Abstract: 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.

Abstract: 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.

Abstract: 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.