Societe Anonyme D.b.a.

Bendix France

Alliedsignal Inc.

Bosch Systems De Freinage

Christian Tanguy

Gilbert Kervagoret

Guy Marouby

Roland Levrai

Jack R Phipps

Marc De La Broise

Pneumatic brake servo with an improved valve

A vehicle antilock braking system having an operator controlled master cylinder for developing a first source of pressurized fluid and a second source of pressurized hydraulic fluid for selectively supplying rebuild pressure after an antilock event to simultaneously provide for actuation of each wheel braking device. A solenoid operated first flow control valve for each wheel controls communication of either the first source or second source of pressurized hydraulic fluid to the braking device and the braking device to a low pressure return. A hydraulically operated second control valve has a first inlet port connected to receive the first source of hydraulic pressurized fluid and a second inlet connected to receive the second source of hydraulic fluid and an outlet port connected to the first flow control valve. A bypass pressure regulator responsive to the first source of pressurized fluid and the second source of pressurized fluid supplies pressurized hydraulic fluid from the second source to each of the hydraulically operated second control valve when the operator controlled master cylinder supplies the first pressurized hydraulic fluid to the braking device. The pressure of the second source is directly proportional to the pressure of the first source and when sufficient to overcome a resilient member in the second control valve is supplied to the first valve to independently operate braking device.

Flow control valve and pressure regulator for an anti-lock braking system

The invention relates to the control of a hydraulic jack which can be used, for example, for controlling the orientation of the rear wheels of a vehicle with front guiding wheels. In the event of a failure in the supply of fluid under pressure to the chambers (3, 4) of the jack, these chambers are isolated and the piston (2) is maintained in the position which it occupied when the failure occurred, by means of non-return valves (12). However, when certain conditions are satisfied, for example a sufficiently low speed, the electronic control member (20) activates an auxiliary circuit (30 to 39) in order to return the piston to its middle position and allow driving of the conventional kind with the rear wheels in line.

Control device with failure detection centering for a double-acting

The circuit comprises a primary circuit (2) feeding brake motors (5) and (7) and a secondary circuit (3) feeding a brake motor (9). In normal operation a valve (11) isolates the brake motor (22) from the secondary circuit (3). The pressure in the primary circuit then controls the pressure prevailing in the brake motor (22) with the aid of a pressure balancing device (25) installed between the feed lines of the brake motors (7 and 22). In the event of the failure of the primary circuit (2) the valve (11) establishes communication between the brake motor (22) and the secondary circuit (3) to effect the braking of the wheel associated with the brake motor despite the fact that the balancing device (25) is put out of action in this situation. Application to a brake circuit equipped with an anti-wheel-lock device.

Hydraulic circuit for a motor vehicle

The invention concerns a solenoid valve with three ways and three positions, having a general construction with symmetry of revolution about an axis (1) and incorporating a magnetic armature (4) which is movable in translation along this axis under the action of an electromagnetic coil (3) and of a return spring (10). This armature is hollow and incorporates internally two valves (56a, 56b), movable relative to one another and relative to the armature (4), separated from one another by a spring (12) and provided with flanges (11a, 11b) by the intermediary of which they can be displaced by the movable armature (4), facing respective fixed seats (7a, 7b) which they are capable of closing. Each valve is pushed to the closed position by the intermediary of a spacer block (13) in point contact at the point (C) with the valve (56b).

Three-way solenoid valve

A distributor of a hydraulic servo-mechanism is provided for power-assisted steering. According to the invention, the fluid circulation circuit defined by the interaction of two distributor elements (11, 13) consists of longitudinal grooves (40a, 40b) in the outer distributor element (11) and of holes (44, 45), some of which are blind, arranged radially in the inner distributor element (13). The holes have different diameters.

Rotary distributor for a hydraulic servo-mechanism

An accumulator charging valve has a housing with an inlet and two outlet orifices respectively connected to the pump outlet, to a fluid accumulator and to an open center hydraulic circuit. A main passage is provided between the inlet orifice and the second outlet orifice, with a movable valve member mounted in the main passage, and operated by a differential piston having a face of smaller diameter exposed to the pressure prevailing at the inlet orifice and a face of larger diameter projecting into a control chamber, forming a resilient variable volume enclosure. A leakage passage is provided between the inlet orifice and a low pressure reservoir and has a first portion with an orifice of restricted cross-section situated between the inlet orifice and control chamber, and a second portion also with an orifice of restricted cross-section situated between the control chamber and the reservoir. The first portion comprises pilot means for permitting or interrupting the flow through the leakage passage as a function of the pressure level prevailing in the chamber of the accumulator.

Charging valve for a fluid pressure accumulator

An electronic antiskid control unit for an adaptive braking system of the speed reference type wherein a signal for controlling decay of pressure is generated in response to comparison of the wheel speed signal with another signal. In a first phase, the wheel speed signal is compared with a reference signal derived from the wheel speed signal for generating the decay signal as long as the wheel speed reference signal is greater than wheel speed signal. At the end of this first phase, the wheel speed and speed reference signals have the same value and the speed reference signal is overridden by another increasing signal for comparison with the wheel speed signal thereby increasing duration of the decay. The other signal has three portions and is derived from a base signal having an exponential characteristic. At the end of the third portion, corresponding to intersection of the other signal with the wheel speed signal, the decay signal is extinguished.

Electronic antiskid braking control unit

In an input control unit for a vehicle anti-skid braking system, a wheel-speed sensor delivers speed signals to the first input of a differential amplifier. Simultaneously, a capacitor is charged through a resistor and a diode. The capacitor is discharged at a constant rate into a device connected to the second input of the differential amplifier. Another diode prevents the voltage across the capacitor from becoming higher than the voltage of the speed signals. The braking pressure is released for the duration of output signals produced by the differential amplifier. The duration of these signals is kept within safe limits due to the fact that the additional diode limits the voltage across the capacitor.

Growing community of inventors

Frepillon, France

Christian Tanguy