| 摘要 |
PURPOSE:To have automatic gap adjustment while preventing trailing of the brake shoe, by carrying out disengagement of the adjusting lever from the strut of a drum brake using a bimetal. CONSTITUTION:When pressure liquid is fed into a liquid pressure cylinder device 20, the top of a brake shoe 2 is widened with its bottom as fulcrum against the action of a spring 37, and thereby the lining 7 is pressed against the inside circumferential surface of the brake drum to give application of brakes. The adjusting lever 31, on the other hand, shifts to the left together with the brake shoe 2, and when the right edge of a hole 38 comes in contact with a boss 34a of the control lever 41, a relative rotation is generated between the adjusting lever 31 and web 3, when the bottom of the adjusting lever 31 will get over the tooth of a latch 32 to make adjustment of the gap. A rise of the temperature in the brake drum will cause a counterclockwise turn of the control lever 41 owing to elongation of the bimetal 45 to set off the boss 41a from the hole 38. |
