| 摘要 |
<p>A drum brake has an adjuster comprising a lever member (24) and pawl member (32) mounted on one brake shoe (12) having mutually engaging toothed surfaces (26, 30), the pawl member (32) being urged against the lever member (24) by a spring (34). The lever member (24) is movable by a strut attached to the other brake shoe (14) to operate the adjuster. A locking element comprising a locking member (40) is operated via a lever (44) by a bimetallic strip (46). When the shoe (12) heats up the bimetallic strip causes the locking element (40) to move so that an engagement surface (42) thereon the pawl (32) at any point along the engagement surface (42) to lock it against rotation and prevent adjustment.</p> |
