| 摘要 |
PROBLEM TO BE SOLVED: To safely and easily perform an opening/closing operation of a heavy subsidiary lid of a manhole by oneself. SOLUTION: This device is composed of a square main lid 1, the paired subsidiary lids 20, and a fixing bar 30 and a fall preventing stopper 40 for each of the subsidiary lids 20. In the main lid 1, a square opening 2 is formed inside it; locking edges 6 and 7 are provided so as to face each other along central parts of both lateral sides on a long side of the opening 2 and both lateral sides on a short side thereof, respectively; and guide rails 11 equipped with guide holes 10 are provided along both right and left side parts of each of the lateral sides on the long side, respectively. The subsidiary lids 20 are juxtaposed with a gap 21 between them; peripheral edges of them are formed so as to be large enough to be placed on the locking edges 6 and 7; and a rotating shaft 25 is provided in approximately central parts on both lateral sides of each of the subsidiary lids 20, so that a roller 26 can be attached to the rotating shaft 25 and mounted so as to be movable on the guide rails 11. The fixing bar 30 is inserted into the gap 21 between the subsidiary lids 20, so that both ends thereof can be detachably attached to a central part on the long side of the main lid 1. In the stopper 40, bearing fittings 43 and 46 are provided in appropriate places on each of the backsides of the main lid 1 and the subsidiary lids 20, respectively, and both ends of a supporting rod 41 are attached to both of the bearing fittings 43 and 46. COPYRIGHT: (C)2004,JPO
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