A spring brake actuator assembly for actuating a brake includes a spring chamber and a service chamber. A central flange defines opposing first and second cup-shaped sections. A spring chamber housing is interconnected to the first cup-shaped section of the central flange case for defining a spring chamber. A reciprocating piston is disposed in the spring chamber and includes a tubular push rod being biased into the service chamber from the spring chamber by a power spring disposed between the spring chamber housing and the reciprocating piston. The spring chamber is sealably bifurcated into a spring portion and a brake release portion. The brake release portion is subject to pneumatic pressure for compressing the power spring disposed in the spring chamber. A service flexible diaphragm defines the service chamber that is also subject to pneumatic pressure for driving a push rod outwardly of the service chamber to actuate a brake.

A method is for operating a vehicle's electropneumatic brake system. The brake system includes a service brake system and a parking brake system. The parking brake system includes a spring brake cylinder. A control signal for maintaining a spring brake pressurization pressure, which pressurizes the spring brake cylinder, is provided via a control unit. The provision of the control signal is suspended in at least one of a fault event and/or in the event of an electrical failure and/or in a diagnostic event of the control unit and thus automatically ending the maintenance of the spring brake pressurization pressure to ventilate the spring brake cylinder and thus initiating a spring brake failsafe braking operation of the vehicle via the parking brake system. The ventilation of the spring brake pressurization pressure is performed by a service brake ventilation function of the service brake system.

The invention relates to an electrohydraulic brake release device (1) comprising an actuating cylinder arrangement (400), a tank module (300) for receiving a hydraulic medium, an electric drive unit (200) and a functional unit (100) having a pump assembly (113). The pump assembly (113) is arranged in a recess (111) provided in the functional unit (100), which recess is in communication with the tank module (300), is functionally connected to the actuating cylinder arrangement (400) by way of a conduit arrangement (150, 160, 170, 171, 172, 180, 190) and by way of a bearing carrier cover (115) is sealed off from a dry-running drive motor (210, 211) of the electric drive unit (200). The invention further relates to a brake system comprising a brake release device of this kind.

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 compressed air system for a motor vehicle with an air supply system, including: an electric drive motor, which can be controlled for variable speed, an air compressor coupled to be driven by the electric drive motor, an electric power supply for supplying electric power to the electric drive motor, at least one air reservoir connected with the air compressor to receive air from the air compressor, an air utilization system connected to the at least one air reservoir to receive air from the at least one air reservoir, a controller to control the speed of the electric drive motor. The controller controls the electric drive motor to determine the speed of the electric drive motor so that during filling of the air reservoir, when the pressure level in the air reservoir passes a setpoint that is between a minimum level and a higher cut off pressure level, the controller changes the compressor speed so that specific power consumption per unit mass of air compressed is decreased.

The disclosure relates to a pneumatic braking system comprising a service brake actuator; an electro-pneumatic modulator unit for receiving an air control pressure representative of a driver's braking request; delivering, by a regulation unit, a modulated air pressure to a service brake chamber; a parking brake actuator; a parking brake unit for delivering a second air pressure to a parking brake pneumatic chamber; and an isolation device for when the isolation device is electrically energized, preventing the delivery of the air control pressure to the regulation unit, and for when the isolation device is not electrically energized, allowing the delivery of air control pressure to the regulation unit when the second air pressure is higher than a threshold, and preventing the delivery of air control pressure to the regulation unit when the second air pressure is lower than the threshold.

A system for controlling a parking brake may include an air compressor that generates compressed air, an air dryer that transmits the compressed air, a pressure protection valve that supplies the compressed air from the air dryer to a service brake flow path connected to a spring brake chamber of a brake and a parking brake flow path, an additional parking brake flow path connected between the air dryer and the pressure protection valve, a double check valve including first and second inputs connected to the additional parking brake flow path and the parking brake flow path respectively, and transmitting a higher pressure among a first input pressure of the first input and a second input pressure of the second input through an output port of the double check valve, and a parking valve which is provided on a flow path connected from the output port of the double check valve to a parking port of the spring brake chamber and is configured to control a parking brake operation of the brake-rear.

A pneumatic braking device for a utility vehicle includes at least one pneumatically controllable spring accumulator for a parking brake of the utility vehicle and an electronic parking brake device. The electronic parking brake device has at least one electronic control unit, at least one bistable valve unit, at least one first valve unit by which a parking brake of a trailer of the utility vehicle can be deactivated when activating the parking brake of the utility vehicle, at least one second valve device which can be connected in such a way that when there is a decrease in the system pressure for supplying the parking brake of the trailer, the parking brake of the trailer can be activated, and a traction vehicle protection valve.

A control method for controlling a spring loaded brake actuator (9) comprising a first chamber (Ch1) to receive a parking brake pressure (PBR) acting against a main spring (92), and a second chamber (Ch2) to receive a service brake pressure (SB) for applying a service brake force, the method comprising a circumstantial selection of one control law among a set of control laws comprising two or more compound control laws: where the first compound control law (CL1), known as anti-compound mode, is such the service brake pressure (SB) is electronically controlled such that the resulting total braking force (F) does not exceed a first upper limit (UL1) corresponding to the force of the main spring (92) when the parking brake pressure (PBR) is substantially null, where the second compound control law (CL2), known as controlled-compound mode, is such that the service brake pressure (SB) is electronically controlled such that the resulting total braking force (F) does not exceed a second upper limit (UL2) higher than the first upper limit.

The invention relates to a functional unit (100) for a brake release device, comprising a recess (111) for receiving a pump assembly (113), an actuating cylinder support (119) for receiving an actuating cylinder arrangement (400), wherein the functional unit (100) is formed as an integral functional block where the actuating cylinder support (119), the recess (111) and a plurality of channels (150, 160, 170, 171, 172, 180, 190) for a hydraulic medium are developed, said channels forming a line arrangement. The invention also relates to a brake release device having such a functional unit.