| 摘要 |
A connecting portion 21 (31) includes a hole portion 22 (33) and a shaft insertion portion 23 (34) that is cut in from an edge of an arm 2 (3) to the hole portion 22 (33) by a width smaller than a diameter of the hole portion 22 (33), and a post portion 42a (42b) includes a shaft 43a (43b) that is attachable to/detachable from the hole portion 22 (33) through the shaft insertion portion 23 (34) only from a predetermined direction when upper and lower arms 2 and 3 are projected to an extent not normally used, and a fixing portion 44a (44b) formed at both ends of the shaft 43a (43b) by a diameter larger than that of the hole portion 22 (33). |
