Abstract: A hydraulic anti-locking brake unit is presented in which the brake line is shut off by an isolating valve (20) during a control action. For the reduction of the pressure, the outlet valve (7) is opened, so that the pump (14) delivers hydraulic fluid out of the wheel brake into the high-pressure accumulator (19). For a renewed pressure build up, the inlet valve (6) is opened, so that hydraulic fluid flow is directed out of the high-pressure accumulator (19) back to the wheel brake. In order to be able to utilize a high-pressure accumulator having a low receiving capacity, various valving arrangements are disclosed to direct excess flow from the pump either to the master cylinder or a low pressure accumulator.

Abstract: An anti-lock-controlled brake system with a auxiliary-force-assisted braking pressure generator accommodates a master cylinder in which at least one wheel brake is connected to a main pressure line, with an auxiliary hydraulic pressure pump connected to an auxiliary pressure line the system further includes wheel sensors and electronic circuits for detecting the rotational behavior of the wheels and for generating electric braking pressure control signals which, for the purpose of slip control, control the electromagnetically operable inlet valves and outlet valves inserted into the pressure medium lines. A pressure limiting valve is responsive to the pressure of the auxiliary pressure pump and to a pressure acting on the wheel brake to control the outlet pressure of the pump.

Abstract: A brake pressure control system with an anti-locking control is presented which is operated with hydraulic fluid including a master cylinder and a plurality of valves for the modulation of the hydraulic pressure in the wheel cylinders of the wheel brakes during a brake pressure control mode, and at least one motor-driven pump (48). An axially movable rotor (66) of the motor (14) is furnished with a thrust member (49) which shifts upon motor start up to actuate a control valve. The fluid connection between the master cylinder (37) and the wheel cylinder (43) is thereby interrupted almost instantaneously. Also, by actuating the valve, fluid flows through a flow limiting valve (59), delivered by the pump (48), into the wheel cylinder (43). A rapid pressure reduction is achieved in the wheel cylinder.

Abstract: A piston-type pressure accumulator for traction slip controlled brake systems, and a switching arrangement provided therewith. An accumulator piston (2) is hydraulically pressurized through a compression spring (1) and slidingly guided within a housing (4). At least one sealing element (27) is provided at the accumulator piston (2) which separates an accumulator chamber (21) from a spring chamber (24). The compression spring (1) is clamped between a first cap (3) directly contacting and surrounding the accumulator piston (2) and a second cap (5) straddling the housing (4) and the first cap (3), the first cap (3) performing a relative movement within the second cap (5) which is sensed by a control switch (7), charging of the accumulator chamber 21 is controlled by energization of a loading valve (8) and pump (9), in turn controlled by the control switch (7).

Abstract: In an anti-lock brake control system having a vacuum brake power booster and a tandem master cylinder, in which the brake pedal is controlled to be positioned forwardly of the initial return position during the anti-lock control mode. This is achieved by variation of the rate of delivery of an auxiliary pump as by switching the pump motor on and off by a switch actuated by the diaphragm of the power booster to provide a signal of the pedal position at the start of an anti-lock control phase. Various switching arrangements described include a Bowden-cable pulled by the diaphragm, a mechanical or an optical switch actuated by the rolling lip of the diaphragm, or an approach switch detecting the approach of the diaphragm and cam-assembly. The core (53) of the Bowden cable (54) is connected with the diaphragm plate (52) of the vacuum brake power booster. The core (53) moves the trigger cam (64). The switch (18) is actuated by the movement of the trigger cam (64).

Abstract: A travel sensor for measuring mechanical quantities of motion, in particular for determining the brake pedal position, comprising a transmission unit axially slidable in a housing and comprising a measuring apparatus for generating an electric signal representative of the travel of the transmission unit. The transmission unit is formed of two mechanical transmissions elements (12, 13 and 3, 6, respectively) corresponding with each other and effecting a reduction of the introduced quantity of motions that the test signal is tapped by a reduced test travel. This provides a travel sensor of particularly short dimensions which permits to use of Hall-effect sensors.

