Abstract: The crop discharge spout of an agricultural machine is continuously adjusted so that the crop material discharge therefrom is always directed into an associated, but not necessarily connected, collector vehicle. An electro optical device affixed to the crop discharge spout illuminates a scanning area with an optical signal. A passive retroreflective target affixed to the collector vehicle and disposed within the scanning area reflects the optical signal back to the electro optical device. The electro optical device receives the reflected optical signal and causes logic means to generate control signals, such that appropriate utilization means aligns the crop discharge spout with the associated but not necessarily attached collector vehicle.

Abstract: Magnetic-electronic apparatus for sensing the clearance between two ferrous metals, for application in measuring the clearance between a shear bar and the cutting knives of a harvesting farm machine, is disclosed having a magnetic sensor disposed within the shear bar for producing a magnetic field, the interception of which by the passage of a knife produces an electronic signal which is processed by appropriate circuitry for indicating the clearance between the knives and the shear bar.