Tramp-iron remover for forage harvester

NAILS, WIRE, AND OTHER TRAMP IRON in hay are likely to puncture the stomach of a cow if ingested. Pneumatic conveyors are often the only devices handling hay and conveying speeds of 8,000 feet per minute are common. A metal detector offers no obstruction to flow. Combined with a mechanical rejecting device it offers a means of tramp-iron removal at even the highest pneumatic conveyor speeds. A suitable combination has been described by J. B. Dobie, et al, in an article “Electronic Detection and Removal of Tramp Iron from Chopped Hay,” which appeared in Agricultural Engineering, June, 1953, and by J. B. Dobie and F. C. Jacob in another article “Removing Tramp Iron from Chopped Hay,” which appeared in Electronics, June 1954. This combination is for use with fixed installations such as barns or feedmills. The same method can be adapted to a field forage harvester to make a self-contained unit. However, the blower pipe is shorter, the hay delivery rate is more variable, the hay has variable moisture, the vibration environment is more severe, and the problem of disposal is more awkward for the field harvester as compared to a stationary machine. Appropriate design can accommodate these factors.