Patent ID: 6076351
Filing Date: 2000-06-20
Classification: B60T

Abstract:
A boosted braking system for a motor vehicle having a master cylinder full of brake fluid and equipped with a main hydraulic piston which receives an actuating force composed of an input force and of a boost force both acting in an axial direction to cause an increase in pressure in said brake fluid and a pneumatic booster controlled by the application of said input force to a control rod integral with a plunger which controls the opening of a three-way valve to exert said actuating force on said main hydraulic piston, said booster including a rigid casing divided in leaktight fashion into at least a first chamber and a second chamber by means of at least one moving partition, said moving partition being acted upon by a difference in pressure between said first and second chambers resulting from the opening of said three-way valve, said moving partition driving a pneumatic piston which moves with respect to said casing, said moving partition carrying the three-way valve and contributing at least to transmitting said boost force, said main hydraulic piston of the master cylinder including a hollow moving cylinder receiving at least some of said boost force, a reaction piston which slides in leaktight fashion and axial direction in said hollow moving cylinder, said reaction piston receive at least the input force, said reaction piston being characterized by being integral with the plunger and delimiting within said moving cylinder a reaction chamber which communicates with an interior volume of said master cylinder through a pressure-regulating device inserted between said reaction chamber and said interior volume of the master cylinder and via which said reaction chamber communicates with said interior volume of said master cylinder.