| 摘要 |
PURPOSE: A waterproof connecting structure of a manhole frame and a manhole cover is provided to prevent sewage, rainwater, or calcium chloride solution from permeating into a manhole. CONSTITUTION: A waterproof connecting structure of a manhole frame and a manhole cover comprises a manhole frame, a coupling, and a manhole cover(20). The manhole frame has an outer frame body and multiple spiral protrusions. The outer frame body is integrated with a cylindrical pipe body. The spiral protrusions are protruded from an inner frame body. The coupling unit has a circular plate body(21) and multiple spiral protrusions. The spiral protrusions are protruded from the outer surface of the circular plate body. The manhole cover has knobs(30) installed in both sides of the circular plate body. |
