| 摘要 |
A brake assembly for engaging the periphery of a rotatable member, the brake assembly being energized by rotation of the rotatable member in either direction. The brake assembly includes a movable brake shoe which may be forced into contact with the periphery of the rotating member. The brake shoe has spaced apart rollers which are held in engagement with converging ramps on a wedge block. The brake shoe is permitted to shift laterally with respect to the ramps, and as the brake shoe engages the rotating member one of the rollers will move downwardly along one of the ramps to affect self-energization of the brake shoe. The wedge block is provided with a downwardly extending projection which is disposed between the converging ramps, the projection being received within a recess formed in the brake shoe, the recess being of greater width than the projection. The recess and projection limits the lateral shifting of the brake shoe which takes place during self-energization and permits disengagement of the brake shoe even when a lateral shifting force is being imparted to the brake shoe by the rotatable member which would normally cause further self-energization. |
