Abstract: A device for controlling the pressure in an auxiliary-pressure supply system of a hydraulic brake unit for automotive vehicles, which device comprises a diaphragm-type or bladder-type accumulator equipped with a hydraulic and electric switching arrangement by way of which the hydraulic pressure in the pressure accumulator can be reduced to a predetermined value after the engine of the vehicle has been turned off. An electromagnetic multidirectional control valve is used to divert hydraulic fluid back to a reservoir through a pressure-limiting valve connected downstream thereof. After the engine of the vehicle has been turned off, the multidirectional control valve remains open until the accumulator pressure has decreased to at least the gas inflation pressure of the accumulator. The invention reduces permeation of gas molecules through the diaphragm of the accumulator into the hydraulic fluid and thus effects a longer useful life of the pressure accumulator.

Abstract: An anti-lock hydraulic brake system for vehicles incorporating a master cylinder (21) and wheel brakes, (30, 31) connected to the master cylinder (21) through connecting lines (32, 34), as well as an anti-lock apparatus having sensors for the associated wheel brakes (30, 31) by which, in the event of excessive deceleration of a vehicle wheel, the wheel brake will be disconnected from the master cylinder (21) by a valve (11) and will be connected to a relieving device. The relieving device is composed of a slave cylinder (1), whose piston (2) is in operative engagement with a movable wall of an actuating device operating with vacuum, which movable wall is displaceable to assume a control position in opposition to the force of a resilient element, for example a steel spring, the piston chamber (44) in front of the piston (2) being connected via a by-pass line (35) which contains a valve (23) with the brake line (32, 34) communicating with the intermdeiate chamber (45) of a separating valve ( 11).

Abstract: A brake system for automotive vehicles is equipped with devices for the electric control of the brake force distribution and/or for the control of slip. The front wheels are connected to a pedal-actuated braking-pressure generator (1). In contrast thereto, the rear wheels (HR, HL) are acted upon with braking pressure by virtue of a braking pressure generator unit (5) which is composed of a vacuum servo unit (6) and a master cylinder (7) and which is actuated by a multidirectional control valve (4), such as a three-way/three-position rotary spool valve. The switch position of the valve (4) is responsive to the electric output signals of an electronic combining circuit (17, 17') which is, by way of wheel sensors, furnished with information about the rotational behavior of the wheels and the output of which circuit is electrically connected to the drive (19) of the three-way/three-position rotary spool valve (4).

Abstract: A brake system for automotive vehicles comprises a dual-circuit hydraulic braking pressure generator (3) which is substantially composed of a power brake booster (4) and a master cylinder (5). Each one front wheel (VR or VL) is connected to the two brake circuits (1, 2) directly, while a rear wheel (HL or HR) is connected thereto by way of braking pressure modulator (6, 7). Further, for the purpose of pressure reduction, there is provided a pressure fluid line containing a separating valve (18) from the rear-wheel brakes (14, 15) to a pressure supply reservior (11). The auxiliary energy supply system comprises a pressure fluid pump (8), the pressure side of which can be "shot-circuited" with the suction side by way of a value (19) for reducing the auxiliary energy transmitted onto the braking pressure generator and thus for decreasing the braking pressure at the front-wheel brakes (12, 13).

Abstract: A slip-controlled brake system, wherein the brake pedal effort is transmitted power-assisted to a master cylinder (10) to the wheel cylinders through several hydraulic fluid paths which allow shut off independently of one another. The behavior of rotation of the wheels and the vehicle speed are measured by sensors (S1 to S4), with the signals logically linked and control signals generated from them for electromagnetically actuatable directional control valves (15, 16, 17). In the event of a control action, the power assisted pedal effort (F) directed on the master cylinder (10) is temporarily compensated by an external power action in an opposite direction whereby the pressure increase in the master cylinder (10) is slowed down or decreased.

Abstract: A device for determining the rotational speed of a rotating component, in particular of a brake disc (1) of an automotive vehicle brake, the brake disc (1) containing recesses (2) shaped at preferably regular distances and lying opposite to a probe. A contact element (5) is provided as the probe which is adapted to move into abutment on the brake disc (1) and which, when overriding each recess (2), will interrupt an electric circuit comprising an evaluation circuit.

Abstract: A device for determining or checking the condition, state, or other parameters of a pressure fluid contained in a hydraulic system substantially comprises a body which may be screwed into the wall of a chamber or of a line of the hydraulic system, which at its front face having contact with the pressure fluid has a measuring or testing device, and which at its part accessible from the outside has an electric contact which is in communication with the measuring and testing device via a line passed through a central bore.

Abstract: The vehicle brake system includes electronic control logic and an electrically controllable pressure modulator for the brake actuating device of each wheel responsive to the output of the control logic. A brake-signal transmitter transmits to the control logic the value of the desired vehicle deceleration and a deceleration responsive device mounted on the vehicle transmits to the control logic the value of the actual vehicle deceleration. The control logic adjusts the brake pressure supplied by each pressure modulator by a signal dependent upon the difference between the desired value and actual value of the vehicle deceleration. The brake system disclosed is an all digital system and is not temperature sensitive. The brake system also includes antiskid capabilities.