Alfred Teves Gmbh

Itt Industries, Inc.

Continental Teves, Ag and Company Ohg

Alfred Toves Gmbh

Hans D Reinartz

Helmut Steffes

Peter Volz

Erhard Beck

Bernd Schopper

Jochen Burgdorf

Axel Hinz

Dalibor Zaviska

Andre F Goossens

Joachim Maas

Michael Jung

Franz Latka

Thomas Schwarz

The return pumps of brake systems with a precharging device are greatly stressed by the precharging pressure and subjected to premature wear. Significant leakage occurs in the long run which will damage the pump motors in the worst case. This is prevented by controlling the pressure fluid supply from the precharging source to the suction side of the return pump as a function of the pressure gradient in this connecting line. To this end, an electromagnetically operated on-off valve ( ) with a hydraulically insertable throttle is used.

Hydraulic brake system with a precharging device

Hydraulic brake system controlling slip

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

Method for assembling a piston-and-cylinder unit and force transmission

Anti-lock hydraulic brake system

The brake system includes a brake pressure generator with a master cylinder connected to wheel brake cylinders through master brake conduits; auxiliary pressure pumps having pump outlets in communication with the master brake conduits and pump inputs in communication with a pressure fluid reservoir through inlet conduits; wheel sensors and electronic circuits for determining the wheel rotating pattern and for generating electrical brake pressure control signals capable of controlling pressure fluid inlet and outlet valves disposed in the conduit system for slip control. The traction slip control system insures, with little effort involved, assembling and disassembling capabilities, and, in disassembled condition, complying with the control principle for a driven front axle and, in assembled condition, complying with the traction slip control mode for a driven rear axle in all speed ranges. The present invention provides an accumulator with a single connection in communication, with the master brake conduit, with an electromagnetic valve having a pressure monitoring switch coupled thereto and provided with a bypass enclosing a release valve located between the connection and the accumulator.

Pressure fluid-activated brake system including an anti-locking traction

A pressure supply system for the generation of the auxiliary pressure of a hydraulic brake system for motor vehicles comprises an accumulator, a hydraulic pump driven by electromotive force and a pressure switch (1) controlling the turning on and off of the hydraulic pump. The pressure switch (1) includes a switch piston (2) having a piston rod (5) mechanically actuating in a pressure-responsive manner, successively, two or three switches (8,9,10). The pump motor (26), by way of these switches, and by way of a relay, is turned on when a bottom pressure limit value (P.sub.U) is reached, and turned off when the upper pressure limit value (P.sub.O) is reached and exceeded. A holding circuit is connected in the electric circuit, in which are provided the switches (8,9,10) of the pressure switch (1), which holding circuit ensures an abrupt switch-over of the relay into the other switching position when a slow approach of a pressure (p) to the pressure limit values (p.sub.U, P.sub.O) causes fluttering of the relay contacts.

Pressure supply system especially for brake systems of motor vehicles

A slip-controlled brake system is disclosed having a hydraulic power booster and a master cylinder arranged downstream of the power booster, wherein the pressure chamber of the power booster can be acted upon by an external pressure depending on the position of a pedal-actuatable brake valve, and wherein a fast-fill cylinder is provided which can be acted upon by the dynamic pressure and through which additional pressure fluid can be supplied to the brake circuits of the master cylinder. The fast-fill cylinder is equipped with a three-step bore wherein a piston with three shoulders is longitudinally displaceably arranged. A chamber in front of the large drive surface of the piston is connected to the dynamic brake circuit through a pressure fluid line and a chamber in front of an end face of the small step is connected to a static brake circuit through a second pressure fluid line. A first annular chamber formed between the large shoulder of the piston and the medium-sized step of the stepped bore than communicates with a second annular chamber formed between the medium-sized shoulder of the piston and the small step of the stepped bore through a pressure fluid channel and a valve. The second annular chamber is connected to a return line. In the event of a brake pressure control, additional pressure fluid flows from the chamber in front of the small step of the piston of the fast-fill cylinder into the brake circuit through the pressure fluid line. In this case, the fast-fill cylinder operates independently of the functioning of the anti-lock system.