Abstract: A tandem master cylinder for hydraulic brake systems for automotive vehicles, with the brake systems comprising a brake pressure control means, in particular, an anti-locking control means. The tandem master cylinder has a push rod piston (7) and a floating piston (8), with each piston having a central valve. The valve closure member (13) of the central valve in the push rod piston (7) can be controlled both by a pin (16) directly or indirectly abutting the housing of the tandem master cylinder and by a pin (17) coupled to the floating piston.

Abstract: An electrohydraulic pressure control means for use with an anti-locking control system is provided with an integral assembly comprising an electronic controller (1) and a hydraulic unit. The hydraulic unit includes of an element (18) for accommodating electromagnetic valves and a lid (13). The lid (13) encloses coils (5, 6) protruding beyond the valve-accommodating element. The controller (1) and the hydraulic unit are interconnected by a mounting, positioning and anchoring device (3) and by an electrical contact (4). The anchoring device (3) is located in the area of the valve-accommodating element (18). The electrical contact (4) is provided between the lid (13) and the electronic controller (1). The anchoring device (3) absorbs outer forces imparted to the controller (1). The contact (4) provides a shielded and safe electric contact. Moreover, a valve block assembly for use with an anti-locking control system is provided.

Abstract: To control the pressure at the outlet of a pump and to position the pedal during a brake slip control action, an additional arrangement is provided to an existing master brake cylinder which arrangement comprises a transmission piston (5) as well as a shut-off valve (30). The closure member of the shut-off valve is loaded by way of a valve piston (28) and by the pressure in the brake line (18') in opposition to the pressure at the outlet of the pump. The valve closure member is thus pressure-balanced so that no forces are transmitted onto the tappet (37). Therefore, the ramp (40) at the transition piston (5) need not be separately hardened during the manufacturing process.

Abstract: A method is suggested for assembling a tandem master cylinder and a vacuum brake booster of a hydraulic brake system for automotive vehicles. Air is injected via the pressure connection (19) of the pressure chamber (18) associated with the push-rod piston (2). Simultaneously, the push-rod piston (2) is moved in the direction pointing away from the brake pedal. The pressure increase in pressure chamber (18) is measured during the movement of the push-rod piston and, thus, during the movement of the central valve (6) accommodated in the push-rod piston. As soon as the closure member (5) of the central valve is seated on the valve seat (4), thus the central valve being closed, the air pressure will increase in the chamber (18). In the curve of the "pressure-against-central-valve-travel" diagram, which curve indicates the pressure increase, a trigger point is established which determines a measured distance on the abscissa of the diagram.

Abstract: A tandem master cylinder for hydraulic brake systems of automotive vehicles. The push-rod piston (29) and the floating piston (34) both are provided with a central valve. The central valve of the push-rod piston is coupled to the floating piston. The length of the bore (28) of the central valve in the push-rod piston (29) is dimensioned to allow the valve closure member (27) of the central valve in the push-rod piston to travel a distance within the bore of the central valve at least equal to the stroke of the floating piston (34).

Abstract: An anti-lock hydraulic brake system comprising a separating valve (14) and a regulating valve (19). A combined arrangement is provided wherein the valves are connected into each other. The movability (play s) of the piston (30) affords the event that a compensating volume for the control action in the event that the output of the pump is insufficient in specific situations requiring a large amount of fluid for control.

Abstract: A tandem master cylinder for a hydraulic brake unit with slip control. In the housing of the brake unit a primary piston pre-loaded by a first return spring and a secondary piston pre-loaded by a second return spring define a primary and a secondary pressure chamber within a longitudinal bore. The pressure chambers are connected to a fluid reservoir and are associated with a first and a second control valve which release or shut off a second connection between the pressure chambers and the fluid reservoir depending on an actuating force. In order to reduce the overall axial length of the tandem master cylinder, the control valves (10, 11) are arranged outside the pistons (6, 7) and are actuated linearly by the pistons (6, 7).

Abstract: In a brake pressure regulator for a hydraulic brake system of automotive vehicles having an anti-locking control and/or a traction skid control and including a master cylinder and a hydraulic brake force booster, the actuating piston of the brake force booster along with a guiding member forms a modulator chamber. The pressure in the modulator chamber is varied by electromagnetically switchable blocking and passage valves thereby moving the actuating piston such that the force of the brake force booster is reduced and increased, respectively, thereby changing the pressures in the working chambers of the master cylinder. In this manner, in the control mode, the pressure in the wheel cylinders can be changed in accordance with a control algorithm to enable the brake pressure regulator to be operated in multiplex operation.

