Abstract: A vehicular hydraulic brake system wherein valve means are provided which in the release position of the brake and during normal braking actions establish communication between diagonally opposite wheel brakes and which preferably hydraulically connect the wheel brakes of the rear axle of the automotive vehicle with each other. In order to achieve a higher degree of operational safety a change-over valve which is controllable by the pressure prevailing in the pressure chamber of the hydraulic power booster is connected at each wheel brake of the rear axle. Each change-over valve connects diagonally opposite wheel brakes with each other in a first position and, upon pressurization, interrupts this communication and establishes a communication between two wheel brakes of one vehicle axle.

Abstract: In a hydraulic motor vehicle servo brake comprising a tandem master cylinder (11), a brake valve (17) is provided which upon actuation through the brake pedal (16) applies, in controlled manner, pressure medium supplied by a hydraulic pump (18) connected to an intake reservoir (27) to the first master piston (24) and to a brake circuit (III) directly, to provide there a controlled pressure. A wheel slip brake control system at an initial slip of one or more motor vehicle wheels, will reduce automatically the brake force on the motor vehicle wheels to a value just sufficient to turn the wheels. Two switch valves (21, 21') to which the controlled pressure is applied are normally closed and open upon a beginning slip of one or several motor vehicle wheels to apply the controlled pressure to the master cylinder (11) from where the pressure medium is passed by way of two check valves (23, 123) to the pressure chambers located behind the master pistons (24, 80).

Abstract: A vacuum-operated brake power booster, including a control valve comprising a control valve piston with valve seat actuated by the piston rod, a poppet valve with two valve seat faces and a valve seat at the longitudinally slidable control valve body. The movements of the poppet valve relative to the two valve seats are controlled by a transverse member embracing the neck of the poppet valve. The radially external end of the transverse member touches the stationary sealing ring in the release position of the brake. For the purpose of interaction of the poppet valve with the transverse member, the neck of the poppet valve is furnished with an annular groove at its radially external peripheral surface, the width of the annular groove being sized larger than the thickness of the transverse member which engages in that groove.

Abstract: An actuating device for a vehicle hydraulic brake system of the type having electromagnetically operated valves in the hydraulic circuits to each wheel brake for providing slip control wherein the device includes a master cylinder having a brake pedal force responsive hydraulic booster piston for actuating a master cylinder piston slidably mounted within a slidable positioning sleeve within the bore of the master cylinder. The positioning sleeve is adapted to be mechanically coupled to the booster piston in the brake actuation direction. A stationary projection on the interior end of the master cylinder protrudes into the positioning sleeve and cooperates with the sleeve and master cylinder piston to vary the master cylinder volume.

Abstract: This invention relates to a hydraulic brake system for automotive vehicle with a master cylinder (2) and with a hydraulic power booster (1) connected upstream of the master cylinder (2) and having a pressure chamber (4) in which an auxiliary pressure depending on the actuating force (F) may be modulated via a pedal-operable brake valve (7). Wheel brakes (51, 53) of a first brake circuit are connected at the pressure chamber (4), wheel brakes (50, 52) of a second brake circuit being connected at the master cylinder (2). The braking pressure active in the wheel brakes (50 through 53) is controllable by valve members (39, 54 through 59) controllable in dependence on the slip. In case of control, a hydraulic communication will be established between the pressure chamber (4) of a hydraulic power booster (1) and the master cylinder.

Abstract: A pressure-fluid-operable vehicle brake system is proposed, which is fed by an auxiliary energy supply system (3) and which comprises a master cylinder device (1), in which a booster piston (40) adapted to be acted upon by the auxiliary energy is slidable in a pressure fluid chamber (26). When the auxiliary energy supply system (3) is intact, the booster piston (40) comprises an effective area for the pressurization of a wheel brake cylinder which is larger than an effective area which results upon failure of the auxiliary energy supply system. Upon failure of the auxiliary energy supply system (3), the necessary deacceleration is achieved because of a smaller effective area at the booster piston (40) and at a greater displacement travel of the booster piston (40) and with less pedal force (F).

Abstract: A slip control hydraulic brake system for wheel brakes wherein a sliding booster piston and a second piston form a working chamber with hydraulic pressure that acts upon a wheel brake. The booster piston and the brake system housing form two annular chambers, the second annular housing chamber larger than the first, whereby upon actuating travel of the booster piston the first annular housing chamber increases in volume and the second annular housing chamber decreases in volume.

