| 摘要 |
<p>The automatic adjuster (5) for the drum brake (6) comprises first and second oppositely disposed end members (30, 40) each having slots (32, 42) for receiving nonrotatably brake shoe webs (10, 14) and a parking lever (22). The first end member (30) includes a radially expanded end portion (34) defining an interior cavity (36) with a conically shaped surface (38). The second end member (40) is connected with a rotatable starwheel flange (44) of a longitudinally extended shaft (48) having therein a threaded opening (49), the starwheel flange (44) immobilized by a return spring (16) of the brake (6). An intermediate member (50) has at one end a threaded shaft (52) which is received threadedly within the threaded opening (49) of the shaft (48) and at the other end a conically shaped member (54) which engages the conically shaped surface (38) of the first end member (30). Located rotatably about the intermediate member (50) and adjacent the conically shaped member (54) is a bearing member (60) having a radially extending surface (69) located within the interior cavity (36) and disposed a predetermined distance or running clearance (X) from a radial surface (58) of the conically shaped member (54), and an exterior radially extending flange (62) having one radial surface (66) engaging a radial surface (39) of the first end member (30) and an opposite radial surface (7) of the flange (62) engaged by a spring (70) which extends to engage the starwheel flange (44). When the drum brake shoes (8, 12) are activated and the running clearance (X) between the conically shaped member (54) and bearing member (60) is exceeded, the intermediate member (50) moves the bearing member (60) so that the bearing member flange (62) disengages the radial surface (39) of the first end member (30) and the biasing force of the spring (70) causes the intermediate member (50) to rotate relative to the shaft (48) and second end member (40) and effect expansion of the automatic adjuster (5).</p> |
