Accumulator

Jan. 25, 1344.

2,339,875

M. J. PHILLIPS

ACCUMULATOR

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Patented Jan. 25,1944

2,339,876

UNITED STATES PATENT OFFICE

2,339.876

ACCUMULATOR

Michael J. Phillips, Cleveland, Ohio, assignor to Pesco Products Co., a corporation of Ohio

Application January 13,1941, Serial No. 374,189

Claims. (CI. 138—30)

This invention relates to pressure containers built of a plurality of hollow sections and particularly to the type wherein a flexible diaphragm is held about the periphery thereof between the joining edges of the sections for dividing the container housing into two chambers one of which is adapted to receive air under pressure and the other fluid such as oil under pressure.

It is an object of this invention to provide an improved form of joining means between the two sections of a plural section housing and a diaphragm held therebetween, whereby to effect increased operating efficiency, long life and ready assembly and disassembly.

It is an object to provide an arrangement of the above type which is effective to prevent the respective mediums contained on the opposite sides of the diaphragm from leaking therearound either into contact with each other or from making an exit to the surrounding atmosphere.

Other and more specific objects, advantages and uses of my invention will become apparent from a reading of the following specification taken together with the accompanying drawing which forms a part thereof and wherein:

Fig. 1 shows the general arrangement of a pressure accumulator embodying a preferred form of my invention; and

Fig. 2 is an axial broken-away cross-section taken substantially on the line 2—2 of Fig. 1 showing the details of a preferred embodiment of my invention.

Referring in greater detail to the figure's of the drawing, an accumulator embodying a preferred form of my invention is indicated generally at 10 and comprises a first hollow hemispherical housing section 11 and a second such section 12 fastened together and confining therebetween a diaphragm 13 functioning to divide the interior into a first chamber 14 and a second chamber i5. The upper chamber 14 is adapted to contain fluid such as air under pressure introduced through valve assembly 16, while the lower chamber IS is adapted to receive an accumulation of fluid such as oil under pressure, this fluid being introduced through inlet port 17.

The usual function of chamber 15 is to hold a reserve volume of fluid under pressures of the order of a thousand (1000) pounds per square inch, which fluid must be immediately available for use in operating various fluid pressure responsive instrumentalities such for example as the many devices on an aircraft.

It will be readily appreciated that the severe conditions under which this assembly must operate require specially constructed and efficient means connecting the housing sections together and holding the periphery of the diaphragm therebetween. Of very great importance in this 5 connection is the provision of an arrangement for effectively and efficiently holding the periphery of the diaphragm including both avoiding destructive applications of force thereto and effecting the necessary seal against the passage 10 thereby of the confined fluids. For example, it has been found that all arrangements of means for tightly clamping the periphery of the diaphragm are completely ineffective due to the destructive effects of the distortion produced in the 15 flexible material.

Generally speaking, I have found that the best results are obtained by forming the opposed peripheral portion of the accumulator sections to define, a mouth-like cavity having a closely 20 spaced pair of lips providing for the passage therebetween of the diaphragm which in turn is formed with an enlarged peripheral rim received within the mouth-like cavity and provided with fluid responsive sealing means engaging the in25 terior walls of the mouth-like cavity to prevent the passage thereby of the confined fluids. The outer wall portion opposite the back of said mouth-like cavity is preferably threaded for complementary cooperation with an overlapping 30 threaded wall portion of the adjacent housing section for the purpose of holding the sections together.

In the preferred embodiment disclosed the upper housing section 11 is formed with an enlarged ₃₅ terminal portion 20 having a first tubular terminal wall 21 extending therefrom and an upper “lip” defining wall 22 of shorter length than said first wall, and spaced radially inwardly therefrom to define with said first wall the upper and ₄₀ back portion of a mouth-like cavity for the reception of a diaphragm as will appear. Wall 21 is formed externally thereof with threads 23 for cooperation with complementary threads 24 formed on the inner periphery of over-lapping 45 wall 25 extending from enlarged terminal portion 26 of lower housing section 12. Also extending from terminal portion 26 is a lower “lip” defining wall portion 27 in turn defining with the opposite surface of wall 21 the lower portion of 50 said mouth-like cavity, the upper extremity of wall 27 being spaced from the lower extremity of wall 22 a distance of the order of the thickness of the main body portion of the diaphragm to be received therebetween.

