Dual circuit power assisted brake - has switch to restore brake pedal position in event of one circuit failure

摘要

The brake pedal is pivoted at its upper end to a fixed point (35) and actuates the brake servo via a push rod linked to the brake pedal (4) by a forked member (24) and pivot pin engaging in an elongated slot (27) which allows the pivot pin to assume either of two positions to alter the brake pedal angle. The position alteration is effected by an electrical switch (52) which is automatically closed by a striker (50) fixed to the forked member (24) in the event of the pedal travelling an excess distance owing to one of the brake circuits failing. The switch actuates a magnetic valve (54) fitted to the depression pipe (7, 8) leading to the depression chamber (18) of a piston and cylinder arrangement (5).