Automatic adjuster for duo-servo internal shoe drum brakes

摘要

A duo-servo brake comprising a pair of arcuate brake shoes within a brake drum, automatic operating means being located between opposed shoe ends for adjusting the clearance between shoes and drum characterized by the provision of a pair of pivotable adjuster plates having pawls each pawl being engageable with a ratchet toothed adjuster wheel whereby when the shoes are moved by drag from the drum upon brake actuation the automatically operated means enables pivotable movement of one or other adjuster plate to cause its pawl to ride over a ratchet wheel tooth, springs subsequently causing the wheel to rotate a screw-threaded means to automatically adjust the clearance between one or other of the shoes and the drum.