| 摘要 |
PURPOSE: To align brake shoe friction elements in parallel for a rotary face of a brake surface of a brake drum by providing a guide device maintaining substantially parallel alignment between a drum shoe web and a spider at both expansion and shrinkage positions of a brake shoe. CONSTITUTION: Brake is connected and disconnected by bringing a surface 24 of a brake shoe 18 into contact with an inner face 26 of a brake drum 10 and separating them due to the drive and stop of an air motor 6. In this case, a guide device 50 is provided on a side face of a spider 38 to face lower and upper slide faces 66, 48 of a web structural body 16 so that the web structural body 16 maintains substantially a fixed distance from the spider 38 when the brake shoe 18 turns around an anchor pin 30. That is, a first arm and a second arm 54 oppose and come into contact with the slide face 46, and a third arm 57 is engaged with the slide face 48 of the web structural body 16. The arm 57 presses a guide face 58 against the slide face 48 elastically by elastic force F to apply the slide face 46 on a guide face 56 apart at a fixed distance. |
