Anti-skid braking system for vehicles

Abstract

An anti-skid hydraulic braking system for a vehicle includes a modulator which in response to a skid signal at a skid point is operative to relieve the brake-applying pressure at a braked wheel by displacing fluid from the brake. The modulator includes a brake-application restrictor which is operative to control the rate at which the brake-applying pressure from a source can be re-applied to the brake at the cessation of the skid signal, and a valve assembly is incorporated to by-pass the re-application restrictor. The valve assembly comprising first and second valve members which are relatively movable between a spaced inoperative position in which unrestricted communication is provided between the source and the brake and an operative position in which the valve members are urged into engagement to render the restrictor effective. The first valve member is urged into engagement with the second valve member in response to the skid signal, and the second valve member is urged into engagement with the first valve member in response to any difference in fluid pressure acting across the restrictor. The restrictor will remain established until the difference in fluid pressure is reduced to a value at which the pressure from the source and the pressure applied to the brake are substantially equal. There is therefore no possibility of unrestricted communication between the source and the brake being established prematurely.

Dependencies are inferred from the claim text.