| 摘要 |
PURPOSE: A spiral manhole having an adjustable angle is provided to remarkably improve construction convenience and quality by freely controlling the size of the manufactured manhole on a construction site. CONSTITUTION: A spiral manhole having an adjustable angle comprises a pipe-shaped main body(10) and a top closing unit(20). The top of the main body is opened, and male screws are formed on the outer surface of the main body. The top closing unit is coupled to the top end of the main body, and female screws having the same pitch as the male screws of the main body are formed on the inner surface of the top closing unit. When the top coupling unit is coupled to the main body, gaps are formed between the upper screw treads(21) of the female screws and the threaded rods(12) of the male screws so that the top closing unit can be moved. |
