A spring brake system includes a service brake chamber, a spring brake chamber adjacent to the service brake chamber, a wall separating the service brake chamber from the spring brake chamber, a shaft, and a device. The shaft extends from the service brake chamber into the spring brake chamber through an opening in the wall. The device is disposed along the shaft through the wall, the device being configured to: i) allow air to flow from the service chamber into the spring brake chamber, and ii) prevent air from flowing from the spring brake chamber into the service chamber. The air is within a range that is sufficient to reduce a pressure differential between the service brake chamber and the spring brake chamber. The air is also within a range that is sufficient to generate an anti-compounding effect.

A spring brake system includes a service brake chamber, a spring brake chamber adjacent to the service brake chamber, a wall separating the service brake chamber from the spring brake chamber, a shaft, and a device. The shaft extends from the service brake chamber into the spring brake chamber through an opening in the wall. The device is disposed along the shaft through the wall, the device being configured to: i) allow air to flow from the service chamber into the spring brake chamber, and ii) prevent air from flowing from the spring brake chamber into the service chamber. The air is within a range that is sufficient to reduce a pressure differential between the service brake chamber and the spring brake chamber. The air is also within a range that is sufficient to generate an anti-compounding effect.

A piston-cylinder unit includes a piston delimiting at least one working chamber, in which a first seal for sealing at least one first working chamber is arranged either between the piston and cylinder or between a plunger connected to the piston and the cylinder. A second seal is arranged between the first seal and the first working chamber, and the piston-cylinder unit further includes a first channel arranged in the wall of the cylinder or in the piston, which joins the first seal and the second seal in the inner chamber of the cylinder. The first channel and/or a hydraulic line connected thereto may have a throttle device and/or a valve device. An electronic control and regulating device may have a diagnosis or monitoring function for a possible defect or failure of a seal. Multiple hydraulic devices may have such piston-cylinder units and respective control and such regulating devices.

A piston-cylinder unit includes a piston delimiting at least one working chamber, in which a first seal for sealing at least one first working chamber is arranged either between the piston and cylinder or between a plunger connected to the piston and the cylinder. A second seal is arranged between the first seal and the first working chamber, and the piston-cylinder unit further includes a first channel arranged in the wall of the cylinder or in the piston, which joins the first seal and the second seal in the inner chamber of the cylinder. The first channel and/or a hydraulic line connected thereto may have a throttle device and/or a valve device. An electronic control and regulating device may have a diagnosis or monitoring function for a possible defect or failure of a seal. Multiple hydraulic devices may have such piston-cylinder units and respective control and such regulating devices.

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.

A noise damper for a compressed-air system, for a brake system of a utility vehicle, including: a housing having an inlet channel for a compressed-air stream and with a chamber for accommodating sound-damping material, in which the inlet channel and the chamber are separated, perpendicularly with respect to the compressed-air stream, by a separating plate which is closed in a central region and which, in an outer peripheral region of the compressed-air stream, has multiple openings for introducing the compressed air directly into the chamber. Also described are a related pneumatic brake system and method.

A noise damper for a compressed-air system, for a brake system of a utility vehicle, including: a housing having an inlet channel for a compressed-air stream and with a chamber for accommodating sound-damping material, in which the inlet channel and the chamber are separated, perpendicularly with respect to the compressed-air stream, by a separating plate which is closed in a central region and which, in an outer peripheral region of the compressed-air stream, has multiple openings for introducing the compressed air directly into the chamber. Also described are a related pneumatic brake system and method.

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 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 retarding control assembly for a brake valve may include a bleed line configured for arrangement between a spring chamber of a brake command assembly and a tank line. The bleed line may include a check valve configured to allow fluid flow from the spring chamber to the tank and a check valve bypass configured to allow fluid flow from the tank line to the spring chamber passed the check valve and defining a restricted pathway.