Abstract: A brake pressure control apparatus for automotive vehicles with an anti-locking control system is presented. It is comprised of a master cylinder, of one or of a plurality of wheel cylinders for wheel brakes, of a pressure modulator for the modulation of the hydraulic pressure in the wheel cylinders of the wheel brakes during a brake pressure control modus, of at least one motor-driven pump for the generation of a hydraulic pressure, of an electronic controller. The outlet valve associated with a wheel cylinder is furnished with a closing element (5) which is connected to the closing element (6) of the inlet valve through a captivating apparatus which is configurated and positioned in such a manner that in its closing position the said closing element (5) of said outlet valve opens the said closing element (6) of said inlet valve and in its open position it closes said closing element of the inlet valve.

Abstract: A brake pressure control system for automotive vehicles with an anti-locking control system is disclosed, in which an outlet valve (10) associated with a wheel cylinder has a closing element (5) which is coupled to the closing element (6) of the inlet valve (11) through a coupling housing (14) so that the closing element (5) of said outlet valve opens the closing element (6) of the inlet valve (11) and in its open position it allows closing of the closing element of the inlet valve. A plurality of valve chambers and the action of a self regulating a control bushing (48) which also acts as the coupling, a flow limiting valving action to the wheel cylinder (2) is attained. In another embodiment, inlet and outlet solenoid valves are operated by a single common electrical line, the inlet valve held closed despite deenergization by inlet fluid pressure from the master cylinder or pump as long as the pressure therefrom is greater than the pressure in the wheel cylinder.

Abstract: A braking pressure control device for a brake system comprising a braking pressure generator (16), a wheel brake cylinder connected via a brake line (15) with the latter to actuate a brake (18), a braking pressure control circuit which is interposed into the brake line and comprising a piston pump, the outlet valve (9) of which is connectible to the brake line (15), and comprising solenoid operated brake control valves (19, 20), the inlet valve (8) and the outlet valve (9) of the piston pump are arranged on the pump housing (1), and the difference in pressure for opening the inlet valve (8) is such that the inlet valve (8) remains closed whenever the pressure in the return line (21) is below atmospheric pressure.

Abstract: A radial piston pump is described with dual pistons which are slidingly accommodated within a bushing coupled end to end to a valve body. Automatically controlled suction and discharge valves for a pressure chamber are arranged one behind the other in the longitudinal axis of the pump. The pistons are sealed by means of elastomeric seals compressed by an end of the valve body and bushing under pressure of a threaded sealing plug installed in the pump housing. The valves, valve body and bushing form a cartridge separately assembled and installed as a unit in the housing. The threaded sealing plug is formed with a damping chamber for damping of pressure pulsations.

Abstract: A braking pressure control unit is disclosed, including a transmission lever acting on actuating tappets of a control valve, the lever is articulated through the intermediary of a first spring arrangement attached to a vehicle part which changes its position relative to the braking pressure control unit in a load-sensitive manner. Between the transmission lever and the control valve actuating tappets, a second spring arrangement is provided, which urges the transmission lever against a stop affixed to the housing. The transmission lever is adjusted to provide a clearance between the lever and the actuating tappets. When the setting of the load-sensitive transmission arrangement is clearance-free, incorrect adjustments of the control valve will not cause appreciable variations of the valve change-over pressure.

Abstract: A braking pressure control unit comprises a valve assembly with a valve seat (25) formed fast with the housing and a closure member (26) which latter, with the brake circuits (I, II) intact, when performing its relative movement to the valve seat (25), is kept in abutment on an extension (II) of a stepped piston (6) by a closure spring (28) supported on a malfunction piston (7). The valve (25, 26) is prevented from closing by the extension (11) at the stepped piston (6) and by a stop (29) for the closure member (26) at the malfunction piston (7). Because of the closure member (26) being in constant abutment on the extension (11) of the stepped piston (6) during its relative movement, there results a smaller stroke of the malfunction piston (7) and thus less fluid input of the braking pressure control unit and less wear of the sealing elements (22, 23) at the malfunction piston (7).

Abstract: In the process, a spring device is pivotally connected to a transmission lever which is movable between two defined positions. The free end of the spring device is subjected to a defined load and is fixed stationary while the transmission lever is in the defined position corresponding to the closing position of the valve. Thereupon, the length of the prestressed spring device is fixed, which results after swiveling of the transmission lever into the other defined position. The effect of the spring tolerances on the precision of adjustment of the change-over point is excluded. The brake pressure control unit apparatus is provided with first and second stop elements fastened to the spring device with a removable spacing element inserted between the stop elements. The distance between the stop elements corresponds to a determined amount of spring preload fixed by the spacing element.

Abstract: Dual-circuit pressure control valves are known in which the two control pistons are acted upon by a common preloading force through the intermediary of a preload distributor. The disadvantage of the known devices is that the valve closure travel is great resulting in a large fluid volume input to the control valve. According to the present invention this disadvantage is overcome by providing adjustable stops which cooperate with corresponding extensions of the distributor as soon as an unsymmetrical mode of operation of the valves occurs.

Abstract: A connecting arrangement for connecting two hollow components of a hydraulic circuit to one another, especially a pipe or hose to a mating component, includes a guiding formation on one of the components, especially the mating component, and a mounting formation connected to the other component, these formations having correlated cross-sectional shapes such that the guiding formation guides the mounting formation in a predetermined direction, especially the longitudinal direction of the one component, and prevents relative displacement in all other directions. The mounting formation is advantageously constituted by a separate mounting element which is affixed to the other component by a threaded connection, such as by a screw cap. The formations advantageously have complementary dovetail-shaped cross-sectional configurations.

