Patent ID: 7472532
Filing Date: 2009-01-06
Classification: A01D

Abstract:
1. An agricultural harvesting machine comprising: means for processing harvested crop material; feeder means for feeding harvested crop material to said processing means along a crop feed path; wherein said feeder means includes at least one feeder roll having a substantially cylindrical wall made out of non-ferromagnetic material; foreign object detector means for signaling the presence of foreign objects in said harvested crop, said detector means comprising a sensor having a detection field transverse to said crop feed path and extending into at least a portion of said path, wherein said sensor includes at least one magnet, wherein said detection field is a magnetic field, wherein said sensor is substantially symmetric with respect to a direction transverse to said crop feed path; said detector means further includes restriction means distinct from said sensor, making said detection field asymmetric with respect to said transverse direction, wherein said restriction means comprise a ferromagnetic plate extending rearwardly from said sensor, and further wherein said sensor and said ferromagnetic plate are installed within said wall.