STRUCTURE OF SCREENING PART OF THRESHER

PROBLEM TO BE SOLVED: To provide a structure of screening part in a thresher making possible to introduce a part of supplementary grading wind from a winnower into a shaker screen case in such a manner that wind power loss is suppressed and at the same time the disturbance of treatd materials on the shaker screen case is suppressed. SOLUTION: This structure of grading part is constructed so that supplementary grading air from a winnower 6 is introduced into a swinging grading case 5 through a supplementary grading wind introducing port 22 formed in a front wall 21 extending from a front grain pan 12 of the swinging grading case 5 to a fine grading part 14 below the pan 12, and further a wind blocking body S for preventing the forward blowing out of the supplementary grading wind is placed so that it covers the lateral width of the grading case 5 at a forward place of the front wall 21 of the grading case 5.