Parking brake assembly with wear adjustment for heavy road vehicle disc brake

摘要

In a disc brake (10) having a disc (16) and a brake shoe (82) movable towards and away from a friction surface (86) provided on one face of the disc (16), there is provided a parking brake (22a/22b) having a pushing member (44a/44b) for moving the brake shoe (82) towards and away from the friction surface (86) of the disc (16). The parking brake (22a/22b) further includes a cam (36a/36b) displaceable between a first position in which the cam (36a/36b) forces the pushing member (44a/44b) against a biasing force acting thereon to maintain the brake shoe (82) in friction engagement with the disc (16) and a second position in which the pushing member (44a/44b) is free to move in a direction away from the disc (16) to release the brake shoe (82) from the friction surface (86) of the disc (16). A piston and cylinder arrangement (28) is provided to displace the cam (36a/36b) between its first and second positions.