US Patent: 887,423
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Automatic screw-driver
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Patentee:
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William M. Pratt (exact or similar names) - Greenfield, MA |
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Patent Dates:
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Applied: |
Nov. 07, 1906 |
Granted: |
May 12, 1908 |
Patent Pictures:
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Steve Gosselin "Vintage Machinery" entry for Goodell-Pratt Co.
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Description: |
"My invention relates to spiral ratchet screw drivers and its object is to provide such a tool which is compact and simple in construction, pleasing in appearance and highly efficient in use... The invention particularly appertains to the type of spiral ratchet screw driver which includes a spiral spindle, a barrel fitted to the tool handle in which the spindle is axially guided, a pair of ratchet wheels housed within the barrel having keys engaging the spiral grooves of the spindle, pawls carried by the barrel and co-acting with the ratchet wheels and means for shifting the pawls to disengage the same from their respective ratchet wheels." |
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