Abstract: In an antilocking ABS and propulsion ASR control system for a road vehicle, there is a brake pressure regulating member used for both antilocking ABS and for propulsion ASR control in which a hydraulic cylinder having a piston driven under valve controls defines an ABS control space, increasing when a drive pressure space of the cylinder is subjected to pressure, and an ASR outlet pressure space, decreasing when the drive pressure space of the hydraulic cylinder is subjected to pressure; and wherein, in normal braking, not subjected to ABS or ASR control, both spaces are connected to the brake circuit of the driven vehicle wheels. The control system is activated as a result of the valve control connection of an auxiliary pressure source to the drive pressure space of the hydraulic cylinder.

Abstract: A brake system with hydraulic power assistance having a control valve which connects a fluid pressure to a brake booster for normal braking and disables the brake booster and connects fluid pressure to a counterpiston which moves an output piston enlarging the output pressure space and thereby lowering the brake pressure during antilock control. The source of pressure may be a brake pedal proportional booster pressure derived from an auxiliary pressure source or may be the auxiliary pressure source itself.

Abstract: A brake pressure control unit operable by a hydraulic brake power booster and functionally corresponding to a tandem master cylinder for two statically pressurizable brake circuits has two casing bores spaced laterally apart. In one of the bores, the primary output pressure space bounded by the primary piston and floating piston is accommodated, and in the second bore, a piston which is also a floating piston, bounds the secondary output pressure space by a piston flange. The floating piston bounding the primary output pressure space on one side has the effect of building up, in the end control pressure spaces of the first and second bores, the control pressure acting on the second floating piston. This pressure leads to a displacement of the second floating piston in the sense of a pressure build-up in the secondary pressure space. The second floating piston is connected to a double-acting hydraulic cylinder, which is likewise accommodated in the second casing bore.

Abstract: A modulator for a vehicle with a power-assisted hydraulic multiple-circuit brake system, providing an output pressure to a static brake circuit that is proportional to the sum of the forces affecting a pressure modulator piston. These forces include a pedal pressure from the brake-pressure control device to a first driving pressure space of the modulator and booster pressure from the pressure of a proportional control valve to a second driving pressure space of the modulator, which shifts the modulator piston to decrease the output pressure space. Forces produced by auxiliary pressure in a counterpressure space shifts the modulator piston to enlarge the output pressure space. A control valve arrangement disconnects the second driving pressure space from the booster pressure and instead relieves pressure of the second driving pressure space in pressure-reduction phases of the antilock control.

Abstract: A hydraulic brake-power booster unit is provided for a vehicle having a dual-circuit brake system and an antilock system operating according to the drain principle. When the brake system is intact, the booster unit provides dynamic pressure to one of the two brake circuits and static pressure admission to the other. The pressure to the static brake circuit takes place by the separate-power-assisted shifting of an emergency piston. On one side, the emergency piston delimits an output pressure space to which the brake circuit that can be statically acted upon by pressure is connected. This brake circuit also remains operable in the case of a breakdown of the hydraulic power source only by the operation of the pedal and the resulting possible shifting of the emergency piston. A path transducer generates an electrical signal proportional to the position of the emergency piston.

Abstract: A hydraulically power-assisted dual circuit brake system for road vehicles combined with an anti-locking brake system has a stepped tandem master cylinder and a primary piston. The primary piston includes a ring piston which is displaceable in a larger cylinder step and a plunger which is displaceable in said ring piston. A pre-pressure acting on the control area of the plunger of the primary piston is built up by pedal actuation of a further plunger. This pre-pressure operates as a reference pressure and is also coupled into a proportional control valve. The proportional control valve provides a control output pressure which is taken from the auxiliary pressure source and is higher. The control output pressure is used to impinge the ring piston and thereby move the plunger of the primary piston. With use of the ABS control, at least a secondary brake circuit, in a special design a primary brake circuit as well, is switched over from static to dynamic operation.

Abstract: A recirculating pumping device for an anti-locking two-circuit motor vehicle brake system, with the pumping device including one pump piston provided for each brake circuit. The pumping device recirculates brake fluid released from the wheel brake cylinder or cylinders to a master brake cylinder during an anti-locking regulating or control process. The pumping device includes piston pumps, with one pump being provided for each braking circuit of the braking system. The piston pumps are constructed as free piston pumps having working chambers connectable periodically to a pressure source provided on the vehicle through a valve. The valve is switchable at a predetermined switching frequency or may be vented to the tank of the pressure source. The pistons are preferably constructed as stepped pistons, so that the recirculating pumping device may be adapted to the pressure level of a pressure source already available on the vehicle by an appropriate selection of a ratio between the piston surfaces of the pistons.

