RF.L.ns i.\ iiiE niii.i. sysri;.\r 17 



llio ri'liiNS (lillVring onK in \\iii<lin);s and in tin- nninln-i- of CDnt.icl- 

 e\irryini; springs with which lhe\' were e(|iiip[H-(l. Tlic (lf\elopnicnt 

 of these relays resulted in a price reduction for llie line and cutoff 

 relay luiit of about 2o per cent, and a reduction in ilic nmunting 

 space occupieil of 40 per cent. The Hat core and (lie manner of 

 suspending tlie armature on a reed hinge, in order to present the 

 armature to the pole face, were the distinctive features of the new 



••7-J7 Type MOUNT1N&, plate. 



Fig. 11 — M^ninting jilatc fur strip of punched frame relays 



rela>' structure, as will be seen b\- referring to Fig. 10, in which the 

 line and cutoff relays may be distinguished because they are equipped 

 with a single pair and a double pair of contacts, respectively. The 

 method of mounting the relays and protecting a strip of 20 with a 

 comnu)n dust cover is shown in Fig. 11 from which it will be observed 

 that the mounting plate, all the mounting details and the cover, are 

 products f)f the punch jjress. 



When it was seen that the dc\eIopment of the new line and cutotT 

 relays was proceeding fa\'orably, development work was also bcgim 

 on a similar punched-type substitute for the round core supervisory 

 relay which has previousK- been described. It was known that the 

 quantity of iron in the supervisor>' relay was greatly in excess of 

 the amount required, as the core flux density was far below satura- 

 tion when the relay operated over the longer substation loops and 



