Abstract: A vacuum brake booster (10) has a vacuum chamber (18) and a working chamber (20) separated from one another in a pressure-proof manner by a movable wall (16). A control valve (22), which comprises a housing (24) workingly coupled to the movable wall (16), has a first valve seat (50), which is disposed in the housing (24) and to achieve a pressure difference at the movable wall (16) is capable of controlling the supply of at least atmospheric pressure to the working chamber (20) in dependence upon the displacement of an input element (26) coupled to the first valve seat (50). For improved boosting of the brake force during emergency braking operations, an armature (38), which cooperates with a permanent magnet (40), is provided in the control valve housing (24) and is rigidly coupled on the one hand to the actuating element (26) in actuating direction and on the other hand to the first valve seat (50).

Abstract: A vehicle brake system with an electronically controllable brake booster, comprising an actuation member (70, 80) transferring the actuation travel of a brake pedal to a master cylinder, which is allocated a travel limiting element (82) accepted between two abutment faces which limits the actuation travel of the actuation member (70), and a switching element (85) which upon an actuation movement of the actuation member (70) can be activated by one of the abutments (91, 91a) in order to issue a signal to the controller of the brake booster, with the traveling limiting element being arranged on the actuation member (80) between two collars (83, 84), and a carrier (86) accepting the switching element (85) being arranged between the travel limiting element and one of the collars.