| 摘要 |
<p>The tubular anchor has a hollow cylindrical crown (b). The weight of this is distributed unevenly around the periphery, so that when lying on its side it tends to take up a stable position with one or more claw-like projections (a) from the 'leading' edge at the bottom. These projections may be integral or attached and the crown rim either side is sharpened (c) to form a digging edge. The shank is connected (rigidly or flexibly) to the crown in such a way as to augment the stability of the crown, and is pref. 'snowplough'-shaped (d).</p> |
