoS Ethernet Switch 28 , the Core Video Services System 18 , the Advanced Video Services System 22 , and the Data Services System 24 by giving a higher priority to video data than internet data from the Data Service System 24 . For example, when video data and internet data are simultaneously requested, video data is transmitted first and the internet data is delayed until sufficient bandwidth becomes available. The type of services being provided and the number of dwelling units 16 that are in the MxU network 14 are a few of the many factors that one of ordinary skill in the art must consider in selecting the Gigabit QoS Ethernet Switch 28 .
The MxU network 14 also can include one or more service racks 34 . The service rack 34 is scalable according to the number of the dwelling units 16 in the MxU network 14 . In the one embodiment of the invention, the service rack 34 is located where the phone lines in the MxU network 14 come together. The number of MxU networks 14 in the digital data system 10 dictates the number of the service racks 34 that are required. Preferably, one of the service racks 34 is provided for each of the MxU networks 14 (e.g., buildings) in a multi-network environment (e.g., a multiple building complex). Each of the service racks 34 may include a VDSL switch 36 that uses a Plain Old Telephone Service (“POTS”) Splitter 38 to combine POTS service 40 with the digital video, audio, and data received from the Gigabit QoS Ethernet Switch 28 of the Mini-Headend 12 . Although the VDSL switch 36 is illustrated as being an Ethernet Quadrature Amplitude Modulation (“QAM”) switch, any other appropriate switch is considered within the scope of the present invention.
In the digital data system 10 , each of the dwelling units 16 may include a modem 42 , a Network Set Top Box (“NSTB”) 44 , both the modem 42 and the NSTB 44 , or an integrated modem and NSTB unit. One example of the NSTB 44 is a DirecTV set top box that has been configured to interface with the Mini-Headend unit 14 . The modem 42 is one example of a device that may be used by the NSTB to access digital data, audio, and video services. The modem 42 may be connectable to the VDSL switch 36 via phone lines and can terminate the VDSL line. The modem 42 may also have a POTS Splitter and a connection for phone services 46 . The modem 42 may also have an Ethernet port to provide one or more computers 48 access to the internet in addition to providing the NSTB 44 access to audio, video, and data services.
Although phone lines are shown in FIG. 1 the communication medium between the dwelling units 16 , the service rack 34 , and the Mini-Headend unit 12 , other appropriate forms of networking, including cable and wireless networks, are considered within the scope of the invention.
An important component of the architecture of FIG. 1 is the capability of remote tuning. Remote tuning removes the satellite tuning functions from the NSTB 44 and transfers them to the Mini-Headend unit 12 . In the embodiment shown in FIG. 1 , the tuning function takes place within the Satellite Receiver System 19 . The transfer of the tuning function, which may include tuning, demodulation, and demultiplexing, to the Mini-Headend unit 12 permits the network to operate on less bandwidth because only a limited subset of data that the Satellite Receiver System 19 actually receives is transmitted to the NTSB 44 .
In operation, when the remote tuning function in the Satellite Receiver System 19 receives a request from a NSTB 44 , it processes the request and connects to a satellite transponder. Because the transponder data rate usually exceeds the bandwidth of the network between the Satellite Receiver System 19 and the NSTB 44 , the data must be filtered. One embodiment of a filter in the present invention filters the transport streams by Packet Identifier (“PID”). In this case, the NSTB 44 request may include PIDs of interest. The filtering process reduces the data rate down by extracting only the streams with requested PIDs. This reduced data rate should not exceed the bandwidth limit of the network. It should be noted that as the number of NSTBs 44 on the network increases, the number of tuners available for each NSTB may decrease because the NSTBs can share the Satellite Receiver System's tuners.
Another aspect of the architecture of FIG. 1 is the ability to synchronize the MxU network clock to the A/V data signal provider's system clock. As described above, the Satellite Receiver System 19 receives broadcast audio/video (A/V) data signals. These signals are composed of transport packets, and some of these transport packets contain an embedded time stamp from the broadcast system. The embedded time stamp can be used for buffer and color burst control. The Satellite Receiver System 19 converts the transport packets to IP data signals for the NTSBs. In this process jitter is introduced, and the original system clock-information is lost. Because the Satellite Receiver System 19 is capable of tuning to multiple transponders and receiving multiple video channels, each of which may have a unique system clock, unique clock jitter can be introduced to every channel. The Satellite Receiver System 19 ′ can be modified to remove the jitter introduced by the conversion process and thus provide a jitter free time base for the NSTBs.
FIG. 2 is a block diagram of a Satellite Receiver System in accordance with embodiments of the present invention and is designated using a reference numeral 50 . A precision local clock (“PLC”) 51 may be adapted to time stamp only specific network packets. Using the PLC 51 and a time compensation algorithm, accurate time stamps for a given A/V data signal can be applied to the packets of an outgoing IP data signal. Among the advantages of this method is that it only requires one system clock on the Satellite Receiver System 50 and does not require an actual phase lock clock per video channel. For a DirecTV satellite system, the frequency of the PLC 51 should be no slower than 27 MHz. It should be noted that a faster clock may reduce the computation error.
A satellite feed 56 is received by a plurality of tuner/demodulators 57 a - 57 c . Each of the tuner/demodulators 57 a - 57 c corresponds to a different received channel. The output of each of the tuner/demodulators 57 a - 57 c is delivered to a corresponding receive time stamp latch (“RTSL”) 52 a - 52 c . The PLC 51 is adapted to function as a source clock to the plurality of receive time stamp latches 52 a - 52 c.
Each of the RTSLs 52 a - 52 c adds a time stamp onto every A/V data signal transport packet as it is received. A Packet Processor 53 is configured to detect the packets within the A/V data signal that have the embedded time stamp. This configuration may be based on PID/SCID, packet type or the like. The Packet Processor 53 saves the RTSL 52 and the broadcast A/V stream embedded time stamp (“SCR”) and has the ability to process the two time stamps to create a normalized clock rate as shown in Equations 1,2, and 3. Normalizing the Broadcast System Clock to the PLC provides a time adjustment factor (“TAF”).
Broadcast A/V Stream Clock Delta:
ΔSCR=SCR n −SCR n−1 , n> 0 Equation 1
Precision Local Clock Delta:
Δ RTSL=RTSL n −RTSL n−1 , n> 0 Equation 2
Normalizing the Broadcast System Clock to the PLC provides a time adjustment factor (TAF):
TAF
=
Δ
SCR
Δ
RTSL
Equation
3
The principal behind applying time stamps to IP packets is to allow multiple devices on a network to synchronize their clocks with a sender or server. There are several network protocols that may be used to apply time stamps. In one network protocol, the time stamps are not applied at the physical layer. This protocol requires the use of statistical methods to remove the jitter introduce after a time stamp has been applied to the packet and before the packet is put on the physical network. These statistical methods are known to one skilled in art, and will not be discussed in detail. Another network protocol involves applying the time stamp to the network packet at the physical layer. In this method, assuming that the delay path between the sender and receiver is constant, the jitter that is introduced by the system can be removed if the receiving device also applies a time stamp at the physical layer and then synchronizes its clock to the sender's clock.
The following discussion relates to how the sender applies an accurate time stamp to a network packet. The Satellite Receiver System 50 has several options to transmit IP data signal time stamp packets. One option is to use standard protocols, such as NTP, RTP and the like. Another option is to create a new transport packet with the correct timing information in same format as the A/V data signal time stamp. Either implementation requires the Satellite Receiver to apply the correct time stamp for a targeted video channel. One way to do this is to apply the time stamp to the IP data signal time stamp packet as it is being transmitted onto a physical, network 55 . In this embodiment, a local counter using the PLC 59 latches a network time stamp (“NTS”) that is applied to an IP data signal time stamp packet. Because the NTS is not synchronized with the embedded time stamp from the A/V data signal, it can be adjusted as shown in Equation 4 to produce a Corrected Network Time Stamp (“CNTS”). Because the CNTS has been adjusted by the TAF from Equation 3, it is synchronized with the embedded time stamp in the A/V data signal. The result is a system that does not require multiple voltage controlled crystal oscillators (“VCXOs”), and applies an accurate jitter free time stamp to the IP data signal time stamp packet.
Corrected Network Time Stamp (CNTS):
CNTS=NTS×TAF Equation 4
The method described above is for an ideal system in which the PLC 51 does not drift and there are no calculation errors in the CNTS. There are several methods that can be used to minimize the effects of clock drift and calculation errors in a non-ideal system. First, it will reduce errors if the PLC is an accurate crystal with drift less than +−10 parts per million (“ppm”). Next, since the Satellite Receiver System determines when a network time stamp packet is sent, the TAF can be averaged over only that period of time to provide a more accurate CNTS. This window average, called the Altered CNTS (“ACNTS”) is shown in Equation 5.
Altered CNTS (ACNTS);
ACNTS = NTS × ∑ k = n N ( SCR k - SCR n ) ∑ k = n N RTSL k - RTSL n , Equation 5
where:
n is the first unused sample N is the latest sample, a sample is taken when the time stamps are detected in the transport stream
Equation 5 can be further simplified by controlling how the time stamps are collected. If this is done, Equation 5 becomes:
ACNTS = NTS × SCR N - SCR n RTSL N - RTSL n , Equation 6
as long as register overflow and counter wrap around are compensated.
There are several different network time stamp protocols, such as NTP, RTP and the like. These protocols generally require the CNTS or ACNTS values to be calculated by the sending unit, in this case the Satellite Receiver System 50 . Thus, in one embodiment, the Satellite Receiver System calculates one ACNTS per video channel. In another embodiment, the system uses a transport packet or a property packet to pass the ACNTS parameters to the client or receiver which performs the ACNTS calculation.
FIG. 3 is a block diagram an embodiment of a transport packet that may be used for passing the parameters for the Altered Corrected Network Time Stamp (“ACNTS”) in accordance with embodiments of the present invention and designated using a reference numeral 60 . The packet 60 may comprise an IP header, a UDP header, a transport header, a network time stamp (“NTS”), an SCR N , an SCR n , an RTSL N and an RTSL n . The embodiment illustrated in FIG. 3 may reduce the processing requirement of the Satellite Receiver by requiring the NSTB to calculate the ACNTS for each channel that it is using. The Satellite Receiver System may still insert the NTS, but the rest of the packet's parameters need not be applied to the network packet until the packet is actually sent. The NSTB calculates the ACNTS using equation 5 or 6 when it receives the packet.
The system outlined above may comprise a clock recovery scheme for a system that provides an accurate time stamping of packets at the endpoints of a network (the Satellite Receiver System and the NSTB). This system may reduce the clock jitter introduced by intermediate network devices such as off-the-shelf Gigabit and Ethernet QAM switches. It should be noted, however, that inserting the time stamp as the network time stamp packet is placed onto the network may require additional hardware and costs. For this reason, another embodiment of this invention is a system that produces little or no jitter. Such a system may be referred to as a jitterless MxU system.
FIG. 4 is a block diagram of a network in which embodiments of the present invention may be employed. The diagram is generally referred to by the reference numeral 80 . Removing component jitter is primarily based on knowing the clock relationships between two physically connected network devices. For example, in the system 80 , there are N network devices that are connected to each other. Each network device has its own clock and it is desired to synchronize device N's 85 clock to device A's 81 clock.
Because this system 80 does not restrict the device N's 85 ability to synchronize to any other device, the device N's first task may be to synchronize its clock to any of the other devices in the system. To allow this flexibility, the two network devices that are synchronizing may establish a clock relationship between themselves. Because N is the endpoint in system 80 , the clock relationship from left to right will be CA/CB, CB/CC, CC/CD, and so on, where CA is the clock in the device A, CB is the clock in device B and so on. The clock relationship is established by sending time stamped network packets to a related device. For example, the device A 81 sends a time stamp packet to the device B 82 . The device A 81 applies the time stamp just before the packet is put on the physical network. The arrival time for the packet to reach the device B is delayed by the constant C AB . The device B uses it local clock to capture the arrival time of the network packet from the device A. After receiving two of these packets, the device B can calculate the clock relation between the devices A and B (CA/CB), as shown in Equation 7.
CA
/
CB
=
CA
n
-
CA
n
-
1
CB
n
-
CB
n
-
1
Equation
7
Once all the clock relationships in system 80 are known, the system 80 can synchronize the device N's clock to the device A's clock. In order to achieve clock synchronization the receiver (the device N 85 ) needs at a minimum two clock recover packets from the sender (the device A 81 ). Even though the physical wire between the two devices is considered a fixed delay, the delay between each device is not necessarily fixed. The objective is to compensate for delay that's introduced by each device and to quantify the unit delays in the sender's (A) clock units.
The device A sends a clock recovery network packet to the device N. This packet may be a modified IP time stamp packet as discussed above. Two fields are added to the packet, clock rate and delay ticks. “Clock rate” defines the clock ratios as the packet goes through the system. “Delay ticks” is accumulation of delays for each device in the sender's tick units. When the device A sends a clock recovery packet to the device N, the clock recovery packet initially has the clock rate set to 1 and the delay ticks to 0.
FIG. 5 is a block diagram of an alternative network configuration in which embodiments of the present invention may be employed. The diagram is generally referred to by the reference numeral 90 . The packet Is time stamped by device A and sent to device B. The device B captures the arrival time of the packet and determines where to route the packet and any processing that is required. When the packet is ready to be transmitted, the device B recognizes that the packet is a clock recovery packet and captures a departure time. The device B then computes the delay between the time stamps (see Equation 8) and multiples them by CA/CB (see Equation 9). This result is then added to the “delay ticks” in the clock recovery packet, and the “clock rate” from the packet is multiplied by CA/CB and then written back into the clock recovery packet. This process is repeated at each network device until the packet is received by the device N. This process is shown mathematically in Equations 10, 11, and 12. Equation 13 shows how to determine the overall clock error between the device A and the device N.
The delay for B:
t b =DepartureTime−ArrivalTime, Equation 8
units are in B's clock
The delay for B in A's clock units:
tA b = CA CB × t b Equation 9
Clock Ratio though the system
ClockRatio = CA CB × 1 + ( CA CB ) CB CC c + ( CA CB CB CC ) CC CD × … × … Equation 10
The variable delay through the system in A's clock units (delay ticks)
DelayTicks = CA CB × t b + ( CA CB ) CB CC × t c + ( CA CB CB CC ) CC CD × t d + … + …
Therefore : ( Equation 11 ) DelayTicks = ∑ k = B m ( t k × ∏ n = B k C n - 1 C n ) ,
m is the last device before N Equation 12 Clock Error = [ 1 - ( ( ACTS n + DelayTicks n ) - ( ACTS n - 1 + DelayTicks n - 1 ) ArrivalTime n - ArrivalTime n - 1 ) ] × 1 ⅇ - 6 , ( ppm ) ( Equation 13 )
Equation 13 does not have to be used to adjust N's clock. It is the clock error in parts per million (ppm).
The device N receives the clock recovery packet and captures the arrival time. The information in the packet and the arrival time are saved. Once a second clock recovery packet is received, the device N can synchronize its clock to A's clock using the respective arrival times and the information in the recovery packets.
FIG. 6 is a block diagram of a clock recovery packet in accordance with embodiments of the present invention. The clock recovery packet is generally referred to by the reference numeral 100 . The clock recovery packet 100 comprises an ACTS, a clock rate component and a delay ticks component.
Turning now to FIG. 7 , a block diagram of a device that performs clock jitter removal in accordance with embodiments of the present invention is illustrated. The diagram is generally referred to by a reference numeral 120 . A standard router and switches will not perform the time stamping and packet modification required for a jitterless MxU network. The network 120 requires a precision-clock 121 with little error. This clock is shared by a plurality of packet discriminators 122 and can be used by a packet processor 123 . The packet discriminators 122 are connected to the physical ports 124 and are capable of time stamping incoming and outgoing packets.
FIG. 8 is a block diagram of a packet discriminator in accordance with embodiments of the present invention. The packet discriminator is generally referred to by the reference numeral 130 . When a packet arrives, it is time stamped, and the time stamp is saved with the packet. As the packet is being transmitted through physical port 131 , a discriminator 132 scans the packets for a clock recovery packet. If a packet of this type is detected, the discriminator 132 captures a time stamp 133 . The discriminator then uses the previous and current time stamps to compute the new “delay ticks” and “clock ratio”, which are written back into the packet. The checksum and cyclic redundancy code (“CRC”) are computed, and the packet is transmitted.
While the invention may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. However, it should be understood that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the invention as defined by the following appended claims.
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The disclosed embodiments relate to a system for providing remote tuning and clock synchronization in a network. The system includes a device that receives a signal that includes a plurality of channels, a device that receives a user request indicative of a desire to view at least one of the plurality of channels, and a filter that filters the received signal and transmits a user signal corresponding to the at least one of the plurality of channels to the user. An alternative embodiment of the system includes a device that receives a signal that includes a plurality of packets, at least a portion of the plurality of packets comprising an embedded time stamp, a device that detects the at least a portion of the plurality of packets containing the embedded time stamp, and a device that computes an adjusted time stamp based on the embedded timestamp and a precision local clock and incorporates the adjusted timestamp into the at least a portion of the plurality of packets containing the embedded timestamp prior to transmitting the at least a portion of the plurality of packets to the network.
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FIELD OF THE INVENTION
The present invention relates to the field of circuit breakers, and more particularly to multipole circuit breakers in which contact sets are paralleled in order to increase breaker capacity rating.
BACKGROUND OF THE INVENTION
In the field of electrical circuit breakers, it is well known to tie the mechanisms of a plurality of electrical poles, or independent circuit paths, together. In this case, it is often desired to provide a single control lever and a trip mechanism which operates the electrical contacts in synchrony. See, U.S. Pat. Nos. 5,565,828; 5,557,082, 4,492,941, and 4,347,488, expressly incorporated herein by reference.
A single pole circuit breaker is a device that serves to interrupt electrical current flow in an electrical circuit path, upon the occurrence of an overcurrent in the circuit path. On the other hand, a multipole circuit breaker is a device which includes two or more interconnected, single pole circuit breakers which serve to substantially simultaneously interrupt current flow in two or more circuit paths upon the occurrence of an overcurrent in any one circuit path.
In a multipole circuit breaker, typically the poles switch independent phases of AC current. Thus, two-pole and three-pole breakers are well known. In these systems, each pole is provided with a current sensing element to generate a trip signal, so that an overload on any phase circuit is independently sensed. In the event that an overload occurs, all of the phase circuits are tripped simultaneously. A manual control lever is provided which operates the phase circuits synchronously as well.
Conventional multipole circuit breaker arrangements thus include a trip lever mechanism associated with each pole of the multipole circuit breaker. Each trip lever includes a portion for joining it to adjacent trip levers. If any pole is tripped open by an overcurrent, the breaker mechanism of that pole causes the trip lever to pivot about its mounting axis. The pivotal motion of one lever causes all the interconnected trip levers to similarly pivot. Each lever may include an arm for striking the armature or toggle mechanism of its respective pole, and causing each pole to be tripped open.
In order to increase the capacity of a circuit breaker system, it has been proposed to parallel a set of contacts, each of which might be insufficient alone to handle the composite load. Thus, by paralleling two single pole circuit breaker elements, a higher capacity circuit breaker may be achieved. However, the art teaches that, preferably, a single contact set is provided having a larger surface area and greater contact force in order to handle a larger load. These larger load-handling capacity devices are typically dimensionally larger than lower load carrying designs. This is because, in part, many elements within a circuit breaker scale in size in relation with current carrying capacity, including the lugs, trip elements, trip mechanism, contacts and breaker arm.
In designing a trip element or system, the type of load must be considered. There are two main classes of trip elements; thermal magnetic and magnetohydraulic. These differ in a number of characteristics, and typically have different application in the art.
However, where such contact parallelization is employed, the contact ratings of the breaker should be derated from the sum of current carrying capacity of each of the contact sets. This is because a contact set having a lower impedance than others will "hog" the current, and may thus see a significantly greater proportion of the total current than 50%, resulting in overheating, and possible failure. Therefore, the art typically teaches that a pair of paralleled contact sets are derated, by for example about 25%, to ensure that each component will operate within its safe design parameters. Further, the contact resistance of a switch may change significantly with each closure of the switch. In parallel contact systems, it is known to employ both unitary thermal magnetic and multiple parallel-operating trip elements in multipole breakers. Thus, it is possible to design a circuit breaker with a specially designed trip element that controls an entire breaker system, or to parallel two entire breaker circuits of a multipole arrangement. In the later case, in order to equalize the current as much as possible between the circuits, a current equalization bar has been proposed. However, this does not compensate for unequal contact resistance, and nuisance tripping of the circuit breaker results when the unequal division of the current has caused enough current to pass through one of the current sensing devices to cause it to trip its associated mechanism.
Attempts have been made in thermal-type breakers to parallel the sets of contacts of a multipole breaker to achieve increased maximum current rating. In one case, exemplified by model QO12150 from Square-D Corp., a unitary thermal magnetic trip element was employed as a trip element for a set of two parallel contact sets, with a connecting member to trip both contact sets at the same time. In this case, the trip dynamics were defined by the thermal-magnetic trip element, and careful calibration of the thermal element was required. This design provided both contact sets within a common housing. Thus, while the internal parts were common with nonmultipole arrangements, the housing itself was a special multipole breaker housing. The parallel breaker is housed in a shell that differs from single pole housings, with the parallel poles in a common space.
One typical known system is disclosed in U.S. Pat. No. 4,492,941, expressly incorporated herein by reference, provides electromagnetic sensing devices that are electrically connected at one of their ends to the load terminals. The load terminals are electrically connected in parallel with each other. A plurality of electromagnetic sensing devices are electrically connected at their other ends to each other and are electrically connected to all of the movable contacts which are themselves all electrically connected together. The stationary contacts are connected to line terminals that are also electrically connected in parallel with each other. Thus, the electromagnetic sensing devices are connected in parallel at both of their ends and the contact sets are also connected in parallel at both of their electrical ends, while the electromagnetic sensing devices, on the one hand, and the contact sets, on the other hand, are also in series with each other, thus seeking to equally divide the current among all of the electromagnetic sensing devices, even though the current may not be equally divided among all of the relatively movable contacts, because of varying contact resistances.
Another attempt to increase current carrying capability by paralleling contact sets using magnetohydraulic trip elements employed two parallel trip elements, each set for a desired derated value corresponding to half of the total desired current carrying capacity. For example, two 100 Amp breakers were paralleled (using a standard multipole trip bar) to yield a 150 Amp rated breaker, with 175% trip (about 250 Amps) rating, meeting UL 1077. The parallel set of breakers employed two side-by-side single breaker housings, with slight modifications, and thus did not require new tooling for housings and contact elements.
In this later case, it is difficult to comply with UL 489, which requires that the breaker trip at 135% maximum of rated capacity and 200% of rated capacity within 2 minutes, and that the breaker be capable of handling the specified loads without damage. For example, if the maximum expected deviation in contact resistance of the contact sets (which changes each time the contact is closed) could cause a current splitting ratio of 60%/40%, then in order to ensure reliable trip at 135% of total rated capacity, each trip element must be designed to trip at about 120% of rated capacity, which would lead to unreliability and nuisance trips because of insufficient margin.
Notwithstanding the foregoing attempts, it has heretofore been considered difficult to employ magnetohydraulic circuit breakers in parallel contact multipole breakers with relatively low overcurrent thresholds, such as that imposed by UL 489, especially for use in load environments with high peak to average load ratios, because the maximum expected currents would result in nuisance trips.
A main advantage of parallel contact circuit breakers is that these may employ many parts in common with lower current carrying single pole devices. It is thus often economically desirable to increase the current carrying capacity of circuit breakers by modifying as little as possible, existing circuit breakers. Toward this end, it has been proposed that the amount of current carrying capacity may be almost doubled by placing two single pole circuit breakers side-by-side (or almost tripled by using three side-by-side) and connecting the line terminals together and likewise connecting the load terminals together.
Commercial circuit breaker manufacturers generally manufacture a complete product line composed of a number of breaker sizes, each one covering a different (although sometimes overlapping) operating current range. Each breaker size typically has required its own component and case sizes. In general, each component and case size combination is useful in circuits having only a single current rating range. The need to have a different set of component and case sizes for each current rating has added to the overall cost of breakers of this general type.
As discussed above, there are two common types of trip elements for circuit breakers. A first type, called a thermal magnetic breaker, provides a thermal portion having a bimetallic element that responds to a heat generated by a current, as well as a solenoid to detect magnetic field due to current flow. Typically, the thermal element is designed to trigger a trip response at a maximum of 135% average of rated capacity, and the magnetic element responds quickly (within milliseconds) at 200% of rated capacity. The thermal portion of the breaker controls average current carrying capability, by means of thermal inertia, while the magnetic element controls dynamic response. This design seeks to provide adequate sensitivity while limiting nuisance trips. However, such thermal magnetic designs typically require calibration of the thermal trip mechanism for precision, and tuning of dynamic response is difficult. Further, the thermal element incurs a wattage loss. The operation of the thermal element is also sensitive to ambient temperature, since the heating of the bimetallic element by the current flow is relative to the ambient temperature. See, U.S. Pat. Nos. 3,943,316, 3,943,472, 3,943,473, 3,944,953, 3,946,346, 4,612,430, 4,618,751, 5,223,681, and 5,444,424.
A second type of trip element is called a magnetohydrodynamic or magnetohydraulic breaker. See, U.S. Pat. Nos. 4,062,052 and 5,343,178. In this element, the current passes through a solenoid coil wound around a plastic bobbin, acting on static pole piece and a movable armature. Within the solenoid coil is a moveable magnetically permeable core, which is held away from the pole piece in a damping fluid, e.g., a viscous oil, by a spring. As a static current through the coil increases, the core is drawn toward the pole piece through the viscous fluid, resulting in a nonlinear increase in force on the armature, which lies beyond the pole piece, as the moveable core nears contact with the pole piece. Thus, as the moveable core is pulled toward the pole piece, the magnetic force on the armature suddenly increases and the armature rapidly moves. In this case, it is primarily the spring constant of the spring which controls the precision of the trip element, and thus a final calibration is often unnecessary given the ease of obtaining precision springs. In the event of a dynamic current surge, the core is damped by the fluid, and thus does not rapidly move toward the pole piece, resulting in a dynamic overload capability, determined by the viscosity of the damping fluid, and thus avoiding nuisance trips. The armature is typically counterbalanced and may be intentionally provided with an inertial mass to provide further resistance to nuisance trips.
Nuisance tripping is a problem in applications where current surges are part of the normal operation of a load, such as during motor start-up or the like. For example, starting up of motors, particularly single phase, AC induction types, may result in high current surges. Motor starting in-rush pulses are usually less than six times the steady state motor current and may typically last about one second, but may be 10 or more times the steady state current. In the later case, a breaker may revert to an instantaneous trip characteristic, because the magnetic flux acting on the armature is high enough to trip the breaker without any movement of the delay tube core or heating of the thermal element, depending on the design. One way to address this problem is by increasing the distance between the coil and armature.
A second type of short duration, high current surge, commonly referred to as a pulse, is encountered in circuits containing transformers, capacitors, and tungsten lamp loads. These surges may exceed the steady state current by ten to thirty times, and usually last for between two to eight milliseconds. Surges of this type will cause nuisance tripping in conventional delay tube type electro-magnetic circuit breakers. This problem may be addressed by increasing the inertia of the trip element or by other means. See, U.S. Pat. Nos. 4,117,285, 3,959,755, 3,517,357, and 3,497,838, expressly incorporated herein by reference.
SUMMARY AND OBJECTS OF THE INVENTION
The applicants have found that a single magnetohydraulic trip element can advantageously be used to provide desired trip dynamics in a circuit breaker by passing all current from a set of parallel contact sets through a unitary trip element, and providing a multipole trip arm triggered by the unitary trip element which trips the parallel contact sets simultaneously.
The preferred design employs parallel circuit breaker poles each having a trip mechanism, switch contacts and a housing, which share most components in common with a single pole circuit breaker in the same "family", thus reducing required number of inventoried parts and engineering costs. The trip element of the preferred design, however, differs from single pole designs, being configured for the desired ratings and dynamic response, and portions of the housing between adjacent poles are modified for common access to electrical terminals to bridge the load and to provide a standard type multipole trip bar. The magnetohydraulic trip element, which is preferably a 150 Amp element with desired dynamic trip characteristics, sits asymmetrically in one of the pole housings within a standard frame, in the normal trip element position, and actuating a standard armature.
The external lugs of each poles are made electrically parallel by placing a conductive bar therebetween. This also serves the visual function of alerting the installer as to the electrical function of the breaker, which is similar to a multipole breaker that is not paralleled. Internally, one set of lugs are connected together with conductive straps to one end of the magnetic coil. The other end of the magnetic coil is connected with conductive straps to each of the contact arms. In order to provide physical access for these connections, a portion of each of the common walls of the breaker pole housings are machined to form an aperture or portal therebetween.
The modifications to the standard single pole housing are minimized; other than the portal in the common wall between the poles, the only other modifications are, for example, an arcuate slot for a common trip mechanism, and an arcuate slot for an internal linkage of the manual switch handles. In the preferred embodiment, however, the handles are linked externally by a crossbar, which fits between the handles and causes them to move in unison. In this way, the standard mountings for the handle, pivot axis of the moveable contact bar, stationary contact, and arc chute and slot motor are unaffected. Further, the safety factors of the design remain relatively intact.
A preferred design provides two parallel switch poles with a design rating of 100 Amps each, in a housing 2.5 inches long, 0.75 inches wide, and 2 inches deep, with electrical contact bolts on 2 inch centers. The resulting parallel multipole design with a rating of 150 Amps therefore fits within a form factor of 2.5 by 1.5 by 2 inches, a substantial improvement over prior 150 Amp rating circuit breakers.
It should be seen that the form factor may be varied according to the present invention, for example other standard size circuit breakers which may be formed as multipole parallel contact breakers are, for example, 2 inches long, by 0.75 inches wide, by 1.75 inches deep (e.g., 50 Amp rating) and 7.25 inches long by 1.5 inches wide by 3 inches deep (e.g., 250 Amp rating).
The present invention may incorporate other known circuit breaker features, such as a mid-trip stop for the manual control lever or other trip indicators, and indeed may be formed into a traditional multipole design with parallel sets of contacts for each of multiple switch poles.
It is also seen that, while the preferred embodiments employ housing parts which are common in essential design with single pole designs, that this is not a limitation on the operability of the inventive design.
It is therefore an object of the invention to provide a magnetohydrodynamic circuit breaker which has a low average overcurrent trip capability with good nuisance trip immunity.
It is also an object of the present invention to provide a circuit breaker having a high current rating and a small form factor.
It is a further object of the invention to provide a circuit breaker having a set of parallel contacts, driven by a trip mechanism, wherein all of the contact sets are tripped by a common magnetohydrodynamic trip element.
These and other objects will be apparent from an understanding of the preferred embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
These and further objects and advantages of the invention will be more apparent upon reference to the following specification, claims and appended drawings wherein:
FIG. 1 is a side view of a single pole breaker mechanism having a housing half removed;
FIGS. 2A and 2B are detail views of a known breaker toggle mechanism;
FIG. 3A is an exploded view of a parallel pole master/slave circuit breaker of a slightly different base design than FIG. 1;
FIG. 3B shows a cutaway view of a delay tube shown in FIG. 3A
FIGS. 4A and 4B shown, respectively, an exploded view of a housing structure, and a side view of an inner case half, for the master/slave circuit breaker according to FIG. 3A; and FIG. 4C shows a partial assembly drawing of exploded view 4A, with a gap between the master housing and slave housing, revealing the electrical and mechanical connections between interconnecting the respective housings.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The preferred embodiments will no be described by way of example, in which like reference numerals indicate like elements.
EXAMPLE
Components of a conventional type single pole circuit breaker are depicted in FIGS. 1, 2A and 2B. See, U.S. Pat. No. 5,293,016, expressly incorporated herein by reference. As shown, the single pole circuit breaker 10 includes an electrically insulating casing 20 which houses, among other things, stationary mounted terminals 30 and 40. In use, these terminals are electrically connected to the ends of the electrical circuit that is to be protected against overcurrents.
As its major internal components, a circuit breaker includes a fixed electrical contact, a movable electrical contact, an electrical arc chute, a slot motor, and an operating mechanism. The arc chute is used to divide a single electrical arc formed between separating electrical contacts upon a fault condition into a series of electrical arcs, increasing the total arc voltage and resulting in a limiting of the magnitude of the fault current. See, e.g., U.S. Pat. No. 5,463,199, expressly incorporated herein by reference. The slot motor, consisting either of a series of generally U-shaped steel laminations encased in electrical insulation or of a generally U-shaped, electrically insulated, solid steel bar, is disposed about the contacts to concentrate the magnetic field generated upon a high level short circuit or fault current condition, thereby greatly increasing the magnetic repulsion forces between the separating electrical contacts to rapidly accelerate separation, which results in a relatively high arc resistance to limit the magnitude of the fault current. See, e.g., U.S. Pat. No. 3,815,059, incorporated herein by reference.
The trip mechanism includes a contact bar, carrying a movable contact of the circuit breaker, which is spring loaded by a multi-coil torsion spring to provide a force repelling the fixed contact. In the closed position, a hinged linkage between the manual control toggle is held in an extended position and provides a force significantly greater than the countering spring force, to apply a contact pressure between the moveable contact and the fixed contact. The hinged linkage includes a trigger element which, when displaced against a small spring and frictional force, causes the hinged linkage to rapidly collapse, allowing the torsion spring to open the contacts by quickly displacing the moveable contact away from the fixed contact. The trigger element is linked to the trip element.
As is known, the casing 20 also houses a stationary electrical contact 50 mounted on the terminal 40 and an electrical contact 60 mounted on a contact bar 70. Significantly, the contact bar 70 is pivotally connected via a pivot pin 80 to a stationary mounted frame 100. A helical spring 85, which encircles the pivot pin 80, pivotally biases the contact bar 70 toward the frame 100 in the counterclockwise direction per FIG. 1. A contact bar stop pin 90 or contact bar stop mounted on the contact bar 70 (or optionally other stop, such as a surface which contacts the frame), limits the pivotal motion of the contact bar 70 relative to the frame 100 in the non-contacting position (contact bar 70 rotated about pin 80 in the counterclockwise direction to separate contacts 50 and 60, not shown in FIG. 1). By virtue of the pivotal motion of the contact bar 70, the contact 60 is readily moved into and out of electrical contact with the stationary contact 50. In the contacting position (shown in FIG. 1), the stationary contact 50 limits the motion of the contact 60, thus limiting the angular rotation of the contact bar 70 about pin 80. The pivot pin 80 sits in a conforming aperture in the frame, while a slot 81 is provided in the contact bar 70 to allow a small amount of vertical displacement. Thus, in the contacting position, the contact bar 70 may be displaced vertically by the pressure of the toggle linkage composed of cam link 190 and link housing 200 in the aligned relative orientation (shown in FIG. 1), against a force exerted by the helical spring 85.
An electrical coil 110, which encircles a magnetic core 120 topped by a pole piece 130, is positioned adjacent the frame 100. An extension 140 of the coil material, typically a solid copper wire, or an electrical braid, serves to electrically connect the terminal 30 to one end of the coil 110. An electrical braid 150 connects the opposite end of the coil 110 to the contact bar 70. Thus, when the contact bar 70 is pivoted in the clockwise direction (as viewed in FIG. 1), against the biasing force exerted by the spring 85, to bring the contact 60 into electrical contact with the contact 50, a continuous electrical path extends between the terminals 30 and 40.
Magnetic core 120 includes a delay tube. By way of example only, the coil and delay tube assembly may be of the type shown and described in U.S. Pat. No. 4,062,052, expressly incorporated herein by reference. Magnetic core 120 has at an upper position thereof, a pole piece 130. Adjacent pole piece 130 is an armature 260 pivotally mounted on a pin 261 secured to frame 100. Armature 260 is rotatably biased in a clockwise direction (relative to FIG. 3) by a spring (not shown), and comprises an arm 265 and a counterweight 266. Counterweight 266 comprises an enlarged extension of armature 260, and may include a slot 267 for receiving a pin of an inertia wheel rotatably mounted on frame 100, not shown. See, U.S. Pat. Nos. 3,497,838, 3,959,755, 4,062,052, and 4,117,285, expressly incorporated herein by reference.
The delay tube of the magnetic core 120 is a typical design, which is disclosed, for example, in U.S. Pat. No. 4,062,052, expressly incorporated herein by reference. In this design, an outer tube 122 of the magnetic core 120 is supported in the frame 100 by a bobbin 121, about which the coil 110 is wound. The outer tube is a drawn single piece shell, sealed at its open end by the pole piece 130. The interior of the delay tube is conventionally filled with a viscous fluid 123 such as oil. Typically, the viscosity of the oil is selected to provide a desired damping within a standard delay tube design, although mechanical modifications, most notably with respect to the clearance around a magnetic delay core 124 (not shown in FIG. 1) or slug in the outer tube 122, will also influence the damping or delay of the system. The construction materials of the magnetic delay core or slug and pole piece 130 may also alter the force induced by the coil 110. The delay core or slug is biased away from the pole piece 130 by a helical spring 125 provided within the outer shell 122. For example, the delay core has an enlarged lower end and a reduced diameter upper end around which a portion of spring passes and defining an annular shoulder against which the lower end of spring bears. In conventional circuit breaker delay tubes, the distance from the bottom of the core to the plane containing the bottom of the coil 110, is customarily chosen to be about one-third of the overall interior distance of the delay tube, namely from the bottom of the core to the underside of the pole piece 130. Customarily, the coil 110 surrounds the upper two-thirds of the delay tube outer shell 122. This conventional construction optimizes the delay function of the tube while, at the same time, maintaining the overall length of the tube within reasonable bounds.
When a prolonged overcurrent passes through coil 110, delay core moves upwardly in the outer shell 122, with motion damped by the viscous oil, to compress spring until the upper end of delay core engages pole piece 130, causing an increased magnetic flux in the gap between the pole piece.130 and armature 260, so that the armature 260 is attracted to the pole piece 130 and rotates about its pivot 261 to engage the sear striker bar 240 to result in collapse of the toggle mechanism, separating the electrical contacts and opening the circuit in response to the overcurrent, as will become apparent below.
The circuit breaker 10 also includes a handle 160, which is pivotally connected to the frame 100 via a pin 170. Handle 160 includes a pair of ears 162 with apertures for receiving a pin 180, which connects handle 160 to a cam link 190. In addition, a toggle mechanism is provided, which connects the handle 160 to the contact bar 70. The handle 160 is provided with a helical spring 161, which applies a counterclockwise force on the handle 160 about pin 170 with respect to frame 100. A significant feature of the cam link 190, shown in expanded view in FIG. 2B, is the presence of a step, formed by the intersection of non-parallel surfaces 194 and 198, in the outer profile of the cam link 190. Cam link 190 is pivotally connected by a rivet or pin 210 to a housing link 200.
With further reference to FIGS. 2A and 2B, the toggle mechanism of the circuit breaker 10 also includes a link housing 200, which is further connected a projecting arm 205. The link housing is pivotally connected to the cam link 190 by a pin or rivet 210 and pivotally connected to the contact bar 70 by a rivet 220.
The toggle mechanism further includes a sear assembly, including a sear pin 230 which extends through an aperture in the link housing 200 generally corresponding to a location of an outer edge 195 of the cam link 190. This sear pin 230 includes a circularly curved surface 232 (see FIG. 2B) which is intersected by a substantially planar surface 233. The sear assembly also includes a leg 235 (see FIG. 2A), connected to the sear pin 230, and a sear striker bar 240, which is connected to the leg 235 and projects into the plane of the paper, as viewed in FIG. 2A. A helical spring 250, which encircles the sear pin 230, pivotally biases the leg 235 of the sear assembly clockwise, into contact with the leg 205 of the link housing 200, and biasing the planar surface 233 of the sear pin 230 into substantial contact with the bottom surface 198 of the step in the cam link 190. A force exerted against the sear striker bar 240 is transmitted to the leg 235, and acts as a torque on the sear pin 230 to angularly displace the substantially planar surface 233 of the sear pin 230 from coplanarity the surface 198 of the cam link 190, thus raising the leading edge 234 of the substantially planar surface 233 of the sear pin 230 above the top edge of the surface 194. This rotation results in elimination of a holding force for the contact bar 70 in the contacting position, generated by the helical spring 85 acting on the contact arm 70, through the rivet 220 and link housing 200 and sear pin 230 leading edge 234, against the surface 194 of the cam link 190, acting on the pin 180, ears 162 of handle 160, held in place by pin 170 with respect to the casing 20 and frame 100.
The initial clockwise rotation of the cam link 190 is limited by a hook 199 in the outer profile of the cam link 190, at a distance from the step, which partially encircles, and is capable of frictionally engaging, the sear pin 230. In addition, the distance from the step to the hook 199 is slightly larger than the cross-sectional dimension, e.g., the diameter, of the sear pin 230. This dimensional difference determines the amount of clockwise rotation the cam link 190 undergoes before this rotation is stopped by frictional engagement between the hook 199 and the sear pin 230.
As a consequence, the sear pin 230 engages the step in the cam link 190, i.e., a portion of the surface 194 of the cam link 190 overlaps and contacts a leading portion of the curved surface 232 of the sear pin 230. Thus, it is by virtue of this engagement that the toggle mechanism is locked and thus capable of opposing and counteracting the pivotal biasing force exerted by the spring 85 on the contact bar 70, thereby maintaining the electrical connection between the contacts 50 and 60.
By manually pivoting the handle 160 in the counterclockwise direction (as viewed in FIG. 1), the toggle mechanism, while remaining locked, is translated and rotated out of alignment with the pivotal biasing force exerted by the spring 85 on the contact bar 70. This biasing force then pivots the contact bar 70 in the counterclockwise direction, toward the frame 100, resulting in the electrical connection between the contacts 50 and 60 being broken, thus assuming a noncontacting position. When in the full counterclockwise position, the handle 160 applies a slight tension or no force on the cam link 190, resulting in a full extension of the cam link 190 with respect to the link housing 200. In this position, the leading edge of the surface 232 of the sear pin 230 engages the surface 194, and thus the toggle mechanism is in its locked position. Therefore, manually pivoting the handle 160 from the left to right, i.e., in the clockwise direction, then serves to reverse the process to close the contacts 50, 60, since a force against the action of spring 85 is transmitted by clockwise rotation of the handle to the contact bar 70.
As shown in FIG. 1, the armature 260, pivotally connected to the frame 100, includes a leg 265 which is positioned adjacent the sear striker bar 240. In the event of an overcurrent in the circuit to be protected, this overcurrent will necessarily also flow through the coil 110, producing a magnetic force which induces the armature 260 to pivot toward the pole piece 130. As a consequence, the armature leg 265 will strike the sear striker bar 240, pivoting the sear pin 230 out of engagement with the step (intersection of surfaces 194, 198) in the cam link 190, thereby allowing the force of spring 85 to collapse the toggle mechanism. In the absence of the opposing force exerted by the toggle mechanism, the biasing force exerted by the spring 85 on the contact bar 70 will pivot the contact bar 70 in the counterclockwise direction, toward the frame 100, resulting in the electrical connection between the contacts 50 and 60 being broken.
As a safety precaution, the operating mechanism is configured to retain a manually engageable operating handle 160 in its ON or an intermediate, tripped position, if the electrical contacts 50, 60 are welded together. Thus, the handle 160 will not assume the OFF position if the contacts are held together. In addition, if the manually engageable operating handle 160 is physically restricted or obstructed in its ON position, the operating mechanism is configured to enable the electrical contacts 50, 60 to separate upon a trip, e.g., due to an overload condition or upon a short circuit or fault current condition. See, U.S. Pat. No. 4,528,531, expressly incorporated herein by reference.
Two or more single pole circuit breakers 10 are readily interconnected to form a multipole circuit breaker. In this configuration, each such single pole circuit breaker 10 further includes, as depicted in FIG. 1, a trip lever 270 (shown in dotted line) which is pivotally connected to the frame 100 by pin 261, which also is the pin about which the armature 260 pivots. The trip lever 270 is generally U-shaped and includes arms 280 (shown in FIG. 1) and 290 (not shown in FIG. 1) which at least partially enfold the frame 100. A helical spring 330, positioned between the frame 100 and the arm 280 and encircling the pin 162, pivotally biases the trip lever toward the frame 100. A projection 300 of the trip lever 270, which, as viewed in FIG. 1, projects out of the plane of the paper, is intended for insertion into a corresponding aperture 301 in the trip lever of an adjacent single pole circuit breaker. Thus, any pivotal motion imparted to the trip lever 270, in opposition to the biasing force exerted by the spring 330, is transmitted to the adjacent trip lever, and vice versa. The projection 300 and aperture of a trip lever of an adjacent breaker, are preferably tapered, to ensure a secure fit therebetween. When the toggle link collapses, a protrusion 291 (not shown in FIG. 1) from the contact bar 70 displaces a cam surface 292 of the arm 290, thus rotating the trip lever about pin 261, and displacing the projection 300. The projection 300 thus moves in an arc about the pin 261, and thus an arcuate slot is provided in a housing half of housing 20 to transmit forces through the projection 300. A portion of arm 280 acts directly on the sear striker bar 240, to trip the associated toggle mechanism of an adjacent switch pole. A protrusion from the frame, for example a stop, limits the motion of arm 290 of the trip lever 270, in response to a bias spring about the pivot axis. Thus, Since the trip lever 270 is not operated directly by the armature 260, the trip dynamics of the circuit breaker are unaffected. The drag on the trip mechanism from the trip lever 270 is insignificant.
Side 280 has a cam surface 285, having a bend of about 45 degrees, which engages the sear striker bar 240 at about the position of the bend. Side 290 has a bend 293, forming cam surface 292, which is perpendicular with the portion of the side 290. Protrusion 291 extends from the side of the moveable contact bar 70, which contacts the surface 292 midway through the travel of the contact bar 70. When the contact bar 70 is displaced, the protrusion 291 pushes against the surface 292, causing a rotation about the pin 261, causing the surface 285 of side 280 to displace the sear striker bar 240. It is clear that in operation, rotation of trip lever 270 about pin 261 will result in tripping of the toggle mechanism, and tripping of the toggle mechanism will result in rotation of the trip lever about the pin 261. See, e.g., U.S. Pat. Nos. 5,557,082, 5,214,402, 5,162,765, 5,117,208, 5,066,935, and 4,912,441, and also U.S. Pat. Nos. 4,492,941, 4,437,488, 4,276,526, and 3,786,380, expressly incorporated herein by reference.
In addition to the above-described "master" pole, adjacent thereto is provided a "slave" pole. This "slave" pole is identical to the "master" pole with the exception that it lacks the coil 110, magnetic core 120, pole piece 130, and armature 260. The projection 300 passes through aligned arcuate slots in the respective case walls between the adjacent "master" and "slave" switch pole housings 20. The trip lever 271 in the "slave" pole, like the trip lever 270 of the "master" pole, receives a torque with respect to its frame from the tapered projection 300, extending laterally from the "master" pole housing 20 into the "slave" pole housing 20, into a tapered recess of the trip lever 271 of the "slave" pole. As the trip lever 271 in the "slave" pole rotates, it applies a force to the "slave" pole sear striker bar 240, which in turn rotates the "slave" pole sear pin 230 about its axis, resulting in collapse of the "slave" pole toggle mechanism 102. Thus, when the "master" mechanism 101 trips or is manually switched OFF, the "slave" mechanism 102 trips slightly thereafter. A dual ended rod 302 connects the handle 160 of the master and slave circuit breakers so that they move in unison.
As shown in FIG. 3, an electrical braided wire 141 serves to connect the terminal 30 in the "master" pole and an electrical braid 142 serves to electrically connect the terminal 31 in the "slave" pole to one end of the coil 110. Electrical braids 150, 152 connect the opposite end of the coil 110 to the contact bars 70, 71 of the "master" and "slave" poles, respectively. Electrical braid 151 passes through a rectangular portal formed in both adjacent case halves. The end of the coil 110 extends through the portal, so that electrical braid 142 does not have to pass through the portal, and indeed, to facilitate connection, the braid 141 may partially or completely pass through the portal to join the end of coil 110. Conductive plates 43, 42 are provided for bridging the lug connections 30, 31 and 40, 41, respectively, to ensure low impedance between the "master" and "slave" mechanisms.
To extinguish arcing caused by opening of the contacts 50 and 60, a stacked array of metal plates 73 (shown in FIG. 3) are supported within and by the two half cases 14 and 16 of the circuit breaker housing 20 around the moveable contact arm 70.
Each housing casing half 14, 16 includes the following features: An upper boss (half) for the toggle handle 21; a lower access port 22; a set of four rivet holes for assembly 23; a pair of half-recesses for a mounting nut 24; a first pivot recess for the handle pin 25; a second pivot recess for the contact arm pin 26; a pair of half-recesses for electrical contact lugs 27; a set of indentations for supporting the arc chute members 28; and a number of side port halves 29. In addition, each respective inner case half 16, 14' of the "master" and "slave" housing, respectively, has a number of apertures. First, a generally rectangular portal 31 is provided for paralleling the electrical connections from the pair of lug contacts 30, 31 and the movable contact bars 70, 71. Second, an arcuate aperture 32 is provided for the projection 300 of the trip lever 270. Optionally, an arcuate slot 33 is provided for an internal pin connecting the manual operation handles, causing them to operate synchronously. A cover 34 is provided to close each of the lower access ports. Each of the "master" and "slave" housings 20 are about 2.5 inches long, 0.75 inches wide, and 2 inches deep, with electrical contact bolts on 2 inch centers, each being individually rated at about 100 Amps. The resulting parallel multipole design with a rating of 150 Amps therefore fits within a form factor of 2.5 by 1.5 by 2 inches,
The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are, therefore, intended to be embraced therein.
The term "comprising", as used herein, shall be interpreted as including, but not limited to inclusion of other elements not inconsistent with the structures and/or functions of the other elements recited.
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A parallel pole magnetohydraulic circuit breaker, having a single trip element and a pair of trip mechanisms, achieving an increased current carrying capacity with reduced nuisance trips. The trip mechanisms are contained within separate housings, with electrical connections and multipole trip mechanism communicating through apertures in the common wall. Preferably, the armature of the trip element acts on a single trip mechanism, which multiplies the available force to trigger a trip of the other trip mechanism.
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BACKGROUND OF THE INVENTION
[0001] Today's broadband networks are constructed of an interconnection of different transport technologies used for different parts of the network such as access, aggregation, transport, and feeding.
[0002] The following is a list of acronyms used in the body of the specification and their definitions, which shall apply throughout the specification unless otherwise noted.
[0003] Acronyms:
[0004] ADSL Asymmetric Digital Subscriber Line
[0005] ATM Asynchronous Transfer Mode
[0006] B2B Business to Business
[0007] E2E End to End
[0008] DSL Digital Subscriber Line
[0009] FTTx Fiber To The x=Home, Node, Cabinet, Building, Curb
[0010] GbE Gigabit Ethernet
[0011] GPON Gigabit-capable Passive Optical Networks
[0012] GSM Global System for Mobile Communications
[0013] HDTV High Definition Television
[0014] IP Internet Protocol
[0015] IPTV Internet Protocol Television
[0016] IPDSLAM Internet Protocol Digital Subscriber Line Access Multiplexer
[0017] LQ&M Loop Qualification and Monitoring
[0018] MPLS Multi-Protocol Label Switching
[0019] OAM Operation Administration and Maintenance
[0020] OPEX Operational Expenditure
[0021] PoP Point of Presence
[0022] PVC Permanent Virtual Circuit
[0023] QoE Quality of Experience
[0024] QoS Quality of Service
[0025] RM Resource Manager
[0026] RPC Remote Procedure Call
[0027] SLA Service Level Agreement
[0028] SOAP Simple Object Access Protocol
[0029] SNMP Simple Network Management Protocol
[0030] VDSL Very High Speed Digital Subscriber Line
[0031] VLAN Virtual Local Area Network
[0032] VoIP Voice over IP
[0033] WCDMA Wide-band Code Division Multiple Access
[0034] xDSL DSL variants (ADSL, SDSL, etc.)
[0035] FIG. 1 depicts a high-level block diagram of a broadband network that is constructed of an interconnection of different transport technologies used for different parts of the network. Network connectivity is supported also by a huge number of different connectivity technologies and network protocols. In order for services to be delivered from an operator point of presence (PoP) to the customer premises with a required quality of service, several technologies, and protocols have to work together end-to-end.
[0036] In such a scenario, a unified operation, administration and management (OAM) system covering the whole workflow from service subscription and service provisioning to service quality maintenance has to interface with all network-parts, which is mostly non-standardized and therefore hard to implement. For the wire-line sector such a system is not standardized and it is up to the wire-line operators to fix their own OAM system solution.
[0037] Existing wire-line broadband solutions have limitations in supporting features like QoS, mobility and security because there is no unified standardized architecture such as in the mobile sector with GSM or WCDMA (ETSI, 3GPP). Interface descriptions between different technologies are proprietary and non-standardized. This leads to a very scattered workflow when providing services to users and thus to a rather fixed service provisioning models, which leads to broadband network shortcomings, including:
[0038] No flexible end to end (e2e) service provisioning
[0039] Low grade of business to business (b2b) interface implementation
[0040] Low e2e QoS management and SLA assurance
[0041] Missing interfaces, protocols for automation
[0042] Low grade of automation during service provisioning, high OPEX
[0043] Problematic service offer extension
[0044] No control and/or feedback from the end user about the QoE (perceived QoS by the end user)
[0045] It would be advantageous to have a system and method for managing access networks connecting to broadband networks that overcomes the disadvantages of the prior art. The present invention provides such a system and method.
BRIEF SUMMARY OF THE INVENTION
[0046] A monitoring function monitors the line conditions of an access network that is connected with a multi-access broadband network. The monitoring function sends data to a Resource Manager (RM) of the access network upon request or following a predetermined timetable. The monitoring function collects, stores, and analyzes performance data, line conditions and stability data using interpretation filters to derive performance indicators. The conditions of the network are also automatically provided to the resource manager for immediate attention if the access network conditions exceed predetermined thresholds.
[0047] Quality of Service (QoS) and nomadism are monitored end-to-end by a distributed Resource Management function, a Loop Qualification and Monitoring (LQ&M) function/tool (hereinafter, “tool”). Local resource managers responsible for bounded parts of a network are in place and cooperating in order to establish and implement global (network wide) QoS policies and guarantees. An access network Resource Manager is disclosed, that interfaces an access network specific Loop Qualification and Monitoring tool to get support on access network resource-related questions including line performance and stability in the access network.
[0048] The invention allows for real-time interaction between access nodes and core network management functions to maintain and guarantee QoS and Quality of Experience (QoE) for services. This interaction is enabled through web service-based interfaces.
[0049] In order to guarantee QoS for a given service-mix, it is necessary to include access network resource status information into resource management decisions during service subscription and service invocation. During service operation, status information (service quality monitoring) is used to check a Service Level Agreement (SLA), which is a means of service assurance.
[0050] The LQ&M tool pushes information to an associated RM in case the line quality has changed (line faults, change of noise-environment) so the RM can react (failure diagnoses, failure repair, automatic service reconfiguration).
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0051] In the following section, the invention will be described with reference to exemplary embodiments illustrated in the figures, in which:
[0052] FIG. 1 depicts a high-level block diagram of a broadband network that is constructed of an interconnection of different transport technologies used for different parts of the network;
[0053] FIG. 2 depicts a block diagram of a Multi-Service, Multi-Access Network Structure for future broadband networks;
[0054] FIG. 3 illustrates an access network reference architecture through which multi-access accounts can be used to deliver services according to an embodiment of the present invention;
[0055] FIG. 4 depicts a Resource Manager and a Loop Qualification and Monitoring tool in accordance with an embodiment of the present invention;
[0056] FIG. 5 is an exemplary high-level block diagram that illustrates a communication interface between the access network and the Resource Manager in accordance with an embodiment of the present invention;
[0057] FIG. 6 depicts a high level block diagram of the resource manager, interface and LQ&M in accordance with an embodiment of the present invention;
[0058] FIG. 7 depicts a high-level diagram of message flow for Use Case 1 in accordance with an embodiment of the present invention;
[0059] FIG. 8 illustrates a message flow for Use Case 2 in accordance with an embodiment of the present invention; and
[0060] FIG. 9 depicts the notification function message flow in the LQ&M tool for Use Case 3 in accordance with an embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0061] In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be understood by those skilled in the art that the present invention may be practiced without these specific details. In other instances, well-known methods, procedures, components and circuits have not been described in detail so as not to obscure the present invention.
[0062] A Digital Subscriber Line (DSL) access network is described in the specification and figures to avoid the possibility of confusion. However, those skilled in the art will recognize that various access network types and interface configurations may be used in place of the example DSL access network to accomplish the same outcome.
[0063] FIG. 2 depicts a possible Multi-Service, Multi-Access Network Structure 200 for future broadband networks. Future broadband wire-line networks consist of different network parts that will need to work together in order to provide multi-service and multi-access data transport. Multi-service means that different services, such as data services (Internet access, file-sharing), speech services (VoIP, voice messaging, gambling) and video-based services (IPTV, HDTV, video conferencing, gaming applications) are offered to users by different service providers.
[0064] FIG. 3 illustrates an access network reference architecture 300 through which multi-access accounts can be used to deliver services according to an embodiment of the present invention. Typical access media that are installed and used to connect to the customer premise sides are:
Digital Subscriber Loop (DSL) 302 , i.e. digital data transmission over the telephone loop via ADSL1/2/2+ or VDSL1/2; fiber to the node, cabinet, curb, building (FTTx) architectures 304 , building point-to-point or multipoint access structures using fiber connections to the proximity of the customers (BPON, GPON), bridging only the very last mile with existing telephone copper lines (VDSL2); deep fiber to the home (FTTH) architectures 306 where fiber is used from the network providers facilities (central office) all the way to residential or enterprise networks (Gb Ethernet) and wireless connections, such as wireless local area network (WLAN) or mini-link transporting data via radio connections.
[0069] Networks are very general in terms of service-mixes, but several other important features can be supported by the structure, for instance:
Service Flow Separation—Ethernet or IP flows are used rather than fixed connections providing a maximum amount of flexibility in service and delivery constellations; Quality of Service (QoS)—End-to-end resource negotiation, reservation and authorization means can be implemented via B2B interfaces between service and access provider and different access media allows for different grades of service, and Nomadism and Mobility: where nomadism is the ability of the user to change his network access point after moving; the flow: principle gives the possibility to access subscribed services anywhere in the access network by user authentication.
[0073] FIG. 4 depicts a Resource Manager and a Loop Qualification and Monitoring tool in accordance with an embodiment of the present invention. Although DSL is a robust and cheap technology that has become the most popular first mile technology, it is known that the actual transport performance (rate, delay, frame loss rate) heavily depends on the copper quality (line length, diameter, age) and copper environment (binder sizes, connector quality, electromagnetic noise environment) and therefore varies between lines. DSL currently provides sufficient capacity for data and voice services, new services like video and gaming, etc. may require the system to operate at the limit of feasibility.
[0074] A Resource Manager (RM) 402 is connected to a DSL-specific Loop Qualification and Monitoring tool (LQ&M) 404 specially designed to classify individual DSL lines. The interface between RM 402 and LQ&M 404 supports the main RM with decisions on service subscription, resource allocation, service invocation, QoS monitoring and DSL fault localization and notification.
[0075] LQ&M 404 , which is responsible for a plurality of users, monitors each user's DSL link (in the DSL case) in terms of service quality, and reports that data to RM 402 in the Resource Management system situated at access edge site 406 . The data is then incorporated into service decisions.
[0076] In a communication, the LQ&M 404 side runs web-services to which the client can connect at the RM side. This structure is used by RM 402 to request status data from the access network. In case LQ&M 404 needs to pro-actively notify RM 402 about a changing status in the access network, a server in the RM 402 is ready to receive connections from the LQ&M 404 client.
[0077] FIG. 5 is an exemplary high-level block diagram that illustrates a communication interface between the access network and the Resource Manager in accordance with an embodiment of the present invention. In the present invention, Resource Manager 502 and LQ&M 504 act as either a server or a client, each function acting as a server, providing web services to the other. In order to communicate DSL line status (i.e., line ‘health’) towards Resource Manager 502 , a SOAP protocol (in this example) is used for implementing web services. Communication in both directions is required. Resource Manager 502 can always poll the LQ&M 504 for line related status information (e.g., for QoS monitoring or during service provisioning). In this case, LQ&M 504 hosts the server offering web-service to the Resource Manager, which acts as a client; and LQ&M 504 may push urgent information (for example, line drops) to Resource Manager 502 to indicate a change in the access network. Resource Manager 502 acts as a server offering web services to LQ&M 504 , which is acting as a client.
[0078] FIG. 6 depicts a high-level block diagram of the Resource Manager, interface and LQ&M in accordance with an embodiment of the present invention. LQ&M server 604 sends queries via SNMP interface 609 to the actual Access Nodes in the DSL network (not shown) to learn about the current line state (scheduled monitoring). Performance and stability data is fetched from the access node in a scheduled way and stored for statistical analysis in database 610 . Several key performance indicators such as mean line rate, delay and stability-measures, are derived from the fetched source data utilizing an interpretation filter. The LQ&M server interfaces with the DSL Network Management System (NMS) in order to fetch port addressing information along with line and end-user configurations and information.
[0079] RM 602 requests data from LQ&M tool server 604 to learn about the access network state in case of admission control, policy or resource reservation decisions that have to be made.
[0080] During service delivery, LQ&M tool server 604 automatically sends notifications to RM 602 about DSL status changes for fault notification, fault diagnoses and fault repair purposes. If LQ&M tool server 604 identifies performance degradations on the DSL, RM 602 is informed so that re-prioritization and re-allocation of resources may be started. The interface 608 between RM 602 and LQ&M tool server 604 can be implemented by any generic Remote Procedure Call (RPC) interface including a SOAP interface.
[0081] Each entity (RM and LQ&M server) utilizes associated RPCs to handle the different message types listed in Table 1 below. LQ&M tool server 604 contains definitions that allow RM 602 to send request messages, whereas RM 602 holds the means to handle notification messages initiated by LQ&M tool server 604 .
[0082] Table 1 shows an overview of the types of messages utilized. For “last mile” monitoring and LQ&M tool configuration request/response messages are defined. For last mile status changes, notifications are generated.
[0000]
TABLE 1
Message Overview
Response
Flow
Request
Access Node Status Request
Access Node Status Response
RM LQ&M RM
DSL Resource Status Request
DSL Resource Status Response
RM LQ&M RM
ATM Resource Status Request
ATM Resource Status Reply
RM LQ&M RM
Threshold Update Request
Threshold Update Response
RM LQ&M RM
Threshold Retrieve Request
Threshold Retrieve Response
RM LQ&M RM
Notification
LQ&M Alive
—
LQ&M RM
DSL Access Node Notification
—
LQ&M RM
DSL Line Notification
—
LQ&M RM
DSL Threshold Notification
—
LQ&M RM
[0083] The following use cases outline the possible interaction between different entities during resource negotiation and service delivery, illustrating how the messages listed in Table 1 are used.
[0084] The first two use cases describe situations where the RM actively requests information about DSL line resources from LQ&M in order to maintain admission control for service subscription and service invocation (request/response type of messages). The third use case shows a situation where LQ&M pushes information about changes in the actual DSL performance of a user towards the resource manager to adapt the admission control scheme (notification type of messages).
[0085] FIG. 7 depicts a high-level diagram of message flow for Use Case 1 in accordance with an embodiment of the present invention. The first use case describes the circumstances when a user creates a new service subscription through a self-provisioning portal. The user browses to a self-provisioning portal to subscribe for a new service (IPTV). The portal displays the different available services together with their accompanying SLA descriptions. When the user initiates the service subscription procedure, a service request 702 is sent to the service manager at the service provider side to notify of the user subscription request. This initiates a procedure to check if enough resources are available to deliver the service according to the SLA (Resource Validation Request). This request towards RM is translated into a DSL Resource Status Request 704 towards LQ&M that fetches the DSL status information via the SNMP interface. LQ&M will parse this information into a DSL Resource Status Response 706 .
[0086] The DSL Resource Status Response message contains information of the total resource available on the DSL line. RM will use this information to update the network data model and cross-reference with existing service on the line to verify if the necessary resource are available to fulfill the SLA. The result of which will be return in the Service Subscription Reply to the end user.
[0087] FIG. 8 illustrates a message flow for Use Case 2 in accordance with an embodiment of the present invention. Use case 2 assumes that a service subscription already exists and that a user (residential, business user, network operator, service provider) wishes to invoice the service through the self-provisioning portal (note that the service invocation is not required to be initiated through the portal).
[0088] Service invocation 802 is issued to the service manager when the user selects the service to invoke from the portal. This will trigger Resource Validation Request 804 to RM, which in turn probes LQ&M with ATM Resource Status Request 806 . LQ&M will then read the ATM status information from the Internet Protocol Digital Subscriber Line Access Multiplexer (IPDSLAM) through the SNMP interface and send ATM Resource Status Response 808 to RM.
[0089] RM shall use the information in the response message in combination with the network data model and policy engine to determine availability of the requested resources. The result is sent to SM in the Resource Validation Reply, which then triggers an update of the self-provisioning portal.
[0090] During the invocation procedure the network resources are reserved; depending on the service type (unicast, multicast) and the user type (fixed, authenticated).
[0091] FIG. 9 depicts a high-level message flow diagram for Use Case 3 in accordance with an embodiment of the present invention. LQ&M uses pre-configured threshold values to detect performance changes. If the LQ&M function detects a change in line performance due to altered conditions on the line (noise, failures) the function will report (push) a status change (performance change) to the RM. With this information, RM can adapt its admission control scheme used for service invocation, update its network data model, and also notify the service manager about the change. A DSL Line Notification is followed by a DSL Resource Status Request message to retrieve the new line values. This may not have any effect on the current services running, but will influence the availability of new service session invocations. The DSL Line Notification 902 message is used to inform the RM on status change of an access node (access node up/down). The DSL Line Notification message provides line-specific changes (an access node supports several lines) such as a line activating or going down.
[0092] A DSL Threshold Notification message (not shown) is sent by the access node if a predetermined threshold on a performance parameter is crossed, this message is used to check whether conditions on a line have changed. The RM uses this information to recover the QoS and QoE to fulfill the applicable Service Level Agreement (SLA).
[0093] A simple example is that the RM (OAM function) is made aware that something is wrong with a line and services are dropped. This function can be used for fast and automatic trouble shooting and fault localization.
[0094] Available line resources are important to relay to the resource manager during the resource negotiation process of setting up a service. The resource manager may query LQ&M to request the current line status of a particular PVC, port, and DSL access node. This information will be utilized by RM to apply necessary call admission control policies
[0095] Line values may change due to the nature of DSL, based on outside interference, cross-talk, etc. This may lead to service degradation if certain line values are reached. LQ&M shall send a notification to RM when a specified attribute threshold is broken. The message can include the following information: access node id, port, PVC, VLAN, time, attribute and the new attribute value.
[0096] RM will apply appropriate policies on additional service that will be requested/activated based on the new line values. A notification from the LQ&M will trigger an update in the network data model used by RM.
[0097] Once the Resource Manager has committed resources for a specific service flow a notification is sent to the LQ&M function. The notification contains information on how to identify the service (access node identity and port) and parameter thresholds that will need to be monitored (i.e. SNR margins, CRC errors, bit rate, etc). This data will also define when to send line change notifications.
[0098] Current DSL line values may only be useful for short-term resource commitments. However, when creating a subscription or long-term resource reservations, such as for IPTV and VoIP usage, it may be important to take a historical view of DSL line stability. A line that experiences greater interference may not be suitable to deliver certain services, especially if the service provider wishes to provide service delivery guarantees. RM may contact LQ&M to get historical statistical values on specific user line read from the access node. Since LQ&M tracks performance/stability data from the access nodes and stores it in a database, it is possible to compute statistical performance indicators such as average rate and stability parameters.
[0099] A unified OAM and Resource Manager as described above provides a step towards a true e2e management system. Advantages include:
Service Assurance: SLA guarantees and QoS is possible by that solution because the LQ&M tools can monitor the actual service quality and compare with the agreed service layer agreement (SLA); Dynamic Network View: The LQ&M tool always has a fresh view of the network in terms of topology, line-state and performance. The RM can always learn about the network structure it needs to make a decision; Monitoring, Notifications, Pro-active Alarms: LQ&M enables automated and effective fault localization, fault diagnoses and fault repair mechanisms for DSL. This reduces OPEX costs due to line problems; Nomadism on DSL: Since RM can query the LQ&M tools anytime on the resource statues for lines, the proposed solution also enables Nomadism. The RM knows if services that a user subscribed to on his home-line are also working on visited-lines; and Enables Self-Provisioning: Since the RM knows about the capacity and stability of lines, self-provisioning of services becomes possible (RM can decide if a service should be offered to a customer).
[0105] As will be recognized by those skilled in the art, the innovative concepts described in the present application can be modified and varied over a wide range of applications. Accordingly, the scope of patented subject matter should not be limited to any of the specific exemplary teachings discussed above, but is instead defined by the following claims.
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A qualification and monitoring function ( 604, 606 ) monitors the line conditions of a last mile access network that is connected with a multi-access broadband network. The qualification and monitoring function ( 604, 606 ) sends data to a Resource Manager ( 602 ) of the access network upon request. The monitoring function collects, stores, and analyzes performance data, media conditions and stability data using interpretation filters to derive performance indicators. The conditions of the network are also automatically provided to the resource manager ( 602 ) for immediate attention if the access network conditions exceed predetermined thresholds.
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FIELD
[0001] The present invention relates generally to the field of heating, ventilation and air conditioning. The present invention more specifically relates to a heating, ventilation and air conditioning (HVAC) system which can be conveniently and readily installed in a number of locations, environments and configurations.
BACKGROUND
[0002] HVAC systems are used to provide heating, ventilation and/or air conditioning to an environment or space provided within building interiors. One type of HVAC system is an under-floor HVAC system. An under-floor HVAC system is used as an alternative to an overhead or in-wall system, providing for the passage of conditioned air beneath a floor (typically a raised, accessible floor system).
[0003] Current under-floor HVAC systems have several drawbacks as they often require: costly fans, coil and filter units; two separate systems for heating and cooling; a relatively large number of manual or automated individual floor diffusers that can be particularly cumbersome or ineffective for perimeter exposures; and/or partitioned under-floor plenums.
[0004] Accordingly, it would be advantageous to provide an HVAC system which can be conveniently and readily installed in a number of locations, environments and configurations including in particular under-floor applications. It would further be advantageous to provide an HVAC system that can provide for modularity in the construction and assembly of the system. It would further be advantageous to provide an HVAC system that can provide effective supply air plume characteristics under a variety of thermal load conditions. It would further be advantageous to provide an HVAC system that can activate air flow to different segments of the system in response to different thermal or ventilation needs. It would further be advantageous to provide an HVAC system that can be easily installed after the installation of a raised floor system and provides flexibility for relocation or reconfiguration. It would further be advantageous to provide an HVAC system that can reduce the number of components and floor plenum space involved and can provide convenient access for maintenance of its components. It would further be advantageous to provide an HVAC system that can employ a combination of floor-mounted, sill-mounted or other architecturally compatible air diffuser arrangements. It would further be advantageous to provide an HVAC system that can activate air flow to different segments of the system in response to different thermal or ventilation needs. It would be desirable to provide a system and method that provides any one or more of these or other advantageous features in a variety of configurations.
SUMMARY
[0005] One embodiment of the invention relates to a system and method that can modulate multiple supply air jets using an actuator and sliding aperture plates arranged in a horizontal plane. A single control actuator (such as a linear or linked rotary actuator) can modulate simultaneously the flow from a number of supply air jets provided by an under-floor air distribution system. The actuator can slide one movable aperture plate in a horizontal plane proximate a second fixed aperture plate to vary the net resultant aperture area exposed to a pressurized under-floor plenum. This configuration can maintain approximately constant air jet velocity and an elevated level of room air mixing through a large range of supply air flow.
[0006] Another embodiment of the invention relates to a system and method to modify the flow characteristics of a linear bar type supply air grille to enhance its performance when applied to an air distribution system such as perimeter building zones of an under-floor air distribution system or other suited applications. By arranging narrow air jet openings beneath and perpendicular to the bars of a continuous linear air supply floor grille, large amounts of room air can be induced by the jets, both perpendicularly between adjacent jets, and laterally into the small low-pressure zones created within each air jet above each of several grille bars spanning the jet opening. This room air induction can aid in achieving desired supply characteristics in supply air plumes.
[0007] A further embodiment of the invention relates to a system and method to passively induce room air with under-floor air jets to increase the heating output of an adjacent heating module (such as under-floor finned tubes located in isolated under-floor pockets). A passive induction effect can increase the heating output of the heating module while supply air to the room is warmed, without air passage connection between the under-floor air plenum and the pockets. In this application, vertical air supply jets flank the ends (and/or sides) of the heating module. The flanking air jets induce and help disperse into the room the convective heating plume from the heating module.
[0008] A further embodiment of the invention relates to a system and method of providing multi-variable control of multi-part air flows using aperture plates. Segmentally nuanced aperture plates (e.g., having apertures with differently shaped or spaced characteristics in different segments of the plates), in conjunction with controlling the relative lateral position of the plates can be used to control the flows of multiple sources of air through multi-step sequences or proportions. Apertures in one segment of the plates exposed to or provided near a heating source can open first in a heating mode, engaging apertures designed to accommodate minimum ventilation air, and then engage additional apertures designed to accommodate maximum cooling, all as the relative lateral movement of the plates is extended.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] [0009]FIG. 1 is a top plan view of a heating, ventilation and air conditioning (HVAC) system according to an exemplary embodiment.
[0010] [0010]FIG. 2 is a top plan view of the HVAC system shown in FIG. 1, with a floor grille of the system removed.
[0011] [0011]FIG. 3 is a side elevation view of the HVAC system shown in FIG. 1.
[0012] [0012]FIG. 4 is a cross section view of the HVAC system shown in FIG. 2, taken along the line 4 - 4 .
[0013] [0013]FIG. 5 is a detail view of section A shown in FIG. 3.
[0014] [0014]FIG. 6 is a top plan view of the HVAC system according to a second exemplary embodiment with a floor grille of the system removed.
[0015] [0015]FIG. 7 is a side elevation view of the HVAC system shown in FIG. 6.
[0016] [0016]FIG. 8 is a series of top plan views of the aperture plates of FIG. 2 shown in various positions.
DETAILED DESCRIPTION
[0017] A heating, ventilation and air conditioning (HVAC) system which can be conveniently and readily installed in a number of locations, environments and configurations is disclosed. Generally, the system includes intermittent sections of variable-area, sliding-damper air supply outlets, optionally interspersed with and augmenting heating output of one or more heating sources. According to a preferred embodiment, an HVAC system is used to provide distribution for an under-floor air supply along perimeter zones in a space (such as a room) using one or more linear floor grilles.
[0018] The systems and methods disclosed provide an economical and functionally integrated means of serving the heating, ventilating and air conditioning requirements in zones by providing one or more cooling and ventilation modules (such as an under-floor air supply system using several supply air jets) in conjunction with one or more heating modules (such as under-floor pockets of finned heating tube or fan-powered plenum sections). Control of the system is generally effected by aligning and positioning two aperture plates provided with the cooling and ventilation module using a control actuator.
[0019] Referring to FIGS. 1-8, heating, ventilation and air conditioning (HVAC) systems and components thereof are shown according to exemplary embodiments. Shown in FIG. 1 is a system 10 that can be used to provide heating, ventilation and/or air conditioning to an environment or space (referred to generally as space 26 ). System 10 is shown installed in and used in conjunction with a raised floor system 12 in an interior environment. It should be noted at the outset that the systems and methods described can be installed and used in a variety of applications and environments including other interior applications not using a raised floor system, within walls and/or ceilings, exterior applications (i.e., providing air flow to outside spaces), provided along a perimeter of a space, provided centrally within a space, or any other desired configuration or arrangement.
[0020] System 10 is shown as installed and used in conjunction with a raised floor system 12 . Floor system 12 can be any of a variety of conventional arrangements utilized within an environment or space 26 that provides a raised floor or support surface. As shown in FIG. 4, floor system 12 typically comprises a number of floor panels 14 (and/or other flooring surfaces, finished floor, carpeting, etc.) raised off of a sub-floor 18 and supported by a number of columns or posts 20 . System 10 is supported by frame members 42 provided along opposing edges of an opening in floor panels 14 . Frame members 42 have a horizontal portion 50 and a vertical portion 52 . Frame member 42 is supported by floor panels 14 along horizontal portion 50 . Vertical portion 52 is sized to receive a grille 22 and to keep grille 22 substantially flush with the top of finished floor panels 14 (which may or may not be finished, carpeted, etc.). According to a preferred embodiment, system 10 has a width approximately equal to the width of floor panel 14 , allowing system 10 to be installed in floor system 12 in a modular fashion and minimizing the amount of alterations or adjustments needed to adjacent floor panels. According to alternative embodiments, the floor panel spacing can be adjusted to accept an HVAC assembly between integer rows of tiles or between tiles and an exterior wall, or the system can have any width or size desired (including fractional sizes of floor panels).
[0021] Referring to FIGS. 2-4, system 10 generally comprises one or more cooling and ventilation modules 40 and one or more heating modules 80 . Cooling and ventilation module 40 controls air supply or air flow from an under-floor plenum or pressurized space 90 to environment 26 and also provides cooling air to environment 26 . Heating module 40 generally provides heated air to environment 26 .
[0022] A ventilation module 40 includes a first plate 44 , a second plate 46 and an actuator 48 . First plate 44 is fixed in position with respect to frame member 42 . First plate 44 is provided with a plurality of apertures or openings 60 . According to a particularly preferred embodiment, apertures 60 are rectangular in shape and are provided transverse or perpendicular to the length of system 10 (i.e., perpendicular to axis X-X shown in FIG. 2).
[0023] Second plate 46 is shown provided below first plate 44 . Second plate 46 is moveable with respect to first plate 44 along axis X-X shown in FIG. 2 (e.g., slidable in a horizontal plane). Second plate 46 is also provided with a plurality of apertures or openings 62 . According to a particularly preferred embodiment, apertures 62 are rectangular in shape and are provided transverse or perpendicular to the length of system 10 (i.e., perpendicular to axis X-X shown in FIG. 2). According to an alternative embodiment, the second plate can be provided above the first plate.
[0024] First plate 44 and second plate 46 are arranged such that second plate 46 can move to a number of positions between (and including) a first position and a second position with respect to first plate 44 . In the first position, apertures 60 and 62 are aligned with respect to each other such that air flow from under-floor plenum 90 into space 26 will be minimally impeded (e.g., a fully open position). In the second position, apertures 60 and 62 are not aligned with respect to each other such that air flow is maximally impeded (e.g., a closed position). The result of changing the position of second plate 46 with respect to first plate 44 is that the alignment of apertures 60 and 62 changes, causing a change in the effective opening size or area through which air can flow (such as air jets). The differing opening sizes result in differing amounts of air flow from under-floor plenum 90 into space 26 .
[0025] By sliding plate 46 with a series of apertures 62 (e.g. transverse slots) beneath a similar fixed plate 42 , a control actuator 48 can modulate simultaneously the open area of a series of supply air jets (and thereby control the temperature). Each aperture pair is exposed to full plenum pressure regardless of active area (e.g., size), maintaining nearly constant velocity through a large range of air supply flow rates.
[0026] According to a preferred embodiment, apertures 60 and 62 can vary in size and spacing. As an example, the apertures provided toward the ends of plate 46 are larger in area than the corresponding apertures provided toward the ends of plate 44 . As another example, the apertures of both plates can be larger in one or more segments. Also, aperture sizes can vary from plate to plate, and from module to module. Providing such variations enables system 10 to be usable in a range of applications. One such application is to inject a minimum supply airflow immediately adjacent heating modules 80 . This configuration passively enhances heat output while tempering supply air, and the partial division of the aggregate supply air plume further reduces its vertical height. This configuration also regulates heating air flow in sequence with cooling air flows and disperses minimum air flow jets uniformly.
[0027] As best shown in FIGS. 5 and 8, segmentally nuanced aperture plates are shown having variations or nuances of apertures (such as different spacings and sizes) including variations between plate 44 and plate 46 as well as segments within the same plate (such as larger apertures near the ends of plate 46 and smaller apertures near the center of plate 46 ). Such variations or nuances in segments or portions of plates 44 and/or 46 allow one area or function to be effected while other areas or functions are inactive. For example, extra heating or cooling can be provided to an area having a higher thermal load, additional air flow can be provided in low circulation areas, heating modules can be induced or activated by the segmentally nuanced aperture places while limiting cooling air flow, etc.
[0028] The shape of the apertures can also be varied to alter characteristics of air flow. For example, the apertures can be modified by variously shaping the apertures, including parabolic or other shapes, to address specific capacity needs, low flow control needs, or increased plate overlap area for tighter shut-off. The aperture opening sizes can be increased to function properly with lower plenum design pressures or decreased for higher plenum design pressures. By creating apertures with differently shaped or spaced characteristics, and by controlling the lateral relative position of the plates, a control apparatus can be capable of sequencing the flows of multiple sources of air through multi-step sequences or proportions. For example, apertures in one segment of the plates exposed near a heating source can open first in a heating mode (as shown in FIG. 5 as opening 190 , and FIG. 8 as shaded areas), engaging apertures designed to accommodate minimum ventilation air, and then engaging additional apertures designed to accommodate maximum cooling in conjunction with additional relative lateral movement of the plates.
[0029] As shown in FIG. 5, apertures 60 provided in first plate 44 may include one or more deflectors 170 . Deflectors 170 may be provided at the same angles along first plate 44 , or alternatively at varying angles along the first plate. For example, deflector 170 a is provided at an angle which causes less deflection or re-orientation of air flow as compared to deflector 170 b . This configuration may be desirable to cause diverging air jets, to enhance induction of room air and to lower the apex of the resultant plume of the supply air and room air mixture, etc.
[0030] Referring back to FIG. 4, one or more bearings 64 may be provided between first plate 44 and second plate 46 to assist in the relative movement between first plate 44 and second plate 46 . According to a particularly preferred embodiment, bearing 64 is a linear bearing. According to alternative embodiments, other assemblies or materials may be provided between the first and second plate to facilitate relative movement. For example, Teflon® slide bearings, nylon slide bearings, ball or roller linear bearings, or friction reducing materials (such as dry lubricants) may be used.
[0031] An air seal 88 (or other gasket or “weather stripping” material) may be provided between first plate 44 and second plate 46 to control or limit leakage and to minimize the direct contact and wear between the parts.
[0032] Referring to FIGS. 2 and 4, actuator 48 is provided to cause relative movement of first plate 44 and second plate 46 relative to each other. Actuator 48 may be any of a variety of mechanisms which provide for such movement. According to a particularly preferred embodiment shown in FIGS. 2 and 5, actuator 48 includes a linkage 51 (such as a tie-rod or arm) coupled to a motor 54 . Activation of motor 54 causes linear movement of linkage 51 (and movement of second plate 46 ). According to an alternative embodiment, the actuator includes a cable coupled to the second plate such that linear motion of the cable (effectuated by a motor) causes linear motion of the second plate (thereby changing the effective size of opening size or area through which air may flow). According to various other alternative embodiments, the actuator may include a rotary actuator, motor, piston, gear train, pneumatic actuator, etc. According to other alternative embodiments, the first and second aperture plates are configured to be adjusted in two directions with respect to each other. For example, the two aperture plates may slide relative to each other in two directions within the plane of the plates (such as perpendicular directions), etc.
[0033] One or more ventilation modules may be coupled to the same actuator 48 (see FIG. 2). According to a particularly preferred embodiment, actuator 48 is configured to include one or more links that allow for adjustment between connecting adjacent cooling and ventilation modules. An adjustment link may be used to rebalance or offset one ventilation module to receive more or less air than an adjacent ventilation module controlled by the same actuator.
[0034] A single actuator can control a relatively long section of ventilation modules with “plug-and-play” lengths of sheathed actuator cable (or rods or open cables). The cables may be run alongside and attached to individual ventilation modules (or linked in series), and provide for local adjustment of individual sections for air flow balancing. According to an alternative embodiment, a separate control rod may be run alongside and attached individually to multiple ventilation modules, as an alternative to connecting the extrusions end to end in series. Adjacent ventilation modules may also have removable links such that other actuators may be installed or relocated to suit room reconfiguration.
[0035] According to a particularly preferred embodiment, actuator 48 is commanded to an appropriate position (to control air jet opening sizes) by typical temperature controls such as a thermostat. According to an alternative embodiment, manual control of the actuator may be used in lieu of automated control, either for user-adjusted comfort or as an initial maximum flow balancing effort. According to another alternative embodiment, manual controls may be incorporated with automated control.
[0036] According to another alternative embodiment, air flow may be controlled by an axle parallel to and below the floor grille that rotates paddle-like dampers toward the grille's front edge to shut against the plenum pressure and towards the rear edge to expose more of the grille to plenum pressure.
[0037] Referring to FIGS. 2-4, heating module 80 includes a pocket 82 (or partition) and a heating element 84 provided in pocket 82 . According to a particularly preferred embodiment, pocket 82 comprises four side walls 92 provided on four sides of heating element 84 , and a plate 94 provided below heating element 84 . A top portion or area 86 is open to allow heated air flow through grille 22 (see FIG. 2). According to an alternative embodiment a sheet metal partition may be installed on the interior edge of the heating element and each of two ends of the heating element. This arrangement would use the floor and an adjacent building wall as the other two partition walls.
[0038] According to the particularly preferred embodiment, heating element 84 comprises a pipe 86 through which hot water flows. Fins 88 are coupled along sections of pipe 86 in pocket 82 to assist in the heat transfer from the heated water in pipe 86 to air surrounding fins 88 . As seen in FIG. 2, pipe 86 may extend along the entire length of system 10 . However, fins 88 are provided on pipe 86 only in pocket 82 . Pipe 86 may be insulated in areas outside of pocket 82 . This configuration allows unfinned pipe (typically insulated) to pass under adjacent cooling sections in a straight line.
[0039] Heating modules 80 are provided along intermittent segments of system 10 . Heating element 84 collects cool room air near an exterior wall 24 and draws it down into pocket 82 . As the air is heated in heating element 84 , it rises out into space 26 .
[0040] Heating output of heating modules 80 may be passively induced with adjacent air jets to increase the heating output of heating module 80 . For example, air supply jets provided on the ends and/or sides of the heating module induce and help disperse into the room the convective heating plume from heating module 80 (see FIG. 3).
[0041] According to an alternative embodiment, the actuator also may be linked to open a hot water control valve (not shown) to prevent the flow of hot water during cooling (i.e., configured to avoid simultaneous heating and cooling by the system). According to a further alternative embodiment, a single static side deflector/aperture deflector plate or a manually adjusted two plate deflector may be introduced to a conventional grille/plenum box (e.g. served by a conventional automatic damper and/or a duct connected to a fan terminal or other source of treated or conditioned air) to transform its performance characteristics to better suit specific under-floor air applications.
[0042] For example as shown in FIGS. 6-8, the system can utilize heated air (such as ducted or plenum air from a fan-coil or other heating source shown as duct 210 ). A conventional damper 200 is used to adjust the amount of plenum supply air flow introduced to the diffuser, and/or to mix with heated air. Furthermore, damper 200 can be used to stop air flow to the diffuser, resulting in natural convective heating (i.e., heating without external or supplied air flow); and, during low load conditions, the control of alternate damper sections can be sequenced to maintain elevated air flow rates (and thus room air induction) in active diffusers.
[0043] As best shown in FIG. 8, the first and second plates 44 and 46 , respectively can be varied to obtain a notable number of effects. Starting at the top of FIG. 8 with position A, the first plate 44 and second plate 46 are both positioned at a 0% stroke position in which all segments of the apertures 60 and 62 of the first and second plates 44 and 46 , respectively, are closed. In position B, the second plate 46 is moved to the right while the first plate 44 remains in position and a 25% stroke position is shown wherein lead segments 194 positioned toward the ends of the first and second plates 44 and 46 , respectively, (where the apertures 62 are larger and the apertures 60 have more space there between) are partially opened (shaded area showing overlap of aperture 60 and aperture 62 .) and plenum air is allowed to pass through the first and second plates 44 and 46 .
[0044] In position C, the 50% stroke position, the openings 0 of the lead segments 194 are fully open and equal to the size of the aperture 60 in the first plate 44 . In position D there is shown a 75% stroke position and all of the segments are at least partially open. In particular at position D, the lag segments 196 are partially open and the lead segments 194 remain fully open. Finally at position E, 100% actuator stroke has occurred and both the lead segments 194 and the lag segments 196 are all fully open.
[0045] Referring back to FIG. 1, system 10 includes a grille 22 which is provided on the top of system 10 . Grille 22 is flush with floor panels 14 and covers system 10 . Grille 22 allows for the passage or flow of air from system 10 to space 26 . Grille 22 may be modified to provide directional control (such as by using vanes 172 having differing angles as shown in FIG. 4) which create laterally diverging air jets. One or more supports 112 may be provided transverse to the length of grille 22 for support as well as to assist in providing directional control of air flow.
[0046] Grille 22 provided over aperture sets 60 and 62 creates multiple paths for induction of room air, first perpendicularly between aperture sets 60 and 62 , and second, laterally into the small low-pressure zones above individual grille bars 172 (see FIGS. 3 and 4). The induced air raises the temperature of the air jets and reduces the height of their vertical plumes. This maintains mixing in the occupied zone of the room, without disturbing a stratified overhead layer and yielding favorable room temperature gradients under a large range of cooling loads.
[0047] It should be appreciated that one advantage of the system shown is that the majority of the system may be installed after a raised floor has been installed. According to a particularly preferred embodiment, the system is sized to fit (in an integer width of a floor panel) between an edge of a floor panel and the exterior wall. The system may also be provided in any desired location having any planned width (including fractional widths of floor panels). Ventilation modules 40 and heating modules 80 may be dropped into the raised floor system. Heating modules 80 may be fitted with slide-type pipe supports to accept straight pipes with pre-fabricated finned segments. Solderless copper fittings may be used to connect to existing plumbing. Ventilation modules 40 would then be installed, and grilles 22 fixed in place. System 10 is advantageously configured for retrofit projects or applications.
[0048] System 10 provides an integrated solution to satisfy all building heating, ventilating and air conditioning needs through one linear floor grille assembly incorporating intermittent sections of variable-area, sliding-damper air supply inlets. This configuration assists in avoiding the energy cost and maintenance demands of under-floor fans and filters and reduces the number of components and floor plenum space involved. This configurations allows nighttime or emergency power mode perimeter heating without operating the primary under-floor air system or local fan-coils. Furthermore, it provides effective air diffusion employing nearly constant velocity under a variety of thermal loads, comfortable space conditions, a clean architectural appearance, and flexibility for open office relocations. The system reduces the number of mechanical and control components, their required space (plenum depth, floor area) and inopportune demands for access in the midst of office workstations. The system also offers “plug-and-play” features (mechanical or electronic) that simplify installation, a compact design, and a construction sequence that may shorten installation time and be well suited for retrofit projects.
[0049] It is also important to note that the construction and arrangement of the elements of the HVAC system as shown in the exemplary, preferred and alternative embodiments are illustrative only. Although only a few embodiments of the present inventions have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter recited.
[0050] For example, a variety of heating elements may be used (including electric heaters). The system is not limited to building perimeters and may also be applied in an architecturally integrated fashion to interior spaces, with or without heating involved. Other HVAC elements may be used in conjunction with the system including fan powered boxes, to increase peak heating and/or peak cooling capacities as the thermal loads of a building perimeter may require. The system also may use different grille widths as desired to suit thermal loads/exposures, and/or under-floor plenum pressure. Air deflection characteristics of the apertures, side deflectors and grille also may be selected to provide directional control.
[0051] Accordingly, all such modifications are intended to be included within the scope of the present inventions. Other substitutions, modifications, changes and omissions may be made in the design, operating conditions and arrangement of the preferred and other exemplary embodiments without departing from the spirit of the present invention.
|
An under-floor, perimeter-based heating ventilation and air conditioning pressurized air delivery system for use in a space includes a ventilation module, to be located in the floor, a multi-deflection linear bar grille covering the ventilation module, for diffusing the air entering the space, and a pair of apertured plates located below the grille, one plate moves relative to the other to either block more of the resultant apertures, so less air will flow, or to align the apertures, so more air will flow, all at nearly constant velocity and resultant plumage; nuances in aperture size or location allow one segment of the module to engage air flow on a lead-lag basis with respect to the other segments; air flow from the lead apertures induces air flow through a proximate under-floor heating module, to both increase its heat output and temper the ventilation air.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation-in-part of copending U.S. patent application (“Copending Application”), Ser. No. 13/362,620, entitled “THREE-PHASE SOFT-SWITCHED PFC RECTIFIERS,” by Jang and Jovanović, filed on Jan. 27, 2012, and assigned the attorney docket number 36977-320233. The Copending Application is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention generally relates to front-end rectifiers with power-factor correction (PFC). In particular, the present invention relates to three-phase, three-level PFC rectifiers.
[0004] 2. Discussion of the Related Art
[0005] In power converters, achieving a high efficiency in high-voltage applications is a major design challenge that requires an optimized reduction of conduction and switching losses through a careful selection of the converter topology and switching device characteristics. Specifically, a higher voltage-rated semiconductor switch exhibits larger conduction and switching losses, as compared to a counterpart with a lower voltage rating. In this context, a semiconductor switch may be any switching device, such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor), an IGBT (Insulated-Gate Bipolar Transistors), a BJT (Bipolar Junction Transistors), a SiC (Silicon-Carbide) or a GaN (Gallium-Nitride).
[0006] Generally, switching losses can be reduced and even eliminated using resonant or soft-switching techniques. However, there are only limited approaches for reducing conduction losses. In fact, once the topology and the switches with the lowest conduction losses for the required voltage rating are selected, further decrease in conduction loss is possible only by modifying the topology to utilize switches with a lower voltage rating. Multilevel converters—whose switches operate with a voltage stress that is much less than the input and output voltages—are naturally suitable for high-voltage applications.
[0007] The Copending Application describes a new, three-phase, two-switch, zero-voltage switching (ZVS), discontinuous conduction mode (DCM), PFC boost rectifier that achieves a low input-current total harmonic distortion (THD). In that PFC boost rectifier, all the switches operate under ZVS conditions, without using additional soft-switching circuitry. One implementation of the PFC rectifier of the Copending Application is shown in FIG. 1 . As shown in FIG. 1 , the PFC boost rectifier includes Y-connected capacitors C 1 , C 2 , and C 3 , which create virtual neutral node N. Virtual neutral node N has the same electrical potential as the power source's neutral terminal that is not physically available for connection in a three-wire power system. Since virtual neutral node N is connected to the node between switches S 1 and S 2 and also to the node between output capacitors C O1 and C O2 , the electrical potentials of these nodes are the same as the electrical potential of the neutral terminal in the balanced three-phase power source.
[0008] In addition, by connecting virtual neutral node N directly to the node between switches S 1 and S 2 , decoupling of the three input currents is achieved. In such a decoupled circuit, the current in each of boost inductors L 1 , L 2 and L 3 depends only on the corresponding phase voltage, which reduces the THD and increases the power factor (PF). Specifically, bridge diodes D 1 -D 6 allow only the currents in phases with positive phase voltages to flow through switch S 1 , when switch S 1 is turned on, and allow only the currents in phases with negative phase voltages to flow through switch S 2 , when switch S 2 is on. Therefore, the boost inductor corresponding to a phase in a positive voltage half-line cycle carries positive current when switch S 1 is on, while the boost inductor corresponding to a phase in a negative voltage half-line cycle carries negative current when switch S 2 is on. During the time when switch S 1 is off, the stored energy in the boost inductor connected to the positive phase voltage is delivered to capacitor C R , whereas the stored energy in the boost inductor connected to the negative phase voltage is delivered to capacitor C R during the time when switch S 2 is off. Because the voltage between either terminal of capacitor C R and virtual neutral node N abruptly changes with a high rate (i.e., a large dV/dt value) during each switching cycle, coupled inductor L C is connected between “flying” capacitor C R and the output voltage V O to isolate output voltage V O from these fast high-voltage transitions that usually produce unacceptable common-mode electromagnetic interference (EMI) noise. As shown in FIG. 1 , with coupled inductor L C , the node between output capacitors C O1 and C O2 can be directly connected to virtual neutral node N, which makes the output common-mode noise very low. Moreover, because of coupled inductor L C , parallel operations of multiple rectifiers are also possible.
[0009] To facilitate cross-reference between the figures and the detailed description, like elements are assigned like reference names or numerals.
SUMMARY
[0010] The present invention extends PFC and ZVS operations of the switches in the rectifier of FIG. 1 to three-level rectifiers that can utilize switches with a lower voltage rating and, consequently, a lower conduction loss.
[0011] According to one embodiment of the present invention, three-phase, three-level PFC rectifier topologies utilize switches with a lower voltage rating and offer improved performance over the prior art because of lower conduction losses. In one preferred embodiment, an input stage consists of three boost inductors L 1 , L 2 , and L 3 coupled to the three-phase input terminals and capacitors C 1 , C 2 , and C 3 connected in a Y or “star” configuration. Common node N of the capacitors is connected to a node between serially-connected switch pairs S 1 -S 2 and S 3 -S 4 and also to a node between serially connected output split capacitors C O1 and C O2 . A node between serially-connected switches S 1 -S 2 is connected to output capacitor C O1 through clamping diode D C1 . A node between serially-connected switches S 3 -S 4 is connected to output capacitor C O2 through clamping diode D C2 . Capacitor C R , which resets the currents in the boost inductors, is connected across serially connected switches S 1 -S 4 and output V O by coupled or non-coupled inductor L C .
[0012] The rectifiers of the present invention offer a low THD in the input currents and a high PF. The rectifiers provide high efficiency power conversion using soft-switching techniques over a wide load range. This high efficiency is achieved by operating the boost inductors in DCM and by controlling the output voltages in the rectifiers using variable-frequency control. In addition, the PFC rectifiers of the present invention exhibit a reduced common-mode noise and possess automatic balancing of split capacitors C O1 and C O2 , when serially-connected downstream converters are employed.
[0013] In one implementation, galvanic isolation between the input signal and the output signal is achieved using transformer TR, instead of coupled inductor L C . At the secondary side of transformer TR, rectifiers D O1 and D O2 and output filter including inductor L O and capacitor C O are coupled between the secondary winding of transformer TR and output voltage V O . By employing additional phase-shift or PWM control, the isolated implementations can tightly control their output voltages. Circuits may also be interleaved to increase their power handling capabilities and reduce their input or output current and voltage ripples.
[0014] The present invention is better understood upon consideration of the following detailed description and the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 shows a three-phase, two-switch, ZVS, PFC DCM boost rectifier.
[0016] FIG. 2 shows a three-phase three-level ZVS PFC DCM boost rectifier, according to an embodiment of the present invention.
[0017] FIGS. 3( a )- 3 ( c ) each show, under one of three different control schemes, gating waveforms of switches S 1 -S 4 of FIG. 2 during a switching cycle, according to an embodiment of the present invention.
[0018] FIG. 4 shows a simplified model of the circuit in FIG. 2 , annotated with reference directions of currents and voltages, according to an embodiment of the present invention.
[0019] FIGS. 5( a )- 5 ( n ) show topological stages illustrating voltages and currents in the model of FIG. 4 during a switching cycle, according to an embodiment of the present invention.
[0020] FIG. 6 shows the key waveforms in the model of FIG. 4 , according to an embodiment of the present invention.
[0021] FIG. 7 shows a three-phase three-level ZVS PFC DCM boost rectifier with two independent loads, according to an embodiment of the present invention.
[0022] FIG. 8 shows a three-phase three-level ZVS PFC DCM boost rectifier with two independent inductors, according to an embodiment of the present invention.
[0023] FIG. 9 shows a three-phase three-level ZVS PFC DCM boost rectifier with a blocking capacitor between a virtual neutral node and the node between two split output capacitors, according to an embodiment of the present invention.
[0024] FIG. 10 shows a three-phase three-level ZVS PFC DCM boost rectifier in which snubber capacitors C S1 , and C S4 are connected in parallel to switches S 1 and S 4 , according to one embodiment of the present invention.
[0025] FIG. 11 shows three-phase three-level ZVS PFC DCM boost rectifiers supporting parallel or interleaved operations, according to an embodiment of the present invention.
[0026] FIG. 12 shows interleaved three-phase three-level ZVS PFC DCM boost rectifiers including DC current blocking capacitor C B , according to an embodiment of the present invention.
[0027] FIG. 13 shows interleaved three-phase three-level ZVS PFC DCM boost rectifiers including DC current blocking capacitors C B1 and C B2 and input filter capacitor sets C 1 -C 3 and C 4 -C 6 , according to an embodiment of the present invention.
[0028] FIG. 14 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with two transformers and an additional phase-shift control scheme, according to an embodiment of the present invention.
[0029] FIG. 15 shows gating waveforms of switches S 1 -S 8 of the circuit in FIG. 14 during a switching cycle, according to an embodiment of the present invention.
[0030] FIG. 16 shows another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifiers with two transformers and an additional phase-shift control scheme, according to an embodiment of the present invention.
[0031] FIG. 17 shows gating waveforms of switches S 1 -S 8 of the circuit in FIG. 16 during a switching cycle, according to an embodiment of the present invention.
[0032] FIG. 18 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with transformer TR and split flying capacitors C R1 and C R2 , according to an embodiment of the present invention.
[0033] FIG. 19 shows gating waveforms of switches S 1 -S 4 in the circuit of FIG. 18 during a switching cycle, according to an embodiment of the present invention.
[0034] FIG. 20 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with a transformer and clamping diodes coupled to a node between split flying capacitors, according to an embodiment of the present invention.
[0035] FIG. 21 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter that uses the leakage inductances of the coupled inductor as auxiliary boost inductors, according to an embodiment of the present invention.
[0036] FIG. 22 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter having auxiliary boost inductors L H1 and L H2 , according to an embodiment of the present invention.
[0037] FIG. 23 shows another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter that uses the leakage inductances of the coupled inductor as auxiliary boost inductors, according to an embodiment of the present invention.
[0038] FIG. 24 shows yet another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter having auxiliary boost inductors L H1 and L H2 , according to an embodiment of the present invention.
[0039] FIG. 25 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with a full-bridge primary configuration and transformers TR 1 and TR 2 , according to an embodiment of the present invention.
[0040] FIG. 26 shows another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with a full-bridge primary configuration and a transformer, according to an embodiment of the present invention.
[0041] FIG. 27 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with coupled two half-bridge primary configuration and series connected two transformers, according to an embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] FIG. 2 is a block diagram of a three-phase, three-level ZVS PFC DCM low input-current-harmonic boost rectifier according to an embodiment of the present invention. The input stage of the circuit in FIG. 2 includes boost inductors L 1 , L 2 , and L 3 coupled to capacitors C 1 , C 2 , and C 3 connected in a Y (“star”) configuration. The input stage of the circuit may also include an EMI filter (not shown in FIG. 2 ) at the three-phase input terminals. The common node N of capacitors C 1 , C 2 , and C 3 is connected to a node between serially-connected switch pairs S 1 -S 2 and S 3 -S 4 and also to a node between split output capacitors C O1 and C O2 . The node between serially-connected switches S 1 -S 2 is connected to output capacitor C O1 through clamping diode D C1 , so that the voltage across switch S 2 is clamped to the voltage across capacitor C O1 , which is preferably one half of output voltage V O . The node between serially-connected switches S 3 -S 4 is connected to output capacitor C O2 through clamping diode D C2 and the voltage across switch S 3 is also clamped to one-half of output voltage V O , preferably. Clamping capacitor C C is connected across split output capacitors C O1 and C O2 , and is pre-charged to its steady-state average voltage of one-half of the output voltage through the loop consisting of capacitor C O2 , the body diode of switch S 2 , pre-charge resistor R PR , and a winding of coupled inductor L C . Capacitor C R which resets the boost inductor currents is connected across serially-connected pairs of switches S 1 -S 2 and S 3 -S 4 , and is decoupled from output voltage V O by inductor L C . The average voltage across capacitor C R is equal to output voltage V O since the average voltage across the windings of L C is zero. The voltages across switches S 1 and S 4 are clamped to the difference in voltage across capacitor C R and C C by the body diodes of switch S 4 and switch S 1 . Since this difference in voltage is equal to one-half of output voltage V O , the voltage across each of the four switches S 1 -S 4 in the circuit in FIG. 2 is one-half of output voltage V O . Generally, any kind of switch that is capable of conducting current in both directions and blocking voltage in one direction with an antiparallel diode (e.g., a MOSFET or an IGBT) is suitable for this application.
[0043] The Y-connected capacitors C 1 , C 2 , and C 3 create virtual ground node N, i.e., a node with the same electrical potential as the input (source) voltage neutral wire that is not physically available or connected in a three-wire power system. By connecting virtual neutral node N directly to the nodes between switch pairs S 1 -S 2 and S 3 -S 4 , decoupling of the three input currents is achieved. In such a decoupled circuit, the current in each of boost inductors L 1 , L 2 and L 3 depends only on the corresponding phase voltage, which reduces the THD and increases the PF. Specifically, in the circuit in FIG. 2 , bridge diodes D 1 -D 6 allow only a positive input voltage to deliver currents through series connected switches S 1 and S 2 when these switches are turned on and a negative input voltage to deliver currents through series connected switches S 3 and S 4 when these switches are turned on. The switches may each be turned on at a substantially zero voltage across the switches. Therefore, any boost inductor in a phase with a positive voltage half-line cycle carries positive current when switches S 1 and S 2 are on, while any boost inductor in a phase with a negative voltage half-line cycle carries negative current when switches S 3 and S 4 are turned on. During the time when switches S 1 and S 2 are turned off, the stored energy in the boost inductor connected to the positive phase voltage is delivered to capacitor C R , while the stored energy in the boost inductor connected to the negative phase voltage is delivered to capacitor C R during the time when switches S 3 and S 4 are turned off.
[0044] Because in every switching cycle the voltage across capacitor C R changes rapidly (i.e., with a large dV/dt value), coupled inductor L C connects between “flying” capacitor C R and output voltage V O to isolate output voltage V O from these fast high-voltage transitions that usually produce unacceptable common-mode EMI noise. With coupled inductor L C , the output common-mode noise is very low, as the noise is confined to the S 1 -S 2 -S 3 -S 4 -C R loop. Moreover, because coupled inductor L C provides impedance between output voltage V O and switches S 1 -S 4 , parallel or interleaving operations of multiple rectifiers are possible.
[0045] To achieve a low input-current THD, high PF, and soft-switching of switches S 1 -S 4 over a wise load range, the circuit in FIG. 2 must operate in DCM with a low-bandwidth output-voltage control scheme. This control scheme can be implemented in a variety of ways. FIG. 3( a ) shows gating waveforms for controlling switches S 1 -S 4 in FIG. 2 under a variable switching-frequency control scheme. Under the variable-frequency control scheme of FIG. 3( a ), switch pairs S 1 -S 2 and S 3 -S 4 are switched in a complementary fashion, with a small dead time t d between their commutation instants to enable the switch pair that is about to turn on to achieve ZVS. Since dead time t d is very small in comparison with switching period T S , the effect of the dead time on the duty cycle is negligible, i.e., the duty cycle of each switch pair is approximately 50%.
[0046] FIG. 3( b ) shows a second control scheme for switches S 1 -S 4 of FIG. 2 . Under this second control scheme, switches S 1 and S 4 are switched at a constant frequency in a complementary fashion with a small dead time in-between, i.e., each switch operates at an approximate 50% duty cycle. Switches S 2 and S 3 , whose turn-on instants are synchronized with the turn on instants of S 1 and S 4 , respectively, are each pulse-width modulated to provide regulation of output voltage V O .
[0047] FIG. 3( c ) shows a third alternative control scheme for switches S 1 -S 4 of FIG. 2 . Under this third control scheme, in each of switch pairs S 1 -S 4 and S 2 -S 3 , the switches within the switch pair are switched at a constant frequency in a complementary fashion with a fixed duty cycle of approximately 50%. The control scheme provides a phase shift between the switching instants of the S 1 -S 4 pair and the corresponding switching instants of the S 2 -S 3 pair. In this phase-shift control scheme, the output voltage is zero when the phase shift is zero and reaches a maximum when the phase shift is 180 0 (i.e., when the phase shift is T S /2).
[0048] The control schemes illustrated in FIGS. 3( a )-( c ) may be used in a combination. Namely, the variable switching frequency control scheme of FIG. 3( a ) can be used in any combination with the constant frequency PWM control scheme of FIG. 3( b ), or with the phase-shift control scheme of FIG. 3( c ), to limit the switching frequency range. For example, in the output voltage-regulated converter of FIG. 2 , the switching frequency increases as the load decreases. Thus, the frequency range can be reduced by a variable switching-frequency control scheme at full and medium loads, while switching over to a constant frequency control scheme at lighter loads.
[0049] FIG. 4 shows a simplified model of the circuit of FIG. 2 , annotated with reference directions of currents and voltages, according to an embodiment of the present invention. To simplify analysis, ripple voltages of the input and output filter capacitors in FIG. 2 (i.e., capacitors C 1 , C 2 , C 3 , C O1 and C O2 ) are considered negligible in this model, so that the voltage across the input and output filter capacitors can be represented by constant-voltage source V AN , V BN , V CN , V O1 , and V O2 . Also, in the on state, the semiconductor switches exhibit zero resistance (i.e., they are short circuits). However, the output capacitances of the switches are not neglected in this model. Coupled inductor L C in FIG. 2 is modeled as a two-winding ideal transformer with magnetizing inductance L M and leakage inductances L LK1 and L LK2 . In this model, the average voltage across flying capacitor C R is substantially equal to output voltage V O =V O1 +V O2 and the average voltage across clamping capacitor C C is substantially equal to one half of output voltage V O . The reference directions of currents and voltages in FIG. 4 correspond to a 60-degree segment of the line cycle (i.e., when V AN >0, V BN <0, and V CN <0).
[0050] FIGS. 5( a )- 5 ( n ) show topological stages illustrating voltages and currents in the model of FIG. 4 during a switching cycle, according to an embodiment of the present invention. FIG. 6 shows the key waveforms in the model of FIG. 4 , according to an embodiment of the present invention.
[0051] The waveforms of the gating signals of switches S 1 -S 4 in FIG. 6 show that the control scheme used combines a variable-frequency control scheme and a constant-frequency phase-shift control scheme. In FIG. 6 , switches S 1 and S 4 operate in a complementary manner. Likewise, switches S 2 and S 3 operate in a complementary manner. In either case, a short dead time is provided between the commutation instants (i.e., each switch operates with a fixed duty cycle of approximately 50%). This gating strategy enable ZVS in the switches that are about to turn on. To regulate output voltage V O in the presence of input voltage and output load variations, a variable switching frequency control scheme is employed. However, to limit the control-frequency range and the consequential switching losses, the variable-frequency control scheme is assisted by a phase-shift control scheme at light loads or high input voltage, or both.
[0052] In the model of FIG. 4 , the minimum frequency occurs when both a full load and the minimum input voltage are present, while duty cycle is set substantially at 50%. The maximum frequency occurs when a light load and maximum input voltage are present, while duty cycle is set below 50%. If necessary, the rectifier of the present invention can operate in a controlled burst mode or pulse skip mode at no load or at a very light load, to avoid operation at an unnecessarily high switching frequency. Other control strategies could also be applied to this circuit, including constant-frequency PWM control and phase-shift control as shown in FIGS. 3( b ) and 3 ( c ) discussed above.
[0053] Referring to FIGS. 5( a ) and 6 , before switch S 2 is turned off at t=T 1 , inductor current i L1 flows through closed switches S 1 and S 2 . The slope of inductor current i L1 is equal to V AN /L 1 and the peak of the inductor current at t=T 1 is approximately
[0000]
I
L
1
(
PK
)
=
V
AN
L
1
×
DT
S
,
(
1
)
[0000] where V AN is line-to-neutral voltage and DT S is the portion of the switching period T S during which switches S 1 and S 2 are both closed (i.e., D is the effective duty cycle). Because the dead time between the turning-off of switch S 1 and the turning-on of switch S 4 is very short relative to switching period T S , the effect of the dead time is neglected in Equation (1). During the period between times T O and T 1 , current i O1 decreases at a rate of −V O1 /(L M +L LK1 ) while current i O2 increases at a rate of (V CR −V O1 )/(L M +L LK2 ). Magnetizing current i M is the difference between currents i O1 and i O2 .
[0054] The magnetizing inductance value of coupled inductor L M is selected to be sufficiently large, such that its ripple current does not significantly affect rectifier operation. As shown in FIG. 2 , the windings of inductor L C are coupled in such a way as to cancel the magnetic fluxes from the differential current of the two windings, so that the large magnetizing inductance can be achieved by a small gap in the core without saturation. Since the ripples in currents i O1 and i O2 are considered negligible in this model, further discussion is omitted, although the ripple currents are still shown in the topological stages in FIG. 5 .
[0055] At t=T 1 , switch S 2 turns off, inductor current i L1 begins to charge the parasitic output capacitance of switch S 2 ( FIG. 5( b )). As the sum of the voltages across switches S 2 and S 3 is clamped to clamping capacitor voltage V CC , the output capacitance of switch S 3 discharges at the same rate as the output capacitance of switch S 2 is being charged until the output capacitance of switch S 2 is fully charged and clamping diode D C1 starts to conduct at t=T 2 , as shown in FIG. 5( c ) and FIG. 6 . Shortly after t=T 2 , switch S 3 turns on under ZVS condition.
[0056] During interval [T 2 , T 3 ], because clamping diode D C1 is forward biased, inductor current i L1 linearly decreases. The slope of inductor current i L1 is equal to (V AN −V O1 )/L 1 and the inductor current at t=T 3 is approximately
[0000]
I
L
1
|
t
=
T
3
=
V
AN
-
(
1
-
2
D
)
V
O
1
2
L
1
×
T
S
,
(
2
)
[0057] At t=T 3 , when switch S 1 turns off, inductor current i L1 begins charging the output capacitance of switch S 1 , as shown in FIG. 5( d ). Because the sum of the voltages across switches S 1 and S 4 is clamped to the voltage difference between flying capacitor voltage V CR and clamping capacitor voltage V CC , the output capacitance of switch S 4 discharges at the same rate as the output capacitance of switch S 1 is charged, until the output capacitance of switch S 4 is fully discharged and the anti-parallel body diode of switch S 4 starts to conduct at t=T 4 , as shown in FIG. 5( e ) and FIG. 6 . At t=T 5 , switch S 4 turns on a ZVS condition and inductor current i L1 is commutated from the antiparallel body diode of switch S 4 to the switch, as illustrated in FIG. 5( f ). Because the body diode of switch S 4 is forward biased and switch S 3 is switched on, inductor currents i L2 and 4 3 begin to linearly increase after t=T 4 . At t=T 5 , switch S 4 turns on under a ZVS condition and inductor currents i L2 and i L3 are commutated from the antiparallel body diode of switch S 4 to the switch, as illustrated in FIG. 5( f ), until inductor current i L1 decreases to zero at t=T 6 . To maintain DCM operation, the minimum voltage V CR (MIN) across “flying” capacitor C R , which is equal to output voltage V O , is provided by:
[0000]
V
CR
(
MIN
)
=
V
AN
(
PK
)
1
-
D
=
2
3
(
1
-
D
)
×
V
L
-
L
,
RMS
(
3
)
[0000] where V AN-PK is the peak line-to-neutral voltage.
[0058] During the T 4 -T 6 interval, because inductor currents i L2 and i L3 both flow in an opposite direction from inductor current i L1 , the average current through switches S 3 and S 4 is reduced, resulting in reduced power losses in the switches.
[0059] During the period between t=T 6 and t=T 7 , inductor currents i L2 and i L3 continue to flow through switches S 3 and S 4 , as illustrated in FIG. 5( g ). As shown in FIG. 6 , the slopes of inductor currents i L2 and i L3 during this period are equal to −V BN /L 2 and −V CN /L 3 , respectively. The peaks of the inductor currents at the moment when switch S 3 turns off at t=T 7 are approximately
[0000]
I
L
2
(
PK
)
=
-
V
BN
L
2
×
DT
S
and
(
3
)
I
L
3
(
PK
)
=
-
V
CN
L
3
×
DT
S
.
(
4
)
[0000] Therefore, as seen from Equations (1), (3), and (4), the peak inductor current is proportional to its corresponding input voltage, as long as duty cycle D is substantially constant during one half of the line cycle.
[0060] After switch S 3 turns off at t=T 7 , inductor currents i L2 and i L3 start to simultaneously charge the output capacitance of switch S 3 and discharge the output capacitance of switch S 2 , as shown in FIG. 5( h ), until t=T 8 , when the output capacitance of switch S 3 is fully charged and clamping diode D C2 starts to conduct at t=T 8 , as shown in FIG. 5( i ) and FIG. 6 . After t=T 8 , switch S 2 turns on under a ZVS condition.
[0061] At time t=T 8 , because clamping diode D C2 is forward biased, inductor currents i L2 and i L3 begin to linearly increase until inductor current i L3 reaches zero at time t=T 9 . The slopes of inductor currents i L2 and i L3 are equal to (−V BN +V O2 )/L 2 and (−V CN +V O2 )/L 3 , respectively. Inductor current i L2 at t=T 10 , when switch S 4 turns off, is approximately
[0000]
I
L
2
|
t
=
T
10
=
-
V
BN
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[0062] At t=T 10 , when switch S 4 turns off, inductor current i L2 starts to charge the output capacitance of switch S 4 , as shown in FIG. 5( k ). Because the sum of the voltages across switches S 1 and S 4 is clamped to the voltage difference between flying capacitor voltage V CR and clamping capacitor voltage V CC , the output capacitance of switch S 1 discharges at the same rate as the output capacitance of switch S 4 is being charged, until the output capacitance of switch S 1 is fully discharged and the anti-parallel body diode of switch S 1 starts to conduct at t=T 11 , as shown in FIG. 5( l ) and FIG. 6 . At t=T 12 , switch S 1 turns on under a ZVS condition and inductor currents i L2 is commutated from the antiparallel body diode of switch S 1 to the switch itself, as shown in FIG. 5( m ). At this time, because switches S 1 and S 2 are both on, inductor current i L1 begins to linearly increase after t=T 11 . During period T 12 -T 13 . increasing inductor current i L2 , continues to flow through switches S 1 and S 2 , as shown in FIG. 5( m ). Finally, after inductor current i L2 reaches zero at t=T 13 , a new switching cycle begins, as shown in FIG. 5( n ).
[0063] The harmonic content of the average inductor currents i L1 -i L3 shown in FIG. 6 is dominated by the 3 rd harmonic. However, as the neutral wire in a three-wire power system is not available (or not connected), the phase currents cannot contain the triplen harmonics (the 3 rd harmonic and the odd multiples of the 3rd harmonic). As a result, the circuit of the present invention exhibits a very low THD and a high PF, as the remaining harmonics contribute less than 1-2% of total current distortion.
[0064] A PFC rectifier of the present invention may be implemented in many ways. For example, FIG. 7 shows an implementation supporting independent loads R 1 and R 2 . Since the two-switch rectifier automatically balances the voltages across output capacitors C O1 and C O2 , no additional voltage-balancing circuit is required. Natural voltage-balancing is achieved because in the circuit in FIG. 7 , the average voltages across switch pairs S 1 -S 2 and S 3 -S 4 are equal to voltages V O1 and V O2 across capacitors C O1 and C O2 , respectively, as the average voltages across the windings of inductor L C are zero. The average voltages of switch pairs S 1 -S 2 and S 3 -S 4 are equal to V CR /2, so that V O1 =V O2 =V CR /2.
[0065] Alternatively, the circuits of the present invention may also be implemented using independent inductors L C1 and L C2 , as shown in FIG. 8 , or with blocking capacitor C B , as shown in FIG. 9 . By coupling blocking capacitor C B between virtual neutral node N and output capacitors C O1 and C O2 ( FIG. 9 ), low frequency currents circulating between virtual neutral node N, switches S 2 and S 3 and the common node between capacitors C O1 and C O2 can be reduced.
[0066] FIG. 10 shows an embodiment in which snubber capacitors C S1 and C S4 are connected in parallel with switches S 1 and S 4 . By adding snubber capacitors C S1 and C S4 , turn-off losses in switches S 1 and S 4 can be significantly reduced.
[0067] FIG. 11 shows a circuit of the present invention that combines two sub-circuits (“PFC stages”) which operate in parallel or are interleaved, in accordance with one embodiment of the present invention. The PFC stages in FIG. 11 each include an input portion of the circuit similar to that shown in FIG. 2 (from the three-phase input voltage up to coupled inductor L C ). In parallel operation, switches S 1 , S 2 , S 5 , and S 6 are driven by a first gating signal, while switches S 3 , S 4 , S 7 , and S 8 are driven by a second gating signal that is complementary the first gating signal. In an interleaved operation, switches S 1 , S 2 , S 7 , and S 8 are driven by the first gating signal, while switches S 3 , S 4 , S 5 , and S 6 are driven by the second gating signal. The parallel and interleaved operations are made possible by coupled inductors L C1 and L C2 , which provide decoupling impedances between the output portion and the switches.
[0068] FIG. 12 shows an interleaved three-phase three-level ZVS PFC DCM boost rectifier including DC current blocking capacitor C B , according to one embodiment of the present invention. By including blocking capacitor C B , a DC current circulating between the common nodes of switches S 2 , S 3 , S 6 , and S 7 and the common node of output capacitors C O1 and C O2 can be prevented.
[0069] FIG. 13 shows an interleaved three-phase three-level ZVS PFC DCM boost rectifier including DC current blocking capacitors C B1 and C B2 and input filter capacitor sets C 1 -C 3 and C 4 -C 6 , according to one embodiment of the present invention.
[0070] FIG. 14 shows three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier including transformers TR, and TR 2 and an additional phase-shift control scheme. A tightly controlled output voltage can be achieved without additional switches, when two isolated PFC rectifiers are connected in parallel. As shown in FIG. 14 , transformers TR 1 and TR 2 replace coupled inductors L C1 and L C2 of FIG. 13 . On the secondary side of transformers TR 1 and TR 2 , rectifiers D O1 -D O4 and the output filter formed by inductor L O and capacitor C O are coupled between the serially-connected secondary windings of transformers TR 1 and TR 2 and output voltage V O . Furthermore, using an additional phase-shift or PWM control scheme, the isolated circuits connected to the primary windings of transformers TR 1 and TR 2 can tightly control the output voltages to minimize unnecessary voltage ripples.
[0071] FIG. 15 shows gating waveforms of switches S 1 -S 8 for the circuit of FIG. 14 . Switches S 1 and S 2 of the first PFC stage turn on before switches S 7 and S 8 of the second PFC stage turn off. This phase shift between the two set of switches creates PWM voltage waveforms V P1 and V P2 across the primary windings of transformers TR 1 and TR 2 , as shown in FIG. 15 . Switches S 2 , S 3 , S 6 , and S 7 turn off slightly earlier than switches S 1 , S 4 , S 5 , and S 8 turn off, which ensures that the switch voltages be clamped to one-half of the output voltage V O . Switches S 1 -S 8 operate with a slowly varying switching frequency and near 50% duty cycle to achieve high PF and low THD, while the phase shift is used to tightly regulate the output voltage.
[0072] FIG. 16 shows another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with two transformers and an additional phase-shift control scheme. The circuit of FIG. 16 is implemented using clamping diodes D C1 and D C2 that connect both the node between switches S 1 and S 2 and the node between switches S 3 and S 4 to the common node between split flying capacitors C R1 and C R2 , so as to clamp the voltages across switches S 1 and S 4 , respectively. The circuit of FIG. 16 is also implemented with the secondary windings of transformers TR 1 and TR 2 connected in series to provide current sharing.
[0073] FIG. 17 shows gating waveforms of switches S 1 -S 8 for the circuit in FIG. 16 . Switches S 1 and S 2 of the first PFC stage turn on before switches S 7 and S 8 of the second PFC stage turn off. The phase shift between the two switching instants creates PWM voltage waveforms V P1 and V P2 across the primary windings of transformers TR 1 and TR 2 , as shown in FIG. 17 . Switches S 1 , S 4 , S 5 , and S 8 turn off slightly earlier than switches S 2 , S 3 , S 6 , and S 7 turn off, which ensures that the switch voltages are clamped to one-half of output voltage V O .
[0074] Generally, most off-line power supplies of today have two cascaded stages—a front-end PFC rectifier stage and an output isolated dc-dc converter stage. As a result, although the output voltage of the front-end PFC rectifier contains rectified line frequency voltage ripples, the secondary isolated dc-dc converter stage can regulate its output voltage by its own high-frequency bandwidth feedback control. A single-stage approach combines the functions of the two cascaded stages. As a result, a single-stage rectifier should achieve PFC as well as tight regulation of the output voltage.
[0075] FIG. 18 shows a single-stage rectifier with an isolated output. The primary side of the isolated circuit of FIG. 18 is similar to the circuit of FIG. 2 , except that the circuit in FIG. 18 includes flying capacitors C R1 and C R2 and additional transformer TR that has a primary winding and a center-tap secondary winding. On the secondary side of transformer TR, rectifiers D O1 and D O2 and output filter components L O and C O are coupled between the secondary winding of transformer TR and output voltage V O . To achieve high PF and low THD, the switching frequency of switches S 1 -S 4 are kept nearly constant during a half cycle of the line frequency. To keep the switching frequency substantially constant, a low-pass filter may be included in the path of the frequency-control feedback loop. As a result, the bandwidth of the frequency control feedback loop is lower than the line frequency, which produces significant voltage ripples across flying capacitor C R1 and C R2 at rectified line frequency (e.g., six times higher frequency than the fundamental frequency of the line). However, a tight regulation of the output voltage is achieved by an additional a high-pass filter in the path of the phase-shift or PWM high-band-width control feedback loop.
[0076] FIG. 19 shows gating waveforms of switches S 1 -S 4 for the circuit of FIG. 18 . The gating signals of switches S 1 and S 4 are phase shifted with respect to the corresponding gating signals of switches S 2 and S 3 . This phase shift creates PWM voltage waveforms across the primary windings of transformer TR. Switches S 1 -S 4 operate with a slowly varying switching frequency and near 50% duty cycle to achieve high PF and low THD, while the variation of the phase shift is used to tightly regulate the output voltage.
[0077] FIG. 20 shows another three-phase, three-level single-stage isolated ZVS PFC DCM boost rectifier with a transformer and an additional phase-shift control scheme. The circuit is implemented by connecting clamping diodes D C1 and D C2 to the node between split flying capacitors C R1 and C R2 , so as to clamp the voltages across switches S 1 and S 4 , respectively.
[0078] FIG. 21 shows yet another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter that consists of switch S H and diodes D H1 and D H2 . The leakage inductances of coupled inductor L C serve as a boost inductor for the auxiliary boost converter. The auxiliary boost converter begin operating immediately after the tree-phase input voltage goes to zero, to extend the output voltage regulation time.
[0079] FIG. 22 shows another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter that consists of switch S H , diodes D H1 and D H2 , and auxiliary boost inductors L H1 and L H2 .
[0080] FIG. 23 shows yet another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter that consists of switch S H , diodes D H1 -D H3 , and auxiliary boost inductors L H1 and L H2 . In FIG. 23 , series diode D H1 of FIG. 22 that connects between input bridge diodes D 1 -D 3 and switch S 1 has been eliminated. This approach is desirable for applications that require high efficiency operation. The leakage inductances of coupled inductor L C serve as a boost inductor of the auxiliary boost converter.
[0081] FIG. 24 shows another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with an auxiliary boost converter that consists of switch S H , diodes D H1 -D H4 , and auxiliary boost inductors L H1 and L H2 .
[0082] FIG. 25 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with switches S 1 -S 8 and an isolated output, according to one embodiment of the present invention. The primary side of the isolated circuit in FIG. 25 is similar to the circuit of FIG. 2 , except that the circuit has split flying capacitors C R1 and C R2 , auxiliary switches S 5 -S 8 , additional clamping diodes D C3 and D C4 , and series connected transformers TR 1 and TR 2 each consisting of a primary winding and a center-tap secondary winding. On the secondary side of transformers TR 1 and TR 2 , rectifiers D O1 -D O4 and output filter components L O1 , L O2 and C O are coupled between the secondary windings of transformers TR 1 and TR 2 and the output. Blocking capacitor C B is connected in series with transformers TR 1 and TR 2 to eliminate any DC current through the primary windings of the transformers. The controller operates main switches S 1 -S 4 and auxiliary switches S 5 -S 8 to achieve frequency and phase-shift control, using the gating signal waveforms in FIGS. 15 and 17 . The isolated single-stage implementation can achieve a tight control of its output voltage in addition to high PF and low THD.
[0083] FIG. 26 shows another three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with switches S 1 -S 8 and an isolated output, according to an embodiment of the present invention. The primary side of the isolated circuit in FIG. 26 is similar to the circuit of FIG. 2 , except for split flying capacitors C R1 and C R2 , auxiliary switches S 5 -S 8 , additional clamping diodes D C3 and D C4 , and transformer TR that consists of a primary winding and a center-tap secondary winding. On the secondary side of transformer TR, rectifiers D O1 -D O2 and output filter components L O and C O are coupled between the secondary windings of transformer TR and output voltage V O . Blocking capacitor C B is connected in series with transformer TR to eliminate any dc current flowing through the primary windings of transformer TR.
[0084] FIG. 27 shows a three-phase three-level single-stage isolated ZVS PFC DCM boost rectifier with coupled half-bridge primary configurations and series connected transformers TR 1 and TR 2 , according to one embodiment of the present invention.
[0085] Although the isolated circuits shown in FIGS. 14-27 show the output circuit with a center-tap secondary winding of the transformer and two output diodes, the output circuit may also be implemented using any known output rectifier topology, such as the current doubler rectifier, the full-bridge rectifier, the half-bridge with voltage doubler capacitors, within the scope of the present invention. In addition, a synchronous rectifier can be employed instead of low-voltage diode rectifiers.
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A low input-current-harmonic three-phase three-level boost rectifier includes an input stage for receiving a three-phase input voltage in relation to a neutral node and an output stage adapted to couple to at least one load. The rectifier further includes one or more switching converter stages, each having a plurality of serially-connected switches coupled to the neutral node, one of the serially-connected switches operating with a fixed duty cycle while the other of the serially-connected switches operating with a variable duty cycle, the fixed duty cycle being a substantially 50% duty cycle and the variable duty cycle being less than or equal to a substantially 50% duty cycle. The serially-connected switches are coupled to clamping diodes and clamping capacitors. The rectifier further includes one or more controllers adapted to vary the switching frequency and/or duty cycle of the plurality of switches based on at least one of a condition of the at least one load or the input voltage and includes one or more decoupling stages, each including one or more inductive elements adapted to inductively decouple the output stage from at least one of the one or more switching converter stages.
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FIELD OF THE INVENTION
[0001] The present invention relates to a tow bar assembly and more particularly to a tow bar assembly including a torsion spring disposed between the tow bar and steering arm-to urge the tow bar towards an operating position.
BACKGROUND OF THE INVENTION
[0002] It is known generally to draw trailers with a tow bar. In the aviation industry, for example, trailered ground power units and other trailers are frequently coupled to a towing vehicle by a tow bar. It is also known in this and other applications to pivotally couple the tow bar to a steering arm of the trailer to permit positioning the tow bar between raised and lowered positions. The tow bar is generally lowered to a substantially horizontal position for coupling to the towing vehicle, and raised to a generally vertical position to eliminate any obstruction posed thereby and to facilitate stowage thereof when not coupled to the towing vehicle.
[0003] Prior art tow bars have the disadvantage that, when lowered, the tow bar tends to pivot downwardly until an end thereof strikes the ground. It is undesirable for the tow bar to contact the ground as the tow bar may become damaged, particularly the end portion thereof that hitches to the towing vehicle. In addition, if dropped, the tow bar can cause injury to an operator's foot.
[0004] When being connected to the towing vehicle, the tow bar must be raised upwardly from the ground. Raising the tow bar and bearing the weight of the tow bar during alignment with the vehicle hitch is inconvenient, and in some applications may require substantial physical exertion.
[0005] It would be desirable produce a tow bar assembly where the force required to raise the tow bar is minimized.
SUMMARY OF THE INVENTION
[0006] Consistent and consonant with the present invention, a tow bar assembly where the force required to raise the tow bar is minimized, has surprisingly been discovered.
[0007] The tow bar assembly comprises a tow bar having a first end, the tow bar adapted to be coupled with a towing vehicle, the first end of the tow bar having at least one aperture formed therein; a pin supported by a steering arm of a towed vehicle, the pin disposed in the at least one aperture of the tow bar to facilitate a pivotal movement of the tow bar about the pin; a spring supported by the pin and having a first linear spring extension and a second linear spring extension, the first spring extension extending outwardly from the spring into contact with the tow bar to urge the tow bar in an upward direction, the second spring extension adapted to contact the steering arm of the towed vehicle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The above, as well as other objects, features, and advantages of the present invention will be understood from the detailed description of the preferred embodiments of the present invention with reference to the accompanying drawings, in which:
[0009] FIG. 1 is an exploded partial perspective view of a tow bar and a steering arm assembly and an insertion assist pin in accordance with the present invention; and
[0010] FIG. 2 is a partial plan view of the tow bar illustrated in FIG. 1 , with a hitch pin removed and a portion of the steering arm cut away.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0011] Referring now to FIGS. 1 and 2 , there is shown generally at 10 a tow bar and steering arm assembly in accordance with the present invention. The tow bar and steering arm assembly 10 includes an elongate tow bar or draw bar 12 , a torsion spring 14 , and a steering arm 16 . In the embodiment shown, the tow bar 12 includes a pair of spaced apart longitudinally extending side rails or edge portions 18 . A first end 20 of each of the side rails 18 has a laterally extending aperture 22 formed therein. A web 24 extends between the pair of side rails 18 to form an inverted unshaped channel. A first end 26 of the web 24 is spaced from the first end 20 of the side rails 18 to expose the apertures 22 . The apertures 22 of the side rails 18 of the tow bar 12 are aligned to receive a hitch pin or bolt 28 therein. The other end of the tow bar 12 is adapted to be connected to a towing vehicle (not shown).
[0012] The torsion spring 14 is formed by a series of helically wound coils defining an open interior 30 . The hitch pin 28 is received in the interior 30 of the spring 14 . A first end or extension 32 of the spring 14 extends radially outwardly in intimate contact with a bottom portion of the tow bar 12 when assembled. A second end or extension 34 of the spring 14 extends radially outwardly from the other end of the torsion spring 14 in intimate contact with a bottom portion of the steering arm 16 when assembled. When assembled, the spring 14 is disposed between the side rails 18 of the tow bar 12 , allowing use of the original hitch pin 28 and not requiring use of a new, longer pin.
[0013] Additionally, the first end 32 of the spring 14 and the second end 34 of the spring 14 facilitate the use of the original tow bar 12 and the steering arm 16 , without the use of additional parts or hardware. It is understood that other spring types could be used without departing from the scope and spirit of the invention.
[0014] The steering arm 16 includes a pair of spaced apart longitudinally extending side rails 36 . A first end 38 of each of the side rails 36 has a laterally extending aperture 40 formed therein. A web 42 extends between the pair of side rails 36 to form an inverted unshaped channel. The apertures 40 of the side rails 36 of the steering arm 16 are aligned to receive the hitch pin 28 therein. The other end of the steering arm 16 is adapted to be connected to a trailer or towed vehicle (not shown). The cross sectional shapes of the tow bar 12 and the steering arm 16 are not critical to the invention and other cross sectional shapes and configurations such as square tubing, for example, may be used for the tow bar 12 and the steering arm 16 without departing from the scope and spirit of the invention.
[0015] To assemble the tow bar and steering arm assembly 10 , the tow bar 12 and the steering arm 16 are axially aligned in a substantially horizontal position. The apertures 22 of the side rails 18 of the tow bar 12 are aligned with the apertures 40 of the side rails 36 of the steering arm 16 . The hitch pin 28 is inserted through one set of the aligned apertures 22 , 40 as indicated by the arrow in FIG. 2 .
[0016] An insertion assist pin 44 is inserted through the other set of aligned apertures 22 , 40 as indicated by the arrow in FIG. 2 to maintain the desired alignment of the tow bar 12 and the steering arm 16 . The tow bar 12 is pivoted about the hitch pin 28 and the assist pin 44 to a substantially vertical position. The interior 30 of the torsion spring 14 is aligned with the apertures 40 of the side rails 36 of the steering arm 16 . The hitch pin 28 is then caused to slide through the interior 30 of the torsion spring 14 , into contact with the assist pin 44 . The assist pin 44 is caused to slide out of the set of apertures 22 , 40 , and is replaced therein by the hitch pin 28 . The hitch pin 28 is then secured in place with fasteners or safety pins,(not shown), for example, to militate against axial movement of the hitch pin 28 . The tow bar 12 is then lowered to a substantially horizontal position for operation, thereby loading the torsion spring 14 . Thus, the tow bar 12 is urged in an upward direction or towards a vertical position by the torsion spring 14 . It will be appreciated that the spring 14 is effective to maintain the tow bar 12 and the steering arm 16 in a substantially axially aligned horizontal position. Any downward loading of one or the other of the pivotally interconnected members will tend to wind the spring 14 and militate against any relative downward pivotal movement.
[0017] To disassemble the tow bar and steering arm assembly 10 , the tow bar 12 is raised to the substantially vertical position. The fasteners or the safety pins are removed from the hitch pin 28 . The assist pin 44 is placed into contact with the hitch pin 28 causing the hitch pin 28 to slide out of the one set of apertures 22 , 40 . The hitch pin 28 is then caused to slide out of the interior 30 of the torsion spring 14 , thus freeing the torsion spring 14 . Further disassembly by removal of the hitch pin 28 or replacement of the torsion spring 14 can be accomplished as desired.
[0018] In use, once the tow bar and steering arm assembly 10 is assembled, the tow bar 12 is pivotable about the hitch pin 28 . When the trailer or towed vehicle is not being towed, the tow bar 12 can be positioned vertically. When the operator lifts the tow bar 12 to the vertical position, the torsion spring 14 urges the tow bar 12 upward, thus assisting the operator in lifting the tow bar 12 . When it is desired to tow the trailer or towed vehicle, the tow bar 12 is lowered to the substantially horizontal position, and held in this position while being coupled to the towing vehicle. The torsion spring 14 urges the tow bar 12 upward during the coupling operation, thus reducing the lifting forces required and assisting the operator in holding the tow bar 12 in the desired position.
[0019] From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.
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A tow bar with a torsion spring disposed between the tow bar and a steering arm to urge the tow bar towards an operating position, the torsion spring minimizing the force required by an operator to lift the tow bar.
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BACKGROUND OF THE INVENTION
This invention relates to devices for digging and cutting in the ground, and more particularly to a trailer assembly for preparing and refurbishing trenches that are used to improve irrigation in citrus groves and other agricultural landscapes.
Many different devices have been used to dig trenches for agriculture irrigation, examples of which are disclosed in U.S. Pat. Nos. 4,535,555 and 4,887,372. These devices include rotating cutting blades connected to a frame that is pulled behind a tractor. The cutting blade when pulled is rotated about an axis perpendicular to the wall of the trench to dig new trenches and repair existing trenches.
The trees and shrubs for citrus groves are typically located in rows. Trenches are then dug between the rows to provide proper drainage for the soil. However, in some groves trees are placed further apart than other groves. Thus the width of the trench must be changed to accommodate the tree placement. A drawback to the prior trenching devices is that they do not provide adjustments for changing the trench width.
In closely spaced groves, conventional trenching devices discharge debris and earth in large particles and in a random direction. Many of the prior trenching devices cannot redirect this discharge resulting in damage to the leaves on the trees.
SUMMARY OF THE INVENTION
It is an object of this invention to provide an improved apparatus for digging and repairing trenches.
It is another object of this invention to prepare trenches with a left and right rotating cutting blade with a position that can be remotely moved to change the width and volume of the trench.
It is a further object of this invention to place a remotely adjustable cover over the discharge of a trencher's cutting blade to redirect the discharge to prevent crop damage when preparing trenches.
An additional object of this invention is to dig trenches with a blade that breaks down the earth being dug into small particles to prevent large particle from damaging the foliage.
These and other objects are provided with an apparatus for preparing trenches comprising an elongated frame, a left and right support pivotally carried by the frame and a left and right rotatable cutter respectively connected to a left and right shaft. An axis of rotation extends through the shafts which is inclined with respect to horizontal. A left motor is connected to the left support and the left shaft. The left shaft extends from the left motor through the left support to connect to the left cutter. A right motor connected to the right support and the right shaft. The right shaft extends from the right motor through the left support to connect to the left cutter. The motors are operative to rotate the cutters about the axis. A device is connected between the support and the frame that pivots the support to change the angle of inclination of the cutter. Preferably, a device is connected between the support and the frame for remotely varying the distance between the left and right support to change the width of the trench.
In another aspect of the invention, an apparatus for preparing trenches in by removing earth in the ground is provided. The apparatus comprises an elongated frame, and a left and right support pivotally carried by the frame. A left and right rotatable cutter having a plurality of blades is used to cut the trenches. Each cutter has an axis of rotation which is inclined with respect to horizontal. The plurality of blades extend radially outward from the axis of rotation. At least one motor operative is connected to the other to rotate the blades about the axis to cut a trench out of the ground. A cover is pivotally connected to each support at a preselected orientation and radially aligned with the blades. The cover's orientation is selected to direct the angle of earth being projected over the side of the trench when the cutter rotates to prepare the trench. A hydraulic cylinder in combination with a controller is included for remotely varying the orientation of the cover on the support to change the angle the earth being projected.
BRIEF DESCRIPTION OF THE DRAWINGS
Further features and advantages of the invention will be apparent from the following description which is given solely by way of example with reference to the accompanying drawings, in which:
FIG. 1 is a right side perspective view of the apparatus for preparing trenches according to the invention;
FIG. 2 is a front side perspective view of the apparatus shown in FIG. 1 with the cutter supports in a separated position;
FIG. 3 is a partially sectioned top view of the apparatus along 3--3 of FIG. 1;
FIG. 4 is a partially cutaway perspective view of the apparatus illustrating the movement of the supports;
FIG. 5 is a rear partially sectioned view of the apparatus shown in FIG. 1;
FIG. 6 is a front side perspective view of the apparatus shown in FIG. 1;
FIG. 7 is a bottom right side partially sectioned view shown in FIG. 1 illustrating the cutter blades and support;
FIG. 9 is a section view of the cutter in FIG. 7 along line 8--8; and
FIG. 9 is a simplified schematic diagram of a device for controlling the apparatus for preparing trenches.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, there is shown the apparatus for preparing trenches generally referred to as trencher 10, having a frame 12 connected to support 14 (L and R) on a respective left and right side of trencher 10. Frame 12 includes a longitudinal bar 16 integrally connected at its rearward end to vertical rear frame 18 and connected at its forward end to vertical fame 20.
Referring to FIG. 1 and 6 vertical frame 20 is pivotally attached at its lower end tow bar 22 which is connected with pin 24 to a tow arm of a tractor. Referring to FIGS. 1-4, vertical frame 20 of trencher 10 is connected through a link assembly 15 which includes brs 26 (R and L) rectangular branch 62 (R and L), and bars 28 (R and L) to support 14 (R and L). Frame 20 is connected through bars 26R, branch 62R and bar 28R. Supports 14 (L and R) are disposed symmetrically on the left and right sides of trencher 10 and hold motor 30 (R and L) and cutter 32 (R and L) respectively.
Referring to FIGS. 1, 2 and 5, disposed at the rear end of trencher 10 and pivotally interlocked with the lower portion of frame 18 is fork 36. Hydraulic jack 38 is connected at one end to bar 18 and at its other end to fork 36. Jack 38 expands and contracts piston 39 to pivot fork on frame 18 to raise and lower supports 14 and cutter 32 into the ground during operation. Disposed at opposite ends of fork 36 are wheels 40 and 42 which are laterally spaced in a line longitudinally with tractor wheels (not shown). Conventionally, trencher 10 is pulled by a tractor to prepare, refurbish or excavate a trench. However, the invention is not limited to being pulled and trencher 10 may be adapted to be pushed in a forward direction as well.
The left side of link assembly 15 and frame 20 are identical and are symmetrical about the longitudinal axis of tractor 10. Thus only the right side will hereafter be described.
Referring to FIGS. 1-4, bars 26 are connected at one end with pin 44 to vertical frame 20. Bars 26 are pivotally connected at their other end to the outer portion of branch 62 with pin 45. An inner portion of branch 62 pivotally engages with wing bars 28 using pin 47. Bars 28 are pivotally connected at one end with pivot 45 to vertical frame 20. Attached to the mid-portion of the upper surface of the top parallel bar 28 is bar 48 which extends laterally outward from bar 26. A cylindrical coupling 49 integrally connects at its lower end to bar 48 and extends vertically upward therefrom. Horizontal strut 51 is attached at one end with pin 55 to coupling 49 and is attached at its other end with pin 52 to piston 65 of jack 54. Center pin 52 has a collar 55 that slides laterally along track 53 attached to a bottom surface of bar 16.
The rearward end of jack 54 is connected to the rear portion of bar 16 with coupling 57. Jack 54 is fed hydraulic fluid from control panel 110 (FIG. 9) which by conventional mean expands piston 71 outward to push pin 52 forward thereby forcing bars 28 (L and R) to pivot outward. In FIG. 3 there is shown in phantom the position of assembly 15 when piston 71 expands to its extended position.
Referring to FIG. 4, there is shown a blade 59 which is optionally attached with adjustable bracket 61, that changes the height of blade 59, to a plate 63, engaging the mid-portion of frame 20. Blade 59 extends with bar 65 below frame 20 and has flat left and right blades 67 and 69 which plows through the center of a trench being refurbished when blade 59 is used.
Support 14 is pivotally attached along its side to branch 62 with pin 63 extending through support 14. Vertically oriented jack 74 is connected at its top end to branch 62 and connected at its bottom end to a top surface of frame 70 of support 14. Jack 74 includes a piston 77 which expands and contracts to vary the angle of support 14 and cutter 32 with respect to horizontal. Support 14 includes a rearward deflection portion 66 which has a vertical plated to prevent cutter 32 discharging debris behind trencher 10.
Support 14R and cutter 32R are placed on the right side of trencher 10, and cutter 32L and support 14R are positioned symmetrical about an axis of symmetry of trencher 10. Support 14 holds a motor 30 in housing 68.
Referring to FIGS. 7 and 8, a shaft 76 extends downward from motor 30 and is attached on the bottom side of frame 70 to blades 90 and 92. Referring to FIGS. 2-8, shield 80 is pivotally connected to lateral edge of frame 70 with elongated pin 81. The angle of shield 80 is controlled by expanding and contracting piston 83 of jack 82. It is recognized by changing the angle of shield 80 with respect to top surface of plate 70, the angle at which earth is projected out of trencher 10 during operation, is directed and controlled.
Hydraulic motor 30 is constructed using conventional techniques and is powered with fluid originating from hydraulic supply 86. Referring to FIGS. 7 and 8, motor 30 rotates elongated shaft 76 about a longitudinal axis 111. Shaft 76 extends through an aperture 71 in support 14. Each left and right hydraulic motor 30 independently controls the rotation of it3 s own respective blades 90 (L and R) and 92 (L and R) to increase precision during the trenching operation.
Referring to FIG. 6, disposed behind vertical frame 20 is a tow bar 22 pivotally connected to vertical frame 20. A jack 89 is oriented at an approximately 45° angle between vertical frame 20 and tow bar 22. Jack 89 is connected to the mid-portion of support 20 above tow bar 22, and extends to the mid-portion at tow bar 22. Piston 91 extends inward and outward from jack 89 to pivot tow bar 22 about frame 20. Pivoting tow bar 22 frame 20, raises and lowers frame 20 to change the angle of attack of cutters 32.
Referring to FIGS. 7 and 8, cutter 32 is shown having a first level of blades 90 and a second level of blades 92. Blades 90 and 92 rotate about axis 111 to excavate the ground and refurbish trenches. It has bee recognized by the inventor that when more than four blades are used and preferably at least 20 blades are used, smaller particles are dispersed when trench is refurbished thereby reducing damage to foliage. These blades 90 and 92 extend radially outward with struts 93 from shaft 76. Disposed at the end of shaft 76 is annular disk 94 which rotates in a horizontal plane normal to axis 111 of shaft 76.
Each of blades 90 and 92 have a flat lower surface 96 and 98 respectively. Further the front surface 104 and 108 is also flat. Disk 94 also has a flat front surface 102 in the vertical plane. Preferably the lower surface 98 are at a lower level than the upper surface 100. Blades 90 and 92 alternate between the first level and the second level while extending outward from shaft 76. Extending through shaft 76 is an axis 111 by which blades 90 and 92 rotates.
Referring to FIG. 9, there is shown a panel 110 that is preferably mounted in the cabin of a tractor that pulls trencher 10. On panel 110 are switches 112-124 which respectively control jacks 54, 82 (R and L), 74 (L and R), 89, and 38. Switches 112-124 operate by being pulled or pushed to inject hydraulic fluid into their respective jacks by conventional means. Each one of these jacks are operated individually and may be used to change angles of cutters 32 as well as the angle of attack of trencher 10. Moving switch 112 changes the position of pin 52 to vary the span between support 14 and cutters 32 (L and R).
It is recognized by the inventor that by placing pin 52 within a track 53 in bar, and using jack 54 to move pin 52 laterally, support 14 and cutter 32 on the left side and the right side of trencher 10 move inward and outward while maintaining the same distance from the axis of symmetry of trencher 10. This distance between the cutters 32 is critical to maintain the walls of the trench at identical distances from the center point of the trench when preparing a trench with walls of uniform construction. It is also recognized by the inventor that by using the various controls and hydraulics described, any angle of attack and dispersal of debris can be provided.
This concludes the description of the preferred embodiments. A reading by those skilled in the art will bring to mind various changes without departing from the spirit and scope of the invention. It is intended, however, that the invention only be limited by the following appended claims.
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An apparatus for preparing and refurbishing trenches having two cutters supported on a frame. During operation of the apparatus, the cutters rotate about an axis to prepare the trench. The distance between the cutters as well as the angle of the cutters are adjustable to change the size and shape of the trench. A cover is placed over the cutters and has a remotely adjustable orientation which can be varied to select the direction of earth being projected over the side of the trench during operation. The cutters are preferably powered by dedicated motors, and include a multiplicity of blades mounted on dual levels to increase efficiency of cutting the trench.
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INTRODUCTION
The present invention relates generally to an unobtrusive carrier having quick-release access and more particularly to a compartmentalized bag of conventional appearance having holster means discretely defined therein and a quick opening spring-biased compartment defined thereabout to provide the user thereof with quick and ready access to a protective device, such as a pistol, a mace can, a pepper spray or the like secured therein and shrouded thereby to enable the user to defend him or herself from marauders, rapists, robbers and other hostile approaches to his or her person, particularly when the user travels alone.
BACKGROUND OF THE INVENTION
The need for self protection, particularly for young adult females, has never been greater. Moreover, such protection is not limited to the female population because not a day passes without one or more headlines screaming of the murder, rape or robbery of another defenseless victim. Even more shocking is the fact that such incidents are not limited to remote areas but are occurring "down town" and in many posh suburban shopping centers.
Historically, self-defense devices have been worn on the person. Depending upon the period, swords, knives, or firearms have been in vogue. However, all such devices required a carrying means of some sort and most of the improvements thereof were intended to allow quick and ready access. Today, although a person desiring to carry an instrument of self-defense often still requires a visible carrying means so as not to run afoul of many gun control laws, there are States which allow the carrying of a concealed weapon so long as one complies with the proper permit requirements. Legality notwithstanding, there are significant problems of structurally providing thorough concealment while also making the self-protection device quickly and readily accessible for immediate use.
The prior art has attempted to deal with some of these and other desiderata with varying degrees of success. For instance, Bianchi (I) (U.S. Pat. No. 3,630,420) describes a quick access, open front holster including an inner liner and an outer facing which encase the barrel and the cylinder portions of a revolver. The front slot is held in a generally closed position by a "U" shaped spring which extends around the perimeter of the front opening of the holster. The spring bias maintains a firm pressure at the front periphery of the holster to secure the gun therewithin. The front opening is further provided with a snap secured strap which ensures that the pistol cannot be dislodged or otherwise unintentionally fall from the holster. In use, the wearer may easily draw the gun by grasping the exposed handle, using an index finger to open the safety strap fastener, and removing the revolver forwardly out of the holster.
Jones (U.S. Pat. No. 3,904,091) teaches a sidearm holster having a latchable flap or strap composed of a spring metal strip having one end anchored in the rear portion of the holster. The flap crosses over the pistol between the hammer and the handle and connects into a latching mechanism on the outside of the holster. A spring loaded latch holds the free end of the strap in place, thereby securing the gun in the holster.
In use, the wearer pushes a button at the bottom of the holster which releases the spring loaded latch from a specially configured spring steel strip. The strip springs away from the top of the gun and allows the wearer to draw the gun from the holster.
Bianchi et al. (II) (U.S. Pat. No. 4,101,060) also teach a front opening holster in which the front opening is maintained in a "closed" position by the bias of a pair of inverted "U" shaped spring members which extend from the closed rear edge of the holster, over the weapon and downward to the lower end of the front of the holster. The spring members are sewn between the shell and liner of the holster, are mechanically coupled at their innermost ends and are free at the front opening so that the entire front opening exhibits a substantially uniform resistance to opening. Closure straps are formed integrally with the holster body and overlie the hammer region of the handgun. The closure straps include recessed directional snaps which allow opening only upon the forward movement of the user's hand.
When the user desires to draw the weapon, he grips the handle of the gun and with his thumb releases the snap. The spring biased front of the holster provides a uniform resistance which decreases muzzle drag on the gun and allows the wearer to draw the gun smoothly and rapidly in a single motion.
Shoemaker (U.S. Pat. No. 4,580,707) teaches a spring release adjustable shoulder holster for wear beneath an outer jacket. The gun lies vertically within the holster with the butt facing forward and, as with other shoulder holsters, is to be drawn cross-body of the wearer. The rear of the holster is spring biased in a manner similar to Bianchi. The spring members are formed as a "W" shape from a single piece of wire which is mounted from the center point of the wire to the front of the holster. The portions of the wire are over-biased to create a generally uniform resistance to the rear opening.
When the wearer wishes to draw the pistol, he grips the handle of the pistol and withdraws it across his body against the biased force of the closure springs.
DeSantis et al. (I) (U.S. Pat. No. 4,966,320) and DeSantis et al. (II) (U.S. Pat. No. 5,170,919) each teach a handgun holster which is completely concealed by an ordinary carrying pouch. The holster is attached to a back portion mounted on the wearer while a front portion comprising the ordinary carrying pouch is integrally yet only partially attached to the back portion. The top and at least one side of the front portion fold over and are attached by Velcro® to the back portion to enclose the holster in an inner area for storing the handgun. An attached belt allows the wearer to wear the pouch around his/her waist. The outward facing portion of the pouch may have actual zippered pockets for carrying ammunition or other articles, or the pockets may be only simulated.
Should the wearer have need to draw the weapon, he or she need only grip the flap of the pouch and pull which releases the Velcro® strips and allows the flap to be torn away from the back portion and expose the holster and gun, thereby providing easy and rapid access to the weapon.
However, in spite of previous attempts to provide an ideal unobtrusive weapon carrier for protection of oneself against the social predators that run rampant on our streets, none accomplished completely the portability and smooth operation necessary to achieve quick and reliable access to a stored weapon without alerting the predator that the designated victim is capable of self-defense. It is toward this goal that the present invention is directed.
BRIEF SUMMARY OF THE INVENTION
The present invention relates generally to an unobtrusive carrier having quick-release access for protective devices contained or holstered therein and more particularly to a shoulder carried attache, briefcase or purse-like structure having a spring biased compartment accessible through an opening in one edge of the carrier in which self-protective devices such as a pepper spray, a mace dispenser or a handgun can be unobtrusively stored. Thus, the carrier provides quick and easy access to the self-protective device should the sudden need for its use arise. Furthermore, the carrier device is constructed so that, when worn over the shoulder with a strap, the closed compartment is disposed in the body portion of the device separate from and independent of one or more main storage areas and is accessed quickly by one hand releasing the locking means to activate a spring-biased frame assembly which pops open the front of the compartment and allows ready access to the self-protective device mounted therewithin.
Accordingly, it is a prime object of the present invention to provide an unobtrusive, conventionally appearing means for transporting a defensive weapon in such a manner that it is not readily visible and yet remains quickly and easily retrievable when needed for the self-protection of the bearer from an unwanted assault.
A still further object of the present invention is to provide a novel and unique attache/ or purse-like structure which contains therewithin a discrete spring-biased compartment for storing, and a single handed actuator for opening to allow ready retrieval of a defensive weapon mounted therein.
These and still further objects as shall hereinafter appear are readily fulfilled by the present invention in a remarkably unexpected manner as will be readily discerned from the following detailed description of an exemplary embodiment thereof especially when read in conjunction with the accompanying drawings in which like parts bear like numerals throughout the several views.
BRIEF DESCRIPTION OF THE DRAWINGS
In the drawings:
FIG. 1 is an isometric view of an unobtrusive carrier embodying the present invention in its open position;
FIG. 2 is an isometric view of the latch-frame assembly which is an integral part of the carrier of FIG. 1 in its closed position;
FIG. 3 is a cross-sectional view of the latch-frame assembly of FIG. 2 taken on line 3--3;
FIG. 3A is another cross-sectional view of the latch-frame assembly as shown in FIG. 3 when it is moved to its open position;
FIG. 4 is a fragmented cross-sectional view of the latch-frame assembly of FIG. 2 taken on line 4--4;
FIG. 5 is a fragmented isometric view of an alternative latch-frame assembly shown in its closed position;
FIG. 6 is an isometric view of a holster for use in the unobtrusive carrier of FIG. 1; and
FIG. 7 is an isometric view of an alternative holster for use in the unobtrusive carrier of FIG. 1.
DESCRIPTION OF PREFERRED EMBODIMENT
The present invention relates generally to an unobtrusive carrier for self-protection devices which provides quick access to such a device in case of emergency. The carrier is identified in the drawings by the general reference 10.
As shown in FIG. 1, carrier 10 comprises a body portion 11 having a first side panel 12, a second side panel 13, a trailing end panel 14, a leading end panel 15, a bottom panel 16 and an upper panel 17. Upper panel 17 comprises a first strip 18, a second strip 19, and a third strip 20 which are defined by the placement of suitable closure means such as first zipper 21 and second zipper 22 therein in spaced generally parallel relationship to each other. The several panels are further sewn together or otherwise attached as will be explained below.
At the intersection of trailing end panel 14 and upper panel 17, suitable means such as one or more loops 24 are attached to receive and secure a ring 25 through which is threaded first end 26 of a suitable shoulder strap 27. Shoulder strap 27 also has a second end 28 which is threaded through a similar assembly attached at the intersection of leading end panel 15 with upper panel 17. One or more loops 30 are attached hereto and ring 31 is similarly secured in loops 30 to receive second end 28 of shoulder strap 27.
As shown in FIG. 1, carrier 10 comprises a body portion 11 including one or more principal storage compartments (not directly shown) which are accessible by one or more suitable closure means such as zippers 21, 22. As is conventionally known, zippers 21 and 22 are operative to open and shut carrier 10 for the storage of and access to the usual worldly things normally carried in the principal storage compartments of one's purse or attache/ case. Of course, alternative embodiments could foreseeably make use of, for example, one zipper opening into a plurality of compartments or a plurality of zippers opening into single, respective compartments. Be that as it may, it is preferable that at least two compartments be formed, one each on opposite sides of and concealing a special storage chamber 35 which is described below.
Leading edge panel 15 is formed by the mating of two sections, namely, a first strip 33 and a second strip 34 each of which are secured as by sewing to an adjacent side panel 12 or 13, respectively, and are separable in a manner to be hereinafter described to expose a special, secret storage chamber 35.
As is further shown in FIG. 1, special storage chamber 35 is defined by and between a first interior panel 37 and a second interior panel 38. Each interior panel is respectively attached as by sewing one end thereof to its corresponding strip 33, 34 of leading end panel 15 and by sewing the other end of each to the interior of trailing end panel 14 of body portion 11. Panels 38 are also sewn or otherwise attached to upper panel 17 at their upper edges as shown at common seam 39. Seam 39 is shown in FIG. 1 where it bisects strip 19 of upper panel 17 for more than half of the length of carrier 10. The lower edges of panels 37, 38 are likewise sewn or otherwise secured to bottom panel 16 for an even longer portion of the length of carrier 10. However, to complete chamber 35 which can be accessed only through leading end panel 15, short portions of panels 37 and 38 are not connected in common to the upper and bottom panels but are separate and connected only to respective portions of upper panel 17, leading end panel 15 and bottom panel 16. The connection of the upper edge of panel 37 to panel 17 is at a seam shown for example at or near area 40 in FIG. 1. Likewise, a seam at 41 shows the connection of panel 38 to panel 17. The lower edge panel connections are similarly attached as shown for example at a seam at or near area 43 where panel 38 is connected to bottom panel 16. Latch frame assembly 44 is sewn into these connection seams in any conventional manner so long as it is generally positioned as shown in FIG. 1.
Referring now to FIGS. 2, 3 and 4, latch-frame assembly 44 is shown in detail apart from carrier 10. Assembly 44 has two principal frame members, a first member 45 and a second member 46. Members 45 and 46 are pivotally attached to each other at their respective upper ends 47 and 48 by pivotal connector 49. Similarly, members 45 and 46 are connected at their respective lower ends 50 and 51 by a pivotal connector 52.
A coiled spring 53 is further attached to assembly 44 to bias assembly 44 in its open position as shown in FIG. 1. In the preferred embodiment as shown in FIGS. 2 and 4, the coiled portion of spring 53 is wrapped around a downwardly extending portion of pivotal connector 49 at the connection point of upper ends 47, 48 of frame members 45, 46. Spring 53 also has two elongated arm portions 56 and 57 which extend outwardly from coil 53 and are respectively engaged one each with each of the inner surfaces of first and second frame members 45 and 46.
In a preferred practice of the present invention, latch-frame assembly 44 includes latch mechanism 58 which is shown in FIGS. 2 and 3. Mechanism 58 is pivotally attached to one of the two frame members 45, 46 by snap fitting the open part of the semi-cylindrical connection portion 59 about frame member 45, for example, in the position shown in FIG. 3. Assembly 44 may then be closed by detachably fixing semi-cylindrical catch portion 60 on the other frame member 46. Assembly 44 may then be opened as shown in FIG. 3A, by applying a certain minimal amount of upward manual pressure on lift portion 61 which frees catch portion 60 from member 46, thus allowing spring 53 to assume its pre-biased, open position such that arm portions 56 and 57 force open frame members 45 and 46 as shown in FIGS. 1 and 3A. Ready access to a self-protection device contained within compartment 35 is thus quickly obtained.
Referring now to FIG. 5, an alternative latch-frame assembly 144 is shown comprising a first frame member 145 and a second frame member 146 pivotally connected at their upper and lower ends by pivotal connectors (not shown) and a coiled spring member such as is described above to secure members 145 and 146 of alternative frame assembly 144 in pivotal abutting relationship to each other.
A cylindrical shaft 147 is slidably connected to assembly 144 to operably latch frame members 145 and 146 in closed position or unlatch them so they can assume an open position. Shaft 147 is slidably operable within top connection member 148 which is fixedly attached to frame member 146 at connection 149. An open cylinder 150 in connection member 148 allows free motion of shaft 147 in generally parallel relationship to frame members 145 and 146.
A similar, lower connection member 152 is fixedly attached to frame member 145 at connection 153 and allows for the slidable insertion of shaft 147 into hollow cylinder 154. Manual movement of shaft 147 upward by gripping handle 156 and pulling upwardly causes tip 157 to withdraw from cylinder 154. This withdrawal of tip 157 from cylinder 154 frees the coiled spring as described above (and shown in FIG. 4) from all restraint and enables frame members 145 and 146 to assume their pre-biased open position. Frame assembly 144 is thereby opened to the position shown in FIG. 1, and thus provides ready access to storage compartment 35.
