| 摘要 |
<p>A screwdriver (10) is disclosed as having a drive end (12), a shank (14), and a blade (16) rotatable about a central axis A and having a tip construction that facilitates driving without reducing strength. The screwdriver blade (16) has a length L and includes oppositely facing blade surfaces (18) and a tip (20) that cooperatively define a pair of spaced terminal edges providing a width dimension W, and the blade length L is in the range of about 3 to 9 W. Each blade surface (18) also has an engagement location (24) spaced from the adjacent terminal edge (22) by a depth dimension D that is in the range of about .2 to .5 W. Each engagement location (24) and the adjacent terminal edge (22) define an angle B with the central axis A in the range of about .5 to 3.3°. The screwdriver drive end (12) is disclosed as being embodied a manually grasped handle (29) and is disclosed as having best results with the depth dimension D about 1/3 of the width dimension W, with each angle B about 2°, with the terminal edges (24) spaced from each other by a thickness dimension T and with the depth dimension being in the range of about .3 to 2.5 T and most preferably about 1.2 T; and with the length L about 6 W.</p> |
