US Patent: 404,197
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| Auger-Bit
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Patentee:
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| Charles H. Irwin (exact or similar names) - Wilmington, OH |
| Manufacturer: |
| Not known to have been produced |
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Patent Dates:
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| Applied: |
Oct. 20, 1887 |
| Granted: |
May 28, 1889 |
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Jeff Joslin (dm)
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Description: |
| This patent is billed as an improvemnt on his previous patent, 361522, of two years before. The aim of the changes is to provide a more equalized, or balanced, performance by the bit. The convolute blade which runs the full length of the body terminates in a typical cutting, or floor, lip. No spur. The shorter convolute blade is equipped with a modified spur, and while a cutting lip is present, it is at a slightly retracted level from the cutting lip of the primary blade. Thus, the short blade circumscribes the hole with its spur, while the main blade, on the opposite site of the bit, cuts and lifts the chip out of the hole. The secondary cutting lip on the shorter blade allows the bit to be used if the other cutter is broken, though not in as balanced a fashion. |
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