Patent ID: 7040090

Claim:
A power assisted steering system for vehicles comprising: a pump which feeds to a hydraulic servo actuator and a three-way flow regulator valve which is located at the junction between the pump and the servo actuator; a measuring throttle in a inflow to the servo actuator, said measuring throttle being a fixed throttle; an outflow throttle located in a bypass of the servo actuator and via which excess flow of the pump is directed; the outflow throttle having a variable throttle cross section, the cross section being determined by a piston as a pressure compensator; the piston, with respect to the volume flow which passes via the measuring throttle, being charged by connection to the inflow side and, in the opposite direction thereto, by connection to the outflow side; the piston being actuated by a first actuating element which has an actuating path dependent on the actuating force and opposing force and a second actuating element having an actively variable actuating force with the effect of varying the volume flow; and the first actuating element being an elastic actuator member and the second actuating element comprising an actuating member which is adjusted as a function of the current applied.