Vehicular brake system with electronic anti-lock control and traction slip control

Claim 1

A brake system with electronic anti-lock control and traction slip control for automotive vehicles, said system comprising a power-assisted dual-circuit braking pressure generator, two circuits, each of which includes one front wheel and one rear wheel, connected to said braking pressure generator, at least one auxiliary-pressure supply system which is switched on during the control phases and which generates a controlled auxiliary pressure proportional to the pedal force during anti-lock control and an uncontrolled auxiliary pressure during traction control, said uncontrolled auxiliary pressure being limited by the pump output, valve means controlling the braking pressure in the wheel brakes and connecting the braking pressure generator and the auxiliary-pressure supply system to the wheel brakes, wheel sensors and electronic circuitries for determining the wheel rotational behavior and for generating electronic braking-pressure control signals, said valve means including one electromagnetically actuated two-way/two-position joint valve in each circuit and one electromagnetically actuated two-way/two-position individual wheel multi-directional control valve located in each of two parallel supply lines connecting the respective driven and non-driven wheels of each circuit to the joint valve of the circuit, said joint valves and said individual wheel valves, in their inoperative position, being open to permit passage of fluid therethrough, each joint valve being in series with the individual wheel valves in each circuit, a pressure-fluid return line and an auxiliary pressure supply line connected between the series connected joint valve of each circuit and the supply lines containing the individual wheel valves, a multi-directional control valve closed in its inoperative position located in each return line and leading to a pressure supply reservoir, and a non-return valve located in each auxiliary pressure supply line.