Caliper-type disc brake with stepped rotor

摘要

A disc brake for the wheel of a motor vehicle includes a rotor mounted to the wheel, and a caliper straddling the rotor and supporting a brake pad on either side thereof. In order to accommodate packaging constraints within the wheel's rim, the outboard pad and the rotor's outboard friction surface are both positioned radially inwardly of the inboard pad and inboard rotor friction surface. A hydraulic piston located in the inboard portion of the caliper first urges the inboard pad along the piston's longitudinal axis into initial engagement with the rotor's inboard friction surface, whereupon the piston acts through the caliper's bridge and finger area to urge the outboard pad into engagement with the rotor's outboard friction surface. The effective radius of each pad is less than the radial offset of the piston's longitudinal axis from the rotational axis of the wheel and rotor so as to reduce the bending moment applied to the rotor upon braking. <IMAGE>