MANUFACTURING LEAD-COVERED TELEPHONE CABLE 335 



Each spool, containing two conductors, is mounted in a yoke which 

 revolves on its own axis to give the pair twist and the two yokes are 

 revolved around each other to give the quad twist. This is ac- 

 complished by an arrangement of change gears from which can be ob- 

 tained practically any length or direction of twist desired. 



30 

 LONG STROKE 



LEAD PER 

 CHARGE 



I 



1100 LBS. 



30 

 SHORT STROKE 



700 LBS. 



220 LBS. 



MAX. AMOUNT I 

 OF LEAD I 



PER HOUR I 



4543 LBS. 3650 LBS. 1700 LBS. 



Fig. 12 — Schematic showing relative increase in size of lead presses 



Modern stranders follow the same general line as the older stranders 

 but the whole design has been reviewed in detail with the view of 

 strengthening and perfecting, and improved tension devices have been 

 developed consisting of a tension arm actuated by the pair which in 

 turn applies a brake to or removes it from the reel head. These are 

 adjusted to give a tension of about three pounds per pair which causes 

 no stretch and prevents over-running. With these, it is possible to 

 run very fine wires at a minimum tension with a maximum smoothness 

 of operation. The drums are gear driven and are capable of running 

 up to 100 R.P.M. 



After stranding, the cores are dried under vacuum to remove the 

 moisture from the paper and then are covered with a lead alloy sheath. 



It is necessary after the cable is removed from the vacuum drier to 

 keep it in an atmosphere of a low moisture content until the lead sheath 

 is applied. This was formerly accomplished by placing it in an oven 



