| 摘要 |
The invention provides a helical device for engagement with a cable, the helical device comprising a single length of metal strip comprising a first helical section (1), a second non-helical section, and a third helical section, the end (3) of either or both the first and third helical sections remote the second helical section being flared away from the longitudinal axis of the helix, the flaring being in the form of a section of spiral helix form. Also provided is a method of producing such a device, which method comprises the steps of: i) feeding strip material to an apparatus, ii) within the apparatus automatically activating helix forming means to form a first section of the strip material into the shape of a helix, iii) within the apparatus automatically inactivating the helix forming means so as not to form a second section of the strip material into the shape of a helix, iv) within the apparatus automatically activating the helix forming means to form the third section of the strip material into the shape of a helix, v) selectively controlling the helix forming means to produce between helical sections of adjacent devices sections of increasing and then decreasing diameter, the strip being cut between the sections of increasing and then decreasing diameter, either prior of subsequent to the formation of the section of decreasing diameter, to provide the flared ends of the two adjacent devices, vi) repeating steps i) to v) to produce further devices.
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