Abstract: A diaphragm comprising a resin layer for gas shielding, a rubber layer adapted to be adjacent to a gas chamber of an accumulator, and a rubber layer adapted to be adjacent to an oil chamber of an accumulator, the rubber layers formed on opposite sides of the resin layer. The rubber layer adapted to be adjacent to the gas chamber is formed of a mixture of butyl rubber and ethylene-propylene-diene terpolymer. Also provided is an accumulator including the above diaphragm.

Abstract: An I-type counterflow absorber for directly connecting with a piping system to absorb the impact force and noise resulting from water hammering in the piping system. It includes an outer tube, an inner tube, a valve seat, a valve and an annular piston board. The outer tube includes a front tube and a rear tube. The valve seat is located between the front tube and the rear tube and has a funnel groove and a passage formed therein. The inner tube is located in the rear tube and has one end engaging with one side of the funnel groove. The valve includes a valve engageable with another side of the funnel groove. The piston board is located between the inner tube and the rear tube for separating the space between the inner tube and outer tube in a buffer zone and an air chamber filled with air.

Abstract: Accumulators/compensators for pressurized fluent material systems are provided, in which a continuous substantially non-permeable, flexible membrane (like a bellows) surrounds or is surrounded by a non-gaseous support medium, all within a surrounding housing. Various combinations of support media, which may include internal gas-filled cavities, are described and illustrated.

Abstract: A vehicle brake control device includes a wheel cylinder mounted on a wheel of a vehicle, a master cylinder which generates a brake fluid pressure according to the amount of operation of the brake pedal and supplies the brake fluid pressure to the wheel cylinder, a pump which draws brake fluid out of a reservoir for generating a brake fluid pressure, and an accumulator which stores the brake fluid pressure generated by the pump. A change-over valve is disposed between the master cylinder and the wheel cylinder to disconnect the wheel cylinder from the master cylinder during its non-operational condition and to connect the wheel cylinder to the master cylinder during its operational condition A fluid conduit connects the accumulator to the wheel cylinder during the non-operational condition of the change-over valve, and a regulator is disposed on the fluid conduit to regulate the fluid pressure in the accumulator according to the amount of brake pedal operation.

Abstract: A shell is constructed by an outer shell and an end plate. The end plate has a port into a liquid champer and a gas champer. A bladder divides an internal space of the shell into a liquid champer and a gas champer. A gas is introduced into the gas chamber without the provision of a gas inlet hole in the outer shell located on the side of the gas champer. For example, an accumulator is assembled by combining the outer shell, the end plate and bladder under atmosphere of a high pressure gas.

Abstract: A surge absorber assembly comprises a metal case provided with a recess, a metal diaphragm attached to the perimeter of the case to form a back pressure chamber in the recess being charged with high-pressure gas, and a metal plate attached so as to hold the diaphragm against the perimeter of the case to form a damper chamber facing the diaphragm, the case, the diaphragm, and the plate being joined by a weld formed by fusing the respective perimeters thereof, and a groove being formed in at least one of the case and the plate alongside the weld.

Abstract: A pulsation noise damper has an axially symmetrical housing (4) forming a chamber (3) in which pressurized hydraulic fluid flowing in an elevator system hydraulic line can expand. For the collection of contaminates in the hydraulic fluid a filter (6) is arranged at one of a pair of input/output openings (5) formed the housing (4). A pair of compression elements (7), each in the shape of an elastic bellows, are positioned in end openings (4a) formed in the housing (4) and the stiffness of each is selectively adjusted by a movable pressure plate (8) coupled to a fastening element (9). In this way the pulsation noise damper can be adapted to various levels of pulsation energy. The compression elements (7) are retained by end caps (1) attached to the housing by fasteners (2) and the fastening elements (9) extend through the end caps and are fixed by nuts (10).

