Accumulator

3,115,162

Dec. 24, 1963

R, C. POSH ACCUMULATOR

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Dec. 24, 1963

Filed July 16, 1959

R. C. POSH

ACCUMULATOR

3,115,162

Sheets-Sheet 2

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3,115,162

Dec. 24, 1963

R. C. POSH ACCUMULATOR

Filed July 16, 1959 3 Sheets-Sheet 3

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3,115,162

Patented Dec. 24, 1963

United States Patent Office

3,115,162 ACCUMULATOR

Raymond C. Posh, Garden City, Mach., assignor to American Metal Products Company, a corporation or Michigan

Filed July 16,1959, Ser. No. 827,588

Claims. (Cl. 138—30)

This invention relates to accumulators and particularly to an accumulator in which a reserve supply of pres- io surized liquid is maintained.

Difficulty has been experienced in the past when constructing accumulators due to the presence of small apertures through which the fluid passes and a pressurized resilient rubber sleeve which applies pressure to the fluid. 15 In the absence of the fluid, the pressure forces the sleeve toward the apertures and, when sufficient pressure is present and the apertures are of sufficient size, the rubber will pass into and sometimes through the aperture, and small areas will be sheared therefrom, perforating the 20 sleeve. As a result, the apertures in the metal were made as small as possible to reduce the possibility of the rubber of the sleeve being damaged thereby, and to restrict the return flow of the fluid to thereby prevent the pulsation thereof when nonuniformly pressurized by a recipro- 25 rating pump. It has also been found difficult to seal the ends of the sleeve to the outer casing and to the caps applied to the ends thereof. Special sleeves were iieretofore employed having end flanges which were mucii moie expensive than lengths of tubing cut from a continuous 30 length thereof.

It is one object of the invention to so construct the accumulator that flic pressurized rubber sleeve will press against the walls of an element, which close the fluid passageways, to thereby positively prevent the rubber from 3a moving into an aperture and to tnereby permit an unlimited pressure to be applied to the rubber sleeve.

Other objects of the invention are: to provide an accumulator with a central pasageway enclosed by a rubber sleeve having a chamber thereabout containing a gas under 4(1 pressure for applying a pressure on the fluid passing through the central aperture portion; to provide a rubber sleeve having its ends engaging the inner face of the outer casing of an accumulator and sealed therewith upon _ the expansion of the flanges of end caps which me se- ⁰cured in position by welding or by reverse flanging ffie end portions; to form an accumulator from a central element which is cross-shaped in section having end caps witn cross-shaped slots thereon containing serrations on the inner face; to apply a four-fingered element to the ends of a central element which is cross-shaped in section and which, in unbiased position, provides passageways along the disposed cross-shaped element which fire closed when the pressure on the rubber sleeve engages and forces the fingers against the element to prevent the rubber of the sleeve from moving into the passageways; and, in general, to provide an accumulator which is simple in construction, positive in operation and economical to manufacture. , RO

Other objects and features of novelty or the invention will be specifically pointed out or will become apparent when referring, for a better understanding of the invention, to the following description taken in conjunction with the accompanying drawings wherein: .

FIGURE 1 is a broken, sectional view in elevation oi ⁰⁰an accumulator embodying features oi the present invention , r,

FIG. 2 is an enlarged sectional view o± the upper letthand end of the structure illustrated in FIG. 1, as viewed within the oval 2; . .

FIG. 3 is a view of structure, similarly illustrated m FIG. 2, showing another form thereof;

FIG. 4 is a view of structure, similar to that illustrated in FIG. 3, showing still another form of the invention;

FIG. 5 is a view of structure, similar to that illustrated in FIG. 4, showing another form which the invention may assume;

FIG. 6 is a sectional view of the structure illustrated in FIG. 5, taken on the line 6—6 thereof;

FIG. 7 is a perspective view of the core portion of an accumulator embodying a further form of the invention;

FIG. 8 is a view of structure, similar to that illustrated in FIG. 7, with the end portions separable from the central portion;

FIG. 9 is a sectional view of the structure illustrated in FIG. 8, taken along the line 9—9 thereof;

FIG. 10 is an end view of a structure, similar to that illustrated in FIG. 8, showing a further form which the invention may assume;

FIG. 11 is a fragmentary view of a structure, similar to that illustrated in FIG. 8, showing still another form which the invention may assume;

FIG. 12 is a broken sectional view of one end of an accumulator, showing a further form thereof;

FIG. 12A is a sectional view cf the structure illustrated in FIG. 12, taken on the line 12A—12A thereof;

FIG. 13 is a sectional view of the structure illustrated in FIG. 12, taken on the line 13—13 thereof;

FIG. 14 is a view of the structure illustrated in FIG. 12, after pressure has moved the rubber sleeve inwardly, and

FIG. 15 is a sectional view of the structure illustrated in FIG. 14, taken on the line IS—45 thereof.

