US3113592A - Bladder construction for pressure vessels - Google Patents

Description

J. MERCIER 3,113,592

BLADDER CONSTRUCTION FOR PRESSURE VESSELS Dec. 10, 1963 2 Sheets-Shet 1 Filed Jan. 12, 1960 INVENTOR. JEA N [Wk-Ease WY-M A TTO RNEYF.

Dec. 10, 1963 J. MERCIER 3,113,592

BLADDER CONSTRUCTION FOR PRESSURE VESSELS Filed Jan. 12, 1960 M8 /23 we Mg m 2 Sheets-$heet 2 mmyrok. JEAN MERC/El? BY fia lm United States Patent Office Patented Dec. 10, 1963 3,113,592. BLADDER CONTRUCTION FGR PRESSURE VESSELS .l'ean Mercier, 1185 Park Ave, New York, FLY. Filed den. 12, 196i), Ser. No. 1,931 2 Claims. (Cl. 1383tl) This invention relates to the art of pressure vessels generally known as pressure accumulators, and more particularly to the deformable partition or bladder used in such accumulators.

It is among the objects of the invention to provide a pressure accumulator of relatively low cost, which may readily be fabricated and which will function without likelihood of break-down or rupture ofthe deformable partition or bladder therein.

Another object is to provide a deformable partition or bladder to be used as a separator between two fluids in a pressure accumulator, which bladder has a relatively large open mouth to permit ready extraction therefrom of the core used in the molding thereof and which may be securely, yet releasably, retained in position in a pressure accumulator, without likelihood of rupture or breakdown of the material of the bladder adjacent its relatively large mouth.

According to the invention, the pressure accumulator is of the type having a relatively large opening or mouth and a port opposed to such opening. The accumulator has means adjacent the mouth to mount the periphery of a partition or bladder of resilient deformable material which is positioned in the accumulator to intervene between the opening and the port. The periphery of the partition, which desirably is thickened, has a rigid annular supporting member secured thereto. The mouth of the accumulator is closed by means of a cover plate, the rigid annular supporting member spacing said cover plate from the mounting means for the periphery of the partition. The rigid annular member and the periphery of the partition are conformed so that the elastic material of the bladder will securely adhere thereto, without likelihood of separation between the partition material and the rigid annular member during use of the accumulator.

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

FIG. 1 is a longitudinal sectional view of an accumulator according to one embodiment of the invention,

FIG. 2 is a fragmentary longitudinal sectional view of another embodiment of the invention,

FIG. 3 is a sectional view of the clamping means for the embodiment shown in FIG. 2 after the partition therein is replaced,

FIG. 4 is a fragmentary detail view of another embodiment of the annular supporting member,

FIGS. 5 and 6 are views similar to FIG. 2 of other embodiments of the invention,

FIGS. 7 and 8 are detail sectional views of other embodiments of the invention, and

FIG. 9 is a view illustrating the principle of the invention.

This application is a continuation-in-part of copending application Serial No. 635,154, filed January 22, 1957, now US. Patent 2,959,194 granted November 8, 1960.

Referring now to the drawings, as shown in FIG. 1 the pressure accumulator comprises a container or pressure vessel 11 of strong rigid material such as steel, capable of withstanding high pressures, said container being substantially spherical at one end as at 12 and open at its other end as at 13, said end 13 illustratively being 2 of reduced thickness to define an internal annular shoulder 14.

The end 12 of the container has an axial opening or port 15 in which is mounted a closure assembly (not shown) of any suitable type such as is shown in United States Patent No. 2,469,171, dated May 3, 1949, through which a fluid under pressure, such as oil, may flow into and out of the container 11.

Positioned in the container 11 is a deformable partition 51, illustratively a collapsible and expansible bladder, which desirably is of resilient material such as rubber or synthetic plastic of like physical characteristics.

The bladder has a thickened rim 52 to which an annular supporting member 53 is aflixed, preferably by being bonded thereto or molded therein as illustratively shown. The supporting member 53 is a flat ring of rigid material such as steel, of outer diameter slightly less than that of the shoulder 14, and has its axis aligned with the longitudinal axis of the bladder 51 thereby normally lying in a horizontal plane as shown.