A cylindrical compression spring 160 is circumscribed about shaft 147 and secured in place by a detent means 162 affixed to shaft 147 in spaced relationship to shaft tip 157. Spring 160 is operative to bear against detent means 162 to force downward or bias tip 157 in and through cylinder 154 and lock frame assembly 144 in its closed position. Further, however, detent means 162 is used to compress compression spring 160 against compression stop 164 when shaft 147 is moved upwardly. Stop 164 is fixedly attached to frame member 146 and allows shaft 147 to move slidably therethrough. Thus, spring 160 normally holds shaft 147 downward in closed position but when handle 156 is pulled upwardly with a force sufficient to offset the bias of compression spring 160, shaft 148 and detent 162 move upwardly and free tip 157 to open assembly 144.
In a preferred practice of the present invention, detachable pouch members or holsters 67 and 68 as shown in FIGS. 6 and 7 are configured to provide secure support for a small canister (such as a mace dispenser or a pepper spray) and/or a pistol or like defensive device which is insertable thereinto through an appropriate opening 69 defined therein. Holsters 67 and 68 are alternately and detachably attached to the inner surface of panels 37, 38 of carrier 10. Each of these panels have a vertically extending patch (not shown) formed of conventional hook-loop fastening fabric (VELCRO®) secured thereto approximately midway into compartment 35. Elongated strips 72, 73 of corresponding like fastening fabric are secured horizontally to the outer respective sides of holsters 67, 68 and coact with the hook-loop patches inside compartment 35 to attach holsters 67, 68 within compartment 35 at whatever position or angle may be required to support a particular defensive device within carrier 10.
From the foregoing, it is readily apparent that a new and useful embodiment of the present invention has been herein described and illustrated which fulfills all of the aforestated objects in a remarkably unexpected fashion. It is of course understood that such modifications, alterations and adaptations as may readily occur to the artisan confronted with this disclosure are intended within the spirit of this disclosure which is limited only by the scope of the claims appended hereto.
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An unobtrusive carrier for self-protective devices is disclosed. Such a carrier has a body portion to which is connected a carrying strap. The body portion has a special secret compartment which is solely accessible by a spring-biased opening at one end of the body portion. The spring-biased opening comprises a frame assembly having two frame members pivotally connected to each other such that they can alternately be held in closed position against the spring-biasing or snapped to open position by the spring arms when a catch is released. A holster is provided within the secret compartment.
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TECHNICAL FIELD
This disclosure relates to resource allocation in a radio access network.
BACKGROUND
High Data Rate (HDR) is an emerging mobile wireless access technology that enables personal broadband Internet services to be accessed anywhere, anytime (see P. Bender, et al., “CDMA/HDR: A Bandwidth-Efficient High-Speed Wireless Data Service for Nomadic Users”, IEEE Communications Magazine, July 2000, and 3GPP2, “Draft Baseline Text for 1xEV-DO,” Aug. 21, 2000). Developed by Qualcomm, HDR is an air interface optimized for Internet Protocol (IP) packet data services that can deliver a shared forward link transmission rate of up to 2.46 Mbit/s per sector using only (1×) 1.25 MHz of spectrum. Compatible with CDMA2000 radio access (TIA/EIA/IS-2001, “Interoperability Specification (IOS) for CDMA2000 Network Access Interfaces,” May 2000) and wireless IP network interfaces (TIA/EIA/TSB-115, “Wireless IP Architecture Based on IETF Protocols,” Jun. 6, 2000, and TIA/ELA/IS-835, “Wireless IP Network Standard,” 3rd Generation Partnership Project 2 (3GPP2), Version 1.0, Jul. 14, 2000), HDR networks can be built entirely on IP technologies, all the way from the mobile Access Terminal (AT) to the global Internet, thus taking advantage of the scalability, redundancy and low-cost of IP networks.
HDR has been adopted by Telecommunication Industry Association (TIA) as a new standard in the CDMA2000 family, an EVolution of the current 1xRTT standard for high-speed data-only (DO) services, commonly referred to as 1xEV-DO, Rev. 0 and standardized as TIA/EIA/IS-856, “CDMA2000 High Rate Packet Data Air Interface Specification,” 3GPP2 C.S0024-0, Version 4.0, Oct. 25, 2002, which is incorporated here by reference. Revision A to this specification has been published as TIA/EIA/IS-856, “CDMA2000 High Rate Packet Data Air Interface Specification,” 3GPP2 C.S0024-A, Version 1.0, March 2004, Ballot Resolution, but has yet not been adopted. Revision A is also incorporated here by reference.
A 1xEV-DO radio access network (RAN) includes access terminals in communication with radio nodes over airlinks. Each access terminal may be a laptop computer, a Personal Digital Assistant (PDA), a dual-mode voice/data handset, or another device, with built-in 1xEV-DO support. The radio nodes are connected to radio node controllers over a backhaul network that can be implemented using a shared IP or metropolitan Ethernet network which supports many-to-many connectivity between the radio nodes and the radio node controllers. The radio access network also includes a packet data serving node, which is a wireless edge router that connects the RAN to the Internet.
1xEV-DO, Rev. 0 radio access networks handle all connections with access terminals in an identical manner. Network resources are allocated to connections on a first-come-first-served basis. If there are insufficient network resources available when a connection request is received, the connection request is denied.
One feature that can be enabled by 1xEV-DO, Rev. A radio access networks is classification of connections into priority levels (e.g., high priority level or low priority level) based on quality of service (QoS) requirements. Network operators of QoS-enabled radio access networks can implement a tier pricing structure commensurate with different guaranteed levels of connection-based performance, such as bandwidth, call blocking rate, and call drop rate. Examples of ways in which a QoS-enabled radio access network can be used include priority level classification based on static information (e.g., a user subscription level or an access terminal type), dynamic information (e.g., a requested QoS service type), or both.
In one example of priority level classification based on static information, user profiles each indicating a subscription level (e.g., gold, silver, or bronze) of a user and/or a type of access terminal (e.g., Rev. 0 access terminal or Rev. A access terminal) that is associated with the user are communicated to the radio access network by the packet data serving node. When a connection request is received by the radio access network from an access terminal, the radio access network accesses the user profile associated with the access terminal making the connection request and classifies the connection as being a high or low priority level connection based on the user subscription level and/or access terminal type. For example, connections requested by Rev. 0 access terminals are classified as low priority level connections and connections requested by Rev. A access terminals are classified as high priority level connections. This form of priority level classification may result in low resource utilization if the resources allocated to the high priority level connections between the Rev. A access terminals and the radio access network are not fully utilized (e.g., the Rev. A access terminal is configured to support delay sensitive services but those services are not used during the lifetime of the connection), while connection attempts made by Rev. 0 access terminals are denied due to insufficient network resource availability.
In one example of priority level classification based on dynamic information, the radio access network supports premium services, such as delay sensitive services (e.g., a push-to-talk service or a Voice over IP service). In order to guarantee a certain level of performance to users of premium services (“premium users”), the radio access network needs to distinguish the premium users from users of best effort services (“regular users”). To do so, the radio access network relies on the signaling behavior of access terminals (e.g., in accordance with the Generic Attribute Update Protocol defined in the TIA/EIA/IS-856, Rev. A standard) to indicate whether a premium service is being activated. The signaling behavior of some access terminals negotiates and activates premium services during session configuration before setting up a connection. Other access terminals are configured such that the signaling behavior negotiates and activates premium services after the connection is established. In the latter case, the radio access network may be unable to identify an access terminal as being operated by a premium user during resource allocation and deny the connection attempt if there are insufficient network resources available. This may result in a failure to satisfy a service availability guarantee to premium users.
SUMMARY
In one aspect, the invention features a method that enables a radio access network to provide a service availability guarantee to a user of a premium service without requiring the radio access network to identify a priority level of a connection with an access terminal associated with the premium service user prior to connection establishment.
Implementations of the invention may include one or more of the following. The method may include establishing a session for the access terminal on the radio access network; and identifying the priority level of the connection based on session information. The session may be established prior to or after connection establishment. The session information may include an activated service identifier, such as a premium service identifier or a regular service identifier. The priority level of the connection may be identified as one of at least two priority levels, such as a low priority level or a high priority level.
The method may include allocating a resource of the radio access network to the connection based on the priority level of the connection. The method may include establishing a connection with the access terminal; and maintaining the connection for a period of time while the priority level of the connection is identified. The method may include determining whether a resource of the radio access network is to be allocated to the connection based on the priority level identification. The method may include determining whether a resource of the radio access network is available for allocation to the connection based on the priority level identification. The method may include terminating the connection if the priority level of the connection cannot be identified within the period of time. The method may include terminating a first connection in order to reclaim an allocated resource of the radio access network for subsequent allocation to a second connection, the second connection having a relatively higher priority level than the first connection.
In another aspect, the invention features a method in which, in a radio access network having N resources of which M are reserved for new connection establishment, providing a service availability guarantee that enables the radio access network to allocate at least K resources to connections associated with users of premium services, and allocate up to N-M resources to connections associated with users of regular services.
In other aspects, corresponding computer programs and apparatus are also provided.
Advantages that may be exhibited by particular implementations of the invention include one or more of the following. Network operators can accurately identify a premium user without having to rely on specific signaling behaviors of the premium user's access terminal. Once identified, the connection established between the premium user's access terminal is classified as a high priority level connection and resources are allocated such that a desired and/or required level of connection-based performance is guaranteed. The numbers of high and low priority level connections established at any given time can be easily adapted to optimize resource utilization, while ensuring that high priority level connections are provided with sufficient network resources so as to meet or exceed service availability guarantees.
Descriptions of one or more examples are set forth in the description below. Other features, aspects, and advantages will become apparent from the description and the claims.
DESCRIPTION OF DRAWINGS
FIG. 1 is a block diagram of a radio access network.
FIG. 2 shows cells of a radio access network.
FIG. 3 shows available connection resources of a sector.
FIG. 4 is a flowchart of a resource allocation process.
FIGS. 5 a and 5 b show resource allocation over a time period.
DETAILED DESCRIPTION
FIG. 1 shows a 1xEV-DO, Rev. A radio access network 100 with a radio node controller 102 connected to two radio nodes 104 a , 104 b over a packet network 106 . The packet network 106 can be implemented as an IP-based network that supports many-to-many connectivity between the radio nodes 104 a , 104 b and the radio node controller 102 . The radio node controller 102 is connected to the Internet 110 via a packet data serving node 108 . Other radio nodes, radio node controllers, and packet networks (not shown in FIG. 1 ) can be included in the radio access network 100 .
Network resources are allocated to access terminals 112 a - 112 f in order to enable the access terminals 112 a - 112 f to communicate with the radio access network 100 . Although there are several different types of network resources that are needed to establish a connection between each access terminal and the radio access network 100 , the example techniques described below refer to a connection resource in a sector. The techniques are similarly applicable to the other types of network resources.
Referring also to FIG. 2 , each radio node 104 a , 104 b can support multiple sectors 121 , with each sector covering a certain cell area 123 around the radio node 104 a , 104 b . Each active access terminal 112 is in communication with a radio node, e.g., radio node 104 a , using an airlink 120 . The airlink 120 comprises a forward traffic channel (depicted in FIG. 2 by a solid-lined arrow), which carries data transmitted from the radio node 104 a to the access terminal 112 a , and a reverse traffic channel (depicted in FIG. 2 by a broken-lined arrow), which carries data transmitted from the access terminal 112 a to the radio node 104 a.
Whenever the access terminal 112 a sends a ConnectionRequest message over a reverse traffic channel along with a RouteUpdate message to initiate a new connection with the radio access network 100 , the messages are immediately forwarded from the receiving radio node, e.g., radio node 104 a , to its serving radio node controller, in this case, radio node controller 102 ( FIG. 1 ). The serving radio node controller 102 examines the RouteUpdate message to determine a likely set of sectors that may be included in an active set for the access terminal 112 a . Suppose the active set of sectors includes the sectors 121 that cover cell area A 123 . The serving radio node controller 102 communicates with the radio node 104 a where these sectors 121 reside to request connection resources. The radio node 104 a allocates the sufficient connection resources to establish the connection. The serving radio node controller 102 then accepts the connection request, and causes the radio node 104 a to send a TrafficChannel assignment essage over the forward traffic channel to the access terminal 112 a . The access terminal 112 a returns a ReverseTrafficChannel (RTC) indication on the reverse traffic channel. Once the radio node 104 a acquires the RTC indication, the radio node sends a ReverseTrafficChannelAcknowledge (RTCAck) message to the access terminal 112 a to indicate the acquisition of the RTC signal. The access terminal 112 a then responds with a TrafficChannelComplete message to indicate the completion of the connection set-up.
In this procedure, each radio node 104 a , 104 b controls its own connection resources, with respect to both hardware resources available on the radio node and management of interference across its sectors. As a result, admission control is split between the radio node 104 a , 104 b and its serving radio node controller 102 . Admission control involves determining, based on a number of factors, whether a new user is to be added to the network 100 given the new user's likely impact on the performance of existing users and network components. Examples of factors include the current resource usage by existing users, the resources requested by the new user, measurement of current network performance, and policies imposed by the network operator. Radio nodes 104 a , 104 b provide local admission control for the sectors they control while the serving radio node controller 102 provides a global admission control. The portions of each radio node 104 a , 104 b and its serving radio node controller 102 that perform the admission control function are collectively referred to in this description as an “admission control component” of the radio access network 100 .
An admission control component of the radio access network 100 can be implemented to provide service availability guarantees even if a priority level of a connection cannot be determined at the time the connection is established. Referring to FIG. 3 , suppose there are N CE connection resources available for a given sector and T buffer,max of the N CE connection resources are reserved for use by the admission control component as a staging area for new connections. Provision of a staging area enables access terminals to have a high connection set up success rate as the admission control component can allocate up to T buffer,max connection resources to new connections. The number of T buffer,max connection resources that are actually in use at any given time is represented by T buffer , that is, 0≦T buffer ≦T buffer,max . T buffer,max can be set or modified by the network operator to obtain a predetermined call blocking performance.
The network operator can establish a service availability guarantee for users of premium services (“premium users”) in that sector by reserving at least T premium of the N CE connection resources for allocation to high priority level connections. Yet, instead of limiting users of best effort services (“regular users”) to only the remaining N CE −T premium connection resources, the admission control component can be implemented to allocate up to N CE −T buffer connection resources.
FIG. 4 shows a resource allocation process 400 implemented by an admission control component of the radio access network 100 . When a connection request is received ( 402 ), the admission control component first determines ( 404 ) whether the number of free connection resources n freeCE among the N CE connection resources is at least a large as the number of new connections requested. In some examples, n freeCE =N CE −n reg −n premium −n trans , where n reg is the number of connection resources currently used by regular users, n premium is the number of connection resources currently used by premium users, and n trans is the number of connection resource currently allocated to transient connections (i.e., connections that the admission control component has not identified as a low or high priority level connection). If there are not enough free connection resources, the admission control component rejects ( 406 ) the connection request. Otherwise, the admission control component accepts ( 408 ) the connection request, establishes the connection, and increments n trans by 1. The connection remains in the staging area for a period of time (referred to as a “grace period”) while the admission control component performs ( 410 ) a priority level classification of the connection.
In some examples, the connection is established with an access terminal that performs premium service negotiation and activation before the connection is set up. The admission control component classifies ( 412 a ) the connection as being a high priority level connection.
In some examples, the connection is established with an access terminal that performs premium service negotiation and activation after the establishment of the connection. The admission control component first classifies the connection as having a low priority level. Upon indication of a completion of the premium service activation process, the admission control component may upgrade the connection to a high priority level classification ( 412 b ).
Once a connection is classified as a high priority level classification, the admission control component increments n premium by 1 and decrements n trans by 1. The admission control component then checks to see if the size of T buffer is to be changed with the addition of a new premium user. In some examples, the admission control component first determines ( 414 ) if n premium +T buffer <T premium . If the determination yields a positive result, then T buffer =T buffer,max ( 416 ). In other words, the number of premium users on the network 100 has not exceeded the service availability guarantee for premium users, so the admission control component maintains the size of the staging area at its maximum in order to keep the call blocking probability low. If, however, the determination yields a negative result, then the admission control component performs ( 418 ) a check as follows: if (n premium <T premium ) is true, then T buffer =min(T premium −n premium , T buffer,max ) ( 420 ), else T buffer =0 ( 422 ). In other words, the admission control component can adjust the size of the staging area as the number of premium users on the network 100 meets or exceeds the service availability guarantee for premium users. In the event T buffer =0, the staging area is removed and the admission control component accepts connection requests from access terminals on a first-come-first-serve basis as connection resources become available. The staging are is re-established only when n premium falls below T premium . Thus, the staging area grows and contracts dynamically as connection resources are used and reclaimed.
In some instances, it may be necessary for the admission control component to terminate one or more low priority level connections in order to maintain the staging area at T buffer,max or T buffer . In some examples, the admission control component determines ( 424 ) if low priority level connections are to be terminated using the following check: if (m>0) and (n freeCE <m), where m=max(T buffer −n trans , 0) and n freeCE =(N CE −n reg −n premium −n trans ), then terminate ( 426 ) (m−n freeCE ) low priority level connections, otherwise take no action ( 428 ). Reclaiming a connection resource from a low priority level connection enables the admission control component to maintain the size of the staging area at T buffer,max or T buffer , while allocating enough connection resources to the high priority level connections. Although the termination of low priority connections can result in a high call drop rate for the regular users, such cost can be justified if the network operators desires to guarantee low call blocking rate for high priority connections.
If the access terminal does not perform premium service negotiation and activation before the connection is set up or the premium service activation process fails to complete within the grace period, the access control component classifies ( 430 ) the connection as a low priority level connection by default. The admission control component then determines ( 432 ) whether (N CE −(n premium +n reg +1))>T buffer . A positive result ( 434 ) indicates that there are sufficient connection resources available for allocation to the low priority level connection, in which case the admission control component allocates the connection resource, increments n reg by 1 and decrements n trans by 1. Otherwise, the admission control component rejects ( 436 ) the connection request and decrements n trans by 1.
FIG. 5 a shows an example of resource allocation of a sector by an admission control component of a radio access network over a period of time. In the illustrated example, there are 22 available connection resources for a given sector, and the network operator has established a service availability guarantee for premium users in that sector that reserves at least 10 of the 22 connection resources for allocation to high priority level connections. Regular user may use up to 14 of the 22 connection resources.
Suppose at time t=0, 14 connection resources are used by regular users, 3 connection resources are used by premium users, and T buffer =5. In this example, T buffer is used as the staging area, although in other examples, the staging area may be outside of T buffer (as described below with reference to FIG. 5 b ).
At time t=1, two new connection requests are received. The admission control component determines that there are enough connection resources available for allocation to the new connections, and establishes the connections A and B using two of the available T buffer connection resources in the staging area. n trans =2.
At time t=2 (during the grace period), the admission control component classifies the connection A as a low priority level connection and checks if (N CE −(n premium +n reg +1))≧T buffer . The negative result indicates that counting the connection A towards nreg would result in the reduction of T buffer from 5 to 4. As this is an unacceptable outcome, the admission control component terminates the low priority level connection A, and decrements n trans by 1.
At time t=3 (during the grace period), the admission control component classifies the connection B as a high priority level connection, increments n premium by 1 and decrements n trans by 1. The admission control component then checks to see if the size of T buffer is to be changed with the addition of a new premium user. In some examples, the admission control component first determines if n premium +T buffer ≦T premium . In this example, n premium (4)+T buffer (5)<T premium (10), so T buffer =T buffer,max (5). The admission control component then determines if low priority level connections are to be terminated in order to maintain the staging area at T buffer =T buffer,max (5) using the following check: if (m>0) and (n freeCE <m), where m=max(T buffer (5)−n trans (0),0)=5 and n freeCE =(N CE (22)−n reg (14)−n premium (4)−n tans (0))=4, then terminate (m(5)−n freeCE (4))=1 low priority level connection.
FIG. 5 b shows an example of resource allocation of a sector by an admission control component of a radio access network over a period of time. In the illustrated example, there are 22 available connection resources for a given sector, and the network operator has established a service availability guarantee for premium users in that sector that reserves at least 10 of the 22 connection resources for allocation to high priority level connections. Regular user may use up to 14 of the 22 connection resources.
Suppose at time t=0, 4 connection resources are used by regular users, 3 connection resources are used by premium users, and T buffer =5.
At time t=1, three new connection requests are received. The admission control component determines that there are enough connection resources available for allocation to the new connections, and establishes the connections C, D, and E using three of the free connection resources that are outside of T buffer , that is, the staging area in this example is outside T buffer . n trans =3.
At time t=2 (during the grace period), the admission control component classifies all three connections C, D, and E as high priority level connections, increments n premium by 3 and decrements n trans by 3. The admission control component then checks to see if the size of T buffer is to be changed with the addition of the three new premium users. In some examples, the admission control component first determines if n premium +T buffer ≦T premium . In this example, since n premium (6)+T buffer (5)>T premium (10), the admission control component performs a check as follows: if (n premium <T premium ) is true, then T buffer =min(T premium −n premium , T buffer,max ). As n premium (6)<T premium (10), the admission control component adjusts T buffer to have a size of T buffer =min(T premium (10)−n premium (6), T buffer,max (5))=4. The admission control component then determines if low priority level connections are to be terminated in order to maintain the staging area at T buffer =4. To do so, the admission control component determines the values of m and n freeCE , where m=max(T buffer (4)−n trans (0),0)=4 and n freeCE =(N CE (22)−n reg (4)−n premium (6)−n trans (0))=12. Since m(4) is greater than 0 but n freeCE (12) is not less than m(4), no low priority level connections need to be terminated in order to maintain the staging area at T buffer =4.
By allowing the regular users to be allocated up to N CE −T buffer connection resources and constantly changing the mix of available high and low priority level connections, network operators can guarantee certain levels of performance to premium users in accordance with established service availability guarantees, while optimizing resource utilization.
Although the techniques described above employ the 1xEV-DO air interface standard, the techniques are also applicable to other CDMA and non-CDMA air interface technologies in which premium services are available for use.
The techniques described above can be implemented in digital electronic circuitry, or in computer hardware, firmware, software, or in combinations of them. The techniques can be implemented as a computer program product, i.e., a computer program tangibly embodied in an information carrier, e.g., in a machine-readable storage device or in a propagated signal, for execution by, or to control the operation of, data processing apparatus, e.g., a programmable processor, a computer, or multiple computers. A computer program can be written in any form of programming language, including compiled or interpreted languages, and it can be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program can be deployed to be executed on one computer or on multiple computers at one site or distributed across multiple sites and interconnected by a communication network.
Method steps of the techniques described herein can be performed by one or more programmable processors executing a computer program to perform functions of the invention by operating on input data and generating output. Method steps can also be performed by, and apparatus of the invention can be implemented as, special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). Modules can refer to portions of the computer program and/or the processor/special circuitry that implements that functionality.
Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read-only memory or a random access memory or both. The essential elements of a computer are a processor for executing instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto-optical disks, or optical disks. Information carriers suitable for embodying computer program instructions and data include all forms of non-volatile memory, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, e.g., internal hard disks or removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in special purpose logic circuitry. Other embodiments are within the scope of the following claims.
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In a radio access network, techniques for enabling the network to provide a service availability guarantee to a user of a premium service without requiring the network to identify a priority level of a connection with an access terminal associated with the premium service user prior to connection establishment.
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FIELD OF THE INVENTION
The present invention relates generally to a vehicle steering control system, and more particularly to a motor driver circuit for an electric steering control system.
BACKGROUND OF THE INVENTION
In the case of a so called “steer-by-wire” system for a motor vehicle, an electric motor actuator is provided for generating torque and applying the generated torque to a rack or linear steering member for steering of a vehicle. In the steer-by-wire system, there is no mechanical connection between the operators steering wheel and the motor actuator. The electric motor actuator generates the torque required to turn a vehicle's road wheels. However, in an electrical power assist steering system (referred to as EPAS), there is a mechanical connection between the steering wheel and the motor actuator wherein the motor actuator assists a driver's applied torque. A precise level of generated electrical current is essential to enable the motor actuator to produce an appropriate magnitude of torque for either a steer-by-wire or an electric power assist steering system. The magnitude and direction of torque generated by the motor actuator is a function of a number of variables including a steering wheel angle input, the vehicle's road wheel angle, and an electric motor actuator current signal which is generated by a motor driver circuit. Although generally not compensated for, the appropriate magnitude of applied torque is also affected by factors such as temperature fluctuations, component-to-component variations, wear of components, and other factors. In an effort to more precisely match motor current to the desired torque in view of the aforementioned variables, designers of steer-by-wire systems have introduced devices which measure the amount of electric current generated by the motor driver circuit and which compensate the measured current by a predetermined value or “offset”.
However, in the above-mentioned prior art steering systems, no compensation is provided for environmental factors such as temperature and other sources of errors in the applied current which can change over time. The accuracy of the current compensation is thus severely limited in these systems. The error in compensation causes an inappropriate amount of current to be applied to the motor actuator resulting in either too much or too little steering torque being applied. There is therefore a need for a steering system that will take into account environmental factors, and other variables including time dependent variables when compensating the current applied to a motor actuator for steer-by-wire and EPAS systems.
SUMMARY OF THE INVENTION
It is a general object of the present invention to provide an improved steering control system in which the above-mentioned problems are addressed. A more specific object of the present invention is to provide a steering. control system which continuously monitors a control signal and an electric current applied to the motor actuator so as to improve the quality of current compensation in a steer-by-wire or EPAS system.
In order to achieve the above mentioned objects, there is provided according to the present invention a steering control system for a vehicle having an electric motor actuator, a motor driver circuit for generating and applying an electric current from the motor driver circuit and generating a feedback current signal. The steering control system includes a steering wheel angle sensor for sensing a steering wheel angle and generating a steering wheel angle signal; a vehicle road wheel angle sensor for sensing a vehicle's road wheel angle and generating a vehicle road wheel angle signal; a controller for setting an offset current signal and for processing the feedback current signal. The steering wheel angle signal, and the road wheel angle signal are used to generate a control signal for the motor driver circuit. The controller compares the control signal to a predetermined threshold value and subtracts the offset current signal from the measured electric current which is applied to the motor actuator when the control signal is greater than the predetermined threshold value. The offset current signal is set equal to an initial offset value when the control signal is less than the predetermined threshold value.
According to the present invention, the controller receives the generated steering wheel angle signal, road wheel angle signal, and feedback current signal to generate the control signal. The control signal is applied to the motor driver circuit and the motor driver circuit generates an electric current which is applied to the motor actuator. The current sensor measures and generates the feedback current to the controller. The controller continuously monitors the control signal and electric current to determine an adequate amount of compensation for the steering control system. Thus, the compensation of the electric current is consistently updated to reflect changes in the steering system during operation.
These and other advantages, features and objects of the invention will become apparent from the drawings, detailed description and claims which follow.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic illustration of a steering control system for a vehicle according to the present invention;
FIG. 2 is a flowchart of a compensation method performed by the controller used in the system according to this invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to FIG. 1, a steering control system 10 for a vehicle according to the present invention includes a steering wheel 12 connected to an input shaft 14 . A pinion gear 17 has gear teeth which are meshingly engaged with gear teeth (not shown) on a linear steering member or rack 16 . The rack 16 is coupled to a vehicle's road wheels 18 through a steering linkage in a known manner. The pinion gear 17 together with the rack 16 forms a rack and pinion gear set. The rotation of the pinion gear 17 is translated into lateral movement of the rack 16 causing steering angle changes for road wheels 18 .
When the steering wheel 12 is turned, a steering wheel angle sensor 13 senses a steering wheel angle of the steering wheel 12 and generates a steering wheel angle signal 15 for a controller 26 . In the preferred embodiment, the steering wheel angle sensor 13 is an absolute steering wheel angle sensor, wherein the steering wheel angle signal 15 is an analog signal, meaning a signal is produced as the steering wheel 12 is turned which identifies the steering position of the steering wheel 12 . A second embodiment of the steering wheel angle sensor 13 is a relative steering wheel angle sensor wherein the steering angle signal 15 is a digital signal generated by an algorithm that estimates the change in steering wheel position in relation to a specified reference point. A road wheel angle sensor 22 is mechanically coupled to a motor actuator 20 and generates an output related to the turning angle of the road wheels 18 . In the preferred embodiment, the road wheel angle sensor 22 is either a digital or analog encoder. In the case of the digital encoder, the motor actuator 20 generates electrical pulses which are applied to the digital encoder. In the case of the analog encoder, the motor actuator 20 generates an analog signal which is applied to the analog encoder. Concurrently with the turning of the steering wheel 12 , the motor actuator 20 is energized and an output gear (not shown) of the motor actuator 20 begins to rotate. The angle and number of rotations of the motor actuator 20 corresponds directly with a turning angle of the road wheels 18 . The road wheel angle sensor 22 senses the angle and number of rotations of the output gear (not shown) of the motor actuator 20 and generates a road wheel angle signal 24 for the controller 26 . The controller 26 processes the steering wheel angle signal 15 , the road wheel angle signal 24 and a feedback current signal 34 to generate a control signal 36 . A current sensor 28 generates the feedback current signal 34 . The control signal 36 is applied to a motor driver circuit 30 . The motor driver circuit 30 generates an electric current 32 for a motor actuator 20 . As the electric current 32 is applied to the motor driver circuit 30 , the current sensor 28 continuously measures the electric current 32 . The current sensor 28 generates the feedback current signal 34 which is applied to the controller 26 . Simultaneously, the rack and pinion gear set converts the rotary motion of the steering wheel 12 into linear motion of the rack 16 . When the rack 16 moves linearly, the road wheels 18 pivot about their associated steering axes and the vehicle is steered. The motor actuator 20 is connected with the rack 16 through a known manner. The motor actuator 20 , when energized, provides torque to enable the vehicle operator to steer the vehicle.
Referring to FIG. 2, a flowchart of a compensation method performed by the controller 26 in the present invention. The controller 26 in a preferred embodiment has permanent and temporary memory storage capabilities. A step 38 is the entry point for the method 37 . At a step 40 the controller 26 is permanently programmed with a predetermined threshold value which is determined by vehicle testing. At a step 42 the controller 26 is permanently programmed with an initial offset value which functions as a default amount of offset within the steering control system 10 . The initial offset value is automatically subtracted from the electric current 32 during system operation when the steering control system 10 has not received an adequate amount of information to determine a precise amount of required compensation. For example, when the vehicle is initially powered up, the steering wheel angle signal 15 , the road wheel angle signal 24 , and the feedback current signal 34 have not been generated which causes a zero output for the control signal 36 thereby rendering the precise amount of required compensation in the system undeterminable.
At a step 44 the controller 26 takes samples of the generated control signal 36 by processing the generated steering wheel angle signal 15 , road wheel angle signal 24 , and feedback current signal 34 . Step 44 occurs when a vehicle operator turns the steering wheel 12 . At a step 46 the controller 26 compares the control signal 36 to the predetermined threshold value. When the control signal 36 is less than the predetermined threshold value, the sampled feedback current signal 34 is temporarily stored and set as an offset current signal at step 48 . At a step 50 the offset current signal is subtracted from the electric current 32 which is generated by the motor driver circuit 30 for the motor actuator 20 . In the preferred embodiment the electric current 32 is pulse-width-modulated. When the control signal 36 is greater than the predetermined threshold value at step 46 , the controller 26 will set the offset current signal equal to the initial offset value and subtract the initial offset value from the electric current 32 at step 50 , thereby improving the quality of current compensation. The method then loops back to step 44 .
Although the present invention has been described with regard to a steer-by-wire system, the invention is not limited to such a system. The present invention may be used with equal utility in other embodiments and is not limited to those embodiments disclosed, and variations and modifications may be made without departing from the scope of the present invention.
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An apparatus and method for a steering system which compensates a drive current for certain variables in a steer-by-wire and electrical power assist steering system. The present invention utilizes a steering wheel angle sensor, a road wheel angle sensor, and a controller for determining a precise time and amount of compensation for the drive current.
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RELATED APPLICATIONS
This application Ser. No. 13/077,664 claims the benefit of priority of U.S. Provisional Application Ser. No. 61/320,452, filed Apr. 2, 2010.
The contents of all related application(s) set forth above are incorporated herein by reference.
TECHNICAL FIELD
The present invention relates to pile driving systems and, more particularly, to pile driving systems adapted to drive and/or extract hollow pile members such as pipes.
BACKGROUND
Construction projects often require the placement of rigid elongate members into the ground. The rigid elongate members can manufactured from various shapes, sizes, and materials depending upon the intended use. The present invention is of particular significance in the context of driving a hollow pipe, such as a pipe pile or caisson, into the ground. For the purposes of describing the construction and use of the present invention, the term “pile” will be used herein to refer to any pile or caisson at least a portion of which is hollow.
Piles can be placed at a desired location in the ground using any one of a number of different methods. A hole can be excavated at the desired location, the pile inserted, and then backfill material can be arranged within the hole around the pile to secure the pile in place. More commonly, however, piles are driven into the ground using a pile driving system. A pile driving system typically applies a driving force on an upper end of the pile that drives or crowds the pile into the earth without excavation.
In some situations, the pile driving system combines a static driving force with vibratory forces to facilitate the driving and/or extracting of the pile. The static driving force is typically formed by the weight of the pile and the pile driving system and is directed along a drive axis that is substantially defined by a longitudinal axis of the pile. Typically, a support structure such as a crane is used to suspend the pile driving system and pile during operation of the pile driving system to insert and/or extract the pile.
The vibratory forces of a pile driving system that uses such forces are typically formed by a vibratory system that creates movement in both directions along the drive axis. A pile driving system that employs vibratory forces also typically employs a clamp system 20 to secure the vibratory system to the pile to ensure that the vibratory forces are effectively transmitted to the pile. In addition, a pile driving system employing vibratory forces further typically employs a suppressor for inhibiting the transmission of vibratory forces to the support structure.
The present invention relates to improved clamp system 20 s and methods for vibratory pile driving systems for driving and/or extracting hollow piles such as pipe piles and caissons.
SUMMARY
The present invention may be embodied as a clamp system for connecting a vibratory system defining a drive axis to a pile defining a pile inner surface. The clamp system comprises a frame, a plurality of clamp members, an actuator collar, and an actuator system. The frame comprising an attachment member adapted to be operatively connected to the vibratory system and a stop ring defining a stop cam surface. The plurality of clamp members defines first and second cam surfaces. The actuator collar defines an actuator cam surface. The actuator system displaces the actuator collar. The frame supports the actuator collar and the plurality of clamp members such that the first cam surfaces engage the actuator cam surface and the second cam surfaces engage the stop cam surface. Operation of the actuator system displaces the actuator collar towards the stop ring. As the actuator collar moves towards the stop ring, the actuator cam surface acts on the first cam surfaces and the stop cam surface acts on the second cam surfaces such that the clamp members are displaced away from the drive axis to place the clamp system in an engaged configuration. The clamp members are adapted frictionally to engage the pile inner surface when the clamp system is in the engaged configuration.
The present invention may also be embodied as a method of connecting a vibratory system defining a drive axis to a pile defining a pile inner surface, the method comprising the following steps. A frame comprising an attachment member adapted to be operatively connected to the vibratory system and a stop ring defining a stop cam surface is provided. A plurality of clamp members each defining first and second cam surfaces is provided. An actuator collar defining an actuator cam surface is arranged such that the actuator cam surface engages the first cam surfaces defined by the plurality of clamp members. The plurality of clamp members are arranged relative to the frame such that the stop cam surface defined by the stop ring engages the second cam surfaces. An actuator system for displacing the actuator collar is provided. The actuator system is operated to displace the actuator collar towards the stop ring such that the actuator cam surface acts on the first cam surfaces and the stop cam surface acts on the second cam surfaces to displace the clamp members away from the drive axis to place the clamp system in an engaged configuration in which the clamp members are adapted frictionally to engage the pile inner surface.
The present invention may also be configured as a clamp system for connecting a vibratory system defining a drive axis to a pile defining a pile inner surface, the clamp system comprising a frame, a plurality of clamp members, an actuator collar, and an actuator system. The frame comprises an attachment member adapted to be operatively connected to the vibratory system, a stop ring defining a stop cam surface, and a center member for fixing a distance between the attachment member and the stop ring. The plurality of clamp members is secured to the center member for limited motion along the drive axis and radially from the drive axis. Each clamp member defines first and second cam surfaces. The actuator collar defines an actuator cam surface. The actuator system displaces the actuator collar. The frame supports the actuator system and the actuator collar such that the first cam surfaces engage the actuator cam surface and the second cam surfaces engage the stop cam surface. Operation of the actuator system displaces the actuator collar towards the stop ring. As the actuator collar moves towards the stop ring, the actuator cam surface acts on the first cam surfaces and the stop cam surface acts on the second cam surfaces such that the clamp members are displaced away from the drive axis to place the clamp system in an engaged configuration. The clamp members are adapted frictionally to engage the pile inner surface when the clamp system is in the engaged configuration.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side elevation view of an example pile driving system incorporating an example of an internal pipe claim system of the present invention;
FIG. 2 is a side elevation view of the example of the internal pipe clamp system 20 depicted in FIG. 1 ;
FIG. 3 is a side section view of the example internal pipe clamp system 20 of FIG. 1 in a disengaged configuration; and
FIG. 4 is a side section view of the example internal pipe clamp system 20 of FIG. 1 in an engaged configuration.
DETAILED DESCRIPTION
FIG. 1 depicts a clamp system 20 forming part of a pile driving system 22 for driving a pile 24 into a desired location 26 in the earth 28 . The example pile 24 is hollow and, more particularly, takes the form of a pipe or pipe pile.
In FIG. 1 , the example pile driving system 22 comprises, in addition to the clamp system 20 , a vibratory system 30 and a suppressor system 32 . The pile driving system 22 and pile 24 are supported by a support structure 34 comprising a crane 36 and a crane line 38 . The example crane line 38 is operatively connected to the suppressor 32 , and the example suppressor 32 is rigidly connected to the vibratory system 30 . The example vibratory system 30 is in turn rigidly connected to the clamp system 20 . The example clamp system 20 substantially rigidly connects vibratory system 30 to the pile 24 .
In general, the clamp system 20 is connected to the vibratory system 30 such that the vibratory forces are substantially rigidly transmitted or transferred from the vibratory system 30 to the clamp system 20 . The clamp system 20 in turn engages the pile 24 such that the vibratory forces are substantially rigidly transmitted or transferred from the clamp system 20 to the pile 24 as will be described in further detail below.
FIG. 2 illustrates that the example clamp system 20 comprises a frame 40 , an actuator collar 42 , a plurality (two or more) clamp assemblies 44 , and an actuator system 46 . FIGS. 3 and 4 illustrate that the example frame 40 comprises an attachment member 50 , a center member 52 , a stop ring 54 , a guide member 56 , and a plurality (two or more) of cylinder flanges 58 .
The example attachment member 50 takes the form of a beam that is adapted to be rigidly connected to the vibratory system 30 such that the attachment member 50 is substantially symmetrically arranged about a drive axis A defined by the vibratory system 30 . The attachment member 50 is rigidly connected to a base location of the center member 52 such that the center member 52 substantially symmetrically extends along the drive axis A.
The example stop ring 54 is rigidly connected to the center member 52 at an intermediate location along the length of the center member 52 . The guide member 56 is rigidly connected at an end location of the center member 52 distal from the attachment member 50 . The intermediate location is spaced between the end location and the base location.
The example cylinder flanges 58 are rigidly connected to the attachment member 50 and/or the center portion 52 such that the cylinder to flanges 58 extend along the drive axis A and radially extend from the drive axis A.
The example clamp assemblies 44 each comprise a clamp member 60 operatively connected by at least one retaining bolt 62 such that the clamp members 60 may move between a disengaged position ( FIG. 3 ) and an engaged position ( FIG. 4 ) relative to the center member 52 . Return springs 64 are configured to bias the clamp members 60 into the disengaged position. The example clamp members 60 are arranged in groups of two opposing clamp members. The example clamp system 20 comprises four of the example clamp assemblies 44 , so the example clamp members 60 are arranged in two groups of two, with each clamp member 60 arranged on an opposite side of the drive axis A from the other clamp member 60 in its group. In addition, in the example clamp system 20 , each clamp member 60 is provided with two of the retaining bolts 62 and two of the return springs 64 .
When moving between the disengaged and engaged positions, the example clamp members 60 move both along the drive axis A and radially with respect to the drive axis A. In particular, at least one slot 66 is formed in each of the clamp members 60 to allow movement of the clamp members 60 within a limited range of movement along the drive axis A. In this context, the retaining bolts 62 and compression and expansion of the return springs 64 allow movement of the clamp members 60 within a limited range radially with respect to the drive axis A. In the example clamp system 20 , one of the slots 66 is provided for each of the retaining bolts 62 , so two slots 66 are formed in the example clamp members 60 .
The example actuator system 46 comprises at least one actuator 70 comprising a cylinder 72 and a shaft 74 . As is conventional, energizing the actuator 70 in at least a first mode causes the shaft 74 to be extended from a retracted configuration ( FIG. 3 ) towards an extended configuration ( FIG. 4 ) relative to the cylinder 72 . Optionally, the actuator 70 may be energized in a second mode in which the shaft is retracted from the extended configuration towards the retracted configuration with respect to the cylinder 72 . The actuators 70 may be pneumatic, electrical, or hydraulic devices as necessary to exert sufficient clamping force as will be described in further detail below. The example actuators 70 are conventional hydraulic devices powered by pressurized hydraulic fluid. The example actuator system 46 of the example clamp system 20 comprises four actuators, one for each of the clamp assemblies 44 . The example actuator system 46 further comprises an actuator housing 76 that extends from the attachment member 50 and protects the actuator system 46 .
A cylinder coupler 80 is rigidly secured to the cylinder 70 , and a cylinder pin 82 operatively connects the cylinder 72 for pivoting movement relative to the cylinder flange 58 of the frame 40 . A shaft coupler 84 is rigidly secured to the shaft 74 , and a shaft pin 82 operatively connects the shaft 74 for pivoting movement relative to a shaft flange 88 forming part of the actuator collar 42 of the example clamp system 20 .
The actuator collar 42 defines an actuator cam surface 90 , while the stop ring 54 defines a stop cam surface 92 . Each of the clamp members 60 defines a first cam surface 94 and a second cam surface 96 . The actuator cam surface 90 and the first cam surface 94 are configured to extend at a first angle with respect to the drive axis A, while the stop cam surface 92 and the second cam surface 96 are configured to extend at a second angle with respect to the drive axis A.
Accordingly, with the actuator collar 42 pivotably connected to the actuators 70 and the clamp members 60 movably secured relative to the center member 52 as depicted in FIGS. 3 and 4 , the return springs 64 bias the clamp members 60 towards the drive axis A such that the first cam surfaces 94 engage the actuator cam surface 90 . Similarly, with the stop ring 54 rigidly supported by the center member 52 and the clamp members 60 movably secured relative to the center member 52 as depicted in FIGS. 3 and 4 , the return springs 64 bias the clamp members 60 towards the drive axis A such that the second cam surfaces 96 engage the stop cam surface 92 .
With reference to FIGS. 3 and 4 , the use of the example clamp assembly 20 will now be described in further detail. Initially, it should be noted that the pile 24 comprises a pile upper edge 120 , a pile inner surface 122 , and a pile outer surface 124 . The pile upper edge 120 defines a pile opening 126 , and the pile inner surface 122 defines a pile chamber 128 . The pile 24 further defines a pile axis B.
To begin the process of engaging the clamp system 20 with the pile 24 , the actuators 70 are first arranged in the retracted configuration such that the clamp members 60 are in the disengaged configuration. The pile driving system 22 is then displaced such that the clamp system 20 is inserted at least partly through the pile opening 126 and substantially arranged within the pile chamber 128 . The guide member 56 defines slanted guide surfaces 130 that engage the pile upper edge 120 and guide the clamp system 20 through the pile opening 126 and into the pile chamber 128 . The clamp system 20 may be arranged such that the pile upper edge 120 engages the attachment member 50 , or the pile upper edge 120 may be spaced from the attachment member 50 . FIGS. 3 and 4 illustrate the situation in which the pile upper edge 120 engages the attachment member 50 . At this point, the drive axis A may not be aligned with the pile axis B.
The actuators 70 are next energized in the first mode to extend the shafts 74 relative to the cylinders 72 . As the shafts 74 move towards the extended configuration, the actuator collar 42 is displaced along the drive axis A away from the attachment member 50 and towards the stop ring 54 . As the actuator collar 42 moves towards the stop ring 54 , the actuator cam surface 90 engages the first cam surfaces 94 and the stop cam surface 92 engages the second cam surfaces 94 . To accommodate this displacement of the movable actuator collar 42 relative to the fixed stop ring 54 , the respective cam surfaces 90 and 92 engage the associated cam surfaces 94 and 96 , respectively, to cause the clamp members 60 to move away from the drive axis A. The return springs 64 compress to allow the movement of the clamp members 60 away from the drive axis A.
Eventually, the distance between outer surfaces 140 of the clamp members 60 equals the distance between opposite portions of the pile inner surface 122 and the clamp members 60 engage the pile 24 . The clamp members 60 frictionally engage the pile 24 at this point. Additionally, the clamp system 20 will selfcenter such that the drive axis A is substantially aligned with the pile axis B.
It should be noted that the actuator system 46 and clamp assemblies 44 should be configured such that the distance between opposing outer surfaces 140 of the clamp members 60 may be greater than the inner diameter of the pile 24 when the actuators 70 are in the fully extended configurations. The actuators 70 may thus be configured to apply sufficient clamping pressure to the clamp members 60 such that the clamp members frictionally engage the pile inner surface 122 to inhibit movement of the clamp members 60 relative to the pile during normal operation of the pile driving system 22 . The pile driving system 22 is then operated to drive the pile 24 to a desired depth at the desired location 26 .
To disengage the clamp system 20 from the pile 24 , the actuators 70 may be placed in a de-energized configuration to allow the return springs to force the clamp members 60 towards the drive axis A and thus the actuator collar 42 towards the attachment member 50 , thereby forcing the shafts 74 towards the retracted configuration with respect to the cylinders 72 . Optionally, the actuators 70 may be energized in the second mode to force the shafts into the retracted configuration. At some point between the engaged configuration and the disengaged configuration, the clamp members 60 disengage from the pile inner surfaces 122 , allowing the clamp system 20 to be removed from the pile chamber 128 .
A clamp system such as the example clamp system 20 described above allows the pile 24 to be driven without engaging the pile external surface.
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A clamp system includes a frame, a plurality of clamp members, an actuator collar, and an actuator system. The frame includes an attachment member and a stop ring defining a stop cam surface. The clamp members each define first and second cam surfaces. The actuator collar defines an actuator cam surface. The actuator system displaces the actuator collar. The frame supports the actuator collar and the plurality of clamp members such that the first cam surfaces engage the actuator cam surface and the second cam surfaces engage the stop cam surface. Operation of the actuator system displaces the actuator collar towards the stop ring. As the actuator collar moves towards the stop ring, the actuator cam surface acts on the first cam surfaces and the stop cam surface acts on the second cam surfaces such that the clamp members place the clamp system in an engaged configuration.
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CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of U.S. patent application Ser. No. 10/116,817 filed Apr. 5, 2002 entitled “PROCESSING OCCLUDED WINDOWS DURING APPLICATION SHARING,” now U.S. Pat. No. 7,028,266, issued Apr. 11, 2006, which application is incorporated herein in its entirety.
TECHNICAL FIELD
This invention relates generally to the technology of application sharing and, more particularly, relates to a system and method for improving a viewer's experience during application sharing.
BACKGROUND OF THE INVENTION
As computers and computer networks become more pervasive in the home and workplace, many old methods for performing everyday tasks are being replaced or streamlined through the use of computer networking technology. For example, many employees are now able to have a virtual presence in their workplace by logging into a computer network maintained by their employer. One of the most striking developments in computer networking technology has been the advent of remote collaboration.
One of the oldest forms of processing data is the meeting or conference, whereby multiple individuals focus their attention on common subject matter to arrive at a joint decision, consensus, or product. Increasingly, such meetings are now taking place virtually over computer networks through the use of application sharing technologies. Such technologies enable a sharing user to share an application with various viewing users. The display produced by the application running on the sharer's computer is made available via a computer network to the viewers' computers. In some cases, the sharer may pass control of the application to a viewer, whereby the viewer's control inputs are then communicated back to the sharer's computer, where the actions associated with the inputs are executed, and the resulting changed display is shared back out to the viewers.
Although application sharing can play a critical role in maintaining or increasing productivity and cooperation, certain problems with current application sharing systems sometimes create a confusing user experience. For example, a sharing user may simultaneously have on their screen a shared window and an unshared window. In an ideal case, a viewing party, or viewer, sees on their computer display and image of the shared window in whole, and does not see the unshared window or any artifacts caused thereby. However, if the sharing user moves the unshared window in such a way as to partially or wholly occlude the shared window, then the viewing user can no longer see the occluded portion. Furthermore, since the unshared window cannot be shown, the occluded region is often filled in with hash marks or other placeholder imagery. The same situation may occur when an unshared window is generated automatically, such as when a message notification or system window is generated.
The screen presentation at the viewer's machine in such a situation is often unpleasant to the viewer, and indeed may be quite confusing and discomfiting to the novice user. A system and method are needed whereby the viewer experience of application sharing during periods of whole or partial occlusion is improved over prior systems.
SUMMARY OF THE INVENTION
A novel system and method are described for providing a simple and pleasing viewer experience during application sharing when a shared window is occluded in whole or in part by an unshared window. When an unshared window becomes situated in such a manner as to occlude some or all of a shared window during application sharing, the occluded portion is generated from a prior view taken at a time when the portion in question was not obscured. If the percentage of the shared window that is obscured rises above a threshold value, then the entire shared window view is generated from a prior view, and the viewer is informed in an embodiment of the invention that the sharer has paused the sharing session. In an embodiment, a predetermined amount of time is allowed to transpire in such a situation before the viewer is informed that the sharer has paused the sharing session. In this way, large but temporary occlusions are not conveyed to the viewer, and the predetermined delay is short enough that a noticeable delay in sharing is not created in the viewer's perception.
BRIEF DESCRIPTION OF THE DRAWINGS
While the appended claims set forth the features of the present invention with particularity, the invention, together with its objects and advantages, may be best understood from the following detailed description taken in conjunction with the accompanying drawings of which:
FIG. 1 is a block diagram generally illustrating an exemplary computer system usable in an implementation of an embodiment of the invention;
FIG. 2 is a schematic diagram showing the architecture of a network system within which an embodiment of the invention may be implemented, including multiple computers comprising a sharer computer and viewer computers;
FIG. 3 is a schematic diagram illustrating in greater detail the placement and function of an application sharing program in an embodiment of the invention with respect to a sharer computer and a viewer computer;
FIG. 4A is a simplified sharer screen representation showing a sharer display of a shared window without occlusion by an unshared window;
FIG. 4B is a simplified sharer screen representation showing a sharer display of a shared window during partial occlusion by an unshared window;
FIG. 5A is a simplified viewer screen representation showing a viewer display of a shared window without occlusion by an unshared window;
FIG. 5B is a simplified viewer screen representation showing a viewer display of a shared window during partial occlusion by an unshared window according to a prior application sharing occlusion-handling scheme;
FIG. 6 is a display representation with schematic diagram of memory maps showing a viewer display of a shared window during partial occlusion by an unshared window in an embodiment of the invention, and a mechanism for disguising a small partial occlusion to the viewer during application sharing in an embodiment of the invention;
FIG. 7 is a display representation with schematic diagram of memory maps showing a viewer display of a shared window during total or partial occlusion by an unshared window in an embodiment of the invention, and a mechanism for disguising a large occlusion to the viewer during application sharing in an embodiment of the invention; and
FIG. 8 is a flow chart illustrating a process for preparing a viewer display of a shared window to account for a large or small occlusion of the shared window by an unshared window according to an embodiment of the invention.
DETAILED DESCRIPTION OF THE INVENTION
Turning to the drawings, wherein like reference numerals refer to like elements, the invention is illustrated as being implemented in a suitable computing environment. Although not required, the invention will be described in the general context of computer-executable instructions, such as program modules, being executed by a personal computer. Generally, program modules include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Moreover, those skilled in the art will appreciate that the invention may be practiced with other computer system configurations, including hand-held devices, multi-processor systems, microprocessor based or programmable consumer electronics, network PCs, minicomputers, mainframe computers, and the like. The invention is primarily for use in a networked environment and may further be practiced in distributed computing environments where tasks are performed by remote processing devices that are linked through a communications network. In a distributed computing environment, program modules may be located in both local and remote memory storage devices.
FIG. 1 illustrates an example of a suitable computing system environment 100 usable in an implementation of the invention. The computing system environment 100 is only one example of a suitable computing environment and is not intended to suggest any limitation as to the scope of use or functionality of the invention. Neither should the computing environment 100 be interpreted as having any dependency or requirement relating to any one or combination of components illustrated in the exemplary operating environment 100 .
The invention is operational with numerous other general purpose or special purpose computing system environments or configurations. Examples of well known computing systems, environments, and/or configurations that are 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, set top boxes, programmable consumer electronics, network PCs, minicomputers, mainframe computers, distributed computing environments that include any of the above systems or devices, and the like.
An exemplary system for implementing the invention includes a general-purpose computing device in the form of a computer 110 . Components of the computer 110 generally include, but are not limited to, a processing unit 120 , a system memory 130 , and a system bus 121 that couples various system components including the system memory to the processing unit 120 . The system bus 121 may be any of several types of bus structures including a memory bus or memory controller, a peripheral bus, and a local bus using any of a variety of bus architectures. By way of example only, and not limitation, such architectures include Industry Standard Architecture (ISA) bus, Micro Channel Architecture (MCA) bus, Enhanced ISA (EISA) bus, Video Electronics Standards Associate (VESA) local bus, and Peripheral Component Interconnect (PCI) bus also known as Mezzanine bus.
Computer 110 typically includes a variety of computer readable media. Computer readable media can be any available media that can be accessed by computer 110 and includes both volatile and nonvolatile media, removable and non-removable media. By way of example only, 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 disk 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 computer 110 .
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 (such as, for example, voltage or current level, voltage or current pulse existence or nonexistence, voltage or current pulse width, voltage or current pulse spacing, etc.) 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 are also included within the scope of computer readable media.
The system memory 130 includes computer storage media in the form of volatile and/or nonvolatile memory such as read only memory (ROM) 131 and random access memory (RAM) 132 . A basic input/output system 133 (BIOS), containing the basic routines that help to transfer information between elements within computer 110 , such as during start-up, is typically stored in ROM 131 . RAM 132 typically contains data and/or program modules that are immediately accessible to and/or presently being operated on by processing unit 120 . By way of example, and not limitation, FIG. 1 illustrates RAM 132 as containing operating system 134 , application programs 135 , other program modules 136 , and program data 137 .
The computer 110 may also include other removable/non-removable, volatile/nonvolatile computer storage media. By way of example only, FIG. 1 illustrates a hard disk drive 141 that reads from or writes to non-removable, nonvolatile magnetic media, a magnetic disk drive 151 that reads from or writes to a removable, nonvolatile magnetic disk 152 , and an optical disk drive 155 that reads from or writes to a removable, nonvolatile optical disk 156 such as a CD-ROM or other optical media. Other removable/non-removable, volatile/nonvolatile computer storage media that can be used in the exemplary operating environment include, but are not limited to, magnetic tape cassettes, flash memory cards, digital versatile disks, digital video tape, solid state RAM, solid state ROM, and the like. The hard disk drive 141 is typically connected to the system bus 121 through a non-removable memory interface such as interface 140 , and magnetic disk drive 151 and optical disk drive 155 are typically connected to the system bus 121 by a removable memory interface, such as interface 150 .
The drives and their associated computer storage media, discussed above and illustrated in FIG. 1 , provide storage of computer readable instructions, data structures, program modules and other data for the computer 110 . In FIG. 1 , for example, hard disk drive 141 is illustrated as storing operating system 144 , application programs 145 , other program modules 146 , and program data 147 . Note that these components can either be the same as or different from operating system 134 , application programs 135 , other program modules 136 , and program data 137 . Operating system 144 , application programs 145 , other program modules 146 , and program data 147 are given different numbers herein to illustrate that, at a minimum, they are different copies. A user may enter commands and information into the computer 110 through input devices such as a keyboard 162 , pointing device 161 (commonly referred to as a mouse), and trackball or touch pad. Other input devices (not shown) may include a microphone, joystick, game pad, satellite dish, scanner, or the like. These and other input devices are often connected to the processing unit 120 through a user input interface 160 that is coupled to the system bus, but may be connected by other interface and bus structures, such as a parallel port, game port or a universal serial bus (USB). A monitor 191 or other type of display device is also connected to the system bus 121 via an interface, such as a video interface 190 . In addition to the monitor, computers may also include other peripheral output devices such as speakers 197 and printer 196 , which may be connected through an output peripheral interface 195 .
In the implementation of an embodiment of the invention, the computer 110 operates in a networked environment using logical connections to one or more remote computers, such as a remote computer 180 . The remote computer 180 may be a personal computer, a router, a network PC, a peer device or other common network node, and in any case the remote computer or computers typically include many or all of the elements described above relative to the personal computer 110 , although only a memory storage device 181 has been illustrated in FIG. 1 . The logical connections depicted in FIG. 1 include a local area network (LAN) 171 and a wide area network (WAN) 173 , but the computer 110 may additionally or alternatively use one or more other networking environments. Networking environments of all types are commonplace in offices, enterprise-wide computer networks, intranets and the Internet.
The computer 110 should include facilities for accessing the networks to which it is attachable. For example, when used in a LAN networking environment, the personal computer 110 is connected to the LAN 171 through a network interface or adapter 170 . Another node on the LAN, such as a proxy server, may be further connected to a WAN such as the Internet. When used in a WAN networking environment, the computer 110 typically includes a modem 172 or other means for establishing communications directly or indirectly over the WAN 173 , such as the Internet. The modem 172 , which may be internal or external, may be connected to the system bus 121 via the user input interface 160 , or other appropriate mechanism. In a networked environment, program modules depicted relative to the personal computer 110 , or portions thereof, may be stored in the remote memory storage device. By way of example, and not limitation, FIG. 1 illustrates remote application programs 185 as residing on memory device 181 . It will be appreciated that the network connections shown are exemplary and other means of establishing a communications link between the computers may be used. It is not intended to limit the invention to use in a hard-wired network environment, since it may also be used in transiently connected environments, such as for example a wholly or partially wireless network environment interconnected wholly or partially via optical, infrared, and/or radio frequency wireless connections.
Herein, the invention is described with reference to acts and symbolic representations of operations that are performed by one or more computers, unless indicated otherwise. As such, it will be understood that such acts and operations, which are at times referred to as being computer-executed, include the manipulation by the processing unit of the computer of electrical signals representing data in a structured form. This manipulation transforms the data or maintains it at locations in the memory system of the computer, which reconfigures or otherwise alters the operation of the computer in a manner well understood by those skilled in the art. The data structures where data is maintained are physical locations of the memory that have particular properties defined by the format of the data. However, while the invention is being described in the foregoing context, it is not meant to be limiting as those of skill in the art will appreciate that various of the acts and operation described hereinafter may also be implemented in hardware.
FIG. 2 illustrates schematically a networking environment in which the present invention in preferably implemented. The architecture of such a system comprises one or more viewer computers illustrated as computers 201 , 203 , and 205 , connected to a sharer computer 207 via a network 209 . Each computer 201 , 203 , 205 , 207 is connected or connectable to the network 209 and hence to the others of computers 201 , 203 , 205 , 207 via network connections 211 , 213 , 215 , and 217 . The network connections 211 , 213 , 215 , 217 and computers 201 , 203 , 205 , 207 are as discussed above more generally with respect to FIG. 1 . The network may be of any type, including, for example, a LAN, such as found in an office, university or other setting, a WAN such as the Internet, a MAN, or any other tangible or intangible, fixed or transient mechanism for computer interconnectivity. While higher data transfer rates are generally preferable to lower data transfer rates, there is no limit or requirement as to the speed of the network 209 . In addition, the network 209 may be a single network, or alternatively may be comprised of multiple networks of the same or different types and/or speeds. It will be understood that in many but not all cases, the network will further comprise routers, servers, and/or other computing devices in addition to the endpoint devices 201 , 203 , 205 , 207 involved in the collaborative effort.
Specific exemplary architectures of the sharer computer 207 and a viewer computer 201 are illustrated in greater detail schematically in FIG. 3 . It will be understood that although only one viewer computer is illustrated in FIG. 3 , there can be more than one such computer in an implementation of the invention, as illustrated by way of FIG. 2 . Sharer computer 307 is illustrated as being connected via networking connection 319 to viewer computer 301 . As will be appreciated by those of skill in the art, network connection 319 can include some or all of the network types and network connections discussed above, as well as other network types and connections alternatively or additionally.
One or more user mode processes of interest 321 are running on sharer computer 307 . Such processes include processes, such as a programs, from which information is being shared to one or more viewers such as viewer 307 . The processes of interest 321 will be referred to hereinafter as shared processes, with the understanding that the information generated by the processes 321 need not be shared completely. That is, the information shared may consist of a subset of the information generated by such a process 321 . Many shared process can also be used in a non-shared manner. For example, a word processing program may be used by the sharer for non-collaborative document production, and may then be used in a shared manner for group editing of the same or another document. In either mode, the processes 321 and the operating system of the sharer computer 307 perform certain steps. For example, whether or not the process 321 is shared, the output of the process 321 will still generally be output to the graphics display driver of the sharer computer 307 .
If the application sharing program 323 is active, such as during a sharing session, then other processes unique to the collaborative setting also take place. In particular, the application sharing program 323 , which is communicably linked to the process 321 , receives information from the process 321 and transfers information to the process 321 . Although the bi-directional flow of information between the process 321 and application sharing program is illustrated by a double arrow, note that the mechanisms for transfer may vary depending upon direction. For example, the process 321 need not even be aware of the presence or operation of the application sharing program 323 for the application sharing program 323 to receive information from the process 321 .
Typically, the application sharing program 323 is communicably linked to an interceptor filter placed in the display path for the process 321 . Such a filter may be placed just before the graphics device interface (GDI) or similar interface in such a manner as to read, in a non-intrusive manner, all information sent to the screen of computer 307 by a shared process. In the WINDOWS operating system produced by MICROSOFT of Redmond, Wash., when an application wants to display an object, it calls a GDI function and sends the various parameters for the object. In turn, the GDI sends commands to the screen to cause it to actually paint the object. In contrast, the mechanism for transferring information from the application sharing program 323 to the process 321 need not involve the display path at all, and may instead involve a direct transfer of information.
Regardless, the application sharing program 323 is also communicably linked to the networking facilities 325 of the sharer computer 307 . Such facilities 325 may include any networking communications stack or other protocol arrangement as well as the hardware required for accessing the network connection 319 , as discussed above with respect to FIG. 1 . Across the network connection 319 , a counterpart application sharing program 327 running on the viewer computer 307 is communicably linked to the sharer computer 307 via the network connection 319 and the networking facilities 329 of the viewer computer. The networking facilities 329 may be similar to the networking facilities 325 of the sharer computer. The counterpart application sharing program 327 receives input from shared process 321 via the network connection 319 and also potentially from a user of the viewer computer 301 , via one or more input channels 331 , such as a keyboard, mouse, etc. as discussed above with respect to FIG. 1 . Additionally, the counterpart application sharing program 327 outputs material for display to a display process 333 such as a GDI or similar interface, or other display process. Note that the sharing computer also preferably includes input channels 335 such as those described above for receiving user input, some of which may be directed to and received by the process of interest 321 .
The general operation of the architecture and components illustrated in FIG. 3 will be described briefly in overview before giving a detailed exposition of the processes involved in embodiments of the invention. Initially the shared process 321 is running on sharer machine 307 , and is processing one or more documents or files. The user of the sharer machine 307 can begin execution of the application sharing program 323 by selecting an icon on the display screen of machine 307 or otherwise. Preferably, upon prompting by the user either via start-up of the application sharing program 321 or by selection of an option during execution of the application sharing program 321 , the user of sharer machine 307 is presented with a list of all sharable documents currently open on machine 307 , including those being processed by process 321 . The user may select documents to be shared as well as a viewer with whom the documents will be shared.
The application sharing program 327 resident on the viewer machine 329 should be running before sharing of documents occurs, and may be run in the same manner as described above. At this point, document sharing may occur. That is, of all the documents selected as shared by the user of sharer machine 307 , data corresponding to all or some shared windows is transmitted to the viewer computer 301 for display on the screen or display device of that computer 301 in an embodiment of the invention.
FIG. 4 illustrates two separate views 402 , 404 of a sharer display 401 taken at different points in time. In the first view 402 , two separate windows 403 , 405 appear in their entireties on the sharer display. In this example, one window 405 is shared while the other 403 is unshared. That is, a viewer machine communicably connected to the sharer machine and participating in a sharing session will not display the unshared window 403 .
In the second view 404 , the unshared window 403 has been moved so that it is positioned in such a way as to partially occlude shared window 405 . It will be appreciated that content in a shared window may be obscured in any number of other ways. For example, using the WINDOWS brand operating system produced by MICROSOFT of Redmond, Wash., a user may strike a key combination to display a system window. For instance, when a user enters the key combination <alt><tab> simultaneously, a system window is generated and sent to the display, showing open windows that the user may wish to shift to. Such a window typically appears at the center of the display. Similarly, other windows may be created in a position that obscures the shared window, rather than being moved into position. For example, many notification windows notifying a user that he or she has mail, that a print job has completed, and so forth, are created in a prominent position on the display in front of whatever material was previously displayed there. Many such windows are short-lived, since they are typically not windows in which a user may stay and work or otherwise manipulate data.
When a shared window is obscured, as is the case with window 405 in FIG. 4B , a section such as section 407 of the shared window becomes hidden on the sharer's display. Since the hidden portion is no longer painted on the display by the display processing system, there are no longer any paint commands regarding that region to be intercepted and shared with the viewer, even though the viewer is authorized to see such a region since it is part of a shared document. In particular, many operating systems never paint obscured information. For example, The Win32 painting model is that an obscured screen portion simply does not paint, and thus does not produce any GDI painting commands. Thus, for application sharing systems such as NETMEETING by MICROSOFT that intercept GDI paint commands, or similar commands or instructions, to recreate a display for an application sharing viewer, there is no longer any convenient way to know what lies in an obscured region.
FIG. 5 shows the viewer experience in prior application sharing systems in the situation where a shared window is obscured. In particular, the first display view 502 shows the viewer display 501 at a time when the shared window 505 , corresponding to window 405 , is not obscured on the sharer's display. This corresponds to the case illustrated in view 402 of FIG. 4A . As can be seen, the shared window 405 is in full view as window 505 , while the unshared window 403 does not appear at all, since it is by definition not to be shared.
Display view 504 of FIG. 5B illustrates the prior viewer experience when an unshared window such as window 403 is positioned in front of the shared window 405 on the sharer's display. In particular, the viewer display 501 shows the unobscured portions of the shared window 505 , while filling the area 507 corresponding to the obscured portion with a place-keeper such as hash marks 509 . This type of solution may disorient and confuse novice or infrequent users of the application sharing technology.
FIGS. 6 and 7 illustrate techniques for constructing viewer display representations for presenting a region of a shared window corresponding to a region that has been obscured on the sharer display, according to embodiments of the invention. These figures will be discussed below to give an overview according to embodiments of the invention after which the process of display construction will be discussed in greater detail with respect to FIG. 8 .
FIG. 6 illustrates a technique for reconstructing a viewer display when a small portion of a shared window, such as less than about 30% of the window's original area, has become obscured. The shared window representation 604 on viewer display 602 does not contain any apparently obscured regions although the shared window has been partially obscured to a small degree in the sharer region corresponding to reconstructed viewer region 603 . An obscuring event may be as illustrated in display 404 of FIG. 4B or otherwise. As can be seen from FIG. 6 , the viewer display 602 of the shared window contains shared data in all regions of the window regardless of the obscuring event at the sharer display.
Memory maps 605 and 607 illustrate the manner in which the viewer display is constructed after a small partial obscuring of a shared window. Maps 605 and 607 may be bitmaps stored in the memory of the viewer computer hosting the viewer display. Map 605 corresponds to the current shared data corresponding to the current sharer view of the shared window. It can be seen that map 605 is not a complete picture of the shared window, but rather contains an obscured region 609 for which no shared data is sent to the viewer computer, due to the obscuring event. In contrast, map 607 corresponds to a partial prior set of shared data associated with the shared window before the obscuring event, and gives a complete picture of the obscured region or any newly obscured region at that prior point in time. Thus, map 605 provides an incomplete but current view of the shared window, while map 607 provides outdated information to complete the viewer display of the shared window.
To construct the viewer display of the shared window after the obscuring event, different parts of each map 605 , 607 are combined to yield a seemingly complete view. In particular, since the portion of current map 605 outside of obscured region 609 is current, this portion is used to construct the unobscured region of the viewer display, i.e. region 601 . However, since the current map 605 does not contain data corresponding to the obscured region 609 , it cannot supply any such data for reconstructing the corresponding region 603 of the viewer display. Therefore, data for this region 603 is gleaned from the corresponding region 611 of the prior map 607 .
Although potential complexities arise by virtue of this approach, they are unlikely, and are somewhat mitigated by the bifurcated nature of the system as will be explained by reference to FIG. 7 below. For example, since the reconstructed region 603 of the view display is not current data, there is a possibility that the current data in the regions outside of region 603 , such as region 601 , will become noticeably inconsistent with the data in the reconstructed region 603 . This could happen when the sharer scrolls the contents of a partially obscured window where the obscured area is relatively small. In such a case, the viewer will see region 603 remaining static while all other portions of the shared window view scroll.
It has been empirically observed that the possibility of viewer disruption presented by the technique described above with respect to FIG. 6 is relatively minor. This is because, in general, obscuring events that affect less than 30% of the shared window's original area are caused by the presentation on the sharer display of short-lived windows such as system windows or notification windows. Therefore, the obscured condition will often not persist long enough for bothersome inconsistencies to develop in the viewer display.
It has been observed that larger obscuring events, such as those that affect more than about 30% of the shared window's original area, are often associated with more long-lived windows, and as such the technique illustrated via FIG. 6 is not optimally suited for reconstructing the viewer display in such cases. In particular, the larger the portion of the viewer display of the shared window that is reconstructed from outdated information, the more noticeable it will become to the viewer that they are not seeing a current view of the shared window. Furthermore, the longer the obscuring condition remains in effect, the more likely it will become that the viewer will notice and be disturbed or distracted by inconsistencies in the viewer display of the shared window. However, note that in a preferred embodiment of the invention, the duration of a small obscuring event is not a factor in deciding how to treat that event. That is, long-lived small obscuring events and short-lived small obscuring events are both treated the same in a preferred embodiment, although such is not required.
For the above reasons, a different technique for constructing the viewer display of the shared window is used when the obscured portion of the shared window exceeds 30% of the window's original unobscured area, in accordance with an embodiment of the invention. The threshold value of 30% for switching reconstruction modes has been determined to work well, although other thresholds less than or greater than 30% are also within the scope of the invention. For example, a threshold of 10%, 20%, 40%, 50%, 60%, 70%, 80%, or 90% may be used, or any other value that allows a distinction to be made between at least two classes of obscuring events so that such classes may be treated using different techniques. Note that it is also not critical that the same threshold value be used for every type of shared window, but rather the invention also includes the use of a variable threshold adapted to account for application type, sharer display size, or any other consideration.
With reference to FIG. 7 , a reconstruction technique usable in the event of a relatively large obscuring phenomenon according to this embodiment is illustrated. The viewer display 704 presents a representation of a shared window 701 to the viewing user. This discussion assumes that the shared window 701 has been obscured on the sharer display in the region corresponding to region 703 on the viewer display, and the extent of obscuring is substantial, such as, for example, greater than 30% or other threshold value as discussed above.
In this case, using outdated information from prior displays to fill in the obscured region may result in discomfort or confusion for the viewer due to the extent to which the shared window is obscured and hence outdated. Rather, in this embodiment, the entire shared window representation on the viewer machine is reconstructed using prior display data 705 taken before the occlusion occurred. Thus, all of the shared window representation 702 corresponds to outdated information. To prevent a viewer from coming to the conclusion that the displayed representation of the shared window corresponds to the actual current contents of the shared window, it is desirable in an embodiment of the invention to present a message on the viewer display 704 , informing the viewer that the sharing session has been paused by the sharer. In addition, the content of the viewer representation of the shared window may be “washed out” or otherwise modified to indicate a disabled or invalid condition.
Although the aforementioned technique is based on the observation that phenomena that obscure large portions of a shared window tend to be long-lived, there are situations where a large obscuration occurs for a brief period of time. For example, a sharing user may briefly activate an unshared window in order to copy data, and then switch back to the shared window to paste the data therein. In such situations, it has been observed that it is preferable to freeze the viewer representation of a shared window without presenting a message that the sharing session has been paused, since the obscuring condition soon passes.
Since there may be no technique for determining in every case beforehand how long a particular obscuring event may last, it is desirable to wait a predetermined amount of time once a large obscuring occurs before presenting the viewer with the message that the viewing session has been paused, and/or washing out the viewer display of the shared window. One reason to use this technique is that since the viewing user cannot see the sharing user, the viewing user cannot tell the difference between an image that is slightly out-of-date and an updated image wherein the sharing user has not made any changes to the shared material. It has been determined that an interval of 5 seconds provides good results in this capacity, however any other amount of delay may be used without departing from the scope of the invention.
The flow chart of FIG. 8 illustrates a process used in an embodiment of the invention to reconstruct the viewer display of a shared window during application sharing. Initially at node 801 , the application sharing process running on the viewer machine awaits new window information from the application sharing process running on the sharer machine. That is, it awaits the arrival of a window list and order packet. When new window data is received, the process transitions to decision 803 , where it analyzes the received window data to determine whether a top level shared application window is obscured to any degree by an unshared application window. If it is determined at step 803 that no unshared application window obscures a top level shared application window, then the process flows to step 805 . At step 805 , the process constructs the viewer display of the shared window using the new window information and returns to step 801 to await further window information.
If at step 803 it is instead determined that a top level shared application window is obscured to some degree by an unshared application window, then the process continues to step 807 , where it is determined whether the amount of the shared application window that is obscured is less than 30% of the original area of the shared application window. Preferably, the degree to which the area of the shared application window is obscured is evaluated in view of the cumulative affects of all obscuring phenomena. That is, an obscuring of 30% or more may occur as a result of separate obscuring events each of which obscures less than 30% of the original area of the shared application window.
If it is determined at step 807 that the amount of the shared application window that is obscured is less than 30% of the original area of the shared application window, the process flows to step 809 , whereat the new display information for the viewer display of the unobscured portion of the shared window is taken from the newly received window information while for the obscured portion of the shared window, the data for painting the corresponding window region on the viewer display is taken from the last prior display data set for painting the shared window on the viewer display wherein that portion of the shared window was not obscured. Once the new display information for the viewer display is created, the process returns to step 801 to await further new window information.
If at step 807 it is determined that the amount of the shared application window that is obscured is greater than 30% of the original area of the shared application window, the process flows to step 811 . At step 811 , the process sets a five-second timer and awaits the receipt of new window information showing the shared window to no longer be obscured by greater than 30%. During the five-second delay, the viewer display is constructed according to the most recent viewer display corresponding to an obscured condition of less than 30% rather than the new window data. If the five-second timer expires without the receipt of such window information, then the process flows to step 813 , whereat the process washes out the current apparently unobscured viewer display, so that the information therein appears as readable but not currently active. The process also preferably places a notification on the screen, such as in a pop-up window, to inform the viewer that the sharing session has been paused. Washing out may be accomplished by using AlphaBlending functionality as in the WINDOWS operating system produced by MICROSOFT of Redmond, Wash. From step 813 , the process returns to step 801 to await new window information. Note that on subsequent re-execution of the logically following steps while the occlusion still exceeds 30%, certain steps are treated differently as appropriate. In particular, since the predetermined delay time has expired already, and the display has been modified accordingly already, if the determination at step 807 is a negative, the process returns to step 801 rather than proceeding to step 811 .
If instead at step 811 , when the five-second timer expires, the most recently received window information indicates that the shared window is stilled obscured, but by less than 30%, then the process flows to step 809 and the steps that logically follow. If at step 811 the most recently received window information when the five-second timer expires indicates that the shared window is no longer obscured, the process returns to step 805 and to execute the steps that logically follow.
With respect to the treatment of window information for purposes of creating the viewer display of a shared window, the following implementation detail variations may be employed, especially if the application sharing session is supported by the WINDOWS operating system. The application sharing program at the viewer machine maintains an off-screen bitmap matched to the sharer's application regions. The application sharing program at the sharer machine sends the application sharing program at the viewer machine a DT_WNDLST packet any time windows are moved or created on the sharer display. The DT_WNDLST packet contains a list of all shared windows and non-shared windows that intersect shared windows on the sharer machine. The list includes information as to the position and shape of each window, as well as an indication of whether the window is shared or not, and the intersections are z-order processed. For example, the lowest z-order window, if shared, is added to the shared region, after which an overlapping non-shared window next in the list may clip the shared region and augment the obscured region. Next, if the following window is shared, it will similarly be used to clip the obscured region and augment the shared region, and so on. The process proceeds in this manner through all windows in the windows list in reverse z-order.
The application sharing program at the viewer machine calculates an obscured region with respect to a displayed shared window from the received data as described above when each new window list arrives. Subsequently, the application sharing program at the viewer machine subtracts from this calculated obscured region for the window any previously calculated obscured region, yielding the newly obscured region over the previous windows information. The newly obscured region is copied to a “paused” bitmap at the viewer for future use in reconstructing the obscured areas of the window. When the viewer subsequently paints the shared window, it utilizes both the off screen bitmap and the paused bitmap, where appropriate in view of the procedure outlined with reference to FIG. 8 , e.g. for minor occlusions.
All of the references cited herein, including patents, patent applications, and publications, are hereby incorporated in their entireties by reference. That is, each and every part of every such reference is considered to be part of this disclosure, and therefore no part of any such reference is excluded by this statement or by any other statement in this disclosure from being a part of this disclosure.
In view of the many possible embodiments to which the principles of this invention may be applied, it should be recognized that the embodiments described herein with respect to the drawing figures are meant to be illustrative only and should not be taken as limiting the scope of invention. For example, those of skill in the art will recognize that the elements of the illustrated embodiment shown in software may be implemented in hardware and vice versa or that the illustrated embodiment can be modified in arrangement and detail without departing from the spirit of the invention. Furthermore, although network connections are illustrated herein as lines, no limitation should thereby be imparted to the invention. Network connections may be circuit-switched, packet-switched, or otherwise, and may be transient or permanent, hard-wired or wireless, operating via any suitable protocol. Also note that although embodiments of the invention have been described largely by reference to a sharing program that is separate from the shared process, the sharing program may not be a stand alone program, but may instead be an integral part of the shared process itself, or may be a DLL or other in-process entity.
Moreover, the exact values of the various time periods and percentages given in the above description are exemplary only, and may be varied without departing from the scope of the invention. Thus, a predetermined delay time usable in the process of FIG. 8 may be two seconds, ten seconds, or any other period, and is not restricted to the period of five seconds used as an example. Furthermore, the dividing line between large and small occlusions should be set to give the best results for a given situation. As such, no limitation is intended in this regard, other than that a mechanism for defining classes of occlusions be provided. Although the foregoing description discusses a bifurcated treatment of classes of occlusions, the number of occlusion classes is not limited to two classes, but may include as many classes as are convenient in each particular implementation. It will understood that although the examples of FIGS. 3 , 6 , 7 , and 8 refer to a sharer and a viewer computer, any number of viewers may be involved, and a viewer may become a sharer and a sharer may become a viewer without limitation. In addition, although the foregoing description gives a number of examples wherein one or more windows obscure another window, no limitation to windows is intended. That is, other types of graphical display objects may obscure and may be obscured, and many of the techniques described herein will be appreciated by those of skill in the art to be applicable to such other objects. Such other graphical objects include but are not limited to non-rectilinear objects such as animated objects rendered on the sharer display.
Furthermore, references herein to application sharing are not meant to require that all windows or material displayed on a sharer display and associated with a particular application are shared or unshared. Rather, one or more windows associated with an application running on the sharer machine are preferably sharable without requiring the sharing of all windows associated with that instance of that application. Moreover, although the steps employed to construct the viewer display of an occluded shared window are discussed herein with reference to the application sharing program of the viewer computer, such steps may alternatively be executed in whole or in part at the sharer computer.
Therefore, the invention as described herein contemplates all such embodiments as may come within the scope of the following claims and equivalents thereof.
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An improved application sharing system and method are described wherein shared window data is treated according to different sets of rules depending upon the fraction of the shared window data that corresponds to the actual shared window. In this manner, occlusions of a shared window on a sharer display may be disguised or handled by a viewer display to minimize the impact of the occlusion on a viewing user, providing a more consistent and less confusing viewer experience.
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NOTICE OF COPYRIGHT
[0001] A portion of the disclosure of this patent document contains material which is subject to copyright protection. The copyright owner has no objection to any reproduction by anyone of the patent disclosure, as it appears in the United States Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever.
BACKGROUND OF THE PRESENT INVENTION
[0002] 1. Field of Invention
[0003] The present invention claims an underground annular blowout preventer, which belongs to the technical field of underground blowout prevention.
[0004] 2. Description of Related Arts
[0005] In the task of oil exploration and oilfield development, well drilling is very important. Looking for and proving oil and gas bearing structures, obtaining industrial oil output, verifying oil and gas bearing areas and reserves of the proved oil and gas bearing structures, obtaining geological data and development data related to the oil field, and extracting the crude oil from underground are all completed through well drilling. Well drilling is a very important part in exploring and exploiting oil and gas resources and an important method of exploring and exploiting oil.
[0006] During the well drilling process, when there is oil-gas reservoir, if the bottom-hole pressure is lower than the formation pressure, the formation fluid will enter the well. If a large amount of formation fluid enters the well, well kick, blowout, or even fire may result and cause a major accident. Therefore, it is important to take effective measures to control the pressure in the oil-gas well during well drilling process. However, it is very hard to predict the pressure of the high-pressure oil and gas layer, especially when drilling in the new blocks. As a result, high pressure oil and gas from the stratum may accidentally enter the well during well drilling process. In addition, well kick and blowout accidents occur in the following three states: during the drilling process, lifting and lowering the drill pipe, and emptying the well. The probability of well kick in an empty well is very low, and the probability of well kick or blowout during process of lifting and lowering the drill pipe can be effectively reduced by controlling the velocity of lifting and lowering the drill pipe to avoid overly large suction forces. Because it is impossible to predict the pressure of a high pressure oil and gas layer during drilling process, the probability of well kick or blowout during this process is the highest.
[0007] When sign of well kick or blowout is discovered, rapidly shutting in and killing the well are highly effective operations in reducing blowout accidents. The traditional well shut-in operation is as follows (soft shut-in is usually used in China): after discovering well kick, shutting down the blowout preventer after opening the throttle valve, such that the water hammering action to the well head equipment and annulus is prevented; however, the amount of stratum fluid that entered will be relatively large because the time for well shut-in is long. The extra stratum fluid can cause additional pressure to the well head equipment and stratum, which makes well killing more difficult.
[0008] Presently, most blowout preventers used for the well drilling process are mounted at the well head. During the well drilling process, an arrow-shaped check valve is mounted on the drill pipe near the drill to avoid a reflux of fluid inside the drill pipe. The blowout preventer at well head is usually used to seal the annulus during drilling process and only used for well sealing when it is necessary to cut the drill pipe. When a sign of well kick is discovered, the operator turns on the control system to finish the well shut-in operation so as to avoid a blowout accident. This kind of operation relies on the experience and responsibility of the operator. However, if the operator lacks of the experience or is negligent during work, the sign of well kick or blowout may not be discovered in time, and a major accident may occur. After a well shut-in operation, the time required for well killing a well with heavy mud on the traditional well head blowout preventer is long, which results in more bottom fluid entering the well and increases the annular pressure difference, and thus it is more difficult to control blowout. Therefore, if an underground annular blowout preventer can be invented and lowered into the well together with the drill pipe, when the sign of underground well kick or blowout is discovered from the ground, the operator can operate the underground annular blowout preventer to seal the annulus and the check valve near the drill which can effectively seal the inner side of drill pipe. Thus the inner side of drill pipe and annulus over the annular preventer are in communication with each other after sealing, which facilitates the subsequent well killing operation with heavy mud. By using a check valve near the drill and an early-phase well kick pre-warning system together with the underground annular sealer, the well control principle of early-discovery and early-treatment can be realized. This operation is easier to be executed than the common well control operations.
[0009] The Chinese invention patent application which was published on 23 Jun. 2010 and named as A well blowout preventer mounted in a drilling column and automatically controlled in a well, with application number of 200910263415.7 and publication number of CN101748984A, discloses an underground preventer which can prevent blowout during well kick to a certain extent. However, it has a complex structure and many components; therefore, it is complex to install, replace, and has an accordingly high cost. After being used to prevent a blowout, the preventer can be recovered and reused from the original structure through the spring when there is no pressure difference, but if there is a pressure difference inside and outside the preventer, the preventer most likely cannot be recovered for reuse because elastic force of the spring is less than the pressure difference. After being used multiple times, the spring can easily be broken; if the spring is broken when the blowout preventer is in use, the blowout preventer cannot be recovered and taken out, and thus the blocking caused thereby brings large inconveniences to the subsequent operations.
[0010] The Chinese invention patent application which was published on 23 Aug. 2010 and named as A mechanical underground all-in-one blowout preventer, with application number of 201010148874.3 and publication number of CN101812981A, discloses an underground all-in-one blowout preventer which can prevent a blowout during well kick to a certain extent. However, it has a complex structure and uses a shearing pin to seal; the pin is used to connect the upper and lower drilling tool and transfer the torque in the well drilling process, but the pin can be broken after undertaking long periods of variable shearing forces and variable torque because the drill pipe vibrates in drilling process. Therefore, the reliability of the blowout preventer is not high since it is easy to cause an incorrect operation and due to an unexpected pin break a series of underground accidents can occur. Moreover, when it is necessary to seal the high drilling pressure, the lower drill is required to cut the pin. However, the lower drill components can only sustain a certain drilling pressure, which means that the process of cutting the pin can easily damage the lower drill components and cause an underground accident. The invention patent application has one more problem. Even if all the operations before sealing the annulus are normal, if the annulus sealing is not complete, the high pressure stratum oil and gas inside the annulus can enter the drill pipe through the flow guiding hole, which makes the arrow-shaped check valve fail to seal the inner side of the drill and makes the well control more difficult. Furthermore, after the pin is cut, well drilling has to be stopped and it is mandatory to take out the drill pipe and replace or maintain the all-in-one blowout preventer; that is, the blowout preventer can only be used once after being lowered to the well, which is unfavorable for reuse.
[0011] The Chinese invention patent application which was published on 2 Feb. 2010 and named as A lifting valve type underground inside-outside integrated blowout preventer, with application number of 200910312467.9 and publication number of CN101718181A, discloses an underground all-in-one blowout preventer which can prevent a blowout during a well kick to a certain extent. However, it has a complex structure and needs to be driven by a motor. Some problems with this invention are that it is difficult to install the motor, and a high capacity power source is required in the narrow underground space. There is doubt that whether the power provided by the motor can meet the minimum power requirements required by the sealing and unsealing processes (especially when the pressure difference is high). Therefore, the safety and reliability of the patent are not high, and it is not very practical to be used in actual well drilling.
SUMMARY OF THE PRESENT INVENTION
[0012] The invention is advantageous in that it provides
[0013] Another advantage of the invention is to provide an underground annular blowout preventer that is simple in structure, innovative in design, and high in reliability.
[0014] Another advantage of the invention is to provide an underground annular blowout preventer that can be used together with an overflow and well kick pre-warning system and a check valve near the drill, wherein when the signal of underground well kick and blowout is received from the ground, the drill rod is lowered to increase drilling pressure to a specific level, so as to seal the well quickly and realize a communication between the inner side of the drill pipe and the annulus. The pipe column is then lifted to unseal the well.
[0015] Another advantage of the invention is to provide an underground annular blowout preventer is that the present invention can effectively prevent blowout accidents, and it has high feasibility, based on the following steps:
[0016] (1) In the underground annular blowout preventer of the present invention, the torque transference between the upper and lower drill pipe is realized by the spline pair between the upper joint and the lower joint of the annular blowout preventer, so it can sustain a large torque. Each component of the blowout preventer is capable in handling a reasonable stress and is high in reliability.
[0017] (2) The underground annular blowout preventer of the present invention can be mounted into a well at different depth over the demarcation point of drill pipe, and can allow multiple realization of sealing and unsealing of the drill without need of taking out the drill pipe to replace the blowout preventer. This helps to reduce cost of the equipment and the entire well drilling process due to the reusability.
[0018] (3) Because of the first and second check valves, the underground annular blowout preventer of the present invention can prevent the high pressure fluid in the annulus from entering the drill pipe when the annular seal loses effectiveness due to other reasons.
[0019] (4) The underground annular blowout preventer of the present invention provides sealing at peripheries of the first and the second flow guiding holes with sealing member, so as to ensure that inner side of the drill pipe will not be in communication with the annulus during normal drilling process. Due to the first and second check valves, solid impurities in mud cannot damage the sealing layer and the sealing member; therefore, the service life of the sealing members is prolonged.
[0020] (5) During the well sealing process, the drill pipe can be lifted properly and lowered quickly, wherein the drill pipe is re-lowered after the drill is lifted from the bottom of well in short time, so as to seal the annular blowout preventer, and thus prevent the drill from being blocked.
[0021] (6) During the well sealing process, it is only necessary to increase drilling pressure to make the spring ejector slide into the lower moving groove from the upper moving groove, and the increased drilling pressure can be controlled within the maximum drilling pressure limit so that the lower drilling tool can be sustained, such that the lower drilling tool of the drill pipe can be protected as much as possible during the process of sealing annulus.
[0022] (7) The assembly technique of the underground annular blowout preventer of the present invention is unique in design and innovative in technique. By using the assembly technique, the sealing effect of the blowout preventer can be guaranteed. Quick sealing and unsealing are realized due to the innovative operation; furthermore, a stable and reliable structure, and a long service life of the blowout preventer are guaranteed.
[0023] Additional advantages and features of the invention will become apparent from the description which follows, and may be realized by means of the instrumentalities and combinations particular point out in the appended claims.
[0024] According to the present invention, the foregoing and other objects and advantages are attained by an underground annular blowout preventer and assembly process thereof.
[0025] In accordance with another aspect of the invention, the present invention comprises an underground annular blowout preventer, comprising an upper joint, a lower joint, a central barrel, and a rubber barrel, wherein the upper joint and the lower joint are sleeved outside a central barrel, wherein the lower end of the central barrel is fixedly connected with the lower joint, wherein the lower end of the upper joint is sleeved on the inner side of the upper end of the lower joint, wherein the upper joint is matched with the lower joint through a spline, wherein the lower end of the upper joint can move freely relative to the lower joint along the spline pair, wherein at least one rubber barrel is sleeved on the outer side of the upper joint, wherein the rubber barrel can be extruded and expanded by the upper joint and the lower joint.
[0026] Because of adopting the above structure, the upper joint is matched with the lower joint through a spline, the lower joint can rotate at the same time along with the upper joint, such that the underground annular blowout preventer of the present invention can transfer torque when it is not necessary to be used as annular blowout preventer; the lower end of the upper joint can move freely relative to the lower joint along the spline pair, so the pipe column can be lowered to move the upper joint downwards to seal the well, so as to prevent well kick or blowout. Since the lower end of the central barrel is fixedly connected with the lower joint, when the upper joint moves downwards, the rubber barrel is extruded and expanded by the upper joint and the lower joint, and thus the annulus between the drill pipe and well wall or drill pipe and the casing pipe is sealed to effectively prevent a well kick or blowout. The underground annular blowout preventer of the present invention is used with the drill, and it can realize the sealing and unsealing operation multiple times. Weight indicators can be used to monitor whether the sealing or unsealing operations are successful from the ground making it unnecessary to take out the drill pipe to replace the blowout preventer; and thus the blowout preventer can be used for multiple times, has a long service life, and a reduced cost.
[0027] A first flow guiding hole is set on the central barrel and a second flow guiding hole is set on the upper joint, wherein a sealing member is set between inner wall of the upper joint and outer wall of the central barrel, wherein the periphery of the first flow guiding hole and the periphery of the second flow guiding hole are sealed by the sealing member, such that the first flow guiding hole and the second flow guiding hole can be in butt joint with each other when the upper joint moves downwards.
[0028] Because of adopting the above structure, a sealing structure is formed at the periphery of the first flow guiding hole and the periphery of the second flow guiding hole, so as to seal the inner side of the drill pipe and the annulus. When the blowout preventer acts to transfer moment to force, the first flow guiding hole and the second flow guiding hole are both sealed by the check valve so as to prevent liquid-solid impurities from polluting the sealing surface. During the process of the upper joint moving downwards, the second flow guiding hole on the upper joint forms a butt joint with the first flow guiding hole on the central barrel, and the check valve can be opened due to the pressure difference because the periphery of the flow guiding hole is sealed, so that the drilling fluid inside the central barrel enters the annulus, which provides passage for the subsequent replacement for heavy mud lubrication operations. The blowout preventer in the drill pipe can prevent the mud from returning inside the drill pipe, and seal inner side space of the drill pipe and annulus at the same time together with the underground annular blowout preventer, so as to control occurrence of blowout and eliminate the risk.
[0029] A first check valve is set in the first flow guiding hole, and/or a second check valve is set in the second flow guiding hole.
[0030] Because of adopting the above structure, the check valve is used to prevent the drilling fluid in the annulus from entering the drill pipe when the annular seal loses effectiveness, and when the flow guiding holes are in butt joint with each other. The check valve can be opened by the fluid pressure so as to connect the inner space of the drill pipe and the annulus, and provide passage for the subsequent replacement for heavy mud lubrication operations. The check valve can also prevent solid impurities in the drilling fluid from entering the sealing layer during the normal drilling process, so as to prolong the service life of the sealing member.
[0031] A spring ejector is set on the inner side of the upper end of the upper joint, and the outer side of the central barrel close to the upper joint is provided with multiple moving grooves. When there are three moving grooves; the upper moving groove, middle moving groove, and lower moving groove from top down in order and are matched with the spring ejector; the ejector on the spring ejector can slide among the moving grooves.
[0032] Because of adopting the above structure, the ejector at the front end of the spring ejector can slide among the moving grooves. When the ejector is sliding among the moving grooves, the counteractive force from the moving groove to the ejector will be transferred to the upper drill pipe. Because the counteractive force to the ejector changes when it goes into or out of the moving grooves, the support force from the moving grooves to the upper drill pipe also changes, which results in a momentary jumping of the index of the weight indicator in the control room. By cooperation of the ejector and the moving grooves, the upward and downward movement of the upper external sleeve can be located, so as to realize effective sealing and unsealing to control well kick and blowout. By observing index change of the weight indicator on the ground, the sealing and unsealing states can be judged.
[0033] The upper joint can be made by fixedly connecting an upper joint component with an internal sleeve, or by fixedly connecting an upper connector component, an upper external sleeve, and an internal sleeve.
[0034] Because of adopting the above structure, the upper joint can be an integrated upper joint and can also be made of multiple components by fixed connections. The present invention provides multiple structural choices for the blowout preventer, with operability and multiple choices. Specific upper joint structures can be chosen according to actual requirements so as to lower production cost, reduce assembly step, and facilitate the subsequent maintenance, etc.
[0035] The spring ejector is set inside the upper joint component, and the second flow guiding hole is set on the upper joint component, wherein the lower end of the inner sleeve is sleeved on inner side of the upper end of the lower joint and the inner sleeve is in clearance fit with the lower joint through a spline, wherein the lower end of the inner sleeve can move freely relative to the lower joint along the spline pair, and the rubber barrel is sleeved outside of the inner sleeve and can be extruded and expanded by the upper joint component and the lower joint.
[0036] Because of adopting the above structure, the upper joint formed by the upper joint component and the inner sleeve makes each component of the blowout preventer able to be disassembled and assembled through matching with the lower joint and the central barrel. Thus it is very convenient to assemble, disassemble, and replace the blowout preventer, which guarantees convenient use of the preventer. The specific structure can be chosen according to actual requirement. The present invention is suitable for widespread usage.
[0037] The spring ejector is set inside the upper connector, and the second flow guiding hole is set on the upper connector, wherein the lower end of the inner sleeve is sleeved on inner side of the upper end of the lower joint, wherein the inner sleeve is in clearance fit with the lower joint through a spline, wherein the lower end of the inner sleeve can move freely relative to the lower joint along the spline pair, and the rubber barrel is sleeved outside of the inner sleeve and can be extruded and expanded by the upper connector and the lower joint.
[0038] Because of adopting the above structure, the upper joint formed by the upper connector, inner sleeve, and the outer sleeve makes each component of the blowout preventer able to be disassembled and assembled through matching with the lower joint and the central barrel. Thus it is very convenient to assemble, disassemble, and replace the blowout preventer. The cost of producing, using, and maintaining the annular blowout preventer is reduced as much as possible, and the specific structure can be chosen according to actual requirement. The present invention is suitable for widespread usage.
[0039] A convex shoulder is set outside of the central barrel, and the convex shoulder can be integrated with the central barrel, or the central barrel can be sleeved by a support sleeve and fixed outside the central barrel, wherein the support sleeve is an integrated structure or multiple pieces which are spliced together.
[0040] Because of adopting the above structure, the convex shoulder outside of the central barrel can be an integrated structure or the convex shoulder can be sleeved by the support sleeve and fixedly connected to outside of the central sleeve, wherein the present invention provides multiple structural choices for the central barrel, so as to facilitate convenient assembly according to actual requirement. The support sleeve can be integrated or spliced together with multiple pieces according to actual requirement, which is suitable for assembling of each blowout preventer structure for easy operation.
[0041] A thrust bearing is sleeved outside of the central barrel, and the thrust bearing is between the convex shoulder outside of the central barrel and the upper end surface of the inner sleeve, or the thrust bearing is between the support sleeve and the upper end face of inner sleeve.
[0042] Because of adopting the above structure, the direct friction caused by relative rotation between the central barrel and the upper external sleeve can be avoided through the thrust bearing. This relative friction is caused by the relative motion due to lack of processing precision of spline pair; however, if the underground working condition is poor, the clearance between the spline pair can be enlarged after a long period of working, so it is necessary to mount the thrust bearing which makes relative motion between the central barrel and the internal sleeve smoother, so as to reduce the torque transference between the central barrel and the internal sleeve, and to avoid reverse buckling between the central barrel and the lower external sleeve caused by spline clearance and the possible problem of the rotating velocity of the lower drill is faster than that of the upper drill.
[0043] The inner wall of the central barrel is provided with installation auxiliary hole.
[0044] Because of adopting the above structure, the installation of the auxiliary hole facilitates mounting, maintenance, and replacement of the underground annular blowout preventer of the present invention, such that it is convenient and quick to mount and maintain the blowout preventer.
[0045] The lower joint mainly comprises of a lower connector and a lower external sleeve which are fixedly connected with each other, wherein the spline inside the lower joint is located inside the lower external sleeve which is fixedly connected to lower end of the central barrel.
[0046] Because of adopting the above structure, the lower end of the lower joint is used for connecting with the drill pipe, wherein the thread on the lower end of the lower joint can be easily broken when in, use making it necessary to replace the lower joint often; however, the spline is set inside the lower joint, and it needs a high cost to process the spline inside of the lower joint. If the lower joint is divided into two parts, including the lower connector and the lower external sleeve which are fixedly connected with each other through the API drill pipe by means of threads or connected with each other through common threads, pins, and sealing members, so that the structure is stable in use. The spline is set inside of the lower external sleeve and the thread connected with the drill pipe is set on the lower connector, wherein when the thread connected with the drill pipe is broken, it is only necessary to replace the lower connector part without need for taking off the lower external sleeve and replacing the spline part, thus the maintenance cost is greatly reduced.
[0047] An assembly technique of an underground annular blowout preventer, comprising the following steps:
[0048] 1201 , fixing the inner sleeve, embedding multiple spacer rings and the rubber barrel outside of the inner sleeve along the thread direction at the upper end of the inner sleeve, such that the spacer rings and the rubber barrel are limited over the spline outside the internal sleeve;
[0049] 1202 , embedding the thrust bearing inside the upper external sleeve from the lower end thereof, and tightening the lower end of the upper external sleeve and the upper end of the inner sleeve to the predetermined torque after butt jointed with each other;
[0050] 1203 , embedding the first check valve and the second check valve separately on the side walls of the central barrel and the upper external sleeve, and tightening to the predetermined torque, embedding the sealing member to the relevant position of the central barrel while preventing the sealing member from being scratched when passing through the central barrel, and mounting the central barrel from top of the upper external sleeve and the inner sleeve;
[0051] 1204 , embedding the lower joint to the outside of the central barrel and the inner sleeve along the spline pair, stretching the outward expanding tool to inner side of the central barrel and blocking the tool into the installation auxiliary hole, fixing the lower joint while rotating the central barrel, or fixing the central barrel while rotating the lower joint so as to tighten the thread pair between lower end of the central barrel and the lower joint to the predetermined torque;
[0052] 1205 , embedding the spring ejector inside the upper connector, inserting the upper connector into the central barrel along the outer wall thereof, fixing the upper external sleeve while rotating the upper connector, or fixing the upper connector while rotating the upper external sleeve so as to tighten the thread pair between the upper connector and the upper external sleeve to the predetermined torque, such that the ejector on the spring ejector slides into the upper moving groove of the central barrel during the downward movement process of the upper connector.
[0053] Because of adopting the above structure, the blowout preventer can be assembled quickly. When the accessories are broken, they can be replaced by reverse disassembling. The assembling technique is innovative in that the blowout preventer assembled by this technique is stable and reliable in structure and can effectively prevent well kick and blowout. The assembling technique of the blowout preventer is unique in design and innovative in technique; it can guarantee a good sealing effect and the assembled blowout prevent has an innovative operation able to quickly realize sealing and unsealing. It is stable and reliable in structure and has a long service life.
[0054] An assembly technique of an underground annular blowout preventer, comprising the following steps:
[0055] 1301 , fixing the inner sleeve, embedding multiple spacer rings and the rubber barrel outside of the inner sleeve along the thread direction on the upper end of the inner sleeve, such that the spacer rings and the rubber barrel are limited above the convex shoulder at the middle of the inner sleeve;
[0056] 1302 , mounting the first check valve on the support sleeve and embedding the spring ejector to the inner wall of the upper joint component, embedding the support sleeve inside the upper joint component from the lower end thereof and embedding the thrust bearing inside the upper joint component from the lower end thereof, and fixedly connecting the lower end of the upper joint component and the upper end of the inner sleeve;
[0057] 1303 , embedding the central barrel body into the inner sleeve from the lower end thereof and passing through the support sleeve, and fixedly connecting the central barrel body with the support sleeve;
[0058] 1304 , embedding the lower joint into the central barrel body along the lower end of the central barrel body and the external spline end of the internal sleeve, stretching the outward expanding tool to inner side of the central barrel body and blocking the tool into the installation auxiliary hole, fixing the lower joint while rotating the central barrel body, or fixing the central barrel body while rotating the lower joint, so as to tighten the thread pair between the central barrel body and the lower joint to the predetermined torque, such that the ejector on the spring ejector slides into the upper moving groove of the central barrel body during the downward movement process of the upper joint component.
[0059] Because of adopting the above structure, the blowout preventer can be assembled quickly when the accessories are broken, and they can be replaced by reverse disassembling. The assembling technique is innovative, and the blowout preventer assembled by this technique is stable and reliable in structure and can effectively prevent well kick and blowout. Additionally, the assembling technique of the blowout preventer is unique in design and innovative in technique, it can guarantee a good sealing effect and the innovative action of the assembled blowout preventer allows for quick realization in sealing and unsealing. It is stable and reliable in structure, and has a long service life.
[0060] An assembly technique of an underground annular blowout preventer, comprising the following steps:
[0061] 1401 , embedding the first check valve into the first flow guiding hole on the support sleeve which is made by splicing multiple pieces, embedding the thrust bearing which is made by splicing multiple pieces into the cavity of the upper joint and embedding the support sleeve into the cavity of the upper joint over the thrust bearing;
[0062] 1402 , embedding the spring ejector into the inner wall of the upper end of the upper joint, sleeving the rubber sleeve and the spacer ring in order on the middle part outside the upper joint, embedding the central barrel body into the upper joint from the lower end thereof and passing through the support sleeve, fixedly connecting the central barrel body and the support sleeve, embedding the second check valve into the second flow guiding hole on the upper joint;
[0063] 1403 , embedding the lower joint along the external spline end at the lower end of the central barrel body and the lower end of the upper joint, stretching the outward expanding tool to inner side of the central barrel body and blocking the tool into the installation auxiliary hole, fixing the lower joint while rotating the central barrel body, or fixing the central barrel body while rotating the lower joint, so as to tighten the thread pair between lower end of the central barrel body and the lower joint to the predetermined torque, such that the ejector on the spring ejector slides into the upper moving groove of the central barrel body during the downward movement process of the upper joint.
[0064] Because of adopting the above structure, the blowout preventer can be quickly assembled when the accessories are broken, and they can be replaced by reverse disassembling. The assembling technique is innovative, the blowout preventer assembled by this technique is stable and reliable in structure, and can effectively prevent well kick and blowout. The assembling technique of the blowout preventer is unique in design and innovative in technique in that it can guarantee a good sealing effect and an innovative operation of the assembled blowout preventer in quickly realizing the sealing and unsealing. It is stable and reliable in structure and has a long service life.
[0065] Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.
[0066] These and other objectives, features, and advantages of the present invention will become apparent from the following detailed description, the accompanying drawings, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] FIG. 1 is a structural schematic diagram of embodiment 1 of the underground annular blowout preventer of the present invention.
[0068] FIG. 2 is A-A view of FIG. 1 .
[0069] FIG. 3 is B-B view of FIG. 1 .
[0070] FIG. 4 is partial enlarged drawing of the Part I in FIG. 1 .
[0071] FIG. 5 is structural schematic diagram of the drill pipe equipped with the underground annular blowout preventer of the present invention.
[0072] FIG. 6 is structural schematic diagram of the embodiment 3 of the underground annular blowout preventer of the present invention.
[0073] FIG. 7 is another structural schematic diagram of the embodiment 1 of the underground annular blowout preventer of the present invention.
[0074] FIG. 8 is structural schematic diagram of the embodiment 2 of the underground annular blowout preventer of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0075] The following description is disclosed to enable any person skilled in the art to make and use the present invention. Preferred embodiments are provided in the following description only as examples and modifications will be apparent to those skilled in the art. The general principles defined in the following description would be applied to other embodiments, alternatives, modifications, equivalents, and applications without departing from the spirit and scope of the present invention.
[0076] All features, methods, or steps published in the specification, except the features and/or steps which are repellent to each other, can be combined for use in any way.
[0077] The specification includes all features published in any additional claims, abstracts and drawings; unless described specially, all features can be replaced by other substitutable features which have equivalent effect or similar target. That is, unless described specially, each feature is only one example of the series of equivalent or similar features.
[0078] Embodiment 1
[0079] The embodiment of the underground annular blowout preventer claimed in the present invention, as illustrated in FIGS. 1 , 2 , 3 and 4 , comprises an upper connector 1 - 1 and a lower joint 10 which are sleeved outside of the central barrel 3 , wherein the lower end of the central barrel 3 is fixedly connected with the lower joint 10 through API drill pipe by means of threading or connected with each other through common threading, pin, and sealing member, wherein a spring ejector 2 is set on the inner side of the upper connector 1 - 1 , and the upper end of the central barrel 3 is provided with three moving grooves including upper moving groove 11 - 1 , middle moving groove 11 - 2 and lower moving groove 11 - 3 , wherein the moving grooves are used to match with the spring ejector 2 , and more grooves can be set according to actual requirement, wherein while in use, every time the annular blowout preventer enters one state (lowering to seal or lifting to unseal), components like the upper connector 1 - 1 should also be lowered or lifted along with the upper connector 1 - 1 , and the ejector at the front end of the spring ejector 2 slides among the upper moving groove 11 - 1 , the middle moving groove 11 - 2 , and the lower moving groove 11 - 3 , wherein every time when the ejector slides into or out of the moving grooves, the index of the weight indicator on the ground will fluctuate, which provides a signal feedback of the annular blowout preventer status for the control personnel on the ground to control, wherein when using the sealing function of the annular blowout preventer, the drill is lowered and the upper connector 1 - 1 moves downwards, while the spring ejector 2 moves from the upper moving groove 11 - 1 to the middle moving groove 11 - 2 , the index of the weight indicator fluctuates (it becomes smaller and then bigger), wherein because the middle moving groove 11 - 2 is wider, the ejector of the spring ejector 2 slides to the lower end of the middle moving groove 11 - 2 when the upper connector 1 - 1 moves downwards, wherein during the long displacement, the index of weight indicator barely changes, wherein when the upper connector 1 - 1 moves downwards continuously, ejector of the spring ejector 2 slides to the lower moving groove 11 - 3 from the middle moving groove 11 - 2 , and the index of the weight indicator fluctuates again (it becomes smaller and then bigger) and becomes stable, which means the preventer sealed successfully; there are multiple match methods for the moving grooves and the spring ejector, for example, round groove matching with spherical ejector, V-shaped groove matching with trapezoidal ejector, rectangular groove matching with trapezoidal ejector and so on. Both ends of the three moving grooves are provided with sealing member 4 which is between the upper connector 1 - 1 and the central barrel 3 , so as to seal the moving grooves inside to prevent solid impurities in mud from polluting the lubricating environment of the moving groove and to prevent the stressing effect from being changed. There are two or more spring ejectors uniformly distributed along the outer wall of the central barrel 3 , so as to ensure uniform stressing on the part between the central barrel 3 and the upper connector 1 - 1 , and avoid eccentric problems caused by downward movement of the upper connector 1 - 1 . The upper external sleeve 1 - 2 is fixedly connected to the lower end of the upper connector 1 - 1 through API drill pipe by means of threading or through a common threading, pin, and sealing member, wherein during well drilling process, the lower end of the central barrel 3 will be tightened more and more with the lower joint 10 , so as to ensure safety and to prevent reverse buckling. Alternatively, the upper external sleeve 1 - 2 can be integrated with the upper connector 1 - 1 to ensure convenient use, stable structure, and using safety. The upper external sleeve 1 - 2 is sleeved outside of the central barrel 3 , and a second flow guiding hole 5 - 2 is set on the upper external sleeve 1 - 2 , while a first flow guiding hole 5 - 1 is set on the relevant position on the central barrel 3 . A second check valve 6 - 2 is set in the second flow guiding hole 5 - 2 , and a first check valve 6 - 1 is set in the first flow guiding hole 5 - 1 . When the upper external sleeve 1 - 2 moves downwards, the second flow guiding hole 5 - 2 can be butt jointed with the first flow guiding hole 5 - 1 . Sealing members 4 are set over and below both flow guiding holes, so as to seal the peripheries of the first flow guiding hole 5 - 1 and the second flow guiding hole 5 - 2 . Because the check valve can obstruct solid impurities in the drilling fluid, the sealing layer and sealing member between the upper external sleeve 1 - 2 and the central barrel 3 are protected from being damaged by the solid impurities in the drilling fluid during normal drilling process, so as to guarantee sealing effect and service life. The lower end of the upper external sleeve 1 - 2 is provided with the inner sleeve 1 - 3 inside by means of a fixed connection through the API drill pipe joint threading or through a common thread, pin, and sealing member. The inner sleeve 1 - 3 is sleeved outside of the central barrel 3 , and a first spacer ring 8 - 1 , a first rubber barrel 9 - 1 , a second spacer ring 8 - 2 , a second rubber barrel 9 - 2 , a third spacer ring 8 - 3 , a third rubber barrel 9 - 3 , and a fourth spacer ring 8 - 4 are sleeved outside of the central barrel 3 to form a rubber component. Both ends of the rubber barrel component are respectively in contact with lower end face of the upper external sleeve 1 - 2 and upper end face of the lower joint 10 , wherein the lower end of inner sleeve 1 - 3 is sleeved between the lower joint 10 and the central barrel 3 , and lower end of inner sleeve 1 - 3 is matched with the middle part of inner wall of the lower joint 10 through a spline (as shown in FIG. 3 ), such that lower end of inner sleeve 1 - 3 can move up and down freely relative to the lower joint 10 and the central barrel 3 along the spline within a certain displacement range, wherein only in this way can the relative distance between the upper external sleeve 1 - 2 and the lower joint 10 can be reduced, so as to keep enough space for rubber barrel to expand after being pressed or rebounded so that the rubber barrel can seal and unseal the annulus. During the normal drilling process, the torque transferred from the upper connector 1 - 1 can be transferred to the lower joint 10 and lower drill through the spline pair, such that the drill can be driven to rotate. One or more rubber barrel components can be formed by the rubber barrel and each rubber barrel combination, with a length and number thereof being determined according to actual requirement. Sealing members 4 are set between the inner sleeve 1 - 3 and the central barrel 3 , and the inner sleeve 1 - 3 and the lower joint 10 ; because the lower joint 10 is provided with a spline which requires a high processing cost, and the threading of the lower end of the lower joint 10 , which is used to connect drill pipe, can be easily damaged. This cost is increased if the lower joint 10 is replaced because the threading is damaged; therefore, the lower joint 10 can be divided into the lower connector 10 - 1 and the lower external sleeve 10 - 2 which are fixedly connected with each other through the API drill pipe by means of threading or connected with each other through a common thread, pin, and sealing member. When the thread connected with the drill pipe is broken, it is only necessary to disassemble and replace the lower connector 10 - 1 , and thus the maintenance cost is greatly reduced. To facilitate installation of the annular blowout preventer, the installation auxiliary hole is provided on the inner wall of the central barrel 3 so that a special tool can be inserted into the central barrel 3 to tighten the central barrel 3 and the lower joint 10 by fixing or rotating the central barrel 3 . Through the thrust bearing 7 , relative rotation between the central barrel 3 and the upper external sleeve 1 - 2 can be avoided. Although the relative motion is caused by the relative motion due to the lack of processing precision of the spline pair and poor underground working conditions, the clearance between the spline pair can be enlarged after long-term operation. It is necessary to mount the thrust bearing 7 between the convex shoulder of the central barrel 3 and the upper end of the inner sleeve 1 - 3 , so as to make the relative motion between the central barrel 3 and the internal sleeve 1 - 3 smoother, reduce the torque transference between the central barrel 3 and the internal sleeve 1 - 3 , and avoid reverse buckling between the central barrel 3 and the lower external sleeve 10 - 2 caused by spline clearance and the possible problem that the rotating velocity of the lower drill is faster than that of the upper drill. A step is provided at outside of the upper end of the central barrel 3 , and there is stroke space between the step and end face of the upper connector 1 - 1 ; the inner side of upper end of the lower joint 10 is step-shaped so that the inner sleeve 1 - 3 can be set inside the lower joint 10 , and there is stroke space between the end face of the inner sleeve 1 - 3 and the step inside the lower joint 10 . The distance between each stroke space is equal to the distance between the first flow guiding hole 5 - 1 and the second flow guiding hole 5 - 2 , such that the annular blowout preventer of the present invention is compact in structure. The step can be sleeved by the support sleeve 12 and fixedly connected outside the central barrel 3 .
[0080] The drill column of the present invention is installed with the underground annular blowout preventer, wherein the blowout preventer is mounted to the drill column at the position above the neutral point of the drill column which is in the sleeve or well wall. The drill 13 is at the bottommost end of the drill column, and the two pressure detecting and signal generators, namely the first pressure detecting and signal generator and the second pressure detecting and signal generator, are set above the frill. The drill collar 15 is set above the two pressure detecting devices, and a blowout preventer inside drill column 16 is set above the drill collar 15 . The underground annular blowout preventer of the present invention is mounted at the position above the neutral point of the drill column which is above the drill collar 15 , because the neutral point is the tensioned and distressed demarcation point of drill column and the annular blowout preventer is set above the neutral point, the annular blowout preventer is in a distressed state during the normal well drilling process; that is, the upper connector 1 - 1 , the upper external sleeve 1 - 2 , and the inner sleeve 1 - 3 are all in the distressed state, and the upper external sleeve 1 - 2 and the lower joint 10 have not been extruded in the rubber barrel. Because the lower end of the inner sleeve is matched with the lower joint 10 through the spline, the drill column on the upper end of the blowout preventer can transfer the torque to lower end of the drill column through the spline; therefore, the underground annular blowout preventer of the present invention can effectively prevent well kick or blowout. When the blowout preventer is not being used to seal the well, it can be used to transfer torque. The underground annular blowout preventer of the present invention is lowered to seal and lifted to unseal, so the present invention is suitable for reuse. There is kelly bar (driven by rotary disk) or drill column (top drive) on top of the drill column, and a signal receiver 21 is set on the upper end of the kelly bar or the lower end of the drill pipe. The signal receiver 21 is wirelessly connected with an alarm, and is matched with the pressure detecting device near the drill to send and receive signals separately; the signal can be sound waves, electromagnetic waves, optical waves, and so on.
[0081] The assembly technique of the underground annular blowout preventer of the present invention comprises the following steps:
[0082] a.) fixing the inner sleeve 1 - 3 , embedding multiple spacer rings and the rubber barrel outside of the inner sleeve 1 - 3 along the thread direction of the inner sleeve 1 - 3 , such that the spacer rings and the rubber barrel are limited over the embossment or the step (namely, over the spline) outside the internal sleeve 1 - 3 ;
[0083] b.) embedding the thrust bearing 7 inside the upper external sleeve 1 - 2 from the lower end thereof, and tightening the lower end of the upper external sleeve 1 - 2 and the upper end of the inner sleeve 1 - 3 to the preset torque after butt jointed with each other;
[0084] c.) embedding the check valve 6 to the side wall of the central barrel, tightening to the predetermined torque, embedding the sealing member 4 to the predetermined position of the central barrel 3 while preventing the sealing member 4 from being scratched when passing through the central barrel 3 , and mounting the central barrel 3 from top of the upper external sleeve 1 - 2 and the inner sleeve 1 - 3 ;
[0085] d.) embedding the lower joint 10 to outside of the central barrel 3 and the inner sleeve 1 - 3 along the spline pair of the inner sleeve 1 - 3 , stretching the outward expanding tool to inner side of the central barrel 3 and blocking the tool into the installation auxiliary hole which is preset in the central barrel 3 , fixing the lower joint 10 while rotating the central barrel 3 , or fixing the central barrel 3 while rotating the lower joint 10 so as to tighten the thread pair between lower end of the central barrel and the lower joint to the predetermined torque, stretching the outward expanding tool to inner side of the central barrel 3 and blocking the tool into the installation auxiliary hole which is preset in the central barrel 3 , screwing the part without the spline to thread pair of the central barrel 3 , and tightening to the predetermined torque; if common thread is used, mounting a sealing member in addition and further using a pin to fix them after tightening the thread to the predetermined torque; if a common thread is used, mounting a sealing member in addition and further using a pin to fix them after tightening the thread to the predetermined torque; if a separate lower joint 10 is used, embedding the part of lower joint 10 with spline to outer side of the central barrel 3 and inner sleeve 1 - 3 along the spline pair of the inner sleeve 1 - 3 ;
[0086] e.) embedding the spring ejector 2 inside the upper connector 1 - 1 , inserting the upper connector 1 - 1 into the central barrel 3 along the outer wall thereof, the ejector at front of the spring ejector 2 is pressed into the relevant position of the upper connector 1 - 1 by the outer wall of the central barrel 3 when the upper connector 1 - 1 is moving downwards, when the lower end of the upper connector 1 - 1 is in contact with the upper end of the external sleeve 1 - 2 , rotating the central barrel 3 or the upper connector 1 - 1 so as to tighten the upper connector 1 - 1 and the upper external sleeve 1 - 2 to the predetermined torque;
[0087] f.) mounting the assembled blowout preventer to the drill column at the position above neutral point thereof.
[0088] During the well drilling process, when there is a high pressure oil reservoir or oil reservoir, the working method of the drill column assembled with the underground annular blowout preventer of the present invention comprises the following steps:
[0089] 1.) The first pressure detecting and signal generator 14 - 1 and/or the second pressure detecting and signal generator 14 - 2 detect/detects the underground pressure signal, and compare/compares the signal with the preset program; when the pressure signal indicates abnormal pressure, the signal triggering device on the first pressure detecting and signal generator 14 - 1 and/or the second pressure detecting and signal generator 14 - 2 is switched on and sends an abnormal pressure signal (the signal can be a sound wave, an electromagnetic wave, an optical wave and so on); the signal is then transmitted upwards along the drill pipe, and the signal receiver 21 mounted on the upper end of the kelly bar or on the lower end of top drive receives the signal and sends a warning signal to the alarm, and the alarm sends out warning sound;
[0090] 2.) when the alarm sounds, the drill column is lowered manually or automatically, so the drilling pressure is increased, and the upper connector 1 - 1 , upper external sleeve 1 - 2 , and inner sleeve 1 - 3 are pressed and move downwards at the same time; the rubber barrel sleeved on the inner sleeve 1 - 3 is expanded under the extruding force of the upper external sleeve 1 - 2 and the lower joint 10 , so as to seal the annulus between the drill column and well wall, or drill column and sleeve; during the downward movement process of the upper connector 1 - 1 , upper external sleeve 1 - 2 , and inner sleeve 1 - 3 ; the spring ejector 2 is squeezed out of the upper moving groove 11 - 1 by the central barrel 3 and enters the middle moving groove 11 - 2 , at this time, index of the weight indicator in the control room fluctuates once; the drill column is lowered continuously, and the upper connector 1 - 1 , upper external sleeve 1 - 2 , and inner sleeve 1 - 3 also move downwards continuously; the spring ejector 2 enters the lower moving groove 11 - 3 after finishing sliding in the middle moving groove 11 - 2 , at this time, index of the weight indicator in the control room fluctuates once again, and then the blowout preventer is in sealing state; during the downward movement process of the upper connector 1 - 1 , the flow guiding hole on the upper external sleeve 1 - 2 forms a butt joint with the check valve 6 on the central barrel, and the check valve 6 will be opened by the fluid pressure, thus the inner space of drill column is in communication with the annulus, so as to provide passage for subsequent well killing operation when there is heavy mud. The blowout preventer inside drill column 16 on the drill column can prevent the mud inside the drill column from returning upwards, and co-working with the underground blowout preventer can also seal the inner side of the drill column and the annulus, so as to control occurrence of blowout;
[0091] 3.) when the blowout is controlled, the drill column is lifted up and the drilling pressure is reduced, and the upper connector 1 - 1 , upper external sleeve 1 - 2 , and inner sleeve 1 - 3 move upwards at the same time, the rubber barrel sleeved on the inner sleeve 1 - 3 are not extruded but released, so the sealing is relieved; during the upward movement process of the upper connector 1 - 1 , upper external sleeve 1 - 2 , and inner sleeve 1 - 3 ; the spring ejector 2 is squeezed out of the lower moving groove 11 - 3 by the central barrel 3 and enters the middle moving groove 11 - 2 , at this time, index of the weight indicator in the control room fluctuates once; the drill column is lifted continuously, the upper connector 1 - 1 , upper external sleeve 1 - 2 , and inner sleeve 1 - 3 then move upwards continuously, the spring ejector 2 enters the upper moving groove 11 - 1 after finishing sliding in the middle moving groove 11 - 2 , at this time, index of the weight indicator in the control room fluctuates once again, then sealing of blowout preventer is relieved; during the upward movement process of the upper connector 1 - 1 , the butt joint of the flow guiding hole on the upper external sleeve 1 - 2 with the check valve 6 on the central barrel is relieved, and the check valve 6 will be closed; thus the blowout preventer can be reused and the torque from the upper part of the drill column is transferred downwards through the blowout preventer, so as to realize continuous drilling.
[0092] Embodiment 2
[0093] Embodiment 2 is similar with the Embodiment 1, as shown in FIG. 8 , the difference is as follows: the upper connector 1 - 1 , upper external sleeve 1 - 2 , and inner sleeve 1 - 3 are integrated to form the upper joint 1 , and lower end of the upper joint 1 is embedded between the lower joint 10 and the central barrel 3 . The outer wall of the upper joint 1 is matched with the inner wall of the lower joint through a spline, and the upper joint 1 able to move relative to the lower joint 10 along the spline pair. The lower joint 10 rotates along with the upper joint 1 at the same time, and outer side of the upper joint 1 is provided with an embossment or step. A rubber barrel 9 is sleeved outside the upper joint 1 which is under the embossment or step, and the rubber barrel 9 can be extruded and expanded by the end face of the upper joint 1 and the end face of the lower joint 10 . The second flow guiding hole is set on the upper joint 1 , and a second check valve 6 - 2 is set inside the second flow guiding hole 5 - 2 . When the upper joint 1 moves downwards, the first flow guiding hole 5 - 1 can be butt jointed with the second flow guiding hole 5 - 2 . The spring ejector 2 is set on the inner side of upper end of the upper external sleeve 1 - 2 and matched with the moving groove on the central barrel 3 . The central barrel 3 comprises primarily of the central barrel body 3 - 1 and support sleeve 3 - 2 which are fixedly connected with each other, and the support sleeve 3 - 2 is fixedly connected on the outer wall of the central barrel body 3 - 1 . Both the support sleeve 3 - 2 and the thrust bearing 7 are an integrated structure or made by splicing three or more pieces together, so as to facilitate installation. The support sleeve 3 - 2 is used to support the thrust bearing 7 and upper end of the upper joint 1 , such that the blowout preventer is always in a distressed state when in use, but will not fall off to ensure the user's safety. Through the thrust bearing 7 , the relative rotation between the central barrel 3 and the upper external sleeve 1 - 2 can be avoided during the well drilling process. Although the relative motion is caused by the relative motion due to lack of processing precision of the spline pair and poor underground working conditions, the clearance between the spline pair can be increased after long-term operation, so it is necessary to mount the thrust bearing 7 between the convex shoulder of the central barrel 3 and the upper end of the inner sleeve 1 - 3 , so as to make relative motion between the central barrel 3 and the internal sleeve 1 - 3 smoother, reduce the torque transference between the central barrel 3 and the internal sleeve 1 - 3 , and avoid reverse buckling between the central barrel 3 and the lower external sleeve 10 - 2 caused by the spline clearance and possible problem of the rotating velocity of the lower drill being faster than that of the upper drill.
[0094] The drill column of the present invention is installed with the underground annular blowout preventer, wherein the blowout preventer is mounted to the drill column at the position above the neutral point of the drill column. Because the neutral point is the tensioned and distressed demarcation point of drill column and the annular blowout preventer is set above the neutral point, the annular blowout preventer is in a distressed state during the normal well drilling process. The upper joint 1 of the underground annular blowout preventer is in the distressed state, and lower end of the upper joint 1 is matched with the lower joint 10 through the spline, and the drill column on the upper end of the blowout preventer can transfer the torque to lower end of the annular blowout preventer through the spline. The underground annular blowout preventer of the present invention can effectively prevent well kick or blowout. When the blowout preventer is not used to seal the well, it can be used to transfer torque. The underground annular blowout preventer of the present invention is lowered to seal and lifted to unseal, so the present invention is suitable for reuse. There is a kelly bar (driven by rotary disk) or drill column (top drive) on top of the drill column, and a signal receiver 21 is set on the upper end of the kelly bar or the lower end of the drill pipe. The signal receiver 21 is wirelessly connected with an alarm, and the signal receiver 21 is matched with the pressure detecting device near the drill to send and receive signal separately.
[0095] The assembly technique of the underground annular blowout preventer of the present invention comprises the following steps:
[0096] 1.) embedding the first check valve 6 - 1 into the first flow guiding hole 5 - 1 on the support sleeve 3 - 2 which is made by splicing multiple pieces, embedding the thrust bearing 7 which is made by splicing multiple pieces into the cavity of the upper joint 1 , and embedding the support sleeve 3 - 2 into the cavity of the upper joint 1 over the thrust bearing 7 ;
[0097] 2.) embedding the spring ejector 2 into the inner wall of the upper end of the upper joint 1 , sleeving the rubber sleeve 9 and the spacer ring 8 in order on the middle part outside the upper joint 1 , embedding the central barrel body 3 - 1 into the upper joint 1 from the lower end thereof, and passing through the support sleeve 3 - 2 , and fixedly connecting the central barrel body 3 - 1 and the support sleeve 3 - 2 ;
[0098] 3.) embedding the lower joint 10 along the external spline end at the lower end of the central barrel body 3 - 1 and the lower end of the upper joint 1 , stretching the outward expanding tool to the inner side of the central barrel body 3 - 1 and blocking the tool into the installation auxiliary hole, fixing the lower joint 10 while rotating the central barrel body 3 - 1 , or fixing the central barrel body 3 - 1 while rotating the lower joint 10 , so as to tighten the thread pair between the lower end of the central barrel body 3 - 1 and the lower joint 10 to the predetermined torque, such that the ejector on the spring ejector 2 slides into the upper moving groove 11 - 1 of the central barrel body 3 - 1 during the downward movement process of the upper joint 1 ;
[0099] 4.) mounting the assembled blowout preventer to the drill column at the position above neutral point thereof.
[0100] During the well drilling process, when there is a high pressure oil reservoir or oil reservoir, the working method of the drill column assembled with the underground annular blowout preventer of the present invention is the same as the operating method of Embodiment 1.
Embodiment 3
[0101] Embodiment 3 is similar to the Embodiments 1 and 2, as shown in FIG. 6 , the difference is as follows:
[0102] The upper connector 1 - 1 is integrated with the upper external sleeve 1 - 2 to form the upper joint component 1 - a, and an inner sleeve 1 - 3 is fixedly connected inside the lower end of the upper joint component 1 - a. The inner sleeve 1 - 3 is sleeved outside of the central barrel body 3 - 1 , and lower end of the inner sleeve 1 - 3 is embedded between the lower joint 10 and the central barrel body 3 - 1 . The outer wall of the lower end of the inner sleeve 1 - 3 is matched with the upper joint component 1 - a through a spline, and the inner sleeve 1 - 3 can move freely relative to the lower joint 10 along the spline pair. A rubber barrel 9 is sleeved outside of the inner sleeve 1 - 3 , and the upper end of which is embedded inside the upper joint component 1 - a; therefore, both ends of the sleeve are in contact with the lower end face of the upper joint component 1 - a and the upper end face of the lower joint, and the rubber barrel 9 can be extruded and expanded by lower end face of the upper joint component 1 - a and upper end face of lower joint. The second check valve 6 - 2 is set on the upper joint component 1 - a, and when the upper joint component 1 - a moves downwards, the first flow guiding hole 5 - 1 can be butt jointed with the second flow guiding hole 5 - 2 . The first flow guiding hole 5 - 1 is set with a first check valve 6 - 1 , and the second check valve 6 - 2 is set inside the second flow guiding hole 5 - 2 . The spring ejector 2 is set inside the upper end of the upper joint component 1 - a and matched with the moving grooves on the central barrel body 3 - 1 . A support sleeve 3 - 2 is fixedly connected to the outer wall of the central barrel body 3 - 1 to support the thrust bearing and lower end of the upper joint component 1 - a, such that the blowout preventer is always in a distressed state when in use, but will not fall off to ensure the user's safety. Through the thrust bearing 7 , relative rotation between the central barrel 3 and the upper joint component 1 - a can be avoided during the well drilling process. Although the relative motion is caused by the relative motion due to lack of processing precision of the spline pair and poor underground working conditions, the clearance between the spline pair can be increased after long-term operation. It is necessary to mount the thrust bearing 7 between the convex shoulder of the central barrel 3 and the upper end of the inner sleeve 1 - 3 , so as to make relative motion between the central barrel 3 and the internal sleeve 1 - 3 smoother, reduce the torque transference between the central barrel 3 and the internal sleeve 1 - 3 , and avoid reverse buckling between the central barrel 3 and the lower external sleeve 10 - 2 caused by the spline clearance and the possible problem of the rotating velocity of the lower drill being faster than that of the upper drill.
[0103] The drill column of the present invention is installed with the underground annular blowout preventer, wherein the blowout preventer is mounted to the drill column at the position above the neutral point of the drill column. Because the neutral point is the tensioned and distressed demarcation point of drill column and the annular blowout preventer is set above the neutral point, the annular blowout preventer is in a distressed state during the normal well drilling process. The upper joint component 1 - a of the underground annular blowout preventer is in the distressed state, and the lower end of the upper joint component 1 - a is matched with the lower joint 10 through the spline. The drill column on the upper end of the blowout preventer can transfer the torque to lower end of the annular blowout preventer through the spline; therefore, the underground annular blowout preventer of the present invention can effectively prevent well kick or blowout, and when the blowout preventer is not used to seal the well it can be used to transfer torque. The underground annular blowout preventer of the present invention is lowered to seal and lifted to unseal, so the present invention is suitable for reuse. There is a kelly bar (driven by rotary disk) or drill column (top drive) on top of the drill column, and a signal receiver 21 is set on the upper end of the kelly bar or the lower end of the drill pipe. The signal receiver 21 is wirelessly connected with an alarm, and the signal receiver 21 is matched with the pressure detecting device near the drill to send and receive signals separately.
[0104] The assembly technique of the underground annular blowout preventer of the present invention comprises the following steps:
[0105] 1.) fixing the inner sleeve 1 - 3 , sleeving multiple spacer rings 8 and the rubber barrel 9 outside of the inner sleeve 1 - 3 along the thread direction on the upper end of the inner sleeve 1 - 3 , and limiting the multiple spacer rings 8 and the rubber barrel 9 to upside of the convex shoulder at the middle of the inner sleeve 1 - 3 ;
[0106] 2.) embedding the first check valve 6 - 1 to the support sleeve 3 - 2 , embedding the spring ejector 2 to the inner wall of the upper joint component 1 - a, embedding the support sleeve 3 - 2 into upper joint component 1 - a from the lower end thereof, embedding the thrust bearing 7 into the upper joint component 1 - a from the lower end thereof, and fixedly connecting the lower end of the upper joint component 1 - a and the upper end of the inner sleeve 1 - 3 ;
[0107] 3.) embedding the central barrel body 3 - 1 into the inner sleeve 1 - 3 from the lower end thereof and passing through the support sleeve 3 - 2 , fixedly connecting the central barrel body 3 - 1 and the support sleeve 3 - 2 , and embedding the second check valve 6 - 2 to the inner wall of the upper joint component 1 - a;
[0108] 4.) embedding the lower joint 10 along the lower end of the central barrel body 3 - 1 and the external spline end of the inner sleeve 1 - 3 , stretching the outward expanding tool to the inner side of the central barrel body 3 - 1 and blocking the tool into the installation auxiliary hole, fixing the lower joint 10 while rotating the central barrel body 3 - 1 , or fixing the central barrel body 3 - 1 while rotating the lower joint 10 , so as to tighten the thread pair between the lower end of the central barrel body 3 - 1 and the lower joint 10 to the predetermined torque, such that the ejector on the spring ejector 2 slides into the upper moving groove 11 - 1 of the central barrel body 3 - 1 during the downward movement process of the upper joint 1 ;
[0109] 5.) mounting the assembled blowout preventer to the drill column at the position above the neutral point thereof.
[0110] During the well drilling process, when there is a high pressure oil reservoir or oil reservoir, the working method of the drill column assembled with the underground annular blowout preventer of the present invention is the same as the operating method of Embodiments 1 and 2.
[0111] To sum up, in the underground annular blowout preventer of the present invention, the upper joint can be an integrated structure or separated component structure and the lower end can also be an integrated structure or a structure formed by fixedly connecting lower connector 10 - 1 and lower external sleeve 10 - 2 , so as to provide different options for specific requirements in different situations. In the present invention, connections between each component of separate upper joint can be either fixed connections through the API drill pipe joint thread or connections through a common thread together with a pin and sealing member. Similarly, connections between the lower connector 10 - 1 and the lower external sleeve 10 - 2 can be either connections through the API drill pipe joint thread or connections through a common thread together with pin and sealing member.
[0112] The underground annular blowout preventer of the present invention is simple in structure, innovative in design, and high in reliability. When it is used together with an overflow and well kick pre-warning system, and the check valve is near the drill; when the signal of underground well kick and blowout is received from the ground, the drill rod is lowered to increase to a drilling pressure, so as to seal the well quickly and realize communication between the inner side of the drill pipe and the annulus, and then the pipe column is lifted to unseal the well. The present invention can effectively prevent a blowout accident and has a high feasibility. In the underground annular blowout preventer of the present invention, the torque transferred between the upper and lower drill pipe is completed by the spline pair between the upper joint and the lower joint of the annular blowout preventer, so it can sustain larger torque. Each component of the blowout preventer can sustain a reasonable amount of stress and is high in reliability. The present invention can be mounted into a well at different depth over the demarcation point of drill pipe, and it can work with the drill in realizing a sealing and unsealing for multiple times without a need to take out drill pipe to replace the blowout preventer. This helps to reduce cost of the equipment and the entire well drilling process due to the reusability. Due to the first and second check valves, the underground annular blowout preventer of the present invention can prevent the high pressure fluid in the annulus from entering the drill pipe when the annular seal loses effectiveness due to other reasons; and the underground annular blowout preventer of the present invention provides sealing at the peripheries of the first and the second flow guiding holes with a sealing member, so as to ensure that inner side of the drill pipe will not be in communication with the annulus during normal drilling process. Additionally, due to the first and second check valves, solid impurities in mud cannot damage the sealing layer and the sealing member; therefore, the service life of the sealing members is prolonged. During the well sealing process, the drill pipe can be properly lifted and lowered quickly. The drill pipe is re-lowered after the drill is lifted from the bottom of well in short time, so as to seal the annular blowout preventer and thus prevent the drill from being blocked. During the well sealing process, it is only necessary to increase the drilling pressure properly to make the spring ejector slide into the lower moving groove from the upper moving groove, and the increased drilling pressure can be controlled within the maximum drilling pressure limit that the lower drilling tool can sustain, such that the lower drilling tool of the drill pipe can be protected at much as possible during the process of sealing annulus. The assembly technique of the underground annular blowout preventer of the present invention is unique in design and innovative in technique. By using the assembly technique, the sealing effect of the blowout preventer can be guaranteed. Quick sealing and unsealing are realized due to the innovative action. A stable and reliable structure, and long service life of the blowout preventer are guaranteed.
[0113] One in the drawings and described above is skilled in the art will understand that the embodiment of the present invention as shown exemplary only and not intended to be limiting.
[0114] It will thus be seen that the objects of the present invention have been fully and effectively accomplished. The embodiments have been shown and described for the purposes of illustrating the functional and structural principles of the present invention and is subject to change without departure from such principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.
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An underground annular blowout preventer, which belongs to the technical field of underground blowout prevention, includes an upper joint and a lower joint are sleeved outside a central barrel. The lower end of the central barrel is fixedly connected with the lower joint. The lower end of the upper joint is sleeved on the inner side of the upper end of the lower joint. The upper joint is matched with the lower joint through a spline. The lower end of the upper joint can freely move relative to the lower joint along a spline pair. At least one rubber barrel is sleeved on the outer side of the upper joint. The rubber barrel can be extruded and expanded by the upper joint and the lower joint. The underground annular blowout preventer of the present invention can transmit large torque, has a simple structure, long service life, is convenient to use, and can be repeatedly used. The underground annular blowout preventer is used in coordination with a check valve of a near drill in the well drilling process, so that quick sealing of a well can be ensured, and well blowout accidents can be effectively prevented. A pipe column is lowered to seal the well and is lifted to open the well, and the inside of the drill rod is in communication with an annular space after the well is sealed, which facilitates replacement for heavy mud lubrication operations.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application Ser. No. 10/776,721, filed Feb. 11, 2004, entitled “REMOVABLE VENA CAVA FILTER”, which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/446,711, filed Feb. 11, 2003, entitled, “REMOVABLE VENA CAVA CLOT FILTER,” each of which is hereby incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to medical devices. More particularly, the invention relates to a removable vena cava clot filter that can be percutaneously placed in and removed from the vena cava of a patient.
[0003] Filtering devices that are percutaneously placed in the vena cava have been available for over thirty years. A need for filtering devices arises in trauma patients, orthopedic surgery patients, neurosurgery patients, or in patients having medical conditions requiring bed rest or non-movement. During such medical conditions, the need for filtering devices arises due to the likelihood of thrombosis in the peripheral vasculature of patients wherein thrombi break away from the vessel wall, risking downstream embolism or embolization. For example, depending on the size, such thrombi pose a serious risk of pulmonary embolism wherein blood clots migrate from the peripheral vasculature through the heart and into the lungs.
[0004] A filtering device can be deployed in the vena cava of a patient when, for example, anticoagulant therapy is contraindicated or has failed. Typically, filtering devices are permanent implants, each of which remains implanted in the patient for life, even though the condition or medical problem that required the device has passed. In more recent years, filters have been used or considered in preoperative patients and in patients predisposed to thrombosis which places the patient at risk for pulmonary embolism.
[0005] The benefits of a vena cava filter have been well established, but improvements may be made. For example, filters generally have not been considered removable from a patient due to the likelihood of endotheliosis of the filter during treatment. After deployment of a filter in a patient, proliferating intimal cells begin to accumulate around the filter struts which contact the wall of the vessel. After a length of time, such ingrowth prevents removal of the filter without risk of trauma, requiring the filter to remain in the patient. As a result, there has been a need for an effective filter that can be removed after the underlying medical condition has passed.
[0006] Moreover, conventional filters commonly become off-centered or tilted with respect to the hub of the filter and the longitudinal axis of the vessel in which it has been inserted. As a result, the filter including the hub and the retrieval hook engage the vessel wall along their lengths and potentially become endothelialized therein. This condition is illustrated in prior art FIG. 1 in which a prior art filter 13 has been delivered through a delivery sheath 25 into a blood vessel 51 . In the event of this occurrence, there is a greater likelihood of endotheliosis of the filter to the blood vessel along a substantial length of the filter wire. As a result, the filter becomes a permanent implant in a shorter time period than otherwise.
[0007] Some filters have been designed so that the filter has minimal contact with the vessel wall. Ideally, some filters can be removed after several weeks with minimal difficulty and little injury to the vessel wall. One such filter is described in U.S. Pat. No. 5,836,968. The filter is designed so that the filter wires or struts are not positioned parallel to the vessel walls or not in contact with the vessel walls for a substantial portion of the length of the filters. The ends of the struts contact the vessel walls and provide anchoring to reduce the likelihood of filter migration. When the filter is removed, a wire is docked to one end of the device while a sheath or sleeve is passed over the wire. Using counter traction by pulling the wire while pushing the sheath, the sheath is passed over the filter and the filter struts are retracted from the vessel wall. In this way, only small point lesions are created where the filter was attached to the vessel wall.
[0008] The filter of U.S. Pat. No. 5,836,968 teaches two levels of oppositely expanding filter wires or struts to insure that the filter is properly aligned in the lumen of the vessel. If the filter tilts or becomes misaligned with the central axis of the vessel, the filter wires will contact the wall of the vessel along a greater area, and become endothelialized. As a result of the two levels, removal of the filter from the blood vessel becomes impossible or at least difficult.
[0009] Additionally, the configuration of the second level of filter wires in the device of U.S. Pat. No. 5,836,968 provides a filter which may be too long for the segment of the vessel that the filter would normally be placed. The normal placement segment of a vena cava filter is between the femoral veins and the renal veins. If the lower part of the filter extends into the femoral veins, filtering effectiveness will be compromised. Moreover, it is not desirable to have filter wires crossing the origin of the renal veins, since the filter wires may interfere with the flow of blood from the kidneys. In the device disclosed in U.S. Pat. No. 5,836,968, both levels of filter wires are attached at one point as a bundle at the central axis of the filter. The resulting diameter of this bundle of filter wires results in a filter that may be too large for easy placement and becomes an obstacle to blood flow in the vena cava.
BRIEF SUMMARY OF THE INVENTION
[0010] The present invention provides a vena cava filter comprising struts configured to align the filter about the center axis of a blood vessel and minimize engagement with the blood vessel. The filter comprises a plurality of primary struts, each of which having a first end. A hub axially connects the first ends of the struts to define a central axis of the filter. Each primary strut has a curved member extending from the central axis. Each curved member terminates at an anchoring hook to engage the blood vessel at a first axial plane and secure the filter in the blood vessel. Each anchoring hook includes a barb formed at an angle relative to the strut to allow a removal sheath to be advanced over the filter and allow the hooks to be removed straight away from the vessel wall, resulting in minimal vessel damage. The filter further comprises a plurality of secondary struts. Each secondary strut is connected to one of the curved members and extends therefrom to a free end for engaging the blood vessel at a second axial plane, aligning the filter in the blood vessel.
[0011] In one embodiment, a set of at least two secondary struts are connected to the curved member of one primary strut. The set of secondary struts extend radially from each side of the primary strut, forming a netting configuration of the filter. In another embodiment, one secondary strut is connected to the curved member of one primary strut. The secondary strut extends from the primary strut and is in radial alignment with the primary strut, avoiding interference with blood flow.
[0012] In a collapsed configuration, the vena cava filter occupies a reduced diameter, since the hub is the origin to only primary struts. In an expanded configuration, the hub occupies a reduced cross-sectional area. As a result, interference with blood flow is lessened in the vena cava.
[0013] In an expanded configuration, the vena cava filter occupies a reduced length, since the secondary struts merely extend within the axial length of the primary struts. As a result, the filter can more easily be placed in the vena cava of a patient, lessening the risk of interference in the femoral and renal veins.
[0014] Further aspects, features, and advantages of the invention will become apparent from consideration of the following description and the appended claims when taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] FIG. 1 is a side view of a prior art filter deployed in a blood vessel;
[0016] FIG. 2 is an illustration of the anatomy of the renal veins, the femoral veins, and the vena cava in which one embodiment of a vena cava filter of the present invention is deployed;
[0017] FIG. 3 is a side perspective view of one embodiment of the vena cava filter of the present invention;
[0018] FIG. 4 is a cross-sectional view of a blood vessel showing the filter of the present invention partially deployed;
[0019] FIG. 5 is a cross-sectional view of a blood vessel showing the filter of the present invention fully deployed;
[0020] FIG. 6 is a cross-sectional view of a blood vessel in which the filter of FIG. 3 has been deployed;
[0021] FIG. 7 is a cross-sectional view of the blood vessel of FIG. 6 taken along line 7 - 7 ;
[0022] FIG. 8 is a cross-sectional view of a blood vessel showing a portion of a retrieval device for the filter in FIG. 3 ;
[0023] FIG. 9 is a side perspective view of a vena cava filter in accordance with another embodiment of the present invention; and
[0024] FIG. 10 is a cross-sectional view of a blood vessel in which the filter in FIG. 9 is disposed.
DETAILED DESCRIPTION OF THE INVENTION
[0025] In accordance with a first embodiment of the present invention, FIG. 2 illustrates a vena cava filter 20 implanted in the vena cava 50 for the purpose of lysing or capturing thrombi carried by the blood flowing through the femoral veins 54 , 56 toward the heart and into the pulmonary arteries. As shown, the femoral veins from the legs merge at juncture 58 into the vena cava 50 . The renal veins 60 from the kidneys 62 join the vena cava 50 downstream of juncture 58 . The portion of the vena cava 50 , between the juncture 58 and the renal veins 60 , defines the inferior vena cava 52 in which the vena cava filter 20 has been percutaneously deployed through one of the femoral veins 54 . Preferably, the vena cava filter 20 has a length smaller than the length of the inferior vena cava 52 . If the lower part of the filter extends into the femoral veins, filtering effectiveness will be compromised and if the filter wires cross over the origin of the renal veins the filter wires might interfere with the flow of blood from the kidneys.
[0026] The first embodiment of the present invention will be discussed with reference to FIGS. 3-8 in which filter 20 is shown. FIG. 3 illustrates filter 20 comprising four primary struts 12 each having first ends that emanate from a hub 10 . Hub 10 secures the first ends of primary struts 12 together in a compact bundle to define a central or longitudinal axis of the filter. The hub 10 has a minimal diameter for the size of wire used to form the struts. Preferably, the primary struts 12 are formed from stainless steel wire, MP35N, Nitinol, or any other suitable superelastic material that will result in a self-opening or self-expanding filter. In this embodiment, the primary struts 12 are formed from wire having a round cross-section with a diameter of about 0.015 inches. Of course, it is not necessary that the primary struts have a round cross-section. For example, the primary struts could have a square shaped or other suitable shaped cross section without falling beyond the scope or spirit of the present invention.
[0027] Each primary strut 12 is formed with a first curved portion 13 that is configured to bend away from the longitudinal or central axis of the filter 20 and a second curved portion 15 that is configured to bend toward the longitudinal axis of the filter 20 . Each primary strut 12 maintains a non-parallel relationship with the longitudinal axis of the filter 20 . The primary struts 12 terminate at anchoring hooks 18 that will anchor in the vessel wall when the filter 20 is deployed at a delivery location in the blood vessel. When the filter is deployed, the anchoring hooks define a first axial plane to secure the filter in the blood vessel. The anchoring hooks 18 prevent the filter 20 from migrating from the delivery location in the blood vessel where it has been deposited. The primary struts 12 are shaped and dimensioned such that, when the filter 20 is deployed and expanded, the filter 20 has a diameter of about 35 mm and a length of about 5 cm. For example, when expanded, the filter 20 may have a diameter of between about 30 mm and 40 mm, and a length of between about 3 cm and 7 cm. The primary struts 12 have sufficient spring strength that when the filter is deployed the anchoring hooks 18 will anchor into the vessel wall.
[0028] In this embodiment, each primary strut 12 has two secondary struts 14 secured thereto by laser welding, brazing, crimping or any suitable process that will avoid damaging the material or adding to the thickness of the filter and thus the size of the delivery system. The secondary struts 14 may be made from the same type of material as the primary struts. However, the secondary struts may have a smaller diameter, e.g., about 0.012 inches, than the primary struts. Each of the secondary struts 14 is formed of a single curve and is secured to one of the primary struts 12 on its first curved portion 13 such that the secondary strut 14 becomes a continuation or an extension of the first curved portion 13 of the primary strut 12 . In this embodiment, two secondary struts 14 flare away from each side of one primary strut 12 to form a part of a netting configuration of the filter 20 .
[0029] When opened, free ends 17 of the secondary struts 14 will expand radially outwardly to a diameter of about 35 mm to engage the vessel wall. For example, the secondary struts 14 may expand radially outwardly to a diameter of between about 30 mm and 40 mm. The free ends 17 define a second axial plane where the vessel wall is engaged. The secondary struts 14 function to stabilize the position of the filter 10 about the center of the blood vessel in which it is deployed. As a result, the filter 20 has two layers or planes of struts longitudinally engaging the vessel wall of the filter. The length of the filter is preferably defined by the length of a single set of primary struts. Furthermore, the diameter of the hub 10 is defined by the size of a bundle containing the primary struts 12 . In this embodiment, the eight secondary struts, although maintaining the filter in a centered attitude relative to the vessel wall and formed as a part of the netting configuration of the filter, minimally add to the diameter of the hub or the overall length of the filter.
[0030] FIG. 4 illustrates the filter 20 partially deployed in inferior vena cava 52 . For deployment of the filter 20 , a delivery tube 24 is percutaneously inserted through the patient's vessels such that the distal end of the delivery tube is at the location of deployment. In this embodiment, a wire guide is preferably used to guide the delivery tube to the location of deployment. The filter is preferably inserted through the proximal end of the delivery tube 24 with the removal hook 16 leading and free ends of the primary struts 12 held by a filter retainer member. The filter retainer member may be connected to a pusher wire (not shown) that is fed through the proximal end of the delivery tube 24 until the filter reaches the distal end of the delivery tube 24 . For a more complete disclosure of a filter delivery system that may be used to deliver the filter 20 to a desired location, reference may be made to U.S. Pat. No. 5,324,304 which is incorporated herein by reference.
[0031] As shown in FIG. 4 , filter 20 is deployed leading with removal hook 16 from the delivery tube 24 . The secondary struts expand first. When the free ends of the secondary struts emerge from the distal end of delivery tube 24 , the secondary struts expand to an expanded position shown in FIG. 4 . The free ends engage the inner wall of the vessel in which the filter is being deployed. The free ends of the secondary struts function to stabilize the attitude of filter 20 about the center of the blood vessel. The filter is then pushed further by the pusher wire (not shown) until it is fully deployed as shown in FIG. 5 .
[0032] As shown in FIG. 5 , the ends of the primary struts 12 and the secondary struts 14 are in engagement with the vessel wall. The anchoring hooks of the primary struts have anchored the filter at the location of deployment in the vessel, preventing the filter 20 from moving with the blood flow through the vessel. As a result, the filter 20 is supported by two sets of struts that are spaced axially along the length of the filter. The struts avoid engaging the vessel wall along their lengths and thus avoid becoming endothelialized in the vessel wall.
[0033] FIGS. 6 and 7 show the filter 20 fully expanded after being deployed in inferior vena cava 52 . In FIG. 6 , the inferior vena cava 52 has been broken away so that the filter 20 can be seen. The direction of the blood flow BF is indicated in FIG. 6 by the arrow that is labeled BF. The anchoring hooks 18 at the ends of the primary struts 12 are shown as being anchored in the inner lining of the inferior vena cava 52 . The anchoring hooks 18 include barbs 19 that, in one embodiment, project toward the hub 10 of the filter. The barbs 19 function to retain the filter 20 in the location of deployment.
[0034] In this embodiment, the filter 20 is pushed in a direction BF of the blood flow by the pusher wire (not shown) during deployment. The pusher wire pushes the filter 20 from the delivery tube, causing the barbs 19 to move in the direction BF of the blood flow and secure anchoring hooks 18 in the inferior vena cava 52 . The spring biased configuration of the primary struts 12 causes the anchoring hooks 18 to puncture the vessel wall and anchor the filter at the location of deployment. After initial deployment, the pressure of the blood flow on the filter 20 contributes in maintaining the barbs 19 anchored in the inner lining of the inferior vena cava 52 . As seen in FIG. 6 , the free ends 17 of secondary struts 14 also have a spring biased configuration to engage with the vessel wall. In this embodiment, the free ends 17 of secondary struts 14 are not provided with anchoring hooks, minimizing the trauma of retrieving the filter 20 .
[0035] FIG. 7 illustrates a netting configuration formed by the primary struts 12 , secondary struts 14 , and the hub 10 . The netting configuration shown in FIG. 7 functions to catch thrombi carried in the blood stream prior to reaching the heart and lungs to prevent the possibility of a pulmonary embolism. The netting configuration is sized to catch and stop thrombi that are of a size that are undesirable to be carried in the vasculature of the patient. As shown, the hub 10 houses a bundle of first ends of the four primary struts 14 . Due to its compacted size, the hub minimally resists blood flow.
[0036] As seen in FIG. 6 , the hub 10 and removal hook 16 are positioned downstream from the location at which the anchoring hooks 18 are anchored in the vessel. When captured by the struts, thrombi remains lodged in the filter. The filter along with the thrombi may then be percutaneously removed from the vena cava. When the filter 20 is to be removed, the removal hook 16 is preferably grasped by a retrieval instrument that is percutaneously introduced in the vena cava in the direction opposite to the direction in which the filter was deployed.
[0037] FIG. 8 illustrates part of a retrieval device 65 being used in a procedure for removing the filter 20 from the inferior vena cava 52 . The retrieval device 65 is percutaneously introduced into the superior vena cava via the jugular vein. In this procedure, a removal catheter or sheath 68 of the retrieval device 65 is inserted into the superior vena cava. A wire 70 having a loop snare 72 at its distal end is threaded through the removal sheath 68 and is exited through the distal end of the sheath 68 . The wire is then manipulated by any suitable means from the proximal end of the retrieval device such that the loop snare 72 captures the removal hook 16 of the filter 20 . Using counter traction by pulling the wire 70 while pushing the sheath 68 , the sheath 68 is passed over the filter. As the sheath 68 passes over the filter 20 , the secondary struts 14 and then the primary struts 12 engage the edge of the sheath 68 and are caused to pivot at the hub 10 toward the longitudinal axis of the filter. The pivoting toward the longitudinal axis causes the ends of the struts 14 and 12 to be retracted from the vessel wall. In this way, only surface lesions 74 and small point lesions 76 on the vessel wall are created in the removal procedure. As shown, the surface lesions 74 are created by the ends of the secondary struts 14 and the small point legions 76 are created by the anchoring hooks 18 of the primary struts 12 . However, it is to be noted that any other suitable procedure may be implemented to remove the filter from the patient.
[0038] A second embodiment of the present invention will be discussed with reference to FIGS. 9 and 10 in which a filter 28 is shown. FIG. 9 illustrates filter 28 comprising six primary struts 32 each having first ends that emanate from a hub 30 . Hub 30 secures the first ends of primary struts 32 together in a compact bundle to define a central axis of the filter. Similar to the hub 10 in the first embodiment discussed above, the hub 30 in this embodiment has a minimal diameter for the size of wire used to form the struts.
[0039] The primary struts 32 in this embodiment are similar in structure to the primary struts 12 in the first embodiment above. For example, in the second embodiment, each primary strut 32 of the filter 28 includes first and second curved portions 33 and 35 , removal hook 36 , free ends 37 , an anchoring hook 38 , and a barb 39 which are respectively similar to the first and second curved portions 13 and 15 , removal hook 16 , free ends 17 , the anchoring hook 18 , and the barb 19 of the filter 28 in the first embodiment. Preferably, the primary struts 32 are shaped and dimensioned such that, when the filter 28 is deployed and expanded, the filter 28 has a diameter of about 35 mm and a length of about 5 cm. For example, when expanded, the filter 28 may have a diameter of between about 30 mm and 40 mm, and a length of between about 3 cm and 7 cm. The primary struts 32 have sufficient spring strength such that when the filter is deployed the anchoring hooks 38 will anchor into the vessel wall.
[0040] Preferably, the primary struts 32 are formed of the same material as the primary struts 12 mentioned above, e.g., stainless steel wire, MP35N, Nitinol, or any other suitable material. In this embodiment, the primary struts 32 are formed from wire having a round cross-section with a diameter of about 0.015 inches. As stated above, it is not necessary that the primary struts have a round cross-section.
[0041] In this embodiment, each primary strut 32 has one secondary strut 34 secured thereto by laser welding, brazing, crimping or any suitable process that will not damage the material or add to the thickness of the filter and thus the size of the delivery system. The secondary struts 34 may be made from the same type of material as the primary struts. Preferably, the secondary struts may have a smaller diameter, e.g., about 0.012 inches, than the primary struts. As in the first embodiment, each of the secondary struts 34 in this embodiment is formed of a single curve and is secured to one of the primary struts 32 on the first curved portion such that the secondary strut 34 becomes a continuation or extension of the first curved portion of the primary strut 32 . As shown, each of the secondary struts 34 flares away from one primary strut 32 and is in radial alignment therewith.
[0042] When opened, the free ends of the secondary struts 34 will expand outwardly to a diameter of about 35 mm to engage the vessel wall. For example, the secondary struts 34 may expand outwardly to a diameter of between about 30 mm and 40 mm. Similar to the secondary struts 14 in the first embodiment, the secondary struts 34 in this embodiment function to stabilize the position of the filter 28 about the center of the blood vessel in which it is deployed. As a result, the filter 28 has two layers or planes of struts longitudinally engaging the vessel wall of the filter. The length of the filter is preferably defined by the length of a single set of primary struts. Furthermore, the diameter of the hub 30 is defined by the size of a bundle containing the primary struts 32 . As in the first embodiment, the secondary struts in this embodiment, although maintaining the filter in a centered attitude relative to the vessel wall and formed as a part of a netting configuration of the filter, minimally add to the diameter of the hub or the overall length of the filter.
[0043] FIG. 10 illustrates the netting configuration of the filter 28 formed by the primary struts 32 and the hub 30 . As shown, the secondary struts 34 are positioned behind and in alignment with the primary struts 32 and, thus, avoid substantially affecting blood flow. The netting configuration functions to catch thrombi carried in the blood stream prior to reaching the heart and lungs to prevent the possibility of a pulmonary embolism. The netting configuration is sized to catch and stop thrombi that are of a size that are undesirable to be carried in the vasculature of a patient. As shown, the hub 30 houses a bundle of ends of the six primary struts 34 . Due to its compacted size, the hub minimally resists blood flow.
[0044] It is to be noted that the filter 28 may be deployed in the vena cava in the same manner previously discussed for filter 20 with reference to FIGS. 2 , 4 , and 5 . Additionally, the filter 28 may be removed from the vena cava with the removal procedure previously discussed for filter 20 with reference to FIG. 8 .
[0045] Although the embodiments of this device have been disclosed as being constructed from wire having a round cross section, it could also be cut from a tube of suitable material by laser cutting, electrical discharge machining or any other suitable process.
[0046] While the present invention has been described in terms of preferred embodiments, it will be understood, of course, that the invention is not limited thereto since modifications may be made to those skilled in the art, particularly in light of the foregoing teachings.
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A removable filter for capturing thrombi in a blood vessel. The filter comprises a plurality of primary struts having first ends connected to each other to define a central axis of the filter. Each primary strut has a curved member extending from the central axis and terminates at an anchoring hook to engage the blood vessel at a first axial plane. The filter further comprises a plurality of secondary struts connected to the curved members of the primary struts and extending therefrom to a free end at a second axial plane to centralize the filter in the blood vessel.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to a heat dissipation structure of electronic shield cover, and more particularly to a heat dissipation structure, which is applicable to an isolation case for quickly and uniformly dissipating the heat generated by a heat source so as to avoid accumulation of the heat around the heat source and avoid abnormal rise of the temperature of a local section of the isolation case.
[0003] 2. Description of the Related Art
[0004] It is known that an electrically conductive and magnetically conductive shield cover (generally made of metal material) is often used to enclose and cover electronic components on a circuit board so as to prevent the electronic components from being interfered with by external electromagnetic waves. Along with popularization and diversification of the application of the electronic components, the electronic components enclosed in the shield cover have become unlimited to low-power heat generation components and more and more high-power electronic components (such as processors and power transistors) are also arranged in the shield cover. The high-power electronic components will generate high heat in operation. The shield cover defines a closed space isolated from outer side so that the heat dissipation efficiency for the electronic components is poor. As a result, it often takes place that the heat generated by the electronic components accumulates around the heat source to cause excessive rise of the temperature of a local section of the shield cover. This will serious affect the operation of the electronic components.
[0005] In order to solve the above problem of excessive rise of the temperature of the local section, in general, a heat conduction component with better heat conduction efficiency, (such as a heat pipe), is used to partially contact the shield cover. In addition, a heat dissipation assembly (such as radiating fin assembly or cooling fan) is disposed on another part of the heat conduction component. The heat conduction component serves to transfer the heat to the other part to be dissipated from the heat dissipation assembly. In this case, the heat is prevented from concentrating so that the excessive rise of the temperature of the local section can be avoided.
[0006] However, the cost for the above structure is relatively high and it is uneconomic to apply such structure to the low-price electronic products. Moreover, in the above structure, most of the heat is dissipated by way of radiation so that the heat dissipation effect is not satisfying.
SUMMARY OF THE INVENTION
[0007] It is therefore a primary object of the present invention to provide a heat dissipation structure of electronic shield cover, which is able to quickly spread and outward dissipate the heat generated by a heat source in a direction away from the heat source so as to avoid concentration of the heat and abnormal rise of the temperature of a local area.
[0008] It is a further object of the present invention to provide the above heat dissipation structure of electronic shield cover, in which no expensive heat conduction component is used so that the manufacturing cost of the heat dissipation structure is lowered to promote the economic efficiency.
