A parking brake system for electrically controlling a parking brake of a vehicle is provided. The parking brake system includes a parking brake provided for each wheel, an air dryer controller, and an actuator. The air dryer controller is provided to an air dryer to electrically control the parking brake. The air dryer dries compressed air for use in the parking brake. The actuator is provided for each axle of the wheel to actuate the parking brake with the compressed air in accordance with an electric signal from the air dryer controller.

A pre-filling device for a braking system. The pre-filling device includes a pre-filling channel, a pre-filling pressure being inside the channel when the braking system is in a rest and hydro-boost position, and a mechanical valve configured to be opened following a transition from the rest and hydro-boost position to a working position of the braking system; and a hydraulic valve cooperating with the mechanical valve setting the pre-filling pressure inside the channel. The hydraulic valve includes in a first area, facing the mechanical valve, a hole communicating with the channel, and in a second area, hydraulically isolated from the first area, a preloaded resilient element in a chamber held at atmospheric pressure. The hydraulic valve is configured to be connected or not to be connected, by a reciprocating movement inside the channel, to a hydro-booster device and to keep a predetermined pre-filling pressure upon varying of the hydro-boost pressure.

A spring brake actuator is for braking a wheel of a vehicle and has a push rod assembly having a base located in a service brake chamber and a push rod extending from a service brake chamber. Pneumatic activation of the spring brake actuator causes the push rod to further extend out of the service brake chamber to thereby engage a wheel brake with a wheel of the vehicle. Pneumatic deactivation of the spring brake actuator causes the push rod to retract back into the service brake chamber to thereby disengage the wheel brake from the wheel of the vehicle. The push rod extends between a first end portion that is fixed to the base and an opposite, second end portion that is removably coupled to the first end portion so that the second end portion is manually attachable and detachable from the push rod assembly.

A parking brake device has at least one first connection line for connection to a compressed air source and at least one second connection line for connection to a compressed air source. At least one first compressed air output line for direct and/or indirect connection to a spring brake actuator, and at least one further redundant compressed air output line for direct and/or indirect connection to a redundant brake system, are provided.

A parking brake device for a motor vehicle, in particular a utility vehicle, includes at least one compressed air connection, at least one first control solenoid valve unit, at least one trailer control bistable valve, and at least one first compressed air outlet. The compressed air connection is connectable to the first control solenoid valve unit and the trailer control bistable valve. The first control solenoid valve is connectable to the trailer control bistable valve via at least one first control line. The trailer control bistable valve is connectable to the first compressed air outlet via at least one trailer control outlet line. The parking brake device has at least one towing vehicle control bistable valve and at least one second compressed air outlet. The compressed air connection is connectable to the towing vehicle control bistable valve. The towing vehicle control bistable valve is connectable to the second compressed air outlet via at least one towing vehicle control outlet line. At least one towing vehicle outlet branch is arranged in the towing vehicle control outlet line between the towing vehicle control bistable valve and the second compressed air outlet. The first control solenoid valve unit is connectable to the towing vehicle control outlet line via at least one bypass control line and via the towing vehicle control outlet branch.

A brake system includes a first electric power-supply-unit (EPSU) and a first electronic-brake-control-unit (EBCU). The first EBCU is connected to the first EPSU. Also, the brake system includes a second EPSU and a second EBCU, which is connected to the second EPSU. The brake system further includes a first axle-pressure-modulator (APM) for service-brake-chambers associated with a first vehicle-axle. The brake system includes a second APM for spring-brake-cylinders for a second vehicle-axle. The brake system includes two power-supply-switches (PSS). A first PSS is connected to the first EBCU, the second EBCU and the first APM and configured to connect the first EBCU or the second EBCU to the first APM. A second PSS is connected to the first EBCU, the second EBCU and the second APM and configured to connect the first EBCU or the second EBCU to the second APM.

A spring brake actuator has a combined housing including a first housing, a second housing, and connection part connecting the first housing and the second housing. Gas inlet ports are disposed along the circumference of the combined housing in a gas inlet port section. A mechanical connection section is disposed in the same axial space as the gas inlet portion section. A bayonet connection is arranged in the mechanical connection section, with gas inlet ports disposed between the bayonet elements. Port connectors may extend through recesses or holes and be threaded into the gas inlet ports, and which may block the bayonet connection and block relative rotation between the first and second housings. The connection part may include a ring shaped protrusion form fit with a protruding of the second housing, with the bayonet elements disposed at the opposite end of the connection part engaged with the first housing.

A spring brake actuator has a combined housing including a first housing, a second housing, and connection part connecting the first housing and the second housing. Gas inlet ports are disposed along the circumference of the combined housing in a gas inlet port section. A mechanical connection section is disposed in the same axial space as the gas inlet portion section. A bayonet connection is arranged in the mechanical connection section, with gas inlet ports disposed between the bayonet elements. Port connectors may extend through recesses or holes and be threaded into the gas inlet ports, and which may block the bayonet connection and block relative rotation between the first and second housings. The connection part may include a ring shaped protrusion form fit with a protruding of the second housing, with the bayonet elements disposed at the opposite end of the connection part engaged with the first housing.

The disclosure is directed to a fail-safety valve unit for a parking brake function of an electronically controllable pneumatic braking system for a utility vehicle. The fail-safety valve unit has a monostable release valve and a ventilating valve. The release valve, when energized, provides a release pressure at a first release valve port for the parking brake function and, when de-energized, connects the first release valve port to the ventilating valve. The ventilating valve has a nonlinear ventilating characteristic which permits ventilating of the release valve port from the release pressure to a partial brake pressure with a first gradient, and ventilating of the release valve port from the partial brake pressure to a full brake pressure with a second gradient, wherein the first gradient is greater than the second gradient. A parking brake module and a vehicle are part of the disclosure.

An electropneumatic control module has a trailer control unit, which has a trailer brake pressure port and a trailer feed pressure port, a holding brake unit, which has a spring-type actuator port and a holding brake pilot control unit, and an electronic control unit, which switches a holding brake pilot control unit into a ventilation position, wherein a second holding brake pilot control port is connected in pressure-conducting manner to a first holding brake pilot control port and the spring-type actuator port is connectable to a vent. The holding brake unit is connected to a redundancy port and is configured to output a first holding brake pressure at the spring-type actuator port when the holding brake pilot control unit is in the ventilation position and a redundancy pressure is provided. The trailer control unit outputs a brake pressure at the trailer brake pressure port when a redundancy pressure is provided.