| 摘要 |
<p>A drum brake assembly (22) with an hydraulic service brake function of leading/trailing type and a parking or emergency brake function of the duo-servo type. A lever member (40) is pivotally mounted (35, 39, 44, 46, 48) on one (27) of a pair of brake shoes (27, 28). The lever is contacted at one end by a first composite strut (60) which includes an automatic brake shoe clearance adjusting mechanism and at the other end by a second composite strut (70) which includes a parking brake applying mechanism (75, 76, 77). The other ends of struts (60) and (70) act against the other brake shoe (28) so that when the service brake function is released and the parking brake function is operational, any tendency for the associated brake drum (20) to rotate causes one of the brake shoes to contact a rotation preventing stop (56) and the other brake shoe to apply an additional servo force to said one brake shoe via the lever (40) and first strut (60).</p> |
