Abstract: A hydraulic braking force multiplying device comprising an output member slidably fitted on a housing for actuating a piston of a hydraulic master cylinder, a working chamber defined between the housing and the output member, a valve seat member slidably fitted in an axial bore of the housing and rigidly secured to the output member, an input member slidably fitted in the axial bore and defining an intermediate chamber between the valve seat member, a valve member adapted to be actuated by the input member and having a valve portion of a valve mechanism for cooperating with a valve seat formed on the valve seat member, a pressure chamber permanently communicating with a source of pressure fluid being and being disposed in the housing and adapted to be connected with the intermediate chamber through the valve mechanism, a passage formed in the valve member for connecting the intermediate chamber with the working chamber, and a passage formed in the input member for connecting the intermediate chamber with a re

Abstract: A servo valve device in a power steering apparatus of an automobile includes a valve housing having a main valve rotatably mounted therein for rotating in response to the movement of a hydraulic power cylinder. A flap valve member is rotatably mounted in the main valve member for controlling the supply of fluid under pressure to a pair of distribution ports from a pair of injection ports. Each of the distribution ports separately communicates with a different one of the pair of injection ports through a pair of fluid passages formed in the main valve. One of the fluid passages is connected to one chamber of the hydraulic power cylinder through an annular recess formed on the peripheral portion of the main valve member, while the other of the fluid passages is connected to the other chamber of the hydraulic power cylinder through a passage formed within the flap valve.

Abstract: A steering worm shaft in operational connection with a steering wheel and communicating with an axially slidably arranged steering gear nut, which gear nut affects an additional gear member, for example, by means of a toothing, and simultaneously functions as a servo-piston or is at least fixedly connected to a servo-piston within a housing, which contains a cylinder space; the servo piston dividing a cylinder space into two operational spaces, which are separated from each other, and the steering gear nut at its outer cover is provided with an outwardly extending, axially directed lever in an area remote from the sealing area of the servo-piston; the axial width of the lever corresponding at least with the lift of the servo-piston and engaging an axial-parallel groove in the housing to allow the lever to perform a minute tilting movement relative to the housing when the steering gear nut, due to friction and rise of the worm gear nut during a rotation of the steering worm shaft, is also set into rotation, wh

Abstract: The springs associated with the control valves of a servo steering system are prestressed at least in that position of the valves where associated connections are blocked. Further, the springs are arranged supporting themselves in the valve by ends of the springs being arranged facing an activating member common to the valve and permitting the entire spring force to be received by the activating member alone. At least one component of each spring is supported by the valve housing, whereby the bias on the one component increases, based on the activating force limit during a reduction of the activating force, and reaches a maximum when power-flow between the activating member and the associated regulating spring is interrupted.

Abstract: A fluid pressure control device for controlling a servo motor is disclosed, the control device being provided with at least one pressure control valve for controlling pressure in a working chamber of the servo motor and transmitting a thrust corresponding to the pressure in the working chamber back to a power input member; operation of the pressure control valve being derived from the power input member through a lost motion coupling means.

Abstract: The instant invention concerns a pressure medium control device for controlling the working chambers of a servo-motor, whereby said servo-motor is provided with two control valves which are actuated via actuator means through relative movements between a power input member and a power output member which is connected with said power input member by means of elastic, resilient, especially pre-stressed coupling means, and whereby the servo-motor is in operative connection with the power output member and the control valves are provided with reaction areas for reflecting the developing pressures to the power input member, and/or are in operative connection with one or a plurality of corresponding reaction members, whereby the power transmission from the power input member to the control valves, which is necessary for activating the control valves, is effected via a lost motion coupling to which a further elastic resilient coupling means is parallel-switched, especially for two control valves which are arranged t

Abstract: A motor vehicle fluid power circuit is disclosed which includes a constant displacement pump driven by the engine of the vehicle, a control valve, an open center steering valve, a brake booster accumulator, and a closed center brake booster. The entire output of the pump flows through the control valve under all conditions, and the control valve selectively directs the pump output to the steering valve to assist in steering the vehicle or to the brake booster accumulator (which is hydraulically connected to the brake booster) to assist in braking.

Abstract: The steering wheel controlled valve operator in a fluid power steering system, is mechanically held in a neutral position by centering springs associated with fluid pressure controlled reaction pistons yieldably resisting movement of the control valve by the valve operator. Check valves opened in response to suction pressure, conduct fluid in by-pass relation to the control valve between a servo motor chamber and a return fluid line, the control valve connecting both servo motor chambers to the return line in the neutral position.

Abstract: A motor vehicle fluid power circuit is disclosed in which a pump driven by the engine of the vehicle assists the operator in braking the vehicle and in steering the vehicle. The circuit includes a pump, a brake booster, and a steering valve. A valve spool throttles fluid flow from the pump to the steering valve to maintain the outlet pressure of the pump at least a predetermined pressure differential above the working pressure of the brake booster. The brake booster includes a shut-off means which hydraulically isolates the pressure side of the pump from the brake booster when the brake booster reaches a predetermined shut-off pressure which is less than the relief pressure of the pump relief valve so that operation of the brake booster cannot actuate the relief valve of the pump.