Abstract: A dual-circuit brake system including a diagonal division is provided by the invention. The brakes of the driven wheels, on the one hand, through inlet valves are in communication with the brake pressure generator and, on the other hand, through intake valves, are in direct communication with a pressure source. Moreover, communication is established with a reservoir through the outlet valves. For brake slip control purposes, pairs of inlet and outlet valves are actuated, while for traction slip control purposes, pairs of intake and outlet valves are actuated; during a traction slip control, the inlet valves and separator valves in bypass conduits leading to the inlet valves are closed. This circuit configuration involves the advantage that the intake and inlet valves may be provided with different diaphragms that are adjusted to the respective control mode.

Abstract: A hydraulically actuated wheel brake with a built-in control device comprising a brake piston including two pressure surfaces each of which defines a different one of two working chambers. The pressure fluid inlet is connected directly to one of the two working chambers and via a valve to the other of the two working chambers, the valve being actuatable upon attainment of a predetermined value of inlet pressure. The brake piston has a step in its outer periphery whose surface provides one of the two pressure surfaces. The piston is guided exclusively at its outer periphery in a cylindrical bore of a housing. Since only two parts are disposed concentrically in each other, there results ease of manufacture and a minor susceptibility to failure.

Abstract: A deceleration-sensitive braking pressure control unit having a ball valve freely movable in an inlet chamber of the housing of the unit. The ball opens or closes a channel for the passage of pressure fluid through a longitudinally slidable, pressurized stepped piston upon attainment of the change-over pressure with the vehicle loaded. The stepped piston is movable in the longitudinal bore of a pressurized annular piston which is supported slidably in the housing. In this arrangement, the annular piston is slidable in the housing to control the pressure fluid passage between its annular end face and the surface of the ball upon attainment of the change-over pressure, with the vehicle unloaded. Both the stepped piston, which contains the channel and the annular piston are comprised of varying effective surfaces acted upon by pressure fluid and are maintained in their initial positions in the housing by springs.

Abstract: Problems exist in known braking pressure control units for brake systems in which the rear wheels of a vehicle are assigned to different brake circuits. These problems include unequal outlet pressure to the two brake circuits due to manufacturing tolerances and that upon failure of one brake circuit the control function of the intact brake circuit still remains operative. According to the present invention these problems are eliminated by having two differential pistons bear against each other via a common spring device and to provide an arrangement by which upon failure of one brake circuit, the valve of the intact brake circuit will be moved into or kept in an open position.

Abstract: In a deceleration-sensitive braking pressure control device for a vehicular hydraulic brake system, the smaller active surface of a spring-loaded stepped piston faces an inlet chamber communicating with a brake pressure generator and the larger active surface of the stepped piston faces an outlet chamber which communicates with at least one wheel brake cylinder. The two chambers communicate with each other via a channel disposed coaxially in the stepped piston and a valve, the valve including a closure member movable in a deceleration-sensitive manner disposed in the inlet chamber and a valve seat at the adjacent end of the stepped piston. In the rest position of the stepped piston, a stop for the closure member guarantees a minimum distance between the closure member and the valve seat. This stop is provided at the adjacent end of an axially movable sleeve surrounding the adjacent end of the stepped piston.

Abstract: A pressure reducing control unit for brake system connected in the pressure connection between a master cylinder and a slave cylinder is known. The known arrangement is, however, of great overall length and is not safe against failure as well as being expensive with regard to production. According to the present invention the differential piston is constructed as a hollow cylinder having one end thereof slidably sealed in a housing bore and its other end slidable sealed on a plug fastened to the housing and projecting into the bore of the hollow cylinder. The pressure medium inlet is arranged in the plug. The differential piston on the end remote from the plug has a radial shoulder directed inwardly acting as a valve seat and separating an inlet chamber from an outlet chamber. The valve closing member is disposed at the end of the plug adjacent the shoulder.

Abstract: The control valve is disposed between the master cylinder and the wheel cylinder for controlling the brake pressure. The control valve comprises a differential piston which has a control force applied thereto and a valve which is controlled dependent on the movement of the differential piston. To achieve a very simple construction and a great variation of different control valve types employing largely identical elements, the control valve of the present invention includes a sleeve inserted into the housing bore and a screw-in cap to close the housing bore. Associated with the sleeve and the screw-in cap are spacer members to keep the sleeve in place. The differential piston is a stepped piston having an axial pressure medium channel with the end of this channel in the smaller diameter portion of the stepped piston cooperating with a valve closing member to provide the regulating valve.

Abstract: The control valve includes a pressure sensing piston disposed in a housing bore having a first active surface exposed to pressure of the front wheel brake circuit and a second active surface exposed to pressure of the rear wheel brake circuit, the second active surface being smaller than the first active surface. A stepped piston having an axial bore therein communicating with the rear wheel brake circuit is also disposed in the housing bore with the smaller diameter portion thereof being axially guided in a bore of the sensing piston. The end of the axial bore of the stepped piston in the bore of the sensing piston provide a valve seat and the sensing piston causes a valve closing member to effect a reduction of pressure in the rear wheel brake circuit when a given brake pressure is achieved.

Abstract: In a known motorcycle brake system, the pedal master cylinder acts on the front-and rear-wheel brakes, and the hand master cylinder acts only on the front-wheel brake. The brake force regulator's control behavior is influenced by the hand master cylinder. This known arrangement has functional disadvantages, since the rear-wheel brake is evacuated of fluid if the hand master cylinder alone is actuated. In addition, the regulator's change-over point is reached at a relatively high pressure. These disadvantages are eliminated by the regulator of the present invention by the provision of a valve adapted to closed independently of the position of the regulator's stepped piston. The stepped piston is not moved when the hand master cylinder alone is actuated. Also, the regulator of the present invention provides an improved deceleration of the motorcycle.

Abstract: Brake power control units for two-circuit brake systems are known in which a control piston and a locking piston are provided. The control piston reduces the brake pressure of the rear axle brake circuit in relation to the brake pressure of the front axle brake circuit and the locking piston acts on the control valve in the case of failure of the front axle brake circuit in such a way that the reducing effect for the rear axle brake pressure is neutralized. The two pistons of this known unit are arranged one behind the other which requires a great overall length for the control unit. According to the present invention, the overall length of the control unit is reduced by disposing the two pistons coaxial with respect to each other with the control piston enclosing the locking piston.

Abstract: In a known motorcycle brake system, the pedal master cylinder acts on the front-wheel brakes, and the hand master cylinder acts only on the front-wheel brake. The brake force regulator's control behavior is influenced by the hand master cylinder. Known regulators have operational disadvantages and require a relatively high hand master cylinder pressure for shifting the stepped piston back to its rest position. Also, this pressure must be transmitted by the valve seat. These disadvantages are eliminated by the brake force regulator of the present invention which includes a pressure piston actuated by the pressure of the hand master cylinder and is in permanent interaction with the end surface of the smaller step of the stepped piston.