Abstract: The present invention includes a bypass apparatus for lubricant in an unregulated pressurized gearbox including: a block including a lubricant inlet in fluid communication with a pressure relief valve, wherein the pressure relief valve diverts lubricant into the gearbox or into an oil filter, wherein lubricant is returned to the gearbox when the lubricant is cold and/or pressure at the pressure relief valve is high to reduce damage to the gearbox caused by high pressure during a cold start, and when the lubricant temperature increases and the pressure is reduced the pressure relief valve closes and lubricant enters the oil filter.

Abstract: A leak mitigation system for a cooling system may include an isolation valve, a controller, and a computer-readable medium. The isolation valve may selectively isolate an expansion tank from a closed loop containing a coolant circulated by a primary pump having a pump inlet. The expansion tank may maintain the coolant at a predetermined pressure at the pump inlet in the closed loop. The controller may communicate with the primary pump and the isolation valve. The computer-readable storage medium may include instructions executable by the controller to: in response to a detection of a leak of the coolant from the closed loop, shut down the primary pump; and close the isolation valve to isolate the expansion tank from the closed loop.

Abstract: An efficient use of discharged energy of a boom cylinder is provided. A control unit has a function of receiving an output signal from a sensor provided in a boom operated valve and determining a manipulated direction and a manipulated variable of the boom operated valve, and a function of, in accordance with the manipulated direction and the manipulated variable, controlling the degree of opening of a proportional solenoid valve and operating the tilt-angle control units to control the tilt angles of a sub pump and an assist motor. An output of the assist motor is used to assist in an output of the sub pump and an output of the electric motor.

Abstract: The present invention relates to an apparatus operating a hydraulic actuator for valve, which can manually operate the hydraulic actuator for opening and closing the valve by which a flow rate is adjusted. According to the present invention, by manually operating the hydraulic actuator for opening and closing the valve, there is an advantage of manually opening and closing the valve and thus easily adjusting a flow rate of fluid flowing in a pipe, even when power is cut off. Further, according to the present invention, the hydraulic actuator for opening and closing the valve can be selectively connected with a hydraulic power pack so as to automatically open and close the valve using the hydraulic power pack according to a user's selection, or which can manually open and close the valve.

Abstract: A block manifold for a fail safe actuator system allows the actuator operation with a hand pump if electrical power were not available. A method is available to isolate fail safe solenoid valves and an accumulator from a hand pump circuit to relieve the stored energy from the fail safe circuit. An additional set of pilot operated check valves were installed between the motor driven pump circuit and the hand pump circuit. These pilot operated check valves isolated the hand pump circuit from the fail safe dump solenoid and accumulator. These pilot actuated check valves also hold the actuator in the fail safe position as long as the hand pump system was not used. There is also a hydraulic bleed circuit to relieve the accumulator stored energy when the hand pump system was used.

Abstract: An actuation device for emergency operation of a hydraulically controlled actuator includes a housing with a fluid container connected to the actuator via a connection point and to a hydraulic supply circuit of the actuator via another connection point. A separating piston is guided lengthwise inside the fluid container via a manually operated adjusting device. The piston has a control device for a through-opening joining the connection points to each other. The actuation device provides an economical and simple way of reliably controlling and monitoring the hydraulically controlled actuator in case of malfunction by an adjustment screw screwed or unscrewed on the housing. The screwing path is chosen such that the cooperating separating piston can be displaced between two end positions. The through-opening of the separating piston has a check valve which is opened at one end position and is closed at the other.

Abstract: A clutch-servo for vehicles which constitutes a working device arranged for fluid connection with a master cylinder to be operated by the vehicle's driver. The servo comprises a working cylinder unit (50) with a piston (5) arranged in a working cylinder (1), which piston is connected to the clutch's engaging mechanism, and a control valve unit (60) for the working cylinder unit (50), with a valve body (21) arranged in the valve housing (44). The master cylinder has a fluid connection with the working cylinder unit (50) and the control valve unit (60), so that the fluid in the master cylinder simultaneously exerts a force on the piston (5) and the valve body (21), in order to try to release the clutch and to move the valve body (21) in order to connect the working cylinder unit (50) to a servo pressure fluid source when the driver operates the master cylinder. According to the invention the valve unit is constituted by a slide valve.

Abstract: A brake valve (45) is disclosed of the type which permits communication from a source (11) of pressurized fluid to a brake actuator (47) in response to manual movement of a valve spool (57) from a neutral position (FIG. 2) to a power brake position (FIG. 5). In the power brake position, the valve spool permits fluid communication between a work port (53), which communicates with a brake actuator, and a brake load signal chamber (87), the brake load signal controlling the fluid output of the source. As the valve spool moves toward a manual brake position (FIG. 6) communication between the work port and the brake load signal chamber is blocked. In the manual brake position, movement of the valve spool causes a large piston (63) to displace fluid from its piston bore (73) into a piston bore (75) in which is disposed a small piston (61), the small piston being operable in response to movement of the valve spool to build brake pressure in the work port (53).

