| 摘要 |
The stand (1) has two or more arms (2-4) joined by hinge pins (5,5). A valve-controlled hydraulic tube runs through the arms and the pivot. An actuator connected to the hydraulic tube to supply hydraulic pressure and to secure or clamp the arms and the pivot in a given arrangement. One or both of the arms is formed of two pieces (3a,b) linked such that the first arm-part (3a) can rotate about the second arm (3b) on a longitudinal axis (8). The first arm-part can be hydraulically locked in position with respect to the second arm. |
