Adjustable vane system for an axial flow rotor housing of an agricultural combine

An adjustable vane system for an axial-flow, rotary combine housing that incorporates at least one flat wall section as part of the otherwise cylindrical or oblong, curved housing cover, and adjustable vanes having flat bases that are angularly adjusted on the surface of the flat wall section. The housing includes fixed vanes on a curved portion of the housing cover that have a lead ends, in a direction of circumferential crop movement, substantially in registry with trailing ends of the adjustable vanes. The adjustable vanes include pivot connections near the trailing ends and swing connections near the lead ends of the adjustable vanes. All of the adjustable vanes are gang together and moved together. A mechanism is provided to swing the adjustable vanes from a position corresponding to the normal helical path of the fixed vanes to a bypass position wherein crop flow through the adjustable vanes will skip one or more passes between the fixed vanes on the next pass through the fixed vanes.