[0009] To achieve the above and other objects, the heat dissipation structure of electronic shield cover of the present invention includes: a heat-conductive and magnetically conductive isolation case disposed around at least one preset heat source to enclose the heat source; at least one heat conduction plate assembly having at least one electroconductive heat conduction plate; and at least one heat spreader, which is able to quickly conduct heat along the surface. The heat spreader is attached to and in contact with the heat conduction plate assembly. The heat spreader has a proximal-to-heat-source section proximal to the heat source and a distal-from-heat-source section distal from the heat source. At least one of the heat conduction plate assembly and the heat spreader is in contact with the isolation case.
[0010] In the above heat dissipation structure of electronic shield cover, the heat conduction plate assembly includes at least two heat conduction plates. The heat spreader is disposed between the heat conduction plates in contact with the heat conduction plates.
[0011] In the above heat dissipation structure of electronic shield cover, the heat conduction plates of the heat conduction plate assembly have equal size and identical shape.
[0012] In the above heat dissipation structure of electronic shield cover, the heat spreader has an area smaller than that of the heat conduction plates.
[0013] In the above heat dissipation structure of electronic shield cover, the heat spreader is an elongated plate body.
[0014] In the above heat dissipation structure of electronic shield cover, the heat spreader has an elongated main extension section and at least one branch section obliquely extending from one side of the main extension section.
[0015] In the above heat dissipation structure of electronic shield cover, the heat spreader has an elongated main extension section and at least one branch section obliquely extending from each of two sides of the main extension section.
[0016] In the above heat dissipation structure of electronic shield cover, the branch section obliquely extends in a direction away from the heat source assembly and the main extension section.
[0017] In the above heat dissipation structure of electronic shield cover, an electroconductive adhesive layer is disposed between the heat conduction plate assembly and the heat spreader.
[0018] In the above heat dissipation structure of electronic shield cover, an electroconductive adhesive layer is disposed between the isolation case and the heat conduction plate assembly.
[0019] In the above heat dissipation structure of electronic shield cover, the isolation case is composed of an isolation casing surrounding the heat source and an isolation cover mated with upper side of the isolation casing to cover the heat source.
[0020] The present invention can be best understood through the following description and accompanying drawings, wherein:
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1 is a perspective exploded view of a first embodiment of the present invention;
[0022] FIG. 2 is a perspective partially assembled view of the first embodiment of the present invention, showing that the first embodiment of the present invention is applied to an isolation case;
[0023] FIG. 3 is a perspective assembled view of the first embodiment of the present invention, showing the application thereof;
[0024] FIG. 4 is a perspective assembled view of a second embodiment of the present invention, showing the application thereof;
[0025] FIG. 5 is a perspective assembled view of a third embodiment of the present invention, showing the application thereof;
[0026] FIG. 6 is a perspective exploded view of a fourth embodiment of the present invention;
[0027] FIG. 7 is a perspective assembled view of the fourth embodiment of the present invention, showing the application thereof;
[0028] FIG. 8 is a perspective assembled view of a fifth embodiment of the present invention, showing the application thereof; and
[0029] FIG. 9 is a perspective assembled view of a sixth embodiment of the present invention, showing the application thereof.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] Please refer to FIGS. 1 to 3 . According to a first embodiment, the heat dissipation structure of electronic shield cover of the present invention includes a heat conduction plate assembly 10 and a heat spreader 2 . The heat conduction plate assembly 10 is one single heat conduction plate (made of metal material) with electroconductivity. One face of the heat conduction plate (heat conduction plate assembly 10 ) is provided with a contact face 101 . In practice, the heat conduction plate (heat conduction plate assembly 10 ) is applicable to an isolation case 3 enclosing a heat source 40 . In this embodiment, the heat source 40 is an electronic component arranged on a circuit board 4 , (such as a processor, a power transistor, etc.) The isolation case 3 is composed of an isolation casing 31 surrounding the heat source 40 and an isolation cover 32 mated with upper side of the isolation casing 31 to cover the heat source 40 . The contact face 101 of the heat conduction plate (heat conduction plate assembly 10 ) is in contact with the isolation case 3 . An electroconductive adhesive layer is disposed between the isolation case 3 (isolation cover 32 ) and the contact face 101 of the heat conduction plate (heat conduction plate assembly 10 ), whereby the relevant components are more securely electrically connected with each other (for grounding or other purposes).
[0031] The heat spreader 2 is a plate-shaped structure body with an area smaller than that of the heat conduction plate assembly 10 (heat conduction plate). The heat spreader 2 can be made of graphite or the like material. In this embodiment, the heat spreader 2 is an elongated plate body, which has a property of quickly conducting heat along the surface (transversely). The heat spreader 2 is attached to and in contact with the heat conduction plate assembly 10 (heat conduction plate). In practice, the heat spreader 2 can be an electrical conductor. An electroconductive adhesive layer 20 can be disposed between the heat spreader 2 and the heat conduction plate assembly 10 (heat conduction plate) as necessary, whereby the heat spreader 2 and the heat conduction plate assembly 10 (heat conduction plate) are electrically connected with each other. The heat spreader 2 has a proximal-to-heat-source section 21 proximal to the heat source 40 and a distal-from-heat-source section 22 extending in a direction away from the heat source 40 .
[0032] In use, most of the heat generated by the heat source 40 is conducted from the isolation case 3 through the contact face 101 to the heat conduction plate assembly 10 (heat conduction plate). The heat conduction plate assembly 10 (heat conduction plate) is made of metal material and is able to uniformly radially spread the heat at equal speed. Therefore, the heat can quickly pass through the heat conduction plate assembly 10 (heat conduction plate) and be transferred to the heat spreader 2 . Then, due to the property of quickly conducting heat along the surface (transversely) of the heat spreader 2 , the heat is quickly spread from the proximal-to-heat-source section 21 proximal to the heat source 40 to the distal-from-heat-source section 22 distal from the heat source 40 . Then the heat is outward dissipated from the heat conduction plate assembly 10 (heat conduction plate) without accumulating around the isolation case 3 . In this case, the temperature of the isolation case 3 will not locally abnormally rise. Also, the heat conduction plate assembly 10 (heat conduction plate) and the heat spreader 2 are electrically connected with each other and grounded via the isolation case 3 .
[0033] In the above heat dissipation structure of the present invention, the heat spreader 2 is disposed on one face of the heat conduction plate assembly 10 (heat conduction plate), which face is distal from the isolation case 3 (heat source 40 ). However, in practice, alternatively, the heat spreader 2 can be disposed on one face of the heat conduction plate assembly 10 (heat conduction plate), which face is proximal to the heat source 40 or even in direct contact with the isolation case 3 (heat source 40 ). This can achieve the same heat dissipation effect.
[0034] Please now refer to FIG. 4 , which shows a second embodiment of the present invention. The second embodiment includes a heat spreader 6 and a heat conduction plate assembly 10 identical to that of the first embodiment. The heat conduction plate assembly 10 is in contact with and assembled on the isolation case 3 (isolation cover 32 ) in the same manner as the first embodiment. The heat spreader 6 is a plate-shaped structure body disposed on one side of the heat conduction plate assembly 10 (heat conduction plate). An electroconductive adhesive layer can be disposed between the heat conduction plate assembly 10 (heat conduction plate) and the heat spreader 6 as necessary. The heat spreader 6 has an elongated main extension section 61 and multiple branch sections 62 obliquely extending from one side of the main extension section 61 in parallel to each other. The branch sect ions 62 obliquely extend in a direction away from the heat source 40 and the main extension section 61 . The main extension section 61 has a proximal-to-heat-source section 611 proximal to the heat source 40 and a distal-from-heat-source section 612 extending in a direction away from the heat source 40 .
[0035] In use, most of the heat generated by the heat source 40 is conducted from the isolation case 3 through the contact face 101 to the heat conduction plate assembly 10 (heat conduction plate). The heat spreader 6 then quickly spreads the heat to those sections that are distal from the heat source 40 (to the distal-from-heat-source section 612 of the main extension section 61 and to the free ends of the branch sections 62 ). Then the heat is outward dissipated from the heat conduction plate assembly 10 (heat conduction plate) without accumulating around the isolation case 3 . Also, the heat conduction plate assembly 10 and the heat spreader 6 can be electrically connected to a grounding section of the circuit board 4 via the isolation case 3 .
[0036] In practice, as necessary, the heat spreader 6 can be disposed on one face of the heat conduction plate assembly 10 (heat conduction plate), which face is distal from the heat source 40 or disposed on one face of the heat conduction plate assembly 10 (heat conduction plate), which face is proximal to the heat source 40 . Both can achieve the same heat dissipation effect.
[0037] Please now refer to FIG. 5 , which shows a third embodiment of the present invention. The third embodiment includes a heat spreader 5 and a heat conduction plate assembly 10 identical to that of the first embodiment. The heat conduction plate assembly 10 is in contact with and assembled on the isolation case 3 (isolation cover 32 ) in the same manner as the first embodiment. The heat spreader 5 is a plate-shaped structure body disposed on one side of the heat conduction plate assembly 10 (heat conduction plate). An electroconductive adhesive layer can be disposed between the heat conduction plate assembly 10 (heat conduction plate) and the heat spreader 6 as necessary. The heat spreader 5 has an elongated main extension section 51 and multiple branch sections 52 , 53 obliquely extending from two sides of the main extension section 51 in parallel to each other. The branch sections 52 , 53 obliquely extend in a direction away from the heat source 40 and the main extension section 51 . The main extension section 51 has a proximal-to-heat-source section 511 proximal to the heat source 40 and a distal-from-heat-source section 512 extending in a direction away from the heat source 40 .
[0038] In use, most of the heat generated by the heat source 40 is conducted from the isolation case 3 through the contact face 101 to the heat conduction plate assembly 10 (heat conduction plate). The heat spreader 5 then quickly spreads the heat to those sections that are distal from the heat source 40 (to the distal-from-heat-source section 512 of the main extension section 51 and to the free ends of the branch sections 52 , 53 ). Then the heat is conducted back to the heat conduction plate assembly 10 (heat conduction plate) and outward dissipated from the heat conduction plate assembly 10 (heat conduction plate) without accumulating around the isolation case 3 .
[0039] In practice, as necessary, the heat spreader 5 can be disposed on one face of the heat conduction plate assembly 10 (heat conduction plate), which face is distal from the heat source 40 or disposed on one face of the heat conduction plate assembly 10 (heat conduction plate), which face is proximal to the heat source 40 . Both can achieve the same heat dissipation effect.
[0040] Please now refer to FIGS. 6 and 7 , which show a fourth embodiment of the present invention. The fourth embodiment includes a heat conduction plate assembly 1 and a heat spreader 2 identical to that of the first embodiment. The heat conduction plate assembly 1 includes two heat conduction plates 11 , 12 (made of metal material) with electroconductivity. A contact face 121 is formed on a face of the heat conduction plate 12 , which face is distal from the heat conduction plate 11 . (Alternatively, the contact face can be formed on a face of the heat conduction plate 11 , which face is distal from the heat conduction plate 12 ). In practice, the heat conduction plate assembly 1 is applicable to an isolation case 3 enclosing a heat source 40 as in the first embodiment. In this embodiment, the contact face 121 of the heat conduction plate assembly 1 is in contact with the isolation case 3 (the isolation cover 32 ). An electroconductive adhesive layer is disposed between the isolation case 3 (isolation cover 32 ) and the contact face 121 of the heat conduction plate assembly 1 , whereby the relevant components are more securely electrically connected with each other (for grounding or other purposes).
[0041] The heat spreader 2 is a plate-shaped structure body with an area smaller than that of the heat conduction plate assembly 1 (heat conduction plates 11 , 12 ). The heat spreader 2 can be made of graphite or the like material. The heat spreader 2 is disposed between the heat conduction plates 11 , 12 and attached to and in contact with the heat conduction plates 11 , 12 . In this embodiment, the heat spreader 2 is an elongated plate body, which has a property of quickly conducting heat along the surface (transversely). The heat spreader 2 can be an electrical conductor. Electroconductive adhesive layers 20 can be disposed between the heat spreader 2 and the heat conduction plates 11 , 12 as necessary, whereby the heat spreader 2 and the heat conduction plates 11 , 12 are electrically connected with each other. The heat spreader 2 has a proximal-to-heat-source section 21 proximal to the heat source 40 and a distal-from-heat-source section 22 extending in a direction away from the heat source 40 .
[0042] In use, most of the heat generated by the heat source 40 is conducted from the isolation case 3 through the contact face 121 to the heat conduction plate 12 of the heat conduction plate assembly 1 . The heat conduction plate 12 is made of metal material and is able to uniformly radially spread the heat at equal speed. Therefore, the heat can quickly pass through the heat conduction plate 12 and be transferred to the heat spreader 2 . Then, due to the property of quickly conducting heat along the surface (transversely) of the heat spreader 2 , the heat is quickly spread from the proximal-to-heat-source section 21 proximal to the heat source 40 to the distal-from-heat-source section 22 distal from the heat source 40 . Then the heat is conducted from the heat spreader 2 to the heat conduction plates 11 , 12 and outward dissipated from the heat conduction plates 11 , 12 without accumulating around the isolation case 3 . In this case, the temperature of the isolation case 3 will not locally abnormally rise. Also, the heat conduction plates 11 , 12 and the heat spreader 2 are electrically connected with each other and grounded via the isolation case 3 .
[0043] Please now refer to FIG. 8 , which show a fifth embodiment of the present invention. The fifth embodiment includes a heat conduction plate assembly 1 and a heat spreader 6 identical to that of the second embodiment. The heat conduction plate assembly 1 includes two heat conduction plates 11 , 12 (made of metal material) with electroconductivity. A contact face 121 is formed on a face of the heat conduction plate 12 , which face is distal from the heat conduction plate 11 . (Alternatively, the contact face can be formed on a face of the heat conduction plate 11 , which face is distal from the heat conduction plate 12 ). In practice, the heat conduction plate assembly 1 is applicable to an isolation case 3 enclosing a heat source 40 as in the first embodiment. In this embodiment, the contact face 121 of the heat conduction plate assembly 1 is in contact with the isolation case 3 (the isolation cover 32 ). An electroconductive adhesive layer is disposed between the isolation case 3 (isolation cover 32 ) and the contact face 121 of the heat conduction plate assembly 1 , whereby the relevant components are more securely electrically connected with each other (for grounding or other purposes).
[0044] The heat spreader 6 is a plate-shaped structure body disposed between the heat conduction plates 11 , 12 . (Electroconductive adhesive layers can be disposed between the heat spreader 6 and the heat conduction plates 11 , 12 as necessary). The heat spreader 6 has an elongated main extension section 61 and multiple branch sections 62 obliquely extending from one side of the main extension section 61 in parallel to each other. The branch sections 62 obliquely extend in a direction away from the heat source 40 and the main extension section 61 . The main extension section 61 has a proximal-to-heat-source section 611 proximal to the heat source and a distal-from-heat-source section 612 extending in a direction away from the heat source 40 .
[0045] In use, most of the heat generated by the heat source 40 is conducted from the isolation case 3 through the contact face 121 to the heat conduction plate 12 . The heat spreader 6 then quickly spreads the heat to those sections that are distal from the heat source 40 (to the distal-from-heat-source section 612 of the main extension section 61 and to the free ends of the branch sections 62 ). Then the heat is conducted back to the heat conduction plates 11 , 12 and outward dissipated from the heat conduction plates 11 , 12 without accumulating around the isolation case 3 .
[0046] Please now refer to FIG. 9 , which show a sixth embodiment of the present invention. The sixth embodiment includes a heat conduction plate assembly 1 and a heat spreader 5 identical to that of the third embodiment. The heat conduction plate assembly 1 includes two heat conduction plates 11 , 12 (made of metal material) with electroconductivity. A contact face 121 is formed on a face of the heat conduction plate 12 , which face is distal from the heat conduction plate 11 . (Alternatively, the contact face can be formed on a face of the heat conduction plate 11 , which face is distal from the heat conduction plate 12 ). In practice, the heat conduction plate assembly 1 is applicable to an isolation case 3 enclosing a heat source 40 as in the first embodiment. In this embodiment, the contact face 121 of the heat conduction plate assembly 1 is in contact with the isolation case 3 (the isolation cover 32 ). An electroconductive adhesive layer is disposed between the isolation case 3 (isolation cover 32 ) and the contact face 121 of the heat conduction plate assembly 1 , whereby the relevant components are more securely electrically connected with each other (for grounding or other purposes).
[0047] The heat spreader 5 is a plate-shaped structure body disposed between the heat conduction plates 11 , 12 . Electroconductive adhesive layers can be disposed between the heat spreader 5 and the heat conduction plates 11 , 12 as necessary. The heat spreader 5 has an elongated main extension section 51 and multiple branch sections 52 , 53 obliquely extending from two sides of the main extension section 51 in parallel to each other. The branch sections 52 , 53 obliquely extend in a direction away from the heat source 40 and the main extension section 51 . The main extension section 51 has a proximal-to-heat-source section 511 proximal to the heat source and a distal-from-heat-source section 512 extending in a direction away from the heat source 40 .
[0048] In use, most of the heat generated by the heat source 40 is conducted from the isolation case 3 through the contact face 121 to the heat conduction plate 12 . The heat spreader 5 then quickly spreads the heat to those sections that are distal from the heat source 40 (to the distal-from-heat-source section 512 of the main extension section 51 and to the free ends of the branch sections 52 , 53 ). Then the heat is conducted back to the heat conduction plates 11 , 12 and outward dissipated from the heat conduction plates 11 , 12 without accumulating around the isolation case 3 .
[0049] In conclusion, the heat dissipation structure of electronic shield cover of the present invention can quickly and uniformly dissipate the heat to avoid accumulation of the heat. Moreover, the heat dissipation structure of electronic shield cover of the present invention is manufactured at lower cost.
[0050] The above embodiments are only used to illustrate the present invention, not intended to limit the scope thereof. Many modifications of the above embodiments can be made without departing from the spirit of the present invention.
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A heat dissipation structure of electronic shield cover, which is applicable to a heat-conductive and magnetically conductive isolation case that encloses a preset heat source for dissipating heat. The heat dissipation structure includes: an electroconductive heat conduction plate assembly having at least one contact face in contact with a surface of the isolation case; and a heat spreader, which is able to transversely conduct heat. The heat spreader has an area smaller than that of the heat conduction plate assembly and is disposed on the heat conduction plate assembly in contact therewith. The heat spreader has a proximal-to-heat-source section proximal to the heat source and a distal-from-heat-source section extending in a direction away from the heat source. The heat conduction plate assembly and the heat spreader cooperate with each other to quickly dissipate the heat and avoid accumulation of the heat around the heat source.
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BACKGROUND AND SUMMARY OF THE INVENTION
The present invention relates to a protector bar that is adapted to deflect away from the lock or handle of a door objects that pass through the open doorway or are pushed into the door to open it.
It is a common occurrence in many facilities for an individual pushing a cart or other mobile object to pass through a closed doorway by forcing the cart into the door to deflect it open. When this is done, the cart typically strikes the knob or handle protruding from the door which, if repeated often enough, can damage both the door and handle. In hospitals, for example, it is common practice for patients, medicine, and equipment to be transported through doorways in this manner, especially in emergency situations. This of course can, over a period of time, result in substantial damage to doors, door locks and handles, thus giving rise to significant maintenance expenses. In many such facilities, metal coverings are placed over the impact areas on the surface of the door to minimize the damage to the door. However, these measures do nothing to protect the door locks and handles.
The present invention alleviates these problems by providing a protector bar that is designed to protect not only the lock or handle from being struck by a cart or other moving object, but also to deflect and distribute the impact of the cart to minimize damage to the door. The protector bar according to the present invention essentially comprises an integral bar having a deflector portion and a projection portion. The protector bar is intended to be fastened horizontally to the door with the projection portion adjacent to the lock or handle of the door. When mounted, the deflector portion of the bar extends at an acute angle from the surface of the door, and the projection portion extends perpendicular from the door a distance at least as great as the distance the lock or handle protrudes from the door. The edge of the deflector portion where it fastens to the door is beveled so that objects striking the door will not catch on the end of the protector bar. In addition, the deflector end of the bar has a flat mounting pad that sits flush against the surface of the door and serves to distribute the impact of an object striking the bar. Similarly, a mounting plate is fastened to the projection end of the bar flush with the surface of the door to displace the impact at that end of the bar.
As will subsequently be described in greater detail, the size and shape of the protector bar can be readily modified for particular applications on different types of doors. For example, the length of the bar can be expanded to protect a glass area on a door, or the shape of the bar can be slightly modified to properly protect various types of lever door handles.
Other objects and advantages of the present invention will become apparent from a reading of the following detailed description of the preferred embodiments which makes reference to the following set of drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a view of the protector bar according to the present invention;
FIG. 2 is another view of the protector bar shown in FIG. 1;
FIG. 3 is an illustration of a typical application of the protector bar shown in FIG. 1;
FIG. 4 is a plan view of a modified version of the protector bar according to the present invention;
FIG. 5 is an illustration of one of the preferred manners of mounting the protector bar to a door;
FIG. 6 is a sectional view of the door illustrated in FIG. 5 taken along the line 6--6;
FIG. 7 is an illustration of another preferred manner of mounting the protector bar to a door;
FIG. 8 is a sectional view of the door illustrated in FIG. 7 taken along line 8--8;
FIG. 9 illustrates a modified form of the protector bar; and
FIG. 10 illustrates another modified form of the protector bar.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a detailed view of the protector bar 10 according to the present invention is shown. The preferred embodiment of the protector bar 10 is manufactured from 3/8 inch × 11/2 inches stainless steel stock. However, it is to be understood that other suitable materials possessing similar properties of rigidity, relative low cost, ease of manufacture, and pleasing appearance, could also be used. Stainless steel is preferred because it can typically be finished to match the other hardware on the door.
The protector bar 10 according to the present invention comprises a deflector portion 12 and a projection portion 14. As can best be seen in FIG. 2, the deflector portion 12 forms an acute angle relative to the plane of the door 30 when the bar 10 is mounted. As is more fully illustrated in the subsequent figures, the angle of the bar is designed to deflect carts and other objects away from the protruding lock or handle of the door. In addition, the angle of the bar serves to deflect the force of a cart striking the bar, thereby reducing the impact on the door. The deflector end of the bar 10 has a flat section 16, referred to as a mounting pad, that is used to secure that end of the bar 10 to the door 30. The back side 22 of the mounting pad 16 is flat so that it will lay flush against the surface of the door 30. It will be noted, that the mounting pad 16 is internally threaded at 24 from the back surface 22, so that there will be no protruding screw head on the exposed surface of the mounting pad 16 to mar objects that come in contact with the bar 10. Additionally, the edge of the mounting pad 16 is beveled at 20 so that objects striking the surface of the door will not catch on the edge of the bar 10. It is to be understood, that the term "beveled" is intended to include a somewhat rounded edge as illustrated in the drawings.
The projection end of the bar 10 is fastened to a mounting plate 18 by a pair of machine screws 28. Alternatively, the mounting plate 18 may simply be welded to the end of the bar 10. In addition to providing a convenient surface for mounting the bar 10 to the door 30, the mounting plate 18 also serves to distribute over the surface of the door the impact of an object striking the bar 10. It will further be noted that the mounting pad 16 at the opposite end of the bar 10 also serves the same function of displacing the force of an object striking the bar 10. The size of the mounting plate 18, can of course, be varied according to the particular application involved. However, a 2 inch square stainless steel plate has been found to be adequate for most purposes. The mounting plate 18 illustrated in FIGS. 1 and 2 is adapted to be fastened to the door 30 by four wood screws 26. However, depending upon the particular construction of the door, a set of bolts 25 extending through the door may also be used.
In addition, where the bar 10 is mounted to a hollow-core door, for example, it may be desirable to include a supporting bar 29 constructed of material similar to the bar, to be mounted to the opposite side of the door 30 by the same through bolts 25 and 27 to which the bar 10 is secured, to provide added support for the bar 10 and increase the integrity of the door.
Referring now to FIG. 3, one of the preferred manners of mounting the protector bar 10 of the present invention to a door 30 is shown. As the diagram illustrates, the bar 10 is mounted to the door 30 in horizontal alignment with the handle 32 of the door. The projection end of the bar 10 is mounted sufficiently close to the handle 32, without obstructing its use to open the door 10, so that objects striking the bar 10 will be deflected over the handle 32. Importantly, it will be noted that the projection portion 14 of the bar 10 protrudes from the plane of the door 30 a greater distance than the handle 32. Returning momentarily to FIG. 2, it will be appreciated that the length of the projection portion 14 must be such that the apex 15 of the bar 10 extends a greater distance from the surface of the door 30 than the protruding piece of hardware on the door 30 which the bar 10 is intended to protect.
Looking to FIGS. 5 and 6, the function of the protector bar 10 is illustrated. In particular, it can be seen that when a cart or other object 36 is pushed into the door 30, it will strike the deflector portion 12 of the bar 10, thereby causing the door 30 to swing open. Due to the angle of the deflector portion 12 of the bar 10, the force of the impact of the cart 36 striking the door is diminished. In addition, the mounting pad 16 and plate 18 associated with the bar 10 serve to displace the force of the impact over a greater surface area of the door 30. Furthermore, it can be seen that as the door 30 is opened against the urging of the cart 36 riding along the length of the deflector portion 12 of the bar 10, the cart 36 will be sufficiently spaced from the surface of the door 30 when it reaches the apex 15 of the bar 10 to pass over the handle 32 without being caught thereon. Thus, the cart 36 can pass through the doorway substantially unimpeded by the door 30 or the door handle 32 protruding therefrom.
Referring now to FIGS. 7 and 8, an alternative manner of mounting the protector bar 10 according to the present invention is shown. The protector bar 10 in this application is horizontally mounted slightly below the handle 32 of the door. As before, the bar 10 is sufficiently spaced from the handle 32 to permit someone to grip the handle 32 to open the door 10. In addition, the bar 10 is mounted so that the apex 15 of the bar 10 is substantially vertically aligned with the door handle 32. In this manner, a cart 36 striking the bar 10 will avoid being caught on the handle 32 of the door 30. The mounting procedure illustrated in FIGS. 7 and 8 is particularly appropriate in situations where the door is stiffly hinged. Specifically, it will be appreciated that with the mounting procedure illustrated in FIGS. 5 and 6, the corner of the cart 36 may nonetheless catch on the handle 32 after it passes the bar 10 if the door 30 is stiffly hinged. The procedure illustrated in FIGS. 7 and 8 eliminates the possibility of this occurring. Accordingly, for such applications, the later alternative is preferred. However, in applications where the doors are typically maintained in the open position and the primary concern is preventing objects passing through the open doorway from striking the protruding door handle, it will be appreciated that either mounting procedure will work equally well.
Referring to FIGS. 9 and 10, additional applications of the protector bar 10 according to the present invention are shown. When mounted to doors 30 containing glass panes 38 and 40, the size of the protector bar 10 may be explained by lengthening the deflector portion 12 so that the bar 10 spans the glass area. When utilized in this manner, the bar 10 provides the additional function of protecting the glass 38 and 40 in the door 30 from breakage or other damage.
Turning now to FIG. 4, an alternative design of the protector bar is illustrated. The protector bar 10' shown in FIG. 4 is an example of a type of design modification which can be made to the bar to adapt it to a particular application. On doors having lever types handles 34 as shown, it can be seen that the embodiment of the protector bar 10 illustrated in the other figures may not completely protect the lever handle 34 from objects striking the bar. In particular, due to the inclination of the deflector portion 12 of the bar 10 illustrated in FIGS. 1 and 2, the lever handle 34 would protrude beyond the bar 10 if mounted in the manner illustrated in FIGS. 7 and 8. Thus, a cart could still catch on the handle 34 notwithstanding the presence of the protector bar 10. Consequently, for this type of application, the modified version of the protector bar 10' shown in FIG. 4 can be utilized. The protector bar 10' in this embodiment comprises a projection portion 14' and a deflector portion 12' as in the previous embodiment, however, an additional straight segment 13 is added between the deflector portion 12' and the projection portion 14'. The straight segment 13 of the bar 10' is designed to parallel the lever handle 34 so that no part of the handle 34 extends beyond the bar 10'. Thus, the handle 34 is completely protected from impact by an object striking the bar 10'.
It is to be understood, that other modifications to the design of the protector bar as described herein to adapt the bar to various other applications are possible without departing from the basic concepts of the present invention.
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Disclosed is a protector bar that is adapted to be fastened to a door adjacent the lock or handle of the door to prevent the lock or handle from being damaged by objects, such as carts or tables, that pass through the doorway or are pushed into the door to open it. The protector bar essentially comprises a deflector portion which fastens to the face of the door and extends therefrom at an acute angle relative to the plane of the door, and a projection portion integral to the deflector portion that is fastened adjacent the handle of the door and extends perpendicular from the surface of the door a distance slightly greater than the distance the handle protrudes from the door.
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FIELD OF THE INVENTION
[0001] The present invention generally relates to electronic circuits. More particularly, the invention concerns a start-up circuit.
BACKGROUND OF THE INVENTION
[0002] The Information Age is upon us. Access to vast quantities of information through a variety of different communication systems is changing the way people work, entertain themselves, and communicate with each other. Faster, more capable communication technologies are constantly being developed. For the manufacturers and designers of these new technologies, achieving low power consumption is becoming an increasingly difficult challenge. Low power consumption is important as it directly affects the battery life of portable electronic devices.
[0003] The wireless device industry, which includes portable devices, has recently seen unprecedented growth. With the growth of this industry, communication between wireless devices has become increasingly important. There are a number of different technologies for inter-device communications. Radio Frequency (RF) technology has been the predominant technology for wireless device communications. Alternatively, electro-optical devices have been used in wireless communications. Electro-optical technology suffers from low ranges and a strict need for line of sight. RF devices therefore provide significant advantages over electro-optical devices.
[0004] Conventional RF technology employs continuous sine waves that are transmitted with data embedded in the modulation of the sine waves' amplitude or frequency. For example, a conventional cellular phone must operate at a particular frequency band of a particular width in the total frequency spectrum. Specifically, in the United States, the Federal Communications Commission has allocated cellular phone communications in the 800 to 900 MHz band. Generally, cellular phone operators divide the allocated band into 25 MHz portions, with selected portions transmitting cellular phone signals, and other portions receiving cellular phone signals
[0005] Another type of communication technology is ultra-wideband (UWB). UWB technology can be fundamentally different from conventional forms of RF technology. One type of UWB employs a “carrier free” architecture, which does not require the use of high frequency carrier generation hardware; carrier modulation hardware; frequency and phase discrimination hardware or other components employed in conventional frequency domain communication systems.
[0006] Within UWB communications, several different types of networks, each with their own communication protocols are envisioned. For example, there are Local Area Networks (LANs), Personal Area Networks (PANs), Wireless Personal Area Networks (WPANs), sensor networks and others. Each network may have its own communication protocol.
[0007] Most of these forms of communications can be implemented in portable electronic devices. In these types of devices, power consumption and therefore battery life is of significant importance. In a number of technologies, high data rate devices are relatively power consumptive. However, the desire high data rate communication between portable devices directly conflicts with an equal desire for extended battery life. One approach is conservation, which requires the shutdown non-critical circuits when they are not in use. A significant drawback to this approach is the time necessary to restart the circuit when it is needed.
[0008] Therefore, there exists a need for a fast shutdown and start-up circuit for electronics contained within portable, and other types of electronic devices.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] Various embodiments of the present invention taught herein are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings, in which:
[0010] FIG. 1 is an illustration of different communication methods;
[0011] FIG. 2 is an illustration of two ultra-wideband pulses;
[0012] FIG. 3 depicts the current United States regulatory mask for outdoor ultra-wideband communication devices;
[0013] FIG. 4A illustrates transmit and receive frames and the guard time between the frames;
[0014] FIG. 4B illustrates power-up time periods prior to transmission and reception of the frames illustrated in FIG. 4A .
[0015] FIG. 5 illustrates a conventional circuit comprising a current source and current mirrors;
[0016] FIG. 6 illustrates a circuit consistent with one embodiment of the present invention;
[0017] FIG. 7 illustrates a circuit consistent with another embodiment of the present invention;
[0018] FIG. 8A illustrates a timing diagram of a conventional electronic circuit; and
[0019] FIG. 8B illustrates a timing diagram of a circuit constructed according to the present invention.
[0020] It will be recognized that some or all of the Figures are schematic representations for purposes of illustration and do not necessarily depict the actual relative sizes or locations of the elements shown. The Figures are provided for the purpose of illustrating one or more embodiments of the invention with the explicit understanding that they will not be used to limit the scope or the meaning of the claims.
DETAILED DESCRIPTION OF THE INVENTION
[0021] In the following paragraphs, the present invention will be described in detail by way of example with reference to the attached drawings. While this invention is capable of embodiment in many different forms, there is shown in the drawings and will herein be described in detail specific embodiments, with the understanding that the present disclosure is to be considered as an example of the principles of the invention and not intended to limit the invention to the specific embodiments shown and described. That is, throughout this description, the embodiments and examples shown should be considered as exemplars, rather than as limitations on the present invention. Descriptions of well-known components, methods and/or processing techniques are omitted so as to not unnecessarily obscure the invention. As used herein, the “present invention” refers to any one of the embodiments of the invention described herein, and any equivalents. Furthermore, reference to various feature(s) of the “present invention” throughout this document does not mean that all claimed embodiments or methods must include the referenced feature(s).
[0022] The present invention provides a novel start-up circuit for communications devices. In one embodiment of the present invention comprises a capacitor that is charged by a current source. The current source is mirrored to provide a larger current to charge a larger capacitor. One feature of this embodiment is that the larger capacitor provides stability to the circuit while the time required to bring the circuit to an operational point is reduced.
[0023] The present invention circuit is particularly useful, but not limited to, applications in portable electronics devices where minimal power consumption is desired. Some forms of portable electronics may employ one, or more wireless communication technologies. One type of communication technology is ultra wideband (UWB). One embodiment of the present invention contemplates a portable communication device that employs UWB technology. This embodiment may employ a “burst” communication mode, because data rates achievable using UWB may exceed the portable devices' capacity to process the data. In this application, the UWB-enabled portable device may transmit at a very high data rate for a short period of time (i.e., “burst”) then shut down, to conserve power and battery life. In this embodiment, rapid start-up circuits may help to minimize power consumption.
[0024] The embodiments of the present invention discussed below may be used with ultra-wideband (UWB) communication technology, as well as other forms of communication technology. Referring to FIGS. 1 and 2 , impulse-type UWB communication employs discrete pulses of electromagnetic energy that are emitted at, for example, nanosecond or picosecond intervals (generally tens of picoseconds to a few nanoseconds in duration). For this reason, this type of ultra-wideband is often called “impulse radio.” That is, impulse-type UWB pulses may be transmitted without modulation onto a sine wave, or a sinusoidal carrier, in contrast with conventional carrier wave communication technology. Impulse-type UWB may operate in virtually any frequency band and in some applications may not require the use of power amplifiers.
[0025] An example of a conventional carrier wave communication technology is illustrated in FIG. 1 . IEEE 802.11a is a wireless local area network (LAN) protocol, which transmits a sinusoidal radio frequency signal at a 5 GHz center frequency, with a radio frequency spread of about 5 MHz. As defined herein, a carrier wave is an electromagnetic wave of a specified frequency and amplitude that is emitted by a radio transmitter in order to carry information. The 802.11 protocol is an example of a carrier wave communication technology. The carrier wave comprises a substantially continuous sinusoidal waveform having a specific narrow radio frequency (5 MHz) that has a duration that may range from seconds to minutes.
[0026] In contrast, an ultra-wideband (UWB) pulse may have a 2.0 GHz center frequency, with a frequency spread of approximately 4 GHz, as shown in FIG. 2 , which illustrates two typical impulse-type UWB pulses. FIG. 2 illustrates that the shorter the UWB pulse in time, the broader the spread of its frequency spectrum. This is because bandwidth is inversely proportional to the time duration of the pulse. A 600-picosecond UWB pulse can have about a 1.8 GHz center frequency, with a frequency spread of approximately 1.6 GHz and a 300-picosecond UWB pulse can have about a 3 GHz center frequency, with a frequency spread of approximately 3.3 GHz. Thus, UWB pulses generally do not operate within a specific frequency, as shown in FIG. 1 . In addition, either of the pulses shown in FIG. 2 may be frequency shifted, for example, by using heterodyning, to have essentially the same bandwidth but centered at any desired frequency. And because UWB pulses are spread across an extremely wide frequency range, UWB communication systems allow communications at very high data rates, such as hundreds of Mega-bits per second or greater, including Giga-bits per second.
[0027] Several different methods of ultra-wideband (UWB) communications have been proposed. For wireless UWB communications in the United States, all of these methods must meet the constraints recently established by the Federal Communications Commission (FCC) in their Report and Order issued Apr. 22, 2002 (ET Docket 98-153). Currently, the FCC is allowing limited UWB communications, but as UWB systems are deployed, and additional experience with this new technology is gained, the FCC may revise its current limits and allow for expanded use of UWB communication technology.
[0028] The FCC April 22 Report and Order requires that UWB pulses, or signals must occupy greater than 20% fractional bandwidth or 500 Mega-Hertz of radio frequency, whichever is smaller. Fractional bandwidth is defined as 2 times the difference between the high and low 10 dB cutoff frequencies divided by the sum of the high and low 10 dB cutoff frequencies. Specifically, the fractional bandwidth equation is:
Fractional Bandwidth = 2 f h - f l f h + f l
[0029] where f h is the high 10 dB cutoff frequency, and f l is the low 10 dB cutoff frequency.
[0030] Stated differently, fractional bandwidth is the percentage of a signal's center frequency that the signal occupies. For example, a signal having a center frequency of 10 MHz, and a bandwidth of 2 MHz (i.e., from 9 to 11 MHz), has a 20% fractional bandwidth. That is, center frequency, f c =(f h +f l )/2
[0031] FIG. 3 illustrates the ultra-wideband emission limits for indoor systems mandated by the April 22 Report and Order. The Report and Order constrains UWB communications to the frequency spectrum between 3.1 GHz and 10.6 GHz, with intentional emissions to not exceed −41.3 dBm/MHz. The report and order also establishes emission limits for hand-held UWB systems, vehicular radar systems, medical imaging systems, surveillance systems, through-wall imaging systems, ground penetrating radar and other UWB systems. It will be appreciated that the invention described herein may be employed indoors, and/or outdoors, and may be fixed, and/or mobile, and may employ either a wireless or wire media for a communication channel.
[0032] Additionally, the International Telecommunications Union Task Group 1/8 (ITU-TG 1/8) is currently debating ITU recommendations for UWB communications. In some countries the regulations adopted for UWB communications will differ from the FCC definition, but should be similar in nature. For example, the Japanese Ministry of Internal Affairs and Communications (MIC) is currently debating the allowance of UWB in Japan. In this debate one proposal is to allow UWB communications in two frequency bands, one from 3.4 GHz to 4.8 GHz, the other from 7.25 GHz to 10.6 GHz. ITU proposals submitted by the European Conference of Postal and Telecommunications Administration (CEPT) would allow UWB transmission only above 6 GHz. A definition of UWB therefore may not be limited to specific frequency bands employed.
[0033] Generally, in the case of wireless communications, a multiplicity of UWB signals may be transmitted at relatively low power density (Milli-Watts per Mega-Hertz). However, an alternative UWB communication system, located outside the United States, may transmit at a higher power density. For example, UWB signals may be transmitted between 30 dBm to −50 dBm.
[0034] Communication standards committees associated with the International Institute of Electrical and Electronics Engineers (IEEE) are considering a number of ultra-wideband (UWB) wireless communication methods that meet the constraints established by the FCC. One UWB communication method may transmit UWB pulses that occupy 500 MHz bands within the 7.5 GHz FCC allocation (from 3.1 GHz to 10.6 GHz). In one embodiment of this communication method, UWB pulses have about a 2-nanosecond duration, which corresponds to about a 500 MHz bandwidth. The center frequency of the UWB pulses can be varied to place them wherever desired within the 7.5 GHz allocation. In another embodiment of this communication method, an Inverse Fast Fourier Transform (IFFT) is performed on parallel data to produce 122 carriers, each approximately 4.125 MHz wide. In this embodiment, also known as Orthogonal Frequency Division Multiplexing (OFDM), the resultant UWB pulse, or signal is approximately 506 MHz wide, and has approximately 242-nanosecond duration. It meets the FCC rules for UWB communications because it is an aggregation of many relatively narrow band carriers rather than because of the duration of each pulse.
[0035] Another UWB communication method being evaluated by the IEEE standards committees comprises transmitting discrete UWB pulses that occupy greater than 500 MHz of frequency spectrum. For example, in one embodiment of this communication method, UWB pulse durations may vary from 2 nanoseconds, which occupies about 500 MHz, to about 133 picoseconds, which occupies about 7.5 GHz of bandwidth. That is, a single UWB pulse may occupy substantially all of the entire allocation for communications (from 3.1 GHz to 10.6 GHz).
[0036] Yet another UWB communication method being evaluated by the IEEE standards committees comprises transmitting a sequence of pulses that may be approximately 0.7 nanoseconds or less in duration, and at a chipping rate of approximately 1.4 Giga pulses per second. The pulses are modulated using a Direct-Sequence modulation technique, and is known in the industry as DS-UWB. Operation in two bands is contemplated, with one band is centered near 4 GHz with a 1.4 GHz wide signal, while the second band is centered near 8 GHz, with a 2.8 GHz wide UWB signal. Operation may occur at either or both of the UWB bands. Data rates between about 28 Mega-bits/second to as much as 1,320 Mega-bits/second are contemplated.
[0037] Another method of UWB communications comprises transmitting a modulated continuous carrier wave where the frequency occupied by the transmitted signal occupies more than the required 20 percent fractional bandwidth. In this method the continuous carrier wave may be modulated in a time period that creates the frequency band occupancy. For example, if a 4 GHz carrier is modulated using binary phase shift keying (BPSK) with data time periods of 750 picoseconds, the resultant signal may occupy 1.3 GHz of bandwidth around a center frequency of 4 GHz. In this example, the fractional bandwidth is approximately 32.5%. This signal would be considered UWB under the FCC regulation discussed above.
[0038] Thus, described above are four different methods of ultra-wideband (UWB) communication. It will be appreciated that the present invention may be employed by any of the above-described UWB methods, or others yet to be developed. One characteristic of UWB communications is the bandwidth occupied by UWB signals is very large and the data rates are very high. Traditionally, high data rate wireless devices consume more power than lower data rate devices. This characteristic makes it difficult to design circuits for portable electronic applications where battery life is an important consideration. Many electronic devices that employ conventional, or UWB communication technology can benefit from the circuits disclosed herein.
[0039] Specific embodiments of the invention will now be further described by the following, non-limiting examples which will serve to illustrate various features. The examples are intended merely to facilitate an understanding of ways in which the invention may be practiced and to further enable those of skill in the art to practice the invention. Accordingly, the examples should not be construed as limiting the scope of the invention.
[0040] The present invention is useful in any electronic circuit, and especially in electronic circuits where accelerated start-up times are desired. In a preferred embodiment, the circuits described herein are employed in portable wireless communication devices. The present invention is particularly useful in portable communication devices that employ UWB communication technology. For example, some applications foreseen for a portable communication device that employs UWB communication technology may be a mode where the portable device bursts at a high data rate and then either shuts down, or “sleeps” for a time period. For example, in many wireless portable devices, the data processing capability of the device may be substantially lower than the data rate capability provided by the UWB communication technology. When transferring a file from one portable device to another or from a portable device to any other type of device, it may be advantageous to transmit at a very high rate, and then shut down while the receiving device processes the received data.
[0041] Referring now to FIG. 4A , in communication systems that use “fames” to transmit data, there may be breaks between the transmission and/or reception of frames. For example, a transmitting device may transmit a frame (Tx Frame), and then have a guard period (tguard) before receiving a frame (Rx Frame). These time periods are usually negotiated or assigned by a common communication protocol running within each device. During the Tguard time a device may power down some portion of its circuitry in order to save power and extend battery life.
[0042] However, as shown in FIG. 4B , in some instances the power-up time period before transmission can be initiated (t 2 -t 1 ) and the power-up time period required before the receiver can be started (t 4 -t 3 ) can comprise a significant time period. These power-up periods limit the amount of time a device can remain in a low power state. Therefore, it is advantageous to minimize the start-up time of the transmit and receive circuits. One advantage of the present invention is that by minimizing a circuits' start-up time, the guard time intervals (tguard) may be reduced. In some applications, such as portable devices the guard time intervals may allow for a “power down” mode. In devices where battery life is not a significant issue, the reduced start-up time may allow for higher data throughput by placing frames closer together in time.
[0043] Referring now FIG. 5 , which illustrates a portion of an electronic circuit usually used for generating biasing currents in transistor circuits. In steady state operation reference current Iref flows through transistor Q 1 and is mirrored in transistors Q 3 -QN. Transistor Q 2 provides base current for Q 1 and Q 3 -QN. Capacitor C 1 is provided for bypassing the bias voltage at the base of transistor Q 2 and to ensure the stability of the negative feedback loop through Q 2 and Q 1 . In shut down state both switches (S 1 and S 2 ) are ON (i.e., closed). S 1 short circuits Iref to ground. S 2 ensures short circuiting of any reverse collector-base current produced in Q 3 -QN, which may be present as a result of avalanche carrier multiplication in the collector-base region. The circuit is started by turning OFF switches S 1 , S 2 (i.e., open, as shown). One limitation of this circuit, in terms of start-up time is the time to charge capacitor C 1 . Upon start-up, a portion of current Iref provides the charge to capacitor C 1 . The charge time may be modeled as
Δ t = Δ v * C 1 Iref
where Δv is the voltage increase on the capacitor, C 1 is the capacitance of the capacitor, and Iref is the current charging the capacitor. The charging time is therefore dependent on the current charging the capacitor and on the size, or capacitance of the capacitor. That is, the higher the capacitance, and the smaller the charging current, the longer it takes to charge.
[0044] One embodiment of the present invention, illustrated in FIG. 6 , shows an accelerated start-up circuit. In this embodiment, capacitor C 2 is selected to have a capacitance N times smaller than capacitor C 1 , where N is number larger than 1. When the circuit illustrated in FIG. 6 is in a low-power or OFF state, the ON signal is low. The ON signal is inverted by inverter INV 1 to provide a high signal to transistors M 1 , M 2 , and M 3 . In an ON state, M 2 provides a path for any leakage current to reach the lower voltage level gnd. In like manner transistor M 1 provides a path for Iref to reach the lower voltage level gnd., and M 3 keeps capacitor C 2 short-circuited.
[0045] When start-up of the circuit is initiated, the ON signal goes high and remains high during normal operation of the circuit. The ON signal turns on transistor M 4 , which allows current i C2 to charge capacitor C 2 . INV 1 provides a low potential to signal NEN, which turns off transistors M 3 , M 1 , and M 2 . The current mirror circuit that includes transistors M 5 and M 6 is designed to provide a current icrg to charge capacitor C 1 . This current mirror circuit may be designed to multiply current i C2 by the same factor N, allowing the larger capacitor C 1 to charge faster. It is anticipated that the relative capacitance of C 1 is N times larger than C 2 . Once capacitors C 1 and C 2 have achieved complete charge, the current flow through those capacitors goes to zero. This effectively places M 4 , ic 2 , M 5 , and M 6 , in a “zero” or negligible current state. The charge on capacitor C 1 provides bias voltages and stability to the remaining current sources Iref 1 to Irefn in a similar manner as described above with reference to FIG. 5 .
[0046] Embodiments of the present invention start up circuit, ensures that the voltage produced on C 1 (VC 1 ) during accelerated startup matches the steady state value. If the voltage across C 1 exceeds its steady state value, Iref overshoot may result. The steady state voltage VC 1 is defined as: V C1 =V be2 +V be1 +I ref R 1 . An I2V replica with a comparator on M 7 and M 8 biased by 17 are employed. Iref/M current flows through I2V replica. M may be any number greater or equal to 1. As the transistors in I2V replica circuit are also scaled down by M, the voltage produced on source of M 7 matches VC 1 in steady state operation. When ON goes to high, C 2 is charged by i C2 . When the voltage on the source of M 8 matches the voltage on source of M 7 , i C2 reduces down to 17 (in case of equal size of M 7 and M 8 ). Further voltage VC 2 increasing stops as the current stops to flow when M 8 switches OFF. The charge on C 2 created by i C2 is N times less than necessary for C 1 to be charged to VC 1 . The current mirror on M 5 and M 6 multiplies i C2 N times to obtain i crg feeding into C 1 and producing VC 1 matching that in steady state operation.
[0047] One feature of this embodiment of the present invention is that by using capacitor C 2 and its associated circuit, the charge time of capacitor C 1 is reduced to that of capacitor C 2 . One advantage of using a small capacitor for C 2 is that the current i C2 can be relatively small, minimizing power consumption during start-up. Additionally, fabrication of capacitor C 2 will occupy substantially smaller space than a larger capacitor.
[0048] Referring now to FIG. 7 , which illustrates another embodiment of the present invention. The charge on capacitor C 1 provides bias voltages and stability to the remaining current sources Iref 1 to Irefn in a similar manner as described above with reference to FIG. 5 . A voltage amplifier with Kv=1 provides a low impedance node for accelerated charging of C 2 . When this embodiment is in the low power state the ON signal is low and switch S 1 is in the position as shown. In this state capacitor C 2 is allowed to charge to a voltage approximately equal to Vref. The ON signal is inverted by inverter INV 1 , which provides a high signal NEN to turn on transistors M 1 and M 2 . Transistors M 1 and M 2 provide a current path for Iref and any leakage currents to reach a lower voltage state gnd. When start-up is desired the ON signal goes high which places switch S 1 in the alternate position. The charged capacitor C 2 provides the charge to capacitor C 1 through current amplifier Ki. Similar to the circuit in FIG. 6 , the capacitance of C 1 is N times larger than the capacitance of capacitor C 2 , and the gain of current amplifier Ki is N, where N is a number larger than 1. In this state, the inverter INV 1 provides a low to turn off transistors M 1 and M 2 , thereby removing the path to the lower voltage state gnd. When capacitor C 1 reaches a charged state, it provides bias voltages and stability to the current mirror stages Iref 1 through Irefn.
[0049] Referring now to FIGS. 8A and 8B , which illustrate the differences in transition times between circuits not employing the present invention and ones incorporating the present invention. In FIG. 8A , the timing diagram 10 shows that following the transition of the ON signal, current Iref is charging capacitor C 1 . During time period t d1 the voltage Vc 1 across capacitor C 1 increases until it reaches a complete charge at voltage level Vref. Current provided by current source Iref 1 is delayed in time until capacitor C 1 has reached a level to provide proper bias voltage to the circuit. This is contrasted with FIG. 8B , which illustrates timing diagram 20 , that is representative of a circuit employing the present invention.
[0050] In timing diagram 20 when the ON signal transitions to a high state, the charging currents i C1 and i C2 are substantially higher than Iref in timing diagram 10 . It is important to note that charging current i C1 is N times larger than charging current i C2 . The larger currents i C1 and i C2 provide for faster charge times for capacitors C 1 and C 2 . This results in VC 1 reaching an operational state of Vref in a much shorter time period t d2 . At this operational state current source Iref 1 and associated current mirrors will reach operational readiness in time period t d2 instead of t d1 .
[0051] Thus, it is seen that an apparatus for acceleration of start-up of electronic circuits is provided. One skilled in the art will appreciate that the present invention can be practiced by other than the above-described embodiments, which are presented in this description for purposes of illustration and not of limitation. The specification and drawings are not intended to limit the exclusionary scope of this patent document. It is noted that various equivalents for the particular embodiments discussed in this description may practice the invention as well. That is, while the present invention has been described in conjunction with specific embodiments, it is evident that many alternatives, modifications, permutations and variations will become apparent to those of ordinary skill in the art in light of the foregoing description. Accordingly, it is intended that the present invention embrace all such alternatives, modifications and variations as fall within the scope of the appended claims. The fact that a product, process or method exhibits differences from one or more of the above-described exemplary embodiments does not mean that the product or process is outside the scope (literal scope and/or other legally-recognized scope) of the following claims.
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A start-up circuit for electronic circuits is provided. In one embodiment, the circuit uses a smaller capacitor and a current amplification means to force a larger capacitor to reach a charged state in a reduced time. The present invention is useful in any type of electronic circuit where fast start-up times are desirable. The present invention is especially useful in portable electronics, such as wireless communication devices, where minimal power consumption is desired. This Abstract is provided for the sole purpose of complying with the Abstract requirement rules that allow a reader to quickly ascertain the subject matter of the disclosure contained herein. This Abstract is submitted with the explicit understanding that it will not be used to interpret or to limit the scope or the meaning of the claims.
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BACKGROUND OF THE INVENTION
1. Field of The Invention
Applicant's invention relates to a purified natural zeolite pigment composition for filling and/or coating paper. More particularly, the present invention relates to a purified natural zeolite pigment composition that can be used for coating paper that produces a paper that exhibits improved characteristics over existing uncoated and coated papers made with other pigments.
2. Background Information
Pigments are used in papermaking and paper coating to improve the appearance, optical properties and printability of papers. Commonly used pigments include kaolin clay, calcium carbonate, titanium dioxide, alumina trihydrate and polystyrene. These pigments are useful in manufacture of conventional printing and writing papers and paperboards that are printed or imaged by common processes including offset lithography, gravure and xerography. Recently developed imaging technology has created needs for new types of coated and uncoated papers with properties not achievable with conventional pigments. Ink jet printing is a useful example.
Ink jet printing technology has undergone several changes in addressing the demands of existing and future digital printing applications that require high quality printed images. High quality ink jet printing typically occurs on coated paper; therefore, to produce such high quality printed images the coating composition and the ink formulation must be considered.
Current ink jet papers rely on the novel properties of the coating material to create desired properties to dry and set the ink solutions. Jet inks typically contain 2.5% by weight of organic dyes. The dye is fixed to the paper surface either by evaporation of a base such as ammonia, by migration of a base such as diethanolamine into the paper, or by changes in ionic environment when the ink meets the coating material layer.
The paper must exhibit unique properties in order to produce a high quality printed image when the ink is fixed to the paper surface. Once the ink drop is accepted by the paper, the ink must adhere to the paper and spread minimally in all directions to generate sharp edges for print contrast 1 and image fidelity. The paper must be smooth to give high print densities 2 . In addition, the paper should minimize bleeding 3 and wicking while promoting the absorption of ink to set the dye onto the coated surface since this promotes higher print densities. Ink jet droplets must be adsorbed quickly to avoid image smearing and multiple drop splatter. The dyes should be deposited near the paper surface to maximize color density and contrast while minimizing show through 4 .
1 Contrast is defined as the tonal change in color from light to dark.
2 Density is defined as the degree of color or darkness of an image.
3 Bleeding is defined as ink traveling into the sheet.
4 Show through is defined as printing that is visible from the backside of a sheet, or the next sheet, under normal lighting conditions.
Coating, which generally contains pigment, binders, and additives, is applied to the paper surface to improve the properties of the paper. The ink interacts with the coating to produce a high quality image. The coating prevents the ink from penetrating into the substrate. More specifically, the coating can optimize drying time for high water content dyes and separate the water-soluble organic dyes from the water vehicle and hold the dye on the surface so it doesn't strike through to the base sheet. Smoothness and thickness of the coating layer are two important physical properties that impact print quality. Pore structure and contact angle wettability effect print quality by preventing ink spreading. In order to prevent wicking and feathering 5 , it is important that the thickness of the coating layer be homogenous to a scale of a few microns in depth which also helps in the absorption of successive droplets of ink at high delivery rates and any water present.
5 Feathering is defined as the spreading of ink at the edges of printed type, caused by irregularities in the ink or its distribution.
Paper made for ink jet printing should have a hydrophilic, high porosity surface with no macroscopic structure in order to absorb ink jet droplets quickly with little spreading, wicking or dye penetration. Therefore the preferred coating for the paper surface should contain a highly porous, high surface area pigment that wets almost instantly with water. If the coating has sufficient thickness and void volume, it should be able to absorb successive droplets in multicolor printing at the highest delivery rates of commercial ink jet printing. The dye should react with the coating material to make it waterfast and rub resistant. The coating should have near neutral or alkaline pH to avoid shifts from the intended color of the dyes.
The rate of ink penetration has a large effect on final optical density through its effect on drying time and setting of the dye on the coated surface. The rate of ink penetration can be explained by the Lucas Washburn Equation of capillary flow:
I 2 =γr (cos θ) t/ 4 v
where I is the depth of ink penetration, r is the pore radius, t is time, γ is the surface tension, θ is the contact angle, and v is the viscosity of the ink. In generating high print quality, the rate of ink penetration must be modified to allow sufficient wetting to occur. The hydrophilic/hydrophobic surface chemistry of the coating plays an important role in the development of image quality through the control of dot gain. Sufficient dot gain requires the dot spreading on a smooth surface and is a function of contact angle. The contact angle is itself a function of the interactions between the surface tension of the liquid, surface vapor, and liquid vapor interfaces. The determination of sufficient dot gain can be characterized through the surface tension of the interfaces from Young's equation:
γ slv =γ si +γ iv cos θ
This equation evaluates the development of the contact angle which controls spread of liquid through the surface tensions involved. If the contact angle is less than 90 degrees, surface roughness will reduce the contact angle even more. Whereas if the contact angle is greater than 90 degrees the surface roughness will increase the contact angle. Porosity also effects the measured contact angle.
The interactions between ink and the coated substrate play a vital role in producing images that are long lasting, well defined and of high strength regardless of printer application. The main interaction occurs at the surface of the substrate, where the type of bonding that occurs between the colorant and the media dictates the final print quality. The interactions that take place between the colorant and the plain paper are controlled by hydrogen bonding and Van der Waals forces, while ionic and electrostatic forces are responsible for the interactions between the colorant and the coated paper.
Hydrogen bonding is the most significant bonding that takes place between color and media, where cellulosic material is involved. For a large dye molecule, a large number of sites are available for hydrogen bonding which encourage the interaction between the colorant and the media. Hydrogen bonding between color and media increases the strength of the color binding on the media. Furthermore, the hydroxyl groups of the cellulose may interact with the δ cloud of an aromatic group on the colorant by hydrogen bonding.
Van der Waals forces are very weak when the interacting groups are far apart and a weak repulsion typically exists between the media and anionic dyes. The interaction between colorant and media becomes strong as the dyes start penetrating into the base sheet.
Electrostatic forces occur due to coloumbic attraction. The cationic groups on the media, such as Ti 3+ , Al 3+ , and Ca 2+ attract anionic dyes, such as water-soluble groups of SO 3 2− , COO − , and PO 4 3− . The result is strong attraction between these groups, which causes an effective immobilization of the dye molecules, resulting in excellent print quality.
The δ—δ interactions are very strong interactions that typically occur between dye molecules. These interactions normally generate either dye aggregation or crystallization 6 . If dye—dye interactions on the paper substrate are stronger than dye-paper interactions, dye may aggregate on the substrate causing printing problems. Thus a strong interaction between colorant and media is required.
6 Crystallization is a condition in which a dried ink film repels a second ink film repels a second ink which must be printed on top of it.
Hydrogen bonding and Van der Waals forces are the main interactions that occur in plain papers. Plain papers mainly consist of cellulose and therefore the main interactions are between the color and the cellulose. The penetration of color into the substrate will be controlled by capillary adsorption. If the paper has been internally or surface sized the rate of penetration of the colorant will be decreased which may lead to some ink bleeding and feathering problems.
The interaction of the colorant with coated paper is different however. The selection of the coating and ink formulation will have a significant effect on the ink absorption rate, image quality, and water/light fastness properties of the liquid ink. Electrostatic or ionic interactions play the key role in colorant coated paper interactions. Electrostatic interaction is stronger than hydrogen bonding and Van der Waals interactions. These interactions are more efficient, as the colorant is fixed in the vicinity where it was printed. The nature of the anionic dyes and the oxides will determine the print quality of ink jet printing since electrostatic interactions of the colorant with coated media occur between the anionic groups of the dyes and oxides. The binding energies of the dyes are greatly increased by electrostatic interactions resulting in high bonding strength.
Existing coated ink jet papers are mainly dependent on amorphous and gelled silica, which possess high micro porosity and macro porosity. The porous coating structure provides the driving force for the rapid diffusion of ink liquid into the coating layer and internal pore volume of the coating for storing large amounts of ink. These two properties interact to set the anionic dye at or near the coating surface, generating higher optical printing densities. The high surface area of the silica requires a strong binder to maintain adhesion to the paper and cohesion within the coating structure. Therefore, polyvinyl alcohol, the strongest binder available, is used.
Unfortunately, the current use of silica and polyvinyl alcohol has several limitations that effect the coating. The internal porosity of the silica pigments and the degree of hydrolysis of the polyvinyl alcohol limits running the coating solids at 20%. Silica pigments pose production problems and high cost because they must be coated at relatively slow speeds. Coating solids level is a major limiting factor with silica pigments because of viscosity, water absorption, and drying issues. Silica slurries alone do not usually flow well at levels above 15 to 20% solids, so dispersants are used to increase their concentrations. Also, silica has a great affinity for water given its high pore volume so it forms a paste as water is added until all the voids are filled. Only then is it fluid enough for the coating formulation. This behavior decreases the vehicle available for the slurry, so formulators must start at a lower solids concentration. The absorbed water in the pores also demands extra energy during drying. Calcium carbonate is another material sparingly used for ink jet printer coatings that dry similar to silica, but its surface area and void volume are much lower than silica—resulting in inferior image quality. It is also abrasive and can exhibit poor coater runnability. Its use is limited to cast coated ink jet papers for glossy photo prints where it is used as a supplementary pigment to silica.
With the compositions for coating paper currently on the market higher quality coated ink jet papers must be coated off-machine and are not cost effective. Producing a paper sheet with the desired properties is difficult due to the need to find ways to coat ink jet paper on-machine at commercial speeds with no loss in quality. The preferred finished ink jet paper should be smooth, strong, opaque, bright, and able to handle the demands of ink jet printing while providing excellent print results, such as excellent ink adherence, high scratch and ink resistance, and bleed control for sharp edges. It was therefore necessary to develop the composition for coating paper of the present invention that produces a coated paper that overcomes the disadvantages of the existing art while presenting a high print quality image at a reduced cost. More specifically, the present invention contemplates substituting a zeolite pigment for silica in matte ink jet coating formulations.
A zeolite pigment that possesses the desirable combination of brightness, color, particle size distribution, surface area, internal void volume, rheology and hardness could also be useful in overcoming the limitations of conventional and other specialty pigments in various papermaking and paper coating applications including but not limited to: (1) toner bond improvement in laser and other dry toner imaged digital papers; (2) elimination of smudging and improvement of print quality in direct print flexography on coated linerboard used in corrugated containers; (3) elimination of print through on newsprint and ultra light weight coated papers; (4) improvement of dot fidelity and print quality on coated rotogravure printing papers; (5) low abrasion extender for titanium dioxide pigments; (6) improvement of coefficient of friction of paper and paperboard; (7) production of technical specialty papers such as anti-tarnish, gas filtration, and absorbent papers with improved properties and lower cost of manufacture; (8) more economical microparticulate retention system chemistry; (9) additive to improve the efficiency of deinking systems.
Zeolites are crystalline, hydrated aluminosilicates of the alkali and alkaline earth metals. More particularly, zeolites are framework silicates consisting of interlocking tetrahedrons of SiO 4 and AlO 4 . In order to constitute a zeolite the ratio of silicon and aluminum to oxygen must be ½. The alumino-silicates structure is negatively charged and attracts the positive cations that reside within. When exposed to higher charged ions of a new element, zeolites will exchange the lower charged element contained within the zeolite for a higher charged element. Unlike most other tectosilicates, zeolites have large vacant spaces or cages in their structures that allow space for large cations such as sodium, potassium, barium, and calcium and relatively large molecules and cationic molecules, such as water, ammonia, carbonate ions, and nitrate ions. In most useful zeolites, the spaces are interconnected and form long wide channels of varying sizes depending on the mineral. These channels allow ease of movement of the resident ions and molecules into and out of the structure.
Zeolites are characterized by 1) a high degree of hydration, 2) low density and large void volume when dehydrated, 3) stability of the crystal structure of many zeolites when dehydrated, 4) uniform molecular sized channels in the dehydrated crystals, 5) ability to absorb gases and vapors, 6) catalytic properties, and 7) cation exchange properties.
The use of natural zeolites in paper making has a long history, but has been almost unique to Japan where zeolite has been used as filler to improve bulkiness and printability. Natural zeolites have also been used as fillers for paper in Hungary. These natural zeolites however are a low brightness material and this renders it unsatisfactory for application in the United States on coated ink jet paper where high brightness is expected.
Numerous families of natural zeolites exist and each has varying characteristics. Unfortunately, natural zeolites exhibit nonuniform properties that makes them difficult to work with in many applications because ores from one location can vary with any other. It is however possible to manufacture zeolites with uniform properties. The preferred zeolite for use in the present invention is a processed form of the natural mineral clinoptilolite which is a hydrated sodium potassium calcium aluminum silicate having the formula (Na, K, Ca) 2-3 Al 3 (Al,Si) 2 Si 13 ) 36 —12H 2 O. This zeolite is within the family Heulandite that also includes the mineral heulandite which is a hydrated sodium calcium aluminum silicate. The physical characteristics of raw clinoptilolite are listed in Table 1.
TABLE 1
PHYSICAL CHARACTERISTICS OF CLINOPTILOLITE
Color is colorless, white, pink, yellow, reddish and pale brown.
Luster is vitreous to pearly on the most prominent pinacoid face and on
cleavage surfaces.
Transparency: Crystals are transparent to translucent.
Crystal System is monoclinic; 2/m.
Crystal Habits include blocky or tabular crystals with good monoclinic
crystal form. More tabular and proportioned than heulandite. Also
commonly found in acicular (needle thin) crystal sprays.
Cleavage is perfect in one direction parallel to the prominent pinacoid
face.
Fracture is uneven.
Hardness is 3.5-4, maybe softer on cleavage surfaces.
Specific Gravity is approximately 2.2
Streak is white.
Clinoptilolite's structure is sheet like with a tectosilicate structure where every oxygen is connected to either a silicon or an aluminum ion (at a ratio of [Al+Si]/O=½). The sheets are connected to each other by a few bonds that are relatively widely separated from each other. The sheets contain open rings of alternating eight and ten sides. These rings stack together from sheet to sheet to form channels throughout the crystal structure. The size of these channels controls the size of the molecules or ions that can pass through them. Clinoptilolite is well suited for various applications, such as in paper coating compositions, because it exhibits large pore space, high resistance to extreme temperatures, and has a chemically neutral structure.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a novel purified natural zeolite pigment for coated ink jet papers and digital printing papers to replace silica pigments.
Another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a specialty coating pigment in coated linerboard for direct post print flexography to prevent smudging and to improve image fidelity.
Still another object of the present invention is to provide a novel purified natural zeolite pigment that can act as a supplementary coating pigment in ultra lightweight coated publication papers.
It is yet another object of the present invention to provide a novel purified natural zeolite pigment that can act as a supplementary coating pigment for water based gravure 7 printing papers.
7 Gravure printing is a method of printing using etched metal cylinders.
An additional object of the present invention is to provide a novel purified natural zeolite pigment that can replace calcined kaolin as a titanium dioxide extender in coated recycled paperboard and coated solid unbleached sulfate (SUS) beverage carrier stock.
It is still another object of the present invention to provide a novel purified natural zeolite pigment that can act as filler in newsprint to prevent print-through.
It is yet another object of the present invention to provide a novel purified natural zeolite pigment that can act as filler in specialty technical papers such as anti-tarnish, gas filtration, filter, and absorbent papers.
Another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a microparticulate retention aid.
Still another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a deinking aid in combination flotation-washing systems.
Yet another object of the present invention is to provide a novel purified natural zeolite pigment that can be used as a coefficient of friction (COF) control aid in recycled linerboard.
Another object of the present invention is to provide a novel purified natural zeolite pigment for use in a coating composition that has improved rheology compared to silica and other specialty pigments.
Still another object of the present invention is to provide a novel purified natural zeolite pigment for use in a coating composition that improves coater runnability.
It is yet another object of the present invention to provide a novel purified natural zeolite pigment for use in a coating composition that has decreased energy consumption in drying.
It is an object of the present invention to provide a novel composition for coating paper that has water slurries with a higher percentage of solids and good shear thinning rheology compared to existing compositions.
Another object of the present invention is to provide a novel composition for coating paper that has higher coating formulation solids compared to existing compositions.
Still another object of the present invention is to provide a novel composition for coating paper that has enhanced on-machine coating run ability and therefore enhanced production rates over existing compositions.
It is yet another object of the present invention to provide a novel composition for coating paper that has low Einlehner abrasion which results in reduced wear to process equipment and no metallic marks are left on the paper by the gripper bars.
Another object of the present invention is to provide a novel composition for coating paper that has a low bulk density.
Still another object of the present invention is to provide a novel composition for coating paper that has faster on-machine drying rates because of higher percent solid coatings than existing compositions which results in lower drying costs and reduced print smear.
Yet another object of the present invention is to provide a novel composition for coating paper that has a low crystalline silica content.
It is another object of the present invention to provide a novel composition for coating paper that coats with essentially no dusting.
It is still another object of the present invention to provide a novel composition for coating paper that has improved first pass retention in paper machine trials compared to existing compositions.
Another object of the present invention is to provide a novel composition for coating paper that has improved optical/reflective densities of four-color cyan, magenta, yellow, black (CMYK) ink jet print.
An additional object of the present invention is to provide a novel composition for coating paper that makes lighter coat weights possible because of higher internal void volume.
Still another object of the present invention is to provide a novel composition for coating paper with a slightly basic pH.
Yet another object of the present invention is to provide a novel composition for coating paper that has a high brightness of 90% or more.
Another object of the present invention is to provide a novel composition for coating paper that has a narrow particle size distribution with few fines.
An additional object of the present invention is to provide a novel composition for coating paper that improves ink jet print density.
It is yet another object of the present invention to provide a novel composition for coating paper that improves ink receptivity in printing papers.
Still another object of the present invention is to provide a novel composition for coating paper that has improved opacity.
An additional object of the present invention is to provide a novel composition for coating paper that has less soak-in and reduced roughening of the base sheet during application which results in a smoother coated sheet.
Another object of the present invention is to provide a novel composition for coating paper that allows higher operating speeds and higher production rates.
It is still an additional object of the present invention to provide a novel composition for coating paper that has the capability to coat on high speed paper machines rather than only on low speed off machine coating lines which reduces waste and costs.
In satisfaction of these and related objectives, Applicant's present invention provides a purified natural zeolite pigment composition for coating and/or filling of paper. Applicant's invention permits its practitioner to manufacture coated paper for use in ink jet printers that exhibits improved characteristics over existing uncoated and coated papers such as high print quality images and reduced cost. It also permits the practitioner to make other specialty and technical papers that exhibit quality and economic advantages over papers made with existing technology and commercially available materials.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a graph of the dynamic contact angle versus time in seconds for coating compositions both with and without the zeolite pigment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The processed zeolite used in the present invention has several specific characteristics as indicated in Table 2.
TABLE 2
Characteristics of Zeolite Pigment Samples
Zeolite Pigment
Zeolite Pigment
Specification
Sample 1
Sample 2
GE Brightness 8 %
94+
90+
L 9
98.46
98.00
a
0.43
0.44
b
1.25
1.72
Yellowness Index
2.48
2.05
Particle Size μ, <D90
2.0
2.0
Einlehner Abrasion, mg loss
12
18
Loose Density, lbs./cu. ft.
8
8
Packed Density, lbs./cu. ft.
12
12
Refractive Index
1.48
1.48
Surface Area, sq. m./g.
40-50
40-50
Oil Absorption, lbs./100 lbs.
70-80
70-80
Density, g/cc
2.2
2.2
pH in Water
5.0
8.5
Cation Exchange Capacity
1.6-1.8
1.8-2.0
Brookfield Viscosity, 20 rpm @
1000
cPs
1000
cPs
40% solids*
Hercules Viscosity @
1
dyne
1
dyne
1100 rpm*
*Nonoptimized dispersion in water
8 GE Brightness is a directional brightness measurement utilizing essentially parallel beams of light with a wavelength of 457 nm to illuminate the paper surface at an angle of 45°. It is also referred to as TAPPI Brightness. GE or TAPPI Brightness is the value obtained by TAPPI Test method T646 om-94 “Brightness of Clay and Other Mineral Pigments” (45 degrees/0 degrees).
9 L, a, b values are the chromacity coordinates or color values of paper or paperboard measures with tristimulus filter colorimeters or spectrophotometers incorporating direction (45°/0°) geometry and CIE (International Commission on Illumination) illuminant C. “L” represents lightness, increasing from zero for black to 100 for white; “a” represents redness
# when plus, greenness when minus and zero for gray; “b” represents yellowness when plus, blueness when minus, and zero for gray. This is referred to as TAPPI Test Method T 524 om-94 “Color of Paper and Paperboard (45°/0° Geometry).”
In evaluating the usefulness of the present zeolite, its material properties were tested. The first step was to determine whether the zeolite pigment could be dispersed using commonly available dispersants.
The colorants used in aqueous ink jet printer inks are anionic. A cationic material is used along with the pigment to fix the printed image to the paper. It is most desirable that an ink jet pigment be dispersible with a cationic dispersant with the dispersant providing dual functionality in the coating. The standard cationic dispersant for silica ink jet coatings is poly-dimethyl-diallyl ammonium chloride (DMDAAC) which has a common usage rate of 5% on dry pigment.
Evaluation of dispersants was done by adding a pre-weighed amount of pigment (enough to yield a 50% solids dispersion) to water under high shear using a Cowles Dissolver™ disperser. 10 The pigment was added slowly to the water until the viscosity of the pigment began to substantially increase. This occurred around the 46% solids point. The dispersant being evaluated was then added to drop the viscosity, and the remainder of the pigment was added. Samples of the pigment dispersion were taken for Brookfield viscosity and Hercules high-shear rheology testing. The final solids content was determined by oven drying a sample of the pigment dispersion.
10 Cowles Dissolver™ is the trade name for an open rotor high shear mixer-dispenser manufactured by Morehouse-Cowles Corp., Fullerton, Calif.
The present zeolite was successfully dispersed with 5% DMDAAC to provide 50.7% slurry solids with Brookfield viscosity of 414 cPs at 100 rpm with a No.4 spindle. The 20-rpm viscosity at 50.7% solids was 1520 cPs. The lower viscosity at 100 rpm indicates that the present zeolite pigment has a shear thinning rheology which is highly desirable for application on blade, rod, and metering size press coaters. With silica pigments, such as Grace-Davison's Sylojet™, J. M. Huber's Optisil™ or ICI Crosfield's Gasil®, use of 5% DMDAAC provides dispersion at <30% maximum solids. The lower solids of silica dispersions severely limit application solids for formulated coating colors. Silica pigments are also known to be dilatant or shear thickening, which causes running problems on blade and rod coaters. The rheology of silica pigments makes it impractical to run them in on-machine metering size press coatings at solids content high enough to prevent soak-in and binder migration. Hercules high-shear rheograms of the present zeolite pigment confirmed that the present pigment provides rheology suitable for good coater runnability and sheet surface quality.
For use in applications other than ink jet printing—for example as an adjunct pigment in coating formulations including kaolin clay, calcium carbonate and titanium dioxide—it is desirable that the zeolite pigment be dispersible with a standard dispersant used for conventional pigments. The present zeolite was also successfully dispersed with 2% AMP-95™ (2-amino, 2-methyl, 1-propanol) 11 to provide a stable dispersion at 50.34% solids with Brookfield viscosity of 470 cPs at 100 rpm with a No. 4 spindle. The 20-rpm viscosity at 50.34% solids was 1680 cPs. Hercules high-shear rheograms showed the AMP-95™ zeolite dispersion to be thixotropic and shear thinning—desirable rheology for paper and paperboard coating.
11 AMP-95™ (2-amino, 2-methyl, 1-propanol), a commercial dispersant manufactured by Angus Chemical Company, Buffalo Grove, Ill.
Drawdowns 12 of pure dispersed zeolite pigment of the present invention on a 76.6% brightness base sheet gave 86.0% GE brightness.
12 A drawdown is a coating chemist's method of coating a small sheet of paper for testing purposes. A bead of pigment slurry or coating is placed on the paper and drawn down with a wire wound rod which provides uniform volumetric metering onto the sheet surface. Coat weight per unit area is controlled by the choice of wire winding i.e. larger or small grooves for the coating to flow between adjacent wire grooves.
Drawdowns were made with various ratios of pigment to PVOH (polyvinyl alcohol) binder to determine the CPVC. 13 The CPVC was found to be 50%, that is a pigment to binder ratio of 1:1.
13 CPVC (Critical Pigment Volume Concentration) is the pigment volume concentration at which the binder just fills the volume between pigment particles.
Dusting was also evaluated. Dusting 14 (sometimes called “rub off” or “chalking” is a major potential problem with ink jet papers made with silica pigments. Many coaters find that they must add polyvinyl pyrolidone (PVP) to control dusting. Drawdowns were made with the present zeolite and polyvinyl alcohol at pigment binder ratios up to 14:1 to evaluate the dusting potential. No PVP was added. The present zeolite pigment coatings did not dust at pigment to binder ratios up to 14:1, which provides a significant performance advantage.
14 Dusting occurs when the coating pigment particles are not adequately bound to one another and/or the sheet surface. Coating pigment particles are easily dislodged from the coated sheet surface by rubbing and/or when the coated sheet is folded, slit, or die cut. Airvol® 203 is a partially hydrolyzed (87.0-89.0% hydrolysis) polyvinyl alcohol produced by Air Products and Chemicals, Inc. Allentown, Pa.
The results showed that the present processed zeolite pigment could act as an ink jet coating pigment.
Laboratory coating formulation experiments were performed to determine the viscosity at highest obtainable coating solids. The present zeolite was dispersed with 5% DMDAAC at 50.7% solids. A 30% solution of Airvol® 203 PVOH 15 was prepared by dispersing the granules in cold water, heating to 85° C. and holding at 85° C. for 30 minutes. The dispersed zeolite slurry and PVOH solutions were blended to obtain pigment to binder ratios of 2:1, 4:1, 6:1 and 8:1 with no dilution water added.
Viscosity determination of the coating formulations was made using a Brookfield RVT viscometer with a #5 spindle. The data obtained from these experiments is contained in Table 3a and can be compared to data from three major suppliers of silica pigments as contained in Table 3b and to data from Engelhard™ regarding a modified kaolin based pigment as contained in Table 3c.
TABLE 3a
Brookfield Viscosity of Zeolite Formulations
Pigment:Binder Ratio
% Coating Solids
20 rpm
100 rpm
2:1
40.17
4000
1750
4:1
41.87
5400
1972
6:1
43.09
6760
2100
8:1
45.93
7880
2368
TABLE 3b
Coating Formulation Solids Content from Silica Suppliers' Data
Sheet and/or the sheet surface. Coating pigment particles are easily
dislodged from the coated sheet surface by rubbing and/or when the
coated sheet is folded, slit, or die cut.
Airvol ® 203 is a partially hydrolyzed (87.0-89.0% hydrolysis)
polyvinyl alcohol produced by Air Products and Chemicals, Inc.
Allentown, PA.
Supplier
Grace-Davison
J. M. Huber
ICI Crosfield
Product
Sylojet ™
Optisil ™
Gasil □
Pigment:Binder Ratio
2.49:1
1.00-1.67:1
2.5:1
% Solids
18.4
14-18
18
TABLE 3c
Coating Solids Recommendation from Engelhard Data Sheet
Supplier
Engelhard
Product
Digitex ™
Pigment:Binder Ratio
2.5:1
Coating % Solids
30 to 33%
As can be seen from these data, the present zeolite pigment provides coating color solids more than twice as high as any of the currently used silica pigments. It provides coating solids 21% higher than the highest coating solids claimed from the Engelhard Digitex™ hybrid kaolin pigment. The present zeolite pigment provides shear-thinning rheology to facilitate application by blade, rod, or metering size press coaters. The higher solids attainable with the zeolite pigment of the present invention provide substantial operating benefits to producers of ink jet papers including less soak in and reduced roughening of the base sheet during application resulting in a smoother coated sheet, improved coater runnability, decreased energy consumption in drying, higher operating speeds and higher production rates and capability to coat on high speed paper machines rather than only on low speed off machine coating lines which reduces waste and costs.
Test printing of the drawdowns on Canon and Epson ink jet printers showed that density improved as the pigment to binder ratio was decreased from 8:1 to 2:1. At 2:1 pigment to binder ratio, the present zeolite pigment drawdowns came close to the value for commercial papers Weyerhaeuser Satin Ink Jet™ and International Paper Great White™ Premium Matte Ink Jet Paper. The commercial papers had been produced on full-scale machinery with optimized formulations and calendered to improve performance. Due to these results, it was determined that pilot coating trials should be performed.
The zeolite of the present invention was evaluated as a coating pigment and filler with an emphasis on coating ink jet papers as a replacement for silica. For the pilot coating, Cylindrical Laboratory Coater (CLC) trials were performed. The CLC 16 is a laboratory device that simulates coating at commercial machine speeds while consuming only small amounts of coating materials. It provides not only coated paper samples for evaluation, but also indications of runnability in commercial production. The coating experiments were performed using the zeolite of the present invention as the sole pigment with polyvinyl alcohol binder at varying pigment to binder ratios. More specifically, the experimental design used was based on E-Chip using the following parameters: 1) pigment: binder ratios of 2:1, 5:1, and 8:1; 2) polyvinyl alcohol types from Air Products™ including Airvol® 103 (fully hydrolyzed 98.0-98.8% hydrolysis) and Airvol® 203 (partially hydrolyzed 87.0-89.0% hydrolysis); 3) Amp 95™ and DMDAAC as dispersants; 4) coat weights of 6, 9 and 12 grams/square meter; 5) 23 combinations of conditions; and 6) 29 total runs. The CLC trials were run at 2500-3600 feet/minute. Blade metering was done with 0.015-inch thick coating blade and a 0.018-inch thick backing blade using a 0.4-inch extension. The results of these trials are indicated in Table 4.
16 The Cylindrical Laboratory Coater is manufactured by Sensor & Simulation Products, a division of Weyerhaeuser Co., Tacoma, Wash.
TABLE 4
Results of Cylindrical Laboratory Coater (CLC) Pilot Trials
Pigment:binder ratio
PVOH
Speed
Runnability/Coverage
2:1
203
2000
Excellent
2:1
203
2500
Excellent
6:1
203
2000
Excellent
6:1
203
3000
Good
6:1
203
3200
Good
6:1
203
3600
Uneven
8:1
203
2000
Excellent
8:1
203
2800
Good
8:1
203
3200
Uneven at start
8:1
103
3200
Good
8:1
103
3400
Uneven
The trials demonstrated that excellent runnability and coverage could be achieved at 2500 feet/minute, a speed substantially higher than the 900-1500 feet/minute common on off-machines producing coated ink jet papers. Optimization of the coating formulation of the present invention can increase the speeds at which the present zeolites can be used to coat ink jet paper.
In evaluating the present zeolite for use in coating ink jet paper it was important to take into account the effects of calendering 17 . Commercial coated ink jet papers are usually soft nip calendered to improve image density. In order to determine the effects of calendering, test prints were made with both uncalendered and laboratory calendered CLC coated papers. As expected, calendering improved print density. The samples were printed on three different commercial ink jet printers, Canon BJ500™, HP 932C™, and Epson 800™. Two commercial premium coated ink jet papers, Weyerhaeuser Satin Ink Jet™ and International Paper Great White™ Premium Matte Ink Jet Paper, and a plain paper specially surface sized for ink jet printing were printed as bench marks. The ink densities of the printed sample were compared using an X-Rite densitometer. The ink densities of the present zeolite coated papers were found to be statistically equal to or better than the premium commercial papers for all three printers. The best quality was achieved at 2:1 pigment to binder ratio. The results of this experiment are contained in Table 5, which presented the data for the laboratory-calendered samples. Laboratory calendering increased densities of all four colors on all three printers. No attempt was made to optimize the zeolite formulations in contrast to the commercial silica coated papers that are made with optimized formulations and manufacturing procedures. In commercial practice, each paper manufacturer will optimize its formulation to match the characteristics of the base paper to be coated and the coating equipment to be used.
17 Calendering is the process of compacting and smoothing paper during manufacture by passing it through a stack of polished metal rollers called calenders.
TABLE 5
Printability Tests of CLC Coated with Zeolite
CLC SAMPLES (Flexible Blade Coated)
Airvol 203 2:1 Pigment to Binder (35% solids)
Average Reflective Densities-X-Rite Densitometer
Cyan
Magenta
Yellow
Black
Printed on HP932C (600 × 600 dpi)
CLC Coated Samples
Coat Weight-gsm
3.6
1.334
1.398
0.962
1.536
4.6
1.312
1.412
0.974
1.522
5.4
1.316
1.338
0.964
1.498
8.8
1.302
1.404
0.958
1.566
13.9
1.354
1.438
0.980
1.530
Commercial Paper Control Samples
Great White
1.110
1.162
0.896
1.494
Weyerhaeuser
1.408
1.478
1.026
1.612
Plain Multi-Purpose
1.100
1.150
0.900
1.500
Printed on EPSON 800 series (720 × 1440 dpi)
CLC Coated Samples
Coat Weight-gsm
3.6
0.988
1.186
0.890
1.514
4.6
1.054
1.190
0.906
1.530
5.4
1.016
1.190
0.898
1.548
8.8
1.042
1.184
0.892
1.498
13.9
1.048
1.200
0.898
1.522
Commercial Paper Control Samples
Great White
1.030
1.250
0.960
1.636
Weyerhaeuser
0.888
1.020
0.860
1.280
Plain Multi-Purpose
0.946
1.036
0.836
1.306
Printed on CANON BJC 5000 (720 × 1440 dpi)
CLC Coated Samples
Coat Weight-gsm
3.6
1.524
1.568
0.934
1.420
4.6
1.532
1.422
0.898
1.410
5.4
1.474
1.510
0.908
1.396
8.8
1.548
1.602
0.932
1.500
13.9
1.468
1.608
0.946
1.530
Commercial Paper Control Samples
Great White
1.438
1.486
0.972
1.560
Weyerhaeuser
1.146
1.308
0.866
1.748
Plain Multi-Purpose
0.978
1.052
0.802
1.448
In addition to its high quality performance, the zeolite pigment provides other significant advantages compared to silica pigments. The zeolite pigment produces higher slurry solids with 50% for zeolite compared to 30% maximum for silica and 42-45% for specialty hybrid kaolin pigments which is a significant advantage in coating preparation. In addition, the zeolite pigment has higher coating solids with 36-40% for zeolite pigment compared to <20% for silica and 30-33% for specialty hybrid kaolin pigments which means significantly lower cost for drying and higher coating line operating speeds. Coating at higher solids not only saves energy and increases production rate, but also results in a higher quality coated surface. The zeolite pigment also has a low binder demand. Coatings prepared at pigment-to-binder ratios as high as 14:1 did not show signs of cracking or flaking. With silica pigment, it is essential to use polyvinyl alcohol, which is the strongest available binder. An inexpensive starch cobinder can be used with the zeolite pigment of the present invention. This capability can be a key to making a higher fidelity mid-priced coated ink jet paper. The zeolite pigment additional has excellent rheology for use in various types of coaters including on-machine metering size presses. Silica coatings must be applied on low speed (1000 to 1500 feet/minute) off machine coaters, which significantly increases costs. Coating with the zeolite pigment of the present invention on-machine at speeds in the 3000-4000 feet/minute range combined with elimination of the extra costs associated with off machine coating can facilitate serving a larger market.
The best ink jet densities were obtained using polyvinyl alcohol binder at 2:1 pigment to binder ratio. Density was reduced at higher pigment-to-binder ratios. This confirms the function of the superior pigment void volume of the zeolite pigment. The implication of this is that the zeolite pigment of the present invention can be effective in several applications including improvement of flexo ink vehicle receptivity to prevent smudging in direct post print of corrugated containers and use of the pigment as filler in newsprint and uncoated ground wood papers to eliminate print-through. Calcined kaolin, silicas, and silicates currently used in this second application are not cost effective.
Changes in retailing are driving the need for high quality multi-color printing on corrugated containers. In-line printing via flexography 18 without drying is the current preferred process. If the ink vehicle is not rapidly absorbed the surface smudges. Use of coating pigments with good void volume can prevent smudging. The best performing current pigments are calcined kaolin and calcium carbonate; however, both are abrasive. Abrasive coating pigments make the surface prone to metal marking producing gray streaks on the printed image. Use of the zeolite pigment of the present invention which is nonabrasive as 10 to 15% of the total coating pigment should provide the needed ink vehicle absorption without metal marking.
18 Flexography is a method of printing on a web press using rubber plates with raised images.
Coating drawdowns on linerboard were performed to determine the impact of the zeolite pigment on dynamic contact angle wetability, which is a good predictor of performance in direct print flexo on corrugated. Linerboard was precoated with 10 gsm of precoat formulation. The precoated samples were then top coated with 15 gsm of a standard formulation and also a formulation substituting 10 parts ZOBrite pigment.
The coating formulations used were:
Dry Parts
Component
Precoating-Applied at 10 gsm
100
Exsilon ™ chemically structured kaolin
15
Acetate latex-Rohm & Haas 3103
3
Pro-Cote ® 4200 cold water dispersible soy protein
0.9
AZC crosslinker-HTI AZ-Cote ® 5800 M
0.1
Polyacrylate dispersant-Dispex ® N-40
0.28
Ammonia-as required for pH 8.5
Top Coat Without Zeolite-Applied at 15 gsm
40
No. 1 high brightness coating clay-Ultra-White 90
40
Fine ground calcium carbonate-Hydrocarb ® 90
20
Titanium dioxide-rutile-TiPure ® RPS Vantage
14
Acetate latex-Rohm & Haas 3103
4
Pro-Cote 4200 cold water dispersible soy protein
0.7
Calcium stearate lubricant-Nopcote ® C-104-HS
1.6
AZC crosslinker-HTI AZ-Cote ® 5800 M
0.1
Polyacrylate dispersant-Dispex ® N-40
0.42
Ammonia-as required for pH 8.5
Top Coat With Zeolite-Applied at 15 gsm
10
Zeolite pigment
35
No. 1 high brightness coating clay-Ultra-White 90
35
Fine ground calcium carbonate-Hydrocarb ® 90
20
Titanium dioxide-rutile-TiPure ® RPS Vantage
14
Acetate latex-Rohm & Haas 3103
4
Pro-Cote 4200 cold water dispersible soy protein
0.7
Calcium stearate lubricant-Nopcote ® C-104-HS
1.6
AZC crosslinker-HTI AZ-Cote ® 5800 M
0.1
Polyacrylate dispersant-Dispex ® N-40
0.42
Ammonia-as required for pH 8.5
The dynamic contact angle of the coated samples was measured and the results shown in Table 6 and FIG. 1 . It was found that substitution of 10 parts zeolite in the top coat formulation provided a significant improvement in dynamic contact angle wetability. This shows the zeolite provides the capability to capture flexo ink in direct print (without drying) on a flexo-folder-gluer or case-making machine. The top coat coated with the zeolite composition was evaluated for metal marking by rubbing the surface with a nickel coin. No metal marking was observed.
TABLE 6
Dynamic Contact Angle Measurements of Coated Linerboard
Time
No
Time
10 Parts
Seconds
Zeolite
Seconds
Zeolite
0.0
63.42
0.0
51.91
22.5
62.52
6.3
51.53
45.0
60.69
54.5
51.07
57.0
59.27
67.1
49.85
64.5
58.98
79.8
50.51
Further trials were run on the CLC to determine the effect of substitution of the present zeolite for No. 1 high brightness clay in a standardized paperboard topcoat formulation:
Standardized Topcoat Formulation
Dry Parts
Component
40
No. 1 high brightness coating clay-Ultra-White 90 ®
40
Fine ground calcium carbonate-Hydrocarb ® 90
20
Titanium dioxide-rutile-TiPure ® RPS Vantage
14
Acetate latex-Rohm & Haas 3103
4
Pro-Cote 4200 cold water dispersible soy protein
0.7
Calcium stearate lubricant-Nopcote ® C-104-HS
1.6
AZC crosslinker-HTI AZ-Cote ® 5800 M
0.1
Polyacrylate dispersant-Dispex ® N-40
0.42
Ammonia-as required for pH 8.5
The control topcoat was made up at 55% solids and pH 8.5. Brookfield viscosity was 600 cPs using a No. 6 spindle at 100 rpm. Experimental coatings were made by substituting 5, 10, 15 and 20 parts zeolite pigment for No. 1 coating clay. These coatings were also prepared at 55% solids and pH 8.5. Each of the coatings was evaluated on a Hercules high shear rheometer using Bob E, 6600 rpm and spring set 200. Rheograms showed all coatings to be shear stable. Torque at 6600 maximum rpm for each of the coatings was:
Parts Zeolite
Torque-kilodyne-cm
0
1750
5
1800
10
2128
15
2053
20
2507
The topcoats were applied to precoated recycled paperboard using a CLC laboratory coater with a blade application and a target coat weight of 4 to 5 pounds per 1000 square feet. Three replicates were done for the control and each of the four experimental coatings for a total of 15 samples. Each sample was then calendered on a hard/soft nip calender at 600 pli for three passes before evaluation.
The coated and calendered unprinted paperboard samples were tested for dynamic contact angle. The results of the dynamic contact angle showed that the 15 parts of zeolite had the best absorption followed closely by the 5 and 10 parts of zeolite pigment. The more rapid drop of the contact angle with the specimens containing zeolite pigment shows that the zeolite pigment adds a greater absorption rate into the coated surface. Increasing the zeolite pigment fraction to 20 parts did not provide better absorption than achieved with 15 parts zeolite pigment.
The coated and calendered unprinted paperboard samples were tested for brightness with the following results:
Parts Zeolite
Brightness
0
82.1
5
83.8
10
84.1
15
80.5
20
80.5
There was a gain in brightness from the control (0 parts zeolite pigment) with 5 and 10 parts of zeolite pigment, then the brightness dropped with higher levels of zeolite pigment. This is encouraging for two reasons: (1) there is an increase in brightness with the addition of small amounts of zeolite pigment and (2) this increase in brightness could allow for more intense calendering of the formulations with 5 and 10 parts zeolite pigment to increase gloss.
The coated and calendered paperboard samples were printed on a GMS Flexo Print Proofer. Ink density was measured with an X-Rite densitometer. Ink density for all samples was in the range of 2.2-2.3; a density change of 2.0 points is considered significant. There is no apparent change in ink density with increasing amounts of zeolite pigment substitution. This is important in that the coated surface with the addition of zeolite pigment allows for increased absorptivity of the ink vehicle without absorbing the ink pigment into the sheet. These results are also an indication that inclusion of the zeolite pigment would be useful in improving water-based gravure printing quality.
Due to increasing postage and handling costs, the basis weight of newsprint and other uncoated groundwood printing papers continues to be reduced. At the same time, newspapers are doing more color process printing. The thinner sheets are unfortunately prone to print-through. Use of a porous filler pigment cannot only help to reduce print-through, but can also increase opacity. Newsprint is made at acid pH which prevents the use of calcium carbonate for this application since it provides too alkaline of an environment. Calcined clay works in preventing print-through, but it is difficult to retain and is also abrasive. The current products of choice are lower grade silicas and precipitated silicates, but the use of the products is not cost effective. The zeolite pigment of the present invention is not only nonabrasive, but also cost-effective.
Pilot paper machine trials were run comparing the use of the zeolite of the present invention to precipitated calcium carbonate (PCC) as filler. The trials showed significant advantages of the present zeolite pigment as filler. These pilot machine filler trials were run without use of retention aid polymers. It was found that the filler retention for the present zeolite was 2.5 to 4 times as high as PCC which facilitates running a cleaner wet end with improved sheet formation and uniform optical properties. The significantly higher retention achieved with the zeolite of the present invention is an indication that it can perform well as a substitute for silica in microparticulate retention systems. Silicas currently used in this application are not cost effective. The improved retention of the zeolite pigment is an indication that it would be useful as an alternative to costly silica as a deinking aid.
In addition, porosity tests showed that the present zeolite produced a more open sheet, which would facilitate the use of this pigment in specialty gas filtration papers and anti-tarnish papers. It was also found that the zeolite pigment of the present invention produced papers that had higher tensile strength and tensile energy absorption or stretch. Papers filled with the present zeolite also had a higher coefficient of friction, which decreases the likelihood of misfeed and jams in copiers and also improves performance in converting equipment and print shops. The zeolite of the present invention can also be useful as a frictionizer for coefficient of friction control in recycled linerboard.
The capability of the zeolite pigment to reduce print-through was evaluated by printing samples from the pilot paper machine trials on a proof press and visually inspecting them for evidence of print show-through. The control sample with no filler showed severe print-through. The sample filled with 100 pounds of zeolite pigment (4.59% measured ash content) showed no evidence of print-through. Samples filled with PCC at levels up to 250 pounds per ton showed little improvement over the unfilled control with regard to print-through. The superior performance of the zeolite pigment in minimizing print-through is an indication that it would be useful in production of ultra lightweight-coated publication papers.
A short pigmented size press coating trial was performed during the pilot paper machine run. The zeolite of the present invention was formulated in a 2:1 ratio with size press starch and applied via conventional pond size press. Runnability was good and the sheet was free from dusting. Samples of the pigmented size press coated paper were printed on the three ink jet printers. This preliminary trial work showed that the zeolite of the present invention can be used as pigment for size press coating.
Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limited sense. Various modifications of the disclosed embodiments, as well as alternative embodiments of the inventions will become apparent to persons skilled in the art upon the reference to the description of the invention. It is, therefore, contemplated that the appended claims will cover such modifications that fall within the scope of the invention.
|
A high performance purified natural zeolite pigment composition for use in papermaking and paper coating is disclosed. Use of the pigment facilitates manufacture of coated ink jet and digital printing papers with improved quality and economics. The novel zeolite pigment composition can also be used as a supplementary pigment to improve the properties of coated paper and paperboard for flexographic and water-based gravure printing. When used as filler, the novel zeolite pigment composition is readily retained and eliminates print-through in uncoated papers. The novel zeolite pigment is low in abrasion and provides improved coefficient of friction. The novel zeolite pigment is also useful as a microparticulate retention aid in papermaking and as an additive to improve the performance of deinking processes.
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FIELD OF THE INVENTION
The invention relates to building security devices and, more particularly, to devices for immobilizing a mail slot door of a building to prevent access to the building through the mail slot door.
BACKGROUND OF THE INVENTION
It is common for commercial buildings to have a mail slot for allowing mail to be delivered into the building. Typically, such mail slots are located in the front door of the building and are covered by a mail slot door. The mail slot door rotates on a hinge and can be opened to allow mail to be inserted through the mail slot.
While such mail slot arrangements are often necessary to allow mail to be received by the building occupant, they may also allow unwanted or unsolicited items to be delivered into the building, such as trash or unwanted advertising materials. In addition to requiring cleanup, these materials may accumulate on the inside of the building and be seen by passersby through store windows or glass doors. The accumulation can be unsightly and can reflect poorly on the building occupant.
In some cases, it may be possible to reach through the mail slot to the interior of the building to reach a panic bar or to unlock the door. In order to prevent unwanted access to the building in such cases, it is necessary to prevent the mail slot door from being opened.
Thus, a need exists for a device that can be installed to prevent the unwanted opening of a mail slot door and yet be easily removed when desired to allow mail to be delivered into the building.
SUMMARY OF THE INVENTION
The mail slot door immobilizer of the present invention is a removable device that prevents the unwanted opening of a mail slot door located within a main door. The mail slot door immobilizer includes an interior portion located on an interior side of the mail slot door and overlapping the mail slot door and the main door, and an exterior portion located on an exterior side of the mail slot door and overlapping the mail slot door and the main door. A fastener removably fastens the interior portion to the exterior portion to clamp the mail slot door and the main door between the interior and exterior portions and to prevent movement of the mail slot door with respect to the main door.
An important aspect of the invention is that the mail slot door immobilizer is tamper resistant. In a preferred embodiment of the mail slot door immobilizer, the fastener extends through the mail slot door from the interior portion to the exterior portion. The exterior portion is provided with an opening which extends only partially through the exterior portion. The opening has a retaining surface which cooperates with a retaining surface of the fastener to retain the fastener within the opening. Because the opening extends only partially through the exterior portion, the fastener is not visible from the exterior side of the mail slot door, thereby discouraging tampering with the fastener.
Another aspect of the invention is the ease of installation and removal of the mail slot door immobilizer. The mail slot door immobilizer can be installed on existing mail slot doors. Once installed, the mail slot door immobilizer can easily be removed and replaced.
Another aspect of the invention is the relatively small surface area of the exterior portion of the mail slot door immobilizer. The mail slot door immobilizer is intended to be used primarily in commercial buildings. It is important to owners and occupants of such buildings that the overall appearance of the building or storefront not be degraded. The relatively small surface area of the exterior portion minimizes the impact of the mail slot door immobilizer on the appearance of the main door. It also facilitates the manufacture of the mail slot door immobilizer at low cost.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a mail slot door immobilizer in accordance with the present invention mounted on a mail slot door of a main door.
FIG. 2 is a perspective view of the mail slot door immobilizer of FIG. 1 .
FIG. 3 is a horizontal cross-sectional view of the mail slot door immobilizer taken along the line 3 — 3 in FIG. 1 .
FIG. 4 is a front elevational view of the mail slot door immobilizer of FIG. 1 .
FIG. 5 is a rear elevational view of the mail slot door immobilizer of FIG. 1 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A mail slot door immobilizer in accordance with the present invention is illustrated in FIG. 1 . The mail slot door immobilizer 10 is shown mounted on a mail slot door 12 . The mail slot door 12 is located within a main door 14 having a glass interior 16 and an aluminum frame 18 .
The arrangement of the mail slot door 12 and main door 14 shown in FIG. 1 is typical in commercial buildings. The mail slot door 12 rotates on a hinge 20 located adjacent the frame 18 of the main door 14 . A mail slot door frame 22 surrounds the perimeter of the mail slot door 12 and is secured to the glass interior 16 of the main door 14 . The mail slot door 12 is opened by rotating it about the hinge 20 with respect to the mail slot door frame 22 and main door 14 .
Referring to FIG. 2, the mail slot door immobilizer 10 includes an interior portion 24 and an exterior portion 26 . The interior and exterior portions 24 , 26 are preferably fabricated from aluminum to blend with the appearance of a standard aluminum and glass door, but may be fabricated from any material of sufficient strength to resist bending or breaking by screwdrivers or similar items.
Each of the interior and exterior portions 24 , 26 has a recessed area 28 defined by a base surface 30 and opposing wall surfaces 32 , 33 . The interior portion 24 is positioned on the interior side of the mail slot door 12 so that it overlaps both the mail slot door 12 and the glass interior 16 of the main door 14 , as shown in FIGS. 1 and 3. The mail slot door frame 22 fits within the recessed area 28 of the interior portion 24 .
Referring to FIG. 3, the interior portion 24 is provided with openings 34 extending therethrough for receiving threaded fasteners 36 . The threaded fasteners 36 may be of any suitable type, such as standard, Phillips head, or Allen-type machine screws.
To install the mail slot door immobilizer 10 , holes 40 are drilled in the mail slot door 12 in register with the openings 34 in the interior portion 24 . Preferably, the holes 40 have a diameter only slightly greater than the diameter of the fasteners 36 . The interior portion 24 may be used as a template to mark the proper locations for the holes 40 . The interior portion 24 is then removed and the holes 40 are drilled through the mail slot door 12 at the marked locations.
Referring still to FIG. 3, the exterior portion 26 is provided with threaded openings 38 which extend only partially through the exterior portion 26 . The exterior portion 26 is positioned on the exterior side of the mail slot door 12 so that the threaded openings 38 are in register with the holes 40 in the mail slot door 12 and the openings 34 in the interior portion 24 . The fasteners 36 are inserted from the interior side through the openings 34 in the interior portion 24 and the holes 40 in the mail slot door 12 . The fasteners 36 extend into the threaded openings 38 in the exterior portion 26 and engage the threads of the threaded openings 28 to removably fasten the interior portion 24 to the exterior portion 26 .
The mail slot door immobilizer 10 prevents the mail slot door 12 from rotating with respect to the main door 14 by clamping the mail slot door 12 and main door 14 between the interior and exterior portions 24 , 26 . The mail slot door 12 is not allowed to rotate about the hinge 20 toward the interior because the base surface 30 of the exterior portion 26 abuts the mail slot door frame 22 . Likewise, the mail slot door 12 is prevented from rotating toward the exterior because the base surface 30 of the interior portion 24 abuts the mail slot door frame 22 .
An important aspect of the invention is that the mail slot door immobilizer 10 is tamper resistant. Because the threaded openings 38 extend only partially through the exterior portion 26 , the fasteners 36 are not visible from the exterior side. As a result, tampering with the fasteners 36 is discouraged. Because the locations of the fasteners 36 are not evident from the exterior side, disabling of the mail slot door immobilizer 10 by drilling out the fasteners 36 is made more difficult.
The mail slot door immobilizer 10 is also resistant to tampering by prying of the exterior portion 26 . Preferably, the recessed area 28 is sized so that the base surface 30 of the exterior portion 26 abuts the mail slot door frame 22 when the fasteners 36 are fully tightened. As a result, it would be difficult to insert a screwdriver or other tool between the base surface 30 and mail slot door frame 22 in order to pry the exterior portion 26 from the mail slot door 12 . However, even if it is possible to insert a screwdriver between the base surface 30 and the mail slot door frame 22 , it would be difficult to pry the exterior portion 26 from the top or bottom because the fasteners 36 are engaged near the top and bottom of the exterior portion 26 . Thus, the lever arm created between the top or bottom of the exterior portion 26 and associated fastener 36 would be fairly insignificant.
The exterior portion 26 is relatively narrow horizontally. Desirably, the width of the exterior portion 26 is between 0.50 and 5.00 inches. More desirably, the width of the exterior portion 26 is between 0.75 and 3.00 inches. The width of the exterior portion is preferably 1.25 inches. Because the exterior portion 26 is relatively narrow, the lever arm created between either side of the exterior portion 26 and the fasteners 36 would likewise be fairly insignificant, thus making it difficult to pry the exterior portion 26 from either side.
The interior and exterior portions 24 , 26 are relatively thick in a direction perpendicular to the plane of the mail slot door 12 . Desirably, the thickness of each of the interior and exterior portions 24 , 26 is between 0.25 and 1.00 inches. More desirably, the thickness of each of the interior and exterior portions 24 , 26 is between 0.40 and 0.75 inches. The thickness of each of the interior and exterior portions 24 , 26 is preferably 0.48 inches. Because of the thickness of each of the interior and exterior portions 24 , 26 , and the resulting strength of the mail slot door immobilizer 10 , any attempt to pry the exterior portion 26 from the mail slot door 12 would likely cause the glass interior 16 of the main door 14 to break.
The mail slot door immobilizer 10 also prevents opening of the mail slot door 12 by bending or bowing it. The holes 40 in the mail slot door 12 and fasteners 36 extending therethrough provide a secure attachment of the mail slot door 12 to the mail slot door immobilizer 10 . When the mail slot door 12 is bowed inwardly, the base surface 30 and wall surface 33 of the exterior portion 26 abut the mail slot door frame 22 , thereby preventing further bowing of the mail slot door 12 . Likewise, when the mail slot door 12 is bowed outwardly, the base surface 30 and wall surface 33 of the interior portion 24 abut the mail slot door frame 22 .
In addition, the interior and exterior portions 24 , 26 are of sufficient height relative to the mail slot door 12 to prevent bowing of the mail slot door 12 at the top and bottom thereof. Desirably, the height of each of the interior and exterior portions 24 , 26 is between 1.00 and 6.00 inches. More desirably, the height of each of the interior and exterior portions 24 , 26 is between 2.00 and 4.00 inches. The height of each of the interior and exterior portions 24 , 26 is preferably 3.00 inches.
Another aspect of the invention is the ease of installation and removal of the mail slot door immobilizer 10 . The mail slot door immobilizer 10 fits most existing mail slot door arrangements of the type shown in FIG. 1 . Installation of the mail slot door immobilizer 10 requires only the drilling of two small holes 40 in the mail slot door 12 . Once installed, the mail slot door immobilizer 10 can be removed and replaced simply by inserting or removing the fasteners 36 with a standard screwdriver or Allen wrench.
A further aspect of the invention is the relatively small surface area of the exterior portion 26 of the mail slot door immobilizer 10 . The mail slot door immobilizer 10 is intended to be used primarily in commercial buildings. It is important to owners and occupants of such buildings that the overall appearance of the building or storefront not be degraded. Desirably, the area of the surface of the exterior portion 26 which is parallel to the mail slot door 12 and main door 14 and which faces away from the mail slot door 12 and main door 14 is between 0.50 and 30.00 square inches. More desirably, the area of the surface of the exterior portion 26 which is parallel to the mail slot door 12 and main door 14 and which faces away from the mail slot door 12 and main door 14 is between 1.50 and 12.00 square inches. Preferably, this surface area is 3.75 square inches. Because of the relatively small surface area of the mail slot door immobilizer 10 , its impact on the appearance of the main door 14 is minimized, and the low-cost manufacture of the mail slot door immobilizer 10 is facilitated.
It will be apparent to those skilled in the art that some modification of the disclosed embodiment may be possible without departing from the spirit of the invention. For example, other means may be used to fasten the interior portion 24 to the exterior portion 26 . Instead of the threaded fasteners 36 , for example, a key lock in the interior portion 24 may be used to selectively engage a surface of the exterior portion 26 and thereby removably fasten the interior portion 24 to the exterior portion 26 . Therefore, the foregoing description is considered to be exemplary, and the true scope of the invention is that defined in the following claims.
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A mail slot door immobilizer for immobilizing a mail slot door within a main door, including an interior portion located on an interior side of the mail slot door and overlapping the mail slot door and the main door, and an exterior portion located on an exterior side of the mail slot door and overlapping the mail slot door and the main door. A fastener removably fastens the interior portion to the exterior portion to clamp the mail slot door and the main door between the interior and exterior portions and to prevent movement of the mail slot door with respect to the main door.
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TECHNICAL FIELD OF THE INVENTION
[0001] The present invention relates to tuberculosis diagnosis; more particularly, relates to using a chip array construction of specific tubercle bacillus (TB) genes and drug-resistance genes for detecting tubercle bacillus and drug resistance.
DESCRIPTION OF THE RELATED ARTS
[0002] TB is an old contagious disease. Although it has been long on developing methods for preventing, controlling and curing this disease, TB is still a key issue in the world, which kills greatest number of people among all contagious diseases.
[0003] A characteristic of TB is that there may be no sign appeared after a person is infected and only 10% of the patients have morbidity. Most of the patients have the thalli lived in their bodies for a long time before the morbidity appears. Thus, the cause that turns a patient of latent TB into one of active TB may be exogenous reinfection or endogenous reactivation. Hence, for diagnosing TB clinically, clinical expression shown on the patients, changes shown on X-ray films and laboratorial experiments are all required for confirmation.
[0004] Regarding laboratorial examination, technologies relating to histopathology, staining of acid-fast bacterium and TB culturing are used. However, they all have their limits. Take staining of acid-fast bacterium as an example. At least 5000 to 10000 bacteria have to be contained in one milli-liter of a specimen. Besides, there exists a high possibility of fake positive for this method. That is because some other bacteria may show positive results too. Regarding TB culturing, although it is the most sensitive diagnosing method, it takes 4 to 8 weeks to obtain the result and is not suitable for clinical use.
[0005] As following development of biological technologies, clinical diagnosis of TB has evolutional progress on molecular diagnostic technologies, like polymerase chain reaction (PCR), PCR-Restriction Fragment Length Polymorphism (PCR-RFLP), etc. In the early years, PCR are directly used for detecting molecular marks of TB in patients' specimens, like deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) of heat shock proteins 65 (hsp65) and inserted section 6110 (IS6110). In addition, with coordination of restriction fragment length polymorphism (RFLP), the nucleic-acid molecular typing of the detected thallus is identified. However, expression of specific DNA or messenger ribonucleic acid (mRNA) in a patient's specimen is still not satisfactory clinically.
[0006] Through decoding the TB genes, it is found that genomic deletion is existed between TB and mycobacterium bovis BCG, where lost sections are called regions-of-difference (RD). The causes for these RDs may be errors on duplicating DNAs of the genes or on inserting sections, including deletion, insertion, inversion, replication, etc.
[0007] The RD sections have many important genes and pathogenic factors. These sections may differ between pathogens of TB genes. Hence, the RD sections can be used for identifying the TB genes, which identifies specific genes with high sensitivity.
[0008] In 2009, 14 specific target genes were selected as testing targets for constructing a TB gene diagnosis chip. Through using a platform for detecting tiny amount of nucleic acid, multiple gene targets are detected simultaneously, where sensitivity reaches a level for detection with only 5 cells in one milli-liter of blood. Thus, a TB gene detection chip for sputum specimen is constructed.
[0009] This chip can detect 85% of TB complex (TBC), where PCR-RFLP is 62.5%. In an experiment, 52 specimens are picked out by the chip from 56 positive-cultured and positive-dyed sputum specimens, where only 39 are picked out through PCR-RFLP. In another experiment, 16 specimens are picked out by the chip from 24 positive-cultured and negative-dyed sputum specimens, where only 11 are picked out through PCR-RFLP.
[0010] Accordingly, gene chip detection is easily operated without much human labor and time. Moreover, sensitivity of the gene chip detection is far higher than PCR-RFLP.
[0011] In the market, some TB detection sets include Spoligotyping Method (Holland), TB Ag Rapid Test (Taiwan), Amplified MTDR (USA), DR. MTBC Screen Kit (Taiwan) and GenoType MTBDRplus (German). Therein, Spoligotyping Method detects TB oligonucleotide spectrum at first and, then, finds its typing from a database. But, the resolving power is low and drug resistance is not detected. TB Ag Rapid Test uses specific antigen to detect TB directly. But, its cost is high; TB colony has to be cultured; its procedure is complex; it takes time; and, not to mention, drug resistance is not detected. DR. MTBC Screen Kit magnifies specific gene sections through PCR and, then, the chip is processed through hybridization. Although drug-resistance genes against Rifampicin can be found, 100-thousand TB bacteria in one milli-liter of sputum are required for valid detection with a 65% sensitivity only. GenoType MTBDRplus magnifies TB drug-resistance genes through PCR and, then, hybridization is processed with probes. Although drug-resistance genes in TB against Ofloxacin, Streptomycin and Ethambutol can be found, its cost is high; its technology is complex; it takes time for detection; and it only tests efficacy but not TB itself.
[0012] Furthermore, a prior art of detection chip directly detected active TB in a sputum specimen. Yet, it detects Tb only and do not analyzes efficacy on gene cluster. Hence, the prior arts do not fulfill all users' requests on actual use.
SUMMARY OF THE INVENTION
[0013] The main purpose of the present invention is to use a construction of specific TB genes and drug-resistance genes for detecting TB and testing drug resistance simultaneously.
[0014] To achieve the above purpose, the present invention is a method of fast tuberculosis diagnosis and efficacy test, comprising steps of: (a) obtaining a sputum specimen and extracting messenger ribonucleic acids (mRNAs) in the sputum specimen to synthesize a required amount of complementary deoxyribonucleic acids (cDNAs) through reverse transcription; (b) labeling the cDNAs with Biotin to obtain a plurality of bioprobes; (c) synthesizing TB genes and drug-resistance genes in vitro into a specific gene cluster of TB and a drug-resistance gene cluster and obtaining a chip array construction through crosslinking by dotting the specific gene cluster of TB, the drug-resistance gene cluster, positive controls, negative controls and blank controls into array on a nylon membrane, where the specific gene cluster of TB is specified through a specific oligonucleotide design; and where the chip array construction is formed into a plurality of gene-testing points on the nylon membrane; (d) hybridizing the gene-testing points of the chip array construction with biomolecules of the bioprobes and washing out un-hybridized bioprobes; and (e) blocking the bioprobes obtained after hybridization of the chip array construction to form crosslinks with Streptavidin-HRP accompanied with a washing process afterwards and, then, adding a coloring agent of diaminobenzidine (DAB) to process color development for analyzing and interpreting an image thus obtained. Accordingly, a novel method of fast tuberculosis diagnosis and efficacy test is obtained.
BRIEF DESCRIPTIONS OF THE DRAWINGS
[0015] The present invention will be better understood from the following detailed description of the preferred embodiment according to the present invention, taken in conjunction with the accompanying drawings, in which
[0016] FIG. 1 is the flow view showing the preferred embodiment according to the present invention;
[0017] FIG. 2 is the view showing the testing areas;
[0018] FIG. 3 is the view showing the gene arrangements;
[0019] FIG. 4 is the view showing the interpretation of the bacillus tuberculosis testing; and
[0020] FIG. 5 is the view showing the interpretation of the drug resistance testing.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0021] The following description of the preferred embodiment is provided to understand the features and the structures of the present invention.
[0022] Please refer to FIG. 1 , which is a flow view showing a preferred embodiment according to the present invention. As shown in the figure, the present invention is a method of fast tuberculosis diagnosis and efficacy test, comprising the following steps:
[0023] (a) DNA extraction 11 : A sputum specimen of a patient is collected and messenger ribonucleic acids (mRNAs) in the sputum specimen is extracted for synthesizing a required amount of complementary deoxyribonucleic acids (cDNAs) through reverse transcription.
[0024] (b) Multiple linear amplification and labeling 12 : The cDNAs are labeled with Biotin to form a plurality of bioprobes.
[0025] (c) Fabrication of chip array construction 13 : Tubercle bacillus (TB) genes along with drug-resistance genes are synthesized in vitro into a specific gene cluster of TB along with a drug-resistance gene cluster, where the specific gene cluster of TB is specified through a specific oligonucleotide design. Then, a chip array construction is formed through crosslinking by dotting the specific gene cluster of TB, the drug-resistance gene cluster, positive controls, negative controls and blank controls into array on a nylon membrane. Therein, the specific gene cluster of TB comprises 13 specific TB genes; the drug-resistance gene cluster comprises 6 drug-resistance genes; and the chip array construction is formed into a plurality of gene-testing points on the nylon membrane.
[0026] (d) Hybridization 14 : The bioprobes are hybridized with the chip array construction, where the gene-testing points of the chip array construction are hybridized with biomolecules of the labeled bioprobes. Then, un-hybridized bioprobes are washed out.
[0027] (e) Color development 15 : After hybridization with the chip array construction, the bioprobes are blocked to form crosslinks with Streptavidin-HRP accompanied with a washing process afterwards. Then, a coloring agent of diaminobenzidine (DAB) is added for color development to analyze and interpret an image thus obtained.
[0028] As shown in Table 1, the specific gene cluster of TB comprises specific oligonucleotide sequences selected from the specific TB genes. These 13 specific TB genes comprises hsp65, Rv0577, Rv3120, Rv2073c, Rv1970, Rv3875, Rv3347c, Rv1510, Rv0186, Rv0124, TbD1, mtp40 and mpb83, which are obtained through analysis by Primer Premier 5.0 (PREMIER Biosoft International, Palo Alto, Calif.).
[0000]
TABLE 1
Gene
No.
Name
Oligonucleotide Sequence
1
hsp65
CAT CGG TCT TCT TGG CTA CCT CTT TGA CCA GCT CG
2
Rv0577
CGT CGT AAC CCC AGC CGA ACA ACG ATG TGT AGA AC
3
Rv3120
CGG ATG CCA GAA TAG TCG GCA AAG TAC CAG AGC A
4
Rv2073c
GCC GGC TTT GGC CGA TCC GTA GAC ATA GTT G
5
Rv1970
GTC ACC GGA CTG GTT GTT GAG GTA TGC GGT G
6
Rv3875
CTT CCC CTC GTC AAG GAG GGA ATG AAT GGA CGT G
7
Rv3347c
GTG TTG TAG CTG CCC GAG TTG AAT ACC CCG AAG TT
8
Rv1510
CCA GAT AGA TGA CCG TGT AGA CGC AGG CAA CGG
9
Rv0186
GGT CCT CGG AAA GGT ACT CGA AGT TGC GGC
10
Rv0124
CGT CTG CAC GAA CTG CTG ATG AAA CGC CG
11
TbD1
TCG GCT GCT CGG TCC CTC TGA TAC TTG AGA TTC TG
12
mtp40
ATC CGC AGT GAT GCC AAC TCA GGA AAC CAC AC
13
mpb83
GAG GTC AGG GTA CTG AGC ATC GGG TTG TTG GAA G
[0029] As shown in Table 2, the drug-resistance gene cluster for testing anti-tuberculosis drugs comprises 6 oligonucleotide sequences, which comprises katG, rpoB, gyrA, embB, rpsL and rrs.
[0000]
TABLE 2
Oligonucleotide
Drug
Name
Oligonucleotide sequence (5′ to 3′)
Isoniazid
katG-W1
AAC TAG CTG TGA GAC AGT CAA TCC CGA TGC CCG
katG-W315
CGA TGC CGC TGG TGA TCG CGT CCT TA
katG-Q315
CGA TGC CGC TGG TGA TCG TGT CCT TA
Rifampicin
rpoB-W1
GAC TCG GAC TAG GAC TAG CGG CTG TTT TGC TCT
rpoB-W450
CCC TCA GGG GTT TCG ATC GGG CAC AT
rpoB-Q450
CCC TCA GGG GTT TCG ATC GAG CAC AT
rpoB-W513
TCG ACC ACC TTG CGG TAC GGC GTT TC
rpoB-Q513
TCG ACC ACC TTG CGG TAC GGA GTT TC
rpoB-W522
GTA CAC GAT CTC GTC GCT AAC CAC GCC GT
rpoB-Q522
GTA CAC GAT CTC GTC GCT AAC TAC GCC GT
rpoB-W526
GTC GGC GGT CAG GTA CAC GAT CTC GT
rpoB-Q526
GTC GGC GGT CAG GTA CAT GAT CTC GT
rpoB-W529
TCC TCC TCG TCG GCG CTC AGG TAC A
rpoB-Q529
TCC TCC TCG TCG GAG CTC AGG TAC A
rpoB-W531
CCA CCA CGT GGC GGT CCT C
rpoB-Q531
CCA CTA CGT GGC GGT CCT C
Ofloxacin
gyrA-W1
CGG GAA TCC TCT TCT ACC TCA ACA ACT CCG CGC
gyrA-W80
CCC ATG GTC TCG GCA ACC GAC CG
gyrA-Q80
CCC ATG GTC TCG GCA ACT GAC CG
gyrA-W88-91
CGT AGA TCG ACG CGT CGC CGT GC
gyrA-Q88-91
CGT ATA TCG ACG CGT CGC CGT GC
gyrA-W94
GCC ATG CGC ACC AGG CTG TCG TAG AT
gyrA-Q94
GCC ATG CTC ACC AGG CTG TCG TAG AT
Ethambutol
embB-W1
GTG TCC AGC TTC TTA GCC GAG TAG TCC GGT GT
embB-W306
CGG GCC ATG CCC AGG ATG TAG CC
embB-Q306
CGG GCC ATG CCC AGG ATA TAG CC
embB-W319
GGG CTG CCG AAC CAG CGG AAA TAG TTG G
embB-Q319
GGG CTG TCG AAC CAG CGG AAA TAG TTG G
embB-W406
CGA GCG CGA TGA TGC CCT CCG
embB-Q406
CGA GCT CGA TGA TGC CCT CCG
Streptomycin
rpsL-W1
GCG GTC TTG ACC TTA CTG ATC TTG TCC CGA
rpsL-W43
GAA GCG CCG AGT TCG GCT TCT TCG GAG
rpsL-Q43
GAA GCG TCG AGT TCG GCT TCT TCG GAG
rpsL-W88
GCA CAC CAG GCA GGT CCT TCA CCC
rpsL-Q88
GCA CAC TAG GCA GGT CCT TCA CCC
Streptomycin
rrs-W1
CGT AGG AGT CTG GGC CGT ATC TCA GTC CCA
rrs-W513
CCT ACG TAT TAC CGC GGC TGC TGG CA
rrs-Q513
CCT ACT TAT TAC CGC GGC TGC TGG CA
rrs-W514
GCA CCC TAC GTA TTA CCG CGG CTG CT
rrs-Q514
GCA CTC TAC GTA TTA CCG CGG CTG CT
rrs-W1401
TGA CGT GAC GGG CGG TGT GTA CAA GG
rrs-Q1401
TGA CGT GAC GGG CGG TAT GTA CAA GG
rrs-W1484
GAC TTC GTC CCA ATC GCC GAT CCC ACC TTC
rrs-Q1484
GAC TTC GTC CCA ATC GCC GAT CCT ACC TTC
Positive control
rrl
GTG TTA CCA CTG ACT GGT ACG GCT ACC TTC CTG
[0030] Please refer to FIG. 2 and FIG. 3 , which are views showing testing areas and gene arrangements. As shown in the figures, a chip array construction 20 comprises a testing area of bacillus tuberculosis 21 and a testing area of drug resistance 22 . In FIG. 2 , P is a positive control 23 , N is a negative control 24 and B is a blank control 25 .
[0031] The testing area of bacillus tuberculosis 21 comprises a plurality of gene-testing points 2 a for separately conjugating a specific gene cluster of TB with specific bioprobes to be reacted with specific biomolecules of the specific bioprobes for color development. This specific gene cluster of TB comprises 13 specific TB genes, which are hsp65, Rv0577, Rv3120, Rv2073c, Rv1970, Rv3875, Rv3347c, Rv1510, Rv0186, Rv0124, TbD1, mtp40 and mpb83.
[0032] The testing area of drug resistance 22 has a plurality of gene-testing points conjugated with a drug-resistance gene cluster to be reacted with anti-tuberculosis drugs of Isoniazid, Rifampicin, Ofloxacin, Ethambutol and Streptomycin for color development. The conjugated drug-resistance gene cluster comprises 6 drug-resistance genes, which are katG, rpoB, gyrA, embB, rpsL and rrs.
[0033] The above gene-testing points 2 a. 2 b are arranged into array.
[0034] Please refer to FIG. 4 , which is a view showing an interpretation of the bacillus tuberculosis testing. As shown in the figure, 13 specific TB genes and 6 drug-resistance genes are arranged in array on a nylon membrane to form a chip array construction. Therein, a testing area of bacillus tuberculosis 21 is processed through color development. If a color is developed, a specific gene is detected by expression for identification. In the figure, a result of color development for the chip array construction are as follows: hsp65(+), Rv0577(+), Rv31 20(−), Rv2073c(−), TbD1 (+), Rv1970(−), Rv3875(+), Rv3347c(+), Rv1510(−), Rv0186(+), Rv0124(+), mtp40(+) and mpb83(+). For interpretation, the sign (+) means positive reaction. More detailed comparison is shown in the following Table 3.
[0000]
TABLE 3
hsp65
Rv0577
Rv3120
Rv2073c
TbD1
Rv1970
Rv3875
Rv3347c
Rv1510
Rv0186
Rv0124
mtp40
mpb83
Organisms other than
−
−
Mycobacterium
NTM*
+
−
M. canettii
+
+
−
+
+
+
+
+
+
+
+
+
+
M. tuberculosis
+
+
+
+
−
+
+
+
+
+
+
+
+
M. africamun (lb)
+
+
+
−
+
+
+
+
+
+
+
+
+
Oryx bacillus
+
+
+
−
+
−
+
+
+
+
+
+
+
M. africamun (lib)
+
+
+
−
+/−
−
+
+
+
−
−
+
+
Dassiebacillun
+
+
+
−
+
−
−
+
+
+
+
+
+
M. microti
+
+
+
−
+
−
−
−
+
+
+
+
+
M. caprie
+
+
−
−
+
−
+
+
+
+
+
+
+
M. bovis
+
+
−
−
+
−
+
+
−
+
+
+
+
M. bovis BCG
+
+
−
−
+
−
−
+
−
+
+
+
+
*NTM: Nontuberculous Mycobacterium
[0035] Please refer to FIG. 5 , which is a view showing an interpretation of the drug resistance testing. As shown in the figure, 13 specific TB genes and 6 drug-resistance genes are arranged to form a chip array construction on a nylon membrane. Therein, a testing area of drug resistance 22 is used for testing Ethambutol. EmbB-W1 is set as a positive control to develop color for embB; embB-W306, embB-W319 and embB-W406 are wild-type probes for embB codon 306, 319 and 406; and, embB-Q306, embB-Q319 and embB-Q406 are inner controls for embB codon 306, 319 and 406 in easily-mutating positions., when the gene is mutated and is not connected to the wild-type probe, the color is not developed and, thus, mutation of the drug-resistance gene is analyzed. A result is shown as follows: codon 306 (+), codon 319 (+) and codon 306 (+). Interpretation made for the result is that embB codon 306 is mutated, which shows this gene has drug resistance to Ethambutol.
[0036] To sum up, the present invention is a method of fast tuberculosis diagnosis and efficacy test, where specific TB genes and drug-resistance genes are used as probes to test TB and drug resistance simultaneously through analysis after hybridization; and, thus, the present invention is a fast method with low cost for detecting TB and testing drug resistance simultaneously.
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A method is provided for fast diagnosis of tubercle bacillus (TB). The method can be used for efficacy test at the same time. 13 specific TB genes and 6 drug-resistance genes are selected. Those genes are formed into a construction for diagnosing tuberculosis and testing drug resistance simultaneously.
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This application is a division of application Ser. No. 08/614,289, filed Mar. 12, 1996, now U.S. Pat. No. 5,730,630.
This invention relates generally to electronic assemblies and more specifically to the attachment of electrical connectors to circuit boards.
Electronic systems, such as computers, are generally made with printed circuit boards. Circuits on the boards route electrical signals to many electrical components on the board. When it is necessary to route electrical signals from a board to another point off that board, an electrical connector is used.
For example, electrical connectors are used to connect several printed circuit boards to a backplane. The backplane routes electrical signals from one printed circuit board to another. Connectors are also used for other purposes, such as to connect cables to a printed circuit board
The connectors can be plugged together to make a connection or unplugged to allow the printed circuit to be removed. Connectors simplify the manufacture and repair of electronic systems in comparison to the use of fixed connections, such a soldered wires.
Connectors in many types have been used and are well known. Various ways have been used to attach connectors to printed circuit boards. In each way, it is necessary that the conductors within the connector that carry the electrical signals be electrically connected to the circuit paths on the printed circuit board.
Some connectors make use of plated through holes in the printed circuit board. Each hole passes through a conductive path on the printed circuit board. The plating on the inside of the hole is conductive and makes an electrical connection with the conductive path. The conductors within the connector have tails which extend from the connector. These tails extend from the connector and are inserted into the holes.
In some connectors, the hole is filled with solder after the tail is inserted. The solder holds the connector in lace and ensures a good electrical connection. In other instances, the tails are made with springy features. These features compress as the tail is inserted into the hole, but they press against the sides of the holes. The spring force against the sides of the holes makes a good electrical and mechanical connection. Such connectors are called "press-fit" connectors.
There are some difficulties in attaching connectors to printed circuit boards using plated through holes. First, drilling and plating the holes in the printed circuit board requires steps in the manufacturing process. If no other components are attached to the printed circuit board with plated through holes, making the plated through holes just to attach a connector is undesirable. Also, there are limits on how close together the holes can be. These limits translate into limitations on the number of signals that can pass through the connector.
To address these limitations, surface mount connectors have been used. In a surface mount connector, very fine tails extend from the connector. These tails align with conductive pads on the surface of the printed circuit board and are soldered to the pads. Because the pads are part of the conductive paths on the printed circuit board, they can be simply made in the same step as those conductive traces.
The spacing between the conductive pads on the printed circuit board and also the tails extending from the connector can be very small. Pads spaced by 0.02 inches on center or smaller have been used.
To align the tails to the pads, the ends of all the tails extending from one side of the connector are held together by a tie bar. Traditionally, the tie bar is just a small strip of plastic molded over the ends of the tails. It holds the tails together and allows them to be moved as a group. In theory, the spacing between the tails is fixed by the tie bar so that when one tail is positioned above a pad, all of the tails are properly positioned above their respective pads.
In the manufacture of printed circuit boards, the step of aligning the tails to the pads is often done manually. A person looking through a microscope grasps the tie bar at its end with a pliers-like tool and pulls the tie bar until the tails are in course alignment with the pads. A tool shaed like a pointed stick is then used to adjust each lead individually, as necessary. The tails are then soldered to the contact pads. The soldering step is often automated. After soldering, the tie bar is broken off.
An alternative alignment tool is shaped as a comb. The teeth of the comb is inserted between the leads such that each tooth pushes one lead. The tool is moved side to side until the leads are in alignment. Such a tool has the draw back of obscuring the pads, making alignment difficult. It also must be removed before the soldering operation, which can sometimes be undesirable.
In some instances, the plastic tie bar does not preserve the correct spacing between all of the tails. In those instances, the human operator sometimes finds it necessary to make cuts in the tie bar so that the tails in various portions of the connector can be correctly positioned. In that case, each lead must be individually aligned.
To avoid the need for cutting the tie bar and individually positioning sections of the connector, Teradyne Connections Systems of Nashua, N.H., USA markets a surface mount connector with a metal tie bar. The connector is sold under the tradename UHD. The metal tie bar is more stable than a plastic tie bar.
However, regardless of what the tie bar is made of, it is sometimes difficult to grasp the tie bar so that it can be precisely positioned. When the connector is mounted to the printed circuit board, the tie bar is very close to the surface of the board. In addition, there are generally many other components mounted to the surface of the board in the vicinity of the connector. There is thus little room to get a tool on the tie bar in order to grasp it.
If the alignment of contact tails to contact pads on the circuit board could be simplified, both the cost and required time for manufacturing a printed circuit boards could be decreased. More accurate positioning of the connector tails could also be facilitated, thereby reducing the number of defective printed circuit boards produced.
SUMMARY OF THE INVENTION
With the foregoing background in mind, it is an object of the invention to provide a surface mount connector configured to facilitate alignment of the connector tails to contact pads on a circuit board.
It is also an object to provide a tool for use in easily positioning connector tails.
The foregoing and other objects are achieved in a surface mount connector having a tie bar joining the contact tails. The tie bar and alignment tool are designed with complementary features which interlock. The alignment tool projects above the printed circuit board, presenting a surface which can be readily grasped for easy alignment.
In a preferred embodiment, the tie bar has hook-like tabs which engage openings in the tool. The openings are formed in a thin blade section of the tool which can be positioned near the tie bar.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood by reference to the following more detailed description and accompanying drawings in which
FIG. 1 shows a connector according to the invention positioned near an alignment tool and a printed circuit board; and
FIG. 2 shows the connector of FIG. 1 with the alignment tool engaged.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 shows a surface mount connector 110. Connector 110 has numerous contact elements 112. Each contact element 112 has a tail portion 114 projecting from a rear surface of connector 110. Connector 110 is manufactured in accordance with known manufacturing techniques.
The contact tails 114 are held together at one end by tie bar 120. In a preferred embodiment, tie bar 120 is a metal tie bar. It might be soldered on to the contact tails 114 after they are formed. Alternatively, in situations where it is possible to stamp multiple contact elements 112 from the same metal blank, tie bar 120 can be formed by simply leaving a portion of the blank in the stamping operation.
Tie bar 120 includes numerous tabs 122 along its length. As will be described in greater detail below, tabs 122 facilitate positioning of contact tails 114.
Connector 110 is intended to be mounted to printed circuit board 130. Any convenient attachment means could be used. FIG. 1 shows holes 116 in connector 110 that align with holes 136 on printed circuit board 132. Attachment might be by way of a screw or rivet through holes 116 and 136.
Printed circuit board 130 includes numerous surface mounted components, with component 134 being shown as illustrative. Conductive traces (not shown) on printed circuit board 130 connect these components to contact pads 132. Contact pads 132 are preferably evenly spaced with a pitch (spacing on center) of 0.025 inches. As shown in FIG. 1, contact pads 132 are aligned along an edge (not numbered) of printed circuit board 130.
FIG. 1 shows lead alignment tool 140 used to position tails 114 relative to contact pads 132. Tool 140 has a blade portion 144 which in use is held generally perpendicular to printed circuit board 130. Blade portion 144 is relatively thin so that it might be inserted between tie bar 120 and components 134 on printed circuit board 130. In a preferred embodiment, blade portion 144 has a thickness of approximately 0.025 inches.
Blade portion 144 has a plurality of openings 142 along its lower edge (not numbered). Openings 142 have a spacing which matches the spacing of tabs 122. Openings 142 are slightly larger than tabs 122, by approximately 0.005 to 0.001 inches. Blade portion 144 may thus be positioned so that openings 142 engage tabs 122.
FIG. 2 shows an enlarged portion of connector 110 and alignment tool 140. Openings 142 have a lower surface 240 which is tapered. Tab 120 has two surfaces 220 and 222 which are approximately at a 90° angle. Surfaces 220 and 222 form a means for engaging the tapered surface 240. The configuration of the pieces ensures that tool 140 and tab 120 engage in a predetermined and repeatable place.
Returning to FIG. 1, alignment tool 140 has an upper portion 148 positioned well above printed circuit board 130. Upper portion 148 is clear of the components 132 mounted to the surface of printed circuit board 130. Upper portion 148 can therefore be easily mounted to a fixture. FIG. 1 shows that upper portion 148 includes holes 150 that can be used to attach upper portion to fixture block 160.
Fixture block 160 includes a groove 164 which receives upper portion 148 to facilitate attachment of alignment tool 140 to the fixture. Fixture block 160 is movably mounted in a fixture (not shown). FIG. 1 shows that shaft 162 passes through fixture block 160.
Block 160 is mounted to shaft 162 by means of a slidable bearing (not shown) so that block 162 may be slid along shaft 162 and locked in place. Block 160 is slid in this fashion to obtain course positioning. For example, if two connectors such as connector 110 are mounted on a board 130, course positioning can be used to move between the two connectors.
Fine positioning of fixture block 160 is used for actual alignment of leads 114 to pads 132. In a preferred embodiment, shaft 162 is attached to a frame (not shown) by way of a fine pitch screw. Rotation of the screw causes transitional motion of shaft 162 along its axis. The screw (not shown) is preferably attached to a handle, motor or other means for rotating the screw (not shown).
In a preferred embodiment, shaft 162 is movably mounted in the fixture by some convenient means. Shaft 162, and therefore alignment tool 140, can move toward and away from connector 110 along a line parallel to printed circuit board 130. Shaft 162, and therefore alignment tool 140, can move toward and away from connector 110 along lines perpendicular or horizontal to printed circuit board 130. Such a movable mounting could be provided by a two axis carriage, such as is found in a pen plotter or similar device.
In use, connector 110 is attached to printed circuit board 130, such as by screws through holes 116 and 136. Board 130 is then inserted into the fixture (not shown) and affixed by any convenient means, such as clamps or spring clips.
Fixture block 160 is then moved parallel to printed circuit board 130 until blade portion 144 of alignment tool 140 is near, but slightly behind tie bar 120. Block 160 is then moved perpendicular to board 130 until openings 142 are at the same height as tabs 120. If necessary, fixture block 160 is moved along the axis of shaft 162 with course and fine motion, as described above.
Fixture block 160 is again moved towards connector 110 in a direction parallel to board 130. This motion inserts tabs 120 into openings 142.
Fixture block 160 is then moved perpendicular and away from board 130. This motion causes surfaces 220 and 222 (FIG. 2) of tab 120 to engage tapered surface 240 (FIG. 2) inside opening 142. It also causes the contact tails 114 to be lifted off the surface of printed circuit board 130.
Fine motion of fixture block 160, as described above, is then used to align contact tails 114 to contact pads 132. Alignment tool 140 includes an inclined region 146 between blade portion 144 and upper portion 148. Inclined region 146 ensures that fixture block 160 does not obscure the operator's view of the contact pads 132 and tails 114 during the alignment operation or soldering operation.
Once alignment is completed, alignment tool 140 is moved down and away from connector 110. This motion positions tails 114 on contact pads 132 and releases tabs 120 from alignment tool 140. Alignment tool 140 is then moved up and out of the way. The board is then ready for the contact tails 114 to be soldered to the contact pads.
Having described one embodiment, numerous alternative embodiments or variations might be made. For example, it is not necessary that a metal tie bar be used. A plastic tie bar could also be used.
A specific method of holding and positioning alignment tool 140 was described. Many alternative methods are possible. If an alternative positioning method is used, the sequence of motions in the alignment operation could change, but the end result of aligning the tails to the contact pads would be the same.
The figures illustrate that connector 110 has a single set of contact tails 114 which are soldered to the upper surface of printed circuit board 130. In general, printed circuit boards have contact pads on two surfaces Connector 110 might have a second set of contact tails engaging the lower surface of the board. In that case, once the contact tails are aligned with contact pads on one surface, board 130 could be flipped to align a second set of contact tails with the contact pads on the lower surface.
Also, a single way for the tie bar to engage the alignment tool was illustrated. Many other engagement mechanisms are possible. For example, holes 142 could be cut in the tie bar and the tabs could be formed in alignment tool 140.
As another variation, it was described that the alignment tool is removed after alignment of leads and contact pads. The tool could be keep in place to maintain the alignment during soldering, if desired.
Therefore, the invention should be limited only by the spirit and scope of the appended claims.
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A surface mount electrical connector incorporating features to facilitate alignment of contact tails to contact pads on a printed circuit board. The contact tails are held together with a tie bar. Tabs on the tie bar are shaped to engage features on a blade of an alignment tool. The blade can be inserted into the small available on the printed circuit board, but can be easily manipulated for precise alignment of the contact tails.
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This application is a National Stage completion of PCT/EP2010/070386 filed Dec. 21, 2010, which claims priority from German patent application serial no. 10 2010 000 857.5 filed Jan. 13, 2010.
FIELD OF THE INVENTION
The invention relates to a method for operating a vehicle drive train having a drive machine and having a transmission apparatus comprising a plurality of shift elements.
BACKGROUND OF THE INVENTION
Vehicle drive trains known in practice typically comprise drive machines implemented as internal combustion engines, which in each case can be brought into operative connection with an output drive; where the drive machines each have a transmission apparatus having a plurality of shift elements that can be engaged or disengaged for implementing different transmission ratios in a power flow. The output drive is coupled to a transmission output shaft and the drive machine is coupled to a transmission input shaft of the transmission apparatus.
During progressions of operating states, during which an output speed is greater than zero and a driver of the vehicle removes his foot from the gas and the vehicle coasts, in conventional operating mode of the vehicle drive train, the vehicle brakes itself due to engine braking by the drive machine that is running connected.
Drivers who drive in a fuel-saving manner often find this braking undesirable. For this reason, a vehicle, in the presence of various operating state parameters, during a previously described operating state progression, transfers into a so-called sailing mode during which the drive machine is decoupled from the output drive, for example in the region of the transmission apparatus by interrupting the power flow between the transmission input shaft and the transmission output shaft, and switched off. Then, the vehicle continues rolling without burning fuel and without hindrance from a braking moment from the drive machine, whereby vehicle fuel consumption is reduced.
However, a problem here is that with the presence of a request for coupling to, or for producing the power flow in the transmission apparatus between the transmission input shaft and the transmission output shaft, an undesirably long period of time is necessary before the power flow is produced again the region of the transmission apparatus.
SUMMARY OF THE INVENTION
Therefore, the problem addressed by the present invention is to provide a method for operating a vehicle drive train by means of which vehicle fuel consumption can be reduced, and with which a power flow can be produced in the region of a transmission apparatus within shorter operating times.
With the method according to the invention for operating a vehicle drive train having a drive machine, having a transmission apparatus with a plurality of shift elements, which are engaged or disengaged in a power flow for representing different transmission ratios, and having an output drive, wherein the output drive is coupled to a transmission output shaft and the drive machine is coupled to a transmission input shaft of the transmission apparatus, in the presence of a request to interrupt the power flow in the transmission apparatus between the transmission input shaft and the transmission output shaft, a maximum number of shift elements are transferred into and/or held in an engaged operating state, and the other portion of the shift elements are transferred into and/or held in a disengaged operating state, wherein the transmission output shaft is rotatable.
The procedure is based on the realization that in principle, engaged shift elements can be transferred into a disengaged operating state within a shorter operating time than disengaged shift elements being transferred into an engaged operating state. By transferring and/or holding a maximum number of a shift elements in an engaged operating state, and transferring into and/or holding the remaining portion of the shift elements in a disengaged operating state when there is a request for interrupting the power flow in the transmission apparatus between the transmission input shaft and the transmission output shaft, with a subsequent request for producing the power flow, the power flow can be produced in the region of the transmission apparatus within shorter operating times because for producing the power flow, it is preferred to disengage the shift elements rather than to engage them.
According to the invention, with a request to interrupt the power flow between the transmission input shaft and the transmission output shaft in an operating state of the transmission apparatus, in which a form-locking shift element in the transmission apparatus is disengaged, the form-locking shift element is engaged, when a differential speed in the region of the form-locking shift element is guided into a differential speed range, within which the form-locking shift element can be engaged, by engaging the sift elements after neutralizing the power flow. Thus, the vehicle drive train is already prepared during the interruption of the power flow for the later production of power flow in the region of the transmission apparatus in that to form-locking shift element to be transferred into an engaged operating sate for producing the power flow is, with the power flow interrupted, initially synchronized by a defined actuation of the shift elements, and is engaged in an at least nearly synchronous operating state.
Furthermore, fuel consumption of a vehicle drive train operated according to the invention, or fuel consumption of the drive machine, can be reduced in a simple manner in that the drive machine, preferably implemented as an internal combustion engine, is decoupled from the output drive and can be operated without burning fuel similarly to a sailing mode, known from the prior art.
In an advantageous variant of the method according to the invention, at a transmission input shaft speed that is greater than zero, and with a request for interrupting the power flow between the transmission input shaft and the transmission output shaft, the shift elements are transferred into and/or are held in the engaged or disengaged operating state.
With the power flow interrupted between the transmission input shaft and the transmission output shaft, if the transmission input shaft is held at least nearly without rotation by the engaged shift elements, then with interrupted power flow, the transmission apparatus is transferred into and held in a defined operating state in a simple manner, starting from which the power flow can be produced in the region of the transmission input shaft in a simple manner.
With nearly zero drive machine torque present at a transmission input shaft, if the transmission input shaft is held rotationally fixed by the shift elements, then stalling of the drive machine, implemented as an internal combustion engine, is avoided in a simple manner.
With a request for producing the power flow between the transmission input shaft and the transmission output shaft subsequent to the request for interrupting the power flow between the transmission input shaft and the transmission output shaft, when the speed of the transmission input shaft is adapted at least nearly to the speed of the transmission output shaft by actuating the shift elements to be transferred into an engaged operating state for representing the transmission ratio to be engaged in the transmission apparatus, then the vehicle drive train at this point in time at which the power flow is produced, is currently in a synchronous operating state without further measures, within shorter operating times.
In a further advantageous variant of the method according to the invention, if subsequent to a request for interrupting the power flow between the transmission input shaft and the transmission output shaft, there is a request for producing the power flow between the transmission input shaft and the transmission output shaft in an operating state of the transmission apparatus in which a form-locking shift element in the transmission apparatus is disengaged, which with the presence a request for producing the power flow is to be engaged, a differential speed in the region of the form-locking shift element is guided into a differential speed range, in which the form-locking shift element can be engaged, by setting the speed of the transmission input shaft on the side of the drive machine. Here, with low control and regulating expenditure, it is guaranteed that a form-locking shift element to be engaged for producing the power flow can be transferred within a predefined shift time into an engaged operating state, and the power flow can be made available in shorter operating times.
If the drive machine is switched off, with interrupted power flow in the transmission apparatus, reaction moments in the region of the output drive, resulting from the switching off procedure are avoided, which under circumstances would degrade driving comfort.
For representing a defined operating state with interrupted power flow in the region of the transmission apparatus and with the drive machine switched off, the transmission input shaft can be held rotationally fixed by actuation of the shift elements.
In a further advantageous variant of the method according to the invention, if subsequent to a request for interrupting the power flow between the transmission input shaft and the transmission output shaft, there is a request for producing the power flow between the transmission input shaft and the transmission output shaft, the drive machine is engaged before the production of power flow in the region of the transmission apparatus. With this, the drive machine is advantageously available for synchronizing the speed of the transmission input shaft and the speed of the transmission output shaft in order to be able to produce the power flow in the region of the transmission apparatus with the least possible loading in the region of the shift elements to be actuated.
If the drive machine is switched on after producing the power flow in the region of the transmission apparatus, the fuel savings is greater than with the latter procedure.
Further advantages and advantageous variants of the method according to the invention arise from the example embodiments described in the following based in principle on the drawings, where for the sake of clarity, in the description of the different example embodiments, components that are the designed the same way or are functionally equivalent are provided with the same reference numbers.
Features specified in the following example embodiments of the subject matter according to the invention are suitable, alone or in any arbitrary combination, to further develop the subject matter according to the invention. The respective combinations of features do not represent limitations with respect to the further development of the subject matter according to the invention, but rather merely comprise examples.
BRIEF DESCRIPTION OF THE DRAWINGS
The figures show:
FIG. 1 a highly schematic representation of a vehicle drive train;
FIG. 2 a gear set of a first embodiment of a transmission apparatus of the vehicle drive train according to FIG. 1 ;
FIG. 3 a shift pattern of the transmission apparatus according to FIG. 2 ;
FIG. 4 a gear set of a second embodiment of a transmission apparatus of the vehicle drive train according to FIG. 1 ; and
FIG. 5 a shift pattern of the transmission apparatus according to FIG. 4 .
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIG. 1 shows a vehicle drive train 1 having a drive machine 2 constructed here as an internal combustion engine, having a transmission apparatus 3 , by means of which different transmission ratios for forward and reverse travel can be represented, having a differential transmission unit 4 and having two vehicle axles 5 , 5 ′, wherein the vehicle axle 5 is the rear vehicle axle and the vehicle axle 5 ′ is the front vehicle axle.
A gear pattern of a first embodiment of the transmission apparatus 3 , or a multi-stage transmission, is shown in FIG. 2 , which is known in principle from the document DE 10 2008 000 429 A1. The transmission apparatus 3 comprises a transmission input shaft 6 and a transmission output shaft 7 , which is connected to the differential transmission input 4 in a state assembled in a vehicle, while the transmission input shaft 6 is operatively connected to the drive machine 2 .
Furthermore, the transmission apparatus 3 comprises four planetary gear sets P 1 to P 4 , wherein the first and the second planetary gear set P 1 , P 2 are preferably designed as minus planetary gear sets, forming a shiftable input side gear set, while the third and the fourth planetary gear sets P 3 , P 4 represent the main gear set. In addition, the transmission apparatus 3 comprises six shift elements A to F, where the shift elements C, D and F are implemented as brakes, and the shift elements A, B and E are implemented as clutches.
With the shift elements A to F, selective shifting of at least eight forwards gears “ 1 ” to “ 8 ” and one reverse gear “R” can be implemented, wherein for implementing a transmission ratio in the transmission apparatus 3 , or for producing a power flow in the transmission apparatus 3 between the transmission input shaft 6 and the transmission output shaft 7 , in each case, three shift elements are to be simultaneously guided into, or held in, an engaged operating state.
The shift elements A and F are designed here as form-locking shift elements in order to reduce drag torques, caused by disengaged frictionally engaging shift elements, in the operation of the transmission apparatus 3 , compared to transmission apparatuses that are designed having only frictionally engaging shift elements. Because form-locking shift elements in general can only be transferred from a disengaged operating state into an engaged operating state within a very narrow differential speed range around the synchronization speed, the synchronizing of a form-locking shift element to be shifted is supported, or fully implemented, without additional constructive designs by appropriately actuating the frictionally engaging shift elements or via engagement of the engine.
If the eighth transmission ratio “ 8 ” for forward travel is engaged in the transmission apparatus 3 , the shift elements C, D and E are held in the engaged state. With a request for a transmission ratio in a sailing mode of the vehicle drive train 1 , there is simultaneously also a request for an interruption of the power flow in the region of the transmission apparatus 3 between the transmission input shaft 6 and the transmission output shaft 7 . Additionally, the drive machine 2 is also to be switched off for representing the sailing mode.
In the process, the frictionally engaging shift element E is initially disengaged and the drive machine 2 is subsequently switched off. Actuation pressure of the shift element B is increased in a ramp-like manner until a differential speed in the region of the form-locking shift element A, presently as before in the disengaged state, is guided within a speed range within which the form-locking shift element A is at least nearly in a synchronous operating state, in which the form-locking shift element A can be transferred into an engaged state in a simple manner.
Because the drive machine 2 is switched off, it does not provide the drive torque necessary for the oil supply of the shift elements as a primary oil supply, which comprises a transmission oil pump operatively connected to the transmission input shaft 6 . For this reason, the transmission apparatus 3 comprises a secondary oil supply, not represented in more detail. This can be designed such that, with the drive machine 2 switched off, the hydraulic supply is provided by means of an electrically driven pump for example.
Along with the form-locking shift element A, the shift elements C and D are also held in an engaged operating state, whereby the shift elements A, B, C and D are in the engaged operating state in sailing mode S of the vehicle drive train 1 , or the transmission apparatus 3 . The power flow is interrupted between the transmission input shaft 6 and the transmission output shaft 7 , and the transmission output shaft 7 can rotate freely, while the transmission input shaft 6 is held rotationally fixed by the engaged shift elements A to D.
If following a request for interrupting the power flow in the region of the transmission apparatus 3 , there is a request for producing the power flow between the transmission input shaft 6 and the transmission output shaft 7 , initially the present operating state of the vehicle drive train 1 , or a speed of the output drive of the vehicle drive train 1 , is determined. If, based on the present determined operating state of the vehicle drive train 1 , starting with the sailing mode S, the seventh transmission ratio step “ 7 ” is to be engaged in the transmission apparatus 3 , the shift elements B and C are transferred into their disengaged operating state while the shift element E is engaged.
If, based on the present operating state of the vehicle drive train 1 in the transmission apparatus 3 , the sixth transmission ratio step “ 6 ” is to be engaged in the transmission apparatus, the shift elements B and D are disengaged, whereas the shift element E is engaged. If the fifth transmission ratio step “ 5 ” is to be engaged, the shift elements C and D are to be disengaged, whereas the shift element E is to be engaged.
Because a gear set group comprising the planetary gear sets P 1 and P 2 is blocked during the sailing mode S, the production of the power flow can be realized very quickly by an entry in the higher gear steps with simultaneous interruption of the sailing mode.
The speed of the transmission input shaft 6 is to be increased to a speed level equivalent to the speed level of the transmission output shaft 7 either by means of engaging the frictionally engaging shift element E, or the engaged drive machine 2 , depending on the application case.
With the transition into the sailing mode S, initially the power flow is basically interrupted by disengaging one or more of the shift elements A to F, and subsequently the drive machine 2 is switched off. After switching off the drive machine 2 , the planetary gear sets P 1 and P 2 are blocked by engaging and/or holding the shift elements A to D in the engaged operating state, wherein during this procedure the transmission elements of the transmission apparatus 3 coupled to the transmission input shaft 6 , or the speed thereof, are drawn down to zero.
With a transfer into sailing mode S, starting from the eighth transmission step “ 8 ”, the form-locking shift element shift element A is only engaged when the differential speed in the area of the form-locking shift element A approaches the value of zero. The gear set group of the transmission apparatus 3 comprising the planetary gear sets P 1 and P 2 remains blocked during the entire time of sailing mode S.
With exiting from sailing mode S, the power flow is produced in the transmission apparatus 3 in that the shift elements to be engaged for representing the requested transmission ratio in the transmission apparatus 3 are engaged, or are held in an engaged operating state, and subsequently a shift element of the gear that is to be selected or the target gear, that is still disengaged, is engaged, or synchronized. In general, this procedure allows the power flow to be produced in the region of the transmission apparatus 3 as quickly as possible with minimal volume required at the oil pump.
Based on the present operating state of the vehicle drive train 1 , starting with sailing mode S in the transmission apparatus 3 , if the first transmission ratio step “ 1 ”, the second transmission ratio step “ 2 ”, the third transmission ratio step “ 3 ” or the fourth transmission ratio step “ 4 ” are to be engaged, in each case, the further form-locking shift element F and two further shift elements A and D, A and C, A and B, or A and E are to be transferred into an engaged operating state.
Because the form-locking shift element A is already in the engaged operating state thereof during transition into the sailing mode S, the respective shift elements B and C, B and D, C and D or B to D, are to be disengaged, whereas one of the frictionally engaging shift elements D, C or B is to be held in the engaged operating state, or the frictionally engaging shift element E is to be transferred into the engaged operating state thereof. The form-locking shift element F is then engaged in the power flow, wherein synchronization of the form-locking shift element F is synchronized during the engine run-up of the drive machine 2 , or after completing the engine run-up via a defined engine engagement in the region of the drive machine 2 , and is subsequently engaged.
FIG. 4 shows a gear pattern of a second embodiment of the transmission apparatus 3 , which is designed having five frictionally engaging shift elements A to E and four planetary gear sets P 1 to P 4 . According to the shifting pattern shown in FIG. 5 , at least eight transmission ratios “ 1 ” to “ 8 ” for forwards travel and one reverse gear can be represented via the transmission apparatus 3 according to FIG. 4 , wherein for this purpose, in each case, three of the shift elements A to E are to be held in the engaged operating state, while the remaining shift elements are disengaged.
For representing the sailing mode S, the shift elements A, C and E are to be held in the engaged operating state, whereas the shift elements B and D are disengaged. In a simple manner, this attains that a maximum number of the shift elements A to E are engaged during sailing mode, the transmission output shaft 7 rotates freely, and simultaneously the transmission input shaft 6 is held rotationally fixed.
For leaving sailing mode S, in each case the transmission ratio that is suitable for the determined present operating state of the vehicle drive train 1 is to be engaged in the transmission apparatus 3 , for which purpose, the corresponding shift elements are to be guided into and/or to be held in, an engaged operating state, whereas the further shift elements are to be disengaged and/or to be held in the disengaged state.
REFERENCE CHARACTERS
1 vehicle drive train
2 drive machine
3 transmission apparatus
4 differential transmission unit
5 , 5 ′ vehicle axles
6 transmission input shaft
7 transmission output shaft
“ 1 ” to “ 8 ” transmission ratio for forward travel
A to F shift elements
P 1 to P 4 planetary gear set
S sailing mode
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A method of operating a vehicle drive train having a drive machine, a transmission apparatus having a plurality of shift elements and an output drive. The plurality of shift elements are engaged or disengaged in a power flow for achieving different transmission ratios within the transmission apparatus. The output drive is coupled to a transmission output shaft and the drive machine is coupled to a transmission input shaft of the transmission apparatus. Upon a request to interrupt power flow within the transmission apparatus, between the transmission input shaft and the transmission output shaft, a maximum number of shift elements are transferred to and/or held in an engaged operating state, and the remaining portion of the shift elements are transferred to and/or held in a disengaged operating state with the transmission output shaft being rotatable.
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FIELD OF THE INVENTION
The invention relates generally to an optical transmission filter and, more particularly, to an optical transmission filter containing a double-refraction element.
BACKGROUND OF THE INVENTION
Double-refraction optical transmission filters can consist of a double-refraction crystal plate arranged between two parallel linear polarizers. In such an arrangement the filter possesses the characteristic feature that the first polarizer in the direction of propagation of the light determines the polarization state with which the light of a wide-spectrum beam impinges upon the crystal. Because of the double refraction, which can be assumed generally without limitation to be a linear double refraction, the light beam is split into two beams polarized orthogonally and propagating at different velocities in the crystal. The light beam which issues from the crystal, and which results from the superposition of the two partial beams, exhibits generally elliptical polarization. The second polarizer, on the output side, is transparent only to the light beam component which is parallel to its plane of polarization and its transmission varies sinusoidally with the phase delay applied to one partial beam relative to the other because of the crystal double refraction. Since--without consideration of the variation in the effective index of refraction determined by the crystal material dispersion--said delay is approximately in inverse proportion to the wavelength of the incident light, the transmission is sinusoidally dependent on the inverse wavelength.
For a given wavelength λ of the light injected into the double-refraction crystal with a defined linear polarization state, the transmission is maximum in such a filter when the relative phase shift is 2π or an integral multiple ρ of 2π, determined by the difference in the two optical distances travelled by the two orthogonal polarization states. This can be written as the equation: ##EQU1## where p is the order in which the filter is operated at given wavelength λ.
This condition is met also for proximate wavelengths λ 1 =λ+Δλ 1 and λ 2 =λ-Δλ 2 when: ##EQU2## The wavelength intervals Δλ 1 ,2 for the transmission maxima of the filter transmission maximum for wavelength λ is then given by the equation: ##EQU3##
It is apparent that a given minimum distance Δλ between the transmission maxima of such a filter can be maintained only when the order in which the filter is operated is not larger than a maximum p max obtained from equation (3) for wavelength interval Δλ 1 of the "longer" wavelength when this equation is solved according to p: ##EQU4## This means that such a transmission filter, which for a wavelength λ of 480 nm is to have an interval Δλ of about 20 nm between transmission maxima, must be operated with a maximum order of p=25.
From equation (1) it follows directly that a calcite plate (Δn=about 0.16) with plane-parallel surfaces mounted as a double-refraction element in a transmission filter operated at a wavelength λ=500 nm with order 25, must present a thickness d of about 0.081 mm. For a satisfactory filter operation accuracy of about 1/100 of λ, thickness d.sub.λ within which a phase delay 2π occurs between the two orthogonal polarization states, is required, i.e. 30 nm or 1/17 of the wavelength. Therefore, the crystal plate must be processed with high accuracy, which naturally entails very high manufacturing costs for the filter. This is true also when, instead of a calcite plate, a quartz plate is used as a double-refraction element in which the difference Δn between the indices of refraction applicable to the two orthogonal polarization states is about 0.01. In this case the λ thickness is about 50,000 nm, and the tolerance acceptable for the quartz-plate thickness is about 500 nm, which is thus on the order of magnitude of the wavelength of the light to be filtered.
This disadvantage in the difficult and expensive production of such crystal plates applies particularly to filter arrangements in which a plurality of crystal plates are mounted in succession as a stack along the beam path. The first multilayer arrangement of this type was a filter proposed by Lyot (B. Lyot, Ann. Astrophys. 1944:7(1), 2). The Lyot filter comprises, for example, N plates stacked successively in the direction of light propagation, each plate being used with double the thickness of the preceding plates. Each plate is mounted with the polarizers crossed at a right angle. The optical axes of the double-refraction delay plates extend at 45° to the planes of polarization defined by the polarizers. The resulting transmission presents very definite transmission maxima with a stop-band which is determined by the plates of least thickness, and whose bandwidth decreases as the number of plates increases. Weakly marked secondary maxima also exist between the primary maxima. The transmission bandwidth obtainable with a Lyot filter comprising up to 10 plates is typically 5 to 0.5 A.
Similar narrow bandwidths are obtained with the multilayer double-refraction transmission filter suggested by Solc (I. Solc, Czechoslov. Cosopis pro Fysiku 1953:3, 336; 1954:4, 607, 609; 1955:5, 114). In a structure roughly equivalent to that of a Lyot filter with N plates, the Solc filter comprises, for example, m plates of equal thickness d equal to the thickness of the thinnest plates of the Lyot filter. The entire stack of plates is arranged between only two polarizers. The optical axes of the individual crystal plates are parallel to the plate surfaces and perpendicular to the direction of light propagation. In a first embodiment of the Solc filter the optical axes of the individual crystal plates are shifted fanlike by an angle
ω.sub.j =(ξ/2)+(j-1)ξ (5)
with
ξ=π/2m (6)
where m is the number of plates of equal thickness. The polarizers are parallel.
In a second equivalent embodiment the directions of the optical axes alternate successively at an angle
ω.sub.j =(-1).sup.j+1 (ξ/2) (7)
where equation (6) applies to ξ. The polarizers between which the stack of plates is arranged are crossed.
A further description of other properties of the Lyot filter and the Solc fan and folded filters can be found in a comparative description by John W. Evans (Journal of the Optical Society of America, Vol. 48, No. 3, March 1958, pp. 142ff.).
It is apparent that, because of the multiplicity of necessary crystal plates which must be processed with the above-cited accuracy, and the need to maintain exactly the orientation of the crystal-plate optical axes, the production of both the Lyot filter and the Solc filter is extremely complicated and expensive. Therefore, it is very difficult to tune such filters.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide filters of the above-cited type, but which are considerably simpler and cheaper to manufacture, and which users experienced with optical apparatus can adjust to the appropriate transmission range.
