Stepped grate for an agricultural combine

Abstract

A grate for an agricultural combine includes curved grate segments, each of which include mounting holes in at least one end segment. To provide a threshing grate, the end segments of the grate segments are offset to provide a “step”, or discontinuity in the radius of the assembled grate, which improves the threshing efficiency of the combine. The step can be provided by offsetting mounting holes between adjacent grate segments, and securing the grates to a frame member.

1 - 14 . (canceled)  
   
   
       15 . An apparatus for threshing grain comprising: 
 a rotor provided in a rotor housing;    a threshing grate located between the rotor and the housing, the threshing grate comprising at least a first and a second curved grate member each grate member comprising first and second curved side members extending between first and second rectangular end members, at least one of the end segments of the first grate member abutting at least one of the end segments of the second grate member to form a grate having a radius extending substantially around the rotor, the end segment of each of the first and second grate members including a mounting tab extending away from the grate member, the first grate member being offset from the second grate member at the abutment surface to provide a step in the radius of the grate at which one of the first and second grate members is radially closer to the rotor than the other of the first and second grate members and;    a frame member having first and second end segments, first and second parallel curved sides extending between the first and second end segments, and at least one longitudinally-extending mounting bar extending between the first and second parallel curved sides at a location between the first and second end segments, the area between each of the first and second end segments and the longitudinally-extending mounting bar being sized and dimensioned to receive one of the first and second grate members, wherein the longitudinally-extending mounting bar includes includes downwardly extending tabs including aperatures for coupling the first grate member and the second grate member to the frame.    
   
   
       16 . The apparatus as defined in  claim 15  wherein the mounting tabs at the first and second grate members each comprise a plurality of apertures.  
   
   
       17 . (canceled)  
   
   
       18 . The apparatus as defined in  claim 15 , wherein mounting tabs at the end segments of each of the first and second grate members includes an aperture for mounting the grate member to the longitudinally extending mounting bracket.