BRAKE SERVO-UNIT COMPRISING A FLOATING ELEMENT BEARING OFFSET VALVE SEATS

摘要

The invention concerns a pneumatic brake booster for a motor vehicle, wherein the movements of a control rod (38) are capable of determining the opening and closing movements of a so-called intake axial valve (52) interposed between a pressure source subjected to pressure (Pa) higher than the first pressure (P1) and a rear chamber (18) of the servo-unit, and at least a so-called compensating axial valve (50) interposed between a front chamber (16) and the rear chamber (18) to actuate a mobile partition (14) interposed between the front chamber (16) and the rear chamber (18). The invention is characterized in that it comprises a tubular element (76) whereof the axially offset transverse surfaces comprise first elements (82, 84) sealing the axial intake and compensation valves (50, 52) which the control rod (38) is capable of actuating via a spring retainer (49) bearing two springs (40, 122) of different stiffness.