To achieve this and other objects, the present invention provides an optical transmission filter having at least one double-refraction element mounted between polarizers determining characteristic polarization states. The dimension of the double-refraction element, viewed in the direction of the light path, is sufficient to obtain a phase delay of at least 2π between orthogonal polarization states for at least one wavelength of the injected light. In particular, the double-refraction element is a single-mode optical fiber whose double refraction is sufficiently weak so that the length within which the light beams propagating with orthogonal polarization states in the fiber are mutually delayed by 2π is at least 1 cm.
In comparison to known filters comprising one or more double-refraction crystal plates the present invention provides for the advantage that the use of weakly double refractive optical fibers in which the minimum value of the λ length-comparable thickness of the crystal material used in known double-refraction filters is about 1 cm presents no special difficulty in observing a range advantageous to the processing of such fibers to transmission filters, and especially the tolerance of about 1/100 of the λ length required for the fiber length. There is also no difficulty in obtaining exactly the necessary fiber length of 1/10 mm by cutting the fiber to the required length or breaking off the fiber at designated break points by scratching the fiber surface to obtain in the fiber core a break surface extending with a very good approximation at a right angle to the fiber longitudinal axis. In a single-mode fiber core, diameters relatively small in comparison to the outer diameter are especially advantageous, so that even when the break surfaces are not exactly plane parallel, the resulting surface curvatures in the fiber core are negligible, which is necessary to avoid distorting the shape of the light beam. An optical fiber of the required length needs no subsequent processing before use in a double-refraction filter.
According to the present invention, the manufacture of narrow-band, fiber-optics transmission fibers similar to multilayer crystal filters is considerably simplified, so that they can be mass produced at low cost. This is significant in respect to the use of such filters is fiber-optics multiplex information transmission systems requiring a plurality of such filters.
The filter of the invention can also provide for manufacture-conditioned double refraction, inherent linear double refraction induced by pinching or bending the fiber, circular double refraction caused by fiber torsion, and elliptical double refraction resulting from the combination of linear and circular double refraction.
The present invention can also provide for fiber-optics transmission filters similar to the Solc fan filter by the combined utilization of inherent linear double refraction in a single-piece fiber extending between parallel polarizers, and elliptical double refraction obtained by twisting a portion of the fiber.
Further, the present invention can apply to fiber-optics transmission filters similar to the Solc fan and folded filters, with the necessary linear double refraction for such filters being obtained by pinching the fiber in suitable directions. Such filters in which the double refraction results from pinching the optical fiber offer the advantage of continuous adjustment by varying the pinching force in effect per length unit.
The present invention can also apply to produce filters similar to Solc fan and folded crystal filters. In this case, the double refraction required for filtering is obtained by bending the single-mode fiber in the form of loops placed so that the overall size of the filter is advantageously small and determined substantially by the diameter of the loops.
The fiber-optics transmission filter of the present invention, or a plurality of such filters, tuned to discrete wavelengths, is ideally applicable to fiber-optics transmission systems to separate the light signals transmitted from several semiconductor lasers and injected into a single-mode optical transmission fiber, thereby fully utilizing the highest possible information-transmission capacity in an optical communications transmission system.
BRIEF DESCRIPTION OF THE INVENTION
Other details and features of the present invention appear in the following description of embodiments in reference to the drawings, wherein:
FIG. 1 shows a Solc filter consisting of m double-refraction crystal plates;
FIG. 2 shows the angular distribution of the optical axes of the crystal plates in a Solc fan filter;
FIG. 3 shows the transmission curves illustrating a Solc filter;
FIG. 4 represents a filter consisting of sectionally twisted optical fibers according to the present invention;
FIG. 5 represents a Poincare sphere illustrating the operation of the filter;
FIG. 6 is a view of the Poincare sphere in the direction of arrow 89 in FIG. 5;
FIG. 7 shows a solid-core optical fiber pinched between two parallel compression jaws to produce linear double refraction in accordance with the present invention;
FIG. 8 shows an optical fiber bent to produce linear double refraction in accordance with the present invention;
FIG. 9 shows a pinching device used to produce specific, oriented linear double refraction in the successive sections of an optical fiber in accordance with the present invention;
FIG. 10 is a view of the pinching device in the direction of the longitudinal axis of the optical fiber in accordance with the present invention;
FIG. 11 shows a looped optical fiber used to obtain a Solc folded fiber in accordance with the present invention;
FIG. 12 shows diagrammatically a fiber-optics communications transmission arrangement comprising a plurality of transmission filters of the present invention; and
FIG. 13 shows the transmission curves of the filters of the arrangement represented in FIG. 12.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Turning now to the drawings, FIG. 1 schematically represents a Solc filter 20 consisting of m double-refraction crystal plates 21 and two linear polarizers 22 and 23 which will be discussed for providing further background of the present invention. About 1/100 of the above-defined thickness λ-thickness d.sub.λ of the crystal plates 21, characteristic of the light transmitted through the filter 20 at a determined wavelength, is the required tolerance. In the arrangement shown in FIG. 1 the crystal plates 21 are set up in a stack extending in the longitudinal direction of the central axis 24 of the light beam passing through the filter 20 between input polarizer 22 and output polarizer 23, with the facing plane parallel faces 27 in mutual contact and at a right angle to said axis 24. The optical axes (indicated by arrows 26 in FIG. 2) of the double-refraction crystals forming plates 21 are parallel to contacting plate faces 27.
In the embodiment designated as a Solc fan filter, the two polarizers 22 and 23 denote the horizonal direction of polarization marked in FIG. 1 by double arrows 28 and 29, and the optical axes 26 along which there is no double refraction in crystal plates 21 are arranged fanwise around central axis 24 in the arrangement of FIG. 2, according to the above equation (5). The angle formed by optical axes 26 with the direction 28 of polarization determined by input polarizer 22, seen in the direction of light path 24, increases by the same amount ξ=π/2 m from plate to plate. For white, unpolarized light entering the plate stack through input polarizer 22, the filter 20 provides for transmission which is dependent on the wavelength and whose qualitative variation is illustrated by the lower transmission curve 31 in FIG. 3. The relative transmission T, normalized to 1, is plotted against the wavelength λ.
As shown in FIG. 3, transmission T for the filter 20 of FIG. 1 exhibits strongly marked, narrow-band primary maxima 32 with transmission T=1 at the wavelength λ k for which equation (1) is fulfilled with the p integral, and whose interval on the wavelength scale is given by equations (3) and (2). Between the maxima 32, considerably less marked secondary maxima 33 and 34 appear at approximately equidistant intervals on the wavelength scale and are separated from each other and from primary maxima 32 by intermediate passages through zero 36 of transmission T.
The relative transmission of the filter 20 of FIG. 1 is represented generally by the following equation: ##EQU5## where the values χ are given by the expression ##EQU6## and ξ by equation (6), and ##EQU7## designates the half delay of the double-refraction crystal plates 21, d and Δn being as defined above.
FIG. 3 also shows a transmission curve 37 of substantially sinusoidal form which would be produced by a single crystal plate 21 instead of m crystal plates 21 between polarizers 22 and 23. It is apparent that in this case the transmission maxima 38 of said transmission curve 37 are separated by the same wavelength intervals as the primary maxima 32 of transmission curve 31 associated with multilayer Solc filters 20, but the bandwidth is much broader and corresponds approximately to the wavelength interval between transmission maxima 38, measured between the passages through zero 39 of transmission curve 37.
FIG. 4 represents a first embodiment of a fiber-optics transmission filter 40 of the present invention, with properties which are similar to those of the known Solc filter 20 of FIG. 1. The above equations are also applicable.
The central component of the fiber-optic transmission filter 40 is a quartz-glass, solid-core fiber 41 producing a linear double refraction of for example 100 rad/m. Optical fiber 41 is a single-mode fiber in which light can propagate only in two mutually orthogonal polarization states, which is the case when 2πd/λ(n k 2 -n M 2 ) 1/2 <2.4, where n k is the fiber core index of refraction and n M the fiber surface index of refraction. Preferably optical fiber 41 is a weakly guiding, single-mode fiber in which the difference between indices of refraction n k and n M is only about 0.5%. The fiber core diameter is about 5 μm and the outer diameter about 100 μm. Optical fiber 41 follows a straight line when extended, and is fixed against torsion at a number of clamping points 42, 43, and 44. The holding means necessary for this purpose are symbolized in FIG. 4 by retaining rings 47 attachable at definite intervals to an optical bench. But, of course, in practical cases the structure of these retaining means may be in other suitable forms to fix optical fiber 41 at intervals which will be specified below.
Clamping points 42, 43, and 44 divide optical fiber 41 into m delay sections 48, 49, and 50 and (m-1) coupling sections 51 between said delay sections 48, 49, and 50. The function of delay sections 48, 49, and 50 is similar to that of crystal plates 20 in Solc filter 20, and the function of coupling sections 51 is to connect the delay sections in the same distribution as shown in FIG. 2 in directions comparable to those of optical axes 26 of crystal plates 21, without the need of cutting the fibers into separate pieces.
Delay sections 49, arranged between pairs of coupling sections 51, are of equal length, which, for the given wavelength λ k corresponding to a transmission maximum of filter 40, is equal to (p+1) times the λ length l.sub.λk comparable to the λ thickness d.sub.λ of crystal plates 21, which is supplied by the equation:
l.sub.λk =(λ.sub.k /Δn) (11)
where Δn is the difference between the indices of refraction in effect for the two orthogonal polarization states possible in the filter, and on the order of magnitude of 10 -5 .
The length of first delay section 48 into which white light emitted by a light source 53, received by a focusing optical system 52, and injected with a linear polarization state determines by the position of a linear polarizer 54, is then equal to (p+1/4) times the λ length l.sub.λk. The length of the last delay section 50 must be (p+3/4) times the λ length. The coupling sections 51 are of equal length. A suitable length for the coupling sections 51 will be discussed below. A tolerance of about (l.sub.λk/ 100) is acceptable for fiber sections 48-50.
Coupling sections 51 are imparted with elliptical double refraction by twisting the fiber midway between clamping points 42 by a determined angle, symmetrically to a transverse axial plane 57 extending at a right angle to the longitudinal axis 56 of optical fibers 51. Said elliptical double refraction results from the fiber inherent linear double refraction β and a circular double refraction α determined by torsion. Viewed in the direction of the light beam, the first portions 58 of coupling sections 51 exhibit a left elliptical double refraction, while the next portions 59 thereof exhibit a right elliptical double refraction. The effect of this complementary elliptical double refraction in coupling sections 51 and the (l.sub.λk)/(4) "extra length" of first delay section 48, the total 2l.sub.λk of the extra lengths of delay section 49, and the 3/4l.sub.λk of the polarization state of the light of wavelength λ k propagating in optical fiber 41, is explained below in reference to FIGS. 5 and 6.
FIG. 5 represents a Poincare sphere 61 showing the possible linear polarization states by points located on the equator 62, the two possible circular polarization states (left circular polarization L and right circular polarization R) by the north pole 63 and the south pole 64, and the also possible left or right elliptical polarization states by other points on the surface of the sphere, above or below equator 62.
One linear double refraction present in optical fiber 41 is represented by a vector 67 located in the equatorial plane 66 and whose direction is indicated by the linear initial polarization state represented by points 68 and 69, whose introduction into optical fiber 41 along its length would not result in a change in the polarization state of the injected light. The direction 2φ B originates from the axes 71 associated as inherent polarization states represented by points 72 and 73 with the horizontal or vertical polarization of the incident light. If optical fiber 41 is oriented so that its optical axes are 72 and 73 and if light of a different linear polarization state represented, for example, by point 74, is injected into optical fiber 41, the polarization states occurring successively along fiber 41 progress possibly several times along a circle 76 extending around inherent polarization state 72, at an angular velocity β whose magnitude depends on the value of the linear double refraction represented by a vector 77 oriented toward point 72.
In FIG. 5 it is assumed that the progress along circle 76 occurs counterclockwise. A circular double refraction α impressed on an optical fiber 41, for example by twisting about its longitudinal axis, or which may be an inherent double refraction, is represented in the drawing of Poincare sphere 61 as a vector 78 or 79 oriented in the direction of polar axis 63 or 64. Vector 78, oriented toward north pole 63, indicates a left circular double refraction, and vector 79, oriented toward south pole 64, a right circular double refraction whose value is indicated in each case by the length of the vector. When a circular double refraction α is obtained by twisting the fiber with a determined degree of torsion π measured in rad/m, the value of the length of vectors 78 and 79 is given by the equation: ##EQU8## where
α.sub.τ =g·τ (13)
in which g is a constant factor ranging between 0.13 and 0.16 for normal quartz fibers.
When an optical fiber exhibits only pure circular double refraction and light in any polarization state is injected into said fiber, for example, with elliptical polarization by a point 80 of Poincare sphere 61, the polarization states occurring along the optical fiber are located on a circle 81 parallel to equator 62 and progress along said circle at an angular velocity determined by the value of vector 78.
If optical fiber 41 exhibits intrinsic linear double refraction represented for example by vector 77, and if, additionally, circular double refraction is impressed thereon by suitable torsion represented by vector 78, then generally fiber 41 exhibits elliptical double refraction resulting in FIG. 5 from the addition of vectors 77 and 78 to a resultant vector 82 which corresponds on the sphere surface to an induced polarization state 83.
If, instead of the left circular double refraction represented by vector 78, an equal right circular double refraction is impressed by vector 79 on fiber 41, in combination with the linear inherent double refraction represented by vector 77, the result is an elliptical double refraction represented by a vector 84 and the induced polarization state at a point 86 of sphere 61, said point being symmetrical to induced polarization state 83 relative to equatorial plane 66.
If light of, for example, linear polarization state 74 is injected into fiber 41, the polarization states occurring along said fiber 41 are located in one case on a circle 87 concentric to the polarization state 83, and, in the other case, on a circle 88 concentric to polarization state 86. In the selected special case said circles 87 and 88 are covered counterclockwise at the same angular velocity indicated by the value of vectors 82 and 84.
The length of the portions 58 and 59 of coupling sections 51 subjected to torsion-induced elliptical double refraction η is determined as one half of λ length l.sub.ηk applicable to the elliptical double refraction assumed to be given and which is shorter than the λ length l.sub.λ in delay sections 48, 49, and 50 of fiber 41, where only linear double refraction β is present. Considering equations 12 and 13, with a given degree of torsion τ and a given linear double refraction β the ratio l.sub.λk /l.sub.ηk of these λ lengths is given by the equation: ##EQU9## when g=0.13. Then the linear polarization state along portions 58 and 59 varies along a π arc of circles 87 and 88 extending around inherent polarization states 83 and 84.
Further to clarify the operation of filter 40 of FIG. 4, reference is made to FIG. 6, which is a view of Poincare sphere 61 seen in the direction of arrow 89. Without limiting the general concept it is assumed that the intrinsic double refraction of first delay section 48 is the horizontal state 72, and that the azimuth 2φ B of a polarization 74 injected into the first delay section is double the ellipticity +2Ψ B of the two elliptical inherent polarization states 83 and 86 of about 4°. Then the polarization state develops as follows along optical fiber 41. Light of wavelength λ k , injected with polarization state 74 into optical fiber 41, after covering a distance p·l.sub.λk in first delay section 48, exhibits again the same polarization state 74 determined by input polarizer 54, after covering circle 76 p times along this distance. In the rest of length l.sub.λk /4 to first clamping point 42 followed by first coupling section 51 extending to an end section 91, the polarization changes from linear polarization state 74 to polarization state 92 located on the great circle passing through poles 63 and 64. In the following first portion 58 of first coupling section 51, in which fiber 41 imparts left elliptical double refraction with inherent polarization state 83, the light polarization changes from elliptical polarization state 92 along a semicircle 93 with angular radius 2Ψ B to polarization state 72 which is a horizontal polarization in the special example. In the following section portion 59 of first coupling section 51 the polarization changes from linear polarization state 72 along second semicircle 95 with an angular radius 2Ψ B on unit sphere 61 to a right elliptical polarization state 94 located under equatorial plane 66 and extending to the second clamping point 42 of first coupling section 51. In the initial section 96 of length 3/4l.sub.λk following said clamping point 42 and second delay section 49 the polarization of the light passing through optical fiber 41 changes again from right elliptical polarization state 94 along circle 76 which extends concentrically around polarization state 72 to a linear polarization state 97 located in the left hemisphere of the Poincare sphere 61 in FIG. 6, and from which the polarization state 72 introduced into optical fiber 41 has an azimuth 4Ψ B =2φ B . After the additional length p·l.sub.λk of second delay section 49, the same polarization state 97 is obtained again after p cycles along circle 76. In the following end section 98 of length l.sub.λk /4, extending to the next clamping point 42, the polarization changes from state 97 to right elliptical polarization state 94 along circle 76. In the first portion 58 of the next coupling section 51 optical fiber 41 exhibits again the same left elliptical double refraction as in the first portion of the first coupling section, and the polarization changes from right elliptical polarization state 94, and a left elliptical polarization state 99 develops in the middle of the second coupling section 51 along a semicircle 101 extending on the surface of Poincare sphere 61 concentrically to left elliptical inherent polarization state 83 and having an angular radius 6Ψ B or 3φ B .
In the following second portion 59 of second coupling section 51 the light polarization changes from left elliptical polarization state 99 to a right elliptical state 102 along a semicircle 103 concentric to the directional axis of the vector of right elliptical inherent polarization state, and has an angular radius of 10Ψ B . From this right elliptical state 102 the polarization changes in the following, third delay section whose length is equal to that of the second in the initial section 96 of length 3/4l.sub.λk along a 3/4 circle 104 concentric to horizontal inherent polarization state 72, to a linear polarization state 106 which has again moved the further azimuthal distance 8Ψ B or 4φ B as the polarization state 97 reached at the corresponding point of the preceding delay section.
In the next portion of length pl.sub.λk of the third delay section 50 the polarization changes along a complete circle 104 covered counterclockwise p times. The variation in the polarization state along the next delay section 49 occurs exactly as explained above, and only the radius of the circles concentric to elliptic polarization states 83 and 86 and linear polarization state 72 varies in the manner illustrated in FIG. 6, to which reference is made for the details. This last delay section 50 is shorter by l.sub.λk /4 than the preceding delay section 49, so that the light decoupled at the end of the fiber by a collimator lens 107, an output polarizer 108 similar to polarizer 23 in FIG. 1, and a suitable photoelectric detector 109, exhibits a linear polarization state.
The azimuthal distances between linear polarization states 74, 97, 106, etc., in effect at the end of each delay section are 8Ψ B or 4φ B . Therefore, the effect of coupling section 51 of elliptical double refraction induced by twisting between delay sections 48, 49, and 50, is totally identical to that of the fanlike orientation of the optical axes 26 of individual crystal plates 21 in the Solc filter of FIG. 1 when the azimuthal distance between the linear polarization states in effect at the outputs of the individual delay sections is adjusted by appropriate setting of the degree of torsion τ according to equations (5) and (6). As directly apparent from FIG. 5, 2Ψ B is determined by the equation: ##EQU10## or, in consideration of equation (13) ##EQU11## for g=0.13. The value 2π/m of said azimuthal distance to be set according to equation (6) must be equal to 4 times the value of the angle indicated by equation (16), so that: ##EQU12## The length of coupling section 51 is then established according to equation (14) by the degree of torsion as in equation (17).
A linear double refraction with the orientation required for a filter effect of the type of a Solc fan or folded filter according to equation (5) or (7) can also be impressed on an optical fiber 110 by pinching and/or bending. When the fiber is pinched between jaws 111 and 112 as shown in FIG. 7 with a force applied at a right angle to its longitudinal axis 113 as symbolized by opposite-direction arrows 114 and 116 in FIG. 7, optical axes 117 and 118, along which the fiber exhibits the greatest or the least index of refraction, extend in the direction 114, 116 of the applied pinching force and at a right angle thereto. In the case of a fiber 110 of 100 μm diameter the pinching force necessary to obtain a double refraction of about 2π/m is about 1 N. This force may be localised or distributed along a greater length of the opposite surface lines of the fiber.
When, for example, an optical fiber 120 is curved, especially in the form of a loop as shown in FIG. 8, and laid in one plane 121, two axes 122 and 123, corresponding to the extreme values of the effective index of refraction, are present. Axis 122, associated with the maximum value of the index of refraction, extends in the radial direction of the effective radius of curvature, and axis 123, associated with the minimum value of the index of refraction, is perpendicular to the plane of curvature 121. The value of the linear double refraction resulting from the flexure of fiber 120 depends on the fiber radius of curvature, and can therefore be adjusted by a suitable choice of the radius.
In solid-core fibers, the linear double refraction is approximately proportional to the square of the reciprocal radius of curvature. In addition, it also depends on the diameter of the fiber itself. A double refraction of about 4π/loop is obtained in a quartz-glass fiber laid in closed circular loops of about 10 cm diameter when the fiber diameter is approximately 100 μm. FIGS. 9 and 10 show the basic structure of a pinching device 124 and the successive, equal-length sections of an optical fiber 110 exhibiting equal amounts of linear double refraction. The device is capable of imparting the orientation of double-refraction axes 117 and 118 necessary to obtain a fiber-optics Solc folded filter according to equation (6).
Pinching device 124 comprises two pinchers 126 and 127 shown in plan view in FIG. 9 and in a view in the direction of the longitudinal axis 128 of optical fiber 110 in FIG. 10. The details of said device require no specific explanation. Pinchers 126 and 127 can be placed from opposite sides on straight optical fiber 110, so that the pair of pinching jaws 129, 130 of pincher 126 and the pair of pinching jaws 131, 132 of the other pincher 127 alternately engage optical fiber 110, as viewed in the longitudinal direction of said fiber. The median planes 133 and 134 of the pincher gap, evidenced by the central axis 128 of the optical fiber and the pivot axes 136 and 137 of the jaws 129-132 of the two pinchers 126 and 127, enclose an angle of 180°-ξ, where ξ is applied by equation (6), i.e. amounts to 15° in the illustrated embodiment comprising a total of 6 alternating pairs of pinching jaws 129, 130 and 131, 132. The pinching forces applied in the direction of arrows 138, 139 and 140, 141 are defined for example by tension screws 142 and 143 engaging jaws 126 and 127. It is apparent that the pinching device and the adjustment and orientation of the pinching forces applied to optical fiber 110 can also be provided by other equivalent means.
A similar arrangement for the production of a fiber-optics Solc folded filter is represented in FIG. 11. The double refraction necessary to the filter effect is impressed here on an optical fiber 120 by bending the fiber. Optical fiber 120 is arranged in closed loops 144 and 145 which overlap alternately in different loop planes 146 and 147 enclosing an angle of 180°-ξ. Each loop 144 or 145 corresponds to a delay section of determined length. Instead of one loop, groups of loops comprising a plurality of loops can be provided to form a delay section. Advantageously, to position optical fiber 120, loops 144 can be placed in one loop plane 146, and loops 145 in the other loop plane 147, in opposite looping directions.
It is understood that the above-cited means to obtain the necessary double refraction and/or to connect the double-refraction delay sections can be used in combination. For example, a Solc fan filter can be obtained by applying the pinching forces in fanlike distributed directions of action to an extended optical fiber. It is possible also to connect delay sections to which the necessary double refraction is imparted by bending--the loops or bends of the individual delay sections being in a common plane--coupling sections obtained as described in reference to FIG. 4. A fiber-optics Solc fan filter with looped delay sections may also be produced by arranging the loops in fan- or star-shaped planes.
FIG. 12 represents schematically a fiber-optics arrangement 150 consisting of optical-fiber transmission filters of the invention, which in particular may present the structure described in reference to FIG. 4 or FIGS. 9-11. Said arrangement provides for the decomposition into components practically without loss of a signal light beam which is guided by a single optical fiber 151 and comprises a plurality of partial light beams of different wavelength, which are assumed to be monochromatic within a narrow band width δλ. Arrangement 150 is usable, for example, in a fiber-optics communications transmission system to separate and process individually partial light beams of different wavelength used as carriers for different information and normally pulsed in a manner characteristic of the information concerned.
In the illustrated embodiment of FIG. 12, it is assumed for simplicity that the signal light beam 152 comprises four partial light beams whose spectral intensity distribution around central wavelengths λ 1 , λ 2 , λ 3 , and λ 4 are represented by narrow-band intensity maxima 153 in the first family of curves of FIG. 13. It is assumed also that the partial light beams guided by an optical fiber 151 are fully polarized. Arrangement 150 contains four fiber-optics transmission filters 154-157 whose transmission behavior is adapted to the spectral distribution of the parallel light beams as apparent from FIG. 3, so that only one transmission maximum 32 (see FIG. 3) of filters 154-157 coincides with one of the signal light waves λ 1 -λ 4 . The illustrated variation of the transmission curves related to filters 154-157, preferably in the same order, can be obtained by suitable selection and/or tuning of the double-refraction properties of the optical fibers.
The structure of a filter arrangement 150 as illustrated in FIG. 12, is set up so that signal light beam 152 containing all the partial light beams impinges first on filter 154 whose effective transmission maximum 36 is adjusted to wavelength λ 1 . The linear polarization state of the light injected into first filter 154 necessary for the appropriate operation of said filter is obtained by the suitable adjustment of an optical phase compensator, for example a Soleil-Babinet compensator 158. The plane of polarization of the light issuing from compensator 158 and injected into the optical fiber of first filter 154, forms the reference plane for the directions in which the above-cited double-refraction properties are imparted to the optical fibe of filter 154 by lateral compression, bending, or the like. The output polarizer of first filter 154, comparable to the output polarizer 108 of FIG. 4, forms a polarizing prism which, for example in the extraordinary output path, deflects the partial light beam of wavelength λ 1 , to which first filter 154 is tuned, to a first detector 160, and, in the ordinary output path, injects the residual partial light beams of wavelengths λ.sub. 2, λ 3 , and λ 4 with a linear polarization state, into the optical fiber of second filter 155. The output polarizer of second filter 155 or the input polarizer of third filter 156 forms another two-output polarizing prism 161 which directs the partial light beam of wavelength λ 2 to another detector 162 and the residual partial light beams of wavelengths λ 3 and λ 4 to third filter 156. A third two-output polarizing prism 163 constituting the output polarizer of third filter 156, finally, over its extraordinary and ordinary output light paths, provides for the necessary spatial separation of the residual partial light beams of wavelengths λ 3 and λ 4 for the separate informations with detectors 164 and 166. A fourth filter 157, shown by broken lines in FIG. 12, is needed only when filters tuned to other wavelengths (λ 5 , . . . λ n ) must be connected in a similar way over an additional polarizing prism 167. Polarizing prisms appropriate to arrangement 150 are, for example, the Rochon prism, the Senarmont prism, and the Wollaston prism.
A system adapted to the same application as the arrangement 150 of FIG. 12 can be obtained by introducing after optical fiber 151 guiding the total light beam a multiple beam splitter device to divide primary light beam 152 into a number of spatially separate light beams of approximately equal intensity, corresponding to the number of partial light beams of different wavelength. In this case a narrow-band transmission filter of the invention, adapted to the wavelength to be filtered, is provided in the path of each of said light beams.
It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of this invention. Numerous other arrangements may be readily devised by those skilled in the art which embody the principles of the invention and fall within its spirit and scope.
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In manufacturing optical transmission filters having double-refraction elements, extreme care is usually necessary to provide the desired phase delay. To simplify the manufacturing process while still achieving accurate phase delay, a filter is provided with at least one double-refraction element comprising a single-mode optical filter mounted between polarizers. The double refraction of the optical fiber is sufficiently weak so that the λ length within which light beams propagating with orthogonal polarization states in the fiber are mutually delayed by 2π, is at least 1 cm. In one embodiment, the optical fiber comprises alternating sections which produce linear double refraction with sections which produce elliptical double refraction.
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FIELD OF INVENTION
[0001] This application relates generally to multi-element transducers used for delivering high intensity acoustic energy from a multi-element transducer, e.g., a high density, two-dimensional phased-array transducer.
BACKGROUND
[0002] It is well-known to use high intensity, focused acoustic wave energy, such as ultrasonic waves (i.e., acoustic waves having a frequency greater than about 20 kilohertz) to generate thermal ablation energy for treating internal body tissue, such as tumors. It is also well-known to employ an imaging system, such as a MRI system, in order to guide the delivery of such high intensity ultrasound energy to the targeted tissue area, and to provide real-time feedback of the actual delivered thermal energy. One such image-guided, focused ultrasound system is the Exablate® 2000 system manufactured and distributed by InSightec Ltd, located in Haifa, Israel (www.Insightec.com).
[0003] By way of illustration, FIG. 1 is a simplified schematic representation of an image-guided, focused ultrasound system 100 used to generate and deliver a focused acoustic energy beam 112 to a targeted tissue mass 104 in a patient 110 . The system 100 employs an ultrasound transducer 102 that is geometrically shaped and physically positioned relative to the patient 110 in order to focus the ultrasonic energy beam 112 at a three-dimensional focal zone located within the targeted tissue mass 104 . The transducer 102 may be substantially rigid, semi-rigid, or substantially flexible, and can be made from a variety of materials, such as plastics, polymers, metals, and alloys. The transducer 102 can be manufactured as a single unit, or alternatively, be assembled from a plurality of components. While the illustrated transducer 102 has a “spherical cap” shape, a variety of other geometric transducer shapes and configurations may be employed to deliver a focused acoustic beam, including linear (planar) configurations. The ultrasound system 100 may further include a coupling membrane (not shown), such as an inflatable body or a balloon filled with degassed water, for providing or improving the acoustic coupling between the transducer 102 and the skin surface of the patient 110 .
[0004] The transducer 102 may be formed of relatively large number of individually controlled elements 116 mounted on a distal (outward) facing surface 118 (best seen in FIG. 2 ) of the transducer 102 . Each transducer element 116 may itself comprise one or more (adjacent) piezoelectric members electrically connected to a same drive signal supplied from a system controller 106 . During operation, the individual piezoelectric members each contribute a fractional part of the ultrasound energy beam 112 by converting the respective electronic drive signal into mechanical motion and resulting wave energy. The wave energy transmitted from the individual piezoelectric members of the transducer elements 116 collectively forms the acoustic energy beam 112 , as the respective waves converge at the focal zone in the targeted tissue mass 104 . Within the focal zone, the wave energy of the beam 112 is absorbed (i.e., attenuated) by the tissue, thereby generating heat and raising the temperature of the tissue to a point where the cells are denatured (“ablated”).
[0005] An imager (e.g., an MRI system) 114 is used to generate three-dimensional images of the targeted tissue mass 104 before, during, and after the wave energy is delivered. The images are thermally sensitive so that the actual thermal dosing boundaries (i.e., the geometric boundaries and thermal gradients) of the ablated tissue may be monitored. The location, shape, and intensity of the focal zone of the acoustic beam 112 is determined, at least in part, by the physical arrangement of the transducer elements 116 and the physical positioning of the transducer 102 . The location, shape, and intensity of the focal zone may also be controlled, at least in part, by controlling the respective output (e.g., phase and amplitude) of the individual transducer elements 116 by a process known as “electronic steering” of the beam 112 . Examples of such physical positioning systems and techniques, and of electronic beam steering, including driving and controlling the output of individual transducer elements, can be found in U.S. Pat. Nos. 6,506,154, 6,506,171, 6,582,381, 6,613,004 and 6,618,620, which are all incorporated by reference herein.
SUMMARY OF THE INVENTION
[0006] In accordance with one aspect of the invention, an ultrasound transducer comprising a multiplicity of transducer elements arranged in a two-dimensional array, the transducer elements each comprising one or more piezoelectric members that collectively form an energy transmitting surface of the respective transducer element, the energy transmitting surface having a geometric center, wherein the respective transducer element geometric centers are in an irregular formation. By way of non-limiting examples, the transducer element surfaces may have irregular shapes and/or differing effective lengths. Such differing shapes may be rectilinear, curve-linear, or a combination of each, and may include shapes such as an L-shape, a rectangular shape, a square shape, a T-shape, and an S-shape. The transducer element shapes may be far more complex, similar in appearance as the pieces of an assembled jigsaw puzzle. By constructing the transducer array out of non-uniform (irregular shaped) elements, the resulting geometric centers of the elements are also non-uniform, and the effective range of electronic steering of the transducer may be increased over that of a conventional transducer array having uniform-shaped energy transmitting element surfaces, without formation of potentially harmful and energy depleting hot spots.
[0007] Other and further aspects and features of various embodiments of the invention will become evident from the following detailed description and accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is simplified schematic diagram of an image-guided focused ultrasound treatment system for providing thermal energy dosing of a targeted tissue region in a patient.
[0009] FIG. 2 is a cut-away schematic side view of the ultrasound transducer used in the system of FIG. 1 , illustrating a concentrated emission of focused ultrasonic energy originated from a multiplicity of individual elements to a focal zone in the targeted tissue region.
[0010] FIG. 3 is a top view of a conventional two-dimensional array of transducer elements having uniform (rectangular) energy transmitting surfaces.
[0011] FIG. 4 illustrates the principle of electronic steering, and a resulting “steering angle” when transmitting to a “steered-to” focal zone using with a uniform transducer array.
[0012] FIG. 5 is a graph plotting the half energy or “steering ability” of a transducer element of the array, based on its size.
[0013] FIG. 6 is a chart depicting the relationship between the “directivity” of a transducer element of the array and an energy flux calculation in Fourier space for differently sized transducer elements, 1 λ and 3 λ.
[0014] FIG. 7 is a comparison of hot spots created by electronic steering from linearly arranged transducer elements having a size d=λ to respective 15° and 30° steering angles.
[0015] FIG. 8 is a top view of a two-dimensional array of transducer elements having irregular shaped energy transmitting surfaces, in accordance with one embodiment of the invention.
[0016] FIGS. 8A and 8B illustrate one technique for forming the non-uniform transducer elements in the array of FIG. 8 .
[0017] FIG. 9 is a top view of another two-dimensional array of transducer elements having irregular shaped energy transmitting surfaces, in accordance with another embodiment of the invention.
[0018] FIGS. 10A and 10B are top views of further two-dimensional transducer arrays having irregular shaped energy transmitting elements, in accordance with yet further embodiments of the invention.
[0019] FIGS. 11A-B , 12 A-B, 13 A-B, 14 A-B and 15 A-B are images generated by 3-D simulations of respective converging acoustic energy beams transmitted from a multi-element transducer having uniform-shaped elements ( FIGS. 11A , 12 A, 13 A, 14 A and 15 A), or irregular shaped elements ( FIGS. 11B , 12 B, 13 B, 14 B and 15 B).
DETAILED DESCRIPTION
[0020] High density ultrasound transducers have been developed in which the transducer is produced in the form of a two-dimensional grid of uniformly shaped piezoelectric (PZT) “rods” glued to a conductive matching layer substrate. For both manufacturing and performance reasons, the PZT rods have rectangular (or square) profiles, with an aspect ratio (i.e., ratio of height/width) of greater than or equal to one, and are preferably uniform in size to produce the same frequency response. Spacing between the rods also influences the acoustic performance of the transducer and is preferably minimized, i.e., much smaller than the size of the individual piezoelectric rods, for therapeutic transducers. A high density phased array transducer may have hundreds, even thousands of densely packed piezoelectric rods, each having a relatively small energy transmitting surface, e.g., 1 mm square.
[0021] An example of one such high density transducer array 130 of uniformly shaped piezoelectric rods is shown in FIG. 3 . The transducer array 130 comprises a two-dimensional arrangement of individual piezoelectric rods 132 glued to a planar substrate. The piezoelectric rods 132 are substantially identical in size and shape, including having substantially uniform (square) distal facing energy transmitting surfaces 134 (also square). The rods 132 are arranged in uniformly aligned columns 135 and rows 136 , with minimal spacing provided between adjacent rods. It will be appreciated that the relatively small transducer rod size allows for greater electronic steering capability of the overall array. However, as the “steering angle” increases, hot spots start to appear outside of the intended focal zone.
[0022] More particularly, the independent piezoelectric rods 132 in such known arrays 130 are typically produced using a dicing machine that can dice along straight lines only. Each rod is connected to its own electronic drive signal input, such that each rod forms a distinct transducer element. From a physical point of view, the acoustic performance (e.g., frequency response, efficiency, etc) of the array 130 is influenced by the three dimensional structure of the individual rods 132 , and preferably each rod's height should be equal or higher than its width. However, the steering/focusing ability of the transducer array 130 is fully defined by the geometrical surface (i.e., the area of a transducer element that emits a respective acoustic wave at a same phase) of the respective rods 132 . All internal transducer structure aspects, such as piezoelectric rod height, aspect ratio, etc, are irrelevant to steering/focusing ability.
[0023] As used herein, the term “hot spot” refers to a tissue region having an energy level (which may be measured, for example, in terms of temperature or acoustic pressure) that is above a prescribed (safe) level at which the tissue in the hot spot will be temporarily or permanently injured. Because such hot spot(s) start to appear as the electronic steering angle increases, electronic steering to each possible “steered-to” focal zone must be carefully analyzed for safety purposes before undertaken. Further, the energy absorbed at the hot spot(s) decreases the remaining energy available for contributing to the intended “steered-to” focal zone.
[0024] FIG. 4 illustrates the principle of electronic steering of a two dimensional planar array 150 comprised of uniformly shaped and arranged elements (such as array 130 of FIG. 3 ). In particular, the “steering angle” of any one transducer element 154 of the array 150 is the angle α formed between a first focal axis 152 extending generally orthogonally from the element to a “non-steered” focal zone 158 at which the element 154 contributes a maximum possible power, and a second focal axis 156 extending from the transducer element 154 to a “steered-to” focal zone 160 . The “steering ability” of the transducer array 150 is defined as a steering angle α at which energy delivered to the steered-to focal zone 160 from a given one-dimensional element row falls to half of the maximum power delivered to the non-steered focal zone 158 .
[0025] Notably, the steering angle if each transducer element of a phased array will be different. However, as the distance to a steered-to focal zone increases, the respective steering angles for the array elements approach the same value. For ease in illustration, the distance of the steered-to focal zone in the simulations in FIGS. 5-7 is assumed to be infinity, so that the steering angles of each array element is the same.
[0026] From a physical point of view, a single transducer element emits a wave in the form of a spreading beam. The angular distribution of this spreading beam is called “directivity.” While a single element of an array (if it is the only element that is activated), cannot produce a focused beam, an array of activated elements can produce focused beam, where the size of the “focus” is smaller when transducer elements have larger emitting surface areas. Each transducer element contributes to the focus proportionally to the value of its directivity at the ‘focus.” Thus, the steering region of a phased array transducer is dependent on each element's directivity patterns.
[0027] By way of further illustration, FIG. 5 depicts the relationship between a transducer element surface size and its steering ability, represented in terms of its half-energy angle. For purposes of illustration, there are two curves shown in FIG. 5 . There are two curves shown in FIG. 5 ; one (labeled “1 el direct”) is a simplified analytical result of the element's directivity; the other (labeled “real calc”) is a numerical simulation for a phased array transducer. As can be seen, for a transducer element having a size d/λ, where λ is the wavelength of the wave emitted by the element, the half energy steering angle, or “steering ability,” of the transducer array with d/λ=1 is 30°, which is the angle at which a steered-to focal zone has an energy level equal to half the maximum energy that the transducer would contribute to a non-steered focal zone.
[0028] In order to better illustrate the relationship between the electronic steering angle and formation of hot spot(s), consider a one-dimensional array (i.e., row) of transducer elements having a cross sectional dimension (i.e., element surface size) of d/λ=1. If Δφ is a phase difference between neighboring elements of the array, maximum energy emission occurs at angles satisfying the relationship: sin(α)=(n+Δφ/2π)λ/d , where λ is an ultrasound wavelength, integer n=0 for the main focus and n≠0 for hot spots. Thus, where d≦λ/2, no hot spots will be formed. As such, the advantages of the embodiments described below particularly apply where the element size is equal to or greater than one-half of the drive signal wavelength.
[0029] The electronic steering ability of a transducer device can be defined by:
[0000]
I
s
≡
Energy
at
main
focus
All
emmited
energy
.
For d>>λ, the steering ability approaches single element “directivity,”
[0030]
I
d
=
(
sin
(
π
d
sin
(
α
)
/
λ
)
π
d
sin
(
α
)
/
λ
)
2
.
FIG. 6 shows a comparison of this directivity formula to energy flux calculation in Fourier space for two different ultrasound wavelengths, 1 λ and 3 λ.
[0031] As a result of the hot spot generation, large steering angles cannot be practically used, since nearly all of the energy that does not go to the steered-to focal zone is concentrated at hot spots. As can be seen in FIG. 7 , for d=λ, while attempting to steer to 30°, hot spots are produced at −30° of equal intensity as the main focus, reducing the steering ability that can be safely used to about half of the main focus steering ability. It will be appreciated by those skilled in the art, that as the steering angle amplitude (absolute value) increases, hot spots begin to appear at numerous different points, and are both uncontrollable and undesirable.
[0032] In accordance with a general aspect of the invention, a high density, two-dimensional transducer array is formed using transducer elements having irregular shaped energy transmitting surfaces. In various embodiments, the transducer element surface shapes may have rectilinear or curve-linear profiles, or a combination of both, and may include many different types of “irregular” shapes. By way of example, a multi-element transducer array 200 constructed according to one embodiment of the invention is shown in FIG. 8 . In particular, the multi-element array 200 comprises irregular shaped transducer elements 202 having at least five different element shapes, including an L-shape 202 a , a rectangular (or “I”) shape 202 b , a square shape 202 c , a T-shape 202 d , and an S-shape 202 f , respectively, which are mounted to a substrate 204 in an interlocking (or mating) configuration, resembling a “Tetris” game formation.
[0033] The array 200 may be constructed, by way of example and not limitation, using a conventional dicing machine, but making much smaller cuts to create a uniform array of piezoelectric rods in the same formation as shown in FIG. 3 . However, the individual rods are then coupled to a same electronic drive signal in order to form the irregular shaped elements 202 of the array 200 . For example, as shown in FIG. 8A , an L-shape element 202 a may comprise three adjacent and aligned square rods 206 a - c , along with a forth rod 206 d located adjacent to the third rod 206 c and orthogonal to the alignment of rods 206 a - c . Similarly, as shown in FIG. 8B , an S-shape element 202 e may be formed by electrically coupling four square rods 208 a - d in an S-shape formation. It should be appreciated, however, that the transducer elements 202 may also be formed by one-piece piezoelectric elements, instead of a mosaic arrangement of smaller component elements.
[0034] While the array 200 of FIG. 8 has a generally planer configuration, it is possible for such irregular shaped transducer arrays to employ other configurations. For example, a spherical cap transducer array 220 having irregular (“Tetris”) shaped elements 222 is shown in FIG. 9 . Moreover, the “Tetris” shapes of FIGS. 8 and 9 are but two examples of transducer arrays having non-uniform transducer elements. Multi-element arrays 240 and 230 having more complex, pseudo random shaped elements 242 and 232 , respectively, are shown in FIGS. 10A and 10B . Notably, the elements 242 and 232 have curve-linear profiles instead of the rectilinear profiles of elements 202 and 222 of arrays 200 and 220 , respectively.
[0035] In the various embodiments contemplated by the invention, the irregular shaped elements of a transducer array preferably have the same or similar total surface areas, e.g., with each element being formed by connecting a same number of smaller piezoelectric elements in differing patterns. However, it is acceptable that some elements of the transducer array have differing surface areas, (such as elements 210 and 212 in array 200 , which may be formed out of five, instead of four, square rods). Although the surface areas of the respective elements of an array may differ, they will still respond to the same frequency, while possibly producing slightly different amplitudes (depending on whether any compensation is made to the drive signal current, which is spread over a lesser or greater surface area).
[0036] Further, it will be appreciated that the elimination of hot spots in embodiments of the present invention is due to the non-uniform locations of the geometric centers of the respective transducer elements 202 . In particular, the geometrical “centers” of neighboring elements 202 of the array are randomly shifted by the length of the element comparable with its size (e.g., anywhere from a ratio of 1/4 to a ratio of 1/1). In contrast, in a conventional “uniform” transducer arrays the geometric centers of the elements are “ordered” along straight lines or circles. In a therapeutic focused ultrasound system, it is desirable to deliver maximal energy delivery to the focal zone and minimal energy to any other locations. This is normally achieved by maximal transducer area coverage by emitting elements.
[0037] Thus, in embodiments of the present invention, “random order” may be obtained while retaining full area coverage by emitting elements by using “irregular shaped” and/or “irregular oriented” transducer elements. While this results is some “smearing” of the acoustic waves and, thus, some (relatively small) corresponding loss of energy intensity at the focal zone, the steering capability of the respective array greatly exceeds that of a conventional uniform-shaped transducer array of otherwise similar element size. In particular, the appearance of hot spots is greatly decreased by the element disorder of an irregular shaped array, while the main focal zone has only a minor power degradation. Further, the element size may be much larger than the acoustic wavelengths that are used. Many different irregular shape patterns are possible within the ambit of the invention, with the particular element pattern realized on the substrate specifically chosen depending on the particular steering angles to be achieved without the formation of prohibitive hot spots. Because of the disorder in the waves caused by the irregular element shapes and positions, only the main focus survives. The use of an irregular shaped array for improved electronic steering when delivering therapeutic levels of ultrasound energy is fundamentally different from a (known) “parsing” technique used for ultrasound imaging, in which gaps (uniform or varied) between elements are used to increase steering performance. While a similar effect may be achieved by irregular spacing of the elements, this would result in large gaps and unacceptable losses in output power in the case of a therapeutic transducer application. Further, the gaps between elements causes more spreading in space of the acoustic energy for the same focal zone power delivery, which in turn may cause excessive heating of the surrounding tissue.
[0038] The effect of the reduction in hot spots and the benefit of using the irregular shaped transducer array 200 of FIG. 8 versus the uniform-shaped transducer array 130 of FIG. 3 may be demonstrated with reference to FIGS. 11A-B , 12 A-B, 13 A-B, 14 A-B and 15 A-B. In particular, images generated by 3-D simulations of respective converging acoustic energy beams transmitted from a multi-element transducer having uniform-shaped elements is shown in FIGS. 11A , 12 A, 13 A, 14 A and 15 A, and images generated by 3-D simulations of respective converging acoustic energy beams transmitted from a multi-element transducer having irregular shaped elements are shown in corresponding FIGS. 11B , 12 B, 13 B, 14 B and 15 B). Each of the pictures represents an acoustic pressure field obtained by the respective transducer array at the same conditions. Each field was obtained by phasing the transducer to obtain a maximum power at the desired focus position measure in x, y, x distances from the transducer array.
[0039] FIGS. 11A and 11B are the respective acoustic pressure fields at the x, y, z coordinates of 0, 0, 30 mm (i.e., taken along the z-axis with zero electronic steering). As can be observed, the pressure fields are very similar, with the field in 11 B (from the irregular shaped elements) being a slightly “reduced amplitude” version of the field generated by the uniform-shaped elements shown in FIG. 11A . FIGS. 12A and 12B show the respective x-y cross-section of the fields shown in FIGS. 11A and 11B , for z=25 mm. FIGS. 13A and 13B are the respective acoustic pressure fields at the x, y, z coordinates of 11 mm, 0, 30 mm, i.e., with an electronic steering angle out of the x-pane of 20.1°. As can be seen, the field generated by the uniform-shaped elements ( FIG. 13A ) has a significant hot spot reduction formed at 20.1° (−11 mm, 0, 30 mm) in the x-plane. FIGS. 14A and 14B show the respective x-y cross-sections of the fields shown in FIGS. 13A and 13B , for z=23 mm.
[0040] FIGS. 15A and 15B are taken at respective x-y cross-sections (for z=21 mm) of acoustic pressure energy fields having x, y, z coordinates of 11 mm, 11 mm, 30 mm, i.e., with an out-of-plane steering angle of 27.4° in both the x and y directions. As can be seen in FIG. 15A , electronic steering to this focal zone using a conventional, uniform-shaped transducer array results in hot spots at each of the “mirror-image” locations, i.e., at coordinates (−11 mm, 11 mm, 30 mm), (11 mm, −11 mm, 30 mm), and (−11 mm, −11 mm, 30 mm). On the other hand, as can be seen in FIG. 15B , by using a transducer array having irregular shaped elements, there are no distinct hot spots such as seen in FIG. 15A , even though there is an energy increase throughout the cross-sectional plane.
[0041] In some embodiments, before the respective transducer array is activated to deliver treatment-level ultrasound energy, an acoustic wave simulation can be performed to determine if any hot spots will be generated. For example, a computer model of the transducer may be created to model the configuration (e.g., shape, size, and relative position) of the transducer elements. Various operational parameters (such as operation frequencies, amplitudes, and operation phases for the respective transducer elements) can then be applied to the computer model to determine if a hot spot will result from a certain operational condition. As will be appreciated by those skilled in the art, while all transducer elements of an array may be activated in some instances, e.g., in order to maximize an amount of energy delivered to a steered-to focal zone, in other instances, sufficient therapeutic energy may be delivered without activating all elements of the array. Also, while the above embodiments have been described with reference to creating a single focal zone, in other embodiments, the same or similar methods can be used to create a plurality of simultaneous focal zones, thereby allowing simultaneous treatment of multiple target tissue regions.
[0042] Thus, although particular embodiments of the invention have been shown and described, it should be understood that the above discussion is not intended to limit the invention to these illustrated and described embodiments, which are provided for purposes of example only. Instead, the invention is defined and limited only in accordance with the following claims.
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An ultrasound transducer comprises a multiplicity of piezoelectric transducer elements attached to a backing layer and forming a two-dimensional array, the transducer elements each comprising one or more piezoelectric members that collectively form an energy transmitting surface of the respective transducer element, the energy transmitting surface having a geometric center, wherein the respective transducer element geometric centers are in an irregular formation.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to provisional U.S. patent application entitled “Nitriding Potential Control,” filed Nov. 7, 2014, having Ser. No. 62/076,916, the disclosure of which is hereby incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The disclosure relates generally to a method for nitriding steel and the nitrided steel obtained thereby, and more particularly, to a method for rapid nitriding of steel by controlling nitriding conditions such as nitriding temperature, nitriding time and nitriding potential.
BACKGROUND
[0003] Steels containing nitride forming elements such as Al, Cr, Mo, V, and Ti can be hardened by nitriding. For example, commercially available low alloy steels containing Cr and Mo are usually nitrided to increase the surface hardness where the surface hardness after nitriding is a function of the amount of the nitride forming elements in the steels and the nitriding conditions.
[0004] Nitriding is a thermo-chemical process by which the surface of a steel part is enriched with nitrogen to form alloy nitrides which improve the wear resistance, which also forms a surface nitride layer which can improve the corrosion resistance of the steel part. For example, nitriding increases surface hardness, wear resistance, resistance to certain types of corrosion, and compressive surface stresses, which improve the fatigue resistance of the steel part. Accordingly, nitrided steel articles are often used for gears, couplings, shafts, and other applications that require resistance to wear due to high stress loading and abrasive environments.
[0005] Gas nitriding is a common method of nitriding. The gas nitriding process generally includes heating steel parts, which have been heat-treated and finish-machined, to a temperature of about 510-540° C. and subjecting them into an atmosphere of nitrogenous medium such as ammonia gas. During gas nitriding, the nitrogen potential of the atmosphere is generally kept higher than the solubility of nitrogen in the steel parts. If the nitriding reaction is permitted to proceed uncontrolled, iron nitrides begin to form at the surface due to the buildup of nitrogen. Resultantly, if permitted, the iron nitride compound layer, called white layer, is formed on the surface of the steel parts, and the nitrogen coming from the atmosphere is required to pass through the white layer and thus diffuses into the base metal at a much slower rate.
[0006] The white layer is generally brittle and can spall under certain conditions, resulting in part and system failure. After nitriding, the white layer can be removed by mechanical grinding or chemical dissolution, but this requires additional cost and results in longer and inefficient manufacturing process cycles.
[0007] There have been efforts to control white layer formation on a surface of steel during the nitriding process. An example of controlling white layer formation on a surface of steel is disclosed in UK Pat. No. 1,303,428 (hereafter “the '428 patent”), entitled “Improved Process For Nitriding Iron Alloys.” The '428 patent is directed to subjecting an iron alloy at a temperature range favoring formation of Guinier-Preston (G.P.) zones but inhibiting forming iron nitrides. However, the process in the '428 patent takes a long time to complete the nitriding process to obtain a desired nitrided steel and is not energy- or operationally efficient. Therefore, it is not practical to apply the process in the '428 patent in a streamlined manufacturing process.
[0008] There is therefore a need for a process that can control white layer formation during nitriding steel and provide the desired nitrogen additions to the steel in an efficient time and energy management manner.
BRIEF SUMMARY
[0009] In one aspect, the disclosure is directed to a method for nitriding steel, the method including: placing the steel in a furnace having an atmosphere comprising partially dissociated ammonia gas; heating the steel to a highest temperature in a range of 400 to 600° C. while holding a nitriding potential below 15 atm −1/2 during heat-up from 400° C. up to the highest temperature; and holding the steel at the highest temperature while continuing to maintain the nitriding potential below 15 atm −1/2 , where a total time taken for the heating and holding the steel in the range of 400 to 600° C. during the nitriding is 15 hours or less, and where a composition of the steel comprises at least one of the group consisting of Al, Cr, Mo, V, and Ti.
[0010] In various aspect, the method further includes heating the steel to the highest temperature in the range of 400 to 600° C. while maintaining the nitriding potential below 15 atm −1/2 during the heat-up from 400° C. up to the highest temperature; and subsequently holding the steel for 5 hours or less, possibly 3 hours or less at or below the highest temperature in the range of 400 to 600° C. and at a nitriding potential in a range of from 0.5 to 10 atm −1/2 followed by the remainder of the time up to 15 hrs in total using a nitriding potential of 2 atm −1/2 or less.
[0011] In another aspect, the method further includes determining Nitriding Intensity, NI, for the nitriding, NI=a (αTn-725) ×c[(βK n ) d −bβK n ] where: NI is dimensionless; Kn is a nitriding potential, atm −1/2 ; a is a temperature impact constant, Tn is a temperature in Kelvin; α is a unit conversion constant for temperature, 1/K°; c is a nitriding impact multiplier, β is a unit conversion factor in atm 1/2 ; d is a nitriding impact constant and b is a nitrogen potential constant, where the temperature impact constant, the nitriding impact multiplier, the nitriding impact constant, and the nitrogen potential constant are a function of an alloy composition of the steel.
[0012] In another aspect, the method further includes heating the steel to the highest temperature in the range of 400 to 600° C. while maintaining the NI in a range of from 1 to 100 during heat-up from 400° C. up to the highest temperature; and subsequently holding the steel at or below the highest temperature in the range of 400 to 600° C. for 5 hours or less, possibly 3 hours or less, and at a NI in a range of from 1 to 50 followed by the remainder of the time up to 15 hrs in total using a NI in a range of from 1 to 20.
[0013] In another aspect, a nitrided steel obtained by the foregoing methods has an alloy composition including: by weight, C: from 0.1 to 2.2%; Mn: from 0 to 1.2%; Al: from 0 to 1.5%; Cr: from 0 to 5.5%; Mo: from 0.15 to 1.8%; Si: from 0 to 1.8%; V: from 0 to 1.2%; and Iron and acceptable trace elements: remaining balance where the nitrided steel maintains a hardness value of 57 HRC or higher in a region from a surface to a thickness of 75 μm or more of the steel, and possibly where the nitrided steel maintains a hardness value that is 35 HRC or higher in a region from a surface to a thickness of 250 μm or more for steels with core hardness of 32 HRC or lower.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 shows NI (Nitriding Intensity) plots as a function of nitriding time in hrs for various processes.
[0015] FIG. 2 shows the nitriding time in hrs, and nitriding temperature, T n , in ° C. corresponding to each of the NI plots, (1), (2), (3), (4), and (5) in FIG. 1 .
[0016] FIG. 3 shows the nitriding time in hrs, and nitriding potential, K n in atm −1/2 corresponding to each of the NI plots, (1), (2), (3), (4), and (5) in FIG. 1 .
[0017] FIG. 4 shows a microstructure obtained from a sample alloy steel by a traditional NI process (2).
[0018] FIG. 5 shows a microstructure of a sample alloy steel obtained by a WLF (White Layer Free) NI process (3) according to the disclosure.
[0019] FIG. 6 shows a microstructure of a sample alloy steel obtained by a TGP (Thin γ′ Phase) NI process (5) according to the disclosure.
[0020] FIG. 7 shows hardness plots obtained from the sample alloy steel obtained by a WLF NI process and the sample alloy steel obtained by a TGP NI process.
DETAILED DESCRIPTION
[0021] During a nitriding process, ammonia gas may be partially cracked in a separate reaction chamber and the resulting mixture of gases (NH 3 , N 2 , and H 2 ) may be fed into the nitriding furnace. Alternatively, decomposition of ammonia may be controlled by adjusting the turnover time of gases in the nitriding furnace itself. A check on nitrogen potential of the atmosphere may be accomplished by analyzing the exit gases.
[0022] During nitriding, the nitrogen may diffuse into the steel surface and react with iron, forming γ′ iron nitride (Fe 4 N), containing up to 6 wt % N. With increasing nitrogen the ε-phase (Fe 2-3 N) may be formed, which can absorb up to 11 wt % N. Therefore, when the nitrogen potential of the atmosphere exceeds the solubility limit in iron, iron nitrides (γ′ —Fe 4 N and/or ε-Fe 2-3 N) may form on the surface of the steel.
[0023] Commercial nitriding in a dissociated ammonia atmosphere is normally carried out at high nitrogen potentials where an iron nitride layer (“white layer”) is formed on the surface of the steel. Depending on the alloy and nitriding condition, various other phases and nitrides can form. For example, the percentage of γ′ and ε-nitrides in the white layer may depend on the carbon content of the steel where a higher carbon content may promote the formation of ε-nitride whereas a lower carbon content may form more γ′ iron nitride.
[0024] Below the white layer is the diffusion zone containing nitrogen in solid solution. In addition, the diffusion zone may contain stable metal nitrides formed by the various alloying elements of the steel, such as aluminum, molybdenum, chromium, and titanium. The thickness of the white layer and the thickness of the diffusion zone may depend on various parameters such as nitriding time, nitriding temperature, nitriding potential, and steel composition.
[0025] The gas nitriding process parameters may include nitriding temperature, nitriding time and nitriding potential in the atmosphere. The gas nitriding may involve heating an alloy to be nitrided in an atmosphere of dissociated ammonia gas. Ammonia gas itself is unstable at nitriding temperatures and dissociates on clean iron surfaces according to the reaction:
[0000] NH 3 →[N]+3/2H 2 Eq. (1)
[0000] where [N] represents nitrogen which is dissolved on the steel surface. A dissociation rate may represent the percentage of ammonia dissociated into hydrogen and nitrogen based on Eq. (1).
[0026] The nitriding potential (K n ) in atm −1/2 may be determined by
[0000]
K
n
=
P
NH
3
P
H
2
3
/
2
Eq
.
(
2
)
[0000] where P NH 3 and P H 2 are the partial pressures of the ammonia and hydrogen gases respectively.
[0027] A white layer can be beneficial for increased wear and corrosion resistance if the adherence and susceptibility of cracking of the nitrided layer is appropriately controlled. However, an excessively thick, brittle, non-adherent superficial white layer formed on the steel surface can be detrimental to the performance of the steel part. Therefore, it is necessary to adequately control the nitriding process so that white layer formation can be controlled or minimized as desired.
[0028] In one method, a mixture of ammonia and additive gas is employed. A nitriding potential (K n ) control process includes proper selection of atmosphere and adjustment of nitriding potential (K n ) in this method.
[0029] In one embodiment according to the disclosure, a nitriding condition may be determined by Nitriding Intensity, NI, that is a function of nitriding temperature and nitriding potential as follows.
[0000] NI= f (T n )× f (K n ) Eq. (3)
[0000] where: f (T n ) is a nitriding temperature factor having the likelihood of forming a white layer where T n represents a temperature throughout the nitriding process, including heat-up; and f (K n ) is a nitriding potential factor having the likelihood of forming a white layer where K n is nitriding potential.
[0030] In a particular implementation, the nitriding intensity, NI, may be determined by the following equation,
[0000] NI= a (αTn-725) ×c [(βK n ) d −b βK n ] Eq. (4)
[0000] where: NI is dimensionless; Kn is a nitriding potential; Tn is a temperature in Kelvin (K), a is a temperature impact constant, α is a unit conversion constant for temperature, 1/K°; c is a nitriding impact multiplier, β is a unit conversion factor in atm 1/2 ; d is a nitriding impact constant and b is a nitrogen potential constant.
[0031] As described in equations (3) and (4), the Nitriding Intensity may standardize the nitriding condition having the nitriding temperature, T n and the nitriding potential, K n . With the nitriding intensity, NI, a desired nitriding condition such as nitriding time, t, nitriding temperature, T n and nitriding potential, K n may be determined. In one aspect, the temperature impact constant, the nitriding impact multiplier, the nitriding impact constant and the nitrogen potential constant may be a function of the alloy composition of a steel. In some aspects, the temperature impact constant, the nitriding impact multiplier, the nitriding impact constant and the nitrogen potential constant may be adjusted such that, for the steel under consideration, the Nitriding Intensity value of 1 corresponds to a minimum detectable limit of nitriding and a Nitriding Intensity value of 100 corresponds to the level at which a white layer forms within 15 minutes of the nitriding.
[0032] According to Eq. (4) where: a is 1.0105; a is 1/K; c is 3; β is 1 atm 1/2 ; b is 0.05; and d is 0.92, FIG. 1 shows NI plots as a function of nitriding time for various processes for AISI 4140 steel. A nominal composition of the AISI 4140 steel is shown in Table 1 below.
[0000] TABLE 1 by weight C 0.37-0.44% Mn 0.65-1.10% Si 0.15-0.35% Cr 0.75-1.20% Mo 0.15-0.40% Iron and Balance acceptable trace elements
The NI plot (1) represents a Floe process having a two-stage nitriding condition, and the NI plot (2) represents a single-stage nitriding process. The NI plot (3) is an exemplary NI plot according to the disclosure where a maximum NI value in the NI plot (3) is much lower than those of the NI plots, (1) and (2). A steel part may have a white layer free surface after being nitrided according to the NI plot (3). The NI plot (4) is a typical controlled process. The NI plot (5) is another exemplary NI plot according to the disclosure to produce a thin γ′ phase layer on a steel surface. In one aspect, a maximum NI value during a full cycle of nitriding according to the disclosure may be 100 or less.
[0033] FIG. 2 shows the nitriding time in hrs, and nitriding temperature, T n , in ° C. corresponding to each of the NI plots, (1), (2), (3), (4), and (5) in FIG. 1 . The typical two stage nitriding cycle of (1) begins with a nitrogen purge, followed by heating either in nitrogen or ammonia. Once the sample is at a nitriding temperature, a set flow of ammonia, and sometimes nitrogen, is introduced to drive the nitriding potential to a moderately high level. The purpose of this first stage is to quickly build a thick white layer. After the white layer is built, a second stage, with a lower nitriding potential, is performed, often at a higher temperature. The purpose of this stage is to use the nitrogen in the white layer to drive diffusion into the steel. This type of two stage processes usually take 20-40+ hours to the completion of nitriding as shown in FIG. 2 .
[0034] The typical single stage nitriding cycle (2) in FIG. 2 begins with a nitrogen purge, followed by heating either in nitrogen or ammonia. Once the sample is at a nitriding temperature, a set flow of ammonia, nitrogen, and sometimes dissociated ammonia is introduced. The temperature is maintained until the desired depth of nitriding is achieved. The typical nitriding cycle (2) can have an event which prevents rapid nitriding, where high levels of ammonia during heat-up rapidly forms white layer, preventing rapid nitriding, where too much time with an elevated nitride potential during the cycle allows the free nitrogen to consume all of the available nitride forming elements, leading to the formation of iron nitrides at the surface (white layer), and/or where nitride potential is too low to drive rapid nitriding.
[0035] Compared to the processes of (1) and (2) as shown in FIG. 1 , the exemplary processes (3) and (5) according to the disclosure have a duration of nitriding much shorter than those of the processes (1) and (2), which gives rise to rapid nitriding, where a time taken from the commencement of nitriding to the completion may be in a range of from 3 to 15 hrs. In one aspect, the duration of nitrding at a temperature of 500° C. or above may be 15 hrs or less. In some aspects, the duration of nitrding at a temperature of 500° C. or above may be 12 hrs or less. In various aspects, the duration of nitrding at a temperature of 500° C. or above may be 5 hrs or less.
[0036] FIG. 3 shows the nitriding time in hrs and nitriding potential, K n (atm −1/2 ) corresponding to each of the NI plots, (1), (2), (3), (4), and (5) in FIG. 1 . Compared to the processes of (1) and (4), the exemplary processes (3) and (5) according to the disclosure have the applied nitriding potential at 15 atm −1/2 or less during the full cycle of nitriding process. Nitriding according to the disclosure can take place at more than one nitriding potential, but the maximum nitriding potential may be carefully controlled during the heat-up process to minimize and/or prevent the formation of white layer. The duration of nitriding may be 15 hours or less. In one aspect, the duration of nitriding at a nitriding potential applied at 1 atm −1/2 or above may be 15 hours or less. In some aspects, the duration of nitriding at a nitriding potential applied at 6 atm −1/2 or above may be 5 hours or less.
[0037] FIG. 4 shows a microstructure obtained from a sample alloy steel by a traditional NI process (2) where a thickness of a white layer formed on the steel surface is about 10 μm or more. FIG. 5 shows a microstructure of a sample alloy steel obtained by a WLF (white layer free) NI process (3) according to the disclosure where the steel surface is white layer free after the nitriding. FIG. 6 show a microstructure of a sample alloy steel obtained by a TGP NI process (5) according to the disclosure where a TGP (thin γ′ phase) layer in a thickness of 5 μm or less has formed after the nitriding.
[0038] FIG. 7 shows a hardness profile in HRC of the exemplary samples in FIGS. 5 and 6 . As shown in FIG. 7 , the samples maintain 55 HRC or higher in a region from the surface to a depth of 100 μm or more. In addition, the samples maintain 30 HRC or higher in a region from the surface to a depth of 500 μm or more. In one aspect, an alloy nitrided according to the disclosure may achieve a hardness value of 50 HRC or higher in a region of from the surface to a depth of 30 μm or more after nitriding in 15 hours or less. In some aspects, an alloy nitrided according to the disclosure may have a white layer of 5 μm or less on a surface of the nitrided alloy without further mechanical or chemical removal of the white layer on the surface. In various aspects, an alloy nitrided according to the disclosure may have a white layer of 2 μm or less on the surface. In another aspect, an alloy nitrided according to the disclosure may have a white layer of 1 μm or less on the surface or a white layer free surface.
INDUSTRIAL APPLICABILITY
[0039] The disclosure may be applicable to any steel alloy system containing nitride forming elements such as Al, Cr, Mo, V, Ti or the like where control of forming a white layer on a steel alloy surface is desired. Specifically, the disclosure may include a process forming a white layer of 5 μm or less on the steel alloy surface after nitriding. In one aspect, the disclosure may utilize Nitriding Intensity to determine a nitriding condition in control of forming a white layer on a steel surface during nitriding.
[0040] A group of alloy steels suitable for nitriding according to the disclosure may include a nominal composition as shown in Table 2 below.
[0000]
TABLE 2
by weight
C
0.1-2.20%
Mn
0-1.20%
Al
0-1.50%
Ni
0-4.40%
Cr
0-5.50%
Mo
0-1.80%
Si
0-1.80%
V
0-1.20%
W
0-1.40%
Ti
0-0.05%
Cu
0-0.30%
Iron and
Balance
acceptable trace
elements
[0041] In one aspect, a more economical group of hardenable alloy steels for nitriding according to the disclosure may include AISI/SAE 4100 series alloy steel. In some aspects, chromium-molybdenum-aluminum alloy steels may provide desired high surface hardness and core hardness after nitriding according to the disclosure. A nominal composition of the chromium-molybdenum-aluminum alloy steels may include as follows.
[0000]
TABLE 3
by weight
C
0.1-0.43%
Mn
0.75-1.2%
Si
0.15-0.35%
Cr
0.8-1.2%
Mo
0.15-0.25%
Al
0.08-0.13%
V
0.05-0.1%
Iron and
Balance
acceptable trace
elements
[0042] Steels having the above compositions may be supplied as pipes, hot-rolled plate, rolled round bars, forgings, round bars, square bars, flat bars, plates or the likes. In one aspect, parts having the above compositions may be first forged, or rolled from billets, and be quenched and tempered, then machined and nitrided. Parts may be used for the production of internal combustion engines such as crankshafts, piston pins, cam timing gears, connecting rods and the like.
[0043] In some aspects, manufactured parts, such as shafts, couplings, and gears, having the above composition, may be initially formed to a desired shape by forging or rolling. The formed parts may be hardened by heating to a high temperature for a period of time and then quenched in a cooling medium. For example, for AISI/SAE 4100 series alloy steels, the formed parts may be hardened by heating to a temperature of 845° C. or higher for a period of one hour and then quenched in either water or oil to complete transformation of the ferrite and pearlite microstructure to martensite microstructure. After tempering to precipitate and agglomerate the carbide particles and thereby provide improved toughness, the manufactured parts may be machined to a desired final dimension and then nitrided.
[0044] Nitriding an alloy steel may be carried out in an atmosphere containing partially dissociated ammonia gas in a temperature range of 400 to 600° C. According to the disclosure, the duration of nitriding at an active nitriding temperature of 500° C. or above may be 15 hours or less. In one aspect, nitriding potential at 10 atm −1/2 or less may be applied in the temperature range of 400 to 600° C. during the full cycle of nitriding process. In some aspects, the duration of nitriding at the active nitriding potential applied during the full cycle of nitriding process may be 5 hours or less.
[0045] During the nitriding process, a mixture of ammonia and an additive gas may be controlled by a parameter known as nitriding potential, K n . Proper selection of nitriding condition and adjustment of nitriding potential may prevent excessive white layer from forming on a steel surface. According to one embodiment of the disclosure, a nitriding condition may be determined by Nitiring Intensity, NI, that is a function of nitriding temperature and nitriding potential according to Eq. (3) and Eq. (4). In one aspect, a maximum NI value during a full cycle of nitriding according to the disclosure may be 100 or less. An alloy nitrided according to the disclosure may achieve a hardness value of 30 HRC or higher from the surface to a depth of 500 μm or more.
[0046] It will be appreciated that the foregoing description provides examples of the disclosed system and technique. However, it is contemplated that other implementations of the disclosure may differ in detail from the foregoing examples. All references to the disclosure or examples thereof are intended to reference the particular example being discussed at that point and are not intended to imply any limitation as to the scope of the disclosure more generally. All language of distinction and disparagement with respect to certain features is intended to indicate a lack of preference for those features, but not to exclude such from the scope of the disclosure entirely unless otherwise indicated.
[0047] Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value is incorporated into the specification as if it were individually recited herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context.
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A disclosure is directed to a method for rapidly nitriding steel, the method including: placing the steel in a furnace having an atmosphere comprising partially dissociated ammonia gas; heating the steel to a highest temperature in a range of 400 to 600° C. while holding a nitriding potential below 15 atm −1/2 during heat-up from 400° C. up to the highest temperature; and holding the steel at the highest temperature while continuing to maintain the nitriding potential below 15 atm −1/2 , where a total time taken for the heating and holding the steel in the range of 400 to 600° C. during the nitriding is 15 hours or less, and where a composition of the steel comprises at least one of the group consisting of Al, Cr, Mo, V, and Ti.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of International Application PCT/DK00/00233 filed May 9, 2000, the content of which is expressly incorporated herein by reference thereto.
BACKGROUND ART
[0002] The invention relates to a peristaltic fluid pump having a suction side and a pumping side and of the kind that comprises a pump housing having a mainly arcuate support surface, a flexible tube extending along this surface, a rotor having two opposite rollers for during operation rolling over the flexible tube along an entrance section where the tube successively is compressed, a pumping section extending across an angle of an arc of less than 180°, and an exit section where the compression successively is ended, whereby both sections is having an idling zone, respectively, without pumping action and a pumping zone, respectively, with pumping action, means for during operation making the rotor rotate, that the arcuate support surface is constructed in such a way that the two opposite rollers do not operate in synchronous phase opposition during operation.
[0003] Such a peristaltic fluid pump is used among other things for hemodialysis of a patient with kidney insufficiency, the pump thus serving for pumping the patient's blood through a dialyzer.
[0004] Conventionally, a blood pump is arranged in such a way that both rollers can simultaneously be in pumping engagement with the flexible tube during operation. Thereby, the blood enclosed in the tube section between the rollers is subjected to a considerable positive pressure in relation to the wanted discharge pressure of the pump. When the leading roller is disengaged again from the tube, the positive pressure is relieved. The positive pressure and the compressive pulsations result in hemolysis of the red blood cells.
[0005] U.S. Pat. No. 3,787,148 discloses a peristaltic fluid pump having an arc-shaped bearing surface extending across a length of arc shorter than 180° and at the ends passing into symmetrically arranged, short ramps extending obliquely in towards the arc-shaped bearing surface. In the application, it is stated that one of the rollers thereby begins flattening the tube, at the same time as the other roller begins the opposite operation. However, this design is not able to prevent considerable positive pressure and compressive pulsations from being produced in the pumped fluid.
[0006] During fluid entrance into the entrance section, the rearmost roller successively displaces some of the fluid in the tube. The process corresponds to the process in a hydraulic pressure cylinder where a piston displaces fluid in a cylinder. The length of the entrance section will thereby correspond to the stroke of the piston.
[0007] However, the presence of the oblique ramps in the pump known from the above U.S. patent results in a short length of stroke with a quick displacement of the fluid under the roller. This quick displacement of fluid causes the creation of a compression wave in the tube.
[0008] The reverse process takes place in the exit section where the foremost roller quickly is pulled out of engagement with the tube and thereby leaves a space which just as quickly is filled with affluent fluid.
[0009] The oblique ramps thus add to the inclination of positive pressure and compressive pulsations being produced in the pumped fluid.
[0010] U.S. Pat. No. 3,787,148 is furthermore based on the condition that the process in the entrance section is outbalanced by the process operating in opposite directions in the exit section. That the fact is different in reality is due to the circumstance that the rearmost roller begins pressing in on a full tube while the foremost roller begins to disengage a flat tube and that the displaced fluid volume is increasing concurrently with the tube being compressed and decreasing concurrently with the compression being discontinued. When the foremost tube starts opening, there is furthermore a pressure difference over the opening corresponding to the difference between the feed pressure and the suction pressure. Such a pressure difference is not present at the simultaneous closing of the tube by the rearmost roller.
[0011] In this way, neither the conventional peristaltic pumps nor the pump known from U.S. Pat. No. 3,787,148 can function without considerable rises in pressure occurring in the fluid in a cyclically repetitive way.
[0012] U.S. Pat. No. 4,564,342 and U.S. Pat. No. 5,470,211 disclose other peristaltic pumps which both are arranged in such a way that the flexible tube is always fully occluded by one roller. Therefore these pumps are only able to operate with some compressive pulsations.
[0013] Thus, there is a need for new peristaltic pumps which avoid these problems, and the present invention now provides devices which satisfy this need.
SUMMARY OF THE INVENTION
[0014] The present invention provides a peristaltic fluid pump of the kind mentioned in the opening paragraph, that is arranged to pump a fluid with smaller pressure differences and compressive pulsations in the fluid than previously known. The pump also is arranged to be able to pump with a discharge pressure that is constant during an entire pump cycle.
[0015] These features and benefits are obtained in a peristaltic fluid pump having a suction side and a pumping side and which comprises: a pump housing having a mainly arcuate support surface, a flexible tube extending along the support surface, a rotor having two opposite rollers for during operation rolling over the flexible tube along an entrance section where the tube successively is compressed, a pumping section extending across an angle having an arc of less than 180°, an exit section where the compression successively is ended, and means for rotating the rotor during operation. Advantageously, the entrance and exit sections include an idling zone that does not provide a pumping action, and a pumping zone that does provide a pumping action. Also, the arcuate support surface is constructed in such a way that the two opposite rollers do not operate in synchronous phase opposition during operation, and the entrance section end and the exit section beginning are arranged at an angle that is smaller than 180°.
[0016] Preferably, the arcuate support surface is arranged in such a way that the rearmost roller enters into the pumping zone of the entrance section sufficiently to build up pressure between the rollers to a level which is the same as the pumping pressure, and the pumping zone of the exit section terminates at an angle of an arc (β) of more than 180° in relation to the pumping zone of the entrance section. It is beneficial for the arcuate support surface to extend along a curve such that fluid displacement during the passage of the rollers along the entrance and exit sections of the tube changes linearly during operation.
[0017] In one embodiment, the pump includes pressure means for elastically pressing against the tube outside of the engagement of the rollers to maintain the tube in a predetermined shape. Preferably, the pressure means comprises springs, such as disc springs, placed on opposite sides of the tube.
[0018] In other embodiments, the pump can include a device for affecting the tube with a spring power in the entrance section of the tube, or a device for affecting the tube with a spring power in a zone downstream of the exit section of the tube.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The invention will be explained in greater detail below, describing only exemplary embodiments with reference to the drawings, in which
[0020] [0020]FIG. 1 is a side elevational view of a peristaltic pump according to the invention with the front cover removed,
[0021] [0021]FIG. 2 is the peristaltic pump in FIG. 1 seen along the line II-II,
[0022] [0022]FIG. 3 is on a larger scale a fractional view of the pump in FIG. 2 but in a second pumping phase,
[0023] [0023]FIG. 4 is a fractional view of a roller which in a first pumping phase is rolling over the tube of the peristaltic pump,
[0024] [0024]FIG. 5 is the roller in FIG. 4 seen along the line V-V,
[0025] [0025]FIG. 6 is a fractional view of the roller in a second pumping phase,
[0026] [0026]FIG. 7 is the roller in FIG. 6 seen along the line VII-VII,
[0027] [0027]FIG. 8 is a fractional view of the roller in a third pumping phase,
[0028] [0028]FIG. 9 is the roller in FIG. 9 seen along the line IX-IX,
[0029] [0029]FIG. 10 is a diagrammatic view of the working cycles of the pump, and
[0030] [0030]FIG. 11 is a graphic display of the hemolysis that was produced by using a conventional blood pump and a blood pump according to the invention, respectively.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0031] The novel and unique features according to the invention, whereby this is achieved, is due to the fact that the angle between the ending of the entrance section and the beginning of the exit section is smaller than 180°. Thereby, it is possible to compensate for the difference between the processes in the two sections and a constant feed pressure is advantageously obtained without compressive pulses in the fluid before or behind the foremost roller.
[0032] As mentioned above, fluid is successively displaced in the tube while the rearmost roller passes the entrance section. At the same time, the roller is forming an ever greater impression in the tube. The impression acts as a piston that pushes the fluid in front of it during the pump stroke. The roller is thus passing over the tube at the same rate as the fluid is flowing in this tube.
[0033] At first, the impression in the tube is not large enough to be able to create any noticeable pressure difference between the front and back of the impression. The pressure is equalized continuously via the still relatively large gap under the impression in the tube. There is, therefore, no pumping action in and through a zone which in the following is called the idling zone of the entrance section.
[0034] At a certain time, the impression will be so large that a pressure equalization no longer can take place between its front and back via the now relatively narrow gap in the tube under the roller. From this moment, the roller starts pumping at a pressure that rises from zero to full feed pressure along a zone which in the following is called the pumping zone of the entrance section.
[0035] The pumping zone of the entrance section passes continuously into the actual pump section of the tube, said section is extending into the exit section of the tube, and just as the entrance section the exit section has a pumping zone and an idling zone but evidently placed in reverse order in relation to the rotating direction of the rotor.
[0036] The foremost roller begins its opening operation with suction pressure at the back and feed pressure at the front. The pressure difference is inclined to make the fluid flow in the opposite direction than the wanted. This disadvantage is remedied by arranging the pump in such a way that the rearmost roller has reached so far into its pumping zone that it can equalize the above pressure difference before the foremost roller begins its opening operation.
[0037] The pressure equalization can expediently take place by arranging the end of the entrance and the beginning of the exit at an angle that is smaller than 180°.
[0038] Furthermore, the angle between the beginning of the entrance and the end of the pump section can advantageously be larger than 180°. Thereby, it is ensured that the foremost roller has time to draw the excess fluid from the successive compression of the tube by the rearmost roller with it during the passing of the pump section without significant rise in pressure on the suction side.
[0039] In order to avoid unwanted compressive pulsations when the fluid is pumped, both entrance and exit can be designed with a relatively great length to ensure the pump a long stroke and thereby a smooth and steady running.
[0040] The arcuate support surface can furthermore be extending in such a way that the fluid displacement increases and decreases respectively linearly during the passing of the entrance and exit section. This further ensures against compressive pulses being produced when the pump is operating.
[0041] The tube will usually be made of a suitable plastic. However, plastic is often deformed permanently when it repeatedly is subjected to heavy deformations. Thereby, the tube will gradually become more flat. Having this form, the volumetric displacement of the tube is not the same as before. The effective capacity of the pump will therefore gradually decline during use.
[0042] In order to avoid this unwanted effect the pump can be provided with pressure means for pressing against the sides of the tube and thereby forcibly keeping the tube in shape so that it outside the areas of engagement with the rollers always will contain the same quantity of fluid per unit length. This means that the volumetric displacement and the capacity of the pump always will be constant values.
[0043] The enforced shape of the tube can, for example, be an oval with a major axis perpendicular to the rotational axis of the rotor. When said pressure means furthermore are arranged in such a way that they are pressing elastically against the sides of the tube, the tube will serve as a buffer for absorbing possible compressive pulses in the fluid.
[0044] The pressure means can be any resilient member that applies force to the tube. In a simple and effective embodiment, two disc springs are disposed on opposite sides of the tube.
[0045] The pump can furthermore comprise a device, e.g. a spring, for affecting the tube with a spring force in the entrance section of the tube. This device acts as a kind of safety valve for preventing the pressure in the tube in exceeding a predetermined limit in the entrance phase of the rearmost roller.
[0046] The spring force of the spring can advantageously be adjustable so that the discharge pressure of the pump can be adapted to dialyzers with different flow resistance. Thereby the pump can be made to pump with the same output irrespective of the individual flow resistance of the current dialyzer.
[0047] The pump can furthermore comprise a device, e.g. a spring, for affecting the tube with a spring force in a zone downstream of the exit section of the tube. This device acts as a kind of non-return valve which reduces or prevents the tendency of the fluid running in the opposite direction than that which is desired.
[0048] The pump according to the invention can advantageously be used in many places, such as in industry for pumping corrosive fluids, or for pumping drinks, such as milk which has to meet a high hygienic standard.
[0049] The pump can also with great advantage be used as heart pump or for pumping a patient's blood through a dialyzer. The following description illustrates a preferred embodiment where the pump is a blood pump of the latter kind.
[0050] The main components of the blood pump in FIGS. 1 and 2 is a pump housing 1 , a rotor 2 and a flexible tube 3 .
[0051] Inside the housing 1 is constructed an arcuate support surface 4 for supporting the tube 3 . At the front, the housing is closed with a front cover 5 and at the back with a back cover 6 provided with a bearing 7 .
[0052] The rotor 2 is by means of a rotor shaft 8 flyingly journaled in a bearing 7 of the back cover. On the part of the shaft that is inside the housing, two parallel rotor arms 9 are mounted at a mutual distance. Equidistantly from the shaft 8 , a roller 10 ′ and 10 ″ is rotatably journaled at the ends of each of these rotor arms 9 .
[0053] The part of the rotor shaft 8 that is extending out of the housing 1 is by means of a coupling 11 connected to a motor 12 for rotating the rotor during operation.
[0054] On the rotor shaft are furthermore mounted two disc springs 13 which are kept at a mutual distance by a spacer pipe 14 and locked on the shaft 8 by means of locking rings 15 .
[0055] In each disc spring are constructed a number of radially extending cuts 16 for providing the desired spring characteristic, and furthermore two other cuts 17 for making room for the rollers.
[0056] During operation, the rotor is rotating anticlockwise as indicated with the arrow. At the entrance end of the rollers, the tube is supported by a spring 18 while the second spring 19 is pressing against the tube at the exit end.
[0057] As shown in FIGS. 4 - 9 , the tube is during the entrance of the roller successively flattened to a pump configuration in which the roller is pumping blood through the tube. At the exit end the same process is taking place but in reverse order.
[0058] If a positive pressure and compressive pulsations are produced in the pumped blood, it can result in hemolysis of the red blood cells.
[0059] The spring 18 at the entrance end of the tube acts as a safety valve for preventing such a positive pressure in the tube. For this purpose, the spring 18 is arranged in such a way that it yields if the pressure in the tube exceeds a predetermined quantity.
[0060] As for the spring 19 , it acts as a non-return valve for preventing backflow when the foremost roller begins its disengagement with the tube. The spring 19 is arranged in such a way that it more or less compresses the tube in case of drop of pressure. Thereby, a possible backflow is checked or prevented.
[0061] As can be seen best in FIG. 3, the disc springs 13 are pressing the tube oval. Thereby, its cross-sectional area is reduced in relation to a full, round tube so that the oval tube during the entrance of the rearmost roller can receive extra blood without any significant rise in pressure as the disc springs during this merely yield and allow the tube to assume its initial round shape.
[0062] The disc springs can for example be made of plain spring steel having a small friction factor in relation to the tube material. If desired, the springs can be Teflon-coated on the side facing the tube to reduce friction. Alternatively, the disc springs can be made of a plastic material such as Teflon. The cuts 16 in the disc springs serve for providing the springs with the necessary flexibility.
[0063] The embodiments of the springs 18 , 19 and the disc springs 13 that are shown and described are only to be taken as examples as they within the scope of the invention can have any expedient design.
[0064] The disc springs 13 can thus be replaced by elastically deformable, curved strips made of a suitable resilient or cellular rubber. The strips elastically exert a pressure on the sides of the flexible tube and are during operation compressed simultaneously with tube during the passing of the rollers.
[0065] In the dialysis treatment, it is desirable that the dialyzer be adapted to the individual needs of the patient. The blood pump according to the invention is therefore likely to be used for dialyzers with different flow resistance. If the capacity of the blood pump still is to be kept at a fixed value, its discharge pressure must therefore be able to be adjusted in dependence of the flow resistance in the current dialyzer.
[0066] This adjustment advantageously takes place by means of an adjusting screw 22 for adjusting the value of the spring power of the spring. The screw 22 is as shown screwed into a nut 23 on a bent end 24 of the spring 19 . On the opposite side the screw is provided with an adjustment knob 25 with a pointer 26 for indicating the current value of the spring power on a scale not shown.
[0067] FIGS. 4 - 9 illustrate how the entrance of a roller takes place. The exit takes place in reverse order.
[0068] In FIGS. 4 and 5 the roller 10 preliminarily touches the tube 3 . There is no pumping action. The pumping action does not begin until the roller has compressed the tube sufficiently. It is assumed that this is the case in FIGS. 6 and 7.
[0069] In FIGS. 8 and 9 a full pumping action is obtained. It is in this connection mentioned that the blood pump can function effectively even if the tube is not fully compressed. In some cases, it is however preferred to pump with the tube being completely compressed.
[0070] [0070]FIG. 10 diagrammatically illustrates the working cycles of the blood pump. The circular cycle described by the rollers is shown by dash-dot line 20 . The arcuate support surface 4 is shown in full line, and the pressure produced by the respective roller during its passing is shown by light line 21 . The rollers are illustrated by the shown arrows while the different pumping phases are indicated by the letters a-g. The rotor is rotating anticlockwise in the direction indicated by the arrow.
[0071] A roller begins its engagement with the flexible tube at point a in the position shown in FIGS. 4 and 5 and is in the same position disengaged at point g. The total stroke of the roller is thus the distance a-g.
[0072] At first, the tube is compressed so little that there is no pumping action. At b it is assumed that the situation in FIGS. 6 and 7 has taken place. The pumping action begins. At d the situation in FIGS. 8 and 9 has been reached. There is now full pumping action.
[0073] During the continuous rotation of the rotor there is now pumped at full power until the point e has been reached. Here the roller begins to open the tube. At f the situation in FIG. 7 has taken place again. The pumping action has ended. From f-g the roller gradually disengages the tube further but without pumping action. In g the roller only just touches the tube. From g-a the roller does not touch the tube.
[0074] The stroke a-g is thus divided into an entrance section a-d, a full pumping section d-e and an exit section e-g.
[0075] The entrance section a-d is further divided into an idling zone a-b and a pumping zone bd, whereas the exit section e-g is divided into a pumping zone e-f and an idling zone f-g.
[0076] At e the foremost roller in some of the conventional blood pumps opens the tube with a feed pressure at the front and a suction pressure at the back. The pressure difference between these two pressures causes the blood to start flowing in the opposite direction of the wanted direction, that is clockwise in stead of counter-clockwise.
[0077] The working cycles of the blood pump are therefore according to the invention arranged in such a way that the diametrically opposite rearmost roller at c has entered so far into the pumping zone of the entrance section b-d that the roller has been able to built up the pressure between the foremost and rearmost roller to the same level as the pumping pressure.
[0078] Thereby backflow is prevented, and it is furthermore advantageously obtained that the blood pump will be pumping with constant discharge pressure.
[0079] A condition for obtaining this effect is that the angle α between the ending d of the entrance section and the beginning e of the exit section is smaller than 180°.
[0080] A second condition consists in the ending f on the pumping zone of the exit section being displaced an angle of an arc β of more than 180° in relation to the beginning b of the pumping zone in the entrance section.
[0081] It is important that the roller during the entrance is compressing the tube calmly and slowly so that harmful compressive impulses are avoided, and it is obviously just as important that the roller is disengaged again slowly and calmly from its engagement with the tube.
[0082] The entrance section a-d and the exit section e-g are therefore both extending across a length of arc χ;δ of between 130° and 30°, preferably between 110° and 50°, and especially between 100° and 70°.
[0083] In order to further ensure effectively against compressive impulses being produced in the pumped blood, the entrance section a-d and the exit section e-g, respectively are constructed in such a way that the displaced amount of blood is changed linearly during the passing of the rollers of each of these sections.
[0084] [0084]FIG. 11 is a graphic display of the hemolysis that was produced by using a conventional blood pump and a blood pump according to the invention, respectively.
[0085] The test was in both cases carried out with the following:
Blood volume: 200 ml Pumping rate: 300 ml/min Na-heparin added: 70 ie/ml
[0086] If hemolysis can be measured as change in amount of potassium, it is due to the fact that the red blood cells have a very high potassium content which at hemolysis (bursting of the cell membranes of the blood cells) are released to the blood plasma (serum) and thereby can be measured as an increasing potassium content.
[0087] As can be seen the hemolysis is decreased drastically when a blood pump according to the invention is used instead of a conventional blood pump.
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A peristaltic fluid pump having a suction side and a pumping side. The pump includes a pump housing having a mainly arcuate support surface, a flexible tube extending along this surface, a rotor having two opposite rollers for during operation rolling over the flexible tube along an entrance section where the tube is successively compressed, a pumping section extending across an angle of an arc of less than 180°, and an exit section where the compression successively ends, and a motor for during operation making the rotor rotate. The arcuate support surface is shaped in such a way that the rearmost and foremost rollers do not operate in synchronous phase opposition during their passage of the entrance and exit section. The peristaltic fluid pump is capable of pumping a fluid with less pressure difference and compressive pulsations in the fluid than previously known, making it especially suitable for pumping a patient's blood through a dialyzer.
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TECHNICAL FIELD
The present invention relates to 3-(2,2,2-trimethylhydrazinium)propionate salts of the general formula X − (CH 3 ) 3 N + NHCH 2 CH 2 COOH where X − is an acid anion selected from the group of acid phosphate, acid fumarate, acid oxalate, acid maleate and/or acid pamoate, orotate, galactarate, sulfate, dichloroacetate, acid galactarate, fumarate, taurate, maleate, acid aspartate, creatinate, acid sulfate, magnesium succinate, acid citrate, citrate, succinate, acid succinate, adipinate, acid tartrate and lactate, which distinguish from 3-(2,2,2-trimethylhydrazinium) propionate dihydrate by low hygroscopicity and/or increased thermal stability and/or lasting action. This invention relates also to the method of such salt preparation and to pharmaceutical formulations containing the said salts.
BACKGROUND OF THE INVENTION
3-(2,2,2-Trimethylhydrazinium) propionate is disclosed in U.S. Pat. No. 4,481,218.
It is well known that 3-(2,2,2-trimethylhydrazinium) propionate as dihydrate (this substance being known under its International Nonproprietary Name of Meldonium) is widely used for controlling carnitine and gamma-butyrobetaine concentration ratio and consequently the speed of fatty acid beta-oxidation in the body (Dambrova M., Liepinsh E., Kalvinsh I. Mildronate: cardioprotective action through carnitine-lowering effect. Review.//Trends Cardiovasc. Med.-2002.-Vol. 12, N.6. -P. 275–279. Rupp H., Zarain-Herzberg A., Maisch B. The use of partial fatty acid oxidation inhibitors for metabolic therapy of angina pectoris and heart failure//Herz, 2002-Vol. 27, N.7.-P. 621–636. Mildronate, Met-88. Drugs Fut. 2001, 26(1), p. 82).
Due to these properties, Meldonium (registered with the trade mark of “MILDRONĀTS®”, “MILDRONATE®”, “M POHAT®”) is extensively applied in medicine as an anti-ischemic un stress-protective drug in treating various cardio-vascular diseases and other pathologies involving tissue ischemia (R. S. Karpov, O. A. Koshelskaya, A. V. Vrublevsky, A. A. Sokolov, A. T. Teplyakov, I. Skarda, V. Dzerve, D. Klintsare; A. Vitols, I. Kalvinsh, L. Matveyeva, D. Urbane. Clinical efficacy and safety of Mildronate in patients with ischemic heart disease and chronic heart failure. Kardiologiya, 2000, Vol. 6, -P. 69–74.)
However, Meldonium as dihydrate has essential drawbacks, the first of which consists in its rather high hygroscopicity. Already after 24 hours maintenance at 100% air humidity, Meldonium mass is increased by 10% because of water absorption, the substance being transformed into a syrup.
Other essential drawback of Meldonium is caused by the half-elimination period equalling 4–10 hours for humans while this drug must be used 2–4 times daily in the clinic (V. Dzērve. Mildronāts. PAS “Grindeks”, 1999, p. 1), though it is longer in trials on rats (K. Yoshisue, Y. Yamomoto, K. Yoshida, M. Saeki, Y. Minami, Y. Esumi, Y. Kawaguchi. Pharmacokinetics and biological fate of 3-(2,2,2-trimethylhydrazinium)propionate (MET-88), a novel cardioprotective agent, in rats. Drug Metabolism and Disposition, vol. 28, No 6, 687–694).
As Meldonium dihydrate is unsuitable for single daily oral introduction, it was one of the aims of the present invention to find other pharmacologically acceptable Meldonium forms which would be applicable for single daily use. It is generally known that amino acid betaine salts usually have good solubility in water. If pharmacologically acceptable acids are selected, resorption and elimination pharmacokinetics and biological activity of these salts normally does not much differ from the parameters of the initial compound.
Besides, Meldonium is not very stable: while heated, it fast loses the water of the crystal hydrate. In turn, the anhydrous form of Meldonium is unstable and extremely hygroscopic. In such form, this compound soon becomes coloured and gets a specific annoying odour. Thus, the hygroscopicity and thermal non-stability of Meldonium dihydrate are significant disadvantages restricting the possibilities of preparing different oral and external drug dosage forms from this compound. Furthermore, Meldonium dihydrate is actively dehydrated at temperatures so low as 40–45° C. This means that sure storage of Meldonium dosage forms containing crystal hydrate is rather embarrassing in countries with hot climate.
Because Meldonium dihydrate is not readily applicable for producing drug oral dosage forms, it was a further object of this invention to find other pharmacologically acceptable salts of Meldonium which would lack hygroscopicity or/and, be thermally stable and could be stored in any climatic zone for a long time.
DETAILED DESCRIPTION OF THE INVENTION
For most Meldonium salts, their pharmacokinetic properties practically do not differ from those described for Meldonium. Therefore the use of these salts for preparing pharmaceutical compositions seemingly have no advantage as compared to Meldonium.
To our surprise, we suddenly found that Meldonium salts of some pharmaceutically acceptable polybasic acids are an exception in this respect; although readily soluble in water, they essentially differ from Meldonium by their pharmacokinetic and pharmacodynamic properties.
It was an astonishing discovery since no theoretical argument exists why Meldonium salts, which are easily soluble in water should have resorption and elimination speed different from that of Meldonium.
Nevertheless, we succeeded in finding among the above salts some specific Meldonium salts with appropriate pharmacokinetics and pharmacodynamics allowing their single daily use; they are: X − (CH 3 ) 3 N + NHCH 2 CH 2 COOH where X − is the anion of acids is selected from the group of mono-substituted fumaric acid, mono-substituted phosphoric acid, mono-substituted oxalic acid, mono-substituted maleic acid un mono- and/or di-substituted galactaric, pamoic acids and orotic acid.
It is common knowledge that betaines of amino acids are commonly relatively stable substances. It is well known that these compounds are readily soluble in water and the biological activity of their pharmacologically acceptable salts usually does not differ from that of the initial compound.
However, Meldonium and monobasic, dibasic as well as tribasic pharmaceutically acceptable acid salts have equal or even higher hygroscopicity than Meldonium itself. Moreover, many of them cannot be prepared in crystalline form at all because they form syrups containing variable quantity of water.
The salts of both strong and weak acids, viz. Meldonium sulfate, hydrogen chloride, acetate, lactate, citrate as well as salts of many other pharmaceutically acceptable acids are hygroscopic. Consequently, using these salts for preparation of pharmaceutical compositions for oral use is deemed lacking preference to that of Meldonium.
We noticed completely unexpectedly that Meldonium salts of some pharmaceutically acceptable polybasic acids are exceptional in this regard; they proved to be practically non-hygroscopic though easily soluble in water. We observed that these compounds are also very stable while maintained at both room temperature and temperatures up to at least 50 centigrade over a long period of time. Similarly we gained the unanticipitated result that such specific monobasic acid as orotic acid forms a non-hygroscopic Meldonium salt, too. All of the claimed salts proved more stable thermally than Meldonium.
Orally administered Meldonium is easily bioavailable also from these salts, therefore these salts are much more suitable for preparing various drug dosage forms than the hygroscopic and thermally unstable Meldonium. It was an astounding discovery because no theoretical underpinning suggests any difference of Meldonium orotate or polybasic acid salts, which are also readily soluble in water, from other salts as to hygroscopicity.
Since they are not hygroscopic and/or have increased thermal stability, these salts can be easily handled and are favourably suitable for manufacturing solid administration forms. Their aqueous solutions are less acid than those of the corresponding chlorides: consequently these salts are also more suitable for manufacturing injectable administration forms.
The following non-limiting examples illustrate the preparation of salts according to the present invention.
EXAMPLE 1
The following methods may be applied for the preparation of these salts. Meldonium is dissolved in water or other appropriate solvent, an equimolar quantity of a polybasic acid selected from the group of fumaric acid, phosphoric acid, aspartic acid, citric acid, lactic acid, maleic acid, oxalic acid, or orotic acid (the latter is taken in semi-molar quantity) is added, and the mixture is stirred at temperature from 20 to 50° C. till the corresponding salt is formed. At the second technological stage, Meldonium salts are evaporated to dryness if necessary. At the third technological stage, in case of need the obtained salts are recrystallised from a suitable solvent.
EXAMPLE 2
The said salts can also be prepared from the corresponding salts of Meldonium production intermediates, viz. methyl- or ethyl-esters of 3(2,2,2,-trimethylhydrazinium) propionate, the latter being heated together with the corresponding acids in aqueous or aqueous-alcoholic solutions, and subsequent treatment, eduction and purification being performed by analogy with the first method of preparation.
EXAMPLE 3
Method of salt preparation from meldonium dihydrate. Meldonium and the corresponding acid are dissolved in a small quantity of water at 40–50° C. under stirring. The obtained solution is evaporated in vacuum at 40–50° C. Acetone or acetonitrile is added to the formed mass (what predominantly is viscous syrup), and the mixture is grated. The precipitated crystalline mass is stirred in acetone or acetonitrile during several hours, filtered off, washed with acetone or acetonitrile, dried in vacuum at room temperature.
Sample hygroscopicity was tested by H 2 O content determination before the test and after 24 hours maintenance at 100% humidity (keeping in a closed vessel over water). On such conditions, Meldonium absorbs 10% water (as to mass increase) during 24 hours. Water content was determined by titration by Fischer's method; in cases of syrup formation water content is determined by sample mass increase.
The claimed invention is illustrated by, but not restricted to the following examples of salts obtained by the above method:
EXAMPLE 4
Meldonium orotate (1:1). Mp. 211–214° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.56 (2H, t, CH 2 COO − ); 3.29 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ); 6.18 (1H, s, —CH═). Found, %: C, 43.78; H, 6.01; N, 18.48. Calculated, %: C, 43.71; H, 6.00; N, 18.53. Initially H 2 O content in the sample was 0.3919%; during 24 hours at 100% humidity it remains unchanged.
EXAMPLE 5
Meldonium phosphate (1:1). Mp. 158–160° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.60 (2H, t, CH 2 COO − ); 3.31 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ). Found, %: C, 29.64; H, 7.05; N, 11.33 Calculated, %: C, 29.51; H, 7.02; N, 11.47. Initially H 2 O content in the sample was 0.0762%; during 24 hours at 100% humidity it remains unchanged.
EXAMPLE 6
Meldonium fumarate (1:1). Mp. 140–142° C. 1 H NMR spectrum, δ, ppm: 2.57 (2H, t, CH 2 ); 3.29 (2H, t, CH 2 ); 3.35 (9H, s, Me 3 N + ); 6.72 (2H, s, —CH═CH—). Found, %: C, 45.46; H, 6.94; N, 10.72. Calculated, %: C, 45.80, H, 6.92; N, 10.68. Initially H 2 O content in the sample was 0.18%; during 24 hours at 100% humidity it remains unchanged.
EXAMPLE 7
Meldonium oxalate (1:1). Mp. 123–125° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.61 (2H, t, CH 2 COO − ); 3.30 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ). Found, %: C, 40.86; H, 6.82; N, 11.78 Calculated, %: C, 40.68; H, 6.83; N, 11.86. Initially H 2 O content in the sample was 0.1661%; after 24 hours maintenance at 100% humidity it was 3.1211%.
EXAMPLE 8
Meldoniuma maleate (1:1). Mp. 98–100° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.60 (2H, t, CH 2 COO − ); 3.31 (2H, t, NCH 2 ); 3.35 (9H, s, Me 3 N + ); 6.35 (2H, s, —CH═CH—). Found, %: C, 45.93; H, 6.95; N, 10.65. Computational, %: C, 45.80; H, 6.92; N, 10.68. Initially H 2 O content in the sample was 0.387%; after 24 hours maintenance at 100% humidity it was 4.6844%.
EXAMPLE 9
Meldonium mucate (galactarate; 2:1; ×H 2 O). Mp. 152–154° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.46 (4H, t, 2×CH 2 COO − ); 3.26 (4H, t, 2×NCH 2 ); 3.35 (18H, s, 2×Me 3 N + ); 3.98 un 4.31—two singlets of low intensity, protons of mucic acid. Found, %: C, 42.13; H, 7.58; N, 10.77. Calculated, %: C, 41.53; H, 7.75; N, 10.76. Initially H 2 O content in the sample was 3.0414%; after 24 hours maintenance at 100% humidity it was 7.6830%.
EXAMPLE 10
Meldonium pamoate (1:1; ×H 2 O). Meldonium (5.46 g, 30 mmol) and pamoic acid (5.82 g, 15 mmol) are mixed with water and acetone (15+15 ml), the formed suspension is evaporated, 30–40 ml toluene is added to the residual viscous mass, it is grated, and evaporation is repeated. If the residue is insufficiently dry, treatment with toluene is repeated. Mp. 128–133° C. (decomp.). 1 H NMR spectrum (DMSO-d 6 ), δ, ppm: 2.41 (2H, t, CH 2 COO − ); 3.14 (2H, t, CH 2 N); 3.25 (9H, s, Me 3 N + ); 4.75 (2H, s, —CH 2 — (pam.) ); 7.12 (2H, t, H arom ); 7.26 (2H, td, H arom ); 7.77 (2H, d, H arom ); 8.18 (2H, s, H arom ); 8.35 (2H, s, H arom ). Found, %: C, 62.90; H, 5.83; N, 4.98. Calculated, %: C, 63.07; H, 5.84; N, 5.07. Initially H 2 O content in the sample was 1.71%; after 24 hours maintenance at 100% humidity sample mass increased by 9% due to absorbed water.
EXAMPLE 11
Meldonium sulfate (2:1). T m 80–182° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.60 (4H, t, 2×CH 2 COO − ); 3.30 (4H, t, 2×CH 2 N); 3.35 (18H, s, 2×Me 3 N + ). Found, %: C, 37.08; H, 7.73, N, 14.29; S, 8.20. Calculated, %: C, 36.91; H, 7.74; N, 14.35; S, 8.21. Initially H 2 O content in the sample was 0.313%; after 24 hours maintenance at 100% humidity sample mass increased by 11.8% due to absorbed water.
EXAMPLE 12
Meldonium dichloroacetate (1:1). Mp. 86–88° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.61 (2H, t, CH 2 COO − ); 3.31 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ); 6.05 (1H, s, —CHCl 2 ). Found, %: C, 35.13; H, 5.85; N, 10.10. Calculated, %: C, 34.92; H, 5.86; N, 10.18. Initially H 2 O content in the sample was 1.17%; after 24 hours maintenance at 100% humidity sample mass increased by 12% due to absorbed water.
EXAMPLE 13
Meldonium mucate (galactarate; 1:1). Mp. 152–154° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.47 (2H, t, CH 2 COO − ); 3.26 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ); 3.71 and 3.98—two singlets of low intensity, protons of the slightly soluble mucic acid. Found, %: C, 40.22; H, 6.75; N, 7.75%. Calculated, %: C, 40.22; H, 6.79; N, 7.86. Initially H 2 O content in the sample was 1.98%; after 24 hours maintenance at 100% humidity it was 12.8%.
EXAMPLE 14
Meldonium fumarate (2:1). Mp. 156–158° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.53 (4H, t, 2×CH 2(meld) ); 3.29 (4H, t, 2×CH 2(meld) ); 3.35 (18H, s, 2×Me 3 N + ); 6.65 (2H, s, —CH═CH— (fum.ac.) ). Found, %: C, 46.68; H, 7.91; N, 13.69. Calculated, %: C, 47.05; H, 7.90; N, 13.72. Initially H 2 O content in the sample was 1.5136%; after 24 hours maintenance at 100% humidity it was 13.4707%.
EXAMPLE 15
Meldonium 2-aminoethane sulfonate (taurate; 1:1; ×1.5H 2 O). Mp. 190–193° C. (with decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.38 (2H, t, CH 2 COO − ); 3.18–3.30 (4H, m, NCH 2(meld.) +CH 2(taur.) ); 3.34 (9H, s, Me 3 N + ); 3.42 (2H, t, CH 2(taur.) ). Found %: C, 32.40; H, 8.16; N, 13.98; S, 10.60. Calculated, %: C, 32.21; H, 8.11; N, 14.08; S, 10.75. Initially H 2 O content in the sample was 9,4824%; after 24 hours maintenance at 100% humidity it was 17.0854%.
EXAMPLE 16
Meldonium maleate (2:1). Mp. 104–106° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.54 (4H, t, CH 2 COO − ); 3.30 (4H, t, CH 2 N); 3.35 (18H, s, Me 3 N + ); 6.42 (2H, s, —CH═CH—). Found, %: C, 46.59; H, 7.88; N, 13.50. Calculated: C, 47.05; H, 7.90; N, 13.72. Initially H 2 O content in the sample was 1.3595%; after 24 hours maintenance at 100% humidity sample mass increased by 18% due to absorbed water.
EXAMPLE 17
Meldonium L-(+)-aspartate (1:1; ×2H 2 O). Mp. 146–148° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.49 (2H, t, CH 2 COO − ); 2.70–2.99 (2H, m, CH 2(asp.) ) 3.27 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ); 3.95 (1H, dd, CHNH 2 ). Found, %: C, 37.71; H, 7.85; N, 13.03. Calculated, %: C, 38.09; H, 7.99; N, 13.33. Initially H 2 O content in the sample was 12.5%; after 24 hours maintenance at 100% humidity sample mass increased by 18% due to absorbed water.
EXAMPLE 18
Meldonium creatinate (1:1; ×3H 2 O). Mp. 227–228° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.38 (2H, t, CH 2 COO − ); 3.03 (3H, s, NMe (creatine) ); 3.22 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ); 3.92 (2H, s, NCH 2(creatine) ). Initially H 2 O content in the sample was 15.8%; after 24 hours maintenance at 100% humidity sample mass increased by 18% due to absorbed water.
EXAMPLE 19
Meldonium sulfate (1:1). T m 98–100° C. 1 H NMR spectrum (D 2 O), δ, ppm: 2.62 (2H, t, CH 2 COO − ); 3.31 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ). Found, % C: C, 29.23; H, 6.57; N, 11.17; S, 13.10. Calculated: C, 29.50; H, 6.60; N, 11.47; S, 13.13. Initially H 2 O content in the sample was 1.4189%; after 24 hours maintenance at 100% humidity sample mass increased by 20% due to absorbed water.
EXAMPLE 20
Meldonium magnesium succinate (1:1:1; ×2H 2 O). (see Meldonium-magnesium tartrate). Mp. 135–140° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.39 (2H, t, CH 2 COO − ); 2.46 (4H, s, —CH 2 —CH 2 — (succin.ac,) ); 3.22 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ). Found, %: C, 36.66; H, 7.28; N, 8.37. Calculated: C, 37.23; H, 6.87; N, 8.68. Initially H 2 O content in the sample was 10.1215%; after 24 hours maintenance at 100% humidity sample mass increased by 20% due to absorbed water.
EXAMPLE 21
Meldonium magnesium citrate (1:1:1; ×2H 2 O) (see Meldonium-magnesium tartrate). Mp. 195–200° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.48 (2H, t, CH 2 COO − ); 2.75 (4H, dd, 2×CH 2(citr.) ); 3.26 (2H, t, CH 2 N); 3.34 (9H, s, Me 3 N + ). Found, %: C, 36.58; H, 6.09; N, 6.96. Calculated: C, 36.34; H, 6.10; N, 7.06. Initially H 2 O content in the sample was 9.45%; after 24 hours maintenance at 100% humidity the sample diffused.
EXAMPLE 22
Meldonium citrate (1:1). Mp. 90–95° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.56 (2H, t, CH 2 COO − ); 2.85 (4H, dd, 2×CH 2(citr.) ); 3.28 (2H, t, CH 2 N); 3.35 (9H, s, Me 3 N + ).
EXAMPLE 23
Meldonium citrate (2:1). Mp. 101–107° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.51 (4H, t, 2×CH 2 COO − ); 2.81 (4H, dd, 2×CH 2(Citr.) ); 3.26 (4H, t, 2×CH 2 N); 3.35 (18H, s, 2×Me 3 N + ).
EXAMPLE 24
Meldonium succinate (1:1). Mp. 95–100° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.51 (2H, t, CH 2(meldon.) ); 2.60 (4H, s, —CH 2 —CH 2 — (succin.ac.) ); 3.27 (2H, t, CH 2(meldon.) ); 3.35 (9H, s, Me 3 N + ).
EXAMPLE 25
Meldonium succinate (2:1). Mp. 103–107° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.47 (4H, t, 2×CH 2(meldon.) ); 2.59 (4H, s, —CH 2 —CH 2 — (succin.ac.) ); 3.29 (4H, t, 2×CH 2(meldon.) ); 3.35 (18H, s, 2×Me 3 N − ).).
EXAMPLE 26
Meldonium adipinate (2:1). Mp. 110–114° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 1.55–1.70 (4H, m, 2×CH 2(adip.) ); 2.28–2.39 (4H, m, 2×CH 2(adip.) ); 2.45 (4H, t, 2×CH 2(meldon.) ); 3.24 (4H, t, 2×CH 2(meldon.) ); 3.34 (18H, s, 2×Me 3 N + ).
EXAMPLE 27
Meldonium tartrate (1:1). Mp. 100–107° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 2.57 (2H, t, CH 2 COO − ); 3.29 (2H, t, CH 2(meldon.) ); 3.35 (9H, s, Me 3 N + ); 4.55 (2H, s, CH (tart.ac.) ).
EXAMPLE 28
Meldonium lactate (1:1). Mp. 110–114° C. (decomp.). 1 H NMR spectrum (D 2 O), δ, ppm: 1.33–1.48 (3H, m, Me (lac.ac,) ); 2.50 (2H, t, CH 2 COO − ); 3.26 (2H, t, CH 2(mildr.) ); 3.35 (9H, s, Me 3 N + ); 4.21 (1H, q, CH (lac.ac.) ).
This invention relates also to pharmaceutical formulations containing at least one of the Meldonium salts described herein as pharmaceutical active and pharmaceutically acceptable solid or liquid excipients used in drug dosage form production. Solid formulations suitable for producing dosage forms of oral introduction as well as syrups and solutions containing the claimed salts and excipients are preferable.
In case when the active substance(s) is (are) inserted into tablets, caplets, pills, granules, powders, or capsules, they shall contain a Meldonium salt from 0,5 to 5 gr. per tablet, caplet, pill, capsule or one portion of powder or granules.
The following non-limiting examples illustrate the pharmaceutical formulation of salts for solid formulation
EXAMPLE 29
Formulation for Manufacturing Tablets
A Meldonium salt according to the invention
500
mg
Starch
20
mg
Talc
10
mg
Ca-stearate
1
mg
Total
531
mg
The following non-limiting examples illustrate composition suitable for producing capsules is the following:
EXAMPLE 30
A Meldonium salt according to the invention
500
mg
Starch
66
mg
Talc
26
mg
Ca-stearate
3
mg
Total
602
mg
In case if the active(s) are introduced by injections or orally by means of drops, a syrup or beverage, the pharmaceutical formulation shall contain a Meldonium salt according to this invention in a ratio of 0,5 to 60% by weight and a pharmaceutically admissible solvent, e.g. distilled water, an isotonic, glucose or buffer solution or mixtures of them.
The following non-limiting examples illustrate the pharmaceutical formulation of salts for injectable administration or/and orally administration:
EXAMPLE 31
Injection Formulation:
A Meldonium salt according to the invention
500
mg
Water for injections
5
ml
EXAMPLE 32
A Syrup Formulation:
A Meldonium salt according to the invention
25.00
mg
Methyl-p-hydroxybenzoate
0.20–0.60
g
Propyl-p-hydroxybenzoate
0.01–0.1
g
Propylene glycol
6.15–8.30
g
Sorbit
120.00–150.50
g
Glycerine
10.00–15.00
g
Purified water
108
ml
Total
250
ml
In case of trans-dermal application of the active(s), it's (their) content in an cream, gel, solution, ointment or plaster shall be 0.5–40% by weight.
The following non-limiting examples illustrate the pharmaceutical formulation of salts for trans-dermal (local/topical) administration:
EXAMPLE 33
Gel Formulation:
A Meldonium salt according to the invention 10.00% Sodium starch glycollate type C, 4.00 Propylene glycol 2.00 Fumaric acid 0.40 Purified vater 83.40
In the case the salt are administered rectally their content in a suppository or microenema accounts for 0.5 to 40% by weight.
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New salts of Meldonium, the method of their preparation, and pharmaceutical formulation on their basis have been described. The general formula of these salts is X − (CH3)3N+NHCH2CH2COOH where X − is an acid anion selected from the group of pharmaceutically acceptable acids. Practically non-hygroscopic and/or increased thermal stability and/or lasting action Meldonium hydrogen salts of fumaric acid, phosphoric acid, oxalic acid, maleic acid, and pamoic acid as well as Meldonium orotate and galactarate are especially suitable. Novel pharmaceutical formulations containing non-hygroscopic and/or increased thermal stability and/or and/or lasting action 3-(2,2,2-trimethylhydrazinium) propionate salts for oral parenteral, rectal, and transdermal introduction are concurrently described.
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FIELD OF THE INVENTION
[0001] The present invention relates to a protective device. It is particularly concerned with protection of the femur head, the iliac crest, the lower lumbar region, the coccyx, and the sacrum of the person using the device.
BACKGROUND OF THE INVENTION
[0002] Hip fractures are a health problem of enormous proportion. Approximately 250,000 hip fractures occur annually in the United States, resulting in an estimated annual cost of over seven billion dollars in medical and nursing services. In the United States, the average cost of a hip fracture for all age groups in 1984 was $29,800.
[0003] Over 98% of hip fractures are caused by falls. Growing evidence suggests that the strongest determinant of hip fracture risk in the event of a fall is the kinematical state of the body at the moment of impact. A simple fall from a standing height has several times the potential energy required to fracture a healthy hip.
[0004] In order for a fall from a standing height to cause a hip fracture, four conditions must be met: (1) The subject must be oriented to land on the hip; (2) Protective responses must be inadequate to reduce the energy of the fall below the critical threshold; (3) Local shock absorbers such as fat and muscles around the hip must be inadequate to reduce the energy of the fall below the critical threshold; and (4) Bone strength in the proximal femur must be insufficient to resist the residual energy of the fall that is transmitted to the hip.
[0005] Due to the inevitability of the first condition and the immutability of the fourth condition, previous protective devices have focused on the second and third conditions. These devices seek to prevent injuries to the lower lumbar, hip and pelvis regions through the use of various padding agents such as gel or closed-cell foam.
[0006] Previous devices have utilized thick pads that are placed inside pockets of a garment. The pockets often shift positions in relation to the user's body causing discomfort, poor protection, and restriction of movement. Other devices use belts or connecting members to hold pads in place with the same problematic results.
[0007] The problem with these devices is that they are bulky, expensive, and limited in mobility, generally targeting geriatric patients. In today's active society falling occurs in all ages and genders and across a wide range of traditional and new “extreme” sports such as in-line skating, skiing, skateboarding, field hockey, extreme Frisbee, basketball, ice skating, mountain biking, gymnastics, volleyball, etc.
BRIEF SUMMARY OF THE INVENTION
[0008] The present invention provides an inexpensive, disposable, lightweight and easy-to-use device that appeals to all ages and genders. The present invention relates to a device for protecting various areas of a user's body. It is particularly concerned with a device for protecting the hipbones, femur, lower lumbar region of the spine, coccyx, and sacrum through the use of self-adhesive pads.
[0009] The key to the present invention is the lightweight, self-adhesive pads that make up the device. In order for protective devices to appeal to all users and not just older users, the devices must be lightweight, easily fitted, cost-effective and non-bulky with ample freedom of movement.
[0010] The present invention allows pads to be precisely placed in a manner consistent with the user's bodily dimensions as the pads may adhere directly to the skin or garments of the user. Because the pads adhere to the location of primary placement, the pads will not shift position during use, thus increasing the likelihood of adequate protection and appeal to all users.
[0011] Young users also express distaste for devices that must be stepped into, such as a protective pair of shorts. The present invention eliminates that problem by allowing users to simply press the pads into position.
[0012] In one embodiment, the present invention uses extremely lightweight pads comprised of low-density polyethylene (LDPE) and high-density polyethylene (HDPE) held together by a means such as pre-wrap, soft foam, or any suitable adhesive. The LDPE and HDPE layers contain air bubbles and/or air-filled tubules. When a user impacts with the ground or perhaps an opponent, the air bubbles rupture, thus dispersing the impact force and signaling that the pad has outlived its usefulness and should be replaced.
[0013] Unlike foam or gel pads, the “air bubble” pads' lightweight nature allows users to increase protection without sacrificing speed and ease of movement.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] The present invention will be better understood by reading the Detailed Description of the Preferred and Alternate Embodiments with reference to the accompanying drawing figures, in which like reference numerals denote similar structure and refer to like elements throughout, and in which:
[0015] FIG. 1 is a side view of an embodiment of the device.
[0016] FIG. 2 is a rear view of an embodiment of the device.
[0017] FIG. 3 is a cross-sectional view of a pad in one embodiment of the device
DETAILED DESCRIPTION OF THE INVENTION
[0018] In describing the preferred and alternate embodiments of the present invention, as illustrated in the figures and/or described herein, specific terminology is employed for the sake of clarity. The invention, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish similar functions.
[0019] Referring now to FIG. 1 , the present invention in a preferred embodiment uses five pads 11 , 12 , 13 and a mesh netting 14 for connecting the pads. In the preferred embodiment, two hip pads 12 substantially cover the iliac crest, anterior superior iliac spine, and posterior superior iliac spine. Two femur head pads 13 substantially cover the greater trichinae region. The rear pad 11 covers the lower lumbar spinal process, the transverse processes of the sacrum, and the upper area of the coccyx. The pads are connected to each other by the mesh netting 14 .
[0020] FIG. 3 shows the general composition of the pads 11 , 12 , 13 . The first layer 31 is the inner layer that faces the body of the user. The first layer 31 is an adhesive such as Kinesio-Tex tape for securing the pad to the user's body or clothes. Although the preferred embodiment uses Kinesio-Tex tape, any substance capable of adhering to the user's body or clothes may be used. In the preferred embodiment, the second layer 32 is a thin, foam sheet made out of polyethylene. The mesh netting 14 is connected to the foam. Although the preferred embodiment uses a polyethylene second layer 32 , any suitable substance such as polystyrene or Cushion-Lite™ may be used.
[0021] In the preferred embodiment, the third layer 33 is a sheet of low-density polyethylene having small bubbles 41 dispersed inside the polyethylene such that the layer 33 is similar to everyday “bubble wrap.” The small bubbles function to absorb the shock of an impact upon the user. Although the preferred embodiment uses low-density polyethylene for the third layer 33 , any suitable substance such as polystyrene, high-density polyethylene, or blends thereof may be used. And although the preferred embodiment uses bubbles filled with ambient air, the bubbles could be filled by any substance capable of absorbing shock such as gel, or pressurized air.
[0022] In the preferred embodiment, the fourth layer 34 is a sheet of high-density polyethylene having larger bubbles 42 relative to the third layer 33 dispersed inside the polyethylene such that the layer 34 is similar to everyday “bubble wrap.” Although the preferred embodiment uses high-density polyethylene for the fourth layer 34 , any suitable substance such as polystyrene, low-density polyethylene, Air Cushion™ or blends thereof may be used.
[0023] In the case of the rear pad 11 and the hip pads 12 , the fourth layer 34 also has convoluted, air-filled tubules 43 for providing protection against the forces of impact upon a user. In the case of the femur head pads 13 , the fourth layer has at least one concentric, air-filled tubule that is placed over the femur head for dispersing the force of an impact upon a user. Although the convoluted tubules and the concentric tubules in the preferred embodiment are filled with ambient air, any suitable substance such as gel or pressurized air may be used.
[0024] In the preferred embodiment the rear pad 11 extends vertically upward from the upper end of the coccyx to the lower lumbar spinal process. The rear pad 11 extends horizontally to substantially protect the transverse processes of the sacrum. Convoluted tubules 43 are placed along the periphery of the pad and air bubbles 42 fill the space between the periphery of the convoluted tubules 43 .
[0025] In the preferred embodiment the hip pads 12 extend horizontally around the user's waist so as to substantially cover the iliac crest, anterior superior iliac spine, and posterior superior iliac spine. Convoluted tubules 43 horizontally extend along the length of the pads 12 . Air bubbles 42 are dispersed around and between the convoluted tubules 43 . Although the preferred embodiment shows two convoluted tubules being used, the number may vary as needed.
[0026] In the preferred embodiment the femur head pads 13 have a “keyhole” shape. The upper portion of the pad is circular with a rectangular depending lower portion. Concentric tubules 44 are placed in the center of the upper, circular portion of the pad 13 in a “bullseye” array. Air bubbles 42 are placed along the periphery of the pad and surrounding the “bullseye.” The number of concentric tubules 44 used in the “bullseye” array can be varied, two being the preferred number in this embodiment.
[0027] In the preferred embodiment, the five pads 11 , 12 , 13 are connected to each other by a mesh netting 14 . The mesh netting allows a user to carry the pads around as a single device. Although the preferred embodiment includes all five pads, the mesh netting may be easily cut, allowing the user to utilize only those pads he/she needs to. In fact, the mesh netting need not be used at all as its main purpose is simply to hold the pads together for carrying purposes.
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A self adhesive protective padding device having a plurality of pads able to be adhered precisely to the hip and lower back areas of the body, wherein the padding being light weight and disposable, consisting of multi-layer air-filled material, is designed to protect the body from hip and bone fracture due to falls.
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CROSS REFERENCE TO RELATED APPLICATION
This application claims priority to the prior filed U.S. provisional application having Application Number 61095553, filed on Sep. 9, 2008.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
The invention described herein may be manufactured and used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereon or therefore.
FIELD OF THE INVENTION
The invention relates to step well quantum cascade (QC) structures for use in quantum cascade lasers (QCLs).
BACKGROUND OF THE INVENTION
Conventional quantum cascade lasers (QCLs) have used square (symmetric when not under an applied bias) quantum wells. At least in part because conventional QCLs use square quantum wells, it is not possible in conventional QCLs to place both the radiative and LO-phonon transitions within one single quantum well when the radiative transition energy spacing is smaller than the LO-phonon energy spacing (as can be for terahertz QCLs).
The first QCL was a mid infrared laser that used LO-phonon scattering for depopulation; however, the diagonal transitions that were used for both the phonon and radiative transitions are generally not well suited for terahertz applications (J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, Science, 264:553 (1994)).
Other conventional square four quantum well and three quantum well LO-phonon terahertz QCLs have been developed. They use at least two quantum wells for the radiative transition and a third quantum well which uses two energy levels; one energy level is used to resonantly tunnel the lower lasing state and the other arranges the lower state, approximately spaced at the LO-phonon energy. While these configurations can have vertical transitions, they use more than one quantum well for the radiative transition, and due to the use of resonant tunneling of the lower lasing state, the lower lasing state always has a doublet of states (for example, see quantum states E 4 and E 3 in FIG. 5 of U.S. Pat. No. 7,158,545 to Qing Hu, et al.). This doublet of states can provide a mechanism of absorption loss of terahertz radiation in the lower frequency of operation limit. (Q. Hu and B. S. Williams, “Terahertz Lasers and Amplifiers Based on Resonant Optical Phonon Scattering to Achieve Population Inversion,” U.S. Pat. No. 7,158,545, Filed Sep. 12, 2003, issued Jan. 2, 2007) (H. Lou, S. R. Laframboise, Z. R. Wasilewski, G. C. Aers, and H. C. Liu, Appl. Phys. Lett, 90, 04112 (2007)). Also, oscillator strengths typically range from ˜0.5 to less than 1.
Conventional LO-phonon QCL configurations can experience unwanted parasitic injection into the lower lasing state. Attempts to reduce that unwanted parasitic injection have been made by adding an additional well at the injector, but the oscillator strength was reduced with this type of approach (S. Kumar, B. S. Williams, J. L. Reno, Appl. Phys. Lett. 88:121123 (2006)).
Miniband approaches, such as the bound to continuum approach that features minibands and a somewhat isolated radiative state (G. Scalari, L. Ajili, J. Faist, H. Beere, E. Linfield, D. Ritchie, and G. Davies, Appl. Phys. Lett. 82:3165 (2003)) as well as hybrid miniband configurations with optical-phonon scattering (G. Scalari, N. Hoyler, M. Giovannini, and J. Faist, Appl. Phys. Lett. 86:181101 (2005)), have also been pursued. Oscillator strengths for miniband configurations are sometimes listed higher than their LO-phonon configuration counterparts; however, this is somewhat offset since their section lengths are about twice as long as compared to LO-phonon configurations. Miniband configurations can also be more susceptible to thermal back filling.
The importance of improving the injector efficiency can be seen by the following approximate 2D population inversion relation:
Δ n 2 D = η J e τ 2 ( 1 - τ 1 τ 21 ) - ( 1 - η ) J e τ 1
where η is the injection efficiency, e=1.602 176 53(14)×10 −19 Coul., J is the current density, Δn 2D is the 2D population inversion, and the state lifetimes are represented by τ. The population inversion can be improved by increasing the injection efficiency, having a long upper state lifetime, and by having τ 1 <<τ 21 .
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 of the drawings is a conduction band profile of one embodiment of a step well.
FIG. 2 of the drawings illustrates one embodiment of a step injector.
FIG. 3 of the drawings is a conduction band profile of two lasing sections of one embodiment of a step well quantum QC structure with each lasing section having a single well injector and a step having two equal height steps.
FIG. 4 of the drawings is a conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well (having a single step) and a single well injector.
FIG. 5 of the drawings is a conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well (having a single step) and a one well injector where the step well and injector well troughs are different heights.
FIG. 6 of the drawings is a conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well (having two different height steps) and a single well injector.
FIG. 7 of the drawings is a conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well (having a single step) and a two well injector.
FIG. 8 of the drawings is a conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well (having a single step) and a two well injector that allows resonant tunneling of the lower lasing state, and the lower state(s).
It is to be understood that the foregoing and the following description are exemplary and explanatory only and are not to be viewed as being restrictive of the invention, as claimed.
DESCRIPTION
Before beginning with the description of some of the embodiments, it is noted that, for illustrative purposes, a Type I bandgap alignment (where the barrier heights in the conduction band are controlled by the material bandgap) is assumed in this specification, including the claims, and drawings.
The term “quantum well” is known in the art. As used herein, consistently with the usage in the art, a “quantum well”, formed in the conduction band of a semiconductor construct, refers to a planar semiconductor region sandwiched between two planar semiconductor regions (typically referred to as barrier layers) having a different bandgap, where the bandgap of the sandwiched region is smaller than the bandgaps of the barrier layers (for square wells the barrier layers usually have the same bandgap). The spacing between the barrier layers, and consequently the thickness of the quantum well layer (the quantum well layer is the “sandwiched region”), is selected such that charge carriers residing in the quantum well layer exhibit quantum effects.
The term “step quantum well” (referred to in this specification including the claims as “step well”), formed in the conduction band of a semiconductor construct, as used herein, describes a planar semiconductor region, having at least two semiconductor layers sandwiched between two planar semiconductor regions (barrier layers), where: 1) each of the at least two semiconductor layers comprising the sandwiched semiconductor region having a bandgap that is different than the bandgap of at least one of the other at least two semiconductor layers in the sandwiched semiconductor region; and 2) each of the at least two semiconductor layers comprising the sandwiched region having a bandgap that is smaller than the bandgap of the barrier layers (which often have the same bandgap). Any sandwiched semiconductor layer having a bandgap greater than the bandgap of the sandwiched semiconductor layer having the smallest bandgap is considered to be a “step”.
A Quantum Cascade (QC) structure constructed in accordance with the principles of the invention includes an active lasing region generally formed as a semiconductor heterostructure having a plurality of cascaded nominally identical lasing sections, which are functionally associated in series. The number of the lasing sections is typically about 200 sections.
In some embodiments, the heterostructure of at least one lasing section of an embodiment of a terahertz QC structure includes at least one quantum well, where at least one of the at least one quantum wells is a step well capable of forming at least three states (upper, middle, and lower). Note that in some embodiments employing a step well injector, it is possible that less than three states are formed within the step well. The heterostructure of some embodiments of a terahertz QC structure has only one quantum well per lasing section when that one quantum well is a step well.
An exemplary embodiment of a step well in a QC structure is formed as an Al x Ga 1-x As heterostructure, where at least two Al compositions are used. However, in other embodiments, a step well in a QC structure is formed using more than two Al compositions, as shown in the embodiments of FIGS. 5 , 6 , and 8 . An Al x Ga 1-x As heterostructure is an exemplary material that may be used to grow the step well(s) in a QC structure. The step well(s) in a QC structure may also be grown using suitable semiconductor materials known to one skilled in the art other than Al x Ga 1-x As. The lasing sections are doped in the usual method; generally one of the barriers or wells is doped or center delta doped.
The active region may be formed into a waveguide by any known means. Two commonly used waveguide approaches are the metal-metal and surface-plasmon waveguides. The facets of the waveguide and resonator can be coated with a high reflectivity coating or left uncoated. The laser is formed by growing N sections and processing the sample into a waveguide/resonator. Typically, the active region thickness is on the order of about 10 μm and guide widths are on the order of about 50 to about 200 μm, depending on the type of waveguide used.
Considering the surface plasmon waveguide first, the side contacts spacing is generally set to about 50 nm to keep the mode from coupling to avoid higher waveguide loss. In order to have ohmic contacts, the top contact layers are generally doped (for example about 60 nm thick and doped at 5×10 18 cm −3 ). The optimal lower plasma layer thickness can be determined by computing the threshold gain=(α m +α w )Γ, where
α m =−1/2 ln( R 1 R 2 ) is the mirror loss, with R 1 and R 2 being the intensity reflectivity, (1)
α w is the waveguide loss,
Γ is the confinement factor,
as a function of plasma layer thickness for different doping concentrations and mirror losses (to corresponding resonator lengths).
For a metal-metal waveguide configuration, the top and lower contact layers can be doped to generate ohmic contacts, for example about 60 nm thick (10 and 50 nm layers doped at 5×10 19 and 5×10 18 cm −3 , and the lower contact may also use a LTG GaAs layer). For the metal-metal waveguides, the threshold gains are often less than the surface plasmon guides, with the confinement factors, Γ, is equal to about 1, but generally have lower output coupling factors
α m /(α m +α w )). (2)
Although the figures illustrate no more than two lasing sections, those having ordinary skill in the art will appreciate that the exemplary illustrations are applicable to other lasing sections in the active region. Further, though certain conduction band heights and energy states (or levels) are illustrated, the illustrated conduction band heights and energy levels were selected for exemplary purposes, and those having ordinary skill in the art will appreciate that the conduction band heights and energy levels of a step quantum well QC structure can vary in accordance with the principles of the invention.
FIG. 1 of the drawings illustrates an exemplary conduction band profile of one possible embodiment of part of a lasing section of a terahertz LO-phonon step well QC structure having a quantum well structure having only a single quantum well—the single quantum well being a step well. In FIG. 1 , three states, (E 0 (lower state), E 1 (‘middle state’ or ‘lower lasing state’), and E 2 (‘upper lasing state’)) are formed, (in the presence of an applied electric field), in which the energy spacing between E 2 and E 1 (which are spaced at the radiative energy spacing) is smaller than the energy spacing between E 1 and E 0 (which are spaced at or near the resonant LO-phonon energy spacing); the upper lasing state, E 2 , is located near or above the highest point 3 of the only (therefore the first) step 8 , and the lower lasing state, E 1 , is located below the upper lasing state, E 2 , and below the highest point 3 of the step 8 .
FIG. 2 of the drawings illustrates an exemplary embodiment of a step injector having a single conduction band height step; a step injector (as is illustrated as being located within a step well structure in FIGS. 3 , 4 , 5 , 6 , 7 , and 8 ) having multiple equal conduction band height steps and/or multiple different conduction band height steps can be used/constructed in accordance with the principles of the invention. For simplicity, a step injector having a single conduction band height step ( FIG. 2 ) is discussed. A step injector can be used in a QCL having a semiconductor heterostructure having a first lasing section (n) functionally coupled in series with a second lasing section (n+1), wherein each of the first lasing section (n) and second lasing sections (n+1) has a quantum well. A quantum well within each of the first and the second lasing sections is a step well. The step well has at least one step 8 . The step well has, in the presence of an applied electric field, an upper lasing state, E upper lasing state , and a lower lasing state, E lower lasing state . A previous lasing section's lower state is shown as E lower state ), wherein the upper lasing state, E upper lasing states is located near or above the highest point 3 of the first of the at least one step 8 , ( FIG. 2 illustrates a step injector having a step well having only a single conduction band height step 8 ; therefore, in FIG. 2 , the single step 8 is the first step), and the lower lasing state, E lower lasing state , is located below the upper lasing state, E upper lasing state , and below the highest point 3 of the first of the at least one step 8 ; the spatial separation of the wavefunctions of the upper lasing state, E upper lasing state lasing state, of the second lasing section and the lower state, E lower state , of the first lasing section is less than the spatial separation of the wavefunctions of the lower lasing state, E lower lasing state , of the second lasing section and the lower state, E lower state , of the first lasing section, n, such that the overlap of the wavefunctions of the upper lasing state E upper lasing states of the second lasing section, n+1, and the lower state, F lower state , of the first lasing section, n, is greater than the overlap of the wavefunctions of the lower lasing state, E upper lasing state , of the second lasing section, n+1, and the lower state, E upper lasing state , of the first lasing section, n.
FIG. 3 shows an exemplary conduction band profile of two lasing sections—n and n+1—of an exemplary N lasing section cascade with one lasing section n+1 outlined (where typically N 185 sections). This conduction band profile depicts the energy levels of the two adjacent lasing sections—n and n+1—upon application of an applied electric field. For example, the lasing section n, which has a step well 6 , with two equal conduction band height steps ( 8 , 10 ) (assuming using a Al x Ga 1-x As heterostructure), and a single well injector 12 , includes quantum energy states E 0 , E 1 , E 2 , and E 3 . E 0 and E 1 represent the lower states energy levels, and the wavefunction for this doublet of lower states is shown. E 2 represents the energy level of the lower lasing state, and the wavefunction for this state is shown. Note that in some embodiments of the invention the lower lasing state, E 2 , is arranged as a single energy state; in other words, it can be arranged without forming a doublet of states. E 3 , located near or above the highest point 3 of the first step 8 in the lasing section, represents the wavefunction of the upper lasing state. Likewise, the adjacent lasing section n+1 has a step well 6 , with two equal conduction band height steps ( 8 , 10 ) (assuming using a Al x Ga 1-x As heterostructure), and a single well injector 12 , and includes similar energy states, though shifted in energy due to the applied electric field. States E 4 and E 5 are principally not used states. Each energy state is characterized by a wavefunction whose modulus squared is indicative of the probability distribution of the electrons residing in that state. The conduction band profile can be found by solving Schrödinger's equation or by using a self consistent solution to Schrödinger's and Poisson's equations. FIG. 3 is shown under an applied electric field. Electrons are injected into the upper state, E 3 , and the optical or radiative transition occurs between states E 3 and E 2 . The LO-phonon assisted transition takes place from state E 2 to the lower state (doublet) E 1 and E 0 since E 21 is near ω LO . This ensures fast depopulation of state E 2 via LO-phonon scattering, with a scattering rate lifetime of about 0.5 psec. Mini-band scattering between the doublet lower state, E 1 and E 0 , takes place, with injection into the upper lasing state, E 3 , of the next adjacent section. For simplicity, to describe injection from one lasing section into another, we herein describe injection from lasing section n into lasing section n+1 as representative. A similar injection occurs in the remainder of the N lasing sections of the N lasing section step well QC structure. If we consider the injection of electrons from lasing section n into lasing section n+1, the step reduces unwanted injection into state E 2 of lasing section n+1 from the lower states E 1 and E 0 of lasing section n. Monte Carlo simulations, (taking into account electron-electron, LO-phonon, impurity, and interface roughness scattering), of these types of structures yields injection efficiencies of about 90% from the doublet states E 1 and E 0 of lasing section n to state E 3 of lasing section n+1. Since these are intrawell transitions, the scattering rates computed are relatively fast. The radiative transition is also an intrawell transition. One implementation of an embodiment of a step well quantum cascade laser illustrated in FIG. 3 is formed using Al x Ga 1-x As layers having compositions that are, beginning with the left injector, 0.16/0.05/0/0.05/0/0.16/0, and having a thicknesses in nm of 4.6/27.9/1.8/2/6.3/4.7/6.8. In this implementation of an embodiment of a step well quantum cascade laser illustrated in FIG. 3 , E 32 =15.2 meV (˜3.7 THz), E 21 =37.9 meV, and the center 2 nm of the 6.8 nm well is doped to a sheet density of 3.4×10 10 cm −2 . There is reasonably good overlap of the wavefunctions which provides an oscillator strength=2 /mω|<f|d/dx|i>| 2 =0.94 at 9.9 kV/cm (53.6 mV/section), where
=6.582 119 15(56)×10 −22 MeV sec, (3)
m=electron effective mass,
ω=angular frequency,
f=the final state,
i=the initial state.
A simulation of this structure yields a peak gain=2 e 2 2 Δn 3D /m 2 ενωFWHM|<f|d/dx|i>| 2 ˜87 cm −1 , where (4)
=6.582 119 15(56)×10 −22 MeV sec,
m=electron effective mass,
ω=angular frequency,
Δn 3D =3D population inversion,
e=1.602 176 53(14)×10 −19 Coul.,
v=velocity magnitude (speed of light in medium),
FWHM=full width half maximum,
ε=permittivity,
f=the final state,
i=the initial state.
(W. Freeman and G. Karunasiri, Proc. SPIE 7311, 73110V (2009).
FIG. 4 shows an exemplary conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well 6 (having a single step 8 ) and a one well injector 12 . This embodiment includes, in the presence of an applied electric field, a doublet of lower states, E 0 and E 1 , a lower lasing state E 2 , located below the highest point 3 of the only step 8 in the step well 6 , and below the upper lasing state E 3 , which is located near or above the highest point 3 of the only step 8 in the step well 6 .
FIG. 5 shows an exemplary conduction band profile of one lasing section of a step well QC structure having a step well 6 (having a single step 8 ) and a one well injector 12 where the step well 6 trough 13 and injector well 12 trough 19 have different conduction band heights. This embodiment includes, in the presence of an applied electric field, a doublet of lower states, E 0 and E 1 , a lower lasing state E 2 , located below the highest point 3 of the only step 8 in the step well 6 , and below the upper lasing state E 3 , which is located near or above the highest point 3 of the only step 8 in the step well 6 .
FIG. 6 shows an exemplary conduction band profile of one lasing section of one embodiment of a step well QC structure having two different height steps ( 15 , 17 ) and a one well injector 12 . This embodiment includes, in the presence of an applied electric field, a doublet of lower states, E 0 and E 1 , a lower lasing state E 2 , located below the highest point 3 of the first step 15 in the step well 6 , and below the upper lasing state E 3 , which is located near or above the highest point 3 of the highest step 15 in the step well 6 .
FIG. 7 shows an exemplary conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well 6 (having a single step 8 ) and a two well ( 14 , 16 ) injector 12 . This embodiment includes, in the presence of an applied electric field, a triplet of lower states, E 0 , E 1 , E 2 , a lower lasing state E 3 , located below the highest point 3 of the only step 8 in the step well 6 , and below the upper lasing state E 4 , which is located near or above the highest point 3 of the only step 8 in the step well 6 .
FIG. 8 shows an exemplary conduction band profile of one lasing section of one embodiment of a step well QC structure having a step well 6 (having a single step 8 ) and a two well injector 12 . This embodiment includes, in the presence of an applied electric field, a triplet of lower states, E 0 , E 1 , E 2 , a doublet lower lasing state E 3 and E 4 , located near the highest point 3 of the only step 8 in the step well 6 , and below the upper lasing state E 5 , which is located near or above the highest point 3 of the only step 8 in the step well 6 . The lasing section of this embodiment has a two well ( 18 , 20 ) injector 12 . This embodiment allows for resonant tunneling of the lower lasing state, and resonant tunneling/injection of the lower state(s).
While the invention has been described, disclosed, illustrated and shown in various terms of certain embodiments or modifications, the scope of the invention is not intended to be, nor should it be deemed to be, limited thereby and such other modifications or embodiments as may be suggested by the teachings herein are particularly reserved especially as they fall within the breadth and scope of the claims here appended.
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A Quantum Cascade (QC) structure(s) for use in Quantum Cascade Lasers (QCLs) that use step quantum well(s) in which the radiative and LO-phonon transitions are both vertical transitions and within the same step well. This approach allows for a high oscillator strength and uses LO-phonon scattering for fast depopulation of the middle state (lower lasing state) for maintaining a population inversion. The step also reduces unwanted injection into the lower lasing state due to spatial separation of the wavefunctions. It is emphasized that this abstract is provided to comply with the rules requiring an abstract that will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope of the claims.
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CROSS REFERENCE TO RELATED APPLICATIONS
This application is a divisional application of U.S. non-provisional application entitled “OFFSETTING DUAL FLUSH ADAPTER” having Ser. No. 13/096,162, filed Apr. 28, 2011, which claims priority to U.S. provisional application entitled “OFFSETTING DUAL FLUSH ADAPTER” having Ser. No. 61/328,874, filed Apr. 28, 2010, both of which are hereby incorporated by reference in their entireties.
BACKGROUND
Most toilets in the United States feature a single flush capability that typically uses more water than is needed to flush urine and tissue. This translates into a colossal waste of water each year. Also, typical flush valves that include a flapper preclude the use of other flush technologies without significant effort needed to remove a toilet tank, remove an existing flush valve, and install a new style flush valve, or result in limited fit or function.
BRIEF DESCRIPTION OF THE DRAWINGS
Many aspects of the present disclosure can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views.
FIGS. 1A-1D are drawings that provide various views of a single flush toilet flush valve with a dual flush adaptor according to various embodiments.
FIGS. 2A-2C are drawings that provide various views of another single flush toilet flush valve with a dual flush adaptor according to various embodiments.
FIGS. 3A-3E, 4A-4B, 5A-5B, and 6A-6D are drawings that provide various views of a single flush toilet flush valve with other dual flush adaptors according to various embodiments.
FIGS. 7A and 7B are drawings that illustrate the coupling of a dual flush canister to the dual flush adaptor of FIGS. 3A-6D according to various embodiments.
DETAILED DESCRIPTION
With reference to FIGS. 1A-1D , shown are various views of a toilet flush valve 100 that includes an overflow tube 103 . The flush valve 100 is generally employed in gravity toilets and includes an orifice 106 through which water drains into a toilet bowl during a flush of a toilet as can be appreciated. The orifice 106 is typically sealed using a flapper that hinges upon ears 109 that extend from the sides of the overflow tube 103 . Some flush valves do not use a flapper or have ears 109 as such as might be the case with a ball-type flush valve, but typically include an overflow tube 103 . In any event, the flush valves as described herein are those that are configured to seat a flapper, flush ball, gasket, or other sealing member to ensure that water does not leak into the toilet bowl until a flush is initiated.
A sealing washer such as a rubber washer or other sealing structure is sandwiched between the flush valve 100 and the bottom of the tank as can be appreciated. The flush valve 100 also includes a retaining nut 113 that is used to secure the flush valve 100 to the bottom of a toilet tank and serves to compress the rubber washer or other sealing structure. The flush valve 100 includes a threaded portion 116 upon which the retaining nut 113 is fastened. Also, another gasket may be employed to seal between the toilet tank and the toilet bowl.
Also depicted in FIGS. 1A-1D is an adapter 133 . The adapter includes a clamp 136 that can be affixed to the overflow tube 103 as shown. To this end, the adapter 133 can move up and down with the clamp 136 sliding up and down the overflow tube until the clamp 136 is tightened as shown. Attached to the adapter 133 is a gasket 139 . The gasket 139 is configured to be compatible with the flush orifice 106 such that it can mate with the junction forming a seal between the gasket 139 and the flush orifice 106 . Also, the gasket 139 is attached to the bottom of the adapter 133 in such a manner that a seal is formed at the junction between the adapter 133 and the gasket 139 . The adapter 133 may be viewed as a basket that includes a flush orifice 143 that is compatible with various flush mechanisms such as dual flush devices, siphonic flush valves, electronically operated dual flush valves, or other flush mechanisms. Although the following discussion mentions dual flush mechanisms, it is understood that the adapter 133 is not limited for use with such dual flush mechanisms, and that other flush mechanisms may be mated with the adaptor 133 as desired.
The adapter 133 is configured to mate with a flush mechanism such as a dual flush canister so that the dual flush canister can open or close the flush orifice 143 to implement a flush of a toilet. To this end, two different flushes may be implemented. One uses a minimum amount of water to flush urine and tissue down the drain. The second uses an additional amount of water to flush excrement and tissue, etc., down the drain.
To tighten the clamp 136 on the overflow tube 103 , a carriage bolt 153 extends through holes of ears 156 associated with the clamp 136 . The carriage bolt 153 may include a wing nut or other locking nut 159 that, when tightened, causes the leaves of the clamp 136 to compress the overflow tube 103 . The carriage bolt 153 may include a square portion 163 that mates with a square hole in a given one of the ears 156 to prevent the carriage bolt from rotating when the wing nut 159 is tightened. In other embodiments, the clamp 136 may be tightened on the overflow tube 103 using spring clamps, self-tapping screws, rubber ring, or other appropriate fasteners. For example, a zip tie 166 (or cable tie) may be used to tighten clamp 136 on the overflow tube 103 .
By virtue of the adapter 133 being mated with the flush orifice 106 by way of the gasket 139 , an existing single flush valve 100 that may already be installed in a toilet can be converted to a dual flush mechanism. To this end, the adapter 133 and the gasket 139 facilitate conversion of existing single flush valves 100 to dual flush mechanisms. Specifically, the adapter is slid down over the overflow tube 103 until the gasket 139 engages the flush orifice 106 . An individual may then press the adapter 133 downward such that the gasket 139 mates properly with the flush orifice 106 and seals the junction therebetween.
To this end, the gasket 139 may be deformed slightly to provide for a better seal. At this point, the adapter 133 may be held in place until the wing nut 159 is tightened, thereby tightening the clamp 136 onto the overflow tube. In this manner, the adapter 133 is held into place. In addition, when water fills up in a toilet tank, water pressure against the adaptor assembly aids in holding the adapter 133 in the proper position to maintain the seal formed between the flush orifice 106 and the gasket 139 . The flush valve 100 as shown in FIGS. 1A-1D is a horizontal style flush valve in that the flush orifice 106 is oriented in a horizontal direction relative to the bottom wall of a toilet tank in which the flush valve 100 is installed.
With specific reference to FIGS. 1C and 1D , shown are exploded views of the adapter 133 with the gasket 139 separated. As depicted in FIG. 1D , the adapter 133 includes an annular recess 173 which mates up with an inward annular projection 176 on the gasket 139 to provide for a seal between the adapter 133 and the gasket 139 as will be described in greater detail.
With reference next to FIGS. 2A-2C , shown is a flush valve 200 that includes an angled flush orifice 203 . To this end, the flush valve 200 is much the same as the flush valve 100 except for the fact that the flush orifice 203 is angled to accommodate the type of flapper or sealing member used to contain the water in the toilet tank and operate a flush cycle as can be appreciated. The adapter 133 and the clamp 136 are unchanged. The gasket 139 may be shaped to conform with the orifice 203 to the extent that the orifice 203 is elliptical in nature relative to the gasket 139 due to the angling of the flush orifice 203 .
With reference to FIGS. 3A-3E , shown is another arrangement for affixing a dual flush adapter 133 to the overflow tube 103 . The adapter 133 includes at least one arm 303 that extends from the adapter 133 . In the embodiment of FIGS. 3A-3E , two arms 303 extend from the upper rim 306 of the adapter 133 . In other embodiments, the arm(s) 303 may extend from another portion of the adapter 133 , e.g., down members 309 .
A mounting bracket 313 is affixed to the down tube 103 . In the embodiment of FIGS. 3A-3E , the mounting bracket 313 is clamped to the down tube 103 and secured in position by a bolt 316 using a nut or a threaded opening in the mounting bracket 313 . In other embodiments, securing means such as, but not limited to, screws, tabs, ties, etc. may be used to secure the mounting bracket 313 in position on down tube 103 .
The arms 303 are configured to engage with the mounting bracket 313 . In the embodiment of FIGS. 3A-3E , arm 303 includes a serrated edge 319 for positioning of gasket 139 within the flush orifice 203 . The mounting bracket 313 includes a corresponding ratchet mechanism 323 that engages with the serrated edge 319 of the arm 303 to secure the adapter 133 and gasket 139 in position. FIGS. 3D-3E illustrate the variation in positioning of the adapter 133 and gasket 139 to provide for alignment of the gasket 139 with an orifice 203 . Variations in the location of the orifice 203 with respect to the down tube 103 can be accounted for by movement of the arm(s) 303 within the ratchet mechanism(s) 323 . In some embodiments, the ratchet mechanism 323 may allow for movement of the arm 303 in both directions. Alternatively, the ratchet mechanism may only allow the arm 303 to be adjusted in a single direction unless the ratchet mechanism 323 is disengaged from the serrated edge 319 of the arm 303 .
In other embodiments, the mounting bracket 313 includes a securing mechanism in place of the ratchet mechanism 323 that engages with the arm 303 to secure the adapter 133 and gasket 139 in position. The securing mechanism may include an adjusting or set screw or other appropriate securing device that, when engaged with the arm 303 , holds gasket 139 in alignment with orifice 203 . Releasing the securing mechanism allows for adapter adjustment.
Referring next to FIGS. 4A-4B , shown is another arrangement for affixing a dual flush adapter 133 to the overflow tube 103 . The adapter 133 includes an adjustment arm 403 that extends from the adapter 133 . In the embodiment of FIGS. 4A-4B , the adjustment arm 403 extends from the upper rim 306 of the adapter 133 . In other embodiments, the adjustment arm 403 may extend from another portion of the adapter 133 , e.g., a down member 309 .
A mounting bracket 413 is affixed to the down tube 103 . In the embodiment of FIGS. 4A-4B , the mounting bracket 413 is clamped to the down tube 103 and secured in position by a bolt 416 using a nut or a threaded opening in the mounting bracket 413 . In other embodiments, securing means such as, but not limited to, screws, tabs, ties, etc. may be used to secure the mounting bracket 413 in position on down tube 103 .
The adjustment arm 403 is configured to be secured to the mounting bracket 413 using a bolt 419 and nut or other appropriate fastening means. Bolt 419 extends through an extension 423 of the mounting bracket 413 and a slot 426 of the adjustment arm 403 . By rotating the mounting bracket 413 and adjusting the position of bolt 419 within slot 426 , the position of the adapter 133 and gasket 139 may be adjusted to provide for alignment of the gasket 139 with an orifice 203 .
FIGS. 4A-4B illustrate the variation in positioning of the adapter 133 and gasket 139 to provide for alignment of the gasket 139 with an orifice 203 . In FIG. 4A , the mounting bracket 413 and adjustment arm 403 are secured in a first position to align gasket 139 with the orifice 203 . In FIG. 4B , the orifice 203 is located further away from down tube 103 . Accordingly, the mounting bracket 413 has been rotated on the down tube 103 and bolt 419 has been translated within the slot 426 to align gasket 139 with the orifice 203 . The mounting bracket 413 and adjustment arm 403 are secured in this second position to maintain alignment with orifice 203 .
Referring now to FIGS. 5A-5B , shown is another arrangement for affixing a dual flush adapter 133 to the overflow tube 103 . The adapter 133 includes two adjustment arms 403 that extend from the adapter 133 . In the embodiment of FIGS. 5A-5B , the adjustment arms 403 extend from the upper rim 306 of the adapter 133 .
A mounting bracket 513 is affixed to the down tube 103 . In the embodiment of FIGS. 5A-5B , the mounting bracket 513 is clamped to the down tube 103 and secured in position by a bolt 516 using a nut or a threaded opening in the mounting bracket 513 . In other embodiments, securing means such as, but not limited to, screws, tabs, ties, etc. may be used to secure the mounting bracket 513 in position on down tube 103 .
The adjustment arms 403 are configured to be secured to the mounting bracket 513 using a bolt 519 and nut or other appropriate fastening means. Bolts 519 extend through a slot 526 in extensions 523 of the mounting bracket 513 and a slot 426 of the adjustment arms 403 . Slots 426 in the adjustment arms 430 and slots 526 in the mounting bracket extensions 523 allow for repositioning of the adapter 133 and gasket 139 for alignment of the gasket 139 with an orifice 203 without rotating the mounting bracket 513 .
FIGS. 5A and 5B illustrate the variation in positioning of the adapter 133 and gasket 139 to provide for alignment of the gasket 139 with an orifice 203 . In FIG. 5A , the adjustment arms 403 are secured in a first position to align gasket 139 with the orifice 203 . In FIG. 5B , the orifice 203 is located further away from down tube 103 . Accordingly, the bolts 519 have been translated within slots 426 and slots 526 to align gasket 139 with the orifice 203 . The adjustment arms 403 are secured in this second position to maintain alignment with orifice 203 .
Referring to FIGS. 6A-6D , shown is another arrangement for affixing a dual flush adapter 133 to the overflow tube 103 . In the embodiments of FIGS. 6A-6D , the adapter 133 includes a mounting flange 603 affixed to the upper rim 306 of the adapter 133 . In other embodiments, the mounting flange 603 may be affixed to another portion of the adapter 133 , e.g., a down member 309 . A mounting ring 606 extends around the down tube 103 and is fastened to the mounting flange 603 to secure the adapter 133 and gasket 139 in position. With openings 609 aligned, the mounting ring 606 may be secured to the mounting flange 603 by bolts and nuts, screws, zip ties, or other suitable fasteners.
The position of the adapter 133 and gasket 139 may be adjusted using shims 613 and/or rings 606 of various sizes as illustrated in FIG. 6B . The shims 613 include openings 609 that are aligned with the openings 609 of the mounting flange 603 and mounting ring 606 when secured in position on the down tube 103 . FIGS. 6C and 6D illustrate the variation in positioning of the adapter 133 and gasket 139 to provide for alignment of the gasket 139 with an orifice 203 . In FIG. 6C , a first shim 613 a is used to align gasket 139 with the orifice 203 . In FIG. 6D , the orifice 203 is located further away from down tube 103 . Accordingly, a thicker shim 613 b is utilized to align gasket 139 with the orifice 203 . With openings 609 aligned, the mounting ring 606 and shim 613 may be secured to the mounting flange 603 by bolts and nuts, screws, zip ties, or other suitable fasteners.
With reference to FIGS. 7A and 7B , shown is how the adapter 133 mates with a dual flush canister 703 according to various embodiments. The dual flush canister 703 includes mating ears 706 that slide into the grooves 719 and can be rotated within an annular groove. Attached to the dual flush canister 703 is a sealing member 709 that closes the flush orifice 716 of the adapter 133 when the dual flush canister 703 is idle. The sides of the adapter 133 feature water flow openings 713 that allow water to enter into the adapter 133 and flow through the flush orifice 143 when a flush is implemented. A flush is implemented when the mechanisms in the dual flush canister 703 lift the sealing member 709 to allow water to flow into the flush orifice 716 of the adapter and through the flush valve to a toilet bowl. In an alternative embodiment, the adapter 133 may actually be an integrally molded portion of the dual flush canister 703 . Furthermore, the dual flush canister may be similar to the dual flush canister manufactured by OEM toilet manufacturers and suppliers like CRN, LAB, VIB, R&T, WDI and Nison.
It should be emphasized that the above-described embodiments of the present disclosure are merely possible examples of implementations set forth for a clear understanding of the principles of the disclosure. Many variations and modifications may be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the disclosure. All such modifications and variations are intended to be included herein within the scope of this disclosure and protected by the following claims.
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Various methods and systems are provided for offsetting of flush adapters. In one embodiment, an apparatus includes an adapter configured to attach to a flush mechanism configured to provide for a predefined flush capability in a toilet, a gasket attached to adapter, the gasket forming a seal between the flush mechanism and a flush orifice of a flush valve, where the flush valve is configured to seat a sealing member, and means for securing the gasket in position with respect to the flush orifice of the flush valve.
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[0001] The present invention relates to gas sensors, in particular to an optical fibre sensor for measuring the presence and/or quantity of one of more gasses, notably in ambient air.
BACKGROUND AND PRIOR ART
[0002] There exist numerous point sensors exploiting various technologies to detect gases, for example, electrochemical, infrared, semiconductor, pellistors and optical. There is nevertheless a need for improved gas detectors.
SUMMARY OF THE INVENTION
[0003] According to one of its aspects, the present invention provides a gas sensor as defined in claim 1 . Additional aspects are defined in other independent claims. The dependent claims define preferred or alternative embodiments.
[0004] The gas sensor according to the present invention comprises an optical fibre having a gas sensitive detection material at a portion of the external surface of the optical fibre. When exposed to a gas to be detected, the gas sensitive detection material, comprising a porous matrix and a gas sensitive reactant, undergoes a reversible change of absorbance and/or reflectance and/or refractive index at a detection wavelength.
[0005] The use of a sensor based on optical fibres provides various advantages. Historically, optical fibres were developed for long distance transmission of data and a whole technology was then developed to produce sources, detectors, spectrum analysers etc. in the telecom wavelength range which corresponds to the minimum of losses of silica fibres. The optical fibre based sensor may provide one or more of: immunity to interferences, possibilities of interrogation at numerous points on the same fibre, low weight and small volume, flexibility, stability, high temperature tolerance, durability, safety.
[0006] The optical fibre is preferably a silica fibre. This provides low attenuation, particularly at the preferred wavelengths referred to herein, is based on mature technology, can be used with common data processing equipment and is suitable for long distance transmission of data notable in the range of wavelengths 1300 nm-1700 nm, a range which corresponds to low signal losses for silica optical fibres. The silica may be a doped silica. Alternatively, the optical fibre may be a glass fibre or a polymer optical fibre, for example a PMMA (Poly(methyl methacrylate)) optical fibre.
[0007] The optical fibre is preferably a mono-mode optical fibre, also referred to as single-mode optical fibre. This facilitates retention of fidelity over long distances and allows use of a spectra having a structure which is fairly easy to interpret using standard equipment. Alternatively, the optical fibre may be a multi-mode optical fibre. The optical fibre may be a micro-structured optical fibre, notably photonic crystal fibre, a multicore optical fibre or a hollow core optical fibre.
[0008] In a preferred embodiment, the optical fibre is a single-mode silica optical fibre.
[0009] Preferably the optical fibre comprises an optical core and a cladding, both of which may be of silica. The core and/or the cladding may each be homogeneous.
[0010] The gas sensitive detection material may be provided in the form of a layer; it preferably has a significant change in reflectance and/or absorbance and/or refractive index in the range of wavelengths 1300 nm-1700 nm. This makes it particularly suitable for use with optical fibres, notably silica type optical fibres. The detection wavelength may be in the range from 300 nm to 1700 nm, preferably from 1100 nm to 1600 nm, more preferably from 1380 nm to 1550 nm.
[0011] The length of the optical fibre may be at least about 50 m, at least about 100 m, at least about 500 m or at least about 1 km.
[0012] The gas sensitive detection material may be arranged at a tip of the optical fibre and/or at at least one portion of the external surface of the optical fibre along the fibre's length. Notably, the gas sensitive detection material may be arranged at an external peripheral surface of the optical fibre at a position where the fibre cladding is not recessed. A plurality of spaced gas sensitive detection materials may be arranged along the length of the fibre. Such materials may be spaced by a distance of at least 5 m, at least 10 m, at least 20 m at least 50 m at least 100 m, at least 200 m or at least 500 m.
[0013] In a preferred embodiment, the gas sensitive detection material may be arranged on the external surface of the optical fibre at a position along the length of the optical fibre over an optical grating, notably a Fibre Bragg Grating (FBG), Long Period Fibre Grating (LPFG) or Tilted Fibre Bragg Grating. Preferably, the optical grating is a Tilted Fibre Bragg Grating; this may be used to intrinsically provide temperature-insensitive operation. The optical grating may be arranged within the core and/or within the cladding of the optical fibre.
[0014] The optical fibre may further comprise structures than can couple light from the fibre core to the cladding, for example etched optical fibre, D-shaped optical fibre, tapers or hybrid interferometric structures made, for example, by splicing optical fibres of different diameters. These structures may couple modes and/or evanescent waves to the surroundings.
[0015] When a plurality of spaced gas sensitive detection materials are provided, each may have its own associated optical grating and be arranged at spaced positions along the length of the optical fibre. This may be used for quasi-distributed sensing (as opposed to a single point measurement). For example, at least 5, 10 or 20 spaced gas sensitive detection materials may be provided along the length of the fibre. One or more temperature reference indicators may be provided as part of the sensor, for example, to enable an indication of and/or compensation for temperature, notably provided by gratings, preferably of the same type associated with the gas sensitive detection material(s).
