196 



CHAPTER XI 



The pinion on the end of this shaft co-acts and gears with the pinions 

 on the shafts of the lower rollers. The lower rollers then will rotate in the 

 same sense, and in a sense opposite to that in which the upper roller rotates ; 

 the direction of rotation, clockwise or counter-clockwise, depending on the 



Fig. 84 



direction in which the material being crushed travels. The upper roller, a, 

 is known as the top roller ; that lower roller, ^a. which first receives the 

 material is known as the front, feed or cane roller ; the other roller, a^, 

 is known as the back, discharge or bagasse roller. 



Reference to Fig. 81 shows that there is formed a space between the 

 lower rollers where it is necessary to define a passage for the material until 

 it is gripped by the top and back rollers. This passage is defined by the lower 





Fig. 86 



Fig. 85 



Fig. 87 



portion of the top roller and by a bar of varied shape and curvature sup- 

 ported on the housings and running parallel to the axes of the rollers. This 

 bar is known as the trash turner, returner bar, dumb returner, knife, bagasse 

 bridge or bagasse guide, and, to avoid confusion, is not shown in Fig. 81. 

 The exact arrangements employed by different firms show considerable 



