| 摘要 |
The three legs of the mast are joined at their upper ends, and in the formation of the lifting equipment two of the legs (2,3) are placed on the ground joined at one end to one another. Each of the legs forms part of the mast top after raising. The other ends of the legs, which will form the lower ends of the mast, are placed apart by a distance corresp. to one side of a triangle. Via a joint, one end of the third leg (4) is joined to the point of union of the first two, with its lower end directed outwards from the two other legs in the direction of a bisectrix between them. - Between the lower ends of the three legs, a draw line which is coupled, which is suitable for drawing the end of the third leg towards a connecting line between the ends of the other two legs. This has the effect of raising the mast to the required height, at the same time carrying the load it is intended to support. |