Abstract: A high-pressure accumulator is provided which protects a diaphragm from abnormal displacement. A high-pressure vessel 101 is provided with support portions 107, 108 having contact portions facing the vicinity of the central portion of a diaphragm 106. The support portions are annular and have the same center as that of the high-pressure chamber. The support portions may also have a plurality of holes. The support portions have curved surfaces 107a, 108a which make contact with the diaphragm uniformly when the diaphragm is displaced. In addition, the support portions may be either integrated with or separated from a case 101. A seal portion is disposed on the cylindrical outer wall 109a of a plate 109 disposed in a position on the opposite side of the diaphragm 106 from the case 101.

Abstract: An improved structure of a pressure regulator including a body and an adjusting device. The adjusting device includes a retractable bent in shape from a metal material and provided on an upper side of the body. The secondary pressure in the interior of an enclosed space defined between the retractable tube and upper and lower plates is utilized to act in a stable and uniform manner on the upper plate to thereby change the length of the retractable tube and bring a valve plug to elevate so as to control high pressure gas flowing from a primary pressure chamber to a secondary pressure chamber. By means of the elasticity of the retractable tube that coordinates with the pressure of the gas, the output of secondary pressure can be stable and precise without being affected by the pressure different caused by change in the internal pressure of the container (steel cylinder), thus having the advantages of extended service life and enhanced safety.

Abstract: A pressure relief adapter includes a body and a slideable sleeve positioned in a passageway thereof and cooperating therewith and with O-rings to define a sealed chamber containing ambient air or other gas. The slideable sleeve has an enlarged head at one end. A compression spring in the chamber urges the sleeve toward the end having the enlarged head. Upon introduction of hydraulic fluid under pressure into the passageway and sleeve, the hydraulic fluid acting on the enlarged head urges the sleeve in a direction compressing the spring and reducing the size of the chamber thereby relieving pressure in the fluid flow system in which the adapter is positioned.

Abstract: An energy storage device particularly suitable for use in hybrid fluid power systems and fluid systems utilizing accumulators. A piston accumulator has a primary face on one end of the piston and a series of secondary faces on the opposite end of the piston. Each face has an associated chamber, and one or more of the chambers of the secondary faces may be selectively connected to a system pressure line. Since the pressure of the system pressure line depends on (and varies with) the number of chambers connected thereto, the potential energy of the chamber of the primary face may be delivered to the system pressure line at a variety of output pressures. Similarly, the chamber of the primary face may be recharged with energy at a variety of input pressures.

Abstract: There is provided a pressure accumulator system comprising a plurality of small-sized gas bombs connected. This dispenses with any large-sized gas bomb that is hard to handle. The pressure accumulator system comprises a plurality of gas bombs each having an ejection port sealed by a membrane member, a membrane-breaking mechanism mounted in the ejection port of each of the gas bombs and operated in accordance with a given electrical signal to force the membrane member of the gas bomb to break, a sequencer for sending an electrical control signal to the membrane-breaking mechanisms to activate them, and a pressure sensor mounted in a conduit communicating the gas bombs and an actuator for producing an output signal to the sequencer. The sequencer is operated according to the output signals from the pressure sensor and, when the pressure inside any one of the gas bombs becomes lower than a present pressure.

Abstract: The preferred embodiment of the invention is a fluid pressure alleviating pneumatic or hydraulic system component. The invention is comprised of a diaphragm, carrier and a release mechanism. The diaphragm is attached to the carrier. The release mechanism bears against the diaphragm and positions it such that fluid pressure on the surface of the diaphragm produces only or primarily shear force at the connection between the carrier and the diaphragm. The connection and parts have sufficient strength so that the fluid pressure can not shear the diaphragm from the carrier. When the fluid pressure becomes excessive the release mechanism, under force, retreats and allows the pressure of the fluid medium to translate the diaphragm into a position relative to the carrier that will invoke peel force between the carrier and the diaphragm.

Abstract: The invention relates to a valve system for a space (1) which is under vacuum in relation to its surroundings (3), which valve system comprises a valve unit (7) which is intended to be arranged in association with a wall (2) which delimits the said space and has a wall opening (4) through the said wall, which valve unit comprises a valve (8) which is normally shut and closes the said wall opening but is arranged to be opened and allow air from the surroundings into the said space if the vacuum, i.e.

