| 摘要 |
<p>The invention relates to a device for covering and closing manholes of municipal water, sewage, electric power, fiber optics and telephone systems. According to the invention, the device consists of a cover (1) made of a composite material, assembled with a frame (2) of ductile cast iron by means of a closing and safety system ( c) provided with a profiled-headed screw (d) and a special wrench, the frame (2) being internally provided with a profile (b) allowing a sealing gasket (a) to be inserted with a view to preventing water to seep into the manhole.</p> |