Abstract: In a system for opening and closing a main line valve by use of high pressure hydraulic fluid which is controlled from a remote location and in which the fluid passes through a hand pump located at the site of the valve, a protective lock-out system is provided for guarding against personal injury in the event the high pressure fluid should arrive at the hand pump while it is being manually operated. The lock-out system includes a small piston located in an air passageway which is positioned outwardly of the hand pump main piston chamber. This passageway extends from the top of the hand pump main piston chamber toward the IN port which receives the high pressure hydraulic fluid. The piston is connected by a shaft to a poppet valve. The high pressure fluid is applied to the under-surface of the piston and to the seat side of the poppet valve.

Abstract: The invention provides a pressure flow control valve for a booster steering system which effects an extended traverse of movement of concentric coacting valve sleeves relative to each other by a combined axial and rotary movement of the inner sleeve in order to smooth out the flow under control in pressurizing a servomotor, thus achieving an improved, or flatter, regulation curve characteristic, wherein a safe road reaction resistance to steering is effected, and wherein undesirable pressure fluctuations in the system are minimized as compared with prior art valving to reduce compressional vibration in the hydraulic system.

Abstract: A hand pump system which allows normal automatic operation of a fluid motor operator for a pipeline valve by pipeline pressure, and also provides a stand-by hand pump while may be manually connected to a pressure fluid storage in the system for operating the fluid motor operator in either direction. The hand pump is connected into the system in such manner as to prevent accidental actuation of the pump handle by a pressure surge in the pipeline.

Abstract: The invention relates to improved jack-pump devices comprising a pump with a sliding piston forming first and second pump chambers, one on each side, a jack with a sliding piston forming first and second jack-chambers, one on each side, a first valve between the pump chambers, acting unidirectionally from the second to the first pump chambers, a second valve between the first chambers of the pump and the jack, and a communication device between the second chambers of the pump and the jack, the pump and jack pistons being slidably mounted and axially aligned in the same body filled with fluid, a fixed transverse partition disposed in the cylinder body between the two pistons, and a plunger for compensating variations of volume, slidably mounted in one of the two second chambers, close to the corresponding extremity of the body.The main application is as a lifting device for regulating the height of members or parts of moving machines, of seats for chairs, vehicles, building stays, etc.

Abstract: A hydrostatic servomechanism adapted to control the direction of vehicles and self-propelled machines. The mechanism has a power circuit with at least one servopump, at least one servomotor and at least one distributor, a control circuit with a measuring pump actuated by a command element as for example a steering wheel connected by means of control conduit branches to reset mechanisms and at least one feedback simulator with a flow meter in the power circuit and a controllable throttle means incorporated between the control branches of the control circuit. The feedback simulator forms a combined feedback simulator consisting of the flow meter and the throttle means controllable in steps, the throttle means being formed as a combination of several connected controllable throttle means.

Abstract: The invention relates to an assisted hydraulic control, especially for steering all types of vehicles, and comprising a double-acting receiver or hydraulic cylinder, the piston of which forms two chambers in the cylinder, the piston rod extending into one of the chambers only and having no counter-rod extending into the other chamber. The first chamber thus has a smaller effective section than the second chamber, and the resulting asymmetry of operation of the piston and therefore of the steering is compensated by an arrangement in which the distributor valve means of the control, which couples a return conduit to the second of two actuating conduits in a first working position, isolates the return conduit and connects together the second of two pilot conduits, the second actuating conduit and the first actuating conduit in the second working position.

Abstract: A steering system .Iadd.40 .Iaddend.for an articulated vehicle .Iadd.10 .Iaddend.having a pair of double acting steering cylinders .Iadd.24, 26 .Iaddend.and power steering means .Iadd.44 .Iaddend.consisting of a pump .Iadd.48 .Iaddend.and a hydrostatic steering unit .Iadd.50 .Iaddend.to which the steering wheel .Iadd.42 .Iaddend.of the vehicle is interconnected. Control means .Iadd.46 .Iaddend.are disposed between the power steering means .Iadd.44 .Iaddend.and the double acting cylinders .Iadd.24, 26 .Iaddend.for causing fluid to be directed from the power steering means .Iadd.44 .Iaddend.to both of the first and second cylinders .Iadd.24, 26 .Iaddend.during rotation of the steering wheel .Iadd.42 .Iaddend.at a first steering ratio when the pump .Iadd.48 .Iaddend.is in operation, and at a second higher steering ratio when the pump .Iadd.48 .Iaddend.is not in operation to permit manual steering of the vehicle .Iadd.10.