Watertight man hole cover, especially for underground fuel tanks

摘要

The cover is domed, and is accommodated in a frame (4) with a drain trough (6). The cover slopes downwards to the trough, with its edge over-lapping the latter. Below the cover edge (8) is a peripheral collector groove (9) forming the trough. The groove is covered by the cover's edge, and has a ramp face (10) at the side towards the hole (2), bearing against a mating ramp face (11) at the cover edge. The trough edge with this ramp face is higher than the overflow edge (13) at the trough opposite side.