Abstract: A grain harvesting combine is provided with an improved sieve plate for more efficient cleaning of the grain. The sieve plate is mounted on the combine adjacent the rearward end thereof and is substantially rectangular in shape. The sieve plate has forward and rearward edges and opposite side edges, the forward edge and side edges being substantially coplanar. The sieve plate also has a forward portion which slopes downwardly from the forward edge and terminates in a substantially flat portion extending rearwardly to the rearward edge. Inclined opposite side portions are also provided which slope downwardly from each side edge to the flat portion of the sieve. The degree of incline of the forward portion and side portions is approximately 5.degree. from the flat portion. The inclined side portions minimized grain loss when the combine is operating on sloping terrain.

Abstract: An improved concave for use on a combine has a plurality of spaced-apart bars mounted parallel to the axis of rotation of the combine cylinder and at an angle with respect to a radial line passing from the center of the cylinder through each of the bars. The angle of inclination of the bars increases progressively from the intake end to the discharge end of the concave. The passageway between the concave and the cylinder also becomes progressively smaller from the intake to the discharge end of the concave. The angle of inclination of the bars aids the passage of grain between the bars and reduces resistence of the bars to the passage of grain therebetween.

Abstract: A conventional grain harvesting combine is disclosed herein comprising a wheel supported body, a grain harvesting means on the forward end thereof, at least two parallel substantially horizontal spaced perforated sieve plates adjacent the rearward end thereof, and a fan means adapted to direct air upwardly and rearwardly through the sieve plates to remove chaff from harvested grain thereon. The improvement to this conventional structure as disclosed herein comprises an end gate on the combine which acts in conjunction with at least two baffle members which extend laterally across the body member adjacent the rearward ends of the sieve plates to substantially reduce the amount of air flowing upwardly and rearwardly through the rearward end of the uppermost sieve plate. The baffle members can be either of solid or perforated construction or a combination thereof.