Abstract: A piston for the variable delimitation of a pressure chamber in a housing of a hydraulic cylinder, in particular a clutch master cylinder for motor vehicles, has a main section on which a running surface is provided for a sealing element on the housing side. The sealing element seals a pressure chamber in an operating position of the piston. The piston also has an after-running device, which, in a normal position of the piston, connects the pressure chamber to an after-running area. The after-running device is made separately from the main section and is connected without play to the main section to form the piston. As a result, a piston that is easy to manufacture is created and which, with reference to the after-running device, has an improved functionality compared with prior art.

Abstract: A piston for the variable delimitation of a pressure chamber in a housing of a hydraulic cylinder, in particular a clutch master cylinder for motor vehicles, has a main section on which a running surface is provided for a sealing element on the housing side. The sealing element seals a pressure chamber in an operating position of the piston. The piston also has an after-running device, which, in a normal position of the piston, connects the pressure chamber to an after-running area. The after-running device is made separately from the main section and is connected without play to the main section to form the piston. As a result, a piston that is easy to manufacture is created and which, with reference to the after-running device, has an improved functionality compared with prior art.

Abstract: A method and a device for the hydraulic actuation of a clutch operatively connected to a clutch receiver cylinder (6), especially for automobiles, are disclosed, in which, in a servo circuit (S), a servo pressure is generated, whichserves for the hydraulic governing of a clutch transmitter cylinder (2), in order to generate in a pressure circuit (D) a working pressure, which is applied to the clutch receiver cylinder (6), oris applied directly to the clutch receiver cylinder (6), in order to create there a force required for disengaging the clutch. According to the invention, the servo pressure for disengaging and engaging the clutch is adjusted in defined manner in the servo circuit (S), for which purpose the servo circuit (S) comprises a proportional valve (8, 8'). As a result, with technical equipment at low cost, an automated actuation with improved response and operational behaviour of the clutch is made possible.

Abstract: In order to reduce the weight and manufacturing cost of a piston for a hydraulic actuating cylinder, the piston, the piston rod and the external reinforcement cap are combined to form a unitary integral part. The unitary part is advantageously a single extrusion product. The piston is shaped so as to be able both to slide along the length of the inner cylinder wall, and to tilt upon deflection or lateral displacement of the piston rod in the bore of the cylinder, while still maintaining its hydraulic seal.

Abstract: A master cylinder for use on a hydraulically actuated clutch or brake system of a motor vehicle, or for the like uses. The master cylinder comprises a cylindrical housing, and a piston which is axially displaceable along the housing, a piston rod in the housing. The piston rod is connected with the piston to be movable together free of play, but they are swingable with respect to each other, whereby the piston rod may swing with respect to the piston in the housing. The connection between the piston and the piston rod comprises a generally ball shaped head on the piston rod, which is held between partial shells in the housing which are shaped to partially surround and form lock to the piston rod head. The piston has a neck with receiving grooves in it. The partial shells have projections which engage in the grooves in the neck. A tubular piston-shaft sleeve in the housing is axially shiftable in the housing and is fastened to the piston.

Abstract: A hydraulic cylinder, preferably for use as a master or slave brake cylinder or in a hydraulic clutch system, maintains in a simple and inexpensive manner through the use of eccentric bushings the stroke length of the piston rod. The distance between the attachment lug and the attachment point determines the stroke length and is varied by adjusting the narrow tolerance of each bushing.

Abstract: A check valve in an automotive braking system between the master cylinder and a wheel cylinder includes a screw or a piston mounted in the check-valve housing for overriding or opening the valve prior to a charging or filling operation to facilitate an evacuation of air from the system. A flow-regulating assembly in the valve includes an annular sealing disk biased by a restoring spring into a fluid-tight contact with an annular valve seat. Another restoring spring mounted in the housing in opposition to the first spring biases a spherical plug into a fluid-tight contact with an inner rim of the disk, this disk being mounted in a cup-shaped extension of a hollow shaft. In one embodiment the shaft extends from the flow-regulating assembly to the override screw; upon an inward shift the screw engages the free end of the shaft and thereby pivots the same and the sealing disk about a point on the valve seat.