Vehicle mechanically operated disc hand-brake - has brake caliper locked for mechanical operation by sprung wedge if system air pressure falls

摘要

The hand brake installation for disc brakes has a hydraulically activated fixture piston operating via a pressure piece on the piston of the brake. A wedge locks the fixture piston in its fixed position when there is a drop in pressure. The wedge is withdrawable under spring force into a space made available by the fixture piston in its fixed position, and has a wedge surface which, in the stop position, locates against a wedge surface on an axially extending part of the fixture piston. The fixture piston is connected with a draw bar extending out of the hand brake fixture cylinder.