| 摘要 |
A manhole cover opening and closing device is provided to prevent falling by tightening strongly from three directions, to increase efficiency, and to prevent the separation of an inner rubber packing. A manhole cover opening and closing device includes three legs, wherein one of the legs is located in the central rear part, and the three legs are pulled tightly in three directions by turning a handle and turning a full-thread bolt and a nut to let two persons work safely. |
