US2786488A

US2786488A - Pressure device

Info

Publication number: US2786488A
Application number: US407947A
Authority: US
Inventors: Jean Mercier
Original assignee: Individual
Current assignee: Individual
Priority date: 1954-02-03
Filing date: 1954-02-03
Publication date: 1957-03-26
Anticipated expiration: 1974-03-26
Also published as: FR1168103A

Description

March 26, 1957 J. MERCIER PRESSURE DEVICE Filed Feb. 3, 1954 INVENTOR Jean Meficzefl BY I ATTO R N EYS United States Patent In pressure accumulators of the type: including a rigid container having a: pair of ports: atitswrespecti-ve ends with a deformable bladder aflixed. to. oneo-f said ports and separating two fluids such as gas and liquid under.-

pressure, if, as the bladder expands to force liquid from the other of such ports, the walliof the bladder. adjacent. the: free end thereof should cont-act the wall of the container before the portion of the bladder adjacent its affixed end, pockets maybe formed filled with liquid which:

would not be'expelled from the container. Thus, the accumulator would be inefiicient in operation as only a pop tion ofthe liquid in the container would be utilized.

Where the bladder of a pressure accumulator serves.

to close the liquid. outlet portwhen such bladder has ex.- panded in the container to substantially its. maximum amount, if such bladder in its inflated but. undistendjed. condition is of length substantially'equ-al. tothat of the;-

container, the liquid outlet portmay be closed before substantially-all of. the liquid is-expelled. If the bladder is considerably shorter than the container andupon ex:-: pansion of. the bladder, as fluid is forced from the con-- tainer, when the major portion of the bladder wall engages the wall of the container, the free end of the bladder should be considerably spaced. fromthe liquid outlet port,

continued expansion of the bladder will causethe wall.

thereof to rub against the side wall. of the container with resultant breakdown of such bladder; In addition, the lower end of the bladder would have to stretch excessively to reach the liquidport {010101361116 latter, thereby subjecting the bladder to high stress with likelihood of rupture.

It is accordingly among the objects of the invention to provide a pressure accumulator of relatively low cost, which mayreadily-be fabricated and which will function without likelihood of'breakdown or rupture of the-deformable bladder therein and with assurance that substantially all of the liquid will be expelled from the container.

According to the invention, these objects are accomplished by the arrangement and combination of elements hereinafter described and particularly recited in the claims.

In the accompanying drawings in which are shown one or more of various possible embodiments of the several features of the invention,

Fig. 1 is a longitudinal sectional view of a pressure accumulator, and

Figs. 2, 3 and 4 are diagrammatic views illustrating the operation of the bladder.

Referring now to the drawings, the pressure accumulator desirably comprises a container or pressure vessel 11, preferably of strong, rigid material such as steel, cast aluminum or the like, capable of withstanding high pressure and having a gas inlet port 12 and a liquid port 13 therein preferably opposed to each other. The container 11 may be spherical or cylindro-spherical as shown and has a collapsible and expansible bladder 14 therein, desirably of resilient material such as rubber or synthetic plastic of like: physical characteristics,

distended but substantiallyunstretched. condition; is small erthan the cavity of the container ll and has; itslongb tudinal axis aligned with the ports 12 and 13. As shown.-

in ..Fig.. l, thezbladder is: substantiallyconical inv contour along its lengthwith. the. thickness. of the bladderwall gradually decreasing from the larger diameteror mounted end thereof; shown at the; top-to. theopposite end thereof, the. latter enddesirably, beingmubstantiallyfiat as at 16 and. preferably thicker: than. adjacent wall portion of the bladder.

The bladder l i -is. rigidly aflixed inthe container 11 preferably by means of a.fitting.,21,.which; desirably-has.

a. substantially cylindrical s.tem.:.por. tion..2 2- with. a. base disk presenting an outstanding lateral flange- 23, at one end, thereof, which desirably has. annular groove 2.4. in

its upper face 25 in which maybe-positionedthe thickened. ring 26 about the mouth ofthe-bladder 14.. Thus, when the parts are assembled as. shown; in. Fig. l, the bladder may be securely clamped in. place 'bymeans ofa nut. 28: screwed upon the protruding threaded stern of the fitting, an annular shoulder 29- adjacent the :root end: of the stem abutting against the. rim of the: gas inlet port 12 to prevent cutting of the ring. .2'6 of .th-eubladderby excessive tightening of the nut; 1

Although the outlet port 13 of the accumulator could.v

be controlled. in any suitablemanner, in the. embodiment herein shown, .it is preferred to use the general construction shown in PatentNo. 2,469,171 dated -M ay 3,v 194.9, by the. use. of which an outletclosure assembly.

31 alfixed in. said port 13 may be removed without like-- lihood of injury to. the mechanic:..- As shown in Fig. 1,

this. assembly desirably comprises a. housing 32, preferably.

a tubular member which desirably has an external anr. nular shoulder 33- atv the upper end. thereof of'fouter diameter less than that of port 13. A locking member. 34,-

illustratively a ringof. greater outer diameter thanwsaid leakage between the wall of port 13 and the outer wall of tubular member 32 when a nut 37 is screwed on. the. externally. threaded portion .38 of said tubular member 32.

