| 摘要 |
For joining purposes, the boards at their crossing points have slots on their facing edges to a depth corresponding to a half width of the boards. The first and last groups of boards (11, 12,41) cross each other and are connected to one another at least at one point (71,72), so that the other boards of the book shelf are held together by being tensioned between the crossing and interconnected boards (41,11,12). |
