| 摘要 |
<p>The element consists of a square panel (1,2) of uniform thickness, made in one piece from moulded rubber or elastomer material. The panel's upper surface is smooth, while its under surface has projecting ribs in orthogonal rows. The edges of the panel has square U-section ribs (5,6) with their open edges facing upwards on two sides of the panel and downwards on the other two, so that each panel can make an interlocking engagement with its neighbours. <IMAGE></p> |
