| 摘要 |
<p>An expanding plug has a plain hollow shaft (11) which changes to a tip (12) with circumferential serrations (28). This is split into two halves by a slit (16) which follows a sinusoidal path. With the plug inserted in a prepared hole, the appropriate screw or similar fastener which is driven into the hole (32) through its shaft (11) will encounter the ridges (24a, 24b) formed by the slit (16). Further progress forces the two halves of the tip (12) apart, to hold the plug in position.</p> |
