Abstract: A rack-and-pinion steering system has a rack which is toothed on two sides and cooperates with two pinions. At least one of the pinions can be axially translated in dependence on forces acting between the rack and that pinion. This axial translation controls a clutch arrangement so that a servomotor continuously rotating in one direction can in each case be nonpositively coupled to one of the pinions or uncoupled from both pinions.

Abstract: A rack-and-pinion steering or control system with a servomotor, especially an electric motor, which can be coupled to the rack by way of a mechanical transmission and runs continuously in one direction is provided. The rack is designed over a certain area as a screw which interacts with a recirculating ball sleeve which can be driven in two directions of rotation by the motor. To control the direction of rotation, use is made of normally disengaged clutches which can be controlled as a function of a small displacement of the recirculating ball sleeve.

Abstract: The invention relates to a servo-assisted rack-and-pinion steering system having a helical-toothed rack and an axially movable pinion which interacts therewith and the axial movement of which controls the servomotor. The pinion is mounted on an input shaft in such a manner as to be incapable of rotation with respect to the shaft but axially movable thereon, in order to suppress the transmission of axial forces between the input shaft and the pinion.

Abstract: A servo-assisted rack-and-pinion steering system in which the rack is drive-coupled to a pinion which is mounted to move between two end positions in the longitudinal direction of the rack so that its movements control the servo motor. The end positions of the pinion are defined by two friction wheels which are driven continuously in opposite directions by the servo motor, in each case allowing an auxiliary force to be transmitted to the pinion.

Abstract: A servo-assisted rack-and-pinion steering system is provided in which the rack cooperates with a rotatable pinion. The pinion is supported in an eccentrically located opening in a circular disk rotatably mounted by rolling elements on its periphery. Pivoting movement of the pinion controls an hydraulic oil actuated servo motor. The rolling contact bearing of the disk lies in the path of flow of the hydraulic oil for the servo motor. The pinion is supported in a bearing in the opening in the disk and another bearing at an opposite side of the rack and separate from the disk.

Abstract: A servo-assisted rack-and-pinion steering system includes a rack which cooperates with a pinion which is capable of limited movement transversely or, in particular, parallel to the longitudinal axis of the rack. The movements actuate the servomotor or its control elements.

Abstract: A servo valve arrangement with a high-pressure, low-pressure and motor connection and with a pressure control valve arranged between the high-pressure connection and motor connection and a return control valve arranged between the motor connection and low-pressure connection is provided. The pressure control valve normally is closed and the return control valve normally is open. The pressure control valve can be opened by a common actuating member whilst closing the return control valve. The valve arrangement is suitable, in particular, for hydraulic power steering systems of motor vehicles with a so-called closed center.

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: A servo-steering mechanism for vehicles with a feedback of a load-dependent reaction moment onto the steering hand wheel by means of at least one reaction pressure cylinder connected with a working pressure chamber, in which a reaction pressure piston operating onto the steering hand wheel is adapted to be actuated in one direction of its piston axis by the working pressure and in the other direction of its piston axis is adapted to be supported at a support spring and is also adapted to come into abutment at a stop fixed relative to the reaction pressure cylinder, when the working pressure has been brought to a value corresponding to the prestress of the support spring; between its starting position with an unstressed support spring and its shut-off or turn-off position at the associated stop the reaction pressure piston thereby comes into additional abutment at least at one reducing spring counteracting the working pressure, whereby the reducing spring is adapted to be supported either directly or by way of

Abstract: A pressure medium servo-motor, especially for servo-steering systems, in which a working piston operating in a working cylinder is provided with a piston pressure surface actuatable by the pressure in one working pressure chamber of the working cylinder for producing a servo-force directed in the sense of the relative movement of the working piston with respect to the working cylinder; the piston pressure surface of the working piston is thereby reduced with respect to the reference value fulfilling the equilibrium condition of the piston pressure forces in the neutral position of the working piston, by a reducing piston which includes a pressure disengaging surface actuatable by the pressure in the working pressure chamber and a relief pressure surface actuatable by the pressure in a relief pressure chamber.

Abstract: A control valve for a pressure medium servo-motor of a servo-steering mechanism whose valve-adjusting member includes a reaction pressure surface that is immovable relative thereto and is adapted to be acted upon by the reaction pressure in a reaction pressure chamber connected exclusively to one of the two working pressure chambers of the working cylinder of the servo-motor; the valve-adjusting member is also connected with the reaction piston in such a manner as to enable a limited free relative adjusting path between the valve-adjusting member and the reaction piston; the reaction piston, in its turn, includes a reaction relief pressure surface which is adapted to be acted upon by the reaction pressure in a reaction pressure chamber connected exclusively to the same working pressure chamber and which is oppositely directed to the reaction pressure surface; the reaction piston is also supported with respect to the valve housing by means of a spring member which is under a prestress force while its reaction