US Patent: 2,507,231
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| Screw Driver Having Cruciform Bit
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Patentees:
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| Joseph J. Tomalis, estate of (deceased) (exact or similar names) - Providence, RI |
| Lillian Dolores Tomalis, administratrix (exact or similar names) - Providence, RI |
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Patent Dates:
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| Applied: |
Oct. 29, 1947 |
| Granted: |
May 09, 1950 |
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Patent Pictures:
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Stan Schulz
"Vintage Machinery" entry for American Screw Co.
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Description: |
| Watson, Cole, Grindle & Watson - patent attorneys
Original application 30 Dec, 1942. Divided and this application 29 Oct, 1947.
This patent pertains to the shape of the Phillips style driver to allow for more torque on the screw with less cam out force. (See also patent no. 2,046,838 for earlier Phillips screwdriver patent).
The markings on related screwdrivers hint at a "manufactured under license" arrangement. The piece in the 2nd image is one example.
The full marking on the shank is VACO Made U.S.A. //CHROME VANADIUM STEEL // PHILLIPS POINT No.3 // Pat. No. 2507231 Lic. No. 9
A 2nd known example is marked: IRWIN 3000-3" Made in U.S. of A. (on handle) / Phillips//Lic. 7-Pat//2507231//Made in U.S.A.//No. 1 point//Carbon// (on shank)
The Museum of Connecticut History in Hartford notes a Bridgeport Hardware Mfg. Co. No. 2 Stubby set of a dozen in an original box: Each of them is marked "Phillips/Lic. 7--Pat./2507231/Bridgeport/U.S.A.--Carbon/No. 2 Point."
4th known example with wood handle is marked on the shank: PHILLIPS - LIC. 40 / PAT. 2507231 / CHROME VANADIUM / No. 3 PT - U.S.A. / |
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