| 摘要 |
<p>A fixing, preferably a threaded bolt, comprising a dome shaped head 28 constructed from a circular profile with opposing flats surfaces 29 allowing it to be inserted into a channel and rotated preventing withdrawal. Preferably two diagonally opposing corners are for right angles preventing further rotation past 90 degrees. The dome shaped head which may be elliptical provides a camming action against the channel, which may have a curved half elliptical profile in cross section, in which the fixing is inserted forcing the fixing against lips of the channel.</p> |
