CARD TRANSLATOR FOR NATIONWIDE DIALING 



1085 



LATCH CONTACT SPRINGS 



Fig. 32 — Jack side of dynamic unit showing latch contact springs. 



rooming due to impact would be experienced. It is possible to maintain a 

 small operated gap because the down-stop position of the solenoid 

 operated bars is precisely controlled by common stop details that engage 

 the solenoid operated bars and thus limit the motion of the solenoid 

 plungers to which they are coupled. The solenoid is provided as a package 

 including the necessary retractile spring and coupling details. One of the 

 coupUng details is a rubber buffer. This buffer cushions the impact 

 developed when the bar that is coupled to the solenoid engages the up- 

 stop. At the top of the bar coupling detail another rubber buffer is 

 mounted. This second buffer cushions the impact when the downstop is 

 engaged. A crowned washer is cemented to the first buffer and the 

 assembly provides a slight vertical freedom of the plunger extension in 

 the bar coupling detail. Combined, these features permit sufficient free- 

 dom of action to prevent binding in the event one solenoid of a bar acts 

 faster than the other. 



The average operate and restoral times of the solenoid are 32 and 28 

 milliseconds, respectively. The unoperate gap pull averages 325 grams, 

 and the unoperated force of the retractile spring is 200 grams. The 

 solenoids are operated dry to prevent gumming. 



The beryllium copper coupling details secured to the ends of the 

 solenoid operated bars provide a slot through which the flattened ex- 

 tension of the solenoid plunger passes. The position control of the 

 solenoids and of the bars is such that side friction at the coupling is 

 virtually non-existent. There is adequate end or longitudinal clearance 

 to permit of unrestrained tilting of the bars such as may be experienced 

 if one solenoid operates faster than the other. 



