science · 30 November 1875 · 150 years ago
In 1875, the first U.S. patent for an oat-crushing machine was issued to Asmus.J. Ehrrichson, of Akron, Ohio (No. 170,536). The patent description gave that previously this had been done "by crushing the grain between rollers, or grinding with burrs or millstones, and subsequently screening ... into different grades." This, it said, resulted in inferior quality due to excessive amounts of flour that was too fine. The invention instead used a series of horizontal knives fixed in a frame through which oats fall from a hopper with a perforated metal bottom. Lateral motion of the hopper causes grain moving through the holes to be sheared against the knives thus producing a desirable coarse grain meal.
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