A parking brake mechanism

A parking brake mechanism for an air actuated disc brake, the mechanism comprising an air chamber separated into a non-pressurised section and a pressurised section; a resilient device located in the non-pressurised section and movable along an axis to adopt a retracted parking brake-off position and a deployed parking brake-on position, and being biased into the deployed position; a latching device arranged to selectively retain the resilient device in the retracted position; an actuator arranged to selectively disengage the latching device to permit the parking brake mechanism to be applied; the mechanism being configured to introduce pressurised air into the pressurised section to return the resilient device to the retracted position