Spot-type automotive disc brake with parking brake function

摘要

A spot-type automotive disc brake 10 provides parking brake and primary (or service) brake functions based on the same pair of friction elements 16, 18 and comprises a sliding disc 12, a fixed caliper 48 having fixed and actuated friction elements 18, 16, and a primary actuator 26 and a parking actuator 28 which actuators act independently on friction element 16. The primary actuator comprises a piston and cylinder arrangement 58 and the parking actuator comprises a bifurcated lever 72 pivotally mounted on the caliper and straddling the piston and cylinder arrangement. In an alternative embodiment, a lever engages friction element 16 at a position between two piston and cylinder arrangements. The piston(s) and lever act completely independently yet symmetrically on friction element 16 without any common thrust-transmitting parts, whereby the asymmetry and complexity and consequential unreliability and high cost and duplication of mechanisms of prior proposals is avoided. Wear adjustment means (90, Fig. 6 or 106, Fig. 7) may be provided.