US Patent: 430,344
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Auger
Single Twist Auger Bit
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Patentee:
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| Francis I. Hoefle (exact or similar names) - Wilmington, OH |
| Manufacturer: |
| Not known to have been produced |
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Patent Dates:
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| Applied: |
Jul. 26, 1889 |
| Granted: |
Jun. 17, 1890 |
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Jeff Joslin (dm)
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Description: |
| The cross-section of the "blade" of this single twist bit remains constant throughout its length. The upper (tangward) surface is concave and the lower surface is convex, and it is somewhat wedge shaped so that the outer edge is a continuous spiral knife-edge. The goal is to provide maximum clearance for the chips to exit .
For a very similar single-twist bit patented the following year, see Ford's patent (461897). |
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