[0016] The refractive index of the gas sensitive detection material may be in the range 1.3 to 1.6, preferably in the range 1.4 to 1.5. Preferably, the difference between the refractive index of the gas sensitive detection material and the refractive index of the optical fibre at an interface between the gas sensitive detection material and the optical fibre is less than 15%, preferably less than 10%, more preferably less than 5%, notably at the detection wavelength(s). This reduces undesired reflection at the detection wavelength(s) at this interface.
[0017] The gas sensitive detection material may have a thickness which is at least 50 nm, preferably at least 500 nm and/or no more than 15 μm, preferably no more than 5 μm. Particularly in the case of an inorganic and/or sol gel matrix, the thickness is preferably no more than 2 μm. If the gas sensitive detection material is too thick it may have a tendency to have or develop cracks or the diffusion may be too long causing an increase of the response time. If it is too thin, notably with respect to the detection wavelength(s), the amount of the reversible change of absorbance and/or reflectance may be too weak to be easily detect by signal processing equipment.
[0018] The gas sensitive detection material and/or gas sensitive reactant may have a molar absorptivity of at least 5×10 5 m −1 ·mol −1 ·l −1 , preferably of at least 1×10 6 m −1 ·mol −1 ·l −1 at a detection wavelength of 1550 nm. The gas sensitive reactant may have a molar absorptivity of at least 1×10 6 m −1 ·mol −1 · −1 preferably 1×10 7 m −1 ·mol −1 ·l −1 at a detection wavelength of 650 nm.
[0019] The gas sensitive detection material may have a length which is at least 2 , at least 5 mm, at least 1 cm, at least 5 cm or at least 10 cm and/or no more than 50 cm, no more than 30 cm or no more than 20 cm. The gas sensitive detection material preferably extends around the entire circumference of the optical fibre.
[0020] The use of a porous matrix as part of the gas sensitive detection material facilitates diffusion of the gas to be detected into the body of the gas sensitive detection material. This allows the gas to be detected to easily and quickly reach and interact with the gas sensitive reactant in the gas sensitive detection material. This improves the response time of the sensor.
[0021] The porous matrix may be an inorganic matrix, notably a matrix of a mineral material, preferably comprising or consisting essentially of silica. It may be a sol-gel matrix. The porous matrix may be an organic matrix, notably a polymer matrix. It may be a hybrid inorganic/organic matrix. Preferably, the porous matrix is a silica matrix.
[0022] The porous matrix, notably before impregnation with the gas sensitive reactant, may have a porosity which is at least 25%, preferably at least 30% and/or which is no more than 70%, preferably no more than 60%, more preferably no more than 50%. The porosity represents the percentage space of pores in the total volume. If the porosity of the porous matrix before impregnation is too low then the matrix will only be able to contain a small quantity of the quantity of gas sensitive reactant; the change in the gas sensitive detection material will then be difficult to detect with signal processing equipment. If the porosity of the porous matrix before impregnation is too high, the mechanical properties of the porous matrix may be low and the structure of the matrix may collapse when loaded with a desired amount of gas sensitive reactant.
[0023] The gas sensitive detection material may have a porosity which is at least 15%, preferably at least 20% and/or no more than 60%, preferably no more than 40%.
[0024] The pores of the porous matrix may have an average diameter which is at least 4 nm, preferably at least 10 nm or at least 20 nm and/or no more than 100 nm, preferably no more than 80 nm.
[0025] Preferably, the pores of the porous matrix have a diameter that is at least 10 times smaller than the detection wavelength. This provides good homogeneity for detection of the change in the gas sensitive detection material and decreases scattering at the detection wavelength.
[0026] The gas sensitive reactant may comprise a lanthanide bisphtalocyanine, for example lutetium bisphthalocyanine (LuPc 2 ). This provides a reactant which is reversible, notably at ambient temperature. In addition, it provides a reactant that has a suitable change at the preferred detection wavelength(s). Preferably, the gas sensitive reactant is a chemical compound.
[0027] Preferably the gas sensitive reactant is insoluble in water and/or non-volatile and/or stable at operating temperatures of the sensor, for example from about −30° C. to about 45° C.; it is preferably non-soluble in common solvents, for example ethanol and/or not sensitive to humidity, notably relative humidity in the range 5-95%. Preferably, the gas sensitive reactant is non-responsive and/or non-reactive to oxygen O 2 ; this is particularly useful when the gas sensor is to be used for a gas to be detected in an oxygen containing gaseous atmosphere, notably air.
[0028] The gas sensitive reactant is preferably present in the form of a solid dispersed within the porous matrix, notably in the form of crystals. The diameter of the crystals, notably with respect to at least 90% of the crystals and preferably for the average diameter, may be less than 50 nm, preferably less than 30 nm, more preferably less than 10 nm. This provides a rapid response time for the gas sensitive detection material. The choice of the pore sizes referred to above facilitate obtaining the aforementioned crystal sizes.
[0029] The reversible change which the gas sensitive detection material undergoes is preferably a chemical reaction that proceeds in either direction by variation of the quantity of the gas to be detected to which it is exposed. Preferably, the reaction is reversible at the operating temperature of the sensor, notably at a temperature of from −30° C. to 45° C.
[0030] The gas sensitive reactant may be a neutral molecule, for example LuPc 2 which has an optical spectrum different to the optical spectrum of the oxidised form of the molecule, LuPc 2 + notably at the preferred detection wavelength(s). When the molecule is exposed to a gas, for example NO 2 , the oxidation may be partial and equilibrated and the complex LuPc 2 + /NO 2 − is formed. Without the gas, this complex reverts back to the initial composition, in this case, LuPc 2 and NO 2 . For LuPc 2 , in the visible spectrum, the neutral molecule is green, the oxidised form LuPc 2 30 is red and the reduced form LuPc 2 − is blue. The gas sensitive reactant may have at least three oxidation states, notably at least three stable oxidation states. The reaction may be reversed without other external influence at ambient atmosphere conditions. The speed of the reaction, notably reverting to the condition in the absence of the gas to be detected, may be increased by one or more external factors, for example by exposing the gas sensitive detection material to UV radiation, notably having a wavelength of less than about 400 nm, preferably of less than about 380 nm and/or greater than 10 nm, preferably greater than 100 nm. The gas sensitive detection material may be exposed to UV radiation by means of radiation which is introduced in to the optical fibre, for example periodically or when desired, and which may be directed to the gas sensitive detection material, for example by a grating. For example, UV radiation may be provided via the optical fibre by exploiting higher order modes of a grating, for example the harmonic at smaller wavelengths in the UV range with the fundamental harmonic being in the IR range. UV radiation may be provided from an external UV radiation source, for example a UV lamp directed towards an external surface of gas sensitive detection material. The UV radiation may provide energy to facilitate or accelerate reducing an oxidised form of the gas sensitive reactant.
[0031] Preferably, the reversibility of the sensor is such that the difference between the absorbance and/or reflectance and/or refractive index of the gas sensitive reactant between:
[0032] a) a condition prior to being exposed to the gas to be detected; and
[0033] b) a condition in which it has been exposed to the gas to be detected and is subsequently exposed to an atmosphere that does not include the gas to be detected;
[0000] is less than 20%, preferably less than 10%, more preferably less than 5%, notably at the detection wavelength(s) and notably after a period of less than 8 hours, preferably a period of less than 4 hours, less than 2 hours, less than 1 hour or less than 30 minutes, with or without external application of energy from an external source, preferably at ambient atmospheric conditions and notably at a 20° C. and 1 atmosphere in ambient or test air.
[0034] When the gas sensitive detection material is kept in conditions in which the gas to be detected is not present so as to become stable and is subsequently subjected to at least 10 ppm of a gas to be detected, the change of reflectance and/or absorbance and/or refractive index may be 10% in less than 10 minutes, preferably in less than 5 minutes, more preferably in less than 2 minutes.
[0035] The gas to be detected may comprise an oxidising gas, notably an oxidising gas selected from the group consisting of: a nitrogen oxide, notably NO 2 , O 3 and mixtures thereof. Such detection may be useful for monitoring atmospheric pollution in air.
[0036] The gas to be detected may comprise a reducing gas, notably a reducing gas selected from the group consisting of: CO, NH 3 , formaldehyde and mixtures thereof.
[0037] The sensor may detect concentration of at least 1 ppb and/or at least 5 ppb and/or at least 20 ppb and/or at least 100 ppb and/or at least 1 ppm and/or at least 10 ppm of the gas to be detected; it may detect a concentration of gas in the range 1-10 ppm.
[0038] Advantageously, the gas sensor according to the present invention may detect variation in absorbance or reflectance of at least 0.01 or 0.1 dB. The variation in optical absorbance or reflectance of the gas sensitive detection material at the detection wavelength between a first condition in which the sensor is detecting the gas to be detected and a second condition in which no gas to be detected is present may be at least 0.02, preferably at least 0.04 and more preferably at least 0.06.
[0039] The gas sensor of the present invention may be used for qualitative and/or quantitative measurements. It may detect the absolute amount of gas to be detected in the gaseous atmosphere and/or detect the relative amount or change in the amount of gas to be detected.
[0040] The gas sensor may comprises a gas filter, which may comprise activated carbon, arranged between the gas detection material and the gaseous atmosphere to filter one or more gasses to be detected and/or to reduce the concentration of the gas to be detected by the gas sensitive detection material.
[0041] A mechanical packaging may surround and/or block and/or be applied on or around the gas sensitive detection material, for example a metallic grid or a sintering, notably a ceramic sintering. The packaging may comprise a filter. For example the packaging may comprise a sintered material having a functioned surface provided by a filtering material or a metallic grid retaining a filter.
[0042] The gas sensor may be manufactured by:
Depositing the porous matrix at a portion of the external surface of an optical fibre; and Subsequently impregnating the at least porous matrix with at least a gas reversible reactant.
[0045] This allows good control of distribution of the gas reversible reactant within the gas sensitive detection material.
[0046] The gas sensor may be used with a system comprising signal processing equipment which may transmit and/or detect and/or receive and/or analyse a signal at the detection wavelength(s). The signal processing equipment may comprise a light source and/or receiver or detector, for example an ASE (Amplified Spontaneous Emission) and/or a signal analyser for example an OSA (Optical Spectra Analyser). The light source may comprise a white light source, for example halogen lamp, laser diode, super luminescent laser diode, ASE source or wavelength tuneable laser. The detector may include one or more photodiode(s), power meter(s), optical spectrum analyser, and/or optical time domain reflectometer(s).
[0047] The transmitted and/or detected signal may be non-polarised or polarised. When polarised it is preferably polarised in P mode (which generally provides a better sensitivity than S mode) but it may be in S mode.
[0048] Preferably, the sensor is substantially insensitive to humidity. It is preferably humidity neutral, that is to say that the difference between the absorbance and/or reflectance of the sensor, between:
[0049] a) a condition wherein the humidity is 20% at a temperature of 20° C. and at a pressure of 1 atmosphere; and
[0050] b) a condition wherein the humidity is 80% at a temperature of 20° C. and at a pressure of 1 atmosphere; and
[0000] in which the gas sensor has been exposed to the same quantity of gas to be detected, notably 1ppm in air and/or 0ppm in air is less than 20%, preferably less than 10%, more preferably less than 5%, notably at the detection wavelength(s) and notably after a period of at least 8 hours, preferably a period of at least 4 hours, at least 2 hours, at least 1 hour or at least 30 minutes, with or without external application of energy from an external source.
[0051] The sensor is preferably used in ambient air, notably to measure or monitor air pollutant gasses. It may be used, for example, in road tunnels, car parks, storage halls, floor voids, cable ducts or sewers. It may be used for gas leak detection or for detecting or monitoring in a large open space. Where a single fibre having a plurality of spaced gas sensitive detection materials is used for air pollution and/or gas detection this provides an easily installed and cost efficient system for large areas.
DESCRIPTION OF THE FIGURES
[0052] FIG. 1 is a schematic cross-section (not to scale) showing a gas sensor
[0053] FIG. 2 is a schematic cross-section (not to scale) showing an alternative gas sensor
[0054] FIG. 3 shows a TEM (Transmission Electron Microscopy) image of a porous matrix
[0055] FIGS. 4, 5, 6 and 7 are graphs showing the response of a gas sensor
[0056] FIG. 8 is a graph showing response of a material not in accordance with the invention
DESCRIPTION OF PREFERRED EMBODIMENTS
EXAMPLE 1
[0057] The optical fibre ( 2 ) shown in FIG. 1 comprises a cladding ( 12 ) and a core ( 11 ) and is a standard mono-mode fibre manufactured by Dow Corning. The core has a refractive index of 1.45 at a wavelength of 500 nm.
[0058] A gas sensitive detection material having a thickness of about 1 μm ( 14 ) is arranged on the surface of on a tip ( 13 ) of the optical fibre ( 2 ). A broad band ASE source (not shown) is connected at the other end of the fibre and transmits an incident wavelength spectrum ( 3 ) varying from 1200 nm to 1800 nm. The reflected spectrum is followed by means of an OSA (Optical Spectra Analyser). The resolution of the spectrum which is shown in FIG. 4 is 1 pico meter (pm). The detection wavelength is 1540 nm.
[0059] The sensor is held in a gas stream consisting of test air in a gas chamber containing controlled test air. The test air consists of about 79% nitrogen N 2 and about 21% oxygen O 2 . For testing, the gaseous atmosphere is maintained at a temperature of 20° C., a pressure of about 1 atmosphere and a relative humidity of less than 5%. A concentration of 3 ppm of NO 2 is subsequently introduced into the stream of test air directed towards the sensor inside the gas chamber. The reflected light spectrum is analysed and provides an indication of the NO 2 gas concentration. The results of reflectance are shown in FIG. 4 and FIG. 5 .
EXAMPLE 2
[0060] In the example shown in FIG. 2 , the gas sensitive detection material ( 14 ) is arranged on the external surface of the optical fibre at a position along the length of the optical fibre over a Tilted Fibre Bragg Gratings ( 20 ).
[0061] One or more additional gas sensitive detection materials (not shown) each having its own associated Tilted Fibre Bragg Gratings may be arranged at spaced positions along the length of the optical fibre.
[0062] The reflected spectrum from a broad band ASE source which transmits a wavelength spectrum ( 3 ) varying from 1200 nm to 1800 nm through the optical fibre is followed by means of an OSA (Optical Spectra Analyser).
[0063] In each of the examples, the gas sensitive detection material comprises a porous matrix which consists of a porous silica deposited by sol-gel and having an average pore diameter of 50 nm which is impregnated with lutetium bisphthalocyanine (LuPc 2 ). The LuPc 2 fills about 33% of the pore volume. The gas sensitive detection material in these examples has an optical absorbance of about 0.06 at 1550 nm which is easily measured; the variations are of the order of 0.02 to 0.06. The LuPc 2 has a molar absorptivity of about 1.2×10 6 m −1 ·mol −1 ·l −1 at 1550 nm and about 3.0×10 7 m −1 ·mol −1 ·l −1 at 650 nm.
[0064] FIG. 3 shows an image of a porous matrix. As can be seen from the scale indicating 50 nm, the porous matrix has pores having an average diameter of between 4 and 6 nm.
[0065] FIG. 4 shows reflectance (in dB) as a function of wavelength for the gas sensor of example 1. Each curve shows the reflectance measured after a different time delay after the sensor is exposed to the mixture of 3 ppm of NO 2 in test air. The curve ( 40 ) is the curve of reflectance at 0 minute i.e. stable conditions when held in test air with no NO 2 , the curve ( 41 ) is the curve of the reflectance after 10 minutes of continuous exposure to the gas flow consisting of a mixture of 3 ppm of NO 2 in test air, while the intervening curves are reflectance at successive one minute intervals between 0 and 10 minutes. The reflectance is shown in a preferred range of detection wavelengths, between 1500 nm and 1600 nm. For example, the change of reflectance between the curve ( 40 ) and the curve ( 41 ) at a detection wavelength 1536 nm is about 2 dB.
[0066] FIG. 5 shows the evolution in time of the reflectance (in dB) of the gas sensor subjected to cycles of
[0067] i) being exposed to the mixture of 3 ppm of NO 2 in test air for a short time (about 15 minutes) e.g. starting at the position indicated at 50
[0068] ii) subsequently being held in a stream of test air with no NO 2 present e.g. starting at the position indicated at 50 ′
[0000] at the detection wavelength 1540 nm.
[0069] Just prior to the start of the second cycle illustrated, the reflectance indicated at 51 has reverted to about 90% of the initial reflectance at 50 after about 85 minutes in test air. The second cycle then begins, the sensor being exposed again to the gas stream comprising a mixture of 3 ppm of NO 2 in test air for about 15 minutes during which time the reflectance again rises before the gas stream is switched back to test air with no NO 2 present causing the reflectance to fall back to approximately the value indicated at 51 after about 85 minutes.
[0070] FIG. 6 and FIG. 7 show the wavelength of the absorbance of the gas sensor at three different statuses:
curve 61 : exposed to test air (with no NO 2 present) curve 62 : 2 minutes after continuous exposure to a mixture of 10 ppm of NO 2 in test air curve 63 : 8 hours after subsequent exposure to test air (with no NO 2 present).
[0074] The change in absorbance in the wavelengths 1200-1600 nm shown by curve 62 allows monitoring at these wavelengths.
[0075] FIG. 8 shows the wavelength of the absorbance of a solid layer of LuPc 2 (ie not held within a porous matrix) at three different statuses: in test air, 10 minutes after the continuous exposure to 10 ppm of NO 2 , 110 minutes after the continuous exposure to NO 2 . The optical change is very small and thus difficult to detect.
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The present invention relates to gas sensors, in particular, to an optical fibre sensor for measuring the presence and/or quantity of one of more gasses, the gas sensor comprising an optical fibre, and a gas sensitive detection material at a portion of the surface of the optical fibre, said gas sensitive detection material comprising a gas sensitive reactant and a porous matrix, wherein the gas sensitive detection material undergoes a reversible change of reflectance and/or absorbance at a detection wavelength when subjected to a gas to be detected.
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CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application claims priority to U.S. Provisional Patent Application No. 60/842,818 filed Sep. 7, 2006. The contents of this provisional patent application are incorporated herein by reference in their entirety.
FIELD
[0002] This disclosure relates to native semiconductor thin films formed from Group IV nanoparticle materials.
BACKGROUND
[0003] The Group IV semiconductor materials enjoy wide acceptance as the materials of choice in a range devices in numerous markets such as communications, computation, and energy. Currently, particular interest is aimed in the art at improvements in semiconductor thin film technologies due to the widely recognized disadvantages of the current chemical vapor deposition (CVD) technologies.
[0004] In that regard, with the emergence of nanotechnology, there is in general growing interest in leveraging the advantages of these new materials in order to produce low-cost devices with designed functionality using high volume manufacturing on nontraditional substrates. It is therefore desirable to leverage the knowledge of Group IV semiconductor materials and at the same time exploit the advantages of Group IV semiconductor nanoparticles for producing novel thin films which may be readily integrated into a number of devices. Particularly, Group IV nanoparticles in the range of between about 1.0 nm to about 100.0 nm may exhibit a number of unique electronic, magnetic, catalytic, physical, optoelectronic, and optical properties due to quantum confinement and surface energy effects.
[0005] With respect to thin films compositions utilizing nanoparticles, U.S. Pat. No. 6,878,871 describes photovoltaic devices having thin layer structures that include inorganic nanostructures, optionally dispersed in a conductive polymer binder. Similarly, U.S. Patent Application Publication No. 2003/0226498 describes semiconductor nanocrystal/conjugated polymer thin films, and U.S. Patent Application Publication No. 2004/0126582 describes materials comprising semiconductor particles embedded in an inorganic or organic matrix. Notably, these references focus on the use of Group II-VI or III-V nanostructures in thin layer structures, rather than thin films formed from Group IV nanostructures.
[0006] An account of nanocrystalline silicon particles of about 30 nm in diameter, and formulated in a solvent-binder carrier is given in International Patent Application No. WO2004IB00221. The nanoparticles were mixed with organic binders such as polystyrene in solvents such as chloroform to produce semiconductor inks that were printed on bond paper without further processing. In U.S. Patent Application Publication No. 2006/0154036, composite sintered thin films of Group IV nanoparticles and hydrogenated amorphous Group IV materials are discussed. The Group IV nanoparticles are in the range 0.1 to 10 nm, in which the nanoparticles were passivated, typically using an organic passivation layer. In order to fabricate thin films from these passivated particles, the processing was performed at 400° C., where nanoparticles below 10 nm are used to lower the processing temperature. In both examples, significant amounts of organic materials are present in the Group IV thin film layers, and the composites formed are substantially different than the well-accepted native Group IV semiconductor thin films.
[0007] U.S. Pat. No. 5,576,248 describes Group IV semiconductor thin films formed from nanocrystalline silicon and germanium of 1 nm to 100 nm in diameter, where the film thickness is not more than three to four particles deep, yielding film thickness of about 2.5 nm to about 20 nm. For many electronic and photoelectronic applications, Group IV semiconductor thin films of about 150 nm to 3 microns are desirable.
[0008] Therefore, there is a need in the art for native Group IV semiconductor thin films of about 150 nm to 3 microns in thickness fabricated from Group IV semiconductor nanoparticles, which thin films are readily made using high volume processing methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a flow chart that depicts processing steps for the formation of embodiments of Group IV semiconductor thin films.
[0010] FIG. 2 is a schematic which depicts the formation of embodiments of Group IV semiconductor thin films from a porous compact film in an inert environment.
[0011] FIGS. 3A and 3B are scanning electron micrographs (SEMs) of silicon nanoparticle thin films comparing thin films formed from different deposition methods.
[0012] FIGS. 4A and 4B are SEM side views of an embodiment of a silicon nanoparticle thin film before ( 4 A) and after ( 4 B) thin film fabrication.
[0013] FIG. 5 is a graph showing the comparison of X-ray diffraction (XRD) data for an embodiment of a sintered thin film in comparison to the nanoparticle starting material.
[0014] FIG. 6 is an SEM side view of another embodiment of a silicon nanoparticle thin film.
[0015] FIG. 7 is a graph showing the characteristic current versus voltage responses for different embodiments of silicon nanoparticle thin films.
[0016] FIG. 8 is a side view of a silicon nanoparticle thin film which has been processed using pressure.
[0017] FIGS. 9A and 9B are SEM plan views of germanium films before ( FIG. 9A ) and after ( FIG. 9B ) thin film fabrication.
DETAILED DESCRIPTION
[0018] What is disclosed herein are embodiments of native Group IV semiconductor thin films formed from coating substrates using dispersions of Group IV nanoparticles, methods for producing such Group IV semiconductor thin films, as well as embodiments of compositions of Group IV semiconductor nanoparticles, and methods for formulating the same.
[0019] For the purposes of this disclosure and unless otherwise specified, “a” or “an” means “one or more.” All patents, applications, references and publications cited herein are incorporated by reference in their entirety to the same extent as if they were individually incorporated by reference.
[0020] The materials, methods, and compositions evolved from the inventors' observations that by keeping embodiments of the Group IV semiconductor nanoparticles in an inert environment from the moment they are formed through the formation of Group IV semiconductor thin films, that embodiments of the thin films so produced have properties characteristic of bulk semiconductor materials. As will be discussed in more detail below, such properties include, but are not limited by, electrical, spectral absorbance, and photoconductive thin film properties.
[0021] As used herein, the term “Group IV semiconductor nanoparticle” generally refers to Group IV semiconductor particles having an average diameter between about 1.0 nm to 100.0 nm and may, in some instances, include elongated particle shapes, such as nanowires, or irregular shapes, in addition to more regular shapes, such as spherical, hexagonal, and cubic nanoparticles. Additionally, the nanoparticles may be single-crystalline, polycrystalline, or amorphous in nature. A plurality of nanoparticles may include nanoparticles of a single type of crystallinity or may consist of a range or mixture of crystallinity (i.e., some particles crystalline, others amorphous).
[0022] In that regard, Group IV semiconductor nanoparticles have an intermediate size between individual atoms and macroscopic bulk solids. In some embodiments, Group IV semiconductor nanoparticles have a size on the order of the Bohr exciton radius (e.g., 4.9 nm), or the de Broglie wavelength, which allows individual Group IV semiconductor nanoparticles to trap individual or discrete numbers of charge carriers, either electrons or holes, or excitons, within the particle. The Group IV semiconductor nanoparticles may exhibit a number of unique electronic, magnetic, catalytic, physical, optoelectronic and optical properties due to quantum confinement and surface energy effects. For example, Group IV semiconductor nanoparticles exhibit luminescence effects that are significantly greater than, as well as melting of nanoparticles substantially lower than the complementary bulk Group IV materials. These unique effects vary with properties such as size and composition of the nanoparticles. For example, and as will be discussed in more detail below, the melting of germanium nanoparticles is significantly lower than the melting of silicon nanoparticles of comparable size.
[0023] It is contemplated that only Group IV semiconductor nanoparticles of suitable quality be used as starting materials for embodiments of the thin film compositions disclosed herein. Particle quality includes, but is not limited by, particle morphology, average size, size distribution, and purity. For embodiments of disclosed Group IV semiconductor particles, suitable nanoparticle materials useful as starting materials have distinct particle morphology, with low incidence of particle clumping, agglomeration, or fusion. As was mentioned previously, the properties that are imparted for Group IV semiconductor nanoparticles are related closely to the particle size. In that regard, for many applications, a monodisperse population of particles of specific diameters is also indicated. Finally, with respect to purity, the Group IV semiconductor nanoparticles must be substantially oxygen free.
[0024] In consideration of the relationship between particle size and unique properties of Group IV semiconductor nanoparticles, for nanoparticles of about 1.0 nm to about 10 nm, at the lower end of what is defined as colloidal, the surface area to volume ratio, is a hundred to a thousand times greater than for colloids 1.0 micron in size at the other end of the range of what is defined as colloidal. These high surface areas, as well as other factors, such as, for example, the strain of the Group IV atoms at curved surfaces, are conjectured to account for the inventors' observations of the extraordinary reactivity of these Group IV semiconductor nanoparticles.
[0025] As a result of these observations, as shown in step 110 of process flow chart 100 shown in FIG. 1 , scrupulous care has been taken to produce hydrogen terminated Group IV semiconductor nanoparticles fabricated in an inert environment, and as such, substantially free of oxygen. It is known that for bulk materials, substantially free of oxygen falls in the range of about 10 17 to 10 19 oxygen atoms per cubic centimeter of Group IV semiconductor material. In comparison, for example, for semiconductor grade silicon, there are 5.0×10 22 silicon atoms per cubic centimeter, while for semiconductor grade germanium there are 4.4×10 22 germanium atoms per cubic centimeter. In that regard, oxygen can be no greater than about 2 parts per million to about 200 parts per thousand as a contaminant in Group IV semiconductor materials. Therefore, it is indicative that embodiments of Group IV semiconductor thin films disclosed herein are substantially oxygen free if they have comparable electrical and photoconductive properties versus the response of bulk Group IV semiconductor materials.
[0026] Though as previously discussed a substantially oxygen free environment is indicated in the fabrication and handling of the Group IV semiconductor nanoparticles, as used herein, “inert” is not limited to only substantially oxygen-free. It is recognized that other fluids (i.e., gases, solvents, and solutions) may react in such a way that they negatively affect the electrical and photoelectrical properties of Group IV semiconductor nanoparticles. Accordingly, an inert environment for the purposes of this disclosure is an environment in which there are no fluids (gases, solvents, and solutions) that react in such a way that they would negatively affect the electrical and photoelectrical properties of the Group IV semiconductor nanoparticles. Similarly, an inert gas is any gas that does not react with the Group IV semiconductor nanoparticles in such a way that it negatively affects the electrical and photoelectrical properties of the Group IV semiconductor nanoparticles. Likewise, an inert solvent is any solvent that does not react with the Group IV semiconductor nanoparticles in such a way that it negatively affects the electrical and photoelectrical properties of the Group IV semiconductor nanoparticles. Finally, an inert solution is mixture of two or more substances that does not react with the Group IV semiconductor nanoparticles in such a way that it negatively affects the electrical and photoelectrical properties of the Group IV semiconductor nanoparticles.
[0027] The Group IV semiconductor nanoparticles may be made according to any suitable method, several of which are known, provided they are initially formed in an environment that is substantially inert. Examples of inert gases that may be used to provide an inert environment include nitrogen and the rare gases, such as argon. As used herein, the terms “substantially oxygen free” in reference to environments, solvents, or solutions refer to environments, solvents, or solutions wherein the oxygen content has been substantially reduced to produce Group IV semiconductor thin films having no more than 10 17 to 10 19 oxygen per cubic centimeter of Group IV semiconductor thin film.
[0028] In some instances a substantially oxygen-free conditions will contain no more than about 10 ppm oxygen. This includes embodiments where the substantially oxygen-free conditions contain no more than about 1 ppm oxygen and further includes embodiments where the substantially oxygen-free conditions contain no more than about 100 ppb oxygen. For example, if the Group IV semiconductor nanoparticles are made in a solvent phase, they should be removed from solvent and further processed under vacuum or an inert, substantially oxygen-free atmosphere. In another example, the solvent in which the Group IV semiconductor nanoparticles are made may be an anhydrous, deoxygenated liquid held under vacuum or inert gas to minimize the dissolved oxygen content in the liquid. Alternatively, the Group IV semiconductor nanoparticles may be made in the gas phase or in a plasma reactor in an inert, substantially oxygen-free atmosphere.
[0029] Examples of methods for making Group IV semiconductor nanoparticles include plasma aerosol synthesis, gas-phase laser pyrolysis, chemical or electrochemical etching from larger Group IV semiconductor particles, reactive sputtering, sol-gel techniques, SiO 2 implantation, self-assembly, thermal vaporization, synthesis from inverse micelles, and laser ablation/immobilization on self-assembled monolayers.
[0030] When the Group IV semiconductor nanoparticles are made by etching larger nanoparticles to a desired size, the nanoparticles are considered to be “initially formed” once the etching process is completed. Descriptions of etching may be found in references such as Swihart et al., U.S. Patent Application Publication No. 2004/0229447, filed on Nov. 8, 2004. In the preparation of such descriptions for etching, there is no disclosure for maintaining the Group IV semiconductor materials in an inert, substantially oxygen-free environment. When preparing etched Group IV semiconductor nanoparticles as starting material for embodiments of the disclosed passivated Group IV semiconductor nanoparticles, subsequent to the etching step done under oxidizing conditions, a final etch step using a substantially oxygen-free solution of aqueous hydrofluoric acid (HF) is done. Additionally, any further processing, such as transferring the particles for storage, is done so as to maintain the nanoparticles in substantially oxygen-free conditions. For example, the hydrogen-terminated Group IV nanoparticles so formed may be transferred to an inert, substantially oxygen-free environment.
[0031] It is contemplated that plasma phase methods for producing Group IV semiconductor nanoparticles produce Group IV semiconductor nanoparticles of the quality suitable for use in making embodiments of disclosed Group IV semiconductor thin films. Such a plasma phase method, in which the particles are formed in an inert, substantially oxygen-free environment, is disclosed in U.S. patent application Ser. No. 11/155,340, filed Jun. 17, 2005; the entirety of which is incorporated herein by reference.
[0032] In reference to step 120 of process flow chart 100 shown in FIG. 1 , once Group IV semiconductor nanoparticles having a desired size and size distribution have been formed in an inert, substantially oxygen-free environment, they are transferred to an inert, substantially oxygen-free dispersion solvent or solution for the preparation of embodiments dispersions and suspensions of the nanoparticles; or preparation of an ink. The transfer may take place under vacuum or under an inert, substantially oxygen-free environment. The solvents and solutions are prepared as anhydrous, for example using desiccants such as zeolites, and deoxygenated for example by sparging or freezing followed by pumping the headspace. As will be discussed in more detail subsequently, it is contemplated that one embodiment for the deposition of the dispersion of Group IV nanoparticles on a substrate is printing. In that regard, in a broad definition of an ink defined as a fluid used for printing, the dispersions of Group IV nanoparticles are in that context referred to as inks.
[0033] As those of ordinary skill in the art are aware, inks used in more traditional applications, such as graphics, are complex solutions having additives that may include numerous organic species, such as viscosity enhancers, anionic binders, and antifoaming agents. However, for the formation of an native Group IV thin film, the use of such organic additives is contraindicated, since they are frequently not volatile, and moreover at the temperatures contemplated for sintering, may decompose, or carbonize, rendering an native Group IV semiconductor thin film contaminated thereby.
[0034] Further, nanoparticles are often dispersed in solvents using surface passivation of the nanoparticles; most typically with an organic ligand that is bonded in some fashion (e.g., covalent, ionic, dipole-dipole, and the like) to atoms at the surface of the material. In the case of Group IV semiconductor nanoparticles, such surface passivation is often done using an insertion reaction with alkenes and alkynes, such as octene, octyne, octadecene, and the like. Additionally, solvents such as alcohols, ketones, and ethers, which have been previously reported as good dispersive solvents for some nanoparticles, react with the highly reactive surface atoms of the Group IV semiconductor nanoparticles to form organic passivated surfaces. For the same reason given above for the organic additives typically used in inks, such organic passivated surfaces are contraindicated in the fabrication of native Group IV thin films.
[0035] Accordingly, there is a substantial challenge to create Group IV semiconductor nanoparticle dispersions and suspensions using only hydrogen-terminated nanoparticles and solvents or solutions that are substantially oxygen-free, and leave no organic residue in embodiments of fabricated Group IV thin films disclosed herein.
[0036] Interestingly, aromatic hydrocarbon solvents of the general formulas shown below have been found to produce suitable dispersions of Group IV nanoparticles:
[0037] where R 1 , and R 2 for solvent [1] and, R 1 , R 2 and R 3 for solvent [2] are selected from short chain alkyl (C1 through C3) groups; and for solvent [1], if R 1 is selected from halogen, then R 2 is hydrogen.
[0038] Additionally, halogenated hydrocarbons (C1 and C2) have also been demonstrated to produce suitable dispersions of Group IV nanoparticles. For example, inert dispersion solvents contemplated for use include, but are not limited to chloroform, tetrachloroethane, chlorobenzene, xylenes, mesitylene, diethylbenzene, 1,3,5 triethylbenzene (1,3,5 TEB), and combinations thereof.
[0039] In terms of preparation of the dispersions, the use of particle dispersal methods such as sonication, high shear mixers, and high pressure/high shear homogenizers are contemplated for use to facilitate dispersion of the particles in a selected solvent or mixture of solvents. For example, either using a sonication bath or sonication horn has proven to be effective in producing Group IV semiconductor nanoparticle dispersions in the targeted inert oxygen-free solvents and solutions as described above. The quality of the dispersion is defined by the ability of 5 ml of dispersion to filter through a 2.5 mm diameter syringe filter of defined porosity without any significant back pressure. Observations of the filtration properties of embodiments of Group IV semiconductor nanoparticle dispersions suggests that the dispersions may have populations of colloidal particles ranging from individual particles to discrete clusters of particles of different size distributions. Typically, 2.5 mm diameter syringe filters having porosity of 0.45 micron, 1.2 micron, and 5 micron filters have been used. The ability of a dispersion to filter through a smaller pore size indicates that the dispersion has populations of smaller-sized particle clusters, which in turn is defined as a better dispersion.
[0040] For example, it has been observed that dispersions of 5 mg/ml of Group IV semiconductor nanoparticles in the inert oxygen-free solvents and solutions described in the above filter well through 1.2 micron filters. Dispersions of Group IV semiconductor nanoparticles in mesitylene and 1,3,5 TEB have at 10 mg/ml also filtered effortlessly through 1.2 micron filters. At 20 mg/ml Group IV semiconductor nanoparticles in the inert oxygen-free solvents and solutions described in the above of, none of the dispersions filtered through 1.2 micron filters. However, dispersions of nanoparticles at 20 mg/ml prepared in either mesitylene or chlorobenzene filtered through 5 micron filters.
[0041] At concentrations at or above about 10 mg/ml, solvent mixtures, or solutions, have been found to be effective for the preparation of suspensions of Group IV semiconductor nanoparticles. In such suspensions, Group IV semiconductor nanoparticles may be taken up in a 3:1 or 4:1 mixture of chloroform/chlorobenzene in a concentration range between about 10 mg/ml to about 30 mg/ml. The suspensions are sonicated in a water bath for between about 5 minutes to about 40 minutes.
[0042] As indicated from process flow chart 100 of FIG. 1 , once a Group IV semiconductor nanoparticle dispersion has been prepared, then as indicated in step 130 the formation of a deposited film of particles, referred to as a porous compact, followed by the fabrication of thin film, as indicated by process step 140 can be done.
[0043] In FIG. 2 , a schematic of these steps is depicted. In this schematic, a porous compact 220 is shown in a cross-sectional view, as a layer on top of a substrate 210 , which may be selected from a variety of materials. For example, substrate materials may be selected from silicon dioxide-based substrates, either with or without a thin film of a material on the surface in contact with the porous compact 220 . The silicon dioxide-based substrates include, but are not limited by, quartz, and glasses, such as soda lime and borosilicate glasses. The deposited thin films may be from selected from conductive materials, such as molybdenum, titanium, nickel, and platinum. Alternatively, the deposited thin films may be from selected from dielectric materials, such as silicon nitride or alumina. For some embodiments of Group IV semiconductor thin films, stainless steel is the substrate of choice. Finally, for other embodiments of Group IV semiconductor thin films, the substrate may be selected from heat-durable polymers, such as polyimides and aromatic fluorene-containing polyarylates, which are examples of polymers having glass transition temperatures above about 300° C.
[0044] From the porous compact 220 , embodiments of thin films 230 , 240 are fabricated in an inert environment as previously described, as indicated schematically by enclosure 250 . The porous compact 220 is formed from depositing a dispersion of Group IV semiconductor nanoparticles onto a substrate 220 . It is contemplated that a variety of spraying, dipping, brushing, casting, and printing technologies could be used for taking formulations of Group IV semiconductor inks and depositing a porous compact 220 .
[0045] Embodiments of formulations of Group IV semiconductor inks depend on the requirements of the various deposition means, which in turn may have an impact on the characteristics of the deposited porous compact. Finally the characteristics of the thin film fabricated (e.g., 230 , 240 ) are influenced by the deposited porous compact 220 . For example, a thin porous compact with significant variation in film thickness is likely to result in a thin film having significant variation in film thickness. Therefore, the selection of a deposition technology is guided by what targeted characteristics of the deposited porous compact, and hence targeted characteristics in the final fabricated thin film. Some considerations for choosing a deposition technology include, but are not limited to, desired final thin film properties, such as thickness, surface roughness, the amount of material used, and the throughput of the deposition process.
[0046] FIG. 3A and FIG. 3B show cross-sections of scanning electron micrographs (SEMs) that exemplify the impact of deposition on characteristics of porous compacts formed by comparing two different deposition methods, using formulations of silicon nanoparticles optimized for the deposition method. The substrate used in these examples, and all examples shown subsequently, is quartz. The porous compacts are delineated between the hatched lines, and shown at higher resolution in the inserts. In FIG. 3A , the cross-sectional area of a porous compact prepared from a 1 mg/ml solution of silicon nanoparticles about 8.0 nm in diameter using drop casting. As can be seen from the porous compact, which appear grainy in nature, and from the insert, which is twice the resolution, individual particles that are packed together are apparent. In FIG. 3B , a 20 mg/ml solution of silicon nanoparticles of about 8.0 nm in diameter was prepared in a solution of chloroform/chlorobenzene (4:1), and spin cast 1000 rpm for a minute. In comparison to the drop cast porous compact of FIG. 3A , the spin cast porous compact of FIG. 3B is more tightly packed, which can is more clearly visible in comparing the inserts at higher resolution.
[0047] In another aspect of what is depicted in FIG. 2 , different processing conditions used in the fabrication of a thin film from a porous compact may produce characteristically different thin films. For example, in FIG. 2 , a porous compact 220 under certain conditions of heat and pressure may produce a sinter 230 of more compact nature, but still having significant porosity. If the processing conditions are increased, then a densified thin film 240 is formed. In some embodiments, the processing may significantly reduce pore size, while in still other embodiments, the conditions may be selected so that pores are either greatly reduced or eliminated. Regarding pore structure, in some embodiments of sinters such as 230 , the pores may be in fluid communication with other pores within the film, so that there is a network of pores through the film, and therefore in fluid communication with the external environment. As a film becomes a densified film 240 , the pores may become occluded, such that they are no longer in fluid communication with other pores or the external environment. Finally, in embodiments of the most highly densified films 240 , the pore structure is substantially eliminated.
[0048] With respect to the fabrication step 140 of FIG. 1 , it is contemplated that processing variables impacting embodiments of Group IV semiconductor thin films include, but are not limited to the temperature, pressure, the type of inert environment used, as well as Group IV semiconductor nanoparticle properties, such as size and composition.
[0049] Examples of the impact of processing temperature on the formation of a Group IV semiconductor thin film from a porous compact are shown in FIGS. 4A and 4B and FIG. 6 . In these figures, SEMs of the cross-sections of representative porous compacts are shown between the hatched lines in comparison to the cross-sections of embodiments of Group IV semiconductor thin films formed under different sintering temperatures.
[0050] In FIG. 4A , a porous compact shown between the hatched lines was formed from a 20 mg/ml solution of silicon nanoparticles of about 8.0 nm in diameter was prepared in a solution of chloroform/chlorobenzene (4:1), and spin cast 1000 rpm for a minute. The film produced is about 2 microns, as can be seen from the scale. In FIG. 4B embodiments of the thin film shown between the hatched lines formed from the porous compact was fabricated in vacuo at about 10 −6 Torr and at temperatures between about 400° C. to about 700° C. for not more than about 15 minutes. The thin film so produced has compacted from about 2 microns to about 500 nm, or by a factor of four.
[0051] Since the behavior and properties of Group IV semiconductor nanoparticles are not thoroughly understood, terminology used for the processing of more macroscopic materials may not eventually be held to be correct when applied to such nanoparticles. In that regard, though not limited by such description, embodiments of the thin film of FIG. 4B have the appearance of a sinter, and as will be discussed in more detail subsequently, are being processed well below the melting point of bulk material. In a sinter, three major changes are noted versus a porous compact. These changes include an increase in grain size, a change in pore shape, and a change in pore size and number, generally leading to an increase in the density of a sinter. In comparison of the porous compact of FIG. 4A to the thin film of FIG. 4B , it can be seen that the grain boundaries have increased, which is more clearly seen by comparison of the inserts for FIGS. 4A and 4B , at higher resolution. That the pore size and number has changed is inferred from the compaction by a factor or four.
[0052] Additionally, the grain size increase can be monitored using x-ray diffraction (XRD). In FIG. 5 , x-ray diffraction XRD data for an embodiment of a sintered thin film, like that of FIG. 4B , is shown in comparison to the silicon nanoparticle starting material. X-ray glancing angle measurements were performed on a Philips MRD diffractometer with copper anode source operated at 45 kV and 40 mA. The incident optics used for the measurement was an x-ray mirror to provide parallel beam, a ½° divergence slit, an automatic nickel attenuator with an attenuation factor of 171 and a 10 mm incident beam mask. The receiving optic used was a 0.27° parallel beam collimator slit and a 0.04 radians Soller slit. A glancing-angle scan with incident angle ω=1° was performed to get enough intensity. The x-ray diffraction peaks were fit using symmetric Pearson VII profile.
[0053] Qualitatively, from FIG. 5 , it is noteworthy to compare the peak widths for sintered thin film in comparison to the silicon nanoparticle starting material, since the narrower band of the sintered thin film is an indication that the grain size has increased. From these data, it is possible to estimate the grain size based on Scherrer equation after deconvoluting the broadened peaks. By using this data reduction technique, it has been estimated that the grain growth is approximately at least 10 times greater for the sintered thin film than for the silicon nanoparticle starting material.
[0054] In FIG. 6 , a porous compact similar to that of FIG. 4A was prepared, but was spin cast at 4000 rpm for a minute. The resulting film thickness was about 400 nm. The porous compact so formed may be processed in vacuo at about 10 −6 Torr and at temperatures between about 700° C. to about 900° C. for not more than about 15 minutes to form embodiments of a densified thin film, such as that exemplified by the thin film of FIG. 6 . The thin film so produced has compacted from about to about 185 nm, or by a factor of about two. In comparing the densified thin film of FIG. 6 to the sintered thin film of FIG. 4B at comparable resolution, it can be seen that the densified thin film of FIG. 6 , is significantly compacted, and if pore structure exists, it is likely that such pores are highly reduced in number and size.
[0055] Regarding a comparison of electrical properties of the three types of thin films as discussed above, in FIG. 7 , a plot of the dark current versus voltage, which is logarithmic in current, displays such a comparison. In FIG. 7 , the response for a porous compact, (e.g., FIG. 3B ), a sintered thin film (e.g., FIG. 4B ), and a densified thin film (e.g., FIG. 6 ) is shown. First, it is noted that the response increases continuously over the range of applied voltage measured, which demonstrates that the films are well formed, so that there is a continuous electrical path. It is evident in from viewing the graph that the response of the porous compact is about a full decade lower in response than the sinter of FIG. 4B , and about five orders of magnitude ten less than the densified thin film of FIG. 6 . The four orders of magnitude ten increase in current of the densified thin film of FIG. 6 over the thin film of FIG. 4B over the range of the voltage applied signifies that a significant change in the nature of the densified film. Additionally, absorbance spectra taken of embodiments of thin films such as those exemplified by FIG. 4B and FIG. 6 suggest that the silicon thin film formed is a mixed phase of nanocrystallite and amorphous silicon.
[0056] It should be noted that the temperatures used to form the embodiment of the sinter of FIG. 4B and embodiments of the densified thin film of FIG. 6 are significantly lower than the melting point of bulk silicon, which occurs at about 1400° C. For the embodiments of thin films contemplated having a thickness of about 150 nm to about 3 microns, such a reduction in the processing temperature enables significant advantages in the selection of substrates, as well as for the scaling of the process. For example, it is contemplated that a flexible substrate, such as stainless steel or heat-durable polymer, would be well-suited to low-temperature processes, which flexible substrates enable high-volume web processing thereby.
[0057] In addition to the use of temperature, the use of pressure in combination with temperature is contemplated; particularly in the range of about 3000 to about 7000 psig. In FIG. 8 , a SEM showing the cross-section a porous compact prepared as shown in FIG. 4A and subjected to 7000 psig for about five minutes at room temperature. This resulted in the porous compact of initial thickness of about 2 microns to be compacted to about 500 nm in thickness, or by a factor of four, using pressure alone. For embodiments of the most densified thin films, the use of both temperature and pressure is indicated.
[0058] With respect to step 140 of FIG. 1 , concerning fabricating embodiments of Group IV semiconductor thin films in an inert environment, several approaches are considered. In addition to processing in vacuo, as given in the examples above, the Group IV semiconductor thin films may be processed in inert environments using a noble gas or nitrogen, or mixtures thereof. Additionally, to create a reducing atmosphere, 20% by volume of hydrogen may be mixed with the noble gas, or nitrogen, or mixtures thereof. Though as previously discussed, “inert” is not limited in meaning to substantially oxygen free, one metric of an inert environment includes reducing the oxygen content so that the Group IV semiconductor thin films produced have no more than about 10 17 to 10 19 oxygen content per cubic centimeter of Group IV semiconductor thin film.
[0059] Finally, after the fabrication of the Group IV semiconductor thin film is complete, the thin film may be transferred from the inert environment, as shown in FIG. 1 , step 150 . After the fabrication, post-processing steps may be done, such as hydrogenation to create stable hydrogen-terminated Group IV semiconductor thin films. In such a processing step, the thin films would be subjected to a forming gas, which is a volumetric mixture of about 10% to 20% hydrogen in an inert gas, such as a noble gas of nitrogen. The processing temperature for creating hydrogen-terminated Group IV semiconductor thin films is between about 300° C. to about 350° C., for between about 0.2 to about 5 hours.
[0060] Additionally, the Group IV semiconductor nanoparticle starting material introduces variables into the fabrication of Group IV semiconductor thin films, which variables include nanoparticle size and composition. In order to introduce embodiments thin films prepared using Group IV semiconductor nanoparticles of various sizes and compositions, some perspective over the art is indicated.
[0061] In previous studies, the reduction of melting point for semiconductor nanoparticles has been the focus of theoretical, as well as experimental studies (see for example Goldstein, U.S. Pat. No. 5,576,248). In the ionic binary or higher order semiconductor nanoparticles, such as cadmium sulfide, gallium arsenide, and the like, disproportionation involving the loss of one species from a nanoparticle surface drives the melting process for of such semiconductor nanoparticles. However, this cannot explain the melting properties of the Group IV semiconductor nanoparticles, since the bonding of atoms in such nanoparticles is covalent in nature.
[0062] While the reduced melting as a function of Group IV nanoparticle diameter has been reported, it has been done so as general conjecture based on theory of ionic semiconductors, or fitted to experiments done using polydisperse Group IV nanocrystals. Such conjectures and studies focus on melting, which is a familiar property of a bulk material. Though melting is certainly a property of nanoparticle materials, given the unique properties of such materials, then unique behavior not previously reported for comparable bulk materials is likely to be discovered for this novel class of materials.
[0063] For example, the term “fusion” implies melting, the term “sintering” implies the diffusion of species across grain boundaries, and the term “agglomeration” implies formation of bonds between reactive Group IV semiconductor atoms at the surface. Given the formation of densified silicon thin films of about 200 nm to 3 microns in thickness, formed between about 400° C. to 900° C. from silicon nanoparticles of about 8 nm in diameter; it is unclear at this time what mechanisms may be involved. This is especially the case, given that the conventional wisdom for Group IV semiconductor nanoparticles holds that layers of particles greater than 3-4 particles deep would act like bulk silicon, and therefore melt at about 1400° C. For perspective, for a thin film of 150 nm to about 3 microns fabricated using Group IV nanoparticles in the range of about 1 nm and 10 nm, this would represent embodiments of Group IV semiconductor particles in excess of 15 to about 3000 nanoparticles deep, given the compaction that results in the processing of a porous compact to a thin film, as discussed previously. Though invention does not require an understanding of mechanism or theory, it is desirable to clarify the complexities that exist in the art concerning the properties of Group IV semiconductor nanoparticles, so as to highlight the uniqueness of embodiments of thin films disclosed herein.
[0064] Turning attention to FIG. 9A and FIG. 9B , what is shown in these figures are plan views of germanium nanoparticles of about 4 nm prepared as a porous compact ( FIG. 9A ), and as a sintered thin film ( FIG. 9B ). The 4 nm particles were formulated as a 30 mg/ml suspension in chloroform/chlorobenzene (3:1), which was sonicated in a sonication bath for about 20 minutes. Porous compacts were prepared using spin casting at 1000 rpm for about 1 minute. Embodiments of the thin film shown in FIG. 8B were prepared from a porous compact so prepared by heating the porous compact in an inert environment at about 300° C. for up to about 15 minutes.
[0065] In comparison of the plan view of the germanium porous compact ( FIG. 9A ) to that of the plan view of the thin film post processing at 300° C. ( FIG. 9B ), it can be seen that significant growth in grain boundary has occurred in the germanium thin film. It is further evident that the germanium thin film produced at 300° C. from the germanium nanoparticles is comparable to that of silicon thin films fabricated from silicon nanoparticles at about 400° C. to about 700° C. Further, the processing temperature of 300° C. for the germanium nanoparticles is significantly below that of the melting point of bulk germanium, which is about 937° C. As such, for embodiments of Group IV semiconductor thin films utilizing germanium nanoparticles, core/shell particles containing germanium, and alloys of Group IV semiconductor nanoparticles, the processing temperature is expected to be lowered still further than for the silicon thin films fabricated from the silicon nanoparticles as previously described herein.
[0066] As will be clear to practitioners of the art, families of Group IV semiconductor thin films can be created by utilizing combinations of particle size, and particle type, in conjunction with variations of processing conditions, such as, but not limited to, temperature and pressure. For example, embodiments of thin films may be created by processing combinations of particles of the same Group IV semiconductor material of different sizes, where a certain proportion of the particles have different phase transition properties than do others. As another example, embodiments of thin films of a combination of Group IV semiconductor materials of the same or different size may be fabricated, where a certain proportion of nanoparticles having different phase transition properties than other nanoparticles are used. In still another example, embodiments of Group IV semiconductor thin films are formed from alloys or core/shell structures of silicon, germanium and alpha-tin. In some embodiments of this family, the nanoparticles created as alloys or core/shell structures may be mixed with Group IV semiconductor nanoparticles of a single material. Finally, families of Group IV semiconductor thin films may be created by selection of composition, size, and crystallinity of the nanoparticle starting material. In some embodiments of this family of thin films, in addition to composition and size as variables, particles that are amorphous in nature may be mixed with particles that are crystalline in nature.
[0067] While the principles of this invention have been described in connection with exemplary embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention. What has been disclosed herein has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit what is disclosed to the precise forms described. Many modifications and variations will be apparent to the practitioner skilled in the art. What is disclosed was chosen and described in order to best explain the principles and practical application of the disclosed embodiments of the art described, thereby enabling others skilled in the art to understand the various embodiments and various modifications that are suited to the particular use contemplated. It is intended that the scope of what is disclosed be defined by the following claims and their equivalence.
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Native Group IV semiconductor thin films formed from coating substrates using formulations of Group IV nanoparticles are described. Such native Group IV semiconductor thin films leverage the vast historical knowledge of Group IV semiconductor materials and at the same time exploit the advantages of Group IV semiconductor nanoparticles for producing novel thin films which may be readily integrated into a number of devices.
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FIELD OF THE INVENTION
[0001] The present invention relates to improved wire and line attachment mechanisms for plant support and trellis systems for supporting plant growth, and methods of using the same. The attachment mechanisms may be quickly and efficiently installed to decrease the time and cost of installing the plant support or trellis system.
DISCUSSION OF THE BACKGROUND
[0002] Because of the temporary nature of the growing season in some areas, requiring the rotation or alternation of crops, it is advantageous to have vertical growth supporting structures (e.g., trellis systems) that are easy to assemble, disassemble, store, and move. There are many structures and systems for the supporting the vertical growth of plants. Various combinations of poles, slats, cords and wires, as well as metal, concrete and wood structures are currently in use.
[0003] However, systems that are currently used to maintain vertical growth of certain kinds of plants (e.g., grapes, bell peppers, tomatoes, etc.) have drawbacks that have not been addressed. These systems are often difficult and time consuming to assemble. Typically, such systems include a single central set of posts with wires strung therebetween on which the plants may be trellised and trained. The wires are typically wound around each post and then tied or cinched to an end post. Both the installation and disassembly of such central post and wire systems is very labor-intensive and expensive, especially in a large growing operation.
[0004] While there are existing designs that are functional to support vertical plant growth, many have disadvantages that reduce their usefulness by being complicated, cumbersome, and difficult to assemble and disassemble. It is therefore desirable to provide devices and systems for installing plant support systems that can be more efficiently installed, removed, and stored.
SUMMARY OF THE INVENTION
[0005] The present invention provides improved wire and line attachment mechanisms (wire loop devices) that offer significant improvements in efficiency with regard to assembling and disassembling a plant growth supporting system (e.g., a trellis system), and methods of using the same. The wire loop device may quickly and easily attached wire or other support lines to a support pole or stake (e.g., an anchoring pole at the end of a crop row) and provide a means of tightening the wire or support line once the attachment mechanism is engaged with the support pole or stake.
[0006] The wire loop devices may each include a sturdy wire loop having a circular or approximately circular portion for engagement with a support pole or stake, and an anchoring portion for engagement with a wire strainer bracket. The wire loop may be made from heavy metal wire or composite material. The anchoring portions of the wire basket may each include angled or flared 90° ends or elbows (having a bend therein at an angle of about 40° to about 100°, e.g., 90° or any other angle or range of angles therein) that engage with sidewalls of the wire strainer bracket to anchor the wire loop to the wire strainer bracket. The connection between the anchoring portions of the wire loop and the strainer bracket may be sufficiently strong to prevent the wire loop from being ripped out of the wire strainer bracket under high tension.
[0007] The wire loop devices may also include a wire or line strainer for attaching to and straining trellis wire or other support lines. The strainer may include a ratcheting spool to which the wire may attached, and the spool may be cranked to tighten the attached wire or line to the desired tension without the wire or line unwinding or slipping. The ratcheting spool may have an attachment point or structure (e.g., a tang) thereon for engaging a tool (e.g., a wrench) for cranking the spool.
[0008] The combined structures of the wire loop and the wire strainer bracket can be attached to a high tensile strength support line (e.g., a trellis wire or other high tensile strength line) and easily slipped over the stake or post for anchoring the support line. The support line may then be tightened by cranking the spool. Once the support line is tightened, friction between the wire basket and the pole or stake may keep the wire basket in place on the pole or loop. The wire basket may optionally have a textured or roughened surface to increase friction between it and the post or stake.
[0009] The wire loop devices may be operable to tighten and hold the high tensile strength support line (e.g., high tensile strength plastic or polymer line, metal wire, composite line, etc.) that may be stretched along a crop row at high tension. The support line may be stretched between end posts that are positioned at opposite ends of a crop row (e.g., hundreds of feet apart). The support line may be attached at one end to the wire loop device and the wire loop device may be slipped over a first end post. The opposite end of the support line may be statically attached to the other end post. The support line may then be ratcheted onto the spool of the wire loop device such that it is sufficiently taut to support the vertical growth of plants in the crop row. Thus, the wire loop devices of the present invention may be used to support and/or train plants along an entire crop row.
[0010] The present invention offers efficiencies in the installation of vertical growth systems over conventional systems. The wire loop devices of the present invention may be used to install up a vertical growth support system (e.g., a trellis system) in a crop row quickly and efficiently without the need to wind and tighten the support line around individual poles or stakes. Thus, the present invention saves a substantial amount of time and man-hours in comparison to conventional support devices and techniques used in trellising systems.
[0011] During installation of support lines, the support lines may be laid out along the entire crop row between a first end post at one end of the crop row and a second end post at the other end of the crop row. For example, the support lines can be spooled out from a tractor, truck, or other vehicle quickly and efficiently. The end posts may be sufficiently stably anchored in the ground to withstand the high tensile stress that will be applied to them by the support line (e.g., the end posts may be driven into the ground several feet, may be angled away from the crop row, and/or may have concrete poured around the buried and base portions thereof, etc.). The first ends of the support lines may be tied, tacked, or otherwise statically attached to the first end post, and the opposite ends of the tension lines may be attached to a wire loop device of the present invention.
[0012] The wire loop portion of each wire loop device may be simply passed over the pole and each wire loop device may be placed a different vertical distance along the pole to space out the tension lines. Each support line may be attached (e.g., threaded through) the cinching mechanism in the wire loop device (e.g., a ratcheting crank) such that the support lines may be tightened to a preferred tension after the wire loop device is engaged with the second end post. Without limiting the invention, the support lines may be made from a material that allows the application of tension in a range of about 20 lbs. to about 2000 lbs. (e.g., about 50 to about 1500 lbs., about 100 to about 1000 lbs., or any other value or range of values therein). For example, and without limitation, the support lines may be made from a high-tensile strength wire (e.g., high strength, high tensile steel, etc.), polymer material (e.g., aromatic polyamide fibers, PBO, etc.), composite material, etc.
[0013] Prior to applying high tension to the support lines, the support lines may be attached to trellis structures or other support structures installed along crop row by clips or other fasteners (e.g., wire ties, zip ties, etc.) or may simply be popped into open loop structures (e.g., open rings or slots) in the support structures along the crop row. The support lines may be partially tightened prior to being attached to the support structures along the crop rows. After the support lines are attached to the support structures, the support lines may be tightened to full tension. Once the predetermined desired tension is established the installation of the plant support or trellis system may be complete.
[0014] The present wire loop devices may also be used in plant support systems that utilize multiple sets or groups of support lines. For example, and without limitation, some plant support systems may use laterally spaced support lines that flank or run parallel to a crop row to support vertical growth of the crop plants and/or to prevent or limit low-lying lateral crop growth along the ground. Such systems may have two laterally spaced sets of terminal poles that flank each end of the crop row. The wire loop devices of the present invention may be used to connect support lines to such lateral terminal poles and apply tension to the support lines. The wire loop devices of the present invention are not limited to the applications discussed herein and other applications and uses of the wire loop devices are within the scope of the present invention.
[0015] The advantages of the present invention are further illustrated by the embodiments described herein. It is to be understood that there are several variations in the trellis system, and that the embodiments described herein are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed.
[0016] In some embodiments, and without limitation, the present invention relates to an attachment device that includes a wire loop having a loop portion and two attachment portions, the loop portion having a circular open loop shape for engaging an anchoring post, and the two attachment portions each having an extension portion and an anchor, the anchor having an angle in a range of about 40° to about 100° relative to the extension portion; a wire strainer bracket having first and second sidewalls and a rear wall connecting the first and second sidewalls, where the two attachment portions pass through a passage in the rear wall and each of the anchors engage with one of the sidewalls; and a spool for attaching and tightening a support line for supporting vertical growth of a plant. The wire loop may include a heavy gage metal wire that can maintain its shape and engagement with the sidewalls of the strainer bracket under high tension. The wire loop may withstand the support line being tightened to a tension in a range of 20 lbs. to about 2000 lbs. (e.g., about 50 to about 1500 lbs., about 100 to about 1000 lbs., or any other value or range of values therein). The anchor may have an angle of about 90° relative to the extension portion. The engagement of the anchors of the wire loop with the sidewalls may be sufficiently strong to prevent pullout of the anchors under tension in the above range. The wire strainer may include a first hole in the first sidewall and a second hole in the second sidewall, where the anchors engage with the first and second holes. The wire loop may be made from a rigid metal or composite material. The passage in the rear wall may include two lateral slots, each for receiving the extension portion of one of the attachment portions of the wire loop. The lateral slots may prevent vertical or outward movement of the attachment portions of the wire loop relative to said wire strainer bracket.
[0017] The spool of the attachment device may include a gear that may function as a portion of a ratchet mechanism. The ratchet mechanism may further include a pawl, such as a spring attached to the wire strainer bracket, where the spring engages with the teeth of the gear.
[0018] In some embodiments, and without limitation, the present invention relates to an attachment device for connecting a plant support line to an end post to thereby suspend the support line over a crop row, the attachment device including an open wire loop structure having a substantially circular portion for engaging with the end post, and first and second anchoring portions having laterally flared ends; and a wire strainer bracket for applying tension to the support line, the wire strainer bracket having two lateral sidewalls, each sidewall having an anchor receiving hole, and each anchor receiving hole having one of the first and second flared ends inserted therein, the wire strainer bracket further including a rear wall connecting the two lateral sidewalls, the rear wall having a passage with first and second lateral slots, the lateral slots having a width slightly larger than a diameter of the anchoring portions of the open wire loop structure and the first anchoring portion is positioned within the first lateral slot and the second anchoring portion is positioned within the second lateral slot, where the connection between the open wire loop structure and the wire strainer bracket is sufficiently strong to withstand separation when the strainer bracket applies a tension to the support line of up to 2000 lbs.
[0019] In some embodiments, and without limitation, the present invention relates to a method of installing a plant support system that includes laying out a plurality of support lines along a crop row, attaching a first end of each of said plurality of support lines to an attachment device as described herein, attaching a second end of each of the plurality of support lines to an first end post, engaging the wire loops of each of the attachment devices with a second end post, and applying a predetermined tension to each of the support lines using the attachment devices. Such embodiments may further include installing in the ground a plurality of vertical support structures along the crop row between the first and second end posts, each of the plurality of vertical support structures having a plurality of support line receivers thereon, the support line receivers being open loop structures with which the support lines may engaged without having to longitudinally thread the support lines through the support line receivers.
[0020] In some embodiments, and without limitation, the present invention relates to a method of installing a plant growth support system, including laying out a plurality of retaining lines along a crop row; attaching a first end of each of the plurality of support lines to a first terminal post at a first end of said crop row; individually attaching a second end of each of the plurality of support lines to one of a plurality of wire loop devices; placing the wire loop devices on a second terminal post at a second end of the crop row; and tightening the support lines using the wire loop devices to tension in a range of about 20 lbs. to about 2000 lbs.
[0021] It is an object of the present invention to provide a tensioning device for trellis or plant support systems that allows the system to be quickly and efficiently installed for growing trellised crops.
[0022] It is also an object of the present invention to provide a tensioning device that can be quickly slipped over an anchoring pole at the end of a crop row.
[0023] It is also an object of the present invention to provide a tensioning device that can apply high tension to trellis wires or other plant support lines without failure of the tensioning device.
[0024] It is also an object of the present invention to provide a method of installing trellis wires or other support lines on a trellis and support system that reduces the installation time of the trellis or support system.
[0025] Additional aspects and objects of the invention will be apparent from the detailed descriptions and the claims herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 is a perspective view of an attachment device according to an embodiment of the present invention.
[0027] FIG. 2 is a perspective view of a wire strainer bracket of an attachment device according to an embodiment of the present invention.
[0028] FIG. 3A is an overhead view of a wire strainer bracket of an attachment device according to an embodiment of the present invention.
[0029] FIG. 3B is an anterior view of a wire strainer bracket of an attachment device according to an embodiment of the present invention.
[0030] FIG. 4 is a side view of a plant growth system according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0031] Reference will now be made in detail to certain embodiments of the invention, examples of which are illustrated in the accompanying drawings. While the invention will be described in reference to these embodiments, it will be understood that they are not intended to limit the invention. To the contrary, the invention is intended to cover alternatives, modifications, and equivalents that are included within the spirit and scope of the invention as defined by the claims. In the following disclosure, specific details are given to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that the present invention may be practiced without these specific details.
[0032] Referring to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, and referring particularly to FIGS. 1-4 , it is seen that the present invention includes various embodiments of a wire loop tensioning device for connecting to and applying tension to a support line (e.g., a trellis wire). It is also evident in the drawings that the invention includes methods of using the wire loop devices.
[0033] Without limiting the invention, FIG. 1 shows an exemplary embodiment of a wire loop device 100 according to an embodiment of the present invention. Wire loop device 100 includes a wire loop structure 101 which may engage with a support post or stake of a trellis or plant growth support system, and a wire straining bracket assembly 102 . The wire loop structure 101 may include an open circular portion referred to herein as the loop 101 a , as well as extensions 101 b that may be inserted into the wire straining bracket assembly 102 . The extensions 101 b may each have anchors 101 c that may each include angled ends or elbows 101 d (having an angle in a range of about 40° to about 100°, e.g., 90° or any other angle or range of angles therein) that engage with sidewalls of the wire strainer bracket to anchor the wire loop 101 to the wire strainer bracket assembly 102 . The connection between the anchoring portions of the wire loop and the strainer bracket may be sufficiently strong to prevent the wire loop from being ripped out of the wire strainer bracket under high tension.
[0034] The wire loop 101 may be made from strong metal wire or composite material. For example, and without limitation, the wire loop may be made from a high tensile strength steel rod. In some implementations, and without limitation, the wire loop structure may have a partially or wholly textured surface (e.g., without any coating over the metal loop) that increases friction and bite between the wire loop structure and the pole or other structure with which it may be engaged. Such surface textures may include a ground surface (e.g., a non-reflective unidirectional texture), brushed or dull polished surface, satin-polished (special non-reflective finish that may be corrosion resistant in external conditions), etc. Without limiting the invention, the wire loop may have a textured surface having a roughness average (Ra-μm) in a range of about 0.1 to about 1.5 (e.g., about 0.3 to about 1.0, or any value or range of values therein). In further implementations, and without limitation, additional materials may be included in the wire loop structure such as a polymer anti-weathering coating, a high friction polymer coating material to increase the friction between the wire loop and the pole or other structure with which is engaged, etc.
[0035] As shown in FIG. 1 , and without limitation, the strainer bracket assembly 102 may have a U-shaped structure that includes a rear wall 102 a and first and second sidewalls 102 b and 102 c . The rear and side walls may be integrally formed, providing structural strength. The strainer bracket assembly 102 may further include a spool 104 that includes lateral gear wheels 104 a and 104 b . The strainer bracket assembly may also include a spring 105 that engages with one or both of the gear wheels 105 a and 105 b.
[0036] FIG. 2 , without limiting the invention, shows a close-up view of an exemplary strainer bracket assembly 102 to provide a clearer view of the components thereof. The spool 104 and the spring 105 may work together as a ratcheting mechanism. The spring 105 includes two static anchoring portions 105 a and 105 b that may engage with receiving holes in the bracket sidewalls 102 b and 102 c , and an engagement bar 105 c that is operable to engage with the teeth of the gear wheels 104 a and 104 b . The spring may be deformable and resilient such that it is displaced as the spool and gears are turned and resiles into engagement with the teeth of the gears when the gears are in a static position. The spool 104 includes a shank or tang 104 e that may be engaged with a tool (e.g., a socket wrench, a crescent wrench, pliers, etc.) to rotate the spool 104 and tighten a tension line attached to the spool 104 . The spool 104 may include holes 104 d for threading and anchoring tension lines to the spool prior to applying tension to the tension lines.
[0037] FIGS. 3A and 3B , without limiting the invention, show a close-up view of the interconnection of the anchoring portions 101 c of the wire loop 101 and the strainer bracket 102 . The two attachment portions 101 c may pass through an opening 103 in the rear wall 102 a of the strainer bracket. The opening in the rear wall of the strainer bracket may have a specialized shape that allows the attachment portions of the wire loop to passed through the opening and also engage with narrow lateral slots therein. For example, the opening 103 includes lateral slots 103 a and 103 b that have a vertical dimension that is slightly larger than the diameter of the two attachment portions 101 c of the wire loop 101 . The shape of the opening 103 may allow the attachment portions to be squeezed together and passed through the opening 103 , and to then be slotted into the lateral slots 103 a and 103 b after they are passed through the opening 103 . Additionally, the angled portions 101 d of the two attachment portions 101 c may simultaneously be inserted into lateral holes 106 a and 106 b in the lateral walls 102 b and 102 c of the strainer bracket. The combination of the insertion of the angled ends 101 d of the wire loop 101 and the insertion of the attachment portions 101 c into the lateral slots 103 a and 103 b provides a stable connection between the wire loop 101 and the strainer bracket. The interaction of the attachment portions 101 c and the lateral slots 103 a and 103 b prevents the wire loop from shifting or rotating up or down along a vertical plane. Also, the angle of the attachment portions 101 c of the wire loop may be positioned to abut the lateral slots 103 a and 103 b in the rear wall 102 a of the strainer bracket such that as tension is applied to the wire loop 101 , the angle applies pressure against the rear wall 102 a . The pressure between the attachment portions 101 c and the rear wall 102 a and the pressure between the angled portions 101 d and the holes 103 a and 103 b may prevent disformation of the attachment portions 101 c (e.g., straightening of the angled portions 101 d ). Additionally, the wire loop may include a heavy gage metal wire that can maintain its shape and engagement with the sidewalls of the strainer bracket under high tension.
[0038] The wire loop device of the present invention may be used in a crop support system for supporting crop plants (e.g., grapes, bell peppers, tomatoes, flowers, onions, garlic, peas, etc.) using high tension support lines. One advantage of using the wire loop device of the present invention is that the support lines may be laid out along the entire crop row and attached quickly and efficiently to end poles or posts at each end of a crop row, without the need to tie each of the support lines to each of a multitude of trellises or other support structures between the end posts. The present wire loop device allow the retaining lines to be suspended at high tension along the crop row without the need for additional support between the end posts. In some embodiments, and without limitation, the high tension support lines may be engaged with trellises or other support structures between the end posts. The trellises or other support structures may have support line receivers that may be open ring or slot structures that allow the support lines to be placed within the receivers without having to be threaded through the receiver longitudinally. The open structure of the retainers allows the support lines to be laid out along the crop row and engaged with the end poles before being inserted into the support line receivers. The avoidance of having to thread the ends of the support lines through the support line receivers saves a substantial amount of labor and time in the process of installing the crop support system. Once the support lines are routed through the support line receivers, the support lines may be tightened by the wire loop devices to a preferred tension thereby providing scaffolding upon which the plants in the crop row may be supported during growth.
[0039] Without limiting the invention, FIG. 4 shows a view of an exemplary crop support system 400 that includes multiple wire loop devices 100 of the present invention. The support lines 200 (e.g., high tension lines) may be strung between anchoring end posts 300 and 301 (the breaks shown in the support lines 200 and the ground indicate that the length of the support lines and the distance between the end posts 300 and 301 may vary). The support lines 200 may be attached at one end by tying or mechanical anchoring to an end post 301 at a first end of a crop row. Mechanical couplers 350 may be used to connect the support lines to the end post 301 . Mechanical couplers 350 may include one or more devices to resist slippage or shearing of the high tensile line (e.g., a crimp sleeve for receiving the support line, etc.). The other end of the support lines 200 may each be attached to a spool of one of the wire loop devices 100 , as described herein. The wire loop of the wire loop device 100 may then be engaged with the end post 300 at a second end of the crop row.
[0040] Once the attachment devices are engaged with the anchoring pole, the ratcheting mechanism made up of the spool 104 and the spring 105 may be ratcheted to tighten the retaining lines 200 . The retaining lines may be made from a material that allows the application of tension in a range of about 20 lbs. to about 2000 lbs. (e.g., about 100 to about 1000 lbs., or any value or range of values therein). For example, and without limitation, the retaining lines may be made from a high-tensile strength wire (e.g., high strength, high tensile steel, etc.), polymer material (e.g., aromatic polyamide fibers, PBO, etc.), composite material, etc.
[0041] The wire loop devices 100 may tighten the support lines 200 sufficiently to suspend the support lines with substantially no sag when crop plants are attached to and/or rest on the support lines 200 . The attachment devices may be tightened using a manual or motorized cranking tool or other leverage device (e.g., a socket wrench, a crescent wrench, pliers, an electric driver, etc.; not shown) to apply the preferred tension to the support lines.
[0042] The tension applied to the support lines 200 may require that the end posts 300 and 301 be strongly secured, so that they are not uprooted and do not collapse toward one another. The end posts may be driven several feet into the ground (e.g., to a depth in a range of about two feet to about five feet, or any value or range of values therein) and may be angled away from the crop row in order to withstand the tension applied to the support lines 200 . The end posts 300 and 301 may also include features that prevent them from being uprooted themselves. For example, and without limitation, the end posts may include one or more plates along the buried portion thereof that provide more surface area against the soil. For example, and without limitation, the end posts may be tee posts with foot plates attached thereto.
[0043] In some embodiments, a plurality of trellises or other vertical support structures may be set up in the crop row and spaced at regular or varying distances along the crop row. For example, and without limitation, the vertical support structures may be spaced apart by a distance in a range of about 10 feet to about 40 feet (e.g., about 15 to about 30 feet, about 20 to about 25 feet, or any value or range of values therein). The vertical support structures may have one or more support line receivers (e.g., clips, rings, etc.) vertically spaced to each engage support lines at different heights from the ground. The support line receivers may have one or more incomplete or open rings or loops through which the support lines can be strung. Once the support lines are routed through the support line receivers, the retaining lines may be tightened by the wire loop devices to a preferred tension thereby providing scaffolding upon which the plants in the crop row may be supported during growth. The support lines may be strung through the support line receivers to help to maintain the positions of the support lines against forces applied by the crop plants as they grow. However, it is to be understood that the tension in the support lines may be sufficient to support the crop plants without the addition of vertical support structures, such as trellises.
[0044] The present invention provides a plant growth support system (e.g., a trellis system) that may be laid out in a more efficient way than conventional support systems, while still being structurally sound. According to methods of the present invention, the support lines may be laid out along an entire crop row, attached to the end posts, and tightened to a high tension without the need for attachment to an intervening structure. Sufficient tension may be applied to the support lines to enable the support lines to support the vertical growth of the cops planted in the crop row.
[0045] In other embodiments, and without limitation, the support system may include vertical support structures between the end posts, and the support lines may be laid out along the entire crop row prior to, during, or after the installation of the vertical support structures. For example, the support lines may be spooled out along the crop row from a tractor, truck, or other vehicle quickly and efficiently without having to thread the ends of the support lines through closed-loop structures on a trellis or support structure or having to wrap tie the line around the trellis or support structure. The vertical support structures may be driven into the ground either before or after the support lines are laid out. The end posts may be present at each end of the crop row to provide an anchor to the high tension support lines.
[0046] Once the vertical support structures are in position, the support lines can be statically attached to a first end post at one end thereof and to a wire loop device of the present invention at the other end thereof. The wire loop devices may then be slipped onto and engaged with the adjacent end post and tension may then be applied to the support lines by cranking the ratcheting mechanisms on each of the wire loop devices.
[0047] Prior to tightening the support lines to the preferred tension, the lines may be placed into the support line receivers on the vertical support structures, which may aid in maintaining the position of the support lines along the crop row. Once the support lines are positioned in the support line receivers, the support lines may be tightened to the desired (e.g., predetermined) tension to establish the high tension support lines in a sturdy and weight-bearing condition. Once the desired tension is established the installation of the support system may be complete.
[0048] With the support system installed and the support lines tightened, crop plants may be grown and trained (e.g., manually placed on the support lines and vertical support frames) over the growing season so that the plants are maintained in a vertical posture.
[0049] In further embodiments, the design of the plant growth support system of the present invention may reduce the number of vertical support structures (trellises) that are used in conventional support systems. The high-tension support lines may provide added structural support that allows for relatively large gaps between adjacent vertical support structures. For example, the vertical support structures may be spaced apart by a distance in a range of about 10 feet to about 100 feet (e.g., about 20 feet to about 80 feet, or any other value or range of values therein). Also, the vertical support structures may not need to be inserted into the soil as deeply as trellis stakes or other support structures of conventional plant support systems. The relatively shallow depth to which they are inserted may allow them to be inserted into the soil quickly. For example, and without limitation, the vertical support structures may be installed quickly with only a mallet or other driving tool.
[0050] The present invention provides an attachment mechanism for a support system for vertical plant growth and method of installing the same that requires less time to assemble than conventional systems, without sacrificing the structural strength and integrity. It is to be understood that here are several variations in the attachment mechanisms, and that 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 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. It is intended that the scope of the invention be defined by the claims appended hereto and their equivalents.
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The present invention provides improved attachment devices fort support lines in plant growth support systems (e.g., trellis systems) and methods of using the same, and offers significant improvements efficiency with regard to assembling and disassembling the support systems for plant and crop growth. The attachment devices may be advantageously used for various vine and low-lying plants (e.g., grapes, tomatoes, etc.) that can be grown in a trellis system or other vertical growth support system. The anchoring devices may include a wire loop for slipping over an end post and a wire strainer bracket attached to the wire loop.
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CROSS REFERENCE TO RELATED APPLICATION
[0001] This claims the benefit of U.S. Provisional Application Ser. No. 62/118 026, filed Feb. 19, 2015, which is incorporated herein by reference in its entirety.
FIELD OF THE INVENTION
[0002] This invention relates to recreational vehicles, and more particularly to a clothes dryer used with a recreational vehicle or the like.
BACKGROUND OF THE INVENTION
[0003] When traveling, it is sometimes difficult to find an easy way to dry wet clothes. A new and easy manner of drying wet clothes is therefore desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] One or more embodiments of the present invention are illustrated by way of example and should not be construed as being limited to the specific embodiments depicted in the accompanying drawings, in which like reference numerals indicate similar elements.
[0005] FIG. 1 is a perspective view of a clothes dryer of the present invention in a deployed position on a ladder of a vehicle.
[0006] FIG. 2 is a perspective view of the clothes dryer of the present invention in a storage position.
[0007] FIG. 3 is an exploded perspective view of the clothes dryer of the present invention.
[0008] FIG. 4 is a rear side perspective view of the clothes dryer connected to the ladder of the vehicle.
[0009] FIG. 5 is a perspective view of the clothes dryer of the present invention in a deployed position on a vertical support surface.
[0010] The specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting.
DETAILED DESCRIPTION
[0011] For purposes of description herein, the terms “top,” “bottom,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as orientated in FIG. 3 . However, it is to be understood that the invention may assume various alternative orientations (e.g., the elements described as being on the left can be on the right and vice-versa), except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.
[0012] FIG. 1 illustrates a recreational vehicle 10 having a ladder 12 thereon. An embodiment of a clothes dryer 14 is connected to the ladder 12 . The clothes dryer 14 includes a dryer body 16 connected to the ladder 12 and a plurality of dryer arms 18 extending in a cantilever manner from the dryer body 16 . The dryer arms 18 are configured to support clothes thereon for drying the clothes (e.g., shirts, pants, shoes, towels, swim suits, etc.) FIG. 1 illustrated the clothes dryer 14 in a deployed position wherein the dryer arms 18 are separated for easily placing clothes thereon. The dryer arms 18 can be rotated to place the clothes dryer 14 in a storage position as illustrated in FIG. 2 for storage. The clothes dryer 14 can also be removed from connection to the ladder 12 for storage during travel of the recreational vehicle 10 .
[0013] The illustrated dryer body 16 ( FIGS. 1-4 ) is configured to be removably connected to the ladder 12 . The dryer body 16 includes a body bottom half 20 , a body top half 22 and a rotating gripping arm assembly 24 . The dryer arms 18 are secured between the body bottom half 20 and the body top half 22 . The rotating gripping arm assembly 24 is employed to selectively grip a portion of the ladder 12 to removably connect the dryer body 16 to the ladder 12 .
[0014] In the illustrated embodiment, the body bottom half 20 of the dryer body 16 is rigidly connected to the body top half 22 and supports the dryer arms 18 thereon. The body bottom half 20 includes a support platform 26 and a rear wall 28 connected to the support platform 26 . The support platform 26 and the rear wall 28 can be an integral part (as illustrated) or can be formed of separate, but connected parts. Furthermore, the support platform 26 and the rear wall 28 can be made of any material (e.g., metal or plastic). The illustrated support platform 26 includes a support floor surface 30 having an arcuate front edge 32 and a rear edge 34 . The rear edge 34 includes a left portion free edge area 36 and a wall connection portion 38 to the right of the left portion free edge area 36 as illustrated in FIG. 3 . The wall connection portion 38 of the rear edge 34 includes a left side edge area 40 co-linear with the left portion free edge area 36 , a central angled area 42 angled toward the arcuate front edge 32 and a right side edge area 44 that is substantially parallel to the left portion free edge area 36 and the left side edge area 40 . A peripheral skirt 46 extends downward from the periphery of the support floor surface 30 for support. It is contemplated that the body bottom half 20 could include a plurality of crisscrossing supporting struts connected to an inside surface of the peripheral skirt 46 and a bottom surface of the support floor surface 30 for providing strength and rigidity to the support platform 26 . As discussed in more detail below, the support floor surface 30 includes a plurality of openings 48 for accepting a portion of the dryer arms 18 therein and a plurality of tabs 50 adjacent the arcuate front edge 32 for maintaining a position of the dryer arms 18 in the deployed position.
[0015] The illustrated rear wall 28 of the body bottom half 20 connects to the body top half 22 to form the dryer body 16 . The rear wall 28 of the body bottom half 20 is connected to the wall connection portion 38 of the rear edge 34 of the support floor surface 30 . The rear wall 28 includes a left side area 52 extending upwardly perpendicularly from the left side edge area 40 of the rear edge 34 , a central angled area 54 extending upwardly perpendicularly from the central angled area 42 of the rear edge 34 , a right side area 56 extending upwardly perpendicularly from the right side edge area 44 of the rear edge 34 , a right side end wall area 58 extending rearwardly from the right side edge area 44 , a back wall area 60 extending laterally from a rear edge of the right side end wall area 58 and substantially parallel to the left side area 52 and the right side area 56 , and a trapezoidal section 62 connected to the back wall area 60 and the left side area 52 . The trapezoidal section 62 includes a long rear panel 64 , an outside plate 68 connected to the long rear panel 64 and the left side area 52 and an inside plate 70 connected to the long rear panel 64 and the back wall area 60 . The outside plate 68 and the inside plate 70 converge in a direction toward each other from a largest distance at the long rear panel 64 to a smallest distance at the left side area 52 and the back wall area 60 , respectively.
[0016] In the illustrated example, the rear wall 28 accommodates a portion of the rotating gripping arm assembly 24 therein. The right side area 56 of the rear wall 28 includes a front U-shaped slot 72 opening at a top of the right side area 56 . A bottom of the front U-shaped slot 72 defines a gripping arm assembly support surface 74 . The back wall area 60 includes a rear U-shaped slot 76 opening at a top of the back wall area 60 . The rear U-shaped slot 76 is substantially aligned with the front U-shaped slot 72 , although the rear U-shaped slot 76 is slightly wider. The rear U-shaped slot 76 also has a bottom at the gripping arm assembly support surface 74 . A connection wall portion 78 extends between an inside edge 80 of the front U-shaped slot 72 and an inside edge 82 of the rear U-shaped slot 76 . The connection wall portion 78 includes a front angled panel 84 connected to the inside edge 80 of the front U-shaped slot 72 and extending rearwardly and inwardly therefrom, a rear wall panel 86 extending toward the right side area 56 of the rear wall 28 , and a U-shaped panel 88 (as viewed from above) that extends between the front angled panel 84 and the rear wall panel 86 . A top edge of the right side end wall area 58 includes a first slot 90 and a top edge of the curved portion of the U-shaped panel 88 includes a second slot 92 aligned with the first slot 90 . As discussed in more detail below, the first slot 90 and the second slot 92 are configured to accept a pivot rod 94 of the rotating gripping arm assembly 24 . Moreover, a pivot arm 96 of the rotating gripping arm assembly 24 rests on the gripping arm assembly support surface 74 . Furthermore, a pull member 98 of the rotating gripping arm assembly 24 rests on the gripping arm assembly support surface 74 within the U-shaped panel 88 of the connection wall portion 78 .
[0017] The illustrated rear wall 28 connects the body bottom half 20 to the body top half 22 . As illustrated in FIG. 4 , the rear wall 28 includes a ledge 100 adjacent the top of each the left side area 52 , the central angled area 54 , the right side area 56 , the right side end wall area 58 , the back wall area 60 , and the trapezoidal section 62 . The ledge 100 defines a thinner upper rear wall top section 102 . The body top half 22 includes a downwardly depending wall 104 that slides over the thinner upper rear wall top section 102 when the body top half 22 is connected to the body bottom half 20 . The body bottom half 20 includes a first fastener tube 106 located within the trapezoidal section 62 , a second fastener tube 108 connected by struts to the back wall area 60 and the central angled area 54 and a third fastener tube 110 in the gripping arm assembly support surface 74 adjacent the front U-shaped slot 72 in the right side area 56 of the rear wall 28 . Fasteners 112 extend through the body top half 22 and through the first fastener tube 106 , the second fastener tube 108 and the third fastener tube 110 to connected the body bottom half 20 to the body top half 22 . Nuts 114 are screwed onto a bottom of the fasteners 112 to lock the fasteners 112 in position. The fastener 112 extending through the third fastener tube 110 also acts as a pivot for the pivot arm 96 of the rotating gripping arm assembly 24 .
[0018] In the illustrated example, the body top half 22 and the body bottom half 20 capture the dryer arms 18 therebetween. The body top half 22 is substantially a mirror image of the body bottom half 20 , except that the body top half 22 does not include any tabs 50 (although the body top half 22 could include tabs 50 ). Furthermore, the ledge of the rear wall 28 a of the body top half 22 is on the inside instead of on the outside as in the body bottom half 20 as described above to allow the rear wall of the body top half 22 to be received within the body bottom half 20 . Therefore, a bottom edge 116 of the rear wall 28 a of the body top half 22 envelopes a top of the rear wall 28 of the body bottom half 20 . Moreover, the body top half 22 does not include the first slot 90 in the right side end wall area or the second slot in the curved portion of the U-shaped panel as the pivot rod 94 of the rotating gripping arm assembly 24 fully rests within the body bottom half 20 . Furthermore, the top surface of the body top half 22 is flat and support struts are located under the top flat surface.
[0019] The illustrated rotating gripping arm assembly 24 includes the pivot rod 94 , the pivot arm 96 and the pull member 98 . The pivot arm 96 is curved as viewed from above and includes a first end 120 receiving the fastener 112 extending through the third fastener tube 110 . The pivot arm 96 pivots about the fastener 112 extending through the third fastener tube 110 . A concave face 122 of the pivot arm 96 is used to grip the ladder 12 as discussed below. The pivot rod 94 includes a threaded post 124 and a grip 126 connected to an end of the threaded post 124 . The threaded post 124 of the pivot rod 94 extends through the first slot 90 in the rear wall 28 , through a lateral opening 128 in the pivot arm 96 adjacent the first end 120 but rear of the third fastener tube 110 , through the pull member 98 of the rotating gripping arm assembly 24 into a first nut 131 , through the second slot 92 in the rear wall 28 , and into a second nut 132 . The pull member 98 includes a block 134 and a T-shaped projection 136 , with an opening 130 extending through the block 134 and the T-shaped projection 136 . The pull member 98 is located in the U-shaped panel 88 of the connection wall portion 78 . The T-shaped projection 136 is received in a recess 138 in a convex face 140 of the pivot arm 96 . The threaded post 124 of the pivot rod 94 extends through the opening 130 in the pull member 98 . As the grip 126 of the pivot rod 94 is rotated, the threaded post 124 also rotates. Rotation of the threaded post 124 moves the pivot rod 124 into and out of the second nut 132 (which is prevented from rotating), thereby moving the grip 126 toward and away from the second nut 132 (as the threaded post 124 is “screwed” and “unscrewed”). The threaded post 124 of the pivot rod 94 extends through the opening 130 in the pull member 98 . The first nut 131 rotates with the threaded post 124 of the pivot rod 94 and thereby pulls on the pull member 98 when the grip 126 moves away from the second nut 132 . As the grip 126 moves away from the second nut 132 , the T-shaped projection 136 of the pull member 98 forces the pivot arm 96 to pivot.
[0020] In the illustrated example, the rotating gripping arm assembly 24 secures the clothes dryer 14 to the ladder 12 . The ladder 12 includes a pair of parallel vertical support beams 150 having a plurality of steps 152 extending therebetween. As illustrated in FIGS. 1 and 4 , a left one of the vertical support beams 150 is received within a first capture area 156 and a right one of the vertical support beams 150 is received within a second capture area 158 of the dryer body 16 . The first capture area 156 is located between the left portion free edge area 36 of the rear edge 34 of the body bottom half 20 and the body top half 22 and the outside plate 68 of the trapezoidal section 62 of the rear wall 28 of the body bottom half 20 and the rear wall 28 a of the body top half 22 . The second capture area 158 is located between the back wall area 60 of the rear wall 28 to the right of the rear U-shaped slot 76 and the concave face 122 of the pivot arm 96 . When the pivot rod 94 is fully screwed into the second nut 132 , the right one of the vertical support beams 150 can enter into the second capture area 158 . As the pivot rod 94 is rotated to move the grip 126 away from the second nut 132 , the pull member 98 forces the pivot arm 96 to pivot, thereby forcing the concave face 122 of the pivot arm 96 against the right one of the vertical support beams 150 and rigidly connecting the clothes dryer 14 to the ladder 12 .
[0021] The illustrated clothes dryer 14 can also be connected to a vertical surface 200 using a wall mount assembly 202 (see FIGS. 3-5 ). The wall mount assembly 202 includes a wall mount bracket 204 that is configured to be connected to the vertical surface 200 using fasteners 206 . The wall mount bracket 204 includes a rear plate 208 having a plurality of holes 210 for accepting the fasteners 206 therethrough, with the fasteners 206 being inserted into the vertical surface 200 (e.g., by screwing). A top projection 212 extends from a top edge 214 of the rear plate 208 and a bottom projection 216 extends from a bottom edge 218 of the rear plate 208 . The top projection 212 has a forwardly extending panel 220 and an inverted J-shaped panel 222 extending upwardly therefrom. The bottom projection 216 has a forwardly extending panel 224 and a J-shaped panel 226 extending downwardly therefrom. As illustrated in FIG. 4 , the rear wall 28 a of the body top half 22 and the rear wall 28 of the body bottom half 20 define a recess 250 that has an open first side 252 at the second capture area 158 and a closed second side 254 at the inside plate 70 of the trapezoidal section 62 of the rear wall 28 and the rear wall 28 a. A bottom of the recess 250 includes a bottom groove 256 and a top of the recess 250 includes a top groove 258 .
[0022] In the illustrated example, the wall mount assembly 202 is connected to the vertical surface 200 . The clothes dryer 14 can then be connected to the wall mount assembly 202 by sliding the wall mount bracket 204 into the recess 250 in the dryer body 16 from the open first side 252 of the recess 250 . As the wall mount bracket 204 is slid into the recess 250 , the inverted J-shaped panel 222 of the top projection 212 of the wall mount bracket 204 slides into the top groove 258 of the recess 250 and the J-shaped panel 226 of the bottom projection 216 slides into the bottom groove 256 of the recess 250 . The wall mount assembly 202 allows the clothes dryer 14 to be stored (e.g., for travel) and brought out and easily connected to the vertical surface 200 for use. Once the wall mount assembly 200 is connected to the vertical surface 200 , no tools are required to connect and disconnect the clothes dryer 14 thereto.
[0023] The illustrated dryer arms 18 are configured to be moved between a storage position as shown in FIG. 2 and a deployed position as shown in FIG. 1 . The dryer arms 18 have a first end with a pivot pin 300 (or a pair of aligned pivot pins) that extends downward and upward into the openings 48 in the support floor surface 30 of the support platform 26 of the body bottom half 20 and the body top half 22 , respectively. The pivot pin 300 allows each dryer arm 18 to be moved from the storage position to the deployed position and back again. The dryer arms 18 can have any configuration. Although the dryer arms 18 are illustrated as being a plurality of wires that can have clothes hung over top thereof or have hangers hung thereon, the dryer arms 18 can have any design (e.g., wires as shown or a single solid body). As outlined above, the openings 48 are located at a first end of the central angled area 42 , a second end of the central angled area 42 and between the first end and the second end of the central angled area 42 . The front to back spacing of the openings 48 are about equal to a width of the dryer arms 18 , Moreover, the openings 48 between the opening 48 at the first end and the opening 48 at the second end of the central angled area 42 are in a line. Therefore, when the dryer arms 18 are in the storage position, the dryer arms 18 are flat against each other as illustrated in FIG. 2 . Each arm 18 in the deployed position is located between a pair of the tabs 50 to maintain the arms 18 in the deployed position. It is contemplated that the arms 18 can be lifted over the tabs 50 (e.g., by having a height of the arms 18 other than the pivot pin 300 be smaller than the distance between the support floor surfaces 30 of the body bottom half 20 and the body top half 22 ) or that the tabs 50 can be flexible (e.g, made out of deformable material) to deform to allow arms 18 to pass thereby. It is further contemplated that, instead of the tabs 50 , the support floor surface 30 of the body bottom half 20 could include channels ending at the openings 48 such that a bottom of each arm 18 can rest in the openings 48 to maintain the arms 18 in the deployed position. It is further contemplated that each opening 48 could have one or more channels ending thereat.
[0024] Although particular preferred embodiments of the invention have been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention. For example, the clothes dryer 14 can be connected to any surface using the wall mount assembly 202 (in an RV or anywhere else).
[0025] The above description is considered that of the one embodiment only. Modification of the invention will occur to those skilled in the art and to those who make or use the invention. Therefore, it is understood that the embodiment shown in the drawings and described above is merely for illustrative purposes and not intended to limit the scope of the invention.
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A clothes dryer including a dryer body and at least three dryer arms pivotally connected to the dryer body about pivot points. The dryer arms can be folded into a stored position and moved to a deployed position wherein at least two of the dryer arms are spread out to allow clothes to be placed thereon or connected thereto for drying. Each of the dryer arms are able to be received in at least two channels such that each of the dryer arms can be positioned in a plurality of fixed deployed positions. The dryer body can also include a vertical slot for connecting the dryer body to a first support and a horizontal slot for connecting the dryer body to a second support. The dryer arms can have a generally planar profile with at least three pivot points thereof being positioned along a line.
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BACKGROUND OF THE INVENTION
This invention relates to a steel oil ring assembly used in an internal combustion engine. More particularly, the invention relates to improvements in the shape of the abutting end portions of a space-expander having a corrugated shape in the radial as well as in the axial direction.
A spacer expander 10 of the type shown in FIG. 1(a) often is used in a steel oil ring assembly of the abovementioned kind. The spacer expander 10 (hereinafter referred to simply as a "spacer") has corrugations in the radial direction and is embraced from above and below by an upper rail and a lower rail.
As shown in FIG. 1(a), the spacer 10 in a conventional steel oil ring assembly has a continuous corrugated shape in the radial direction and is formed to have an overall annular shape as seen from the axial direction. The spacer 10 is split at one location on the circumference thereof, and the split ends of the spacer 10 meet at a butt portion 11. When the spacer 10 is fitted into a separate piston and compressed by the inner wall of a cylinder, the split ends at the butt portion 11 come into pressured contact with each other in such a manner that a force point (junction point) a occupies a position considerably above a center line X-X' of the height of the spacer corrugations. As a result, the state of contact and the contact force between upper- and lower-rail abutting portions 12, 12' which project from the vicinity of the force point a and the inner peripheral surfaces of the respective upper and lower rails become non-uniform. Owing to the influence of this non-uniformity, the outer peripheral surfaces of the upper and lower rails present at the butt portion 11 assume a state in which they do not contact the cylinder wall surface correctly. This causes a reduction in the oil scraping effect of the oil ring.
Another example of a spacer according to the prior art is shown in FIG. 1(b).
As shown in FIG. 1(b), a spacer expander 110 has a corrugated shape in the axial direction and is also embraced from above and below by an upper rail and a lower rail.
The spacer 110 in this conventional steel oil ring assembly has a continuous corrugated shape in the axial direction and is formed to have an overall annular shape as seen from the axial direction. The spacer 110 is split at one location on the circumference thereof, and the split ends of the spacer 110 meet at a butt portion 111. When the spacer 110 is fitted into a piston and compressed by the inner wall of a cylinder, the split ends at the butt portion 111 come into pressured contact with each other in such a manner that the force point (junction point) a occupies a position considerably above the center line X-X' of the height of the spacer corrugations. As a result, the state of contact and the contact force between upper- and lower-rail abutting portions 112, 112' which project from the vicinity of the force point a and the inner peripheral surfaces of the respective upper and lower rails become non-uniform. Owing to the influence of this non-uniformity, the outer peripheral surfaces of the upper and lower rails present at the butt portion 111 assume a state in which they do not contact the cylinder wall surface correctly. This causes a reduction in the oil scraping effect of the oil ring.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a steel oil ring assembly in which an excellent oil scraping operation is performed by improving the position of the force point at the butt portion.
According to one aspect of the present invention, the foregoing object is attained by providing a steel oil ring assembly comprising an upper rail, a lower rail, and a spacer embraced from above and below by the upper and lower rails and having radially extending corrugations. The spacer is split at one location to form abutting ends which come into pressured contact with each other at a force point positioned on a line passing through the corrugations substantially at respective centers thereof in the radial direction. The spacer has an opening, which defines an angle of 10°±9°, extending radially outward from the force point at the abutting ends.
According to another aspect of the present invention, the foregoing object is attained by providing a steel oil ring assembly comprising an upper rail, a lower rail, and a spacer embraced from above and below by the upper and lower rails and having axially extending corrugations. The spacer is split at one location to form abutting ends which come into pressured contact with each other at a force point positioned on a line passing through the corrugations substantially at respective centers thereof in the axial direction. The spacer has an opening, which defines an angle of 10°±9°, extending upwardly from the force point at said abutting ends.
In accordance with the invention, the upper and lower rails make uniform contact with the inner wall of a cylinder over its entire circumference by virtue of the spacer. This makes it possible to improve oil scraping performance and to reduce the amount of lubricant consumed.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1(a) and 1(b) are enlarged plan views showing, in part, examples of spacers according to the prior art;
FIG. 2 is a transverse sectional view showing a spacer according to an embodiment of the present invention;
FIG. 3 is a an enlarged perspective view showing a portion of the spacer of FIG. 2;
FIG. 4 is a plan view showing, in part, the spacer of FIG. 3;
FIG. 5 is an enlarged front view illustrating the results of testing a steel oil ring assembly according to the embodiment of the invention;
FIG. 6 is an enlarged front view illustrating the results of testing a steel oil ring assembly according to the prior art;
FIG. 7 is a diagram showing test data illustrating the results of testing a steel oil ring assembly according to an embodiment of the invention and a steel oil ring assembly according to the prior art;
FIG. 8 is an enlarged perspective view showing a portion of a spacer according to a second embodiment of the present invention;
FIG. 9 is an enlarged front view showing a portion of the spacer of FIG. 8;
FIG. 10 is an enlarged front view illustrating the results of testing a steel oil ring assembly according to the second embodiment of the invention;
FIG. 11 is an enlarged front view illustrating the results of testing a steel oil ring assembly according to the prior art; and
FIG. 12 is a diagram showing test data illustrating the results of testing a steel oil ring assembly according to the second embodiment of the invention and a steel oil ring assembly according to the prior art.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Embodiments of a steel oil ring assembly according to the present invention will now be described with reference to the drawings.
As shown in FIG. 2, a steel oil ring assembly ordinarily includes a spacer-expander 1, an upper rail 2 and a lower rail 3. As illustrated in FIGS. 3 and 4, the spacer 1 is formed so that the overall shape thereof is annular as seen from the axial direction, and the spacer is split at one location on the circumference thereof to form abutting end portions 4 (also referred to as a "rafter" portion owing to its shape as seen from the vertical direction). Projections 5, 5' are formed on upper and lower portions, respectively, of the spacer 1 on the inner periphery thereof. Owing to the projections 5, 5', the upper and lower rails 2, 3 are urged toward the outer circumferential direction so as to press against the wall of a cylinder.
In accordance with the invention, and as shown in FIG. 4, the shape of the abutting end portions 4 is such that the force point a (junction point) is situated on the center line X-X' of the corrugations of the spacer 1 in the radial direction. In other words, point a is located in an axially extending annular plane that passes through the centers of the corrugations. The free ends of the abutting end portions 4 form an opening of angle θ in the outer circumferential direction. The angle θ is formed by grinding or plastic working, and a suitable range of values thereof is 10°±9°. The lower limit of 1° is a minimum value for which the opening can be maintained in terms of manufacture, and this suggests that the force point a will not lie above the center line X-X'. The upper limit of 19° is the boundary value for which stable contact can be obtained at the force point a in a state where a compressing force acts upon the spacer 1 when the spacer is fitted in the piston and inserted in the cylinder. This is also the boundary value at which burrs will not develop at the ends of the butt portions 4.
The steel oil ring assembly of this embodiment (FIG. 4) and the steel oil ring assembly of the prior art [FIG. 1(a)] were tested in a four-cycle gasoline engine in which the inner diameter of the cylinder was 76 mm. The results of the test will now be described.
Oil ring assemblies of this embodiment were finished by a dry-type grinding machine to give the angle θ between the free ends of the abutting end portions 4 a value of 8°±1°. FIGS. 5 and 6 show the states of the outer circumferential surface of the upper and lower rails in the vicinity of the spacer butt portion of abovementioned oil rings released after eight hours of a test run under the same conditions.
The results of the test applied to the present embodiment confirm that contact tracks 6, 7, which are left on the outer circumference of the upper rail 2 and lower rail 3 owing to contact with the cylinder wall, have a substantially uniform width over the entire circumference, as illustrated in FIG. 5.
By contrast, as a result of the test applied to the prior-art example of FIG. 1(a), contact tracks 15, 16 of the kind shown in FIG. 6 ar left on the outer circumference of an upper rail 13 and lower rail 14 owing to contact with the cylinder wall. These contact tracks 15, 16 are wide on both the upper and lower rails 13, 14 in the vicinity of the abutting end portions 11 but become narrower on the same rails between the two corrugations adjacent to the abutting end portions on either side thereof.
Further, FIG. 7 illustrates lubricant consumption obtained under three types of test conditions in a test applied after the engine test run. The differences between the present invention and the prior art are clearly shown. It was verified that both the upper and lower rails 2, 3 of the oil ring assembly of the present embodiment made uniform contact with the cylinder wall and exhibited an excellent oil scraping effect.
Thus, in accordance with this embodiment of the invention as described above, the upper and lower rails both contact the cylinder wall correctly and uniformly. As a result, the oil-scraping performance is improved and the amount of lubricant consumed can be reduced considerably in comparison with the prior art.
A second embodiment of a steel oil ring assembly according to the present invention will now be described with reference to FIGS. 8 through 12.
As shown in FIG. 8, a steel oil ring assembly ordinarily includes a spacer 101, an upper rail 102 and a lower rail 103. As illustrated in FIG. 9, the spacer 101 is formed so that the overall shape thereof is annular as seen from the axial direction, and the spacer is split at one location on the circumference thereof to form abutting end portions 104. Projections 105, 105' are formed on upper and lower portions, respectively, of the spacer 101 on the inner periphery thereof. Owing to the projections 105, 105', the upper and lower rails 102, 103 are urged toward the outer circumferential direction so as to press against the wall of a cylinder, not shown. In this embodiment the corrugations run in an axial direction whereas in the previous embodiment they ran in a radial direction.
The shape of the abutting end portions 104 is such that a force point a (junction point) is situated on the center line X-X' of the corrugations of the spacer 101 in the axial (vertical) direction. In other words, line X-X' is a plane extending in a radial direction that passes through the centers of the corrugations. The free ends of the abutting end portions 104 have an upwardly directed opening of angle θ. The angle θ is formed by grinding or plastic working, and a suitable range of values thereof is 10°±9°. The lower limit of 1° is a minimum value for which the opening can be maintained in terms of manufacture, and this suggests that the force point a will not lie above the center line X-X'. The upper limit of 19° is the boundary value for which stable contact can be obtained at the force point a in a state where a compressing force acts upon the spacer 101 when the spacer is fitted in the piston and inserted in the cylinder. This is also the boundary value at which burrs will not develop at the ends between the free ends of the abutting end portions 104.
The steel oil ring assembly of this embodiment (FIG. 9) and the steel oil ring assembly of the prior art [FIG. 1(b)] were tested in a four-cycle gasoline engine in which the inner diameter of the cylinder was 76 mm. The results of the test will now be described.
Oil ring assemblies of this embodiment were finished by a dry-type grinding machine to give the angle θ of the portions 104 a value of 8°±1°. FIGS. 10 and 11 show the states of the outer circumferential surface of the upper and lower rails in the vicinity of the spacer butt portion of abovementioned oil rings released after eight hours of a test run under the same conditions.
The results of the test applied to the second embodiment confirm that contact tracks 106, 107, which are left on the outer circumference of the upper rail 102 and lower rail 103 owing to contact with the cylinder wall, have a substantially uniform width over the entire circumference, as illustrated in FIG. 10.
By contrast, as a result of the test applied to the prior-art example of FIG. 1(b), contact tracks 115, 116 of the kind shown on FIG. 11 are left in the outer circumference of an upper rail 113 and lower rail 114 owing to contact with the cylinder wall. The contact track 115, 116 is wide on the lower rails 114 in the vicinity of the abutting end portions 111, but the contact track 115 of upper rail 113 is much narrower between the two corrugations adjacent the abutting portions.
Further, FIG. 12 illustrates lubricant consumption obtained under three types of test conditions in a test applied after the engine test run. The differences between the present invention and the prior art are clearly shown. It was verified that both the upper and lower rails 102, 103 of the oil ring assembly of the present embodiment made uniform contact with the cylinder wall and exhibited an excellent oil-scraping effect.
Thus, in accordance with the second embodiment of the invention as described above, the upper and lower rails both contact the cylinder wall correctly and uniformly. As a result, the oil scraping performance is improved and the amount of lubricant consumed can be reduced considerably in comparison with the prior art.
As many apparently widely different embodiments of the present invention can be made without departing from the spirit and scope thereof, it is to be understood that the invention is not limited to the specific embodiments thereof except as defined in the appended claims.
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A steel oil ring assembly having an upper rail, a lower rail and an annular space-expander embraced by the rails and having radially extending or axially extending corrugations. The spacer is split at one circumferential location to form abutting end portions which come into pressured contact with each other at a force point located on a plane passing through the centers of the corrugations that extends in an axial direction for radially extending corrugations and in a radial direction for axially extending corrugations. The free ends of the abutting end portions of the spacer form an opening having an angle of 10°±9° extending outwardly from the force point.
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BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention The present invention relates to an acid generating agent, and more particularly, to a salt useful as an acid generating agent contained in chemically amplified resist compositions that are used in semiconductor processes.
[0002] 2. Description of the Related Art
[0003] A chemically amplified resist composition used in the semiconductor fine processing utilizing lithography contains an acid generating agent, and as the technologies supporting the semiconductor fine processing continue to develop, a demand for resists with higher resolution still exists.
[0004] Therefore, in order to produce a resist having an increased resolution and desired properties, a large number of different acid generating agents have been developed, and in particular, numerous modifications and experiments in design have been carried out concerning the cation part of salts that are used as photo-acid generating agents, so as to improve the diffusion rate of acid and transparency, which are important properties required from an acid generating agent.
[0005] However, in the recent research on resist compositions, the improvement of the properties of resist based on the cation of photo-acid generating agents is facing the limit, and there is rising another problem of reducing the amount of the salt of a photo-acid generating agent eluted into water, as water is used in the processes of argon fluoride (ArFi) immersion lithography.
[0006] Therefore, in recent years, the development of acid generating agents is being achieved with more focus on the anion part, on the bases of numerous experimental results and reports showing that the anion moiety has substantially greater influence than the cation moiety in terms of the physical and chemical characteristics which can improve the fluidity of acid and the properties of the resist composition. Now, the trend of the development is inclined toward photo-acid generating agents which are capable of reducing the diffusion rate of acid, and have good transmissibility of ArF laser at 193 nm. Accordingly, there are competitive attempts to introduce a bulky alicyclic ring into the anion of a salt which is suitable as a photo-acid generating agent.
SUMMARY OF THE INVENTION
[0007] In an attempt to address such problems as described above, there is provided, according to an aspect of the present invention, a novel acid generating agent useful for chemically amplified resist compositions, which agent has excellent resolution and line width roughness, and is eluted less readily into water in the processes of ArF immersion lithography.
[0008] According to another aspect of the present invention, there is provided an intermediate used in the production of the acid generating agent, and a method for synthesizing the intermediate substance.
[0009] The acid generating agent according to embodiments of the present invention is represented by the following formula (1).
[0000]
[0010] wherein X represents a monocyclic or polycyclic hydrocarbon group having 3 to 30 carbon atoms, and having at least one hydrogen atom on the ring substituted by an alkyl or alkoxy group which has 1 to 10 carbon atoms and may be unsubstituted or substituted with a group selected from an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group and an aldehyde group, or by a perfluoroalkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, or a cyano group; R 6 is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a heteroatom selected from the group consisting of nitrogen (N), sulfur (S) and fluorine (F); m is an integer from 0 to 2; and A+ is an organic counterion.
[0011] Specific examples of the ring X include a monocyclic hydrocarbon group having 3 to 12 carbon atoms, a bicyclic hydrocarbon group having 8 to 20 carbon atoms, a tricyclic hydrocarbon group having 10 to 30 carbon atoms, a tetracyclic hydrocarbon group having 10 to 30 carbon atoms, and the like.
[0012] Also, the X represents an adamantyl group, a norbornyl group or a cycloalkyl group.
[0013] Such monocyclic, bicyclic, tricyclic and tetracyclic groups may be exemplified by the compounds represented by the following formulas (1-a) to (1-h).
[0000]
[0014] The ring X has one hydrogen atom at any position bound to an adjacent group, and at least one hydrogen atom among the hydrogen atoms present on the ring excluding the hydrogen atom bound to an adjacent group, is substituted by an alkyl or alkoxy group having 1 to 10 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, or the like.
[0015] The anion represented by the formula (1) according to an embodiment of the present invention may be exemplified by compounds represented by the following formulas (1-i) to (1-xx):
[0000]
[0016] In the formula (1), A+ represents an organic counterion, and examples thereof include ions represented by the following formulas (2a), (2b), (3a) and (3b), and the like:
[0000]
[0017] wherein in the formulas (2a) and (2b), R 1 and R 2 each independently represent an alkyl group, an allyl group, a perfluoroalkyl group, a benzyl group or an aryl group; and R 3 , R 4 and R 5 each independently represent a hydrogen atom, an alkyl group, a halogen group, an alkoxy group, an aryl group, a thiophenoxy group, a thioalkoxy group or an alkoxycarbonylmethoxy group.
[0018] More specific examples of these substituents include, as the alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a phenyl group, a hexyl group, an octyl group and the like; and as the alkoxy group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, an octyloxy group and the like.
[0000]
[0019] wherein in the formulas (3a) and (3b), R 1 and R 4 each independently represent an alkyl group, an allyl group, a perfluoroalkyl group, a benzyl group or an aryl group; and R 2 and R 3 each independently represent a hydrogen atom, an alkyl group, a halogen group, an alkoxy group, an aryl group, a thiophenoxy group, a thioalkoxy group or an alkoxycarbonylmethoxy group.
[0020] More specific examples of these substituents include, as the alkyl group, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a phenyl group, a hexyl group, an octyl group and the like; and as the alkoxy group, a methoxy group, an ethoxy group, a propoxy group, a butoxy group, a hexyloxy group, an octyloxy group and the like.
[0021] Furthermore, specific examples of the ions of formula 2a or 2b include those selected from the group consisting of ions represented by the following formulas (2-i) to (2-xx):
[0000]
[0022] Specific examples of the ions of formula (3a) or (3b) include those selected from the group consisting of ions represented by the following formulas (3-i) to (3-ix):
[0000]
[0023] According to an embodiment of the present invention, specific examples of the novel acid generating agent include the following salts represented by the following formulas (4a), (4b), (4c) and (4d):
[0000]
[0024] In the formulas (4a) and (4b), R 1 and R 2 each independently represent an alkyl group, an allyl group, a perfluoroalkyl group, a benzyl group or an aryl group; and R 3 , R 4 and R 5 each independently represent a hydrogen atom, an alkyl group, a halogen atom, an alkoxy group, an aryl group, a thiophenoxy group, a thioalkoxy group or an alkoxycarbonylmethoxy group. In the formulas (4c) and (4d), R 1 represents an alkyl group, an allyl group, a perfluoroalkyl group, a benzyl group or an aryl group; and R 2 , R 3 and R 4 each independently represent a hydrogen atom, an alkyl group, a halogen atom, an alkoxy group, an aryl group, a thiophenoxy group, a thioalkoxy group or an alkoxycarbonylmethoxy group. In all of the above formulas, B commonly represents the following formula (5), (6) or (7):
[0000]
[0025] Hereinafter, the method for producing an acid generating agent represented by the formula (1) will be discussed.
[0026] According to an embodiment of the present invention, as the method for producing a salt represented by the formula (1), there may be used a method including reacting a compound represented by the following Formula (8) with a compound represented by the following formula (12) at a temperature of 0 to 100° C., using a mixture of water and an organic solvent such as dichloromethane, chloroform or dichloroethane:
[0000] A + Z − [Formula 12]
[0027] wherein in the above formulas (8) and (12), X represents a monocyclic or polycyclic hydrocarbon group having 3 to 30 carbon atoms, and having at least one hydrogen atom on the ring substituted by an alkyl or alkoxy group which has 1 to 10 carbon atoms and may be unsubstituted or substituted with a group selected from an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group and an aldehyde group, or by a perfluoroalkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, or a cyano group; R 6 is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a heteroatom selected from the group consisting of N, S and F; m is an integer from 0 to 2; M is lithium (Li), sodium (Na) or potassium (K); Z is OSO 2 CF 3 , OSO 2 C 4 F 9 , OSO 2 C 8 F 17 , N(CF 3 ) 2 , N(C 2 F 5 ) 2 , N(C 4 F 9 ) 2 , C(CF 3 ) 3 , C(C 2 F 5 ) 3 , C(C 4 Fg) 3 , fluorine (F), chlorine (Cl), bromine (Br), iodine (I), BF 4 , ASF 6 or PF 6 ; and A+ is an organic counterion.
[0028] The amount of use of the compound represented by formula (8) is about 1 to 2 moles based on the compound represented by formula (12). The salt of formula (1) thus obtained may be recovered, if obtained in a solid form, after purification by a recrystallization method, or a solidification method using a mixture of a good solvent and a poor solvent for the salt. If the salt is obtained in an oily form, the salt may be recovered after extraction with a solvent, or concentration.
[0029] As an example of the method for producing the compound of formula (8), a method of reacting an alcohol represented by the following formula (10) with carbonyl chloride represented by the following formula (11) may be used:
[0000]
[0030] In the formula (10), M is Li, Na or K. In the formula (11), ring X represents a monocyclic or polycyclic hydrocarbon group having 3 to 30 carbon atoms, and having at least one hydrogen atom on the ring substituted by an alkyl or alkoxy group which has 1 to 10 carbon atoms and may be unsubstituted or substituted with a group selected from an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group and an aldehyde group, or by a perfluoroalkyl group having 1 to 4 carbon atoms, a hydroxyalkyl group having 1 to 10 carbon atoms, or a cyano group; R 6 is an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a heteroatom selected from the group consisting of N, S and F; and m is an integer from 0 to 2.
[0031] Specifically, in this method, an alcohol represented by the formula (10) and carbonyl chloride represented by the formula (11) are dissolved in a reaction solvent such as dichloromethane, chloroform, dichloroethane, acetonitrile or toluene generally at a temperature of 0 to 100° C., and then the dissolved reactants are allowed to react in the presence of a basic catalyst such as triethylamine, diethylamine, pyridine or diethylisopropylamine in an amount of about 1 to 2 moles based on the reactant of formula (11), or in the presence of N,N-dimethylaminopyridine as a catalyst in an amount of 0.1 to 0.5 moles based on the total amount of reactants.
[0032] In an exemplary method for producing the alcohol of formula (10), an ester compound represented by the following formula (9) is dissolved in tetrahydrofuran and an alcoholic solvent such as methanol, ethanol or propanol, and reducing agent is slowly added dropwise to the solution in an ice bath. After completion of the dropwise addition, the reaction mixture is stirred in an oil bath at 60° C. for about 4 hours, and then is quenched with distilled water to remove the solvents. The reaction mixture which is now free of solvent, is dissolved again in distilled water, and then the mixture is acidified to pH 5 to 6 using concentrated hydrochloric acid. The resulting mixture is concentrated, and then methanol is added thereto to form a slurry. The slurry is filtered, and the filtrate is washed with hexane, concentrated again, and is subjected to crystallization from diethyl ether. The obtained crystals is then filtered and dried to give the alcohol of formula (10).
[0000]
[0033] wherein R 1 is selected from the group consisting of hydrogen, methyl, trifluoromethyl, trichloromethyl, tribromomethyl and triiodomethyl; and M is Li, Na or K.
[0034] The acid generating agent according to embodiments of the present invention, which is formed by introducing an alicyclic ring into an anion, has advantages of being capable of controlling the diffusion rate of acid, exhibiting high light transmissibility when used in connection with an ArF light source.
[0035] The reducing agent is selected from sodium borohydride (NaBH4), lithium aluminum hydride (LiAlH4), BH3-THF, NaBH4-AlCl3, NaBH4-LiCl, and LiAl(OMe) 3 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] FIG. 1 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 1-1;
[0037] FIG. 2 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 1-2;
[0038] FIG. 3 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 1-3;
[0039] FIG. 4 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 2-1;
[0040] FIG. 5 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 2-2;
[0041] FIG. 6 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 3-1;
[0042] FIG. 7 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 3-2;
[0043] FIG. 8 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 6-1;
[0044] FIG. 9 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 6-2;
[0045] FIG. 10 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 7-1; and
[0046] FIG. 11 is a 1 H-NMR spectrum of the compound produced according to Synthesis Example 7-2.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0047] Hereinafter, the present invention will be described in detail with reference to preferred Synthesis Examples and Examples. However, it should be noted that the present invention is not intended to be limited to these Examples.
Synthesis Example 1
Adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt
[0048] (1) 83 g of difluorosulfoacetic acid ethyl ester sodium salt is dissolved in 160 ml of methanol and 1.2 L of tetra hydrofuran (THF) in an ice bath, and 44 g of sodium borohydride (NaBH 4 ) is slowly added dropwise to the solution. After completion of the dropwise addition, the ice bath is removed, and the system temperature is elevated to 60° C., at which temperature the reaction system is stirred for about 4 hours.
[0049] When the reaction is completed, the reaction mixture is quenched with distilled water, and then the solvent is removed. The crude reaction mixture is dissolved again in distilled water, and is acidified to pH 5 to 6 using concentrated hydrochloric acid. Subsequently, methanol is added to the concentrated mixture, and the slurry thus formed is filtered to remove inorganic salts. The filtrate is washed two times with hexane, the methanol layer is concentrated again, and then crystallization is performed using diethyl ether. The white solid obtained after the filtration is dried in vacuum, and the structure of the dried product is confirmed by 1 H-NMR. The 1 H-NMR spectrum of the obtained product is presented in FIG. 1 . As such, 68.5 g (yield 95%) of difluorohydroxyethanesulfonic acid sodium salt was obtained.
[0050] 1 H-NMR (D 2 O): δ (ppm) 4.18 (t, 2H)
[0000]
[0051] (2) 20 g of the difluorohydroxyethanesulfonic acid sodium salt produced as described above, and 29 g of adamantanecarbonyl chloride are dissolved in 400 ml of dichloroethane, and the solution is stirred at ambient temperature. 23 ml of triethylamine is slowly added dropwise to the solution at ambient temperature, and then the reaction temperature is elevated to 60° C., at which temperature the reaction system is stirred for 2 hours.
[0052] After completion of the reaction, the reaction solvent is removed, and ethyl ether is added to form a slurry. The slurry is filtered, and then filter cake is washed with distilled water and ethyl ether, and dried in vacuum. The structure of the dried product is confirmed by 1 H-NMR. The 1 H-NMR spectrum of the obtained product is presented in FIG. 2 . As such, 30 g (yield 80%) of adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt was obtained.
[0053] 1 H-NMR (DMSO-d 6 , internal standard: tetramethylsilane) δ (ppm) 1.67-1.98 (m, 15H), 4.52 (t, 2H)
[0000]
[0054] (3) 8.5 g of the adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt produced in (2), and 10 g of diphenyl methylphenyl sulfonium trifluoromethanesulfonate are dissolved in 100 ml of dichloromethane and 100 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0055] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 13.3 g (yield 94.3%) of adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl fluorophenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 3 .
[0056] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 1.67-1.98 (m, 15H), 2.47 (s, 3H), 4.76 (t, 2H), 7.48 (d, 2H), 7.65-7.76 (m, 12H)
[0000]
Synthesis Example 2
[0057] (1) 10 g of the difluorohydroxyethanesulfonic acid sodium salt produced in Synthesis Example 1-(1), and 8.7 ml of cyclohexanecarbonyl chloride are dissolved in 400 ml of dichloroethane, and the system is stirred at ambient temperature. 23 ml of triethylamine is slowly added dropwise at ambient temperature, and then the reaction temperature is elevated to 60° C., at which temperature the reaction system is stirred for 2 hours.
[0058] After completion of the reaction, the reaction solvent is removed, and ethyl ether is added to form a slurry. The slurry is filtered, and then filter cake is washed with distilled water and ethyl ether, and dried in vacuum. The structure of the dried product is confirmed by 1 H-NMR. The 1 H-NMR spectrum of the obtained product is presented in FIG. 4 . As such, 12.9 g (yield 81.2%) of cyclohexanecarboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt having a structure as shown below was obtained.
[0059] 1 H-NMR (DMSO-d 6 , internal standard: tetramethylsilane): δ (ppm) 1.21-1.92 (m, 10H), 2.40 (m, 1H), 4.52 (t, 2H)
[0000]
[0060] (2) 8.3 g of the cyclohexanecarboxylic acid-2,2-difluoro-2-sulfoethyl ester sodium salt produced in (1), and 10 g of diphenyl methylphenyl sulfonium trifluoromethanesulfonate are dissolved in 100 ml of dichloromethane and 100 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0061] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 12 g (yield 95.2%) of cyclohexanecarboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 5 .
[0062] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 1.18-2.05 (m, 10H), 2.42 (m, 1H), 2.46 (s, 3H), 4.77 (t, 2H), 7.48 (d, 2H), 7.65-7.76 (m, 12H)
[0000]
Synthesis Example 3
[0063] (1) 20 g of the difluorohydroxyethanesulfonic acid sodium salt produced in Synthesis Example 1-(1), and 26 g of norbornanecarbonyl chloride are dissolved in 400 ml of dichloroethane, and the system is stirred at ambient temperature. 30.4 ml of triethylamine is slowly added dropwise at ambient temperature, and then the reaction temperature is elevated to 60° C., at which temperature the reaction system is stirred for 2 hours.
[0064] After completion of the reaction, the reaction solvent is removed, and ethyl ether is added to form a slurry. The slurry is filtered, and then filter cake is washed with distilled water and ethyl ether, and dried in vacuum. The structure of the dried product is confirmed by 1 H-NMR. The 1 H-NMR spectrum of the obtained product is presented in FIG. 6 . As such, 28.9 g (yield 86.2%) of bicyclo[2.2.1]heptane-2-carboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt having a structure as shown below was obtained.
[0065] 1 H-NMR (DMSO-d 6 , internal standard: tetramethylsilane) δ (ppm) 1.15-2.82 (m, 1H), 4.57 (m, 2H)
[0000]
[0066] (2) 15.1 g of the bicyclo[2.2.1]heptane-2-carboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt produced in (1), and 15 g of diphenyl methylphenyl sulfonium trifluoromethanesulfonate are dissolved in 150 ml of dichloromethane and 150 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0067] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 18.8 g (yield 95.2%) of bicyclo[2.2.1]heptane-2-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 7 .
[0068] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 1.51-2.84 (m, 11H), 2.46 (s, 3H), 4.77 (m, 2H), 7.48 (d, 2H), 7.65-7.76 (m, 12H)
[0000]
Synthesis Example 4
[0069] (1) 7 g of the adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt produced in Synthesis Example 1-(2), and 10 g of diphenyl t-butoxycarbonylmethoxyphenyl sulfonium trifluoromethanesulfonate are dissolved in 100 ml of dichloromethane and 100 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0070] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 12.2 g (yield 94.6%) of adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl t-butoxycarbonylmethoxyphenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 8 .
[0071] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 1.48 (s, 9H), 1.67-1.98 (m, 15H), 2.47 (s, 3H), 4.62 (s, 2H), 4.76 (t, 2H), 7.17 (d, 2H), 7.65-7.77 (m, 12H)
[0000]
Synthesis Example 5
[0072] (1) 8.9 g of the adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt produced in Synthesis Example 1-(2), and 10 g of diphenyl fluorophenyl sulfonium trifluoromethanesulfonate are dissolved in 100 ml of dichloromethane and 100 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0073] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 12.8 g (yield 92.1%) of adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl fluorophenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 9 .
[0074] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 1.67-1.98 (m, 15H), 4.76 (t, 2H), 7.36-7.91 (m, 14H)
[0000]
Synthesis Example 6
[0075] (1) 10 g of the difluorohydroxyethanesulfonic acid sodium salt produced in Synthesis Example 1-(1), and 10.5 ml of cyclohexaneacetyl chloride are dissolved in 150 ml of dichloroethane, and the system is stirred at ambient temperature. 11 ml of triethylamine is slowly added dropwise at ambient temperature, and then the reaction system is stirred for 12 hours at ambient temperature.
[0076] After completion of the reaction, the reaction solvent is removed, and ethyl ether is added to form a slurry. The slurry is filtered, and then filter cake is washed with distilled water and ethyl ether, and dried in vacuum. The structure of the dried product is confirmed by 1 H-NMR. The 1 H-NMR spectrum of the obtained product is presented in FIG. 10 . As such, 15 g (yield 89.6%) of cyclohexylacetic acid 2,2-difluoro-2-sulfoethyl ester sodium salt having a structure as shown below was obtained.
[0077] 1 H-NMR (DMSO-d 6 , internal standard: tetramethylsilane): δ (ppm) 0.82-1.75 (m, 1H), 2.26 (d, 2H), 4.53 (t, 2H)
[0000]
[0078] (2) 9.1 g of the cyclohexylacetic acid 2,2-difluoro-2-sulfoethyl ester sodium salt produced in (1), and 9 g of diphenyl methylphenyl sulfonium trifluoromethanesulfonate are dissolved in 90 ml of dichloromethane and 90 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0079] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 11.6 g (yield 98.1%) of cyclohexylacetic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 11 .
[0080] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 0.82-1.67 (m, 11H), 2.24 (d, 2H), 2.62 (s, 3H), 4.79 (t, 2H), 7.49 (d, 2H), 7.65-7.76 (m, 12H)
[0000]
Synthesis Example 7
[0081] (1) 20 g of the difluorohydroxyethanesulfonic acid sodium salt produced in Synthesis Example 1-(1), and 28.3 g of norbornaneacetyl chloride are dissolved in 400 ml of dichloroethane, and the system is stirred at ambient temperature. 30.4 ml of triethylamine is slowly added dropwise at ambient temperature, and then the reaction temperature is elevated to 60° C., at which temperature the reaction system is stirred for 2 hours.
[0082] After completion of the reaction, the reaction solvent is removed, and ethyl ether is added to form a slurry. The slurry is filtered, and then filter cake is washed with distilled water and ethyl ether, and dried in vacuum. The structure of the dried product is confirmed by 1 H-NMR. The 1 H-NMR spectrum of the obtained product is presented in FIG. 12 . As such, 32 g (yield 91.7%) of bicyclo[2.2.1]heptane-2-acetic acid 2,2-difluoro-2-sulfoethyl ester sodium salt having a structure as shown below was obtained.
[0083] 1 H-NMR (DMSO-d 6 , internal standard: tetramethylsilane) δ (ppm) 0.81-2.42 (m, 13H), 4.53 (t, 2H)
[0000]
[0084] (2) 15.8 g of the bicyclo[2.2.1]heptane-2-acetic acid 2,2-difluoro-2-sulfoethyl ester sodium salt produced in (2), and 15 g of diphenyl methylphenyl sulfonium trifluoromethanesulfonate are dissolved in 150 ml of dichloromethane and 150 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0085] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 17 g (yield 81.7%) of bicyclo[2.2.1]heptane-2-acetic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 13 .
[0086] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 0.81-2.18 (m, 13H), 2.32 (s, 3H), 4.78 (t, 2H), 7.49 (d, 2H), 7.65-7.76 (m, 12H)
[0000]
Synthesis Example 8
[0087] (1) 10 g of the difluorohydroxyethanesulfonic acid sodium salt produced in Synthesis Example 1-(1), and 12 g of adamantaneacetyl chloride are dissolved in 150 ml of dichloroethane, and the system is stirred at ambient temperature. 11 ml of triethylamine is slowly added dropwise at ambient temperature, and then the reaction system is stirred for 12 hours at ambient temperature.
[0088] After completion of the reaction, the reaction solvent is removed, and ethyl ether is added to form a slurry. The slurry is filtered, and then filter cake is washed with distilled water and ethyl ether, and dried in vacuum. The structure of the dried product is confirmed by 1 H-NMR. The 1 H-NMR spectrum of the obtained product is presented in FIG. 14 . As such, 16 g (yield 79%) of adamantylacetic acid 2,2-difluoro-2-sulfoethyl ester sodium salt having a structure as shown below was obtained.
[0089] 1 H-NMR (DMSO-d 6 , internal standard: tetramethylsilane): δ (ppm) 0.82-1.75 (m, 11H), 2.26 (d, 2H), 4.53 (t, 2H)
[0000]
[0090] (2) 10 g of the adamantylacetic acid 2,2-difluoro-2-sulfoethyl ester sodium salt produced in (1), and 12 g of diphenyl methylphenyl sulfonium trifluoromethanesulfonate are dissolved in 90 ml of dichloromethane and 90 ml of water, and the system is allowed to undergo a two-layer reaction with vigorous stirring for 3 hours.
[0091] After completion of the stirring, an aliquot of the organic layer is removed, and the progress of the reaction is checked by 19 F-NMR. When the reaction goes to completion, the organic layers are combined, the solvent is removed, and the residues are washed with dichloromethane which is a good solvent, and with hexane which is a poor solvent. The solvents are removed, and the residues are dried under reduced pressure. Thus, 20 g (yield 95%) of adamantylacetic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt was obtained, and the structure of the product was confirmed by 1 H-NMR. The obtained spectrum is presented in FIG. 15 .
[0092] 1 H-NMR (chloroform-d 3 , internal standard: tetramethylsilane): δ (ppm) 0.81-2.18 (m, 13H), 2.32 (s, 3H), 4.78 (t, 2H), 7.49 (d, 2H), 7.65-7.76 (m, 12H)
[0000]
Resin Synthesis Example 1
[0093] 3-Bicyclo[2.2.1]hept-5-en-2-yl-3-hydroxypropionic acid t-butyl ester (hereinafter, referred to as BHP), 1-methyladamantane acrylate and gamma-butyrolactone methyl acrylate are charged at a molar ratio of 1:1:1 (33 parts:33 parts:33 parts), and the mixture is allowed to react at 65° C. for 16 hours using 1,4-dioxane as a polymerization solvent in an amount of three-fold the total mass of the reaction monomers, and using azobisisobutyronitrile as an initiator in a proportion of 4% by mole based on the total molar amount of the monomers.
[0094] After the reaction, the reaction solution is immersed in n-hexane, and dried in vacuum to obtain the following resin. As a result, a copolymer having a weight average molecular weight of about 8,500 was obtained.
[0095] [Preparation of Resist, Examples 1 to 3 and Comparative Example 1]
Example 1
Preparation of Resist
[0096] To 100 parts by weight of the resin obtained in Resin Synthesis 1, 4 parts by weight of the adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt produced in Synthesis Example 1 as an acid generating agent, and 0.5 parts by weight of tetramethylammonium hydroxide as a basic additive were dissolved in 1,000 parts by weight of propylene glycol methyl ether acetate, and then the solution was filtered through a membrane filter having a pore size of 0.2 μm, to obtain a resist.
[0097] The obtained resist solution was applied on a substrate using a spinner, and dried at 110° C. for 90 seconds to form a coating film having a thickness of 0.20 μm. The formed film was exposed to an ArF excimer laser stepper (numerical aperture: 0.78), and then the film was heat treated at 110° C. for 90 seconds. Subsequently, development was performed with a 2.38 wt % aqueous solution of tetramethylammonium hydroxide for 40 seconds, and then washing and drying were performed to form a resist pattern.
[0098] The developability using an aqueous solution of tetramethylammonium hydroxide and the adhesiveness of the formed resist pattern to the substrate were good, and the resolution was 0.07 μm, while the sensitivity was 12 mJ/cm 2 .
[0099] From the results of the Example, in the case of LER the pattern roughness of the 0.10 μm line-and-space (L/S) pattern formed after the development was observed, and the degree of improvement from the viewpoint of LER was graded from 1 to 5 (higher number corresponding to better LER), with the pattern obtained in Comparative Example being 1.
[0100] In the case of sensitivity, the amount of exposure for forming a 0.10 μm line-and-space (L/S) pattern formed after the development at a line width of 1:1, was designated as the optimum amount of exposure, and this optimum amount of exposure was taken as the sensitivity. The minimum pattern dimension obtained was taken as the resolution.
Examples 1 to 3
[0101] Each of the resins produced in the Resin Synthesis Example 1 using the PAG obtained in the Synthesis Examples 1, 2 and 3, and a basic additive were dissolved in 1,000 parts by weight of propylene glycol methyl ether acetate, and then the solution was filtered through a membrane filter having a pore size of 0.2 μm. Thus, the resist compositions shown in Table 1 (provided that the parts are parts by weight) were prepared. Positive resist patterns were formed by performing the same processes as in Example 1, and then various evaluations were performed. The evaluation results are presented in Table 1.
[0000]
TABLE 1
Resin
*PAG
*Base
Sensi-
(100
(parts
(parts
tivity
parts by
by
by
(mJ/
Resolution
weight)
weight)
weight)
cm 2 )
(nm)
LER
Example 1
Resin
4.0
0.5
12
70
4
Synthesis
Example 1
Example 2
Resin
4.0
0.5
12
80
3
Synthesis
Example 1
Example 3
Resin
4.0
0.5
12
70
3
Synthesis
Example 1
Comparative
Resin
4.0
0.5
14
90
1
Example 1
Synthesis
Example 1
*Kind of PAG used in Table 1
Example 1
[0000]
Adamantane-1-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt of Synthesis Example 1
Example 2
[0000]
Cyclohexanecarboxylic acid 2,2-difluoro-2-sulfoethyl ester sodium salt of Synthesis Example 2
Example 3
[0000]
Bicyclo[2.2.1]heptane-2-carboxylic acid 2,2-difluoro-2-sulfoethyl ester diphenyl methylphenyl sulfonium salt
Comparative Example 1
[0000]
Triphenylsulfonium Triflate
|
An acid generating agent used for chemically amplified resist compositions is provided, which agent is represented by the following formula (1):
wherein X represents a monocyclic or polycyclic hydrocarbon group having 3 to 30 carbon atoms, and having at least one hydrogen atom on the ring substituted by an alkyl or alkoxy group which and may be unsubstituted or substituted with a group selected from an ether group, an ester group, a carbonyl group, an acetal group, an epoxy group, a nitrile group and an aldehyde group, or by a perfluoroalkyl group, a hydroxyalkyl group, or a cyano group; R 6 is an alkyl group, an alkoxy group, or a heteroatom selected from the group consisting of N, S and F; m is an integer from 0 to 2; and A+ is an organic counterion.
| 2
|
BACKGROUND OF THE INVENTION
The present invention relates very generally to a method and apparatus for weighing material, and pertains, more particularly, to a method and associated apparatus for separately weighing contributions of material from multiple streams thereof and carrying out this separate weighing using a common scale.
In the printing process, and in other production processes, particularly where a continuous supply of material, such as paper from a roll is fed through a printing press, it is desired to maintain an accurate count of the products from the production process. As long as all of the products from the process are usable, in the case of the printing process, the count is equal to the number of revolutions of the printing press. However, it typically happens that in the course of carrying out the process, some of the products or materials are spoiled for one reason or the other and must be discarded. Thus, the total count of press impressions is no longer a measure of the total count of good product produced. It is and has been thus necessary either to count the good product independently, or to maintain an accurate accounting of the number of products discarded, so that this number can be subtracted from the known total count to obtain an accurate figure for the net "good" count.
A common method for counting "good" products or materials from a printing press is with the use of two counters. One of these is a gross counter which counts every revolution of the press whether a "good" product is produced or whether the product is to be discarded. The other counter is a net counter. The net counter can be turned on and off by the press operator, in accordance with whether he thinks the copies being made are acceptable or not. The problem with this technique is that it is subject to error as the operator may be unaware that the press has started to produce copies that should be discarded and therefore the operator may fail to set the counter. It is typical that when the defect is discovered, that the operator may estimate the number in order to prevent the necessity of restarting the net counter when good copies are again produced.
To overcome the aforementioned problem, ratio scales have been employed to measure the number of signatures (impressions or sheets in the case of paper) discarded. The number so determined is subtracted from the gross count to obtain a more accurate net count. Alternatively, when the number of signatures discarded is determined from the ratio scale, this may be added to the required number of "good" counts in order to determine the gross counter reading at which the press is to be stopped. Although this technique is somewhat of an improvement, it is still subject to human error because of the bookkeeping involved. Also, because one printing press typically produces up to four different products at one time, the bookkeeping becomes particularly complicated. Also, the bookkeeping or record keeping is complicated by virtue of the fact that usually only one scale is used to measure the waste paper from several deliveries of the same press.
Another technique that is employed involves the use of separate scales for each product. However, this technique requires substantial floor space and is also very expensive to implement. Still another common technique is to employ one scale but with multiple operator buttons such as four operator buttons to allow the press man to enter which printing stream the last weight came from. This technique require too much operator involvement and slows the process since several people may be depositing sheets at one time. A variation of these techniques uses a small scale or scales to weight the individual bundles before they are deposited in the central bin. This variation has all the above-mentioned problems and further requires an extra step.
Accordingly, it is an object of the present invention to provide a method and associated apparatus for separately weighing contributions of material, typically in sheet form from a printing press, from multiple streams thereof, and providing this weighing with a common scale. Another object of this invention is to provide an apparatus for registering accurate "good" counts from each of multiple press deliveries using a common scale.
A further object of the present invention is to provide an improved method and apparatus for weighing material in accordance with the objects and in which the method is carried out without the need for manual record keeping or manual entry of data.
Still another object of the present invention is to provide an improved method and associated apparatus for weighing materials from multiple streams with a common scale and wherein the apparatus is safe to operate, jam proof, accurate in operation, and easy to maintain.
To accomplish the foregoing and other objects of this invention there is provided in accordance with one aspect thereof, apparatus for weighing material from multiple streams with a common scale, which apparatus comprises a plurality of separate means, each for temporary storage of a quantity of said material that is to be weighed. In the embodiment described herein, the material may be in the form of paper used in a printing process and the weighing is of spoiled product. The apparatus of the present invention is for use with a single common scale and yet provides for a total count of waste material for each of the plurality of storage means. In addition to the plurality of separate means for this temporary storage of the material and the common scale means, the apparatus also comprises means for sequentially releasing the material from the respective separate means for storing so as to enable delivery thereof to the common scale means. This is typically carried out with the use of a common storage bin associated with the scale means. Electronic means is used for control and includes means responsive to the scale reading for sensing increments in scale weight for each respective release of material. The electronic circuitry has to determine with which of the deliveries the weight increment corresponds. Thus, there is provided a means for totaling the respectively sensed weight increments to provide a plurality of separate counts corresponding to weight and associated with each of the respective means for storage. In accordance with the invention the storage means may comprise a hopper and the means for releasing may be constructed in combination with the storage means in one of two preferred forms described herein. This may comprise either a metered discharge which may be in the form of a gate cover or moving aperture arranged to open at the time of discharge and to be closed at all other times. The delayed transport technique may comprise a conveyor used to carry the material towards the discharge opening. When the conveyor is operated it will discharge the material upon it into the waste bin below. When it is stopped, it will store material for the next discharge cycle. The means for sensing increments in scale weight may comprise a difference means or a difference circuit having an output count or magnitude corresponding to the difference in weight between a present scale weight and the next scale weight after operation of the means for releasing. Preferably, means are provided for converting the weight factor sensed to a count that corresponds to the number of pieces of material released in a batch. The means for totalling substantially adds counts corresponding to weight and displays a count indicating total pieces weighed per stream.
In accordance with another aspect of the present invention, there is provided a method of weighing material from multiple streams with a common scale. This method comprises the steps of separately and temporarily storing a quantity of the material that is to be weighed from each respective stream and sequentially and mutually exclusively releasing the material from its temporary storage to the scale. The next step is that of sequentially sensing increments in scale weight for each respective release of material. Finally, each of these increments corresponding to a predetermined stream is added so as to accumulate sensed weight increments associated with each respective stream.
BRIEF DESCRIPTION OF THE DRAWINGS
Numerous other objects, features and advantages of the invention should now become apparent upon a reading of the following detailed description taken in conjunction with the accompanying drawing, in which:
FIG. 1 is a perspective view of a portion of the apparatus of the present invention showing the separate storage hoppers, the waste bin, and associated scale;
FIG. 2 is a fragmentary cross-sectional view of one embodiment of the apparatus illustrating the meter discharge technique;
FIG. 3 is a fragmentary cross-sectional view of one embodiment of the apparatus illustrating a delayed transport technique;
FIG. 4 is a block diagram associated with the present invention showing the discharge or release devices which total four in associated controller for these devices;
FIG. 5 is a waveform associated with the electronics of the invention in FIGS. 4 and 6; and
FIG. 6 is a schematic block diagram showing the scale weight sensing technique and associated display.
DETAILED DESCRIPTION
Referring now to the drawing, there is shown in FIG. 1, a perspective view of a part of the apparatus of the present invention including framework 10 including a base 12, legs 14, and a top section 16 which comprises means defining a plurality of four hoppers 18. In the embodiment illustrated in FIG. 1 there are four such hoppers that are employed. The framework 10 is disposed about the waste bin 20 which is adapted to contain waste paper discarged in a printing press operation. The waste bin 20 rests upon a scale 22 only a portion of which is actually shown in the perspective view of FIG. 1. The scale 22 may be of conventional design adapted to have some type of a digital readout such as in binary form indicative of weight.
The apparatus disclosed in FIG. 1 may be used with a printing press which typically has four conveyors upon which four different products may be delivered. The good products are allowed to go to stackers or bundlers not specifically described herein and are ultimately stacked on skids for future use or processing. The rejected products are lifted off of the delivery conveyors and placed in the apparatus depicted in FIG. 1. The apparatus in FIG. 1 as indicated previously, has four entry points or hoppers. There is an operator assigned to each delivery of the press and thus each operator is in turn assigned a hopper into which is deposited any waste that occurs at the assigned delivery point.
The apparatus depicted in FIG. 1 may be refered to as a channelizer in that the waste material or waste product is channeled into the waste bin 20 by means of the separate and discreet hoppers. However, the hoppers are not direct conduits into the waste bin but rather, each is furnished with a temporary storage means capable of holding a limited quantity of waste paper such as one or two armfuls.
FIGS. 2 and 3 schematically illustrate two different apparatus for causing the product or material release or discharge. FIG. 2 shows what may be referred to as a metered discharge technique while FIG. 3 illustrates a delayed transport technique. Thus, there is illustrated in FIG. 2 the waste bin 20 and one of the hoppers 18. It is noted that the hopper 18 has associated therewith, a gate 24 which has attached thereto, a piston 26 which may be selectively operated from actuating device 28. The piston and actuating device may be of conventional design. Alternatively, the gate 24 may be substituted by some type of a moving apertured plate arranged to open at the time of discharge and to be closed at all other times.
The metered discharge type of apparatus illustrated in FIG. 2 is quite compact but requires attention as to safety and jamming. In this technique, the hopper may also be provided in an alternate embodiment with a pair of pivoting hopper doors in place of the gate 24. When these doors are closed, they serve as the bottom of the receptacle and hold the material that is being stored. They can be opened by use of electric motors, cylinders as illustrated in FIG. 2 or by other means. When they are open, this allows the material to drop into the waste bin therebelow. The reclosure may be accomplished in a way that would not injure a person nor trap material. For example, the actuating means for the doors may have two levels of operating force. When the doors are closed from a wide open position, a low level of actuating force is employed so that if a hand is introduced, the doors stop moving without applying sufficient force to injure the hand. Sensors determine whether the doors have closed all the way and if the doors fail to close all the way with the low actuating force level, they are reopened to release the trapped material or object. They are then reclosed with the low actuating force. Once the sensor signals that the doors have closed all the way, then a high level of operating force is applied to hold them shut so that material deposited upon them does not force them open.
To provide this dual force level of operation, there may be provided a powering of the shutters or doors with an electric motor that is operated at reduced voltage for closing and full voltage for locking. Alternatively there could be provided a mechanism having a low mechanical advantage that shifts to higher mechanical advantage when it has passed a certain point.
In FIG. 3 there is illustrated the other alternate embodiment wherein there is provided as the delayed transport a conveyor mechanism 30 having associated therewith a control drive 32 schematically depicted in FIG. 3. In the delayed transport technique of the invention as illustrated in FIG. 3, a conveyor is used, such as the conveyor 30, to carry the material towards the discharge opening or hopper 18 illustrated in FIG. 3. When the conveyor is operated, it discharges the material that is on it into the waste bin below. When it is stopped under control of the drive 32, the conveyor functions as a means for storing material for the next discharge cycle. If the stopping of the conveyor is followed by a brief period of reverse motion, as preferred, then any material near the drop off point that might otherwise fall into the waste bin at the wrong time, is moved back by this reverse action, to a stable storage position. Also, the conveyor technique of this invention is readily adapted to be combined with the use of conveyors for long distance transport so that waste discard points may be placed conveniently close to the respective press deliveries with the same conveyor serving also to move the material to the waste bin and to perform the sequential metering function described herein. The press can be controlled to transfer waste to the conveyors automatically in response to signals such as a roll change. This greatly reduces operator involvement.
In selecting the apparatus described in either FIGS. 2 or 3, there are some criteria that should be met such as the fact that the apparatus should be safe to operate with no injury to anyone inserting a hand into the receptacle at any time. The aforementioned dual force operation provides this safety. Also, the apparatus is jam proof and must not be subject to jamming from caught pieces of paper. Also, the operation is such that only one hopper is discharging at a time. At no point during the release and weighing of waste from one receptacle should waste from another receptacle be released. Also, the storage mechanism must be capable of readily receiving waste thrown in during the closure of the receptacle. It is important that papers not be left hanging from the receptacle opening where they could be knocked off during the removal or replacement of the waste bin. It is also desired that the waste bin replacement be accomplished relatively simply. The control for the release is primarily electronic, although it could also be hydraulic and with electronic control it is relatively easy to assure that the operation is mutually exclusive; that is, that only one release occurs at any one time.
FIG. 4 is a simple illustration of the discharge devices identified in FIG. 4 as devices D1, D2, D3 and D4. It is noted that these all couple to a controller C which may include a microprocessor or the like. FIG. 4 simply illustrates that the controller C is adapted to send release signals on the intercoupling lines to the respective devices D1-D4. FIG. 4 illustrates the manner in which these signals are sent. In FIG. 5 there is a clock signal and also four timing signals referred to therein as signals T1, T2, T3, and T4. It is noted that the signals T1-T4 are sequentially spaced. This means that only one of the discharge devices is operated at a time and in accordance with the respective signals. Thus, the timing signal T1 is sent from the controller C to the device D1 to operate it during its time slot T1 which in the illustrative example of FIG. 5, is when the signal is at its pulsed high level form. Thereafter, the device D2 is operated for discharging or releasing under control of the signal T2 and the other two devices are operated sequentially in the same order by the subsequent timing signals.
Now, FIG. 6 shows further control electronics in accordance with the invention. FIG. 6 illustrates the scale 40 which has an output on line 41 representative of the weight on the scale. Digital scales are well known and the output signal on line 41 may in fact be a multi-line signal representative of a count corresponding to weight. This signal is coupled to the difference device 42 which again may be a conventional device in the form of a subtractor or the like device having a clock input and also storage capability. The different device 42 simply stores an indication of the present count and then compares that with a subsequent count under control of the clock. This thus provides an output at the output line 43 from the device 42 that is representative of the increment in weight in the form of an increment count corresponding to the weight added each time that a discharge or release of product occurs from the hopper into the waste bin. In the embodiment of FIG. 6 the device 42 does not distinguish to the origin of the release, but simply provides a difference signal that is coupled by way of line 42 through a magnitude converter 44. The magnitude converter 44 simply provides for any necessary conversion from weight to a count representative of the number of signatures (impressions or sheets or paper). The output signal from the converter 44 couples by way of line 45 to a series of gates Gl, G2, G3, and G4. These are represented in FIG. 6 as AND gates that also receive the respective time signals T1, T2, T3 and T4. Thus, the demarcation of weight increment is carried out by the gates which are mutually exclusively enabled by the respective timing signals. The output of the gates G1-G4 couple to the adders A1-A4 for providing total respective counts to total signatures per stream or separate hopper. The four adders A1-A4 then are shown coupling to the four display devices D1-D4.
In operation, under the control of the microcomputer, the contents of the several receptacles are sequentially released into the waste bin below under control of the signals T1-T4 and the increase in weight associated with each discharge is determined by the circuitry of FIG. 6. These weight increases are each converted by the magnitude converter 44 as mentioned previously to the corresponding number of signatures and the additional timing associated with gates G1-G4 provide for cumulative adding to provide respective waste count totals. Thus, separate waste count totals may be maintained for a plurality of deliveries using a common scale and associated waste container.
By further way of example, during the time T1 when the discharge device Dl is being released, it is noted that the gate G1 is also enabled. Assuming that no race problems exist, then it is only gate G1 that is enabled during that time period and thus any weight increment sensed by the circuitry of FIG. 6 is only added to the adder A1 associated with that time slot. When this addition takes place, the total waste count for that first stream is displayed on the display device D1. In the sequencing, the other totals are also cumulatively added in the same manner.
Having described a limited number of embodiments of the present invention, it should now be apparent to those skilled in the art that numerous other embodiments are contemplated as falling within the scope of this invention.
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A method and apparatus for separately weighing, by means of a common scale, contributions of material from multiple streams, such materials typically being printed papers, such as from a printing press. Material that is to be weighed, which is typically waste material, is loaded into receptacles or the like for temporary storage thereof and is subsequently and sequentially released into a storage bin or the like associated with the common scale. An increase in measured weight associated with each respective material release or discharge is then determined. From each weight increment associated with one of the multiple streams, is added to provide a total count corresponding to weight and associated with each, one of the individual streams of the multiple streams of material. In this way, separate count totals are maintained and continuously updated for a plurality of different corresponding deliveries but using a common scale and associated storage bin or container.
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FIELD OF THE INVENTION
The invention relates to a device permitting at will the use, on a coffee making machine provided for this purpose, of ground coffee or prepackaged cakes of coffee, as well as the removal of the used cakes of coffee.
BACKGROUND OF THE INVENTION
There exist at present on the market two kinds of coffee making machines, one using ground coffee, the other prepackaged cakes of coffee.
In the first case, the ground coffee is disposed in a filter of cylindrical shape, mounted on a filter-carrying cup, fixed pivotally in a bayonet system with helicoidal ramps, located below the cup carrier, whilst ensuring, at the end of the path of movement, the squeezing of a joint, called a cup joint, fitted below the cup carrier such that the hot water cannot escape laterally.
The document DE-A-573.054 has for its object a percolation device adapted to coact with an apparatus for the infusion of coffee by means of a connection, so as to prepare coffee-based beverages in small or large quantities; this device is characterized by the fact that a small or large dish, which comprises a sealed bell, is articulated relative to a pivot carried by the connection, itself provided with a sealing packing.
This earlier document defines the state of the art but is unsuitable for use with cakes containing coffee.
In the second case, on the other hand, the use of prepackaged cakes of coffee requires the use of a filter-carrying cup specially designed for this purpose. To obtain the infusion, the filter-carrying cup, on which the cake is disposed, is introduced into a cylindrical recess comprising throats in the form of helicoidal ramps, specially adapted to the filter-carrying cup. Each ramp is open and permits the introduction of the cup according to a limited angular position. The cake of coffee is encased between two sheets of paper, permeable to liquids, welded together forming a collar useful for gripping the cake of coffee after its infusion.
In known devices of this type, the collar of the prepackaged cake of coffee comprises an extra thickness and renders difficult the introduction of the filter-carrying cup into its cylindrical recess. When the infusion of the coffee is finished, and the filter-carrying cup is withdrawn from its recess, it often happens that the infused cake of coffee remains behind, because its edges bear against the walls of the cylindrical recess and in the helicoidal throats.
Under these circumstances, the user manually picks out the infused cake of coffee at the risk of burning himself, because the cylindrical recess is then at a temperature of about 90° C.
Solutions have been proposed to overcome these drawbacks, by using devices specially designed for this purpose.
There are already known different means permitting using a conventional coffee making machine for the infusion of cakes or tablets of prepackaged coffee, such as those described in the patents DE-A-573 054 and EP-A-0 070 403. An adapter, designed to be secured below the hot water dispenser of the machine, in place of the original filter-carrying cup, comprises at its base devices permitting the mounting by a bayonet system of a filter-carrying cup corresponding to that used in machines for prepackaged cakes of coffee.
Such a solution, which requires having recourse to the juxtaposition of subassemblies of different commercial origin, in addition to the fact that it does not facilitate the use of prepackaged cakes of coffee in conventional coffee machines, renders the latter less useful; and in addition it does not resolve the problem raised by the extraction after infusion of the cakes soaked with boiling water.
The document EP-A-0 555 775 provides a sliding system provided with a receptacle with a filter for an espresso coffee making machine, which comprises a cylindrical body with inclined annular surfaces, provided with a handle, the cylindrical body being adapted to turn to raise or lower itself on corresponding inclined surfaces of a structure of box shape. During raising, the cylindrical body raises the receptacle with its filter, without rotation, against a fixed structure, which it faces, said receptacle being thus subjected to a linear movement without rotation. The fixed structure is a toric joint, provided with a lower circular groove and an upper circular groove for better sealing, at the upper edge of the receptacle.
The system for raising or lowering the cylindrical body uses the coaction of several surfaces having inclined surfaces. In addition to problems of production and the cost of production, there is the possibility of very strong gripping during these rising and falling movements; moreover, the introduction of said cylindrical body into the box-shaped structure is not easy.
SUMMARY OF THE INVENTION
The present invention has for its object to overcome these drawbacks. This invention, as it is characterized, solves the problem consisting in creating a device permitting at will the use, in a coffee machine designed for this purpose, of ground coffee or prepackaged cakes of coffee, as well as the mechanical extraction of the infused cakes of coffee.
The device permitting using at will, in a coffee making machines, ground coffee or prepackaged cakes of coffee, as well as the mechanical extraction of the infused cakes of coffee, according to the invention, comprises a filter-carrying cup fixed below the cup carrier by means of a bayonet system constituted of helicoidal projections, diametrically opposed, located on the sides of the filter-carrying cup, and shouldered axles fixed below the cup carrier such as are described in French patent application No. 95/01961, is characterized, principally, in that the cup carrier comprises, either a recess with a shower for prepackaged cakes of coffee, or a removable packer with a shower, of a shape suitable to those of the filters for ground coffee, whose upper portion matches the shape of the recess which remains in the cup carrier; in that the filter-carrying cup can be provided as desired either with a filter for ground coffee or with a filter adapter supporting a filter for cakes of coffee, in that, in the second case, the filter-carrying cup is fixed by its base in bezel, articulated relative to one of the shouldered axles, whose clearance is limited by an abutment fixed below the other shouldered axle, in that said articulated bezel comprises, on its upper side, an ejection finger located such that during pivoting of the articulated bezel, its upper end describes an arc of a circle passing through the space for the cake of coffee, in that the cup joint comprises, in the prolongation of its external surface and toward its center, a tapered annular lip, of an internal diameter slightly less than the external diameter of the prepackaged cake of coffee.
According to one embodiment, the adapter is constituted by a cup of truncated conical shape, axially perforated, bearing on a rim provided for this purpose in the filter-carrying cup, whose upper surface comprises a recess delimited radially by an annular edge of a diameter and cross section corresponding to that provided at the periphery of the cake-bearing filter and matching the form of the latter.
For purposes of sealing, the mean diameter of the annular edge, provided on the upper surface of the cup and on the periphery of the filter-carrying cup, is greater than the internal diameter of the cup joint.
The abutment limiting the clearance of the articulated bezel, in which is received the base of the filter-carrying cup, comprises a flat portion, parallel to the plane passing through the shouldered axles. The articulated bezel bears on this flat surface of the abutment, via a tongue to which it is fixed.
According to one embodiment, the tongue is retained and urged against the abutment by a magnet received in the tongue or the flat surface of the abutment. In the first case, the abutment is made of metallic metal.
The ejection finger of the cake of coffee, after infusion, is fixed on the upper surface of the articulated bezel, beyond the radius of gyration of the helicoidal projections of the filter cup, at a distance from the axis of articulation of the bezel greater than that separating said axis from the edge of the prepackaged cake of coffee.
To facilitate loosening the edge of the cup, after infusion, the height of the ejection finger is determined such that the upper end of the latter must be received in a plane parallel to the external surface of the joint of the cup located just a little below this latter.
The advantages obtained, thanks to this invention, consist essentially in that the coffee making machine may be rapidly and simply adapted to the use of ground coffee or prepackaged cakes of coffee, that the cake of coffee is easily emplaced, that the mechanical ejection of the infused cake of coffee avoids any risk of burning the user and that the combined displacement of the filter-carrying cup is obtained by a single movement applied to the handle.
BRIEF DESCRIPTION OF THE DRAWINGS
Other characteristics and advantages will become apparent from the description which follows of one embodiment of a coffee making machine according to the invention, given by way of non-limiting example with respect to the accompanying drawings.
FIG. 1 is a front cross-sectional view of the device, adapted for prepackaged cakes of coffee.
FIG. 2 is a top plan view of the device according to FIG. 1.
FIGS. 3-8 show the operation of the device according to FIGS. 1 and 2 and its mechanical ejection system for the infused cakes of coffee.
FIG. 9 is a front cross-sectional view of the device adapted for ground coffee.
FIG. 10 shows a fragmentary perspective view of a coffee making machine provided with the device according to the present invention, during emplacement of the filter-carrying cup on the articulated bezel.
FIG. 11 is a side view of the device according to the invention, the assembly of its constituent pieces being shown in an exploded view.
FIG. 12 shows a detailed enlarged cross-sectional view of the infusion chamber enclosing a prepackaged cake of coffee.
Finally, FIG. 13 shows in a cross-sectional view a cake of coffee used with one of the embodiments of the invention.
DETAILED DESCRIPTION OF THE INVENTION
The drawings show a device according to the invention permitting as desired the use, in a same coffee making machine, of ground coffee (FIG. 9) or prepackaged cakes of coffee (other figures), comprising a filter-carrying cup 10, a sleeve 16, provided with helicoidal lateral projections 11 and 12 adapted to bear on shoulders 31 and 41 of shouldered axles 30 and 40 fixed below the cup carrier 20.
The cup carrier 20 is shown in FIG. 12 and is provided with a removable shower 21, fixed by a screw 22 in the bottom of a recess 23 reproducing the shape of a prepack aged cake of coffee 50, with an edge 51, disposed below the shower 21 and a metallic filter 60, with an annular edge 61, matching the shape of the cake of coffee 50 which it supports, received on the annular edge 72 of a dish 70 with a recess 71, resting on the internal rim 13 of the filter-carrying cup.
The filter-carrying cup 10 is received by its base within a bezel 80 articulated relative to a screw 32, see FIGS. 1 and 11, mounted below the left shouldered axle 30 and bearing at the end of its movement, by means of a tongue 81, against an abutment 42 with a flat 43, fixed below the right shouldered axle 40; said tongue 81 comprising a magnet 82, directed toward the flat 43 of the abutment 42, and said bezel 80 being provided with an ejection finger 83 for the infused cake of coffee retained by the tapered lip 25 of the cup joint 24 fixed below the cup carrier 20.
Examining now in greater detail FIGS. 1 and 2, it will be noted that the filter-carrying cup 10, given its reception in the bezel 80 articulated relative to the left shouldered axle 30, as is shown in FIG. 10, is thus perfectly maintained and presented during its engagement below the cup carrier 20, with a precise position, at the end of its movement, along the axis of the cup carrier 20, following contact of the tongue 81 against the abutment 42 fixed below the right shouldered axle 40; this presentation being effected by action on the sleeve 16 of the filter-carrying cup 10, it suffices to maintain and to increase the force exerted on the sleeve 16 to the right to obtain the progressive engagement of the helicoidal projections 11 and 12 on the shoulders 31 and 41 of the shouldered axles 30 and 40, causing the sliding upwardly of the filter-carrying cup 10, relative to the articulated bezel 80, giving rise at the end of the movement to blocking of the cake of coffee 50 between the shower 21 of the cup carrier and the metallic filter supporting the cake 60, as well as the pinching of the cup joint 24 by the annular edge 61 of the metallic filter 60 and the lateral tightening of the cake of coffee 50 by the tapered lip 25 of the cup joint 24, received in the base of the cup carrier 20.
The seal being thus ensured, infusion can begin by ejection of water at a suitable temperature through the conduits 26 and 27 of the cup carrier 20 opening above the shower 21: water which will thus be forced through the cake of coffee 50, ultimately to flow through the axial opening 73 of the dish 70, then into the distributing nozzle 17 located below the filter-carrying cup 10.
The infusion being completed, it suffices, to obtain the disengagement of the cake of coffee 50 and the return into initial position of the filter-carrying cup 10, to exert a force to the left, on the sleeve 16 of this latter to obtain first of all the return of the latter into the bezel 80 and the disengagement of the cake of coffee 50 which remains retained by the tapered lip 25 of the cup joint 24; the filter-carrying cup 10 again resting against the upper surface of the bezel 80, it suffices to exert a longitudinal action on the sleeve 16 to overcome the attractive force exerted by the magnet 82 on the abutment 42 and to obtain the forward pivoting of the bezel 80, whose ejection finger 83, during its movement, comes into contact with the edge 51 of the cake 50, which it loosens by exerting an action which causes the latter to fall into a receptacle (not shown), located below the device, then, in the interval, the rear edge of the bezel 80 separates from and passes beyond a vertical from the cup carrier 20.
