January i, 1903.] 



THE INDIA RUBBER WORLD 



117 



VARIABLE SPEED DEVICES FOR RUBBER MILLS.— II. 



By J. O. De Wolf. 



IN continuation of the article on this subject in the Decem- 

 ber issue of The India Rubber World, a brief descrip- 

 tion will be given of two other means of accomplishing 

 the results described in that article. 

 In Figures i and 2, presented herewith, are shown two views 

 of the " Reeves Variable Speed Transmission " made by the 



FIQ. 1.— REEVES VARIABLE SPEED ; RANSMIBSHN. 



Reeves Pulley Co. (^Columbus, Indiana). The conspicuous 

 feature of this device is two sets of cone disks mounted on 

 parallel shafts and so keyed that they revolve with the shafts 

 and yet can be moved longitudinally along the shafts. These 

 disks are attached to pivoted bars which are operated by a 

 screw so that one pair of disks is moved together as the other 

 set is moved apart. The combination of bars and pivots is 

 such as to preserve a substantially uniform tension in the belt, 

 which is of the utmost importance in the operation of the de- 

 vice. 



By reference to the cuts it will be seen that the inner sides of 

 the disks form a V-groove in which runs a specially constructed 

 belt that has its bearing surfaces on the edges and drives by the 

 contact of the edges with the cones. In operation one set o 

 disks is the driver and the other the driven, the relative speeds 

 being varied by increasing or decreasing the driving circum- 

 ference of the disks by moving them apart or closing them to- 

 gether as occasion requires. 



Figure i shows the belt in the same position on both disks 

 so that the speeds of driving and driven shafts are the 

 same. In Figure 2 the pivoted bars DD are in such 

 position that the belt drives from the smallest circum- 

 ference of the driving disks CC and runs on the driven 

 disks at their largest circumference, thus reducing the 

 speed of the driven shaft B to the minimum. Figure 2 

 shows a heavier form of transmission than shown in 

 Figure I, and also illustrates the power shifting device 

 EE which is applied to the larger sizes, for turning 

 the screws that controls the cones; on the smaller sizes 

 this is done by hand. 



This variable speed transmission is manufactured in 

 diflferent sizes which the manufacturers rate from 2^ 



H. P. to 150 H. P., and which give a variation in speed of from 

 10 to I on some of the smaller transmissions, to 2 to i on the 

 heavier ones. 



The several forms of speed changing devices that have thus 

 far been referred to all depend on some well known mechanical 

 principle for accomplishing their purpose. With the increased 



FIQ. 2 —REEVES VARIABLE SPEED TRANSMISSION. 



use of electricity means have been found for obtaining any de- 

 sired variation in speed through the use of an electric motor. 

 Such an arrangement for driving a calendar is shown in Figure 



FIQ. 3.— CALENDER DRIVEN BY ELECTRIC MOTOR. 



