Patent ID: 6520063
Filing Date: 2003-02-18
Classification: B60T

Abstract:
Vacuum brake booster, comprisinga vacuum chamber and a working chamber separated in a pressure-proof manner from one another by a movable wall, and a control valve having a housing, which is workingly coupled to the movable wall and in which is disposed a first valve seat, which to achieve a pressure difference at the movable wall is capable of controlling the supply of at least atmospheric pressure to the working chamber in dependence upon the displacement of an input element, which is coupled to the first valve seat, of the brake booster, an armature, which is disposed in the control valve housing and cooperates with a permanent magnet and which is selectively coupled on the one hand to the input element in actuating direction and on the other hand to the first valve seat, wherein a spring biases the armature counter to actuating direction and in the starting position of the control valve holds the armature at a first distance from the permanent magnet, and wherein the armature in the course of a movement towards the permanent magnet, when it is less than a previously fixed, second distance, which is less than the first distance, away from the permanent magnet, is pulled counter to the force exerted by the spring upon the armature and with simultaneous uncoupling, in actuating direction, to the input element into abutment with the permanent magnet, characterized in that the spring, which biases the armature counter to actuating direction, selectively is selectively mechanically coupled to the input element in such a way as to brake the return stroke motion of the input element, which follows a detaching of the armature from the permanent magnet, before the input element has completed its maximum possible return stroke relative to the control valve housing.