US2764997A - Accumulators - Google Patents

Description

Oct. 2, 1956 T. J. M CUISTION ACCUMULATORS Filed Oct. 22, 1953 mwzzvrox. 76mm J/Vc 60/5770 BY I United States Patent ACCUMULATORS Tommy J. McCuistion, Euclid, Ohio Application October 22, 1953, Serial No. 387,652

2 Claims. (Cl. 138-31) The present invention relates to the art of accumulators of the piston type.

As stated in my co-pending applications, it is well known that in the use of a piston type of accumulator in connection with hydraulic equipment, as for instance in an airplane, the piercing of the wall of the storage chamber for the liquid might cause suflicient internal displacement and instantaneous increase in internal pressure to produce an explosion-like bursting of the accumulator walls and a consequent scattering of the metal particles. This of course may prove very serious and hence this type of accumulator is a real hazard under such conditions. This old type of accumulator is objectionable also because of the transmission of vibrations or surging due to the operation of the pump connected to the same. These are the conditions which my present improved form of device is intended to correct.

Accordingly, one object of my present invention is to devise a piston type of accumulator with means for quickly absorbing the increased internal pressure due to the displacement of a bullet or other object piercing the wall and entering the liquid-storage chamber of the accumulator.

Another object is to devise an accumulator of this type that is capable of absorbing minor fluctuations or surges of internal pressure that might be due to impulses of the pump or other hydraulic mechanism associated therewith.

Another object is to devise an accumulator of this type in which the piston itself is provided with an auxiliary chamber within which there is located a flexible diaphragm and which is provided with means of communication through the walls of the auxiliary chamber so that the diaphragm may respond to the force of the pressure.

Other objects will appear from the following description and claims when considered together with the accompanying drawing.

Fig. 1 is a longitudinal sectional view of one form of my invention embodied in a piston type of accumulator;

Fig. 2 is a longitudinal sectional view of another form of my invention embodied in a piston type of accumulator; and

Fig. 3 is a longitudinal sectional view of still another form of my invention embodied in a piston type of accumulator.

Referring now to Fig. 1 of the present drawing in detail, the metal cylinder 1 has the piston 2 which divides the interior space into an oil-containing chamber 3 and a chamber for a gaseous body, as indicated by reference numeral 4. The end head 5 for the chamber 3 has a nozzle form of connection 6 and the passage therethrough is divided into a plurality of annularly spaced inwardly diverging passages 7 opening into the oil-containing chamber 3. With this arrangement of passages, the force of pressure within the oil-containing chamber 3 will be diverted angularly outwardly and thus the screw-thread connection 6a will be relieved of the force of any such excessive pressure that might otherwise disrupt such 2,764,997 Patented Oct. 2, 1956 screw-thread connection to the nozzle 6. This nozzle has the screw-threaded plug closure 6'.

The end head 8 for the chamber 4 may be provided with any suitable form of valve so as to permit supply of the gaseous body thereinto and to prevent escape of the same therefrom except when desired. In the present case I have indicated the head 8 as having an annular shoulder at the inner end of the nozzle 10 which in turn is adapted to receive the apertured screw-threaded plug 11 for engagement at its inner end with the closure disk 12.

Disk 12 serves as an abutment for the coil spring 13 which is adapted to hold the apertured disk 14 against shoulder 9. With these parts in the position indicated in Fig. 1, there can be no escape of the gaseous body from the chamber 4; but by forcing inwardly disk 12, to which access may be had through the plug 11, the gaseous pressure may be relieved through the apertured disk 14 and around the open disk 12. The gaseous body may be supplied to chamber 4 through nozzle 11 and its valve, just described, as the disk 12 will yield to such pressure and will be automatically closed by its spring 13 upon discontinuance of such gaseous pressure inwardly through the nozzle 11.

The piston 2 may have suitable sealing means, as for instance multiple 0 rings of elastic composition, arranged within grooves in the perimeter of the piston and with relief ports to prevent pressure lock between these rings, as illustrated; and there may be the same provision in each of the other two forms of device illustrated in Figs. 2 and 3 hereof.

