| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the attachment of a locking member and a supporting member and to improve reliability by providing a rotation regulating member allowing the rotation of the locking member in a 1st direction and regulating the rotational amount in a 2nd direction opposite to the 1st direction. SOLUTION: When a lock ring 76 fit in a bottom board 71 is rotated in a clockwise direction, a hook 71k runs onto a hook relief part. When the rotation of the ring 76 is kept further, the tip of the hook 71k is caught by the step part 76h of the ring 76, so that the rotation of the ring 76 is prevented by the hook 76k and the step part 76h even if the ring 76 is tried to be rotated clockwise. Therefore, the ring 76 is rotated counterclockwise to an angle at which a lock ring regulation part 76g abuts on a bottom board projection 71i from the above state, and locks/unlocks a supporting frame 77 between the angles. In such a case, the hook 71k functions as the rotation restricting member allowing the rotation of the ring 76 in the counterclockwise direction (1st direction) and restricting the rotation in the clockwise direction (2nd direction). |
