Patent ID: 8887877

Claim:
A drum brake, comprising: (a) an automatic shoe clearance adjustment apparatus including (1) a strut which is provided between a pair of facing ends of a pair of brake shoes, said strut having (i) a strut body with adjustment teeth, (ii) a quadrant with adjustment teeth, pivotally mounted on said strut body at one end of said strut body so as to be movable in a longitudinal direction of said strut body, said quadrant has a shoe engagement portion engaging a quadrant engagement portion formed on a shoe web of one brake shoe with a predetermined first gap, so as to be rotatable to automatically adjust a brake shoe clearance when the amount of brake shoe outward movement exceeds a predetermined value, and (iii) a quadrant spring urging said quadrant toward said strut body so that said adjustment teeth of said strut body and quadrant resiliently engage each other; (2) a brake lever which is mounted on the other brake shoe so as to mechanically operate said pair of brake shoes in cooperation with said strut; and (3) a spring which urges said brake lever in a cable releasing direction; (b) a shoe return spring which urges said brake shoes for returning said brake shoes to an original position; and (c) a brake cable which is connected to a free end of said brake lever, wherein a first engagement portion is provided between said brake lever and said strut body and a different second engagement portion is also provided between said brake lever and said strut body so that said brake lever abuts against said strut body at said first engagement position, and then said brake lever departs from said strut body at said second engagement portion with a predetermined second gap that defines said predetermined value in cooperation with said predetermined first gap, when the service brake is not operated, and that said brake lever leaves from said strut body at said first engagement portion, and then said brake lever abuts against said strut body at said second engagement portion, and therefore said strut body can follow said the other brake shoe via said brake lever while automatically adjusting the brake shoe clearance.