| 摘要 |
PROBLEM TO BE SOLVED: To surely prevent a lid body from being opened when an uplift pressure of a turbulent flow is generated in a manhole, and to eliminate a need for checking whether the lid body is completely locked when it is closed, in a locking device of the lid body of an underground structure. SOLUTION: When the lid body is closed, it is rotatable circumferentially within a predetermined range. A lock member 23 is rotated radially inward by the rotation of the lid body. A releasing guide part 36 is provided under a hook part 26 to forcibly move a click part 25 of the lock member 23 from a locking position, where the click part 25 is engaged with the hook part 26 provided on an inner peripheral wall of an opening part of a receiving frame, to an unlocking position. A guide member 39 is mounted on the inner peripheral wall near the releasing guide part 36. The guide member 39 has an inclined face for automatically guiding a lock member 23 to the position where it is engaged with the hook part 26 by coming into contact with the lock member 23 to slide the lid body in the circumferential direction when the lock member 23 is displaced in the circumferential direction from the position of the engagement with the hook part 26 upon closing the lid body. COPYRIGHT: (C)2007,JPO&INPIT
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