Abstract: A vacuum brake power booster and a process is disclosed in which a precise adjustment of the power boost startup characteristic is achieved. The adjustment is carried out as a final step in the manufacture of the booster adjusting the distance between the valve piston and an elastic reaction distance. During adjustment, the vacuum brake power booster has a vacuum applied. A pre-established input force is exerted on the piston rod while simultaneously measuring the output force exerted by the push rod, and the axial length of the valve piston is modified until the measured output force is within a pre-established range. The adjustment is carried out by modifying the length of a two piece valve piston or by temporarily extending a rod within the valve piston until a correct output force is reached and thereafter removing the rod and inserting a transmission pin of a length determined by the extent of travel of the rod at the point at which the desired output force was attained.

Abstract: An automotive vehicle anti-lock brake unit reduces operator detectable pedal pulsations and vacuum requirements found in prior systems wherein the movable wall (7) of the vacuum brake power booster (1) is movable independently of the input member (4) and that a hydraulic chamber (50) being in active connection with the input member (4) is provided whose link (90) with a pressureless hydraulic fluid reservoir (11) allows to be shut off.

Abstract: Hydraulic brake systems are known wherein, for the purpose of brake control, a counterforce is built up in the booster (60) for actuation of the master brake cylinder which results in unloading the master brake cylinder. What is disadvantageous in the known system is that this counterforce also resets the pedal (pedal piston 3) so that vehement pedal movements will result from the control action. Therefore, our present invention suggests to interpose a transmission device (3, 4, 5, 6, 7) between the pedal and the actuator (booster) enabling to decouple actuator and pedal.

Abstract: A vacuum brake power booster, in particular for motor vehicles, which includes a poppet valve (12) sealing two valve seats (18, 19) and which is axially deformable within the area of a rolling fold (15) also includes an annular part which is either mounted on the outside of the rolling fold (15) in a form-fit manner or arranged inside the elastic material (24) of the poppet valve (12). This annular part prevents the rolling fold (15) from being blown up outwardly due to the pressure differential prevailing between its two sides so that it will be possible to reduce the return force and thus also the response force.

Abstract: A valve arrangement has a housing in which are arranged an electromagnetically actuatable pilot valve controlling a differential pressure and a main valve actuatable by the differential pressure, the closure member of the main valve permitting a connection to be established between an outlet port and, alternatively, a first or a second inlet port. In order to keep the overall length of the valve arrangement as small as possible, the present invention provides a joint axis (29) of the pilot valve (5) and of the electromagnet (6) actuating the pilot valve (5) which is perpendicular to the axis (30) of the main valve (7) in a plane that is radially offset relative to the axis (30). In the inactive position, both compartments (23, 24) are exposed to the higher pneumatic pressure.

Abstract: A metal cup accommodating a reaction disc and the end of a push rod is fixed with respect to a control valve housing of a vacuum brake power booster. The manner of fixation is of simple design, allowing the parts to be manufactured at low cost and offering ease of mounting. According to the invention a metal cup is supported in axial direction at the front side of the control valve housing and is retained by a retaining clip in a positive locking fit with the control valve housing.

Abstract: In a slip-controlled automotive vehicle brake system, to reduce the number of the valves used, while simplifying the system construction, the wheel brake cylinders are connected to relief chambers (123, 133, 124, 134) of compensating cylinders (120, 130), the connection between the master-brake-cylinder pressure chambers (80, 90) and the relief chambers (123, 124, 133, 134) being closable during slip control.