| 摘要 |
PURPOSE: An anti-overflow device for a manhole is provided to prevent a manhole cover from becoming damaged due to the weight of vehicles. CONSTITUTION: An anti-overflow device for a manhole is as follows, A manhole cover(6) is settled on a frame(4) having a settling projection. The manhole cover is made by connecting a lower member(10) having a shock absorbing function to an upper member(8). A plurality of inlets(20) is formed in the upper member. A circular space is respectively formed over the upper and lower members. The lower member comprises a drain outlet(22). An opening and closing ball(14), which moves up and down is placed in the circular space. |
