1074 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1953 



and code select bar deflection. Twelve compartments fully loaded can 

 accommodate nearly 1200 cards. Thus a comfortable margin beyond 

 the 1000-card capacity requirement has been provided. 



Card thickness was controlled by considerations such as stiffness 

 of the tabs, flatness and overall length of the card stack. It ultimately 

 was concluded that the optimum thickness is 0.007'' nominal. 



The weight of a card after coding averages 40 grams and, considering 

 that nearly 1200 cards may be in translator the total card load is ap- 

 proximately 100 pounds. This is considered to be enormous from a 

 telephone switching apparatus viewpoint and largely accounts for the 

 need of the pull-up magnet. 



Manipulation in effecting a translation has to be fast. The displace- 

 ment of the selected card has to be comparatively large and the card 

 stack, which also has to be moved for each translation but to a lesser 

 extent, is exceptionally heavy. These are not compatible conditions 

 but by advantageous coordination of the pull-up magnet, the pull-down 

 magnet, the latches and the card support bar lift magnets, it has been 

 possible to meet them reliably. 



FILLED BIN 



PARTIALLY FILLED 

 BIN (NOTE LEAN) 



PARTIALLY FILLED BIN 

 (NOTE THAT CARDS 



NOW STAND UPRIGHT 

 AND ARE FANNED) 



SINGLE CARD 

 (NOTE THAT CARD 

 NOW STANDS UPRIGHT) 



BEFORE MAGNETIZATION AFTER MAGNETIZATION 



Fig. 26 — Card stack before and after magnetization. 