An accumulator 18 is illustrated in FIG. 1 as comprising an inner cylinder sleeve 19 having apertures therethrough, a resilient rubber sleeve 21 surrounding the sleeve 19 and an outer sleeve 22 which surrounds the rubber sleeve 21. AH of the elements may be cut from lengths of tubing and the inner sleeve 19 may be shaped to be cloverleaf in section with a plurality of apertures extending along the inner portions thereof. After the sleeve 21 is assembled on the sleeve 19 and the sleeve 2.2 is assembled on the sleeve 21, the sleeve 19 is expanded to compress the end of the sleeve 21 against the sleeve 22 and thereby secure it permanently in position. An end cap 23 is then forced within the outwardly offset portion of the inner sleeve 19, the cap and the ends of the sleeves 19 and 22 being secured together by the welding material 24 in a conventional manner.

Another manner of securing the sleeves 19, 21 and 25 in unit sealed relation is illustrated in FIG. 3. In this arrangement a cap 26 is forced inwardly over an annuiar rubber band 27 after the sleeve 19 has been expanded against the end of the sleeve 21 to compress the sleeve against the outer sleeve 22. The annular flange 23 of the cap 26 is sealed by the rubber band 27 to· the inner surface of the sleeve 19, the outer surface of which is sealed by the upper end of the sleeve 21 to the inner surface of the outer sleeve 25. The cap 26 has an outwardly extending flange 29 which limits the inward movement of the cap and over which the inwardly projecting flange 31 of the outer sleeve 25 is rolled and further rolled to extend at 32 inwardly within the cap 26. This firmly anchors the cap to the outer sleeve 22 with the elements in sealed relation to each other.

A further form of securing means is illustrated in FIG. 4 wherein the sleeve 19 is expanded against the sleeve 21 which is compressed against tire end of an cuter sleeve 33 which has an outwardly extending flange 34 at the end. A cap 35 engages the inner surface of the sleeve 19 and is sealed relative thereto by an O-ring 36 which is retained in position when an outwardly extending flange 37 of the cap 35 is rolled downwardly at 38 and inwardly

3,115,162 at 39 to securely lock the cap in position at each end of the device.

In FIGS. 5, 6 and 7, a further form of accumulator is illustrated comprising a central body portion 41 which is cross-shape in section having at the base of the arms 5 42, 43, 44 and 45 passageways 46 which extend at 50 through the end heads 47 into end recesses which slope outwardly to a thin annular edge 48. The rubber sleeve 21 is held against the outwardly curved edge 51 of an outer casing 52 when the cap 53 has its curved annular j&lt;) portion 54 moved into engagement therewith. Thereafter the laterally extending portion is flanged downwardly at 55 and rolled inwardly at 6® to secure the elements together in sealed relation. It will be noted that the sleeve 21 has been forced inwardly to surround the central core, and it will be noted that the rubber may extend into the troughlike slots 46 without damage unless the pressure is sufficient to force a portion into the passageways 5® of the head 47. It is to be understood that all of the caps 23, 26, 35 and 53 at each end of the devices have a threaded bushing 56 therein to permit the fluid to enter the accumulator at one end thereof and to pass therefrom at the opposite end through conduits which are threaded into the bushings.

In FIGS. 8 and 9, a further form of core 57 is illustrated that wherein a central body portion 58 is of uniform cross shape in section and may be an extrusion. As illustrated in FIG. 9, the core has four arms 42, 43, 44 and 45 thereon with separate end heads 59 applied at each end. The heads have cross-shaped apertures 61 30 therein with the inner surfaces provided with shallow corrugations to form passageways 62. The fluid passes through the bushing 56 of one end cap through the passageways 62 along the quadrants between the arms 42, 43, 44 and 45 causing the rubber sleeve to expand 35 against the pressure on the outer side thereof. The fluid then passes through the apertures 62 of the opposite head 59 and out through the bushing 56 on the opposite end of the accumulator.

A further form of the invention is illustrated in FIG. 40 10, that obtained by molding a body portion 58a to a pair of end heads 63. In this arrangement means are provided for producing a plurality of apertures 64 through the body of the head in the area aligned with the quadrants formed by the four arms of the body portion. 45 Pins may be employed as inserts in the molds, or soluble material may be mixed with the resin of the head and dissolved therefrom after the molding operation to provide the passageways. It is to be understood that any of the cores of this invention may be made of a resin, 50 a metal or any other material known to be suitable. When a resin material is employed for the central core having apertures in the end heads, as provided in FIGS. 7, 8 or 10, and the core is assembled with the rubber sleeve 21 and outer sleeve 22, a very inexpensive accumulator is provided which is very durable and substantially indestructible.

A further form of the invention is illustrated in FIG. 11, that wherein portions 65 of an end head 59b extend into the quadrants between the arms 42, 43, 44 and 45 of the cross-shaped member 58b. Passageways 66 between the walls of the member 58b and portions 65 are closed when the thin lip portions 67 are flattened when the rubber sleeve 21 is forced thereagainst. The thin lip portions prevent the rubber of the sleeve 21 from being forced into the apertures and damaged.

