Abstract: A process for transmitting or storing energy in which a gasseous working fluid is compressed and cooled, relative to isentropic compression, by a coolant. The energy used to perform the compression is recovered by expansion, while heat from the coolant is used to reheat the working fluid, thus maximizing efficiency.

Abstract: Pump ports 9p, 10p, 11p, 13p of boom, arm, bucket and first travel directional control valves 9-11, 13 are connected to first and second hydraulic pumps 1a, 1b through feeder lines 93a, 93b; 103a, 103b; 113a, 113b; 133a, 133b. Auxiliary valves 91a, 91b; 101a, 101b; 111a, 101b; 131a, 131b controlled respectively by proportional solenoid valves 31a, 31b; 32a, 32b; 33a, 33b; 34a, 34b are disposed in those feeder lines. The auxiliary valves each have a function as a reverse-flow preventing function and a variable resisting function including a flow cutoff function, whereby a joining circuit and a preference circuit can be realized in the closed center circuit with a simple structure and further, a preference degree and metering characteristics can be set independently of each other during the combined operation of plural actuators.

Abstract: In a torque converter, in order to reduce the cost, simplify the manufacturing process and ensure the centering precision of of the stator relative to the outer race of a one-way clutch, the stator and the outer race of the one-way clutch have first engaging surface portions preventing relative rotation therebetween and second engaging surface portions providing concentricity therebetween. The first and second surface portions are axially offset from each other.

Abstract: A fluid-controlled actuator assembly for a gearbox of a vehicle. The actuator is provided with a four-position mobile element, with a first and a second chamber separated in a sealed manner from the mobile element, and with auxiliary positioning elements suitable for determining a stop position of the mobile element. Also included are first and second solenoid valves suitable for supplying pressurized fluid respectively to the first and to the second chamber and for discharging it from them, such that when the fluid is supplied into both the chambers, the mobile element is maintained by the auxiliary positioning elements in the stop position. When the fluid is supplied into one of the chambers and is discharged from the other, the mobile element adopts one of two lateral positions with respect to the stop position.

Abstract: A multiple hydraulic distributor device, having an antisaturation function wherein flow of hydraulic fluid is divided independently of load, which includes a hydraulic distributor device having a number of distributor devices assigned to controlling respective loads, which are stacked up face to face against each other as a stack and individually arranged in such a way that the stack has a common line passing through the stack for supplying working fluid under pressure originating from a source including a pump associated with a flow/pressure control device, a common return line for returning working fluid to a tank, and a common transmission line for transmitting control fluid at a pressure of highest load towards the control device for controlling the pump; a shut-off device arranged in the transmission line between a first group of distributors for which the transmission line is connected to the flow/pressure control device for controlling the source, and at least a second group of distributors for which t

Abstract: A pneumatic brake booster using first and second sources of air pressure and having a rigid casing (3) divided into at least first (3a) and second (3b) chambers by a leaktight moving partition (4). The moving partition (4) being capable of being urged by a pressure difference brought about by the actuation of a valve (7). Valve (7) having a tubular shut-off member (70) which together with an internal face (510) of a piston (5) delimits a compensation volume (74) that is permanently connected to the second chamber (3b). The shut-off member (70) of valve (7) facing first (71) and second (72) seats. The shut-off member (70) having a continuous and leaktight surface while the compensation volume (74) is connected to the second chamber (3b) by an axial piercing of a portion (8) of a greater thickness of a cylindrical wall (51) on the pneumatic piston (5).

Abstract: A master cylinder (12) and pneumatic brake booster (10) assembly for use in a motor vehicle. The pneumatic brake booster (10) has a casing (15) fastened to a wall (16) which separates a cabin (H) from a front compartment (C) of the motor vehicle. The pneumatic brake booster (10) is actuated by control rod (18) having a rear end which is connected to a brake pedal located in the cabin (H). The master cylinder (12) has a body (20) formed with at least one flange (22) for fastening the master cylinder (12) onto the front wall of the casing (15). An aggressive element (26) extends from the body (20) and engages the casing (15) on rotation of the master cylinder (12) in response to a torque being applied to the master cylinder (12). Engagement of the aggressive element (26) with the casing (15) will attenuate the communication of the torque into the control (18).

Abstract: A positioning drive having a hydraulic motor with a cam disc which is rotatable with a motor shaft and has a cam, a control valve which, with the hydraulic motor forms a unit with a housing and has a valve piston which is displaceable between several positions, a control element via which the valve piston can be supported on the cam disc, and an adjustment element which is operatively disposed between the control element and the valve piston and coaxial to the latter. The relative position between the valve piston and control element is variable by relative adjustment of the adjustment element with respect to the valve piston. The position of the adjustment element relative to the valve piston is securable by a releasable locking element. The outer of the two parts, valve piston and adjustment element, is guided outwards through the housing, and the locking element is accessible externally of the housing.

