Itt Industries, Inc.

Alfred Teves Gmbh

Bernd Schopper

Peter Tandler

Derek R Lowe

Peter Volz

Hans-Dieter Reinartz

Hans D Reinartz

Rolf Weiler

Dalibor Zaviska

Volker Berisch

Manfred Reuter

Herbert Hartmann

Wilhelm Ernst

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. The inlet valve and the outlet valve have an electronic coupling comprised of an inlet solenoid valve and of an orifice. In the control modus, said inlet solenoid valve will be switched and be brought into its closed position. Under the effect of the master cylinder pressure and/or the pump pressure, said valve is, now, given the function of a non-return valve, which remains in its closed position even while the actuating solenoid is in the de-energized condition. In this situation, pressure agent is restrictedly conveyed through the orifice to the wheel cylinder.

Brake pressure control apparatus

Braking pressure control device for a hydraulic automotive vehicle brake

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.

Hydraulic radial-type piston pump

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.

Load-sensitively controllable braking pressure control unit

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).

Braking pressure control unit for a dual-circuit vehicle brake system

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.

Process and apparatus for brake pressure control

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.

Dual-circuit pressure control valve

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. The formations have respective passages which register with one another in the assembled position of the components and which are surrounded by a seal arranged in the interface between the components.

Connecting arrangement, especially for tubular elements

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. This construction provides a space-saving arrangement which enables ease of assembly.

Tandem brake master cylinder

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.

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.

Braking pressure control unit for a hydraulic brake system

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.

An integral wheel brake cylinder and pressure regulating valve

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.

Dual-circuit pressure control valves

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.

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Hattersheim, Germany

Bernd Schopper