McDougall, Hersh & Scott
Brake fluid pressure control apparatus in skid control system
 A brake fluid pressure control apparatus in a skid control system for a vehicle having at least one wheel and a brake for the wheel includes a control unit for measuring the skid condition of the wheel; a fluid pressure control valve device arranged between a master cylinder and a wheel cylinder of a brake for the wheel, the fluid pressure control valve device receiving control signals of the control unit to control the brake fluid pressure to the wheel cylinder; a hydraulic reservoir which, when the brake fluid pressure to the wheel cylinder is decreased with control of the fluid pressure control valve device, reserves the brake fluid discharged through the fluid pressure control valve device from the wheel cylinder; a pressure fluid supply conduit connecting the master cylinder with the fluid pressure control valve device; a fluid pump with motor receiving a pump drive signal of the control unit for returning the brake fluid from the hydraulic reservoir into the pressure fluid supply conduit; a switching arrangement for detecting operation of the fluid pump with motor, and generating an operation detecting signal when the fluid pump with motor effectively operates; and a pump fail detecting circuit receiving the pump drive signal of the control unit and the output of the switching arrangement, and generating a pump fail detecting signal after and when receiving the pump drive signal, and when the switching arrangement does not generate the operation detecting signal. 
Nippon Air Brake Co., Ltd.
B B B B
B60T B60T B60T B60T
inventional inventional inventional inventional
Tetsuro Hideyuki
Arikawa Yamada