| 摘要 |
PROBLEM TO BE SOLVED: To provide a manhole which allows its cover body to be opened by using only a small force. SOLUTION: The manhole is formed of a projection which projects toward the inside of a cover bearing frame, cams which are arranged on respective support pieces arranged on a rear surface of the cover body so as to abut on the projection, arms which each have one end thereof connected to the cam and the other end thereof rotatably connected to a mobile body on the rear surface of the cover body, and an insertion hole formed in the cover body. The manhole includes the plurality of support pieces, and the insertion hole is blocked with a deodorizing packing. Further, a spring is arranged between the mobile body and the rear surface of the cover body. COPYRIGHT: (C)2003,JPO
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