Abstract: A twin stick control system for a movable unit such as a ZRT vehicle includes two control sticks placed side-by-side. Each control stick controls the operation of at least one drive wheel on each side of the vehicle. The control sticks are movable from their neutral position in a first range of motion without any interference from a spring restoring force tending to return them to neutral, thus allowing the control sticks to remain wherever the operator places them in the first range of motion. A cruise control system is located to abut against the control sticks at the conclusion of the first range of motion to define a cruise control speed setting. The sticks can still be advanced forwardly beyond the cruise control speed setting, but encounter a spring force when doing so which is directed to returning the sticks back to the cruise control speed setting.

Abstract: A combined concave and rock door structure is provided for an agricultural harvester wherein the rock door and the arms supporting the concave are pivotally mounted on the same transverse axis by a pair of pivot support structures. A control mechanism is provided for adjusting the threshing clearance of the concave and the concave is adjustable to maintain concentricity with the threshing rotor.

Abstract: Removable flow retarding finger attachment is mounted on the outside of the perforated cylinder cage of an axial flow harvester with fingers extending through the openings in the cage to slow the axial flow of crop material through the spirally ridged cage. Two embodiments of the invention are illustrated. In one version, the finger attachment is removably secured to the cage in a flow retarding position by releasable fastening means. In the other version, power means is provided to permit selective adjustment of the fingers between flow retarding and retracted positions.

Abstract: An improved drive mechanism and support arrangement for an agitator device used for preventing an accumulation of straw or the like on the upper outer peripheral surface of a screen-like cylindrical cylinder cage surrounding an axial flow threshing cylinder which rotates within the screen-like cage. The agitator device comprises a "main beam" which extends axially of and in overlying relation to the upper outer peripheral surface of the cylinder cage. A plurality of arcuate scraper fingers are mounted on and move with the "main beam" and extend in contiguous overlying relation to the outer periphery of the cylinder cage. A carriage member secured to the agitator device is mounted for sliding movement on a pair of horizontal guide rails. Reciprocating movement is imparted to the slidable carriage and to the agitator device by an endless drive chain which is driven at a constant speed and with a continuous motion.