초록 ▼

In a vehicle anti-skid hydraulic braking system of the pump/re-apply type the pump plunger is of differential outline and works in a stepped bore. An annular chamber and a full pump chamber are defined in the bore on opposite sides of the head of the piston. The annular chamber is pressurized by flu

In a vehicle anti-skid hydraulic braking system of the pump/re-apply type the pump plunger is of differential outline and works in a stepped bore. An annular chamber and a full pump chamber are defined in the bore on opposite sides of the head of the piston. The annular chamber is pressurized by fluid at a pressure dependent on the difference in pressure between the master cylinder and the brake, and the chamber is subjected to the pressure in the annular chamber in one direction and the pressure in the master cylinder in the opposite direction. The system is therefore provided with a pump which forces fluid back to the master cylinder but with torque levels similar to a pump which acts against brake pressure.

대표청구항 ▼

A vehicle anti-skid hydraulic braking system comprising a brake on a wheel, a master cylinder for supplying operating fluid to said brake to apply said brake, speed sensing means for sensing the speed of said wheel and for emitting skid signals, a modulator assembly for modulating the supply of oper

A vehicle anti-skid hydraulic braking system comprising a brake on a wheel, a master cylinder for supplying operating fluid to said brake to apply said brake, speed sensing means for sensing the speed of said wheel and for emitting skid signals, a modulator assembly for modulating the supply of operating fluid to said brake from said master cylinder, and an hydraulic pump for controlling re-application of said brake at the termination of a respective one of said skid signals, wherein said hydraulic pump comprises a stepped bore, at least one pump plunger of differential outline working in said stepped bore for movement in first and second opposite directions and having first and second opposite faces of which said first face is of a larger effective area and said second face is of a smaller effective area, means defining a full pump chamber between said stepped bore and said first face, means defining an annular chamber between said stepped bore and said second face, means for admitting fluid to said annular chamber to pressurise said annular chamber, said fluid admitted to said annular chamber being at a pressure dependent on the difference in pressure between said master cylinder and said brake, means for admitting fluid to said full pump chamber to subject said full pump chamber to the pressure in said annular chamber in a first direction of movement of said pump plunger, and means for admitting fluid to said annular chamber to pressure from said master cylinder in a second direction of movement of said pump plunger.