A still further form of the invention is illustrated in FIGS. 12 to 15, that wherein the central body portion 5Sc has end bushings 71 provided with a cylindrical end portion 72 which tapers to an annular edge forming a 70 conical recess. The bushings 71 have crossed slots 4® therein forming four sections 73 which are sprung apart to form passageways 74 with the adjacent walls of the arms 42, 43, 44 and 45 of the body portion 53c. The sleeve 21 is sealed to the outer sleeve 33 and to the 75 annular portion 72 of the bushings 71 when caps 75 are pressed into the recess within the annular portion 72 and rolled about the outwardly extending flange 34 of the sleeve 33. The caps have a threaded bushing 56 therein by which fluid is passed through the device from one to the other end thereof. A gas in the chamber 76 between the casing 33 and the rubber sleeve 21 is under a predetermined pressure which forces the sleeve toward the bushings 71 and the body portion 58c to apply the pressure to the fluid passing through the device. When the fluid is bled from the device, the pressure on the sleeve 21 causes it to engage the four sections 73 and force them into engagement with the body portion 58c to mate accurately therewith when closing the 15 passageways therebetween, as illustrated in FIGS. 14 and 15. Irrespective of how much pressure is applied to the rubber sleeve 21, it will not become damaged, since there are no apertures with which the rubber sleeve could contact or move into. It will be noted that the 20 rubber sleeve is actually stretched when moved into the recess between the arms 42, 43, 44 and 45 without any detrimental effects, since there are no apertures into which the rubber could move.

When pressure is again applied through the bushing 56 at one end of the accumulator, the four sections 73 at that end will be forced apart to open the passageways along the walls of the quadrants of the body portion 58c and progressively expand the sleeve 21 as the liquid advances from the one end of the accumulator. Eventually the entire sleeve will be pushed back toward the sleeve 33 away from the sections 73 and the bushing 71 at the opposite end of the accumulator. The sleeve 21 acts on the outer ends of the sections 73 before moving from engagement therewith which, along with the resiliency of the material of the bushing, causes sections 73 to snap outwardly and open the passageways at the leaving end of the accumulator. The material of the bushings 71 is resilient so as to move the sections 73 to their extended position, as illustrated in FIG. 12, aided by the pressure of the sleeve 21 on the outer end of the sections and the leakage of oil beneath the inner ends thereof. To assist this resilient force of the bushing material, a coil spring 77 is employed between the bushing 55 and the base of the sections 73 about an extension of the bushing which locates the spring on the center line of the bushing. After the pressure of the chamber 76 collapses the sleeve 21 upon the withdrawal of the fluid from the accumulator, the sections 73 are forced into the quadrants of the body portion 58c at both ends of the accumulator. Fluid entering the righthand end of the accumulator will overcome the pressure exerted by the adjacent sections 73, the spring 77 and the resiliency of the material to force the sections apart. The sleeve 21 is progressively forced outwardly as the 55 fluid passes to the left until it reaches the sections 73 at the left-hand end of the accumulator, forcing the sleeve 21 outwardly thereof to be spaced from the outer sleeve 33. The fluid will pass between the sections 73 and the walls of the quadrant from the slots 40 at the apices ⁰⁰ of the sections. The pressure exerted thereby will be greater than that on the outer surface, and the sections will be moved outwardly to open the passages, aided by the force of the spring and the resiliency of the material of the sections, and thereby completely open the passageways 74 at the left-hand end of the accumulator.

The fluid will pass through the bushing 56 at one end of the accumulator through passageways 74 along the surface of the central body portion 58c, past the sections 73 into the interior of the sleeve 21. If the accumulator is functioning as a pressure dome closed at the end opposite to that having the bushing 56, the pressure will be maintained in the line connected to the bushing 56 and will dampen surges therein. Whether a bushing 56 is provided at one or both ends of the accumulator, the

3,115,162 pressure is available on the fluid trapped therewithin or passing therethrough.

Referring to FIGS. 1 and 3, a charging valve 81 is illustrated located in a flattened section 82 of the outer sleeve 22. The valve is made from a deformable material, 5 metal, resin or the like, having a cylindrical body portion 83 extending through the wall portion 82. A head 84 on the inner end of the body portion 83 engages a sealing washer 85 and urges it against sealed relation with the inner surface of the wall portion 82. The outside end of 10 the body portion 83 is flanged over at 86 in a manner which will not clamp the washer 85. The loose washer 85 will permit air or other gas to pass through an aperture 87 in the body into the interior of the casing 22 against the sleeve 21. The internal pressure acting on the 15 head 84 wili compress the washer of elastomeric material 85 against the surface of the outer sleeve portion 82 and the body 83 to seal the rubber passageway 87 and the space between the body portion 83 and the casing 22 to prevent the escape of the gas. 20

In any of the arrangements herein illustrated and described, the problem of sealing the inner and outer casings with the rubber sleeves therebetewen has been completely solved by the various modifications herein illustrated. The difficulty of providing apertures of a size 25 to prevent the rubber of the sleeve from becoming damaged when forced thereagainst has likewise been solved. By molding the central core from resins or die cast materials, and by sealing the elements in the manner illustrated, inexpensive but durable accumulators have 30 been provided.