Dual action corn cob separation and improved chaffer for whole corn cobs

An axial flow rotary combine cleaning system comprising a chaffer sieve having a front and a rear portion, said front portion constituting 25 to 40% of the surface area of said chaffer and receiving substantially corn kernels from the front portion of a combine threshing zone;

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• said sieve having a rear portion constituting 75 to 60% of the surface area of the chaffer and receiving and cleaning substantially whole corn cobs having lengths of predominantly at least 3 inches;
• said front portion of said sieve comprising louvered vanes with extended fingers having about 1.125 to about 1.625 inches spacing between said extended fingers;
• said rear portion of the sieve comprising louvered vanes with elongated fingers about twice the length of the front portion's extended fingers, and said elongated fingers being greater than 3 inches in length and having 2 to 4 inches spacing taken in the transverse to fore and aft direction of the crop material flow between said elongated finger and 3 to 4 inches spacing between the louvers;
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• said rear portion's elongated fingers having humped or rounded profile which effectively turns the widthwise flow of corn cobs over the surface of the chaffer so as to reorient the whole cobs having lengths longer than the width between the fingers, to a lengthwise orientation for accommodating their passing through the openings between the elongated fingers.