| 摘要 |
A frame for a manhole cover or a gully grating has an external flange 2, the underside of which has pockets 6,8 to improve the security of the frame's mounting in the ground. The pockets 6,8 may be sub-divided bay ribs 9. Further projections 13,14 may extend from the flange 2 in an upward or downward direction. |
