50 LEATHER BELTING 



J, Jackshaft belts. That is, all belts from line shaft to 



the jackshaft. Subdivided into 

 JO, Jackshaft belts, open. 

 JC, Jackshaft belts, crossed. 

 All jackshafts should be numbered and the number of the 



jackshaft prefixed to the belt symbol. 

 L, Main line shaft belts. That is, all belts from engine 



jackshaft to the line shaft. Subdivided into 

 LO, Main line shaft belts, open. 

 LC, Main line shaft belts, crossed. 

 M, Machine belts. That is, all belts from countershafts 



to the machines and used for operating them. 

 Subdivided into 

 MO, Machine belts, open. 

 MC, Machine belts, crossed. 

 S, All belts from main line shaft to side line shaft. 

 SO, Side line shaft belts, open. 

 SC, Side line shaft belts, crossed. 



The various shafts should be numbered and a list of these 

 numbers posted where it is accessible to the belt-fixer, show- 

 ing the location of all shafts and machines. 



Maintaining the Tension in Belts. New belts usually 

 stretch to such an extent that they require tightening within 

 twenty-four hours after being put up. The second tighten- 

 ing, as a rule, should take place forty-eight hours later; the 

 third tightening at the end of a week, and another at the end 

 of a month. Machine or cone belts should then be taken 

 down and have their tension measured every two months, 

 while for countershaft belts three to four months may elapse. 

 The time at which any given belt should be tightened is 

 determined by the entries made on the belting record, shown 

 in Fig. ii. 



For instance: Referring to the chart illustrated it will 

 be noted that the belt was to be put on the pulleys under a 

 tension of 130 Ib. on each spring balance, or a total of 260 Ib. 