Abstract: The invention relates to a hydraulic unit for a hydraulic control device, in particular to a braking pressure control device as used in anti-skid control systems. Such hydraulic units include standardized valve blocks with electromagnetically operable valves. The standardization of the valve blocks implies that the pressure medium connections of the valve blocks have predetermined positions. The invention employs a distributing plate which has a system of channels, in particular in the form of punchings, and which, in a freely selectable manner, connects the valve blocks' connections, the positions of which cannot be changed, with connections of the other components of the control device. The invention provides good preconditions for manufacturing a large number of variants of hydraulic connections, thereby allowing series production of various configurations of braking pressure control devices for anti-skid control systems which are less expensive.

Abstract: There is described a power booster for actuating a master brake cylinder having a booster piston which is axially movable in a cylinder bore and which, with its peripheral surface, confines a pressure chamber connectible to a hydraulic pressure source and, with an end surface, confines a booster chamber that is connectible with a pressure chamber via a first closable valve passage. Via a second closable valve passage, the booster chamber is connectible with a compensating chamber connected to an unpressurized reservoir. The compensating chamber is bounded by the peripheral surface of a reaction piston and by a sleeve that is formed fast with the housing and encompasses the reaction piston. The second valve passage is disposed in a central bore in the reaction piston terminating into the booster chamber. Arranged in the central bore is an actuating rod which carries a valve element for closing the second valve passage and which extends into the first valve passage in the booster piston.

Abstract: The invention discloses a brake pressure regulator for anti-locking control and for traction skid control of automotive vehicles. The regulator comprises a master cylinder, a hydraulic brake force booster, an electronic controller which, based on sensor signals, at the output thereof, renders available variable signals according to a control algorithm to switch electromagnetic valves associated with the wheel cylinders, a pressure fluid source and a reservoir. A valve aggregate insures the adaptation of the pressure level from the pressure fluid source to the operating pressure desired for the TSC-mode and the ALC-mode. Moreover, the valve aggregate, with the brake applied, turns off the TSC-mode. The valve aggregate comprises at least one plunger/ball arrangement serving a the closing and/or control member. The advantages involved with this brake pressure regulator reside in the automatic pressure level regulation and the automatic turn-off of the TSC-mode.

Abstract: An anti-lock brake system with traction slip control includes a pedal-actuated, auxiliary-force-assisted braking pressure generator having a master cylinder to which the wheel brakes are connected by main brake lines, auxiliary-pressure hydraulic pumps, wheel sensors and electronic circuits for determining the wheel rotational behavior and for generating electric braking-pressure control signals which, for the purpose of brake slip control, serve to control electromagnetically actuatable pressure-fluid inlet valves and outlet valves provided in the pressure-fluid lines. Pistons of the master cylinder include central control valves which, in the brake's release position, open pressure-fluid connections between the pressure-fluid supply reservior and the pressure chambers and which, in the braking position, close the pressure-fluid connections. The brake lines communicate through supply lines with the pumps.

Abstract: A pressure differential valve, in particular for pressure fluid-actuatable motor vehicle brake systems, is disclosed and comprises a housing having a valve arrangement which is loaded by a preload force and which governs a connection between an inlet and an outlet. The preload force determines the gradient of pressure between the inlet pressure and the outlet pressure of the valve. In order to create a pressure differential valve which can be easily mounted and responds quickly at a low change-over pressure, the valve arrangement is actuatable by a tappet which is movable in dependence on the position of a diaphragm.

Abstract: A system is disclosed including valves which are opened or closed dependent upon the position of master cylinder pistons. Upon commencement of slip control, pumps supply fluid either into the slip control cycle or into the working chambers depending upon the position of the pistons. As a result, the pistons are reset until a pin of the valve reaches a ramp or cam and the valve opens. When the valve is open at the start of the control, the pumps first supply fluid into the open cycle, and the pressure fluid discharged from the wheel brakes for slip control is replenished out of the pressure chambers until the pin contacts the ramp or cam whereby pressure fluid supply from the pumps takes place.