Disc brake and adjusting device therefor

Claim 1

In a disc brake: a rotor having a pair of friction faces; a pair of friction elements, one of said friction elements being disposed adjacent each of said friction faces; a fixed support; a caliper slidably mounted on said fixed support and straddling said rotor to engage each of said friction elements to urge the latter into braking engagement with their corresponding friction faces upon actuation of the caliper when a brake application is effected; said caliper including a housing defining a bore therewithin, a piston slidably mounted in said bore, means for communicating fluid pressure into said bore when a brake application is effected to urge said piston toward the rotor to thereby actuate said caliper; adjuster means carried in said bore to engage said piston upon retraction of the latter when the brake is released to limit retraction of the piston to a predetermined amount, means carried by said piston and normally separated from operative engagement with said adjuster means by a predetermined distance, said means carried by said piston urging said adjuster means toward said rotor after movement of the piston toward the rotor in excess of the predetermined distance, and compressible resilient means disposed between the adjuster means and the means carried by the piston, said resilient means being compressible in response to the fluid pressure level in said bore to thereby increase the predetermined distance through which said piston must travel to bring the means carried by said piston into operative engagement with said adjuster means.