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.

An electropneumatic valve assembly for actuating a parking brake function of an electropneumatic brake system of a commercial vehicle has a parking brake valve unit which receives supply pressure from a supply pressure path and outputs a parking brake pressure at least at one spring brake port in dependence on an electronic parking brake signal. A pneumatically switchable safety valve connects the supply pressure path to at least a first compressed air supply and in a supply position connects the compressed air supply to the supply pressure path and in an air release position releases air from the supply pressure path. A pneumatic safety valve control port of the safety valve is connected to the at least one compressed air supply. The safety valve switches into the supply position if the supply pressure provided by the at least a first compressed air supply exceeds a threshold value.

The invention concerns an electronic parking brake system (2), comprising an air supply (4), a check valve (6), connected to the air supply, an electro-pneumatic control unit (8), at least one park brake actuator (10), a relay valve (12), comprising a first port (12a) connected to the check valve, a second port (12b) connected to the electro-pneumatic control unit, a third port (12c) connected to the park brake actuator and a fourth port (12d) which is in communication with the atmosphere, and an electrically actuated valve (14), which is controlled by the electro-pneumatic control unit (8) and which includes a first orifice (14a) connected to a compressed air line (16) extending between the check valve and the air supply, a second orifice (14b), a third orifice (14c) connected to the electro-pneumatic control unit (8), and preferably a vent orifice. The second orifice (14b) is connected to another compressed air line (18) extending between the check valve (6) and the first port (12a) of the relay valve (12).

A valve-arrangement is operable to switch between a bistable-valve (BV) behavior and a relay-valve (RV) behavior to control a parking-brake, and includes a housing with a supply-pressure-inlet (SPI), a service brake-control-inlet (SBCI) to provide a control-pressure, a pressure-outlet, and an exhaust-port, and includes a first-piston and a second-piston both movable along a same direction in the housing to define a first-chamber communicating with the SBCI, a second-chamber between the first-piston and the second-piston, and third chamber communicating with the pressure-outlet and with a controllable connection to the SPI, in which upon the control-pressure the second-piston moves with the first-piston to connect the pressure-outlet with the exhaust-port or with the SPI. The valve arrangement includes a throttle unit adapted, depending on the control-pressure, to connect the second-chamber with the third-chamber to enable the BV behavior or disconnect the second-chamber from the third-chamber to enable the RV behavior.

An electric-parking-brake for a utility-vehicle, including: a feed-line for brake-pressure air; a discharge-line for brake-pressure air for a pneumatic-brake-device; a first-valve and a second-valve, each being switchable between a stable-state and an activated-state in response to electrical control-signals; and a valve-device which is connected between the feed-line and the discharge-line and exhibits a control-input, the valve device being switchable between a stable-state and an activated-state in response to control signals at the control-input, the feed-line being connected to the discharge-line in the activated-state, in which the first-valve in the stable-state or in the activated-state connects the control-input of the valve-device to the discharge-line, to retain a current-state of the valve-device when the brake-pressure air is applied to the discharge-line, and in the activated or stable state connects the control-input to the second-valve. Also described are an electric parking brake system, a utility vehicle, and a related method.

A spring brake actuator has a service brake with a service brake housing and a service brake working chamber located in the service brake housing. The service brake working chamber is confined by a diaphragm. A service brake piston movable along an actuator-longitudinal axis and abuts the diaphragm, which applies a brake force onto the service brake piston. A spring between the service brake piston and the service brake housing pushes the service brake piston against the direction of the brake force. A modulator valve unit communicates with the service brake working chamber and is configured to regulate the inlet and outlet of fluid into and out of the service brake working chamber. The modulator valve unit is integrated into the spring brake actuator and includes a controllable inlet valve communicating with the service brake working chamber and a controllable outlet valve communicating with the service brake working chamber.

A relay valve (10) for a pneumatic valve unit (14), for example for a braking system of a utility vehicle, has a first assembly component (18) and a second assembly component (20). A hollow cylindrical guide portion (28) of a piston (24) of the relay valve (10) is received, in an axially guided manner, in the first assembly component (18). The second assembly component (20) includes additional valve components and the venting region of the relay valve (10). At least the first assembly component (18) and the second assembly component (20), when assembled, form a preassembly unit (26) first assembly component (18) and are joined by a bayonet connection (30). The preassembly unit (26) is inserted into a housing (12) of the valve unit (14), The interior of the housing is delimited by a cup-shaped inner wall (32), and the preassembled unit is fastened therein.

A pneumatic brake pedal module for a brake-by-wire brake system of a vehicle is disclosed. The brake pedal module includes a pivotably mounted brake pedal and a damping unit. The damping unit is mechanically coupled to the brake pedal to generate a resistance when the brake pedal is actuated. The damping unit comprises a housing and a piston, which is mounted movably in the housing and divides an internal space of the housing into a pressure chamber and a vacuum chamber. The pressure chamber and the vacuum chamber are connected to one another in terms of flow. The piston has on its running surface an encircling annular space in which a ring seal is accommodated in an axially movable manner. The ring seal is located at least in a flow path between the pressure chamber and the vacuum chamber and forms a restrictor in the at least one flow path, which restrictor frees different flow cross sections in the at least one flow path depending on the axial direction of movement, and damps the movement of the piston with differing degrees of strength depending on a direction of movement of the piston.

A valve assembly is provided. The valve assembly includes a valve body defining a bore. The valve assembly further includes a pull rod disposed in the bore and defining a bolt cavity. The pull rod is moveable between a first pull rod position and a second pull rod position. The valve assembly further includes a bolt disposed in the bolt cavity and moveable with respect to the pull rod between a first bolt position and a second bolt position. The valve assembly further includes a spool disposed in the bore. The spool is operatively coupled to the pull rod to move between an energized position and a neutral position.

An electric-parking-brake for a utility-vehicle, including: a feed-line for brake-pressure air; a discharge-line for brake-pressure air for a pneumatic-brake-device; a first-valve and a second-valve, each being switchable between a stable-state and an activated-state in response to electrical control-signals; and a valve-device which is connected between the feed-line and the discharge-line and exhibits a control-input, the valve device being switchable between a stable-state and an activated-state in response to control signals at the control-input, the feed-line being connected to the discharge-line in the activated-state, in which the first-valve in the stable-state or in the activated-state connects the control-input of the valve-device to the discharge-line, to retain a current-state of the valve-device when the brake-pressure air is applied to the discharge-line, and in the activated or stable state connects the control-input to the second-valve. Also described are an electric parking brake system, a utility vehicle, and a related method.