| 摘要 |
<p>The screw (10) has a first polygonal head (12) connected by a shearing neck (14) to a second polygonal head (16), the neck having a smaller diameter than the heads or the shank (18) of the screw. Between the two heads the screw has a cylindrical section (20) in addition to the shearing neck and having a diameter at least as great as that of the neck and smaller than that of the second head, with which the cylindrical section forms a shoulder (16a). The tool for use with the screw has a tip (32) with a drive to rotate it, the tip comprising a tube (34) with an inner diameter shaped to receive at least the first head of the screw, a receiving section (36) for the sheared screw heads, an open end, and one or more spring-loaded balls between the two. Once the screw head has sheared off at a given torque it is held in the tool's receiving section, leaving a second head which can be used for removing/replacing the screw.</p> |
