GB1207804A - Improvements in or relating to separating assemblies - Google Patents

Abstract

1,207,804. Combine harvesters. NATIONAL RESEARCH DEVELOPMENT CORP. 4 Dec., 1967 [15 Dec., 1966], No. 56233/66. Heading A1F. A combine harvester has a threshing mechanism 26 consisting of a cylinder 28 and a concave 30; and the path of the different constituents of the crop propelled from the concave is modified by an air curtain from a fan 46 to produce partial separation of grain. The leading half 37 of the concave is provided with thresher bar 36 and the trailing half 38 is smooth; and the gap between the cylinder and the concave decreases towards the trailing edge of the concave. Clean grain passes through the part 56A of the run 56 of a perforated, three-run separating conveyer 48 to the trough 64 and is then taken to a grain tank 72 by an auger 68; and the partially clean grain passes through the lower part 56B to the trough 62, while the straw, chaff and grain falls on straw walkers 74 from where the grain with some chaff falls into collector 78; and straw and chaff is discharged at 75. The grain with chaff at the troughs 62 and 78 is fed at 84 to a smooth, non-threshing portion (88) (Fig. 1, not shown) of thresher 26 and re-subjected to the air curtain. In Fig. 5, an additional suction fan 250 is disposed to increase efficiency. In another embodiment, (Fig. 3, not shown) the three-run conveyer is replaced by a two-run conveyer 100. In another embodiment, the concave is above the cylinder and the fan disposed below. In yet another arrangement, the straw-walkers can be replaced by an endless sifter conveyer (302) (Fig. 7, not shown).