| 摘要 |
<p>A brake adjuster for adjusting the working clearance of the shoes of an automotive drum brake, the adjuster including three co-axial elements a first rod element (25) having a head portion for engagement with a first brake shoe and a threaded stem portion, an intermediate element (28) in threaded engagement with the first rod element and a second rod element (27) having a head portion for engagement with a second brake shoe and a stem portion slideably connected with the intermediate element (28) and free to rotate relative thereto. A reaction member (30) is mounted on the intermediate element (28) and a ring gear (35) is provided on the intermediate element which is axially located between the second rod element and the reaction member. A leaf spring (31) acts between the second rod element (27) and the reaction member (30) for pushing the second rod element away from the intermediate element (28). This leaf spring carries a bi-metallic pawl (31) which is either formed integrally with the leaf spring or is secured around the spring so that during a normal operation the pawl engages the ring gear (35) to operate the adjuster and at temperatures above a pre-set value the pawl is deflected out of engagement with the ring gear to prevent adjustment.</p> |
