US Patent: 45,294
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Milling Machine Improved Cutter for Cutting Gear-Wheels
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Patentee:
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Joseph R. Brown (exact or similar names) - Providence, Providence County, RI |
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Patent Dates:
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Granted: |
Nov. 29, 1864 |
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Joel Havens "Vintage Machinery" entry for Brown & Sharpe Mfg. Co
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Description: |
From Studies in the History of Machine Tools by Robert S. Woodbury.
"At the time the involute method of determining gear-tooth shapes had been shown (by mathematicians) to be superior to the epicycloidal method, but practice lagged far behind as practical men stuck to the traditional epicycloidal approach. The first version of that Brown & Sharpe gear-cutting machine, introduced in 1864 or 1865, had available sets of 24 cutters for epicycloidal gears, sufficient to cut all gears of a given pitch, from a 12-tooth pinion gear to a rack. In 1867 they introduced cutter sets for involute gear teeth, each set requiring significantly fewer cutters than the equivalent epicycloidal set, and was therefore less expensive. As the only maker, at the time, of gear-cutting machines, Brown & Sharpe's introduction of involute cutters was vital to the move away from epicycloidal gear designs." |
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