Crop harvester having height control

Claim 1

A grain harvester comprising a wheeled frame adapted to be advanced in a field in a predetermined direction; a header mounted to said wheeled frame; a first drum mounted on said header for rotation about a horizontal axis transverse to said direction of travel; said drum including means for stripping the grain including the heads from the stalks; means for rotating said first drum as said harvester advances; means for varying the rotational speed of said first drum; a second drum rotatably mounted on said frame for rotation about the horizontal axis transverse to the direction of travel; means for rotating said second drum; shield means surrounding a portion of said first drum to generate air flow between the inner surface of said shield means and said first drum when said first drum is rotated; at least one sensor means for sensing a first point at the top of the grain to measure the distance said first drum is above the crop stalks to be harvested; a second sensor means for sensing the distance from said first sensor means to a second point on said crop stalks; means for adjusting said harvesting means to maintain predetermined differential between the distances measured by the first and second sensors; a separation chamber receiving on one side the air flow generated by the rotation of the first drum means and the loose grain removed from said stalk by the action of said first and second drum means; means for generating a suction on a second side of said separation chamber; means for creating said suction comprising a fan means having its input side connected to said chamber means; a third rotating drum surrounding said fan means; means for adjusting the amount of each of said air flows on said third drum; discharge means for discharging the material other than grain after removal from the third rotating drum by the pressure of the fan; collection means for collecting and holding the grain after separation; means for moving the grain collected in said collection means to the center of said means; means at the center of the chamber and said collection means for expelling the grain from the collection area; a second means for separating the grain from the heads connected to said collection means, said second separating means including a plurality of rotating brushes; means for independently driving the brushes at variable speeds resulting variable differential peripheral velocities; means for carrying the grain from said second separation means to a receptacle.