US Patent 7306174 Broadcast width and location control for a combine spreader

A work vehicle having a fluent material spreader comprising two counter-rotating variable speed impellers adapted to receive and broadcast fluent material. A right-side impeller broadcasts out to a right-side material broadcast width, and left-side impeller broadcasts out to a left-side material broadcast width. Rotational speed of the right-side impeller is commanded to achieve a desired a right-side material broadcast width, and rotational speed of the left-side impeller is commanded to achieve a desired a left-side material broadcast width. Command of the right-side and left-side impellers is achieved either manually by and operator, or automatically by a control system based on sensor input.