The present invention relates to an electronic parking brake device for a vehicle, in particular a utility vehicle. As a function of at least one operating state of a towing vehicle parking brake supply line and/or a trailer parking brake supply line, a towing vehicle parking brake control valve is activatable by means of a control unit in such a way that a towing vehicle parking brake supply line can be deaerated or aerated by the towing vehicle parking brake control valve. By manually actuating a trailer parking brake control element, a trailer parking brake control valve is activatable by means of the control unit in such a way that a trailer parking brake supply line can be deaerated or aerated by the trailer parking brake control valve. The present invention also relates to a method for operating the above electronic parking brake device for a vehicle.

An electropneumatic parking-brake valve unit for an electronically controlled pneumatic brake system has a first supply connection to a compressed air source. A spring brake connection connects to a spring brake cylinder of a vehicle. A parking-brake valve arrangement has a bistable valve switchable between switching states wherein a spring brake pressure can be controllable in dependence upon the switching state. A pneumatically switchable holding valve has a holding-valve connection for a first control pressure and the holding valve is connected between the first supply connection and the bistable valve. The holding valve is under a spring load into a first switching position wherein the bistable valve is connected to a deaerator. The bistable valve switches into a second switching position when the first control pressure exceeds a first threshold value. The bistable valve is connected to the first supply connection.

An electropneumatic brake system for a utility vehicle includes a front first brake cylinder and a front second brake cylinder on a front axle, the front first brake cylinder and the front second brake cylinder being configured to brake respective first and second front vehicle wheels. The system also includes a rear first brake cylinder and a rear second brake cylinder on a rear axle, the rear first brake cylinder and the rear second brake cylinder being configured to brake respective first and second rear vehicle wheels. The system additionally includes a central brake control device configured to output brake control signals for pneumatic pressurization of the front first and second brake cylinders and the rear first and second brake cylinders, and further includes two front wheel revolution rate sensors and two rear wheel revolution rate sensors configured to sense respective wheel revolution rates.

An emergency brake device for a rail vehicle includes a compressed-air-brake system, wherein a braking process can be initiated by lowering the air pressure in a main air conduit and which includes an exclusively electric connection to a passenger emergency brake.

A valve arrangement for use in a parking brake system of a commercial vehicle or trailer, includes a differential piston having a first section and a second section, wherein the second section has a smaller diameter compared to the first section, and wherein there is a fluidic connection between the first section and the second section. The arrangement includes a housing with a bore, in which the differential piston is adapted to move. The bore has at least two sections, wherein the first section corresponds to the diameter of the first section of the differential piston, and the second section corresponds to the diameter of the second section of the differential piston, and wherein a step is formed between the first section and second section of the bore. A first passage and a second passage are arranged and axially spaced in the bore, and a third passage is arranged in or next to the second section of the bore. When the differential piston is in a first end position, the second section of the differential piston rests against the step, and a connection of the first passage and the second passage within the bore is provided. When the differential piston is in a second end position, a connection of the first passage and the second passage within the bore is blocked.

A brake system for a vehicle includes a first axle pressure modulator (APM) for service-brake-chambers for a first vehicle-axle, a second axle pressure modulator for spring-brake-cylinders for a second vehicle-axle, the second APM being connected to an electronic-brake-control-unit, which is configured to issue a first electric-control-signal for controlling the first APM and a second electric-control-signal for controlling the second APM, an intelligent foot brake module, which is configured to issue a first pneumatic-control-signal for controlling the first APM and a second pneumatic-control-signal for controlling the second APM, an electronic parking brake controller, which is configured to issue a second pneumatic parking brake signal for controlling the spring-brake-cylinders, and a pressure control valve, which is configured to convert the second pneumatic parking brake signal into a first pneumatic parking brake signal for controlling the first APM.

An electro-pneumatic hand brake system is for a vehicle with spring-loaded brakes. The system includes a pneumatic relay valve, a bistable solenoid valve for controlling the relay valve and a control unit for controlling the bistable solenoid valve. An outlet of the relay valve is connected to ports for the spring-loaded brakes. An inlet of the bistable solenoid valve is provided for connecting to a line carrying ventilation pressure. A self-retaining switching valve with a control input is provided before the inlet of the bistable solenoid valve. The self-retaining switching valve can be moved against the force of a restoring element from a blocking position into a flow-through position when there is sufficient pressure at its control input. An outlet of the self-retaining switching valve is connected to the inlet of the bistable solenoid valve.

A method for emergency engagement of a holding brake of a vehicle having an electropneumatic brake system. The electropneumatic brake system includes a service brake system with a service brake and a holding brake system with the holding brake. The holding brake system has spring brake cylinders. The service brake system includes a service brake control unit. The electropneumatic braking system includes at least one brake circuit for the service brake and the holding brake. The service and holding brakes may be in separate brake circuits. The spring brake cylinders can be vented when a supply pressure in at least one brake circuit for the service brake decreases. The method includes reducing, via the service brake control unit, the supply pressure in at least one brake circuit for the service brake under a program control in defined conditions.

A vehicle braking system comprising a spring brake actuator having a spring brake chamber, a spring brake control assembly and an immobiliser valve which is movable between brake release position in which the spring brake control assembly is operable to cause the flow of pressurised fluid into the spring brake chamber or to vent the spring brake chamber to a low pressure region, and an immobilise position in which the spring brake control assembly is operable to connect the spring brake chamber to a low pressure region but cannot be operated to cause the flow of pressurised fluid into the spring brake chamber.

A system for electrically controlling air brakes on a trailer having an electrically actuated valve for releasing pressurized air at a controlled rate. The trailer is connectable to a standard electrical connector on a towing vehicle that provides a proportional braking signal. The proportional signal is sent to a controller that actuates the electrically actuated valve. When the controller receives the proportional braking signal from the towing vehicle representing no braking force, the controller actuates the electrically actuated valve to produce no air pressure to the air brake. When the controller receives the proportional braking signal from the towing vehicle representing full braking force, the controller actuates the electrically actuated valve to provide air to the air brake corresponding to full braking force of the air brakes.