| 摘要 |
The invention relates to a threaded fastener for engagement with a cylindrical screw thread of either a threaded bore or a threaded screw. The threaded fastener includes a hollow sleeve for concentric alignment with the cylindrical screw thread. The sleeve has a plurality of segments (30) arranged in a discontinuous circular array at one end. The plurality of segmants (30) either converge towards or diverge away from the central axis. The threaded fastener also includes an activation means to bring the segments substantially parallel to the central axis whereupon a first series of threads (32) provided on a surface of one or more of the segments (30) align and engage with the cylindrical screw thread. |