The supporting member or ring 53 is molded with the bladder so that the upper surface of the outer periphery 54 thereof has a relatively thin layer 55 of bladder material thereon, which is also true of the corresponding bottom surface of the ring 53 at the outer periphery thereof as shown at 55 and 57 respectively. The inner periphery of the ring 53, which is embedded in the thickened rim 52 of the bladder, has a rounded surface and the bladder material extends from the thin layer 55 laterally to and beyond such rounded surface 58 in a layer 61 that is of greater thickness than the thin layer 55.

The inner surface 62 of the wall of the bladder extends substantially vertically downward in the illustrative embodiment shown from the inner edge 62 of the thickened layer 61, and the outer surface 63 of the bladder wall tapers inwardly from the outer edge of the lowermost thin layer 56. If desired, the bladder may be conformed in conical shape to provide for progressive engagement of the bladder with the container in the manner shown in Patent Re. No. 23,437, dated December 4, 1951.

Means are provided to close the open end of the container 11 and to retain the bladder 51 and the supporting member 53 in position. To this end, a cover plate 65 is provided, which has a substantially curved central portion 66 with a port 67 therein and an annular flange 68 with a depending lip 69 at its outer periphery 71.

The overall diameter of the cover plate 65 is slightly less than the outer diameter of shoulder 14 as shown in FIG. 1, and the inner diameter of lip 69 is slightly less than the outer diameter of the thicker layer 61.

Thus, when the bladder is positioned in the container ll, the layer 56 beneath the ring 53 will seat on the shoulder 3.4, with the layer 57 on the outer periphery of ring 53 against the wall portion 73 adjacent the shoulder 14.

With the bladder so mounted, it will hang downwardly in the container 11. The cover plate 65, when positioned over the open end 13 of the container, will have the undersurface of lip 69 against the thin layer 55 and the flange 63 against the thickened layer 61.

The cover plate is securely retained in position by means of a retaining ring 74, the side wall 75 of which is internally threaded to coact with complementary threads on the container 11. The top '76 of the retain ing ring extends inwardly over the annular flange 68 so that when the retaining ring '74- is screwed downwardly the cover plate will be clamped against the supporting ring 53, which in turn will be clamped against shoulder 14. By reason of the resilient layers 55, 56, 57 and 61, which will be compressed by such clamping action, a dependable seal will be provided which will prevent leakage of gas or liquid from the end 13 of the container.

With the construction above described, when a valve (not shown) controlling the liquid outlet port 15 is opened, the bladder, which has previously been charged with gas under pressure and compressed by liquid forced into the container 11 through the port 15, will expand to force liquid from the container.

It is well known that when an elastic member is bonded to a plate perpendicular to the direction of the stresses, the maximum fatigue is located at the periphery, and that when elastic material, such as is used in the bladder, is molded or bonded to a rigid member, it tends to unstick first at the periphery, i.e., where the material is bonded to a fiat surface. However, by reason of the rounded periphery 58 of the supporting member, which provides a greater length for extension of the bladder material and hence reduction of stresses at the periphery, the bladder material will adhere securely to such rounded surface so that with repeated expansion and contraction of the bladder in use of the accumulator the bladder and the supporting member will remain securely bonded together.

This is clearly shown in FIG. 9, where when an elastic member X is bonded to a flat plate AE and is subjected to tension Y, the point a will move to a and the point b will move to b. As a-a' is less than b-b (at the periphery), the material at the periphery of the elastic member will have been subjected to more stress or strain than the material between the peripheries of the elastic member and will unstick as at c. This problem is solved by making the length of the material at the periphery of the elastic member longer than its length between the peripheries so that the material at the periphery will not be subjected to greater stress than the material between the peripheries.

The pressure accumulator shown in FIG. 2 is similar in many respects to that shown in FIG. 1 and corresponding parts have the same reference numerals primed.

The container 11' has an outlet port (not shown) identical to that shown in FIG. 1, and a collapsible and expansible bladder 51 is positioned in said container.

