Wabco Westinghouse Gmbh

Regie Autonome Des Transports Parisiens

Wabco Westinghouse Equipements Ferroviaires

Wabco Westinghouse Equipements Ferroviaries

Wabco Westinghouse Equipements Ferroviaires S.a.

Regie Autonome Des Transports Prisiens 'ratp'

Michel Grenier

Daniel Cieplinski

Georges Dalibout

Laurent Meret

Christian Doireau

Gerard Leturgie

Yvers Thurin

Yves Thurin

Jean-Etienne De La Gorge

Jean-Etienne De La Gorce

A braking system having a disk brake that is mechanically connected to at least one wheel of the vehicle and cooperates with a brake caliper that is actuated by a threaded rod screwed through a threaded connection in a control nut rotatively mounted inside the caliper body, the threaded connection being irreversible by axial forces alone. The brake linings are made of an elastomeric material having a high friction coefficient when the disk is not rotating. This system provides a compact parking brake having a high power and a large remote-indication capacity, and is particularly useful in railroad vehicles.

Vehicle park braking system

Braking unit for vehicle, of the type comprising an axial actuating helical spring maintained in release position, against its elastic reaction force, through a screw-nut system rotatively driven by an electric motor, the spring acting upon the brake through the intermediary of a hydraulic master cylinder of which the piston is axially connected to an abutment ring of the spring also mechanically connected, via a screw-nut system to the rotor of an electric motor, such an unit being applied to a spring braking system for a vehicle possibly with a built-in park brake.

Spring brake unit and its application to a braking system

A dual-piston hydraulic brake master cylinder includes a large hydraulic piston which supplies an initial large brake fluid volume and a small hydraulic piston which continues to supply brake fluid to the brakes when the large piston stops moving forward in its cylinder at higher brake pressures. The small, central hydraulic piston is connected to the end of a piston rod extension of a pneumatic booster piston. The large piston surrounds the small piston and opens a reservoir line tilt-valve in the piston retracted position. A passageway between the large and small hydraulic chambers is open in the retracted position to allow communication of braking fluid therebetween. During brake actuation a seal arrangement interrupts this communication. The large and small hydraulic chambers supply the brake circuits through delivery passages.

Double-piston master cylinder with central booster-driven piston driving

A brake cylinder device combining a pneumatically-applied service brake and a spring-applied parking brake in a compact unit made possible by limiting the stroke of the parking brake piston to minimize the expansion of the spring and thus the amount of force relaxation, so that a relatively small spring may be used. The service brake piston carries a threaded shaft on which a nut is rotatably carried for locking engagement with the parking brake piston. The position of this nut during service braking is maintained in a predetermined position in proximity with the parking brake piston, by reason of a back-up spring imparting rotation, as the service piston takes up slack in the brake rigging, so that when the parking brake is subsequently applied, by locking engagement with the nut following only a short stroke, the stored energy of the spring acting through the parking brake piston, the nut and screw end of the service piston, and the service piston itself, substantially full force of the constrained parking brake spring is effective.

Brake cylinder device combining a pneumatically-applied service brake

A dynamic/friction brake blending valve device having a piston assembly arranged to operate a pressure regulator via which brake cylinder pressure is controlled. Associated with the relay valve device is an electrical circuit comprising a differential amplifier subject in a first mode of operation to a brake command signal and a dynamic brake signal representing the degree of dynamic brake effort being provided in response to the brake command. An error signal resulting from comparison of the brake command and dynamic brake signals is converted by a transducer to a corresponding fluid pressure that is supplied to a chamber formed between first and second differential pistons of the piston assembly to actuate the pressure regulator and thereby produce brake cylinder pressure corresponding to the deficiency of the dynamic brake. Another chamber formed between the second piston and a third differential piston of the piston assembly may be connected to a pneumatic control valve device that operates in response to brake pipe pressure variations, which may be made independently of the brake command signal, to provide apparatus for obtaining a back-up or emergency brake application in the event an electrical malfunction renders the differential amplifier inoperative. In a second mode of operation, the differential amplifier error signal is replaced by the dynamic brake signal and the brake pipe pressure is adjusted simultaneously with the brake command so as to correspond thereto. In this respect, the brake blending valve device itself accomplishes the comparison function provided by the differential amplifier in the first mode of operation, in order to supplement the dynamic brake with friction brake effort corresponding to any deficiency of the dynamic brake which may arise.

Braking coordination device

Growing community of inventors

Dampmart, France

Michel Grenier