In Fig. 1 of the present drawing the piston may be recognized as having an integrally formed transverse wall 15 which is located substantially midway of the length of the piston; and at the side of the piston towards the oilcontaining chamber 3 there is a screw-threaded flanged wall member 16 with a central aperture 16a of less diameter than the central full portion 5a between the inner ends of the diverging passages 7 in the end head 5 for a purpose to be explained. The edge of the wall 16 about the aperture 16a adjacent the diaphragm may be rounded so as to avoid any danger of cutting the diaphragm 17 and, for the same reason, the disk 16 and the wall 15 may be rounded in the region thereof that is adjacent the diaphragm 17. The wall member 16 is adapted to engage the outer marginal portion of the flexible diaphragm 17 so as to hold the same in proper assembly within the annular groove provided in the wall 15. The edge por- 'tion of the diaphragm may be of enlarged cross section and may have snug engagement within its groove; and the central portion of the wall, adjacent the diaphragm, may be cupped out so as to provide suitable clearance which may be recognized as an auxiliary chamber between the main portion of the diaphragm and the wall 15 and thereby permit action of the diaphragm in response to any surge of pressure within the oil-containing chamber 3.

The wall 15 is provided with a central aperture therethrough to accommodate a tubular valve body 18 which has a closed mushroom-like end 18d normally held towards the diaphragm by the coil spring 18b which surrounds the valve body 18 and has engagement at its two ends against the end 18d and the shoulder surrounding the aperture in the wall 15. The hollow valve body 18 is provided with radially disposed apertures 18c therethrough which are normally in open communication with the space between the diaphragm and the wall 15; and the mushroom-like end 18d is adapted to seat within the recess in the adjacent side of the wall 15 when there is exerted sufficient pressure upon the diaphragm 17 from the liquid-containing chamber 3, at which time the ports 18c will be closed. The other end of the valve body 18 may have an vannular flange 18a peened over so as to maintain the same in assembly; and this side of the piston is cupped out sufiiciently so that the valve 18 will not protrude therebeyond.

Thus the space between the diaphragm 17 and the wall 15. may be recognized as an auxiliary chamber for the gaseous body since it is normally in communication with the chamber 4 in Fig. I; and, in the event of excessiye pressure within the oil-storage chamber 3, the diaphragm may first respond by movement towards the right, as viewed in Fig. l of the drawing, so as to force the gaseous body from this auxiliary chamber through the restricted passage in the valve 18 and into the chamber 4 until the valve 18 is closed thereby. Then, upon continuation of such excessive pressure within the oil-storage chamber 3, the entire piston may respond thereto by moving bodily towards the right, as viewed in Fig. I of the drawing, and thereby effecting a corresponding compression of the gaseous body within the chamber 4. Upon relief of such excessive pressure within the chamber 3, the parts will be returned automatically to their positions as indicated in Fig. 1, which is to be recognized as normal.

In the form of device illustrated in Fig. 2, the oilstorage chamber 3* may have a conventional supply connection 6' in the screw-threaded end head 5, a closure plug 65 in the screw-threaded opening 6a; and the chamber 4' for the gaseous body may have the same form of valve in the end head thereof as in Fig. 1 or any other conventional form of such valve, and there may be the same provisions for the corresponding end heads of the chambers in the form of device illustrated in Fig. 3 thereof.

Referring further to the form of accumulator shown in Fig. 2 of the drawing, the piston has a transverse wall 21 substantially midway of the length thereof and this wall 21 has an annular groove to receive and snugly hold the enlarged marginal portion of the flexible diaphragm 22 upon the side of the piston that faces the liquid-storage chamber 3'. The diaphragm is held in such asembly by means of the screw-threaded flanged disk 23. The disk 23 and wall 21 are rounded in the region of the diaphragm 22 for the same reason as explained in connection with the form of device shown in Fig. 1 of the present drawing. The disk 23 is provided with a central aperture 23a of outwardly converging or tapering form that is adapted to receive inseating engagement the correspondingly formed valve- 24 which is mounted upon the central portion of the diaphragm 22. The valve member 24 has a centrally disposed shank whose free end is swaged over so as to hold in engagement against the opposite side of the diaphragm the valve disk member 25 which may have seating engagement with the shoulder about the centrally disposed port 21a in the wall 21 of the piston. The space between the diaphragm 22 and the wall 21 may beregarded as an auxiliary chamber. The coil spring 26 normally forces the valve 24 to closed position upon its seat in the opening 23a; and, at the same time, the valve 25 is held off of its seat. In this condition it is assumed that there is no excess pressure within the chamber 3'. In the event, however, of such excess pressure within the oilcontaining chamber, the valve 24 may first be forced open so as to permit exertion of pressure by the diaphragm upon the gaseous body within the auxiliary chamber within the piston and within the main chamber 4' through the comparatively restricted aperture 21a; and, upon continuance of such excess pressure, the valve 25 may be forced to closed position and the piston may then be moved bodily towards the right, as viewed in Fig. 2 of the present drawing, so as to exert still further compression of the gaseous body within the chamber 4'. Upon relief of such excess pressure, the parts will return automatically to the position indicated in Fig. 2 which may be recognized as normal.

