| 摘要 |
The manhole cover, e.g. for a pipe or cable inspection chamber, consists of a surrounding frame (1) and hinged panels (10,11,12,13) which form the lid. The panels are in the form of right-angled triangles hinged to adjoining sides of the frame so that each pair closed to make a square section of the lid. Each of the triangular panels except one, have a lug projecting from its edge which engages with the underside of the edge of an adjacent panel. The final panel with no lug is equipped with a locking mechanism which fixes it to the frame. |
