/>/s7(;.v ( ii.iR.ici i:iasms or /•/./;( //v-o.u./t/.v /r/.v 



225 



riHluri" woiiUI ii»\t)lve endless etiuipmeiit chanjjcs as well as the larRC 

 •iiul iinnecessiiry manufacturing expense of making an excessive 

 numher of t>|H"s of relays. Much of the relay engineering work of 

 the past few years has therefore been directed toward the standard- 

 i/alion of rela\- desii;ns which would he tlexihle. reriahle and economical 



'=!C-12 



-X-A[)jL>jTi\jONUT 



as a whole in the telephone plant rather than the most cfticieiU in all 

 respects for any specific condition. The flat or punched type relay 

 manufactured by the Western Electric Compan\- represents largely 

 the result of this effort. 



The flat relay is essentially a punch press product manufactured 

 \early in large quantities and in about 3,000 varieties of windings 

 and switching or contacting arrangements. The punch press method 

 produces parts which are exact duplicates and therefore interchange- 

 able which is particularly advantageous both for assembly and re- 

 placements or repairs. All the springs as well as the core and arma- 

 ture are punched and formed in bending fixtures to the required 

 ■shapes. The mounting plates are also punched and designed to 

 permit of uniform and economical mounting of the relays. 



A number of these relays are shown on a punched mounting plate 

 in Fig. 12. Referring to the figure it will be seen that the relays are 

 insulated from the mounting plate by phenol fibre insulators "A," 



