| 摘要 |
<p>Covers for drains, manholes or similar constructions consisting of multiple grates (10, 20), each produced from a single sheet of sheet metal, combined together to form a single cover or grating. The use of multiple grates allows for large gaps (21) between each strut of each grate, each gap representing half of the sheet material bent to 90 degrees below the strut to form the strut side (12), without affecting the overall spacing in the finished grating system. This allows improved strength of a grating without the cost of a thicker sheet material. Each grate is combined with the other grates, in a permanent fashion, with the struts of each grate aligning with gaps in the other grates.</p> |