The bladder 51' has a thickened rim 52' with an annular supporting member 81 molded therein. The supporting member is desirably curved upwardly adjacent its inner periphery as at 82, and such curved portion has perforations 83 through which the material of the bladder will pass during the molding operation so that the supporting member will be securely retained in position. The bladder material completely fills the concavity 84 of the supporting member and desirably extends slightly beyond a line between the extremities of such concavity. The inner surface 62 of the wall of the bladder extends substantially vertically downwardly from near the inner periphery 85 of the supporting member and the outer surface 63' of said wall tapers inwardly from the outer periphery of the supporting member at its undersurface.

Desirably, the inner periphery 35 of the supporting member has a notch 86 on which is seated the annular lateral flange 87 of reinforcing member $8, illustratively an annulus of resilient sheet material. The side wall 89 of the reinforcing member extends sightly below the supporting member 81 and is reversely bent as at 91.

The bladder 51' with its associated supporting member is positioned in the container 11', with the tapered portion of the bladder adjacent the outer periphery of the supporting member resting on the outwardly curved portion 92 of the mouth of the container 11'.

To close the mouth of the container, a curved cover plate 65 is provided, of diameter substantially equal to that of the supporting member 81, the curvature of plate 65' being such that when the outer periphery of plate 65 rests against the outer periphery of supporting member 81, the inner periphery 85 of the supporting t member 81 will be adjacent the undersurface of the cover plate 65, thereby securely retaining the reinforcing member 88 in position on notch 86.

To retain the cover plate in position, the mouth of the container is rolled over the top of the plate 65' as at 94. Thus, the resilient bladder material in the concavity of the supporting member, as well as the material beneath such member, will be compressed to provide a dependable seal.

In the event that the bladder has to be replaced, it is a relatively simple matter to cut the rolled portion 94 of the container along the line xx. After the-bladder has been replaced, the cover plate may be securely clamped in position by means of a pair of arcuate clamping rings 96 shown in FIG. 3. Each of the clamping rings 96 in cross section is substantially U-shaped, the opposed surface 9 7 of each of the legs having an incline substantially equal to the incline of the top surface of the cover plate 65' and the lower surface of the curved portion 92 of the container.

When the clamping rings are positioned so that the legs thereof straddle the cover plate and the curved portion of the container, and a belt 98, preferably of steel, encompassing the segments is tightened in any suitable manner, the clamping segments will be moved inwardly so that the curved portions of the leg will cam the cover plate downwardly to effect a tight seal.

By reason of the reinforcing member 88, which is of resilient material, as the bladder is compressed and contracts during operation of the equipment, it will abut against the reinforcing member, which will deflect inwardly slightly. However, such reinforcing member will prevent sharp bending of the bladder, that is, it will limit the angle which the bladder Wall may make with respect to the wall of the container, so that fatigue of the bladder will be greatly reduced to increase its life. The curved supporting member 81 also provides a greater length for extension of the bladder material at the region of bonding thereto of the bladder material to provide for secure adherence as described with respect to the embodiment shown in FIG. 1.

The embodiment shown in FIG. 4 is substantially identical to that shown in FIG. 2 except for the construction of the supporting member 81'. Thus, as is clearly shown in FIG. 4, the supporting member has a shape substantially conforming to the shape of the supporting member shown in FIG. 3, but the supporting member of FIG. 4 is corrugated to enhance the gripping action of the bladder material thereto during the molding operation,

The embodiment shown in FIG. 5 is also similar to that shown in FIG. 3, except for the supporting member and the upper end of the accumulator container.

