US Patent 7716908 Self-clearing row unit and stalk roll

A row unit comprises a row unit gearbox with two shearing edges and two stalk rolls with corresponding shearing edges, wherein the stalk roll shearing edges shear against the gearbox shearing edges when the stalk rolls rotate during normal operation of the row unit, thereby chopping material that might otherwise be wrapped around the row unit gearbox and be jammed between the stalk rolls and the gearbox.