US Patent: 179,778
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Improvement in countersinks
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Patentee:
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William B. Erskine (exact or similar names) - New York, NY |
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Patent Dates:
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Applied: |
Apr. 28, 1876 |
Granted: |
Jul. 11, 1876 |
Patent Pictures:
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Jeff Joslin
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Description: |
An example has been seen stamped only with the patent date."I employ two countersinking cutters. The outer face of each cutter is a portion of a cone, so as to afford a bearing on considerable surface. It is thus less liable to be disturbed in position by knots or other hard places. Furthermore, to avoid side pressure and strain upon the bit, consequent upon the cutting device being upon one side only, as in previous devices of this character, I deem it important that the same should be upon opposite sides, and, acting with equal force in opposite directions, the bit is firmly held in the center." |
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