Patent ID: 7846013
Filing Date: 2010-12-07
Classification: A01D,A01F

Abstract:
1. A controlled crop cleaning mechanism for a harvester such as a combine, said mechanism comprising: a sieve, said sieve having a plurality of openings, each of said openings being adjustable between a narrower position and a wider position; a fan, said fan being disposed to blow air through said openings of said sieve sufficient to separate crop from chaff, said fan being adjustable between a faster and a slower speed; a sensor, said sensor sensing a load on said sieve, said sensing being independent of said air blown by said fan; a controller, said controller being in operative communication with said sensor to receive a signal corresponding to a load sensed and said controller being in operative communication with an adjustor of said openings, said controller being configured to widen said openings when said sensed load increases and to narrow said openings when said sensed load decreases, said controller being further configured such that said widening and said narrowing is directly responsive to said sensed load and exclusive of any effect of said air blown by said fan; wherein said controller is preconfigured to change said position of said openings according to a first function of said sensed load when said fan is at a first speed and to change said position of said openings according to a second function when said fan is at a second speed.