Slip-controlled brake system

The present invention relates to a traction slip control device comprising a sensor which responds to a beginning slip condition on at least one of the driving wheels and, connected to the sensor, a control circuit which via an auxiliary drive in the form of a fluid which actuates the throttle valve of the drive engine in the closing sense when the sensor detects a slip condition and feeds a slip signal to the control circuit.

Traction slip control device

A vacuum brake force booster is provided wherein the pressure column above the immersing valve plunger of the dual valve contained in the piston chamber, in the applied position, generates a reaction force imparting to the vehicle drive the feeling of the extent of deacceleration. In addition to the valve plunger coupled to the push rod of the brake pedal, the control housing in the piston chamber is displaceable in the brake housing along with the movable wall and acts as a plunger piston. For this purpose, the control housing is sealingly passed through a wall of the master cylinder. The intermediate piston separating the two piston chambers in the master cylinder at the front side thereof facing the valve piston is provided with a rubber reaction disc. The valve plunger and the control housing or a sleeve cooperating with the control housing, in the event of a failure of one of the brake circuits, will abut the reaction disc.

Vacuum brake force booster

A hydraulic brake system with slip control for automotive vehicles comprising a master cylinder (2) pressurizable by a hydraulic power booster (1), in which system valve(s) (31,27,32,28,33,23) are inserted between the master cylinder (2) and the wheel brakes (29,30,24,25) connected to the master cylinder (2) which allow pressure fluid removal from the wheel brakes (29,30,24,25) that can be replenished out of the pressure chamber (19) of the hydraulic power booster (1) by way of a change-over valve (36). A stroke limitation of the brake pedal (8) is effected during slip control. The end surface of the master cylinder piston (5) close to the working chamber (16) being larger than the is effective surface of the booster piston (4), and wherein a stepped piston is employed as master cylinder piston (5) with an annular surface (18) thereof being adapted to be acted upon in the actuating direction by the pressure prevailing in the working chamber (16). A non-return valve (37, 38) is connected to the change-over valve (36) normally assuming its closed position through which the wheel brakes (29,30,24,25) can reacted upon directly by the pressure prevailing in the pressure chamber (10) of the hydraulic power booster (1).

Hydraulic brake system with slip control

The present invention starts from a vehicle hydraulic brake system comprising a master cylinder (2) actuatable by a hydraulic power booster (1) and containing a working chamber (12, 21), to which latter wheel brakes (36, 37, 38, 39) are connected by way of valves (40, 41) controllable by a slip control electronics. On control action, pressure fluid can be taken from the wheel brakes (36, 37, 38, 39) through the valves (40, 41) and can be replenished out of the presser chamber (5) of the hydraulic power booster (1) by way of the working chamber of the hydraulic power booster by way of the working chamber (12, 21). On communication of the working chamber (12, 21) with the pressure chamber (5) of the hydraulic power booster (1), simultaneously, a resetting sleeve (11) is pressurized in the brake's release direction which is penetrated by a master cylinder piston (10) and which serves to limit the stroke of the brake pedal (6). In particular with a view to simplifying the design of the braking pressure generator (1, 2), it is proposed that an annular housing chamber (15), which is confined by the end face of the resetting sleeve (11) that is remote from the working chamber (12), is normally isolated from an unpressurized supply reservoir (18) and is in communication to said supply reservoir (18) exclusively during brake slip control.

Vehicle hydraulic brake system

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.

Dual-circuit pressure control valve

In a pressure control valve for a hydraulic brake system for vehicles, the closure member is carried by a control piston which has one of its ends guided through an annular seal and in a housing bore, which is preferably connected to atmosphere, and carries adjacent its other end a support plate for engagement with a valve spring. The valve seat is part of an annular body encircling the control piston and held in place by a tubular body surrounding the annular body and the control piston and secured to the housing. A return channel is formed between the annular body and the tubular body and incorporates therein a check valve opening in the direction from the outlet chamber to the inlet chamber. The annular seal is in abutment with a step in the housing and the annular body is in abutment with an inner flange of the tubular body. To obtain a minimum possible overall axial length, the annular body and the annular seal are arranged adjacent each other, leaving a clearance for radial channels. An elastic profile ring serves both as a valve seat and as a closure member of the check valve. The profile ring may be formed separate from or integral with the annular seal.

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Frankfurt am Main, Germany

Hans D Reinartz