Thus, the accumulator container 106 shown in FIG. 5 has the curved portion 92., but does not have the rolled portion 94 to hold the cover plate in position, but utilizes the clamping rings 96' which are identical to the clamping rings 96 shown in FIG. 3. The supporting member 101 of the embodiment shown in FIG. 5 is an annulus of rigid material such as steel, which is substantially L-shaped in cross section. The supporting member 101 is molded in the thickened rim 102 of bladder 103 so as to be axially aligned with the longitudinal axis of the bladder. The horizontal leg 1% of the supporting member MP1 is rounded at its inner periphery as at 105, which is slightly spaced from the inner surface 1% of the wall of the bladder 103, and such horizontal leg has a plurality of perforations 107 through which the bladder material will pass during the molding operation, securely to retain the supporting member in position in such thickened rim. The vertical'leg 108 of the supporting member is at the outer periphery thereof and is of outer diameter-substantially equal to the outer diameter of the curved portion 92' of the container 1th). The bladder material extends upwardly from the outer periphery of the horizontal leg 104 of the supporting member 101 on its top surface at an angle corresponding to the slope of the inner surface of the cover plate 111, said bladder material on the top surface of the horizontal leg being originally of thickness greater than the spacing between the horizontal leg 104 and the cover plate when the outer periphery of the latter is against the outer periphery of the horizontal leg. Similarly, the bladder material beneath the horizontal leg, which is curved on its outer surface to conform substantially to the curvature of the curved portion 92' of the container 100, also is of thickness slightly greater than the distance between the undersurface of the horizontal leg and the curved portion of the container 100 when the leg 108 is resting against said curved portion.

As the result of such construction, when the cover plate 111 is clamped against the supporting member 101 and the latter clamped against the curved portion 92 of the container, the bladder material on the top and bottom of the supporting member will be compressed to effect a dependable seal.

The embodiment shown in FIG. 6 is similar in many respects to the embodiment shown in FIG. 5. In this embodiment the supporting member 101 is also substantially L-shaped in cross section, but the leg 104' thereon is bent downwardly from the vertical leg 168' thereof to provide space for the bladder material between the leg 104' and the adjacent portion 115 of the cover plate 111' which is substantially horizontal.

The mouth of the accumulator container 1% in the embodiment of FIG. 6 has an annular flange 116 on which the lower end of the vertical leg 198 is positioned, and the side wall of the container rises from said flange and is rolled over the periphery of the cover plate 111 to retain the bladder and cover plate in fixed position.

In both of the embodiments of FIGS. and 6, by reason of the rounded inner periphery of the leg 104, 104 of the supporting members the bladder material will re main securely bonded thereto as previously described.

In the embodiment shown in FIG. 7, the container 121 has an outwardly flaring flange 122 to which is secured as by rivets 123 the periphery of a cover plate 124. The bladder 125 shown in FIG. 7 has its inner surface 126 extending substantially vertically downward from the inner edge 127 of a rigid, annular supporting member 128, which has a flat bottom surface 129 to which the rim of the bladder is bonded. The outer surface 131 of the bladder 125 tapers inwardly from a point spaced from the periphery 132 of the supporting member 128 to provide a greater length of bladder material at the exterior surface of the bladder than inwardly of such exterior surface.

As shown in FIG. 7, the periphery of the supporting member 128 rests on the flange 122 of the container and is clamped thereagainst by the cover plate 124, the portion of the container adjacent its flange being curved as shown to conform to the taper of the bladder.

In the embodiment shown in FIG. 8, the container 133 has an annular flange 134 at its mouth, with an upstanding peripheral rim 135 which is inwardly bent as at 136 to clamp the periphery of a cover plate 137 against a rigid, annular supporting member 138 seated on flange 134, said supporting member 138 desirably having annular seals 139 in its top and bottom surfaces.

The bladder 141 has a thickened rim 142 extending laterally outward and bonded as at 143 to the supporting member. The length of the bladder material at the inner surface 144 of the bladder at its rim is longer than at the outer surface thereof to provide at least at the interior of the bladder, a length of bladder material that will permit extension greater than would be permitted by the length of bladder material outwardly of the interior of the bladder.

It is to be noted that since the longer length of bladder material is subject to less stretching, it would be less permeable, so that escape of gas through the partition, even after long periods of idleness, in the extended position of the partition is greatly minimized.

In all cases in the embodiment shown, it is necessary that there be a length of bladder material at the rim of the partition which is bonded to the supporting member that is longer than the length of bladder material either inwardly or outwardly of the longer length of bladder material as the case may be.

By reason of the constructions above described, a core used in the molding of the bladders may readily be removed therefrom and the reinforcing members at the relatively large mouth of the bladders will permit secure retention of the bladders in position in the container and provide for long life of such bladders.

