| 摘要 |
<p>A manhole cover (1) comprising a top (2) and a base (4) which define a space therebetween, and reinforcing walls (8') which extend at least partially between the top (2) and base (4) to define voids (10, 10') within the so-defined space, wherein the reinforcing walls (8'), and hence the so-defined voids (10, 10'), radiate from the centre region of the cover.</p> |
