GB1179610A - Improvements in or relating to Servo Assisted Vehicle Braking Systems - Google Patents

Abstract

1,179,610. Fluid pressure braking system. ROOTES MOTORS Ltd. 5 May, 1967 [7 Feb., 1966], No. 5324/66. Heading F2F. A servo-assisted braking system for a motor vehicle comprises a means to detect movement of the vehicle in one direction, e.g. rearwardly, and means operable in response to detection of such movement by the detection means to operate the system automatically to apply the brake and means operable at will to render the operating means inoperative. The operable means may comprise a solenoid operated valve incorporated into a pipe 36, which valve, when the vehicle moves rearwardly, allows air at atmospheric pressure to act on a piston 20 of a vacuum suspended servomotor. The detection means may comprise a frictionally driven, electrical contact arm which abuts a stop when the vehicle is moving in a forward direction and which completes an electric circuit by abutting a stop and electrical contact assembly when the vehicle is moving rearwardly (Fig. 4, not shown). The means operable at will comprises an immobilizing switch which prevents actuation of the solenoid operated valve when the vehicle moves rearwardly, the switch being mounted on the hand-brake button or on the vehicle dashboard. The servomotor is connected to the vehicle engine inlet manifold (Fig. 1, not shown) there being a vacuum tent interposed therebetween. Hydraulic fluid from a master cylinder actuates a control piston 21 to seat or unseat atmospheric or vacuum valves 28, 29.