Abstract: The present invention relates to a dual-circuit hydraulic brake system with slip control, in particular for automotive vehicles, wherein wheel brakes (26, 27, 41, 42) are connected via electromagnetically actuatable multiple-position valves (38, 39, 88, 40, 24, 89) to brake circuits which are hydraulically isolated from one another, wherein the brake circuits are adapted to be pressurized by a tandem master cylinder (1), on the one hand, and are connectible to a dual-circuit pump aggregate (76, 77) adapted to be driven electromotively, on the other hand. Both outlets of the pump aggregate (76, 77) are connected to normally closed brake valves (43, 44) which are governed by the master cylinder pressure and separating valves (11, 12) which are adapted to be closed by the outlet pressure of the brake valves (43, 44) are inserted into the connections between the tandem master cylinder (1) and the wheel brakes (26, 27, 41, 42).

Abstract: In the braking system of a motor vehicle, a hydraulically or electromagnetically actuatable valve is inserted into the return line to control and monitor hydraulic brake slip control devices supplied with energy from an external source. This valve opens or closes the return passage of hydraulic fluid from pressure reducing valves of static brake circuits in dependence upon the dynamic pressure developing in the booster chamber of brake valve network or in the prechamber of the master cylinder upon application of the brake or upon start of the brake slip control. Pressure reduction in the static brake circuits for preventing a wheel lock-up will thereby be avoided, if in the event of a control action no dynamic pressure develops in the booster chamber or in the prechamber on account of a defect.

Abstract: A dual-circuit hydraulic brake system with slip control, in particular for automotive vehicles, in which there are provided several sensors sensing the rotational behavior of the wheels and several solenoid valves (39, 37, 40, 38 41, 42, 30, 31) which are controllable by slip monitoring electronics (32). The wheel brakes (33, 34, 35, 36) connected to the brake circuits may be pressurized by a tandem master cylinder (3), on the one hand, and by an auxiliary pressure source, on the other hand. The auxiliary pressure source consists of an electric-motor-driven pressure medium pump (20) and of an accumulator (21). Each working chamber of the tandem master cylinder (3) hydraulically communicates with a brake valve (16) which may generate a dynamic pressure which, upon the actuation of the brake, will be supplied to wheel brakes (33, 34, 35, 36) by a switching-over action of inlet valves (30, 31).

Abstract: To monitor and control hydraulic brake slip control devices supplied with energy from an external source and intended for use on motor vehicles equipped with several brake circuits, a check is kept on the fluid level in the reservoir holding the hydraulic fluid and on the pressure in the chambers supplied with the external energy. When the fluid level drops, which is detected by a reservoir level warning device, or when the pressure drops causing pressure warning switches to respond, the brake slip control will be only partially deactivated initially by halting the reduction in pressure in the static brake circuits and inhibiting the dynamic fluid flow into the static brake circuits. The dynamic brake circuit will continue to allow a controlled deceleration of the connected wheels. The partial deactivation will be initiated immediately or with a time delay or only if the error signals continue to be present beyond a predetermined period of time.

Abstract: The hydraulic brake system with slip control comprises a master cylinder piston for operating a wheel brake, in which hydraulic medium tapped from the wheel brake during slip control will be supplied to the wheel brake from an auxiliary pressure source via a master cylinder gasket acting as check valve. The operating stroke of the master cylinder piston is limited by pressurization of a positioning piston through which a master cylinder piston rod is passed in a sealed manner and which is guided axially displaceable in a sealed manner in a housing. In order to prevent an abrupt movement of the positioning piston upon pressurization the positioning piston is constructed as a stepped piston whose smaller diameter is sealed with respect to the housing and having a piston step which in combination with the seal between the smaller diameter portion of the positioning piston and the housing annular chamber with a volume which is dependent on the pedal travel.

Abstract: A hydraulic brake booster includes a booster piston axially slidable in a bore of a housing and delimiting therein a boosting compartment, and a brake pedal responsive operating element which partially extends into the boosting compartment to act as a plunger therein. A control valve has a valve body which is stationary relative to the housing and a valve member which is slidably received in the valve body and controls communication of a pressure chamber with sources of control fluid at reference pressure and at control pressure, the pressure in the boosting compartment being proportionate to the pressure in the pressure chamber.

