| 摘要 |
PROBLEM TO BE SOLVED: To provide a bolt which can be tightened without using a special tool and cannot be loosened after being tightened, but which is allowed to be loosened in an emergency. SOLUTION: A bolt comprises a first bolt having a through-hole in the center, a second bolt made up of a second bolt shaft which is slidably inserted into the through-hole drilled into the first bolt shaft and is longer than the first bolt and of a second serration provided to one end of the second bolt shaft, and a lock part provided to a second bolt shaft end on an opposite side to the second serration. A first locking part functioning as a locking part in one rotation direction and not functioning as a locking part in the reverse rotation direction is formed on a head part of the first bolt. A second locking part locked in the first locking part provided to the first bolt to turn the first bolt in one direction only is formed on a surface facing the fist bolt head of the second serration. A maximum diameter of the lock part is made wider than a hole diameter of the through-hole and narrower than a diameter of the first bolt shaft. COPYRIGHT: (C)2009,JPO&INPIT
|
