| 摘要 |
PROBLEM TO BE SOLVED: To provide a cover device for an operation tool hole of a manhole cover, which is structurally simplified to the utmost, which can be manufactured and worked at a low cost, and which enables an operation for attachment/detachment of a cover plate to be lightly performed by a screw motion. SOLUTION: A stopper plate 4 is supported on an undersurface of the cover plate 3 for covering the operation tool hole 2 of the manhole cover 1 from a top surface side, in such a manner as to be vertically turnable on a pivot 5; a driving bolt 7 is screwed into a screw hole 6 which vertically passes through the cover plate 3; a tip part 8 of the driving bolt 7 butts against a top surface of a base-end-side part 9 of the stopper plate 4; the amount of the screwing of the driving bolt 7 into the screw hole 6 is increased/decreased so that the stopper plate 4 can be turned in the hole 2; and a tip-side part 10 of the stopper plate 4 is engaged with/disengaged from a retaining part 11 on the side of the manhole cover 1, from an undersurface side, so that the cover plate 3 can be detachably fastened and fixed to the manhole cover 1. COPYRIGHT: (C)2005,JPO&NCIPI
|
