Axial flow combine having concave relief

In an axial flow combine provided with

• a. a casing having an infeed end arranged to receive crop material in a substantially axial direction,
• b. a rotor extending generally axially in said casing rearwardly from the infeed end thereof,
• c. rasp bar means extending along said rotor at spaced locations thereon,
• d. and a concave supported within said casing at least partially along the lower surface portion of said rotor for cooperation with said rasp bar means on said rotor to form a threshing region in which crop material is threshed therebetween in a substantially radial movement and said concave having an inlet end adjacent the infeed end of said casing;
• the improvement comprising in combination therewith:
• e. a relief section in said inlet end of said concave and extending longitudinally thereof a predetermined distance inwardly from said inlet end and underlying the forward portions of said rasp bar means, thereby providing a thinning space adjacent the inlet end of said threshing region into which abnormally large masses of material may be accommodated in a generally axial direction and converted to radial movement prior to passing farther into said threshing region for primarily radial movement therein and thereby minimize power requirements and wear upon the threshing components of the combine resulting also in minimizing customary thumping of the masses of material which normally occurs under similar conventional combine circumstances.