| 摘要 |
<p>A reset knob 20 is mounted to a tip end of a shaft. A front cover 24 having a resilient locking arm 23 is mounted to the reset knob 20. The base body 15 is formed with an engaging projection 25. The resilient locking arm 23 and the engaging projection 25 are engaged with each other at an initial position of the shaft, thereby forming an engaging portion B between the base body 15 and the front cover 24. Therefore, it is possible to prevent the shaft from sliding by factor such as impact and vibration other than sublimation of the gas-starting agent, and to prevent the power circuit from being interrupted. <IMAGE></p> |
