| 摘要 |
PROBLEM TO BE SOLVED: To provide a manhole cover equipped with a clamp device in which biting or galling does not occur between a bolt and a clamp metal fitting even when the clamp metal fitting for fixing the manhole cover to a closed position is fastened in an inclined state relative to the horizontal direction with the bolt.SOLUTION: A manhole cover device includes: a clamp metal fitting 24 arranged below a manhole cover 3 closing a rising tube 1, and disengageably engaged with a groove 10 of an annular frame 2 fixed to a top edge of the rising tube 1; a bolt 25 inserted through a long hole 16 of the manhole cover 3 and a through-hole 31 of the clamp metal fitting 24; a nut 26 threadingly fitted to the bot 25 below the clamp metal fitting 24, and a nut nonslip member 27 attached to the lower end of the bolt 25. The undersurface of the clamp metal fitting 24 is in spherical contact with the top face of the nut 26, and a whirl-stopping part 32 restricting the rotation of the nut 26 is formed under the undersurface of the clamp metal fitting 24. |