Abstract: A brake valve useable in conjunction with a vehicle braking system monitored by an anti-locking device and operable by a brake pedal through a trailing spring sometimes also called a simulating spring. The brake valve is provided with a control slide valve longitudinally displaceable by the trailing spring. The slide valve regulates a metered feed of the pressure medium conducted from a pressure source to the wheel brake cylinders. The pressure medium is relieveable at the wheel brake cylinders by anti-lock valves. The slide valve includes two control slide valves of which is associated with a pressure reservoir. One control slide valve cooperates with an emergency piston providing free through-flow during normal operation of the braking system. The emergency piston, upon a failure of the pressure medium source, after an emptying of the pressure reservoirs, is operable mechanically by the brake pedal after a spring-loaded ball valve has been closed at the emergency piston.

Abstract: A brake valve useable in conjunction with a vehicle braking system is monitored by an anti-locking device and operable by a brake pedal through a trailing or simulating spring. The brake valve is provided with a control slide valve for regulating a metered feed of the pressure medium conducted from a pressure source to the wheel brake cylinders of the braking system. The pressure medium is furthermore relievable at the wheel brake cylinders by anti-lock valves. The control slide valve cooperates with at least two emergency pistons freely traversible during normal operation of the braking system. Each of these emergency pistons are mechanically operable from the brake pedal in case of failure of the energy supply or of a brake circuit after a valve associated with the respective pistons has been closed.

Abstract: A brake force servo-device, especially for motor vehicles, with a control piston, selectively actuatable preferably by a brake pedal, which cooperates with a connecting valve connected with a pressure medium source and which is operable to displace a flow medium out of its cylinder space for the actuation of the connecting valve; a working piston is thereby actuated by the pressure controlled by the connecting valve, whereby the control piston is constructed as one-piece control piston having an annular step and is sealed off, on the one hand, within the area of its entry into the brake force servo-housing and, on the other, in proximity of its end face which projects into a working pressure space; the control piston thereby abuts at the working piston present in the working pressure space while the connecting valve is actuated by the flow medium displaced by the annular-shaped step of the control piston out of the annular space which is formed between its two bearing places.

Abstract: A brake valve for a control piston actuatable at will, which shifts a double valve by way of a spring that closes off a flow connection between a working pressure space and a supply reservoir for pressureless brake medium and which during the further movement opens up the inlet between a pressure storage device containing a brake medium under pressure and the working pressure space. A closure member constructed spherically within its sealing area, which together with a stem mounted thereon forms a valve body, is tied to a valve piston by way of this stem in such a manner that the valve member is connected in its longitudinal direction with the valve piston but is radially freely movable with respect thereto to thereby assure centering of the valve member with respect to the valve seat.

Abstract: A servo brake system with at least two circuits, equipped with a tandem master cylinder, in which two working pistons are arranged coaxially one behind the other; a transmission shifting device thereby automatically shifts in case of failure of the servo installation to a larger pedal travel with a mechanically applied brake pressure that is reduced within permissive limits; the working piston of the actuating side thereby includes a bore coaxial to the other working piston, in which a plunger piston is guided which is actuatable by the input piston.

Abstract: A shifting apparatus for the indirect changing of the mechanical brake pedal transmission ratio in case of failure of the servo-assist of a motor vehicle brake force booster system, in which the shifting apparatus can be installed at any suitable place of the motor vehicle as well as in the lines extending between the master brake cylinder and the wheel cylinders; the control piston which is arranged in the shifting apparatus is actuated by the medium put under pressure by the pump of the servo-installation, and undertakes the shifting control of the pressure medium coming from the master cylinder to attain a shifting action in case of failure of the servo-installation.

Abstract: A multi-circuit brake installation for vehicles, in which two transmitter brake pistons which possess differently large effective brake pressure piston areas and which are hydraulically connected with each other, operate within a master brake cylinder actuatable at will by means of a servo-assist; these two transmitter brake pistons are connected into a respective brake circuit and are provided with corresponding means for limiting the relative movement with respect to one another, whereby control means are provided independent of the brake circuit for disengaging the hydraulic drive connection between the two transmitter pistons, which are displaced positively into the disengaging position exclusively upon the occurrence of a critical value of the servo-assist.