Vehicle anti-skid braking systems.

摘要

In a vehicle anti-skid hydraulic braking system of the pump/re-apply type the pump plunger (10) is of differential outline and works in a stepped bore (13). An annular chamber (18) and a full pump chamber (19) are defined in the bore (13) on opposite sides of the head (11). The annular chamber (18) is pressurised by fluid at a pressure dependent on the difference in pressure between the master cylinder (29) and the brake (31), and the chamber (19) is subjected to the pressure in the annular chamber (18) in one direction and the pressure in the master cylinder (29) in the opposite direction. The system is therefore provided with a pump (10) which forces fluid back to the master cylinder (29) but with torque levels similar to a pump which acts against brake pressure. In motor cycle installations a unit comprising the modulator assembly (2) and pump (3) is utilised, the unit being sufficiently small to fit into and to be driven by an enlarged wheel hub.