US Patent: 11,280
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| Augers, gimlets, &c.
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Patentee:
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| Washington Spangler (exact or similar names) - Harpers Ferry, VA |
| Manufacturer: |
| Not known to have been produced |
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Patent Dates:
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| Granted: |
Jul. 11, 1854 |
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Patent Pictures:
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Jeff Joslin (dm)
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Description: |
| Spangler claims bits based on the principles of this patent will bore cleanly and easily in any direction, including through brash wood, knots, and even iron. The primary features of the patent include the use of a convex blank which produces cutting edges all along the twist, combined with a gradually increasing (or increasing then diminishing) diameter of cut. The idea is to gradually enlarge the hole with shear cutting action while eliminating binding which results from a bit of a consistent diameter along its length. |
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