Abstract: An attenuator for a hydraulic control unit of a vehicular braking system includes a hollow cylinder mounted in a bore of a housing. An end cap closes an outer end of the cylinder and does not extend beyond an outer wall of the housing. The cylinder and end cap define an interior chamber having an inner diameter tapered toward the end cap. An orifice is formed in the cylinder to permit fluid to exit the tapered interior chamber. An elastic core piece is fitted into the tapered interior chamber and substantially fills the volume of the chamber. An annular clearance is provided between the core piece and the cylinder. An inlet passage formed in the housing delivers fluid to the chamber. Fluid passes about the core piece to the orifice to reach the an outlet passage formed in the housing. Clearance between the core piece and the cylinder provides a streamlined path for fluid traveling from the inlet passage to the outlet passage, thereby decreasing fluid turbulence and aeration found in prior art attenuators.

Abstract: A hydraulic pressure booster is disclosed which, when used in conjunction with a control system for a subsurface safety valve, allows the use of lower pressure ratings on the wellhead equipment, yet at the same time provides sufficient hydraulic pressure to actuate a subsurface safety valve at depths that could exceed 4,000 feet. A preferred embodiment compensates for any fluid loss through the seals to ensure effective operation. The hydraulic pressure booster comprises an amplifier to receive fluid pressure from a fluid pressure source and magnify the pressure. A conduit system facilitates connection of the pressure source to the amplifier and the magnified pressure from the amplifier to the subsurface safety valve. The system is simple and self-regulating and can be alternatively installed as an integral portion of the subsurface safety valve or immediately adjacent the subsurface safety valve or immediately below the wellhead.

Abstract: A hydraulic damper is disclosed for reducing undesirable pressure differentials in a hydraulic system. The damper comprises a body assembly, including first and second inlet ports for connecting the damper to a hydraulic system. A pair of lap assemblies are provided for equalizing pressure differentials between the inlet ports. Each lap assembly is in fluid communication with each of said inlet ports. A metered passageway is provided for fluidly connecting each of said inlet ports. A slide is movably received within the lap assembly to permit reciprocal motion. The slide alternately blocks and unblocks the metered passageway in response to a predetermined pressure across one of the respective inlet ports, in order to equalize the pressure differential between the ports.

Abstract: The invention provides an improved pipeline pulsation dampener, including a pressure vessel divided by a diaphragm of elastomeric material into first and second pressure zones. The first pressure zone is connected to a pipeline and receives any undesired pressure changes in the pipeline through a first flow passage in the pressure vessel, while the second pressure zone receives a second fluid at a preselected pressure. The diaphragm has a reinforcing insert for bridging the first flow passage to support the diaphragm when the pressure of the second fluid in the second pressure zone exceeds the pressure of the first fluid in the first pressure zone to restrain the diaphragm from extruding through the first flow passage. The reinforcing insert is encased in the elastomeric material of the diaphragm to prevent the insert and the bond between the elastomeric material and the insert from being exposed to the fluid being pumped.

Abstract: An accumulator for an anti-lock brake system includes a valve body portion defining an accumulator chamber, an accumulator piston slidably disposed within the accumulator chamber, a spring, and a cover. The accumulator chamber has a fluid inlet for connection to a source of pressurized fluid at a first end of the chamber. The chamber has a second end open to atmosphere. The accumulator piston separates the first end of the chamber from the second end of the chamber. The spring is disposed in the accumulator chamber between the piston and the second end of the chamber and biases the piston toward a first position. The cover closes the second end of the chamber and atmosphere and has micro-porous structure. The micro-porous structure is configured to block water molecules and to pass constituent molecules of air, thereby enabling air to be communicated across while preventing the intrusion of water into the chamber through the second end.

Abstract: An improved brake equalizer apparatus for equalizing fluid pressure and damping shock waves or pressure surges in fluid lines of a fluid pressure-actuated system, such as a hydraulic brake system. The apparatus has a shorter reaction time than a conventional brake equalizer, and can be manufactured with smaller overall length and weight. An important feature of the apparatus which results in reduced brake equalizer reaction time is an improved brake equalizer piston. The piston of the invention is shorter than a conventional brake equalizer piston (the ratio of the inventive piston's length to the length of the shock absorber which it abuts is substantially less than 0.5, and is preferably equal to about 0.23). The piston of the invention is also lighter than a conventional brake equalizer piston, and is preferably made of a hard, non-compressible, self-lubricating material.

