CHAPTER III 

 THE HORSEPOWER TRANSMITTED BY LEATHER BELTING 



General Formula for Horsepower of Belting. The general 

 formula for the horsepower transmitted by a leather belt 

 of i sq. in. cross-sectional area is 



33000 



in which p is the effective pull in the belt in pounds, and V 

 is the velocity of the belt in feet per minute. If we let ti 

 and fa represent respectively the tensions in the tight and 

 slack strands of a running belt, 



p=ti-h. ...... (2) 



The determination of the value of p is by no means the 

 simple proposition that it appears from the formula, nor is 

 it necessary for those who have no particular liking for 

 mathematical problems, and who are interested only in the 

 amount of horsepower that a belt will transmit under a given 

 set of conditions, such as are usual in the shop, or who desire 

 to ascertain the size of belt that should be used to transmit 

 a given amount of power to a machine or group of machines. 

 For this purpose the tables on pages 91 to no are available, 

 and will prove of greater practical value than the mathematics 

 by which they were calculated. The use of the tables will, 

 therefore, be explained, and the mathematics of them post- 

 poned to another chapter. They can be ignored by those not 

 interested. The tables are calculated from the formulae 

 developed by Carl G. Earth and represent the practice 

 recommended by him in his paper " The Transmission of 

 Power by Leather Belting." 1 



1 Transactions, American Society of Mechanical Engineers, vol. xxxi, p. 29. 



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