Anti-lock braking unit for a hydraulic braking system, particularly of a bicycle

Abstract

An anti-lock braking unit is provided which has a single actuating solenoid acting on a piston of an associated valve unit. The actuating solenoid moves the piston within a primary hydraulic chamber in fluid communication with a brake calliper. A movement of the piston closes a bypass passage formed within the valve unit, that connects a master cylinder to the brake calliper. By closing the bypass passage, the build-up of pressure acting on the calliper is stopped. Simultaneously, the movement of the piston opens an outflow passage within the valve unit, allowing a brake fluid to vent from the primary hydraulic chamber into an expansion chamber. The expansion chamber provides an increased volume for brake fluid contained between the valve unit and the brake calliper, thereby decreasing pressure of the brake fluid acting on the calliper.