As many changes could be made in the above constructions and many apparently widely different 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 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 pressure vessel comprising a rigid hollow con tainer having an opening and an opposed port, a partition of resilient deformable material in said container, said partition having a peripheral rim and extending across the container and intervening between said opening and said port, an annular supporting member of rigid material having a flat surface bonded to said partition at the rim thereof, whereby stress is produced against the bonded surface in use of the pressure vessel, the length of the partition material at least one of the wall surfaces of the partition adjacent the rim thereof being longer than the length of the partition material between the opposed wall surfaces of the partition adjacent the rim thereof, whereby the stress of the bonded portion of the rim of the partition against the supporting member at such longer wall surface in use of the pressure vessel will be reduced, mounting means for the rim of the partition at the periphery of said opening and extending substantially laterally outward from said opening to guide the portion of the partition adjacent its rim in use of the pressure vessel so as to maintain the direction of the stress of the partition material intervening between the exterior surfaces of the partition adjacent its rib, exerted against the bonding surface at substantially right angles thereto, a cover plate adapted to extend over said opening and means to retain said cover plate in closed position with respect to said opening, rigid annular supporting member spacing said cover plate from said mounting means.

2. The combination set forth in claim 1 in which the mouth of said container has an outwardly extending flange curved on its top surface at the root end of the flange, said annular supporting member has a flat surface resting on the portion of the flange outwardly of its curved top surface, the curved surface of said flange guiding the portion of the partition adjacent its rim, the inner surface of said partition adjacent its rim being flared to define the longer length of bladder material.

References Cited in the file of this patent UNITED STATES PATENTS 1,885,457 Lord et al. Nov. 1, 1932 2,365,063 Downey Dec. 12, 1944 2,394,401 Overbeke Feb. 5, 1946 2,773,511 Mercier Dec. 11, 1956

Claims (1)

1. A PRESSURE VESSEL COMPRISING A RIGID HOLLOW CONTAINER HAVING AN OPENING AND AN OPPOSED PORT, A PARTITION OF RESILIENT DEFORMABLE MATERIAL IN SAID CONTAINER, SAID PARTITION HAVING A PERIPHERAL RIM AND EXTENDING ACROSS THE CONTAINER AND INTERVENING BETWEEN SAID OPENING AND SAID PORT, AN ANNULAR SUPPORTING MEMBER OF RIGID MATERIAL HAVING A FLAT SURFACE BONDED TO SAID PARTITION AT THE RIM THEREOF, WHEREBY STRESS IS PRODUCED AGAINST THE BONDED SURFACE IN USE OF THE PRESSURE VESSEL, THE LENGTH OF THE PARTITION MATERIAL AT LEAST ONE OF THE WALL SURFACES OF THE PARTITION ADJACENT THE RIM THEREOF BEING LONGER THAN THE LENGTH OF THE PARTITION MATERIAL BETWEEN THE OPPOSED WALL SURFACES OF THE PARTITION ADJACENT THE RIM THEREOF, WHEREBY THE STRESS OF THE BONDED PORTION OF THE RIM OF THE PARTITION AGAINST THE SUPPORTING MEMBER AT SUCH LONGER WALL SURFACE IN USE OF THE PRESSURE VESSEL WILL BE REDUCED, MOUNTING MEANS FOR THE RIM OF THE PARTITION AT THE PERIPHERY OF SAID OPENING AND EXTENDING SUBSTANTIALLY LATERALLY OUTWARD FROM SAID OPENING TO GUIDE THE PORTION OF THE PARTITION ADJACENT ITS RIM IN USE OF THE PRESSURE VESSEL SO AS TO MAINTAIN THE DIRECTION OF THE STRESS OF THE PARTITION MATERIAL INTERVENING BETWEEN THE EXTERIOR SURFACES OF THE PARTITION ADJACENT ITS RIB, EXERTED AGAINST THE BONDING SURFACE AT SUBSTANTIALLY RIGHT ANGLES THERETO, A COVER PLATE ADAPTED TO EXTEND OVER SAID OPENING AND MEANS TO RETAIN SAID COVER PLATE IN CLOSED POSITION WITH RESPECT TO SAID OPENING, RIGID ANNULAR SUPPORTING MEMBER SPACING SAID COVER PLATE FROM SAID MOUNTING MEANS.

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