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.