摘要 |
The slabs (2,3) have profiled edges (4,5) which lock together. The first edge has a tongue (6) which projects into a groove (20) in the second profile. The top part of the first edge (9) projects further forward than the bottom part (8). The bottom part (21) of the second edge projects further forward than the top part (22). The bottom surface (7) of the tongue on the first edge is convex and matches a concave portion (23) in the groove. The top surface of the tongue is horizontal at the root, then slopes gently downwards. The bottom of the groove is of rectangular cross-section. |