| 摘要 |
PURPOSE:To eliminate necessity for a large pressing force and a large strong spring by providing a maximum twist angle restricting stopper mechanism between a housing and a driven plate and a torque limiter between the housing and a drive plate. CONSTITUTION:A maximum twist angle restricting stopper mechanism, comprising a protrusion 41 and a boss part 35c, is provided between a drive plate 3 and a case 1, a torque limiter 51, comprising a ball 52, a ball stopping recessed part 53 and an energizing spring 55 or the like, is provided between an annular housing 35 and the drive plate 3, and the ball 52 is pressed to a drive plate side by the energizing spring 55 and engaged with the ball engaging recessed part 53. In this way, torque can be transmitted between the drive plate 3 and the case 1, and the ball 52 is dislocated from the recessed part 53 and slipped by a fixed twist torque value or more. By the above constitution to eliminate necessity for large pressing force and many large strong springs, the torque can be easily set to a predetermined torque value to enable a fluctuation by wearing to decrease of a preset torque value. |