Referring now to FIGS. 3 to 8, showing the operation of the device, it will be noted that, as has already been explained above, the cake 50 is first placed on the metallic filter 60, located in the lower portion of the filter-carrying cup 10 (FIGS. 3 and 4), and movement toward the right is exerted on the sleeve 16 of said cup, until the tongue 81 comes into contact against the abutment 42 (FIG. 5). The action on the sleeve 16 is then continued and intensified to obtain the blocking of the cake 50 in the recess of the cup carrier 20 (FIG. 6). To obtain the disengagement of the filter-carrying cup 10, then the mechanical ejection of the cake of coffee 50, it suffices to exert on the sleeve 16, an action in the reverse direction, to obtain the disengagement of the cake of coffee 50 (FIG. 7) then the ejection of said cake under the action of the finger 83 (FIG. 8).
Finally, referring to FIG. 9, it will be noted that, to use ground coffee, it suffices first to withdraw the metallic cake-carrying filter 60 and the dish 70 of the filter-carrying cup 10 and the replace them by a conventional cylindrical filter 62, then to withdraw the shower 21 and to replace it with a packer 63, with a shower 64, whose upper portion matches the shape of the recess 23 for prepackaged coffee cakes 50. The device then functions according to French patent application No. 95/01961.
It will be noted that, no matter what the selected version, the adaptation of the machine is simple and within the skill of the user, because the only tool needed is a simple screwdriver.
The operation of the device is shown in FIGS. 3 to 8.
In FIG. 3, the bezel 80 is in offset position relative to the cup carrier 20 on which are present the shouldered axles 30 and 40. This arrangement facilitates the emplacement of the filter-carrying cup 10 relative to said bezel 80.
In FIG. 4, it is easily seen that in this position, identical to that of FIG. 3, it is very easy to emplace the prepackaged cake of coffee 50 above the dish 70 contained in this filter-carrying cup 10.
In FIG. 5, the assembly constituted by the bezel 80, the filter-carrying cup 10 and the cake 50 can be moved rotatably in the direction F3, about the left shouldered axle 30, until the tongue 80 comes into contact with the abutment 42 and is immobilized in this position by means of its magnet 82. At this time, said cup 10 is located below and relative to the cup carrier 20 and the lateral helicoidal projections 11 and 12 are in contact with the shoulders 31 and 41.
In FIG. 6, the gripping according to F1 of the filter-carrying cup 10 against said cup carrier 20 to permit the infusion, takes place by a simple displacement of the sleeve 16 of the cup 10.
In FIG. 7, the ungripping according to F2 is a reverse movement to that described in FIG. 6.
Similarly, and according to FIG. 8, rotation according to F4 is a reverse movement of that described in FIG. 5.
The object of the invention is hence to facilitate the positioning of the filter-carrying cup 10 below the cup carrier 20 and the gripping and ungripping to permit infusion.
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A ladle holder (20) comprises either a releasable spray packing member for ground coffee or a spray recess for pre-packaged coffee blocks, and a filter ladle (10) may be provided as required with either a ground coffee filter or a filter adaptor (70) for coffee blocks. In the latter case, the filter ladle (10) fits into a holder with an upper ejector pin (83) for ejecting used coffee blocks. The holder is hinged to one bearing pin (30) and, when fully inserted, engages an abutment under the other bearing pin (40) by means of a tab. The two bearing pins (30, 40) engage helical projections (11, 12) on the filter ladle (10) to form a bayonet-like attachment and position the filter ladle (10) in engagement with a ladle seal.
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BACKGROUND OF THE INVENTION
The present invention relates to the electrolytic reduction of alumina to aluminum metal, and more particularly, to a modified Hall-Heroult process for producing aluminum.
U.S. patent application Ser. No. 374,802, filed June 28, 1973 for an ALUMINA REDUCING PROCESS, issued Dec. 3, 1974, as U.S. Pat. No. 3,852,173 describes a new process for producing aluminum metal along the lines originally set forth by Hall and Heroult. The particular examples set forth in that application are characterized by electrolytic cells possessing covers for the purpose of obtaining improved recovery of fumes and for the purpose of maintaining a molten electrolytic bath surface to which alumina is fed directly.
SUMMARY OF THE INVENTION
It is an object of the present invention to provide a process making unexpectedly advantageous use of certain of the novel features set forth in the above-mentioned U.S. Pat. No. 3,852,173 for operating the more conventional Hall-Heroult cell which lacks a cover and which is characterized by a crust over its bath.
Another object of the invention is to provide process parameters which lead to acceptable production of aluminum at lower bath operating temperatures and consequently lower fume production and higher current efficiency. While a cell provided with a cover is one solution to the collection of fumes produced during the electrolytic production of aluminum, it would be desirable to be able to operate a conventional, crusted cell with reduced fume evolution, in order to reduce the cost of capturing and recycling the same.
This, as well as other objects, which will become more apparent in the discussion that follows, are achieved, according to the present invention, by providing a process for producing aluminum, which process conventionally includes electrolytically decomposing alumina to aluminum metal in a molten electrolyte bath between a carbon anode and a cathodic interface formed between a molten aluminum metal pad and the electrolyte bath, the bath
A. being predominantly NaF and AlF 3 ,
b. containing CaF 2 and Al 2 O 3 , and
C. being covered by a frozen crust,
The improvement comprising providing in the bath 5 to 10 weight-% LiF, while maintaining in the bath a weight ratio NaF to AlF 3 of 1.04 to 1.15, and while maintaining a frozen layer bounding the sides of the aluminum metal pad and bath.
As indicated above, the improvement in the process of the present invention includes the combined features of a particular lithium fluoride content and a particular weight ratio of sodium fluoride to aluminum fluoride. Typically, the combined weights of sodium fluoride and aluminum fluoride will make up at least 75% of the bath. Calcium fluoride comes into the bath in company with the charged alumina. It has been found that the calcium fluoride will reach a level of from, for example, 3 to 6 weight-% and then remain constant at that level, despite it being continually added with new alumina charge. The alumina content in baths operated according to the present invention will typically analyze from 2.5 to 5 weight-%. Magnesium fluoride is also typically present in baths used according to the present invention; its level is typically from 0.2 to 0.4 weight-%.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an elevational, cross-sectional, broken-away view of a Soderberg-anode-type cell for use in the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
With reference to FIG. 1, there is shown a cell which is essentially that shown in the FIG. 1 of the above-mentioned U.S. Pat. No. 3,852,173, with the cover removed.
The cell of the present FIG. 1 represents a preferred cell for carrying out the present invention. The presence of graphite block in its side wall enables it to have a greater heat loss, sideways in FIG. 1, to the environment. This means that greater production of aluminum metal can be obtained, because a greater amount of current can be passed through the cell while yet maintaining the frozen layer of alumina and bath.
While it is preferred to use the cell of FIG. 1, a particular advantage of the present invention is that conventional Hall-Heroult cell constructions can be used for the process herein described. All that is necessary is that the bath chemistry be adjusted to conform to the present invention and that electrical current and/or voltage be adjusted until probing indicates the presence of the desired frozen layer of alumina and bath.
Concerning now the details of FIG. 1, the cell includes a steel shell 10 containing appropriately placed insulating and conducting materials, a molten aluminum metal pad 11 and an electrolyte bath 12. The bath level is at 12a, while anode gas (primarily CO 2 ) bubbles appear at 12b. Suspended in bath 12 is a Soderberg anode 13. Associated with the Soderberg anode are steel spikes 14a, 14b, and 14c, which are connected to the positive side of a source of electrical current. As is well known, a steel jacket 15 is provided on the upper sides of the anode, where the anode constituents have not yet hardened sufficiently to render themselves self-supporting.
Surrounding the anode is a manifold 16 whose purpose is to provide an upper side for the crust and to promote fume collection through a conventional exhaust burner (not shown).
As mentioned above, this cell is distinctive in that it contains graphite block 17, for example of thickness of 5-inches as measured left and right in FIG. 1, as the material contacting the outer perimeter of the electrolyte bath. Arranged between graphite block 17 and steel shell 10 is mica mat 18 for the purpose of providing an extra degree of safety against current flow through shell 10. Mat thicknesses of from 6 to 20 mils have been used.
The pad 11 of molten aluminum is supported on carbonaceous block lining 19 and carbonaceous tamped lining 20. The carbonaceous linings are supported on an alumina fill 21, there being interposed between the tamped lining and the fill some quarry tile 22. A layer of red brick 23 is situated between the graphite block 17 and the quarry tile 22.
FIG. 1 is a representative vertical section through the cell and it will be realized that, for instance, similar graphite block 17 will appear in other elevational sections through the cell.
The cathode current is supplied through steel connector bars, such as bar 24, to the block lining 19. The current supply is indicated by plus and minus signs on the anode and on connector bar 24 respectively.
A deck plate 25, provided on the upper edge of steel shell 10, serves, among others, the purpose of protecting graphite block 17 when the crust is being broken in for the purpose of feeding additional alumina to the bath 12.
Alumina is charged from hopper 26, which has a suitable opening-closing mechanism 27 on its lower side.
According to the present invention, a crust 28 is present. This crust is formed, above, of loose particles 29a of alumina and, as required, electrolyte make-up chemicals. On its lower side, the crust becomes, in part, a sintered alumina-rich material 29b.
Operating parameters are selected such that a frozen layer 30 of alumina and bath bounds the sides of the aluminum metal pad 11 and bath 12. It is preferred that layer 30 extend at least down to the bottom of the slope of tamped lining 20, i.e. to beneath the side of anode 13, although in actual practice it may extend to a point 30a, for example, four inches inwards from the projection of the side of anode 13 onto the cell bottom without there being any significant limiting of the electrical current flow area at the interface between pad 11 and lining 19. This frozen layer acts as a steadily-feeding source of alumina into the bath for electrolysis and as a barrier to the flow of electrical current from the anode, through the shell 10 to the cathode bar 24.
In actual practice, it has been found that it is advantageous when there exists at the frozen layer a mushy transition region 31, which is made up of bath and suspended particles of alumina. This transition region 31 between the completely molten bath 12 and the frozen sidewall 30 tends to be formed as a matter of course by the conventional practice of breaking crust 28, for example for the purpose of replenishing alumina in the bath or, in the extreme, for extinguishing an anode effect. When this transition region exists, it steadily feeds alumina into solution and makes up for that which is electrolytically decomposed in the building-up of pad 11.
Although the existence of transition region 31 has been found to be very advantageous, it is not necessary that such be the case in order to have a successful process according to the invention. For example, alumina can be fed from bath-exposed alumina-rich regions in the frozen layer 30. Also, it is possible to add to the bath an alumina of high solubility, such as that disclosed in U.S. patent application Ser. No. 374,805, filed June 28, 1973 by W. C. Sleppy for a NOVEL ALUMINA FEED FOR ALUMINUM CELL, issued Oct. 1, 1974, as U.S. Pat. No. 3,839,167.
When applying the present invention to a pre-baked anode type cell fed at gaps between anodes, metal grade alumina may be fed into the bath at a rate substantially not exceeding its rate of solution by supplying it around a pneumatic plunger such as disclosed in U.S. Pat. No. 3,681,229, issued Aug. 1, 1972, to R. L. Lowe.
Feeding at the side of either a Soderberg or a prebake cell can be done by breaking-in the crust, for instance crust 28 in FIG. 1. It is then possible to use large amounts of metal grade alumina in a transition region 31 for steadily feeding alumina into solution without mucking the cell.
Further illustrative of the present invention are the following examples:
EXAMPLE I
A Soderberg cell was operated for producing aluminum with an anode to cathode distance, i.e. the distance between the bottom of the anode and the top of the metal pad, of 13/4 inches and a current flow of 66,000 amperes. The bath composition was, neglecting impurities, in weight-%, 3.5% CaF 2 , 3.5% Al 2 O 3 , 40% AlF 3 , 10% LiF, 42.5% NaF and 0.25% MgF 2 . The calculated weight ratio NaF/AlF 3 (the "cryolite ratio") for this composition is 1.06. The cell was operated at a temperature of 930° C with a bath depth of 11 inches and a minimum metal depth of 7 inches, average 8 inches. The feed to this cell was alumina which had been heated in a kiln to a water content characterized by a Loss On Ignition (LOI) of 41/2%, where Loss On Ignition is defined as the weight loss on heating from 300° to 1100° C. Feeding of alumina was by breaking-in the crust at the side of the cell.
EXAMPLE II
Example I was repeated with the difference that the alumina feed was an alumina conventionally used for aluminum metal production. This alumina is referred to in the trade as "metal grade alumina". The particular metal grade alumina used for this example had a Loss On Ignition of 0.75%. It was found that the crust formed when using metal grade alumina was better adapted for preventing fume leakage than was the higher LOI alumina used in Example I.
EXAMPLE III
A line of cells, referred to as a "pot line", of the Soderberg type was operated for 324 pot-days, produced 327,416 pounds of aluminum and 1010.5 pounds net aluminum per pot-day, and yielded an aluminum product of 99.73% aluminum at an electrical current efficiency of 89.7%. Electrical power consumption was 7.90 kilowatt hours per pound of aluminum. Operation was maintained at 0.646 anode effects per pot-day. The pounds of Soderberg paste consumed per pound net aluminum was 0.587. Consumption of aluminum fluoride was 12,310 pounds, while Li 2 CO 3 consumption was 5,338 pounds. The anode to cathode distance was between 13/4 and 2 inches. At this time, operation was changed over from the higher-water-content alumina of Example I to metal grade alumina of 0.75 LOI. The feed for two-ninths of the period was the higher-water-content alumina of Example I and the feed for the remainder of the period was metal grade alumina. The technique of feeding was again by breaking-in the crust at the sides of the cells. Volts per pot was 5.24, average amperes 63,474, and kilowatts per pot 333.9. The bath composition was, in weight-%, 3.63% CaF 2 , 3.99% Al 2 O 3 , 39.8% AlF 3 , 9.52% LiF, 42.03% NaF and 0.28% MgF 2 . The calculated weight ratio NaF/AlF 3 was 1.06. Bath operating temperature was 934° C.
EXAMPLE IV
For 1,404 pot-days of operation in Soderberg cells, a total of 1,460,300 pounds of aluminum were produced, the pounds net aluminum per pot-day being 1,040.1. Aluminum of 99.73% purity was obtained, with an electrical current efficiency of 93.7% and 7.72 kilowatt hours of electrical energy consumed per pound of aluminum. Operation was at 0.518 anode effects per day. Soderberg paste consumption was 0.608 pounds of paste per pound net aluminum, with AlF 3 consumption lying at 78,680 and Li 2 CO 3 consumption at 15,804. Pot electrical data included a 2-inch anode to cathode distance, 5.35 volts per pot, 62,509 amperes current load, and 334.4 kilowatts per pot. The lithium fluoride content of the bath was, in weight-%, 7.05% with the cryolite ratio (weight-ratio NaF/AlF 3 ) lying at 1.08. Operating temperature was 938° C, and metal grade alumina of 0.75 LOI was utilized, fed by breaking-in the crust at the sides of the cells.
EXAMPLE V
For 4,070 pot-days of Soderberg cell operation (i.e. 131.3 pots for 31 days), 4,139,655 pounds of aluminum were produced for an aluminum production per pot-day of 1,017.1 pounds net aluminum. The aluminum purity was 99.74%, with current efficiency lying at 87.9% and power consumption, kilowatt-hours per pound of aluminum equaling 8.37. Operation was at 0.64 anode effects per day. Materials consumption was 0.505 pounds Soderberg paste per pound net aluminum, 52,800 pounds of cryolite, 177,454 pounds of aluminum fluoride, and 21,499 pounds of lithium carbonate. Electrical parameters were an anode to cathode spacing of 2.3 inches, 5.44 volts per pot, 65,200 amperes of electrical current passing through each pot, and 355 kilowatt hours power per pot. The composition of the electrolyte bath was, in weight-%, 3.66% CaF 2 , 2.97% Al 2 O 3 , 41.8% AlF 3 , 5.08% LiF and 0.35% MgF 2 . The weight ratio NaF/AlF 3 was 1.14. Operating temperature was 939° C. Metal grade alumina of 0.75 LOI was used, fed by breaking-in the crust at the sides of the cells. Bath depth was 10.5 inches, and the average peak metal depth before tapping was 9.7 inches.
EXAMPLE VI
For 4,215 pot-days (136 pots for 31 days) of operation of a Soderberg pot line, 4,170,735 pounds of aluminum were produced, giving a pounds net aluminum per pot-day figure of 989.5. Aluminum purity was 99.75%. Electrical current efficiency was 89.8%, with 8.05 kilowatt hours of electrical energy being consumed per pound of aluminum produced. Operation was at 0.57 anode effects per day. Materials consumption was 0.519 pounds Soderberg paste per pound net aluminum, 48,682 pounds of cryolite, 207,836 pounds of aluminum fluoride and 33,593 pounds of lithium carbonate. Electrical parameters were an anode to cathode distance of 2.16 inches, 5.34 volts per pot, a current flow of 66,100 amperes through each pot, and 332 kilowatts per pot. Bath composition was, in weight-%, 3.46% CaF 2 , 3.90% Al 2 O 3 , 41.9% AlF 3 , 6.47% LiF and 0.27% MgF 2 . The weight-ratio NaF/AlF 3 was 1.12. Operating temperature was 936° C, with metal grade alumina of 0.75 LOI being the cell feed, the feeding being accomplished by breaking-in the crust at the sides of the cells. Electrolyte bath depth was 10.4 inches, and the average maximum metal depth, i.e. the peak depth before tapping, was 9.4 inches.
It will be understood that the above description of the present invention is susceptible to various modifications, changes, and adaptations and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.
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In a process for producing aluminum, which process conventionally includes electrolytically decomposing alumina to aluminum metal in a molten electrolyte bath between a carbon anode and a cathodic interface formed between a molten aluminum metal pad and sides electrolyte bath, the bath
A. being predominantly NaF and AlF 3 ,
b. containing CaF 2 and Al 2 O 3 , and
C. being covered by a frozen crust,
The improvement including providing in the bath 5 to 10 weight-% LiF, while maintaining in the bath a weight ratio NaF to AlF 3 of 1.04 to 1.15, and while maintaining a frozen layer bounding the sizes of the aluminum metal pad and bath.
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FIELD OF THE INVENTION
The present invention relates to anti-theft devices, and in particular, to the securing of flanged objects such as accessories or components of industrial machines, which are often bolted to surfaces of such machines. In particular, the device covers and prevents unauthorized removal of a valuable object relative to the surface to which it is attached, additionally preventing access to bolts or other attachment devices securing the object to the surface.
BACKGROUND ART AND PRIOR ART STATEMENT
A number of devices have been disclosed for preventing the theft of objects usually attached to, and easily removable from, other equipment by means of bolts or screws. Most of these prior art devices are directed to preventing the theft of communications equipment from vehicles, and accomplish their objective by preventing access to the bolts or attachment means by which the communications equipment is mounted. U.S. Pat. No. 3,410,122 to Moses discloses cover elements which interlock with a mounting bracket to cover the securing means on an object so as to prevent unauthorized removal from the mounting bracket. The Boll patent (U.S. Pat. No. 3,665,739,) provides an anti-theft device for locking an internal combustion engine to a mating transmission. This device is primarily intended for use on a Volkswagon-type vehicle, and involves replacing one of the bolts with the device of the invention which, when the padlock is attached, cannot be removed. U.S. Pat. No. 3,595,041 to Leeper discloses a device comprising hollow side arms for receiving and covering the bolts used to attach communication equipment to a mounting bracket, these arms being locked in place by means of a chain or hinged arms which are secured in tension by means of a padlock. U.S. Pat. No. 3,945,227 to Reiland discloses a hinged bracket surrounding the communications device, the hinged arms are adapted so as to swing into place covering the attachment bolts for the communications device, and being locked into place by means of a padlock. U.S. Pat. No. 4,038,843 to Daley, Jr., discloses another hinged bracket in which hinged portions of the side arms double back upwardly, along the sides of the communications device covering the attachment bolts, and are fastened at their upper end by means of a long bolt running across the top of the communications device.
None of these prior art patents deal with the securing of a flanged object to the surface upon which it is attached, nor are they capable of being adapted to the protection of industrial machinery and equipment.
SUMMARY OF THE INVENTION
In accordance with the present invention, an anti-theft device is provided including a cover assembly comprising cover bars overlying the bolts or other devices by which the flanged object is attached to the adjacent surface, and one or more optional slide obstructor bars connecting the cover bars. The cover bars engage with a securing assembly comprised, in one embodiment, of securing bars which are bolted to the flanged object and to the underlying surface. The same bolts are used in bolting the object and surface together. The cover bars are flanged to cover and prevent access to the bolts, and to allow engagement with the cover assembly. The securing assembly may also include a slide obstructor bar rigidly connecting the securing bars at one end. This slide obstructor may be L-shaped, having a vertical component. After the securing assembly has been mounted, the cover assembly is slid into place, U-shaped flanges on the cover bars slideably engaging with the flanges on the securing bars. There are vertical plates on the front portion of the slide obstructor bar of the sliding cover assembly, one of which contains a padlock hole designed to slide into register with a similar hole on the vertical portion of the securing assembly slide obstructor bar. A padlock is inserted through both holes and locked.
In another embodiment, there is no vertical component either to the obstructor bar on the securing assembly or to the cover assembly, the securing assembly slide obstructor bar lies in the same plane as the securing bars. Instead, padlock holes are drilled in one of the cover bars and one of the securing bars, so that they are in registry when the cover assembly has been slid into place over the securing assembly.
In still another embodiment, the cover bars comprise rectangular tubes or channels, with holes on their undersides to accommodate the heads of the bolts by which the flanged object is attached to the adjacent surface. The cover bars include vertical members extending downward to cover the sides of the flange of the object to be secured, and prevent access to the bolts. Retaining loop(s) extend over and between the cover bars to surround the object to be secured and one or more slide obstructor bars also interconnect the cover bars. This cover assembly can be secured by means of a securing strap attached to the cover assembly, which strap is placed about the circumference of the adjacent object upon which the flanged device is mounted. A toggle device is used to secure the strap and prevent its movement, a padlock being used to lock the toggle device into place and prevent loosening of the strap.
Based on the foregoing description, the present invention meets a number of worthwhile objectives. A cover device is provided to prevent the removal of valuable flanged objects from surfaces to which they are mounted or attached, the device preventing access to the bolts or other devices by which the valuable object is attached to the surface, so as to prevent its unauthorized removal. The device of this invention, when locked into place, prevents the movement of the valuable object relative to the adjacent surface in any direction, so that it cannot be removed without authorization.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the anti-theft device of the present invention shown locked in place over the object to be protected;
FIG. 2 is a perspective view with the cover assembly slid back;
FIG. 3 is a cross-section view taken along lines 3--3 of FIG. 1;
FIG. 4 is an exploded view showing the flange cover and securing bars;
FIG. 5 is a perspective view showing a starting motor attached to an engine protected against theft by the device of this invention;
FIG. 6 shows a second embodiment of the invention protecting the starting motor of FIG. 5;
FIG. 7 is a cross sectional view taken along lines 7--7 of FIG. 6;
FIG. 8 is a partial side view of the invention showing the securing strap; and
FIG. 9 is a partial sectional view taken along the lines 9--9 of FIG. 8.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In accordance with this invention, a valuable object 10, such as a starter motor, generator or battery, having a flanged base 12 adjacent to the mounting surface 14 of a second object 18, as best seen in FIG. 5, is secured to said surface by means of a securing assembly 20. The securing assembly 20 comprises a first securing bar 22 positioned overlying one side or portion of the flange 12, and a second securing bar 24, overlying the flange 12 on the opposite side of the object 10. The securing bars have bolt holes or slots 26, spaced so as to accommodate the bolts 16 by which the object 10 is secured to the surface 14. The securing bars 22, 24 have vertical flanges 28, 29 respectively, along their outer edges extending downward almost to the surface 14 to prevent access to the bolts 16. The securing assembly may have a first slide obstructor bar 30 connecting the securing bars, and preventing the assembly from sliding past the valuable object 10 in one direction. The slide obstructor bar may have a vertical component 34 designed to abut a vertical component of the cover assembly as will be pointed out hereafter. The slide obstructor bar 30 includes a hole 32 to accomodate a padlock or other locking means, and placed so as to be in registry with a similar hole on the cover assembly as hereinafter described.
The invention also includes a cover assembly 40 comprised of a first cover bar 42 adapted to overlie flange 12 and first securing bar 22, and a second cover bar 44 spaced apart from the first cover bar and adapted to overlie the other side of flange 12 and second securing bar 24. The cover bars are equipped with U-shaped flanges 46, 47 extending vertically from their outer edges, forming a channel to accommodate flanges 28, 29, respectively, of the securing bars, so that the cover assembly may be slid into place on the securing bars. The cover assembly is also equipped with retaining loop or loops 48, 49 the ends being joined to the first and second cover bars, 42 and 44, respectively. The looped portions are adapted to extend over the object 10. In addition, at the anterior end of the cover assembly, this being the leading end when the cover assembly is slid into place on the securing assembly, there may be vertical upright member(s) 50, 51 designed to abut with the vertical portion 34 of the first slide obstructor bar when the cover assembly is in place on the securing assembly. One of these upright members 50 includes a padlock hole 52 designed to be in registry with padlock hole 32 in the upright members 34 when the device is assembled, and through which padlock 56 is placed. In addition, the cover assembly may be equipped at its posterior end with a second slide obstructor bar 54, if desired, to prevent forward movement of the cover assembly relative to the object 10.
In another embodiment of this invention, as best seen in FIG. 6, a modified cover assembly 60 comprises a first and second cover bar, 61 and 62, in the form of a rectangular channels, the bottoms of which are formed with bolt holes 63 to accommodate the heads of the bolts 16 attaching the object 10 to the surface, so that the heads extend up into the space inside the channels of the cover bars 61 and 62, and access to the bolts is prevented. A slide obstructor bar 66 connects the modified cover bars and prevents movement of the modified cover assembly past the object to be protected. Each cover bar is equipped with a vertical flange 64, 65, respectively, on its outer edge extending vertically downward to surface 14, to prevent access to bolts 16 from the sides. Flanges 64, 65 are equipped with hinged attachments 68, 69 for securing strap 70 which extends around the outer perimeter of second object 18 to which the valuable object 10 is attached. Strap 40 is equipped with tightening means such as a toggle mechanism comprising toggle lever 72 and toggle engagement 74, adapted so that when the toggle lever 72 is in its closed position, no slack remains in strap 70, and relative movement of object 10 with respect to second object 18 is prevented. The toggle lever 72 has a padlock hole 76 designed to be in registry with a padlock hole 78 in lock flange 79 in the closed position, so that padlock 56 may be secured therethrough to prevent removal of strap 70. It is to be understood that the embodiment shown in FIG. 6 with the addition of a cross bar across the open legs of cover bar 61, 62 is useful not only in connection with objects secured to surfaces by means of bolts, but also by other attaching means, as well as those which merely rest upon or abut against adjacent surfaces of another object.
Another embodiment of the invention is shown in FIG. 4. A padlock hole 51 may be positioned in the end of securing bar 24 so as to be in registry with a second padlock hole 53 in cover bar 44 when the anti-theft device is assembled. It should also be evident that securing flange 29, U-shaped engaging flange 47 and flange 12 on the object to be protected must all be of a height compatible with each other.
The anti-theft device of this invention prevents access to the attachment means by which a valuable object is attached to an adjacent surface and/or obstructs relative movement of the valuable object with respect to the surface against which it rests, thereby preventing the unauthorized removal of the object without a key or combination to the locking means.
It is apparent that various modifications and changes can be made, e.g. in size, shape and materials of construction, in order to accommodate the sizes and shapes of the objects to be secured and surfaces to which they are to be secured, without departing from the spirit and scope of the invention.
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An anti-theft device to prevent the unauthorized removal of a mounted, flanged object comprising a cover overlying the mounting flanges of the object, a securing device for attaching the cover to the surface upon which the flanged object is mounted and a locking device for preventing removal of the cover from the securing device. The invention is particularly useful in remote oil field and other field uses to prevent theft of industrial machine accessories such as starters, generators, and batteries.
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BACKGROUND OF THE INVENTION
This invention relates to a thrust bearing assembly for a horizontally disposed rotatable shaft.
Many types of thrust bearings have been used in the past for absorbing the axial thrust of a rotatable shaft. Ball, roller or needle bearings have been used with significant success. An example of the use of needle bearings is described in U.S. Pat. No. 3,393,025 to Jenkins, assigned to the General Electric Company, assignee of the present invention. In applications calling for shafts rotating at a relatively high speed on the order of several thousand revolutions per minute this type of bearing may become noisy since under certain loading conditions which occur intermittently during motor operations the needles tend to skid rather than roll. In addition, this type of arrangement tends to be structurally complex. The needle bearing arrangement disclosed by Jenkins, for example, calls for four parts: a spring, two thrust bearing races, and a needle thrust bearing.
Another type of thrust bearing is the simple thrust plate which may be dry or lubricated. The dry thrust plate, due to the absence of lubrication is limited in its usefulness to comparatively low thrust forces and low speed applications. Lubricated thrust plates have proven quite successful for use on vertical shafts where the bearing can be immersed in lubricant so that a dynamic oil film is readily maintained. However, in horizontal shaft applications, maintaining a dynamic oil film on the thrust plate for lubrication is more difficult. One approach to this problem is disclosed in U.S. Pat. No. 3,423,138 to Hardy, assigned to the General Electric Company, assignee of the present invention. Hardy discloses an improved thrust bearing and lubricating system which comprises a rotating thrust plate formed from hardened tool steel, which rotates against a stationary thrust plate of nylon, both bearings being enclosed at least partially in a housing formed from an acetal copolymer for a horizontal rotating shaft application. In the Hardy arrangement axial thrust is transmitted from the rotating thrust bearing mounted within the housing to a stationary thrust bearing within the housing and from the stationary thrust bearing to a spherical support bearing. The Hardy arrangement requires the bearing housing to retain lubricating oil around the bearings so as to maintain the protective lubricating film between the rotating thrust bearing and the stationary bearing surfaces.
Bearings formed from a porous composition such as a sintered or powdered metal composition which can be saturated with oil, or formed from a self-lubricating material such as graphite, have less stringent lubrication requirements than metal alloy bearings. However, these composition materials, while strong in compression, tend to be relatively weak in tension. Thus, the press fitting of such a bearing with the shaft to rotate with the shaft may subject the bearing to excessive tensile stress, causing the bearing to break during assembly or in operation. Use of a simple thrust bearing loosely carried on the shaft for random rotation is undesirable because such a bearing may intermittently rotate against the wrong bearing surface, causing the bearing to deteriorate or break apart. In order to use powdered metal or graphite thrust bearings, a thrust bearing assembly including means for rotating the bearing with the shaft which does not subject the bearing to excessive tension is required.
Thus, it is desirable to provide an improved thrust bearing assembly for use with a horizontally disposed rotating shaft which approaches the structural simplicity of the dry thrust plate yet which provides satisfactory lubrication for high speed application.
Accordingly, it is an object of this invention to provide an improved thrust bearing assembly for a rotatable shaft.
It is another object of this invention to provide an improved thrust bearing assembly for a rotatable shaft which is relatively quiet and relatively structurally simple.
It is another object of this invention to provide an improved thrust bearing assembly for use with a horizontally disposed shaft employing a porous powdered metal thrust bearing.
It is another object of this invention to provide an improved thrust bearing assembly for use with a horizontally disposed shaft employing a thrust bearing formed from a self-lubricating composition.
It is another object of this invention to provide an improved thrust bearing assembly for use with a horizontally disposed rotating shaft employing a thrust bearing formed from a powder metal or graphite composition which rotates with the shaft.
SUMMARY OF THE INVENTION
Briefly stated, in accordance with one embodiment of the present invention a thrust bearing assembly is provided for a horizontally disposed drive shaft, said shaft being rotatably supported by at least one non-rotating support bearing. An annular thrust bearing loosely carried on the drive shaft is disposed adjacent the non-rotating support bearing. The thrust bearing has a first thrust bearing surface facing the support bearing and a second thrust bearing surface facing away from the support bearing. A drive ring is carried on the drive shaft and has a thrust transmitting surface facing the second thrust bearing surface of the thrust bearing. Means are provided for drivingly connecting the drive ring to the drive shaft for rotational and axial motion with the shaft. Further means are provided for drivingly connecting the thrust bearing to the drive ring to drive the thrust bearing rotationally and axially in concert with the drive ring.
More specifically, in accordance with one embodiment of the present invention, an annular thrust bearing formed from a powdered metal composition is provided having first and second oppositely facing thrust bearing surfaces and a plurality of spaced apart slots formed on its outer periphery. The thrust bearing is loosely carried on the drive shaft adjacent the support bearing, with the first thrust bearing surface facing the non-rotating support bearing. Means are provided for supplying lubricant to the support bearing. This lubricant migrates along the shaft to a barrier formed by an oil seal disposed adjacent the second thrust bearing surface of the thrust bearing. A portion of this lubricant is absorbed by the porous thrust bearing and serves to lubricate the thrust bearing. An annular drive ring having a thrust transmitting surface is carried on the shaft adjacent the oil seal with the thrust transmitting surface facing the second thrust bearing surface. The drive ring includes a first set of fingers projecting from its outer periphery generally toward the thrust bearing for engaging corresponding slots on the periphery of the thrust bearing. A collet is fixedly mounted to the drive shaft adjacent the drive ring for rotation and translation with the shaft. This collet includes a set of longitudinal slots for receiving a second set of fingers which project from the inner periphery of the drive ring. Thus, rotational and translational motion of the shaft is transmitted from the shaft to the collet, to the drive ring and finally to the thrust bearing which rotates and translates with the shaft and which absorbs axial thrust exerted by the shaft toward the non-rotating support bearing.
In accordance with another embodiment of the present invention, a thrust bearing formed from a self-lubricating material such as graphite is substituted for the powdered metal thrust bearing in the above described embodiment. This embodiment is particularly useful in applications in which means for lubricating the shaft support bearing means are not provided.
BRIEF DESCRIPTION OF THE DRAWINGS
It is believed that the invention will be better understood from the following description taken in connection with the accompanying drawings in which:
FIG. 1 is a fragmentary elevational view partially cut away and partially in section to show details of an electric motor incorporating an illustrative embodiment of the bearing assembly of the present invention; and
FIG. 2 is an exploded perspective view of an illustrative embodiment of the thrust bearing assembly of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, and particularly to FIG. 1 thereof, there is shown an electric motor 10 having an outer casing 12 which supports a stator 14 therein. Stator 14 has a central opening therethrough which receives an armature 16 carried by a rotatable shaft 18. Shaft 18 also carries a collet 20 which slips over shaft 18 to support a motor cooling fan 21. Collet 20 includes an end portion 22 having a pair of substantially longitudinal slots 23 (FIG. 2). Fan 21 is secured to collet 20 by means of a sleeve 24 having an outwardly projecting flange 26 which engages fan 21 and clamps it into abutting relationship with a shoulder 28 projecting outwardly from the outer surface of collet 20. The internal diameter of sleeve 24 is slightly less than the outside diameter of end portion 22 of collet 20, so that as sleeve 24 is assembled onto portion 22, portion 22 is compressed into firm engagement with shaft 18. This arrangement is enhanced by knurling shaft 18 as shown at 25. A washer 29 made from cardboard fiber is disposed between flange 26 of sleeve 24 and fan 21.
Bearing means are provided to support one end of shaft 18 and include a substantially spherical support bearing 30 through which shaft 18 passes. A second spherical support bearing similar to support bearing 30 may be provided at the other end of shaft 18; however, for the sake of simplicity only one support bearing arrangement has been described. Support bearing 30 is carried by a plurality of tabs 32 bent out from a portion of casing 12. Moreover, support bearing 30 is maintained in supported relationship with tabs 32 by a plurality of tabs 34 bent out from a member 36 suitably secured to the inner surface of casing 12 by such means as welding or threaded screw fasteners or simply a press fit into casing 12.
A lubrication system for the above described bearing means includes a reservoir wick 38 of generally cylindrical configuration supported within a chamber 40 defined by housing 42 and the outer surface of casing 12. A combined feeder and return wick 44 having feeder wick portions 46 and return wick portion 48 is also provided. Feeder wick portions 46 are in lubricant receiving relationship with reservoir wick 38 and are adapted to convey lubricant by capillary action from reservoir wick 38 to shaft 18. Lubricant received from feeder wick portions 46 migrates along shaft 18 through support bearing 30 to the thrust bearing assembly 60 which is described below thereby providing lubrication between rotating shaft 18 and non-rotating spherical bearing 30 and to the thrust bearing.
Openings 50 are provided in member 36 and casing 12 through which return wick portions 48 pass. An annular collecting means 52 is supported by casing 12 to catch and collet any excessive lubricant which is flung from shaft 18. The purpose of return wick portions 48 is to pick up and return directly to shaft 18 lubricant collected by collecting means 52. Excessive lubricant collected by collecting means 52 which return wick portions 48 are unable to convey that quantity of lubricant out of collecting means 52 will pass through openings 50 into chamber 40 and return to reservoir wick 38 thereby avoiding any loss of lubricant from collecting means 52 into the interior of casing 12.
The foregoing lubrication system is a minor variation of the system disclosed and claimed by Thomas E. Jenkins in the aforementioned U.S. Pat. No. 3,393,025. As will become evident as this description proceeds, the exact lubrication system is not critical to the present invention and may depart considerably from that disclosed. It is important only that in embodiments of the present invention employing thrust bearings formed from powdered metal compositions, some means is provided to supply lubricant to the thrust bearing assembly 60.
In accordance with the present invention, a thrust bearing assembly 60 is provided that includes an annular thrust bearing 62 loosely carried on drive shaft 18 and having a first thrust bearing surface 64 facing surface 31 of support bearing 30, and a second thrust bearing surface 66 facing opposite the first thrust bearing surface, that is away from support bearing 30. Thrust bearing 62 is positioned on shaft 18 adjacent surface 31 of spherical support bearing 30 such that first thrust bearing surface 64 of thrust bearing 62 may engage surface 31 of support bearing 30. To insure that surface 64 rotates against surface 31, thrust bearing 62 is drivingly connected to shaft 18 for rotation with the shafts in a manner described further on.
As previously mentioned, the lubrication system causes oil to migrate along shaft 18. A portion of this oil migrates radially across surface 64 of thrust bearing 62 to form a protective lubricating film. When operating at high speed such as experienced with a dishwasher pump motor, there is a tendency for the centrifugal forces generated by the rotation of thrust bearing 62 to sling lubricating oil radially outwardly at a rate which could result in at least partial removal of the oil film on thrust bearing surface 64. In order to maintain an adequately lubricated thrust bearing surface, thrust bearing 62 is formed from a relatively porous material such as a powdered or sintered metal composition. In the illustrative embodiment thrust bearing 62 is made from a powdered iron composition including approximately three percent by weight of powdered copper. The addition of the small percentage of copper provides a degree of self lubricity. The porosity of the bearing material enables the thrust bearing 62 to absorb lubricating oil which migrates along shaft 18 to thrust bearing 62 from feeder wick 46. Since a portion of this oil is absorbed in the bearing itself, the protective film will not be entirely removed from the thrust bearing surface 64 by centrifugal forces when rotating at high speed.
To insure proper wear of thrust bearing 62 it is important that thrust bearing 62 rotates against surface 31 of spherical bearing 30. Simply loosely mounting thrust bearing 62 to shaft 18 could result in intermittent rotation of surface 66 of thrust bearing 62 against surface 65 of collet 20, which is not constructed to function as a thrust bearing surface. Wear on surface 66 resulting from rotation against surface 65 could severely shorten the life of bearing 62. Thus, thrust bearing 62 is drivingly connected to shaft 18 for rotation with the shaft. A convenient way of doing this would be to press fit the thrust bearing 62 to shaft 18. However, the powdered metal composition of thrust bearing 62, while being strong in compression, is relatively weak in tension. Thus, fitting of the bearing to the shaft would subject thrust bearing 62 to tensile stress likely to result in cracking of the bearing during assembly or during operation. Thus, it is important that thrust bearing 62 be loosely mounted to shaft 18, that is, the inside diameter of thrust bearing 62 should be slightly greater than the diameter of shaft 18 to preclude subjecting bearing 62 to tensile stress.
To facilitate rotation of bearing 62 with shaft 18, thrust bearing assembly 60 includes a drive ring 70. As shown most clearly in FIG. 2, drive ring 70 is mounted to shaft 18 adjacent thrust bearing surface 66 of thrust bearing 62. Drive ring 70 includes a thrust transmitting surface 72 which faces thrust bearing surface 66 of thrust bearing 62. Means for drivingly connecting drive ring 70 to thrust bearing 62 are provided in the form of a set of bearing engaging fingers 74 which project from the outer periphery of drive ring 70 to engage corresponding slots 68 of thrust bearing 62. Each one of fingers 74 includes a tab portion 76. When fingers 74 are properly received in slots 68 of bearing 62, tab portions 76 extend beyond bearing 62 and deflect inwardly over a portion of surface 64 of thrust bearing 62 to properly position thrust bearing 62 adjacent drive ring 70. These tab portions are particularly useful in retaining thrust bearing 62 in proper position during assembly.
Means for drivingly connecting drive ring 70 to shaft 18 are provided in the form of a set of collet engaging fingers 78. Fingers 78 project from the inner periphery of drive ring 70 toward collet 20 to engage corresponding longitudinal slots 23 formed in the end portion 22 of collet 20 facing drive ring 70. With this arrangement, rotary motion of shaft 18 is coupled from the shaft to collet 20 which is compression fit to the shaft; from collet 20 to drive ring 70 by fingers 78 engaged in slots 23; and from drive ring 70 to thrust bearing 62 through fingers 74 engaged in slots 68 of thrust bearing 62. While in the illustrative embodiment two fingers comprise each set of fingers 74 and 78, it is apparent that at least one finger per set is required and that any number more than one per set could be used. While only two fingers 74 are provided, the illustrative embodiment includes four slots 68 on the periphery of thrust bearing 62. This enhances manufacturing convenience as the additional pair of slots facilitating alignment of the bearing during assembly. A pressed fiber lubricant seal 82 is press fit to shaft 18 and disposed between thrust bearing 62 and drive ring 70. This lubricant seal serves as a barrier to the lubricating oil migrating along shaft 18.
In assembling the thrust bearing structure, fingers 78 of drive ring 70 are aligned with slots 23 in collet 20 and inserted in slots 23 such that drive ring 70 abuts collet 20. Lubricant seal 82 is then positioned to abut drive ring 70. Since lubricant seal 82 is press fit to shaft 18, it serves to hold drive ring 70 in position during assembly. Thrust bearing ring 62 is then snapped into position with surface 66 adjacent thrust transmitting surface 72 of drive ring 70 and in pressing engagement with lubricant seal 82 and fingers 74 of drive ring 70 received in slots 68 of thrust bearing 62. Thrust bearing 62 is held in this position during assembly by tabs 76. Assembled in this fashion, thrust bearing assembly 60 is in position for engagement with support bearing 30 when shaft 18 is positioned in bearing 30.
Other materials may be used to form thrust bearing 62 in keeping with the invention including materials having self-lubricating properties. One such material which has been found to be a particularly useful thrust bearing material is a carbon graphite composition or, more simply, graphite. Like the powdered metal bearings, graphite thrust bearings are relatively weak in tension and should be loosely carried on the drive shaft. A thrust bearing assembly in accordance with the present invention in which thrust bearing 62 is formed of graphite is particularly advantageous in applications in which lubricating means are not provided for lubricating the support bearings. Because of the self-lubricating properties of the graphite bearing, lubricating means are not required for the thrust bearing assembly. In such applications in which oil would not be migrating along shaft 18, oil seal 82 could be omitted from thrust bearing assembly 60.
As will be evident from the foregoing description, the invention is not limited to the particular details and construction of the examples illustrated and it is contemplated that various other modifications or applications will occur to those skilled in the art. It is therefore intended that the appended claims shall cover such modifications and applications as do not depart from the true spirit and scope of the invention.
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A thrust bearing assembly for a horizontally disposed drive shaft including an annular thrust bearing loosely carried on the drive shaft, and a drive ring drivingly connected to the drive shaft for rotational and axial motion with the shaft and operative to transmit the axial and rotational motion of the shaft to the annular thrust bearing. Preferably, the annular thrust bearing is formed of a powdered metal or carbon graphite composition. The drive ring includes fingers formed at its periphery projecting toward the thrust bearing. Slots for receiving these fingers are provided at the periphery of the annular thrust bearing. When assembled on the drive shaft, the drive ring is fixedly attached to the drive shaft adjacent the annular thrust bearing with the fingers engaged in the thrust bearing slots.
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BACKGROUND
[0001] The present application relates to semiconductor manufacturing. More particularly, the present application relates to an interposer that includes a non-silicon interposer substrate having a lattice framework and a plurality of unit cells formed therein. Each unit cell includes a plurality of conductive metal structures embedded in, and laterally surrounded by, a dielectric material.
[0002] To improve the level of integration and connectivity between semiconductor wafers, various stacking technologies have been proposed to increase the functionality by aggregating discrete components at very fine interconnect pitches onto a single planar carrier or interposer. Silicon has been the material of choice for prior interposers because there is a known supply chain, process tooling set and knowledge base for creating high density interconnects on silicon. Silicon as an interposer however has drawbacks. For example, the semiconductor behavior of silicon requires electrical isolation at all conductor interfaces. Also, silicon has a fixed thermal coefficient of expansion (TCE) of about 2.6 ppm/° C. that limits the maximum cross-sectional area of conductive filled vias in thermal cycling/reliability tests and subsequent BA operations to common laminates (with TCEs of approximately 10-12 ppm/ 20 C.), again with reliability implications.
[0003] Glass interposers have been touted as a replacement for silicon interposers due to their better electrical resistance and availability of higher TCEs. One major problem with glass is the immature processes for creating holes in the 10-30 μm range. Lasers, machining, electrochemical machining, wet etching, which have traditionally be employed to create holes into glass, all have issues with either minimum feature size or throughput in the hours/days at via densities of interest which drive very expensive and/or high tooling unit purchase. A need therefore exists for providing a simple and cost efficient method for creating glass interposers with small holes (30 μm or below). In particular this need is highlighted for large panel size starting materials to facilitate economy of scale cost reductions vs. 300 mm diameter current limitations in wafer processing tools and platforms.
SUMMARY
[0004] A lattice structure (i.e., framework) is formed in a non-silicon interposer substrate to create large cells that are multiples of through hole pitches to act as islands for dielectric fields. The term “non-silicon interposer substrate” is used throughout the present application to denote an interposer substrate that comprises a material(s) other than solely elemental silicon. Each unit cell is then filled with a dielectric material. Thereafter, holes (i.e., through holes or blind holes) are created within the dielectric material in the cells. After hole formation, a conductive structure including a conductive metal or metal alloy is formed into each of the holes. This method can enable fine pitch processing in organic-based materials, isolate the thermal coefficient of expansion (TCE) stress from metal vias to low TCE carriers and create a path to high volume, low costs components in panel form.
[0005] In one aspect of the present application, a method of forming an interposer is provided. The method includes creating a lattice structure having a plurality of unit cells in a non-silicon interposer substrate. Each unit cell of the plurality of unit cells is then filled with a dielectric material. A plurality of holes is then formed into the dielectric material of each unit cell. A conductive structure is then formed into each hole of the plurality of holes.
[0006] In another aspect of the present application, an interposer is provided. The interposer of the present application includes a lattice structure comprising a non-silicon interposer material and having a plurality of unit cells disposed therein. Each unit cell of the plurality of unit cells includes a plurality of conductive structures embedded in, and laterally surrounded by, a dielectric material.
[0007] In yet another aspect of the present application, a semiconductor structure is provided. The semiconductor structure of the present application includes an interposer disposed between a first substrate and a second substrate, wherein the interposer includes a lattice structure comprising a non-silicon interposer material and having a plurality of unit cells disposed therein. Each unit cell of the plurality of unit cells includes a plurality of conductive structures embedded in, and laterally surrounded by, a dielectric material.
BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS
[0008] FIG. 1A is a top down view of an exemplary structure including a non-silicon interposer substrate that can be employed in one embodiment of the present application.
[0009] FIG. 1B is a cross sectional view of the exemplary structure of FIG. 1A through vertical plane X-X 1 prior to processing.
[0010] FIG. 2 is a top down view of the exemplary structure of FIGS. 1A-1B after creating a lattice structure having a plurality of unit cells in the non-silicon interposer substrate.
[0011] FIG. 3A is a magnified top down view of the exemplary structure shown in FIG. 2 illustrating one of the unit cells that is surrounded by a framework structure comprising a remaining portion of the non-silicon interposer substrate.
[0012] FIG. 3B is a cross sectional view of the exemplary structure shown in FIG. 3A through vertical plane X-X 1 .
[0013] FIG. 4A is a top down view of the unit cell illustrated in FIG. 3A after providing a dielectric material in the unit cell.
[0014] FIG. 4B is a cross sectional view of the exemplary structure shown in FIG. 4A through vertical plane X-X 1 .
[0015] FIG. 5A is a top down view of the dielectric material filled unit cell illustrated in FIG. 4A after forming a plurality of holes into the dielectric material.
[0016] FIG. 5B is a cross sectional view of the exemplary structure shown in FIG. 5A through vertical plane X-X 1 .
[0017] FIG. 6A is a top down view of the unit cell illustrated in FIG. 5A after forming a conductive structure in each hole of the plurality of holes and planarization.
[0018] FIG. 6B is a cross sectional view of the exemplary structure shown in FIG. 6A through vertical plane X-X 1 .
[0019] FIG. 7 shows a lattice structure having a plurality of triangular shaped unit cells that can be created and employed in the present application.
[0020] FIG. 8 shows a lattice structure having a plurality of rectangular shaped unit cells that can be created and employed in the present application.
[0021] FIG. 9A is a top-down view illustrating the unit cell illustrated in FIG. 6A after forming another conductive structure within the unit cell.
[0022] FIG. 9B is a cross sectional view of the exemplary structure shown in FIG. 9A through vertical plane X-X 1 .
[0023] FIG. 10A is a top-down view illustrating the unit cell illustrated in FIG. 9A after forming a yet other conductive structure within the unit cell.
[0024] FIG. 10B is a cross sectional view of the exemplary structure shown in FIG. 10A through vertical plane X-X 1 .
[0025] FIG. 11 is a cross sectional view illustrating a semiconductor structure of the present application including an interposer of the present application disposed between a first substrate and a second substrate.
DESCRIPTION
[0026] The present application will now be described in greater detail by referring to the following discussion and drawings that accompany the present application. It is noted that the drawings of the present application are provided for illustrative purposes only and, as such, the drawings are not drawn to scale. It is also noted that like and corresponding elements are referred to by like reference numerals.
[0027] In the following description, numerous specific details are set forth, such as particular structures, components, materials, dimensions, processing steps and techniques, in order to provide an understanding of the various embodiments of the present application. However, it will be appreciated by one of ordinary skill in the art that the various embodiments of the present application may be practiced without these specific details. In other instances, well-known structures or processing steps have not been described in detail in order to avoid obscuring the present application.
[0028] Referring first to FIGS. 1A-1B , there are illustrated a non-silicon interposer substrate 10 that can be employed in one embodiment of the present application. The non-silicon interposer substrate 10 that can be employed in the present application includes any material other than solely elemental silicon. In one embodiment of the present application, the material(s) that can be employed as the non-silicon interposer substrate 10 may have a thermal coefficient of expansion of from 0 ppm/° C. to 15 ppm/° C., with the proviso that elemental silicon is not solely used. In another embodiment of the present application, the material(s) that can be employed as the non-silicon interposer substrate 10 may have a thermal coefficient of expansion of from 3 ppm/° C. to 10 ppm/° C. Examples of materials that can be used as the non-silicon interposer substrate 10 of the present application include, but are not limited to, glass, metals such as, for example, titanium, molybdenum, or tungsten, ceramic oxides such as alumina, or zirconia, toughed ceramic-fiber or organic-fiber composites, such as, for example, alumina toughened polyimides, or multilayered combinations thereof. In one embodiment of the present application, the non-silicon interposer substrate 10 comprises glass that has a thermal coefficient of expansion of from 3 ppm/° C. to 12 ppm/° C. In another embodiment, the non-silicon interposer substrate 10 comprises a titanium alloy that has a thermal coefficient of expansion of 7 ppm/° C. to 9 ppm/° C.
[0029] In some embodiments of the present application (and as illustrated in the drawings), the non-silicon interposer substrate 10 can be a stand-alone interposer substrate. In such an embodiment, no interposer carrier is required to be present beneath the non-silicon interposer substrate 10 during the processing steps of the present application. In other embodiments (not shown), an interposer carrier is located beneath the non-silicon interposer substrate 10 during the processing steps of the present application. In some embodiments in which an interposer carrier is employed, the interposer carrier that is employed can comprise a material that has a thermal coefficient of expansion that substantially matches the thermal coefficient of expansion of the non-silicon interposer substrate. By “substantially matches” it is meant a thermal coefficient of expansion value that is within ±5 ppm/° C. of the thermal coefficient of expansion value of the non-silicon interposer substrate 10 .
[0030] The non-silicon interposer substrate 10 that can be employed in the present application may have a thickness from 50 μm to 500 μm. Other thickness that are lesser than or greater than the aforementioned thickness range can also be used as the thickness for the non-silicon interposer substrate 10 .
[0031] The shape of the non-silicon interposer substrate 10 that is employed in the present application should be compatible with the process tooling used in the present application. As such, a panel can be used to create individual features of the present application with the intent of creating smaller units for making interposers. As an example, a large panel can be used to create multiple interposers which are subsequently cut from the panel in a form that is compatible with, for instance 300 mm wafer process tooling to finish the interposer patterning.
[0032] Referring now to FIG. 2 , there is illustrated the exemplary structure of FIGS. 1A-1B after creating a lattice structure 12 having a plurality of unit cells 14 in the non-silicon interposer substrate 10 . The lattice structure 12 which constitutes a remaining portion of the non-silicon interposer substrate 10 , serves as a frame for each unit cell 14 that is formed into the non-silicon interposer substrate 10 . The unit cells 14 are regularly shaped repeating holes that are formed into the non-silicon interposer substrate 10 . Thus, the unit cells 14 may also be referred to as a ‘sub-surface defined unit cells’. In some embodiments (not shown), the unit cells 14 can extend entirely through the non-silicon interposer substrate 10 creating through via holes. In other embodiments (and as illustrated in the drawings), the unit cells 14 are blind holes that have a bottommost surface that exposes a sub-surface of the non-silicon interposer substrate 10 . By “sub-surface” it is meant a surface of the non-silicon interposer substrate 10 that is located beneath an original topmost surface of the non-silicon interposer substrate 10 . In yet further embodiments, a first set of unit cells can extend entirely through the non-silicon interposer substrate 10 , while a second set of unit cells can extend partially through the non-silicon interposer substrate 10 .
[0033] In one embodiment of the present application, each unit cell 14 extends into the non-silicon interposer substrate 10 to a depth, as measured from the topmost surface of the non-silicon interposer substrate 10 to the exposed sub-surface of the non-silicon interposer substrate 10 , of from 50 μm to 400 μm. Other depths which are lesser than or greater than the aforementioned range can also be employed as the depth of each unit cell 14 .
[0034] In some embodiments of the present application, the lattice structure 12 may extend over the entire surface of the non-silicon interposer substrate 10 . In other embodiments of the present application, the lattice structure 12 may be present in a predetermined region(s) of the non-silicon interposer substrate 10 . For example, the lattice structure 12 may be formed within a central portion, i.e., away from edge portions, of the non-silicon interposer substrate 10 .
[0035] In one embodiment, and as illustrated in FIG. 2 , each unit cell 14 that is formed has a shape of a square. In such an embodiment, the width of the square shape unit cell 14 , as measured from one sidewall surface of a lattice structure 12 to an opposing sidewall surface of a lattice structure 12 , can be from 100 μm to 500 μm. Other shapes for the unit cells 14 are possible. For example, unit cells 14 having a triangular shape (as shown in FIG. 7 ) or unit cells 14 having a rectangular shape (as shown in FIG. 8 ) can also be formed and used in the present application. Also, and in some embodiments of the present application, it is possible to form different shaped unit cells 14 in the same non-silicon interposer substrate 10 by using block mask technology.
[0036] The lattice structure 12 including the unit cells 14 can be formed by a patterning process. Examples of patterning processes that can be used in the present application to provide the structure shown in FIG. 2 can include, but are not limited to, machining, laser ablation, etching, drilling, blasting or any combination thereof.
[0037] Referring now to FIGS. 3A-3B , there are illustrated an enlarged view (top and cross sectional, respectively) of one of the unit cells 14 that is formed as described hereinabove and as shown in FIG. 2 . As shown in FIGS. 3A-3B , the enlarged unit cell 14 is surrounded by a lattice structure 12 that constituents a remaining portion of the non-silicon interposer substrate 10 that frames the unit cell 14 . In the drawings, an embodiment of the present application is shown in which the unit cell 14 is a square shaped blind hole that is formed into an upper portion of the non-silicon interposer substrate 10 .
[0038] Referring now to FIGS. 4A-4B , there is shown the unit cell illustrated in FIGS. 3A-3B after providing a dielectric material 16 into each unit cell 14 . Although not shown, each unit cell 14 that is formed into the non-silicon interposer substrate 10 is processed to include dielectric material 16 filling the entirety of each unit cell 14 .
[0039] The dielectric material 16 that can be employed in the present application is a polymeric material (i.e., homopolymers, copolymers, etc.) which has an elastic modulus that is less than the elastic modulus of the non-silicon interposer substrate 10 . As known to those skilled in the art, the elastic modulus is a number that measures an object or substance's resistance to being deformed elastically (i.e., non-permanently) when a force is applied to it. The elastic modulus of an object is defined as the slope of its stress-strain curve in the elastic deformation region. In one embodiment of the present application, the dielectric material 16 has an elastic modulus, i.e. Young's modulus, of from 5 GPa to 15 GPa.
[0040] In one embodiment of the present application, the dielectric material 16 that can be employed in the present application has a thermal coefficient of expansion of from 5 ppm/° C. to 15 ppm/° C. In another embodiment of the present application, the dielectric material 16 that can be employed in the present application has a thermal coefficient of expansion of from 10 ppm/° C. to 12 ppm/° C.
[0041] In one embodiment of the present application, the dielectric material 16 that can be employed is a photo active (i.e., photo imageable) dielectric material; such dielectric materials can be directly patterned by exposure to photoelectric energy and development. By “photo active (or photo imageable) dielectric material” it is meant a polymeric material such as, for example, a polyimide, a polysilsequioxane, a polycarbonate, a polysiloxane, a fluorinate polyhydrocarbon, a polysilane, a polycarbosilane, a polyoxycarbosilane, a polyorganosilicates, parlene-F, or parlene-N, that is sensitive to the exposure of photoelectric energy. This sensitivity to the exposure of photoelectric energy results in changing the chemical composition of the dielectric material upon exposure by light energy. In some embodiments of the present invention, dielectric material 16 can be a photoresist material including, for example, positive-tone photoresist materials, negative-tone photoresist materials or hybrid photoresist materials.
[0042] The photo-active dielectric material that provides dielectric material 16 may be a component of a photoresist composition that may further include a photoacid generator, a base additive and a solvent. The photoacid generators, base additives and solvents are well known to those skilled in the art and, as such, details regarding those components are not fully provided.
[0043] In another embodiment of the present application, the dielectric material 16 that can be employed is a non-photo active (i.e., photo imageable) dielectric material; such dielectric materials cannot be directly patterned by exposure to photoelectric energy and development. Examples of non-photo active dielectric materials include, but are not limited to, polyepoxides, polyimides, or polybenzoxazoles.
[0044] Notwithstanding the type of polymeric material employed as dielectric material 16 , the dielectric material 16 can be formed by depositing a composition containing either a photo active dielectric material or a non-photo active photo active dielectric material filling each unit cell 14 . The deposition process that can provide the dielectric material 16 may include, for example, spin-on-coating, spray coating, dip coating, brush coating, screen printing or evaporation. After depositing the composition containing either the photo active dielectric material or the non-photo active photo active dielectric material, the deposited composition can be subjected to a post deposition baking step and/or curing step that converts the deposited composition into dielectric material 16 .
[0045] The post deposition baking step which may be employed serves to remove unwanted components, such as solvents, from the deposited composition. When performed, the post deposition baking step is typically conducted at a temperature from about 60° to about 200° C. The post deposition baking step can be performed in an inert ambient such as, for example, helium, argon, neon or mixtures thereof.
[0046] The curing step which may be employed serves to toughen or harden the deposited composition containing either the photo active dielectric material or the non-photo active photo active dielectric material by cross-linking of polymer chains. The cros slinking may be achieved by electron beams, heat or chemical additives. The curing step may be performed with or without and intermediate post-deposition step as described above. Curing may be performed by a thermal cure, an electron beam cure, an ultra-violet (UV) cure, an ion beam cure, a plasma cure, a microwave cure, an additive cure or any combination thereof. The conditions for each of the curing processes, as well as curing additives, are well known to those skilled in the art.
[0047] In some embodiments of the present application, a planarization such as, for example, chemical mechanical planarization and/or grinding, may be performed to remove any dielectric material 16 that forms on the topmost surface of the lattice structure 12 . In some embodiments, no planarization is necessary.
[0048] The dielectric material 16 that is formed into each unit cell 14 fills the entirety of each unit cell (no visible voids are present) and the dielectric material 16 has a topmost surface that is coplanar with a topmost surface of the lattice structure 12 . In some embodiments of the present application, and when the unit cell 14 extends completely through the non-silicon interposer substrate 10 , the dielectric material 16 has a bottommost surface that is coplanar with a bottommost surface of the non-silicon interposer substrate 10 .
[0049] Referring now to FIGS. 5A-5B , there are illustrated the dielectric material filled unit cell ( 14 / 16 ) illustrated in FIGS. 4A-B after forming a plurality of holes 18 into the dielectric material 16 that filled each unit cell 14 . The holes 18 that are formed into the dielectric material 16 have smaller dimensions that the unit cells 14 that were formed into the non-silicon interposer substrate 10 . The number of holes 18 that are formed into each unit cell is not limited so long as each hole 18 is surrounded by dielectric material 16 . For example, 2, 3, 4, 5, 6, etc., holes 18 can be formed. The shape of the holes 18 can also vary. For example, circular holes, square holes, rectangular holes and triangular holes can be formed; the drawings show circular holes. In some embodiments (not shown), the holes 18 can extend completely through the dielectric material 16 . In other embodiments (as shown), the holes 18 can extend partially through the dielectric material 16 . In such an embodiment, each hole 18 exposes a sub-surface of the dielectric material 16 . In yet further embodiments (also not shown), a first set of holes 18 can extend entirely through the dielectric material 16 , while a second set of holes 18 can extend partially through the dielectric material 16 .
[0050] In one embodiment of the present application, each hole 18 extends into the dielectric material 16 to a depth, as measured from the topmost surface of the dielectric material 16 to the exposed sub-surface of the dielectric material 16 , of from 50 μm to 400 μm. Other depths which are lesser than or greater than the aforementioned range can also be employed as the depth of each hole 18 . Holes 18 having multiple depths are also possible and can be formed utilizing block mask technology. These may be desired in locations where, for instance blind vias are needed for mechanical anchoring of surface features without creating an electrically conductive path to the bottom surface of the interposer.
[0051] In some embodiments of the present application and when the dielectric material 16 is made from a photo active dielectric, the holes 18 can be formed by lithography only. That is, the holes 18 can be formed by directly exposing the dielectric material 16 to irradiation and then developing the exposed dielectric material utilizing a conventional developer solution. In other embodiments of the present application, the holes 18 can be formed by drilling, wet etching, dry etching, electric discharge machining, or any combination thereof. In some embodiments, the holes can be formed utilizing a combination of lithography and etching. In such an embodiment, a separate photoresist material can be formed atop the dielectric material and thereafter hole patterns can be formed into the separate photoresist material by exposing the resist material to irradiation and resist development. Next, the hole patterns are transferred into the dielectric material 16 by etching (dry etching or wet etching) and thereafter the resist material can be stripped utilizing a conventional resist stripping process such as, for example ashing.
[0052] Referring now to FIGS. 6A-6B , there are illustrated the unit cell illustrated in FIGS. 5A-5B after forming a conductive structure 20 in each hole 18 of the plurality of holes and planarization. Notably, FIGS. 6A-6B illustrated an interposer in accordance with an embodiment of the present application which includes a lattice structure 12 comprising a non-silicon interposer material and having a plurality of unit cells 14 disposed therein, wherein each unit cell of said plurality of unit cells 14 includes a plurality of conductive structures 20 embedded in, and laterally surrounded by, a dielectric material 16 .
[0053] In one embodiment of the present application, and as shown, the entire volume of each hole 18 is occupied by a conductive structure 20 that comprises a single conductive metal or metal alloy. In another embodiment of the present application, conductive structure 20 comprises a multilayered stack of conductive metal and/ metal alloy. In yet another embodiments, a first set of conductive structures can comprise a single conductive metal or metal alloy, while a second set of conductive structures can comprise a multilayered stack of conductive metal and/ metal alloy.
[0054] In some embodiments, and as will be described herein below and as shown in FIGS. 9A-9B , each hole 18 may include a first conductive structure 20 in direct contact with sidewall surfaces of the dielectric material 16 , another dielectric material 22 in direct contact with sidewall surface of the first conductive structure 20 , and a second conductive structure 24 in direct contact with a sidewall surface of the another dielectric material 22 . In some embodiments, and as will be described herein below and as shown in FIGS. 10A-10B , each hole 18 may include a first conductive structure 20 in direct contact with sidewall surfaces of the dielectric material 16 , another dielectric material 22 in direct contact with sidewall surface of the first conductive structure 20 , a second conductive structure 24 in direct contact with a sidewall surface of the another dielectric material 22 , a further dielectric material 26 in direct contact with sidewall surface of the second conductive structure 24 , and a third conductive structure 28 in direct contact with a sidewall surface of the further dielectric material 26 . The application is not limited to only three conductive structures being formed into each hole 18 , instead, a plurality of conductive structures each embedded within, and laterally surrounded by a dielectric material can be formed into each hole 18 .
[0055] In some embodiments, an optional plating seed layer (not specifically shown) can be formed on exposed surfaces within the hole 18 prior to formation of the conductive structure 20 . The optional plating seed layer is employed to selectively promote subsequent electroplating of a pre-selected conductive metal or metal alloy. The optional plating seed layer may comprise Cu, a Cu alloy, Ir, an Ir alloy, Ru, a Ru alloy (e.g., TaRu alloy), Pt or any other suitable noble metal or noble metal alloy having a low metal-plating overpotential. Typically, Cu or a Cu alloy plating seed layer is employed, when a Cu metal is to be subsequently formed within each hole 18 . The thickness of the optional seed layer may vary depending on the material of the optional plating seed layer as well as the technique used in forming the same. Typically, the optional plating seed layer has a thickness from 2 nm to 80 nm. The optional plating seed layer can be formed by a conventional deposition process including, for example, chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), atomic layer deposition (ALD), wet chemical deposition, or physical vapor deposition (PVD).
[0056] Each conductive structure 20 , 24 , and 28 includes a conductive metal, conductive metal alloy or a conductive metal nitride. In one embodiment, the conductive structure 20 , 24 , and 28 comprises Cu, W, Al or alloys thereof such as a Cu alloy (such as AlCu). When more than one conductive structure is formed into a single hole, each conductive structure may comprise a same or a different conductive metal or metal alloy. The conductive structure 20 , 24 , and 28 can be formed by a deposition process including chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), sputtering, chemical solution deposition or plating that fills the hole 18 from the bottom upwards. In another embodiment of the present application, the conductive structure 20 , 24 , and 28 can be formed utilizing a conductive fill paste process.
[0057] Following the filling of each hole 18 with the conductive metal or metal alloy that provides the conductive structure 20 , 24 , and 28 , a planarization process such as, for example, chemical mechanical polishing (CMP) and/or grinding, can be used to remove any conductive metal or metal alloy outside the holes 18 . The planarization stops on the topmost surface of the lattice structure 12 . In some embodiments, planarization may be performed on a front side (i.e., same side of the non-silicon interposer substrate 10 containing holes 18 ) and a back side (i.e., a side opposite the surface of the non-silicon interposer substrate 10 in which each hole is formed into) providing planar front and back side surfaces as shown in FIG. 6B . In some embodiments of the present application and when each unit cell was only partially formed through the non-silicon interposer substrate 10 , portions of the non-silicon interposer substrate 10 can be removed by (planarization and/or etching) to reveal the bottommost surface of the conductive structure 20 , 24 and 28 .
[0058] Referring now to FIGS. 9A-9B , there are illustrated the unit cell illustrated in FIGS. 6A-6B after forming another, i.e., second, conductive structure 24 within the unit cell 14 in accordance with another embodiment of the present application. In this embodiment, each hole 18 may include a first conductive structure 20 in direct contact with sidewall surfaces of the dielectric material 16 , another dielectric material 22 in direct contact with sidewall surface of the first conductive structure 20 , and a second conductive structure 24 in direct contact with a sidewall surface of the another dielectric material 22 .
[0059] The structure shown in FIGS. 9A-9B is formed by first providing the structure shown in FIGS. 6A-6B without performing the planarization step; planarization is performed after all conductive structures are formed. After providing that structure, a hole is formed into each conductive structure 20 utilizing one of the hole forming processes mentioned above in forming hole 18 into dielectric material 16 . After forming the hole into each conductive structure 20 , another dielectric material is formed. The another dielectric material 22 may include one of the dielectric materials mentioned above for dielectric material 16 . In some embodiments, the another dielectric material 22 may include a same dielectric material as dielectric material 16 . In other embodiments, the another dielectric material 22 may comprise a different dielectric material than dielectric material 16 . The another dielectric material 22 may be formed utilizing one of the techniques mentioned above in forming dielectric material 16 . Following the formation of the another dielectric material 22 , a hole is formed into the another dielectric material 22 utilizing one of the techniques mentioned above in forming hole 18 . The second conductive structure 24 is then formed into this newly formed hole. The second conductive structure 24 may include a same or different conductive metal or metal alloy as conductive structure 20 . Each hole that is formed in this embodiment, has a same shape as hole 18 .
[0060] Referring now to FIGS. 10A-10B , there are illustrated the unit cell illustrated in FIGS. 9A-9B after forming a yet other, i.e., third, conductive structure 28 within the unit cell 14 in accordance with yet another embodiment of the present application. In this embodiment of the present application, each hole 18 may include a first conductive structure 20 in direct contact with sidewall surfaces of the dielectric material 16 , another dielectric material 22 in direct contact with sidewall surface of the first conductive structure 20 , a second conductive structure 24 in direct contact with a sidewall surface of the another dielectric material 22 , a further dielectric material 26 in direct contact with sidewall surface of the second conductive structure 24 , and a third conductive structure 28 in direct contact with a sidewall surface of the further dielectric material 26 .
[0061] The structure shown in FIGS. 10A-10B is formed by first providing the structure shown in FIGS. 9A-9B without performing the planarization step; planarization is performed after all conductive structures are formed. After providing that structure, a hole is formed into each second conductive structure 24 utilizing one of the hole forming processes mentioned above in forming hole 18 into dielectric material 16 . After forming the hole into each conductive structure 24 , a further dielectric material 26 is formed. The further dielectric material 26 may include one of the dielectric materials mentioned above for dielectric material 16 . The further dielectric material 26 can be the same or different from the dielectric material 16 and/or dielectric material 22 . The further dielectric material 26 may be formed utilizing one of the techniques mentioned above in forming dielectric material 16 . Following the formation of the further dielectric material 26 , a hole is formed into the further dielectric material 26 utilizing one of the techniques mentioned above in forming hole 18 . The third conductive structure 28 is then formed into this newly formed hole. The third conductive structure 18 may include a same or different conductive metal or metal alloy as conductive structure 20 and/or conductive structure 24 . Each hole that is formed in this embodiment, has a same shape as hole 18 .
[0062] Referring now to FIG. 11 , there is illustrated a semiconductor structure of the present application including an interposer 50 of the present application disposed between a first substrate 52 and a second substrate 54 . Interposer 50 includes a lattice structure 12 comprising a non-silicon interposer material and having a plurality of unit cells 14 disposed therein, wherein each unit cell of said plurality of unit cells includes a plurality of conductive structures 20 embedded in, and laterally surrounded by, a dielectric material 16 . Interposer 50 can have metal bonding pads 56 B (as are well known to those skilled in the art) located on at least one surface of the structure. In the illustrated embodiment, bonding pads 56 B are located on a bottommost surface of each unit cell (comprising element 16 and 20 ). In some embodiments of the present application, first substrate 52 may include a ceramic or organic laminate as is well known to those skilled in the art. Metal bonding pads 56 A can be located on a surface of the first substrate 52 and conventional solder balls 58 A can be located between and in direct contact with each metal bonding pad 56 A and 56 B.
[0063] An optional interconnect structure 60 may be located between the interposer 50 and the second substrate 54 . The optional interconnect structure 60 includes conductive lines/vias 62 embedded with a dielectric material 64 . The optional interconnect structure 60 can be formed utilizing techniques well know to those skilled in the art. Metal bonding pads 56 C can be located on a surface of the optional interconnect structure 60 . When the optional interconnect structure 60 is omitted, the bonding pads 56 C can be formed on a topmost surface of each unit cell (comprising elements 16 and 20 ). Second substrate 54 may include at least one silicon die with metal bonding pads 56 D located on a surface thereof. Conventional solder balls 58 B can be located between and in direct contact with each metal bonding pad 56 C and 56 D.
[0064] While the present application has been particularly shown and described with respect to various embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in forms and details may be made without departing from the spirit and scope of the present application. It is therefore intended that the present application not be limited to the exact forms and details described and illustrated, but fall within the scope of the appended claims.
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A lattice structure is formed in a non-silicon interposer substrate to create large cells that are multiples of through hole pitches to act as islands for dielectric fields. Each unit cell is then filled with a dielectric material. Thereafter, holes (i.e., through holes or blind holes) are created within the dielectric material in the cells. After hole formation, a conductive metal is formed into each of the holes providing an interposer. This method can enable fine pitch processing in organic-based materials, isolates the thermal coefficient of expansion (TCE) stress from metal vias to low TCE carriers and creates a path to high volume, low costs components in panel form.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to the disposal of animal waste, i.e., manure and is particularly concerned with a method of efficiently burning such waste material in a manner that is environmentally sound.
2. Prior Art
It has been estimated by the United States Department of Agriculture (USDA Report Misc. Pub. 1065, 1968) that nearly two billion tons of manure is generated annually in the United States. Using a density value of fifty pounds per cubic foot it has been calculated that this generated manure is enough to cover about thirty-five thousand square miles, i.e., the State of Indiana, with a one-inch layer annually. The problem is compounded by the fact that manure is produced in concentrated areas, such as feed lots, hog factories and large chicken factories, and in smaller animal processing operations, rather than being uniformly divided over the entire United States. Thus, large quantities need to be processed in local areas or both the large and small quantities need to be collected and transported to distant processing facilities.
Aside from the obvious odor problem associated with the processing of manure, other, not so obvious, problems exist. In many instances manure is mixed with water, as a result of the cleaning out of pens and stalls or by the falling rain and snow. The resulting contaminated water becomes a threat to streams, lakes and underground water supplies and ultimately to the drinking supply. Government agencies in areas of the United States having significant livestock operations are recognizing the dangers to the clean water supply and it has now become more difficult to obtain permits for large livestock operations in such areas. More recently it has become known that manure entering streams and lakes results in growth of organisms that attack and destroy fish in the streams and that even attack other animals and humans causing severe illness.
Even when used as fertilizer the animal wastes often present environmental problems that are costly and difficult to solve. For example, the manure generally contains weed seeds ingested by the animals with their feed grains. Present composting methods do not kill the weed seeds so herbicides are frequently added to the manure and when the manure is used as fertilizer the herbicide chemicals are added to the soil.
It is well recognized that when man creates environmental problems there is a cost associated with the clean-up or avoidance of the problem in the future. Trash dumped in the oceans, manufacturing process pollutants discharged into streams, rivers and lakes, exhaust emissions from automobiles and nuclear wastes are examples of environmental problems that are currently being addressed at great expense to the American taxpayer. Animal wastes represent just one more environmental problem that must be addressed to insure quality life for humans. Clearly, there is a need for methods and systems to dispose of manure, on-site, in a neat, cost effective manner.
At the present time current approaches to animal waste management are as old as the problem itself. Often it is merely spread on the ground as fertilizer or compost. Other times it is dumped into lagoons. Manure spread on the ground or placed in piles or in lagoons not only takes up large amounts of valuable ground space but creates incredible odors. The odors have resulted in the treating of the manure with chemicals to reduce or change the nature of the odors. The use of chemicals results in increased cost in the processing of the manure and the chemicals may not always be environmentally safe.
In most situations manure represents an expense and pollution liability rather than a marketable fertilizer product. In some instances, chicken litter (excreta and bedding material) can be used for cattle feed. In a limited number of areas manure is sold or given away. For most animal operations the manure is simply a nuisance. For producers unable to simply pile up manure there are, at the least, handling and transportation costs involved in moving the manure to a disposal location. Typically, for hogs, manure is produced approximately at the rate of two to three pounds per pound of weight gain. A hog will produce about six hundred pounds of manure over its four and one-half to six month life span. A producer marketing one thousand head per year would have about three hundred tons of raw manure to deal with. Since hog wastes are typically washed out of the hog pens, the total weight to be handled is probably three to four times the raw manure weight, or about one thousand tons. In addition to the costs involved in handling such large quantities of waste, it is noted that there are fewer and fewer locations where sites for the dumping of the large amount of waste can be handled. Consequently, the manure is confined to lagoons and becomes a nuisance to the producer and his neighbors.
There can be no doubt that there is a need for a method and system to dispose of manure, on-site, in a neat and cost effective manner.
SUMMARY OF THE INVENTION
Brief Description of the Invention
The present invention provides a method and system to combust manure. More particularly, using coal as fuel for the method of combustion.
Objects of the Invention
Principal objects are to provide a method and system for the burning of manure in an economical manner suitable for use by at least medium and large sized size animal operations.
Other objects are to provide for the processing of animal wastes to eliminate the health, safety and nuisance aspects while utilizing the inherent virtues of the material, i.e., its water content and its value as an energy source and as fertilizer. The heat generated by burning the animal waste, in conjunction with coal, can be readily used to create heated air, hot water or steam suitable for heating farm buildings. The animal waste can be collected and stored for such short periods of time as may be necessary to concentrate burning operations according to when the generated heat can be efficiently used for building heating. For larger animal raising operations the heat generated from the burning of the animal waste can efficiently be used in the generation of electricity to be sold or used in the farm operations.
Since most animal wastes contain a significant amount of moisture it is an object of the invention to provide a method and system for burning animal wastes containing high water content, (up to about 75%) and including slurry wastes that have been stored in lagoons or ponds.
Features of the Invention
In practicing the method of the invention animal waste is subjected to primary heat exchange to evaporate the bulk of moisture from the waste. The dried waste is then mixed with a combustible supplemental fuel and is burned. Water vapor and gasses separated during the primary heat exchange are processed to recover the water, the gasses and much of the heat used in the primary heat exchange. The recovered gasses are burned with the dried waste and supplemental fuel. Dry ash resulting from the burning of the dried waste, supplemental fuel and recovered gasses is collected for use in producing fertilizer. Exhaust from the burning of the dried waste and supplemental fuel is stripped to provide a clean exhaust suitable for discharge to atmosphere. Fly ash separated from the exhaust is mixed with dry ash in producing fertilizer. Excess heat, i.e. the heat in excess of that amount needed for drying, produced from the burning of the dried waste and supplemental fuel, is discharged to a use location, which may be a boiler, furnace, another system, or a building heating system.
The system used to perform the method of the invention includes a primary heat exchanger that will dry wastes without discharge of repugnant odors to the atmosphere. Preferably, the primary heat exchanger is heated using the heat generated by burning of the dried waste and a supplemental fuel. The primary heat exchanger may be variably constructed, depending upon the specific characteristics of the waste material and appropriate engineering considerations. However, apparatus providing for the isolation of evaporated gasses, the condensation of water vapor, and the subsequent burning of the non-condensable gasses is necessary to practice the method.
The presently preferred primary heat exchanger/dryer includes a stacked set of belt conveyors mounted within a housing. Heated air is passed through double-walled enclosure passages, around the belt conveyors transporting waste material and through horizontal passages formed in the heat exchanger/dryer. The heating of the waste material evaporates water and releases other gasses from the waste material.
A cyclone assembly, including a blower, separator, and condenser pulls primary evaporation products out of the primary heat exchanger/dryer, thereby producing a drying of the waste material. The belt conveyors transport and agitate the waste material to maximize exposure of waste material surface and to increase evaporation from the waste material. Preferably, also, the belts have cleats attached thereto to break up the waste material placed on the belts and brushes are used to prevent caking or buildup of waste material on the belts.
A first, or top endless belt, conveys waste material placed on the carrying surface thereof in a forward direction to the discharge end of the conveyor and dumps the material onto a heated skid plate. Brushes, serving as spaced cleats projecting from the carrying surface of the conveyor belt, sweep the heated skid plate during the return run of the endless belt. The brushes clean the heated skid plate and sweep the waste material dumped onto the heated skid plate, with a rolling motion, to and over an end of the heated skid plate where it drops onto the next or second belt. The waste material is transported by each endless belt and heated skid plate set, in the manner previously described, until it is thoroughly dried and is dropped onto a dried material conveyor and from that conveyor is dropped into a dry manure hopper that feeds the dried waste material onto feed conveyor moving a mixture of waste material and coal into a burner assembly, where it is burned. The number of endless belt and heated skid plate sets provided depends upon factors such as the initial water content of the raw waste material, the waste volumetric rate, and the amount of heat that is allocated for drying versus use for other purposes. Drying can be accomplished at even moderate temperatures since a cyclone separator will maintain a low dew point by extracting vapor as it evaporates, thereby carrying the vapors away before they can recondense. A low air flow velocity within the conveyor prevents dust from being carried out with the products of evaporation.
A cyclone separator draws exhaust gasses from the primary heat exchanger at below atmospheric pressure to separate water from the exhaust and returns the non-condensable gasses, including to a large extent, those odiferous gases that are water soluble and that might otherwise recombine with the separated water, to the retort of the burner assembly. Thus, the noxious odors are maintained isolated and do not escape to atmosphere.
The cyclone separator includes a heat exchanger section in which condensable gasses, primarily water vapor, will condense. In condensing, the water vapor will give up heat of vaporization, allowing a portion of the heat used for evaporation to be recovered. Water leaving the cyclone condenser is filtered in conventional fashion to remove water soluble materials, if any. Heat recovered from the cool side of the condenser heat exchanger is convected away with water or air flow and may be used in preheating functions, such as preheating of the raw waste material.
Gasses exhausted from the cyclone separator are piped to the inlet of the combustion air blower. Fresh air may also be added to the inlet of the combustion air blower. The amount of fresh air added is determined by the oxygen content of gasses coming from the cyclone separator, which oxygen content may be determined experimentally or by measurement. The fresh air and gasses from the cyclone separator are then forced into the burner assembly to supply oxygen for the complete combustion of the dried waste material and supplemental fuel. All gasses associated with the waste material and drying of the waste material are maintained separated from atmosphere throughout the process and any heat value from hydrocarbons is liberated in the burning process.
Preferably, the supplemental fuel used to burn the animal waste is crushed coal that is mixed with the dry animal waste in a stoker system having two fuel hoppers on a single screw conveyor feed line. The proportions of animal waste fuel and coal fuel are readily adjusted as necessary to produce desired combustion characteristics. Such characteristics include total heat release, gas temperature, and percentages of carbon dioxide, carbon monoxide, and oxygen. As in all combustion systems, the general goal is to maximize carbon dioxide and minimize oxygen and carbon monoxide. The additional product of combustion, water vapor, to a great extent, will be trapped in the combustion gas cyclone.
The preferred burner into which the combined fuels are transported is an under-feed coal stoker retort and tuyere assembly. The screw conveyor augers the fuel mixture upward from the bottom of a retort bowl into the burning zone. The tuyeres direct combustion air into the burning zone. As the fuel is consumed the remaining ash is pushed radially away from the burning zone onto an ash removal ring. The ash removal ring, rotating at a slow rate and having a fins on an upper surface, moves ash circumferentially until it drops into a trough containing an ash removal auger. Ash is then transported to a collection for subsequent use as fertilizer. The under feed stoker works well for coal firing rates up to 1500 lbs/hr. For larger applications other coal burning systems, such as those used for large industrial plants and in power generation plants, may be used.
While crushed coal is the preferred supplemental fuel, other fuels can be used in practicing the method of the invention. Typical suitable fuels include pulverized coal, saw dust, wood chips, chicken litter, nut shells, and other bio-mass materials with sufficient energy content to support a clean burning, high temperature combustion process. To accommodate the various fuels, a curved divider is provided within the combustion chamber to re-circulate light particles which may be blown out of the primary combustion zone. Unburned particles entrained with the combustion gasses are directed back down into a secondary combustion zone, along with combustion air injected through the divider, to maximize combustion efficiency. Combustion gasses then travel laterally along the divider in order to reach the flue. Recirculation and forcing of the gasses around edges of the diverter before exiting also aid in reducing the amount of fly ash carried from the combustion chamber with the gasses.
Combustion gasses exit the primary fire box and pass into a secondary fire box section. The secondary section provides additional surface area for heat exchange with circulation air. The secondary fire box section also serves as a trap for fly ash. Combustion gasses forced to travel down past a deflector partially covering the flue gas outlet. The rapid change in gas direction during the exhaust process helps separate particulate material from the gas stream. The fly ash so separated settles to the bottom of the secondary section and passes through an opening in the fire box floor. The opening connects into the ash removal trough to be conveyed and the fly ash is conveyed out of the furnace along with the ash separated in the fire.
Additional objects and features of the invention will become apparent from the following detailed description and drawings.
THE DRAWINGS
In the drawings:
FIG. 1 is a schematic view of the system of the invention;
FIG. 2, a top plan view of the primary heat exchanger;
FIG. 3, a vertical sectional view through the primary heat exchanger, taken on the line 3--3 of FIG. 2;
FIG. 4, a side elevation of the primary heat exchanger;
FIG. 5, a vertical section view taken on the line 5--5 of FIG. 4;
FIG. 6, an opposite side view of the primary heat exchanger;
FIG. 7, a fragmentary vertical section view, taken on the line 6--6 of FIG. 5;
FIG. 8, an end elevation view of the primary heat exchanger;
FIG. 9, a top plan view of the retort of the system of the invention;
FIG. 10, a side elevation view of the retort;
FIG. 11, a vertical section view taken on the line 11--11 of FIG. 9;
FIG. 12, an enlarged section taken on the line 12--12 of FIG. 10;
FIG. 13, an enlarged section taken on the line 13--13 of FIG. 11;
FIG. 14, an enlarged fragmentary section, taken within the line 14--14 of FIG. 12; and
FIG. 15, an enlarged fragmentary section, taken within the line 15--15 of FIG. 13.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings:
In the illustrated preferred embodiment of the invention the animal waste disposal system is shown generally at 10. The waste disposal system includes a primary heat exchanger or dryer 12 having an inlet 14 receiving manure (animal waste) from a source 16. Dried manure is discharged from the heat exchanger 12 into a dry manure hopper 18.
An auger assembly 20 carries coal from a stoker 22 through a coal hopper 24, receives dried manure from the dry manure hopper 18, and mixes and moves the coal and dried manure into a retort assembly 26 located within a furnace 28. The dried manure and coal mix is burned, with ash resulting from the burning being collected and carried to an ash receiving receptacle 32 by an ash auger drive assembly 34.
Combustion gasses released in the furnace 28 as a result of burning of the coal and dried manure are exhausted through a line 35 into a combustion gas heat exchanger 36 in the primary heat exchanger 12 and from there into a cyclone separator 38. The combustion gasses provide heat for the primary heat exchanger 12 and evaporate water from the raw manure passed through the primary heat exchanger and over the combustion gas heat exchanger 36. The raw manure is also passed over a forced air heat exchanger 40 that provides further heat in the primary heat exchanger 12 for the evaporation of moisture from the raw manure passing through the primary heat exchanger.
The evaporation products resulting from heating of the raw manure in the primary heat exchanger 12 are removed from the primary heat exchanger by a cyclone separator 42 that separates non-condensable gasses and water. The non-condensable gasses are mixed with fresh air at the inlet 44 to a blower 46 and are blown into the furnace 28 through a primary air inlet 48 or a secondary air inlet 50. Air entering the primary air inlet 48 is directed into an air chamber 52 through which air is supplied to a retort assembly 26 where the coal and dried manure are burned in the furnace 28. The air entering the secondary air inlet 50 is directed into the furnace 28 and through a baffle 56 to provide air necessary to continued burning in the upper portion of furnace 28.
A forced air blower 60 blows air into one side of a jacket 62 formed inside the outer wall of the furnace 28 where the air is heated and then is discharged at conduit 64 into the forced air heat exchanger 40 and at conduit 66 into the primary heat exchanger 12 to assist in drying the raw manure.
As best seen in FIGS. 2-8 the preferred primary heat exchanger 12 includes a housing 70 with an air jacket 72 formed around the interior of the housing and serving as a heated air passage, receiving heated air through an inlet manifold 74. Heated air traveling through the air jacket 72 passes into at least one hollow skid plate 76. The hollow skid plate 76, together with the air jacket 72 forms the combustion gas heat, and radiates heat into the housing 70 to heat and dry the raw manure and then exits the housing through a duct 78.
Combustion gases from the furnace 28 are also directed to the interior of housing 70 of the primary heat exchanger 12 through the line 35 and an inlet 82. The combustion gases are then directed into a top chamber 84 and one or more of the hollow skid plates 76, forming the combustion gas heat exchanger 36, before being discharged through a duct 86 to cyclone separator 38. The heated combustion gases heat the forced air heat exchanger, which radiates heat to the raw manure, to cause evaporation of the moisture content of the raw manure.
The raw manure entering housing 70 is deposited on a first conveyor belt 90 and is carried beneath the top chamber 84 before being discharged at the end of the conveyor run onto a first hollow skid plate 76. Cleats 92 spaced along the conveyor belt 90 push the raw manure along the skid plate 76 and off the end of the skid plate and onto a second conveyor belt 90. The second conveyor belt 90 carries the raw manure beneath the first hollow skid plate 76 and discharges onto a second hollow skid plate 76. Cleats 92, spaced along the second conveyor belt 90, push the raw manure along the second hollow skid plate 76, over the discharge end of the second hollow skid plate and onto a third conveyor belt 90. The third conveyor belt 90 carries the raw manure beneath the second hollow skid plate and discharges the manure onto a discharge conveyor belt 96.
Discharge conveyor belt 96 empties the raw manure through a chute 98 into the dry manure hopper 18.
While three conveyor belts and three hollow skid plates are shown and described more conveyor belts and hollow skid plates can be provided, as necessary to insure complete drying of the raw manure. The raw manure is heated and dried as it travels beneath top chamber 84 and over and under each hollow skid plate 76 and the moisture content of the raw manure is evaporated off, to be discharged through vent 100 that is connected to the cyclone separator 42. Cyclone separator 42 separates the evaporated gases into water that is pumped by a pump 42a through a filter 42b to a cleaned water receptacle 42c and non-combustible gases that are carried by conduit 44 to the intake of combustion air blower 46.
The cleats 92 are preferably in the form of stiff, metal brushes that will drag across the skid plates 76 to move manure along the skid plates and to clean the skid plates. The cleat-brushes produce a "rolling motion" of the manure and maximum manure surface to be exposed to the heated air introduced into the primary heat exchanger 12.
Additional brushes 102 are fixed within primary heat exchanger 12 to brush ends of conveyor belts 90 and to insure that the belts are clean before receiving manure from above. The manure cleaned from the belts 90 by brushes 102 cascades onto the conveyor belt 90 beneath the brush and eventually onto discharge conveyor belt 96 and then into the dried manure hopper 18.
The dried manure is deposited on the auger assembly 20, mixed with coal from hopper 24 and is conveyed into the furnace 28 at the bottom of the furnace and beneath the retort assembly 54. The preferred furnace 28 of the invention includes a ring of tuyeres 110 arranged in side-by-side order to surround an upper end 112 of a retort bowl 114. Air from air chamber 52 moves through the passages 115 of the tuyeres into the burning zone of the retort assembly 54. A support ring 116 rests on the wall 118 of air chamber 52, closely surrounding the ring of tuyeres 110. Rollers 120 carried by an inner ring 122 of a rotating ring 124 roll on a leg 126 of the ring 116 extending outwardly from the ring of tuyeres. Rollers 128 carried by the inner ring 122 engage and roll against a leg 130 of the support ring as the rotating ring 124 is turned around the ring of tuyeres.
A shield ring 132, having a generally T-shaped cross section has a top leg 134 extending over and resting on the ring of tuyeres 110 and the edge of leg 130 of the support ring 116. The top leg 134 also extends over a portion of the inner ring 122 of the rotating ring 124. A center leg 136 extends between the leg 130 of the support ring 116 and the inner ring 122 of the rotating ring 124. An outer rim 132 of the rotating ring 124 has a sprocket 138 formed therearound and a chain 139 engages the teeth of the sprocket 138 and the teeth of a sprocket on the output shaft of a gear box 140 that is driven by a motor 142 and chain 144. The inner ring 122 and outer rim 132 are interconnected by radiating vanes 146, with spaced apart openings 148 therebetween. As the rotating ring 124 turns around the ring of tuyeres the openings 148 each pass over a pair of ash removal slots 150 and 152.
Ash removal slots 150 and 152 are positioned above chutes 154 and 156, respectively, that discharge onto an ash auger 160, driven by the ash auger drive 34. The ash auger 160 discharges into the ash receiving receptacle 32.
The coal and manure mix delivered to the retort assembly 26 is burned as it passes through and onto the ring of tuyeres. The air necessary to such combustion is supplied through the air chamber 52 and the tuyeres 110, as has been explained. Ash resulting from such burning is pushed over the ring of tuyeres by continually fed coal and dried manure fuel. The ash is pushed over the shield ring and onto vanes 146 and into the openings 148 between vanes 146 to be rotated over the ash removal slots 150 and 152 and to fall onto the ash auger 160.
As the coal and dry manure fuel mix is burned within the ring of tuyeres, unburned particles rising with the generated heat are directed back down by the hollow, curved baffle 56 and by air from combustion air blower 46 to be burned beneath the baffle. The secondary combustion air is supplied through a secondary air manifold and into the curved baffle 56 and then through holes 166 in an inner curved wall 168 of the curved baffle.
Combustion gases from burning in the retort assembly 54 pass beneath and around the baffle 56 to enter a combustion gas chamber 170 through a passage 172, then are traveled down in the gas chamber, past a diverter 174, before exiting the retort assembly 54 through conduit 35. Combustion gases passing the diverter 174 release flue ash that falls through a chute 180 in the floor 182 of the retort assembly and onto the ash auger 160.
Although preferred embodiments of the invention have been herein described it is to be understood that the present disclosure is by way of example and that variations are possible without departing from the subject matter coming within the scope of the following claims, which subject matter is regarded as the invention.
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A method of and apparatus for the combustion of animal wastes to avoid release of objectionable odors and to obtain useful products from the animal wastes involving the drying of the animal waste in a primary heat exchange dryer, mixing the dried animal waste material with a combustible fuel and moving the mix of dried waste and combustible fuel to a burner assembly of a furnace for burning, the exhaust from the primary heat exchange dryer being collected so that gases in the exhaust are used as combustion air for the burner assembly and with exhaust from the burner assembly housing being separated into fly ash and acceptably clean exhaust.
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CLAIM OF PRIORITY
[0001] This patent application is based on and claims priority to U.S. patent application Ser. No. 60/912,364, filed Apr. 17, 2007, and is a co-pending application of Attorney Docket No. 071347U1, [filed concurrently] entitled Directional Transforms For Intra-Coding, and Attorney Docket No. 071347U3, [filed concurrently] entitled Mode Uniformity Signaling For Intra-Coding, all of which can be assigned to the assignee of the present invention, the contents of which are hereby expressly incorporated by reference herein.
TECHNICAL FIELD
[0002] The disclosure relates to digital video processing and, more particularly, to techniques for intra-frame video encoding and decoding.
BACKGROUND
[0003] In video encoding, a frame of a video sequence may be partitioned into rectangular regions or blocks. A video block may be encoded in Intra-mode (I-mode) or Inter-mode (P-mode).
[0004] FIG. 1 shows a diagram of a prior art video encoder for the I-mode. In FIG. 1 , a spatial predictor 102 forms a predicted block 103 from video block 100 using pixels from neighboring blocks in the same frame. The neighboring blocks used for prediction may be specified by a prediction mode 101 . A summer 104 computes the prediction error 106 , i.e., the difference between the image block 100 and the predicted block 103 . Transform module 108 projects the prediction error 106 onto a set of basis or transform functions. In typical implementations, the transform functions can be derived from the discrete cosine transform (DCT), Karhunen-Loeve Transform (KLT), or any other functions.
[0005] The transform module 108 outputs a set of transform coefficients 110 corresponding to the weights assigned to each of the transform functions. For example, a set of coefficients {c 0 , c 1 , c 2 , . . . , c N } may be computed, corresponding to the set of transform functions {f 0 , f 1 , f 2 , . . . , f N }. The transform coefficients 110 are subsequently quantized by quantizer 112 to produce quantized transform coefficients 114 . The quantized coefficients 114 and prediction mode 101 may be transmitted to the decoder.
[0006] FIG. 1A depicts a video decoder for the I-mode. In FIG. 1A , quantized coefficients 1000 are provided by the encoder to the decoder, and supplied to the inverse transform module 1004 . The inverse transform module 1004 reconstructs the prediction error 1003 based on the coefficients 1000 and the fixed set of transform functions, e.g., {f 0 , f 1 , f 2 , . . . , f N }. The prediction mode 1002 is supplied to the inverse spatial prediction module 1006 , which generates a predicted block 1007 based on pixel values of already decoded neighboring blocks. The predicted block 1007 is combined with the prediction error 1003 to generate the reconstructed block 1010 . The difference between the reconstructed block 1010 and the original block 100 in FIG. 1 is known as the reconstruction error.
[0007] An example of a spatial predictor 102 in FIG. 1 is herein described with reference to section 8.3.1 of ITU-T Recommendation H.264, published by ITU—Telecommunication Standardization Sector in March 2005, hereinafter referred to as H.264-2005. In H.264-2005, a coder offers 9 prediction modes for prediction of 4×4 blocks, including DC prediction (Mode 2 ) and 8 directional modes, labeled 0 through 8 , as shown in FIG. 2 . Each prediction mode specifies a set of neighboring pixels for encoding each pixel, as illustrated in FIG. 3 . In FIG. 3 , the pixels from a to p are to be encoded, and neighboring pixels A to L and X are used for predicting the pixels a to p.
[0008] To describe the spatial prediction, a nomenclature may be specified as follows. Let s denote a vector containing pixel values from neighboring blocks (e.g., values of pixels A to X in FIG. 3 form a 1×12 vector s), and s A denote the element of vector s corresponding to pixel A, etc. Let p denote a vector containing the pixel values for the block to be predicted (e.g., values of pixels a to p in FIG. 3 form a 1×16 vector p), and p a denote the element of vector p corresponding to pixel a, etc. Further let w d denote a matrix of weights to be multiplied to the vector s to obtain the vector p when a prediction mode d is specified. w d may be expressed as follows (Equation 1):
[0000]
w
d
=
[
w
a
,
A
d
w
a
,
B
d
…
w
a
,
X
d
w
b
,
A
d
⋮
⋰
w
p
,
A
d
w
p
,
X
d
]
[0000] The vector of predicted pixels p may then be expressed as follows (Equation 2):
[0000]
p
=
w
d
·
s
[
p
a
p
b
⋮
p
p
]
=
[
w
a
,
A
d
w
a
,
B
d
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w
a
,
X
d
w
b
,
A
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w
p
,
A
d
w
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X
d
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[0009] According to H.264-2005, if, for example, Mode 0 is selected, then pixels a, e, i and m are predicted by setting them equal to pixel A, and pixels b, f, j and n are predicted by setting them equal to pixel B, etc. Each set of pixels in Mode 0 corresponds to pixels lying along a single vertical direction, as shown in FIGS. 2 and 3 . The relationships of the predicted to neighboring pixels for Mode 0 may be represented as follows (Equations 3):
[0000] w 0 a,A =w 0 e,A =w 0 i,A =w 0 m,A =1;
[0000] w 0 b,B =w 0 f,B =w 0 j,B =w 0 n,B =1;
[0000] w 0 c,C =w 0 g,C =w 0 k,C =w 0 o,C =1;
[0000] w 0 d,D =w 0 h,D =w 0 l,D =w 0 p,B =1;
[0010] and all other w 0 =0.
[0011] On the other hand, if Mode 1 is selected, pixels a, b, c and d are predicted by setting them equal to pixel I, and pixels e, f, g and h are predicted by setting them equal to pixel J, etc. In this case, each set of pixels corresponds to pixels lying along a single horizontal direction, also as shown in FIGS. 2 and 3 . The relationships for Mode 1 may be represented as follows (Equations 4):
[0000] w 1 a,I =w 1 b,I =w 1 c,I =w 1 d,I =1;
[0000] w 1 e,J =w 1 f,J =w 1 g,J =w 1 h,J =1;
[0000] w 1 i,K =w 1 j,K =w 1 k,K =w 1 l,K =1;
[0000] w 1 m,L =w 1 n,L =w 1 o,L =w 1 p,L =1;
[0012] and all other w 1 =0.
[0013] Note that the modes given in H.264-2005 all specify setting the pixels along a single direction (e.g., the vertical direction in Mode 0 , and the horizontal direction in Mode 1 ) equal to each other, and to a single neighboring pixel. While this is straightforward to implement and specify, in some cases it may be advantageous to set pixels along a single direction to values that are different from each other, and/or a combination of more than one neighboring pixel.
SUMMARY
[0014] An aspect of the present disclosure provides a method for encoding an image block, the image block comprising a set of pixel values, the method comprising selecting a prediction mode for predicting pixels in the image block based on neighboring pixels, the prediction mode specifying the predicted value of at least one pixel in the image block as a combination of at least two neighboring pixels.
[0015] Another aspect of the present disclosure provides a method for predicting an image block, the image block comprising a set of pixel values, the method comprising receiving a prediction mode for predicting pixels in the image block based on neighboring pixels; and generating a predicted block based on the neighboring pixels and the prediction mode, the generating comprising combining at least two neighboring pixels to predict at least one pixel in the image block.
[0016] Yet another aspect of the present disclosure provides an apparatus for encoding an image block, the image block comprising a set of pixel values, the apparatus comprising a spatial predictor for selecting a prediction mode for predicting pixels in the image block based on neighboring pixels, the prediction mode specifying the predicted value of at least one pixel in the image block as a combination of at least two neighboring pixels.
[0017] Yet another aspect of the present disclosure provides an apparatus for predicting an image block, the image block comprising a set of pixel values, the apparatus comprising an inverse spatial prediction block, the block receiving a prediction mode for predicting pixels in the image block based on neighboring pixels, the block combining at least two neighboring pixels to predict at least one pixel in the image block.
[0018] Yet another aspect of the present disclosure provides a computer program product for predicting an image block, the image block comprising a set of pixel values, the product comprising computer-readable medium comprising code for causing a computer to receive a prediction mode for predicting pixels in the image block based on neighboring pixels; and code for causing a computer to generate a predicted block based on the neighboring pixels and the prediction mode, the code causing the computer to combine at least two neighboring pixels to predict at least one pixel in the image block.
BRIEF DESCRIPTION OF DRAWINGS
[0019] FIG. 1 shows a diagram of a prior art video encoder for the I-mode.
[0020] FIG. 1A depicts a video decoder for the I-mode.
[0021] FIG. 2 shows prediction modes described in H.264-2005.
[0022] FIG. 3 illustrates pixel prediction using prediction modes.
[0023] FIGS. 4A-4D show a pictorial representation of the elements of matrix w 0 for the pixels a, e, i, and m.
DETAILED DESCRIPTION
[0024] Disclosed herein are techniques to set pixels along a single direction to values that are different from each other, and/or a combination of more than one neighboring pixel.
[0025] In one aspect, for a prediction mode, each pixel along a single direction may be specified independently of other pixels along the same direction. For example, for Mode 0 , the elements of the matrix w 0 may be modified as follows (Equations 5):
[0000] w 0 a,A =1;
[0000] w 0 e,A =0.9;
[0000] w 0 i,A =0.8;
[0000] w 0 m,A =0.7;
[0000] and other elements of w 0 preserved as according to Equations 1. As shown in Equations 5, each of the pixels a, e, i, and m is predicted based on the neighboring pixel A, but each pixel has a different weight as compared to the other pixels.
[0026] Note that the specification of the matrix w d is provided to both encoder and decoder, so that the decoder has a priori knowledge of w d for each prediction mode. Thus, no additional signaling between encoder and decoder is required beyond that shown in the embodiments of FIGS. 1 and 1A . Note also that Equations 5 are provided only to illustrate specifying each pixel independently of others, and are not meant to limit the disclosure to any specific values shown for the matrix w 0 .
[0027] The decoder, receiving the prediction mode d, and having a priori knowledge of the matrix w d may decode the encoded block as shown in FIG. 1A .
[0028] In conjunction with or alternatively to the aspect described above, another aspect provides that, for a prediction mode, each pixel along a single direction may be specified as a combination of two or more neighboring pixels. For example, for Mode 0 , the elements of the matrix w 0 for Mode 0 may be modified as follows (Equations 6):
[0000] w 0 a,A =0.5;
[0000] w 0 a,B =0.5;
[0000] while other elements of w 0 are unchanged from Equations 3. The predicted value (p a ) corresponding to the pixel a in FIG. 3 may then be expressed as follows (Equation 7):
[0000]
p
a
=
[
w
a
,
A
0
w
a
,
B
0
…
w
a
,
X
0
]
[
s
A
s
B
⋮
s
X
]
=
0.5
s
A
+
0.5
s
B
[0000] Note the values for w 0 in Equations 6 are provided only as an illustration, and should not be interpreted to limit the disclosure to the values provided.
[0029] In an embodiment, the above two aspects can be combined. For example, weights can be assigned such that pixels to be encoded along the same direction are weighted progressively less in favor of one or more originating encoding pixels, as the distance from the originating pixel increases. Similarly, progressively more weight may be assigned to the encoding pixels surrounding the pixels to be encoded as the distance from the originating pixel increases.
[0030] To illustrate this embodiment, FIGS. 4A-4D show a pictorial representation of the elements of matrix w 0 for the pixels a, e, i, and m. FIG. 4A shows a pictorial representation of the elements of matrix w 0 for pixel a (p a ). In FIG. 4A , neighboring pixel A is considered the originating encoding pixel. As shown, for pixel a, only weight w 0 a,A is assigned a non-zero weight of 1. FIG. 4B shows weight assignments for pixel e. As shown, pixel e is assigned a different set of weights from pixel a, i.e., w 0 a,A =0.9, and w 0 a,f =0.1. FIG. 4C shows weight assignments for pixel i. For pixel i, w 0 a,A =0.8, w 0 a,J =0.05, w 0 a,K =0.1, and w 0 a,L =0.05. FIG. 4D shows weight assignments for pixel m. For pixel m, w 0 a,A =0.5, w 0 a,K =0.2, and w 0 a,L =0.3.
[0031] Note that the weight assignments in FIGS. 4A-4D are intended to serve only as illustrations, and are not meant to limit the scope of the present disclosure to any particular values of weights shown.
[0032] In an embodiment, the sum of all weights used to encode a single pixel can be set to 1, as shown in FIGS. 4A-4D .
[0033] Based on the teachings described herein, it should be apparent that an aspect disclosed herein may be implemented independently of any other aspects and that two or more of these aspects may be combined in various ways. The techniques described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in hardware, the techniques may be realized using digital hardware, analog hardware or a combination thereof. If implemented in software, the techniques may be realized at least in part by a computer-program product that includes a computer readable medium on which one or more instructions or code is stored.
[0034] By way of example, and not limitation, such computer-readable media can comprise RAM, such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), ROM, electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), FLASH memory, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other tangible medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer.
[0035] The instructions or code associated with a computer-readable medium of the computer program product may be executed by a computer, e.g., by one or more processors, such as one or more digital signal processors (DSPs), general purpose microprocessors, ASICs, FPGAs, or other equivalent integrated or discrete logic circuitry.
[0036] A number of aspects and examples have been described. However, various modifications to these examples are possible, and the principles presented herein may be applied to other aspects as well. These and other aspects are within the scope of the following claims.
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Techniques for improving the accuracy of prediction in intra-frame coding. A prediction mode can specify a pixel along a direction independently of other pixels along the same direction. In an embodiment, an encoder selects a prediction mode to best represent the image block. In an alternative embodiment, a decoder reconstructs each pixel in the image block by weighting neighboring pixels according to a weight matrix specified by the prediction mode.
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FIELD OF THE INVENTION
[0001] This invention relates to heat activated thermoplastic adhesive films used primarily in tape form as a lap splice to bond textiles together. In particular, the tape is a laminate construction comprised of three or more layers with a central supporting layer having a higher melting point than the surrounding layers.
BACKGROUND OF THE INVENTION
[0002] Textiles are used in web or sheet form to cover and protect a large variety of items. In the construction of such items as awnings, convertible tops for motor vehicles, garments, geotextiles and tents, it is common to sew or stitch sections together to form larger sheets.
[0003] Tarpaulins are used in marine, military and recreation (circuses, picnics and the like) applications and in transportation (truck, train, freight covers) many of which are formed by splicing together roll goods of textiles resulting in many seams due to the large areas involved.
[0004] A disadvantage of stitched or sewn seams is that they can leak and over time the stitches can deteriorate and fail.
[0005] Further, many of these textiles are handled as roll goods and it is important to be able to splice textiles together on the fly in an automated process at high machine operating speeds without the bond severing or breaking.
[0006] A number of patents deal with the splicing of sheet materials together.
[0007] U.S. Pat. No. 4,699,824 to Pufahl discloses a pressure sensitive adhesive tape of particular utility as a flying slice; composed of a frangible substrate formed of a ply of a cured thermoset resinous aldehyde condensate (or fibrous cellulose web impregnated with said condensate) and an elastomeric pressure sensitive adhesive (PSA) on at least one side of the substrate.
[0008] U.S. Pat. No. 4,410,575 to Hiraoka and Co. recites a lap welding method for textile fabrics wherein a piece of synthetic bonding tape is interposed between the superposed two end portions and a high frequency wave treatment is applied (or heat) and pressure to melt the tape. Claim 1 specifically recites “wherein at least one side edge portion of said interposed bonding tape extends outwardly over a corresponding edge of one of said end portions . . . and remains unmelted.”
[0009] This is to prevent edge peeling. Said bonding tape (claim 6) consists essentially of at least one member selected from the group of polyvinyl chlorides, polyurethanes, polyesters, polyamides, vinyl chloride—vinyl acetate copolymers, and ethylene-vinyl acetate copolymers.”
[0010] U.S. Pat. No. 4,094,721 to Dynamit Nobel recites the use of a linear saturated crystalline polyester (of specific moieties) useful in securing textile substance to a substrate. Claim 17 recites “In a process for securing one substrate to another by disposing between said substrates a heat fusible material and maintaining the substrates in sufficient juxtaposition until said material has fused and bond one of said substrates to the other, the improvement which comprises employing a heat fusible material of the polyester in claim 1.
[0011] U.S. Pat. No. 4,093,492 to Plate Bonn Gesellschaft mit Beschrankter Haftung claims “a process for heat-sealing together surfaces of materials comprising applying to at least one of the surfaces to be sealed a composition comprising a copolyamide having a melting range below about 110° C.” and a specific chemical structure.
[0012] U.S. Pat. No. 4,310,373 to Firma Carl Freudenburg relates to a method of heat sealing the opposing surfaces of planar textile materials which comprises applying a heat-seal adhesive to at least one of the opposing surfaces, and then pressing them together under heat and pressure. The heat-seal adhesive employed is a low melting polyurethane of specific molecular weight. The adhesive is in the form of a spun-bonded fabric.
[0013] U.S. Pat. No. 5,368,923 to Textile Coated International recites the use of a bonding interlayer which includes a non-fluoro plastic carrier element coated with a fluoroplastic which melts under heat and pressure.
[0014] U.S. Pat. No. 6,060,408 to Creative Football Concepts discloses a double sided adhesive element for securing an article of clothing comprising a flexible support member having a first side coated with an adhesive and a second side coated with an adhesive, said support member comprising cloth, and said adhesive an acrylic adhesive.
[0015] U.S. Pat. No. 4,740,416 to The Kendall Company discloses novel adhesive tapes consisting of a layer comprising glass or resin microspheres disposed in a polymer matrix, a cloth screen or reinforcing fabric and a layer of adhesive, preferably a PSA. These products are useful as duct tapes.
[0016] U.S. Pat. No. 4,091,150 to 3M discloses a splicing tape for abutted ends formed of an adhesively coated support film which comprises a biaxially oriented, heat set, co-extruded laminate formed from a layer of crystalline polyester material and a layer of less crystalline polyester material, with the thermosetting adhesive coating the surface of the latter layer. The support film is preferably PEN, PCDT or PET.
[0017] However, each of these references is directed to a specific bonding process or chemical polymer type.
SUMMARY OF THE INVENTION
[0018] It is the object of the present invention to overcome the limitations of prior splicing tapes by providing a laminate construction in the form of a heat activated tape that is capable of being automatically processed on high speed equipment to form splices for textile materials. Further, the tape can be chemically configured to be adhesively compatible with a variety of textile substrate materials and physically configured to have a thickness and construction that is compatible with the thickness and weave of the textile substrates being bonded. It is a further object of this invention to provide a laminate construction in the form of a heat activated tape that can be processed using a variety of sources of heat and pressure. In particular this tape offers significant improvement over stitched or sewn seams by providing faster splicing speeds, improved splice bond strength, and the elimination of seam leaks and stitch rot with deterioration as stitches and holes would no longer be present.
[0019] According to the invention, these objects are achieved by providing heat activated thermoplastic adhesives having a laminate construction of three or more layers, which can be applied by such processing methods as hot air welding, hot wedge welding, radio frequency welding and the like. This construction is comprised of an adhesive layer, a supporting layer and a second adhesive layer, wherein the supporting layer comprises a fabric, mesh or film having a higher melting point than the surrounding adhesive layers. The adhesive layers can be made from a variety of polymers and coating processes and can be in any combination that is compatible with the substrates being bonded. Additionally, layers of pressure sensitive adhesive can be applied to either or both of the aforementioned heat activated thermoplastic adhesive layers to provide a tacky surface to assist in the bonding process.
[0020] In broad embodiment, therefore, the present invention comprises a laminate construction-for splicing textile materials together comprising a first layer of heat activated adhesive having a melting point T 1 , a second layer of heat activated adhesive having a melting point T 2 , and a support layer located between said first layer and said second layer, said support layer having a melting point T 3 higher than T 1 and T 2 .
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] These and other objects, features and advantages of the invention will become apparent upon consideration of the description of this invention and the appended drawings in which:
[0022] [0022]FIG. 1 shows a cross-sectional view of the laminate construction of the invention; and
[0023] [0023]FIG. 2 shows an alternate laminate construction having pressure sensitive adhesive layers applied to aid in processing.
[0024] The above and other objects, features and advantages of the present invention will be apparent in the following detailed description thereof when read in conjunction with the appended drawings wherein the same reference characters denote the same or similar paths throughout the several views.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] For elements common to the various embodiments of the invention, the numerical reference character between the embodiments is held constant, but distinguished by the addition of an alphanumeric character to the existing numerical reference character. In other words, for example, an element referenced at 10 in the first embodiment is correspondingly referenced at 11 A, 10 B, and so forth in subsequent embodiments. Thus, where an embodiment description uses a reference character to refer to an element, the reference character applies equally, as distinguished by alpha-numeric character, to the other embodiments where the element is common.
[0026] Referring now to the figures, FIG. 1 shows a typical three layer laminate construction of the present invention comprising a top adhesive layer 10 and bottom adhesive layer 12 and a supporting material 13 of fabric, mesh, film or the like which has a higher melting point than either adhesive layer 10 or 12 . The adhesive layers can be slot die, blow extruded or solution coated films made from polyamide, polyester, polyethylene, polyurethane or any combination of these polymers which are compatible with the textiles to be bonded. The adhesive layer thickness used is determined by the thickness and weave of the textiles to be bonded but typically the adhesive layers will preferably be in the range of 0.001″-0.015″ in thickness.
[0027] The supporting layer 13 is the central layer between the adhesive layers 10 , 12 and comprises a fabric (woven or non-woven), mesh or film which has a higher melting point characteristic such that it does not melt as fast as the original adhesive layers as the central layer between the two adhesive layers.
[0028] The laminate is designed in this manner to prevent it from severing or breaking (and promote faster running speeds) in the automated feeding processes used to deliver the adhesive in tape form to the point where it will be activated (between the two textiles).
[0029] The tapes of this invention an be applied by a number of processes known to those skilled in the art such as:
[0030] Hot air welding—the tape (preferably 0.25″-2″ in width) is fed from a roll between two layers of textiles. The textiles are aligned with the tape along the outer edges to splice the textiles edge to edge—with an overlap area equal to the width of the tape. The hot air welding process activates the adhesive with jets of hot air directed onto the surfaces of the tape (one jet is directed on the top surface of the tape and the other is directed on the bottom surface) and uses pinch rollers to press together the textiles and activated adhesive to create an intimate bond.
[0031] Hot wedge welding—a tape (preferably 0.25″-2″ width) is fed from a roll between two layers of textiles. The textiles are aligned with the tape along the outer edges to splice the textiles edge to edge—with an overlap area equal to the width of the tape. The hot wedge welding process utilizes a heated metallic tool (wedge) over which the tape is fed. The other side of the wedge is in contact with the textile which serves to heat both surfaces and accelerate the bonding process. As in the hot air welding process, the hot wedge welding process also uses pinch rollers to apply pressure to the bonded area as the adhesive is activated.
[0032] RF (radio frequency) welding—a tape (preferably 0.25″-2″ width) is fed from a roll between two layers of textiles. The textiles are aligned with the tape along the outer edges to splice the textiles edge to edge with an overlap area equal to the width of the tape. The RF welding process activates the adhesive using radio frequency energy. The tool used activates the adhesive as it applies pressure. It can either be a continuous process with an active tool or a reciprocating process in a press where the bond is created when the RF cycle is engaged after the seams and tape are aligned in the tool.
[0033] [0033]FIG. 2 shows an alternate laminate construction having pressure sensitive adhesive (PSA) layers 11 , 14 applied to the top 11 A and/or bottom 13 A adhesive layers to provide a tacky surface to the tape to assist in locating the tape in the area of the splice. Since the top 10 A and bottom 13 A adhesive layers are dry at room temperature, pre-applying a PSA prior to final bonding of the textile substrates together allows the tape to maintain its position through the high speed automated feeding process of the tape into the splice.
[0034] Thus, it can be seen that the invention provides a new and improved laminate construction of heat activated adhesives which can function as a bonding adhesive using a variety of heat and pressure processes to replace, stitched seams in the construction of tarpaulins, awnings, and the like where splicing of textile materials is involved.
[0035] The description and drawings illustratively set forth our presently preferred invention embodiments. We intend the description and drawings to describe these embodiments and not to limit the scope of the invention. Those skilled in the art will appreciate that still other modifications and variations of the present invention are possible in light of the above teaching while remaining within the scope of the following claims. Therefore, within the scope of the claims, one may practice the invention otherwise than as the description and drawings specifically show and describe.
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A laminate construction for splicing textile materials together comprising a first layer of heat activated adhesive having a melting point T 1 and a second layer of heat activated material having a melting point T 2 . A support layer is located between the first layer and the second layer, and the support layer has a melting point T 3 which is higher than T 1 and T 2
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BACKGROUND
[0001] Coiled tubing rigs rely on coiled tubing injectors to inject coiled tubing into a well. Generally, the bottom of the coiled tubing injector is mounted directly to a stripper assembly through which the coiled tubing moves prior to entering a well stack and the well. Attempts have been made to provide greater flexibility in the ability to connect a given coiled tubing injector to a variety of well stacks by using telescoping risers between the stripper assembly and the well stack. However, the use of telescoping risers incurs a high cost and a high level of active maintenance. Additionally, the telescoping risers are required to maintain wellbore pressure.
SUMMARY
[0002] In general, the present invention provides a system and method for improving the ability to inject coiled tubing at a variety of wells. The system and method utilize a telescopic, anti-buckling guide through which coiled tubing is moved before entering the stripper assembly and ultimately entering the well. The telescopic, anti-buckling guide is designed to support the coiled tubing to prevent buckling under operating loads. Additionally, the telescopic, anti-buckling guide facilitates connection to a variety of well control stacks of different heights without requiring vertical movement of the coiled tubing injector and without the need for pressure containment members in the guide.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Certain embodiments of the invention will hereafter be described with reference to the accompanying drawings, wherein like reference numerals denote like elements, and:
[0004] FIG. 1 is a schematic front view of a telescopic, anti-buckling guide system, according to an embodiment of the present invention;
[0005] FIG. 2 is a side view of the telescopic, anti-buckling guide, according to an embodiment of the present invention;
[0006] FIG. 3 is an orthogonal view of a lower guide member of the telescopic, anti-buckling guide illustrated in FIG. 2 , according to an embodiment of the present invention;
[0007] FIG. 4 is an orthogonal view of an upper guide member of the telescopic, anti-buckling guide illustrated in FIG. 2 , according to an embodiment of the present invention; and
[0008] FIG. 5 is an exploded view of the telescopic, anti-buckling guide system, according to an embodiment of the present invention.
DETAILED DESCRIPTION
[0009] In the following description, numerous details are set forth to provide an understanding of the present invention. However, it will be understood by those of ordinary skill in the art that the present invention may be practiced without these details and that numerous variations or modifications from the described embodiments may be possible.
[0010] The present invention relates to a system and methodology for facilitating the injection of coiled tubing into a well. A telescopic, anti-buckling guide enables deployment of a coiled tubing injector head onto a well control stack without requiring vertical movement of the injector head. The telescopic character of the guide also enables adjustment of the distance between the coiled tubing injector and the well control stack which allows the injector head to be used with well control stacks of different heights without requiring vertical movement of the injector head. The guide also supports the coiled tubing and prevents buckling of the coiled tubing between the coiled tubing injector and a stripper assembly positioned at the top of a well control stack.
[0011] Generally, the telescopic, anti-buckling guide provides a conduit for directing the coiled tubing from the injector head without requiring pressure seals. All pressure containing equipment can be located within the well control stack which reduces the cost and simplifies the structure of the telescopic, anti-buckling guide. For example, the cost of manufacturing the guide is reduced, and there are no maintenance requirements that would otherwise be associated with pressure seals. By avoiding the need to contain pressure, the telescopic, anti-buckling guide also avoids the need for locks that would otherwise be necessary to prevent unwanted expansion of the guide when exposed to internal well pressure.
[0012] One embodiment of a guide system 10 is illustrated in FIG. 1 as positioned at a well site 12 . In this example, guide system 10 comprises a telescopic, anti-buckling guide 14 connected between a coiled tubing injector 16 and a well stack, such as well control stack 18 . In the embodiment illustrated, telescopic anti-buckling guide 14 is directly connected to a stripper assembly 20 positioned generally at the top of well control stack 18 .
[0013] Well control stack 18 is positioned on a surface 22 above a well 24 having a wellbore 26 . Well control stack 18 comprises pressure control equipment 28 to control the internal well pressure within wellbore 26 and to prevent unwanted passage of well fluids through well control stack 18 . Pressure control equipment 28 may comprise one or more members that can form the desired pressure seals able to hold back the internal well pressure. For example, blowout preventers or other pressure seals can be used. In the embodiment illustrated, all pressure control and all pressure control equipment is located below telescopic, anti-buckling guide 14 in, for example, well control stack 18 . Accordingly, telescopic, anti-buckling guide 14 can be manufactured without pressure seals.
[0014] Coiled tubing injector 16 is designed to deliver coiled tubing 30 (shown in dashed lines) into well 24 . Pressure control equipment 28 can be used to form a seal with the coiled tubing 30 to prevent passage of internal well pressure. Furthermore, telescopic, anti-buckling guide 14 is sized to support coiled tubing 30 and to prevent buckling of the coiled tubing between the coiled tubing injector 16 and the well control stack 18 , e.g. between coiled tubing injector 16 and stripper assembly 20 . Guide 14 supports coiled tubing 30 against buckling when exposed to operating loads.
[0015] The telescopic capability enables guide 14 to be compressed or extended as necessary to enable the connection of stripper assembly 20 to a variety of well control stacks 18 of different heights without requiring vertical movement of coiled tubing injector 16 . When a coiled tubing injection operation is completed or the coiled tubing injector 16 is to be moved to another well stack, the stripper assembly 20 can simply be uncoupled from well control stack 18 . Once uncoupled, the stripper assembly 20 is lifted upwardly to compress telescopic, anti-buckling guide 14 so as to clear well control stack 18 without requiring vertical movement of coiled tubing injector 16 . The coiled tubing injector 16 , guide 14 and a stripper assembly 20 can then be moved to the next desired location.
[0016] One embodiment of telescopic, anti-buckling guide 14 is illustrated in FIG. 2 . In this embodiment, guide 14 comprises an upper guide 32 and a lower guide 34 that are telescopically engaged. In the example illustrated, upper guide 32 and lower guide 34 are interlocking, sliding cylindrical tubes that slide over one another. For example, lower guide 34 may be sized to slidably receive upper guide 32 therein. However, upper guide 32 can be sized to slidably receive lower guide 34 within its interior; or upper guide 32 and lower guide 34 may be provided with other interlocking, telescopic configurations.
[0017] By way of example, lower guide 34 may comprise a body portion 36 that is tubular in shape and has a hollow interior 38 sized to slidably receive upper guide 32 . As also illustrated in FIG. 3 , lower guide 34 may further comprise a mount 40 that is configured for connection with stripper assembly 20 . Mount 40 may be in the form of a mounting flange 42 that is attached to stripper assembly 20 by a suitable fastener mechanism, such as a threaded engagement, a plurality of threaded fasteners, one or more weldments, or a combination of mechanisms. Lower guide 34 further comprises an expanded housing 44 that may be located generally between mount 40 and body portion 36 . Expanded portion 44 comprises a window 46 positioned to provide access to a portion of stripper assembly 20 when stripper assembly 20 is engaged with telescopic, anti-buckling guide 14 . For example, window 46 can be used to provide access to stripper assembly retaining pins 48 (see FIG. 2 ). Additionally, lower guide 34 may comprise other features, such as a side connector 50 that can be used to facilitate movement and positioning of lower guide 34 and/or telescopic, anti-buckling guide 14 .
[0018] By way of further example, upper guide 32 may comprise a body portion 52 , as further illustrated in FIG. 4 . In this embodiment, body portion 52 is generally tubular and includes a hollow interior 54 . Body portion 52 is sized so that its outside diameter fits within the inside diameter defined by hollow interior 38 of lower guide body portion 36 . Furthermore, hollow interior 54 is sized to support a coiled tubing 30 against buckling when coiled tubing 30 is moved through telescopic, anti-buckling guide 14 . Upper guide 32 may further comprise a connector 56 that is configured for connection with coiled tubing injector 16 . Connector 56 may comprise a flange 58 designed for connection to coiled tubing injector 16 by a suitable fastener mechanism, such as a threaded fastener end, a plurality of threaded fasteners, one or more weldments, or a combination of mechanisms.
[0019] As illustrated in the expanded view of FIG. 5 , body portion 52 of upper guide 32 is slidably engaged with body portion 36 of lower guide 34 to form the main body of telescopic, anti-buckling guide 14 . A retention ring or other mechanism 60 can be used to, for example, prevent inadvertent separation of upper guide 32 from lower guide 34 once combined. Additionally, a variety of guides, e.g. inserts, 62 can be used to selectively size the hollow interior of guide 14 according to the size of coiled tubing 30 that is to be delivered through telescopic, anti-buckling guide 14 and into well 24 . A connection end 64 of stripper assembly 20 is inserted into the interior of the expanded portion 44 and exposed via window 46 . In many operations, stripper assembly 20 is retained in engagement with telescopic, anti-buckling guide 14 during movement from one well stack to another.
[0020] Depending on a variety of factors, including well stack size and style, environment, coiled tubing injector type, and well operation performed, the size and configuration of telescopic anti-buckling guide 14 may vary. The telescopic characteristics can be achieved with a variety of upper and lower guides that are coupled together for selective expansion and contraction. The internal diameters of cylindrical style guides can be adjusted to accommodate different coiled tubing sizes, and a variety of inserts or other mechanisms can be used to provide the desired guidance of coiled tubing into well control stack 18 and well 24 . Furthermore, the telescopic, anti-buckling guide 14 can be designed with ends configured for engagement with a variety of coiled tubing injectors and stripper assemblies.
[0021] Accordingly, although only a few embodiments of the present invention have been described in detail above, those of ordinary skill in the art will readily appreciate that many modifications are possible without materially departing from the teachings of this invention. Accordingly, such modifications are intended to be included within the scope of this invention as defined in the claims.
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A technique improves the ability to inject coiled tubing at a variety of wells. A telescopic, anti-buckling guide is designed to support the coiled tubing to prevent buckling under operating loads. The telescopic, anti-buckling guide also facilitates connection to a variety of well control stacks of different heights without requiring vertical movement of the coiled tubing injector and without the need for pressure containment members in the guide.
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BACKGROUND OF THE INVENTION
[0001] The invention relates to a process for aerating suspensions, particularly to flotate them, for example in deinking of pulp suspensions, with one or more stages and/or cells, where each stage/cell has its own separate liquid loop. In addition, the invention relates to a device for implementing the process.
[0002] A process of this type is known, for example, from EP 1 124 001 A2, where the individual flotation stages can also be designed according to U.S. Pat. No. 4,255,262, EP 0 243 690, DE 31 20 202, or U.S. Pat. No. 6,208,549, for example.
[0003] Processes of this type are used to remove impurities and printing ink particles from pulp suspensions, particularly those produced in waste paper treatment. By applying this type of process, non-specific removal of mineral components (e.g., fillers containing ash, etc.) is achieved because their chemical surface properties (particularly loading) are such that they react differently from the ink particles, which are relatively easy to render hydrophobic, in the pulp suspension. In addition, the specific weight of the mineral components is approximately two to three times higher than that of the ink particles. In the processes known, however, some disadvantages occur in selective flotation. If, for example, attempts are made to target the removal of fillers by making certain changes to the process, this always results in a drop in the efficiency of printing ink removal, which leads to a need for additional changes in gas loading, adjustments to the raw material fluctuations, and changes in throughput. Furthermore, if the overflow quantity is increased in order to raise the removal rate of mineral substances, the fibre loss rises in equal proportion to this, which leads to greater expense for disposal and raw materials required.
SUMMARY OF THE INVENTION
[0004] The aim of the invention is to reduce or avoid the above disadvantages, while maintaining the same flow path and aeration gas loading.
[0005] In the preferred context, the invention may broadly be considered as a process for deinking a pulp suspension by passing the suspension through a series of flotation cells to remove impurities, wherein the improvement comprises diverting at least a portion of the suspension from a cell, washing impurities from the diverted suspension, and returning the washed suspension to a cell.
[0006] The invention is thus characterised by a washing process being interposed into the flotation process, where the washing process can be interposed in the liquid loop of one cell, for example a primary or secondary cell, or between the cell stages, i.e., between primary and secondary cells. As a result, it is possible to remove mineral content, particularly ash content, selectively and simply.
[0007] In more specific terms, the invention can considered as a process for removing particulate impurities from a feed flow suspension of recoverable solids by passing the feed as an impure fluid flow through a flotation stage, collecting and discharging the flotated impurities through an overflow line, and discharging the purified suspension through an accepts line, wherein each flotation cell has an internal flow loop for processing a portion of the impure fluid flow before discharge from the stage or cell, and wherein the improvement comprises removing some of the impurities by washing at least a portion of the impure fluid flow.
[0008] If the solids suspension is diluted to a consistency of some 0.6-1.4%, particularly 0.8-1.3%, before entering the secondary cells, the flotation efficiency can be increased.
[0009] If, according to an advantageous further development of the invention, one washing process each is interposed at least into the loop of two cells, ash removal can be further improved substantially.
[0010] If the accept flows from at least two washing processes are fed together here to a further washing process (so-called double washing), a further increase can be achieved in the amount of ash removed at reduced fibre loss.
[0011] It has proved particularly favourable if the, at least two, washing processes are interposed into the loop of primary cells.
[0012] It is advantageous if the accept from the entire process has an ash content of less than approximately 20%, preferably below 15%, at an ingoing filler content of approximately 23% and more. As a result, the accept can be returned to the process again with low fibre loss.
[0013] Furthermore, the invention relates to a device for aerating suspensions, particularly to flotate them, for example in deinking of pulp suspensions, with one or more stages and/or cells, where each stage/cell has its own separate liquid loop. According to the invention, this device is characterised by a washer being interposed in the series of flotation cells, where the washer can be interposed into the liquid loop of a cell, for example a primary or secondary cell and/or between the cell stages, i.e., between primary and secondary cells.
[0014] Viewed from another perspective, the invention can be considered as an aeration plant having a suspension feed inlet, means for removing particulate impurities from a feed suspension of recoverable solids by passing the feed as an impure fluid flow through at least one impurities flotation stage, means for collecting and discharging the flotated impurities through an overflow line, and means for discharging the purified suspension through an accepts line, wherein the improvement further comprises a washer for removing some of the impurities in at least a portion of the impure fluid flow.
[0015] The invention is preferably in the form of an aeration plant having a suspension feed inlet, means for removing particulate impurities from a feed flow suspension of recoverable solids by passing the feed as an impure fluid flow through an impurities flotation stage having a plurality of flotation cells, means for collecting and discharging the flotated impurities through an overflow line, and means for discharging the purified suspension through an accepts line, wherein at least one cell has an internal flow loop for mixing air from an air line with a portion of the impure fluid flow in a liquid line, for aeration injection into the same cell, and wherein the improvement further comprises a washer situated in the internal flow loop, for removing some of the impurities in at least a portion of the impure fluid flow in said loop.
[0016] If, according to the invention, at least one washer each is interposed into the loop of two cells, removal of ash filler can be further improved substantially.
[0017] If the accept flows from the at least two washers are fed together to a further washer, a further increase can be obtained in ash removal.
[0018] A further reduction in the fibre losses while diminishing the volume flows from the flotation washing system can be achieved by post-washing of the reject flows collected.
[0019] Furthermore, it has provided advantageous to interpose at least two washers into the primary cells loop.
[0020] A favourable configuration results if the washer or washers is/are designed as rotation washers with vertical rotor axis or, alternatively, as roll washers.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] The invention will now be described with reference to the preferred embodiments using the examples in the drawings, where
[0022] [0022]FIG. 1 shows a state-of-the art flotation plant;
[0023] [0023]FIG. 2 shows a first variant of the invention;
[0024] [0024]FIG. 3 shows a second variant of the invention;
[0025] [0025]FIG. 4 shows a particularly favourable third variant of the invention;
[0026] [0026]FIG. 5 shows a first variant of a washer for implementing the invention;
[0027] [0027]FIG. 6 shows a second variant of a washer for implementing the invention;
[0028] [0028]FIG. 7 represents a mass balance according to the state of the art; and
[0029] [0029]FIG. 8 represents a mass balance according to the variant of the invention shown in FIG. 3.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0030] [0030]FIG. 1 is a schematic diagram of a flotation plant according to the state of the art having a primary stage with four primary cells, P 1 , P 2 , P 3 and P 4 , and a secondary stage with two secondary cells, S 1 and S 2 . The flow of pulp suspension Z is brought into the first primary cell P 1 at a suitable point. The aeration bubbles are generated inside this cell via internal loop 1 , which is disconnected from the feed, by the injector 2 drawing in suspension from the bottom of the cell in a liquid line and air from an air line Land mixing it for injection into the suspension in the same cell. The entire flotation plant is largely filled with suspension, on the surface O of which a foam forms which contains as much as possible of the mineral substances and ink particles to be removed by flotation. The accept flow cleaned in primary cell P 1 to remove ink and impurities is transferred to the second primary cell P 2 through an opening 5 located at the base of the dividing wall 10 . There and in all other primary cells the suspension is treated in the same way, with bubble generating injectors which are operated by internal cell loops, and is discharged at the end of the plant as accept G. The foam collected from all primary cells P 1 to P 4 can drain off down a foam channel 3 into a tank 4 . The overflow from this intermediate tank 4 , from which the foam has largely been removed in the meantime, is fed to the secondary cell S 2 . Gas loading takes place here again round the internal cell loop 6 . The accept from the secondary cell S 2 to the secondary cell S 1 is transferred through the opening 7 located at the base. After gas loading by loop 8 , the foam from the secondary cells can be removed as overflow F. The accept from the secondary cell S 1 enters the first primary cell P 1 through the opening 9 in the dividing wall 11 located at the base.
[0031] As a basic principle, the washing stage according to the invention can be interposed at several points. It can be inserted in the internal loop of a primary cell or a secondary cell, or between the primary and secondary stages. FIG. 2 shows the washing stage interposed in a primary stage and a secondary stage. The washer 12 is installed at one of the primary cells (P 1 , P 2 , P 3 , P 4 ), depending on the desired process control and cleanness requirements. As an alternative or in addition, one washer 12 ′can be interposed in the loop of a secondary cell (S 1 , S 2 ). As an example, FIG. 2 shows a washer 12 at P 2 and a washer 12 ′ at S 2 . The washer 12 , 12 ′ is installed downstream of an injector pump 13 . Compared with the state of the art, in the invention the injector pump 13 provides a higher pressure output at the same throughput.
[0032] A part flow of the liquid from which the ash is to be removed is drawn off near the base of the cell P 2 , S 2 before the cell content drains into the next cell and enters the same cell after the ash has been removed in the washer 12 , 12 ′ and the pulp consistency set by means of the diffuser 14 , 14 . There is also the possibility of including washing stages between several cell chambers. The fillers (mainly ash) and fines removed in the washer 12 , 12 ′ are brought to a sewage treatment plant. The degree of ash removal can be set with the usual machine parameters. By setting the injector flow rate independently of production, according to the state of the art as shown in FIG. 1, it is also possible to coordinate the degree of ash removal in the market pulp.
[0033] If, according to the invention, forward feed of the entire production flow is requested or if a washing stage is to be installed in an existing DIP (de-inked pulp) plant, the ash can also be removed from the entire flow between the cells. In order to retain the flotation efficiency, the loop must be opened and the pulp consistency further diluted, preferably to approximately 0.8 to 1.3%.
[0034] In FIG. 3, the feed 15 to the secondary cell is treated in a washer 16 , acting as ash removal device, such that the hydraulic load in the secondary cells is reduced due to removal of ash and fines. The fundamental aspect here, however, is targeted removal of ash. The mass balances of this configuration are shown in FIG. 7 for state of the art and in FIG. 8 for the present invention. The variant of FIG. 3 shows the most effective form of partial flow washing because the foam is already enriched considerably with mineral substances during the flotation process.
[0035] In the ash removal process the accept is thickened. In order to ensure that the pulp consistency is not too high in secondary flotation, the pulp suspension is normally diluted to approximately 0.6 to 1.4%. This process is needed in all ash removal procedures within the flotation stage.
[0036] A further potential means of removing the ash is shown in FIG. 4. Here, the ash is removed in two partial flows. In order to further reduce the fibre losses, the ash removal units 17 , 17 ′ are cascaded. The accept, now depleted of filler and coming from the next washer 18 , is brought to the flotation foam tank 4 and undergoes further flotation together with the overflow foam from the primary cells to the secondary cells. The reject, which contains a high concentration of fillers and fines, is disposed of in a DAF (Dissolved Air Flotation) unit or a sludge press.
[0037] [0037]FIG. 5 shows a potential variant of an ash removal device in the form of a rotation washer 20 . The suspension is fed to the top of washer 20 through the feed branch 21 . A stationary fitting 22 deflects the suspension flow downward with favourable flow characteristics to the inner part of the cylindrical screen basket 23 . In this area there is a rotor 24 , which has an upstream parabolic shape and downstream foils 25 extending radially outward toward basket 23 . The accept passing through the screen 23 is collected in an accept area 26 and discharged through the accept outlet 27 . The rotor 24 is driven by drive 28 . This type of unit has low energy consumption, achieved by the favourable flow path, particularly the parabolic rotor. A high level of ash removal can be obtained by optimising screens and foil designs.
[0038] [0038]FIG. 6 shows an alternative configuration of a washer as a roll washer 30. The suspension is fed through a so-called headbox 31 , through which the suspension is injected between the roll 32 and a screen 33 . The screen 33 is driven by a drive roll 34 and the filtrate, which is the accept, exits through the filtrate discharge 35 .
[0039] [0039]FIG. 7 shows the pulp flows in a state-of-the-art flotation plant 40 . The flotation plant shown here comprises primary cells 41 and secondary cells 42 . The suspension feed 43 is fed to the primary cells 41 , from where the overflow 44 is brought to the secondary cells 42 . The accept 45 is carried away from the primary cells 41 , while the overflow 46 with the concentrated solids is taken from the secondary cells 42 . At some points in the system more shower water 47 is added. The values for the individual pulp flows are shown in the following Table 1.
TABLE 1 Volume flow, Solids rel. ash content in Flow No. total [l/min] content [%] solids [%] Feed 43 15000 1.2 25.0 Return flow 44 3200 1.07 66.0 Flow rate/ 45 15500 1.07 21.2 accept Discharge/ 46 550 2.55 70.0 overflow Shower water 47 1050 — —
[0040] [0040]FIG. 8 shows the pulp flows from a flotation plant 40 according to FIG. 3, with primary cells 41 and secondary cells 42 . The suspension feed 43 is fed to the primary cells 41 , from where the overflow 44 , is brought to the ash removal device, specifically to the washer 48 . The “accept” 49 from the washer 48 is reduced to a consistency of less than 1% by adding dilution water 52 and fed to the secondary cells 42 at 53 . The flow with a high filler load 50 coming from the washer is mixed with the overflow 46 from the secondary cells 42 and discharged from the system as total overflow 51 . The values of the individual pulp flows can be found in the following Table 2. For present purposes, the flow in 43 , 41 , 44 , 53 , and 42 can be defined as an impure fluid flow, and thus the invention includes locating the washing device 48 and associated wash return 49 not only in the secondary return line 53 , but at any location in the impure fluid flow, e.g., 41 , 44 , 53 , and/or 42 .
TABLE 2 Volume flow Solid content rel. ash content in Flow No. total [l/min] [%] solids [%] Feed P1 43 15000 1.2 25.0 Foam 44 2550 1.11 64.8 discharge from primary cells Flow 45 14480 1.11 17.2 rate/accept Overflow from 46 30 2.3 72.7 secondary cells Showerwater 47 1100 — — Return flow 49 240 3.9 14.7 after washer 48 Discharge 50 2300 0.8 89.5 after washer 48 Total overflow 51 2330 0.8 88.9 Dilution water 52 720 — — Return flow to 53 960 0.97 14.7 secondary cells
[0041] In a comparison of Tables 1 and 2 it becomes clear that the process according to the invention provides accept with a higher solids content and a lower relative ash content, with the same solids and ash input. Thus, almost twice as much ash is discharged compared to the state-of-the-art process.
[0042] If the plant is also equipped with further washers for part flows, e.g. according to FIG. 2 or 4 , even better ash removal rates can be obtained.
[0043] Removal of a large percentage of the filler from the production flow has a further positive effect, namely additional removal of small ink particles which are difficult to remove by flotation. As a result, the brightness or whiteness is also increased.
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The invention relates to a process for aerating suspensions, particularly to flotate them, for example in deinking of pulp suspensions, with one or more stages and/or cells P 1 , P 2 , P 3 , P 4 , S 1 , S 2 , where each stage/cell P 1 , P 2 , P 3 , P 4 , S 1 , S 2 has its own separate liquid loop 6 . In order to improve ash removal, the invention provides for a washing process 12, 12′, 16, 18 being interposed. In addition, the invention relates to a device for implementing the process.
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FIELD OF THE INVENTION
This invention relates to a mobile broiler apparatus and, more particularly, relates to a mobile broiler mounted on a trailer frame having road engaging wheels and a hitch for connection to a vehicle and, in addition, a table construction forming an integral part therewith and which is movable between a retracted position for storage and an extended position of use thereof.
BACKGROUND OF THE INVENTION
Outdoor cooking apparatus of various kinds are available in the market place. However, broiler units for use in catering large outdoor cookouts is not available and the subject matter of my invention discussed below relates to just such an apparatus for the aforesaid use. While the mobile broiler apparatus described hereinbelow arose out of a need for a unit for rental purposes or for use in providing catering services for large cookouts, it is to be recognized that other uses could be possible and the following disclosure is not to be limiting.
Accordingly, it is an object of this invention to provide a mobile broiler apparatus mounted on a trailer frame and having road engaging wheels and a hitch for attachment to a vehicle.
It is a further object of this invention to provide a mobile broiler apparatus, as aforesaid, wherein a table member is an integral part of the mobile broiler apparatus and is movable between a retracted and an extended position, the table when in the extended position providing a serving table upon which food can be placed and distributed.
It is a further object of this invention to provide a mobile broiler apparatus, as aforesaid, which will comply with Environmental Protection Agency regulations and other health agency regulations.
It is a further object of this invention to provide a mobile broiler apparatus, as aforesaid, which is easy to clean and maintain in proper operating condition.
SUMMARY OF THE INVENTION
In general, the objects and purposes of the invention are met by providing a mobile broiler apparatus having a trailer frame means including road engaging wheel means and hitch means for connection to a vehicle. An open top chamber having sidewalls and a bottom wall is mounted on the trailer frame means. A support is provided in the chamber adjacent the upper edge for holding and supporting food supporting means mounted thereon and in spaced relation from the bottom of the chamber. Controllable heat generating means are positioned in the spacing between the food supporting means and the bottom wall for cooking food supported on the food supporting means. First guide means are mounted on at least one of the sidewalls adjacent the upper edge of the chamber and extend along the entire side of the open top chamber. Table means and second guide means thereon cooperably engage the first guide means for facilitating a relative movement of the table means with respect to the chamber means between a first position closing the open top of the chamber and a second position located along a side of the chamber. The table means when in the first position overlaps the food supporting means to permit transportation to distant locations and when in the second position functioning as a support surface to facilitate a distribution of food placed thereon.
BRIEF DESCRIPTION OF THE DRAWINGS
Further objects and purposes of this invention will be apparent to persons acquainted with apparatus of this general type upon reading the following specification and inspecting the accompanying drawings, in which:
FIG. 1 is a top view of the mobile broiler apparatus embodying my invention;
FIG. 2 is a bottom view thereof;
FIG. 3 is a right side view thereof;
FIG. 4 is a front view thereof;
FIG. 5 is a rear view thereof;
FIG. 6 is a sectional view taken along the line VI--VI in FIG. 1;
FIG. 7 is a sectional view taken along the line VII--VII of FIG. 1; and
FIG. 8 is a sectional view taken along the line VIII--VIII of FIG. 1.
DETAILED DESCRIPTION
A mobile broiler apparatus 10 embodying my invention is illustrated in the drawings and includes a trailer frame 11 having an axle secured through conventional leafspring construction 13 and U-bolts 14 to the trailer frame 11. Wheels 16 are rotatably secured to the opposite ends of the axle 12 in the usual manner. A trailer tongue 17 is connected to the trailer frame 11 and has a hitch construction 18 on the free end thereof. A tubular bracket 19 is secured to the trailer tongue 17 and the axis of the opening therethrough extends vertically. A post 20 is received in the tubular bracket 19 and is maintained in a fixed position by a lock pin 20A received in aligned holes provided in both the tubular bracket 19 and the post 20 to fixedly position the post 20 relative to the trailer tongue 17. The purpose of the post 20 and its relative positioning with respect to the trailer tongue 17 is to permit an adjustment of the trailer frame 11 so that it is generally horizontal when in the parked position and when the hitch construction 18 is disconnected from a vehicle.
An open top box 21 having four sidewalls 22, 23, 24 and 25 and a bottom wall 26 is mounted on the trailer frame 11 and secured thereto by any conventional type of construction, as by welding. The open top box 21 defines a chamber 27. A plurality of brackets 31 are secured to the outer periphery of three sidewalls 23, 24 and 25 and extend outwardly therefrom. The brackets 31 each have a horizontal flange 32 thereon. The upper edges of the sidewalls 23 and 25 each have a curled over rim construction 33. The upper edge of the sidewalls 22 and 24 have a similar type of curled over rim construction 34. The rim constructions 33 and 34 are elevated above the horizontal flanges 32. A wooden support surface 36 is mounted on and secured to the horizontal flanges 32 and the thickness of the support surface 36 is generally equal to the spacing between the horizontal flange and the upper surface of the rim constructions 33 and 34. The support surface 36, while being made of wood in this particular embodiment, can be made of any type of material so long as the material is generally resistant to the transmission of heat.
A table device 37 includes an elongated sheet of material 38, such as stainless steel, having curled edges 39 along the opposite longitudinal edges thereof. The curled edges 39 are adapted to partially encircle and cooperate with the curled rim constructions 33 adjacent the upper edges of the sidewalls 23 and 25 of the chamber 27. In other words, the curled rim constructions 33 define a track for receiving the curled edges 39 on the table 37. The table 37 has a length generally equal to the length of the opening into the chamber 27 and can be slid along the rim constructions 33 to positions closing the entire top of the chamber 27 and positions extended out over the top of the trailer tongue 17 as illustrated in FIGS. 1 to 3. A flange 41 is secured to the right end of the table 37 (FIGS. 1 to 3) and has a tab part 42 extending into the path of the curled over rim 34 of the sidewall 22 to limit movement, here movement in a frontward direction out over the top of the trailer hitch, and an inadvertent removal of the table during the aforesaid movement. The usual sockets are provided on the underside of the table 37 at the end thereof remote from the flange 41 for receiving table legs 43 and 44. These table legs 43 and 44 are removable so that when the table 37 is slid to a position closing the top of the chamber 27, the legs 43 and 44 may be stored inside the chamber 27, for example, during transportation to distant locations. The sheet metal 38 of the table 37 is rigidified by, in this particular embodiment, a pair of longitudinally extending ribs 46 provided in the sheet metal 38.
A plurality of brackets, here L-shaped brackets 47 are secured to the underside of the support surface 36 located at the rear of the mobile broiler apparatus 10. A generally L-shaped protective shield 48 is secured to the rear sidewall 24 and one leg of the bracket 47. The purpose of the protective shield will become apparent hereinbelow. A pair of taillights 49 are secured to the underside of the support surfaces 36 and can, if desired, be secured directly to the sidewalls of the box 21.
Referring now to FIGS. 6 to 8, a pair of elongated shelf members 51 are secured to the internal surfaces of the sidewalls 23 and 25. The shelf members 51 are spaced below the rim constructions 33. A stepped support member 52 is secured to the internal position of each of the sidewalls 23 and 25 and extend between the upper surface of the shelf members 51 and terminate at a position just below the rim constructions 33. The upper portion of the support member 52 defines a first step 53. An intermediate step 54 is provided in the support member 52 and the lower end of the support member 52 is spaced from the innermost edge of the shelf member 51 to define a third step 55.
A flat planar cooking surface, oftentimes referred to as a griddle 56, is mounted on and supported by the uppermost step 53. The griddle 56 has a raised edge 57 therearound with an opening 58 provided along one edge thereof to facilitate the removal of collected cooking remnants therethrough. The griddle 56 has a size which occupies approximately one half of the open top portion into the chamber 27. The remainder of the open top part of the chamber 27 is occupied by a grid 59 which is mounted on and supported by the step 54. The grid 59 can be of any conventional type of construction such as is shown in the drawings and occupies the remainder of the open top part of the chamber 27. A basketlike member 64 is mounted on and supported by the step 55. The basket 61 has a perforated type construction to facilitate the passage of heat therethrough toward the grid 59. A plurality of stones or devices for collecting grease and the like from food that is placed on the grid are provided in the basket 62 in a conventional manner.
A pair of brackets, here L-shaped brackets 63 and 64 are connected to and extend between the sidewalls 23 and 25 of the box 21. A hole 65 is provided in the sidewall 67 at an elevation approximately equal to the elevation of the bracket 63. A burner unit 66 is received in the hole 65 and is supported in the sidewall 22 and on the upper surface of the bracket 63. The burner unit 66 is of a conventional type capable of distributing a combustible gas to holes provided therein to supply a uniform heat to the undersurface of the griddle 56. An inlet connector 67 is connected to the burner unit 66 on the portion of the burner unit which is exposed to the outside of the chamber 27.
Similarly, a hole 68 is provided in the sidewall 24 at an elevation equalling the elevation of the bracket 64. A burner unit 69 is mounted so that it is received in the hole 68 and is supported by the sidewall 24 at one end and by the bracket 64 at the other end. The burner unit 69 is of a conventional construction having a plurality of holes therein permitting the passage of combustible gas therethrough to provide a uniform heat to the undersurface of the basket 61 and grid 59. An inlet connector 70 is provided on the portion of the burner unit which is exposed to the outside of the chamber 27.
A spacing 71 is provided between the innermost ends of the burner units 66 and 69. A pair of L-shaped brackets 72 and 73 are connected to and extend between the sidewalls 23 and 25 of the box 21. The brackets 72 and 73 are spaced immediately below the brackets 63 and 64. A drawer 74 which is approximately equal in width to the spacing 71 is slidably mounted on the brackets 72 and 73 and is adapted to pass out through an opening 76 provided in the sidewall 25. A front panel 77 is secured to the front side of the drawer 74 and is exposed to the exterior of the chamber 27. A handle 78 is secured to the front panel 77 in a conventional manner. The drawer 74 is located below the opening 58 in the griddle 56 so that the cooking remnants pushed through the opening 58 will be collected in the drawer 74.
A support bracket 81 is secured to the box 21 adjacent the front end thereof as best illustrated in FIG. 3. The support bracket 81 is adapted to support a pair of tanks capable of holding a quantity of propane gas or other gaseous combustible type material. A conduit 83 extends from the usual outlets from the tanks 82 to a distributor pipe 84 mounted in openings provided in the bracket 31 secured to the sidewall 23 of the box 21. The conduit 83 is connected to the distributor pipe 84 intermediate the ends thereof so that valves 86 and 87 connected in circuit with the distributor pipe 84 at the ends thereof can provide control of the gas flow to the two burner units 66 and 69. In this particular embodiment, piping is provided between the left end of the conduit 84 and valve 87 to the inlet connector 67 to the burner unit 66. As a result, the control valve 87 controls the quantity of gas supplied to the burner unit 66. Similarly, a piping is connected between the right end of the distributor pipe 84 in FIG. 3 and control valve 86 to the inlet connector 70 to the burner unit 69. As a result, the control valve 86 controls the quantity of gas supplied to the burner unit 69.
The taillights 49 are supplied with electrical power from the vehicle through a wire 89 mounted inside a conduit 88 secured to the underside of the trailer frame 11 as illustrated in FIG. 2. The free end of the wire 89 has a plug 91 mounted thereon.
OPERATION
Although the operation and use of the device embodying the invention has been indicated somewhat above, said operation will be described in detail hereinbelow for convenience.
When a person or organization decides to have an outdoor party with many invited guests, that person or organization usually does not have sufficient time to construct the apparatus for cooking the food for the many invited guests. Such person may be the manager of a restaurant, motel, hotel, golf course or the like and it is desired to rent the necessary equipment or utilize the services of a professional organization capable of providing and cooking the food for the many invited guests. In the past, and when it is desired to cook the food over an open fire, crude cooking devices, such as cement blocks with grids thereon or oil drums which have been cut in half and have grids thereon have heretofore been utilized to provide a fire chamber for holding the fire. However, this type of construction makes it necessary for the particular person that is having the party to clean the apparatus following the event. The disclosure contained herein relates to a device which makes it possible to rent such equipment or for a professional organization to cater an event and bring the cooking equipment to the site of the festivity. The mobile broiler apparatus may be connected to a conventional trailer hitch on a vehicle and drawn to the site of the festivity. Thereafter, the trailer hitch may be disconnected from the vehicle and the post 20 adjusted to the proper elevation so that the cooking surface provided by either a pair of griddles 56 or a pair of grids 59 or by the structure illustrated in FIG. 1, for example, is level. Thereafter, the table device 37 may be extended by sliding same along the rim constructions 33 to the extended position illustrated in FIGS. 1 to 3. The legs 43 and 44 may then be inserted in the appropriate sockets so that the outer free end of the table device 37 will be properly supported. An adjustment of the post 20 relative to the trailer tongue 17 will facilitate a maintaining of the table 37 and cooking surfaces close to a horizontal alignment.
Thereafter, the valves (not shown) on the tanks 82 may be turned on and the valves 86 and 87 may be selectively turned on so that the gas coming from the openings in the respective burner units 66 and 69 may be ignited to provide heat for cooking purposes. The control valves 86 and 87 may thereafter be selectively controlled to provide the proper amount of heat to the undersurface of the cooking surfaces.
If the griddle 56 is utilized, any cooking remnants contained thereon may be pushed through the opening 58 provided therein and collected in the drawer 74.
Following a cooking of the food, the cooked food may be placed on the table 37 and the people desiring such food can line up along the side edges of the table 37 so that the food placed thereon can be distributed to the people. The support surfaces 36 located along the side edges of the chamber 27 provide a form of protection to prevent the inadvertent contact of the body with the hot sidewalls of the chamber 37. Similarly, such support surfaces 37 can also be utilized for the purposes of placement of food thereon for distribution to the people.
At the completion of the cooking operation, the mobile broiler apparatus can be quickly disassembled by sliding the table 37 over the open top of the chamber 37, after the gas supply to the burner units 66 and 69 have been shut off. The legs 43 and 44 can be properly stowed and the mobile broiler apparatus transported back to the original location for clean-up purposes. As a result, the particular person and/or organization which had the festivity does not need to be concerned with the clean-up procedure concerning the cooking apparatus.
Although a particular preferred embodiment of the invention has been disclosed in detail for illustrative purposes, it will be recognized that variations or modifications of the disclosed apparatus, including the rearrangement of parts, lie within the scope of the present invention.
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A mobile broiler apparatus including a trailer frame having road engaging wheels thereon and a hitch for connection to a vehicle. The trailer frame has an open top chamber having sidewalls and a bottom wall mounted thereon with support brackets being secured to the inside walls of the chamber adjacent the upper edges thereof. Food supporting devices are mounted on the support brackets in spaced relation from the bottom wall and vertically spaced above a controllable heat generator positioned in the spacing between the food supporting devices and the bottom wall for cooking food supported on the food supporting device. A guide mechanism is provided on the sidewalls of the chamber which extend in a direction parallel to the longitudinal axis of the trailer frame. A table device having guide mechanisms thereon is cooperably engaged with the guide mechanism on the chamber for facilitating a relative movement of the table with respect to the chamber between a first position closing the open top of the chamber and a second position located along side the chamber, preferably out over the top of the hitch for the trailer frame so as to prevent inadvertent contact therewith by persons standing around the mobile broiler apparatus.
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60/622,833, filed Oct. 28, 2004, the entire contents of which is incorporated herein by reference.
BACKGROUND
[0002] 1. Technical Field
[0003] The present disclosure relates generally to air treatment devices, and more particularly, to air treatment devices for use with refuse or non-refuse containers and receptacles.
[0004] 2. Background of the Related Art
[0005] Containers and receptacles of various shapes, sizes and configurations are utilized in kitchens, garages, bathrooms, nurseries, workrooms, professional offices, hotels, resorts, health clubs, health care facilities, theaters, amusement parks, garbage collection areas and the like. Odors and germs gather in these containers and receptacles depending upon the waste or matter contained therein. Additionally, odors emanating from such containers oftentimes attract insects or rodents.
[0006] Devices disseminating various kinds of air treating materials, such as air freshening, disinfectant and insecticidal materials have been developed to solve these problems. Common solid air treatment devices include, but are not limited to, (i) disks, domes, dishes or other dispensers which hold air treating blocks or cakes; (ii) disks, domes, dishes or other dispensers which hold gel material which, when it dries or shrinks, releases a vaporized air-treating composition into the air, (iii) disks, domes, dishes or other dispensers which hold paperboard coated with a vaporizable composition, (iv) disks, domes, dishes or other dispensers which hold scented disks, and (v) disks, domes, dishes, bags or other dispensers which hold liquid solutions, and the like. Common deodorizing, disinfecting or insecticidal solid air treating materials include, but are not limited to, blocks or cakes, gels, paperboard, scented disks, bags or other means for holding liquid solutions, and the like.
[0007] Most solid air treatment devices have inferior construction in that they only hold one particular size, shape or configuration of a solid air treating material and do not permit users to purchase a variety of solid air treating material to be used in that same air treatment device. Also, most solid air treatment devices, after a period of time, result in dried or shrunken material that remains within the air treatment device. Most dried or shrunken solid air treating material shakes, rattles or rolls when the solid air treatment device is moved or affixed to a surface which moves or is moved. Moreover, most solid air treatment devices do not affix very well or are too heavy to be mounted on the underside of a refuse or non-refuse container's or receptacle's lid or cover. The currently available devices do not provide for sufficient air-flow to maximize the effectiveness of the solid air treating material. Additionally, current solid air treatment devices generally fail to notify the user as to when the effectiveness of a solid air treating material is no longer effective.
[0008] Thus, an object of the present disclosure is to provide a solid air treatment device including a solid air treating material dispenser that is configured with a universal, flexible holder mechanism, which may be configured onto the underside of any sized or shaped lid or cover of any sized or shaped refuse or non-refuse container or receptacle, and that is able to hold any size, shape or configuration of solid air treating material.
[0009] It is another object of the present disclosure to provide an improved air treatment device that keeps any sized or shaped solid air treating material securely placed when installed onto the underside of a refuse or non-refuse container's or receptacle's lid or cover, even upon the eventual drying or shrinking of the air treating material.
[0010] It is another object of the present disclosure to have multiple means of affixing the air treatment device to the underside of a refuse or non-refuse container's or receptacles lid or cover.
[0011] It is another object of the present disclosure to have multiple large perforations to enable increased air-flow through the air treatment device.
[0012] It is another object of the present disclosure to be made of plastic, metal, steel, wood or any other material.
[0013] It is another object of the present disclosure to have a device for indicating the depletion of the air treating material contained within the air treatment device.
[0014] Other objects and advantages of the present invention shall become apparent from the accompanying description and drawings.
SUMMARY
[0015] Accordingly, air treatment devices for use with refuse or non-refuse containers or receptacles are disclosed. The air treatment devices include a cover member and housing member for housing an air treating material. The housing and the cover member include an air treating material therebetween. The housing is rotatably and removably coupled to the cover member and is deformable with respect to the cover. The housing is biased toward the air treating material so as to provide continuous contact of the air treating material and the housing. The housing and the cover component include retaining devices for removably coupling to one another. The air treatment device further includes an indicator device for indicating a period of time. The indicator device may be coupled to the cover component of the air treatment device.
[0016] Additionally, an air treatment system including a housing for securing an air treating material and a retaining device for removably coupling the housing to a refuse or non-refuse container or receptacle is provided. The housing is removably coupled to a cover portion of the refuse or non refuse container or receptacle. The housing includes a biased portion for securely retaining the air treating material, wherein the biased portion retains a constant bias against the air treating material. The air treatment system further includes an indicating device for indicating a time frame and a plurality of through holes for allowing air to contact the air treating material.
