|country of origin:||Czechoslovakia|
|approximate dimensions:||2400x900x1600 mm|
|year of production:||unknown|
Grain winnowers used to be common agricultural machines designed to clean and sort grain before storage and further processing. Craftsmen made all-wood winnowers well before the Thirty Year's War. In the second half of the 19th century first manufactured winnowers began to appear in the country. Air sifters were used to sort grain based on its weight by means of air stream. Winnowers, which combined air sifters with screens, were then used to clean the grain. Grain winnowers cleaned the grain according to weight with a stream of air. The machine comprised a portable box with a sheathed toothed mill driven by a hand crank. The grain was fed from a hopper onto three suspended screens where it got separated and sorted into individual fractions. The manufacturer of the exhibit is unknown.