| 摘要 |
A sharpening head with a conical stone or burr is spring biased for application to the end of a spinning paper drill bit brought down on the apex of the cone. As the drill depresses the head, a pin extends through the apex of the cone to push any paper scrap out of the end to be sharpened and up into the drill. This assures that the sharpening force between the head and the drill bit is determined by the bias of the spring. The spring forces the sharpening head linearly upwardly along the pin and within an internal cylinder in a base which encloses a cylindrical extension of the head. In an alternative embodiment, spacer blocks and a lever are provided to adjust the initial height of the sharpening head. The alternative embodiment is useful to sharpen automated paper drills whose range of movement is relatively fixed.
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