Desirably positioned in said. tubularmember 32. is-af poppet valve comprising a valve head 41 adapted to seat on the beveled mouth 42 of tubular member 32 and having a stem 43 preferably for-med integral therewith. Stem 43 is slidably mounted in bearing opening 44, desirably in a disk 46 mounted in the bore of tubular member 32, said disk having a plurality of openings 48 therethrough to permit the passage of fluid, said valve head being normally retained in open position by means of a coil spring 49 encompassing stem 43 between head 41 and disk 46. As the construction and operation of said outlet closure assembly per se forms no part of this invention it will not be further described.

With the construction above described 0f the bladder and the container, the distance of the partly inflated bladder as shown in Fig. 1, from the inner surface of the container 11, increases progressively from near the fixed end of the bladder toward the free end thereof, and the size, shape and elastic characteristics of the bladder are selected so that in the further expansion of the bladder from its expanded but undistended condition shown, it will progressively engage such inner surface of the container 11 from near the fixed end of the bladder toward its free end.

. l alte'ni: e.d.,lidar.v 26,; 1.9.57

trolling the liquid outlet port 13, is opened and the bladder 14 expands to force liquid from port 13, no liquid pockets will be formed between the bladder and the rigid wall of the container since the bladder is progressively applied against such wall from the end thereof adjacent the point of connection of the bladder thereto to the other end thereof.

As a result, substantially all of the fluid in the container 11 will be forced toward the outlet port 13 for expulsion therefrom.

When the bladder is in inflated but undistended condition the flat bottom 16 will act like a diaphragm to take up pulsation thereby avoiding stress on the side Wall por tion of the bladder.

When the bladder has expanded sufliciently to engage the valve head41, by reason of the large surface area at the flattened end of the bladder engaging said valve head, stresses will not be concentrated and such bottom is desirably reinforced to prevent wear due to its abutment against said valve head.

As the bladder expands to force liquid from the container, both its length and diameter will increase. Inasmuch as the wall thickness progressively decreases from the upper end of the bladder to its lower end, each succeeding portion of the side wall of the bladder will increase in length at a greater rate than the previous portion as indicated in Fig. 2.

Thus, when the bladder is almost fully distended it will assume the position shown in Fig. 3 and the portion :1 of the bladder will engage the lower end of the container as at a".

With additional but still not full distension of the bladder, the portion e thereof will only have to stretch a relatively short distance to move near the lower end of the container (Fig. 4) at which time the central or flat portion of the bladder will be against the valve head 41. Hence, only a slight additional expansion of the bladder is re quired to move the valve head to seated position to close the port 13.

With the construction of the bladder herein described in which the wall thickness progressively decreases, no undue stretching stress is applied to the portion e of the bladder as would occur if the wall thickness was constant or progressively increasing. In such latter cases the portion e of the bladder by reason of the limited elongation of such bladder would engage the'wall of the container at approximately the point z! and hence would be stretched considerably with possible rupture to approach the point e'.

With the construction above described in which the bladder is substantially conical and of decreasing wall thickness from near its affixed end to its free end, en-

trapment of liquid due tothe formation of pockets is substantially precluded with resultant high efliciency in the operation of the accumulator due to the utilization of substantially all of the liquid in the container.

Furthermore, due to the decreasing wall thickness of the bladder, which permits each succeeding portion to increase in length at a greater rate than the previous portion, the portion of the bladder at its lower end will only have to stretch a relatively small amount before the outlet port is sealed thereby avoiding stress on such lower portion which might cause rupture of the bladder and failure of the unit.

As many changes could be made in the above construction, and many apparently widely dilferent embodiments of this invention could be made without departing from the scope of the claims, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and 1 not in a limiting sense.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent of the United States is:

l. A bladder for a pressure accumulator comprising a substantially conical hollow member of resilient deformable material having a port at one end and of greater diameter near said port than at the other end, said bladder having its side wall thickness progressively decreasing from the portion thereof of greater diameter toward said other end.

2. The combination set forth in claim 1 in which the wall thickness of the portion of said bladder adjacent said other end is greater than that of the adjacent wall.

3. A pressure accumulator comprising a substantially cylindrical container having a port at each end, a substantially conical hollow bladder of resilient deformable material in said container having a port at one end afiixed to one of the container ports, said bladder being of greater diameter near said port than at the other end, said bladder having its side wall thickness progressively decreasing from the portion thereof of greater diameter toward said other end, said bladder when in substantially undistended condition having its longitudinal axis aligned with both of the ports in said container and having its side wall spaced from the container wall substantially the major portion of the length of said bladder.

References Cited in the file of this patefi'it UNITED STATES PATENTS 2,397,796 Lippincott Apr. 2, 1946 2,469,171 Mercier et al lay 3, 1949 2,540,676 Johnson et al Feb. 6, 1951 2.604.118 Greer July 22. 1952