On this day in 1891 Olof Sundgren was granted the patent for Centrifugal Winnowing Apparatus. U.S. Patent No. 455,977.
The separation of particles of different weights is effected by this apparatus by throwing them freely upward and outward into the air by means of a rotating disk or drum. This apparatus differs from others employed for the same purpose partly in the devices for conducting the particles into one disk and partly in other details, whereby the particles, instead of being thrown straight outward in a horizontal direction, are thrown outward and upward at an angle of about thirty degrees with the horizon. Further, the particles are not thrown out around the whole circumference of the disk, but only around a part of the same toward one or more sides of the apparatus.
