| 摘要 |
PURPOSE:To automatically adjust the brake clearance of the air brake and yet prevent the overadjustment thereof by a structure wherein a unidirectional feed mechanism for rotating a power screw by some quantity through a clutch is provided apart from the rocking of an arm. CONSTITUTION:In proportion to the increase of the brake clearance, the amount of rocking movement of the arm 20 is increased and also the amount of forward movement of an adjusting rod 35. When the forward and backward of the rod 35 exceeds a determined amount, a key 31 is shifted, resulting in rotating an adjusting gear 30 and consequently rotating a worm wheel 28 through a worm 29 and finally generating an excess threading rotation of the power screw 16 by the rotation of the worm wheel 28. Since the adjusting rod 35 retreats only by the amount determined by the amount of rocking of the arm 20, the brake clearance is kept constant. On the other hand, the gear 30 and the worm 29 form the clutch comprising parts 30a and 29a and because said clutch turns to be brought into disconnected state when the braking is performed accompanying elastic deformation, the gear 30 is rotated being accompanied by the key 31, resulting in performing no adjustment. |
