Improvement of MacTavish Thresher

It was time-consuming and troublesome to reposition the threshing teeth and frame bars in a Mactavish thresher once their working surfaces became blunt,and it was aslo hard to clean these surfaces.Therefore,the head box was improved as following:1) change the vertical door into an arc door symmetrical to the other side,and let the threshing drum be workable in either way;2) mount a two-position guide plate above the thresher to avoid tobacco jam;3) add an interlock system to ensure that the rotating direction of threshing drum was coincident with the position of guide plate.The improved thresher featured reversible threshing,automatic cleaning of drum teeth and frame bars,and reduction of maintenance work and labor intensity.The working efficiency of thresher increased from 85% to 90%,and the strip yield improved by about 0.2%-0.3%.