CONTACT WELDING IN WIRE SPRING RELAYS 



919 



tiple leaf brush under considerable pressure connects the one side of the 

 circuit to the terminal end of the individual wire beiiifi; welded. Tiie ^un, 

 and through it the contact block, is connected to the other side of the 

 circuit. After a cam frees the gun, the spring propells it toward the wire 

 end and an electrical arc is established by the high potential (900 to 



SILICON-COPPER 

 WIRE 



»*»-ili^*!8SaC 



CUPRO- NICKEL 

 CONTACT . 



Fig. 19 — Section of a percussion weld. Original amplification 100 X. 



20 40 60 80 100 120 140 160 180 200 220 240 



ARC DURATION IN MICROSECONDS 



P'ig. 20 — Weld strength versus arc duration. 



