Forage harvester recutter screen

Abstract

A forage harvester has a cutterhead housing with a rotary reel type cutterhead mounted therein, the cutterhead having a plurality of knives parallel to the cutterhead axis at the cutterhead periphery, the knife edges generating a cylinder as the cutterhead rotates. The cutterhead reduces crop material that is fed into the housing and discharges the reduced material through a discharge opening to a conveying system that conveys the crop material to a crop-receiving vehicle. Removably mounted over the discharge opening is a recutter screen that has an arcuate shape generally concentric with and adjacent to the cutterhead periphery and a plurality of elongated apertures, each aperture having parallel longitudinal edges that extend diagonally relative to the knife cutting edges. The apertures are arranged in two transversely extending rows with the apertures in one row being inclined in one direction from the vertical and the apertures in the adjacent row being inclined in the opposite direction, the opposite angle of inclination of the apertures in the second row counteracting the tendency of the apertures in the first row to move the crop material impelled through the apertures in the direction of inclination. Alternate screens are conventionally provided with different size apertures according to the fineness of cut desired, and the screens are removably mounted in a frame that is adjustable relative to the cutterhead to maintain the optimum minimum clearance between the cutterhead and the recutter screen.