BELT SHIFTERS 



87' 



of the belt on either the tight or loose pulley, the shifter pole 

 hangs vertically and bears against one or the other of the 

 pins. Thus, in the illustration the pole resting against the 

 pin B is in position to move the belt on to the pulley L. In 

 doing this the pin B will move to B'; the pin C will take the 

 position C', and the shifter pole will rest against it as soon as 

 the pole is released after moving the belt on to the pulley L, 

 thereby being in position to move the belt back to pulley T. 



FIG. 31. ROLLERS FOR SHIFTING HEAVY BELTS. 



The belt fork has no tendency to move from the position in 

 which it is left by the pole, and if the pulleys are crowned, 

 the belt also will remain in the position where it is left. 



For shifting wide and heavy belts a pair of rollers making 

 an angle of about 75 degrees with the center line of the belt are 

 advisable. These rollers may be arranged so that they can 

 be pressed against the belt, whereupon the belt will be 

 forced over on to the other pulley. This arrangement is 

 shown in Fig. 31. 



