An automatic clearance compensator for a drum brake

摘要

An automatic shoe clearance adjustment apparatus having a ratchet wheel (124b) and a driving member (127) comprising a pawl section (127f) making a ratchet engagement with the ratchet wheel (124b) and an arcuate leaf spring section (127e) developing a resilient force for adjusting the automatic shoe clearance adjustment apparatus. The leaf spring section (127e) is made of bi-metal. When the temperature of the leaf spring section (127e) exceeds the predetermined degree, the arcuate leaf spring section (127e) thermo-deflects so as to weaken the resilient force, thereby the automatic shoe clearance adjusting operation is suspended. <IMAGE>