Abstract: A tandem master brake cylinder for a hydraulic motor vehicle brake system, which is impinged upon by a pneumatic brake booster, including at least one piston which is displaceable in a housing and has a plurality of follow-up connections the follow-up connections allowing a hydraulic connection between the pressure chamber and a pressureless follow-up chamber at the start of a braking operation. At least some of the follow-up connections are formed as transverse bores through a wall of at least one piston and are arranged at a same distance relative to the piston edge in a main plane, wherein the overtravel thereof by the sealing collar defines a closure path of the piston. In order to allow a smooth, quiet and yet sufficiently reliable braking initiation, the follow-up connections are arranged in a distributed manner on at least three planes, the planes being arranged at a distance to one another and in parallel to the piston edge.

Abstract: A tandem master brake cylinder for a hydraulic motor vehicle brake system, which is impinged upon by a pneumatic brake booster, including at least one piston which is displaceable in a housing and has a plurality of follow-up connections the follow-up connections allowing a hydraulic connection between the pressure chamber and a pressureless follow-up chamber at the start of a braking operation. At least some of the follow-up connections are formed as transverse bores through a wall of at least one piston and are arranged at a same distance relative to the piston edge in a main plane, wherein the overtravel thereof by the sealing collar defines a closure path of the piston. In order to allow a smooth, quiet and yet sufficiently reliable braking initiation, the follow-up connections are arranged in a distributed manner on at least three planes, the planes being arranged at a distance to one another and in parallel to the piston edge.

Abstract: In order to improve the deformation behavior of a vacuum brake booster provided with force transmission pins that are used to transmit forces onto a body splashboard of a motor vehicle, the invention discloses that the force transmission pins are made up of two sections having different strength. To achieve a sufficiently low strength when a fastening screw is used for a first section, the first section is embodied as a hollow body, and the fastening screw extends only over the length of a second section of the pin. Because the first section is configured as a hollow body, the screw arranged in the second section can be actuated through the first section.

Abstract: The deformation behavior of a transmission pin transmitting forces to the body fender of a motor vehicle and being found in the vacuum brake booster, is improved by equipping the transmission pins with predetermined breaking points or segments with smaller diameters.

Abstract: To prevent a rolling diaphragm (13), which forms the movable wall (4) of a vacuum brake booster along with a metallic diaphragm disk (12), from becoming detached from an annular groove (52) accommodating a radially inner bead (32) of the rolling diaphragm (13), the rolling diaphragm is connected to the edge of the bead (32) located away from the (first) diaphragm disk (12). By connecting the rolling diaphragm (13) to the edge of the bead (32) located away from the (first) diaphragm disk (12), a pneumatic space (27) is defined by the rolling diaphragm (13) and the (first) diaphragm disk (12). Pressure occurring in the vacuum chamber(s) (28, 30) can be admitted to the pneumatic space (27).

Abstract: An actuating unit for a hydraulic brake system for automotive vehicles includes a vacuum brake power booster and a master brake cylinder. To transmit the reaction forces, developing during actuation in the master brake cylinder, to a vehicle body wall which carries the actuating unit, a centrally positioned force-transmitting element is provided, which is arranged between the master brake cylinder and the vehicle body wall in terms of effect. The force-transmitting element is formed of a continuous bolt which extends in an axial direction through the control housing of the vacuum brake power booster.

Abstract: To infinitely variably adjust the distance between a reaction disc and an interacting second part of a bipartite valve piston in a completely assembled vacuum brake power booster, which is already mounted to the automotive vehicle, a tubular sleeve is provided, arranged coaxially to a piston rod that actuates the valve piston, and is in engagement with a first part of the valve piston, connected with the second part by a threaded union, to apply a torque to the first piston part. For this purpose, the sleeve has at its end projecting from the control housing with an extension permitting rotation of the sleeve.

Abstract: In order to be able to adjust the distance between a reaction disc and a second part of a a two-part valve piston interacting with the former in a completely assembled vacuum brake power booster, a tubular sleeve is provided according to the invention which is disposed coaxially with a piston rod actuating the valve piston, which is axially slidable and which is engageable with a first part of said valve piston being coupled to the second part by means of a threaded union in order to apply a torque to the first piston part.

Abstract: A construction and fabrication process for a two piece vacuum brake power booster housing is described which eliminates the surface tensions which are caused by forming during assembly to prevent damage to a protective surface finish. Localized radially weakened zones are each formed by two opposing tongues created by circumferential and axial slots which tongues in the assembled condition of the housing engage behind an outwardly and reversely formed rim (3) of the other housing half (1).

Abstract: A vacuum brake power booster with a connecting member (23) for the connecting nozzle (2) of the vacuum line and for the vacuum non-return valve (3). The connecting member is configured in the shape of a housing for a sensing device which detects the position of the diaphragm retainer (16) within the servo-cylinder (15). The sensing device consists of a scanning pin (22) which allows rotation of a gear (9) by means of a flexible toothed rack (6). The gear allows rotation of a tap (12) on an ohmic resistance. The different voltage values generated in this manner indicated the position of the diaphragm retainer within the servo-cylinder. By an appropriate selection of components, by their configuration, by their mutual adaptation, and by the appropriate assembly of these components into a compact overall assembly unit, the contour of a conventional vacuum brake power booster is not exceeded. The mounting space requirements of the booster are thus reduced. The booster is universally applicable.

Abstract: A vacuum brake booster in which the guiding sleeve (14) for the push rod (29) has an annular ring which defines a cylindrical guiding surface (22) and is guided, in axial movements of the guiding sleeve, by a guide bore in the housing (10) of the control valve.