US Patent 6966506 Method and apparatus for harvesting crops

A method and system of harvesting crops involves cutting and threshing the crop, separating graff (a mixture of grain kernels, chaff, weed seeds, and other organic matter) from straw (plant stalks), and returning the straw to the field. This is preferably carried out in a harvesting unit of the pull type having a graff storage tank. The collected graff is moved to a stationary cleaning mill in a different location by means of a suitable vehicle such as a truck. Storage of the graff prior to cleaning is avoided and the cleaning mill, and preferably the harvesting unit and vehicle, are designed to make this possible. This avoids difficulties caused by the poor material flow of graff. Various details of the equipment are also novel.