| 摘要 |
In a method of lowering and raising loads by means of a jack assembly and lifting element the load is transferred from the lifting element by supporting means disposed on the lifting element and having a cross-section considerably larger than that of the lifting element. The supporting means are alternately carried by preferably dismountable carrying members with holes for the lifting element, which holes are smaller than the cross-section of the supporting means, the carrying members being mounted on relatively movable parts of the jack assembly. |
