| 摘要 |
PURPOSE: A 3-dimentional cubic block is provided to be easily coupled to and separated from other blocks by a small force. CONSTITUTION: A 3-dimentional cubic block is easily coupled to and separated from other blocks by using a plurality of blocks each of which has a convex part(2a,2b) and a concave part(3a,3b). The convex part has a cylindrical part from one end to a position in a longitudinal direction of the concave part. The concave part has a polygonal groove from the inlet of the concave groove to a position in a depth direction of the concave part. The other part of the concave is a circular groove. |
