A spring brake actuator has a combined housing including a first housing, a second housing, and connection part connecting the first housing and the second housing. Gas inlet ports are disposed along the circumference of the combined housing in a gas inlet port section. A mechanical connection section is disposed in the same axial space as the gas inlet portion section. A bayonet connection is arranged in the mechanical connection section, with gas inlet ports disposed between the bayonet elements. Port connectors may extend through recesses or holes and be threaded into the gas inlet ports, and which may block the bayonet connection and block relative rotation between the first and second housings. The connection part may include a ring shaped protrusion form fit with a protruding of the second housing, with the bayonet elements disposed at the opposite end of the connection part engaged with the first housing.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

A brake cylinder with a cylinder body having a first flange extending radially therefrom to form a radial edge with a bevel and a non-pressure head having a second flange extending radially therefrom, wherein the second flange is spaced apart from the first flange to define a first gap and includes an angled portion that extends over the bevel of the first flange to define a second gap in communication with the first gap. The two flanges form a gap in communication with the interior of the brake cylinder that extends outwardly to a V-shaped gap between the bevel of the first flange and the angled portion of the second flange to define a brake cylinder vent. The vent may be limited to four predetermined locations spaced equidistantly about the brake cylinder or the vent may extend circumferentially about the brake cylinder.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

A spring brake actuator is for braking a wheel of a vehicle. The spring brake actuator has an axially elongated housing having a parking brake chamber and a service brake chamber; a main compression spring in the parking brake chamber; a flexible diaphragm in the parking brake chamber; and a pressure plate in the parking brake chamber, the pressure plate located axially between the main compression spring and the flexible diaphragm. The flexible diaphragm has a contoured portion that inhibits radial shifting of the pressure plate with respect to the flexible diaphragm.

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 interface between an adapter push rod and a parking brake diaphragm seal includes an axial projection at one end of the push rod, a thread extending axially between a free end of the projection and a remainder of the push rod, and a washer having an approximately conical wall extending radially inwardly from an outer circumference of the washer towards a central mounting connection having a radial flange. A nut is threaded over the free end of the projection, and an opening in a hardened element is aligned axially with the projection to receive the projection. A circumferential groove defined in a side of the radial flange forms a boundary between the approximately conical wall and a remainder of the washer, and a portion of the diaphragm seal is pressed by the nut and the hardened element into the circumferential groove to produce a sealing bead.

A spring brake actuator (1) for a vehicle, in particular a parking or emergency brake actuator, for use in a commercial vehicle, includes a cylinder housing (2) having a cylinder housing base (5) and a spring seat (7) on the base, a spring brake piston (9) located in the cylinder housing (5) for applying a braking force, and a compression spring (11) arranged between the spring seat (7) and the spring brake piston (9). The cylinder housing (2) is divided into a spring chamber (12) and a pressure chamber (14), the compression spring (11) being arranged in the spring chamber (12) and the pressure chamber (14) being supplied with pressurized fluid. An elastically deformable diaphragm (16) is sealingly mounted to the cylinder housing (2), with an inner periphery (18) sealingly mounted to the spring brake piston (9) to fluid-tightly isolate the pressure chamber (14) from the spring chamber (12).

A brake actuator assembly including a pressure plate presenting an opening, a push rod that is coupled to the pressure plate, a diaphragm that is coupled to the pressure plate, and a retainer that engages the push rod. The push rod has an outer surface and at least one protrusion extending outward from the outer surface. The retainer engages the protrusion such that at least a portion of the diaphragm is positioned between the pressure plate and the retainer.

A brake assembly including an operating shaft, a yoke, and a rotating element. The rotating element bearing may be positioned between a convex bearing surface of the operating shaft and a concave bearing surface of the yoke such that the rotating element bearing may be configured to move relative to the operating shaft and relative to the yoke during actuation of the brake.