| 摘要 |
<p>The self-tightening lifting tackle is for loads such as heavy sacks, having two rings pivoting on parallel axes fixed in relation to each other. The rings (10, 12) are of identical dimensions and fit in parallel tubular sheaths (6, 8) fixed solidly to each other. The sheaths are spaced apart in the vertical and horizontal directions for a distance equal to the mean section of the ring material. They can be welded to a supporting bracket (2) in turn connected to a lifting device (4). The distance between the rings at their lowermost portions can be greater than their section diameter.</p> |
