Patent ID: 9717183
Date: 2017-08-01
CPC Classifications: A01F

Claim:
1. A combine harvester comprising threshing apparatus, grain separating apparatus, a return conveyor, a grain pan and a cleaning unit, the grain pan arranged to catch a grain/chaff stream falling from the threshing apparatus and being driven in an oscillating manner to convey the collected grain/chaff stream rearwardly to a rear edge from where the grain/chaff stream falls into the cleaning unit, the return conveyor located underneath the separating apparatus and serving to convey a secondary grain/chaff stream forward to a front edge from where the secondary grain/chaff stream falls onto the grain pan, the cleaning unit comprising a fan unit for generating a first cleaning airstream which is directed under the grain pan and through the grain/chaff stream falling from said rear edge, the combine harvester further comprising means to generate a second cleaning airstream which is vented above the grain pan through one or more vents secured to the underside of the return conveyor.