A parking valve for manually actuating a spring-loaded parking brake, includes: a housing with a port that can be fluidically connected to a release chamber of a spring-loaded brake cylinder, a port that can be fluidically connected to a brake supply reservoir, and a ventilation port; a slide for manual actuation and which can be moved along a full section between two end positions inside the housing. The slide assumes positions along the full section, in which, as a result of at least one seal, there is no fluidic connection between the port to the release chamber and the ventilation port, and assumes other positions along the full section, in which, as a result of the at least one seal, there is no fluidic connection between the port of the release chamber and the port to the brake supply reservoir. A blocking device acts on the slide during movement at least along a partial section of the full section in at least one direction, with a continuously variable counterforce dependent on the position of the slide on the partial section.

A method operates a braking device for motor vehicles, in particular for utility vehicles. Along a trailer supply line for supplying air to a parking brake of a trailer and/or a trailer control line for supplying air to an operating brake of a trailer, the air pressure is measured by at least one pressure transducer and is transmitted in the form of an electric signal to an electronic control unit of the motor vehicle. In the event of a faulty pressure change response, an open trailer supply line and/or an open trailer control line is detected.

A utility vehicle control device for a parking brake device of a trailer vehicle includes a pneumatic supply connection, a control connection for controlling a spring brake cylinder, a directly manually actuatable parking valve, a first connection line and a control valve for controlling the parking valve. The parking valve is arranged in the first connection line, and wherein as a result of the parking valve, the supply connection and the control connection can be connected via the first connection line. A control line branches from the first connection line. The control line is connected to a first pneumatic control input of the control valve, wherein the control valve has a second pneumatic control input. In the event of an unexpected reduction in operating pressure in the first connection line and/or in the control line, the control valve can be controlled by the first or second control input of the control valve such that a switching state of the parking valve can be pneumatically controlled by the control valve independently of an operating state of the supply connection, whereby the control connection is ventilated by the parking valve.

Please substitute the new Abstract submitted herewith for the original Abstract: An electropneumatic parking brake control device controls a parking brake including at least one spring brake actuator. The control device includes a relay valve with a control chamber and a vent. The control chamber can be connected to the vent via at least one second throttle element and/or at least one third throttle element depending on the position of the relay piston.

A control valve for applying a spring-loaded brake pressure to spring-loaded parts of a rear-axle wheel brake is pneumatically activated as a function of a parking-brake braking demand and a service-brake braking demand. A first control chamber is connected via a first control piston to a control arrangement in the control valve. During an adjustment of the first control chamber via the service-brake control pressure, the spring-loaded brake pressure at the working output is a function of the service-brake control pressure or of the parking-brake control pressure. The first control piston is connected to a third control chamber, wherein the pressure in the first control chamber acts on the first control piston in one direction, and the pressure in the third control chamber acts on the first control piston in the opposite direction. The first control chamber is selectively connectable to the third control chamber via a switchable bypass valve.

A pneumatic braking device for a utility vehicle includes at least one pneumatically controllable spring accumulator for a parking brake of the utility vehicle with an electronic parking brake device. The electronic parking brake device has at least one electronic control unit, at least one first bistable valve unit, at least one second bistable valve unit, at least one 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 of the traction vehicle, the parking brake of the trailer can be activated, and a traction vehicle protection valve.

An electropneumatic parking brake module includes a supply port configured to connect a compressed air supply, a spring brake actuator port configured to connect at least one spring brake cylinder, and a trailer control port, an inlet-outlet valve unit configured to control a spring brake pressure, and an electropneumatic pilot control unit configured to control at least one control pressure at the inlet-outlet valve unit and configured to perform a trailer control position function. The electropneumatic pilot control unit includes a 3/3-way valve that has a first switching position in which the at least one control pressure is controlled, a second switching position in which the trailer control position function is carried out, and a third switching position in which the inlet-outlet valve unit and the trailer control port are connected to a vent.

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 backup system for an electronic parking brake, EPB, of a commercial vehicle ensures a safe state even during electric power failure of a power supply unit of the EPB. The backup system includes a detection unit for detecting the power failure, a storage device for storing sufficient electric power to perform a switch into the safe state, a boost circuit configured to charge the storage device during standstill of the vehicle and to discharge the storage device during motion of the vehicle, and a switch device configured to supply the electric power of the storage device to the EPB if the power failure is detected by the detection unit.

A method is for operating a parking brake system with a spring-loaded brake and a control module in a motor vehicle or trailer. The control module is connected to a parking brake circuit. The method includes supplying the parking brake circuit with reservoir pressure. The method further includes applying spring-loaded accumulator holding pressure to the spring-loaded brake cylinders in order to have the spring-loaded brake assume a release position, wherein the spring-loaded accumulator holding pressure is less than the reservoir pressure in the parking brake circuit.