| 摘要 |
PROBLEM TO BE SOLVED: To provide a square lid device which can be easily and definitely opened with a smaller force as compared with the conventional lid device by advantageously realizing the prevention of ricketiness. SOLUTION: In a square lid device with which the opening of a receiving frame can be closed with the lid body by making the outer peripheral edge portion of the rectangular lid body closed by the lid body by tapering fittedly off the outer peripheral edge portion of a rectangular lid body to the inner peripheral edge portion of the rectangular receiving frame arranged around the opening on ground provided for the predetermined work for articles arranged and distributed underground, the lid body is lifted up relative to the receiving frame, at least one bar hole for inserting a bar for releasing their fitting state is provided at a corner portion of the lid body.
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