| 摘要 |
<p>The device has a piston (21) provided with outer and inner side parts (211, 212), and a mounting space (213) introduced into the inner side part. A base forms an inner side wall extending towards the inner side part. A joint cover (23) whose outer diameter is smaller than an inner diameter of the mounting space. An elastic object assembly (22) is introduced between the joint cover and the piston, and the outer side wall extends between parts of the joint cover, such that a releasing action is obtained. One of the parts of the joint cover is accommodated in the mounting space.</p> |
