| 摘要 |
<p>Means adapted for retaining a shank in a recess. The retaining means comprises a resilient collar having an inner surface adapted for coacting with the shank and a peripheral surface adapted for co-acting with the walls of the recess. The peripheral surface is eccentrically displaced with respect to the inner surface. The inner surface of the retaining means, and a co-acting surface of the shank, have complementary regular polygonal shapes.</p> |