Abstract: An improved pressure-compensated hydraulic system for feeding hydraulic fluid to one or more hydraulic actuators. A remotely located, variable displacement pump provides an output pressure equal to a control input pressure plus a constant margin. A pressure compensation system requires that a load-dependent pressure be provided to the pump input through a load sense circuit. An isolator transmits the load-dependent pressure to the pump control input, while preventing fluid from leaving the load sense circuit and flowing to the remotely located pump. A valve section, which controls the fluid flow between the pump and actuator, has a pressure compensating valve with a piston and spool controlling a pressure differential across a main control valve orifice by moving within a bore in response to a pressure differential between a pump supply pressure and the load sense pressure.

Abstract: The hydraulic control system disclosed herein employs a pair of combination poppet/spool valves to control the operation of a hydraulic cylinder driven from a bidirectional pump. Flow introduced through the source port of one valve lifts the poppet of the other valve on its way to one side of the cylinder which in turn opens a throttling port to modulate return flow from the other side of the cylinder.

Abstract: The present invention relates to a method of controlling a speed change of a hydraulic driving apparatus for a vehicle and to a speed changing device which provide excellent traveling efficiency and controllability. To this end, the method of controlling a speed change comprises discriminating between at least a powering travel and a braking travel from an accelerating amount (.theta.) and rotational speed of a hydraulic motor (50) for controlling. At the time of the powering travel, a directional control valve (21) can be fully opened in response to the rotational speed (.omega.out) of the hydraulic motor (50) and the accelerating amount (.theta.). In addition, the speed changing device comprises an accelerating amount detection sensor (61a), a motor rotational speed sensor (52) for detecting a vehicle speed (V), and a control device (60) for discriminating, from the accelerating amount (.theta.) and the vehicle speed (V), between the powering travel and the braking travel for providing a control.

Abstract: A valve assembly (10) for controlling a pneumatic brake booster comprises a valve housing (16) with a first and a second valve seat (18, 20) as well as with a valve body (26) adapted to be applied to both valve seats (18, 20). In one position of an operating member (24) the valve body (26) is lifted off the first valve seat (18) only, while in another position of the operating member (24) it is lifted off the second valve seat (20). Radially outside the valve housing (16) an annular third valve seat (64) and a control sleeve (60) surrounding the valve housing are arranged, which as an additional valve body can be axially moved by means of the operating member (24) relative to the valve housing (16).

Abstract: A refueling cart, for refueling large aircraft at a major airport having pressurized fuel hydrants at loading/unloading aprons, includes auxiliary facilities on the refueling cart that are usually powered by compressed air that is obtained from compressed-air bottles carried on the cart. In order to avoid the labor and annoyance of checking and refilling the bottles of compressed air, a small air compressor is carried on the refueling cart and is powered by a hydraulic motor that is in turn powered by the flowing pressurized fuel. A variable-flow valve is placed in the path of the fuel flowing from a hydrant to the airplane. The pressure generated across the variable-flow valve by the flowing fuel pushes some of the fuel in a path that bypasses the variable-flow valve. That bypass path includes the hydraulic motor, and the bypassing fuel at the pressure difference generated by the variable-flow valve drives the fluid motor. The fluid motor, in turn, drives the air compressor.

Abstract: A control system (10) for a limited stall load actuator (60) comprises a servo pressure regulator (20), solenoid valve (40), relief valve (30) and a shuttle valve (50) connected with a piston actuator 60 such that when source pressure P1 is declining the servo pressure regulator (20) will open to permit more flow and maintain a minimum actuation force effected by the actuator (60), and should there occur a failure of the servo pressure regulator (20) that would permit high source pressure to be communicated to the control system (10), the relief valve (30) will operate to limit the amount of high pressure communicated to the control system (10) such that the actuator (60) will attain no greater than a predetermined maximum output force.

Abstract: A waterpower machine has a vertical cylinder, the lower end of which is open, a piston which is vertically reciprocable in the cylinder, a water chamber provided at the lower end of the cylinder wherein the water chamber has a water inlet and a water outlet, an inlet valve for controlling water inflow into in the water chamber through the water inlet, and an outlet valve for controlling water outflow from the water chamber through the water outlet. Both the water inlet and the water outlet are opened towards the periphery of the water chamber over the major portion of the water chamber circumference. The water inlet is at a different level from that of the water outlet. The inlet valve and the outlet valve comprise respective ones of a pair of annular valve members which are concentric with one another and with the cylinder and axially moveable between a closed position and an open position.

Abstract: An hydraulic system has an hydraulic cylinder connected to a reversible pump by a first fluid line. A check valve assembly is connected in the first line and in a second line extending from the pump to a tank. The check valve assembly has a ball that seats on a conical valve seat to enable flow of fluid from the pump to the cylinder but to prevent flow in the opposite direction. A shuttle member in the check valve assembly is displaced by fluid pressure in the second line when the pump is reversed to unseat the ball and allow flow from the cylinder in the opposite direction via the pump to the tank.