Abstract: The invention relates to a pneumatic brake-booster comprising a casing (10) inside which is a piston formed of a back tubular part (22) supporting a skirt (14) and which, with the aid of an unrolling membrane (12), defines a front chamber (16) connected permanently to a source of partial vacuum and a back chamber (18) connected selectively to the front chamber (16) or to the atmosphere via a valve (40) actuated by a control rod (34) capable of bearing, through the intermediary of the front face of a plunger (32), on a first face of a reaction disk (58) securely attached through a second face to a thrust rod (56). According to the invention, the piston (20) bears against the reaction disk (58) through a resilient annular front face (68, 68').

Abstract: A pneumatic brake booster (10) capable of operating without being actuated by a pedal (14), possesses at least one fixed part (36) and a control rod (12) with which the pedal cooperates (14). A sleeve (30) bears against the pedal (14) and partially surrounds the control rod (12), the control rod (12) possesses a shoulder (32) forming a stop cooperating with the sleeve (30) at rest and when the brake booster is actuated by the pedal (14), and the sleeve (30) is loaded by a spring (34) maintaining the pedal (14) at a given distance from the fixed part (36) of the brake booster (10) while the pedal (14) is not actuated.

Abstract: The vacuum servomotor comprises a main casing (12) divided sealingly on the inside into first and second chambers (10, 20) by a flexible membrane (9) bearing on a rigid disk (7) integral with an activating piston (3). The first chamber (10) is subjected to a low pressure, while the second chamber (20) is subjected either to this low pressure or to a higher pressure. An auxiliary casing (25) is integral with the rigid disk (7) and projects into the first chamber (10), an auxiliary piston (27) sealingly dividing the auxiliarly casing (25) on the inside into third and fourth chambers (30, 40), the third chamber (30) being closed by the rigid disk (7), the auxiliary piston (27) being mounted stationary relative to the main casing (12).

Abstract: The invention relates to a dual brake compensator for a motor vehicle, comprising two correcting valves, of which the inlets are intended to be connected separately to two independent brake-pressure sources and the outlets to two independent brake motors, each correcting valve being capable of controlling the values of the pressures at its inlet and at its outlet according to a predetermined relation and comprising a piston subjected to elastic return means by an inlet member. According to the invention, the dual corrector includes a mechanism for comparing the positions of the inlet members of each correcting valve.