Brake system with slip control

A brake system with slip control for use with an automotive vehicle having wheel brakes, said system comprising, in combination:

• a pedal-actuated, auxiliary pressure supported braking pressure generator to which the wheel brakes are connected by way of pressure medium conduits;
• a hydraulic auxiliary pressure supply system comprising a hydraulic pump, a pressure compensating and pressure medium supply reservoir, and an auxiliary pressure control valve;
• wheel sensors and electronic circuits for coupling to said vehicle for determination of the wheel rotational behavior and for generation of electric braking pressure control signals permitting control of electromagnetically actuatable pressure inlet and outlet valves inserted in the pressure medium conduits for slip control;
• wherein the auxiliary pressure control valve (23) is controlled by the braking pressure generated within the braking pressure generator (1) and, upon commencement of the slip control action, causes an auxiliary pressure proportional to the braking pressure to be built up in the auxiliary pressure supply system (23, 26), said auxiliary pressure causing hydraulically actuatable valve arrangements (27, 28, 38, 39, 45, 46) to be switched over;
• said valve arrangements, which are inserted in the pressure medium conduits leading from the braking pressure generator (1) to the inlet valves (29, 39), being open when in idle position and, upon switching over to a second switch position, hydraulically connecting the auxiliary pressure supply system (23, 26) instead of the braking pressure generator (1) with the inlet valves (29, 39) and/or the wheel brakes (31-34), wherein the hydraulic pump (26) comprises a drive motor (M) which can be started as the slip control action starts, wherein the braking pressure generator (1) is designed as a tandem master cylinder (2) with a vacuum-type booster (3) connected before it, wherein a control inlet port (21) of the auxiliary pressure control valve (23) is connected with one of two brake circuits (I, II) of said tandem master cylinder (2), wherein the switching over of the valve arrangements (27, 28 45, 46) to their second switch position causes the brake circuits (I, II) or pressure medium circuits of the braking pressure generator (1) to be cut off, and wherein the hydraulically actuatable valve arrangements (45, 46) are provided as three-way/two-position directional control valves hydraulically connecting the wheel brakes (31-34), when in idle position, with the braking pressure generator (1) and, upon switching over, with the auxiliary pressure supply system (23, 26) with a third pressure medium path in each case being locked.