| 摘要 |
Two rods (13, 13a) have a link connection with their lower ends to a base section capable of swivelling round an axis. The upper end of the rods has a link connection to a holding section (14) to which a third rod (16) is rigidly attached which lies at an angle to the other two rods. The points of rotation of the rods (13, 13a) in the base section (1) and the holding section (14) have the same or almost the same distance from each other. A stay (17) is fitted to at least one of the rods at the point of rotation on the base section with a sliding section having a link connection to its other end, which is adjustable on one of the rods and which may be fixed in any position on it. |