Abstract: A tandem brake master cylinder comprising a longitudinal bore having two pressure chambers therein each associated with a different one of two pressure pistons, each of the two pressure chambers and its associated one of the two pressure pistons are associated with a different one of two brake circuits. Two parallel inlet sockets are provided in the housing of the tandem master cylinder, each of the two inlet sockets connecting a different one of the two pressure chambers to a brake fluid reservoir. A transverse bore is also provided in the housing of the tandem master cylinder containing a pressure control device for one of the two brake circuits, the control device including a stepped piston and a valve controlled by the stepped piston. The transverse bore intersects a plane containing the axes of the two inlet sockets in an approximate perpendicular manner between the two inlet sockets and beween the longitudinal bore and the reservoir.

Abstract: Dual-circuit brake force control systems are known in which the initial preloading force is changeable dependent on the vehicle load. The initial preloading force is distributed to the control pistons by a lever. Due to manufacturing tolerances and erosion of the individual elements, considerable differences in pressure in both brake circuits may occur. Therefore, according to the instant invention a control lever is provided to directly actuate both control pistons and which is rotatable about an axis perpendicular to the axes of the control pistons and also rotatable about the longitudinal axis of the lever. A holding member shaped like a ball bearing enables the lever to rotate about these two axes. Adjustable stops are provided which cooperate with circular stop surfaces extending from the lever on opposite sides of the longitudinal axis with the center of the stop surfaces being disposed in a plane parallel to the longitudinal axes of the control piston and containing the axes of the control piston.

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: A brake pressure regulating valve inserted inside the pressure chamber of a wheel brake cylinder of a vehicle comprises a differential or stepped piston having its smaller diameter section slidably supported in a bore of a wheel brake cylinder piston and its larger diameter section guided in the bore of a housing for the wheel brake cylinder. The larger diameter section of the stepped piston has an internal bore between an inlet chamber and an outlet chamber. A regulating valve controlling the inlet of the internal bore is provided by a sealing ring resting against a surface of the larger diameter section of the stepped piston adjacent the inlet chamber and an adjacent end of the wheel brake cylinder piston.

Abstract: In general pressure regulators for motor vehicle brake systems are arranged in the pressure medium line between the master brake cylinder and at least one wheel brake cylinder. The pressure regulator comprises a plunger valve with different pressure surfaces, which above a certain pressure level, reduce the brake pressure of the rear axle compared to the brake pressure of the front axle. In order to achieve a high reliableness and a simple construction of the pressure regulator, a non-return valve in the form of a sealing lip movable by a movable part of the plunger valve is provided. The sealing lip extends into the inlet chamber when the plunger valve is closed and closes a channel which leads through the valve plunger and/or valve body to the outlet chamber.

Abstract: In a known dual-circuit braking pressure control valve, a tilting lever arrangement is provided for distribution of the preloading force to the two control pistons, whereby the change-over point of the intact brake circuit is increased upon failure of one brake circuit. The tilting lever arrangement is complicated with respect to its construction and assembly, and its mode of operation is not safe. According to the present invention the tilting lever arrangement is replaced by a carrier bridge at the ends of the two pistons which synchronizes the points of application of the preloading forces by allowing a slight relative movement betweeen the two pistons when both of the brake circuits are operative.

Abstract: A pressure reducer for hydraulic brake systems comprises a stepped piston carrying a sealing ring in a circumferential groove thereof. The sealing section of the sealing ring begins at the groove wall adjacent the outlet chamber and joins a transitional section of smaller diameter adjacent the inlet chamber. The sealing ring fills the groove essentially completely at least in the sealing section. Preferably the sealing ring abuts the bottom of the groove over its entire axial length. This results in a defined position for the sealing section without excessive friction and wear occurring during operation.

Abstract: Dual circuit pressure control valves for brake system are known in which the control pistons are located parallel to each other with each control piston controlling a different one of two brake circuits. Both control pistons are loaded by a common preloading force. The known arrangement is complicated in its construction and has a large overall length. According to the present invention, the construction is simplified and the overall length is reduced by providing a torsion spring which provides the preloading force acting on the control pistons via stationarily supported swivelling levers.

Abstract: Dual circuit brake force control units are known in which the initial preloading force is changeable dependent on the vehicle load. The preloading force is distributed to the control pistons by means of a lever. Due to the tolerances and erosion of the individual elements, considerable differences in pressure in both brake circuits may occur. Therefore, according to the present invention a lever is provided which directly acts on both control pistons and which is rotatable around an axis parallel to the direction of displacement of the control pistons and additionally around the longitudinal axis of the lever. The lever is in interaction with its housing mount at one support point at least and at two support points at the most with the support point or support points being located at least approximately in the longitudinal axis of the lever.

Abstract: In a dual-circuit pressure control valve for hydraulic brake systems, the control pistons disposed parallel to one another are each loaded by a first arm of an associated angular lever. Each of the levers have a second arm perpendicular to the first arm acted upon by a common tension spring disposed therebetween. The levers are located approximately in a plane defined by the axes of the control pistons. The tilting axes of the levers are disposed perpendicular to this plane and are disposed outside the axes of the control pistons. This results in a short overall length in both the axial and radial direction. In addition, a carrier device is provided which couples one of the control pistons with the lever of the other control piston after a small relative movement of the control pistons. This carrier device becomes effective upon failure of one brake circuit. The carrier device may be formed by extensions of the first arms which overlap one another with play.

Abstract: Dual-circuit pressure control valves are known in which the control pistons are acted upon by a common control force. A preload distributor constructed as beams of balance to compensate for differences in the control behavior of the two control valves due to manufacturing tolerances have not provided the desired compensation. Therefore, according to the present invention an improved compensation arrangement is provided in the form of a compensating piston which is subjected to the outlet pressures of the two brake circuits.