In the form of accumulator illustrated in Fig. 3 of the accompanying drawing, the piston 30 is provided with a transversely extending wall 31 substantially midway of the length thereof and this wall is provided with a central opening 311: therethrough that is covered by a body 32 of porous material as for instance porous metal seated upon the side of the wall 31 that is adjacent the oil-storage chamber 3". The flexible diaphragm 33 has an enlarged outer edge snugly engaged within a groove in the wall 31 and is held in such assembly by the slip ring 34 which engages the same and which is held in such engagement by the disk of porous metal 35 or other suitable porous material. The ring 34 is rounded in the region of the diaphragm 33 in order to preclude any damage thereto. As indicated in Fig. 3 of the present drawing, there is substantial space between the diaphragm 33 and the porous disks 32 and 35 so as to provide what might be recognized as an auxiliary chamber within the piston 30. Upon initial exertion of excess pressure within the oil-storage chamber 3", such pressure may be transmitted through the porous disk 35 and exerted upon the diaphragm 33 which will respond thereto by transmitting such pressure to the auxiliary chamber between the same and the porous disk 32. Continuation of such excess pressure may cause the same to be transmitted through the porous disk 32 into the chamber 4". Thus there may first be response to such excess pressure by and entirely within the relatively confined auxiliary chamber upon the opposite sides of the diaphragm 33 and then, if need be, within the chamber 4 in the manner explained. The condition of the diaphragm 33, as indicated in Fig. 3 of the accompanying drawing, is to be recognized as normal.

This invention in each of the several forms herein illustrated, includes. a unitary assembly of piston and diaphragm that is responsive bodily to the excess pressure Within the liquid-containing chamber; and there is also provided in each instance between the diaphragm and the piston an auxiliary chamber that is responsive to the initial exertion of such excess pressure, together with pressure-responsive means. for permitting transmission of such excess pressure to the chamber for the gaseous body. Each of these several forms of device is of simple and compact construction and is capable of operation in an eflicient and dependable manner. in the prevention of the damage that might occur in the event of excess pressure within the liquid-storage chamber, as above explained.

It is to be understood that the present forms of disclosure are merely for the purpose of illustration and that there might be still further modifications without departing from the spirit of my invention as herein set forth and claimed.

What I claim is:

1. An accumulator comprising a cylinder, a piston reciprocatabl'e' longitudinally within said cylinder and dividing the interior thereof into separate chambers for a liquid and a gaseous body, respectively, said chambers having inlet and outlet openings through the wall of said cylinder for passing the liquid and gaseous body, respectively, said piston having transversely disposed fluid-transmitting end walls spaced from each other to a substantial extent lengthwise of the cylinder, at flexible diaphragm extending transversely and substantially midway between the end walls of said piston and having its marginal portion secured between and in spaced relation to said end walls so as to be responsive to pressures within said chambers, and valve means provided upon said diaphragm for controlling the flow of the liquid and the gaseous body through the end walls of said piston.

2. An accumulator comprising a cylinder, a piston reciprocatable longitudinally within said cylinder and dividing the interior thereof into separate chambers for a liquid and a gaseous: body, respectively, said chambers having inlet and outlet openings through the wall of said cylinder for passing the liquid and gaseous body, respectively, said piston having transversely disposed fluid-transmitting end walls spaced from each other to a substantial extent lengthwise of the cylinder, a flexible diaphragm extending transversely and substantially midway between the end walls of said piston and having its marginal portion secured between and in spaced relation to said end walls so as to be responsive to pressures within said chambers, and a one-way valve provided upon said diaphragm for each of said transversely disposed walls for controlling flow of the liquid and gaseous body, respectively, therethrough, whereby each of said valves is adapted to be closed by pressure upon the opposite side of said diaphragm.

References Cited in the file of this patent UNITED STATES PATENTS Kremiller Mar. 11, 1947 Snyder Apr. 15, 1952 Snyder Dec. 22, 1953 McCuistion Nov. 23, 1954

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