| 摘要 |
PROBLEM TO BE SOLVED: To rationally perform opening and closing of a manhole, by solving the problem that: different kinds of opening/closing devices corresponding to different covers respectively have to be inconveniently used when opening and closing the covers of various kinds of manholes; and although grip structures of the opening/closing devices are different from each other probably for preventing the inside of the manhole from disturbance or traffic hindrance, this fact is very inconvenient in a case of emergency or when inspecting caution districts.SOLUTION: Two kinds of basic tip metal fittings are attached to one manhole opening/closing device and are made to be freely movable, thereby enabling covers of most manholes to be opened and closed. |