Abstract: An I-type counterflow absorber for directly connecting with a piping system to absorb the impact force and noise resulting from water hammering in the piping system. It includes an outer tube, an inner tube, a valve member and a buffer mechanism. The inner tube forms a water passage with the piping system. The valve member is moveable and covers one end of the inner tube. The buffer mechanism is located between the inner tube and the outer tube, and has a damping chamber and an air chamber for absorbing the impact force and noise resulting from water hammering in the piping system. It can effectively protect the pumping device and piping end from water hammering damage.

Abstract: A shock absorber in a liquid conduit (4) is provided. The shock absorber comprises a closed liquid tank (10), which is partly filled with gas and has a joint means (11) connected to the conduit (4). Via the joint means, liquid can flow to and from the tank (10) for compressing and decompressing the gas. The joint means (11) comprises a check valve means which, in its forward direction, permits a substantially free liquid flow from the conduit (4) to the tank and, in its rearward direction, permits throttled liquid flow from the tank to the conduit.

Abstract: An adaptive hydropneumatic pulsation damper is especially suited for hydraulic systems subject to pulsation with a strongly variable operating pressure. Because of good damping action, the pulsation damper makes a hydraulically firm coupling possible between hydraulic system elements, e.g., a pressure source and a consumer.

Abstract: A shell constituted by an outer shell and an end plate. The end plate has a port in communication with a liquid chamber. A bladder divides an internal space of the shell into a liquid chamber and a gas chamber. A gas is introduced into the gas chamber without the provision of a gas inlet in the outer shell located on the side of the gas chamber. For example, an accumulator is assembled by combining the outer shell, the end plate and bladder under atmosphere of a high pressure gas.

Abstract: A gas or liquid pulsation dampening system is provided which minimizes the size of the vessel required to effectively dampen gas or liquid pulsations while maximizing the dampening effect. The gas or liquid pulsation dampening system comprises a novel spring pulsation dampening valve and a vessel for housing the valve and for containing a gas or liquid. The vessel is equipped with a pulsating gas or liquid inlet and a dampened gas or liquid outlet, and a support for holding the spring pulsation dampening valve in axial alignment with the dampened gas or liquid outlet. The spring pulsation dampening valve comprises first and second ends, a stationary outer sleeve, and a spring loaded gas or liquid flow restricting tube positioned in the interior of the stationary sleeve for axial movement therein.

Abstract: Disclosed is a means for automatically regulating water pressure in water pipe mainly including a tube connected to and between two sections of water pipes. A plurality of pressure-reduction members and springs are alternately disposed in the tube. The pressure-reduction members have an external diameter slightly smaller than an inner diameter of the tube. Grooves or through holes are formed on a circumferential surface or bottom surface, respectively, of the pressure-reduction members for water to pass through. Whereby, when a small volume of water with low water pressure flows into the tube, the springs are in an extended state, allowing water flowing into the tube to freely pass the grooves around the pressure-reduction members and to enter into the springs via circumferential clearances of the springs, and finally flows out of the tube via the through holes on the lowest pressure-reduction member in the tube.

Abstract: The invention sets forth a hydraulic accumulator-damper which facilitates design and assembly of a brake system with a traction control for a motor vehicle. To this end, an end wall of a piston in a housing of the hydraulic accumulator is provided with a damping diaphragm. Between the damping diaphragm and the housing end wall, the damping diaphragm encloses a damping chamber into which a throttle bore discharges through the housing end wall.

Abstract: A compensating device, especially for railway car transformers, has a compensation receptacle including a fluid-carrying connection with the interior of the housing of the transformer. In the compensation receptacle, a compensating plate is movable along an adjusting axis under the influence of an accumulator, and is in engagement with the transformer oil carried in the compensation receptacle. A guide arrangement for controlling the movement of the compensating plate includes two sheathings slidable counter to one another. One sheathing is connected with the compensating plate. The other sheathing is connected with the stationary parts of the compensation receptacle. At least one of the sheathings cooperates with a detent surface on the compensating plate or on the compensation receptacle. The compensating device can be arranged in a railway car in the underfloor compartment.

