US Patent 12016271 Weed seed destruction with improved wear characterisitics

Weed seeds are destroyed in the chaff from a combine harvester by repeated high speed impacts caused by a rotor mounted in one of a pair of side by side housings which accelerate the discarded seeds into contact with stator bars at angularly spaced positions around the axis of the rotor. U-shaped bars are symmetrical and can be reversed when the second leg is worn for extended life. Parts of the rotor and stator which are radially outward of other parts are formed with a higher resistance to wear approximately proportional to the radius so that the wear characteristics of the different parts are matched to the velocity of the particles impacting the different portions to generate symmetrical wear throughout the structure.