A relay valve is provided for a vehicle. The valve includes a parking brake piston that is displaceable in a housing and an axially displaceable cuff, a first compressed-air chamber for receiving compressed air from a control line is formed between the parking brake piston and the housing. The valve is also provided with a first spring element, which axially applies a pre-loading force to the cuff, and with a second spring element, which axially applies another pre-loading force to the parking brake piston. An axially displaceable service brake piston is arranged axially between the parking brake piston and the cuff, the service brake piston rests at least radially against the parking brake piston and radially against the housing in a sealing manner, in order to form a second compressed-air chamber.

A control valve for automatic compressed-air brakes forms a brake cylinder pressure in at least one connected brake cylinder in accordance with a pressure difference between a pressure in a continuous main air line of a train and a stored reference pressure, which is drawn from the pressure of the main air line, comprising valve means for drawing a control pressure from the pressure of the main air line in order to produce a brake cylinder pressure for applying to the brake cylinder. A first piston system provides the control pressure from the pressure of the main air line and a valve mechanism for producing the brake cylinder pressure, wherein a short-stroke first piston system actuates the accelerating element in the same valve housing interacts with a second piston system for actuating the valve mechanism, the second piston system being of longer stroke in relation to the first piston system.

An air brake relay valve includes an air guide unit having a movable set, a drive unit having a motor and a worm shaft, and a cam unit having a transmission member and a driven member. During a brake action, the motor rotates the worm shaft to rotate the transmission member so as to push the driven member downward to thereby move the movable set to a communicating position where a first valve opening and a second valve opening fluidly communicate with each other. When the brake action is released, the motor rotates reversely so that the driven member is moved upward and that the movable set moves, without being applied with additional force, to a non-communicating position where the first and second valve openings do not fluidly communicate.

An air brake relay valve includes an air guide unit having a movable set, a drive unit having a motor and a worm shaft, and a cam unit having a transmission member and a driven member. During a brake action, the motor rotates the worm shaft to rotate the transmission member so as to push the driven member downward to thereby move the movable set to a communicating position where a first valve opening and a second valve opening fluidly communicate with each other. When the brake action is released, the motor rotates reversely so that the driven member is moved upward and that the movable set moves, without being applied with additional force, to a non-communicating position where the first and second valve openings do not fluidly communicate.

An electronically controlled pneumatic (ECP) overlay control valve can selective switch between a conventional pneumatic mode and an ECP mode. In ECP mode, the overlay control valve shunts the brake cylinder pressure of the pneumatic control valve which allows a relay valve to build or exhaust pressure in the brake cylinder in response to an electronically controlled apply/release circuit. In conventional pneumatic mode, the overlay control valve disconnects the relay valve and allows a conventional pneumatic control valve to control the pressurization and exhausting of the brake cylinder.

An electronically controlled pneumatic (ECP) overlay control valve can selective switch between a conventional pneumatic mode and an ECP mode. In ECP mode, the overlay control valve shunts the brake cylinder pressure of the pneumatic control valve which allows a relay valve to build or exhaust pressure in the brake cylinder in response to an electronically controlled apply/release circuit. In conventional pneumatic mode, the overlay control valve disconnects the relay valve and allows a conventional pneumatic control valve to control the pressurization and exhausting of the brake cylinder.

A control valve for an automatic parking brake having an inlet for coupling to a source a brake pipe pressure, an outlet for coupling to a control inlet of the automatic parking brake and a pilot for coupling to the source of brake pipe pressure. The control valve is moveable between a first position where the inlet is in communication with the outlet and a second position where the inlet and the outlet are isolated from each other in response to a predetermined amount of brake pipe pressure at the pilot. The control valve includes a spring biasing the control valve into the first position.

An air brake relay valve includes an air guide unit having a movable set, a drive unit having a motor and a worm shaft, and a cam unit having a transmission member and a driven member. During a brake action, the motor rotates the worm shaft to rotate the transmission member so as to push the driven member downward to thereby move the movable set to a communicating position where a first valve opening and a second valve opening fluidly communicate with each other. When the brake action is released, the motor rotates reversely so that the driven member is moved upward and that the movable set moves, without being applied with additional force, to a non-communicating position where the first and second valve openings do not fluidly communicate.

A valve module is provided for enabling a vehicle to control an autonomous event of the vehicle. The valve module comprises a relay valve, a first solenoid valve, and a second solenoid valve. A first control pressure can be delivered through the first solenoid valve and applied to a control port of the relay valve. In one embodiment, a second control pressure can be delivered through the second solenoid valve and combined with the first control pressure. The combined first and second control pressures are applied to the control port of the relay valve.

A valve module is provided for enabling a vehicle to control an autonomous event of the vehicle. The valve module comprises a relay valve, a first solenoid valve, and a second solenoid valve. A first control pressure can be delivered through the first solenoid valve and applied to a control port of the relay valve. In one embodiment, a second control pressure can be delivered through the second solenoid valve and combined with the first control pressure. The combined first and second control pressures are applied to the control port of the relay valve.