Abstract: A control valve 44 for use in a fluid pressure operated motor 10 to control the communication of fluid between first and second chambers 34 and 36. The control valve 44 includes a plunger 58, a disc 46 and a retainer 70. The retainer 70 has a cylindrical body 82 with an inwardly projecting lip of which section 84 engages and holds the peripheral surface 48 against shoulder 78 on the hub 26 and an end section 94 which acts as a stop to limit the movement of plunger 58 in bore 38 when the valve 44 is in the released position. Tabs 100, 100'. . . 100.sup.N on sleeve or cylinder 82 are located in groove 102 to lock the retainer 70 in place. In response to an input, push rod 56 moves plunger 58 to allow disc 46 to move and initially interrupt communication of a first fluid between the first and second chamber 34 and 36 and thereafter permit a second fluid to flow into the second chamber 36.

Abstract: A brake booster for automotive vehicles comprises a low-pressure casing sealingly subdivided into a low-pressure chamber and a working chamber by an axially movable wall. The two transverse end walls of the low-pressure casing are interconnected by a central reinforcement tube integrally formed with a master cylinder. The actuating piston of the master cylinder is connected to a guide piston which is guided in the reinforcement tube and which receives a rubber-elastic reaction disc in an end thereof remote from the master cylinder. A control valve casing is axially movable in the reinforcement tube, bears axially against the reaction disc and is connected to the movable wall by radial ribs extending radially through longitudinal slots in the reinforcement tube. The radial ribs are connected to a ring which encompasses the reinforcement tube and which is secured in a bowl-shaped hub member of the movable wall.

Abstract: A vacuum type brake booster device is provided which comprises a booster shell of substantially elliptical shape in transverse cross section, a booster piston of similar shape as the booster shell and accommodated therein for axial reciprocating movement, and a diaphragm secured about the outer periphery thereof to the booster shell and about the inner periphery to the booster piston to divide the interior of the booster shell into a first working chamber in communication with a vacuum source and a second working chamber adapted to be selectively placed in communication with the first working chamber or the atmosphere by a switching valve. The diaphragm is also shaped substantially elliptically in transverse cross section, and includes a pair of opposite straight peripheral wall sections and a pair of opposite arcuate peripheral wall sections interconnecting the straight wall sections; the arcuate wall sections have a wall thickness greater than that of the straight wall sections.

Abstract: A power steering system for motor vehicles, wherein a steering nut, connected to a steering worm in such a manner that the steering worm is driven thereby, is rotatably and axially non-displacably mounted in a working piston and is also provided with a control arm passing through both a radial recess in a working piston and a radial opening in a cylinder housing that receives the working piston. An end of the control arm which is radially outermost with respect to an axis of the piston actuates a spool valve for adjusting the working pressure. Two corresponding followers are provided for defining the end stroke positions of the working piston. The followers are mutually engagable to lower or shut off a working pressure in the system. One of the followers is disposed opposite the working piston relative to the piston axis and the other is located opposite the cylinder housing relative to the cylinder axis with a zero motion.

Abstract: In a pulse modulated servosystem having solenoid activated on-off valves governing the amount of fluid in two variable volume chambers of a double-acting piston-cylinder unit any limitation of the accuracy due to inertia of the valves is eliminated by influencing both chambers in opposite directions.

Abstract: In the prior art, a master brake cylinder is connected to a brake booster by a flange and nut and bolt arrangement. According to the present invention the connection can be made with a reduced number of parts and the large flange of the master cylinder can be eliminated. This is accomplished by providing the connecting end of the master cylinder with a circular groove and the adjacent end of a reinforcing tube of the booster is positioned to encompass the grooved end of the master cylinder, the reinforcing tube having protuberances formed therein to grip the circular groove.