Abstract: A master cylinder for hydraulically actuated brakes for automotive vehicles includes at least one master cylinder piston with a piston return spring anchored by a central clamping member and a valve body which is slidable relative to the master cylinder piston and which opens a compensating port in the master cylinder piston when the return spring is relieved. The valve body carries an elastic sealing element at its end face close to the compensating port. The outer diameter of the elastic sealing element is greater than the diameter of the compensating port. A pin shaped on the valve body extends through the sealing element and is adapted to plunge into the compensating port on approach of the valve body to the piston end surface which surrounds the compensating port, thus preventing the sealing element from penetrating into the compensating port.

Abstract: A control arrangement for use in a hydraulic braking system equipped with an antiskid control device and an auxiliary energy source and including a master cylinder device which is operated in dependence on the travel of a brake pedal, includes normally open separating valves in braking conduits to the wheel brake actuating cylinders, which close during antiskid control operation, provided that auxiliary energy is available. An auxiliary supply conduit supplies the auxiliary energy to the wheel brake actuating cylinders so that the latter can be operated in a dynamic manner.

Abstract: In an auxiliary power assisted master cylinder arrangement for a vehicle brake system to generate a controlled brake pressure in associated wheel brake cylinders, there is provided a brake valve with a preceding servo travel simulator to effect a control of the wheel brake cylinders of a vehicle. In one construction of the arrangement, there is interposed between two master cylinder units a pedal-operable device including mechanical cross links connecting with the master cylinder units as well as another cross link connecting with the brake valve. The brake valve is movable into engagement with the servo travel simulator, while the pedal-operable device, under normal braking conditions, is acted upon by the controlled pressure from an auxiliary power source in opposition to the pedal pressure and includes a lock providing for interlocking of all mechanical links in the event of a failure of auxiliary power.

Abstract: In vacuum brake boosters for motor vehicles, the vacuum casing is conventionally made of sheet steel. The vacuum casing is subjected to mechanical and pneumatic forces which have to be absorbed by the casing components. This makes it necessary to construct the casing components so they are strong enough to take these forces. The result of such construction is, however, high costs and high weight. To eliminate these disadvantages, the invention provides a brake booster wherein the vacuum casing includes a pipe therein extending in approximately coaxial of the longitudinal axis of the vacuum casing and connected to the transverse end walls of the vacuum casing, the pipe enclosing the master cylinder push rod, and the movable wall of the brake booster is sealed relative to the pipe and slidable thereon.

Abstract: Hydraulic brake systems are known which comprise antiskid control valves and a pressure fluid source where pressure fluid is fed via a valve device and an antiskid control valve to a wheel brake cylinder. The pressure fluid source includes two jointly driven pumps. The disadvantage of such a system is the constant presence of a high pump output although this high output is only rarely required. Therefore, according to the present invention, an energy saving is realized by having the suction connection of a first of two jointly driven pumps connected to a pressure fluid reservoir and the suction connection of a second of two jointly driven pumps connected to the pressure fluid outlet of an antiskid control valve.

Abstract: A hydraulic power booster arrangement includes a brake valve which is arranged substantially in parallel to a booster piston and which is operative for controlling the connection from a pressure chamber to a auxiliary pressure source or to an unpressurized return reservoir. To control the movement of the brake valve, there is provided a multipart lever actuation mechanism including a support lever and at least one control lever which are pivotally connected to one another intermediate their respective ends. One end of the support lever is pivotally mounted on a retaining member which is rigidly connectible to the power booster housing. The housing is provided with a mounting hole through which the lever actuation mechanism is adapted to be inserted into the pressure chamber and which is adapted to be closed by the retaining member.

Abstract: An antiskid control arrangement of a hydraulic vehicle braking system includes a master cylinder device and a throttling valve device arranged between the master cylinder device and the brake pedal. The throttling valve device is incorporated in a circulating circuit which includes a hydraulic pump operated exclusively during antiskid control operation. During normal braking operation without antiskid control action, the braking system operates in a static manner. During antiskid control braking operation, the drive of the hydraulic pump is energized while the throttling valve device remains closed until the dynamic pressure generated by the hydraulic pump has risen to the level to the static pressure then prevailing in the working compartments of the master cylinder device. Thereafter, the throttling valve device opens to relieve excess pressure.