22 



LEATHER BELTING 



The tables show the horsepower that will be transmitted 

 under any given set of conditions, and also the tensions under 

 which the belts should be put up, and the minimum tensions 

 to which they may be allowed to fall in service before they 

 should be retightened to the original tension. If the belts 



[LVM -->., 



x x ~~ : 



100 150 140 



Arc of Contact. Degrees 



FIG. 2. RELATION BETWEEN ARC OF CONTACT AND HORSEPOWER TRANS- 

 MITTED BY MACHINE AND COUNTERSHAFT BELTS. 



are put up under the tensions given in the tables, while they 

 are at rest, they will when running develop in the tight and 

 loose strands such values of t\ and fa as will give the value of 

 p, which will at the velocity that the belt is supposed to attain 

 develop the required horsepower. 



Effect of Arc of Contact. The arc of contact of the belt 

 on the pulley has a direct bearing on the horsepower that can 



