US Patent: 339,544
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Combined boring-tool and holder
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Patentee:
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Simon Peter Graham (exact or similar names) - Galt, ON Canada |
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Patent Dates:
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Applied: |
Jul. 14, 1885 |
Granted: |
Apr. 06, 1886 |
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Jeff Joslin owwm.org discussion of Graham shank drill bits
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Description: |
This invention is a special drill chuck and drill-bit shank that provided positive non-slip engagement. They were particularly useful in production applications with multi-spindle drilling machines where a dull bit might not be noticed immediately. The chucks and bits were manufactured by several companies, including the inventor's company after he relocated to Detroit."This invention relates to improvements on shanks of drills for boring iron, or shanks of bit for boring wood, or any boring-tool where a holder is required to hold it while rotating same; and this invention consists of a drill or wood-bit in the shank of which two grooves are formed, to which grooves the jaws or prongs of the holder are fitted, so as to hold said drill or bit while it is being rotated." |
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