A safety device used by workers climbing ladders fixed to high structures consists of a ra...

A safety device used by workers climbing ladders fixed to high structures consists of a rail attached to the ladder and a sleeve that can slide on the flange of the rail. A chain connects the worker's belt to the end of an eccentric cam that can be rotated about an axle attached to the sleeve at C. Determine the smallest allowable common value of the coefficient of static friction between the flange of the rail, the pins at A and B. and the eccentric cam if the sleeve is not to slide down when the chain is pulled vertically downward.