| 摘要 |
<p>Method of increasing the resistance to pull out of a screw (20) screwed into a receptive substrate (35) which comprises unscrewing the screw and removing it from the hole and then locating a spiral member (140) having an outwardly facing pointed profile in the old threads and screwing the screw into the hole, the spiral member engaging the hole and the screw threadly engaging the spiral member and forcing the pointed profile into the substrate. The bottom end (146 or 182) of the spiral member is shaped so as to be disconnectably engageable by a tool (160) inserted down the centre of the spiral member whereby the force to screw the spiral member into the hole can be exerted from the bottom end of the spiral member. The spiral member is made of intermediately malleable material (as defined herein), the spiral member being turned inwardly and back down the axis at one end to afford a drive pin (182), and preferably being tapered towards the end affording the drive pin. The spiral member is thus deformable by the screw whereby the bottom end of the spiral member can be distorted out of the way of the screw by the screw. A tool for inserting the spiral member is also described.</p> |
