Patent ID: 6079793
Filing Date: 2000-06-27
Classification: B60T

Abstract:
A motor vehicle brake system, comprising:a tandem master cylinder having a first pressure chamber and a second pressure chamber for developing brake fluid pressure in said first and second pressure chambers in response to actuation of a brake pedal;wheel cylinders mounted to front and rear wheels for developing braking forces at said front and rear wheels;electrically controlled pressure adjusting valves for adjusting brake fluid pressure in corresponding said wheel cylinders;an electrical controller for controlling said pressure adjusting valves;a first changeover valve having a first input for being connected to an output of one of said electrically controlled pressure adjusting valves for a first one of said wheel cylinders mounted to one of the front wheels, a second input for being connected to said first pressure chamber in the event of a fault and an output connected to the first one of said wheel cylinders mounted to one of the front wheels;a second changeover valve having a first input for being connected to an output of one of said electrically controlled pressure adjusting valves for a second one of said wheel cylinders mounted to the other of the front wheels, a second input for being connected to said second pressure chamber in the event of a fault and an output connected to the second one of said wheel cylinders mounted to the other of the front wheels;wherein said first and second changeover valves are controlled by said controller such that during a normal operation said pressure adjusting valves are connected to respective said wheel cylinders mounted to the front wheels by respective said changeover valves and such that during a brake system failure said first and second pressure chambers of said master cylinder are connected to respective said wheel cylinders mounted to the front wheels by respective said changeover valves.