Abstract: A pressure intensifier for fluids has an intensifier piston with a high-pressure piston and a low-pressure piston having a greater diameter than the high-pressure piston. The pistons are moveable in a high-pressure cylinder and a low-pressure cylinder, respectively, and move together. The high-pressure cylinder is connected to a high-pressure connection. A first control line is connected to a supply connector. A second control line is connected to a control valve having first and second switching positions. A first connection connects the control lines. The low-pressure cylinder is connected via the control valve in the first switching position to a supply connector and in the second switching position to a return connector. The switching positions are controlled by the intensifier piston. The intensifier piston opens or closes the first connection between the control lines. The first connection is arranged completely within a movement stroke of the high-pressure piston.

Abstract: A pressure intensifier for fluids has an intensifier piston with a high-pressure piston and a low-pressure piston having a greater diameter than the high-pressure piston. The pistons are moveable in a high-pressure cylinder and a low-pressure cylinder, respectively, and move together. The high-pressure cylinder is connected to a high-pressure connection. A first control line is connected to a supply connector. A second control line is connected to a control valve having first and second switching positions. A first connection connects the control lines. The low-pressure cylinder is connected via the control valve in the first switching position to a supply connector and in the second switching position to a return connector. The switching positions are controlled by the intensifier piston. The intensifier piston opens or closes the first connection between the control lines. The first connection is arranged completely within a movement stroke of the high-pressure piston.

Abstract: The handwheel of a vehicle is connected to a handwheel shaft which in turn is connected through a load torque isolating device (overrunning clutch) that acts in either of the two directions of rotation and is connected to a steering shaft that controls a hydraulic arrangement. The hydraulic arrangement controls a steering motor that in turn controls the direction of turning of the vehicle. A second motor is drivingly connected to the overrunning clutch to rotate the steering shaft when the second motor is operated but when the steering is controlled by the handwheel, movement of the second motor is prevented. The second motor is operable from a location remote from the vehicle. The overrunning clutch includes a hub connected to the steering shaft and is movable by the handwheel shaft, the hub being wedgable against the clutch housing for being driven by the second motor by two jamming rollers that each acts in one direction of rotation and can be released by rotating the handwheel shaft.

Abstract: A continually operating fluid pressure amplifier having a reciprocating piston system comprising a broad low pressure piston and a narrow high pressure piston, of which the latter, together with its piston cylinder, is arranged as a three-way pilot valve for operating a bistable control valve that controls the reciprocation of the piston system. The control valve has a primary valve slide controlling the said reciprocation and an auxiliary slide operable to open and close relevant conduit connections for initial amplification of the shift control signals governing the operation of the control valve, whereby a very safe operation of the entire system is ensured. Also ensured is a rapid return stroking of the piston system, such that the produced high pressure can be maintained substantially constant.

Abstract: A control valve is opened (moved from its neutral position) by rotation of a steering wheel to conduct fluid from a pump to a steering meter device that controls the amount of fluid fed to a steering motor arrangement. When the steering motor piston has been displaced by a distance corresponding to the angle of rotation of the steering wheel, the control valve is moved by the steering meter device from its opened condition to its neutral position. A pilot valve controlled actuating device is provided to short circuit the steering meter device to permit continued fluid flow from the pump to the steering motor device and provide a mechanical braking force to the meter device to block rotation thereof and thereby the movement of the control valve to its neutral position. The braking mechanism is resiliently urged to a non-braking position.

Abstract: The invention relates to a hydrostatic steering device having a servomotor connectable to wheels to be steered. The travel limits of the servomotor are sensed with position sensors which function to operate a locking apparatus which mechanically prevents further turning of the steering wheel upon a travel limit being reached in either direction.

Abstract: This invention relates to a fluid pressure operated tool of the type having an axially reciprocatable and rotatable shaft to which a work piece such as a rock drill is attachable. The tool is driven by a planetary piston type of motor with a rotary externally toothed gear member having rotational and orbital movement relative to a surrounding internally toothed gear member. The externally toothed gear member is connected to a rotatable valve member and reciprocatable and rotatable output shaft by a cardan type shaft. The output shaft has a piston part which is subject to being alternately pressurized in opposite directions to produce the reciprocating motion.

Abstract: The invention relates to hydraulic control apparatus for a servomotor of the type utilized for vehicle steering systems. Such apparatus has a control circuit controlled by a manually operated device such as a steering wheel and a power circuit connected between the servomotor and a power source such as a hydraulic pump. The power circuit includes resetting apparatus for throttling the return flow branch in a manner so that forces applied to the servomotor in the same direction as actuation are absorbed with a minimum of reactionary movement by the valves on the return flow side of the apparatus.

Abstract: The invention relates to a hydraulic control system for a vehicle steering system or the like. The system includes two hydraulic cylinders each having a piston and a piston rod extending through one end thereof with the rod side of each piston having a smaller pressure area than the opposite side thereof. The pistons are mechanically interconnected by their piston rods. Each of the cylinders has first and second ports respectively at the nonpiston and piston ends thereof. There is a source of fluid pressure and an exhaust tank and a separate valve unit for each of the cylinders. A valve operating unit includes a steering wheel for operating the valve units in unison. The valve units have passages arranged so that for turning in either direction the first and second ports of one cylinder and the second port of the other cylinder are connected to the pressure source. At the same time the first port of the other cylinder is connected to said exhaust tank.

Abstract: The invention relates to a vehicle steering control device of the type having a housing, inner and outer rotary slide members disposed in a bore of the housing and forming a reversing switch. The housing has inlet and outlet ports and two motor ports. Four axially adjacent spaced grooves being in the interface between the bore of the housing and the outer rotary slide member with the first and fourth grooves being connected to the inlet and outlet ports and second and third grooves being connected to the two motor ports. A steering shaft is connectable to the inner rotary slide member and a measuring motor which, on actuation of the control device, is connected to the inlet port to cause the outer rotary slide member to follow the inner rotary slide member.

Abstract: The invention relates to a rotary type piston machine of the type having inner and outer relatively rotatable and orbital ring and wheel gears and a pivotal drive shaft connected to the wheel gear. The casing forms sidewalls for the gears and leakage between the wheel gear and the sidewalls is a chronic problem. The wheel gear on the side opposite from the drive shaft is provided with an annular groove and a sealing ring therein to provide sealing between the inner gear element and the adjacent sidewall. The shaft side of the wheel gear has recessed areas in the crests of the teeth thereof to provide pressure compensation for the effect of the sealing the above referred to sealing ring on the opposite side thereof.