Zero drag disc brake with anti-knock-back device

Abstract

A disc brake caliper assembly is provided that includes a housing having a bore. A piston is arranged within the bore and is movable between normal retracted and knock-back positions. A linkage is adjacent to the piston and is movable between first and second positions with a clearance between the piston and the linkage in the first position. The clearance undesirably permits the piston to move to the knock-back position during severe operating conditions. An actuator, which also may be used as part an electric parking brake, moves the linkage from the first position to the second position to eliminate the clearance when the linkage is moved from the first position to the second position where the linkage abuts the piston. The linkage is connected to the caliper housing by a support. The linkage prevents the piston from moving from the normal retracted position to the knock-back position. In operation, the present invention prevents piston knock-back by sending an adjustment signal from a controller to the actuator at a predetermined interval. The signal commands the actuator to move a linkage from the first to the second position where the linkage abuts the piston. In this manner, the linkage prevents the piston from moving from a normal retracted position to a knock-back position.