Abstract: Pneumatic medium in a vehicle brake system is applied against one side of a flexible membrane (48) folded about an end portion of a piston (40) resiliently positioned against a coil spring (36). Pressure peaks in the pneumatic medium are damped by the membrane motion against the spring-loaded piston (40) preventing so-called lockup.

Abstract: An improved hydraulic accumulator is introduced wherein a valve mechanism is used to seal a hydraulic fluid before the pressure charged piston reaches the end of the accumulator to minimize the loss of compressed gas by eliminating the pressure differential when the piston is fully extended, thereby prolonging the fatigue life of the accumulator vessel. Reduction of the pressure loading on the vessel will also prolong the life of the piston seals and metal bellows effectively extending the accumulator life and effectively allowing design for weight reduction and preservation of the integrity of the complete hydraulic or pneumatic system.

Abstract: The invention pertains to a hydropneumatic suspension system, in particular for motor vehicles, with at least one hydraulic strut (2) that acts upon at least one hydropneumatic piston-type accumulator (6) during deflection and rebound movements. The piston-type accumulator (6) has a separating piston (22) that separates the hydraulic accumulator chamber (24) from a spring chamber (26) containing a compressible medium, in particular a gas. A hydraulic pressure (P.sub.h) acts upon the separating piston (22) from the side of the accumulator chamber (24) and a pneumatic pressure (p.sub.p) acts upon the separating piston from the side of the spring chamber (26), with at least one supplementary spring force (F.sub.F ;F.sub.F1 ;F.sub.F2) acting upon the separating piston (22) of the piston-type accumulator (6) in addition to the forces (F.sub.h,F.sub.p) resulting from charging the separating piston (22) with the hydraulic pressure (P.sub.h) and the pneumatic pressure (p.sub.p).

Abstract: A brake module including an integrally formed manifold and accumulator provides a way of simplifying assembly, increasing packaging flexibility and reducing the total number of individual components.

Abstract: In a seal oil system utilized to supply oil to shaft seals of a generator for preventing pressurized gas inside the generator from escaping through an interface of the generator shaft and the generator frame, wherein seal oil is supplied to said seals via a main supply line at a predetermined pressure, the improvement comprising at least one differential pressure accumulator including a barrel having an upper inlet end and a lower outlet end, and a piston slidably mounted in said barrel and movable between said inlet end and said outlet end; a first chamber above said piston having liquid supplied thereto at a pressure equal to internal gas pressure of the generator; a second chamber below said piston charged with generator seal oil; and means for enabling said at least one accumulator to discharge generator seal oil to said main supply line upon temporary decrease in pressure in said main supply line.

Abstract: The pressurized hydraulic piston-cylinder device with an internal volume variation compensation device includes a hydraulic pressure cylinder; a piston movable in the pressure cylinder; a cap closing the functional end of the pressure cylinder; and a liquid contained in the hydraulic pressure cylinder between the cap and the movable piston. The cap includes a substantially cylindrical hollow body member which fits snugly fits over the functional end of the pressure cylinder and an end wall at another end opposite from the open end, and a resilient compensating diaphragm having an outer surface facing the pressure cylinder and an inner surface facing the end wall of the hollow body member. The resilient compensating diaphragm and the end wall bound a compensating chamber having a variable volume depending on a pressure of the liquid contained in the hydraulic pressure cylinder and acting on the outer surface of the resilient compensating diaphragm.

Abstract: An ultrasound testing device for gas pressure accumulators is used to test a predeterminable set position that can be taken by a movable separating element inside an accumulator filled with gas and connected to a fluid circuit. The separating element has at least one testing body associated with a visible mark which indicates the set position of the separating element. An ultrasound testing device on a testing body can be set on the accumulator in alignment with the visible mark. This testing device allows a plurality of accumulators of the same type to be tested for their predeterminable gas pressure set value, which corresponds to the gas pre-filling pressure, by a single hand apparatus. This kind of test is economical and achieves reliable results.

