Apparatus for clearing the screen of crop-harvesting product

Claim 1

In a leguminous plant harvester of the type comprising a rotating drum screen for receiving the vines and attached crop at one end of the drum and discharging vines and trash at the other end, beaters in the drum and means for cleaning the screen; the improvement wherein said screen cleaning means comprises an external, closed end air pipe running parallel to the screen axis at an upper portion of the drum screen, means mounting said pipe for axial reciprocation along said drum screen, a plurality of spaced air nozzles depending directly from said air pipe, said nozzles being directed toward said drum screen along its length, those nozzles disposed at the material discharge end of the drum screen having larger apertures than those at the material receiving end of the drum screen, means for reciprocating said air pipe axially of the screen by a distance of at least one half of and not substantially greater than the spacing between adjacent nozzles, and a flexible hose connected to the other end of the pipe for supplying compressed air thereto.