| 摘要 |
The present invention relates to a manhole cover in which an invention according to a patent 10-1264059 of this applicant is improved. The present invention is to provide a manhole cover capable of maintaining a stable locking state by preventing a locking state from being automatically locked and unlocked without manipulation of an operator. The manhole cover includes: a cover plate having a shaft hole; multiple support shafts fixed at fixed intervals on the bottom of the cover plate in all directions; a male screw wherein a body unit is inserted by passing through the shaft hole of the cover plate and a head unit is exposed to the upper surface of the cover plate; an ascending unit having a female screw corresponding to the mal screw and formed in the center to ascend according to rotation of the male screw, wherein multiple holder grooves are formed on the side of the ascending unit; multiple locking levers wherein the center is connected to the support shaft by a pin and one end is inserted into the holder groove of the ascending unit, so the locking lever see-saws on a support shaft according to ascent of the ascending unit and the other end is selectively attached to the inner circumference of a manhole rim; and a retaining ring fixed to the male screw between the bottom of the cover plate and the ascending unit and preventing the male screw from ascending or being separated from the cover plate. |
