| 摘要 |
<p>A servo drum brake adjustment mechanism automatically adjusts the brake shoes 14 for wear of the friction pads 16 and drum surface 11. The mechanism comprises a screw-thread adjustment link 20 activated by movement of a pawl finger 55 upon a star wheel 25. The pawl finger is activated by a wire-like push rod 50 and tension link 27. Upon a predetermined circumferential movement of the primary brake shoe 14A relative to the push rod 50, the latter moves over the star wheel 25 so as, on brake release, to effect rotation of the star wheel 25 and adjustment of the brake shoe assemblies 14. In further embodiments, the tension link is replaced by a hook (90, Fig. 10) forming part of a return spring, and by a ramp (98, Fig. 8) on the primary brake shoe. <IMAGE></p> |
