GB1148836A - Improvements in or relating to hydraulic braking systems - Google Patents

Abstract

1,148,836. Master cylinders. SOC. ANON. ANDRE CITROEN. 16 Jan., 1967 [20 Jan., 1966], No. 2195/67. Heading F2F. In an hydraulic braking system a device is interposed between the master cylinder 5 and the brake circuits which comprises means 9 closing communication between the master cylinder and the braking circuits when the master cylinder pressure falls below a predetermined value, the remaining fluid in the braking circuits flowing back into a variable capacity space independent of the master cylinder and the same means ensuring that this fluid volume returns to the brake circuits on the next brake action before the re-opening of the communication between the master cylinder and the braking circuits. The device is connected through duct 4 with a fluid reservoir (not shown) and through intercommunicating ducts 10, 11 with the brake circuits. Operation.-When the brakes are applied the fluid pressure in master cylinder 5 is communicated via the duct 12 to act on a large piston 9 which moves a plunger piston 7 to the right against the loading of a spring 8. Fluid in the annular chamber surrounding the plunger piston 7 is forced into the brake circuits through duct 10 until the piston 9 has moved far enough to permit direct flow to the brake circuits through duct 11. On the return stroke of the master cylinder piston the brake fluid flows directly from the brake circuit via ducts 11, 12 to the master cylinder until the piston 9 closes this communication. The remaining fluid in the brake circuit passes via duct 10 to fill the variable capacity space, any excess fluid causing the piston 7 to move to the right to expel fluid from chamber 6 into the duct 4 leading to the oil reservoir. The device ensures the desired clearance between the interengaging members.