| 摘要 |
1306465 Paving blocks R JORDAN 12 Oct 1970 [13 Oct 1969] 48330/70 Heading E1B An integral concrete or plastics paving block (seen from below in Fig.) comprises an upper rectangular layer 1 and a lower interlocking layer having two recesses 5 on each side surface, two complementary tongues 4 on each of one pair of opposed side surfaces and two flattened portions 8 on each of the other pair of opposed side surfaces. The upper surface of each tooth is sloped downwardly from the root to the apex and the recesses are of complementary shape. The teeth and recesses may be curvilinear instead of angular. |