Abstract: A pressure sensor die is provided with a flexible membrane and a plunger which combine to amplify a low pressure signal while also providing media isolation between a fluid being measured and the internal components of a pressure sensor. One embodiment of the pressure sensor disposes an end of the plunger in direct contact with a pressure sensor die while another embodiment disposes an elastomeric diaphragm between the plunger and the pressure sensor die. This second embodiment creates a chamber between the plunger and the pressure sensor die in which a fluid is captured by movement of the plunger. The captured fluid is decreased in volume by movement of the plunger and the resulting increase in pressure in transmitted to a pressure sensitive portion of a pressure sensor die. The device is particularly useful in conjunction with applications where media isolation is required between the fluid being measured and the components of the pressure sensor, such as kidney dialysis machines.

Abstract: A method for maintaining the pressure of a compressible fuel resident in a reservoir above a predetermined minimum including withdrawing compressed air from an internal combustion engine's combustion chamber, further compressing that withdrawn air, transmitting that further compressed air to an expandable air compartment which, with a fuel compartment having an outlet, occupies the interior of a reservoir. Apparatus for maintaining the pressure of a compressible fuel above a predetermined minimum including a reservoir having an air compartment and a fuel compartment separated by a moveable barrier, an internal combustion engine having a combustion chamber, means for transmitting air from the combustion chamber to the air compartment, a compressor for compressing the transmitted air, and a valve for obstructing air transmission when the fuel compartment's pressure exceeds a predetermined maximum.

Abstract: This invention relates to a solenoid valve where a volume governor which governs the hydraulic flow is inserted coaxially to the valve closure member into the valve accommodating body of the valve. The volume governor is integrated by way of series connection between the first pressure medium connection, emanating from a pressure medium source, and the valve closure member. A reduction of the valve operating noises is ensured with a smallest-requirement-answering structural size, thus the control noises being prevented from propagating over the entire connected system.

Abstract: A water hammer arrester comprises a cylindrical body housing a piston for free sliding reciprocal movement and a connector for connection to a water conduit system which carries water under pressure. An abutment-bumper combination is interposed between piston and connector to avoid the ping which would be produced is these two elements of the assembly were to collide during reciprocation of the piston.

Abstract: An accumulator for use in a hydraulic control circuit comprises a check valve for allowing a suction of air into a working fluid pressure chamber from the atmosphere. The check valve includes a valve cylinder integrally formed with a member for defining the working fluid pressure chamber. The check valve includes a check ball movable within a bore of the cylinder, and a ball stopper having an outer peripheral surface formed with mesh-like grooves press fitted into the bore to retain the ball within the bore.

Abstract: An accumulator piston is formed as a two-piece plastic molding for simplifying its construction and for cost reduction and weight reduction purposes. The piston has a radially stepped construction in which each step includes a radial flange carrying an annular elastomeric sealing element. The sealing elements have deformable, resilient lips which slidably engage the side surfaces of a stepped cylinder in which the piston reciprocates. One of the elastomeric sealing elements is molded to an annular insert member that is seated in an annular recess formed in one end of the main piston body. The two-piece piston construction facilitates installation and removal of mold cavity members relative to the respective elastomeric sealing elements such that the mold cavity members can be of simplified economical construction.

Abstract: A pulsation damper and noise attenuator assembly comprising a housing having an inlet port and an outlet port fluidly connecting the interior of the housing to the flow path of the fluid flow system. A base is mounted to the housing and comprises a vent fluidly connecting the interior of the housing to an external fluid source. A sealing member such as an expandable bellows or piston is seated within the housing and creates a fluid tight seal between the fluid flow path and the external fluid source sealing member. The external fluid biases the sealing member in a forward direction. The sealing member acting against the N.sub.2 fluid under pressure absorbs the full force of the hydraulic shock waves or pulsation within a high pressure fluid flow system as the assembly is mounted directly within the flow path of the fluid. The shock wave is exposed across the full face of the sealing member and dampened prior to the fluid continuing along the flow path.

