| 摘要 |
1,032,349. Automatic brake adjustment. BENDIX CORPORATION. May 11, 1964 [May 15, 1963], No. 19556/64. Heading F2E. A brake has a pair of shoes 12, 14 connected at one end to an actuator 16 and carried at the other on an anchorage 26 on a fixed support 10 and includes a screw-and-nut adjustment device operated by a linkage connected to a pivotable lever 62, 118 which controls said adjustment device 36, 116 which is mounted between the anchorage 26, 102 and one brake shoe 12, 12a which is connected to the second brake shoe 14, 14a by a link 50, 50a; said control lever being actuated by a preloaded overtravel spring which yields when the force exerted by the one brake shoe on the adjustment device 36, 116 prevents operation of the lever 62, 118, The actuator is an hydraulic cylinder having two pistons, one in contact with each of the brake shoes. In Fig. 1, the adjustment device consists of a non-rotatable screw 32 which supports the end of the shoe 14 and intrudes into the anchor block 26 at 38. The shoe 12 is supported directly on the block 26. An internally threaded sleeve 42 can be rotated by the lever 62, which has a finger 70 engaging in serrations 44 on the sleeve 42, when the lever tilts on its pivot 72 in the block 26. A cable 54 fixed to a pin 68 on the shoe 12 passes over a pulley 56 on the shoe 14 to a cage 58 for a spring 60. The end of the spring 60 is hooked through a hole 90 in the lever and is held against the lever in a prestressed condition by a return spring 64 which loops through a hole 80 in the lever to bias it in a clockwise direction. When, due to application of the shoes 12 and 14 to the brake drum the pull on the cable 54 on the lever exceeds the force of the spring 64 on it the lever tilts to turn the adjustment device. When due to force exerted by the shoes the adjustment can no longer turn, further movement of the cable is taken upon the spring 60. On release of the brakes the link 50 apportions the adjustment between the two shoes. A lever 52 pivoted also at 68 and operated by the parking brake cable 92 also engages the end of the link 50. In consequence, no separate adjustment of the cable 92 is necessary due to worn brake linings. |
