GB484129A - Improvements in and relating to hydraulic brakes - Google Patents

Abstract

484,129. Hydraulic brakes. WEIHE, H. K. Dec. 7, 1936, No. 33579. Convention date, Dec. 5, 1935. [Class 103 (i)] A hydraulic brake system for vehicles forms a closed circuit and a pump additional to the master cylinder is provided and is adapted to be operated by the brake pedal, clutch lever or other means so as to circulate the liquid intermittently and thus remove air and maintain the system filled with liquid. In Fig. 1, the pipe system 14 in which brake cylinders 15 .. 18 are interposed is connected at its ends respectively to the master cylinder 1 and to a circulating pump 6. The pump has a delivery valve 12 and an inlet valve 11 in a passage 51 leading to a reservoir 5. The pump piston 7 has a flexible connection 8 to the clutch and brake pedals 9, 4, and when either of these is depressed, the piston 7 draws from the reservoir 5 liquid which on the return movement of the pedal is forced by a spring 22 through valve 12, pipe 14 and the cylinders 15 .. 18 to the master cylinder 1 where it presses back the piston 2 and pedal 4 against the action of a spring 23 so as to uncover a port 20 through which it returns to the reservoir 5. In a modification, the reservoir and pump form a unit separate from the master cylinder and are arranged above that cylinder, for instance, on the dashboard; the reservoir forms an annular chamber around the vertical pump cylinder and the port corresponding to the port 20 is normally uncovered by the master piston and has a pipe connection, with a non-return valve, to the reservoir. In order that the brake cylinder volume may be as small as possible, a filling member 30 may be provided and is mounted on pins 26 extending from the pistons, these pins also carrying the cup-washers 28.