A spring brake actuator for applying a brake of a vehicle includes a housing containing a diaphragm that separates the housing into first and second chambers. A clutch actuator device is for selectively compressing a compression spring such that the spring brake actuator is operable in a plurality of states including a parking state, driving state, and a braking state.

A sealing assembly for installation on a port of a spring brake actuator includes a plug, a one-way valve and a cap. The plug receives the one-way valve for providing one-way air flow through the orifices and maintaining about two psi in the spring brake chamber at zero stroke. An elastomeric piece is affixed to a first set of segments of the plug for sealing against an inner surface of the port. The cap has arms sized to extend around a third set of segments of the plug and snap onto the plug. A fourth set of segments of the plug elastically deform so the sealing assembly can be installed and removed from the port easily.

A parking brake apparatus is provided for a power unit having air brake parking components and to which a towed unit having air brake parking components can be connected. The parking brake apparatus comprises a controller arranged to monitor a pressure signal indicative of a delivery air pressure applied to the air brake parking components of the towed unit when the towed unit is connected to the power unit. The controller is also arranged to provide a status signal indicative of whether or not a towed unit is connected to the power unit based upon the pressure signal. The controller further enables the status signal to be processed to control application or release of any combination of air brake parking components of the power unit and the towed unit to park or unpark the power unit as well as the towed unit, if connected to the power unit.

A sealing assembly for installation on a port of a spring brake actuator includes a plug, a one-way valve and a cap. The plug receives the one-way valve for providing one-way air flow through the orifices and maintaining about two psi in the spring brake chamber at zero stroke. An elastomeric piece is affixed to a first set of segments of the plug for sealing against an inner surface of the port. The cap has arms sized to extend around a third set of segments of the plug and snap onto the plug. A fourth set of segments of the plug elastically deform so the sealing assembly can be installed and removed from the port easily.

An electro-pneumatic parking brake arrangement includes a shut-off valve and a parking brake module. The parking brake module includes a reservoir connection configured to connect to a compressed air reservoir, a first spring-loaded accumulator connection configured to connect to the shut-off valve, an electro-pneumatic valve unit having at least one electro-pneumatic valve configured to output a spring-loaded brake pressure at the first spring-loaded accumulator connection, and an electronic control unit configured to receive parking brake signals from an electronic parking brake switch and/or a higher-order control unit. The shut-off valve comprises a second spring accumulator connection configured to connect the spring-loaded brakes of the further axle and to shut off the second spring accumulator connection depending on a shut-off signal provided by the parking brake module.

A spring brake actuator for applying a brake of a vehicle includes a housing containing a diaphragm that separates the housing into first and second chambers. A clutch actuator device is for selectively compressing a compression spring such that the spring brake actuator is operable in a plurality of states including a parking state, driving state, and a braking state.

A brake system includes an electromagnetic brake device configured to apply a brake to a rotary shaft when current is not applied to the brake system and release the brake on the rotary shaft when current is applied to the brake system; and a brake release device configured to forcibly release the brake on the rotary shaft when current is not applied to the brake system. The brake release device includes a guide member having a tube shape; a release plate disposed within the guide member and engaged with the armature; and a transfer unit that is configured to move the release plate in a direction in which the rotary shaft extends.

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 actuator has a plurality of actuator housing portions, a parking piston axially displaceable within one of the actuator housing portions, and a service piston axially displaceable independently of the parking piston within another of the actuator housing portions. A brake actuator rod projecting from the other of the actuator housing portions moves outward of that actuator housing portion upon at least one of fluid supply to a first substantially torus-shaped service brake bladder and fluid relief from a second substantially torus-shaped parking brake bladder. The brake actuator rod can be moved inward into the other of the actuator housing portions upon fluid relief from the first substantially torus-shaped service brake bladder, and fluid supply to the second substantially torus-shaped parking brake bladder or both.

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.