| 摘要 |
A clamp for clamping a tubular article 92 includes a plurality of pads 10 which may be arranged in a circle within a support frame 90 and connected thereto by arms 26 pivotable about an axis at 60 parallel to the axis of the article 92. The pads 10 are supported on the arms 26 by ball-joints or universal joints (fig. 12) such as to ensure any off-centre load is passed through said pads 10 as a vertical load having no radial component. The arms 26 are pivoted by actuators 66 to cause the pads to clamp against the article 92 (fig. 8) and cables extending over the outside of the pads can be tightened to maintain/enhance the grip. Each pad can be formed from a set of pivotally connected strips 12. Two frames 90 can be employed one above the other and interconnected by actuators so that sequential clamping can move the frames along the article 92 for example for climbing a vertical article such as a wind turbine mast. A crane can be mounted on such an arrangement. |
