Slack adjuster

A rotary slack adjuster for use in a brake system of a vehicle for compensating for wear in brake friction lining, said adjuster including an input arm for connection to an actuating piston of a brake actuator, an output arm for connection to an output rod, and a rotatable member, coupling means being provided for coupling said input arm, said output arm and said rotatable member together for mutual rotation during brake actuation in each of a first direction and a second opposite direction, said rotatable member being confined to rotate between end limits in each of said first and second directions, wherein said coupling means permits said input arm and said output arm to further mutually rotate in said first direction relative to rotatable member upon said rotatable member rotating to said end limit in said first direction, and said coupling means being arranged so that upon relative rotation between said input and output arms and said rotatable member exceeding a predetermined amount, said input and output arms are restrained against return rotation relative to said rotatable member and are thus repositioned relative to said rotatable member, and wherein said coupling means permits said input arm to further rotate in said second direction relative to said output arm and said rotatable member upon said rotatable member rotating to said end limit in said second direction at which end limit said coupling means prevents further rotation in said second direction of said output arm, and said coupling means being arranged so that upon relative rotation between said input arm and each of said output arm and said rotatable member exceeding a predetermined amount, said input arm is restrained against return rotational movement relative to said output arm and said rotatable member, and said input arm is thus repositioned relative to said output arm and said rotatable member, wherein in use, a brake system including said slack adjuster is arranged so that the respective repositioning of said input and output arms results in a shift in the brake friction lining toward the braking surface, so compensating for wear in said friction lining, said slack adjuster further including a bracket for connecting said slack adjuster to a support, said bracket including first and second spaced apart members between which each of said input and output arms and said rotatable member are positioned for rotation, biasing means being provided to bias said input and output arms and said rotatable member together, but permitting separation thereof to facilitate relative rotation between said output arm and said rotatable member and between said input arm and said output arm as necessary.