IMPROVEMENTS IN AUTOMATIC SLACK ADJUSTERS FOR VEHICLE SHOE-DRUM BRAKES

摘要

An automatic slack adjuster comprises a pair of thrust assemblies. Each thrust assembly acts between a cam and a respective shoe-end and is guided to slide axially in a bore in a housing. Each thrust assembly comprises a nut which engages with, and is held against rotation with respect to, a respective shoe-end, and a screw-threaded tappet having a piston part which slides in the bore, and an integral threaded stem of reduced diameter which is screwed through the nut. The piston parts are both provided with gear teeth to enable them to be rotated together by the engagement of a crown wheel, or a pair of pinions carried by opposite ends of a transverse shaft which is rotatable in a bore normal to a bore in which the cam shaft carrying the cam is rotatable.