| 摘要 |
<p>PROBLEM TO BE SOLVED: To easily and securely attach and detach a cover body to and from a plug device which mechanically opens and closes a pipe opening or hole.SOLUTION: A first magnet 65 in a circular ring-shaped flat plate shape is fitted to a reverse surface center part of a cover body 6. A second magnet holding member 7 which holds a second magnet 71 having the same shape with the first magnet 65 is fitted to a periphery of an operation shaft member 5. Then the cover body 6 and the operation shaft member 5 are attracted with the magnetic force (attraction force) of the first magnet 65 and the second magnet 71 fitted at mutually opposite positions. Thus, the operation shaft member 5 is attracted with the magnetic force of the cover body 6, so that the cover body 6 can be easily and securely attached and detached.</p> |