[0017] Moreover, an air treatment device including a removably mountable basket and cover coupled to the basket is provided. The basket is deformable with respect to the cover and is biased toward the cover. The cover and basket include respective coupling members, such as flanges, screw threads, rails, detents, projections, tangs and the like. The air treatment device further includes an attachment device for attaching the cover to a refuse or non-refuse container or receptacle. The attachment device may include hook and loop fasteners, fastening clips, tape, adhesive, magnets, suction cups, screws, nails, other hardware and the like.
[0018] Objects and advantages of the present disclosure are set forth in part herein and in part will be obvious therefrom, or may be learned by practice of the present disclosure which is realized and attained by the instrumentalities and combinations pointed out in the appended claims for the devices and methods of the present disclosure consisting of its constituent parts, constructions, arrangements, combinations, steps and improvements herein shown and described.
BRIEF DESCRIPTION OF THE DRAWINGS
[0019] The objects and features of the present disclosure are set forth with particularity in the appended claims. The present disclosure, as to its organization and manner of operation, together with further objectives and advantages may be understood by reference to the following description, taken in connection with the accompanying drawings, in which:
[0020] FIG. 1 is a plan view of an air treatment device in combination with a receptacle in accordance with the present disclosure;
[0021] FIGS. 2A, 2B and 2 C are plan views of the air treatment device of FIG. 1 ;
[0022] FIG. 2D is an enlarged view of FIG. 2A depicting a portion of the air treatment device and freshness indicator in accordance with the present disclosure;
[0023] FIG. 3 is an exploded view of an air treatment device in accordance with the present disclosure;
[0024] FIG. 4 is a perspective view of an air treatment device in accordance with the present disclosure;
[0025] FIG. 5 is a perspective view of a retention ring of the air treatment device in accordance with an embodiment of the present disclosure;
[0026] FIG. 6A is a perspective view of a retaining device of the air treatment device in accordance with an embodiment of the present disclosure;
[0027] FIG. 6B is a side view of the retaining device of FIG. 6A ;
[0028] FIG. 6C is a side view of the retaining device of FIG. 6A in a retaining position;
[0029] FIGS. 7A, 7B and 7 C are plan views of an alternate embodiment of an air treatment device in accordance with the present disclosure;
[0030] FIG. 8 is an exploded view of the air treatment device of FIGS. 7A, 7B and 7 C; and
[0031] FIG. 9 is a perspective view of the air treatment device of FIGS. 7A, 7B and 7 C.
DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS
[0032] The exemplary embodiments of the air treatment devices disclosed are discussed in terms of air treatment devices for use with receptacles and containers including, for example, refuse or non-refuse receptacles and containers. The presently disclosed air treatment devices are contemplated for use as an integral cover or non-integral lid portion of a container or receptacle as well as a portable or stand alone unit for incorporation with a container or receptacle. It is contemplated that the air treatment device of the present disclosure may be employed with, for example, trash barrels as part of a trash barrel lid or cover or a separate unit for attachment to the underside of a trash barrel lid.
[0033] In the discussion that follows, the term trash barrel refers to any type of refuse or non-refuse container or receptacle that is used to collect waste, trash or any other matter and the term cover refers to a cover or lid portion that is used to shield or cover the top open portion of a trash barrel. As used herein, the term “top” generally refers to a portion of the trash barrel or cover that faces or is directed upward (e.g., upward toward the ceiling), while the term “bottom” generally refers to a portion of the trash barrel or cover that faces or is directed downward (e.g., downward toward the floor).
[0034] The following discussion includes a description of an air treatment device used as a trash barrel cover and separate air treatment device for use with a cover or trash barrel. Reference will now be made in detail to the exemplary embodiments of the disclosure, which are illustrated in the accompanying Figures.
[0035] Turning now to the Figures, wherein like components are designated by like reference numerals throughout the several views. Referring to FIG. 1 , there is illustrated a combination air treatment device and refuse receptacle 10 in accordance with the principles of the present disclosure. Air treatment device and refuse receptacle 10 includes a trash barrel 12 , for example, a circular trash barrel having a closed bottom end and open top end for the receiving of refuse or non-refuse waste, trash or other matter. It is contemplated within the present disclosure that trash barrel 12 may include any typical trash barrel for use in home, office or industrial uses and may be of any size, shape or configuration as is well known. An air treatment device 14 may act as a cover for trash barrel 12 or as a separate attachment member to a cover of a trash barrel 12 . Whether acting as a cover of a trash barrel or as an attachment to a cover for a trash barrel, it is contemplated within the present disclosure that the air treatment device 14 may include any size, shape or configuration that can be employed to cover a trash barrel 12 or attach to a cover of a trash barrel.
[0036] With reference to FIGS. 1, 2A , 2 B and 2 C, the air treatment device 14 includes a top 18 , bottom 16 and sidewall 20 portion and may be configured as a separate stand alone, hinged or like member that fits onto or over the open end of trash barrel 12 . Top portion 18 of the air treatment device 14 may include an air freshness indicator means 22 (as described below) for use by a consumer in determining a period of freshness or time. As will be discussed in detail below, bottom portion 16 is designed to incorporate the air treatment device in accordance of the present disclosure.
[0037] The air treatment device 14 may be formed of any size, shape or configuration (e.g., oval, circular, square, rectangular, diamond, octagonal or the like) and be manufactured from any suitable material including, for instance, plastic, metal, steel, wood or the like. The retaining device 44 is preferably perforated with multiple openings in any size, shape or configuration (e.g., tear drops, rectangles, ovals, circles, squares, diamonds, octagons, zig zag patterns or the like) for allowing appropriate air flow to contact air treating material 60 . The air treating material 60 may include an air deodorizer, a disinfectant, an insecticidal component or the like, with or without fragrance, of any size, shape, or configuration (e.g., oval, circular, square, rectangular, diamond, octagonal, or the like) that is capable of being housed between the bottom portion 16 and the retaining member 44 . Moreover, air treating material 60 may be formed as a solid or liquid, for example, a liquid air treating material that is housed by a container or bag as is know in the air treating material art. Any portion of air treatment device 14 including the top 18 , bottom 16 and sidewall 20 may include perforations for allowing air flow.
[0038] Now referring to FIG. 3 , air treatment device 14 is shown in an upside down exploded fashion depicting various portions thereof. More particularly, bottom portion 16 of the air treatment device 14 is bounded by sidewall 20 . Sidewall 20 is designed to fit over or onto a rim portion (not shown) of trash barrel 12 . Bottom portion 16 of the air treatment device 14 includes a flange or retaining member 30 integrally formed thereon. Flange 30 may include retaining ridge or screw thread 32 that is configured for attachment to a retention ring 36 . As best seen in FIG. 5 , retention ring 36 includes flange or screw thread 38 for cooperative attachment to retaining ridge or screw thread 32 of flange 30 within bottom portion 16 of the air treatment device 14 . Alternatively, and as best shown in FIG. 4 , flange 30 may be replaced by retention ring 36 that is integrally molded to bottom portion 16 of the air treatment device 14 . Retention ring 36 includes flange or screw thread 38 for cooperative attachment to a retaining ridge or screw thread 50 of a retaining device or basket 44 (to be discussed below). Referring back to FIGS. 3 and 4 , bottom portion 16 of the air treatment device 14 includes a center portion 28 for placement of solid air deodorizer, disinfectant, insecticide or the like (to be discussed below). Center portion 28 includes a plurality of nubs, nodules or bumps protruding (in the bottom direction of the trash barrel 12 ) from the bottom portion 16 . These nubs may be of varying heights, shapes, sizes and configurations and are configured for allowing air flow between the air treating material 60 and the bottom portion 16 of the air treatment device 14 .
[0039] With reference to FIGS. 3, 4 and 6 A, the basket or retaining device 44 includes a plurality of arm members 46 connected to center portion 48 . Retaining device 44 includes retaining means 50 in the form of flanges, screw threads, detents or the like. Retaining means 50 may include a hinged component where a portion of the retaining device 44 is hingedly connected to the retaining ring 36 or bottom portion 16 of the air treatment device 14 . Retaining means 50 includes receiving surface 52 for receiving flange or screw thread 38 of retention ring 36 . It is contemplated herein that the cooperating elements of retention ring 36 and retaining device 44 may include screw threads, flanges, detents, clips or other removably retaining elements that are configured for the removal of the retaining device 44 from the retention ring 36 . Retaining device 44 may be formed as any shaped housing or basket having one or more air holes or pathways 62 (e.g., holes, slits, mesh and the like) for allowing increased or decreased air flow to the air treating material 60 housed therein.
[0040] Referring to FIGS. 4, 6A , 6 B and 6 C, retaining device 44 is configured to be removably mounted to bottom portion 16 of the air treatment device 14 (via retention ring 36 ). Retaining device 44 is configured to supply a consistent bias in the upward direction to the air treating material 60 housed between the retaining device 44 and bottom portion 16 of the air treatment device 14 ( FIG. 6C ). More specifically, retaining device 44 and/or arms 46 and center portion 48 of retaining device 44 are formed from materials that allow a measure of flexibility and elastic or biased contraction in an upward direction (i.e., toward the bottom portion 16 of the air treatment device 14 ). It is contemplated within the scope of the present disclosure that retaining device 44 may deform, expand or be shaped to accommodate any sized or shaped air treating material 60 . For example, the retaining device may take the shape of a basket or flexible housing. Retaining device 44 may include a plurality the air holes 62 and may be formed from any material providing elastic or biasing functionality such as silicone or rubber based plastics as is well known in the art. It is contemplated that retaining device 44 may further include elastic enhancing devices such as springs (e.g., leaf springs), bungee cords, rubber bands and the like located along or as part of arms 46 and/or center portion 48 .
[0041] In operation and by way of non-limiting example, upon placement of the air treating material 60 (e.g., a solid of a particular size, shape, or configuration) between the bottom portion 16 and retaining device 44 , the retaining device 44 would be biased in an upward direction toward the top portion 18 and thereby continually secures the air treating material 60 between the bottom portion 16 and retaining device 44 components. Upon the gradual evaporation and shrinking of the air treating material 60 , the retaining device 44 would continue to be biased toward the top portion 18 and continue to provide a secure fit of the air treating material 60 .
[0042] The air treatment device 14 and specifically biased retaining device 44 is configured for keeping an air treating material 60 in place (even upon drying or shrinking thereof) when the trash barrel 12 , for example, a trash barrel with a built-in cover, removable cover, push in cover or a built-in foot-pedal activated cover is lifted or activated. Hence, the air treating material 60 is closely held in place and does not rattle, shake or move freely during use of the trash barrel 12 .
[0043] Referring back to FIG. 2D , top portion 18 of air treatment device 14 includes air freshness indicator means 22 for use in indicating a measure of time that is commensurate with the depletion of the air treating material 60 housed within retaining device 44 . More particularly, air freshness indicator means 22 includes a plurality of indicia 24 , for example, the flower petals depicted in FIG. 2D , that change in appearance with a measure of time or with the use of multiple indicia 24 (as depicted in FIG. 2D ) changes in appearance with various measures of time. For example, upon initial placement of air freshness indicator means 22 upon top portion 18 , the indicia 24 may all be identical, that is, indicate one color or configuration. Upon some passage of time that is commensurate with a certain amount of depletion of the air treating material 60 , one or more of the plurality of indicia 24 will change, for example, in color or configuration so as to indicate to a consumer that an amount of time or an amount of air treating material 60 has been depleted. Thus, the consumer will be notified by the indicia 24 that the air treating material 60 needs to be replaced. The air freshness indicator means 22 may also include a reset or on/off button 26 that may be used to reset or turn on or off the timing action of the air freshness indicator means 22 . The air freshness indicator 22 may be of electronic, mechanical or chemical means and may be designed in the shape of a flower (e.g., with petals, with a stem and petals, with petals shaped like hearts, ovals or the like) placed any where on the exterior of the air treatment device 14 . The air freshness indicator 22 is used to indicate to the user the depletion of the air treating material 60 , not only as a function of quality of the air treating material but also as a function of time.
[0044] In an alternate embodiment and as shown in FIGS. 7A, 7B , 7 C, 8 and 9 , wherein like reference numerals represent like components of the air treatment device 14 , a separate or stand alone air treatment device 56 is disclosed. Stand alone air treatment device 56 is configured to attach to trash barrels 12 as an after market add on air treatment feature. The air treatment device 56 is substantially similar to the air treatment device 14 discussed herein. The air treatment device 56 further includes a stand alone housing having a top 118 portion (similar to a top cover and top portion 18 ) and bottom portion 116 (similar to a bottom cover and bottom portion 16 ). Similar to air treatment device 14 , bottom portion 116 includes a retention ring 36 that may either be separate or integrally molded with bottom portion 116 . Retention ring 36 includes retaining means 50 that cooperates with the removable retention of retaining device 44 . The stand alone air treatment device 56 is configured to be attached to any cover or lid of a trash barrel 12 via attachment means 54 . Air treatment device 56 is attached to the cover or lid member through cooperating attachment means 54 such as, for example, hook and loop fasteners, fastening clips, tape, adhesive, magnets, suction cups, screws, nails, other hardware and the like.
[0045] It will be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be construed as limiting, but merely as exemplification of the various embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the claims appended hereto.
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An air treatment device for use with a refuse or non-refuse container or receptacle is provided. The air treatment device includes a cover member and housing member for housing an air treating material. The housing and the cover member include an air treating material therebetween. The housing is rotatably and removably coupled to the cover member and is deformable with respect to the cover. The housing is biased toward the air treating material so as to provide continuous contact of the air treating material and the housing. The housing and the cover component include retaining devices for removably coupling to one another. The air treatment device further includes an indicator device for indicating a period of time. The indicator device may be coupled to the cover component of the air treatment device.
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CROSS-REFERENCE TO RELATED APPLICATIONS
This application is the U.S. National Phase of PCT Appln. No. PCT/EP2012/070543 filed Oct. 17, 2012, which claims priority to German Application No. 10 2011 085 574.2 filed Nov. 2, 2011, the disclosures of which are incorporated in their entirety by reference herein.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to a process for treating a steel surface.
2. Description of the Related Art
Such a treatment is intended to bring about passivation of the corrosion-susceptible surfaces of steel containers, chemical reactors, pipes, distillation columns, steel supports, etc. In particular, the invention relates to the passivation of surfaces in chemical plants or plant components which come into contact simultaneously with residual moisture, chlorine, hydrogen chloride [P. M. Bhadha, E. R. Greece: Joule-Thomson Expansion and Corrosion in HCl Systems in Solid State Technology July 1992 pp. 3-7], chlorosilanes, hydrogen and reactive elemental silicon.
It is known that residual moisture in gases and/or stainless steel plants causes corrosion in the presence of hydrogen chloride [J. Y. P. Mui: Corrosion Mechanism of Metals and Alloys in the Silicon-Hydrogen-Chlorosilane System at 500 C in Corrosion—NACE, 41(2), 1985 pp. 63-69; W. C. Breneman: Direct Synthesis of Chlorosilanes and Silane in Catalyzed Direct Reactions of Silicon, Elsevier 1993 pp. 441-457, in particular table 3 on p. 454].
A natural corrosion protection on the surface of carbon steel or of stainless steel can be formed at above 500° C. in the reductive atmosphere of a chlorosilane-hydrogen chloride-hydrogen mixture. This also applies to SiC-coated carbon steel.
In stainless steel containers, the steel is usually tested for chloride stress cracking corrosion.
Hydrogen chloride chlorinates phosphorus-containing constituents of the steel alloy [H. Viefhaus, B. Richarz: Phosphor in Eisen and Stahl in Materials and Corrosion, 46, 1995 pp. 306-316], as a result of which phosphorus chlorides are formed and these either contaminate, as volatile contamination, the silane stream or can react with silanes or boron compounds to form undefined adducts which cannot be separated from the products in the purification of chlorosilanes by distillation [Xiao Ji-mei, Shen Hua-sheng: The Theoretical Aspects of Preventing Corrosion of Stainless Steel . . . in the Production of Polycrystalline Silicon in Xiyou-jinshu—Rare Metals, Chin. Vol 1-2, 1982 pp. 3-15, in particular equation (44) and pp. 13-15].
In the reductive hydrogen atmosphere of a deposition of polycrystalline silicon (Siemens process U.S. Pat. No. 7,708,970 B2; chlorosilane and hydrogen as starting materials), phosphorus chlorides are reduced and phosphorus is preferentially incorporated into the deposited polycrystalline silicon.
Passivation of the steel surface can slow or prevent both the moisture and the reductive corrosion.
It is known from JP7090288 A2 and U.S. Pat. No. 2,985,677 A that silicon-organic halogen compounds are chemisorptively bound as silyl esters to active Fe—OH sites on steel surfaces, so that they can be used as oil-free lubricants in the working of steel sheets.
JP8010703 A2 discloses polysiloxanes from the hydrolysis and condensation of organic chlorosilanes as primers for corrosion protection constituents and as corrosion protection resins.
DE 3920297 A1 describes heteropolycondensates of siloxy-aluminate esters with organosilanes bearing hydrolyzable radicals, optionally with addition of organofunctional silanes with silicic esters, as corrosion protection. The corrosion protection is in this case brought about by dipping into a silanization bath and subsequent drying. Drying is carried out at at least 50° C.
SUMMARY OF THE INVENTION
It is an object of the present invention to achieve homogeneous passivation from the vapor/gas phase without dipping or spraying and without after-treatment. In addition, passivation should occur at a surface temperature of 50° C. or less. These and other objects are achieved by the invention, which passivates by the use of a group of functional silanes which can react with active steel surfaces even at relatively low temperatures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The invention provides for the use of compounds of the general formula
R n Z p SiX (4−n−p)
for the treatment of steel surfaces;
where X is selected from the group consisting of H, OH, halogen, alkoxy (C1-C3), acyloxy (C1-C3) and NR 1 R 2 , where R 1 and R 2 are each selected from the group consisting of H, methyl and ethyl;
where R is selected from the group consisting of straight-chain and/or branched alkyl radicals C1-C6, straight-chain and/or branched alkenyl radicals C1-C6 or aryl radicals C1-C6, optionally interrupted by O, S;
where Z is an organofunctional group which is bound via an (optionally branched and/or unsaturated) C1-C6-alkylene radical and is selected from the group consisting of halogen, optionally substituted amino group, amide, aldehyde, alkylcarbonyl, carboxy, hydroxy, mercapto, cyano, alkoxy, alkoxycarbonyl, sulfonic acid, phosphonic acid, phosphate, acryloxy, methacryloxy, glycidyloxy, epoxy and vinyl groups;
where n=0, 1 or 2 and p=1, 2 or 3 and 3≧(n+p)≧1;
where the compound of the general formula (1) contains not more than 20 carbon atoms.
The invention provides a corrosion-inhibiting surface treatment of phosphorus-containing steel surfaces, which can be carried out more simply and under milder conditions than is known from the prior art; in particular, the treatment can be carried out on installed steel objects having undercuts (pipes, containers, apparatuses, etc.) in the case of which a dipping or spray process could be carried out only with great difficulty.
In addition, significantly smaller amounts are required for the surface treatment than in the case of, for example, dipping or flooding processes, which improves the economics and reduces environmental pollution.
Here, the steel surface to be treated is brought into contact at a surface temperature of less than 50° C. with vapor of the compounds of the general formula 1 or mixtures thereof.
A solvent which is inert under the use conditions, for example, one selected from among alcohols (methanol, ethanol, isopropanol), ethers (dimethyl ether, diethyl ether, diisopropyl ether, dioxane, tetrahydrofuran), ketones (acetone, methyl ethyl ketone [MEK]), linear or branched alkanes (n-butane, n-pentane, n-hexane, n-heptane) and alkane mixtures (petroleum ether having a boiling range from 40 to 60° C.), halogenated alkanes (chloromethane, dichloromethane, trichloromethane, tetrachloromethane, chloroethane), aromatics (benzene, toluene, o-xylene, pyridine), optionally substituted aromatics such as methoxybenzene, chlorobenzene or hexamethyldisiloxane) is preferably present.
Preference is given to using a solvent having a boiling point at the pressure of the surrounding atmosphere of less than 150° C., more preferably less than 100° C., and most preferably less than 70° C.
Examples of X in the compounds of the general formula (1) include fluorine, chlorine, bromine, methoxy, ethoxy, acetoxy, 2-chloroethoxy, and 2-methoxyethoxy.
Particular preference is given to chlorine, methoxy, ethoxy, acetoxy groups and especial preference is given to the methoxy group.
Examples of R in the compounds of the general formula (1) include
methyl, ethyl, and phenyl groups.
Particular preference is given to methyl and ethyl groups, most preferably the methyl group.
Examples of Z in the compounds of the general formula (1) include
dichloromethyl, chloromethyl, 2-chloroethyl, 3-chloropropyl, aminomethyl, 3-aminopropyl, 3-N-(2-aminoethyl)aminopropyl, N-(2-aminoethyl)aminomethyl, N,N-dimethylaminomethyl, N,N-diethylaminomethyl, N-butylaminomethyl, 3-thiopropyl, cyanoethyl, N-((trimethoxysilyl)methyl)aminomethyl, N-phenylaminomethyl, N-cyclohexylaminomethyl, hydroxymethyl, methoxymethyl, ethoxymethyl, 3-glycidoxypropyl, 3-acryloxypropyl, and methacryloxymethyl.
Preferred are 3-aminopropyl, N-(2-aminoethyl)aminomethyl, and N,N-diethylaminomethyl, and
Particularly preferred are N-(2-aminoethyl)aminomethyl, N,N-diethylaminomethyl
Examples of compounds of the general formula (1) include
(MeO) 3 Si—CH 2 —C 1 , (MeO) 2 MeSi—CH 2 —C 1 , (MeO) 3 Si—(CH 2 ) 3 —C 1 , (MeO) 3 Si—CHCl 2 , Me(MeO) 2 Si—(CH 2 ) 2 —CF 3 Cl 3 Si—CH 2 —C 1 , Cl 2 MeSi—CH 2 —C 1 , F 3 Si—(CH 2 ) 3 —C 1 , (MeO) 3 Si—CH 2 —OMe, (MeO) 2 MeSi—CH 2 —OMe, (MeO) 3 Si—(CH 2 ) 3 —OMe, (MeO) 3 Si—CH 2 —NH 2 , (MeO) 2 MeSi—CH 2 —NH-Et, (MeO) 3 Si—(CH 2 ) 3 —NH 2 , (EtO) 3 Si—CH 2 —NHBu, (EtO) 2 MeSi—CH 2 —NH-Et, (MeO) 3 Si—(CH 2 ) 3 —NH 2 , (MeO) 3 Si—CH 2 —NH—CH 2 CH 2 —NH 2 , (MeO) 2 MeSi—CH 2 —N(Et) 2 , (MeO) 3 Si—(CH 2 ) 3 —NH—CH 2 CH 2 —NH 2 , (MeO) 3 Si—(CH 2 ) 3 —SH, Me(AcO) 2 -Si—CH 2 —C 1 , (MeO) 3 Si—(CH 2 ) 2 —CN, Me(MeO) 2 Si—CH 2 -NHPh, (MeO) 3 Si—CH 2 —NHPh, (C 1 —CH 2 CH 2 —O) 2 MeSi—CH 2 Cl, (EtO) 3 Si—CH 2 —N(Bu) 2
and also the cyclic compounds formed by intramolecular condensation (optionally in admixture with the open-chain silanes)
and also the dimers and oligomers formed by intermolecular condensation (optionally in admixture with the open-chain silanes and/or abovementioned cyclic compounds):
Preference is given to using amino-functional alkoxysilanes.
Very particular preference is given to using alpha-amino-functional alkoxysilanes.
To ensure a very high volatility, monomers of the compounds of the general formula 1 are preferably used.
The compounds of the general formula 1 preferably contain not more than 12 carbon atoms, more preferably not more than 9 carbon atoms.
Procedure for surface treatment: the vapor required for the treatment is, for example, produced either by vaporizing the silane (or mixture, optionally in the presence of a solvent) by heating in an apparatus (vaporizer) or by passing an optionally heated gas (N2, He, Ar, air) through the liquid, optionally heated silane (or mixture, optionally in the presence of a solvent) (saturator) and conveyed onto the surface to be treated.
This is achieved either via pipes or apparatuses connected directly to the apparatus or within the apparatus, or the object to be treated is placed in a chamber which is supplied with the vapor.
To avoid condensation of the vapor and thus an accumulation in the vicinity of the entry point, it can, particularly in the case of the treatment of interior spaces of apparatuses having a large length/diameter ratio, be useful to heat the surfaces before and during the treatment process.
Aerosols can also be used and the same applies to these. They can easily be produced by means of, for example, ultrasound emitters and conveyed by means of a gas stream onto the surface.
Treatment with mixtures of aerosol and vapor is also conceivable.
The treatment time depends on the vaporizable amount of silane and the size of the surface to be treated.
The treatment process can easily be monitored by detection of the vapor/aerosol/gas stream exiting from the apparatus. For example, acidic and basic silanes can be detected by means of moist indicator paper. Excess silane can simply be condensed out by means of a condenser at the outlet opening and thus be recovered. This procedure allows a recycle mode of operation in which the amount of the silane applied to the surface can be determined by simple backweighing and in addition ensures that environmental pollution is kept very low. However, excess silane can also be collected by means of scrubbers or adsorbers.
According to experience, siloxane coatings are thermally stable up to about 300° C., see, for example, W. Noll: Chemie und Technologie der Silicone, Verlag Chemie, Weinheim 1960, page 151.
Corrosion can therefore be slowed even at 200° C.
The invention thus makes possible at least temporarily passivating coating of corrosion-sensitive steel surfaces by means of a surface treatment at temperatures of less than 50° C. against the corrosive atmosphere of a gas mixture of residual moisture, chlorine, hydrogen chloride, chlorosilanes, hydrogen and optionally reactive elemental silicon.
The passivation reduces the phosphorus extraction rate, i.e. also reduces the phosphorus content of the polycrystalline silicon deposited in the steel plant, so that start-up of such plants can be accelerated without endangering quality. Particularly in closed systems for deposition of polysilicon by means of chlorosilanes which in combination with moisture bring about corrosion effects on steel surfaces, the use displays great advantages, e.g. in the hydrogen recycle gas or in chlorosilane condensation systems.
EXAMPLES
A comprehensive trial using different silanes and derivatives thereof was carried out.
Coated and uncoated steel specimens were subsequently exposed to a corrosive atmosphere composed of moist hydrogen chloride (hydrochloric acid).
The steel samples were cleaned with deionized water and dried using acetone before treatment with the respective compound. Between the individual treatment steps, the steel specimens were stored in an inert atmosphere in a desiccator to protect them against environment influences, in particular atmospheric moisture. The steel specimens were weighed before commencement of the first treatment step, and likewise after each of the individual treatment steps. Finally, the weight loss caused by corrosion was determined on the test specimens. The documentation of the state of the test specimens as a function of the experimental conditions selected (silane, material, treatment time, etc.) was carried out by means of photos, by optical microscopy and by SEM.
The individual treatment steps after cleaning and documentation of the initial state have been carried out are described below.
The test specimens were placed in a desiccator and stored over the respective silane at an ambient temperature of 40° C.
The steel specimens which had been pretreated with silane and also in each case a comparative specimen were stored over concentrated hydrochloric acid for a) 48 hours or b) 4 hours, in each case at 40° C. This treatment step makes it possible to simulate corrosive conditions as prevail in the case of the steel bodies described at the outset.
After each treatment step, the specimens were examined by electron-microscopic methods and analyzed and assessed by optical-microscopic methods and by EDX (energy dispersive X-ray).
Various corrosive attacks were assessed on the ground surfaces of the specimens as a function of the silane used and the treatment time.
Differently pretreated steel specimens of two types of material were used: austenitic chromium-nickel stainless steel and carbon steel alloys.
The specimens were pretreated: either only pickled, or pickled and surface-ground.
For pickling the materials, the following pickling solutions were used:
20 parts by volume of hydrochloric acid (1.18 g/cm 3 =37% by mass),
3 parts by volume of nitric acid (1.39 g/cm 3 =65% by mass), 77 parts by volume of water.
The bath temperature did not exceed 50° C. The removal of material was ≦3 μm.
After pickling, the parts were rinsed with tap water (chlorine ion content ≦50 ppm) until acid could no longer be found on the pickled parts. Neutrality was confirmed by means of indicator paper.
Conventional grinding disks or rotor blade grinders were utilized for surface-grinding.
The grain size to be selected was adapted stepwise and in a suitable form to the grain size of the final ground surface and the cleaning effect.
The surface treatment was carried out with an average peak-to-valley height of Rz≦4 μm. This peak-to-valley height can generally be achieved by grinding using a grain size of 240 or finer.
In the case of the reference specimens, no treatment with a silane or with a cyclic aza compound was carried out.
For the other specimens, the following silanes were used:
Diethylaminomethyltrimethoxysilane, H-triethoxysilane, TM 10/47-2 (reaction product of Si(OEt) 4 and SiCl 4 (by GC: 52% of ClSi(OEt) 3 , 12% of Cl 2 Si(OEt) 2 ), 35% of Cl 3 Si(OEt)), N,N-diethylaminomethyl)dimethoxymethylsilane (97.8 GC-%) and (2-aminoethyl)aminomethyltrimethoxysilane (93.3 GC-%) and the corresponding cyclic aza compound (4.5 GC-%)−GC=Gas Chromatograph.
TABLE 1
Table 1 shows the structures of the silanes examined.
Compound
Structure
Diethylaminomethyltri-
Et 2 N—CH 2 —Si(OMe) 3
methoxysilane
H-Triethoxysilane
HSi(OEt) 3
TM 10/47-2
Reaction product of
Si(OEt) 4 and SiCl 4
(according to GC: 52%
ClSi(OEt) 3 , 12%
Cl 2 Si(OEt) 2 , 35%
Cl 3 Si(OEt)
(N,N-Diethylaminomethyl)di- methoxymethylsilane (97.8 GC-%)
(2-Aminoethyl)aminomethyl- trimethoxysilane 93.3 GC-%) and the corresponding cyclic aza compound (4.5 GC-%)
The structures were in each case confirmed by means of 1 H- and 29 Si-NMR.
As comparative specimen, the steel specimen made of the appropriate material which had been pretreated but not conditioned with a silane was used in each case.
The steel specimens were cleaned with deionized (DI) water, rinsed with acetone and dried before the treatment with the appropriate compound.
Between the individual treatment steps, the steel specimens were stored in an inert, e.g. nitrogen, atmosphere in a desiccator for protection against environmental influences, in particular atmospheric moisture.
The steel specimens were weighed before commencement of the first treatment step and likewise after each of the individual treatment steps.
Finally, the weight loss caused by corrosion was determined on the test specimens.
The documentation of the state of the test specimens as a function of the selected experimental conditions (silane, material, treatment time, etc.) was carried out by means of photos, by optical microscopy and by means of SEM.
The individual treatment steps after cleaning and documentation of the initial state had been carried out are described below.
The test specimens were placed in a drier (desiccator) and stored over the appropriate silane at an ambient temperature of 40° C. for 48 hours. The steel specimens which had been pretreated with silane and also in each case a comparative specimen were stored over hydrochloric acid (36% by mass) for a) 48 hours or b) 4 hours, in each case at 40° C.
Corrosive conditions as prevail in the pipes described at the outset can be simulated by this treatment step.
Tables 2 and 3 show the results.
TABLE 2
Treatment at 40° C. for 24 h.
Treatment
Pre-
Treatment with
with HCl
treatment
silane
40° C.
40° C.
Result
No.
Material
A, B
U
S1
S2
S3
S4
S5
24 h
4 h
G
O
B
1
M1
A
x
x
2.3
3
2
M1
A + B
x
x
2.0
3
5
M2
A
x
x
1.2
3
6
M2
A + B
x
x
1.7
3
9
M1
A
x
x
1.3
3
10
M1
A
x
x
2.4
3
11
M1
A
x
x
1.7
3
14
M1
A + B
x
x
2.1
3
15
M1
A + B
x
x
3.6
3
16
M1
A + B
x
x
3.8
3
19
M2
A
x
x
1.8
3
20
M2
A
x
x
1.9
3
21
M2
A
x
x
2.8
3
24
M2
A + B
x
x
1.7
3
25
M2
A + B
x
x
1.8
3
26
M2
A + B
x
x
2.8
3
TABLE 3
Treatment at 40° C. for 4 h.
Treatment
Pre-
Treatment with
with HCl
treatment
silane
40° C.
40° C.
Result
No.
Material
A, B
U
S1
S2
S3
S4
S5
24 h
4 h
G
O
B
3
M1
A
x
x
3.0
x
2
4
M1
A + B
x
x
4.4
x
3
7
M2
A
x
x
3.7
x
2
8
M2
A + B
x
x
4.9
x
3
12
M1
A
x
x
2.8
x
1
13
M1
A
x
x
2.9
x
1
17
M1
A + B
x
x
2.6
x
1
18
M1
A + B
x
x
3.4
x
1
22
M2
A
x
x
2.8
x
1
23
M2
A
x
x
2.6
x
1
27
M2
A + B
x
x
2.9
x
1
28
M2
A + B
x
x
2.7
x
1
Legend for Tables 2 and 3
Materials
M1 Chromium-nickel stainless steel M2 Carbon steel
Pretreatment
A Pickled B Surface-ground
Treatment with Silane
U Untreated reference specimens S1 Diethylaminomethyltrimethoxysilane S2 H-Triethoxysilane S3 TM 10/47-2 S4 N,N-(Diethylaminomethyl)dimethoxymethylsilane (97.8 GC-%) S5 (2-Aminoethyl)aminomethyltrimethoxysilane (93.3 GC-%) and the corresponding cyclic aza compound (4.5 GC-%)
Results
G Weight loss [mg/h] after treatment with HCl O Optical examination [optical microscopy, SEM (energy dispersive X-ray)]
Example of optical examination: enlargement stages 3.2×(optical microscope, reflected light, coaxial illumination) to 500× and EDX analysis.
Above a magnification of 50×, a scanning electron microscope was used.
B Evaluation
1 Slight corrosion=undetectable grinding tracks 2 Corrosion=detectable grinding tracks 3 Severe corrosion
Evaluation was carried out in respect of pickled-away, undetectable grinding tracks, detectable scratches, holes, etc. Qualitative assessment was carried out by means of SEM. Quantitative evaluation was carried out via the weight loss.
The results show that after a process according to the invention, the steel support bodies treated with silane and cyclic aza compound vapors at 40° C. display significantly better corrosion resistance than do untreated support bodies.
In addition, it was able to be shown that uniform application of the silane protective layer is ensured.
Notably, corrosion could be significantly reduced compared to the untreated specimens under the conditions according to the process.
This is reflected not only in the reduced weight decrease (gravimetric determination) but also in the optical examination of the treated test specimens which had been exposed to corrosive conditions.
Typical surface-ground structures which are largely retained even after the corrosive treatment step in the specimens treated with (2-aminoethyl)aminomethyltrimethoxysilane (93.3 GC-%) and the corresponding cyclic aza compound (4.5 GC-%) support and reinforce the gravimetric findings.
Comparative Example
A freshly installed pipe made of carbon steel and having a length of 87 m and a diameter of 250 mm was used without surface treatment after flushing with nitrogen at 10,000 m 3 /h for one day.
This steel pipe was supplied with 9980 standard m 3 /h of hydrogen and operated in the gas recycle mode.
The foreign gas components were found to be HCl at 0.8% by volume and moisture at 0.14 ppmv.
Of this hydrogen stream, 1930 standard m 3 /h were passed into or through a running Siemens reactor for deposition of polysilicon from trichlorosilane.
A phosphorus content of 400 ppta was measured in the first polysilicon rods deposited.
The phosphorus contamination of the polysilicon rods was able to reach the specified value of less than 40 ppta only after 30 days, after the eighth batch.
Example
A freshly installed steel pipe made of carbon steel and having a length of 89 m and a diameter of 250 mm was flushed with 10,000 standard m 3 /h of nitrogen saturated with (2-aminoethyl)aminomethyltrimethoxysilane (93.3 GC-%) for 24 hours at 25-28° C.
After this treatment, the pipe was supplied with 10,000 standard m 3 /h of hydrogen and operated in the gas recycle mode.
The foreign gas components were found to be HCl at 0.9% by volume and moisture at 0.14 ppmv.
Of this hydrogen stream, 1940 standard m 3 /h were passed into or through a running Siemens reactor for deposition of polysilicon from trichlorosilane.
A phosphorus content of 100 ppta was measured in the first polysilicon rods deposited and even the second batch achieved the specified value of 40 ppta.
|
The content of phosphorus in polycrystalline silicon prepared by the Siemens process is reduced by treating phosphorus-containing steel surfaces with an α-amino-functional alkoxysilane. The treated surface exhibits less corrosion in an atmosphere of moist hydrogen chloride, and less loss of phosphorus as a result.
| 2
|
BACKGROUND OF THE INVENTION
The present invention relates to thermistors which measure the surface temperature of electronic devices and which are used in temperature compensation for the same. More particularly, the invention relates to chip-type thermistors, such as those adapted for surface mounting on printed circuit boards.
A prior art chip-type thermistor includes a thermistor element having silver-palladium electrodes fused at both ends thereof. The palladium imparts soldering heat resistance to the electrode, thereby preventing the silver from dissolving when soldering a chip-type thermistor to a substrate.
A drawback of the prior art is that palladium decreases the solder adhesion of the electrode to the substrate, thereby establishing an upper limit on the amount of palladium which can be used. When soldering the electrode at high temperature continues for a long period of time, however, limit amount of palladium is insufficient to impart adequate soldering heat resistance to the electrode.
The prior art thermistor improves soldering heat resistance and soldering adhesion by providing a plating layer on the surface of the electrodes, as in the case of a chip-type capacitor. A drawback of this technique is that, since a thermistor element is electrically conductive (unlike the capacitor), plating a conductive material directly on the surface of the thermistor element alters the resistance value of the thermistor element from the desired or expected value. In addition, a portion of the thermistor element is eroded by the plating liquid, thereby reducing the life and reliability of the thermistor.
Referring to FIGS. 10, 11(a) and 11(b), Japanese Laid-Open Patent Publication No. 3-250,603 discloses a chip-type thermistor 5 which attempts to overcome the above drawbacks. A thermistor element 1 includes a glass layer 2 covering all but the ends of thermistor element 1. An electrode layer 4 is baked on the ends of thermistor element 1. Glass layer 2 has a softening point approximately equivalent to the baking temperature of a baked-on electrode layer 4. A protective plating layer (not shown) covers baked-on electrode layer 4. The protective plating layer may be, for example, nickel.
Although chip-type thermistor 5 has good solder adhesiveness, good solder heat resistance and could decrease discrepancies in resistance values, problems occur because the softening point of glass layer 2 is approximately the same as the baking temperature of baked-on electrode layer 4.
Referring now also to FIGS. 11(a) and 11(b), glass layer 2, at the edge of thermistor element 1, softens when baked-on electrode layer 4 is baked on to glass layer 2 and thermistor element 1. This permits glass layer 2 to flow easily downward from the edge. In extreme cases, glass layer 2 disappears from the edge area and causes thermistor element 1 to be left exposed. In addition, the shape of glass layer 2 is often distorted during processing.
Referring specifically to FIG. 10, another problem is that during the baking on of baked-on electrode layer 4, thermistor element 1 may be placed on baking tools such as a baking platform or a baking sheath. Furthermore, a group of chip-type thermistors 5 can be baked at the same time. This can cause glass layer 2 to melt and stick to the baking tools or to other chip-type thermistors, leaving a contact mark or a melt mark 3 on glass layer 2.
Referring to FIG. 11(b), a further problem is that the glass frit, which is melted to form baked-on electrode layer 4 reacts with glass layer 2. The glass frit melts into glass layer 2 and, in extreme cases, both glass layer 2 and baked-on electrode layer 4 flow away at the edge of thermistor element 1, again, leaving thermistor element 1 exposed.
Japanese Laid-open publication No. 3-250604 discloses a thermistor made of a glass containing crystals of inorganic compounds such as alumina, zirconia and magnesia. The glass and the inorganic crystals are mixed together in a powder state. An organic binder and solvent are added to this mixture to create a paste. This paste is printed and baked onto the thermistor element, forming a glass layer. The above-noted problem is solved because the presence of the inorganic crystal powder in the glass layer of this thermistor increases the softening point of the resulting glass layer as compared to the glass layer for the thermistor formed by Japanese Laid-open publication No. 3-250603.
A drawback of the thermistor made by Japanese Laid-open publication No. 3-250604 is that it is difficult to mix uniformly the inorganic crystal powder and the glass powder. The resulting paste is difficult to print on to the thermistor element and results in non-uniform distribution over the surface of the thermistor element.
A further drawback is that bubbles are formed and remain in the glass layer because of the presence of the inorganic crystals. The bubbles tend to burst and become open pores. This allows plating fluid to infiltrate into the pores during the plating process. The plating fluid erodes the thermistor element and decreases the reliability of the thermistor. Finally, the surface of the glass layer becomes irregular and uneven due to the baking on of the baked-on electrode layer. This damages the appearance and changes the expected resistance value of the thermistor.
OBJECTS AND SUMMARY OF THE INVENTION
Accordingly, it is an object of the invention to provide a thermistor element which overcomes the drawbacks of the prior art.
It is a further object of the present invention to provide a thermistor with a glass layer and a baked-on electrode layer having good shape-maintaining qualities.
It is a still further object of the present invention to provide a thermistor with a glass layer and a baked-on electrode layer such that the glass layer or the baked-on electrode layer at the edge of the thermistor element is not destroyed during the baking process.
It is still a further object of the present invention to provide an aesthetically pleasing thermistor with a flat and smooth glass layer surface.
It is yet still a further object of the present invention to provide a thermistor with a glass layer that does not have contact marks or melt marks on the thermistor surface caused by various baking tools.
It is yet a further object of the invention to provide a thermistor with increased soldering heat resistance and soldering adhesion.
It is yet a still further object of the invention to provide a thermistor having terminal electrodes which minimizes the change in resistance values due to plating.
It is yet a further object of the present invention to provide a thermistor that is strong against tensile stress caused by heat stress.
Briefly stated, the present invention provides an insulating glass layer covering the surface of a thermistor element except at the two end surfaces. The insulating glass layer is partially or fully composed of crystallized glass. A terminal electrode is integrally formed on both end surfaces. The terminal electrodes include a baked-on electrode layer formed from a conductive paste. Layers of nickel and tin or lead/tin are plated onto the baked-on electrode. The insulating glass layer enhances shape-maintainability of the insulating glass layer and the baked-on electrodes, provides a smoother glass surface, resulting in a more aesthetically pleasing thermistor, prevents resistance variance due to plating of the baked-on electrodes and provides a strong anti-breaking strength thermistor. The coefficient of thermal expansion of the glass layer is less than the coefficient of thermal expansion of the thermistor element. This difference in coefficients of thermal expansion tends to help the thermistor element resist stress breakage.
According to an embodiment of the invention, there is provided a thermistor comprising: a thermistor element having first and second opposed end surfaces, and first, second third and fourth peripheral sides, an insulating glass layer on the first, second third and fourth peripheral sides, the first and second opposed end surfaces being substantially free of the insulating glass layer, the insulating glass layer being at least partially crystallized glass, and a terminal electrode on each of the first and second opposed end surfaces.
According to a feature of the invention, there is provided a method for producing a thermistor, comprising: preparing a ceramic sintered sheet having a pair of opposing surfaces, covering the pair of opposing surfaces of the ceramic sintered sheet with a glass paste, baking the ceramic sintered sheet at a predetermined temperature to form an insulating glass layer composed at least partially of crystallized glass layer, cutting the ceramic sintered sheet into a plurality of strips each having a pair of longitudinal side surfaces, covering the pair of longitudinal side surfaces with the glass paste, cutting the plurality of strips into a plurality of chips each having a pair of uncovered ends, applying a conductive paste to each of the pair of uncovered ends, and baking the plurality of chips to form a baked-on electrode layer on each of the pair of uncovered ends.
According to a further feature of the invention, there is provided a thermistor comprising: a thermistor element, the thermistor element including first, second, third and fourth contiguous peripheral sides, an insulating glass layer on the first, second, third and fourth contiguous peripheral sides, and the insulating glass layer having a coefficient of thermal expansion that is less than a thermal expansion of the thermistor element.
The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a perspective view, partially in cross section, of a thermistor according to a first embodiment of the present invention.
FIG. 2 is a longitudinal cross-sectional view of the first embodiment taken along line A--A in FIG. 1.
FIGS. 3(a)-3(f) illustrate the steps for manufacturing the embodiment of FIG. 1.
FIG. 4 is a longitudinal cross-sectional view of a thermistor having an internal resistance regulating electrode according to a second embodiment of the present invention.
FIG. 5 is a longitudinal cross-sectional view of a third embodiment of the present invention.
FIG. 6(a)-6(f) illustrates the steps for manufacturing the embodiment of FIG. 4.
FIG. 7 is a longitudinal cross-sectional view of a fourth embodiment of the present invention.
FIG. 8 is a longitudinal cross-sectional view of a fifth embodiment of the present invention.
FIG. 9 is a longitudinal cross-sectional view of a sixth embodiment of the present invention.
FIG. 10 is a perspective view of a prior art thermistor.
FIG. 11(a) is an enlarged cross-sectional view taken along line B--B.
FIG. 11(b) is an enlarged cross-sectional view taken along line C--C.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIGS. 1 and 2, a thermistor 10 includes a thermistor element 13. Thermistor element 13 is covered by an insulating glass layer 14, which covers the entire surface of thermistor element 13 except for a pair of end surfaces 31. A pair of terminal electrodes 12 are formed on end surfaces 31 of thermistor 10. Each of the terminal electrodes 12 includes a baked-on electrode layer 16, a Ni plating layer 18 and a Sn or a Sn/Pb plating layer 19.
Insulating glass layer 14 is either partly or entirely made of crystallized glass. The glass transition point of this glass, before it is heat treated for crystallization, is in the range of about 400 to about 1,000 UC. The crystallizing temperature is higher than the glass transition point of the glass. This is described in more detail below.
Referring to FIGS. 3(a)-3(f), the above embodiment is manufactured as follows. Referring specifically to FIG. 3(a), a ceramic sintered sheet 11 is prepared from one or a mixture of two or more-metal oxides. For example, the metal oxides can be Mn, Fe, Co, Ni, Cu, or Al. The mixture is pre-heated, crushed and mixed with an organic binder and formed into a block. The block is heated to its sintering temperature to form a ceramic sintered body (not shown). The ceramic sintered body is then cut to form a plurality of sheets 11.
Referring now to FIG. 3(b), ceramic sintered sheet 11 is coated on both sides with frit precursor to an insulating glass layer 14. The combination is then baked to form insulating glass layer 14.
Referring now to FIG. 3(c), coated ceramic sintered sheet 11 is cut by any convenient means such as, for example, a handsaw, a dicing saw, or a cutter with a diamond blade to form strips 35. Cut strips 35 now have exposed sides 32 in which ceramic sintered sheet 11 and insulating glass layers 14 can be seen.
Alternatively, after the pre-heating and crushing steps, the resulting powder can be milled with an organic binder and a solvent to form a slurry. The resulting slurry is then spread by, for example, a doctor blade, to form a green sheet, which is then dried to form a membrane. The green sheet is baked at sintering temperature to form ceramic sintered sheet 11. The remainder of the steps for this embodiment are the same as described.
Referring to FIG. 3(d), a glass paste is printed on the now exposed sides 32 of thermistor element 13. The glass paste on exposed sides 32 is baked to form an insulating glass layer 14' covering the two exposed sides 32 of strip 35.
Referring now to FIG. 3(e), each strip 35 is cut perpendicular to its long axis to form chips 15 having exposed end surfaces 31.
Referring to FIG. 3(f), a conductive paste, composed of an inorganic binder and a conductive material such as, for example, a precious metal powder, is applied to end portions of chip 15, including end surfaces 31. The chips are heated to bake the conductive paste and thus to form baked-on terminal electrodes 16. Baked-on terminal electrodes 16 are completed to form terminal electrodes 12 by covering baked-on terminal electrodes 16 with a Ni plating layer and a Sn or a Sn/Pb plating layer over the Ni plating layer (the Ni and Sn/Pb plating layers are not shown separately in FIGS. 3(a)-3(f).
Insulating glass layer 14 is composed in part or entirely from crystallized glass. Generally, insulating glass layers 14 and 14' have thicknesses of approximately 10-30 microns. If insulating glass layer 14 is partially crystallized glass, a crystallization of at least 10% is desirable for the present invention to achieve its objective.
Crystallized glass is a glass ceramic made from baking a uniform non-crystal glass at a time and temperature schedule near the softening point of the uniform non-crystal glass, thereby creating collections of fine crystals. In order to make crystallized glass, a non-crystallized glass powder (raw glass powder) is selected and combined with the glass paste in a proportion that enables crystallization. The dried glass paste is baked at a specified temperature effective to crystallize a desired portion of the glass contained in the glass paste.
The glass in insulating glass layers 14 and 14 ', prior to the heat treatment, have a glass transition point in the range of 400-1,000 UC. The crystallization temperature of the glass is higher than the transition point of the glass.
The transition point of the glass in insulating glass layer 14 is determined by the baking temperature of baked-on electrode layer 16. If Ag is used in baked-on electrode layer 16, the baking temperature is from 600-850 UC. If the transition point of the glass is significantly lower than this temperature, the crystallized glass can degenerate during baking of baked-on electrode layer 16. For example, when the pre-crystallized glass transition point is below 400° C., the crystallization temperature can be lower than 600 UC. When the transition point of the pre-crystallized glass is over 1000 UC, the crystallization temperature exceeds 1000 UC. The resulting high baking temperature can degrade the electrical characteristics of thermistor element 13.
The desired coefficient of thermal expansion for the crystallized glass is from 40 to 100 percent of the coefficient of thermal expansion for thermistor element 13. The preferred range is from 50 to 90 percent. The coefficient of thermal expansion is important in determining the anti-breaking strength of the thermistor.
The term "anti-breaking strength" refers to the disruptive strength, tested by placing the ends of thermistor 10 on spaced-apart platforms and by applying a load in the center of thermistor element 13 until thermistor element 13 breaks. Anti-breaking strength is an index to the amount of resistance thermistor 10 has to the stress (mechanical stress) from the mounting device when thermistor 10 is mounted on a printed circuit board or to stress strain (heat stress) that is caused by heat from soldering or from the in-use heat cycle after mounting is completed.
When the coefficient of thermal expansion of the crystallized glass is in a preferred range between about 40 and 100 percent, the anti-breaking strength is greater than that of a thermistor without a glass layer. It is also greater than that of a thermistor with a glass layer made of uncrystallized glass, having a coefficient of thermal expansion within the above range.
When the coefficient of thermal expansion of the crystallized glass is in a more preferred range between about 50 to 90 percent, the anti-breaking strength is from about 20 to about 70 percent greater than a thermistor having no glass layer or a thermistor with a glass layer made of uncrystallized glass. If the coefficient of thermal expansion is outside of the 40 to 100 percent range, then the anti-breaking strength is lower as compared to a thermistor without a glass layer and as compared to a thermistor with a glass layer made of uncrystallized glass.
It is believed that the increased anti-breaking strength in thermistor 10 is due to compression stresses remaining in insulating glass layer 14 that tend to reinforce thermistor 10 against breaking. During baking, thermistor element 13 expands. During cooling, thermistor element 13 contracts an amount greater that the contraction that insulating glass layer 14 would contract by itself. The result is that insulating glass layer 14 is held in compression at environmental temperatures, thus improving the anti-breaking strength of insulating glass layer 14. This increased strength is attained in a manner similar to prestressed concrete. In prestressed concrete, steel reinforcing bars are held in tension while the concrete sets around them. After the concrete is cured, the tension on the reinforcing bars is released. As a result, the concrete which, like insulating glass layer 14, has poor resistance to tensile stresses, is held in compression, and its breaking strength is greatly increased. In the present application, during cooling of thermistor 10, the higher temperature coefficient of expansion of thermistor element 13 tends to shrink thermistor element 13 more than the free shrinkage of insulating glass layer 14. This applies compressive stress to insulating glass layer 14. Thus, at environmental temperatures, thermistor element 13 prestresses insulating glass layer 14 in a manner analogous to the way that steel reinforcing bars prestress the concrete surrounding them.
In this compressed state, when a bending force is applied to thermistor 10, a compression stress is formed on the inside of the bend and a tensile stress is formed on the outside. Thermistor element 13 and insulating glass layer 14 are both strong against compression stress and weak against tensile stress. Therefore, when a compression prestress is applied to the glass layer, it is harder for a crack to form from the tensile stress on the outside of the bend as compared to thermistors having no glass layer and thermistors with glass layers made of uncrystallized glass.
Referring again to FIG. 2, the present invention limits Ni plating layer 18 and Sn or Sn/Pb plating layer 19 to the surface of baked-on electrode 16. The present invention prevents erosion of thermistor element 13 by the plating fluids and improves adhesion of the plating to thermistor element 13. Therefore, the resistance value of thermistor 10 remains unchanged from its desired value. Ni plating layer 18 increases solder heat resistance. It prevents baked-on electrode layer 16 from corrosion by solder when thermistor 10 is soldered onto a substrate. Sn or Sn/Pb plating layer 19 over Ni plating layer 18 improves solder adhesion of terminal electrodes 12. As stated above, baked-on electrode layer 16 is composed of precious metals. Since Ni plating layer 18 and Sn or Sn/Pb plating layer 19 cover the surface of baked-on electrode layer 16, they inhibit ion movement in the precious metals. This further stabilizes the resistance value of thermistor element 13.
Also, since insulating glass layer 14 is made of crystallized glass, there is little decrease in the viscosity of the glass itself during formation of baked-on electrode layer 16. This prevents insulating glass layer 14 and baked-on electrode layer 16 in the edge area of thermistor element 13 from eroding away. Furthermore, insulating glass layer 14 does not show imprints from sticking or contact with baking tools after formation of baked-on electrode layer 16.
Unlike the prior art, the glass paste does not include inorganic crystals to form insulating glass layer 14. This simplifies printing of the glass paste onto thermistor element 13. Since the crystallizing temperature is reached during formation of insulating glass layers 14 and 14', by passing through the glass transition point, this results in the formation of a fine crystal structure within insulating glass layer 14. Furthermore, since there are no inorganic crystals in the glass paste, the formation of bubbles during the heating process is inhibited. This results in thermistor 10 having a smooth surface.
Referring now to FIG. 4, in a second embodiment of the invention, a thermistor 20 includes an internal resistance regulating electrode 21. Specifically, four internal resistance regulating electrodes 21, two on each end, are placed on the surface of thermistor element 13. Internal resistance regulating electrodes 21 remain outside end surfaces 31 of thermistor element 13. Internal resistance regulating electrodes 21 are electrically connected to respective terminal electrodes 12. Insulating glass layer 14 covers thermistor element 13 as before, including the surface of internal resistance regulating electrode 21. As before, part or all of insulating glass layer 14 is made of crystallized glass.
Referring to FIG. 6(a) a ceramic sintered sheet 11 is prepared according to the method described previously. A conductive paste, which forms a precursor for internal resistance regulating electrodes 21, containing precious metal powder and inorganic binder, is printed in bands, directly above one another, at intervals, on both sides of ceramic sintered sheet 11. The resulting intermediate product is dried and baked at sintering temperature to form ceramic sintered sheet 11, with internal resistance regulating electrodes 21 positioned as shown.
Referring now also to FIG. 6(b), a precursor to insulating glass layer 14 is printed on the both sides of ceramic sintered sheet 11, and covering internal resistance regulating electrodes 21. Ceramic sintered sheet 11 is then baked, forming insulating glass layer 14.
Referring now to FIG. 6(c), strips 35 are formed by cutting ceramic sintered sheet 11 in the direction indicated by arrows perpendicular to internal resistance regulating electrode 21.
Referring now to FIG. 6(d), a glass paste, as described before, is printed and baked on the exposed cut surfaces of thermistor element 13 to form insulating glass layers 14' on both edges of strips 35. Strips 35 baked and cut into chip 15 by finely cutting strips 35 in a direction parallel to internal resistance regulating electrode 21 and along the center line (indicated by arrows) of internal resistance regulating electrode 21.
A conductive paste (not shown) is applied to both cut ends of chip 15. Chip 15 is then baked, forming baked-on electrode layer 16.
Referring to FIG. 4, a Ni plating layer 18 is applied to baked-on electrode layer 16. A Sn/Pb plating layer 19 is plated onto Ni plating layer 18 to complete terminal electrodes 12.
The composition and function of internal resistance regulating electrode 21 is well known in the art, and will not be further described. In addition, the inventive content of the present disclosure is contained elsewhere than in internal resistance regulating electrode 21.
Referring now to FIG. 5, a third embodiment of the present invention is shown. A thermistor 50 has two internal resistance regulating electrodes 21, rather than the four internal resistance regulating electrodes 21 of the embodiment of FIGS. 4 and 6(a)-6(f). Bands of conductive paste are printed on both sides of thermistor element 13, in a manner analogous to the technique shown in FIGS. 6(a)-6(f). However, the bands are offset by one column, resulting in each thermistor 50 having only one internal resistance regulating electrode 21.
Referring to FIG. 7, a fourth embodiment of the present invention is shown. A thermistor 70 includes an internal resistance regulating electrode 22, centered on both sides between the ends of thermistor element 13. Internal resistance regulating electrode 22 does not touch or cover end surfaces 31. Unlike the second and third embodiments, internal resistance regulating electrode 22 does not electrically contact terminal electrodes 12. As described above, insulating glass layer 14, made of at least partially crystallized glass, covers the entire surface of thermistor element 13 including internal resistance regulating electrode 22. However, as stated earlier, insulating glass layer 14 does not cover end surfaces 31.
Thermistor 70 is manufactured as detailed in FIGS. 6(a) through 6(f), except that, in FIG. 6(d), strip 35 is cut in a direction parallel to internal resistance electrode 21 and halfway between two adjacent internal resistance regulating electrodes 21 to form chip 15.
Referring to FIG. 8, a fifth embodiment of the present invention is shown. A thermistor 80 has one internal resistance regulating electrode 22 disposed on the surface of thermistor element 13. The manufacturing of thermistor 80 is similar to that described in the third and fourth embodiments. Similar to the third embodiment, the bands of conductive paste 36 are arranged in an offset relationship. In addition, strip 35 is cut in a manner similar to the fourth embodiment. This results in each thermistor 80 having one internal resistance regulating electrode 22.
Referring to FIG. 9, a sixth embodiment of the present invention is shown. A thermistor 40 includes at least one resistance regulating electrode 23 internal to thermistor element 13. Resistance regulating electrode 23 is in electrical contact with one of terminal electrodes 12. As before, insulating glass layer 14, which is at least partially crystallized glass, covers thermistor element 13 except for end surfaces 31. In a preferred embodiment, a plurality of resistance regulating electrodes 23 (three are shown) are disposed within thermistor element 13. In the embodiment shown, the three resistance regulating electrodes 23 are interleaved, with the first and third (counting from the top in the figure) being connected to the left-hand terminal electrode 12, and the second (center) being connected to the right-hand terminal electrode 12.
A seventh embodiment of the invention includes a thermistor similar to thermistor 40 of FIG. 9, except that its internal resistance regulating electrode 23 is out of electrical contact with terminal electrodes 12.
Thermistor 40 begins as an extremely thin ceramic sheet (not shown). Conductive paste is printed on the top surfaces of a plurality of ceramic sheets and dried, forming first resistance regulating electrodes 23. Then, the plurality of ceramic sheets are stacked. The stack is then baked to form a sintered sheet containing resistance regulating electrodes 23 buried therein. The remaining steps are those described by FIGS. 6(b)-6(f).
By setting the coefficient of thermal expansion of the crystallized glass lower than the coefficient of thermal expansion of the thermistor element by an appropriate margin, a greater compression stress is applied to the insulating glass layer of the thermistor. When a bending force is applied, this thermistor does not crack as easily from the tensile stress on the outside curve of the bend as compared to a thermistor having no insulating glass layer or a thermistor having art insulating glass layer made of uncrystallized glass.
As stated above, by forming an insulating glass layer with crystallized glass, the insulating glass layer does not soften and change shape during formation of the baked-on electrode, nor does the insulating glass layer stick to baking tools, nor does the baked-on electrode layer melt into the insulating glass layer, resulting in a smooth insulating glass layer. Furthermore, the insulating glass layer and the baked-on electrode layer maintain their shapes better, resulting in a more aesthetically pleasing thermistor.
After formation of the baked-on electrode layer, the insulating glass layer prevents the erosion of the thermistor by plating fluids, leaving the resistance unchanged and allowing production of highly reliable thermistors.
By selecting the coefficient of thermal expansion appropriately, the anti-breaking strength of the thermistor is improved over the anti-breaking strength of a thermistor with an insulating glass layer formed from uncrystallized glass.
EXAMPLES
Example 1
A chip-type thermistor according to the first embodiment of the invention was manufactured as follows.
A ceramic sheet was formed from commercially available manganese oxide, cobalt oxide and copper oxide. They were mixed such that their metal elements were in a weight ratio of 40:5:5:5. The mixture was mixed for 16 hours in a ball mill to achieve uniformity, then dehydrated and dried. The mixture was then calcined for two hours at 900 UC. The calcined product was again crushed by a ball mill and dried. A combination of binding materials including 6 weight percent of polyvinyl butyryl, 30 weight percent of ethanol and 30 weight percent butanol were added to the powder and mixed to form a slurry.
The slurry was formed into a film by a doctor blade and dried to form a green sheet 0.80 mm thick. A 70 mm×70 mm sheet was punched from this sheet. The sheet was then baked for 4 hours at 1200 UC, producing a sintered sheet having a vertical length of 50 mm, a horizontal length of 50 mm and a thickness of 0.65 mm.
A glass paste was prepared, by mixing together raw glass powder having as the main components: SiO 2 , ZnO and BaO. The glass transition point of the raw glass powder was approximately 650 UC and the crystallization temperature was approximately 750 UC. The glass components were mixed together uniformly with a binder to form the glass paste. This glass paste was then printed on both sides of the sintered sheet and dried.
After the glass paste has dried, the sintered sheet was heated from room temperature to 850 UC at a rate of approximately 30 UC/minute. This temperature was maintained for approximately 10 minutes and then the sintered sheet was cooled to room temperature at the same rate. The glass paste thus was converted to an insulating glass layer having a thickness of approximately 20 microns.
The sintered sheet was then cut into 1.20 mm wide strips using a 0.10 mm thick diamond blade. The glass paste was then applied to the now exposed cut surfaces to form an insulating glass layer, as described above. As a result, four sides of the strip are covered with an insulating glass layer.
The strip was then finely cut in a direction perpendicular to the previous cut to forming 1.90 mm long chips. An Ag paste was applied to the remaining exposed surfaces and the immediately surrounding insulating glass layer. The chip was then heated from room temperature to 850 UC at a rate of 30 UC/minute. This temperature was maintained for 10 minutes, and then cooled to room temperature at the same rate. This forms the baked-on electrode layer. This baking turns the four surfaces of the insulating glass layer into crystallized glass with a crystallization rate of approximately 60 percent. The resulting chip was approximately 2.0 mm long, approximately 1.25 mm wide, and approximately 0.75 mm thick.
Finally, the baked-on electrode layer was electroplated with a 2-3 micron thick layer of Ni plating and a 4-5 micron thick layer of Sn plating. A two-layer plating layer structure was thus formed on the surface of the baked-on electrode layer. As a result, the chip-type thermistor had a pair of terminal electrodes on the ends thereof composed of a baked-on electrode layer and two plating layers.
The coefficient of thermal expansion of the sintered sheet was measured to be 130×10 -7 /UC and the coefficient of thermal expansion of the crystallized glass, resulting from the baking of the glass paste under the same conditions as noted above, was measured to be 100×10 -7 /UC. This means that the latter coefficient was 77 percent of the former coefficient, falling within the previously stated preferred range.
Comparison Product 1
A glass paste was prepared from a) 80 weight percent of raw glass powder having main components: SiO 2 , PbO and K 2 O, having a softening point of the raw glass was approximately 500 UC and b) 20 weight percent of Zr 2 O powder as inorganic crystals. A chip-type thermistor identical to that of example 1 was formed using the above glass paste. The glass component and the inorganic crystals did not mix uniformly in the paste. Also, under the same baking conditions as in example 1, the glass layer for this thermistor did not crystallize. The coefficient of thermal expansion of this uncrystallized glass was approximately 50×10 -7 /°C. and was thus approximately 38 percent of the coefficient of thermal expansion of the sintered sheet.
Comparing the chip-type thermistors of example 1 and comparative product 1, the following characteristics were examined: the printing quality of the glass paste; the degree to which the shape of the insulating glass layer and the electrode layer was maintained after formation of the baked-on electrode layer; melt adhesion traces on the insulating glass layer; the presence of bubbles in the insulating glass layer; the surface condition of the insulating glass layer; and the anti-breaking strength. The results were tabulated and are presented in Table 1. Excluding the anti-breaking strength, the figures in Table 1 indicate the number of faulty thermistors out of the sample number (20 pieces).
TABLE 1______________________________________sample count = 20Characteristic Embodiment 1 Comparison 1______________________________________Printability 0 Good 20 BadPresence of edge 0 Good 10 Badleaks on glass layerMelting of electrode 0 Good 7 Badlayer into glassPresence of contact 0 Good 12 Badmarks on glass layerBubbles in glass layer 0 Good 12 BadIrregularity of glass 0 Good 15 Badlayer surfaceAnti-breaking strength Avg. = 3.33 kgf Avg. = 2.67 kgf______________________________________
As Table 1 makes clear, the thermistor of embodiment 1, having an insulating glass layer made of crystallized glass, was superior to comparison product 1 having an insulating glass layer made of uncrystallized glass.
Example 2
A chip-type thermistor according to the second embodiment of the invention was manufactured as follows. A sintered sheet, identical to the one in example 1, was produced measuring 50 mm long by 50 mm wide by 0.65 mm thick. Bands of 0.6 mm Ag paste was printed on both sides of ceramic sintered sheet 11 at intervals of 1.4 mm. The bands of Ag paste were dried. The bands were laid out so that they sandwiched the sintered sheet. The sintered sheet was baked at 820 UC, forming a plurality of 10 micron thick electrodes.
A glass paste, identical to the one used in example 1, was printed on both sides of the sintered sheet, and dried. The sintered sheet was baked under the same conditions as example 1, forming a 30 micron thick insulating glass layer on the sheet surface.
The sintered sheet was then cut into 1.20 mm wide strips with a 0.10 mm diamond blade in a direction perpendicular to the bands laid out previously. The glass paste, as in example 1, was applied to the now exposed surfaces to form a insulated glass layer.
The strips were then finely cut to form 1.90 mm long chips. The cuts were made along the center line of the electrode in a direction perpendicular to the previous cuts.
Ag paste was applied to the now exposed surfaces and on the immediately surrounding insulating glass layer. The chip was baked as in example 1, to form a baked-on electrode layer. This baking turns the 4 -sided insulated glass layer into crystallized glass, at a crystallization rate of 60 percent. The resulting chip was approximately 2.0 mm long, approximately 1.3 mm wide, and approximately 0.75 mm thick.
The chip was then electroplated with a 2-3 micron thick Ni plating layer and a 4-5 micron thick Sn plating layer. This formed a two layer plating layer on the surface of the baked-on electrode layer. As a result, the chip-type thermistor had a pair of terminal electrodes having a baked-on electrode layer and two plating layers.
The coefficient of thermal expansion of the sintered sheet before the electrode was formed was measured to be 130×10 -7 /UC and the coefficient of thermal expansion of the crystallized glass resulting from baking the above glass paste was 100×10 -7 /UC, 77 percent of the former.
Comparison Product 2
A chip-type thermistor was made as described in example 2 using the glass paste described in comparison product 1. As before, the glass components and the inorganic crystals did not mix uniformly in the paste. Also, the raw glass did not crystallize under the baking conditions described for example 2, resulting in an uncrystallized insulating glass layer. The coefficient of thermal expansion for this uncrystallized glass was approximately 50×10 -7 /UC, which was approximately 38 percent of the sintered sheet.
Examining the chip-type thermistors of example 2 and of comparative product 2, the following characteristics were studied: the printing quality of the glass paste; the degree to which the shape of the insulating glass layer and the baked-on electrode layer was maintained after formation of the baked-on electrode layer; the melt adhesion traces on the insulating glass layer; the presence of bubbles in the insulating glass layer; the surface condition of the insulating glass layer; and the anti-breaking strength. The results are shown in Table 2. The figures in Table 2 have the same significance as those in Table 1.
TABLE 2______________________________________sample count = 20Characteristic Embodiment 2 Comparison 2______________________________________Printability 0 Good 20 BadPresence of edge 0 Good 9 Badleaks on glass layerMelting of electrode 0 Good 5 Badlayer into glassPresence of contact 0 Good 12 Badmarks on glass layerBubbles in glass layer 0 Good 10 BadIrregularity of glass 0 Good 9 Badlayer surfaceAnti-breaking strength Avg. = 3.01 kgf Avg. = 2.43 kgf______________________________________
As Table 2 makes clear, the thermistor of example 2, having an insulating glass layer of crystallized glass, was superior in all categories to the thermistor of comparative product 2, having an insulating glass layer of uncrystallized glass.
Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.
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An insulating glass layer covers the surface of a thermistor element except at the two end surfaces. The insulating glass layer is partially or fully composed of crystallized glass. A terminal electrode is integrally formed on both end surfaces. The terminal electrodes include a baked-on electrode layer formed from a conductive paste. Layers of nickel and tin or lead/tin are plated onto the baked-on electrode. The insulating glass layer enhances shape-maintainability of the insulating glass layer and the baked-on electrodes, provides a smoother glass surface, resulting in a more aesthetically pleasing thermistor, prevents resistance variance due to plating of the baked-on electrodes and provides a strong anti-breaking strength thermistor. The coefficient of thermal expansion of the glass layer is less than the coefficient of thermal expansion of the thermistor element. This difference in coefficients of thermal expansion tends to help the thermistor element resist stress breakage.
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FIELD OF THE INVENTION
[0001] The present invention relates to a wireless communication terminal having increased usage of internal space.
BACKGROUND ART
[0002] A terminal (or user equipment) may be divided into a mobile/portable terminal and a stationary terminal depending on its mobility. And, a mobile/portable terminal may then be divided into a handheld terminal and a vehicle mount terminal depending on its handheld portability.
[0003] As functions of such terminals have become more diverse, such terminals are being embodied in the form of a Multimedia player, which is equipped with complex functions, such as capturing (or recording) still pictures or videos, playing music or video files, playing games, receiving broadcast, and so on.
[0004] In order to exchange information with other devices, such terminal is equipped with a wireless communication unit. Wireless communication consists of diverse types, such as communication for exchanging information with satellites existing outside the atmosphere, for receiving broadcast information, for using wireless Internet, and so on, short range communication for exchanging information with a neighboring (or adjacent) device, and so on, and such terminal should be diversely equipped with different types of wireless communication antennas with respect to each communication method.
[0005] As the antenna types have become more diverse, difficulty occurs in ensuring space inside the terminal, and, since the antenna is influenced by other electronic devices, the position of the antenna is eventually limited in order to ensure its performance, and, therefore, research on the positioning of antennas inside a terminal is being carried out.
DETAILED DESCRIPTION OF THE INVENTION
Technical Objects
[0006] An object of the present invention is to provide a wireless communication terminal with increased usage of internal space by positioning the heat dissipation structure and the antenna, which are positioned in the wireless communication terminal, to be adjacent to one another, and by having one member perform two or more functions.
Technical Solutions
[0007] In order to achieve the above-described object, the present invention provides a wireless communication terminal including a case having a vent hole formed on one side; an antenna carrier being positioned to have one side face into the vent hole on an inner side of the case and including a duct passing through one side and another side thereof; a fan being positioned on another side of the antenna carrier; and an antenna having an antenna pattern positioned on upper surfaces of the antenna carrier and the fan and transmitting and receiving radio signals.
[0008] The wireless communication terminal further includes a heat sink being positioned between the antenna carrier and the fan and including a plurality of pins being extended from the antenna carrier and toward the fan; and a heat pipe having one end contacting the heat sink and another end contacting a heat-generating assembly part, and the antenna may simultaneously cover the upper surface of the antenna carrier and the upper surface of the heat pipe.
[0009] The antenna pattern may include a radiating part, a feeding part, and a grounding part, and the radiating part may be fixed to the upper surface of the antenna carrier.
[0010] A shape of the upper surface of the antenna carrier may correspond to a shape of the radiating part.
[0011] The heat pipe may be configured of a metallic material, and the grounding part of the antenna pattern may contact the heat pipe.
[0012] The wireless communication terminal may further include a printed circuit board having the fan fixed thereto, and the feeding part may be bent so as to be electrically connected to the printed circuit board.
[0013] A hollow space may be formed toward one end and another end within the heat pipe, and the hollow space may be filled with a refrigerant carrying out phase change from liquid to vapor within a driving temperature range of the wireless communication terminal.
[0014] The antenna may include an adhesive tape having an adherent deposited thereon.
[0015] The case may be configured of a first case having a keypad positioned thereon and a second case having a display positioned thereon, and the vent hole may be formed on one side surface of the first case.
Effects of the Invention
[0016] According to at least one of the exemplary embodiments of the present invention, by positioning the heat dissipation structure and the antenna, which are positioned in the wireless communication terminal, to be adjacent to one another, and by having one member perform two or more functions, a wireless communication terminal demonstrating excellent usage of the internal space may be provided.
[0017] The antenna carrier provides a fixing part, to which the antenna is fixed, on its upper surface, while performing the function of a duct, which acts as a path for the wind being outputted from the fan, and, at the same time, the antenna carrier prevents the wind being outputted from the fan from leaking out of the heat dissipation structure.
[0018] Additionally, the heat pipe not only performs the function of transporting the heat of the heat-generating assembly part to the heat sink but also performs the function of the grounding part of the antenna.
[0019] The effects of the present invention will not be limited only to the effects described above. Accordingly, effects that have not been mentioned above or additional effects of the present application may become apparent to those having ordinary skill in the art from the description presented below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0020] FIG. 1 illustrates a perspective view showing a wireless communication terminal according to an exemplary embodiment of the present invention.
[0021] FIG. 2 illustrates an exploded perspective view showing an antenna, a fan ( 120 ), a heat pipe, a heat sink, and an antenna carrier of the wireless communication terminal according to the exemplary embodiment of the present invention.
[0022] FIG. 3 illustrates a perspective view showing the fan, the heat pipe, the heat sink, and the antenna carrier before attaching the antenna of the wireless communication terminal according to the exemplary embodiment of the present invention.
[0023] FIG. 4 illustrates a perspective view showing a state when the antenna is attached in FIG. 3 .
[0024] FIG. 5 illustrates a cross-sectional view of FIG. 4 .
BEST MODE FOR CARRYING OUT THE PRESENT INVENTION
[0025] The present invention may undergo diverse modifications and may have a plurality of exemplary embodiments, and specific exemplary embodiments will be given as examples in the accompanying drawings and will be described in detail in the detailed description of the present invention. However, it should be understood that the present invention will not be limited only to the specific exemplary embodiments presented herein, and it should also be understood that the scope and spirit of the present invention can be extended to all variations, equivalents, and replacements in addition to the appended drawings of the present invention.
[0026] Terms including numeric expressions, such as first (1st), second (2nd), and so on, used in the specification of the present invention may be used to describe diverse elements of the present invention. However, the elements of the present invention will not be limited by the terms used in the specification of the present invention. In other words, such terms will be used only to differentiate one element from other elements of the present invention.
[0027] When an element is described as “being connected to” or as “accessing” another element, although the corresponding element may be directly connected to or accessing the other element, it should be understood that yet another element may exist between the corresponding element and the other element. Alternatively, when an element is described as “being directly connected to” or as “directly accessing” another element, it should be understood that yet another (or a third) element does not exist between the two elements.
[0028] The terms used in this application are merely used to describe specific exemplary embodiments of the present invention and not intended to limit the present invention. And, unless obviously and clearly noted or specified otherwise within the specification, singular forms of the terms used herein may include plural forms of the corresponding terms.
[0029] In this application, the terms “include(s) (or comprise(s))” or “have/has” are used to designate the presence (or existence) of a characteristic, number, process step, operation, configuration element, assembly part, or a combination of the above, which are mentioned in this specification, and, therefore, it should be understood that the presence (or existence) or possible addition of one or more other characteristics, numbers, process steps, operations, configuration elements, assembly parts, or combinations of the above are not excluded in advance.
[0030] The suffixes “module” and “unit (or part)” that are mentioned in the elements used in the following description are merely used individually or in combination for the purpose of simplifying the description of the present invention. Therefore, the suffix itself will not be used to give a significance or function that differentiates the corresponding terms from one another.
[0031] Hereinafter, the wireless communication terminal ( 100 ) according to the exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings, and, regardless of the reference numerals, the same or corresponding configuration elements will be assigned with the same reference numeral and overlapping description of the same will be omitted for simplicity.
[0032] FIG. 1 illustrates a perspective view showing a wireless communication terminal ( 100 ) according to an exemplary embodiment of the present invention. The wireless communication terminal ( 100 ) according to this exemplary embodiment may be configured of a first case ( 110 ) being equipped with a keypad ( 118 ), and a second case ( 115 ) including a display unit ( 113 ). In case a physical keypad is omitted, and in case of applying a soft keypad for performing touch-type input through the display unit ( 113 ), the wireless communication terminal ( 100 ) may be equipped with only one case ( 110 , 115 ).
[0033] Although the wireless communication terminal ( 100 ) may use one type of communication method, as the demand for terminals using diverse types of communication methods has recently increased, the wireless communication terminal ( 100 ) uses diverse forms of wireless communication methods.
[0034] When categorized in accordance with the wireless communication method, wireless communication may be divided into broadcast communication, mobile communication, wireless Internet, short range communication, position information wireless communication, and so on.
[0035] The broadcast communication method may receive a broadcast signal and/or information associated with broadcasting from an external broadcast management server through a broadcast channel, and the broadcast channel may include satellite channels and groundwave (or terrestrial) channels. In order to perform synchronous (or simultaneous) broadcast reception or broadcast channel switching respective to two broadcast channels, the wireless communication terminal may be equipped with two or more of the broadcast reception antennas.
[0036] The information associated with broadcasting refers to information associated with a broadcast channel, a broadcast program, or a broadcast service provider. The information associated with broadcasting may also be provided through a mobile communication network.
[0037] The information associated with broadcasting may exist in diverse formats. For example, the information may exist in formats of EPG (Electronic Program Guide) of DMB (Digital Multimedia Broadcasting) or ESG (Electronic Service Guide) of DVB-H (Digital Video Broadcast-Handheld), and so on.
[0038] The mobile communication method corresponds to a method of transmitting and receiving radio signals with at least one of a base station and an external terminal server within a mobile communication network, and examples of the mobile communication method may include GSM (globaltransparentem[global system] for Mobile communications), CDMA (Code Division Multiple Access), WCDMA (Wideband CDMA) (the method is not limited only to these), and so on.
[0039] The radio signal may include diverse formats of data in accordance with the transmission and reception of voice call signals, video phone call signals, or text/multimedia messages.
[0040] For the wireless Internet method, WLAN (Wireless LAN) (Wi-Fi), Wibro (Wireless broadband), Wimax (World Interoperability for Microwave Access), HSDPA (High Speed Downlink Packet Access), GSM, CDMA, WCDMA, LTE (Long Term Evolution) (the method is not limited only to these), and so on, may be used.
[0041] Short range communication corresponds to a technology performing communication with a terminal or external wireless device located at a distance within approximately 10 m, and, herein, Bluetooth, RFID (Radio Frequency Identification), IrDA (infrared Data Association), UWB (Ultra Wideband), Zigbee, and so on, may be used for short range communication.
[0042] The position information wireless communication corresponds to a method of performing communication with a satellite in order to acquire the current position information of the wireless communication terminal ( 100 ), and a typical example of this method may correspond to a GPS (Global Positioning System). According to the current technology, the GPS may calculate (or compute) an accurate three-dimensional current position information in accordance with the latitude, longitude, and altitude by calculating information on distances between 3 or more satellites and accurate time information and then by applying trigonometry on the calculated (or computed) information.
[0043] Currently, a method of using three satellites for calculating the position and time information and using another satellite for correcting differences in the calculated position and time information is widely used. Additionally, by continuously calculating the current position in real-time, the GPS module ( 115 ) may calculate speed information.
[0044] As described above, in order to use the diverse wireless communication methods, each of the antennas shall be equipped, and since the antenna transmits and receives radio signals, and since this may influence neighboring antennas, the antennas are required to be spaced apart from one another to a predetermined distance.
[0045] Additionally, since interference may be caused with a signal of another electronic device, the position of the antennas shall be considered in accordance with other assembly parts. For such reasons, the antenna is generally positioned (or located) on an end portion or corner of the wireless communication terminal ( 100 ).
[0046] In this exemplary embodiment, when the antenna is positioned on a rear-side corner of the second case ( 115 ), by partially sharing an assembly part with the heat dissipation structure, which is positioned to be adjacent to the antenna, the utilization of space has been increased.
[0047] Since the electronic assembly parts inside the case ( 110 , 115 ) generate heat when operated, the wind generated from the fan ( 120 ) absorbs the heat generated from the inside of the case ( 110 , 115 ) and discharges it to the outside. The wind that has absorbed the heat is discharged to the outside through the vent hole ( 115 ), which is formed in the case ( 110 , 115 ). The vent hole ( 115 ) may generally be positioned to the rear side of the first case ( 110 ) so as to prevent the wind from directly reaching the user.
[0048] At this point, since there lies a problem in that the heat dissipation structure may be positioned in the same location as the above-described antenna, an object of the present invention is to position the antenna and the heat dissipation structure with more spatial efficiency.
[0049] FIG. 2 illustrates an exploded perspective view showing an antenna ( 160 ), a fan ( 120 ), a heat pipe ( 130 ), a heat sink ( 140 ), and an antenna carrier ( 150 ) of the wireless communication terminal ( 100 ) according to the exemplary embodiment of the present invention. The heat dissipation structure of the present invention may basically include a fan ( 120 ) and may then include a heat pipe ( 130 ) and a heat sink ( 140 ). The fan ( 120 ) generates wind with its turning force so that the heat within the case ( 110 , 115 ) can be discharged to the outside through the vent hole ( 115 ). At this point, since the wind that is generated from the fan ( 120 ) cannot reach all of the parts within the case ( 110 , 115 ), a heat pipe ( 130 ) may be used in order to absorb heat from an assembly part generating a large amount of heat when driven (or operated) (hereinafter referred to as a ‘heat generating assembly part ( 190 )’) and to transport (or deliver) the absorbed heat toward the fan ( 120 ).
[0050] The heat pipe ( 130 ) is manufactured by using a metallic material having high thermal conductivity, and one end of the heat pipe ( 130 ) is positioned at an entrance (or opening) through which the wind from the fan ( 120 ) is discharged, and another end of the heat pipe ( 130 ) is contacted to the heat-generating assembly part ( 190 ). The heat absorbed from the heat-generating assembly part ( 190 ), which is contacting the other end, is transported toward the direction of the one end.
[0051] As shown in FIG. 2 , the heat pipe ( 130 ) includes a hollow space in its inside, and the heat pipe ( 130 ) is extended significantly to one direction. The hollow space inside the heat pipe ( 130 ) is filled with a refrigerant, which causes a phase change from liquid to vapor within the driving temperature range of the wireless communication terminal ( 100 ).
[0052] More specifically, when the heat-generating assembly part ( 190 ) is operated (or driven), and when heat is generated accordingly, the refrigerant that is positioned at the other end portion of the heat pipe ( 130 ) is vaporized, and, after moving toward the direction of the one end of the heat pipe ( 130 ), the vaporized refrigerant carries out heat exchange due to the wind generated from the fan ( 120 ), and, then, the refrigerant undergoes a phase change to a liquid form.
[0053] In order to allow the heat transported through the heat pipe ( 130 ) to efficiently carry out heat exchange with the wind generated from the fan ( 120 ), a heat sink ( 140 ) increasing the contacting surface between the heat and the wind generated from the fan ( 120 ) is further included. The heat sink ( 140 ) contacts one end of the heat pipe ( 130 ) and includes a plurality of pins formed along the direction of the wind, which is generated from the fan ( 120 ). Heat exchange is carried out by the pins, and, accordingly, the temperature of the refrigerant in the heat pipe ( 130 ) is decreased.
[0054] FIG. 3 illustrates a perspective view showing the fan ( 120 ), the heat pipe ( 130 ), the heat sink ( 140 ), and the antenna carrier ( 150 ) before attaching the antenna ( 160 ) of the wireless communication terminal ( 100 ) according to the exemplary embodiment of the present invention. As shown in FIG. 3 , the heat sink ( 140 ) is located at an exit through which the wind generated from the fan ( 120 ) flows out, and the heat pipe ( 130 ) is fixed to an upper surface of the heat sink ( 140 ).
[0055] In order to allow the antenna ( 160 ) to be fixed to its upper surface, the antenna carrier ( 150 ) has an upper surface having a shape that corresponds to the shape of the antenna ( 160 ), and, in order to prevent any influence to be caused on the performance of the antenna ( 160 ), the antenna carrier ( 150 ) is formed of a non-conductive substance, such as resin.
[0056] The antenna carrier ( 150 ) is positioned to be adjacent to the vent hole ( 115 ) and is located at a position where the wind from the heat sink ( 140 ) is discharged, and a lower portion of the antenna carrier ( 150 ) forms a space, which is used as a duct ( 151 ) connecting the heat sink ( 140 ) and the vent hole ( 115 ). More specifically, the upper portion of the antenna carrier ( 150 ) may be used as a fixing part to which the antenna is fixed, and the lower portion may be used as a duct ( 151 ) for allowing the heat to the discharged.
[0057] The antenna ( 160 ), which is located on the upper surface of the antenna carrier ( 150 ), may be realized by forming an antenna pattern ( 161 ) using a metallic substance on an upper surface of a film formed of resin, and the antenna pattern ( 161 ) includes a radiating part ( 162 ), a feeding part ( 163 ), and a grounding part ( 164 ). The radiating part ( 162 ) transmits and receives signals of a frequency respective to the standard of the corresponding antenna and is formed of a conductive material. The length of the radiating part ( 162 ) may be decided in accordance with the frequency of the signal that is being transmitted and received, and its mounting space may be reduced due to the antenna pattern ( 161 ) having a shape that is bent several times.
[0058] Both ends of the radiating part ( 162 ) are respectively connected to the feeding part ( 163 ) and the grounding part ( 164 ). The feeding part ( 163 ) is connected to a controller and is supplied with power from the controller, and, then, electric current flows along a loop, which connects the feeding part ( 163 ), the radiating part ( 162 ), and the grounding part ( 164 ). As the electric current flows along the loop, an electromagnetic field is formed, thereby allowing the signal to be transmitted and received.
[0059] FIG. 4 illustrates a perspective view showing a state when the antenna ( 160 ) is attached in FIG. 3 , and FIG. 5 illustrates a cross-sectional view of FIG. 4 . A portion of the radiating part ( 162 ) of the antenna is located on the upper surface of the antenna carrier ( 150 ), the grounding part ( 164 ) is located on an upper surface of the heat pipe ( 130 ), and the feeding part ( 163 ) contacts a printed circuit board, which is bent and located on a bottom surface.
[0060] Since the radiating part ( 162 ) should not come in contact with a metallic object, the radiating part ( 162 ) is located on the upper surface of the antenna carrier ( 150 ), which is formed of a non-metallic substance. The shape of the antenna carrier ( 150 ) corresponds to the shape of the antenna pattern ( 161 ), and, since a portion of the radiating part ( 162 ) is fixed to the upper surface of the antenna carrier ( 150 ), the shape of the antenna carrier ( 150 ) is formed in a shape corresponding to the portion of the radiating part ( 162 ).
[0061] Meanwhile, the feeding unit ( 163 ) is connected to the printed circuit board in order to be supplied with power, and the grounding part ( 164 ) comes in contact with metal in order to be grounded. In order to establish the connection between the feeding part ( 163 ) and the printed circuit board, the antenna is partially bent (see FIG. 2 ), thereby allowing the feeding part ( 163 ) of the antenna pattern ( 161 ) to be combined with the printed circuit board. The grounding part ( 164 ) may be grounded by contacting a heat pipe ( 130 ), which is formed of a metallic substance, and the heat pipe ( 130 ) not only performs a function of transporting (or delivering) the heat of the heat-generating assembly part ( 190 ) but also performs a function of the grounding part ( 164 ).
[0062] The antenna ( 160 ) covers the upper portion of the antenna carrier ( 150 ) and a portion of the upper surface of the heat pipe ( 130 ). By using a tape ( 165 ) including an adherent on a lower surface of the film, the antenna ( 160 ) may be combined with the antenna carrier ( 150 ) and the upper surface of the heat pipe ( 13 [ 130 ]).
[0063] At this point, the antenna ( 160 ) covers the heat pipe ( 130 ) and the upper surface between the heat sink ( 140 ) (or the heat pipe ( 130 )) and the antenna carrier ( 150 ), thereby minimizing leakage of the wind through the antenna carrier ( 150 ) and the heat sink ( 140 ).
[0064] As described above, the antenna carrier ( 150 ) provides a fixing part, to which the antenna ( 160 ) is fixed, on its upper surface, while performing the function of a duct ( 151 ), which acts as a path for the wind being outputted from the fan ( 120 ), and, at the same time, the antenna carrier ( 150 ) prevents the wind being outputted from the fan ( 120 ) from leaking out of the heat dissipation structure.
[0065] Additionally, the heat pipe ( 130 ) not only performs the function of transporting the heat of the heat-generating assembly part ( 190 ) to the heat sink ( 140 ) but also performs the function of the grounding part ( 164 ) of the antenna. More specifically, the wireless communication terminal ( 100 ) according to the present invention positions the heat dissipation structure and the antenna so that they are adjacent to one another, and by having one member perform two or more functions, the utilization (or usage) of the internal space may be increased.
[0066] It will be apparent to anyone skilled in that art that the present invention may be realized in another concrete configuration (or formation) without deviating from the spiritual and essential characteristics of the present invention.
[0067] Therefore, in all aspect, the detailed description of present invention is intended to be understood and interpreted as an exemplary embodiment of the present invention without limitation. The scope of the present invention shall be decided based upon a reasonable interpretation of the appended claims of the present invention and shall come within the scope of the appended claims and their equivalents.
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To achieve the above objectives, a wireless communication terminal of the present invention comprises: a case having a bent hole formed in one side thereof; an antenna carrier disposed in the case such that a side thereof faces the bent hole, and including a duct passing through one side and the other side thereof; a fan disposed on the other side of the antenna carrier; and an antenna disposed on the antenna carrier and the top surface of the fan and having an antenna pattern for transmitting and receiving wireless signals, wherein the wireless communication terminal has the antenna and a heat dissipating structure disposed in proximity such that one member performs two or more functions, so as to provide a wireless communication terminal making good use of internal space.
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CROSS-REFERENCE TO RELATED PATENT APPLICATION
[0001] This patent application claims the benefit of German application No. 10 2014 111 641.0, filed Aug. 14, 2014, the teachings and disclosure of which are hereby incorporated in their entirety by reference thereto.
BACKGROUND OF THE INVENTION
[0002] The invention relates to a hand-actuated transmitter unit for vehicles, in particular for handlebar-controlled vehicles, comprising a housing, a master cylinder provided in the housing, an actuating lever which is movable relative to the housing and a plunger which transmits a movement of the actuating lever to the master cylinder and which is mounted on the actuating lever.
[0003] Hand-actuated transmitter units of this type are known from the prior art.
[0004] It is an object of the invention to configure a transmitter unit of this type to be as economical and functional as possible.
SUMMARY OF THE INVENTION
[0005] This object is achieved according to the invention with a transmitter unit of the aforementioned type in that provided on the housing is a reach adjust device for the actuating lever, with which a respective starting position of the actuating lever is pre-settable.
[0006] The advantage of the solution according to the invention is to be found therein that, by means of such a reach adjustment, the current user of the hand-actuated master cylinder device can set the starting position of the actuating lever relative to the handlebar that is favourable for him, in particular a starting position that is favourable for a hand of the user.
[0007] Preferably, such a reach adjust device is configured so that it comprises an adjustment element which is movable relative to the housing and with which the respective starting position is settable. The adjustment element can be arranged or mounted on the housing to be movable in highly varied ways.
[0008] For example, it is conceivable to mount the adjustment element rotatable on the housing, so that by rotating the adjustment element, different starting positions of the actuating lever are pre-settable.
[0009] A solution that is advantageous with regard to the design and particularly the space requirement provides that the adjustment element is displaceably arranged on the housing.
[0010] Such a displaceable arrangement of the adjustment element relative to the housing has the advantage that with this arrangement, the space requirement for the reach adjust unit can be kept small.
[0011] A particularly favourable solution provides that the adjustment element can be brought into different positions relative to the pivot axis of the actuating lever, having different spacings from the pivot axis, defining the different starting positions which themselves correspond to different reaches.
[0012] With regard to the configuration of the adjustment element itself, no detailed indications have so far been given.
[0013] In particular, no detailed indications have been given regarding the cooperation of the adjustment element with the actuating lever for setting the different starting positions.
[0014] Thus, an advantageous solution provides that the adjustment element has at least one stop surface for a contact arm of the actuating lever.
[0015] In this regard, the at least one stop surface could be configured so that it is a surface that is continuously varying and particularly therefore providing different angular spacings of the actuating lever from a holding unit, on which surface the contact arm lies for setting the different starting positions on different surface regions.
[0016] A particularly advantageous embodiment provides that the adjustment element has different stop surfaces which particularly set different angular spacings of the actuating lever from a holding unit and which are associated with different starting positions of the actuating lever.
[0017] For example, such different stop surfaces can be configured as surfaces or surface regions offset relative to one another with which the contact arm cooperates in each starting position.
[0018] In this case, it is suitably provided that by means of the movement of the adjustment element, one of the respective stop surfaces can be brought into an active position cooperating with the contact arm in which a setting of the respective starting position of the actuating lever takes place.
[0019] With regard to the definition of the different positions of the adjustment element for reaching the different starting positions of the actuating lever, no detailed indications have been given in the context of the description above of the individual exemplary embodiments.
[0020] For example, it is conceivable to provide a self-locking adjusting device.
[0021] Another possibility is to fix the adjustment element in different positions, for example, with a screw.
[0022] A particularly favourable solution provides that the adjustment element of the reach adjust device is fixable in the different positions by means of a locking device.
[0023] The advantage of this solution lies therein that a tool-free reach adjustment is possible particularly easily since the locking device can be configured so that it permits the achievement of the different positions tool-free and thus purely manually.
[0024] In particular it is herein provided that the locking device comprises two cooperating locking elements of which one is connected to the housing and another to the adjustment element, so that thereby the adjustment element can be fixed relative to the housing in the different positions in a particularly simple manner.
[0025] The locking elements can be configured in widely varying ways.
[0026] An advantageous solution provides that a first locking element has a projection and that a second locking element has different locking surfaces for fixing the different positions of the adjustment element.
[0027] In this configuration of the locking elements, the projection preferably cooperates with one of the respective locking surfaces to fix the relevant position and, in order to achieve different positions, the projection is moved to the different locking surfaces.
[0028] With regard to the execution of the locking movement, no detailed indications have been given in the context of the configuration of the locking elements.
[0029] Thus, it is suitably provided that one of the locking elements comprises a resilient tongue which enables the locking elements to move relative to one another from one locking position into another locking position.
[0030] Preferably, in the solution according to the invention, the second locking element is connected to the adjustment element and the first locking element is connected to the housing.
[0031] It is suitably further provided that the second locking element comprises the resilient tongue which carries the plurality of locking surfaces.
[0032] Furthermore, no detailed indications have been given in the context of the above solution also concerning the arrangement of the adjustment element on the housing.
[0033] Thus, an advantageous solution provides that the adjustment element is guided by means of a guide on the housing and is thus movable in a defined manner in a guide direction relative to the housing.
[0034] For example the guide is configured so that it comprises on one hand guide bodies and on the other hand guide grooves wherein the guide direction is pre-defined by the guide grooves.
[0035] For example, it is provided that the adjustment element, the guide bodies and the guide grooves are arranged on the housing.
[0036] With regard to the guide direction for the movability of the adjustment element, no detailed indications have so far been given.
[0037] Thus a particularly compactly designed solution provides that the adjustment element is movable through the guide in a guide direction approximately parallel to the master cylinder, so that the housing can be formed small and compact.
[0038] Approximately parallel should be understood herein to mean that the deviation of the guide direction from a parallel course is 20° or less.
[0039] Alternatively or in addition to the previously described features, the object described in the introduction is achieved according to the invention with a transmitter unit of the type described in the introduction in that the plunger is adjustable relative to the actuating lever by means of a threaded guide, in that the threaded guide comprises an external thread provided on the plunger, said thread engaging in an internal thread arranged statically on the pressure arm of the actuating lever, in that the plunger comprises a rotary control element and in that, arranged on the actuating lever is a first locking element which cooperates with a second locking element provided on the plunger and defines individual rotary positions of the plunger.
[0040] The advantage of this solution according to the invention is that a solution is thereby achieved which is particularly easy to realise and is reliable with regard to functional safety.
[0041] It is herein particularly favourable if the second locking element is connected to the rotary control element so that the second locking element is also rotatable by means of the rotary control element.
[0042] A still simpler and advantageous solution provides that the second locking element is formed onto the rotary control element.
[0043] A particularly advantageous solution provides that the second locking element is formed by the rotary control element itself.
[0044] This solution is particularly advantageous since it does not require a separate part as the second locking element, but rather the second locking element can be formed by the rotary control element itself, for example, by means of grip recesses of the control element itself, so that a solution is provided that is both economical and space-saving.
[0045] With regard to the configuration of the first locking element, no detailed indications have so far been given.
[0046] An advantageous solution provides that the first locking element comprises a locking nose.
[0047] The locking nose could be arranged, for example, statically on the actuating lever and the second locking element for example could be formed with the necessary flexibility so that it can deform in order to enable different locking positions of the first locking element relative to the second locking element.
[0048] A particularly favourable solution provides that the first locking element comprises a resilient tongue which carries the locking nose.
[0049] With a resilient tongue of this type, the possibility exists of realising the resilient movement for the locking of the first locking element and the second locking element in different positions by means of the first locking element.
[0050] For example, herein the resilient tongue could be configured as desired relative to the actuating lever.
[0051] If, for example the actuating lever is made of metal, it is provided that the resilient tongue is held on the actuating lever, for example, by clamping, riveting or screw fastening.
[0052] A particularly favourable solution provides that the first locking element is formed integrally onto the actuating lever.
[0053] In the case of an actuating lever made of any desired materials, this is easily realised if the first locking element is not to carry out any resilient movement relative to the second locking element.
[0054] In the case of a first locking element which is to carry out a resilient movement, it is suitably provided in this case that the actuating lever is made of a material which permits the configuration of the resiliently movable locking element.
[0055] This is the case, for example, if the actuating lever is made of plastics.
[0056] Furthermore, it is suitably provided, for the configuration of the first locking element so that it can carry out a resilient movement relative to the actuating lever, that the first locking element is movable into a recess of the actuating lever in order, for example, to be able to carry out a resilient diversion during the transition between different locking positions of the second locking element.
[0057] This solution can also be realised in a particularly easy and space-saving manner if the actuating element is made of plastics.
[0058] With regard to the exemplary embodiments described so far, no details have been given concerning how the actuating lever should be held in each starting position.
[0059] In this regard, it is particularly advantageous if the actuating lever is spring-loaded in the direction of the respective starting position and is thereby held in said position in the non-actuated state, which means that, in the non-actuated state, the actuating lever always transfers automatically into the starting position.
[0060] For this purpose, a separate spring unit which moves the actuating lever independently into the respective starting position can be provided.
[0061] However, a particularly advantageous solution provides that the actuating lever is acted upon by the master cylinder in the direction of the starting position and thus the master cylinder acts upon the actuating lever such that the actuating lever assumes the respective starting position.
[0062] This solution has the further advantage that thereby the respective starting position of the actuating lever simultaneously represents a starting position for the master cylinder.
[0063] Thus the starting position of the actuating lever is always associated with a corresponding starting position of the master cylinder.
[0064] However, this starting position of the master cylinder can also be set by means of the adjustability of the plunger.
[0065] In particular, such an influence of the master cylinder on the actuating lever can be realised in that the master cylinder is provided with a resilient element which acts constantly upon the master cylinder in its direction guiding the actuating lever into the starting position.
[0066] Further features and advantages of the invention are the subject matter of the following description and of the illustration in the drawings of some exemplary embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0067] FIG. 1 shows a plan view of a transmitter unit mounted on a portion of a handlebar;
[0068] FIG. 2 shows a longitudinal section through the transmitter unit in FIG. 1 in a sectional plane parallel to the drawing plane in FIG. 1 ;
[0069] FIG. 3 shows a perspective view of a pressure arm of the actuating lever in the direction of the arrow A in FIG. 1 ;
[0070] FIG. 4 shows an enlarged longitudinal section through the actuating lever in the region of the pressure arm, but without the plunger;
[0071] FIG. 5 shows a section similar to FIG. 4 with the plunger;
[0072] FIG. 6 shows a section along the line 6 - 6 in FIG. 5 ;
[0073] FIG. 7 shows an enlarged longitudinal section similar to FIG. 2 through a housing of the transmitter unit together with part of the actuating lever and a plunger provided thereon and a reach adjust device in a position corresponding to a maximum reach;
[0074] FIG. 8 shows a section according to FIG. 7 with the reach adjust device in a position corresponding to a relatively small reach;
[0075] FIG. 9 shows a representation according to FIG. 7 with the reach adjust device in a position corresponding to a minimum reach;
[0076] FIG. 10 shows a section similar to FIG. 2 in a position of the reach adjust device corresponding to a middle position according to FIG. 8 ;
[0077] FIG. 11 shows a section similar to FIG. 2 in a position of the reach adjust device with a minimum reach according to FIG. 9 ;
[0078] FIG. 12 shows an enlarged partial representation of the reach adjust device according to the position at maximum reach according to FIG. 7 ;
[0079] FIG. 13 shows an enlarged representation of the reach adjust device in a position corresponding to the middle reach according to FIG. 8 ;
[0080] FIG. 14 shows an enlarged representation of the reach adjust device in a position corresponding to the minimum reach according to FIG. 9 ;
[0081] FIG. 15 shows a section along the line 15 - 15 in FIG. 1 ;
DETAILED DESCRIPTION OF THE INVENTION
[0082] An exemplary embodiment of a transmitter unit 10 according to the invention, as shown in FIG. 1 , for vehicles, particularly handlebar-controlled vehicles, comprises a housing 14 mountable on a handlebar 12 of the vehicle, said housing having a holding unit 16 which is clampingly fixable on the handlebar 12 .
[0083] The housing 14 further comprises a housing body 18 on which an actuating lever 22 is mounted pivotable about a pivot axis 24 , wherein the actuating lever 22 has a manually actuatable handle arm 26 with a handle surface 28 for manual actuation of the actuating lever 22 , wherein a manual pressure on the handle surface 28 leads to pivoting of the actuating lever 22 in an actuating direction 32 about the pivot axis 24 starting from a starting position.
[0084] As FIGS. 1 and 2 show, as well as the handle arm 26 , the actuating lever 22 also comprises a pressure arm 36 on which a plunger identified altogether as 42 is mounted.
[0085] A master cylinder 44 which is mounted in the housing body 18 is actuable by the plunger 42 .
[0086] The master cylinder 44 is preferably formed by a cylinder housing 46 arranged, in particular integrally, in the housing body 18 , in which cylinder housing a piston 48 is arranged movable in a movement direction 52 , wherein the cylinder housing 46 and the piston 48 delimit a cylinder chamber 54 the volume of which varies depending on the position of the piston 48 so that in the event that a hydraulic medium is provided in the cylinder chamber 54 , the master cylinder 44 operates as a hydraulic master cylinder by which the hydraulic medium can be fed via a hydraulic line 55 to a slave unit, for example, for actuating a brake unit.
[0087] In order to move the piston 48 in the movement direction 52 , it is provided with a pressing surface 56 on which the plunger 42 acts with a plunger head 58 .
[0088] Furthermore, the piston 48 is acted upon in the direction of an end position defining a maximum volume of the cylinder chamber 54 by a compression spring 62 arranged in the cylinder chamber 54 which therefore constantly displaces the piston 48 toward an enlargement of the cylinder chamber 54 , so that the piston preferably acts constantly with the pressure surface 56 against a rounded plunger head surface 64 of the plunger head 58 and constantly pivots the actuating lever 22 until a contact arm 66 abuts a reach adjust device 72 which is also provided in the housing 14 and which defines the starting position of the actuating lever 22 .
[0089] As shown in FIGS. 3 to 5 , provided in the pressure arm 36 itself is an internal thread 82 in which an external thread 84 of the plunger 42 engages so that the internal thread 82 of the pressure arm 36 and the external thread 84 of the plunger 42 together form a threaded guide 86 by means of which the plunger 42 is rotatable and displaceable in the direction of a longitudinal axis 88 thereof which is simultaneously the central axis of the threaded guide 86 , in order to be able to set the spacing of the plunger head 58 from the pressure arm 36 .
[0090] In order to turn the plunger 42 , it is provided at its end remote from the plunger head 58 with a rotary control element 92 which is held non-rotatably on an end portion 94 of the plunger 42 opposite to the plunger head 58 .
[0091] The threaded guide 86 and the pressure arm 36 thus lie between the plunger head 58 and the rotary control element 92 .
[0092] The rotary control element 92 is herein provided peripherally, as shown in FIGS. 5 and 6 , with grip recesses 96 which lie respectively between raised portions 98 of the rotary control element 92 .
[0093] Due to the arrangement of the internal thread 82 of the threaded guide 86 directly in the pressure arm 36 , the orientation of the longitudinal axis 88 of the plunger 42 relative to the actuating lever 22 is also pre-determined, so that the plunger 42 is always oriented in a defined manner relative to the actuating lever 22 and particularly also to the handle arm 26 .
[0094] For this reason, the plunger head 58 is preferably provided with the rounded head surface 64 which acts on the pressing surface 56 of the piston 48 .
[0095] In order to prevent the free rotatability of the plunger 42 in the threaded guide 86 , a locking element 102 is preferably provided which has a locking nose 104 which can be brought into engagement with the grip recesses 96 of the rotary control element 92 in order thereby to fix the rotary control element 92 in a rotary position.
[0096] The locking nose 104 is herein preferably mounted on a tongue 106 which is elastically movable relative to the actuating lever 22 , particularly relative to the handle arm 26 of the actuating lever 22 .
[0097] In the exemplary embodiment shown, the actuating lever 22 is provided in the region of the handle arm 26 with a recess 116 lying between side cheeks 112 and 114 of the handle arm 26 , and extending as far as the tongue 106 with the locking nose 104 , wherein a U-shaped slit 118 which extends round the tongue 106 and the locking nose 104 is provided which frees the tongue 106 with the locking nose 104 , so that consequently the tongue 106 is connected on one side only by a tongue root 122 to the handle arm 26 ( FIG. 3 ) and thus can move resiliently in a springing direction 124 in the recess 116 , particularly thereinto.
[0098] This design enables the tongue 106 with the locking nose 104 to be configured as one part integrally with the handle arm 26 if the actuating lever 22 is manufactured, for example, with the handle arm 26 as a plastics part.
[0099] If, however, the actuating lever 22 is configured with the handle arm 26 as a metal part, the tongue 106 bearing the locking nose 104 is to be configured as a resilient element and is to be connected to the actuating lever 22 , in particular the handle arm 26 .
[0100] By means of the locking of the rotary control element 92 in the different positions, a setting of the plunger 42 once pre-determined by means of the threaded guide 86 and thus the position of the piston 48 pre-determined by the plunger 42 in the starting position of the actuating lever 22 pre-determined by the reach adjust device 72 can thus be maintained without any change in the position of the plunger 42 taking place independently.
[0101] In this way, in particular, adaptations of the master cylinder 44 to slave-side changes, for example, changes of brake linings through wear can be carried out.
[0102] As mentioned above, with the transmitter unit 10 according to the invention, by means of the reach adjust device 72 in cooperation with the contact arm 66 , the starting position of the actuating lever 22 and thus a reach, that is, the spacing of the handle arm 26 from the handlebar 12 can also be set.
[0103] For this purpose, as shown in FIGS. 7 to 9 , arranged in the housing body 18 an adjustment element 132 is provided which is movable relative thereto and which, as shown enlarged in FIGS. 12 to 15 , has altogether three stop surfaces 134 , 136 , 138 , each of which can be brought by means of a movement of the adjustment element 132 , for example, by means of linear displacement thereof in a displacement direction 142 into an active position in which said stop surfaces delimit a pivoting of the actuating lever 22 contrary to the actuating direction 32 in that the contact arm 66 comes to rest on the respective stop surface 134 , 136 , 138 which is in the active position, wherein by this means a fixing of the respective starting position of the actuating lever 22 takes place.
[0104] As shown in FIG. 7 and FIG. 2 , a first stop surface 134 is provided for a maximum reach, that is, a maximum spacing of the handle arm 26 from the handlebar 12 and the contact arm 66 can be placed on said stop surface when the adjustment element 132 is situated in a first position in which it has a maximum spacing from the pivot axis 24 , so that the contact arm 66 abuts on the first stop surface 134 lying closest to the pivot axis 24 .
[0105] This first stop surface 134 is arranged so that it permits a starting position of the handle arm 26 which, relative to the pivot axis 24 , represents a maximum angular spacing W 1 from the holding unit 14 , as FIG. 2 shows.
[0106] The second stop surface 136 is effective when the adjustment element 132 is displaced, starting from the first position shown in FIGS. 7 and 2 , into a second position shown in FIGS. 8 and 10 and lying closer to the pivot axis 24 , so that the contact arm 66 abuts against this second stop surface 136 , wherein this second stop surface is arranged so that when the contact arm 66 abuts thereon, the handle arm 26 has an angular spacing W 2 from the holding unit 16 which is smaller than the angular spacing W 1 .
[0107] In order to move the third stop surface 138 into its active position, the adjustment element 132 is to be displaced in the direction of the pivot axis 24 far enough so that the adjustment element assumes the position closest to the pivot axis 24 .
[0108] The third stop surface 138 is herein arranged so that the angular spacing W 3 between the handle arm 26 and the holding unit 16 is smaller than the angular spacing W 2 ( FIGS. 9 and 11 ).
[0109] In order to be able to position the adjustment element 132 reliably in the different positions corresponding to the different angular spacings W 1 , W 2 , W 3 in which the different stop surfaces 134 , 136 and 138 are effective, the adjustment element 132 is lockable relative to the housing body 18 with a locking device identified overall as 152 , as shown in FIGS. 12 to 16 .
[0110] The locking device 152 herein comprises a first locking element 154 which is connected, for example, to the housing body 18 and can be configured as a cam or a pin, and comprises a second locking element 156 which has a plurality of locking surfaces 162 , 164 and 166 with which the first locking element 154 can cooperate in order to fix the adjustment element 132 in the different positions corresponding, for example, to the angular spacings W 1 or W 2 or W 3 relative to the housing body 18 .
[0111] Preferably, the second locking element 156 is configured as a resilient tongue 168 formed onto the adjustment element 132 .
[0112] In order to guide the adjustment element 132 in the housing body, as shown in FIGS. 15 and 16 , provided lying laterally on the adjustment element 132 are guide bodies 172 and 174 which engage in corresponding guide grooves 176 and 178 of the housing body 18 and thus guide the adjustment element 132 displaceably in the displacement direction 142 between the different positions fixable by the locking device 152 .
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In order to configure a hand-actuated transmitter unit for vehicles, in particular for handlebar-controlled vehicles, comprising a housing, a master cylinder provided in the housing, an actuating lever which is movable relative to the housing and a plunger which transmits a movement of the actuating lever to the master cylinder and which is mounted on the actuating lever, to be as economical and functional as possible, it is proposed that provided on the housing is a reach adjust device for the actuating lever, with which a respective starting position of the actuating lever is pre-settable.
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This invention relates to cooling apparatus, particularly of the kind in which a liquefied gas or its cold vapour is introduced into a chamber to perform a cooling duty and cold spent gas is exhausted from the chamber.
BACKGROUND OF THE INVENTION
Such cooling apparatus is widely used in industry, for example in the freezing of food. A liquefied gas, typically liquid nitrogen, may be used to cool food in a tumbler or screw conveyor, or may be used to freeze food in a tunnel or a so-called immersion freezer. In the example of a freezing tunnel, food is advanced on a conveyor through a chamber in the form of a tunnel into which liquid nitrogen is injected. Typically, the liquid nitrogen is directed at the food and extracts heat therefrom as it vaporises. A fan or fans are employed to provide a flow of cold nitrogen vapour through the tunnel in a direction opposite to that in which the food is advanced through the tunnel. This flow of cold nitrogen vapour is also able to extract heat from the food. In order to limit the amount of cold nitrogen vapour that spills out of the ends of the tunnel, a fan is employed to extract the cold nitrogen vapour from a position in the tunnel between its ends. The fan typically communicates with an outlet in the roof of the tunnel. Since liquid nitrogen vaporises at a temperature of - 196° C., the temperature of the vapour extracted from the tunnel is well below freezing point even though there has been heat exchange between the vapour and the food (or other articles or material being advanced through the tunnel) and dilution of the nitrogen vapour with air takes place in the tunnel.
The operation of the exhaust fan induces a flow of air into the tunnel. Measures need to be taken to prevent the cold exhaust gas from causing ice to be deposited on the fan. Otherwise, there is a risk that either damage is caused to the fan, in operation, by the ice or that there will be a sufficient accumulation of ice to prevent its operation.
The solution normally adopted to this problem is to provide the ducting by which the fan is placed in communication with the outlet from the tunnel with an adjustable inlet for ambient air. Typically, this inlet is designed so as to enable the fan to draw in a flow of ambient air into the ducting at a rate three or four times that at which the mixture of cold nitrogen vapour and air enters the ducting from the outlet of the freezing tunnel.
There are a number of disadvantages associated with such exhaust gas extraction systems. In particular, the extraction duct needs to be of greater diameter than it would otherwise have to be in order to cope with the induced air flow. Moreover, the refrigerative capacity of the extracted nitrogen vapour is wasted. In addition, if the ambient air has been conditioned, a common practice in food processing factories, extracting air with the nitrogen vapour effectively reduces the overall efficiency of the air conditioning system. A further disadvantage is that practical problems arise with the control of the extraction system. The operation of the exhaust fan is typically linked to a valve controlling the flow of liquid nitrogen into the tunnel. Since the tunnel may be operated in association with a widely varying range of belt loadings, the temperature of the nitrogen vapour at the outlet can vary widely even though the valve is controlled so as to give a desired product temperature at the tunnel exit. Accordingly, in practice, difficulties can arise in continuously maintaining the fan free of ice even though the exhaust gas is considerably diluted with air.
SUMMARY OF THE INVENTION
It is an aim of the present invention to provide a cooling apparatus which avoids the need to dilute with air the exhaust gas downstream of the freezing tunnel or other cooling chamber.
According to the present invention there is provided cooling apparatus comprising, a cooling chamber; means for introducing liquefied gas or its cold vapour into the chamber; an exhaust passage communicating with an outlet for exhaust gas comprising vapour of the liquefied gas from the cooling chamber; flow inducing means in said exhaust gas passage operable to draw exhaust gas therethrough; and at least one heat pipe having one end in heat transfer relationship with a region of said exhaust passage upstream of said flow inducing means and its other end in heat transfer relationship with a heat source, whereby, in operation, the heat pipe is able to transfer heat from said heat source to the exhaust gas and thereby warm the exhaust gas upstream of the flow inducing means.
The heat source preferably comprises a second passage through which relatively warm fluid is able to be passed. The relatively warm fluid is typically taken from a source of ambient air but may alternatively be taken from, for example, a source of water at approximately ambient temperature.
The flow inducing means is preferably a fan having a rotor located in said exhaust passage. A second fan is preferably employed to create the flow of air through the second passage.
Operation of the apparatus according to the invention makes it possible to warm the exhaust gas to above freezing point so as to prevent the deposition of ice on the fan. Moreover, if the relatively warm fluid is air taken from a factory or room which is air conditioned, the fluid may be returned to that room or factory at below ambient temperature, thus reducing the overall load on the air conditioning system. The apparatus according to the invention also obviates the need to dilute with air the gas extracted from the chamber, thus enabling the diameter of ducting used to define the exhaust passage to be less than any conventional systems.
The cooling apparatus may be of any kind in which liquefied gas, for example, liquid nitrogen, is used to perform a cooling duty. Thus, for example, the cooling chamber may comprise a tunnel through which articles to be cooled or frozen are advanced on a conveyor.
A heat pipe is a well known kind of transfer device which comprises a closed, typically elongate, chamber containing a working fluid under pressure. One end of the pipe is located in heat transfer relationship with a heat source from which heat is to be extracted and the other end of the pipe is located in heat transfer relationship with a medium which is to be heated. The working fluid and its pressure are selected such that the vapour phase of the working fluid condenses at the end of the pipe in heat transfer relationship with said medium (the exhaust gas in the apparatus according to the invention) and evaporates again at the other end of the heat pipe. Flow of liquid from the condensing end of the heat pipe to the evaporating end may be by gravity or by capillary action, or a combination of both. The heat pipe has at least one passage for the flow of vapour in the opposite direction to that of the liquid. Such flow takes place naturally as the result of the condensation of liquid at one end of the pipe.
In the apparatus according to the invention, the working fluid is preferably a fluorocarbon refrigerant, for example FREON R-22.
If desired, the heat pipe may have external fins to facilitate transfer of heat.
Preferably, if the relatively warm fluid is air, the flow of air through the second passage is, in operation, from two to three times that of the exhaust gas. Preferably, the flow of relatively warm air is created by a fan in the second passage upstream of the heat pipe. The speed of the fan in the first passage may be controlled in response to a temperature sensor located at or near the outlet of the cooling chamber. Alternatively, the speed of the fan may be linked to the position of a control valve in a pipeline for supplying liquefied gas (through its cold vapour) to the cooling chamber. The speed of the fan, if provided, in the second passage may be similarly controlled.
BRIEF DESCRIPTION OF THE DRAWING
The apparatus according to the invention will now be described by way of example with reference to the accompanying drawing, which is a schematic diagram of a freezing tunnel fitted with an exhaust system in accordance with the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to the drawing, there is illustrated a liquid nitrogen freezing tunnel 2. Such freezing tunnels are well known in the art and are readily available commercially, for example, from BOC Limited, Morden under the trademark BOC CRYOMASTER. Accordingly, the internal configuration and mode of operation of the freezing tunnel 2 need not be described in detail herein. The freezing tunnel 2 is provided with a liquid nitrogen supply pipeline 4 having a control valve 6 disposed therein. The pipeline 4 communicates with a source of liquid nitrogen (not shown). The tunnel 2 has an entrance 8 and an exit 10. Food products to be frozen are advanced into the tunnel 2 through the entrance 8 and leave through the exit 10. Within the tunnel 2, the food products come into contact with liquid nitrogen and its cold vapour, the latter flowing countercurrently to the food products. The food products are thereby frozen. Cold vapour is withdrawn from the tunnel 2 through an outlet 12 in its roof at a region near the entrance 8. The outlet 12 forms one end of an exhaust passage 14. The exhaust passage 14 comprises, in sequence, a first length of ducting 16 communicating at one of its ends with the outlet 12; a first channel 20 of a heat exchanger 18, the first channel 20 communicating with the length of ducting 16 at, in use, the cold end 24 of the heat exchanger 18; and a second length of ducting 28 communicating at one of its ends with the first channel 20 of the heat exchanger 18 at its warm end 26. The other end of the length of ducting 28 communicates with a stack (not shown) for safely venting exhaust gas from the freezing tunnel to the atmosphere outside the room (not shown) in which the tunnel 2 is located. A fan 30 is disposed in the second length of ducting 28 and is operable to create a flow of exhaust gas from the tunnel 2 through the first passage 14 to the stack (not shown).
The apparatus is provided with a second passage 32 for the flow of an air stream. The passage 32 extends from an inlet 34 which is open to the atmosphere outside the tunnel 2 with or outside the room (not shown) in which the tunnel 2 is located. The inlet 34 is formed in a third length of ducting 36 which terminates in a second channel 22 through the heat exchanger 18 at its warm end 26. A second fan 38 is located in the ducting 36. The second passage extends from the ducting 36 through the channel 22 into a fourth length of ducting 40 communicating with the channel 22 at the cold end 24 of the heat exchanger 18. The second passage 32 and the fourth length of ducting 40 terminate in an outlet 42 communicating with the atmosphere outside the tunnel 2 in the room in which that tunnel in the room in which that tunnel is located.
Typically, the heat exchanger 18 is located with its channels 20 and 22 generally vertical. With the channels so disposed, a plurality of heat pipes 44 (only one of which is shown) each having external fins 46 extends from the interior of the channel 20 through a column wall 48 separating the channel 20 from the channel 22 into the channel 22. The heat pipes 44 are each inclined at a small angle, but greater than 5° to the horizontal. The end of each heat pipe 44 in the channel 20 is located above that in the channel 22. The arrangement is preferably such that no exhaust gas can pass from the first channel 20 to the second channel 22 and no air in the opposite direction.
In operation of the tunnel 2 to freeze food products, cold nitrogen vapour is generated within the tunnel 2. Both the fans 30 and 38 are operated. The fan 30 draws cold nitrogen vapour from the interior of the tunnel 2 (in admixture with air leaking into the interior of the tunnel 2 from its entrance 8) through the first passage 14. The fan 38 draws a flow of ambient air through the second passage 32 from its inlet 34 to its outlet 42. The heat pipes 44 effect heat exchange between the flow of exhaust gas and the flow of air. The flow of exhaust gas through the channel 20 causes working fluid (typically FREON R 22) within the heat pipes 44 to condense. Condensate flows under gravity through the heat pipe 44 to its end within the second channel 22. The relatively warm ambient air causes such liquid to vaporise and there is a resultant flow of vapour in the opposite direction back to the end of the heat pipe 44 located in the channel 20. There is in consequence rapid transfer of heat from the channel 22 to the channel 20 with the result that the exhaust gas leaving the channel 20 at the warm end of the heat exchanger 18 is warmed to above ambient temperature.
In a typical example of the apparatus according to the invention, the exhaust gas leaving the tunnel 2 through its outlet 12 has a temperature of minus 40° C. and the air entering the second passage 32 through the inlet 34 has a temperature of +19° C. The heat pipes 44 are effective to warm the exhaust gas to +16° C., the cooled air leaving the channel 20 at the cold end 24 of the heat exchanger 18 at a temperature of +4° C. It can therefore be appreciated that no ice will be deposited on any surface of the fan 30. Moreover, we have found that there is surprisingly no or little deposition of ice on the heat transfer surfaces of the heat pipes 44 even during prolonged operation of the apparatus.
If desired, the apparatus according to the invention may be arranged to permit a small proportion of the exhaust gas to by-pass the heat exchanger 18.
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A cooling apparatus comprises a cooling chamber (2), means (4) for introducing liquefied gas or its cold vapor thereinto, an exhaust passage (16) having flow inducing means associated therewith and a heat transfer means (46) associated with said exhaust passage (16) in which the heat transfer means operates to transfer heat from a heat source to the exhaust gas.
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BACKGROUND OF THE INVENTION
This invention relates to a combinational weighing machine for weighing articles with a plurality of weighing devices, combining the measured weight values outputted from the weighing devices to select a combination having a total weight value within an allowable range, and collecting articles discharged from those of the weighing devices corresponding to the selected combination.
It has been known to use a combinational weighing machine of this kind by supplying articles to weigh hoppers through respective pool hoppers, using load cells to measure the weight of articles in each weigh hopper, causing a microcomputer to calculate the combinations of the weight values received from the load cells, comparing the results of the calculation with a target weight value and selecting a particular combination with the total weight that is the closest to the target weight value within a certain limitation. Many combinational weighing machines used for automatically packaging food items such as potato chips and wrapped candy have a plurality of (say, 14) weighing devices arranged in a circle with a discharge chute (or collection chute) 1, as shown in FIG. 6, disposed below the weighing devices. Such a discharge chute 1 is typically conical in shape, having an upper hopper 2 and a lower chute 3. The upper hopper 2 has an article receiving opening 2a with a large diameter at the top and its lower edge connected to the upper opening of the lower chute 3 which is also conically shaped and has a discharge opening 3a of a smaller diameter at the bottom. Thus, articles, which have been discharged from weighing devices belonging to a combination selected by a combinational calculation, slide down the conically shaped inner surface of the discharge chute 1 towards the discharge opening 3a at the bottom, are discharged through the discharge opening 3a with small diameter and are collected, say, in a bag being formed by a bag maker-packaging machine disposed below the weighing machine. Weighing and packaging, as described above, must be carried out as speedily as possible (say, at a rate of about 90 cycles/minute) for economical reasons. In this regard, there would be no problem if the articles discharged into the discharge chute 1 would slide down on straight trajectories towards the discharge opening as shown by arrows A and B indicated in FIG. 6. If articles are discharged into the discharge chute 1 from a weighing device of which the neighboring weighing devices were not selected in the combination and hence are not discharging articles therefrom, for example, the articles discharged from such an "isolated" weighing device tend to spread sideways as they slide down the inner surface of the discharge chute 1 because there are no other articles simultaneously sliding down in the neighboring downward paths.
Thus, some of them may spiral down on an elongated path towards the discharge opening 3a, as shown by arrow C. Since some of the articles will take the shortest route and quickly arrive at the discharge opening 3a, the articles, although discharged from the same weighing device at the same time, will be forming a relatively long line when being discharged from the discharge opening 3a, taking a relatively long time to be completely discharged.
If a relatively long time is required to discharge all articles dropped into the discharge chute at the same time, the timing for sealing the bag into which these articles have been dropped, as well as the timing for opening the weigh hopper for the next cycle of operation, will be delayed accordingly. This affects the efficiency of the weighing machine adversely.
If two weighing devices which are diametrically opposite to each other with respect to the discharge chute are selected in a combinational calculation, the articles dropped therefrom will slide down generally towards each other, as indicated by arrows A and B in FIG. 6. Head-on collisions are likely to take place, causing the articles to break or crack and thereby affecting the commercial value of the products adversely.
In view of the situation described above, Japanese Utility Model Publication 5-37226 disclosed a discharge chute 1 provided, as shown in FIG. 7, with a cylindrical buffer 4 at the center of the discharge opening 3a in order to prevent head-on collisions of the articles. Such a device will be able to prevent direct collisions between articles dropped from mutually opposite weighing devices, but it will have no effect in preventing articles from spiraling down the surface of the discharge chute 1. Moreover, since the sliding articles will collide with the buffer 4 at a relatively large angle θ, as shown in FIG. 7, they do not bounce from the buffer 4 into a vertical direction straight towards the discharge opening 3a. In other words, such a buffer does not make it possible to collect discharged articles efficiently and hence cannot significantly improve the efficiency of the weighing machine.
It has also been attempted to design the lower chute 3 such that its inner surface will have a parabolic cross-sectional shape. This will have the effect of causing the articles to naturally accelerate towards the discharge opening 3a by the force of gravity, and the articles are likely to all arrive at the discharge opening 3a at the time. This will reduce the probability of collisions between articles, but the height of the weighing machine will increase because the articles are cause to drop vertically downward towards the discharge opening by the force of gravity alone.
SUMMARY OF THE INVENTION
It is therefore an object of this invention to provide a combinational weighing machine capable of quickly leading all articles dropped into its chute towards its discharge opening and preventing collisions among them.
A combinational weighing machine embodying this invention, with which the above and other objects can be accomplished, may be characterized as comprising not only a plurality of weighing devices for weighing articles and outputting signals indicative of the weight values of the weighed articles and a control system for calculating combinations of the weight values, selecting a combination of weighing devices according to a given criterion and causing articles to be discharged from the selected combination of weighing devices, but also a discharge chute for receiving the discharged articles and leading them to a discharge opening and a guide member disposed inside the discharge chute with its outer surface serving to deflect the articles colliding therewith into a vertically downward direction. For combinational weighing machines with weighing devices arranged in a circle, buffers may be provided to partition in the circumferential direction the passageway for discharged articles between the guide member and the discharge chute.
After a combinational weighing machine according to this invention measures the weights of articles supplied to its individual weighing devices, its control system calculates combinations of the measured weights, selects a combination satisfying a certain criterion and causes articles to be discharged from the selected weighing devices into the discharge chute. The discharged articles slide down over the sloped inner surface of the discharge chute, collide with the guide surface of the guide member and are deflected thereby into the vertically downward direction towards the discharge opening.
If buffers are provided according to this invention to a combinational weighing machine with circularly disposed weighing devices, articles are prevented from spiraling down on the inner surface of the discharge chute even if they were discharged from a weighing device of which the neighboring weighing devices were not selected and not discharging their articles. Instead, the discharged articles slide down approximately radially and collide with the guide member at a specified angle so as to be deflected into a vertically downward direction.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and form a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the principles of the invention. In the drawings:
FIG. 1 is a schematic sectional side view of a part of a combinational weighing machine embodying this invention;
FIGS. 2A and 2B are respectively a plan view and a horizontal view of the middle chute of the weighing machine of FIG. 1;
FIG. 3 is a block diagram of the signal processing system of the weighing machine of FIG. 1;
FIG. 4 is a schematic sectional side view of a part of another combinational weighing machine embodying this invention;
FIG. 5 is a plan view of the discharge chute of the combinational weighing machine of FIG. 4;
FIG. 6 is a plan view of a prior discharge chute; and
FIG. 7 is a sectional side view of another prior art discharge chute.
DETAILED DESCRIPTION OF THE INVENTION
In what follows, the invention is described more in detail by way of examples with reference to drawings.
A combinational weighing machine embodying this invention, as illustrated in FIG. 1, has its article supply part 15 disposed on a casing 14 which is supported by a plurality of legs 12 on a main frame 10. The article supply part 15 includes a dispersion feeder 18 having a flat conical shape and provided with a vibrator 16 disposed at the center of a table (not shown) on the casing 14, a plurality of supply feeders 22 distributed radially around and below the dispersion feeder 18 and each provided with a vibrator 20, and pool hoppers 24 individually associated with the supply feeders 22 and disposed in a circle below article discharging (radially outward) ends of the individual supply feeders 22.
Supported on the outer circumference of the casing 14, there are a plurality of weighing devices 26, each including a weighing unit 27 such as a load cell and a weigh hopper 28 supported by the weighing unit 27, disposed in a circle individually corresponding to the pool hoppers 24. Each pool hopper 24 and weigh hopper 28 is provided with a gate (respectively shown at 24a and 28a), adapted to open and close as shown by double-headed arrows. Gate-operating Mechanisms and motors for the pool hoppers 24 and the weigh hoppers 28 are enclosed inside the casing 14.
A conically tubular discharge chute (or collection chute) 30 is disposed below the weigh hoppers 28, composed essentially of an upper chute 32, a middle chute 34 and a lower chute 36, which are each conically tubular and connected together sequentially from above. The upper chute 32 is positioned such that its article-receiving top opening 32a is capable of receiving articles discharged from the weigh hoppers 28 and is supported by the legs 12 through connecting members 13. Four partition boards 38 are attached to the inner surface of the upper chute 32, separated from each other circumferentially.
As shown more in detail in FIGS. 2A and 2B, the middle chute 34 includes a conically tubular main body 35, four buffers 37 and a conically tubular guide member 39. This guide member 39 is disposed so as to penetrate the main body 35 through its center. The four buffers 37 are disposed radially between the main body 35 and the guide member 39, their two contact surfaces connected to the inner surface of the main body 35 and the outer surface of the guide member 39, thereby circumferentially dividing the annular passageway 42 created between the main body 35 and the guide member 39 into four sections. The buffers 37 also serve as supporting means through which the guide member 39 is supported by the main body 35. The middle chute 34 is arranged such that its upper opening is adjacent to the lower opening of the upper chute 32 and its four buffers 37 match the partition boards 38 shown in FIG. 1, supported by the frame 10 through brackets 40 and 41.
The lower chute 36 is supported by the frame 10 through brackets 44 such that its upper opening is adjacent to the bottom part of the guide member 39 and the buffers 37. The bottom part of the lower chute 36 forms a discharge opening 36a with a small diameter through which weighed articles are discharged together. A packaging machine 46 is disposed below the discharge opening 36a such that the weighed articles discharged through the discharge opening 36a are received in a bag (not shown) through an article-receiving opening 46a of the packaging machine 46.
Steps in the operation of the weighing machine are described next.
Articles to be weighed are transported by a conveyor (not shown), placed on the dispersion feeder 18 through a supply chute (not shown) and dispersed and distributed into the pool hoppers 24 by the vibrations of the dispersion feeder 18 and the supply feeders 22. After being temporarily stored in the pool hoppers 24, they are discharged therefrom as the gates 24a are opened and received by the associated weigh hoppers 28. The weight of the batch of articles in each weigh hopper 28 is measured by the associated weighing unit 27. Signals indicative of the weight values obtained by the weighing units 27 are processed as described below.
As shown in FIG. 3, the over-all operation of the weighing machine is controlled by a central processing unit (CPU) 54. When the weights of article batches are measured by the weighing units 27, a switch signal "a" is outputted to a multiplexer (MUX) 50. In response, the multiplexer 50 causes the weighing units 27 to output, in a specified sequence, their weight signals "d" indicative of the measured weights of the article batches. The weight signals "d" outputted from the individual weighing units 27 are amplified by the corresponding signal processing circuits 48, each including an amplifier and a filter, converted into digital signals by a analog-to-digital converter (A/D) 52 and inputted to the central processing unit 54.
The central processing unit 54 carries out combinational calculations, based on the weight signals thus received, selects a combination on the basis of the combinational calculations and a certain criterion (such as the combination with a total weight which is close to a predetermined target weight value and within an allowable range), and outputs a selection signal "b" indicative of the selected combination. When the selection signal "b" is received by an open signal generating means 56, an open signal "c" for controlling the motion of gate drivers 58 of the weighing devices 26 is thereby generated, causing the gates 28a of only those of the weigh hoppers 28 selected in the combination are opened to discharge the articles therefrom into the discharge chute 30. New batches of articles are thereafter supplied into these weigh hoppers 28, which have just discharged their contents, from the corresponding ones of the pool hoppers 24 for the next cycle of combinational calculations.
The articles discharged from the weigh hoppers 28 are adapted to mostly land somewhere near the article-receiving top opening 32a of the upper chute 32. Thereafter, these articles slide down over the inner surface of the upper chute 32, are thrown into the middle chute 34 in a diagonally downward direction, and collide with the guide member 39, as shown in FIG. 1, by making an angle θ with its guide surface 39a, or its outer circumferential surface. The angle α of the conical shape of the guide member 39 (as shown in FIG. 1) is so selected that articles colliding therewith at the angle of θ, as explained above, will be deflected into a vertically downward direction (as shown by downward arrows in FIG. 1). In other words, the horizontal component of the motion of the articles generated as they slide down inside the upper chute 32 is eliminated by their collision with the guide surface 39a, and the articles are forcibly deflected so as to drop naturally downward towards the discharge opening 36a. Thus, the articles can be collected at the discharge opening 36a quickly and efficiently.
If one of the weighing devices 26 selected by combination calculations of the central processing unit 54 turns out to be isolated from the other selected weighing devices 26, the articles discharged from the weigh hopper 28 of such isolated weighing device 26 tend to move sideways, as explained above, because there are no articles being dropped from the adjoining weighing devices. Some of them may be pushed sideways and start spiraling down into the middle chute 34. Such spiral motion of articles, which might otherwise result in such a situation, can be prevented by the buffers 37 which deflect articles beginning to move sideways and to spiral. Deflected by the buffers 37, the spiraling articles will collide with the guide surface 39a at an angle of θ and thereafter drop vertically downward towards the discharge opening 36a, as described above. In other words, the discharged articles are prevented from forming a long line as they enter the middle chute 34 from the upper chute 32.
As a result, articles discharged in different cycles of the combinational calculations are dependably separated as they are discharged. This makes it possible to reduce the time required for the thermal sealing of bags by the packaging machine 46 and to reduce also the interval between successive discharges of articles from the weighing machine. In other words, since discharged articles are prevented from spiraling down the chute, articles discharged in one cycle of combinational calculations do not mix into the articles discharged in the next cycle, even if the period of cyclic operation of the combinational weighing machine is reduced.
Since the downward deflection of articles is accomplished by the sloped guide surface 39a, the height of the chute need not be increased, as was the case with a chute with a parabolical cross-sectional shape. Since the guide member 39 serves to prevent direct collisions among the articles and since the articles collide with the guide surface 39a (which is stationary and may be of a softer material) at a relatively small angle θ, furthermore, there is a reduced probability of cracks and breakages.
Should jams tend to occur at the discharge opening 36a or in the package-making bags because discharged articles arrive at the discharge opening 36a at the same time according to this invention, the timing of opening the weigh hoppers 28 of selected weighing devices 26 may be slightly modified such that the discharged articles will be discharged in a line of a desired length.
Another combination weighing machine according to a second embodiment of the invention is described next with reference to FIG. 4, wherein components which are equivalent or at least similar to those described above with reference to FIG. 1 are indicated by the same numerals. For convenience, it will be assumed specifically that this combinational weighing machine has fourteen weighing devices, fourteen pool hoppers and fourteen supply feeders, disposed in a circle around a dispersion feeder 18.
This combinational weighing machine is different from the one shown in FIG. 1 wherein the upper chute 32 and the lower chute 36 of its discharge chute 30 are connected together and a guide member 39 is provided separately from the discharge chute 30, disposed at the center of the discharge chute 30, hung from the casing 14 by means of an externally threaded rod 60.
As shown more clearly in FIG. 5, the upper chute 32 is formed with two each of larger units 321 each corresponding to four weighing devices and smaller units 322 each corresponding to three weighing devices, assembled together so as to be approximately in a conical tubular shape as a whole. Each larger unit 321 is formed by bending an approximately fan-shaped sheet of stainless steel so as to have four nearly rectangular trapezoidal slide surfaces 321a, each becoming narrower on one side, and flanges 321b extending from and bent upward along both edges, each of the slide surfaces corresponds to one of the weighing device. Similarly, each smaller unit 322, corresponding to three weighing devices, is formed by bending an approximately fan-shaped sheet of stainless steel so as to have three nearly rectangular trapezoidal slide surfaces 322a, each becoming narrower on one side, and flanges 322b extending from and bent upward along both edges, each of the slide surfaces corresponding to one of the weighing devices. The lower chute 36 is conically tubular, the angle of the cone varying in three stages in the vertical direction, as shown in FIG. 4.
The guide member 39 is approximately of a conically tubular shape with the angle of the conic outer surface varying in three stages to form three guide surfaces 39b, 39c and 39d arranged in the vertical direction such that articles sliding down over the slide surfaces 321a and 322a will be deflected thereby by colliding with the guide member 39 and fall vertically downward. A cross-shaped attachment member 57 is inserted and fastened to the top opening of the guide member 39, and the externally threaded rod 60 engages with a nut 59 affixed to the attachment member 57 at the center such that the vertical position of the guide member 39 relative to the discharge chute 30 can be changed (as shown by double-headed arrow) by rotating either the rod 60 or the guide member 39 itself. The guide member 39 at another position is indicated by a broken line in FIG. 4.
The vertical position of the guide member 39 relative to the discharge chute 30 is adjusted, depending on how the articles are deflected when colliding. It may be adjusted also so as to widen the passage 42 when the total amount of the discharged articles is large, or when the target weight of the combinational calculations is large, and to make it narrower when the target weight is small.
Although no buffers are provided according to this embodiment of the invention, the upwardly bent flanges 321b and 322b serve to prevent motion of articles in circumferential directions, and spiral motion of articles can be prevented just as effectively.
Although the invention has been described above with reference to only a limited number of examples, these examples are not intended to limit the scope of the invention. Many modifications and variations are possible within the scope of the invention. For example, the slope of the conical surface of the guide member or the chute may change continuously such that, for example, the cross-sectional shape of their surface may be a parabola or some other higher-order curve. Any such modifications and variations that may be apparent to a person skilled in the art are intended to be within the scope of the invention.
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A combinational weighing machine has not only a plurality of weighing devices for weighing articles and outputting signals indicative of their weight values and a control system for calculating combinations of the weight values, selecting a combination of weighing devices according to a given criterion and causing articles to be discharged from the selected combination of weighing devices, but also a discharge chute for receiving the discharged articles and leading them to a discharge opening and a guide member disposed inside the discharge chute with a sloped outer surface serving to deflect the articles colliding therewith into a vertically downward direction.
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This is a continuation of prior application U.S. Ser. No. 9/302,138 filed on Apr. 29, 1999, entiled TOOTHBRUSH HAVING CONTROLLED HEAD MOVEMENT, which co-pending prior application granted as U.S. Pat. No. 6,292,973 B1 on Sep. 25, 2001 and is incorporated herein by reference.
FIELD OF THE INVENTION
The present invention relates to toothbrushes and in particular to toothbrushes whose head position can be manipulated by applying pressure to specific segments of the handle.
BACKGROUND OF THE INVENTION
Conventional toothbrushes comprise uniform tufts of bristles each having a first end which is held captive in and fixed to a brush head, and a second end which is free and which is used for brushing. The free ends of the various tufts present a surface envelope which is capable of slight deformation by the bristles bending when they come in contact with a surface to be brushed, but which is incapable of adequately matching a surface having a complex shape. Such a complex surface is present in the mouth, wherein the teeth generally lie in a “C” shaped curve within the upper and lower jaw, each row of teeth consequently having a convex outer curve and a concave inner curve.
In toothbrushing the desire of users to cause the bristles to conform to the teeth is expressed by the forceful application of the brush to adequately deform the bristles to the arcuate contours of the dentiture. Such forceful application of the brush against the teeth merely leads to excessive wear of the tooth surfaces and gums, without adequate conformation of the brush to the teeth to provide the desired cleaning.
Toothbrushes having a flexibly neck located between the brush head, containing the bristles, and the handle have been disclosed in the prior art to provide conformation of the brush to the contours of the dentiture. Examples of such flexibly neck toothbrushes include the toothbrushes disclosed in U.S. Pat. Nos. 759,490 and 4,520,526. U.S. Pat. No. 759,490 creates neck flexibility by interposing a flexibly resilient material between a rigid brush head and handle, which flexibly resilient material may be reinforced with a second such type of material. U.S. Pat. No. 4,520,526 creates neck flexibility by the alternatives of either removing part of the material from the top and bottom of the neck portion of the brush, or having an oval shaped hollow in the neck extending from one side to the other. Such flexibly resilient toothbrush necks permit the bristle head to yield relative to the handle when the user, whereby the danger of injury to the teeth and gums is reduced, applies excessive force. However, such flexure means do not allow the user the ability to control the contour of the brush head to the particular arch of the oral surface being brushed, to avoid the need to apply excessive force in the first instance.
U.S. Pat. No. 4,333,199 discloses a toothbrush whose head is pivotally mounted on a coiled spring above a recessed handle, such that the head is adapted to rotate and tilt as it is applied to the teeth. While such flexing action will allow the brush head to generally follow the arch of the oral surface being brushed, it provides no direct control by the user of the moving, tilting, and rotating action of the toothbrush head.
PCT International Application WO 89/10076, discloses a toothbrush having the capability of varying the angle between the brush head and the handle in order to position the brush head in parallel with a arcuate section of the dentiture. WO 89/10076 discloses a toothbrush having a handle pivotally connected to the head, wherein the handle is formed of a pair of spaced apart, rigid, upper and lower sides, which sides are pivotally linked together to be movable lengthwise relative to each other. Alternatively, the spaced apart, rigid, upper and lower sides may be connected by means of an elastic spacer layer, which will also allow them to be movable lengthwise relative to each other. Use of a such a pivotally connected handle and head, controlled by the lengthwise movement of the rigid sides of the toothbrush, to accurately control the position of the toothbrush head is difficult at best. Such lack of precise control is due to the fact that pivoting linkages, which lack rigidity or resistance will tend to move the head excessively; while, the alternative use of an elastic layer will limit the movement of the head proportional to the degree of elasticity therein.
There is a need in the art for a toothbrush, wherein the position of the toothbrush head can be more precisely controlled by the user, to position the head in conformity with the arcuate configuration of the dentiture.
SUMMARY OF THE INVENTION
The present invention encompasses a toothbrush comprised of an elongated handle formed of a relatively rigid, generally S-curved longitudinal backbone section, extending at one end into a relatively straight neck with a flattened head portion containing a plurality of bristle tufts extending therefrom and at the other end a broadened base; wherein, the generally S-curved longitudinal backbone is opposed by a corresponding generally S-curved section of a relatively resiliently flexible elastomeric material, such that the opposed S-curves form a generally elongate figure 8 having extending therethrough an upper and a lower aperture. During brushing of the teeth, the user can manipulate, i.e. apply pressure to, the upper relatively rigid S-curve backbone or to the opposed resiliently flexible elastomeric section, while simultaneously compressing an opposite rigid and/or elastomeric section, to position the bristle bearing toothbrush face in a controlled manner to conform to the arcuate configuration of the dentiture.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a longitudinal perspective view, showing the a first embodiment of the toothbrush of the present invention with an arbitrarily curved bristle pattern and a sufficiently clear elastomer about the handle and extending to the base of the neck, such that the S-curved relatively rigid backbone is visible.
FIG. 1A is a perspective view of the toothbrush of FIG. 1, wherein a vertical plane and horizontal plane have been added; the vertical plane being perpendicular to the face of the toothbrush and through the longitudinal axis, A—A.
FIG. 2 is a cross-section side plan view, showing a second embodiment of the toothbrush of the present invention, with a typical flat bristle pattern and a broadened base.
FIG. 3 is a cross-section side plan view, showing a third embodiment of the toothbrush of the present invention, with a typical flat bristle pattern and a broadened base.
FIG. 4 is a cross-section side plan view, showing a fourth embodiment of the toothbrush of the present invention, with a typical flat bristle pattern.
FIG. 5 is a perspective view of the toothbrush of FIG. 1, shown from the base and extending to the head thereof, with an arbitrary bristle pattern.
FIG. 6 is a cross-section side plan view, showing a fifth embodiment of the toothbrush of the present invention, with a typical flat bristle pattern.
FIG. 7 is a cross-section side plan view, showing a sixth embodiment of the toothbrush of the present invention, with a typical flat bristle pattern.
FIG. 8 is a cross-section side plan view, showing a seventh embodiment of the toothbrush of the present invention, with a typical flat bristle pattern.
FIG. 9 is a cross-section side plan view, showing an eighth embodiment of the toothbrush of the present invention, with a typical flat bristle pattern.
DETAILED DESCRIPTION OF THE INVENTION
Referring now to the drawings, wherein like reference numerals refer to the same or similar elements among the several figures, and in particular referring to FIG. 1; wherein there is shown a toothbrush, 12 . FIG. 1 is a perspective view of a toothbrush of the present invention about a longitudinal axis A—A, with an upper side, 13 , and a opposed lower side, 15 , wherein the toothbrush has a head, 14 , integral to and extending from a neck, 16 , which neck is integral to and extending from a handle, 18 , which handle is integral to an extending from a broadened base, 24 . The head, 14 , having a face, 20 , on the upper side, 13 , thereof; from which face extend rows of bristle tufts, 22 , transverse to the longitudinal axis A—A.
In accordance with the present invention, the head, 14 , can flex relative to the handle, 18 , in the vertical plane, identified as V in FIG. 1A; but, is substantially rigid relative to the handle in the horizontal plane, identified as H in FIG. 1 . Such flexibility is due to the fact that the handle, 18 , is multi-sectional, that is formed in sections of at least two materials having significantly different modulus of elasticity; one section being formed of a relatively rigid plastic and the other section being formed of a resiliently flexible elastomer. The relatively rigid plastic section comprises a generally S-curved longitudinal backbone, 26 , extending from the neck of the toothbrush to the broadened base, 24 , thereof. The resiliently flexible elastomeric section is also in the general shape of an S-curve, 28 , and in opposed relation to the generally S-curved longitudinal backbone, 26 , such that the opening of the generally S-curved rigid longitudinal backbone are closed by the generally S-curves of the resilient flexibly elastomeric section, 28 .
Together, the S-curved rigid longitudinal backbone, 26 and opposed generally S-curved resilient flexibly elastomeric section, 28 , form a generally elongated figure 8-shape. The interlocking S-curves that form the generally figure 8-shape handle define two aperture, an upper aperture, 30 , more proximate to the neck, 16 , and a lower aperture, 32 , more proximate to the broadened base, 24 ; both apertures are preferably approximately equal in cross-section area.
The apertures, 30 and 32 , are of sufficient cross-sectional area such that when the user applies a greater force to the relatively rigid backbone section, 26 , about the upper aperture, 30 , than to the opposed relative resiliently flexible section, 28 , about the upper aperture, 30 , or to the opposed relatively rigid backbone section about the lower aperture, 32 , the connected bristle bearing head, 14 , deflects to a position in the direction of the upper side, 13 , of the toothbrush. The forces involved in this manipulation by the user are illustrated in FIG. 1 by the opposed arrows at an acute angle to the longitudinal axis A—A. Correspondingly, the user can apply a greater force, at an appropriate angle, to the relatively resiliently flexible section, 28 , about the upper aperture, 30 , than to the corresponding relatively rigid backbone, 26 , about the upper aperture, 30 , such that the bristle bearing head, 14 , will deflect to a position in the opposite direction, i.e. away from the upper side, 13 , of the toothbrush.
The interlocking S-curve sections that form the handle are shown in FIG. 1 as being substantially equally spaced about the longitudinal axis A—A; however, in alternate embodiments of the present invention, the interlocking S-curves can be more forward of the longitudinal axis A—A, FIG. 2, or more behind the longitudinal axis A—A, FIG. 3 . Further, while in FIG. 1 the apertures 30 and 32 are generally oval with a relatively narrow transverse axis in relationship to a longer longitudinal axis, which longer longitudinal axis may be aligned with or at an acute angle to the longitudinal axis A—A of the toothbrush; these apertures can be rounder, with much greater transverse axial length in relationship to their longitudinal axial length, such as shown in FIG. 2 . Alternatively, the apertures, 30 and 32 , can be crescent shaped as illustrated in FIG. 8 .
In accordance with the present invention the head, 14 , the neck, 16 , the S-curved backbone, 26 , and the broadened base, 24 , are molded as an integral work-piece of relatively rigid polypropylene or other plastic with a similarly relatively rigid structure, such as a polyamide, i.e. nylon; or a polyester or a co-polyester, such as polyethylene terephthalate (PET), or a polycyclohexylene dimethylene terephthalate that is acid modified (PCTA); or a cellulosic plastic; or styrene acrylonitrile (SAN) or acrylonitrile butadiene styrene (ABS). The polypropylene or other rigid plastic is preferably of a Shore A Hardness ranging from 40 to 110, more preferably 60 to 110 and most preferably from 80 to 100. Suitable polypropylene is available from Huntsman Corporation, Longview, Tex., 75603 under the trade-designation Huntsman Polypropylene P4G3Z-039.
The relatively resiliently flexible elastomeric S-curve section, 28 , may be molded of a variety of elastomeric materials, most especially thermoplastic elastomers (TPE). Acceptable TPE materials for the relatively resiliently flexible S-curved elastomeric section, 28 , including styrene-ethylene/butylene-styrene (SEBS) Type styrene block copolymers, such as styrene-butadiene-styrene, styrene-isoprenestyrene, and related copolymers, as well as, thermoplastic polyurethane (TPU) or a thermoplastic vulcanate (TPV) which consists of a mixture of polypropylene and EPDM (ethylene propylene diene monomers) which is available as Santoprene (brand), described in U.S. Pat. No. 5,393,796; or Vyram (brand), another TPV consisting of a mixture of polypropylene and natural rubber, both Santoprene and Vyram being elastomers marketed by Advanced Elastomer Systems LP, Akron, Ohio 44311. Another, and preferred TPE is Dynaflex G6713 (brand), marketed by GLS Corp., Cary, Ill. 60013. These and other suitable elastomers have, typically, a Shore A hardness of from about 1 to 94, with about 15 to 60 being a preferred, and about 15 to 40 being most preferred.
The resiliently flexible elastomeric material can be overmolded about the handle, 18 , as shown in FIG. 4, a cross-section view, as the elastomic overmolded region. The resiliently flexible elastomic S-curved section is shown in FIG. 4 as areas, 38 and 40 , which are separated in the cross-section shown by the generally elongated S-curved relatively rigid backbone, 26 . The degree of flexibility of both the relatively rigid backbone section, 26 , and of the resiliently flexible elastomeric S-curve section, areas 38 and 40 , can be further controlled by varying the thickness thereof, i.e. to provide more or less flexibility.
If a substantially clear appearance is desired for the relatively rigid components of the toothbrush, i.e. the toothbrush head, 14 , the neck, 16 , the relatively rigid generally S-curved backbone section, 26 , and the broadened base, 24 , can be of polyester, such as polyethylene terephthalate or a copolyester, such as PCTA polyester or SAN, or a cellulosic plastic, such as cellulose acetate propionate (CAP). If a substantially clear appearance is desired for the resiliently flexible elastomeric components of the toothbrush, i.e. the resiliently flexible S-curved elastomeric section, 28 , certain TPE, or TPUS, or ethylene vinyl acetate (EVA) materials can be used. A preferred substantially clear TPE is available from Teknor Apex Company, Pawtucket, R.I. 02861, sold under the trade-designation 96-E0807A-03NT WAT CLR.
Alternative embodiments of the present invention can contain within the upper and lower segments of the generally figure 8 shaped handle, 18 , not only the two apertures previously discussed; but, also within each segment a single aperture or a grouping of a plurality of apertures, i.e. three, four, five or six apertures. In the case of either a single or such a grouping of apertures in the handle, 18 , the relatively rigid backbone forms a first side of each aperture or grouping of apertures and a relatively resilient flexibly elastomer forms the second side of each aperture or grouping of apertures. The aperture(s), may be generally crescent, generally oval or generally round, with their longitudinal axis generally aligned with or at an acute angle to the longitudinal axis of the toothbrush A—A, as shown by angle “a” in FIGS. 2, 3 and 6 . Such multiple apertures may all be located substantively about the longitudinal axis of the toothbrush, or on either side thereof. Illustrative illustrations of such alternative embodiments are shown in FIGS. 6, 7 and 9 .
As the broadened base, 24 , and the overall dual component construction of the present invention add significantly to the weight of a typical toothbrush, the base can be hollow to minimize the additional weight. As shown in FIG. 5, such a hollow base can be formed of an inner injection molded relatively rigid polypropylene shell, 34 , surrounded by the resilient flexibly elastomeric material, 36 which comprises the resiliently flexible elastomeric material.
Multi-section component toothbrushes of the present invention can be molded by conventional injection molding technology, which is well known in the art. For example, in accordance with the present invention, the resiliently flexible elastomeric material section may be overmolded about the handle, 18 , by a second injection step, after the first step of injection molding the frame or skeleton, which is comprised of the hard bristle implanting head, 14 , neck, 16 , relatively rigid handle backbone section, 26 , and broadened base, 24 . In this second injection step the frame is positioned in a second mold into which the resiliently flexible elastomeric material is injected about the handle, 18 , thereof; more specifically, about the relatively rigid backbone section, 26 , extending from the broadened base, 24 , to the base of the neck, 16 .
Facilitation of the two step injection molding of toothbrushes of the present invention can be by using a two component mold. Two component molds are available from numerous suppliers, including Machines Boucherie N.V., Izegem, Belgium; Anton Zahoransky GmbH & Company, Todtnau, Germany; or Braun Formenbau GmbH, Bahlingen, Germany; which molds can be mounted in typical injection molding machines for such implementing the two step injection process, such machines including 300 ton, two component injection molding machines available from Engel Vertriebsgesellschaft mbH, Schwertberg, Austria or Netstal-Maschinen AG, Nafels, Switzerland.
The toothbrush bristles may be implanted in the toothbrush face, 20 , using either typical staple technology or using more modern non-staple technology as disclosed in U.S. Pat. Nos. 4,635,313, 4,637,660, 4,954,305, 5,045,267, 5,609,890, 5,390,984, 5,533791, and 5,823,633. Such non-staple technology involves processes wherein the bristle tufts, 22 , are fused into the toothbrush head, 14 , by heating both the bristle tufts, 22 , and the toothbrush head, 14 , which are then brought together in a fusion process; or, wherein the ends of the bristle tufts, 22 , are pre-positioned in the injection mold prior to the introduction of the toothbrush material, which toothbrush material is subsequently injected about the ends of the bristle tufts, 22 , locking the bristle tufts, 22 , in place in the toothbrush head, 14 .
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The present invention relates to a toothbrush having a handle formed of interlocking opposed S-curved sections, the first being relatively rigid and the second relatively resiliently flexible, the opposed S-curved sections forming a generally elongated FIG. 8 , having a transverse aperture within each segment of the FIG. 8 , such that during brushing the user can manipulate the relatively rigid and resiliently flexible section to position the bristle bearing face of the toothbrush to conform to the arcuate configuration of the dentiture.
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CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present invention is a continuation-in-part of U.S. patent application Ser. No. 09/179,519 filed Oct. 27, 1998 for ELECTRONIC MAIL SYSTEM, METHOD OF SENDING AND RECEIVING ELECTRONIC MAIL, AND STORAGE MEDIUM. The disclosure of that application is specifically incorporated herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an electronic mail system that sends and receives electronic mails to which musical tone control information is attached, a method of sending and receiving such electronic mails, and a storage medium that stores a program for sending and receiving the electronic mails.
[0004] 2. Prior Art
[0005] Conventionally, in order to send and receive musical sound or voice with an electronic mail, voice data produced by converting a voice signal representing the voice or sound into digital data has been used as an attached file to the electronic mail.
[0006] In the known electronic mail system as described above, however, the attached file is formed of voice data that contains a large quantity or volume of data, and therefore it takes a long time to send and receive an electronic mail to which such a file is attached. In particular, when a relatively low-speed modem is used, or a communication line is busy, it is undesirable to send or receive the electronic mail with the attached file containing voice data, because the communication line is kept occupied over a long period of time.
SUMMARY OF THE INVENTION
[0007] It is the object of the invention to provide an electronic mail system which is capable of sending and receiving an electronic mail along with high-quality, small-quantity musical tone or voice data, a method of sending and receiving such an electronic mail, and a storage medium that stores a program for sending and receiving such an electronic mail.
[0008] To attain the object, according to a first aspect of the present invention, there is provided a receiving terminal connected to a communication line, for receiving, through the communication line, an electronic mail that is sent by a transmitting terminal connected to the communication line, comprising a receiving device that receives the electronic mail which is sent by the transmitting terminal, and to which song data comprising musical tone control information is attached, an opening device that opens the received electronic mail, and a reproducing device that automatically reproduces the song data attached to the electronic mail when the electronic mail is opened by the opening device.
[0009] Preferably, the song data comprising musical tone control information is MIDI data.
[0010] According to the first aspect, there is also provided a receiving terminal control method of controlling a receiving terminal connected to a communication line, for receiving, through the communication line, an electronic mail sent by a transmitting terminal connected to the communication line, comprising the steps of receiving the electronic mail which is sent by the transmitting terminal, and to which song data comprising musical tone control information is attached, opening the electronic mail, and automatically reproducing the song data attached to the electronic mail when the electronic mail is opened.
[0011] According to the first aspect, there is also provided a storage medium that stores commands readable by a machine, the commands causing the machine to execute a receiving terminal control module for controlling a receiving terminal connected to a communication line, for receiving, through the communication line, an electronic mail that is sent by a transmitting terminal connected to the communication line, the receiving terminal control module comprising a module that receives the electronic mail which is sent by the transmitting terminal, and to which song data comprising musical tone control information is attached, a module that opens the received electronic mail; and a module that automatically reproduces the song data attached to the electronic mail when the electronic mail is opened.
[0012] According to the first aspect as defined above, the receiving terminal receives the electronic mail sent by the transmitting terminal, along with song data comprising musical tone control information attached to the mail, the song data attached to the electronic mail is automatically reproduced when the electronic mail is opened. Therefore, since the song data comprising musical tone control information is attached to the electronic mail and sent to the receiving terminal, high-quality musical tone or voice represented by a small quantity of data can be transmitted and received along with the electronic mail. Further, upon opening of the electronic mail, the user need not open the attached file containing song data, and start an appropriate application for reproducing the song data in the opened file, thus assuring improved efficiency with which the user operates the receiving terminal.
[0013] A typical example of the musical tone control information is MIDI (Musical Instrument Digital Interface) data. The musical tone control information, however, is not limited to MIDI data, but may be any type of data whose quantity or volume is smaller than that of the original musical tone or voice, and which enables high-quality musical tone or voice to be reproduced.
[0014] The term “electronic mail” used in the appended claims means not only character data, but may also include image or picture data and/or a small quantity of voice data produced by converting a voice signal into digital data, in addition to the character data.
[0015] To attain the object, according to a second aspect of the present invention, there is provided a communication terminal connected to a communication line, for receiving, through the communication line, an electronic mail sent by a transmitting terminal connected to the communication line, and transferring the received electronic mail to a receiving terminal connected to the communication line and corresponding to an address of the electronic mail, comprising a receiving device that receives, from the transmitting terminal, the electronic mail to which song data comprising musical tone control information is attached, a storage device that stores the received electronic mail to which the song data is attached, a notifying device that notifies the receiving terminal of receipt of the electronic mail when receiving the electronic mail from the transmitting terminal, and a transfer device that retrieves the electronic mail and the song data attached to the mail from the storage device, and transfers the electronic mail and the song data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the notifying device.
[0016] According to the second aspect, there is also provided a communication terminal control method of controlling a communication terminal connected to a communication line, for receiving, through the communication line, an electronic mail sent by a transmitting terminal connected to the communication line, and transfers the received electronic mail to a receiving terminal connected to the communication line and corresponding to an address of the electronic mail, comprising the steps of receiving, from the transmitting terminal, the electronic mail to which song data comprising musical tone control information is attached, storing the received electronic mail to which the song data is attached in a storage device, notifying the receiving terminal of receipt of the electronic mail when receiving the electronic mail from the transmitting terminal, and retrieving the electronic mail and the song data attached to the mail from the storage device, and transferring the electronic mail and the song data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the communication terminal.
[0017] According to the second aspect, there is further provided a storage medium that stores commands readable by a machine, the commands causing the machine to execute a communication terminal control module for controlling a communication terminal connected to a communication line, for receiving, through the communication line, an electronic mail that is sent by a transmitting terminal connected to the communication line, and transfers the received electronic mail to a receiving terminal connected to the communication line and corresponding to an address of the electronic mail, the communication terminal control module comprising a module that receives, from the transmitting terminal, the electronic mail to which song data comprising musical tone control information is attached, a module that stores the received electronic mail to which the song data is attached, in a storage device, a module that notifies the receiving terminal of receipt of the electronic mail when the communication terminal receives the electronic mail from the transmitting terminal, and a module that retrieves the electronic mail and the song data attached to the mail from the storage device, and transfers the electronic mail and the song data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the communication terminal.
[0018] According to the second aspect as defined above, the communication terminal receives the electronic mail to which song data comprising musical tone control information is attached, from the transmitting terminal, and transfers the electronic mail to the receiving terminal. Thus, the transmitting terminal need not directly deliver the electronic mail to which song data is attached, to the receiving terminal, and therefore the function of the transmitting terminal may be simplified. Further, since the song data comprising musical tone control information is attached to the electronic mail and sent to the receiving terminal, high-quality musical tone or voice represented by a small quantity of data can be transmitted and received along with the electronic mail.
