THRESHER

PROBLEM TO BE SOLVED: To provide a thresher improving the processing performance of threshed objects in a secondary threshing drum and discharging dust-disposal drum. SOLUTION: This thresher is provided by obtaining primary objects by threshing the reaped cereal culms while nipping them in a threshing drum 41 in a threshing chamber 40, processing secondary objects not threshed in the threshing drum 41, in a secondary processing chamber 58 pivoting a secondary-processing drum 60 having a helical body 60a arranged adjacent to the threshing chamber 40, and disposing of the threshing chamber dust objects in a discharging dust-disposal chamber 63 pivoting a discharging dust-disposal drum 64 having a helical body 64a at the rear stage of the secondary processing chamber 58. By arranging the helical bodies 60a, 64a in succession in the conveying direction of the processed objects, and since both of them are continuous helical bodies, conveying efficiency is improved as compared with that of intermittently installed planted teeth. By setting the diameter of a first helical body 64a of the discharging dust-disposal drum 64 facing to a communicating port 40a from the threshing chamber 40 to the discharging dust-disposal chamber 63 as larger than that of a second body 64a on the rear side than the first one, the taking-in capacity of the processed objects from the threshing chamber 40 side to the discharged dust-disposal chamber 63 side is improved. COPYRIGHT: (C)2008,JPO&INPIT