Abstract: A low pressure accumulator assembly for use with a fluid pump comprises a pump housing with a longitudinally extending chamber having a base with a fluid flow opening. An accumulator is secured in the pump housing chamber. The accumulator includes an accumulator housing with a longitudinally extending bore. A piston is biased outwardly of the bore to selectively engage the base of the pump housing chamber. A protrusion extends outwardly from the piston to limit an area of engagement between the piston and the base so that fluid flowing from said opening into the chamber may engage a greater area of the piston.

Abstract: A device for smoothing pressure fluctuations from a liquid pump, the device having a liquid chamber connectable to the pump and having an air chamber connectable to a source of pressurized air through an internal valve, the liquid chamber being separated from the air chamber by a diaphragm, the diaphragm connected to the valve, to permit pressurized air to equalize liquid pressure surges and to supplement liquid pressure drops, and to automatically adjust for changes in average liquid pressure delivery conditions.

Abstract: A piston-type accumulator has a cylindrical outer case, a piston slidably fitted in the cylindrical outer case, and a cap mounted in an open end of the outer case. The piston-type accumulator includes a cap attachment structure in which said cap has two larger- and smaller-diameter steps on an outer circumferential surface. The cylindrical outer case is deformed by staking on said larger- and smaller-diameter steps. The piston has an annular recess defined in an outer circumferential surface thereof axially between two seals thereon. The annular recess communicates with the atmosphere through a collapsible tube.

Abstract: An accumulator disposed in an actuating circuit for a fluid operated friction device provides a first time pressure relation during engagement of the device and a second time pressure relation during disengagement of the device.

Abstract: An economical to manufacture and simple to install and remove gas charged fluid pressure accumulator including a cup-shaped accumulator body with an integral dome at one end and an integral in-turned annular lip at the other end, a piston slidably disposed in the accumulator body, and an external screw thread on the accumulator body. The accumulator body is screwed into a threaded counterbore until the annular lip bears against a bottom wall of the counterbore with a fluid port of the manifold inside of the projection of the lip on the bottom wall. A seal ring in a groove in the bottom wall of the counterbore bears against the annular lip to seal the chamber of the accumulator defined between the bottom wall and the piston.

Abstract: A pulsation damper and noise attenuator assembly comprising a housing having an inlet port and an outlet port fluidly connecting the interior of the housing to the flow path of the fluid flow system. A base is mounted to the housing and comprises a vent fluidly connecting the interior of the housing to the atmosphere. A piston seated within the housing creates a fluid tight seal between the fluid flow path and the vented atmospheric pressure. Belleville springs bias the piston in a forward direction. The piston absorbs the full force of the hydraulic shock waves or pulsation within a high pressure fluid flow system as the assembly is mounted directly within the flow path of the fluid. The shock wave is exposed across the full face of the piston and dampened prior to the fluid continuing along the flow path.

Abstract: A pulsation damper and noise attenuator assembly comprising a housing having an inlet port and an outlet port fluidly connecting the interior of the housing to the flow path of the fluid flow system. A base is mounted to the housing and comprises a vent fluidly connecting the interior of the housing to an external fluid source. A sealing member such as an expandable bellows or piston is seated within the housing and creates a fluid tight seal between the fluid flow path and the external fluid source sealing member. The external fluid biases the sealing member in a forward direction. The sealing member acting against the N.sub.2 fluid under pressure absorbs the full force of the hydraulic shock waves or pulsation within a high pressure fluid flow system as the assembly is mounted directly within the flow path of the fluid. The shock wave is exposed across the full face of the sealing member and dampened prior to the fluid continuing along the flow path.

Abstract: Motive power unit comprising an internal combustion engine associated with a hydrostatic transmission, in particular for fitting to an automobile vehicle.In accordance with the invention, the motive power unit comprises an internal combustion engine (60) mechanically coupled to a hydrostatic transmission device comprising at least one pump (12) with a piston (13) driven by said engine and an elastic accumulator coupled to the or each pump; the pumps being connected to a volumetric motor (14).