[0019] To attain the object, according to a third aspect of the invention, there is provided a transmitting terminal connected to a communication line, for receiving, through the communication line, an electronic mail sent by a transmitting terminal connected to the communication line, and transferring the received electronic mail to a receiving terminal connected to the communication line and corresponding to an address of the electronic mail, comprising a first storage device that stores a plurality of kinds of ornamental data that ornament the electronic mail sent by the transmitting terminal, and a plurality of kinds of song data attached to the electronic mail and comprising musical tone control information, a presenting device that presents the plurality of kinds of ornamental data and the plurality of kinds of song data stored in the first storage device, to the transmitting terminal, so that the transmitting terminal can select a combination of ornamental data and song data from the plurality of kinds of ornamental data and song data, and designate the combination as electronic mail data, a second storage device that retrieves the electronic mail data from the first storage device and stores the retrieved data, when the transmitting terminal requests the communication terminal to send the combination of ornamental data and song data selected and designated as the electronic mail data, to the receiving terminal, a notifying device that notifies the receiving terminal of receipt of the electronic mail when the electronic mail data is stored in the second storage device in response to the request from the transmitting terminal for sending the electronic mail, and a transfer device that retrieves the electronic mail data from the second storage device, and transfers the data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the notifying device.
[0020] Preferably, the plurality of kinds of song data comprising musical tone control information are MIDI data.
[0021] According to the third aspect, there is also provided a communication terminal control method of controlling a communication terminal connected to a communication line, for receiving, through the communication line, an electronic mail sent by a transmitting terminal connected to the communication line, and transfers the received electronic mail to a receiving terminal connected to the communication line and corresponding to an address of the electronic mail, comprising the steps of storing a plurality of kinds of ornamental data that ornament the electronic mail sent by the transmitting terminal, and a plurality of kinds of song data attached to the electronic mail and comprising musical tone control information, in a first storage device, presenting the plurality of kinds of ornamental data and the plurality of kinds of song data stored in the first storage device, to the transmitting terminal, so that the transmitting terminal can select a combination of ornamental data and song data from the plurality of kinds of ornamental data and song data, and designate the combination as electronic mail data, retrieving the electronic mail data from the first storage device and storing the retrieved data in a second storage device, when the transmitting terminals requests the communication terminal to send the combination of ornamental data and song data selected and designated as the electronic mail data, to the receiving terminal, notifying the receiving terminal of receipt of the electronic mail when the electronic mail data is stored in the second storage device in response to the request from the transmitting terminal for sending the electronic mail, and retrieving the electronic mail data from the second storage device, and transferring the retrieved data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the communication terminal.
[0022] According to the third aspect, there is further provided a storage medium that stores commands readable by a machine, the commands causing the machine to execute a communication terminal control module for controlling a communication terminal connected to a communication line, for receiving, through the communication line, an electronic mail that is sent by a transmitting terminal connected to the communication line, and transfers the received electronic mail to a receiving terminal connected to the communication line and corresponding to an address of the electronic mail, the communication terminal control module comprising a module that stores a plurality of kinds of ornamental data that ornament the electronic mail sent by the transmitting terminal, and a plurality of kinds of song data attached to the electronic mail and comprising musical tone control information, in a first storage device, a module that presents the plurality of kinds of ornamental data and the plurality of kinds of song data stored in the first storage device, to the transmitting terminal, so that the transmitting terminal can select a combination of ornamental data and song data from the plurality of kinds of ornamental data and song data, and designate the combination as electronic mail data, a module that retrieves the electronic mail data from the first storage device and stores the retrieved data in a second storage device, when the transmitting terminals requests the communication terminal to send the combination of ornamental data and song data selected and designated as the electronic mail data, to the receiving terminal, a module that notifies the receiving terminal of receipt of the electronic mail when the electronic mail data is stored in the second storage device in response to the request from the transmitting terminal for sending the electronic mail, and a module that retrieves the electronic mail data from the second storage device, and transfers the retrieved data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the communication terminal.
[0023] According to the third aspect as defined above, the plural kinds of ornamental data and song data stored in the first memory device are presented to the user on the side of the transmitting terminal, so that the user can select a desired combination of ornamental data and song data, and designate it as electronic mail data. The communication terminal then delivers the electronic mail data, i.e., the selected combination of ornamental and song data, to the receiving terminal. With this arrangement, the user of the transmitting terminal need not prepare electronic mail data from scratch, and the number of procedures to be taken by the user can be thus reduced. Also, since the song data comprising musical tone control information is attached to the electronic mail and sent to the receiving terminal, high-quality musical tone or voice represented by a small quantity of data can be transmitted and received along with the electronic mail.
[0024] To attain the object, according to a fourth aspect of the invention, there is provided an electronic mail system including a communication line, and at least one transmitting terminal and at least one receiving terminal connected to each other through the communication line, the transmitting terminal sending an electronic mail to the receiving terminal corresponding to an address of the electronic mail through the communication line, wherein the transmitting terminal comprises an attaching device that attaches song data comprising musical tone control information, to the electronic mail, and a transmitting device that transmits the electronic mail to which the song data is attached, to the receiving terminal, and the receiving terminal comprises a receiving device that receives the electronic mail which is sent by the transmitting terminal, and to which the song data comprising musical tone control information is attached, an opening device that opens the received electronic mail, and a reproducing device that automatically reproduces the song data attached to the electronic mail when the electronic mail is opened by the opening device.
[0025] To attain the object, according to a fifth aspect of the invention, there is provided an electronic mail system including a communication line, and at least one transmitting terminal, at least one receiving terminal, and at least one communication terminal connected to each other through the communication line, the communication terminal receiving, through the communication line, an electronic mail sent by the transmitting terminal and transferring the received electronic mail to the receiving terminal corresponding to an address of the electronic mail, wherein the transmitting terminal comprises an attaching device that attaches song data comprising musical tone control information, to the electronic mail, and a transmitting device that transmits the electronic mail to which the song data is attached, to the communication terminal, the communication terminal comprises a first receiving device that receives, from the transmitting terminal, the electronic mail to which the song data comprising musical tone control information is attached, a storage device that stores the received electronic mail to which the song data is attached, a notifying device that notifies the receiving terminal of receipt of the electronic mail when receiving the electronic mail from the transmitting terminal, and a transfer device that retrieves the electronic mail and the song data attached to the mail from the storage device, and transfers the electronic mail and the song data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the notifying device, and the receiving terminal comprises a second receiving device that receives the electronic mail which is transferred from the communication terminal, and to which the song data comprising musical tone control information is attached, an opening device that opens the received electronic mail, and a reproducing device that automatically reproduces the song data attached to the electronic mail when the electronic mail is opened by the opening device.
[0026] To attain the object, according to a sixth aspect of the invention, there is provided an electronic mail system including a communication line, and at least one transmitting terminal, at least one receiving terminal, and at least one communication terminal connected to each other through the communication line, the communication terminal receiving, through the communication line, an electronic mail sent by the transmitting terminal and transferring the received electronic mail to the receiving terminal corresponding to an address of the electronic mail, wherein the transmitting terminal comprises a transmitting device that transmits a request for delivery of the electronic mail to the receiving terminal corresponding to the address of the electronic mail, to the communication terminal, the communication terminal comprises a first storage device that stores a plurality of kinds of ornamental data that ornament the electronic mail sent by the transmitting terminal, and a plurality of kinds of song data attached to the electronic mail and comprising musical tone control information, a presenting device that, in response to the request for delivery of the electronic mail from the transmitting terminal, presents the plurality of kinds of ornamental data and the plurality of kinds of song data stored in the first storage device, to the transmitting terminal, so that the transmitting terminal can select a combination of ornamental data and song data from the plurality of kinds of ornamental data and song data, and designate the combination as electronic mail data, a second storage device that retrieves the electronic mail data from the first storage device and stores the retrieved data, when the transmitting terminal requests the communication terminal to send the combination of ornamental data and song data selected and designated as the electronic mail data, to the receiving terminal, a notifying device that notifies the receiving terminal of receipt of the electronic mail when the electronic mail data is stored in the second storage device in response to the request from the transmitting terminal for sending the electronic mail, and a transfer device that retrieves the electronic mail data from the second storage device, and transfers the data to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by the notifying device, and the receiving terminal comprises a receiving device that receives the electronic mail which is transferred from the communication terminal, and to which the song data comprising musical tone control information is attached, an opening device that opens the received electronic mail, and a reproducing device that automatically reproduces the song data attached to the electronic mail when the electronic mail is opened by the opening device.
[0027] The transmitting terminal and the receiving terminal according to the present invention may each comprise one of a general purpose computer, a portable communication terminal of a wireless communication type, and a portable communication terminal of a wire communication type.
[0028] The above and other objects, features and advantages of the invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] [0029]FIG. 1 is a block diagram schematically showing the construction of a transmitting terminal that constitutes an electronic mail system according to a first embodiment of the invention;
[0030] [0030]FIG. 2 is a flowchart showing a flow of control operations to be performed by the transmitting terminal, a server computer and a receiving terminal that constitute the electronic mail system of the first embodiment;
[0031] [0031]FIG. 3 is a view showing one example of electronic mail data and a playback button displayed at a step S 9 of the flowchart of FIG. 2;
[0032] [0032]FIG. 4 is a flowchart showing a flow of control operations performed by a transmitting terminal, a server computer, and a receiving terminal that constitute an electronic mail system according to a second embodiment of the invention;
[0033] [0033]FIG. 5 is a view showing, by way of example, a set of samples of electronic mail data displayed on a display device on the side of the transmitting terminal that constitutes the electronic mail system of the second embodiment;
[0034] [0034]FIG. 6 is a schematic view showing the construction of an electronic mail system according to a third embodiment of the invention;
[0035] [0035]FIG. 7 is a block diagram schematically showing the construction of one of two portable communication terminals appearing in FIG. 6;
[0036] [0036]FIG. 8A is a view showing an example of the portable communication terminal;
[0037] [0037]FIG. 8B is a view showing another example of the portable communication terminal; and
[0038] [0038]FIG. 8C is a view showing a further example of the portable communication terminal.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0039] The invention will NOW be described in detail with reference to the drawings showing preferred embodiments thereof.
[0040] An electronic mail system according to a first embodiment of the invention is comprised of a transmitting terminal that sends an electronic mail, a server computer (communication terminal) that stores the electronic mail sent by the transmitting terminal in a storage device, and delivers the mail to an addressee of the mail, and a receiving terminal as the addressee that receives the electronic mail delivered by the server computer. Each of these components, i.e., the transmitting and receiving terminals and server computer, may be formed by a general purpose computer, such as a personal computer or a work station. Needless to say, the functions of the transmitting terminal and receiving terminal are not fixedly determined, but may be changed or switched as desired. For example, the receiving terminal may serve as a transmitting terminal when it sends out an electronic mail.
[0041] [0041]FIG. 1 schematically shows the construction of the transmitting terminal, namely, general purpose computer, that constitutes the electronic mail system of the present embodiment.
[0042] As shown in FIG. 1, the transmitting terminal of the present embodiment includes a keyboard 1 mainly used for entering character information, a mouse 2 serving as a pointing device, a key operation detecting circuit 3 that detects an operated state of each key on the keyboard 1 , and a mouse operation detecting circuit 4 that detects an operated state of the mouse 2 . The transmitting terminal also includes a CPU 5 that governs control of the whole apparatus, a ROM 6 that stores control programs to be executed by the CPU 5 , table data, and so forth, a RAM 7 that temporarily stores performance data, various input information, results of computation, and others, a timer 8 that counts interrupt time for timer interrupt processing, and various sorts of time or durations, and a display device 9 that displays various information, and includes, for example, a large-sized liquid crystal display (LCD) or a CRT (cathode ray tube) display, and light emitting diodes (LED). The transmitting terminal further includes a floppy disc drive (FDD) 10 for driving a floppy disc (FD) 20 as one type of storage medium, a hard disc drive (HDD) 11 for driving a hard disc (not shown) that stores various application programs including the above-indicated control programs, various data, and so on, a CD-ROM drive (CD-ROMD) 12 for driving a compact disc read-only memory (CD-ROM) 21 that stores various application programs including the control programs, various data, and so on. In the transmitting terminal are also included a MIDI interface (I/F) 13 that receives MIDI signals from the outside of the computer (external apparatus), and generates or outputs MIDI signals to the outside, a communication interface (I/F) 14 that sends and receives data to and from a server computer 102 or other client computer (receiving terminal in this embodiment) 103 , a tone generator circuit 15 that converts performance data entered through the MIDI I/F 13 or communication I/F 14 , or preset performance data, into musical tone signals, an effect circuit 16 that gives various effects to the musical tone signals received from the tone generator circuit 15 , and a sound system 17 composed of a DAC (digital-to-analog converter), an amplifier, a sound speaker, etc. that converts the musical tone signals received from the effect circuit 16 , into sound.
[0043] The component elements 3 - 16 described above are connected to each other through a bus 18 , and the timer 8 is connected to the CPU 5 . Also, other MIDI equipment 100 is connected to the MIDI I/F 13 , and a communication network 101 is connected to the communication I/F 14 . Further, the effect circuit 16 is connected to the tone generator circuit 15 , and the sound system 17 is connected to the effect circuit 16 .
[0044] The hard disc mounted in the hard disc drive (HDD) 11 is able to store control programs to be executed by the CPU 5 , as described above. Where a desired control program is not stored in the ROM 6 , the control program is stored in the hard disc, and the RAM 7 reads the control program so as to cause the CPU 5 to perform substantially the same operations as in the case where the control program is stored in the ROM 6 . This arrangement makes it easy to add new control programs, and upgrade versions of the programs.
[0045] Control programs and various data read from the CD-ROM 21 in the CD-ROM drive 12 are stored in the hard disc of the HDD 11 . This arrangement makes it easy to install new control programs and upgrade versions of the programs. Various types of external storage devices, other than the CD-ROM drive 12 , that use various forms of media may also be provided. One example of such storage devices is a magneto-optical disc (MO) device.
[0046] As described above, the communication I/F 14 is connected to the communication network 101 , which may be a LAN (local are network), Internet, and a telephone line, for example, to be connected to the server computer 102 or other client computer 103 , through the communication network 101 . Where a certain program or certain type of parameters are not stored in the hard disk within the HDD 11 , the communication I/F 14 is used to download the program or parameters from the server computer 102 . A client computer (i.e., transmitting terminal and receiving terminal in the present embodiment) sends a command to the server computer 102 through the communication I/F 14 and communication network 101 , to request downloading of the desired program or parameters. Upon receipt of the command, the server computer 102 delivers the requested program or parameters to the client computer via the communication network 101 , and the client computer receives the program or parameters via the communication I/F 14 , and stores the same in the hard disc within the HDD 11 , whereby downloading is completed.
[0047] In addition, the computer as described above may be provided with an interface through which data are directly transmitted and received to and from an external computer, or the like.
[0048] While the electronic mail system of the present embodiment uses only one server computer 102 , which is connected to the transmitting terminal and the receiving terminal, the system may include a plurality of serve computers. For example, if two server computers are used, the system may be constructed such that the transmitting terminal is connected to one of the server computers, and the receiving terminal is connected to the other, while these server computers are connected to each other through a network. It is, however, to be understood that the mail system of the present invention is not limited to this arrangement.
[0049] The other apparatuses that constitute the electronic mail system of the present invention, namely, the server computer and the receiving terminal, are respectively formed by general purpose computers, as described above, and the hardware arrangements of these computers are almost the same as that of the transmitting terminal as described above. However, the apparatuses constituting the mail system may be constructed differently from each other. For example, since the server computer 102 of the present embodiment mainly functions to receive electronic mail data, store the data in a storage device, and deliver the electronic mail data to the receiving terminal, such elements that have auxiliary functions to generate musical tones, namely, the tone generator circuit 15 , effect circuit 16 and sound system 17 , may be eliminated from the server computer 102 . Where the server computer 102 includes the FDD (floppy disc drive) 10 and CD-ROM drive 12 as described above, the transmitting terminal and receiving terminal as client computers may use the FDD 10 and CD-ROM drive 12 in common, and therefore the FDD 10 and CD-ROM drive 12 need not be provided on the side of the transmitting terminal and the receiving terminal.
[0050] Referring next to FIG. 2, there will be described control operations to be performed by the transmitting terminal, server computer 102 and receiving terminal that constitute the electronic mail system constructed as described above.
[0051] At a step S 1 in FIG. 2, the transmitting terminal transmits, in response to a user's command, an electronic mail to which song data (prepared by the user) formed of musical tone control information is attached, to the receiving terminal, namely, to the address of the server computer 102 to which the receiving terminal belongs. The musical tone control information is typically MIDI data, and so it will be limited to MIDI data in the following description. The song data will also be called “MIDI data” if there is no possibility of confusion. In the present embodiment, the electronic mail data is formed of not only character data (text data), but may also include image data in addition to character data. For example, the electronic mail data is prepared in HTML (hypertext markup language), so that the mail data is formed of character data and image data, and the electronic mail data described in HTML is sent to the receiving terminal. Such a system is well known in the art. It is also possible to attach a small quantity of voice data (that is not MIDI data but data obtained by converting a voice signal into digital data) to the electronic mail. In the following, the electronic mail data means data of an electronic mail to which song data or voice data is attached.
[0052] At a step S 2 , the server computer 102 stores electronic mail data received from the transmitting terminal, in an addressee's mail box provided in a storage device (for example, hard disc in the HDD 11 ) of the computer 102 . At a step S 3 , the server computer 102 notifies the addressee or receiving terminal of the receipt of the relevant mail.
[0053] In response to this, the receiving terminal recognizes the notification of the receipt of the mail from the server computer 102 at a step S 4 , and sends a command to the server computer 102 to request the electronic mail data that has been stored in the storage device of the server computer 102 , to be downloaded into the receiving terminal at a step S 5 . Namely, the receiving terminal accesses the server computer 102 to retrieve the received mail.
[0054] The server computer 102 recognizes the request from the receiving terminal at a step S 6 , and downloads the electronic mail data under request, to the receiving terminal at a step S 7 .
[0055] The receiving terminal receives the electronic mail data at a step S 8 , and displays the character data and image data included in the electronic mail data, together with a playback button, on the display device 9 at a step S 9 . At the same time, the receiving terminal automatically reproduces MIDI data contained in the electronic mail data, and transmits the data to the tone generator circuit 15 at a step S 10 . At a step S 11 , the tone generator circuit 15 produces a musical tone signal based on the reproduced data, and transmits the signal to the effect circuit 16 , which in turn adds various effects to the musical tone signal thus produced. The sound system 17 receives the resulting musical tone signal from the effect circuit 16 , and generates corresponding sound.
[0056] In the present embodiment, as described above, when the receiving terminal accesses the server computer 102 to retrieve the electronic mail data, the character data and image data as part of the electronic mail data are displayed on the display device 9 , and the MIDI data is reproduced at the same time. With this arrangement, the receiving terminal is able to immediately reproduce musical sound or voice, without requiring the user to start an application program for opening MIDI data as an attached file and reproducing the opened MIDI data. Thus, the user need not operate the computer to perform operations for reproducing the MIDI data, assuring improved efficiency in the use of the computer.
[0057] [0057]FIG. 3 shows one example of electronic mail data and a display control (including the playback button) that are displayed on the display device 9 at the step S 9 , wherein an electronic mail representing a birthday card is illustrated.
[0058] In the example of FIG. 3, a message portion 91 that says “How are you ?” is displayed based on character data entered by the user of the transmitting terminal, and an image portion 92 that includes characters “Happy birthday” is displayed based on image data prepared by the user. The user of the receiving terminal is supposed to operate a display console 93 for controlling the playback state or mode of the received MIDI data. The display console 93 is comprised of a playback start button 92 to be pushed to start reproduction of the MIDI data, a stop button 93 b for stopping the reproduction, a fast forward button 93 c for fast-forwarding the data, and a rewind button 93 d for re-winding the data. The buttons 93 a - 93 d are generically called “playback button”.
[0059] In the present embodiment in which the electronic mail data is displayed on the display device 9 , and the MIDI data starts being reproduced at the same time, the user is able to control the manner of playing back the MIDI data as he/she wishes, by manipulating the mouse 2 to push a desired one of the buttons 93 a - 93 d on the display console 93 .
[0060] In the present embodiment, since song data attached to the electronic mail is formed of MIDI data whose quantity is usually small, high-quality musical sound or voice represented by the small quantity of data can be transmitted and received along with the electronic mail.
[0061] Next, an electronic mail system according to a second embodiment of the invention will be described. The electronic mail system of the present embodiment is different from that of the first embodiment only in terms of the control processing of each apparatus that constitutes the electronic mail system, and therefore only the control processing will be described, and the hardware structure of each apparatus will not be explained.
[0062] [0062]FIG. 4 shows a flow of control operations to be performed by the transmitting terminal, server computer 102 , and receiving terminal that constitute the electronic mail system of the present embodiment.
[0063] At a step S 21 in FIG. 4, the transmitting terminal sends, in response to a command of the user, a request for delivery of an electronic mail, to a server computer (that will be called “connection server”) to which the transmitting terminal is connected. The connection server receives the request for mail delivery from the transmitting terminal at a step S 22 , and sends samples of electronic mail data stored in a storage device (for example, hard disc in the HDD 11 ) of the connection server, to the transmitting terminal. The samples of electronic mail data may be in the form of image data (reduced images: ornamental data), and data indicating song names (ornamental data) of respective sets of MIDI data. The connection server then causes the display device 9 of the transmitting terminal to display the samples of electronic mail data, and also display a message area that allows entry of a message (step S 22 ).
[0064] [0064]FIG. 5 shows one example of samples of electronic mail data displayed on the display device 9 on the side of the transmitting terminal. In the example of FIG. 5, a plurality of reduced images of image data and a plurality of song names of MIDI data are displayed, along with a message area 95 (in which the user has already entered a message: “How are you ?”).
[0065] Referring back to FIG. 4, the user selects image data and MIDI data which he/she wishes to send to the receiver, from the plurality of reduced images and song names displayed as shown in FIG. 5, and enters a message in the message area 95 at a step S 24 . When the user presses a send button 96 (shown in FIG. 5) provided in the message area 95 , the transmitting terminal requests the connection server to deliver the electronic mail data including the selected image and song and the message entered by the user, to the desired receiver at a step S 25 .
[0066] In response to the request from the transmitting terminal, the connection server stores the requested electronic mail data (including character data, image data and MIDI data) in a receiver's mail box provided in the storage device at a step S 26 . The processing steps following the step S 26 , namely, steps S 27 through S 35 , are similar to the steps S 3 through S 11 of the first embodiment, and therefore will not be described herein.
[0067] In the second embodiment, as described above, song data formed of MIDI data having a small data quantity is attached to the electronic mail, as in the first embodiment. Furthermore, some samples of electronic mail data are available from the connection server, which enables the user to send desired electronic mail data to the receiver, without preparing the electronic mail data, in particular, song data, on his/her own.
[0068] In the above described electronic mail systems according to the first and second embodiments, the transmitting terminal and the receiving terminal are each formed by a general purpose computer such as a personal computer and a work station. The transmitting terminal and the receiving terminal are not limited to this type, but they may be implemented by any type of terminals that can be connected to a general purpose network as typically represented by Internet and a satellite communication.
[0069] [0069]FIG. 6 shows the construction of an electronic mail system according to a third embodiment of the invention. As shown in FIG. 6, the electronic mail system according to this embodiment employs, as a transmitting terminal and a receiving terminal, portable communication terminals as represented by a portable phone and a PHS (personal handyphone system), which have a function of being connected to the server computer 102 as shown in FIG. 1. In FIG. 6, a portable communication terminal 30 on the left side is used as a transmitting terminal, and a portable communication terminal 30 ′ on the right side is used as a receiving terminal. However, this is merely an example, and the portable communication terminals 30 , 30 ′ may be identical in construction and function with each other, and may each be used as both a transmitting terminal and a receiving terminal.
[0070] [0070]FIG. 7 schematically shows the construction of one of the two portable communication terminals 30 , 30 ′ shown in FIG. 6. In FIG. 7, the portable communication terminal 30 according to the present embodiment is comprised of a circuit component group 30 A which constitutes a general portable terminal (i.e. not a special portable terminal that is able to receive electronic mails to which MIDI data are attached and reproduce the MIDI data), and a circuit component group 30 B which implements electronic musical instrument functions (mainly including a function of reproducing the received MIDI data). The two circuit component groups 30 A, 30 B are connected to each other through a communication I/F. The circuit components of the circuit component groups 30 A, 30 B are similar or identical to those shown in FIG. 1 and described before, or known ones, description of which is therefore omitted.
[0071] Although FIG. 7 shows the construction of a portable communication terminal shown in FIG. 6, that is, the construction of an ordinary portable phone or PHS, in which the entire circuit component group 30 A is accommodated, the construction of the portable communication terminal is not limited to this type, but alternatively it may be one of forms shown in FIGS. 8A to 8 C. That is, the construction of the portable communication terminal may be a type that an ordinary portable terminal constituted by the circuit component group 30 A and a portable musical instrument constituted by the circuit component group 30 B are connected to each other by a connection cable, as shown in FIG. 8A, a type that an ordinary portable terminal constituted by the circuit component group 30 A and a portable musical instrument constituted by the circuit component group 30 B are connected together in a manner being disconnectable from each other by an exclusive connecting mechanism, as shown in FIG. 8B, or a type that the circuit component group 30 A is accommodated within a portable musical instrument constituted by the circuit component group 30 B, as shown in FIG. 8C. Thus, the portable communication terminal according to the invention may have any construction insofar as the circuit component group 30 A and the circuit component group 30 B are connected to each other by a communication I/F. The communication I/F may be of any construction insofar as it is adapted to send and receive data of MIDI format between the circuit component group 30 A and the circuit component group 30 B.
[0072] By operating the electronic mail system thus constructed so as to perform control operations as described before with reference to FIG. 2 or FIG. 4, control operations similar or identical to the control operations according to the first or second embodiment can be performed using portable communication terminals in place of a general purpose computer.
[0073] Although the portable communication terminals employed by the present embodiment are of a wireless communication type, portable communication terminals according to the present invention are not limited to this type, but they may be of a wire communication type which can be connected to an analog public network, a digital public network (ISDN), or a local area network (LAN).
[0074] The object of the present invention may also be attained by supplying a system or apparatus with a storage medium in which a software program that achieves the function of each of the illustrated embodiments is stored, and causing a computer (CPU 5 or MPU) of the system or apparatus to read and execute the program stored in the storage medium.
[0075] In this case, the program read out from the storage medium serves by itself to realize the novel function of the present invention, and thus the storage medium storing the program constitutes the present invention.
[0076] The storage medium for supplying such a program to the system or apparatus may be in the form of a hard disc mounted in the HDD 11 , CD-ROM 21 , MO, MD, floppy disk 20 , CD-R (CD-Recordable), magnetic tape, nonvolatile memory card, or ROM, for example. Also, the program may be supplied from other MIDI equipment 100 , or from the server computer 102 through the communication network 101 .
[0077] Needless to say, the function of each of the illustrated embodiments may be performed not only by executing the program read by the computer, but also by causing OS (operating system) that is operating on the computer, to perform a part or all of actual operations according to the instructions or commands contained in the program.
[0078] Furthermore, the program read out from the storage medium may be written into a memory provided in an expanded board inserted in the computer, or an expanded unit connected to the computer, and a CPU, or the like, provided in the expanded board or expanded unit may perform a part or all of actual operations according to instructions or commands of the program, so as to accomplish the function of each of the illustrated embodiments.
[0079] Although in each of the illustrated embodiments the transmitting terminal or receiving terminal uses the tone generator circuit 15 and effect circuit 16 as shown in FIG. 1, to synthesize musical tones and sound the same, based on song data, alternatively, these functions of musical tone synthesization and sounding may be performed by software means (musical tone synthesis means and effect imparting means) which are realized by executing a program such as a musical tone generating program by the CPU.
[0080] Further, although in each of the illustrated embodiments an electronic mail to which song data formed of MIDI data is attached is transmitted and received, alternatively, tone color data (waveform data, musical tone parameters, and others) may also be attached to the electronic mail and transmitted together therewith in case that the receiving terminal has no designated tone color data stored in a storage device thereof. Furthermore, a musical tone generating program for generating musical tones having designated tone color may be attached to the electronic mail and transmitted together therewith in case that the receiving terminal does not have the program stored in a storage device thereof. In these cases, the receiving terminal may use the tone color data or the program transmitted together with the electronic mail, if required, while it may decline receiving it if not required.
[0081] The present invention is not limited to the above described embodiments, but may be implemented by various combinations of the features of the above described embodiments. Further, many modifications and variations of the invention are possible in the light of the above teachings without departing from the scope of the appended claims.
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An electronic mail system including a communication line, and at least one transmitting terminal, at least one receiving terminal, and at least one communication terminal connected to each other through the communication line, the communication terminal receiving, through the communication line, an electronic mail sent by the transmitting terminal and transferring the received electronic mail to the receiving terminal corresponding to an address of the electronic mail. The transmitting terminal attaches song data comprising musical tone control information, to the electronic mail, and transmits the electronic mail with the song data attached, to the communication terminal, which in turn, stores the received electronic mail in a storage device, notifies the receiving terminal of receipt of the electronic mail, and retrieves the electronic mail and the song data attached to the mail from the storage device, and transfers them to the receiving terminal, when the receiving terminal requests receipt of the electronic mail in response to notification by said notifying device. The receiving terminal opens the received electronic mail, and automatically reproduces the song data attached to the electronic mail.
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BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a new and improved dewatering device for the web-forming or wet section of a papermaking machine.
Generally speaking, the dewatering device for the web-forming or wet section of a papermaking machine according to the present invention is of the type comprising foils or strips or ledges disposed transverse to a predetermined direction of travel of the forming wire or sieve, that is to say, the foils extend in the cross-machine direction. These foils are individually adjustable or else adjustable in groups or sets in the direction of the forming wire. Through the use of force or powering elements for the foils there can be exerted, by means of the foils, a predetermined or desired force or pressure action upon the forming wire, especially for the dewatering and formation of the paper web or sheet formed of fiber stock suspension which is located upon the forming wire.
2. Discussion of the Background and Material Information
Dewatering devices of this type can be constructed, for instance, in the manner disclosed in the commonly assigned German Patent Publication No. 3,929,265, published Mar. 28, 1991. This published German document teaches the possibility of rendering foils individually adjustable, in order to be able to adjust or set their position and to exert a force upon the forming wire as a function of prevailing requirements. Depending upon the operating conditions under which these foils are used, particularly when there are required considerable adjustment distances through which the foils must be moved, it can happen, however, that these foils experience undesired seizing and bending. One of the main reasons that this occurs is attributable to the fact that frictional forces arise at the location where the foils come into contact with the traveling forming wire. By virtue of the prevailing lever action these frictional forces produce a moment which must be taken up by the guides of the foil adjustment mechanism, and hence, there can result the aforenoted foil seizure or binding and foil bending. Since at this location of the papermaking machine high precision settings and regulation operations must be carried out, appreciable drawbacks arise during the manufacture of high-quality paper sheets or webs when the foil adjustment mechanism operates inaccurately.
Other dewatering devices are also known in this technology wherein a multiplicity of foils or ledges are mounted at a frame and this frame can be pressed against the forming wire of the papermaking machine through the use of appropriate force or powering elements. While such systems can be rather easily constructed such that the foils do not seize or clamp, nonetheless there is here not possible individual adjustment or setting of the foils.
SUMMARY OF THE INVENTION
Therefore, with the foregoing in mind, it is a primary object of the present invention to provide an improved dewatering device for the web-forming or wet section of a papermaking machine which is not afflicted with the aforementioned shortcomings and drawbacks of the prior art.
Another and more specific object of the present invention aims at the provision of an improved dewatering device for the web-forming or wet section of a papermaking machine by means of which there can be undertaken an exceedingly accurate individual adjustment of the foils as well as a precise adjustment of such foils throughout their required adjustment path, so that such foils do not tend to clamp or seize.
Still a further noteworthy object of the present invention concerns the provision of an improved dewatering device for the web-forming or wet section of a papermaking machine which is quite economical to fabricate, not readily subject to breakdown or malfunction, extremely reliable in operation, and enables formation of a high-quality paper web or sheet at the web-forming section of the papermaking machine in an efficient and accurate manner.
Now in order to implement these and still further objects of the present invention, which will become more readily apparent as the description proceeds, the dewatering device for the web-forming or wet section of a papermaking machine of the present development is manifested, among other things, by the features that the force elements are constructed and positioned such that these force elements can produce additional moments capable of counteracting tilting moments exerted by the frictional forces present between the foils and the forming wire.
By virtue of the foregoing, there is achieved the beneficial result that the unavoidable tilting moments are introduced into the force elements, so that such force elements not only generate the required contact or pressing forces for the foils or strips at the forming wire, but when constructing the dewatering device according to the teachings of the present invention, these force elements can take up such tilting moments. As a result, there is avoided the clamping or seizing of the foil guides which enable movement of the foils towards and away from the forming wire. The force elements can be constructed such that sufficient space is available therebetween in order to be able to rapidly remove the water collected at this location and with minimum hinderance.
It is here noted that the present invention envisages that the moment which counteracts the tilting moment can be produced by adjustable force or powering elements successively or tandemly arranged in the direction of travel of the forming wire.
According to a further aspect, the present invention contemplates that a plurality of the foils secured at supports or support members extending transverse to the direction of travel of the forming wire are assembled together into a group or set. These supports are displaceably guided at guide members. At the region of at least one of the guide members there is provided an abutment or stop or support element, which is movable in the direction of the forming wire, for the forces acting in the direction of travel of the forming wire. The supports are mechanically interconnected by rigid coupling or connection elements. These supports and coupling or connection elements are constructed such that they provide an adequate amount of free space for the throughflow of water passing through the forming wire.
Still further, the supports or support members can be mechanically interconnected by coupling or connection elements provided with pivots or hinges. Here too, these supports and coupling or connection elements are constructed such that they provide an adequate amount of free space for the throughflow of water passing through the forming wire.
A group or set of conjointly adjustable or settable foils can comprise, for example, two, three or four foils. Therefore, due to the grouping or assembly together of a relatively small number of individual foils there are present sufficient possibilities for the individual adjustment of the individual foils towards the forming wire.
The present invention further proposes that at least one force element comprises a force-generating source or device filled or fillable with a suitable pressurized fluid medium, such as water or air. The force applied by the force-generating source in the direction of the forming wire can be adjusted or regulated by the pressurized fluid medium.
The force-generating sources can be constructed and arranged such that the forces applied by the same are directed towards the forming wire and opposite to the direction of travel of the forming wire, so that the forces effective in the travel direction of the forming wire are at least partially taken up.
Furthermore, the cross-sectional configuration of the force-generating elements can be of elongated expanse or extended shape in the direction of travel of the forming wire.
It is possible, according to a further feature, to apply the moment which counteracts the tilting moment by relatively low-friction guides or guide elements successively arranged in the direction of travel of the forming wire.
Moreover, the force element of an associated foil or forming foil can comprise a force-generating source arranged in a compartment or chamber. This force source acts upon a displacement or movable element guided in an associated transverse support or support member. This displacement element carries the foil and is shiftable in the direction of the forming wire. Moreover, a friction-reducing medium can be provided between a wall of the compartment or chamber and the displacement element. In this arrangement, the compartment or chamber can be advantageously supplied with a suitable fluid medium, especially water, for flushing the associated foil.
As an alternative arrangement, each force element of an associated foil or forming foil can comprise a compartment or chamber which is filled or fillable with a suitable pressurized fluid medium. The cross-section of such compartment or chamber can possess an extended or prolonged expanse in the direction of travel of the forming wire. The displacement element is inserted into the compartment or chamber. This displacement element carries the associated foil, is guided in a transverse support or support member, and is shiftable in the direction of the forming wire. Moreover, such displacement element closes the compartment or chamber. Also, in this arrangement, the compartment or chamber can be supplied with a suitable fluid medium, again especially water, for flushing the associated foil.
As to a further aspect of the present invention, the rear wall of the force-generating source, as viewed with respect to the direction of travel of the forming wire, can be constructed such that, during operation of the dewatering device, this rear wall produces a stronger force in the direction of the forming wire as other more forwardly situated regions of such force-generating source.
It is furthermore contemplated for the force element of a foil or forming foil to be provided with at least two force-generating sources which are capable of producing forces of different magnitude. The applied force of each of these at least two force-generating sources is in the direction of the forming wire. Moreover, these at least two force-generating sources are successively arranged as viewed with respect to the direction of travel of the forming wire.
As a further possibility, it is contemplated that when there are used at least two force-generating sources for each foil or forming foil, one of these force-generating sources has a direction of the applied force which does not extend towards or not directly towards the forming wire and can be shifted in the direction of the forming wire. Still further, one of these force-generating sources can have a direction of the applied force which does not extend towards the forming wire and can be freely adjusted in the direction of the forming wire.
It is also possible for the force element of a foil to be provided with only one force-generating source, the applied force of such single force-generating source is in the direction of the forming wire and, as viewed in the direction of travel of the forming wire, is located behind or downstream of the point of application of the force of the associated foil.
Still further, the counteracting moment can be produced by a lever extending in or opposite to the direction of travel of the forming wire, the foil or foils being secured at such lever, and force-generating sources act upon the lever.
According to a still further construction, the counteracting moment can be produced by force elements operatively engaging with a frame member provided with a group of the foils, and at least two of these force elements are arranged in succession as viewed with respect to the direction of travel of the forming wire.
With reference to a still further possible embodiment, the counteracting moment can be produced by force elements operatively engaging with a frame member provided with a group of the foils and pivotable levers. In this arrangement, at least two of these pivotable levers are arranged in succession as viewed with respect to the direction of travel of the forming wire, and such pivotable levers allow for a substantially parallel movement between the frame member and the stand of the papermaking machine in the and opposite to the direction of travel of the forming wire.
According to a further aspect, the present invention contemplates that there are provided at least two supports or support members arranged in succession with respect to the direction of travel of the forming wire and which extend transverse to such direction of travel of the forming wire. At each such support or support member there is secured at least one foil. These supports are displaceably guided at guide members in the direction of the forming wire. At the region of at least one of the guide members there is provided an abutment or stop element, which is movable in the direction of the forming wire, for the forces acting in the direction of travel of the forming wire. Rigidly mounted levers are provided for the supports or support members, and such rigidly mounted levers extend substantially perpendicular to the direction of movement of these supports or support members. Between the rigidly mounted levers there is arranged at least one force-generating component or part, and such rigidly mounted levers are directed towards one another and offset from one another with respect to the direction of movement or displacement of the supports or support members.
Regarding the just-mentioned at least one force-generating component or part such can comprise a spring bellows by means of which, by virtue of different expansion thereof, there can be produced a predetermined or desired adjustable force in the direction of movement or displacement of the supports or support members.
Additionally, the present invention further contemplates to leave sufficient space or distance between the individual force elements such that the water passing through the forming wire can be withdrawn between the force elements at least partially throughout the entire cross-machine direction of the papermaking machine.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be better understood and objects other than those set forth above, will become apparent when consideration is given to the following detailed description thereof. Such description makes reference to the annexed drawings wherein throughout the various figures of the drawings there have been generally used the same reference numerals to denote the same or analogous elements or components, and wherein:
FIG. 1 is a fragmentary partial sectional view of a dewatering device for the web-forming or wet section of a papermaking machine constructed according to the present invention; and
FIGS. 2 to 23 depict in respective fragmentary partial sectional views different exemplary embodiments of dewatering devices for the web-forming or wet section of a papermaking machine constructed according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Describing now the drawings, it is to be understood that only enough of the construction of the different exemplary embodiments of dewatering devices DD for the web-forming or wet section WF of a papermaking machine, merely generally represented by reference character PM, have been depicted therein, in order to simplify the illustration, as needed for those skilled in the art to readily understand the underlying principles and concepts of the present invention.
Turning now to the exemplary embodiment of FIG. 1, there is depicted therein a group of, for instance, three foils or strips or ledges 1 arranged beneath a travelling forming wire or sieve 3 moving through the web- or sheet-forming section WF of the papermaking machine PM. Of course, there can be provided a lesser or greater number of foils 1 in the group, such as, for example, two or four such foils 1 (see, for example, FIGS. 2 to 4 and 15). Upon the forming wire 3 there is supported a fiber layer or ply 4 from which there is formed a paper web or sheet, generally represented by reference character PW (see FIG. 2).
These three foils or forming foils 1 are pressed against the forming wire 3 by three associated force elements or foil powering elements or force means 2. These three force elements 2 are supported upon a frame or frame member 20 of the papermaking machine PM. Force sources or force-generating sources 8 are located within the related force or powering element 2. In the embodiment under consideration each such force source or force-generating source 8 may comprise, for instance, a hose or tube member 8a or equivalent structure filled or fillable with a suitable pressurized medium, for instance, water or air, which exerts the requisite force or pressure. The individual successively arranged foils 1 secured to foil supports or carriers 5 are here mechanically coupled with one another by, for example, rigid coupling or connection elements 5', which may be constituted, for example, by struts or webs 5a or equivalent connector structure. These coupling or connection elements 5' are spaced sufficiently apart from one another in the cross-machine direction to allow the water expressed through the forming wire 3 to be removed without hinderance.
Furthermore, it will be seen that the foil supports or carriers 5 are displaceably guided at guide elements or guides 6 for movement in the direction of or substantially perpendicular to the forming wire 3. At the movable foil supports or carriers 5 there are provided abutments or stop elements 7 extending in the cross-machine direction, for instance, substantially through the same distance as the length of the related foil 1 for taking up forces effective in the direction of travel or movement A of the forming wire 3. Since the abutments or stop elements 7 are here shown secured to the movable foil supports or carriers 5, such abutments or stop elements 7 are also movable in the direction of the forming wire 3.
During operation of the dewatering device DD, frictional forces present between the foils 1 and the forming wire 3 produce tilting moments, as indicated, for instance, in FIGS. 21 and 23 by reference character B, which are counteracted by the force elements or force means 2 which produce additional moments opposing or counteracting these tilting moments B.
FIGS. 2 and 3 respectively illustrate similar dewatering devices DD like the embodiment of FIG. 1, wherein, here however, only two foils 1 are grouped together into a group or set. The force sources or force-generating sources 8 (FIG. 2) and 8' (FIG. 3) of the related force elements or foil powering elements 2, are constructed, for example, either as hose or tube members 8a (see FIG. 2) or bellows 8b (FIG. 3), which can be or are filled with a suitable pressurized medium as previously explained. In the embodiment of FIG. 2 there has been represented by the arrows 100 the water which is removed beneath the travelling forming wire 3 during operation of the dewatering device DD, whereas for purposes of simplification of the drawings such downward water removal has not been particularly illustrated in the other embodiments.
With reference now to the modified construction of dewatering device DD shown in FIG. 4, the force which is effective in the direction of travel A of the forming wire 3, can be taken up by an additional force source or force-generating source 8" which can apply forces both in the direction of or substantially perpendicular to the forming wire 3 as well as in the direction opposite to the direction of travel A of such forming wire 3. The aforementioned force source or force-generating source 8" in conjunction with the force source or force-generating source 8 located thereafter or downstream, as viewed with respect to the direction of travel A of the forming wire 3, can generate the counteracting moment.
The embodiments of FIGS. 5 and 6 depict, apart from the force sources or force-generating sources 8 for producing the forces required in the direction of the forming wire 3, respective additional force elements 21 and 22 which are effective in the opposite direction and by virtue of their spaced apart position, as viewed in the direction of travel A of the forming wire 3, can produce a moment. As a result, there is possible a specific adjustment of the angle of attack or contact angle of the foil 1 with respect to the forming wire 3.
Continuing, and with reference to the various further possible embodiments of dewatering devices DD respectively depicted in FIGS. 7, 8 and 8a, the desired angle of attack of the foil 1 with respect to the forming wire 3 and the required moment, can be realized by means of the depicted force sources or force-generating sources 10 and 15. This can be either accomplished by, as in FIG. 7, prolonging or extending the expanse of the single force source 10 in the direction of travel A of the forming wire 3, or, as shown in FIG. 8, through the use of two successively or tandemly arranged force sources 15 as viewed with respect to the direction of travel A of the forming wire 3, or still further, according to the embodiment of FIG. 8a, by means of a single force source 15 whose point of force application or point of action is located offset behind or downstream of the point of force application at the foil 1 as viewed with respect to the direction of travel A of the forming wire 3. Moreover, the embodiment of FIG. 8 affords a further advantage when both of the tandemly or successively arranged force sources 15 are supplied with different fluid medium pressures. As a result, the moment can be intentionally controlled and, when necessary, there can be produced a different angle between the foil 1 and the forming wire 3.
In the embodiment of FIG. 9 there is provided for solving the objectives of the present invention, a force source 9 having a rear wall 14 structured such that, during operation of the dewatering device DD, this rear wall 14 produces a more intensive force in the direction of the forming wire 3 in relation to the force produced by the more forwardly situated region or regions 14a of such force source 9. This rear wall 14 can have, as shown, a bellows-like or pleated structure.
FIG. 10 depicts a further exemplary embodiment of dewatering device DD, wherein one of the force sources 16 is arranged between a leg 5a of the support or support member 5 and a slide 6a of the associated guide or guide member 5. This force source 16 has a force action which is not directed towards the forming wire 3 and the point of application of the force can be shifted in the direction of the forming wire 3, and thus, there can be adjusted the moment.
In contrast thereto, in the further embodiment of dewatering device DD depicted in FIG. 11, the force source 16 freely adjusts its position with respect to the forming wire 3.
Regarding the embodiment of FIG. 12 such constitutes to a certain extent an improvement upon the embodiments of dewatering devices DD illustrated in FIGS. 10 and 11. Furthermore, this arrangement affords the possibility of adjusting or setting the angle between the top of the foil 1 and the forming wire 3. This is specifically possible by the provision of additional or supplementary force sources 17 which, as viewed in the direction of travel A of the forming wire 3, are arranged offset or positionally shifted with respect to the other force sources 8 and 16.
As to the force elements or foil powering elements 2 depicted in the various embodiments of FIGS. 13, 13a, 13b, 14, and 14a, the foils or strips 1 can be adjusted by displacement of displacement or movable elements 12 in the direction of the forming wire 3. These displacement elements 12 are guided in transverse support members 21 which essentially extend throughout the width of the papermaking machine PM, that is, in the cross-machine direction. In the embodiment of FIG. 13 there is used as the force-generating element a deformable hose or tube member 11 filled with a suitable pressurized fluid medium as previously explained. The chamber or compartment 102 housing the hose or tube member 11 flow communicates with an infeed or delivery line 104 which supplies a suitable fluid medium, such as water to this chamber or compartment 102 which lubricates the guide surfaces or walls 106 and 108 between the transverse support member 21 and the displacement element 12 so as to reduce the frictional forces. The infed water then can pass in the direction of the associated foil 1 between the outer wall 108 of the displacement or movable element 12 and the inner wall 106 of the chamber or compartment 102 and contacts such foil 1 for flushing and cleaning the same, as indicated by the arrows 110.
In the respective modified constructions of FIGS. 13a and 13b, friction reducing elements or low-friction guides 112, such as small roller-like elements formed of or coated with a low-friction material, such as "Teflon", can be successively arranged in the direction of travel A of the forming wire 3 between the outer wall 108 of the displacement or movable element 12 and the inner wall 106 of the chamber or compartment 102 housing the hoses 11 in order to promote the relative movement between the displacement or movable element 12 and the transverse support member 21 and for applying the moment which counteracts the tilting moment. 20 In the further embodiment of FIGS. 14 and 14a, there is used as the force-generating element a pressure chamber or compartment 11' flow communicating with a pressurized fluid medium infeed line or conduit 114. The guide surfaces or walls 106 and 108 between the transverse support member 21 and the displacement element 12, respectively, are lubricated by a suitable fluid medium which reduces frictional forces. For this purpose, it is conceivable to use water, supplied by the infeed or delivery line or conduit 114 to the pressure chamber or compartment 11' and which effluxes in a desired quantity from the guide gap or space 116 between the transverse support member 21 and the displacement element 12, and here also can be used for cleaning and flushing the related foil 1. FIG. 14 shows the rest position of the foil 1 and FIG. 14a its inclined position, during operation, when there is exerted the tilting moment. To facilitate sliding movement between the displacement or movable element 12 and the inner wall 106 of the transverse support member 21 bounding the pressure chamber or compartment 11' such inner wall can be coated with a low-friction material, such as "Teflon", as generally indicated by reference numeral 118.
Further possible constructions of dewatering devices DD have been depicted in FIGS. 15 and 16, wherein a plurality of foils 1 are either mounted upon a frame member 19 supported at successively arranged force sources or force-generating sources 8' (FIG. 15) or upon lever members or levers 18 provided with hinges or pivots 18a and force sources or force-generating sources 8' (FIG. 16). These lever members or levers 18 extend in or opposite to the direction of travel A of the forming wire 3.
As depicted in the respective embodiments of FIGS. 17, 18 and 19, the movement and exact guidance of the foils 1 also can be accomplished by means of a frame member 19 guided in hinges or pivots 24a for movement essentially parallel to the forming wire 3. Furthermore, force sources or force-generating sources 8' which produce forces directed towards the forming wire 3 and successively arranged pivot levers or lever members 24 can take up the forces exerted in the direction of travel A of the forming wire 3 and the moments and can introduce such into the stand or framing 22 of the papermaking machine PM.
FIG. 20 illustrates that it is possible to devise a dewatering device DD capable of fulfilling the objectives of the present invention if the force elements 2 are positioned at an inclination. By virtue of these measures there can be taken up or absorbed the frictional forces transmitted to the foils 1 and moments resulting from such frictional forces.
For the embodiment of FIG. 20, there can be used an arrangement similar to that considered with regard to FIG. 13, wherein each force element 2 of an associated foil 1 can comprise a force source 8 installed in a chamber or compartment 120. This force source 8 acts upon an associated displacement element 12 guided in the related transverse support or support member 21. This displacement element 12 carries the foil 1 and is shiftable in the direction of the forming wire 3. Moreover, here also, a suitable friction-reducing medium can be employed between the wall of the chamber or compartment 120 and the displacement element 11. As an alternative construction, there can be used for the embodiment of FIG. 20, constructions and arrangements of the force elements 2 like those previously considered with regard to the heretofore described embodiments of FIGS. 13a, 13b, 14a and 14b.
As illustrated in the modified embodiment of FIG. 21, the coupling or connection elements 5' located between the foil supports 5, also can be provided with a pivot or hinge structure 5". Notwithstanding the frictional moments B exerted at the foils or forming foils 1 during operation of the dewatering device DD, there is thus rendered possible a stable guiding of the foil supports 5 free of any binding or seizure since the frictional force moments produce counteracting forces at the pivot or hinge structure 5'.
With respect to the construction of dewatering device DD as depicted in FIG. 22, the foils 1 can be arranged, for instance, upon a frame or frame member 19 upon which act force sources 8'. Just like for the embodiments of FIGS. 13, 13a and 13b for instance, there can be here also provided an arrangement where each of the force elements or force means 2 of an associated foil 1 comprises displacement or movable elements 12 movable in the direction of the forming wire 3. These displacement elements 12 are guided in associated transverse support members 21 and there can be used as force source or force-generating source 13 for each of these force elements or force means 2 a deformable hose or tube member 8a filled with a suitable pressurized fluid medium as previously explained. As a result, with an approximately linearly increasing contact or pressing force in the direction of travel A of the forming wire 3, that is, with a greater force present in the supporting force sources 8' situated behind the frame 19, the frame 19 is adjusted at an acute angle with respect to the forming wire 3, as shown. The thus resulting unequal spacing between the frame 19 and the forming wire 3 can be easily compensated by the force sources 13.
With reference now made to the embodiment of FIG. 23, it is indicated that such arrangement enables an independent adjustment or setting of neighboring foils 1, since it is possible, through the use of a force-generating element 26, to produce a force which is essentially independent of distance. There are provided rigidly mounted levers 25 and 25' which extend substantially perpendicular to the direction of movement of associated supports or support members 5. Between such rigidly mounted levers 25 and 25' there is arranged the force-generating component or part 26. Furthermore, these rigidly mounted levers 25 and 25' are directed towards one another and are offset from one another with respect to the direction of movement or displacement of the supports or support members 5. Due to the provision of spaced apart levers or lever members 25 and 25' which are rigidly connected with neighboring foil supports or support members 5, this distance-independent force produces the desired supporting or counteracting moment or torque and at the same time allows for a change in position of the related foil 1 relative to the forming wire 3. Such measure can be beneficial in the here exaggerated depicted case of foil wear, but also in order to be able to provide a finer regulation of the contact or pressing force.
Regarding the just-mentioned at least one force-generating component or part 26 such can comprise a spring bellows 26a by means of which, by virtue of different expansion thereof, there can be produced a predetermined or desired adjustable force in the direction of movement or displacement of the supports or support members 5.
It is here importantly mentioned that even though for explanatory purposes the different embodiments of inventive dewatering device DD have been depicted in conjunction with foils or strips or ledges arranged substantially in horizontal direction in succession or tandem in the direction of travel A of the forming wire 3, other arrangements are readily possible, such as inclined or vertical, provided that the forming wire 3 is suitably guided. Moreover, it is to be appreciated that various features of the individual embodiments can be advantageously combined to create still further constructions of dewatering devices without departing from the spirit and scope of the present invention.
While there are shown and described present preferred embodiments of the invention, it is distinctly to be understood the invention is not limited thereto, but may be otherwise variously embodied and practiced within the scope of the following claims.
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A dewatering device for the web-forming or wet section of a papermaking machine comprises foils arranged transverse to a forming wire, that is to say, extend in the cross-machine direction. Force or powering elements act upon the foils so as to exert a force or pressure upon the forming wire, and thus, bring about dewatering and sheet formation of a layer of fiber stock suspension reposing upon the forming wire. The force elements are constructed and positioned such that additional moments are generated which counteract tilting moments produced by the frictional force present between the foils and the forming wire. In certain arrangements, the force elements also can be interconnected with one another.
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CROSS REFERENCE TO RELATED APPLICATIQN
This application is a continuation-in-part of application Ser. No. 08/105,114 filed Aug. 12, 1993, now U.S. Pat. No. 5,429,061.
FIELD OF THE INVENTION
The present invention relates to field marking.
BACKGROUND
In the spraying of agricultural chemicals, it is important to minimize the double spraying of crops due to overlap off sprayer passes and also to eliminate any gaps between the sprayer passes. To enable this, systems have been developed for dropping markers, for example patches of foam, paper or chalk on a field to designate the edge of a sprayer pass. Other systems use discs that leave a mark on the ground. These systems are all subject to visibility problems, especially where spraying is being done at night, the most common time for such work because of reduced winds.
Another system which has been developed is the "tramline" system that leaves unseeded rows at appropriate intervals along a field to accommodate the tires of a tractor. While this system is effective in that it provides a reliable, highly visible and easy to follow marking in the field, the mechanisms used to achieve the desired result generally include rather complex clutching mechanisms on the drive shaft for the conventional seed flute. It may require a permanent modification of the seed metering drive shaft.
The present invention is concerned with a field marking system that is easily and simply retro-fit into any common seed drill and involves no permanent modification of the seeder.
SUMMARY
According to one aspect of the present invention there is provided 1.
A valve assembly for use with a seed box of a seeder to control seed flow therethrough, the valve assembly comprising:
base means having an outlet aperture therein, the base means comprising a bottom wall and a cover;
slide valve means including a valve plate mounted between the bottom wall and the cover for sliding movement between an open position adjacent the aperture and a closed position extending across the aperture,
motor means remote from the base;
valve plate translating means for moving the valve plate between the open and closed positions, including linkage means connecting the motor and the valve plate for moving the valve plate between the open and closed positions in response to operation of the motor; and
control means for controlling operation of the motor means whereby seed may selectively be omitted from selected rows during planting so as to mark a field.
The valve controlling the seed delivery is inside the seed box, using a simple, easily installed, internal valve unit.
Preferably, the control system may provide automatic control so that a marker row will automatically be omitted after a predetermined number of passes. For manual control, the control mechanism preferably has a display showing the number of passes completed since the last marker row or the number of passes to complete before the next marker row is to be made.
According to another aspect of the present invention there is provided, in a seeder having a transversely elongate seed box with a bottom wall having a plurality of seed dispensing openings spaced therealong, and seed metering and planting means below the seed dispensing openings for planting seed at a predetermined, metered rate, the improvement comprising valve means for selectively dosing one of the seed dispensing openings, means mounting the valve means on the bottom wall, inside the seed box, the valve means including a valve plate, means mounting the valve plate for movement between a dosed position extending across said one of the seed dispensing openings and an open position located beside the said one of the seed dispensing openings, and motor means for moving the valve plate between the dosed and open positions.
Preferably the valve is inside the grain box and the motor outside, providing minimum obstruction in the seeder box. The assembly may be substantially universal and suited to be mounted in almost any manufacturer's seed box. A base plate mounted permanently in the seed box carries clamps for clamping the valve properly into the seed box.
BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings, which illustrate an exemplary embodiment of the present invention:
FIG. 1 is a plan view schematically illustrating the theory of operation;
FIG. 2 is a plan view of a seed box with a valve unit installed;
FIG. 3 is a sectional view along line 3--3 of FIG. 2;
FIG. 4 is an isometric view of the valve unit;
FIG. 5 is a plan view of the valve unit with the cover removed;
FIG. 6 is a front view of a control unit;
FIG. 7 is a control unit schematic block diagram;
FIG. 8 is a control schematic;
FIG. 9 is a plan view of an alternative embodiment of the valve unit;
FIG. 10 is a view along line 10--10 of FIG. 9; and
FIG. 11 is a plan view of a motor unit for the valve of FIG. 9.
DETAILED DESCRIPTION
Referring to the accompanying drawings, especially to FIG. 1, there is illustrated a sprayer 10 spraying a field using a boom 12. In this instance, the field has been seeded using a seeder with a 24 foot width. In seeding the field, one row of seed has been omitted on every four passes of the seeder. This leaves marker lines 14 with no crop growth at 96 foot spacings across the field. Since the boom is 96 feet in length, the sprayer 10 may follow the marker lines across the field and cover the complete crop with no overlap or gaps between the boom passes.
FIGS. 2 and 3 illustrate a seed box 16 of a conventional form with a series of seed discharge openings 18 along the bottom wall of the box. Below each discharge opening is a seed meter 20 with the usual flute 22 for metering the seed from the seed box and driven by a transverse drive shaft 24. This structure is conventional.
To shut off the seed flow to one of the seed meters, a valve unit 26 is mounted inside the seed box, on the bottom wall, over one of the seed discharge openings 18. The valve unit has a base plate 28 that extends the full depth of the seed box bottom from back to front. This plate has a seed opening 30 that is in registry with the controlled seed discharge opening 18 of the seeder. Mounted on the base plate is a housing 32. The housing contains all of the working parts of the valve unit and may be removed from the base plate 28 and installed on alternative base plates with different sizes in order to fit the seed boxes of different manufacturers. Thus, the valve unit is "universal" in its application.
The housing 32 has a bottom wall 34, front and back walls 36 and 38 and two side walls 40 and 42. The top side of the housing is closed with a cover 44. Within the housing is a transverse panel 46 separating the interior of the housing into two compartments, arranged side by side.
A seed outlet opening 48 is formed in the bottom wall 34 of the housing and is aligned with the seed opening 30 in the base plate 28 and the respective seed discharge opening 18. The housing itself is oriented with its longest, side to side, dimension extending along the seed box in order to keep the complete valve unit entirely within the seed box and to avoid any need to modify the seed box. Two seed inlets 50 are formed in the front and back walls 36 and 38 in alignment with the seed outlet 48. These are sufficiently large that seed will run into the housing 32 through the inlets 50 and then through the outlet 48 to the seed discharge opening 18.
For closing the seed outlet 48, the housing has, in the same chamber as the outlet 48, a valve plate 52. This is a flat plate lying flush on the top surface of the bottom wall 34 of the housing.
The valve plate 52 carries a block 54 with a threaded bore 56 extending side to side in the housing. A threaded rod 58 is screwed into the bore 56 and is connected by a shaft coupling 60 to a motor output shaft 62 adjacent the transverse wall 46. The shaft extends through an opening in the wall to the second compartment, where its motor 64 is located. The wiring 66 for the motor 64 is let out of the housing through an opening 68 in the back wall. Operation of the motor rotates the threaded rod 58 and thus translates the valve plate back and forth in the housing to open or close the seed outlet 48.
The block 54 on the valve plate carries a magnet 70. This actuates two magnetic limit switches 72 and 74 inside the housing, with switch 72 being actuated when the valve is fully open and switch 74 being actuated when the valve is fully closed. The leads from the switches extend through the transverse wall 46 into the motor compartment and are brought out to the control system as part of the wiring 66.
The apparatus includes a console 76 that is mounted in the cab of the tractor pulling the seeder. The console has an off/on power switch 78 for turning the unit on and off. An automatic-manual switch 80 selects either automatic operation in which the unit operates automatically to shut off seed delivery after a set number of passes or operates in a manual mode controlled entirely by the operator using close-open switch 82. A reset switch 84 is used to reset the system to its initial condition or in conjunction with a multi position select switch 86 to set a new set of initial conditions. A single digit display 88 is also located on the console. It is a seven segment LED display with an additional decimal point.
The basic arrangement of the control system is illustrated in FIG. 7. As shown in that figure, a counter 90 receives input from the reset switch 84, the select switch 86 and a pass sensor switch 92. The pass sensor switch is a magnetic switch located on a stationary part of the seeder. It is actuated by a magnet on a part of the seeder, for example the seed box, that is raised at the end of a pass in order to turn the tractor and seeder for a return pass across the field. The counter output is passed to a control programmable read only memory (PROM) 94 which also receives input from the automatic-manual switch 80 and the closed-open switch 82. The control PROM delivers output to an output drive circuit 96 for driving the motor 64 of the valve unit and to the display 88. The two switches 72 and 74 of the valve unit 26 output to a fault detector 98 which is also coupled to the display 88 to provide a fault signal to the display.
The control system is supplied with operating power from the switching power supply 100. This power supply takes the incoming +14.2 volts from the tractor battery and outputs +5 volts for the control circuit. A switching regulator is particularly suited for the present unit because of its efficiency and size.
The detailed schematic of the controls is illustrated in FIG. 8.
As illustrated in that Figure, the selector switch 86 is a double pole, six throw switch connected to pins A, B, C of the counter 90 which is, in this embodiment, a 74LS192 counter. The input configuration of the pass select switch is as follows:
______________________________________Position C B A______________________________________1 0 0 12 0 1 03 0 1 14 1 0 05 1 0 16 1 1 0______________________________________
In operation, the input select switch 86 is first set by the operator to the required number of passes for a particular seeder/sprayer width combination. This selection is then loaded into the counter 90 using the reset switch 84.
Once the pass selection has been loaded into the counter, the operator begins seeding along the field. At the end of one pass, the seeder is raised and lowered again for the next pass. The normally open pass sensor switch 92 detects this and generates a low pulse when it closes. The pulse is inverted and sent as a positive going pulse to the count down input pin of the counter 90. The counter then counts down by one indicating that the seeder has completed one pass. The process continues until the counter reaches a count of zero. At this point, the grain valve 52 closes, blocldng the flow of grain in one particular row. Once the operator has completed pass zero, the next raising and lowering of the seeder will force the counter 90 to go to a binary 9 output. Pin 7 of the counter 90 is the most significant bit and this is fed to a Schmitt inverter 104. The output of the inverter is then fed to the load input of the counter on pin 11. This resets the counter to the original pass selection. The whole process keeps repeating as the seeding progresses, pass after pass.
The output control PROM 94 takes information from counter 90 and the double pole double throw automatic-manual switch 80, and outputs the required drive signals for the LED display 88 and the valve unit 26. The PROM 94 is based on Texas Instruments TBP18S030, 32 by 8 Bit word PROM. The 32 words are divided into four memory areas:
1. Words 0-7 are dedicated to the automatic mode of operation;
2. Words 8-15 are dedicated to the manual "close valve" operation;
3. Words 16-23 are not used; and
4. Words 24-34 are dedicated to the manual "open valve" operation.
In the automarie mede of operation, address bits A3 and A4 are set to zero. Thus only the first 8 words are selected. The PROM 94 then takes the output signals from the counter 90 and from this, determines which of the 8 words should be selected. One word is dedicated to each possible pass selection (i.e. 1, 2, 3, 4, 5 or 6) and one word is dedicated to the `close valve` operation. Word 7 is not used. Depending on which word is selected, either the output data line 7 will be Hi or Lo. This line is used to turn the Output Drive Circuitry either on or off, which corresponds to the seed valve being either closed or open. Output data lines D0 to D6 are used to drive the 7-segment LED display 88. This LED indicates at which pass the operator is at (in which case the grain valve is still open), or it indicates that the grain valve is closed (i.e. during the pass zero).
In the manual mode of operation, either words 8 to 15 or words 24 to 31 are selected. Address bit A3 is held Hi during this time by the automatic-manual switch 80, in order to accomplish this. If the close valve operation is chosen with switch 82, then address bit A4 is held Lo, thereby choosing words 8 to 15. The output on D7, pin 9 will go Hi to signal the output drive circuit 96 to close the valve. The LED display 88 will show a `C` to indicate this. If on the other hand the open valve operation is chosen, address bit A4 is held Hi, thereby choosing words 24 to 31. The output on D7, pin 9 will now go Lo, signaling to the output drive circuit 96 to open the grain valve. The LED display 88 will now show `O` to indicate this.
The drive circuit 96 provides the necessary voltage, at the proper polarity, to the D.C. motor 64 in the valve 26 in order to open or close the valve. It consists of four transistors 106, 108, 110 and 112, a 7406 output inverter chip 114, two NAND gates 116 and 118 and the two limit switches 72 and 74 of the valve unit. It operates as follows:
When pin 9 of the control PROM 94 goes Hi, indicating that the motor is to close the grain valve, the output on pin 3 of NAND gate 116 goes Lo. This Lo. signal is fed to pins 11 and 13 of the inverter chip 114, forcing the outputs on pin 12 and 10 to go Hi. This turns transistors 106 and 108 on hard (i.e. saturation), forcing current to flow through the motor. The motor, which is connected to the seed valve via the grain valve shaft, begins to rotate clockwise, which forces the grain valve to start closing. When the grain valve has reached the end of its required travel, the fully closed limit switch 74 of the valve unit closes, forcing a Lo signal on pin 2 of NAND gate 16. This causes the output to go Hi, which in turn forces the outputs on pins 12 and 10 of the chip 114 to go Lo. The transistors 106 and 108 are then cut off and the motor stops rotation. When the seed valve starts to close, the fully open limit switch 72 opens up, forcing a Hi level on pin 5 of NAND gate 118.
When the valve opens up again, pin 9 of the Control PROM 94 goes Lo. This Lo signal gets inverted by a Schmitt inverter 120, and gets fed to pin 4 of NAND gate 118. Since open switch 72 is still open, a Hi level is present on pin 5 of NAND gate 118. Thus, the output of the NAND gate goes Lo, gets inverted by the inverter chip 114, and tums transistors 110 and 112 on. Current now flows in the opposite direction through the motor, forcing it to rate counterclockwise. The valve then begins to open up. When it reaches the end of its required travel, the fully open limit switch 72 closes, forcing a Lo level on pin 5 of NAND gate 118. The output of the NAND gate then goes Hi, gets inverted by chip 114, and cuts off transistors 110 and 112. The motor then comes to a stop. When the valve starts to open, the fully closed switch 74 opens up, forcing a Hi level on pin 2 of NAND gate 116. Thus the circuit is ready for the next time when the output on pin 9 of the control PROM 94 goes Hi. This indicates that it is time to close the valve again, and the whole process repeats itself.
The fault detection circuit 98 alerts the operator that something is wrong with the valve unit. This could be a jammed grain valve, an improperly seated grain valve or a broken connection along the wiring harness. The circuit consists of two NAND gates 122 and 124, and inverter 126 and an oscillator 128.
Whenever both limit switches are open, the output of NAND gate 122 goes Lo. This Lo level gets inverted by inverter 126, which is fed to pin 10 of NAND gate 124. This NAND gate acts as a "front door" for the oscillator output. When pin 10 is at a Hi level, the oscillator signal is fed through to the output. This output then goes to pin 10 of the 7-segment LED 88, which corresponds to the decimal point. Thus if both pins 12 and 13 of NAND gate 122 are Hi, indicating a malfunction, the decimal point on the LED 88 will begin to flash at approximately 4 hertz. This will alert the operator that something has gone wrong. When the grain valve is either closing or opening, both limit switches will be open for approximately four seconds. Thus a flashing LED at the end of a pass does not indicate an error. It merely indicates that the motor is presently running.
An alternative embodiment of the invention is illustrated in FIGS. 9, 10 and 11. In FIGS. 9 and 10, the valve unit 130 includes a base plate 132 that is permanently mounted on the bottom wall of the seed box. The base plate has a seed opening 134 that aligns with the seed opening in the seed box. The opposite sides of the base plate have score lines 136 to provide snap off edges so that the base plate can be fit into most any seed box. The base plate carries a set of over--center clamps 138 that clamp a base unit 140 onto the top of the base plate. The base unit includes a bottom wall 142 and a cover 144 that provide between them a slot 146. The bottom wall and cover have registering openings 148 and 150 adjacent one end of the base unit. At that end, a foam block 152 extends across the base unit, between the bottom wall and the cover.
A valve plate 154 slides in the slot 146 between an open position retracted into the slot and opening the openings 148 and 150 and a closed position extending across the openings and engaging the foam block 152. The foam block serves for seed release, so that any seed captured between the side of the valve plate and the foam block will not cause jamming of the valve.
A lug 156 is mounted on the top of the valve plate 154 and is connected to the core 158 of a cable 159. The cable sheath 160 is connected to the cover 144.
The cable 159 leads from the valve unit to a motor unit 162 illustrated in FIG. 11. This motor unit has a housing 164 carrying a pivot arm 166 mounted on the base by a pivot 168. The cable core is connected to the rocker arm at a position spaced from the pivot. A second cable 159' is connected to the arm 166 on the other side of pivot 168 for operating a second valve unit 130'. The cable sheaths are fastened to the motor unit housing. Two limit switches 170 and 172 are mounted on the motor unit housing for actuation by the pivot arm when it is in either an open or closed position corresponding to the open and closed positions of the valve plate. The pivot arm is driven by a lead screw 174 running in a nut 176 mounted slidably and rotatably on the arm. The lead screw is driven by a reversible electric motor 178.
While particular embodiments of the present invention have been described in the foregoing it is to be understood that other embodiments are possible within the scope of the invention. For example, the valve plate 52 may be mounted in nylon or the like glides above the base plate 28 to avoid jamming of some sizes of seed. The valve unit may be mounted to eliminate seed rows that coincide with the left wheel of the tractor during spraying operations, rather than the centre of the tractor. Where desired two valves can be used in the seed box to generate tram lines. Other modifications will be apparent to those skilled in the art. The invention is thus to be considered limited solely by the scope of the appended claims.
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For marking a field with unseeded rows during seeding, the seed box of a seed drill is equipped with a valve unit mounted inside the box for shutting off seed flow to one of the seed cups during selective passes. A control system for the unit allows the shut-off to be automatic, after a selective number of passes have been completed, or manual as selected by the operator. The unseeded rows are used after germination for guiding a crop sprayer so that there will be no spray overlap and no gaps between the sprayer passes.
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BACKGROUND OF THE INVENTION
In the graphic arts, it is desirable to produce a color proof to assist a printer in correcting a set of photomasks which will be used in exposing printing plates. The proof should reproduce the color quality that will be obtained during the printing process. The proof must be a consistent duplicate of the desired half tone or line image, and should neither gain nor lose color. Visual examination of a color proof should reveal the following characteristics:
1. Any defects on the photomask.
2. The best color rendition to be expected from press printing of the material.
3. The correct gradation of all colors and whether grays are neutral.
4. The need, if any, for subduing any of the colors and/or giving directions for altering the film photomask before making the printing plates.
Color proofing sheets for multi-colored printing have heretofore been made by using a printing press proof which requires taking all the steps necessary for actual multicolor printing. Such a conventional method of color proofing has been costly and time consuming. Alternate color proofing methods have therefore been developed to simulate the quality of press proofs. There are two known types of photographic color proofing methods, namely, the surprint type and the overlay type.
In the overlay type of color proofing, an independent transparent plastic support is used for producing an image of each color separation film. A number of such supports carrying colored images are then superimposed upon each other and placed on a white sheet to produce a color proof. The overlay type of color proofing method has the disadvantage that the superimposed plastic supports tend to darken the color proofing sheet, and, as a result, the impression of the color proofing sheet thus prepared becomes vastly different from copies actually obtained by a conventional printing press proof. Its primary advantage is that it is quick and can serve as a progressive proof by combining any two or more colors in register.
In the surprint type of color proofing method, a color proofing sheet is prepared by successively producing images of different colors from different color separation films onto a single receptor sheet. This is done by utilizing a single opaque support and by applying toners, photosensitive solutions or coatings of photosensitive materials of corresponding colors on the opaque support in succession. An example of this approach is described in U.S. Pat. No. 3,671,236. An advantage of the surprint type of color proof is that the color saturation is not influenced by superimposed plastic supports. This method more closely resembles the actual printing and eliminates the color distortion inherent in the overlay system.
Various processes for producing copies of an image embodying photopolymerization and thermal transfer techniques are known as shown in U.S. Pat. Nos. 3,060,023; 3,060,024; 3,060,025; 3,481,736; and 3,607,264. In these processes, a photopolymerizable layer coated on a suitable support is imagewise exposed to a photographic transparency. The surface of the exposed layer is then pressed into contact with the image receptive surface of a separate element and at least one of the elements is heated to a temperature above the transfer temperature of the unexposed portions of the layer. The two elements are then separated, whereby the thermally transferrable, unexposed, image areas of the composite transfer to the image receptive element. If the element is not precolored, the tacky unexposed image may now be selectively colored with a desired toner. The colored matter preferentially adheres to the clear unpolymerized material. U.S. Pat. No. 3,574,049 provides a transfer process for printing a design on a final support which comprises (a) printing a design onto a temporary support, (b) superimposing the temporary support and the final support, (c) applying heat and/or pressure to the superimposed structure formed in (b), and (d) separating the temporary support from the final support which retains the printed design. The affinity of the design for the temporary support is lower than its affinity for the final support.
In U.S. Pat. No. 3,721,557 a method of transferring colored images is claimed which provides a stripping layer coated between the photosensitive element and the support. When the photosensitive layer is exposed to actinic light and developed, the more soluble portions are selectively removed to produce a visible image. The image-carrying support is pressed against a suitable adhesive coated receptor and, subsequently, the carrier support sheet is stripped to accomplish the transfer of the image. A fresh layer of adhesive is applied to the receptor for each subsequent transfer.
U.S. Pat. Nos. 4,260,673 and 4,093,464 describe positive working one-piece proofing systems based on orthoquinone diazides. In U.S. Pat. 4,093,464 a colored image is transferred to a receiver sheet after exposure and development. U.S. Pat. 4,260,673 describes transfer of a solid color layer to a receiver sheet prior to exposure and development. U.S. Pat. No. 4,659,642 teaches a positive working color proofing system which has a transparent substrate, a colored photosensitive layer on the substrate, and a top adhesive layer. The present invention improves upon the foregoing by incorporating an improved positive working color proofing film comprising a poly(vinyl acetal/vinyl alcohol/vinyl acetate) terpolymer in the photosensitive layer.
SUMMARY OF THE INVENTION
The present invention provides an improved method for forming a colored image which comprises:
A. providing a photosensitive element which comprises, in order:
(i) a substrate having a release surface; and
(ii) a photosensitive layer on said release surface, which photosensitive layer comprises a light sensitive, positive working, naphthoquinone diazide compound; a resinous binder composition, which composition contains at least 20% of a resin having the general formula
--A--B--C--
wherein a plurality of each of components A, B and C occur in ordered or random sequence in the resin and wherein A is present in said resin at about 5% to about 20% by weight and comprises groups of the formula ##STR1## B is present in said resin at about 4% to about 30% by weight and comprises groups of the formula ##STR2## and C is present in said resin at about 50% to about 91% by weight and comprises acetal groups consisting of groups of the formulae ##STR3## where R is lower alkyl or hydrogen, and wherein said group I. is present in component C from about 75% to about 85%; group II. is present in component C from about 3% to about 5%; and group III. is present in component C from about 10% to about 22%; wherein all acetals are based on the mol number of components (C) and at least one colorant; and
(iii) an adhesive layer in direct contact with said photosensitive layer, which adhesive layer comprises a polyvinyl acetate polymer and which adhesive layer is nontacky at room temperature, thermally activated and can be transferred at temperatures between 60° C. and 90° C.; and
B. either
(i) laminating said element with heat and pressure via said adhesive layer to a developer resistant receiver sheet; and removing said substrate by the application of peeling forces; and imagewise exposing said photosensitive layer to actinic radiation; or
(ii) imagewise exposing said photosensitive layer to actinic radiation; and laminating said element with heat and pressure via said adhesive layer to a developer resistant receiver sheet; and removing said substrate by the application of peeling forces; or
(iii) laminating said element with heat and pressure via said adhesive layer to a developer resistant receiver sheet; and imagewise exposing said photosensitive layer to actinic radiation; and removing said substrate by the application of peeling forces; and
C. removing the exposed areas of said photosensitive layer with a suitable liquid developer, which removing is conducted at a temperature at which said adhesive layer is substantially non-tacky; and preferably
D. repeating steps A through C at least once whereby another photosensitive element having at least one different colorant is laminated onto said receptor sheet over the non-removed portions of the previously laminated photosensitive layer or layers.
The invention also comprises the above described photosensitive element.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
In carrying out the method of the invention, one employs a photographic element which broadly comprises a substrate having a release surface, a colored photosensitive layer on the release surface and an adhesive layer on the photosensitive layer. Optional additional layers containing anti-halation materials, adhesion promoters or release agents may also be used.
In the preferred embodiment, the substrate is composed of a dimensionally and chemically stable base material which does not significantly change its size, shape, or chemical properties as the result of the heating, coating or other treatments which it must undergo. One preferred material is polyethylene terephthalate. In the usual case it has a thickness of from about 1 to about 10 mils, a more preferred thickness is from about 2-5 mils and most preferably from about 2-3 mils. Suitable films include Hostaphan 3000, available from Hoechst Celanese Corporation, Mylar D, available from DuPont and Melinex grades 0; 052; 442; 516 and S, available from ICI. The surface of the substrate may be smooth or may be provided with a matte texture by various methods known in the art.
Matte films include Melinex 377 and 470 from ICI. These materials have the unique property of giving the final image a desired matte finish without any extra steps. One can control the gloss of the final image by properly selecting the matte finish of the temporary support. This effect works because the top layer of the final image is originally in contact with this matte surface. This does not occur with a separate release layer between the temporary support and photosensitive layer. An additional advantage of coating on a matte surface is that subsequent transferred layers generally adhere better to a rough surface than to a smooth surface.
A similar matte finish of the final image can be obtained by embossing the shiny, top surface of the image with a matte material, such as described above. This is done by laminating together the final image and matte material under pressure and temperature. The matte material is then generally removed after lamination. The advantage of this method is that the finish of the final proof can be varied. Furthermore, the matting material can be used repeatedly.
A third method for producing a matte finish uses a heat transferable layer, such as Butvar 90, available from Monsanto, coated onto a film with a rough surface, such as Melinex 329, available from ICI. The transferable layer is laminated to the final image under pressure and temperature. Then the film with the rough surface is peeled off. The rough surface of the transferred layer imparts a matte finish to the final image. The advantage is that all layers appear matte and that the extra transferred layer protects the image. U.S. Pat. Nos. 4,294,909 and 4,376,159, also suggests various methods for making a matte surface.
In either case, the substrate must have a release surface, that is, it must be capable of releasably holding the photosensitive layer thereto. This may be accomplished either by the substrate surface being inherently releasable, being rendered releasable by a suitable treatment or being provided with a release layer over the substrate surface. Such a release layer may comprise polyvinyl alcohol.
Releasably bonded to the release surface is the photosensitive layer. The photosensitive layer broadly comprises a photosensitizer, colorants, binding resins, and other optional ingredients such as plasticizers, acid stabilizers, surfactants, antistatic compositions, uv absorbers and residual coating solvents.
The preferred photosensitizer is a light sensitive, naphthoquinone diazide. The most preferred photosensitizer is the ester of bis-(3-benzoyl-4,5,6 trihydroxy phenyl)-methane and 2-diazo-1-naphthol-5-sulfonic acid as taught in the U.S. Pat. No. 4,407,926. Other suitable photosensitizers are taught in the U.S. Pat. Nos. 4,266,001, 3,106,365, 3,148,983 and 3,201,239. The diazo compounds of choice are preferably soluble in organic solvents.
Suitable binding resins have the general formula
--A--B--C--
wherein a plurality of each of components A, B and C occur in ordered or random sequence in the resin and wherein A is present in said resin at about 5% to about 20% by weight and comprises groups of the formula ##STR4## B is present in said resin at about 4% to about 30% by weight and comprises groups of the formula ##STR5## and C is present in said resin at about 50% to about 91% by weight and comprises acetal groups consisting of groups of the formulae ##STR6## where R is lower alkyl or hydrogen, and wherein said group I. is present in component C from about 75% to about 85%; group II. is present in component C from about 3% to about 5%; and group III. is present in component C from about 10% to about 22%. All of said acetal members are based on the mol number of acetal units in component C. An important resin selection criterion is that it must be a good firm former.
These resins are more fully described in U.S. Pat. No. 4,665,124 which is incorporated herein by reference.
The colorants useful for the present invention include various classes of dyes and pigments. In the most preferred embodiment, pigments having an average particle size diameter of about 1 micrometer or less are used.
Optional plasticizers which may be incorporated into the photosensitive layer include those of the phthalate and phosphate types. Preferred plasticizers include dibutyl phthalate and dimethyl phthalate. Polymeric plasticizers include acrylic resins such as Carboset 525 available from BF Goodrich. Developing aids include polymers with acid groups such as Carboset XL27 available from BF Goodrich, Scripset 540 available from Monsanto and Elvacite 2028 available from DuPont.
These ingredients may be blended with such compatible solvents as gamma butyrolactone, diacetone alcohol, propylene glycol monomethyl ether, ethanol, methyl cellosolve and methyl ethyl ketone, coated on the release surface, and dried. In the preferred embodiment, the photosensitive layer has a coating weight between approximately 0.1 and 5.0 g/m 2 . The most preferred weight is from about 0.4 to 2.0 g/m 2 .
In the preferred embodiment, the photosensitizer is present in the photosensitive layer in an amount of from about 15 to about 60 percent by weight; or more preferably from about 20 to about 50 percent by weight.
In the preferred embodiment, the colorant is present in the photosensitive layer in an amount of from about 10 to about 40 percent by weight; or more preferably from about 13 to about 34 percent by weight.
In the preferred embodiment, the binding resin is present in the photosensitive layer in an amount of from about 20 to about 75 parts by weight; or more preferably from about 30 to about 70 parts by weight.
In the preferred embodiment, the plasticizer, when one is used, is present in the photosensitive layer in an amount of up to about 20 parts by weight; or more preferably up to about 15 parts by weight and most preferably from about 12 to about 15 parts by weight.
Typical formulations for the photosensitive layer include:
______________________________________ Yellow Magenta Cyan Black______________________________________propylene glycol monomethyl 57.00 50.40 33.72 43.44ethermethyl ethyl ketone 9.37 10.72 34.22 25.20gamma-butryolactone 19.35 22.53 16.96 15.33diacetone alcohol 9.72 11.12 9.40 11.09polyvinyl acetal/alcohol/ 0.82 0.88 1.04 0.73acetate resin in example #1Butvar B-90 0.36 0.41 0.45 0.42Scripset 550 1.20 1.19 1.20 --Scripset 540 -- -- -- 1.41Above diazo from U.S. 1.50 1.87 1.78 1.494,407,926phthalo blue pigment -- 0.01 1.23 --yellow pigment 0.68 0.02 -- --magenta pigment -- 0.85 -- --black pigment -- -- -- 0.89______________________________________
The adhesive layer comprises polyvinyl acetate and may optionally contain such other desired components as uv absorbers, optical brighteners, anti-static compositions and plasticizers. Useful polyvinyl acetates non-exclusively include Mowilith DM-6, 20, DM-22, 25, 30 and mixtures thereof, available from Hoechst AG. These are usually dispersed in water, or dissolved in methyl isobutyl ketone or n-butyl acetate or other solvent compositions for coating on the photosensitive layer. It is then dried to a coating weight of from about 5 to about 30 g/m 2 , more preferably from about 10 to about 20g/m 2 . The layer may optionally contain a uv absorber such as Uvinul D-50 from G.A.F. It may also contain a polymeric plasticizer such as Resoflex R-296, a polyester plasticizer available from Cambridge Industries or Carboset 525 available from BF Goodrich. It ma also contain antistats, such as Gafac and Gafstat from G.A.F. It may also contain other resins, such as Nitrocellulose RS 1/2, available from Hercules. It may also contain an optical brightener such as Uvitex OB from Ciba Geigy. The adhesive layer should not be tacky to the touch, during storage or during development of the photosensitive element. The layer should have a softening point in the range of from about 60° C. to about 180° C., preferably 60° C. to 120° C., more preferably 60° C. to 100° C. In the preferred embodiment, the polyvinyl acetate is present in the adhesive layer in an amount of greater than about 50 percent by weight. The plasticizer may be present in an amount of up to about 30 percent by weight, the uv absorber up to about 20 percent by weight, the optical brightener up to 1.0 percent by weight, and other resins up to about 50 percent by weight.
Typical adhesive formulations include:
______________________________________I. Water 50.00 Mowilith DM-22 50.00II. i-butyl acetate 78.00 Resoflex 1.00 Mowilith 30 21.00III. i-butyl acetate 79.90 Uvitex OB 0.10 Mowilith 30 20.00______________________________________
In operation, the photosensitive element is laminated to a receptor sheet via the adhesive layer. The receiver sheet should be resistant to any adverse effects which may be caused by the developer of choice. For example, the receiver sheet should be water resistant if aqueous developers are used. Plastic or plastic-coated receiver sheets are useful for this purpose.
Useful receiver sheets include Melinex 329; 339; 994 and 3020 from ICI. Other white and nonwhite receiver sheets may also be used. Rough textured and/or adhesion promoted surfaces are preferred for the receiver, which must be able to withstand the laminating and development processes.
Lamination may be conducted by putting the receiver sheet in contact with the adhesive side of the colored composite and then introducing the two materials into the nip of a pair of heated laminating rollers under suitable pressure. Suitable laminating temperatures usually range from about 60° C. to about 90° C., preferably about 75° C. to about 85° C.. After lamination, the substrate is peeled away, usually merely employing manual peeling forces. The adhesive and photosensitive layers thus remain on the receiver sheet.
The photosensitive layer is imagewise exposed by means well known in the art either before or after lamination. Such exposure may be conducted by exposure to a uv light source through a photomask under vacuum frame conditions. Exposure may be performed with actinic light through a conventional positive flat. Exposures after lamination and peel apart are preferred for emulsion-to-emulsion contact. Mercury vapor discharge lamps are preferred over metal halide lamps. Filters may be used to reduce light scattering in the material.
After lamination, peel apart and exposure, the photosensitive layer is developed by dissolving the exposed area in a suitable developer and dried. A suitable developer useful for developing a lithographic printing plate made with the resin of the present invention includes an aqueous solution containing one or more of the following groups:
(a) a sodium, potassium or lithium salt of octyl, decyl, dodecyl, or tetradecyl monosulfate;
(b) a sodium, lithium, potassium or ammonium metasilicate salt,
(c) a lithium, potassium, sodium or ammonium borate salt;
(d) an aliphatic dicarboxylic acid, or sodium, potassium or ammonium salt thereof having from 2 to 6 carbon atoms; and
(e) mono, di-, or tri-sodium or potassium phosphate.
Other suitable developers include water, benzoic acid or sodium, lithium and potassium benzoates and hydroxy substituted analogs thereof as well as those developers desribed in U.S. Pat. No. 4,436,807. The adhesive layer is not substantially removed by this development. Specific examples of suitable developers non-exclusively include
______________________________________I.Water 95.0Sodium decyl sulphate 3.0Disodium phosphate 1.5Sodium metasilicate 0.5II.Water 89.264Monosodium phosphate 0.269Trisodium phosphate 2.230Sodium tetradecyl sulfate 8.237______________________________________
Any developer solution which satisfactorily removes the exposed areas of the photosensitive layer after exposure while retaining the image areas may be used. The selection of developer is well within the ability of the skilled artisan.
The process can then be repeated whereby another photosensitive element having a different color is laminated to the same receiver sheet over the previously formed image. In the usual case, four colored layers are employed to produce a full color reproduction of a desired image. These are cyan, magenta, yellow and black.
The following non-limiting example serves to illustrate the invention.
EXAMPLE
The resin is made from a copolymer of polyvinyl alcohol/polyvinyl acetate, Vinol 523. 75.0G of Vinol 523 which has from about 75% to 80% hydroxyl groups by weight and an average molecular weight of about 70,000, is dissolved in a solution comprising 225.0 g of water and 200.0 g of ethanol for 16 hours at 70° C. after which 10.13 of hydrochloric acid (37%) is added and the temperature adjusted to 60° C. while mixing vigorously. 37.66 g of propionaldehyde is slowly titrated into the reaction mixture. Simultaneously, 250.0 g of ethanol is likewise titrated into the reaction mixture. The mixture is then neutralized to a pH of 7.0 with a sodium carbonate/sodium hydroxide (50/50) mixture. The product is isolated in granular form by precipitation with water. It is then dried so as to have a moisture residue of not greater than 1.0%. A yield of 107 g or about 96% is obtained. The average molecular weight is about 90,000.
Using standard analytical techniques, the product is found to consist of 13.6% acetate, 9.85% hydroxyl, and 76.6% acetal groups. Of the acetal groups, 80% are found to be six-membered cyclic acetal, 4% are five-membered cyclic acetal, and 16% are intermolecular acetals.
Four photosensitive solutions of cyan, yellow, magenta, and black are produced according to the photosensitive formulations described above. The pigment is introduced as a dispersion of the above polyvinyl acetal/alcohol/acetate resin and the appropriate pigment in a 1:1 solvent mixture of gamma butryolactone and propylene glycol monomethyl ether. The pigment and resin loading in the dispersions are as follows:
______________________________________ Cyan Yellow Magenta Black______________________________________Pigment 6.5% 5.0% 5.2% 5.5%Binder 5.5% 6.0% 5.2% 4.5%______________________________________
The solutions are coated and dried separately to the required optical density onto 3 mil Melinex 516 polyester films as temporary support. The surface densities are roughly 0.8 g/m 2 for cyan, 0.9 g/m 2 for yellow, 1.0 g/m 2 for magenta, and 1.3g/m2 for black. The adhesive solution, in particular adhesive formulation number II from above, is coated on top of the photosensitive layers and dried to an surface density of 12 g/m 2 . The yellow composite is then laminated at 80° C. with the adhesive side onto either side of a 7 mil Melinex 3020 polyester receiver sheet. The 516 temporary support is peeled away after lamination, leaving the adhesive and photosensitive layers on the receiver sheet. The yellow photosensitive layer is then exposed to actinic light through a photographic flat for the yellow color. The receiver sheet with the exposed yellow layer is then immersed for 15 sec in developer II from above at 27° C. with gentle pad rubbing on the photosensitive side. The exposed yellow areas are thereby washed off and the nonexposed areas remain during development. The adhesive layer is not effected by the developer. After this treatment, the imaged material is rinsed and then dried. The magenta composite is then laminated as before onto the imaged, yellow side of the receptor sheet. The temporary support is removed as before. The magenta layer is then exposed through the magenta flat. It is then processed as with the yellow. The magenta is followed in a like manner by cyan and then by black to give a four color image which is an accurate representation of the original from which separations are prepared.
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This invention relates to positive working photosensitized sheet constructions which, upon exposure to an actinic radiation source through a screened image, can accurately reproduce said image. The construction is useful as a color proofing film which can be employed to predict the image quality from a lithographic printing process.
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PRIORITY CLAIM
[0001] This application claims priority from U.S. provisional application serial no. 60/949,197 filed Jul. 11, 2007 by Dean Zeisbrich et al. for “Solution and Method for Cleaning and Restoration of Plastic Composite Headlight Material”.
TECHNICAL FIELD
[0002] The present invention relates to a solution and method for cleaning and restoration of plastic material and more specifically cleaning and restoration of plastic headlight lenses used in vehicles, such as the lens covers for headlights and taillights of automobiles, motorcycles, trucks, and other motor vehicles.
BACKGROUND
[0003] Plastic materials are currently in widespread use for a number of products having exposure to the outside environment. A number of the properties of plastic has resulted in their widespread use. These advantages include the fact that plastics are generally inexpensive, transparent or light transmissive, or light weight, or relatively easy to mold and shape, and may be colored to allow use of an indicator light that would be seen as having a selected color. For these reasons the plastic materials have been widely adopted in the motor vehicle industry, including their use as lens covers secured over headlights and taillights.
[0004] Although in widespread use, plastic headlights are subject to unique and demanding environmental and physical conditions. Although plastic and polycarbonate lenses do suffer as a result of UV exposure, that UV exposure is not properly characterized by the yellowing that both industry and the public assume to be plastic failure. This misconception is commonly held for a number of reasons. One reason is that many people have tried to clean their headlights with conventional methods or cleaners and met with little or no success. The actual damage suffered by the lens due to UV exposure is primarily crazing of the surface of the lens. Polycarbonate, the primary material of headlight lenses, is well known for its expansive nature and its tendency to craze from exposure to UV light and temperature differences. This shortcoming of polycarbonate is further exasperated by the extremely hot conditions created by modern headlamps within the headlight structure.
[0005] Further compromising the lens is the fact that because of its extremely tough nature and tremendous resilience to impact, manufacturers have been able to build lenses that are thin and lightweight, while at the same time meeting the impact resistance requirements of the Department of Transportation. Unfortunately the thinness of these lenses has compromised their ability to resist expansion under heated conditions leading to crazing and providing the foothold for the initial buildup on the lens. Surface temperatures of a modern headlight lens, when running daylight, they can easily reach temperatures in excess of 150 degrees. These temperatures also give rise to another unique condition that plastic headlight lens are subjected to where the surface of the lens serves as an evaporative surface for water and humidity in the air and any other potential contaminants that are evaporated leaving the solids on the surface of the lens and in the opened crazed lens surface. These contaminants can include hydrocarbons, asphaltic content from the roadway, and mineral deposits from water, all of which find a foothold in the microscopically crazed surface of the lens. The deposits form in successive and initially very thin layers which are nearly undetectable by the naked eye until such a time as the accumulating deposits become larger and are more rapidly accumulated on the roughened profile below. Unfortunately by the time these contaminants become concentrated enough as to give hold to larger and more easily formed particulate/contaminants as to be visible to the naked eye the problem is well beyond the practical use of conventional waxes and cleaners the likes of which can at best remove some yellowing but leave behind the true root of the problem, the mineral layer and leave the lens subject to a rapid re-yellowing in some cases the re-yellowing is worse than that which was partially removed. These visible effects vary and can take up to 3 years to become visible.
[0006] Industry standard consists of several abrasive and/or coating processes that have been stated and are designed to remove the aforementioned and improperly characterized UV-damaged plastic in an attempt to reveal an undamaged clear surface. These methods are less efficient from a standpoint of time effectiveness, and continued serviceability of the lens. Further and more often than not, these methods serve to exasperate the condition that began in the headlight, a profile on the lens that is not smooth and is subject to future and more easily established build-ups. In addition, a common method of restoration involves a sanding and re-coating of the lens with any number of acrylic, lacquer, or other coating which is only a temporary fix as the build-up will establish itself on the coating either before or after the failure of that coating. It is best stated that industry and common misconception of the actual causes of the yellowed headlights, has led to their longstanding lack of proper maintenance as the cleaners above stated by manufacturer and the like will not remove the mineral deposits which are the root cause for the tremendous fouling of the lens leading to safety concerns and aesthetically unattractiveness.
[0007] It is an object to provide an alternative vehicle light lens cleaning product that is relatively inexpensive, provides rapid results, and can be used by unskilled users.
SUMMARY
[0008] The invention is a vehicle lens cover cleaning solution containing an aqueous solution of urea, minimum 30% by volume, with buffer to between 2 and 6 pH in combination with petroleum distillate of between 10-20% by volume. Nanoparticles having a size of 0.05 to 1.0 micron sapphire, one-eighth pound per gallon, are dispersed in 2-5% surfactant by volume.
DETAILED DESCRIPTION
[0009] The present solution and method remove build-up of contaminants on the surface of plastic resulting in a much more optically clear lens cover and removal of mineral deposits. This improves both the appearance of the lens and the safety of the lens cover. The resulting surface is very smooth and resistant to future build-up of contaminants. The results are achieved without the use of tools or sandpaper, buffers, or other abrasion devices. The improved appearance of the cleaned plastic may be achieved in five minutes or less per lens cover, depending on humidity and climate conditions and lens condition.
[0010] The plastic lens covers are generally made of polycarbonate. The lenses are marred by two general types of adherent material. The first is mineral deposits, such as calcium or other minerals. These form tenacious insoluble buildup on the surface of the lens. The other is road grime, made up of dirt and hydrocarbon residues. The presence of the grime makes the removal of the mineral deposits much more difficult.
[0011] The present invention has found that a combination of a surfactant, a solvent, and a detergent is not sufficient to clean discolored polycarbonate lenses well as they do not remove mineral buildup on lens. Two additional components are needed:
1. Hard nanoparticles such as diamond and sapphire particles. For the purposes of this invention, nanoparticles means 25 microns to submicron particle size. While the exact mechanism is not understood of action of these particles, it is believed that the nanoparticles act as a physical surfactant. Surfactants and detergents are believed to adhere to the nanoparticles, which penetrate the grime on the lens. In addition, even without scrubbing or abrasion, the mere physical application of the solution containing particles of this specified size and hardness (of the hardness of a sapphire nanoparticle) is believed to cut into the grim and aid in bringing solvents and detergents through the grim to the adherent mineral deposits. 2. A hyper concentrated solution of urea, that will rapidly crystallize on the lens surface. The formation of this crystal is believed to draw into its formation the liberated contaminants from the lens via an acid reaction resulting in precipitate and a salt formation. The urea also acts as an astringent, removing water and bringing the nanoparticles into contact with the lens contaminants.
[0014] The nanoparticles and hyper concentrated urea are added to standard cleaning solutions, i.e. solutions containing a solvent, a surfactant, and a detergent. These components dissolve grime and loosen the material solids on the surface of the lens. The citrus (and potentially other) solvents solubilize hydrocarbon grime contaminants that are both under the mineral build-up and inclusions within the mineral build-up. Further the surfactants (and potentially additional astringents) connect the nanoparticles to very small pits and crevices within the plastic material. As the contaminants are liberated from the surface of the lens, astringent components draw out the moisture and form a crystalline structure which has inclusions of nanoparticles which are hard, sharp, and abrasive. These abrasive particles serve to break up oxidized mineral contaminants on the lens surface. Rubbing off of the crystallized solution from the lens causes a highly efficient abrasion of the lens restoring a nearly new appearance to the lens.
[0015] The present solution may be sold as a kit containing a pre-soaked applicator wrapped in plastic bottle and/or spray/foam. This would also include a pair of latex gloves to prevent exposure to the nano particles. In one embodiment the components of the solution are as follows:
EXAMPLE SOLUTION 1
[0000]
1) Urea (Hyper Concentrated solution) 30%-50%
2) Citrus Terpene, Terpenoid or other citrus oil product 2%-7% by volume
3) Acetic Acid 0.4-2.5 in solution PH (CAS 64-19-7)
4) Citric Acid 0.4-2.5 in solution PH (CAS 77-92-9)
5) Sapphire nano particles (particle size 0.05-0.3 & 1 micron) 1%-5% by volume
6) Surfactant 1%-5% by volume
7) Rinse Agent 1%-5% by volume
8) Diamond nano particles (800 mesh) 0.05-0.5% by volume
9) Silica 5%-7% by weight
10) Sodium Hyperchloride (Lye) 1%-3% by volume
11) Ammonia Bifluoride Detergents 2%-10% by volume
12) Commercially Available Windshield Cleaner Solution as remainder, or water.
In addition to the above components, there are a number of possible additions and alternates to the above solution including:
Fragrance Bittering Agent (to prevent accidental ingestion) Gelling Agent Colorant
EXAMPLE 2
[0000]
Per 500 cc container, approximately ±5% of the following:
water—remainder
100 cc of commercially available windshield wiper fluid
80 cc of commercially available lemon oil w/petroleum distillate
230 ml of urea crystal (CAS 57-13-6)
Shake mixture—Endothermic reaction occurs
40 cc of ammonium bifluoride detergent (commercially available)
20 cc of acetic acid (CAS 64-19-7)
20 cc of citric acid (CAS 77-92-9)
60 cc of silica
5 dry karat wt. of 800 mesh diamond powder
2 dry oz. of 0.05 micron sapphire powder
2 dry oz. of 0.03 micron sapphire powder
2 dry oz. of 1 micron sapphire powder pH range between 3.0-4.0
EXAMPLE SOLUTION 3
[0045]
[0000]
Component
Amount/Gallon
Urea
1200-1500
g.
Citric Acid
200-300
g.
EDTA
250-300
g.
Sodium Hydroxide
200-300 gr to adjust
pH range to 3-5.5
Hydrogen Peroxide
32-48 ounces
(3% solution in water)
Isopropyl Alcohol
32-48 ounces
(91% solution in water)
ZEP (TM) organic acid concrete remover
350-450 gm by wt.
Hexane or asphaltic distillate
32-48
oz.
Sulfate of ammonia
100-200
g.
Sodium hydroxide
150
g.
.05 micron sapphire
⅛ to ¼
Citric turpene
250-300
ml.
Commercial windshield wiper fluid to fill gallon or water.
pH to between 3.5 and 4.5
EXAMPLE SOLUTION 4
[0046]
[0000]
hydrogen peroxide
1.5
quarts
windshield wiper fluid
0.5
quarts
urea crystals
1500-2000
grams
citric acid
300-350
grams
citric turpene degreaser
25-300
ml
lemon oil cleaner with petroleum distillates
50-100
ml
ammonium biforide detergents
250-300
ml
1 micro aluminum particles
⅛
pound
1 micron sapphire particles
⅛
pound
.05 micron sapphire particles
⅛
pound
.3 micron sapphire particles
⅛
pound
organic acid
300-400
ml
water or preferably commercial windshield wiper fluid to fill one gallon
adjust pH to 2.75 to 3.5 with optimal pH at 3.
[0047] In any of these formulas, a detergent, a solvent, acids and bases, and a surfactant (some from commercial products) are combined with concentrated urea and nanoparticles. A number of different formulations have been tried. Most were acid solutions, although this is not thought to be essential. The specific pH may be in the range of 2.5-6.0 and be heavily buffered. The time and extent of application of these formulas will depend upon the condition of the lens to which the formulas are applied. The formulas will restore any headlight lens.
|
A solution for cleaning plastic headlight covers that includes an oily acid, a surfactant, a citrus turpene and hard nanoparticles of sapphire and diamond. Principal ingredients are carried by commercial windshield cleaning solution or in water.
| 2
|
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a material based on aluminium silicate, having pozzolanic properties, especially in Portland cement-based systems (mortar, concrete, paste, etc.). It concerns more particularly a dehydroxylated aluminium silicate-based material, which may be obtained by dehydroxylation treatment of clay mineral particles, in order to obtain or to enhance reactivity as an additive or addition (of the pozzolanic type) in Portland cement based systems (mortar, concrete, paste, etc.).
[0003] 2. Description of the Background
[0004] When added to Portland cement-based systems, aluminium silicate in the form of metakaolin reacts with the calcium hydroxide released by cement hydration to form calcium silicate hydrates (C—S—H). This is the pozzolan reaction. Metakaolin, as an artificial pozzolan, is often used in glass fiber reinforced cement to consume lime, and then, decrease the pH of the pore solution, allowing a better durability of the glass fibers.
[0005] This aluminium silicate in a reactive form can be obtained by a thermal calcination treatment of kaolin or kaolinite, generally from an argillaceous starting material. The endothermic reaction is as follows:
Al 2 O 3 .2SiO 2 .2H2O→Al 2 O 3 .2SiO 2 +2H 2 O (≈−418 joules/gram)
It takes place at a temperature of about 500 to 650° C., depending on the nature of the initial clay.
[0007] The industrial implementation of this treatment needs to satisfy two requirements: treating the argillaceous material thoroughly in order to convert all the kaolin into metakaolin, without the temperature of the treated material reaching the breakdown temperature of metakaolin, which may be converted (during an endothermic reaction) at about 900° C. into an unreactive crystallised form such as mullite or cristobalite.
[0008] In one known industrial technique, clay in the form of pellets is treated in a plate furnace, in which each stage heated by burners to a given temperature comprises a plate on which a substantial thickness of clay is deposited, and scraper arms which ensure that the clay is exposed to the temperature of the stage for the desired time and which direct the material treated on one plate to the next plate. Typically, these installations impose a temperature gradient which increases in the circulation direction of the clay, of the order of 500 to 750° C. at the plates. In order to achieve these temperatures, the burners heat walls locally to much higher temperatures, and the components of the furnace, in particular walls and arms, which are subjected to high stresses need to be made of refractory materials with good thermal stability and/or need to be provided with a cooling system. Furthermore, the residence time of the materials in the furnace is very long and entails very significant energy consumption and, lastly, the fine particles which are produced by attrition of the pellets are entrained by the firing gases, therefore necessitating a treatment to remove dust from the fumes.
[0009] In another known technique, which is referred to as “flash calcination”, clay particles are subjected to considerable temperature gradients, so as to reach the treatment temperature almost immediately. In practice, the clay particles are placed in an environment whose temperature may be as much as 900 to 1000° C., or more, for a very short time, so that the heat exchanges bring the particle to the desired temperature of the order of 500-600° C. According to certain embodiments, the calcination furnace comprises an enclosed space in which a burner that produces the desired temperature is installed. This type of furnace involves the risk that the particles may come into contact with the flame of the burner and exceed the desired treatment temperature. Another type of flash calcination furnace, described in particular in U.S. Pat. No. 6,139,313, comprises a chamber for treatment by a toroidal gas stream, in which a very high-temperature plasma is formed by injecting fuel into a hot gas stream created upstream of the treatment chamber. The critical components of the furnace are once more exposed to very high temperatures, which necessitates complicated cooling devices.
[0010] The pozzolanic reactivity (PR) of the dehydroxylated material is determined by the amount of calcium hydroxide consumed by the pozzolan in a pozzolan-calcium hydroxide mixture. It is used to determine the knetic of the reaction in normal temperaute conditions.
[0011] The Chapelle test value, determines the potential of the pozzolan to comsume calcium hydroxide after a long time. It is obtained at higher temperature, to accelerate the pozzolanic reaction.
SUMMARY OF THE INVENTION
[0012] It is the purpose of the present invention to provide an improved aluminium silicate-based material.
[0013] The material of the invention is characterized by a high kinetic for the pozzolanic reaction. As a consequence, when the material is added in a Portland cement-based product, it accelerates the strength acquisition compared to Portland cement-based product containing commercially available metakaolin. The Portland cement-based product can be demoulded and put in service earlier.
[0014] More particularly, the material of the invention is characterized in that the pozzolanic reactivity (PR) following a 3-day cure is at least 50%. In optimised conditions, the PR following a 3-day cure is at least 62%.
[0015] The higher kinetic is such that the pozzolanic reactivity following a 7-day—cure is significantly improved. According to the invention, the PR following a 7-day cure is at least 92%.
[0016] In optimised conditions, the PR following a 7-day cure is at least 94%.
[0017] This improved material may be obtained by a process for dehydroxylation treatment of aluminium silicate, in which particles containing aluminium silicate are exposed to a temperature of at least 500° C., wherein the particles are in the form of a dry powder, and the dry powder is transported in a gas stream at a temperature of from 600 to 850° C., for a time which is sufficient to achieve the desired degree of dehydroxylation.
[0018] In such process, which is also an object of the invention, the material containing aluminium silicate, as a powdered form, reacts astonishingly rapidly in the transport gas, the temperature of which is nevertheless much less than the usual treatment temperatures of a “flash” calcination treatment, so that the process provides a thermal dehydroxylation treatment which is inexpensive to implement in terms of both the energy required and the materials used to make the treatment devices. Moreover, the dehydroxylated material has a quicker pouzzolanic reactivity than aluminium silicate dehydroxylated with conventional processes.
[0019] To provide a specific reference, the dry powder generally has a particle size of less than or equal to 100 μm, i.e. all the particles which form it have a size characterised by dimensions (diameter or apparent diameter) of less than or equal to 100 μm. Preferably, it is essentially composed of particles with dimensions of less than or equal to 80 μm. It advantageously comprises at least 60% by weight of particles with a dimension of less than 20 μm, and preferably a small quantity (for example less than or equal to 5%) of particles with dimensions greater than 40 microns (95% <40 microns).
[0020] Advantageously, the powder is formed from a hydrated base paste containing aluminium silicate, in the following way: the base paste is reduced into fragments, and the fragments of base paste are disaggregated by mechanical action in the presence of a hot gas at a temperature of the order of 500° C. to 800° C.
[0021] Unexpected in this process is that a simple mechanical operation of grinding, milling, kneading or the like, carried out in the presence of a hot gas with a temperature of greater than or equal to 500° C., which would usually be envisaged for drying a hydrated material, makes it possible not only to evaporate the water of hydration of the base paste, but furthermore to initiate separation of the bound water of the aluminium silicate, forming metakaolin. This operation is performed by transporting the powdered products with hot gas whose temperature (500 to 850° C.) is precisely defined so as, on the one hand, to permit sufficient progress of the reaction (temperature and transport time) and, on the other hand, not to form crystallised products that are stable in the presence of lime (upper limit of the temperature).
[0022] The mechanical action envisaged according to this process is preferably an action suitable for separating the particles constituting the mineral material of the base paste, in order to provide the dry material with its “natural” particle size distribution. This is why the term disaggregation is used here. Likewise, when it is used in the present description, the term grinding comprises any “gentle” type of action, in particular such as attrition, and is not limited to an operation suitable for reducing the particle size of a material by breaking up its constituent particles.
[0023] The temperature of the hot gas used in the disaggregation step is chosen to be less than 800° C., in order to avoid subsequent conversion of metakaolin into an unreactive form, but it is desirably as high as possible for rapid drying of the hydrated base paste. The temperature may be chosen within the range dependent on the water content and the inherent characteristics of the primary material, which are associated with its composition and therefore the quarry or source which is used. The precise temperature at which a kaolin is converted into metakaolin can be determined by subjecting the primary material to differential thermal analysis (DTA), the metakaolin transformation peak generally lying between 500 and 550 or 600° C. The temperature of the hot gas may advantageously be chosen to be of the order of 600 to 750° C., in particular 650 to 700°. This refers to the temperature of the gases after mixing and introduction of the argillaceous particles. It is therefore beneficial for the hot gas to be supplied at a temperature as close as possible to the transformation temperature, although this temperature should be as high as possible (850-900° C.) while being below the threshold corresponding to the reaction for conversion into mullite.
[0024] The conditions of the disaggregation step according to the invention permit substantial removal of the water present in the hydrated base paste. Typically, starting with a base paste having a water content of less than 30% by weight, in particular of the order of from 15 to 30% by weight, the disaggregated dry powder generally has a residual water content of the order of from 0 to 1% by weight.
[0025] Advantageously, the disaggregation is carried out by forcing the fragments of paste and the hot gas between grinding components. This produces a maximum surface area for contact between the paste and the hot gas, which promotes the exchange of heat and permits almost immediate drying.
[0026] By virtue of these drying conditions, the material of the base paste is reduced into a powder having the dimensions of its constituent particles. In general, the dry powder has a particle size of less than or equal to 100 μm, preferably less than or equal to 80 μm. It advantageously comprises at least 60% by weight of particles with a dimension of less than 20 μm, and preferably a small quantity (for example less than or equal to 5%) of particles with dimensions greater than 40 microns.
[0027] According to the primary material which is used, in particular when it is a natural material such as clay, the disaggregation step is followed by a step of separating coarse particles such as sand, in particular using a cyclone, after which the dry powder intended to undergo the heat treatment is recovered.
[0028] According to the primary material which is used, a dry powder containing aluminium silicate that may be partially dehydroxylated during the grinding-drying operation can be obtained. The degree of dehydroxylation can be assessed by the reactivity in the “Chapelle” test, which consists in evaluating the quantity of CaO potentially consumable by the mineral material after a long time, hence defining the potential pozzolanic reactivity of the mineral addition. In this test, which is described by R. Largent in Bulletin de Liaison des Laboratoires des Ponts et Chaussées [journal of the laboratories of the French higher educational institute for civil engineering] No.93 (January-February 1978), 63-64, the mineral material and lime suspended in air are placed in contact for sixteen hours at close to the boiling point. The high temperature accelerates the pozzolanic reaction. After cooling, the amount of lime that has not reacted is determined. The result is expressed in g per 1 g of mineral material.
[0029] In order to achieve a high degree of dehydroxylation with a Chapelle test reactivity of at least about 0.7 to 0.8, the invention provides a step of heat treatment by transporting the dry powder in a hot gas stream at a temperature of from 600 to 850° C., for a time which is sufficient to achieve the desired degree of dehydroxylation, without the temperature of the particle reaching the zone for mineral conversion into mullite.
[0030] Analysis of the curves provided by DTA makes it possible to identify and quantify precisely both the reaction temperatures (determination of the minimum and maximum temperatures) and the kinetics of kaolin conversion into metakaolin, which is useful for determining according to the invention the pairing of temperature_transport time of the kaolin in powder form. The temperature of the hot gas determines (by using the DTA results) the time of transport (contact between the gas and the powder) which is necessary for converting the kaolin into metakaolin. For instance, in the case of a kaolin which was studied, the transport time needed to achieve 80% dehydroxylation is 13 seconds with a temperature of 600° C., whereas it is advantageously reduced to 0.1 s with gases at about 800° C. It is noteworthy that the heat treatment conditions of the elementary kaolin particles when placed in a dilute flow are substantially different from those which are produced in measuring instruments of the DTA type, where the sample is placed in small crucibles. This geometrical arrangement is also modified by the presence of a relative humidity in the crucibles of the equipment which is greater than that prevailing in the dilute flow.
[0031] The powder which is to be subjected to the hot treatment may be treated directly after the disaggregation, if the latter is carried out on the site of the heat treatment, or alternatively after a step of intermediate storage on site or in a separate installation for preparation of the powder.
[0032] In the former case, it is possible to recover the powder with the hot gas stream when it leaves the disaggregation, then to transport the powder through the rest of the hot treatment, with optional supply of additional heat in the form of an auxiliary hot gas stream or other heating means, in order to raise the gas to a temperature ranging from 600 to 850° C.
[0033] In the latter case, the powder is introduced into a second hot gas stream at a temperature of from 600 to 850° C.
[0034] In either variant, the temperature of the hot gas may advantageously be controlled during the transport of the dry powder. The control may consist in imposing a temperature gradient on the gas and the powder, or, conversely, in keeping the temperature of the hot gas constant during the transport of the dry powder.
[0035] At the end of treatment, the dehydroxylated dry powder may be recovered by various means, in particular by filtration.
[0036] The invention also relates to an installation for the dehydroxylation treatment of aluminium silicate, characterised in that it includes a conduit supplied with a hot gas stream at a temperature ranging from 600 to 850° C., means for introducing a dry powder containing aluminium silicate into the conduit, and means for transporting the dry powder in this conduit.
[0037] According to other characteristics:
the installation comprises means for comminuting a hydrated base paste containing aluminium silicate into fragments, a grinder-dryer which disaggregates the fragments of base paste by mechanical action in the presence of a hot gas at a temperature ranging from 500° C. to 800° C., and means for collecting a dry powder downstream of the grinder-dryer; the grinder-dryer includes a grinding zone with grinding components and passages for the hot gas in the said grinding zone; the grinding components comprise at least two parallel discs carrying fingers projecting on their opposing surfaces, and in that the passages for the hot gas are the spaces between the fingers of the discs; the installation comprises separation means, such as a cyclone, at the outlet of the grinder-dryer; the installation comprises means for intermediate storage between the grinder-dryer and the conduit; the conduit is supplied with hot gas by a burner whose flame is contained outside the conduit; the conduit is equipped with external heating means, such as electrical heating elements and/or a heating jacket; the heating means consist of at least one intake for a gas which, by combustion at a wall of the installation, makes it possible to maintain a wall temperature of close to 800° C. the installation comprises, downstream, means for collecting powder by filtration.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] Other details and characteristics of the invention will emerge from the following detailed description of an exemplary embodiment of the invention, which is provided with reference to the appended drawings, in which:
[0048] FIG. 1 represents a diagram of an installation according to the invention;
[0049] FIG. 2 represents a schematic sectional view of a grinder-dryer suitable for forming part of the installation in FIG. 1 ;
[0050] FIG. 3 presents in detail the grinding components of the grinder-dryer in FIG. 2 .
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0051] In this example, the process according to the invention is used to treat kaolin clay, in order to convert aluminium sulphate into metakaolin.
[0052] To that end, the installation in FIG. 1 may be used. It should be pointed out that the representation in FIG. 1 is schematic, that the elements are not represented to scale, and that it does not limit the invention in any way, in particular as regards the arrangement of the various stations or the disposition or the orientation of the lines for circulating the materials.
[0053] This installation essentially comprises a clay storage hopper 1 , a comminuter 2 , a grinder-dryer 3 , optionally a separation cyclone 4 , optionally a storage container 5 , a transport conduit 6 , a cooling station 7 and a powder collection filter 8 .
[0054] The clay contained in the hopper 1 is in the form as it is produced when extracted from the quarry, generally in the form of blocks of a hydrated base paste whose dimensions may be as much as about ten centimetres. In the initial state, it has a water content which may range, for example, from 15 to 30% by weight.
[0055] The comminuter 2 delivers fragments of base paste with reduced dimensions, in particular of the order of several centimetres, into the grinder-dryer 3 , for example by means of a feed screw.
[0056] The grinder-dryer 3 is supplied with a hot gas stream produced at 9 by a burner 10 and a fan 11 , the stream being transported to the grinder-dryer through a conduit 12 . The flame of the burner 10 is regulated so that the temperature of the hot gas stream in the conduit 12 is of the order of from 500 to 800° C., preferably of the order of from 600 to 750° C., and in particular of the order of from 650 to 700° C.
[0057] The fragments of base paste are introduced into the hot gas stream at 13 with a rate which is controlled, for example, by the rotation of the screw, just before the conduit 12 meets the grinder-dryer 3 .
[0058] The disaggregation step will be understood more clearly with reference to FIGS. 2 and 3 , which respectively represent a type of grinder-dryer that can be used according to the invention, seen in section on a vertical plane in the axis of the line of the part of the installation represented at the bottom in FIG. 1 , and a detail of this grinder-dryer seen in exploded perspective. This type of grinder-dryer is marketed, in particular, by CMI-HANREZ.
[0059] The grinder is essentially composed of an enclosed space 14 , with a shaft 15 turning inside, which is driven by schematically indicated means 16 and which carries at least one disc 17 provided with at least one series of fingers 18 that project on at least one plane face of the disc and are preferably arranged in a ring around the periphery of the disc 17 . The enclosed space includes two disc-shaped walls 19 , 20 which are parallel to the disc 17 and which, on their surface opposing the plane faces of the disc 17 , carry at least one series of fingers 21 , 22 that are arranged in a ring around the periphery of the discs 19 , 20 . The series of discs are arranged concentrically, and their length is chosen so as to form chicanes between the fingers of two neighbouring series.
[0060] During operation, the rotation of the disc 17 drives the fragments 23 of base paste towards the periphery of the enclosed space 14 . On the first face of the disc 17 , the fragments pass through the chicanes formed between the fingers 18 and 22 , then they pass along the periphery of the enclosed space 14 towards the other face of the disc 17 and, on the other face of the latter, they pass through the chicanes formed between the fingers 18 and 21 . The effect of this path between the grinding fingers, which are very close together, is to knead or triturate the clay paste.
[0061] The hot gas stream 24 follows the same path, which is indicated by the arrows, and it envelops and penetrates the fragments of base paste, with a considerable surface area for exchange between the hot gas and the paste. This large exchange surface area permits very rapid, almost immediate evaporation of the water of hydration of the clay, which is progressively separated by attrition into particles of smaller and smaller size.
[0062] In the disc-shaped wall 19 , a diaphragm 25 is arranged which permits the particles of small size to leave the enclosed space 14 , whereas particles with larger dimensions are returned towards the chicanes in order to continue the disaggregation by attrition. It is therefore possible to regulate the device in order to recover, downstream of the diaphragm 25 , a powder 26 whose particle size distribution is the natural particle size of the clay platelets. Typically, the powder 26 has dimensions of less than 100 μm, and it may even comprise at least 95% of particles with a dimension of less than 40 μm.
[0063] At this stage, the powder generally no longer contains more than from 0 to 1% by weight of water. It has a lime reactivity, according to the Chapelle test, which is substantially unchanged in relation to the initial stage, generally less than 0.5 g per 1 g of pozzolan.
[0064] The powder 26 and the gas stream 27 , which has been cooled during the disaggregation operation (its temperature may fall to 100° C., but needs to be kept above its dew point) are recovered via a conduit 28 , which may be directed towards a cyclone for optionally separating the particles of the powder as a function of their size, for example in order to remove grains of sand or the aggregated particles with a dimension of more than 100 or 40 microns.
[0065] The powder 26 transported by the gas stream 27 may be stored at 5 , after discharge of the transport gas, or may be sent directly to the heat treatment stage which follows.
[0066] In FIG. 1 , the powder is taken from the silo 5 and conveyed via a conduit 29 , for example in a carrier gas stream, towards the transport conduit 6 in which a gas stream 30 produced by a burner 31 circulates, the said burner being located upstream of the conduit 6 so that the flame of the burner cannot extend into the zone where the powder is introduced. The flame of the burner 31 is regulated so that the temperature of the hot gas stream 30 in the conduit 6 is of the order of from 600 to 850° C., preferably of the order of from 600 to 800° C. The hot gas may be a combustion gas, as is the case here, but it could also be any other type of gas, air or the like, which is heated by any known means.
[0067] In order to disturb the thermal equilibrium in the conduit as little as possible, the powder may be conveyed into the conduit 29 by a hot gas stream.
[0068] The conduit 6 may be equipped with means for control and regulation of the temperature of the gases, for example in order to impose a temperature gradient along the conduit or, conversely, to keep the temperature within a small variation range. The conduit 6 will advantageously be provided with heating means, because the kaolin dehydroxylation reaction is endothermic and lowers the temperature of the treatment gas, and therefore that of the particles.
[0069] Hence, the conduit represented in FIG. 1 is equipped with a heating jacket 32 , which may consist of a double sleeve inside which a heating fluid circulates, in particular combustion gases. As a variant or in addition, electrical heating means may be provided.
[0070] Since the dehydroxylation reaction is endothermic, it may be beneficial in terms of thermal efficiency to provide an energy input into the particles transported in the flow. This energy input may be provided, in particular, by electrical radiation or by gaseous or liquid combustion of a fuel. (If a gas is used, it will spontaneously ignite in contact with the wall.)
[0071] The conduit is advantageously provided with external insulation (not shown) to counteract heat losses.
[0072] The conduit 6 is arranged in any known way that permits fluidisation of the powder particles, preferably vertically, and it is dimensioned so as to permit a sufficient residence type of the powder with the gas stream 30 . This dimensioning depends, inter alia, on the material which is being treated, the particle size of which dictates the fluidisation rate, which is the minimum speed of the gas stream 30 for transporting the powder throughout the conduit. As an illustration, the speed of the gas 30 for treating clay may be of the order of 10 m/s.
[0073] The residence time of the powder in the conduit actually depends on the desired degree of dehydroxylation and the temperature of the gas 30 , and it will therefore be adapted on a case-by-case basis by the person skilled in the art. A residence time—between 0.1 and 0.2 s at 800° C. is generally sufficient to increase the Chapelle test value significantly, advantageously by at least 0.1 g, and in particular by approximatively 0.7 g to 0.8 g/g of pozzolan.
[0074] On the basis of a kaolin clay which, when leaving the grinder-dryer, already had a capacity to bind lime according to the Chapelle test with a reactivity, for example, of the order of 0.5 g, it was possible to verify that the treatment in the conduit 6 permits the dehydroxylation to be enhanced, increasing the reactivity of the powder.
[0075] The kinetic of the pozzolanic reaction (PR) of the dehydroxylated kaolin clay (metakaolin ) has been determined according to following tests protocol.
[0076] A pure paste is prepared by mixing equal quantities of metakaolin and calcium hydroxide with water (weight of water/weight of solids is 0.68).
[0077] The paste obtained is cast in 4×4×4 cm cubes and cured at 100%H.R. at 20° C., for 3 and 7 days.
[0078] After a 3-day and 7-day cure, hardened samples are ground and subjected to Differential Thermal Analysis(DTA) where the surface area of Ca(OH) 2 dehydration peak is measured.
[0079] Besides, the surface area of the Ca(OH) 2 dehydration peak is measured by DTA for a 1:1 mixture of Ca(OH) 2 and an inert component SiO 2 (reference).
[0080] The ratio between both peak areas indicates the amount of Ca(OH) 2 consumed by the pozzolanic reaction. The higher the amount of Ca(OH) 2 consumed, the higher the ratio between both peak areas. The pozzolanic reactivity is calculated as:
PR (%)=((peak area of reference−peak area of material analysed)/peak area of reference)×100
[0081] This method of measurement, which is well known by the person skilled in the art, was developed at Institut National de Sciences Appliquees de Lyon—France—(INSA-Lyon) by Prof. Jean Pera and Prof. Jean Ambroise (see for instance Jean Ambroise Phd Thesis—1984 —Elaboration de Liants Pouzzolaniques à Moyenne Température et Etude de leurs Propriétés Physico-Chimiques et Mécaniques ).
[0082] The metakaolin, as prepared above, exhibits a pozzolanic reactivity of 62% after a 3-day cure, and of 94% after a 7-day cure. For a comparison, a metakaolin was prepared from the same raw material but calcinated in a static process. The reactivity is as shown in table 1, along with the reactivity of some commercially available metakaolins;
[0083] The commercial metakaolin studied are: Metakaolin B: Metastar 501 from IMERYS
[0084] Metakaolin C: Polestar 400 from IMERYS
[0085] Metakaolin D: Glomax LL from IMERYS
[0086] Metakaolin E: Metamax from ENGELHARD
TABLE 1 3-day 7-day Chapelle reactivity reactivity Test Value PR (%) PR (%) (mg GaO/g MK) Kaolin A calcined according 62 94 746 to the invention Kaolin A calcined according 30 86 710 to a static calcination process Metakaolin B 19 82 785 Metakaolin C 0 29 397 Metakaolin D 21 25 269 Metakaolin E 39 91 828
[0087] The metakaolin calcined according to the invention has a higher early-age pozzolanic reactivity than the other metakaolins, including the metakaolin calcined by static process from the same kaolin source.
[0088] It can be noted that the metakaolin calcined according to the invention has also a higher early-age pozzolanic reactivity than the metakaolins giving the highest Chapelle values, that means, highest pozzolanic reactivity potential. (Metastar 501 from IMERYS and Metamax from ENGELHARD).
[0089] The treatment in the conduit 6 may also be used to impart reactivity to a material which is initially very unreactive.
[0090] Therefore, in another test, a kaolin powder marketed by the company SOKA under the brand name SIALITE, whose initial Chapelle reactivity is very low (of the order of 45 mg of CaO per gram), was treated using a gas at 800° C. forced with a speed of 10 m/s through a 1.7 m long conduit, the degree of dehydroxylation being such that the Chapelle reactivity was 307 mg per 1 gram of material and, for a 5.1 m long conduit, a reactivity of 0.7 g per 1 gram of dry material was achieved.
[0091] When leaving the conduit, the powder 26 and the gas 30 are still at an elevated temperature, and it may be desirable to cool them before proceeding with the separation of the powder. This is why the installation comprises a heat exchanger 7 connected to the outlet of the conduit 6 , upstream of the filter 8 for separating the dehydroxylated powder.
[0092] A hot gas recycling circuit, with the possibility of re-heating, may be provided in order to improve the thermal or energy efficiency of the installation.
[0093] Although it has been described more particularly with reference to the treatment of a kaolin clay, the invention is generally applicable to the treatment of any material containing aluminium silicate.
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The invention concerns a dehydroxylated aluminium silicate-based material exhibiting a faster pozzolanic reactivity, characterized in that the amount of reacted calcium hydroxide measured by the pozzolanic reactivity (PR) after a 3-day cure is at least 50%. In a process and an installation for dehydroxylation treatment of aluminium silicate, particles containing aluminium silicate are exposed to a temperature of at least 500° C. The particles are in the form of a dry powder, and the dry powder ( 26 ) is optionally transported in a gas stream ( 30 ) at a temperature ranging from 600 to 850° C., for a time which is sufficient to achieve the desired degree of dehydroxylation. The powder may be obtained from a hydrated base paste by reducing the base paste into fragments ( 23 ), and by disaggregating the fragments ( 23 ) of base paste by mechanical action (at 3) in the presence of a hot gas ( 24 ) at a temperature ranging from 500° C. to 800° C., in order to form the dry powder ( 26 ).
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CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation-in-part application of prior application Ser. No. 14/623,464, filed on Feb. 16, 2015, now pending, the patent application identified above is incorporated here by reference in its entirety to provide continuity of disclosure.
FIELD OF THE INVENTION
[0002] The present invention generally relates to an indoor automation and control system and method thereof using a RFID-to-Bluetooth adapter device and, more particularly, to automation and control method of various indoor electrically-connected devices in a room unit using a smartphone or wearable device together with the RFID-to-Bluetooth selective adapter mounted on a RFID door lock of a door of the room unit.
BACKGROUND OF THE INVENTION
[0003] In today's door access control systems, there are many places that have adopted RFID doorlocks for improved door access control functions. According to a survey of a physical access control market research, more than 70% of the end-users and 80% of industry respondents believe that in the next 3 to 5 years, hope to use mobile phones, key cards, smart label or alternative devices to replace conventional locks and keys. The survey is further proof that the market will usher in a major smart lock revolution.
[0004] However, the conventional smart door locks are typically in the form of RFID doorlocks or Bluetooth activated smart doorlocks. If someone already has a RFID doorlock, it would not be possible to easily upgrade the existing RFID doorlock to that of a Bluetooth smart doorlock. In other words, the existing RFID doorlock has to be completed removed, while replaced by a new Bluetooth smart doorlock installed on the door (for replacing the previous RFID doorlock altogether). Meanwhile, after installation of the new Bluetooth smart doorlock, the previous RFID tags being used as keys for opening the previous RFID doorlock can no longer work on the new Bluetooth smart doorlock, so that the new Bluetooth smart doorlock must be limited to be activated only by Bluetooth capable mobile devices.
[0005] In the hospitality industry and for hospitality accommodation establishments, such as hotels, motels, bed and breakfast, resort condos, and Airbnb® lodgings etc, the use of RFID smart door locks and indoor automation and control systems for performing various electrical controls and monitoring are in high demand in recent years, due to the fact that both of the smart door lock and the automation and control system adds to the convenience and enhancement for the overall stay experience of the rented room by the room occupant. For example, a hotel room is typically equipped with power outlets or electrical outlets, HVAC (heating, ventilating, and air conditioning) systems with electrical connections typically operating in one or more electrical circuits, lights that are typically come in two forms, namely, pre-wired lighting fixtures that runs on one or more circuitry with independent power on/off control switches, and independently detachable or moveable lighting fixtures that have electrical plugs plugged into power outlets inside the room for independent power provisioning and on/off control. Other automation and control systems such as for audio/video units, window curtain and blinds opening and closing, security system, dimmer for all lighting, etc can also be incorporated (especially for more luxury or 5-star level of hospitality accommodation establishment). As a result, the room occupant typically finds it to be an enjoyable and delighted experience to be able to conveniently control and automate different room settings and functionalities using just a smartphone.
[0006] Therefore, there is a need in providing a more integrated and efficient automation and control solution for the hospitality industry that would be applicable to a rental unit with a RFID door lock installed, and to be able to provide Bluetooth control capability, along with improved overall door access control functionality, and improved convenience and enhancement of the overall stay experience of the room unit by the room occupants.
SUMMARY OF THE INVENTION
[0007] The present invention provides an integrated short range and long-range automation and control system for indoor applications using a RFID-to-Bluetooth selective adapter.
[0008] The present invention provides the short range to be operating without internet connection, while the long-range to be operating under internet connection. The short-range automation and control can also be called near-range automation and control (without using internet connection), and the long-range automation and control can also be called distant-range or far-range automation and control (requiring to have internet connection).
[0009] The present invention provides the RFID-to-Bluetooth selective adapter to include capabilities that allow an administrator to remotely control the RFID door lock, obtain historical data for door entry event logs of guests into an access-controlled space, and to provide automated provisioning and controlling of power on, power off, and electrical power usage history recording functions.
[0010] The present invention provides a gateway device that is configured to have internet connection capability, for allowing users to remotely unlock or lock a smart doorlock using the gateway device, send notifications of door unlock events back to a cloud server, and being able to remotely control electrical or electronic devices in a room under short-range (operating mode) or long-range (operating mode).
[0011] The present invention provides three detection methods for determining whether any occupant is located or disposed inside a confined space/region, and if not, can automatically or manually power off the electrical power supply/input to the confined space/region.
[0012] The present invention provides a current sensor, and through the use of the current sensor installed along the power supply circuit for the confined space/region, the user can measure and assess electric power consumption rate for the confined space in real-time.
[0013] The present invention provides further enhancements to the automation and control solution for indoor applications for the hospitality industry thereby adding to the convenience and enhancement of the overall stay experience of a room unit by offering a plurality of online services and offline services that can be implemented and activated upon unlocking or locking of the smartlock which are installed on doors using a smartphone or wireless wearable device equipped with Bluetooth capability.
[0014] The present invention also provides further enhancements, benefits, and/or advantages to the automation and control solution for indoor applications in various other usage scenarios, such as for personal homes, public facilities, and commercial office buildings. Because doors are typically main access points to various confined regions, such as a personal home, a library, a hotel room, etc, thus by controlling the locking and unlocking of the smart door lock of the doors, automation and control of online and/or offline services are thereby also achieved. Such online or offline services can be, for example, a parent can know in real-time that a particular child has came back home safely, or that the hotel management or personnel can know whether or not a guest has entered the rented room; upon entry of a main entrance door (equipped with the smart doorlock and the RFID-to-Bluetooth selective adapter) for a condominium complex, the resident through the unlocking of the smart door lock can gain access to the latest up-to-date information broadcast for residents of the condominium complex, or receive notification of monthly condo fee that is due, etc. Upon entering a room, the occupant can conveniently turn on or turn off electrical power to any connected electrical or electronic devices, such as lamps, lights, air conditioning unit, heater, radio, stereo, television, wall outlet, power outlet, etc, as well as enabling capability for viewing of a readily instantly available display control panel on the smartphone that is automated to perform remote control of the powered up or powered off electrical or electronic devices, without having to find each of the corresponding power switches and remote controls for performing the same control step. Upon the occupant entering into the confined space/room via the unlocking of the smart door lock, the power consumption rate data can be collected under the responsibility or assignment of the occupant, so that the administrator or property manager/owner can charge or assess discounts based on actual power consumption amount of that occupant. Upon exiting the room by locking the smart door lock, the APP can query the occupant as to whether or not it is necessary to turn off all remaining powered on electrical or electronic devices inside the room or the confined region, thereby achieving energy savings.
[0015] According to an aspect of the present invention, upon entry of a hotel room or a unit for any hospitality accommodation establishments that is installed with an energy saving key card holder, the energy saving key card holder requires a properly authenticated card to be inserted therein so as to allow provisioning of electrical power to the respective connected units. The use of the RFID-to-Bluetooth selective adapter of present invention together with the smartphone, can thereby eliminate the need of inserting of the key card into the energy saving key card holder for allowing continued power on of electrical or electronic devices while the occupant is inside the room.
[0016] According to one embodiment of present invention, the conventional energy saving key card holder can then be modified to allow control by a gateway device, and the energy saving key card holder can replaced by a relay controller. Unlike the conventional activating signal which is achieved by an insertion of a properly authenticated key card into the energy saving key card holder, the gateway device of present invention performs the same function in lieu thereof. The gateway device and the relay controller can be coupled together in a wired or wireless manner. For rooms or suite units (comprising of multiple number of rooms) that are difficult to have electrical or cable wiring installed, wireless connection between the gateway device and the relay controller can be an effective solution without excess modification required.
[0017] According to one embodiment of the present invention, a relay controller and a current meter can be integrated and installed within one physical module or device. The gateway device, the current meter and the relay controller can all be installed in the energy saving key card holder. Readings from the current meter can be sent to the gateway device, which is then stored in the cloud in a server.
[0018] According to one aspect of the present invention, three detection methods are provided for determining whether any occupant is located or disposed inside a confined space or room as follow:
First detection method: the gateway device continuously broadcast beacon signals, and upon not detecting any reply beacon signal from the smartphone of the occupant, then the occupant is assessed as being possibly departing or left the confined region. At this time, the APP can launch a query to the occupant to ask if he/she is still within the confined region, and also whether or not turn off all electrical connections to save power, and if so, transmitting the power off signal to the gateway device via internet connection. Second detection method: the RFID-to-Bluetooth selective adapter is configured with a g-sensor or a vibration sensor therein for detecting door opening, such as for example, if the door opening motion is detected while the switch on the RFID-to-Bluetooth selective adapter is not being depressed/pressed, then the occupant is reasoned to have been exiting or left the room. Third detection method: by installing an occupancy sensor as taught in http://en.wikipedia.org/wiki/Occupancy_sensor so as to be detecting occupancy of a space by an occupant thereof, and upon not detecting any reflected signal changes, thereby automatically turning off the electrical devices.
[0022] According to another aspect of the present invention, the internet connection capabilities of the gateway device includes the following:
a. One or more of WiFi, 3G/4G, Long Range (LoRa), Ultra Narrow Band (UNB) wireless communication protocols can be adopted for performing and handling the internet connection; b. if WiFi is already present within the confined region/room, the gateway device can directly be connected to the WiFi and WiFi access points (AP) to achieve internet connection capability; c. if WiFi is not already present within the confined region, the gateway device can be connected to nearby base station via a 3G/4G baseband transmission module to achieve internet connection capability; d. because the data transmission rate of the gateway device itself is relatively low, it is more cost effective to utilize LoRa or UNB wireless communication technologies. The LoRa and UNB is a physical transmission layer (100 bps-5k bps) with a low baud rate, and can be transmitted under low power consumption. The transmission distance under line-of-sight condition can reach several kilometers. Just one LoRa or UNB access point needs to be installed or disposed within the confined space for providing space management applications or utilities;
e. when the gateway device is not able to connect to internet, the short-range control and automation functionalities including door opening, power provisioning, power off of electrical outlet can still maintain normal operation, just that the long-range control and automation functionalities would be not be activated or operating.
[0028] According to another aspect of the present invention, short range/ near-range (without internet connection) or long-range/distant-range (requiring internet connection) power on/off management and control (including turning power on and turning power off) of electrical or electronic device disposed in the confined region or room or entire house/suite/condo unit (comprising of multiple number of rooms) can be achieved and provided, even in real-time.
[0029] According to another aspect of the present invention, users or occupants can use smartphones or wearable devices' Bluetooth wireless communication capability to be connected to the gateway device to issue power on or power off signals to connected electrical devices. As a result, users or occupants can remotely control the power on and power off (power on/off management) using the long-range control method via internet connection, which can be performed wirelessly to transmit the control packet through the WiFi access point to the gateway device, which then issue the control command.
[0030] The present invention provides a RFID-to-Bluetooth selective adapter according to an embodiment of present invention for upgrading a conventional RFID doorlock to become capable of operating in two modes simultaneously, namely operating in RFID mode or Bluetooth mode, for allowing entry access by using conventional RFID key tags or Bluetooth equipped smartphones and mobile wearable electronic devices, respectively.
[0031] The present invention discloses a RFID-to-Bluetooth selective adapter which functions as a bridge or interface device between a RFID reader equipped device, which can be a RFID door lock, and wireless mobile electronic devices, which can be a smartphone, a tablet device, or a electronic wearable device, operating under Bluetooth or Bluetooth smart capability.
[0032] The RFID-to-Bluetooth selective adapter of present invention can allow RFID reader equipped devices/RFID door lock that are capable of only being activated by RFID tags or key cards to be adapted for usage under Bluetooth wireless communication protocol by Bluetooth equipped wireless mobile electronic devices.
[0033] The RFID-to-Bluetooth selective adapter of present invention does not negatively affect the original RFID door lock functionalities between the RFID door lock and the conventional RFID tags, but at the same time, allows for the added or extended capability of operating as well under Bluetooth environment.
[0034] The RFID-to-Bluetooth selective adapter of present invention can operate under a Bluetooth protocol version called Bluetooth Low Energy (BLE), which is a wireless personal area network technology configured for establishing device-to-device communications that can operating under very low power consumption.
[0035] The RFID-to-Bluetooth selective adapter of present invention can be adapted and configured for usage alongside existing or conventional RFID doorlock, for providing Bluetooth capability, so that smartphones and wearable wireless devices can also perform functions similar to that of the RFID tags (RFID transponder) for activating the RFID door lock.
[0036] An application of the RFID-to-Bluetooth selective adapter of present invention would be for a RFID doorlock which is used as a part of a smart doorlock system.
[0037] Upon installation of the RFID-to-Bluetooth selective adapter on the sensor area of the RFID reader equipped device/ i.e. the RFID doorlock, a smartphone or a wearable device or a tablet device (with BLE or Bluetooth smart capability) can be used to activate or lock/unlock the RFID doorlock.
[0038] By using the RFID-to-Bluetooth selective adapter of present invention, the conventional RFID doorlock functionalities can still be maintained, and at the same time, further providing added Bluetooth capability.
[0039] As a result, the RFID-to-Bluetooth selective adapter of present invention serves as an upgrade option to the conventional RFID doorlock, while having advantage such as being cost effective and easy to upgrade.
[0040] The RFID-to-Bluetooth selective adapter of present invention can be used, for example, in door or area access control situations, such as in private homes, day or monthly rental apartments, hotel rooms, and public space and resource usage management, community mail box, elevators, smart security cabinet, and is not limited to these applications only.
[0041] The user can set up and generate a certificate for authentication to the respective authenticated mobile phone upon authentication at a cloud based authentication server, thereby eliminating the need for having to retrieve or obtain any physical RFID key tag.
[0042] In embodiments of present invention, an APP configured to provide wireless Bluetooth low energy (BLE) smart door lock remote control operations, and to provide with an user account for the user on the smartphone to register the RFID-to-Bluetooth selective adapter as an authenticated trusted device in a cloud based authentication server.
[0043] In embodiments of present invention, the RFID-to-Bluetooth selective adapter can be directly attached or disposed at close proximity to a sensor area of the RFID reader of the smart door lock.
[0044] In embodiments of present invention, the APP can be used to set up access rights and permissions for the authenticated RFID-to-Bluetooth selective adapter, the cloud based authentication server can issue a digital certificate to the smartphone to be transmitted to the RFID-to-Bluetooth selective adapter, or the digital certificate can be issued instead through a third party trusted certificate authority. Thus, the APP can be configured to provide wireless access management and control of the RFID reader equipped device using the RFID-to-Bluetooth selective adapter via BLE communications.
[0045] A RFID tag or a RFID key card described herein can also be called a RFID transponder.
[0046] In embodiments of present invention, a hospitality accommodation establishment includes hotels, inns, service apartments, resort villas, motels, bed and breakfast, and Airbnb® lodgings, but is not limited to just these.
BRIEF DESCRIPTION OF THE DRAWINGS
[0047] The present invention will become more readily apparent to those ordinarily skilled in the art after reviewing the following detailed description and accompanying drawings, in which:
[0048] FIG. 1 shows a block diagram of a short range and long-range indoor automation and control system in accordance to a first embodiment of present invention.
[0049] FIG. 2 shows a flow chart of a configuration method for a first time initial configuration of a RFID-to-Bluetooth selective adapter of the first embodiment using an APP.
[0050] FIG. 3 shows a flow chart of an operating method of the RFID-to-Bluetooth selective adapter of the first embodiment.
[0051] FIG. 4 shows a flow chart of a short-range operating method for the indoor automation and control system of an embodiment of present invention.
[0052] FIG. 5 shows a flow chart of a long-range operating method for the indoor automation and control system of an embodiment of present invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0053] The present invention will now be described more specifically with reference to the following embodiments. It is to be noted that the following descriptions of the embodiments of this invention are presented herein for purpose of illustration and description only. It is not intended to be exhaustive or to be limited to the precise form disclosed.
[0054] As shown in FIG. 1 , a short range and long-range indoor automation and control system 50 is provided according to a first embodiment of present invention. The short range and long-range indoor automation and control system 50 includes a Bluetooth smart equipped wireless mobile electronic device 700 , such as a smartphone or a wearable electronic device, a RFID-to-Bluetooth selective adapter 100 , a RFID Lock 30 , a WiFi access point 600 that is connected to the internet, a current meter 400 (optional), a gateway device 200 , a relay controller 300 , and a main electrical power switch 500 . The RFID-to-Bluetooth selective adapter 100 is installed or attached onto the RFID lock 30 . The RFID lock 30 has a RFID reader therein, and is mounted onto the door. The RFID-to-Bluetooth selective adapter 100 of the illustrated embodiment can be the RFID-to-Bluetooth selective adapter ( 10 ), the RFID lock 30 can be the RFID reader equipped device ( 17 ) which are both described in parent application application Ser. No. 14/623,464. The short range automation and control mode operates without internet connection, the long-range mode operating under internet connection. The short-range can also be called near-range (without using internet connection), and the long-range can also be called distant-range or far-range (requiring to have internet connection). The conventional energy saving key card holder (not shown) that are typically found in hotel rooms can be modified to allow control by the gateway device 200 , and the energy saving key card holder can be replaced by the relay controller 300 . The relay controller 300 can be a programmable relay controller. Unlike the conventional activating signal which is obtained by means of an insertion of a properly authenticated key card into the energy saving key card holder, the gateway device 200 provides the same activating signal through different authentication methods in the first embodiment of present invention. The gateway device 200 and the relay controller 300 can be coupled together in a wired or wireless manner. For rooms that are difficult to have electrical or cable wiring installed, wireless connection between the gateway device 200 and the relay controller 300 can be an effective solution without excess modification required. According to one embodiment of the present invention, a relay controller 300 and a current meter 400 can be integrated and installed within one physical module or unit. In alternative embodiment, the gateway device 200 , the current meter 400 and the relay controller 300 can all be installed in an energy saving key card holder (but without actually utilizing the conventional functionality of the energy saving key card holder itself). For instance, the conventional energy saving key card holder requires to have a properly-authenticated RFID card to be inserted therein so as to allow provisioning of power to the respective connected electrical devices. The use of the RFID-to-Bluetooth selective adapter 100 together with the smartphone 700 in the illustrated embodiment, can thereby eliminate the need of inserting of the properly-authenticated RFID key card into the energy saving key card holder for allowing continued power on of electrical or electronic devices while the occupant is inside the room. In the illustrated embodiment, there is no need to place any RFID key card or smartphone on or near the gateway device 200 or the relay controller 300 .
[0055] Readings from the current meter 400 can be sent to the gateway device 200 , which is then stored in the cloud in a server on the internet. In the illustrated embodiment, the internet connection capabilities of the gateway device 200 includes the following: one or more of WiFi, 3G/4G, Long Range (LoRa), Ultra Narrow Band (UNB) wireless communication protocols can be adopted for performing and handling the internet connection; if WiFi is already present within a confined region/space or a room (not shown), the gateway device 200 can directly be connected to the WiFi access points (AP) 600 to achieve internet connection capability; if WiFi is not already present within the confined region, the gateway device 200 can be connected to nearby base station (not shown) via a 3G/4G baseband transmission module (not shown) to achieve internet connection capability; because the data transmission rate of the gateway device 200 itself is relatively low, it is more cost effective to utilize LoRa or UNB wireless communication technologies. The LoRa and UNB is a physical transmission layer (100 bps-5k bps) with a low baud rate, and can be transmitted under low power consumption. The transmission distance under line-of-sight condition can reach several kilometers. Just one LoRa or UNB access point needs to be installed or disposed within the confined space for providing space management applications or utilities; when the gateway device 200 is not able to connect to internet, the short-range functionalities including door opening, power provisioning, power shut off can still maintain normal operation, just that the long-range functionalities would be not be activated or operating. Using the short range and long-range indoor automation and control system 50 of the first embodiment, short range/near-range (without internet connection) or long-range/distant-range (requiring internet connection) power on/off management and control (including turning power on and turning power off) of electrical or electronic device disposed in the confined region or room can be achieved and provided by power on (turn on) or power off (turn off) of a main power switch, even in real-time. In addition, users or occupants can use smartphones or wearable devices' Bluetooth wireless communication capability to be connected to the gateway device 200 to issue power on or power off signals to connected electrical devices. As a result, users or administrator or property manager/owner or occupants can remotely control the power on and power off (power on/off management) using the long-range control method via internet connection, which is performed wirelessly to transmit the control packet through the WiFi access point 600 to the gateway device 200 , which then issue the control command.
[0056] In the illustrated embodiment for FIG. 1 , three detection methods can be provided for determining whether any occupant is located or disposed inside a confined space/room as follow: First detection method: the gateway device continuously broadcast beacon signals, and upon not detecting any reply beacon signal from the smartphone of the occupant, then all occupants are assessed as being possibly departing or left the confined region/room. At this time, the APP can launch a query to one occupant to ask if anyone is still within the confined region/room, and also whether or not turn off all electrical connections to save power, and if so, transmitting the power off signal to the gateway device via internet connection. Second detection method: the RFID-to-Bluetooth selective adapter is configured with a g-sensor or a vibration sensor therein for detecting door opening, such as for example, if the door opening motion is detected while the switch on the RFID-to-Bluetooth selective adapter is not being depressed/pressed, then all occupant is reasoned to have been exited out or left the room. Third detection method: by installing an occupancy sensor as taught in http://en.wikipedia.org/wiki/Occupancy_sensor so as to be detecting occupancy of a space by any occupant thereof, and upon not detecting any reflected signal changes, thereby automatically turning off the electrical devices. One or more of the above detection methods can be used in actual implementation.
[0057] Referring to FIG. 2 , a configuration method of the RFID-to-Bluetooth selective adapter 100 of the first embodiment is described for a first time initial configuration thereof using an APP to include the following steps:
[0058] In Step S 10 , the RFID-to-Bluetooth selective adapter is activated/turned on, to be entering into a setup mode, in which a product shipping packaging of the RFID-to-Bluetooth selective adapter contains a device serial number therein, which can a string of alphanumeric number or a QR code. The device serial number of the RFID-to-Bluetooth selective adapter can only been seen or read upon opening of the shipping packaging to remove the RFID-to-Bluetooth selective adapter, so that when sealed, the packaged RFID-to-Bluetooth selective adapter would not reveal the device serial number to any bystander.
[0059] In Step S 20 , a user can go to an APP store to download an APP that is configured to provide wireless access management and control of the RFID lock using the RFID-to-Bluetooth selective adapter via BLE communications. Upon opening the APP for the first time, an user account is required to be set for the user, and upon successfully setting up the user account on the smartphone, the device serial number is entered to register the RFID-to-Bluetooth selective adapter as an authenticated trusted device in a cloud based authentication server on the internet.
[0060] In Step S 30 , the RFID-to-Bluetooth selective adapter is to be directly attached or disposed at close proximity to the sensor area of the RFID reader of the RFID lock, and to launch or initiate the RFID reader to enter into a configuration mode for adding a new identification code/registration key of the RFID-to-Bluetooth selective adapter. The RFID reader is to read a signal for a identification code/registration key for a customized RFID transponder (not shown) of the RFID-to-Bluetooth selective adapter by sending out an interrogating signal to the RFID transponder (not shown) of the RFID-to-Bluetooth selective adapter so as to perform registering of the identification code/registration key for the RFID-to-Bluetooth selective adapter. The identification code/registration key is a an hexadecimal ID string of 16 bytes
[0061] In Step S 40 , the APP is used to set up access rights and permissions for the authenticated RFID-to-Bluetooth selective adapter, the cloud based authentication server can issue a digital certificate which is an encrypted digital file to the smartphone to be transmitted to the RFID-to-Bluetooth selective adapter, or the digital certificate can be issued instead through a third party trusted certificate authority. This digital certificate can be a perpetual certificate or a timed duration certificate.
[0062] Referring to FIG. 3 , an operating method of the RFID-to-Bluetooth selective adapter 100 of the first embodiment is described to include the following steps: In Step S 100 , when the user is approaching close by or at close proximity to the RFID lock, the RFID-to-Bluetooth selective adapter is energized by the interrogating signals from the RFID reader of the RFID lock (the RFID reader has an inductor coil which broadcast the interrogating signals) when the RFID lock, through the use of a proximity sensor, or the like, is able to sense the user located at close proximity thereof, which in turn, will allow the RFID-to-Bluetooth selective adapter to broadcast signals through Bluetooth or BLE, and the smartphone (or any wearable electronic device) in Bluetooth/BLE broadcast coverage range would then intercept the broadcast signal to be automatically awakened and activated.
[0063] In Step S 110 , the smartphone (or the wearable electronic device) transmits the digital certificate to the RFID-to-Bluetooth selective adapter via BLE to a Bluetooth module (not shown) inside therein, the RFID-to-Bluetooth selective adapter is to inspect as to whether the digital certificate is valid or expired or invalid. Without having any authenticated smartphone or wearable mobile device being properly configured by the smart doorlock remote control APP, or in other words, if the user is not using any smartphone or that the smartphone has yet to be installed with the APP, the user can still use a conventional RFID tag or RFID smart card to be placed on or above the sensor area of the RFID lock for performing proper access control usage (i.e. open or close the door, turn on and turn off the door lock).
[0064] In Step S 120 , upon successful authentication by the Bluetooth module, a switch (not shown) of the customized RFID transponder (not shown) inside the RFID-to-Bluetooth selective adapter is turned on by turning on the on/off switch of the customized RFID transponder in the RFID-to-Bluetooth selective adapter, so as allow the RFID reader (of the RFID lock) to interrogate and read the customized RFID transponder (not shown) inside the RFID-to-Bluetooth selective adapter.
[0065] In Step S 130 , upon successfully verifying or authenticating the ID string for the customized RFID transponder of the RFID-to-Bluetooth selective adapter, the RFID lock is activated. For the sake of power conservation, the RFID reader of the RFID lock would not be operating under continuously sensing mode of nearby EMF signals (typically operating under current of dozens of milliamps, mA), only when the RFID reader is placed in close proximity to the user, would then trigger activation of the RFID reader to perform EMF signal sensing by the RFID reader, in this manner, various sensing methods such as by infrared LED, ultrasonic sensing, microwave sensing, which are low-power sensing methods . . . (requiring current in the tens of microamps, uA) can be used. The energy from the EMF signals of the RFID lock can be used to power on the RFID-to-Bluetooth selective adapter, so that Bluetooth or BLE communication from the RFID-to-Bluetooth selective adapter can be established with the adjacent smartphone to perform two way communications using the APP providing wireless access management and control of the RFID lock through the RFID-to-Bluetooth selective adapter downloaded in the smartphone. Under typical operation, the power consumption of the RFID-to-Bluetooth selective adapter is about 5 microamps, or 5 uA.
[0066] Referring to FIG. 4 , a flow chart diagram showing a short-range operating method (which requires the download of an APP, and the gateway device not connected to the internet) for indoor automation and control system of an embodiment includes the following steps: In Step S 1100 , a button of the RFID-to-Bluetooth selective adapter (the RFID-to-Bluetooth selective adapter is disposed or adhered to a sensor area of the RFID door lock) is pressed down to initiate the door lock unlocking process; upon successfully authenticating that the digital certificate is valid using the smartphone or wearable device, the RFID door lock is then automatically unlocked. In Step S 1200 , the RFID-to-Bluetooth selective adapter, the smartphone or the wearable device automatically link or connect with the gateway device to activate a power supply to electrical and electronic devices that are connect to one or more electrical circuits configured for the confined region/room by turning on / power on a main power switch, in which the main power switch is connected to a plurality of electrical circuits configured for a plurality of power outlets, a plurality of lighting fixtures, and a plurality of HVAC units. In Step S 1300 , the smartphone can operate under Bluetooth mode to connect with the gateway device to thereby independently control the power supply of the power outlets/electrical outlets, the lighting level or intensity, the air conditioner or heater temperature (HVAC) settings, and the television remote control settings by independently controlling a plurality of WiFi smart plugs to power on or power off the power outlets, the lighting fixtures, and the HVAC units using the relay controller 300 . In Step S 1400 . upon detecting that all occupants to have been vacated or left the room or confined region for a specified period of time (2 minutes to 5 minutes), power outlets or electrical outlets in the room are automatically shut off by power off the main power switch; meanwhile before shutting off or power off, the gateway device will send a power off message to the smartphone, and if the smartphone is still situated or located within the room, the occupant can respond by acknowledging that power is still needed to be turned on, thus avoiding premature or accidental power shut off.
[0067] Referring to FIG. 5 , a flow chart diagram showing a long-range operating method (can be browser controller, thus does not requires the download of an APP, and the gateway device is required to be connected to the internet) for a hospitality accommodation establishment automation and control system includes the following steps: In Step S 2100 , a user can register online at the hotel (or any other hospitality accommodation establishment), and press a button on a specified webpage (the specified webpage is a secure webpage particular designed for the hotel guest to sign-on/sign-in during check-in or check-out) to unlock the room door of a rented room by the user. The room rental management cloud server then automatically sends the door lock unlocking signal to the gateway device in the rented room, the gateway device then automatically sends an unlocking command to the RFID-to-Bluetooth selective adapter for activating the RFID door lock to unlock. In Step S 2200 , the gateway device automatically activates and power on a main power switch which controls the power supply to the power outlets/electrical outlets, lighting fixtures, and HVAC units in the room. In Step S 2300 , the smartphone can operate under the specified webpage (the specified webpage is a secure webpage also particular designed for the hotel guest to perform various remote control commands during his or her stay in the room) using internet to control the power supply of the power outlets, the room rental management cloud server then sends one or more user input control signal to the gateway device in the rented room in real time to connect with the gateway device to thereby independently control the power supply of the power outlets, the lighting level or intensity, the air conditioner or heater temperature (HVAC) settings, and the television remote control settings by independently controlling a plurality of WiFi smart plugs to power on or power off the power outlets, the lighting fixtures, and the HVAC units using the relay controller 300 . In Step S 2400 , upon detecting that the user to have been vacated or left the room for a specified period of time (2 minutes to 5 minutes), the power outlets in the room are automatically shut off by power off the main power switch, meanwhile before shut off, the room rental management cloud server will send the power shut off message to the smartphone through the internet connection, and the user is able to turn on or turn off the power outlets and the main power switch, regardless of whether the smartphone is still located inside the room or not. In Step S 2500 , through the use of the current sensor, the occupant's electricity and energy consumption data can be measured and recorded, and can tabulate also historical record for room occupancy information, i.e. percent and duration of occupant staying inside the room versus outside the room, and communicating the historical record for room occupancy information to the room rental management cloud server for analysis and other usages.
[0068] One advantage of the embodiments of present invention include the ability to perform the short-range operating method of FIG. 4 and the long-range operating method of FIG. 5 in one of the following operating scenarios: (a) switching between short-range or long-range automatically based on internet availability or user preference; (b) switching between short-range or long-range manually by an administrator override command by a property owner or manager, when for example, an emergency situation is suspected of occurring at the confined location/space, and the property owner needs to shut-off the power from a distant remote location; (c) switching between short-range or long-range manually by an occupant, due to personal preference or signal quality issues.
[0069] Another advantage of the embodiments of present invention include the seamless integration of the smart door access control system together with indoor automation and control system into one convenient system for the enclosed space.
[0070] Another advantage of the embodiments of present invention include the automatic power on and power off of various connected electrical and electronic devices in the confined space upon entering and exiting the room through the door with the RFID lock, respectively, using the RFID-to-Bluetooth selective adapter and the smartphone/wearable device operating under Bluetooth upon secure authentication.
[0071] The RFID-to-Bluetooth selective adapter 100 of the first embodiment has reduced barrier to adoption due to the ease and convenience of being easily adapted to existing RFID doorlock systems, and requiring only limited expenditure to cover purchase cost, installation cost and labor. In addition, there is no need to discard the existing RFID doorlock system. Moreover, the physical size of the RFID-to-Bluetooth selective adapter is relatively small in comparison with some of the available Bluetooth smart lock on the market. Thus, the usage of the RFID-to-Bluetooth selective adapter allows typical home owner or property owner/manager to provision electronic keys securely by internet to any designated or chosen individual(s) under various different access control duration or schemes (i.e. the electronic key can allow for access for just one entry, for multiple entry within one day or specified days, for one month, etc.) so that the hassle of exchanging physical RFID keys are thereby avoided.
[0072] The RFID-to-Bluetooth selective adapter 100 through the usage of an APP configured in the smartphone/BLE equipped device 700 and a cloud based authentication server (not shown) can thereby provide various different access rights and settings for various users using the RFID smart door lock 30 .
[0073] In the above embodiments, the APP is configured to provide wireless access management and control of the RFID lock 30 using the RFID-to-Bluetooth selective adapter 100 via BLE communications, and to provide with an user account for the user on the smartphone to register the RFID-to-Bluetooth selective adapter as an authenticated trusted device in a cloud based authentication server. In addition, the APP is used to set up access permissions for the authenticated RFID-to-Bluetooth selective adapter, and transferring the digital certificate issued from the cloud based authentication server to the RFID-to-Bluetooth selective adapter. The user can use the APP to activate or deactivate the RFID reader equipped device using the RFID-to-Bluetooth selective adapter in real-time conveniently with or without internet connection. In a RFID doorlock usage scenario, the user can use the APP to open or close a door with a RFID smart doorlock mounted with a RFID-to-Bluetooth selective adapter in real-time conveniently with or without internet connection.
[0074] In the above embodiments, the compatible Bluetooth versions that can be used include Bluetooth, Bluetooth smart, Bluetooth smart ready, and/or other Bluetooth versions also included.
[0075] In the above embodiments, the terms “activated” and “activating” can have at least one of the following meanings: (a) for an entity to go from an “on” state to an “off” state when it is currently in an “off” state; or (b) for an entity to go from an “off” state to an “on” state when it is currently in an “on” state; (c) for a circuit to go from a closed circuit to an open circuit when it is currently in closed circuit state; or (d) for a circuit to go from a open circuit to an closed circuit when it is currently in open circuit state. Entity can be any of the component elements of the RFID-to-Bluetooth selective adapter. Circuit can be a circuit of one entity. The terms “activating” and “activate” are different from the terms “initiating” and “initiate”, because “activating” and “activate” implies that the entity subsequently may continue on to perform authorized actions, whereas, “initiating” and “initiate” merely implies that the entity has being powered on, without being given any authentication or permissions for performing further actions. Confined region/space, room, and suite can be adapted to include various indoor, semi-indoor, or even outdoor spaces as well, and thus is not limited to the scope thereof. For example, a secure fence erected around the entire peripheral perimeter can also serve as sufficient boundary for defining an outdoor confined region.
[0076] While the invention has been described in terms of what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention needs not be limited to the disclosed embodiment. On the contrary, it is intended to cover various modifications and similar arrangements included within the spirit and scope of the appended claims which are to be accorded with the broadest interpretation so as to encompass all such modifications and similar structures.
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Short-range and long-range operating methods for hospitality accommodation automation and control using APP, webpage, smartphone, RFID-to-Bluetooth selective adapter, relay controller together with RFID door lock is disclosed, where unlocking RFID door lock requires just pressing a button, various power outlets, lighting levels, HVAC settings, and tv settings can be controlled by smartphone. A gateway device with internet connectivity allows remote unlock or lock of doorlock, sending notifications of door unlock events back to a cloud server, and remotely control electrical or electronic devices under short-range or long-range modes. Detection methods for determining whether any occupant remains inside the room is also included. Current sensor is used for assess electric power consumption rate. Automation enhancements are provided for the hospitality industry to improve overall stay experience of the room unit by offering online services and offline services that can be implemented and activated upon unlocking or locking of smartlock.
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