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 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 brake actuator for a vehicle includes a cylinder housing having a surface and a wall opening provided in this surface, a brake chamber having a variable volume and a dust plug releasably arranged in the wall opening. The dust plug includes a flexible circumferential lip configured for abutting against the surface of the cylinder housing in a sealing state, and for being flexed away from the surface in a flexed state. The lip is configured to assume the flexed state in response to a positive pressure inside the brake chamber, and to assume the sealing state in response to negative pressure inside the brake chamber. A core section is arranged adjacent to the lip and the core section is configured for extending through the wall opening of the cylinder housing. A pressure compensation flow path is defined between the lip and the brake chamber.

A piston tube assembly (17) for a spring brake actuator (1) includes a first tubular body (35) having a contoured inside surface profile (55) for non- rotationally guiding a running nut (21) of a mechanical release mechanism (19, 21), and an internal breather valve (41) mounted to the piston tube assembly (17) for allowing fluid transport into and out of the piston tube assembly and any volume in fluid communication therewith. The piston tube assembly (17) includes a second tubular body (37) that is of a different material than the first tubular body (35), which encloses the first tubular body (35) and mechanically supports the first tubular body (35), and the internal breather valve (41) is mounted to the first tubular body (35).

The disclosure relates to a pneumatic braking system comprising a service brake actuator; an electro-pneumatic modulator unit for receiving an air control pressure representative of a driver's braking request; delivering, by a regulation unit, a modulated air pressure to a service brake chamber; a parking brake actuator; a parking brake unit for delivering a second air pressure to a parking brake pneumatic chamber; and an isolation device for when the isolation device is electrically energized, preventing the delivery of the air control pressure to the regulation unit, and for when the isolation device is not electrically energized, allowing the delivery of air control pressure to the regulation unit when the second air pressure is higher than a threshold, and preventing the delivery of air control pressure to the regulation unit when the second air pressure is lower than the threshold.

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 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.

An electromechanical brake apparatus includes a housing supporting an inboard brake pad and an oppositely facing outboard brake pad for selective frictional contact with a rotor interposed longitudinally therebetween. An adjuster ramp assembly indirectly receives torque from the motor unit. A spindle is provided for selectively moving the inboard brake pad longitudinally. The spindle is operatively connected with the adjuster ramp assembly to indirectly receive torque from the motor unit therethrough. A leading ramp assembly is configured to transmit applied torque from the motor unit to the adjuster ramp assembly via at least one ramp ball longitudinally interposed therebetween. A predetermined amount and direction of torque is applied to each of the adjuster ramp assembly and the leading ramp assembly to assist with a selected one of (1) service brake application and (2) service brake release functions. The electromechanical brake apparatus is operative, at different times, for both functions.

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.