| 摘要 |
<p>The Allen screw (1) has a socket (2) in the head with a non-round sidewall (3) for engagement by the key, also a cone face (6) tapering towards the inside. The cross-section of the driving faces can contain no straight lines, and they can be so designed that they generate no forces in the axial direction of the screw, and form alternate protrusions and recesses. Apart from the cone face, the sidewall can be parallel to the lengthwise axis. The key can be of complementary shape to the socket.</p> |