Diaphragm 13 is positioned with the outer * 2,339, portion thereof between upper and lower Up 22 and 27, with these lips inIntimate contact therewith but only slightly compressing the diaphragm therebetween, the extremities of these lips being rounded as shown to give the most desirable 5 bearing surfaces against which the diaphragm may operate as the position of the same is shifted with varying pressures. The diaphragm is formed at the periphery thereof with an enlarged generally cross-section rim portion 30, 10 positioned with the mouth-like cavity. This enlarged rim portion is preferably of a general rectangular cross-section, the major axis of the rectangle extending generally parallel to the normal, vertical or major axis x of the accumu- 15 lator and of the diaphragm, the periphery of the latter joining the rectangular cross-section at a position intermediate the extremities thereof thus giving the maximum reenforcing and retaining function to the rim portion. One side 20 of the rim, preferably that adjacent the upper chamber 14, usually containing air under pressure, is formed with a pair of axially extending spaced flexible lips 3( arranged to be initially spread into engagement with the adjacent suf- 25 faces of walls 21 and 22 by means of a spreading flange 20a extending from enlarged terminal portion 20, these lips being responsive to fluid pressure leaking into contact therewith from chamber 14 to force the same tightly against the ad- 30 jacent surfaces of walls 2( and 22. The opposite side of rim. 30 is formed with a reduced cross-section terminal flange 32 and is arranged to be embraced by a pair of spaced flexible lips 33 of an auxiliary sealing ring 34 .located in the 35 lower portion of the mouth-like cavity, these Ups being initially spread into contact with the adjacent surfaces of walls 21 and 27 by the reduced section flange 32 but being additionally responsive to such fluid pressure as leaks into contact 40 therewith for forcing the same'into tight engagement with the adjacent surfaces of said walls.

To still further improve the sealed engager ment between the peripheral rim portion of the 45 diaphragm and the wall 2i, I have formed a plurality of vertically spaced generally triangular ring-like protuberances 35 on the rim, which protuberances are received in complementarily formed recesses in the adjacent surface of wall 50

21.

I have found that any air which tends to leak around depending lip 22 and into a position between flexible lips 31 is effective to so tightly press the same against the adjacent surfaces of walls 55 2( and 22 that no leakage of air about the diaphragm 13 normally results. Furthermore, with the provision of the above described auxiliary ring seal 34 any oil that succeeds in leaking around lower lip 27 and into a position between ₆o the lips of auxiliary sealing lips 33 of auxiliary sealing ring 34 as well as any air that may succeed in passing around lips 31 and protuberances 35 will be effective to so completely force lips 33 into engagement with the adjacent surfaces of 65 walls 2 ( and 27 that no resultant leakage occurs. This arrangement of seal construction and holding means for the periphery of the diaphragm is so very effective that I have been unable to detect any leakage of air from chamber (4 into 70 contact with the oil in chamber (5 or the leakage of either air or oil out of the accumulator past threads 23 and 24, nor have I been able to detect any appreciable wear adjacent the periphery of the diaphragm by virtue of this ar rangement of holding means even after a long period of usage.

For supporting the accumulator assembly I·, as for example on an aircraft with which the same is to be associated, I have found it desirable to position a flat washer-like ring 3t between the end of wall 25 and a complementary shoulder on terminal portion 20 additionally securing the same in place by means of pins 37. The accumulator (0 will be associated with the other conventional equipment forming no part of the present invention and which will Include the necessary fluid supply and pumping means for maintaining the same charged connected thereto through inlet ports (7.

While I have disclosed my Invention in connection with a specific embodiment thereof this has been by way of illustration rather· than by way of limitation and it is my intention that the invention be construed in terms of the appended claims which should be given a scope as broad as the prior art will permit.