82 Description of a new Thrashing Machine. 



The axis of the second roller is hung at each end upon a 

 pivot, so that when the feed is too great the roller will 

 open, and be brought back again by a weight suspended at 

 the end of a small lever. 



The drum is made open, and the beaters fixed upon a. 

 Tino at each end. 



My machine is greatly improved by giving the drum (as 

 well as the large wheel) a flv motion. The rines are made 

 thin and light of wood, and the beaters of bar iron. The 

 more simple way perhaps would be to make the rings of 

 cast iron, and throw the weight to the rim. 



The leading feature of Mr. Wilson's machine is the 

 situation of the parallel ribbed plates against which the 

 corn is beaten or rubbed. Compared with other machines, 

 they may be said to be divided : one part is fixed upon the 

 levers which carry the feed rollers, the distance of which is 

 regulated by a screw through the lop of the frame ; — the 

 other i* fixed in the frame which carries the iron grating, 

 and with that the distance is regulated by a screw at each 

 corner. 



It will be seen that the straw after passing the first plate 

 may take a diffeient direction before it enters upon the se- 

 cond plate and grating, and to this circumstance I think is 

 to be attributed the machine's superior work. By placing 

 the feed rollers so far from the ribbed plate, and beaters, 

 the straw is not at all broken, but will admit of being tied 

 up in boltings, as well as if thrashed by the flail. 



The great wheel of this machine is six feet six inches 

 diameter — to avoid resistance from the air, it is but two 

 inches in thickness, and the spokfs are made elliptical. To 

 give it a fly motion, fifty-six pounds of cast iron are added 

 to the ends of the spokes, as described in the elevation. 

 Thi'< weight is suflScient to lead the men on, so that the 

 difficulty is not to keep them up to a certain number of 

 revolutions per minute, but to dissuade them from doing 

 too much. 



The pulley hitherto worked upon the drum has been 

 either oue-tighth or one tenth the diameter of the wheel ; 

 and as in working the former is lighter, I find the velocity 

 of the hand increased in proportion The niinin)um ve- 

 locity of the hand is forty revokilions per minute, and this 

 carries the drum tiirough a greater space than that of any 

 ordinary machine of two or lour horse power. 



The winches at first were made to describe a cir:;le of 

 thirty-six, but wert subsequently shortened to one of thirty 

 inches diameter. 



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